New Catalog of Neutron Capture γ Rays for Prompt Gamma Activation Analysis

Abstract

Thermal neutron capture gamma rays were remeasured for all stable elements, except helium, at the guided neutron beam facility in Budapest. Energies, relative intensities and partial production cross-sections were determined with high precision for about 14, 000 gamma rays of 82 elements. The new experimental data were supplemented with isotopie data from ENSDF and the original papers and were evaluated. The resulting accurate new level and decay schemes comprise 35, 000 gamma-ray transitions. The new database is practically complete for light nuclei, hence capture cross-sections could be inferred from the measured partial gamma-ray production cross-sections. Precise neutron separation energies were also deduced from the fits to level schemes. The new elemental datasets will be the basic input to a new IAEA database for prompt gamma activation analysis, a chemical method of elemental analysis. The new isotopie sets will be provided for updating the thermal neutron capture datasets of ENSDF.