A novel low temperature plasma generator with alumina coated electrode for open air material processing

Based on our previous studies on a cold plasma torch which can generate homogenous and stable plasma under atmospheric pressure, we have developed a new plasma generator to give a lower gas temperature and wider processing area. Instead of the insulator-covered anode in the previous torch, an aluminum cathode with anodically oxidized alumina worked to generate a stable plasma in helium gas flow under atmospheric pressure by the application of rf (13.56 MHz) power between the cathode and a grounded conductive anode. The plasma exhibited light emission from high energy species as well as a very low gas temperature below 100 degrees C. Preliminary results of material processing by this plasma are also presented. (C) 1998 Elsevier Science S.A.