Terahertz driven dielectric linacs

太赫兹驱动介电直线加速器

• 批准号: ST/N003063/1
• 负责人: Graeme Burt
• 金额: $ 3.43万
• 依托单位: Lancaster University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FN003063%2F1
• 关键词: Terahertz; driven; dielectric; linacs

In particle physics, future linear colliders such as CLIC or ILC require ultra-short, sub-picosecond, bunches to obtain the luminosity necessary for the particle physics science exploration. In accelerator based X-Ray sources, sub 10fs bunches are highly sought after, opening new windows on material science. Going beyond these massive accelerators will require higher gradient structures to shrink the size and cost of future high energy colliders. Current metallic microwave structures are limited by electric breakdown to around 100 MV/m.In the drive to obtain every shorter particle bunches, the synchronization of the bunches, both to each other and to facility infrastructure (RF, drive lasers, facility clocks, diagnostic systems) is crucial for the facility optimization, and yet continues to present unsolved problems. Both generation and synchronization of such ultra-short particle beams presents a subsequent problem for the measurement of the ultra-short bunches; only two technologies exist that approach the requirements of future linear colliders and accelerator light sources; laser based 'electro-optic' detection and transverse deflecting cavities. However, EO detection is not currently able to address the few-fs regime, while the gradient requirements make RF (Transverse deflecting cavity) TDC's infeasible for sub-ps measurements on high energy particle physics machines. A high gradient, high frequency (>300 GHz) TDC would allow the same technique to be applied to ultra-short, high energy colliders.Here we propose to develop a blue-skies approach to these problems, using laser generated THz radiation to be coupled to dielectric lined waveguide for acceleration and manipulation of those beams. In extending the GHz-RF techniques into the picosecond/THz regime we gain in time resolution for manipulation and detection; we gain orders of magnitude in the temporal gradient necessary for manipulation on the sub-picosecond time scale; we gain orders of magnitude in energy efficiency, through only generating the accelerating and deflecting fields over a time window matched to the beams to be accelerated (rather than matched to microsecond cavity filling times). Similar high profile research at Stanford has demonstrated gradients in excess of 250 MV/m using laser pulses at much shorter wavelengths. The short timescales involved and the lack of metallic-vacuum transitions prevents the breakdown in the structure up to the dielectric strength of the lining or grating. However in contrast to a wide body of research into optical acceleration methods, the THz approach allows complete trapping of 'conventional' picosecond bunches rather than the high frequency optical smearing associated with the <3fs periods of laser-acceleration concepts. By using THz the electron bunch can occupy a small range of phases producing a far higher quality bunch consistent with requirements from accelerator applications such as colliders and FELs. One of the first steps towards this goal is the demonstration of laser-based schemes for the acceleration and deflection of relativistic electron beams. We propose to take preliminary simulations and experiments to the next stage of proof-of-concept demonstration on STFC's test accelerator, VELA. Our approach is a melding of concepts in electro-optic detection and THz generation (areas of expertise for Jamison and Graham) and particle physics cavity design (expertise of Burt). By using an integrated team the structure and source can be developed in tandem to provide a technology ideally suited to accelerator development. While other experiments have taken place with sub-relativistic particles this would be the first acceleration of fully relativistic particles by a THz structure and would be the first transverse deflecting cavity operating in the THz regime.

在粒子物理学中，诸如CLIC或ILC之类的未来线性壁物需要超短，次秒束，以获得粒子物理科学探索所需的亮度。在基于加速器的X射线源中，备受追捧的10FS束，打开了有关材料科学的新窗口。超越这些庞大的加速器将需要更高的梯度结构来缩小未来高能量攻针的大小和成本。当前的金属微波结构受到电力崩溃的限制至约100 mV/M.在获得所有较短的粒子束的动力，彼此之间的同步和设施基础设施（RF，驱动激光，设施，设施，设施钟，诊断系统）对于设施的最佳问题至关重要。这种超短颗粒梁的产生和同步都提出了测量超短束的后续问题。仅存在两种技术，即未来的线性相撞器和加速器光源的要求；基于激光的“电孔”检测和横向偏转腔。但是，EO检测目前无法解决几个FS制度，而梯度需求使RF（横向偏转腔）TDC不可避免地用于高能粒子物理机器的子PS测量。高梯度高频（> 300 GHz）TDC将允许将相同的技术应用于超短距离的高能量山脉。在将GHz-RF技术扩展到Picsecond/THz策略中，我们可以在时间分辨率上进行操作和检测；我们获得了在亚皮秒时间尺度上操纵所需的时间梯度的数量级。我们仅通过在与光束相匹配的时间窗口中生成加速和偏转字段来获得能源效率的数量级（而不是与微秒的空腔填充时间匹配）。在斯坦福大学的类似知名研究表明，使用激光脉冲在短较短的波长下，梯度超过250 mV/m。涉及的短时间尺寸和缺乏金属效量的过渡可以防止结构的崩溃，直到衬里或光栅的介电强度。但是，与对光学加速方法的广泛研究相反，THZ方法允许完全捕获“常规”皮秒束，而不是与激光加速概念相关的高频光学涂抹。通过使用THZ，电子束可以占据一小范围的相位，从而产生质量更高的质量，符合加速器应用（例如山脉和Fels）的要求。实现此目标的第一步之一是基于激光的方案，用于加速和偏转相对论电子束。我们建议对STFC测试加速器Vela进行初步模拟和实验进行初步概念验证演示。我们的方法是融合了电语检测和THZ产生（Jamison和Graham的专业知识领域）和粒子物理腔设计（Burt的专业知识）中的概念。通过使用集成团队，可以同时开发结构和来源，以提供一项非常适合加速器开发的技术。虽然其他实验是使用亚偏见粒子进行的，但这将是通过THZ结构的第一个完全相对论粒子的加速度，并且是在THZ制度中运行的第一个横向偏转腔。

项目成果

Characterizing a terahertz-driven dielectric-lined waveguide for electron beam manipulation

• DOI: 10.1109/irmmw-thz.2018.8509912
• 发表时间: 2018-09
• 期刊: 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)
• 作者: V. Georgiadis;A. Healy;M. Hibberd;G. Burt;S. Jamison;D. Graham

Electron-terahertz interaction in dielectric-lined waveguide structures for electron manipulation

用于电子操纵的电介质衬里波导结构中的电子-太赫兹相互作用

• DOI: 10.1016/j.nima.2018.02.025
• 发表时间: 2018
• 期刊: Accelerators, Spectrometers, Detectors and Associated Equipment
• 作者: Healy A

Dispersion in dielectric-lined waveguides designed for terahertz-driven deflection of electron beams

• DOI: 10.1063/5.0041391
• 发表时间: 2021-04
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: V. Georgiadis;A. Healy;M. Hibberd;G. Burt;S. Jamison;D. Graham

Terahertz-driven acceleration of a relativistic 35 MeV electron beam

• DOI: 10.1109/irmmw-thz.2019.8873990
• 发表时间: 2019-10
• 期刊: 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)
• 作者: M. Hibberd;A. Healy;D. Lake;V. Georgiadis;E. J. H. Smith;O. Finlay;T. Pacey;J. Jones;Y. Saveliev;D. Walsh;E. Snedden;R. Appleby;G. Burt;D. Graham;S. Jamison

Group Velocity Matching in Dielectric-Lined Waveguides and its Role in Electron-THz Interaction

介质衬里波导中的群速度匹配及其在电子-太赫兹相互作用中的作用

• DOI: 10.18429/jacow-ipac2017-wepva019
• 发表时间: 2017
• 作者: Healy Alisa