Near-resonant charge transfer in collisions of N+ and O+ ions with inert gases

Total charge-transfer cross sections for ground-state and metastable N+ and O+ ions colliding with inert-gas atoms are investigated experimentally and calculated theoretically. The experimental cross sections of O+ and previously measured N+ cross sections are presented together with results compiled from the literature in a large energy range. Theoretical calculations are performed within the framework of the Smirnov (1973) and Demkov theories (1978). In most cases a two-state approximation is valid, providing overall good agreement between experimental and theoretical results.