• Scientists and engineers at world-leading UK Atomic Energy Authority’s Joint European Torus (JET) facility in Oxford will run its third and final experiments using tritium in its fuel mix
  • The deuterium-tritium experiments will focus on the necessary scientific and engineering for operating future fusion machines, such as ITER, STEP and DEMO
  • JET is to end scientific operations after 40 years on 31 December 2023 for repurposing and decommissioning
  • Weekly updates on experimental outcomes available on social media

 The start of the final deuterium-tritium experiments at the Joint European Torus (JET) take place today at the UK Atomic Energy Authority (UKAEA) in Culham, Oxfordshire.

JET is currently the world’s largest and most powerful operational tokamak, and the only machine able to operate with tritium within its fuel mix. It is operated by UKAEA and collectively used by all European fusion laboratories within the EUROfusion consortium.

The planned deuterium-tritium experiments, also known as ‘DTE3’, intend to run for seven weeks and focus on three areas:

  1. Plasma science
  2. Materials science
  3. Neutronics

DTE3 will see 36 experiments aim to reduce the heat load on the divertor exhaust system by injecting impurities into the plasma without compromising performance; use a diagnostic method called ‘laser induced desorption’ to measure the amount of tritium in the surface of the wall materials; improve real-time control of the plasma heat load; and understand the impact of bombarding neutrons on in-vessel materials, electronic components and data acquisition systems.

The third and final deuterium-tritium experiments come just 20 months after JET clearly demonstrated sustained fusion over five seconds at high power and set a world-record. JET’s first deuterium-tritium experiment took place in 1997.

JET’s research findings are critical to the development of ITER, the larger and more advanced version of JET. ITER is a fusion research mega-project supported by seven members – China, the European Union, India, Japan, Korea, Russia and the USA – based in the south of France, to further demonstrate the scientific and technological feasibility of fusion energy.

As well as ITER, the research findings have important implications for the UK’s STEP prototype powerplant to be built at West Burton, Nottinghamshire, the European DEMO prototype fusion plant, and other national laboratory and private projects around the world.

Joelle Mailloux, JET Science Programme Leader at UKAEA, said: “There has been real excitement ahead of the start of the DTE3 campaign and about the opportunity to study areas of science important to the design and operation of the next generation of fusion machines. The DTE3 programme is based on decades of research and, with the DTE2 results, will play a vital part in shaping the future of fusion.”

Penny Middleton, Head of JET Operations at UKAEA, added: “This really is a team effort and relies on the collaborative efforts of hundreds of scientists, engineers, technicians, health physicists, IT experts and other support personnel from diverse backgrounds and nationalities. Their collective effectiveness and thorough planning aim to deliver a set of experiments that will contribute to the development of fusion energy. The pressures and workload are intense for everyone involved but there is also a real sense of pride and commitment among the team to deliver the best outcomes possible.”

Emmanuel Joffrin, Task Force Leader of the Tokamak Exploitation EUROfusion Task Force said: “This new DT campaign (DTE3) represents the culmination of several years of cooperative research within the EUROfusion consortium programme. Europe’s integrated approach to fusion research and innovation is bringing together researchers and knowledge from a number of European tokamaks in a common goal and comprehensively address the challenges ahead to realise fusion energy, as outlined in our strategic roadmap.  With the DTE3 experiments we will provide much needed input to the future operation of ITER and fusion powerplants, testing all the elements in an integrative manner.  We are very excited and look forward to the results of this last round of DT experiments.”

JET will be move on to the next phase of its life cycle in early 2024 for repurposing and decommissioning, which will last until c.2040.

A celebration to mark JET’s contribution to fusion science and engineering over the decades will be held in early 2024.

JET has played a critical 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.

UKAEA will be publishing regular updates from DTE3 across its digital channels.