Entropy in hot ^{161,162}Dy and ^{171,172}Yb nuclei
Abstract
The density of accessible levels at low spin in the (^3He,\alpha \gamma) reaction has been extracted for the ^{161,162}Dy and ^{171,172}Yb nuclei. The entropy of the even-odd and even-even nuclei has been deduced as a function of excitation energy, and found to reach a maximum of 15 k_B before neutron evaporation. The entropy of one quasi-particle outside an even-even core is found to be 1.70(15) k_B. This quasi-particle picture of hot nuclei is well accounted for within a simple pairing model. The onset of two, four and six quasi-particle excitations in the ^{162}Dy and ^{172}Yb nuclei is discussed and compared to theory. The number of quasi-particles excited per excitation energy is a measure for the ratio of the level energy spacing and the pairing strength.
Keywords
Cite
@article{arxiv.nucl-ex/9911011,
title = {Entropy in hot ^{161,162}Dy and ^{171,172}Yb nuclei},
author = {M. Guttormsen and A. Bjerve and M. Hjorth-Jensen and E. Melby and J. Rekstad and A. Schiller and S. Siem and A. Belic},
journal= {arXiv preprint arXiv:nucl-ex/9911011},
year = {2009}
}
Comments
19 pages, 11 figures