## What is Synchrotron Radiation?Synchrotron radiation is the electromagnetic radiation emitted when charged particles travel in curved paths. Because in most accelerators the particle trajectories are bent by magnetic fields, synchrotron radiation is also called Magneto-Bremsstrahlung. The emitted spectrum is broadband from the microwave (harmonics of the driving RF field) to x-ray spectral regions. The radiation is vertically collimated and polarized. The synchrotron radiation output can be calculated if the electron energy E, bending radius ρ, electron current I ## Properties of Synchrotron RadiationSchwinger derived a formalism which allows us to calculate the synchrotron radiation spectrum and other properties like its distribution in space. For SURF, the equation for the radiation power is given by
The radiation power is a function of the wavelength λ, electron energy γ=(E/m ## Synchrotron Radiation SpectrumUsing Eq. 1 the synchrotron radiation spectrum for SURF can be calculated. Assuming a bandpass of 1% of the wavelength, a horizontal acceptance angle of 50 mrad, a vertical half acceptance angle of 25 mrad, 0 mrad tilt from the orbital plane, a beam current 100 mA, electron energies from 416 MeV to 78 MeV, and an orbital radius of 0.8371 m the output power of SURF is illustrated in figure 2. ## Vertical Angular DistributionThe Schwinger equation can be used to calculate the vertical angular spread of synchrotron radiation and its polarization. The radiation power with polarization parallel to the orbital plane is given by
and the radiation power with polarization perpendicular to the orbital plane is given by
Figure 3 shows to vertical angular spread for the wavelengths 13 nm, 121 nm, and 1064 nm at an electron energy of 380 MeV. |
Figure 1: Geometry of synchrotron radiation collection. Figure 2: Synchrotron Radiation Spectrum emitted by SURF at 416 MeV,380 MeV, 331 MeV, 284 MeV, 234 MeV, 183 MeV, 134 MeV, and 78 MeV in comparison to a 3000 K blackbody and a deuterium lamp. Figure 3: Vertical angular spread of the synchrotron radiation at SURF for 13 nm, 121 nm, and 1064 nm wavelength at 380 MeV. |

# What is synchrotron radiation?

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Created March 02, 2010, Updated August 25, 2016