Editing Linear particle accelerator (section)

=== Energy recovery linac ===
In previous electron linear accelerators, the accelerated particles are used only once and then fed into an absorber ''(beam dump)'', in which their residual energy is converted into heat. In an energy recovery linac (ERL), the accelerated in resonators and, for example, in [[undulator]]s. The electrons used are fed back through the accelerator, out of phase by 180 degrees. They therefore pass through the resonators in the decelerating phase and thus return their remaining energy to the field. The concept is comparable to the hybrid drive of motor vehicles, where the kinetic energy released during braking is made available for the next acceleration by charging a battery.

The [[Brookhaven National Laboratory]] and the [[Helmholtz-Zentrum Berlin]] with the project "bERLinPro" reported on corresponding development work. The Berlin experimental accelerator uses superconducting niobium cavity resonators. In 2014, three [[free-electron laser]]s based on ERLs were in operation worldwide: in the [[Thomas Jefferson National Accelerator Facility|Jefferson Lab]] (US), in the [[Budker Institute of Nuclear Physics]] (Russia) and at JAEA (Japan).<ref>{{Cite book|url=https://www.springer.com/gp/book/9783319143934|title=Synchrotron Light Sources and Free-Electron Lasers: Accelerator Physics, Instrumentation and Science Applications|date=2016|publisher=Springer International Publishing|isbn=978-3-319-14393-4|editor-last=Jaeschke|editor-first=Eberhard|language=en|editor-last2=Khan|editor-first2=Shaukat|editor-last3=Schneider|editor-first3=Jochen R.|editor-last4=Hastings|editor-first4=Jerome B.}}</ref> At the [[University of Mainz]], an ERL called MESA is expected to begin operation in 2024.
<ref>{{cite journal |last1=Hug |first1=Florian |last2=Aulenbacher |first2=Kurt |last3=Heine |first3=Robert |last4=Ledroit |first4=Ben |last5=Simon |first5=Daniel |title=MESA - an ERL Project for Particle Physics Experiments |journal=Proceedings of the 28th Linear Accelerator Conf. |date=2017 |volume=LINAC2016 |pages=313–316 |doi=10.18429/JACoW-LINAC2016-MOP106012 |url=https://inspirehep.net/literature/1633150 |access-date=18 August 2024}}</ref>