Correction for neutron self-shielding and gamma-ray self-absorption in prompt-gamma activation analysis for large and irregularly shaped samples

Prompt-gamma activation analysis (PGAA) is a useful method to determine the elemental composition of bulky samples, where non-destructivity, representativity, and high metrological quality are of great importance. Voluminous samples significantly attenuate both the exciting neutron beam and the emerging gamma radiation within the sample. We have developed a generally applicable correction for the neutron self-shielding and gamma-ray self-absorption effect for large and irregularly shaped samples, based on digital geometry data and Monte Carlo simulations. The numerical correction gives results that agree well with those from destructive sampling.