Abstract
The decay of , , and has been studied with permanent magnet spectrographs, an intermediate-image beta spectrometer, and scintillation counters. Results on the electron-capture decay of and confirm the findings of previous investigators. The results of gamma-gamma directional correlation measurements are consistent with the spin assignments for the levels made by Ofer. ( days) is found to decay both by beta emission to a level of 749 kev in and by electron capture to levels of 453 and 1198 kev in . The percentage branchings are 35%, 35%, and 30%, respectively. Gamma-ray transitions of 453 and 745 kev in cascade in and 749 kev in are observed. The end-point energy for the beta-decay branch is measured to be 779 kev. Directional correlation and internal conversion coefficient measurements are most consistent with a 3+ assignment for the 1198-kev level in , with a 2+ assignment being possible, but less likely, since the cross-over transition is absent or extremely weak.
- Received 18 July 1960
DOI:https://doi.org/10.1103/PhysRev.120.1781
©1960 American Physical Society