Dynamic Temperature Characteristics of Cathode Microprotrusion Under Electron Emission Based on Smoothed Particle Hydrodynamics

The study of dynamic temperature characteristics of cathode microprotrusion under electron emission would be essential to the development of high-voltage vacuum systems. Owing to the multiscale and multiphysics characteristics of the microprotrusions under the electron emission, smoothed particle hydrodynamics (SPH) method has become one of the feasible methods. In this article, the SPH method is introduced to study the dynamic temperature characteristics of a micrometer scale microprotrusion under the electron emission. First, the constitutive model and the equation of state with the material strength and the coupling effect of the heat conduction, Joule heating, Nottingham effect, and electron emission have been introduced into the SPH method. Then, an SPH model of the microprotrusion under the electron emission with considering the temperature correction is established by combining the SPH method and thermal-field emission heating model. Compared with the finite element method (FEM) and theoretical calculation, the SPH model of the microprotrusion under the electron emission is verified. Based on the SPH model of the microprotrusion, the dynamic temperature characteristics under the different conditions are quantitatively obtained and analyzed. The results of this article may provide some useful references for the vacuum insulation design and the insulation state evaluation of the high-voltage vacuum system.