Electron-impact ionization of moderately charged xenon ions

Absolute and energy scanned cross sections for the electron-impact single ionization of Xeq+ (q = 10-17) atomic ions are measured by employing a crossed-beams technique in the collision energy range from threshold to 1000 eV. Direct ionization and indirect excitation-autoionization cross sections are calculated using a configuration-average distorted-wave method for the ground and first same parity excited configuration of the Xeq+ (q = 10-17) atomic ions. Both the crossed-beams experiment and distorted-wave theory show a steady decrease in the ionization cross section as the charge of the ion increases. The disagreements between experiment and theory are partly attributed to the many metastable levels of ground and excited configurations found in the ion beam.