Many machines over the past 60 years have been billed as the one that will make the big breakthrough in fusion science, only to stumble. This one could be different.

Some people have spent their whole working lives researching fusion and then retired feeling bitter at what they see as a wasted career. But that hasn’t stopped new recruits joining the effort every year: optimistic young graduates keen to get to grips with a complicated scientific problem that has real implications for the world. Their numbers have been increasing in recent years, perhaps motivated by two factors: there is a new machine under construction, a huge global effort that may finally show that fusion can be a net producer of energy; and the need for fusion has never been greater, considering the twin threats of dwindling oil supplies and climate change.

The new machine is the International Thermonuclear Experimental Reactor, or simply ITER (pronounced ‘eater’). Many machines over the past 60 years have been billed as ‘the one’ that will make the big breakthrough, only to stumble before getting there. But considering how close JET, its direct predecessor, got to break-even, ITER has to have a good chance. ITER is not a power station, it won’t be connected to the grid and won’t even generate any electricity, but its designers are aiming to go far beyond break-even and spark enough fusion reactions to produce 10 times as much heat as that pumped in to make it work. To get there requires a reactor of epic proportions. The building containing the reactor will be 60m tall and extend 13m underground–altogether taller than the Arc de Triomphe. The reactor inside will weigh 23,000 tonnes–continuing the Parisian theme, that’s more than three Eiffel Towers.

Source: Daniel Clery |