Streamlined Monte Carlo simulation of environmental gamma-ray backgrounds for radiation detector sensitivity comparisons

In recent research to compare detection sensitivities of gamma spectrometers applied to in situ and field laboratory scenarios, the authors lacked background data for comparable detection sensitivity calculations. To overcome this, experimental measurements and Monte Carlo modeling of terrestrial gamma radiation were undertaken. Inspired by Vojtyla’s research to reduce the computing burden of modeling bremsstrahlung from lead surfaces, this related approach defines a gamma-ray surface source representing emission of background gamma-rays from the earth. This work presents a surface source based on the 40K, 137Cs, uranium, and thorium content of Hanford soil, and compares modeled backgrounds to experimental in situ gamma measurements.