The differential scattering parameters of different types of materials in Compton energy region for nuclear applications

Linear attenuation coefficient, mass attenuation coefficient, differential scattering cross sections, effective atomic number (Z(eff)), effective electron density are the parameters used to determine interaction of X-/gamma rays with any material. These parameters depend on photon energy and chemical composition of the studied material. The scattering process is a convenient method for material characterization as it contains less doses than transmission. In the present study, a theoretical estimation based on the scattering of radiation was used to calculate total molecular mass differential scattering coefficients (TMMDSC) of different types of materials for Cs-137 and Co-60 radioisotopes covering Compton energy region and for varying scattering angles. For this aim, differential Compton and Rayleigh scattering cross sections (based on Klein-Nishina and Thomson formula) were used for different momentum transfer values. Using the data obtained, practical fit equations were determined to calculate Klein-Nishina and Thomson cross sections for studied momentum transfer range. Using these equations TMMDSC of any material can be easily estimated. Furthermore, Z(eff)s of the selected materials were studied in the same momentum transfer range based on Rayleigh to Compton scattering ratio for the first time. Values of Z(eff), which is one of the most important parameter to distinguish or identify multi-element materials, was compared to those of mean atomic numbers and it was found that the relative differences can reach up to 76.54%.