Physicists at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) are building a “star in a jar” — a miniature version of the how our Sun creates energy through fusion. It could provide humankind with near limitless energy, ending dependence on fossil fuels for generating electricity — without contributing greenhouse gases that warm the Earth, and with no long-term radioactive waste.
But that requires a “jar” that can contain superhot plasma — and is low-cost enough to be built around the world. A model for such a “jar,” or fusion device, already exists in experimental form: the tokamak, or fusion reactor. Invented in the 1950s by Soviet physicists, it’s a device that uses a powerful magnetic field to confine plasma (superhot charged gas) in the shape of a torus.