Computer-aided design of an electrostatic mirror of improved aberrations.

number: 
566
English
department: 
Degree: 
Imprint: 
Physics
Author: 
Mayada Monther Majeed Al-Azzawi
Supervisor: 
Dr. Sabah M. Juma
Dr. Ahmad K. Ahmad
year: 
2002
Abstract:

A computational investigation has been carried out on the design and properties of electrostatic mirror. The work has been focused on suggesting several mathematical expressions to represent the axial potential of an electron mirror. The functions that have been taken into consideration were those which gave rise to the mirror action. The electron beam path under finite and zero magnification conditions has been investigated as a mirror trajectory with the aid of the Runge-Kutta method. The electrodes shape of each mirror has been determined in two and three dimensions. In the present work the profile of all the mirrors determined from the suggested potentials are of the two-electrode type with an axial bore to provide a passage for the electron beam undergoing a mirror trajectory. The spherical and chromatic aberration coefficients of each mirror have been computed and normalized in terms of the focal length. The choice of the mirror depends on the operational requirements, i.e. whether it is intended to operate the mirror in an electro-optical system at low spherical aberration or low chromatic aberration. Computations have shown that the suggested potentials gave rise to mirrors of excellent performance in Comparison with those published in the literature.