Distribution Functions of Energetic Particles Experiencing Compound Subdiffusion
Abstract
There are indications that the perpendicular transport of energetic particles is sometimes subdiffusive for intermediate timescales. This corresponds to a scenario where particles follow diffusive magnetic field lines while they also move diffusively in the parallel direction. This type of transport should occur at times after the ballistic regime but before the particles experience the transverse complexity of the turbulence. In this article we present a detailed analytical investigation of distribution functions of particles experiencing compound subdiffusion. Simple approximations of particle distributions are derived which can easily be used in applications. We also compare our findings with test-particle simulations performed for slab turbulence corresponding to the case of vanishing transverse turbulence structure.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2020
- DOI:
- 10.3847/1538-4357/ab6c69
- Bibcode:
- 2020ApJ...890..147S
- Keywords:
-
- Solar energetic particles;
- Galactic cosmic rays;
- Interplanetary turbulence;
- 1491;
- 567;
- 830