A Pulsed-Field Ionization Photoelectron Secondary Ion Coincidence Study of the H2(+)(X, nu(+) = 0 - 15, N(+) = 1) + He Proton Transfer Reaction
Abstract
The endothermic proton transfer reaction, H2+(v+) + He yields HeH(+) + H(Delta E=0.806 eV), is investigated over a broad range of reactant vibrational levels using high-resolution vacuum ultraviolet to prepare reactant ions either through excitation of autoionization resonances, or using the pulsed-field ionization-photoelectron-secondary ion coincidence (PFI-PESICO) approach. In the former case, the translational energy dependence of the integral reaction cross sections are measured for v+ =0-3 with high signal-to-noise using the guided-ion beam technique. PFI-PESICO cross sections are reported for v(+) = 1-15 and v(+) = 0-12 at center-of-mass collision energies of 0.6 and 3.1 eV, respectively. All ion reactant states selected by the PFI-PESICO scheme are in the N(+) = 1 rotational level. The experimental cross sections are complemented with quasiclassical trajectory (QCT) calculations performed on the ab initio potential energy surface provided by Palmieri et al. [Mol. Phys. 98, 1839 (2000)]. The QCT cross sections are significantly lower than the experimental results near threshold, consistent with important contributions due to resonances observed in quantum scattering studies. At total energies above 2 eV, the QCT calculations are in excellent agreement with the present results. PFI-PESICO time-of-flight (TOF) measurements are also reported for v(+) = 3 and 4 at a collision energy of 0.6 eV. The velocity inverted TOF spectra are consistent with the prevalence of a spectator-stripping mechanism.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 22, 2005
- Accession Number
- ADA441239
Entities
People
- C. Y. Ng
- ChuanâChieh Chang
- D. J. Levandier
- Haowei Xu
- Rainer A. Dressler
- Tianqing Zhang
- X. N. Tang
- Y. Chiu
- Yantian Hou
Organizations
- University of California, Davis