We present relative cross section measurements of the inner-shell ionization of highly charged chromium ions by high-energy (7-30 keV) electrons. The measurements use a technique based on high-resolution x-ray spectroscopy, which correlates ionization events with K∝ decay x rays. Moreover, the measurements show that inner-shell ionization only affects the strength of the heliumlike 1s2s 3S1 -> 1s2 1S0 forbidden line. The cross sections inferred for Li-like Cr21+ agree well with distorted wave calculations.
Relativistic distorted wave approach to electron impact excitation of argon gas using a complex potential