Physicists at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) have discovered valuable information about how electrically charged gas known as "plasma" flows at the edge inside doughnut-shaped fusion devices called "tokamaks."
The result partially corroborates past PPPL findings that the width of the heat exhaust produced by fusion reactions could be six times wider, and therefore less narrow, concentrated, and damaging, than had been thought.
Fusion, the power that drives the sun and stars, is the fusing of light elements in the form of plasma -- the hot, charged state of matter composed of free electrons and atomic nuclei -- that produces energy.
Scientists around the world are seeking to replicate fusion on Earth for a virtually inexhaustible supply of power to generate electricity.
The superhot plasma within tokamaks, which can reach hundreds of millions of degrees, is confined by magnetic fields that keep the plasma from the walls of the machines.
However, particles and heat can escape from the confinement fields at the "magnetic separatrix" -- the boundary between the magnetically confined and unconfined plasmas.