Nuclear Levels ofRu101Populated in the Decay ofRh101Isomers

Abstract

The decay properties of 4.3-day ${}_{}{}^{101}{}_{}{}^{}\mathrm{Rh}_{}^m{}_{}{}^{}$ and 3.0-yr ${}_{}{}^{101}{}_{}{}^{}\mathrm{Rh}_{}^g{}_{}{}^{}$ have been investigated with the aid of a $p-i-n$, lithium-drifted germanium gamma-ray detector and with a NaI (Tl) gamma-gamma coincidence spectrometer. Energies (and transition intensities) of the gamma rays from the decay of ${}_{}{}^{101}{}_{}{}^{}\mathrm{Rh}_{}^m{}_{}{}^{}$ are 127.0±0.3 (1.2), 180.1±0.4 (0.9), 184.4±0.5 (0.3), 233.4±0.5 (0.4), 238.1±0.4 (0.5), 306.8±0.3 (100), 311±1 (0.1), 331.9±0.4 (0.06), 418±1 (0.01), and 545.2±0.5 (5.6) keV, and coincidence data require these transitions to be fitted into a level scheme in ${}_{}{}^{101}{}_{}{}^{}\mathrm{Ru}$ with energies at 127.0±0.3, 306.8±0.3, 311.0±0.5, 545.2±0.5, and 639±1 keV. Gamma-ray energies (and transition intensities) observed in the decay of ${}_{}{}^{101}{}_{}{}^{}\mathrm{Rh}_{}^g{}_{}{}^{}$ are 127.0±0.3 (105), 198.4±0.4 (100), 295.4±0.4 (0.9), 325.4±0.3 (21), and 422.4±0.6 (0.6) keV, which are consistent with excited states of ${}_{}{}^{101}{}_{}{}^{}\mathrm{Ru}$ at 127.0±0.3, 325.4±0.3, and 422.4±0.6 keV. Possible spin assignments for the excited levels in ${}_{}{}^{101}{}_{}{}^{}\mathrm{Ru}$ are discussed. The half-life of ${}_{}{}^{101}{}_{}{}^{}\mathrm{Rh}_{}^m{}_{}{}^{}$ was remeasured as 4.34±0.01 days.