Energy distributions of multiple backscattered photons in materials

Abstract

Backscattering of gamma photons from a material is of fundamental importance in radiation shielding, industrial and medical applications, radiation dosimetry, and non-destructive testing. In Compton scattering, incident photons undergo multiple scatterings within the material (target) before exiting. Gamma photons continue to soften in energy as the number of scatterings increases in a thick target; in other words, the energy of gamma photons decreases as the scatterings increase in case of a thick target and results in the generation of singly and multiply scattered events. In this work, the energy distribution of backscattered gamma photons with backscattering intensity and energy probabilities were calculated by using the Monte Carlo method for metallic, biological, and shielding materials with various thicknesses of slab geometry. The materials under study were targeted with gamma photons of 0.279, 0.662, 1.250, and 2.100 MeV energies. In addition, the energy distributions of multiply scattered gamma photons were studied for materials with infinite geometry. The results are presented and discussed in detail by comparing with other Monte Carlo calculations.