Le A, Egedal J, Daughton W, Fox W, Katz N
Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2009 Feb 27;102(8):085001. doi: 10.1103/PhysRevLett.102.085001. Epub 2009 Feb 25.
Direct in situ observation of magnetic reconnection in the Earth's magnetotail as well as kinetic numerical studies have recently shown that the electron pressure in a collisionless reconnection region is strongly anisotropic. This anisotropy is mainly caused by the trapping of electrons in parallel electric fields. We present new equations of state for the parallel and perpendicular pressures for magnetized electrons. This model-derived here and tested against a kinetic simulation-allows a fluid description in a collisionless regime where parallel electric fields and the dynamics of both passing and trapped electrons are essential.
近期，对地球磁尾中磁重联的直接原位观测以及动力学数值研究表明，无碰撞重联区域中的电子压力具有很强的各向异性。这种各向异性主要是由电子在平行电场中的捕获造成的。我们给出了磁化电子平行压力和垂直压力的新状态方程。这里推导并通过动力学模拟检验的该模型，允许在无碰撞状态下进行流体描述，其中平行电场以及通过电子和捕获电子的动力学至关重要。
