High resolution neutron capture and transmission measurements on {sup 137}Ba and their impact on the interpretation of meteoric barium anomalies
- Oak Ridge National Laboratory, Oak Ridge, Tennessee37831-6354 (United States)
We have made improved measurements of the neutron capture and total cross sections for {sup 137}Ba over a sufficiently wide range of energies so that the reaction rate at s-process temperatures (kT=6{endash}23 keV) can be determined solely from the data. These rates are crucial for the interpretation of recently discovered anomalies of Ba isotopes in silicon carbide grains from the Murchison meteorite. Recent stellar models of the s process are in agreement with the meteoric anomaly data for Ba only if the {sup 137}Ba(n,{gamma}) reaction rate is 20{percent} larger than the previously accepted rate. Our reaction rates at s-process temperatures are in agreement with the extrapolated reaction rate from the most recent previous measurement. Hence, our results uphold, and place on much firmer footing, the discrepancy between recent stellar models of the s-process and the meteoric anomaly data. {copyright} {ital 1998} {ital The American Physical Society}
- OSTI ID:
- 627578
- Journal Information:
- Physical Review, C, Vol. 57, Issue 4; Other Information: PBD: Apr 1998
- Country of Publication:
- United States
- Language:
- English
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