New measurement of neutron capture resonances of 209Bi
| dc.creator | Domingo-Pardo, C. | |
| dc.date | 2006-10-26 | |
| dc.date.accessioned | 2026-07-07T12:00:00Z | |
| dc.date.available | 2026-07-07T12:00:00Z | |
| dc.description | The neutron capture cross section of Bi209 has been measured at the CERN n TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of gamma-rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. Gamma-ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because Bi209 is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by alpha-decays. In the relevant stellar range of thermal energies between kT=5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At this low temperature an important part of the heavy Pb-Bi isotopes are supposed to be synthesized by the s-process in the He shells of low mass, thermally pulsing asymptotic giant branch stars. With the improved set of cross sections we obtain an s-process fraction of 19(3)% of the solar bismuth abundance, resulting in an r-process residual of 81(3)%. The present (n,gamma) cross-section measurement is also of relevance for the design of accelerator driven systems based on a liquid metal Pb/Bi spallation target. | |
| dc.description | 10 pages, 5figures, recently published in Phys. Rev. C | |
| dc.identifier | https://arxiv.org/abs/nucl-ex/0610040 | |
| dc.identifier | http://arxiv.org/abs/nucl-ex/0610040 | |
| dc.identifier | Phys.Rev.C74:025807,2006 | |
| dc.identifier | doi:10.1103/PhysRevC.74.025807 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/206763 | |
| dc.subject | Nuclear Experiment | |
| dc.title | New measurement of neutron capture resonances of 209Bi | |
| dc.type | text |