Nuclear fusion world record a promising step toward limitless energy


In its last hurrah before being shut down, a 40-year-old fusion reactor in the UK set a new world record for energy output — bringing the decades-old promise of clean, limitless energy one step closer to reality.

Scientists at the Joint European Torus (JET) — a huge, donut-shaped machine known as a tokamak — produced a record 69 megajoules of fusion energy for five seconds, surpassing the previous record of 59 megajoules set in 2021. This equates to a power output of 12.5 megawatts, enough to power around 12,000 households.  

The UK’s nuclear minister Andrew Bowie called the latest breakthrough a “fitting swansong” for JET, which concluded its scientific operations at the end of December 2023. 

Over 300 scientists and engineers from EUROfusion, a consortium of researchers across Europe, contributed to the landmark experiments at the former nuclear fusion test site in Oxford

Professor Ambrogio Fasoli, programme manager at EUROfusion, said the new energy record “instills greater confidence” in future fusion machines like ITER, a €22bn fusion reactor currently under construction in France. 

“Beyond setting a new record, we achieved things we’ve never done before and deepened our understanding of fusion physics,” said the Italian physicist.  

The experiment was attained using just 0.2 milligrams of deuterium-tritium fuel. The tokamak takes these hydrogen isotopes and heats them to temperatures hotter than the Sun so that their nuclei fuse together, releasing huge amounts of energy

When running, the machine reached temperatures of 150 million°C — temporarily making it the hottest point in our solar system. 

Why is JET being shutdown?

In 1958 when US WWII research on fusion was declassified it sent Russia, UK, Europe, Japan, and the US on a race to develop fusion for energy production.  

The Brits and the Europeans decided to team up and thus, JET was born. The reactor was first commissioned in 1983 and set its first fusion energy record in 1997.

JET remained the world’s most advanced experimental fusion reactor ever made before it was shut down. Its experiments were critical to the development of ITER and other planned fusion devices

The UK and EUROfusion announced that they would close JET this year back in 2016, with the hope that ITER would already be up and running.