Coulomb excitation of Na-29,Na-30: Mapping the borders of the island of inversion

M. Seidlitz*, P. Reiter, R. Altenkirch, B. Bastin, C. Bauer, A. Blazhev, N. Bree, B. Bruyneel, P. A. Butler, J. Cederkall, T. Davinson, H. De Witte, D. D. DiJulio, J. Diriken, L. P. Gaffney, K. Geibel, G. Georgiev, R. Gernhaeuser, M. Huyse, N. KestelootT. Kroell, R. Kruecken, R. Lutter, J. Pakarinen, F. Radeck, M. Scheck, D. Schneiders, B. Siebeck, C. Sotty, T. Steinbach, J. Taprogge, P. Van Duppen, J. Van de Walle, D. Voulot, N. Warr, F. Wenander, K. Wimmer, P. J. Woods, K. Wrzosek-Lipska

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Nuclear shell evolution in neutron-rich Na nuclei around N = 20 was studied by determining reduced transition probabilities, i.e., B(E2) and B(M1) values, in order to map the border of the island of inversion. To this end Coulomb-excitation experiments, employing radioactive Na-29,Na-30 beams with a final beam energy of 2.85 MeV/nucleon, were performed at REX-ISOLDE, CERN. De-excitation gamma rays were detected by the MINIBALL gamma-ray spectrometer in coincidence with scattered particles in a segmented Si detector. Transition probabilities to excited states were deduced. The measured B(E2) values agree well with shell-model predictions, supporting the idea that in the Na isotopic chain the ground-state wave function contains significant intruder admixture already at N = 18, with N = 19 having an almost pure two-particle-two-hole deformed ground-state configuration.

Original languageEnglish
Article number024309
Number of pages10
JournalPhysical Review C
Volume89
Issue number2
DOIs
Publication statusPublished - 19 Feb 2014

Keywords

  • NUCLEAR-DATA SHEETS
  • SHELL-MODEL
  • REGION
  • BEAM
  • SPECTROMETER
  • COLLECTIVITY
  • DEFORMATION
  • CHALLENGES
  • FRONTIERS
  • MINIBALL

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