Researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have developed a detailed model of the source of a puzzling limitation on fusion reactions. The findings, published in June in Physics of Plasmas, complete and confirm previous PPPL research and could lead to steps to overcome the barrier if the model proves consistent with experimental data. “We used to have correlation,” said physicist David Gates, first author of the paper. “Now we believe we have causation.” This work was supported by the DOE Office of Science.

Magnetic reconnection in the Earth and sun's atmospheres can trigger geomagnetic storms that disrupt cell phone service, damage satellites and blackout power grids. Understanding how reconnection transforms magnetic energy into explosive particle energy has been a major unsolved problem in plasma astrophysics.