Comparison of helical devices

The properties of different helical confinement concepts such as Stellarators or Heliotrons are compared in the context of an international collaboration ultimately to assess on the option of this concept in view of a fusion power plant.

Plasma confinement with externally applied helical magnetic fields – such as stellarators or heliotrons – aims at an fusion power plant concept that is alternative to the tokamak. Here the term heliotron stands for a particular branch of the stellarator family which has been developed in Japan. An important task is the intermachine comparison of confinement and transport. In order to enhance the effectiveness of the international cooperation in this area, a joint database has been established.

The international Stellarator-Heliotron Profile Database under auspices of the IEA Implementing Agreement for Cooperation in Development of the Stellarator-Heliotron Concept is is jointly hosted by the Max-Planck-Institut für Plasmaphysik (Greifswald, Germany) and the National Institute for Fusion Science (Toki, Japan). The general philosophy is to collect and assess the contributions for a concise documentation of stellarator-heliotron performance. Assessments of the energy confinement, for example, are expressed in forms of International Stellarator Scalings, ISS, which allows to extrapolate to reactor performance.

The international collaboration is aligned by regular meetings of the Coordinated Working Group (CWG) which also proposes joint experiments of the different stellarator-heliotron devices.