Residual charge density distribution measurement of surface leader with feedback electrostatic probe

A charge density distribution scanning system is fabricated using an electrostatic probe, which utilizes DC voltage feedback principle to nullify the electric field between the probe and charged insulator surface. A two-layer structure pipe is designed to lower the surface potential after discharge. In this way, the surface potential distribution caused by the residual charge of leader discharge under the impulse application voltage up to 40 kV can be measured. In this Letter, the residual surface charge density distribution under 23.5 kV application voltage is given, and the numerical characteristics of residual charge in the leader channel and streamer channel are analyzed.