Numerical study of nonlinear Alfven waves and solitons

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.865188· OSTI ID:6245887

Spangler, S R; Sheerin, J P; Payne, G L

Finite-amplitude Alfven waves can be modeled by a nonlinear wave equation termed the derivative nonlinear Schroedinger equation. A computer program has been developed that solves the derivative nonlinear Schroedinger equation via the ''split-step'' Fourier method. This program has been used to investigate a number of topics in the area of nonlinear Alfven waves. When analytic envelope solitons are used as initial conditions, the wave packets propagate without distortion and with the expected speed--amplitude relation. When an arbitrary, amplitude-modulated wave is used as an initial condition, the results depend strongly on the ..beta.. of the plasma and the polarization of the wave. For a left circularly polarized wave in a ..beta..<1 plasma, or a right circularly polarized wave with ..beta..>1, a collapse instability has been observed in which the wave amplitude increases and modulation scale decreases. For other combinations of polarization and value of ..beta.., the wave packet tends to broaden, eliminating the initial modulation.

• Research Organization: Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242
• OSTI ID: 6245887
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 28:1; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
ALFVEN WAVES
AMPLITUDES
COMPUTER CODES
DIFFERENTIAL EQUATIONS
DISPERSION RELATIONS
EQUATIONS
HOMOGENEOUS PLASMA
HYDROMAGNETIC WAVES
MAGNETIC FIELDS
MATHEMATICAL MODELS
NONLINEAR PROBLEMS
NUMERICAL SOLUTION
ONE-DIMENSIONAL CALCULATIONS
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA
POLARIZATION
QUASI PARTICLES
SCHROEDINGER EQUATION
SOLITONS
WAVE EQUATIONS