Experimental Study of Atmospheric Pressure Plasma Jet with Needle-ring Electrodes

Atmospheric pressure plasma jet technology has very promising application prospects and is widely used in medical, wastewater treatment, surface modification, and other fields. In this paper, a needle-ring discharge structure is used to generate argon plasma jets under an atmospheric pressure environment. The effects of the variation of parameters such as needle-ring electrode gap, quartz tube diameter, and gas flow rate on the starting discharge voltage and plasma jet length of the system are studied by quantitative and comparative analyses. The results show that increasing the voltage between the two electrodes will increase the jet length, but up to a certain level, the jet length will not be increased. As the argon flow rate gradually increases, the required starting discharge voltage and jet length will also increase. However, when the gas volume flow rate increases to a certain level, the generated plasma jet will deviate from the central axis of the quartz tube. The above results are interpreted qualitatively and are considered to be of great importance for the application of atmospheric pressure plasma jets.