The efficient plasma plume extraction from atmospheric pressure parallal dielectric barrier discharge jet

Summary form only given. Planar dielectric barrier discharges (DBDs) have a large number of industrial applications because of simple structure and no need for cumbersome impedance matching systems. However, planar DBD still have some disadvantages such as the limit of gap distance and the non-uniformity due to the characteristics of microdischarge intercepting electrodes. Therefore the DBD jet has been introduced. Other known atmospheric pressure plasma jet devices can generate very short plumes in the millimeter range. Recently Laroussi et al. developed a new plasma jet with long plume in the centimeter range. However, this type has difficulty in making large area plasma plume. Teschke et al. showed the possibility of long and large area plasma plume using coplanar DBD structure. Using coplanar DBD structure, we developed novel parallel DBD jet. The plasma source consisted of two coplanar DBD, which were made of two thin copper strips and alumina plate with 1 mm thickness. Each coplanar DBD was positioned as facing alumina plane with 1 mm gap. The helium was flowed into the gap with flow rate in the 10-40 l/min. A high voltage with frequency ranging from 1-30 kHz and amplitude up to 10 kV was supplied between two copper strips of each coplanar DBD. Experimental results showed the long and large plasma plume in the centimeter range. The length of the plume depended on the helium flow rate and the magnitude of the applied voltage