Investigation Of Characteristics Of Intense Relativistic Electron Beam Transportation

As far as most of the high power microwave source is concerned, the mechanism of microwave generation is to make use of the interaction between beam electrons and microwave, during which the energy of the electron beam transfers to the microwave, and the power of the microwave is generated or amplified. Therefore, the study of electron beam emission and transportation is important to the research of microwave devices. Because of this importance, the motion of beam electrons under the circumstances of radial emission and axial emission has been studied in the following parts: theoretical analysis, PIC (particle-in-cell) method and numerical computation. The results of the study are all reasonable and valuable, and will offer a theoretical guidance to the design of microwave devices.In theoretical analysis, the motion of radially-emitted electron beam in diode region and drift region has been analyzed, and the relation between radial momentum or current of electron beam and the guiding magnetic field has also been studied, then the possibility to optimize the guiding magnetic field has been derived. The motion of radially-emitted beam electrons in smooth bore magnetron and smooth bore MILO has also been studied theoretically. At last, the motion of radially-emitted beam electrons in compound axial and azimuthal magnetic field has been studied.In addition to PIC method, the numerical computation method is used as a compensation for the study of the characteristics of electron beam. The two methods are used separately to attain the trajectory of axially-emitted electron beam in diode region and drift region, and the trajectory of radially-emitted electron beam with axial, azimuthal ,as well as compounded axial and azimuthal magnetic field. Three two-dimensional codes and two three-dimensional codes have been made out to compute the trajectories. At last, the results attained by the two methods are in good agreement.At the end of the thesis, the basic physical characteristics of axially-emitted and radially-emitted electron beam are summed up, and the design methods of SWS (Slow Wave Structure) for high-efficiency beam-wave interaction according to the motion characteristics of E-beam are brought forward, these helpful discussions for design of microwave source are going to be validated by PIC method.