以电子束偏转磁场的像差和畸变为目标,对参量进行非劣解中找出贴近理想的最优解.以SDS-3电子束曝光机的磁复合偏转系统为基础,分析了像差与电子束主轨迹的关系.并给出了磁聚焦和静电的偏转场相复合情况下竖轴的3级几何像差系数和1级色差系数公式.应用中表明,复合系统结构简单紧凑,像差小而可以不用动态校正.

This paper describes the aberration and distortion of e-beam deflection magnetic field in which the parameters keep close to in the normal solution. The relationship between the principal trajectory of e-beam and aberrations has been investigated in combined round magnetic lenses and deflection system of SDS-3 e-beam machine.Formulae for the first-order chromatic and third-order geometrical aberration coefficients of superimposed magnetic focus and deflection field of both electric and magnetic type in the case of a point source on the Z-axis are obtained.The aberration of superimposed focus-deflection system is so small that the dynamic correction is unnecessary.