Electron correlation in high energy ion-atom collisions

Abstract

Due to the strong electron-nucleus force in the target atom, many atomic collision processes are well-described within the independent particle model. Even in such cases Pauli-blocking correlations can be important for inclusive cross sections. This talk focuses on ion-atom collisions where dynamical correlations due to interaction between the electrons during the collision play an important role. Such correlations can be important for multielectron transitions in weak coupling cases (high collision energies), since to first order in the projectile interaction and without correlation the cross section is zero. One example to be discussed is the double ionization of helium, where one manifestation of the correlation is the large difference in double ionization produced by protons and antiprotons. For this system both differential and total cross sections will be discussed, as well as the related processes of double excitation and of excitation plus ionization. Another class of cross sections to be discussed are those involving charge transfer: double capture and transfer ionization.