Wendelstein 7-X

node · earth · Mecklenburg-Vorpommern

Wendelstein 7-X is the world's largest optimised stellarator, operated by the Max Planck Institute for Plasma Physics at its Greifswald site in northern Germany and completed in 2015. It exists to test whether the stellarator's steady-state advantage can be combined with confinement quality comparable to a tokamak. In its 2025 campaign it reported a record triple product for long-duration plasmas, sustained for 43 seconds, exceeding previous long-pulse tokamak values; an energy turnover record of 1.8 gigajoules in a 360-second discharge; and plasma pressure reaching 3% of magnetic pressure across the whole plasma volume for the first time. W7-X runs on hydrogen and helium, not deuterium-tritium, so it produces no significant fusion power and holds no gain record. It is included here because it is the clearest evidence that magnetic confinement is not a single ladder with one design at the top.