TY - JOUR
T1 - Determining the absolute abundances of natural radioactive elements on the lunar surface by the kaguya gamma-ray spectrometer
AU - Kobayashi, S.
AU - Hasebe, Nobuyuki
AU - Shibamura, E.
AU - Okudaira, O.
AU - Kobayashi, M.
AU - Yamashita, N.
AU - Karouji, Y.
AU - Hareyama, M.
AU - Hayatsu, K.
AU - D'Uston, C.
AU - Maurice, S.
AU - Gasnault, O.
AU - Forni, O.
AU - Diez, B.
AU - Reedy, R. C.
AU - Kim, K. J.
PY - 2010/7
Y1 - 2010/7
N2 - 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.
AB - 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.
KW - Gamma-ray spectrometer
KW - K
KW - Moon
KW - Natural radioactive elements
KW - SELENE (Kaguya)
KW - Spatial response function
KW - Th
KW - U
UR - http://www.scopus.com/inward/record.url?scp=78650178236&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78650178236&partnerID=8YFLogxK
U2 - 10.1007/s11214-010-9650-2
DO - 10.1007/s11214-010-9650-2
M3 - Article
AN - SCOPUS:78650178236
SN - 0038-6308
VL - 154
SP - 193
EP - 218
JO - Space Science Reviews
JF - Space Science Reviews
IS - 1-4
ER -