Atom Scattering Facility

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.

The present proposal aims to transition the unique Helium Spin-Echo (HeSE) Atom Scattering instrumentation developed in Cambridge into a sustainable facility that is available to the local, UK and international scientific community. HeSE is a very widely applicable technique for studying the dynamics of atoms and molecules on surfaces over timescales between nanoseconds and picoseconds and lengthscales between Angstroms and nanometres. The technique provides a detailed description of atomistic dynamics at surfaces, so is implicitly linked to many of the EPSRC's 'Grand Challenges' and 'Themes' which involve creating impact through supporting 'bottom up' approaches to technological development.

The whole aim of the present proposal is to enable impact by making the ground-breaking HeSE technique available to UK and international researchers. By establishing the HeSE atom scattering facility we will be able to engage with a much greater part of the scientific community, which in turn will enable us to establish a critical mass of users which can sustain the facility. By engaging more scientists with the HeSE technique, we will dramatically increase the scientific outputs from the technique and the impact generated. Specific impact will thus be generated through individual users' research programmes, so here we only give a broad summary.
Examples of research areas where impact is expected range from understanding the friction between components in nanoscale machinery, to studying the way hydrogen transport switches from a classical to quantum mechanism as the temperature is reduced. A more detailed list of representative areas is given in the academic beneficiaries section.

Our pathways to impact document details an extensive list of the activities which will be carried out in in order to maximise impact generation during the award. The basic principle is to first generate interest through publicity, conferences, direct contact, and electronic communications. Once interest has been stimulated, users will be supported with the development of suitable experimental plans, in securing funding, then in performing experiments and analysing their measurements, and ultimately in publishing their results. Initially, we will focus on existing, experienced, "super-users" while the facility becomes established, before extending our activities to novice users who will require greater resources and support.