Monte Carlo Simulation for Airborne Gamma Ray Spectrometry

The aerial measuring terrestrial gamma radiation from airborne platforms is a useful method for characterizing the radiation levels over large areas. Because of the advantage of Monte Carlo method, it is very suitable for simulation of gamma ray transport and interaction with media (soil, air, aircraft and detector), which offer alternative means of estimating detector response and calibration factors for airborne gamma ray spectrometry system. In this paper, the geometry equivalence method Monte Carlo method and simulation code for airborne gamma ray spectrometry are presented and validated, which overcome the difficulty of poor statistics of modeling the large-area-source and point-detector problem. It has been applied to investigate practical airborne gamma ray spectrometry system. The airborne spectrum of gamma ray from ground source and radioactive pads sources were simulated. The response of detector was calculated. The simulated results are accord with that of experiments. The simulated results are combined with experimental data to determine calibration factors of airborne gamma ray spectrometry system and quantitatively analyze aerial measuring data.