A vacuum arcs with refractory hot anode

We present a plasma model for a new mode of a hot anode vacuum arc configuration. The arc runs between a copper cathode and a hot graphite anode separated by a 1 cm gap. The cathode operates in the multi-cathode-spot regime, while the hot graphite anode back-evaporates the material flux arriving from the cathode. The interelectrode plasma expands radially from the gap. Plasma electron temperature, plasma density, anode drop potential and anode temperature are calculated by solving a system of equations for the anode heat flux and for the effective anode voltage. Good agreement is found between calculated and measured parameters. For example, according to both the calculations and measurements during steady-state arc operation the effective anode voltage is ~6 V