Determination of the absolute K through O conversion coefficients of the 80-keV M4 transition in /sup 193/Ir/sup m/

We produced carrier-free, nearly isotopically pure /sup 193/Ir/sup m/ from thermal-neutron irradiation of /sup 192/Os. From studies of the conversion-electron spectrum, the photon spectrum, and the absolute counting rates, we determined the absolute K, L1, L2, L3, M1, M3, M5, N, and O+P conversion coefficients for the first time. With possibly one exception, these values agree closely with theoretical calculations. The value for the energy of the unconverted gamma ray was found to be 80.22 +- 0.02 keV. The half-life for /sup 193/Ir/sup m/ determined by absolute electron counting in a proportional counter of 100% counting efficiency (4πβ) was found to be 10.53 +- 0.04 d. We have determined the L1 subshell fluorescence yield, ω1, to be 0.120 +- 0.003 for iridium. Based upon our measurements of initial and final L subshell vacancies together with a best-fit literature value for ω2, we have found a plausible value for the Coster-Kronig coefficient f/sub 12/ to be 0.091 +- 0.011