Influence of space charge on corona growth in a positive point-plane gap in air subjected to a voltage impulse

The effect of space charge on the electric field in a positive point-plane gap is calculated by the use of image charges placed at appropriate points on the axis of symmetry of the electrode system. Field equations obtained from the calculations are tested for validity by applying them to prebreakdown corona-current pulses, and they are used to calculate the time interval between successive pulses. Good agreement is obtained with an experimentally measured pulse interval for similar conditions. The accuracy and limitations of the method are discussed.