Collisions of Atoms (Ions) with Highly Charged Ions: Excitation and Ionization

Abstract

Excitation and ionization processes in collisions of atoms with multiply charged ions may occur as a result of either one-electron or many-electron transitions in the system. Generally speaking, the single-electron excitation and ionization processes in the adiabatic energy region (υ ≪ 1) are characterized by cross sections which are much smaller than the cross section for electron capture. In the intermediate-energy region (υ ~ 1), single-electron excitation and ionization become as effective as the charge-transfer process, and at high collision energies (υ ≫ 1) they become dominant inelastic processes in the ion-atom collision. For the multi-electron-transition processes such general relationships between the cross sections of the excitation, ionization, and charge-transfer processes cannot be ruled out. Moreover, combined processes, such as simultaneous capture and ionization (or excitation) become dominant and, with increasing ionic charge, their role in the collision dynamics becomes increasingly pronounced.