Primary and Afterglow Emission from Low-Temperature Gaseous Nitrogen Excited by Fast Electrons

Measurements were made of the primary and afterglow emission decay times of some of the emitting species in an expanded nitrogen flow when excited by a 10-kV electron beam. Both the first negative system of N2+ and the second positive system of N2 were observed in the afterglow to persist for about 2×10−6 sec. The origin of the afterglow is explained by the possible transfer of energy from ground-state N2+ ions and secondary electrons to ground state N2 molecules. This is substantiated by observations of the departure from a Boltzmann distribution of the rotational energies in the N2 molecules.