The $Q$ value for the electron-capture decay of ${\mathrm{Pt}}^{193}$ has been determined to be 60.8±3.0 keV, from a measurement of the endpoints of the $L$- and $M$-shell capture internal bremsstrahlung. The partial half-life for $L$ capture was found to be 620±250 yr by the determination of the specific activity of a sample.

• Received 11 March 1969

DOI:https://doi.org/10.1103/PhysRev.185.1565