On the perturbed-stationary-state theory of inner-shell ionization by heavy charged particles

The question of the adiabaticity in the perturbed-stationary-state (PSS) description of the ion-induced inner-shell ionization of atoms is investigated. A simple method is proposed to include the effect of the nonadiabaticity of the perturbed atomic states which increases with increasing collision velocity. Calculations show that the effect is not negligible, and its inclusion improves the agreement between theory and experiment. (orig.)