scholarly journals Chaos and Intermittency in the DNLS Equation Describing the Parallel Alfvén Wave Propagation

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Gustavo Krause ◽  
Sergio Elaskar ◽  
Andrea Costa
Keyword(s):  
Wave Propagation ◽  
Time Integration ◽  
Alfven Wave ◽  
Circularly Polarized ◽  
Polarized Waves ◽  
Different Types ◽  
Spatial Derivatives ◽  
Modulational Stability ◽  
Dnls Equation ◽  
Hall Mhd

When the Hall effect is included in the magnetohydrodynamics equations (Hall-MHD model) the wave propagation modes become coupled, but for propagation parallel to the ambient magnetic field the Alfvén mode decouples from the magnetosonic ones, resulting in circularly polarized waves that are described by the derivative nonlinear Schrödinger (DNLS) equation. In this paper, the DNLS equation is numerically solved using spectral methods for the spatial derivatives and a fourth order Runge-Kutta scheme for time integration. Firstly, the nondiffusive DNLS equation is considered to test the validity of the method by verifying the analytical condition of modulational stability. Later, diffusive and excitatory effects are incorporated to compare the numerical results with those obtained by a three-wave truncation model. The results show that different types of attractors can exist depending on the diffusion level: for relatively large damping, there are fixed points for which the truncation model is a good approximation; for low damping, chaotic solutions appear and the three-wave truncation model fails due to the emergence of new nonnegligible modes.

Extension of Doughterty's model Fokker–Planck equation for a plasma

1974 ◽  
Vol 11 (1) ◽  
pp. 11-35
Author(s):  
Robert J. Papa
Keyword(s):  
Wave Propagation ◽  
Distribution Function ◽  
Spatial Dispersion ◽  
Collision Frequency ◽  
Electron Velocity ◽  
Signal Frequency ◽  
Coulomb Collision ◽  
Circularly Polarized ◽  
Polarized Waves ◽  
Energy Dependent

A generalization of the Appleton–Hartree equation is made to include the effects of energy-dependent electron-neutron collisions, Coulomb encounters and spatial dispersion. The frequency of electromagnetic waves propagating in a magneto-plasma is sufficiently high that the ion motion may be neglected compared with the electron motion. The present analysis extends Dougherty (1963, 1964) to include the simultaneous effect on wave propagation of Coulomb forces, spatial dispersion and energy-dependent electron-neutral collisions, where one or more of these effects can have a significant influence on circularly polarized waves propagating at frequencies near electron cyclotron resonance. The electrical conductivity tensor is expressible in terms of appropriate velocity moments of the electron distribution function. The electron velocity distribution function is determined by expanding the inverse of the differential operator of the linearized kinetic equation in a small parameter ε2', where in one case ε2 is the ratio of Coulomb collision frequency to signal frequency, and in the second case ε2 is the ratio of electron-neutral collision frequency to signal frequency. For wave propagation along the magnetic field, the dispersion relations for right-hand and left-hand circularly polarized waves, and also the dispersion relation for longitudinal waves, are solved numerically, and graphs are presented to show the effects of collisionless damping, velocity dependent electron-neutral collisions and Coulomb collisions.

Resonances in submillimetric Alfvén wave propagation in Bismuth

1967 ◽  
Vol 5 (9) ◽  
pp. 719-722 ◽  
Author(s):  
D.L. Carter ◽  
J.C. Picard
Keyword(s):  
Wave Propagation ◽  
Alfven Wave

Parametric excitation in an inhomogeneous plasma

1971 ◽  
Vol 5 (1) ◽  
pp. 107-113 ◽  
Author(s):  
C. S. Chen
Keyword(s):  
Electric Field ◽  
Parametric Excitation ◽  
Growth Rates ◽  
Inhomogeneous Plasma ◽  
Electron Plasma ◽  
Transverse Waves ◽  
Circularly Polarized ◽  
Polarized Waves ◽  
Oscillating Electric Field ◽  
Unmagnetized Plasma

An infinite, inhomogeneous electron plasma driven by a spatially uniform oscillating electric field is investigated. The multi-time perturbation method is used to analyze possible parametric excitations of transverse waves and to evaluate their growth rates. It is shown that there exist subharmonic excitations of: (1) a pair of transverse waves in an unmagnetized plasma and (2) a pair of one right and one left circularly polarized wave in a magnetoplasma. Additionally, parametric excitation of two right or two left circularly polarized waves with different frequencies can exist in a magnetoplasma. The subharmonic excitations are impossible whenever the density gradient and the applied electric field are perpendicular. However, parametric excitation is possible with all configurations.

Kinetic Alfven wave propagation in cylindrical Tokamak

1982 ◽  
Vol 24 (9) ◽  
pp. 1027-1041 ◽  
Author(s):  
S -I Itoh ◽  
K Itoh ◽  
K Nishikawa
Keyword(s):  
Wave Propagation ◽  
Alfven Wave ◽  
Kinetic Alfvén Wave ◽  
Kinetic Alfven Wave

Generation of Alfvén wave energy during magnetic reconnection in Hall MHD

2017 ◽  
Vol 19 (10) ◽  
pp. 105001 ◽  
Author(s):  
Lingjie LI ◽  
Zhiwei MA ◽  
Licheng WANG
Keyword(s):  
Magnetic Reconnection ◽  
Wave Energy ◽  
Alfven Wave ◽  
Hall Mhd

Alfvén wave propagation in a partially ionized plasma

2004 ◽  
Vol 11 (4) ◽  
pp. 1358-1365 ◽  
Author(s):  
Christopher Watts ◽  
Jeremy Hanna
Keyword(s):  
Wave Propagation ◽  
Alfven Wave ◽  
Partially Ionized

The Microwave Permeability of a Ferrite-Filled Parallel-Plate Transmission Structure

1973 ◽  
Vol 51 (23) ◽  
pp. 2495-2497
Author(s):  
C. K. Campbell
Keyword(s):  
Parallel Plate ◽  
Effective Permeability ◽  
Phase Shifter ◽  
Permeability Tensor ◽  
Ferrite Phase ◽  
Circularly Polarized ◽  
Polarized Waves ◽  
Transmission Structure ◽  
Microwave Permeability

With the aid of a phasor diagram it is shown that the scalar effective permeability μe = (μ2 − K2)/μ of a parallel-plate longitudinally magnetized microwave ferrite phase shifter may be simply obtained in terms of four circularly polarized waves relating to the permeability tensor eigenvalues μ + K and μ − K.

scholarly journals A method for separating O-wave and X-wave and its application in digital ionosonde

2014 ◽  
Vol 56 (5) ◽  
Author(s):  
Wang Shun ◽  
Chen Ziwei ◽  
Zhang Feng ◽  
Gong Zhaoqian ◽  
Li Jutao ◽  
...  
Keyword(s):  
Image Recognition ◽  
Initial Phase ◽  
Phase Shifters ◽  
New Method ◽  
Digital Method ◽  
Electrical Method ◽  
Circularly Polarized ◽  
Automatic Scaling ◽  
Polarized Waves ◽  
Phase 0

<p><strong><em></em></strong>Separation for O wave and X wave is a very important job in interpretation of ionograms, which is premise for automatic scaling. In this paper, a new digital method for separating O wave and X wave is presented, based on a numerical synthesizing technique, which is different from using image recognition to separate trace O and trace X in the ionograms, and from using the electrical method to synthesize and detect circularly polarized waves. By replacing analog phase shifters and switches in existing ionosonde with digital phase shifters with different initial phase, 0°, +90°, −90°, circularly polarized waves are synthesized digitally within the range of 1-30 MHz, which eliminates the nonlinearity and expands the bandwidth of the ionosonde, and there is no need to switch the analog switches continuously. The new method has been successfully applied to CAS-DIS ionosonde and testing results show that the new digital method is capable of separating O wave and X wave well.</p>

scholarly journals Alfvén wave propagation and dissipation in a 3D-structured compressible plasma

2003 ◽  
Vol 412 (2) ◽  
pp. 529-539 ◽  
Author(s):  
F. Malara ◽  
M. F. De Franceschis ◽  
P. Veltri
Keyword(s):  
Wave Propagation ◽  
Alfven Wave ◽  
Compressible Plasma
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