470 / 2017-05-08 15:05:15

Modeling of Cathode Spot Crater in Vacuum Arc

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A two-dimensional (2D) rotary axisymmetric model has been developed to describe the formation and development of cathode spot in vacuum arc. The model includes hydrodynamic equations and thermal conductivity equation. Parameters used in this model come from experiments and other researchers’ work. The simulation results show that when the energy flux density is 1.5~3×1012W, discharge current is 1~6A and the pressure is 1~3×108Pa, the crater radius is 1.4~4.1μm, the crater depth is 1.4~2.1μm, the velocity of liquid metal is 154~428m/s and the maximum temperature is 2145~5342K which is located in the area with radius 0.5~1.5μm. Besides, on the chromium cathode, the maximum temperature is higher mainly because of the lower thermal conductivity.