JET’s final tritium experiments yield new energy record

The Joint European Torus (JET), one of the world’s largest and most powerful fusion machines, has announced today the demonstration of the ability to reliably generate fusion energy, whilst simultaneously setting a world-record in energy output.

These notable accomplishments represent a significant milestone in the field of fusion science and engineering.

Throughout JET’s final deuterium-tritium experiments (DTE3), fusion power was consistently produced for 5.2 seconds, resulting in a ground-breaking record of 69.26 megajoules using a mere 0.21 milligrams of fuel.

JET is a tokamak, a design which uses powerful magnetic fields to confine a plasma in the shape of a doughnut.

Dr Fernanda Rimini, JET Senior Exploitation Manager, JET Scientific Operations Leader, said: “We can reliably create fusion plasmas using the same fuel mixture to be used by commercial fusion energy powerplants, showcasing the advanced expertise developed over time.”

Most approaches to creating commercial fusion favour the use of two hydrogen variants – deuterium and tritium. When deuterium and tritium fuse together they produce helium and vast amounts of energy – a reaction that will form the basis of future fusion powerplants.

Professor Ambrogio Fasoli, Programme Manager (CEO) at EUROfusion, said, “Our successful demonstration of operational scenarios for future fusion machines like ITER and DEMO, validated by the new energy record, instil greater confidence in the development of fusion energy. Beyond setting a new record, we achieved things we’ve never done before and deepened our understanding of fusion physics.”

Emmanuel Joffrin, EUROfusion Tokamak Exploitation Task force Leader from CEA, said: “Not only did we demonstrate how to soften the intense heat flowing from the plasma to the exhaust, but we also showed in JET how we can get the plasma edge into a stable state thus preventing bursts of energy reaching the wall. Both techniques are intended to protect the integrity of the walls of future machines. This is the first time that we've ever been able to test those scenarios in a deuterium-tritium environment.”

Over 300 scientists and engineers from EUROfusion – a consortium of researchers across Europe, contributed to these landmark experiments at the UK Atomic Energy Authority (UKAEA) site in Oxford, showcasing the unparalleled dedication and effectiveness of the international team at JET.

The results solidify JET’s pivotal role in advancing safe, low-carbon, and sustainable fusion energy.

Bruno Soares Gonçalves, President of IPFN says: “This result demonstrates that we are on the right path towards realizing the use of nuclear fusion to produce clean and safe electricity. The Portuguese researchers of IPFN/IST have actively contributed to this objective through their participation in the consortium Eurofusion, the exploration of JET and the construction of ITER. We are witnessing a renaissance of nuclear fusion with many new ideas being tested and private and public investment to leverage innovation in the area. “This excellent result shows the efforts of the European fusion community to contribute to decarbonization objectives, despite the challenges we still face to reach the construction of the first experimental reactor to demonstrate the production of electric energy.”

JET has been instrumental in advancing fusion energy for over four decades, symbolising international scientific collaboration, engineering excellence, and the commitment to harness the power of fusion energy – the same reactions that fuel the Sun and stars.

JET demonstrated sustained fusion over five seconds at high power and set a world-record in 2021. JET’s first deuterium-tritium experiments took place in 1997.

As it transitions into the next phase of its life cycle for repurposing and decommissioning, a celebration in late February 2024 will honour its founding vision and the collaborative spirit that has driven its success.

The achievements at JET, from the major scientific milestones to the setting of energy records, underscore the facility’s enduring legacy in the evolution of fusion technology.

Its contributions to fusion science and engineering have played a crucial role in accelerating the development of fusion energy, which promises to be a safe, low carbon and sustainable part of the world’s future energy supply.