一种基于同轴结构的低功率微波大气压等离子体射流装置OA

The coaxial microwave plasma jet device features compact structure and convenient operation.The plasma generated in the atmospheric pressure environment has broad application prospects due to its advantages of high ionization degree and high particle activity.To reduce the excitation power threshold and enhance the regula-tion flexibility of the device,a low-power microwave atmospheric pressure plasma jet device operating at 2.45 GHz is designed based on the coaxial structure with extended outer conductor.The influence of outer conductor exten-sion on the excitation power threshold of plasma is analyzed,and the variation law of plasma morphology under different discharge parameters is explored.Simulation results show that the maximum electric field intensity at the tip of the inner conductor is increased by at least 50%after outer conductor extension compared with the structure where inner and outer conductors are flush,thereby reducing the plasma excitation power threshold.Experimental results indicate that when the extension length of the outer conductor l=8 mm,the minimum excitation power of argon plasma can be as low as 5 W.When l=15 mm,only 170 W input power is required to excite atmospheric pressure air plasma.The performance of the device is superior to those of the coaxial structure with flush inner and outer conductors.