Abstract
The -ray strength function and level density in the quasi-continuum of have been measured using bismuth germanate shielded Ge clover detectors of the STARLiTeR system. The Compton shields allow an extraction of the strength down to unprecedentedly low energies of keV. For the first time an enhanced low-energy -ray strength has been observed in the rare-earth region. In addition, for the first time both the upbend and the well-known scissors resonance have been observed simultaneously for the same nucleus. Hauser-Feshbach calculations show that this strength enhancement at low energies could have an impact of 2–3 orders of magnitude on the () reaction rates for -process nucleosynthesis.
- Received 15 July 2015
DOI:https://doi.org/10.1103/PhysRevC.93.034303
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