Stochastic Fermi acceleration in the Earth´s magnetotail current sheet: Numerical studies

We show results from 2D and 3D test particle simulations investigating the acceleration of protons interacting with stationary and time-dependent electromagnetic fields. In the 2D simulations we mimic a Fermi-like interaction between particles and randomly positioned oscillating clouds. A constant dawn-dusk electric field and a constant out of plane magnetic field are also present. The 3D model studies that process in a more realistic configuration: a modified Harris profile has also been added. Parametric studies have been performed and the results discussed also in comparison with spacecraft observations in both the distant and the near-Earth magnetotail.