Total Cross Sections for Inelastic Scattering of Charged Particles by Atoms and Molecules. IV. Positive Lithium Ion

The Born cross sections for several important discrete excitations of Li⁺ from its ground state have been calculated with correlated wave functions. By extrapolation, cross sections for higher excitations have also been determined. Subtraction of the sum σₑₓ of these excitation cross sections from the total inelastic-scattering cross section σₜₒₜ obtained through a sum rule for the Bethe cross sections yields a reliable "counting" ionization cross section σᵢ. The cross sections thus obtained are ${{σ}}ₜₒₜ={({z}{{β}})}²(0.536{ln[{{{β}}²}{(1{-}{{β}}²)}]{-}{{β}}²}+5.216±{}0.002)×{}{10}^{{-}20}$ ${{σ}}ₑₓ={({z}{{β}})}²(0.265{ln[{{{β}}²}{(1{-}{{β}}²)}]{-}{{β}}²}+2.295±{}0.002)×{}{10}^{{-}20}$ and ${{σ}}ᵢ={({z}{{β}})}²(0.271{ln[{{{β}}²}{(1{-}{{β}}²)}]{-}{{β}}²}+2.921±{}0.004)×{}{10}^{{-}20}$ where $ze$ is the charge of the incident particle and ${β}$ is its velocity divided by that of light. The ionization cross section is in excellent agreement with experimental data in the asymptotic region (incident electron energy {} 5 keV).