HR: 15:45h
AN: SH53A-08    [Abstracts]
TI: Energetic electron bursts from a reforming High Mach Number collisionless shock
AU: yuan, X
EM: xqyuan@physics.usyd.edu.au
AF: School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
AU: * Cairns, I H
EM: cairns@physics.usyd.edu.au
AF: School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
AU: Robinson, P A
EM: robinson@physics.usyd.edu.au
AF: School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
AB: Collisonless shocks redistribute energy, heating and accelerating electrons responsible for various plasma waves and emissions in the upstream and downstream shock region. In this paper we study numerically the electron dynamics in time-dependent shock fields generated by an one-dimensional multiscale hybrid code, and steady state model shocks by tracing the exact test particle electron trajectories. It is shown that the upstream energetic electron bursts are produced cyclically at the shock reformation period in the time-dependent reforming shocks. Observation of the upstream electron distribution functions shows time-varying loss cone structures and beam features. In contrast to the reforming shocks, a continous electron beam is formed by the reflected electrons in upstream of steady state model shocks. This calculation demonstrates that shock nonstationarity will lead to major changes in electron distributions and associated plasma waves upstream and downstream, probably requiring modification to the steady state shock model used for predicting foreshock radio emission.
DE: 7800 SPACE PLASMA PHYSICS
DE: 7807 Charged particle motion and acceleration
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Joint Assembly