The Increase of the Jet Size of an Atmospheric-Pressure Plasma Jet by Ambient Air Control

We present an approach to increase the area for surface treatment using a nitrogen atmospheric-pressure plasma jet sustained by a pulsed dc power source. This plasma is used for glass surface treatment to quantify the efficiency of the treatment by examination of the water contact angle before and after the treatment. The proposed approach utilizes a glass tube to shield the jet downstream from the ambient air contamination. With this approach, the visible jet length and width increase significantly. The effective area for surface treatment using this jet increases by more than a factor of two.