The Creation and Diagnosis of Solid-State Matter at Multi-TeraPascal Pressures

我们的目标是利用我们在激光诱导动态压缩和X射线衍射方面的专业知识，利用美国的Janus、omega和国家点火设施(NIF)激光平台，首次对1 Tpa(10兆巴)以上的固体物质进行结构研究。在这样的压力下，压缩能量足以打破所有的化学键，提供了一个预计会发生新的物理和化学的区域。通过开发优化的目标设计和X射线衍射设备，我们将收集纳秒时间尺度上的高质量衍射数据，并在理论和计算的辅助下，确定一些基本材料的结构和相变，以达到3 Tpa的上限压力-几乎是使用静态压缩技术所能达到的最大压力的10倍。我们计划将这些进展应用于(1)碳(钻石)到3TPA的结构和跃迁的研究，寻找到金属BC8相的跃迁，以及在常压下碳的超硬亚稳态相的产生；(2)研究‘简单’金属Na和Li到3TPA的研究，寻找金属-绝缘体和绝缘体-金属的跃迁，以及价电子和邻近原子上的核心被迫重叠的电子结构类型的出现；以及(3)高压缩时零点能相对增强导致锂的“冷熔化”和液态基态开始的研究。

We aim to exploit our expertise in laser-induced dynamic compression and x-ray diffraction to make the first ever structural studies of solid matter above 1 TPa (10 megabars) using the JANUS, OMEGA, and National Ignition Facility (NIF) laser platforms in the US. At such pressures, the compression energy is sufficient to break all chemical bonds, providing a regime where new physics and chemistry are predicted to occur. By developing optimised target designs and x-ray diffraction facilities, we will collect high-quality diffraction data on nano-second timescales, and, aided by theory and computation, will determine the structures and phase transitions in a number of fundamental materials to an upper pressure of 3 TPa - almost 10 times higher than the maximum pressure attainable using static compression techniques. We plan to apply these developments to (1) studies of the structures and transitions in carbon (diamond) to 3 TPa, searching for transitions to the metallic BC8 phase, and the creation of super-hard metastable phases of carbon at ambient pressure; (2) studies of the 'simple' metals Na and Li to 3 TPa, searching for metal-insulator and insulator-metal transitions, and the appearance of electride structure-types as valence electrons and cores on neighbouring atoms are forced to overlap; and (3) studies of the onset of "cold-melting" and a liquid ground-state in lithium as a result of the relative enhancement of the zero-point energy at high compression.