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Title: Parametric decays in relativistic magnetized electron-positron plasmas with relativistic temperatures

The nonlinear evolution of a circularly polarized electromagnetic wave in an electron-positron plasma propagating along a constant background magnetic field is considered, by studying its parametric decays. Relativistic effects, of the particle motion in the wave field and of the plasma temperature, are included to obtain the dispersion relation of the decays. The exact dispersion relation of the pump wave has been previously calculated within the context of a relativistic fluid theory and presents two branches: an electromagnetic and an Alfven one. We investigate the parametric decays for the pump wave in these two branches, including the anomalous dispersion zone of the Alfven branch where the group velocity is negative. We solve the nonlinear dispersion relation for different pump wave amplitudes and plasma temperatures, finding various resonant and nonresonant wave couplings. We are able to identify these couplings and study their behavior as we modify the plasma parameters. Some of these couplings are suppressed for larger amplitudes or temperatures. We also find two kinds of modulational instabilities, one involving two sideband daughter waves and another involving a forward-propagating electroacoustic mode and a sideband daughter wave.
Authors:
;  [1] ;  [2] ;  [1] ;  [3]
  1. Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile)
  2. Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)
  3. (Chile)
Publication Date:
OSTI Identifier:
22085995
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 19; Journal Issue: 8; Other Information: (c) 2012 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; ALFVEN WAVES; DISPERSION RELATIONS; ELECTROMAGNETIC RADIATION; ELECTRON TEMPERATURE; ELECTRON-POSITRON INTERACTIONS; FLUID MECHANICS; INSTABILITY; ION TEMPERATURE; MAGNETIC FIELDS; NONLINEAR PROBLEMS; RELATIVISTIC PLASMA; RELATIVISTIC RANGE