Current conduction through hot insulation walls in MHD channels

Abstract

The temperature distribution inside an insulating wall fixed between the adjacent electrodes in an MHD channel has been estimated across the direction of flow of plasma inside the channel. It has been shown that sharp gradients exist within a small thickness of the insulating wall adjacent to its innermost layers facing the plasma inside the channel. Most of the electric current conduction takes place through these layers. As a result of it, thermoelectric breakdown is found to occur at much lower potentials for the walls made of Al2O3 and MgO.