The purpose of this note is to describe a novel application of supersonic molecular beam spectrometry to the study of combustion processes in piston engines. In this technique, combustion gases are cooled by expansion from a nozzle integral with the cylinder head wall into an adjacent vacuum chamber. The rotationally cooled combustion products are analyzed by laser-induced fluorescence spectrometry with gigaHertz spectral resolution. Because of the rapid passage of the sample into a relatively collision-free state, it should be possible to isolate and identify intermediates as well as the final reaction products. Time resolution can be obtained by synchronizing the pulsed laser excitation source to the engine cycle.
W. B. Whitten, "Supersonic Jet Sampling for Combustion Diagnostics," Appl. Spectrosc. 40, 104-106 (1986)