The Chemical Dynamics of Highly Vibrationally Excited Diatomic Ions of Aerospace Relevance

Abstract : During this funding period, we have completed the PFI-PESICO measurements of the state-selected proton transfer reaction H2+(v+=0-15, N+=1) + He(Ne) -> HeH+ (NeH+) + H. The results of this experiment, together with the cross sections obtained by quasi-classical trajectory (QCT) calculations on this reaction system has been published in the Journal of Chemical Physics (JCP). In a separate theoretical study, which has also been published in JCP, we have performed time-dependent wave-packet calculations on the proton transfer collision of H2+(v+=0-6, N+=1) + He for comparison with the PFI-PBSICO measurements. This theoretical treatment includes the Coriolis coupling (CC) and thus represents the most rigorous theoretical calculation applied to an ion-molecule reaction system. The comparison of the theoretical and experimental cross sections indicates that the inclusion of CC in quantum scattering calculations is important for accurate cross section predictions of ion-molecule reactions. We have also obtained absolute cross sections for the collision-induced dissociation reactions of HD+(v+=0-5) [D2+(v+=0-5)] + He (Ne, Ar, Kr). The manuscripts for these experiments are being prepared for publication. To supplement the PFI-PBSICO experiments at the ALS, we have made significant progress in the implementation of the VUV-laser-PFI-PI technique with the TQDO apparatus for state-selected ion-molecule reaction studies.