MAXWELLS CONSTRUCTION FOR NONLINEAR HEAT STRUCTURES AND DETERMINATIONOF RADIUS OF ARC SPOTS ON CATHODES

The temperature distribution in a half-space (the cathode bulk) heated by an energy flux coming from the adjacent media (plasma) is consider ed for the case when the dependence of the energy flux density on the local surface temperature is localized in a narrow temperature range. A condition is derived of co-existence of a region that collects the e nergy flux with a surrounding energy dux-free region (Maxwell's constr uction). This condition allows one to calculate the radii of current s pots on are cathodes.