Atom Scattering Facility

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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.