title: State-to-state dynamics of high-n Rydberg H-atom scattering with H2: inelastic scattering and reactive scattering.
abstract: The state-to-state dynamics of high-n Rydberg H-atom scattering with para-H2 at the collision energies of 0.45 and 1.07 eV have been studied using the H-atom Rydberg tagging time-of-flight technique. Both the inelastic scattering and reactive scattering are observed in the experimental time-of-flight spectra. The products H2(v', j' = odd) come only from reactive scattering and present clearly forward-backward asymmetric angular distributions, which differ from those of the corresponding ion-molecule reaction. The products H2(v', j' = even), however, come from both reactive scattering and inelastic scattering. Simulating the rotational distribution from reactive scattering, we found that most of the H2(v', j' = even) products come from inelastic scattering. The angular distributions of the product H2(v', j' = even) are consistent with what is predicted by the conventional textbook mechanism of inelastic scattering, and are a little different from those of the corresponding ion-molecule inelastic scattering. These results suggest that the effect of Rydberg electron could not be neglected in describing the differential cross sections of H* + para-H2 scattering. From the simulation, the branching ratios of the inelastic scattering channel were determined to be 66% and 79% at the collision energies of 0.45 and 1.07 eV, respectively.
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China. kjyuan@dicp.ac.cn xmyang@dicp.ac.cn.
authors.forename: Shengrui
authors.initials: S
authors.lastname: Yu
authors.forename: Shu
authors.initials: S
authors.lastname: Su
authors.forename: Dongxu
authors.initials: D
authors.lastname: Dai
authors.forename: Kaijun
authors.initials: K
authors.lastname: Yuan
authors.forename: Xueming
authors.initials: X
authors.lastname: Yang