Researchers at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory are harnessing the power of computers to enhance the performance of fusion devices known as stellarators.

Inside a large, ring-shaped device, plasma, reaching temperatures many times hotter than the surface of the sun, swirls in powerful, controlled motion. From the outside, the machine resembles a metal ring encased in scaffolding and walkways. But within, it’s recreating the extreme conditions necessary for nuclear fusion—the same process that powers the sun and all other stars.