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A new fusion energy record has been reached in a landmark JET experiment

​Scientists from the EUROfusion consortium, which the CEA (IRFM) participates in, recently recorded the production of 59 megajoules of fusion energy over several seconds at the world's only operational tokamak using deuterium and tritium: the Joint European Torus (JET) in the UK. In an environment very similar to that of ITER, they succeeded in piloting the fusion plasma according to their simulations. This brilliant demonstration confirms both the ITER project and the potential of fusion energy!

Published on 9 February 2022

In 2021, the JET produced 59 megajoules of fusion energy for 5 seconds, shattering its previous record from 1997 (21.7 megajoules).

Between these two records, the European tokamak underwent a significant transformation, which the CEA-IRFM actively participated in. In 2011, the carbon used in the interior walls and floor of the tokamak was replaced by beryllium and tungsten, since these elements absorb much less tritium than carbon. The JET configuration is now very close to that of ITER. This makes JET an essential test facility for the future international demonstrator, whose first plasmas are expected before 2030 and in 2035 for the deuterium-tritium mixture – ITER's volume being ten times larger than JET's.

For the first time since 1997, an experimental campaign involving deuterium and tritium (two isotopes of hydrogen) was conducted at JET by EUROfusion scientists, including about thirty researchers, engineers and technicians from the CEA-IRFM.

Utilizing the new JET wall that is similar to that of ITER in addition to new diagnostics, the project objective was to characterize the behavior of the fusion plasma and to prepare for piloting the future ITER fusion demonstrator. The mission was a success, with a good correspondence between simulations and observations within the maximum times accessible to JET. Indeed, JET is limited to durations of a few seconds because its inner wall is not actively cooled and the coils that produce the magnetic field for plasma confinement are not superconducting.

The CEA-IRFM's W Environment in Steady-State Tokamak (WEST), which has actively cooled tungsten walls and is equipped with superconducting coils, is a complementary test bench to JET in preparation for ITER operation. Indeed, WEST will very soon explore deuterium plasma production times (without tritium) lasting several minutes, as will be the case for ITER.

Bernard Bigot, Director-General of ITER

"A deuterium-tritium fusion experiment sustained over several seconds at this power level – almost on an industrial scale – provides an irrefutable confirmation to all those involved in the global quest for fusion. For the ITER project, the JET results are a vote of confidence that we are on the right track to demonstrating the potential of fusion energy."
The EUROfusion consortium brings together 4,800 experts, students and researchers from all over Europe with research funded by the European Commission.

ITER brings together seven partners: China, the European Union, India, Japan, South Korea, Russia and the United States. The future demonstrator is under construction at Cadarache.

Click here to read the press release (in French).

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