Mid-scale RI-1 (M1:IP): NSF National EXtreme Ultrafast Science (NEXUS) Facility

在NSF化学部门通过中型研究基础设施-1计划的支持下，由俄亥俄州州立大学（OSU）的Robert Baker领导的团队正在实施NSF国家极端超快科学（NEXUS）设施-一种超越最先进的国家XUV光源，作为开放访问的用户设施为科学和工程界服务。该光源将与一系列多功能实验能力相结合，旨在促进国家优先领域的变革性进展，重点是能源转换和量子信息科学。这座国家设施首次将高功率激光器的新技术带到美国。这种中等规模的基础设施弥合了桌面仪器与自由电子激光器和同步加速器等大型设施之间的差距。该设施还为更广泛的社区带来了新的能力，并有助于美国在全球格局中的竞争力。建成后，该设施将可供研究人员寻求跨化学，物理，材料科学和其他学科的新见解。该设施的核心是一种新的激光技术，用于产生极紫外线和软x射线光子能量，重复频率为数百千赫，平均功率超过1千瓦。阿秒时间分辨率、高能量和高重复率的组合使得目前无法在实验室环境中使用现有技术进行测量。该设施将提供以下实验平台，具有阿秒到飞秒的时间分辨率，具体取决于实验：1）X射线吸收/反射光谱，2）X射线磁圆二色性，3）扫描隧道显微镜，4）角度分辨光电子能谱，和5）激光诱导电子衍射。应用包括仿生光合作用和新的量子信息技术等科学挑战。使这些应用成为可能的是在远离平衡的系统中以单个电子和原子的规模控制物质的能力。该项目直接响应了社区确定的重大挑战，需要在阿秒时间尺度上以亚纳米空间分辨率观察相关材料中的电荷和自旋输运。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the NSF Division of Chemistry through the Mid-scale Research Infrastructure-1 program, a team led by Robert Baker at The Ohio State University (OSU) is implementing the NSF National EXtreme Ultrafast Science (NEXUS) Facility - a beyond-the-state-of-the-art national XUV light source to serve the scientific and engineering communities as an open-access user facility. This light source will be coupled to a versatile array of experimental capabilities, designed to facilitate transformative progress in areas of national priority with emphasis on energy conversion and quantum information science. This national facility brings new technology in high-power lasers to the US for the first time. This mid-scale infrastructure bridges the gap between tabletop instruments and large-scale facilities such as free electron lasers and synchrotrons. This facility also brings new capabilities to the broader community and contributes to US competitiveness in the global landscape. Upon completion, the facility will be available to researchers seeking new insights across chemistry, physics, materials science, and other disciplines. At the heart of this facility is a new laser technology for producing extreme ultraviolet and soft x-ray photon energies at repetition rates of hundreds of kilohertz with average power exceeding one kilowatt. The combination of attosecond time resolution, high energies, and high repetition rates enables measurements that currently cannot be made with existing technology in a laboratory setting. The facility will provide the following experimental platforms with attosecond to femtosecond time resolution, depending on the experiment: 1) X-Ray Absorption/Reflection Spectroscopy, 2) X-Ray Magnetic Circular Dichroism, 3) Scanning Tunneling Microscopy, 4) Angle-Resolved Photoemission Spectroscopy, and 5) Laser-Induced Electron Diffraction. Applications include such scientific challenges as biomimetic photosynthesis and new quantum information technologies. Enabling these applications is the ability to control matter at the scale of individual electrons and atoms in systems that are far from equilibrium. This project directly responds to community-identified grand challenges requiring observation of charge and spin transport in relevant materials on the attosecond timescale with sub-nanometer spatial resolution.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.