Sheet Note The Theoretical Study Of Electron Gun

Vacuum electronics is a important subject which involves electromagnetics, material science, mathematics and many other fields. Along with the development of millimeter-wave technology, vacuum electron devices have seen widespread use in both defence and commerce. The advent of new materials and structures keeps modifying the properties of vacuum devices, giving them an irreplaceable status in applications in super high band, which is above the millimetric wave band. However, for vacuum devices working in millimetric wave band and above, super high band, there are great limits on the size, and the higher the frequency band, the smaller the size has to be. As a result, electron sources for traditional devices are not qualified to being the source of millimeter-wave apparatuses. Many scientists have been giving their priorities to seeking new electrons sources and they have discovered, through persistent exploring and studying, that sheet electron beam can meet the demand for new electron source of millimeter wave devices: First, a sheet electron beam has small cross section, satisfying our need for smaller-sized new sources; Second, its huge space charge density enables it to transmit enormous electric current with rather tiny transverse size; Furthermore, the space-charge effect of it is relatively insignificant, which lowers requirements for its focusing system. Based on the analysis above, we hold that sheet electron beams are very suitable for being the source of millimter-wave devices, and bound to replace the traditional circular and cylindrical electron beams.In this paper, we do some discussion and theoretical research on the production of sheet electron beam by direct method, by which sheet beam can be produced by sheet electron gun directly.First, we present a detailed deduction and analysis of the traditional Pierce electron guns and then, based on this traditional work, we probe further into theories on rectangular and elliptical sheet electron beams. A numerical approach to major rectangular sheet electron beam problems is achieved, which lies a solid foundation for the final theoretical and numerical solutions to elliptical sheet electron beam problems.Second, we also use CST particle simulation software to have a simulation research on traditional Pierce guns, rectangular and elliptical sheet beam electron guns so as to confirm the exactness of our theoretical analysis and provide a theoretical basis for designs of sheet beam electron guns.Finally, we compare the theoretical and simulation results between the traditional Pierce electron gun and rectangular sheet electron beam gun. So we can further verify the correctness of theoretical analysis.