Analysis of the Thermal Conductivity Mechanism Affecting on the Plasma Parameters in Instability Low Current Vacuum Arc

This analysis used the cathode spot model to describe the physical mechanism of the thermal conductivity effect on the instability phenomena. An analysis of stable arc current is performed by changing the thermal conductivity of copper by compound material. The minimum stability arc was found to be inversely proportional to the thermal conductivity. Low thermal conductivity is more critical in a more stable arc than a high thermal conductivity cathode material. The thermal conductivity is reduced to increase stable arc current by reducing reversed electrons from the plasma region. These results were similar to the obtained data, indicating that this analysis by the cathode spot model, which is used to investigate the thermal conductivity effect in low-current vacuum arc, may be valid for volatile materials.