The evolution of strongly modulated, low-frequency, moderate-amplitude wave packets in a dispersive plasma

Journal Article · Fri Jan 01 04:00:00 EST 1993 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860866· OSTI ID:6941172

Vasquez, B J; Cargill, P J ^[1]

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1. Department of Astronomy, University of Maryland, College Park, Maryland 20742 (United States)

The evolution of strongly modulated wave packets in a dispersive plasma that propagate parallel to the magnetic field is studied. Modulation effects are shown to reduce significantly ([approx]30%) the rate of spreading from that due to dispersion alone. For fluidlike behavior, nonlinearity has its greatest impact on evolution when the linear sound speed and initial wave packet speeds are well matched, resulting in a strong coupling between the wave magnetic and sonic components. Ion kinetic processes reduce the impact of nonlinearity and cause the rate of spreading to approach that expected from dispersion alone as the ratio of ion and electron temperatures, [ital T][sub [ital i]]/[ital T][sub [ital e]][r arrow]4. For [beta][approx gt]1 and [ital T][sub [ital i]]/[ital T][sub [ital e]][similar to]1, the coupled waveforms correspond qualitatively to kinetic treatments of the derivative nonlinear Schroedinger (DNLS) equation.

• OSTI ID: 6941172
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 5:1; ISSN 0899-8221; ISSN PFBPEI
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
DIFFERENTIAL EQUATIONS
ELECTROMAGNETIC FIELDS
ELECTRON TEMPERATURE
EQUATIONS
ION TEMPERATURE
MODULATION
PARTIAL DIFFERENTIAL EQUATIONS
SCHROEDINGER EQUATION
WAVE EQUATIONS
WAVE PACKETS