Corona with Streamers in Atmospheric Pressure Air in a Highly Inhomogeneous Electric Field

Abstract

The paper presents research data on positive and negative coronas in atmospheric pressure air in a highly inhomogeneous electric field. The data show that irrespective of the polarity of pointed electrodes placed in a high electric field (>200 kV/cm), this type of discharge develops via spherical streamers even if the gap voltage rises slowly (£0.2 kV/ms). The start voltage of first positive streamers, compared to negative ones, is higher and the amplitude and the frequency of their current pulses are much lower: about two times and more than two orders of magnitude, respectively. The higher frequency of current pulses from negative spherical streamers provides higher average currents and larger luminous regions of negative coronas compared to positive ones. Positive and negative cylindrical streamers from a pointed to a plane electrode are detected and successive discharge transitions at both polarities are identified.

Experimental Simulation of Red Sprites in a Laboratory

“…An increase in U DC , in this case, will lead to a gap breakdown [33] . The data are in agreement with the results obtained with corona and diffuse discharges from a metal tip [29,34] , as well as with an apokampic discharge from a positive charged bent plasma channel between two pointed electrodes [28] . When a pointed electrode is a cathode (a negative tip) electrons move to a region where an electric field strength is lower, i.e.…”

“…Preliminary experiments have shown that such a discharge are red colored due to the emission of bands formed by spectral transitions of the 1+ system of a nitrogen molecule and are can be classified as a streamer discharge. This paper, unlike others dealing with laboratory modeling of red sprites in low-pressure air [15,[26][27][28][29][30][31] , has a significant difference in the form of an electrodeless discharge.…”

“…The experiment was aimed at determining the influence of the polarity of a high-voltage (HV) electrode on the formation of streamers at low air pressures, as well as fixing their color at pressures of 1 Torr ~ 3 Torr, at which the sprites still remain red. However, the color of the pulsed discharge at low pressures can be either blue or violet [15,[26][27][28][29][30][31] . DC voltage of positive or negative polarity from the U DC source was applied via a 3-m-long cable equipped with a 100-MΩ resistor to the additional electrodes mounted on the left flange (Figure 3a).…”

“…With a positive tip, electrons move to the tip, and positive ions, due to their greater mass, accumulate at the tip and amplify the electric field in this area. This facilitates the formation of a positive cylindrical streamer [29] . As a result, breakdown in an inhomogeneous electric field occurs at a positive polarity of an electrode with a small radius of curvature at a voltage 2-3 times lower than at a negative one (see, e.g., [33] ).…”

“…As a result, breakdown in an inhomogeneous electric field occurs at a positive polarity of an electrode with a small radius of curvature at a voltage 2-3 times lower than at a negative one (see, e.g., [33] ). At nanosecond voltage pulses and low pressures, the color of the discharges was blue or violet [23,[26][27][28][29][30][31] (without taking into account the influence of the interelectrode material [30] ). Under the conditions of the experiments, the color of plasma emission both in the region where streamers propagate and in the region near the electrodes was red, including at the air pressure in p = 6 Torr ~ 9 Torr, at which streamers were not observed.…”