Excitation processes in the positive column of electrical discharges in inert gases

The variation with the current i, of the intensity, I, of neon spectral lines emitted from low pressure positive column discharges has been studied as part of an investigation of excitation processes in these discharges. The results indicate that two-step excitation is important for many neon lines. Measurements of emission line profiles have been made using a pressure scanned Fabry-Perot interfermometer. High resolution absorption measurements have been made to give data on tha population densities of the lower excited states, and their variation with pressure and current, to assist in interpreting the intensity-current (I-i) results.