Investigation of the microchannel structure in the initial phase of the discharge in air at atmospheric pressure in the “pin (anode)-plane” gap

• Published in: Physics of plasmas 2020-12, Vol.27 (12)
• Main Authors: Almazova, K. I., Belonogov, A. N., Borovkov, V. V., Kurbanismailov, V. S., Khalikova, Z. R., Omarova, P. Kh, Ragimkhanov, G. B., Tereshonok, D. V., Trenkin, A. A.
• Format: Article
• Language: English
• Subjects: Discharge; Electric field strength; Electrical resistivity; Electron energy; Microchannels; Microstructure; Plasma physics; Temperature
• ISSN: 1070-664X; 1089-7674
• DOI: 10.1063/5.0026192

The results of studies of the microstructure in the initial phase of the discharge in air in the gap between the pin and a plane 1.5 mm long are presented. Measurements show that within 15 ns after breakdown, the channel is a bundle of a large number of microchannels, the current in the channel grows almost linearly up to 1 kA, and the electron concentration reaches 2 × 1019 cm−3. Taking into account the experimental data, the electron temperature dynamics in a separate microchannel was calculated. It was found that the average electron temperature is from 4 to 8 eV, the electric field strength is ∼300 kV/cm, and the electrical conductivity is ∼10 Ω−1 cm−1. The obtained results indicate that it is the microstructure of the discharge that determines the relatively high values of the average temperature of electrons in combination with a sufficiently high degree of ionization.