Role of ions in the abnormal glow of the plasma–cathode interface of neon glow discharges

Abstract

Experimental and theoretical studies of the luminescence of cathode zone of Ne/(Fe cathode) glow discharges are reported. The dependence of line intensity I( λ) on the discharge parameters (gas pressure p, current density j d and position x) was experimentally investigated by optical emission spectrometry (OES). The measured characteristics I( λ) =f( p, j d , p, x) were discussed based on complex modeling of the plasma–cathode interface. A few examples of Ne species excitation such as the electron–atom interaction and the participation of metastable Ne m atoms were considered. The fast Ne + ions interaction with Ne atoms and the cathode surface is concluded finally to be the dominating process affecting the line emission of all neon species occurring in the plasma–cathode interface.