Differential cross-section measurements of multiply charged xenon ions produced in 10–28-keV e⁻-Xe collisions

Partial single-differential ionization cross sections (PSDICSs) of a multiply ionized xenon atom (Xeⁿ⁺, n=1–7) are measured for impact of 10–28 keV electrons with xenon by performing coincidences between the produced recoil ions and the electrons of indiscriminated energies detected at 90° with respect to the incident electron beam direction. Values of relative PSDICSs for doubly charged ions are found to be about 25% larger than those for singly charged ions in the considered impact energy range. The examination of charge-state fractions and relative cross-section fractions of multiply charged ions as a function of incident electron energy suggests that the multiply charged ions are produced via creation of an inner-shell vacancy followed by Auger and shakeoff processes. The mean charge state of the ions produced in the collisions is found to be independent of the impact energy and reaches a constant value close to 2.6. The Fano-Bethe plots of the PSDICSs suggest that higher charge states of the ions are weakly produced via optical transitions; moreover, the latter process becomes a dominant channel for producing the doubly charged ions that are correlated with the electrons detected at 90°.