<bold>Data evaluation methods and improvements to the </bold>neutron-capture g <bold>-ray spectrum</bold>

Improved neutron-capture gamma-ray spectra, not only of interest to the nuclear structure and reactions communities, are needed in a variety of applied and non-proliferation programs. This requires an evaluation of the existing experimental capture-gamma data. Elemental neutron-capture data taken from direct measurements at the Budapest Reactor have been used to collate the Evaluated Gamma-ray Activation File, a database of capture gamma-ray cross sections. These cross sections are then compared to Monte Carlo simulations of gamma-ray emission following the thermal neutron-capture process using the statistical-decay code DICEBOX. The aim of this procedure is to obtain the total radiative neutron-capture cross section and confidently increase the number of levels and gamma rays that can be assigned to a given isotope in the neutron data libraries. To achieve these goals and provide as complete information as possible in the neutron data libraries, it is also necessary to remain current with recent advances in nuclear structure physics and ensure that the latest data in the Evaluated Nuclear Structure Data File has been taken into consideration. This way an optimal level scheme can be derived by comparison with simulations and available experimental data. New information derived from this study can then be used to improve the nuclear structure and reactions databases with more-complete level schemes, and indeed, provide reliable and accurate input to a variety of applications which require this information. Recent results from neutron capture on the stable tungsten isotopes W-182,W-183,W-184,W-186 are presented to illustrate the evaluation process.