Neutron capture cross sections of {sup 186}Os, {sup 187}Os, and {sup 189}Os for the Re-Os chronology
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan)
- Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, O-okayama, Tokyo 152-8550 (Japan)
- Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles, Campus de la Plaine, CP226, B-1050 Brussels (Belgium)
- Nuclear Research and Consultancy Group, P.O. Box 25, NL-1755 ZG Petten (Netherlands)
- CEA/DAM Ile-de-France, DPTA/Service de Physique Nucleaire, BP 12, F-91680 Bruyeres-le-Chatel (France)
Discrete as well as continuum {gamma}-ray energy spectra from the neutron capture by {sup 186}Os, {sup 187}Os, and {sup 189}Os have been taken for the first time at 5{<=}E{sub n}{<=}90 keV by an anti-Compton NaI(Tl) spectrometer. The detection of a weak discrete {gamma}-ray, about 0.5% of total {gamma}-ray strength, demonstrates the high sensitivity of the present measurement. The energy spectra enabled us to accurately determine the reaction cross sections with a small systematic uncertainty. Based on the new cross sections, we reestimate on the basis of a careful reaction cross section calculation the correction factor F{sub {sigma}} for the neutron capture on the 9.75-keV first excited state in {sup 187}Os as a function of stellar temperature, as required to derive the age of the galaxy within the Re-Os chronology.
- OSTI ID:
- 21061938
- Journal Information:
- Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 2 Vol. 76; ISSN 0556-2813; ISSN PRVCAN
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CAPTURE
CORRECTIONS
CROSS SECTIONS
ENERGY SPECTRA
EXCITED STATES
GAMMA RADIATION
GAMMA SPECTRA
GAMMA SPECTROSCOPY
ISOTOPE DATING
KEV RANGE
NAI DETECTORS
NEUTRON REACTIONS
OSMIUM 186
OSMIUM 186 TARGET
OSMIUM 187
OSMIUM 187 TARGET
OSMIUM 189
OSMIUM 189 TARGET
SENSITIVITY