Eur. Phys. J. D 38, 15-20 (2006)
https://doi.org/10.1140/epjd/e2006-00018-2

Probing spin-orbit quenching in Cl (²P) + H₂ via crossed molecular beam scattering

Combustion Research Facility, Sandia National Laboratory, 7011 East Ave., Livermore, CA, 94550, USA

Corresponding author: ^a chand@sandia.gov

Received: 17 August 2005
Revised: 2 December 2005
Published online: 31 January 2006

Abstract

In our previous work we investigated electronically non-adiabatic effects in using crossed molecular beam scattering coupled with velocity mapped ion imaging. The prior experiments placed limits on the cross-section for electronically non-adiabatic spin-orbit excitation and electronically non-adiabatic spin-orbit quenching . In the present work, we investigate electronically non-adiabatic spin-orbit quenching for which is the required first step for the reaction of Cl^* to produce ground state HCl+H products. In these experiments we collide Cl (²P) with H₂ at a series of fixed collision energies using a crossed molecular beam machine with velocity mapped ion imaging detection. Through an analysis of our ion images, we determine the fraction of electronically adiabatic scattering in Cl^* +H₂, which allows us to place limits on the cross-section for electronically non-adiabatic scattering or quenching. We determine the following quenching cross-sections σ_quench(2.1 kcal/mol) = 26 ±  21 Å², σ_quench(4.0 kcal/mol) = 21 ±  49 Å², and σ_quench(5.6 kcal/mol) = 14 ±  41 Å².