Design Of Electron Optics System For High Power Multi-beam Coupled Cavity TWT

Multi-beam TWT is developed on the basis of single beam coupled cavityTWT. It is associated with single beam TWT compared with better performance.Multi-beam TWT can achieve greater power, wider bandwidth, higher efficiencyand lower operating voltage. It can reduce the volume and weight of the whole pipe.Therefore the research of multi-beam TWT technology has great significance.The work in this thesis is the design of electron optics system for a high powerX band multi-beam coupled cavity TWT. First, the gridded centralized launchscheme was determined by the requirements of multi-beam electron gun, then thebasic structure and size of the electron gun was determined by theoreticalcalculation and simulation correction. Transverse magnetic field suppression hasbeen the difficulty of the multi-beam PPM focusing system. The method tosuppress the transverse magnetic field was given by analysing the causes oftransverse magnetic field, the differences between single and multi-beam and themain influencing factors of multi-beam transverse magnetic field. Then the basicstructure and size of the PPM focusing system was determined by the electron beamparameters and transverse magnetic field suppressing method. The electron transferrate was up to98%, compared with80%of the original scheme. A one-stage and atwo-stage depressed collector were designed on the basis of the multistagedepressed collector technology. The internal electron trajectory, secondary electronand efficiency were analyzed, and the final collector scheme was determined by theresults of the analysis.