AWAKE: a proton-driven plasma wakefield acceleration experiment at CERN

AWAKE：欧洲核子研究中心的质子驱动等离子体尾场加速实验

• 批准号: ST/N001613/1
• 负责人: Matthew Wing
• 金额: $ 22.84万
• 依托单位: University College London
• 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%2FN001613%2F1
• 关键词: AWAKE; proton; driven; plasma; wakefield

Over the last fifty years, accelerators of ever increasing energy and size have allowed us to probe the fundamental structure of the physical world. This has culminated in the Large Hadron Collider at CERN, Geneva, a 27-km long accelerator which has discovered the Higgs Boson and is about to embark on searches for new phenomena such as Supersymmetry. Using current accelerator technology, future high energy colliders will be of similar length or even longer. As an alternative, we are pursuing a new technology which would allow a reduction by about a factor of ten in length and hence would be expected to reduce the cost by a significant fraction. The idea presented here is to impact a high-energy proton beam, such as those at CERN, into a plasma. The free, negatively-charged electrons in the plasma are knocked out of their position by the protons, but are then attracted back by the positively-charged ions, creating a high-gradient electric "wakefield" and an oscillating motion is started by the plasma electrons. Experiments have already been carried out impacting lasers or an electron beam onto a plasma and accelerating gradients have been observed which are 1000 times higher than conventional accelerators. Given the much higher initial energy of available proton beams, it is anticipated that the electric fields it creates in a plasma could accelerate electrons in the wakefield up to the teraelectron-volts scale required for a future collider, but in a single stage and with a length of a few km. Such a collider is, however, many years in the future and test experiments are first needed.The AWAKE collaboration will perform a first proof-of-principle experiment at CERN. The experiment will use a high-energy proton beam to impact on a plasma cell of about 10 m and measure the energy change in a bunch of electrons which will travel behind the proton beam. Observing significant energy changes in the electrons would demonstrate the concept of this form of acceleration which has so far only been studied in simulation.The UK has several groups (Central Laser Facilities, Cockcroft Institute, Imperial College, John Adams Institute, Strathclyde and UCL) in the collaboration preparing the AWAKE experiment in CERN. We propose a programme to develop a wide-range of instrumentation which will the allow us to successfully build the experiment and extract the physics necessary to demonstrate the power of this approach. A crucial part is being able to build a plasma cell with a uniform density over lengths much longer than previously tried. We will also deliver elements of the electron source to be fired into the plasma at exactly the right time so as to feel the largest possible accelerating gradient in the wakefield created by the proton beam. To determine the success of the experiment, we will measure the properties of the plasma and the energy and spatial profile of the electron beam after it has been accelerated in the plasma. Finally, our results will improve simulations of plasma wakefields to give us more confidence in our expectations of a larger-scale experiment and help us best optimise its layout and capabilities. If successful, this experiment will lead to a further larger-scale project to accelerate bunches of electrons of small spatial extent with high particle numbers and ultimately a new form of acceleration which could lead to future, energy-frontier particle physics experiments. This technique has the potential to radically alter the frontier of high energy physics with accelerators as performant as currently planned or required, but at a tenth of the length and hence cost. With the significantly larger acceleration gradients and smaller spatial extent, plasma-based accelerator technology could also lead to vastly smaller synchrotron light sources which probe the structure of e.g. proteins and table-top accelerators of lower energy for use in hospitals or industry.

在过去的五十年里，加速器的能量和尺寸不断增加，使我们能够探索物理世界的基本结构。这在日内瓦欧洲核子研究中心的大型强子对撞机中达到了顶峰，这是一个长 27 公里的加速器，它发现了希格斯玻色子，并将开始寻找超对称等新现象。使用当前的加速器技术，未来的高能对撞机将具有相似的长度甚至更长。作为替代方案，我们正在寻求一种新技术，该技术可以将长度减少约十分之一，因此预计可以大幅降低成本。这里提出的想法是将高能质子束（例如欧洲核子研究组织的质子束）撞击等离子体。等离子体中的自由带负电的电子被质子击出其位置，但随后被带正电的离子吸引回来，形成高梯度电“尾场”，并且等离子体开始振荡运动电子。已经进行了将激光或电子束撞击等离子体的实验，并观察到加速梯度比传统加速器高 1000 倍。考虑到可用质子束的初始能量要高得多，预计它在等离子体中产生的电场可以将尾场中的电子加速到未来对撞机所需的太电子伏级，但在单级中并且具有长度几公里。然而，这样的对撞机还需要很多年的时间，首先需要进行测试实验。AWAKE 合作将在欧洲核子研究组织 (CERN) 进行首次原理验证实验。该实验将使用高能质子束撞击约10 m的等离子体电池，并测量在质子束后面行进的一束电子的能量变化。观察电子中显着的能量变化将证明这种形式的加速的概念，迄今为止仅在模拟中进行了研究。英国有几个小组（中央激光设施、科克罗夫特研究所、帝国理工学院、约翰·亚当斯研究所、斯特拉斯克莱德和伦敦大学学院）合作准备欧洲核子研究中心的 AWAKE 实验。我们提出了一个开发各种仪器的计划，这将使我们能够成功地建立实验并提取必要的物理知识来证明这种方法的威力。一个关键部分是能够在比以前尝试的更长的长度上构建密度均匀的等离子体电池。我们还将在正确的时间将电子源的元件发射到等离子体中，以便感受到质子束产生的尾场中最大可能的加速梯度。为了确定实验是否成功，我们将测量等离子体的特性以及电子束在等离子体中加速后的能量和空间分布。最后，我们的结果将改进等离子体尾场的模拟，使我们对更大规模实验的期望更有信心，并帮助我们最好地优化其布局和功能。如果成功，该实验将导致一个更大规模的项目，以高粒子数加速小空间范围的电子束，并最终形成一种新的加速形式，这可能导致未来的能量前沿粒子物理实验。这项技术有可能从根本上改变高能物理的前沿，加速器的性能达到目前计划或要求的水平，但长度和成本只有十分之一。由于加速度梯度明显更大，空间范围更小，基于等离子体的加速器技术还可以产生更小的同步加速器光源，用于探测例如物体的结构。用于医院或工业的蛋白质和低能耗台式加速器。

项目成果

An electron spectrometer for proton driven plasma accelerated electrons at AWAKE: Predicted resolution of energy and emittance measurements

用于质子驱动等离子体加速电子的电子能谱仪 AWAKE：能量和发射率测量的预测分辨率

• DOI: 10.1109/nssmic.2016.8069746
• 发表时间: 2016
• 作者: Deacon L

VHEeP: a very high energy electron-proton collider

• DOI: 10.1140/epjc/s10052-016-4316-1
• 发表时间: 2016-08-17
• 期刊: EUROPEAN PHYSICAL JOURNAL C
• 影响因子: 4.4
• 作者: Caldwell, A.;Wing, M.
• 通讯作者: Wing, M.

AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

• DOI: 10.1016/j.nima.2016.02.026
• 发表时间: 2016-09-01
• 期刊: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
• 影响因子: 1.4
• 作者: Gschwendtner, E.;Adli, E.;Zhang, H.
• 通讯作者: Zhang, H.

Physics case of the very high energy electron-proton collider, VHEeP

极高能电子质子对撞机 VHEeP 的物理案例

• DOI: 10.22323/1.265.0248
• 发表时间: 2016
• 作者: Wing M

Acceleration of electrons in the plasma wakefield of a proton bunch.

• DOI: 10.1038/s41586-018-0485-4
• 发表时间: 2018-09
• 期刊: Nature
• 影响因子: 64.8
• 作者: Adli E;Ahuja A;Apsimon O;Apsimon R;Bachmann AM;Barrientos D;Batsch F;Bauche J;Berglyd Olsen VK;Bernardini M;Bohl T;Bracco C;Braunmüller F;Burt G;Buttenschön B;Caldwell A;Cascella M;Chappell J;Chevallay E;Chung M;Cooke D;Damerau H;Deacon L;Deubner LH;Dexter A;Doebert S;Farmer J;Fedosseev VN;Fiorito R;Fonseca RA;Friebel F;Garolfi L;Gessner S;Gorgisyan I;Gorn AA;Granados E;Grulke O;Gschwendtner E;Hansen J;Helm A;Henderson JR;Hüther M;Ibison M;Jensen L;Jolly S;Keeble F;Kim SY;Kraus F;Li Y;Liu S;Lopes N;Lotov KV;Maricalva Brun L;Martyanov M;Mazzoni S;Medina Godoy D;Minakov VA;Mitchell J;Molendijk JC;Moody JT;Moreira M;Muggli P;Öz E;Pasquino C;Pardons A;Peña Asmus F;Pepitone K;Perera A;Petrenko A;Pitman S;Pukhov A;Rey S;Rieger K;Ruhl H;Schmidt JS;Shalimova IA;Sherwood P;Silva LO;Soby L;Sosedkin AP;Speroni R;Spitsyn RI;Tuev PV;Turner M;Velotti F;Verra L;Verzilov VA;Vieira J;Welsch CP;Williamson B;Wing M;Woolley B;Xia G
• 通讯作者: Xia G