On February 12, 2025, the WEST tokamak, located at CEA Cadarache in southern France, set a new world record by sustaining fusion plasma for 1,337 seconds, or over 22 minutes. This achievement marks a 25% improvement over the previous record set by China’s EAST tokamak just weeks earlier. WEST is part of the EUROfusion consortium’s network of medium-sized tokamaks, playing a vital role in advancing research for ITER, the world’s largest fusion experiment currently under construction.

Maintaining stable plasma for extended durations is a critical milestone for developing fusion energy. The challenge lies in controlling the naturally unstable plasma while ensuring that the components exposed to its high radiation—such as tungsten tiles—can withstand the extreme conditions without malfunctioning or contaminating the plasma. This capability will be essential for ITER, which aims to produce energy through fusion reactions over several minutes in its operational phases.

The recent record was achieved using a lower hybrid (LH) radiofrequency antenna that injected 2 MW of heating power into the plasma. This antenna generates a current by accelerating electrons, stabilizing the plasma and preventing disruptions. During the record-setting experiment, the actively cooled tungsten components extracted 2.6 gigajoules (GJ) of energy, showcasing the robustness of the system and its suitability for long-duration experiments.

According to Gianfranco Federici, EUROfusion Programme Manager, "WEST is an important facility for preparing the ITER exploitation towards the development of fusion energy. It plays a key role in implementing the EUROfusion programme within EURATOM." His statement highlights the strategic importance of WEST in ensuring Europe’s leadership in fusion research.

Moving forward, the WEST team will focus on increasing plasma heating power to 10 MW over durations of about 1,000 seconds. This corresponds to a fusion power of several gigawatts in a machine the size of ITER. Such efforts will allow scientists to simulate conditions expected during ITER’s deuterium-tritium (DT) operational phase and evaluate how long plasma-facing components can endure these extreme conditions.

Mastering plasma control for extended periods is a technological challenge but an essential step toward achieving sustainable fusion energy. These advancements bring the scientific community closer to realizing fusion power on an industrial scale.

For more information, please visit:
https://euro-fusion.org
https://irfm.cea.fr

Watch the video of this world record: https://www.youtube.com

Photo: WEST tokamak in Cadarache, France. Credit: CEA / C. Roux

Source: EUROfusion