Charge transfer and ion-atom interchange reactions of water vapor ions

Charge-transfer cross sections resulting in either the production or the loss of H2O+ were studied in the energy range 1 to 400 ev by using the crossed ion and neutral beam technique and employing mass analysis of the primary and product ions. The ions incident on H2O neutral beams were N+, O+, N2+, NO+, O2+ and Ar+; the H2O+ ion beams were incident on neutral beams of O2, NO, and H2O. The effects of the excited ions in the incident beam upon the cross sections were also investigated. The cross section for a rearrangement collision, H2O+ + H2O → H3O+ + OH, was also measured. The implications of these results to atmospheric models are discussed.