A Universal Approach to Neutron Activation Analysis of Complex Substances

A new promising approach to the development of neutron activation isotope- element analysis is considered, which consists in dividing all radioisotopes formed during neutron activation of a complex substance into groups according to the duration of their half-life and sequentially conducting their isotope-element analysis based on the measured gamma and beta radiation spectra of these radioisotopes during their decay. Identification and determination of the specific activity of radioisotopes formed during activation is carried out using a modified sequential subtraction method. At the same time, it is shown that using scintillation gamma- and beta-spectrometers of increased resolution, the proposed method makes it possible to perform isotope-element analysis of complex substances consisting of an arbitrary set of stable elements with their isotopes. It is shown that using 8 groups of radioisotopes formed during activation with half-lives from 0,8 s to 10 days, it is possible to analyze complex substances containing 222 stable isotopes belonging to 66 stable elements if all the elements being determined contain natural concentrations of isotopes. But even if the concentrations of isotopes in the elements of the analyzed substance do not correspond to the natural distribution (which is possible if the substance has been subjected to isotopic separation or intense irradiation with ionizing radiation), then in this case it is possible to determine 91 stable isotopes belonging to 66 elements.