动态束源和电磁参数下高压电子枪聚焦特性

Focusing Characteristics of High Voltage Electron Guns under Variable Electromagnetic and Beam Source Parameters

以国产ZD-VEBW系列高压电子枪为研究对象,通过理论分析电子枪轴上电位与束腰和束斑直径之间的映射关系以及带电粒子经过聚焦线圈时的运动轨迹,借助于CST仿真平台,构建了电子枪仿真模型。仿真得到了电子束束斑直径在不同静电聚焦结构参数下的变化规律,依据此规律设计了不同孔径的偏压杯、阳极,构建了电子束焊接试验平台;动态调整阴阳极距离和束源参数,进行了电子束焊接的单参数以及正交试验的研究。结果表明:阴阳极距离的增加会导致束斑直径增加,偏压杯孔径的增加会导致束斑直径的减小,阳极孔径对束斑直径的影响存在最优参数,聚焦电流的增加会导致束斑直径的减小;阴阳极距离取28.40 mm、偏压杯孔径取6.00 mm、阳极孔径取10.00 mm时,能够显著提高试验型号设备同功率下电子束焊缝的深宽比,有效提高国产化ZD-VEBW系列高压电子枪的焊接性能,验证了理论和仿真分析的正确性。

The domestic ZD-VEBW series high-voltage electron gun was taken as the research object,and the mapping relationship among the potential on the electron gun axis and the beam waist and beam spot diameter,as well as the movement trajectory of the charged particles when passing through the focusing coil,was analyzed theoretically.The CST simulation platform was used to build the electron gun simulation model.The variation law of electron beam spot diameters under different electrostatic focusing structure parameters was obtained by simulation.According to the rule,bias cups and anodes with different apertures were designed,and an experimental platform for electron beam welding was constructed.The distance between cathode and anode and beam source parameters were dynamically adjusted,and the single-parameter and orthogonal experiments of electron beam welding were studied.The results show that the increase of the distance between the cathode and the anode leads to the increase of the beam spot diameter,and the increase of the bias cup aperture leads to the decrease of the beam spot diameter.When the distance between the cathode and anode is as 28.4 mm,the diameter of the bias cup is as 6.00 mm,and the diameter of the anode is as 10.00 mm,the aspect ratio of the electron beam weld under the same power of the test model equipment may be significantly improved.The performance of the tested homemade ZD-VEBW series high voltage electron guns is effectively improved,which verifies the correctness of the theoretical and simulation analysis.