Theoretical calculations of γ-ray feeding patterns for Gd, Dy and Er nuclei
1985; Elsevier BV; Volume: 443; Issue: 1 Linguagem: Inglês
10.1016/0375-9474(85)90323-9
ISSN1873-1554
AutoresSven Åberg, T. Døssing, K. Neergård,
Tópico(s)Advanced Chemical Physics Studies
ResumoAbstract The side-feeding patterns and the spectra of unresolved γ-lines are calculated for Gd, Dy and Er nuclei with neutron numbers from 82 to 86. Energies and configurations for states from the yrast line and approximately 2 MeV higher in energy are calculated as many-quasiparticle configurations in a deformed oblate potential. The γ-cascade is simulated by a Monte Carlo calculation. With a common average entry angular momentum of 35 h to the non-collective oblate states considered, the observed variation of intensity of the strongest γ-line with spin is well reproduced. The stretched dipole part of the continuum spectra is also well reproduced, whereas the stretched quadrupole part cannot be accounted for. These findings are in accordance with a two-stage picture of the γ-decay. First comes a cascade of stretched quadrupole transitions, probably of collective nature. This cascade feeds into numerous weakly oblate states around spin ≈ 35 h , and the decay proceeds first by weak transitions, mainly dipoles, and later by strong γ-lines.
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