25/09/2025
France Sets New World Record with 22-Minute Fusion Plasma Run
France has broken the record for the longest sustained plasma in a tokamak, pushing forward the frontier in nuclear fusion research. On 12 February 2025, the WEST (W Environment in Steady-state Tokamak) device at the CEA’s Cadarache facility held a hydrogen plasma for 1,337 seconds — just over 22 minutes.
This achievement edges out a previous record of ~1,066 seconds set by China’s EAST tokamak by about 25%. The duration was made possible using ~2 MW of heating power and with active cooling of the internal tungsten components so they held up under the extreme plasma-facing conditions.
Holding a plasma steadily for such a long time is a crucial milestone because one major challenge in fusion power is sustaining extreme conditions (very high temperature, pressure, magnetic confinement) over long periods without damage or loss of control. WEST’s result is especially relevant for informing how upcoming, larger fusion reactors like ITER will need to operate.
While this is a big leap forward in duration, it’s worth noting that this run was not optimized for net energy gain; it was focused on stability and materials endurance. The ultimate goal remains a fusion reactor that produces more usable energy than is consumed.
Why It Matters
Engineering endurance: Prolonged exposure tests internal components (such as the divertor, walls, etc.) under stress similar to what a power plant would experience.
Control & stability: Plasma is highly unstable; maintaining it for longer periods helps refine control methods (magnetic confinement, heat exhaust, etc.).
Path toward ITER & commercialization: Data and techniques from WEST help in scaling up to ITER-sized machines and ultimately fusion power plants.
What’s Next
Researchers plan to increase both the power injected into the plasma and the duration even further — possibly targeting runs lasting hours — while pushing toward improved confinement and higher temp
