A cutaway view of the proposed ARC reactor. Thanks to powerful new magnet technology, the much smaller, less-expensive ARC reactor would deliver the same power output as a much larger reactor. Credit: the MIT ARC team ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- It's an old joke that many fusion scientists have grown tired of hearing: Practical nuclear fusion power plants are just 30 years away—and always will be. But now, finally, the joke may no longer be true: Advances in magnet technology have enabled researchers at MIT to propose a new design for a practical compact tokamak fusion reactor—and it's one that might be realized...