Theoretical study of cross sections of excitation and ionization for electron-ion impact in average-atomic model

Abstract

By using a distorted-wave Born exchange approximation method in averaged-atomic model, we calculated the direct excitation and direct ionization cross sections of several ions in plasmas. The ionization cross sections of ions at different temperatures or different plasma densities are systematically studied. It is found that due to the shift of the energy levels produced by the effects of the temperature and the density of plasma, the ionization cross sections of ions in plasmas are rather different from those of free atoms.