Electron-impact ionization of multiply charged manganese ions

Abstract

Distorted-wave calculations are carried out for the electron-impact ionization of atomic ions in the Mn isonuclear sequence. Detailed level to level calculations are performed for the dominant excitation-autoionization contributions. The validity of the configuration-average approach is studied and used to calculate direct ionization and higher n excitation-autoionization, when the level to level approach proves computationally too demanding. A combination of the two methods is used to analyze the recent crossed-beams experimental measurements of ${\mathrm{Mn}}^{5+},$ ${\mathrm{Mn}}^{6+},$ ${\mathrm{Mn}}^{7+},$ and ${\mathrm{Mn}}^{8+}$ by Rejoub and Phaneuf [Phys. Rev. A 61, 032706 (2000)]. The comparison between theory and experiment indicates that a large fraction of the initial population of each measured ion is in metastable states of excited configurations.