# Prompt and delayed $\gamma$ spectroscopy of neutron-rich $^{94}$Kr and observation of a new isomer

Abstract : Prompt and delayed γ -ray spectroscopy of the neutron-rich 94 Kr was performed, as part of the fission campaign at the ALTO facility of the IPN Orsay, using the fast-neutron-induced fission reaction 238 U ( n , f ) in combination with the ν -Ball array, a novel hybrid γ spectrometer for energy and lifetime measurements. Several new yrast and nonyrast transitions were observed for the first time, extending the previously known level scheme. Additionally, we report on the observation of a new short-lived isomer at 3444 keV with a half-life of 32(3) ns. The analysis of the Nilsson orbitals obtained from Gogny cranked Hartree-Fock-Bogoliubov calculations suggests a ( 9 − ) spin and an oblate deformation for this isomer corresponding to a two-quasineutron state, indicating an isomeric structure very similar to that of the neighboring isotones 96 Sr and 92 Se
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Contributor : Christelle Schmitt <>
Submitted on : Monday, January 4, 2021 - 2:58:48 PM
Last modification on : Wednesday, February 10, 2021 - 4:26:51 PM

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### Citation

R.-B. Gerst, A. Blazhev, N. Warr, J. Wilson, M. Lebois, et al.. Prompt and delayed $\gamma$ spectroscopy of neutron-rich $^{94}$Kr and observation of a new isomer. Physical Review C, American Physical Society, 2020, 102 (6), pp.064323. ⟨10.1103/PhysRevC.102.064323⟩. ⟨hal-03094623⟩

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