Electron capture processes in slow collisions of Ne6+ ions with CO2 and H2O
Department of Physics, Western Michigan University - Kalamazoo, MI 49008-5252, USA
Accepted: 3 January 2011
Energy-gain spectra and absolute total cross-sections for single-, double-, and triple-electron capture processes in collisions of Ne6+ ions with CO2 and H2O at laboratory impact energies between 450 and 2400 eV, have been studied experimentally by means of a translational energy-gain spectroscopy technique. The energy-gain spectra for single-electron capture show that the dominant reaction channels are due to capture into the n = 4 state of Ne5+, in agreement with classical over-the-barrier model calculations. In both cases, contributions due to transfer excitation into the 2s2p (1,3P) 3 l states are also detected. The energy-gain spectra are interpreted qualitatively in terms of the reaction windows, which are calculated using the single-crossing Landau-Zener (LZ) model and the extended version of the classical over-the-barrier (ECOB) model. The energy dependence of cross-sections for electron capture are also measured and found to be slowly increased with increasing collision energy. The data for single-electron capture are also compared with theoretical results based on the multi-channel Landau-Zener (MCLZ) model.
PACS: 34.70.+e – Charge transfer / 82.30.Fi – Ion-molecule, ion-ion, and charge-transfer reactions / 34.50.Fa – Electronic excitation and ionization of atoms (including beam-foil excitation and ionization)
© EPLA, 2011