The Acceleration of Solar Energetic Particles by Coronal Mass Ejection Driven Shocks

Fast coronal mass ejections (CMEs) in the solar corona drive interplanetary shocks that accelerate solar energetic particles (SEPs) to produce high levels of radiation near Earth that can be hazardous to astronauts and even passengers in high altitude spacecraft, damage satellites, and cause polar lights (aurora). However, the details of the shock acceleration process is currently not well understood. To model this process requires understanding of how energetic charged particles propagate in the largely collisionless solar wind plasma emanating from Sun. These basic propagation mechanisms will be reviewed and it will be showed that they can be combined into a single kinetic transport equation, the so called focused transport equation. This equation has supplanted the standard cosmic-ray transport equation in recent years as the best way to
model SEP acceleration at CME shocks. It will be discussed how this equation contains the basic physics of collisionless shock acceleration. Numerical solutions of this equation will be shown to contrast the basic
features of the acceleration and transport of SEPs for strong and weak CME shocks which differ substantially from the standard steady-state shock acceleration picture.

Jakobus A. le Roux

UAHuntsville