The X-band Klystron Electron Optical Systems Research

The characters of klystron are high power, high gain and high efficiency. Theklystron has been widely used in many fields, such as national defense, medicaltreatment, scientific research and so on. The electron optics system is the critical partof Klystron and it mainly researches questions of the forming of electron beam,interaction between electron beam and magnetic field. It includes electron gun,magnetic focusing system and collector. Electron beam is the source of the microwaveenergy. Electron beam have a interaction with RF field and provides higher outerpower. The performance of electron beam determines the performance of microwavetube. Designing and researching electron optics system have practical significationsand applications.The paper researches the electron optics system of X-Band high power impulseKlystron used in weather radar, states the process of designing signal beam andaxis-symmetry electron optics system. The researching uses CAD technology, such asEGUN, ANSYS, CST and so on. It adopts method of transition from two-dimensionsimulation to three-dimension simulation. The paper finds the factors affecting electronbeam through a mature gun using two-dimension simulation, analyses and optimizes.At last it designs a gun meeting requests, and then validates in three-dimensionsimulation. In focusing system, the paper modifies barrel magnetic focusing system,designs signal magnetic structure with two groups permanent magnetic. Themodification signal magnetic structure system shields high reversal magnetic field incollector area. The state of electron beam is very good.After testing Klystron, the simulation results and experience test results show thatthree-dimension is more exact. The electron optics system meets requirement ofX-Band high power impulse Klystron. The method used in the paper is feasible, andcan be used in other electron guns.