Relativistic cross sections of the electron-impact ionization of heliumlike ions - art. no. 032710

Single-differential and total cross sections of electron-impact ionization are calculated in a relativistic formulation for ions in the helium isoelec tronic sequence: He, Li+, B3+, C4+, N5+, Na9+, Fe24+, and Ag45+. Transition amplitudes are evaluated in the two-potential distorted-wave approximation . Relativistic effects are investigated by taking the nonrelativistic limit . Both the rearrange and capture amplitudes are found to be important near the ionization threshold. Results are compared with other theoretical calcu lations and experimental data. The systematics of ionization cross sections along the isoelectronic sequence is also studied.