Electron and positron sources

Particle accelerators and sources are currently used for scientific, technological and medical applications. These devices provide low or high energy, charged or neutral particle beams employed as a function of their physical characteristics, like the current, the density, the beam duration, size and divergence. Electron sources play an important role in this context because they are easy particles to produce and because relatively simple technological systems of reasonable cost can be used to generate electron beams. Positron sources, have recently acquired an increasing interest in medical science and material diagnostics. In this chapter, the concept of particle source and the main designs and characteristics of electron and positron sources will be illustrated.