Editing Insertion device (section)

==History==
The theory behind undulators was developed by [[Vitaly Ginzburg]] in the [[USSR]]. However it was Motz and his team who in 1953 installed the first undulator in a linac at Stanford, using it to generate millimetre wave radiation through to visible light.<ref>{{cite web|last=Robinson|first=Arthur L.|title=X-Ray Data Booklet: History of Synchrotron Radiation|url=http://xdb.lbl.gov/Section2/Sec_2-2.html|accessdate=4 September 2011}}</ref>

It was not until the 1970s that undulators were installed in electron storage rings to produce synchrotron radiation. The first institutions to take these devices were the [[Lebedev Physical Institute]] in [[Moscow]], and the [[Tomsk Polytechnic University]]. These installations allowed a fuller characterisation of the behaviour of undulators.

Undulators only became practical devices for insertion in synchrotron light sources in 1981, when teams at the [[Lawrence Berkeley National Laboratory]] (LBNL), [[Stanford Synchrotron Radiation Laboratory]] (SSRL), and at [[Budker Institute of Nuclear Physics]] (BINP) in Russia developed permanent magnetic arrays, known as [[Halbach array]]s, which allowed short repeating periods unachievable with either [[electromagnetic coil]]s or [[superconducting magnet|superconducting coil]]s.

Despite their similar function, wigglers were used in [[storage ring]]s for over a decade before they were used to generate synchrotron radiation for [[Beamline#Synchrotron radiation beamline|beamline]]s. Wigglers have a [[radiation damping|damping]] effect on storage rings, which is the function to which they first put at the Cambridge Electron Accelerator in Massachusetts in 1966. The first wiggler used for generation of synchrotron radiation was a 7 pole wiggler installed in the SSRL in 1979.

Since these first insertions the number of undulators and wigglers in [[List of synchrotron radiation facilities|synchrotron radiation facilities]] throughout the world have proliferated and they are one of the driving technologies behind the next generation of light sources, [[free electron laser]]s.

[[File:Undulator (english).svg|thumb|Schematic sketch of an [[undulator]]]]