Behavior Of Electromagnetic Field Research Articles

Photonic Eigenmodes in a Photonic Crystal Membrane

Photonic membranes are the most widely used kind of 2D photonic crystals in signal processing. Nevertheless, some important aspects of electromagnetic field behavior in membrane like photonic crystals (MPCs) need detail investigation. We develop the approach close to resonant coupling modes method which unites both external and intrinsic problems, in-plane and out-of-plane geometries, and resonator properties of MPC. The resonator standing modes are excited by an external source through the special inputs and may be controlled due to the nonlinear coating. Typical photonic manifestations are studied for Si/SiO2 2D membrane resonators of rectangular.

Rigorous analysis of the parallel plate waveguide: From the transverse electromagnetic mode to the surface plasmon polariton

This paper presents an analysis of the parallel plate waveguide, based on a hybrid mode formulation. The nonideal metallic conductors of the waveguide are treated as a media characterized by an equivalent permittivity. The frequencies of interest in the presented analysis are at the terahertz band (from 300 GHz to 30 THz), and appropriate models are used for the correct characterization of metallic conductors at these frequencies. The behavior of the electromagnetic field of the fundamental mode is studied in a wide frequency range. At low frequencies (microwave regime) the fundamental mode is the well‐known transverse electromagnetic (TEM) mode; as frequency increases, the electromagnetic field changes significantly and a surface wave or surface plasmon polariton (SPP) behavior is observed at the highest frequencies of the terahertz band. This paper shows a unified formulation that explains this transformation in the electromagnetic field behavior.

Behavior of evanescent fields in the periodic scattering system

We study the problem of scattering by a thin and conducting screen perforated periodically with square apertures, when the screen is illuminated by an electromagnetic wave in subwavelength regime. Our formulation extends the monomodal approximation technique up to the second-order Floquet modes, which enable us to investigate not only propagation mode, but also nonpropagation mode in the low-frequency regime. We also study dispersion relation of the principal Floquet modes and show the behavior of electromagnetic fields in the periodic system at the extremely low frequency, the resonance frequency and Wood’s anomaly frequency. The interesting characteristics of the fields can be found in these specific frequencies.

Modeling of Antenna for Deep Target Hydrocarbon Exploration

Nowadays control source electromagnetic method is used for offshore hydrocarbon exploration. Hydrocarbon detection in sea bed logging (SBL) is a very challenging task for deep target hydrocarbon reservoir. Response of electromagnetic (EM) field from marine environment is very low and it is very difficult to predict deep target reservoir below 2 km from the sea floor. This work premise deals with modeling of new antenna for deep water deep target hydrocarbon exploration. Conventional and new EM antennas at 0.125 Hz frequency are used in modeling for the detection of deep target hydrocarbon reservoir. The proposed area of the seabed model (40 km ′ 40 km) was simulated by using CST (computer simulation technology) EM studio based on Finite Integration Method (FIM). Electromagnetic field components were compared at 500 m target depth and it was concluded that Ex and Hz components shows better resistivity contrast. Comparison of conventional and new antenna for different target depths was done in our proposed model. From the results, it was observed that conventional antenna at 0.125 Hz shows 70%, 86% resistivity contrast at target depth of 1000 m where as new antenna showed 329%, 355% resistivity contrast at the same target depth for Ex and Hz field respectively. It was also investigated that at frequency of 0.125 Hz, new antenna gave 46% better delineation of hydrocarbon at 4000 m target depth. This is due to focusing of electromagnetic waves by using new antenna. New antenna design gave 125% more extra depth than straight antenna for deep target hydrocarbon detection. Numerical modeling for straight and new antenna was also done to know general equation for electromagnetic field behavior with target depth. From this numerical model it was speculated that this new antenna can detect up to 4.5 km target depth. This new EM antenna may open new frontiers for oil and gas industry for the detection of deep target hydrocarbon reservoir (HC).

THE DARK MAGNETISM OF THE UNIVERSE

Despite the success of Maxwell's electromagnetism in the description of the electromagnetic interactions on small scales, we know very little about the behavior of electromagnetic fields on cosmological distances. Thus, it has been suggested recently that the problems of dark energy and the origin of cosmic magnetic fields could be pointing to a modification of Maxwell's theory on large scales. Here, we review such a proposal in which the scalar state which is usually eliminated by means of the Lorenz condition is allowed to propagate. On super-Hubble scales, the new mode is essentially given by the temporal component of the electromagnetic potential and contributes as an effective cosmological constant to the energy–momentum tensor. The new state can be generated from quantum fluctuations during inflation and it is shown that the predicted value for the cosmological constant agrees with observations, provided inflation took place at the electroweak scale. We also consider more general theories including non-minimal couplings to the spacetime curvature in the presence of the temporal electromagnetic background. We show that both in the minimal and non-minimal cases, the modified Maxwell's equations include new effective current terms which can generate magnetic fields from sub-galactic scales up to the present Hubble horizon. The corresponding amplitudes could be enough to seed a galactic dynamo or even to account for observations just by collapse and differential rotation in the protogalactic cloud.

Simulation and Physical Character Analysis of the Operation Process of POS

Particle-in-cell simulation method is used to integrally study the operation process of a low-density plasma opening switch (POS) with or without external applied magnetic field. The experiment has successfully simulated the space-time variety of electromagnetic field and kinetic behavior of electrons in the POS. The phenomena that happened in the operation process of POS, such as magnetic field penetration, magnetic insulation, irregular movement of nonuniformity particles, and aberrance of the field in electromagnetohydrodynamic operation process, were analyzed to investigate the open process of POS based on the characters of electromagnetic field. The analysis results proved that angle magnetic field which had the same direction with the drive current magnetic field can improve the performance of the POS. The conclusion of this paper provides a general solution method to optimize the configurable parameters and the controllable movement of plasma.

Circuit modeling of multiband high-impedance surface absorbers in the microwave regime

In this paper, we present a simple circuit model to study the absorption of electromagnetic waves by a multilayer structure with a high impedance surface in the microwave regime. The absorber consists of a stack of two-dimensional arrays of sub-wavelength meshes or patches separated by dielectric slabs and backed by a metallic ground plane, with a single resistive sheet placed on the top layer. We observe the appearance of low-frequency resonances of total absorption, which have been identified as the resonances of Fabry-P\'erot type associated with the individual reactively loaded dielectric slabs (that are strongly coupled through the subwavelength grids). It is shown that these resonances lie within certain characteristic frequency band defined by the structural parameters of the absorber. The observed resonances are characterized by studying the electromagnetic field behavior using the circuit model and full-wave numerical program. In addition, we show that the patch array absorber provides stable resonances with respect to the angle and the polarization of obliquely incident plane waves.

Exact solutions for the source-excited cylindrical electromagnetic waves in a nonlinear nondispersive medium

The behavior of electromagnetic fields in nonlinear media has been a topical problem since the discovery of materials with a nonlinearity of electromagnetic properties. The problem of finding exact solutions for the source-excited nonlinear waves in curvilinear coordinates has been regarded as unsolvable for a long time. In this work, we present the first solution of this type for a cylindrically symmetric field excited by a pulsed current filament in a nondispersive medium that is simultaneously inhomogeneous and nonlinear. Assuming that the medium has a power-law permittivity profile in the linear regime and lacks a center of inversion, we derive an exact solution for the electromagnetic field excited by a current filament in such a medium and discuss the properties of this solution.

Creation of high resolution pattern by nanoscratching

Abstract The lithography is a basic microelectronic process which determines properties of fabricated device. The resolution of optical lithography applied nowadays is insufficient for creating high resolution patterns such as gate electrode in transistors. The scaling ability is the major motivation for undertaking experiments to elaborate high resolution lithography techniques. The atomic force microscope (AFM) is commonly used as tool for creation patterns in sub-micrometers resolution. In this paper, the results of simulations of electromagnetic field behavior during passing the gap with a size smaller than the wavelength of the optical lithography light source are presented. Also results of the nanoscratching lithography prepared for various parameters of force that are applied to the tip are summarized.

Experimental Study of Electromagnetic Environment in the Vicinity of High Voltage Lines

Problem statement: Several studies have investigated the impact of electromagnetic field generated by high voltage power lines on environment. The evaluation of electric and magnetic field quantities are of paramount interest in the characterization of electromagnetic environment of the proposed line. The purpose of this study was to analyze the behavior of electromagnetic fields generated by power lines in an area of strong population. Approach: The method applied in this study was gradual; examined the effects of different couplings between the different neighboring lines on behavior of electric and magnetic fields. Later, these lines will be used as a source of disturbance applied to the auditory implants EMC. Results: The implications of experimental results were also compared and discussed with new standard. Conclusion: The maximum intensities of electric and magnetic fields measured for the circuit of three lines close to each other, within the El-HADJAR substation were significantly lower than the ICNIRP reference levels for occupational and no occupational exposures.

Concave hyperlens for directed sub-wavelength demagnification imaging

A novel demagnification imaging device named concave hyperlens has been designed withmetal–dielectric alternating thin layers. Its upper portion is a planar multilayer and thelower portion takes a confocal ellipse shape. Our concave hyperlens has two planarsurfaces and can realize demagnification imaging beyond the diffraction limit inreal time. The transfer matrix method (TMM) is for the first time introduced toanalyze the electromagnetic field behavior through an ellipse structure and asemi-analytic resolution is derived in the form of a Mathieu function. Numericalsimulations are given to verify our scheme and demonstrate its capabilities ofshrinking imaging. Such a directed demagnification imaging device is easy toengineer and convenient for nanoscale manufacture and optical data storage.

Singular behavior of the multipole electromagnetic field

The singularities of the electromagnetic field are derived to include all the pointlike multipoles representing an electric charge and current distribution. In the static case, the δ-singularities are expressed for arbitrary multipole orders, while in the dynamic case we restrict ourselves to the lower orders. The algorithm we give can be easily extended to the next orders. In both cases, we show that for higher orders, it is more efficient to have fields represented in terms of symmetric and trace-free moments.

A Domain Decomposition Approach for Efficient Electromagnetic Analysis of the Power Distribution Network of Packaged Electronic Systems

A versatile electromagnetic modeling methodology is presented that is most suitable for use in the computer-aided design of the power distribution network (PDN) of packaged electronics. The method is characterized by modeling flexibility and computational efficiency. These attributes stem from the adoption of a modular approach for the development of the model, where the fine-feature, geometric discontinuities in the network, such as pins, vias, and splits in metallization layers, are modeled separately from the solid planar ground and power metallization portions. In this manner, multiport network models of these discontinuities are developed, making possible their expedient insertion in a discrete electromagnetic model for the solid portions of the metallization. The latter is based on a 2-D integral equation model for the cylindrical transverse electromagnetic field behavior between the metallization planes, for which only electrically important features are preserved and modeled. The utilization of a systematic decomposition approach further enhances the modeling versatility of the proposed method and enables the development of a modeling methodology that is suitable for computer-aided iteration in the electromagnetic performance-aware design of multilayer PDNs. Validation studies are used to demonstrate the efficiency of the proposed methodology and assess its accuracy as a computer-aided tool for PDN predesign.

Understanding possible electromagnetic counterparts to loud gravitational wave events: Binary black hole effects on electromagnetic fields

In addition to producing loud gravitational waves, the dynamics of a binary black hole system could induce emission of electromagnetic radiation by affecting the behavior of plasmas and electromagnetic fields in their vicinity. We study how the electromagnetic fields are affected by a pair of orbiting black holes through the merger. In particular, we show how the binary's dynamics induce a variability in possible electromagnetically induced emissions as well as an enhancement of electromagnetic fields during the late-merge and merger epochs. These time dependent features will likely leave their imprint in processes generating detectable emissions and can be exploited in the detection of electromagnetic counterparts of gravitational waves.

Oxygen dependency of the hydrogen sensor based on high-temperature proton conductors

Oxygen dependency of the hydrogen sensor using high-temperature proton conductors with titanium/titanium hydride solid reference material was studied. It was found that the oxygen in a measuring atmosphere led to a considerable p-type conduction which was responsible for the instability of the sensor electromagnetic field (EMF). The sensor EMF increased continuously due to the insertion of protons and decreased due to the depletion of protons upon exposure to an oxidizing atmosphere. It is revealed that the EMF behavior of the sensor is decided by the electronic conduction that relatively changed with hydrogen concentration in a highly oxidizing atmosphere. The transient behavior of the hydrogen sensor under various atmospheres containing oxygen was discussed in this work.

Definition and invariance properties of the complex degree of spatial coherence

Within the framework of the phase-space representation of random electromagnetic fields provided by electromagnetic spatial coherence wavelets, and by using the Fresnel-Arago laws for interference and polarization as an analysis tool, the meaning of the spatial coherence-polarization tensor and its invariance under transformations is studied. The results give new insight into the definition and properties of the complex degree of spatial coherence by showing that its invariance is not required for properly describing the behavior of random electromagnetic fields within the scope of physically measurable quantities.

Binary Black Holes’ Effects on Electromagnetic Fields

In addition to producing gravitational waves, the dynamics of a binary black hole system could induce emission of electromagnetic radiation by affecting the behavior of plasmas and electromagnetic fields in their vicinity. We here study how the electromagnetic fields are affected by a pair of orbiting black holes through the merger. In particular, we show how the binary's dynamics induce a variability in possible electromagnetically induced emissions as well as a possible enhancement of electromagnetic fields during the late-merge and merger epochs. These time dependent features will likely leave their imprint in processes generating detectable emissions and can be exploited in the detection of electromagnetic counterparts of gravitational waves.

Radiation generated by accelerating and rotating charged black holes in (anti-)de Sitter space

Asymptotic behaviour of gravitational and electromagnetic fields of exact type D solutions from the large Plebański–Demiański family of black hole spacetimes is analysed. The amplitude and directional structure of radiation is evaluated in cases when the cosmological constant is non-vanishing, so that the conformal infinities have either de Sitter-like or anti-de Sitter-like character. In particular, explicit relations between the parameters that characterize the sources (that is their mass, electric and magnetic charges, NUT parameter, rotational parameter and acceleration) and properties of the radiation generated by them are presented. The results further elucidate the physical interpretation of these solutions and may help to understand radiative characteristics of more general spacetimes than those that are asymptotically flat.

海洋ＣＳＥＭ法による油ガス層分布の把握技術の現状とその可能性

Recently the marine controlled-source electromagnetics (CSEM) is applied commercially to the problem of detecting the presence of hydrocarbon filled layers in the sub-sea formations, and a number of companies are now providing this service.In this paper, we return to fundamentals of electromagnetic (EM) method. Transmission frequencies used in the marine CSEM are typically between 0.01 and 10Hz. As such low frequencies, the behavior of EM field in subsurface is governed by the diffusion equation rather than the wave equation. The EM field radiated by an electric source can be considered to consist of two different modes : a TM mode component and a TE mode component. An analysis of both the TE and TM mode holds the potential to determine if the increase in the measured EM field is caused by the presence of hydrocarbon saturated reservoir or other resistive bodies in the subsurface. The physics of CSEM in shallow water is also examined by using simple 1-D models. This would show that the concept of air interaction, rather than air wave, is appropriate because of complex coupling between signals interacting with seafloor and air.We then apply the inversion analysis to frequency-domain CSEM sounding data acquired in the offshore of Australia, investigate how the marine CSEM could reconstruct resistivity image of gas bearing formation. The survey area comprises two towed lines, covering discovered gas field. The transmitter antenna is a horizontal electric dipole of length about 250m, towing along profiles at an average of 30m above the receivers. For the inversion process, we use a starting model with homogeneous background of 1.0 ohm-m below the sea bottom. No further a priori information is utilized during the inversion. The inversion reaches acceptable data misfit, produced images of the resistive target which can be interpreted gas bearing formation.

Wireless transmission monitoring in a geological disposal repository (II) Research and Development

AbstractThe development of the wireless transmission monitoring in the geological disposal repository, the underground laboratories, the test facilities and the demonstration area, will present an opportunity to provide greater flexibility and robustness to the confirmation of the barrier performance and therefore safety of repository [1]. So as to realize the wireless transmission monitoring especially in the betonite barrier, RWMC has been researching and developing the wireless data transmission system which uses the very low frequency (VLF: around 1 kHz) electromagnetic wave. In this system, transmitting and receiving is conducted through loop coil antennas. The overall transmission system is digitized and maximum 19 sensors can be connected to one transmitter. Transmission distance can be selected from several meters to several hundred meters.This paper firstly presents the behavior of VLF electromagnetic wave propagation in the rock mass and the underground facility revealed by the in-situ transmission experiment and the analytical method evaluating the behavior of the VLF electromagnetic field in various environments. Development results of the transmitting antenna and the improvement of the transmission performance are secondly shown. The technical feasibility and the future R&D plan of the wireless monitoring in the repository are also explained.