HR: 1340h
AN: SH23A-0317    [Abstracts]
TI: Hybrid Simulations of Coronal Mass Ejection Shock Structures
AU: * Gargate, L
EM: luisgargate@cfp.ist.utl.pt
AF: GoLP/CFP Instituto Superior Tecnico, CFP Instituto Superior Tecnico Av. Rovisco Pais, Lisboa, 1049-001 Portugal
AU: * Gargate, L
EM: luisgargate@cfp.ist.utl.pt
AF: Rutherford Appleton Laboratory, Rutherford Appleton Laboratory Chilton, Didcot, OX11 0QX United Kingdom
AU: Bingham, R
EM: r.bingham@rl.ac.uk
AF: Rutherford Appleton Laboratory, Rutherford Appleton Laboratory Chilton, Didcot, OX11 0QX United Kingdom
AU: Fonseca, R
EM: ricardo.fonseca@ist.utl.pt
AF: GoLP/CFP Instituto Superior Tecnico, CFP Instituto Superior Tecnico Av. Rovisco Pais, Lisboa, 1049-001 Portugal
AU: Silva, L
EM: luis.silva@ist.utl.pt
AF: GoLP/CFP Instituto Superior Tecnico, CFP Instituto Superior Tecnico Av. Rovisco Pais, Lisboa, 1049-001 Portugal
AB: We use a 3D hybrid particle code, dHybrid, to simulate the corona environment and the acceleration mechanisms of Solar Energetic Particles. The CME structure propagates at speeds up to 1000 km/s interacting with the slower solar wind. This interaction and the presence of the embedded solar magnetic field cause the formation of a large scale quasi-parallel shock structure. The simulation results support a surfatron-like acceleration model as the mechanism responsible for the most energetic ions. Particles are not observed to cross the shock front several times, as it is required by Fermi acceleration mechanisms. Instead, our results show that particles crossing the shock front accelerate perpendicularly to the shock front while maintaining their parallel velocity. Whistler and magnetoacoustic waves develop and are responsible, along with the electric potential developed in the shock front, for the electric field structure observed allowing the surfing acceleration mechanism. In this surfatron mode, the shock is quasi-parallel to the magnetic field, as opposed to the regular surfatron acceleration where the shock is perpendicular to the magnetic field. The physical characteristics of the quasi-parallel surfatron are derived.
DE: 2114 Energetic particles (7514)
DE: 2139 Interplanetary shocks
DE: 2164 Solar wind plasma
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005