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

Journal Article · Wed Aug 15 04:00:00 EDT 2012 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4742315· OSTI ID:22085995

Lopez, Rodrigo A; Munoz, Victor ^[1]; Asenjo, Felipe A ^[2]; Alejandro Valdivia, J ^[1]

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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)

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.

• OSTI ID: 22085995
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 8 Vol. 19; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

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