CEA Institute for Research into Fusion by Magnetic Confinement (IRFM)

The Institute for Research into Fusion by Magnetic Confinement, IRFM (Institut de Recherche sur la Fusion par Confinement Magnétique), is part of the Fundamental Research Division of France’s Alternative Energies and Atomic Energy Commission, CEA. Located at Cadarache in southern France, it is neither the whole of CEA nor the neighbouring international ITER Organization. It connects plasma physics, experimental operations and in-vessel engineering, contributing to ITER construction, preparation of its scientific operation and the foundations of future fusion machines.

Its defining question is not only how to make a hot plasma, but how to operate for long periods while removing heat and particles. Good core confinement and protection of the walls and exhaust have to be achieved together.

WEST is a transformation of the superconducting Tore Supra tokamak into a stronger test platform for ITER-relevant challenges. The name refers to a Tungsten (W) Environment in Steady-state Tokamak. It combines tungsten plasma-facing components, long-duration operation and radiofrequency heating to investigate heat exhaust for future machines.

Tungsten’s high-temperature properties are not a complete solution. Local heat concentration, erosion, impurities entering the plasma, cooling capacity and monitoring must be considered together. IRFM studies plasma–wall interaction, heat-flow optimisation, tritium in materials, diagnostics, cryomagnetism and radiofrequency heating.

On 12 February 2025, WEST sustained a hydrogen plasma for 1,337 seconds, approximately 22 minutes. The English announcement was published on 19 February 2025; this is not a new 2026 record. Lower-hybrid radiofrequency heating provided heating and current drive while actively cooled tungsten components received the heat. The reported 2.6 GJ was injected and extracted energy, not electricity generated by fusion.

Extended discharges expose component heating and control changes that may be less apparent in short experiments. The significance is sustained management of heating, gas supply, plasma current and wall conditions, not merely a longer clock reading. The result cannot be relabelled as net electricity production or the duration of a burning fusion plasma.

On 3 August 2026, IRFM reported WEST’s first H-mode plasmas with edge-localised modes during the C13 campaign. H-mode improves confinement; ELMs are bursts of heat and particles from the plasma edge. Thus an operating regime that benefits confinement can also produce demanding transient wall loads.

The result expands the opportunity to study transient heat loads and plasma-facing components in an ITER-like tungsten environment. Long-discharge research and H-mode research answer related but different questions: sustained heat handling and control in the first case, edge behaviour of a higher-performance plasma in the second.

IRFM coordinates CEA’s magnetic-confinement fusion work, contracts with Fusion for Energy or the ITER Organization, and French activities within EUROfusion. It also collaborates with French universities and public laboratories. ITER Organization’s project-wide role, F4E’s European contribution and procurement role, and IRFM’s research and technology role should not be conflated.

FI’s assessment is that IRFM generates evidence not just about a material’s heat resistance, but about its behaviour once integrated into a machine. Wall materials, cooling, joints, heating equipment, diagnostics and software affect one another. Applying the results to power plants also requires neutron-lifetime evidence, fuel-cycle integration, maintainability and whole-facility energy accounting. WEST advances part of that work; it is not a completed commercial power plant.

• Presentation of IRFM
• Research areas
• WEST duration result — 19 February 2025
• WEST C13 H-mode and ELM result — 3 August 2026

Edited by FUSION INDUSTRY. Primary sources reviewed on 30 October 2026. Demonstrated results, research objectives and FI’s assessment are distinguished.