Electric arcs: their electrode processes and engineering applications

The paper reviews some of the most significant developments made since 1970 in the understanding, observation and control of the phenomena which occur in the cathode and anode regions of arcs under a number of conditions, and in the engineering applications in which they are used or arise. Even with this limitation to less than 14 years, the literature on arcs is so vast that selectivity has been necessary. Those aspects which have been chosen here for a review of the work, which has been done by many investigators attempting to obtain a more complete understanding of the processes involved, are nonrefractory cathodes at gas pressures near atmospheric, anodes near atmospheric pressure, vacuum arcs, unipolar arcs and hollow-cathode arcs. The sections on each of these aspects are followed by the main body of the paper in which a large number of engineering applications are discussed, in which arcs are used as part of the process, or where they occur and must be controlled and suppressed.