Abstract
In this paper, the Complex System, that electrostatic lens of two equal radial cylinder is superimposed with the deflection field, has been introduced. On the principle of minimal action, functional minimum and Euler equation has been Solved. The results show properties of Gauss trajectory and rank third in aberration. Aberrations include three parts, and can express as matrix. The electrons can go back to Zaxis. Aberration can cancel out each other, and obtain better spot performance. When electrostatic lens is placed near screen, big aberrations will be produce.
