THE ADMITTANCE OF AN INFINITE CYLINDRICAL ANTENNA IN A LOSSY INCOMPRESSIBLE, ANISOTROPIC PLASMA

1967 ◽  
Vol 45 (12) ◽  
pp. 4019-4038 ◽  
Author(s):  
Edmund K. Miller
Keyword(s):  
Magnetic Field ◽  
Free Space ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Floating Potential ◽  
Space Layer ◽  
Cylindrical Antenna ◽  
Warm Plasma ◽  
Positive Ion ◽  
Uniform Plasma

A numerical investigation of the admittance of an infinite, circular cylindrical antenna excited at a circumferential gap of nonzero thickness, and immersed in a lossy incompressible magnetoplasma with the antenna parallel to the static magnetic field is described. A concentric free-space layer (the vacuum sheath) which separates the antenna from the external uniform plasma is included in the analysis to approximate the positive ion sheath which may form about a body at floating potential in a warm plasma. The numerical results for the antenna admittance show that: (1) in the absence of a sheath, a sharp admittance maximum is found at the electron cyclotron frequency, with the maximum more pronounced when the plasma frequency exceeds the cyclotron frequency than for the converse case; (2) the vacuum sheath shifts upward in frequency and reduces in amplitude the admittance maximum which occurs for the sheathless case at the cyclotron frequency; (3) a kink or minimum in the admittance is found at the plasma frequency.

Coupling of Upper Hybrid Surface Plasmon Modes in Magnetoplasma Waveguide Structure

2021 ◽  
Vol 14 (2) ◽  
pp. 155-160
Keyword(s):  
High Frequency ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Single Mode ◽  
Homogeneous System ◽  
Slab Waveguide ◽  
Surface Modes ◽  
Plasma Slab ◽  
Warm Plasma ◽  
Hybrid Waves

Abstract: We investigate the spectra of high-frequency electrostatic surface electron plasmon oscillations propagating normal to a dc-magnetic field. These oscillations are supported by two identical magnetoplasma slabs separated by a vacuum slab. Propagation characteristics of surface magnetoplasma oscillations and their coupling are studied by simultaneously solving the homogeneous system of equations obtained by matching the electrostatic fields at the interfaces together with the warm plasma dielectric function of upper hybrid waves. We demonstrate the existence of two propagating magnetoplasma electrostatic surface modes (backward and forward modes). The backward mode emerges at frequency ω=ω_uh=√(ω_pe^2+ω_ce^2 ), where ω_pe and ω_ce are the electron plasma frequency and the electron cyclotron frequency, respectivily, and the forward propagating mode emerges at a lower frequency ω=ω_uh-ω_pe. The forward and backward surface modes become coupled and form a single mode at upper hybrid resonance quasi-static value ω=ω_uh/√2. Keywords: Upper hybrid modes, Plasma slab waveguide, Coupled plasmon surface modes.

Magnetic stabilization of transverse plasma instabilitiest

1971 ◽  
Vol 5 (3) ◽  
pp. 467-474 ◽  
Author(s):  
B. Buti ◽  
G. S. Lakhina
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Electron Plasma ◽  
Wave Number ◽  
Uniform External Magnetic Field ◽  
Magnetic Stabilization ◽  
Streaming Velocity ◽  
The Magnetic Field

Waves, propagating transverse to the direction of the streaming of a plasma in the presence of a uniform external magnetic field, are unstable if the streaming exceeds a certain minimum value. The magnetic field reduces the growth rate of this instability, and also increases the value of the minimum streaming velocity, above which the system is unstable. The thermal motions in the plasma, however, tend to stabilize the system if the magnetic field is weak (i.e. , Ω being the electron cyclotron frequency, k the characteristic wave-number, and Vt the thermal velocity); but, in case of strong magnetic field (i.e. ), they increase the growth rate, provided (ωp being the electron plasma frequency).

The admittance of an infinite cylindrical antenna in a lossy, compressible, anisotropic plasma

1968 ◽  
Vol 46 (9) ◽  
pp. 1109-1118 ◽  
Author(s):  
Edmund K. Miller
Keyword(s):  
Plasma Parameter ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Fourier Integral ◽  
Dipole Antenna ◽  
Cylindrical Antenna ◽  
Axis Parallel ◽  
E Region ◽  
Antenna Surface ◽  
Parameter Values

An analysis of the current on an infinite cylindrical dipole antenna which is excited across a circumferential gap of nonzero thickness and immersed in a lossy, compressible magnetoplasma with its axis parallel to the static magnetic field is described. Some numerical results are presented for the antenna admittance for the sheathless case, where the uniform magnetoplasma is in contact with the antenna surface. The admittance values are obtained from a numerical integration of the Fourier integral for the antenna current, and are given for plasma parameter values typical of the E region of the ionosphere.The admittance values obtained exhibit a maximum slightly above the electron cyclotron frequency, and in this regard are similar to the admittance when the magnetoplasma is incompressible but separated from the antenna by a free-space layer (the vacuum sheath). In addition, the admittance is found to have a slight minimum at the plasma frequency and to have a more pronounced minimum at the upper hybrid frequency where also the susceptance changes sign, these minima not being significantly affected by the plasma compressibility or vacuum sheath. These features of the calculated admittances are found to have a qualitative resemblance to experimental results obtained from antenna measurements in the ionosphere.

Stability of anisotropic plasmas to almost-perpendicular magnetosonic waves

1971 ◽  
Vol 6 (3) ◽  
pp. 495-512 ◽  
Author(s):  
R. W. Landau† ◽  
S. Cuperman
Keyword(s):  
Magnetic Field ◽  
Dispersion Relation ◽  
Simple Form ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Alfven Wave ◽  
Larmor Radius ◽  
Ion Plasma ◽  
The Stability ◽  
The Magnetic Field

The stability of anisotropic plasmas to the magnetosonic (or right-hand compressional Alfvén) wave, near the ion cyclotron frequency, propagating almost perpendicular to the magnetic field, is investigated. For this case, and for wavelengths larger than the ion Larmor radius and for large ion plasma frequency (w2p+ ≫ Ωp+) the dispersion relation is obtained in a simple form. It is shown that for T # T' (even T ≫ T) no instabifity occurs. The resonant ters are also included, and it is shown that there is no resonant instabifity, only damping.

Electrostatic waves potential at the plasma and upper-hybrid resonances

1981 ◽  
Vol 25 (2) ◽  
pp. 239-254 ◽  
Author(s):  
J. Thiel ◽  
R. Debrie
Keyword(s):  
Magnetic Field ◽  
Kinetic Theory ◽  
Dispersion Equation ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Electrostatic Waves ◽  
Ion Motion ◽  
Hybrid Resonance ◽  
Resonance Frequencies ◽  
The Magnetic Field

The potential created by an infinitesimal alternating dipole in a Maxwellian magnetoplasma is computed numerically at the plasma and upper-hybrid resonance frequencies when the latter extends from one to three times the electron cyclotron frequency. A linear full kinetic theory is used for a homogeneous magnetoplasma for which the forced ion motion and the collisions are neglected. The integral which gives the potential is evaluated by using the least-damping- roots (LDR) approximation, i.e. by neglecting the higher-order roots of the dispersion equation for electrostatic waves. Some characteristic potential patterns of dipoles parallel and perpendicular to the magnetic field are computed and comparisons with analytical results previously published are made. The numerical and analytical patterns are similar only at the plasma frequency when the dipole is parallel to the magnetic field.

Current distribution on a thin cylindrical antenna immersed in an isotropic compressible plasma

1968 ◽  
Vol 46 (8) ◽  
pp. 1013-1017 ◽  
Author(s):  
Richard L. Monroe
Keyword(s):  
Current Distribution ◽  
Integrodifferential Equation ◽  
Free Space ◽  
Plasma Frequency ◽  
Propagation Constant ◽  
Wave Number ◽  
Compressible Plasma ◽  
Cylindrical Antenna ◽  
Space Wave

An integrodifferential equation is derived for the current distribution along a thin, hollow, center-driven, cylindrical, perfectly conducting antenna immersed in an isotropic, compressible plasma. On the basis of this equation it is shown that the current distribution approaches sinusoidal form as the radius of the antenna approaches zero. The propagation constant for this current is approximately equal to the free-space wave number for most frequencies greater than the plasma frequency.

scholarly journals Current neutralization of ion beam rotating and propagating in plasma

1987 ◽  
Vol 5 (3) ◽  
pp. 481-493 ◽  
Author(s):  
Takayuki Aoki ◽  
Keishiro Niu
Keyword(s):  
Magnetic Field ◽  
Plasma Frequency ◽  
Ion Beam ◽  
Electron Plasma ◽  
Background Plasma ◽  
Plasma Current ◽  
Time Duration ◽  
Low Density Plasma ◽  
The Magnetic Field ◽  
Uniform Plasma

The current-neutralization fraction of a rotating and propagating light ion beam (LIB) injected into a low density plasma is investigated numerically. The beam space charge is essentially neutralized by a redistribution of the background plasma electrons in a time duration equal to the inverse of electron plasma frequency. When the density of the background plasma is comparable with that of the beam, incomplete current neutralization occurs because the strong magnetic field induced by the intense ion beam restricts the return plasma current.In the simulation, the ion beam and the background plasma are treated as the fluids coupled with Maxwell's equations and Ohm's law, including the effect of the magnetic field on electrical conductivity. The calculations assume that the ion beam is injected in an unsteady fashion into the uniform plasma. It is found that the return current strongly depends on the density of the background plasma. The beam deceleration and the acceleration of the beam head and tail are also considered.

The properties of photonic band gap and surface plasmon modes in the three-dimensional magnetized photonic crystals as the mixed polarized modes considered

2014 ◽  
Vol 81 (2) ◽  
Author(s):  
Hai-Feng Zhang ◽  
Shao-Bin Liu ◽  
Yu-Chi Jiang
Keyword(s):  
Magnetic Field ◽  
Dielectric Constant ◽  
Filling Factor ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Photonic Band Gap ◽  
Three Dimensional ◽  
Magnetized Plasma ◽  
Photonic Band ◽  
Plasmon Modes

In this paper, the properties of photonic band gap (PBG) and surface plasmon modes in the three-dimensional (3D) magnetized plasma photonic crystals (MPPCs) with face-centered-cubic (fcc) lattices are theoretically investigated based on the plane wave expansion (PWE) method, in which the homogeneous magnetized plasma spheres are immersed in the homogeneous dielectric background, as the Voigt effects of magnetized plasma are considered (the incidence electromagnetic wave vector is perpendicular to the external magnetic field at any time). The dispersive properties of all of the EM modes are studied because the PBG is not only for the extraordinary and ordinary modes but also for the mixed polarized modes. The equations for PBGs also are theoretically deduced. The numerical results show that the PBG and a flatbands region can be observed. The effects of the dielectric constant of dielectric background, filling factor, plasma frequency and plasma cyclotron frequency (the external magnetic field) on the dispersive properties of all of the EM modes in such 3D MPPCs are investigated in detail, respectively. Theoretical simulations show that the PBG can be manipulated by the parameters as mentioned above. Compared to the conventional dielectric-air PCs with similar structure, the larger PBG can be obtained in such 3D MPPCs. It is also shown that the upper edge of flatbands region cannot be tuned by the filling factor and dielectric constant of dielectric background, but it can be manipulated by the plasma frequency and plasma cyclotron frequency.

FREQUENCY VARIATION IN IONOSPHERIC CYCLOTRON HARMONIC SERIES OBTAINED BY THE ALOUETTE I SATELLITE

1966 ◽  
Vol 44 (5) ◽  
pp. 987-994 ◽  
Author(s):  
R. E. Barrington ◽  
Luise Herzberg
Keyword(s):  
Magnetic Field ◽  
Cyclotron Frequency ◽  
Harmonic Series ◽  
Frequency Variation ◽  
Theoretical Studies ◽  
Experimental Accuracy ◽  
Laboratory Results ◽  
Cyclotron Harmonics ◽  
Cyclotron Harmonic ◽  
Recent Laboratory

Ionograms produced by the Alouette I topside sounder frequently show well-developed series of cyclotron harmonics. Their frequencies have been determined from A (amplitude) scans with an accuracy of ~0.02 Mc/s for the sweep range of 1 to 6 Mc/s. In all cases examined, the frequencies of all of the members of the harmonic series are, within the experimental accuracy, integral multiples of the cyclotron frequency derived from the best present estimates of the earth's magnetic field strength at the satellite height. This result is discussed in the light of recent laboratory results and theoretical studies.

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