Isomer-delayed gamma-ray spectroscopy of neutron-rich 166Tb

L. A. Gurgi, P. H. Regan, P. A. Söderström, H. Watanabe, P. M. Walker, Zs Podolyák, S. Nishimura, T. A. Berry, P. Doornenbal, G. Lorusso, T. Isobe, H. Baba, Z. Y. Xu, H. Sakurai, T. Sumikama, W. N. Catford, A. M. Bruce, F. Browne, G. J. Lane, F. G. KondevA. Odahara, J. Wu, H. L. Liu, F. R. Xu, Z. Korkulu, P. Lee, J. J. Liu, V. H. Phong, A. Yagi, G. X. Zhang, T. Alharbi, R. J. Carroll, K. Y. Chae, Zs Dombradi, A. Estrade, N. Fukuda, C. Griffin, E. Ideguchi, N. Inabe, H. Kanaoka, I. Kojouharov, T. Kubo, S. Kubono, N. Kurz, I. Kuti, S. Lalkovski, E. J. Lee, C. S. Lee, G. Lotay, C. B. Moon, I. Nishizuka, C. R. Nita, Z. Patel, O. J. Roberts, H. Schaffner, C. M. Shand, H. Suzuki, H. Takeda, S. Terashima, Zs Vajta, S. Kanaya, J. J. Valiente-Dobòn

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


This short paper presents the identification of a metastable, isomeric-state decay in the neutron-rich odd-odd, prolate-deformed nucleus 166Tb. The nucleus of interest was formed using the in-flight fission of a 345 MeV per nucleon 238U primary beam at the RIBF facility, RIKEN, Japan. Gamma-ray transitions decaying from the observed isomeric states in 166Tb were identified using the EURICA gamma-ray spectrometer, positioned at the final focus of the BigRIPS fragments separator. The current work identifies a single discrete gamma-ray transition of energy 119 keV which de-excites an isomeric state in 166Tb with a measured half-life of 3.5(4) μs. The multipolarity assignment for this transition is an electric dipole and is made on the basis internal conversion and decay lifetime arguments. Possible two quasi-particle Nilsson configurations for the initial and final states which are linked by this transition in 166Tb are made on the basis of comparison with Blocked BCS Nilsson calculations, with the predicted ground state configuration for this nucleus arising from the coupling of the v(1-/2)[521] and π(3+/2) Nilsson orbitals.

Original languageEnglish
Title of host publicationND 2016
Subtitle of host publicationInternational Conference on Nuclear Data for Science and Technology
EditorsPeter Siegler, Wim Mondelaers, Arjan Plompen, Franz-Josef Hambsch, Peter Schillebeeckx, Stefan Kopecky, Jan Heyse, Stephan Oberstedt
PublisherEDP Sciences
ISBN (Electronic)9782759890200
StatePublished - Sep 13 2017
Event2016 International Conference on Nuclear Data for Science and Technology, ND 2016 - Bruges, Belgium
Duration: Sep 11 2016Sep 16 2016

Publication series

NameEPJ Web of Conferences
ISSN (Print)2101-6275
ISSN (Electronic)2100-014X


Conference2016 International Conference on Nuclear Data for Science and Technology, ND 2016


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