Time-dependent screening effects in ion-atom collisions with many active electrons - art. no. 042704

Ionization and electron transfer in collisions of bare ions from neutral ta rget atoms with many active electrons are investigated within the independe nt particle model. We propose a simple model for the inclusion of time-depe ndent screening effects and discuss the question of how to analyze the solu tions of the single particle equations in order to avoid fluctuating transi tion probabilities, which normally occur when the effective mean-field pote ntial depends on the propagated orbitals. The basis generator method is use d to solve the single-particle equations for the He2+ +Ne collision system in the energy range of 5 to1000 keV/amu. It is shown that time-dependent sc reening effects reduce the cross sections for ionization and capture at low and intermediate impact energies significantly. Good overall agreement wit h experimental data is found except for the higher final charge states of t he target ion.