How advanced materials could unleash fusion energy

It started like any other graduate-level class. Dennis Whyte wanted his students to work in teams and use advanced computational tools to crack a problem. This was a fusion engineering class though, and the problem he assigned was one that brilliant minds had been chipping away at for half a century: how to viably generate endless, clean energy by fusing atomic nuclei. But it was 2012, and a new kind of superconductor had just entered the market. Superconductors, materials that conduct electricity without electrical resistance, traditionally needed to be cooled to extremely low temperatures to become superconducting. The new ones worked at more practical temperatures. Magnets made from these high-temperature superconductors (HTSs) could produce the strong magnetic fields needed to sustain fusion reactions.Whyte challenged his class at the Massachusetts Institute of Technology to design a fusion reactor using HTS magnets. The results floored him. His students’ doughnut-shaped device—a design called a tokamak—produced, on paper, the same power as ITER, the massive 35-country fusion-energy project under construction in France, but at half the size and a fraction of the cost. “You take MIT graduate students, give them a hard problem and the tools to solve it, and they’re going to come up with really interesting solutions,” he says.In 2015, Whyte and others at MIT published the design for their fusion machine, which promised to be affordable, robust, and compact. Three years later, they founded a company called Commonwealth Fusion Systems (CFS). And 3 years after its launch, CFS demonstrated a magnet