The Formation of Atmospheric Pressure Air Low Temperature Plasma Jet.

Under the condition of DC discharge, a method to form a low-temperature plasma jet in atmospheric pressure air is proposed. By analyzing the electric field distribution characteristics and discharge phenomenon of the aluminum foil needle electrode, it is found that the existence of the upper hemispherical aluminum foil can increase the electric field at the tip of the needle electrode, thereby increasing the difference of the electric field strength between the needle electrode tip and the lateral side of the needle electrode. Under the action of the gas flow, the discharge phenomenon generated by the double-needle electrode forms a tip arc that distorts the electric field in the front space, thereby forming a plasma jet extending axially forward in the outer space of the gas nozzle. By further optimizing the structure of the double-needle electrode, it is found that the plasma jet can form the spatial electric field with transitive change in the formation process of the plasma jet, which can form a plasma jet that exceeds the right ground electrode. The self-pulse discharge formed by the inter-electrode arc can provide more seed electrons during the formation of the plasma jet. Finally, a longer, higher density atmospheric pressure air low temperature plasma jet is formed without airflow. [ABSTRACT FROM AUTHOR]