ION-COLLISION EXPERIMENTS WITH SLOW, VERY HIGHLY CHARGED IONS EXTRACTED FROM AN ELECTRON-BEAM ION TRAP

Highly charged Ar (up to 18+), Xe (up to 48+), and U (up to 71+) ions produced through electron-impact ionization and excitation in an electron-beam ion trap have efficiently been extracted from the trap, and mass and charge analyzed. Charge-state distributions for Ar and Xe ions following electron-impact ionization and excitation have been measured. Relative yields for the production of Ar16+ and Xe44+ ions have been deduced as a function of electron-beam energies. Ar K and Xe L x-ray emission following Ar17+, Ar18+ and Xe44+, Xe45+ and Xe48+ ion impact on a Cu surface was measured. The observed line positions demonstrate electron capture into high-n states and a fast radiative decay in the neutralization process at the surface. © 1990 The American Physical Society.