Simulation Design And Research The Focusing System Of Powerful Current Pierce Electron Gun’s Electron Beam

The generation and stable transport of cylindrical electron beam comes within the scope of many subjects, such as microwave electronics, plasma electronics, electromagnetic fields and microwave techniques, vacuum technique, materials science, which is a complex fundamental utility research problem.The powerful current pierce gun of Smelting technology, its work process, including electron beam generation, acceleration, focusing and deflection, focusing system is to achieve one of its key applications. The axial Pierce electron gun of length focus for the melting because it has to be away from the pool and cathode materials to minimize pollution, long life, big power, easy operation, etc, attracted the attention of researchers. Currently high-power electron gun focusing system for the study design is not very system, needs further study, gradually improve the quality and material properties of the electron beam to improve the electron beam processing technology to expand e-beam processing in practical engineering applications, play the biggest advantage of electron beam processing.Powerful current electron optics system including electron gun(responsible for the generating of electron beam)and magnetic focusing system(responsible for focusing of electron beam), which is designed as electron beam melting and practical high-power electron gun beam focusing system and an electron source, has many important applications. Electron gun is the core component in electron beam processing, If there is no focusing system, due to the existence of a strong internal electron space charge repulsion of their own-divergent forces, is bound to hinder us to achieve the required electron, must try to overcome this contradiction. Using magnetic force may overcome the convergence divergence of the space charge force to gain the required electron beam. Pierce electron gun in a high-current electron beam melting, electron beam welding, etc. are important applications, want to get a electron beam with stable, injection-like distribution and good focuing effect.Now its domestic Simulation design research has not involved. This thesis work is carried out based on the actual needs of the250kw powerful current electron beam furnace, the focusing system of powerful current pierce electron gun’s electron beam is used to simulation design and research. Powerful Current electron optics and electron beam processing technology of powerful current electron optics are outlined and illustrated, a higher circulation rate and stability problem of the focusing system of powerful current pierce electron gun’s electron beam is studied and investigated, using particle simulation software CST and electromagnetic software Analysis Ansys, and getting some practical results:change the focus coil width and relative position of the electron beam has little effect, change the focus coil thickness and the current value of the electron beam has the greatest impact, the focusing electrode of close to pierce gun cathode can extremely inhibit enhancement of the net current density, providing the steady-state SCL current value, thickness of close to pierce gun cathode have a great influence on the electron beam, etc.According to the existing designing methods of electron gun, with the reference of the nature of optical system to do the theoretical calculation, and then design the maximum efficiency focusing system of the electron gun. Meanwhile optimize the geometric parameters between the first focus and the second focus, ensure the different parameters of the electron gun’s focusing system with comparison and simulation. And finally, use electrostatic, magneto static, and particle solver to simulate the electron gun’s electron beam concentrated beam successfully. Detailed analyses of gun focusing system geometry parameters how to affect electron beam quality is given, some useful rules are summarized for the design and optimization of axisymmetric powerful current pierce electron gun’ electron beam focusing system: width and relative position of the coil changes the magnetic field has little effect on the focus, therefore, in the width direction of electron beam shape remains very good; thickness of the coil changes the magnetic field has little effect on the focus, use the focus of immersion, affect the particle emission source, through only high energy particles, but the number is too small, energy is also small, is not desirable, etc. This project verifies the focusing system which under the CST’s stimulation with the Ansys software; further proves the design’s reliability and feasibility by comparison and analysis the stimulated results of the different software to get the parameter’s characterize of the electron gun’s focusing system, and provides the practical reference.The paper, by optimizing the design to obtain electron beam has a well-focusing system.lt is ensure that the first focus to generate the required electron beam waist; ensure adjustment of the electron beam in the pool on the second path have a greater focus adjustment range to meet the temperature requirements of the smelting process; ensure a higher flow rate of the electron beam, the focused electron beam to ensure a higher stability; ensure the movement state of outer electrons of electron beam and changes of radius in outer electron motion, product electron beam of meet the requirements. Simulation results match with the design theory. Laminar flow is good, fill factor greater than60%, injection flow rate of100%, so that performance of focusing system of the whole high current Pierce electron gun electron beam may achieve optimal.