POSITIVE CORONA FROM TWO INTERACTING THIN POINTS IN AIR.

A theoretical and experimental analysis confirms that positive corona from two interacting points always starts with the burst-pulses mode irrespective of the gap geometry. For applied voltages above the inception value, the functional dependence of the pulse repetition rate on the gap geometry is also studied. As the points are brought together (i. e. , the interaction strength increases) the pulse repetition rate decreases for the same applied voltage. Consequently, the pulse repetition rate will reduce more and more with the increase of the number of interacting points, and ultimately, the discharge tends to be continuous in mode (positive glow). This lends weight to L. Loeb's theory for glow formation. A new formulation for this theory is presented. The postulates necessary for positive-glow formation are discussed and a criterion for the transition from burst-pulses mode to glow mode is found. The computed inception voltages, and also the computed glow voltages-being dependent on the gap geometry-are compared with those measured experimentally.