Dynamics of the ionization mechanism in ion-atom collisions at intermediate velocities

We present the results of a set of quantum and classical model calculations designed to discuss the dynamics of the ionization process in ion-atom collisions at intermediate velocities. It is shown that the ionized electrons, ejected with velocities coinciding with that of the saddle point resulting from the combination of the projectile and target potentials, have experienced a complex dynamical process. One of the outcomes of our simulations is that only a small fraction of these electrons are those which surf on the saddle all along the collision process. These findings shed light on the reason why saddle electrons are not observed at high projectile velocities.