Electron-only reconnection and inverse magnetic-energy transfer at sub-ion scales
ORAL · Invited
Abstract
Electron-only reconnection is a form of magnetic reconnection that occurs within sufficiently small spatial regions, where ions are effectively decoupled from the reconnection dynamics. In this study, we derive and numerically validate an analytical model for electron-only magnetic reconnection in a merging island configuration. The model predicts reconnection rates at sub-ion scales that are significantly higher than those associated with magnetohydrodynamic (MHD) scale reconnection, in agreement with recent observations and kinetic simulations. We further apply this model to investigate inverse magnetic energy transfer at sub-ion scales, deriving time-dependent scaling laws for magnetic energy decay that diverge from those found in the MHD regime. These scaling laws are validated through two- and three-dimensional numerical simulations, demonstrating that sub-ion scale magnetic structures can grow to system-scale via successive island coalescence. We also characterize the resulting plasma turbulence, examining the energy spectrum and the typical spatial dimensions of magnetic structures.
*This work was supported by DOE Awards DE-SC0022012, DE-FG02-91-ER54109, and by the Schmidt Futures at the Institute for Advanced Study. This work used resources of the Satori cluster at the MGHPCC facility funded by DOE award No. DE-FG02-91-ER54109, and the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 using NERSC award FES-ERCAP0020063.
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Publication:Liu, Zhuo, Caio Silva, Lucio M. Milanese, Muni Zhou, Noah R. Mandell, and Nuno F. Loureiro. "Electron-Only Magnetic Reconnection and Inverse Magnetic-Energy Transfer at Subion Scales." Physical Review Letters 134, no. 15 (2025): 155201.
