Atmospheric Pressure Acetylene Detection by UV Photo-Fragmentation and Induced C2 Emission

Abstract

Detection of C2H2 via UV photo-fragmentation, followed by monitoring the C2 d3Πg– a3Πu fluorescence, is explored at atmospheric pressure and at temperatures of 295 K, 600 K, and 800 K, for excitation wavelengths 210 to 240 nm using a broadband laser source (~3 cm−1 fwhm). At the lower temperature, C2 emissions correlate closely with C2H2 Ã←X absorption bands, and the excitation spectra suggest a higher-transition probability for the v″ 4 = 2 and 3 states than for the v″ 4 = 0 and 1 states. As temperature increases, the excitation spectra exhibit a higher nonresonant background.