The Stellerator is Online!

On 10 December, Germany’s new Wendelstein 7-X stellarator was fired up for the first time, rounding off a construction effort that took nearly 2 decades and cost €1 billion. Initially and for the first couple of months, the reactor will be filled with helium—an unreactive gas—so that operators can make sure that they can control and heat the gas effectively. At the end of January, experiments will begin with hydrogen in an effort to show that fusing hydrogen isotopes can be a viable source of clean and virtually limitless energy. Here's a feature we ran on the machine earlier this year:

  Science