Measurement Of Electromagnetic Parameters Of High Power Vacuum Window

The high-power gyrotron occupies an important position in thermonuclear fusion,and the output window is the key structure.Its quality directly affects the mode purity,output power and stability of the high-power gyrotron.The measurement of the characteristics of the material of the output window is important and necessary.At the beginning of this article,a systematic analysis of the commonly used methods for measuring dielectric parameters of materials is carried out,combined with the special application scenarios of the output window material,their measurement accuracy,and operability,and finally the quasi-optical cavity measurement method is determined.Combined with the analysis method of the quasi-optical cavity,a detailed theoretical analysis was performed,and the distribution of equiphase surface,electric field and energy in the cavity was simulated and nanlyzed with the mathematical tool MATLAB software.Based on the theoretical knowledge of optical,the article aligns the basic parameters of the optical resonator with detailed theoretical analysis and formula derivation.Secondly,the article conducted a detailed theoretical analysis of the main losses in the optical resonator and the factors affecting the losses,and simulated the relevant curves for discussion.At the same time,the coupling method of the quasi-optical resonator is introduced.The basic parameters are used to design and use 3D drawing software SolidWorks to draw engineering drawings and processing on its reflection spherical mirror and the fixture used in the mechanical fixing method in the actual process.Finally,the testing method of the quasi-optical cavity system is analyzed,and the quasi-optical cavity testing system is established based on the vector network analyzer,and the measurement of the characteristic parameters of domestic diamond and beryllium oxide at room temperature is completed;and simulation of the high power and high temperature in the environment,the PNB pyrolytic boron nitride is heated and tested at different temperature points to test the relevant electromagnetic parameters.