Joint European Torus significant event fusion experiment on 21 December 2021
Post-Brexit
Brexit threw the plans for JET in doubt. As part of its plan to leave the EU, the UK was to leave Euratom, which provides the funding for JET. Talks on the funding after 2018, when the 5-year plan expired, commenced and a new agreement to extend JET's operation until 2019 or 2020 appeared to be largely complete. These talks were put on hold after the Brexit announcement. However, in March 2019, the UK Government and European Commission signed a contract extension for JET. This guaranteed JET operations until the end of 2024 regardless of Brexit situation. In December 2020, a JET upgrade commenced using tritium, as part of its contribution to ITER. On 21 December 2021, JET produced 59 megajoules using deuterium-tritium fuel while sustaining fusion during a five second pulse, beating its previous record of 21.7 megajoules with Q = 0.33, set in 1997.