Design And Study Of Beam Forming System Of High Power Electron Beam Gun

With the development of the manufacturing and aerospace industries, the demand of processing metals difficult to melted has been put on the agenda. These metals with high melting points are very oxidizing. Even the temperatures is lower than their melting temperatures, they will have been already oxidized. Thus limits their application. Electron beam melting technology can solve the melting point and purity issues in the smelting of refractory metals. As a core of electronic beam melting furnace, the simulation and design of the electron beam forming process in the high-power electron gun will provide an important reference for electron beam melting furnace design.With the target of designing the electron gun using in250KW high-power electron beam furnace, we take the focus on the forming system of the electron beam. By the CST simulation for electronic emission, accelerating and the first focus process, we can gain to an electron gun structure model meeting the requirements. According to the study of the relationship between the parameters of electron beam forming system and the properties of electron beam, we can optimize the structure of the electron gun model, summarizes the conclusions which can guide the actual production.On the basis of the basic compositions and working principles of the electron beam furnace and electron gun, and then Combined with the basic principles of electron optics and the empirical formula of electron gun design, we get the preliminary data of the forming structure and parameters such as voltage and current. It’s just the CST simulation we can test the model. After analyzing the relationship between the parameters of electron beam forming system and the properties of electron beam we can find some conclusions. Increasing the distance between the cathode and anode block, reducing the outside edge of the cathode block, reducing the diameter of die hole of the spotlight pole and reducing the bunching cone angle will make a raising of the radial acceleration electric field intensity, which will make the role of electronic convergence increasing, and the stability of the electron beam will be destroyed. Moving the first focus coil position behind, increasing the diameter of the focus coil, increasing the thickness of the focus coil can improve the uniformity of the radial magnetic field. Following this case the stability of electron beam will be improved, too. Reducing the turns on the front of the coil will reduce the over focusing before the magnetic focusing process, which can also improve the stability of the electron beam. According to the above conclusions, the forming system of the electron beam can be optimized. The model optimized could get a flow rate of100%of the electron beam, and the change rate of the beam diameter will decline in20%below.