CN production efficiencies from active nitrogen-hydrocarbon flames

Various hydrocarbons have been reacted with active nitrogen in a supersonic flow system. The resulting chemiluminescence was invariably dominated by CN
A^{2} \Pi
and
B^{2} \Sigma+ \rightarrow X^{2}\Sigma+
emission. The intensity of this emission and the excited-state vibrational temperatures were strongly dependent upon the reactant hydrocarbon. Photon yields as high as 18.5 percent were measured for CN
A^{2} \Pi \rightarrow X^{2}\Sigma+
emission when C
2
F
4
was used as a reactant, which makes this system a very promising chemically pumped laser candidate. Calculations have shown that if the populations in the electronically excited states can be vibrationally cooled, it should be possible to achieve positive gain in the system.