Temporary topological trapping and escape of charged particles in a flux tube as a cause of delay in time asymptotic transport



[1] The scenario of temporary trapping of magnetic field lines and their subsequent suppressed diffusive escape from topological magnetic structures embedded in turbulence has been offered as a way to understand the persistence of “dropouts”, or sharp gradients in observed heliospheric energetic particle intensities. Here a set of numerical experiments is carried out to show the basic physics of this process: charged test particles can be temporarily trapped in flux tubes and then escape due to random turbulent perturbations in the magnetic field. The overall effect is a delay in the onset of time-asymptotic transport. We thus confirm that previous arguments based on field line transport are also applicable to test particle transport.