Effect of the Electrodes Material on the Corona Discharge at Atmospheric Pressure

The effect of the electrodes material on negative corona discharge has been studied in point/plane configuration in the air at atmospheric pressure. Three materials (copper, aluminum and steel) were tested in experiments. Current/voltage characteristics indicate that currents related with steel electrodes are larger than those of copper and aluminum electrodes. The oscillograms giving the temporal evolution of the current for these three materials allowed us conclude that Trichel pulses with aluminum are more regular than those of copper or steel. The I-V characteristics of the three electrodes material are well fitted by the universal parabolic expression. The numerical coefficients for a parabolic fitting of the measured current-voltage characteristics for the negative corona were determined. Finally, it was established than the stability of the discharge is better with aluminum electrodes.