Experimental determination of quantum state resolved differential cross sections for the hydrogen exchange reaction H+D2→HD+D

Abstract

We have carried out a systematic crossed molecular beam study of the hydrogen exchange reaction in the H+D2→HD+D isotopic form at two collision energies: 0.53 and 1.28 eV. The Rydberg atom time-of-flight method was used to measure the D-atom product angle-velocity distribution. For the first time ro-vibrational quantum state resolved differential cross sections for the title reaction were measured, which can directly be compared to theoretical predictions at this detailed level. Experimental results are compared to theoretical predictions from both quasi classical and quantum mechanical calculations on different potential energy surfaces as well as to earlier experiments. A general good agreement is found for the converged quantum mechanical calculations with indications that the Boothroyd-Keogh-Martin-Peterson potential energy surface is better suited to describe the dynamics of the reaction. For the higher collision energy the quasi classical trajectory calculations reproduce the experimental data quite well, whereas they fail to describe the situation at the lower collision energy especially with respect to angular resolved differential cross sections.

Chemical reaction dynamics of Rydberg atoms with neutral molecules: A comparison of molecular-beam and classical trajectory results for the H(n)+D2→HD+D(n′) reaction

“…On the other hand, intense beams of ͑neutral͒ RA can be produced with well-defined collision energies using now wellestablished technology. 15,16 In a recent report, we have presented the results of an experimental study of reaction ͑1͒ carried out using a crossed molecular-beam apparatus. 17 The state-resolved DCS was measured at two collision energies.…”

“…It is well known that the lifetime of the RA is extremely sensitive to the l-quantum number and scales roughly as n 3 l 2 for high-lying states. 33,34 Indeed, Schneider et al 15 found it necessary to use external fields in the generation of RA to guarantee sufficiently large l, and thus long enough lifetimes, to complete the experiment ͑our experiments rely on the same techniques 16 ͒. Thus, we must consider whether the reactive collision will induce ionization or transitions to low-l states that spontaneously emit.…”

Velocity map imaging the dynamics of the reactions of Cl atoms with neopentane and tetramethylsilane

“…The experimental data were obtained using both PHOTOLOC 54,55 and dual molecular beam 56 experimental methods, combined in each case with VMI of the HCl products, and comparisons are drawn between the two approaches.…”

HF( v′ = 3) forward scattering in the F + H 2 reaction: Shape resonance and slow-down mechanism

“…A full quantum state resolved crossed-beams scattering study on the F ϩ H 2 reaction has been carried out by using the H-atom Rydberg tagging time-of-flight (TOF) method (22)(23)(24)(25)(26). The new experimental apparatus used for this experiment is described in ref.…”