Abstract
The isotopes have been studied with (), (), and () reactions to extract the nuclear level densities (NLDs) and -ray strength functions (GSFs) of these nuclei below the neutron separation energy by means of the Oslo method. The experimental NLDs for all three nuclei demonstrate a trend compatible with the constant-temperature model below the neutron separation energy while also being in good agreement with the NLDs of neighboring Sn isotopes, obtained previously with the Oslo-type and neutron evaporation experiments. The extracted microcanonical entropies yield entropy of a valence neutron in both and . Moreover, the deduced microcanonical temperatures indeed suggest a clear constant-temperature behavior above MeV in and above MeV in . We observe signatures for the first broken neutron pairs between 2 and 4 MeV in all three nuclei. The GSFs obtained with the Oslo method are found to be in good agreement below the neutron threshold with the strengths of extracted in the () Coulomb excitation experiments.
2 More- Received 7 March 2023
- Accepted 27 June 2023
DOI:https://doi.org/10.1103/PhysRevC.108.014315
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