ﺼﻤﯿﻢ ﻗﺎذف اﻟﻜﺘﺮوﻧﻲ ﺑﺎﺳﺘﺨﺪام ﻋﺪﺳﺔ ﻣﻐﻤﻮرة ﺛﻨﺎﺋﯿﺔ اﻻﻗﻄﺎب‬ ذات زﯾﻮغ ﻗﻠﯿﻠﺔ

Abstract

Abstract A two electrode immersion electrostatic lens used in the design of an electron gun, with small aberration, has been designed using the finite element method (FEM). By choosing the appropriate geometrical shape of there electrodes the potential V(r,z) and the axial potential distribution have been computed using the FEM to solve Laplace's equation. The trajectory of the electron beam and the optical properties of this lens combination of electrodes have been computed under different magnification conditions (Zero and infinite magnification conditions) from studying the properties of the designed electron gun can be supplied with Abeam current of 5.7*10-6 A , electron gun with half acceptance angle of (5mrad)