磁圆形透镜和磁六极透镜的复合系统的象差

近来磁六极透镜作为球差校正器引起了人们的注意。本文研究了磁圆形透镜和磁六极透镜的场分布叠加形成的复合系统的象差。我们在复数域中定义了内积,采用了复数的表象和微分算符,全面讨论了这种复合系统的高斯光学性质及二、三、四级象差,得出了各级象差所有的象差系数的公式。 关键词：

THE ABERRATION THEORY OF A COMBINED MAGNETIC ROUND LENS AND SEXTUPOLES SYSTEM

Recently the sextupoles have drawn much attention in literatures, for sextupoles can be used to compensate for the third-order spherical aberration of round lenses. In the present paper, the aberration theory of a combined magnetic round lens and sextupoles system with superimposed fields has been studied. Defining an inner product in the complex number field and using the complex representation and differential operators, we have treated both the Guassian dioptrics and the electron optical aberrations up to the fourth-order in this combined system comprehensively. All aberration coefficients have been derived in explicit form.