Refractory electrode region recovery following arc interruption

Measurements are presented of the voltage fall across the electrode region of low-current carbon arcs when test current pulses are injected through the arc gap at some time (less than 100 µs) following rapid removal of the arc current. The results thus shed some light upon the thermal reignition phenomena of refractory electrodes. A model is proposed to describe the observed behavior at low injection current levels. This model may also be of assistance in describing the behavior of hot probes in high-pressure plasmas. Although the model is not extended to high current levels, a discussion is presented of the electrode region behavior for currents at which mechanisms apparently form, which are necessary for reignition and steady-state conduction through the electrode regions.