DoubleK-shell ionization in the internal-conversion decay ofAgm109

Double ionization of the atomic $K$ shell accompanying the $K$-shell internal conversion of the 88.0-keV $E3\mathrm{}$ transition of ${}_{}{}^{109}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}$ has been studied by recording coincidences between $K$ x rays and $K\alpha$ x rays emitted when the double vacancies are filled. The probability per $K$-shell internal conversion that a double $K$-shell vacancy is formed, $T_{\mathrm{KK}}$, was found to be (1.53±0.24) × ${10}^{-4\mathrm{}}$, and is about a factor of 5 smaller than a previous measurement. The energy shift, $\Delta E$, of the $K\alpha$ "hypersatellite" x ray was measured to be (373 ± 75) eV.