Abstract
The 90° yield for gamma rays from , , , and was determined for () reactions using 10.4- to 14.5-MeV protons from the Columbia University variable energy cyclotron. For the yields to both the first excited state and the ground state of the residual nucleus are presented. In the case of , only the ground-state yield was determined. Because the ground-state yields are very small, we report only the yield due to transitions to the first excited state for the reaction and the combined first excited and ground-state yields for the reaction. In the region investigated, the yield curves exhibit a considerable amount of fine structure in all cases except . Fine-structure peaks were observed for the following excitation energies: 21.9, 22.4, 22.7, 23.0, 23.3, 24.1, 24.7, and 25.4 MeV for ; at 18.8, 19.2, 19.5, 20.0, 21.0, and 21.7 MeV for ; at 25.5, 26.9, 28.0, and 28.45 MeV for ; and at 25.5, 27.45, 28.0, and 28.9 MeV for . A comparison with other experimental results shows that some of these peaks have not been previously observed.
- Received 12 December 1966
DOI:https://doi.org/10.1103/PhysRev.157.921
©1967 American Physical Society