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Title: Isomer spectroscopy of neutron-rich 168Tb 103

In-flight fission of a 345 MeV per nucleon 238U primary beam on a 2 mm thick 9Be target has been used to produce and study the decays of a range of neutron-rich nuclei centred around the doubly mid-shell nucleus 170Dy at the RIBF Facility, RIKEN, Japan. The produced secondary fragments of interest were identified event-by-event using the BigRIPS separator. The fragments were implanted into the WAS3ABI position sensitive silicon active stopper which allowed pixelated correlations between implants and their subsequent β-decay. Discrete γ-ray transitions emitted following decays from either metastable states or excited states populated following beta decay were identified using the 84 coaxial high-purity germanium (HPGe) detectors of the EURICA spectrometer, which was complemented by 18 additional cerium-doped lanthanum bromide (LaBr 3) fast-timing scintillation detectors from the FATIMA collaboration. This paper presents the internal decay of a metastable isomeric excited state in the odd-odd nucleus 168Tb, which corresponds to a single proton-neutron hole configuration in the valence maximum nucleus 170Dy. These data represent the first information on excited states in this nucleus, which is the most neutron-rich odd-odd isotope of terbium (Z = 65) studied to date. Here, Nilsson configurations associated with an axially symmetric, prolate-deformed nucleus are proposedmore » for the 168Tb ground state the observed isomeric state by comparison with Blocked BCS-Nilsson calculations.« less
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Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Radiation Physics and Chemistry (1993)
Additional Journal Information:
Journal Name: Radiation Physics and Chemistry (1993); Journal Volume: 140; Journal Issue: C; Journal ID: ISSN 0969-806X
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
United Kingdom Science and Technology Facilities Council; USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; Gamma-ray spectroscopy and nuclear isomerism; Nuclear eneregy-level schemes; Possible two-quasiparticle configurations; Structure of neutron-rich radioisotopes
OSTI Identifier: