Vibrational temperatures and gain coefficient measurements by using spontaneous radiation data obtained in a shock driven CO2—GDL

A method for determination of vibrational temperatures in vibrationally-nonequilibrated CO2-laser active medium for CO2, CO and NO admixture molecules is developed and described. The determination of vibrational temperatures of CO and NO molecules is based on spontaneous radiation intensity measurements in the 4.7 and 5.3 micron bands respectively and that of CO2 molecules is based on the simultaneous measurement of radiation intensity in 4.3 and 2.7 micron bands. The CO2 vibrational temperature measurements permitted restoration of the upper and lower laser levels populations and hence of the gain coefficient in CO2 laser transition. The vibrational temperatures of CO2, CO and NO molecules in CO2-GDL with the introduction of carbon monoxide or nitrogen monoxide instead of nitrogen in the chemically inert 0.1 CO2+0.4 N2+0.5 He and reactive CO+N2O+(N2+He) mixtures were measured. In these experiments the gain coefficient was measured by two independent methods: by probing laser technique and by restoration of the vibrational temperatures of CO2. The values of gain coefficient and vibrational temperatures were also calculated numerically.