Effect of Temperature Distribution on the Calculation of the Thermal Current in the Mathematical Model of Pulsed Heating of a Tungsten

In this paper current distribution model in the tungsten sample and vapor at surface under electron beam heat was considered. The model is based on the solutions of electrodynamic equations and the two-phase Stefan problem in cylindrical coordinates. The two-phase Stefan problem defines the temperature inside a sample area taking into account the evaporation at its surface. A model temperature distribution in a thin layer of evaporated tungsten is used, which repeats the surface temperature. The electrodynamic equation include received temperature values and solved over the whole region. The case of constant values of electrical resistance and thermoemf in gases and metals is considered. The temperature calculations were made considering constant coefficients and temperature dependencies of specific heat capacity, density and thermal conductivity. It is shown that the detail of the coefficients of the Stefan problem has a great influence on the results of solving the electrodynamics equation. The model parameters are taken from the experiments on the Beam of Electrons for materials Test Applications (BETA) stand, created at the BINP SB RAS.