Research And Application On Electron Optical System Of Sheet Beam Traveling Wave Tube

Due to limitations of the cylindrical axisymmetric electron beam, resulting in that it can not meet the growing frequency, power requirements of microwave devices. Since the 1990 s it has became a hot topic again, sheet electron beam with its low space charge field, capable of transmitting high-current and other unique advantages is constantly being pioneering and innovating. So research on sheet electron beam is becoming a trend, a necessity. Research on sheet beam TWT is more and more attention. As an important part of the sheet beam TWT, sheet beam electron optical system has a great impact on its performance. At present, the main difficulty of sheet beam microwave devices lies in the transport and focus of sheet beam, so the research on sheet beam electron optical system is especially necessary.In this paper, sheet electron beam generation, transmission and collector are conducted in-depth research, the main content of work as follows:First、a summary of basic structure and principle of the sheet beam TWT electron optical system, and the basic theory of sheet beam electron optical system, especially focus on focus theory of several magnetic fields.Second, it uses indirect and direct methods to produce sheet electron beam. It uses the field of magnetic quadrupole pair to compress cylindrical electron beam to get sheet electron beam, analyzes the influence of the main parameters to the electron beam shape; Then cathode electron gun with an oval face produced a sheet electron beam.Third, on the focusing and the transmission of the sheet electron beam, some researches on three magnetic field focus to the same sheet electron beam has been done, including a uniform magnetic field, wiggler magnetic field and PCM magnetic field, analyzes the reasons for the formation of different electron trajectories. Summarized their focusing effect, and analyzed a variety of applications. Specially,it presented a lateral groove wiggler magnetic field for focusing sheet electron beam generated by the indirect method, its advantages and effect are obvious.Four, with two different software CST particle studio and MTSS,it has done some design and research on sheet beam collector, proposed a two-stage depressed collector rhombic collector structure, tested its collection performance by simulation. And analyzed the reason of using the depressed collector and adopting the single-stage collector under static circulation condition.Through this study, the design of sheet beam electron optical system became to a whole one, making the design process easier, also has laid an important foundation for sheet electron beam research.