Nonlinear Diffusive Shock Acceleration with Magnetic Field Amplification

Nonlinear Diffusive Shock Acceleration with Magnetic Field Amplification

We introduce a Monte Carlo model of nonlinear diffusive shock acceleration allowing for the generation of large-amplitude magnetic turbulence, i.e., ∆B ≫ B0, where B0 is the ambient magnetic field. The model is the first to include strong wave generation, efficient particle acceleration to relativistic energies in nonrelativistic shocks, and thermal particle injection in an internally self-cons...

Modeling Magnetic Field Amplification in Nonlinear Diffusive Shock Acceleration

Turbulence Dissipation and Particle Injection in Nonlinear Diffusive Shock Acceleration with Magnetic Field Amplification

The highly amplified magnetic fields suggested by observations of some supernova remnant shells are most likely an intrinsic part of efficient particle acceleration by shocks. This strong turbulence, which may result from cosmicray-driven instabilities, both resonant and nonresonant, in the shock precursor, is certain to play a critical role in selfconsistent, nonlinear models of strong, cosmic...

Turbulent amplification of magnetic field and diffusive shock acceleration of cosmic rays

The diffusive shock acceleration of cosmic rays by supernova remnants depends upon the generation of magnetic fluctuations by cosmic rays upstream of the shock. Strongly driven, non-resonant, nearly purely growing modes grow more rapidly than the resonant Alfvén waves usually considered. Non-linear simulation shows that the magnetic field can be amplified from its seed value by orders of magnit...

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...