It took 1.1 million construction hours, but the Max Planck Institute for Plasma Physics is finally ready to turn on the world’s biggest “stellarator”, a type of nuclear fusion machine.
Fusion generates an immense amount of clean power, and could potentially solve the current problems related to resource consumption and mitigate the possibility of a shortage in the future. Before the end of the month, it will be clear whether that goal is currently attainable.
The stellarator is just 52 feet (16 metres) wide, but the machines are extremely difficult to construct, and only a few have ever been built before (although more have tried and failed). The project encountered some major roadblocks that nearly derailed it altogether; for instance, one of the companies contracted to work on the project went out of business during construction.
Nuclear reactor machines heat matter to such high temperatures that the electrons have enough energy to break away from their atoms, forming ions (particles with a positive or negative charge). The ions bounce around their container where they will bump into each other, fuse together, and release energy. That is the same process that the sun uses to generate energy.
Another nuclear fusion machine, the tokamak, is much more common and easy to built than stellarators. As Jessica Orwig reports on Science Alert, there are actually over thirty tokamaks being used around the world and have been widely considered superior to stellarators. However, there is a significant difference that will make stellarators better at generating clean power, and also importantly, to generate power in a way that is convenient to fit into the current grid.
Any nuclear fusion reaction machine needs to be able to control the super-heated matter, called plasma, to released the electrons and generate energy. Tokamaks control the plasma in shorter bursts because of the way internal coils are configured, and it takes more energy to heat the plasma than it ultimately generates. That makes stellarators the true potential source of energy replacement on a large scale.
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