Synchrotron Radiation

Abstract

The radiation emitted by a charged particle in uniform circular motion is called synchrotron radiation. Radiation of this kind is generated, in particular, whenever a charged particle moves under the influence of a static magnetic field varying only little in space. Synchrotron radiation is hence emitted by circular high-energy particle accelerators, whose strong magnetic fields are generated by powerful superconducting electromagnets, but also by charged particles moving in the much weaker natural magnetic fields that wrap, for instance, the Earth and the planet Jupiter. However, some of the most spectacular ultrarelativistic sources of this type of radiation are extraterrestrial, as for instance the famous Crab Nebula, although their magnetic fields are considerably weaker than that of the Earth. In this chapter we investigate the main characteristics of the synchrotron radiation, especially its frequency and angular distributions and its polarization. We will see that, notably in the ultrarelativistic limit, this radiation possesses peculiar physical properties, which allow to undoubtedly establish its presence experimentally.