Amplitude limits and nonlinear damping of shear-Alfvén waves in high-beta low-collisionality plasmas
Amplitude limits and nonlinear damping of shear-Alfvén waves in high-beta low-collisionality plasmas
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高β低碰撞等离子体中剪切阿尔文波的振幅限制和非线性阻尼
DOI：
10.1088/1367-2630/aa6bb1
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发表时间：
2017
影响因子：
3.3
通讯作者：
E. Quataert
中科院分区：
文献类型：
--
作者：
J. Squire;A. Schekochihin;E. Quataert
这项工作，扩展了乡绅等人（Astrophys. J. Lett. 2016 830 L25），探讨了自生压力各向异性对低碰撞等离子体中线性偏振剪切阿尔文波动的影响。这种各向异性导致高β等离子体中磁扰动幅度的严格限制，超过该限制，波动可以通过平行消防水龙带不稳定性而使自身不稳定。这导致波的频率接近零，“中断”波并停止其振荡。详细探讨了这些影响中的碰撞和弱碰撞的“Braginskii”制度，驻波和行波。重点是简化模型在一个维度上，尺度远大于离子回旋半径。这种效应对于在许多天体物理等离子体中普遍存在的高β条件下的磁化湍流物理学具有有趣的意义。
This work, which extends Squire et al (Astrophys. J. Lett. 2016 830 L25), explores the effect of self-generated pressure anisotropy on linearly polarized shear-Alfvén fluctuations in low-collisionality plasmas. Such anisotropies lead to stringent limits on the amplitude of magnetic perturbations in high-β plasmas, above which a fluctuation can destabilize itself through the parallel firehose instability. This causes the wave frequency to approach zero, ‘interrupting’ the wave and stopping its oscillation. These effects are explored in detail in the collisionless and weakly collisional ‘Braginskii’ regime, for both standing and traveling waves. The focus is on simplified models in one dimension, on scales much larger than the ion gyroradius. The effect has interesting implications for the physics of magnetized turbulence in the high-β conditions that are prevalent in many astrophysical plasmas.
天体物理等离子体中的宇宙射线传输
影响因子：
2.2
作者：
Schlickeiser
通讯作者：
Schlickeiser