Analysis of some Pb, Th and U compounds in terms of photon interaction, photon energy absorption and fast neutron attenuation

The effective atomic numbers of some compounds including Pb, Th and U as constituents have been calculated for total photon interaction (ZPIeff) and photon energy absorption (ZPEAeff) in the energy region from 1 keV to 20 MeV. It is also seen that the fast neutron removal cross-sections of these compounds have been calculated by using the MERCSF-N computer program. Effective atomic numbers ZPIeff of compounds have been calculated using two different methods in the continuous energy range and also a single value of ZPIeff has been obtained via XMuDat computer program. It is recommended that ZPEAeff should be used rather than ZPleff at the energies where significant differences occur between ZPleff and ZPEAeff when the interested physical quantity is the energy deposition. The obtained ZPIeff values using direct and interpolation methods agree well in the intermediate energy region where Compton scattering is predominant whereas in the low and high energy regions they do not agree. The ZPIeff values calculated by XMuDat were found to agree with the ones obtained using direct method in the low energy region where photoelectric absorption is predominant. Among the compounds, Th(NO3)4·5H2O, ThF4·4H2O, UO4·2H2O, Th(OH)4 and PbNO3 have higher values of fast neutron removal cross-sections, thus can be preferred as fast neutron absorber as well as high energy photon absorber.