Nuclides activities estimation algorithm for scintillation spectra with taking into account sample density variation

It is known that a variation of the density of a space-distributed radioactive sample (source) influences the shape of the nuclides radiation spectrum. An algorithm for nuclides activities estimation has been developed, which takes into account variations of sample density. This algorithm is based on the maximum likelihood method and includes a linear transformation between the vectors of the activities estimates for different densities. The algorithm developed does not depend on the type of ionizing radiation and requires substantially less volume of calibration data to be stored in comparison with the standard methods of taking into account a sample density. It needs only initial spectra of the nuclides radiation for single magnitude of sample density and a set of the transformation matrices for series of densities to be stored (authors). 2 refs