Simulations of material-dependent detector responses for airborne gamma-ray spectroscopy

This work aims to create a library of predicted detector responses used for real-time background estimation during airborne gamma-ray spectroscopy. The simulated spectra are a function of naturally occurring radioactive potassium, uranium, and thorium (KUT) and radioactive daughter products which are present in terrestrial-based materials. Self-attenuation within these materials varies, such that the gamma spectra emitted from the surfaces can differ, despite all having KUT origins. This study also compares various simulated detector responses among materials to determine if some could be accurately scaled from another across reasonable helicopter altitudes and orientations relative to the ground. Results show that materials with comparable sample thicknesses can be scaled consistently across altitude. This work allows for efficient background estimation via aggregation of simulated detector responses in real time.