Evolyutsiya otritsatel'noy korony v rezhime ogranicheniya toka razryada: perekhod ot impul'sno-periodicheskogo rezhima k statsionarnomu goreniyu

The evolution of burning modes of a weak-current corona discharge in a diode filled with atmospheric air, having a pointed cathode and a flat anode, has been investigated. A theoretical description is performed in terms of an axisymmetric multifluid plasma model, including the kinetics of 9 types of particles and 25 plasma-chemical reactions. A discharge in a gap 10 mm long, with a needle-like cathode having a tip curvature radius of 100 μm, a source voltage of 8 kV, a ballast capacitance of 100 pF and a circuit ballast resistance of 1 MΩ, is described in detail. It is shown, both experimentally and theoretically, that the discharge has a lifetime of 180 μs and occurs in four clearly different stages under these conditions: (1) dark breakdown delay phase (0–20 μs); (2) Trichel pulse phase with a variable on–off time ratio and quasi-steady-state corona current component (20–80 μs); and (3) intermediate phase of monotonically rising weak current (80–130 μs), which ends with a vibrational transition to the (4) steady-state phase (130–180 μs), having a typical structure of glow discharge. The tendencies to a change in the corona discharge parameters with a variation in the feed voltage are analyzed. The results of theoretical calculations are in good agreement with the experimental data.