General formulation for magnetohydrodynamic wave propagation, fire-hose, and mirror instabilities in Harris-type current sheets

Journal Article · Fri Feb 15 00:00:00 EST 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4789383· OSTI ID:22113418

Hau, L. -N. ^[1]; Lai, Y. -T. ^[1]

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1. Institute of Space Science, National Central University, Jhongli, Taiwan (China)

Harris-type current sheets with the magnetic field model of B-vector=B{sub x}(z)x-caret+B{sub y}(z)y-caret have many important applications to space, astrophysical, and laboratory plasmas for which the temperature or pressure usually exhibits the gyrotropic form of p{r_reversible}=p{sub Parallel-To }b-caretb-caret+p{sub Up-Tack }(I{r_reversible}-b-caretb-caret). Here, p{sub Parallel-To} and p{sub Up-Tack} are, respectively, to be the pressure component along and perpendicular to the local magnetic field, b-caret=B-vector/B. This study presents the general formulation for magnetohydrodynamic (MHD) wave propagation, fire-hose, and mirror instabilities in general Harris-type current sheets. The wave equations are expressed in terms of the four MHD characteristic speeds of fast, intermediate, slow, and cusp waves, and in the local (k{sub Parallel-To },k{sub Up-Tack },z) coordinates. Here, k{sub Parallel-To} and k{sub Up-Tack} are, respectively, to be the wave vector along and perpendicular to the local magnetic field. The parameter regimes for the existence of discrete and resonant modes are identified, which may become unstable at the local fire-hose and mirror instability thresholds. Numerical solutions for discrete eigenmodes are shown for stable and unstable cases. The results have important implications for the anomalous heating and stability of thin current sheets.

• OSTI ID: 22113418
• Journal Information: Physics of Plasmas, Vol. 20, Issue 2; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASTROPHYSICS
CUSPED GEOMETRIES
EIGENFUNCTIONS
EIGENVALUES
ELECTRON TEMPERATURE
HYDROMAGNETIC WAVES
ION TEMPERATURE
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MIRRORS
NUMERICAL SOLUTION
PLASMA
PLASMA HEATING
PLASMA INSTABILITY
PLASMA PRESSURE
STABILITY
WAVE EQUATIONS
WAVE PROPAGATION