Abstract
The neutron capture cross sections of light nuclei () are important for -process scenarios since they act as neutron poisons. We report on measurements of the neutron capture cross sections of and , which were performed at the Karlsruhe 3.7 MV Van de Graaff accelerator via the activation method in a quasistellar neutron spectrum corresponding to a thermal energy of keV. Systematic effects were controlled by repeated irradiations, resulting in overall uncertainties of less than 3%. The measured spectrum-averaged data have been used to normalize the energy-dependent cross sections from the main data libraries JEFF-3.2, JENDL-4.0, and ENDF/B-VII.1, and a set of Maxwellian averaged cross sections was calculated for improving the -process nucleosynthesis yields in AGB stars and in massive stars. At keV, the new Maxwellian averaged cross sections of and are mb and mb, respectively. Both values are 20% lower than previously recommended. The effect of neutron poisons is discussed for nuclei with in general and for the investigated isotopes in particular.
- Received 11 January 2016
DOI:https://doi.org/10.1103/PhysRevC.93.055807
This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Published by the American Physical Society