Target Recoil Effects for Inner-Shell Ionization in Ion-Atom Collisions

Calculations are reported that show the effect of target recoil on K-shell ionization in ion-atom collisions. Target recoil effects are significant in low-energy and small impact parameter collisions, for which Coulomb deflection and corrections to the first Born approximation (increased binding) are also quite important. The non-inertial recoil term that arises when the hamiltonian is written in target-centered coordinates has been discussed in the literature already by several authors. Our contribution is to include this finite target mass effect in our large basis coupled-state calculations, which then incorporate effects of recoil, Coulomb deflection, and target orbital perturbations and couplings in a consistent and accurate manner. Results for ionization probability as a function of impact parameter are presented and compared to experiment for several collision energies, projectiles (of different mass and charge), and targets.