ELECTRON-IMPACT IONIZATION CROSS-SECTION MEASUREMENTS FOR U-10+, U-13+, AND U-16+

Absolute measurements are presented for electron-impact single ionization of U10+, U13+, and U16+, and for double ionization of U10+ and U13+ from below the thresholds to 1500 eV. Metastable components are observed in all three incident-ion beams. The single-ionization cross sections are enhanced due to indirect ionization processes by factors of 420 near their peaks, and the double-ionization cross sections are apparently also dominated by indirect ionization. Good agreement is found with distorted-wave calculations for total ionization of U16+, the only case where detailed calculations are available for comparison. Individual or closely spaced resonances are clearly resolved in the single-ionization channels for U13+ and U16+. © 1990 The American Physical Society.