OPTOGALVANIC AND OPTOPOTENTIAL SIGNALS IN A GLOW-DISCHARGE REVEAL ELECTRODE COUPLING EFFECTS

This study considers the coupling effect between the cathode and anode regions-the two most important regions in a glow discharge. Cathode a nd anode processes are tightly coupled by electron and ion coupling ef fects. Both electron and ion coupling effects were observed by studyin g excited Ar atoms in the cathode and anode regions and observing lase r-induced space charge variations and the optogalvanic effect. Laser-i nduced space charge variations in the glow discharge were observed by the change in potential of an electrical probe. This signal, called th e optopotential signal, provides useful information about the cathode and anode processes, and may become another useful spectroscopic detec tion method.