Neon gives healthy glow to reactor

Doughnut-shaped magnetic-fusion reactors known as tokamaks routinely reach the enormous temperature and density needed to fuse nuclei of hydrogen atoms. However, eddies in the fuel—a gas of hydrogen ions and electrons known as a plasma—spirit the energy away from the heart of the fusion furnace too quickly for a sustained reaction to take hold. Largely because of such turbulence, no fusion reactor has so far produced more energy than it has consumed, scientists say.