Undulator
Encyclopedia : U : UN : UND : Undulator
An undulator is a device from high-energy physics and usually part of a larger installation, a synchrotron. It consists of a periodic dipole magnet structure. The static magnetic field is alternating along the length of the undulator with a wavelength [\lambda_u]. Electrons traversing the periodic magnet structure are forced to undergo oscillations and radiate. This process is very similar to Thomson scattering.
The important dimensionless parameter
[K=\frac,]
where e is the electron charge, B the magnetic field, m the electron rest mass and c the speed of light, characterises the nature of the electron motion. For [K\ll1] the motion of the electron can be considered linear and this is the undulator regime. If [K\gg1] the electron motion becomes highly non-linear which leads to radiation of harmonics. This is the wiggler regime.
External links
D. T. Attwood's page at Berkeley: [Soft X-Rays and Extreme Ultraviolet Radiation]. His lecture and viewgraphs are available online.
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.