Study on formation mechanism of atmospheric pressure glow discharge air plasma jet

Based on the results of needle electrode discharge experiments and electric field simulations, this study proposes a tip extensional ionization theory for explaining the formation mechanism of atmospheric pressure glow discharge (APGD) plasma jets. Under the condition of DC power supply, atmospheric pressure glow discharge (APGD) air plasma jets are realized without airflow. It is found that the necessary initial electrons for discharge are derived from free electrons in space, residual electrons, or runaway electrons, and the difference of the electric field intensity between the needle electrode tip and the lateral side of the needle electrode is an essential condition for the formation of the plasma jet. It is further discovered that a space electric field with transitive change is generated in the formation process of the plasma jet, and therefore a phenomenon occurs: the plasma jet generated from the high voltage electrode exceeds the lateral ground potential electrode. This study provides a theoretical basis for the analysis of the formation mechanism of plasma jet under various discharge conditions and promotes further research such as on the formation process of the lightning leader and lightning protection. Published by AIP Publishing.