Acceleration and transport of heavy ions at coronal mass ejection-driven shocks

CME-driven shocks are now widely accepted as the site for large solar energetic particle (SEP) events. Particles are often accelerated to MeV energies (and perhaps up to GeV energies) at shock waves driven by coronal mass ejections (CMEs). These shock-accelerated particles, can propagate to 1AU and interact with the earth's geomagnetic field, often preceding to space storms. Questions remain however about the basic particle acceleration mechanism by CME driven shock and where the exact accleration site is and what the accelerated particle composition is? Various observations have been caried out to answer these questions. For example, gamma ray lines of the de-excitation of heavy nuclei in the sun's atmosphere as well as hard X-ray and gamma ray continuum when the heavy ions percipitated to the surface of the sun are sometimes used to identify the ion composition and the location of the acceleration site. Direct observations of in-situ particles by various spacecraft such as WIND, ACE,etc. allow us to investigate the charge states of various heavy ions, constraining the temperature of the acceleration site; to examine the relative abundance of various heavy elements to infer how much flare material, if any, must be present as the seed particle population, etc. To understand these observations, one needs a sophisticated model to follow the acceleration and transport of heavy ions. Here, we report our current progress on the acceleration and transport of heavy ions at CME-driven shocks. We show time intensity profiles and time-interval spectra for two groups of heavy ions: CNO and Fe respectively, and discurss the role of the wave field generated by accelerated protons at the shock.