Updated on 2022/05/26

写真a

 
HASEBE, Nobuyuki
 
Affiliation
Faculty of Science and Engineering
Job title
Professor Emeritus

Education

  • 1974.04
    -
    1977.12

    Waseda University   Department of Physics and Applied Physics   Graduate School of Science and Engineering, Waseda University; Doctor Course  

  • 1972.04
    -
    1974.03

    Waseda University   Department of Physics and Applied Physics   Graduate School of Science and Engineering, Waseda University; Master Course  

  • 1968.04
    -
    1972.03

    Waseda University   Department of Applied Physics   Undergraduate School of Science and Engineering  

Degree

  • 早稲田大学   理学博士

Research Experience

  • 2015.01
    -
    Now

    National Research Nuclear University (MEPhI)   Visiting Professor:

  • 1998.09
    -
    2018.03

    Waseda University   Research Institute for Science and Engineering   Professor

  • 1997.09
    -
    1998.08

    Ehime Univ.   Faculty of Engineering, Ehime Univ.   Professor

  • 1995.04
    -
    1997.08

    Ehime Univ.   Faculty of Engineering,   Associate Professor

  • 1980.09
    -
    1995.03

    Ehime Univ.   Faculty of General Science   Associate Professor

  • 1979.04
    -
    1980.03

    Ehime Univ.   Faculty of General Science   Lecturer

  • 1978.01
    -
    1979.03

    Univ. of Tokyo   Institute for Cosmic Ray Res.   Research Assistant

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Professional Memberships

  •  
     
     

    Member of Society of Geomagnetism and Earth, Planetary and Space Sciences

  •  
     
     

    Member of Society of Exploration Geophysicists of Japan

  •  
     
     

    Member of Japanese Society for Planetary Sciences

  •  
     
     

    Member of Japan Society of Applied Physics

  •  
     
     

    Member of the Physical Society of Japan

 

Research Areas

  • Applied condensed matter physics   Radiation, Detector Physics

  • Space and planetary sciences

  • Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics   Astroparticle Physics

Research Interests

  • Radiation Detector Physics

  • asteroid

  • planet

  • space exploration

  • radiation

  • moon

  • neutron

  • nuclear

  • gamma-ray

  • cosmic ray

  • Radiation detector

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Papers

  • Radiation dose and its protection in the Moon from galactic cosmic rays and solar energetic particles: at the lunar surface and in a lava tube

    Masayuki Naito, Nobuyuki Hasebe, Mana Shikishima, Yoshiharu Amano, Junichi Haruyama, Jose A Matias-Lopes, Kyeong Ja Kim, Satoshi Kodaira

    Journal of Radiological Protection   40 ( 4 ) 947 - 961  2020.12

    DOI

  • Radiation dose and its protection in the Moon from galactic cosmic rays and solar energetic particles: At the lunar surface and in a lava tube

    Masayuki Naito, Nobuyuki Hasebe, Mana Shikishima, Yoshiharu Amano, Junichi Haruyama, Jose A. Matias-Lopes, Kyeong Ja Kim, Satoshi Kodaira

    Journal of Radiological Protection   40 ( 4 ) 947 - 961  2020.12

     View Summary

    © 2020 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved. The lunar surface is directly and continuously exposed to Galactic Cosmic ray (GCR) particles and Solar energetic particles (SEPs) due to the lack of atmosphere and lunar magnetic field. These charged particles interact with the lunar surface materials producing secondary radiations such as neutrons and gamma rays. In a departure from precise GCR and SEP data, we estimated the effective dose equivalent at the lunar surface and in a lunar lava tube in this paper by using PHITS, a Monte Carlo simulation tool. The effective dose equivalent due to GCR particles at the lunar surface reached 416.0 mSv yr-1 and that due to SEPs reached 2190 mSv/event. On the other hand, the vertical hole of the lava tube provides significant radiation protection. The exposure by GCR particles at the bottom of the vertical hole with a depth of 43 m was found to be below 30 mSv yr-1 while inside a horizontal lava tube, the value was less than 1 mSv yr-1 which is the reference value for human exposure on the Earth. We expect that the lunar holes will be useful components in the practical design of a lunar base to reduce radiation risk and to expand mission terms.

    DOI

  • Formation of ferroan dacite by lunar silicic volcanism recorded in a meteorite from the Moon

    H. Nagaoka, T.J. Fagan, M. Kayama, Y. Karouji, N. Hasebe, M. Ebihara

    Progress in Earth and Planetary Science     7 - 12  2020  [Refereed]

  • Measurement of electron multiplication and ionization coefficients in high-pressure xenon

    Hiroki Kusano, José A.Matias Lopes, Nobuyuki Hasebe

    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment   937   53 - 58  2019.09  [Refereed]

     View Summary

    © 2019 Elsevier B.V. Electron multiplication in high-pressure pure xenon was studied in the 0.5–3.0 MPa pressure range using a cylindrical proportional counter. The electron multiplication factor and the first Townsend ionization coefficient were determined, thus expanding collective knowledge beyond the previous studies, which were limited to 1.0 MPa. The measured electron multiplication factor falls between 15 and 2400 for the investigated pressure range. The density-reduced first Townsend ionization coefficient in this work is larger than that obtained for low-pressure xenon. In addition, the density-reduced first Townsend ionization coefficient was found to be density dependent. It was also found that the energy resolution deteriorates with increasing pressure. However, when the electron multiplication factor is several hundred, the energy resolution in high-pressure pure xenon was found to be better than that in commonly used xenon-based gas mixtures.

    DOI

  • Potassium and Thorium Abundances at the South Pole‐Aitken Basin Obtained by the Kaguya Gamma‐Ray Spectrometer

    M. Naito, N. Hasebe, H. Nagaoka, C. Wöhler, A. A. Berezhnoy, M. Bhatt, K. J. Kim

    Journal of Geophysical Research: Planets    2019.09  [Refereed]

    DOI

  • Direct Measurement of the Cosmic-Ray Proton Spectrum from 50 GeV to 10 TeV with the Calorimetric Electron Telescope on the International Space Station

    O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, E. Berti, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, P. Brogi, A. Bruno, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, K. Kohri, H. S. Krawczynski, J. F. Krizmanic, T. Lomtadze, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, S. Nakahira, J. Nishimura, G. A. De Nolfo, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, F. Palma, P. Papini, A. V. Penacchioni, B. F. Rauch, S. B. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, J. E. Suh, A. Sulaj, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, T. Terasawa, H. Tomida, S. Torii, Y. Tsunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida

    Physical Review Letters   122 ( 18 )  2019.05  [Refereed]

     View Summary

    © 2019 authors. In this paper, we present the analysis and results of a direct measurement of the cosmic-ray proton spectrum with the CALET instrument onboard the International Space Station, including the detailed assessment of systematic uncertainties. The observation period used in this analysis is from October 13, 2015 to August 31, 2018 (1054 days). We have achieved the very wide energy range necessary to carry out measurements of the spectrum from 50 GeV to 10 TeV covering, for the first time in space, with a single instrument the whole energy interval previously investigated in most cases in separate subranges by magnetic spectrometers (BESS-TeV, PAMELA, and AMS-02) and calorimetric instruments (ATIC, CREAM, and NUCLEON). The observed spectrum is consistent with AMS-02 but extends to nearly an order of magnitude higher energy, showing a very smooth transition of the power-law spectral index from-2.81±0.03 (50-500 GeV) neglecting solar modulation effects (or-2.87±0.06 including solar modulation effects in the lower energy region) to-2.56±0.04 (1-10 TeV), thereby confirming the existence of spectral hardening and providing evidence of a deviation from a single power law by more than 3σ.

    DOI PubMed

  • Alpha-particle spectrometer based on xenon gas ionization chamber using coplanar electrodes

    N. Hasebe, M. Miyajima, E. Shibamura, A. Hitachi, M. Naito, K. Murakami, H. Kusano, J.A. Matias-Lopes, V.V. Dmitrenko

    Nucl. Instr. Methods, Res. A   25   123 - 127  2019  [Refereed]

  • Measurements of electron mobility and longitudinal diffusion coefficient in high pressure xenon doped with hydrogen

    H. Kusano, M. Miyajima, N. Hasebe, V.V. Dmitrenko

    Jpn. J. Appl. Phys.   58   038001  2019  [Refereed]

  • Characteristics and Performance of the CALorimetric Electron Telescope (CALET) Calorimeter for Gamma-Ray Observations

    N. Cannady, Y. Asaoka, F. Satoh, M. Tanaka, S. Torii, M. L. Cherry, M. Mori, O. Adriani, Y. Akaike, K. Asano, M. G. Bagliesi, E. Berti, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, P. Brogi, J. H. Buckley, G. Castellini, C. Checchia, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, K. Kohri, H. S. Krawczynski, J. F. Krizmanic, T. Lomtadze, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, A. A. Moiseev, K. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, S. Nakahira, J. Nishimura, G. A.De Nolfo, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, F. Palma, P. Papini, A. V. Penacchioni, B. F. Rauch, S. B. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, J. E. Suh, A. Sulaj, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, Y. Tsunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida

    Astrophysical Journal, Supplement Series   238 ( 1 )  2018.09  [Refereed]

     View Summary

    © 2018. The American Astronomical Society. All rights reserved. The CALorimetric Electron Telescope primary detector (CALET-CAL) is a 30 radiation-length-deep hybrid calorimeter designed for the accurate measurement of high-energy cosmic rays. It is capable of triggering on and giving near complete containment of electromagnetic showers from primary electrons and gamma rays from 1 GeV to over 10 TeV. The first 24 months of on-orbit scientific data (2015 November 01-2017 October 31) provide valuable characterization of the performance of the calorimeter based on analyses of the gamma-ray data set in general and bright point sources in particular. We describe the gamma-ray analysis, the expected performance of the calorimeter based on Monte Carlo simulations, the agreement of the flight data with the simulated results, and the outlook for long-term gamma-ray observations with the CAL.

    DOI

  • Search for GeV Gamma-Ray Counterparts of Gravitational Wave Events by CALET

    O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, E. Berti, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, H. S. Krawczynski, J. F. Krizmanic, K. Kohri, T. Lomtadze, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, S. Nakahira, J. Nishimura, G. A. De Nolfo, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, F. Palma, P. Papini, A. V. Penacchioni, B. F. Rauch, S. B. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, J. E. Suh, A. Sulaj, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tsunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida

    Astrophysical Journal   863 ( 2 ) DOI: 10.3847/1538-4357/aad18f.  2018.08  [Refereed]

     View Summary

    © 2018. The American Astronomical Society. All rights reserved. We present the results of searches for gamma-ray counterparts of the LIGO/Virgo gravitational wave events using CALorimetric Electron Telescope (CALET) observations. The main instrument of CALET, CALorimeter (CAL), observes gamma-rays from ∼1 GeV up to 10 TeV with a field of view (FOV) of nearly 2 sr. In addition, the CALET gamma-ray burst monitor views ∼3 sr and ∼2π sr of the sky in the 7 keV-1 MeV and the 40 keV-20 MeV bands, respectively, by using two different crystal scintillators. The CALET observations on the International Space Station started in 2015 October, and here we report analyses of events associated with the following gravitational wave events: GW151226, GW170104, GW170608, GW170814, and GW170817. Although only upper limits on gamma-ray emission are obtained, they correspond to a luminosity of 1049 ∼ 1053 erg s-1 in the GeV energy band depending on the distance and the assumed time duration of each event, which is approximately on the order of luminosity of typical short gamma-ray bursts. This implies that there will be a favorable opportunity to detect high-energy gamma-ray emission in further observations if additional gravitational wave events with favorable geometry will occur within our FOV. We also show the sensitivity of CALET for gamma-ray transient events, which is on the order of 10-7 erg cm-2 s-1 for an observation of 100 s in duration.

    DOI

  • Iron distribution of the Moon observed by the Kaguya gamma-ray spectrometer: Geological implications for the South Pole-Aitken basin, the Orientale basin, and the Tycho crater

    M. Naito, N. Hasebe, H. Nagaoka, E. Shibamura, M. Ohtake, K. J. Kim, C. Wöhler, A. A. Berezhnoy

    Icarus   310 ( DOI: 10.1016/j.icarus.2017.12. ) 21 - 31  2018.08  [Refereed]

     View Summary

    In this study we describe the distribution of iron on the Moon as obtained by the Kaguya high energy resolution gamma-ray spectrometer (KGRS). We achieved for the first time the identification of iron based on the fast neutron flux obtained by the KGRS. The iron distribution obtained by KGRS is compared to that of the Lunar Prospector Gamma-Ray Spectrometer (LP GRS), showing that the FeO distributions observed by KGRS and LP GRS, in general, are in good agreement. Furthermore, we compare the iron content data obtained by KGRS and LP GRS to spectral reflectance measurements of the Clementine, Kaguya and Chandrayaan-1 spacecraft as well as those inferred from returned samples. We found differences in FeO concentration and distribution in areas of moderate abundance (6–15 wt%) of the South Pole-Aitken basin, Mare Orientale, and around the crater Tycho crater. It implies that high concentrations of FeO at Mare Ingenii in the South Pole-Aitken basin and Mare Orientale are due to the presence of mare basalts, whereas the enriched FeO content in the central depression of the South Pole-Aitken basin and the Tycho crater indicates the presence of mafic materials such as impact melt breccia.

    DOI

  • On-orbit operations and offline data processing of CALET onboard the ISS

    Y. Asaoka, S. Ozawa, S. Torii, O. Adriani, Y. Akaike, K. Asano, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, A. Javaid, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, H. S. Krawczynski, J. F. Krizmanic, S. Kuramata, T. Lomtadze, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, S. Nakahira, J. Nishimura, G. A. de Nolfo, S. Okuno, J. F. Ormes, L. Pacini, F. Palma, P. Papini, A. V. Penacchioni, B. F. Rauch, S. B. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, Y. Tsunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda

    Astroparticle Physics   100 ( 100(2018) ) 29 - 37  2018.07

     View Summary

    © 2018 Elsevier B.V. The CALorimetric Electron Telescope (CALET), launched for installation on the International Space Station (ISS) in August, 2015, has been accumulating scientific data since October, 2015. CALET is intended to perform long-duration observations of high-energy cosmic rays onboard the ISS. CALET directly measures the cosmic-ray electron spectrum in the energy range of 1 GeV to 20 TeV with a 2% energy resolution above 30 GeV. In addition, the instrument can measure the spectrum of gamma rays well into the TeV range, and the spectra of protons and nuclei up to a PeV. In order to operate the CALET onboard ISS, JAXA Ground Support Equipment (JAXA-GSE) and the Waseda CALET Operations Center (WCOC) have been established at JAXA and Waseda University, respectively. Scientific operations using CALET are planned at WCOC, taking into account orbital variations of geomagnetic rigidity cutoff. Scheduled command sequences are used to control the CALET observation modes on orbit. Calibration data acquisition by, for example, recording pedestal and penetrating particle events, a low-energy electron trigger mode operating at high geomagnetic latitude, a low-energy gamma-ray trigger mode operating at low geomagnetic latitude, and an ultra heavy trigger mode, are scheduled around the ISS orbit while maintaining maximum exposure to high-energy electrons and other high-energy shower events by always having the high-energy trigger mode active. The WCOC also prepares and distributes CALET flight data to collaborators in Italy and the United States. As of August 31, 2017, the total observation time is 689 days with a live time fraction of the total time of ∼ 84%. Nearly 450 million events are collected with a high-energy (E > 10 GeV) trigger. In addition, calibration data acquisition and low-energy trigger modes, as well as an ultra-heavy trigger mode, are consistently scheduled around the ISS orbit. By combining all operation modes with the excellent-quality on-orbit data collected thus far, it is expected that a five-year observation period will provide a wealth of new and interesting results.

    DOI

  • Extended Measurement of the Cosmic-Ray Electron and Positron Spectrum from 11 GeV to 4.8 TeV with the Calorimetric Electron Telescope on the International Space Station

    O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, E. Berti, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, K. Kohri, H. S. Krawczynski, J. F. Krizmanic, T. Lomtadze, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, S. Nakahira, J. Nishimura, G. A. De Nolfo, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, F. Palma, P. Papini, A. V. Penacchioni, B. F. Rauch, S. B. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, J. E. Suh, A. Sulaj, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tsunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida

    Physical Review Letters   120 ( 26 )  2018.06

     View Summary

    © 2018 American Physical Society. Extended results on the cosmic-ray electron + positron spectrum from 11 GeV to 4.8 TeV are presented based on observations with the Calorimetric Electron Telescope (CALET) on the International Space Station utilizing the data up to November 2017. The analysis uses the full detector acceptance at high energies, approximately doubling the statistics compared to the previous result. CALET is an all-calorimetric instrument with a total thickness of 30 X0 at normal incidence and fine imaging capability, designed to achieve large proton rejection and excellent energy resolution well into the TeV energy region. The observed energy spectrum in the region below 1 TeV shows good agreement with Alpha Magnetic Spectrometer (AMS-02) data. In the energy region below ∼300 GeV, CALET's spectral index is found to be consistent with the AMS-02, Fermi Large Area Telescope (Fermi-LAT), and Dark Matter Particle Explorer (DAMPE), while from 300 to 600 GeV the spectrum is significantly softer than the spectra from the latter two experiments. The absolute flux of CALET is consistent with other experiments at around a few tens of GeV. However, it is lower than those of DAMPE and Fermi-LAT with the difference increasing up to several hundred GeV. The observed energy spectrum above ∼1 TeV suggests a flux suppression consistent within the errors with the results of DAMPE, while CALET does not observe any significant evidence for a narrow spectral feature in the energy region around 1.4 TeV. Our measured all-electron flux, including statistical errors and a detailed breakdown of the systematic errors, is tabulated in the Supplemental Material in order to allow more refined spectral analyses based on our data.

    DOI PubMed

  • Vision System with High Performance Wide Angle Fovea Lens”; Proc. - 2018 IEEE 23rd International Conference on Emerging Technologies and Factory Automation, ETFA 2018 Sept., IEEE No.4(2018); Torino, Italy 20189.4-9.7.

    Rei Murakami, Sota Shimizu, Nobuyuki Hasebe

    Proc. 2018 IEEE 23rd International Conference on Emerging Technologies and Factory Automation, ETFA 2018 Sept., IEEE No.4(2018); Torino, Italy 20189.4-9.7.    2018.04  [Refereed]

  • Development of X-ray Generator for Active X-ray Fluorescence Spectroscopy of Future Lunar Landing Mission and Its Contribution to Lunar Science”

    H. Nagaoka, N. Hasebe, M. Naito, E, Shibamura, H. Kuno, M. Mizone, K.J. Kim

    Transaction of JSASS, Aerospace Technology Japan   Trans. JSASS 16 (2018) ( DOI: 10.2322/tastj.16.137 ) 137 - 142  2018  [Refereed]

  • Simulation of Gamma-ray and Neutron Spectrometers for Microsatellite Missions

    M. Naito, N. Hasebe, J. Ishii, J.A. Matias-Lopes, V.V. Dmirenko, C. Wohler

    J. Geosci. Environment Protection   6 ( DOI: 10.4236/gep.2018.68009 ) 84 - 111  2018  [Refereed]

  • Vision System with High Performance Wide Angle Fovea Lens

    Rei Murakami, Sota Shimizu, Nobuyuki Hasebe

    2018 IEEE 23rd International Conference on Emerging Technologies and Factory Automation, ETFA 2018 Sept., IEEE No.4(2018); Torino, Italy   20189 ( 4-9 ) 7  2018

  • Development of wide angle fovea telescope with wide-field-of-view immersive eyepiece

    Sota Shimizu, Nobuyuki Hasebe

    Proceedings IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society   2017-   8273 - 8278  2017.12  [Refereed]

     View Summary

    The authors have developed the wide angle fovea (WAF) telescope. This development was originally motivated from our mind to assist the ranger to save the people floating on the sea. Cruel Tsunami disasters often cause such miserable situations. An objective lens part of this special telescope was formerly developed using the Advanced WAF (AdWAF) model, by which we can design a distribution of the lens curve very flexibly. This special-made objective lens has an enough wide field of view, and thus it can keep a moving target as being always inside field of view. In addition, it can observe the target more in detail because its central field of view has higher magnification than the conventional telescope. Yes, this telescope is inspired from a smart function of the human eye to improve its availability. This special-made objective lens achieves not only wide-angle surveillance and but also detailed observation on the same time. Moreover, a special-made eyepiece lens part is also designed for users to observe environments with a more immersive feeling. This eyepiece utilizes a broader area on the human retina for the WAF telescope image projection. Indeed, the developed telescope has 22 aspherical surfaces of all 28 surfaces by using economy plastic lenses.

    DOI

  • Energy Spectrum of Cosmic-Ray Electron and Positron from 10 GeV to 3 TeV Observed with the Calorimetric Electron Telescope on the International Space Station

    O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, A. Javaid, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, H. S. Krawczynski, J. F. Krizmanic, S. Kuramata, T. Lomtadze, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, S. Nakahira, J. Nishimura, G. A. De Nolfo, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, F. Palma, P. Papini, A. V. Penacchioni, B. F. Rauch, S. B. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tsunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda

    Physical Review Letters   119 ( 18 )  2017.11

     View Summary

    © 2017 Published by the American Physical Society. First results of a cosmic-ray electron and positron spectrum from 10 GeV to 3 TeV is presented based upon observations with the CALET instrument on the International Space Station starting in October, 2015. Nearly a half million electron and positron events are included in the analysis. CALET is an all-calorimetric instrument with total vertical thickness of 30 X0 and a fine imaging capability designed to achieve a large proton rejection and excellent energy resolution well into the TeV energy region. The observed energy spectrum over 30 GeV can be fit with a single power law with a spectral index of -3.152±0.016 (stat+syst). Possible structure observed above 100 GeV requires further investigation with increased statistics and refined data analysis.

    DOI PubMed

  • Considerations about saliency map from Wide Angle Fovea image

    Tatsuya Yamazaki, Nobuyuki Hasebe, Sota Shimizu

    IEEE International Symposium on Industrial Electronics   IECON 2017 - 43rd Annual Confe   1330 - 1335  2017.08

     View Summary

    Wide Angle Fovea (WAF) sensor acquires images having both high resolution and wide angle simultaneously. Such an image is quite applicable for multi-purpose use of the single vision sensor. When the WAF sensor is equipped on a planetary exploring rover, it influences intuitively to the basic design and model of the rover which needs to be autonomous strongly. In this paper, the authors pay attention to difference between the saliency maps generated from the WAF image and the pinhole lens image. Thus, we compared and discussed the performance of our proposed object detection method between the WAF lens and the pinhole lens by taking into consideration characteristcs of the WAF image, i.e., non-uniform resolution throughout the entire field of view (FOV) and higher distortion in more peripheral FOV.

    DOI

  • The CALorimetric Electron Telescope (CALET) on the ISS

    Shoji Torii, for, the CALET Collaboration

    Preliminary results from on-orbit observations since October, 2015; Proceedings of Science (ICRC2017)   (ICRC2017)  2017.07

  • Energy calibration of CALET onboard the International Space Station

    Y. Asaoka, Y. Akaike, Y. Komiya, R. Miyata, S. Torii, O. Adriani, K. Asano, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, A. Javaid, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, H. Kitamura, H. S. Krawczynski, J. F. Krizmanic, S. Kuramata, T. Lomtadze, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, F. Palma, P. Papini, A. V. Penacchioni, B. F. Rauch, S. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, Y. Tsunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda

    Astroparticle Physics   91   1 - 10  2017.05  [Refereed]

     View Summary

    © 2017 The Authors In August 2015, the CALorimetric Electron Telescope (CALET), designed for long exposure observations of high energy cosmic rays, docked with the International Space Station (ISS) and shortly thereafter began to collect data. CALET will measure the cosmic ray electron spectrum over the energy range of 1 GeV to 20 TeV with a very high resolution of 2% above 100 GeV, based on a dedicated instrument incorporating an exceptionally thick 30 radiation-length calorimeter with both total absorption and imaging (TASC and IMC) units. Each TASC readout channel must be carefully calibrated over the extremely wide dynamic range of CALET that spans six orders of magnitude in order to obtain a degree of calibration accuracy matching the resolution of energy measurements. These calibrations consist of calculating the conversion factors between ADC units and energy deposits, ensuring linearity over each gain range, and providing a seamless transition between neighboring gain ranges. This paper describes these calibration methods in detail, along with the resulting data and associated accuracies. The results presented in this paper show that a sufficient accuracy was achieved for the calibrations of each channel in order to obtain a suitable resolution over the entire dynamic range of the electron spectrum measurement.

    DOI

  • Attitude Control of Drones by Back-Stepping Controller

    Shintaro Kiga, Shigeto Ouchi, Nobuyuki Hasebe, Nariyuki Kodani, Yuki Takamoto, Marizan Mubin

    2017 56TH ANNUAL CONFERENCE OF THE SOCIETY OF INSTRUMENT AND CONTROL ENGINEERS OF JAPAN (SICE)   DOI: 10.23919/SICE.2017.810543   25 - 30  2017

     View Summary

    The drones are used for many purposes such as structure inspections, pesticide sprayings, photographys, load carriages and investigations in the world. The drones have a week point that it is difficult to fly them in the strong wind. However, it is an important task to fly in the strong wind for the disaster relieves. In this paper, we show the modeling and the attitude control system design of a drone by using a back-stepping controller, and good performances are shown in simulations.

  • A three end-member model for petrologic analysis of lunar prospector gamma-ray spectrometer data

    S. Shimizu, N. Hasebe

    IECON2017 -43rd Annual Conference of the IEEE Industrial Electonics Society ,the IEEE Industrial Electonics Society ,     8273 - 8278  2017

  • A high performance neutron spectrometer for planetary hydrogen measurement

    Masayuki Naito, Nobuyuki Hasebe, Hiroshi Nagaoka, Junya Ishii, Daisuke Aoki, Eido Shibamura, Kyeong J. Kim, José A. Matias-Lopes, Jesús Martínez-Frías

    Proceedings of SPIE - The International Society for Optical Engineering   10392  2017

     View Summary

    The elemental composition and its distribution on planetary surface provide important constraints on the origin and evolution of the planetary body. The nuclear spectrometer consisting of a neutron spectrometer and a gamma-ray spectrometer obtains elemental compositions by remote sensing. Especially, the neutron spectrometer is able to determine the hydrogen concentration, a piece of information that plays an important role in thermal history of the planets. In this work, numerical and experimental studies on the neutron spectrometer for micro-satellite application were conducted. It is found that background count rate of neutron produced from micro-satellite is very small, which enables to obtain successful results in short time observation. The neutron spectrometer combining a lithium-6 glass scintillator with a boron loaded plastic scintillator was used to be able to detect neutrons in different energy ranges. It was experimentally confirmed that the neutron signals from these scintillators were successfully discriminated by the difference of scintillation decay time between two detectors. The measurement of neutron count rates of two scintillators is found to determine hydrogen concentration on the planetary surfaces in the future missions.

    DOI

  • Improved pyroelectric x-ray generator for planetary active x-ray spectroscopy

    Masayuki Naito, Nobuyuki Hasebe, Hiroshi Nagaoka, Yusuke Oshima, Miho Mizone, Eido Shibamura, Haruyoshi Kuno, Kyeong J. Kim, José A. Matias-Lopes, Jesús Martínez-Frías

    Proceedings of SPIE - The International Society for Optical Engineering   10392 ( ; doi: 10.1117/12.2273773 )  2017

     View Summary

    The elemental composition on planetary surface provides us an essential information to improve geological and geochemical understanding of planets. An active X-ray spectrometer (AXS) was developed and proposed as one of the mission payloads to perform in-situ X-ray fluorescence analysis. The AXS consists of multiple pyroelectric X-ray generators (PXGs) and a silicon drift detector (SDD). Although the PXG is light in weight and low in electric consumption, the limited X-ray intensity and reproducibility hamper obtaining the elemental composition by short time observation. This is attributed mainly to the less known mechanism of X-ray and electron emission by the pyroelectric crystal. In this study, we observed the crystal surface during X-ray emission as a function of the distance between the crystal top and a Cu target. Two types of light emission derived from the electric discharge were observed. The dependence of light emission on the distance was found to be related with the physical mechanism of pyroelectric X-ray emission. The study provides clues to obtain high intensity and reproducible X-rays emission. The experimental results and discussion are presented in this paper.

    DOI

  • Nuclear Spectroscopy for Unveiling the Origin of the Martian Moons”

    N. Hasebe

      2017-k-54, 2017.  2017

  • Current Development Status of a Gamma-Ray Spectrometer for the Korea Pathfinder Lunar Orbiter”

    K.J. Kim, Y. Choi, J. Park, E.S. Yi, S. Lee, Y. Yeon, C.W. Sun, K.B. Lee, Y. Kim, K. Min, K. Kang, J.Y. Cho, J.H. Cha, N. Hasebe, R. Elphic, P. Englert, O. Gasnault, E. Shibamura, H. Nagaoka, L. Lim

    International Symposium on Space Technology and Science, ISTS Web Paper Archives, 2017-k-28, 2017   2017-k-28  2017  [Refereed]

  • S. Shimizu and N. Hasebe

    Development of, wide angle, fovea telescope with, wide-field-of-view, immersive eyepiece

    IECON2017 -43rd Annual Conference of the IEEE Industrial Electonics Society     8273 - 8278  2017

  • A nuclear spectrometer aboard microsatellites for nearearth asteroids exploration

    N. Hasebe, H. Nagaoka, M. Naito, J. Ishii, M. Shikishima, E. Shibamura, S. Torii, M. Miyashita, S. Shimizu, V.V. Dmitrenko, S. Ulin, V. Grachov, J.A. Matias-Lopes, J. Martinez-Frias, K.J. Kim

    EPSC 11(2017)   206-1.  2017  [Invited]

  • CALET on the ISS: a high energy astroparticle physics experiment; Journal of Physics

    Pier Simone, Marrocchesi et al, CALET Collaboration

    Conference Series (TAUP 2015)   718(052023)   1 - 5  2016.10  [Refereed]

  • CALET UPPER LIMITS on X-RAY and GAMMA-RAY COUNTERPARTS of GW151226

    O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, A. Javaid, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, H. Kitamura, H. S. Krawczynski, J. F. Krizmanic, S. Kuramata, T. Lomtadze, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, F. Palma, P. Papini, A. V. Penacchioni, B. F. Rauch, S. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tsunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda

    Astrophysical Journal Letters   829 ( 1 )  2016.09

     View Summary

    © 2016. The American Astronomical Society. All rights reserved.. We present upper limits in the hard X-ray and gamma-ray bands at the time of the Laser Interferometer Gravitational-wave Observatory (LIGO) gravitational-wave event GW151226 derived from the CALorimetric Electron Telescope (CALET) observation. The main instrument of CALET, CALorimeter (CAL), observes gamma-rays from ∼1 GeV up to 10 TeV with a field of view of ∼2 sr. The CALET gamma-ray burst monitor (CGBM) views ∼3 sr and ∼2π sr of the sky in the 7 keV-1 MeV and the 40 keV-20 MeV bands, respectively, by using two different scintillator-based instruments. The CGBM covered 32.5% and 49.1% of the GW151226 sky localization probability in the 7 keV-1 MeV and 40 keV-20 MeV bands respectively. We place a 90% upper limit of 2 ×10-7 erg cm-2 s-1 in the 1-100 GeV band where CAL reaches 15% of the integrated LIGO probability (∼1.1 sr). The CGBM 7σ upper limits are 1.0 ×10-6 erg cm-2 s-1 (7-500 keV) and 1.8 ×10-6 erg cm-2 s-1 (50-1000 keV) for a 1 s exposure. Those upper limits correspond to the luminosity of 3-5 ×1049 erg s-1, which is significantly lower than typical short GRBs.

    DOI

  • A performance test of a new high-surface-quality and high-sensitivity CR-39 plastic nuclear track detector - TechnoTrak

    S. Kodaira, K. Morishige, H. Kawashima, H. Kitamura, M. Kurano, N. Hasebe, Y. Koguchi, W. Shinozaki, K. Ogura

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS   383   129 - 135  2016.09  [Refereed]

     View Summary

    We have studied the performance of a newly-commercialized CR-39 plastic nuclear track detector (PNTD), "TechnoTrak", in energetic heavy ion measurements. The advantages of TechnoTrak are derived from its use of a purified CR-39 monomer to improve surface quality combined with an antioxidant to improve sensitivity to low-linear-energy-transfer (LET) particles. We irradiated these detectors with various heavy ions (from protons to krypton) with various energies (30-500 MeV/u) at the heavy ion accelerator facilities in the National Institute of Radiological Sciences (NIRS). The surface roughness after chemical etching was improved to be 59% of that of the conventional high-sensitivity CR-39 detector (HARZLAS/TD-1). The detectable dynamic range of LET was found to be 3.5-600 keV/m. The LET and charge resolutions for three ions tested ranged from 5.1% to 1.5% and 0.14 to 0.22 c.u. (charge unit), respectively, in the LET range of 17-230 keV/mu m, which represents an improvement over conventional products (HARZLAS/TD-1 and BARYOTRAK). A correction factor for the angular dependence was determined for correcting the LET spectrum in an isotropic radiation field. We have demonstrated the potential of TechnoTrak, with its two key features of high surface quality and high sensitivity to low-LET particles, to improve automatic analysis protocols in radiation dosimetry and various other radiological applications. (C) 2016 Elsevier B.V. All rights reserved.

    DOI

  • Estimation method of planetary fast neutron flux by a Ge gamma-ray spectrometer

    M. Hareyama, Y. Fujibayashi, Y. Yamashita, Y. Karouji, H. Nagaoka, S. Kobayashi, R. C. Reedy, O. Gasnault, O. Forni, C. d'Uston, K. J. Kim, N. Hasebe

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   828   145 - 155  2016.08

     View Summary

    An intensity map of lunar fast neutrons (LFNs) and their temporal variation has been estimated by fitting "sawtooth" peaks in the energy spectra of lunar gamma rays observed by the Kaguya (SELENE) Gamma Ray Spectrometer (GRS) consisting of a high-purity germanium (HPGe) detector with a BGO scintillator. While an ordinary peak in the spectrum is produced by only gamma ray lines, the sawtooth peak is produced by gamma ray lines and recoil nuclei in the detector by Ge(n, n'gamma) reaction. We develop a model for the shape of the sawtooth peak and apply it to fit sawtooth peaks together with ordinary peaks in actual observed spectra on the Moon. The temporal variation of LENs is synchronous with that of galactic cosmic rays (GCRs), and the global distribution of fast neutrons on the lunar surface agrees well with the past observation reported by the Neutron Spectrometer aboard Lunar Prospector. Based on these results, a new method is established to estimate the flux of fast neutrons by fitting sawtooth peaks on the gamma ray spectrum observed by the HPGe detector. (C) 2016 Elsevier B.V. All rights reserved.

    DOI

  • Tessellation for Wide Angle Foveated Image with 4 Regions based on Overlapping Circular Receptive Field Mapping

    Sota Shimizu, Nobuyuki Hasebe

    PROCEEDINGS OF THE IECON 2016 - 42ND ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY   6187-6192 (6) (2015)7793888.   6187 - 6192  2016

     View Summary

    As well-known, the human single eye has a horizontally approximately 120-degree wide FOV. Its FOV is wide, but only its central FOV has high visual acuity. Visual acuity in its peripheral FOV is very low. By changing its view line into a target, the human can observe it in detail by its central FOV and simultaneously can observe the whole of environment by its wide FOV. This means that the human eye performs a smart data acquisition, i.e., getting more detailed visual information with smaller data amount from environment by combining appropriate eye movements. WAFVS was investigated taking into account the above human eye's functionality. The most characterized point of WAFVS is of the resolution-variant input image data, i.e., this vision sensor gets a wide-angle image where spatial resolution is not uniform like the human visual acuity. Therefore, WAFVS can reduce image data hugely. This is a strong advantage when image data are transmitted and recorded in a storage device when the vision sensor is applied for remote operation. In this paper, a remapping method for WAFVS is proposed and implemented, i.e., tessellation for Wide Angle Foveated image with 4 regions based on overlapping circular RF mapping.

    DOI

  • Mission Concepts of Unprecedented Zipangu Underworld of the Moon Exploration (UZUME) Project”

    J. Haruyama, I. Kawano, T. Kubota, M. Otsuki, H. Kato, T. Nishibori, T. Iwata, Y. Yamamoto, Y. Ishihara, A. Nagamatsu, K. Shimada, T. Hasenaka, T. Morota, M. Nishino, K. Hashizume, K. Saiki, M. Shira, G. Komatsu, N. Hasebe, H. Shimizu, H. Miyamoto, K. Kobayashi, S. Yokobori, T. Michikami, S. Yamamoto, Y. Yokota, H. Arisumi, G. Ishigami, K. Furutani, Y. Michikawa

    Transaction of the Japan Society fir Aeronautical and Space Sciences, Aerospace Technology Japan,   14(2016)   147 - 150  2016

  • Development of Gas Ionization Chambers with Coplanar Electrode for Alpha-ray Spectrometry”

    K. Iwasaki, N. Tanaka, K. Murakami, K. Hiroki, E. Shibamura, N. Hasebe, M. Miyajima

    2016, JPS Conf. Proc. 11, 010003, 10.7566/JPSCP.11.010003.    2016  [Refereed]

  • Current Development Status of an X-ray Generator for X-ray Fluorescence Analysis on Space Mission”,

    H. Kusano, N. Hasebe, H. Nagaoka, M. Naito, M. Mizone, Y. Amano, E. Shibamura, H. Kusno

    JPS Conf. Proc. 040005 (2016)   https://doi.org/10.7566/JPSCP.  2016

  • Instrumental Overview of an Active X-ray Spectrometer for Future Lunar Landing Mission”,

    H. Nagaoka, N. Hasebe, H. Kusano, Y. Amano, E. Shibamura, T. Ohta, T. J. Fagan, M. Naito, H. Kuno, J. A. Matias- Lopes

    JPS Conf. Proc. 040004 (2016),   https://doi.org/10.7566/JPSCP.  2016

  • Neutron Fluxes from Martian Satellites as a Function of Chemical Composition and Hydrogen Content”,

    M. Naito, N. Hasebe, K. Yoshida, J. Ishii, D. Aoki, H. Nagaoka, H. Kusano, E. Shibamura

    JPS Conf. Proc. 050003 (2016),   https://doi.org/10.7566/JPSCP.  2016

  • Gamma-Ray Emission from the Surface of Martian Satellites as a Function of Elemental Composition”

    K. Yoshida, M. Naito, N. Hasebe, H. Kusano, H. Nagaoka, J. Ishida, D. Aoki

    JPS Conf. Proc. 040007 (2016)   https://doi.org/10.7566/JPSCP.  2016

  • An Investigation of Elemental Composition of Martian Satellites by Gamma-ray and Neutron Spectrometer”

    N. Hasebe, T. Ohta, Y. Amano, M. Naito, H. Kusano, H. Nagaoka, K. Yoshida, T. Adachi, T. J. Fagan

    2016, JPS Conf. Proc. 11, 040006,   doi: http://dx.doi.org/10.7566  2016

  • X-ray fluorescence spectrometer for planetary exploration”

    N. Hasebe, H. Kusano, H. Nagaoka

    Adv. X-ray. Chem. Anal., Japan   47(2016)   59 - 77  2016

  • Two-stage development of the lunar farside highlands crustal formation

    Keiko Yamamoto, Junichi Haruyama, Shingo Kobayashi, Makiko Ohtake, Takahiro Iwata, Yoshiaki Ishihara, Nobuyuki Hasebe

    PLANETARY AND SPACE SCIENCE   120   43 - 47  2016.01

     View Summary

    The correlation between the spatial patterns of surface Thorium (Th) abundance measured by SELENE GRS data and the crustal thickness from the GRAIL gravity field and LRO LOLA data is investigated in the lunar highland area. Our analysis reveals that there are several areas of local minima for Th abundance exhibiting similar values but different crustal thicknesses. To explain the result, we propose a two-stage scenario for crustal formation. In the first stage, plural thin plateaus form on the surface of the lunar magma ocean (LMO), which corresponds to the observed surface Th distribution. In the second stage, a global crust with dichotomy forms by solidification of the LMO under the plateaus. (C) 2015 Elsevier Ltd. All rights reserved.

    DOI

  • 惑星探査における蛍光X線分光”

    長谷部 信行, 草野広樹, 長岡央

    X線分析の進歩   47(2016)   59 - 77  2016

  • Development of wide-angle vision system for remote navigation of planetary exploring rover - Accuracy evaluation method of camera view direction control using eye-tracking device

    Sota Shimizu, Kazuki Nakamura, Nobuyuki Hasebe

    IEEJ Transactions on Industry Applications   135 ( 12 ) 1138 - 1143  2015.12

     View Summary

    Wide-Angle Fovea Vision Sensor (WAFVS) system, inspired by the functionality of the human eye, was designed and developed to allow single vision sensors to be used for multiple purposes. The authors think that the WAFVS system is suitable for use in planetary exploring rovers, because one of severe problems in the vision systems of rovers, UAVs and satellites involves the management of payloads. This paper describes the multi-purpose utilization of the WAFVS system, which includes the following tasks: (1) observing the environment displayed to the operator to allow the remote navigation of the rover, (2) recording images of important scenes by changing the view direction of the WAFVS, and (3) monitoring whether the instruments on the rover work correctly. Moreover, this paper includes experiments and discusses a technique to display images to the operator when an eye-tracking device is applied as a target coordinate input device, in order to assist the operator with their tasks. An accuracy index, i.e., a measurement error of a target, is defined in order to evaluate the performance of a combination that incorporates the vision sensor, the coordinate input device, and the image display method.

    DOI

  • Mineralogy and petrology of lunar meteorite Northwest Africa 2977 consisting of olivine cumulate gabbro including inverted pigeonite

    Hiroshi Nagaoka, Yuzuru Karouji, Hiroshi Takeda, Timothy J. Fagan, Mitsuru Ebihara, Nobuyuki Hasebe

    EARTH PLANETS AND SPACE   67  2015.12

     View Summary

    Lunar meteorite Northwest Africa (NWA) 2977 is identified as an olivine cumulate gabbro (OC), consisting of coarse cumulate olivine crystals up to 1 mm with low-Ca and high-Ca pyroxenes, plagioclase, and interstitial incompatible element-rich pockets of K-feldspar, Ca-phosphates, ilmenite, and troilite. These minerals and textures are similar to those of the OC clasts of the NWA 773 clan of meteorites. NWA 2977 contains a variety of pyroxene textures and compositions including augite, pigeonite, and rare orthopyroxene, all having exsolution lamellae. Some of the orthopyroxene has abundant augite lamellae with compositions indicating formation by inversion of pigeonite. This pigeonite was inverted at 1140 degrees C according to the pigeonite eutectoid reaction (PER) temperatures. Inverted pigeonite has not been found previously in the NWA 773 clan of meteorites. The presence of inverted pigeonite indicates that NWA 2977 cooled more slowly than most other OC clasts of the NWA 773 clan. The relatively slow cooling of NWA 2977 can be explained by formation in a deeper level of the original igneous body of the NWA 773 clan OC lithology.

    DOI

  • Parameters of 500 MeV/u Fe-56 tracks in bubble detector (BD) T-15-A new technique to estimate the number and diameter of superheated droplets in bubble detectors

    S. -L. Guo, T. Doke, D. -H. Zhang, B. -L. Chen, L. Li, N. Hasebe, J. Kikuchi, N. Yasuda, T. Murakami

    RADIATION MEASUREMENTS   83   5 - 11  2015.12  [Refereed]

     View Summary

    Extra length and large sized bubble detectors (BD) of Type T-15 have been irradiated with 500 MeV/u Fe-56 ions at HIMAC accelerator in the National Institute of Radiological Sciences (NIRS), Chiba, Japan. Linear tracks composed of regular arrays of tiny bubbles are visible by the naked eyes. The total length of each track is longer than 4.2 cm. In each track there are commonly more than 24 bubbles. The gap distance (or called pitch distance) between two neighboring bubbles in a track has been measured and analyzed, which reflects the distance between the two invisible superheated droplets that form the visible bubbles. The gap distance is related to the volume ratio of the superheated liquid (Freon-115) droplets to the whole sensitive volume of the detector and to the sizes of the droplets of the superheated liquid. A technique has been developed to deduce the average diameter of superheated droplets and to derive the number of the droplets in unit volume of the detector. A method to calibrate bubble detectors with high-energy heavy ions at accelerators is advanced, which is similar to that of calibration of solid state nuclear track detectors (SSNTD) at accelerators. Feasible ranges of the percentage volume of superheated liquid being 10(-4)-10(-1), droplet diameter 1-10(3) mu m, and droplet number density 1-10(11) cm(-3) in bubble detectors are outlined according to the experiences of the authors. These techniques and method will facilitate the development and applications of bubble detectors. (C) 2015 Elsevier Ltd. All rights reserved.

    DOI

  • The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

    O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, J. H. Buckley, G. Castellini, M. L. Cherry, G. Collazuol, K. Ebisawa, V. Di Felice, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, M. H. Israel, A. Javaid, E. Kamioka, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, N. Kawanaka, H. Kitamura, T. Kotani, H. S. Krawczynski, J. F. Krizmanic, A. Kubota, S. Kuramata, T. Lomtadze, P. Maestro, L. Marcelli, P. S. Marrocchesi, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, F. Palma, P. Papini, B. F. Rauch, S. B. Ricciarini, T. Sakamoto, M. Sasaki, M. Shibata, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda

    Journal of Physics: Conference Series   632 ( 1 )  2015.08  [Refereed]

     View Summary

    © Published under licence by IOP Publishing Ltd. The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF).

    DOI

  • Future lunar mission Active X-ray Spectrometer development: Surface roughness and geometry studies

    M. Naito, N. Hasebe, H. Kusano, H. Nagaoka, M. Kuwako, Y. Oyama, E. Shibamura, Y. Amano, T. Ohta, K. J. Kim, J. A. M. Lopes

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   788   182 - 187  2015.07

     View Summary

    The Active X-ray Spectrometer (AXS) is considered as one of the scientific payload candidates for a future Japanese mission, SELENE-2. The AXS consists of pyroelectric X-ray generators and a Silicon Drift Detector to conduct X-Ray Fluorescence spectroscopy (XRF) on the Moon to measure major elements: Mg, Al, Si, Ca, Ti, and Fe; minor elements: Na, K, F, S, Cr and Mn; and the trace element Ni depending on their concentration. Some factors such as roughness, grain size and porosity of sample, and the geometry of X-ray incidence, emission and energy will affect the XRF measurements precision. Basic studies on the XRF are required to develop the AXS. In this study, fused samples were used to make homogeneous samples free from the effect of grain size and porosity. Experimental and numerical studies on the XRF were conducted to evaluate the effects from incidence and emission angles and surface roughness. Angle geometry and surface roughness will be optimized for the design of the AXS on future missions from the results of the experiment and the numerical simulation. (C) 2015 Elsevier B.V. All rights reserved.

    DOI

  • 21pDD-13 Development of stacked silicon strip detectors for MeV electron on board the Geospace exploration satellite "ERG"

    Mitani T., Kasahara S., Takashima T., Hirahara M., Miyake W., Hasebe N.

    Meeting Abstracts of the Physical Society of Japan   70   417 - 417  2015

    DOI CiNii

  • The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

    O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, J. H. Buckley, G. Castellini, M. L. Cherry, G. Collazuol, K. Ebisawa, V. Di Felice, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, M. H. Israel, A. Javaid, E. Kamioka, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, N. Kawanaka, H. Kitamura, T. Kotani, H. S. Krawczynski, J. F. Krizmanic, A. Kubota, S. Kuramata, T. Lomtadze, P. Maestro, L. Marcelli, P. S. Marrocchesi, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, F. Palma, P. Papini, B. F. Rauch, S. B. Ricciarini, T. Sakamoto, M. Sasaki, M. Shibata, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda

    3RD INTERNATIONAL CONFERENCE ON NEW FRONTIERS IN PHYSICS   95  2015

     View Summary

    The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF).

    DOI

  • The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

    O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, J. H. Buckley, G. Castellini, M. L. Cherry, G. Collazuol, K. Ebisawa, V. Di Felice, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, M. H. Israel, A. Javaid, E. Kamioka, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, N. Kawanaka, H. Kitamura, T. Kotani, H. S. Krawczynski, J. F. Krizmanic, A. Kubota, S. Kuramata, T. Lomtadze, P. Maestro, L. Marcelli, P. S. Marrocchesi, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, F. Palma, P. Papini, B. F. Rauch, S. B. Ricciarini, T. Sakamoto, M. Sasaki, M. Shibata, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda

    3RD INTERNATIONAL CONFERENCE ON NEW FRONTIERS IN PHYSICS   95  2015

     View Summary

    The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF).

    DOI

  • The Development of X-Ray Generator with a Pyroelectric Crystal for Future Planetary Exploration”

    H. Nagaoka, N. Hasebe, H. Kusano, Y. Oyama, M. Naito, E. Shibamura, H. Kuno

    Adv. X-ray. Chem. Anal., Japan,   46 (2015)   347 - 354  2015

  • Mineralogy of some evolved LL chondrites with reference to asteroid materials and solar system evolution

    Hiroshi Takeda, Hiroshi Nagaoka, Akira Yamaguchi, Yuzuru Karouji, Yuuki Yazawa

    EARTH PLANETS AND SPACE   67   5, doi:10.1186/s40623  2015.01

     View Summary

    Mineralogy of three LL chondrites including Y-981971, Y-793214, and Y-790782 indicates that granulitic materials may have been formed in some depth of their parent body by an impact event. This process of high-temperature episodes is different from the records in the differentiated achondrites (howardite-eucrite-diogenite (HED)) possibly from the Vesta-like asteroid.

    DOI

  • Status and performance of the CALorimetric Electron Telescope (CALET) on the international space station

    O. Adriani, Y. Akaike, Y. Asaoka, K. Asano, M. G. Bagliesi, G. Bigongiari, W. R. Binns, M. Bongi, J. H. Buckley, A. Cassese, G. Castellini, M. L. Cherry, G. Collazuol, K. Ebisawa, V. di Felice, H. Fuke, T. G. Guzik, T. Hamsa, N. Hasebe, M. Hareyama, K. Hibino, M. Ichimura, K. Ioka, M. H. Israel, A. Javaid, E. Kamioka, K. Kasahara, Y. Katayose, J. Kataoka, R. Kataoka, N. Kawanaka, H. Kitamura, T. Kotani, H. S. Krawczynski, J. F. Krizmanic, A. Kubota, S. Kuramata, T. Lomtadze, P. Maestro, L. Marcelli, P. S. Marrocchesi, J. W. Mitchell, S. Miyake, K. Mizutani, H. M. Motz, A. A. Moiseev, K. Mori, M. Mori, N. Mori, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, F. Palma, P. Papini, B. F. Rauch, S. Ricciarini, T. Sakamoto, M. Sasaki, M. Shibata, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda

    Nuclear Physics B - Proceedings Supplements   256-257   225 - 232  2014.12  [Refereed]

     View Summary

    © 2014 Elsevier B.V. The CALorimetric Electron Telescope (CALET) space experiment, currently under development by Japan in collaboration with Italy and the United States, will measure the flux of cosmic-ray electrons (including positrons) to 20 TeV, gamma rays to 10 TeV and nuclei with Z=1 to 40 up to 1,000 TeV during a two-year mission on the International Space Station (ISS), extendable to five years. These measurements are essential to search for dark matter signatures, investigate the mechanism of cosmic-ray acceleration and propagation in the Galaxy and discover possible astrophysical sources of high-energy electrons nearby the Earth. The instrument consists of two layers of segmented plastic scintillators for the cosmic-ray charge identification (CHD), a 3 radiation length thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 radiation length thick lead-tungstate calorimeter (TASC). CALET has sufficient depth, imaging capabilities and excellent energy resolution to allow for a clear separation between hadrons and electrons and between charged particles and gamma rays. The instrument will be launched to the ISS within 2014 Japanese Fiscal Year (by the end of March 2015) and installed on the Japanese Experiment Module-Exposed Facility (JEM-EF). In this paper, we will review the status and main science goals of the mission and describe the instrument configuration and performance.

    DOI

  • Application of Ag+-doped phosphate glasses as nuclear track etch detectors

    Satoshi Kodaira, Yuka Miyamoto, Yasuhiro Koguchi, Daisuke Maki, Hajime Shinomiya, Keisuke Hanaoka, Nobuyuki Hasebe, Hajime Kawashima, Mieko Kurano, Hisashi Kitamura, Yukio Uchihori, Koichi Ogura

    RADIATION MEASUREMENTS   71   537 - 540  2014.12

     View Summary

    The Ag+-doped phosphate glass which is commonly employed as the radiophotoluminscence (RPL) dosimeter has been applied as a nuclear track etch detector. The glass is etchable in the NaOH solutions and forms clear nuclear etch pit. The etching performances and track parameters vary as a function of the concentration of NaOH solution. The most sensitive normality was confirmed to be 7 N. The track response is controllable with NaOH concentration at the range of Z*/beta >= 80 (Z*: effective charge, beta: velocity). The charge spectroscopic resolution for Xe (Z*/beta = 107) was found to be 0.23 cu (charge unit), which would allow to identify individual nuclear charge of ultra heavy nuclei around Actinides in the cosmic rays. The Ag+-doped phosphate glass would be a promising detector for high Z spectroscopy for cosmic ray and nuclear physics fields and has the potential to operate not only RPL dosimeter but also nuclear track etch detector. (C) 2014 Elsevier Ltd. All rights reserved.

    DOI

  • Depth dependency of neutron density produced by cosmic rays in the lunar subsurface

    S. Ota, L. Sihver, S. Kobayashi, N. Hasebe

    ADVANCES IN SPACE RESEARCH   54 ( 10 ) 2114 - 2121  2014.11

     View Summary

    Depth dependency of neutrons produced by cosmic rays (CRs) in the lunar subsurface was estimated using the three-dimensional Monte Carlo particle and heavy ion transport simulation code, PHITS, incorporating the latest high energy nuclear data, JENDL/HE-2007. The PHITS simulations of equilibrium neutron density profiles in the lunar subsurface were compared with the measurement by Apollo 17 Lunar Neutron Probe Experiment (LNPE). Our calculations reproduced the LNPE data except for the 350-400 mg/cm(2) region under the improved condition using the CR spectra model based on the latest observations, well-tested nuclear interaction models with systematic cross section data, and JENDL/HE-2007. (C) 2014 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • Implications for the origins of pure anorthosites found in the feldspathic lunar meteorites, Dhofar 489 group

    Hiroshi Nagaoka, Hiroshi Takeda, Yuzuru Karouji, Makiko Ohtake, Akira Yamaguchi, Shigekazu Yoneda, Nobuyuki Hasebe

    EARTH PLANETS AND SPACE   66   115, doi:10.1186/1880  2014.09

     View Summary

    Remote observation by the reflectance spectrometers onboard the Japanese lunar explorer Kaguya (SELENE) showed the purest anorthosite (PAN) spots (>98% plagioclase) at some large craters. Mineralogical and petrologic investigations on the feldspathic lunar meteorites, Dhofar 489 and Dhofar 911, revealed the presence of several pure anorthosite clasts. A comparison with Apollo nearside samples of ferroan anorthosite (FAN) indicated that of the FAN samples returned by the Apollo missions, sample 60015 is the largest anorthosite with the highest plagioclase abundance and homogeneous mafic mineral compositions. These pure anorthosites (>98% plagioclase) have large chemical variations in Mg number (Mg# = molar 100 x Mg/(Mg + Fe)) of each coexisting mafic mineral. The variations imply that these pure anorthosites underwent complex formation processes and were not formed by simple flotation of plagioclase. The lunar highland samples with pure anorthosite and the PAN observed by Kaguya suggest that pure anorthosite is widely distributed as lunar crust lithology over the entire Moon.

    DOI

  • Mona Lisa might be displeased?

    Sota Shimizu, Takumi Hashizume, Shuu Ichi Kikuchi, Nobuyuki Hasebe, Hiroki Kusano

    10th France-Japan Congress, 8th Europe-Asia Congress on Mecatronics, MECATRONICS 2014     279 - 284  2014.01

     View Summary

    © 2014 IEEE. This paper presents a developed experimental system using an eye-tracking device, by which we can control displayed visual stimuli flexibly like visual trick. Using this system, comparisons between two faces with different expressions are experimented in a specific condition as one face is always forced to display as in the subject's central field of view, while another face is always displayed in his/her peripheral field of view. The results have proved that ability of discriminate faces in the peripheral field of view is quite poor. In addition, the experimental results indicate how we could live our daily lives more peacefully.

    DOI

  • Mona Lisa might be displeased? Emotion Propagation from Central Field of View to Periphery in the Brain

    Sota Shimizu, Takumi Hashizume, Shuu-ichi Kikuchi, Nobuyuki Hasebe, Hiroki Kusano

    2014 10TH FRANCE-JAPAN/ 8TH EUROPE-ASIA CONGRESS ON MECATRONICS (MECATRONICS)     285 - 290  2014  [Refereed]

     View Summary

    This paper presents a developed experimental system using an eye-tracking device, by which we can control displayed visual stimuli flexibly like visual trick. Using this system, comparisons between two faces with different expressions are experimented in a specific condition as one face is always forced to display as in the subject's central field of view, while another face is always displayed in his/her peripheral field of view. The results have proved that ability of discriminate faces in the peripheral field of view is quite poor. In addition, the experimental results indicate how we could live our daily lives more peacefully.

  • Unprecedented Zipangu Underworld of the Moon Exploration (UZUME)

    Haruyama, J, Kawano, I, Kubota, T, Otsuki, M, Kato, H, Nishibori, T, Iwata, T, Yamamoto, Y, Nagamatsu, A, Shimada, K, Ishihara, Y, Hasenaka, T, Morota, T, Nishino, M. N, Hashizume, K, Saiki, K, Shirao, M, Komatsu, G, Hasebe, N, Shimizu, H, Miyamoto, H, Kobayashi, K, Yokobori, S, Michikami, T, Yamamoto, S, Yokota, Y, Arisumi, H, Ishigami, G, Furutani, K, Michikawa, Y

    EPSC   9   465  2014

  • Multi-purpose Wide-Angle Vision System for Remote Control of Planetary Exploring Rover

    Sota Shimizu, Nobuyuki Hasebe, Kazutaka Nakamura, Hiroki Kusano, Hiroshi Nagaoka, Kyeong Ja Kim, Yi Re Choi, Eung Seok Yi

    IECON 2014 - 40TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY   2014   5260 - 5265  2014

     View Summary

    Wide-Angle Fovea Vision Sensor (WAFVS) system was designed and developed being inspired from advantages of the human eye's functions. This system is characterized by its space-variant data acquisition property, i.e., the WAFVS captures a 120-degree wide-angle input image in which its resolution (or magnification) changes like the human visual acuity. As well-known, the human visual acuity is the highest at its central field of view (FOV) and decreases rapidly towards its peripheral FOV. Thus, using the WAFVS, we can observe a target in detail by its central field of view while observing the whole of environment by its wide field of view. In addition, by controlling a view direction of the WAFVS, this WAFVS system gets visual information from the environment more in detail by smaller data amount. Hence, the WAFVS achieves a better performance of data transmission and data storage. One of severe problems in remote control of rovers, UAVs, and satellites is of a pay-load. In this point of view, the authors think that the WAFVS is suitable for the planetary exploring rover because it was originally developed for multi-purpose use of a single vision sensor. This paper describes the multi-purpose use of the WAFVS system, i.e., the following tasks: (1) observing the environment displayed to the operator for the remote navigation of the rover, (2) recording images of important scenes by changing a view direction of the WAFVS, and (3) monitoring if the instruments on the rover work well or not. Moreover, this paper experiments and discusses on how to display images to the operator when an eye-tracking device is applied as a target coordinate input device. Accuracy index, i.e., a measurement error of a target, is defined in order to evaluate performance of a combination among the vision sensor, the coordinate input device and the image display method.

  • A study on Color Information Corrected in Human Brain -Measurement and Evaluation of Color Propagation-

    Sota Shimizu, Takumi Kadogawa, Masayuki Naito, Takumi Hashizume, Hiroki Kusano, Hiroshi Nagaoka, Nobuyuki Hasebe, Yoshiaki Tanzawa

    IECON 2014 - 40TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY   2014.10   5230 - 5235  2014

     View Summary

    There exists a well-known visual illusion with respect to color propagation. That is, a human subject confuses a color in the subject's peripheral field of view (FOV) as another color in the central FOV (with a shape of circular disk) spreads into the peripheral FOV or as a color in the peripheral FOV erodes another color in the central FOV (also with a shape of circular disk) when he/she keeps gazing at a specific color visual stimulus in his/her central FOV for more than several seconds. In this paper, the authors experiment this illusion using multiple naive subjects in conditions of the visual stimuli as the central or peripheral colors and the disk size change. This paper has proposed a rate of propagation as a criterion and has analyzed and discussed the illusion using it.

  • Development of an X-ray generator using a pyroelectric crystal for X-ray fluorescence analysis on planetary landing missions

    Hiroki Kusano, Yuki Oyama, Masayuki Naito, Hiroshi Nagaoka, Haruyoshi Kuno, Eido Shibamura, Nobuyuki Hasabe, Yoshiharu Amano, Kyeong J. Kim, Jose A. Matias Lopes

    HARD X-RAY, GAMMA-RAY, AND NEUTRON DETECTOR PHYSICS XVI   9213   doi:10.1117/12.2061547, 2014  2014

     View Summary

    The chemical element abundance on planetary surface is essential for planetary science. We have been developing an active X-ray spectrometer (AXS), which is an in-situ chemical element analyzer based on the X-ray fluorescence analysis for future planetary landing missions. The AXS consists of an X-ray detector and multiple X-ray sources. Although a pyroelectric X-ray generator is promising for the AXS as an X-ray source, the raise of emission Xray intensity is necessary for short-time and precise determination of elemental composition. Also, in order to enhance the detection efficiency of light major elements such as Mg, Al, and Si, we have tested the low energy X-ray emission by changing the target material. In this study, the X-ray emission calculation at the target by Monte Carlo simulation and the X-ray emission experiments were carried out. More than 10(6) cps of the time-averaged X-ray emission rate was achieved in maximum using a LiTaO3 crystal with 4 mm thickness and Cu target with 10 mu m thickness. The performance of pyroelectric X-ray generator is presented in this paper.

    DOI

  • Predicted CALET measurements of electron and positron spectra from 3 to 20 GeV using the geomagnetic field

    B.F.Rauch e, l, CALET Collaboration

    Advanced in Space Reasearch   53   1438 - 1443  2013.11  [Refereed]

  • Predicted CALET measurements of ultra-heavy cosmic ray relative abundances

    B.F. Rauch, l, CALET Collaboration

    Advances in Space Research   53   1444 - 1450  2013.10  [Refereed]

  • The Kaguya gamma-ray spectrometer: instrumentation and in-flight performances

    M. Kobayashi, N. Hasebe, T. Miyachi, M. Fujii, E. Shibamura, O. Okudaira, Y. Karouji, M. Hareyama, T. Takashima, S. Kobayashi, C. d'Uston, S. Maurice, N. Yamashita, Robert C. Reedy

    JOURNAL OF INSTRUMENTATION   8 ( 8(2013)04010. )  2013.04

     View Summary

    A Gamma-Ray Spectrometer (GRS) had been developed as a part of the science payload for the first Japanese lunar explorer, Kaguya. The Kaguya was successfully launched from Tanegashima Space Center on September 14, 2007 and was injected into an orbit around the Moon and the mission ended on June 11, 2009. The Kaguya GRS (hereafter KGRS) has a large-volume Ge semiconductor detector of 252 cc as the main detector and bismuth-germanate and plastic scintillators as an active shielding. The Ge detector achieved an energy resolution of 3.0 keV (FWHM) for 1332 keV gamma ray in ground test despite the use of a mechanical cryocooler and observed gamma rays in energies ranging 0.2 to 12MeV in lunar orbit. It was the first use of a Ge detector for lunar exploration. During the mission, KGRS participated in geochemical survey and investigated the elemental compositions of subsurface materials of the Moon. In this paper, we summarize the overview of the KGRS describing the design and in-flight performance of the instrument. This paper provides basic information required for reading science articles regarding the KGRS's observation data.

    DOI

  • Experimental investigation of bubble occurrence and locality distribution of bubble detectors bombarded with high-energy helium ions

    S. L. Guo, T. Doke, D. H. Zhang, L. Li, B. L. Chen, J. Kikuchi, N. Hasebe, K. Terasawa, K. Hara, T. Fuse, N. Yasuda, T. Murakami

    Radiation Measurements   50   31 - 37  2013.03

     View Summary

    Large-sized bubble detectors with microscopic droplets of superheated liquids of dichlorodifluoromethane (Freon-12), dichlorotetrafluoroethane (Freon-114), tetrafluoroethane (Freon-134a), and mixture of Freon-12 and Freon-114, respectively, were irradiated with 150 MeV/amu helium ions at the HIMAC accelerator in NIRS, Chiba, Japan. Distributions of bubbles produced by the helium ions have been studied in each type of the detectors. The origin of the bubbles has been investigated. The detection efficiency of each type of the bubble detectors for helium ions with respect to the energy of the ions has been obtained. The phenomenon of bubble occurrence and its possible applications to the determination of He intensity from accelerators, research of track formation mechanism, energy loss straggling and neutron detection in the space and at higher altitude are discussed. © 2012 Elsevier Ltd. All rights reserved.

    DOI

  • Geochemistry and mineralogy of a feldspathic lunar meteorite (regolith breccia), Northwest Africa 2200

    Hiroshi Nagaoka, Yuzuru Karouji, Tomoko Arai, Mitsuru Ebihara, Nobuyuki Hasebe

    Polar Science   7 ( 3-4 ) 241 - 259  2013

     View Summary

    The lunar meteorite Northwest Africa (NWA) 2200 is a regolith breccia with a ferroan feldspathic bulk composition (Al2O3=30.1wt.%
    Mg#=molar 100×Mg/(Mg+Fe)=59.2) and low Th content (0.42μg/g). Lithologically, NWA 2200 is a diverse mixture of lithic and glassy clasts, mineral fragments, and impact glass spherules, all embedded in a dark glassy matrix. NWA 2200 contains some feldspathic brecciated rock components (ferroan anorthositic granulitic breccia, poikiloblastic granulitic breccia, and glassy melt breccia with an intersertal texture). The bulk compositions of these brecciated components indicate they are derived from ferroan troctolitic or noritic anorthosite lithologies (bulk Al2O3=26-30wt.%
    bulk FeO/MgO&gt
    1.0). The bulk composition of NWA 2200 is more ferroan and feldspathic than the Apollo feldspathic regolith samples and feldspathic lunar regolith meteorites, and is also more depleted in incompatible elements (e.g., rare earth elements) than Apollo 16 feldspathic regolith samples. We conclude that NWA 2200 originated from a location different to the Apollo landing sites, and may have been sourced from the ferroan KREEP-poor highlands, "KREEP" materials are enriched in such elements as potassium (K), rare earth elements (REE), phosphorus (P). © 2013 Elsevier B.V. and NIPR.

    DOI

  • Basic studies on x-ray fluorescence analysis for active x-ray spectrometer on SELENE-2

    Hiroki Kusano, Nobuyuki Hasebe, Hiroshi Nagaoka, Takuro Kodama, Yuki Oyama, Reiko Tanaka, Yoshiharu Amano, Kyeong J. Kim, Jose A. Matias Lopes

    HARD X-RAY, GAMMA-RAY, AND NEUTRON DETECTOR PHYSICS XV   8852  2013

     View Summary

    An active X-ray spectrometer (AXS) is now being developed as a payload candidate for the rover on SELENE-2, the next Japanese lunar exploration mission. The AXS will determine the chemical compositions of lunar rocks and regolith around the landing site. The surface of lunar rock samples will be ground using a rock abrasion tool. Thus, fundamental studies on the X-ray fluorescence analysis for lunar rocks and regolith are required to design and develop the AXS. In this study, we have investigated the X-ray fluorescence analysis in order to evaluate the effects of surface roughness of samples and the angle of incident and emergent X-rays. It was found that the fluorescent X-ray yield for low energy X-rays, i.e. the light elements, decreases at rough surface samples. This effect of surface roughness becomes small for smooth surface samples. It was also found that the fluorescent X-ray yield depends on the incident angle, which is attributed to the fact that the X-ray fluorescence occurs closer to the sample surface at larger incident angles. Since the emergent X-rays are affected by the detection geometry and surface roughness, the incident angle effect also depends on the above conditions.

    DOI

  • Radiation Dose on the Lunar Surface Based on the Definition of Protection Quantity and Operational Quantity

    N. Hasebe, K. Hayatsu, H. Kusano, K.J. Kim

       2013

  • Longitudinal and transverse diffusion of electrons in high-pressure xenon

    H. Kusano, J. A.M. Lopes, M. Miyajima, N. Hasebe

    Journal of Instrumentation   8 ( 1 )  2013.01

     View Summary

    High-pressure xenon is an attractive medium for radiation detection in that the time projection chambers can be constructed by combined measurements of charge and light signals. The electron transport properties are essential information for developing and operating high-pressure xenon detectors. In this paper, our recent experimental results of electron diffusion coefficients in high-pressure xenon are presented. We measured the longitudinal diffusion coefficient of electrons under external applied electric fields in high-pressure xenon, ranging from 0.17 to 5.0 MPa in pressure at room temperature. A significant pressure dependence was found in the density-normalized longitudinal diffusion coefficient for low electric field region. We compared the longitudinal diffusion coefficient with the transverse one at a pressure of 1.0 MPa, and obtained the difference between both the diffusion coefficients. The longitudinal diffusion was found to become smaller than the transverse one when increasing the external electric field. © 2012 IOP Publishing Ltd and Sissa Medialab srl.

    DOI

  • Development of a Pyroelectric X-ray Generator for Active X-ray Spectrometer of SELENE-2

    H. Kusano, Y. Amano, N. Hasebe, K. J. Kim, T. Kodama, H. Kuno, H. Nagaoka, Y. Oyama, E. Shibamura, R. Tanaka

      Proc. of 29th ISTS, 2013-k-18,  2013

  • The South Pole-Aitken basin region, Moon: GIS-based geologic investigation using Kaguya elemental information

    Kyeong Ja Kim, James M. Dohm, Jean-Pierre Williams, Javier Ruiz, Trent M. Hare, Nobuyuki Hasebe, Yuzuru Karouji, Shingo Kobayashi, Makoto Hareyama, Eido Shibamura, Masanori Kobayashi, Claude d'Uston, Olivier Gasnault, Olivier Forni, Sylvestre Maurice

    ADVANCES IN SPACE RESEARCH   50 ( 12 ) 1629 - 1637  2012.12

     View Summary

    Using Geographic Information Systems (GIS), we performed comparative analysis among stratigraphic information and the Kaguya (SELENE) GRS data of the similar to 2500-km-diameter South Pole-Aitken (SPA) basin and its surroundings. Results indicate that the surface rock materials (including ancient crater materials, mare basalts, and possible SPA impact melt) are average to slightly elevated in K and Th with respect to the rest of the Moon. Also, this study demonstrates that K and Th have not significantly changed since the formation of SPA. The elemental signatures of the impact basin of Fe, Ti, Si, o through time include evidence for resurfacing by ejecta materials and late-stage volcanism. The oldest surfaces of SPA are found to be oxygen-depleted during the heavy bombardment period relative to later stages of geologic development, followed by both an increase in silicon and oxygen, possibly due to ejecta sourced from outside of SPA, and subsequent modification due to mare basaltic volcanism, which increased iron and titanium within SPA. The influence of the distinct geologic history of SPA and surroundings on the mineralogic and elemental abundances is evident as shown in our investigation. (c) 2012 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • The global distribution of calcium on the Moon: Implications for high-Ca pyroxene in the eastern mare region

    N. Yamashita, O. Gasnault, O. Forni, C. d'Uston, R. C. Reedy, Y. Karouji, S. Kobayashi, M. Hareyama, H. Nagaoka, N. Hasebee, K. J. Kim

    EARTH AND PLANETARY SCIENCE LETTERS   353   93 - 98  2012.11

     View Summary

    The first unambiguous global distribution of Ca on the Moon has been revealed by the Kaguya Gamma-Ray Spectrometer. The observation of the 3737 key gamma rays from Ca-40 with a high energy resolution Ge detector, corrected for fast neutrons, improved greatly our confidence in these remote sensing data. While the derived Ca abundance generally confirms the mare-highland dichotomy, we found that the eastern mare regions such as Crisium, Nectaris, and Fecunditatis exhibit unexpected high Ca abundances. This may be explained by regional concentrations of high-Ca clinopyroxene. Our Ca map also shows that the lowest CaO abundance found in the returned samples (similar to 8 wt%) may actually be common in Oceanus Procellarum, suggesting the possible sampling bias of Apollo and Luna missions. These observational results on Ca serve as a complementary criterion for better characterization of mare regions on the Moon. (C) 2012 Elsevier B.V. All rights reserved.

    DOI

  • Electron Mobility and Longitudinal Diffusion Coefficient in High-Density Gaseous Xenon

    Hiroki Kusano, Jose A. Matias-Lopes, Mitsuhiro Miyajima, Eido Shibamura, Nobuyuki Hasebe

    JAPANESE JOURNAL OF APPLIED PHYSICS   51 ( 11 ) 116301  2012.11

     View Summary

    Measurements of the mobility and longitudinal diffusion coefficient of electrons under external electric fields were performed in high-density gaseous xenon at room temperature. The xenon density and reduced electric field ranges were from 2.55 x 10(20) to 1.73 x 10(21) cm(-3) and from 0.027 to 0.19 Td, respectively. The electron transport parameters of the density-normalized mobility, density-normalized longitudinal diffusion coefficient, and the ratio of the longitudinal diffusion coefficient to the mobility were found to increase with increasing density for reduced electric fields at around 0.04 Td. This result indicates the density-dependent variation of the effective momentum-transfer cross section for electron-atom scattering. It was also found that the density-dependent variations are different depending on the electron transport parameters, which can be attributed to the difference in parameter sensitivity to the momentum-transfer cross section. (C) 2012 The Japan Society of Applied Physics

    DOI

  • The global distribution of calcium on the Moon: Implications for high-Ca pyroxene in the eastern mare region

    N. Yamashita, O. Gasnault, O. Forni, C. d'Uston, R. C. Reedy, Y. Karouji, S. Kobayashi, M. Hareyama, H. Nagaoka, N. Hasebee, K. J. Kim

    EARTH AND PLANETARY SCIENCE LETTERS   353   93 - 98  2012.11

     View Summary

    The first unambiguous global distribution of Ca on the Moon has been revealed by the Kaguya Gamma-Ray Spectrometer. The observation of the 3737 key gamma rays from Ca-40 with a high energy resolution Ge detector, corrected for fast neutrons, improved greatly our confidence in these remote sensing data. While the derived Ca abundance generally confirms the mare-highland dichotomy, we found that the eastern mare regions such as Crisium, Nectaris, and Fecunditatis exhibit unexpected high Ca abundances. This may be explained by regional concentrations of high-Ca clinopyroxene. Our Ca map also shows that the lowest CaO abundance found in the returned samples (similar to 8 wt%) may actually be common in Oceanus Procellarum, suggesting the possible sampling bias of Apollo and Luna missions. These observational results on Ca serve as a complementary criterion for better characterization of mare regions on the Moon. (C) 2012 Elsevier B.V. All rights reserved.

    DOI

  • Nuclear Planetology: Especially Concerning the Moon and Mars

    Kyeong Ja Kim, Nobuyuki Hasebe

    RESEARCH IN ASTRONOMY AND ASTROPHYSICS   12 ( 10 ) 1313 - 1380  2012.10

     View Summary

    To approach basic scientific questions on the origin and evolution of planetary bodies such as planets, their satellites and asteroids, one needs data on their chemical composition. The measurements of gamma-rays, X-rays and neutrons emitted from their surface materials provide information on abundances of major elements and naturally radioactive gamma-ray emitters. Neutron spectroscopy can provide sensitive maps of hydrogen- and carbon-containing compounds, even if buried, and can uniquely identify layers of carbon-dioxide frost. Nuclear spectroscopy, as a means of compositional analysis, has been applied via orbital and lander spacecraft to extraterrestrial planetary bodies: the Moon, Venus, Mars, Mercury and asteroids. The knowledge of their chemical abundances, especially concerning the Moon and Mars, has greatly increased in recent years. This paper describes the principle of nuclear spectroscopy, nuclear planetary instruments carried on planetary missions so far, and the nature of observational results and findings of the Moon and Mars, recently obtained by nuclear spectroscopy.

  • Nuclear Planetology: Especially Concerning the Moon and Mars

    Kyeong Ja Kim, Nobuyuki Hasebe

    RESEARCH IN ASTRONOMY AND ASTROPHYSICS   12 ( 10 ) 1313 - 1380  2012.10

     View Summary

    To approach basic scientific questions on the origin and evolution of planetary bodies such as planets, their satellites and asteroids, one needs data on their chemical composition. The measurements of gamma-rays, X-rays and neutrons emitted from their surface materials provide information on abundances of major elements and naturally radioactive gamma-ray emitters. Neutron spectroscopy can provide sensitive maps of hydrogen- and carbon-containing compounds, even if buried, and can uniquely identify layers of carbon-dioxide frost. Nuclear spectroscopy, as a means of compositional analysis, has been applied via orbital and lander spacecraft to extraterrestrial planetary bodies: the Moon, Venus, Mars, Mercury and asteroids. The knowledge of their chemical abundances, especially concerning the Moon and Mars, has greatly increased in recent years. This paper describes the principle of nuclear spectroscopy, nuclear planetary instruments carried on planetary missions so far, and the nature of observational results and findings of the Moon and Mars, recently obtained by nuclear spectroscopy.

  • Mass spectrometry analysis of etch products from CR-39 plastic irradiated by heavy ions

    S. Kodaira, D. Nanjo, H. Kawashima, N. Yasuda, T. Konishi, M. Kurano, H. Kitamura, Y. Uchihori, S. Naka, S. Ota, Y. Ideguchi, N. Hasebe, Y. Mori, T. Yamauchi

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS   286   229 - 232  2012.09

     View Summary

    As a feasibility study, gas chromatography-mass spectrometry (GC-MS) and matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) have been applied to analyze etch products of CR-39 plastic (one of the most frequently used solid states nuclear track detector) for the understanding of track formation and etching mechanisms by heavy ion irradiation. The etch products of irradiated CR-39 dissolved in sodium hydroxide solution (NaOH) contain radiation-induced fragments. For the GC-MS analysis, we found peaks of diethylene glycol (DEG) and a small but a definitive peak of ethylene glycol (EG) in the etch products from CR-39 irradiated by 60 MeV N ion beams. The etch products of unitradiated CR-39 showed a clear peak of DEG, but no other significant peaks were found. DEG is known to be released from the CR-39 molecule as a fragment by alkaline hydrolysis reaction of the polymer. We postulate that EG was formed as a result of the breaking of the ether bond (C-O-C) of the DEG part of the CR-39 polymer by the irradiation. The mass distribution of polyallylalcohol was obtained from the etch products from irradiated and unirradiated CR-39 samples by MALDI-MS analysis. Polyallylalcohol, with the repeating mass interval of m/z = 58 Da (dalton) between m/z = 800 and 3500, was expected to be produced from CR-39 by alkaline hydrolysis. We used IAA as a matrix to assist the ionization of organic analyte in MALDI-MS analysis and found that peaks from IAA covered mass spectrum in the lower m/z region making difficult to identify CR-39 fragment peaks which were also be seen in the same region. The mass spectrometry analysis using GC-MS and MALDI-MS will be powerful tools to investigate the radiation-induced polymeric fragments and helping to understand the track formation mechanism in CR-39 by heavy ions. (C) 2011 Elsevier B.V. All rights reserved.

    DOI

  • Scintillation and ionization yields produced by alpha-particles in high-density gaseous xenon

    H. Kusano, T. Ishikawa, J. A. M. Lopes, M. Miyajima, E. Shibamura, N. Hasebe

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   683   40 - 45  2012.08

     View Summary

    The average numbers of scintillation photons and liberated electrons produced by 5.49-MeV alpha-particles were measured in high-density gaseous xenon. The density range is 0.12-1.32 g/cm(3) for scintillation measurements at zero electric field, and 0.12-1.03 g/cm(3) for the scintillation and ionization measurements under various electric fields. The density dependence of scintillation yield at zero electric field was observed. The W-s-value, which is defined as the average energy expended per photon, increases with density and becomes almost constant in the density range above 1.0 g/cm(3). Anti-correlations between average numbers of scintillation photons and liberated electrons were found to vary with density. It was also found that the total number of scintillation photons and liberated electrons decreases with increasing density. Several possible reasons for the variation in scintillation and ionization yields with density are discussed. (C) 2012 Elsevier B.V. All rights reserved.

    DOI

  • Lunar farside Th distribution measured by Kaguya gamma-ray spectrometer

    Shingo Kobayashi, Yuzuru Karouji, Tomokatsu Morota, Hiroshi Takeda, Nobuyuki Hasebe, Makoto Hareyama, Masanori Kobayashi, Eido Shibamura, Naoyuki Yamashita, Claude d'Uston, Olivier Gasnault, Olivier Forni, Robert C. Reedy, Kyeong Ja Kim, Yoshiaki Ishihara

    EARTH AND PLANETARY SCIENCE LETTERS   337   10 - 16  2012.07

     View Summary

    Kaguya gamma-ray spectrometer measured thorium (Th) distribution on the lunar farside with the highest sensitivity among past gamma-ray remote sensing missions. The newly obtained Th map has revealed that two regions near the equator on the farside have the lowest Th abundances. We found that the variation of the Th abundance perfectly correlates with the crustal thickness in the farside and the southern nearside, and it could be a result of the crystallization of the lunar magma ocean. (C) 2012 Elsevier B.V. All rights reserved.

    DOI

  • Density Dependence of the Longitudinal Diffusion Coefficient of Electrons in Xenon

    Hiroki Kusano, Jose A. Matias-Lopes, Mitsuhiro Miyajima, Eido Shibamura, Nobuyuki Hasebe

    JAPANESE JOURNAL OF APPLIED PHYSICS   51 ( 4 ) 048001.1 - 048001.2.  2012.04

     View Summary

    The longitudinal diffusion coefficient of electrons and the ratio of the longitudinal diffusion coefficient to the mobility of electrons were measured for the first time in high-density gaseous xenon in the extensive density range of 4.19 x 10(19)-4.82 x 10(20) cm(-3). The density dependence of the longitudinal diffusion coefficient was observed in the reduced electric field range of 0.025-0.055 Td. (c) 2012 The Japan Society of Applied Physics

    DOI

  • Improvement of charge resolution for high Z/beta particles in CR-39 nuclear track detectors by means of two-step etching technique

    S. Kodaira, S. Naka, N. Yasuda, H. Kawashima, M. Kurano, S. Ota, Y. Ideguchi, N. Hasebe, K. Ogura

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS   274   36 - 41  2012.03

     View Summary

    We verified that the two-step etching method of the combination of pre-etching with PEW (Potassium hydroxide + Ethanol + Water) solution and post-etching with NaOH solution makes drastic improvement of charge resolution for high Z/beta particles (Z: nuclear charge. beta: velocity) in CR-39 nuclear track detectors. Detectors were exposed to several heavy ions from Ne to Kr with the energies of <500 MeV/n at HIMAC (Heavy Ion Medical Accelerator in Chiba). The optimum etching conditions were determined to be a pre-etching of PEW solution with concentration of 60 wt% of ethanol for 40 min and a post-etching of 7N NaOH for 12 h. This resulted in a charge resolution for Kr (Z/beta similar to 60) of 0.18 c.u. (charge units). The Z/beta detection threshold was increased as a function of ethanol concentration in PEW pre-etching solutions. We found that the two-step etching method would be useful technique for the precise charge identification by a single track measurement. The 60 wt% ethanol concentration in PEW would be adequate selection for the purpose of trans-iron nuclei measurement discriminating abundant light nuclei in galactic cosmic rays. (C) 2011 Elsevier B.V. All rights reserved.

    DOI

  • Characteristics of charge amplification in a proportional counter filled with high-pressure xenon

    Hiroki Kusano, Mitsuhiro Miyajima, Nobuyuki Hasebe

    Proceedings of the 26th Workshop on Radiation Detectors and Their Uses     99 - 108  2012  [Refereed]

     View Summary

    The characteristics of charge amplification in high-pressure xenon were studied using a cylindrical proportional counter. The investigated pressure range was from 0.5 to 3.0 MPa, which is higher than previous studies. The charge amplification factor was obtained between 15 and 2.4 × 103 for investigated pressure. The first Townsend ionization coefficient was determined from the measured charge amplification factors. As a result, the ratio of α/N at higher pressures seems to increase for the same reduced electric field, which was observed approximately above 2.0 MPa. Consequently, α/N cannot apparently be represented as a function of reduced electric field only. It was found that a proportional counter is worked at weaker reduced electric field at higher pressures. This fact results in the complexity of electron avalanche processes and the deterioration of the energy resolution The non-uniformity of the anode wire would also be a cause of fluctuation of charge amplification particularly at high pressures. The energy resolution was observed to become worse with increasing pressure, which is attributed to above reasons. Nevertheless, the energy resolution in pure xenon is found to be superior to that in xenon-based gas mixtures at high pressure and several hundreds of the charge amplification factor. Further considerations about the first Townsend ionization coefficient in high-pressure xenon will be made in the future, together with the charge amplification in liquid xenon It may also be interesting to compare the behavior of charge amplification in cylindrical proportional counters at high pressure with parallel plate chambers at low pressure at the same reduced electric field. That will be important for better understanding of the mechanism of charge amplification in cylindrical geometry, or non-uniform electric field conditions.

  • Detection threshold control of CR-39 plastic nuclear track detectors for the selective measurement of high LET secondary charged particles

    S. Kodaira, N. Yasuda, H. Kawashima, M. Kurano, S. Naka, S. Ota, Y. Ideguchi, N. Hasebe, K. Ogura

    RADIATION MEASUREMENTS   46 ( 12 ) 1782 - 1785  2011.12

     View Summary

    The two-step etching method using PEW (Potassium hydroxide + Ethanol + Water) and NaOH solutions was applied to the control of the response of CR-39 plastic nuclear track detectors for the measurement of high LET (linear energy transfer) particles. CR-39 detectors were exposed to several heavy ion beams covering the LET infinity H2O range of 30-750 key/mu m from HIMAC (Heavy Ion Medical Accelerator in Chiba) at NIRS (National Institute of Radiological Sciences), Japan. The detectors were pre-etched in PEW solutions with 3 different ethanol concentrations at the temperature of 70 degrees C for 30-60 min. Then, the detectors were post-etched in 7N NaOH solution at the same temperature for 4-28 h. We found that the response curves and the detection thresholds of the detectors smoothly shifted to higher LET regions as the ethanol concentration increases in PEW solution. (C) 2011 Elsevier Ltd. All rights reserved.

    DOI

  • Multimodal characteristics of a piezoelectric lead zirconate titanate element impacted with iron particles having velocities above 20 km/s

    Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Osamu Okudaira, Seiji Takechi, Toshiyuki Onishi, Shigeyuki Minami, Masanori Kobayashi, Takeo Iwai, Eberhard Gruen, Ralf Srama, Nagaya Okada

    ADVANCES IN SPACE RESEARCH   48 ( 3 ) 570 - 577  2011.08

     View Summary

    The responses of a piezoelectric lead zirconate titanate (PZT) element to hypervelocity collisions were experimentally studied. In this study, the particles of masses ranging from 0.3 to 10 fg were made to collide with PZT at velocities between 20 and 96 km/s. The amplitude and the corresponding rise time of the single-pulse output signals that were produced in the piezoelectric PZT element were measured to determine the possible collision states. The results revealed an apparently multimodal output; three classes were assumed to be involved in the pulse formation mechanism. The amplitude and rise time were sensitive to the collision velocity. The multimodal behavior implied that the PZT-based cosmic dust detectors should be calibrated according to the class they belong to. (C) 2011 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • Charge resolution of CR-39 plastic nuclear track detectors for intermediate energy heavy ions

    S. Ota, N. Yasuda, L. Sihver, S. Kodaira, M. Kurano, S. Naka, Y. Ideguchi, E. R. Benton, N. Hasebe

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS   269 ( 12 ) 1382 - 1388  2011.06

     View Summary

    The charge resolution (delta Z) for heavy ions (nuclear charge: Z < 40) of 0.1-1 GeV/n energy in CR-39 plastic nuclear track detector (PNTD) and its dependence on etching time, and on projectile Z and energy were investigated and optimized as part of an effort to make precise measurements of projectile charge-changing cross sections. Two types of CR-39 PNTD, HARZLAS TD-1 and BARYOTRAK, were exposed to heavy ion beams with seven values of Z behind thick targets to produce projectile fragments. Following chemical etching (7 N NaOH at 70 degrees C) for varying etch times, delta Z of the projectiles was determined for each detector type. A strong dependence of delta Z on the amount of bulk etch (B) was seen. It was also observed that delta Z can be remarkably improved with longer etching time as a function of B(-1/2), in accordance with the trend seen in other types of track detector such as glass nuclear track detector. However, for B >= 60 mu m (30 h etching), saturation occurs and there is no further improvement in delta Z. Analysis of the correlations between projectile Z, energy, detector response, and fluctuation of the response make it possible to develop a model to predict the delta Z for projectiles of given Z and energy. The predicted and measured values of delta Z show good agreement within 10%. We conclude that 4 <= Z <= 30 at intermediate energy can be identified with good delta Z in these detectors. The predictive model will be used in designing future cross section measurement experiments. (C) 2011 Elsevier B.V. All rights reserved.

    DOI

  • Acceleration and losses of energetic protons and electrons during magnetic storm on August 30-31, 2004

    L. L. Lazutin, M. I. Panasyuk, N. Hasebe

    Cosmic Research   49 ( 1 ) 35 - 41  2011.03  [Refereed]

     View Summary

    Variations of particle fluxes during a moderate magnetic storm on August 30-31, 2004 are analyzed in this paper using measurements on low-orbit polar satellites CORONAS-F and SERVIS-1. The Earth's radiation belts were filled at this time by enhanced flux of energetic particles accelerated a month ago during magnetic storms on July 23-27. The analysis has shown that even during a moderate magnetic storm a set of several adiabatic and non-adiabatic processes is observed, which leads to acceleration or release of particles and acts selectively depending on the energy range and charge of particles. © 2011 Pleiades Publishing, Ltd.

    DOI

  • The science objectives for CALET

    K. Yoshida, O. Adriani, K.Asano, M.G. Bagliesi, G. Bigongiari, W.R. Binns, M.Bongi, J.Buckley, G. Castellini, M.L. Cherry, G. Collazuol, K. Ebisawa, V. Di Felice, H. Fuke, A.Gherardi, T.G. Guzik, T. Hams, N. Hasebe, M. Hareyama, K. Hibino, M. Ichimura, J. B. Isbert, E. Kamioka, K. Kasahara, Y. Katayose, J. Kataoka, R.Kataoka, N. Kawanaka, M.Y. Kim, H. Kitamura, Y. Komori, T. Kotani, H.S. Krawczynski, J.F. Krizmanic, A. Kubota, S. Kuramata, T.Lomtadze, P. Maestro, L. Marcelli, P. S. Marrocchesi, V. Millucci, J.W. Mitchell, K. Mizutani, A.A. Moiseev, K.Mori, M. Mori, N.Mori, F. Morsani, K. Munakata, H. Murakami, Y.E.Nakagawa, J. Nishimura, S. Okuno, J.F. Ormes, S. Ozawa, P. Papini, B.Rauch, S.Ricciarini, Y. Saito, M. Sasaki, M. Shibata, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J.P. Wefel, K.Yamaoka, A. Yoshida, T. Yuda

    Proc. Intl. Cosmic Ray Conf., Beijing, OG1.5, 0615 (2011)   OG1.5 ( 0615 )  2011

  • Overview of the CALET mission to the ISS

    Shoji Torii

    Proceedings of the 32nd International Cosmic Ray Conference, ICRC 2011   6 ( 0766 ) 351 - 354  2011

     View Summary

    The CALorimetric Electron Telescope (CALET) mission is being developed as a standard payload for the Exposure Facility of the Japanese Experiment Module (JEM/EF) on the International Space Station (ISS). The instrument consists of a segmented plastic scintillator charge measuring module, an imaging calorimeter consisting of 8 scintillating fiber planes with a total of 3 radiation lengths of tungsten plates interleaved with the fiber planes, and a total absorption calorimeter consisting of crossed PWO logs with a total depth of 27 radiation lengths. The major scientific objectives for CALET are to search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electron spectrum (1 GeV - 20 TeV) and observing gamma rays (10 GeV - 10 TeV). CALET has a unique capability to observe electrons and gamma rays in the TeV region since the hadron rejection power is larger than 105 and the energy resolution better than ∼2 % above 100 GeV. CALET has also the capability to measure cosmic ray H, He and heavy nuclei up to 1000 TeV. The instrument will also monitor solar activity and search for gamma ray transients. The phase B study has started, aimed at a launch in 2013 by H-II Transfer Vehicle (HTV) for a 5 year observation period on JEM/EF.

    DOI

  • Neutron production in the lunar subsurface from alpha particles in galactic cosmic rays

    Shuya Ota, Shingo Kobayashi, Lembit Sihver, Naoyuki Yamashita, Nobuyuki Hasebe

    EARTH PLANETS AND SPACE   63 ( 1 ) 25 - 35  2011

     View Summary

    The neutron production from alpha particles in galactic cosmic rays (GCR) in the lunar subsurface has not been estimated with reliable precision despite its importance for lunar nuclear spectroscopy and space dosimetry. Here, we report our estimation of neutron production from GCR nuclei (protons and alpha particles) with the Particle and Heavy Ion Transport code System (PHITS), which includes several heavy ion interaction models. PHITS simulations of the equilibrium neutron density profiles in the lunar subsurface are compared with experimental data obtained in the Apollo 17 Lunar Neutron Probe Experiment. Our calculations successfully reproduced the data within an experimental error of 15%. Our estimation of neutron production from GCR nuclei, estimated by scaling that from protons by a factor of 1.27, is in good agreement within an error of 1% with the calculations using two different alpha particle interaction models in PHITS during a period of average activity of the solar cycle. However, we show that the factor depends on the incident GCR spectrum model used in the simulation. Therefore, we conclude that the use of heavy ion interaction models is important for estimating neutron production in the lunar subsurface.

    DOI

  • Neutron production in the lunar subsurface from alpha particles in galactic cosmic rays

    Shuya Ota, Shingo Kobayashi, Lembit Sihver, Naoyuki Yamashita, Nobuyuki Hasebe

    EARTH PLANETS AND SPACE   63 ( 1 ) 25 - 35  2011

     View Summary

    The neutron production from alpha particles in galactic cosmic rays (GCR) in the lunar subsurface has not been estimated with reliable precision despite its importance for lunar nuclear spectroscopy and space dosimetry. Here, we report our estimation of neutron production from GCR nuclei (protons and alpha particles) with the Particle and Heavy Ion Transport code System (PHITS), which includes several heavy ion interaction models. PHITS simulations of the equilibrium neutron density profiles in the lunar subsurface are compared with experimental data obtained in the Apollo 17 Lunar Neutron Probe Experiment. Our calculations successfully reproduced the data within an experimental error of 15%. Our estimation of neutron production from GCR nuclei, estimated by scaling that from protons by a factor of 1.27, is in good agreement within an error of 1% with the calculations using two different alpha particle interaction models in PHITS during a period of average activity of the solar cycle. However, we show that the factor depends on the incident GCR spectrum model used in the simulation. Therefore, we conclude that the use of heavy ion interaction models is important for estimating neutron production in the lunar subsurface.

    DOI

  • Neutron production in the lunar subsurface from alpha particles in galactic cosmic rays

    Shuya Ota, Shingo Kobayashi, Lembit Sihver, Naoyuki Yamashita, Nobuyuki Hasebe

    EARTH PLANETS AND SPACE   63 ( 1 ) 25 - 35  2011

     View Summary

    The neutron production from alpha particles in galactic cosmic rays (GCR) in the lunar subsurface has not been estimated with reliable precision despite its importance for lunar nuclear spectroscopy and space dosimetry. Here, we report our estimation of neutron production from GCR nuclei (protons and alpha particles) with the Particle and Heavy Ion Transport code System (PHITS), which includes several heavy ion interaction models. PHITS simulations of the equilibrium neutron density profiles in the lunar subsurface are compared with experimental data obtained in the Apollo 17 Lunar Neutron Probe Experiment. Our calculations successfully reproduced the data within an experimental error of 15%. Our estimation of neutron production from GCR nuclei, estimated by scaling that from protons by a factor of 1.27, is in good agreement within an error of 1% with the calculations using two different alpha particle interaction models in PHITS during a period of average activity of the solar cycle. However, we show that the factor depends on the incident GCR spectrum model used in the simulation. Therefore, we conclude that the use of heavy ion interaction models is important for estimating neutron production in the lunar subsurface.

    DOI

  • Improvement of charge resolution for trans-iron nuclei (Z≥30) in CR-39 plastic nuclear track detectors using trajectory tracing technique

    S. Ota, N. Yasuda, L. Sihver, S. Kodaira, S. Naka, Y. Ideguchi, N. Hasebe

    Astrophysics and Space Sciences Transactions   7 ( 4 ) 495 - 500  2011

     View Summary

    Charge identification of trans-iron nuclei (nuclear charge: Z≥ 30) using CR-39 plastic nuclear track detector (PNTD) is essential as a part of an effort to our future measurements of the projectile charge changing cross sections for galactic cosmic ray nuclei, but extremely hard. Therefore, an improvement method of the charge resolution (δZ) for 350 MeV/n Ge in CR-39 PNTD using the trajectory tracing technique with averaging the signals of nuclear tracks for each ion was studied. Eight sheets of CR-39 PNTDs were aligned and exposed to Ge beam behind a graphite target to produce projectile fragments. Average of the nuclear track data was taken over 16 detector surfaces for each ion, then the δZ of Ge was successfully improved from 0.31 charge unit on single surface to 0.15 charge unit in rms, which is good enough for making the precise cross section measurements and no other experiments using CR-39 PNTDs or the other passive detectors have achieved such a good δZ for the trans-iron nuclei with ≥Z 50 (β: relativistic velocity). This method will be very important for our future cross section measurements toward the study of galactic cosmic ray origin. © 2011 Author(s).

    DOI

  • Determining the Absolute Abundances of Natural Radioactive Elements on the Lunar Surface by the Kaguya Gamma-ray Spectrometer

    S. Kobayashi, N. Hasebe, E. Shibamura, O. Okudaira, M. Kobayashi, N. Yamashita, Y. Karouji, M. Hareyama, K. Hayatsu, C. d'Uston, S. Maurice, O. Gasnault, O. Forni, B. Diez, R. C. Reedy, K. J. Kim

    SPACE SCIENCE REVIEWS   154 ( 1-4 ) 193 - 218  2010.07

     View Summary

    The Kaguya gamma-ray spectrometer (KGRS) has great potential to precisely determine the absolute abundances of natural radioactive elements K, Th and U on the lunar surface because of its excellent spectroscopic performance. In order to achieve the best performance of the KGRS, it is important to know the spatial response function (SRF) that describes the directional sensitivity of the KGRS. The SRF is derived by a series of Monte Carlo simulations of gamma-ray transport in the sensor of the KGRS using the full-fledged simulation model of the KGRS, and is studied in detail. In this paper, the method for deriving absolute abundance of natural radioactive elements based on the SRF is described for the analysis of KGRS data, which is also applicable to any gamma-ray remote sensings. In the preliminary analysis of KGRS data, we determined the absolute abundances of K and Th on the lunar surface without using any previous knowledge of chemical information gained from Apollo samples, lunar meteorites and/or previous lunar remote sensings. The results are compared with the previous measurements and the difference and the correspondence are discussed. Future detailed analysis of KGRS data will provide new and more precise maps of K, Th and U on the lunar surface.

    DOI

  • Response of Lead Zirconate Titanate without Poling to High-Energy Heavy-Ion Beam

    Seiji Takechi, Shin-ya Morinaga, Atsuma Kurozumi, Takefumi Uno, Takashi Miyachi, Osamu Okudaira, Masayuki Fujii, Nobuyuki Hasebe, Hiromi Shibata, Takeshi Murakami, Yukio Uchihori, Nagaya Okada

    JAPANESE JOURNAL OF APPLIED PHYSICS   49 ( 6 ) 680021 - 680022  2010.06

     View Summary

    A radiation detector based on the piezoelectric effect, which is fabricated using lead zirconate titanate (PZT), has been investigated by irradiating it with a 400 MeV/n xenon (Xe) beam. To estimate quantitatively the electric charge appearing on the PZT detector, the detector made of PZT without poling was used in this study. It was found that the sensitivity of the detector without poling was reduced by similar to 1/20 compared with that of the detector with poling within the limits of the experimental conditions. (C) 2010 The Japan Society of Applied Physics

    DOI

  • Uranium on the Moon: Global distribution and U/Th ratio

    N. Yamashita, N. Hasebe, R. C. Reedy, S. Kobayashi, Y. Karouji, M. Hareyama, E. Shibamura, M. -N. Kobayashi, O. Okudaira, C. d'Uston, O. Gasnault, O. Forni, K. J. Kim

    GEOPHYSICAL RESEARCH LETTERS   37  2010.05  [Refereed]

     View Summary

    The Kaguya Gamma-Ray Spectrometer uniquely identified uranium gamma-ray lines from the Moon with a superior energy resolution of similar to 1%. A global lunar map of uranium distribution is derived for the first time. It was found that uranium abundances vary up to 2 ppm with an average of similar to 0.3 ppm, while the average thorium abundance was similar to 1.2 ppm. From these analyses, significant variation in U/Th ratio was found in the farside of the Moon that had not been reported by previous observations or in lunar materials. Our observations suggest that the lunar highland is not as uniform as has been long considered. Citation: Yamashita, N., et al. (2010), Uraniumon theMoon: Global distribution and U/Th ratio, Geophys. Res. Lett., 37, L10201, doi:10.1029/2010GL043061.

    DOI

  • Study of the characteristics of a piezoelectric lead zirconate titanate radiation detector using a pulsed xenon source

    Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Osamu Okudaira, Seiji Takechi, Atsuma Kurozumi, Shinya Morinaga, Takefumi Uno, Hiromi Shibata, Masanori Kobayashi, Takeshi Murakami, Yukio Uchihori, Nagaya Okada

    JOURNAL OF APPLIED PHYSICS   107 ( 10 ) 104902  2010.05

     View Summary

    The detector characteristics of piezoelectric lead zirconate titanate (PZT) were studied by directly irradiating a multilayered PZT detector with 400 MeV/n xenon ions. An extracted beam was processed with a rotating slit. Thus, passed through similar to 10(3) xenon ions were available for 50 to 250 mu s. The effect of polarization on the output signal was discussed, and the optimal electrode configuration was determined. The output signal appeared as an isolated pulse whose amplitude was qualitatively understood by the Bethe-Bloch formula. However, the calculated and the observed values differed depending on the rotation speed of the slit. A process that can explain the differences is presented here. The output signal appearing beyond the range of 400 MeV/n xenon ion beam was discussed. The sensitivity was compared with that obtained with hypervelocity collision of dust. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3373383]

    DOI

  • Interaction of piezoelectric lead zirconate titanate with 400 MeV/n xenon beam

    Seiji Takechi, Shin-ya Morinaga, Atsuma Kurozumi, Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Hiromi Shibata, Takeshi Murakami, Yukio Uchihori, Nagaya Okada

    RADIATION PHYSICS AND CHEMISTRY   79 ( 5 ) 603 - 605  2010.05

     View Summary

    The characteristics of radiation detector fabricated by stacking some piezoelectric lead zirconate titanate (PZT) elements were studied by irradiating it with a 400 MeV/n xenon (Xe) beam. Comparing between observed results from the detector and calculation results using Bethe-Bloch formula, it was found that the amplitude of the output voltage observed was dependent on the amount of ionization energy loss of Xe ion with PZT. (C) 2010 Elsevier Ltd. All rights reserved.

    DOI

  • Dynamics of solar protons in the earth's magnetosphere during magnetic storms in November 2004-January 2005

    L. L. Lazutin, Yu.V. Gotselyuk, E. A. Murav'eva, I. N. Myagkova, M. I. Panasyuk, L. I. Starostin, B.Yu. Yushkov, K. Kudela, N. Hasebe, K. Sukurai, M. Hareyama

    Geomagnetism and Aeronomy   50 ( 2 ) 168 - 180  2010.04  [Refereed]

     View Summary

    The processes of penetration, trapping, and acceleration of solar protons in the Earth's magneto-sphere during magnetic storms in November 2004 and January 2005 are studied based on the energetic particle measurements on the CORONAS-F and SERVIS-1 satellites. Acceleration of protons by 1-2 orders of magnitude was observed after trapping of solar protons with an energy of 1-15 MeV during the recovery phase of the magnetic storm of November 7-8, 2004. This acceleration was accompanied by an earthward shift of the particle flux maximum for several days, during which the series of magnetic storms continued. The process of relativistic electron acceleration proceeded simultaneously and according to a similar scenario including acceleration of protons. At the end of this period, the intensification was terminated by the process of precipitation, and a new proton belt split with the formation of two maximums at L ~ 2 and 3. In the January 2005 series of moderate storms, solar protons were trapped at L = 3. 7 during the storm of January 17-18. However, during the magnetic storm of January 21, these particles fell in the zone of quasi-trapping, or precipitated into the atmosphere, or died in the magnetosheath. At the same time, the belts that were formed in November at L ~ 2 and 3 remained unchanged. Transformations of the proton (and electron) belts during strong magnetic storms change the intensity and structure of belts for a long time. Thus, the consequences of changes during the July 2004 storm did not disappear until November disturbances. © Pleiades Publishing, Ltd., 2010.

    DOI

  • NEUTRON PRODUCTION IN THE LUNAR SUBSURFACE FROM GALACTIC COSMIC RAY NUCLEI

    Shuya Ota, Lembit Sihver, Shingo Kobayashi, Naoyuki Yamashita, Nobuyuki Hasebe

    ASTROPARTICLE, PARTICLE AND SPACE PHYSICS, DETECTORS AND MEDICAL PHYSICS APPLICATIONS   5   719 - 723  2010  [Refereed]

     View Summary

    The neutron production from galactic cosmic ray (GCR) protons and alpha particles in the lunar subsurface was estimated using the three-dimensional Monte Carlo simulation code PHITS, together with GCR input spectra based on the BESS measurements. The PHITS simulations of equilibrium neutron density profiles in the lunar subsurface were compared with experimental data by Apollo 17 Lunar Neutron Probe Experiment. By use of accurate spectra and nuclear interaction models, our calculations successfully reproduced the data within the experimental error at the shallower region than 300 g/cm(2). However, our calculation was up to 30% higher in the deeper region.

  • Lunar gamma-ray observation by kaguya GRS

    N. Hasebe, N. Yamashita, Y. Karouji, S. Kobayashi, M. Hareyama, S. Komatsu, K. Hayatsu, K. Nemoto, K. Iwabuchi, Y. Takeda, H. Nagaoka, K. Tsukada, J. Machida, O. Okudaira, S. Sakurai, E. Shibamura, M. N. Kobayashi, M. Ebihara, T. Hihara, T. Arai, T. Sugihara, H. Takeda, C. D'Uston, O. Gasnault, B. Diez, O. Forni, S. Maurice, R. C. Reedy, K. J. Kim

    Advances in Geosciences: Volume 19: Planetary Science (PS)   19   57 - 68  2010.01  [Refereed]

     View Summary

    The high precision Gamma-Ray Spectrometer (GRS) was carried on the first Japan's large-scale lunar orbiter, SELENE (KAGUYA). The GRS employed a Ge detector with high energy resolution. Since the regular observation by the KAGUYA GRS started on December 14, 2007, gamma-ray data had been accumulated over the Moon. Many elements were identified: O, Mg, Al, Si, K, Ca, Ti, Fe, Th and U. The regular GRS observation at 100 km altitude let us create global distribution maps of chemical abundances on the lunar surface, which showed considerable regional variations. Special operations were conducted in December 2008 in order to measure background gamma rays from materials of the spacecraft body and the GRS detector itself, and to anneal the Ge crystal for about two days at 85 ± 5 degrees Celsius in order to recover the resolution of the Ge crystal that had been degraded due to radiation damage in space. Its energy resolution was improved to the level at the initial phase of the mission. Results from the special operations and regular observation of the Moon are described.

    DOI

  • High Performance Germanium Gamma-Ray Spectrometer on Lunar Polar Orbiter SELENE (KAGUYA)

    Hasebe, N, Shibamura, E, Miyachi, T, Takashima, T, Kobayashi, M, Okudaira, O, Yamashita, N, Kobayashi, S, Karouji, Y, Hareyama, M, Kodaira, S, Hayatsu, K, Iwabuchi, K, Nemoto, S, Sakurai, K, Komatsu, S, Miyajima, M, Ebihara, M, Hihara, T, Arai, T, Sugihara, T, Takeda, H, D'Uston, C, Gasnault, O, Diez, B, Forni, O, Maurice, S, Reedy, R. C

    Transactions of Space Technology Japan   7(2010) ( 35 )  2010

  • Calorimetric Electron Telescope (CALET) to observe cosmic-ray electrons and gamma-rays on the International Space Station

    T.Tamura, S.Torii et, al, CALET Collaboration

    Nucl. Instr. & Meth. Phys. Res.   A 623(1)(210)   428 - 430  2010

  • Uranium on the Moon: The Distribution and U/Th Ratio Observed by Kaguya Gamma-Ray Spectrometer

    N. Yamashita, N. Hasebe, E. Shibamura, M. –N. Kobayashi, O. Okudaira, Y. Karouji, M. Hareyama, S. Kobayashi, C. d’Uston, O. Gasnault, O. Forni, B. Diez, R. C. Reedy

    Geophys. Res. Letters, 37   L10201, 5 PP : doi:10.1029/201  2010

  • Neutron Production in the Lunar Subsurface from Galactic Cosmic Rays

    Shuya Ota, Lembit Sihver, Shingo Kobayashi, Nobuyuki Hasebe

    2010 IEEE AEROSPACE CONFERENCE PROCEEDINGS     1 - 8  2010

     View Summary

    The neutron production from galactic cosmic ray (GCR) protons and alpha particles in the lunar subsurface was estimated using the three-dimensional Monte Carlo simulation code PHITS. The PHITS simulations of equilibrium neutron density profiles in the lunar subsurface were compared with experimental data by the Apollo 17 Lunar Neutron Probe Experiment. By use of the latest GCR spectra based on BESS measurements and well benchmarked nuclear interaction models, our calculations well reproduced the data within the experimental error of 15% (measurement) + 30% (systematic) at the region shallower than 300 g/cm(2). However, our calculation showed 10-20% higher values in the deeper region.(1 2)

  • Intensity and time profile of recombination luminescence produced by an alpha-particle in dense xenon gas

    M. Mimura, S. Kobayashi, T. Ishikawa, M. Miyajima, N. Hasebe

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   613 ( 1 ) 106 - 111  2010.01

     View Summary

    The time profile of recombination luminescence of dense xenon gas irradiated by an alpha-particle was absolutely measured in the density range of 0.027-0.112 g/cm(3) with the aim to investigate the intensities of recombination luminescence at zero electric field. It was found that the number of scintillation photons due to the recombination luminescence increases with xenon density up to around 0.05 g/cm(3), and then becomes nearly constant (= 2.32 x 10(5) photons for an alpha-particle with 5.49 MeV). The probability of recombination between electrons and ions at zero electric field is about 88% in the density range of 0.05-0.112 g/cm(3). it was also found that the percentage of slow component (similar to sub-milliseconds) in the recombination luminescence decreases with density from 73% to 33% in the density range from 0.027 to 0.112 g/cm(3). (C) 2009 Elsevier B.V. All rights reserved.

    DOI

  • Global Distributions of K, Th and U on the Moon Observed by Kaguya GRS

    N. Hasebe, Y. Karouji, O. Okudaira, K. Hayatsu, Y. Takeda, H. Nagaoka, K.Tsukada, J. Machida, S. Sakurai, S. Komatsu, S. Kobayashi, M. Hareyama, T. Okada, E. Shibamura, M.-N. Kobayashi, N. Yamashita, C. d’Uston, O. Gasnault, O. Forni, S. Maurice, K. Kim, R. C. Reedy, J. M. Dohm

    New Advances in Lunar Exploration (Proc. of International Symposium on Lunar Science ISLS2010, March 25-26, Macau   2010, March 25-26   42 - 49  2010

  • Geochemistry and Mineralogy of Ferroan Feldspathic Lunar Meteorite Northwest Africa 2200

    H. Nagaoka, Y. Karouji, N. Hasebe, T. Arai, M. Ebihara

    New Advances in Lunar Exploration (Proc. of International Symposium on Lunar Science ISLS2010, March 25-26, Macau   2010, March 25-26   140 - 148  2010

  • Distributions of K, Th, U and Rare Earth Metal in Procellarum KREEP Terrane

    N. Hasebe, Y. Karouji, O. Okudaira, H. Nagaoka, K. Tsukada, S. Kobayashi, K. Kim, J. M. Dohm

    New Advances in Lunar Exploration (Proc. of International Symposium on Lunar Science ISLS2010, March 25-26, Macau   2010, March 25-26   84 - 89  2010

  • Distributions of K and Th on the moon: The initial results from observations by selene GRS

    Yuzuru Karouji, Nobuyuki Hasebe, Osamu Okudaira, Naoyuki Yamashita, Shingo Kobayashi, Makoto Hareyama, Takashi Miyachi, Kodaira Satoshi, Kazuya Iwabuchi, Kanako Hayatsu, Shinpei Nemoto, Yuko Takeda, Koichi Tsukada, Hiroshi Nagaoka, Masanori Kobayasi, Eido Shibamura, Mitsuru Ebihara, Takeshi Hihara, Tomoko Arai, Takamitsu Sugihara, Hiroshi Takeda, Claude D’Uston, Sylvestre Maurice, Olivier Gasnault, Olivier Forni, Benedicte Diez, Robert C. Reedy, Kyeong J. Kim, Takeshi Takashima, Yuichi Iijima, Hisashi Otake

    Advances in Geosciences: Volume 19: Planetary Science (PS)   (2009) in press   43 - 56  2010.01

     View Summary

    The high precision gamma-ray spectrometer (GRS) onboard the Japanese lunar explorer, SELENE (KAGUYA) consists of a large Ge crystal as the main detector and massive BGO and plastic scintillators as anticoincidence detectors. After a series of initial health checks, it started regular observation officially on December 21, 2007. Energy spectra of lunar gamma rays were obtained by GRS with very good energy resolution being 0.6% at 1.46MeV over the lunar surface. Many peaks of gamma rays from major elements and natural radioactive elements in the lunar surface have been observed. Individual gamma-ray lines emitted from the lunar surface have been identified. Here, we report the initial results obtained practically during the period from December 14, 2007 to February 17, 2008. Global maps of K and Th gamma-ray intensities are reported using count rates in several energy bands.

    DOI

  • Chemistry and Mineralogy of Ferroan feldspathic lunar meteorite Northwest Africa 2200

    H. Nagaoka, Y. Karouji, N. Hasebe, T. Arai, M. Ebihara

    New Advance in Lunar Exploration     140 - 148  2010

  • Behaviour of piezoelectric lead zirconate titanate irradiating with high-energy xenon ions

    Seiji Takechi, Shin-ya Morinaga, Atsuma Kurozumi, Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Hiromi Shibata, Takeshi Murakami, Yukio Uchihori, Nagaya Okada

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   609 ( 2-3 ) 272 - 275  2009.10  [Refereed]

     View Summary

    The characteristics of a detector fabricated using piezoelectric lead zirconate titanate (PZT) were studied by irradiating it with a 400 MeV/n xenon (Xe) beam while changing the beam flux intensity. The largest output signal was observed from the detector when the beam power per unit time was estimated to be largest. It was also found that the sensitivity per Xe ion of the detector seemed to be higher with decreasing the amount of the Xe ion flux within the limits of the experimental conditions. (C) 2009 Elsevier B.V. All rights reserved.

    DOI

  • Dependence of Thickness of Lead Zirconate Titanate Material Used as Radiation Detector

    Takechi Seiji, Morinaga Shin-ya, Kurozumi Atsuma, Miyachi Takashi, Fujii Masayuki, Hasebe Nobuyuki, Shibata Hiromi, Murakami Takeshi, Uchihori Yukio, Okada Nagaya

    JAPANESE JOURNAL OF APPLIED PHYSICS   48 ( 10 )  2009.10  [Refereed]

    DOI

  • Control of the detection threshold of CR-39 PNTD for measuring ultra heavy nuclei in galactic cosmic rays

    S. Kodaira, N. Yasuda, H. Kawashima, M. Kurano, N. Hasebe, T. Doke, S. Ota, K. Ogura

    RADIATION MEASUREMENTS   44 ( 9-10 ) 861 - 864  2009.10

     View Summary

    It is necessary to develop a track detector with higher detection threshold and high charge resolution for ultra heavy cosmic ray observation. The track registration sensitivity in CR-39 track detector etched by PEW (Potassium-Ethanol-Water) solution was verified using heavy ion beams at the HIMAC accelerator. It was found that PEW solution makes effectively to desensitize the track registration sensitivity in CR-39 detector. Its detection threshold of Z*/beta is successfully raised to be Z*/beta = 39 by using PEW solution with the concentration of ethanol of 45 wt%. However this produces a "fuzzy track". A two-step process of etching involving a post-etch with 7 mol/l sodium hydroxide solution produced very clear track edges and remarkably improves the charge resolution for heavy ions. (C) 2009 Elsevier Ltd. All rights reserved.

    DOI

  • Characteristics of the copolymerized CR-39/DAP track detector for the observation of ultra heavy nuclei in galactic cosmic rays

    S. Kodaira, N. Yasuda, H. Kawashima, M. Kurano, N. Hasebe, T. Doke, S. Ota, T. Tsuruta, H. Hasegawa, S. Sakai, T. Nishi, K. Ogura

    RADIATION MEASUREMENTS   44 ( 9-10 ) 775 - 778  2009.10

     View Summary

    A new copolymer of CR-39 and DAP resin was developed for the selective detection of ultra heavy nuclei in galactic cosmic rays. The track registration sensitivity for heavy ions with various Z(+)/beta was verified for copolymers mixing CR-39 (BARYOTRAK) with various concentrations of DAP using heavy ion beams at the HIMAC accelerator. In order to realize sufficient polymerization of CR-39/DAP copolymer, the optimum fabricating method was also verified by modifying the concentration of the initiator and temperature-time curing cycle for the copolymerization. CR-39 (BARYOTRAK) used for the base material of copolymerization has many advantages: 1) high uniformity of detector response, 2) extremely clear surface condition after etching, and 3) excellent charge and mass resolutions for heavy ions. The surface condition of the copolymer after etching is remarkably improved by using the BARYOTRAK monomer and its track registration sensitivity is controllable by changing the DAP concentration. However the detection threshold of the CR-39 (BARYOTRAK)/DAP copolymer is not yet satisfactory. (C) 2009 Elsevier Ltd. All rights reserved.

    DOI

  • A future plan in observing ultra-heavy nuclei (Z=30-110) of cosmic rays with large-scale collector at the lunar base

    N. Hasebe, S. Kodaira, M. Hareyama, N. Yasuda

    RADIATION MEASUREMENTS   44 ( 9-10 ) 913 - 916  2009.10

     View Summary

    Lunar-based measurement of galactic cosmic ray (GCR) nuclei with a high precision is a challenging approach in cosmic ray research for the coming 20 years. This approach focuses to measure the elemental composition of Pt- and Pb-groups, actinide and possibly trans-uranic nuclei of Pu and Cm. The observation covers a wide range of scientific themes including the study on the origin of GCR nuclei, the characteristic time, heating and acceleration mechanism of GCR particles. A large-scaled particle telescope is required in order to measure those nuclides with high precision. Solid state nuclear track detectors (SSTDs) with a geometric factor of about 1000 m(2)sr allow us to measure them easily. Fluorescent nuclear track detector such as Al(2)O(3) doped with C and Mg is the best candidate at present among SSTDs for a lunar-based experiment which is currently the focus of an international program of scientific investigation. A permanent sunshine region near crater at lunar polar region is thought to be an excellent site. A two-year-exposure by the large-scaled telescope would result in the detection of about 30,000 actinides in GCRs. (C) 2009 Elsevier Ltd. All rights reserved.

    DOI

  • ELEMENTAL DISTRIBUTION IN THE LUNAR SUBSURFACE BY THE SELENE GRS OBSERVATION

    Y. Karouji, N. Hasebe, N. Yamashita, S. Kobayashi, M. Hareyama, E. Shibamura, M. -N. Kobayashi, O. Okudaira, T. Arai, M. Ebihara, T. Sugihara, H. Takeda, C. d'Uston, O. Gasnault, B. Diez, O. Forni, R. C. Reedy, K. J. Kim, K. Hayatsu, H. Nagaoka, K. Tsukada, Y. Takeda, J. Machida

    METEORITICS & PLANETARY SCIENCE   44   A106 - A106  2009.07

  • Average Numbers of Scintillation Photons and Electrons Produced by an Alpha Particle in High-Density Xenon Gas

    Mitsuteru Mimura, Shingo Kobayashi, Naoki Masuyama, Mitsuhiro Miyajima, Nobuyuki Hasebe

    JAPANESE JOURNAL OF APPLIED PHYSICS   48 ( 7 ) 076501.1 - 076501.8  2009.07

     View Summary

    The average numbers of scintillation photons and electrons produced by an a-particle with 5.49 MeV were determined in high-density xenon gas in the density range of 0.03-0.12 g/cm(3). No significant density dependence was observed for the number of excited atoms or liberated electrons. The average energies expended per excited atom (W x-value) and liberated electron (W-value) were found to be 34.1 +/- 2.4 and 20.9 +/- 0.4 eV, respectively. It was also found that some liberated electrons escape from recombination at zero electric field. (C) 2009 The Japan Society of Applied Physics

    DOI

  • Temperature and pressure conditions for the appropriate performance of charge and mass resolutions in balloon-borne CR-39 track detector for the heavy cosmic rays

    S. Kodaira, N. Yasuda, H. Tawara, K. Ogura, T. Doke, N. Hasebe, T. Yamauchi

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS   267 ( 10 ) 1817 - 1822  2009.05  [Refereed]

     View Summary

    We experimentally determined the suitable conditions of temperature and air pressure for measuring charge and mass compositions of heavy cosmic rays using CR-39 track detectors during long-duration, high-altitude balloon flights. The experiments were carried out utilizing Fe ion beams from Heavy Ion Medical Accelerator (HIMAC). Changes in the track registration sensitivity with temperature were studied at temperatures between 213 and 293 K. The charge and mass shifts around Fe ions are possibly 0.11 cu (charge unit) and 0.47 amu (atomic mass unit) at the temperature deviation between 227 and 243 K at balloon altitude. Decrease in track registration sensitivity as air pressure decreases has been observed between 13 Pa and 27 kPa. The charge and mass shifts around Fe ions are inferred to be 0.02 cu and 0.09 amu, respectively, when pressure varies between 20 and 27 kPa. During balloon flight, air pressure drops below this; therefore, care must be taken to keep the temperature and air pressure of CR-39 detectors within acceptable limits. (C) 2009 Elsevier B.V. All rights reserved.

    DOI

  • Detection of high-energy heavy ions using piezoelectric lead zirconate titanate

    Seiji Takechi, Shin-ya Morinaga, Atsuma Kurozumi, Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Hiromi Shibata, Takeshi Murakami, Yukio Uchihori, Nagaya Okada

    JOURNAL OF APPLIED PHYSICS   105 ( 8 ) 84903  2009.04

     View Summary

    The characteristics of a radiation detector fabricated with stacks of piezoelectric lead zirconate titanate (PZT) elements were studied by irradiating it with a 400 MeV/n xenon (Xe) beam for various beam pulse durations. This detector is referred to as the multilayered detector (MD). To understand the production mechanism behind the output voltage obtained from the MD, measurement of the spatial distribution of the output signals generated in the MD was attempted. It was found that the amplitude observed was dependent on the number of Xe ions per unit time and the amount of ionization loss energy of Xe ions in PZT.

    DOI

  • Laboratory calibration measurements of a piezoelectric lead zirconate titanate cosmic dust detector at low velocities

    S. Takechi, K. Nogami, T. Miyachi, M. Fujii, N. Hasebe, T. Iwai, S. Sasaki, H. Ohashi, H. Shibata, E. Gruen, R. Srama, N. Okada

    ADVANCES IN SPACE RESEARCH   43 ( 6 ) 905 - 909  2009.03

     View Summary

    A cosmic dust monitor for use onboard a spacecraft is currently being developed using a piezoelectric lead zirconate titanate element (PZT). Its characteristics of the PZT sensor is studied by ground-based laboratory impact experiments using hypervelocity particles supplied by a Van de Graaff accelerator. The output signals obtained from the sensor just after the impact appeared to have a waveform that was explicitly related to the particle's impact velocity. For velocities less than similar to 6 km/s, the signal showed an oscillation pattern and the amplitude was proportional to the momentum of the impacting particle. For higher velocities, the signal gradually changed to a single waveform. The rise time of this single waveform was proportional to the particle's velocity for velocities above similar to 6 km/s. The present paper reports on results for the low velocity case and especially discusses the effect of an outer coating of the sensor with a paint, which is used to reduce heating by solar radiation. (C) 2009 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • Solar particle dynamics during magnetic storms of July 23-27, 2004

    S. N. Kuznetsov, L. L. Lazutin, M. I. Panasyuk, L. I. Starostin, Yu. V. Gotseliuk, N. Hasebe, K. Sukurai, M. Hareyama

    ADVANCES IN SPACE RESEARCH   43 ( 4 ) 553 - 558  2009.02

     View Summary

    It is a case study of a chain of three magnetic storms with a special attention to the particle dynamics based on CORONAS-F and SERVIS-1 low altitude satellite measurements. Solar proton penetration inside the polar cap and inner magnetosphere and dynamics at different phases of the magnetic storms was studied. We found, that solar protons were captured to the inner radiation belt at the recovery phase of the first and the second magnetic storms and additionally accelerated during the last one. No evidence of sudden commencement (SC) particle injection was found. Enhanced solar proton belt intensity with small pitch angles decreased slowly during satellite orbits for 30 days until the next magnetic storm. Then in 20-30 h we registered strong precipitation of these protons followed by the trapped proton flux dropout. Intensity decrease was more pronounced at lower altitudes and higher particle energies. (C) 2008 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • Estimating the impact parameters of cosmic dust particles using a piezoelectric lead zirconate titanate detector

    S. Takechi, T. Miyachi, M. Fujii, N. Hasebe, K. Nogami, H. Ohashi, S. Sasaki, H. Shibata, T. Iwai, E. Gruen, R. Srama, N. Okada

    JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS   71 ( 2 ) 191 - 193  2009.02

     View Summary

    A cosmic dust detector for installation on a satellite is currently being developed using piezoelectric lead zirconate titanate (PZT), which can possess both functions of the collector and the transducer. The characteristics of the PZT detector have been studied by bombarding it with hypervelocity particles supplied by a Van de Graaff accelerator. The front surface of the detector used in this study was covered with a white paint to reduce any increase in the temperature due to the solar radiation. There was a linear relationship between the rise time of the signal produced by the detector and the particle's velocities. which were above 10 km/s on impact. This implies that individual particle velocities on impact can be inferred through the empirical formula derived from the data obtained from the PZT detector. (C) 2008 Elsevier Ltd. All rights reserved.

    DOI

  • Characteristics of piezoelectric lead zirconate titanate multilayered detector bombarded with hypervelocity iron particles

    S. Takechi, T. Onishi, S. Minami, T. Miyachi, M. Fujii, N. Hasebe, K. Mori, K. Nogami, H. Ohashi, S. Sasaki, H. Shibata, T. Iwai, E. Gruen, R. Srama, N. Okada

    ADVANCES IN SPACE RESEARCH   43 ( 3 ) 455 - 459  2009.02

     View Summary

    A cosmic dust detector is currently being developed using a piezoelectric lead zirconate titanate (PZT) element. The characteristics of the multilayered detector (MD), which was composed of one hundred PZT disks, were investigated by bombarding it with hypervelocity iron particles supplied by a Van de Graaff accelerator. It was confirmed that there was a linear relationship between the signal amplitude observed from MD and the momentum of the particles. As compared with the single-layered detector (SD) that was composed of one PZT disk, it was found that the sensitivity of MD was similar to 3 times higher than that of SD within the limits of the experimental conditions. (C) 2008 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • Elemental Composition of the Lunar Surface Observed by Kaguya Gamma-Ray Spectrometer

    Karouji Yuzuru, Nagaoka Hiroshi, Takeda Yuko, Tsukada Koichi, Machida Jiro, Warashina Yoshitomo, Morita Mikio, Hasebe Nobuyuki, Yamashita Naoyuki, Kobayashi Shingo, Hareyama Makoto, Kobayashi Masanori, Shibamura Eido, Okudaira Osamu, Hayatsu Kanako

    Abstracts for Annual Meeting of Japan Association of Mineralogical Sciences   2009 ( 0 ) 25 - 25  2009

     View Summary

    The lunar explorer "Kaguay" (SELENE) observed the Moon for 1.5 years and completed its mission. Kaguya Gamma-Ray Spectrometer (KGRS) is an instrument to mearusre the global distribution of elements on the lunar surface by obsering gamma rays emitted from the Moon. Nuclear spectroscopy obtains the element and its concentration related the energy and intensity of gamma ray from the lunar surface. Therefore, a germanium detector with a high energy resolution is adopted as KGRS for the first time in lunar missions. KGRS provides accurate global abundance of the elements on the lunar surface. In this presentation, newly scientific results from KGRS as well as the fundamental principle of gamma ray spectroscopy, observation events of KGRS, and analytical method of KGRS data are reported.

    DOI CiNii

  • INDEPENDENT COMPONENT ANALYSIS OF THE GAMMA RAY SPECTROMETER DATA OF SELENE (KAGUYA).

    O. Forni, O. Gasnault, B. Diez, C. d'Uston, S. Maurice, N. Hasebe, O. Okudaira, N. Yamashita, S. Kobayashi, Y. Karouji, M. Hareyama, M. Kobayashi, R. C. Reedy, K. J. Kim

    2009 FIRST WORKSHOP ON HYPERSPECTRAL IMAGE AND SIGNAL PROCESSING: EVOLUTION IN REMOTE SENSING     33 - +  2009  [Refereed]

     View Summary

    We analyze the spectra measured by the Gamma Ray Spectrometer (GRS) on board the SELENE satellite orbiting the Moon. The spectra consist in 8192 energy channels ranging from 0 to 12 MeV and exhibiting lines of interest (O, Mg, Al, Si, Ti, Ca, Fe, K, Th, and U) superposed on a continuum. We have also analysed the data with various multivariate techniques, one of them being the Independent Component Analysis. We have used the JADE algorithm for our analysis that we focused in the energy range from 750 to 3000 keV. We identify at least three meaningful components. The first one is correlated to the Thorium map. The corresponding correlation coefficient spectrum exhibits the lines of Thorium, Potassium and Uranium. The second component is clearly correlated with the Iron as shown on its corresponding spectrum. Finally the third component seems to be related to the altitude of the spacecraft. This work shows that maps of elements such as iron will be available with the GRS data by a purely statistical analysis.

  • First results of high performance ge gamma-ray spectrometer onboard lunar orbiter selene (kaguya)

    N. Hasebe, E. Shibamijra, T. Miyaohi, T. Takashima, M. N. Kobayashi, O. Okijdaira, N. Yamashita, S. Kobayashi, Y. Karojjji, M. Hareyama, S. Kodaira, S. Komatsu, K. Hayatsjj, K. Iwabuchi, S. Nemoto, K. Sakurai, M. Miyajima, M. Ebihara, T. Hihara, T. Arai, T. Sugihara, H. Takeda, C. D'Uston, O. Gasnault, B. Diez, O. Forni, S. Maurice, R. C. Reedy, K. J. Kim

    Journal of the Physical Society of Japan   78 ( A.(2009)18-25. ) 18 - 25  2009

     View Summary

    The high precision gamma-ray spectrometer (GRS) is carried on the first Japan's large- scaled lunar explorer, SELENE (KAGUYA), successfully launched by the H-IIA rocket on Sep. 14, 2007. The GRS consists of a large Ge crystal as a main detector and massive bismuth germanate crystals and a plastic scintillator as anticoincidence detectors. After a series of initial health check of the GRS, it started a regular observation on December 21, 2007. Energy spectra including many clear peaks of major elements and trace elements on the lunar surface have been measured by the GRS. Global measurement of thorium counting rate on the lunar surface is presented. The region showing the highest count rate of thorium extends from Kepler to Fra Mauro region in the Procellarum. And Apennine Bench and Aristillus region and the northwestern region of Mare Imbrium are high in thorium count rate. Second high count rate region is located in the South Pole-Aitken basin of the farside. Arago and Compton/Belkovich craters are also enriched in thorium. The initial results observed by GRS during the period from Dec. 21, 2007 to Feb. 17, 2008 is reviewed. © 2009 The Physical Society of Japan.

    DOI

  • HZE particle and neutron dosages from cosmic rays on the lunar surface

    Kanako Hayatsu, Makoto Hareyama, Shingo Kobayashi, Naoyuki Yamashita, Kunitomo Sakurai, Nobuyuki Hasebe

    Journal of the Physical Society of Japan   78   149 - 152  2009  [Refereed]

     View Summary

    The lunar surface is directly exposed to galactic cosmic rays (GCRs) and solar energetic particles (SEPs) because of the lack of atmosphere and magnetic field on the Moon. These charged particles successively interact with the lunar material and then produce secondary radiations as neutrons and gamma rays. The annual ambient dose equivalent on the lunar surface is estimated about 840 mSv/yr during the quiet period at the solar activity minimum. Particularly, GCR heavy component largely contributes by about 80% to the annual dose equivalents. The ambient dose equivalents of SEPs are also calculated for two transient solar particles events on October 28th in 2003 and January 20th 2005. The SEP protons take the largest contribution of about 90% to the dose, while the heavy components of SEPs do not contribute so much unlike GCRs. The ambient dose equivalent due to the SEP event on 2003 exceeds 2 Sv on the lunar surface. It is clear, however, that an aluminum shield with a thickness of 10 g/cm2 effectively reduces the dose to 0.1% of total because the solar event has a soft energy spectrum. © 2009 The Physical Society of Japan.

    DOI

  • Xenon time projection chamber for next-generation planetary missions

    Mitsuteru Mimura, Hiroki Kusano, Shingo Kobayashi, Mitsuhiro Miyajima, Nobuyuki Hasebe

    Journal of the Physical Society of Japan   78 ( SUPPL. A ) 157 - 160  2009

     View Summary

    Imaging of 7 rays with 1 ~ 5 MeV with a xenon time projection chamber (Xe-TPC) has been simulated with the GEANT4 code. The clear image of a 7-ray source was obtained using the Xe-TPC. The dependence of angular resolution and imaging efficiency on xenon density were also investigated over the density range from 0.06 to 0.18 g/cm3. It was found that a Xe-TPC is promising for imaging of high-energy 7-rays (~ 5 MeV) on planetary surface. © 2009 The Physical Society of Japan.

    DOI

  • Overview of Elemental Distributions on the Moon Observed by SELENE GRS

    N. Hasebe, N. Yamashita, Y. Karouji, S. Kobayashi, M. Hareyama, K. Hayatsu, S. Nemoto, K. Iwabuchi, Y. Takeda, H. Nagaoka, K.Tsukada, O. Okudaira, S. Sakurai, S. Komatsu, E. Shibamura, M.-N. Kobayashi, M. Ebihara, T. Hihara, T. Arai, T. Sugihara, H. Takeda, C. d’Uston, O. Gasnault, B. Diez, O. Forni, S. Maurice, R. C. Reedy, K. Kim

    International Symposium on Space Technology and Science ISTS Web Paper Archives,2009-o-3-10v   2009-o-3-10v  2009

  • Narrow spikes enhanced by electron precipitation under the inner radiation belt

    Naoki Masuyama, Makoto Hareyama, Satoshi Kodaira, Kunitomo Sakurai, Nobuyuki Hasebe

    Journal of the Physical Society of Japan   78   146 - 148  2009

     View Summary

    The observation of energetic particles trapped in the magnetosphere has made clear that narrow spikes of these particles as observed at L~1.6 are causally generated by the precipitation of particles trapped in the inner radiation belt. Furthermore, the occurrence frequency of these spikes is well correlated with the local time as coincident with the radio power transmitted from a VLF station located in west Australia, NWC. The results suggest that narrow spikes observed at L~1.6 are mainly caused by the radio power from VLF transmitter, NWC located in Australia. © 2009 The Physical Society of Japan.

    DOI

  • Long-term variation of the solar activity and its possible connection with the earth's climate condition and cosmic ray modulation

    Kunitomo Sakurai, Makoto Hareyama, Satoshi Kqdaira, Nobuyuki Hasebe

    Journal of the Physical Society of Japan   78   7 - 11  2009

     View Summary

    The sun is quite variable in time. When the solar activity is numerated by counting sunspots in number, there exists a so-called eleven year periodicity on the relative sunspot numbers, although this periodicity varies from about 7 to 13 years. The total relative sunspot numbers for respective solar cycles have been increasing almost monotonically for more than 100 years since 1882. This long-term variation as seen on these numbers may have been causally associated with the decrease of the rotation speed at the equator of the sun which has been endured throughout those years since 1882. This long-term increase of the solar activity necessarily introduces its associated increase of the intensity of magnetic field originated from the sun in the inner heliosphere. The intensification of this field seems to strongly influence the behavior of galactic cosmic rays deep in the inner heliosphere and thus indirectly influences the sun - climate condition since the terrestrial climate may be highly dependent in the long-term decrease of the cosmic ray influx into the earth's atmosphere. © 2009 The Physical Society of Japan.

    DOI

  • Introduction to the new Korean outreach program using a GIS integrated planetary mapping system

    K.J. Kim, J. Dohm, N. Hasebe, S.-S. Lee

    60th International Astronautical Congress 2009 (IAC 2009)   10(2009)   8578 - 8584  2009

  • High speed microscope for large scale ultra heavy nuclei search using solid state track detector

    N. Yasuda, S. Kodaira, M. Kurano, H. Kawashima, H. Tawara, T. Doke, K. Ogura, N. Hasebe

    Journal of the Physical Society of Japan   78   142 - 145  2009

     View Summary

    A large scale observation program of ultra heavy nuclei (Z&gt
    30) in galactic cosmic rays (UH- GCRs) is planned with the use of solid-state track detectors (SSTD) such as CR-39 plastic and BP-1 glass on the International Space Station and on board long-duration balloon flights. The handling of SSTDs usually requires a large number of year x person to scan and analyze the etch pits produced on the detector. It is due to the manual or semi-automatic analysis using a conventional optical microscope system. We plan to use a cosmic ray telescope with a large exposure area of 20 m2 made of the SSTD stacks. Detector handling will be more difficult as compared with before. A major problem for such a large scale experiment is how to quickly and precisely analyze the etch pit obtained over a short period. We have developed a new microscope system, the HSP-1000, for high speed image acquisition that uses a line sensor camera in place of a traditional CCD camera. Continuous, automatic focusing of the microscope is achieved by means of an optical pick-up system that provides fast feedback for control of distance between the objective and the image surface. As a result of continuous stage motion and continuous focusing, we have attained image acquisition speeds that are 50 - 100 times faster than conventional CCD-based microscope systems. In this paper, we present the current status of developments of the high speed microscopic measurement system, fully automated plate changing system and estimations of analyzing time for large scale observations of ultra heavy nuclei. © 2009 The Physical Society of Japan.

    DOI

  • HZE particle and neutron dosages from cosmic rays on the lunar surface

    Kanako Hayatsu, Makoto Hareyama, Shingo Kobayashi, Naoyuki Yamashita, Kunitomo Sakurai, Nobuyuki Hasebe

    Journal of the Physical Society of Japan   78   149 - 152  2009

     View Summary

    The lunar surface is directly exposed to galactic cosmic rays (GCRs) and solar energetic particles (SEPs) because of the lack of atmosphere and magnetic field on the Moon. These charged particles successively interact with the lunar material and then produce secondary radiations as neutrons and gamma rays. The annual ambient dose equivalent on the lunar surface is estimated about 840 mSv/yr during the quiet period at the solar activity minimum. Particularly, GCR heavy component largely contributes by about 80% to the annual dose equivalents. The ambient dose equivalents of SEPs are also calculated for two transient solar particles events on October 28th in 2003 and January 20th 2005. The SEP protons take the largest contribution of about 90% to the dose, while the heavy components of SEPs do not contribute so much unlike GCRs. The ambient dose equivalent due to the SEP event on 2003 exceeds 2 Sv on the lunar surface. It is clear, however, that an aluminum shield with a thickness of 10 g/cm2 effectively reduces the dose to 0.1% of total because the solar event has a soft energy spectrum. © 2009 The Physical Society of Japan.

    DOI

  • Germanium gamma-ray spectrometer on selene (kaguya)

    Naoyuki Yamashita, Nobuyuki Hasebe, Eido Shibamura, Takashi Miyaohi, Takeshi Takashima, Masanori Kobayashi, Osamu Okudaira, Shingo Kobayashi, Makoto Hareyama, Yuzuru Karouji, Satoshi Kodaira, Kunitomo Sakurai, Kazuya Iwabuchi, Kanako Hayatsu, Shinpei Nemoto, Mitsuru Ebihara, Takeshi Hihara, Claude D'Uston, Sylvestre Maurice, Olivier Gasnault, Olivier Forni, Benedicte Diez, Robert C. Reedy, Kyeong J. Kim

    Journal of the Physical Society of Japan   78   153 - 156  2009

     View Summary

    The Japanese lunar explorer SELENE was launched from Tanegashima Space Center on September 14, 2007. It consists of a main orbiter KAGUYA at 100 km altitude and two daughter satellites (relay satellite OKINA and VRAD satellite OUNA) with 14 scientific instruments. The high precision gamma-ray spectrometer (GRS) on KAGUYA measures 200 keV - 12 MeV gamma rays to determine the elemental composition of the lunar surface. The GRS is composed of a large Ge crystal as a main detector and massive bismuth germinate (BGO) crystals and a plastic scintillator as anticoincidence detectors. The Ge detector is cooled by a Stirling cryocooler below 90 K during the observation. After successful launch of the spacecraft and initial checkouts, the GRS started the nominal observation on December 21, 2007, and the temperatures and counting rates of the GRS were confirmed to be stable. Energy spectra of gamma rays with a good energy resolution are being obtained over the lunar surface, which will allow us to make global maps of the elemental abundances of the Moon soon. © 2009 The Physical Society of Japan.

    DOI

  • First results of high performance ge gamma-ray spectrometer onboard lunar orbiter selene (kaguya)

    N. Hasebe, E. Shibamijra, T. Miyaohi, T. Takashima, M. N. Kobayashi, O. Okijdaira, N. Yamashita, S. Kobayashi, Y. Karojjji, M. Hareyama, S. Kodaira, S. Komatsu, K. Hayatsjj, K. Iwabuchi, S. Nemoto, K. Sakurai, M. Miyajima, M. Ebihara, T. Hihara, T. Arai, T. Sugihara, H. Takeda, C. D'Uston, O. Gasnault, B. Diez, O. Forni, S. Maurice, R. C. Reedy, K. J. Kim

    Journal of the Physical Society of Japan   78   18 - 25  2009

     View Summary

    The high precision gamma-ray spectrometer (GRS) is carried on the first Japan's large- scaled lunar explorer, SELENE (KAGUYA), successfully launched by the H-IIA rocket on Sep. 14, 2007. The GRS consists of a large Ge crystal as a main detector and massive bismuth germanate crystals and a plastic scintillator as anticoincidence detectors. After a series of initial health check of the GRS, it started a regular observation on December 21, 2007. Energy spectra including many clear peaks of major elements and trace elements on the lunar surface have been measured by the GRS. Global measurement of thorium counting rate on the lunar surface is presented. The region showing the highest count rate of thorium extends from Kepler to Fra Mauro region in the Procellarum. And Apennine Bench and Aristillus region and the northwestern region of Mare Imbrium are high in thorium count rate. Second high count rate region is located in the South Pole-Aitken basin of the farside. Arago and Compton/Belkovich craters are also enriched in thorium. The initial results observed by GRS during the period from Dec. 21, 2007 to Feb. 17, 2008 is reviewed. © 2009 The Physical Society of Japan.

    DOI

  • Distribution of K, Th and U Concentration on the Moon: The Initial Observation by SELENE GRS

    Y. Karouji, N. Hasebe, N. Yamashita, S. Kobayashi, M. Hareyama, Shibamura, M. Kobayashi, O. Okudaira, T. Arai, M. Ebihara, T. Sugihara, H. Takeda, C. d'Uston, O. Gasnault, B. Diez, O. Forni, R.C. Reedy, K. Kim, K. Hayatsu, H. Nagaoka, K. Tsukada, Y. Takeda, J. Machida

    Advanced Geoscience 6 in press   Advanced Geoscience 6 in press  2009

  • Application of neutron activation for elemental analysis in lunar meteorite NWA2200

    H. Nagaoka, Y. Karouji, K. Hayatsu, M. Hareyama, N. Hasebe, T. Hihara, M. Ebihara

    Radiation Detectors and Their Uses, High Energy Accelerator Research Organization (KEK), 22(2009)   22   114 - 115  2009

  • A program for the precise observations of ultra heavy nuclei in galactic cosmic rays

    S. Kodaira, T. Doke, N. Hasebe, M. Hareyama, T. Miyaohi, M. Mlyajima, K. Sakurai, S. Ota, M. Sato, Y. Shimizu, M. Takano, S. Torii, N. Yasuda, S. Nakamura, H. Tawara, K. Ogura, S. Mikado, H. Shibuya, K. Nakazawa

    Journal of the Physical Society of Japan   78   138 - 141  2009

     View Summary

    The origin of galactic cosmic rays (GCRs) nuclei is still unknown. Precise observation of ultra heavy GCRs would be an important step in resolving their origin including the remaining problems in cosmic ray astrophysics. A program to observe UH nuclei in GCRs is proposed which involves the use of a high performance solid-state track detector on board a long-duration balloon. The program focuses measuring the elemental and isotopic compositions of UH nuclei up to the actinides. The observation of nuclear composition covers a wide range of scientific themes including studies of nucleosynthesis in cosmic ray sources, chemical evolution of galactic material, the characteristic time of cosmic rays, and heating and acceleration mechanisms of cosmic ray particles. © 2009 The Physical Society of Japan.

    DOI

  • Measurement of temperature after hypervelocity collision of microparticles in the range from 10 to 40 km/s

    Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Mitsuhiro Miyajima, Osamu Okudaira, Seiji Takechi, Toshiyuki Onishi, Shigeyuki Minami, Hiromi Shibata, Hideo Ohashi, Takeo Iwai, Ken-ichi Nogami, Sho Sasaki, Eberhard Gruen, Ralf Srama, Nagaya Okada

    APPLIED PHYSICS LETTERS   93 ( 17 ) 174107  2008.10

     View Summary

    The temperature recorded immediately after hypervelocity collision of microparticles comprising iron and nickel with a silver-coated piezoelectric plate was analyzed using photomultipliers of different spectral response characteristics. The conversion rate between the velocity and temperature is estimated to be similar to 900 K/km/s in the velocity range of 10-40 km/s. This rate is greater than that reported earlier. c 2008 American Institute of Physics. [DOI: 10.1063/1.3013313]

    DOI

  • Characteristics of piezoelectric lead zirconate titanate fourteen-layered detector bombarded with high-energy xenon beam

    Seiji Takechi, Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Kunishiro Mori, Hiromi Shibata, Takeshi Murakami, Yukio Uchihori, Nagaya Okada

    SENSORS AND ACTUATORS A-PHYSICAL   147 ( 2 ) 365 - 368  2008.10

     View Summary

    A radiation detector composed of fourteen lead zirconate titanate (PZT) disks was studied by directly irradiating it using a 400 MeV/n xenon beam while changing the beam intensity and beam pulse duration. The results obtained indicated that the sensitivity of the detector per xenon ion was explicitly dependent on the beam pulse duration. Comparing the sensitivity among PZT detectors with one, fourteen and one hundred layers, it was also found that the sensitivity of the fourteen-layered detector was highest under the experimental conditions. (C) 2008 Elsevier B.V. All rights reserved.

    DOI

  • Erratum to "New method of the precise measurement for the thickness and bulk etch rate of the solid-state track detector". [Nucl. Instr. and Meth. A 574 (2007) 163-170] (DOI:10.1016/j.nima.2007.01.086)

    S. Kodaira, N. Yasuda, N. Hasebe, T. Doke, S. Ota, K. Ogura

    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment   593 ( 3 ) 639  2008.08  [Refereed]

    DOI

  • Measurements of Electron Drift Velocity in He-3 Gas

    Hiroki Kusano, Mitsuteru Mimura, Shinzo Kobayashi, Mitsuhiro Miyajima, Nobuyuki Hasebe

    JAPANESE JOURNAL OF APPLIED PHYSICS   47 ( 8 ) 6475 - 6477  2008.08

     View Summary

    Electron drift velocities in He-3 and He-4 gases were measured at 0.1 MPa and we compared the results ill He-3 and He-4 under the electric field strength normalized by the number density of helium gas, E/N, from 0.04 to 1.0 Td. This is the first experimental confirmation of the fact that the electron drift velocity in He-3 gas is larger than in He-4 gas. The difference in the electron drift velocities is attributed to the difference in the atomic masses of He-3 and He-4.

    DOI

  • Development of an automated multisample scanning system for nuclear track etched detectors

    H. Tawara, K. Eda, K. Takahashi, T. Doke, N. Hasebe, S. Kodaira, S. Ota, M. Kurano, N. Yasuda

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   593 ( 3 ) 475 - 480  2008.08

     View Summary

    We have developed an automated scanning system for handling a large number of nuclear track etched detectors (NTEDs). The system consists of a magazine station for sample storage, a robotic sample loader, a high-speed wide-area digital imaging microscope device (modified HSP-1000) and PitFit software for analyzing etch pits. We investigated the performance of the system using CR-39 plastic NTED samples exposed to high-energy heavy ions and fast neutrons. When applying the system to fast neutron dosimetry, the typical scanning speed was about 100 samples/day with a scan area of 4 cm(2)/sample. The neutron doses obtained from a fully automatic measurement agreed closely with those from a semi-automatic measurement. These results indicate the feasibility of fully automatic scanning of CR-39 personal neutron dosimeters. The system is also expected to be applicable to future large-scale experiments using CR-39 plastic and BP-1 glass NTEDs for observing ultraheavy galactic cosmic rays with high mass resolution. (C) 2008 Elsevier B.V. All rights reserved.

    DOI

  • Tracking method for the measurement of projectile charge changing cross-section using CR-39 detector with a high speed imaging microscope

    S. Ota, S. Kodaira, N. Yasuda, E. R. Benton, M. Hareyama, A. Kurano, M. Sato, D. Shu, N. Hasebe

    RADIATION MEASUREMENTS   43 ( SUPPL.1 ) S195 - S198  2008.07  [Refereed]

     View Summary

    A new method to trace heavy ion trajectories in a stack consisting of interleaved CR-39 plastic nuclear track detectors and target material layers was developed and tested for use in the measurement of projectile charge changing cross-sections of heavy ion fragmentation reactions. A high speed imaging microscope with sophisticated track analysis software was utilized to extract the charge information from multiple ion tracks belonging to a single fragmentation event. The systematic error of trajectory tracing was verified for the measurement system. In order to verify the validity of system, the projectile total charge changing cross-sections for Fe ions on carbon target was estimated and compared with previous experiments at initial beam energy of 1GeV/n. The result is in good agreement with results obtained by other investigators. This method allows precise and fast measurement of the projectile charge changing cross-section with higher statistics on a level compatible to that of silicon spectrometer measurements. (C) 2008 Elsevier Ltd. All rights reserved.

    DOI J-GLOBAL

  • Track detector of CR-39-DAP-copolymer with variable threshold to detect trans-iron nuclei in galactic cosmic rays

    S. Kodaira, M. Aasaeda, T. Doke, M. Hareyama, N. Hasebe, K. Ogura, N. Yasuda, T. Tsuruta, Y. Kori

    RADIATION MEASUREMENTS   43   S52 - S55  2008.07

     View Summary

    Observation of trans-iron nuclei in galactic cosmic rays (Z >= 30) requires a high performance cosmic ray detector telescope with a large exposure area because of their extremely low fluxes. A solid-state track detector such as CR-39 has the advantage of easy extension of exposure area, but it is necessary to raise the Z/beta detection threshold in order to suppress background tracks produced by galactic cosmic rays with Z/beta< 30. The track registration sensitivity and detection threshold for heavy ions with various Z*/beta were verified by using track detectors of copolymers of CR-39 and DAP (diallyl phthalate) with various DAP concentration. We found that it is possible to control the Z*/beta detection threshold of copolymers by changing DAP concentration. In order to detect heavy ions with Z*/beta >= 30. the optimum DAP concentration was found to be approximately 50%. (C) 2008 Elsevier Ltd. All rights reserved.

    DOI

  • The high precision gamma-ray spectrometer for lunar polar orbiter SELENE

    N. Hasebe, N. Yamashita, O. Okudaira, S. Kobayashi, H. Yamamoto, T. Ishizaki, K. Hirano, K. Sakurai, T. Miyachi, M. Miyajima, M. Fujii, M. -N. Kobayashi, T. Takashima, E. Shibamura, O. Gasnault, S. Maurice, C. d'Uston, R. Reedy, M. Grande

    ADVANCES IN SPACE RESEARCH   42 ( 2 ) 323 - 330  2008.07

     View Summary

    The high precision gamma-ray spectrometer (GRS) is scheduled to be launched on the lunar polar orbiter of the SELENE mission in 2007. The GRS consists of a large Ge crystal as it main detector and massive bismuth germanate crystals as an anticoincidence detector. A Stirling cryocooler was adopted in cooling the Ge detector. The flight model of SELENE GRS has been completed and an energy resolution of 3.0 keV (FWHM) at 1.332 MeV has been achieved. The spectrometer aims to observe nuclear line gamma rays emitted from the lunar surface in a wide energy range from 100 keV to 12 MeV for one year and more to obtain chemical composition on the entire lunar surface. The gamma-ray data enable us to study lunar geoscience problems including crust and mantle composition, and volatile reservoirs at polar regions. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • Position Sensitive Element for Hypervelocity Microparticles Using a Piezoelectric Plate

    Takashi Miyachi, Genei Kuraza, Atsushi Nagashima, Masayuki Fujii, Nobuyuki Hasebe, Naoyuki Yamashita, Ken-ichi Nogami, Takeo Iwai, Hideo Ohashi, Hiromi Shibata, Shigeyuki Minami, Seiji Takechi, Toshiyuki Onishi, Eberhard Gruen, Ralf Srama, Nagaya Okada

    JAPANESE JOURNAL OF APPLIED PHYSICS   47 ( 5 ) 3772 - 3775  2008.05

     View Summary

    The propagation of transverse waves generated acoustically in a piezoelectric element by colliding it with hypervelocity microparticles was studied. The propagation times were measured by a set of multiple electrodes on the surface of the element. The coordinates that the particles struck were determined by combining the propagation times and the velocity of the waves. By using the position-sensitive element, significant deviations between the prior indicated and actually measured orbits were observed. The potential of the present element as part of a steering system is discussed. [DOI: 10.1143/JJAP.47.3772]

    DOI

  • Measurement of incident position of hypervelocity particles on piezoelectric lead zirconate titanate detector

    Seiji Takechi, Toshiyuki Onishi, Shigeyuki Minami, Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Ken-ichi Nogami, Hideo Ohashi, Sho Sasaki, Hiromi Shibata, Takeo Iwai, Eberhard Grun, Ralf Srama, Nagaya Okada

    REVIEW OF SCIENTIFIC INSTRUMENTS   79 ( 4 ) 43303  2008.04

     View Summary

    A cosmic dust detector for use onboard a satellite is currently being developed by using piezoelectric lead zirconate titanate (PZT). The characteristics of the PZT detector have been studied by bombarding it with hypervelocity iron (Fe) particles supplied by a Van de Graaff accelerator. One central electrode and four peripheral electrodes were placed on the front surface of the PZT detector to measure the impact positions of the incident Fe particles. It was demonstrated that the point of impact on the PZT detector could be identified by using information on the time at which the first peak of the output signal obtained from each electrode appeared. (C) 2008 American Institute of Physics.

    DOI

  • Ultraviolet-sensitive windowless silicon PIN photodiodes for alpha-ray spectrometry

    Mitsuteru Mimura, Nobuyuki Hasebe, Shingo Kobayashi, Mitsuhiro Miyajima, Tadayoshi Doke, Eido Shibamura

    JAPANESE JOURNAL OF APPLIED PHYSICS   47 ( 3 ) 1740 - 1741  2008.03

     View Summary

    Energy resolution measurements of ultraviolet-sensitive windowless silicon p-i-n photodiodes were carried out with alpha rays. A resolution of 12.6 keV in full width at half maximum for 5.486 MeV was achieved. The ultraviolet-sensitive silicon p-i-n photodiodes were found to be suitable to alpha-ray spectrometry.

    DOI

  • Radiation detector based on piezoelectric lead zirconate titanate material

    Seiji Takechi, Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Kunishiro Mori, Hiromi Shibata, Takeshi Murakami, Yukio Uchihori, Nagaya Okada

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   586 ( 2 ) 309 - 313  2008.02

     View Summary

    The feasibility of using piezoelectric lead zirconate titanate (PZT) elements as a radiation detector was examined. We tried to observe the pressure wave excited by irradiating liquid ethanol (C2H5OH) with a 400 MeV/n xenon (Xe) beam using an array of PZT elements, while changing the position of beam irradiation. The elements were designed to obtain two independent electric signals in order to estimate the beam position in one direction on a two-dimensional plane. The time at which the peak of the output signal appeared differed between the two signals obtained from one element under limited experimental conditions. This suggests that the trajectory of the Xe beam may be determined in three-dimensional space with an improved array of the PZT elements. (C) 2007 Elsevier B.V. All rights reserved.

    DOI

  • ENVIRONMENTAL RADIATION DOSE ON THE MOON

    K. Hayatsu, S. Kobayashi, N. Yamashita, M. Hareyama, K. Sakurai, N. Hasebe

    ASTROPARTICLE, PARTICLE AND SPACE PHYSICS, DETECTORS AND MEDICAL PHYSICS APPLICATIONS   4   792 - 796  2008  [Refereed]

     View Summary

    Ambient dose equivalent on the lunar surface is estimated as contribution from galactic cosmic rays, secondary neutrons and gamma rays from the lunar surface. Since the cosmic ray flux on the lunar surface varies with the phase of the solar activity, radiation doses on the surface are calculated of the three cases of this activity; the maximum, the minimum and the average. To estimate the doses of the secondary particles, Monte Carlo simulation library Geant4 is applied. As a result, total annual dose equivalent of about 225 mSv/yr on the lunar surface is expected during the quiet time of solar activity. The dose of neutrons and gamma rays reaches to 50 mSv/yr and 2 mSv/yr, respectively. In particular, fast neutrons have the largest contribution to the total neutron dose. The dependency of total neutron dose for mare and highland region of the Moon is small on the lunar surface as comparing with that for solar activity.

  • INTENSITY VARIATION OF GAMMA RAYS DUE TO WATER CONCENTRATIONS ON THE LUNAR SURFACE

    K. Iwabuchi, N. Yamashita, S. Kobayashi, K. Hayatsu, M. Hareyama, Y. Karouji, K. Sakurai, N. Hasebe

    ASTROPARTICLE, PARTICLE AND SPACE PHYSICS, DETECTORS AND MEDICAL PHYSICS APPLICATIONS   4   829 - 833  2008  [Refereed]

     View Summary

    Fluxes of gamma rays emitted from the lunar surface consisting from ferroan anorthosite with various concentration of water (H2O) were calculated with Geant4. They are useful to the current and future lunar missions for the projects to search for the existence of water in the lunar polar regions with a gamma-ray spectrometer. The result thus obtained indicates that the flux of gamma-rays with 2223 keV due to the reactions H-1(n, gamma)D-2 has a monotonous dependence on the concentration of H2O from 0.1 to 20 wt% and the flux of 4934 keV gamma-rays due to the reactions Si-28(n, gamma)Si-29 is remarkably correlated with the abundance of H2O. The variation of these gamma-ray fluxes dependent on the concentration of H2O is also discussed with the neutron density profile in the lunar subsurface.

  • THE CALET SPACE OBSERVATORY FOR JEM-EF ON THE INTERNATIONAL SPACE STATION

    J. P. Wefel, S. Torii, Y. Shimizu, K. Kasahara, N. Hasebe, M. Hareyama, S. Kodaira, O. Okudaira, N. Yamashita, M. Miyazima, T. Miyaji, M. Tkayanagi, S. Ueno, H. Tomida, Y. Saito, H. Fuke, T. Yamagami, J. Nishimura, T. Tamura, N. Tateyama, K. Hibino, S. Okuno, A. Shiomi, M. Takita, T. Yuda, F. Kakimoto, Y. Tsunesada, T. Terasawa, T. Kobayashi, A. Yoshida, K. Yamaoka, Y. Katayose, M. Shibata, M. Ichimura, S. Kuramata, Y. Uchihori, A. Kitamura, K. Yoshidai, H. Murakami, Y. Komori, K. Mizutani, K. Munakata, R. E. Streitmatter, J. W. Mitchell, L. M. Barbier, A. A. Moiseev, J. F. Krizmanic, J. F. Ormes, G. Case, M. L. Cherry, T. G. Guzik, J. B. Isbert, W. R. Binns, M. H. Israel, H. S. Krawczynski, P. S. Marrocchesi, G. Bigongiari, K. Batkov, M. Y. Kim, M. G. Bagliesi, P. Masestro, V. Millucci, R. Zei, O. Adriani, P. Papini, E. Vannuccini, L. Bonechi, J. Chang, J. Yan, W. Gan, G. Chen, Y. Ma, H. Wang

    ASTROPARTICLE, PARTICLE AND SPACE PHYSICS, DETECTORS AND MEDICAL PHYSICS APPLICATIONS   4   911 - +  2008

     View Summary

    The CALorimetric Electron Telescope, CALET, is a new Space Observatory being developed for the Japanese Experiment Module Exposed Facility, JEM-EF, of the International Space Station. Major scientific objectives are to search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electron spectrum from 10's of GeV - 10 TeV and of gamma rays in the range 20 MeV - several TeV. CALET has a unique capability to observe electrons and gamma-rays over 1 TeV, with a hadron rejection power better than 105 and an energy resolution of a few % beyond 100 GeV. Moreover, CALET will follow PAMELA, GLAST and other experiments and can both extend and refine the observations made by those missions. The main instrument, to be described, consists of an imaging calorimeter combined with a total absorption calorimeter. With auxiliary detectors, the CALET Observatory will also monitor solar activity and study gamma-ray bursts. The phase A/B study is underway for a proposed 2013 launch on the H-II Transfer Vehicle (HTV) for 3- 5 years of observation on JEM-EF.

  • Environmental Radiation Dose on the Moon; Astroparticle, Particle and Space Physics, Detectors and Medical Physics Applications

    K. Hayatsu, S. Kobayashi, N. Yamashita, M. Hareyama, K. Sakurai, N. Hasebe

    Proceedings of the 10th Conference(2008)792-796, ICATPP 2007 Como, Italy, DOI: 10.1142/9789812819093_0131   DOI: 10.1142/9789812819093_013   792 - 796  2008

  • CAET Mission on the ISS

    S. Torii, M. Hareyama, N. Hasebe, K. Kasahara, S. Kobayashi, S. Kodaira, H. Murakami, S. Ozawa, S. Udo, N. Yamashita, K. Ebisawa, H. Fuke, J. Nishimura, Y. Saito, M. Takayanagi, H. Tomida, S. Ueno, T. Yamagami, K. Hibino, S. Okuno, T. Tamura, N. Tateyama, T. Kobayashi, T. Kotani, K. Yamaoka, A. Yoshida, Y. Shimizu, M. Takita, T. Yuda, Y. Katayose, M. Shibata, E. Kamioka, A. Kubota, K. Yoshida, M. Ichimura, S. Kuramata, Y. Tunesada, T. Terasawa, H. Kitamura, Y. Uchihori, Y. Komori, K. Mizutani, K. Munakata, A. Shiomi, J. W. Michell, A. J. Ericsson, T. Hams, J. F. Krizmanic, A. A. Moissev, M. Sasaki, J. F. Ormes, M. L. Cherry, T. G. Guzik, J. P. Wefel, W. R. Binns, M. H. Israel, H. Krawzczynski, P. S. Marrocchesi, M. G. Gagliesis, G. Bigongiari, A. Caldarone, M. Y. Kim, R. Cecchi, P. Maestro, V. Millucci, R. Zei, C. Avanzini, T. Lotadze, A. Messineo, F. Morsani, O. Adriani, L. Bonechi, P. Papini, E. Vannuccini, J. Chan, W. Gan, T. Lu, Y. Ma, H. Wang, G. Chen

    HIGH ENERGY, OPTICAL, AND INFRARED DETECTORS FOR ASTRONOMY III   7021  2008

     View Summary

    We are developing the CALorimetric Electron Telescope, CALET, mission for the Japanese Experiment Module Exposed Facility, JEM-EF, of the International Space Station. Major scientific objectives are to search for the nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electrons in 1 GeV - 20 TeV and gamma rays in 20 MeV - several 10 TeV. CALET has a unique capability to observe electrons and gamma rays over 1 TeV since the hadron rejection power can be larger than 105 and the energy resolution better than a few % over 100 GeV. The detector consists of an imaging calorimeter with scintillating fibers and tungsten plates and a total absorption calorimeter with BGO scintillators. CALET has also a capability to measure cosmic ray H, He and heavy ions up to 1000 TeV. It also will have a function to monitor solar activity and gamma ray transients. The phase A study has started on a schedule of launch in 2013 by H-II Transfer Vehicle (HTV) for 5 year observation.

    DOI

  • THE CALET SPACE OBSERVATORY FOR JEM-EF ON THE INTERNATIONAL SPACE STATION

    J. P. Wefel, S. Torii, Y. Shimizu, K. Kasahara, N. Hasebe, M. Hareyama, S. Kodaira, O. Okudaira, N. Yamashita, M. Miyazima, T. Miyaji, M. Tkayanagi, S. Ueno, H. Tomida, Y. Saito, H. Fuke, T. Yamagami, J. Nishimura, T. Tamura, N. Tateyama, K. Hibino, S. Okuno, A. Shiomi, M. Takita, T. Yuda, F. Kakimoto, Y. Tsunesada, T. Terasawa, T. Kobayashi, A. Yoshida, K. Yamaoka, Y. Katayose, M. Shibata, M. Ichimura, S. Kuramata, Y. Uchihori, A. Kitamura, K. Yoshidai, H. Murakami, Y. Komori, K. Mizutani, K. Munakata, R. E. Streitmatter, J. W. Mitchell, L. M. Barbier, A. A. Moiseev, J. F. Krizmanic, J. F. Ormes, G. Case, M. L. Cherry, T. G. Guzik, J. B. Isbert, W. R. Binns, M. H. Israel, H. S. Krawczynski, P. S. Marrocchesi, G. Bigongiari, K. Batkov, M. Y. Kim, M. G. Bagliesi, P. Masestro, V. Millucci, R. Zei, O. Adriani, P. Papini, E. Vannuccini, L. Bonechi, J. Chang, J. Yan, W. Gan, G. Chen, Y. Ma, H. Wang

    ASTROPARTICLE, PARTICLE AND SPACE PHYSICS, DETECTORS AND MEDICAL PHYSICS APPLICATIONS   4   911 - +  2008

     View Summary

    The CALorimetric Electron Telescope, CALET, is a new Space Observatory being developed for the Japanese Experiment Module Exposed Facility, JEM-EF, of the International Space Station. Major scientific objectives are to search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electron spectrum from 10's of GeV - 10 TeV and of gamma rays in the range 20 MeV - several TeV. CALET has a unique capability to observe electrons and gamma-rays over 1 TeV, with a hadron rejection power better than 105 and an energy resolution of a few % beyond 100 GeV. Moreover, CALET will follow PAMELA, GLAST and other experiments and can both extend and refine the observations made by those missions. The main instrument, to be described, consists of an imaging calorimeter combined with a total absorption calorimeter. With auxiliary detectors, the CALET Observatory will also monitor solar activity and study gamma-ray bursts. The phase A/B study is underway for a proposed 2013 launch on the H-II Transfer Vehicle (HTV) for 3- 5 years of observation on JEM-EF.

  • S. Ota, S. Kodaira, N. Yasuda, E.R. Benton, M. Hareyama, M. Kurano, M. Sato, D. Shu, N. Hasebe

    Tracking method, for the measurement of, projectile charge changing, cross-section using CR, detector with, a high, speed imaging microscope

    Rad. Meas. 43. Suppl. (2008)   Rad. Meas. 43. Suppl. (2008)   195 - 198  2008

  • Response of piezoelectric lead zirconate titanate detector to oblique impact with hypervelocity iron particles

    S. Takechi, T. Onishi, S. Minami, T. Miyachi, M. Fujii, N. Hasebe, K. Mori, K. Nogami, H. Ohashi, S. Sasaki, H. Shibata, T. Iwai, E. Gruen, R. Srama, N. Okada

    EARTH PLANETS AND SPACE   60 ( 12 ) 1187 - 1190  2008

     View Summary

    A cosmic dust detector using piezoelectric lead zirconate titanate (PZT) is currently being developed for use onboard a spacecraft for the BepiColombo mission. The characteristics of the PZT detector were studied by carrying out hypervelocity impact measurements with iron particles supplied by a Van de Graaff accelerator. The measurements with particle velocities of less than 5 km/s showed a linear relationship between the output voltages obtained froth the detector and the particle momenta. This linear relationship obtained was almost independent

  • Response of a pentagonal PZT element as a component of a 4 pi-real-time detector

    T. Miyachi, M. Fujii, N. Hasebe, G. Kuraza, K. Mori, O. Okudaira, N. Yamashita, S. Sasaki, T. Iwai, K. Nogami, H. Matsumoto, H. Ohashi, H. Shibata, S. Minami, S. Takechi, T. Onishi, E. Grun, R. Srama, N. Okada

    ADVANCES IN SPACE RESEARCH   41 ( 7 ) 1147 - 1151  2008

     View Summary

    The detector characteristics of a pentagonal element were studied by colliding it with hypervelocity micro-particles. A charge-sensitive amplifier was developed for the element of its capacitance similar to 10 nF. The output amplitudes were expressed as a linear function of the momentum at collision. Empirical formulas obtained from on-ground experiments could be used for the calibration of the detector. The pentagonal element was potential to measure the momentum during collision from the output amplitude. A set of electrodes on the surface was used to confirm the measurement of the coordinates at collision. A possible application of this pentagonal element on a real-time dust detector was discussed. (C) 2008 Published by Elsevier Ltd on behalf of COSPAR.

    DOI

  • Radiation Doses for Human Exposed to Galactic Cosmic Rays and Their Secondary Products on the Lunar Surface

    K. Hayatsu, M. Hareyama, S. Kobayashi, K. Sakurai, N. Hasebe

    Biolog. Sci. Space 22(2008)   Biolog. Sci. Space 22(2008)   59 - 66  2008

    DOI

  • Pressure Dependence of Ws-value in Xenon Gas

    M. Mimura, S. Kobayashi, S. Asano, N. Masuyama, M. Miyajima, N. Hasebe

    Proc. of the 22nd Workshop on Radiation Detectors and Their Uses     126 - 132  2008

  • High Performance Germanium Gamma-Ray Spectrometer On Lunar Polar Orbiter SELENE (KAGUYA)

    N. Hasebe, E. Shibamura, T. Miyachi, T. Takashima, M.-N. Kobayashi, O. Okudaira, N. Yamashita, S. Kobayashi, Y. Karouji, M. Hareyama, S. Kodaira, S. Komatsu, K. Hayatsu, K. Iwabuchi, S. Nemoto, K. Sakurai, M. Miyajima, M. Ebihara, T. Hihara, T. Arai, T. Sugihara, H. Takeda, C. d’Uston, O. Gasnault, B. Diez, O. Forni, S. Maurice, R. C. Reedy

    International Symposium on Space Technology and Science   International Symposium on Spa ( ists26 ) ISTS Web Paper Archives2008 - Pk_41  2008

    DOI

  • Gas amplification in high-pressure pure xenon proportional counters

    H. Kusano, S. T. Kobayashi, M. Mimura, S. Kobayashi, M. Miyajima, N. Hasebe

    Proceedings of the 22nd Workshop on Radiation Detectors and Their Uses   Proc. of the 22nd Workshop on   133 - 139  2008

     View Summary

    We obtained the properties of the gas amplification in pure Xe gas up to 1.0 MPa. It is found that the first Townsend ionization coefficient becomes larger in highly-purified Xe gas. The energy resolution slightly deteriorates with increasing gas pressure, but it is possible to make the gas pressure higher with keeping the energy resolution constant when the gas gain is under approximately 500. In the future work, we will attempt to improve the energy resolution of the Xe proportional counter. The energy resolution we obtained is worse compared with the limit of the energy resolution from statistics of the gas amplification process determined through the Fano factor and the parameter of the variance of gas amplification for one electron. Therefore, it remains possible of improving the energy resolution. Furthermore, we will study the properties of the gas amplification in pure Xe gas at the higher gas pressure. The study will furnish the basic data to develop the high-energy-resolution gamma-ray spectrometer at the energy of above 100 keV.

  • Gamma-Ray Spectrometer on Board KAGUYA

    E. Shibamura, N. Hasebe, T. Miyachi, M. Hareyama, Y. Karouji, O. Okudaira, N. Yamashita, S. Kobayashi, T. Tkashima, M.-N. Kobayashi

    KEK Proceedings 14(2008)     178 - 183  2008

  • Gamma-ray spectrometer (GRS) for lunar polar orbiter SELENE

    Nobuyuki Hasebe, Eido Shibamura, Takashi Miyachil, Takeshi Takashima, Masanori Kobayashi, Osamu Okudaira, Naoyuki Yamashita, Shingo Kobayashi, Takeshi Ishizaki, Kunitomo Sakurai, Mitsuhiro Miyajima, Masayuki Fujii, Keisuke Narasaki, Shigeki Takai, Katsuhiro Tsurumi, Hiroshi Kaneko, Michio Nakazawa, Kunishiro Mori, Olivier Gasnault, Sylvestre Maurice, Claude d'Uston, Robert C. Reedy, Manuel Grande

    EARTH PLANETS AND SPACE   60 ( 4 ) 299 - 312  2008

     View Summary

    The high-precision gamma-ray spectrometer (GRS) on the lunar polar orbiter SELENE is designed to measure 200 keV-12 MeV gamma rays in order to determine elemental compositions of the lunar surface. The GRS consists of a large germanium (Ge) crystal as a main detector and a massive bismuth germanate crystal and a plastic scintillator as anticoincidence detectors. The Ge detector is cooled by a Stirling cryocooler with its compressor attached to a passive radiator facing the cold space. The cooling system maintains the Ge detector below 90 K during the observation. The flight model of the GRS has achieved an energy resolution of 3.0 keV (FWHM) at 1333 keV. Energy spectra obtained by the GRS will show sharp gamma-ray lines whose energies identify the elements and whose intensities determine the concentrations of the elements, permitting global mapping of the elemental abundances in the sub-surface of the Moon. The elemental maps obtained by the GRS with such high-energy resolution enable us to study lunar geoscience problems.

  • Complexities of gamma-ray line intensities from the lunar surface

    Naoyuki Yamashita, Nobuyuki Hasebe, Takashi Miyachi, Masanori Kobayashi, Osamu Okudaira, Shingo Kobayashi, Takeshi Ishizaki, Kunitomo Sakurai, Mitsuhiro Miyajima, Robert C. Reedy, Claude d'Uston, Sylvestre Maurice, Olivier Gasnault

    EARTH PLANETS AND SPACE   60 ( 4 ) 313 - 319  2008

     View Summary

    Assuming different abundances of the Apollo lunar soil samples and the average spectrum of galactic cosmic ray protons, energy spectra of neutrons and gamma rays and emission rates of gamma-ray lines from major elements have been estimated by using the reviewed Monte Carlo simulation library Geant4 and nuclear data. Previously, such libraries were not able to reproduce gamma-ray lines properly for the planetary application. Results clearly show that the emission rate of gamma rays heavily depends not only on the chemical abundance but also neutron flux within the lunar subsurface. While the intensities of gamma-ray lines are mostly proportional to elemental abundances, the intensity per unit elemental abundance can vary. Such a complex correlation is attributed to the change in neutron flux within the lunar subsurface and petrological restriction of elemental variation.

  • Application of neutron activation for elemental analysis in lunar meteorite NWA2200

    H. Nagaoka, Y. Karouji, K. Hayatsu, T. Hihara, M. Hareyama, M. Ebihara, N. Hasebe

    KEK Proceedings 14(2008)   KEK Proceedings 14(2008)   114 - 125  2008

  • Improvement of mass resolution for iron isotopes in CR-39 track detector

    Satoshi Kodaira, Nakahiro Yasuda, Nobuyuki Hasebe, Tadayoshi Doke, Shuya Ota, Masashi Sato, Hiroko Tawara, Koichi Ogura

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS   46 ( 8A ) 5281 - 5287  2007.08

     View Summary

    The capability of the CR-39 track detector for isotope identification was verified using Fe-56 and Fe-55 beams from the heavy ion accelerator HIMAC at NIRS. A CR-39 stack was exposed to 56Fe and 55Fe beams with the energies of 460 MeV/nucleon. Drastic improvements in the accuracies of microscopic image analysis and detector thickness measurement enabled us to identify those iron isotopes with high mass resolution using the CR-39 track detector. As a consequence of the reduction of systematic errors, the mass resolution for iron isotopes in the CR-39 detector was obtained to be 0.22 +/- 0.03 amu in ruts. The mass resolution newly obtained by the CR-39 detector was compared with the former result and found to be 66% better than the former value of mass resolution as a result of reducing the systematic errors of mass dispersion. Moreover, the ultimate mass resolution of the CR-39 detector was estimated by calculation using those experimental results. As a consequence of reducing the random error, it is expected that the mass resolution for iron isotopes can ultimately approach to similar to 0.10 amu in the CR-39 detector.

    DOI

  • Evaluation of piezoelectric lead-zirconate-titanate multilayered detector by Fourier analysis

    Seiji Takechi, Toshiyuki Onishi, Shigeyuki Minami, Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Kunishiro Mori, Hiromi Shibata, Takeshi Murakami, Yukio Uchihori, Nagaya Okada

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   577 ( 3 ) 741 - 744  2007.07

     View Summary

    Radiation detectors composed of lead-zirconate-titanate (PZT) were studied by directly irradiating them with a 400 MeV/n xenon beam. Fourier analysis revealed that frequency components of the output signal obtained from the detectors explicitly depended on the beam pulse duration. The sensitivity of the multilayered detector was discussed in comparison with that of a single-layered detector. (c) 2007 Elsevier B.V. All rights reserved.

    DOI

  • Detection of acoustic wave excited in chloroform bombarded with high-energy xenon beam

    Seiji Takechi, Toshiyuki Onishi, Shigeyuki Minami, Takashi Miyachi, Masayuki Fujii, Nobuyuki Hasebe, Kunishiro Mori, Hiromi Shibata, Takeshi Murakami, Yukio Uchihori, Nagaya Okada

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   577 ( 3 ) 729 - 733  2007.07

     View Summary

    A pressure wave excited by irradiating liquid chloroform (CHCl3) with a 400 MeV/n xenon (Xe) beam was observed using a detector composed of piezoelectric lead-zirconate-titanate (PZT) elements. The acoustic signals were examined for various beam pulse durations. The amplitude obtained in the first cycle was inversely proportional to the beam pulse duration. It was also found that the time at which the peak in the first cycle appeared was dependent on the location at which each element was set. This suggests that the position at which the Xe beam stops in CHCl3 may be precisely determined with the PZT detector. (c) 2007 Elsevier B.V. All rights reserved.

    DOI

  • New method of the precise measurement for the thickness and bulk etch rate of the solid-state track detector

    S. Kodaira, N. Yasuda, N. Hasebe, T. Doke, S. Ota, K. Ogura

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   574 ( 1 ) 163 - 170  2007.04

     View Summary

    New optical system with an optical displacement sensor has been developed to measure the local thickness of CR-39 track detector. It can be applied to measure locally the thicknesses of whole detector area for making a map of the amount of bulk etch. The accuracy of the thicknesses measurement was found to be +/- 0.2 mu m using CR-39 detector. This accuracy is one order of magnitude higher than that of conventional methods, such as the Micrometer method, and is comparable to that of track size measurement under the optical microscope. It will also greatly improve the charge and mass resolutions of CR-39 detector that we can apply to measure galactic cosmic rays (GCRs) nuclei, especially the trans-iron nuclei (Z >= 30) in GCRs. (c) 2007 Elsevier B.V. All rights reserved.

    DOI

  • Comparison between two piezoelectric lead-zirconate-titanate detectors bombarded with high-energy xenon beam

    Seiji Takechi, Toshiyuki Onishi, Shigeyuki Minami, Takashi Miyachi, Masayuki Fuji, Nobuyuki Hasebe, Kunishiro Mori, Hiromi Shibata, Takeshi Murakami, Yukio Uchihori, Nagaya Okada

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS   46 ( 4A ) 1704 - 1706  2007.04

     View Summary

    The characteristics of piezoelectric lead-zirconate-titan ate (PZT) detectors were studied by directly irradiating them with a 400MeV/n Xe beam. The sensitivity of a multilayered detector was discussed in comparison with that of a monolayered detector. It was found that the sensitivity of the detectors depended on their structure.

    DOI

  • The CALET Mission for Observing High Energy Cosmic Rays on Japanese Experiment Module of ISS

    S. Torii, Y. Shimizu, N. Hasebe, N. Hareyama, S. Kodaira, J. Nishimura, T. Yamagami, Y. Saito, H. Fuke, M. Takayanagi, H. Tomida, S. Ueno, T. Tamura, N. Tateyama, K. Hibino, T. Yuda, K. Yoshida, S. Okuno, P. S. Marrocchesi, P. Maestro, M. G. Bagliesi, V. Millucci, M. Meucci, G. Bigongiari, R. Zei, R. E. Streitmatter, J. W. Mitchel, L. M. Barbier, A. A. Moiseev, J. F. Krizmanic, O. Adriani, P. Papini, P. Spillantini, L. Bonechi, E. Vannuccini, G. Case, M.L. Cherry, T.G. Guzik, J. B. Isbert, J.P. Wefel

    J. Japan Soc. Microgravity Applications 24, 1, 120 (2007).   24 ( 1 ) 120  2007

  • Environmental Radiation Dose on the Moon; Astroparticle, Particle and Space Physics, Detectors and Medical Physics Applications

    K. Hayatsu, S. Kobayashi, N. Yamashita, M. Hareyama, K. Sakurai, N. Hasebe

    Proceedings of the 10th Conference(2008)792-796, ICATPP 2007 Como, Italy   DOI: 10.1142/9789812819093_013  2007

  • “The CALET experiment on ISS

    S.Torii

    Nuclear Physics B −Proceedings Supplements   166(2007)   43 - 49  2007

  • Ws-values in 1 -2.5 atm Xenon Gases

    S. Nemoto, H. Kusano, T. Takahashi, Y. Ebizuka, S. Suzuki, J. Kikuchi, T. Doke

    Proc. of Workshop on Ionization and Scintillation Counters and Their Uses(2007)     11 - 15  2007

  • The high precision observation of ultra heavy cosmic ray nuclei

    N.Hasebe, T.Doke, M.Hareyama, S.Kodaira, T.Miyachi, M.Miyajima, O.Okudaira, K.Sakurai, M.Takano, S.Torii, N.Yamashita, N.Yasuda, H.Tawara, S.Nakamura, K.Ogura, H.Shibuya

    http://www.lip.pt/events/2006/ecrs/proc/ecrs06-s0-164.pdf, (2007)    2007

  • The High Precision Gamma-Ray Spectrometer for Lunar Polar Orbiter SELENE

    N. Hasebe, N. Yamashita, O. Okudaira, S. Kobayashi, H. Yamamoto, T. Ishizaki, K. Hirano, K. Sakurai, T. Miyachi, M. Miyajima, M. Fuji, M. -N. Kobayashi, T. Takashima, E. Shibamura, O. Gasnault, S. Maurice, C. d’Uston, R. Reedy, M. Grande

    J. Aeronautics (宇航学報) 28(2007)   J. Aeronautics (宇航学報) 28(2007)   159 - 165  2007

  • High performance solid-state track detector for the observation of trans-iron isotopes in galactic cosmic rays

    N.Hasebe, T.Doke, M.Hareyama, S.Kodaira, T.Miyachi, M.Miyajima, O.Okudaira, K.Sakurai, M.Takano, S.Torii, N.Yamashita, N.Yasuda, H.Tawara, S.Nakamura, K.Ogura, H.Shibuya

    http://www.lip.pt/events/2006/ecrs/proc/ecrs06-s0-167.pdf, (2007)   http://www.lip.pt/events/2006/  2007

  • Development of a pinhole camera for X-ray with gaseous xenon ,

    M. Miyajima, M. Mimura, S. Nagasaki, S. Kobayashi, C. Tezuka, N. Hasebe, T. Miyachi, E. Shibamura, A. Ishizuka

    Proc. of Workshop on Ionization and Scintillation Counters and Their Uses(2007)     85 - 89  2007

  • Development of High-pressure Xenon Time Projection Chamber for Planetary Remote Sensing

    M. Mimura, N. Hasebe, M. Miyajima, T. Doke, T. Miyachi, S. Kobayashi, C. Tezuka, E. Shibamura, A. Ishizuka

    Proc. of Workshop on Ionization and Scintillation Counters and Their Uses(2007)     85 - 89  2007

  • Density effects on the electron transport coefficients in Xe gas

    S. Kobayashi, C. Tezuka, T. Doke, N. Hasebe, M. Mimura, M. Miyajima, T. Miyachi, E. Shibamura

    Proc. of Workshop on Ionization and Scintillation Counters and Their Uses(2007)     16 - 20  2007

  • Acoustic signals generated in piezoelectric lead-zirconate-titanate elements by direct bombardment with xenon ions

    T. Miyachi, Y. Nakamura, G. Kuraza, M. Fujii, A. Nagashima, N. Hasebe, M. N. Kobayashi, S. Kobayashi, M. Miyajima, K. Mori, O. Okudaira, N. Yamashita, H. Shibata, T. Murakami, Y. Uchihori, N. Okada

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   568 ( 2 ) 760 - 766  2006.12

     View Summary

    Acoustic signals were observed with a lead-zirconate-titanate (PZT) element. that was directly irradiated with a 368 MeV/n xenon beam. Using an array comprising PZT elements, the energy loss in the PZT was studied. These elements are sensitive to an energy deposit of 100 nJ. A series of values of output voltage vs. integrated thickness of PZT was represented along a line similar to the ionization loss calculated by the Bethe-Bloch formula. The induced voltage was attributed to several processes-ionization, thermal, elastic, and piezoelectric processes. This study describes the possible applications of the PZT element as an active medium for calorimeters and a monitor for hypervelocity impact of space dust. (c) 2006 Elsevier B.V. All rights reserved.

    DOI

  • Ratio of transverse diffusion coefficient to mobility of electrons in high-pressure xenon and xenon doped with hydrogen

    Shingo Kobayashi, Nobuyuki Hasebe, Takehiro Hosojima, Takeshi Ishizaki, Kazuhiro Iwamatsu, Mitsuteru Mimura, Takashi Miyachi, Mitsuhiro Miyajima, Kirill Pushkin, Chikara Tezuka, Tadayoshi Doke, Masanori Kobayashi, Eido Shibamura, Akihiro Ishizuka

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS   45 ( 10A ) 7894 - 7900  2006.10

     View Summary

    We have obtained the ratio of the transverse diffusion coefficient to the mobility of electrons multiplied by the elementary charge, in Xe and Xe + H-2 under electric fields at a higher pressure of 1 MPa in comparison with those in preceding experiments. The results show that the density effect (nonlinear effect) of the ratio in both pure Xe and Xe + H-2 is <= 15% below 1 MPa over the reduced electric field range from 0.08 to 0.6 x 10(-17) V cm(2). We also found that the diffusion of an electron swarm is suppressed by adding trace amount of hydrogen to high-pressure xenon gas. We discuss the application of Xe + H-2 gas to a new gamma-ray camera.

    DOI

  • A scintillation response and an ionization yield in pure xenon and mixtures of it with methane

    K. N. Pushkin, N. Hasebe, C. Tezuka, S. Kobayashi, M. Mimura, T. Hosojima, T. Doke, M. Miyajima, T. Miyachi, E. Shibamura, V. V. Dmitrenko, S. E. Ulin

    INSTRUMENTS AND EXPERIMENTAL TECHNIQUES   49 ( 4 ) 489 - 493  2006.07

     View Summary

    The scintillation response to an alpha source (Am-241) and the ionization yield in pure gaseous xenon and its mixtures with 0.2-2% of methane were measured at a pressure of 26 atm and different values of reduced electric field E/N. Both light and ionization yields in xenon were shown to decrease with increasing percentage of methane.

    DOI

  • Energy spectra of prompt gamma rays from Al and Fe thick targets irradiated by helium and proton beams: Concerning planetary gamma-ray spectroscopy

    Naoyuki Yamashita, Nobuyuki Hasebe, Takashi Miyachi, Mitsuhirc Miyajima, Kunitomo Sakurai, Masanori Kobayashi, Osamu Okudaira, Hiroyuki Yamamoto, Eido Shibamura, Yukio Uchihori, Masayuki Kase

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   75 ( 5 )  2006.05

     View Summary

    Bombardment experiments with thick targets made of each of Al and Fe were performed using 230 MeV/nucleon helium and 210 MeV proton beams. The energies and intensities of prompt gamma rays emitted by inelastic nuclear scattering of energetic neutrons were measured by a high-purity Ge detector. This work presents the first experimental results concerning the emission of prompt gamma rays from thick targets anticipated by helium component in galactic cosmic rays, since no foregoing work related to this one has been done. It is concluded that helium has the capability of prompt gamma ray line emission through the inelastic nuclear reaction of neutrons with target material by a factor of 3.5 on average in comparison with proton. As regards the lunar and planetary nuclear spectroscopy, a consideration is given on the role of helium particles to the total production of gamma rays emitted from a planetary surface.

    DOI

  • Response of acoustic signals generated in water by energetic xenon ions

    T. Miyachi, Y. Nakamura, G. Kuraza, M. Fujii, A. Nagashima, N. Hasebe, M. N. Kobayashi, S. Kobayashi, M. Miyajima, O. Okudaira, N. Yamashita, H. Shibata, T. Murakami, Y. Uchihori, N. Okada, T. Tou

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   560 ( 2 ) 606 - 612  2006.05

     View Summary

    The acoustic signals generated by bombarding 400 MeV/n xenon ions in water were studied using an array of piezoelectric lead-zirconate-titanate elements. The observed signal was reduced to a bipolar form through Fourier analysis. The output voltage corresponded to the amount of energy deposit in water, and it tailed off beyond the range of 400 MeV/n xenon in water. This magnitude was explained qualitatively as cumulative processes. Its behavior was consistent with the calculations based on the Bethe-Bloch formula. Possible applications of this detector to radiology and heavily doped radiation detectors are described. (c) 2006 Elsevier B.V. All rights reserved.

    DOI

  • Study on the sensitivity of BP-1 glass track-etch detector and its production method

    Space Radiation   5 ( 1 ) 87 - 95  2006.03

  • Ultra-Heavy Cosmic Ray Observation for Nuclear Astrophysics

    Space Radiation   5 ( 1 ) 3 - 37  2006.03

  • CR-39/DAP共重合体のDAP混合比と粒子検出閾値について

    小倉 紘一, 小平 聡, 浅枝 真行, 道家 忠義, 長谷部 信行, 晴山 慎, 安田 仲宏, 鶴田 隆雄, 郡 佳伸

    宇宙放射線   5 ( 1 ) 77 - 86  2006  [Refereed]

  • Observation program of isotope composition in the ultra heavy cosmic rays

    N. Hasebe, M. Hareyama, S. Kodaira, K. Sakurai

    Astroparticle, particle and Space Physics, Detectors and Medical Physics Applications, Proc.the 9th Conf., Ed. Michele Barone et al., World Scientific   2006 ( 223 )  2006

  • CALET UPPER LIMITS ON X-RAY AND GAMMA-RAY COUNTERPARTS OF GW151226

    O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzi, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, A. Javaid, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, H. Kitamura, H. S. Krawczynski, J. F. Krizmanic, S. Kuramata, T. Lomtadze, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, F. Palma, P. Papini, A. V. Penacchioni, B. F. Rauch, S. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tsunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda

    Astrophysical Journal, 829L, 20A, (2016).   20A  2006

  • Radiation detector based on acoustic methods using piezoelectric PZT elements

    M. Fujii, G. Kuraza, Y. Nakamura, A. Nagashima, N. Hasebe, M. Kobayashi, S. Kobayashi, T. Miyachi, M. Miyajima, N. Yamashita, H. Shibata, T. Murayama, Y. Uchihori, N. Okada, T. Tou

    Proc. of the 20th Workshop on Radiation Detectors and Their Uses, (2006) 206-216.     206 - 216  2006

  • The origin of helium-3 isotope enhancement in the magnetosphere observed by TSUBASA satellite

    M. Hareyama, M. Fujii, N. Hasebe, N. Kajiwara, S. Kodaira, M. Takano, K. Sakurai, T. Goka, H. Koshoishi, H. Matsumoto

    Astroparticle, particle and Space Physics, Detectors and Medical Pytsics Applications, Proc. the 9th Conf., Ed. Michele Barone et al., World Scientific, (2006)     940  2006

  • Spatial distribution of energetic heavy ions near the earth

    M. Hareyama, N. Hasebe, K. Sakurai, S. Kodaira, N. Kajiwara, M. Takano, T. Doke, M. Fujii, T. Goka, H. Koshoishi, H. Matsumoto, T.Yanagimati

    Astroparticle, particle and Space Physics, Detectors and Medical Physics Applications, Proc. the 9th Conf., Ed. Michele Barone et al., World Scientific (2006)     212  2006

  • Simulation toward Development of A New Gamma-ray Imaging Spectrometer

    M. Mimura, N. Hasebe, M. Hareyama, T. Hosojima, T. Ishizaki, S. Kobayashi, T. Miyachi, M. Miyajima, O. Okudaira, K. Sakurai, C. Tezuka, N. Yamashita, T. Doke, M, N. Kobayashi, A. Ishizuka, E. Shibamura

    Proc. of the 25th Inter. Symp. on Space Tech. and Sci., June 4-11, (2006)   June 4-11   1009 - 1013  2006

  • Petrologic mapping of the Moon using Fe, Mg, and Al abundances

    AA Berezhnoy, N Hasebe, M Kobayashi, G Michael, N Yamashita

    MOON AND NEAR-EARTH OBJECTS   37 ( 1 ) 45 - 49  2006

     View Summary

    A comparison between the abundances of major elements on the Moon determined by Lunar Prospector gamma ray spectrometer and those in returned lunar samples is performed. Lunar Prospector shows higher Mg and Al content and lower Si content in western maria in comparison with the lunar sample collection. Lunar Prospector overestimated the Mg content by about 20%. There are no elemental anomalies at the lunar poles: this is additional evidence for the presence of polar lunar hydrogen. Using Mg, Fe, and Al abundances, petrologic maps containing information about the abundances of ferroan anorthosites, mare basalts, and Mg-rich rocks are derived. This approach is useful for searching for cryptomaria and Mg-rich rocks deposits on the lunar surface. A search is implemented for rare rock types (dunites and pyroclastic deposits). Ca-rich, Al-low small-area anomalies are detected in the far side highlands. (C) 2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • Lander and rover exploration on the lunar surface: A study for SELENE-B mission

    T Okada, S Sasaki, T Sugihara, K Saiki, H Akiyama, M Ohtake, H Takeda, N Hasebe, M Kobayashi, J Haruyama, K Shirai, M Kato, T Kubota, Y Kunii, Y Kuroda

    MOON AND NEAR-EARTH OBJECTS   37 ( 1 ) 88 - 92  2006

     View Summary

    The SELENE-B, a lunar landing mission, has been studied in Japan, where a scientific investigation plan is proposed using a robotic rover and a static lander. The main theme to be investigated is to clarify the lunar origin and evolution, especially for early crustal formation process probably from the ancient magma ocean. The highest priority is placed on a direct in situ geology at a crater central peak, "a window to the interior", where subcrustal materials are exposed and directly accessed without drilling. As a preliminary study was introduced by Sasaki et al. [Sasaki, S., Kubota, T., Okada, T. et al, Scientific exploration of lunar surface using a rover in Japanse future lunar mission. Adv. Space Res. 30, 1921-1926, 2002.], the rover and lander are jointly used, where detailed analyses of the samples collected by the rover are conducted at the lander. Primary scientific instruments are a multi-band stereo imager, a gamma-ray spectrometer, and a sampling tool on the rover, and a multi-spectral telescopic imager, a sampling system, and a sample analysis package with an X-ray spectrometer/diffractometer, a multi-band microscope as well as a sample cleaning and grinding device on the lander. (C) 2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • High performance particle detection system for trans iron isotopes in galactic cosmic rays

    Satoshi Kodaira, Nobuyuki Hasebe, Tadayoshi Doke, Makoto Hareyama, Kunitomo Sakurai, Masayuki Asaeda, Shuya Ota, Nakahiro Yasuda, Hiroko Tawara, Koichi Ogura

    THIRD 21COE SYMPOSIUM: ASTROPHYSICS AS INTERDISCIPLINARY SCIENCE   31   221 - +  2006

     View Summary

    The isotope identification with the solid-state track detector (SSTD) newly developed for the observation of heavy cosmic ray particles was performed using Fe-56 and Fe-55 ions with 460 MeV/nucleon. Mass resolution for iron isotope was thus improved to similar to 0.20 amu in rms. The high speed automatic system of microscope analyzer was also developed to scan and analyze tracks formed by heavy ions in SSTD. The combination of isotope telescope consisting of SSTD with the high speed scanning system enables us to realize a large-scaled observation for trans-iron galactic cosmic rays (GCRs).

    DOI

  • Electron transport property in xenon: Drift velocity, Characteristic energy and Longitudinal diffusion coefficient

    S. Kobayashi, T. Doke, N. Hasebe, T. Hosojima, M. Mimura, M. Miyajima, T. Miyachi, C. Tezuka, E. Shibamura, M, N. Kobayashi

    Proc. of the 20th Workshop on Radiation Detectors and Their Uses, (2006)     197 - 205  2006

  • Development of a low energy gamma-ray pinhole camera

    M. Mimura, O. Okudaira, S. Kobayashi, C. Tezuka, N. Hasebe, T. Hosojima, M. Miyajima, T. Miyachi, N. Yamashita, E. Shibamura, A. Ishizuka

    Proc. of the 20th Workshop on Radiation Detectors and Their Uses, (2006)     112 - 120  2006

  • Astroparticle, particle and Space Physics, Detectors and Medical Physics Applications

    N. Hasebe, M. Hareyama, S. Kodaira, K. Sakurai, Observation program of isotope, co, ra, heavy cosmic rays

    Proc.the 9th Conf., Ed. Michele Barone et al., World Scientific (2006)     223  2006

  • Astroparticle, particle and Space Physics, Detectors and Medical Physics Applications

    N. Hasebe, M. Hareyama, S. Kodaira, K. Sakurai, Observation program of isotope, co, ra, heavy cosmic rays

    Concerning Planetary Gamma-Ray Spectroscopy", J. Phys. Soc. Jpn. 75 (2006)   75   54201  2006

  • A new generation gamma-ray camera for planetary science applications: High pressure xenon time projection chamber

    S Kobayashi, N Hasebe, T Hosojima, T Igarashi, MN Kobayashi, M Mimura, T Miyachi, M Miyajima, KN Pushkin, H Sakaba, C Tezuka, T Doke, E Shibamura

    MOON AND NEAR-EARTH OBJECTS   37 ( 1 ) 28 - 33  2006

     View Summary

    A new gamma-ray imaging camera based on High-pressure Xe Time-Projection-Chamber (HPXe-TPC) allows us to simultaneously determine arrival direction and its energy of individual incident gamma rays. HPXe-TPC is a promising y-ray detector for planetary science which provides means of global mapping of elemental composition in planetary surface as the remote sensing spectrometer. The simulation study by Geant4 and numerical calculation show that the angular resolution is mostly affected by multiple scattering of the recoil electron, and position resolution of electrodes of TPC. It is found that the angular resolution is 9 degrees (50%) at 2 MeV for gamma rays. The feasibility of HPXe-TPC is discussed as a y-ray imaging camera for future planetary mission. (C) 2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • A next generation gamma-ray camera for imaging of planetary surfaces

    S. Kobayashi, N. Hasebe, T. Hosojima, M. Mimura, T. Miyachi, M. Miyajima, C. Tezuka, T. Doke, E. Shibamura

    THIRD 21COE SYMPOSIUM: ASTROPHYSICS AS INTERDISCIPLINARY SCIENCE   31   199 - +  2006

     View Summary

    We summarize the present R&D status of high-pressure xenon time projection chamber (HPXe-TPC) which is a new gamma-ray camera for planetary science mission.

    DOI

  • Comparison of trapped particle intensities in SAA region observed by two Japanese satellites, USERS and SERVIS-1

    M.Hareyama, M.Fujii, N.Hasebe, S.Kodaira, Y.Mita, K.Sakurai, M.Akiyama, K.Ichiji, K.Hama

    http://www.lip.pt/events/2006/ecrs/proc/ecrs06-s1-94.pdf,    2006

  • The attenuation length of cosmic ray iron in the atmosphere obtained by TIGER experiment

    S Kodaira, M Hareyama, N Hasebe, T Miyachi, K Sakurai, WR Binns, Cummings, JR, MH Israel, JT Link, BF Rauch, LM Scott, S Geier, RA Mewaldt, LM Barbier, JW Mitchell, GA De Nolfo, RE Streitmatter, CJ Waddington

    INTERNATIONAL JOURNAL OF MODERN PHYSICS A   20 ( 29 ) 6702 - 6704  2005.11

     View Summary

    A precise measurement of elemental abundances of galactic cosmic rays from charges Z = 20 to 34 was made by TIGER balloon experiment. Using the various path lengths in the atmosphere between 4 and 16 g/cm(2) from the TIGER flight data, we derived the attenuation length of iron nuclei with the energy above 2.5 GeV/n in the atmosphere. As the result, we obtained the attenuation length of 15.5 +/- 0.6 g/cm(2) which is consistent with previous results of balloon measurements.

    DOI

  • Helium isotopes in the radiation belts obtained by HIT onboard TSUBASA

    M Hareyama, M Asaeda, M Fujii, N Hasebe, N Kajiwara, MN Kobayashi, S Kodaira, K Sakurai, T Goka, H Koshishi, H Matsumoto

    INTERNATIONAL JOURNAL OF MODERN PHYSICS A   20 ( 29 ) 6687 - 6689  2005.11

     View Summary

    The helium isotopes were observed by Heavy Ion Telescope (HIT) onboard the TSUBASA satellite from March, 2002 to September, 2003 in the geostationary transfer orbit The mass resolution of the HIT instrument is similar to 0.25 amu in energy range 20 divided by 43 MeV/nucleon for helium isotopes. Helium data in the quiet periods were analyzed to obtain the spatial and temporal variation of fluxes of helium isotopes, He-3 and He-4. From this analysis, the enhancement of He-3 flux as compared with He-4 one in low L-value was found. Both of the helium fluxes strongly fluctuated in their L-distributions in each period.

    DOI

  • A three end-member model for petrologic analysis of lunar prospector gamma-ray spectrometer data

    AA Berezhnoy, N Hasebe, M Kobayashi, GG Michael, O Okudaira, N Yamashita

    PLANETARY AND SPACE SCIENCE   53 ( 11 ) 1097 - 1108  2005.09

     View Summary

    We analyze preliminary Lunar Prospector gamma-ray spectrometer data. Al-Mg and Fe-Mg petrologic maps of the Moon show that Mg-rich rocks are located in Mare Frigoris, the South Pole Aitken basin, and in some cryptomaria. Analysis of distances of Lunar Prospector pixels from three end-member plane in Mg-Al-Fe space reveals existence of Ca-rich, Al-low small-area anomalies in the farside highlands. An Mg-Th-Fe petrologic technique can be used for estimation of abundances of ferroan anorthosites, mare basalts, KREEP basalts, and Mg-rich rocks. (c) 2005 Elsevier Ltd. All rights reserved.

    DOI

  • Delta E x E silicon telescope of energetic heavy ions trapped in radiation belts

    H Matsumoto, H Koshiishi, T Goka, M Funjii, M Hareyama, N Kajiwara, S Kodaira, K Sakurai, N Hasebe

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS   44 ( 9A ) 6870 - 6872  2005.09

     View Summary

    Heavy Ion Telescope (HIT) is an instrument onboard the Japanese satellite "TSUBASA", which was launched in February 2002 for the observation of heavy ions in radiation belts. The HIT instrument, based on the Delta E x E particle identification method, consists of two position-sensitive silicon detectors and 16 PIN-type Si detectors with 420 mu m in thickness. The geometric factor varies from 12 to 18 cm(2) sr being dependent on the energy of ions. This instrument was designed to measure the fluxes of heavy ions from He to Fe nuclei in the energy range from 18 to 179 MeV/n, though dependent on the nuclear species to be measured. The nuclear charge separation in this instrument was highly sophisticated as 0.06 charge units for nuclei such as C and 0, for instances, in observing energetic ions from He to Fe. Furthermore, isotopic separation was sufficient for the observations of nuclei such as He, Ne, Mg and Si. The observation of energetic ions in radiation belts was successfully achieved during both quiet and disturbed periods of solar activity. The detector system and observational results of ions in the radiation belts are described as the performance of the HIT instrument in space.

    DOI

  • Germanium detector with Stirling cryocooler for lunar gamma-ray spectroscopy

    M Kobayashi, N Hasebe, T Hiramoto, T Miyachi, S Murasawa, H Okada, O Okudaira, N Yamashita, AA Berezhnoy, E Shibamura, T Takashima, C d'Uston, K Narasaki, K Tsurumi, H Kaneko, M Nakazawa, K Mori, M Fujii

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   548 ( 3 ) 401 - 410  2005.08

     View Summary

    The gamma-ray spectrometer (GRS) of Japanese lunar polar orbiter SELENE uses a Ge detector for the first time on a lunar mission. This spectrometer will observe lunar gamma rays for I year or more to determine chemical composition over the entire lunar surface. For cooling the Ge detector, we adopted a Stirling cryocooler. The SELENE GRS flight model was completed and an energy resolution of 3.0 keV (FWHM) at 1.33 MeV was achieved. This paper describes the details of the detector-cryogenic system and its performance. (c) 2005 Elsevier B.V. All rights reserved.

    DOI

  • Response from piezoelectric elements appearing immediately after collisions with silver particles

    T Miyachi, M Fujii, N Hasebe, M Kobayashi, G Kuraza, A Nagashima, Y Nakamura, O Okudaira, N Yamashita, K Nogami, T Iwai, S Sasaki, H Ohashi, S Hasegawa, H Yano, H Shibata, N Okada, T Tou

    JOURNAL OF APPLIED PHYSICS   98 ( 1 ) 0141101 - 0141107  2005.07

     View Summary

    Ferroelectric lead zirconate titanate (PZT) elements were studied by directly bombarding them with hypervelocity silver particles. The mass and velocity of these hypervelocity silver particles ranged from 1 to 80 pg and 2 to 6 km/s, respectively. This report examines the pulsed signals observed immediately after collision. The first cycle of the pulse is discussed because the information on impact is presumably recorded on the wave form. The experimental data were analyzed using the wave form that was generated immediately after collision. Consequently, the following conclusions were made: (1) the sensitivity of the element is independent of the thickness of element, (2) the pulse height is proportional to the particle momentum over the measured range, and (3) the wave form is not explicitly related to the velocity of the particles at the time of collision. The potential of a single PZT element acts as a real-time detector for hypervelocity microparticles is discussed. (c) 2005 American Institute of Physics.

    DOI

  • Are galactic cosmic rays accelerated inside the ejectae expanding just after supernova explosions

    N Hasebe, M Hareyama, S Kodaira, K Sakurai

    NUCLEAR PHYSICS A   758   292C - 295C  2005.07

     View Summary

    Referring to the observed results on the source composition of galactic cosmic rays, a possible mechanism for the formation of this composition is proposed by taking into account the fractionation of elements in dust grains formed in the interstellar molecular clouds. These dust grains become enriched with the elements whose condensation temperature is higher than about 1000K. Most of these nuclei enhanced in the source composition axe identified as heavy and ultra-heavy ones, which must have been synthesized in the r-process initiated with the explosions of type II supernovae in the OB-association. The dust grains in the superbubble are later ionized and then accelerated through their interactions with shock waves of supershell formed from multiple explosions of nearby supernovae. This may mean that cosmic rays axe significantly generated from the dust grains drifting in the local interstellar space.

    DOI

  • Velocity-dependent wave forms of piezoelectric elements undergoing collisions with iron particles having velocities ranging from 5 to 63 km/s

    T Miyachi, M Fujii, N Hasebe, MN Kobayashi, G Kuraza, A Nagashima, Y Nakamura, K Nogami, T Iwai, S Sasaki, K Muranaga, H Ohashi, S Hasegawa, H Yano, H Shibata, E Grun, R Srama, N Okada, T Tou

    APPLIED PHYSICS LETTERS   86 ( 23 ) 234102  2005.06

     View Summary

    A response from piezoelectric lead-zirconate-titanate elements was investigated by bombarding them with hypervelocity iron particles. The observed signal form was clearly dependent on the particle velocity during collisions. The signal form exhibited oscillations for particle velocities less than 6 km/s, whereas it changed drastically into a solitary pulse above 20 km/s. This behavior was exclusively classified based on the velocity. The rise time of the solitary pulse in the output form had a good correlation with the velocity at impact. The change in the form was discussed in terms of elastic and plastic states by regarding Young's modulus as a criterion between both states. It is proposed that a single piezoelectric element has the potential to detect the velocity of particles in space. (c) 2005 American Institute of Physics.

    DOI

  • ACE/NOZOMI multispacecraft observations of solar energetic particles

    H. Miyasaka, E. C. Stone, R. A. Mewaldt, G. M. Mason, D. K. Haggerty, K. Nagata, J. Kikuchi, T. Doke, N. Hasebe, K. Maezawa, T. Takashima, A. Ihara, A. Matsuoka

    Proceedings of the 29th International Cosmic Ray Conference Vol 1: SH1 and SH2     315 - 318  2005  [Refereed]

  • Empirical formulas for hypervelocity impact with a piezoelectric element and their application to a new real-time dust detector

    T. Miyachi, M. Fujii, N. Hasebe, G. Kuraza, K. Nogami, T. Iwai, S. Sasaki, H. Ohashi, S. Hasegawa, H. Yano, H. Shibata, E. Gruen, R. Srama, N. Okada, T. Toru

    2005 IEEE Nuclear Science Symposium Conference Record, Vols 1-5   1   423 - 427  2005  [Refereed]

     View Summary

    Hypervelocity collisions of microparticles with a lead-zirconate-titanate piezoelectric element are examined. The waveforms thus obtained depend on the velocities during collision, and are classified into three categories. In particular, the first cycle of the signal observed immediately after collision is essential to obtain information on the impact. In each category, experimental formulas that are functions of the impact velocity are established based on experimental data. It is concluded that a single piezoelectric element can potentially measure the velocity and/or momentum of hypervelocity microparticles in real time. In the abovementioned context, the new dust detectors are described.

    DOI

  • Velocity dependent response of a piezoelectric element to hypervelocity microparticles

    T Miyachi, M Fujii, N Hasebe, MN Kobayashi, G Kuraza, A Nagashima, Y Nakamura, K Nogami, T Iwai, S Sasaki, H Ohashi, S Hasegawa, H Yano, H Shibata

    SPACE DEBRIS   35 ( 7 ) 1263 - 1269  2005

     View Summary

    Piezoelectric lead-zirconate-titanate (PZT) elements were Studied by directly bombarding hypervelocity silver and iron particles in the velocity range of 2-63 km/s. This report focuses on the concept of "immediately after collision". This concept was realized in the leading part of a pulsed signal that exhibited no effects due to reflection. The signal form was discussed from the viewpoint that information on impact was recorded by the waveform. The results indicated that the output amplitude was independent of the thickness of a PZT element, and that the waveform was explicitly related to the velocity at collision. Further, it appeared as an oscillating form at velocities less than 6 km/s. As the velocity increased, it gradually changed to a solitary pulse. The rise time of the single solitary waveform was linearly related to velocities above 6 km/s. The potential of a single PZT element is discussed as a real-time detector for hypervelocity microparticles. (c) 2005 Published by Elsevier Ltd on behalf of COSPAR.

    DOI

  • Next generation gamma-ray imager for planetary science mission

    T. Hosojima, N. Hasebe, T. Kimura, M, ?N. Kobayashi, S. Kobayashi, M. Mimura, T. Miyachi, M. Miyajima, O. Okudaira, K. Pushkin, C. Tezuka, N. Yamashita

    Proc. of the 19th Workshop on Radiation Detectors and Their Uses, 2005-12(2005)   2005-12   119 - 208  2005

  • Mass resolution for iron isotopes in CR-39 track detector

    S Kodaira, N Hasebe, T Doke, A Kitagawa, H Kitamura, S Sato, Y Uchihori, N Yasuda, K Ogura, H Tawara

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   43 ( 9A ) 6358 - 6363  2004.09

     View Summary

    We have verified the capability of a CR-39 track detector for isotope identification using iron beam from the heavy-ion accelerator of HIMAC at NIRS. The same CR-39 stack was independently exposed to Fe-56 and Fe-55 ions with an energy of 460 MeV/nucleon. Mass resolutions for Fe-56 and Fe-55 ions were determined to be 0.28 +/- 0.12 amu and 0.28 +/- 0.11 amu in rms, respectively. A detailed analysis of the sources of the mass dispersion in the present mass identification experiment showed that significant errors were caused in the measurements of the surface position and the thickness of CR-39 sheets. By eliminating these errors as much as possible, the mass resolution is expected to be improved to similar to0.20 amu.

    DOI

  • Scintillation luminescence for high-pressure xenon gas

    S Kobayashi, N Hasebe, T Igarashi, MN Kobayashi, T Miyachi, M Miyajima, H Okada, O Okudaira, C Tezuka, E Yokoyama, T Doke, E Shibamura, VV Dmitrenko, SE Ulin, KF Vlasik

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   531 ( 1-2 ) 327 - 332  2004.09

     View Summary

    Scintillation and ionization yields in xenon gas for 5.49 MeV alpha-particles were measured in the range of pressure from 0.35 to 3.7 MPa and the electric field strength (E) over the number density of xenon atoms (N), E/N from 0 to 5 x 10(-18) V cm(2). When our data are normalized at the data point measured by Saito et a]., the number of scintillation photons is 2.3 x 10(5) while the number of ionization electrons is 2.0 x 10(5) at 2.6 MPa and at 3.7 x 10(-18) V cm(2). The scintillation and ionization yields of xenon doped with 0.2% hydrogen, High-Pressure Xenon gas[H-2-0.2%], at 2.6 MPa was also measured. Scintillation yield of the Xe-H-2 mixture gas is 80% as high as that of pure xenon. It is found that the scintillation yield is luminous enough to generate a trigger pulse of the high-pressure xenon time projection chamber, which is expected as a promising MeV Compton gamma-ray camera. (C) 2004 Elsevier B.V. All rights reserved.

    DOI

  • Ratio of transverse diffusion coefficient to mobility of electrons in high-pressure xenon

    S Kobayashi, N Hasebe, T Igarashi, T Miyachi, M Miyajima, H Okada, T Doke, E Shibamura, VV Dmitrenko, KF Vlasik

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   43 ( 8A ) 5568 - 5572  2004.08

     View Summary

    We constructed a parallel plate drift chamber for measuring the ratio of the transverse diffusion coefficient D, to the mobility It of electrons multiplied by the elementary charge e, eD(t)/mu, which is called the transverse characteristic energy, in high-pressure xenon gas. The characteristic energies of electrons in Xe were obtained at a high pressure of 1.0MPa and the reduced electric field, E/N, from 0.77 to 7.7 x 10(-18) V-cm 2, where E denotes an electric field and N the number density of Xe atoms. At the same E/N, our results agreed well with the data at pressures from 107 to 193 kPa previously obtained by Koizumi et al. [J. Phys. B 19 (1986) 2331]. The characteristic energies of electrons in Xe were found to be constant as a function of E/N from a low pressure to 1.0 MPa.

    DOI

  • Electron diffusion and scintillation in xenon doped with hydrogen for high-pressure xenon time projection chamber

    C Tezuka, N Hasebe, S Kobayashi, T Igarashi, M Mimura, T Hosojima, MN Kobayashi, T Doke, M Miyajima, T Miyach, H Okada, E Shibamura, KN Pushkin, SE Ulin

    2004 IEEE Nuclear Science Symposium Conference Record, Vols 1-7     1157 - 1159  2004  [Refereed]

     View Summary

    High-pressure xenon time projection chamber (HPXe-TPC) is a sophisticated detector, which can determine not only an energy of gamma ray but also its arrival direction by using Compton scattering. Diffusion of electrons and scintillation yield in Xe and Xe+H-2 mixture have been investigated to realize a HPXe-TPC. The transverse characteristic energy of electrons in Xe+H-2 mixture (H-2 0.44%) was reduced to about 40% against that of pure Xe at 1.0 MPa. Scintillation yields by alpha-particles (Am-241) in Xe+H-2 mixture (H-2 0.23 similar to 5.7%) at 2.6 MPa were obtained as a function of E/N. The scintillation yields in Xe+H-2 mixture at 2.6 MPa and at E/N =0.3 x 10(-17) Vcm(2) were luminous enough to generate a trigger signal of a HPXe-TPC. It is found that doping hydrogen into xenon is effective to prevent the degradation of angular resolution of a HPXe-TPC.

  • Scintillation yield in high pressure xenon and xenon doped with methane

    KN Pushkin, N Hasebe, S Kobayashi, C Tezuka, M Mimura, T Hosojima, MN Kobayashi, T Doke, M Miyajima, T Miyachi, E Shibamura, SE Ulin, VV Dmitrenko

    2004 IEEE Nuclear Science Symposium Conference Record, Vols 1-7     550 - 553  2004  [Refereed]

     View Summary

    Scintillation light and ionization yields in pure xenon and xenon doped with various concentration of methane (0.2-2%) have been measured as a function of the reduced electric field (E/N) from 0 to 4x10(-18)Vcm(2) at a pressure of 2.6 MPa. The measurements of photons and electrons have been made in gaseous xenon excited by Am-241 alpha particles. High purity xenon was used to fill a high-pressure xenon chamber equipped with MgF2 window coupled to a photomultiplier tube (PMT). The scintillation light in xenon-methane mixture is observed to decrease as the concentration of methane increases.

  • Real-time detector for hypervelocity microparticles using piezoelectric material

    T Miyachi, N Hasebe, H Ito, T Masumura, H Okada, H Yoshioka, K Nogami, T Iwai, H Shibata, Y Hamabe, S Sasaki, S Sugita, S Hasegawa, H Yano, H Ohashi, K Muranaga, M Sato, T Tou

    SPACE DEBRIS   34 ( 5 ) 935 - 938  2004

     View Summary

    Piezoelectric lead-zirconate-titanate was studied by bombarding with silver particles in the mass range from 2 to 100 pg, and the velocity range from 2 to 8 km/s. Output signals were uniquely identified on impact. It was found that incident energies above 100 nJ were measured unambiguously by a single lead-zirconate-titanate element. The detector characteristics were studied with respect to incident particle energy, angular dependence and size effects. Even though we have still unknown processes inherent in this detection method, the piezoelectric element has a potential as a real-time detector, if it is well calibrated. (C) 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • Radio observations of the Moon during Leonid meteor showers in 1999 and 2001

    AA Berezhnoy, N Hasebe, A Fujimura, OB Khavroshkin, H Mizutani, H Osaki, AE Volvach, N Yamashita

    BALTIC ASTRONOMY   13 ( 4 ) 601 - 605  2004

     View Summary

    Results of observations of the Moon at 3.6 cm at Kashima (Japan) and at 6.2 cm and 3.56 cm at Simeiz (Ukraine) are presented. There is no evidence of the influence of the Leonid meteor shower on the lunar radio flux. The search for impact-produced radio flashes was also unsuccessful. Future study of seismic activity of the Moon by Lunar-A and Selene spacecrafts is discussed.

  • Response of piezoelectric lead-zirconate-titanate to hypervelocity silver particles

    T Miyachi, N Hasebe, H Ito, T Masumura, H Okada, H Yoshioka, M Higuchi, T Matsuyama, K Nogami, T Iwai, H Shibata, Y Hamabe, S Sasaki, S Sugita, H Ohashi, S Hasegawa, H Yano, M Sato, T Tou

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   42 ( 3 ) 1496 - 1497  2003.03

     View Summary

    A lead-zirconate-titanate (PZT) element was studied by bombarding silver particles in the mass range from I to 100 pg, and the velocity from 2 to 6 km/s. Output signals were uniquely identified on impact and characterized by Fourier analysis. It was found that incident energies above 100 nJ were uniquely determined by a single PZT element. We discussed its potential as a real-time detector for space dust and debris.

    DOI

  • Acoustic response of piezoelectric lead-zirconate-titanate to a 400 MeV/n xenon beam

    T Miyachi, N Hasebe, H Ito, T Masumura, H Okada, O Okudaira, N Yamashita, H Yoshioka, M Higuchi, T Matsuyama, T Murakami, Y Uchihori, M Kase, R Kikuchi, M Sato, T Tou

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS   42 ( 3 ) 1456 - 1457  2003.03

     View Summary

    Characteristics of lead-zirconate-titanate (PZT) elements were studied by directly irradiating them with a 400 MeV/n Xe beam. The elements were sensitive to 10(4) Xe ions and their output amplitudes were proportional to the beam intensity. An ensemble of those output amplitudes displayed a Bragg-curve-like response towards the range of 400 MeV/n Xe ion. We discuss the potential of PZT elements as a radiation detector and their application to high-intensity and high-energy detectors.

    DOI

  • Possibility of the Presence of S, SO2, and CO2 at the Poles of the Moon

    Alexey A. Berezhnoy, Nobuyuki Hasebe, Takuji Hiramoto, Boris A. Klumov

    Publications of the Astronomical Society of Japan   55 ( 4 ) 859 - 870  2003  [Refereed]

     View Summary

    The presence of volatiles near the lunar poles is considered. The chemical composition of a lunar atmosphere temporarily produced by comet impact is analyzed during the day and night. C-rich and long-period comets are insufficient sources of water ice on the Moon. O-rich short-period comets deliver significant amounts of H2O, CO2, SO2, and S to the Moon. An observable amount of polar hydrogen can be delivered to the Moon by a single impact of an O-rich short-period comet with diameter of 5 km in the form of water ice. The areas where CO2 and SO2 ices are stable against a thermal sublimation are estimated to be 300 and 1500 km2, respectively. If water ice exists in the 2cm top regolith layer, CO2 and SO2 ices can be stable in the coldest parts of permanently shaded craters. The delivery rate of elemental sulfur near the poles is estimated to be 106 g yr-1. The sulfur content is estimated to be as high as 1 wt % in the polar regions. The SELENE gamma-ray spectrometer can detect sulfur polar caps on the Moon if the sulfur content is higher than 1 wt %. This instrument can check the presence of hydrogen and minerals with the unusual chemical composition at the lunar poles.

    DOI

  • Study of low-Q PZT as a radiation detector

    T Miyachi, N Hasebe, H Ito, T Masumura, H Yoshioka, N Yamashita, O Okudaira, T Murakami, Y Uchihori, M Sato, T Tou

    2002 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORD, VOLS 1-3     9 - 13  2003  [Refereed]

     View Summary

    Piezoelectric PZT elements were studied by directly irradiating a 400 MeV/n Xe beam. The elements were sensitive to the number of 10(4) Xe ions and their output amplitudes were proportional to the beam intensity, that is, the total energy deposited within the element. An ensemble of the output amplitudes behaved like the Bragg curve towards the end of the range. We discuss its potential as a radiation detector and its application to high intensity and high energy detectors.

  • Measurement of electron drift velocities in the mixture of Xe and He for a new high-pressure Xe gamma-ray detector

    S Kobayashi, VV Dmitrenko, T Doke, VM Grachev, N Hasebe, T Igarashi, T Miyachi, H Okada, E Shibamura, M Takenouchi, SE Ulin, KF Vlasik

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   42 ( 1 ) 333 - 334  2003.01

     View Summary

    Drift velocities of electrons in a mixture of Xe (20 atm)-He (3 atm) were measured using a cylindrical high-pressure xenon chamber. The drift velocities were found to be greater than 3 x 10(5) cm/s above the reduced electric field of 2.0 x 10(-18) V.cm(2) at room temperature, which are close to those in Xe-H-2 (0.3%). The mixture of He gas into high-pressure xenon improved the resolving time of detectors because it increased the electron drift velocities. This implies that a high-pressure xenon chamber mixed with He-3 instead of He gas operates as a gamma-ray detector sensitive to thermal neutrons.

    DOI

  • Measurements and calculations of gamma rays from proton-irradiated thick targets

    N Yamashita, N Hasebe, T Miyachi, E Shibamura, H Okada, O Okudaira, H Sori, T Koike, T Hiramoto, A Nagashima, T Fukuoka, M Kase, Dmitrenko, V, K Vlasik

    MOON: SCIENCE, EXPLORATION AND UTILISATION   31 ( 11 ) 2359 - 2362  2003

     View Summary

    To help understand planetary gamma-ray spectra, the energies and intensities of gamma rays produced by energetic particles interacting in thick targets were simulated experimentally and numerically. Using the accelerator at RIKEN, thick targets of iron, granite, and gabbro were exposed to 180 or 210 MeV proton beam, and characteristic gamma rays emitted from the targets were measured by Ge detectors. The experimental results were compared with the values calculated by Geant4. The relative intensities of gamma-ray lines from the iron target in the experiment were consistent with those in the calculation within the error of similar to5%. As for stone targets, strong inconsistencies were observed. Further improvement in the calculation code and cross section files, as well as experimental resemblance to space missions are indispensable for gamma-ray spectroscopy. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

    DOI

  • Electron and ion spectrometer onboard the Nozomi spacecraft and its initial results in interplanetary space

    A Ihara, T Doke, N Hasebe, J Kikuchi, MN Kobayashi, K Maezawa, K Nagata, T Sakaguchi, T Shino, T Takashima, S Teruhi, B Wilken, T Yanagimachi

    ASTROPARTICLE PHYSICS   17 ( 3 ) 263 - 278  2002.06

     View Summary

    The electron and ion spectrometer (EIS) is one of the fourteen instruments onboard the Nozomi spacecraft, a Mars orbiter, launched on July 4, 1998. EIS consists of two kinds of telescopes (TOF-E and DeltaE-E telescopes) designed to measure the fluxes of electrons and ions in the energy range from similar to40 keV to a few MeV. The DeltaE-E telescopes are used to measure electrons and protons, while the TOF-E telescope is mainly used to measure He, CNO-group, NeMgSi-group, and Fe-group. In this paper, (a) the objectives of this experiment, (b) the details of the instrument and (c) initial results of the observation in interplanetary space are described. (C) 2001 Elsevier Science B.V. All rights reserved.

  • Electron and ion spectrometer onboard the Nozomi spacecraft and its initial results in interplanetary space

    A Ihara, T Doke, N Hasebe, J Kikuchi, MN Kobayashi, K Maezawa, K Nagata, T Sakaguchi, T Shino, T Takashima, S Teruhi, B Wilken, T Yanagimachi

    ASTROPARTICLE PHYSICS   17 ( 3 ) 263 - 278  2002.06

     View Summary

    The electron and ion spectrometer (EIS) is one of the fourteen instruments onboard the Nozomi spacecraft, a Mars orbiter, launched on July 4, 1998. EIS consists of two kinds of telescopes (TOF-E and DeltaE-E telescopes) designed to measure the fluxes of electrons and ions in the energy range from similar to40 keV to a few MeV. The DeltaE-E telescopes are used to measure electrons and protons, while the TOF-E telescope is mainly used to measure He, CNO-group, NeMgSi-group, and Fe-group. In this paper, (a) the objectives of this experiment, (b) the details of the instrument and (c) initial results of the observation in interplanetary space are described. (C) 2001 Elsevier Science B.V. All rights reserved.

    DOI

  • 宇宙線中の超鉄核成分の高精度観測計画

    東大宇宙線研シンポジューム 高エネルギー宇宙の総合的理解-新技術で切り開く宇宙線物理-/東大宇宙線研    2002.03

  • Development of a realtime detector to hypervelocity microparticles using PZT ceramics

    T Miyachi, N Hasebe, H Ito, T Masumura, H Okada, H Yoshioka, K Nogami, T Iwai, H Shibata, Y Hamabe, S Sasaki, S Sugita, A Fujiwara, S Hasegawa, H Yano, Y Honda, M Sato

    2001 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORDS, VOLS 1-4   1   422 - 426  2002

     View Summary

    Detector characteristics of disk-shaped piezoceramic elements were studied by irradiating silver and carbon microparticles. A mass of particles ranged from 0.01 to 100pg, and whose velocity from 2 to 20km/s. We observed characteristic pulse signals when the particles were collided with the element. Carbon projectiles generated a bipolar-type sharp peak, whereas silver projectiles did not show such a distinct form. For silver, the pulse amplitude increased with increasing the particle energy. A possible application to a realtime detector of micrometeoroid and space debris is discussed.

  • Electron and ion spectrometer onboard the Nozomi spacecraft and its initial results in interplanetary space

    A. Ihara, T. Doke, N. Hasebe, J. Kikuchi, M. N. Kobayashi, K. Maezawa, K. Nagata, T. Sakaguchi, T. Shino, T. Takashima, S. Teruhi, B. Wilken, T. Yanagimachi

    Astroparticle Physics   17 ( 3 ) 263 - 278  2002

     View Summary

    The electron and ion spectrometer (EIS) is one of the fourteen instruments onboard the Nozomi spacecraft, a Mars orbiter, launched on July 4, 1998. EIS consists of two kinds of telescopes (TOF E and ΔE E telescopes) designed to measure the fluxes of electrons and ions in the energy range from ∼40 keV to a few MeV. The ΔE-E telescopes are used to measure electrons and protons, while the TOF-E telescope is mainly used to measure He, CNO-group, NeMgSi-group, and Fe-group. In this paper, (a) the objectives of this experiment, (b) the details of the instrument and (c) initial results of the observation in interplanetary space are described. © 2001 Elsevier Science B.V. All rights reserved.

    DOI

  • ピエゾ圧電素子による放射線検出器の開発及び超高速微粒子リアルタイム計測への応用

    宇宙放射線   3,pp.13-27  2002

  • Response of a low-Q PZT detector to hypervelocity microparticles

    T. Miyachi, N. Hasebe, H. Ito, T. Masumura, H. Okada, H. Yoshioka, K. Nogami, Y. Hamabe, T. Iwai, S. Sasaki, H. Shibata, S. Sugita, A. Fujiwara, S. Hasegawa, H. Yano, Y. Honda, M. Sato

    Proc. of the 23rd Inter. Symp. on Space Tech. and Sci.   Proc. of the 23rd Inter. Symp.   1706 - 1710  2002

  • Large Ge Gamma-ray Spectrometer with the Anti-coincidence Subsystem using Scintillators on SELENE Mission

    Scientific Session of MEPhI-2002   7,pp.59-60  2002

  • Large Area PIN-type Silicon Detectors for Measuring Heavy Cosmic Ray Nuclei

    Scientific Session of MEPhI-2002   7,pp.65-66  2002

  • High-purity germanium gamma-ray spectrometer with stirling cycle cryocooler

    MN Kobayashi, N Hasebe, T Miyachi, T Doke, J Kikuchi, H Okada, A Oka, O Okudaira, H Souri, N Yamashita, E Shibamura, T Kashiwagi, T Takashima, K Narasaki, K Tsurumi, K Mori, C d'Uston, S Maurice, M Grande, RC Reedy

    LUNAR EXPLORATION 2000   30 ( 8 ) 1927 - 1931  2002

     View Summary

    The Japanese lunar polar orbiter SELENE carries a gamma-ray spectrometer which uses a high-purity Ge detector cooled to 80-90 K by a Stirling mechanical cooler. The Gamma-Ray Spectrometer (GRS) consists of a large volume n-type Ge detector (252 cc) as the main detector and bismuth-germanate (BGO) and plastic scintillators as an active shielding. The engineering model still maintains excellent energy resolution even after severe vibration testing. The Gamma-Ray Spectrometer will globally map of the Moon for the major elements of O, Mg, Al, Si, Ti, Fe, etc. and natural radioisotopes of K, Th and U with a high precision. The energy resolution of the GRS is such that it would identify prompt gamma-ray line from hydrogen and the location and the amount of ice, if it exists at the polar regions. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

    DOI

  • High Pressure Xenon Gamma-ray Spectrometer for Planetary Remoto Sensing

    Scientific Session of MEPhI-2002   7,pp.61-62  2002

  • Gamma-ray and Neutron Leakage Fluxes as a Function of Composition GEANT4 Simulation and Experiment of Proton Bombardment from RIKEN Ring-Cycloton

    Scientific Session of MEPhI-2002   7,pp.57-58  2002

  • Experimental Studies of Acoustic Signals of High Energy Charged Particles

    Scientific Session of MEPhI-2002   7,pp.70-71  2002

  • Diffusion and Drift of Electrons in High-Pressure Xenon Gas

    Scientific Session of MEPhI-2002   7,pp.53-54  2002

  • Development of a realtime detector for hypervelocity microparticles based on a low-Q PZT material

    T. Miyachi, N. Hasebe, H. Ito, T. Masumura, H. Okada, H. Yoshioka, K. Nogami, T. Iwai, H. Shibata, Y. Hamabe, S. Sasaki, S. Sugita, S. Hasegawa, H. Yano, H. Ohashi, K. Muranaga, M. Sato, T. Tou

    Proceedings of Asteroids, Comets, Meteors (ACM2002), ESA-SP-500   Proceedings of Asteroids, Come   847 - 849  2002

  • Acoustic Measurement of Hypervelocity Microparticles by PZT Devices

    Scientific Session of MEPhI-2002   7,pp.72-73  2002

  • The Development of Large Area Silicon Detector for Heavy Particles

    Technical Report No.2002-2/理工総研   pp.1-8  2002.01

  • Large Area PIN-type Silicon Detectors for Measuring Heavy Cosmic Ray Nuclei

    Scientific Session of MEPhI-2002/モスクワ工科物理学研究所    2002.01

  • Gamma-ray Spectroscopy for Planetary Investigation

    Plenary Session of Scientific Session of MEPhI-2002/モスクワ工科物理学研究所(国立大学)    2002.01

  • Ring current oxygen ions escaping into the magnetosheath

    QG Zong, B Wilken, SY Fu, TA Fritz, A Korth, N Hasebe, J Williams, ZY Pu

    JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS   106 ( A11 ) 25541 - 25556  2001.11

     View Summary

    Storm-related magnetospheric oxygen bursts were observed in the dayside magnetosheath during the coronal mass ejection on January 10, 1997. These singly charged oxygen ion events exhibited a clear antisunward flow. The oxygen ions are associated with a strong negative interplanetary magnetosheath field (IMF). The average B-z was almost - 50 nT, and the field projection in the x - y plane (GSE) was nearly constant in the Sun/dawn sector forming an angle of 45 degrees relative to the Earth-Sun axis. The magnetopause was identified as a rotational discontinuity by using the principal axis analysis (PAA) method. The three-dimensional polar versus azimuthal angle distribution of the oxygen ions showed that the oxygen flow has a north to south velocity component. The observations suggest that the dayside reconnection process is generally steady. The energy dispersion can be explained with the time-of-flight (TOF) effect assuming oxygen ions are escaping from the magnetosphere along the reconnected field lines. The lack of hydrogen and helium ions during the observed oxygen bursts can be explained, as only oxygen ions are resupplied by the gradient drift in the inner magnetosphere because of their larger bounce periods with respect to hydrogen and helium ions. Therefore only oxygen ions are observed continuously in the magnetosheath. The estimated oxygen escape rate amounts to 0.61 x 10(23) ions/s, about 33% of the input rate of the ring current. The observations imply that the stormtime ring current is asymmetric. A large amount of ring current oxygen ions escape from the magnetosphere into the magnetosheath.

    DOI

  • The ion composition in solar energetic particle events observed in 1993-1995

    N Hasebe, T Doke, T Hayashi, J Kikuchii, M Kobayashi, H Shirai, N Takenaka, T Takashima, B Wilken, QG Zong

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   70 ( 10 ) 3167 - 3173  2001.10

     View Summary

    Five large events of solar energetic particles (SEP) during three years from 1993 to 1995 have been observed by high energy particle (HEP) instruments onboard GEOTAIL spacecraft. The composition of energetic ions, their energy spectra and time profiles of ion intensity were measured for the SEP events. Three SEP events observed on Feb. 15, 1993, Mar. 4, 1993 and Oct. 20, 1994, are enriched in Fe ions (> 10 MeV/n). The enhancement of Fe ions was observed at the onset time of SEP events (Mar. 4, 1993 and Oct. 20, 1994). The onset of the SEP events seems to have a feature with "impulsive" and "gradual" characteristics. This indicates a mixture of different seed populations and acceleration processes operating in these events.

    DOI

  • Comparison between 20.02.94 and 14.04.94 SEP and their Possible Sources

    第27回宇宙線国際会議(ハンブルグ)    2001.08

  • ガンマ線及び中性子観測による惑星表面の元素分析

    日本物理学会第56回年次大会 宇宙線シンポジューム 主題 : 宇宙物質研究の最前線/中央大    2001.03

  • Scintillating fiber camera for neutron dosimetry in spacecraft

    K. Terasawa, T. Doke, N. Hasebe, J. Kikuchi, K. Kudo, T. Murakami, N. Takeda, T. Tamura, S. Torii, M. Yamashita, E. Yoshihira

    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment   457 ( 3 ) 499 - 508  2001.01

     View Summary

    A scintillating fiber camera for three-dimensional imaging was newly developed for radiation dosimetry in spacecraft. The camera consists of a scintillating fiber stack, an image intensifier unit and photomultipliers for triggering events. The scintillating fiber stack has 100 scintillating fiber layers. The layers are alternatively stacked up to be perpendicular to each other. The stack is coupled to a two-stage image intensifier and then coupled to a CCD camera for the track readout. Each fiber layer consists of 100 scintillating fibers and the fiber stack composed of 100 layers leads us to a sensitive volume of 50×50×50 mm3. Each fiber has a cross-section of 0.5×0.5 mm2. It is found that the camera has the capability to clearly identify charged particles, neutrons and γ-rays by observing individual three-dimensional images of those tracks. The threshold energy for identification of neutrons and γ-rays is 5-10 MeV for recoil proton energy when the coincidence signals from 2 photomultipliers are used as triggers and is expected to be 2-3 MeV when the triggers from either photomultiplier are used. The whole energy region for neutron dosimetry will be covered by the combination with the Bonner spheres for the energy region lower than approximately 10 MeV.

    DOI

  • Tracing the connectivity of magnetic flux ropes to solar surface with >100keV electrons associated with CME on July 14

    Proc. of 27th ICRC   8,pp.3429-3432  2001

  • The Nucleon-Mission. A. New Approach to Cosmic Rays Investigation.

    Proc. of 27th ICRC   6,pp.2185-2187  2001

  • The Heavy Nuclei Explorer(HNX) Mision

    Proc. of 27th ICRC   6,pp.2181-2184  2001

  • The Energetic Trans-Iron Composition Experiment (ENTICE) on the Heavy Nuclei Explorer (HNX) Mission

    Proc. of 27th ICRC   6,pp.2231-2234  2001

  • Planetary high pressure xenon gamma-ray spectrometer

    V K. Vlasik, N. Hasebe, E. Shibamura, V. Dmitrenko

    Proceedings of the 16th Workshop on Radiation Detectors and Their Uses, KEK   Proceedings of the 16th Worksh   149  2001

  • Measureming the Chemical Compositions of the Surface of Mercury using Orbital Gamma-ray and Nuetron Spectroscopy

    Mercury: Space Environment, Surface and Interior 2001, Chicago, Illinois, USA, Oct.   4-5,8069.pdf  2001

  • High Pressure Xenon Detector for Measurement of Planetary Gamma-Rays

    V. V. Dmitrenko, N. Hasebe, I. V. Chernyshova, O. B. Batkov, V. M. Grachev, S. Kobayashi, T. Miyachi, E. Shibamura, D. V. Sokolov, S. E. Ulin, Z. M. Uteshev, K. F. Vlasik

    IEEE NS   IEEE NS   3980 - 3983  2001

  • ECCO: Th/U/Pu/Cm dating of galactic cosmic ray nuclei

    Proc. of 27th ICRC   6,pp.2235-2238  2001

  • Comparison between 20.02.94 and 14.04.94 SEP and their Possible Sources

    Proc. of 27th ICRC   8,pp.3258-3261  2001

  • The correlation between CIR ion intensity and solar wind speed at 1 AU

    MN Kobayashi, T Doke, J Kikuchi, T Hayashi, K Itsumi, T Takashima, N Takehana, H Shirai, J Yashiro, N Hasebe, K Kondoh, T Yanagimachi, M Nagatani, A Harada, B Wilken

    COUPLING OF THE HIGH AND LOW LATITUDE HELIOSPHERE AND ITS RELATION TO THE CORONA   26 ( 5 ) 861 - 864  2000

     View Summary

    We have investigated the relationship between solar wind speeds and the energetic proton intensity associated with corotating interaction regions (CIR) observed at 1 AU during 1973 - 1995 using NSSDC Data. The speed-difference between the high-speed solar wind and the slow-speed solar wind, which forms CIR at outer heliosphere, shows a good correlation with the peak intensity of 1 - 2 MeV protons during the solar quiet periods. The speed-difference is probably related to the shock strength of the reverse shock of the CIR formed beyond - 1 AU. We have also found the solar activity dependence of the correlation between these quantities in CIR events during the period between 1973 and 1995. The intensity of CIR particles during the solar active periods is higher than that during the quiet periods, suggesting that the density of seed particles in CIR events during the solar active periods is larger than that during the solar quiet period. (C) 2000 COSPAR. Published by Elsevier Science Ltd.

  • The Origin of Matter and Evolution of Galaxies 2000, (OMEGA2000)

    T. Kajino, S. Kubono, K. Nomoto, I. Tanihata

    World Scientific Pub Comp     94 - 104  2000

  • The development of HP-Ge Gamma-Ray Spectrometer cooled by stirling refrigerator on Japanese lunar polar orbiter SELENE

    N Hasebe, T Doke, J Kikuchi, MN Kobayashi, O Okudaira, A Oka, N Yamashita, E Shibamura, T Kashiwagi, T Takashima, K Narasaki, K Tsurumi, K Mori, K Sakai, T Yamamoto, C d'Uston, H Barthe, S Maurice, M Grande, RC Reedy

    PROCEEDINGS OF THE FOURTH INTERNATIONAL CONFERENCE ON EXPLORATION AND UTILISATION OF THE MOON   462   231 - 234  2000

     View Summary

    The development of Gamma-Ray Spectrometer (GRS) is reviewed. Japanese lunar polar orbiter SELENE carries Gamma-Ray Spectrometer (GRS) which uses a high purity Ge detector cooled down to 80-90 K by a Stirling mechanical cooler for the first time in the lunar mission. GRS consists of n-type Ge detector as a main detector and EGO and plastic scintillators as an active shielding detector. The 250 cc Ge-detector is encapsulated in the aluminum canister. Its excellent energy resolution (< 3 keV in fwhm for K-40 gamma-ray line) is attained for engineering model even after severe vibration tests were made. GRS will provide the global mapping for major elements of O, Mg, Al, Si, Ti, Fe, etc. and natural radioactive elements of K, Th and U with a high precision. GRS has such an excellent energy resolution that it would identify prompt gamma-ray line from hydrogen, if there exists water ice at the surface of the lunar polar regions.

  • Cosmic Ray Observation for Nuclear Astrophysics CORONA Program

    N. Hasebe, M.N. Kobayashi

    World Scientific Pub Comp     94 - 104  2000

  • Can water ice at lunar poles be detected by gamma-ray spectrometer on selene?

    MN Kobayashi, N Hasebe, N Yamashita, A Oka, E Shibamura, T Miyachi, C d'Uston, S Maurice

    PROCEEDINGS OF THE FOURTH INTERNATIONAL CONFERENCE ON EXPLORATION AND UTILISATION OF THE MOON   462   183 - 186  2000

     View Summary

    The existence of water ice at polar regions of the Moon is important not only in scientific interests but also utilizing lunar resource for the future exploration. The Clementine over the Moon reported the signature of lunar ice deposited in permanently shaded regions in the South Pole region. Recently, the neutron spectrometer onboard Lunar Prospector found dips in counting rate of epi-thermal neutrons corresponding to polar regions, which indicates the presence of water ice with high probability. However, after the one and half year mission of Lunar Prospector, the controlled crash of the spacecraft into a crater of the south pole region showed no observable signature of water ice. Gamma-Ray Spectrometer (GRS) with high sensitivity and energy resolution will be bearded on the Japanese lunar orbiter SELENE. It has an sufficient capability to detect the prompt gamma-ray line from hydrogen of water ice between the strong peaks of Si and Al lines. The GRS would make the first time detection of water ice deposited at lunar poles, and determine the locations and the amount of water ice on the surface, if it is exposed at polar regions of the Moon.

  • A Small Scintillation Fiber Camera Consisiting of 0.25 mm Square Fibers for Space

    K. Terasawa, T. Doke, N. Hasebe, J. Kikuchi, K. Kudo, N. Takeda, E. Yoshihara

    2000 IEEE NSS-MIC, NS   2000 IEEE NSS-MIC, NS   6.81 - 6.84  2000

  • LET distribution measurement with a new real-time radiation monitoring device-III onboard the Space Shuttle STS-84

    T Sakaguchi, T Doke, N Hasebe, T Hayashi, T Kashiwagi, J Kikuchi, S Kono, S Nagaoka, T Nakano, T Takagi, K Takahashi, S Takahashi

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   437 ( 1 ) 75 - 87  1999.11

     View Summary

    A new type of Real-time Radiation Monitoring Device, RRMD-III, consisting of three double-sided silicon strip detectors (DSSDs) has been constructed and used onboard the Space Shuttle mission STS-84. The Space Shuttle cruised at an altitude of 300-400 km and an inclination angle of 51.6 degrees for 221.3 h. RRMD-III succeeded in measuring the linear energy transfer (LET) distribution over the range of 0.2-600 keV/mu m for 178 h. The obtained LET distribution of particles was investigated in detail by classifying it into galactic cosmic ray (GCR) particles and trapped protons in the South Atlantic Anomaly (SAA region. The result shows that GCR particles contribute 60% to the total dose equivalent. The total absorbed dose rate during the mission was 0.516 mGy/day, the effective quality factor was 1.81 by ICRP-Pub.26, and the dose equivalent rate was 0.935 mSv/day. The average absorbed dose rates are 0.120 mu Gy/min for GCR particles and 4.80 mu Gy/min for trapped protons. The effective quality factors are 3.16 for GCR particles and 1.19 for trapped protons. RRMD-III data were also compared with the data of the tissue equivalent proportional counter (TEPC), proving that RRMD-III is a reliable device for deriving the true-LET distribution in real time for evaluating space radiation. (C) 1999 Elsevier Science B.V. All rights reserved.

    DOI

  • Measurement of the directional distribution of incident particles in the Shuttle-Mir mission orbit

    T Sakaguchi, T Doke, N Hasebe, J Kikuchi, S Kono, T Takagi, K Takahashi, S Nagaoka, T Nakano, S Takahashi, GD Badhwar

    JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS   104 ( A10 ) 22793 - 22799  1999.10

     View Summary

    The measurement of the directional distribution of incident particles was made by using the Realtime Radiation Monitoring Device (RRMD)-III placed inside the Space Shuttle STS-84 cruised at an altitude of 400 km and an inclination angle of 51.6 degrees, which are the same as the cruising orbit of the International Space Station (ISS). The directional distributions of incident particles were evaluated over the observed linear energy transfer (LET) range (1-100 keV/mu m). The pitch angle distribution is also obtained using the geomagnetic model of IGRF-95. The result is roughly in good agreement with the distribution obtained by the VF1-MIN anisotropy model calculation within the present experimental errors, if the shielding distribution is assumed to be uniform.

    DOI

  • Straggling in energy loss of energetic heavy ions (Z <=-8) in thick silicon absorber

    N Hasebe, T Atarashiya, S Mitani, T Doke, J Kikuchi, T Takashima, K Itsumi, M Kobayashi, T Kashiwagi, K Nagata

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   68 ( 5 ) 1556 - 1561  1999.05

     View Summary

    The energy loss distributions of heavy ions (Z less than or equal to 8) with high energies (2 MeV/u-50 MeV/u) in thick silicon detectors with uniform thickness have been measured in a wide range of fractional energy loss, Delta E/E-0, where Delta E is the energy loss and E-0 is the initial energy of incident ions. The measured distributions of energetic He, Li, Be, B and C ions are in good agreement with those predicted from Livingston-Bethe's theory when Delta E/E-0 < 0.2. However, the distributions for large fractional energy lasses Delta E/E-0 > 0.2, which are much wider than those expected from the theory, are approximately expressed by Stoquert's method considering the effect of velocity decrease into Livingston-Bethe's theory. In the previous experiment of the energy loss of heavy ions from K to Fe in thick Si detectors, Hasebe et al. obtained consistent results for heavier elements. By conbining the results in the previous and this works, it is concluded that the straggling in energy loss of heavy ions from roton to Fe with energies from about 5 MeV/u to a few hundred MeV/u in thick Si-absorber is explained by Stoquert's method.

    DOI

  • Observation of time correlation in cosmic air shower network

    T Wada, N Ochi, T Kitamura, W Unno, M Chikawa, Y Kato, T Konishi, K Tsuji, S Ohara, T Takahashi, N Takahashi, N Ohmori, H Sasaki, N Hasebe, Yamamoto, I, T Nakatsuka

    NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS   75A   330 - 332  1999.04

     View Summary

    In order to measure time correlation of primary cosmic rays, a network observation of extensive air showers started in Japan. The network as Large Area Air Shower (LAAS) group consists of nine air-shower-stations (seven institutes and 26,000 km(2)) using the Global Positioning system (GPS). We propose an analytical procedure to extract time-limited fractal structure from time series of arrival time intervals of successive air showers and present the results of the analysis by using the network data.

  • Measurement of the directional distribution of incident particles in the Shuttle-Mir mission orbit

    Takao Sakaguchi, Tadayoshi Doke, Nobuyuki Hasebe, Jun Kikuchi, Sachiko Kono, Toru Takagi, Kenichi Takahashi, Shunji Nagaoka, Tamotsu Nakano, Shimpei Takahashi, Gautam D. Badhwar

    Journal of Geophysical Research: Space Physics   104 ( 10 ) 22793 - 22799  1999  [Refereed]

     View Summary

    The measurement of the directional distribution of incident particles was made by using the Real time Radiation Monitoring Device (RRMD)-III placed inside the Space Shuttle STS-84 cruised at an altitude of 400 km and an inclination angle of 51.6°, which are the same as the cruising orbit of the International Space Station (ISS). The directional distributions of incident particles were evaluated over the observed linear energy transfer (LET) range (1-100 keV/μm). The pitch angle distribution is also obtained using the geomagnetic model of IGRF-95. The result is roughly in good agreement with the distribution obtained by the VF1-MIN anisotropy model calculation within the present experimental errors, if the shielding distribution is assumed to be uniform. Copyright 1999 by the American Geophysical Union.

    PubMed

  • Observation of galactic cosmic ray particles by the HEP-HI telescope on the geotail satellite

    T Doke, N Hasebe, T Hayashi, K Itsumi, J Kikuchi, MN Kobayashi, K Kondoh, H Shirai, T Takashima, T Takehana, Y Yamada, T Yanagimachi, J Yashiro

    TRANSPORT OF GALACTIC AND ANOMALOUS COSMIC RAYS IN THE HELIOSPHERE: OBSERVATIONS, SIMULATIONS AND THEORY   23 ( 3 ) 487 - 490  1999  [Refereed]

     View Summary

    The energy spectra (40 to 300 MeV/n) of galactic cosmic ray particles (C, N, O, Ne, Mg, Si, and Fe) observed by the HEP-HI silicon detector telescope onboard the GEOTAIL satellite were investigated over the period from January 1993 to May 1996, from the viewpoint of solar modulation. From the GEOTAIL data and those of relativistic heavy particles observed by HEAO-3, the modulation potential phi was obtained by using a solution of the Fokker-Plank equation with the "force-field" approximation. In the equation the diffusion coefficient was used as adjustable parameter, under the assumptions of a fixed velocity of solar wind (400 km/sec) and the radius of the heliosphere of 50 AU. The time variation of the modulation potential thus obtained is compared with that obtained from the CLIMAX neutron monitor. A reasonable correlation between both time variations is found when five months delay is applied to the results obtained by the HEP-HI telescope. (C) 1999 COSPAR. Published by Elsevier Science Ltd.

  • The intensity variation of cosmic rays associated with corotating interaction regions

    K Kondoh, N Hasebe, T Doke, J Kikuchi, T Takashima, MN Kobayashi, T Yanagimachi, J Medina, J Sequeiros

    TRANSPORT OF GALACTIC AND ANOMALOUS COSMIC RAYS IN THE HELIOSPHERE: OBSERVATIONS, SIMULATIONS AND THEORY   23 ( 3 ) 591 - 594  1999

     View Summary

    Long-term decrease events in the intensity of galactic cosmic rays have been investigated using solar wind parameters. We investigated distinct long-term decreases in 1993/94 near the solar minimum phase. In this period, the corotating interaction regions were observed over half a year. Recurrent increases of the solar wind speed were observed during this time period, forming corotating interaction regions. Simultaneously recurrent energetic proton events and recurrent decrease of galactic cosmic rays are measured. The baseline counts of neutron monitors was well anti-correlated with the peak speed of solar wind. It is suggested that long-lasting enhancements of solar wind velocity or corotating interaction regions formed by them can produce, the long-term decrease in the galactic cosmic ray intensity. (C)1999 COSPAR. Published by Elsevier Science Ltd.

  • Observation of galactic cosmic ray particles by the HEP-HI telescope on the GEOTAIL satellite

    T. Doke, N. Hasebe, T. Hayashi, K. Itsumi, J. Kikuchi, M. N. Kobayashi, K. Kondoh, H. Shirai, T. Takashima, T. Takehana, Y. Yamada, T. Yanagimachi, J. Yashiro

    Advances in Space Research   23 ( 3 ) 487 - 490  1999

     View Summary

    The energy spectra (40 to 300 MeV/n) of galactic cosmic ray particles (C, N, O, Ne, Mg, Si, and Fe) observed by the HEP-HI silicon detector telescope onboard the GEOTAIL satellite were investigated over the period from January 1993 to May 1996, from the viewpoint of solar modulation. From the GEOTAIL data and those of relativistic heavy particles observed by HEAO-3, the modulation potential φ was obtained by using a solution of the Fokker-Plank equation with the "force-field" approximation. In the equation the diffusion coefficient was used as adjustable parameter, under the assumptions of a fixed velocity of solar wind (400km/sec) and the radius of the heliosphere of 50AU. The time variation of the modulation potential thus obtained is compared with that obtained from the CLIMAX neutron monitor. A reasonable correlation between both time variations is found when five months delay is applied to the results obtained by the HEP-HI telescope. ©1999 COSPAR. Published by Elsevier Science Ltd.

    DOI

  • 月探査SELENE搭載用ガンマ線分光計GRSの開発

    第7回科学衛星・宇宙観測シンポジューム/宇宙科学研究所   7;pp67-70  1999

  • 宇宙船内の速中性子線量計測装置の基礎開発

    第15回宇宙利用シンポジューム/宇宙科学研究所   15;pp212-215.  1999

  • 宇宙線中の超鉄核成分"、宇宙放射線, 1(1998)15-29.

    宇宙放射線   1;pp15-29  1999

  • セレーネα線分光計の開発

    第7回科学衛星・宇宙観測シンポジューム/宇宙科学研究所   7;pp71‐74  1999

  • シャトルミールミッション軌道における粒子入射方向分布の観測

    宇宙放射線   1;pp63-74.  1999

  • Observation of Galactic Cosmic Ray Particles by the HEP-HI Detector onboard the GEOTAIL Satellite", Adv. Space Res., (1998) in press.

    Adv. Space Res.   23,pp487-490  1999

  • Gamma-ray and Alpha-ray Spectrometer Experiment on SELENE Mission

    Lunar Planetary Science Conference 30th (Houston)    1999

  • Gamma-Ray Spectrometer for Japanese lunar polar orbiter

    N Hasebe, E Shibamura, T Atarashiya, T Doke, C d'Uston, M Grande, T Kashiwagi, J Kikuchi, M Kobayashi, K Kubo, S Mitani, K Mori, K Narasaki, K Nomi, T Takashima, R Tanibata, RC Reedy

    MOON AND MARS   23 ( 11 ) 1837 - 1840  1999

     View Summary

    We review the current status of the development of Gamma-Ray Spectrometer (GRS) for the Lunar mission SELENE. The GRS instrument will measure gamma-rays in the energy range from 100 keV to 9 MeV. The instrument is a high-purity Ge detector surrounded by EGO and plastic scintillators which are operated as an anticoincidence shield, and is cooled by a Stirling cycle cryocooler. The primary objective is to provide global maps of the lunar composition. Measurements are anticipated for Fe, Ti, U, Th, K, Si, Mg, Al, O, Ca and Na over the entire lunar surface. The abundance of water ice in the permanently shaded craters at both the lunar poles will be measured with this instrument. (C) 1999 COSPAR. Published by Elsevier Science Ltd.

    DOI

  • Galactic Cosmic Ray and Recurrent Enhancement of Solar Wind Velocity

    Proc.26<SUP>th</SUP>Int.Cosmic Ray Conf.(Utah)   7,pp179-182  1999

  • Energetic Particles associated with High Speed Solar Wind Ambient the Earth

    Adv. Space Res.   in press  1999

  • Composition of Ultraheavy Nuclei in Galactic Cosmic Ray

    Proc. International Doke Symposium (Tokyo)   p104-114  1999

  • The relationship between corotating energetic ion enhancement and solar wind speed at 1 AU

    M Kobayshi, T Doke, J Kikuchi, T Hayashi, T Takashima, N Takehana, H Shirai, N Hasebe, K Kondoh, B Wilken

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   67 ( 11 ) 3991 - 3996  1998.11

     View Summary

    A series of corotating energetic helium events with 3-5 MeV/n has been observed by the HEP telescopes onboard the GEOTAIL satellite at 1AU from October 1993 to August 1994. We have examined the relationship between solar wind (SW) speeds observed at 1AU and the intensity of He in the series of the corotating interaction region (CIR) events. The speed difference of the high-speed SW from slow-speed SW; which forms a CIR in the outer heliosphere, shows a reasonable correlation with the peak intensity of He at 3-5 MeV/n. The speed difference of those SWs is considered to be related to the shock strength which develops in a CIR at a distance from the Sun. Such a correlation between energetic ions associated with CIRs and SW speed has not been shown so far for the events during the period of 1978-1986. We have also investigated the dependence of the relation between the CIR ion events and the SW speeds during the period between 1978 and 1995 which corresponds to the high solar active phase of Solar Cycle 22. There is a good correlation between the SW speed and the peak intensity of CIR energetic ions in the quiet phase of solar activity, but not in the active phase.

    DOI

  • Scintillating Fiber Camera for Neutron Dosimetry in Space

    Adv. Res. Inst. for Sci. and Eng., Waseda Univ.,   Technical Report No.98-16,  1998

  • Pitch Angle Distribution of the Low Latitude Precipitation Electrons

    EOS Trans.AGU,Western Pacific Geophy. Meeting Suppl.   79(24)  1998

  • Radiation dosimetry measurements with real time radiation monitoring device (RRMD)-II in space shuttle STS-79

    T Sakaguchi, T Doke, T Hayashi, J Kikuchi, N Hasebe, T Kashiwagi, T Takashima, K Takahashi, T Nakano, SJ Nagaoka, SP Takahashi, H Yamanaka, K Yamaguchi, GD Badhwar

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   36 ( 12A ) 7453 - 7459  1997.12

     View Summary

    The real-time measurement of radiation environment was made with an improved real-time radiation monitoring device (RRMD)-II onboard Space Shuttle STS-79 (S/MM#4: 4th Shuttle MIR Mission, at an inclination angle of 51.6 degrees and an altitude of 250-400km) for 199 h during 17-25 September, 1996. The observation of the detector covered the linear energy transfer (LET) range of 3.5-6000 keV/mu m. The Shuttle orbital profile in this mission was equivalent to that of the currently planned Space Station, and provided an opportunity to investigate variations in count rate and dose equivalent rate depending on altitude, longitude: and latitude in detail. Particle count rate and dose equivalent rate were mapped geographically during the mission. Based on the map of count rate, an analysis was made by dividing whole region into three regions: South Atlantic Anomaly (SAA) region, high latitude region and other regions. The averaged absorbed dose rate during the mission was 39.3 mu Gy/day for a LET range of 3.5-6000 keV/mu m. The corresponding average dose equivalent rates during the mission are estimated to be 293 mu Sv/day with quality actors from International Commission on Radiological Protection (ICRP)-Pub. 60 and 270 mu Sv/day with quality factors from ICRP-Pub. 26. The effective quality factors for ICRP-Pub. 60 and 26 are 7.45 and 6.88, respectively. From the present data for particles of LET &gt; 3.5keV/mu m, we conclude that the average dose equivalent rate is dominated by the contribution of galactic cosmic ray (GCR) particles. The dose-detector depth dependence was also investigated.

    DOI

  • Parametrization of charge and mass resolution for Delta E-E telescopes

    E Bronchalo, L delPeral, J Medina, J Sequeiros, N Hasebe

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   399 ( 1 ) 65 - 75  1997.11

     View Summary

    A simple parametrization of energy straggling of 2-200 MeV/nucleon heavy ions traversing thick silicon detectors, based on the Tschalar-Payne theory, is presented. With this parametrization, analytical expressions for the charge and mass resolution of energetic ions detected on Delta E-E telescopes can be obtained. Several consequences that can be extracted from these expressions are analysed, especially, in what concerns the thickness selection for multi-detector telescopes. The validity of those analytical formulae are tested with experimental resolutions obtained from calibration data of three different cosmic-ray telescopes.
    PACS: 29.40.Wk; 07.87. + v.

  • The first observation of sulfur in anomalous cosmic rays by the Geotail and the Wind spacecrafts

    T Takashima, T Doke, T Hayashi, J Kikuchi, M Kobayashi, H Shirai, N Takehana, M Ehara, Y Yamada, S Yanagita, N Hasebe, T Kashiwagi, C Kato, K Munakata, T Kohno, K Kondoh, H Murakami, A Nakamoto, T Yanagimachi, DV Reames, TT vonRosenvinge

    ASTROPHYSICAL JOURNAL   477 ( 2 ) L111 - L113  1997.03

     View Summary

    The Geotail high-energy particle instruments have observed cosmic-ray particles in the energy range from 3 MeV n(-1) to 150 MeV n(-1) at 1 AU during the period 1992 September-1995 August. A remarkable enhancement of anomalous cosmic-ray (ACR) N, O, Ne, and C is observed during the period. A measurable enhancement of the sulfur flux below about 20 MeV n(-1) was observed. This is the first evidence showing the existence of sulfur in the anomalous component. The flux increase of anomalous sulfur, with a first ionization potential (FIP) of 10.4 eV, is smaller than that of ACR carbon with an FIP of 11.3 eV and much smaller than those of high-FIP elements, which suggests that the fractions of neutral carbon and sulfur atoms are significantly low in the very local interstellar medium.

  • Measurements of LET Distribution and Dose Equivalent onboard the Space Shuttle IML-2(STS-65) and S/MM 4 (STS-79)

    Hayashi, T. Doke, J. Kikuchi, T. Sakaguchi, R. Takeuchi, T. Takashima, M. Kobayashi, K. Terasawa, K. Takahashi, A. Watanaba, A. Kyan, N. Hasebe, T. Kashiwagi, K. Ogura, S. Nagaoka, M. Kato, T. Nakano, S. Takahashi, H. Yamanaka, K. Yamaguchi, G.D. Badhwar

    Biological Sci. in Space   Biological Sci. in Space ( 4 ) 355 - 364  1997

    DOI

  • Composition and energy spectra of anomalous cosmic rays observed by the geotail satellite

    N Hasebe, K Kondoh, Y Mishima, T Doke, J Kikuchi, T Hayashi, T Takashima, M Kobayashi, N Takehana, H Shirai, T Yanagimachi, A Nakamoto, H Murakami, K Nagata, T Kohno, K Munakata, C Kato, S Yanagita, Y Yamada, M Ehara, T Kashiwagi, Y Muraki, T Koi, J Sequeiros, J Medina, B Wilken

    COSMIC RADIATION: SPECTRA AND COMPOSITION   19 ( 5 ) 813 - 816  1997

     View Summary

    The composition and energy spectra of anomalous cosmic-rays (ACRs) in the energies 6 - 200 MeV/n have been measured during the period from September 1992 to August 1995 using the High Energy Particle instrument onboard the GEOTAIL satellite orbiting at 1 AU. A remarkable enhancement of ACR N, O, Ne and Ar is observed during the period. A flux enhancement of anomalous argon at 1 AU is confirmed by the GEOTAIL satellite. The first possible evidence for the emergence of a measurable sulfur component in ACR below about 20 MeV/n is found, The flux increase of anomalous sulfur with 10.4 eV FIP is smaller than that of ACR carbon with 11.3 eV FIP, and much smaller than those of high FIP elements, which suggests that the fraction of neutral carbon and sulfur atoms is significantly lower in the very local interstellar medium. (C) 1997 COSPAR.

    DOI

  • A new silicon detector telescope for measuring the linear energy transfer distribution over the range from 0.2 to 400 keV/mu m in space

    T Doke, T Hayashi, N Hasebe, J Kikuchi, S Kono, T Murakami, T Sakaguchi, K Takahashi, T Takashima

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   35 ( 12A ) 6241 - 6247  1996.12

     View Summary

    A new telescope consisting of three two-dimensional position-sensitive silicon detectors which can measure the Linear energy transfer (LET) distribution over the range from 0.2 to 400 keV/mu m has been developed as a real-time radiation monitor in manned spacecraft. First, the principle of LET measurement and its design method are described. Second, suitable electronic parameters for the LET measurement are experimentally determined. Finally, the telescope performance is investigated by using relativistic heavy ions. The first in-flight test of this type of telescope on the US Space Shuttle (STS-84) is scheduled for May, 1997.

    DOI

  • Measurement of LET distribution and dose equivalent on board the space shuttle STS-65

    T Hayashi, T Doke, J Kikuchi, R Takeuchi, N Hasebe, K Ogura, S Nagaoka, M Kato, GD Badhwar

    RADIATION MEASUREMENTS   26 ( 6 ) 935 - 945  1996.11

     View Summary

    Space radiation dosimetry measurements have been made on board the Space Shuttle STS-65 in the Second International Microgravity Laboratory (IML-2). In these measurements, three kinds of detectors were used; one is a newly developed active detector telescope called ''Real-time Radiation Monitoring Device (RRMD)'' utilizing silicon semi-conductor detectors and others are conventional detectors of thermoluminescence dosimeters (TLDs) and CR-39 plastic track detectors. Using the RRMD detector, the first attempt of real-time monitoring of space radiation has been achieved successfully for a continuous period of 251.3 h, giving the temporal variations of LET distribution, particle count rates, and rates of absorbed dose and dose equivalent. The RRMD results indicate that a clear enhancement of the number of trapped particles is seen at the South Atlantic Anomaly (SAA) without clear enhancement of dose equivalent, while some daily periodic enhancements of dose equivalent due to high LET particles are seen at the lower geomagnetic cutoff regions for galactic cosmic ray particles (GCRs). Therefore, the main contribution to dose equivalent is seen to be due to GCRs in this low altitude mission (300 km). Also, the dose equivalent rates obtained by TLDs and CR-39 ranged from 146.9 to 165.2 mu Sv/day and the average quality factors from 1.45 to 1.57 depending on the locations and directions of detectors inside the Space-lab at this highly protected orbit fdr space radiation with a small inclination (28.5 degrees) and a low altitude (300 km). The LET distributions obtained by two different detectors, RRMD and CR-39, are in good agreement in the region of 15-200 keV/mm and difference of these distributions in the regions of LET &lt; 15 keV/mm and LET &gt; 200 keV/mm can be explained by considering characteristics of CR-39 etched track formation especially for the low LET tracks. Copyright (C) 1996 Elsevier Science Ltd

    DOI

  • Global distributions of trapped he fluxes from OHZORA satellite during the geomagnetically quiet period of 1984—1987

    N. Hasebe, A. Ryowa, M. Kobayashi, K. Kondoh, J. Hamada, Y. Mishima, K. Nagata, K. Kohno, J. Kikuchi, T. Doke

    Geophysical Monograph Series   97   255 - 258  1996

     View Summary

    We present the global distributions of trapped He (4.8-37 MeV) fluxes in the low altitude region under quiet-time conditions (|Dst| &lt
    30 nT) of geomagnetic activity. Observations were obtained by the OHZORA satellite during 1984-1987 in the altitude of350-850km. We have compared the global distributions of He fluxes with those for trapped electrons and protons at the same altitudes. Auroral zones observed from energetic He are not so prominent as compared with those from electron and proton fluxes. It is found that the anomalous distributions of He fluxes are localized at the South Atlantic Anomaly, while the anomalous distributions of electron and proton fluxes are clearly seen to extend from South Atlantic region to Southern Anomaly. Further, the L-distributions of trapped He fluxes are also examined during quiet-time conditions. It is found that the distributions for lower energies (4.8-13MeV) have two peaks at L =~ 1.4 and ~ 2.7, while the distribution for higher energies (13-37 MeV) has a single peak at L ~ 1.5 and does not have the peak at L =~ 2.7.

    DOI

  • REAL-TIME MEASUREMENT OF LET DISTRIBUTION IN THE IML-2 SPACE-LAB(STS-65)

    T DOKE, T HAYASHI, J KIKUCHI, N HASEBE, S NAGAOKA, M KATO, GD BADHWAR

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   365 ( 2-3 ) 524 - 532  1995.11

     View Summary

    The real time monitoring of environmental radiation in the Space-Lab of STS-65 (IML-2: inclination 28.5 degrees, altitude 300 km) has been achieved successfully through the flight by a new silicon detector telescope called ''Real time Radiation Monitoring Device'' (RRMD). It consists of two 2-dimensional position sensitive silicon detectors and six diode type silicon detectors. In this monitoring, the temporal variation of rates of particle flux, together with the dose equivalent and the LET distribution at three locations in the Space-Lab, were reasonably given in real time. The LET distribution obtained by the RRMD and CR-39 track detectors measured at the same location is in good agreement except at the highest LET region &gt;200 keV/mu m and the lowest LET region &lt;5 keV/mu m.

    DOI

  • The observation of low energy ions accelerated by an interplanetary shock on February 21st 1994 with the Geotail HEP Experiment.

    T Kai, T Terasawa, B Wilken, S Livi, T Doke, J Kikuchi, K Nagata, T Yanagimachi, H Murakami, K Maezawa, N Hasebe, Y Muraki

    24TH INTERNATIONAL COSMIC RAY CONFERENCE, VOL 4     381 - 384  1995  [Refereed]

     View Summary

    We analysis the low energy ions data obtained by Geotail HEP experiment associate with a interplanetary shock. The energy spectra at downstream from the shock is somewhat different from former researchs and have small humps in low energy regions (&lt; 100keV). We find that this feature is explicable in the model of particle acceleration at oblique shock.

  • Space radiation measurement due to RRMD in IML-2 flight experiments

    T Doke, T Hayashi, J Kikuchi, N Hasebe, S Nagaoka, GD Badhwar

    RADIATION RESEARCH 1895-1995, CONGRESS PROCEEDINGS     1191 - 1194  1995  [Refereed]

  • Corotating ion events associated with cosmic ray modulation

    N Hasebe, K Kondoh, M Kobayashi, Y Mishima, T Doke, J Kikuchi, T Hayashi, K Itsumi, T Takashima, T Yanagimachi, H Murakami, A Nakamoto, K Nagata, T Kashiwagi, K Munakata, C Kato, T Kohno, Y Muraki, T Koi, K Maezawa, S Yanagita, T Terasawa, A Nishida, K Fujiki, J Medina, J Sequeiros, B Wilken

    JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY   47 ( 12 ) 1333 - 1338  1995

     View Summary

    Interplanetary ions in a few MeV/n energies were observed by the GEOTAIL spacecraft at 1 AU during the period from December 1993 to April 1994. The measurements were performed with the HEP-particle telescopes on board the GEOTAIL. We have examined the correlation between the interplanetary ion events and cosmic ray modulation. It is found that the variation of counting rates of neutron monitor is well correlated with the flux variation of low energy ions. The corotating interaction regions formed in the interplanetary space significantly affect the intensities not only of low energy galactic cosmic rays (GCRs) but also of high energy GCRs. It implies that corotating streams cause the decrease of GCR flux because they act as barriers that impede the flows of GCRs toward the Sun.

    DOI

  • An electron Fermi acceleration event at an interplanetary shock wave on Feb 21, 1994: GEOTAIL observation

    T Terasawa, M Hoshino, A Nishida, N Shimada, T Mukai, Y Saito, M Hirahara, S Machida, T Koi, K Maezawa, M Fujimoto, B Wilken, K Nagata, N Hasebe, T Doke, S Livi, T Yanagimachi, H Murakamii, T Nagai, T Yamamoto, S Kokubun

    24TH INTERNATIONAL COSMIC RAY CONFERENCE, VOL 4   24th International Cosmic Ray   389 - 392  1995

     View Summary

    We observed a Fermi acceleration event at a passage of a fairly strong quasi-perpendicular interplanetary shock. Gradual exponential increase of the flux levels, which are typical of interplanetary shock acceleration events, were observed both for ions (&gt; 40 keV) and electrons (&gt; several tens of eV) several hours before the shock arrival. Accelerated electrons showed a power-law type energy spectrum, which was significantly softer than what the standard Fermi theory predicts. We attribute this spectral softening to the effect of upstream free escape boundary.

  • RAPID RECOVERY OF ANOMALOUS COSMIC-RAY FLUX AT 1-AU IN SOLAR-CYCLE-22

    N HASEBE, Y MISHIMA, K FUJIKI, M FUJII, M KOBAYASHI, T DOKE, J KIKUCHI, T HAYASHI, T SHINO, T ITO, T TAKASHIMA, T YANAGIMACHI, A NAKAMOTO, H MURAKAMI, K NAGATA, T KOHNO, K MUNAKATA, C KATO, S YANAGITA, T KASHIWAGI, K MAEZAWA, Y MURAKI, A NISHIDA, T TERASAWA, B WILKEN

    GEOPHYSICAL RESEARCH LETTERS   21 ( 25 ) 3027 - 3030  1994.12

     View Summary

    A new observation of low energy cosmic ray particles with the energies from 4 to 120 MeV/n by the HEP instrument onboard the GEOTAIL satellite orbiting at 1 AU shows a remarkable enhancement of aItomalous cosmic ray (ACR) N, O and Ne in the period September 1992 - December 1993 before approaching to the solar minimum in solar cycle 22. The ACR fluxes obtained by the GEOTAIL. observation are in good agreement with the results earlier obtained from the SAMPEX satellite [Mewaldt et al. 1993a,b]. The ACR carbon is also evident though the C enhancement is small compared with those of N, O and Ne. We confirm the new SAMPEX finding that the ACR fluxes have recovered more rapidly in 1992-1993 than in previous solar cycles and find this tendency continues to the end of 1993.

    DOI

  • DETERMINATION OF CHARGE AND ENERGY FOR PARTICLES PENETRATING A SILICON DELTA-EXE TELESCOPE IN-SPACE RADIATION

    T HAYASHI, T DOKE, N HASEBE, K FUJIKI

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   33 ( 7A ) 4106 - 4110  1994.07

     View Summary

    A method of determination of charge and energy for energetic particles penetrating (not stopping) a multilayer silicon DELTAE x E telescope with a finite thickness (12 mm) is examined in the energy region up to several hundreds of MeV/nucleon. From the results of the accelerator experiment, an energy resolution sigma(E) of 1.2% in rms and a charge resolution sigma(Z) of 0.11 charge unit in rms for Fe-group nuclei with energies between 190 and 230 MeV/nucleon are obtained. For lighter elements such as hydrogens and helium ions, an energy resolution sigma(E) of 2.9% is obtained in the energy region between 33 and 42 MeV/nucleon and even their individual isotopes are separated. Also, the energy dependences of these resolutions suggest that this method can be utilized for particles with energies about two times larger than that corresponding to the range of telescope thickness for the evaluation of the space radiation effects even under the limitations of weight, size, and electric power supply.

    DOI

  • THE ENERGETIC PARTICLE SPECTROMETER HEP ONBOARD THE GEOTAIL SPACECRAFT

    T DOKE, M FUJII, M FUJIMOTO, K FUJIKI, T FUKUI, F GLIEM, W GUTTLER, N HASEBE, T HAYASHI, T ITO, K ITSUMI, T KASHIWAGI, J KIKUCHI, T KOHNO, S KOKUBUN, S LIVI, K MAEZAWA, H MORIYA, K MUNAKATA, H MURAKAMI, Y MURAKI, H NAGOSHI, A NAKAMOTO, K NAGATA, A NISHIDA, R RATHJE, T SHINO, H SOMMER, T TAKASHIMA, T TERASAWA, S ULLALAND, W WEISS, B WILKEN, T YAMAMOTO, T YANAGIMACHI, S YANAGITA

    JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY   46 ( 8 ) 713 - 733  1994

     View Summary

    The instruments for the HEP (High Energy Particle) experiments of the GEOTAIL mission, launched in July 1992, consist of 5 spectrometers (LD, BD, MI-1, MI-2 and HI). The LD (Low energy particle Detector) and the BD (Burst Detector) are mainly used to measure electrons, protons, helium and oxygen ions which reflect plasma dynamics in the magnetotail region. On the other hand, MI-1, MI-2 (Medium energy Isotope telescope-1, -2) and HI (High energy Isotope telescope) are used to measure the isotope abundance of solar flare particles and cosmic ray particles which reflect physical conditions of interplanetary space and origin of these particles. In this paper, the objectives of these experiments, the details of the instruments and preliminary results from the observation in the magnetotail are given. The preliminary results obtained by the LD and BD show that a highly collimated beam of energetic particles appear in the plasma sheet just after the substorm onset and that directional distribution of particles can be radically different for different energies. In the MI and HI telescopes, details a remarkable enhancement of anomalous cosmic ray components (N, O) in the quiet time of solar activity is reported, as well as the element composition of galactic cosmic rays.

    DOI

  • ENERGY-LOSS STRAGGLING OF HEAVY CHARGED-PARTICLES IN THICK SILICON ABSORBERS

    N HASEBE, T DOKE, M FUJII, K FUJIKI, T KAJIURA, T KASHIWAGI, J KIKUCHI, M KOBAYASHI, Y MISHIMA, A NAKAMOTO, T SHINO

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   63 ( 1 ) 92 - 100  1994.01

     View Summary

    The energy loss straggling of heavy charged particles with relatively high energies passing through thick uniform Si detectors (1.0 mm-9.2 mm) has been studied in a wide range of the ratio Delta E/E(0) where Delta E is the energy loss and E(0) is the initial energy of the incident particles. The experimental results are compared with those predicted by straggling theories. It suggests that the measured distributions are in good agreement with those predicted from the Bohr's or Livingston-Bethe's theories when Delta E/E(0)&lt;0.3 where the distributions are to be Gaussian-symmetric, However, the distributions for larger energy losses deviate from those expected from the theories. It is found that the experimental data are approximately expressed by the modified Stoquert's theory when the ratio Delta E/E(0)&gt;0.3.

    DOI

  • GENERAL-METHOD TO DETERMINE THE POSITION-CHARGE RELATIONSHIP FOR POSITION-SENSITIVE DETECTORS WITH VARIOUSLY-SHAPED RESISTIVE ANODES

    N HASEBE, K KISO, E KANEDA, T DOKE

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   32 ( 5A ) 2162 - 2166  1993.05

     View Summary

    A new approach using the Green function instead of the method of Fourier expansion is presented to determine the position-charge relationship for radiation detectors employing a charge division on the resistive anode bordered by an additional resistive line. The resistive anode with a polygonal shape is considered as a general case. Theoretical consideration shows that the position of radiation incidence in the position-sensitive detectors is represented in the integral form containing the Green function if the total charge generated in the detector is assumed to be collected over an infinite time. Anodes with the geometries of a triangle, square, circle or spherical triangle are described as practical shapes. It is shown that, when the shape of the anode is (spherical) triangular or square, the relationship between the position and charge is determined by a harmonic function obtained from a simple geometric consideration.

  • IMPROVEMENT OF MASS RESOLUTION OF COSMIC-RAY NUCLEI USING A DELTA-E X E SI DETECTOR TELESCOPE

    N HASEBE, H MORIYA, T DOKE, J KIKUCHI, T KASHIWAGI, S KATAOKA, T SHINO, K ITSUMI, T HAYASHI, T YANAGIMACHI, A NAKAMOTO, H MURAKAMI, K NAGATA, HJ CRAWFORD, JM ENGELARGE, FLORES, I, L GREINER

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   325 ( 1-2 ) 335 - 342  1993.02  [Refereed]

     View Summary

    Using 5-in.-diameter Si(Li) detectors with a detector thickness of 1, 2 and 3 mm combined with 62 mm X 62 mm position-sensitive Si detectors, an excellent isotope telescope has been constructed for the Geotail mission. The performance of the telescope and the individual detectors has been investigated using Fe-56 beams with energies between 430 and 696 MeV/n. The nonuniformity of the detector thickness as measured by exposing the detectors to a monochromatic Fe beam is 0.44% for 1 mm thick detectors, 0.54% for 2 mm thick detectors and 0.15% for 3 mm thick detectors. The secondary isotopes of Al through Fe produced by 430 MeV/n Fe-56 in a polyethylene target were clearly resolved by the telescope. The measured mass resolution for Si, Ca and Mn were 0.36 amu, 0.42 amu and 0.44 amu in FWHM, respectively. The telescope has the following two key features: an excellent resolution (better than 0.5 amu) and an exceptionally high sensitivity (SOMEGA = 43 cm2sr) for a broad range of species from He through Ni with energies between 2.4 and 210 MeV/n.

  • THE GEOTAIL ENERGETIC PARTICLE TELESCOPES

    N HASEBE, H MORIYA, K FUJIKI, M FUJII, H NAGOSHI, T DOKE, J KIKUCHI, T HAYASHI, T KASHIWAGI, T SHINO, K ITSUMI, T ITO, K TAKASHIMA, T YANAGIMACHI, H MURAKAMI, A NAKAMOTO, K NAGATA, T KOHNO, S YANAGITA, K MAEZAWA, Y MURAKI, K MUNAKATA, A NISHIDA, B WILKEN

    23RD INTERNATIONAL COSMIC RAY CONFERENCE, VOL 2     552 - 555  1993  [Refereed]

  • Improvement of Mass Resolution of Cosmic Ray Nuclei using 61508; 61509; 61509; Si Detector Telescope

    N. Hasebe, H. Moriya, T. Doke, J. Kikuchi, T. Kashiwagi, S. Kataoka, T. Shino, K. Itsumi, T. Hayashi, T. Yanagimachi, A. Nakamoto, H. Murakami, K. Nagata, H.J. Crawfo, J.M. Engelarge, I. Flores, L. Greiuner

    Nucl. Instr. and Methods, A325   Nucl. Instr. and Methods, A325   335 - 342  1993

  • SPATIAL AND TEMPORAL FEATURES OF 0.64-35 MEV PROTONS IN THE SPACE STATION ENVIRONMENT - EXOS-C OBSERVATIONS

    MA MIAH, K NAGATA, T KOHNO, H MURAKAMI, A NAKAMOTO, N HASEBE, J KIKUCHI, T DOKE

    JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY   44 ( 8 ) 591 - 610  1992

     View Summary

    The spatial and temporal features of the peak proton flux detected near the equator in the integral energy channel of 0.64-35 MeV by S-1 telescope on board the EXOS-C mission were studied for a period of three years (1984-86). The equatorial zone (+/-30-degrees geomagnetic latitude) proton data obtained for the angle between the telescope axis and the magnetic field direction in the range of 50-degrees-130-degrees and at the peak efficiency of the instrument, were sorted out from a study of the orientation of the telescope axis and calculation of the response function of the telescope. The data, after freed from the major influence of the South Atlantic Anomaly, and subsequently analyzed, revealed some new results contrary to the earlier observation (MORITZ, 1972) in the altitude range of 350 to 850 km. The spatial distribution shows that the global profile of the peak proton flux is aligned with the profile of the minimum magnetic field, and, the peak proton population straddles the minimum magnetic field equator with a full-width-at-half-maximum of about 19-degrees. Also, the pitch angle distribution of the equatorial proton population is found to have the anisotropy index in the range 7 to 10. Further, the proton flux shows altitude, L, and longitude dependences. The flux increases as h1.43 and L4.25-7.50 (corresponding to different equatorial pitch angles). Besides, in the longitude range 180-degrees &lt; phi &lt; 300-degrees, the flux is significantly larger than that in the range 100-degrees &lt; phi &lt; 180-degrees. The fact of L independence of low energy (&lt; 5 MeV) protons, and the strong L dependence (L81) of high energy (&gt; 5 MeV) protons, has been used to infer the presence of a major low energy component and a minor high energy component. In the study of temporal features, comparison of absolute fluxes during two solar epochs shows that the proton flux during the solar minimum in 1984-86 was, at least, 40 times less than that during the solar maximum condition in 1982, possibly, due to lesser amount of hydrogen escape to the exosphere during the minimum condition, and thereby causing less precipitation of low energy particles in the equatorial atmosphere.

    DOI

  • Position Linearity and Resolution of Large Position-Sensitive Silicon Detector with a High Uniform Thickness

    N. Hasebe, T. Doke, T. Kashiwagi, S. Kataoka, J. Kikuchi, H. Moriya, K. Nishijima, H. J. Crawford

    pn, J. Appl. Phys. 31-1   pn, J. Appl. Phys. 31-1   591 - 610  1992

  • ACCELERATOR BEAM EXPERIMENTS OF A PROTOTYPE COSMIC-RAY HEAVY-ION TELESCOPE

    T KOHNO, K MUNAKATA, T IMAI, A YONEDA, C KATO, M MATSUOKA, T DOKE, J KIKUCHI, T KASHIWAGI, K NISHIJIMA, N HASEBE, HJ CRAWFORD

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   60 ( 11 ) 3967 - 3975  1991.11

     View Summary

    A Heavy Ion cosmic ray Telescope (HIT) has been scheduled to be launched into the synchronous orbit in 1993 aiming to observe elemental and isotopic composition of solar energetic particles and galactic cosmic rays. In this paper, we report the results of accelerator beam experiments of a prototype model of HIT. The telescope consists of two dimensional Position Sensitive Detectors (PSDs) and energy loss detectors (PIN type and Li-drifted type). The mass resolution was 1.1 amu in FWHM for 110 MeV/n pure iron (Fe-56) beam. By exposing HIT to beams consisting of various nuclides produced by the projectile fragmentation process in a reaction induced by Fe-56 beam, we confirmed that the secondary elements from 16S to 25Mn were clearly separated and that also the isotopes were separated for each elements lighter than 22Ti. The observed mass resolution was 0.57 amu, 0.66 amu and 0.82 amu in FWHM for 18Ar, 20Ca and 22Ti, respectively. We can conclude that the HIT has good prospects of enough ability for our current purpose in space observation.

    DOI

  • CALIBRATION EXPERIMENT OF HIGH-ENERGY HEAVY COSMIC-RAY ISOTOPE IDENTIFIER FOR GEOTAIL

    K NAGATA, T DOKE, J KIKUCHI, T KASHIWAGI, N HASEBE, H MURAKAMI, A NAKAMOTO

    22ND INTERNATIONAL COSMIC RAY CONFERENCE, VOLS 1-5     B479 - B482  1991  [Refereed]

  • IDENTIFICATION OF PROJECTILE FRAGMENTS USING POSITION-SENSITIVE SILICON DETECTORS

    WP LIU, T KUBO, H KUMAGAI, T NAKAGAWA, T SUZUKI, M YANOKURA, TANIHATA, I, T ITO, T KASHIWAGI, J KIKUCHI, H YAMAGUCHI, T DOKE, H MURAKAMI, T YANAGIMACHI, N HASEBE

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   287 ( 3 ) 476 - 480  1990.02

    DOI

  • NEW TWO-DIMENSIONAL POSITION-SENSITIVE SILICON DETECTOR WITH GOOD POSITION LINEARITY AND RESOLUTION

    T YANAGIMACHI, T DOKE, N HASEBE, T IMAI, T KASHIWAGI, J KIKUCHI, T KOHNO, WP LIU, K MUNAKATA, T MOTOBAYASHI, H MURAKAMI, K NAGATA, A NAKAMOTO, H YAMAGUCHI

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   275 ( 2 ) 307 - 314  1989.02

    DOI

  • ELECTRON (0.19-3.2 MEV) AND PROTON (0.58-35 MEV) PRECIPITATIONS OBSERVED BY OHZORA SATELLITE AT LOW LATITUDE ZONES L = 1.6-1.8

    K NAGATA, T KOHNO, H MURAKAMI, A NAKAMOTO, N HASEBE, J KIKUCHI, T DOKE

    PLANETARY AND SPACE SCIENCE   36 ( 6 ) 591 - 606  1988.06

    DOI

  • CHARGE WAVEFORM OF A NEW TWO-DIMENSIONAL POSITION-SENSITIVE SILICON DETECTOR

    N HASEBE, Y EZAWA, H YOSHII, T YANAGIMACHI

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS   27 ( 5 ) 816 - 820  1988.05

    DOI

  • Intensity Maps of MeV Electrons and Protons below the Radiation Belts

    T. Kohno, K. Munakata, K. Nagata, H. Murakami, A. Nakamoto, N. Hasebe, J. Kikuchi, T. Doke

    Planet. Space Sci., 36   Planet. Space Sci., 36   591 - 606  1988

  • MASS AND ENERGY LIMIT OF ISOTOPE IDENTIFICATION OF HEAVY-IONS USING DELTA-E-E SILICON-DETECTOR TELESCOPE

    N HASEBE, H YOSHII, T DOKE, K NAGATA

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   26 ( 12 ) 2086 - 2089  1987.12

  • THE GIOTTO IMPLANTED ION SPECTROMETER (IIS) PHYSICS AND TECHNIQUE OF DETECTION

    B WILKEN, W WEISS, W STUDEMANN, N HASEBE

    JOURNAL OF PHYSICS E-SCIENTIFIC INSTRUMENTS   20 ( 6 ) 778 - 785  1987.06

    DOI

  • DRIFT CHAMBERS FOR THE OBSERVATION OF MULTITRACKS IN COSMIC-RAY AIR SHOWERS

    H YOSHII, N HASEBE

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   249 ( 2-3 ) 506 - 514  1986.09

    DOI

  • OHZORA HIGH-ENERGY PARTICLE OBSERVATIONS

    K NAGATA, T KOHNO, H MURAKAMI, A NAKAMOTO, N HASEBE, T TAKENAKA, J KIKUCHI, T DOKE

    JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY   37 ( 3 ) 329 - 345  1985

    DOI

  • New Satellite Device for Measuring Nuclear and Charge State Compositions of Energetic Solar Particles

    N. Hasebe, T. Doke

      Waseda Univ. 105   80 - 90  1983

  • OBSERVATION OF FALLOUT RATES OF ATMOSPHERIC BE-7 AND NA-22 PRODUCED BY COSMIC-RAYS CONCERNING ESTIMATION OF THE FALLOUT RATE OF ATMOSPHERIC AL-26

    N HASEBE, T DOKE, J KIKUCHI, Y TAKEUCHI, T SUGIYAMA

    JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS   86 ( NA2 ) 520 - 524  1981

    DOI

  • MEASUREMENTS OF RELATIVISTIC ELECTRON-ENERGY LOSS DISTRIBUTIONS IN THIN GAS LAYERS

    K NAGATA, J KIKUCHI, T DOKE, A NAKAMOTO, N HASEBE

    NUCLEAR INSTRUMENTS & METHODS   172 ( 3 ) 609 - 611  1980

    DOI

  • The Effect of Transition Radiation on the Ionization Loss of Relativistic Electrons Passing through a Gas Proportional Counter

    N. Hasebe, J. Kikuchi, T. Doke, K. Nagata, A. Nakamoto

      Phys.11   97 - 100  1978

    DOI

  • Energy Loss of Relativistic Electrons and Its Fluctuation in Gas Proportional Counters

    N. Hasebe, J. Kikuchi, T. Doke, K. Nagata, A. Nakamoto

        491 - 501  1978

    DOI

  • Superheavy elements (author's transl)

    Hasebe, N, Miyoshi, Y

    Radioisotopes. 26(8)(1977)577-586.   26(8)(1977) ( 26(8)(1977) ) 577 - 586  1977.08

  • Ionization Loss of Relativistic Electrons and Its Fluctuations in Gas Proportional Counters

    K. Nagata, A. Kuge, A. Nakamoto, N. Hasebe, J. Kikuchi, T. Doke

      Phys. 9   1907 - 1917  1976.04

    DOI

  • Energy Loss and Straggling of High-Energy Electrons in Silicon Detectors

    K. Nagata, T. Doke, J. Kikuchi, N. Hasebe, A. Nakamoto

      Phys.14   697 - 701  1975.05

▼display all

Books and Other Publications

  • Nuclear Planetary Science

    N. Hasebe, K.J. Kim, E. Shibamura, K. Sakurai(Vol. 1, 2018, Series Ed. Wing-Huen Ip, World Scientific.)

    Advances in Planetary Science  2018

  • 人類の夢を育む天体“月”

    長谷部 信行, 桜井邦朋

    恒星社厚生閣  2013.01

Misc

  • The CALorimetric Electron Telescope (CALET) on the international space station: Results from the first two years on orbit

    Y. Asaoka, O. Adriani, Y. Akaike, K. Asano, M. G. Bagliesi, E. Berti, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, A. Bruno, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, K. Kohri, H. S. Krawczynski, J. F. Krizmanic, T. Lomtadze, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, S. Nakahira, J. Nishimura, G. A. De Nolfo, S. Okuno, J. F. Ormes, S. Ozawa, L. Pacini, F. Palma, V. Pal'Shin, P. Papini, A. V. Penacchioni, B. F. Rauch, S. B. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, F. Stolzi, S. Sugita, J. E. Suh, A. Sulaj, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tsunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida

    Journal of Physics: Conference Series   1181 ( 1 )  2019.03  [Refereed]

     View Summary

    © Published under licence by IOP Publishing Ltd. The CALorimetric Electron Telescope (CALET) is a high-energy astroparticle physics space experiment installed on the International Space Station (ISS), developed and operated by Japan in collaboration with Italy and the United States. The CALET mission goals include the investigation of possible nearby sources of high-energy electrons, of the details of galactic particle acceleration and propagation, and of potential signatures of dark matter. CALET measures the cosmic-ray electron+positron flux up to 20 TeV, gamma-rays up to 10 TeV, and nuclei with Z=1 to 40 up to 1, 000 TeV for the more abundant elements during a long-term observation aboard the ISS. Starting science operation in mid-October 2015, CALET performed continuous observation without major interruption with close to 20 million triggered events over 10 GeV per month. Based on the data taken during the first two-years, we present an overview of CALET observations: 1) Electron+positron energy spectrum, 2) Nuclei analysis, 3) Gamma-ray observation including a characterization of on-orbit performance. Results of the electromagnetic counterpart search for LIGO/Virgo gravitational wave events are discussed as well.

    DOI

  • CURRENT STATUS OF DEVELOPMENT FOR ACTIVE X-RAY FLUORESCENCE SPECTROMETER FOR FUTURE PLANETARY MISSIONS.

    H. Nagaoka, N. Hasebe, H. Kusano, M. Naito, E. Shibamura, H. Kuno, K. J. Kim, J. A. M. Lopes, J. Martinez-Frias

    METEORITICS & PLANETARY SCIENCE   50  2015.08

    Research paper, summary (international conference)  

  • VARIATIONS IN KREEP-ENRICHMENT OF NWA 773 CLAN OLIVINE GABBROS AND BRECCIAS BASED ON WHOLE-ROCK COMPOSITIONS

    H. Nagaoka, Y. Karouji, T. J. Fagan, M. Ebihara, H. Takeda, N. Hasebe

    METEORITICS & PLANETARY SCIENCE   50  2015.08

    Research paper, summary (international conference)  

  • The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

    O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, G. Bigongiari, W. R. Binns, S. Bonechi, M. Bongi, J. H. Buckley, G. Castellini, M. L. Cherry, G. Collazuol, K. Ebisawa, V. Di Felice, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, M. H. Israel, A. Javaid, E. Kamioka, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, N. Kawanaka, H. Kitamura, T. Kotani, H. S. Krawczynski, J. F. Krizmanic, A. Kubota, S. Kuramata, T. Lomtadze, P. Maestro, L. Marcelli, P. S. Marrocchesi, J. W. Mitchell, S. Miyake, K. Mizutani, A. A. Moiseev, K. Mori, M. Mori, N. Mori, H. M. Motz, K. Munakata, H. Murakami, Y. E. Nakagawa, S. Nakahira, J. Nishimura, S. Okuno, J. F. Ormes, S. Ozawa, F. Palma, P. Papini, B. F. Rauch, S. B. Ricciarini, T. Sakamoto, M. Sasaki, M. Shibata, Y. Shimizu, A. Shiomi, R. Sparvoli, P. Spillantini, I. Takahashi, M. Takayanagi, M. Takita, T. Tamura, N. Tateyama, T. Terasawa, H. Tomida, S. Torii, Y. Tunesada, Y. Uchihori, S. Ueno, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, T. Yuda

    EPJ Web of Conferences   95  2015.05

     View Summary

    © Owned by the authors, published by EDP Sciences, 2015. The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF).

    DOI

  • 30pTF-9 Development of stacked silicon strip detectors for MeV electron on board the Geospace exploration satellite "ERG"

    Mitani T., Kasahara S., Takashima T., Hirahara M., Hasebe N.

    Meeting abstracts of the Physical Society of Japan   69 ( 1 ) 108 - 108  2014.03

    CiNii

  • O11-06 かぐやGRSで得られた月表面の鉄成分の全球分布(口頭発表セッション11(月科学・探査),口頭発表)

    晴山 慎, 山下 直之, 唐牛 譲, 長岡 央, 小林 進悟, 長谷部 信行

    日本惑星科学会秋期講演会予稿集   2013   "O11 - 06"  2013.11

    CiNii

  • 月惑星探査に向けた能動型蛍光X線分光器AXSの基本特性(III)

    内藤雅之, 長谷部信行, 草野広樹, 長岡央, 児玉拓郎, 大山裕輝, 田中玲子, 天野嘉春, 柴村英道, 久野治義, FAGAN T. J., 太田亨, 岡田達明, KIM K. J.

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   74th  2013

    J-GLOBAL

  • P1-06 月の速中性子分布と平均原子質量数分布(ポスターセッション1,ポスター発表)

    晴山 慎, 藤林 ゆかり, 唐牛 譲, 小林 進悟, 山下 直之, Reedy Robert C., Gasnault Olivier, 長谷部 信行

    日本惑星科学会秋期講演会予稿集   2012   101 - 101  2012.10

    CiNii

  • COMPARISONS OF MINERALOGY OF PURE ANORTHOSITE IN LUNAR METEORITES, DHOFAR 489 GROUP AND PURE ANORTHOSITE OBSERVED BY KAGUYA

    H. Nagaoka, H. Takeda, Y. Karouji, M. Ohtake, A. Yamaguchi, S. Yoneda, N. Hasebe

    METEORITICS & PLANETARY SCIENCE   47   A286 - A286  2012.07

    Research paper, summary (international conference)  

  • What "Kaguya" Has Seen in Her Hometown

    HASEBE Nobuyuki, YAMASHITA Naoyuki

      67 ( 2 ) 78 - 85  2012.02

     View Summary

    The Kaguya mission was the large scaled exploration program for the Moon since the Apollo mission. Aimed to reveal its origin and evolution process and also to help planning the future utilization of the Moon, the Kaguya satellite carried 14 scientific instruments to the lunar orbit and successfully observed the elemental and mineral composition, topography, underground structure, magnetic anomaly, and gravity field over the entire surface of the Moon. One of the instruments, Gamma-Ray Spectrometer with high energy resolution, has measured global distributions of the major and trace elements on the Moon. A material composition that constitutes a stellar object can be determined by observing line gamma rays emitted from its surface, providing an important clue for its history. With an emphasis on the gamma-ray observation, we introduce the results on the exploration of the lunar materials achieved by the Kaguya mission and the future direction of the lunar exploration.

    CiNii

  • S22-05P SELENE-2に向けたその場元素分析のためのガンマ線・中性子分光計の開発状況(一般ポスターセッション2,ポスター発表)

    三谷 烈史, 小林 進悟, 唐牛 譲, 長谷部 信行, GNSチーム

    日本惑星科学会秋期講演会予稿集   2011   125 - 125  2011.10

    CiNii

  • S13-01 「かぐや」ガンマ線分光計による高速中性子の月面強度分布(口頭セッション13:月科学,口頭発表)

    藤林 ゆかり, 晴山 慎, 唐牛 譲, 小林 進悟, 山下 直之, Gasnault O., Reedy R.C., 長岡 央, 早津 佳那子, 長谷部 信行

    日本惑星科学会秋期講演会予稿集   2011   24 - 24  2011.10

    CiNii

  • Estimation of space weathering effects by the major element compositions of the Apollo samples

    OHTA T., FAGAN T., AMANO Y., HASEBE N.

      2011   21 - 21  2011.09

    CiNii

  • GLOBAL DISTRIBUTION OF SILICON BY KAGUYA GAMMA-RAY SPECTROMETER

    H. Nagaoka, N. Hasebe, K. J. Kim, Y. Karouji, S. Kobayashi, M. Hareyama, N. Yamashita, O. Gasnault, O. Forni, C. d'Uston, R. C. Reedy, E. Shibamura, M. N. Kobayashi, H. Takeda

    METEORITICS & PLANETARY SCIENCE   46   A171 - A171  2011.07

    Research paper, summary (international conference)  

  • 次世代月探査衛星SELENE2搭載ガンマ線・中性子分光計の開発

    長谷部信行, 小林進悟, 三谷烈史, 唐牛譲, 早津佳那子, 長岡央, 森田幹雄, 町田二郎, 水谷崇人

    応用物理学関係連合講演会講演予稿集(CD-ROM)   58th   ROMBUNNO.24P-EA-16  2011.03

    J-GLOBAL

  • 205 「かぐや」ガンマ線分光計による月面観測から得た月全球における鉄およびチタン分布地図(オーラルセッション4 月1)

    唐牛 譲, 小林 進悟, 晴山 慎, 山下 直之, 長谷部 信行, 柴村 英道, 小林 正規, 早津 佳那子, 長岡 央, 町田 二郎, 森田 幹雄, 藁科 至智

    日本惑星科学会秋期講演会予稿集   2010   30 - 30  2010.10

    CiNii

  • P015 月表面探査ガンマ線分光計の定量元素分析の性能(ポスターセッション2)

    小林 進悟, 三谷 烈史, 唐牛 譲, 長谷部 信行, SELENE-2用ガンマ線中性子分光計検討チーム

    日本惑星科学会秋期講演会予稿集   2010   95 - 95  2010.10

    CiNii

  • CHEMICAL SIGNATURES IN BULK ELEMENT COMPOSITION FOR NORTHWEST AFRICA 2977

    H. Nagaoka, Y. Karouji, H. Takeda, M. Ebihara, N. Hasebe

    METEORITICS & PLANETARY SCIENCE   45   A146 - A146  2010.07

    Research paper, summary (international conference)  

  • SPATIALLY HIGH-RESOLUTION ELEMENTAL MAPS OF THE MOON USING KAGUYA GRS DATA

    Y. Karouji, N. Hasebe, S. Kobayashi, M. Hareyama, N. Yamashita, O. Gasnault, O. Forni, C. d&apos;Uston, R. C. Reedy, E. Shibamura, M. Kobayashi, T. Arai, M. Ebihara, T. Sugihara, H. Takeda, K. J. Kim, J. M. Dohm, K. Hayatsu, H. Nagaoka, J. Machida

    METEORITICS & PLANETARY SCIENCE   45   A101 - A101  2010.07

    Research paper, summary (international conference)  

  • Elemental Composition of the Lunar Surface Observed by Kaguya Gamma-Ray Spectrometer

    KAROUJI Y., HASEBE N., YAMASHITA N., KOBAYASHI S., HAREYAMA M., KOBAYASHI M., SHIBAMURA E., OKUDAIRA O., HAYATSU K., NAGAOKA H., TAKEDA Y., TSUKADA K., MACHIDA J., WARASHINA Y., MORITA M.

      2009   26 - 26  2010.04

    CiNii

  • The ambient dose equivalent from lunar gamma-rays observed by Kaguya gamma-ray spectrometer

    Y. Takeda, K. Hayatsu, S. Kobayashi, M. Hareyama, N. Hasebe, S. Kodaira, K. J. Kim

    Advances in Geosciences: Volume 19: Planetary Science (PS)     69 - 76  2010.01

     View Summary

    The gamma-ray spectrometer (GRS) onboard the lunar polar explorer, SELENE (KAGUYA), globally measured gamma rays emitted from the lunar surface. Using the gamma-ray data observed by the GRS, global map of ambient dose equivalent due to lunar gamma rays for the first time are obtained for the energies from 200 keV to 10 MeV. The dose due to gamma rays on the lunar surface during the period of 2008 at solar minimum of solar activity ranges from 2.58 to 4.30 mSv/yr, depending on the regions of the Moon, which give higher than that due to gamma rays from natural radioactivity isotopes at the Earth. It is found that the dose is high in mare regions, especially the Procellarum KREEP Terrain, where natural radioactive isotopes such as U, Th and K and major elements such as Fe and Ti are abundant.

    DOI

  • P212 SELENE-2に向けたガンマ線・中性子分光計の開発と目指すサイエンス(ポスターセッション2)

    長谷部 信行, 小林 進悟, 三谷 烈史

    日本惑星科学会秋期講演会予稿集   2009   97 - 97  2009.09

    CiNii

  • P209 かぐやガンマ線分光計の月撮像から得たレゴリス中の自然放射性元素の絶対濃度(ポスターセッション2)

    小林 進悟, 奥平 修, 唐牛 譲, 晴山 慎, 山下 直之, 長谷部 信行, 柴村 英道, 小林 正規, 早津 佳那子, 武田 侑子, 塚田 耕一, 長岡 央, 町田 二郎, 森田 幹雄, 藁科 至智

    日本惑星科学会秋期講演会予稿集   2009   94 - 94  2009.09

    CiNii

  • SELENE2ローバー搭載用中性子・ガンマ線分光計 I

    長谷部信行, 鳥居祥二, 片岡淳, 唐牛譲, 山下直之, 武田侑子, 長岡央, 森田幹雄, 小林進悟, 晴山慎, 三谷烈史, 高島健, 飯島祐一, 小林正規, 荒井朋子, D’USTON Claude, KIM Kyeong Ja, BRUECKNER Johannes

    応用物理学会学術講演会講演予稿集   70th ( 1 ) 141  2009.09

    J-GLOBAL

  • CALET Mission for the Observation of Cosmic Rays on the International Space Station

    TAMURA Tadahisa, TORII Shoji, KASAHARA Katsuaki, OKUDAIRA Osamu, HASEBE Nobuyuki, HAREYAMA Makoto, MIYAJIMA Hiromitsu, MIYAJI Takashi, YAMASHITA Naoyuki, UENO Shiro, SAITO Yoshitaka, TAKAYANAGI Masahiro, TOMITA Hiroshi, NISHIMURA Jun, FUKE Hideyuki, YAMAGAMI Takamasa, OKUNO Shoji, TATEYAMA Nobuto, HIBINO Kinya, SHIOMI Atsushi, SHIOMI Atsushi, TAKITA Masato, YUDA Toshinori, SHIMIZU Yuki, KAKIMOTO Fumio, TSUNESADA Yoshiki, TERASAWA Toshio, KOBAYASHI Tadashi, YOSHIDA Atsumasa, YAMAOKA Kazutaka, KATAYOSE Yusaku, SHIBATA Makio, YOSHIDA Kenji, ICHIMURA Masaichi, KURAMATA Shuichi, UCHIHORI Yukio, KITAMURA Hisashi, MURAKAMI Hiroyuki, KOMORI Yoshiko, MIZUTANI Kohei

    Transactions of the Japan Society for Aeronautical and Space Sciences, Space Technology Japan (Web)   7 ( ists26 )  2009

    J-GLOBAL

  • Improvement of charge resolution for intermediate energy heavy ion using CR-39 plastic nuclear track detector

    S. Ota, S. Ota, N. Yasuda, S. Kodaira, M. Kurano, S. Naka, N. Hasebe

    31st International Cosmic Ray Conference, ICRC 2009    2009.01

     View Summary

    It is essential for the study of galactic cosmic ray origin to measure precise cross section of projectile fragmentation for heavy ion on hy-drogen and helium target at intermediate energy between a few hundred and a few thousand MeV/nucleon in laboratory system. As charge identification determines the measurement preci-sion of cross section, an improvement of charge resolution for heavy ions with intermediate ener-gy using CR-39 PNTD has been made. We showed that a limitation of Z was about 20 for the identi-fication of nuclear charge Z with enough charge resolution &lt; 0.15 charge units (cu) in rms) under optimized etching time, depending on the projec-tile energy. However, the charge resolution of the CR-39 PNTD is found to be drastically improved by averaging the measurement data of multiple layers of the CR-39. This improvement leads us an excellent charge resolution better than 0.15 cu. for a wide range of elements as for projectile. These results will support us to measure the fragmentation cross sections precisely using CR-39 PNTD.

  • SELENE2ローバー搭載用中性子・ガンマ線分光計

    長谷部信行, 鳥居祥二, 片岡淳, 唐牛譲, 山下直之, 武田侑子, 森田幹雄, 小林進悟, 晴山慎, 三谷烈史, 高島健, 小林正規, 荒井朋子, D’USTON Claude, KIM Kyeong Ja, BRUECKNER Johannes

    宇宙科学技術連合講演会講演集(CD-ROM)   53rd   1J02  2009

    J-GLOBAL

  • SELENE2ローバ搭載用ガンマ線・中性子分光計

    森田幹雄, 長谷部信行, 鳥居祥二, 片岡淳, 唐牛譲, 早津佳那子, 武田侑子, 長岡央, 三谷烈史, 小林進悟, 晴山慎, 飯島祐一, 高島健, 小林正規, 荒井朋子, D’USTON C, GASNAULT O, 山下直之, KIM K. J, DOHM J. M

    太陽系科学シンポジウム講演集録(CD-ROM)   31st   ROMBUNNO.12GATSU21NICHI,14  2009

    J-GLOBAL

  • "New method of the precise measurement for the thickness and bulk etch rate of the solid-state track detector" [Nucl. Instr. and Meth. A 574 (2007) 163-170] (vol 574, pg 163, 2007)

    S. Kodaira, N. Yasuda, N. Hasebe, T. Doke, S. Ota, K. Ogura

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   593 ( 3 ) 635 - 635  2008.08

    Other  

    DOI

  • Most ferroan feldspathic lunar meteorite NWA 2200

    H. Nagaoka, Y. Karouji, T. Arai, K. Shinotsuka, M. Ebihara, N. Hasebe

    METEORITICS & PLANETARY SCIENCE   43 ( 7 ) A107 - A107  2008.07

    Research paper, summary (international conference)  

  • Elemental mapping of the moon by the selene GRS observation

    Y. Karouji, N. Hasebe, E. Shibamura, M. -N. Kobayashi, O. Okudaira, N. Yamashita, S. Kobayashi, M. Hareyama, T. Miyachi, S. Kodaira, S. Komatsu, K. Hayatsu, K. Iwabuchi, S. Nemoto, Y. Takeda, K. Tsukada, H. Nagaoka, M. Ebihara, T. Hihara, T. Arai, T. Sugihara, H. Takeda, C. d'Uston, O. Gasnault, B. Diez, O. Fomi, S. Maurice, R. C. Reedy, K. J. Kim

    METEORITICS & PLANETARY SCIENCE   43 ( 7 ) A70 - A70  2008.07

    Research paper, summary (international conference)  

  • Investigation on piezoelectric lead zirconate titanate detector bombarded obliquely with hypervelocity iron particles

    S. Takechi, T. Onishi, S. Minami, T. Miyachi, M. Fujii, N. Hasebe, K. Mori, K. Nogami, H. Ohashi, S. Sasaki, H. Shibata, T. Iwai, E. Gruen, R. Srama, N. Okada

    PLANETARY AND SPACE SCIENCE   56 ( 9 ) 1309 - 1313  2008.07

     View Summary

    A cosmic dust detector for use onboard a satellite is currently being constructed from piezoelectric lead zirconate titanate (PZT). The characteristics of the PZT detector were studied by bombarding it with hypervelocity iron particles, which were supplied by a Van de Graaff accelerator. There was a linear relationship between the rise time of the signal observed from the detector and the particle&apos;s velocity, which was above 10 km/s on impact. It was also found that the rise time was almost independent of the collisional angle between the particles and the PZT surface within the limits of the particle&apos;s parameters used in this experiment. (c) 2008 Elsevier Ltd. All rights reserved.

    DOI CiNii

  • Study of high performance solid-state track detectors for the identification of trans-iron nuclei

    2007 Annual Report of the Research Project with Heavy Ions at NIRS-HIMAC     228 - 229  2008.06  [Invited]

    Article, review, commentary, editorial, etc. (other)  

  • Distributions of potassium, thorium and uranium on the lunar surface observed by Gamma-ray Spectrometer aboard SELENE (KAGUYA)

    KOBAYASHI SHINGO, HASEBE NOBUYUKI, SHIBAMURA EIDO, MIYACHI TAKASHI, TAKASHIMA TAKESHI, KOBAYASHI MASANORI, OKUDAIRA OSAMU, YAMASHITA NAOYUKI, HAREYAMA MAKOTO, KAROUJI YUZURU, KODAIRA SATOSHI, EBIHARA MITSURU, ARAI TOMOKO, SUGIHARA TAKAMITSU, TAKEDA HIROSHI, IWABUCHI KAZUYA, HAYATSU KANAKO, NEMOTO SHINPEI, HIHARA TAKESHI, D'USTON CLAUDE, MAURICE SYLVESTRE, GASNAULT OLIVIER, FORNI OLIVIER, DIEZ BENEDICTE, REEDY ROBERT C, KIM KYEONG JA

    Proc ISAS Lunar Planet Symp (CD-ROM)   41st   ROMBUNNO.18  2008

    J-GLOBAL

  • Elemental mapping of the moon with the selene gamma-ray spectrometer

    R. C. Reedy, N. Hasebe, E. Shibamura, T. Miyachi, T. Takashima, M.-N. Kobayashi, O. Okudaira, N. Yamashita, S. Kobayashi, Y. Karouji, M. Hareyama, O. Gasnault, S. Maurice, C. d'Uston

    METEORITICS & PLANETARY SCIENCE   42   A129 - A129  2007.08

    Research paper, summary (international conference)  

  • A possible mechanism to form the source composition of galactic cosmic rays as viewed from the fractionation of heavy elements in carbonaceous chondrites

    Kunitomo Sakurai, Makoto Hareyama, Satoshi Kodaira, Nobuyuki Hasebe

    Proceedings of the 30th International Cosmic Ray Conference, ICRC 2007   2   133 - 136  2007.01

     View Summary

    Referring to the observed data in the depletions of elements, refractory and siderophile, in the interstellar clouds, the chemical composition of dust grains has been deduced, though it is highly variable among these clouds. This variability seems to reflect upon the place where such dust grains are formed inside these clouds. Deep inside the clouds, the chemical composition of dust grains is well coincident with that of carbonaceous chondrites as classified as CI. Since the source composition of galactic cosmic rays in much more abundant in refractory and siderophile elements, being classified as heavy and ultraheavy ones, as compared with those as contained in carbonaceous CI chondrites, the most of volatile elements must have been lost during the process which took place in forming the matter as identified to be &#039;seed mass&#039; which is to be later accelerated to cosmic ray every this process seems necessarily to be associated with the heating and ionization of dust grains formed within interstellar clouds. Volatile elements must have effectively been lost from chondrites though that process, which become process, and then form the seed mass, which becomes the source matter from which cosmic rays are generated afterward.

  • Charge and mass composition of heavy ions in the earth's radiation belt

    Makoto Hareyama, Nobuyuki Hasebe, Satoshi Kodaira, Naoki Masuyama, Shuya Ota, Kunitomo Sakurai, Tateo Goka, Hideki Koshiishi, Haruhisa Matsumoto

    Proceedings of the 30th International Cosmic Ray Conference, ICRC 2007   1   647 - 650  2007.01

     View Summary

    Energetic heavy ions with 20∼200 MeV/nucleon in the radiation belts have been observed by Heavy Ion Telescope (HIT) onboard TSUBASA satellite. The data observed during quiet periods in the outer region of radiation belt indicate that the relative abundance for major elements are similar to that of primary nuclei in galactic cosmic rays obtained by ACE/CRIS experiment, in particular for the ratio of 22Ne/20Ne, while the absolute intensities there were less than that obtained by ACE/CRIS. On the other hand, in the inner region of radiation belt near the earth, both energetic 3He and 4He isotopes were enhanced, in particular for 3He, however, no energetic heavy ions except for energetic nuclei as Li-B, N and Ar were observed. Thus the charge and mass composition of heavy ions is essential to our consideration of possible sources and behavior of energetic heavy ions trapped in the radiation belt.

  • Development of high resolution solid-state track detector for ultra heavy cosmic ray observation

    S. Kodaira, T. Doke, M. Hareyama, N. Hasebe, S. Ota, K. Sakurai, M. Sato, N. Yasuda, S. Nakamura, T. Kamei, H. Tawara, K. Ogura

    Proceedings of the 30th International Cosmic Ray Conference, ICRC 2007   2   425 - 428  2007.01

     View Summary

    The observation of trans-iron nuclei in galactic cosmic rays (Z 30) requires a high performance cosmic ray detector telescope with a very large exposure area because of their extremely low fluxes. It is realized by the use of solid-state track detector of CR-39, which has an advantage of easy extension of exposure area. The verification of mass and nuclear charge identifications with the CR-39 detector newly developed for the observation of heavy cosmic ray particles has been made using Fe ions from NIRS-HIMAC. Mass and charge resolutions for Fe nuclei are found to be 0.22 amu and 0.22 cu in rms, respectively. Moreover, it is necessary to raise the Z/detection threshold in order to suppress background tracks produced by galactic cosmic rays with Z/&lt;30. The new track detectors of copolymers of CR-39 and DAP (diallyl phthalate) have been developed and verified as for their performances. It was found that the newly CR-39 detector has a capability to observe trans-iron nuclei in galactic cosmic rays.

  • High performance measurement system of large area solid-state track detector array for ultra heavy cosmic rays

    S. Kodaira, T. Doke, M. Hareyama, N. Hasebe, K. Sakurai, S. Ota, M. Sato, N. Yasuda, S. Nakamura, T. Kamei, H. Tawara, K. Ogura

    Proceedings of the 30th International Cosmic Ray Conference, ICRC 2007   2   429 - 432  2007.01

     View Summary

    In the handling of solid-state track detector (SSTD), a long period and many human powers has been historically required for a long period and many human powers to scan and analyze etch pits produced on the detector. Because a large area greater than a few m2 detector is required to observe ultra heavy nuclei in galactic cosmic rays, a high speed scanning system is practically important to realize the analysis of our observation data. The apparatus to locate quickly the position of UH event produced in the large SSTD using optical methods was developed, and it allows us effectively to trace incident particle trajectory in cosmic ray detector telescope. We have developed the fast automated digital imaging optical microscope (HSP-1000) to scan and analyze the etch pit produced on the detector, whose image acquisition speed is 50-100 times faster than conventional microscope system. Furthermore, analyzing massive cosmic ray track data produced in extremely large exposed area requires a completely automated multi-sample scanning system. The developed automated system consists of a modified HSP-1000 microscope for image acquisition, a robot arm to replace the sample trays, a magazine station for storing sample trays, and a scanning and analyzing computer to control the whole system. Moreover, since the thickness measurement accuracy in local area of SSTD was improved to achieve high charge and mass resolutions, the new system has been developed to measure the SSTD thickness located adjacent to etch pit in SSTD with an excellent resolution of ± 0.2 m.

  • Magnetic storm associated with energetic particle event of January 21, 2005

    S. N. Kuznetsov, Yu I. Denisov, B. Yu Yushkov, N. Hasebe, M. Hareyama, S. Kodaira, K. Sakurai, N. Masuyama, M. Akiyama, K. Hama

    Proceedings of the 30th International Cosmic Ray Conference, ICRC 2007   1   163 - 166  2007.01

     View Summary

    A strong magnetic storm occurred in January 21st, 2005. During this magnetic storm, the fluxes of electrons trapped in the radiation belt were observed simultaneously with two low altitude orbital satellites, CORONAS-F and SERVIS-1 and some geostationary satellites, LANLs. The data obtained from these satellites indicated the shrinkage and recovery of magnetopause depending on local time and of the radiation belts depending on the energy of trapped electrons during the storm.

  • Report on the Working Group "High Energy Cosmic Ray Observation"

    Torii Shoji, Hasebe Nobuyuki, Miyajima Mitsuhiro, Miyachi Takashi, Hareyama Makoto, Okudaira Osamu, Yamashita Naoyuki, Kodaira Satoshi, Nishimura Jun, Makino Fumiyoshi, Yamagami Takamasa, Saito Yoshitaka, Fuke Hideyuki, Takayanagi Masahiro, Ueno Shiro, Tomita Hiroshi, Tamura Tadahisa, Tateyama Nobuhito, Yoshida Kenji, Okuno Shoji, Hibino Kinya, Yuda Toshinori, Shibata Makio, Katayose Yusaku, Kuramata Shiyuuichi, Ichimura Masakatsu, Uchihori Yukio, Kitamura Hisashi, Kasahara Katsuaki, Murakami Hiroyuki, Kobayashi Tadashi, Komori Yoshiko, Mizutani Kouhei, Terasawa Toshio

      ( 22 )  2006.03

     View Summary

    The Twenty-second Space Utilization Symposium (January 17-19, 2006: Science Council of Japan, Roppongi, Tokyo, Japan)We report the activities on the working group "High Energy Cosmic Ray Observation". We have been developing the CALET instrument on-board the Japanese Experiment Module/ Exposed Facility, JEM/EF, of the ISS. We have successfully concluded the mission concept study and the fundamental technical development. By organizing the working group to prepare the mission proposal, we have done much progress on establishing the international team for instrument development, making a written proposal of the project and constructing a proto-type detector for balloon experiments.Physical characteristics: Original contains color illustrationsMeeting sponsors: The Science Council of Japan, The Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS)(JAXA)

    CiNii

  • 地上実験データに基づく圧電性超高速微粒子計測素子の校正方法

    宮地孝, 藤井雅之, 長谷部信行, 蔵座元英, 佐々木晶, 岩井岳夫, 野上謙一, 大橋英雄, 松本晴久, 矢野創, 柴田裕実, 南繁行, 大西俊之, 武智誠次, GRUEN E., SRAMA R.

    宇宙航空研究開発機構特別資料 JAXA-SP-   ( 05-024 )  2005

    J-GLOBAL

  • He and Ne isotopes in radiation belts observed by HIT onboard TSUBASA Satellite

    M. Hareyama, M. Asaeda, M. Fujii, N. Hasebe, N. Kajiwara, S. Kodaira, K. Sakurai, T. Goka, H. Koshiishi, H. Matsumoto

    Proceedings of the 29th International Cosmic Ray Conference, Vol 2: SH3   2   121 - 124  2005

     View Summary

    The energetic heavy ions from helium to iron were observed by Heavy Ion Telescope (HIT) onboard the TSUBASA satellite from March, 2002 to September, 2003 in the geostationary transfer orbit. Their isotopes were also separated that the mass resolution is similar to 0.24 amu for helium isotopes and similar to 0.35 amu for neon isotopes. He-3 and He-4 for helium with 20-40 MeV/n and Ne-20 and Ne-22 for neon with 50-100 MeV/n in the quiet periods were analyzed to obtain the spatial and temporal variation of fluxes of both isotopes. The enhancement of He-3 flux as compared with He-4 one in the region than 2L was found, while no neon isotopes were observed in the same region. Moreover, the ratios of He-3/He-4 and Ne-22/Ne-20 in the region than 3L are comparable to those of galactic cosmic rays. These results might suggest that the injection and loss mechanism of heavy ions differ between inner and outer radiation belts.

  • Particle monitors to survey radiation environment in the radiation belts onboard Japanese satellites, USERS and SERVIS-1

    M. Hareyama, M. Asaeda, M. Fujii, N. Hasebe, N. Kajiwara, S. Kodaira, K. Sakurai, M. Akiyama, K. Ichiji, K. Hama

    Proceedings of the 29th International Cosmic Ray Conference Vol 1: SH1 and SH2   1   257 - 260  2005

     View Summary

    USERS satellite launched on 10 Sep. 2002 and SERVIS-1 satellite launched on 30 Oct. 2003 employed space-based observatory to provide spatial distribution of energetic charged particles and its variation to study the nature of radiation environment in the radiation belts. USERS satellite carries light particle detectors looking at different three directions to measure electrons, protons and alpha particles and a dose monitor. SERVIS-1 also carries a light particle detector to measure electrons, protons, alpha particles and heavy ions, single event upset monitors, dose monitors and shielded dose monitors. The flight performance of the instruments and the observation of energetic electrons, protons, alpha particles and heavy ions measured in the radiation belts were described.

  • Space and time correlations of particle fluxes after giant flares in radiation belts observed by two satellites, USERS and SERVIS-1

    S. Kodaira, A. Asaeda, M. Fujii, M. Hareyama, N. Hasebe, N. Kajiwara, K. Sakurai

    Proceedings of the 29th International Cosmic Ray Conference Vol 1: SH1 and SH2   1   83 - 86  2005

     View Summary

    Energetic particles trapped in radiation belts were measured by Light Particle Detectors (LPDs) onboard two satellites, USERS and SERVIS-1. LPDs on USERS observed trapped protons with 15 - 130 MeV and electrons with 0.8 - 20 MeV in the inner belt for the period from September, 2002 to February, 2005. LPD on SERVIS-1 has been observing 1.2 - 130 MeV protons and 0.3 - 10 MeV electrons in the inner and outer radiation belt since November, 2003. It is found that the intensities of protons with 1 - 30 MeV and electrons with 0.3 - 2 MeV in the inner radiation belt at L &lt; 2 rapidly increased after the flare on 28 October 2003 and then slowly decreased for many months. Furthermore, a new belt is found to be formed in association at L ~ 2 with large geomagnetic storms connected with big solar flares.

  • The CALET mission on International Space Station

    S. Torii, T. Tamura, N. Tateyama, K. Hibino, T. Yuda, K. Yoshida, K. Kashiwagi, S. Okuno, J. Nishimura, T. Yamagami, Y. Saito, H. Fuke, M. Takayanagi, H. Tomida, S. Ueno, F. Makino, M. Shibata, Y. Katayose, S. Kuramata, M. Ichimura, Y. Uchihori, H. Kitamura, K. Kasahara, H. Murakami, T. Kobayashi, Y. Komori, K. Mizutani, T. Terasawa, R. E. Streitmatter, J. W. Mitchell, L. M. Barbier, A. A. Moiseev, J. F. Krizmanic, J. F. Ormes, W. R. Binns, M. H. Israel, H. S. Krawzczynski, G. Caser, M. L. Cherry, T. G. Guzik, J. B. Isbert, J. P. Wefel, P. S. Marrocchesi, P. Maestro, M. G. Bagliesi, V. Millucci, M. Meucci, G. Bigongiari, R. Zei, F. Ligabue, F. Morsani, O. Adrianiu, P. Papini, P. Spillantini, L. Bonechiu, E. Vannuccini, J. Chang, W. Gan, T. Lu

    Proceedings of the 29th International Cosmic Ray Conference, Vol 3: OG1   2   329 - 332  2005

     View Summary

    The CALorimetric Electron Telescope (CALET) mission is proposed for the observation of various components of cosmic-rays as well as gamma-rays on the Exposure Facility of the, Japanese Experiment Module ( EF/JEM) on the International Space Station (ISS). The detector is composed of an imaging calorimeter of scintillating fibers (IMC), a total absorption calorimeter of BGO (TASQ and a silicon pad module at the top of IMC. The total thickness of absorber is 36 r.1 for the electromagnetic particles and 1.8 m.f.p for protons. The total weight of the payload, including the detector, the support, the interface instruments with JEM so on, is nearly 2,500 kg and the geometrical factor for the electrons is about 1 m(2) sr. The CALET has a unique capability to measure electrons and gamma-rays beyond 1 TeV since the hadron rejection power is 10(6). The energy resolution for the electro-magnetic particles is better than a few % above 100 GeV. The detector is optimally designed to detect changes in the energy spectra caused by physical processes, or a line signature in the energy distribution expected from annihilations of dark matter candidates. This paper is the first presentation by the international team of the CALET collaboration.

  • Empirical formulas for hypervelocity impact with a piezoelectric element and their application to a new real-time dust detector

    T. Miyachi, M. Fujii, N. Hasebe, G. Kuraza, K. Nogami, T. Iwai, S. Sasaki, H. Ohashi, S. Hasegawa, H. Yano, H. Shibata, E. Grün, R. Srama, N. Okada, T. Tou

    IEEE Nuclear Science Symposium Conference Record   1   423 - 427  2005

     View Summary

    Hypervelocity collisions of microparticles with a lead-zirconate-titanate piezoelectric element are examined. The waveforms thus obtained depend on the velocities during collision, and are classified into three categories. In particular, the first cycle of the signal observed immediately after collision is essential to obtain information on the impact. In each category, experimental formulas that are functions of the impact velocity are established based on experimental data. It is concluded that a single piezoelectric element can potentially measure the velocity and/or momentum of hypervelocity microparticles in real time. In the abovementioned context, the new dust detectors are described. © 2005 IEEE.

    DOI

  • 圧電素子PZTを使用したダストのリアルタイム検出

    長嶋 敦, 藤井 雅之, 長谷部 信行

    宇宙科学シンポジウム   4   535 - 538  2004.01

    CiNii

  • SELENE-Bローバ搭載用ガンマ線分光計(GRS)

    長谷部 信行, 宮地 孝, 小池 貴之

    宇宙科学シンポジウム   3   89 - 92  2003.01

    CiNii

  • 圧電素子(PZT)を使用した超高速微粒子のリアルタイム検出器開発

    野上 謙一, 宮地 孝, 長谷部 信行

    宇宙科学シンポジウム   3   341 - 344  2003.01

    CiNii

  • Development of a real-time detector using piezoelectric (PZT) elements for hypervelocity microparticles

    Nagashima Atsushi

    Meeting Abstracts of the Physical Society of Japan   58 ( 0 ) 120 - 120  2003

    DOI CiNii

  • 25aZA-11 -Detection of high energy heavy ions by piezoelectric detectors-

    Ito H.

    Meeting abstracts of the Physical Society of Japan   57 ( 1 ) 139 - 139  2002.03

    CiNii

  • 26pZA-1 Measurements of electron mobility and diffusion constant in high pressure xenon

    Kobayashi S., Takenouchi M., Igarashi T., Hasebe N., Miyachi T., Okada H., Doke T., Shibamura E., Vlasik K.F., Dmitrenko V.V.

    Meeting abstracts of the Physical Society of Japan   57 ( 1 ) 159 - 159  2002.03

    CiNii

  • 26pZA-8 Experiment on Thickness Uniformity of 92mm x 92mm Si Detectors by using an Ar 400 Mev/u Beam

    Hasebe N., Miyachi T., Shibata T., Okada H., Okudaira O., Takemura H., Yamashita N., Shiina A., MikI D., Fujimura G., Mutou N., Tanaka R., Uchihori Y.

    Meeting abstracts of the Physical Society of Japan   57 ( 1 ) 160 - 160  2002.03

    CiNii

  • 26pZA-7 Compararison between Geant4 Simulation and Proton Exposure Experiment for the Evaluation of Lunar Orbital Gamma-Ray Spectrometer

    Yamashita Naoyuki, Hasebe Nobuyuki, Shibamura Eido, Fukuoka Takaaki, Miyachi Takashi, Kase Masayuki, Okada Hiroyuki, Okudaira Osamu, Oka Akihiro, Koike Takayuki, Souri Masafumi, Hiramoto Takuji, Mikami Masahiro

    Meeting abstracts of the Physical Society of Japan   57 ( 1 ) 160 - 160  2002.03

    CiNii

  • 25aZA-10 Development of Realtime Detectors to Hypervelocity MicroparticlesUsing PZT Ceramics

    Yoshioka Hideki

    Meeting Abstracts of the Physical Society of Japan   57 ( 0 ) 138 - 138  2002

    DOI CiNii

  • ダスト衝突実験と宇宙塵観測計画

    柴田裕実, 小林紘一, 佐々木晶, 杉田精司, 矢野創, 大橋英雄, 野上謙一, 長谷部信行, 吉岡秀樹

    UTNL-R(東京大学大学院工学系研究科附属原子力工学研究施設)   ( 0413 ) 61 - 66  2001.11

    J-GLOBAL

  • 内惑星領域と水星近傍の固体微粒子(ダスト)計測

    野上謙一, 長谷部信行, 宮地学, 矢野創, 佐々木晶, 大橋英雄

    太陽系科学シンポジウム   22nd   116 - 119  2001.03

    J-GLOBAL

  • P205 Gamma-Ray Spectrometer

    d'Uston C., Grande M.

    Abstracts Fall Meeting of the Japanese Society for Planetary Sciences   2000   59 - 59  2000.10

     View Summary

    Japanese lunar polar orbiter SELENE carries a gamma-ray spectrometer which uses a high-purity Ge detector cooled down to 80-90 K by a Stirling mechanical cooler for the first time in the lunar mission. The Gamma-Ray Spectrometer (GRS) consists of an n-type Ge detector with a large volume of 〜250 cc as a main detector and BGO and plastic scintillators as an active shielding detector. Its excellent energy resolution is attained for engineering model even after severe vibration tests were made. GRS will provide the global mapping of the Moon for major elements of O, Mg, Al, Si, Ti, Fe, etc. and natural radioisotopes of K, Th and U with a high precision. GRS has such an excellent energy resolution that it would identify prompt gamma-ray line from hydrogen and the location and the amount of ice, if there exists water ice at polar regions.

    CiNii

  • Energy Loss Straggling of Energetic Light Ions in Silicon Detectors.

    長谷部信行, 新谷敏夫, 村田健史, 近藤光志, 道家忠義, 菊池順, 高島健, 逸見憲史, 柏木利介

    愛媛大学工学部紀要   17   473 - 482  1998.02

    J-GLOBAL

  • The Intensity Variation of Galactic Cosmic Rays by Merging Interacton Regions.

    近藤光志, 長谷部信行, 道家忠義, 菊池順, 柳町朋樹, 長谷方道, 藤井善次郎, WILKEN B, MCDONALD F B

    愛媛大学工学部紀要   17   463 - 471  1998.02

    J-GLOBAL

  • SP3 Gamma Ray Spectrometer

    Hasebe N., Tanibata R., Shibamura E., Doke T., Kikuchi J., Goka T., Nisimura J., Kashiwagi T.

    Abstracts Fall Meeting of the Japanese Society for Planetary Sciences   1996   28 - 28  1996.10

    CiNii

  • Data Analysis of The HEP-HI Telescope on board The GEOTAIL Satellite

    T.Takashima, T.Doke, N.Hasebe

    Advanced Research Institute for Science and Engineering, Technical Report   96 ( 13 )  1996

  • The Short-Term Modulation of Galactic Cosmic Rays Associated with Interplanetary Shocks

    Hasebe Nobuyuki, Kondoh K, Kobayashi M

    Memoirs of the Faculty of General Education, Ehime University   28 ( 2 ) 59 - 69  1995.12

    CiNii

  • Global Distributions of Trapped Particle Fluxes Observed by OHZORA Satellite during 1984-1987

    Ryowa, N.Hasebe, M.Kobayashi

    愛媛大学教養部紀要   28  1995

  • Cosmic Ray and Solar Energetic Particle Observation by the HEP Telescopes Onboard the GEOTAIL Satellite

    N.Hasebe, Y.Mishima, K.Fujiki

    RIKEN Review   4   53 - 54  1994

  • POSITION LINEARITY AND RESOLUTION OF LARGE POSITION-SENSITIVE SILICON DETECTOR WITH A HIGHLY UNIFORM THICKNESS

    N HASEBE, T DOKE, T KASHIWAGI, S KATAOKA, J KIKUCHI, H MORIYA, K NISHIJIMA, HJ CRAWFORD

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   31 ( 4 ) 1191 - 1193  1992.04

     View Summary

    Large two-dimensional position-sensitive silicon detectors (PSDs) with good position linearity, resolution and thickness uniformity have been developed. The PSDs have an effective area of 62 mm x 62 mm and a thickness of 500-mu-Am. The non-linearity and position resolution for the whole sensitive area are found to be less than 0.26 mm in rms and 0.44 mm in fwhm, respectively, when an energy of 157 MeV is deposited in the detector and a shaping time constant of 12-mu-s is used in the pulse processing. The non-uniformity of detector thickness is less-than-or-equal-to 0.1% in rms. The PSDs recently developed are good enough to separate iron isotopes in a telescope aboard the GEOTAIL spacecraft scheduled to be launched at July in 1992.

  • INTENSITY MAPS OF MEV ELECTRONS AND PROTONS BELOW THE RADIATION BELT

    T KOHNO, K MUNAKATA, K NAGATA, H MURAKAMI, A NAKAMOTO, N HASEBE, J KIKUCHI, T DOKE

    PLANETARY AND SPACE SCIENCE   38 ( 4 ) 483 - 490  1990.04

    DOI CiNii

  • 30p-PS-28 Search for Proton-rich New Isotopes

      44 ( 1 ) 66 - 66  1989.03

    CiNii

  • 1p-F2-2 技術試験衛星による重粒子観測計画(宇宙線(一次線,重力,その他))

    河野 毅, 今井 喬, 宗像 一起, 松岡 勝, 加藤 博, 千葉 悦也, 大内 徹也, 森山 隆, 柳町 朋樹, 村上 浩之, 中本 淳, 道家 忠義, 菊池 順, 長谷部 信行, 永田 勝明

    年会講演予稿集   43 ( 1 ) 74 - 74  1988.03

    CiNii

  • 31a-H1-7 『大空』電子,陽子観測(宇宙線(起源・一次線・宇宙物質))

    永田 勝明, 河野 毅, 村上 浩之, 中本 淳, 長谷部 信行, 竹中 哲喜, 菊池 順, 道家 忠義

    年会講演予稿集   40 ( 1 ) 118 - 118  1985.03

    CiNii

  • Large scale observation program of ultra heavy nuclei in galactic cosmic rays

    N. Hasebe, T. Doke, M. Hareyama, S. Kodaira, T. Miyachi, M. Miyajima, O. Okudaira, K. Sakurai, S. Ota, M. Sato, Y. Shimizu, M. Takano, S. Torii, N. Yamashita, N. Yasuda, S. Nakamura, T. Kamei, H. Tawara, K. Ogura, S. Mikado, H. Shibuya, K. Nakazawa, A. J. Westph

    Proceedings of the 30th International Cosmic Ray Conference, ICRC 2007   2   51 - 54

     View Summary

    Our galaxy is filled with relativistic nuclei and electrons, being called galactic cosmic rays (GCRs). The origin of GCRs nuclei is still unknown. The precise observation of ultra heavy (UH) GCRs (Z ≥ 30) is important to resolve the remaining problems in cosmic ray astrophysics. Observation program of UH nuclei in GCRs is proposed with the use of high performance solid-state track detector (SSTD) on board long-duration balloon. The program focuses to measure the isotopic abundance above iron-peak elements and the composition of the rare ultra heavy nuclei up to actinide elements with relativistic energy. The observation of nuclear composition covers a wide range of scientific themes including studies of nucleosynthesis of cosmic ray sources, chemical evolution of galactic material, the characteristic time of cosmic rays, heating and acceleration mechanism of cosmic ray particles. In order to achieve the objectives, the super-ressure balloon capable of carrying very large scientific payloads for long extended period is best suited. The possible approach based on a large telescope array consisting of modularized SSTD stacks is described.

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Other

  • radiation dose

    2019.08
     
     

Research Projects

  • Isotope Observation in the SOHO-COSTEP Research Program

  • 超薄型大面積シリコン位置検出器の開発

    科学研究費助成事業(愛媛大学)  科学研究費助成事業(一般研究(C))

  • Investigation of the Geomagnetic Tail by the GEOTAIL Satellite

  • Origin of Anomalous Cosmic Rays and the Acceleration Mechanism

  • Si-detector telescope as real time monitoring devices for measurement of LET-distribution in the space

  • 宇宙線異常成分による局所星間媒質の化学組成

    科学研究費助成事業(愛媛大学)  科学研究費助成事業(一般研究(C))

  • 宇宙線核成分による太陽圏内及びその周辺の粒子起源・加速機構・伝播機構

    科学研究費助成事業(愛媛大学)  科学研究費助成事業(重点領域研究)

  • Non-Thermal Ion Populations in the Interplanetary Space

  • BAIKAL DUMAND : Extremely High Energy Neutrino Astrophysics

  • High Pressure Xe Gamma Ray Detector

  • Precise measurement of ultra-heavy nuclei in cosmic rays

  • Development of automatic system for precise analysis of massive data in glass track detectors

  • Velocity measurement of hypervelocity microparticles by a piezoelectric element

  • 音響型放射線検出器の医療支援への試み

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(萌芽研究)

  • Development of Compton Imaging Device for Gamma Rays in MeV Region by The Use of High-pressure Xenon Gas

  • 4π in-situ-detector for hypervelocity microparticles

  • Development of the next generation solid xenon detector for dark matter search

  • 新しい電極構造を有する希ガス電離箱の開発と環境計測への応用

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(挑戦的萌芽研究)

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Presentations

  • CR-39・銀活性リン酸塩ガラスによるUイオン検出

    Presentation date: 2015.03

  • “X-ray generator for active X-ray fluorescence spectrometer on-board landing rover for future planetary missions”

    Presentation date: 2015.03

  • 月周回衛星による月ガンマ線及び中性子の線量空間分布

    Presentation date: 2015.03

  • Coplanar電極を用いた希ガス電離箱の開発III

    Presentation date: 2015.03

  • 焦電結晶を用いたX線発生器の動作特性(Ⅱ)

    Presentation date: 2015.03

  • 地震前兆現象に関連する電子降下の研究

    Presentation date: 2014.12

  • Nuclear Planetology and Nuclear Spectroscopic Approach to Study Near Earth Asteroids

    Presentation date: 2014.11

  • 地震に伴うエネルギー粒子降下

    Presentation date: 2014.11

  • “将来の惑星探査に向けた小型放射線分光装置の提案”

    Presentation date: 2014.09

  • Coplanar電極を用いた希ガス電離箱の開発II

    Presentation date: 2014.09

  • Development of an X-ray generator using a pyroelectric crystal for X-ray fluorescence analysis on planetary landing missions

    Presentation date: 2014.08

  • RADIATION MEASUREMENT ABOVE THE LUNAR SURFACE BY KAGUYA GAMMA-RAY SPECTROMETER.

    Presentation date: 2014.08

  • Radiation Environment on the Moon

    Presentation date: 2014.07

  • Hydrogen in the Surface Layer of Lunar Polar Regions from Kaguya Gamma-ray Observation

    Presentation date: 2014.07

  • Distributions of Titanium on the Moon by Kaguya Gamma-Ray Spectrometer (KGRS).

    Presentation date: 2014.07

  • Increased Luminosity of Pyroelectric X-ray Generator for Active X-ray Spectrometer on SELENE-2

    Presentation date: 2014.07

  • Experimental and numerical studies on X-ray fluorescence analysis for active X-ray spectrometer on SELENE-2

    Presentation date: 2014.07

  • Nuclear Spectroscopic Approach to Study M-type Asteroides

    Presentation date: 2014.06

  • SPACE RADIATION MEASUREMENT ABOVE THE LUNAR SURFACE

    Presentation date: 2014.06

  • Global Distribution of Titanium on the Moon Observed by Kaguya Gamma-Ray Spectrometer –Implication of the enrichment of Ti in Mare Tranquillitatis-.

    Presentation date: 2014.06

  • RADIATION DOSE IN THE VERTICAL HOLE OF THE MOON

    Presentation date: 2014.04

  • Development of a pyroelectric X-ray generator for X-ray fluorescence analysis on future lunar and planetary landing missions

    Presentation date: 2014.04

  • Titanium distributions on the moon by Kaguya gamma-ray spectrometer (KGRS).

    Presentation date: 2014.04

  • Basic studies on X-ray fluorescence analysis for active X-ray spectrometer on SELENE-2

    Presentation date: 2013.08

  • Lunar Surface Abundances of Natural Radioactive Elements: Implication of Lunar Crustal Origin

    Presentation date: 2013.06

  • Radiation Dose on the Lunar Surface Based on the Definition of Protection Quantity and Operational Quantity

    Presentation date: 2013.06

  • “Development of X-ray Generator for Active X-ray Spectrometer on SELENE-2/Rover

    Presentation date: 2013.06

  • Development of X-ray Generator for Active X-ray Spectrometer on SELENE-2/Rover

    Presentation date: 2013.06

  • Depth Dependency of Radiation Dose Produced by Galactic Cosmic Rays in the Lunar Surface and Subsurface

    Presentation date: 2013.05

  • Distribution of lunar fast neutrons observed by Kaguya Gamma-Ray Spectrometer

    Presentation date: 2013.05

  • Global distribution of natural radioactive elements observed by Kaguya Gamma-Ray Spectrometer

    Presentation date: 2013.05

  • Pyroelectric X-ray generator for active X-ray spectrometer on the rover of SELENE-2

    Presentation date: 2013.05

  • Radiation dose in the lunar subsurfaceproduced by galactic cosmic rays

    Presentation date: 2013.05

  • Lunar olivine gabbro, Northwest Africa 2977 and 6950: Implication for lunar young volcanism

    Presentation date: 2013.05

  • SELENE DATA FOR MINERALOGY AND GEOCHEMISTRY (MI, SP, GRS DATA)

    Presentation date: 2013.01

  • THE RELATIONSHIP BETWEEN THE ABUNDANCE OF RADIOACTIVE ELEMENTS AND ERUPTION AGE OF LUNAR MARE BASALT IN THE PROCELLARUM KREEP TERRANE

    Presentation date: 2013.01

  • Development of a Pyroelectric X-ray Generator for Active X-ray Spectrometer of SELENE-2

    Presentation date: 2013.01

  • Radiation dose of the Moon

    Presentation date: 2012.10

  • Purely Anorthosite clasts in feldspathic lunar meteorites, Dhofar 489 group

    Presentation date: 2012.10

  • Comparisons of Mineralogy of Pure Anorthosite in Lunar Meteorites , Dhofar 489 Group and Pure Anorthosite Observed by Kaguya

    Presentation date: 2012.08

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Specific Research

  • 高密度キセノン中の電子輸送と発光量の基礎研究 (長谷部信行)

    2018   柴村英道, 月出章, 内藤雅之

     View Summary

    暗黒物質探索の研究では大型TPC技術が重要であり、その精度向上が必須である。最近は大型のTPCが数多く開発されているが、いづれも「電子的阻止能」と「電子的線エネルギー付与」を混同されている。この2つは値は、大きく異なると考えられ、検出精度に影響があると考えられる。そこで、我々は電子的阻止能と電子的線エネルギー付与の違いを検討し、数少ない実験値と比較し、どの程度差異が生じるかを評価した。数十keVの低エネルギー領域入の射粒子に対して、気体Arと気体Xeの阻止能と核的消光因子を、Lindhardの理論に基づいて計算した。そして、投影飛程に対して空間分布を求め、電子的阻止能と電子的線エネルギー付与の差異を評価した。実験値との比較から、低エネルギー領域においてはLindhardの理論の方が、概ね正しそうであることが分かった。Lindhard理論に基づいて導出した電子的阻止能と電子的線エネルギー付与の差異は、入射エネルギーが5 [keV]にて5倍程度、電子的線エネルギー付与が大きいため、従来の電子的阻止能ではなく、電子的線エネルギー付与から気体TPCでの飛跡の励起分布予想を行い、検証していく必要があることが明らかになった。

  • 高性能キセノンガンマ線分光計の開発 ―気体中のラドンのガンマ線計測と地震予知―

    2017  

     View Summary

    Coplanar電極を用いた気体電離箱の開発を行った。気体電離箱は、通常、放射線と検出媒体との相互作用の位置に対するパルス波高の依存性を除去するために、陽極と陰極の間にFrischグリッドを挿入する。しかしながら、グリッドは機械的な強度が弱いために製作や取り扱いが難しく、機械的振動に敏感で回路雑音が増加するなどの欠点があり、特に大面積では影響が大きい。そこで、従来型のFrish Grid型の平行平板型ガス電離箱、Grid電極を有しないCoplanar型の平行平板型ガス電離箱及びCoplanar型円筒型ガス電離箱を開発した。Coplanar電極の幾何学的形状をいろいろ変えて、得られるエネルギー分解能の違いを計測した。エネルギー分解能の達成目標としては、238U(4.21 MeV)と235U(4.40 MeV)のα線ピークを6σで分離することができることとした。即ち、78 keV (200 keV ÷ 6× 2.35 = 78 keV in FWHM)のエネルギー分解能を目標とした。Coplanar電極とは、アノード電極上にバイアスの異なる電極(電子の収集電極CAと非収集電極NCA)を交互に形成したもので、二つの電極に誘起される電荷の差を取ることで、相互作用の位置に依存しないパルス波高を得るものである。これまでにCZT半導体検出器に適用されているが、気体電離箱での研究例は少ないため、本研究により実用化を目指す。実用化ができれば、ウランなどの核燃料物質のα放出核の散逸、地震に伴って放出されるラドンの検出、環境放射能のモニターなど広い分野での応用が可能となる。特に、大容量高密度キセノン電離箱及び波形信号のデジタル処理と組み合わせることでマイクロフォニックスを大幅に低減した信頼性の高い計測システムが構築できると期待している。まず、アノード電極として、上述の3種類の形状で電極幅、電極間隔が異なるCoplanar電極を製作し、特性試験を実施した。その結果、正規分布状のα線の波高スペクトルが得られ、Frischグリッドと同様の効果があることを実証した。初めに、封入したガスは、取り扱いの容易なPRガス(Ar+CH4(10%))を用いて特性を調べた。線源としては237 𝑁𝑝, 241𝐴𝑚, 244 𝐶𝑚の3種のα線の混合線源を用いた小型のCoplanar型電離箱を作製し,最適な電極形状を決定する実験を実施した。3種類の小型Coplanar電極としてSpiral型、Circle型、Parallel型を作成した。電極間隔は、0.5mmと1.0mmである。得られたエネルギー分解能の結果を表1に示す。実験条件としては、Cathode電圧は -800V、この時の Cathode-Anode間の電場は~553V/cmである。Parallel型よりもCircle型やSpiral型の方が良い分解能が得られた。&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;    表1.電極構造の違いによるエネルギー分解能の比較 エネルギー分解能 238Np 241Am 244Cm Parallel 0.5mm 136 keV(2.85%) 121 keV(2.20%) 126keV(2.17%) Parallel 1.0mm 138 keV (2.88%) 113 keV(2.06%) 104 keV(1.79) Circle 1.0 mm 107 keV(2.24%) 86 keV(1.56%) 79 keV(1.37%) Spiral 1.0 mm 110 keV(2.31%) 92 keV(1.68%) 83 keV(1.43%) &nbsp;次に、大型Spiral型において電極幅と電極間隔を変化させた実験結果について述べる。上記のSpiral型電極において, 電極幅を2mmから1mmに,電極間隔を1mmから2mmに変更した。変更前と変更後で実験を行い, 得られたエネルギー分解能を表2に示す。この時の最適Cathode電圧は-1200V, 最適Bias電圧は100Vと120Vである。電極の線幅(2㎜→1㎜)と線間(1㎜→2㎜)を変更したときのエネルギー分解能は、244Cmの5.81MeVのα線に対して、分解能は 109 keV から74 keV に改善された。&nbsp;表2.Spiral型電極版(線幅1㎜線間2㎜)の平行平板型ガス電離箱のエネルギー分解能の比較 エネルギー分解能 237Np 241Am 244Cm Spiral電極(変更前) 129 keV (2.69%) 120 keV (2.18%) 109 keV (1.88%) Spiral電極(変更後) 110 keV (2.32%) 102 keV (1.86%) 74 keV (1.27%) &nbsp;これまでの一連の実験は、封入ガスとしてPRガスを使用したが、分解能の向上のためにW-値の小さなキセノンガスに変更した。実際には電子のドリフト速度を速くして、計数率を高めるためにCH4ガスを混入させた。その実験結果を表3に示す。この表からわかるように大幅なエネルギー分解能の改善が得られた。&nbsp;表3.Spiral型電極版(線幅1㎜線間2㎜)の平行平板型ガス電離箱のエネルギー分解能の比較 エネルギー分解能 237Np 241Am 244Cm Ar+CH4(10%) 110 keV (2.32%) 102 keV (1.86%) 74 keV (1.27%) Xe+CH4(0.66%) 76 keV (1.59%) 69 keV (1.25%) 59 keV (1.0%) &nbsp;大型の平行平板型キセノン電離箱の開発として、目標の分解能を達成することができた。自然界に放出される可能性のあるα線放射体を識別することが可能な分解能を得ることができた。振動に強いことからラドンを計測することによる地震予知などの計測として外部に設置する環境モニターとして使用することができる。更に大きな振動が起きたときは、現在進めているキセノンガス電離箱の波形信号のデジタル処理により対応できるものと考えている。&nbsp;

  • 月物質の絶対年代及び化学組成の高精度分析装置の開発

    2013  

     View Summary

    月物質の絶対年代及び化学組成の高精度分析装置の開発岩石の元素分析装置として能動型蛍光X線分析装置の焦電素子を利用したX線発生装置の基礎開発・研究を中心に進めた。X線発生強度の高輝度化に向けて、パラメーター(ガス種、ガス圧、電極間距離ほか)について、基礎データを取得して、市販のX線発生装置の20倍以上の高輝度化に成功した。さらに、小型軽量・低電力・高輝度化が実現すれば、可搬・簡易型化学分析装置として、実験室だけでなる野外で試料の元素分析装置として広く利用できるものと期待している。能動型蛍光X線分光計AXS: 月面に着陸して地質ユニットの元素組成を計測することは、宇宙科学、地質学的観点から必要不可欠である。能動的にX線を発生する装置XRGとシリコンドリフト検出器を蛍光X線検出器として、それらを組み合わせて能動型蛍光X線分光計AXSを構成する。X線発生装置は、焦電結晶LiTaO3をペルチェ素子で加熱・冷却して3)、X線を発生させる。本研究開発では、AXSのX線発生部を中心に進め、短時間にできるだけ多くの岩石試料を高性能で分析できるようにXRGの高輝度化に力点を置いた。X線発生装置XRG: 一般に、X線発生法としては、(A)144Cmなど&#61537;線源を励起源、(B)熱陰極型真空管であるX線管を励起源、(C)焦電結晶LiTaO3を加熱・冷却することでX線を発生させる励起源、が挙げられる。項目(A)の宇宙に放射性物質を持ち出すことは日本では困難である。項目(B)は高電圧電源が必要であり大きな電力(10W以上)が必要となる。項目(C)では、焦電素子を利用することで高圧電源が不要、かつ低電力で比較的高輝度のX線励起源が実現する。本AXSの特徴としては、高エネルギー分解能(~130eV @Fe-K&#61537;)を有することから元素の同定能力が高く、小型・省電力(3kg, 6W)である。X線発生装置に高圧電源が不要かつ放射性物質の励起源を使用しないので放射能汚染もなく、計測時のみX線を発生できる特徴を有する。■焦電素子型X線発生器XRGの基礎実験と試作焦電結晶型X線発生装置としてAMPTEK社のCOOL-Xが市販されているが、現存する機器では十分なX線強度を得られないために、希少元素の組成を求めるにことは難しい。そこで本研究では、焦電素子を利用したX線発生装置の高輝度化を目標とする。市販品(AMPTEC:COOL-X)の50倍以上にX線発生強度を増大する事を目標とする。第一段階として10倍以上を目標とした。焦電素子の寸法、標的電極構造、ガス種(乾燥空気、乾燥窒素、アルゴン、酸素)、ガス圧(10~50 mTorr)、常温から約120℃までの加熱、高温から常温までの冷却時間などをパラメータとして、実験を実施した。まず、高輝度化に向けたパラメータの最適条件を決める実験を行った。それら一連の実験を実施するための真空チェンバーの製作した。各種実験の結果、市販の装置と比較して約20倍のX線強度が達成できた。今後、熱伝導の大きなLiTaO3素子やLiNbO3素子、標的電極Cu/Moなどに変更して、更なる高輝度化へ試みる予定である。これら一連の実験結果については、その都度、国際会議や学会等で講演発表してきた。2014年度中に、X線発生装置の高輝度化に関する論文を2編投稿予定である。

  • 固体キセノンを用いた多目的放射線検出器開発のための放射線物性の基礎研究

    2013  

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     本研究の課題は、固体キセノンの放射線物性、即ちW値、電子・空孔それぞれの移動速度等を放射線による信号計測から決定する。ここでは、キセノン固体成長のための低温技術及び固体成長制御技術の習熟を平行平板型電離箱を用いて試みてきた(2012年応用物理学会で報告)。放射線の信号計測には、固体が結晶状態になるまで長期間の温度制御が必要であること、また、電離箱にはFrisch gridを電極間に挿入することが必要だが、これを固体内に挿入することは非常に難しいために、電離箱をLuke型の電極で実現することとした。 固体結晶の成長を、(1)最初に固体を作成し、(2)これを生成して結晶化する、という順序で研究を進めてきたが、(1)は成功したが、(2)に関しては長期間(~2週間)の温度コントロールに適した制御装置が現在有してないので、今後の課題である。これに代えて約50時間かけてゆっくりと温度及びガス圧を制御しながら固体成長を行うと、シンチレーション光の一部を取り出せる程度に透明な固体成長には成功した。ただし、放射線によって作られたイオン対の電子を電極に効率よく輸送できる程の透明度の高い結晶成長には至っていない。しかしながら、上記のどちらかの方法で固体成長が出来たとしても、Luke型の電離箱でどのような信号が捉えられるのか予め動作状態を知ることが重要で、これを気体電離箱としてLuke型電極を設計製作して、動作状態を先ず測定して来た。 平行平板電極の一つをカソードとし、金属板電極を用いる。一方アノード電極はストリップ型電極とし、ストリップを一本置きに接続し2種類の電極として使用する。一方のストリップでは電子を収集してその全電荷を計測し(A1)、他方のストリップでは、残留陽イオンの影響を計測する(A2)。電離箱は、先ず高真空とし、希ガス(ここではPRガスを使用)を約3気圧充填する。計測ではカソード上に設置したα線源からのアルファー線による電離現象をアノード電極で観測する。観測ではカソードに負の高圧を印加し、アノードのA1とA2の間にはA1に電子が集まるようにA2に負のバイアスを印加する。収集電子の全電荷はA1からの信号からA2からの信号を差し引き、陽イオンの影響を除去して求める。このようにしてアルファー線のエネルギー観測が可能なことが現在確認されたところである。従来使用されていたFrisch Grid型電離箱とほぼ同程度の性能が得られてた(2013応用物理学会で発表)。

  • パルス型中性子発生器と組み合わせた高速核分光器の開発

    2011  

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    月・惑星表層物質の元素組成は、表面だけでなく内部物質へのプローブでもあり、月の形成とその後の進化を知る上で非常に重要な観測量である。蛍光X線分光法や核分光法は、宇宙機の軌道上からの遠隔探査や月面走行車でのその場観測で、月・惑星物質を構成する元素分析方法として大変有力な手段である。元素組成の定量分析を行うために、強度の弱い太陽X 線、銀河宇宙線を励起源とする遠隔探査から、能動型蛍光X線分光装置、能動型核分光装置によるその場観測へと移り、より精度の高い測定が要求されることになるだろう。SELENE-2の搭載機器候補として能動型核分光装置AGSの搭載は、重量や電力の制約から見送ることになり、AGSは将来のミッション機器として今後も検討・開発を進めることになった。そこで本研究では、軽量・小電力型化学分析装置として高性能・能動型蛍光X線分析装置AXSが適当であると判断して、基礎開発を進めていくことに変更した。この研究班は、早稲田大学、韓国、米国、ドイツとの共同研究である。 能動型蛍光X線分光装置AXSとしては、軽量・小電力のX線発生装置XRGとして焦電結晶を用い、一方蛍光X線検出器としてはSilicon Drift Detector (SDD)使用して構成することになった。特に、XRGとしては焦電素子のX線源を用いてAXSの月惑星探査機の搭載機器に向けた基礎開発を行う。小型軽量化と省電力化の実現、および予想される温度環境での特性の維持を実証する。AXSは、元素の濃度に依存するが、主要元素:Mg, Al, Si, Ca, Ti, Fe,マイナー元素:Na, K, P, S, Cl, Cr, Mn, トレース元素:Ni 等の元素濃度5%以下の精度で測定できることを目標とする。 そこで、本年度は、分析用の真空チェンバーの作成、分析試料の表面の粗さに関する分析精度への影響、X線照射の入射角度と出射角度の元素分析精度への影響、X線強度変動と元素分析精度への影響について調べた。 また、高輝度(市販の数倍~10倍)の発生装置の開発、元素分析精度の温度依存性、X線強度と消費電力、希薄気体の密封法、ガスの種類とはX線発生強度、X線強度と焦電素子の種類などについての基礎研究、特に軽量及び省電力化に関連した高輝度・高エネルギー分解能のX線計測が短時間で実施できるシステムの開発に着手した。

  • LIBSを利用した月・惑星の元素分布の探査~次世代元素分析システムの開発~

    2010   唐牛 譲, 長岡 央, 北澤克樹

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    題目:LIBSを利用した月・惑星の元素分布の探査~次世代分析システムの開発~ 内容:Laser-Induced Breakdown Spectroscopy (LIBS)は近年、米国の火星探査(Chemistry&Camera)を筆頭に、元素定量分析法と して注目を集めている。(1)離れた所にあるターゲットの測定が可能であり、(2)レーザーでアブレーションすることで、宇宙風化の 影響を取り除くことができる。また、(3)即座に複数の元素の定量分析をすることが可能、(4)装置全体がシンプルな構造でありコン パクト、などの利点から、日本においても次期月着陸探査機にLIBS装置の搭載が検討されている。しかし、その分析精度や絶対濃 度 の校正法、また地球外惑星環境での測定には未だ多くの解決すべき問題点が存在している。そこで本研究では、それらの問題点 を検証し、LIBSの月惑星探査への適応可能性を検討した。

  • 中性子を利用した低エネルギーキセノン反跳核の電離・発光過程の研究

    2010   宮島 光弘, 草野 広樹, 石川 智裕

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    本研究では,キセノン反跳核による電離・発光収量を測定するための装置の準備および較正を行った。キセノンを用いた暗黒物質探索実験においてキセノン反跳核による信号は重要であり,本研究では,2.8気圧の気体キセノンを用いてキセノン反跳核の基礎物性値を得ることを目的としている。はじめに,キセノンガスを封入して中性子ビームを入射させるための検出器を設計・製作した。検出器内には,1インチ角の光電子増倍管を9個設置し,中性子により反跳核を発生させる領域と,発生した電子により比例蛍光を起こす領域を作り,適切な電場を印加できるようにした。次に,検出器内に設置する光電子増倍管の量子効率および利得の較正を,241Amからの5.49MeVのアルファ線を用いて行った。さらに,241Amからの59.5keVのガンマ線を用いて,検出器の光収率の較正を行った。また,散乱された中性子を検出するための液体シンチレータ(BC501A)について,発光波形による中性子・ガンマ線の弁別試験を行い,弁別条件を最適化した。並行して,5.49MeVのα線による電離・発光収量の測定を,広範囲の密度(0.12-1.2 g/cm3)にわたり行った。低エネルギーキセノン反跳核と5.49MeVのα線では,電離密度が近い値をとることが指摘されており,反跳核の理解に役立つものと考えられる。無電場での発光量は,約0.6g/cm3までは密度に対して一次関数的に減少したが,それ以上では傾向の変化が見られた。高密度下でのシンチレーション過程を理解するため,シンチレーション光子数と電離電子数を同時測定し,それらの相関を0.12-1.0g/cm3の各密度で求めた。結果,電子イオン対の再結合過程における変化に起因する消光過程の存在が示唆された。

  • 高密度キセノン検出器の放射線物性的研究  -エネルギー分解能を中心として-

    2009  

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    暗黒物質探査・二重ベータ崩壊探索・MeVγ線イメージングなどの最先端の研究で用いられる放射線検出器の媒質としてキセノンが注目されている。一方で、キセノンの基礎物性には未解明な点が多く、それらを把握することは検出器開発の基礎として極めて重要である。特に、気体から液体にかけてエネルギー分解能が密度と共に急激に変化することが知られており、そのメカニズムの解明は急務である。本年度は、気体から液体にかけてのエネルギー分解能の変化を解明するため、影響を及ぼす一つの要因である高密度状態でのシンチレーションの消光作用を重点的に研究した。この消光作用は、0.15 g/cm3以上の気体キセノンにて発現することが分かっていたが、どのような消光過程が働いているのかは明らかではなく、エネルギー分解能に与える影響についてほとんど研究されてこなかった。そこで、消光率の密度依存性を取得し、消光過程のモデルに対して比較・検討することを目指し、実験を実施した。再結合発光過程における電子イオン対からシンチレーション光子への変換効率(量子効率)が再結合発光過程の消光率と等しく、シンチレーション光子数と電離電子数の電場変化からこの量子効率が測定可能であることに着目した。過去に開発を行った実験装置を用いて、電場を変化させ、5.49MeVのアルファ線によって生成されるシンチレーション光子数と電離電子数の同時測定を行い、0.1~0.6 g/cm3の広範囲な密度領域にわたり量子効率を測定した。 実験結果は、0.15 g/cm3までの密度領域において、量子効率がほぼ100%であり、それ以上の密度で減少する傾向を示し、消光作用が働いていることをはっきりと示していた。さらに、キセノンのクエンチング過程として知られる励起原子同士の衝突、励起分子同士の衝突を仮定し、量子効率の密度依存性にこれらのモデルをフィッティングしたところ、励起分子同士の衝突で密度依存性をよく説明することができた。ただし、このフィッティング結果から予想される液体キセノン(3 g/cm3)のクエンチング効率は、実験結果と大幅な違いがあることがわかった。今後、より高密度で、より精度の良い量子効率の測定を行うことで、気体から液体にかけて消光効率がどのように変化するのかを明らかにし、エネルギー分解能の密度変化に解釈を加えたいと考えている。

  • 高密度キセノン電離箱のエネルギー分解能問題の解明

    2008  

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    キセノン電離箱は、シンチレーション発光と電子・イオン対の同時観測が可能なことから、これを利用し、天文学、惑星科学、素粒子物理学、医学的応用において革新的検出器が相次いで開発されている。近年、最も注目を集めている放射線検出器の一つであり、その基礎物性を探求することは極めて意義深い。キセノンを高密度化し、臨界点付近に達するとエネルギー分解能が悪化していく。一方で、一イオン対を生成するのに必要な平均エネルギー(W値)は減少するとの報告があり、統計的にはエネルギー分解能が向上することが期待される。この矛盾は、さらに高密度な液体キセノン検出器でも観測されているが未解明であり、エネルギー分解能問題と呼ばれている。我々は、エネルギー分解能の悪化が、密度揺らぎによるものだと予測しており、電離電子数とシンチレーション光子数に関係性があると考えている。本研究では、エネルギー分解能問題に密度揺らぎの観点からアプローチするために、1.低密度でのシンチレーション光子数の絶対測定、2.臨界点周辺で電離電子数及びシンチレーション光子数の同時測定、を平行して行った。以下では、進捗状況を述べる。1:キセノンガスのシンチレーション光子数については基準とすべき値が存在しない。我々は、アルファ線源を用いて点光源を作り、一励起子を生成するのに必要な平均エネルギー(Wex値)を34.1eVと決定した。2:臨界点を超える、およそ1g/cm3までの高密度化が可能であり、MgF2製の窓を持ち、内部にアルファ線源が固定された一対の平行平板電極を有するチェンバーを設計・製作した。 2において製作したチェンバーを用いた実験が現在進行中である。4月現在、キセノンガス純度確認のために、ドリフト速度の測定、lifetimeの測定などの予備実験を行っている段階であり、5月中旬には実験を開始する予定である。

  • 中性子照射法による月面土壌・岩石の微量元素分析

    2008  

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    将来の月探査ミッションにおいて、表面探査車にガンマ線分光計を搭載して月表層の元素組成を定量化することで、月の科学の発展に、また月資源利用の貴重な資料として大きく貢献できる。月面の自然ガンマ線発生機構は、銀河宇宙線と月物質との核相互作用で生成した中性子によってガンマ線が発生する。しかし、この自然発生のγ線強度は弱く、検出可能な元素種も限られている。そこで中性子発生器を用いて能動的に中性子を生成して元素分析をすることで、従来の宇宙線を利用するガンマ線分光法ではなしえなかった微量元素を含む様々な元素を高精度かつ効率的(短時間)で計測が可能となる。 本研究では、初めに中性子放射化分析法を実際に月岩石試料に適用し、その有用性を確認した。中性子放射化分析では、原子炉からの熱中性子を利用した中性子捕獲反応により発生するガンマ線を、Ge検出器で測定し元素分析を行った。その結果、数100 mgという少量の試料から主要・微量元素合わせて約30種類もの元素を高確度・高精度で同時定量することができた。月面上の中性子源としてD-T中性子発生管を用い14MeV中性子を発生させる。加速方式はコッククロフト・ウォルトン型とし、出力電圧100kV、ビーム電流10mAを目標とする。毎秒109個の中性子を発生させた場合、月地表からのガンマ線フラックスは銀河宇宙線誘導の場合と比較して1000倍の強度が実現可能である。実用化に向けて電源部の小型軽量化を検討しており、現時点では2kV・1mAの小型高圧電源の試作が完成し、その見通しを得ることができた。

  • 宇宙線中の超重核観測装置の展開と格納機構の開発

    2007   晴山慎, 小平聡

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     銀河宇宙線中の同位体を含めた超重核の元素組成の詳細測定は、宇宙線の起源や年齢、銀河物質の歴史、粒子加速や輸送機構等の解明に有力な情報をもたらす。しかし、宇宙線中に占める超重核成分のフラックスは極めて小さく、観測には数m2にわたる大面積の宇宙粒子線検出器が求められる。本研究ではこの宇宙粒子線検出器の宇宙空間への展開機構について検討を行なうと共に、高性能な宇宙粒子線検出器の開発を中心に行った。展開機構については、1つの宇宙粒子線検出器を20cm*20cm*5cm程度にモジュール化し、それらを2次元アコーディオン方式によって数m2以上に展開する機構が最も我々の宇宙実験における信頼性と確実性が得られることが分かった。 高性能な宇宙粒子線検出器の開発については、曝露面積の拡張性と粒子識別能力の高さからCR-39固体飛跡検出器に着目した。しかしながら従来のCR-39では原子番号の低い重イオンに対して高感度過ぎるために、超重核検出においては不向きであった。そこで本研究では、既に基礎開発を終えているCR-39-DAP共重合体検出器について、その重合のキュアリングサイクルおよび混合比率の最適化ついて詳しく検討した。また並行してこれまで基礎研究を行なってきたBP-1ガラスの組成の最適化や構造の一様性について研究を行った。 CR-39-DAPについては、均一性・粒子識別能力が共に優れているBARYOTRAKを基材に、DAP樹脂を一定間隔割合で重合を行った。特に、重合度を上げる工夫として、通常のCR-39のキュアリングサイクルに加えて、+120度の加熱処理を行った。また、通常、重合促進剤として使用するIPPは3.3%添加するが、IPPを3.3, 5, 7%に変えたときの重合度と感度の変化について調べた。490 MeV/uのSiビームを照射し、その応答感度を調べたところ、+120度に加熱処理をした場合は、DAP混合比率の増加と共に線形的に応答感度を低下させることができた。これによりCR-39-DAP重合の最適化についてある程度の目処をつけることが出来た。 BP-1ガラスについては、一連の重イオンビーム照射によって、固体飛跡検出器としての性能を確認した。一様性を高めたBP-1ガラスの製法について、オハラ(株)と議論しながら進めており、またBP-1を超える感度を有する超高感度ガラスについても検討を始めている。今後1年で優れた粒子識別能力を有してなおかつ超重核領域あるいは低エネルギー領域の粒子識別に威力を発揮する高性能固体飛跡検出器が開発できる見込みを立てることが出来た。

  • Xe中における放射線エネルギー損失過程とXeの密度効果

    2006  

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    気体・液体Xeに放射線を照射したときには、放射線のエネルギーによって電子・イオン対とシンチレーション光が発生する。Xeを用いた放射線検出器は、天文学、惑星科学、素粒子物理学、医学的応用において第一線で活躍しており、このような放射線の密度変化を知ることは非常に重要である。 W値はひとつの電子・イオン対を作るのに必要な平均エネルギーであり、Ws値は光子をひとつ作るのに必要な平均エネルギーをあらわす。これらは放射線のエネルギーには依存しない量である。W値の場合、気体Xe・液体Xeではそれぞれ、21.9eV、15.6eVであることが知られているが、気体から液体への密度の上昇と共にどのように変化してゆくかということは、実験・理論の両者共にまだ確立していない。 本研究ではグリッド付の平行平板型電離箱を作成し、キセノンを0.1~1 MPa充填し、Np237、Am241、Cm244が放出するα線を計測しその電離電子数を測定した。実験結果では0.1~1 MPaのXe圧力変化があってもW値の変化は2い%以内であり、このような圧力範囲では実験精度内で変化がないことが明らかになった。さらに、高密度での実験を行うためにはキセノンガスの高純度化が特に重要である。これまでに循環型純化装置を製作しその動作試験を行っている。気体Xe(1 MPa)、液体XeのWs値はそれぞれ34.3 eV、13.8 eVであることが知られており、密度と共にWs値が減少すると考えるのが普通である。しかしながらこれまで我々が得たWs値は密度と共に上昇するという矛盾した結果が得られている。今回これまでのデータを再評価した結果、Wsは密度と共に上昇することに間違いがないことを確認した。放射線のエネルギーがシンチレーション発光に変化する過程は単純ではないと言える。

  • 宇宙線中の超鉄核同位体検出器と解析システムの開発

    2005  

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    CR-39にDAP樹脂を重合した共重合体樹脂はその重合割合により検出できるZ/β閾値が可変であるか、また可変であればどの重合割合が超鉄核観測に最適であるかについて検討を行った。DAPの重合割合を11種類(0%~100%)まで変えた樹脂に、放医研のHIMAC重イオン加速器から500MeV/n以下のエネルギーの酸素核からキセノン核までの重イオンを照射し、化学エッチング処理は7N NaOH溶液を用いて70℃と90℃の2種類の温度で1~18時間行った。その結果、DAPの重合割合が高くなるほど系統的に重イオンに対する応答関係は変化し、重合割合により検出できるZ/β閾値が可変であることが分かった。また、我々の要求するZ/β>30に検出閾値を持つものとして、DAPの重合割合が約50%の共重合体樹脂であることが分かった。CR-39は高い質量分解能を有しており低Z/β粒子に対して高感度であるが、放射線照射時の温度や真空度に対する感度応答の依存性が大きく、必ずしも暴露環境が厳しい宇宙空間における宇宙線観測に適しているとは一概には言えない。一方、1988年に開発されたバリウムリン酸塩ガラス(BP-1)はその飛跡生成機構がCR-39と異なる為、温度依存性が少なく真空状態においても応答する。しかし検出できるZ/β閾値が50以上であり低Z/β粒子に対する感度応答はCR-39に比べて悪い。更に、BP-1における超鉄核に対する質量分解能は、現状では隣り合う同位体を弁別するには至っていない。そこで本研究において、宇宙環境に強いというBP-1の利点を生かし、ガラス組成の最適化を行いZ/β閾値を30程度までに引き下げ尚且つ質量分解能がZ=30で0.20amu程度を持つような高性能BP-1ガラス固体飛跡検出器の開発をオハラ(株)と協力し取り組み始めた。BP-1は日本では製造されていない全く新しい素材である為、まずオリジナルの組成を持ったBP-1を製造できることが目標となるが、オリジナルとほぼ同一の組成をもつBP-1の製造に成功した。

  • 気球実験による宇宙線中の鉄核同位体の観測-気球環境下でのCR-39検出器の性能評価-

    2005  

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    CR-39は放射線照射時の温度や真空度に対する感度応答の依存性が大きいことが知られている。この為、放射線照射時の温度に対する感度応答の変化を調べた。-60℃~+60℃まで10℃刻みに温度コントロールしたチェンバーにCR-39を固定し、放医研のHIMAC重イオン加速器から供給されたFeの110 MeV/nを照射した。この結果、照射時温度が-30℃以下では安定に動作することが明らかになったので、気球高度では安定に宇宙線観測を行うことができることが分かった。更にCR-39の真空度に対する感度応答の変化について調べた。大気雰囲気で圧力を0.1~760Torrまで変化・保持し、Feの424 MeV/nを照射した。気球環境下では高度30km~40kmの間において9Torr~2Torr程度の圧力変化がある。今回の結果によると、9Torrと2Torr間における飛跡生成感度の変化は約30%程度あり、観測環境下では圧力を一定に保つ必要があることが分かった。しかしながら圧力減少に対応して感度応答が高Z/β側にシフトしている可能性があることから、圧力のコントロールによりZ/β検出閾値を任意に変化させてCR-39を使用できる可能性が見出された。

  • 宇宙粒子線中の超重核成分の高精度観測

    2002   鷹野 正利, 宮地 孝, 岡田宏之

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    研究成果の概略  高エネルギー宇宙粒子線中の超鉄核成分は、強度が極めて少ないが、鉄族元素とは異なる元素合成過程を得て作られることから、それらの観測は宇宙線の起源や伝播を知るうえで貴重な情報を与えてくれる。超鉄核の観測例は殆どない。特に、1)アクチニド元素、2)超鉄核元素の同位体(質量数A<130)、について正確に求めることが重要である。HNX(Heavy Nuclei eXplorer)探査機は、1)のU/Thや超ウラン元素を含めたアクチニド元素をカバーする宇宙線観測装置である。超鉄核の絶対強度が小さいために、視野角をできるだけ広く持つ大面積検出器が必要である。更に、核電荷を高精度で同定する事が検出器の性能として要求される。そこで、浜松ホトニクスと協力して大面積シリコン検出器(92×92mm、380μm thickness)の開発と実用性を検証した。電荷・質量の決定精度に大きな影響を与える検出器の厚みムラを、放射線医学総合研究所のHIMAC重イオン加速器からの高エネルギーAr,Xeビームを用いて調べた。その結果、有感面積全体の厚さの非一様性は0.7%以下であることが得られ、宇宙線中のアクチニド元素まで高精度で弁別することができる事が明らかとなり、HNX計画に十分使用できることが実証できた。HNX計画では、上述2)の同位体の情報は得られない。そこで、将来の宇宙線実験のために、鉄族から質量A<130の同位体について、高分解能で計測する観測装置、A)Si検出器ΔE×Eテレスコープ、B)固体飛跡検出器CR-39、の開発に着手した。A)については長期安定型の肉厚大面積Si(Li)の開発を始めた。B)については、従来、元素弁別は実施されているが、同位体弁別は試みられてない。そこで2002年度からCR-39を利用した実験に取り組んでいる。鉄の同位体(A=56、55)の照射を行った。満足いく結果とはいい難いが、改良することでA~100まで質量弁別できる見通しがついた。その結果は、2003年7月の第28回宇宙線国際会議で発表予定である。

  • 宇宙線中の超鉄核観測のための大面積シリコン検出器の開発

    2000   菊池 順, 小林 正規

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     宇宙線の起源や伝播を知るうえで超鉄核の観測は貴重な情報を与えてくれる。そこで我々は2004年に打ち上げが予定されているHNX(Heavy Nuclei eXplorer)探査機による超鉄核観測を視野にいれた地上の基礎開発実験を行なってきた。HNXプロジェクトのENTICE(Energetic Trans-Iron Composition Experiment)実験は、未だかつてないダイナミックな超鉄核領域を観測するプロジェクトで、シリコン検出器、チェレンコフ検出器、荷電粒子飛跡検出器からなり、観測する電荷範囲はNe(Z=10)~Bi(Z=83)以上、エネルギーは500MeV/n~3.5GeV/nの領域を微分エネルギースペクトル、3.5GeV/n以上の領域の積分エネルギースペクトルを高精度で観測する。この観測計画では、超鉄核の絶対強度がたいへん低いために、視野角をできるだけ広く持ち、電荷を高精度で分解する事が要求される。 そこで、(株)浜松ホトニクスと協力して開発した大面積シリコン検出器(92×92mm、380μm thickness)の実用性を検証した。これは、PIN型検出器としては従来の4インチを大幅に上回る世界最大の6インチのPIN型検出器である。また、肉厚についても、PIN型としては国内で最厚の500μmの2倍となる1mm厚の検出器の製作に成功した。両検出器の実用性の立場から電荷・質量の決定精度に大きな影響を与える検出器の厚みムラを、放射線医学総合研究所のHIMAC重イオン加速器からの高エネルギーXeビームを用いて調べた。 大面積シリコン検出器では、中心部の不純物濃度の増加による性能劣化を当初懸念していたが、中心付近で分解能が劣化する現象は見られず、放射線検出器として十分な性能が確保できた。位置による出力の揺らぎについては、当初の目標とはしてなかったが半値幅で約1.18%(380μm厚)、約0.56%(1mm厚)という結果が得られた。よって、肉厚の検出器を利用すれば全ての元素について高精度で弁別することが可能である事が明らかとなった。以上、試作した大型・肉厚シリン検出器のビーム実験結果から、HNX計画に十分使用できることが実証できた。

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Overseas Activities

  • 宇宙放射線科学と月惑星科学の研究の加速と展開

    2010.09
    -
    2011.09

    フランス   トールーズ大学

    ポルトガル   コインブラ大学

    ドイツ   グーテンベルグ大学マインツ