Active Nitrogen

It is shown that Mitra's hypothesis which attributes the Lewis-Rayleigh afterglow of nitrogen to the excitation of the molecules by a three-body collision, N₂⁺(X^')+e+N₂=N₂(B-state)+N₂(A-state),cannot account for the spectrum of the auroral afterglow in which there is incontrovertible evidence that ions in the N₂⁺(X^') state are present. It is proposed that the most important reactions occurring in nitrogen afterglows and probably in polar auroras are the dissociative recombination, $N₂⁺+e={N}^{{'}}+{N}^{{'}{'}} (nitrogen{{0ex}{0ex}}atoms{{0ex}{0ex}}in{{0ex}{0ex}}metastable{{0ex}{0ex}}states)),$and collisions of the second kind involving very slow electrons and metastable atoms.