Time-dependent mean-field description for multiple charge-transfer processes in Ar⁸⁺-Ar collisions

We present a quantum-mechanical study of multiple-electron transfer processes in collisions between a highly charged ion and an atom, taking Ar⁸⁺-Ar collisions as an example. We employ time-dependent mean-field theories for this purpose, with different levels of approximation for the exchange effect. The time-dependent single-electron equation is solved directly by a discretization of the three-dimensional Cartesian coordinate into a uniform mesh. Calculations for various physical situations specified by the incident energy and the impact parameter are presented to elucidate the reaction mechanisms. They provide us with intuitive pictures of the electronic dynamics as well as a microscopic understanding of the reaction mechanisms. We also compare results with different treatments of the exchange effect to learn the sensitivity of our results on the possible uncertainty of the theories.