Germany has fired up a potentially revolutionary fusion reactor

On Thursday, the Max Planck Institute for Plasma Physics fired up a monster machine that it hopes will change the world. The machine is called the Wendelstein 7-X, or W7-X for short. It’s a type of nuclear-fusion machine called a stellarator and is the largest, most sophisticated of its kind. Nuclear fusion could prove to be a clean, inexhaustible energy source. But humans are still a ways from successfully building a reactor that could power a small town, let alone entire cities. But now, we’re one step closer. On Thursday, the Max Planck Institute for Plasma Physics tweeted out a beautiful image of the machine’s first plasma (shown below) — a gas in which all the electrons have been stripped from their atoms, a task that requires tremendous amounts of energy and is critical to achieving nuclear fusion. The key to a successful nuclear-fusion reactor of any kind is to generate, confine, and control plasma. This is the first confirmation that the machine is performing as planned. Last year, after 1.1 million construction hours, the Max Planck Institute for Plasma Physics completed construction of the $1.1 billion W7-X.