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Title: Mirror Instability in the Turbulent Solar Wind

Abstract

The relationship between a decaying strong turbulence and the mirror instability in a slowly expanding plasma is investigated using two-dimensional hybrid expanding box simulations. We impose an initial ambient magnetic field perpendicular to the simulation box, and we start with a spectrum of large-scale, linearly polarized, random-phase Alfvénic fluctuations that have energy equipartition between kinetic and magnetic fluctuations and a vanishing correlation between the two fields. A turbulent cascade rapidly develops, magnetic field fluctuations exhibit a Kolmogorov-like power-law spectrum at large scales and a steeper spectrum at sub-ion scales. The imposed expansion (taking a strictly transverse ambient magnetic field) leads to the generation of an important perpendicular proton temperature anisotropy that eventually drives the mirror instability. This instability generates large-amplitude, nonpropagating, compressible, pressure-balanced magnetic structures in a form of magnetic enhancements/humps that reduce the perpendicular temperature anisotropy.

Authors:
 [1]; ; ;  [2];  [3]
  1. Astronomical Institute, CAS, Bocni II/1401,CZ-14100 Prague (Czech Republic)
  2. Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze Largo E. Fermi 2, I-50125 Firenze (Italy)
  3. Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom)
Publication Date:
OSTI Identifier:
22661176
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 838; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALFVEN WAVES; ANISOTROPY; DECAY; EXPANSION; FLUCTUATIONS; INSTABILITY; MAGNETIC BALANCES; MAGNETIC FIELDS; MIRRORS; PLASMA; PROTON TEMPERATURE; PROTONS; SIMULATION; SOLAR WIND; SPECTRA; TURBULENCE; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Hellinger, Petr, Landi, Simone, Verdini, Andrea, Franci, Luca, and Matteini, Lorenzo, E-mail: petr.hellinger@asu.cas.cz. Mirror Instability in the Turbulent Solar Wind. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA67E0.
Hellinger, Petr, Landi, Simone, Verdini, Andrea, Franci, Luca, & Matteini, Lorenzo, E-mail: petr.hellinger@asu.cas.cz. Mirror Instability in the Turbulent Solar Wind. United States. doi:10.3847/1538-4357/AA67E0.
Hellinger, Petr, Landi, Simone, Verdini, Andrea, Franci, Luca, and Matteini, Lorenzo, E-mail: petr.hellinger@asu.cas.cz. Sat . "Mirror Instability in the Turbulent Solar Wind". United States. doi:10.3847/1538-4357/AA67E0.
@article{osti_22661176,
title = {Mirror Instability in the Turbulent Solar Wind},
author = {Hellinger, Petr and Landi, Simone and Verdini, Andrea and Franci, Luca and Matteini, Lorenzo, E-mail: petr.hellinger@asu.cas.cz},
abstractNote = {The relationship between a decaying strong turbulence and the mirror instability in a slowly expanding plasma is investigated using two-dimensional hybrid expanding box simulations. We impose an initial ambient magnetic field perpendicular to the simulation box, and we start with a spectrum of large-scale, linearly polarized, random-phase Alfvénic fluctuations that have energy equipartition between kinetic and magnetic fluctuations and a vanishing correlation between the two fields. A turbulent cascade rapidly develops, magnetic field fluctuations exhibit a Kolmogorov-like power-law spectrum at large scales and a steeper spectrum at sub-ion scales. The imposed expansion (taking a strictly transverse ambient magnetic field) leads to the generation of an important perpendicular proton temperature anisotropy that eventually drives the mirror instability. This instability generates large-amplitude, nonpropagating, compressible, pressure-balanced magnetic structures in a form of magnetic enhancements/humps that reduce the perpendicular temperature anisotropy.},
doi = {10.3847/1538-4357/AA67E0},
journal = {Astrophysical Journal},
number = 2,
volume = 838,
place = {United States},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}
}