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JET Final D-T Campaign (2023)

The Joint European Torus’s farewell deuterium-tritium experiments in late 2023 — setting a new world record of 69 MJ of fusion energy and providing critical data for ITER before JET’s permanent shutdown.

Reviewed Last reviewed: 9 Aug 2026 · Category: History & Milestones

The Campaign

In October–December 2023, the Joint European Torus (JET) at Culham, UK, conducted its final deuterium-tritium experiments before permanent shutdown. The campaign produced 69.26 MJ of fusion energy over a single pulse — a new world record for any fusion device, more than doubling JET’s own 1997 record of 21.7 MJ.[1]

69 MJ record pulse: The record shot sustained 12.5 MW of fusion power for about 5.5 seconds. While the peak power was lower than the 16.1 MW achieved in 1997, the sustained energy output was far higher, demonstrating the improved wall conditioning and plasma control possible with JET’s ITER-Like Wall (tungsten divertor, beryllium first wall).

ITER Relevance

JET was the only tokamak in the world capable of operating with tritium and with plasma-facing materials identical to ITER’s. The final campaign provided essential data on: tritium retention and removal in a tungsten-beryllium environment; isotope effects on plasma confinement; alpha-particle heating; and disruption mitigation with the shattered pellet injection system planned for ITER.[2]

Legacy

JET operated from 1983 to 2023 — 40 years as Europe’s flagship fusion experiment and the world’s most powerful tokamak. Its decommissioning is itself a significant project, providing experience in dismantling an activated fusion device that will be valuable for future reactor end-of-life.[3]

Sources

  1. Maslov, M. et al. "JET DTE3: record energy and scientific advances." EUROfusion press release, February 2024.
  2. Joffrin, E. et al. "Overview of the JET results in support to future ITER operation." Nuclear Fusion, 59, 112021, 2019.
  3. UKAEA. "JET: 40 Years of Fusion." gov.uk/ukaea, 2023.

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