ABSTRACT
This chapter focuses on light sources such as synchrotron radiation (SR) light sources and Compton light sources. The success and widespread use of SR and Compton sources is thanks to their flexible spectral parameters. This allows one to select the photon energy required for an experiment by adjusting the energy of the beam or laser, or the field strength of wigglers or undulators. The chapter discusses the generations of SR sources. High-intensity photon flux allows for either rapid experiments or the use of weakly scattering objects or crystals. The Compton scattering can be very useful for creating compact X-ray sources, enabled by the development of electron accelerators and laser technologies. Further enhancement of the brightness of the linac-based Compton source can be achieved by employing the method of energy recovery. Another type of Compton source is one based on an electron storage ring.
