Air Liquide’s ITER cryoplant is operational: a major fusion milestone
- Cryogenics
- News
From the beginning of the adventure, Air Liquide is a key partner of ITER (International Thermonuclear Experimental Reactor), in particular through its cryoplant, a critical engineering marvel designed to solve an unparalleled thermal paradox at the heart of the world's most ambitious fusion energy experiment.
To recreate the energy of the stars on Earth, the ITER tokamak must create a plasma reaching approximately 150 million degrees Celsius. This incredibly hot plasma is confined and controlled using powerful electromagnetic fields generated by massive superconducting magnets. However, these magnets can only achieve superconductivity if they are cooled to temperatures hovering just above absolute zero which is -273°C. This requires an unprecedented supply of extreme cold, which is why the ITER cryoplant, an installation the size of a football field, is the largest centralized refrigeration system ever built.
The cryoplant operates using two main cooling systems
To cool the 10,000 tons of superconducting magnets and the reactor's cryopumps, the Helium Refrigeration System relies on supercritical helium at 4.5 Kelvin (-269 °C). The Liquid Helium plant was done under a contract with ITER Organization. Air Liquide designed and manufactured three giant helium refrigerators that boast a record combined cooling capacity of 75 kW at 4.5 K. To distribute this extreme cold, Air Liquide was also contracted to supply 1.6 km of highly sophisticated cryogenic lines to transfer the cryogenic fluids.
The Liquid Nitrogen (LN₂) Plant, operating alongside the helium units and also designed and built by Air Liquide, is a very large and impressive liquid nitrogen system. The Liquid Nitrogen plant and other systems are under a contract with Fusion for Energy, as part of the European contribution to the ITER project. This plant acts as a pre-cooler for the helium refrigerators, and it supplies cold gas to the vast thermal shields surrounding the reactor.
The successful commissioning by the teams of both the helium refrigeration plant and the liquid nitrogen plant in 2025 and 2026 are crucial milestones for the ITER project. We are proud of these achievements, which showcases Air Liquide’s innovation and cutting-edge engineering at unprecedented scale to support major scientific breakthroughs.
