TIME-RESOLVED DIAGNOSTIC OF ATMOSPHERIC PRESSURE PLASMA JET WITH DOUBLE-RING ELECTRODE

Atmospheric pressure plasma jet (APPJ) has played a significant role in various fields. Among various devices, the APPJ with the double-ring electrode is outstanding. It has the advantages of a simple structure, stable discharge, high flexibility, longer jet length, and lower temperature. This work utilizes ICCD camera acquisition technology to perform nanosecond level time-resolved diagnostic on the APPJ with double-ring electrode, which driven by a high-frequency and high-voltage AC power supply. The results showed that there are two distinct discharge stages in one discharge cycle, which are located near the positive and negative half-cycle peaks of the applied voltage. During the positive half-cycle discharge stage, the plasma brightness, length, and discharge development speed are significantly stronger than in the negative half-cycle. It is worth noting that only in the negative half-cycle discharge stage, the phenomenon of plasma propagating forward independently from the nozzle can be observed. This work has a positive promotion effect on understanding the dynamic processes of plasma, revealing the behavioral law of plasma, optimizing plasma equipment, and many other aspects.