Wakefield and Impedance Studies with Ultra-Relativistic Beams for CLARA and UK FEL

CLARA 和 UK FEL 的超相对论光束韦克菲尔德和阻抗研究

• 批准号: 1962251
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1962251
• 关键词: Wakefield; Impedance; Studies; Ultra; Relativistic

The CLARA accelerator at Daresbury is designed to accelerate very short bunches of electrons, with a charge of 250 pC, to an energy of 250 MeV. These bunches, femto second in length, are sensitive to wakefields generated by transitions in various components in the overall accelerator -such as bellows, bends, and other transitions and obstacles. The Fourier transform of this wakefields constitute the beam impedance. This, and the corresponding wakefield excited by ultra-relativistic beams, will be measured with bench-top measurement techniques, and with beam-based measurements at VELA/CLARA in the UK and on CALFIFES at CERN. Sophisticated analytical techniques and a suite of simulations will also be employed to characterise both the wakefield and the beam dynamics. The purpose of this research will be to analyse a multitude of components in the CLARA accelerator, characterise the wakefield both from analytical models, where appropriate, numerical simulation, and bench top measurements. Several novel analytical methods will be employed to gain an understanding of the general behaviour of wakefields associated with these accelerator components. This will have direct application to the CLARA facility, and UK-FEL. This project is a crossover between physics and engineering. The physics aspect involves studying the fundamental wakefield aspects of the CLARA accelerator -and their interaction with the beam through advanced beam dynamics simulations. The engineering component is concerned with assessing the wakefield and impedance associated with each component and suggesting amelioration techniques where appropriate. We anticipate collaboration with CERN colleagues on the CALIFES facility in particular. A similar characterisation has been applied to components in the LHC accelerator -resulting in an impedance budget which allowed the upgrade phase to proceed. This project will necessarily entail a strong coupling between rf and beam dynamics -in which the beam impedance of components will be characterised and the implications on the beam assessed with analytical models and intense beam dynamics simulations.

达斯伯里的 CLARA 加速器旨在将电荷为 250 pC 的非常短的电子束加速到 250 MeV 的能量。这些束的长度为飞秒级，对整个加速器中各个组件（例如波纹管、弯曲以及其他过渡和障碍物）中的过渡产生的尾场敏感。该尾场的傅里叶变换构成了光束阻抗。这个以及由超相对论光束激发的相应尾场将通过台式测量技术以及在英国的 VELA/CLARA 和欧洲核子研究中心的 CALFIFES 上进行基于光束的测量进行测量。复杂的分析技术和一套模拟也将用于表征尾流场和光束动力学。这项研究的目的是分析 CLARA 加速器中的多个组件，通过分析模型、数值模拟和台式测量来表征尾场。将采用几种新颖的分析方法来了解与这些加速器组件相关的尾场的一般行为。这将直接应用于 CLARA 设施和 UK-FEL。该项目是物理学和工程学的交叉项目。物理方面涉及研究 CLARA 加速器的基本尾场方面，以及通过先进的束流动力学模拟它们与束流的相互作用。工程部分涉及评估与每个组件相关的尾流场和阻抗，并在适当的情况下提出改进技术。我们特别期待与 CERN 同事在 CALIFES 设施上进行合作。类似的表征已应用于大型强子对撞机加速器中的组件，从而产生阻抗预算，从而允许升级阶段继续进行。 该项目必然需要射频和光束动力学之间的强耦合，其中将表征组件的光束阻抗，并通过分析模型和强烈的光束动力学模拟评估对光束的影响。