Exploratory Research on Population Inversions in Gaseous Explosions

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 1∑ state. It is suggested that this technique may be widely applicable as a tool for determining initial vibrational population distributions of newly formed molecules.