Electron-impact ionization of Xe 24 +

Abstract

Configuration-average distorted-wave calculations are carried out for the electron-impact single ionization of Xe24 +. Contributions are included from direct ionization of the 3s, 3p, 3d and 4s subshells and from indirect ionization via 3s → nl, 3p → nl and 3d → nl excitations followed by autoionization. Branching ratios are found for single versus double ionization of the 3s and 3p subshells and for autoionization versus radiative decay of all 3l → nl excitations. Additional distorted-wave and R-matrix calculations find resonant-capture double-autoionization contributions to be quite small. The total ionization cross section for Xe24 + is found to be dominated by indirect excitation–autoionization contributions, especially near the single-ionization threshold. An approximate 15% reduction in the total ionization cross section is found due to the radiative decays included in the branching ratios.