Resonant Cavity Analysis And Simulation Of High Power Gyrotron Oscillator

The technology of terahertz has been used in medical, security, communications and other fields widely. Also, its unique advantages has reflected. A stable, efficient source of terahertz is the premise of application of terahertz technology. The gyrotron is the most practical and the most promising terahertz source, under the current level of technology. In this thesis, the gyrotron with working frequency is 340 GHz and working mode is TE10,2 mode is analyzed briefly, and a kind of resonant cavity used in the gyrotron is designed. The following parts are inclouded in this thesis.(1) According to the working mode of TE10,2 and the working frequency of 340 GHz we selected, a kind of resonant cavity is designed. Based on the study of the influence of structural parameters of resonant frequency and quality factor, the resonant cavity size is determined.(2) The linear theory of gyrotron is analyzed briefly. On the base of the analysis on the linear theory of gyrotron, some parameters of the resonant cavity, such as dispersion equation, coupling coefficient, starting current, are analyzed. The above study to prepare for the beam-wave interaction in the gyrotron.(3) The gyrotron nonlinear theory are analyzed briefly. On the base of the analysis on the nonlinear theory of gyrotron, some parameters like electron efficiency are analyzed by program language. After the determination of the resonant cavity structure, we changed the single working parameters of gyrotron and record its electronic efficiency on the electron efficiency. Finally, the range of each parameter which is required on a higher electronic efficiency is record.(4) Based on the principle of the electronic efficiency is maximized, the working parameters of the resonant cavity are analyzed. On the base of the range of the working parameters of higher electronic efficiency required, we combined parameters, then the electronic efficiency for each combination of parameters were compared. Finally, we chose a combination of working parameters, which has a higer electronic efficiency.Through the above analysis of the resonant cavity parameters, we can get the resonator frequency is 339.984 GHz, and the working mode is TE10,2 in the resonant cavity designed by this thesis. And the resonant cavity can get the higher electronic efficiency is 31.76% and the output power is 38.11 kW, with the working voltage is 60 kV, working current 2A, electronic transverse to longitudinal velocity ratio of 1.5.