Potential control of floating metallic target in surface treatment of atmospheric pressure plasma jet

Controlling the potential on floating targets V_target is critical for plasma–surface interactions in atmospheric pressure plasma jets (APPJs). In this work, the interaction between an atmospheric-pressure helium plasma jet and a floating metallic target was investigated experimentally. The plasma jet is driven by a bipolar voltage pulse with adjustable duty ratio dr. The results show that the target potential increases from negative to positive with increase of the duty ratio. Potentials close to 0 V were obtained by adjusting dr under different peak-to-peak voltages. The bipolar pulse with an adjustable duty ratio is an effective method to control the potential on the target. The charging time and the discharge intensity of the plasma jet are important factors in controlling the target potential.