SURFACE WAVES ALONG AN AXIALLY MAGNETIZED PLASMA COLUMN: I. SYMMETRIC MODES

1967 ◽  
Vol 45 (9) ◽  
pp. 2889-2911 ◽  
Author(s):  
G. L. Yip ◽  
S. R. Seshadri
Keyword(s):  
Magnetic Field ◽  
Surface Wave ◽  
Resonant Frequency ◽  
Surface Waves ◽  
Infinite Number ◽  
Applied Magnetic Field ◽  
Cold Plasma ◽  
Magnetized Plasma ◽  
Wave Power ◽  
Point Electric Dipole

The characteristics of surface waves excited by an axially oriented point electric dipole situated along the axis of an infinitely long; and axially magnetized column of uniform cold plasma are investigated. The surface waves are found to be slow waves and exist only below the upper hybrid resonant frequency. In the gyromagnetic and plasma resonance regions, the existence of an infinite number of discrete modes is noted. The dispersion curves are presented for different values of the strength of the applied magnetic field and the column radius. Also, the power transported by the surface waves is evaluated and is found to become infinite in the two resonance frequency regions. A technique for the removal of this singularity in the surface wave power is indicated.

scholarly journals Stagnation of electron flow by a nonlinearly generated whistler wave

2017 ◽  
Vol 83 (2) ◽  
Author(s):  
Toshihiro Taguchi ◽  
Thomas M. Antonsen ◽  
Kunioki Mima
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Applied Magnetic Field ◽  
Large Amplitude ◽  
Cold Plasma ◽  
Relativistic Electron Beam ◽  
Electron Flow ◽  
Magnetized Plasma ◽  
Beam Transport ◽  
Electron Beam Transport

Relativistic electron beam transport through a high-density, magnetized plasma is studied numerically and theoretically. An electron beam injected into a cold plasma excites Weibel and two-stream instabilities that heat the beam and saturate. In the absence of an applied magnetic field, the heated beam continues to propagate. However, when a magnetic field of particular strength is applied along the direction of beam propagation, a secondary instability of off-angle whistler modes is excited. These modes then couple nonlinearly creating a large amplitude parallel-propagating whistler that stops the beam. Here, we will show these phenomena in detail and explain the mechanism of whistler mediated beam stagnation.

scholarly journals Terahertz radiation by self-focused amplitude-modulated Gaussian laser beam in magnetized ripple density plasma

2015 ◽  
Vol 33 (4) ◽  
pp. 741-747 ◽  
Author(s):  
Ram Kishor Singh ◽  
R. P. Sharma
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Applied Magnetic Field ◽  
Magnetized Plasma ◽  
Thz Radiation ◽  
Gaussian Laser Beam ◽  
Spatial Profile ◽  
Self Focusing ◽  
Oscillatory Velocity ◽  
Density Plasma

AbstractThis paper presents a theoretical model for efficient terahertz (THz) radiation by self-focused amplitude-modulated laser beam in preformed ripple density plasma. The density of plasma is modified due to ponderomotive nonlinearity which arises because of the nonuniform spatial profile of the laser beam in magnetized plasma and leads to the self-focusing of the laser beam. The rate of self-focusing depends on the intensity of the amplitude-modulated beam as well as on the externally applied magnetic field strength. The electron also experiences time-dependent ponderomotive force by the laser beam at modulated frequency. A nonlinear current at THz frequency arises on account of the coupling between the ripple density plasma and nonlinear oscillatory velocity of the electrons. The yield of the generated THz radiation enhances with enhancement in self-focusing of the laser beam and applied magnetic field.

Transmission characteristics of terahertz Bessel vortex beams through a multi-layered anisotropic magnetized plasma slab

2021 ◽  
Author(s):  
Haiying Li ◽  
Jiachen Tong ◽  
Wei Ding ◽  
Bing Xu ◽  
Lu Bai
Keyword(s):  
Magnetic Field ◽  
Plasma Density ◽  
Applied Magnetic Field ◽  
Incident Angle ◽  
Polarization State ◽  
Major Effect ◽  
Magnetized Plasma ◽  
Transmitted Beam ◽  
Plasma Slab ◽  
Vortex Beams

Abstract The transmission of terahertz (THz) Bessel vortex beams through a multi-layered anisotropic magnetized plasma slab is investigated by using a hybrid method of cylindrical vector wave functions (CVWFs) and Fourier transform. On the basis of the electromagnetic boundary conditions on each interface, a cascade form of expansion coefficients of the reflected and transmitted fields is obtained. Taking a double Gaussian distribution of the plasma density as an example, the influences of the applied magnetic field, the incident angle and polarization mode of the incident beams on the magnitude, OAM mode and polarization of the transmitted beams are analyzed in detail. The results indicate that the applied magnetic field has a major effect upon the polarization state of the transmitted fields but not upon the transmitted OAM spectrum. The incident angle has a powerful influence upon both the amplitude profile and the OAM spectrum of the transmitted beam. Furthermore, for multiple coaxial vortex beams, an increase of the maximum value of the plasma density causes more remarkable distortion of both the profile and OAM spectrum of the transmitted beam. This research makes a stable foundation for the THz OAM multiplexing/demultiplexing technology in magnetized plasma environment.

scholarly journals ON SURFACE WAVES IN A FINITELY DEFORMED MAGNETOELASTIC HALF-SPACE

2011 ◽  
Vol 03 (04) ◽  
pp. 633-665 ◽  
Author(s):  
P. SAXENA ◽  
R. W. OGDEN
Keyword(s):  
Magnetic Field ◽  
Wave Propagation ◽  
Surface Wave ◽  
Surface Waves ◽  
Half Space ◽  
Wave Speed ◽  
Sagittal Plane ◽  
Isotropic Energy ◽  
Surface Wave Propagation ◽  
Homogeneous Strain

Rayleigh-type surface waves propagating in an incompressible isotropic half-space of nonconducting magnetoelastic material are studied for a half-space subjected to a finite pure homogeneous strain and a uniform magnetic field. First, the equations and boundary conditions governing linearized incremental motions superimposed on an initial motion and underlying electromagnetic field are derived and then specialized to the quasimagnetostatic approximation. The magnetoelastic material properties are characterized in terms of a "total" isotropic energy density function that depends on both the deformation and a Lagrangian measure of the magnetic induction. The problem of surface wave propagation is then analyzed for different directions of the initial magnetic field and for a simple constitutive model of a magnetoelastic material in order to evaluate the combined effect of the finite deformation and magnetic field on the surface wave speed. It is found that a magnetic field in the considered (sagittal) plane in general destabilizes the material compared with the situation in the absence of a magnetic field, and a magnetic field applied in the direction of wave propagation is more destabilizing than that applied perpendicular to it.

Magneto-acoustic surface waves on current sheets

1994 ◽  
Vol 51 (2) ◽  
pp. 221-232 ◽  
Author(s):  
N. F. Cramer
Keyword(s):  
Magnetic Field ◽  
Surface Wave ◽  
Surface Waves ◽  
Constant Amplitude ◽  
Current Sheets ◽  
Change Of Direction ◽  
Acoustic Surface Waves ◽  
Resonance Damping ◽  
Arbitrary Change ◽  
The Magnetic Field

The theory of linear magneto-acoustic surface waves is investigated for current sheets across which the magnetic field has an arbitrary change of direction: in the first place discontinuously, and in the second place via a narrow transition region in which the magnetic field rotates with constant amplitude, so that the gas pressure remains constant. It is found that the effect of non-zero pressure is to eliminate the surface wave for certain angles of propagation and to allow the existence of an additional, slower, surface wave for other angles of propagation. The resonance damping of the surface waves when the current sheet is of small non-zero width is considered, and it is found that Alfvénresonance damping always occurs, as well as (for high β and certain angles of propagation) compressive- or cusp-resonance damping.

Solitary surface waves

1978 ◽  
Vol 20 (2) ◽  
pp. 183-188 ◽  
Author(s):  
M. Y. Yu ◽  
I. Zhelyazkov
Keyword(s):  
Surface Wave ◽  
Surface Waves ◽  
Half Space ◽  
Cold Plasma ◽  
Envelope Surface ◽  
Nonlinear Surface Waves ◽  
Nonlinear Surface ◽  
Wavenumber Spectrum

We consider nonlinear surface waves on a cold plasma half-space. It is found that for a certain region of the wavenumber spectrum, supersonic envelope surface wave solitons exist.

Relationship between directions of wave and energy propagation for cold plasma waves

1986 ◽  
Vol 36 (3) ◽  
pp. 341-356 ◽  
Author(s):  
Zdzislaw E. Musielak
Keyword(s):  
Magnetic Field ◽  
Wave Propagation ◽  
Cold Plasma ◽  
Plasma Waves ◽  
Hydrogen Atmosphere ◽  
Magnetized Plasma ◽  
Local Magnetic Field ◽  
Energy Propagation ◽  
Phase And Group Velocities ◽  
The Relationship

The dispersion relation for plasma waves is considered in the ‘cold’ plasma approximation. General formulae for the dependence of the phase and group velocities on the direction of wave propagation with respect to the local magnetic field are obtained for a cold magnetized plasma. The principal cold plasma resonances and cut-off frequencies are defined for an arbitrary angle and are used to establish basic regimes of frequency where the cold plasma waves can propagate or can be evanescent. The relationship between direction of wave and energy propagation, for cold plasma waves in hydrogen atmosphere, is presented in the form of angle diagrams (angle between group velocity and magnetic field versus angle between phase velocity and magnetic field) and polar diagrams (also referred to as ‘Friedrich's diagrams’ ) for different directions of wave propagation. Morphological features of the diagrams as well as some critical angles of propagation are discussed.

Transition Radiation from a Plasma Boundary

1972 ◽  
Vol 50 (19) ◽  
pp. 2244-2252 ◽  
Author(s):  
S. R. Seshadri
Keyword(s):  
Surface Wave ◽  
Resonant Frequency ◽  
Half Space ◽  
Particle Velocity ◽  
Free Space ◽  
Point Charge ◽  
Transition Radiation ◽  
Plasma Boundary ◽  
Wave Power ◽  
Space Wave

The transition radiation emitted by a point charge moving with a uniform velocity across a plane interface separating a half-space of plasma from another half-space of free space is investigated. The transition radiation is partly in the form of space waves and partly in the form of surface waves. The characteristics of these waves are discussed with the help of some typical numerical results. The surface-wave power is shown to be many orders larger than the space-wave power and near the surface-wave resonant frequency an increase in the particle velocity is found to decrease the surface-wave power.

TE SURFACE WAVES GUIDED BY A DIELECTRIC-COVERED METAL PLANE

1960 ◽  
Vol 38 (12) ◽  
pp. 1553-1559 ◽  
Author(s):  
D. Morris ◽  
A. G. Mungall
Keyword(s):  
Surface Wave ◽  
Surface Waves ◽  
Dielectric Layer ◽  
Wave Power ◽  
Comparison System ◽  
Phase Velocities ◽  
Te Mode ◽  
Simultaneous Existence

Investigations of the phase velocities of TE mode surface waves are described. The surface waves were excited over a sand-covered metal plane and the phase velocities of the first three TE modes determined as a function of the sand depth, at a frequency of about 9300 Mc/sec. A phase comparison system was used for the measurements. The simultaneous existence of two modes with different velocities, predicted theoretically for certain sand depths, was found experimentally.The variation of relative surface wave power carried above the dielectric layer with thickness of the layer is also discussed.

Solitary surface waves on a magnetized plasma cylinder

1985 ◽  
Vol 33 (1) ◽  
pp. 53-58 ◽  
Author(s):  
O. M. Gradov ◽  
L. Stenflo ◽  
D. Sünder
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Solitary Wave ◽  
Surface Waves ◽  
High Frequency ◽  
Axial Magnetic Field ◽  
Magnetized Plasma ◽  
Plasma Cylinder

We analyse high-frequency electrostatic solitary surface waves that propagate along a plasma cylinder in the presence of a constant axial magnetic field. The width of such a solitary wave, which is found to be inversely proportional to its amplitude, is expressed as a function of the magnitude of the external magnetic field.

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