Diverse collective excitations in Er-159 up to high spin

Research output: Contribution to journalArticle


A spectroscopic investigation of the gamma decays from excited states in Er-159 has been performed to study the changing structural properties exhibited as ultrahigh spins (I > 60 (h) over bar) are approached. The nucleus of Er-159 was populated by the reaction Cd-116(Ca-48, 5n gamma) at a beam energy of 215 MeV, and the resulting gamma decays were studied using the Gammasphere spectrometer. New rotational bands and extensions to existing sequences were observed, which are discussed in terms of the cranked shell model, revealing a diverse range of quasiparticle configurations. At spins around 50 (h) over bar, there is evidence for a change from dominant prolate collective motion at the yrast line to oblate non-collective structures via the mechanism of band termination. A possible strongly deformed triaxial band occurs at these high spins, which indicates collectivity beyond 50 (h) over bar. The high-spin data are interpreted within the framework of cranked Nilsson-Strutinsky calculations.


  • M. Mustafa
  • J. Ollier
  • J. Simpson
  • M. A. Riley
  • E. S. Paul
  • X. Wang
  • A. Aguilar
  • M. P. Carpenter
  • I. G. Darby
  • D. J. Hartley
  • R. V. F. Janssens
  • F. G. Kondev
  • T. Lauritsen
  • P. J. Nolan
  • M. Petri
  • J. M. Rees
  • J. P. Revill
  • S. V. Rigby
  • C. Teal
  • J. Thomson
  • C. Unsworth
  • S. Zhu
  • Hailiang Ma
  • Tajdar Mufti
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Sciences
Original languageEnglish
JournalPhysical Review C (Nuclear Physics)
Issue number5
Publication statusPublished - 2011
Publication categoryResearch

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Mathematical Physics (Faculty of Technology) (011040002)