Guidedhyphen;ion beam measurements of N++H2O chargehyphen;transfer and chemical reaction channels

摘要

Guidedhyphen;ion beam measurements of N++H2O chargehyphen;transfer and chemically reactive channels are presented for collision energies ranging from 0.1 eV to 20 eVthinsp;c.m. The chargehyphen;transfer reaction is not as efficient as expected considering the favorable Franckndash;Condon overlap at resonance. The analysis of producthyphen;ion timehyphen;ofhyphen;flight spectra demonstrates that energy transfer is efficient in orbiting collisions at all investigated collision energies. At low collision energies, formation of NO+, and HNO+and/or NOH+, is observed. The chemically reactive channels exhibit a near 1/ETdependence at low collision energies. Above 0.5 eV, the HNO+/NOH+cross section drops abruptly below the instrumental sensitivity. The NO+cross section exhibits a minimum at 1.2 eV, followed by an increase in cross section with energy reaching a maximum of 4times;10minus;16cm2at 7 eV before decreasing again. The decline at higher energies is partly attributed to a dissociative loss of the product ions. O+formation is observed at and above the thermodynamic threshold associated with the O++N+2H asymptotic limit.