Charge-changing collisions of argon ions on argon gas. One-electron capture

Abstract

Single-electron-capture cross sections have been measured for argon ions with initial charges $2\le q\le 12$ incident on an argon-gas target. The cross sections show little dependence on the incident ion energy in the range $1q-10q$ keV. A remarkable oscillating feature is seen for cross sections ${\sigma }_{q,q-1\mathrm{}}$ when $q\ge 7$. Particularly, ${\sigma }_{8,7}$ is smaller than ${\sigma }_{7,6}$ and ${\sigma }_{9,8}$, the ${\mathrm{Ar}}^{8+}$ electronic structure being Ne-like. Variation of the cross section is shown as function of the initial charge at constant energy.