Measuring and Modeling Streamer Velocity at an Air Discharge in a Highly Inhomogeneous Electric Field

The velocities of the positive and negative streamers in the air at atmospheric pressure are experimentally, theoretically, and computationally studied at the discharge of the needle–plane gap by the nanosecond voltage pulses. The data on variation in the streamer’s velocity are obtained, including the data at various amplitudes of the voltage pulses. It is established that the streamer’s velocity varies along its motion and is maximum at the electrode with a small curvature radius and at the planar electrode. It is demonstrated that the character of variation in the computational values of the streamer’s velocity over the gap agrees with the experimental data.