Roundabout Oscillating Tube Studies

In recent years, the international academic research on THz source has gradually been warming up. Due to THz band which is between millimeter-wave and infrared band, THz radiation generated considerable difficulties. THz source has important applications in THz radar, long-range detection, medical and laboratory .Because of the need for more than MW THz radiation source, THz radiation source is the focus of the study. Gyrotron is a kind of promising THz radiation source. The purpose of this article gets some useful attempts to realize the use of gyrotron in THz.In the first part of this article I provided an overview of the extensive application of THz technology, the development direction and the development of the situation, and then give a brief introduction on the basic principles of Gyrotron .In the second part, I analyzed and studied the linear theory of gyrotron .By calculating and comparing beam-wave coupling, mode competition and start-up current, mode selection of the pre-designed 240GHz and 450GHz gyrotron oscillator carried out.In the third part, I analyzed the self-consistent nonlinear theory to study the simplification of electronic equation of motion and incentives equation, using Gaussian distribution to approximate field divisions. The non-self-consistent non-linear and non-linear self-consistent theory has been developed along with a MATLAB program. First of all, I optimize the magnetic field and the efficiency of the electronic parameters by using non-self-consistent program; complete the preliminary design of high-frequency structure of 240GHz and 450GHz gyrotron oscillator. On the basis of the self-consistent program, I completed the optimization of the cavity design and calculated output power and efficiency of the cavity.In the fourth part of the article, according to last two chapters, I studied the selection of modes, analysis of mode competition, cavity structure and electrical parameters. Obtaining the necessary parameters of particle simulation, I simulated 240GHz and 450GHz gyrotron by using particle simulation software(MAGIC), and compared the results of particle simulation and the calculation results of MATLAB program.