Analysis And Experimental Study Of Focusing Characteristics Of High Voltage Electron Gun Effect

High-voltage electron beam welding as a special welding technology,in the aerospace,defense and other fields of large thick parts,large volume,welding of dissimilar materials has a unique advantage,has been widely used.As China’s electron beam welding equipment research compared to foreign countries started late,especially for the core components of high-voltage electron beam welding equipment-high-voltage electron gun of the relevant theoretical reserves are still inadequate.This paper takes the domestic high-voltage electron gun F19-01 produced by Heibei Zhicheng High Energy Beam Technology Co.,Ltd.as the research object,and carries out the theoretical and experimental research on the focusing characteristics of the electron gun under different electrostatic focusing and magnetic focusing structure parameters of the F19-01 type high-voltage electron gun,and the main research contents are as follows.(1)The mapping relationship between the potential on the axis of the domestic F19-01 electron gun and the diameter of the beam waist is described,the variation law of the diameter of the electron beam waist under different cathode and anode distances,bias cup apertures and anode apertures is obtained,the variation law of the electron beam spot diameter with the diameter of the electron beam waist is obtained according to the electron optics principle,and the trajectory of the electron beam when it passes through the inhomogeneous magnetic field formed by the focusing coil is analyzed.(2)The electron beam trajectory simulation of the F19-01 electron gun was carried out by using CST simulation software.By changing the structural parameters such as cathode distance,bias cup aperture,anode aperture,focusing current,focusing coil position,yoke gap,etc.,the simulation investigates the variation of electron beam waist and beam spot diameter with the above parameters.(3)A single-parameter and four-level three-factor orthogonal experimental study of the F19-01 high-voltage electron gun.The experimental results show that the increase of cathode distance leads to the increase of beam spot diameter;the increase of bias cup aperture leads to the decrease of beam spot diameter;the increase of anode aperture leads to the decrease of beam spot diameter;the increase of focusing current leads to the decrease of beam spot diameter,and the new parameters obtained by orthogonal test can significantly improve the depth to width ratio of electron beam welding seam under the same power,and the experimental research results show that the theoretical and experimental results are consistent,which proves the correctness of the theoretical research.In summary,this paper provides theoretical and experimental guidance for improving the welding quality of domestic electron beam welding equipment for the theoretical and experimental study of the F19-01 high-voltage electron gun.