The Helmholtz Association’s Nuclear Fusion Programme is currently pursuing two priority goals. On the one hand, the German contribution to building and operating the international tokamak experiment ITER in Cadarache and, on the other, the completion and operation of the stellarator Wendelstein 7-X in Greifswald. ITER aims to prove the physical and, in some cases, technological feasibility of nuclear fusion under power plant-like conditions.

However, ITER alone cannot provide all the information needed for building the demonstrator fusion power plant (DEMO). In particular, the development of suitable structural materials needs to be advanced with great priority parallel to ITER. The potential for improving the magnetic confinement of the fusion plasma has not yet been fully exploited.

An outstanding concept is provided by the stellarator. In principle, it makes a permanently operational fusion plant feasible and so is seen as an alternative to the tokamak. The experiment Wendelstein 7-X aims to qualify the stellarator line to the extent that this, together with the results from ITER, makes the building of a stellarator DEMO possible (from around 2040).