Synchrotron radiation is an electromagnetic wave, just like sunlight, that is emitted from relativistic charged particle, i.e. charged particle like proton or electron moving near the speed of light, under acceleration, for e.g. via a magnetic or an electric field. Synchrotron light received its name from the machine it was first discovered, in 1947, the 70 MeV synchrotron accelerator at the General Electric Research Laboratory in Schenectady, New York.
Notable characteristics of synchrotron radiation are as followed.
1. Broad spectrum
The spectrum of synchrotron radiation generated from an electron storage ring is a broad continuous one, covering from very low energy range, in the infrared region, up to very high photon energy in the x-ray region. This flexibility in choosing suitable photon energy (tunability) for a particular type of experiment makes synchrotron light favorable for a wide variety of research studies.
2. High brightness
The generated synchrotron radiation is extremely bright, millions of times brighter than sunlight, and much brighter than light from conventional laboratory sources. This permits researchers to study extremely diluted samples, i.e. samples with very low concentration of constituent atoms, or weakly scattering crystals, with sufficient signal-to-noise ratio.
3. High degree of collimation
The synchrotron light is emitted from accelerated charged particle beam in a very narrow cone, enabling full use of the available photon flux.
4. Well-defined polarization
Generated synchrotron light has well-defined polarization. Normal synchrotron radiation from bending magnets and planar insertion devices (special magnets that can be inserted into a storage ring) is linearly polarized, while circularly or elliptically polarized synchrotron light can be generated from specially designed insertion devices.
5. Pulsed time structure
Since synchrotron light is emitted by electron bunches circulating a storage ring, it has a similar pulsed time structure. This allows researchers to perform in-situ measurement, i.e. study the mechanism of a process as it is occurring, down to sub-nanosecond time scale resolution.