Study Of Portable Plasma Jet Generated By DC Self-excited Pulse Discharges

Atmospheric pressure plasma jet technology as a new type of gas discharge, has developed rapidly in recent years, has become an important research direction in the field of plasma science and technology. Researchers using airflow, electric field and the unique design of experiment to produce plasma transport outside of the electrode of open environment, so as to realize the separation of the discharge area and work area, at the same time, rapid flow of plasma can put a lot of active species as well as a variety of charged particle transport to the surfaces to be processed, which is to achieve a good contact with plasma and processing objects, and because of the low temperature plasma gas temperature is low, and active particle characteristics of variety, no pollution, so no matter in traditional industrial fields, or in the emerging field of biomedical, atmospheric pressure plasma jet will be a good application prospect.In order to obtain a stable low-temperature plasma jet at atmospheric pressure conditions, and its application to the biomedical, this paper developed a low temperature plasma jet experiment device, its shape is similar to "gun" type, while developed a kind of high voltage dc power supply, which based on the principle of piezoelectric ceramic transformer, the total weight of the entire unit, including the high voltage dc power and jet device is less than the total weight of500g.Experimental results show that when the piezoelectric ceramic transformer input12v dc voltage, due to the high boost of the piezoelectric ceramic transformer, the output will be700v to1500v high-frequency sine wave alternating current (ac), the output through ten times rectifier circuit can output DC7kV to DC12kV high-voltage.At the same time, its successful application in the argon plasma under atmospheric pressure experiment, it was found that the positive electrode in argon gas space can produce stable low temperature plasma jet, forming a single electrode discharge, and the â… -â…¤ test results show that the performance of gas discharge current is periodic pulse type, showing self-excitation type, and the discharge pulse repetition frequency is about tens of kilohertz and discharge pulse repetition frequency, the peak maximum discharge current is about30mA, a single pulse width of about several hundred nanoseconds, the maximum length of the plasma is about3cm.Further research shows that the plasma jet current pulse frequency is determined as a result of the ion drift mechanism. Using the simulation software to estimate the resistance of plasma, at the same time using COMSOL software is analyzed in detail the characteristics of particles in the argon plasma jet.