The breadth and coverage of analytical expertise in the IEA Technology Collaboration Programmes (TCPs) are unique assets that underpin IEA efforts to support innovation for energy security, economic growth and environmental protection. The 38 TCPs operating today involve about 6 000 experts from government, industry and research organisations in more than 50 countries1.

Stellarator-Heliotron Concept (SH TCP)


Achieving milestones in magnetic fusion

The SH TCP aims to advance applications of physics for fusion power, in particular magnetic fusion devices by developing the stellarator-heliotron concept of fusion reactors. A new world record of stable plasma for 48 minutes was attained in the Large Helical Device (Japan). Construction of the world's largest stellarator device, Wendelstein 7‑X (Germany), reached completion in 2014.

The commissioning and in-vessel assembly of the Wendelstein 7-X device (Greifswald, Germany).*

Stellarators and heliotrons** are fusion devices with external magnetic field coils that confine the plasma. Unlike tokamaks, stellarators and heliotrons do not run electric current through the plasma, thereby reducing instability and avoiding disruptions in the plasma and enabling steady-state operations, an element required to extract power from the fusion process. 

For this reason the SH TCP has engaged in the joint planning and co-ordination of experimental programmes and personnel exchanges between the participating countries to accelerate plasma performance and develop a comprehensive understanding of the physics of toroidal-shaped plasmas. Developments of three of the SH participants are outlined below.

The Large Helical Device (LHD) (Japan) is the largest experimental platform for exploring the heliotron concept. The LHD has provided many opportunities for international collaborations which have in turn led to steady progress in knowledge of fusion science. In 2013, experiments resulted in high-density plasmas at high temperatures (exceeding 90 million°C in the central ions). The steady-state operation of the plasma was sustained for nearly 48 minutes at a temperature of 2 000 electron volts (eV)*** with a heating power of 1.2 MW, resulting in a total energy input of 3.36 gigajoules (GJ) – more than twice the world record of 1.6 GJ previously attained by LHD.

Progress has also been made on construction of the Wendelstein 7-X (W7-X) (Germany), the world’s largest stellarator device with modular superconducting coils. The main assembly of W7-X was concluded in 2014. All technical systems were verified and the first plasma took place on schedule in 2015.

With the implementation of the EUROfusion Consortium for the Development of Fusion Energy in 2014,**** W7-X has become an integral part of the European Fusion Development Agreement (EFDA) Roadmap to the Realisation of Fusion Energy, which aims at integrating fusion electricity into the energy supply network by 2050.

Experiments carried out on the medium-sized heliac device, TJ-II (Spain) have focused largely on fulfilling the scientific and research objectives of the work packages defined in the EUROfusion roadmap as well as development of diagnostics, in particular the understanding of the TJ-II confinement configurations, including isotope and fast particle physics, plasma stability and the effects of impurities.

Other devices that contribute to the work programme of the SH TCP include the Heliotron J (Japan), HSX (United States), H-1NF (Australia) and Uragan 2M and 3M (the Ukraine) and L2-M (Russia). Activities of all the SH TCP participants were compiled in the Executive Committee Annual Report 2014.

* Photo courtesy of Max Planck Institute for PlasmaPysics
** The stellarator is a spherical fusion containment device invented by the astrophysicist Lyman Spitzer (United States). A heliotron is a stellarator device in which a helical coil is used to confine the plasma
*** The electron volt (eV) is a unit of energy equal to the energy acquired by an electron in being accelerated through a potential difference of 1 volt
**** The recently created EUROfusion Consortium for the Development of Fusion Energy manages European fusion research activities on behalf of Euratom (the European Atomic Energy Community)


  • Confinement and profile database
  • Co-ordinated working group meetings
  • DEMO assessment based on SH concepts
  • High-performance and steady-state plasma confinement
  • International workshops
  • Joint experiments, model validations
  • Numerical code verifications


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