The lifetime and binding energy of the lowest-lying metastable quartet state, $\mathrm{}\left(1s2s2p\right)\mathrm{}{}_{}{}^4{}_{}{}^{}p°_{\frac{5}{2}}^{}{}_{}{}^{}$ in ${\mathrm{S}}^{13+}$ have been measured by studying the forbidden (spin-spin-induced) autoionizing decay in flight of the state after foil excitation. The state is found to be bound by -4988 ± 26 eV and has a lifetime of 1.1 ± 0.1 nsec. A summary of our previous measurements of these same quantities for other members of the lithiumlike sequence is also given, along with an estimate of the branching ratio for the autoionization process.

• Received 29 October 1973

DOI:https://doi.org/10.1103/PhysRevA.9.1112