Researchers led by Chang Liu of PPPL have unveiled a promising approach to mitigating damaging runaway electrons created by disruptions in tokamak fusion devices. Key to the approach was harnessing a unique type of plasma wave that bears the name of astrophysicist Hannes Alfvén, a 1970 Nobel laureate. Alfvén waves have long been known to loosen the confinement of high-energy particles in tokamak reactors, allowing some to escape and reducing the efficiency of the doughnut-shaped devices.