Decay ofRh102andRh102m

Abstract

The decays of the 206-day and 2.9-yr electron-capture activities of ${}_{}{}^{102}{}_{}{}^{}\mathrm{Rh}$ have been studied with a Ge(Li) spectrometer and with a $\gamma -\gamma$ coincidence system. From the analysis of $\gamma$-ray spectra, measured over a period of $\approx$ 1.5 years, the $\gamma$ rays associated with each activity were identified. Twenty-four transitions, nine previously unreported, are assigned to the decay of 206-day ${}_{}{}^{102}{}_{}{}^{}\mathrm{Rh}$, and fifteen, six previously unreported, to 2.9-yr ${}_{}{}^{102}{}_{}{}^{}\mathrm{Rh}$. All observed transitions except one are placed in a consistent level scheme for ${}_{}{}^{102}{}_{}{}^{}\mathrm{Ru}$ 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 $log\mathrm{ft}$ values of the various electron-capture branches are consistent with a spin of 1 for the 206-day level of ${}_{}{}^{102}{}_{}{}^{}\mathrm{Rh}$ 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.