Energies and relative $\gamma$ ray and internal-conversion intensities for several transitions in ${\mathrm{Ir}}^{193}$ produced by the $\beta$ decay of ${\mathrm{Os}}^{193}$ have been measured. The $\gamma$-ray intensities were measured using a Ge(Li) spectrometer, and the internal-conversion intensities were measured using a 50-cm $\pi \sqrt{2}$ double-focusing iron spectrometer. The following precise energy-level values were determined: 73.03±0.08, 138.92±0.05, 142.02±0.20, 179.97±0.09, 361.84±0.14, 441.0±0.3, 460.62±0.09, 557.45±0.20, 559.48±0.25, 659.8±0.45, and 712.26±0.13. The $L$-subshell ratios for the 73-, 106-, and 139-keV transitions provided the information necessary to normalize the relative $\gamma$-ray and internal-conversion intensities yielding internal-conversion coefficients. The following level spins and parities were determined: 139-keV level, ${\frac{3}{2}}^{+}$ or ${\frac{5}{2}}^{+}$; 142-keV level, $\frac{5}{2}$ or $\frac{7}{2}$; 357-keV level, $\frac{7}{2}$; 362-keV level, ${\mathrm{½}}^{+}$, ${\frac{3}{2}}^{+}$, or ${\frac{5}{2}}^{+}$; and 460-keV level, ${\frac{3}{2}}^{+}$. The resulting decay scheme, multipolarities, and level spins and parities are discussed in terms of several nuclear models. The half-life of ${\mathrm{Os}}^{193}$ was determined to be 30.0±0.3 h.

• Received 19 December 1968

DOI:https://doi.org/10.1103/PhysRev.182.1286