An Integrated CME-SEP Numerical Investigation of the 1998 May 1-2 CME Events Part II: SEP-Turbulence Model for the Shock Wave

Collisionless shock waves in the interplanetary medium are considered as possible sites for the acceleration of Solar Energetic Particles (SEPs). The SEPs produce a serious radiation hazards onboard manned space flights, so that the interrelated study of the interplanetary shock waves and the accelerated particles (mostly, protons) is of a practical importance. On the other hand, the physics of collisionless shock waves, which accelerate ions, which, in turn, generate MHD turbulence in the vicinity of the shock wave front is a highly topical problem of the plasma theory. This is because the excited turbulence is responsible both for the ion acceleration and for the structure of the collisionless shock wave itself. In the present work, we use a coupled model that describes the low-frequency plasma turbulence and the SEP acceleration and transport. For simplicity, we use the quasi-linear theory to evaluate the growth rate of the turbulent waves, and the particle motion is described in the diffusive approximation. The effects taken into account are: the realistic evolution of the shock wave, the advection of the magnetic field line in realistic solar wind model, the first-order Fermi acceleration for supra-thermal ions, and a self-consistent description of the self-excited Alfven turbulence and the particle scattering at this turbulence. The main goal is to analyze the acceleration of different sorts of ions and the resonant effects in their interaction with turbulence. The observed anomalies in the ion abundances in SEPs may be the result of these resonant effects. This investigation is funded by a NASA-LWS grant.