Influence of barrier material and surface roughness on atmospheric pressure uniform dielectric barrier discharge in air

Summary form only given. An atmospheric pressure uniform discharge has a great potential for improving surface treatment, efficiency of ozone generation, de-NOx and so on. So far, we have studied a stable generation of atmospheric pressure uniform discharge using dielectric barrier discharge device, and we already reported that by elevating barrier temperature or by using acrylic barrier material, the discharge mode changed from non-uniform to glow-like mode drastically. Recently, we have succeeded to generate an atmospheric pressure uniform discharge in air by use of alumina plate as barrier material. The uniform discharge was observed by photograph and was characterized by non-pulse current. However, why the stable uniform discharge generated by use of ceramics was not clear. Therefore, in this study we investigated alumina ceramics with various surface roughnesses and a different alumina containing other metal components. As the results, we found that (1) the surface roughness is not a decisive factor of the generation of uniform discharge, (2) but a mirror like smooth surface can not generate stable uniform discharge, (3) alumina containing other metal components cannot generate uniform discharge. In the presentation, we will introduce the discharge current waveforms and photographs of atmospheric pressure uniform discharge in air.