X-ray Studies of Exotic Novel States of Solid-Density Matter Created with 4th Generation Light Sources

用第四代光源产生的固体密度物质的奇异新状态的 X 射线研究

• 批准号: EP/H035877/1
• 负责人: Justin Wark
• 金额: $ 92.98万
• 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: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FH035877%2F1
• 关键词: ray; Studies; Exotic; Novel; States

Over the past year or so there has been a revolution in X-ray science, in that new sources of soft and hard X-rays have been developed that are ten billion times brighter than those produced by synchrotrons. These novel sources emit extremely short (sub 100fsec) pulses of x-rays, and can be focussed to very small spots. As the pulses are so short, the power in the light is enormous - for the brief duration of the emission the power in the light is equivalent to that in a fair-sized electrical power station. When all this power is focussed to a small spot, enormous intensities of x-rays impinge upon the target in its path - intensities that have hitherto never been produced in the X-ray regime. In the last few months we have performed some of the first experiments aimed at understanding how matter reacts to such intense X-ray light, and the aim of this proposal is to vastly further that understanding. What we have already found is that the intensity is so great that an electron from every atom in the target can be knocked out by the X-rays, and this can alter the X-ray properties of the material itself - indeed, by this method we have made a so-called saturable absorber. What is of fundamental interest to us is that as the electrons re-fill the core holes, they provide information about the electronic structure of this exotic and highly-ionized state, providing completely new insight into the physics of very dense, yet very hot material. This material (warm dense matter) is of interest in that the thermal energies and electronic energies (the coulomb potential) are comparable, making its properties extremely difficult to calclulate. This situation - where the thermal and coulombic energies compete - also occurs in the initial stages of inertial confinement fusion, and is also part of the physics that is relevant to the understanding of the interior of the giant planets - thus there are many reasons for wishing to understand it better. The intense X-rays give a unique opportunity to understand such matter, as within femtoseconds they make a particular state - very hot electrons but cold ions, at a well defined density. Watching this state evolve ( by looking at the fluorescence, and monitoring the absorption as a function of time) gives detailed information on the electronic structure. For example, with highly ionized aluminium, we have an unusual situation at the highest intensities where a particular aluminium ion that undergoes recombination is now doing so with neighbours that themselves are still ionized. This drastically alters the shape of the fluorescence emission in a way which has much to do with how the fluorescence signal from an alloy is altered as the compound composition changes. Thus this research will provide unique insight into the electronic structure of matter at hundreds of thousands of degrees kelvin, yet still at solid density.

在过去的一年左右的时间里，X射线科学发生了一场革命，因为已经开发出的柔软和硬X射线来源比同步基因生产的X射线射线更明亮。这些新来的来源散发出极短的X射线脉冲（sub 100fsec）脉冲，并且可以集中在很小的斑点上。由于脉冲太短，因此光线中的功率很大 - 在发射的短暂持续时间内，光线中的功率等同于在公平的电力站中。当所有这些功率都集中在一个很小的位置时，X射线的巨大强度会撞击目标的路径 - 迄今未在X射线制度中从未产生的强度。在过去的几个月中，我们进行了一些旨在了解物质对这种强烈X射线光的反应的第一个实验，该提议的目的是进一步进一步理解。我们已经发现的是，强度是如此之大，以至于X射线可以将目标中每个原子的电子拆除，这可以改变材料本身的X射线特性 - 实际上，通过这种方法，我们制造了所谓的饱和吸收仪。我们根本兴趣的是，随着电子的重新填充核心孔，它们提供了有关这种异国情调和高度离子状态的电子结构的信息，从而为非常密集但非常热的物质物理学提供了全新的见解。这种材料（温暖的物质）令人感兴趣，因为热能和电子能（库仑电势）是可比的，因此其性能极为难以加压。这种情况（热能量和库仑能竞争）也发生在惯性限制融合的最初阶段，并且也是与理解巨型行星内部理解相关的物理学的一部分，因此有许多理由希望更好地理解它。强烈的X射线为理解此类问题提供了独特的机会，因为在飞秒内它们是一种特定的状态 - 非常热的电子，但冷离子的密度良好。观察这种状态的发展（通过查看荧光并监测吸收随时间的函数）提供了有关电子结构的详细信息。例如，使用高度电离的铝，我们在最高强度的情况下存在异常情况，在这种情况下，经历重组的特定铝离子现在正在与邻居本身保持电离。这大大改变了荧光发射的形状，这与合金的荧光信号的变化有很大关系，随着化合物的变化而变化。因此，这项研究将为数十万度开尔文的物质电子结构提供独特的见解，但仍处于固体密度。

项目成果

Observation of Reverse Saturable Absorption of an X-ray Laser

X 射线激光反向饱和吸收的观察

• DOI: 10.3204/pubdb-2017-13877
• 发表时间: 2017
• 作者: Cho B

Simultaneous diagnosis of radial profiles and mix in NIF ignition-scale implosions via X-ray spectroscopy

通过 X 射线光谱同时诊断 NIF 点火级内爆中的径向分布和混合

• DOI: 10.1063/1.5000774
• 发表时间: 2017
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: Ciricosta O

Measurements of continuum lowering in solid-density plasmas created from elements and compounds.

• DOI: 10.1038/ncomms11713
• 发表时间: 2016-05-23
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Ciricosta O;Vinko SM;Barbrel B;Rackstraw DS;Preston TR;Burian T;Chalupský J;Cho BI;Chung HK;Dakovski GL;Engelhorn K;Hájková V;Heimann P;Holmes M;Juha L;Krzywinski J;Lee RW;Toleikis S;Turner JJ;Zastrau U;Wark JS
• 通讯作者: Wark JS

Detailed model for hot-dense aluminum plasmas generated by an x-ray free electron laser

• DOI: 10.1063/1.4942540
• 发表时间: 2016-02-01
• 期刊: PHYSICS OF PLASMAS
• 影响因子: 2.2
• 作者: Ciricosta, O.;Vinko, S. M.;Wark, J. S.
• 通讯作者: Wark, J. S.

Simulations of neon irradiated by intense X-ray laser radiation

• DOI: 10.1016/j.hedp.2011.02.003
• 发表时间: 2011-09-01
• 期刊: HIGH ENERGY DENSITY PHYSICS
• 影响因子: 1.6
• 作者: Ciricosta, Orlando;Chung, Hyun-Kyung;Wark, Justin S.
• 通讯作者: Wark, Justin S.