NONLINEAR HEAT STRUCTURES AND ARC-DISCHARGE ELECTRODE SPOTS

Domainlike temperature distributions (solitary structures) are studied, which may arise in the half space with the surface heated by the external heat flux depending in a nonlinear way on the local surface temperature. Solutions describing stationary axisymmetric structures for some model dependencies of the external heat flux density on the surface temperature are found analytically or numerically. The stability of stationary axisymmetric structures is analyzed. When applied to an analysis of spots on electrodes in arc discharges, for given characteristics of the near-electrode plasma layer such an approach results in the complete description of the stationary spots on smooth surfaces, including the spot radius and the integral current. An evaluation for cathode spots in vacuum arcs is given; the results are inside the usual range of characteristics of macrospots.