Frontier Experiments in Dynamic Extreme Conditions: The Case for Light Elements

国家、研究委员会和跨国财团正在大力投资于极端能量密度条件下的物质研究。拥有强大光学激光器、自由电子X射线激光器和脉冲电力的大型实验室迅速扩大了材料中可达到的压力和温度极限，探索了系外行星内部深处等自然奇观，追求了受控聚变等新技术，并探索了极端情况下物质的基本行为。然而，这样的设施是罕见的，访问往往是排他性的，限制了这个世纪物理学前沿的增长。该项目建议开发和应用新的桌面方法来创建以前只能在体育场大小的实验室中合成的物质状态，或者以前从未合成过。这项工作使用传统方法的新组合，将彻底改变极端条件的使用，特别是对于水和氢等轻元素材料，实现和研究极端条件的挑战尤为突出。与此同时，轻元素及其组成材料的高压和高温行为在从惯性约束聚变反应堆到巨行星和恒星的极端系统中至关重要。轻元素也包括从氢分子到水，再到生命的基本分子构建块的原型物理系统。许多关于此类材料行为的最基本问题都存在于极端条件下，许多最实用的问题也是如此。这项研究将克服现有的限制，研究轻元素在极端使用手持仪器-金刚石砧单元-压缩样品到高密度，然后快速加热和探测现代光学和X射线方法。这些技术价格低廉，基于广泛使用的仪器，将使对极端条件研究感兴趣的大型科学界能够接触到轻元素材料中的极端状态。

Nations, research councils, and multinational consortia are investing heavily in the study of matter under conditions of extreme energy density. Large laboratories with powerful optical lasers, free-electron x-ray lasers, and pulsed electrical power have rapidly expanded the extremes of pressure and temperature accessible in materials, exploring natural wonders such as exoplanets' deep interiors, pursuing new technologies such as controlled fusion, and probing the fundamental behaviour of matter at extremes. However, such facilities are rare and access often exclusive, limiting growth in this 21st century physics frontier. This project proposes to develop and apply novel table-top approaches to creating states of matter previously synthesised only in stadium-sized laboratories, or which have never before been synthesised. Using a novel combination of traditional approaches, this work will revolutionise access to extreme conditions, particularly for light elemental materials such as water and hydrogen, for which the challenge of achieving and studying extreme conditions has been particularly pronounced. At the same time, the high-pressure and high-temperature behaviour of light elements and the materials they comprise are critically important in extreme systems ranging from inertial confinement fusion reactors to giant planets and stars. Light elements also comprise archetypal physical systems ranging from the hydrogen molecule, to water, to the basic molecular building blocks of life. Many of the most fundamental questions about the behaviour of such materials lie at extreme conditions, as do many of the most practical ones. This study will overcome existing limitations in studying light elements at extremes using a handheld instrument - the diamond anvil cell - to compress samples to high density, followed by rapid heating and probing by modern optical and x-ray methods. Inexpensive and based on a widely-used instrument, the techniques developed will extend access to very extreme states in light elemental materials to the large scientific community interested in extreme conditions research.