Abstract
The decays of the 206-day and 2.9-yr electron-capture activities of have been studied with a Ge(Li) spectrometer and with a coincidence system. From the analysis of -ray spectra, measured over a period of 1.5 years, the rays associated with each activity were identified. Twenty-four transitions, nine previously unreported, are assigned to the decay of 206-day , and fifteen, six previously unreported, to 2.9-yr . All observed transitions except one are placed in a consistent level scheme for with levels at 0, 475, 944, 1103, 1106, 1522, 1581, 1837, 2037, and 2261 keV populated by the 206-day activity; and 0, 475, 1103, 1106, 1522, 1799, 1873, and 2219 keV from the 2.9-yr activity. The levels at 944, 1581, and 1799 keV have not been previously reported. The values of the various electron-capture branches are consistent with a spin of 1 for the 206-day level of and with a spin ≥4 for the 2.9-yr state. A reasonable assignment for the new 944-keV level is 0+, which suggests that it is associated with the 2+ and 4+ two-phonon states reported at 1103 and 1106 keV, respectively.
- Received 21 August 1968
DOI:https://doi.org/10.1103/PhysRev.177.1792
©1969 American Physical Society