Effect of the parallel circuit parameters on the instability of a low current vacuum arc

In order to clarify the instability phenomena of a low current vacuum arc, the authors observed the phenomena by changing the parallel circuit parameters. They measured instability initiation current, chopping current, arc voltage, arc voltage oscillation peak and the transient recovery voltage by using copper, copper chromium and silver tungsten carbide electrodes. It was found that the chopping current, the arc voltage oscillation peak and the transient recovery voltage are dependent on the parallel circuit parameters, but the instability initiation current and arc voltage is not dependent on them. They also found that the instability phenomena depend first of all on the cathode material.