Lawrence Berkeley National Laboratory

Thermal neutron capture gamma rays were measured for all stable elements 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 isotopic data from ENSDF and the original papers and were evaluated. The resulting accurate new levels 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 fits to the level schemes. The new elemental datasets will be the basic input to an IAEA database for prompt gamma activation analysis, a chemical method of elemental analysis. The new isotopic sets will be provided for updating the thermal neutron capture datasets of ENSDF.