Research And Design Of ECRH Transition Waveguide For EAST

The electron cyclotron resonance heating system is one of auxiliary wave heating systems of the EAST facility.The work of the system requires the safe and stable operation of the microwave transmission line.The corrugated circular waveguide in the microwave transmission line is used to transmit the millimeter wave power,which is generated by the source and delivered to the antenna.According to the technical requirements of the microwave transmission line of the electron cyclotron resonance heating system,the research and design of the millimeter wave transition waveguide used in the transmission line to match the transmission characteristics are carried out.Firstly,this dissertation introduces the composition and function of the electron cyclotron resonance heating system,and expounds the research background and significance of the subject.Secondly,the dissertation makes a detailed design around the millimeter wave transition waveguide used in the transmission line.The main content includes three parts:(1)Microwave performance analysis.Taking the inner diameter gradual change and low mode conversion loss as main objectives,the coupled wave equation method based on mode coupling theory is selected as the analysis method,and the microwave performance of the transition waveguide is analyzed with numerical solution code.We get a transition waveguide with small mode conversion loss,tiny ohmic loss and wide bandwidth.(2)Thermal analysis.Taking waveguide work safety as the main objective,the temperature rise,deformation and thermal stress of the transition waveguide is analyzed,which is realized with the theoretical basis of thermodynamic analysis and related software.The appropriate cooling conditions and parameters are obtained.(3)Mechanical structure design.The related software is used to design the specific structure of the transition waveguide,and the waveguide materials are analyzed and selected.A waveguide scheme with a simpler structure is designed,and the processing parts and assembly drawings are completed.At the end of the thesis,a TE11-HE11 mode converter with a mode conversion efficiency of 95.59%is designed for the low power test requirements of the transition waveguide.The analysis method is the coupled wave equation method based on the mode coupling theory.The performance of the mode converter working in the millimeter wave band is analyzed and optimized with numerical solution code,and the structure design of the mode converter is realized.The work of this thesis provides a theoretical basis for the further research of high power millimeter wave components.