Droplet Erosion of a Cathode in a High-Current Vacuum Arc

Abstract

It is shown that high-current vacuum arcs accompanied by partial melting of the cathode surface and its droplet erosion can generate, in addition to the well-known droplets formed immediately in the cathode spot (first type droplets), a second component of erosion. The liquid part of the cathode surface can emit droplets with significantly different sizes and velocities, which may be called second type droplets. The mechanisms of the formation of first and second type droplets are also substantially different.