Electromagnetic radiation that is emitted by charged particles moving at relativistic speeds in circular orbits in a magnetic field. The rate of emission is inversely proportional to the product of the radius of curvature of the orbit and the fourth power of the mass of the particles. For this reason, synchrotron radiation is not a problem in the design of proton synchrotrons but it is significant in electron synchrotrons. The greater the circumference of a synchrotron, the less important is the loss of energy by synchrotron radiation. In storage rings, synchrotron radiation is the principal cause of energy loss.
However, since the 1950s it has been realized that synchrotron radiation is itself a very useful tool for studying the structure of matter and many accelerator laboratories have research projects making use of the radiation on a secondary basis to the main high-energy research. The radiation used for these purposes is primarily in the ultraviolet and X-ray frequencies.
Much of the microwave radiation from celestial radio sources outside the Galaxy is believed to originate from electrons moving in curved paths in celestial magnetic fields; it is also called synchrotron radiation as it is analogous to the radiation occurring in a synchrotron. Synchrotron radiation is also predicted to exist for gravitational radiation.
http://www-als.lbl.gov/als/ Website of the Advanced Light Source facility at Berkeley
http://www.diamond.ac.uk/default.htm Website for the Diamond + Light Source at Harwell