Electron-impact ionization ofW27+

Abstract

Electron-impact ionization cross sections for W 27+ are calculated using a semi-relativistic configuration-average distorted-wave (CADW) method. Calculations for direct ionization, excitation-autoionization, and branching ratios are compared with recent calculations by Jonauskas et al. (PRA 91, 012715 (2015)) who used fully-relativistic subconfiguration-average distortedwave (SCADW) and level to level distorted-wave (LLDW) methods. Reasonable agreement is found between the new CADW and the recent LLDW calculations for direct ionization of the 4l(l = 0 − 1, 3) subshells, but not the 4d subshell, and between the new CADW and recent SCADW/LLDW calculations for excitation-autoionization of the 4l(l = 0 − 2) subshells. Reasonable agreement is also found between the new CADW and the recent SCADW calculations including branching ratios, but both differ from the recent LLDW calculations. Additional CADW calculations are made for excitation-autoionization including branching ratios involving the important 3l(l = 1 − 2) subshells, not examined by Jonauskas et al. (PRA 91, 012715 (2015)).