Level structure above the 17+ isomeric state in 15269Tm83

B.S. Nara Singh, D.M. Cullen, M.J. Taylor, P.C. Srivastava, P. Van Isacker, O. Beeke, B. Dodson, David O'Donnell, U. Jakobson, T. Grahn, P.T. Greenlees, P.M. Jones, R. Julin, S. Khan, M. Leino, A.-P. Leppanen, S. Eeckhaudt, K. Mantyniemi, J. Pakarinen, P. PeuraP. Rahkila, J. Sarén, J. Sorri, J. Uusitalo, M. Venhart

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Excited states above the 17+ isomeric state in the proton-rich nucleus 152Tmwere established by employing the recoil-isomer tagging technique. Data were collected using the JUROGAM gamma-ray array and the GREAT spectrometer together with the recoil ion transport unit (RITU) gas-filled recoil separator and analyzed to identify the prompt and delayed γ decays from the levels in 152Tm. Shell-model calculations, either in a large valence space or in a reduced model space with five protons in the π0h11/2 orbital and one neutron in the ν1f7/2 orbital, agree with the observed energies of the yrast levels up to angular momentum J=21. The observation of near degeneracies in the energy spectrum can be attributed to specific components of the proton-neutron interaction. The isomeric decay of the 17+ level is not reproduced in the shell-model calculations as it arises from a delicate balance between hindrance due to seniority selection rules and enhancement due to configuration mixing.
Original languageEnglish
Article number024319
Number of pages11
JournalPhysical Review C
Issue number2
Publication statusPublished - 28 Aug 2018



  • electromagnetic transitions
  • isomer decays
  • lifetimes and widths
  • nuclear forces
  • nuclear spin and parity
  • shell model

Cite this

Nara Singh, B. S., Cullen, D. M., Taylor, M. J., Srivastava, P. C., Van Isacker, P., Beeke, O., ... Venhart, M. (2018). Level structure above the 17+ isomeric state in 15269Tm83. Physical Review C, 98(2), [024319]. https://doi.org/10.1103/PhysRevC.98.024319