Infrared emission by active nitrogen II. The kinetic behaviour of N ₂ (B ³ n II ₂ )

The kinetics of the emission of low levels ($\upsilon $ = 0-4) of N$_{2}$(B $^{3}\Pi _{\text{g}}$) in active nitrogen have been studied in nitrogen and in argon carriers. In argon carriers at low pressures, these levels are populated by emission of the Y bands N$_{2}$(B $^{\prime}$ $^{3}\Sigma _{\text{u}}^{-}$ $\rightarrow $ B$^{3}$$\Pi _{\text{g}}$) and the 1+ bands (B $^{3}$$\Pi _{\text{g}}$) $\rightarrow $ A $^{3}\Sigma _{\text{u}}^{+}$, $\upsilon $ = 7-13) followed by collision induced transitions to the B state for which the rate coefficient is found to be $ca$. 2 $\times $ 10$^{-13}$ cm$^{3}$ molecule$^{-1}$ s$^{-1}$. In nitrogen carriers the efficient quenching of N$_{2}$(B) and N$_{2}$(B$^{\prime}$) by N$_{2}$ produces a somewhat similar population of N$_{2}$(A) and N$_{2}$(B). The dependence of the emission kinetics on [N] and its quenching by CO$_{2}$ are shown to arise from removal of the N$_{2}$(A) precursor by N or by CO$_{2}$.