Research On Continuous Frequency Tunable Coaxial Gyrotron

Terahertz research is currently one of the hot spots at home and abroad. Gyrotronis a terahertz source based on vacuum electronics technology. Compared with thetraditional vacuum devices, the gyrotron can achieve high power and high efficiencyoutput in terahertz region. As one of the high-power radiating sources in terahertzregion, the output power of gyrotron is up to several tens of kilowatts. One of the mostpromising development direction of gyrotron is as terahertz source. The traditionalterahertz gyrotron is difficult to meet the needs of nuclear magnetic resonance using thedynamic nuclear polarization technique, for working in a fixed frequency.In this dissertation the continuous frequency tunable0.42THz coaxial gyrotronwith2GHz bandwidth by mechanical tuning has been studied：1、An introduction to the basic principles and research status of adjustablefrequency gyrotron is presented.2. Analysis of continuous frequency tunable THz coaxial gyrotron cavity is carriedin this paper. The longitudinal field equations were solved by the fourth-orderRunge-Kutta method and the shooting method. The calculated results show that theresonant frequency change linearly with the movement of the inner conductor, and thequality factor is high in the whole bandwidth.3. Mode competition analysis of the gyrotron is carried by using the linear theoryof the gyrotron. The gyrotron can work at a single mode by choosing a suitable electronbeam guiding, operating magnetic field, voltage and the start-up current.4. The time domain self-consistent nonlinear theory of gyrotron is derived and theelectron-wave interaction equations is solved by the Runge-Kutta method and the finitedifference time domain method. The electron-wave simulation is carried by the gyrotronsimulation platform which was built by the MATLAB software. The results show thatthe output power can keep over8kilowatts level in the tuning bandwidth withunchanged operating magnetic field.