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arXiv · nucl-ex/9812008

Decay of neutron-rich Mn nuclides and deformation of heavy Fe isotopes

M. Hannawald·T. Kautzsch·A. Woehr·W. B. Walters·K. -L. Kratz·V. N. Fedoseyev·V. L. Mishin·W. Boehmer·B. Pfeiffer·V. Sebastian·Y. Jading·U. Koester·J. Lettry·H. L. Ravn·the ISOLDE Collaboration
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Abstract

The use of chemically selective laser ionization combined with beta-delayed neutron counting at CERN/ISOLDE has permitted identification and half-life measurements for 623-ms Mn-61 up through 14-ms Mn-69. The measured half-lives are found to be significantly longer near N=40 than the values calculated with a QRPA shell model using ground-state deformations from the FRDM and ETFSI models. Gamma-ray singles and coincidence spectroscopy has been performed for Mn-64 and Mn-66 decays to levels of Fe-64 and Fe-66, revealing a significant drop in the energy of the first 2+ state in these nuclides that suggests an unanticipated increase in collectivity near N=40.

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M. Hannawald, T. Kautzsch, A. Woehr, W. B. Walters, K. -L. Kratz, V. N. Fedoseyev, V. L. Mishin, W. Boehmer, B. Pfeiffer, V. Sebastian, Y. Jading, U. Koester, J. Lettry, H. L. Ravn, the ISOLDE Collaboration. 1998-12-21. Decay of neutron-rich Mn nuclides and deformation of heavy Fe isotopes. https://doi.org/10.1103/physrevlett.82.1391

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