High-Voltage Streamer Propagation in the Long Discharge Gap: Role of Electrodes Geometry and Pulse Shape

Abstract

Numerical modeling of streamer development in 1-meter long discharge gap has been performed for atmospheric pressure air. The modeling was performed in 2D axisymmetric geometry using a drift-diffusion local field approximation [1-2]. The positive high-voltage pulse amplitude was varied from 200 to 1000 kV. The pulse rise time was 1, 10 and 100 ns. Streamer parameters were investigated as a function of the radius of high-voltage electrode, pulse amplitude and shape. The dependences of the propagation distance, plasma channel radius, current, velocity of the streamer on the pulse shape and geometry of the electrodes were analyzed. It was shown that changes in the pulse amplitude, anode radius, and voltage rise time do not cause a significant change in the field in the channel, which remains at a level E ~ 5 kV/cm. The electric field in the channel depends on the electrode radius only at small distances. The pulse rise time has practically no effect on the electric field in the channel, streamer’s velocity and propagation distance. On the contrary, the streamer’s length, velocity, current, and plasma channel diameter depend significantly on the anode radius.