Fusion Facilities Review Panel assesses the facilities of the European Research Programme

This independent panel of experts was appointed by the EU Commission to identify the research objectives needed to realise a fusion power plant. Then it had to ascertain which experimental devices in the European Fusion Research Programme can contribute to these objectives. All devices – existing, under construction or planned – had to be assessed according to their relevant capabilities.

The objective of fusion research is to derive energy from fusion of atomic nuclei, as happens in the sun. To ignite the fusion fire in a power plant one has to succeed in confining the fuel – ionised hydrogen gas of extremely low density, called plasma – keep it stable and thermally insulated, and heat it to temperatures of over 100 million degrees. The members of the Fusion Facilities Review Panel** emphasised the special situation of fusion research as a long-term pursuit with a specific objective and stated that they were impressed by the progress achieved: nuclear fusion has prospects of providing a new, almost inexhaustible energy source favourable to the climate and environment. Achieving efficient power production presents, however, major challenges. The report now submitted, “R&D Needs and Required Facilities for the Development of Fusion as an Energy Source”, reviews the status of fusion research and the requirements to be met on the way to a fusion power plant.

The key device in the coming decades will be the ITER international test reactor, now being built at Cadarache, France, as a joint operation involving Europe, Japan, Russia, USA, China, South Korea and India. ITER is to demonstrate that a fusion plasma yielding energy is possible. With a fusion power of 500 megawatts it is to produce ten times as much power as is needed to heat the plasma. Properly preparing the experiments in the large-scale device and subsequently attaining the greatest possible scientific yield call for support from smaller, more specialised and more flexible fusion devices, and also from technological and computing facilities. In a “schedule” extending to the year 2035, i.e. till the planned start of construction of the DEMO demonstration power plant to follow ITER, the panel graded the European facilities – existing, under construction or planned – according to their usefulness for ITER and DEMO.

The JET (Joint European Torus) large-scale experiment in Culham, UK, tops the list as the most important “satellite” device for preparing for ITER. With a plasma volume of 80 cubic metres – ten times smaller than the ITER plasma – the JET experiment conducted jointly by all the European fusion laboratories is at present the world’s largest and most powerful device. In a mode of operation developed at IPP the JET team succeeded in 1997 in generating 16 megawatts of fusion power, this being 65 per cent of the heating power input. JET is now being modified for objectives relevant to ITER and should, according to the panel, continue operation till at least 2014/15. Major contributions are also expected from the similarly sized JT-60SA in Japan. This device is now being modified in a Japanese-European cooperation and is scheduled to go into operation in 2016. Unlike JET with its copper magnet coils, JT-60SA will be fitted with superconducting magnet coils. This allows investigations with much longer plasma pulses.

Of the twelve medium-sized European devices assessed, the panel considered Garching’s ASDEX Upgrade device to be “most suited for efficient support of ITER and the ITER satellites”. The panel concluded that ASDEX Upgrade is capable of covering a wide range of topics to accompany the construction of ITER till 2018 and then also support its operation for another ten years. In view of the similar plasma shapes with different sizes of plasma going up the ladder ASDEX Upgrade – JET – ITER, comparative experiments promise particularly fruitful results. If DEMO continues this line of development, then ASDEX Upgrade in its size category is also considered by the panel to be the closest device to DEMO in Europe.

Another line of development is to be pursued by Wendelstein 7-X. This device, now being built at the Greifswald branch of IPP, is of the alternative stellarator type. Its objective is to demonstrate the power plant potential of the stellarator concept. Accordingly, the panel assesses its relevance to DEMO as “very high”. Classifying it overall as of “medium” importance for ITER the panel went on to state that Wendelstein 7-X with its superconducting magnet coils could primarily contribute important know-how on the continuous mode of operation.

Besides IPP’s two plasma devices, the grade of “very high priority” was also awarded to the test rigs planned for material development, plasma heating and superconducting magnets as well as to a powerful computer for numerical modelling of the plasma behaviour. The panel made the overall recommendation to the European Fusion Research Programme that the present division of labour with its highly networked character be maintained and expanded. Furthermore, the training of the specialists needed for the research programme was emphasised as a particularly important task of the European laboratories.

**Fusion Facilities Review Panel
The Fusion Facilities Review Panel, appointed in December 2007 at the beginning of the Seventh European Research Framework Programme (2007 – 2013) by the EU Commission, comprised five European members outside the fusion research community and four non-European fusion experts. Under the chairmanship of Prof. Dr. Thomas Hartkopf, head of the Department of Regenerative Energies at the Institute for Electrical Energy Systems of TU Darmstadt, the panel terminated its work in October 2008 after several meetings, video conferences and laboratory visits as well as the study of numerous documents by unanimously approving the final report now submitted, “R&D Needs and Required Facilities for the Development of Fusion as an Energy Source”.