The infrared and ultraviolet radiation emitted by excited species in low-pressure gaseous oxygen-acetylene explosions is studied with a view toward establishing the population distribution of selected energy levels. In the ultraviolet, cavity techniques are employed, and a relative enhancement of several electronic transitions in CH and OH radicals is observed. In the infrared, the emission from excited CO2 molecules is studied immediately following the passage of a fast chemical detonation wave and evidence is found for an enhanced population of the high vibrational levels of CO2 molecules in the 1Σ state. It is suggested that this technique may be widely applicable as a tool for determining initial vibrational population distributions of newly formed molecules.
Supplement on Chemical Lasers
I. Wieder, R. R. Neiman, and A. P. Rodgers, "Exploratory Research on Population Inversions in Gaseous Explosions," Appl. Opt. 4, 187-192 (1965)