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Title: Nonlinear evolution of Buneman instability and its implication for electron acceleration in high Mach number collisionless perpendicular shocks

Nonlinear evolution of the Buneman instability and its application to electron acceleration in collisionless shocks are discussed. Two-dimensional particle-in-cell simulations show that the saturation level of the instability is reduced from one-dimensional simulation results. It is demonstrated that the reduced saturation level is due to the resonant wave-particle interactions with large amplitude obliquely propagating waves. A new estimate for the saturation level is given by considering the interactions with oblique modes. The effects of the large amplitude oblique modes on electron shock surfing acceleration that is mainly controlled by the Buneman instability are also investigated. Two-dimensional particle-in-cell simulations of the shock transition region are performed by adopting a local model with the periodic boundary condition. The results indicate that the presence of oblique modes introduces a stochastic behavior to the trajectories of energetic electrons. The maximum energy is limited by the finite lifetime of the instability in the present periodic model. However, this will not be the case in the realistic shock transition region. The application to realistic shocks with Mach numbers typical of supernova remnants is also discussed.
Authors:
 [1] ;  [2]
  1. Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)
  2. Department of Earth and Planetary Science, University of Tokyo, Tokyo 113-0033 (Japan)
Publication Date:
OSTI Identifier:
21272725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 16; Journal Issue: 10; Other Information: DOI: 10.1063/1.3240336; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACCELERATION; MACH NUMBER; NONLINEAR PROBLEMS; PARTICLE INTERACTIONS; PLASMA INSTABILITY; PLASMA SIMULATION; SHOCK WAVES; STOCHASTIC PROCESSES; SUPERNOVA REMNANTS; TAIL ELECTRONS; TWO-DIMENSIONAL CALCULATIONS