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Magnetic Reconnection: A bridge to Plasma Kinetic Scales

Twopanel fig

Hierarchical break-up of plasma current sheets to form magnetic flux-ropes. Initially at collisional macro-scales (top) and then evolving finer filaments at micro-scales (bottom).

Science Achievement       

Researchers from Los Alamos National Laboratory (LANL) used Cori to show that magnetic reconnection in a collisional plasma current sheet generates electric forces that overcome the collisional friction, leading to the spontaneous formation of current sheets and magnetic flux-ropes at the kinetic micro-scales.


A key science question for solar flares – the largest explosions in the solar system - concerns how magnetic energy is released into plasma kinetic energy, and how energy is transferred from large magnetic field structures down to the micro-scales where it is dissipated. This study demonstrates that magnetic reconnection can act as a bridge to access these micro-scales. The kinetic current layers that form are smaller than can be detected by present day spacecraft missions.

Research Details

  • The simulation used the Vector Particle-In-Cell (VPIC) code that solves the plasma kinetic equations with a Fokker-Planck collision operator.
  • It contained 6.5 billion cells and 1.8 trillion particles, taking 15 million NERSC hours on Cori.
  • The Cori Burst Buffer was crucial for simulation checkpointing and I/O of 100’s of TB of simulation data.

Related Links

Stanier et al., Physics of Plasmas 26, 072121 (2019).

doi: 10.1063/1.5100737

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