Trichel Pulse Characteristics in Negative dc Corona Discharge

Trichel pulse characteristics of needle-to-plate electrode were studied. The experimental results indicate that time-averaged corona current increased with the voltage, but the peak pulse current decreased with the voltage; when the averaged electric field strength reached about 7.6kV/cm, Trichel pulse was not steady and easily converted to pulseless corona. The curvature radius had influence on the current amplitude of Trichel pulse, and higher current amplitude was obtained when discharge needle with bigger curvature radius was used as cathode. The experiment also indicate that the electron released from the cathode by field emission might play an important role in the development of Trichel pulse, and hot electron emission might also play some role.