The DiPOLE Laser on the Helmholtz Beamline at XFEL

XFEL 亥姆霍兹光束线上的偶极激光器

• 批准号: EP/M000508/1
• 负责人: Ian Walmsley
• 金额: $ 18.53万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FM000508%2F1
• 关键词: DiPOLE; Laser; Helmholtz; Beamline; XFEL

X-rays are a form of electromagnetic radiation with wavelengths shorter than the distance between atoms in a solid, thus they can be used to 'view' matter on atomic dimensions. Over the past few years there has been a revolution in x-ray science: ultra-short pulses of laser-like x-rays can now be produced durations less than a tenth of a trillionth of a second, which is also the sort of time it takes for atoms to move back and forth as they vibrate within a solid. This ultra-bright X-ray laser thus allows us to make stroboscopic 'movies' of matter without motional blurring. The first x-ray laser to be built was in the US, at Stanford, using a 50-year old accelerator. The European version, under construction in Hamburg, is being built from scratch, and as such is based on novel superconducting magnet technology that means it will produce x-ray pulses at a rate several 100 times faster than that of the US system - producing another leap forward in technology. The proposal here is a request for equipment for a UK consortium of 10 leading Universities to help build one of the diagnostic end-stations on this European X-ray Free-Electron Laser (XFEL). The equipment is a very intense optical laser to go alongside the XFEL , allowing matter to first be irradiated by the intense optical beam, and then probed with the unique x-ray beam. This optical/x-ray combination will allow a whole range of different types of research to be performed. For example, when a sample is irradiated with intense optical light, the surface is heated to such high temperatures that a plasma forms. This plasma expands into the vacuum (the experiments are all performed without air), and the reaction force compresses the rest of the target to high pressures - greater than those found at the centre of Jupiter. These conditions exist for about a billionth of a second, before the target falls apart, but in that short time the XFEL (accurately synchronized to the optical laser) scatters from the atoms in the target, and the recorded signal shows their arrangement. In this way, we can discover the conditions that occur at the centre of the giant planets in our own solar system, and also start to explore the types of material that may exist inside the numerous exoplanets that have been discovered (now close to 1000 have been confirmed). This optical/x-ray laser combination makes possible many other types of experiments - for example the x-ray laser itself can heat a solid to several million degrees (it is sobering to realize that these sort of conditions - say a gram per centimeter cubed, and 2 million degrees, are exactly those predicted to exist half way to the centre of the sun). Furthermore, the optical laser can be configured with other lasers to produce very intense light - so intense that electrons within the electric field of the light are accelerated themselves to such high velocities that their mass is altered by Einstein's relativistic equations. As the electrons are flung back and forth, they experience huge accelerations, and it has been predicted that x-rays scattering from them, produced by the XFEL, will allow models of quantum gravity to be explored in the laboratory. These high power lasers can also be used to accelerate particles (electrons or protons) to very high energies, making compact acclerators - but some of the mechanisms involved are not fully understood - mainly because we cannot 'see' inside the target where the particles are produced. The X-ray laser will allow such probing of the target, and thus the aim is to make better compact accelerators that could be used either for fundamental research, or in medical applications, such as the treatment of cancer. It can thus be seen that the experiments that this XEL machine, in combination with the optical laser requested here, is very wide ranging, with implications across a spectrum of disciplines where UK scientists have considerable leadership and expertise.

X射线是电磁辐射的一种形式，其波长比固体中原子之间的距离短，因此它们可用于在原子维度上“观察”物质。在过去的几年里，X 射线科学发生了一场革命：现在可以产生类似激光的 X 射线超短脉冲，持续时间小于十分之一万亿分之一秒，这也是一种时间当原子在固体内振动时，它们需要来回移动。因此，这种超亮 X 射线激光使我们能够制作物质的频闪“电影”，而不会产生运动模糊。第一个 X 射线激光器是在美国斯坦福大学建造的，使用的是已有 50 年历史的加速器。正在汉堡建造的欧洲版本是从头开始建造的，因此基于新颖的超导磁体技术，这意味着它将以比美国系统快 100 倍的速度产生 X 射线脉冲 - 产生另一个技术的飞跃。这里的提案是向由 10 所顶尖大学组成的英国联盟提供设备请求，以帮助在欧洲 X 射线自由电子激光器 (XFEL) 上构建诊断终端站之一。该设备是一个非常强的光学激光器，与 XFEL 一起使用，使物质首先受到强光束的照射，然后用独特的 X 射线束进行探测。这种光学/X 射线组合将允许进行一系列不同类型的研究。例如，当样品受到强光照射时，表面会被加热到很高的温度，从而形成等离子体。这种等离子体膨胀到真空中（实验都是在没有空气的情况下进行的），反作用力将目标的其余部分压缩到高压 - 比木星中心发现的压力更大。这些条件存在大约十亿分之一秒，然后目标就会崩溃，但在这段时间内，XFEL（与光学激光精确同步）从目标中的原子散射，记录的信号显示了它们的排列。通过这种方式，我们可以发现太阳系巨行星中心的情况，也可以开始探索已发现的众多系外行星（现已接近 1000 颗）内部可能存在的物质类型。已确认）。这种光学/X 射线激光组合使许多其他类型的实验成为可能 - 例如，X 射线激光本身可以将固体加热到几百万度（令人清醒地认识到这些条件 - 比如说每立方厘米一克）和 200 万度，正是预测存在于太阳中心一半位置的温度）。此外，光学激光器可以与其他激光器一起配置，以产生非常强的光——强度如此之大，以至于光电场内的电子自身被加速到如此高的速度，以至于它们的质量被爱因斯坦的相对论方程所改变。当电子来回抛射时，它们会经历巨大的加速度，据预测，XFEL 产生的电子散射 X 射线将允许在实验室中探索量子引力模型。这些高功率激光器还可用于将粒子（电子或质子）加速到非常高的能量，从而制造紧凑的加速器 - 但其中涉及的一些机制尚未完全了解 - 主要是因为我们无法“看到”目标内部粒子所在的位置产生的。 X射线激光器将允许对目标进行此类探测，因此目标是制造更好的紧凑型加速器，可用于基础研究或医学应用，例如癌症治疗。由此可见，该 XEL 机器与此处要求的光学激光器相结合的实验范围非常广泛，对英国科学家拥有相当领导力和专业知识的一系列学科都有影响。

项目成果

Development of a 100 J, 10 Hz laser for compression experiments at the High Energy Density instrument at the European XFEL

开发 100 J、10 Hz 激光器，用于欧洲 XFEL 高能量密度仪器的压缩实验

• DOI: 10.1017/hpl.2018.56
• 发表时间: 2018-12-27
• 期刊: High Power Laser Science and Engineering
• 影响因子: 4.8
• 作者: P. Mason;S. Banerjee;Jodie M. Smith;T. Butcher;Jonathan Phillips;H. Höppner;D. Möller;K. Ertel;M. De Vido;Ian Hollingham;A. Norton;S. Tomlinson;Tinesimba Zata;J. S. Merchan;C. Hooker;M. Tyldesley;T. Toncian;C. Hern;ez;ez;C. Edwards;J. Collier
• 通讯作者: J. Collier