The s-process branchings at W-185 and Re-186

• Published in: The Astrophysical journal Vol. 366; p. 605
• Main Authors: Kaeppeler, F., Jaag, S., Bao, Z. Y., Reffo, G.
• Format: Journal Article
• Language: English
• Published: United States 01.01.1991
• Subjects: 640102 - Astrophysics & Cosmology- Stars & Quasi-Stellar, Radio & X-Ray Sources; ABUNDANCE; ACTIVATION ANALYSIS; BARYON REACTIONS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CAPTURE; CHEMICAL ANALYSIS; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DATA; DAYS LIVING RADIOISOTOPES; ELECTRON CAPTURE RADIOISOTOPES; ELEMENT ABUNDANCE; EVEN-ODD NUCLEI; EXPERIMENTAL DATA; GRAPHS; HADRON REACTIONS; HEAVY NUCLEI; INFORMATION; ISOMERIC TRANSITION ISOTOPES; ISOTOPES; MATHEMATICAL MODELS; MATHEMATICS; MINUTES LIVING RADIOISOTOPES; NEUTRON ACTIVATION ANALYSIS; NEUTRON DENSITY; NEUTRON REACTIONS; NUCLEAR REACTIONS; NUCLEI; NUCLEON REACTIONS; NUCLEOSYNTHESIS; NUMERICAL DATA; ODD-ODD NUCLEI; RADIOISOTOPES; RHENIUM 186; RHENIUM ISOTOPES; S PROCESS; STAR EVOLUTION; STAR MODELS; STATISTICS; SYNTHESIS; TABLES; TUNGSTEN 185; TUNGSTEN ISOTOPES
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1086/169596

The activation method is used to measure the stellar neutron capture rates of Re-185 and Re-187 at kT = 25 keV as 1677 + or - 65 and 1269 + or - 62 mbarn, respectively. The experimental setup and procedure are described, and the results are presented in tables and graphs. Also reported are calculations of the capture rates for the unstable isotopes, e.g., 597 + or - 85 mbarn for W-185 and 1775 + or - 265 mbarn for Re-186, again at kT = 25 keV. These results are then applied, using the classical method, to estimate the mean neutron density for the s-process nucleosynthesis branchings at W-185 and Re-186: n(n) = (4.1 + 1.2 or - 1.1) x 10 to the 8th/cu cm. 64 refs.