Magnetooptic resonances in dichroism and birefringence related to the self-alignment of atoms in a discharge at an arbitrary orientation of the magnetic field

2001 ◽  
Vol 91 (2) ◽  
pp. 288-294 ◽  
Author(s):  
É. G. Saprykin ◽  
S. N. Seleznev ◽  
V. A. Sorokin
Keyword(s):  
Magnetic Field ◽  
The Self ◽  
Arbitrary Orientation ◽  
The Magnetic Field

Numerical study of toroidal magnetic field on the self-gravitating protoplanetary disks

2020 ◽  
Vol 29 (09) ◽  
pp. 2050067
Author(s):  
Hanifeh Ghanbarnejad ◽  
Maryam Ghasemnezhad
Keyword(s):  
Magnetic Field ◽  
Accretion Disks ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Ohmic Heating ◽  
The Self ◽  
Toroidal Magnetic Field ◽  
Heating Process ◽  
Heating And Cooling ◽  
The Magnetic Field

In this paper, we study the self-gravitating accretion disks by considering the toroidal component of magnetic field, [Formula: see text] and wind/outflow in the flow and also investigate the effect of two parameters, [Formula: see text] and [Formula: see text] corresponding to magnetic field on the latitudinal structure of such accretion disks. The cooling of the disk is parameterized simply as, [Formula: see text] (where [Formula: see text] is the internal energy and [Formula: see text] is the cooling timescale and [Formula: see text] is a free constant) and the heating rate is decomposed into two components, magnetic field and viscosity dissipations. We have shown that when the toroidal magnetic field becomes stronger, the heating process (viscous and resistivity) and the radiative cooling rate increase. Ohmic heating is much bigger than viscous heating and cooling, so we must consider the role of the magnetic field in the energy equation. Our numerical solutions show that the thickness of the disk decreases with strong toroidal component of magnetic field. The magnetic field leads to production of the outflow in the low latitude. So, by increasing the toroidal component of the magnetic field, the regions which belong to inflow decrease and the disk is cooled.

Effect of The Orientation of The Magnetic Field on The Giant Magnetoresistance of Fe/Cr Superlattices

1995 ◽  
Vol 384 ◽  
Author(s):  
V.V. Ustinov ◽  
V.I. Minin ◽  
L.N. Romashev ◽  
A.B. Semerikov ◽  
A.R. Del
Keyword(s):  
Magnetic Field ◽  
Molecular Beam Epitaxy ◽  
Field Strength ◽  
Magnetization Curve ◽  
Giant Magnetoresistance ◽  
Molecular Beam ◽  
Orientation Dependence ◽  
Arbitrary Orientation ◽  
Strength Dependence ◽  
The Magnetic Field

ABSTRACTWe study the magnetoresistance of [Fe/Cr]30/MgO superlattices grown by molecular beam epitaxy at a various magnetic field directions. The theory of the orientation dependence of the effect is developed. It is shown that the magnetic field strength dependence of magnetoresistance can be calculated for arbitrary orientation of magnetic field if this dependence is known for in-plane and perpendicular-to-plane magnetic fields. It is noted that the magnetization curve can be obtained by making use of the results of the magnetoresistance measurements.

scholarly journals Ellipsoids (v1.0): 3D Magnetic modelling of ellipsoidal bodies

2017 ◽  
Author(s):  
Diego Takahashi Tomazella ◽  
Vanderlei C. Oliveira Jr.
Keyword(s):  
Magnetic Field ◽  
Synthetic Data ◽  
The Self ◽  
Geological Body ◽  
Python Language ◽  
Wide Range ◽  
Magnetic Modelling ◽  
And Inversion ◽  
The Magnetic Field ◽  
Limiting Value

Abstract. A considerable amount of literature has been published on the magnetic modelling of uniformly magnetized ellipsoids since the second half of the nineteenth century. Ellipsoids have flexibility to represent a wide range of geometrical forms, are the only known bodies which can be uniformly magnetized in the presence of a uniform inducing field and are the only bodies for which the self-demagnetization can be treated analytically. This property makes ellipsoids particularly useful for modelling compact orebodies having high susceptibility. In this case, neglecting the self-demagnetization may strongly mislead the interpretation of these bodies by using magnetic methods. A number of previous studies consider that the self-demagnetization can be neglected for the case in which the geological body has an isotropic susceptibility lower than or equal to 0.1 SI. This limiting value, however, seems to be determined empirically and there has been no discussion about how this value was determined. Besides, the geoscientific community lacks an easy-to-use tool to simulate the magnetic field produced by uniformly magnetized ellipsoids. Here, we present an integrated review of the magnetic modelling of arbitrarily oriented triaxial, prolate and oblate ellipsoids. Our review includes ellipsoids with both induced and remanent magnetization, as well as with isotropic or anisotropic susceptibility. We also propose a way of determining the isotropic susceptibility above which the self-demagnetization must be taken into consideration. Tests with synthetic data validate our approach. Finally, we provide a set of routines to model the magnetic field produced by ellipsoids. The routines are written in Python language as part of the Fatiando a Terra, which is an open-source library for modelling and inversion in geophysics.

Magnetohydrodynamic duct flow in a uniform transverse magnetic field of arbitrary orientation

1971 ◽  
Vol 48 (3) ◽  
pp. 429-461 ◽  
Author(s):  
C. J. N. Alty
Keyword(s):  
Magnetic Field ◽  
Pressure Gradient ◽  
Transverse Magnetic Field ◽  
Potential Distribution ◽  
Transverse Magnetic ◽  
Arbitrary Orientation ◽  
Axial Pressure Gradient ◽  
Viscous Shear ◽  
The Magnetic Field ◽  
Pressure Driven

The paper presents an approximate analysis for high Hartmann number of the flow of an electrically conducting, incompressible fluid in a duct of square crosssection, having one pair of opposite walls insulating, and the other pair perfectly conducting and inclined at arbitrary orientation to a uniform transverse magnetic field. The flow is considered to be either pressure-driven with the two perfectly conducting electrodes short-circuited together or electrically driven by a potential difference applied between these electrodes in the absence of axial pressure gradient. The paper describes experiments on the pressure-driven, short circuited case using mercury in copper ducts to investigate the variation of the streamwise pressure gradient and of the potential distribution along one insulating wall with orientation, magnetic field and flow rate.At general orientations the analysis suggests and the experiments confirm the existence of regions of stationary fluid in the corners of the duct, together with viscous shear layers parallel to the magnetic field. For the case in which the electrodes are parallel to the magnetic field the experimental results for the pressure gradient, but not those for the potential distribution, agree reasonably well with Hunt & Stewartson's (1965) asymptotic solution. Both pressure gradient and potential results agree closely with the analysis by Hunt (1965) of the case in which the electrodes are perpendicular to the magnetic field.

scholarly journals On Reactive Force in Thin Unclosed Conductor and Displacement Current

2021 ◽  
Vol 3 (5) ◽  
pp. 7-10
Author(s):  
Sergey A. Gerasimov
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Electromagnetic Fields ◽  
Momentum Density ◽  
Linear Momentum ◽  
The Self ◽  
Displacement Current ◽  
Reactive Force ◽  
Self Force ◽  
The Magnetic Field

The linear momentum density carried by electromagnetic fields creates the hidden force acting on the displacement current between ends of an unclosed conductor with alternative electric current. This force compensates the self-force exerted by the unclosed conductor with zero thin. The magnetic field produced by displacement current does not contribute to the force acting on the conductor. The unclosed conductor can move under action of the self-force. At small heights of cylindrical open conductor, the reactive force equivalent to the self-force becomes very large

Thermal Entanglement and Dense Coding in Two-Qubit XX Spin Chain under an Arbitrary Magnetic Field

2013 ◽  
Vol 446-447 ◽  
pp. 986-991
Author(s):  
Hai Lin Huang ◽  
Zhao Yu Sun
Keyword(s):  
Magnetic Field ◽  
Thermal State ◽  
Arbitrary Orientation ◽  
Dense Coding ◽  
Thermal Entanglement ◽  
Optimal Direction ◽  
Optimal Dense Coding ◽  
Arbitrary Magnetic Field ◽  
Coding Capacity ◽  
The Magnetic Field

The effect of arbitrary orientation in the magnetic field on the entanglement and dense coding of a two-qubit XX model is investigated. The concurrence and optimal dense coding capacity are calculated for different orientations of the magnetic field. It is found that the entanglement can be maximized by rotating the magnetic field to an optimal direction at given temperature. Furthermore, there exists critical concurrence Cc, beyond which the thermal state is unfeasible for optimal dense coding.

Focusing of a dark hollow Gaussian electromagnetic beam in a magnetoplasma

2009 ◽  
Vol 75 (6) ◽  
pp. 731-748 ◽  
Author(s):  
MAHENDRA SINGH SODHA ◽  
S. K. MISHRA ◽  
SHIKHA MISRA
Keyword(s):  
Magnetic Field ◽  
Radial Distance ◽  
The Self ◽  
Electromagnetic Beam ◽  
Dimensionless Radius ◽  
Critical Curves ◽  
Self Focusing ◽  
Subsequent Discussion ◽  
The Magnetic Field

AbstractThis paper presents an analysis and subsequent discussion of the self focusing of a dark hollow Gaussian electromagnetic beam (HGB) in a magnetoplasma, considering ponderomotive and collisional nonlinearities. A paraxial-like approach, in which the relevant parameters are expanded in terms of radial distance from the maximum of the irradiance rather than that from the axis, has been adopted to analyze the propagation of the HGB. The nature of self focusing is highlighted through the critical curves as a plot of dimensionless radius versus power of the beam. The effect of the magnetic field and the nature of the nonlinearity on self focusing of various order HGBs has also been explored.

scholarly journals Ellipsoids (v1.0): 3-D magnetic modelling of ellipsoidal bodies

2017 ◽  
Vol 10 (9) ◽  
pp. 3591-3608 ◽  
Author(s):  
Diego Takahashi ◽  
Vanderlei C. Oliveira Jr.
Keyword(s):  
Magnetic Field ◽  
Synthetic Data ◽  
The Self ◽  
Geological Body ◽  
Python Language ◽  
Wide Range ◽  
Magnetic Modelling ◽  
And Inversion ◽  
The Magnetic Field ◽  
Limiting Value

Abstract. A considerable amount of literature has been published on the magnetic modelling of uniformly magnetized ellipsoids since the second half of the nineteenth century. Ellipsoids have flexibility to represent a wide range of geometrical forms, are the only known bodies which can be uniformly magnetized in the presence of a uniform inducing field and are the only finite bodies for which the self-demagnetization can be treated analytically. This property makes ellipsoids particularly useful for modelling compact orebodies having high susceptibility. In this case, neglecting the self-demagnetization may strongly mislead the interpretation of these bodies by using magnetic methods. A number of previous studies consider that the self-demagnetization can be neglected for the case in which the geological body has an isotropic susceptibility lower than or equal to 0.1 SI. This limiting value, however, seems to be determined empirically and there has been no discussion about how this value was determined. In addition, the geoscientific community lacks an easy-to-use tool to simulate the magnetic field produced by uniformly magnetized ellipsoids. Here, we present an integrated review of the magnetic modelling of arbitrarily oriented triaxial, prolate and oblate ellipsoids. Our review includes ellipsoids with both induced and remanent magnetization, as well as with isotropic or anisotropic susceptibility. We also discuss the ambiguity between confocal ellipsoids with the same magnetic moment and propose a way of determining the isotropic susceptibility above which the self-demagnetization must be taken into consideration. Tests with synthetic data validate our approach. Finally, we provide a set of routines to model the magnetic field produced by ellipsoids. The routines are written in Python language as part of the Fatiando a Terra, which is an open-source library for modelling and inversion in geophysics.

Spontaneous excitation of magnetic fields and collapse dynamics in a Langmuir plasma

1981 ◽  
Vol 26 (1) ◽  
pp. 123-146 ◽  
Author(s):  
M. Kono ◽  
M. M. Škorić ◽  
D. Ter Haar
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Ponderomotive Force ◽  
Modulational Instability ◽  
The Self ◽  
Spontaneous Generation ◽  
Magnetic Field Generation ◽  
Langmuir Waves ◽  
Field Generation ◽  
The Magnetic Field

We discuss various aspects of the spontaneous generation of magnetic fields in a Langmuir plasma. We first of all show that the correct general expression for the ponderomotive force leads to the solenoidal current responsible for the magnetic-field generation. We derive the ponderomotive-force expression and also the magnetic-field generation equations from a two-time-scale two-fluid description. We also use a kinetic approach to derive the magnetic-field generation equations. We discuss the stability of monochromatic Langmuir waves and show that they are subject to both the ordinary modulational instability and to a magneto-modulational instability. We show that the coupled nonlinear equations describing the electric field strength amplitude, the plasma density, and the self-generated magnetic field can, under certain conditions, be reduced to a generalized cubic nonlinear Schrodinger equation. We finally show, by using a virial theorem, that the self-generated magnetic field does not stabilize the wave collapse.

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