The report is the second in a series of investigations into the diffraction of electromagnetic radiation by apertures in conducting screens. Herein...is presented a technique for obtaining the fields everywhere for plane electromagnetic radiation incident obliquely on a slotted conducting plane. The
Solution of the Bethe-Salpeter equation in the field of a plane electromagnetic wave
International Nuclear Information System (INIS)
Starostin, V.S.
1988-01-01
A solution is obtained of the Bethe--Salpeter equation for positronium in the field of linearly and circularly polarized plane electromagnetic waves at frequencies much higher than atomic. It is not assumed that the field is weak
A differentiated plane wave as an electromagnetic vortex
Hannay, J. H.; Nye, J. F.
2015-04-01
Differentiating a complex scalar plane wave with respect to its direction produces an isolated straight vortex line and has a natural extension, described in earlier papers, to the vector waves of electromagnetism—a differentiated plane wave (DPW). It epitomizes destructive interference and will be shown to have the local structure of an electromagnetic vortex. In this paper its polarization structure and Poynting vector field are compared and contrasted with that of the family of linear polynomial waves, of which it is a special member. By definition this wider family has a general linear complex vector function of position multiplying a plane wave, but the function must be such that the combination satisfies Maxwell’s equations. This forces translational invariance of the function along the wavevector direction—in other words the wave is ‘non-diffracting’. In a natural sense all possible polarizations are exhibited once only. But the DPW has a distinctive polarization structure only partly explored previously. Both classes of waves share similar Poynting vector fields, which can be ‘elliptic’ (helix-like flow lines) or ‘hyperbolic’, of a repulsive nature, unexpected for a vortex. Both classes can be considered as a limit in the superposition of three closely parallel ordinary plane waves in destructive interference, and this derivation is supplied in full here.
Parametric study of uniformly polarized stochastic electromagnetic beam and its imaging
International Nuclear Information System (INIS)
Du Xinyue; Zhao Daomu
2009-01-01
A parametric study is performed in investigating the stochastic electromagnetic beam generated by a uniformly polarized electromagnetic Gaussian Schell-model source and passing through ABCD optical systems. Through theoretical analysis, the requirement is derived that the uniformly polarized electromagnetic field can be obtained at the output plane of the imaging optical system. Furthermore, the general imaging formula of the stochastic electromagnetic beam is derived. Numerical examples are also presented to illustrate the application.
Stochastic electromagnetic plane-wave pulse with non-uniform correlation distribution
International Nuclear Information System (INIS)
Ding, Chaoliang; Cai, Yangjian; Zhang, Yongtao; Wang, Haixia; Zhao, Zhiguo; Pan, Liuzhan
2013-01-01
Stochastic electromagnetic plane-wave (SEPW) pulse with non-uniform correlation distribution is introduced. The realizability condition for such pulse is derived. It is found that the evolution properties of the intensity and the degree of polarization of an SEPW pulse with non-uniform correlation distribution in dispersive media are much different from those of an SEPW pulse with uniform correlation distribution.
Analysis on Electromagnetic Interference for Power Plane-Battery Management System (PP-BMS Enclosure
Directory of Open Access Journals (Sweden)
Yanpeng SUN
2014-11-01
Full Text Available Finite Difference Time Domain (FDTD is applied to study the characteristics of electromagnetic interference for power plane-battery management system (PP-BMS enclosure, for modeling the coupling of an incident electromagnetic pulse (EMP with a conducting wire through a BMS enclosure and aperture on it. Simulation and analysis are done by radius of the wires, incidence angles of EMP in the conditions of different polarized direction, and different annular apertures in consideration. The simulation result shows that interference of the electromagnetic coupling into the PP-BMS enclosure can be affected in different degrees by above factors. At low frequency, the larger the radius of the wire penetrated into the PP-BMS enclosure, the more interference is coupled into the BMS enclosure from electromagnetic field. Also, the electromagnetic energy coupled by penetrated wire when incident wave radiates aslant is more than the coupling energy when incident wave radiates the target vertically in the condition of vertical polarized direction of electric field, and less in the condition of horizontally polarized direction of electric field. Furthermore, in the case of the same aperture area, the coupling electromagnetic energy into the circular annular aperture is smaller than that into the rectangular and the square ones.
Coherent polarization driven by external electromagnetic fields
International Nuclear Information System (INIS)
Apostol, M.; Ganciu, M.
2010-01-01
The coherent interaction of the electromagnetic radiation with an ensemble of polarizable, identical particles with two energy levels is investigated in the presence of external electromagnetic fields. The coupled non-linear equations of motion are solved in the stationary regime and in the limit of small coupling constants. It is shown that an external electromagnetic field may induce a macroscopic occupation of both the energy levels of the particles and the corresponding photon states, governed by a long-range order of the quantum phases of the internal motion (polarization) of the particles. A lasing effect is thereby obtained, controlled by the external field. Its main characteristics are estimated for typical atomic matter and atomic nuclei. For atomic matter the effect may be considerable (for usual external fields), while for atomic nuclei the effect is extremely small (practically insignificant), due to the great disparity in the coupling constants. In the absence of the external field, the solution, which is non-analytic in the coupling constant, corresponds to a second-order phase transition (super-radiance), which was previously investigated.
Coherent scattering of electromagnetic radiation by a polarized particle system
International Nuclear Information System (INIS)
Agre, M.Ya.; Rapoport, L.P.
1996-01-01
The paper deals with the development of the theory of coherent scattering of electromagnetic waves by a polarized atom or molecular system. Peculiarities of the angular distribution and polarization peculiarities of scattered radiation are discussed
Interaction of plane gravitational and electromagnetic waves in an external gravitational field
International Nuclear Information System (INIS)
Denisov, V.I.; Eliseev, V.A.
1987-01-01
Interaction of gravitational and electromagnetic waves in an external gravitational field for two classes of metric gravitation theories is considered. As a result conditions for resonance interaction are determined, and possibility of continuous amplification of plane electromagnetic wave with plane gravitational wave is shown
International Nuclear Information System (INIS)
Kriegsmann, G.A.
1976-01-01
In this paper we apply the method of geometrical optics to study the scattering of plane electromagnetic waves off a cylindrically confined cold plasma. For simplicity, we assume two types of incident polarization. In both cases scalar second order elliptic partial differential equations describe the fields. These problems are studied in the asymptotic limit aω/c→infinity (where a is the radius of the cylinder, ω is the frequency of the incident plane wave, and c is the velocity of light in free space). We furthermore assume a quadratic plasma density. This allows us to calculate explicitly the rays, amplitudes, caustics, and other features which arise in the geometrical optics approach. The assumed density also gives rise to the interesting cutoff and resonance phenomenon. Thus the amplification of the electromagnetic fields is observed. This phenomenon may have applications in laser fusion
New material equations for electromagnetism with toroid polarizations
International Nuclear Information System (INIS)
Dubovik, V.M.; Martsenyuk, M.A.; Saha, B.
1999-09-01
With regard to the toroid contributions, a modified system of equations of electrodynamics moving continuous media has been obtained. Alternative formalisms to introduce the toroid moment contributions in the equations of electromagnetism has been worked out. The two four-potential formalism has been developed. Lorentz transformation laws for the toroid polarizations has been given. Covariant form of equations of electrodynamics of continuous media with toroid polarizations has been written. (author)
Weak-electromagnetic interference in polarized eD scattering
International Nuclear Information System (INIS)
Prescott, C.Y.
1992-09-01
Observation of parity non-conservation in deep-inelastic scattering of polarized electrons from deuterium was reported in an experiment at SLAC in 1978. The events at SLAC and elsewhere leading to the successful search for parity non-conservation in the electromagnetic processes are described
Cometary dust dynamics and polarization in electromagnetic radiation fields
Herranen, J.; Markkanen, J.; Muinonen, K.
2017-09-01
In our work, we apply a fast solution of electromagnetic scattering to determine the induced spin and movement of a dust particle in a cometary coma. The resulted aligned spinning state is then used to determine the observable polarization of the dust, and compared against the randomly averaged polarization of the same particle. We find that measurable effects arise due to the alignment. In the future, similar methods can be used to model the dynamics and in turn the polarization of the whole coma.
Pradhan, Anirudh; Singh, P. K.; Yadav, A. K.
2007-01-01
A plane-symmetric inhomogeneous cosmological model of perfect fluid distribution with electro-magnetic field is obtained. The source of the magnetic field is due to an electric current produced along the z-axis. $F_{12}$ is the non-vanishing component of electromagnetic field tensor. To get a deterministic solution, we assume the free gravitational field is Petrov type-II non-degenerate. The behaviour of the electro-magnetic field tensor together with some physical aspects of the model are al...
Electromagnetic cloaking devices for TE and TM polarizations
International Nuclear Information System (INIS)
Bilotti, Filiberto; Tricarico, Simone; Vegni, Lucio
2008-01-01
In this paper, we present the design of an electromagnetic cloaking device working for both transverse electric (TE) and transverse magnetic (TM) polarizations. The theoretical approach to cloaking used here is inspired by the one presented by Alu and Engheta (2005 Phys. Rev. E 72 016623) for TM polarization. The case of TE polarization is firstly considered and, then, an actual inclusion-based cloak for TE polarization is also designed. In such a case, the cloak is made of a mu-near-zero (MNZ) metamaterial, as the dual counterpart of the epsilon-near-zero (ENZ) material that can be used for purely dielectric objects. The operation and the robustness of the cloaking device for the TE polarization is deeply investigated through a complete set of full-wave numerical simulations. Finally, the design and an application of a cloak operating for both TE and TM polarizations employing both magnetic inclusions and the parallel plate medium already used by Silveirinha et al (Phys. Rev. E 75 036603) are presented.
Linear GPR Imaging Based on Electromagnetic Plane-Wave Spectra and Diffraction Tomography
DEFF Research Database (Denmark)
Meincke, Peter
2004-01-01
in the forward model. The two inversion schemes include an accurate electromagnetic description of the GPR antennas through their plane-wave transmitting and receiving spectra. The performance of the FTM is investigated through a numerical example involving a 2.5-dimensional configuration in which the GPR...
Polarization-independent electromagnetically induced transparency-like metasurface
Jia, Xiuli; Wang, Xiaoou
2018-01-01
A classical electromagnetically induced transparency-like (EIT-like) metasurface is numerically simulated. This metasurface is composed of two identical and orthogonal double-end semitoroidals (DESTs) metal resonators. Under the excitation of the normal incidence waves, each of the two DESTs structure exhibits electromagnetic dipole responses at different frequencies, which leads to the polarization-independent EIT-like effect. The features of the EIT-like effect are qualitatively analyzed based on the surface current and magnetic field distribution. In addition, the large index is extracted to verify the slow-light property within the transmission window. The EIT-like metasurface structure with the above-mentioned characteristics may have potential applications in some areas, such as sensing, slow light, and filtering devices.
Tripling the capacity of wireless communications using electromagnetic polarization.
Andrews, M R; Mitra, P P; deCarvalho, R
2001-01-18
Wireless communications are a fundamental part of modern information infrastructure. But wireless bandwidth is costly, prompting a close examination of the data channels available using electromagnetic waves. Classically, radio communications have relied on one channel per frequency, although it is well understood that the two polarization states of planar waves allow two distinct information channels; techniques such as 'polarization diversity' already take advantage of this. Recent work has shown that environments with scattering, such as urban areas or indoors, also possess independent spatial channels that can be used to enhance capacity greatly. In either case, the relevant signal processing techniques come under the heading of 'multiple-input/multiple-output' communications, because multiple antennae are required to access the polarization or spatial channels. Here we show that, in a scattering environment, an extra factor of three in channel capacity can be obtained, relative to the conventional limit using dual-polarized radio signals. The extra capacity arises because there are six distinguishable electric and magnetic states of polarization at a given point, rather than two as is usually assumed.
Induced polarization and electromagnetic field surveys of sedimentary uranium deposits
International Nuclear Information System (INIS)
Campbell, D.L.; Smith, B.D.
1985-01-01
Induced polarization (IP) and electromagnetic (EM) geophysical surveys were made over three areas of sedimentary uranium deposits in the western United States. The EM techniques were sometimes useful for investigating general structural settings, but not for finding uranium deposits per se. IP techniques were useful to help pinpoint zones of disseminated pyrite associated with the uranium deposits. In one case no clear differences were seen between the IP signatures of oxidized and reduced ground. Spectral (multi-frequency) IP showed no particular advantages over conventional IP for exploration applications. A sediment mineralization factor is introduced comparable to the ''metal factor'' used to detect porphyry copper mineralization. (author)
[Effect of decimeter polarized electromagnetic radiation on germinating capacity of seeds].
Polevik, N D
2013-01-01
The effect of a polarization structure of electromagnetic radiation on the germinating capacity of seeds of such weeds as Green foxtail (Setaria viridis) and Green amaranth (Amaranthus retroflexus) has been studied. Seeds have been exposed to impulse electromagnetic radiation in a frequency of 896 MHz with linear, elliptical right-handed and elliptical left-handed polarizations at different power flux density levels. It is determined that the effect of the right-handed polarized electromagnetic radiation increases and the influence of the left-handed polarized one reduces the germinating capacity of seeds compared to the effect of the linearly polarized electromagnetic radiation. It is shown that the seeds have an amplitude polarization selectivity as evinced by the major effect of the right-handed polarized radiation on seeds. An electrodynamic model as the right-handed elliptically polarized antenna with the given quantity of the ellipticity of polarization is suggested to use in description of this selectivity.
Perturbation theory for the Bethe-Salpeter equation in the field of a plane electromagnetic wave
International Nuclear Information System (INIS)
Starostin, V.S.; Litskevich, I.K.
1990-01-01
The completeness and orthogonality of the solutions of the Bethe-Salpeter equation is proven. A correct derivation of perturbation-theory equations is given. A generalization that includes the field of a plane electromagnetic wave is proposed. The rate of one-photon annihilation of positronium in this field is calculated. If the one-photon decay is allowed, the stationary states of the system are found (states of light-positronium)
FDTD modelling of induced polarization phenomena in transient electromagnetics
Commer, Michael; Petrov, Peter V.; Newman, Gregory A.
2017-04-01
The finite-difference time-domain scheme is augmented in order to treat the modelling of transient electromagnetic signals containing induced polarization effects from 3-D distributions of polarizable media. Compared to the non-dispersive problem, the discrete dispersive Maxwell system contains costly convolution operators. Key components to our solution for highly digitized model meshes are Debye decomposition and composite memory variables. We revert to the popular Cole-Cole model of dispersion to describe the frequency-dependent behaviour of electrical conductivity. Its inversely Laplace-transformed Debye decomposition results in a series of time convolutions between electric field and exponential decay functions, with the latter reflecting each Debye constituents' individual relaxation time. These function types in the discrete-time convolution allow for their substitution by memory variables, annihilating the otherwise prohibitive computing demands. Numerical examples demonstrate the efficiency and practicality of our algorithm.
Gautam, Manu; Chattanahalli Devendrachari, Mruthyunjayachari; Thimmappa, Ravikumar; Raja Kottaichamy, Alagar; Pottachola Shafi, Shahid; Gaikwad, Pramod; Makri Nimbegondi Kotresh, Harish; Ottakam Thotiyl, Musthafa
2017-03-15
Graphene oxide (GO) anisotropically conducts protons with directional dominance of in plane ionic transport (σ IP) over the through plane (σ TP). In a typical H 2 -O 2 fuel cell, since the proton conduction occurs through the plane during its generation at the fuel electrode, it is indeed inevitable to selectively accelerate GO's σ TP for advancement towards a potential fuel cell membrane. We successfully achieved ∼7 times selective amplification of GO's σ TP by tuning the polarity of the dopant molecule in its nanoporous matrix. The coexistence of strongly non-polar and polar domains in the dopant demonstrated a synergistic effect towards σ TP with the former decreasing the number of water molecules coordinated to protons by ∼3 times, diminishing the effects of electroosmotic drag exerted on ionic movements, and the latter selectively accelerating σ TP across the catalytic layers by bridging the individual GO planes via extensive host guest H-bonding interactions. When they are decoupled, the dopant with mainly non-polar or polar features only marginally enhances the σ TP, revealing that polarity factors contribute to fuel cell relevant transport properties of GO membranes only when they coexist. Fuel cell polarization and kinetic analyses revealed that these multitask dopants increased the fuel cell performance metrics of the power and current densities by ∼3 times compared to the pure GO membranes, suggesting that the functional group factors of the dopants are of utmost importance in GO-based proton exchange membrane fuel cells.
Polarization monotones of two-dimensional and three-dimensional random electromagnetic fields
Bosyk, G. M.; Bellomo, G.; Luis, A.
2018-02-01
We propose a formal resource-theoretic approach to quantify the degree of polarization of two- and three-dimensional random electromagnetic fields. This endows the space of spectral polarization matrices with the orders induced by majorization or convex mixing that naturally recover the best-known polarization measures.
Theory of Nonlinear Guided Electromagnetic Waves in a Plane Two-Layered Dielectric Waveguide
Directory of Open Access Journals (Sweden)
Valeria Yu. Kurseeva
2017-01-01
Full Text Available Propagation of transverse electric electromagnetic waves in a homogeneous plane two-layered dielectric waveguide filled with a nonlinear medium is considered. The original wave propagation problem is reduced to a nonlinear eigenvalue problem for an equation with discontinuous coefficients. The eigenvalues are propagation constants (PCs of the guided waves that the waveguide supports. The existence of PCs that do not have linear counterparts and therefore cannot be found with any perturbation method is proven. PCs without linear counterparts correspond to a novel propagation regime that arises due to the nonlinearity. Numerical results are also presented; the comparison between linear and nonlinear cases is made.
Directory of Open Access Journals (Sweden)
V. T. Erofeenko
2017-01-01
Full Text Available The main idea of the article is the development of the method for solving the boundary-value problem of penetrating the plane monochromatic electromagnetic fields through the screen made from the material with space dispersion. The problem is based on the use of the differential mathematical model of the medium with space dispersion, classical boundary conditions of continuity of the tangential components of the fields and complementary boundary conditions on the face surfaces of the screen. The article gives an analytical solution of the boundary-value problem and examines the ratio of screen performance by the reduction of the field while passing through the screen.
Energy Technology Data Exchange (ETDEWEB)
Abramov, Arnold, E-mail: qulaser@gmail.com [Kuang-Chi Institute of Advanced Technology, Shenzhen, 518057 (China); Kostikov, Alexander [Donbass State Engineering Academy, 84303, Kramatorsk, Donetsk (Ukraine)
2017-03-26
We report the effect of scattering of electromagnetic plane waves by two cylinders on whispering gallery mode (WGM) formation in a cylinder. WGM can occur because of the presence of additional cylinder scatterers at specific location, while WGMs can only form in a single cylinder for specific cylinder radius and/or wavelength values, the matching accuracy required would be much greater than that required in our model for the additional cylinders locations. Analysis of the general solution to the problem showed that the effect can be explained by the interference of waves scattered by additional cylinders and incident on the main cylinder. - Highlights: • We consider scattering of electromagnetic plane waves by two cylinders. • WGMs occur because of the presence of additional cylinder at specific location. • The accuracy for the locations is much less than required for specific values of single cylinder. • The interference of waves scattered by additional cylinders and incident on the main is responsible for the effect.
Polarization optics for out-of-plane light trajectories: GRIN lenses and optical fibers
Tentori, Diana; Trevino-Martinez, Fernando; Ayala-Diaz, Cesar; Camacho, Javier; Mendieta-Jimenez, Francisco J.
2001-08-01
The volution of the state of polarization along an out-of- plane trajectory has been widely studied for monomode optical fibers. To demonstrate the validity of our proposal we compare the results predicted by our model with experimental result obtained for helically wound optical fibers and the conoscopic patterns obtained for GRIN lenses when oblique illumination is used.
Spin polarization tuning in the graphene quantum dot by using in-plane external electric field
International Nuclear Information System (INIS)
Modarresi, M.; Roknabadi, M.R.; Shahtahmasebi, N.
2014-01-01
Electronic, magnetic and transport properties of a nano-graphene dot have been studied by using the DFT and tight binding methods. In the tight binding calculations, the interaction between electrons is modeled using the Hubbard Hamiltonian. By comparison between the eigen-values and density of states in the tight binding and DFT models, we tabulate a set of tight-binding parameters to describe graphene quantum dots for future works. The effects of a single vacancy and an in-plane external electric field on the spin-dependent transport of graphene quantum dot have been investigated. Transport through GQD between two GNR is studied by using Green's function formalism. Our results confirm an intrinsic spin-dependent current and relatively large spin polarization through the GQD in the presence of a single vacancy and zigzag edge. It is also shown that an in-plane external electric field controls the spin-polarization in graphene quantum dot. - Graphical abstract: We study the spin polarization in the presence of an external electric field. Highlights: • A tight binding study of transport through GNR/GQD/GNR is presented. • Our results show a relatively large spin polarization in the current–voltage curve. • Spin polarization is controlled by using an in-plane external electric field
Bejan, D.; Stan, C.; Niculescu, E. C.
2018-01-01
We theoretically investigated the effects of the impurity position, in-plane electric field, intensity and polarization of the probe and control lasers on the electromagnetically induced transparency (EIT) in GaAs/GaAlAs disc shaped quantum ring. Our study reveals that, depending on the impurity position, the quantum system presents two specific configurations for the EIT occurrence even in the absence of the external electric field, i.e. ladder-configuration or V-configuration, and changes the configuration from ladder to V for specific electric field values. The polarization of the probe and control lasers plays a crucial role in obtaining a good transparency. The electric field controls the red-shift (blue-shift) of the transparency window and modifies its width. The system exhibits birefringence for the probe light in a limited interval of electric field values.
Lock, James A.
2017-11-01
The formulas of ray theory and Airy theory for scattering of an electromagnetic plane wave by a radially inhomogeneous sphere are obtained from the generalization of exact Lorenz-Mie wave scattering theory using the WKB approximation to determine the radial portion of the partial wave scalar radiation potential, carrying out a Debye series expansion of it, approximating the sum over partial waves by an integral over an associated impact parameter, and approximately evaluating the integral using either the method of stationary phase or mapping it into one of the phase integrals that describe optical caustics. Various features of the results are commented on, and the procedure is extended to the merging of two rainbows in a given Debye series channel in the context of the longitudinal cusp caustic.
Reflection and Transmission of Plane Electromagnetic Waves by a Geologic Layer.
Energy Technology Data Exchange (ETDEWEB)
Aldridge, David F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2017-04-01
Electric field and magnetic field reflection and transmission responses generated by a plane wave normally incident onto a finite - thickness geologic layer are mathematically derived and numerically evaluated. A thin layer with enhanced electric current conductivity and/or magnetic permeability is a reasonable geophysical representation of a hydraulic fracture inject ed with a high - contrast proppant pack. Both theory and numerics indicate that backward - and forward - scattered electromagnetic wavefields are potentially observable in a field experiment, despite the extreme thinness of a fracture compared to a typical low - frequency electromagnetic wavelength. The First Born Approximation (FBA) representation of layer scattering, significant for inversion studies, is shown to be accurate for a thin layer with mild medium parameter (i.e., conductivity, permeability, and per mittivity) contrasts with the surrounding homogeneous wholespace. However, FBA scattering theory breaks down for thick layers and strong parameter contrasts. ACKNOWLEDGEMENTS Sandia National Laboratories is a multi - mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. This research is conducted under the auspices of CRADA (Cooperative Research and Development Agreement) SC11/01780.00 between Carbo Ceramics Inc. and Sandia National Laboratories. The author acknowledges former Carbo R&D Vic e - President Mr. Chad Cannan and former SNL Geophysics Department manage r Ms. Amy Halloran for their interest i n and support of this work. Technical discussions with Project Manager and Principal Investigator Dr. Chester J. Weiss of the SNL Geophysics Department greatly benefited this work. Dr. Lewis C. Bartel, formerly with S NL and presently a consultant to Carbo Ceramics, provided many useful and intuitive insights, and
Passive polarization agile antenna based on the electromagnetically induced transparency-like effect
International Nuclear Information System (INIS)
Zhu, Lei; Meng, Fan-Yi; Wu, Qun; Chen, Wan; Fu, Jia-Hui; Dong, Liang
2014-01-01
We propose a design method for a passive polarization agile antenna based on the electromagnetically induced transparency-like (EIT-like) effect. Benefiting from strong dispersion properties governed by EIT-like effects, the proposed structure can endow electromagnetic waves transmitted through it with quite different polarization states at very close frequencies. The experimental measurement was conducted to demonstrate agile polarization controls by placing a designed EIT-like waveplate in front of a standard microwave horn antenna. Results show that the polarization state of radiated waves by the horn antenna with a waveplate can be easily transformed among linear, circular and elliptical polarizations through fine-tuning the operating frequency, which is extremely important for certain special applications, e.g. electronic countermeasures. Our scheme could also be utilized at higher operating frequencies by the simply scaling principle. (paper)
Passive polarization agile antenna based on the electromagnetically induced transparency-like effect
Zhu, Lei; Meng, Fan-Yi; Wu, Qun; Dong, Liang; Chen, Wan; Fu, Jia-Hui
2014-10-01
We propose a design method for a passive polarization agile antenna based on the electromagnetically induced transparency-like (EIT-like) effect. Benefiting from strong dispersion properties governed by EIT-like effects, the proposed structure can endow electromagnetic waves transmitted through it with quite different polarization states at very close frequencies. The experimental measurement was conducted to demonstrate agile polarization controls by placing a designed EIT-like waveplate in front of a standard microwave horn antenna. Results show that the polarization state of radiated waves by the horn antenna with a waveplate can be easily transformed among linear, circular and elliptical polarizations through fine-tuning the operating frequency, which is extremely important for certain special applications, e.g. electronic countermeasures. Our scheme could also be utilized at higher operating frequencies by the simply scaling principle.
Li, Hai-ming; Xue, Feng
2017-09-01
In this manuscript, tailoring polarization of analogy of electromagnetically induced transparency (EIT-like) based on non-centrosymmetric metasurfaces has been numerically and experimentally demonstrated. The EIT-like metamaterial is composed of a rectangle ring and two cut wires. The rectangle ring and the cut wire are chosen as the bright mode and the quasi-dark mode, respectively. Under the incident electromagnetic wave excitation, a polarization insensitive EIT-like transmission window can be observed at specific polarization angles. Within the transmission window, the phase steeply changes, which leads to the large group index. Tailoring polarization of EIT-like metamaterial with large group index at specific polarization angles may have potential application in slow light devices.
Unpolarized nucleon structure studies utilizing polarized electromagnetic probes
International Nuclear Information System (INIS)
Arrington, J.
2009-01-01
By the mid-1980s, measurements of the nucleon form factors had reached a stage where only slow, incremental progress was possible using unpolarized electron scattering. The development of high quality polarized beams, polarized targets, and recoil polarimeters led to a renaissance in the experimental program. I provide an overview of the changes in the field in the last ten years, which were driven by the dramatically improved data made possible by a new family of tools to measure polarization observables
International Nuclear Information System (INIS)
Chatterjee, I.; Gandhi, O.P.; Hagmann, M.J.; Riazi, A.
1980-01-01
The exposure of humans to electromagnetic near fields has not been sufficiently emphasized by researcher. We have used the plane-wave-spectrum approach to evaluate the electromagnetic field and determine the energy deposited in a lossy, homogeneous, semi-infinite slab placed in the near field of a source leaking radiation. Values of the fields and absorbed energy in the target are obtained by vector summation of the contributions of all the plane waves into which the prescribed field is decomposed. Use of a fast Fourier transform algorithm contributes to the high efficiency of the computations. The numerical results show that, for field distributions that are nearly constant over a physical extent of at least a free-space wavelength, the energy coupled into the target is approximately equal to the resulting from plane-wave exposed
Electromagnetic spatial coherence wavelets
International Nuclear Information System (INIS)
Castaneda, R.; Garcia-Sucerquia, J.
2005-10-01
The recently introduced concept of spatial coherence wavelets is generalized for describing the propagation of electromagnetic fields in the free space. For this aim, the spatial coherence wavelet tensor is introduced as an elementary amount, in terms of which the formerly known quantities for this domain can be expressed. It allows analyzing the relationship between the spatial coherence properties and the polarization state of the electromagnetic wave. This approach is completely consistent with the recently introduced unified theory of coherence and polarization for random electromagnetic beams, but it provides a further insight about the causal relationship between the polarization states at different planes along the propagation path. (author)
Directory of Open Access Journals (Sweden)
Kittima Lertsakwimarn
2013-01-01
Full Text Available This paper presents a low-profile printed antenna with double U-shaped arms radiating circular polarization for the UHF RFID readers. The proposed antenna consists of double U-shaped strip structures and a capacitive feeding line to generate circular polarization. A part of the U-shaped arms is bent by 90° to direct the main beam parallel to the ground plane. From the results, -10 dB |S11| and 3 dB axial ratio of the antenna cover a typical UHF RFID band from 920 MHz to 925 MHz. The bidirectional beam is obtained with the maximum gain of 1.8 dBic in the parallel direction to the ground plane at the 925 MHz. The overall size of the proposed antenna including ground plane is 107 mm × 57 mm × 12.8 mm (0.33λ0 × 0.17λ0 × 0.04λ0.
An analysis of the electromagnetic field in multi-polar linear induction system
International Nuclear Information System (INIS)
Chervenkova, Todorka; Chervenkov, Atanas
2002-01-01
In this paper a new method for determination of the electromagnetic field vectors in a multi-polar linear induction system (LIS) is described. The analysis of the electromagnetic field has been done by four dimensional electromagnetic potentials in conjunction with theory of the magnetic loops . The electromagnetic field vectors are determined in the Minkovski's space as elements of the Maxwell's tensor. The results obtained are compared with those got from the analysis made by the finite elements method (FEM).With the method represented in this paper one can determine the electromagnetic field vectors in the multi-polar linear induction system using four-dimensional potential. A priority of this method is the obtaining of analytical results for the electromagnetic field vectors. These results are also valid for linear media. The dependencies are valid also at high speeds of movement. The results of the investigated linear induction system are comparable to those got by the finite elements method. The investigations may be continued in the determination of other characteristics such as drag force, levitation force, etc. The method proposed in this paper for an analysis of linear induction system can be used for optimization calculations. (Author)
Multiphoton ionization of the hydrogen atom by a circularly polarized electromagnetic field
International Nuclear Information System (INIS)
Prepelitsa, O.B.
1999-01-01
This paper examines the multiphoton ionization of the ground state of the hydrogen atom in the field of a circularly polarized intense electromagnetic wave. To describe the states of photoelectrons, quasiclassical wave functions are introduced that partially allow for the effect of an intense electromagnetic wave and that of the Coulomb potential. Expressions are derived for the angular and energy distributions of photoelectrons with energies much lower than the ionization potential of an unperturbed atom. It is found that, due to allowance for the Coulomb potential in the wave function of the final electron states, the transition probability near the ionization threshold tends to a finite value. In addition, the well-known selection rules for multiphoton transitions in a circularly polarized electromagnetic field are derived in a natural way. Finally, the results are compared with those obtained in the Keldysh-Faisal-Reiss approximation
The polarization evolution of electromagnetic waves as a diagnostic method for a motional plasma
Shahrokhi, Alireza; Mehdian, Hassan; Hajisharifi, Kamal; Hasanbeigi, Ali
2017-12-01
The polarization evolution of electromagnetic (EM) radiation propagating through an electron beam-ion channel system is studied in the presence of self-magnetic field. Solving the fluid-Maxwell equations to obtain the medium dielectric tensor, the Stokes vector-Mueller matrix approach is employed to determine the polarization of the launched EM wave at any point in the propagation direction, applying the space-dependent Mueller matrix on the initial polarization vector of the wave at the plasma-vacuum interface. Results show that the polarization evolution of the wave is periodic in space along the beam axis with the specified polarization wavelength. Using the obtained results, a novel diagnostic method based on the polarization evolution of the EM waves is proposed to evaluate the electron beam density and velocity. Moreover, to use the mentioned plasma system as a polarizer, the fraction of the output radiation power transmitted through a motional plasma crossed with the input polarization is calculated. The results of the present investigation will greatly contribute to design a new EM amplifier with fixed polarization or EM polarizer, as well as a new diagnostic approach for the electron beam system where the polarimetric method is employed.
Polarization-dependent electromagnetic responses in an A-shape metasurface.
Zhang, Ning; Xu, Quan; Li, Shaoxian; Ouyang, Chunmei; Zhang, Xueqian; Li, Yanfeng; Gu, Jianqiang; Tian, Zhen; Han, Jiaguang; Zhang, Weili
2017-08-21
We numerically and experimentally demonstrate polarization-dependent terahertz responses in a proposed metasurface of A-shape resonators. With the horizontal polarization incidence, the observed transmission window is formed by two resonance dips, corresponding to the inductive-capacitive resonance at the lower frequency and the high-order antisymmetric resonance at a higher frequency, respectively. When the incident wave is perpendicularly polarized, the transmission window arises from the plasmon-induced transparency spectral response. The origin of the polarization-sensitive resonance properties is revealed by mapping the electric field and terahertz-induced surface current in the proposed metamaterials. Moreover, the influence of the geometry of the A-shape microstructures on the transmission spectra is analyzed. These polarization-dependent metamaterials may provide more degrees of freedom in tuning the electromagnetic responses, thus offering a path toward robust metamaterials design.
Lee, Adrian
We propose to develop planar-antenna-coupled superconducting bolometer arrays for observations at sub-millimeter to millimeter wavelengths. Our pixel architecture features a dual-polarization, log-periodic antenna with a 5:1 bandwidth ratio, followed by a filter bank that divides the total bandwidth into several broad photometric bands. We propose to develop an hierarchical phased array of our basic pixel type that gives optimal mapping speed (sensitivity) over a much broader range of frequencies. The advantage of this combination of an intrinsically broadband pixel with hierarchical phase arraying include a combination of greatly reduced focal-plane mass, higher array sensitivity, and a larger number of spectral bands compared to focal-plane designs using conventional single-color pixels. These advantages have the potential to greatly reduce cost and/or increase performance of NASA missions in the sub-millimeter to millimeter bands. For CMB polarization, a wide frequency range of about 30 to 400 GHz is required to subtract galactic foregrounds. As an example, the multichroic architecture we propose could reduce the focal plane mass of the EPIC-IM CMB polarization mission study concept by a factor of 4, with great savings in required cryocooler performance and therefore cost. We have demonstrated the lens-coupled antenna concept in the POLARBEAR groundbased CMB polarization experiment which is now operating in Chile. That experiment uses a single-band planar antenna that gives excellent beam properties and optical efficiency. POLARBEAR recently succeeded in detecting gravitational lensing B-modes in the CMB polarization. In the laboratory, we have measured two octaves of total bandwidth in the log-periodic sinuous antenna. We have built filter banks of 2, 3, and 7 bands with 4, 6, and 14 bolometers per pixel for two linear polarizations. Pixels of this type are slated to be deployed on the ground in POLARBEAR and SPT-3G and proposed to be used on a balloon by EBEX
Zhao, G. Q.; Feng, H. Q.; Wu, D. J.; Huang, J.
2018-03-01
Recent studies have revealed that there are a large number of low frequency electromagnetic cyclotron waves (ECWs) occurring in and around magnetic clouds (MCs) that are common magnetic structures in interplanetary space. Using magnetic field data from the STEREO spacecraft, this paper investigates polarization properties of ECWs associated with 120 MCs. Results show that the ECWs are highly transverse, strongly polarized waves with large ellipticities. Specifically, almost all of the waves take place with the ratios of transverse power to total power higher than 0.94, polarization degrees greater than 0.85, and ellipticities larger than 0.5. The mean values of these quantities can be up to 0.99, 0.96, 0.85, respectively. In particular, there is a tendency of ellipticities decreasing with respect to the wave normal angles for ECWs with left handed polarization. The decreasing tendency is consistent with the recent theory and simulation results.
Energy Technology Data Exchange (ETDEWEB)
Colavita, E. [Colegio de Ciencia y Tecnología, Universidad Autónoma de la Ciudad de México, México, D.F., 09790 (Mexico); Hacyan, S., E-mail: hacyan@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, A. P. 20-364, México D. F., 01000 (Mexico)
2014-03-15
We analyze the solutions of the Klein–Gordon and Dirac equations describing a charged particle in an electromagnetic plane wave combined with a magnetic field parallel to the direction of propagation of the wave. It is shown that the Klein–Gordon equation admits coherent states as solutions, while the corresponding solutions of the Dirac equation are superpositions of coherent and displaced-number states. Particular attention is paid to the resonant case in which the motion of the particle is unbounded. -- Highlights: •We study a relativistic electron in a particular electromagnetic field configuration. •New exact solutions of the Klein–Gordon and Dirac equations are obtained. •Coherent and displaced number states can describe a relativistic particle.
Pan, Liuzhan; Sun, Mengle; Ding, Chaoliang; Zhao, Zhiguo; Lü, Baida
2009-04-27
Analytical formulas for the cross-spectral density matrix of stochastic electromagnetic Gaussian Schell-model (EGSM) beams passing through an astigmatic optical system are derived. We show both analytically and by numerical examples the effects of astigmatism on spectra, coherence and polarization of stochastic electromagnetic EGSM beams propagating through an astigmatic lens. A comparison with the aberration-free case is made, and shows that the astigmatism has significant effect on the spectra, coherence and polarization.
Guidoboni, G.; Stephenson, E. J.; Wrońska, A.; Bagdasarian, Z.; Bsaisou, J.; Chekmenev, S.; Ciullo, G.; Dymov, S.; Eversmann, D.; Gaisser, M.; Gebel, R.; Hejny, V.; Hempelmann, N.; Hinder, F.; Kacharava, A.; Keshelashvili, I.; Kulessa, P.; Lenisa, P.; Lehrach, A.; Lorentz, B.; Maanen, P.; Maier, R.; Mchedlishvili, D.; Mey, S.; Nass, A.; Pesce, A.; Orlov, Y.; Pretz, J.; Prasuhn, D.; Rathmann, F.; Rosenthal, M.; Saleev, A.; Semertzidis, Y. K.; Senichev, Y.; Shmakova, V.; Stockhorst, H.; Ströher, H.; Talman, R.; Thörngren Engblom, P.; Trinkel, F.; Valdau, Yu.; Weidemann, C.; Wüstner, P.; Żurek, M.; Zyuzin, D.; JEDI Collaboration
2018-02-01
In this paper, we demonstrate the connection between a magnetic storage ring with additional sextupole fields set so that the x and y chromaticities vanish and the maximizing of the lifetime of in-plane polarization (IPP) for a 0.97 -GeV /c deuteron beam. The IPP magnitude was measured by continuously monitoring the down-up scattering asymmetry (sensitive to sideways polarization) in an in-beam, carbon-target polarimeter and unfolding the precession of the IPP due to the magnetic anomaly of the deuteron. The optimum operating conditions for a long IPP lifetime were made by scanning the field of the storage ring sextupole magnet families while observing the rate of IPP loss during storage of the beam. The beam was bunched and electron cooled. The IPP losses appear to arise from the change of the orbit circumference, and consequently the particle speed and spin tune, due to the transverse betatron oscillations of individual particles in the beam. The effects of these changes are canceled by an appropriate sextupole field setting.
International Nuclear Information System (INIS)
Kawai, Hiroki; Nagaoka, Tomoaki; Watanabe, Soichi; Saito, Kazuyuki; Takahashi, Masaharu; Ito, Koichi
2010-01-01
This paper presents calculated specific absorption rate (SAR) dosimetry in 4 and 8 week Japanese pregnant-woman models exposed to plane waves over the frequency range of 10 MHz-1.5 GHz. Two types of 2 mm spatial-resolution pregnant-woman models comprised a woman model, which is similar to the average-sized Japanese adult female in height and weight, with a cubic (4 week) embryo or spheroidal (8 week) one. The averaged SAR in the embryos exposed to vertically and horizontally polarized plane waves at four kinds of propagation directions are calculated from 10 MHz to 1.5 GHz. The results indicate that the maximum average SAR in the embryos exposed to plane waves is lower than 0.08 W kg -1 when the incident power density is at the reference level of ICNIRP guideline for general public environment. (note)
International Nuclear Information System (INIS)
Dragila, R.; Vukovic, S.
1988-01-01
The properties of surfave waves that are associated with a boundary between a rare plasma and a dense magnetoactive plasma and that propagate along a dc magnetic field are investigated. It is shown that the presence of the magnetic field introduces symmetry in terms of the polarization of the incident electromagnetic wave that excites the surface waves. A surface wave excited by an incident p-polarized (s-polarized) electromagnetic wave leaks in the form of an s-polarized (p-polarized) electromagnetic wave. The rate of rotation of polarization is independent of the polarization of the incident wave. Because a surface wave can leak in the form of an s-polarized electromagnetic wave, it can also be pumped by such a wave, and conditions were found for excitation of a surface wave by an s-polarized incident electromagnetic wave
Peng, Yu-Xiang; Wang, Kai-Jun; He, Meng-Dong; Luo, Jian-Hua; Zhang, Xin-Min; Li, Jian-Bo; Tan, Shi-Hua; Liu, Jian-Qiang; Hu, Wei-Da; Chen, Xiaoshuang
2018-04-01
In this paper, we demonstrate the effect of polarization conversion in a plasmonic metasurface structure, in which each unit cell consists of a metal bar and four metal split-ring resonators (SRRs). Such effect is attributed to the fact that the dark plasmon mode of SRRs (bar), which radiates cross-polarized component, is induced by the bright plasmon mode of bar (SRRs) due to the electromagnetic near-field coupling between bar and SRRs. We find that there are two ways to achieve a large cross-polarized component in our proposed metasurface structure. The first way is realized when the dark plasmon mode of bar (SRRs) is in resonance, while at this time the bright plasmon mode of SRRs (bar) is not at resonant state. The second way is realized when the bright plasmon mode of SRRs (bar) is resonantly excited, while the dark plasmon mode of bar (SRRs) is at nonresonant state. It is also found that the linearly polarized light can be rotated by 56.50 after propagation through the metasurface structure. Furthermore, our proposed metasurface structure exhibits an asymmetric transmission for circularly polarized light. Our findings take a further step in developing integrated metasurface-based photonics devices for polarization manipulation and modulation.
International Nuclear Information System (INIS)
Chou, Yen; Li, Hsiang-Wei; Yin, Yu-Feng; Wang, Yu-Ting; Lin, Yen-Chen; Wu, Yuh-Renn; Huang, Jian Jang; Lin, Da-Wei; Kuo, Hao-Chung
2014-01-01
Fabricating photonic crystals (PhCs) on GaN based non-polar light emitting diodes (LEDs) is an effective way to increase light extraction and meanwhile to preserve or improve polarization ratio. In this work, a-plane GaN LEDs with two-dimensional PhCs were demonstrated. With the E // m polarized modes (which mean the optical polarization with the electric field parallel to m-axis) as the target of diffraction, we matched E//m modes to the photonic bands and aligned E//c modes to fall within the photonic band gap. The results show stronger E//m but weaker E//c mode diffractions on both c- and m-axes. At the vertical direction, the polarization ratio is enhanced from 45.8% for the planar device to 52.3% for the LEDs with PhCs
Stephen, Lincy; Yogesh, N.; Subramanian, V.
2018-01-01
The giant optical activity of chiral metamaterials (CMMs) holds great potential for tailoring the polarization state of an electromagnetic (EM) wave. In controlling the polarization state, the aspect of asymmetric transmission (AT), where a medium allows the EM radiation to pass through in one direction while restricting it in the opposite direction, adds additional degrees of freedom such as one-way channelling functionality. In this work, a CMM formed by a pair of mutually twisted slanted complementary metal strips is realized for broadband AT accompanied with cross-polarization (CP) conversion for linearly polarized EM waves. Numerically, the proposed ultra-thin (˜λ/42) CMM shows broadband AT from 8.58 GHz to 9.73 GHz (bandwidth of 1.15 GHz) accompanied with CP transmission magnitude greater than 0.9. The transmission and reflection spectra reveal the origin of the asymmetric transmission as the direction sensitive cross polarization conversion and anisotropic electric coupling occurring in the structure which is then elaborated with the surface current analysis and electric field distribution within the structure. An experiment is carried out to verify the broadband AT based CP conversion of the proposed CMM at microwave frequencies, and a reliable agreement between numerical and experimental results is obtained. Being ultra-thin, the reported broadband AT based CP conversion of the proposed CMM is useful for controlling radiation patterns in non-reciprocal EM devices and communication networks.
Sun, Yuan; Liu, Chang; Chen, Ping-Xing; Liu, Liang
2018-02-01
People have been paying attention to the role of atoms' complex internal level structures in the research of electromagnetically induced transparency (EIT) for a long time, where the various degenerate Zeeman levels usually generate complex linkage patterns for the atomic transitions. It turns out, with special choices of the atomic states and the atomic transitions' linkage structure, clear signatures of quantum interference induced by the probe and coupling light's polarizations can emerge from a typical EIT phenomena. We propose to study a four-state system with double-V linkage pattern for the transitions and analyze the polarization-induced interference under the EIT condition. We show that such interference arises naturally under mild conditions on the optical field and atom manipulation techniques. Moreover, we construct a variation form of double-M linkage pattern where the polarization-induced interference enables polarization-dependent cross modulation between incident weak lights that can be effective even at the few-photon level. The theme is to gain more insight into the essential question: how can we build a nontrivial optical medium where incident lights experience polarization-dependent nonlinear optical interactions, valid for a wide range of incidence intensities down to the few-photon level?
International Nuclear Information System (INIS)
Maraghechi, B.; Willett, J.e.
1979-01-01
The stimulated Raman backscattering of an intense electromagnetic wave propagating in the extraordinary mode along a uniform, static magnetic field is considered. The dispersion relation for a homogeneous magnetized plasma in the presence of the circularly polarized pump waves is developed in the cold-plasma approximation with the pump frequency above the plasma frequency. Formulas are derived for the threshold νsub(OT) of the parametric instability and for the growth rate γ of the backscattered extraordinary wave and Langmuir wave. The effects of the magnetic field parallel to the direction of propagation on νsub(0T) and γ are studied numerically. (author)
Tang, Miaomiao; Zhao, Daomu
2014-12-01
Analytical formulas are derived, for the cross spectral density matrix of electromagnetic nonuniformly correlated (EMUNC) beams, with astigmatic aberration propagating through oceanic turbulence. We investigate the effects of astigmatism on the spectral density, and the spectral degree of polarization, in great detail. It can be seen that, unlike for an aberration-free case, the lateral shifted intensity maximum (of an astigmatic EMUNC beam) does not return back to the on-axis position, after propagating at sufficiently large distances in the turbulence. Furthermore, in the far-zone, the deviation of its maximum value (from the optical axis) gradually increases, in accordance with growing propagation distance.
Vector magnetometry based on electromagnetically induced transparency in linearly polarized light
International Nuclear Information System (INIS)
Yudin, V. I.; Taichenachev, A. V.; Dudin, Y. O.; Velichansky, V. L.; Zibrov, A. S.; Zibrov, S. A.
2010-01-01
We develop a generalized principle of electromagnetically induced transparency (EIT) vector magnetometry based on high-contrast EIT resonances and the symmetry of atom-light interaction in the linearly polarized bichromatic fields. Operation of such vector magnetometer on the D 1 line of 87 Rb has been demonstrated. The proposed compass-magnetometer has an increased immunity to shifts produced by quadratic Zeeman and ac-Stark effects, as well as by atom-buffer gas and atom-atom collisions. In our proof-of-principle experiment the detected angular sensitivity to magnetic field orientation is 10 -3 deg/Hz 1/2 , which is limited by laser intensity fluctuations, light polarization quality, and magnitude of the magnetic field.
Energy Technology Data Exchange (ETDEWEB)
Tabares, G.; Hierro, A., E-mail: adrian.hierro@upm.es; Lopez-Ponce, M.; Muñoz, E. [ISOM and Dpto. Ingeniería Electrónica, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Vinter, B.; Chauveau, J.-M. [CRHEA-CNRS, Av. B. Gregory, 06560 Valbonne (France); University of Nice Sophia Antipolis, Parc Valrose, 06102 Nice cedex 2 (France)
2015-02-09
Homoepitaxial ZnO/(Zn,Mg)O multiple quantum wells (MQWs) grown with m- and r-plane orientations are used to demonstrate Schottky photodiodes sensitive to the polarization state of light. In both orientations, the spectral photoresponse of the MQW photodiodes shows a sharp excitonic absorption edge at 3.48 eV with a very low Urbach tail, allowing the observation of the absorption from the A, B and C excitonic transitions. The absorption edge energy is shifted by ∼30 and ∼15 meV for the m- and r-plane MQW photodiodes, respectively, in full agreement with the calculated polarization of the A, B, and C excitonic transitions. The best figures of merit are obtained for the m-plane photodiodes, which present a quantum efficiency of ∼11%, and a specific detectivity D* of ∼6.4 × 10{sup 10} cm Hz{sup 1/2}/W. In these photodiodes, the absorption polarization sensitivity contrast between the two orthogonal in-plane axes yields a maximum value of (R{sub ⊥}/R{sub ||}){sub max} ∼ 9.9 with a narrow bandwidth of ∼33 meV.
Ion sense of polarization of the electromagnetic wave field in the electron whistler frequency band
Directory of Open Access Journals (Sweden)
B. Lundin
Full Text Available It is shown that the left-hand (or ion-type sense of polarization can appear in the field interference pattern of two plane electron whistler waves. Moreover, it is demonstrated that the ion-type polarized wave electric fields can be accompanied by the presence at the same observation point of electron-type polarized wave magnetic fields. The registration of ion-type polarized fields with frequencies between the highest ion gyrofrequency and the electron gyrofrequency in a cold, overdense plasma is a sufficient indication for the existence of an interference wave pattern, which can typically occur near artificial or natural reflecting magnetospheric plasma regions, inside waveguides (as in helicon discharges, for example, in fields resonantly emitted by beams of charged particles or, in principle, in some self-sustained, nonlinear wave field structures. A comparison with the conventional spectral matrix data processing approach is also presented in order to facilitate the calculations of the analyzed polarization parameters.
Key words. Ionosphere (wave propagation Radio science (waves in plasma Space plasma physics (general or miscellaneous
Ion sense of polarization of the electromagnetic wave field in the electron whistler frequency band
Directory of Open Access Journals (Sweden)
B. Lundin
2002-08-01
Full Text Available It is shown that the left-hand (or ion-type sense of polarization can appear in the field interference pattern of two plane electron whistler waves. Moreover, it is demonstrated that the ion-type polarized wave electric fields can be accompanied by the presence at the same observation point of electron-type polarized wave magnetic fields. The registration of ion-type polarized fields with frequencies between the highest ion gyrofrequency and the electron gyrofrequency in a cold, overdense plasma is a sufficient indication for the existence of an interference wave pattern, which can typically occur near artificial or natural reflecting magnetospheric plasma regions, inside waveguides (as in helicon discharges, for example, in fields resonantly emitted by beams of charged particles or, in principle, in some self-sustained, nonlinear wave field structures. A comparison with the conventional spectral matrix data processing approach is also presented in order to facilitate the calculations of the analyzed polarization parameters.Key words. Ionosphere (wave propagation Radio science (waves in plasma Space plasma physics (general or miscellaneous
3-D Forward modeling of Induced Polarization Effects of Transient Electromagnetic Method
Wu, Y.; Ji, Y.; Guan, S.; Li, D.; Wang, A.
2017-12-01
In transient electromagnetic (TEM) detection, Induced polarization (IP) effects are so important that they cannot be ignored. The authors simulate the three-dimensional (3-D) induced polarization effects in time-domain directly by applying the finite-difference time-domain method (FDTD) based on Cole-Cole model. Due to the frequency dispersion characteristics of the electrical conductivity, the computations of convolution in the generalized Ohm's law of fractional order system makes the forward modeling particularly complicated. Firstly, we propose a method to approximate the fractional order function of Cole-Cole model using a lower order rational transfer function based on error minimum theory in the frequency domain. In this section, two auxiliary variables are introduced to transform nonlinear least square fitting problem of the fractional order system into a linear programming problem, thus avoiding having to solve a system of equations and nonlinear problems. Secondly, the time-domain expression of Cole-Cole model is obtained by using Inverse Laplace transform. Then, for the calculation of Ohm's law, we propose an e-index auxiliary equation of conductivity to transform the convolution to non-convolution integral; in this section, the trapezoid rule is applied to compute the integral. We then substitute the recursion equation into Maxwell's equations to derive the iterative equations of electromagnetic field using the FDTD method. Finally, we finish the stimulation of 3-D model and evaluate polarization parameters. The results are compared with those obtained from the digital filtering solution of the analytical equation in the homogeneous half space, as well as with the 3-D model results from the auxiliary ordinary differential equation method (ADE). Good agreements are obtained across the three methods. In terms of the 3-D model, the proposed method has higher efficiency and lower memory requirements as execution times and memory usage were reduced by 20
International Nuclear Information System (INIS)
Da Silva e Silva, Valdelírio; Régis, Cícero; Howard, Allen Q Jr
2014-01-01
This paper analyses the details of a procedure for the numerical integration of Hankel transforms in the calculation of the electromagnetic fields generated by a large horizontal loop over a 1D earth. The method performs the integration by deforming the integration path into the complex plane and applying Cauchy's theorem on a modified version of the integrand. The modification is the replacement of the Bessel functions J 0 and J 1 by the Hankel functions H 0 (1) and H 1 (1) respectively. The integration in the complex plane takes advantage of the exponentially decaying behaviour of the Hankel functions, allowing calculation on very small segments, instead of the infinite line of the original improper integrals. A crucial point in this problem is the location of the poles. The companion paper shows two methods to estimate the pole locations. We have used this method to calculate the fields of very large loops. Our results show that this method allows the estimation of the integrals with fewer evaluations of the integrand functions than other methods. (paper)
Rothwell, Edward J
2009-01-01
Introductory concepts Notation, conventions, and symbology The field concept of electromagneticsThe sources of the electromagnetic field Problems Maxwell's theory of electromagnetism The postulate Maxwell's equations in moving frames The Maxwell-Boffi equations Large-scale form of Maxwell's equationsThe nature of the four field quantities Maxwell's equations with magnetic sources Boundary (jump) conditions Fundamental theorems The wave nature of the electromagnetic field ProblemsThe static electromagnetic field Static fields and steady currents ElectrostaticsMagnetostatics Static field theorem
Inclusive π0 Production in Polarized pp Collisions using the STAR Endcap Electromagnetic Calorimeter
International Nuclear Information System (INIS)
Webb, Jason C.
2007-01-01
The two-spin helicity asymmetry for inclusive π0 production in polarized pp collisions probes the gluon's contribution to the spin of the proton with sensitivity comparable to that attainable with full jet reconstruction. Measurements of A LL (π0) at larger rapidity provide information about a different set of partonic subprocesses and are subject to different theoretical and experimental uncertainties than midrapidity jet measurements, providing an important cross-check. The STAR Endcap Electromagnetic calorimeter provides the capability to reconstruct high-pT π0 decays in the range 1 < η < 2 with full azimuthal coverage using a fine-grained scintillating-strip Shower-Maximum detector. Data with longitudinally polarized beams were accumulated in 2005 (sampled luminosity 3 pb-1 with beam polarizations ≅ 45 - 50%), and in 2006 (L ≅ 6pb-1, P-bar ≅ 60%) after the installation of additional shielding to reduce backgrounds. We present preliminary results from the 2005 data, and discuss the current status of the 2006 analysis
Photon polarization in Compton scattering: pulse shape effects
International Nuclear Information System (INIS)
Boca, M; Stoica, C; Dumitriu, A; Florescu, V
2015-01-01
We study in the framework of quantum electrodynamics the scattering of a plane wave electromagnetic field on free electrons in the low intensity limit. We derive analytic formulas describing the polarization properties of the emitted photons. We discuss and illustrate with a numerical example the effects of the electromagnetic pulse duration on their polarization
Coffey, Aaron M; Shchepin, Roman V; Feng, Bibo; Colon, Raul D; Wilkens, Ken; Waddell, Kevin W; Chekmenev, Eduard Y
2017-11-01
Applications of parahydrogen induced polarization (PHIP) often warrant conversion of the chemically-synthesized singlet-state spin order into net heteronuclear magnetization. In order to obtain optimal yields from the overall hyperpolarization process, catalytic hydrogenation must be tightly synchronized to subsequent radiofrequency (RF) transformations of spin order. Commercial NMR consoles are designed to synchronize applied waves on multiple channels and consequently are well-suited as controllers for these types of hyperpolarization experiments that require tight coordination of RF and non-RF events. Described here is a PHIP instrument interfaced to a portable NMR console operating with a static field electromagnet in the milliTesla regime. In addition to providing comprehensive control over chemistry and RF events, this setup condenses the PHIP protocol into a pulse-program that in turn can be readily shared in the manner of traditional pulse sequences. In this device, a TTL multiplexer was constructed to convert spectrometer TTL outputs into 24 VDC signals. These signals then activated solenoid valves to control chemical shuttling and reactivity in PHIP experiments. Consolidating these steps in a pulse-programming environment speeded calibration and improved quality assurance by enabling the B 0 /B 1 fields to be tuned based on the direct acquisition of thermally polarized and hyperpolarized NMR signals. Performance was tested on the parahydrogen addition product of 2-hydroxyethyl propionate-1- 13 C-d 3 , where the 13 C polarization was estimated to be P 13C =20±2.5% corresponding to 13 C signal enhancement approximately 25 million-fold at 9.1 mT or approximately 77,000-fold 13 C enhancement at 3 T with respect to thermally induced polarization at room temperature. Copyright © 2017 Elsevier Inc. All rights reserved.
DEFF Research Database (Denmark)
Viezzoli, Andrea; Kaminskiy, Vladislav; Fiandaca, Gianluca
2017-01-01
We have developed a synthetic multiparametric modeling and inversion exercise undertaken to study the robustness of inverting airborne time-domain electromagnetic (TDEM) data to extract Cole-Cole parameters. The following issues were addressed: nonuniqueness, ill posedness, dependency on manual...... constrained multiparametric inversion was evaluated, including recovery of chargeability distributions from shallow and deep targets based on analysis of induced polarization (IP) effects, simulated in airborne TDEM data. Different scenarios were studied, including chargeable targets associated...... by a shallower chargeable target, became possible only when full Cole-Cole modeling was used in the inversion. Lateral constraints improved the recoverability of model parameters. Finally, modeling IP effects increased the accuracy of recovered electrical resistivity models....
Aspmo Pfaffhuber, Andreas; Grimstad, Eystein; Domaas, Ulrik; Auken, Esben; Halkjær, Max
2010-05-01
The inner Aurland fjord and the adjacent Flåm valley (Western Norway) are subject to a potential rock slide comprised of creeping rock- and debris masses. From repeated GPS measurements we understand that rock and debris movements are constrained by precipitation and snow melt. Based on this assumption the local municipality and regional hydroelectricity company are evaluating the option to drain the unstable area with a more than 10 km long drainage tunnel to a nearby hydropower reservoir. We conducted an airborne electromagnetic (AEM) mapping survey to find indications for the sliding planes and to assess the tunnel corridor for potential tunneling hazard areas. Unstable rock areas some 1.000 meters above seawater have been mapped as massive phyllite intercepted by numerous tension cracks opening up to several meters. Field observations also point out that significant amounts of surface water in streams on the mountain plateau disappear in some of these cracks and surface again several hundred meters down the slope. Potentially sliding planes provide the water pathways and the changes in water pressure can cause instability. As the phyllite will weather to fine grained clay the water saturated sliding planes should be an ideal target for AEM as they are very conductive (1-10 Ohm*m) in comparison to the resistive undisturbed phyllite or nearby gneiss (> 1.000 Ohm*m). From our first AEM data interpretation we find widespread areas with high conductivity, which are most likely caused by either water saturated, fine grained sliding planes or fault zones at the phyllite / gneiss interface. At this point, financing for drilling is pending to transform the geophysical maps to a firm geological model. Based on the AEM results, we are formulating a joint research program involving detailed hydrological investigations, monitoring of formation water pressure, movements, meteorology, more detailed structural mapping and geophysical ground follow up of the airborne data. We
International Nuclear Information System (INIS)
Kim, Se Yun
2009-01-01
This book deals with engineering electromagnetics. It contains seven chapters, which treats understanding of engineering electromagnetics such as magnet and electron spin, current and a magnetic field and an electromagnetic wave, Essential tool for engineering electromagnetics on rector and scalar, rectangular coordinate system and curl vector, electrostatic field with coulomb rule and method of electric images, Biot-Savart law, Ampere law and magnetic force, Maxwell equation and an electromagnetic wave and reflection and penetration of electromagnetic plane wave.
International Nuclear Information System (INIS)
Bakker, J F; Paulides, M M; Van Rhoon, G C; Christ, A; Kuster, N
2010-01-01
To avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels from the basic restrictions on the induced whole-body-averaged specific absorption rate (SAR wb ) and the peak 10 g spatial-averaged SAR (SAR 10g ). The objective of this study is to assess if the SAR in children remains below the basic restrictions upon exposure at the reference levels. Finite difference time domain (FDTD) modeling was used to calculate the SAR in six children and two adults when exposed to all 12 orthogonal plane wave configurations. A sensitivity study showed an expanded uncertainty of 53% (SAR wb ) and 58% (SAR 10g ) due to variations in simulation settings and tissue properties. In this study, we found that the basic restriction on the SAR wb is occasionally exceeded for children, up to a maximum of 45% in small children. The maximum SAR 10g values, usually found at body protrusions, remain under the limit for all scenarios studied. Our results are in good agreement with the literature, suggesting that the recommended ICNIRP reference levels may need fine tuning.
Energy Technology Data Exchange (ETDEWEB)
Bakker, J F; Paulides, M M; Van Rhoon, G C [Erasmus MC-Daniel den Hoed Cancer Center, Department of Radiation Oncology, Section Hyperthermia, PO box 5201, NL-3008 AE, Rotterdam (Netherlands); Christ, A; Kuster, N, E-mail: j.bakker@erasmusmc.n [Foundation for Research on Information Technologies in Society (IT' IS) (Switzerland)
2010-06-07
To avoid potentially adverse health effects of electromagnetic fields (EMF), the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has defined EMF reference levels from the basic restrictions on the induced whole-body-averaged specific absorption rate (SAR{sub wb}) and the peak 10 g spatial-averaged SAR (SAR{sub 10g}). The objective of this study is to assess if the SAR in children remains below the basic restrictions upon exposure at the reference levels. Finite difference time domain (FDTD) modeling was used to calculate the SAR in six children and two adults when exposed to all 12 orthogonal plane wave configurations. A sensitivity study showed an expanded uncertainty of 53% (SAR{sub wb}) and 58% (SAR{sub 10g}) due to variations in simulation settings and tissue properties. In this study, we found that the basic restriction on the SAR{sub wb} is occasionally exceeded for children, up to a maximum of 45% in small children. The maximum SAR{sub 10g} values, usually found at body protrusions, remain under the limit for all scenarios studied. Our results are in good agreement with the literature, suggesting that the recommended ICNIRP reference levels may need fine tuning.
Masalov, E. V.; Krivin, N. N.; Eshchenko, S. Yu.
2018-01-01
The influence of a homogeneous medium filled with water droplets on the polarization structure of electromagnetic waves propagating in it, emitted in series with horizontal and circular (e.g., right-handed) polarization, is considered. An approach is proposed for estimating the influence of the resulting transformation of the polarization structure on the magnitude of the modified radar reflectivity, based on the use of the functional dependence of the components of the Jones vector on the angle of ellipticity and the tilt angle of the polarization ellipse. A distinguishing feature of the proposed approach consists in the relationships calculated using it for determining the modified radar reflectivity, obtained for the case of backscattering by the medium, where the orientation of the polarization basis of the medium is different from that of the measurement basis. Estimates of the modified radar reflectivity have been obtained, allowing one to determine regions with elevated values of this parameter.
Polarized light for horizontal incidence and reflection by plane-parallel atmospheres
Hovenier, J.W.; Stam, D.M.
2007-01-01
We show that the intensity vector of light reflected by a plane-parallel atmosphere is discontinuous if the directions of incidence and reflection are both horizontal. An exact expression describing the discontinuity is presented. This expression shows that the discontinuity is only due to first
Directory of Open Access Journals (Sweden)
S. O. Hulyar
2015-09-01
Full Text Available An existence of separate functional system of electromagnetic balance regulation has been substantiated and a working conception of light puncture has been formulated. As a basis, there is a possibility to use the acupuncture points for input of biologically necessary electromagnetic waves into the system of their conductors in a body that might be considered as a transport facility for energy ofthe polarized electromagnetic waves. Zones-recipients are organs having an electromagnetic disbalance due to excess of biologically inadequate radiation and being the targets for peroxide oxidation, foremost, a body has the neurohormonal and immune regulatory systems. Electromagnetic stimulation or modification of functions of the zones-recipients determines achievement of therapeutic and useful effects, and their combination with local reparative processes allows attaining a clinical goal. We represent own and literary experimental data about development of physiological responses (analgesia, bronchospasm control, immune stimulation and inhibition of peroxide oxidation of lipids to BIOPTRON-light exposure on the acupuncture points or biologically active zones. We show the experimental facts in support of a hypothesis that a living organism can perceive an action of the electromagnetic waves of optical range not only via the visual system, but also through the off-nerve receptors (specific energy-sensitive proteins detecting critical changes of energy in cells and functioning as the "sensory" cell systems, as well as via the acupuncture points. This confirms an important role of the electromagnetic waves of optical range in providing normal vital functions of living organisms. A current approach to BIOPTRON light therapy consists in combined (local and system exposure of the electromagnetic waves within the biologically necessary range.
Amplitude and dynamics of polarization-plane signaling in the central complex of the locust brain.
Bockhorst, Tobias; Homberg, Uwe
2015-05-01
The polarization pattern of skylight provides a compass cue that various insect species use for allocentric orientation. In the desert locust, Schistocerca gregaria, a network of neurons tuned to the electric field vector (E-vector) angle of polarized light is present in the central complex of the brain. Preferred E-vector angles vary along slices of neuropils in a compasslike fashion (polarotopy). We studied how the activity in this polarotopic population is modulated in ways suited to control compass-guided locomotion. To this end, we analyzed tuning profiles using measures of correlation between spike rate and E-vector angle and, furthermore, tested for adaptation to stationary angles. The results suggest that the polarotopy is stabilized by antagonistic integration across neurons with opponent tuning. Downstream to the input stage of the network, responses to stationary E-vector angles adapted quickly, which may correlate with a tendency to steer a steady course previously observed in tethered flying locusts. By contrast, rotating E-vectors corresponding to changes in heading direction under a natural sky elicited nonadapting responses. However, response amplitudes were particularly variable at the output stage, covarying with the level of ongoing activity. Moreover, the responses to rotating E-vector angles depended on the direction of rotation in an anticipatory manner. Our observations support a view of the central complex as a substrate of higher-stage processing that could assign contextual meaning to sensory input for motor control in goal-driven behaviors. Parallels to higher-stage processing of sensory information in vertebrates are discussed. Copyright © 2015 the American Physiological Society.
Ali, P. A.; Al-Hussany, A. F.; Bennett, C. A.; Hancock, D. A.; El-Sharkawi, A. M.
1998-08-01
A plane polarized x-ray fluorescence system based on an orthovoltage radiotherapy treatment unit, the Pantak DXT-300, has been developed and optimized to measure tumour platinum concentration. The platinum derives from platinum based chemotherapy agents, such as cisplatin and carboplatin used to treat tumours in the head and neck region. Photons from an x-ray tube are polarized by scattering through , and used to stimulate the emission of characteristic platinum x-rays from the tumour. Information about the drug in the tumour could be of use in establishing dose-response relationships, in order to optimize the treatment and reduce the toxicity of the drug. The performance of the system was optimized with respect to the applied x-ray tube voltage, the current and the filter material; the effect on the minimum detection limit (MDL) of the thickness of the overlying tissue surrounding the tumour was investigated in detail. The lowest MDL is achieved using 0.25 mm of tin filter and x-ray tube voltage of 220 kV. This is 5.6 ppm for a tumour surrounded with 20 mm of overlying tissue, a measurement time of 2000 s and an estimated skin dose of 3.0 mGy. This represents the most sensitive in vivo XRF system to date. We have embarked on a clinical pilot study to measure the platinum concentration in tumours of the head and neck, and expect initial results to be available in the near future.
Grant, Ian S
1990-01-01
The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw the Physics of Stars Second Edition A. C. Phillips Computing for Scient
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H. Fujiwara
2007-11-01
Full Text Available From simultaneous observations of the European incoherent scatter Svalbard radar (ESR and the Cooperative UK Twin Located Auroral Sounding System (CUTLASS Finland radar on 9 March 1999, we have derived the height distributions of the thermospheric heating rate at the F region height in association with electromagnetic energy inputs into the dayside polar cap/cusp region. The ESR and CUTLASS radar observations provide the ionospheric parameters with fine time-resolutions of a few minutes. Although the geomagnetic activity was rather moderate (Kp=3^{+}~4, the electric field obtained from the ESR data sometimes shows values exceeding 40 mV/m. The estimated passive energy deposition rates are also larger than 150 W/kg in the upper thermosphere over the ESR site during the period of the enhanced electric field. In addition, enhancements of the Pedersen conductivity also contribute to heating the upper thermosphere, while there is only a small contribution for thermospheric heating from the direct particle heating due to soft particle precipitation in the dayside polar cap/cusp region. In the same period, the CUTLASS observations of the ion drift show the signature of poleward moving pulsed ionospheric flows with a recurrence rate of about 10–20 min. The estimated electromagnetic energy deposition rate shows the existence of the strong heat source in the dayside polar cap/cusp region of the upper thermosphere in association with the dayside magnetospheric phenomena of reconnections and flux transfer events.
Directory of Open Access Journals (Sweden)
H. Fujiwara
2007-11-01
Full Text Available From simultaneous observations of the European incoherent scatter Svalbard radar (ESR and the Cooperative UK Twin Located Auroral Sounding System (CUTLASS Finland radar on 9 March 1999, we have derived the height distributions of the thermospheric heating rate at the F region height in association with electromagnetic energy inputs into the dayside polar cap/cusp region. The ESR and CUTLASS radar observations provide the ionospheric parameters with fine time-resolutions of a few minutes. Although the geomagnetic activity was rather moderate (Kp=3+~4, the electric field obtained from the ESR data sometimes shows values exceeding 40 mV/m. The estimated passive energy deposition rates are also larger than 150 W/kg in the upper thermosphere over the ESR site during the period of the enhanced electric field. In addition, enhancements of the Pedersen conductivity also contribute to heating the upper thermosphere, while there is only a small contribution for thermospheric heating from the direct particle heating due to soft particle precipitation in the dayside polar cap/cusp region. In the same period, the CUTLASS observations of the ion drift show the signature of poleward moving pulsed ionospheric flows with a recurrence rate of about 10–20 min. The estimated electromagnetic energy deposition rate shows the existence of the strong heat source in the dayside polar cap/cusp region of the upper thermosphere in association with the dayside magnetospheric phenomena of reconnections and flux transfer events.
Kawai, Hiroki; Nagaoka, Tomoaki; Watanabe, Soichi; Saito, Kazuyuki; Takahashi, Masaharu; Ito, Koichi
2010-01-01
This paper presents calculated specific absorption rate (SAR) dosimetry in 4 and 8 week Japanese pregnant-woman models exposed to plane waves over the frequency range of 10 MHz-1.5 GHz. Two types of 2 mm spatial-resolution pregnant-woman models comprised a woman model, which is similar to the average-sized Japanese adult female in height and weight, with a cubic (4 week) embryo or spheroidal (8 week) one. The averaged SAR in the embryos exposed to vertically and horizontally polarized plane waves at four kinds of propagation directions are calculated from 10 MHz to 1.5 GHz. The results indicate that the maximum average SAR in the embryos exposed to plane waves is lower than 0.08 W kg-1 when the incident power density is at the reference level of ICNIRP guideline for general public environment.
Modulation of electromagnetic fields by a depolarizer of random polarizer array
DEFF Research Database (Denmark)
Ma, Ning; Hanson, Steen Grüner; Wang, Wei
2016-01-01
The statistical properties of the electric fields with random changes of the polarization state in space generated by a depolarizer are investigated on the basis of the coherence matrix. The depolarizer is a polarizer array composed of a multitude of contiguous square cells of polarizers with ran......The statistical properties of the electric fields with random changes of the polarization state in space generated by a depolarizer are investigated on the basis of the coherence matrix. The depolarizer is a polarizer array composed of a multitude of contiguous square cells of polarizers...... with randomly distributed polarization angles, where the incident fields experience a random polarization modulation after passing through the depolarizer. The propagation of the modulated electric fields through any quadratic optical system is examined within the framework of the complex ABCD matrix to show...
International Nuclear Information System (INIS)
Rekalo, M.P.; Tomasi-Gustafsson, E.
1996-01-01
We analyze the properties of the inclusive d + p-reactions, with particular interest in the domain of nucleonic resonances excitation. The calculated cross section and polarization observables show that it is possible to disentangle the different reaction mechanisms (ω-,σ-, n- exchange) and bring new information about the electromagnetic form factors of the deuteron as well as of the nucleonic resonances excitation. Existing data on the tensor analyzing power are in agreement with the predictions based on the ω-exchange model. (authors)
Energy Technology Data Exchange (ETDEWEB)
Rekalo, M.P.; Tomasi-Gustafsson, E.
1996-12-31
We analyze the properties of the inclusive d + p-reactions, with particular interest in the domain of nucleonic resonances excitation. The calculated cross section and polarization observables show that it is possible to disentangle the different reaction mechanisms ({omega}-,{sigma}-, n- exchange) and bring new information about the electromagnetic form factors of the deuteron as well as of the nucleonic resonances excitation. Existing data on the tensor analyzing power are in agreement with the predictions based on the {omega}-exchange model. (authors). 18 refs.
Zhang, Yuantao; Dong, Xin; Li, Guoxing; Li, Wancheng; Zhang, Baolin; Du, Guotong
2013-03-01
We report the growth of atomically smooth N-polar GaN on c-plane sapphire by metalorganic vapor phase epitaxy. A two-step growth technique was adopted; low-temperature growth of GaN buffer before high-temperature GaN growth. The complete two-dimensional N-polar GaN growth process was recorded by in situ reflectance. The phase composition of the low-temperature GaN was examined by X-ray diffraction pole figure measurements. The thickness of the low-temperature GaN buffer dramatically affected the crystalline and electronic properties of the N-polar GaN. A very small full width at half maximum for the (0 0 0 2) X-ray rocking curve, 51 arcs, was obtained for 700-nm-thick N-polarity GaN by optimizing the buffer thickness.
Liszka, Małgorzata; Stolarczyk, Liliana; Kłodowska, Magdalena; Kozera, Anna; Krzempek, Dawid; Mojżeszek, Natalia; Pędracka, Anna; Waligórski, Michael Patrick Russell; Olko, Paweł
2018-01-01
To evaluate the effect on charge collection in the ionization chamber (IC) in proton pencil beam scanning (PBS), where the local dose rate may exceed the dose rates encountered in conventional MV therapy by up to three orders of magnitude. We measured values of the ion recombination (k s ) and polarity (k pol ) correction factors in water, for a plane-parallel Markus TM23343 IC, using the cyclotron-based Proteus-235 therapy system with an active proton PBS of energies 30-230 MeV. Values of k s were determined from extrapolation of the saturation curve and the Two-Voltage Method (TVM), for planar fields. We compared our experimental results with those obtained from theoretical calculations. The PBS dose rates were estimated by combining direct IC measurements with results of simulations performed using the FLUKA MC code. Values of k s were also determined by the TVM for uniformly irradiated volumes over different ranges and modulation depths of the proton PBS, with or without range shifter. By measuring charge collection efficiency versus applied IC voltage, we confirmed that, with respect to ion recombination, our proton PBS represents a continuous beam. For a given chamber parameter, e.g., nominal voltage, the value of k s depends on the energy and the dose rate of the proton PBS, reaching c. 0.5% for the TVM, at the dose rate of 13.4 Gy/s. For uniformly irradiated regular volumes, the k s value was significantly smaller, within 0.2% or 0.3% for irradiations with or without range shifter, respectively. Within measurement uncertainty, the average value of k pol , for the Markus TM23343 IC, was close to unity over the whole investigated range of clinical proton beam energies. While no polarity effect was observed for the Markus TM23343 IC in our pencil scanning proton beam system, the effect of volume recombination cannot be ignored. © 2017 American Association of Physicists in Medicine.
Vacuum polarization effects in the (μ-4He)+ atom and the Born-Infeld electromagnetic theory
International Nuclear Information System (INIS)
Iacopini, E.; Zavattini, E.
1983-01-01
It is shown that the Born-Infeld nonlinear electromagnetic theory predicts the n = 2 fine-structure differences in the (μ -4 He) + system in fair agreement with the experimental results. A discussion on the birifrangence induced in vacuum by a static magnetic field within the frame of classical Born-Infeld-type theories is also presented
Maruyama, R.; Bigault, T.; Wildes, A. R.; Dewhurst, C. D.; Saerbeck, T.; Honecker, D.; Yamazaki, D.; Soyama, K.; Courtois, P.
2017-06-01
Polarized neutron off-specular and grazing-incidence small-angle scattering measurements are useful methods to investigate the in-plane structure and its correlation of layered systems. Although these measurements give information on complementary and overlapping length scale, the different characteristics between them need to be taken into account when performed. In this study, the difference in the accessible length scale of the in-plane structure, which is one of the most important characteristics, was discussed using an Fe/Si multilayer together with simulations based on the distorted wave Born approximation.
Zhong, Hui-Teng; Yang, Xue-Xia; Song, Xing-Tang; Guo, Zhen-Yue; Yu, Fan
2017-11-01
In this work, we introduced the design, demonstration, and discussion of a wideband metamaterial array with polarization-independent and wide-angle for harvesting ambient electromagnetic (EM) energy and wireless power transfer. The array consists of unit cells with one square ring and four metal bars. In comparison to the published metamaterial arrays for harvesting EM energy or wireless transfer, this design had the wide operation bandwidth with the HPBW (Half Power Band Width) of 110% (6.2 GHz-21.4 GHz), which overcomes the narrow-band operation induced by the resonance characteristic of the metamaterial. On the normal incidence, the simulated maximum harvesting efficiency was 96% and the HPBW was 110% for the random polarization wave. As the incident angle increases to 45°, the maximum efficiency remained higher than 88% and the HPBW remained higher than 83% for the random polarization wave. Furthermore, the experimental verification of the designed metamaterial array was conducted, and the measured results were in reasonable agreement with the simulated ones.
Electromagnetic fields of an ultra-short tightly-focused radially-polarized laser pulse
Salamin, Yousef I.; Li, Jian-Xing
2017-12-01
Fully analytic expressions, for the electric and magnetic fields of an ultrashort and tightly focused laser pulse of the radially polarized category, are presented to lowest order of approximation. The fields are derived from scalar and vector potentials, along the lines of our earlier work for a similar pulse of the linearly polarized variety. A systematic program is also described from which the fields may be obtained to any desired accuracy, analytically or numerically.
Zhang, Feng; Ikeda, Masao; Zhang, Shu-Ming; Liu, Jian-Ping; Tian, Ai-Qin; Wen, Peng-Yan; Cheng, Yang; Yang, Hui
2016-12-01
The polarization fields in c-plane InGaN/(In)GaN multiple quantum well (MQW) structures grown on sapphire substrate by metal-organic chemical vapor deposition are investigated in this paper. The indium composition in the quantum wells varies from 14.8 to 26.5% for different samples. The photoluminescence wavelengths are calculated theoretically by fully considering the related effects and compared with the measured wavelengths. It is found that when the indium content is lower than 17.3%, the measured wavelengths agree well with the theoretical values. However, when the indium content is higher than 17.3%, the measured ones are much shorter than the calculation results. This discrepancy is attributed to the reduced polarization field in the MQWs. For the MQWs with lower indium content, 100% theoretical polarization can be maintained, while, when the indium content is higher, the polarization field decreases significantly. The polarization field can be weakened down to 23% of the theoretical value when the indium content is 26.5%. Strain relaxation is excluded as the origin of the polarization reduction because there is no sign of lattice relaxation in the structures, judging by the X-ray diffraction reciprocal space mapping. The possible causes of the polarization reduction are discussed.
Electromagnetic Power Harvester Using Wide-Angle and Polarization-Insensitive Metasurfaces
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Xuanming Zhang
2018-03-01
Full Text Available A new wide-angle and polarization-insensitive metasurface (MS instead of traditional antenna is built as the primary ambient energy harvester in this paper. The MS is a two-dimensional energy harvesting array that is composed of subwavelength electrical small ring resonator that is working at 2.5 GHz (LTE/WiFi. In the case of different polarization and incidence angles, we demonstrate the metasurface can achieve high harvesting efficiency of 90%. The fabricated prototype of 9 × 9 MS energy harvesting array is measured, and the experimental results validate that the proposed MS has a good performance more than 80% of energy harvesting efficiency for arbitrary polarization and wide-angle incident waves. The good agreement of the simulation with the experiment results verifies the practicability and effectiveness of the proposed MS structure, which will provide a new source of supply in wireless sensor networks (WSN.
Calvo, Florent
2015-03-01
The nonlinear response and dissociation propensity of an isolated chiral molecule, camphor, to a circularly polarized infrared laser pulse was simulated by molecular dynamics as a function of the excitation wavelength. The results indicate similarities with linear absorption spectra, but also differences that are ascribable to dynamical anharmonic effects. Comparing the responses between left- and right-circularly polarized pulses in terms of dissociation probabilities, or equivalently between R- and S-camphor to a similarly polarized pulse, we find significant differences for the fingerprint C = O amide mode, with a sensitivity that could be sufficient to possibly enable vibrational circular dichroism as an action technique for probing molecular chirality and absolute conformations in the gas phase. © 2015 Wiley Periodicals, Inc.
International Nuclear Information System (INIS)
Baird, Kenneth G.
1996-08-01
We present the first measurement of the correlation between the Z 0 spin and the event plane orientation in polarized Z 0 decays into three jets in the SLD experiment at SLAC utilizing a longitudinally polarized electron beam. The CP even and T odd triple product rvec S Z · (rvec k 1 x rvec k 2 ) formed from the two fastest jet momenta, rvec k 1 and rvec k 2 , and the Z 0 polarization vector rvec S Z , is sensitive to physics beyond the Standard Model. We measure the expectation value of this quantity to be consistent with zero and Set 95% C.L. limits of -0.022< β <0.039 on the correlation
DEFF Research Database (Denmark)
Wang, Wei; Zhao, Juan; Hu, Xiaoying
2017-01-01
All optical fields undergo random fluctuation and the underlying theory referred to as coherence and polarization of optical fields has played a fundamental role as an important manifestation of the random fluctuations of the electric fields. In this paper, we reviewed our recent theoretical...
Mota, R. D.; Xicoténcatl, M. A.; Granados, V. D.
2004-02-01
In this work we introduce a generalization of the Jauch and Rohrlich quantum Stokes operators when the arrival direction from the source is unknown a priori. We define the generalized Stokes operators as the Jordan-Schwinger map of a triplet of harmonic oscillators with the Gell-Mann and Ne'eman matrices of the SU(3) symmetry group. We show that the elements of the Jordan-Schwinger map are the constants of motion of the three-dimensional isotropic harmonic oscillator. Also, we show that the generalized Stokes operators together with the Gell-Mann and Ne'eman matrices may be used to expand the polarization matrix. By taking the expectation value of the Stokes operators in a three-mode coherent state of the electromagnetic field, we obtain the corresponding generalized classical Stokes parameters. Finally, by means of the constants of motion of the classical 3D isotropic harmonic oscillator we describe the geometrical properties of the polarization ellipse.
Energy Technology Data Exchange (ETDEWEB)
Mota, R D [Unidad Profesional Interdisciplinaria de IngenierIa y TecnologIas Avanzadas, IPN. Av. Instituto Politecnico Nacional 2580, Col. La Laguna Ticoman, 07340 Mexico DF (Mexico); Xicotencatl, M A [Departamento de Matematicas del Centro de Investigacion y Estudios Avanzados del IPN, Mexico DF, 07000 (Mexico); Granados, V D [Escuela Superior de FIsica y Matematicas, Instituto Politecnico Nacional, Ed. 9, Unidad Profesional Adolfo Lopez Mateos, 07738 Mexico DF (Mexico)
2004-02-20
In this work we introduce a generalization of the Jauch and Rohrlich quantum Stokes operators when the arrival direction from the source is unknown a priori. We define the generalized Stokes operators as the Jordan-Schwinger map of a triplet of harmonic oscillators with the Gell-Mann and Ne'eman matrices of the SU(3) symmetry group. We show that the elements of the Jordan-Schwinger map are the constants of motion of the three-dimensional isotropic harmonic oscillator. Also, we show that the generalized Stokes operators together with the Gell-Mann and Ne'eman matrices may be used to expand the polarization matrix. By taking the expectation value of the Stokes operators in a three-mode coherent state of the electromagnetic field, we obtain the corresponding generalized classical Stokes parameters. Finally, by means of the constants of motion of the classical 3D isotropic harmonic oscillator we describe the geometrical properties of the polarization ellipse.
Energy Technology Data Exchange (ETDEWEB)
Morgan, F. Dale; Sogade, John
2004-12-14
This project was designed as a broad foundational study of spectral induced polarization (SIP) for characterization of contaminated sites. It encompassed laboratory studies of the effects of chemistry on induced polarization, development of 3D forward modeling and inversion codes, and investigations of inductive and capacitive coupling problems. In the laboratory part of the project a physico-chemical model developed in this project was used to invert laboratory IP spectra for the grain size and the effective grain size distribution of the sedimentary rocks as well as the formation factor, porosity, specific surface area, and the apparent fractal dimension. Furthermore, it was established that the IP response changed with the solution chemistry, the concentration of a given solution chemistry, valence of the constituent ions, and ionic radius. In the field part of the project, a 3D complex forward and inverse model was developed. It was used to process data acquired at two frequencies (1/16 Hz and 1/ 4Hz) in a cross-borehole configuration at the A-14 outfall area of the Savannah River Site (SRS) during March 2003 and June 2004. The chosen SRS site was contaminated with Tetrachloroethylene (TCE) and Trichloroethylene (PCE) that were disposed in this area for several decades till the 1980s. The imaginary conductivity produced from the inverted 2003 data correlated very well with the log10 (PCE) concentration derived from point sampling at 1 ft spacing in five ground-truth boreholes drilled after the data acquisition. The equivalent result for the 2004 data revealed that there were significant contaminant movements during the period March 2003 and June 2004, probably related to ground-truth activities and nearby remediation activities. Therefore SIP was successfully used to develop conceptual models of volume distributions of PCE/TCE contamination. In addition, the project developed non-polarizing electrodes that can be deployed in boreholes for years. A total of 28
Energy Technology Data Exchange (ETDEWEB)
Campione, Salvatore [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Warne, Larry K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sainath, Kamalesh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Basilio, Lorena I. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2017-10-01
In this report we overview the fundamental concepts for a pair of techniques which together greatly hasten computational predictions of electromagnetic pulse (EMP) excitation of finite-length dissipative conductors over a ground plane. In a time- domain, transmission line (TL) model implementation, predictions are computationally bottlenecked time-wise, either for late-time predictions (about 100ns-10000ns range) or predictions concerning EMP excitation of long TLs (order of kilometers or more ). This is because the method requires a temporal convolution to account for the losses in the ground. Addressing this to facilitate practical simulation of EMP excitation of TLs, we first apply a technique to extract an (approximate) complex exponential function basis-fit to the ground/Earth's impedance function, followed by incorporating this into a recursion-based convolution acceleration technique. Because the recursion-based method only requires the evaluation of the most recent voltage history data (versus the entire history in a "brute-force" convolution evaluation), we achieve necessary time speed- ups across a variety of TL/Earth geometry/material scenarios. Intentionally Left Blank
Benito, L.
2018-04-01
Owing to its high-sensitivity, reliability, fast, versatile and cost-effective operation, vibrating sample magnetometers (VSM) are massively popular characterization instruments at Magnetism laboratories worldwide. Nevertheless, the inherent appearance of synchronous noise represents a major drawback, which critically limits the fine probing of nanometer-sized media. I here report on an innovative approach to eliminate synchronous noise in VSM. This consists of fitting engineered mechanical devices that absorbs vibration energy, dissipating that into heat. Complementarily, a novel transversal pick-up coil system is also presented and analyzed; this detection system has been engineered to enhance the noise-to-signal ratio and optimized for measuring small size thin film samples. The implementation of a combined mechanical and electromagnetic approach enables to notably enhance the VSM performance, achieving a sensitivity better than 1 ×10-6 emu and a resolution below 5 ×10-8 emu, so that the magnetization vector in nanostructured media can be accurately mapped out down to cryogenic temperatures. I lastly show precision magnetometry measurements carried out in an epitaxial (0 0 1)-oriented 200 nm-thick Ni thin film. The analysis reveals the arising of an in-plane dominating strain-induced uniaxial magnetic anisotropy, K2ef = - 6.455kJ m - 3 , and a stunning piezo-spin-polarization effect resulting in a remarkable 10% modulation of the magnetization vector, ∼ 27 emu/cm3, with respect to the cubic lattice axes. Both effects are attributed to the likely existence of an orthorhombic lattice distortion, i.e.εxx -εyy ≈ - 2 ×10-3 . This categorical link enables to assign the observed anisotropic spin-polarization in the Ni overlayer to a two-ion magnetoelastic coupling effect.
International Nuclear Information System (INIS)
Sanchez-Arriaga, G.; Lefebvre, E.
2011-01-01
The dynamics of two-dimensional s-polarized solitary waves is investigated with the aid of particle-in-cell (PIC) simulations. Instead of the usual excitation of the waves with a laser pulse, the PIC code was directly initialized with the numerical solutions from the fluid plasma model. This technique allows the analysis of different scenarios including the theoretical problems of the solitary wave stability and their collision as well as features already measured during laser-plasma experiments such as the emission of electromagnetic bursts when the waves reach the plasma-vacuum interface, or their expansion on the ion time scale, usually named post-soliton evolution. Waves with a single density depression are stable whereas multihump solutions decay to several waves. Contrary to solitons, two waves always interact through a force that depends on their relative phases, their amplitudes, and the distance between them. On the other hand, the radiation pattern at the plasma-vacuum interface was characterized, and the evolution of the diameter of different waves was computed and compared with the ''snow plow'' model.
International Nuclear Information System (INIS)
Chahine, C.; College de France, 75 - Paris. Lab. de Physique Corpusculaire)
1978-02-01
The concept of a real photon spectral weight function for any cross-section involving charged particles is introduced as a simple approximation taking into account the soft part of photon emission to all orders in perturbation theory. The spectral weight function replaces the energy-momentum conservation delta function in the elastic cross-section. The spectral weight function is computed in closed form in space-time and in the peaking approximation in momentum space. The spectral weight function description is applied to the imaginary part of vacuum polarization ImPI and to electron-proton scattering. A spectral representation for ImPI is derived and its content compared with the known fourth order result, showing in particular the identity of the soft and peaking approximations in lowest order. The virtual photon radiative corrections are discussed in part, with emphasis on the threshold behavior of the vertex functions. A relativistic generalization of the electric non-relativistic vertex function is given, whose asymptotic behavior is approppriate to use in conjuction with the spectral weight function
Inclusive quasielastic scattering of polarized electrons from polarized nuclei
Energy Technology Data Exchange (ETDEWEB)
Amaro, J.E. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Center for Theoretical Physics]|[Universidad de Granada (Spain). Dept. de Fisica Moderna]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Lab. for Nuclear Science]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics; Caballero, J.A. [Consejo Superior de Investigaciones Cientificas (CSIC), Madrid (Spain). Inst. de Estructura de la Materia]|[Sevilla Univ. (Spain). Dept. de Fisica Atomica, Molecular y Nuclear; Donnelly, T.W. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Center for Theoretical Physics]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Lab. for Nuclear Science]|[Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics; Moya de Guerra, E. [Consejo Superior de Investigaciones Cientificas (CSIC), Madrid (Spain). Inst. de Estructura de la Materia
1996-12-23
The inclusive quasielastic response functions that appear in the scattering of polarized electrons from polarized nuclei are computed and analyzed for several closed-shell-minus-one nuclei with special attention paid to {sup 39}K. Results are presented using two models for the ejected nucleon - when described by a distorted wave in the continuum shell model or by a plane wave in PWIA with on- and off-shell nucleons. Relativistic effects in kinematics and in the electromagnetic current have been incorporated throughout. Specifically, the recently obtained expansion of the electromagnetic current in powers only of the struck nucleon`s momentum is employed for the on-shell current and the effects of the first-order terms (spin-orbit and convection) are compared with the zeroth-order (charge and magnetization) contributions. The use of polarized inclusive quasielastic electron scattering as a tool for determining near-valence nucleon momentum distributions is discussed. (orig.).
Elements particle decay in the field of an intense electromagnetic wave
International Nuclear Information System (INIS)
Lyul'ka, V.A.
1975-01-01
The μ +- →E +- +ν+ν tilde, π→μ(e)+ν, π +- →π deg +e +- +ν, decays and also the e +- →e +- +ν+ν tilde process in an intense electromagnetic field of a plane electromagnetic wave with an arbitrary polarization and in a field of linearly polarized waves with mutually perpendicular polarizations and with the same propagation are considered here. Expressions have been obtained for probabilities of the decays for both models of electromagnetic field, and numerical calculations have been carried out for specific values of invariant parameters, that determine the external field effect on elementary particle decays. Characteristic features of the dependence of total probabilities of particle decays on a frequency, and also on an external electromagnetic wave polarization are discussed
International Nuclear Information System (INIS)
Yao Jinping; Zeng Bin; Fu Yuxi; Chu Wei; Ni Jielei; Li Yao; Xiong Hui; Xu Han; Cheng Ya; Xu Zhizhan; Liu Xiaojun; Chen, J.
2010-01-01
We theoretically investigate the high-order harmonic generation (HHG) in helium using a two-color laser field synthesized by an intense 25-fs laser pulse at 800 nm and a relatively weak ∼43-fs laser pulse at 1400 nm. When the polarization between the two pulses is arranged at an angle of ∼73 deg., supercontinuum spectra are dramatically broadened to 180 eV, which is sufficient to support an isolated ∼73-as pulse without any phase compensation. The physical mechanisms behind the phenomenon are well explained in terms of quantum and classical analyses. Furthermore, in the long-pulse regime, this method of extending the supercontinuum spectrum shows the significant advantage over previous two-color HHG schemes.
MATHEMATICAL PREDICTION, PROBABILITY, AIRCRAFT ANTENNAS, ELECTROMAGNETIC RADIATION , FLIGHT DECKS, EXPLOSIVES INITIATORS, SHIPBOARD, ANGLE OF ATTACK, VOLTAGE, RADIOFREQUENCY, RANGE(DISTANCE), HANGARS.
Broadband electromagnetic environments simulator (EMES)
International Nuclear Information System (INIS)
Pollard, N.
1977-01-01
A new test facility has been developed by Sandia Laboratories for determining the effects of electromagnetic environments on systems and components. The facility is capable of producing uniform, vertically polarized, continuous wave (CW) and pulsed fields over the frequency range of dc to 10 GHz. This broadband capability addresses the electromagnetic radiation (EMR) threat and is ideally suited to computer controlled sweeping and data acquisition. EMES is also capable of producing uniform transient fields having the wave shape and magnitude characteristic of a nuclear electromagnetic pulse (EMP) and near lightning. The design consists of a truncated, triplate, rectangular coaxial transmission line. The spacing between the flat center conductor and the ground planes is 4 meters. The line is terminated in its characteristic impedance of 50 ohms. At frequencies below the first resonance of the facility it behaves as a typical coaxial system. Above resonance, a wall of electromagnetic absorbing material provides a nonreflecting termination. Thus, EMES essentially combines the elements of a transmission line and an anechoic chamber. It will not radiate electromagnetic energy into the surrounding area because it is a shielded transmission line
International Nuclear Information System (INIS)
Nagaoka, Tomoaki; Togashi, Toshihiro; Saito, Kazuyuki; Takahashi, Masaharu; Ito, Koichi; Watanabe, Soichi
2007-01-01
The numerical dosimetry of pregnant women is an important issue in electromagnetic-field safety. However, an anatomically realistic whole-body pregnant-woman model for electromagnetic dosimetry has not been developed. Therefore, we have developed a high-resolution whole-body model of pregnant women. A new fetus model including inherent tissues of pregnant women was constructed on the basis of abdominal magnetic resonance imaging data of a 26-week-pregnant woman. The whole-body pregnant-woman model was developed by combining the fetus model and a nonpregnant-woman model that was developed previously. The developed model consists of about 7 million cubical voxels of 2 mm size and is segmented into 56 tissues and organs. This pregnant-woman model is the first completely anatomically realistic voxel model that includes a realistic fetus model and enables a numerical simulation of electromagnetic dosimetry up to the gigahertz band. In this paper, we also present the basic specific absorption rate characteristics of the pregnant-woman model exposed to vertically and horizontally polarized electromagnetic waves from 10 MHz to 2 GHz
Radiation of Electron in the Field of Plane Light Wave
International Nuclear Information System (INIS)
Zelinsky, A.; Drebot, I.V.; Grigorev, Yu.N.; Zvonareva, O.D.; Tatchyn, R.
2006-01-01
Results of integration of a Lorentz equation for a relativistic electron moving in the field of running, plane, linear polarized electromagnetic wave are presented in the paper. It is shown that electron velocities in the field of the wave are almost periodic functions of time. For calculations of angular spectrum of electron radiation intensity expansion of the electromagnetic field in a wave zone into generalized Fourier series was used. Expressions for the radiation intensity spectrum are presented in the paper. Derived results are illustrated for electron and laser beam parameters of NSC KIPT X-ray generator NESTOR. It is shown that for low intensity of the interacting electromagnetic wave the results of energy and angular spectrum calculations in the frame of classical electrodynamics completely coincide with calculation results produced using quantum electrodynamics. Simultaneously, derived expressions give possibilities to investigate dependence of energy and angular Compton radiation spectrum on phase of interaction and the interacting wave intensity
Polarization in free electron lasers
Energy Technology Data Exchange (ETDEWEB)
Papadichev, V.A. [Lebedev Physical Institute, Moscow (Russian Federation)
1995-12-31
Polarization of electromagnetic radiation is required very often in numerous scientific and industrial applications: studying of crystals, molecules and intermolecular interaction high-temperature superconductivity, semiconductors and their transitions, polymers and liquid crystals. Using polarized radiation allows to obtain important data (otherwise inaccessible) in astrophysics, meteorology and oceanology. It is promising in chemistry and biology for selective influence on definite parts of molecules in chain synthesis reactions, precise control of various processes at cell and subcell levels, genetic engineering etc. Though polarization methods are well elaborated in optics, they can fail in far-infrared, vacuum-ultraviolet and X-ray regions because of lack of suitable non-absorbing materials and damaging of optical elements at high specific power levels. Therefore, it is of some interest to analyse polarization of untreated FEL radiation obtained with various types of undulators, with and without axial magnetic field. The polarization is studied using solutions for electron orbits in various cases: plane or helical undulator with or without axial magnetic field, two plane undulators, a combination of right- and left-handed helical undulators with equal periods, but different field amplitudes. Some examples of how a desired polarization (elliptical circular or linear) can be obtained or changed quickly, which is necessary in many experiments, are given.
Directory of Open Access Journals (Sweden)
Y. Ida
2008-07-01
Full Text Available An improved analysis of polarization (as the ratio of vertical magnetic field component to the horizontal one has been developed, and applied to the approximately four years data (from 1 March 2003 to 31 December 2006 observed at Kashi station in China. It is concluded that the polarization ratio has exhibited an apparent increase only just before the earthquake on 1 September 2003 (magnitude = 6.1 and epicentral distance of 116 km.
Magneto-optical Kerr effect studies with classical electromagnetic theory
Ma, Rui-Can; Gao, Ling-Ling; Zhang, Ting; Jin, Yi
2017-08-01
Employing the basic law of electromagnetic wave propagation with the constitutive relation of ideal ferromagnetic medium, the magneto-optical Kerr effect of linearly polarized plane wave on the surface of ideal ferromagnetic medium is studied. We also discuss the change law of the Kerr rotation angle with the incident angle and magnetic-field strength in detail, which can provide crucial information for the applications of the magneto-optical Kerr effect in many fields.
Neutral fermion possessing by electric and magnetic moments in external electromagnetic field
International Nuclear Information System (INIS)
Khalilov, V.R.
2001-01-01
It is shown that in 2+1 dimensions the Dirac equations for a neutral fermion, specified by electric and magnetic dipole moments, is reduced in the electromagnetic field to the Dirac equation for the charged fermion in the external field, characterized by some pseudovector potential. The neutral fermion charge is determined by its dipole moments. The exact solution is found for the Dirac equation for the massive neutral fermion with magnetic and electric dipole moments in the external electromagnetic plane-wave field. The problem on the neutral fermion vacuum polarization in presence of external electromagnetic fields is considered [ru
Energy Technology Data Exchange (ETDEWEB)
campione, Salvatore [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Warne, Larry K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schiek, Richard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Basilio, Lorena I. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2017-09-01
This report details the modeling results for the response of a finite-length dissipative conductor interacting with a conducting ground to the Bell Labs electromagnetic pulse excitation. We use both a frequency-domain and a time-domain method based on transmission line theory through a code we call ATLOG - Analytic Transmission Line Over Ground. Results are compared to the circuit simulator Xyce for selected cases. Intentionally Left Blank
Radiation and propagation of electromagnetic waves
Tyras, George; Declaris, Nicholas
1969-01-01
Radiation and Propagation of Electromagnetic Waves serves as a text in electrical engineering or electrophysics. The book discusses the electromagnetic theory; plane electromagnetic waves in homogenous isotropic and anisotropic media; and plane electromagnetic waves in inhomogenous stratified media. The text also describes the spectral representation of elementary electromagnetic sources; the field of a dipole in a stratified medium; and radiation in anisotropic plasma. The properties and the procedures of Green's function method of solution, axial currents, as well as cylindrical boundaries a
Energy Technology Data Exchange (ETDEWEB)
Mitri, F.G., E-mail: F.G.Mitri@ieee.org [Chevron, Area 52 Technology–ETC, 5 Bisbee Ct., Santa Fe, NM 87508 (United States); Li, R.X., E-mail: rxli@mail.xidian.edu.cn [School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071 (China); Collaborative Innovation Center of Information Sensing and Understanding, Xidian University, Xi’an 710071 (China); Guo, L.X. [School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071 (China); Collaborative Innovation Center of Information Sensing and Understanding, Xidian University, Xi’an 710071 (China); Ding, C.Y. [School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071 (China)
2015-10-15
A complete description of vector Bessel (vortex) beams in the context of the generalized Lorenz–Mie theory (GLMT) for the electromagnetic (EM) resonance scattering by a dielectric sphere is presented, using the method of separation of variables and the subtraction of a non-resonant background (corresponding to a perfectly conducting sphere of the same size) from the standard Mie scattering coefficients. Unlike the conventional results of standard optical radiation, the resonance scattering of a dielectric sphere in air in the field of EM Bessel beams is examined and demonstrated with particular emphasis on the EM field’s polarization and beam order (or topological charge). Linear, circular, radial, azimuthal polarizations as well as unpolarized Bessel vortex beams are considered. The conditions required for the resonance scattering are analyzed, stemming from the vectorial description of the EM field using the angular spectrum decomposition, the derivation of the beam-shape coefficients (BSCs) using the integral localized approximation (ILA) and Neumann–Graf’s addition theorem, and the determination of the scattering coefficients of the sphere using Debye series. In contrast with the standard scattering theory, the resonance method presented here allows the quantitative description of the scattering using Debye series by separating diffraction effects from the external and internal reflections from the sphere. Furthermore, the analysis is extended to include rainbow formation in Bessel beams and the derivation of a generalized formula for the deviation angle of high-order rainbows. Potential applications for this analysis include Bessel beam-based laser imaging spectroscopy, atom cooling and quantum optics, electromagnetic instrumentation and profilometry, optical tweezers and tractor beams, to name a few emerging areas of research.
International Nuclear Information System (INIS)
Skoblin, A.A.
1994-01-01
Free nonrelativistic electrons in both a static magnetic field and an electromagnetic wave are considered. A plane-polarized wave propagates along a magnetic field, its frequency is close to the electron rotation frequency in a magnetic field. Electron spin is taken into account. An electron quasi energy spectrum and steady states (quasi energy states) are constructed. 6 refs
A differentiated plane wave: its passage through a slab
International Nuclear Information System (INIS)
Hannay, J H; Nye, J F
2013-01-01
Differentiating a monochromatic uniform plane electromagnetic wavefield with respect to its direction produces, from a field that is completely lacking in localized specific features, one that contains a straight vortex-like line, a ‘C-line’ of defined circular polarization. There is also a second separate C-line of opposite handedness; indeed, in a sense, a straight line of every polarization is realized. Because of its primitive construction it is analytically simple to study the passage of a differentiated wave obliquely through a plane interface into a medium of different refractive index, to trace its C-line. This was done in an earlier paper. Here we extend the method to passage through a parallel-sided transparent slab. There are multiple reflections within the slab, as in a Fabry–Pérot interferometer. The exiting wave, as a single differentiated plane wave, has a straight oblique C-line. Inside the slab, and in front of it, there is wave interference. The result is a coiled, helix-like, C-line in front of the slab and another inside it. The two coils wrap around separate hyperboloids of one sheet, like cooling towers. The emerging straight C-line is shifted (with respect to a C-line in a notional undisturbed incident plane wave) both in the plane of incidence and transversely to it, and the second C-line behaves similarly. The analysis is exact and could be extended in a straightforward way to a general stratified medium. (paper)
Electromagnetic Fields at the Surface of Human-Body Cylinders
DEFF Research Database (Denmark)
Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper
2016-01-01
The electromagnetic fields around an infinitely long cylinder with different material parameters are analyzed. The cylinder is modeled as muscle, skin, fat, and perfect electric conductor respectively. The cylinder is illuminated by a plane wave incident from different angles and with both...... transverse electric and transverse magnetic polarization. The results show that the material assumption when modeling the human body as a homogeneous material is very important. Furthermore, it is shown that one assumption might lead to higher fields for a specific polarization, angle of incidence...
Precessing deuteron polarization
International Nuclear Information System (INIS)
Sitnik, I.M.; Volkov, V.I.; Kirillov, D.A.; Piskunov, N.M.; Plis, Yu.A.
2002-01-01
The feasibility of the acceleration in the Nuclotron of deuterons polarized in the horizontal plane is considered. This horizontal polarization is named precessing polarization. The effects of the main magnetic field and synchrotron oscillations are included. The precessing polarization is supposed to be used in studying the polarization parameters of the elastic dp back-scattering and other experiments
York, Timothy; Powell, Samuel B; Gao, Shengkui; Kahan, Lindsey; Charanya, Tauseef; Saha, Debajit; Roberts, Nicholas W; Cronin, Thomas W; Marshall, Justin; Achilefu, Samuel; Lake, Spencer P; Raman, Baranidharan; Gruev, Viktor
2014-10-01
In this paper, we present recent work on bioinspired polarization imaging sensors and their applications in biomedicine. In particular, we focus on three different aspects of these sensors. First, we describe the electro-optical challenges in realizing a bioinspired polarization imager, and in particular, we provide a detailed description of a recent low-power complementary metal-oxide-semiconductor (CMOS) polarization imager. Second, we focus on signal processing algorithms tailored for this new class of bioinspired polarization imaging sensors, such as calibration and interpolation. Third, the emergence of these sensors has enabled rapid progress in characterizing polarization signals and environmental parameters in nature, as well as several biomedical areas, such as label-free optical neural recording, dynamic tissue strength analysis, and early diagnosis of flat cancerous lesions in a murine colorectal tumor model. We highlight results obtained from these three areas and discuss future applications for these sensors.
Electromagnetic pulses at the boundary of a nonlinear plasma
International Nuclear Information System (INIS)
Satorius, E.H.
1975-01-01
An investigation was made of the behavior of strong electromagnetic pulses at the boundary of a nonlinear, cold, collisionless, and uniform plasma. The nonlinearity considered here is due to the nonlinear terms in the fluid equation which is used to describe the plasma. Two cases are studied. First, the case where there is a voltage pulse applied across the plane boundary of a semi-infinite, nonlinear plasma. Two different voltage pulses are considered, i.e., a delta function pulse and a suddenly turned-on sinusoidal pulse. The resulting electromagnetic fields propagating in the nonlinear plasma are found in this case. In the second case, the reflection of incident E-polarized and H-polarized, electromagnetic pulses at various angles of incidence from a nonlinear, semi-infinite plasma are considered. Again, two forms of incident pulses are considered: a delta function pulse and a suddenly turned-on sinusoidal pulse. In case two, the reflected electromagnetic fields are found. In both cases, the method used for finding the fields is to first solve the fluid equation (which describes the plasma) for the nonlinear conduction current in terms of the electric field using a perturbation method (since the nonlinear effects are assumed to be small). Next, this current is substituted into Maxwell's equations, and finally the electromagnetic fields which satisfy the boundary conditions are found. (U.S.)
Chichibu, Shigefusa F; Kojima, Kazunobu; Uedono, Akira; Sato, Yoshitaka
2017-02-01
Planar vacuum-fluorescent-display devices emitting polarized UV-C, blue, and green light are demonstrated using immiscible Al 1- x In x N nanostructures grown in nonpolar m-directions. Despite the presence of high concentration of nonradiative recombination centers, the Al 1- x In x N nanostructures emit polarized light with the luminescence lifetimes of 22-32 ps at 300 K. This defect-resistant radiative performance suggests supernormal localized characteristics of electron-hole pairs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Energy Technology Data Exchange (ETDEWEB)
Nicholl, M.; Berger, E.; Kasen, D.; Metzger, B. D.; Elias, J.; Briceño, C.; Alexander, K. D.; Blanchard, P. K.; Chornock, R.; Cowperthwaite, P. S.; Eftekhari, T.; Fong, W.; Margutti, R.; Villar, V. A.; Williams, P. K. G.; Brown, W.; Annis, J.; Bahramian, A.; Brout, D.; Brown, D. A.; Chen, H. -Y.; Clemens, J. C.; Dennihy, E.; Dunlap, B.; Holz, D. E.; Marchesini, E.; Massaro, F.; Moskowitz, N.; Pelisoli, I.; Rest, A.; Ricci, F.; Sako, M.; Soares-Santos, M.; Strader, J.
2017-10-16
We present optical and ultraviolet spectra of the first electromagnetic counterpart to a gravitational wave (GW) source, the binary neutron star merger GW170817. Spectra were obtained nightly between 1.5 and 9.5 days post-merger, using the SOAR and Magellan telescopes; the UV spectrum was obtained with the \\textit{Hubble Space Telescope} at 5.5 days. Our data reveal a rapidly-fading blue component ($T\\approx5500$ K at 1.5 days) that quickly reddens; spectra later than $\\gtrsim 4.5$ days peak beyond the optical regime. The spectra are mostly featureless, although we identify a possible weak emission line at $\\sim 7900$ \\AA\\ at $t\\lesssim 4.5$ days. The colours, rapid evolution and featureless spectrum are consistent with a "blue" kilonova from polar ejecta comprised mainly of light $r$-process nuclei with atomic mass number $A\\lesssim 140$. This indicates a sight-line within $\\theta_{\\rm obs}\\lesssim 45^{\\circ}$ of the orbital axis. Comparison to models suggests $\\sim0.03$ M$_\\odot$ of blue ejecta, with a velocity of $\\sim 0.3c$. The required lanthanide fraction is $\\sim 10^{-4}$, but this drops to $<10^{-5}$ in the outermost ejecta. The large velocities point to a dynamical origin, rather than a disk wind, for this blue component, suggesting that both binary constituents are neutron stars (as opposed to a binary consisting of a neutron star and a black hole). For dynamical ejecta, the high mass favors a small neutron star radius of $\\lesssim 12$ km. This mass also supports the idea that neutron star mergers are a major contributor to $r$-process nucleosynthesis.
The inverse problem for the refractometry diagnostics of electromagnetic turbulence in plasma
International Nuclear Information System (INIS)
Lazarian, A.
1994-01-01
Turbulence is an important property of laboratory plasmas. A number of relevant diagnostics are based on the interaction of an electromagnetic beam with plasma. Here we discuss a refractometry technique, where information on plasma properties is obtained by probing plasma with a plane polarized electromagnetic beam. It is shown that the problem of recovering statistical properties of plasma turbulence from the line integrated data can be solved uniquely using a realistic model of plasma. Analytical expressions relating statistics of both the random density and random magnetic fields to the measured statistics have been found. This information is of importance in studies of plasma turbulence. (author)
2007-10-08
excitation of microwave spin waves.3,10,11 The analytical theory of spin-wave excitation in magnetic nanocontacts by spin-polarized current performed...linear theory ,3 the propagating spin- wave mode excited at the threshold is a cylindrical spin- wave with the wave vector kL=1.2/Rc and frequency L... Oersted magnetic field, and/or by any other small interaction, neglected in the micromagnetic model. To make the excitation of subcritical modes12,15
Electromagnetic radiation optimum neutralizer
International Nuclear Information System (INIS)
Smirnov, Igor
2002-01-01
This particular article relates to subtle electrical effects, and provides some evidence of a fundamental nature on how subtle low frequency electromagnetic fields might be utilized to protect human body against harmful effects of high frequencies electromagnetic radiation. I have focused my efforts on definite polar polymer compound named EMRON which is patented in the USA. This polar polymer compound can be excited by external high frequencies electromagnetic fields to generate subtle low frequency oscillations that are beneficial for cellular life structures. This concept is based on the possibility of existence of resonance phenomenon between polar polymers and biopolymers such as proteins, nucleic acids, lipids, etc. Low frequency patterns generated by defined polar polymer compound can interact with biostructures and transmit the signals that support and improve cellular functions in the body. The mechanism of this process was confirmed by number of studies. The animal (including human) brain is affected by electromagnetic waves to the extent that production of Alpha or Theta waves can be directly induced into brain by carrying an ELF (extremely low frequency, 5-12 Hz) signal on a microwave carrier frequency. EMRON does not reduce the power of electromagnetic fields. It 'shields' the cellular structures of the body against the harmful effects of EMR. The radiation is still entering the body but the neutralizing effect of EMRON renders the radiation harmless
International Nuclear Information System (INIS)
Gomez R, F.; Ondarza R, R.
2004-01-01
An analytic model is presented for the description of the motion of a charged particle in the interaction of an elliptically electromagnetic pulse polarized propagating along a static and homogeneous external magnetic field in a plasma starting from the force equation. The method allows to express the solution in terms of the invariant phase, obtaining differential equations for the trajectory of the accelerated particle by means of an electromagnetic pulse of arbitrary and modulated width by an encircling Gaussian. The numerical solutions reported in this work can find varied applications, for example in the physics of the interaction laser-plasma, in the acceleration of particles, in hot plasma and in radioactive effects. (Author)
International Nuclear Information System (INIS)
Gomez R, F.; Ondarza R, R.
2004-01-01
An analytical model for the description of the movement of a charged particle in the interaction of an electromagnetic pulse elliptically polarized propagating along of a static and homogeneous external magnetic field in a plasma starting from the force equation is presented. The method allows to express the solution in terms of the invariant phase, obtaining differential equations for the trajectory of the accelerated particle by means of an electromagnetic pulse of arbitrary amplitude and modulated by an encircling Gaussian. The numerical solutions reported in this work can find varied applications, for example in the physics of the interaction laser-plasma, in the acceleration of particles, in hot plasma and in radiative effects. (Author)
Jing, Long; Huang, Ping; Zhu, Huarui; Gao, Xueyun
2013-01-28
First-principles calculations (generalized gradient approximation, density functional therory (DFT) with dispersion corrections, and DFT plus local atomic potential) are carried out on the stability and electronic structures of superlattice configurations of nitrophenyl diazonium functionalized graphene with different coverage. In the calculations, the stabilities of these structures are strengthened significantly since van der Waals interactions between nitrophenyl groups are taken into account. Furthermore, spin-polarized and wider-bandgap electronic structures are obtained when the nitrophenyl groups break the sublattice symmetry of the graphene. The unpaired quasi-localized p electrons are responsible for this itinerant magnetism. The results provide a novel approach to tune graphene's electronic structures as well as to form ferromagnetic semiconductive graphene. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
To the theory of quantum processes in the field of an intense electromagnetic wave
International Nuclear Information System (INIS)
Bajer, V.N.; Katkov, V.M.; Mil'shtejn, A.I.; Strakhovenko, V.M.
1975-01-01
The operator diagram technique, developed earlier for considering phenomena in a homogeneous external field, is applied to processes occurring in a plane electromagnetic wave field. Calculations are carried out on the basis of a specific technique of ''entangling'' of operator expressions. The mass operator of scalar and spinor particles determined by a double integral is found in the field of an elliptically polarized wave of a general type. Imaginary part of the operator presents a new concept of the full probability of a particle emission in a wave field. Polarization effects are analyzed for spinor particles
Rivera, Andrea
2016-01-01
From moving ramps to playground slides, inclined planes are at work all over in our world today. Learn all about them in five easy-to-read chapters. Vibrant, full-color photos, bolded glossary words, and a key stats section let readers zoom in even deeper. Aligned to Common Core Standards and correlated to state standards. Abdo Zoom is a division of ABDO.
International Nuclear Information System (INIS)
Heckler, A.; Blaer, A.; Kaaret, P.; Novick, R.
1989-01-01
An experimental study of the polarization dependence of the photoelectric effect in cesium iodide in the soft X-ray band was started (Heckler et al., 1989). At a grazing angle of 10 degrees and a photon energy of 2.6 keV, it is found that the photoelectric yield from a thin layer of evaporated cesium iodide varies by 12.4 percent as the polarization vector of the incident X-ray beam is rotated about the line-of-sight. The rotation angle corresponding to the maximum photoyield is displaced by 16 degrees from the normal to the photocathode. This modulation and phase shift are in good agreement with the results recently reported by Fraser, et al. (1989) It is shown that a focal plane stellar X-ray polarimeter based on this photoelectric effect will be substantially more efficient than convential X-ray polarimeters such as those based on either Bragg reflection or scattering from low atomic number targets. 7 refs
Electromagnetic waves in stratified media
Wait, James R; Fock, V A; Wait, J R
2013-01-01
International Series of Monographs in Electromagnetic Waves, Volume 3: Electromagnetic Waves in Stratified Media provides information pertinent to the electromagnetic waves in media whose properties differ in one particular direction. This book discusses the important feature of the waves that enables communications at global distances. Organized into 13 chapters, this volume begins with an overview of the general analysis for the electromagnetic response of a plane stratified medium comprising of any number of parallel homogeneous layers. This text then explains the reflection of electromagne
Coherent hybrid electromagnetic field imaging
Cooke, Bradly J [Jemez Springs, NM; Guenther, David C [Los Alamos, NM
2008-08-26
An apparatus and corresponding method for coherent hybrid electromagnetic field imaging of a target, where an energy source is used to generate a propagating electromagnetic beam, an electromagnetic beam splitting means to split the beam into two or more coherently matched beams of about equal amplitude, and where the spatial and temporal self-coherence between each two or more coherently matched beams is preserved. Two or more differential modulation means are employed to modulate each two or more coherently matched beams with a time-varying polarization, frequency, phase, and amplitude signal. An electromagnetic beam combining means is used to coherently combine said two or more coherently matched beams into a coherent electromagnetic beam. One or more electromagnetic beam controlling means are used for collimating, guiding, or focusing the coherent electromagnetic beam. One or more apertures are used for transmitting and receiving the coherent electromagnetic beam to and from the target. A receiver is used that is capable of square-law detection of the coherent electromagnetic beam. A waveform generator is used that is capable of generation and control of time-varying polarization, frequency, phase, or amplitude modulation waveforms and sequences. A means of synchronizing time varying waveform is used between the energy source and the receiver. Finally, a means of displaying the images created by the interaction of the coherent electromagnetic beam with target is employed.
DEFF Research Database (Denmark)
This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis......, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc....
Determination of electromagnetic absorption parameters by reflection measurements
International Nuclear Information System (INIS)
Vittitoe, C.N.
1975-09-01
The method described is for determining the electromagnetic absorption parameters of a material by measuring the optical reflection from a thick sample. With linearly polarized incident light (both perpendicular to and parallel to the plane of incidence), the ratio of the reflected intensities at three or more angles of incidence offers promise for determining the complex index of refraction of a material for a broad range of parameter values. The method may be applicable to molten materials, such as UO 2 , where high temperatures cause corrosion and containment difficulties. A method is given for extending the data to neighboring frequencies. Use of the method was successful for all portions of the complex index of refraction plane except for small values of the extinction coefficient
International Nuclear Information System (INIS)
Zhou Guo-Quan
2011-01-01
Based on the vectorial structure of an electromagnetic wave, the analytical and concise expressions for the TE and TM terms of a vectorial plane wave diffracted by a circular aperture are derived in the far-field. The expressions of the energy flux distributions of the TE term, the TM term and the diffracted plane wave are also presented. The ratios of the power of the TE and TM terms to that of the diffracted plane wave are examined in the far-field. In addition, the far-field divergence angles of the TE term, the TM term and the diffracted plane wave, which are related to the energy flux distribution, are investigated. The different energy flux distributions of the TE and TM terms result in the discrepancy of their divergence angles. The influences of the linearly polarized angle and the radius of the circular aperture on the far-field divergence angles of the TE term, the TM term and the diffracted plane wave are discussed in detail. This research may promote the recognition of the optical propagation through a circular aperture. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Forgács, Péter; Lukács, Árpád; Romańczukiewicz, Tomasz
2013-12-01
It is shown that in a large class of systems, plane waves act as tractor beams: i.e., an incident plane wave can exert a pulling force on the scatterer. The underlying physical mechanism for the pulling force is due to the sufficiently strong scattering of the incoming wave into another mode carrying more momentum, in which case excess momentum is created behind the scatterer. This tractor beam or negative radiation pressure (NRP) effect, is found to be generic in systems with multiple scattering channels. In a birefringent medium, electromagnetic plane waves incident on a thin plate exert NRP of the same order of magnitude as optical radiation pressure, while in artificial dielectrics (metamaterials), the magnitude of NRP can even be macroscopic. In two dimensions, we study various scattering situations on vortices, and NRP is shown to occur by the scattering of heavy baryons into light leptons off cosmic strings, and by neutron scattering off vortices in the XY model.
Explaining polarization reversals in STEREO wave data
Breneman, A.; Cattell, C.; Wygant, J.; Kersten, K.; Wilson, L. B., III; Dai, L.; Colpitts, C.; Kellogg, P. J.; Goetz, K.; Paradise, A.
2012-04-01
Recently, Breneman et al. (2011) reported observations of large amplitude lightning and transmitter whistler mode waves from two STEREO passes through the inner radiation belt (L plane transverse to the magnetic field showed that the transmitter waves underwent periodic polarization reversals. Specifically, their polarization would cycle through a pattern of right-hand to linear to left-hand polarization at a rate of roughly 200 Hz. The lightning whistlers were observed to be left-hand polarized at frequencies greater than the lower hybrid frequency and less than the transmitter frequency (21.4 kHz) and right-hand polarized otherwise. Only right-hand polarized waves in the inner radiation belt should exist in the frequency range of the whistler mode and these reversals were not explained in the previous paper. We show, with a combination of observations and simulated wave superposition, that these polarization reversals are due to the beating of an incident electromagnetic whistler mode wave at 21.4 kHz and linearly polarized, symmetric lower hybrid sidebands Doppler-shifted from the incident wave by ±200 Hz. The existence of the lower hybrid waves is consistent with the parametric decay mechanism of Lee and Kuo (1984) whereby an incident whistler mode wave decays into symmetric, short wavelength lower hybrid waves and a purely growing (zero-frequency) mode. Like the lower hybrid waves, the purely growing mode is Doppler-shifted by ˜200 Hz as observed on STEREO. This decay mechanism in the upper ionosphere has been previously reported at equatorial latitudes and is thought to have a direct connection with explosive spread F enhancements. As such it may represent another dissipation mechanism of VLF wave energy in the ionosphere and may help to explain a deficit of observed lightning and transmitter energy in the inner radiation belts as reported by Starks et al. (2008).
International Nuclear Information System (INIS)
Accioly, A.J.; Vaidya, A.N.; Som, M.M.
1983-01-01
The problem of static electromagnetic field admitting a time-like and two space-like Killing vectors is completely solved. The solutions contain plane-symmetric solution as a special case. The solutions can be transformed into solutions describing the gravitational field of a charge line-mass by suitably introducing weyl's canonical coordinates. Further, these solutions are true generalizations of Kasner solutions. (Author) [pt
Aircraft Electromagnetic Compatibility.
1987-06-01
report) 20. Securty Clasif . (of this page) 21. No. of Pages 22. Price FORM 00 For ale by the National Technical Information Service, Springfield...34 the plane with the steering column having steel cable strung from the column to hydraulic actuators which then amplify the force and operate control...surfaces (figure 2.1-14). The engine throttle is operated by a steel cable. A steel cable does not recognize electromagnetic interference. Navigation
Meziane, Belkacem
2018-03-01
The main intent of this paper is to demonstrate that the theoretical formulations of the reflectance and transmittance characteristics of an initially free quantum particle, heading towards some restricted region of space, inside which it undergoes the effect of an electric-potential-barrier, are isomorphic to those of an incident plane- and linearly-polarized electromagnetic wave, which propagates towards and through a homogeneous dielectric slab.
Exact relativistic solution of disordered radiation with plane symmetry
International Nuclear Information System (INIS)
Fonseca Teixeira, A.F. da; Wolk, I.; Som, M.M.
1976-04-01
An exact solution of Einstein equations corresponding to an equilibrium distribution of disordered electromagnetic radiation with plane symmetry is obtained. This equilibrium is due solely to the gravitational and pressure effects inherent to the radiation. The distribution of radiation is found to be maximum and finite at the plane of symmetry, and to decrease monotonically in directions normal to this plane. The solution tends asymptotically to the static plane symmetric vacuum solution obtained by Levi-Civita. Timelike and null geodesics are discussed
Particle physics in intense electromagnetic fields
International Nuclear Information System (INIS)
Kurilin, A.V.
1999-01-01
The quantum field theory in the presence of classical background electromagnetic field is reviewed giving a pedagogical introduction to the Feynman-Furry method of describing non-perturbative interactions with very strong electromagnetic fields. A particular emphasis is given to the case of the plane-wave electromagnetic field for which the charged particles' wave functions and propagators are presented. Some general features of quantum processes proceeding in the intense electromagnetic background are argued. The possibilities of searching new physics through the investigations of quantum phenomena induced by a strong electromagnetic environment are also discussed
A primer on electromagnetic fields
Frezza, Fabrizio
2015-01-01
This book is a concise introduction to electromagnetics and electromagnetic fields that covers the aspects of most significance for engineering applications by means of a rigorous, analytical treatment. After an introduction to equations and basic theorems, topics of fundamental theoretical and applicative importance, including plane waves, transmission lines, waveguides, and Green's functions, are discussed in a deliberately general way. Care has been taken to ensure that the text is readily accessible and self-consistent, with conservation of the intermediate steps in the analytical derivations. The book offers the reader a clear, succinct course in basic electromagnetic theory. It will also be a useful lookup tool for students and designers.
Dynamical characteristics of an electromagnetic field under conditions of total reflection
Bekshaev, Aleksandr Ya
2018-04-01
The dynamical characteristics of electromagnetic fields include energy, momentum, angular momentum (spin) and helicity. We analyze their spatial distributions near the planar interface between two transparent and non-dispersive media, when the incident monochromatic plane wave with arbitrary polarization is totally reflected, and an evanescent wave is formed in the medium with lower optical density. Based on the recent arguments in favor of the Minkowski definition of the electromagnetic momentum in a material medium (Philbin 2011 Phys. Rev. A 83 013823; Philbin and Allanson 2012 86 055802; Bliokh et al 2017 Phys. Rev. Lett. 119 073901), we derive the explicit expressions for the dynamical characteristics in both media, with special attention to their behavior at the interface. In particular, the ‘extraordinary’ spin and momentum components orthogonal to the plane of incidence are described, and a canonical (spin-orbital) momentum decomposition is performed that contains no singular terms. The field energy, helicity, the spin momentum and orbital momentum components are everywhere regular but experience discontinuities at the interface; the spin components parallel to the interface appear to be continuous, which testifies to the consistency of the adopted Minkowski picture. The results supply a meaningful example of the electromagnetic momentum decomposition, with separation of spatial and polarization degrees of freedom, in inhomogeneous media, and can be used in engineering the structured fields designed for optical sorting, dispatching and micromanipulation.
Polarization fluctuations in stationary light beams
International Nuclear Information System (INIS)
Shevchenko, A.; Setaelae, T.; Kaivola, M.; Friberg, A.T.; Royal Institute of Technology , Department of Microelectronics and Applied Physics; Sweden)
2009-01-01
For stationary beams the degree of polarization contains only limited information on time dependent polarization. Two approaches towards assessing a beams polarization dynamics, one based on Poincare and the other on Jones vector formalism, are described leading to the notion of polarization time. Specific examples of partially temporally coherent electromagnetic beams are discussed. (Author)
Anisotropic conducting films for electromagnetic radiation applications
Cavallo, Francesca; Lagally, Max G.; Rojas-Delgado, Richard
2015-06-16
Electronic devices for the generation of electromagnetic radiation are provided. Also provided are methods for using the devices to generate electromagnetic radiation. The radiation sources include an anisotropic electrically conducting thin film that is characterized by a periodically varying charge carrier mobility in the plane of the film. The periodic variation in carrier mobility gives rise to a spatially varying electric field, which produces electromagnetic radiation as charged particles pass through the film.
2017-08-08
the band and for scan angles up to 60° from normal. The antenna efficiency and axial ratio degrade by 1 dB at some points near the edges of the band...Prescribed by ANSI Std. Z39-18 i Approved for public release; distribution is unlimited Table of Contents Section Page 1.0 Summary...51 6.4 Estimating Finite Polarizer Edge Effects
Electromagnetic scattering by two concentric spheres buried in a stratified material.
Frezza, F; Mangini, F; Tedeschi, N
2015-02-01
In this paper, a rigorous method to analyze the electromagnetic scattering of an elliptically polarized plane wave by two concentric spheres buried in a dielectric stratified medium is presented. The interaction of the electromagnetic radiation with the stratified material is taken into account by means of the transfer matrix approach, in this way we can consider the stratified medium as an effective single interface. All the electromagnetic fields are expanded in series of spherical vector harmonics. The transmitted field through the stratified medium is obtained by means of the effective transmission coefficient. This field is scattered by the two concentric spheres, and the scattered field interacts again with the stratified material. The scattered-reflected and scattered-transmitted fields by the layered medium are computed by exploiting the plane-wave spectrum of the scattered field, considering the reflection and transmission of each elementary plane wave by the effective interface. The boundary conditions imposition on the spheres' surfaces leads to a linear system that returns the unknown coefficients of the problem. A numerical code has been implemented to compute the field over all the space. In order to compute the scattered fields, a truncation criterion has been proposed for the numerical evaluation of the series. Finally, to validate the presented method, comparisons between the results of the proposed code and the results of simulations with a software based on the finite element method have been implemented, showing very good agreement.
Particle acceleration by electromagnetic pulses
International Nuclear Information System (INIS)
Lai, H.M.
1982-01-01
Particle interaction with plane electromagnetic pulses is studied. It is shown that particle acceleration by a wavy pulse, depending on the shape of the pulse, may not be small. Further, a diffusive-type particle acceleration by multiple weak pulses is described and discussed. (author)
Electromagnetic wave analogue of electronic diode
Shadrivov, Ilya V.; Powell, David A.; Kivshar, Yuri S.; Fedotov, Vassili A.; Zheludev, Nikolay I.
2010-01-01
An electronic diode is a nonlinear semiconductor circuit component that allows conduction of electrical current in one direction only. A component with similar functionality for electromagnetic waves, an electromagnetic isolator, is based on the Faraday effect of the polarization state rotation and is also a key component of optical and microwave systems. Here we demonstrate a chiral electromagnetic diode, which is a direct analogue of an electronic diode: its functionality is underpinned by ...
Scattering of light and other electromagnetic radiation
Kerker, Milton
1969-01-01
The Scattering of Light and Other Electromagnetic Radiation discusses the theory of electromagnetic scattering and describes some practical applications. The book reviews electromagnetic waves, optics, the interrelationships of main physical quantities and the physical concepts of optics, including Maxwell's equations, polarization, geometrical optics, interference, and diffraction. The text explains the Rayleigh2 theory of scattering by small dielectric spheres, the Bessel functions, and the Legendre functions. The author also explains how the scattering functions for a homogenous sphere chan
[Review] Polarization and Polarimetry
Trippe, Sascha
2014-02-01
Polarization is a basic property of light and is fundamentally linked to the internal geometry of a source of radiation. Polarimetry complements photometric, spectroscopic, and imaging analyses of sources of radiation and has made possible multiple astrophysical discoveries. In this article I review (i) the physical basics of polarization: electromagnetic waves, photons, and parameterizations; (ii) astrophysical sources of polarization: scattering, synchrotron radiation, active media, and the Zeeman, Goldreich-Kylafis, and Hanle effects, as well as interactions between polarization and matter (like birefringence, Faraday rotation, or the Chandrasekhar-Fermi effect); (iii) observational methodology: on-sky geometry, influence of atmosphere and instrumental polarization, polarization statistics, and observational techniques for radio, optical, and X/γ wavelengths; and (iv) science cases for astronomical polarimetry: solar and stellar physics, planetary system bodies, interstellar matter, astrobiology, astronomical masers, pulsars, galactic magnetic fields, gamma-ray bursts, active galactic nuclei, and cosmic microwave background radiation.
International Nuclear Information System (INIS)
Yamashita, H.; Marinova, I.; Cingoski, V.
2002-01-01
These proceedings contain papers relating to the 3rd Japanese-Bulgarian-Macedonian Joint Seminar on Applied Electromagnetics. Included are the following groups: Numerical Methods I; Electrical and Mechanical System Analysis and Simulations; Inverse Problems and Optimizations; Software Methodology; Numerical Methods II; Applied Electromagnetics
Milson, James L.
1990-01-01
Three activities involving electromagnetism are presented. Discussed are investigations involving the construction of an electromagnet, the effect of the number of turns of wire in the magnet, and the effect of the number of batteries in the circuit. Extension activities are suggested. (CW)
Bosanac, Slobodan Danko
2016-01-01
This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.
Measurement of inclusive quasielastic scattering of polarized electrons from polarized 3He
International Nuclear Information System (INIS)
Woodward, C.E.; Beise, E.J.; Belz, J.E.; Carr, R.W.; Filippone, B.W.; Lorenzon, W.B.; McKeown, R.D.; Mueller, B.; O'Neill, T.G.; Dodson, G.; Dow, K.; Farkhondeh, M.; Kowalski, S.; Lee, K.; Makins, N.; Milner, R.; Thompson, A.; Tieger, D.; van den Brand, J.; Young, A.; Yu, X.; Zumbro, J.
1990-01-01
We report a measurement of the asymmetry in spin-dependent quasielastic scattering of longitudinally polarized electrons from a polarized 3 He gas target. This measurement represents the first demonstration of a new method for studying electromagnetic nuclear structure: the scattering of polarized electrons from a polarized nuclear target. The measured asymmetry is in good agreement with a Faddeev calculation and supports the picture of spin-dependent quasielastic scattering from polarized 3 He as predominantly scattering from a polarized neutron
Polarimetric purity and the concept of degree of polarization
Gil, José J.; Norrman, Andreas; Friberg, Ari T.; Setälä, Tero
2018-02-01
The concept of degree of polarization for electromagnetic waves, in its general three-dimensional version, is revisited in the light of the implications of the recent findings on the structure of polarimetric purity and of the existence of nonregular states of polarization [J. J. Gil et al., Phys Rev. A 95, 053856 (2017), 10.1103/PhysRevA.95.053856]. From the analysis of the characteristic decomposition of a polarization matrix R into an incoherent convex combination of (1) a pure state Rp, (2) a middle state Rm given by an equiprobable mixture of two eigenstates of R, and (3) a fully unpolarized state Ru -3 D, it is found that, in general, Rm exhibits nonzero circular and linear degrees of polarization. Therefore, the degrees of linear and circular polarization of R cannot always be assigned to the single totally polarized component Rp. It is shown that the parameter P3 D proposed formerly by Samson [J. C. Samson, Geophys. J. R. Astron. Soc. 34, 403 (1973), 10.1111/j.1365-246X.1973.tb02404.x] takes into account, in a proper and objective form, all the contributions to polarimetric purity, namely, the contributions to the linear and circular degrees of polarization of R as well as to the stability of the plane containing its polarization ellipse. Consequently, P3 D constitutes a natural representative of the degree of polarimetric purity. Some implications for the common convention for the concept of two-dimensional degree of polarization are also analyzed and discussed.
Improved Electromagnetic Brake
Martin, Toby B.
2004-01-01
A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may
Thomas, David T; Hartnett, James P; Hughes, William F
1973-01-01
The applications involving electromagnetic fields are so pervasive that it is difficult to estimate their contribution to the industrial output: generation of electricity, power transmission lines, electric motors, actuators, relays, radio, TV and microwave transmission and reception, magnetic storage, and even the mundane little magnet used to hold a paper note on the refrigerator are all electromagnetic in nature. One would be hard pressed to find a device that works without relaying on any electromagnetic principle or effect. This text provides a good theoretical understanding of the electromagnetic field equations but also treats a large number of applications. In fact, no topic is presented unless it is directly applicable to engineering design or unless it is needed for the understanding of another topic. In electrostatics, for example, the text includes discussions of photocopying, ink-jet printing, electrostatic separation and deposition, sandpaper production, paint spraying, and powder coating. In ma...
DEFF Research Database (Denmark)
Cermak, Daniel; Okutsu, Ayaka; Jørgensen, Stina Marie Hasse
2015-01-01
Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015.......Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015....
Phenomenology of the deuteron electromagnetic form factors
International Nuclear Information System (INIS)
David Abbott; Abdellah Ahmidouch; H. Anklin; J. Arvieux; James P. Ball; Shelton Beedoe; Elizabeth Beise; Louis Bimbot; Werner Boeglin; Herbert Breuer; Roger Carlini; Nicholas Chant; Samuel Danagoulian; K. Dow; Jean-Eric Ducret; Jim Dunne; Lars Ewell; L. Eyraud; C. Furget; Michel Garcon; Ron Gilman; Charles Glashausser; Paul Gueye; Kenneth Gustafsson; Kawtar Hafidi; A. Honegger; J. Jourdan; Serge Kox; Gerfried Kumbartzki; L. Lu; Allison Lung; Pete Markowitz; Justin McIntyre; David Meekins; F. Merchez; Joseph Mitchell; R. Mohring; S. Mtingwa; H. Mrktchyan; D. Pitz; Liming Qin; Ronald Ransome; J.-S. R'eal; Philip Roos; Paul Rutt; Reyad Sawafta; Stepan Stepanyan; Raphael Tieulent; E. Tomasi-Gustafsson; William Turchinetz; K. Vansyoc; J. Volmer; E. Voutier; Claude Williamson; Stephen Wood; Chen Yan; Jianguo Zhao; W. Zhao
2000-01-01
A rigorous extraction of the deuteron charge form factors from tensor polarization data in elastic electron-deuteron scattering, at given values of the 4-momentum transfer, is presented. Then the world data for elastic electron-deuteron scattering is used to parameterize, in three different ways, the three electromagnetic form factors of the deuteron in the 4-momentum transfer range 0-7 fm. This procedure is made possible with the advent of recent polarization measurements. The parameterizations allow a phenomenological characterization of the deuteron electromagnetic structure. They can be used to remove ambiguities in the form factors extraction from future polarization data
Three-dimensional electromagnetic solitary waves in an underdense plasma in PIC simulations
International Nuclear Information System (INIS)
Bulanov, Sergei; Esirkepov, Timur; Nishihara, Katsunobu; Pegoraro, Francesco
2002-01-01
A three-dimensional sub-cycle relativistic electromagnetic soliton has been observed for the first time in a 3D Particle-in-Cell simulation of the propagation of an intense short laser pulse in an underdense plasma. The structure of the 3D soliton is identified. It resembles an oscillating electric dipole and has a strong charge separation and toroidal magnetic field component. We call this structure a TM-soliton (transverse magnetic). The 3D TM-soliton resembles a 2D P-soliton in the plane of electric field polarization, and a 2D S-soliton in the perpendicular plane. The core of the soliton is positively charged on average in time, and this results in its Coulomb explosion and in ion heating. Then the soliton evolves into a post-soliton, which is a slowly expanding quasi-neutral cavity in the plasma
Particle Production in Strong Electromagnetic Fields in Relativistic Heavy-Ion Collisions
Directory of Open Access Journals (Sweden)
Kirill Tuchin
2013-01-01
Full Text Available I review the origin and properties of electromagnetic fields produced in heavy-ion collisions. The field strength immediately after a collision is proportional to the collision energy and reaches ~mπ2 at RHIC and ~10mπ2 at LHC. I demonstrate by explicit analytical calculation that after dropping by about one-two orders of magnitude during the first fm/c of plasma expansion, it freezes out and lasts for as long as quark-gluon plasma lives as a consequence of finite electrical conductivity of the plasma. Magnetic field breaks spherical symmetry in the direction perpendicular to the reaction plane, and therefore all kinetic coefficients are anisotropic. I examine viscosity of QGP and show that magnetic field induces azimuthal anisotropy on plasma flow even in spherically symmetric geometry. Very strong electromagnetic field has an important impact on particle production. I discuss the problem of energy loss and polarization of fast fermions due to synchrotron radiation, consider photon decay induced by magnetic field, elucidate J/ψ dissociation via Lorentz ionization mechanism, and examine electromagnetic radiation by plasma. I conclude that all processes in QGP are affected by strong electromagnetic field and call for experimental investigation.
Topologically protected edge states for out-of-plane and in-plane bulk elastic waves
Huo, Shao-Yong; Chen, Jiu-Jiu; Huang, Hong-Bo
2018-04-01
Topological phononic insulators (TPnIs) show promise for application in the manipulation of acoustic waves for the design of low-loss transmission and perfectly integrated communication devices. Since solid phononic crystals exist as a transverse polarization mode and a mixed longitudinal-transverse polarization mode, the realization of topological edge states for both out-of-plane and in-plane bulk elastic waves is desirable to enhance the controllability of the edge waves in solid systems. In this paper, a two-dimensional (2D) solid/solid hexagonal-latticed phononic system that simultaneously supports the topologically protected edge states for out-of-plane and in-plane bulk elastic waves is investigated. Firstly, two pairs of two-fold Dirac cones, respectively corresponding to the out-of-plane and in-plane waves, are obtained at the same frequency by tuning the crystal parameters. Then, a strategy of zone folding is invoked to form double Dirac cones. By shrinking and expanding the steel scatterer, the lattice symmetry is broken, and band inversions induced, giving rise to an intriguing topological phase transition. Finally, the topologically protected edge states for both out-of-plane and in-plane bulk elastic waves, which can be simultaneously located at the frequency range from 1.223 to 1.251 MHz, are numerically observed. Robust pseudospin-dependent elastic edge wave propagation along arbitrary paths is further demonstrated. Our results will significantly broaden its practical application in the engineering field.
The KLOE fiber electromagnetic calorimeter
International Nuclear Information System (INIS)
Incagli, Marco
1998-01-01
The construction and equipment of the KLOE electromagnetic calorimeter has ended in March 1997. In parallel to the construction, all modules have been tested at the Cosmic Ray Test Stand (CRTS) facility, in Frascati National Laboratories (Rome). The construction technique, based on scintillating fibers alternated to very thin (0.5 mm) grooved lead planes, is described and the main results both from the CRTS and from a preliminary Test Beam with low energy electrons and muons are reported in this note
Freehand biopsy guided by electromagnetic needle tracking
DEFF Research Database (Denmark)
Ewertsen, C; Nielsen, Marie Kristina Rue; Nielsen, M Bachmann
2011-01-01
To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking.......To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking....
Fressengeas, Nicolas
2010-01-01
The physics of polarization optics *Polarized light propagation *Partially polarized light; DEA; After a brief introduction to polarization optics, this lecture reviews the basic formalisms for dealing with it: Jones Calculus for totally polarized light and Stokes parameters associated to Mueller Calculus for partially polarized light.
Electro-magnetic waves within a model for charged solitons
International Nuclear Information System (INIS)
Borisyuk, Dmitry; Faber, Manfried; Kobushkin, Alexander
2007-01-01
We analyse the model of topological fermions (MTF), where charged fermions are treated as soliton solutions of the field equations. In the region far from the sources we find plane waves solutions with the properties of electro-magnetic waves
Scattering by an electromagnetic radiation field
Bini, D.; Geralico, A.
2012-02-01
Motion of test particles in the gravitational field associated with an electromagnetic plane wave is investigated. The interaction with the radiation field is modeled by a force term à la Poynting-Robertson entering the equations of motion given by the 4-momentum density of radiation observed in the particle’s rest frame with a multiplicative constant factor expressing the strength of the interaction itself. Explicit analytical solutions are obtained. Scattering of fields by the electromagnetic wave, i.e., scalar (spin 0), massless spin (1)/(2) and electromagnetic (spin 1) fields, is studied too.
Development of a strong electromagnet wiggler
International Nuclear Information System (INIS)
Burns, M.J.; Deis, G.A.; Holmes, R.H.; Van Maren, R.D.; Halbach, K.
1987-01-01
The Strong Electromagnet (SEM) wiggler is a permanent magnet-assisted electromagnet under development at the Lawrence Livermore National Laboratory (LLNL) as part of the Induction Linac Free-Electron-Laser (IFEL) program. This concept uses permanent magnets within the wiggler to provide a reverse bias flux in the iron and thus delay the onset of magnetic saturation. The electromagnet coils determine the wiggler field and operate at low current densities by virtue of their placement away from the midplane. We describe here the design approach used and test data from a 7-period wiggler prototype that includes curved pole tips to provide wiggle-plane focusing. 7 refs
Multifrequency Behaviour of Polars
Directory of Open Access Journals (Sweden)
K. Reinsch
2015-02-01
Full Text Available Cataclysmic variables emit over a wide range of the electromagnetic spectrum. In this paper I will review observations of polars in relevant passbands obtained during the last decade and will discuss their diagnostical potential to access the physics of the main components within the binary systems. This will include a discussion of intrinsic source variability and the quest for simultaneous multi-frequency observations.
Energy Technology Data Exchange (ETDEWEB)
Bourdier, A
1999-07-01
This work concerns mainly the dynamics of a charged particle in an electromagnetic wave. It is a first step in elaborating a more general model permitting to predict the wave-particle interaction. We show how deriving a first integral gives an idea on how to create an electron current in a cold electron plasma. We present results which can be used to test the 2D and 3D Vlasov-Maxwell codes being built up in CEA-DAM. These codes will allow the calcination of the magnetic field created by an electromagnetic wave like the one due to the inverse Faraday effect when a circularly polarized wave drives the electrons of a plasma into circular orbits. (author)
Energy Technology Data Exchange (ETDEWEB)
Gomez R, F. [UAEM, A.P. 2-139, 50000 Toluca, Estado de Mexico (Mexico); Ondarza R, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)
2004-07-01
An analytical model for the description of the movement of a charged particle in the interaction of an electromagnetic pulse elliptically polarized propagating along of a static and homogeneous external magnetic field in a plasma starting from the force equation is presented. The method allows to express the solution in terms of the invariant phase, obtaining differential equations for the trajectory of the accelerated particle by means of an electromagnetic pulse of arbitrary amplitude and modulated by an encircling Gaussian. The numerical solutions reported in this work can find varied applications, for example in the physics of the interaction laser-plasma, in the acceleration of particles, in hot plasma and in radiative effects. (Author)
Energy Technology Data Exchange (ETDEWEB)
Gomez R, F. [UAEM, Facultad de Ciencias, 50000 Toluca, Estado de Mexico (Mexico); Ondarza R, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)
2004-07-01
An analytic model is presented for the description of the motion of a charged particle in the interaction of an elliptically electromagnetic pulse polarized propagating along a static and homogeneous external magnetic field in a plasma starting from the force equation. The method allows to express the solution in terms of the invariant phase, obtaining differential equations for the trajectory of the accelerated particle by means of an electromagnetic pulse of arbitrary and modulated width by an encircling Gaussian. The numerical solutions reported in this work can find varied applications, for example in the physics of the interaction laser-plasma, in the acceleration of particles, in hot plasma and in radioactive effects. (Author)
Electromagnetically induced transparency in 6Li
International Nuclear Information System (INIS)
Fuchs, J; Duffy, G J; Rowlands, W J; Akulshin, A M
2006-01-01
We report electromagnetically induced transparency for the D1 and D2 lines in 6 Li in both a vapour cell and an atomic beam. Electromagnetically induced transparency is created using copropagating mutually coherent laser beams with a frequency difference equal to the hyperfine ground state splitting of 228.2 MHz. The effects of various optical polarization configurations and applied magnetic fields are investigated. In addition, we apply an optical Ramsey spectroscopy technique which further reduces the observed resonance width
Computational Electromagnetics
Rylander, Thomas; Bondeson, Anders
2013-01-01
Computational Electromagnetics is a young and growing discipline, expanding as a result of the steadily increasing demand for software for the design and analysis of electrical devices. This book introduces three of the most popular numerical methods for simulating electromagnetic fields: the finite difference method, the finite element method and the method of moments. In particular it focuses on how these methods are used to obtain valid approximations to the solutions of Maxwell's equations, using, for example, "staggered grids" and "edge elements." The main goal of the book is to make the reader aware of different sources of errors in numerical computations, and also to provide the tools for assessing the accuracy of numerical methods and their solutions. To reach this goal, convergence analysis, extrapolation, von Neumann stability analysis, and dispersion analysis are introduced and used frequently throughout the book. Another major goal of the book is to provide students with enough practical understan...
International Nuclear Information System (INIS)
Tzeng, Wen-Shian V.
1991-01-01
Electromagnetic interference (EMI) shielding materials are well known in the art in forms such as gaskets, caulking compounds, adhesives, coatings and the like for a variety of EMI shielding purposes. In the past, where high shielding performance is necessary, EMI shielding has tended to use silver particles or silver coated copper particles dispersed in a resin binder. More recently, aluminum core silver coated particles have been used to reduce costs while maintaining good electrical and physical properties. (author). 8 figs
Energy Technology Data Exchange (ETDEWEB)
Aldridge, David F.
2014-11-01
A reciprocity theorem is an explicit mathematical relationship between two different wavefields that can exist within the same space - time configuration. Reciprocity theorems provi de the theoretical underpinning for mod ern full waveform inversion solutions, and also suggest practical strategies for speed ing up large - scale numerical modeling of geophysical datasets . In the present work, several previously - developed electromagnetic r eciprocity theorems are generalized to accommodate a broader range of medi um, source , and receiver types. Reciprocity relations enabling the interchange of various types of point sources and point receivers within a three - dimensional electromagnetic model are derived. Two numerical modeling algorithms in current use are successfully tested for adherence to reciprocity. Finally, the reciprocity theorem forms the point of departure for a lengthy derivation of electromagnetic Frechet derivatives. These mathe matical objects quantify the sensitivity of geophysical electromagnetic data to variatio ns in medium parameters, and thus constitute indispensable tools for solution of the full waveform inverse problem. ACKNOWLEDGEMENTS Sandia National Labor atories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. Signif icant portions of the work reported herein were conducted under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories (SNL) and CARBO Ceramics Incorporated. The author acknowledges Mr. Chad Cannan and Mr. Terry Pa lisch of CARBO Ceramics, and Ms. Amy Halloran, manager of SNL's Geophysics and Atmospheric Sciences Department, for their interest in and encouragement of this work. Special thanks are due to Dr . Lewis C. Bartel ( recently retired from Sandia National Labo ratories
Polarization bremsstrahlung in α decay
International Nuclear Information System (INIS)
Amusia, M. Ya.; Zon, B. A.; Kretinin, I. Yu.
2007-01-01
A mechanism of formation of electromagnetic radiation that accompanies α decay and is associated with the emission of photons by electrons of atomic shells due to the scattering of α particles by these atoms (polarization bremsstrahlung) is proposed. It is shown that, when the photon energy is no higher than the energy of K electrons of an atom, polarization bremsstrahlung makes a significant contribution to the bremsstrahlung in α decay
High-efficiency broadband polarization converter based on Ω-shaped metasurface
Zhang, Tianyao; Huang, Lingling; Li, Xiaowei; Liu, Juan; Wang, Yongtian
2017-11-01
The polarization state, which cannot be directly detected by human eyes, forms an important characteristic of electromagnetic waves. Control of polarization states has long been pursued for various applications. Conventional polarization converters can hardly meet the requirements in lab-on-chip systems, due to the involvement of bulk materials. Here, we propose the design and realization of a linear to circular polarization converter based on metasurfaces. The metasurface is deliberately designed using achiral two-fold mirror symmetry Ω-shaped antennas. The converter integrates a ground metal plane, a spacer dielectric layer and an antenna array, leading to a high conversion efficiency and broad operating bandwidth in the near infrared regime. The calculated Stokes parameters indicate an excellent conversion of linear to circular polarization for the reflected light. The tunability of the bandwidth by oblique incidence and by modulating the thickness of the dielectric layer is also introduced and demonstrated, which shows great flexibilities for such metasurface converters. The proposed metasurface may open up intriguing possibilities towards the realization of ultrathin nanophotonic devices for polarization manipulation and wavefront engineering.
Ida, Nathan
2015-01-01
This book provides students with a thorough theoretical understanding of electromagnetic field equations and it also treats a large number of applications. The text is a comprehensive two-semester textbook. The work treats most topics in two steps – a short, introductory chapter followed by a second chapter with in-depth extensive treatment; between 10 to 30 applications per topic; examples and exercises throughout the book; experiments, problems and summaries. The new edition includes: updated end of chapter problems; a new introduction to electromagnetics based on behavior of charges; a new section on units; MATLAB tools for solution of problems and demonstration of subjects; most chapters include a summary. The book is an undergraduate textbook at the Junior level, intended for required classes in electromagnetics. It is written in simple terms with all details of derivations included and all steps in solutions listed. It requires little beyond basic calculus and can be used for self-study. The weal...
Noninvasive valve monitor using alternating electromagnetic field
Eissenberg, David M.; Haynes, Howard D.; Casada, Donald A.
1993-01-01
One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.
Interactions between electromagnetic fields and matter
Steiner, Karl-Heinz
2013-01-01
Interactions between Electromagnetic Fields and Matter deals with the principles and methods that can amplify electromagnetic fields from very low levels of signals. This book discusses how electromagnetic fields can be produced, amplified, modulated, or rectified from very low levels to enable these for application in communication systems. This text also describes the properties of matter and some phenomenological considerations to the reactions of matter when an action of external fields results in a polarization of the particle system and changes the bonding forces existing in the matter.
Komar fluxes of circularly polarized light beams and cylindrical metrics
Lynden-Bell, D.; Bičák, J.
2017-11-01
The mass per unit length of a cylindrical system can be found from its external metric as can its angular momentum. Can the fluxes of energy, momentum, and angular momentum along the cylinder also be so found? We derive the metric of a beam of circularly polarized electromagnetic radiation from the Einstein-Maxwell equations. We show how the uniform plane wave solutions miss the angular momentum carried by the wave. We study the energy, momentum, angular momentum, and their fluxes along the cylinder both for this beam and in general. The three Killing vectors of any stationary cylindrical system give three Komar flux vectors which in turn give six conserved fluxes. We elucidate Komar's mysterious factor 2 by evaluating Komar integrals for systems that have no trace to their stress tensors. The Tolman-Komar formula gives twice the energy for such systems which also have twice the gravity. For other cylindrical systems their formula gives correct results.
Emde, Claudia; Barlakas, Vasileios; Cornet, Céline; Evans, Frank; Wang, Zhen; Labonotte, Laurent C.; Macke, Andreas; Mayer, Bernhard; Wendisch, Manfred
2018-04-01
Initially unpolarized solar radiation becomes polarized by scattering in the Earth's atmosphere. In particular molecular scattering (Rayleigh scattering) polarizes electromagnetic radiation, but also scattering of radiation at aerosols, cloud droplets (Mie scattering) and ice crystals polarizes. Each atmospheric constituent produces a characteristic polarization signal, thus spectro-polarimetric measurements are frequently employed for remote sensing of aerosol and cloud properties. Retrieval algorithms require efficient radiative transfer models. Usually, these apply the plane-parallel approximation (PPA), assuming that the atmosphere consists of horizontally homogeneous layers. This allows to solve the vector radiative transfer equation (VRTE) efficiently. For remote sensing applications, the radiance is considered constant over the instantaneous field-of-view of the instrument and each sensor element is treated independently in plane-parallel approximation, neglecting horizontal radiation transport between adjacent pixels (Independent Pixel Approximation, IPA). In order to estimate the errors due to the IPA approximation, three-dimensional (3D) vector radiative transfer models are required. So far, only a few such models exist. Therefore, the International Polarized Radiative Transfer (IPRT) working group of the International Radiation Commission (IRC) has initiated a model intercomparison project in order to provide benchmark results for polarized radiative transfer. The group has already performed an intercomparison for one-dimensional (1D) multi-layer test cases [phase A, 1]. This paper presents the continuation of the intercomparison project (phase B) for 2D and 3D test cases: a step cloud, a cubic cloud, and a more realistic scenario including a 3D cloud field generated by a Large Eddy Simulation (LES) model and typical background aerosols. The commonly established benchmark results for 3D polarized radiative transfer are available at the IPRT website (http
An Omnidirectional Polarization Detector Based on a Metamaterial Absorber.
Zhang, Binzhen; Zhang, Yong; Duan, Junping; Zhang, Wendong; Wang, Wanjun
2016-07-23
The theory, design, simulation, fabrication, and performance of an omnidirectional polarization detector (PD) with two resonances located in the X and Ka ranges based on a metamaterial absorber (MMA) are presented in this paper. The sandwich structure of PD is composed of 0.1 μm periodic "I" shaped patches on the metasurface, a dielectric of 200 μm FR-4 on the interlayer, and a 0.3 μm copper film on the substrate. PD absorptivity is first used to reflect and describe the polarization of the incident wave. The numerical results, derived from the standard full wave finite integration technology (FIT) of CST 2015, indicates that the designed PD shows polarization sensitivity at all incidence angles. The effects on absorptivity produced by the incidence angles, polarization angles, and materials are investigated. The amplitude of absorptivity change caused by polarization reaches 99.802%. A laser ablation process is adopted to prepare the designed PD on a FR-4 board coated with copper on the double plane with a thickness that was 1/93 and 1/48 of wavelength at a resonance frequency of 16.055 GHz and 30.9 GHz, respectively. The sample test results verify the designed PD excellent detectability on the polarization of the incident waves. The proposed PD, which greatly enriches the applications of metamaterials in bolometers, thermal images, stealth materials, microstructure measurements, and electromagnetic devices, is easy to mass produce and market because of its strong detectability, ultrathin thickness, effective cost, and convenient process.
An Omnidirectional Polarization Detector Based on a Metamaterial Absorber
Directory of Open Access Journals (Sweden)
Binzhen Zhang
2016-07-01
Full Text Available The theory, design, simulation, fabrication, and performance of an omnidirectional polarization detector (PD with two resonances located in the X and Ka ranges based on a metamaterial absorber (MMA are presented in this paper. The sandwich structure of PD is composed of 0.1 μm periodic “I” shaped patches on the metasurface, a dielectric of 200 μm FR-4 on the interlayer, and a 0.3 μm copper film on the substrate. PD absorptivity is first used to reflect and describe the polarization of the incident wave. The numerical results, derived from the standard full wave finite integration technology (FIT of CST 2015, indicates that the designed PD shows polarization sensitivity at all incidence angles. The effects on absorptivity produced by the incidence angles, polarization angles, and materials are investigated. The amplitude of absorptivity change caused by polarization reaches 99.802%. A laser ablation process is adopted to prepare the designed PD on a FR-4 board coated with copper on the double plane with a thickness that was 1/93 and 1/48 of wavelength at a resonance frequency of 16.055 GHz and 30.9 GHz, respectively. The sample test results verify the designed PD excellent detectability on the polarization of the incident waves. The proposed PD, which greatly enriches the applications of metamaterials in bolometers, thermal images, stealth materials, microstructure measurements, and electromagnetic devices, is easy to mass produce and market because of its strong detectability, ultrathin thickness, effective cost, and convenient process.
Calculating Electromagnetic Fields Of A Loop Antenna
Schieffer, Mitchell B.
1987-01-01
Approximate field values computed rapidly. MODEL computer program developed to calculate electromagnetic field values of large loop antenna at all distances to observation point. Antenna assumed to be in x-y plane with center at origin of coordinate system. Calculates field values in both rectangular and spherical components. Also solves for wave impedance. Written in MicroSoft FORTRAN 77.
Freehand biopsy guided by electromagnetic needle tracking
DEFF Research Database (Denmark)
Ewertsen, C; Nielsen, Marie Kristina Rue; Nielsen, M Bachmann
2011-01-01
To evaluate the overall accuracy and time spent on biopsy guided by electromagnetic needle tracking in a phantom compared with the standard technique of US-guided biopsy with an attached steering device. Furthermore, to evaluate off-plane biopsy guided by needle tracking....
Assignment of multipolarity for ΔI= 0 γ transitions from polarization measurements
International Nuclear Information System (INIS)
Ali, Sajad; Rajbanshi, S.; Chattopadhyay, S.
2017-01-01
It is well known that the determination of the polarization for the γ transition will lead to the unique spin-parity assignments of the nuclear states. The electric and magnetic nature of the γ-rays are distinguishes by the direction of the electric vector of electromagnetic radiation with respect to the beam detector plane. The difference between the perpendicular and parallely scattered events due to the Compton scattering depends on the direction of electric vector of the emitted γ radiation. The difference is positive for electric type transition and negative for magnetic type transitions while for a mixed transitions it is almost zero. However, for the ΔI =0 γ transitions it can be shown theoretically that the difference is positive for magnetic type of transitions and negative for electric type of transitions. This opposite results of the polarization asymmetry for the ΔI =0 γ transitions may sometimes resulted in different assignments of the nuclear states
Nucleon Electromagnetic Form Factors
Energy Technology Data Exchange (ETDEWEB)
Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi
2007-10-01
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.
DEFF Research Database (Denmark)
Cermak, Daniel; Okutsu, Ayaka; Hasse, Stina
2015-01-01
Electromagnetic Landscape demonstrates in direct, tangible and immediate ways effects of the disruption of the familiar. An ubiquitous technological medium, FM radio, is turned into an alien and unfamiliar one. Audience participation, the environment, radio signals and noise create a site......-specific, ragged sonic landscape. The work exhibits intrinsic, non-trivial, emerging behaviour, cyclic or wave-like, which converges and ebbs. It varies its sonic and visual display through a dynamic interaction of light sources, fog and light sensors. The system maintains a fluxing state of ambivalence between...
International Nuclear Information System (INIS)
Burch, Aidan
2004-01-01
Working within the HPO (History Projection Operator) Consistent Histories formalism, we follow the work of Savvidou on (scalar) field theory [J. Math. Phys. 43, 3053 (2002)] and that of Savvidou and Anastopoulos on (first-class) constrained systems [Class. Quantum Gravt. 17, 2463 (2000)] to write a histories theory (both classical and quantum) of Electromagnetism. We focus particularly on the foliation-dependence of the histories phase space/Hilbert space and the action thereon of the two Poincare groups that arise in histories field theory. We quantize in the spirit of the Dirac scheme for constrained systems
What Are Electromagnetic Fields?
... sources of electromagnetic fields Besides natural sources the electromagnetic spectrum also includes fields generated by human-made sources: ... ability to break bonds between molecules. In the electromagnetic spectrum, gamma rays given off by radioactive materials, cosmic ...
Energy Technology Data Exchange (ETDEWEB)
Rodriguez Amaya, N.; Weiss, F.; Schmitt, A.
1991-04-18
An electromagnet, particularly for use in switching valves for the direct control of a fuel injection quantity on fuel injection pumps, has a magnet pot (25) made of soft magnetic material, an annular excitation coil (30) and a magnet armature (29), which is situated with a working air gap in front of the magnet pot (25). To improve the dynamic behaviour of the electromagnet (20), ie: to achieve extremely low switching times with simple manufacture of the magnetic circuit, the magnet pot (25) and/or the magnet armature (29) made as a solid part is provided with an even number of at least four radial slots (41), which pass through the magnet pot (25) or the magnet armature (29) over their whole axial length. Successive radial slots (41a, 41b) extend alternately from the outside or from the inside jacket surface (311 or 321) to near the inside or the outside jacket surface (321 or 311) respectively and end there, always leaving a bar of material (42 or 43).
High-altitude electromagnetic pulse environment over the lossy ground
International Nuclear Information System (INIS)
Xie Yanzhao; Wang Zanji
2003-01-01
The electromagnetic field above ground produced by an incident high-altitude electromagnetic pulse plane wave striking the ground plane was described in this paper in terms of the Fresnel reflection coefficients and the numerical FFT. The pulse reflected from the ground plane always cancel the incident field for the horizontal field component, but the reflected field adds to the incident for the vertical field component. The results of several cases for variations in the observation height, angle of incidence and lossy ground electrical parameters were also presented showing different e-field components above the earth
International Nuclear Information System (INIS)
Guo Bin
2009-01-01
Based on the electromagnetic theory and by using an analytical technique-the transfer matrix method, the obliquely incident electromagnetic waves propagating in one-dimension plasma photonic crystals is studied. The dispersion relations for both the P-polarization waves and S-polarization waves, depending on the plasma density, plasma thickness and period, are discussed. (basic plasma phenomena)
The electromagnet design for 3-D superconducting actuator using HTS bulk
International Nuclear Information System (INIS)
Kim, S.B.; Inoue, T.; Shimizu, A.; Murase, S.
2006-01-01
We have been developing a three-dimensional (3-D) superconducting actuator consists of a field-cooled HTS bulk for mover and two-dimensional arranged multiple electromagnets as a stator. The HTS bulk is magnetically connected with electromagnets and it can be moved in 3-D directions and rotates without upper side electromagnets and spatial restrictions. The current and the polarity of each electromagnet were individually controlled by the switching power supply. In this paper, we experimentally investigated the effects of the shapes of HTS bulks (disk shape with/without inner hole) and electromagnets (4 and 8 polarities) in points of stabilities and forces of levitation
International Nuclear Information System (INIS)
Ding Chaoliang; Lue Baida; Pan Liuzhan
2009-01-01
The unified theory of coherence and polarization proposed by Wolf is extended from stochastic stationary electromagnetic beams to stochastic spatially and spectrally partially coherent electromagnetic pulsed beams. Taking the stochastic electromagnetic Gaussian Schell-model pulsed (GSMP) beam as a typical example of stochastic spatially and spectrally partially coherent electromagnetic pulsed beams, the expressions for the spectral density, spectral degree of polarization and spectral degree of coherence of stochastic electromagnetic GSMP beams propagating in free space are derived. Some special cases are analyzed. The illustrative examples are given and the results are interpreted physically.
VIIRS/J1 polarization narrative
Waluschka, Eugene; McCorkel, Joel; McIntire, Jeff; Moyer, David; McAndrew, Brendan; Brown, Steven W.; Lykke, Keith R.; Young, James B.; Fest, Eric; Butler, James; Wang, Tung R.; Monroy, Eslim O.; Turpie, Kevin; Meister, Gerhard; Thome, Kurtis J.
2015-09-01
The polarization sensitivity of the Visible/NearIR (VISNIR) bands in the Joint Polar Satellite Sensor 1 (J1) Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was measured using a broadband source. While polarization sensitivity for bands M5-M7, I1, and I2 was less than 2.5 %, the maximum polarization sensitivity for bands M1, M2, M3, and M4 was measured to be 6.4 %, 4.4 %, 3.1 %, and 4.3 %, respectively with a polarization characterization uncertainty of less than 0.38%. A detailed polarization model indicated that the large polarization sensitivity observed in the M1 to M4 bands is mainly due to the large polarization sensitivity introduced at the leading and trailing edges of the newly manufactured VISNIR bandpass focal plane filters installed in front of the VISNIR detectors. This was confirmed by polarization measurements of bands M1 and M4 bands using monochromatic light. Discussed are the activities leading up to and including the two polarization tests, some discussion of the polarization model and the model results, the role of the focal plane filters, the polarization testing of the Aft-Optics-Assembly, the testing of the polarizers at the National Aeronautics and Space Administration's (NASA) Goddard center and at the National Institute of Science and Technology (NIST) facility and the use of NIST's Traveling Spectral Irradiance and Radiance responsivity Calibrations using Uniform Sources (T-SIRCUS) for polarization testing and associated analyses and results.
VIIRS-J1 Polarization Narrative
Waluschka, Eugene; McCorkel, Joel; McIntire, Jeff; Moyer, David; McAndrew, Brendan; Brown, Steven W.; Lykke, Keith; Butler, James; Meister, Gerhard; Thome, Kurtis J.
2015-01-01
The VIS/NIR bands polarization sensitivity of Joint Polar Satellite Sensor 1 (JPSS1) Visible/Infrared Imaging Radiometer Suite (VIIRS) instrument was measured using a broadband source. While polarization sensitivity for bands M5-M7, I1, and I2 was less than 2.5%, the maximum polarization sensitivity for bands M1, M2, M3, and M4 was measured to be 6.4%, 4.4%, 3.1%, and 4.3%, respectively with a polarization characterization uncertainty of less than 0.3%. A detailed polarization model indicated that the large polarization sensitivity observed in the M1 to M4 bands was mainly due to the large polarization sensitivity introduced at the leading and trailing edges of the newly manufactured VISNIR bandpass focal plane filters installed in front of the VISNIR detectors. This was confirmed by polarization measurements of bands M1 and M4 bands using monochromatic light. Discussed are the activities leading up to and including the instruments two polarization tests, some discussion of the polarization model and the model results, the role of the focal plane filters, the polarization testing of the Aft-Optics-Assembly, the testing of the polarizers at Goddard and NIST and the use of NIST's T-SIRCUS for polarization testing and associated analyses and results.
Electromagnetic topology: Characterization of internal electromagnetic coupling
Parmantier, J. P.; Aparicio, J. P.; Faure, F.
1991-01-01
The main principles are presented of a method dealing with the resolution of electromagnetic internal problems: Electromagnetic Topology. A very interesting way is to generalize the multiconductor transmission line network theory to the basic equation of the Electromagnetic Topology: the BLT equation. This generalization is illustrated by the treatment of an aperture as a four port junction. Analytical and experimental derivations of the scattering parameters are presented. These concepts are used to study the electromagnetic coupling in a scale model of an aircraft, and can be seen as a convenient means to test internal electromagnetic interference.
Electromagnetically shielded building
International Nuclear Information System (INIS)
Takahashi, T.; Nakamura, M.; Yabana, Y.; Ishikawa, T.; Nagata, K.
1992-01-01
This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs
Transformational plane geometry
Umble, Ronald N
2014-01-01
Axioms of Euclidean Plane Geometry The Existence and Incidence Postulates The Distance and Ruler Postulates The Plane Separation Postulate The Protractor Postulate The Side-Angle-Side Postulate and the Euclidean Parallel Postulate Theorems of Euclidean Plane Geometry The Exterior Angle Theorem Triangle Congruence Theorems The Alternate Interior Angles Theorem and the Angle Sum Theorem Similar Triangles Introduction to Transformations, Isometries, and Similarities Transformations Isometries and SimilaritiesAppendix: Proof of Surjectivity Translations, Rotations, and Reflections Translations Rotations Reflections Appendix: Geometer's Sketchpad Commands Required by Exploratory Activities Compositions of Translations, Rotations, and Reflections The Three Points Theorem Rotations as Compositions of Two Reflections Translations as Compositions of Two Halfturns or Two Reflections The Angle Addition Theorem Glide Reflections Classification of Isometries The Fundamental Theorem and Congruence Classification of Isometr...
Linear Time Varying Approach to Satellite Attitude Control Using only Electromagnetic Actuation
DEFF Research Database (Denmark)
Wisniewski, Rafal
1997-01-01
, lightweight, and power efficient actuators is therefore crucial and viable. This paper discusses linear attitude control strategies for a low earth orbit satellite actuated by a set of mutually perpendicular electromagnetic coils. The principle is to use the interaction between the Earth's magnetic field...... and the magnetic field generated by the coils. A key challenge is the fact that the mechanical torque can only be produced in a plane perpendicular to the local geomagnetic field vector, therefore the satellite is not controllable when considered at fixed time. Availability of design methods for time varying...... systems is limited, nevertheless, a solution of the Riccati equation gives an excellent frame for investigations provided in this paper. An observation that geomagnetic field changes approximately periodically when a satellite is on a near polar orbit is used throughout this paper. Three types of attitude...
Linear Time Varying Approach to Satellite Attitude Control Using only Electromagnetic Actuation
DEFF Research Database (Denmark)
Wisniewski, Rafal
2000-01-01
, lightweight, and power efficient actuators is therefore crucial and viable. This paper discusser linear attitude control strategies for a low earth orbit satellite actuated by a set of mutually perpendicular electromagnetic coils. The principle is to use the interaction between the Earth's magnetic field...... and the magnetic field generated by the coils. A key challenge is the fact that the mechanical torque can only be produced in a plane perpendicular to the local geomagnetic field vector, therefore the satellite is not controllable at fixed time. Avaliability of design methods for time varying systems is limited......, nevertheless, a solution of the riccati equation gives an excellent frame for investigations provided in this paper. An observation that geomagnetic field changes approximately periodically when satellite is on a near polar orbit is used throughout this paper. Three types of attitude controllers are proposed...
Energy Technology Data Exchange (ETDEWEB)
Sibella, F; Parazzini, M; Paglialonga, A; Ravazzani, P [Istituto di Ingegneria Biomedica, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci, 32, 20133 Milano (Italy)], E-mail: federica.sibella@polimi.it, E-mail: marta.parazzini@polimi.it, E-mail: alessia.paglialonga@polimi.it, E-mail: paolo.ravazzani@polimi.it
2009-04-21
Cochlear implants (CI) are electronic devices used to restore partial hearing to people with severe hearing impairment. This paper aims to investigate if the introduction of a CI has an effect on SAR distribution in a head model exposed to radiofrequency electromagnetic fields (RF EMF) at mobile communication frequencies. The head model was obtained by image segmentation, the implant was modelled as a geometric structure and the exposure source was modelled as a uniform plane wave at 900 MHz, 1750 MHz and 1950 MHz, incident on the side of the head with the CI. Vertical and horizontal polarizations were simulated. Results show that the presence of a CI inside the cochlea produces negligible variations in the averaged SAR values, both in the head and in the cochlear tissues, although very localized differences in point SAR were found in the cochlea. Globally, these results suggest that finding harmful effects in the cochlear tissues will be unlikely. (note)
Du, Kui
2011-07-01
We consider electromagnetic scattering from two-dimensional (2D) overfilled cavities embedded in an infinite ground plane. The unbounded computational domain is truncated to a bounded one by using a transparent boundary condition (TBC) proposed on a semi-ellipse. For overfilled rectangular cavities with homogeneous media, another TBC is introduced on the cavity apertures, which produces a smaller computational domain. The existence and uniqueness of the solutions of the variational formulations for the transverse magnetic and transverse electric polarizations are established. In the exterior domain, the 2D scattering problem is solved in the elliptic coordinate system using the Mathieu functions. In the interior domain, the problem is solved by a finite element method. Numerical experiments show the efficiency and accuracy of the new boundary conditions.
Assessment of induced radio-frequency electromagnetic fields in various anatomical human body models
International Nuclear Information System (INIS)
Kuehn, Sven; Jennings, Wayne; Christ, Andreas; Kuster, Niels
2009-01-01
The reference levels for testing compliance of human exposure with radio-frequency (RF) safety limits have been derived from very simplified models of the human. In order to validate these findings for anatomical models, we investigated the absorption characteristics for various anatomies ranging from 6 year old child to large adult male by numerical modeling. We address the exposure to plane-waves incident from all major six sides of the humans with two orthogonal polarizations each. Worst-case scattered field exposure scenarios have been constructed in order to test the implemented procedures of current in situ compliance measurement standards (spatial averaging versus peak search). Our findings suggest that the reference levels of current electromagnetic (EM) safety guidelines for demonstrating compliance as well as some of the current measurement standards are not consistent with the basic restrictions and need to be revised.
Assessment of induced radio-frequency electromagnetic fields in various anatomical human body models
Energy Technology Data Exchange (ETDEWEB)
Kuehn, Sven; Jennings, Wayne; Christ, Andreas; Kuster, Niels [Foundation for Research on Information Technologies in Society (IT' IS), Zuerich (Switzerland)], E-mail: kuehn@itis.ethz.ch
2009-02-21
The reference levels for testing compliance of human exposure with radio-frequency (RF) safety limits have been derived from very simplified models of the human. In order to validate these findings for anatomical models, we investigated the absorption characteristics for various anatomies ranging from 6 year old child to large adult male by numerical modeling. We address the exposure to plane-waves incident from all major six sides of the humans with two orthogonal polarizations each. Worst-case scattered field exposure scenarios have been constructed in order to test the implemented procedures of current in situ compliance measurement standards (spatial averaging versus peak search). Our findings suggest that the reference levels of current electromagnetic (EM) safety guidelines for demonstrating compliance as well as some of the current measurement standards are not consistent with the basic restrictions and need to be revised.
Topological Foundations of Electromagnetism
Barrett, Terrence W
2008-01-01
Topological Foundations of Electromagnetism seeks a fundamental understanding of the dynamics of electromagnetism; and marshals the evidence that in certain precisely defined topological conditions, electromagnetic theory (Maxwell's theory) must be extended or generalized in order to provide an explanation and understanding of, until now, unusual electromagnetic phenomena. Key to this generalization is an understanding of the circumstances under which the so-called A potential fields have physical effects. Basic to the approach taken is that the topological composition of electromagnetic field
The Effect of Tensile Strain on Optical Anisotropy and Exciton of m-Plane ZnO
Wang, H. H.
2015-03-20
The near band edge emission of the tensile-strained m-plane ZnO film grown on (112)LaAlO3 substrates shows abnormal low polarization degree (ρ = 0.1). The temperature dependency of polarization degree clarifies the origins of different emission peaks. In tensile-strained m-plane ZnO, the [0001] polarized state is upper shifted and is overlapping with the [112̅0] polarized state. This phenomenon causes the abnormal low polarization degree and reveals the effect of strain on the emission anisotropy of m-plane ZnO.
Zero-mass plane waves in nonzero gravitational backgrounds
International Nuclear Information System (INIS)
Chrzanowski, P.L.; Matzner, R.A.; Sandberg, V.D.; Ryan, M.P. Jr.
1976-01-01
The mathematical definition of what is intuitively called a ''plane wave'' on the curved background of a black hole is clarified and discussed from the viewpoints of potentials and fields. Because of the long-range Newtonian part of the gravitational field the asymptotic wave fronts of an incident ''plane wave'' (describing a radiative perturbation for a scattering experiment) are distorted in a manner analogous to the wave fronts of an electron beam in the quantum-mechanical Coulomb scattering problem. In addition, the electromagnetic and gravitational fields can be described with either a potential formalism (i.e., the vector potential and the metric perturbation) or a field formalism (i.e., the electromagnetic field tensor and the Riemann tensor). In this paper we present a distorted ''plane wave'' prescription, necessary for the calculation of the scattering cross sections of electromagnetic and gravitational waves off of a black hole, which agrees with the accepted prescription for a massless scalar field and satisfies the intuitive notions of what constitutes a ''plane wave'' in terms of potentials and fields
DEFF Research Database (Denmark)
Jensen, Jonas
This PhD project investigates and further develops methods for ultrasound plane wave imaging and blood flow estimation with the objective of overcoming some of the major limitations in conventional ultrasound systems, which are related to low frame rates and only estimation of velocities along th...
Teaching Electromagnetic Waves in College Physics Laboratory
Kezerashvili, Roman Y.; Leng, L.
2006-12-01
One of the important educational advantages of the simultaneous study of the electromagnetic waves and light is to show that light and the electromagnetic radiation have the same properties so that the students can visualize the properties of the electromagnetic radiation through observation of light propagation. In our approach we are suggest to study the properties of a microwave radiation and light in parallel. The following experiments can be easily designed and they provide a methodical introduction to electromagnetic theory using the microwave radiation and light: the study of the inverse square law of the dependence of the intensity of radiation (microwave and light) on the distance, the law of reflection and refraction, investigation of the phenomenon of polarization and how a polarizer can be used to alter the polarization of microwave radiation and light, measuring the Brewster's angle, studying interference by performing double-slit experiment for microwave radiation and light. Finally students measure the wavelength of the laser light and microwave radiation using the corresponding versions the Michelson’s interferometer, and recognize that these two radiations only differ by the wavelength or frequency.
Energy conversion evolution at lunar polar sites
Indian Academy of Sciences (India)
described the motions of the Moon, including the orientation and precession of its spin axis rela- tive to its orbit and the plane of the ecliptic. The Moon's polar axis is inclined only about one- and-a-half degrees from the ecliptic pole, with the result that sunlight is nearly continuous and always horizontal in lunar polar regions.
Gravitational radiation from electromagnetic systems
International Nuclear Information System (INIS)
Nikishov, A.I.; Ritus, V.I.
1989-01-01
It is shown that the spectrum of gravitational radiation of a charge e with mass m, undergoing finite motion in an electromagnetic field, smoothly varying in the neighborhood of the orbit over a region of the order of the radius of curvature, differs in the ultrarelativistic limit from the spectrum of the charge's electromagnetic radiation. The difference consists of the frequency-independent coefficient 4πGm 2 Λ 2 /e 2 , where Λ is of the order of the Lorentz factor of the charge and depends on the direction of the wave vector and on the behavior of the field in the above-indicated region. For a plane-wave external field the gravitational and electromagnetic spectra are strictly proportional to each other for arbitrary velocities of the charge. Localization of the external forces near the orbit violates this proportionality of the spectra and weakens the gravitational radiation by an amount of the order of the square of the Lorentz factor
Energy Technology Data Exchange (ETDEWEB)
Xia, Xiaodong [School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092 (China); Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, New Jersey 08903 (United States); Wang, Yang; Weng, George J., E-mail: weng@jove.rutgers.edu [Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, New Jersey 08903 (United States); Zhong, Zheng [School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092 (China)
2016-08-28
This work was driven by the need to understand the electromagnetic interference (EMI) shielding effectiveness (SE) of light weight, flexible, and high performance graphene composite foams, but as EMI SE of a material depends on its electrical conductivity, dielectric permittivity, and magnetic permeability, the investigation of these three properties also became a priority. In this paper, we first present a continuum theory to determine these three electromagnetic properties, and then use the obtained properties to evaluate the EMI SE of the foam. A two-scale composite model is conceived to evaluate these three properties, with the large one being the skeleton-void composite and the small one being the graphene-polymer composite that serves as the skeleton of the foam. To evaluate the properties of the skeleton, the effective-medium approach is taken as the starting point. Subsequently, the effect of an imperfect interface and the contributions of electron tunneling to the interfacial conductivity and Maxwell-Wagner-Sillars polarization mechanism to the dielectric constant are also implemented. The derived skeleton properties are then utilized on the large scale to determine the three properties of the composite foam at a given porosity. Then a uniform plane electromagnetic wave is considered to evaluate the EMI SE of the foam. It is demonstrated that the electrical conductivity, dielectric constant, and EMI SE of the foam calculated from the developed theory are in general agreement with the reported experimental data of graphene/PDMS composite foams. The theory is further proven to be valid for the EMI SE of solid graphene/epoxy and solid carbon nanotube/epoxy nanocomposites. It is also shown that, among the three electromagnetic properties, electrical conductivity has the strongest influence on the EMI shielding effectiveness.
HAWC+/SOFIA Instrumental Polarization Calibration
Michail, Joseph M.; Chuss, David; Dowell, Charles D.; Santos, Fabio; Siah, Javad; Vaillancourt, John; HAWC+ Instrument Team
2018-01-01
HAWC+ is a new far-infrared polarimeter for the NASA/DLR SOFIA (Stratospheric Observatory for Infrared Astronomy) telescope. HAWC+ has the capability to measure the polarization of astronomical sources with unprecedented sensitivity and angular resolution in four bands from 50-250 microns. Using data obtained during commissioning flights, we implemented a calibration strategy that separates the astronomical polarization signal from the induced instrumental polarization. The result of this analysis is a map of the instrumental polarization as a function of position in the instrument's focal plane in each band. The results show consistency between bands, as well as with other methods used to determine preliminary instrumental polarization values.
Cui, Chaojie
2018-01-30
Enriching the functionality of ferroelectric materials with visible-light sensitivity and multiaxial switching capability would open up new opportunities for their applications in advanced information storage with diverse signal manipulation functions. We report experimental observations of robust intra-layer ferroelectricity in two-dimensional (2D) van der Waals layered -In2Se3 ultrathin flakes at room temperature. Distinct from other 2D and conventional ferroelectrics, In2Se3 exhibits intrinsically intercorrelated out-of-plane and in-plane polarization, where the reversal of the out-of-plane polarization by a vertical electric field also induces the rotation of the in-plane polarization. Based on the in-plane switchable diode effect and the narrow bandgap (~1.3 eV) of ferroelectric In2Se3, a prototypical non-volatile memory device, which can be manipulated both by electric field and visible light illumination, is demonstrated for advancing data storage technologies.
Johnson, Aylmer
2014-01-01
IntroductionAim And ScopeClassification Of SurveysThe Structure Of This BookGeneral Principles Of SurveyingErrorsRedundancyStiffnessAdjustmentPlanning And Record KeepingPrincipal Surveying ActivitiesEstablishing Control NetworksMappingSetting OutResectioningDeformation MonitoringAngle MeasurementThe Surveyor's CompassThe ClinometerThe Total StationMaking ObservationsChecks On Permanent AdjustmentsDistance MeasurementGeneralTape MeasurementsOptical Methods (Tachymetry)Electromagnetic Distance Measurement (EDM)Ultrasonic MethodsGNSSLevellingTheoryThe InstrumentTechniqueBookingPermanent Adjustmen
Vectorial field propagation through high NA objectives using polarized Gaussian beam decomposition
Worku, N.; Gross, H.
2017-08-01
Scalar fields can be propagated through non-paraxial systems using the Gaussian beam decomposition method. However, for high NA objectives, this scalar treatment is not sufficient to correctly describe the electromagnetic fields inside the focal region due to high ray bendings, which result in a significant change in the polarization state of light. To model these vectorial effects, the Gaussian beam decomposition method has to be extended to include the polarization state of light. In this work we have combined it with the three dimensional polarization ray tracing in order to propagate vectorial fields through high NA optical systems. During the Gaussian beam decomposition, the polarization state of each individual beamlet is represented by a polarization vector [𝐸𝑥, 𝐸𝑦, 𝐸𝑧 ] associated with its central ray. Individual Gaussian beams are then propagated through the system using the complex ray tracing method. The effect of the optical system on the polarization state of each beam is computed by applying the three dimensional polarization ray tracing of the corresponding central rays. Finally the individual beams are superposed coherently in the plane of interest resulting in the complete vectorial field. We apply the proposed method to compute the vectorial field inside the focal region of a high NA microscope objective lens and compare our result to the vectorial Debye integral method. We find that the Gaussian beam decomposition method overcomes serious limitations of algorithms relying on Fourier transforms, i.e. the field sampling requirements are less critical in high NA focusing and in the presence of large aberrations. However, sharp edges in the amplitude profile are difficult to handle as they should be replaced with smooth Gaussian edge.
New family of exact solutions for colliding plane gravitational waves
International Nuclear Information System (INIS)
Yurtsever, U.
1988-01-01
We construct an infinite-parameter family of exact solutions to the vacuum Einstein field equations describing colliding gravitational plane waves with parallel polarizations. The interaction regions of the solutions in this family are locally isometric to the interiors of those static axisymmetric (Weyl) black-hole solutions which admit both a nonsingular horizon, and an analytic extension of the exterior metric to the interior of the horizon. As a member of this family of solutions we also obtain, for the first time, a colliding plane-wave solution where both of the two incoming plane waves are purely anastigmatic, i.e., where both incoming waves have equal focal lengths
International Nuclear Information System (INIS)
Foda, Omar; Wheeler, Michael
2007-01-01
Using BKP neutral fermions, we derive a product expression for the generating function of volume-weighted plane partitions that satisfy two conditions. If we call a set of adjacent equal height-h columns, h > 0, an h-path, then 1. Every h-path can assume one of two possible colours. 2. There is a unique way to move along an h-path from any column to another
Energy Technology Data Exchange (ETDEWEB)
Foda, Omar; Wheeler, Michael [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)
2007-01-15
Using BKP neutral fermions, we derive a product expression for the generating function of volume-weighted plane partitions that satisfy two conditions. If we call a set of adjacent equal height-h columns, h > 0, an h-path, then 1. Every h-path can assume one of two possible colours. 2. There is a unique way to move along an h-path from any column to another.
Field theory of polar continua
International Nuclear Information System (INIS)
Heinz, C.
1988-01-01
A Lagrangian density in the polar space X 1+3+3 depending of the potentials and their derivativs and of the fluxes is introduced. The potentials are then the mechanical and electromagnetic potentials, the potentials of gravity and in the polar space X 1+3+3 the components of affine connection. The fluxes are essentially the tangential motors of the mechanical and electromagnetic world-lines multiplied with the density of mass and electric charge. The Hamilton principle gives, with the in variational calculus usual integrations by part, here done via the theorem of Gauss, the equations of motion and the field equations. The conditions of integrability for these equations are discussed. (author)
Chandrasekaran, Ramya
Over the past few years, significant effort was dedicated to the development of ultraviolet light emitting diodes (UV-LEDs) for a variety of applications. Such applications include chemical and biological detection, water purification and solid-state lighting. III-Nitride LEDs based on multiple quantum wells (MQWs) grown along the conventional [0001] (polar) direction suffer from the quantum confined Stark effect (QCSE), due to the existence of strong electric fields that arise from spontaneous and piezoelectric polarization. Thus, there is strong motivation to develop MQW-based III-nitride LED structures grown along non-polar and semi-polar directions. The goal of this dissertation is to develop UV-LEDs along the [0001] polar and [11 2¯ 0] non-polar directions by the method of Molecular Beam Epitaxy (MBE). The polar and non-polar LEDs were grown on the C-plane and R-plane sapphire substrates respectively. This work is a combination of materials science studies related to the nucleation, growth and n- and p-type doping of III-nitride films on these two substrates, as well as device studies related to fabrication and characterization of UV-LEDs. It was observed that the crystallographic orientation of the III-nitride films grown on R-plane sapphire depends strongly on the kinetic conditions of growth of the Aluminum Nitride (AIN) buffer. Specifically, growth of the AIN buffer under group III-rich conditions leads to nitride films having the (11 2¯ 0) non polar planes parallel to the sapphire surface, while growth of the buffer under nitrogen rich conditions leads to nitride films with the (11 2¯ 6) semi-polar planes parallel to the sapphire surface. The electron concentration and mobility for the films grown along the polar, non-polar and semi-polar directions were investigated. P-type doping of Gallium Nitride (GaN) films grown on the nonpolar (11 2¯ 0) plane do not suffer from polarity inversion and thus the material was doped p-type with a hole concentration
A programmable metasurface with dynamic polarization, scattering and focusing control
Yang, Huanhuan; Cao, Xiangyu; Yang, Fan; Gao, Jun; Xu, Shenheng; Li, Maokun; Chen, Xibi; Zhao, Yi; Zheng, Yuejun; Li, Sijia
2016-10-01
Diverse electromagnetic (EM) responses of a programmable metasurface with a relatively large scale have been investigated, where multiple functionalities are obtained on the same surface. The unit cell in the metasurface is integrated with one PIN diode, and thus a binary coded phase is realized for a single polarization. Exploiting this anisotropic characteristic, reconfigurable polarization conversion is presented first. Then the dynamic scattering performance for two kinds of sources, i.e. a plane wave and a point source, is carefully elaborated. To tailor the scattering properties, genetic algorithm, normally based on binary coding, is coupled with the scattering pattern analysis to optimize the coding matrix. Besides, inverse fast Fourier transform (IFFT) technique is also introduced to expedite the optimization process of a large metasurface. Since the coding control of each unit cell allows a local and direct modulation of EM wave, various EM phenomena including anomalous reflection, diffusion, beam steering and beam forming are successfully demonstrated by both simulations and experiments. It is worthwhile to point out that a real-time switch among these functionalities is also achieved by using a field-programmable gate array (FPGA). All the results suggest that the proposed programmable metasurface has great potentials for future applications.
Scattering by an electromagnetic radiation field
Bini, Donato; Geralico, Andrea
2014-01-01
Motion of test particles in the gravitational field associated with an electromagnetic plane wave is investigated. The interaction with the radiation field is modeled by a force term {\\it \\`a la} Poynting-Robertson entering the equations of motion given by the 4-momentum density of radiation observed in the particle's rest frame with a multiplicative constant factor expressing the strength of the interaction itself. Explicit analytical solutions are obtained. Scattering of fields by the elect...
Electromagnetic wave matching device
International Nuclear Information System (INIS)
Hirata, Yosuke; Mitsunaka, Yoshika; Hayashi, Ken-ichi; Ito, Yasuyuki.
1997-01-01
The present invention provides an electromagnetic wave matching capable of reducing a cost for the transmission system in a system of using electromagnetic waves for plasma heating of a thermonuclear reactor. Namely, incident electromagnetic waves are reflected by using a plurality of phase correction mirrors. The reflected electromagnetic waves are connected to an external transmission system through an exit. The phase correction mirrors have such a shape to receive a plurality of beam-like electromagnetic waves and output electromagnetic waves by the number different from the number of the received electromagnetic wave beams having a predetermined distribution. Further, at least two of the phase correction mirrors have such a shape to change the phase of the electromagnetic waves beams incident to the reflection surface of the phase correction mirrors by a predetermined amount corresponding to the position of the reflection surface. Then, the cost for transmission system can greatly be reduced. (I.S.)
COHERENCE PROPERTIES OF ELECTROMAGNETIC RADIATION,
ELECTROMAGNETIC RADIATION , COHERENT SCATTERING), (*COHERENT SCATTERING, ELECTROMAGNETIC RADIATION ), LIGHT, INTERFERENCE, INTENSITY, STATISTICAL FUNCTIONS, QUANTUM THEORY, BOSONS, INTERFEROMETERS, CHINA
International Nuclear Information System (INIS)
Prescott, C.Y.
1993-07-01
Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist
Dautov, O. Sh.
2017-01-01
As one means to solving propagation problems are considered modeling of electromagnetic wave in inhomogeneous layered media. There are exact relations for the field exciting by the plane monochromatic electromagnetic wave in flat-layered one-dimensional inhomogeneous isotropic media is used in this paper for analysis field structure in media with linear dependence characteristic impedance along propagation directions.
National Research Council Canada - National Science Library
Kriezis, E. E; Chrissoulidis, D. P; Papagiannakis, A. G
1992-01-01
..., since light is a high-frequency electromagnetic radiation. Although both electromagnetics and optics are their common origin is only superficially realised physics or electrical engineering. Deeper physical by treating electromagnetics and optics in parallel thus enlightening the natural link between them. By presenting principles, theory a...
Electromagnetic Education in India
Bajpai, Shrish; Asif, Siddiqui Sajida; Akhtar, Syed Adnan
2016-01-01
Out of the four fundamental interactions in nature, electromagnetics is one of them along with gravitation, strong interaction and weak interaction. The field of electromagnetics has made much of the modern age possible. Electromagnets are common in day-to-day appliances and are becoming more conventional as the need for technology increases.…
Error Analysis on Plane-to-Plane Linear Approximate Coordinate ...
Indian Academy of Sciences (India)
c Indian Academy of Sciences. Error Analysis on Plane-to-Plane Linear Approximate Coordinate. Transformation. Q. F. Zhang1,∗, Q. Y. Peng1 & J. H. Fan2 ... In astronomy, some tasks require performing the coordinate transformation between two tangent planes in ... Based on these parameters, we get maxi- mum errors in ...
International Nuclear Information System (INIS)
Rensburg, E J Janse van; Ma, J
2006-01-01
We examine partitions and their natural three-dimensional generalizations, plane partitions, as models of vesicles undergoing an inflation-deflation transition. The phase diagrams of these models include a critical point corresponding to an inflation-deflation transition, and exhibits multicritical scaling in the vicinity of a multicritical point located elsewhere on the critical curve. We determine the locations of the multicritical points by analysing the generating functions using analytic and numerical means. In addition, we determine the numerical values of the multicritical scaling exponents associated with the multicritical scaling regimes in these models
Theory of electromagnetic fields
Wolski, Andrzej
2011-01-01
We discuss the theory of electromagnetic fields, with an emphasis on aspects relevant to radiofrequency systems in particle accelerators. We begin by reviewing Maxwell's equations and their physical significance. We show that in free space, there are solutions to Maxwell's equations representing the propagation of electromagnetic fields as waves. We introduce electromagnetic potentials, and show how they can be used to simplify the calculation of the fields in the presence of sources. We derive Poynting's theorem, which leads to expressions for the energy density and energy flux in an electromagnetic field. We discuss the properties of electromagnetic waves in cavities, waveguides and transmission lines.
Djakou, Audrey Kamta; Darmon, Michel; Fradkin, Larissa; Potel, Catherine
2015-11-01
Diffraction phenomena studied in electromagnetism, acoustics, and elastodynamics are often modeled using integrals, such as the well-known Sommerfeld integral. The far field asymptotic evaluation of such integrals obtained using the method of steepest descent leads to the classical Geometrical Theory of Diffraction (GTD). It is well known that the method of steepest descent is inapplicable when the integrand's stationary phase point coalesces with its pole, explaining why GTD fails in zones where edge diffracted waves interfere with incident or reflected waves. To overcome this drawback, the Uniform geometrical Theory of Diffraction (UTD) has been developed previously in electromagnetism, based on a ray theory, which is particularly easy to implement. In this paper, UTD is developed for the canonical elastodynamic problem of the scattering of a plane wave by a half-plane. UTD is then compared to another uniform extension of GTD, the Uniform Asymptotic Theory (UAT) of diffraction, based on a more cumbersome ray theory. A good agreement between the two methods is obtained in the far field.
Wojcieszak, M.; Mazzoleni, G.; Barnhurst, K.G.; Ikeda, K.; Maia, R.C.M.; Wessler, H.
2015-01-01
Polarization has been studied in three different forms: on a social, group, and individual level. This entry first focuses on the undisputed phenomenon of elite polarization (i.e., increasing adherence of policy positions among the elites) and also outlines different approaches to assessing mass
DEFF Research Database (Denmark)
Nikolova, L.; Ramanujam, P.S.
Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...
Absorption of resonant electromagnetic radiation in electron-atom collisions
International Nuclear Information System (INIS)
Arslanbekov, T.U.; Pazdzerskii, V.A.; Usachenko, V.I.
1986-01-01
Nonrelativistic quantum theory is used to study the possibility of amplification of electromagnetic radiation in forced braking scattering of an electron beam on atoms. The interaction of the atom with the electromagnetic field is considered in the resonant approximation. Cases of large and small detuning from resonance are considered. It is shown that for any orientation of the electron beam relative to the field polarization vector, absorption of radiation occurs, with the major contribution being produced by atomic electrons
Lange, M; Guénon, S; Lever, F; Kleiner, R; Koelle, D
2017-12-01
Polarized light microscopy, as a contrast-enhancing technique for optically anisotropic materials, is a method well suited for the investigation of a wide variety of effects in solid-state physics, as, for example, birefringence in crystals or the magneto-optical Kerr effect (MOKE). We present a microscopy setup that combines a widefield microscope and a confocal scanning laser microscope with polarization-sensitive detectors. By using a high numerical aperture objective, a spatial resolution of about 240 nm at a wavelength of 405 nm is achieved. The sample is mounted on a 4 He continuous flow cryostat providing a temperature range between 4 K and 300 K, and electromagnets are used to apply magnetic fields of up to 800 mT with variable in-plane orientation and 20 mT with out-of-plane orientation. Typical applications of the polarizing microscope are the imaging of the in-plane and out-of-plane magnetization via the longitudinal and polar MOKE, imaging of magnetic flux structures in superconductors covered with a magneto-optical indicator film via the Faraday effect, or imaging of structural features, such as twin-walls in tetragonal SrTiO 3 . The scanning laser microscope furthermore offers the possibility to gain local information on electric transport properties of a sample by detecting the beam-induced voltage change across a current-biased sample. This combination of magnetic, structural, and electric imaging capabilities makes the microscope a viable tool for research in the fields of oxide electronics, spintronics, magnetism, and superconductivity.
Highly excited atom in the electromagnetic field
International Nuclear Information System (INIS)
Delone, N.B.; Krajnov, V.P.; Shepelyanskij, D.L.; AN SSSR, Novosibirsk. Inst. Yadernoj Fiziki)
1983-01-01
Properties of highly excited atom placed in electromagnetic field are reviewed. Probabilities of bound-boUnd and bound-free transition between quasi-classical atomic states, as well approximate rules of selection for such transitions, are considered. Properties of dynamic polarization of highly excited atomic states are investigated. Quantum mechanisms of ionization (multiphoton and tunnel) of highly excited states are discussed. A considerable part of the review is devoted to the consideration of the stochastic dynamics of the classic atomic electron in the variable monochromatic electromagnetic field. Threshold values of field intensity for the appearance of stochastic electron motion and atom ionization depending on field frequency, its polarization and the main quantum number of the atomic state considered are presented. The effect of the orbital moment of the ionized state on the process of stochasticity appearance is discussed. In the framework of classical mechanics and quasiclassical approximation of quantum mechanics the classical diffusion ionization of highly excited atom in electromagnetic field is considered. The problem on the application of classical mechanics in the investigation of properties of highly excited atom in electromagnetic field is discussed. Conditions for the realization of quantum and quasiclassic ionization of highly excited atoms are considered. In the last part of the review experimental data on the behaviour of highly excited atoms in the field of radiofrequency range are analyzed. The comparison of the data of experiments and those of the theory given in the revieW deronstrate their good agreement
DEFF Research Database (Denmark)
Manolova, Anna Vasileva; Ruepp, Sarah Renée
2010-01-01
. The applicability analysis carried out here focuses on the actual feasibility of the integration and the potential trade-offs which appear when two contradicting principles are combined. Taking advantage of the flexibility of the GMPLS control plane does not seem to be as easy and as straightforward as expected....... Thus, more than ten years later not many practical implementations of OBS networks with intelligent control can be found. The lack of active work in the ¯eld results in an incomplete set of proposals which address only few aspects of the integration challenge. Here, we analyze what is missing and why...... the existing solutions seem not to be able to provide the highly desirable strict QoS guarantees for the clients of the OBS networks....
Amstrup, Steven C.; Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.
2002-01-01
Polar bears (Ursus maritimus) are hunted throughout most of their range. In addition to hunting polar bears of the Beaufort Sea region are exposed to mineral and petroleum extraction and related human activities such as shipping road-building, and seismic testing (Stirling 1990).Little was known at the start of this project about how polar bears move about in their environment, and although it was understood that many bears travel across political borders, the boundaries of populations had not been delineated (Amstrup 1986, Amstrup et al. 1986, Amstrup and DeMaster 1988, Garner et al. 1994, Amstrup 1995, Amstrup et al. 1995, Amstrup 2000).As human populations increase and demands for polar bears and other arctic resources escalate, managers must know the sizes and distributions of the polar bear populations. Resource managers also need reliable estimates of breeding rates, reproductive intervals, litter sizes, and survival of young and adults.Our objectives for this research were 1) to determine the seasonal and annual movements of polar bears in the Beaufort Sea, 2) to define the boundaries of the population(s) using this region, 3) to determine the size and status of the Beaufort Sea polar bear population, and 4) to establish reproduction and survival rates (Amstrup 2000).
High energy physics with polarized beams and targets. [65 papers
Energy Technology Data Exchange (ETDEWEB)
Marshak, M L [ed.
1976-01-01
Sixty-six papers are presented as a report on conference sessions held from August 23-27, 1976, at Argonne National Laboratory. Topics covered include: (1) strong interactions; (2) weak and electromagnetic interactions; (3) polarized beams; and (4) polarized targets. A separate abstract was prepared for each paper for ERDA Energy Research Abstracts (ERA) and for the INIS Atomindex. (PMA)
Electromagnetic characteristics of carbon nanotube film materials
Directory of Open Access Journals (Sweden)
Zhang Wei
2015-08-01
Full Text Available Carbon nanotube (CNT possesses remarkable electrical conductivity, which shows great potential for the application as electromagnetic shielding material. This paper aims to characterize the electromagnetic parameters of a high CNT loading film by using waveguide method. The effects of layer number of CNT laminate, CNT alignment and resin impregnation on the electromagnetic characteristics were analyzed. It is shown that CNT film exhibits anisotropic electromagnetic characteristic. Pristine CNT film shows higher real part of complex permittivity, conductivity and shielding effectiveness when the polarized direction of incident wave is perpendicular to the winding direction of CNT film. For the CNT film laminates, complex permittivity increases with increasing layer number, and correspondingly, shielding effectiveness decreases. The five-layer CNT film shows extraordinary shielding performance with shielding effectiveness ranging from 67 dB to 78 dB in X-band. Stretching process induces the alignment of CNTs. When aligned direction of CNTs is parallel to the electric field, CNT film shows negative permittivity and higher conductivity. Moreover, resin impregnation into CNT film leads to the decrease of conductivity and shielding effectiveness. This research will contribute to the structural design for the application of CNT film as electromagnetic shielding materials.
Electromagnetic ultrasonic guided waves
Huang, Songling; Li, Weibin; Wang, Qing
2016-01-01
This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.
Electromagnetic wave matching device
International Nuclear Information System (INIS)
Hirata, Yosuke; Mitsunaka, Yoshika; Hayashi, Ken-ichi; Ito, Yasuyuki.
1997-01-01
The present invention provides a matching device capable of increasing an efficiency of combining beams of electromagnetic waves outputted from an output window of a gyrotron which is expected for plasma heating of a thermonuclear reactor and an electromagnetic wave transmission system as high as possible. Namely, an electromagnetic wave matching device reflects beams of electromagnetic waves incident from an inlet by a plurality of phase correction mirrors and combines them to an external transmission system through an exit. In this case, the phase correction mirrors change the phase of the beams of electromagnetic waves incident to the phase correction mirrors by a predetermined amount corresponding to the position of the reflection mirrors. Then, the beams of electromagnetic waves outputted, for example, from a gyrotron can properly be shaped as desired for the intensity and the phase. As a result, combination efficiency with the transmission system can be increased. (I.S.)
Electromagnetic Gowdy universe
International Nuclear Information System (INIS)
Charach, C.
1979-01-01
Following Gowdy and Berger we construct an inhomogeneous closed electromagnetic universe with three-torus topology. This model is obtained as a result of the homogeneity breaking in the electromagnetic Bianchi type-I universe and contains interacting gravitational and electromagnetic waves. This cosmological solution provides an exactly solvable model for the study of the nonlinear fully relativistic regime of coupled electromagnetic and gravitational fields in the early universe. The asymptotic behavior is considered (i) in the vicinity of the initial singularity and (ii) in the high-frequency limit. It is shown that the effects of coupling between electromagnetic and gravitational waves cause an evolution which is significantly different from that of the vacuum model. The influence of the primordial homogeneous electromagnetic field on the dynamics of the model is also discussed
Basic Electromagnetism and Materials
Moliton, André
2007-01-01
Basic Electromagnetism and Materials is the product of many years of teaching basic and applied electromagnetism. This textbook can be used to teach electromagnetism to a wide range of undergraduate science majors in physics, electrical engineering or materials science. However, by making lesser demands on mathematical knowledge than competing texts, and by emphasizing electromagnetic properties of materials and their applications, this textbook is uniquely suited to students of materials science. Many competing texts focus on the study of propagation waves either in the microwave or optical domain, whereas Basic Electromagnetism and Materials covers the entire electromagnetic domain and the physical response of materials to these waves. Professor André Moliton is Director of the Unité de Microélectronique, Optoélectronique et Polymères (Université de Limoges, France), which brings together three groups studying the optoelectronics of molecular and polymer layers, micro-optoelectronic systems for teleco...
Applications of the electromagnetic Helmholtz resonator*
Stoneback, Russell Alan
An electromagnetic Helmholtz resonator comprised of a capacitor with an aperture is investigated theoretically and experimentally. It is proposed that this resonance may be described using effective impedances describing the capacitor and aperture, similar to lumped element descriptions of the acoustic Helmholtz resonator. The dipole impedance of an electromagnetic aperture is derived and verified using the finite element method. Incorporating standard network relations, the aperture impedance can be used to calculate radiated power. Measurements of a capacitor demonstrates that the transmitted voltage through the capacitor is modified by induced charges. An induced voltage is introduced, and predictions agree with observations. Measurements of a capacitor with an aperture in the grounded plate indicate that induced currents cancel the imaginary impedance of the aperture, and double the real impedance. The observed impedance is close to predictions using the derived aperture impedance, confirming the utility of the aperture impedance in describing the system. The numerically obtained aperture electromagnetic fields are similar to the Birkeland current distribution and the cross polar cap potential in the Earth's polar ionosphere, motivating a model where the polar ionosphere is treated as an effective aperture. It is proposed that this effective aperture interacts with the capacitor formed between the Earth and ionosphere, creating an electromagnetic Helmholtz resonator. Predictions made with this model agree with measurements of transmitted power and phase velocity by FAST during a geomagnetic substorm, measurements of the Ionospheric Alfven Resonator, and oscillations recorded by ground based magnetometers. The same effective aperture behavior is expected in sunspots and polar coronal holes. A peak is predicted in Alfven wave power across the transition region for waves with a 5 min. period that delivers an average power over 100 W/m2 to the corona, sufficient to
Large In-Plane and Vertical Piezoelectricity in Janus Transition Metal Dichalchogenides.
Dong, Liang; Lou, Jun; Shenoy, Vivek B
2017-08-22
Piezoelectricity in 2D van der Waals materials has received considerable interest because of potential applications in nanoscale energy harvesting, sensors, and actuators. However, in all the systems studied to date, strain and electric polarization are confined to the basal plane, limiting the operation of piezoelectric devices. In this paper, based on ab initio calculations, we report a 2D materials system, namely, the recently synthesized Janus MXY (M = Mo or W, X/Y = S, Se, or Te) monolayer and multilayer structures, with large out-of-plane piezoelectric polarization. For MXY monolayers, both strong in-plane and much weaker out-of-plane piezoelectric polarizations can be induced by a uniaxial strain in the basal plane. For multilayer MXY, we obtain a very strong out-of-plane piezoelectric polarization when strained transverse to the basal plane, regardless of the stacking sequence. The out-of-plane piezoelectric coefficient d 33 is found to be strongest in multilayer MoSTe (5.7-13.5 pm/V depending on the stacking sequence), which is larger than that of the commonly used 3D piezoelectric material AlN (d 33 = 5.6 pm/V); d 33 in other multilayer MXY structures are a bit smaller, but still comparable. Our study reveals the potential for utilizing piezoelectric 2D materials and their van der Waals multilayers in device applications.
International Nuclear Information System (INIS)
Cai Xun-Ming
2015-01-01
Electromagnetically induced transparency and absorption of a monochromatic light controlled by a radio frequency field in the cold multi-Zeeman-sublevel atoms are theoretically investigated. These Zeeman sublevels are coupled by a radio frequency (RF) field. Both electromagnetically induced transparency and electromagnetically induced absorption can be obtained by tuning the frequency of RF field for both the linear polarization and elliptical polarization monochromatic lights. When the transfer of coherence via spontaneous emission from the excited state to the ground state is considered, electromagnetically induced absorption can be changed into electromagnetically induced transparency with the change of intensity of radio field. The transparency windows controlled by the RF field can have potential applications in the magnetic-field measurement and quantum information processing. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Model for Electromagnetic Information Leakage
Mao Jian; Li Yongmei; Zhang Jiemin; Liu Jinming
2013-01-01
Electromagnetic leakage will happen in working information equipments; it could lead to information leakage. In order to discover the nature of information in electromagnetic leakage, this paper combined electromagnetic theory with information theory as an innovative research method. It outlines a systematic model of electromagnetic information leakage, which theoretically describes the process of information leakage, intercept and reproduction based on electromagnetic radiation, and ana...
Characterization of Partially Polarized Light Fields
Martínez-Herrero, Rosario; Piquero, Gemma
2009-01-01
Polarization involves the vectorial nature of light fields. In current applications of optical science, the electromagnetic description of light with its vector features has been shown to be essential: In practice, optical radiation also exhibits randomness and spatial non-uniformity of the polarization state. Moreover, propagation through photonic devices can alter the correlation properties of the light field, resulting in changes in polarization. All these vectorial properties have been gaining importance in recent years, and they are attracting increasing attention in the literature. This is the framework and the scope of the present book, which includes the authors’ own contributions to these issues.
Electromagnetic Radiation Analysis
1978-04-10
A methodology is given for determining whether electromagnetic radiation of sufficient strength to cause performance degradation to the test item...exists at the test item location. The results of an electromagnetic radiation effects test are used to identify the radio frequencies and electromagnetic ... radiation levels to which the test item is susceptible. Further, using a test bed, comparisons are made with the representative signal levels to
Static electromagnetic frequency changers
Rozhanskii, L L
1963-01-01
Static Electromagnetic Frequency Changers is about the theory, design, construction, and applications of static electromagnetic frequency changers, devices that used for multiplication or division of alternating current frequency. It is originally published in the Russian language. This book is organized into five chapters. The first three chapters introduce the readers to the principles of operation, the construction, and the potential applications of static electromagnetic frequency changers and to the principles of their design. The two concluding chapters use some hitherto unpublished work
On scattering of electromagnetic waves by a wormhole
International Nuclear Information System (INIS)
Kirillov, A.A.; Savelova, E.P.
2012-01-01
We consider scattering of a plane electromagnetic wave by a wormhole. It is found that the scattered wave is depolarized and has a specific interference picture depending on parameters of the wormhole and the distance to the observer. It is proposed that such features can be important in the direct search of wormholes.
On scattering of electromagnetic waves by a wormhole
Energy Technology Data Exchange (ETDEWEB)
Kirillov, A.A., E-mail: ka98@mail.ru [Dubna International University of Nature, Society and Man, Universitetskaya Str. 19, Dubna, 141980 (Russian Federation); Savelova, E.P. [Dubna International University of Nature, Society and Man, Universitetskaya Str. 19, Dubna, 141980 (Russian Federation)
2012-04-20
We consider scattering of a plane electromagnetic wave by a wormhole. It is found that the scattered wave is depolarized and has a specific interference picture depending on parameters of the wormhole and the distance to the observer. It is proposed that such features can be important in the direct search of wormholes.
Correlated Electromagnetic Levitation Actuator
National Aeronautics and Space Administration — Approach is to first characterize the capabilities of correlated electromagnets by developing a prototype with readily available materials and manufacturing...
Electromagnetic Interface Testing Facility
Federal Laboratory Consortium — The Electromagnetic Interface Testing facilitysupports such testing asEmissions, Field Strength, Mode Stirring, EMP Pulser, 4 Probe Monitoring/Leveling System, and...
Ge, Jian; Dong, Haobin; Liu, Huan; Yuan, Zhiwen; Dong, He; Zhao, Zhizhuo; Liu, Yonghua; Zhu, Jun; Zhang, Haiyang
2016-01-01
Based on the dynamic nuclear polarization (DNP) effect, an alternative design of an Overhauser geomagnetic sensor is presented that enhances the proton polarization and increases the amplitude of the free induction decay (FID) signal. The short-pulse method is adopted to rotate the enhanced proton magnetization into the plane of precession to create an FID signal. To reduce the negative effect of the powerful electromagnetic interference, the design of the anti-interference of the pick-up coil is studied. Furthermore, the radio frequency polarization method based on the capacitive-loaded coaxial cavity is proposed to improve the quality factor of the resonant circuit. In addition, a special test instrument is designed that enables the simultaneous testing of the classical proton precession and the Overhauser sensor. Overall, comparison experiments with and without the free radical of the Overhauser sensors show that the DNP effect does effectively improve the amplitude and quality of the FID signal, and the magnetic sensitivity, resolution and range reach to 10 pT/Hz1/2@1 Hz, 0.0023 nT and 20–100 μT, respectively. PMID:27258283
Directory of Open Access Journals (Sweden)
Jian Ge
2016-06-01
Full Text Available Based on the dynamic nuclear polarization (DNP effect, an alternative design of an Overhauser geomagnetic sensor is presented that enhances the proton polarization and increases the amplitude of the free induction decay (FID signal. The short-pulse method is adopted to rotate the enhanced proton magnetization into the plane of precession to create an FID signal. To reduce the negative effect of the powerful electromagnetic interference, the design of the anti-interference of the pick-up coil is studied. Furthermore, the radio frequency polarization method based on the capacitive-loaded coaxial cavity is proposed to improve the quality factor of the resonant circuit. In addition, a special test instrument is designed that enables the simultaneous testing of the classical proton precession and the Overhauser sensor. Overall, comparison experiments with and without the free radical of the Overhauser sensors show that the DNP effect does effectively improve the amplitude and quality of the FID signal, and the magnetic sensitivity, resolution and range reach to 10 pT/Hz 1 / 2 @1 Hz, 0.0023 nT and 20–100 μ T, respectively.
Ultrathin triple-band polarization-insensitive wide-angle compact metamaterial absorber
International Nuclear Information System (INIS)
Shang, Shuai; Yang, Shizhong; Tao, Lu; Yang, Lisheng; Cao, Hailin
2016-01-01
In this study, the design, realization, and characterization of an ultrathin triple-band polarization-insensitive wide-angle metamaterial absorber are reported. The metamaterial absorber comprises a periodic array of modified six-fold symmetric snowflake-shaped resonators with strip spiral line load, which is printed on a dielectric substrate backed by a metal ground plane. It is shown that the absorber exhibits three distinct near-unity absorption peaks, which are distributed across C, X, Ku bands, respectively. Owing to the six-fold symmetry, the absorber is insensitive to the polarization of the incident radiation. In addition, the absorber shows excellent absorption performance over wide oblique incident angles for both transverse electric and transverse magnetic polarizations. Simulated surface current and field distributions at the three absorption peaks are demonstrated to understand the absorption mechanism. Particularly, the absorption modes come from the fundamental and high-order dipole resonances. Furthermore, the experimental verification of the designed absorber is conducted, and the measured results are in reasonable agreement with the simulated ones. The proposed ultrathin (∼0.018λ 0 , λ 0 corresponding to the lowest peak absorption frequency) compact (0.168λ 0 ×0.168λ 0 corresponding to the area of a unit cell) absorber enables potential applications such as stealth technology, electromagnetic interference and spectrum identification.
Korol, Andrey V
2014-01-01
This book introduces and reviews both theory and applications of polarizational bremsstrahlung, i.e. the electromagnetic radiation emitted during collisions of charged particles with structured, thus polarizable targets, such as atoms, molecules and clusters. The subject, following the first experimental evidence a few decades ago, has gained importance through a number of modern applications. Thus, the study of several radiative mechanisms is expected to lead to the design of novel light sources, operating in various parts of the electromagnetic spectrum. Conversely, the analysis of the spectral and angular distribution of the photon emission constitutes a new tool for extracting information on the interaction of the colliding particles, and on their internal structure and dynamical properties. Last but not least, accurate quantitative descriptions of the photon emission processes determine the radiative energy losses of particles in various media, thereby providing essential information required f...
Electromagnetic scattering by underground targets using the cylindrical-wave approach
Frezza, Fabrizio; Pajewski, Lara; Ponti, Cristina; Schettini, Giuseppe
2010-05-01
The electromagnetic detection of buried cylindrical targets, as structures encountered in the inspection of archaeological sites, or pipes, conduits, and tunnels, has been recently addressed in several works. The development of techniques for investigating cylindrical inhomogeneities embedded in a dielectric medium, is a challenging topic also in several other applications, including non-destructive evaluation and testing in civil engineering, and medical imaging. Ground-penetrating radars (GPRs) are extremely useful in probing subsurface targets through electromagnetic waves. These tools solve an inverse problem, to estimate the electromagnetic properties of a target from field measurements. Different algorithms are employed to post-process the collected experimental data: most of them need a fast and accurate forward solver, to perform repeated evaluations of the scattered field due to known targets, and to be used in combination with some optimization techniques. In this paper, we present an efficient spectral-domain method that we developed for the solution of the two-dimensional electromagnetic plane-wave forward scattering by a finite set of perfectly-conducting or dielectric cylinders, buried in a dielectric half-space or in a finite-thickness slab. The technique is called Cylindrical-Wave Approach (CWA), because the field scattered by the targets is represented in terms of a superposition of cylindrical waves. Use is made of the plane-wave spectrum to take into account the interaction of such waves with the planar interfaces. Suitable reflected and transmitted cylindrical functions are defined; adaptive integration procedures of Gaussian type, together with acceleration algorithms, are employed for the numerical solution of the relevant spectral integrals. All the multiple-reflection phenomena are taken into account. The method may deal with both TM and TE polarization fields; it can be applied for arbitrary values of permittivity, radius, and depth, of the
Geometrical optics in the near field: local plane-interface approach with evanescent waves.
Bose, Gaurav; Hyvärinen, Heikki J; Tervo, Jani; Turunen, Jari
2015-01-12
We show that geometrical models may provide useful information on light propagation in wavelength-scale structures even if evanescent fields are present. We apply a so-called local plane-wave and local plane-interface methods to study a geometry that resembles a scanning near-field microscope. We show that fair agreement between the geometrical approach and rigorous electromagnetic theory can be achieved in the case where evanescent waves are required to predict any transmission through the structure.
North-south asymmetry of ultra-low-frequency oscillations of Earth's electromagnetic field
Guglielmi, Anatol; Klain, Boris; Potapov, Alexander
2017-12-01
In the paper, we present the result of an experimental study of north-south asymmetry of ultralow-frequency electromagnetic oscillations IPCL. This study is based on observations made at Mirny Observatory (Antarctica). IPCLs are excited in the dayside sector of the auroral oval in the range 3-10 min periods and represent one of the most powerful types of oscillations of Earth's magnetosphere. These oscillations were discovered in the 1970s during IPhE AS USSR polar expeditions organized by Prof. V.A. Troitskaya. We have shown that IPCL activity in Mirny depends on the inclination (north-south asymmetry) of interplanetary magnetic field (IMF) lines to the plane of the geomagnetic equator before the front of the magnetosphere. The result suggests a controlling exposure of IMF on the magnetospheric oscillations and gives rise to the hypothesis that IPCLs are forced oscillations of a nonlinear dynamical system whose major structural elements are dayside polar cusps. The paper is dedicated to the memory of Professor V.A. Troitskaya (1917-2010).
Ultrarelativistic electromagnetic pulses in plasmas
Ashour-Abdalla, M.; Leboeuf, J. N.; Tajima, T.; Dawson, J. M.; Kennel, C. F.
1981-01-01
The physical processes of a linearly polarized electromagnetic pulse of highly relativistic amplitude in an underdense plasma accelerating particles to very high energies are studied through computer simulation. An electron-positron plasma is considered first. The maximum momenta achieved scale as the square of the wave amplitude. This acceleration stops when the bulk of the wave energy is converted to particle energy. The pulse leaves behind as a wake a vacuum region whose length scales as the amplitude of the wave. The results can be explained in terms of a snow plow or piston-like action of the radiation on the plasma. When a mass ratio other than unity is chosen and electrostatic effects begin to play a role, first the ion energy increases faster than the electron energy and then the electron energy catches up later, eventually reaching the same value.
Compton Sources of Electromagnetic Radiation
Energy Technology Data Exchange (ETDEWEB)
Geoffrey Krafft,Gerd Priebe
2011-01-01
When a relativistic electron beam interacts with a high-field laser beam, intense and highly collimated electromagnetic radiation will be generated through Compton scattering. Through relativistic upshifting and the relativistic Doppler effect, highly energetic polarized photons are radiated along the electron beam motion when the electrons interact with the laser light. For example, X-ray radiation can be obtained when optical lasers are scattered from electrons of tens-of-MeV beam energy. Because of the desirable properties of the radiation produced, many groups around the world have been designing, building, and utilizing Compton sources for a wide variety of purposes. In this review article, we discuss the generation and properties of the scattered radiation, the types of Compton source devices that have been constructed to date, and the prospects of radiation sources of this general type. Due to the possibilities of producing hard electromagnetic radiation in a device that is small compared to the alternative storage ring sources, it is foreseen that large numbers of such sources may be constructed in the future.
Electromagnetic Radiation of Electrons in Periodic Structures
Potylitsyn, Alexander Petrovich
2011-01-01
Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation a...
Directory of Open Access Journals (Sweden)
L. Li
2018-04-01
Full Text Available The phase function and polarized phase function are important optical parameters, which describe scattering properties of atmospheric aerosol particles. Polarization of skylight induced by the scattering processes is sensitive to the scattering properties of aerosols. The Stokes parameters I, Q, U and the polarized radiance Lp of skylight measured by the CIMEL dual-polar sun-sky radiometer CE318- DP can be use to retrieve the phase function and polarized phase function, respectively. Two different observation geometries (i.e., the principal plane and almucantar are preformed by the CE318-DP to detect skylight polarization. Polarization of skylight depends on the illumination and observation geometries. For the same solar zenith angle, retrievals of the phase function and the polarized phase function are still affected by the observation geometry. The performance of the retrieval algorithm for the principal plane and almucantar observation geometries was assessed by the numerical experiments at two typical high and low sun’s positions (i.e. solar zenith angles are equal to 45° and 65°. Comparing the results for the principal plane and almucantar geometries, it is recommended to utilize the principal plane observations to retrieve the phase function when the solar zenith angle is small. The Stokes parameter U and the polarized radiance Lp from the almucantar observations are suggested to retrieve the polarized phase function, especially for short wavelength channels (e.g., 440 and 500 nm.
Classical electromagnetic radiation
Heald, Mark A
2012-01-01
Newly corrected, this highly acclaimed text is suitable for advanced physics courses. The author presents a very accessible macroscopic view of classical electromagnetics that emphasizes integrating electromagnetic theory with physical optics. The survey follows the historical development of physics, culminating in the use of four-vector relativity to fully integrate electricity with magnetism.
Electromagnetically Operated Counter
Goldberg, H D; Goldberg, M I
1951-12-18
An electromagnetically operated counter wherein signals to be counted are applied to cause stepwise rotation of a rotatable element which is connected to a suitable register. The mechanism involved consists of a rotatable armature having three spaced cores of magnetic material and a pair of diametrically opposed electromagnets with a suitable pulsing circuit to actuate the magnets.
Tunability enhanced electromagnetic wiggler
Schlueter, R.D.; Deis, G.A.
1992-03-24
The invention discloses a wiggler used in synchrotron radiation sources and free electron lasers, where each pole is surrounded by at least two electromagnetic coils. The electromagnetic coils are energized with different amounts of current to provide a wide tunable range of the on-axis magnetic flux density, while preventing magnetic saturation of the poles. 14 figs.
An Electromagnetic Beam Converter
DEFF Research Database (Denmark)
2009-01-01
The present invention relates to an electromagnetic beam converter and a method for conversion of an input beam of electromagnetic radiation having a bell shaped intensity profile a(x,y) into an output beam having a prescribed target intensity profile l(x',y') based on a further development...
High frequency electromagnetic dosimetry
Sánchez-Hernández, David A
2009-01-01
Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.
Introducing Electromagnetic Field Momentum
Hu, Ben Yu-Kuang
2012-01-01
I describe an elementary way of introducing electromagnetic field momentum. By considering a system of a long solenoid and line charge, the dependence of the field momentum on the electric and magnetic fields can be deduced. I obtain the electromagnetic angular momentum for a point charge and magnetic monopole pair partially through dimensional…
The Study of the Electromagnetic Shielding Properties of a Textile Material with Amorphous Microwire
Directory of Open Access Journals (Sweden)
RAU, M.
2011-02-01
Full Text Available The paper presents the results concerning the utilization of a new class of composite textile materials with electromagnetic properties and the possibility of their utilization in the production of electromagnetic field protective equipment. The experimental and theoretical results concerning the electromagnetic characterization of a new textile material with composite structure are presented also considering the following aspects: - evaluation of the possibilities to use amorphous magnetic microwires in electromagnetic shielding; - study of the electromagnetic properties of the composite textile material, especially the electromagnetic field shielding, reflection and polarization; - determination of the frequency range within which these properties can be used in the realization of materials for the protection against electromagnetic fields. The experimental results of a material sample and a phantom for applications are connected with shielding in the frequency range used in mobile communications.
International Nuclear Information System (INIS)
Guo Yu
2010-01-01
We study the interaction of a weak probe field, having two circular polarized components, i.e., σ - and σ + polarization, with an optically dense medium of four-level atoms in a double-Λ configuration, which is mediated by the electromagnetically induced transparency with a polarized control light with spatially inhomogeneous profile. We analyse the deflection of the polarized probe light and we find that we can selectively determine which circular component will be deflected after the polarized probe light enters the atom medium via adjusting the polarization and detuning of the control field. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Electromagnetic Fields and Public Health: Mobile Phones
... sheets Fact files Questions & answers Features Multimedia Contacts Electromagnetic fields and public health: mobile phones Fact sheet NÂ° ... Electromagnetic fields: base stations and wireless technologies Electromagnetic fields: electromagnetic ... research agenda for electromagnetic fields You ...
Coherent nonlinear electromagnetic response in twisted bilayer and ...
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics; Volume 83; Issue 4. Coherent nonlinear electromagnetic response in twisted bilayer and few-layer graphene ... These oscillations in the population and polarization at the Dirac point in -layer graphene are seen in the nth harmonic termin the external driving frequency.
Dixit, Avinash K.; Weibull, Jörgen W.
2007-01-01
Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality.
Dixit, Avinash K; Weibull, Jörgen W
2007-05-01
Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality.
Cosmology Large Angular Scale Surveyor (CLASS) Focal Plane Development
Chuss, D. T.; Ali, A.; Amiri, M.; Appel, J.; Bennett, C. L.; Colazo, F.; Denis, K. L.; Dünner, R.; Essinger-Hileman, T.; Eimer, J.; Fluxa, P.; Gothe, D.; Halpern, M.; Harrington, K.; Hilton, G.; Hinshaw, G.; Hubmayr, J.; Iuliano, J.; Marriage, T. A.; Miller, N.; Moseley, S. H.; Mumby, G.; Petroff, M.; Reintsema, C.; Rostem, K.; U-Yen, K.; Watts, D.; Wagner, E.; Wollack, E. J.; Xu, Z.; Zeng, L.
2016-08-01
The Cosmology Large Angular Scale Surveyor (CLASS) will measure the polarization of the Cosmic Microwave Background to search for and characterize the polarized signature of inflation. CLASS will operate from the Atacama Desert and observe ˜ 70 % of the sky. A variable-delay polarization modulator provides modulation of the polarization at ˜ 10 Hz to suppress the 1/ f noise of the atmosphere and enable the measurement of the large angular scale polarization modes. The measurement of the inflationary signal across angular scales that spans both the recombination and reionization features allows a test of the predicted shape of the polarized angular power spectra in addition to a measurement of the energy scale of inflation. CLASS is an array of telescopes covering frequencies of 38, 93, 148, and 217 GHz. These frequencies straddle the foreground minimum and thus allow the extraction of foregrounds from the primordial signal. Each focal plane contains feedhorn-coupled transition-edge sensors that simultaneously detect two orthogonal linear polarizations. The use of single-crystal silicon as the dielectric for the on-chip transmission lines enables both high efficiency and uniformity in fabrication. Integrated band definition has been implemented that both controls the bandpass of the single-mode transmission on the chip and prevents stray light from coupling to the detectors.
Cosmology Large Angular Scale Surveyor (CLASS) Focal Plane Development
Chuss, D. T.; Ali, A.; Amiri, M.; Appel, J.; Bennett, C. L.; Colazo, F.; Denis, K. L.; Dunner, R.; Essinger-Hileman, T.; Eimer, J.;
2015-01-01
The Cosmology Large Angular Scale Surveyor (CLASS) will measure the polarization of the Cosmic Microwave Background to search for and characterize the polarized signature of inflation. CLASS will operate from the Atacama Desert and observe approx.70% of the sky. A variable-delay polarization modulator provides modulation of the polarization at approx.10Hz to suppress the 1/f noise of the atmosphere and enable the measurement of the large angular scale polarization modes. The measurement of the inflationary signal across angular scales that spans both the recombination and reionization features allows a test of the predicted shape of the polarized angular power spectra in addition to a measurement of the energy scale of inflation. CLASS is an array of telescopes covering frequencies of 38, 93, 148, and 217 GHz. These frequencies straddle the foreground minimum and thus allow the extraction of foregrounds from the primordial signal. Each focal plane contains feedhorn-coupled transition-edge sensors that simultaneously detect two orthogonal linear polarizations. The use of single-crystal silicon as the dielectric for the on-chip transmission lines enables both high efficiency and uniformity in fabrication. Integrated band definition has been implemented that both controls the bandpass of the single-mode transmission on the chip and prevents stray light from coupling to the detectors.
The Low Temperature Corrections to the Casimir Force Between a Sphere and a Plane
Bordag, Michael; Pirozhenko, Irina G.
We calculate the low temperature corrections to the free energy for a sphere in front of a plane. First, the scalar field obeying Dirichet or Neumann boundary conditions is considered. Second, the electromagnetic field is studied, the sphere being perfectly conducting and being a dielectric ball with both, constant permittivity and permittivity of the plasma model.
Polarized particles for accelerator physicists
International Nuclear Information System (INIS)
Bell, J.S.
1975-01-01
These lectures deal in an elementary way with the concept of particle polarization and its behaviour in the presence of electromagnetic fields. The first part introduces the basic notions and essential equations in a purely phenomenological way, beginning with spin-1/2 particles and then extending the discussion to particles of arbitrary spin. Among the topics discussed are magnetic precession and the muon g-2 experiment. The second part begins with an introduction to non-relativistic wave mechanics, and then develops the quantum-theoretic interpretation of the phenomenological equations for particles with spin 1/2, 1, and higher. (Author)
International Nuclear Information System (INIS)
Takahashi, Kenji.
1994-01-01
As an electromagnetic shaft seal, there are disposed outwarding electromagnetic induction devices having generating power directing to an electroconductive fluid as an object of sealing, and inwarding electromagnetic induction device added coaxially. There are disposed elongate rectangular looped first coils having a predetermined inner diameter, second coils having the same shape and shifted by a predetermined pitch relative to the first coil and third coil having the same shape and shifted by a predetermined pitch relative to the second coil respectively each at a predetermined inner diameter of clearance to the outwarding electromagnetic induction devices and the inwarding electromagnetic induction device. If the inwarding electromagnetic induction device and the outwarding electromagnetic induction device are operated, they are stopped at a point that the generating power of the former is equal with the sum of the generating power of the latter and a differential pressure. When three-phase AC is charged to the first coil, the second coil and the third coil successively, a force is generated in the advancing direction of the magnetic field in the electroconductive fluid by the similar effect to that of a linear motor, and the seal is maintained at high reliability. Moreover, the limit for the rotational angle of the shaft is not caused. (N.H.)
DUAL POLARIZATION ANTENNA ARRAY WITH VERY LOW CROSS POLARIZATION AND LOW SIDE LOBES
DEFF Research Database (Denmark)
1997-01-01
formation of grating lobes are inhibited in selected directions of the radiation and cross polarization within the main lobe is suppressed at least 30 dB below the main lobe peak value. According to a preferred embodiment of the invention, the antenna elements of the antenna array comprise probe-fed patches......The present invention relates to an antenna array adapted to radiate or receive electromagnetic waves of one or two polarizations with very low cross polarization and low side lobes. An antenna array comprising many antenna elements, e.g. more than ten antenna elements, is provided in which...
Computer techniques for electromagnetics
Mittra, R
1973-01-01
Computer Techniques for Electromagnetics discusses the ways in which computer techniques solve practical problems in electromagnetics. It discusses the impact of the emergence of high-speed computers in the study of electromagnetics. This text provides a brief background on the approaches used by mathematical analysts in solving integral equations. It also demonstrates how to use computer techniques in computing current distribution, radar scattering, and waveguide discontinuities, and inverse scattering. This book will be useful for students looking for a comprehensive text on computer techni
Nonlinear surface electromagnetic phenomena
Ponath, H-E
1991-01-01
In recent years the physics of electromagnetic surface phenomena has developed rapidly, evolving into technologies for communications and industry, such as fiber and integrated optics. The variety of phenomena based on electromagnetism at surfaces is rich and this book was written with the aim of summarizing the available knowledge in selected areas of the field. The book contains reviews written by solid state and optical physicists on the nonlinear interaction of electromagnetic waves at and with surfaces and films. Both the physical phenomena and some potential applications are
Electromagnetic sinc Schell-model pulses in dispersive media
International Nuclear Information System (INIS)
Tang, Miaomiao; Zhao, Daomu; Zhu, Yingbin; Ang, Lay-Kee
2016-01-01
A class of random electromagnetic pulsed sources with sinc Schell-model correlations is introduced. Analytical formulas for the electromagnetic pulses generated by such pulsed sources propagating in dispersive media are derived. It is shown that the temporal intensity distribution of this new type of pulse exhibits unique propagation features, such as reshaping its average intensity from the initial Gaussian profile to a double-layer flat-top distribution at far field. The effects, arising from the source temporal coherent length and the dispersion coefficient, on the profiles of the temporal intensity distribution and the temporal degree of polarization are analyzed in detail. The results presented here demonstrate the potential of coherence modulation for pulse shaping applications. - Highlights: • We introduced a new class of random electromagnetic pulsed sources. • We derived its analytical formulas for the electromagnetic pulses in dispersive media. • It is shown that its temporal intensity distribution exhibits unique propagation features.
Tadpole diagrams in constant electromagnetic fields
Karbstein, Felix
2017-10-01
We show how all possible one-particle reducible tadpole diagrams in constant electromagnetic fields can be constructed from one-particle irreducible constant-field diagrams. The construction procedure is essentially algebraic and involves differentiations of the latter class of diagrams with respect to the field strength tensor and contractions with derivatives of the one-particle irreducible part of the Heisenberg-Euler effective Lagrangian in constant fields. Specific examples include the two-loop addendum to the Heisenberg-Euler effective action as well as a novel one-loop correction to the charged particle propagator in constant electromagnetic fields discovered recently. As an additional example, the approach devised in the present article is adopted to derive the tadpole contribution to the two-loop photon polarization tensor in constant fields for the first time.
Electromagnetic radiation from beam-plasma instabilities
Pritchett, P. L.; Dawson, J. M.
1983-01-01
A computer simulation is developed for the generation of electromagnetic radiation in an electron beam-plasma interaction. The plasma is treated as a two-dimensional finite system, and effects of a continuous nonrelativistic beam input are accounted for. Three momentum and three field components are included in the simulation, and an external magnetic field is excluded. EM radiation generation is possible through interaction among Langmuir oscillations, ion-acoustic waves, and the electromagnetic wave, producing radiation perpendicular to the beam. The radiation is located near the plasma frequency, and polarized with the E component parallel to the beam. The scattering of Langmuir waves caused by ion-acoustic fluctuations generates the radiation. Comparison with laboratory data for the three-wave interactions shows good agreement in terms of the radiation levels produced, which are small relative to the plasma thermal energy.
Polarized proton target with horizontal spin orientation
International Nuclear Information System (INIS)
Bunyatova, Eh.I.; Kiselev, Yu.F.; Kozlenko, N.G.
1988-01-01
Proton target, the polarization vector of which may be arbitrary oriented in horizontal plane relatively to the beam, is developed and tested. 70% value of polarization is obtained. 0.6 K temperature is acquired through 3 He pumping out continuous cycle. 1.2-propylene glycol - Cr(V) was used as working medium. Magnetic system is made in the form of Helmholtz sperconducting coils with working curren close to critical one. Target polarization is measured by NMR technique using original system of proton signal processing
Platform for Manipulating Polarization Modes Realized with Jones Vectors in MATHEMATICA
Directory of Open Access Journals (Sweden)
Yong-Dae Choi
2015-06-01
Full Text Available The fundamental conception in physics of the propagation of the electromagnetic wave polarization in matter is newly understood as the cardinal keyword in free-space quantum communication technology and cosmology in astrophysics. Interactive visualization of the propagation mechanism of polarized electromagnetism in a medium with its helicity has accordingly received attention from scientists exploiting the protocol of quantum key distribution (QKD to guarantee unconditional security in cryptography communication. We have provided a dynamic polarization platform for presenting the polarization modes of a transverse electromagnetic wave, converting the state of polarization through the arrangement of optical elements, using Jones vectors calculations in Methematica. The platform graphically simulates the mechanism of production and propagation of the polarized waves in a medium while satisfying Maxwell's equations.
In-plane charge fluctuations in bismuth-sulfide superconductors
Athauda, Anushika; Yang, Junjie; Lee, Seunghun; Mizuguchi, Yoshikazu; Deguchi, Keita; Takano, Yoshihiko; Miura, Osuke; Louca, Despina
2015-04-01
The local atomic structure of the new nonmagnetic superconducting system LaO1-xFxBiS2 is investigated using neutron diffraction and the pair density function analysis. Evidence for local charge fluctuations linked to a charge disproportionation of the Bi ions in the distorted lattice of superconducting LaO1-xFxBiS2 is presented. In-plane short-range distortions of sulfur atoms up to 0.3 Å in magnitude break site symmetry and create two distinct environments around Bi. Out-of-plane motion of apical sulfur brings it closer to the La-O/F doping layer with increasing x that may lead to a charge transfer conduit between the doping layers and the superconducting BiS2 planes. The mechanism for superconductivity may arise from the interplay between charge density fluctuations and an enhanced spin-orbit coupling suggested theoretically that induces spin polarization.
Effects of Pulse Electromagnetic Field on Corrosion Resistance of Al-5 % Cu Alloy
Wang, B.; Tang, L. D.; Qi, J. G.; Wang, J. Z.
2013-03-01
It was investigated that corrosion resistance of Al-5 % Cu alloy was influenced by pulse electromagnetic field (PEMF). The morphologies were observed by scanning election microscopy (SEM). The corrosion behaviors were investigated by potentiodynamic polarization tests and immersion tests. The results indicated that corrosion resistance of samples could be increased by using pulse electromagnetic field, moreover, the optimum parameter of pulse electromagnetic field in this experiment was showed as follows: 500 V, 3 Hz, 30 s. Decreasing the quantity of eutectic in grain boundaries and refining the grains were main causations for increasing corrosion resistance of Al-5 % Cu alloy with pulse electromagnetic field.
[Mechanisms of primary reception of electromagnetic waves of optical range].
Huliar, S O; Lymans'kyĭ, Iu P
2003-01-01
An existence of separate functional system of regulation of electromagnetic balance of organism has been substantiated and a working conception of light therapy has been formulated. As a basis, there is a possibility to use the acupuncture points for input of biologically necessary electromagnetic waves into the system of their conductors in a body that might be considered as a transport facility for energy of the polarized electromagnetic waves. Zones-recipients are organs having an electromagnetic disbalance due to excess of biologically inadequate radiation and being the targets for peroxide oxidation. Foremost, a body has the neurohormonal and immune regulatory systems. Electromagnetic stimulation or modification of functions of the zones-recipients determines the achievement of therapeutic and useful effects, and their combination with local reparative processes allows to attain a clinical goal. We represent own and literary experimental data about the development of physiological responses (analgesia) to BIOPTRON-light exposure on the acupuncture points or biologically active zones. We show the experimental facts in support of a hypothesis that a living organism can perceive an action of the electromagnetic fields of optical range not only via the visual system, but also through the off-nerve receptors (specific energy-sensitive proteins detecting critical changes of energy in cells and functioning as the "sensory" cell systems), as well as via the acupuncture points. It confirms an important role of the electromagnetic waves of optical range in providing normal vital functions of living organisms. A current approach to BIOPTRON light therapy (by polarized polychromatic coherent low energy light) consists in combined (local and system) exposure of the electromagnetic waves within the biologically necessary range.
Broadband Electromagnetic Technology
2011-06-23
The objectives of this project are to continue the enhancements to the combined Broadband Electromagnetic and Full Encirclement Unit (BEM-FEU) technologies and to evaluate the systems capability in the laboratory and the field. The BEM instrument ...
Computational electromagnetic-aerodynamics
Shang, Joseph J S
2016-01-01
Presents numerical algorithms, procedures, and techniques required to solve engineering problems relating to the interactions between electromagnetic fields, fluid flow, and interdisciplinary technology for aerodynamics, electromagnetics, chemical-physics kinetics, and plasmadynamics This book addresses modeling and simulation science and technology for studying ionized gas phenomena in engineering applications. Computational Electromagnetic-Aerodynamics is organized into ten chapters. Chapter one to three introduce the fundamental concepts of plasmadynamics, chemical-physics of ionization, classical magnetohydrodynamics, and their extensions to plasma-based flow control actuators, high-speed flows of interplanetary re-entry, and ion thrusters in space exploration. Chapter four to six explain numerical algorithms and procedures for solving Maxwell’s equation in the time domain for computational electromagnetics, plasma wave propagation, and the time-dependent c mpressible Navier-Stokes equation for aerodyn...
Electromagnetism in the Movies.
Everitt, Lori R.; Patterson, Evelyn T.
1999-01-01
Describes how the authors used portions of popular movies to help students review concepts related to electromagnetism. Movies used and concepts covered in the review are listed, and a sample activity is described. (WRM)
Purely electromagnetic spacetimes
Ivanov, B. V.
2007-01-01
Electrovacuum solutions devoid of usual mass sources are classified in the case of one, two and three commuting Killing vectors. Three branches of solutions exist. Electromagnetically induced mass terms appear in some of them.
The classical electromagnetic field
Eyges, Leonard
2010-01-01
This excellent text covers a year's course in advanced theoretical electromagnetism, first introducing theory, then its application. Topics include vectors D and H inside matter, conservation laws for energy, momentum, invariance, form invariance, covariance in special relativity, and more.
Electromagnetic Manifestation of Earthquakes
Uvarov Vladimir
2017-01-01
In a joint analysis of the results of recording the electrical component of the natural electromagnetic field of the Earth and the catalog of earthquakes in Kamchatka in 2013, unipolar pulses of constant amplitude associated with earthquakes were identified, whose activity is closely correlated with the energy of the electromagnetic field. For the explanation, a hypothesis about the cooperative character of these impulses is proposed.
Electromagnetic Manifestation of Earthquakes
Directory of Open Access Journals (Sweden)
Uvarov Vladimir
2017-01-01
Full Text Available In a joint analysis of the results of recording the electrical component of the natural electromagnetic field of the Earth and the catalog of earthquakes in Kamchatka in 2013, unipolar pulses of constant amplitude associated with earthquakes were identified, whose activity is closely correlated with the energy of the electromagnetic field. For the explanation, a hypothesis about the cooperative character of these impulses is proposed.
The ATLAS electromagnetic calorimeter
Maximilien Brice
2003-01-01
Michel Mathieu, a technician for the ATLAS collaboration, is cabling the ATLAS electromagnetic calorimeter's first end-cap, before insertion into its cryostat. Millions of wires are connected to the electromagnetic calorimeter on this end-cap that must be carefully fed out from the detector so that data can be read out. Every element on the detector will be attached to one of these wires so that a full digital map of the end-cap can be recreated.
Electromagnetic Education in India
Directory of Open Access Journals (Sweden)
Bajpai Shrish
2016-06-01
Full Text Available Out of the four fundamental interactions in nature, electromagnetics is one of them along with gravitation, strong interaction and weak interaction. The field of electromagnetics has made much of the modern age possible. Electromagnets are common in day-to-day appliances and are becoming more conventional as the need for technology increases. Electromagnetism has played a vital role in the progress of human kind ever since it has been understood. Electromagnets are found everywhere. One can find them in speakers, doorbells, home security systems, anti-shoplifting systems, hard drives, mobiles, microphones, Maglev trains, motors and many other everyday appliances and products. Before diving into the education system, it is necessary to reiterate its importance in various technologies that have evolved over time. Almost every domain of social life has electromagnetic playing its role. Be it the mobile vibrators you depend upon, a water pump, windshield wipers during rain and the power windows of your car or even the RFID tags that may ease your job during shopping. A flavor of electromagnetics is essential during primary level of schooling for the student to understand its future prospects and open his/her mind to a broad ocean of ideas. Due to such advancements this field can offer, study on such a field is highly beneficial for a developing country like India. The paper presents the scenario of electromagnetic education in India, its importance and numerous schemes taken by the government of India to uplift and acquaint the people about the importance of EM and its applications.
Electromagnetic reverberation chambers
Besnier, Philippe
2013-01-01
Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc
Electromagnetic rotational actuation.
Energy Technology Data Exchange (ETDEWEB)
Hogan, Alexander Lee
2010-08-01
There are many applications that need a meso-scale rotational actuator. These applications have been left by the wayside because of the lack of actuation at this scale. Sandia National Laboratories has many unique fabrication technologies that could be used to create an electromagnetic actuator at this scale. There are also many designs to be explored. In this internship exploration of the designs and fabrications technologies to find an inexpensive design that can be used for prototyping the electromagnetic rotational actuator.
Grid computing for electromagnetics
Tarricone, Luciano
2004-01-01
Today, more and more practitioners, researchers, and students are utilizing the power and efficiency of grid computing for their increasingly complex electromagnetics applications. This cutting-edge book offers you the practical and comprehensive guidance you need to use this new approach to supercomputing for your challenging projects. Supported with over 110 illustrations, the book clearly describes a high-performance, low-cost method to solving huge numerical electromagnetics problems.
Grazing incidence polarized neutron scattering in reflection ...
Indian Academy of Sciences (India)
During the year 1980, polarized neutron scattering technique came into being as an ana- lytic tool to measure the ... The discovery of antiferromagnetic coupling was critical to the discovery of GMR, pro- viding as it did ..... Here we consider the incident wave vector ki making an angle αi in the x–z plane while the scattered ...
Electromagnetic cellular interactions.
Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan
2011-05-01
Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating. Copyright © 2010 Elsevier Ltd. All rights reserved.
Electromagnetic processes and interactions
International Nuclear Information System (INIS)
Scheck, F.
1983-01-01
The electron and muon are important tools in testing the structure of the fundamental electromagnetic interactions. On the other hand, if these interactions are known, they serve as ideal probes for the internal structure of complex hadronic targets such as nucleons and nuclei. Purely electromagnetic interactions play a distinctive role, for obvious experimental reasons: At low and intermediate energies the effective electromagnetic coupling is larger by many orders of magnitude than the weak couplings, so that electromagnetic processes are measurable to much higher accuracy than purely weak processes. The present chapter deals primarily with applications of charged leptons to problems of nucleon and nuclear structure, and to selected precision tests of quantum electrodynamics (QED) at low momentum transfers. In most of these applications the electromagnetic interactions effectively appear in the form of external fields in the leptonic particle's Dirac equation. This is the domain where the physics of (electromagnetically) interacting leptons can still be described in the framework of an effective, though relativistic, single particle theory. (orig.)
Covariant electromagnetic field lines
Hadad, Y.; Cohen, E.; Kaminer, I.; Elitzur, A. C.
2017-08-01
Faraday introduced electric field lines as a powerful tool for understanding the electric force, and these field lines are still used today in classrooms and textbooks teaching the basics of electromagnetism within the electrostatic limit. However, despite attempts at generalizing this concept beyond the electrostatic limit, such a fully relativistic field line theory still appears to be missing. In this work, we propose such a theory and define covariant electromagnetic field lines that naturally extend electric field lines to relativistic systems and general electromagnetic fields. We derive a closed-form formula for the field lines curvature in the vicinity of a charge, and show that it is related to the world line of the charge. This demonstrates how the kinematics of a charge can be derived from the geometry of the electromagnetic field lines. Such a theory may also provide new tools in modeling and analyzing electromagnetic phenomena, and may entail new insights regarding long-standing problems such as radiation-reaction and self-force. In particular, the electromagnetic field lines curvature has the attractive property of being non-singular everywhere, thus eliminating all self-field singularities without using renormalization techniques.
A test of the equivalence principle with polarized light
International Nuclear Information System (INIS)
Lesche, B.; Bedran, M.L.
1987-01-01
The behaviour of electromagnetic radiation in the Schwarzschild metric of the sun is studied with the presence of a non-minimal coupling term of electromagnetism and gravity. An anomalous deflection is predicted, as well as a polarization effect. These effects can be used to obtain experimental upper bounds for the coupling constant of the non-minimal coupling. The strength of these upper bounds is discussed. (author) [pt
Vacuum polarization of massless fields in black holes
International Nuclear Information System (INIS)
Zel'nikov, A.I.; Frolov, V.P.
1987-01-01
This chapter contains a detailed survey of the fundamental results from an investigation of the contribution of massless fields to vacuum polarization near black holes. A method is developed for calculating the vacuum average energy-momentum tensor for the electromagnetic field on the surface of a black hole. An explicit value is derived for the renormalized energy-momentum tensor of an electromagnetic field near the event horizon of a rotating black hole
Detecting Spin-Polarized Currents in Ballistic Nanostructures
DEFF Research Database (Denmark)
Potok, R.; Folk, J.; M. Marcus, C.
2002-01-01
We demonstrate a mesoscopic spin polarizer/analyzer system that allows the spin polarization of current from a quantum point contact in an in-plane magnetic field to be measured. A transverse focusing geometry is used to couple current from an emitter point contact into a collector point contact....
Transition operators in electromagnetic-wave diffraction theory - General theory
Hahne, G. E.
1992-01-01
A formal theory is developed for the scattering of time-harmonic electromagnetic waves from impenetrable immobile obstacles with given linear, homogeneous, and generally nonlocal boundary conditions of Leontovich (impedance) type for the wave of the obstacle's surface. The theory is modeled on the complete Green's function and the transition (T) operator in time-independent formal scattering theory of nonrelativistic quantum mechanics. An expression for the differential scattering cross section for plane electromagnetic waves is derived in terms of certain matrix elements of the T operator for the obstacle.
Dispersion properties of transverse waves in electrically polarized BECs
International Nuclear Information System (INIS)
Andreev, Pavel A; Kuz'menkov, L S
2014-01-01
Further development of the method of quantum hydrodynamics in applications for Bose–Einstein condensates (BECs) is presented. To consider the evolution of polarization direction along with particle movement, we have developed a corresponding set of quantum hydrodynamic equations. It includes equations of the polarization evolution and the polarization-current evolution along with the continuity equation and the Euler equation (the momentum-balance equation). Dispersion properties of the transverse waves, including the electromagnetic waves propagating through the BECs, are considered. To this end, we consider a full set of the Maxwell equations for the description of electromagnetic field dynamics. This approximation gives us the possibility of considering the electromagnetic waves along with the matter waves. We find a splitting of the electromagnetic-wave dispersion on two branches. As a result, we have four solutions, two for the electromagnetic waves and two for the matter waves; the last two are the concentration-polarization waves appearing as a generalization of the Bogoliubov mode. We also find that if the matter wave propagates perpendicular to the external electric field then the dipolar contribution does not disappear (as it follows from our generalization of the Bogoliubov spectrum). A small dipolar frequency shift exists in this case due to the transverse electric field of perturbation. (paper)
Properties of a Variable-Delay Polarization Modulator
Chuss, David T.; Wollack, Edward J.; Henry, Ross; Hui, Howard; Juarez, Aaron J.; Krenjy, Megan; Moseley, Harvey; Novak, Giles
2011-01-01
We investigate the polarization modulation properties of a variable-delay polarization modulator (VPM). The VPM modulates polarization via a variable separation between a polarizing grid and a parallel mirror. We find that in the limit where the wavelength is much larger than the diameter of the metal wires that comprise the grid, the phase delay derived from the geometric separation between the mirror and the grid is sufficient to characterize the device. However, outside of this range, additional parameters describing the polarizing grid geometry must be included to fully characterize the modulator response. In this paper, we report test results of a VPM at wavelengths of 350 micron and 3 mm. Electromagnetic simulations of wire grid polarizers were performed and are summarized using a simple circuit model that incorporates the loss and polarization properties of the device.
Controlling vortex chirality and polarity by geometry in magnetic nanodots
Agramunt Puig, Sebastià
2014-01-01
The independent control of both vortex chirality and polarity is a significant challenge in magnetic devices based on nano-sized magnetic vortex structures. By micromagnetic simulations here, we show that in soft ferromagnetic nanodots with an adequate modulated thickness, the desired combination of chirality and polarity can be achieved just by changing the direction of the in-plane applied magnetic field. Despite the complex behavior, the vortex chirality and polarity control can be summari...
Di Gregorio, Pietro Paolo; Frezza, Fabrizio; Mangini, Fabio; Pajewski, Lara
2017-04-01
The electromagnetic scattered field by a reinforced concrete structure is calculated by means of frequency-domain numerical simulations and by making use of the scattered-field formulation. The concrete pillar, used as supporting architectural element, is modelled as a parallelepiped shell made of concrete material inside which are present steel bars. In order to make the model simpler, the steel bars are supposed running parallel to the air-pillar interface. To excite the model, a linearly-polarized plane wave impinging normally with respect to the pillars surface, is adopted. We consider two different polarizations in order to determine the most useful in terms of scattered-field sensitivity. Moreover, a preliminary frequency sweep allows us to choose the most suitable operating frequency depending on the dimensions of the pillar cross-section, the steel bars cross-section and the concrete cover. All the three components of the scattered field are monitored along a line just above the interface air-pillar. The electromagnetic properties of the materials employed in this study are present in the literature and, since a frequency-domain technique is adopted, no further approximation is needed. The results obtained for different values of the concrete cover are compared, with the goal of determining the scattered field dependence on the concrete cover thickness. Considering different concrete cover thicknesses, we want to provide an electromagnetic method to obtain this useful parameter by observation of the scattered electromagnetic field. One of the practical applications of this study in the field of Civil Engineering may be the use of ground penetrating radar (GPR) techniques to monitor the thickness of the concrete that separates the metal bars embedded in the pillar from the outer surface. A correct distance is useful because the concrete cover serves as a protection against external agents avoiding corrosion of the bars that might prejudice the reinforced
Kalai, Adam; Kalai, Ehud
2001-08-01
In joint decision making, similarly minded people may take opposite positions. Consider the example of a marriage in which one spouse gives generously to charity while the other donates nothing. Such "polarization" may misrepresent what is, in actuality, a small discrepancy in preferences. It may be that the donating spouse would like to see 10% of their combined income go to charity each year, while the apparently frugal spouse would like to see 8% donated. A simple game-theoretic analysis suggests that the spouses will end up donating 10% and 0%, respectively. By generalizing this argument to a larger class of games, we provide strategic justification for polarization in many situations such as debates, shared living accommodations, and disciplining children. In some of these examples, an arbitrarily small disagreement in preferences leads to an arbitrarily large loss in utility for all participants. Such small disagreements may also destabilize what, from game-theoretic point of view, is a very stable equilibrium. Copyright 2001 Academic Press.
Electromagnetic fields and their impacts
Prša, M. A.; Kasaš-Lažetić, K. K.
2018-01-01
The main goal of this paper is to briefly recall some different electromagnetic field definitions, some macroscopic sources of electromagnetic fields, electromagnetic fields classification regarding time dependences, and the ways of field determination in concrete cases. After that, all the mechanisms of interaction between electromagnetic field and substance, on atomic level, are described in details. Interaction between substance and electric field is investigated separately from the substance and magnetic field interaction. It is demonstrated that, in all cases of the unique electromagnetic field, total interaction can be treated as a superposition of two separated interactions. Finally, the main electromagnetic fields surrounding us is cited and discussed.
Error Analysis on Plane-to-Plane Linear Approximate Coordinate ...
Indian Academy of Sciences (India)
Abstract. In this paper, the error analysis has been done for the linear approximate transformation between two tangent planes in celestial sphere in a simple case. The results demonstrate that the error from the linear transformation does not meet the requirement of high-precision astrometry under some conditions, so the ...
Error Analysis on Plane-to-Plane Linear Approximate Coordinate ...
Indian Academy of Sciences (India)
2016-01-27
Jan 27, 2016 ... In this paper, the error analysis has been done for the linear approximate transformation between two tangent planes in celestial sphere in a simple case. The results demonstrate that the error from the linear transformation does not meet the requirement of high-precision astrometry under some conditions, ...
Na, Dong-Yeop; Omelchenko, Yuri A.; Moon, Haksu; Borges, Ben-Hur V.; Teixeira, Fernando L.
2017-10-01
We present a charge-conservative electromagnetic particle-in-cell (EM-PIC) algorithm optimized for the analysis of vacuum electronic devices (VEDs) with cylindrical symmetry (axisymmetry). We exploit the axisymmetry present in the device geometry, fields, and sources to reduce the dimensionality of the problem from 3D to 2D. Further, we employ 'transformation optics' principles to map the original problem in polar coordinates with metric tensor diag (1 ,ρ2 , 1) to an equivalent problem on a Cartesian metric tensor diag (1 , 1 , 1) with an effective (artificial) inhomogeneous medium introduced. The resulting problem in the meridian (ρz) plane is discretized using an unstructured 2D mesh considering TEϕ-polarized fields. Electromagnetic field and source (node-based charges and edge-based currents) variables are expressed as differential forms of various degrees, and discretized using Whitney forms. Using leapfrog time integration, we obtain a mixed E - B finite-element time-domain scheme for the full-discrete Maxwell's equations. We achieve a local and explicit time update for the field equations by employing the sparse approximate inverse (SPAI) algorithm. Interpolating field values to particles' positions for solving Newton-Lorentz equations of motion is also done via Whitney forms. Particles are advanced using the Boris algorithm with relativistic correction. A recently introduced charge-conserving scatter scheme tailored for 2D unstructured grids is used in the scatter step. The algorithm is validated considering cylindrical cavity and space-charge-limited cylindrical diode problems. We use the algorithm to investigate the physical performance of VEDs designed to harness particle bunching effects arising from the coherent (resonance) Cerenkov electron beam interactions within micro-machined slow wave structures.
Directory of Open Access Journals (Sweden)
Mario Cvetković
2017-01-01
Full Text Available The paper presents the numerical results for the induced electric field in the various models of the human eye and the head. The comparison between the extracted or the single organ models and the compound organ models placed inside realistic head models obtained from the magnetic resonance imaging scans is presented. The numerical results for several frequencies and polarizations of the incident electromagnetic (EM plane wave are obtained using the hybrid finite element method/boundary element method (FEM/BEM formulation and the surface integral equation (SIE based formulation featuring the use of method of moments, respectively. Although some previous analysis showed the similar distribution of the induced electric field along the pupillary axis obtained in both eye models, this study showed this not to be the case in general. The analysis showed that the compound eye model is much more suitable when taking into account the polarization of the incident EM wave. The numerical results for the brain models showed much better agreement in the maximum values and distributions of the induced surface field between detailed models, while homogeneous brain model showed better agreement with the compound model in the distribution along selected sagittal axis points. The analysis could provide some helpful insights when carrying out the dosimetric analysis of the human eye and the head/brain exposed to high frequency EM radiation.
International Nuclear Information System (INIS)
Merriam, J.D.
1988-01-01
Problems associated with the testing of focal plane arrays are briefly examined with reference to the instrumentation and measurement procedures. In particular, the approach and instrumentation used as the Naval Ocean Systems Center is presented. Most of the measurements are made with flooded illumination on the focal plane array. The array is treated as an ensemble of individual pixels, data being taken on each pixel and array averages and standard deviations computed for the entire array. Data maps are generated, showing the pixel data in the proper spatial position on the array and the array statistics
Algebraic Methods in Plane Geometry
Indian Academy of Sciences (India)
user
a 6= 1, c 6= 1; then f ± g(z) = acz + ad + b. T he fact th a t jacj = 1,and the presence of z rath er th an z, ... alldisplacem ents in the plane;this is essentially the ad- ditive group of all vectors in the plane. In fact, D is ..... ro ta tio n s fa ;fb;fc as follow s: fa = R A ;® , fb = R B ;¯ , fc = R C ;° . A ssum e that the vertices of 4 A B C are ...
Plane waves in noncommutative fluids
Energy Technology Data Exchange (ETDEWEB)
Abdalla, M.C.B., E-mail: mabdalla@ift.unesp.br [Instituto de Física Teórica, UNESP, Universidade Estadual Paulista, Rua Dr. Bento Teobaldo Ferraz 271, Bloco 2, Barra-Funda, Caixa Postal 70532-2, 01156-970, São Paulo, SP (Brazil); Holender, L., E-mail: holender@ufrrj.br [Grupo de Física Teórica e Matemática Física, Departamento de Física, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Cx. Postal 23851, BR 465 Km 7, 23890-000 Seropédica, RJ (Brazil); Santos, M.A., E-mail: masantos@cce.ufes.br [Departamento de Física e Química, Universidade Federal do Espírito Santo (UFES), Avenida Fernando Ferarri S/N, Goiabeiras, 29060-900 Vitória, ES (Brazil); Vancea, I.V., E-mail: ionvancea@ufrrj.br [Grupo de Física Teórica e Matemática Física, Departamento de Física, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Cx. Postal 23851, BR 465 Km 7, 23890-000 Seropédica, RJ (Brazil)
2013-08-01
We study the dynamics of the noncommutative fluid in the Snyder space perturbatively at the first order in powers of the noncommutative parameter. The linearized noncommutative fluid dynamics is described by a system of coupled linear partial differential equations in which the variables are the fluid density and the fluid potentials. We show that these equations admit a set of solutions that are monochromatic plane waves for the fluid density and two of the potentials and a linear function for the third potential. The energy–momentum tensor of the plane waves is calculated.
International Nuclear Information System (INIS)
Wang, C.M.; Pang, M.Q.; Liu, S.Y.; Lei, X.L.
2010-01-01
The current-induced spin polarization (CISP) is investigated in a combined Rashba-Dresselhaus spin-orbit-coupled two-dimensional electron gas, subjected to a homogeneous out-of-plane magnetization. It is found that, in addition to the usual collision-related in-plane parts of CISP, there are two impurity-density-free contributions, arising from intrinsic and disorder-mediated mechanisms. The intrinsic parts of spin polarization are related to the Berry curvature, analogous with the anomalous and spin Hall effects. For short-range collision, the disorder-mediated spin polarizations completely cancel the intrinsic ones and the total in-plane components of CISP equal those for systems without magnetization. However, for remote disorders, this cancellation does not occur and the total in-plane components of CISP strongly depend on the spin-orbit interaction coefficients and magnetization for both pure Rashba and combined Rashba-Dresselhaus models.
Kostogryz, N. M.; Yakobchuk, T. M.; Berdyugina, S. V.; Milic, I.
2017-05-01
Context. To properly interpret photometric and polarimetric observations of exoplanetary transits, accurate calculations of center-to-limb variations of intensity and linear polarization of the host star are needed. These variations, in turn, depend on the choice of geometry of stellar atmosphere. Aims: We want to understand the dependence of the flux and the polarization curves during a transit on the choice of the applied approximation for the stellar atmosphere: spherical and plane-parallel. We examine whether simpler plane-parallel models of stellar atmospheres are good enough to interpret the flux and the polarization light curves during planetary transits, or whether more complicated spherical models should be used. Methods: Linear polarization during a transit appears because a planet eclipses a stellar disk and thus breaks left-right symmetry. We calculate the flux and the polarization variations during a transit with given center-to-limb variations of intensity and polarization. Results: We calculate the flux and the polarization variations during transit for a sample of 405 extrasolar systems. Most of them show higher transit polarization for the spherical stellar atmosphere. Our calculations reveal a group of exoplanetary systems that demonstrates lower maximum polarization during the transits with spherical model atmospheres of host stars with effective temperatures of Teff = 4400-5400 K and surface gravity of log g = 4.45-4.65 than that obtained with plane-parallel atmospheres. Moreover, we have found two trends of the transit polarization. The first trend is a decrease in the polarization calculated with spherical model atmosphere of host stars with effective temperatures Teff = 3500-5100 K, and the second shows an increase in the polarization for host stars with Teff = 5100-7000 K. These trends can be explained by the relative variation of temperature and pressure dependences in the plane-parallel and spherical model atmospheres. Conclusions: For
Influence of gravitation on the propagation of electromagnetic radiation
Mashhoon, B.
1975-01-01
The existence of a general helicity-rotation coupling is demonstrated for electromagnetic waves propagating in the field of a slowly rotating body and in the Goedel universe. This coupling leads to differential focusing of circularly polarized radiation by a gravitational field which is detectable for a rapidly rotating collapsed body. The electromagnetic perturbations and their frequency spectrum are given for the Goedel universe. The spectrum of frequencies is bounded from below by the characteristic rotation frequency of the Goedel universe. If the universe were rotating, the differential focusing effect would be extremely small due to the present upper limit on the anisotropy of the microwave background radiation.
Seismic electromagnetic study in China
Huang, Qinghua
2016-04-01
Seismo-electromagnetism is becoming a hot interdisciplinary study in both geosciences and electromagnetism. Numerous electromagnetic changes at a broad range of frequencies associated with earthquakes have been reported independently. There are some attempts of applying such electromagnetic data to short-term earthquake prediction. Although due to the complexity of seismogenic process and underground structure, the seismic electromagnetic phenomena cannot be fully understood, the seismic electromagnetic study plays a key role in the mitigation of seismic hazard. China is one of the countries which have the earliest reports on seismo-electromagnetic phenomena. The seismic electromagnetic study in China started in late 1960's. There are almost 50 years continuous observation data up to now, which provides a unique database for seismo-electromagnetic study not only in China, but also in the world. Therefore, seismo-electromagnetic study in China is interested broadly by international communities of geosciences and electromagnetism. I present here a brief review on seismic electromagnetic study in China, especially focusing on geo-electromagnetic observation and empirical prediction based on the observation data. After summarizing various electromagnetic observations such as apparent resistivity, geoelectric potential, geomagnetic field, electromagnetic disturbance, and so on, I show the cases of the empirical prediction based on the observed electromagnetic data associated with some earthquakes in China. Finally, based on the above review, I propose an integrated research scheme of earthquake-related electromagnetic phenomena, which includes the interaction between appropriate observations, robust methodology of data processing, and theoretical model analysis. This study is supported partially by the National Natural Science Foundation of China (41274075) and the National Basic Research Program of China (2014CB845903).
Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation
Novack, Steven D.; Kotter, Dale K.; Pinhero, Patrick J.
2012-10-09
Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.
Structures, systems and methods for harvesting energy from electromagnetic radiation
Novack, Steven D [Idaho Falls, ID; Kotter, Dale K [Shelley, ID; Pinhero, Patrick J [Columbia, MO
2011-12-06
Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.
Aircraft electromagnetic compatibility
Clarke, Clifton A.; Larsen, William E.
1987-06-01
Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.
Applied electromagnetic scattering theory
Osipov, Andrey A
2017-01-01
Besides classical applications (radar and stealth, antennas, microwave engineering), scattering and diffraction are enabling phenomena for some emerging research fields (artificial electromagnetic materials or metamaterials, terahertz technologies, electromagnetic aspects of nano-science). This book is a tutorial for advanced students who need to study diffraction theory. The textbook gives fundamental knowledge about scattering and diffraction of electromagnetic waves and provides some working examples of solutions for practical high-frequency scattering and diffraction problems. The book focuses on the most important diffraction effects and mechanisms influencing the scattering process and describes efficient and physically justified simulation methods - physical optics (PO) and the physical theory of diffraction (PTD) - applicable in typical remote sensing scenarios. The material is presented in a comprehensible and logical form, which relates the presented results to the basic principles of electromag...
Metamaterial electromagnetic wave absorbers.
Watts, Claire M; Liu, Xianliang; Padilla, Willie J
2012-06-19
The advent of negative index materials has spawned extensive research into metamaterials over the past decade. Metamaterials are attractive not only for their exotic electromagnetic properties, but also their promise for applications. A particular branch-the metamaterial perfect absorber (MPA)-has garnered interest due to the fact that it can achieve unity absorptivity of electromagnetic waves. Since its first experimental demonstration in 2008, the MPA has progressed significantly with designs shown across the electromagnetic spectrum, from microwave to optical. In this Progress Report we give an overview of the field and discuss a selection of examples and related applications. The ability of the MPA to exhibit extreme performance flexibility will be discussed and the theory underlying their operation and limitations will be established. Insight is given into what we can expect from this rapidly expanding field and future challenges will be addressed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Electromagnetic compatibility engineering
Ott, Henry W
2009-01-01
Praise for Noise Reduction Techniques IN electronic systems ""Henry Ott has literally 'written the book' on the subject of EMC. . . . He not only knows the subject, but has the rare ability to communicate that knowledge to others.""-EE Times Electromagnetic Compatibility Engineering is a completely revised, expanded, and updated version of Henry Ott's popular book Noise Reduction Techniques in Electronic Systems. It reflects the most recent developments in the field of electromagnetic compatibility (EMC) and noise reduction¿and their practical applications t
Essentials of Computational Electromagnetics
Sheng, Xin-Qing
2012-01-01
Essentials of Computational Electromagnetics provides an in-depth introduction of the three main full-wave numerical methods in computational electromagnetics (CEM); namely, the method of moment (MoM), the finite element method (FEM), and the finite-difference time-domain (FDTD) method. Numerous monographs can be found addressing one of the above three methods. However, few give a broad general overview of essentials embodied in these methods, or were published too early to include recent advances. Furthermore, many existing monographs only present the final numerical results without specifyin
Electromagnetic clutches and couplings
Vorob'Yeva, T M; Fry, D W; Higinbotham, W
2013-01-01
Electromagnetic Clutches and Couplings contains a detailed description of U.S.S.R. electromagnetic friction clutches, magnetic couplings, and magnetic particle couplings. This book is divided into four chapters. The first chapter discusses the design and construction of magnetic (solenoid-operated) couplings, which are very quick-acting devices and used in low power high-speed servo-systems. Chapter 2 describes the possible fields of application, design, construction, and utilization of magnetic particle couplings. The aspects of construction, design, and utilization of induction clutches (sli
Das, Ashok
2013-01-01
These lecture notes on electromagnetism have evolved from graduate and undergraduate EM theory courses given by the author at the University of Rochester, with the basics presented with clarity and his characteristic attention to detail. The thirteen chapters cover, in logical sequence, topics ranging from electrostatics, magnetostatics and Maxwell's equations to plasmas and radiation. Boundary value problems are treated extensively, as are wave guides, electromagnetic interactions and fields. This second edition comprises many of the topics expanded with more details on the derivation of vari
Beam conditions for radiation generated by an electromagnetic Gaussian Schell-model source.
Korotkova, Olga; Salem, Mohamed; Wolf, Emil
2004-06-01
It was shown recently that the basic properties of a fluctuating electromagnetic beam can be derived from knowledge of a 2 x 2 cross-spectral density matrix of the electric field in the source plane. However, not every such matrix represents a source that will generate a beamlike field. We derive conditions that the matrix must satisfy for the source to generate an electromagnetic Gaussian Schell-model beam.
Algebraic Methods in Plane Geometry
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 10. Algebraic Methods in Plane Geometry - The Use of Conic Sections. Shailesh A Shirali. General Article Volume 13 Issue 10 October 2008 pp 916-928. Fulltext. Click here to view fulltext PDF. Permanent link:
Distributed storage in the plane
Altman, Eitan; Avrachenkov, Konstatin; Goseling, Jasper
2013-01-01
We consider storage devices located in the plane according to a general point process and specialize the results for the homogeneous Poisson process. A large data file is stored at the storage devices, which have limited storage capabilities. Hence, they can only store parts of the data. Clients can
DEFF Research Database (Denmark)
Rathkjen, Arne
A state of plane stress is illustrated by means of two families of curves, each family representing constant values of a derivative of Airy's stress function. The two families of curves form a map giving in the first place an overall picture of regions of high and low stress, and in the second pl...
Complex Numbers and Plane Geometry
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 1. Complex Numbers and Plane Geometry. Anant R Shastri. General Article Volume 13 Issue 1 January 2008 pp 35-53. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/013/01/0035-0053. Keywords.
Electromagnetic interference: a radiant future!
Leferink, Frank Bernardus Johannes
2015-01-01
Although Electromagnetic Interference and Electromagnetic Compatibility are well established domains, the introduction of new technologies results in new challenges. Changes in both measurement techniques, and technological trends resulting in new types of interference are described. These are the
New perspectives on classical electromagnetism
Cote, Paul J.
2009-01-01
The fallacies associated with the gauge concept in electromagnetism are illustrated. A clearer and more valid formulation of the basics of classical electromagnetism is provided by recognizing existing physical constraints as well as the physical reality of the vector potential.
Electromagnetic fields in stratified media
Li, Kai
2009-01-01
Dealing with an important branch of electromagnetic theory with many useful applications in subsurface communication, radar, and geophysical prospecting and diagnostics, this book introduces electromagnetic theory and wave propagation in complex media.
Energy Technology Data Exchange (ETDEWEB)
Kortright, J.B.; Rice, M.; Hussain, Z. [Lawrence Berkeley National Lab., CA (United States)] [and others
1997-04-01
Growing interest in utilizing circular polarization prompted the design of bend-magnet beamline 9.3.2 at the Advanced Light Source, covering the 30-1500 eV spectral region, to include vertical aperturing capabilities for optimizing the collection of circular polarization above and below the orbit plane. After commissioning and early use of the beamline, a multilayer polarimeter was used to characterize the polarization state of the beam as a function of vertical aperture position. This report partially summarizes the polarimetry measurements and compares results with theoretical calculations intended to simulate experimental conditions.
Low frequency electromagnetic field sensor
International Nuclear Information System (INIS)
Zhu Min; Zhou Yan; He Yicheng; Zheng Zhenxing; Liu Sunkun
2000-01-01
The measurement technique of low frequency electromagnetic field is reported. According to this principle, the authors have designed a sensor, which is used to measure the natural electromagnetic field, SLEMP and electromagnetic signals generated by some explosions. The frequency band of this sensor is from 0.08 Hz to 2 MHz
Optical electromagnetic radiation detector
International Nuclear Information System (INIS)
Miceli, W. J.; Ludman, J. E.
1985-01-01
An optical electromagnetic radiation detector having a probe for receiving nearby electromagnetic radiation. The probe includes a loop antenna connected to a pair of transparent electrodes deposited on the end surfaces of an electro-optic Fabry-Perot interferometer. When the loop antenna picks up the presence of electromagnetic radiation, a voltage will be developed across the crystal of the electro-optic Fabry-Perot interferometer thereby changing the optical length of the interferometer. A beam of light from a remote location is transmitted through an optical fiber onto the Fabry-Perot interferometer. The change in optical length of the Fabry-Perot interferometer alters the intensity of the beam of light as it is reflected from the Fabry-Perot interferometer back through the optical fiber to the remote location. A beamsplitter directs this reflected beam of light onto an intensity detector in order to provide an output indicative of the variations in intensity. The variations in intensity are directly related to the strength of the electromagnetic radiation received by the loop antenna
Electromagnetic structure of nuclei
International Nuclear Information System (INIS)
Arnold, R.G.
1986-07-01
A brief review is given of selected topics in the electromagnetic structure of nucleons and nuclei, including nucleon form factors from both quantum chromodynamics and electron scattering data, measurements of the deuteron and triton form factors, quasi-elastic scattering, and the EMC effect. 47 refs., 13 figs
Introduction to electromagnetic compatibility
Paul, Clayton R.
A formal and extensive treatment of electromagnetic compatibility (EMC) is presented. Basic principles are reviewed in detail, including reasons for EMC in electronic design. Also discussed are: nonideal behavior of components, signal spectra, radiated emission and susceptibility, conducted emissions and susceptibility, crosstalk, shielding, electrostatic discharge, and system design for EMC.
Simple Superconducting "Permanent" Electromagnet
Israelson, Ulf E.; Strayer, Donald M.
1992-01-01
Proposed short tube of high-temperature-superconducting material like YBa2Cu3O7 acts as strong electromagnet that flows as long as magnetic field remains below critical value and temperature of cylinder maintained sufficiently below superconducting-transition temperature. Design exploits maximally anisotropy of high-temperature-superconducting material.
Equivalence principles and electromagnetism
Ni, W.-T.
1977-01-01
The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.
Nanofocusing of electromagnetic radiation
DEFF Research Database (Denmark)
Gramotnev, D. K.; Bozhevolnyi, Sergey I.
2014-01-01
Nanofocusing of electromagnetic radiation, that is, reducing the cross sections of propagating optical modes far beyond the diffraction limit in dielectric media, can be achieved in tapered metal-dielectric waveguides that support surface plasmon-polariton modes. Although the main principles...
Electromagnetism and Gravitation
Dalton, Kenneth
1995-01-01
The classical concept of "mass density" is not fundamental to the quantum theory of matter. Therefore, mass density cannot be the source of gravitation. Here, we treat electromagnetic energy, momentum, and stress as its source. The resulting theory predicts that the gravitational potential near any charged elementary particle is many orders of magnitude greater than the Newtonian value.
Electromagnetic distance measurement
1967-01-01
This book brings together the work of forty-eight geodesists from twenty-five countries. They discuss various new electromagnetic distance measurement (EDM) instruments - among them the Tellurometer, Geodimeter, and air- and satellite-borne systems - and investigate the complex sources of error.
Faraday: Father of Electromagnetism
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 3. Faraday: Father of Electromagnetism. S V Bhat. General Article Volume 7 Issue 3 March 2002 pp 46-50. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/007/03/0046-0050. Keywords. Faraday ...
Electromagnetic radiation detector
Benson, Jay L.; Hansen, Gordon J.
1976-01-01
An electromagnetic radiation detector including a collimating window, a cathode member having a photoelectric emissive material surface angularly disposed to said window whereby radiation is impinged thereon at acute angles, an anode, separated from the cathode member by an evacuated space, for collecting photoelectrons emitted from the emissive cathode surface, and a negatively biased, high transmissive grid disposed between the cathode member and anode.
Gauge theory of weak, electromagnetic and dual electromagnetic interactions
International Nuclear Information System (INIS)
Soln, J.
1980-01-01
An SU 2 x U 1 algebra, in addition to the ordinary electric charge, also establishes the existence of the dual electric charge. This is taken as an indication of the existence of dual electromagnetic interactions in nature. Here, the unification of weak, electromagnetic and dual electromagnetic interactions is performed. The Yang-Mills-type group which contains the electromagnetic, dual electromagnetic and weak currents is SUsub(L,2) x U 1 x U' 1 . The masses of vector mesons are generated through the Higgs-Kibble mechanism. A simple consistency requirement suggests that dual electromagnetism and ordinary electromagnetism have the same strengths, leading the theory to a rather good agreement with experiments. (author)
Computational Electronics and Electromagnetics
Energy Technology Data Exchange (ETDEWEB)
DeFord, J.F.
1993-03-01
The Computational Electronics and Electromagnetics thrust area is a focal point for computer modeling activities in electronics and electromagnetics in the Electronics Engineering Department of Lawrence Livermore National Laboratory (LLNL). Traditionally, they have focused their efforts in technical areas of importance to existing and developing LLNL programs, and this continues to form the basis for much of their research. A relatively new and increasingly important emphasis for the thrust area is the formation of partnerships with industry and the application of their simulation technology and expertise to the solution of problems faced by industry. The activities of the thrust area fall into three broad categories: (1) the development of theoretical and computational models of electronic and electromagnetic phenomena, (2) the development of useful and robust software tools based on these models, and (3) the application of these tools to programmatic and industrial problems. In FY-92, they worked on projects in all of the areas outlined above. The object of their work on numerical electromagnetic algorithms continues to be the improvement of time-domain algorithms for electromagnetic simulation on unstructured conforming grids. The thrust area is also investigating various technologies for conforming-grid mesh generation to simplify the application of their advanced field solvers to design problems involving complicated geometries. They are developing a major code suite based on the three-dimensional (3-D), conforming-grid, time-domain code DSI3D. They continue to maintain and distribute the 3-D, finite-difference time-domain (FDTD) code TSAR, which is installed at several dozen university, government, and industry sites.
International Nuclear Information System (INIS)
Gao Chunxia; Wang Lianghou
2005-01-01
The characteristics of different types of PML were analyzed and the convolutional PML was chosen to truncate the open boundaries in numerical simulation of nuclear electromagnetic pulse from air explosions. On the basis of the split-field PML and the plane-wave solution of electromagnetic field in free space, the unsplit-field PML was constructed. By applying the convolutional theorem of Fourier transform, the discrete iterative equations of electromagnetic field components were presented in the CPML media under the two-dimension prolate-spheroidal coordinate system. The numerical results indicate that the method of CPML can largely decrease calculation errors of boundary fields. (authors)
Directory of Open Access Journals (Sweden)
Marit Anne Hauan
2012-05-01
Full Text Available In this paper my aim is to read and understand the journal of Gerrit de Veer from the last journey of William Barents to the Arctic Regions in 1596 and the journal of captain Junge on his hunting trip from Tromsø to Svalbard in 1834.It is nearly 240 years between this to voyages. The first journal is known as the earliest report from the arctic era. Gerrit de Veer adds instructive copper engravings to his text and give us insight in the crews meeting with this new land. Captain Junges journal is found together with his dead crew in a house in a fjord nearby Ny-Ålesund and has no drawings, but word. Both of these journals may be read as sources of the knowledge and understanding of the polar region. They might also unveil the ideas of how to deal with and survive under the challenges that is given. In addition one can ask if the sources can tell us more about how men describe their challenges. Can the way they expressed themselves in the journals give us an understanding of masculinity? And not least help us to create good questions of the change in the ideas of masculinities which is said to follow the change in understanding of the wilderness.
Electromagnetic behaviour of the earth and planets
International Nuclear Information System (INIS)
McCarthy, A.J.
2002-01-01
Forecast problems of global warming, rising sea-levels, UV enhancement, and solar disruptions of power grids and satellite communications, have been widely discussed. Added to these calamities is the steady decay of the Earth's magnetic radiation shield against high energy particles. A system of solar-induced aperiodic electromagnetic resonances, referred to here as the Debye resonances, is resurrected as the preferred basis for describing the electromagnetic behaviour of the Earth and planets. Debye's two basic solutions to the spherical vector wave equation provide foundations for electromagnetic modes of the terrestrial and gaseous planets respectively in contrast with the separate electric and magnetic approaches usually taken. For those engaged in radiation protection issues, this paper provides the first published account of how the Sun apparently triggers an Earth magnetic shield against its own harmful radiation. Disturbances from the Sun - which are random in terms of polarity, polarisation, amplitude, and occurrence - are considered here to trigger the Debye modes and generate observed planetary electric and magnetic fields. Snapping or reconnection of solar or interplanetary field lines, acting together with the newly conceived magnetospheric transmission lines of recent literature, is suspected as the excitation mechanism. Virtual replacement of free space by plasma, places the electromagnetic behaviour of the Earth and planets under greatly enhanced control from the Sun. From a radiation protection viewpoint, modal theory based on solar-terrestrial coupling provides a new insight into the origin of the Earth's magnetic radiation shield, greater understanding of which is essential to development of global cosmic radiation protection strategies. Should man-made influences unduly increase conductivities of the Earth's magnetosphere, planet Earth could be left with no magnetic radiation shield whatsoever. Copyright (2002) Australasian Radiation Protection
Hydrodynamics of planing monohull watercraft
Vorus, William S
2017-01-01
This book addresses the principles involved in the design and engineering of planing monohull power boats, with an emphasis on the theoretical fundamentals that readers need in order to be fully functional in marine design and engineering. Author William Vorus focuses on three topics: boat resistance, seaway response, and propulsion and explains the physical principles, mathematical details, and theoretical details that support physical understanding. In particular, he explains the approximations and simplifications in mathematics that lead to success in the applications of planing craft design engineering, and begins with the simplest configuration that embodies the basic physics. He leads readers, step-by-step, through the physical complications that occur, leading to a useful working knowledge of marine design and engineering. Included in the book are a wealth of examples that exemplify some of the most important naval architecture and marine engineering problems that challenge many of today’s engineers.
Plane waves with weak singularities
International Nuclear Information System (INIS)
David, Justin R.
2003-03-01
We study a class of time dependent solutions of the vacuum Einstein equations which are plane waves with weak null singularities. This singularity is weak in the sense that though the tidal forces diverge at the singularity, the rate of divergence is such that the distortion suffered by a freely falling observer remains finite. Among such weak singular plane waves there is a sub-class which does not exhibit large back reaction in the presence of test scalar probes. String propagation in these backgrounds is smooth and there is a natural way to continue the metric beyond the singularity. This continued metric admits string propagation without the string becoming infinitely excited. We construct a one parameter family of smooth metrics which are at a finite distance in the space of metrics from the extended metric and a well defined operator in the string sigma model which resolves the singularity. (author)
Wave propagation in electromagnetic media
International Nuclear Information System (INIS)
Davis, J.L.
1990-01-01
This book is concerned with wave propagation in reacting media, specifically in electromagnetic materials. An account is presented of the mathematical methods of wave phenomena in electromagnetic materials. The author presents the theory of time-varying electromagnetic fields, which involves a discussion of Faraday's laws, Maxwell's equations and their application to electromagnetic wave propagation under a variety of conditions. The author gives a discussion of magnetohydrodynamics and plasma physics. Chapters are included on quantum mechanics and the theory of relativity. The mathematical foundation of electromagnetic waves vis a vis partial differential equations is discussed
Effect of radio frequency waves of electromagnetic field on the tubulin.
Taghi, Mousavi; Gholamhosein, Riazi; Saeed, Rezayi-Zarchi
2013-09-01
Microtubules (MTs) are macromolecular structures consisting of tubulin heterodimers and present in almost every eukaryotic cell. MTs fulfill all conditions for generation of electromagnetic field and are electrically polar due to the electrical polarity of a tubulin heterodimer. The calculated static electric dipole moment of about 1000 Debye makes them capable of being aligned parallel to the applied electromagnetic field direction. In the present study, the tubulin heterodimers were extracted and purified from the rat brains. MTs were obtained by polymerization in vitro. Samples of microtubules were adsorbed in the absence and in the presence of electromagnetic fields with radio frequency of 900 Hz. Our results demonstrate the effect of electromagnetic field with 900 Hz frequency to change the structure of MTs. In this paper, a related patent was used that will help to better understand the studied subject.
Algebraic Methods in Plane Geometry
Indian Academy of Sciences (India)
Srimath
the role ofm appings and transform ation groups in plane geom etry. 1. P arabola in a Triangle. W e ¯rst recall tw o results from the geom etry of the parabola. Let P denote a parabola w ith focus F and d irectrix `. For any point P 2 P , let tP denote the tangent to P at P . (i) T he im age ofF under re°ection in any ofthe tangents.
Spectrum of classes of point emitters of electromagnetic wave fields.
Castañeda, Román
2016-09-01
The spectrum of classes of point emitters has been introduced as a numerical tool suitable for the design, analysis, and synthesis of non-paraxial optical fields in arbitrary states of spatial coherence. In this paper, the polarization state of planar electromagnetic wave fields is included in the spectrum of classes, thus increasing its modeling capabilities. In this context, optical processing is realized as a filtering on the spectrum of classes of point emitters, performed by the complex degree of spatial coherence and the two-point correlation of polarization, which could be implemented dynamically by using programmable optical devices.
Magnetization reversal in ferromagnetic film through solitons by electromagnetic field
International Nuclear Information System (INIS)
Veerakumar, V.; Daniel, M.
2001-07-01
We study the reversal of magnetization in an isotopic ferromagnetic film free from charges by exposing it to a circularly polarized electromagnetic (EM) field. The magnetization excitations are obtained in the form of line and lump solitons of the completely integrable modified KP-II equation which is derived using a reductive perturbation method from the set of coupled Landau-Lifschitz and Maxwell equations. It is observed that when the polarization of the EM-field is reversed followed by a rotation, for every (π)/2-degrees, the magnetization is reversed. (author)
ECLAIRs detection plane: current state of development
Lacombe, K.; Pons, R.; Amoros, C.; Atteia, J.-L.; Barret, D.; Billot, M.; Bordon, S.; Cordier, B.; Gevin, O.; Godet, O.; Gonzalez, F.; Houret, B.; Mercier, K.; Mandrou, P.; Marty, W.; Nasser, G.; Rambaud, D.; Ramon, P.; Rouaix, G.; Waegebaert, V.
2014-07-01
ECLAIRs, a 2-D coded-mask imaging camera on-board the Sino-French SVOM space mission, will detect and locate Gamma-ray bursts (GRBs) in near real time in the 4-150 keV energy band. The design of ECLAIRs has been mainly driven by the objective of achieving a low-energy threshold of 4 keV, unprecedented for this type of instrument. The detection plane is an assembly of 6400 Schottky CdTe semiconductor detectors of size 4x4x1 mm3 organized on elementary hybrid matrices of 4x8 detectors. The detectors will be polarized from -300V to -500V and operated at -20°C to reduce both the leakage current and the polarization effect induced by the Schottky contact. The remarkable low-energy threshold homogeneity required for the detection plane has been achieved thanks to: i) an extensive characterization and selection of the detectors, ii) the development of a specific low-noise 32-channel ASIC, iii) the realization of an innovative hybrid module composed of a thick film ceramic (holding 32 CdTe detectors with their high voltage grid), associated to an HTCC ceramic (housing the ASIC chip within an hermetic enclosure). In this paper, we start describing a complete hybrid matrix, and then the manufacturing of a first set of 50 matrices (representing 1600 detectors, i.e. a quarter of ECLAIRs detector's array). We show how this manufacturing allowed to validate the different technologies used for this hybridization, as well as the industrialization processes. During this phase, we systematically measured the leakage current on Detector Ceramics after an outgassing, and the Equivalent Noise Charge (ENC) for each of the 32 channels on ASIC Ceramics, in order to optimize the coupling of the two ceramics. Finally, we performed on each hybrid module, spectral measurements at -20°C in our vacuum chamber, using several calibrated radioactive sources (241Am and 55Fe), to check the performance homogeneity of the 50 modules. The results demonstrated that the 32-detector hybrid matrices
Near-perfect conversion of a propagating plane wave into a surface wave using metasurfaces
Tcvetkova, S. N.; Kwon, D.-H.; Díaz-Rubio, A.; Tretyakov, S. A.
2018-03-01
In this paper theoretical and numerical studies of perfect/nearly perfect conversion of a plane wave into a surface wave are presented. The problem of determining the electromagnetic properties of an inhomogeneous lossless boundary which would fully transform an incident plane wave into a surface wave propagating along the boundary is considered. An approximate field solution which produces a slowly growing surface wave and satisfies the energy conservation law is discussed and numerically demonstrated. The results of the study are of great importance for the future development of such devices as perfect leaky-wave antennas and can potentially lead to many novel applications.
Light-induced spin polarizations in quantum rings
Joibari, F.K.; Blanter, Y.M.; Bauer, G.E.W.
2014-01-01
Nonresonant circularly polarized electromagnetic radiation can exert torques on magnetizations by the inverse Faraday effect (IFE). Here, we discuss the enhancement of IFE by spin-orbit interactions. We illustrate the principle by studying a simple generic model system, i.e., the
The polarized platypus polarized neutron reflectometry made possible
International Nuclear Information System (INIS)
Saerbeck, Thomas
2009-01-01
Full text: The magnetic moment of the neutron, together with it's highly penetrating non destructive manner, make polarized neutron reflectometry an excellent tool to study magnetic phenomena across surfaces and interfaces of thin films. Unlike other magnetometry techniques which ordinarily yield only average magnetization values or, in case of probes with higher spatial resolution (e.g. electron microscopy or scanning tunnelling microscopy), show a high surface sensitivity, PNR together with magnetic x-ray scattering provides the ability to spatially resolve vector magnetization well beneath the surface [1] The ability to obtain vector magnetization profiles across interfaces and surfaces of thin films and multilayers offers the intriguing possibility to study systematically magnetic configurations and magnetic exchange interactions through intervening layers. In this paper we present the performance of the new polarization system installed on the time of flight neutron reflectometer PLATYPUS at ANSTO's Bragg Institute. The spin state of the neutrons is polarized and analysed by spatial separation of different neutron spin states using polarizing Fe/Si supermirrors before, and after the sample stage. The supermirrors have a large wavelength acceptance bandwidth of 3 A to 12 A. To control the desired spin direction of the incoming and reflected beam from the sample, two sets of RF spin flippers are installed. In the free space between the spin flippers and the sample stage the neutron spin direction is maintained by two sets of magnetic guide field coils. The new sample environment for studies of magnetic samples includes a 1 T electromagnet and a closed cycle refrigerator which gives access to a temperature range from 4K to 3 50 K .
Absorption of Electro-magnetic Waves in a Magnetized Medium
Ganguly, Avijit K.; Konar, Sushan
2000-01-01
In continuation to our earlier work, in which the structure of the vacuum polarisation tensor in a medium was analysed in presence of a background electro-magnetic field, we discuss the absorptive part of the vacuum polarization tensor. Using the real time formalism of finite temperature field theory we calculate the absorptive part of 1-loop vacuum polarisation tensor in the weak field limit ($eB < m^2$). Estimates of the absorption probability are also made for different physical conditions...
Manipulating electromagnetic waves with metamaterials: Concept and microwave realizations
International Nuclear Information System (INIS)
He Qiong; Xiao Shi-Yi; Li Xin; Song Zheng-Yong; Sun Wu-Jiong; Zhou Lei; Sun Shu-Lin
2014-01-01
Our recent efforts in manipulating electromagnetic (EM) waves using metamaterials (MTMs) are reviewed with emphasis on 1) manipulating wave polarization and transporting properties using homogeneous MTMs, 2) manipulating surface-wave properties using plasmonic MTMs, and 3) bridging propagating and surface waves using inhomogeneous meta-surfaces. For all these topics, we first illustrate the physical concepts and then present several typical practical realizations and applications in the microwave regime. (topical review - plasmonics and metamaterials)
Electromagnetic and transient shielding effectiveness for near-field sources
Directory of Open Access Journals (Sweden)
C. Möller
2007-06-01
Full Text Available The contribution deals with an investigation of the recently proposed definitions for the electromagnetic and transient shielding effectiveness (SE in the case of an electric-dipole near-field source. To this end, new factors are introduced which depend on the distance between the dipole source and the measurement point inside the shield and which are valid for perpendicularly (with respect to the distance vector polarized dipoles. Numerical results support and confirm the theoretical derivations.
Epatko, [No Value; Malyutin, AA; Serov, RV; Solov'ev, DA
An expression is obtained for the aberration operator of a plane-parallel plate and it is shown that its use in the far-field zone makes it possible to take full account of electromagnetic field perturbations. Examples are given of calculations in accordance with the proposed algorithm when the
Visualization and manipulation of meta-stable polarization variants in multiferroic materials
Directory of Open Access Journals (Sweden)
Moonkyu Park
2013-04-01
Full Text Available Here we demonstrate the role of meta-stable polarization variants in out-of-plane polarization switching behavior in epitaxially grown BiFeO3 thin films using angle-resolved piezoresponse force microscopy (AR-PFM. The out-of-plane polarization switching mainly occurred at the boundary between meta-stable and stable polarization domains, and was accompanied by a significant change in in-plane domain configuration from complicated structure with 12 polarization variants to simple stripe structure with 4 polarization variants. These results imply that the biased tip rearranges the delicately balanced domain configuration, which is determined by the competition between electrostatic and strain energies, into simple interweaving one that is more thermodynamically stable.
On the energy-momentum density of gravitational plane waves
International Nuclear Information System (INIS)
Dereli, T; Tucker, R W
2004-01-01
By embedding Einstein's original formulation of general relativity into a broader context, we show that a dynamic covariant description of gravitational stress-energy emerges naturally from a variational principle. A tensor T G is constructed from a contraction of the Bel tensor with a symmetric covariant second degree tensor field Φ and has a form analogous to the stress-energy tensor of the Maxwell field in an arbitrary spacetime. For plane-fronted gravitational waves helicity-2 polarized (graviton) states can be identified carrying non-zero energy and momentum
Numerical simulation of the drop spreading on a horizontal plane
Zyuzina, N. A.; Ostapenko, V. V.
2017-10-01
A shallow water model of film flow is used to describe the process of a drop spreading on a horizontal plane, taking into account the liquid viscosity, heat-mass transfer and surface tension forces. To simulate this flow numerically in polar coordinates an unconditionally stable implicit difference scheme has been developed, which (in the case of evaporation) can calculate the drop spreading over a dry surface without special allocation of the drop boundary. A region of dimensionless parameters is singled out under which the evaporating droplet, as a result of surface tension forces, transforms into a circular ring before complete evaporation.
Vacuum polarization and Hawking radiation
Rahmati, Shohreh
Quantum gravity is one of the interesting fields in contemporary physics which is still in progress. The purpose of quantum gravity is to present a quantum description for spacetime at 10-33cm or find the 'quanta' of gravitational interaction.. At present, the most viable theory to describe gravitational interaction is general relativity which is a classical theory. Semi-classical quantum gravity or quantum field theory in curved spacetime is an approximation to a full quantum theory of gravity. This approximation considers gravity as a classical field and matter fields are quantized. One interesting phenomena in semi-classical quantum gravity is Hawking radiation. Hawking radiation was derived by Stephen Hawking as a thermal emission of particles from the black hole horizon. In this thesis we obtain the spectrum of Hawking radiation using a new method. Vacuum is defined as the possible lowest energy state which is filled with pairs of virtual particle-antiparticle. Vacuum polarization is a consequence of pair creation in the presence of an external field such as an electromagnetic or gravitational field. Vacuum polarization in the vicinity of a black hole horizon can be interpreted as the cause of the emission from black holes known as Hawking radiation. In this thesis we try to obtain the Hawking spectrum using this approach. We re-examine vacuum polarization of a scalar field in a quasi-local volume that includes the horizon. We study the interaction of a scalar field with the background gravitational field of the black hole in the desired quasi-local region. The quasi-local volume is a hollow cylinder enclosed by two membranes, one inside the horizon and one outside the horizon. The net rate of particle emission can be obtained as the difference of the vacuum polarization from the outer boundary and inner boundary of the cylinder. Thus we found a new method to derive Hawking emission which is unitary and well defined in quantum field theory.
Measurement of Λ polarization from Z decays
Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Lucotte, A.; Minard, M.-N.; Odier, P.; Pietrzyk, B.; Chmeissani, M.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Juste, A.; Martinez, M.; Orteu, S.; Pacheco, A.; Padilla, C.; Palla, F.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Farilla, A.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A. O.; Bonvicini, G.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Harvey, J.; Jacobsen, R.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Martin, E. B.; Mato, P.; Minten, A.; Miquel, R.; Mir, Ll. M.; Moneta, L.; Oest, T.; Palazzi, P.; Pater, J. R.; Pusztaszeri, J.-F.; Ranjard, F.; Rensing, P.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajlatouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rossignol, J.-M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Rougé, A.; Rumpf, M.; Tanaka, R.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R. M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Rensch, B.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Dornan, P. J.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Stacey, A. M.; Williams, M. D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Whelan, E. P.; Williams, M. I.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.-G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Etienne, F.; Konstantinidis, N.; Nicod, D.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Trabelsi, K.; Abt, I.; Assmann, R.; Bauer, C.; Blum, W.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Jakobs, K.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H.-G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; Denis, R. St.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Nikolic, I.; Park, H. J.; Park, I. C.; Schune, M.-H.; Simion, S.; Veillet, J.-J.; Videau, I.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Blair, G. A.; Bryant, L. M.; Cerutti, F.; Chambers, J. T.; Gao, Y.; Green, M. G.; Johnson, D. L.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Beddall, A.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W. M.; Rankin, C.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Büscher, V.; Cowan, G.; Grupen, C.; Lutters, G.; Minguet-Rodriguez, J.; Rivera, F.; Saraiva, P.; Smolik, L.; Stephan, F.; Aleppo, M.; Apollonio, M.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Ragusa, F.; Rothberg, J.; Wasserbaech, S.; Armstrong, S. R.; Bellantoni, L.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T. C.; Harton, J. L.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I. J.; Sharma, V.; Turk, J. D.; Walsh, A. M.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.; Aleph Collaboration
1996-02-01
The polarization of Λ baryons from Z decays is studied with the ALEPH apparatus. Evidence of longitudinal polarization of s quarks from Z decay is observed for the first time. The measured longitudinal Λ polarization is PLΛ = -0.32 ± 0.07 for z = {p}/{p beam} > 0.3 . This agrees with the prediction of -0.39 ± 0.08 from the standard model and the constituent quark model, where the error is due to uncertainties in the mechanism for Λ production. The observed Λ polarization is diluted with respect to the primary s quark polarization by Λ baryons without a primary s quark. Measurements of the Λ forward-backward asymmetry and of the correlation between back-to-back Λ overlineΛ pairs are used to check this dilution. In addition the transverse Λ polarization is measured. An indication of transverse polarization, more than two standard deviations away from zero, is found along the normal to the plane defined by the thrust axis and the Λ direction.
Measurement of $\\Lambda$ polarization from Z decays
Buskulic, Damir; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Chmeissani, M; Crespo, J M; Delfino, M C; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Alemany, R; Bazarko, A O; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Mir, L M; Moneta, L; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wagner, A; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Wäänänen, A; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Abbaneo, D; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Moutoussi, A; Nash, J; Sedgbeer, J K; Stacey, A M; Williams, M D; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Konstantinidis, N P; Nicod, D; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Chambers, J T; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Köksal, A; Letho, M; Newton, W M; Rankin, C; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Büscher, V; Cowan, G D; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Aleppo, M; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Greening, T C; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G
1996-01-01
The polarization of \\Lambda baryons from Z decays is studied with the {\\sc Aleph} apparatus. Evidence of longitudinal polarization of s quarks from Z decay is observed for the first time. The measured longitudinal \\Lambda polarization is P^{\\Lambda}_{L} = -0.32 \\pm 0.07 for z = p/p_{\\mathrm{beam}} > 0.3. This agrees with the prediction of -0.39 \\pm 0.08 from the standard model and the constituent quark model, where the error is due to uncertainties in the mechanism for \\Lambda production. The observed \\Lambda polarization is diluted with respect to the primary s quark polarization by \\Lambda baryons without a primary s quark. Measurements of the \\Lambda forward-backward asymmetry and of the correlation between back-to-back \\Lambda \\bar{\\Lambda} pairs are used to check this dilution. In addition the transverse \\Lambda polarization is measured. An indication of transverse polarization, more than two standard deviations away from zero, is found along the normal to the plane defined by the thrust axis and the \\La...
Electromagnetic induction spectroscopy
Won, I. J.; Keiswetter, Dean A.
1998-09-01
An object, made partly or wholly of metals, has a distinct combination of electrical conductivity, magnetic permeability, and geometrical shape and size. When the object is exposed to a low-frequency electromagnetic field, it produces a secondary magnetic field. By measuring the secondary field in a broadband spectrum, we obtain a distinct spectral signature that may uniquely identify the object. Based on the response spectrum, we attempt to 'fingerprint' the object. This is the basic concept of Electromagnetic Induction Spectroscopy (EMIS). EMIS technology may be particularly useful for detecting buried landmines and unexploded ordnance. By fully characterizing and identifying an object without excavation. We should be able to reduce significantly the number of false targets. EMIS should be fully applicable to many other problems where target identification and recognition (without intrusive search) are important. For instance, an advanced EMIS device at an airport security gate may be able to recognize a particular weapon by its maker and type.
The KLOE electromagnetic calorimeter
International Nuclear Information System (INIS)
Adinolfi, M.; Ambrosino, F.; Antonelli, A.; Antonelli, M.; Anulli, F.; Barbiellini, G.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocci, V.; Bossi, F.; Branchini, P.; Cabibbo, G.; Caloi, R.; Campana, P.; Casarsa, M.; Cataldi, G.; Ceradini, F.; Cervelli, F.; Ciambrone, P.; De Lucia, E.; De Simone, P.; De Zorzi, G.; Dell'Agnello, S.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Falco, S.; Doria, A.; Erriquez, O.; Farilla, A.; Ferrari, A.; Ferrer, M.L.; Finocchiaro, G.; Forti, C.; Franceschi, A.; Franzini, P.; Gao, M.L.; Gatti, C.; Gauzzi, P.; Giannasi, A.; Giovannella, S.; Graziani, E.; Han, H.G.; Han, S.W.; Huang, X.; Incagli, M.; Ingrosso, L.; Keeble, L.; Kim, W.; Kuo, C.; Lanfranchi, G.; Lee-Franzini, J.; Lomtadze, T.; Mao, C.S.; Martemianov, M.; Mei, W.; Messi, R.; Miscetti, S.; Moccia, S.; Moulson, M.; Mueller, S.; Murtas, F.; Pacciani, L.; Palomba, M.; Palutan, M.; Pasqualucci, E.; Passalacqua, L.; Passeri, A.; Picca, D.; Pirozzi, G.; Pontecorvo, L.; Primavera, M.; Santangelo, P.; Santovetti, E.; Saracino, G.; Schamberger, R.D.; Sciascia, B.; Scuri, F.; Sfiligoi, I.; Silano, P.; Spadaro, T.; Spiriti, E.; Tortora, L.; Valente, P.; Valeriani, B.; Venanzoni, G.; Ventura, A.; Woelfle, S.; Wu, Y.; Xie, Y.G.; Zema, P.F.; Zhang, C.D.; Zhang, J.Q.; Zhao, P.P.
2002-01-01
The KLOE detector was designed primarily for the study of CP violation in neutral kaon decays at DAPHINE, the Frascati phi-factory. The detector consists of a tracker and an electromagnetic calorimeter. A lead-scintillating-fiber sampling calorimeter satisfies best the requirements of the experiment, providing adequate energy resolution and superior timing accuracy. We describe in the following the construction of the calorimeter, its calibration and how the calorimeter information is used to obtain energy, point of entry and time of the arrival of photons, electrons and charged particles. With e + e - collision data at DAPHINE for an integrated luminosity of some 2 pb -1 we find for electromagnetic showers, an energy resolution of 5.7%/√E(GeV) and a time resolution of 54/√E(GeV) ps. We also present a measurement of efficiency for low energy photons
The KLOE electromagnetic calorimeter
Adinolfi, M; Antonelli, A; Antonelli, M; Anulli, F; Barbiellini, G; Bencivenni, G; Bertolucci, Sergio; Bini, C; Bloise, C; Bocci, V; Bossi, F; Branchini, P; Cabibbo, G; Caloi, R; Campana, P; Casarsa, M; Cataldi, G; Ceradini, F; Cervelli, F; Ciambrone, P; De Lucia, E; De Simone, P; De Zorzi, G; Dell'Agnello, S; Denig, A; Di Domenico, A; Di Donato, C; Di Falco, S; Doria, A; Erriquez, O; Farilla, A; Ferrari, A; Ferrer, M L; Finocchiaro, G; Forti, C; Franceschi, A; Franzini, P; Gao, M L; Gatti, C; Gauzzi, P; Giannasi, A; Giovannella, S; Graziani, E; Han, H G; Han, S W; Huang, X; Incagli, M; Ingrosso, L; Keeble, L; Kim, W; Kuo, C; Lanfranchi, G; Lee-Franzini, J; Lomtadze, T A; Mao Chen Sheng; Martemyanov, M; Mei, W; Messi, R; Miscetti, S; Moccia, S; Moulson, M; Murtas, F; Müller, S; Pacciani, L; Palomba, M; Palutan, M; Pasqualucci, E; Passalacqua, L; Passeri, A; Picca, D; Pirozzi, G; Pontecorvo, L; Primavera, M; Santangelo, P; Santovetti, E; Saracino, G; Schamberger, R D; Sciascia, B; Scuri, F; Sfiligoi, I; Silano, P; Spadaro, T; Spiriti, E; Tortora, L; Valente, P; Valeriani, B; Venanzoni, G; Ventura, A; Wu, Y; Wölfle, S; Xie, Y G; Zema, P F; Zhang, C D; Zhang, J Q; Zhao, P P
2002-01-01
The KLOE detector was designed primarily for the study of CP violation in neutral kaon decays at DAPHINE, the Frascati phi-factory. The detector consists of a tracker and an electromagnetic calorimeter. A lead-scintillating-fiber sampling calorimeter satisfies best the requirements of the experiment, providing adequate energy resolution and superior timing accuracy. We describe in the following the construction of the calorimeter, its calibration and how the calorimeter information is used to obtain energy, point of entry and time of the arrival of photons, electrons and charged particles. With e sup + e sup - collision data at DAPHINE for an integrated luminosity of some 2 pb sup - sup 1 we find for electromagnetic showers, an energy resolution of 5.7%/sq root E(GeV) and a time resolution of 54/sq root E(GeV) ps. We also present a measurement of efficiency for low energy photons.
Computational electronics and electromagnetics
International Nuclear Information System (INIS)
Shang, C C
1998-01-01
The Computational Electronics and Electromagnetics thrust area serves as the focal point for Engineering R and D activities for developing computer-based design and analysis tools. Representative applications include design of particle accelerator cells and beamline components; design of transmission line components; engineering analysis and design of high-power (optical and microwave) components; photonics and optoelectronics circuit design; electromagnetic susceptibility analysis; and antenna synthesis. The FY-97 effort focuses on development and validation of (1) accelerator design codes; (2) 3-D massively parallel, time-dependent EM codes; (3) material models; (4) coupling and application of engineering tools for analysis and design of high-power components; and (5) development of beam control algorithms coupled to beam transport physics codes. These efforts are in association with technology development in the power conversion, nondestructive evaluation, and microtechnology areas. The efforts complement technology development in Lawrence Livermore National programs
Electromagnetic fields and waves
Iskander, Magdy F
2013-01-01
The latest edition of Electromagnetic Fields and Waves retains an authoritative, balanced approach, in-depth coverage, extensive analysis, and use of computational techniques to provide a complete understanding of electromagnetic—important to all electrical engineering students. An essential feature of this innovative text is the early introduction of Maxwell's equations, together with the quantifying experimental observations made by the pioneers who discovered electromagnetics. This approach directly links the mathematical relations in Maxwell's equations to real experiments and facilitates a fundamental understanding of wave propagation and use in modern practical applications, especially in today's wireless world. New and expanded topics include the conceptual relationship between Coulomb's law and Gauss's law for calculating electric fields, the relationship between Biot-Savart's and Ampere's laws and their use in calculating magnetic fields from current sources, the development of Faraday's law from e...
Classical Electromagnetic Theory
VanderLinde, Jack
2004-01-01
This book is a self contained course in electromagnetic theory suitable for senior physics and electrical engineering students as well as graduate students whose past has not prepared them well for books such as Jackson or Landau and Lifschitz. The text is liberally sprinkled with worked examples illustrating the application of the theory to various physical problems. In this new edition I have endeavored to improve the accuracy and readability, added and further clarified examples, added sections on Schwarz-Christoffel mappings, and to make the book more self sufficient added an appendix on orthogonal function expansions and added the derivation of Bessel functions and Legendre polynomials as well as derivation of their generating functions. The number of student exercises has been increased by 45 over the previous edition. This book stresses the unity of electromagnetic theory with electric and magnetic fields developed in parallel. SI units are used throughout and considerable use is made of tensor notatio...
Introduction to electromagnetic theory
Owen, George E
2003-01-01
A direct, stimulating approach to electromagnetic theory, this text employs matrices and matrix methods for the simple development of broad theorems. The author uses vector representation throughout the book, with numerous applications of Poisson's equation and the Laplace equation (the latter occurring in both electronics and magnetic media). Contents include the electrostatics of point charges, distributions of charge, conductors and dielectrics, currents and circuits, and the Lorentz force and the magnetic field. Additional topics comprise the magnetic field of steady currents, induced ele
Fractal Electromagnetic Showers
Anchordoqui, L. A.; Kirasirova, M.; McCauley, T. P.; Paul, T.; Reucroft, S.; Swain, J. D.
2000-01-01
We study the self-similar structure of electromagnetic showers and introduce the notion of the fractal dimension of a shower. Studies underway of showers in various materials and at various energies are presented, and the range over which the fractal scaling behaviour is observed is discussed. Applications to fast shower simulations and identification, particularly in the context of extensive air showers, are also discussed.
The KLOE electromagnetic calorimeter
International Nuclear Information System (INIS)
Adinolfi, M.; Ambrosino, F.; Antonelli, A.; Antonelli, M.; Anulli, F.; Barbiellini, G.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocci, V.; Bossi, F.; Branchini, P.; Cabibbo, G.; Caloi, R.; Campana, P.; Casarsa, M.; Cataldi, G.; Ceradini, F.; Cervelli, F.; Ciambrone, P.; De Lucia, E.; De Simone, P.; De Zorzi, G.; Dell'Agnello, S.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Falco, S.; Doria, A.; Erriquez, O.; Farilla, A.; Ferrari, A.; Ferrer, M.L.; Finocchiaro, G.; Forti, C.; Franceschi, A.; Franzini, P.; Gao, M.L.; Gatti, C.; Gauzzi, P.; Giannasi, A.; Giovannella, S.; Graziani, E.; Han, H.G.; Han, S.W.; Huang, X.; Incagli, M.; Ingrosso, L.; Keeble, L.; Kim, W.; Kuo, C.; Lanfranchi, G.; Lee-Franzini, J.; Lomtadze, T.; Mao, C.S.; Martemianov, M.; Mei, W.; Messi, R.; Miscetti, S.; Moccia, S.; Moulson, M.; Mueller, S.; Murtas, F.; Pacciani, L.; Palomba, M.; Palutan, M.; Pasqualucci, E.; Passalacqua, L.; Passeri, A.; Picca, D.; Pirozzi, G.; Pontecorvo, L.; Primavera, M.; Santangelo, P.; Santovetti, E.; Saracino, G.; Schamberger, R.D.; Sciascia, B.; Scuri, F.; Sfiligoi, I.; Silano, P.; Spadaro, T.; Spiriti, E.; Tortora, L.; Valente, P.; Valeriani, B.; Venanzoni, G.; Ventura, A.; Woelfle, S.; Wu, Y.; Xie, Y.G.; Zema, P.F.; Zhang, C.D.; Zhang, J.Q.; Zhao, P.P.
2002-01-01
The KLOE calorimeter is a fine lead-scintillating fiber sampling calorimeter. We describe in the following the calibration procedures and the calorimeter performances obtained after 3 years of data taking. We get an energy resolution for electromagnetic showers of 5.4%/√E(GeV) and a time resolution of 56 ps/√E(GeV). We also present a measurement of efficiency for low-energy photons
Electromagnetic Hammer for Metalworking
Anderson, S. A.; Brunet, F.; Dowd, A.; Durham, R.; Ezell, J.; Gorr, G.; Hartley, D.; Jackson, F.; Marchand, J.; Macfarlane, W.;
1986-01-01
High eddy currents apply pressure for cold-forming. Coil housing constructed for mechanical strength to hold coil against magnetic force, to maintain electrical contact with coil ends, and to maintain insulation between coil turns. Drilled holes placed to facilitate release of bubbles during potting. In contrast with mechanical hammers, electromagnetic hammer requires no dynamic material contact with workpiece; consequently, produces almost no change in metal grain structure.
Electromagnetic polarizabilities of hadrons
International Nuclear Information System (INIS)
Friar, J.L.
1988-01-01
Electromagnetic polarizabilities of hadrons are reviewed, after a discussion of classical analogues. Differences between relativistic and non-relativistic approaches can lead to conflicts with conventional nuclear physics sum rules and calculational techniques. The nucleon polarizabilities are discussed in the context of the non-relativistic valence quark model, which provides a good qualitative description. The recently measured pion polarizabilities are discussed in the context of chiral symmetry and quark-loop models. 58 refs., 5 figs
Electromagnetism and interconnections
Charruau, S
2009-01-01
This book covers the theoretical problems of modeling electrical behavior of the interconnections encountered in everyday electronic products. The coverage shows the theoretical tools of waveform prediction at work in the design of a complex and high-speed digital electronic system. Scientists, research engineers, and postgraduate students interested in electromagnetism, microwave theory, electrical engineering, or the development of simulation tools software for high speed electronic system design automation will find this book an illuminating resource.
Electromagnetic radiation of electrons in periodic structures
International Nuclear Information System (INIS)
Potylitsyn, Alexander Petrovich
2011-01-01
Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation and the Smith-Purcell effect. Characteristics of such radiation sources and perspectives of their usage are discussed. The recent experimental results as well as their interpretation are presented. (orig.)
Some Considerations Regarding Plane to Plane Parallelism Error Effects in Robotic Systems
Directory of Open Access Journals (Sweden)
Stelian Alaci
2015-06-01
Full Text Available The paper shows that by imposing the parallelism constraint between the measured plane and the reference plane, the position of the current plane is not univocal specified and is impossible to specify the way to attain the parallelism errors imposed by accuracy constrains. The parameters involved in the calculus of plane to plane parallelism error can be used to set univocal the relative position between the two planes.
Electromagnetic force on a brane
International Nuclear Information System (INIS)
Li, Li-Xin
2016-01-01
A fundamental assumption in the theory of brane world is that all matter and radiation are confined on the four-dimensional brane and only gravitons can propagate in the five-dimensional bulk spacetime. The brane world theory did not provide an explanation for the existence of electromagnetic fields and the origin of the electromagnetic field equation. In this paper, we propose a model for explaining the existence of electromagnetic fields on a brane and deriving the electromagnetic field equation. Similar to the case in Kaluza–Klein theory, we find that electromagnetic fields and the electromagnetic field equation can be derived from the five-dimensional Einstein field equation. However, the derived electromagnetic field equation differs from the Maxwell equation by containing a term with the electromagnetic potential vector coupled to the spacetime curvature tensor. So it can be considered as generalization of the Maxwell equation in a curved spacetime. The gravitational field equation on the brane is also derived with the stress–energy tensor for electromagnetic fields explicitly included and the Weyl tensor term explicitly expressed with matter fields and their derivatives in the direction of the extra-dimension. The model proposed in the paper can be regarded as unification of electromagnetic and gravitational interactions in the framework of brane world theory. (paper)
Optically controlled polarization in highly oriented ferroelectric thin films
Borkar, Hitesh; Tomar, M.; Gupta, Vinay; Katiyar, Ram S.; Scott, J. F.; Kumar, Ashok
2017-08-01
The out-of-plane and in-plane polarization of (Pb0.6Li0.2Bi0.2)(Zr0.2Ti0.8)O3 (PLBZT) thin film has been studied in the dark and under illumination from a weak light source of a comparable bandgap. A highly oriented PLBZT thin film was grown on a LaNiO3/LaAlO3 substrate by pulsed laser deposition; it showed well-saturated polarization which was significantly enhanced under light illumination. We employed two configurations for polarization characterization: the first deals with out-of-plane polarization with a single capacitor under investigation, whereas the second uses two capacitors connected in series via the bottom electrode. Two different configurations were illuminated using different energy sources and their effects were studied. The latter configuration shows a significant change in polarization under light illumination that may provide an extra degree of freedom for device miniaturization. The polarization was also tested using positive-up and negative-down measurements, confirming robust polarization and its switching under illumination.
International Nuclear Information System (INIS)
Denisov, V.I.; Krivchenkov, I.V.; Denisov, I.P.
2002-01-01
The study on the electromagnetic waves propagation in the neutron star magnetic dipole and gravitation fields, taking place according to the vacuum nonlinear electrodynamics laws, is carried out. It is shown that depending on the polarization the electromagnetic signals in this field propagate by different beams and with various velocities. The law on these signals motion by beams is established. The calculation of differences in the times of the electromagnetic signals propagation, having the same source up to the detector, is presented. It is shown that this difference in some cases may reach enough measurable value of 1 μs [ru
Combinatorial geometry in the plane
Hadwiger, Hugo; Klee, Victor
2014-01-01
Geared toward advanced undergraduates familiar with analysis and college geometry, this concise book discusses theorems on topics restricted to the plane such as convexity, coverings, and graphs. In addition to helping students cultivate rigorous thought, the text encourages the development of mathematical intuition and clarifies the nature of mathematical research.The two-part treatment begins with specific topics including integral distances, covering problems, point set geometry and convexity, simple paradoxes involving point sets, and pure combinatorics, among other subjects. The second pa
SNAP Satellite Focal Plane Development
International Nuclear Information System (INIS)
Bebek, C.; Akerlof, C.; Aldering, G.; Amanullah, R.; Astier, P.; Baltay, C.; Barrelet, E.; Basa, S.; Bercovitz, J.; Bergstrom, L.; Berstein, G.P.; Bester, M.; Bohlin, R.; Bonissent, A.; Bower, C.; Campbell, M.; Carithers, W.; Commins, E.; Day, C.; Deustua, S.; DiGennaro, R.; Ealet, A.; Ellis, R.; Emmett, W.; Eriksson, M.; Fouchez, D.; Fruchter, A.; Genat, J-F.; Goldhaber, G.; Goobar, A.; Groom, D.; Heetderks, H.; Holland, S.; Huterer, D.; Johnson, W.; Kadel, R.; Karcher, A.; Kim, A.; Kolbe, W.; Lafever, R.; Lamoureaux, J.; Lampton, M.; Lefevre, O.; Levi, M.; Levin, D.; Linder, E.; Loken, S.; Malina, R.; Mazure, A.; McKay, T.; McKee, S.; Miquel, R.; Morgan, N.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Roe, N.; Nugent, P.; Oluseyi, H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Prieto, E.; Rabinowitz, D.; Refregier, A.; Rhodes, J.; Schubnell, M.; Sholl, M.; Smadja, G.; Smith, R.; Smoot, G.; Snyder, J.; Spadafora, A.; Szymkowiak, A.; Tarle, G.; Taylor, K.; Tilquin, A.; Tomasch, A.; Vincent, D.; von der Lippe, H.; Walder, J-P.; Wang, G.
2003-01-01
The proposed SuperNova/Acceleration Probe (SNAP) mission will have a two-meter class telescope delivering diffraction-limited images to an instrumented 0.7 square degree field in the visible and near-infrared wavelength regime. The requirements for the instrument suite and the present configuration of the focal plane concept are presented. A two year R and D phase, largely supported by the Department of Energy, is just beginning. We describe the development activities that are taking place to advance our preparedness for mission proposal in the areas of detectors and electronics
Decay of a weakly bound level in a monochromatic electromagnetic field and a static magnetic field
International Nuclear Information System (INIS)
Rylyuk, V.M.; Ortner, J.
2003-01-01
We consider an electron that is bound by a zero-range potential and a constant magnetic field and which becomes disturbed by a monochromatic laser beam with elliptical polarization. The exact solution of the Schroedinger equation for an electron in the presence of an arbitrary electromagnetic wave and a static magnetic field is obtained. Exact expressions have been found for the complex energy, whose real and imaginary parts yield the level position and the width of an electron in a zero-range force field, a constant magnetic field, and a monochromatic electromagnetic field. These expressions have been analyzed in details for the case of a circularly polarized laser light
Polarization division multiple access with polarization modulation for LOS wireless communications
Directory of Open Access Journals (Sweden)
Cao Bin
2011-01-01
Full Text Available Abstract In this paper, we discuss a potential multiple access and modulation scheme based on polarized states (PS of electromagnetic (EM waves for line-of-sight (LOS communications. The proposed scheme is theoretic different from the existing polar modulation for EDGE and WCDMA systems. We propose the detailed bit representation (modulation and multiple access scheme using PS. Because of the inflexibility of polarization information in the time and frequency domains, as well as independence of frequency and space, the polarization information can be used independently for wireless communications, i.e., another independent resource domain that can be utilized. Due to the independence between the PS and the specific features of signals (such as waveform, bandwidth and data rate, the discussed polarization division multiple access (PDMA and polarization modulation (PM are expected to improve the spectrum utilization effectively. It is proved that the polarization filtering technique can be adopted in the PDMA-PM wireless communications to separate the multiuser signals and demodulate the bit information representing by PS for desired user. Some theoretical analysis is done to demonstrate the feasibility of the proposed scheme, and the simulation results are made to evaluate the performance of the suggested system.
[Fluorescence polarization immunoassay of ractopamine].
Zvereva, E A; Shpakova, N A; Zherdev, A V; Kiu, L; Xu, C; Eremin, S A; Dzantiev, B B
2016-01-01
A technique was developed for fluorescence polarization immunoassay (FPIA) of ractopamine, a toxic low molecular weight nonsteroidal growth regulator belonging to the most controlled contaminants of food products of animal origin. The assay is based on the competition between a sample containing ractopamine and ractopamine–fluorophore conjugate for binding to antibodies. The competition is monitored via changes in the degree of fluorescence polarization for plane-polarized excitation light, which differs for the free and antibody-bound forms of the conjugate. The optimal assay conditions were established, ensuring a high accuracy and minimal detection limit. The developed assay demonstrated a detection limit of 1 ng/mL and a range of detectable concentrations of 2.3–50 ng/mL, which met the requirements of sanitary control. The duration of the analysis was 10 min. The possible application of the developed FPIA was demonstrated with testing of turkey meat. The speed and simplicity of the proposed assay define its efficiency as a screening tool for safety of foods.
Energy Technology Data Exchange (ETDEWEB)
Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)
1994-12-01
The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.
Slip patterns and preferred dislocation boundary planes
DEFF Research Database (Denmark)
Winther, G.
2003-01-01
and polycrystals of fcc metals in three deformation modes (rolling, tension and torsion). In the macroscopic system, boundaries lie close to the macroscopically most stressed planes. In the crystallographic system, the boundary plane depends on the grain/crystal orientation. The boundary planes in both co...
Fast breeder reactor electromagnetic pump
International Nuclear Information System (INIS)
Araseki, Hideo; Murakami, Takahiro
2008-01-01
Main pumps circulating sodium in the FBR type reactor have been mechanical types, not electromagnetic pumps. Electromagnetic pump of 1-2 m 3 /min has been used as an auxiliary pump. Large sized electromagnetic pumps such as several hundred m 3 /min have not been commercialized due to technical difficulties with electromagnetic instability and pressure pulsations. This article explained electromagnetic and fluid equations and magnetic Reynolds number related with electromagnetic pumps and numerical analysis of instability characteristics and pressure pulsations and then described applications of the results to FBR system. Magnetic Reynolds number must be chosen less than one with appropriate operating frequency and optimum slip of 0.2-0.4. (T. Tanaka)
Directory of Open Access Journals (Sweden)
Ryotaro Ozaki
2015-09-01
Full Text Available Polarization characteristics of defect mode peaks in a one-dimensional (1D photonic crystal (PC with a nematic liquid crystal (NLC defect layer have been investigated. Two different polarized defect modes are observed in a stop band. One group of defect modes is polarized along the long molecular axis of the NLC, whereas another group is polarized along its short axis. Polarizations of the defect modes can be tuned by field-induced in-plane reorientation of the NLC in the defect layer. The polarization properties of the 1D PC with the NLC defect layer is also investigated by the finite difference time domain (FDTD simulation.
National Research Council Canada - National Science Library
Fini, P
2007-01-01
...) wafers that will act as seeds for subsequent GaN boule growth in Phase II. Inlustra developed non-polar a-plane and m-plane GaN films with smooth surfaces and minimal wafer bowing and cracking...
Electromagnetic Devices for Stopping Vehicles
Jan Valouch
2016-01-01
An effective way to stop a vehicle is to disrupt the operation of electronic systems using high power electromagnetic pulses, which can be generated using electromagnetic weapons. This article describes the design idea of a stationary generator of electromagnetic pulses that would be useful for stopping vehicles at the entrances to the object, at checkpoints, and in front of sensitive infrastructure. An important aspect of the proposal is the comparison of contemporary devices and systems use...
Radiation leakage from electromagnetic oven
Khalil, Abdurrahman; Ali, Runak Tahir; Fattah, Nabeel Abdulrazzaq
2015-01-01
Background: Microwaves are a form of electromagnetic energy, like light waves or radio waves, and occupy a part of the electromagnetic spectrum of power, or energy. Microwaves are very short waves of electromagnetic energy that travel at the speed of light (186,282 miles per second). In our modern technological age, microwaves are used to relay long distance telephone signals, television programs, and computer information across the earth or to a satellite in space. But the microwave is most ...
The Role of Angular Momentum in the Construction of Electromagnetic Multipolar Fields
Tischler, Nora; Zambrana-Puyalto, Xavier; Molina-Terriza, Gabriel
2012-01-01
Multipolar solutions of Maxwell's equations are used in many practical applications and are essential for the understanding of light-matter interactions at the fundamental level. Unlike the set of plane wave solutions of electromagnetic fields, the multipolar solutions do not share a standard derivation or notation. As a result, expressions…
Rojas, R.; Robles, P.
2011-01-01
We discuss common features in mechanical, electromagnetic and quantum systems, supporting identical results for the transmission and reflection coefficients of waves arriving perpendicularly at a plane interface. Also, we briefly discuss the origin of special notions such as refractive index in quantum mechanics, massive photons in wave guides and…
Electromagnetic Devices for Stopping Vehicles
Directory of Open Access Journals (Sweden)
Jan Valouch
2016-10-01
Full Text Available An effective way to stop a vehicle is to disrupt the operation of electronic systems using high power electromagnetic pulses, which can be generated using electromagnetic weapons. This article describes the design idea of a stationary generator of electromagnetic pulses that would be useful for stopping vehicles at the entrances to the object, at checkpoints, and in front of sensitive infrastructure. An important aspect of the proposal is the comparison of contemporary devices and systems used for stopping vehicles and analysis of the requirements of technical standards for electromagnetic immunity of vehicles.
Electromagnetic fields in biological systems
National Research Council Canada - National Science Library
Lin, James C
2012-01-01
"Focusing on exposure, induced fields, and absorbed energy, this volume covers the interaction of electromagnetic fields and waves with biological systems, spanning static fields to terahertz waves...
Battlefield Electromagnetic Environments Office (BEEO)
Federal Laboratory Consortium — The Battlefield Electromagnetic Environments Office (BEEO) develops, maintains, and operates the Army Materiel Command (AMC) databases for spectrum management, per...
Method of moments in electromagnetics
Gibson, Walton C
2007-01-01
Responding to the need for a clear, up-to-date introduction to the field, The Method of Moments in Electromagnetics explores surface integral equations in electromagnetics and presents their numerical solution using the method of moments (MOM) technique. It provides the numerical implementation aspects at a nuts-and-bolts level while discussing integral equations and electromagnetic theory at a higher level. The author covers a range of topics in this area, from the initial underpinnings of the MOM to its current applications. He first reviews the frequency-domain electromagnetic theory and t
Nonlinear Magnetic Phenomena in Highly Polarized Target Materials
Kiselev, Yu F
2007-01-01
The report introduces and surveys nonlinear magnetic phenomena which have been observed at high nuclear polarizations in polarized targets of the SMC and of the COMPASS collaborations at CERN. Some of these phenomena, namely the frequency modulation eect and the distortion of the NMR line shape, promote the development of the polarized target technique. Others, as the spin-spin cross-relaxation between spin subsystems can be used for the development of quantum statistical physics. New findings bear on an electromagnetic noise and the spectrally resolved radiation from LiD with negatively polarized nuclei detected by low temperature bolometers. These nonlinear phenomena need to be taken into account for achieving the ultimate polarizations.
Systems considerations in mosaic focal planes
White, K. P., III
1983-08-01
Two key reasons for pursuing the development of mosaic focal planes are reviewed and it is shown that rapid frame repetition rate is the only requirement that can be solved no other way than through mosaic focal planes. With the view that spaceborne mosaic focal plane sensors are necessarily 'smart sensors' requiring a lot of onboard processing just to function, it is pointed out that various artificial intelligence techniques may be the most appropriate to incorporate in the data processing. Finally, a novel mosaic focal plane design is proposed, termed a virtual mosaic focal plane, in response to other system constraints.
An introduction to finite projective planes
Albert, Abraham Adrian
2015-01-01
Geared toward both beginning and advanced undergraduate and graduate students, this self-contained treatment offers an elementary approach to finite projective planes. Following a review of the basics of projective geometry, the text examines finite planes, field planes, and coordinates in an arbitrary plane. Additional topics include central collineations and the little Desargues' property, the fundamental theorem, and examples of finite non-Desarguesian planes.Virtually no knowledge or sophistication on the part of the student is assumed, and every algebraic system that arises is defined and
Theory of electromagnetic insertion devices and the corresponding synchrotron radiation
Directory of Open Access Journals (Sweden)
Muhammad Shumail
2016-07-01
Full Text Available Permanent magnet insertion devices (IDs, which are the main radiation generating devices in synchrotron light sources and free-electron lasers, use a time-invariant but space-periodic magnetic field to wiggle relativistic electrons for short-wavelength radiation generation. Recently, a high power microwave based undulator has also been successfully demonstrated at SLAC which promises the advantage of dynamic tunability of radiation spectrum and polarization. Such IDs employ transverse elecromagnetic fields which are periodic in both space and time to undulate the electrons. In this paper we develop a detailed theory of the principle of electromagnetic IDs from first principles for both linear and circular polarization modes. The electromagnetic equivalent definitions of undulator period (λ_{u} and undulator deflection parameter (K are derived. In the inertial frame where the average momentum of the electron is zero, we obtain the figure-8-like trajectory for the linear polarization mode and the circular trajectory for the circular polarization mode. The corresponding radiation spectra and the intensity of harmonics is also calculated.
Highlights in the hadron electromagnetic structure
Directory of Open Access Journals (Sweden)
Tomasi-Gustafsson Egle
2017-01-01
Full Text Available In frame of a general view of proton electromagnetic form factors, two recent findings related to reanalyses of data are presented. Recent experiments in the scattering and in the annihilation region provided us with more precise data and/or extending the kinematical region, allowing a deeper analysis and a common view of these fundamental quantities. We will discuss two issues: the discrepancy between the form factors extracted from unpolarized and polarized ep elastic scattering experiments, in connection with the commonly used dipole parametrization; peculiar oscillations in e+e− → p̄p(γ annihilation cross section, that become periodical when plotted as a function of the 3-momentum of the relative motion of the final proton and antiproton, after subtraction of a smooth function.
Flatland Position-Dependent-Mass: Polar Coordinates, Separability and Exact Solvability
Mazharimousavi, S. Habib; Mustafa, Omar
2010-10-01
The kinetic energy operator with position-dependent-mass in plane polar coordinates is obtained. The separability of the corresponding Schrödinger equation is discussed. A hypothetical toy model is reported and two exactly solvable examples are studied.
Electromagnetic Fields Exposure Limits
2018-01-01
Standard 5-2 Figure 5-3 Graphical Depiction of the IEEE C95.1TM-2005 Pulse RF Standard 5-3 with Thermally -Based Standard Extended Figure 5-4...Electromagnetic Ground Environment STO-TR-HFM-189 ix SLED Stanford Linear Energy Doubler SME Subject-Matter Expert SOH Safety and Occupational Health...as grasping versus touch. ICC will be a secondary project that will be addressed and scheduled as time permits and as laboratories are found to have
Handbook of electromagnetic compatibility
1995-01-01
This""know-how""book gives readers a concise understanding of the fundamentals of EMC, from basic mathematical and physical concepts through present, computer-age methods used in analysis, design, and tests. With contributions from leading experts in their fields, the text provides a comprehensive overview. Fortified with information on how to solve potential electromagnetic interference (EMI) problems that may arise in electronic design, practitioners will be betterable to grasp the latest techniques, trends, and applications of this increasingly important engineering discipline.Handbook of E
Introduction to electromagnetic engineering
Harrington, Roger E
2003-01-01
This study of electromagnetic theory introduces students to a broad range of quantities and concepts, imparting the necessary vector analysis and associated mathematics and reinforcing its teachings with several elementary field problems. Based on circuit theory rather than on the classical force-relationship approach, the text uses the theory of electric circuits to provide a system of experiments already familiar to the electrical engineer; a series of field concepts are then introduced as a logical extension of circuit theory. Virtually unobtainable elsewhere, this text was written by a pr
Functional Aesthetic Occlusal Plane (FAOP
Directory of Open Access Journals (Sweden)
Carlos Alexandre Câmara
Full Text Available ABSTRACT Introduction: A reasonable exposure of incisors and gingival tissues is generally considered more attractive than excess or lack of exposure. A reasonable gingival exposure is considered to be around 0 to 2 mm when smiling and 2-4 mm exposure of the maxillary incisor edge when the lips are at rest. Objective: The aim of this paper is to present the Functional Aesthetic Occlusal Plane (FAOP, which aims to help in the diagnosis of the relationships established among molars, incisors and the upper lip. Conclusion: FAOP can complement an existing and established orthodontic treatment plan, facilitating the visualization of functional and aesthetic demands by giving a greater focus on the position of incisors in the relationship established among the incisors, molars and the upper lip stomion.
Functional Aesthetic Occlusal Plane (FAOP).
Câmara, Carlos Alexandre; Martins, Renato Parsekian
2016-01-01
A reasonable exposure of incisors and gingival tissues is generally considered more attractive than excess or lack of exposure. A reasonable gingival exposure is considered to be around 0 to 2 mm when smiling and 2-4 mm exposure of the maxillary incisor edge when the lips are at rest. The aim of this paper is to present the Functional Aesthetic Occlusal Plane (FAOP), which aims to help in the diagnosis of the relationships established among molars, incisors and the upper lip. FAOP can complement an existing and established orthodontic treatment plan, facilitating the visualization of functional and aesthetic demands by giving a greater focus on the position of incisors in the relationship established among the incisors, molars and the upper lip stomion.
Geometric Phase Of The Faraday Rotation Of Electromagnetic Waves In Magnetized Plasma
Energy Technology Data Exchange (ETDEWEB)
Jian Liu and Hong Qin
2011-11-07
The geometric phase of circularly polarized electromagnetic waves in nonuniform magnetized plasmas is studied theoretically. The variation of the propagation direction of circularly polarized waves results in a geometric phase, which also contributes to the Faraday rotation, in addition to the standard dynamical phase. The origin and properties of the geometric phase is investigated. The in uence of the geometric phase to plasma diagnostics using Faraday rotation is also discussed as an application of the theory.
Electromagnetic scattering from large steady breaking waves
Energy Technology Data Exchange (ETDEWEB)
Coakley, D.B.; Haldeman, P.M.; Morgan, D.G.; Nicolas, K.R.; Penndorf, D.R.; Wetzel, L.B.; Weller, C.S. [David Taylor Model Basin, Naval Surface Warfare Center Carderock Div., West Bethesda, MD (United States)
2001-05-01
A submerged hydrofoil generated large steady breaking waves of 0.3 m and 0.4 m height in a circulating water channel. We measured water fraction in the breakers with conductivity probes. We observed the radar cross-section of the breakers at X-band with a pulsed step-frequency instrumentation radar with high spatial resolution in the downstream direction. The normalized radar cross-section increases with increasing elevation angle of observation for both vertical and horizontal polarization. This variation is consistent with a simple interpretation of the breaking wave as a diffuse (Lambertian) surface. However, the observed sizes and shapes of fluid elements in the breakers clearly show that construction of a theory for electromagnetic scattering from first principles will be challenging. We also obtained the velocity spectrum of the scattering features within the breakers. This spectrum indicates that slower moving small liquid elements rather than the faster moving large disturbances are responsible for most of the electromagnetic scattering. (orig.)
A Logarithmic-Amplitude Polar Diagram
Directory of Open Access Journals (Sweden)
Trond Andresen
2001-04-01
Full Text Available A polar diagram where the amplitude of the transfer function is on a logarithmic scale, is presented. This gives a one-size-fits-all diagram with no need for zooming in and out, and no need for additional reasoning about infinite-radius encirclements when there are poles on the imaginary axis - as opposed to what is usually neccessary with the standard polar (Nyquist- diagram. All properties needed for stability considerations are upheld, such as encirclements, gain and phase margins. The path for s in the loop transfer function is carefully chosen with regard to possible poles on the imaginary axis. Small excursions into the right half plane in the form of arcs of different-sized logarithmic spirals result in corresponding large but finite arcs that do not overlap in the logarithmic polar plots.
Scattering on plane waves and the double copy
Adamo, Tim; Casali, Eduardo; Mason, Lionel; Nekovar, Stefan
2018-01-01
Perturbatively around flat space, the scattering amplitudes of gravity are related to those of Yang–Mills by colour-kinematic duality, under which gravitational amplitudes are obtained as the ‘double copy’ of the corresponding gauge theory amplitudes. We consider the question of how to extend this relationship to curved scattering backgrounds, focusing on certain ‘sandwich’ plane waves. We calculate the 3-point amplitudes on these backgrounds and find that a notion of double copy remains in the presence of background curvature: graviton amplitudes on a gravitational plane wave are the double copy of gluon amplitudes on a gauge field plane wave. This is non-trivial in that it requires a non-local replacement rule for the background fields and the momenta and polarization vectors of the fields scattering on the backgrounds. It must also account for new ‘tail’ terms arising from scattering off the background. These encode a memory effect in the scattering amplitudes, which naturally double copies as well.
Geographical Income Polarization
DEFF Research Database (Denmark)
Azhar, Hussain; Jonassen, Anders Bruun
inter municipal income inequality. Counter factual simulations show that rising property prices to a large part explain the rise in polarization. One side-effect of polarization is tendencies towards a parallel polarization of residence location patterns, where low skilled individuals tend to live......In this paper we estimate the degree, composition and development of geographical income polarization based on data at the individual and municipal level in Denmark from 1984 to 2002. Rising income polarization is reconfirmed when applying new polarization measures, the driving force being greater...
Novel calibration system with sparse wires for CMB polarization receivers
Energy Technology Data Exchange (ETDEWEB)
Tajima, O.; /KEK, Tsukuba /Chicago U., KICP; Nguyen, H.; /Fermilab; Bischoff, C.; /Chicago U., KICP /Harvard-Smithsonian Ctr. Astrophys.; Brizius, A.; Buder, I.; Kusaka, A. /Chicago U., KICP
2011-07-01
B-modes in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate 'simultaneously' all detectors on the large focal plane. We developed a novel calibration system that rotates a large 'sparse' grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature from the wire surface. Since the detector has a finite beam size, the observed signal is smeared according to the beam property. The resulting smeared polarized radiation has a reasonable intensity (a few Kelvin or less) compared to the sky temperature ({approx}10 K observing condition). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.
Energy density and velocity of electromagnetic waves in lossy chiral medium
International Nuclear Information System (INIS)
Vorobyev, O B
2014-01-01
The average energy density of the macroscopic quasimonochromatic electromagnetic field U ts (t,r) in a linear passive chiral lossy medium described by the constitutive E–H relations is determined using a microscopic model. According to the model, U ts (t,r) is equal to the sum of the average energy densities of the electromagnetic field in free space U t0 (t,r) and electromagnetic oscillations in structural elements U s (t,r) induced by the electromagnetic wave. Making use of the Poynting theorem, the energy density U ts (t,r)≥U t0 (t,r) and power density of losses are derived as functions of the Poynting vector, polarization of the electromagnetic waves, phase shift between the field vectors and refractive index of a chiral medium. The exact energy velocity of the quasimonochromatic electromagnetic waves satisfying relativistic causality is determined using U ts (t,r). The approximate energy velocities of the quasimonochromatic electromagnetic wave are determined using energy density components approximating U ts (t,r) (e.g., the sum of the positive energy densities of the macroscopic electric and magnetic fields as well as the energy density of magnetoelectric cross-coupling). Comparison of the exact and approximate energy velocities with the group velocity in the case of a chiral lossy medium with a single-resonant frequency clarifies the concept of the electromagnetic energy and demonstrates the fundamental significance of the exact energy velocity. (paper)
Metamaterials beyond electromagnetism
Kadic, Muamer; Bückmann, Tiemo; Schittny, Robert; Wegener, Martin
2013-12-01
Metamaterials are rationally designed man-made structures composed of functional building blocks that are densely packed into an effective (crystalline) material. While metamaterials are mostly associated with negative refractive indices and invisibility cloaking in electromagnetism or optics, the deceptively simple metamaterial concept also applies to rather different areas such as thermodynamics, classical mechanics (including elastostatics, acoustics, fluid dynamics and elastodynamics), and, in principle, also to quantum mechanics. We review the basic concepts, analogies and differences to electromagnetism, and give an overview on the current state of the art regarding theory and experiment—all from the viewpoint of an experimentalist. This review includes homogeneous metamaterials as well as intentionally inhomogeneous metamaterial architectures designed by coordinate-transformation-based approaches analogous to transformation optics. Examples are laminates, transient thermal cloaks, thermal concentrators and inverters, ‘space-coiling’ metamaterials, anisotropic acoustic metamaterials, acoustic free-space and carpet cloaks, cloaks for gravitational surface waves, auxetic mechanical metamaterials, pentamode metamaterials (‘meta-liquids’), mechanical metamaterials with negative dynamic mass density, negative dynamic bulk modulus, or negative phase velocity, seismic metamaterials, cloaks for flexural waves in thin plates and three-dimensional elastostatic cloaks.
Electromagnetic Field Penetration Studies
Deshpande, M.D.
2000-01-01
A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.
International Nuclear Information System (INIS)
Dean, S.A.
1980-01-01
Full details of the invention are given. A sensing unit assembly for an electromagnetic flux distortion flowmeter for use in liquid metal coolant of a nuclear reactor is described. The assembly comprises coils of electrically insulated conductors each wound on an individual former. The formers and coils are mounted coaxially on a spine to form at least three spaced groups arranged end to end. Each group comprises two secondary coils and an intermediate primary coil. Leads extend along a duct formed in the spine, each lead terminating at a common end. Alternative versions of the assembly are also described. The primary coil leads are connected to an alternating power supply; those for the secondary coils connected to suitable display instrumentation. When liquid metal flows along the conductor the electromagnetic field is disturbed and the induced voltage in the secondary coils is disturbed-(set at zero for no flow); the distortion depends on the rate of flow. When the induced voltage differential of at least two of the groups falls or rises outside a pre-set level a trip signal is initiated to shut down the reactor. (UK)
Metamaterials beyond electromagnetism.
Kadic, Muamer; Bückmann, Tiemo; Schittny, Robert; Wegener, Martin
2013-12-01
Metamaterials are rationally designed man-made structures composed of functional building blocks that are densely packed into an effective (crystalline) material. While metamaterials are mostly associated with negative refractive indices and invisibility cloaking in electromagnetism or optics, the deceptively simple metamaterial concept also applies to rather different areas such as thermodynamics, classical mechanics (including elastostatics, acoustics, fluid dynamics and elastodynamics), and, in principle, also to quantum mechanics. We review the basic concepts, analogies and differences to electromagnetism, and give an overview on the current state of the art regarding theory and experiment-all from the viewpoint of an experimentalist. This review includes homogeneous metamaterials as well as intentionally inhomogeneous metamaterial architectures designed by coordinate-transformation-based approaches analogous to transformation optics. Examples are laminates, transient thermal cloaks, thermal concentrators and inverters, 'space-coiling' metamaterials, anisotropic acoustic metamaterials, acoustic free-space and carpet cloaks, cloaks for gravitational surface waves, auxetic mechanical metamaterials, pentamode metamaterials ('meta-liquids'), mechanical metamaterials with negative dynamic mass density, negative dynamic bulk modulus, or negative phase velocity, seismic metamaterials, cloaks for flexural waves in thin plates and three-dimensional elastostatic cloaks.
Arrayás, M.; Bouwmeester, D.; Trueba, J. L.
2017-01-01
Maxwell equations in vacuum allow for solutions with a non-trivial topology in the electric and magnetic field line configurations at any given moment in time. One example is a space filling congruence of electric and magnetic field lines forming circles lying on the surfaces of nested tori. In this example the electric, magnetic and Poynting vector fields are orthogonal everywhere. As time evolves the electric and magnetic fields expand and deform without changing the topology and energy, while the Poynting vector structure remains unchanged while propagating with the speed of light. The topology is characterized by the concept of helicity of the field configuration. Helicity is an important fundamental concept and for massless fields it is a conserved quantity under conformal transformations. We will review several methods by which linked and knotted electromagnetic (spin-1) fields can be derived. A first method, introduced by A. Rañada, uses the formulation of the Maxwell equations in terms of differential forms combined with the Hopf map from the three-sphere S3 to the two-sphere S2. A second method is based on spinor and twistor theory developed by R. Penrose in which elementary twistor functions correspond to the family of electromagnetic torus knots. A third method uses the Bateman construction of generating null solutions from complex Euler potentials. And a fourth method uses special conformal transformations, in particular conformal inversion, to generate new linked and knotted field configurations from existing ones. This fourth method is often accompanied by shifting singularities in the field to complex space-time points. Of course the various methods must be closely related to one another although they have been developed largely independently and they suggest different directions in which to expand the study of topologically non-trivial field configurations. It will be shown how the twistor formulation allows for a direct extension to massless
Exploration of the Electromagnetic Environment
Fullekrug, M.
2009-01-01
The electromagnetic environment is composed of electric and magnetic fields which result from man-made and natural sources. An elementary experiment is described to explore the electromagnetic environment by measuring electric fields in the frequency range from approximately equal to 10 to 24 000 Hz. The equipment required to conduct the…
Electromagnetic compatibility in power electronics
Costa , François; Revol , Bertrand
2014-01-01
Scientists largely attribute the recent deterioration of the electromagnetic environment to power electronics. This realization has spurred the study of methodical approaches to electromagnetic compatibility designs as explored in this text. The book addresses major challenges, such as handling numerous parameters vital to predicting electro magnetic effects and achieving compliance with line-harmonics norms, while proposing potential solutions.
Electromagnetic actuation in MEMS switches
DEFF Research Database (Denmark)
Oliveira Hansen, Roana Melina de; Mátéfi-Tempfli, Mária; Chemnitz, Steffen
. Electromagnetic actuation is a very promising approach to operate such MEMS and Power MEMS devices, due to the long range, reproducible and strong forces generated by this method, among other advantages. However, the use of electromagnetic actuation in such devices requires the use of thick magnetic films, which...
Canonical quantization of macroscopic electromagnetism
Philbin, Thomas Gerard
2010-01-01
Application of the standard canonical quantization rules of quantum field theory to macroscopic electromagnetism has encountered obstacles due to material dispersion and absorption. This has led to a phenomenological approach to macroscopic quantum electrodynamics where no canonical formulation is attempted. In this paper macroscopic electromagnetism is canonically quantized. The results apply to any linear, inhomogeneous, magnetodielectric medium with dielectric functions that obey the Krame...
Directory of Open Access Journals (Sweden)
Farman Ali Mangi
2016-01-01
Full Text Available A multiband circular polarizer based on fission transmission of linearly polarized wave for x-band application is proposed, which is constructed of 2 × 2 metallic strips array. The linear-to-circular polarization conversion is obtained by decomposing the linearly incident x-polarized wave into two orthogonal vector components of equal amplitude and 90° phase difference between them. The innovative approach of “fission transmission of linear-to-circular polarized wave” is firstly introduced to obtain giant circular dichroism based on decomposition of orthogonal vector components through the structure. It means that the incident linearly polarized wave is converted into two orthogonal components through lower printed metallic strips layer and two transmitted waves impinge on the upper printed strips layer to convert into four orthogonal vector components at the end of structure. This projection and transmission sequence of orthogonal components sustain the chain transmission of electromagnetic wave and can achieve giant circular dichroism. Theoretical analysis and microwave experiments are presented to validate the performance of the structure. The measured results are in good agreement with simulation results. In addition, the proposed circular polarizer exhibits the optimal performance with respect to the normal incidence. The right handed circularly polarized wave is emitted ranging from 10.08 GHz to 10.53 GHz and 10.78 GHz to 11.12 GHz, while the left handed circular polarized wave is excited at 10.54 GHz–10.70 GHz and 11.13 GHz–11.14 GHz, respectively.
Metasurfaces for Terahertz Waves Polarization Control
DEFF Research Database (Denmark)
Lavrinenko, Andrei; Malureanu, Radu; Zalkovskij, Maksim
in the visible, near infrared or microwave regimes these issues in principle have strong alternatives via a conventional optics or electromagnetic approaches, at terahertz (THz) frequencies metamaterials are often considered as being the unique solution for the encountered problems. Several approaches involving...... that the maximal conversion efficiency with a single metamaterial surface is 50 % in transmission and up to 90% in reflection. However, a double layer transmission converter and a single layer with a metallic mirror can have 100% polarization conversion efficiency. We tested our conclusions numerically reaching...
Hybrid synchronous motor electromagnetic torque research
Directory of Open Access Journals (Sweden)
Suvorkova Elena E.
2014-01-01
Full Text Available Electromagnetic field distribution models in reluctance and permanent magnet parts were made by means of Elcut. Dependences of electromagnetic torque on torque angle were obtained.
Electromagnetic Interference (EMI) and TEMPEST Test Facility
Federal Laboratory Consortium — Electromagnetic Interference (EMI), Electromagnetic Compatibility (EMC) and TEMPEST testing are conducted at EPG's Blacktail Canyon Test Facility in one of its two...
Electromagnetic current in weak interactions
International Nuclear Information System (INIS)
Ma, E.
1983-01-01
In gauge models which unify weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current. The exact nature of such a component can be explored using e + e - experimental data. In recent years, the existence of a new component of the weak interaction has become firmly established, i.e., the neutral-current interaction. As such, it competes with the electromagnetic interaction whenever the particles involved are also charged, but at a very much lower rate because its effective strength is so small. Hence neutrino processes are best for the detection of the neutral-current interaction. However, in any gauge model which unifies weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current
Gravitational scattering of electromagnetic radiation
Brooker, J. T.; Janis, A. I.
1980-01-01
The scattering of electromagnetic radiation by linearized gravitational fields is studied to second order in a perturbation expansion. The incoming electromagnetic radiation can be of arbitrary multipole structure, and the gravitational fields are also taken to be advanced fields of arbitrary multipole structure. All electromagnetic multipole radiation is found to be scattered by gravitational monopole and time-varying dipole fields. No case has been found, however, in which any electromagnetic multipole radiation is scattered by gravitational fields of quadrupole or higher-order multipole structure. This lack of scattering is established for infinite classes of special cases, and is conjectured to hold in general. The results of the scattering analysis are applied to the case of electromagnetic radiation scattered by a moving mass. It is shown how the mass and velocity may be determined by a knowledge of the incident and scattered radiation.
Polarized Light Corridor Demonstrations.
Davies, G. R.
1990-01-01
Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)
Shielding of electromagnetic fields of current sources by spherical enclosures
Shastry, S. V. K.; Rao, M. N.; Katti, V. R.
Expressions for the shielding effectiveness of a conductive spherical enclosure excited by a Hertzian dipole have been derived using the dyadic Green's function technique. This technique has the advantage that the fields inside or outside the enclosure due to arbitrary current distribution may be found by employing the same set of dyadic Green's functions. The shielding effectiveness for plane wave incidence has been determined by considering the limiting case of the current source external to the spherical shell. Computed values of shielding effectiveness deduced in this manner have been compared with those obtained by the numerical evaluation of the expressions derived by earlier authors. The theory presented here may be useful to EMC (electromagnetic compatibility) engineers who must consider electromagnetic coupling from current sources in the vicinity of shielding enclosures.
Characterization of Meta-Materials Using Computational Electromagnetic Methods
Deshpande, Manohar; Shin, Joon
2005-01-01
An efficient and powerful computational method is presented to synthesize a meta-material to specified electromagnetic properties. Using the periodicity of meta-materials, the Finite Element Methodology (FEM) is developed to estimate the reflection and transmission through the meta-material structure for a normal plane wave incidence. For efficient computations of the reflection and transmission over a wide band frequency range through a meta-material a Finite Difference Time Domain (FDTD) approach is also developed. Using the Nicholson-Ross method and the Genetic Algorithms, a robust procedure to extract electromagnetic properties of meta-material from the knowledge of its reflection and transmission coefficients is described. Few numerical examples are also presented to validate the present approach.
Observation of electromagnetically induced Talbot effect in an atomic system
Zhang, Zhaoyang; Liu, Xing; Zhang, Dan; Sheng, Jiteng; Zhang, Yiqi; Zhang, Yanpeng; Xiao, Min
2018-01-01
The electromagnetically induced Talbot effect (EITE) resulting from the repeated self-reconstruction of a spatially intensity-modulated probe field is experimentally demonstrated in a three-level atomic configuration. The probe beam is launched into an optically induced lattice (established by the interference of two coupling fields) inside a rubidium vapor cell and is diffracted by the electromagnetically induced grating that was formed. The diffraction pattern repeats itself at the planes of integer multiple Talbot lengths. In addition, a fractional EITE is also investigated. The experimental observations agree well with the theoretical predictions. This investigation may potentially pave the way for studying the nonlinear and quantum dynamical features that have been predicted for established periodic optical systems.
Nonlinear multi-frequency electromagnetic wave propagation phenomena
Valovik, Dmitry V.
2017-11-01
A generalisation of the concept of monochromatic electromagnetic waves guided by layered waveguide structures filled with non-linear medium is introduced. This generalisation leads to guided waves of a novel type: a non-linear multi-frequency guided wave. The existence of such waves, in particular guide structures, is proven using the perturbation method. Numerical experiments are presented for non-linear 1- and 2-frequency guided waves in plane and cylindrical (with a circular cross-section) waveguides. Numerically, a novel non-linear effect is found for particular cases of non-linear multi-frequency guided waves. The suggested generalisation gives not only a unified approach to treat various electromagnetic wave propagation problems but also paves the way to study non-linear interactions of guided waves.
Directory of Open Access Journals (Sweden)
F. Dudkin
2010-07-01
Full Text Available A new approach is developed to find the source azimuth of the ultra low frequency (ULF electromagnetic (EM signals believed to be emanating from well defined seismic zone. The method is test applied on magnetic data procured from the seismoactive region of Koyna-Warna, known for prolonged reservoir triggered seismicity. Extremely low-noise, high-sensitivity LEMI-30 search coil magnetometers were used to measure simultaneously the vector magnetic field in the frequency range 0.001–32 Hz at two stations, the one located within and another ~100 km away from the seismic active zone. During the observation campaign extending from 15 March to 30 June 2006 two earthquakes (EQs of magnitude (M_{L}>4 occurred, which are searched for the presence of precursory EM signals.
Comparison of polarization ellipses (PE parameters formed by the magnetic field components at the measurement stations, in select frequency bands, allows discrimination of seismo-EM signals from the natural background ULF signals of magnetospheric/ionospheric origin. The magnetic field components corresponding to spectral bands dominated by seismo-EM fields define the PE plane which at any instant contains the source of the EM fields. Intersection lines of such defined PE planes for distant observation stations clutter in to the source region. Approximating the magnetic-dipole configuration for the source, the magnetic field components along the intersection lines suggest that azimuth of the EM source align in the NNW-SSE direction. This direction well coincides with the orientation of nodal plane of normal fault plane mechanism for the two largest EQs recorded during the campaign. More significantly the correspondence of this direction with the tectonic controlled trend in local seismicity, it has been surmised that high pressure fluid flow along the fault that facilitate EQs in the region may also be the source mechanism for EM fields by electrokinetic effect.
Adiabatic/diabatic polarization beam splitter
Energy Technology Data Exchange (ETDEWEB)
DeRose, Christopher; Cai, Hong
2017-09-12
The various presented herein relate to an on-chip polarization beam splitter (PBS), which is adiabatic for the transverse magnetic (TM) mode and diabatic for the transverse electric (TE) mode. The PBS comprises a through waveguide and a cross waveguide, wherein an electromagnetic beam comprising TE mode and TM mode components is applied to an input port of the through waveguide. The PBS can be utilized to separate the TE mode component from the TM mode component, wherein the TE mode component exits the PBS via an output port of the through waveguide, and the TM mode component exits the PBS via an output port of the cross waveguide. The PBS has a structure that is tolerant to manufacturing variations and exhibits high polarization extinction ratios over a wide bandwidth.
Radioactivity in the galactic plane
Walraven, G. D.; Haymes, R. C.
1976-01-01
The paper reports the detection of a large concentration of interstellar radioactivity during balloon-altitude measurements of gamma-ray energy spectra in the band between 0.02 and 12.27 MeV from galactic and extragalactic sources. Enhanced counting rates were observed in three directions towards the plane of the Galaxy; a power-law energy spectrum is computed for one of these directions (designated B 10). A large statistical deviation from the power law in a 1.0-FWHM interval centered near 1.16 MeV is discussed, and the existence of a nuclear gamma-ray line at 1.15 MeV in B 10 is postulated. It is suggested that Ca-44, which emits gamma radiation at 1.156 MeV following the decay of radioactive Sc-44, is a likely candidate for this line, noting that Sc-44 arises from Ti-44 according to explosive models of supernova nucleosynthesis. The 1.16-MeV line flux inferred from the present data is shown to equal the predicted flux for a supernova at a distance of approximately 3 kpc and an age not exceeding about 100 years.
Curves along which plane waves can interfere
Energy Technology Data Exchange (ETDEWEB)
Karp, S.N.; Machover, M.
1977-07-01
Partial results are given on a conjecture in inverse scattering theory concerning the interference of two-dimensional plane waves. The conjecture states that an odd number of plane waves of the same frequency can only cancel each other at isolated points and not along a simple continuous curve. It is partially confirmed here for curves which are nearly flat at some point. An analysis is also made for various possible nodes for an even number of plane waves.
Agarwal, G. S.; Dogariu, A.; Visser, T.D.; Wolf, E.
2005-01-01
The recently developed theory that unifies the treatments of polarization and coherence of random electro-magnetic beams is applied to study field correlations in Young's interference experiment. It is found that at certain pairs of points the transmitted field is spatially fully coherent,
International Nuclear Information System (INIS)
Aubert, B.; Ballansat, J.; Colas, J.
2005-01-01
We describe the electric circuits (electrodes) which polarize and read out the lead-liquid argon electromagnetic calorimeter for the ATLAS detector. The paper covers design and material choices of the circuits as well as their production in industry. We also show how the electrodes integrate into the calorimeter and conclude with results from groups of electrodes making up calorimeter modules
Effect of frequency variation on electromagnetic pulse interaction with charges and plasma
Khachatryan, A.G.; van Goor, F.A.; Verschuur, Jeroen W.J.; Boller, Klaus J.
2005-01-01
The effect of frequency variation (chirp) in an electromagnetic (EM) pulse on the pulse interaction with a charged particle and plasma is studied. Various types of chirp and pulse envelopes are considered. In vacuum, a charged particle receives a kick in the polarization direction after interaction
Polarized Moessbauer transitions
International Nuclear Information System (INIS)
Barb, D.
1975-01-01
Theoretical aspects of the emission, absorption and scattering of polarized gamma rays are reviewed for a general case of combined magnetic and electric hyperfine interactions; various possibilities of obtaining polarized gamma sources are described and examples are given of the applications of Moessbauer spectroscopy with polarized gamma rays in solving problems of solid state physics. (A.K.)
Scale dependence and small x behaviour of polarized parton distributions
Ball, R D; Ridolfi, G; Forte, S; Ridolfi, G
1995-01-01
We discuss perturbative evolution of the polarized structure function g_1 in the (x,Q^2) plane, with special regard to the small-x region. We determine g_1 in terms of polarized quark and gluon distributions using coefficient functions to order alpha_s. At small x g_1 then displays substantial scale dependence, which necessarily implies a corresponding scale dependence in the large-x region. This scale dependence has significant consequences for the extraction of the first moment from the experimental data, reducing its value while increasing the error. Conversely, the scale dependence may be used to constrain the size of the polarized gluon distribution.
US develops electromagnetic weapons
Energy Technology Data Exchange (ETDEWEB)
1986-01-01
The principles of electromagnetic weapons (EMWs) which accumulate and switch energy have been known for over 50 years, but the US has made significant progress in recent years in the development of single-pole generators. A design which eliminates the breaker and pulse generator and increases reliability of the EMWs is undergoing tests in the US. There will be significant advantages for the EMW used for air and antimissile defense. In addition to weapons of varying purpose and basing, the EMW can be effective as launchers, as an alternative to rocket engines. The EMW is an area in which the US is trying to achieve superiority, and is a violation of the 1972 Antimissile Defense Treaty. 4 figures.
Focusing of electromagnetic waves
International Nuclear Information System (INIS)
Dhayalan, V.
1996-01-01
The focusing of electromagnetic waves inside a slab has been examined together with two special cases in which the slab is reduced to a single interface or a single medium. To that end the exact solutions for the fields inside a layered medium have been used, given in terms of the outside current source in order to obtain the solutions for the focused electric field inside a slab. Both exact and asymptotic solutions of the problem have been considered, and the validity of the latter has been discussed. The author has developed a numerical algorithm for evaluation of the diffraction integral with special emphasis on reducing the computing time. The numerical techniques in the paper can be readily applied to evaluate similar diffraction integrals occurring e.g. in microstrip antennas. 46 refs
Solved problems in electromagnetics
Salazar Bloise, Félix; Bayón Rojo, Ana; Gascón Latasa, Francisco
2017-01-01
This book presents the fundamental concepts of electromagnetism through problems with a brief theoretical introduction at the beginning of each chapter. The present book has a strong didactic character. It explains all the mathematical steps and the theoretical concepts connected with the development of the problem. It guides the reader to understand the employed procedures to learn to solve the exercises independently. The exercises are structured in a similar way: The chapters begin with easy problems increasing progressively in the level of difficulty. This book is written for students of physics and engineering in the framework of the new European Plans of Study for Bachelor and Master and also for tutors and lecturers. .
Electromagnetic fields and life
Presman, A S
1970-01-01
A broad region of the electromagnetic spectrum long assumed to have no influence on living systems under natural conditions has been critically re-examined over the past decade. This spectral region extends from the superhigh radio frequencies, through de creasing frequencies, to and including essentially static electric and magnetic fields. The author of this monograph, A. S. Presman, has reviewed not only the extensive Russian literatur!;"l, but also all most equally comprehensively the non-Russian literature, dealing with biological influences of these fields. Treated also is literature shedding some light on possible theoretical foundations for these phenomena. A substantial, rapidly increasing number of studies in many laboratories and countries has now clearly established bio logical influences which are independent of the theoretically predictable, simple thermal effects. Indeed many of the effects are produced by field strengths very close to those within the natural environment. The author has,...
Electromagnetically revolving sphere viscometer
Hosoda, Maiko; Sakai, Keiji
2014-12-01
In this paper, we propose a new method of low viscosity measurement, in which the rolling of a probe sphere on the flat solid bottom of a sample cell is driven remotely and the revolution speed of the probe in a sample liquid gives the viscosity measurements. The principle of this method is based on the electromagnetically spinning technique that we developed, and the method is effective especially for viscosity measurements at levels below 100 mPa·s with an accuracy higher than 1%. The probe motion is similar to that in the well-known rolling sphere (ball) method. However, our system enables a steady and continuous measurement of viscosity, which is problematic using the conventional method. We also discuss the limits of the measurable viscosity range common to rolling-sphere-type viscometers by considering the accelerating motion of a probe sphere due to gravity, and we demonstrate the performance of our methods.
Electromagnetic scattering theory
Bird, J. F.; Farrell, R. A.
1986-01-01
Electromagnetic scattering theory is discussed with emphasis on the general stochastic variational principle (SVP) and its applications. The stochastic version of the Schwinger-type variational principle is presented, and explicit expressions for its integrals are considered. Results are summarized for scalar wave scattering from a classic rough-surface model and for vector wave scattering from a random dielectric-body model. Also considered are the selection of trial functions and the variational improvement of the Kirchhoff short-wave approximation appropriate to large size-parameters. Other applications of vector field theory discussed include a general vision theory and the analysis of hydromagnetism induced by ocean motion across the geomagnetic field. Levitational force-torque in the magnetic suspension of the disturbance compensation system (DISCOS), now deployed in NOVA satellites, is also analyzed using the developed theory.
Electromagnetically Clean Solar Arrays
Stem, Theodore G.; Kenniston, Anthony E.
2008-01-01
The term 'electromagnetically clean solar array' ('EMCSA') refers to a panel that contains a planar array of solar photovoltaic cells and that, in comparison with a functionally equivalent solar-array panel of a type heretofore used on spacecraft, (1) exhibits less electromagnetic interferences to and from other nearby electrical and electronic equipment and (2) can be manufactured at lower cost. The reduction of electromagnetic interferences is effected through a combination of (1) electrically conductive, electrically grounded shielding and (2) reduction of areas of current loops (in order to reduce magnetic moments). The reduction of cost is effected by designing the array to be fabricated as a more nearly unitary structure, using fewer components and fewer process steps. Although EMCSAs were conceived primarily for use on spacecraft they are also potentially advantageous for terrestrial applications in which there are requirements to limit electromagnetic interference. In a conventional solar panel of the type meant to be supplanted by an EMCSA panel, the wiring is normally located on the back side, separated from the cells, thereby giving rise to current loops having significant areas and, consequently, significant magnetic moments. Current-loop geometries are chosen in an effort to balance opposing magnetic moments to limit far-0field magnetic interactions, but the relatively large distances separating current loops makes full cancellation of magnetic fields problematic. The panel is assembled from bare photovoltaic cells by means of multiple sensitive process steps that contribute significantly to cost, especially if electomagnetic cleanliness is desired. The steps include applying a cover glass and electrical-interconnect-cell (CIC) sub-assemble, connecting the CIC subassemblies into strings of series-connected cells, laying down and adhesively bonding the strings onto a panel structure that has been made in a separate multi-step process, and mounting the
PANDA electromagnetic calorimeters
International Nuclear Information System (INIS)
Semenov, P.A.; Kharlov, Yu.V.; Uzunian, A.V.; Chernichenko, S.K.; Derevschikov, A.A.; Davidenko, A.M.; Goncharenko, Y.M.; Kachanov, V.A.; Konstantinov, A.S.; Kormilitsin, V.A.; Matulenko, Yu.A.; Meschanin, A.P.; Melnick, Y.M.; Minaev, N.G.; Mochalov, V.V.; Morozov, D.A.; Novotny, R.W.; Ryazantsev, A.A.; Soldatov, A.P.; Soloviev, L.F.
2009-01-01
PANDA is a challenging experimental setup to be implemented at the high-energy storage ring (HESR) at the international facility FAIR, GSI (Germany). PANDA physics program relies heavily on the capability to measure photons with excellent energy, position and timing resolution. For this purpose PANDA proposed to employ electromagnetic calorimeters using two different technologies: compact crystal calorimeter cooled to -25 deg. C around target and lead-scintillator sandwich calorimeter with optical fibers light collection (so-called shashlyk calorimeter) in the forward region. Institute for High Energy Physics (IHEP) PANDA group reports on two types of measurements performed at IHEP, Protvino: radiation hardness of the PWO crystals at -25 deg. C and testbeam studies of the energy and position resolution of the shashlyk calorimeter prototype in the energy range up to 19 GeV.
International Nuclear Information System (INIS)
Tirsky, V.V.; Ledenev, V.G.; Tomozov, V.M.
2001-01-01
We consider the process of generation of electromagnetic waves as a consequence of the merging of two Langmuir plasmons. The case of a hot plasma in a magnetic field is investigated. It is shown that under such conditions the frequency of Langmuir plasmons can vary over the range from 0.8 to 1.1 of the Langmuir frequency of electrons. The spectrum and polarization of electromagnetic radiation are analyzed. It is shown that allowance for the thermal motion of plasma particles under the conditions involved permits electromagnetic waves in the range from 1.6 to 2.2 of the Langmuir frequency of electrons to be generated. The degree of circular polarization of the radiation can reach 50% even in the case of an isotropic spectrum of Langmuir turbulence. (orig.)
Large Format Uncooled Focal Plane Array Project
National Aeronautics and Space Administration — Black Forest Engineering has identified innovative modifications in uncooled focal plane array (UFPA) architecture and processing that allows development of large...
Flux dynamics in ultrasensitive superconducting focal planes
National Aeronautics and Space Administration — The performance of superconducting focal planes will drive the achievable specifications of ultrasensitive instruments for NASA astrophysics missions, yet they have...
KEKB electromagnet power supply
Energy Technology Data Exchange (ETDEWEB)
Yoshida, Masato; Kubo, Tadashi [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)
2000-01-01
Numbers of electromagnet power supply for KEKB are 2,243 except BT. To satisfy stability, DAC in the current control circuit, current detector, R and D of small thermostatic bath and a calibration method of current using CPU were introduced. They satisfied needs. With producing R and D apparatus of switching source, problems of ripple, stability and noise were solved, so that we began mass production. In this paper, many kinds of R and D and performance and troubles after operation of KEKB power source are described. A plan of design of power supply consisted of seven items such as high accuracy, serial communication of interface, small type, high affectivity, easy maintenance, independence of current setting and current detector for monitor and control of radiation and conduction noise of switching power supply. These items were satisfied by development of interface board of ARCNET communication, introduction of double buffer method for interface through CPU, power supply unit by air-cooled method using a switching method and small thermostatic oven for bending and quadrupole electromagnet. R and D of DCCT, burden and shunt resistance, DAC, thermostatic bath, power supply, offset and gain calibration by double buffer method, specification of power supply, various kinds of measurements of mass production apparatus at rising, after long operation and problems before and after operation are reported. The results of R and D made satisfy the specification of stability and ripple of power supply. Although many switching power supply were operated, there was no noise and troubles at the initial period decreased. However, in order to use many power supply, the performance measurement and maintenance are very important at long shut down. (S.Y.)
Electromagnetic properties of neutrinos
Energy Technology Data Exchange (ETDEWEB)
Ould-Saada, F. [Zurich Univ. (Switzerland). Inst. fuer Physik
1996-11-01
Electromagnetic properties of neutrinos and their implications are discussed, and the experimental situation summarised. Spin precession in solar magnetic fields presents a solution of the solar neutrino problem. A magnetic moment, {mu}{sub {nu}}, of the order of 10{sup -11} {mu}{sub B} would be needed. In the simplest extension of the standard model, with no-vanishing neutrino masses, dipole moment interactions are allowed through higher order processes. A neutrino mass of {approx_equal}10 eV would give {mu}{sub {nu}}{approx_equal}10{sup -18} {mu}{sub B}, much smaller than the present experimental upper limit of 2x10{sup -10} {mu}{sub B}. Although model-dependent, upper bounds on dipole moments from astrophysics and cosmology are 10 to 100 times more stringent. Any values of {mu}{sub {nu}}, larger than the SM predictions, would then signal the onset of new physics. Among the processes sensitive to the magnetic moment, {nu}e{sup -} scattering presents two advantages: it is a pure weak, theoretically well understood process, and the recoil electron can be easily measured. A hypothetical electromagnetic contribution to the cross-section would dominate at low energies. A low background detector, MUNU, being built at the Bugey nuclear reactor is presented.It is based on a gas TPC, surrounded by a scintillator. The threshold on the electron recoil energy can be set very low, around 500 keV, giving the experiment a good sensitivity to the magnetic moment of the {nu}{sub e}, extending down to 2x10{sup -11} {mu}{sub B}. (author) 15 figs., 5 tabs., 96 refs.
Scatterfield microscopy using back focal plane imaging with an engineered illumination field
Patrick, Heather J.; Attota, Ravikiran; Barnes, Bryan M.; Germer, Thomas A.; Stocker, Michael T.; Silver, Richard M.; Bishop, Michael R.
2006-03-01
We have implemented back focal plane (conoscopic) imaging in an optical microscope that has also been modified to allow selection of the illumination angles and polarization at the sample, and collected back focal plane images of silicon on silicon grating scatterometry targets with varying line widths. Using a slit illumination mask, the zero-order diffraction versus angle for -60° to +60° incident angles at a given polarization was obtained from a single image. By using reference images taken on a flat silicon background, we correct the raw target images for illumination source inhomogeneities and polarization-dependent transmission of the optics, and convert them to reflectance versus angle data for s- and p-polarizations, similar to that obtained from angle-resolved grating scatterometry. As with conventional scatterometry, the target lines need not be resolved for the reflectance signature to show sensitivity to small changes in the grating parameters. For a series of 300 nm pitch targets with line widths from 150 nm to 157 nm, we demonstrate nanometer-level sensitivity to line width with good repeatability, using 546 nm illumination. Additionally, we demonstrate a technique for separating the zero order from higher order diffraction on targets with multiple diffraction orders, allowing collection of both zero and higher order diffraction versus angle from the back focal plane image. As conventional images can be easily collected on the same microscope, the method provides a powerful tool for combining imaging metrology with scatterometry for optical critical dimension measurements in semiconductors.
Highly Anisotropic in-Plane Excitons in Atomically Thin and Bulklike 1T '-ReSe_{2}
DEFF Research Database (Denmark)
Arora, Ashish; Noky, Jonathan; Drueppel, Matthias
2017-01-01
Atomically thin materials such as graphene or MoS2 are of high in-plane symmetry. Crystals with reduced symmetry hold the promise for novel optoelectronic devices based on their anisotropy in current flow or light polarization. Here, we present polarization-resolved optical transmission and photo...
Directory of Open Access Journals (Sweden)
H.-P. Geromiller
2004-01-01
Full Text Available The influence of electromagnetic radiation from mobile antennas on humans is under discussion in various group of scientists. This paper deals with the impact of electromagnetic radiation in housing spaces. The space is assumed to be bordered by 5 walls of ferroconcrete and a door-window combination on the 6th side, the latter to be electromagnetic transparent. The transparent side of the housing is exposed to an electromagnetic wave. As the source of radiation is considered to be far away from the housing, the radiation is regarded as a plane wave. Due to the high signal frequency and the ferroconcrete walls, 5 sides of the housing space are considered to be perfect conductors. The electric field inside the housing is calculated numerically by the method of finite differences for different angles of incidence of the radiated electromagnetic wave. The maximum value of the calculated electric field is outlined in a diagram.
Spacetime algebra as a powerful tool for electromagnetism
Energy Technology Data Exchange (ETDEWEB)
Dressel, Justin, E-mail: prof.justin.dressel@gmail.com [Department of Electrical and Computer Engineering, University of California, Riverside, CA 92521 (United States); Center for Emergent Matter Science (CEMS), RIKEN, Wako-shi, Saitama, 351-0198 (Japan); Bliokh, Konstantin Y. [Center for Emergent Matter Science (CEMS), RIKEN, Wako-shi, Saitama, 351-0198 (Japan); Interdisciplinary Theoretical Science Research Group (iTHES), RIKEN, Wako-shi, Saitama, 351-0198 (Japan); Nori, Franco [Center for Emergent Matter Science (CEMS), RIKEN, Wako-shi, Saitama, 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, MI 48109-1040 (United States)
2015-08-08
We present a comprehensive introduction to spacetime algebra that emphasizes its practicality and power as a tool for the study of electromagnetism. We carefully develop this natural (Clifford) algebra of the Minkowski spacetime geometry, with a particular focus on its intrinsic (and often overlooked) complex structure. Notably, the scalar imaginary that appears throughout the electromagnetic theory properly corresponds to the unit 4-volume of spacetime itself, and thus has physical meaning. The electric and magnetic fields are combined into a single complex and frame-independent bivector field, which generalizes the Riemann–Silberstein complex vector that has recently resurfaced in studies of the single photon wavefunction. The complex structure of spacetime also underpins the emergence of electromagnetic waves, circular polarizations, the normal variables for canonical quantization, the distinction between electric and magnetic charge, complex spinor representations of Lorentz transformations, and the dual (electric–magnetic field exchange) symmetry that produces helicity conservation in vacuum fields. This latter symmetry manifests as an arbitrary global phase of the complex field, motivating the use of a complex vector potential, along with an associated transverse and gauge-invariant bivector potential, as well as complex (bivector and scalar) Hertz potentials. Our detailed treatment aims to encourage the use of spacetime algebra as a readily available and mature extension to existing vector calculus and tensor methods that can greatly simplify the analysis of fundamentally relativistic objects like the electromagnetic field.
Fermi liquid of two-dimensional polar molecules
Lu, Z.K; Shlyapnikov, G.V.
2012-01-01
We study Fermi-liquid properties of a weakly interacting two-dimensional gas of single-component fermionic polar molecules with dipole moments d oriented perpendicularly to the plane of their translational motion. This geometry allows the minimization of inelastic losses due to chemical reactions
Electromagnetic Cylindrical Transparent Devices with Irregular Cross Section
Directory of Open Access Journals (Sweden)
C. Yang
2010-04-01
Full Text Available Electromagnetic transparent device is very important for antenna protection. In this paper, the material parameters for the cylindrical transparent devices with arbitrary cross section are developed based on the coordinate transformation. The equivalent two-dimensional (2D transparent devices under TE plane and cylindrical wave irradiation is designed and studied by full-wave simulation, respectively. It shows that although the incident waves are distorted in the transformation region apparently, they return to the original wavefronts when passing through the device. All theoretical and numerical results validate the material parameters for the cylindrical transparent devices with arbitrary cross section we developed.
International Nuclear Information System (INIS)
Chiang, C.H.; Chen, K.M.; Wu, Y.H.; Yeh, Y.S.; Lee, W.I.; Chen, J.F.; Lin, K.L.; Hsiao, Y.L.; Huang, W.C.; Chang, E.Y.
2011-01-01
Mirror-like and pit-free non-polar a-plane (1 1 -2 0) GaN films are grown on r-plane (1 -1 0 2) sapphire substrates using metalorganic chemical vapor deposition (MOCVD) with multilayer high-low-high temperature AlN buffer layers. The buffer layer structure and film quality are essential to the growth of a flat, crack-free and pit-free a-plane GaN film. The multilayer AlN buffer structure includes a thin low-temperature-deposited AlN (LT-AlN) layer inserted into the high-temperature-deposited AlN (HT-AlN) layer. The results demonstrate that the multilayer AlN buffer structure can improve the surface morphology of the upper a-plane GaN film. The grown multilayer AlN buffer structure reduced the tensile stress on the AlN buffer layers and increased the compressive stress on the a-plane GaN film. The multilayer AlN buffer structure markedly improves the surface morphology of the a-plane GaN film, as revealed by scanning electron microscopy. The effects of various growth V/III ratios was investigated to obtain a-plane GaN films with better surface morphology. The mean roughness of the surface was 1.02 nm, as revealed by atomic force microscopy. Accordingly, the multilayer AlN buffer structure improves the surface morphology and facilitates the complete coalescence of the a-plane GaN layer.
Consideration of R2Fe14B layers as targets with polarized electrons
Hoogduin, JM; van Klinken, J
Thin layers of R2Fe14B magnets (R = rare earth) can be magnetized perpendicularly to their planes and can be used as targets of polarized electrons with polarization of approximate to 4% to facilitate Moller/Bhabha and Compton polarimetry of electrons/positrons and photons, respectively. (C) 1998
Zeddam, Ahmed; Avril, Gautier; Tlich, Mohamed
2009-01-01
This article deals with the electromagnetic environment management problem within the context of high speed digital transmissions deployed in wired telecommunication networks. Traditionally, Electromagnetic Compatibility (EMC) is assured by filtering for better electromagnetic immunity, and by cable shielding for emission limitation. However, like cognitive radio, we can also, for high speed wired transmissions, treat the EMC as an intelligent and autonomous system capable of perceiving its environment, interpreting it, making suited decisions, and reacting according to the constraints related to the electromagnetic environment. In this context, some application examples are here given in order to illustrate this evolution towards a cognitive EMC in wired networks. To cite this article: A. Zeddam et al., C. R. Physique 10 (2009).