Dynamics of the gas/liquid interface from laser molecular beam scattering

Abstract

We report the results of a laser molecular beam scattering study of liquid surfaces. Molecular iodine is used as a probe molecule and its number density and quantum-state distribution is determined before and after scattering from the surface of a liquid by laser-induced fluorescence (LIF). Time resolution of the LIF signal allows us to separate processes of direct inelastic scatter from trapping followed by desorption. Here we focus mainly on the latter process and obtain data on the kinetics of desorption and the activation energy of desorption together with insights into the dynamical processes that lead to trapping and desorption.