ABSTRACT
Electric and magnetic fields act on the intrinsic charge of electrons and ions through the force known as the Lorentz force, after the physicist who first identified it in the nineteenth century. By bombarding with a very high energy beam, the atomic nucleus can dissociate into its constituent elementary particles. Energetic ions appear as cosmic rays which pervade interstellar space, and bombard the earth's atmosphere in large numbers. A large variety of subnuclear particles are produced in high energy particle accelerators. Practical charged particle beams range in energy from a few eV to about fourteen trillion eV. A charged particle beam is conceptually similar in many respects to a beam of light. It is therefore interesting to think about charged particle optics in an analogous way to light optics. The inherent high resolution, together with the unique interactivity with matter thus constitutes two fundamental advantages of charged particle beams.
