EFISH Measurements of Space Charge Waves after Streamer Corona

This experimental study focuses on the dynamics of volumetric charge and energy dissipation in the case of a single pin electrode streamer corona electric discharge generated in open atmosphere (P = 1 bar) with an alternating polarity high-voltage waveform, up to 100kV. Recent studies show that the volumetric electric charge deposited by the high-voltage pulse discharge greatly affects subsequent discharge parameters and morphology for surface and volumetric geometries. The initial discharge produces a wave of volumetric electric charge concomitant with a redistribution of the electric field that significantly influences the discharge pattern. The EFISH method (Electrical Field Induced Second Harmonic) was employed to perform non-intrusive measurements of the electric field magnitude and direction during, and after, a streamer corona discharge with both high temporal and spatial resolution. It was found that the volumetric charge of an initial pulse polarity occupies a zone up to 100mm from the pin electrode. The following halfcycle of the opposite polarity leads to a partial neutralization of the previous charge cloud and to the generation of a layer with a high-amplitude electric field, up to 50kV/cm. This layer prevents the propagation of the streamers at the next half-cycle.