Simulations of coronal shock acceleration in self-generated turbulence

We have recently presented a numerical model to simulate the acceleration and transport of energetic particles at coronal shock waves, which includes the back-reaction of the energetic particles on the Alfven waves responsible for their scattering in the ambient medium [Vainio, R., Laitinen, T., 2007. Monte Carlo simulations of coronal diffusive shock acceleration in self-generated turbulence. Astrophysical Journal 658, 622-630]. The model results imply that the acceleration of energetic protons to energies exceeding 100 MeV can occur in some minutes in parallel coronal shocks driven by fast CMEs. In this paper we give a detailed description of the numerical model and its foreseen extensions. We extend the parameter study presented in the first paper to cover (shorter and) longer time scales, and present the intensities observed in the interplanetary medium during the initial phases of an SEP event. We also study the scattering mean free path resulting from the self-consistent computations. Finally, the potential of the model to explain ion acceleration up to relativistic energies is discussed. (C) 2007 Elsevier Ltd. All rights reserved.