Energy: An Off-the-Shelf Stellarator: Fast Prototyping Revives a 70-Year-Old Fusion Reactor Design

FOR A MACHINE that's designed to replicate a star, the world's newest stellarator is a surprisingly humble-looking apparatus. The kitchen-table-size contraption sits atop stacks of bricks in a cinder-block room at the Princeton Plasma Physics Laboratory (PPPL) in Princeton, N.J., its parts hand-labeled in marker. The PPPL team invented this nuclear-fusion reactor, completed last year, using mainly off-the-shelf components. Its core is a glass vacuum chamber surrounded by a 3D-printed nylon shell that anchors 9,920 meticulously placed permanent rare-earth magnets. Sixteen copper-coil electromagnets resembling giant slices of pineapple wrap around the shell crosswise.