Auger spectra following inner-shell ionization of Argon by a Free-Electron Laser

We explore the possibility of retrieving Auger spectra with FEL radiation. Using a laser pulse of 260 eV photon energy, we study the interplay of photo-ionization and Auger processes following the initial formation of a 2p inner-shell hole in Ar. Accounting for the fine structure of the ion states we demonstrate how to retrieve the Auger spectrum of $\mathrm{Ar^{+}\rightarrow Ar^{2+}}$. Moreover, considering two electrons in coincidence we also demonstrate how to retrieve the Auger spectrum of $\mathrm{Ar^{2+}\rightarrow Ar^{3+}}$.