Analysis And Study On The High Frequency Cavity Of High Power Gyrotron

Millimeter and submillimeter wave have lots of advantages, such as,short wave length, wide frequency band, narrow beam,large capacity of communication,existing atmospheric window and so on. It is their unique properties, making it become one of the hot spot in the research of all scientists and scholars in recent years. However, the gyro-device based on the theory of relativity mass effect of electron cyclotron masers(ECRM) mechanism, can be to achieve high power output of the electromagnetic radiation, in millimeter wave and submillimeter even terahertz band which filled in the traditional laser and microwave devices in the millimeter wave and submillimeter wave band gap,and have incomparable unique advantages with other millimeter wave and submillimeter wave devices. This makes it has very important application prospects in thermonuclear fusion, millimeter wave communication, millimeter wave imaging radar, electromagnetic countermeasure, directed energy weapons, special material preparation and biomedicine, and become the research frontier and hotspot of domestic and foreign electronic devices.In promoting international nuclear fusion, high power, high frequency gyrotron is currently the most rapid development, the most mature, most results obtained gyrotron the gyrotron family. High frequency structure of gyrotron is an important place for electron beam and electromagnetic wave energy exchange, and decides the performance of gyrotron and interaction efficiency. This paper analyzes and researchs the structure high frequency of gyrotron, based on the linear theory and self consistent nonlinear theory of gyrotron. The main content of this thesis are as follows.1. Research and analysis of the electron cyclotron maser mechanism, and according to the self consistent nonlinear theory, derivating the passive and active multimode first-order transmission line equation. We have written the numerical calculation program of the design of cold cavity and the numerical simulation program of thermal cavity. Using self-compiled program and commercial electromagnetic simulation software for numerical calculation of the high frequency structure reported in literature. Comparing the calculated results to verify the program.2. Using the cold cavity numerical calculation program design the three-step high-frequency structure of the gyrotron whose working frequency is 170 GHz. Then,using the software analysis the influence which the size parameters of the cavity of each part cause on high frequency characteristics, in order to optimize the structure of high frequency.3. Writing the numerical calculation programs of the gyrotron high-frequency structure dispersion equation, coupling coefficient and starting current. With the help of the numerical calculation programs, analyzing the dispersion equation, the cavity coupling coefficient and starting current, which provide initial values and for the numerical simulation of thermal cavity.4. Using of the numerical simulation program of hot cavity to simulate the high frequency structure designed. In the process of simulation, analyzing the change of the efficiency of the interaction effects, when the operating conditions,such as,the magnetic field intensity, the electronic transverse, longitudinal velocity ratio, guiding center radius, voltage,current and so on,change severally. In the end, the best working conditions where the interaction efficiency achieve maximum are get.