Investigation of Lunar Shallow Subsurface Water Content and Soil Elemental Composition via Active Neutron Detection

The detection of planetary water and soil elements is a pivotal area of research due to its implications for understanding celestial bodies. Within the realm of planetary sampling missions, attention is predominantly directed toward the shallow surface layers, typically to a depth of 1 m. This paper examines the Moon as a case study, employing Monte Carlo simulations to introduce an active detection methodology that integrates high-energy neutron pulse generators with neutron and gamma detectors. Simulations were made of the albedo neutrons and prompt gamma counts after mitigating the interference of secondary neutrons and gamma rays, which result from the interaction between galactic cosmic rays and the lunar surface.