Far-Field Potential of a Test Charge in an Inhomogeneous and Magnetized Plasma

1974 ◽  
Vol 52 (3) ◽  
pp. 281-283 ◽  
Author(s):  
P. K. Shukla ◽  
K. H. Spatschek ◽  
M. Y. Yu
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Inhomogeneous Plasma ◽  
Field Potential ◽  
Magnetized Plasma ◽  
The Other ◽  
Far Field ◽  
Homogeneous Plasma ◽  
Test Charge ◽  
Stationary Test

It is shown that a stationary test charge in a magnetized inhomogeneous plasma has a far-field potential which falls off as the inverse cube of the distance between the test charge and an observer who is located in a direction perpendicular to both the density gradient and the external magnetic field. On the other hand, the effect of an external magnetic field parallel to the velocity of a slowly moving test charge in a homogeneous plasma is shown to be insignificant.

scholarly journals Enhanced terahertz radiation generation by two-color laser pulses propagating in plasma

2016 ◽  
Vol 34 (2) ◽  
pp. 378-383 ◽  
Author(s):  
N.K. Verma ◽  
P. Jha
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Numerical Model ◽  
Laser Pulses ◽  
Magnetized Plasma ◽  
Thz Radiation ◽  
Homogeneous Plasma ◽  
One Dimensional ◽  
Radiation Generation ◽  
Transverse Electromagnetic

AbstractA one-dimensional (1D) numerical model for studying enhanced terahertz (THz) radiation generation by mixing of ordinary and extraordinary modes of two-color laser pulses propagating in magnetized plasma has been presented. The direction of the static external magnetic field is such that one of the two laser pulses propagates in the extraordinary mode, while the other pulse propagates in the ordinary mode, through homogeneous plasma. A transverse electromagnetic wave with frequency in the THz range is generated due to the presence of the external magnetic field. It is observed that larger amplitude THz radiation can be generated by mixing of the ordinary and extraordinary modes of the two-color laser pulses as compared with the single laser pulse propagating in the extraordinary mode. Further, 2D simulations using the XOOPIC code show that the fields obtained via simulation study are compatible with those obtained from the numerical model.

Electromagnetic wave backscattering across a magnetic field in a bounded plasma

1979 ◽  
Vol 22 (1) ◽  
pp. 85-96
Author(s):  
Joseph E. Willett ◽  
Sinan Bilikmen ◽  
Behrooz Maraghechi
Keyword(s):  
Magnetic Field ◽  
Numerical Study ◽  
Magnetized Plasma ◽  
Absolute Instability ◽  
Moment Equations ◽  
Homogeneous Plasma ◽  
Coupled Equations ◽  
Bounded Plasma ◽  
The Moment ◽  
The Magnetic Field

The stimulated backscattering of electromagnetic ordinary waves from extraordinary waves propagating normal to a magnetic field in a plasma of finite length is studied. A pair of coupled differential equations for the amplitudes of the backscattered and scatterer waves is derived from Maxwell's equations and the moment equations for an inhomogeneous magnetized plasma. Solution of the coupled equations for a homogeneous plasma yields an expression for the growth rate of the absolute instability as a function of plasma length and damping rates of the product waves. The convective regime in which only spatial amplification occurs is discussed. A numerical study of the effects of the magnetic field on Raman and Brillouin backscattering is presented.

Schwingung eines Plasmazylinders in einem axialen Magnetfeld II

1960 ◽  
Vol 15 (3) ◽  
pp. 220-226 ◽  
Author(s):  
Klaus Körper
Keyword(s):  
Magnetic Field ◽  
Refractive Index ◽  
External Magnetic Field ◽  
Field Strength ◽  
Axial Magnetic Field ◽  
Surface Current ◽  
The Other ◽  
Plasma Cylinder ◽  
Resonance Frequencies ◽  
The Magnetic Field

Radial oscillations are excited in a homogeneous infinite plasma cylinder in a homogeneous axial magnetic field by a surface current which is homogeneous in the axial and azimuthal directions. The modes of oscillations corresponding to the axial and azimuthal components of current are not coupled, and so they may be analysed separately. The magnetic field in the plasma and vacuum is obtained, and the indices of refraction for both types of oscillations are discussed thoroughly. When the currents are parallel to the external magnetic field, the oscillations are characterized by the refractive index of Eccles. On the other hand, when the current is perpendicular to the magnetic field two resonance frequencies exist, which depend on the density of the plasma and the magnetic field strength. — In the latter case the radial characteristic oscillations of the plasma cylinder in an external magnetic field are considered.

Tunable properties of one-dimensional photonic crystals that incorporate a defect layer of a magnetized plasma

2017 ◽  
Vol 31 (31) ◽  
pp. 1750239 ◽  
Author(s):  
Arafa H. Aly ◽  
Hussein A. Elsayed ◽  
Ayman A. Ameen ◽  
S. H. Mohamed
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Plasma Layer ◽  
Photonic Band Gap ◽  
Defect Layer ◽  
Magnetized Plasma ◽  
Characteristic Matrix ◽  
Angle Of Incidence ◽  
One Dimensional ◽  
Photonic Band

In this paper, we theoretically investigate the transmittance characteristics of one-dimensional defective photonic crystal in microwave radiations based on the fundamentals of the characteristic matrix method. Here, the defect layer is magnetized plasma. The numerical results show the appearance of defect peaks inside the Photonic Band Gap. The external magnetic field has a significant effect on the permittivity of the defect layer. Therefore, the position and intensity of the defect peak are strongly affected by the external magnetic field. Moreover, we have investigated the different parameters on the defect peaks as the plasma density, the thickness of the plasma layer and the angle of incidence. Wherefore, the proposed structure could be the cornerstone for many applications in microwave regions such as narrowband filters.

scholarly journals Magnetic properties of supraconductors

1936 ◽  
Vol 154 (882) ◽  
pp. 378-385 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
External Magnetic Field ◽  
Copper Wire ◽  
Thermal Contact ◽  
Threshold Value ◽  
Test Tube ◽  
The Other ◽  
Longitudinal Field ◽  
Thick Wire

Mendelssohn and Babbitt observed that the induction in solid and hollow tin spheres which became supraconductive in an external magnetic field did not fall quite to zero, but that part of the magnetic flux was “frozen in” at the threshold value. This behaviour could be explained by considerations based on the shape of the specimen, although it was not certain if this was the only reason for the effect. It seemed therefore that it would be of interest to investigate specimens of a shape which assured simpler conditions, such as long rods in a longitudinal field, in addition to extending the experiments to a greater number of supraconducting substances. Method The same two helium liquefiers with which the previous experiments were carried out were used again. The specimens employed were in the form of long rods attached by a short thick wire of electrolytic copper to the helium container. The wire was autogenously welded to one end of the specimen, the other end of the copper wire being soldered to the helium container. In the case of mercury the metal was contained in a test tube held independently, into which a copper wire dipped and made thermal contact. A coil one layer thick of 47 s. w. g. copper wire was wound round the middle of each specimen, the ends being connected to a ballastic galvanometer.

Stimulated backscattering of electromagnetic ordinary waves from extraordinary waves below the upper hybrid frequency

1979 ◽  
Vol 21 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Behrooz Maraghechi ◽  
Joseph E. Willett
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Static Magnetic Field ◽  
Inhomogeneous Plasma ◽  
Extraordinary Wave ◽  
Threshold Power ◽  
Ordinary Wave ◽  
Homogeneous Plasma ◽  
Parametric Decay ◽  
Hybrid Frequency

The parametric decay of an intense electromagnetic ordinary wave, propagating perpendicular to a uniform static magnetic field, into an extraordinary wave and a backscattered ordinary wave is investigated. Formulae are derived for the growth rate and threshold power associated with the instability in a homogeneous plasma. An analysis of the spatial amplification of the decay waves in an inhomogeneous plasma is presented. The effects of the uniform static magnetic field on the backscattering in both homogeneous and inhomogeneous plasmas are studied numerically.

scholarly journals Switching of perpendicularly polarized nanomagnets with spin orbit torque without an external magnetic field by engineering a tilted anisotropy

2015 ◽  
Vol 112 (33) ◽  
pp. 10310-10315 ◽  
Author(s):  
Long You ◽  
OukJae Lee ◽  
Debanjan Bhowmik ◽  
Dominic Labanowski ◽  
Jeongmin Hong ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Data Storage ◽  
Easy Axis ◽  
Film Plane ◽  
The Other ◽  
Spin Orbit ◽  
Applied Current ◽  
Density Data ◽  
Magnetic Easy Axis

Spin orbit torque (SOT) provides an efficient way to significantly reduce the current required for switching nanomagnets. However, SOT generated by an in-plane current cannot deterministically switch a perpendicularly polarized magnet due to symmetry reasons. On the other hand, perpendicularly polarized magnets are preferred over in-plane magnets for high-density data storage applications due to their significantly larger thermal stability in ultrascaled dimensions. Here, we show that it is possible to switch a perpendicularly polarized magnet by SOT without needing an external magnetic field. This is accomplished by engineering an anisotropy in the magnets such that the magnetic easy axis slightly tilts away from the direction, normal to the film plane. Such a tilted anisotropy breaks the symmetry of the problem and makes it possible to switch the magnet deterministically. Using a simple Ta/CoFeB/MgO/Ta heterostructure, we demonstrate reversible switching of the magnetization by reversing the polarity of the applied current. This demonstration presents a previously unidentified approach for controlling nanomagnets with SOT.

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