Atom Scattering Facility

一旦科学家们弄清楚了如何在表面上对单个原子进行成像，了解它们的运动方式立即成为一个重大挑战。在原子尺度上，过程发生得非常快，通常在十亿分之一秒的时间尺度上。很长一段时间以来，根本没有工具可以测量如此短的时间和如此短的距离内发生的事情。原子和分子如何运动的细节只能靠猜测，而且只能使用最简单的建模方法。值得注意的是，现在有可能使用一种称为氦自旋回波（HeSE）的技术来跟踪原子和分子在这些长度和时间范围内的运动——这是一种跟踪原子在稳态热运动的方法。这项技术是由埃利斯和他在剑桥的同事开发的，他们得到了包括EPSRC在内的许多来源的大量资助。英国现在在使用这种全新的技术和设备来理解表面上原子和分子的运动方面处于世界领先地位。了解单个原子和分子的运动是非常重要的。尽管许多科学进步是在经验上取得的，但它很快就变得不可能再进一步了（例如，发现氨合成的哈伯-博世催化剂花了2万次实验）。有了原子如何运动的知识，就有可能从“下至上”设计材料和工艺，或者进行精确的数值模拟，给出明确的预测。因此，HeSE可以提供的信息在众多科学学科中都是无价的。事实上，HeSE已经表明，公认的原子运动建模方法可能存在非常真实的不准确性，而且许多理论需要改进。这台HeSE机器的开发一直是剑桥大学物理系的一个重大项目。我们现在希望释放新技术的力量，并从EPSRC资助的发展中获得最大的影响，使其可供更广泛的科学界使用。因此，目前的提案旨在将设备设置为用户设施，向来自英国其他地区和国际的用户开放。在两年的奖励期内，设备将被精简，培训课程和材料将被生成，数据分析工具将被创建。最重要的是，我们将积极参与并支持来自许多科学和技术学科的研究人员，他们可以从超快原子尺度动力学测量中受益。

Once scientists worked out how to image individual atoms on a surface, understanding the way they move immediately became a major challenge. On the atomic scale processes occur very quickly, often over the time scale of a billionth of a second. For a long time, there were simply no tools that could measure what was happening over such short times and such small distances. The details of how atoms and molecules move could only be guessed, and only the very simplest of modelling methods could be used. Remarkably, it is now possible to follow the motion of atoms and molecules over these length and time ranges using a technique called helium spin-echo (HeSE) - a method that follows atoms in steady state thermal motion. The technique was developed by Ellis and co-workers in Cambridge, with substantial funding from many sources, including the EPSRC. The UK now leads the world in understanding the motion of atoms and molecules on surfaces using this radically new technique and the equipment that was developed.Understanding the motion of individual atoms and molecules is incredibly important. Although many scientific advances have been made empirically, it very quickly becomes impossible to progress further (for example, finding the Haber-Bosch catalyst for ammonia synthesis took 20,000 experiments). With knowledge of how atoms move it is possible to design materials and processes from the 'bottom up', or to perform accurate numerical simulations that give clear predictions. Hence, the information HeSE can provide is invaluable across a huge range of scientific disciplines. In fact, HeSE has already shown there can be very real inaccuracies of the accepted modelling methods for atomic motion - and that many theories need to be improved.The development of this HeSE machine has been a major project in the Department of Physics in Cambridge. We now hope to unleash the power of the new technique, and gain maximum impact for the UK from this EPSRC funded development, by making it available for use by the wider scientific community. The current proposal therefore aims to set the equipment up as a user facility, open to users from the rest of the UK and internationally. During the 2 year award period the equipment will be streamlined, training courses and materials will be generated and data analysis tools will be created. Most importantly we will proactively engage with and support researchers from the many scientific and technological disciplines which can benefit from ultra-fast atomic scale dynamics measurements.