Design Of High Power Quasi Optical Mode Converter

In recent years, with advances in Intense relativistic electron technology, High Power Microwave(HPM) research is well developed, the output power and energy has been greatly improved. For the high power gyrotron worked in higher-order modes, the traditional mode converter has been difficult to meet the requirements. Therefore, it is necessary to research the quasi-optical mode converter, which can build in gyrotron.In foreign countries, the related research in quasi optical mode converter start early, relevant theoretical research is very deep, but it is just beginning in our country. This paper has made a detailed analysis on the theory of Quasi-Optical mode converter, and contrast the radiation characteristics of different radiator. And then the paper analysis focusing mirror system, phase correction theory, and mirror smoothing.Analysis on the radiator used geometric optics principles and mode coupling theory. Based on these theories, a numerical software has written. Using this software to calculate the wall current distribution of TE10,4 mode Denisov launcher, and wall current distribution of the mirror system from FEKO simulation agree well with numerical calculation results.After theoretical analysis, a 220 GHz TE0,3 mode Vlasov Quasi-Optical mode converter and a 140 GHz TE10,4 mode Denisov Quasi-Optical mode converter were designed. The numerical results also agree with FEKO simulation results. In the process of numerical calculation and simulation analysis, the result shows that the Katsenelenbaum Semenov Algorithm(KSA) can significantly improve the content of Gaussian beam. However, after phase correction, when we smooth the mirror, the mirror structure is not perfect, there are many problems to solve. The main contents of this actical include:1. Give a brief introduction to the development of high power microwave technology and quasi-optical mode converter applications of high power gyrotron.2. By using the geometrical optics theory and the mode coupling theory to analyze the principle of Vlasov launcher and Denisov launcher, and their radiation characteristics.3. Based on geometric optics theory, deduced the structure of quasi-elliptic equations mirror, and introduced the theory of KSA algorithm.4. Designed a Vlasov Quasi-optical mode conversion system and a Denisov Quasi-optical mode conversion system, at the same time, the numerical results and the simulation results were compared, result show that they agree well with...