3D modelling of arc-cathode interaction

The aim of this work is to propose a model which can describe the plasma bulk and its interaction with the cathode using current density as input parameter. The pre-sheath is modelled through a two-temperature electrical conductivity estimation which takes into account the local state of the cathode layer. Thanks to this model, the current continuity resolution change following the plasma and material characteristics. Results obtained with our model are presented in a 2D configuration. More precisely we show that with our approach, the cathode sheath voltage drop profile at the cathode surface is non constant and we found that the ¿average¿ cathode sheath voltage drop is about 18V for a 200 Amps argon discharge with a cylindrical tungsten cathode.