Electron-impact ionization of Se3+

Absolute electron-impact single and multiple ionization cross-section measurements for Se3+ ions were performed using the dynamic-crossed-beams technique over the energy range from the ionization threshold to 1 keV. The experimental single ionization cross section for Se3+ shows evidence of significant contributions of 4s–nl (n ≥ 6) and 3d–nl (n ≥ 4) inner-shell excitation-autoionization. The cross sections for double and triple ionization are dominated by ionization-autoionization and ionization-double autoionization of a 3p or 3s electron, respectively. The measurements were compared with the direct ionization cross sections predicted by the Lotz semi-empirical formula for direct ionization. The maximum values of cross sections for single, double, and triple ionization are compared. (paper)