Non-sissociative single-electron capture studied for O2 Ions on Ar, N2 and He at 100 eV

Abstract EN

Energy-gain spectra for single-electron capture by O22+ ions colliding with Ar, He and N2 have been measured at an impact energy of 100 eV and 0º scattering angle by means of translational energy-gain spectroscopy.

In O22+ - Ar and N2 collisions, only one peak is observed at the energy-gain around 3.5 eV, which is correlated with nondissociative single-electron capture from ground state (X 1Σg+) of O22+ ions into the A 2Πu state of O2+.

However, for the O22+ - He collision system, the dominant channels are due to capture into the ground state X 2Πg of O2+ from W 3Δu, B 3Πg and B/ 3Σu- metastable states of the O22+, respectively.

A reasonable description of the dominant final states is obtained qualitatively in terms of the reaction windows, which are calculated using the Landau- Zener (LZ) model and the extended version of the classical over-the-barrier (ECOB) model.

Differential cross sections for single-electron capture by 100 eV O22+ ions from Ar have also been measured.

The results are quantitatively explained by semi-classical model based on Coulomb potential energy curves.