Excitation and ionization of multicharged ions by electron collisions

Investigations of the processes of excitation and ionization of multicharged ions by electron collisions are reviewed. It is shown that the Coulomb–Born method with exchange, for calculating cross sections of these processes, is identified here with the perturbation theory in a small parameter–the reciprocal of the ion charge. Resonant scattering substantially alters excitation cross section in a small region of collision energies; however, its contribution to excitation constant is small. Relativistic effects are also considered.