A new method is developed for measuring the transient potential distribution of surface discharge. The measuring system consists of a BGO Pockels crystal, an Ar ion laser, a beam expander, a streak camera and a CCD camera. The potential profile of a stepwise surface discharge along a linear path of 50mm in length is measured with high space and time resolution: 0.1mm and 2 ns in minimum resolution.
The electric field component parallel to the direction x of the streamer propagation (E
x) is easily computed from the potential profile. E
x near the tip of a negative surface streamer is around 24 kV/cm. There is no significant difference between the profiles of the potential and E
x around the tip of a feather-shape streamer and those of a sector-shape streamer.
抄録全体を表示