Infrared Laser Probing of Combustion and Energetic Molecule Decomposition Reactions in Shock Waves

Resonance and near-resonance absorption of frequency-stabilized, grating-tuned CW CO laser radiation have been used to measure real time CO and NO production in several combustion and energetic molecule reaction systems studied in a shock tube. In the resonance absorption studies in which the CO product was probed, examples of the extraction of key rate constants in several decomposition and oxidation reactions will be discussed. The NO product, which exhibits strong near-resonance absorption of the CO laser radiation at high temperatures and pressures, was probed in the decomposition of highly energetic molecules such as methyl nitrite and nitromethane. Additionally, an example of the use of the CO laser for the probing of H₂O under high temperature and pressure conditions in shock waves will also be reviewed.