Electron-impact ionization of samarium ions

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