The erosion of copper cathodes from vacuum to atmospheric‐pressure arcs

摘要

The erosion rates of cathodes of copper for arcing conditions ranging from vacuum to atmospheric pressure are examined in the light of very recent scanning‐electron‐microscope studies made by the authors. These have revealed details of cathode crater sizes and distributions, surface densities, and the numbers produced per second. These results explain the ways in which erosion rates vary with such parameters as arc current, arc duration, and gas pressure. Static arcs as well as arcs having cathode roots moved magnetically are considered.