Charge transfer from molecular hydrogen to stored O2+ and O3+ ions

The rate coefficients for charge transfer from H2 molecules to O2+ and O3+ ions have been measured at eV energies using an ion-storage technique. A single rate coefficient k(O3+, H2)=(7.15+-0.15) x 10/sup -9/cm3/s characterizes the O3+,H2 interaction, but the attenuation of the stored O2+-ion number due to charge transfer in a mixture of O2 and H2 gases exhibited a double time constant. Analysis employing the time dependence of the O2+-ion metastable-level mean lives resulted in the charge-transfer rate coefficients k(O2+(3P),H2)=(1.71+-0.15) x 10/sup -9/cm3/s and k(O2+(1D),H2)=(9.6+-0.6) x 10/sup -9/ cm3/s. The mean energy of the O2+ ions was 1.25(0.5) eV, while the O3+ ions were at 2.15(0.5) eV. The relationships to electron capture from H and from O2 by these ions are discussed