Conditions for near-electrode contraction of a discharge in a combustion-product plasma

The article presents the results of an experimental investigation of the near-electrode processes occurring for a transition from a diffuse to a constricted type of discharge. The investigations were carried out under laboratory conditions on devices simulating a combustion-product plasma in the near-electrode layers of real MHD generators. The critical current density of the diffuse discharge is obtained as a function of the anode temperature and the plasma conductivity. A relationship is established between the intensity of anode cooling and the near-anode potential drop, the average current density, and the temperature of the anode surface.