Active Nitrogen

Abstract

The paper examines the remark of Kaplan in a recent communication that while contributions made by me to the problem of active nitrogen will play a part in the explanation of the mode of excitation of the auroral after-glows, yet the principal reactions occuring in the same are not those proposed by me. (The reaction was proposed to explain the excitation of the familiar nitrogen afterglow, also called Lewis-Rayleigh glow.) It is stressed that, contrary to Kaplan's view, the strengthening of the Vegard-Kaplan bands and of the first positive bands originating in ${v}^{\ensuremath{'}}=11$ in the later stage of the auroral afterglow, does not really contradict the reaction proposed. These observations merely show that factors not present in the Lewis-Rayleigh afterglow are operative in the auroral afterglows.Attention is drawn to the fact that the persistence of the first negative bands throughout the entire duration of the auroral afterglow shows that nitrogen ions in the $\mathrm{N}_{2}^{+}({A}^{\ensuremath{'}}^{2}\ensuremath{\Sigma})$ state must have long life. They thus have a chance of reacting with other particles (collision of the second kind) producing effects not observed in the Lewis-Rayleigh glow. The long life of the $\mathrm{N}_{2}^{+}({A}^{\ensuremath{'}}^{2}\ensuremath{\Sigma})$ ions further helps to explain the failure to obtain absorption in even long columns of the glowing gas (Lewis-Rayleigh glow).In conclusion it is stressed that the findings of Kaplan that $\mathrm{N}_{2}^{+}({X}^{\ensuremath{'}})$ ions persist in the auroral afterglow throughout its entire duration and also that the alternative reactions proposed by him start with these ions support my hypothesis that active nitrogen is nitrogen ions in the $\mathrm{N}_{2}^{+}({X}^{\ensuremath{'}})$ state.