Experimental and theoretical investigation of optogalvanic effects

Research on the 594.5 nm optogalvanic effect in the Neon positive column discharge was performed. Absolute measurements of the effect per unit of absorbed laser power were performed for discharge radius-pressure products of 9.1 cm-Torr to 1.0 cm-Torr and for substaining direct currents of 1 to 16 mA. The effect was modeled in this regime by applying perturbation theory to key rate equations. The model predictions are in agreement with the experimental measurements. Associated measurements of absolute metastable densities indicate that the studied regime covers the transition from a discharge sustained primarily by single-step electron impact ionization to a discharge sustained primarily by two-step ionization via the 2p53s metastable levels.