Phenomena of the Arc Electrode contacting with the Plasma Column

This report described the electrical and mechanical characteristics of the face-face electrode arc, which was supplied with Argon plasma stream, and macroscopic behavior of the electrode spot and boundary layer of that are by means of high speed photography. The face-face electrode was consist of copper anode and thoriated tungusten cathode or tungusten anode and thoriated tungusten cathode. The arc voltage-current characteristics was always dropping characteristics for tungusten anode. But using the copper anode, it changed from rising characteristics to dropping or flat characteristics with increasing of the arc current, and arc voltage rising ratio, in the region of rising characteristics, became large as the radial distance (R_a) of anode from nozzle axis was increased. Using tungusten anode, anode spot of which temperature was 3,700&acd