Detection and Characterization of Reactive Chemical Intermediates Using Cavity Ringdown Spectroscopy

Abstract

Cavity ringdown spectroscopy is a powerful technique for detecting reactive chemical intermediates in a variety of circumstances. The characterization of the ethyl peroxy radical in a variety of ways using different ringdown techniques is used as an example to illustrate the diverse capabilities. Several results are discussed including the room temperature, moderate resolution \(\widetilde{A}\)–\(\widetilde{X}\) spectrum and the jet-cooled, rotationally resolved \(\widetilde{A}\)–\(\widetilde{X}\) spectrum of ethyl peroxy. The concept of dual wavelength cavity ringdown spectroscopy is explored and its utility is demonstrated by a measurement of the \(\widetilde{A}\)–\(\widetilde{X}\) absorption cross section of ethyl peroxy. The self-reaction kinetics of ethyl peroxy are also studied by means of cavity ringdown spectroscopy with a continuous source. The capability of CRDS to measure dynamical effects is illustrated by work on a closely related radical, hydroxy ethyl peroxy radical.KeywordsAbsorption Cross SectionOptical Parametric OscillatorPeroxy RadicalRaman CellRotational ContourThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.