Introductory Survey

Abstract

The production, control, and utilization of charged particle beams are the subjects of electron and ion optics, a branch of physical electronics. The name expresses the close analogy between the transmission of light through refractive media and the motion of charged particles in electromagnetic fields. It is a huge field with a relatively short history. Although the analogy between classical mechanics and geometrical optics was discovered by Hamilton in the first half of the last century, the world had to wait almost 100 years until H. Busch⁽¹⁾ proved the possibility of image formation by electrons in 1926. The list of applications is long. Television and display tubes, electron microscopes, particle accelerators, mass spectrometers, microwave oscillator and amplifier tubes, and the tools of electron beam manufacturing (e.g., welding, drilling, melting, cutting, refining, and alloying) technologies are the well-known classical applications. Electron and ion microprobes, energy analyzers, electron spectrometers, and ion implanters are among the more recent practical results of the development of this rapidly growing field. Analytical chemistry and surface science could hardly exist without electron and ion optics. New applications emerge in the areas of fusion and energy transmission. The growing importance of the field has recently been recognized by the American Physical Society by the establishment of a special topical group on particle beam physics. Many thousands of papers and dozens of books^(2-51b) have been published on the subject.