3.2.3 Properties and distribution of near-Sun shocks, their fluctuations and particle acceleration

The answers to fundamental questions about the sources and acceleration mechanisms of the so-called large gradual SEPs, whether flares or shocks, depend on many factors including magnetic connection to active regions that produce flares (e.g., Cane et al., 2006) and on properties of the CME-driven shocks in the solar corona and the inner heliosphere (Tylka et al. 2005; Desai et al., 2006a). We need to understand the coronal conditions under which the shocks form and determine the interplanetary conditions where they evolve. We must then use this information to characterize shock structure, determine whether they are locally quasi-perpendicular or quasi-parallel, and then study kinetic properties of shock-related waves and turbulence that control ion scattering mean free paths near the shock. With geometric and microphysical shock properties determined, we can infer the rates of particle acceleration and the injection energies as a function of distance and along different parts of the shock. We need to derive particle acceleration rates near shocks, and by measuring shocks at many different radii, we will determine the acceleration rates as a function of distance from the Sun.