The potential distribution and the perturbation multipole field of the different electrode defects in some electrostatic lenses were given.
计算了几个静电电子透镜的例子，给出了不同电极缺陷的电位分布和微扰多极场分布。
2
General expressions of the magnetic vector potential for multipole fields are derived.
推导出了用多极场空间谐波函数表示的磁矢位的通项表达式。
3
Physically in consideration of the multipole moments, by using supplementing charges, there can be derived in this paper the potential at great distances due to a localized charge distribution.