Validation of k0 neutron activation analysis

Neutron activation analysis using single comparator method (k0NAA method) is being used for obtaining elemental concentrations in a variety of matrices. Gold is used as the single comparator instead of multielement standards. This method needs some input parameters like k0, f, the thermal to epicadmium neutron flux ratio, Q0, the ratio of resonance integral to thermal neutron cross section, and ε, absolute efficiency of detector for the gamma line used. The method should be validated by primary standards. High resolution gamma ray spectrometry was used for radioactive assay of the activation products. The accuracy and precision were evaluated by measuring the elemental concentrations of various primary standards of different matrices from USGS, IAEA and NIST. The measured concentrations were reported within ± 1-15% from certified values where as the precision from quadruplicate measurements was 2-15%. (author)