电子磁流体波包中的磁螺旋度守恒和逆能量级联
Magnetic Helicity Conservation and Inverse Energy Cascade in Electron Magnetohydrodynamic Wave Packets
摘要：
电子磁流体力学（EMHD）提供了一个小尺度磁化等离子体的流体般的描述。EMHD波（也称为哨声波）沿着磁场线传播。传播方向可以平行于或反平行于磁场线。我们数值研究了三维电磁流体波包沿一个方向的传播。我们得到两个主要结果：1.与磁流体动力学（MHD）对应物不同，EMHD波包是色散的。正因为如此，在一个方向上行进的EMHD波包通过自相互作用产生相反的行波包，并将能量级联到更小的尺度。2.沿一个方向传播的EMHD波包明显地表现出逆能量级联。我们发现后者是由于磁螺旋度守恒。比较了三维EMHD湍流和二维流体动力学湍流中的能量逆级联。
英文摘要：
Electron magnetohydrodynamics (EMHD) provides a fluid-like description of small-scale magnetized plasmas. An EMHD wave (also known as whistler wave) propagates along magnetic field lines. The direction of propagation can be either parallel or anti-parallel to the magnetic field lines. We numerically study propagation of 3-dimensional (3D) EMHD wave packets moving in one direction. We obtain two major results: 1. Unlike its magnetohydrodynamic (MHD) counterpart, an EMHD wave packet is dispersive. Because of this, EMHD wave packets traveling in one direction create opposite traveling wave packets via self-interaction and cascade energy to smaller scales. 2. EMHD wave packets traveling in one direction clearly exhibit inverse energy cascade. We find that the latter is due to conservation of magnetic helicity. We compare inverse energy cascade in 3D EMHD turbulence and 2-dimensional (2D) hydrodynamic turbulence.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
