Number density and temperature of acetylene in hot-filament and arc-jet activated CH4/H-2 gas mixtures measured using diode laser cavity ring-down absorption spectroscopyстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:Continuous-wave cavity ring-down spectroscopy (CW-CRDS) with an external cavity diode laser has been used to make diagnostic measurements of acetylene absorption in hot-filament and DC-arc plasma jet reactors operating with 1% CH, in H, and less than or equal to0.8% CH4/H-2 in excess Ar, respectively, and used for diamond chemical vapour deposition. The acetylene was widely distributed throughout the reactor, extending well beyond the regions of highest thermal activation as a result of diffusion processes. The average acetylene concentration was determined as (2.9+/-0.6) X 10(13) molecules cm(-3) in the hot filament reactor and (1.2+/-0.2) X 10(14) molecules cm(-3) in the DC arc jet reactor, accounting for similar to1.7% and 40% of the total C budget in the respective cases. The average acetylene gas temperature along the viewing column was 550+/-150 K in both environments. Variations in the concentration and temperature of acetylene with the gas feed composition and input power processing conditions for the two reactors are presented. The experiments demonstrate the effectiveness of near-IR diode laser CRDS as a probe of highly luminous environments. (C) 2003 Elsevier Science B.V. All rights reserved.