Analytical description of field-line random walk in Goldreich-Sridhar turbulence

作者：Shalchi A^*; Kolly A

来源：Monthly Notices of the Royal Astronomical Society, 2013, 431(2): 1923-1928.

DOI：10.1093/mnras/stt306

• diffusion
• magnetic fields
• turbulence

We describe analytically the random walk of magnetic field lines for two correlation tensors based on the Goldreich-Sridhar model. We show that for this type of tensor, field-line wandering is normal diffusive in contrast to subdiffusive and superdiffusive transport obtained for other turbulence models. Furthermore, we demonstrate that there are two transport regimes. The first one corresponds to quasi-linear theory, whereas the second one is non-linear. We show that for one of the tensors the quasi-linear regime is obtained in the limit of strong turbulence, whereas the non-linear regime is found for weak turbulence. For the other tensor, we obtain a field-line diffusion coefficient which behaves more like diffusion parameters derived previously.

• 出版日期2013-5