title: Kinetic measurements of the C2H5O2 radical using time-resolved cavity ring-down spectroscopy with a continuous source.
abstract: We report on the design of a time-resolved, high duty-factor cavity ring-down apparatus utilizing a continuous laser and detail a technique for the accurate and precise measurement of effective reaction rate constants with it. This report complements an earlier paper concerning the measurement of the absolute absorption cross-sections, σP, of reactive intermediates. To demonstrate the performance of the new technique, we have measured the decay rate of ethyl peroxy radicals by monitoring the Ã←X̃ origin band of the G-conformer of these species. A measured value kobs∕σP = 1.827(45) × 10(7) cm/s was determined and it, along with the previously measured value of σP, was used to derive the value of kobs = 9.66(44)×10(-14) cm(3)/s, for the effective rate constant for ethyl peroxy self-reaction (all uncertainties are 1 σ). The present value of kobs is compared to those previously reported, and sources of systematic errors and their impact are discussed.
authors.affiliation: Department of Chemistry, The Ohio State University, 120 W. 18th Avenue, Columbus, Ohio 43210, USA.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Melnik
authors.forename: Terry A
authors.initials: TA
authors.lastname: Miller