Simultaneous Electron Capture and Excitation in S + Ar Collisions

Electron capture accompanied by simultaneous $K$-shell excitation has been observed for 70-MeV ${\mathrm{S}}^{13+}$ + Ar collisions. This process is analogous to dielectronic recombination for the case of free electrons incident on highly charged ions. In addition, radiation following capture into high-$n$ states without accompanying excitation is measured for charge states $q=14+ \mathrm{to} 16+$. The results are used to determine the fraction of capture events which result in $K$-shell radiation, and the fraction of $K$ x rays resulting from capture events.