تصمیم حاسوبي لعدسة كھروستاتیكیة ثلاثیة الأقطاب

Abstract

A low aberration electrostatic lens of three electrode was design, The
electrode shapes were determined using solution of Laplace equation .
A new Computational technique were used to design an electrostatic lens
which depends on the determination polynomial function of the third order with
the solution of axial - equation to find the trajectory of particles which satisfy
the suggested potential function besides the other optical properties such as
brightness ,perveance and current density.
The results showed low values of spherical and chromatic aberrations
comparing with other searches about1.4 for spherical aberration and 0.98 of
chromatic aberration with values of potential of 20 which are considered as good
criteria for good lens’s design.