Abstract
The level scheme of Er-157 has been extended from a spin region where the nucleus behaves as a prolate rotor to a region where the spin is produced by the alignment of all or most of the available valence nucleons along the symmetry axis of a weakly deformed oblate shape. The level scheme was established at high spin using up to four-fold gamma-ray coincidences detected in the Eurogam spectrometer following the reaction Cd-114(Ca-48, 5n)Er-157 at a bombarding energy of 210 MeV. Particularly favoured states have been established at I-pi = 69+/2, 81+/2, 71+/2, 77-/2, 87-/2 and 89-/2. Specific single-particle configurations are assigned to these special states by comparison with cranked Nilsson-Strutinsky calculations. These states are related to structures observed in the neighbouring nuclei Er-158 and (HO)-H-157. These data provide the spectrum of single-particle states for the lowest lying valence orbitals above the Gd-146 closed core.
Original language | English |
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Pages (from-to) | 193-213 |
Journal | Journal of Physics G-Nuclear and Particle Physics |
Volume | 21 |
Issue number | 2 |
Publication status | Published - 1995 |