"Magnetic Reconnection: Past, Present, Future, and a New FLARE Facility" 

Presented by Dr. Hantao Ji, Professor, from Princeton University

Magnetic reconnection has been regarded as one of most fundamental physical processes in space and astrophysics responsible for explosive release of magnetic energy to particles. It plays a pivotal role in electron and ion heating, particle acceleration to high energies, energy transport, and self-organization. The relevant phenomena range from solar flares, coronal heating, solar wind interactions with planets’ magnetospheres including Earth’s, star formation in molecular clouds, to explosions on magnetars and pulsars including Crab Nebula, as well as to disruptive phenomena in laboratory fusion plasmas. The first part of this talk concisely reviews the history of magnetic reconnection research starting from solar flares since 1950s, summarizes the status of our current understanding, and provides an outlook into the future to solve the reconnection problem.

The second part of this talk will introduce a new collaborative research facility, FLARE (Facility for LAboratory Reconnection Experiments; www.pppl.gov/FLARE) as an experimental platform for the study of magnetic reconnection in the multiple X-line regimes in the reconnection phase diagram [1,2], directly relevant to space, solar, astrophysical, and fusion plasmas. FLARE will allow us to perform controlled reconnection experiments at parameters never available before in the laboratory. Funded by NSF, the device was originally constructed and tested on the main campus of Princeton University. Funded by DoE and Princeton University, the FLARE device has been relocated to and installed at Princeton Plasma Physics Laboratory (PPPL) with a full set of initial diagnostics and an upgraded set of power supplies and infrastructure required to provide access to new regimes of magnetic reconnection. The first plasmas were successfully generated on April 14, 2025 and initial operations began on June 1, 2025 at PPPL. The capabilities of the facility and its initial plan will be presented in preparation for its establishment as a DoE collaborative research facility.

[1] H. Ji and W. Daughton, Physics of Plasmas 18, 111207 (2011).

[2] H. Ji, W. Daughton, J. Jara-Almonte, A. Le, A. Stanier, J. Yoo, Nature Reviews Physics 4, 263 (2022).