Abstract
The decay of 3.6-h to levels in has been studied by -ray and conversion-electron spectroscopy. A level scheme is proposed which accounts for all but 35 of the 256 rays assigned to this decay. Most of the low-lying levels in show a remarkably close correspondence with the predictions of the simple vibrator model. Possible candidates are observed for three-phonon quadrupole states and for the states coupling quadrupole and octupole phonons. The low-lying positive-parity levels can be adequately described by the phenomenological collective model of Gneuss and Greiner. The microscopic boson-expansion model of Kishimoto and Tamura, however, appears to predict to be more transitional than the data imply. Systematics of the 86-neutron isotones show increased stability at 64 protons. This can be correlated with the filling of the and spherical proton orbitals.
RADIOACTIVITY [from ], measured , , , , , , and coin; deduced , . deduced levels, ICC, , . Enriched target, Ge(Li), and Si(Li) detectors.
- Received 26 October 1976
DOI:https://doi.org/10.1103/PhysRevC.16.1129
©1977 American Physical Society