Characteristics of superequilibrium pumping in a CO2 gasdynamic laser with a CO + N2O reactive mixture

Shock-tube experiments demonstrate that, under superequilibrium pumping, the CO + N2O reaction occurs in a nonequilibrium fashion, leading to a significant excitation of the asymmetric mode of CO2. This in turn leads to a twofold or threefold increase in IR radiation intensity in relation to an inert comparison mixture. These effects are associated with a significant increase in the vibrational temperature of the asymmetric T3 mode under superequilibrium pumping, which depends on the content of impurities in the mixture. Trace amounts of uncontrolled impurities of less than 0.1 percent can have a considerable effect on the superequilibrium pumping.