Study On The Atmospheric Pressure Low-power Surface Wave Plasma Jet

In comparison with the microwave plasmas yielded at lower gas pressure,the microwave plasmas produced at atmospheric gas pressure have some fine characteristics such as high density,high activity,simplified production setup,and so on.Therefore,atmospheric pressure microwave plasma received wide attention in the practical application and scientific research.However,due to the streamer style of microwave discharges often presented at atmospheric pressure and the need of very higher incident power for microwave discharges excited under that condition,thence it is difficult in realizing some special applications because of the expensive cost for microwave discharges at atmospheric gas pressure.Aiming at the scientific problem of realizing difficulty for atmospheric low-power microwave discharges,the study object is an atmospheric low-power surface-wave plasma(SWP)jet.The physical and chemical mechanism of the discharge of the atmospheric low-power SWP jet excited by microwave surface plasmon ploration(SPP)will be studied,by means of the resonant coupling discharges of the reciprocity between plasmas and microwave fields and the gas discharge triggered by local enhanced electrical field of SPP,in merit of realization easily.The discharge mechanism of SWP jet excited by SPP can be arrived at,through operating discharge experiment,diagnosing discharge process,and further assisting numerical simulation.When the project is completed,the spatio-temporal physical parameter evolution mechanism of the microwave streamer discharge will be understood and the ionization process of the atmospheric microwave SWP jet will be discovered.The main research contents on this paper are summarized as follows.1.Firstly,First of all,microwave discharge is a relatively new technology,and it requires scientific research workers with some microwave engineering and plasma engineering related knowledge.Therefore,we introduce some basic concepts of microwave discharge theory at first,and then study and discuss all kinds of existing plasma generation devices.Because the understanding of the advantages and problems of these existing plasma sources contributes to the development and design of new plasma sources,which is the starting point for writing this article.2.Secondly,due to the instability of microwave discharge,and the influencing factors of microwave discharge has not been studied yet.It is still to be studied how to develop a large-scale,energy-efficient and uniform microwave plasma under atmospheric pressure.Therefore,three types of coaxial resonators are designed in this paper,and microwave with a resonant frequency of 2.45 GHz is obtained.When the argon gas is passed through the resonator,in the case of only 5W microwave drive power,different morphology of the plasma jets are produced in the surrounding air,respectively.3.Finally,due to DC discharge and radio frequency discharge are different from the microwave discharge,its voltage and current can not be directly measured.In general,it is necessary to use a complex system to measure the forward and reflected power of the microwave discharge.Therefore,this is a huge obstacle to the diagnosis and analysis of microwave discharges.In this paper,the working mechanism of coaxial resonator is discussed based on the transmission line theory model.The electromagnetic model and fluid model are established by HFSS and COMSOL simulation software,and the discharge mechanism of coaxial resonator is further discussed.