THEORETICAL-STUDIES ON NANOSECOND SURFACE DISCHARGE PHENOMENA OBSERVED USING LICHTENBERG FIGURE METHOD

The nanosecond surface discharge phenomena on the insulation plate have been studied using a Lichtenberg figure method. In the experimental setup voltages of + 7 to 22 kV, pressures of 150-760 Torr and pulse widths of 3-11 nsec were applied. The developing length of the positive corona streamer has been precisely measured against the applied voltage as a function of the pressure at a given pulse width. It was found that with increasing pressure there was an increase of inception voltage, while the time lag of corona streamer inception decresed. The developing velocity of charged particles on the insulation plate is discussed from a view point of a modified drift theory of charged particles. Finally, it is concluded that the detardation factor due to the photoelectric emission from the insulation plate plays a more important role in the corona streamer development than the electron collision ionization or the gas photoionization.