Heavy ions transport in selected SEP events
Abstract
In Solar Energetic Particle (SEP) events, particles are accelerated to energies of > 100 MeV/nuc near the Sun and then propagate to 1 AU. Transport of these energetic particles in the solar wind is subject to pitch angle scattering by solar wind MHD turbulence. The observed time intensity profile, particle spectrum, and anisotropy at 1 AU depend on the injected particle profile, the turbulence spectral index, as well as the radial evolution of the turbulence strength. In this work we focus on the propagation effects due to solar wind MHD turbulence. We use a Monte-Carlo simulation to study the transport of energetic particles. Specifically, we follow single particle motion which includes a deterministic piece and a stochastic piece. The latter describes the pitch angle scattering in the framework of the Quasi Linear Theory. Using this code, we report our recent effort on modeling selected SEP events. We consider Helium, CNO and Iron ions and note explicitly the Q/A dependence. By comparing simultaneously our results with multiple energy channels and multiple heavy ions from the ACE/ULEIS and ACE/SIS observations, we obtain some best fit parameters for the injected particle spectra and interplanetary MHD turbulence. Results and implications from our modeling are discussed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMSH22A..03Z
- Keywords:
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- 7807 SPACE PLASMA PHYSICS / Charged particle motion and acceleration;
- 7859 SPACE PLASMA PHYSICS / Transport processes