Design and Simulation of Electron Optics System for 1.0 THz Backward-wave Oscillator

In this paper, the electron optics system of 1.0 THz backward-wave oscillator is designed, and the design process of electron gun and permanent magnetic focusing system are described. Firstly, the design and debugging of the electron gun is carried out according to the initial design value, and the electron gun with the beam range and beam radius meets the requirements. Secondly, through theoretical calculation, it is known that the uniform region magnetic field is 12000 Gauss, and the uniform magnetic field that meets the focus is designed. The simulation results show that the EOS has good laminarity, the passing rate of electron beam is 100 ^% , and the filling ratio is about 70% under the voltage of 25kV and the beam current of 20mA.