Frontiers in Astronomy and Space Sciences (Aug 2022)

Particle acceleration in an MHD-scale system of multiple current sheets

  • Masaru Nakanotani,
  • Gary P. Zank,
  • Gary P. Zank,
  • Lingling Zhao,
  • Lingling Zhao

DOI
https://doi.org/10.3389/fspas.2022.954040
Journal volume & issue
Vol. 9

Abstract

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We investigate particle acceleration in an MHD-scale system of multiple current sheets by performing 2D and 3D MHD simulations combined with a test particle simulation. The system is unstable for the tearing-mode instability, and magnetic islands are produced by magnetic reconnection. Due to the interaction of magnetic islands, the system relaxes to a turbulent state. The 2D (3D) case both yield −5/3 (− 11/3 and −7/3) power-law spectra for magnetic and velocity fluctuations. Particles are efficiently energized by the generated turbulence, and form a power-law tail with an index of −2.2 and −4.2 in the energy distribution function for the 2D and 3D case, respectively. We find more energetic particles outside magnetic islands than inside. We observe super-diffusion in the 2D (∼ t2.27) and 3D (∼ t1.2) case in the energy space of energetic particles.

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