TY - JOUR
TI - Two-dimensional PIC simulations of ion beam instabilities in Supernova-driven plasma flows
AU - Dieckmann, M.E.
AU - Meli, A.
AU - Shukla, P.K.
AU - Drury, L.O.C.
AU - Mastichiadis, A.
JO - Plasma Physics and Controlled Fusion
PY - 2008
VL - 50
TODO - 6
SP - null
PB - 
SN - 0741-3335
TODO - 10.1088/0741-3335/50/6/065020
TODO - Ion bombardment;  Plasma diagnostics;  Two dimensional, Flow speeds;  PIC simulations;  Supernova (SN);  supernova remnants;  Two-dimensional (2D), Plasma stability
TODO - Supernova remnant blast shells can reach the flow speed vs = 0.1c and shocks form at its front. Instabilities driven by shock-reflected ion beams heat the plasma in the foreshock, which may inject particles into diffusive acceleration. The ion beams can have the speed vb ≈ vs. For vb ≪ vs the Buneman or upper-hybrid instabilities dominate, while for vb ≫ vs the filamentation and mixed modes grow faster. Here the relevant waves for v b ≈ vs are examined and how they interact nonlinearly with the particles. The collision of two plasma clouds at the speed v s is modelled with particle-in-cell simulations, which convect with them magnetic fields oriented perpendicular to their flow velocity vector. One simulation models equally dense clouds and the other one uses a density ratio of 2. Both simulations show upper-hybrid waves that are planar over large spatial intervals and that accelerate electrons to ∼10 keV. The symmetric collision yields only short oscillatory wave pulses, while the asymmetric collision also produces large-scale electric fields, probably through a magnetic pressure gradient. The large-scale fields destroy the electron phase space holes and they accelerate the ions, which facilitates the formation of a precursor shock. © 2008 IOP Publishing Ltd.
ER -