Year: 2015
Type: article
Abstract: Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and $247(73)\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$ have been discovered in the heavy $^{254}\mathrm{Rf}$ nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the ${K}^{\ensuremath{\pi}}={8}^{\ensuremath{-}}$, ${\ensuremath{\nu}}^{2}(7/{2}^{+}[624],9/{2}^{\ensuremath{-}}[734])$ two-quasineutron and the ${K}^{\ensuremath{\pi}}=1{6}^{+}$, ${8}^{\ensuremath{-}}{\ensuremath{\nu}}^{2}(7/{2}^{+}[624],9/{2}^{\ensuremath{-}}[734])\ensuremath{\bigotimes}{8}^{\ensuremath{-}}{\ensuremath{\pi}}^{2}(7/{2}^{\ensuremath{-}}[514],9/{2}^{+}[624])$ four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter $N=150$ isotones. The four-quasiparticle isomer is longer lived than the $^{254}\mathrm{Rf}$ ground state that decays exclusively by spontaneous fission with a half-life of $23.2(1.1)\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state.
Source: Physical Review Letters
Authors: H. M. David, J. Chen, D. Seweryniak, F. G. Kondev, J. M. Gates, K. E. Gregorich, I. Ahmad, M. Albers, M. Alcorta, B. B. Back, B. Baartman, P. F. Bertone, L. A. Bernstein, C. M. Campbell, M. P. Carpenter, C. J. Chiara, R. M. Clark, M. Cromaz, D. T. Doherty, G. D. Dracoulis, N. E. Esker, P. Fallon, O. R. Gothe, J. P. Greene, P. T. Greenlees, D. J. Hartley, K. Hauschild, C. R. Hoffman, S. S. Hota, R. V. F. Janssens, T. L. Khoo, J. Konki, J. T. Kwarsick, T. Lauritsen, A. O. Macchiavelli, P. R. Mudder, C. Nair, Y. Qiu, J. Rissanen, A. M. Rogers, P. Ruotsalainen, G. Savard, S. Stolze, A. Wiens, S. Zhu
Institutions: Argonne National Laboratory, Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory, University of Maryland, College Park, University of Edinburgh, Australian National University, University of Jyväskylä, United States Naval Academy, Centre National de la Recherche Scientifique, Institut National de Physique Nucléaire et de Physique des Particules, University of Massachusetts Lowell
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2235907656