Renewal: Simple Molecular Systems at Ultrahigh Pressures

*技术摘要*这个项目将在很宽的温度范围内进行压力为400 Gpa(4兆巴)的简单分子体系的实验研究。这项研究利用了钻石砧座技术的许多发展，包括利用同步辐射、散裂中子散射、激光光谱分析和传输探针的分析方法的进步。将研究致密的氢和以氢为主的简单分子固体、合金和选定的元素，以寻找理论上预测的新的金属化和超导。新发现的高压相，特别是原型元素系统的晶体结构将用同步加速器x射线和中子衍射技术确定，电子结构将用新的x射线非弹性散射方法探索。通过提高我们对凝聚态基本相互作用的理解，该项目将影响纳米科学、行星科学和能源等领域。该项目将推进在更极端条件下研究物质所需的技术。这项研究将寻求提高主要国家设施的能力，并将培训博士后研究员以及高中生、本科生、研究生和访问调查人员。*非技术摘要*这个项目将通过对承受从接近绝对零度到数千度的广泛温度范围内压力达到4兆巴(400万倍大气压)的简单分子物质的实验研究来探索物质的性质。该项目利用了许多最新的发展，使材料能够在这些极端条件下，并在这些条件下使用同步加速器x射线、先进的中子、激光、磁法和电学方法探测样品。富含氢的分子将转化为新的金属和超导体，并将探索金属氢的性质，这是一种预测的全新物质状态。预计材料在极端条件下的晶体结构和化学键的戏剧性变化将使用各种X射线和中子方法来确定。这些结果影响了材料科学、纳米科学、行星科学和天体物理学。这项工作将导致新的含能材料、新型超导体、储气材料和超硬材料的发展。这项研究将增强国家主要设施的能力，并将培养高中生、本科生、研究生、博士后助理和高级科学家。因此，预计会对科学和社会产生广泛的影响。

****TECHNICAL ABSTRACT****Experimental studies of simple molecular systems to pressures of 400 GPa (4 megabars) over a broad range of temperatures will be carried out in this project. The research takes advantage of numerous developments in diamond-anvil cell techniques, including advances in analytical methods that utilize synchrotron x-radiation, spallation neutron scattering, laser spectroscopies, and transport probes. Dense hydrogen and hydrogen-dominant simple molecular solids, alloys, and selected elements will be examined to search for theoretically predicted novel metallization and superconductivity. The crystal structures of newly discovered high-pressure phases, particularly archetypal elemental systems, will be determined using synchrotron x-ray and neutron diffraction techniques, and the electronic structures will be explored using new x-ray inelastic scattering methods. By improving our understanding of fundamental interactions in condensed matter, the project will impact areas such as nanoscience, planetary science, and energy. The project will advance technology necessary for studying matter under more extreme conditions. The research will seek to enhance capabilities major national facilities, and will train post-doctoral fellows as well as high school students, undergraduates, graduate students, and visiting investigators. ****NON-TECHNICAL ABSTRACT****This project will explore the nature of matter through experimental studies of simple molecular substances subjected to pressures reaching 4 megabars (4 million times atmospheric pressure) over a broad range of temperatures from near absolute zero to many thousands of degrees. The project takes advantage of numerous recent developments in the ability both to subject materials to these extreme conditions and to probe samples under those conditions with synchrotron x-ray, advanced neutron, laser, and magnetic and electrical methods. Hydrogen-rich molecules will be transformed into new kinds of metals and superconductors, and the nature of metallic hydrogen, a predicted entirely new state of matter, will be explored. The dramatic changes in crystal structure and chemical bonding expected for materials under extreme conditions will be determined using a variety of x-ray and neutron methods. The results impact materials science, nanoscience, planetary science, and astrophysics. The work will lead to development of new energetic materials, novel superconductors, gas storage materials, and superhard materials. The research will enhance capabilities at major national facilities, and will train high school students, undergraduates, graduate students, postdoctoral associates, and senior scientists. Impacts on both science and society broadly are therefore expected.