Numerical simulation of cathode-spot crater formation and deuterium desorption process on hydrogen titanium cathode with flux boundary conditions and different impregnation degree

Abstract

In this paper, the crater formation process of single cathode spot on hydrogen titanium electrode is modeled. In this model, combined with the deuterium diffusion equation, the flux boundary condition was considered to calculate the cathode spot desorption rate with different impregnation degree, and the deformation process of the cathode spot crater was simulated by a hydrodynamic model. The simulation results show that the current, size, and depth of a single cathode spot crater tend to decrease with increasing impregnation degree, which is consistent with many related experimental results. The simulation result shows that the desorption of deuterium in a single cathode spot crater mainly occurs in the ignition stage, and the positions of desorption are successively distributed in the liquid metal flow area on the side wall of the crater and the high temperature area in the center of the crater. The desorption rate of deuterium drops rapidly after cathode spot quenching. At the same time, the increase of arc current and impregnation degree can improve the deuterium desorption rate of a single cathode spot.