Partial discharge and breakdown characteristics on needle/dielectrics composite electrode systems under pulse voltage

Studied the discharge characteristics on the composite electrode under a pulse voltage in N_2. The configuration is a needle-plane one, in which the needle is in contact with solid dielectrics, with a narrow gap. The configuration has a plurality of places of the local high field, namely a needle tip and another a triple junction. To examine a local corona behavior, we used ZnO for the needle electrode. Consequently, discharge voltages changed depending on the polarity of applied voltage and the kind of dielectric