Characteristics of the stabilized glow discharge in air

The discharge space between a positive cylindrical electrode (in the diameter range 0.3185-3.175 cm) and a coaxial outer electrode of diameter 58.1 cm has been irradiated by a radioactive beta -source to obtain a stable glow discharge in which streamers are absent. Onset electric gradient, voltage-current characteristics and electric gradient measurements at the anode surface in the presence of corona have been obtained. A modified form of the Townsend voltage-current characteristic has been derived which is in good agreement with the measured values for all conductor diameters. The surface gradient is found to be constant at about 5% below the onset value after establishment of the glow discharge, and to be independent of further voltage increase. Calculations suggest that this is consistent with a positive-ion mobility of 1.8* -4 m 2 V -1 s -1 .