Wendelstein 7-X by Max Planck Institute for Plasma Physics: status and timeline

Milestones

Next · OP 2.3 experimental campaign ongoing

First plasma2015Complete.
1.3 gigajoules energy turnover achieved (360 seconds)Feb 2023Complete.
1.8 gigajoules energy turnover achieved (360 seconds)May 2025Complete.
43-second triple-product record (May 2025)May 2025Complete.
OP 2.3 experimental campaign ongoingTarget 2025Current milestone.
Reach 4–5% plasma pressure ratioTarget 2026Not yet reached.

Most important updates

Upcoming

2025OP 2.3 experimental campaign ongoing (next)
2026Reach 4–5% plasma pressure ratio
2026Plasma durations toward several minutes

Current obstacles

Scaling to commercial sizesLarger reactors must produce net energy consistently with advanced magnet and control systems.
Managing edge plasma instabilitiesAt the boundary of the plasma, instabilities can cause energy loss and wall damage; understanding and controlling these is key to longer pulses.

Physics limits

Magnetic field strength limits efficiencyStronger magnetic fields confine hotter, denser plasma, but superconducting magnets have practical limits (~12–15 Tesla); higher fields require advances in magnet technology.
Energy confinement degrades with sizeAs fusion reactors scale up, plasma energy escapes faster relative to its volume, a physics constraint that requires better plasma control strategies.
Plasma energy must exceed heating inputCommercial fusion requires the plasma to release more energy than the heating systems consume; today's experiments approach but have not yet exceeded this threshold.

How it works

3 parts

Magnetic coil geometry

Specially shaped coils for stability

Designed coils confine plasma, offering inherent stability.

Pellet injection

Continuous refueling of plasma

Pellet injector shoots frozen hydrogen into plasma, enabling long-pulse operation.

Donut geometry

Large-scale plasma vessel

The donut (toroidal) shape confines the plasma in a stable path, reducing the risk of plasma escaping the magnetic field.

Spec sheet

Spec	Wendelstein 7-X
Triple-product record May 2025	43 seconds^R (reported)
Energy turnover 2023	1.8 gigajoules over 360 seconds^R (reported)
Peak ion temperature	Around 40 million degrees Celsius^R (reported)
Plasma pressure ratio	3% across full volume^R (reported)

^R reported by the company

Papers & demos

1 item

22 May 2025demo
W7-X sets 43-second triple-product record (opens ipp.mpg.de)Stellarator achieves fusion parameters comparable to tokamaks.

Update log

2 updates

May 2025

Major: W7-X sets 43-second triple-product record, exceeding tokamak performancePaperResearch

Feb 2023

Major: W7-X achieves 1.3 gigajoules energy turnover in 8-minute plasma runPaperResearch

About Max Planck Institute for Plasma Physics

The team behind Wendelstein 7-X

Max Planck Institute for Plasma Physics

Wendelstein 7-X stellarator, fusion research, DEMO reactor

Max Planck Institute for Plasma Physics operates Wendelstein 7-X and ASDEX Upgrade in Germany, advancing fusion science through research.

W7-X set world record 43-second triple-product in May 2025, exceeding tokamak performance.
IPP sites in Garching and Greifswald run ASDEX Upgrade and collaborate on DEMO.
Advancing stellarator physics toward commercial fusion power plant validation.

ipp.mpg.de (opens ipp.mpg.de)Company profile →

Headquarters: Germany
Status: Non-profit
Valuation: non-profit
Works in: EnergyFusion
Coverage: 1 program · 2 updateslatest 1 May 2025checked 11 Oct
Partners: Oak Ridge National Laboratory (opens ornl.gov)ITER Organization

Spec

Wendelstein 7-X

Triple-product record May 2025

43 seconds^R (reported)

Energy turnover 2023

1.8 gigajoules over 360 seconds^R (reported)

Peak ion temperature

Around 40 million degrees Celsius^R (reported)

Plasma pressure ratio

3% across full volume^R (reported)