The last issue of Fusion in Europe reported on the formation of EUROfusion, a consortium of fusion laboratories which will manage the European Fusion research accompanying programme. The final signatures are pending, but work has already begun. EUROfusion has launched the 2014/15 Work Programme with a large number of projects, whose goals are set by the Fusion Roadmap. The projects are grouped in four areas: Research on the European tokamak JET, Physics for ITER, Physics and Technology for fusion power plants, and Enabling Research. This article reports on the Work Programmes launched by the EUROfusion Departments for ITER Physics and for Power Plant Physics and Technology.

Plasma physics and heat exhaust

The objectives of the ITER Physics Programme lie in the development of plasma regimes of operation for ITER and in investigating solutions to manage the heat exhaust (i.e. to reduce the heat load at the divertor) in future fusion plants. Supporting these activities are further developments of integrated simulation models for fusion plasmas.

Since January, the European Programme has direct access to three national fusion devices – known as Medium Size Tokamaks or MSTs – on top of its own joint experiment JET. EUROfusion will be able to conduct experiments on the MSTs that cannot be run on JET. Moreover, the new scheme provides more European researchers access to a fusion experiment. The participating machines will also benefit from the competences that the incoming scientists bring with them. Among other things, MST campaigns will investigate plasma scenarios, which enable longer plasma pulses, and transfer the results to JET for further investigation with respect to ITER.

Another focus lies in the divertor. The divertor is an area of the fusion reactor, where impurities and ash from the fusion reaction are removed from the plasma. It experiences the highest heat and particle fluxes. The MST Programme will study divertor configurations that could reduce this heat load. The results will be evaluated so as to decide upon the necessity of a dedicated Divertor Tokamak Test (DTT) facility. The investigation of heat exhaust issues also employs additional experiments operated in Europe: for example, dedicated linear plasma devices will study suitable materials for plasma facing components in future fusion facilities.

Finally, EUROfusion prepares its experimental programmes for two more facilities that will soon become available: JT-60SA, a super advanced tokamak currently being built by Europe and Japan, will start operation in 2019. JT-60SA aims to qualify steady state plasma regimes of operation for ITER. Wendelstein 7-X, an advanced stellarator being built by IPP in Greifswald, will start operating in 2015. Stellarators are a different type of magnetic confinement devices and offer a possible long-term alternative to a tokamak fusion power plant. Wendelstein 7-X will also be operated partly as a common facility and will be used to develop plasma scenarios and exhaust concepts for possible future stellarator fusion power plants.

Physics and Technology for DEMO

Laying the foundation for a Demonstration Fusion Power Reactor (DEMO) to follow ITER by 2050 is the objective of the Power Plant Physics & Technology Work Programme. The central requirements for DEMO lie in its capability to generate several 100 Megawatt of net electricity to the grid and to operate with a closed fuel-cycle (i.e. to produce and burn tritium in a closed cycle).

A number of outstanding technology and physics integration issues must be resolved before a DEMO plant concept selection is made. Each of them has very strong interdependencies. One is the selection of the concept for the breeding blanket. Blankets are the internal components of the reactor wall that absorb the energy from the fusion reaction, ensure the tritium breeding process and shield the components outside the reaction chamber from the fast fusion neutrons. The choice of cooling fluid flowing through the blanket is closely connected to the selection of the Balance of Plant. The latter denotes the sum of all systems that transform the fusion energy into electricity – mainly cooling fluid, turbine and generator. Another matter is the selection of the divertor concept and its layout configuration. The design of the first-wall (i.e. the innermost lining of the reactor wall) and its integration into the blanket is a further issue, since it must take into account that the first-wall might see higher heat loads than assumed in previous studies. Furthermore, there is the selection of the minimum pulse duration of DEMO and of the corresponding mix of plasma heating systems (i.e. heating and current-drive systems). DEMO must be designed in a way that all maintenance work can be carried out remotely via manipulators and therefore reliable and fast maintenance schemes must be selected. The impact of the various system design options on the overall plant reliability and availability are analysed in an integrated approach. The development of DEMO requires many technological advances and innovations in several areas. One example are structural materials that withstand both extreme heat loads and the bombardment with neutrons of unprecedented energy. Another issue is the heat load – not only on the divertor, but also on areas of the reactor wall.

Several projects have been set up to develop reliable design concepts and technologies for reactor components such as the breeding blanket, the magnet system, the divertor, the heating and current drive systems, the fuelling and vacuum systems, the Balance of Plant, etc. Each project is lead by a Project Leader and the work is carried out by a team made up from members of the European Research Units. Since several components and systems are strongly interconnected, the EUROfusion Programme Management Unit (PMU) ensures the integration of the projects into the coherent DEMO Concept Design Activity. In particular the PMU has several tasks: It identifies and manages interfaces among various project work packages and between the DEMO systems. It also ensures the effective communication among the projects. It identifies and supports trade-off and sensitivity studies and facilitates a system-level decision and solution selection process. The PMU also coordinates the DEMO requirements analysis, the plant-level analysis and system modelling. Another task is to ensure that the physics R&D needed in order to consolidate the DEMO physics basis is pursued in the relevant Work Packages. Industry is expected to take an active role in the DEMO concept design activities and thus provide key technical knowledge and guidance to the programme.