Ribbon Note The Electron Gun

For the Applications of electronic countermeasure, satellite communication, deep space instrumentation, highpower millimeter wave and THz device, with high current density and intense beam current are urgent need. Sheet electron beam is one of the most important one. Compare with annular or pen electron beam, the sheet electron beam has many advantages in higher frequency vacuum electronic devices. Firstly, we can extend its wide. That is means that we can improve the current infinitely in theory. So the devices can have higher power. Because of the limit of the space charge force, the current of annular or pen electron beam can not be increased infinitely, so the devices'power is limited. Second, for shorten wavelength vacuum devices, the traditional cylindric slow wave structure is too hard to fabricate.The sheet beam electron gun and sheet beam propagation are studied in the paper. Based on the principle of dynamics and the principle of pierce gun, the principles and the design technology of miniaturization sheet beam electron gun are analyzed. The immersion focusing magnetic field is adopted in this dissertation.The gun is investigated detailed in two-dimensional and three-dimensional PIC simulation. The effects of the magnetic field, the distance of two electrodes, the thickness of the superstratum and the voltage of the anode on the transmission characteristic of the sheet beam are studied, respectively. The simulation result that a strong magnetic field plays an important role reducing the pulsation wavelength and amplitude, and restraining the distortion of the sheet beam effectively. The superstratum solves the design and machining of the cathode. The electron can keep horizontal movement after emit the surface of cathode when the structure of the superstratum is improved. The increase of the distance between cathode and anode is good to decrease the pulsation amplitude and the shape of the sheet beam. But it decreases the current. The increase of the voltage can increase the current. But it also increases the pulsation wavelength and amplitude, and destroys the stabilization of the sheet beam.In order to decrease the distortion of the beam, append grid to the anode is used. The results of PIC simulation show that when append grid to the anode can increase the current and the current density.It is a good reference for further development on miniaturization vacuum electronic devices on high frequency.