W7-X sets 43-second triple-product record, exceeding tokamak performance

Max Planck Institute for Plasma Physics/Wendelstein 7-X

Wendelstein 7-X achieved a 43-second sustained triple-product record on May 22, 2025. The triple product—plasma density × temperature × confinement time—is a key fusion metric. W7-X exceeded tokamak records at comparable scale, with plasma temperatures of 20–30 million degrees and 3% plasma pressure ratio.

• 43-second record surpasses tokamak performance at equivalent volumes, validating stellarator design for extended operations.
• Plasma temperatures of 20–30 million degrees sustained for 43 seconds in the record run.
• Achieved 3% plasma pressure ratio; separate experiments that day reached 40 million degrees.
• Oak Ridge pellet injector system enabled the extended pulse duration and sustained hydrogen refueling.