Influence of orbital sets on the Ar+(2s−1) multiple Auger decay

Abstract

The single, double, triple, and quadruple Auger decays of ${\mathrm{Ar}}^{+}(2{s}^{\ensuremath{-}1})$ are studied, based on many-body perturbation theory. The level-to-level investigation indicates that the double Auger primarily comes from the cascade process involving the Coster-Kronig decay. Moreover, the complex triple Auger and quadruple Auger decay are expressed by the multistep approach, i.e., the combination of cascade and direct processes. On the other hand, by employing the separate orbital sets for optimizing the single-electron wave functions, our ion yield ratios (${\mathrm{Ar}}^{2+}:{\mathrm{Ar}}^{3+}:{\mathrm{Ar}}^{4+}:{\mathrm{Ar}}^{5+}=3.5:88.7:7.5:0.26$) agree quite well with the recent experimental data (3:89:8:0.3) [Lablanquie et al., Phys. Chem. Chem. Phys. 13, 18355 (2011)]. Moreover, the single, double, and triple Auger spectra, as well as lifetime, are all in accord with the measurements of Lablanquie et al.