IR double resonance study of rotational energy transfer in pure HCl

Abstract

The rotational relaxation of HCl (v=1) by HCl is studied by infrared double resonance using two chemical lasers. State-to-state rate constants are derived from the measurements by comparison with a computer simulation based on two different scaling laws. The ECS theory based scaling law seems to provide a better fit to the experimental data than does the exponential gap law. With both scaling laws a correct description of the double resonance is obtained by including multiple rotational quantum transitions.