Nonlinear Alfven wave propagation in nonhomogeneous collisionless media

Abstract

view Abstract Citations (4) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Nonlinear Alfven Wave Propagation in Nonhomogeneous Collisionless Media Khabibrakhmanov, Ildar K. ; Summers, Danny Abstract A collisionless model of nonlinear Alfven wave propagation in a nonhomogenous medium is formulated in terms of two amplitude equations for the slow plasma parameters, the only fast parameter being the transverse component of the unit vector along the local magnetic field. The mdoel includes plasma pressure anisotropy and takes into account the relative motion of the plasma components along the magnetic field, effects which have hitherto not been considered in a self-consistent manner. Exact one-dimensional solutions are found under the restriction that the magnetic field, bulk plasma velocity vectors, and propagation direction all remain in the same plane. It is shown that these solutions reduce exactly to the standard Wentzel-Kramer-Brillouin (WKB) approximate solution, i.e., it is shown that the WKB solutions are, in fact, exact under the above stated restriction. The restriction is not related to the limitations of the WKB approximation, but merely specifies the mode of the propagating wave. This exact solution can be used as a zero-order approximation for the investigation of the stability of finite-amplitude Alfven waves. Thermal corrections to the wave amplitude solution are obtained as well as to the bulk plasma momentum equation. The wave amplitude solution shows that direct exchange of the Alfven wave energy with the kinetic energy of the particles is possible. Publication: The Astrophysical Journal Pub Date: May 1995 DOI: 10.1086/175652 Bibcode: 1995ApJ...444..796K Keywords: Collisionless Plasmas; Inhomogeneity; Magnetohydrodynamic Waves; Mathematical Models; Nonlinearity; Plasma Turbulence; Wave Propagation; Anisotropy; Kinetic Energy; Momentum Transfer; Pressure Effects; Stellar Winds; Wentzel-Kramer-Brillouin Method; Astronomy; PLASMAS; TURBULENCE; WAVES full text sources ADS |