Electron-impact excitation and ionization cross sections for the Si, Cl, and Ar isonuclear sequences

Abstract

Electron-impact excitation and ionization cross sections are presented for all atomic ions in the Si, Cl, and Ar isonuclear sequences. These data contribute to the continuing effort to provide accurate collisional data for magnetic fusion and astrophysical modeling. For excitation processes, level-resolved cross section calculations are presented which were made using first-order many-body perturbation theory. For ionization processes, we present calculations made with the configuration-average approximation using a distorted-wave method. A selection of excitation and ionization cross sections are compared with experiment, where available. For ionization of ${\text{Si}}^{2+}$ and ${\text{Si}}^{3+}$, we also compare with calculations made using time-dependent close-coupling theory, to assess the accuracy of the distorted-wave calculations. Our cross sections will be tabulated in several atomic collision databases for use in future kinetics modeling efforts.