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Neutron physics of the Re/Os clock. III. Resonance analyses and stellar (n,γ) cross sections ofOs186,187,188
- Source :
- Physical Review C. 82
- Publication Year :
- 2010
- Publisher :
- American Physical Society (APS), 2010.
-
Abstract
- Neutron resonance analyses have been performed for the capture cross sections of Os-186, Os-187, and Os-188 measured at the n_TOF facility at CERN. Resonance parameters have been extracted up to 5, 3, and 8 keV, respectively, using the SAMMY code for a full R-matrix fit of the capture yields. From these results average resonance parameters were derived by a statistical analysis to provide a comprehensive experimental basis for modeling of the stellar neutron capture rates of these isotopes in terms of the Hauser-Feshbach statistical model. Consistent calculations for the capture and inelastic reaction channels are crucial for the evaluation of stellar enhancement factors to correct the Maxwellian averaged cross sections obtained from experimental data for the effect of thermally populated excited states. These factors have been calculated for the full temperature range of current scenarios of s-process nucleosynthesis using the combined information of the experimental data in the region of resolved resonances and in the continuum. The consequences of this analysis for the s-process component of the Os-187 abundance and the related impact on the evaluation of the time duration of galactic nucleosynthesis via the Re/Os cosmochronometer are discussed.
- Subjects :
- Physics
Nuclear reaction
Nuclear and High Energy Physics
010308 nuclear & particles physics
Resonance
01 natural sciences
7. Clean energy
Nuclear physics
Neutron capture
13. Climate action
Nucleosynthesis
0103 physical sciences
Neutron
Nucleon
s-process
010303 astronomy & astrophysics
Stellar evolution
Subjects
Details
- ISSN :
- 1089490X and 05562813
- Volume :
- 82
- Database :
- OpenAIRE
- Journal :
- Physical Review C
- Accession number :
- edsair.doi...........ac1a01ef203423805d4db363173acedd