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Title: Velocity space evolution of a minority energetic electron population undergoing the anomalous Doppler instability

The kinetic evolution in velocity space of a minority suprathermal electron population that is undergoing the anomalous Doppler instability (ADI) is investigated using the results from fully nonlinear numerical simulations that self-consistently evolve particles and fields in a plasma. Electron trajectories in phase space during different stages of the ADI are captured, and are analysed in relation to the characteristics of the excited electric fields and of the overall distribution of particles. For some electrons, trapping and mirroring effects are observed during the saturation phase. A relationship between the second order moments of the perpendicular electron distribution function and time is established, and is used to investigate the range of applicability of analytical approximations drawn from classical theory, that involve a quasilinear wave-driven diffusion operator.
Authors:
;  [1] ;  [1] ;  [2]
  1. Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry (United Kingdom)
  2. (United Kingdom)
Publication Date:
OSTI Identifier:
22489834
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 11; Other Information: (c) 2015 EURATOM; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; DIFFUSION; DISTRIBUTION FUNCTIONS; DOPPLER EFFECT; ELECTRIC FIELDS; INSTABILITY; NONLINEAR PROBLEMS; PHASE SPACE; PLASMA; TAIL ELECTRONS; TRAPPING; VELOCITY