Decay of Neutron-Rich Mn Nuclides and Deformation of Heavy Fe Isotopes

M. Hannawald; T. Kautzsch; A. Wöhr; W. B. Walters; K.-L. Kratz; V. N. Fedoseyev; V. I. Mishin; W. Böhmer; B. Pfeiffer; V. Sebastian; Y. Jading; U. Köster; J. Lettry; H. L. Ravn; the ISOLDE Collaboration

doi:10.1103/PhysRevLett.82.1391

Decay of Neutron-Rich Mn Nuclides and Deformation of Heavy Fe Isotopes

M. Hannawald, T. Kautzsch, A. Wöhr, W. B. Walters, K.-L. Kratz, V. N. Fedoseyev, V. I. Mishin, W. Böhmer, B. Pfeiffer, V. Sebastian, Y. Jading, U. Köster, J. Lettry, H. L. Ravn, and the ISOLDE Collaboration

Phys. Rev. Lett. 82, 1391 – Published 15 February 1999

Abstract

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

Received 13 March 1998

DOI:https://doi.org/10.1103/PhysRevLett.82.1391

Authors & Affiliations

M. Hannawald¹, T. Kautzsch¹, A. Wöhr², W. B. Walters³, K.-L. Kratz¹, V. N. Fedoseyev⁴, V. I. Mishin⁴, W. Böhmer¹, B. Pfeiffer¹, V. Sebastian⁵, Y. Jading⁶, U. Köster⁷, J. Lettry⁶, H. L. Ravn⁶, and the ISOLDE Collaboration⁶

¹Institut für Kernchemie, Universität Mainz, D-55099 Mainz, Germany
²Instituut voor Kern- en Strahlingsfysica, University of Leuven, B-3001 Leuven, Belgium
³Department of Chemistry, University of Maryland, College Park, Maryland 20742
⁴Institute of Spectroscopy, Russian Academy of Sciences, RUS-142092 Troitzk, Russia
⁵Institut für Physik, Universität Mainz, D-55099 Mainz, Germany
⁶CERN, CH-1211 Geneva 23, Switzerland
⁷Physik-Department, TU München, D-85748 Garching, Germany