Determination of Energies and Lifetimes of the Metastable Auto-Ionizing(1s2s2p)P4States ofLi6andLi7by a Zeeman-Quenching Technique

A Zeeman-quenching atomic-beam method has been utilized for the determination of the fine- and hyperfine-structure energies and auto-ionization lifetimes of the metastable $\mathrm{}\left(1s2s2p\right)\mathrm{}{}_{}{}^4{}_{}{}^{}P_J^{}{}_{}{}^{}$ states of ${\mathrm{Li}}^6$ and ${\mathrm{Li}}^7$. Both the fine-structure intervals and the lifetimes of the $J=\frac{3}{2}$ and $J=\frac{1}{2}$ states are found to be in disagreement with existing theoretical calculations. The quenching of metastable lithium atoms in a nonuniform magnetic field can be satisfactorily described with the aid of the "adiabatic criterion." The present results also permit a quantitative evaluation of a proposal for producing polarized lithium nuclei.