Superradiance emitted by N2+ and N2 as a result of a beam–plasma discharge in a helium–nitrogen mixture

A beam–plasma discharge initiated by a high-current electron beam of nanosecond duration in a narrow range of partial pressures in He–N₂ mixtures generated superradiance simultaneously at 391.4 nm (N₂⁺) and 337.1 nm (N₂) . In the presence of He the superradiance of N₂ was emitted at lower nitrogen pressures. A luminescence pulse of N₂⁺ appeared 15–18 ns after that of N₂.