Simulation And Analysis For 28 GHz Gyrotron

HPM technology is a subject rising in the late 1970s.Due to the continuous demand of scientific research and military for higher power,higher energy and higher frequency microwave sources,this subject has been rapidly developed and widely valued.At present,it is widely used in military,scientific research,industrial processing,new material preparation,medicine,biology and so on.Gyrotron,as a high-power millimeter wave source,is a device that can produce high-power microwave.It has incomparable advantages in wave length and high-power,and it can be used in millimeter wave radar,material processing,millimeter wave electronic countermeasures and plasma chemistry.Based on the development of gyrotron,this dissertation studies and designs the gyrotron with 28GHz gradual composite resonator.The details are as follows:1.According to the coupled wave theory,the fundamental and second harmonic gyrotron with TE_0,1-TE_0,2,2 working mode is designed,and the high frequency structure of the composite cavity with lock mode is designed.The influence of the structural parameters on the cavity frequency and Q value is studied respectively by using the software of the teaching and research office,finally,the high frequency structure design of the cold cavity is completed,and the influence of various structural parameters on high frequency system is analyzed and studied.2.According to linear theory,the starting current and dispersion equation of the gyrotron with 28GHz fundamental wave and second harmonic gradual composite resonator are analyzed,which lays the foundation for the design of the latter 28GHz fundamental wave and second harmonic gyrotron.3.Based on the nonlinear theory,the nonlinear numerical simulation of beam wave interaction in a 28GHz fundamental and second harmonic gradual composite resonator gyrotron is carried out.The effects of velocity ratio,guide center radius,working magnetic field,working current and working voltage on beam wave interaction efficiency are analyzed.4.According to the adiabatic compression theory,an electron gun suitable for28GHz second harmonic gyrotron is designed.The parameters that affect the electron beam velocity ratio and the velocity dispersion are analyzed.Finally,a 28GHz second harmonic gyrotron electron gun with good performance is obtained.The electron beam velocity ratio of the gun is 1.4,and the velocity ratio of the gun is 3.8%,which meets the requirements of 28GHz second harmonic gyrotron.