Book excerpt: Focusing of Charged Particles, Volume II presents the aspects of particle optics, including the electron, the ion optical domains, and the accelerator field. This book provides a detailed analysis of the principles of the laws of propagation of beams. Comprised of three parts encompassing three chapters, this volume starts with an overview of how a beam of charged particles traverses a region that is at a uniform, constant, electrostatic potential. This book then discusses the principle of charge repulsion effect by which the space charge of the beam modifies the potential in the region that it traverses. Other chapters examine the general design techniques and performances obtainable for electron guns applicable for use in initiating a beam for linear beam tubes that is given in a condensed form. The last chapter deals with the two stable charged particles that can be accelerated, namely, protons and electrons. This book is a valuable resource to physicists, accelerator experts, and experimenters in search of interactions in the detector target.