Influence of Mixed Cathode Emissivity on Generated Plasma Flow in Vacuum Arc with Heated Cathode

Vacuum arc is one of the most widespread sources of multicomponent ion/plasma flows. In the paper, we examine how the emissive properties of mixed cathode components affect the parameters of generated plasma. The scheme of vacuum arc with a heated cathode made of CeO₂ + Cr and TiO₂ + Cr powders was used. The arc discharges in the current range of 30–90 A and in the cathode temperature range of 1.8–2.0 kK were studied. It was found that CeO₂ provides an intensive thermal electron emission and the arc with CeO₂ + Cr cathode has a diffuse current attachment, plasma parameters are controllable and mainly Cr ions appear in plasma. Conversely, the current constricts in the arc with a non-emissive TiO₂ + Cr cathode, the plasma parameters are unchangeable and Ti and Cr ions are generated in comparable amounts. The results presented may be useful in multicomponent plasma sources design.