The Joint European Torus fusion reactor EUROfusion/CC BY 4.0

Within months researchers will attempt to create a ball of plasma hotter than the sun inside a doughnut-shaped machine in south-east England. It will be the country’s first nuclear fusion operation since the last century.

The attempt in November to fuse two forms of hydrogen at the Joint European Torus (JET) in Culham, Oxfordshire, will be the first since the facility broke the then record for nuclear fusion power production for less than a second in 1997.

“Humans don’t do this very often,” says Howard Wilson at the University …