Experimental and theoretical investigation of the optogalvanic effect in the helium positive column

A linear, steady-state analytical model of the optogalvanic effect in a positive column on the 587.6-nm He transition is presented. Absolute measurements of the optogalvanic effect in a positive column on the 587.6-nm He transition are reported. The model and the experiment are found to agree over a substantial range of direct currents and over a factor of 10 in column-radius-pressure product. This model relates the absolute magnitude of the optogalvanic effect on one transition to a known ionization rate. The structure of this model should be useful in determining ionization rates of electronically excited levels from optogalvanic measurements.