PPPL designing experiment to understand magnetic reconnection

A new experiment, the Facility for Laboratory Reconnection Experiment, is being designed at the Princeton Plasma Physics Laboratory to further scientists’ understanding of magnetic reconnection, a process relevant to both astrophysical plasmas and plasmas within fusion reactions.

PPPL Director Stewart Prager said the PPPL will host FLARE and operate it during its research phase as well as contribute technical staff and researchers. He noted the experiment is set to be completed in 2016.

“This is a terrific opportunity. It will be an extremely important experiment for astrophysics,” Prager said. “It exactly lines up with the mission of the laboratory, to develop our understanding of plasma physics.”

This $4.3 million project will be funded by a grant from the National Science Foundation and by University funds. Although the project uses PPPL facilities, it is overseen by the astrophysics department and will not be constrained by the $6 million cut to the PPPL budget for fiscal year 2014, astrophysics professor and principal FLARE investigator Hantao Ji explained.

Magnetic reconnection refers to the breaking and reconnecting of oppositely directed magnetic fields, allowing the dissipation of magnetic energy in plasmas (MRX documentation). An astrophysical plasma is a plasma, or ionized gas, whose physical properties are studied in astrophysics, and a fusion reaction is a reaction in which two light atomic nuclei fuse together to form a heavier nucleus.

FLARE was based on the success of the PPPL’s Magnetic Reconnection Experiment, Ji said. He explained that physicists have hypothesized that as the same physical principles apply to both systems, plasmas beyond a certain size can be used to study the processes occurring in much larger astrophysical plasmas. While MRX cannot access the regime of plasmas, FLARE will be large enough to test this hypothesis.

“Without access to that new regime, we never know if we are right or wrong. That’s why we are motivated,” Ji said. “That’s our job — to make correct theories, to understand what’s going on in nature and in fusion plasmas.”

Ji noted that 40 research groups have signed up for potential use of the FLARE experiment after its completion. He explained that because the design of FLARE is based on that of MRX, which had a successful run for about 20 years, FLARE is likely to produce reliable results.

An understanding of this phenomenon and its consequences will allow physicists to better confine plasmas within fusion reactors, which may be disrupted by reconnection, Ji explained. He added that FLARE will be a collaboration with the University of Rochester and the University of Wisconsin, where experiments are also being done to explore this regime using different methods of plasma production.

Knowledge gained from FLARE will help scientists to explain astrophysical phenomena both inside and outside of the solar system, Ji said. He noted that knowledge gained through FLARE can allow scientists to predict the presence of magnetic storms in the earth’s magnetosphere that can damage satellite communication. FLARE can also allow scientists to predict star formation within the universe, as magnetic reconnection must occur within a collapsing molecular cloud in order for a new star to be born.

“It will be a unique facility in the world,” he said. “It will attract collaborators from all over outside of Princeton, in the U.S. and abroad: experimentalists, theoretical physicists and astrophysicists.”

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