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JET is the world’s largest and most advanced tokamak.

Plasmas in JET are hotter than anywhere in the Solar System.

Operated by Culham Centre for Fusion Energy, the Joint European Torus (JET) is the focal point of the European fusion research programme.

JET was designed to study fusion in conditions approaching those needed for a power plant. It is the only experiment that can operate with the deuterium-tritium fuel mix that will be used for commercial fusion power.

Since it began operating in 1983, JET has made major advances in the science and engineering of fusion. Its success has led to the construction of the first commercial-scale fusion machine, ITER, and has increased confidence in the tokamak as a design for future fusion power plants.

JET was the first device to produce controlled fusion power with deuterium and tritium and holds the world record for fusion power. In recent years, JET has carried out much important work to assist the design and construction of ITER, its international successor, which is being built in France. After over 30 years of successful operation, JET remains at the forefront of fusion research – testing plasma physics, systems and materials for ITER.

JET Control Room
1978 JET construction starts
1983 First plasma in JET
1991 First experiments with tritium
1997 High performance full deuterium-tritium experiments. JET achieves world record fusion power of 16.1 MW.
2009 – 10 JET installs a new beryllium/tungsten plasma facing wall to test this configuration for ITER.
2019 – 20 Preparations well advanced for new deuterium-tritium experiments, designed to sustain high fusion performance for longer periods.

The JET facilities are collectively used by all European fusion laboratories under the EUROfusion consortium. About 350 scientists from EU countries (plus Switzerland, the UK and Ukraine), and more from around the globe, participate in JET experiments each year. CCFE is responsible for operating the facility for fusion researchers and for maintaining and upgrading it. This work is carried out under a contract between the European Commission and the UK Atomic Energy Authority (CCFE’s operator). This funds around 400 engineers and technical staff essential for operating and maintaining the device.

CCFE scientists also play a full part in running experiments on JET within the integrated European research programme co-ordinated by EUROfusion.

For more information about JET and the European fusion programme, please see the EUROfusion website.

What’s inside JET

Illustration of the interior of JET showing a plasma Illustration explaining components inside JET
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