Unified Theory of Ion-Impact and Shake-Off Contributions to Multiple Vacancy Production

In collisions of atoms with a photon, electron, or proton the projectile usually makes at most a single hole; additional vacancies may be weakly produced by "shake-off" resulting from a sudden change in the Hartree-Fock potential. With projectiles of nuclear charge greater than one the probability for impact ionization of both K shell electrons is increased. For K¿ hypersatellites (K2Lv) the change in the potential is much greater than for the satellites (KLv), and L-shell shake-off may be expected to be appreciable in light atoms. We have extended our independent-Fermi-particle treatment of ion-impact multiple vacancy production to include shake-off. Calculations for He and C ions on neon exhibit large shake-off contributions for K2LV and non-negligible ones for KLv.