LAUSR

Electron-impact single ionization is studied in the Si+ ion by considering transitions among energy levels. The study includes excitation-autoionization (EA) and collisional ionization processes. The excitations are investigated up to shells with the principal quantum numbers n ≤ 10. It is shown that correlation effects included in the EA calculations play a crucial role in explaining measurements. The correlation effects diminish the EA cross sections by ∼30% compared to single-configuration calculations. However, the collisional ionization is not significantly affected by an extension of the basis of interacting configurations. Good agreement between the presented level-to-level distorted wave data and experimental measurements is found for the single ionization of the Si+ ion.