Title :
Neutron production in the lunar subsurface from galactic cosmic rays
Author :
Ota, Shuya ; Sihver, Lembit ; Kobayashi, Shingo ; Hasebe, Nobuyuki
Author_Institution :
Waseda Univ., Tokyo, Japan
Abstract :
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/cm2. However, our calculation showed 10-20% higher values in the deeper region.
Keywords :
Monte Carlo methods; cosmic ray energy spectra; cosmic ray interactions; lunar interior; neutron production; 3D Monte Carlo simulation code; Apollo 17 lunar neutron probe experiment; BESS measurements; GCR spectra; PHITS; equilibrium neutron density profiles; galactic cosmic rays; lunar subsurface neutron production; nuclear interaction models; Alpha particles; Cosmic rays; Extraterrestrial measurements; Gamma rays; Moon; Neutrons; Nuclear measurements; Particle production; Probes; Protons;
Conference_Titel :
Aerospace Conference, 2010 IEEE
Conference_Location :
Big Sky, MT
Print_ISBN :
978-1-4244-3887-7
Electronic_ISBN :
1095-323X
DOI :
10.1109/AERO.2010.5447009
