State-selected studies of the electron capture by Ne3+ and Ne4+ ions from N-2 and O-2 molecules - art. no. 022701

State-selective differential cross sections for single-electron capture pro cesses in collisions of Neq+ (q = 3 and 4) ions with N-2 and O-2 have been studied experimentally at laboratory impact energies between 75 and 600 eV and scattering angles between 0 degrees and 8 degrees by means of a transla tional energy-gain spectroscopy technique. For the N-2 target, zero-angle t ranslational energy spectra show that the capture occurs mainly into 3s and 3d states of the projectile product Ne(q-1)+, respectively, for the ion ch arge states q = 3 and 4. For the O-2 target, the dominant reaction channels are due to capture into 3p and 3d', respectively, for charge states q = 3 and 4. In collisions of Ne3+ with N-2 and O-2, contributions from processes commencing with a long-lived metastable state Ne3+(2p(3) D-2) are detected . Other channels due to capture accompanied by target excitation are found to open at large scattering angles. The angle and energy dependence of cros s sections for single-electron capture by Neq+ (q = 3 and 4) ions from N-2 and O-2 are also measured.