Abstract
A study has been made of states in between 7.2- and 11.5-Mev excitation which belong to the sequence , , , ,... (even angular momentum and odd parity, and vice versa). These states cannot break up into + but must decay by emission. The rays from the and reactions were studied at bombarding energies up to 6.0 and 5.08 Mev, respectively, using a three-crystal pair spectrometer and other scintillation counters. The design, resolution, and efficiency of the three-crystal pair spectrometer are given. The ground state transition from the , 8.87-Mev state was observed to have 0.07±0.02 the intensity of the 2.73-Mev cascade transition to the , 6.14-Mev state. A state was found at 10.98±0.04 Mev which decays predominantly to the , 7.12-Mev state. No rays resulting from the decay of this state to other states of were observed. The angular correlation of the 3.86- and 7.12-Mev rays shows a positive anisotropy of approximately 1. These results suggest a spin and parity assignment for the 10.98-Mev state. The predictions of the alpha-particle and shell models of are compared with these results.
- Received 18 July 1957
DOI:https://doi.org/10.1103/PhysRev.108.802
©1957 American Physical Society