A practical approach for estimation of thermal neutron self-shielding for quantification of REEs, Th and U in Egyptian monazite sand employing k₀-NAA

A practical approach has been developed to estimate the thermal neutron self-shielding correction of Egyptian monazite sand, a primary source of rare earth elements (REEs), thorium (Th) and phosphorus (P) with uranium (U) quantity, consequently, the k₀ Neutron Activation analysis (k₀-NAA) method can be used to accurately quantify the elemental content. Assessment of neutron self-shielding correction was based on the optimization of the mass-specific count rate mathematical relationship by practical treatments including the using of inert diluting substance namely silicon dioxide (SiO₂). It demonstrated that neutron self-shielding underestimated the elements' concentration in the sample by 59.2%. k₀-NAA method detected REEs at 56.48%, Th at 5.67%, U at 0.381%. The approach was evaluated using synthetic monazite and also compared with ICP-MS and theoretical calculations. The overall performance of the method proved to be acceptable.