Advanced Modeling of Plasma-Cathode Interaction in Vacuum and Low-Pressure Arcs

A detailed model has been developed for modeling of arc plasma-cathode interaction, which takes into account a pre-existing plasma cloud, the interaction of the metal vapor plasma produced in the spot with the cathode, Joule heat generation in the cathode body, and relevant hydrodynamic phenomena, including surface deformation and droplet ejection. The model provides a complete description of all phases of life of an individual spot. Results of investigation of spots on copper cathodes in high-current vacuum arcs, and of current transfer to tungsten tiles of plasma-facing components in fusion devices are reported.