HR: 1340h
AN: SM33C-0459    [Abstracts]
TI: Particle acceleration and energy distribution in multi-streaming plasmas
AU: * Marocchino, A
EM: albertom@lanl.gov
AF: Politecnico di Torino, Corso Duca degli Abruzzi, torino, 10129 Italy
AU: Markidis, S
EM: s.markidis@gmail.com
AF: UNM, CS Dept, albuquerque, 87500 United States
AU: Lapenta, G
EM: lapenta@lanl.gov
AF: LANL, C305, los alamos, 87544 United States
AB: The origin of high-energy particles and their energy distribution is one of the primary challenges facing space physics and astrophysics. We consider two types of events where particle acceleration is observed: shocks and reconnection. We simulate both type of events with a fully kinetic and fully relativistic approach aimed at measuring directly particle acceleration. In each process we observe two types of effects: increase of directed energy (creation of beams) and increase of plasma temperature. The two effects are intertwined as beams interact with the plasma through a variety of beaming instabilities and turn their directed energy into thermal energy. However, often non Maxwellian distributions are observed. Our approach follows two paths. First, we investigate by direct simulation the energy distribution produced by reconnection, shocks and streaming instabilities. Second, we consider a general mathematical formulation that allows us to predict the distribution function of the high-energy particles. In particular, we derive a new approach to demonstrate the physical origin of power laws.
DE: 7835 Magnetic reconnection (2723, 7526)
DE: 7845 Particle acceleration
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005