Electron-impact ionization of tungsten ions in the configuration-average distorted-wave approximation

Abstract

Single-ionization cross sections for ${\mathrm{W}}^{4+},$ ${\mathrm{W}}^{5+},$ and ${\mathrm{W}}^{6+}$ are calculated in the configuration-average distorted-wave approximation. Contributions from excitation autoionization are found to be strong for each ion. When comparing theory with the recent crossed-beams measurements of Stenke et al. [J. Phys. B 28, 2711 (1995)], ionization from the ground configuration dominates for ${\mathrm{W}}^{4+}$ and ${\mathrm{W}}^{5+},$ while ionization from metastables of excited configurations dominates for ${\mathrm{W}}^{6+}.$