Quantal and classical calculations of He2++Li interactions at intermediate energies. II. Direct excitation and ionisation

For pt.I see ibid., vol.20, no.13, p.3125 (1987). The authors report quantal and classical calculations of single-electron ionisation and direct excitation in collisions between He 2+ ions and neutral Li. Calculations by both methods have included a K-shell correction to the ionisation and in both cases the interaction between the active electron and the lithium core was represented by an effective potential described earlier in I. Quantal calculations have been performed using close-coupled atomic-orbital expansions with up to 65 pseudostates in the basis, within the impact parameter formalism described in I. The range of impact energies treated in this work was from 22 to 10000 keV lab. The authors propose a semi-empirical method for estimating a correction due to the finite size of the basis, based on a combination of the close-coupled and first Born ionisation results. CTMC calculations have been carried out in the impact energy range from 40 to 2000 keV lab.