State-to-state differential and relative integral cross sections for rotationally inelastic scattering of H2O by hydrogen

C-H Yang; G Sarma; D H Parker; J J ter Meulen; L Wiesenfeld

doi:10.1063/1.3589360

State-to-state differential and relative integral cross sections for rotationally inelastic scattering of H2O by hydrogen

J Chem Phys. 2011 May 28;134(20):204308. doi: 10.1063/1.3589360.

Authors

C-H Yang¹, G Sarma, D H Parker, J J ter Meulen, L Wiesenfeld

Affiliation

¹ Radboud University Nijmegen, Institute for Molecules and Materials, Nijmegen, The Netherlands.

PMID: 21639441
DOI: 10.1063/1.3589360

Abstract

State-to-state differential cross sections (DCSs) for rotationally inelastic scattering of H(2)O by H(2) have been measured at 71.2 meV (574 cm(-1)) and 44.8 meV (361 cm(-1)) collision energy using crossed molecular beams combined with velocity map imaging. A molecular beam containing variable compositions of the (J = 0, 1, 2) rotational states of hydrogen collides with a molecular beam of argon seeded with water vapor that is cooled by supersonic expansion to its lowest para or ortho rotational levels (J(KaKc) = 0(00) and 1(01), respectively). Angular speed distributions of fully specified rotationally excited final states are obtained using velocity map imaging. Relative integral cross sections are obtained by integrating the DCSs taken with the same experimental conditions. Experimental state-specific DCSs are compared with predictions from fully quantum scattering calculations on the most complete H(2)O-H(2) potential energy surface. Comparison of relative total cross sections and state-specific DCSs show excellent agreement with theory in almost all details.