Decay of the Ar 2p5ndcore resonances: An autoionization spectrum dominated by shake processes

The autoionization of the Ar 2${\mathit{p}}^5$nd resonances has been studied both experimentally and theoretically. The effect of the partial collapse of the 3d wave function between the initial and the final state has been investigated with regard to shake probabilities as well as to the structure of the final ionic configuration. The decay probabilities depend strongly on the principal quantum number both of the core-excited ${\mathrm{Ar}}^{\mathrm{*}}$ 2${\mathit{p}}^5$nd state and of the ${\mathrm{Ar}}^{+}$ 3${\mathit{p}}^4$n’d final state. One of the most striking features is that the 2${\mathit{p}}^5$nd→3${\mathit{p}}^4$ndεl decay is almost completely forbidden for n=4.