New Paths to Fusion Energy
The National Spherical Torus Experiment Upgrade (NSTX-U) delivered important scientific results during its first research campaign prior to shutting down for repairs. The upgrade doubled the magnetic field strength, current, and heating power of its predecessor and made the NSTX-U the most powerful fusion facility of its kind.
Among the top puzzles in the development of fusion energy is the best shape for the magnetic facility -- or "bottle" -- that will provide the next steps in the development of fusion reactors. Leading candidates include spherical tokamaks, compact machines that are shaped like cored apples, compared with the doughnut-like shape of conventional tokamaks.
A key to producing good fusion reactions is controlling rotation of the ultra-hot plasma gas that swirls inside tokamaks and fuels the reactions. At PPPL, physicists Mario Podestà and Ron Bell have developed a real time velocity (RTV) diagnostic that could become part of a system for actively controlling the velocity of the rotation.
One of the more challenging obstacles to creating a “star in a jar” on Earth is finding a material that can contain and facilitate the massive amount of energy produced in a fusion device. PPPL scientists are experimenting with unique ways to cover the interior walls of fusion reactors that can handle the heat, absorb the battering of atomic collisions, and help produce energy.
