A crossed electron—ion beam setup for ionization experiments

Electron impact double ionization of krypton ions (q= 14-17)

“…In this experiment, the animated crossed beams method (Defrance et al 1981) has been employed. The apparatus was essentially described earlier (Duponchelle et al 1995). Krypton ions are extracted from an ECR source (Barué et al 1998).…”

“…As required by the animated beam method, the electron beam is swept mechanically across the ion beam in a seesaw motion. The ionization cross section is related to the measured quantities in the following way (Duponchelle et al 1995):…”

Electron-impact ionization of neon ions (q= 4 - 8)

“…In the experiments, the animated crossed-beams method (Defrance et al 1981) has been employed. The present apparatus is described in detail elsewhere (Duponchelle et al 1995). It has been specially designed to study electron-impact single and multiple ionization of multiply charged ions (X q+ ) up to q = 20 in an electron energy range from 20-6000 eV.…”

“…where L is the luminosity. In the present application of the animated beam method, the ionization cross section is related to the measured quantities in the following way (Duponchelle et al 1995):…”

“…The electron energy is corrected for contact potential (−0.5 eV) and the kinetic energy of ions is taken into account to obtain the absolute collision energy (Duponchelle et al 1995). The uncertainty on this energy is ±0.5 eV.…”