Research And Implementation On The Key Problems Of Collector For High Power Gyrotron

With the rapid development of radio technology,an electronic system that oscillates or enlarge microwave signals under a vacuum environment,microwave vacuum devices,has also developed rapidly.Magnetrons,TWT,Gyrotron and various microwave electronic devices were invented one by one.In millimeter wave and sub-millimeter wave sources,Gyrotron vacuum devices occupy a pivotal position due to their superior performance,and play an important role in military and industrial applications.Based on electron optics,heat dissipation on the Gyrotron Collector and research group in the project,the working theory and design ideas of Gyrotron collector were introduced,and the Gyrotron is simulated by the electromagnetic simulation software CST STUDIO and Magic.In order to solve the local overheating problem,a defocusing system of depressed collector was designed,the outer structure of the collector was optimized.The main contents are as follows:1.Based on Maxwell's equations,the basic theories in electron optics such as the electrostatic field,static magnetic field in the Gyrotron,and the adiabatic compression theory in the electron gun are elaborated.At the same time,the research methods,transfer methods,and convection of heat transfer coefficient is introduced.The adiabatic compression theory and heat transfer theory laid the foundation for the design and simulation collector and thermal analysis in the next chapter,and provided a theoretical basis for the collection stage simulation in the next chapter.2.Elaborated the working principle of the depressed collector and the calculation formula,analyzed the difference of design principle between other collector.In order to meet the output requirements of the 170GHz high-power Gyrotron and solve the local overheating of the collector,the vertical field defocusing scanning system(VFSS)was first designed and the mutual average power density was calculated,then based on the vertical field scanning system the transverse field defocusing scanning system(TFSS)was calculated,and the average power density under the action of VFSS and TFSS was calculated.Finally,the range of the electron beam landing point on the collector electrode was 634mm,which was nearly 5 times larger than the original landing point range.The peak power density at the collection stage is 338.11W/cm~2,which meets the requirements of safe power density and greatly improves the power capacity of the collector.3.The CST STUDIO software was used to simulate the depressed collector to obtain analysis of Thermal Characteristics and analysis of Thermal Stress,the relationship between the number of fins,fin height,fin angle and the temperature distribution of the outer collector is analyzed,which provides a basis for optimizing the structure of the outer collector,and analyze the relationship between the thermal deformation and the temperature distribution.Improve the stability and service life of the collector.