Particle acceleration by combined diffusive shock acceleration and downstream multiple magnetic island acceleration

Diffusive Shock Acceleration and Reconnection Acceleration Processes

Shock waves, as shown by simulations and observations, can generate high levels of downstream vortical turbulence, including magnetic islands. We consider a combination of diffusive shock acceleration (DSA) and downstream magnetic-island-reconnection-related processes as an energization mechanism for charged particles. Observations of electron and ion distributions downstream of interplanetary ...

Thermal Particle Injection in Nonlinear Diffusive Shock Acceleration

Donald C. Ellison, Pasquale Blasi, Stefano Gabici (a) Physics Dept., North Carolina State Univ., Raleigh, NC 27695, U.S.A. (b) High Energy Astrophysics Group, INAF, Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125, Firenze, Italy (c) Humboldt Fellow, Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany Presenter: Don Ellison (don [email protected]), usa...

Test-Particle Diffusive Shock Acceleration in Relativistic Shocks

We present results from a fully relativistic Monte Carlo simulation of diffusive shock acceleration (DSA) in unmodified (i.e., test-particle) shocks. The computer code uses a single algorithmic sequence to smoothly span the range from nonrelativistic speeds to fully relativistic shocks of arbitrary obliquity, providing a powerful consistency check. We show the dependence of the particle spectru...

Dynamics of Mesoscale Magnetic Field in Diffusive Shock Acceleration

We present a theory for the generation of mesoscale (k rgT1, where rg is the cosmic-ray gyroradius) magnetic fields during diffusive shock acceleration. The decay or modulational instability of resonantly excited Alfvén waves scattering off ambient density perturbations in the shock environment naturally generates larger scale fields. For a broad spectrum of perturbations, the physical mechanis...

Modeling Magnetic Field Amplification in Nonlinear Diffusive Shock Acceleration