Spectral Study of Active Nitrogen Flames Exhibiting CN ``Tail'' Bands

Abstract

Flames of active nitrogen and simple chlorinated hydrocarbons which exhibit several zones defined by differences in intensity and spectra have been examined under a variety of conditions of flow rate, pressure, added impurities, and burner configuration. One of these zones exhibited strong emission arising from the CN ``tail'' bands, i.e., bands originating in high vibrational levels of the B <sup>2</sup>Σ state. Qualitative spectral evidence is consistent with the assumption that the chemical processes responsible for the emission from the different zones all produce CN selectively in the A <sup>2</sup>Π state but with different vibrational distributions, and that population of B <sup>2</sup>Σ occurs through interaction of mutually perturbing rotational levels of A <sup>2</sup>Π and B <sup>2</sup>Σ and through collision‐induced transfer from unperturbed levels in A <sup>2</sup>Π. As an incidental aspect of the work it has been found that traces of air in the N<sub>2</sub> supply were helpful for production of the ``pink'' nitrogen afterglow.