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Title: Excitation and evolution of finite-amplitude plasma wave

The evolution of a small spatially periodic perturbation in the electron velocity distribution function in collisionless plasma is reconsidered by numerically solving the Vlasov and Poisson equations. The short as well as long time behaviors of the excited oscillations and damping/modulation are followed. In the small but finite-amplitude excited plasma wave, resonant electrons become trapped in the wave potential wells and their motion affects the low-velocity electrons participating in the plasma oscillations, leading to modulation of the latter at an effective trapping frequency. It is found that the phase space of the resonant and low-velocity electrons becomes chaotic, but then self-organization takes place but remains fine-scale chaotic. It is also found that as long as particles are trapped, there is only modulation and no monotonic damping of the excited plasma wave. The modulation period/amplitude increases/decreases as the magnitude of the initial disturbance is reduced. For the initial and boundary conditions used here, linear Landau damping corresponds to the asymptotic limit of the modulation period becoming infinite, or no trapping of the resonant electrons.
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)
  2. School of Electronic Science and Applied Physics, Hefei University of Technology, Hefei, Anhui 230009 (China)
  3. Institute for Fusion Theory and Simulation and Department of Physics, Zhejiang University, Hangzhou 310027 (China)
  4. (Germany)
  5. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)
Publication Date:
OSTI Identifier:
22489907
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BOUNDARY CONDITIONS; COLLISIONLESS PLASMA; DISTRIBUTION FUNCTIONS; DISTURBANCES; ELECTRONS; EXCITATION; LANDAU DAMPING; MODULATION; OSCILLATIONS; PLASMA WAVES; POISSON EQUATION; TRAPPING