Association Reaction of Gaseous C(2)H(4) in Femtosecond Laser Filaments Studied by Time-of-Flight Mass Spectrometry

[Image: see text] Association reactions by femtosecond laser filamentation in gaseous C(2)H(4) were studied by time-of-flight mass spectrometry of neutral reaction products. Direct sampling from the reaction cell to a mass spectrometer via a differential pumping stage allowed the identification of various hydrocarbon molecules C(n)H(m) with n = 3–7 and m = 4–7, which includes species not observed in the previous studies. It was found that products containing three and four carbon atoms dominate the mass spectrum with smaller yields for higher-mass species, suggesting that carbon chain growth proceeds through the reaction with C(2)H(4) in the reaction cell. The product distribution showed a clear dependence on the laser pulse energy for filamentation.