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Wendelstein 7-X Stellarator Experiment (W7-X)
Hosting Legal Entity
Self-standing RI
Legal Status
Research organisation
Wendelsteinstraße 1, Max-Planck-Institut für Plasmaphysik, Greifswald, PO: 17489 (Germany)
Type Of RI
Coordinating Country
Participating Countries
European Union
Current Status:
Operational since 2018
Being upgraded since 2019 to 2020
Operational since 2015 to 2017
Scientific Description
Wendelstein 7-X is a drift-optimized stellarator with a rotational transform close to unity and low magnetic shear suitable for an island divertor. Its core mission is the demonstration of power plant capabilities of optimized stellarators of the modular HELIAS (HELical Advanced Stellarator) concept. It is designed to combine confinement under fusion-relevant conditions, robust equilibrium and stability properties, a feasible exhaust concept, full steady-state technology with superconducting coils, actively cooled in-vessel components, and a continuous wave electron cyclotron resonance heating system. Beyond the validation of stellarator optimization in high-performance discharges, W7-X is to develop integrated steady-state plasma scenarios with high plasma pressure and confinement time, which can be extrapolated to burning fusion plasmas at low collisionality.

The further developed successor, Wendelstein 7-X, is now to investigate the new stellarator’s suitability for a power plant. It is expected that plasma equilibrium and confinement will be of a quality comparable to that of a tokamak of the same size. But it will avoid the disadvantages of a large current flowing in a tokamak plasma: With plasma discharges lasting up to 30 minutes, Wendelstein 7-X is to demonstrate the essential stellarator property, viz. continuous operation.

RI Keywords
Magnetic confinement, Plasma physics, Stellarator, HELIAS, Thermonuclear fusion
RI Category
Nuclear Research Facilities
Scientific Domain
Physics, Astronomy, Astrophysics and Mathematics
ESFRI Domain
Physical Sciences and Engineering
Participation in experimental campaigns of Wendelstein 7-X

Calls for participation in the scientific programme of Wendelstein 7-X will be launched on an annual basis. Scientists in particular from EUROFUSION members but also from international fusion labs will be invited to conduct experiments on Wendelstein 7-X.

Wendelstein 7-X: Superconducting stellarator for the development of steady-state plasma scenarios

Numerically fully optimized current-free stellarator (based on the concept of quasi-isodynamicity). Major radius: 5.5 m, minor radius: 0.53 m 5 periods 70 superconducting magnets 50 modular coils 20 planar Coils Superconductor: NbTi Current density in coil 48 MA/m2 Magnetic field on axis: up to 3.0 T Magnetic Energy: 600 MJ Rotational transform on axis: 0.84 rotational transform at boundary: 0.99 Heating systems: ECRH (140 GHz, 8 MW for 30 min.) NBI (8 MW/10 s)

Access Type
Access Mode
Excellence Driven
Date of last update: 16/05/2018