French WEST Reactor Shatters Plasma Duration Record, Advancing Fusion Energy Quest

The WEST (Tungsten Environment in Steady-state Tokamak) reactor in France has achieved a significant breakthrough in nuclear fusion research, setting a new world record for plasma duration. On February 12, 2025, the facility successfully maintained a plasma for an unprecedented 1,337 seconds, which is over 22 minutes, as reported by cea.

This remarkable achievement, conducted at the CEA Cadarache site, represents a 25% improvement over the previous record. China's EAST tokamak had held the prior record, sustaining plasma for 1,066 seconds in January 2025, according to Physics World.

During the record-breaking experiment, the plasma within the WEST tokamak reached an extreme temperature of 50 million degrees Celsius, as detailed by Advanced Science News. This milestone is considered a crucial step towards developing sustainable nuclear fusion energy, a long-sought goal for clean power generation.

Anne-Isabelle Etienvre, Director of Fundamental Research at the Commissariat à l'énergie atomique et aux énergies alternatives (CEA), emphasized that WEST has achieved a key technological milestone. She stated that maintaining hydrogen plasma for over twenty minutes with 2 MW of heating power is a significant advance, as reported by New Atlas.

The success of the WEST project demonstrates growing maturity in the scientific community's understanding and control of high-temperature plasmas. This progress offers considerable hope for stabilizing fusion plasmas for extended periods in larger machines like the International Thermonuclear Experimental Reactor (ITER), according to the CEA.

The ability to sustain plasma for such an extended duration is vital for future fusion power plants, which require long, steady operational conditions. Earth.com highlighted that this performance also proves researchers can manage tough operating conditions without internal components degrading.

The WEST tokamak, operating with a tungsten divertor, serves as a critical testbed for ITER, which is currently under construction nearby in southern France. The insights gained from WEST are directly contributing to the design and operational strategies of the larger international project, as noted by PAC World.

• Historical Context and Fusion's Promise: Nuclear fusion, the process powering the sun, involves merging light atomic nuclei to release vast amounts of energy, offering a potentially limitless and clean power source. Scientists have pursued this goal for over 70 years, with the challenge lying in replicating and sustaining the extreme conditions required on Earth, as explained by Energy Reporters.

• The Role of Tokamaks: Tokamaks are toroidal devices that use powerful magnetic fields to confine superheated plasma, preventing it from touching the reactor walls. This magnetic confinement is crucial for heating deuterium and tritium to temperatures far exceeding the sun's core, a fundamental principle highlighted by Earth.com.

• Previous Record and Competition: Before WEST's breakthrough, China's Experimental Advanced Superconducting Tokamak (EAST), often called the "artificial sun," held the record. On January 20, 2025, EAST sustained a high-confinement plasma for 1,066 seconds at nearly 70 million degrees Celsius, a milestone reported by Physics World and Nuclear Engineering International.

• Implications for ITER: The WEST reactor's success is particularly significant for ITER, the world's largest magnetic confinement plasma physics experiment, also located in Cadarache. The cea stated that WEST's results demonstrate how knowledge of plasmas and their technological control are maturing, offering hope for stabilizing fusion plasmas in machines like ITER.

• Challenges in Fusion Energy: Despite these advancements, achieving sustainable fusion energy faces several complex challenges. These include maintaining plasma stability, developing materials that can withstand extreme temperatures and neutron radiation, ensuring economic viability, and managing tritium breeding, according to consensus Academic Search Engine and R Discovery.

• ITER's Revised Timeline and Future: While ITER's construction is progressing, its timeline has been revised. Initial plasma experiments, originally slated for 2025, are now expected by 2033-2034, with deuterium-deuterium fusion operations in 2035 and deuterium-tritium operations by 2039, as reported by World Nuclear News and Wikipedia.

• Growing Investment and Commercialization: The fusion energy sector is experiencing rapid growth in investment, with private funding exceeding $10 billion by 2025, according to nucnet. The Fusion Industry Association reported that total industry funding jumped from $1.7 billion in 2020 to $15 billion by September 2025, reflecting increasing confidence in the technology's potential, as noted by Time Magazine.

• Next Steps for WEST: The CEA has outlined future plans for the WEST team, aiming to achieve even longer plasma durations, potentially up to several hours combined. These experiments will also focus on heating the plasma to higher temperatures to further approach the conditions necessary for practical fusion power, as stated by the CEA.