A key challenge in fusion research is maintaining the stability of the hot, charged plasma that fuels fusion reactions inside doughnut-shaped facilities called “tokamaks.” Physicists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), have recently found that drifting particles in the plasma, which consists of free electrons and atomic nuclei, can forestall instabilities that reduce the pressure crucial to high-performance fusion reactions inside these facilities.