3d photoionization of ions from the xenon isonuclear sequence
POSTER
Abstract
The photon-ion merged-beams technique has been employed at the new \underline{P}hoton-\underline{I}on spectrometer at \underline{PE}TRA\,III (PIPE) for measuring multiple photoionization of Xe$^{q+}$ ($q$=1--5) ions. Total ionization cross sections have been obtained on an absolute scale for the dominant ionization reactions of the type $h\nu + \mathrm{Xe}^{q+} \to \mathrm{Xe}^{r+} + (q-r)e^-$ with product charge states $q+2\leq r \leq q+5$. Prominent ionization features have been observed in the photon-energy range 650--800 eV, which are associated with excitation or ionization of an inner-shell $3d$ electron. The well-known collapse of the $4f$ wave function causes dramatic changes in the spectra when going from low to high $q$.