Experimental study of the characteristics of Trichel pulses in the needle-plane negative corona discharge in atmospheric air

The results of an experimental study of the negative corona discharge in a needle-plane geometry are reported in this paper. The experiments were conducted in air at room temperature and atmospheric pressure. The impact of different parameters: the needle voltage, needle-plane distance, and the radius of curvature of the needle's tip on the frequency, DC current and the temporal characteristics of the pulses (rise time, fall time and the pulse width) was studied. Four different needles with radii of curvatures ranging from 19 μm to 55 μm were used. The needle-plane distance was varied from 6 mm to 3 cm. The applied voltage on the needle was varied from the onset voltage (−4 kV to −6 kV) to −10 kV. It was observed that the temporal characteristics of the pulses, such as rise time, were not a function of the radius of the curvature of the needle's tip, voltage level, or the needle-plane distance. The experimental data were compared with the results of numerical simulations, as well as with the experimental data published by Lama and Gallo. The experimental findings were found to be in a good agreement with Lama's and Gallo's work. Some discrepancies were found between the numerical and experimental results, and possible reasons for those are discussed.