ELECTRON-IMPACT SINGLE IONIZATION OF LOW-CHARGED MOLYBDENUM IONS

The electron-impact single ionization of low-charged Mo ions is studied both experimentally and theoretically. The absolute cross sections for Mo{sup {ital q}+} ions in charge states {ital q}=1{endash}8 are measured using a crossed-beam technique. Distorted-wave calculations are made including both direct ionization and excitation-autoionization contributions. For ions in charge states {ital q}=6{endash}8, the measured cross sections are in good agreement with calculations involving only the lowest-energy metastable configuration. For ions in charge states {ital q}=3{endash}8, the good agreement between experiment and theory confirms the dominant role played by excitation-autoionization contributions to the total ionization cross section. {copyright} {ital 1996 The American Physical Society.}