학술논문

ISOMER SPECTROSCOPY OF NEUTRON-RICH 165,167Tb.
Document Type
Article
Source
Acta Physica Polonica B. 2017, Vol. 48 Issue 3, p601-608. 8p.
Subject
*RADIOACTIVE nuclear beams
*EXCITED states
*ISOMERS
*SPECTRUM analysis
*NEUTRON beams
TERBIUM isotopes
Language
ISSN
0587-4254
Abstract
We present information on the excited states in the prolate-deformed, neutron-rich nuclei 165;167Tb100;102. The nuclei of interest were synthesised following in-flight fission of a 345 MeV per nucleon 238U primary beam on a 2 mm 9Be target at the Radioactive Ion-Beam Factory (RIBF), RIKEN, Japan. The exotic nuclei were separated and identified event-by-event using the BigRIPS separator, with discrete energy gamma-ray decays from isomeric states with half-lives in the Vs regime measured using the EURICA gamma-ray spectrometer. Metastable-state decays are identified in 165Tb and 167Tb and interpreted as arising from hindered E1 decay from the 7-/2[523] single quasi-proton Nilsson configuration to rotational states built on the 3-/2[411] single quasi-proton ground state. These data correspond to the first spectroscopic information in the heaviest, odd-A terbium isotopes reported to date and provide information on proton Nilsson configurations which reside close to the Fermi surface as the 170Dy doubly-midshell nucleus is approached. [ABSTRACT FROM AUTHOR]