Nanosecond surface discharge development using the computer simulation method

Abstract

The authors have analytically studied the experimental results of the nanosecond surface discharge by using a simulation model. The results used were obtained using the dust figure technique with a nanosecond square pulse generator under the following conditions: an applied voltage of 5–20 kV, a pulse width of 3, 5, 8,..., 920 ns, and a gas pressure of 50, 100, 150,..., 760 Torr. Three kinds of simulation models were used: the first was based on the continuity equations together with the Poisson’s equation, without any photoionization effects; the second examined the gas photoionization effect on the first model; and the third considered further the photoelectric effect on the insulation surface. From a series of computations, it was found that by using the third simulation model, the experimental results such as the developing length of the corona streamer and its velocity were roughly confirmed, and the field intensity at the streamer tip was also obtained. Finally, the photoelectric emission coefficient θm at the insulation surface was evaluated.