Enhancing ERL development in the UK

能量回收直线机（ERLs）有潜力支持未来高能物理实验的物理范围，因为它允许以适度的射频功耗产生高功率电子束。这是通过提取消耗的束的动能来实现的，通过减速并使用这些能量来加速新的束，从而大大降低了加速器的总体功耗。多转erl对于以经济有效的方式将电子加速到10s GeV尤为重要。erl被视为未来高强度轻强子对撞机（FCC-eh, LHeC， EIC）和FEL设施（UK-XFEL）的使能技术。在接下来的4-5年中，预计国际ERL社区将开始相关技术和测试设施的原型设计。该提案的主要目的是保持英国在与erl相关的加速器研发方面的国际领先地位。超导射频（SRF）技术是ERL运行的关键技术，高输出功率要求发展机器保护和相关诊断技术。最后，波束线设计，包括拓扑结构和机器中新旧束在多个转弯上的交错——被称为填充模式——是一个重要的新研究领域，因为最近英国的研究表明，使用优化的束线模式可以显著提高性能。科克罗夫特研究所在所有这些领域都拥有世界领先的专业知识，因此将这些领域确定为高度优先领域。因此，在这个项目中进行的研究将解决这些领域，以提高英国的持续领导地位。PPTAP的英国加速器研发路线图将突出erl的潜在社会应用，这些应用可能发生在比未来对撞机所需的规模更小的设施上。特别感兴趣的是那些在光源，即通过反康普顿散射驱动的单能伽马源，以及具有协同作用的高平均功率自由电子激光器英国- xfel。解决这些问题的中等规模ERL设施也可以成为及时部署未来对撞机项目所需的关键技术的平台。在这个路线图中，所有三个高优先级的研发主题都被提及，在RF和ERL部分都提到了薄膜SRF， ERL部分强调了进一步的加速器研发和诊断的必要性。此外，关于诊断和薄膜SRF的研究可能会应用于安全和医疗加速器，提供额外的社会影响。

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.