Electrostatic Lens Systems, 2nd edition

to design lens systems for focusing beams of

charged particles having useful characteristics.

The text covers the basic theory of the motion of

charged particles in electrostatic fields and

describes several methods for the calculation of

the potential and field distribution for various

electrode geometries. Two methods, the Bessel

function expansion method which was developed

by the author and his students and the nine-point

implementation of the finite difference method, are

given special emphasis because they are

particularly appropriate for implementation by the

inexperienced user. Other methods are discussed

in less detail and reference is made to WWW sites

from which demonstration programs for these

methods may be obtained. A chapter on

aberrations presents formulae which enable the

coefficients to be determined by an extension to

the ray tracing procedures and which

demonstrates optimum conditions for lens

operation.

The book is accompanied by a disk providing a

suite of computer programs (LENSYS for

MS-DOS) intended for practical use in the design

and analysis of systems using round lenses with

apertures or cylindrical elements. These

programs will be of value even to experienced

workers in the field who may be quite familiar with

much of the material in the text..