“Most British people don’t know that their Government has started a Manhattan Project,” says Michael Cole, a plasma physicist and author of a history of fusion energy. “It is an engineering project on the same scale.”

I’ve come to see it for myself, but as my train slows to a halt at what feels like a branch-line station that Richard Beeching forgot to close, it’s hard to believe.

Culham railway station is as quiet as the Adlestrop of Edward Thomas’s melancholy poem, in which there’s nothing but “willow-herb … and all the birds of Oxfordshire”.

But just behind the hedges is Britain’s Los Alamos: the Centre for Fusion Energy.

Spread across a sprawling industrial park more than 160 acres, it is home to some 2,600 scientists and engineers busy trying to tame atoms. The project, some believe, is as ambitious as Robert Oppenheimer’s in New Mexico.

“There’s enough energy potential in a glass of seawater to light up a city,” says Mark Thomas, the chief executive of First Light Fusion.

Read more: Britain races against the world to unlock energy’s holy grail