view Abstract Citations (18) References (40) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Stellar (n, gamma ) Cross Section of the Unstable Isotope 163Ho and the Origin of 164Er Jaag, S. ; Kaeppeler, F. Abstract The stellar (n, y) cross section of the unstable isotope 163Ho (t½ = 4570 yr) has been experimentally determined relative to that of gold by means of the activation method. In the course of this experiment, a number of decay parameters for 164Ho have been remeasured and improved. A sample containing 6.62 x 1017 163Ho atoms was irradiated in a quasi-stellar neutron spectrum corresponding to a thermal energy of kT = 25 keV. This sample was produced from 162Er, and the remaining impurity was sufficient to determine the 162Er cross section simultaneously. For 163Ho, a stellar cross section of σv/vT = 2125±95 mbarn at kT = 30 keV was found as the sum of the partial cross sections feeding the ground and isomeric states in 164Ho. This value is of relevance for analyzing the abundance pattern in the s-process branchings at 163Dy and 163Ho that reflects the electron density during helium shell burning in low-mass stars. Publication: The Astrophysical Journal Pub Date: June 1996 DOI: 10.1086/177375 Bibcode: 1996ApJ...464..874J Keywords: NUCLEAR REACTIONS; NUCLEOSYNTHESIS; ABUNDANCES full text sources ADS |