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; 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射线是一种电磁辐射的一种形式，其波长短于固体中原子之间的距离，因此它们可用于在原子尺寸上“查看”物质。在过去的几年中，X射线科学发生了一场革命：类似激光的X射线的超短脉冲现在可以产生不到一秒钟的十分之一一秒钟的时间，这也是原子在固体中振动时来回移动所花费的时间。因此，这种超光亮的X射线激光器使我们能够在不模糊的情况下制作物质的“电影”。使用50年历史的加速器的第一个X射线激光器是在斯坦福大学在美国建造的。汉堡正在建造的欧洲版本正在从头开始建造，因此基于新颖的超导磁铁技术，这意味着它将以比美国系统快的速度快几百倍的速度生产X射线脉冲 - 在技术方面产生了另一个飞跃。此处的提案是为十所主要大学的英国财团提供设备，以帮助建立此欧洲X射线自由电子激光器（XFEL）上的诊断终点之一。该设备是一种非常强烈的光学激光器，可以与XFEL一起进行，因此首先可以用强烈的光束照射物质，然后用​​独特的X射线梁进行探测。这种光学/X射线组合将允许进行各种不同类型的研究。例如，当样品用强烈的光学光照射时，将表面加热到等离子体形成的高温。该等离子体扩展到真空中（实验都没有空气执行），并且反作用力压缩目标的其余部分到高压 - 大于木星中心的压力。在目标崩溃之前，这些条件存在约十亿个一秒钟，但是在短时间内XFEL（准确地与光学激光同步）从目标中的原子散射，并且记录的信号显示其排列。通过这种方式，我们可以在我们自己的太阳系中发现在巨型行星中心发生的条件，并开始探索已发现的众多系外行星内可能存在的材料类型（现在已经确认了1000个）。这种光学/X射线激光器组合使许多其他类型的实验可能成为可能 - 例如，X射线激光器本身可以将实心加热至数百万度（令人震惊的是，意识到这类条件是这样的条件 - 例如，每克立方体，有200万度，这些条件完全存在于阳光中心的一半）。此外，可以与其他激光器配置光学激光器以产生非常强烈的光 - 如此强烈，以至于光场中的电子被加速到如此高的速度，以至于爱因斯坦的相对方程将其质量改变。随着电子的来回扑打，它们会经历巨大的加速度，并且已经预测，XFEL产生的X射线散射将允许在实验室中探索量子重力模型。这些高功率激光器也可以用来将颗粒（电子或质子）加速到非常高的能量，使其产生紧凑的acclerator，但是涉及的某些机制尚未完全理解 - 主要是因为我们在产生粒子的目标中无法“看到”目标。 X射线激光器将允许对目标进行探测，因此目的是制造更好的紧凑型加速器，这些加速器可用于基础研究或医疗应用，例如治疗癌症。因此，可以看出，这款Xel机器与此处要求的光学激光相结合的实验非常广泛，在英国科学家具有相当大的领导力和专业知识的一系列学科中的影响。