Speaker
Description
Quasilinear theory has dominated the description of charged particle transport in magnetic turbulence since the 1960s.
While it leads to important insights, one should keep in mind that it characterizes the turbulent magnetic field solely
by the power spectrum, which has lead to a wide range of models describing the magnetic field by a simple self-similar
random field with a prescribed two-point correlation structure.
That this is not sufficient for a more realistic model can be concluded from magneto-hydrodynamic (MHD) simulations and
solar wind observations that exhibit multifractal behaviour and coherent structures such as current sheets.
Recently, there has been an increased interest in the transport of charged particles in non-Gaussian random magnetic fields
as well as MHD fields, however the exact processes are not yet fully understood.
We investigate how certain features of such fields modify the transport behaviour by comparing test particle simulations in
simple self-similar random fields, unstructured multifractal random fields, a variant of the minimal multi-scale Lagrangian
mapping procedure, and full 3D MHD fields.
The statistics and the structures of the employed fields are studied via their structure functions and occurrence of different magnetic features including field line curvature.
