Features of Glow Discharge burning between a hollow cathode and a mesh anode

Abstract

The article is devoted to an experimental study of the features of the combustion of a glow discharge between a hollow copper cathode and a mesh anode in a longitudinal air flow. The cylindrical channel of the discharge chamber was formed by five glass sections separated by copper plates, which served as probes for measuring the plasma potential. Air flowed through the hollow cathode into a cylindrical channel. The anode was a metal grid of a copper plate 1.5 mm thick with holes uniformly located on it with a diameter of 1 mm. The distance between the hollow cathode and the mesh anode was 6.5 cm. Air pressure P, its velocity V, discharge current I and its voltage U varied respectively in the ranges: P = (6. 4 - 19) kPa, V = (0 - 10) m / s, I = (5-100) mA, U = (1. 0 – 2. 0) kV. The current-voltage characteristic had a negative differential resistance. By changing the ballast resistance, the forward and reverse branches of the current-voltage characteristic were removed. It was found that in the range of discharge currents I = (40-80) mA, these branches do not coincide, that is, hysteresis phenomena were observed. In the ascending branch of the current-voltage characteristic in the region of the current strength I = 80 mA, the discharge voltage increases sharply from U = 1. 2 kV to U = 1.6 kV. In this case, the discharge glow becomes more intense, wider and brighter, and the structure of light and dark zones along the discharge chamber also changes. Characteristic photos of the discharge are given. The formation of luminous and dark gaps inside the positive column of the discharge and their movement towards the anode was detected.