Abstract
Total radiative thermal neutron-capture -ray cross sections for the W isotopes were measured using guided neutron beams from the Budapest Research Reactor to induce prompt and delayed rays from natural and isotopically-enriched tungsten targets. These cross sections were determined from the sum of measured -ray cross sections feeding the ground state from low-lying levels below a cutoff energy, , where the level scheme is completely known, and continuum rays from levels above , calculated using the Monte Carlo statistical-decay code dicebox. The new cross sections determined in this work for the tungsten nuclides are b and b; b and b; b and b; and, b and b. These results are consistent with earlier measurements in the literature. The W cross section was also independently confirmed from an activation measurement, following the decay of W, yielding values for that are consistent with our prompt -ray measurement. The cross-section measurements were found to be insensitive to choice of level density or photon strength model and only weakly dependent on . Total radiative-capture widths calculated with dicebox showed much greater model dependence; however, the recommended values could be reproduced with selected model choices. The decay schemes for all tungsten isotopes were improved in these analyses. We were also able to determine new neutron-separation energies from our primary -ray measurements for the respective () compounds: W [ keV]; W [ keV]; W [ keV]; and, W [ keV].
8 More- Received 30 October 2013
- Revised 1 December 2013
- Corrected 27 January 2014
DOI:https://doi.org/10.1103/PhysRevC.89.014606
©2014 American Physical Society
Corrections
27 January 2014