Electron-Impact Ionization of Samarium Ions

Abstract

Electron-impact ionization cross sections σq,q+ n have been measured for the reaction e + Smq+ → Sm(q+n) + (n + 1)e for single, double and triple ionization and initial charge states q = 1, 2, 3. The measurements have been performed using the dynamic crossed-beams technique in an energy range from the respective ionization threshold up to 1 keV. Furthermore, we have measured the single-ionization cross section for Sm12+ using the dynamic crossed- beams method and an energy-scan method. The cross sections are compared with semi-empirical formulae. In most cases the measured cross sections are described insufficiently. In the single-ionization cross section for Sm12+ a remarkable number of narrow structures resulting from resonant excitation with subsequent double-autoionization (REDA) are observed.