Search for Weak Side Branches in the Electromagnetic Decay Paths of the 6526-keV 10+ Isomer in 54Fe

Paul Böhm, Yuliia Hrabar, Dirk Rudolph*, Pavel Golubev, Luis G. Sarmiento, Helena M. Albers, John T. Anderson, Michael A. Bentley, Michael P. Carpenter, Christopher J. Chiara, Patrick A. Copp, Ulrika Forsberg, Tianheng Huang, Heshani Jayatissa, Torben Lauritsen, Claus Müller-Gatermann, Xesus Pereira-Lopez, Walter Reviol, Darek Seweryniak, Sanna StolzeSivahami Uthayakumaar, Gemma L. Wilson, Jin Wu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


High-spin nuclear isomers in (Formula presented.) nuclei between doubly magic (Formula presented.) Ca and (Formula presented.) Ni provide an excellent testing ground for the nuclear shell model and questions related to isospin symmetry breaking in the vicinity of the proton drip line. The purpose of the present study is to investigate the possibility of weak electromagnetic decay branches along the decay paths of the 6526-keV (Formula presented.) isomer in (Formula presented.) Fe. The isomer was strongly populated by means of the fusion-evaporation reaction (Formula presented.) Mg((Formula presented.) Ar, (Formula presented.)) (Formula presented.) Fe. The Gammasphere array was used to detect (Formula presented.) -ray cascades emitted from the isomeric state. By means of (Formula presented.) coincidences, weak non-yrast decay branches can be discriminated, with the isomer’s half-life confirmed at (Formula presented.) ns. The yrast (Formula presented.)   (Formula presented.) cross-over transition was interrogated. The observations are compared with shell-model calculations.

Original languageEnglish
Article number116
Number of pages7
Issue number9
Publication statusPublished - 24 Aug 2023

Bibliographical note

Funding Information:
This research was funded in part by the Swedish Research Council (Vetenskapsrådet, VR 2016-3969 and VR 2022-3828), the Crafoord Foundation in Lund (Grant 20180630), the U.S. Department of Energy, Office of Science, Office of Nuclear Physics (Contract No. DE-AC02-06CH11357), and the UKRI Science and Technology Facilities Council under grant numbers ST/P003885/1 and ST/V001035/1.

Funding Information:
We would like to thank the ATLAS accelerator crew for their supreme efforts. This research used resources of ANL’s ATLAS facility, which is a U.S. Department of Energy Office of Science User Facility. The isotope(s) used in this research were supplied by the U.S. Department of Energy Office of Science by the Isotope Program in the Office of Nuclear Physics.

Publisher Copyright:
© 2023 by the authors.


  • electromagnetic transitions
  • nuclear isomer
  • nuclear shell model

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