scholarly journals Impedance Operator Description of a Metasurface with Electric and Magnetic Dipoles

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Didier Felbacq
Keyword(s):  
Magnetic Dipole ◽  
Electric Dipole ◽  
Magnetic Dipoles ◽  
Effective Description ◽  
Impedance Operator

A metasurface made of a collection of nanoresonators characterized by an electric dipole and a magnetic dipole was studied in the regime where the wavelength is large with respect to the size of the resonators. An effective description in terms of an impedance operator was derived.

Electromagnetic energy of electric and magnetic dipoles

2013 ◽  
Vol 91 (7) ◽  
pp. 576-581 ◽  
Author(s):  
A.L. Kholmetskii ◽  
O.V. Missevitch ◽  
T. Yarman
Keyword(s):  
Electromagnetic Field ◽  
Magnetic Dipole ◽  
Electric Dipole ◽  
Dipole Moments ◽  
External Electromagnetic Field ◽  
Laboratory Frame ◽  
Relativistic Energy ◽  
Relativistic Case ◽  
Magnetic Dipoles ◽  
Relativistic Dependence

We derive a novel expression for the relativistic energy of electric and magnetic dipoles in an external electromagnetic field and discuss its implications. In particular, we find the relativistic dependence of the energy of a dipole on its velocity, v, and show that in the most convenient presentation of the energy (when the proper electric (p0) and magnetic (m0) dipole moments are involved, whereas the electric (E) and magnetic (B) fields are defined in the laboratory frame), its value essentially depends on the orientation of the velocity, v, with respect to vectors p0, E, and m0, B. To better understand the relativistic behavior of the energy of electric and magnetic dipoles, we introduce the notion of “latent” momentum of an electric dipole, in addition to the known concept of “hidden” momentum of a magnetic dipole. We finally show that the contribution of energy terms related to “hidden” and “latent” momenta of an electric or magnetic dipole is important in the relativistic case.

Hydromagnetic radiation from electric and magnetic dipoles in the magnetosphere

1969 ◽  
Vol 47 (16) ◽  
pp. 1643-1656 ◽  
Author(s):  
A. K. Sundaram
Keyword(s):  
Magnetic Field ◽  
Magnetic Dipole ◽  
Electric Dipole ◽  
Static Field ◽  
Radiation Characteristics ◽  
Magnetostatic Field ◽  
Magnetic Dipoles ◽  
The Waves ◽  
Dipole Sources ◽  
The Magnetic Field

This paper deals with the radiation characteristics of elementary electric and magnetic dipoles in a homogeneous, anisotropic, cold plasma of infinite extent with a uniform magnetostatic field. The cases treated include the electromagnetic sources taken parallel and perpendicular to the magnetostatic field. In all cases expressions for the field components are obtained which are valid at frequencies well below the ion cyclotron frequency. It is found that electric and magnetic dipole sources when oriented perpendicular to the magnetic field excite both ordinary and extraordinary modes. For the ordinary mode, the waves are guided in both directions within cones of small apex angle aligned with the static field. When the dipole sources are aligned with the magnetic field, it is found that the electric dipole excites only the ordinary mode leading to guided wave propagation, while the magnetic dipole excites only the extraordinary mode. In all cases the waves propagate at Alfvén speed. The radiation characteristics are isotropic for the extraordinary mode excited by the perpendicular electric dipole and are nearly isotropic for the aligned magnetic dipole. For other cases the radiated power is concentrated in opposite directions along the static field.

scholarly journals Electrostatic and magnetostatic fields of point dipoles revisited

2019 ◽  
Vol 65 (1) ◽  
pp. 71 ◽  
Author(s):  
Y. Muniz ◽  
Anderson José Fonseca ◽  
C. Farina
Keyword(s):  
Magnetic Dipole ◽  
Electric Dipole ◽  
Alternative Procedure ◽  
Dirac Delta ◽  
Delta Functions ◽  
Point Electric Dipole

After reviewing how the Dirac delta contributions to the electrostatic and magnetostatic fields of a point electric dipole and a point magnetic dipole are usually introduced, we present an alternative procedure for obtaining these terms based on a regularization prescription similar to that used in the computation of the transverse and longitudinal delta functions. We think this method may be useful for the students in other analogous calculations.

Electromagnetic radiation

2018 ◽  
Author(s):  
J. Pierrus
Keyword(s):  
Electromagnetic Radiation ◽  
Magnetic Dipole ◽  
Antenna Arrays ◽  
Electric Dipole ◽  
Free Electron ◽  
Vector Potential ◽  
Electric Quadrupole ◽  
Multipole Expansion ◽  
Multipole Moments

This chapter begins by expressing the multipole expansion of the dynamic vector potential A ( r, t) in terms of electric and magnetic multipole moments. Differentiation of A ( r, t) leads directly to the fields E ( r, t) and B ( r, t), which have a component transporting energy away from the sources to infinity. This component is called electromagnetic radiation and it arises only when electric charges experience an acceleration. A range of questions deal with the various types of radiation, including electric dipole and magnetic dipole–electric quadrupole. Larmor’s formula is applied in both its non-relativistic and relativistic forms. Also considered are some applications involving antennas, antenna arrays and the scattering of radiation by a free electron.

scholarly journals Studies of Systematic Limitations in the EDM Searches at Storage Rings

2016 ◽  
Vol 40 ◽  
pp. 1660093 ◽  
Author(s):  
Artem Saleev ◽  
Nikolai Nikolaev ◽  
Frank Rathmann
Keyword(s):  
Dipole Moment ◽  
Magnetic Dipole ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Magnetic Dipole Moment ◽  
Original Method ◽  
Spin Rotation ◽  
Systematic Effect ◽  
Systematic Effects ◽  
Magnetic Ring

Searches of the electric dipole moment (EDM) at a pure magnetic ring, like COSY, encounter strong background coming from magnetic dipole moment (MDM). The most troubling issue is the MDM spin rotation in the so-called imperfection, radial and longitudinal, B-fields. To study the systematic effects of the imperfection fields at COSY we proposed the original method which makes use of the two static solenoids acting as artificial imperfections. Perturbation of the spin tune caused by the spin kicks in the solenoids probes the systematic effect of cumulative spin rotation in the imperfection fields all over the ring. The spin tune is one of the most precise quantities measured presently at COSY at [Formula: see text] level. The method has been successfully tested in September 2014 run at COSY, unravelling strength of spin kicks in the ring’s imperfection fields at the level of [Formula: see text].

Nanowires in Magnetic Drug Targeting

2018 ◽  
Author(s):  
Zafar Ali Moghimi ◽  
Fazel Baniasadi ◽  
Gholamreza Naghieh
Keyword(s):  
Magnetic Dipole ◽  
Drug Targeting ◽  
Magnetic Force ◽  
Simple Procedure ◽  
Drug Carrier ◽  
Spherical Particles ◽  
Magnetic Drug Targeting ◽  
Magnetic Targeting ◽  
Magnetic Dipoles ◽  
Fixed Radius

Magnetic drug targeting can be used for locoregional cancer therapy, although the limitation is minuteness of the induced force. A new and simple procedure to enhance the magnetic force is changing the shape of carrier particles. It has been mathematically proved that exerting much stronger magnetic dipoles to nanowires are more possible than to spheres with the same volume. The magnetic dipole of wires having aspect quotient (ratio of length to diameter) of 3 is higher than the spheres of the same volume. Nanowires with α = 5 have magnetic dipoles 1.95 times greater than the spheres with the same volume. At a fixed radius, the magnetic dipole increases with the volume of the drug carrier. Magnetic targeting depth is an important parameter depending on the aspect quotient α of particles. Calculations show that the depth of targeting can exceed 8.5 cm if a nanowire with 15 nm radius and length larger than 150 nm is used as the drug carrier. This depth is 1.7 times more than that reported by previous authors for spherical particles with the same-volume.

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