Culham Centre for Fusion Energy (CCFE) is the UK's national laboratory for fusion research. CCFE (formerly known as UKAEA Culham) is based at Culham Science Centre in Oxfordshire, and is owned and operated by the United Kingdom Atomic Energy Authority. The UK fusion programme is focused on the MAST experiment, which is one of the world’s two leading spherical tokamaks. The programme is funded by the Engineering and Physical Sciences Research Council and the European Union under the EURATOM treaty. In addition, CCFE hosts and operates the EFDA-JET experimental facilities on behalf of its European partners.
CCFE contributes to all areas of study in tokamak plasma physics research, as part of EFDA co-ordinated programmes, through experiments on MAST, participation in the JET programme, and fusion plasma theory and modelling. These key areas are:
- Confinement: how well energy and particles are retained in the plasma and how this can be improved;
- Stability limits: how high the current, pressure and density can be in the plasma before it becomes unstable;
- Plasma exhaust: the properties of the edge of the plasma, the size of steady and transient heat loads on material surfaces (especially bursts from ‘ELMs’ – Edge Localised Mode instabilities), and the influx of impurities into the main plasma;
- Steady-state operation: while the tokamak is naturally a pulsed device, there are regimes with the potential for continuous (steady-state) operation which, while more difficult to attain, would avoid cyclic stresses and large energy storage systems and therefore be more attractive for a power station;
- Optimum configuration: the JET/ITER design is the most developed system, but other magnetic configurations have advantages, including the more compact spherical tokamak – which was developed at Culham and continues to be tested on MAST.
As well as plasma physics research, there is a major activity on the technology and materials needed for ITER and fusion power stations. CCFE contributes to these areas, particularly to specialist heating and measurement systems needed for ITER, to studies of fusion power stations including DEMO, and to the science of materials needed for power stations with the aim of minimising their activation and their deterioration when exposed to the very fast neutrons from the fusion reactions. Over recent years the contributions of UK universities to the programme, in materials science, plasma physics and engineering, have increased markedly. Around 25 now make contributions to research and/or to student training. The programme also benefits from collaborations with many other EURATOM Associations and with fusion institutes in the rest of the world.