Electron-Capture Cross Sections of Ground-State O2+ Recoil Ions in Slow Collisions with H2 and O2

We report the measured total charge-transfer (electron-capture) cross sectionsfor the ground state O2+ (X2Àg) ions with H2 and O2 molecular gases in the collisionenergy range between 0.50 and 2 keV. The time-of-flight technique has been used tomeasure the fast neutral products from O2+ charge transfer reactions. The analyzedprocess has cross sections that continue to increase slowly, as a function of incidentenergy. Measured cross sections for O2+ H2, O2 systems are compared with previouslyavailable experimental and theoretical results in the literature