Abstract
Levels of , , , , and below about 5 MeV were investigated by observation of the energy and angular distributions of protons emitted in the () reactions at 15-MeV bombarding energy. Values of the transferred-neutron angular momenta and of the spectroscopic factors for levels were derived from the measurements by distorted-wave Born approximation calculations. The results for the degree of filling of shell-model states and locations of the "centers of gravity" of the shell-model levels were compared with the pairing theory of Kisslinger and Sorensen. It was found that the , , and subshells are less full and the more full than expected. General agreement with pairing theory was obtained with the following parameters: MeV, MeV, MeV, , and MeV from the odd-even mass difference. In , an isomer of spin at 0.22 MeV was identified. Measurements on () reactions indicate that the subshell from the next (50-82) major shell is filling (∼0.6 particle) in the Se nuclei, even though the lower (28-50) major shell is not completely full.
- Received 18 February 1965
DOI:https://doi.org/10.1103/PhysRev.139.B340
©1965 American Physical Society