Electron impact ionization of multicharged ions

Electron impact multicharged ion ionization cross section properties in nonrelativistic energy range are considered. Formulae in Coulomb-Born approximation with exchange and approximation parameters for cross sections and rates of single-electron ionization of multicharged ions are presented. Multielectron ionization processes are briefly concerned. Role of inner shell electrons (direct ionization + autoionization) which contribution grows by increase of ionized electron numbers and target ion atomic number is investigated. Widely used semi-empirical Lotz formulae for ion ionization cross sections and rates represent a correct dependence of values on incident electron energy and ion ionization potential