THE EXPERIMENTALLY OBSERVED OPTICAL COTTON–MOUTON EFFECT: EVIDENCE FOR THE PHOTON'S LONGITUDINAL MAGNETIC FIELD, B(3)

The recent experimental observation of the optical Cotton–Mouton effect is consistent with the induction of magnetization by the longitudinal component of the photon's magnetic field, whose classical counterpart is the equivalent flux density B(3). In the optical Cotton–Mouton effect observed by Zon et al.,16 the field B(3) acts at second order and is independent of the polarization of the inducing laser beam propagating parallel to a permanent magnetic field. The optical Cotton–Mouton effect is therefore proportional to the laser intensity as observed.16

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Fast and Globally Convergent Nonlinear System Model for 3D Magnetostrictive Systems

Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation and Control of Adaptive Systems; Structural Health Monitoring; Keynote Presentation ◽

10.1115/smasis2014-7714 ◽

2014 ◽

Cited By ~ 1

Author(s):

Hafez Tari ◽

Marcelo J. Dapino

Keyword(s):

Magnetic Field ◽

Magnetic Flux ◽

Flux Density ◽

Error Function ◽

Second Order ◽

System Model ◽

Magnetic Flux Density ◽

Magnetostrictive Material ◽

Globally Convergent ◽

Direct Model

A globally convergent and fully coupled magnetomechanical model for 3D magnetostrictive systems is presented. In magnetostrictive actuators, magnetic field and stress inputs generate magnetic flux density and strain. We refer to models that follow this scheme as direct models (no relation to the direct magnetomechanical effect). In certain design and control situations, inverse models are necessary in which the magnetic field and stress are found from specified magnetic flux density and strains. This inversion typically involves an iterative procedure, which may be prone to convergence issues. An inverse model approach is proposed for arbitrary magnetostrictive materials. The inversion requirement is a continuous and second order differentiable direct model for any chosen magnetostrictive material. The approach is globally convergent, which makes it ideal for use in finite element frameworks. The premise of the proposed iterative system model is to constitute a recursive correction formula based on second order approximations of a novel scalar error function which allows to achieve a faster convergence rate. A continuation approach is then used to achieve global convergence for arbitrary input parameters. To illustrate, Galfenol is chosen as the magnetostrictive material, and analytical derivations of the Jacobian and Hessian matrices are presented. Finally, the computational efficiency of the proposed approach is shown to compare favorably against existing models.

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Compact Jets in 100 AGNs with the Strongest Broad-Band Variability of 1-22 GHz Spectra in 1997-2001

International Astronomical Union Colloquium ◽

10.1017/s0252921100030888 ◽

2002 ◽

Vol 184 ◽

pp. 297-298

Author(s):

Yu. A. Kovalev ◽

Y. Y. Kovalev ◽

N. A. Nizhelsky ◽

A. V. Bogdantsov

Keyword(s):

Magnetic Field ◽

Physical Model ◽

Flux Density ◽

Radio Telescope ◽

Longitudinal Magnetic Field ◽

Broad Band ◽

Radio Sources ◽

Spectral Evolution ◽

Model Interpretation ◽

Relativistic Jet

AbstractResults of monitoring observations at the radio telescope RATAN-600 and a model interpretation of instantaneous 1-22 GHz spectra at six frequencies for 100 selected AGNs are presented. The index of variability at these frequencies is shown for 550 sources monitored in 1997-2001 at 11 epochs. The spectra of the selected sources exhibit flux density variations of about 50% and up. The type of spectral evolution is similar for all the selected objects, favoring the same basic physical model. Model analysis shows that the nature of the radio sources and the observed variability behavior of the spectra can be explained by a model with a relativistic jet of parsec scale in a longitudinal magnetic field.

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GV/cm scale laser-magnetic resonant acceleration in vacuum

Laser and Particle Beams ◽

10.1017/s0263034617000507 ◽

2017 ◽

Vol 35 (3) ◽

pp. 520-527 ◽

Cited By ~ 1

Author(s):

Y. Zhang ◽

J.-L. Jiao ◽

B. Zhang ◽

Z.-M. Zhang ◽

Y.-Q. Gu

Keyword(s):

Magnetic Field ◽

Phase Difference ◽

Electron Bunch ◽

Longitudinal Magnetic Field ◽

Laser Intensity ◽

Resonant Condition ◽

Electron Accelerators ◽

Simulation Results ◽

Spatial Size ◽

Resonant Acceleration

AbstractResonant acceleration of electrons by a laser in the background of an extra longitudinal magnetic field is investigated analytically and numerically. The resonant condition is independent of laser intensity, and when satisfied, the energy gain is proportional to $a_0^2 $ and the square of phase difference. This process is mainly limited by the magnitude and spatial size of the extra magnetic field. Under the laboratory conditions, simulation results show that a monoenergetic and collimated electron bunch can still be obtained in ~ GV/cm scale, which sheds a light on the vacuum table-top laser-driven electron accelerators.

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The transverse magneto-resistance effect in single crystals of iron

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1927.0063 ◽

1927 ◽

Vol 114 (768) ◽

pp. 611-619 ◽

Cited By ~ 14

Keyword(s):

Magnetic Field ◽

Crystal Structure ◽

Single Crystals ◽

Longitudinal Magnetic Field ◽

Transverse Magnetic ◽

Longitudinal Component ◽

Initial Increase ◽

Direct Influence ◽

Magneto Resistance ◽

The Magnetic Field

The experiments to be described in this paper, deal with the change of resistance of single crystals of iron caused by a magnetic field perpendicular to the direction of the current. In two earlier papers, it has been shown that both the phenomena of magneto-striction and change of resistance in a longitudinal magnetic field were very different when measured in different directions in the crystal. And the results led to the conclusion that the change of resistance in the latter case was due to the change of orientation of the atoms accompanying magnetization, any direct influence of the field on the resistance being negligible. With these results in mind it seemed important to determine how the change of resistance in a transverse magnetic field depended on the crystal structure, and whether this more complicated effect, dealing with two directions in the crystal instead of one, would fit in with the results previously obtained. Many measurements of this phenomenon have been made for soft iron, and it has generally been accepted that there is only a decrease of resistance, slow at first, then rapid, finally approaching a saturation value. Occasionally an initial increase has been found, but this has not been considered genuine, being accounted for by the presence of a longitudinal component of magnetization due to imperfect orientation of the rod in the magnetic field.

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Vacuum Birefringence in the Fields of a Current Coil and a Guided Electromagnetic Wave

Ukrainian Journal of Physics ◽

10.15407/ujpe63.11.979 ◽

2018 ◽

Vol 63 (11) ◽

pp. 979 ◽

Cited By ~ 1

Author(s):

O. Novak ◽

M. Diachenko ◽

E. Padusenko ◽

R. Kholodov

Keyword(s):

Magnetic Field ◽

Electromagnetic Wave ◽

Magnetic Fields ◽

Laser Beam ◽

Radio Frequency ◽

Experimental Observation ◽

Current Coil ◽

Linearly Polarized ◽

Birefringence Effect ◽

A Current

The vacuum birefringence effect in magnetic fields generated by either a laser-driven capacitor-coil generator or an electromagnetic wave in a radio frequency guide has been theoretically studied. The ellipticity acquired by a linearly polarized laser beam propagating in those fields is calculated. The obtained results are compared with the parameters of the PVLAS experiment aimed at the experimental observation of the vacuum birefringence effect in a magnetic field.

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A second order calculation of the adiabatic invariant of a charged particle spiraling in a longitudinal magnetic field

Journal of Mathematical Physics ◽

10.1063/1.523796 ◽

1978 ◽

Vol 19 (5) ◽

pp. 937-941 ◽

Cited By ~ 2

Author(s):

R. Chehab

Keyword(s):

Magnetic Field ◽

Charged Particle ◽

Longitudinal Magnetic Field ◽

Second Order ◽

Adiabatic Invariant ◽

Order Calculation

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A novel analytical calculation of magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-201505 ◽

2020 ◽

pp. 1-15

Author(s):

Jianqi Li ◽

Yu Zhou ◽

Jianying Li

Keyword(s):

Magnetic Field ◽

Conformal Mapping ◽

Permanent Magnet ◽

Flux Density ◽

Analytical Method ◽

Electromotive Force ◽

Analytical Calculation ◽

Air Gap ◽

Permanent Magnet Machines ◽

Peak Value

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.

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