Press release

Pioneering JET delivers final plasma

The groundbreaking fusion machine, Joint European Torus (JET), has finished its course of final experiments after 40 years.

The JET control room on the day of final plasma experiments - credit United Kingdom Atomic Energy Authority / EUROfusion

The Joint European Torus (JET) has performed its final experiments, marking the end of a 40-year era for the groundbreaking machine.

Some 40-and-a-half years after its first pulse on 25 June, 1983, JET delivered pulse number 105,842 on Tuesday 18 December, 2023.

UKAEA Chief Executive Officer, Prof Sir Ian Chapman, who was in attendance in JET’s Control Room for the final plasma experiment, said: “This is the final milestone in JET’s 40-year history. Those decades of research using JET by dedicated teams of scientists and engineers have played a critical role in accelerating the development of fusion energy.”

JET’s final day of plasma continued to push scientific boundaries, firstly attempting an inverted plasma shape for the first time at Culham before deliberately aiming electrons at the inner wall to improve understanding of beam control and damage mechanisms. The findings of these experiments will support the development of ITER.

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

UKAEA has set up the STEP programme to deliver a prototype fusion powerplant in Nottinghamshire, aiming for 2040.

Updates to this page

Published 20 December 2023