Plasma effects on electron impact ionization

Self-consistent calculations of plasma effects on atomic structure, based on the ion-sphere model, are presented. The electron impact ionization cross section is calculated, using a distorted-wave approximation, for partially ionized gold plasmas at different temperatures and densities. The results show large plasma effects on collisional ionization at high density and low temperature. The plasma medium leads to enhancement of the ionization cross section by a factor of up to two.