Magnetic field line random walk in two-dimensional dynamical turbulence

Abstract

The field line random walk (FLRW) of magnetic turbulence is one of the important topics in plasma physics and astrophysics. In this article by using the field line tracing method mean square displacements (MSD) of FLRW is calculated in all possible length scales for pure two-dimensional turbulence with damping dynamical model. We demonstrate that in order to describe FLRW with damping dynamical model a new dimensionless quantity $R$ is needed to be introduced. In different length scales dimensionless MSD shows different relationship with the dimensionless quantity $R$. Although temporal effect impacts MSD of FLRW and even changes regimes of FLRW, it dose not affect the relationship between the dimensionless MSD and dimensionless quantity $R$ in all possible length scales

Parallel and Perpendicular Diffusion Coefficients of Energetic Charged Particles with Adiabatic Focusing

“…Energetic charged particle propagation in magnetic turbulent field is one of the fundamental problems in astrophysics (e.g., cosmic ray physics, astrophysical plasmas, and space weather research) and Tokamak fusion devices (see, e.g., Jokipii 1966;Schlickeiser 2002;Matthaeus et al 2003;Shalchi & Schlickeiser 2005;Shalchi et al 2006;Qin 2007;Hauff & Jenko 2008;Shalchi 2009aShalchi , 2010Qin & Zhang 2014). The magnetic turbulence can cause the field line wandering, or the field line random walk (FLRW) (Jokipii 1966;Matthaeus et al 1995;Shalchi & Kourakis 2007;Shalchi & Qin 2010;Wang et al 2017a), which directly affects the diffusion of charged particles. In the investigation of energetic particle transport through magnetized plasma, according to observations one usually assumes the magnetic field configuration as the superposition of a background magnetic field B 0 and a turbulent component δ B.…”