The calculation of self-shielding correction factors for large samples in 241Am-Be isotopic neutron source.

In the present study, it is aimed to calculate neutron self-shielding correction factors for cylinder sample geometry using different methods in the literature in the application of k0-NAA standardization method with 241Am-Be isotopic neutron source. These correction factors are important in calculating the accurate concentration values for large samples with a high neutron absorption cross-section in the application of the k0-NAA method. In order to see the validity of the applied theoretical and experimental methods, the obtained concentration values are given comparatively with respect to the known Mn concentrations. The mean concentration difference ranges from -3.4% to -9.7%. The thermal neutron self-shielding correction depends on all elements in the sample that absorb thermal neutrons. In k0-NAA applications with large samples, although time-consuming, it is recommended to use the experimental methods after calculating the necessary parameters with the help of samples with known composition.