At a press conference on February 8, 2024, the EUROfusion consortium announced the successful completion of the third and final deuterium-tritium experimental campaign (DTE3) in the JET fusion device. The Joint European Torus (JET), one of the largest and most powerful fusion reactors in the world, has proven that fusion energy can be reliably reproduced, while also achieved a world record for fusion energy produced. In the experiments, fusion processes and methods of controlled production of fusion energy were investigated under similar conditions as will be used in future fusion power plants, which means significant progress towards the understanding of fusion plasma.

In the latest experiments with deuterium and tritium (DTE3) as fuel, the pulse in JET on October 3, 2023, reached high fusion power for a continuous 5.2 seconds. Using just 0.2 milligrams of fuel, it produced a record 69 megajoules (MJ) of fusion energy.

More than 300 European scientists and engineers from the EUROfusion consortium participated in the DTE3 experimental campaign on the JET device together with the technical and scientific staff of the UK Atomic Energy Authority (UKAEA), including also researchers from the Slovenian Fusion Association (SFA).

JET is currently the only existing fusion facility that can operate with a high-performance mixture of deuterium and tritium, i.e. fuel that will be used in future fusion power plants. While most fusion experiments use only hydrogen or deuterium, testing with a mixture of deuterium and tritium is essential to achieve the most similar conditions as in a real fusion power plant.

Experiments on JET have optimized fusion reactions with deuterium and tritium and developed methods and technology to control fuel containment, heat dissipation and materials development. This has provided key insights for the design and operation of future reactors such as the international experimental reactor ITER and demonstration fusion power plant DEMO, as well as for all other projects around the world focused on the development of fusion power plants. The achieved results confirm the key role of the JET reactor in the development of safe, low-carbon and sustainable fusion energy.
For more than four decades, JET has been critical to the development of fusion energy, symbolizing international scientific collaboration, engineering excellence and commitment to harnessing the power of fusion energy – the reactions that power the Sun and stars. In 2021, JET produced a five-second high-power nuclear fusion process for the first time, producing a record amount of fusion energy produced at the time. The first experiments with deuterium and tritium were already carried out on JET in 1997.

From major scientific milestones to record-setting fusion energy production, JET’s achievements highlight the device’s lasting legacy in the development of fusion technology. JET ended its operations at the end of December 2023.