For more than 60 years, scientists have dreamed of a clean, inexhaustible energy source in the form of nuclear fusion. And they’re still dreaming.
But thanks to the efforts of the Max Planck Institute for Plasma Physics, experts hope that might soon change. Last year, after 1.1 million construction hours, the institute completed the world’s largest nuclear fusion machine of its kind, called a stellarator.
They call this 16-metre (52-foot) wide machine the W7-X. And following more than a year of tests, engineers are finally ready to fire up the US$1.1 billion machine for the first time, and it could happen before the end of this month, Science reported.
The black horse of nuclear reactors
Known in the plasma physics community as the 'black horse' of nuclear fusion reactors, stellarators are notoriously difficult to build. This video below demonstrates the construction of W7-X, which took 19 years to complete:
etween 2003 and 2007, as the project was being built, it suffered some major construction set backs — including one of its contracted manufacturers going out of business — that nearly cancelled the whole endeavour.
Only a handful of stellarators have ever been attempted, and even fewer have been completed.
By comparison, the more popular cousin to the stellarator, called a tokamak, is in wider use. There are over three dozen operational tokamaks across the globe, and more than 200 built throughout history. These machines are easier to construct and, in the past, have proven to do the job of a nuclear reactor better than the stellarator.
But tokamaks have a major flaw that W7-X is reportedly immune to, suggesting that Germany’s latest monster machine could be a game-changer.
If W7-X succeeds, it could completely turn the nuclear fusion community on its head and launch stellarators into the lime light.
“The world is waiting to see if we get the confinement time and then hold it for a long pulse,” David Gates, the head of stellarator physics at the Princeton Plasma Physics Laboratory, told Science.
Full source: http://www.sciencealert.com/ 
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Nuclear Game Changer: Germany switches on a revolutionary nuclear fusion machine W7-XAge: 3 weeks
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