Study on multi-constricted arc plasma

Summary form only given, as follows. Arc plasma with higher core temperature and energy density is desirable for welding and cutting technology. Finding good methods to raise the core temperature and energy density of arc plasma is one of the many key problems confronting plasma researchers in this field. In this study, an auxiliary nozzle is added to ordinary plasma torch. The original plasma torch is a commercial micro-plasma torch. Its constriction tunnel is 0.8 mm in diameter and 2.0 mm in length. At the outlet of the micro-plasma torch, another constriction nozzle is added. The diameter of the additional constriction tunnel could be larger or smaller than the original nozzle. The added nozzle length versus diameter ratio is fixed at 1.5 in this experiment. Argon is used as plasma gas. A CCD camera with a resolution of 2160/spl times/1440 is used to capture the images of arc plasma. Inverse Abel transform is conducted on those images to get the 3-D temperature distribution of the arc plasma. This study shows that using multi-constricted nozzles is a novel way of improving the quality of arc plasma.