LUMINESCENCE MEASUREMENTS OF AR+ + H2O AND N-2+ + H2O SUPRATHERMAL CHARGE-TRANSFER COLLISIONS - PRODUCT STATE DISTRIBUTIONS FROM H2O+A2A1-X2B1 ANALYSIS

Luminescence measurements of the Ar+ + H2O and N2+ + H2O charge transfer systems are reported at collision energies ranging from 0.6 to 783 eV at a maximum resolution of 0.5 nm (FWHM). Both systems produce H2O + A approximately 2A1-X approximately 2B1 emissions throughout the measured energy range. Approximate A approximately state vibrational populations are determined using known spectroscopic constants. At the highest energies investigated, the A approximately state population resembles a Franck-Condon distribution. At low collision energies, near-resonant vibrational levels of the A approximately are preferentially populated indicating dominance of large impact parameter charge transfer collisions. Population of high K vibronic sublevels, corresponding to high rotational excitation about the A rotational axis of H2O+, is observed in the nearest-resonant vibrational levels. A drop to near-zero population is observed for off-resonant levels at low collision energies that is associated with the dominance of the atom pickup channel at small impact parameters.