Numerical Simulation of Cathode Jet Distribution Contributing to Movement of Cathode Spot in Vacuum ARC

Vacuum arc has been applied for valuable technology such as surface treatment of oxide layer 1 and arc ion plating (AIP). Although it has been required to elucidate the movement factor of cathode spots in vacuum arc, it is unclear because of the complexity of physics of cathode spot and difficulty of experimental elucidation. Intense cathode jet is produced at cathode spot because of evaporation from cathode spot caused by joule heating, emitted metal vapor is ionized. The behavior of these ions is considered to be a movement factor of cathode spot; however, the details have not been clarified. Therefore, numerical simulation of cathode jet distribution contributing to movement of cathode jet in vacuum arc was investigated in this research. In this research, three-dimensional electromagnetic thermal fluid simulation was developed 2 3 . Two-temperature between electron and heavy particle were considered in order to simulate plasma in vacuum arc 4 . The particle composition of thermal plasma near cathode was calculated by Saha’s equation. As a result, flow of neutral particles and ions from cathode jet contributing to movement of cathode spot is calculated, electromagnetic force and pressure gradient force acting on cathode jet was analyzed.