Enhancing ERL development in the UK

Lead Research Organisation: Lancaster University
Department Name: Engineering

Abstract

Energy recovery linacs (ERLs) have the potential to underpin the physics reach of future high-energy physics experiments by allowing the generation of high power electron beams with only modest RF power consumption. This is achieved by extracting the kinetic energy of the spent bunches by decelerating them and using this energy to accelerate new bunches, thus drastically reducing the overall power consumption of the accelerator. Multi-turn ERLs are of particular importance for accelerating electrons to 10s of GeV in a cost effective manner. ERLs are seen as an enabling technology for future high-intensity lepton-hadron colliders (FCC-eh, LHeC, EIC) and FEL facilities (UK-XFEL). Over the next 4-5 years, it is expected that the international ERL community will begin prototyping of relevant technologies and test facilities. The main purpose of this proposal is to maintain the UK's international leadership in accelerator R&D related to ERLs.

Superconducting RF (SRF) technology is essential to the operation of an ERL, and the high delivered beam powers demand development of machine protection and related diagnostics. Finally, the beam line designs, including the topology and interleaving of new and old bunches in the machine over multiple turns - known as the filling pattern - are an important new area of study since recent UK studies have shown the potential for major improvements in performance using optimised bunch patterns. The Cockcroft Institute has world-leading expertise in all of these areas and accordingly have identified these areas as high priority. Hence the research undertaken within this project will address these areas to enhance the UK's continued leadership.

The UK Accelerator R&D Roadmap by PPTAP will highlight potential societal applications of ERLs that could occur on smaller scale facilities than those required for future colliders. Of particular interest are those in light sources, namely a monoenergetic gamma source driven via inverse Compton scattering, and high average power Free Electron Lasers with synergies to a UK-XFEL. A mid-scale ERL facility addressing these could also be a platform for timely deployment of the key technologies required for future collider projects. Within this roadmap, all three high-priority themes of R&D are mentioned with thin film SRF mentioned in both the RF and ERL sections, and the ERL section highlighting the need for further accelerator R&D as well as diagnostics. Furthermore, the studies on diagnostics and thin film SRF are likely to have applications for security and medical accelerators, providing additional societal impact.

Publications

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