Abstract
The neutron capture cross sections of the stable cerium isotopes 136, 138, 140, and 142 have been measured relative to that of gold by means of the activation method. The samples were irradiated in a quasistellar neutron spectrum for kT=25 keV using the (p,nBe reaction near threshold. Variation of the experimental conditions in different activations and the use of different samples allowed for the reliable determination of corrections and the evaluation of systematic uncertainties. The resulting stellar cross sections can be given with uncertainties between 3% and 7%. The present data for and are the first experimental information in this mass region of relevance for p-process studies to our knowledge, whereas the new cross section allowed to resolve a previous discrepancy. The experimental results are complemented by a set of calculated cross sections for all cerium isotopes from to as well as for , , and . The improved cross sections were used in an updated s-process analysis of the Ce-Pr-Nd region that included the small branchings at and . The consequences of the resulting s abundances are discussed with respect to isotopic anomalies in meteoritic neodymium as well as for the r- and p-process residuals. © 1996 The American Physical Society.
- Received 10 October 1995
DOI:https://doi.org/10.1103/PhysRevC.53.1397
©1996 American Physical Society