On Pulsed Modes of the Glowing Corona Region

Resumo

A corona discharge is experimentally studied in atmospheric air on a needle electrode with the curvature radius 40 μm. For both electrode voltage polarities, but different discharge burning modes, repetitive current pulses with the FWHM ~200 ns are registered. It is shown that in a wide range of negative-polarity voltages the area of the glow registered in the vicinity of the needle has a spherical shape, and in the case of a positive polarity of the needle tip, starting from a certain voltage value, cylindrical streamers are formed from the spherical glow area, whose length increases with the voltage. It is found out that the size of the glowing spherical formations near the needle tip, given the same voltage value, is larger in the case of negative polarity than in the positive one. It is validated that the radiation of the second positive system of nitrogen in the UVspectral region dominates in the corona discharge emission spectrum before its transition into a spark discharge.