Bright areas of radiation in low-pressure air when diffuse plasma jets meet
V.F. Tarasenko, N.P. Vinogradov, E.Kh. Baksht, D.A. Sorokin, D.S. Pechenitsin
Institute of High Current Electronics, Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: diffuse plasma jet, discharge in low-pressure air, interaction between streamers, bright area of luminescence, emission spectrum
Abstract
The glow of diffuse plasma jets (DPJ) is studied, which make it possible to simulate in low-pressure atmospheric air some properties of red sprites - pulsed discharges observed in the upper layers of the Earth's atmosphere at altitudes of 40-100 km. DPJs were initiated by the plasma of a pulse-periodic capacitive discharge created in a quartz tube between two external electrodes and propagated simultaneously in opposite directions. To form the DPJs, which moved towards each other, two pairs of ring electrodes were used, installed at a distance of 66 cm. When unipolar voltage pulses from generators were applied to each pair of ring electrodes with a delay of hundreds of nanoseconds, bright areas of luminescence (BAL) similar to those observed in the lower area of the column sprites appeared. It has been established that at a generator voltage of 7 kV, the optimal air pressure for the appearance of BAL is 1-2 Torr. It is shown that BALs arise due to the interaction of streamers that make up the DPJs. The speed of propagation of the DPJ front was measured for the positive polarity of voltage pulses applied to the ring electrodes. Photographs and emission spectra of the DPJs, as well as bright regions in the DPJs, were obtained. Using the SPECAIR program, plasma parameters were calculated in different areas of diffuse plasma jets. It has been established that in the region where BALs appear, the average value of the electron temperature decreases.
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