Measurement of the lifetime and the electron-impact excitation cross section and polarization of the 2 3P term of singly ionized lithium

The lifetime of the $2 ^{3}P_{j}$ states in singly ionized lithium has been measured using an rf magnetic-resonance technique; the value is τ=45±5 nsec. Neutral lithium was ionized and excited by a unidirectional beam of electrons which produced an alignment in the excited state. The cross section for the electron-impact excitation 1s²2s²S→1s2p³P near threshold was measured to be ${10}^{-22\pm 1}$ cm². Implications for the feasibility of rf resonance spectroscopy on the fine and hyperfine structure of the $2 ^{3}P$ term will be discussed.