Electron-impact ionization for U/sup 91+/ in the QED theory

Electron-impact ionization of highly charged ions is studied in the QED theory. Our calculation will include the transverse-photon interaction as well as the vacuum-polarization potential between charges. We apply the two-potential distorted wave approximation to compute the ionization cross sections. Both direct and exchange effects are considered. The calculated results are compared with those from other theories and with experiment.