Elemental composition effects on self-absorption for photons below 100Â keV in gamma-ray spectrometry

The influence of elemental composition in the self-absorption phenomenon is observed. The effective atomic number (Zeff) is used to explain this influence for energies below 100 keV. Monte Carlo simulations based on MCNPX and GESPECOR are used to demonstrate the separate impact of Zeff and density ρ on the self-absorption for a given extended sample. Results obtained by simulation are in good agreement with those obtained by the transmission method.