Characteristics of an arc column in a hollow cathode arc

Abstract

The hollow cathode arc (HCA) was developed as a plasma source for low-pressure applications in the 1960s, since when it has been variously researched to clarify its underlying mechanism.^{1, 2} When arranged to incorporate a relatively high arc current, HCA can also be used as a welding heat source.^3–5 Through being a plasma source in low-pressure environments, HCA has further attracted attention as a welding heat source for use in space.^{6, 7} Through providing a degree of base metal fusion incommensurably greater than that obtainable with a conventional GTA (gas tungsten arc) heat source at atmospheric pressure, HCA is also regarded as being effective for industrial applications in low-pressure terrestrial environments.⁸