Magnetic reconnection can trigger geomagnetic storms that disrupt cell phone service, damage satellites and black out power grids. But how reconnection, in which the magnetic field lines in plasma snap apart and violently reconnect, transforms magnetic energy into explosive particle energy remains a major unsolved problem in plasma astrophysics. Magnetic field lines represent the direction, and indicate the shape, of magnetic fields.
Now scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have taken a key step toward a solution, as described in a paper published this week in the journal Nature Communications. In research conducted on the Magnetic Reconnection Experiment (MRX) at PPPL, the scientists not only identified how the mysterious transformation takes place, but measured experimentally the amount of magnetic energy that turns into particle energy.
The investigation showed that reconnection converts about 50 percent of the magnetic energy, with one-third of the conversion heating the electrons and two-thirds accelerating the ions — or atomic nuclei — in the plasma. In large bodies like the sun, such converted energy can equal the power of millions of tons of TNT.