Mode Analysis Of The Electron Cyclotron Wave Based On Phase Retrieval

In fusion research,the auxiliary heating and current drive systems have become important for various magnetic confinement fusion devices.Due to the quite localized heating profile,simple coupling principle,and the launcher away from the plasma,the electron cyclotron resonance heating（ECRH）system has been widely used in various physic experiments.The mode purity of electron cyclotron（EC）wave is a key parameter for safe and stable system operation,and it will also influence the plasma heating and current drive efficiency.In addition,the wave mode information can provide important references for the transmission lines alignment and the matching optical unit（MOU）design,etc.According to these requirements,the research mainly focuses on the EC wave free space radiation,the phase reconstruction based on EC wave amplitude and the mode analysis.Based on these theoretical researches,the EC wave intensity measurement technique is researched,and the experimental platform is designed and established.Finally,it was tested on a 68GHz ECRH system and the detail calculation results provide the EC wave mode information of MOU.The thesis mainly includes the following four parts:The first part briefly introduces the close relationship between the auxiliary heating ECRH system and the tokamak device,then,analyzes the importance of the EC wave mode purity.Some existing EC wave mode analysis methods are also given.The second part describes the wave radiation theory in free space,the phase reconstruction theory based on wave amplitude and the mode analysis theory.The iterative process and the convergence of the iterative algorithm are deduced in detail.Programs of the wave field profile calculation,the phase reconstruction and the mode analysis are designed.They provide basis for mode analysis of EC wave in ECRH system.In addition,the TEM₀₀mode and linear polarization mode are used to verify the validity of these programs.The third part mainly focuses on the design of intensity measurement system for EC wave,including the material and size of the target,the parameters of the infrared camera,also its adjustable spatial height and angle.Finally,considering the reliability of measurement and the safety of equipment,the design results are given.The fourth part gives the MOU experiment of measuring the EC wave intensity on a68GHz ECRH system,also analyzes the experimental data in detail,including coordinate transformation,data filtering and EC wave behavior,etc.Then,based on the designed programs,the phase reconstruction and mode analysis are finished.