Calculation of Thermal Currents in a Tungsten Plate and in a Thin Layer of Tungsten Vapor during Pulse Heating with Allowance for Temperature- and Phase-Dependent Electrical Resistance and Thermo EMF

In this paper, we consider a model of current distribution in a tungsten specimen and the evaporated substance when the surface is heated by an electron beam. The model is based on solving the equations of electrodynamics and the two-phase Stefan problem for calculating the specimen area temperature in a cylindrical coordinate system. We use a model temperature distribution in a thin layer of evaporated tungsten that replicates the surface temperature. Thermal currents are obtained using approximate temperature dependences of the electrical resistance and thermo emf of tungsten and its vapor. The model parameters are taken from experiments at the Beam of Electrons for materials Test Applications (BETA) stand, created at the Budker Institute of Nuclear Physics of the Siberian Branch of the Russian Academy of Sciences.