先前的用于具有场对准流的不可压缩等离子体的稳定性条件（参见Throumoulopoulos和Tasso，Physics of Plasmas 14，122104（2007））被扩展到包括自引力的引力等离子体。结果表明，引力仅通过平衡值影响稳定性条件。
英文摘要：
A previous stability condition (see Throumoulopoulos and Tasso, Physics of Plasmas 14, 122104 (2007)) for incompressible plasmas with field aligned flows is extended to gravitating plasmas including self-gravitation. It turns out that the stability condition is affected by gravitation through the equilibrium values only.
We present a reduced magnetohydrodynamic (MHD) mathematical model describing the dynamical behavior of highly conducting plasmas with frozen-in magnetic fields, constrained by the assumption that, there exists a frame of reference, where the magnetic field vector, $\mathbf{B}$, is aligned with the plasma velocity vector, $\mathbf{u}$, at each point. We call this solution "stream-aligned MHD" (SA-MHD). Within the framework of this model, the electric field, $\mathbf{E} = -\mathbf{u} \times \mathbf{B} \equiv 0$, in the induction equation vanishes identically and so does the electromagnetic energ…
Braginskii MHD provides a more accurate description of many plasma environments than classical MHD since it actively treats the stress tensor using a closure derived from physical principles. Stress tensor effects nonetheless remain relatively unexplored for solar MHD phenomena, especially in nonlinear regimes. This paper analytically examines nonlinear damping and longitudinal flows of propagating shear Alfvén waves. Most previous studies of MHD waves in Braginskii MHD considered the strict linear limit of vanishing wave perturbations. We show that those former linear results only apply to Al…
Stationary field-aligned MHD flows at astropauses and in astrotails. Principles of a counterflow configuration between a stellar wind and its interstellar medium wind
According to magnetohydrodynamics (MHD), the encounter of two collisional magnetized plasmas at high velocity gives rise to shock waves. Investigations conducted so far have found that the same conclusion still holds in the case of collisionless plasmas. For the case of a flow-aligned field, MHD stipulates that the field and the fluid are disconnected, so that the shock produced is independent of the field. We present a violation of this MHD prediction when considering the encounter of two cold pair plasmas along a flow-aligned magnetic field. As the guiding magnetic field grows, isotropizatio…
Within the context of a viscoresistive magnetohydrodynamic (MHD) model with anisotropic heat transport and cross-field mass diffusion, we introduce novel three-term representations for the magnetic field (background vacuum field, field line bending and field compression) and velocity ($\vec E\times\vec B$ flow, field-aligned flow and fluid compression), which are amenable to three-dimensional treatment. Once the representations are inserted into the MHD equations, appropriate projection operators are applied to Faraday's law and the Navier-Stokes equation to obtain a system of scalar equations…
The generation of magnetohydrodynamic (MHD) waves and their instabilities are studied in galactic gaseous rotating plasmas with the effects of the magnetic field, the self gravity, the diffusion-convection of cosmic rays as well as the gas and cosmic-ray pressures. The coupling of the Jeans, Alfv{é}n and magnetosonic waves, and the conditions of damping or instability are studied in three different cases, namely when the propagation direction is perpendicular, parallel and oblique to the static magnetic field, and are shown to be significantly modified by the effects of the Coriolis force due …
The Equations of Reduced Magnetohydrodynamics in Dipole Coordinates
The Catholic University of America（美国天主教大学）；Geospace Physics Laboratory NASA Goddard Spaceflight Laboratory（NASA戈达德太空飞行中心地球空间物理实验室）；Department of Astronomy, University of Maryland, College Park（马里兰大学帕克分校天文学系）
Being motivated by the paper [O. I. Bogoyavlenskij, Phys. Rev. 66, 056410 (2002)] we generalise the symmetry transformations for MHD equilibria with isotropic pressure and incompressible flow parallel to the magnetic field introduced therein in the case of respective CGL equilibria with anisotropic pressure. We find that the geometrical symmetry of the field-aligned equilibria can break by those transformations only when the magnetic field is purely poloidal. In this situation we derive three-dimensional CGL equilibria from given axisymmetric ones. Also, we examine the generic symmetry transfo…
Astrophysical plasmas are often subject to both rotation and large-scale background magnetic fields. Individually, each is known to two-dimensionalize the flow in the perpendicular plane. In realistic flows, both of these effects are simultaneously present and, importantly, need not be aligned. In this work, we numerically investigate three-dimensional forced magnetohydrodynamic (MHD) turbulence subject to the competing effects of global rotation and a perpendicular background magnetic field. We focus on the case of a strong background field and find that increasing the rotation rate from zero…
Stationary Resistive MHD Solutions Near an Isolated Three-Dimensional Magnetic Null
Astronomical Institute, Czech Academy of Science（捷克科学院天文研究所）；Astronomical Institute, Faculty of Mathematics and Physics, Charles University（查理大学数学物理学院天文研究所）；Escuela de Ingeniería Civil, Universidad de Valparaíso（瓦尔帕莱索大学土木工程学院）
We derive a sufficient condition for the linear stability of plasma equilibria with incompressible flow parallel to the magnetic field, $\bf B$, constant mass density and anisotropic pressure such that the quantity $σ_d= μ_0(P_\parallel -P_\perp)/B^2$, where $P_\parallel$ ($P_\perp$) is the pressure tensor element parallel (perpendicular) to $\bf B$, remains constant. This condition is applicable to any steady state without geometrical restriction. The condition, generalising the respective condition for MHD equilibria with isotropic pressure and constant density derived in Throumoulopoulos & …
JOREK is a massively parallel fully implicit non-linear extended MHD code for realistic tokamak X-point plasmas. It has become a widely used versatile code for studying large-scale plasma instabilities and their control developed in an international community. This article gives a comprehensive overview of the physics models implemented, numerical methods applied for solving the equations and physics studies performed with the code. A dedicated section highlights some of the verification work done for the code. A hierarchy of different physics models is available including a free boundary and …
