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A 100-kV/60-A high-voltage power supply (HVPS) based on pulse step modulation (PSM) technology has been established on J-TEXT Tokamak to feed the electron cyclotron resonance heating (ECRH) system for plasma heating. To fulfill the waveform monitoring, feedback regulation, and protection requirements, a high speed and precision voltage measurement and transmission system with high voltage and ground isolation is designed and applicated to the HVPS. A feedback regulation method is proposed to not only suppress the output voltage overshoot during startup of the HVPS operation but also ensure the precision of the output voltage on flat stage under the change of load conditions. Experiment results on the J-TEXT HVPS show that the voltage measurement system behaves well both in precision (measurement error $ ). The feedback regulation method can reduce the overshoot voltage to less than 1%.

In order to improve the characteristics of traditional atmospheric pressure plasma jet generator based on dielectric barrier discharge, a funnel tube four-electrode plasma jet generator that contains funnel quartz glass tube and four-ring electrode structure is designed in this paper. When the argon and carbon tetra fluoride mixed in a certain proportion is introduced into the narrow bore side of funnel tube as the operating gas and AC voltage is exerted, plasma jet flow will generate in the wide bore side and the spectrum test shows that there are a number of fluorine elements with strong activity in the jet flow. Firstly, the test results show that the contact angle of water on the surface of glass treated by jet flow can reach 137.5° while the SEM analysis indicates that the obvious micro Nano structure formed on the material surface can reach $68\mu\mathrm{m}$ in thickness. The Maxwell simulation analysis results of internal electric field structure of jet generator show that there are three uniformly-distributed and symmetrical strong electric fields inside the jet tube, which can enhance the ionization of operating gas and improve the stability of dielectric barrier discharge. Secondly, the results of calculating the changes of flow velocity and Re of operating gas inside the tube show that the operating gas flows more stable inside the tube and maintains in the laminar flow regime. Finally, the particle collision and ionization physical reaction process taking place in the three areas in the jet tube is analyzed and the reasons why there are more active particles in the jet flow and the processing effects are good are illustrated. The results indicate that there are relatively greater improvements of funnel tube four-electrode jet generator mentioned in this paper in discharge process stability, excitation degree of operating gas, surface processing effects and other aspects.