Distorted-wave electron-impact-ionization cross sections for highly ionized neonlike atoms

Electron-impact-ionization cross sections have been computed for several neonlike ions in a distorted-wave Born exchange approximation. For lower ionization stages the total cross section was found to be sensitive to the details of the distorted potential in which the partial waves were calculated. Ionization from the $2s^2$ core subshell increased in importance for higher charge states. Isoelectronic curves are presented which allow the interpolation of nonrelativistic electron-impact-ionization cross sections for any ion in the neon sequence in the incident electron energy range of one to three times threshold. A comparison to available experimental and semiempirical formulas is made.