The EUROfusion consortium has announced a new world record for energy output from a fusion experiment, achieved during the final operational phase of the Joint European Torus (JET) at the UK Atomic Energy Authority's Culham Campus. In its third deuterium-tritium campaign (DTE3), the tokamak produced 69 megajoules of sustained fusion energy over a 5.2-second pulse, surpassing its own 2021 record of 59 MJ. The experiment, which consumed only 0.2 milligrams of D-T fuel, demonstrated an average power output of 12.5 MW. This result was achieved in pulse #104522 on October 3, 2023, just before JET ceased plasma operations in December 2023 after four decades of service. Source: EUROfusion

This final experimental campaign was designed explicitly to test operational scenarios critical for the success of its successor, ITER. JET's carbon wall was replaced in 2011 with an ITER-like wall made of beryllium and tungsten, providing a unique platform to study plasma-wall interactions and fuel retention with the same materials planned for the larger device. The DTE3 experiments successfully demonstrated stable plasma scenarios under conditions that replicate those anticipated in ITER, providing crucial data for heat and particle exhaust management, controlling plasma instabilities, and validating neutronics codes. The results confirm the viability of the material choices and operational strategies for future fusion power plants based on the tokamak concept. Source: EUROfusion

This final experimental campaign was designed explicitly to test operational scenarios critical for the success of its successor, [ITER](/programs/iter).

The record-setting pulse is the culmination of over 100,000 experiments conducted at JET throughout its operational history. As the only operational tokamak capable of running on a deuterium-tritium fuel mix before ITER begins its D-T phase, JET has been an indispensable tool for the global fusion community. Its contributions extend beyond energy records to include foundational research in alpha particle heating, where the energetic helium nuclei from D-T reactions self-heat the plasma, a critical process for achieving a burning plasma. The data gathered from DTE3 by over 300 scientists will be analyzed for years, informing the operational plans for ITER, DEMO, and other commercial fusion ventures. Source: EUROfusion

With JET's decommissioning now underway, the focus of the European fusion program shifts fully to the construction and commissioning of ITER in France. The successful demonstration at JET provides a high degree of confidence in the physics and engineering basis for ITER's design, which aims to produce 500 MW of thermal fusion power from 50 MW of input heating power, representing a plasma energy gain (Q_plasma) of 10. The JET results validate the plasma control schemes and confinement scenarios necessary to reach this target. The transition marks the end of a significant era in fusion research while simultaneously providing a robust, experimentally-verified foundation for the next generation of burning plasma devices. Source: EUROfusion