Wibbly-wobbly magnetic fusion stuff: The return of the stellarator

Max Planck Institute for Plasma Physics

Fusion powers the Sun, where hydrogen ions are forced together by the high pressure and temperature. The nuclei join to create helium and release a lot of energy in the process. Doing the same thing on Earth means creating the same conditions that drive hydrogen nuclei together, which is easier said than done. Humans are very clever, but achieving fusion in a magnetic bottle will probably be one of our cleverer tricks. Making that bottle is difficult, and Ars recently had the chance to visit the people and facilities behind one of our most significant attempts at it.

For most people, magnetic bottles for fusion bring to mind the tokamak, a donut-shaped device that confines the plasma in a ring. But actually, the tokamak is just one approach; there’s a more complicated version that is helical in shape. Somewhere in between the two is the stellarator. Here, the required magnetic field is a bit easier to create than for a helix, but it’s still far more complicated than for a tokamak.