Numerical simulation of the plasma parameters of a low-pressure arc discharge in helium

A global integral model of an arc discharge in a helium medium with a sputtered graphite anode is presented. The main feature of the model is the simultaneous consideration of the plasma of the discharge gap, the cathode and anode layers, the current transfer, the thermal regime of the electrodes, and the evaporation of the anode. Both the calculated and experimental results show that the discharge voltage linearly increases with the inter-electrode distance, as in a classical positive column where the voltage drop is proportional to its length with a constant electric field. The calculated data also show a good agreement with the experimental and calculated data of other authors, in particular, a good correspondence between the absolute values of electron density and temperature, the discharge voltage and the anode ablation rate as a function of the discharge current.