Hyperfine quenching and measurement of the 23P0–23P1fine-structure splitting in heliumlike silver (Ag45+)

The hyperfine-quenched transition 2 ${}_{}{}^3{}_{}{}^{}$ ${\mathit{P}}_{0–}$1 ${}_{}{}^1{}_{}{}^{}$ ${\mathit{S}}_0$ has been observed in heliumlike silver (${\mathrm{Ag}}^{45+}$) in the two isotopes ${}_{}{}^{107}{}_{}{}^{}\mathrm{Ag}$ and ${}_{}{}^{109}{}_{}{}^{}\mathrm{Ag}$. The lifetime for the transition has been measured for each isotope and found to be ${\mathrm{\tau }}_0$(107)=3.98(37)×${10}^{\mathrm{-}12}$ sec and ${\mathrm{\tau }}_0$(109)=2.84(32)×${10}^{\mathrm{-}12}$ sec. From the measured lifetimes a value is inferred for the absolute value of the 2 ${}_{}{}^3{}_{}{}^{}$ ${\mathit{P}}_{0–}$2 ${}_{}{}^3{}_{}{}^{}$ ${\mathit{P}}_1$ fine-structure splitting ‖Δ${\mathit{E}}_{0\mathrm{-}1}$‖ in ${\mathrm{Ag}}^{45+}$ with the result ‖Δ${\mathit{E}}_{0\mathrm{-}1}$‖=0.79(04) eV, where the uncertainty is the experimental uncertainty taken at the 1σ confidence level. This result is compared with calculations based on the multiconfigurational Dirac-Fock method, the unified method, and recent results from the relativistic configuration-interaction method.