Harnessing laser-driven plasma waves as particle and radiation sources

我们建议在Alpha-X项目成功的基础上，通过一个新的研究计划来研究和开发明确利用激光驱动的等离子体波的新型紧凑型辐射源。该项目将推动尾波场加速器的发展，并利用在等离子体通道中加速的亚10飞秒电子束，在自由电子激光和相干辐射体结构中产生相干红外到X射线辐射的超短脉冲。主要目标将是通过利用等离子体波的非常短的空间周期波动类结构来推动硬X射线和伽马射线的发展，为迄今无法进入的光谱区域的源奠定基础。我们还将推动超短脉冲产生的前沿：i)使用预聚束技术控制和缩短来自尾波场加速器的电子束持续时间，这也将增加可用的峰值电流，同时减少来自辐射源的脉冲长度；以及ii)研究通过从相对论等离子体尾迹和电离前沿形成的相对论反射镜反向散射定制的太赫兹脉冲来产生和定制任意形状的单周期脉冲(最初是可见的)。开发这些新型紧凑型辐射源的实验计划将利用根据阿尔法-X项目在斯特拉斯克莱德建立的独特设施，以及欧盟、美国和中国提供的资源，提供长期发展计划和短期(6周)活动的组合，利用这些设施提供的特殊激光特性。该项目的一个重要方面将是一个实质性的理论方案，将由一个以前在Alpha-X下共同工作的成熟的理论家团队和新的团队负责，这些团队将带来新的方法和背景，以应对重大的理论挑战。一大批合作伙伴为方案提供了广度和深度，通过他们的贡献和利用他们的各种设施，也将使资源得到非常有效的利用。该研究计划是英国路线图的核心，该路线图勾勒出该领域潜在的新前景和前进方向。

We propose to build on the successes of the ALPHA-X project with a new programme of research to investigate and develop novel compact radiation sources that explicitly exploit laser-driven plasma waves. The project will take forward the development of wakefield accelerators and utilise the sub-10 fs electron bunches accelerated in plasma channels to produce ultra-short pulses of coherent infrared to x-ray radiation in a FEL and coherent radiator structures. The main objective will be to push towards hard x-rays and gamma rays by utilising the very short spatial period undulator-like structures of plasma waves to lay down the foundations of sources in a spectral region hitherto not accessible. We will also push the frontiers of ultra-short pulse generation by: i) controlling and reducing the electron bunch duration from wakefield accelerators using pre-bunching techniques, which will also increase the peak current available while reducing the pulse length from a radiation source, and by ii) investigating the generation and tailoring of arbitrary shaped single-cycle pulses (initially in the visible) by backscattering tailored terahertz pulses from relativistic mirrors formed by relativistic plasma wakes and ionisation fronts. The experimental programme to develop these novel compact radiation sources will utilise the unique facilities at Strathclyde, set up under the ALPHA-X project, and resources available in the EU, US and China, to provide a mix of long-term development programmes and short-term (6-week) campaigns that take advantage of the particular laser beam characteristics available at the facilities. An important aspect of the project will be a substantial theoretical programme that will be undertaken by an established team of theoreticians that has previously worked together under ALPHA-X, and new teams that bring new approaches and backgrounds to bear on the significant theoretical challenges. The large group of collaborators provide both breadth and depth to the programme, and through their contributions and access to their various facilities, will also enable very effective use of resources. The programme of research is central to a UK roadmap that outlines potential new landscapes and ways forward in the field.