Surface potential measurement of two kinds of alumina barriers which generate different barrier discharge modes

Summary form only given. The Dielectric Barrier Discharge (DBD) is composed of many filamentary discharges, and it can be applied to ozone generation, surface treatment and so on. However, in case of surface treatment of thin polymer film, pinholes or nonuniform surface modification may sometimes appear. Therefore, many researchers have investigated various methods to generate the homogeneous DBD at atmospheric pressure. In 2009, we succeeded in generating homogeneous DBD in air, N₂ and O₂ using alumina barriers (Purity of Al₂O₃: 92%, Type: A473, Suppler: Kyocera Corporation). This discharge is recognized as an Atmospheric Pressure Townsend Discharge (APTD). However, when we used different alumina barrier (Purity of Al₂O₃: 92%, Type: A440, Suppler: Kyocera Corporation), the APTD in air could not be generated even if we changed the applied voltage and frequency. We are now thinking that electrons attachment, detachment and secondary electron emission from barrier are very important for the stable generation of APTD. In order to find some evidence of the difference of electron attachment effect of two kinds of alumina, we measured a surface potential at 1.0 mm above the barrier after negative corona discharge of 30 seconds.