Aspects of stochastic transport in laboratory and astrophysical plasmas

Abstract

Basic principles of nonlinear transport theory in fluctuating electric and magnetic fields are reviewed. After a short overview of systematic transport truncations and statistical turbulence theories, the stochastic transport ansatz is introduced. The main analysis dwells on recent developments such as non-diffusive motion along tangles, Lagrangian closures, trapping and percolation limit, relativistic particle drifts, generation of radial electric fields, non-Gaussian magnetic field statistics, pitch angle scattering and control of stochasticity. Conclusions for heat flux patterns, plasma rotation, transport directions, ELM mitigation, runaway escape rates and cosmic ray transport are presented.