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

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 jd and position x) was experimentally investigated by optical emission spectrometry (OES). The measured characteristics I(λ)=f(p, jd, 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 Nem 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.