Electron-impact single and double ionization of the Mn2+, Mn3+ and Mn4+ atomic ions

Abstract

Electron-impact single and double ionization cross sections for Mn2+, Mn3+ and Mn4+ are calculated using a semi-relativistic configuration-average distorted-wave method. The ionization cross sections include contributions from single direct ionization, double direct ionization and excitation–autoionization. Certain excitations may contribute to both single and double ionization as determined by branching ratio calculations. For Mn2+ the ratio of the double to single ionization cross section peak heights is found to be 0.15, while dropping to 0.03 for Mn3+ and 0.01 for Mn3+.