Femtosecond diffraction and dynamic high pressure science
Femtosecond diffraction and dynamic high pressure science
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DOI：
10.1063/5.0089388
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发表时间：
2022-03
影响因子：
3.2
通讯作者：
J. Wark;M. McMahon;J. Eggert
中科院分区：
文献类型：
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作者：
J. Wark;M. McMahon;J. Eggert
高压下的固态物质在整个宇宙中很普遍，通过X射线衍射来了解这种极端条件下的物质结构，已经追求了世纪的大部分时间。迄今为止，通过激光烧蚀动态压缩，结合X射线衍射诊断，可以达到最高压力（2 TPa）[A. Lazicki等人，Nature 589，532-535（2021）]。在过去的十年中，X射线技术取得了显着的进步，新型X射线自由电子激光器（FEL）能够在100 fs以下的时间尺度上产生高质量的单次衍射数据。我们提供了一个简短的历史领域的动态压缩，跨越时的X射线源几乎总是激光等离子体为基础的，目前的国家最先进的衍射功能提供自由电子激光。我们给出了一个概述的物理动态压缩，诊断技术，以及了解压缩率如何影响最终达到的温度的重要性。我们提供了说明性的例子，在自由电子激光设备上进行的实验，开始深入了解材料如何在应变速率，它们的相图，以及可以达到的状态的类型变形。我们强调，使用静态和动态压缩技术观察到的晶相往往存在差异。我们给出了我们对这个快速发展的领域的现状的看法，以及我们如何看待它在近中期的发展。
Solid-state material at high pressure is prevalent throughout the Universe, and an understanding of the structure of matter under such extreme conditions, gleaned from x-ray diffraction, has been pursued for the best part of a century. The highest pressures that can be reached to date (2 TPa) in combination with x-ray diffraction diagnosis have been achieved by dynamic compression via laser ablation [A. Lazicki et al., Nature 589, 532–535 (2021)]. The past decade has witnessed remarkable advances in x-ray technologies, with novel x-ray Free-Electron-Lasers (FELs) affording the capacity to produce high quality single-shot diffraction data on timescales below 100 fs. We provide a brief history of the field of dynamic compression, spanning from when the x-ray sources were almost always laser-plasma based, to the current state-of-the art diffraction capabilities provided by FELs. We give an overview of the physics of dynamic compression, diagnostic techniques, and the importance of understanding how the rate of compression influences the final temperatures reached. We provide illustrative examples of experiments performed on FEL facilities that are starting to give insight into how materials deform at ultrahigh strain rates, their phase diagrams, and the types of states that can be reached. We emphasize that there often appear to be differences in the crystalline phases observed between the use of static and dynamic compression techniques. We give our perspective on both the current state of this rapidly evolving field and some glimpses of how we see it developing in the near-to-medium term.