The Method for Electric Field Distribution Measurement in Cathode Fall Region of an Abnormal Glow Discharge in Neon

Abstract

The Ne I spectral line shapes have been studied along the optical axis of an abnormal glow discharge with flat cathode. The observations are performed not only parallel (side-on) but also perpendicular (end-on) to aluminum cathode surface. The end-on recorded line profiles showed up to 30% larger half-widths than the side-on recorded line profiles from the negative glow region. The features of end-on line shapes are related quantitatively to the effect of dc Stark effect in the cathode fall region and plasma line broadening in negative glow region. The side-on spectral line shapes showing simultaneous shifting and splitting in the cathode fall region and available line shifts data for the dc Stark effect may enable the mapping of the electric field in the cathode fall region.