Design and Simulation of Electron Optics System for 340 GHz Extended Interaction Klystron

In this paper, the electron optics system of 340 GHz extended interaction klystron (ElK) is designed, and the design process of the 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 0.7 Tesla, 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 the electron beam is 100%, and the filling ratio is about 70% under the beam voltage of 24kV and the beam current of 210mA.