论文标题
碰撞磁化等离子体的对称传输系数
Symmetric set of transport coefficients for collisional magnetized plasma
论文作者
论文摘要
在Braginskii扩展的磁氢动力学（EXMHD）中，适用于碰撞的天体物理和高能密度等离子体，电场和热流量由$α$，$β$和$κ$传输系数描述。我们表明，磁性传输主要依赖于$β_\ Parallel-β_\ perp $和$α_\ perp-α_\并行$，而不是$α_\ perp $和$β_\ perp $本身。但是，常用系数拟合功能[Epperlein和Haines，Phys。流体29，1029（1986）]无法准确计算这些数量。这意味着许多EXMHD模拟显着高估了交叉梯度的Nernst对流，从而导致人造磁耗散和不连续性。我们重复动力学分析以提供纠正此问题的合适性。在Gorgon EXMHD代码中使用这些方法可以通过文献中的动力学模拟解决已知的差异。认识到$α_\ perp-α_\并行$和$β_\ Parallel-β_\ perp $的基本重要性，我们重新估算了一组系数，以发现它们现在每个系数都具有相同的潜在属性。这使磁和热传输方程的对称性以及系数本身的对称性。
In Braginskii extended magneto-hydrodynamics (ExMHD), applicable to collisional astrophysical and high energy density plasmas, the electric field and heat flow are described by the $α$, $β$ and $κ$ transport coefficients. We show that magnetic transport relies primarily on $β_\parallel-β_\perp$ and $α_\perp-α_\parallel$, rather than $α_\perp$ and $β_\perp$ themselves. However, commonly used coefficient fit functions [Epperlein and Haines, Phys. Fluids 29, 1029 (1986)] cannot accurately calculate these quantities. This means that many ExMHD simulations have significantly over-estimated the cross-gradient Nernst advection, resulting in artificial magnetic dissipation and discontinuities. We repeat the kinetic analysis to provide fits that rectify this problem. Use of these in the Gorgon ExMHD code resolves the known discrepancies with kinetic simulations in the literature. Recognizing the fundamental importance of $α_\perp-α_\parallel$ and $β_\parallel-β_\perp$, we re-cast the set of coefficients to find that each of them now shares the same underlying properties. This makes explicit the symmetry of the magnetic and thermal transport equations, as well as the symmetry of the coefficients themselves.
