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1

Method for imaging with low frequency electromagnetic fields  

DOE Patents [OSTI]

A method is described for imaging with low frequency electromagnetic fields, and for interpreting the electromagnetic data using ray tomography, in order to determine the earth conductivity with high accuracy and resolution. The imaging method includes the steps of placing one or more transmitters, at various positions in a plurality of transmitter holes, and placing a plurality of receivers in a plurality of receiver holes. The transmitters generate electromagnetic signals which diffuse through a medium, such as earth, toward the receivers. The measured diffusion field data H is then transformed into wavefield data U. The travel times corresponding to the wavefield data U, are then obtained, by charting the wavefield data U, using a different regularization parameter [alpha] for each transform. The desired property of the medium, such as conductivity, is then derived from the velocity, which in turn is constructed from the wavefield data U using ray tomography. 13 figures.

Lee, K.H.; Xie, G.Q.

1994-12-13T23:59:59.000Z

2

Method for imaging with low frequency electromagnetic fields  

DOE Patents [OSTI]

A method for imaging with low frequency electromagnetic fields, and for interpreting the electromagnetic data using ray tomography, in order to determine the earth conductivity with high accuracy and resolution. The imaging method includes the steps of placing one or more transmitters, at various positions in a plurality of transmitter holes, and placing a plurality of receivers in a plurality of receiver holes. The transmitters generate electromagnetic signals which diffuse through a medium, such as earth, toward the receivers. The measured diffusion field data H is then transformed into wavefield data U. The traveltimes corresponding to the wavefield data U, are then obtained, by charting the wavefield data U, using a different regularization parameter .alpha. for each transform. The desired property of the medium, such as conductivity, is then derived from the velocity, which in turn is constructed from the wavefield data U using ray tomography.

Lee, Ki H. (Lafayette, CA); Xie, Gan Q. (Berkeley, CA)

1994-01-01T23:59:59.000Z

3

Low-frequency electromagnetic field in a Wigner crystal  

SciTech Connect (OSTI)

Long-wave low-frequency oscillations are described in a Wigner crystal by generalization of the reverse continuum model for the case of electronic lattice. The internal self-consistent long-wave electromagnetic field is used to describe the collective motions in the system. The eigenvectors and eigenvalues of the obtained system of equations are derived. The velocities of longitudinal and transversal sound waves are found.

Stupka, Anton [Oles Honchar Dnipropetrovs'k National University, Gagarin Ave., 72, 49010 Dnipropetrovs'k (Ukraine)

2013-03-15T23:59:59.000Z

4

Calcium homeostasis of isolated heart muscle cells exposed to pulsed high-frequency electromagnetic fields  

SciTech Connect (OSTI)

The intracellular calcium concentration ([Ca{sup 2+}]{sub i}) of isolated ventricular cardiac myocytes of the guinea pig was measured during the application of pulsed high-frequency electromagnetic fields. The high-frequency fields were applied in a transverse electromagnetic cell designed to allow microscopic observation of the myocytes during the presence of the high-frequency fields. The [Ca{sup 2+}]{sub i} was measured as fura-2 fluorescence by means of digital image analysis. Both the carrier frequency and the square-wave pulse-modulation pattern were varied during the experiments (carrier frequencies: 900, 1,300, and 1,800 MHz pulse modulated at 217 Hz with 14% duty cycle; pulsation pattern at 900 MHz; continuous wave, 16 Hz,and 50 Hz modulation with 50% duty cycle and 30 kHz modulation with 80% duty cycle). The mean specific absorption rate (SAR) values in the solution were within one order of magnitude of 1 mW/kg. They varied depending on the applied carrier frequency and pulse pattern. The experiments were designed in three phases: 500 s of sham exposure, followed by 500 s of field exposure, then chemical stimulation without field. The chemical stimulation (K{sup +}-depolarization) indicated the viability of the cells. The K{sup +} depolarization yielded a significant increase in [Ca{sup 2+}]{sub i}. Significant differences between sham exposure and high-frequency field exposure were not found except when a very small but statistically significant difference was detected in the case of 900 MHz/50 Hz. However, this small difference was not regarded as a relevant effect of the exposure.

Wolke, S.; Gollnick, F.; Meyer, R. [Univ. Bonn (Germany)] [Univ. Bonn (Germany); Neibig, U.; Elsner, R. [Inst. fuer Nachrichtentechnik Braunschweig (Germany)] [Inst. fuer Nachrichtentechnik Braunschweig (Germany)

1996-05-01T23:59:59.000Z

5

Determination of High-Frequency Current Distribution Using EMTP-Based Transmission Line Models with Resulting Radiated Electromagnetic Fields  

SciTech Connect (OSTI)

Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.

Mork, B; Nelson, R; Kirkendall, B; Stenvig, N

2009-11-30T23:59:59.000Z

6

Electromagnetic Field Theory  

E-Print Network [OSTI]

Electromagnetic Field Theory BO THID� UPSILON BOOKS #12;#12;ELECTROMAGNETIC FIELD THEORY #12;#12;Electromagnetic Field Theory BO THID� Swedish Institute of Space Physics and Department of Astronomy and Space, Sweden UPSILON BOOKS · COMMUNA AB · UPPSALA · SWEDEN #12;Also available ELECTROMAGNETIC FIELD THEORY

Hart, Gus

7

Theory of electromagnetic fields  

E-Print Network [OSTI]

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.

Wolski, Andrzej

2011-01-01T23:59:59.000Z

8

Coherent hybrid electromagnetic field imaging  

DOE Patents [OSTI]

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.

Cooke, Bradly J. (Jemez Springs, NM); Guenther, David C. (Los Alamos, NM)

2008-08-26T23:59:59.000Z

9

Occupational and residential 60-Hz electromagnetic fields and high-frequency electric transients: exposure assessment using a new dosimeter  

SciTech Connect (OSTI)

One problem that has limited past epidemiologic studies of cancer and exposure to extremely low-frequency (0-100 Hz) electric and magnetic fields has been the lack of adequate methods for assessing personal exposure to these fields. A new 60-Hz electromagnetic field dosimeter was tested to assess occupational and residential exposures of a group of electrical utility workers and a comparison background group over a 7-day period. Comparing work periods only, utility workers' exposures were significantly higher than background levels by a factor of about 10 for electric (E) and magnetic (B) fields and by a factor of 171 for high-frequency transient electric (HFTE) fields. When overall weekly time-weighted averages combining work and nonwork exposures were compared, ratios of the exposed to background groups were lower. B and HFTE exposure ratios remained statistically significant, with values of 3.5 and 58, respectively, whereas the electric field exposure ratio was no longer significant, with a value of 1.7. E-field exposures of the background group were the highest during the nonwork period, probably reflecting the use of electrical appliances at home. Residential E- and B-field exposures were in the same range as published results from other surveys, whereas occupational E-field exposures tended to be lower than exposures reported in other studies. The high variability associated with occupational exposures probably accounts for the latter discrepancy. Worker acceptance of wearing the dosimeter was good: 95% of participants found it to be of little or no inconvenience while at work. At home, 37% found the device to be inconvenient in its present form but would not object to wearing a slightly smaller and lighter dosimeter.

Deadman, J.E.; Camus, M.; Armstrong, B.G.; Heroux, P.; Cyr, D.; Plante, M.; Theriault, G.

1988-08-01T23:59:59.000Z

10

Torsion and the Electromagnetic Field  

E-Print Network [OSTI]

In the framework of the teleparallel equivalent of general relativity, we study the dynamics of a gravitationally coupled electromagnetic field. It is shown that the electromagnetic field is able not only to couple to torsion, but also, through its energy-momentum tensor, to produce torsion. Furthermore, it is shown that the coupling of the electromagnetic field with torsion preserves the local gauge invariance of Maxwell's theory.

V. C. de Andrade; J. G. Pereira

1999-01-11T23:59:59.000Z

11

Electromagnetic field and cosmic censorship  

E-Print Network [OSTI]

We construct a gedanken experiment in which an extremal Kerr black hole interacts with a test electromagnetic field. Using Teukolsky's solutions for electromagnetic perturbations in Kerr spacetime, and the conservation laws imposed by the energy momentum tensor of the electromagnetic field and the Killing vectors of the spacetime, we prove that this interaction cannot convert the black hole into a naked singularity, thus cosmic censorship conjecture is not violated in this case.

Koray Düzta?

2014-04-09T23:59:59.000Z

12

IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 58, NO. 1, JANUARY 2009 129 Very-Low-Frequency Electromagnetic Field  

E-Print Network [OSTI]

, Walter J. Varhue, and Stephen Titcomb, Senior Member, IEEE Abstract--Naturally occurring electromagnetic and difficult to detect under normal conditions. These naturally occurring VLF electromagnetic events. This electronic system can be used to monitor VLF electromagnetic radiation in residential and occupational

Motai, Yuichi

13

Electromagnetic source localization with finite set of frequency measurements  

E-Print Network [OSTI]

A phase conjugation algorithm for localizing an extended radiating electromagnetic source from boundary measurements of the electric field is presented. Measurements are taken over a finite number of frequencies. The artifacts related to the finite frequency data are tackled with $l_1-$regularization blended with the fast iterative shrinkage-thresholding algorithm with backtracking of Beck & Teboulle.

Abdul Wahab; Amer Rasheed; Rab Nawaz; Saman Anjum

2014-09-16T23:59:59.000Z

14

Narrow field electromagnetic sensor system and method  

DOE Patents [OSTI]

A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor system also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments.

McEwan, Thomas E. (Livermore, CA)

1996-01-01T23:59:59.000Z

15

STIMULATED ELECTROMAGNETIC EMISSIONS BY HIGH-FREQUENCY ELECTROMAGNETIC PUMPING OF THE  

E-Print Network [OSTI]

STIMULATED ELECTROMAGNETIC EMISSIONS BY HIGH-FREQUENCY ELECTROMAGNETIC PUMPING OF THE IONOSPHERIC.S.A. Abstract. A high frequency electromagnetic pump wave transmitted into the ionospheric plasma from the ground can stimulate electromagnetic radiation with frequencies around that of the ionospher- ically

16

Electromagnetic-gravitational cross-sections in external electromagnetic fields  

E-Print Network [OSTI]

The classical processes: the conversion of photons into gravitons in the static electromagnetic fields are considered by using Feynman perturbation techniques. The differential cross sections are presented for the conversion in the electric field of the flat condesor and the magnetic field of the selenoid. A numerical evaluation shows that the cross sections may have the observable value in the present technical scenario.

Long, H N; Tran, T A; Tuan, T A; Long, Hoang Ngoc; Van Soa, Dang; Tran, Tuan A; Tuan, Tran Anh

1994-01-01T23:59:59.000Z

17

Electromagnetic field with constraints and Papapetrou equation  

E-Print Network [OSTI]

It is shown that geometric optical description of electromagnetic wave with account of its polarization in curved space-time can be obtained straightforwardly from the classical variational principle for electromagnetic field. For this end the entire functional space of electromagnetic fields must be reduced to its subspace of locally plane monochromatic waves. We have formulated the constraints under which the entire functional space of electromagnetic fields reduces to its subspace of locally plane monochromatic waves. These constraints introduce variables of another kind which specify a field of local frames associated to the wave and contain some congruence of null-curves. The Lagrangian for constrained electromagnetic field contains variables of two kinds, namely, a congruence of null-curves and the field itself. This yields two kinds of Euler-Lagrange equations. Equations of first kind are trivial due to the constraints imposed. Variation of the curves yields the Papapetrou equations for a classical massless particle with helicity 1.

Z. Ya. Turakulov; A. T. Muminov

2006-01-12T23:59:59.000Z

18

Noninvasive valve monitor using alternating electromagnetic field  

DOE Patents [OSTI]

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.

Eissenberg, David M. (Oak Ridge, TN); Haynes, Howard D. (Knoxville, TN); Casada, Donald A. (Knoxville, TN)

1993-01-01T23:59:59.000Z

19

Resonant circuit which provides dual-frequency excitation for rapid cycling of an electromagnet  

DOE Patents [OSTI]

Disclosed is a novel ring-magnet control circuit that permits synchrotron repetition rates much higher than the frequency of the sinusoidal guide field of the ring magnet during particle acceleration. The control circuit generates sinusoidal excitation currents of different frequencies in the half waves. During radio-frequency acceleration of the synchrotron, the control circuit operates with a lower frequency sine wave and, thereafter, the electromagnets are reset with a higher-frequency half sine wave.

Praeg, W.F.

1982-03-09T23:59:59.000Z

20

Scattering by an electromagnetic radiation field  

E-Print Network [OSTI]

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 electromagnetic wave, i.e., scalar (spin 0), massless spin $\\frac12$ and electromagnetic (spin 1) fields, is studied too.

Donato Bini; Andrea Geralico

2014-08-21T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Simulation and Modeling Techniques for Signal Integrity and Electromagnetic Interference on High Frequency Electronic Systems.  

E-Print Network [OSTI]

Simulation and Modeling Techniques for Signal Integrity and Electromagnetic Interference on High and Modeling Techniques for Signal Integrity and Electromagnetic Interference on High Frequency Electronic Integrity and Electromagnetic Interference on High Frequency Electronic Systems. by Luca Daniel Doctor

Daniel, Luca

22

Electromagnetic signatures of far-field gravitational radiation in the 1+3 approach  

E-Print Network [OSTI]

Gravitational waves from astrophysical sources can interact with background electromagnetic fields, giving rise to distinctive and potentially detectable electromagnetic signatures. In this paper, we study such interactions for far-field gravitational radiation using the 1+3 approach to relativity. Linearised equations for the electromagnetic field on perturbed Minkowski space are derived and solved analytically. The inverse Gertsenshtein conversion of gravitational waves in a static electromagnetic field is rederived, and the resultant electromagnetic radiation is shown to be significant for highly magnetised pulsars in compact binary systems. We also obtain a variety of nonlinear interference effects for interacting gravitational and electromagnetic waves, although wave-wave resonances previously described in the literature are absent when the electric-magnetic self-interaction is taken into account. The fluctuation and amplification of electromagnetic energy flux as the gravitational wave strength increases towards the gravitational-electromagnetic frequency ratio is a possible signature of gravitational radiation from extended astrophysical sources.

Alvin J. K. Chua; Priscilla Cañizares; Jonathan R. Gair

2014-12-06T23:59:59.000Z

23

Electromagnetic field with induced massive term: Case with scalar field  

E-Print Network [OSTI]

We consider an interacting system of massless scalar and electromagnetic field, with the Lagrangian explicitly depending on the electromagnetic potentials, i.e., interaction with broken gauge invariance. The Lagrangian for interaction is chosen in such a way that the electromagnetic field equation acquires an additional term, which in some cases is proportional to the vector potential of the electromagnetic field. This equation can be interpreted as the equation of motion of photon with induced nonzero rest-mass. This system of interacting fields is considered within the scope of Bianchi type-I (BI) cosmological model. It is shown that, as a result of interaction the electromagnetic field vanishes at $t \\to \\infty$ and the isotropization process of the expansion takes place.

Yu. P. Rybakov; G. N. Shikin; Yu. A. Popov; Bijan Saha

2010-04-21T23:59:59.000Z

24

Electromagnetic field with induced massive term: Case with spinor field  

E-Print Network [OSTI]

We consider an interacting system of spinor and electromagnetic field, explicitly depending on the electromagnetic potentials, i.e., interaction with broken gauge invariance. The Lagrangian for interaction is chosen in such a way that the electromagnetic field equation acquires an additional term, which in some cases is proportional to the vector potential of the electromagnetic field. This equation can be interpreted as the equation of motion of photon with induced non-trivial rest-mass. This system of interacting spinor and scalar fields is considered within the scope of Bianchi type-I (BI) cosmological model. It is shown that, as a result of interaction the electromagnetic field vanishes at $t \\to \\infty$ and the isotropization process of the expansion takes place.

Yu. P. Rybakov; G. N. Shikin; Yu. A. Popov; Bijan Saha

2010-08-12T23:59:59.000Z

25

Response of radio frequency superconducting quantum interference devices to electromagnetic interference  

SciTech Connect (OSTI)

A number of applications of high-temperature superconductor radio frequency superconducting quantum interference devices (rf SQUIDs) require a certain immunity of these sensors against electromagnetic interference (EMI). We have investigated effects of electromagnetic radiation in the high-frequency and ultrahigh-frequency range on various types of rf SQUIDs. It has been found that EMI of sufficient field strength reduces the voltage versus flux transfer function, and thus increases the flux noise of the SQUIDs. SQUIDs with a wire wound tank circuit coil have been found to be more sensitive to EMI than SQUIDs integrated into a superconducting microstrip resonator. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Mueck, M.; Dechert, J.; Gail, J.; Kreutzbruck, M.; Schoene, S.; Weidl, R. [Institut fuer Angewandte Physik, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)] [Institut fuer Angewandte Physik, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)

1995-09-01T23:59:59.000Z

26

Singular Modes of the Electromagnetic Field  

E-Print Network [OSTI]

We show that the mode corresponding to the point of essential spectrum of the electromagnetic scattering operator is a vector-valued distribution representing the square root of the three-dimensional Dirac's delta function. An explicit expression for this singular mode in terms of the Weyl sequence is provided and analyzed. An essential resonance thus leads to a perfect localization (confinement) of the electromagnetic field, which in practice, however, may result in complete absorption.

Neil V. Budko; Alexander B. Samokhin

2006-06-15T23:59:59.000Z

27

Singular Modes of the Electromagnetic Field  

E-Print Network [OSTI]

We show that the mode corresponding to the point of essential spectrum of the electromagnetic scattering operator is a vector-valued distribution representing the square root of the three-dimensional Dirac's delta function. An explicit expression for this singular mode in terms of the Weyl sequence is provided and analyzed. An essential resonance thus leads to a perfect localization (confinement) of the electromagnetic field, which in practice, however, may result in complete absorption.

Budko, N V; Budko, Neil V.; Samokhin, Alexander B.

2006-01-01T23:59:59.000Z

28

Hydrodynamic construction of the electromagnetic field  

E-Print Network [OSTI]

We present an alternative Eulerian hydrodynamic model for the electromagnetic field in which the discrete vector indices in Maxwell\\s equations are replaced by continuous angular freedoms, and develop the corresponding Lagrangian picture in which the fluid particles have rotational and translational freedoms. This enables us to extend to the electromagnetic field the exact method of state construction proposed previously for spin 0 systems, in which the time-dependent wavefunction is computed from a single-valued continuum of deterministic trajectories where two spacetime points are linked by at most a single orbit. The deduction of Maxwell\\s equations from continuum mechanics is achieved by generalizing the spin 0 theory to a general Riemannian manifold from which the electromagnetic construction is extracted as a special case. In particular, the flat-space Maxwell equations are represented as a curved-space Schr\\"odinger equation for a massive system. The Lorentz covariance of the Eulerian field theory is obtained from the non-covariant Lagrangian-coordinate model as a kind of collective effect. The method makes manifest the electromagnetic analogue of the quantum potential that is tacit in Maxwell\\s equations. This implies a novel definition of the \\classical limit\\ of Maxwell\\s equations that differs from geometrical optics. It is shown that Maxwell\\s equations may be obtained by canonical quantization of the classical model. Using the classical trajectories a novel expression is derived for the propagator of the electromagnetic field in the Eulerian picture. The trajectory and propagator methods of solution are illustrated for the case of a light wave.

Peter Holland

2014-10-03T23:59:59.000Z

29

Self-focusing of intense high frequency electromagnetic waves in a collisional magnetoactive plasma  

SciTech Connect (OSTI)

The self-focusing of an intense electromagnetic beam in a collisional magnetoactive plasma has been investigated by the perturbation method. Considering the relativistic and ponderomotive nonlinearities and the first three terms of perturbation expansion for the electron density and velocity, the nonlinear wave equation is obtained. This wave equation is solved by applying the source dependent expansion method and the evolution of electromagnetic beam spot-size is discussed. It is shown that the laser spot-size decreases with increasing the collision frequency and external magnetic field strength.

Niknam, A. R.; Hashemzadeh, M. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Evin, Tehran (Iran, Islamic Republic of); Aliakbari, A.; Majedi, S. [Physics Department, Faculty of Science, Tafresh University, Tafresh (Iran, Islamic Republic of); Haji Mirzaei, F. [Physics Department, Islamic Azad University, Arak Branch, Arak (Iran, Islamic Republic of)

2011-11-15T23:59:59.000Z

30

High frequency electromagnetic burn monitoring for underground coal gasification  

SciTech Connect (OSTI)

This paper describes the use of high frequency electromagnetic waves to monitor an in-situ coal gasification burn process, and presents some recent results obtained with the method. Both the technique, called HFEM (high frequency electromagnetic) probing, the HFEM hardware used are described, and some of the data obtained from the LLNL Hoe Creek No. 3 underground coal gasification experiment conducted near Gillette, Wyoming are presented. HFEM was found to be very useful for monitoring the burn activity found in underground coal gasification. The technique, being a remote sensing method which does not require direct physical contact, does not suffer from burnout problems as found with thermocouples, and can continue to function even as the burn progresses on through the region of interest. While HFEM does not replace more conventional instrumentation such as thermocouples, the method does serve to provide data which is unobtainable by other means, and in so doing it complements the other data to help form a picture of what cannot be seen underground.

Deadrick, F.J.; Hill, R.W.; Laine, E.F.

1981-06-17T23:59:59.000Z

31

Electromagnetic field at Finite Temperature: A first order approach  

E-Print Network [OSTI]

In this work we study the electromagnetic field at Finite Temperature via the massless DKP formalism. The constraint analysis is performed and the partition function for the theory is constructed and computed. When it is specialized to the spin 1 sector we obtain the well-known result for the thermodynamic equilibrium of the electromagnetic field.

R. Casana; B. M. Pimentel; J. S. Valverde

2007-02-04T23:59:59.000Z

32

Three-Dimensional Electromagnetic High Frequency Axisymmetric Cavity Scars.  

SciTech Connect (OSTI)

This report examines the localization of high frequency electromagnetic fi elds in three-dimensional axisymmetric cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This report treats both the case where the opposing sides, or mirrors, are convex, where there are no interior foci, and the case where they are concave, leading to interior foci. The scalar problem is treated fi rst but the approximations required to treat the vector fi eld components are also examined. Particular att ention is focused on the normalization through the electromagnetic energy theorem. Both projections of the fi eld along the scarred orbit as well as point statistics are examined. Statistical comparisons are m ade with a numerical calculation of the scars run with an axisymmetric simulation. This axisymmetric cas eformstheoppositeextreme(wherethetwomirror radii at each end of the ray orbit are equal) from the two -dimensional solution examined previously (where one mirror radius is vastly di ff erent from the other). The enhancement of the fi eldontheorbitaxiscanbe larger here than in the two-dimensional case. Intentionally Left Blank

Warne, Larry K.; Jorgenson, Roy E.

2014-10-01T23:59:59.000Z

33

Characterization of microstructure with low frequency electromagnetic techniques  

SciTech Connect (OSTI)

A new computational method for characterizing the relationship between surface crystallography and electrical conductivity in anisotropic materials with low frequency electromagnetic techniques is presented. The method is discussed from the standpoint of characterizing the orientation of a single grain, as well as characterizing statistical information about grain ensembles in the microstructure. Large-area electron backscatter diffraction (EBSD) data was obtained and used in conjunction with a synthetic aperture approach to simulate the eddy current response of beta annealed Ti-6Al-4V. Experimental eddy current results are compared to the computed eddy current approximations based on electron backscatter diffraction (EBSD) data, demonstrating good agreement. The detectability of notches in the presence of noise from microstructure is analyzed with the described simulation method and advantages and limitations of this method are discussed relative to other NDE techniques for such analysis.

Cherry, Matthew R.; Sathish, Shamachary [University of Dayton Research Institute, Structural Integrity Division, 300 College Park, Dayton, OH 45469-0020 (United States); Pilchak, Adam L.; Blodgett, Mark P. [Air Force Research Laboratory, Materials and Manufacturing Directorate (AFRL/RXCM), 2230 10th St., WPAFB, OH 45433 (United States); Cherry, Aaron J. [Southwest Ohio Council for Higher Education, 3155 Research Blvd., Suite 204, Dayton, OH 45420-4015 (United States)

2014-02-18T23:59:59.000Z

34

Heating of ions by high frequency electromagnetic waves in magnetized plasmas  

SciTech Connect (OSTI)

The heating of ions by high frequency electrostatic waves in magnetically confined plasmas has been a paradigm for studying nonlinear wave-particle interactions. The frequency of the waves is assumed to be much higher than the ion cyclotron frequency and the waves are taken to propagate across the magnetic field. In fusion type plasmas, electrostatic waves, like the lower hybrid wave, cannot access the core of the plasma. That is a domain for high harmonic fast waves or electron cyclotron waves—these are primarily electromagnetic waves. Previous studies on heating of ions by two or more electrostatic waves are extended to two electromagnetic waves that propagate directly across the confining magnetic field. While the ratio of the frequency of each wave to the ion cyclotron frequency is large, the frequency difference is assumed to be near the ion cyclotron frequency. The nonlinear wave-particle interaction is studied analytically using a two time-scale canonical perturbation theory. The theory elucidates the effects of various parameters on the gain in energy by the ions—parameters such as the amplitudes and polarizations of the waves, the ratio of the wave frequencies to the cyclotron frequency, the difference in the frequency of the two waves, and the wave numbers associated with the waves. For example, the ratio of the phase velocity of the envelope formed by the two waves to the phase velocity of the carrier wave is important for energization of ions. For a positive ratio, the energy range is much larger than for a negative ratio. So waves like the lower hybrid waves will impart very little energy to ions. The theoretical results are found to be in good agreement with numerical simulations of the exact dynamical equations. The analytical results are used to construct mapping equations, simplifying the derivation of the motion of ions, which are, subsequently, used to follow the evolution of an ion distribution function. The heating of ions can then be properly quantified in terms of the wave parameters and can be conveniently used to find ideal conditions needed to heat ions by high frequency electromagnetic waves.

Zestanakis, P. A.; Kominis, Y.; Hizanidis, K. [School of Electrical and Computer Engineering, National Technical University of Athens, Association EURATOM-Hellenic Republic, Zographou GR-15773 (Greece)] [School of Electrical and Computer Engineering, National Technical University of Athens, Association EURATOM-Hellenic Republic, Zographou GR-15773 (Greece); Ram, A. K. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2013-07-15T23:59:59.000Z

35

Electromagnetic Field Creation During EWPT Nucleation With Lepton Currents  

E-Print Network [OSTI]

We include the electromagnetic currents from fermion degrees of freedom in the equations of motion for electroweak MSSM with a right-handed Stop that we have recently investigated. It is found that near the surface of the bubble walls there are important effects on the electromagnetic fields produced during bubble nucleation.

Leonard S. Kisslinger; Sameer Walawalkar; Ernest M. Henley; Mikkel B. Johnson

2005-10-11T23:59:59.000Z

36

E-Print Network 3.0 - ac electromagnetic field Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Topics (time permitting). 12;The Nature of Electromagnetism Electric and magnetic fields... that are coupled; they are then referred to as an electromagnetic field....

37

Effects of Electromagnetic Fields on Fish and Invertebrates  

SciTech Connect (OSTI)

In this progress report, we describe the preliminary experiments conducted with three fish and one invertebrate species to determine the effects of exposure to electromagnetic fields. During fiscal year 2010, experiments were conducted with coho salmon (Onchrohychus kisutch), California halibut (Paralicthys californicus), Atlantic halibut (Hippoglossus hippoglossus), and Dungeness crab (Cancer magister). The work described supports Task 2.1.3: Effects on Aquatic Organisms, Subtask 2.1.3.1: Electromagnetic Fields.

Schultz, Irvin R.; Woodruff, Dana L.; Marshall, Kathryn E.; Pratt, William J.; Roesijadi, Guritno

2010-10-13T23:59:59.000Z

38

The Stability of a Shearing Viscous Star with Electromagnetic Field  

E-Print Network [OSTI]

We analyze the role of electromagnetic field for the stability of shearing viscous star with spherical symmetry. Matching conditions are given for the interior and exterior metrics. We use perturbation scheme to construct the collapse equation. The range of instability is explored in Newtonian and post Newtonian (pN) limits. We conclude that the electromagnetic field diminishes the effects of shearing viscosity in the instability range and makes the system more unstable at both Newtonian and post Newtonian approximations.

M. Sharif; M. Azam

2013-12-04T23:59:59.000Z

39

Electromagnetic field of a charge intersecting a cold plasma boundary in a waveguide  

SciTech Connect (OSTI)

We analyze the electromagnetic field of a charge crossing a boundary between a vacuum and cold plasma in a waveguide. We obtain exact expressions for the field components and the spectral density of the transition radiation. With the steepest descent technique, we investigate the field components. We show that the electromagnetic field has a different structure in a vacuum than in cold plasma. We also develop an algorithm for the computation of the field based on a certain transformation of the integration path. The behavior of the field depending on distance and time and the spectral density depending on frequency are explored for different charge velocities. Some important physical effects are noted. A considerable increase and concentration of the field near the wave front in the plasma is observed for the case of ultrarelativistic particles. In the plasma, the mode envelopes and spectral density show zero points when the charge velocity is within certain limits.

Alekhina, Tatiana Yu.; Tyukhtin, Andrey V. [Radiophysics Department of St. Petersburg University, 1 Ulyanovskaya, St. Petersburg 198504 (Russian Federation)

2011-06-15T23:59:59.000Z

40

Pair and Impar, Even and Odd Form Fields and Electromagnetism  

E-Print Network [OSTI]

In this paper after reviewing the Schouten and de Rham definition of impair and pair differential form fields (not to be confused with differential form fields of even and odd grades) we prove that in a relativistic spacetime it is possible (despite claims in contrary) to coherently formulate electromagnetism (and we believe any other physical theory) using only pair form fields or, if one wishes, using pair and impair form fields together, in an appropriate way. Those two distinct descriptions involve only a mathematical choice and do not seem to lead to any observable physical consequence if due care is taken. Moreover, we show in details that a formulation of electromagnetic theory in the Clifford bundle formalism of differential forms where the two Maxwell equations of the so called free metric approach becomes a single equation is compatible with both formulations of electromagnetism just mentioned above. Moreover we derive directly from Maxwell equation the density of force (coupling of the electromagnetic field with the charge current) that is a postulate in the free metric approach to electromagnetism. We recall also a formulation of the engineering version of Maxwell equations using electric and magnetic fields as objects of the same nature, i.e., without using polar and axial vectors.

Roldao da Rocha; Waldyr A. Rodrigues Jr

2009-08-13T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

An investigation of the usefulness of extremely low-frequency electromagnetic measurements for treaty verification  

SciTech Connect (OSTI)

From FY 1986 through FY 1988, we monitored extremely low-frequency (ELF) electromagnetic (EM) fields to determine whether these signals could be detected from underground nuclear explosions. Signals clearly related to underground tests were detected only when the ELF field sensors were located within 10 km of surface ground zero. Theoretical analysis, based on the results of these measurements, shows that the ELF impulse signals from underground nuclear tests are of longer duration than those from lightning sources and are, therefore, less efficient in exciting resonances in the earth-ionosphere cavity, even though the source strength for each may be the same. Thus, ELF signals from underground nuclear tests with yields of <150 kT are generally lower than the background signals caused by worldwide lightning activity. Our conclusion is that ELF monitoring probably will not be useful for detecting underground nuclear tests at distances >10 km from the tests. 16 refs., 24 figs., 3 tabs.

Sweeney, J.J.

1989-01-01T23:59:59.000Z

42

Electromagnetic Field Quantization in Time-Dependent Dielectric Media  

E-Print Network [OSTI]

We present a Gupta-Bleuler quantization scheme for the electromagnetic field in time-dependent dielectric media. Starting from the Maxwell equations, a generalization of the Lorentz gauge condition adapted to time varying dielectrics is derived. Using this gauge, a Gupta-Bleuler approach to quantize all polarizations of the radiation field and the corresponding constraint condition are introduced. This new approach is different from the quantized electromagnetic field in vacuum in the sense that here the contributions of unphysical photons cannot be thoroughly eliminated, which further lead to a surface charge density. Finally, a discussion of potential experimental tests and possible implication is also made.

Xiao-Min Bei; Zhong-Zhu Liu

2011-04-18T23:59:59.000Z

43

Electromagnetic waves destabilized by runaway electrons in near-critical electric fields  

SciTech Connect (OSTI)

Runaway electron distributions are strongly anisotropic in velocity space. This anisotropy is a source of free energy that may destabilize electromagnetic waves through a resonant interaction between the waves and the energetic electrons. In this work, we investigate the high-frequency electromagnetic waves that are destabilized by runaway electron beams when the electric field is close to the critical field for runaway acceleration. Using a runaway electron distribution appropriate for the near-critical case, we calculate the linear instability growth rate of these waves and conclude that the obliquely propagating whistler waves are most unstable. We show that the frequencies, wave numbers, and propagation angles of the most unstable waves depend strongly on the magnetic field. Taking into account collisional and convective damping of the waves, we determine the number density of runaways that is required to destabilize the waves and show its parametric dependences.

Komar, A.; Pokol, G. I. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Association EURATOM, H-1111 Budapest (Hungary); Fueloep, T. [Department of Applied Physics, Nuclear Engineering, Chalmers University of Technology and Euratom-VR Association, Goeteborg (Sweden)

2013-01-15T23:59:59.000Z

44

ELECTROMAGNETIC RADIATION FROM A STRONG DC ELECTRIC FIELD  

E-Print Network [OSTI]

ELECTROMAGNETIC RADIATION FROM A STRONG DC ELECTRIC FIELD Manuel G¨udel 1 and Donat G. Wentzel 2 1 accelerated by a strong dc electric field show not only very efficient generation of beam waves but also emission of o­mode radiation. We present a set of particle simulations for which we study the behavior

Guedel, Manuel

45

Lattice p-Form Electromagnetism and Chain Field Theory  

E-Print Network [OSTI]

Since Wilson's work on lattice gauge theory in the 1970s, discrete versions of field theories have played a vital role in fundamental physics. But there is recent interest in certain higher dimensional analogues of gauge theory, such as p-form electromagnetism, including the Kalb-Ramond field in string theory, and its nonabelian generalizations. It is desirable to discretize such `higher gauge theories' in a way analogous to lattice gauge theory, but with the fundamental geometric structures in the discretization boosted in dimension. As a step toward studying discrete versions of more general higher gauge theories, we consider the case of p-form electromagnetism. We show that discrete p-form electromagnetism admits a simple algebraic description in terms of chain complexes of abelian groups. Moreover, the model allows discrete spacetimes with quite general geometry, in contrast to the regular cubical lattices usually associated with lattice gauge theory. After constructing a suitable model of discrete spacetime for p-form electromagnetism, we quantize the theory using the Euclidean path integral formalism. The main result is a description of p-form electromagnetism as a `chain field theory' -- a theory analogous to topological quantum field theory, but with chain complexes replacing manifolds. This, in particular, gives a notion of time evolution from one `spacelike slice' of discrete spacetime to another.

Derek K. Wise

2005-10-08T23:59:59.000Z

46

A Continuous Field Theory of Matter and Electromagnetism  

E-Print Network [OSTI]

A continuous field theory of matter and electromagnetism is developed. The starting point of the theory is the classical Maxwell equations which are directly tied to the Riemann-Christoffel curvature tensor. This is done through the derivatives of the Maxwell tensor which are equated to a vector field contracted with the curvature tensor. The electromagnetic portion of the theory is shown to be equivalent to the classical Maxwell equations with the addition of a hidden variable. Because the proposed equations describing electromagnetism and matter differ from the classical Maxwell-Einstein equations, their ability to describe classical physics is shown for several situations by direct calculation. The inclusion of antimatter and the possibility of particle-like solutions exhibiting both quantized charge and mass are discussed.

Raymond J. Beach

2012-08-31T23:59:59.000Z

47

1D subsurface electromagnetic fields excited by energized steel casing  

E-Print Network [OSTI]

1D subsurface electromagnetic fields excited by energized steel casing Wei Yang1 , Carlos Torres the possibility of enabling steel-cased wells as galvanic sources to detect and quantify spatial variations of electrical conductivity in the subsurface. The study assumes a vertical steel-cased well that penetrates

Torres-Verdín, Carlos

48

Electromagnetically induced transparency with quantized fields in optocavity mechanics  

SciTech Connect (OSTI)

We report electromagnetically induced transparency (EIT) using quantized fields in optomechanical systems. The weak probe field is a narrowband squeezed field. We present a homodyne detection of EIT in the output quantum field. We find that the EIT dip exists even though the photon number in the squeezed vacuum is at the single-photon level. The EIT with quantized fields can be seen even at temperatures on the order of 100 mK, thus paving the way for using optomechanical systems as memory elements.

Huang Sumei; Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

2011-04-15T23:59:59.000Z

49

Electromagnetic field quantization in a linear dielectric medium  

E-Print Network [OSTI]

By modeling a dielectric medium with two independent reservoirs, i.e., electric and magnetic reservoirs, the electromagnetic field is quantized in a linear dielectric medium consistently. A Hamiltonian is proposed from which using the Heisenberg equations, not only the Maxwell equations but also the structural equations can be obtained. Using the Laplace transformation, the wave equation for the electromagnetic vector potential is solved in the case of a homogeneous dielectric medium. Some examples are considered showing the applicability of the model to both absorptive and nonabsorptive dielectrics.

F. Kheirandish; M. Amooshahi

2005-11-13T23:59:59.000Z

50

Spectrally isomorphic Dirac systems: graphene in electromagnetic field  

E-Print Network [OSTI]

We construct the new one-dimensional Dirac Hamiltonians that are spectrally isomorphic (not isospectral) with the known exactly solvable models. Explicit formulas for their spectra and eigenstates are provided. The operators are utilized for description of Dirac fermions in graphene in presence of an inhomogeneous electromagnetic field. We discuss explicit, physically relevant, examples of spectrally isomorphic systems with both non-periodic and periodic electromagnetic barriers. In the latter case, spectrally isomorphic two- and three-gap systems associated with the Ablowitz-Kaup-Newell-Segur hierarchy are considered.

Jakubsky, Vit

2014-01-01T23:59:59.000Z

51

Laser photon merging in an electromagnetic field inhomogeneity  

E-Print Network [OSTI]

We study the effect of laser photon merging, or equivalently high harmonic generation, in the quantum vacuum subject to inhomogeneous electromagnetic fields. Such a process is facilitated by the effective nonlinear couplings arising from charged particle-antiparticle fluctuations in the quantum vacuum subject to strong electromagnetic fields. We derive explicit results for general kinematic and polarization configurations involving optical photons. Concentrating on merged photons in reflected channels which are preferable in experiments for reasons of noise suppression, we demonstrate that photon merging is typically dominated by the competing nonlinear process of quantum reflection, though appropriate polarization and signal filtering could specifically search for the merging process. As a byproduct, we devise a novel systematic expansion of the photon polarization tensor in plane wave fields.

Holger Gies; Felix Karbstein; Rashid Shaisultanov

2014-08-13T23:59:59.000Z

52

A stable frequency comb directly referenced to rubidium electromagnetically induced transparency and two-photon transitions  

SciTech Connect (OSTI)

We demonstrate an approach to create a stable erbium-fiber-based frequency comb at communication band by directly locking the combs to two rubidium atomic transitions resonances (electromagnetically induced transparency absorption and two-photon absorption), respectively. This approach directly transfers the precision and stability of the atomic transitions to the comb. With its distinguishing feature of compactness by removing the conventional octave-spanning spectrum and f-to-2f beating facilities and the ability to directly control the comb's frequency at the atomic transition frequency, this stable optical comb can be widely used in optical communication, frequency standard, and optical spectroscopy and microscopy.

Hou, Dong; Wu, Jiutao; Zhang, Shuangyou; Ren, Quansheng; Zhang, Zhigang; Zhao, Jianye, E-mail: zhaojianye@pku.edu.cn [Department of Electronics, Peking University, Beijing, 100871 (China)

2014-03-17T23:59:59.000Z

53

PARTICLE FILTER BASED MULTI-SENSOR FUSION FOR SOLVING LOW FREQUENCY ELECTROMAGNETIC NDE INVERSE PROBLEMS  

E-Print Network [OSTI]

PARTICLE FILTER BASED MULTI-SENSOR FUSION FOR SOLVING LOW FREQUENCY ELECTROMAGNETIC NDE INVERSE 48824 khantari,sdass@msu.edu, r.pradeep@ieee.org Abstract: Flaw profile characterization from NDE from multi-sensor data is considered. The NDE inverse problem is posed as a statistical inverse problem

Dass, Sarat C.

54

Ultrarelativistic electron states in a general background electromagnetic field  

E-Print Network [OSTI]

The feasibility of obtaining exact analytical results in the realm of QED in the presence of a background electromagnetic field is almost exclusively limited to a few tractable cases, where the Dirac equation in the corresponding background field can be solved analytically. This circumstance has restricted, in particular, the theoretical analysis of QED processes in intense laser fields to within the plane-wave approximation even at those high intensities, achievable experimentally only by tightly focusing the laser energy in space. Here, within the Wentzel-Kramers-Brillouin (WKB) or eikonal approximation, we construct analytically single-particle electron states in the presence of a background electromagnetic field of general space-time structure in the realistic assumption that the initial energy of the electron is the largest dynamical energy scale in the problem. The relatively compact expression of these states opens, in particular, the possibility of investigating analytically strong-field QED processes in the presence of spatially focused laser beams, which is of particular relevance in view of the upcoming experimental campaigns in this field.

A. Di Piazza

2014-07-27T23:59:59.000Z

55

Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields  

DOE Patents [OSTI]

A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

Clark, M.C.; Coleman, P.D.; Marder, B.M.

1993-08-10T23:59:59.000Z

56

Infrared nullification of the effective electromagnetic field at finite temperature  

E-Print Network [OSTI]

The problem of infrared divergence of the effective electromagnetic field at finite temperature (T) is revisited. A model of single spatially localized electron interacting with thermal photons is considered in the limit T to 0 using two different regularization schemes. The first is based on the shift i 0 to i varepsilon of the electron propagator pole in the complex energy plane, and is used to explicitly calculate the effective field in the one-loop approximation. We show that the matrix-valued imaginary part of the electron self-energy can be consistently related to the pole shift, and that the presence of the heat bath leads to appearance of an effective varepsilon sim T, thus providing a natural infrared regulator of the theory. We find that the one-loop effective Coulomb field calculated using this varepsilon vanishes. The other scheme combines an infrared momentum cutoff with smearing of the delta-functions in the interaction vertices. We prove that this regularization admits factorization of the infrared contributions in multi-loop diagrams, and sum the corresponding infinite series. The effective electromagnetic field is found to vanish in this case too. An essentially perturbative nature of this result is emphasized and discussed in connection with the long-range expansion of the effective field.

Kirill A. Kazakov; Vladimir V. Nikitin

2009-10-30T23:59:59.000Z

57

Rayleigh-Taylor-Induced electromagnetic fields in laser-produced plasmas  

E-Print Network [OSTI]

Spontaneous electromagnetic fields can be important to the dynamic evolution of a plasma by directing heat flow as well as providing additional pressures on the conducting fluids through the Lorentz force. Electromagnetic ...

Manuel, Mario John-Errol

2013-01-01T23:59:59.000Z

58

Propagation of terahertz electromagnetic wave in plasma with inhomogeneous collision frequency  

SciTech Connect (OSTI)

In this paper, we investigate the absorption spectra of terahertz electromagnetic wave in plasma with inhomogeneous collision frequency. Profiles are introduced to describe the non-uniformity of collision frequency. It is interesting to find that when the plasma is collision frequency inhomogeneous, the absorption spectrum would decreases faster than that in uniform plasma. And the rate of decreasing would be different when the profile changes. Two parameters are set up to predict how the profiles affect the absorption spectra. Furthermore, the effects of electron density are also considered.

Tian, Yuan; Han, YiPing; Ling, YingJie [School of Physics and Optoelectronic Engineering, Xidian University, Xi'an 710071 (China)] [School of Physics and Optoelectronic Engineering, Xidian University, Xi'an 710071 (China); Ai, Xia [National Laboratory of Science and Technology on Antennas and Microwaves Xidian University, Xi'an 710071 (China)] [National Laboratory of Science and Technology on Antennas and Microwaves Xidian University, Xi'an 710071 (China)

2014-02-15T23:59:59.000Z

59

Instability-driven electromagnetic fields in coronal plasmas  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Filamentary electromagnetic fields previously observed in the coronae of laser-driven spherical targets [F. H. S#2;eguin et al., Phys. Plasma. 19, 012701 (2012)] have been further investigated in laser irradiated plastic foils. Face-on proton-radiography provides an axial view of these filaments and shows coherent cellular structure regardless of initial foil-surface conditions. The observed cellular fields are shown to have an approximately constant scale size of #2;210 lm throughout the plasma evolution. A discussion of possible field-generation mechanisms is provided and it is demonstrated that the likely source of the cellular field structure is the magnetothermal instability. Using predicted temperature and density profiles, the fastest growing modes of this instability were found to be slowly varying in time and consistent with the observed cellular size.

Manuel, M. J.-E.; Li, C. K.; Seguin, F. H.; Sinenian, N.; Frenje, J. A.; Casey, D. T.; Petrasso, R. D.; Hager, J. D.; Betti, R.; Hu, S. X.; Delettrez, J.; Meyerhofer, D. D.

2013-01-01T23:59:59.000Z

60

A field test of electromagnetic geophysical techniques for locating simulated in situ mining leach solution  

SciTech Connect (OSTI)

The US Bureau of Mines, The University of Arizona, Sandia National Laboratories, and Zonge Engineering and Research Organization, Inc., conducted cooperative field tests of six electromagnetic (EM) geophysical methods to compare their effectiveness in locating a brine solution simulating in situ leach solution or a high-conductivity plume of contamination. The brine was approximately 160 m below the surface. The testsite was the University's San Xavier experimental mine near Tucson, AZ. Geophysical surveys using surface and surface-borehole, time-domain electromagnetic (TEM) induction; surface controlled-source audiofrequency magnetotellurics (CSAMT); surface-borehole, frequency-domain electromagnetic (FEM) induction; crosshole FEM; and surface magnetic field ellipticity were conducted before and during brine injection. The surface TEM data showed a broad decrease in resistivity. CSAMT measurements with the conventional orientation did not detect the brine, but measurements with another orientation indicated some decrease in resistivity. The surface-borehole and crosshole methods located a known fracture and other fracture zones inferred from borehole induction logs. Surface magnetic field ellipticity data showed a broad decrease in resistivity at depth following brine injection.

Tweeton, D.R.; Hanson, J.C.; Friedel, M.J.; Sternberg, B.K.; Dahl, L.J.

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Essential state of the electromagnetic field and the double-slit experiment  

E-Print Network [OSTI]

A new class of generalized solutions related to the essential spectrum of linear Maxwell's equations is presented. The essential modes are given in terms of normalized singular Weyl's sequences, whose square represents Dirac's delta functions in spatial and angular frequency domains. The action integral associated with essential modes is well-defined. We claim that these modes represent the collapsed state of the electromagnetic field and, with some additional assumptions on the conservation of action, are suitable for describing the double-slit experiment in accordance with the orthodox point of view.

Budko, N V; Budko, Neil V.; Samokhin, Alexander B.

2006-01-01T23:59:59.000Z

62

Essential state of the electromagnetic field and the double-slit experiment  

E-Print Network [OSTI]

A new class of generalized solutions related to the essential spectrum of linear Maxwell's equations is presented. The essential modes are given in terms of normalized singular Weyl's sequences, whose square represents Dirac's delta functions in spatial and angular frequency domains. The action integral associated with essential modes is well-defined. We claim that these modes represent the collapsed state of the electromagnetic field and, with some additional assumptions on the conservation of action, are suitable for describing the double-slit experiment in accordance with the orthodox point of view.

Neil V. Budko; Alexander B. Samokhin

2006-10-02T23:59:59.000Z

63

Variational Principles for Constrained Electromagnetic Field and Papapetrou Equation  

E-Print Network [OSTI]

In our previous article [4] an approach to derive Papapetrou equations for constrained electromagnetic field was demonstrated by use of field variational principles. The aim of current work is to present more universal technique of deduction of the equations which could be applied to another types of non-scalar fields. It is based on Noether theorem formulated in terms of Cartan' formalism of orthonormal frames. Under infinitesimal coordinate transformation the one leads to equation which includes volume force of spin-gravitational interaction. Papapetrou equation for vector of propagation of the wave is derived on base of the equation. Such manner of deduction allows to formulate more accurately the constraints and clarify equations for the potential and for spin.

A. T. Muminov

2007-06-28T23:59:59.000Z

64

Electromagnetic Field in de Sitter Expanding Universe: Majorana--Oppenheimer Formalism, Exact Solutions in non-Static Coordinates  

E-Print Network [OSTI]

Tetrad-based generalized complex formalism by Majorana--Oppenheimer is applied to treat electromagnetic field in extending de Sitter Universe in on-static spherically-symmetric coordinates. With the help of Wigner D-functions, we separate angular dependence in the complex vector field E_{j}(t,r)+i B_{j}(t,r) from (t,r)-dependence. The separation parameter arising here instead of frequency \\omega in Minkowski space-time is quantized, non-static geometry of the de Sitter model leads to definite dependence of electromagnetic modes on the time variable. Relation of 3-vector complex approach to 10-dimensional Duffin-Kemmer-Petiau formalism is considered. On this base, the electromagnetic waves of magnetic and electric type have been constructed in both approaches. In Duffin-Kemmer-Petiau approach, there are constructed gradient-type solutions in Lorentz gauge.

O. V. Veko; N. D Vlasii; Yu. A. Sitenko; E. M. Ovsiyuk; V. M. Red'kov

2014-10-30T23:59:59.000Z

65

Electromagnetic Field in de Sitter Expanding Universe: Majorana--Oppenheimer Formalism, Exact Solutions in non-Static Coordinates  

E-Print Network [OSTI]

Tetrad-based generalized complex formalism by Majorana--Oppenheimer is applied to treat electromagnetic field in extending de Sitter Universe in on-static spherically-symmetric coordinates. With the help of Wigner D-functions, we separate angular dependence in the complex vector field E_{j}(t,r)+i B_{j}(t,r) from (t,r)-dependence. The separation parameter arising here instead of frequency \\omega in Minkowski space-time is quantized, non-static geometry of the de Sitter model leads to definite dependence of electromagnetic modes on the time variable. Relation of 3-vector complex approach to 10-dimensional Duffin-Kemmer-Petiau formalism is considered. On this base, the electromagnetic waves of magnetic and electric type have been constructed in both approaches. In Duffin-Kemmer-Petiau approach, there are constructed gradient-type solutions in Lorentz gauge.

Veko, O V; Sitenko, Yu A; Ovsiyuk, E M; Red'kov, V M

2014-01-01T23:59:59.000Z

66

The electromagnetic fields and the radiation of a spatio-temporally varying electric current loop  

E-Print Network [OSTI]

The electric and magnetic fields of a spatio-temporally varying electric current loop are calculated using the Jefimenko equations. The radiation and the nonradiation parts of the electromagnetic fields are derived in the framework of Maxwell's theory of electromagnetic fields. In this way, a new, exact, analytical solution of the Maxwell equation is found.

Markus Lazar

2013-04-12T23:59:59.000Z

67

Quantum Energy Teleportation with Electromagnetic Field: Discrete vs. Continuous Variables  

E-Print Network [OSTI]

Local measurements of quantum fluctuation in the vacuum state of electromagnetic field require energy infusion to the field. The infused energy is diffused to spatial infinity with light velocity and the state of the field soon becomes a local vacuum with zero energy around the measurement area. Of cource we cannot retrieve energy from this measurement area if we do not know the measurement result of the fluctuation. However, if the measurement result is available for us, we are able to extract energy from the local vacuum of the field, applying the protocol of quantum energy teleportation recently proposed. By performing a local unitary operation around the measurement area dependent on the measurement result, the fluctuaion of zero-point oscillation is squeezed and negative energy density appears around the area, accompanied by extraction of positive energy from the field. In this paper, we compare two different protocols of the energy retrieval. In the first protocol, a 1/2 spin is coupled with the fluctua...

Hotta, Masahiro

2009-01-01T23:59:59.000Z

68

Equations of a Moving Mirror and the Electromagnetic Field  

E-Print Network [OSTI]

We consider a slab of a material that is linear, isotropic, non-magnetizable, ohmic, and electrically neutral when it is at rest. The slab interacts with the electromagnetic field through radiation pressure. Using a relativistic treatment, we deduce the exact equations governing the dynamics of the field and of the slab, as well as, approximate equations to first order in the velocity and the acceleration of the slab. As a consequence of the motion of the slab, the field must satisfy a wave equation with damping and slowly varying coefficients plus terms that are small when the time-scale of the evolution of the mirror is much smaller than that of the field. Moreover, the dynamics of the mirror involve a time-dependent mass arising from the interaction with the field and it is related to the effective mass of mechanical oscillators used in optomechanics. By the same reason, the mirror is subject to a velocity dependent force which is related to the much sought cooling of mechanical oscillators in optomechanics.

Luis Octavio Castaños; Ricardo Weder

2014-10-28T23:59:59.000Z

69

GL(3,R) gauge theory of gravity coupled with an electromagnetic field  

E-Print Network [OSTI]

Consistency of $GL(3,R)$ gauge theory of gravity coupled with an external electromagnetic field, is studied. It is shown that possible restrictions on Maxwell field can be avoided through introduction of auxiliary fields.

Rolando Gaitan; Frank Vera

2006-08-11T23:59:59.000Z

70

On the gravitational fields created by the electromagnetic waves  

E-Print Network [OSTI]

We show that the Maxwell equations describing an electromagnetic wave are a mathematical consequence of the Einstein equations for the same wave. This fact is significant for the problem of the Einsteinian metrics corresponding to the electromagnetic waves.

A. Loinger; T. Marsico

2011-06-11T23:59:59.000Z

71

Paternal occupational exposure to electromagnetic fields and neuroblastoma in offspring  

SciTech Connect (OSTI)

Investigators in Texas have reported an association between paternal employment in jobs linked with exposure to electromagnetic fields and risk of neuroblastoma in offspring. In an attempt to replicate this finding, the authors conducted a case-control study in Ohio. A total of 101 incident cases of neuroblastoma were identified through the Columbus (Ohio) Children's Hospital Tumor Registry. All cases were born sometime during the period 1942-1967. From a statewide roster of birth certificates, four controls were selected for each case, with individual matching on the case's year of birth, race, and sex, and the mother's county of residence at the time of the (index) child's birth. Multiple definitions were employed to infer the potential for paternal occupational exposure to electromagnetic fields from the industry/occupation statements on the birth certificates. Case-control comparisons revealed adjusted odds ratios ranging in magnitude from 0.5 to 1.9. For two of the exposure definitions employed--both of which are similar to one used by the Texas investigators--the corresponding odds ratios were modestly elevated (odds ratios = 1.6 and 1.9). Notably, the magnitude of these odds ratios is not inconsistent with the Texas findings, where the exposure definition referred to yielded an odds ratio of 2.1. Because the point estimates in this study are imprecise, and because the biologic plausibility of the association is uncertain, the results reported here must be interpreted cautiously. However, the apparent consistency between two independent studies suggests that future evaluation of the association is warranted.

Wilkins, J.R. 3d.; Hundley, V.D. (Ohio State Univ., Columbus (USA))

1990-06-01T23:59:59.000Z

72

Effect of electron density profile on power absorption of high frequency electromagnetic waves in plasma  

SciTech Connect (OSTI)

Considering different typical electron density profiles, a multi slab approximation model is built up to study the power absorption of broadband (0.75-30 GHz) electromagnetic waves in a partially ionized nonuniform magnetized plasma layer. Based on the model, the power absorption spectra for six cases are numerically calculated and analyzed. It is shown that the absorption strongly depends on the electron density fluctuant profile, the background electron number density, and the collision frequency. A potential optimum profile is also analyzed and studied with some particular parameters.

Xi Yanbin; Liu Yue [MOE Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2012-07-15T23:59:59.000Z

73

6.641 Electromagnetic Fields, Forces, and Motion, Spring 2003  

E-Print Network [OSTI]

Electric and magnetic quasistatic forms of Maxwell's equations applied to dielectric, conduction, and magnetization boundary value problems. Electromagnetic forces, force densities, and stress tensors, including magnetization ...

Zahn, Markus, 1946-

74

Electromagnetically induced transparency controlled by a microwave field  

E-Print Network [OSTI]

interferences in electromagnetically induced transparency. A simple theoretical model and a numerical simulation have been developed to explain the observed experimental results....

Li, Hebin; Sautenkov, Vladimir A.; Rostovtsev, Yuri V.; Welch, George R.; Hemmer, Philip R.; Scully, Marlan O.

2009-01-01T23:59:59.000Z

75

Low Frequency Electromagnetic Fields in High Contrast Media ?  

E-Print Network [OSTI]

ow monitoring, in underground contaminant detection, etc. In this paper we will focus attention, such as hydrocarbons, are poor conductors in comparison with other pore liquids, such as brines [4, 33]. Thus

Papanicolaou, George C.

76

Low Frequency Electromagnetic Fields in High Contrast Media ?  

E-Print Network [OSTI]

flow monitoring, in underground contaminant detection, etc. In this paper we will focus attention, such as hydrocarbons, are poor conductors in comparison with other pore liquids, such as brines [4, 33]. Thus

Borcea, Liliana

77

Lichnerowicz-Type Theorems for Self-gravitating Systems with Nonlinear Electromagnetic Fields  

E-Print Network [OSTI]

We consider a self-gravitating system containing a globally timelike Killing vector and a nonlinear Born-Infeld electromagnetic field and scalar fields. We prove that under certain boundary conditions (asymptotically flat/AdS) there can't be any nontrivial field configurations in the spacetime. To explore nontrivial solutions one should break any of the conditions we imposed. The case with another type of nonlinear electromagnetic field is also analyzed, and similar conclusions have been obtained under certain conditions.

Li-Ming Cao; Yuxuan Peng; Jianfei Xu

2014-07-11T23:59:59.000Z

78

Exact solution to the Landau-Lifshitz equation in a constant electromagnetic field  

E-Print Network [OSTI]

We are interested in the motion of a classical charge acted upon an external constant electromagnetic field where the back reaction of the particle's own field is taken into account. The Landau-Lifshitz approximation to the Lorentz-Abraham-Dirac equation is solved exactly and in closed form. It is shown that the ultrarelativistic limit of the Landau-Lifshitz equation for a radiating charge is the equation for eigenvalues and eigenvectors of the external electromagnetic field tensor.

Yurij Yaremko

2014-12-04T23:59:59.000Z

79

Effects of Electromagnetic Field on the Dynamical Instability of Expansionfree Gravitational Collapse  

E-Print Network [OSTI]

In this paper, we discuss the effects of electromagnetic field on the dynamical instability of a spherically symmetric expansionfree gravitational collapse. Darmois junction conditions are formulated by matching interior spherically symmetric spacetime to exterior Reissner-Nordstr$\\ddot{o}$m spacetime. We investigate the role of different terms in the dynamical equation at Newtonian and post Newtonian regimes by using perturbation scheme. It is concluded that instability range depends upon pressure anisotropy, radial profile of energy density and electromagnetic field, but not on the adiabatic index $\\Gamma$. In particular, the electromagnetic field reduces the unstable region.

M. Sharif; M. Azam

2013-05-31T23:59:59.000Z

80

Low-Frequency Electromagnetic Response Function for Strong-Coupling Superconductors  

E-Print Network [OSTI]

properties of superconduc- tors is well known. For example, the frequency dependence of the electrical conductivity in strong- coupling superconductors has been observed by both infrared" and microwave' techniques. Also, the magnitude and temperature... dependence of the low-frequency conductivity for Pb have been in- ferred from measurements of magnetic field at- tenuation, ' while kinetic inductance' measure- ments have been used to study this temperature dependence for amorphous superconductors...

SCHOLTEN, PD; LEJEUNE, JD; SASLOW, WM; Naugle, Donald G.

1977-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Gravitation and electromagnetism in theory of a unified four-vector field  

E-Print Network [OSTI]

A four-vector field in flat space-time, satisfying a gauge-invariant set of second-order differential equations, is considered as a unified field. The model variational principle corresponds to the general covariance idea and gives rise to nonlinear Born-Infeld electrodynamics. Thus the four-vector field is considered as an electromagnetic potential. It is suggested that space-localized (particle) solutions of the nonlinear field model correspond to material particles. Electromagnetic and gravitational interactions between field particles appear naturally when a many-particle solution is investigated with the help of a perturbation method. The electromagnetic interaction appears in the first order in the small field of distant particles. In the second order, there is an effective Riemannian space induced by the field of distant particles. This Riemannian space can be connected with gravitation.

Alexander A. Chernitskii

2006-09-28T23:59:59.000Z

82

Electromagnetic fields and transport coefficients in a hot pion gas  

E-Print Network [OSTI]

We present recent results on finite temperature electromagnetic form factors and the electrical conductivity in a pion gas. The standard Chiral Perturbation Theory power counting needs to be modified for transport coefficients. We pay special attention to unitarity and to possible applications for dilepton and photon production.

A. Gomez Nicola; D. Fernandez-Fraile

2006-08-24T23:59:59.000Z

83

Utilization of electromagnetic detector for selection and detection of high-frequency relic gravitational waves  

E-Print Network [OSTI]

It is shown that coupling system between fractal membranes and a Gaussian beam passing through a static magnetic field has strong selection capability for the stochastic relic gravitational wave background. The relic GW components propagating along the positive direction of the symmetrical axis of the Gaussian beam might generate an optimal electromagnetic perturbation while the perturbation produced by the relic GW components propagating along the negative and perpendicular directions to the symmetrical axis will be much less than the former.The influence of the random fluctuation of the relic GWs to such effect can be neglected and the influence of the random fluctuation of the relic GWs to such effect can be neglected.

Fangyu Li; Zhenya Chen; Ying Yi

2005-11-03T23:59:59.000Z

84

Total cross-section for photon-axion conversions in external electromagnetic field  

E-Print Network [OSTI]

We reconsider the conversion of the photon into axion in the external electromagnetic fields, namely in the static fields and in a periodic field of the wave guide. The total cross-sections for the conversion are evaluated in detail. The result shows that with strong strength of external electromagnetic fields, the cross-sections are large enough to measure the axion production. In the wave guide there exists the resonant conversion at the low energies, in which the value of cross-sections is much enhanced

D. V. Soa; H. N. Long; T. D. Tham

2014-02-20T23:59:59.000Z

85

Efficient Inversion of Mult-frequency and Multi-Source Electromagnetic Data  

SciTech Connect (OSTI)

The project covered by this report focused on development of efficient but robust non-linear inversion algorithms for electromagnetic induction data, in particular for data collected with multiple receivers, and multiple transmitters, a situation extremely common in eophysical EM subsurface imaging methods. A key observation is that for such multi-transmitter problems each step in commonly used linearized iterative limited memory search schemes such as conjugate gradients (CG) requires solution of forward and adjoint EM problems for each of the N frequencies or sources, essentially generating data sensitivities for an N dimensional data-subspace. These multiple sensitivities allow a good approximation to the full Jacobian of the data mapping to be built up in many fewer search steps than would be required by application of textbook optimization methods, which take no account of the multiplicity of forward problems that must be solved for each search step. We have applied this idea to a develop a hybrid inversion scheme that combines features of the iterative limited memory type methods with a Newton-type approach using a partial calculation of the Jacobian. Initial tests on 2D problems show that the new approach produces results essentially identical to a Newton type Occam minimum structure inversion, while running more rapidly than an iterative (fixed regularization parameter) CG style inversion. Memory requirements, while greater than for something like CG, are modest enough that even in 3D the scheme should allow 3D inverse problems to be solved on a common desktop PC, at least for modest (~ 100 sites, 15-20 frequencies) data sets. A secondary focus of the research has been development of a modular system for EM inversion, using an object oriented approach. This system has proven useful for more rapid prototyping of inversion algorithms, in particular allowing initial development and testing to be conducted with two-dimensional example problems, before approaching more computationally cumbersome three-dimensional problems.

Gary D. Egbert

2007-03-22T23:59:59.000Z

86

Free Form of the Foldy-Wouthuysen Transformation in External Electromagnetic Fields  

E-Print Network [OSTI]

We derive the exact Foldy-Wouthuysen transformation for Dirac fermions in a time independent external electromagnetic field in the basis of the Ritus eigenfunctions, namely the eigenfunctions of the operator $(\\gamma \\cdot \\Pi)^2$, with $\\Pi^\\mu = p^\\mu - e A^\\mu$. In this basis, the transformation acquires a free form involving the dynamical quantum numbers induced by the field.

Gabriela Murguia; Alfredo Raya

2010-08-29T23:59:59.000Z

87

MEASUREMENT AND ANALYSIS OF ELECTROMAGNETIC FIELDS FROM TRAMS, TRAINS AND HYBRID CARS  

E-Print Network [OSTI]

MEASUREMENT AND ANALYSIS OF ELECTROMAGNETIC FIELDS FROM TRAMS, TRAINS AND HYBRID CARS Malka N of electric and magnetic fields emitted from Australian trams, trains and hybrid cars were investigated (EMFs) has arisen. People using trains, trams and hybrid cars are exposed to higher alternating

Halgamuge, Malka N.

88

Derivation of Gell-Mann-Nishijima formula from the electromagnetic field modes of a hadron  

E-Print Network [OSTI]

When an electron probes another elementary particle Q, the wave function of the electron can be separated into two independent parts, the first part represents the electronic motion, the second part represents the electromagnetic field mode around the particle Q. In analogy with optical modes $TEM_{nlm}$ for a laser resonator, when the electromagnetic field around the particle Q forms into a mode, the quantum numbers of the mode satisfy the Gell-Mann-Nishijima formula, these quantum numbers are recognized as the charge number, baryon number and strangeness number. The modes are used as a visual model to understand the abstract baryon number and strangeness number of hadrons.

Huai-yang Cui

2010-07-23T23:59:59.000Z

89

arbitrary electromagnetic fields: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of the half-integer spin fields in the external field to an algebraic problem of search for a set of operators with certain algebraical features using the representation of...

90

Lagrangian formulation of massive fermionic higher spin fields on a constant electromagnetic background  

E-Print Network [OSTI]

We consider massive half-integer higher spin fields coupled to an external constant electromagnetic field in flat space of an arbitrary dimension and construct a gauge invariant Lagrangian in the linear approximation in the external field. A procedure for finding the gauge-invariant Lagrangians is based on the BRST construction where no off-shell constraints on the fields and on the gauge parameters are imposed from the very beginning. As an example of the general procedure, we derive a gauge invariant Lagrangian for a massive fermionic field with spin 3/2 which contains a set of auxiliary fields and gauge symmetries.

Buchbinder, I L; Tsulaia, M

2015-01-01T23:59:59.000Z

91

Stable pseudoanalytical computation of electromagnetic fields from arbitrarily-oriented dipoles in cylindrically stratified media  

E-Print Network [OSTI]

Computation of electromagnetic fields due to point sources (Hertzian dipoles) in cylindrically stratified media is a classical problem for which analytical expressions of the associated tensor Green's function have been long known. However, under finite-precision arithmetic, direct numerical computations based on the application of such analytical (canonical) expressions invariably lead to underflow and overflow problems related to the poor scaling of the eigenfunctions (cylindrical Bessel and Hankel functions) for extreme arguments and/or high-order, as well as convergence problems related to the numerical integration over the spectral wavenumber and to the truncation of the infinite series over the azimuth mode number. These problems are exacerbated when a disparate range of values is to be considered for the layers' thicknesses and material properties (resistivities, permittivities, and permeabilities), the transverse and longitudinal distances between source and observation points, as well as the source frequency. To overcome these challenges in a systematic fashion, we introduce herein different sets of range-conditioned, modified cylindrical functions (in lieu of standard cylindrical eigenfunctions), each associated with non-overlapped subdomains of (numerical) evaluation to allow for stable computations under any range of physical parameters. In addition adaptively-chosen integration contours are employed in the complex spectral wavenumber plane to ensure convergent numerical integration in all cases. We illustrate the application of the algorithm to problems of geophysical interest involving layer resistivities ranging from 1000 $\\Omega \\cdot$m to 10$^{-8} \\Omega \\cdot$m, frequencies of operation ranging from 10 MHz down to the low magnetotelluric range of 0.01 Hz, and for various combinations of layer thicknesses.

H. Moon; F. L. Teixeira; B. Donderici

2014-05-29T23:59:59.000Z

92

Instability of a liquid metal surface in an electromagnetic field and relevance to EMC  

SciTech Connect (OSTI)

In electromagnetic casting (EMC) the surface of the molten metal, at the solidification front around the periphery of the melt pool, is not confirmed by a solid mold (as in, say, direct chill casting) but is free to move. Consequently disturbances of the melt surface are reflected in defects (waviness) in the solid ingot. The present paper examines the dynamics of a liquid metal surface in an electromagnetic field comparable to that of EMC. Numerical calculations of the flow of metal and motion of the melt surface have been accompanied by laboratory experiments in which a laser vibrometer has been used to measure the oscillations of the free surface of a mercury pool. Surface oscillations growth with increasing electromagnetic field strength in both the computations and the experiment, probably originating from the turbulent flow in the melt. The implications for EMC are discussed.

Kageyama, R.; Evans, J.W. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

1996-10-01T23:59:59.000Z

93

ECEN 3410 -Electromagnetic Fields and Transmission Spring semester 2005, University of Colorado at Boulder  

E-Print Network [OSTI]

ECEN 3410 - Electromagnetic Fields and Transmission Spring semester 2005, University of Colorado the resistor. 14. The current intensity through a coil of inductance L is i(t). Find the flux of the Poynting vector through any closed surface enclosing the coil. 15. Why do we care about boundary conditions? How

Piestun, Rafael

94

Ion acoustic wave generation by a standing electromagnetic field in a subcritical plasma  

E-Print Network [OSTI]

233 Ion acoustic wave generation by a standing electromagnetic field in a subcritical plasma P.5 03BCs) is launched into a subcritical argon plasma (ne ~1011 cm-3, P0 ~ 5 10-4 Torr), resulting.35 1. Introduction. Our purpose is to study the ion acoustic wave excited in a subcritical plasma

Boyer, Edmond

95

athermal electromagnetic field: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

with non-integer Hausdorff dimensions. If electric and magnetic fields are defined on fractal and do not exist outside of fractal in Euclidean space, then we can use the...

96

Interacting Scalar and Electromagnetic Fields in $f(R,\\,T)$ Theory of Gravity  

E-Print Network [OSTI]

Within the scope of $f(R,\\,T)$ gravity we have studied the interacting scalar and electromagnetic fields in a Bianchi type I universe. It was found that if the study is confined to the case $f(R,\\,T) = R + \\lambda f(T)$, the system is completely given by the equations similar to Einstein gravity. Moreover, the present study imposes some severe restrictions on the field equations as well.

Bijan Saha

2014-10-07T23:59:59.000Z

97

Ballistic dynamics of Dirac particles in electro-magnetic fields  

E-Print Network [OSTI]

Investigating properties of two-dimensional Dirac operators coupled to an electric and a magnetic field (perpendicular to the plane) requires in general unbounded (vector-) potentials. If the system has a certain symmetry, the fields can be described by one-dimensional potentials $V$ and $A$. Assuming that $|A|<|V|$ outside some arbitrary large ball, we show that absolutely continuous states of the effective Dirac operators spread ballistically. These results are based on well-known methods in spectral dynamics together with certain new Hilbert-Schmidt bounds. We use Lorentz boosts to derive these new estimates.

Josef Mehringer; Edgardo Stockmeyer

2014-11-21T23:59:59.000Z

98

Continuum resonance induced electromagnetic torque by a rotating plasma response to static resonant magnetic perturbation field  

SciTech Connect (OSTI)

A numerical study is carried out, based on a simple toroidal tokamak equilibrium, to demonstrate the radial re-distribution of the electromagnetic torque density, as a result of a rotating resistive plasma (linear) response to a static resonant magnetic perturbation field. The computed electromagnetic torque peaks at several radial locations even in the presence of a single rational surface, due to resonances between the rotating response, in the plasma frame, and both Alfven and sound continuum waves. These peaks tend to merge together to form a rather global torque distribution, when the plasma resistivity is large. The continuum resonance induced net electromagnetic torque remains finite even in the limit of an ideal plasma.

Liu Yueqiang; Connor, J. W.; Cowley, S. C.; Ham, C. J.; Hastie, R. J.; Hender, T. C. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

2012-10-15T23:59:59.000Z

99

Effects of Electromagnetic Field on the Dynamics of Bianchi type $VI_0$ Universe with Anisotropic Dark Energy  

E-Print Network [OSTI]

Spatially homogeneous and anisotropic Bianchi type $VI_0$ cosmological models with cosmological constant are investigated in the presence of anisotropic dark energy. We examine the effects of electromagnetic field on the dynamics of the universe and anisotropic behavior of dark energy. The law of variation of the mean Hubble parameter is used to find exact solutions of the Einstein field equations. We find that electromagnetic field promotes anisotropic behavior of dark energy which becomes isotropic for future evolution. It is concluded that the isotropic behavior of the universe model is seen even in the presence of electromagnetic field and anisotropic fluid.

M. Sharif; M. Zubair

2010-08-04T23:59:59.000Z

100

Electromagnetically superconducting phase of QCD vacuum induced by strong magnetic field  

SciTech Connect (OSTI)

In this talk we discuss our recent suggestion that the QCD vacuum in a sufficiently strong magnetic field (stronger than 10{sup 16} Tesla) may undergo a spontaneous transition to an electromagnetically superconducting state. The possible superconducting state is anisotropic (the vacuum exhibits superconductivity only along the axis of the uniform magnetic field) and inhomogeneous (in the transverse directions the vacuum structure shares similarity with the Abrikosov lattice of an ordinary type-II superconductor). The electromagnetic superconductivity of the QCD vacuum is suggested to occur due to emergence of specific quark-antiquark condensates which carry quantum numbers of electrically charged rho mesons. A Lorentz-covariant generalization of the London transport equations for the magnetic-field-induced superconductivity is given.

Chernodub, M. N. [CNRS, Laboratoire de Mathematiques et Physique Theorique, Universite Francois-Rabelais Tours, Federation Denis Poisson, Parc de Grandmont, 37200 Tours (France); Department of Physics and Astronomy, University of Gent, Krijgslaan 281, S9, B-9000 Gent (Belgium)

2011-05-23T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Electromagnetic Theory 1 /56 Electromagnetic Theory  

E-Print Network [OSTI]

Electromagnetic Theory 1 /56 Electromagnetic Theory Summary: · Maxwell's equations · EM Potentials · Equations of motion of particles in electromagnetic fields · Green's functions · Lienard-Weichert potentials · Spectral distribution of electromagnetic energy from an arbitrarily moving charge #12;Electromagnetic

Bicknell, Geoff

102

Frame Indifferent Formulation of Maxwell's Elastic Fluid and the Rational Continuum Mechanics of the Electromagnetic Field  

E-Print Network [OSTI]

We show that the linearized equations of the incompressible elastic medium admit a `Maxwell form' in which the shear component of the stress vector plays the role of the electric field, and the vorticity plays the role of the magnetic field. Conversely, the set of dynamic Maxwell equations are strict mathematical corollaries from the governing equations of the incompressible elastic medium. This suggests that the nature of `electromagnetic field' may actually be related to an elastic continuous medium. The analogy is complete if the medium is assumed to behave as fluid in shear motions, while it may still behave as elastic solid under compressional motions. Then the governing equations of the elastic fluid are re-derived in the Eulerian frame by replacing the partial time derivatives by the properly invariant (frame indifferent) time rates. The `Maxwell from' of the frame indifferent formulation gives the frame indifferent system that is to replace the Maxwell system. This new system comprises terms already present in the classical Maxwell equations, alongside terms that are the progenitors of the Biot--Savart, Oersted--Ampere's, and Lorentz--force laws. Thus a frame indifferent (truly covariant) formulation of electromagnetism is achieved from a single postulate that the electromagnetic field is a kind of elastic (partly liquid partly solid) continuum.

Christo I. Christov

2011-03-06T23:59:59.000Z

103

Effects of Electromagnetic Field on The Collapse and Expansion of Anisotropic Gravitating Source  

E-Print Network [OSTI]

This paper is devoted to study the effects of electromagnetic on the collapse and expansion of anisotropic gravitating source. For this purpose, we have evaluated the generating solutions of Einstein-Maxwell field equations with spherically symmetric anisotropic gravitating source. We found that a single function generates the various anisotropic solutions. In this case every generating function involves an arbitrary function of time which can be chosen to fit several astrophysical time profiles. Two physical phenomenon occur, one is gravitational collapse and other is the cosmological expanding solution. In both cases electromagnetic field effects the anisotropy of the model. For collapse the anisotropy is increased while for expansion it deceases from maximum value to finite positive value. In case of collaps there exits two horizons like in case of Reissner-Nordstr$\\ddot{o}$m metric.

G. Abbas

2014-05-27T23:59:59.000Z

104

Screening of electromagnetic field fluctuations by s--wave and d--wave superconductors  

E-Print Network [OSTI]

We investigate theoretically the shielding of the electromagnetic field fluctuations by s-wave and d-wave superconductors within the framework of macroscopic quantum electrodynamics. The spin flip lifetime is evaluated above a niobium and a bismuth strontium calcium copper oxide (BSCCO) surface, and the screening effect is studied as a function of the thickness of the superconducting layer. Further, we study the different temperature dependence of the atomic spin relaxation above the two superconductors.

Rachele Fermani; Stefan Scheel

2010-01-04T23:59:59.000Z

105

Nonlinear phenomena of generation of longitudinal electric current by transversal electromagnetic field in plasmas  

E-Print Network [OSTI]

The analysis of nonlinear interaction of transversal electromagnetic field with collisionless plasma is carried out. Formulas for calculation electric current in collisionless plasma with arbitrary degree of degeneration of electronic gas are deduced. It has appeared, that the nonlinearity account leads to occurrence of the longitudinal electric current directed along a wave vector. This second current is orthogonal to the known transversal current, received at the classical linear analysis.

Latyshev, A V

2015-01-01T23:59:59.000Z

106

Effects of Electromagnetic Field on the Dynamical Instability of Cylindrical Collapse  

E-Print Network [OSTI]

The objective of this paper is to discuss the dynamical instability in the context of Newtonian and post Newtonian regimes. For this purpose, we consider non-viscous heat conducting charged isotropic fluid as a collapsing matter with cylindrical symmetry. Darmois junction conditions are formulated. The perturbation scheme is applied to investigate the influence of dissipation and electromagnetic field on the dynamical instability. We conclude that the adiabatic index $\\Gamma$ has smaller value for such a fluid in cylindrically symmetric than isotropic sphere.

M. Sharif; M. Azam

2012-03-16T23:59:59.000Z

107

Laboratory Studies of the Short-term Responses of Freshwater Fish to Electromagnetic Fields  

SciTech Connect (OSTI)

Hydrokinetic energy technologies are being proposed as an environmentally preferred means of generating electricity from river and tidal currents. Among the potential issues that must be investigated in order to resolve environmental concerns are the effects on aquatic organisms of electromagnetic fields created by underwater generators and transmission cables. The behavioral responses of common freshwater fishes to static and variable electromagnetic fields (EMF) that may be emitted by hydrokinetic projects were evaluated in laboratory experiments. Various fish species were exposed to either static (DC) EMF fields created by a permanent bar magnet or variable (AC) EMF fields created by a switched electromagnet for 48 h, fish locations were recorded with a digital imaging system, and changes in activity level and distribution relative to the magnet position were quantified at 5-min intervals. Experiments with fathead minnows, redear sunfish, striped bass, lake sturgeon, and channel catfish produced mixed results. Except for fathead minnows there was no effect on activity level. Only redear sunfish and channel catfish exhibited a change in distribution relative to the position of the magnet with an apparent attraction to the EMF source. In separate experiments, rapid behavioral responses of paddlefish and lake sturgeon to onset of the AC field were recorded with high-speed video. Paddlefish did not react to a variable, 60-Hz magnetic field like that which would be emitted by an AC generator or cable, but lake sturgeon consistently responded to the variable, AC-generated magnetic field with a variety of altered swimming behaviors. These results will be useful for determining under what circumstances cables or generators need to be positioned to minimize interactions with sensitive species.

Bevelhimer, Mark S [ORNL; Cada, Glenn F [ORNL; Fortner, Allison M [ORNL; Schweizer, Peter E [ORNL; Riemer, Kristina P [ORNL

2013-01-01T23:59:59.000Z

108

Fundamental physics on natures of the macroscopic vacuum under high intense electromagnetic fields with accelerators  

E-Print Network [OSTI]

High intense electromagnetic fields can be unique probes to study natures of macroscopic vacua by themselves. Combining accelerators with the intense field can provide more fruitful probes which can neither be achieved by only intense fields nor only high energy accelerators. We will overview the natures of vacua which can be accessible via intense laser-laser and intense laser-electron interactions. In the case of the laser-laser interaction, we propose how to observe nonlinear QED effects and effects of new fields like light scalar and pseudo scalar fields which may contribute to a macroscopic nature of our universe such as dark energy. In the case of the laser-electron interaction, in addition to nonlinear QED effects, we can further discuss the nature of accelerating field in the vacuum where we can access physics related with event horizons such as Hawking-Unruh radiations. We will introduce a recent experimental trial to search for this kind of odd radiations.

Kensuke Homma

2009-11-30T23:59:59.000Z

109

Development of an international standard for electromagnetic interference (EMI)/radio frequency interference (RFI)  

SciTech Connect (OSTI)

This paper covers the development of an international standard that establishes the requirements for electromagnetic compatibility testing of instrumentation and control equipment supplied for use in systems important to safety at nuclear power plants. The standard lists the applicable IEC standards (principally the IEC 61000 series) which define the general test methods, and provides the necessary application-specific parameters and criteria to ensure that nuclear safety requirements are met. This standard was prepared with the leadership by the Russian National Committee representatives to the International Electrotechnical Commission (IEC). (authors)

Sarylov, V. [EMC Test Center, NUIT, FSUE RIPT, Moscow (Russian Federation); Shumov, S. [FSUE SEC SNIIP, Moscow (Russian Federation); Quinn, E. [ANS, Dana Point, CA (United States)

2006-07-01T23:59:59.000Z

110

Magneto-optic and electro-optic effects in electromagnetic and gravitational fields  

E-Print Network [OSTI]

The magneto-optic effects and electro-optic effects are the essential optic effects, although their theoretical explanations are not unified in the classical electromagnetic theory. Describing with the algebra of octonions, the electromagnetic theory can derive the magneto-optic effects and electro-optic effects from the same one force definition in the paper. As well as the magneto-optic effect is deduced from the known force term, the electro-optic effect is from the new force term in the octonion space. This description method is different to that in the quantum theory as well as the index ellipsoid approach for the electro-optic effect. One more significant inference is that the gravitational field has an impact on the rotation of linearly polarized light, and then results in the similar birefringence for the transmitted light in the cosmic matter.

Zi-Hua Weng

2010-11-26T23:59:59.000Z

111

Non-Markovian master equation for a system of Fermions interacting with an electromagnetic field  

SciTech Connect (OSTI)

For a system of charged Fermions interacting with an electromagnetic field, we derive a non-Markovian master equation in the second-order approximation of the weak dissipative coupling. A complex dissipative environment including Fermions, Bosons and the free electromagnetic field is taken into account. Besides the well-known Markovian term of Lindblad's form, that describes the decay of the system by correlated transitions of the system and environment particles, this equation includes new Markovian and non-Markovian terms proceeding from the fluctuations of the self-consistent field of the environment. These terms describe fluctuations of the energy levels, transitions among these levels stimulated by the fluctuations of the self-consistent field of the environment, and the influence of the time-evolution of the environment on the system dynamics. We derive a complementary master equation describing the environment dynamics correlated with the dynamics of the system. As an application, we obtain non-Markovian Maxwell-Bloch equations and calculate the absorption spectrum of a field propagation mode transversing an array of two-level quantum dots.

Stefanescu, Eliade [Center of Advanced Studies in Physics at the Institute of Mathematics Simion Stoilow of the Romanian Academy, 13 Calea 13 Septembrie, 050711 Bucharest S5 (Romania); Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Academy of Romanian Scientists, 54 Splaiul Independentei, 050094 Bucharest (Romania)], E-mail: eliadestefanescu@yahoo.fr; Scheid, Werner; Sandulescu, Aurel [Center of Advanced Studies in Physics at the Institute of Mathematics Simion Stoilow of the Romanian Academy, 13 Calea 13 Septembrie, 050711 Bucharest S5 (Romania); Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Academy of Romanian Scientists, 54 Splaiul Independentei, 050094 Bucharest (Romania)

2008-05-15T23:59:59.000Z

112

Electromagnetic quasinormal modes of D-dimensional black holes II  

E-Print Network [OSTI]

By using the sixth order WKB approximation we calculate for an electromagnetic field propagating in D-dimensional Schwarzschild and Schwarzschild de Sitter black holes its quasinormal frequencies for the fundamental mode and first overtones. We study the dependence of these QN frequencies on the value of the cosmological constant and the spacetime dimension. We also compare with the known results for the gravitational perturbations propagating in the same background. Moreover we exactly compute the QN frequencies of the electromagnetic field propagating in D-dimensional massless topological black hole and for charged D-dimensional Nariai spacetime we exactly calculate the QN frequencies of the coupled electromagnetic and gravitational perturbations.

A. López-Ortega

2007-06-20T23:59:59.000Z

113

Low-frequency absorption cross section of the electromagnetic waves for the extreme Reissner-Nordstrom black holes in higher dimensions  

E-Print Network [OSTI]

We investigate the low-frequency absorption cross section of the electromagnetic waves for the extreme Reissner-Nordstrom black holes in higher dimensions. We first construct the exact solutions to the relevant wave equations in the zero-frequency limit. In most cases it is possible to use these solutions to find the transmission coefficients of partial waves in the low-frequency limit. We use these transmission coefficients to calculate the low-frequency absorption cross section in five and six spacetime dimensions. We find that this cross section is dominated by the modes with l=2 in the spherical-harmonic expansion rather than those with l=1, as might have been expected, because of the mixing between the electromagnetic and gravitational waves. We also find an upper limit for the low-frequency absorption cross section in dimensions higher than six.

Luis C. B. Crispino; Atsushi Higuchi; George E. A. Matsas

2010-12-16T23:59:59.000Z

114

Second Quantized Scalar QED in Homogeneous Time-Dependent Electromagnetic Fields  

E-Print Network [OSTI]

We formulate the second quantization of a charged scalar field in homogeneous, time-dependent electromagnetic fields, in which the Hamiltonian is an infinite system of decoupled, time-dependent oscillators for electric fields, but it is another infinite system of coupled, time-dependent oscillators for magnetic fields. We then employ the quantum invariant method to find various quantum states for the charged field. For time-dependent electric fields, a pair of quantum invariant operators for each oscillator with the given momentum plays the role of the time-dependent annihilation and the creation operators, constructs the exact quantum states, and gives the vacuum persistence amplitude as well as the pair-production rate. We also find the quantum invariants for the coupled oscillators for the charged field in time-dependent magnetic fields and advance a perturbation method when the magnetic fields change adiabatically. Finally, the quantum state and the pair production are discussed when a time-dependent electric field is present in parallel to the magnetic field.

Sang Pyo Kim

2014-09-04T23:59:59.000Z

115

Radio frequency accelerating cavity having slotted irises for damping certain electromagnetic modes  

DOE Patents [OSTI]

An accelerating cavity is disclosed having one or more iris structures mounted therein for strongly damping unwanted frequencies that are generated in the cavity by bunches of particles in a particle beam that is accelerated through the cavity during its operation. Each of the iris structures is characterized by containing a plurality of radial slots therein that extend from the central aperture through the iris member to the perimeter thereof. The outer end of each of the radial slots includes an enlarged portion that is effective to prevent undesired frequencies from being reflected back into the center aperture of the iris member. Waveguide means connect the outer ends of the radial slots to frequency damping means or to a dump or dumps. 17 figures.

Palmer, R.B.

1991-05-21T23:59:59.000Z

116

Radio frequency accelerating cavity having slotted irises for damping certain electromagnetic modes  

DOE Patents [OSTI]

An accelerating cavity having one or more iris structures mounted therein for strongly damping unwanted frequencies that are generated in the cavity by bunches of particles in a particle beam that is accelerated through the cavity during its operation. Each of the iris structures is characterized by containing a plurality of radial slots therein that extend from the central aperture through the iris member to the perimeter thereof. The outer end of each of the radial slots includes an enlarged portion that is effective to prevent undesired frequencies from being reflected back into the center aperture of the iris member. Waveguide means connect the outer ends of the radial slots to frequency damping means or to a dump or dumps.

Palmer, Robert B. (Shoreham, NY)

1991-01-01T23:59:59.000Z

117

In situ electromagnetic field diagnostics with an electron plasma in a Penning-Malmberg trap  

E-Print Network [OSTI]

We demonstrate a novel detection method for the cyclotron resonance frequency of an electron plasma in a Penning-Malmberg trap. With this technique, the electron plasma is used as an in situ diagnostic tool for measurement of the static magnetic field and the microwave electric field in the trap. The cyclotron motion of the electron plasma is excited by microwave radiation and the temperature change of the plasma is measured non-destructively by monitoring the plasma's quadrupole mode frequency. The spatially-resolved microwave electric field strength can be inferred from the plasma temperature change and the magnetic field is found through the cyclotron resonance frequency. These measurements were used extensively in the recently reported demonstration of resonant quantum interactions with antihydrogen.

C. Amole; M. D. Ashkezari; M. Baquero-Ruiz; W. Bertsche; E. Butler; A. Capra; C. L. Cesar; M. Charlton; A. Deller; N. Evetts; S. Eriksson; J. Fajans; T. Friesen; M. C. Fujiwara; D. R. Gill; A. Gutierrez; J. S. Hangst; W. N. Hardy; M. E. Hayden; C. A. Isaac; S. Jonsell; L. Kurchaninov; A. Little; N. Madsen; J. T. K. McKenna; S. Menary; S. C. Napoli; K. Olchanski; A. Olin; P. Pusa; C. Ø. Rasmussen; F. Robicheaux; E. Sarid; D. M. Silveira; C. So; S. Stracka; T. Tharp; R. I. Thompson; D. P. van der Werf; J. S. Wurtele

2014-05-04T23:59:59.000Z

118

In situ electromagnetic field diagnostics with an electron plasma in a Penning-Malmberg trap  

E-Print Network [OSTI]

We demonstrate a novel detection method for the cyclotron resonance frequency of an electron plasma in a Penning-Malmberg trap. With this technique, the electron plasma is used as an in situ diagnostic tool for measurement of the static magnetic field and the microwave electric field in the trap. The cyclotron motion of the electron plasma is excited by microwave radiation and the temperature change of the plasma is measured non-destructively by monitoring the plasma's quadrupole mode frequency. The spatially-resolved microwave electric field strength can be inferred from the plasma temperature change and the magnetic field is found through the cyclotron resonance frequency. These measurements were used extensively in the recently reported demonstration of resonant quantum interactions with antihydrogen.

Amole, C; Baquero-Ruiz, M; Bertsche, W; Butler, E; Capra, A; Cesar, C L; Charlton, M; Deller, A; Evetts, N; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Isaac, C A; Jonsell, S; Kurchaninov, L; Little, A; Madsen, N; McKenna, J T K; Menary, S; Napoli, S C; Olchanski, K; Olin, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sarid, E; Silveira, D M; So, C; Stracka, S; Tharp, T; Thompson, R I; van der Werf, D P; Wurtele, J S

2014-01-01T23:59:59.000Z

119

Effects of Electromagnetic Field on Energy Density Inhomogeneity in Self-Gravitating Fluids  

E-Print Network [OSTI]

This paper is devoted to study the effects of electromagnetic field on the energy density inhomogeneity in the relativistic self-gravitating fluids for spherically symmetric spacetime. Two important equations of the Weyl tensor are formulated which help to analyze the energy density inhomogeneity in this scenario. We investigate two types of fluids, i.e., non-dissipative and dissipative. The non-dissipative fluid further includes dust, locally isotropic, and locally anisotropic charged fluids. We explore the effects of different factors on energy density inhomogeneity in all these cases, in particular, the effect of charge.

M. Sharif; Neelum Bashir

2012-09-25T23:59:59.000Z

120

Particle dynamics and deviation effects in the field of a strong electromagnetic wave  

E-Print Network [OSTI]

Some strong field effects on test particle motion associated with the propagation of a plane electromagnetic wave in the exact theory of general relativity are investigated. Two different profiles of the associated radiation flux are considered in comparison, corresponding to either constant or oscillating electric and magnetic fields with respect to a natural family of observers. These are the most common situations to be experimentally explored, and have a well known counterpart in the flat spacetime limit. The resulting line elements are determined by a single metric function, which turns out to be expressed in terms of standard trigonometric functions in the case of a constant radiation flux, and in terms of special functions in the case of oscillating flux, leading to different features of test particle motion. The world line deviation between both uncharged and charged particles on different spacetime trajectories due to the combined effect of gravitational and electromagnetic forces is studied. The interaction of charged particles with the background radiation field is also discussed through a general relativistic description of the inverse Compton effect. Motion as well as deviation effects on particles endowed with spin are studied too. Special situations may occur in which the direction of the spin vector change during the interaction, leading to obsevables effects like spin-flip.

Donato Bini; Andrea Geralico; Maria Haney; Antonello Ortolan

2014-08-23T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Retarded Interaction of Electromagnetic field and Symmetry Violation of Time Reversal in Non-linear Optics  

E-Print Network [OSTI]

Based on Document (1), by considering the retarded interaction of radiation fields, the third order transition probabilities of stimulated radiations and absorptions of light are calculated. The revised formulas of nonlinear polarizations are provided. The results show that that the general processes of non-linear optics violate time reversal symmetry. The phenomena of non-linear optics violating time reversal symmetry just as sum frequency, double frequency, different frequencies, double stable states, self-focusing and self-defocusing, echo phenomena, as well as optical self-transparence and self absorptions and so on are analyzed.

Mei Xiaochun

2008-04-19T23:59:59.000Z

122

Spin oscillations of relativistic fermions in the field of a traveling circularly polarized electromagnetic wave and a constant magnetic field  

E-Print Network [OSTI]

The Dirac equation, in the field of a traveling circularly polarized electromagnetic wave and a constant magnetic field, has singular solutions, corresponding the expansion of energy in vicinity of some singular point. These solutions described relativistic fermions. States relating to these solutions are not stationary. The temporal change of average energy, momentum and spin for single and mixed states is studied in the paper. A distinctive feature of the states is the disappearance of the longitudinal component of the average spin. Another feature is the equivalence of the condition of fermion minimal energy and the classical condition of the magnetic resonance. Finding such solutions assumes the use of a transformation for rotating and co-moving frames of references. Comparison studies of solutions obtained with the Galilean and non-Galilean transformation shown that some parameters of the non-Galilean transformation may be measured in high-energy physics.

Boris V. Gisin

2014-05-13T23:59:59.000Z

123

Electromagnetic partner of the gravitational signal during accretion onto black holes  

E-Print Network [OSTI]

We investigate the generation of electromagnetic and gravitational radiation in the vicinity of a perturbed Schwarzschild black hole. The gravitational perturbations and the electromagnetic field are studied by solving the Teukolsky master equation with sources, which we take to be locally charged, radially infalling, matter. Our results show that, in addition to the gravitational wave generated as the matter falls into the black hole, there is also a burst of electromagnetic radiation. This electromagnetic field has a characteristic set of quasinormal frequencies, and the gravitational radiation has the quasinormal frequencies of a Schwarzschild black hole. This scenario allows us to compare the gravitational and electromagnetic signals that are generated by a common source.

Juan Carlos Degollado; Victor Gualajara; Claudia Moreno; Darío Núñez

2014-10-21T23:59:59.000Z

124

Low-cost electromagnetic tagging : design and implementation  

E-Print Network [OSTI]

Several implementations of chipless RFID (Radio Frequency Identification) tags are presented and discussed as low-cost alternatives to chip-based RFID tags and sensors. An overview of present-day near-field electromagnetic ...

Fletcher, Richard R. (Richard Ribon)

2002-01-01T23:59:59.000Z

125

An electromagnetic black hole made of metamaterials  

E-Print Network [OSTI]

Traditionally, a black hole is a region of space with huge gravitational field in the means of general relativity, which absorbs everything hitting it including the light. In general relativity, the presence of matter-energy densities results in the motion of matter propagating in a curved spacetime1, which is similar to the electromagnetic-wave propagation in a curved space and in an inhomogeneous metamaterial2. Hence one can simulate the black hole using electromagnetic fields and metamaterials. In a recent theoretical work, an optical black hole has been proposed based on metamaterials, in which the numerical simulations showed a highly efficient light absorption3. Here we report the first experimental demonstration of electromagnetic black hole in the microwave frequencies. The proposed black hole is composed of non-resonant and resonant metamaterial structures, which can absorb electromagnetic waves efficiently coming from all directions due to the local control of electromagnetic fields. Hence the elect...

Cheng, Qiang

2009-01-01T23:59:59.000Z

126

Gauge Freedom and Relativity: A Unified Treatment of Electromagnetism, Gravity and the Dirac Field  

E-Print Network [OSTI]

The geometric properties of General Relativity are reconsidered as a particular nonlinear interaction of fields on a flat background where the perceived geometry and coordinates are "physical" entities that are interpolated by a patchwork of observable bodies with a nonintuitive relationship to the underlying fields. This more general notion of gauge in physics opens an important door to put all fields on a similar standing but requires a careful reconsideration of tensors in physics and the conventional wisdom surrounding them. The meaning of the flat background and the induced conserved quantities are discussed and contrasted with the "observable" positive definite energy and probability density in terms of the induced physical coordinates. In this context, the Dirac matrices are promoted to dynamic proto-gravity fields and the keeper of "physical metric" information. Independent sister fields to the wavefunctions are utilized in a bilinear rather than a quadratic lagrangian in these fields. This construction greatly enlarges the gauge group so that now proving causal evolution, relative to the physical metric, for the gauge invariant functions of the fields requires both the stress-energy conservation and probability current conservation laws. Through a Higgs-like coupling term the proto-gravity fields generate a well defined physical metric structure and gives the usual distinguishing of gravity from electromagnetism at low energies relative to the Higgs-like coupling. The flat background induces a full set of conservation laws but results in the need to distinguish these quantities from those observed by recording devices and observers constructed from the fields.

Clifford E. Chafin

2015-01-18T23:59:59.000Z

127

Source-free electromagnetism's canonical fields reveal the free-photon Schroedinger equation  

E-Print Network [OSTI]

Classical equations of motion that are first-order in time and conserve energy can only be quantized after their variables have been transformed to canonical ones, i.e., variables in which the energy is the system's Hamiltonian. The source-free version of Maxwell's equations is purely dynamical, first-order in time and has a well-defined nonnegative conserved field energy, but is decidedly noncanonical, an issue that has attracted little attention. The opposite parities of the electric and magnetic fields and consequent curl operations that typify Maxwell's equations are especially at odds with their being canonical fields. Transformation of the magnetic field into the transverse part of the vector potential helps but is not sufficient; further simple nonnegative symmetric integral transforms, which commute with all differential operators, are needed for both fields; such transforms also supplant the curls in the equations of motion. The canonical replacements of the source-free electromagnetic fields remain transverse-vector fields, but are more diffuse than their predecessors. Combined as the real and imaginary parts of a complex field, the canonical fields prove to be the transverse-vector wave function of a time-dependent Schroedinger equation whose Hamiltonian operator is the quantization of the free photon's square-root relativistic energy. Thus proper quantization of the source-free Maxwell equations is identical to second quantization of free photons that have normal square-root energy. There is no physical reason why first and second quantization of any relativistic free particle ought not to proceed in precise parallel, utilizing the square-root Hamiltonian operator. This natural procedure leaves no role for the completely artificial Klein-Gordon and Dirac equations, as accords with their grossly unphysical properties.

Steven Kenneth Kauffmann

2010-11-29T23:59:59.000Z

128

Electromagnetic quasinormal modes of an asymptotically Lifshitz black hole  

E-Print Network [OSTI]

Motivated by the recent interest in the study of the spacetimes that are asymptotically Lifshitz and in order to extend some previous results, we calculate exactly the quasinormal frequencies of the electromagnetic field in a D-dimensional asymptotically Lifshitz black hole. Based on the values obtained for the quasinormal frequencies we discuss the classical stability of the quasinormal modes. We also study whether the electromagnetic field possesses unstable modes in the D-dimensional Lifshitz spacetime.

A. Lopez-Ortega

2014-06-01T23:59:59.000Z

129

Nonlinear Electrodynamics: Alternative Field Theory for Featuring Photon Propagation Over Weak Background Electromagnetic Fields and what Earth Receivers Read off Radio Signals from Interplanetary Spacecraft Transponders  

E-Print Network [OSTI]

A few observational and/or experimental results have dramatically pushed forward the research program on gravity as those from the radio-metric Doppler tracking received from the Pioneer 10 and 11 spacecrafts when the space vehicles were at heliocentric distances between 20 and 70 Astronomical Units (AU). These data have conclusively demonstrated the presence of an anomalous, tiny and blue-shifted frequency drift that changes smoothly at a rate of $ \\sim 6 \\times 10^{-9}$ Hz s$^{-1}$. Those signals, if interpreted as a gravitational pull of the Sun on each Pioneer vehicle, translates into a deceleration of $a_P = (8.74\\pm 1.33) \\times 10^{-10}$ m s$^{-2}$. This Sunward acceleration appears to be a violation of Newton's inverse-square law of gravitation, and is referred to as the Pioneer anomaly, the nature of which remains still elusive to unveil. Within the theoretical framework of nonlinear electrodynamics (NLED) in what follows we will address this astrodynamics puzzle, which over the last fifteen years has challenged in a fundamental basis our understanding of gravitational physics. To this goal we will first, and briefly, review the history of the Pioneers 10 and 11 missions. Then a synopsis of currently available Lagrangian formulations of NLED is given. And finally, we present our solution of this enigma by invoking a special class of NLED theories featuring a proper description of electromagnetic phenomena taking place in environments where the strength of the (electro)magnetic fields in the background is decidedly low.

Herman J. Mosquera Cuesta

2011-05-13T23:59:59.000Z

130

Generation of the longitudinal current by the transversal electromagnetic field in classical and quantum plasmas  

E-Print Network [OSTI]

From Vlasov kinetic equation for collisionless plasmas distribution function in square-law approximation on size of electromagnetic field is received. Formulas for calculation electric current at any temperature (any degree of degeneration of electronic gas) are deduced. The case of small values of the wave numbers is considered. It is shown, that the nonlinearity account leads to occurrence the longitudinal electric current directed along a wave vector. This longitudinal current orthogonal to known transversal classical current, received at the linear analysis. From the kinetic equation with Wigner integral for collisionless quantum plasma distribution function is received in square-law on vector potential approximation. Formulas for calculation electric current at any temperature are deduced. The case of small values of wave number is considered. It is shown, that size of a longitudinal current at small values of wave number and for classical plasma and for quantum plasma coincide. Graphic comparison of dim...

Latyshev, A V

2015-01-01T23:59:59.000Z

131

On the Casimir energy of the electromagnetic field in the dispersive and absorptive medium  

E-Print Network [OSTI]

The microscopic theory of the Casimir effect in the dielectric is studied in the framework when absorption is realized via a reservoir modeled by a set of oscillators with continuously distributed frquencies with the aim to see if the effects depend on the form of interaction with the reservoir. A simple case of the one-dimensional dielectric between two metallic plates is considered. Two possible models are investigated, the direct interaction of the electromagnetic field with the reservoir and indirect interaction via an intermediate oscillator imitating the atom. It is found that with the same dielectric constant the Casimir effect is different in these two cases, which implies that in the second model it cannot be entirely expressed via the dielectric constant as in the well-known Lifshitz formula.

M. A. Braun

2014-02-16T23:59:59.000Z

132

Kinetic equilibria of relativistic collisionless plasmas in the presence of non-stationary electromagnetic fields  

SciTech Connect (OSTI)

The kinetic description of relativistic plasmas in the presence of time-varying and spatially non-uniform electromagnetic (EM) fields is a fundamental theoretical issue both in astrophysics and plasma physics. This refers, in particular, to the treatment of collisionless and strongly-magnetized plasmas in the presence of intense radiation sources. In this paper, the problem is investigated in the framework of a covariant gyrokinetic treatment for Vlasov–Maxwell equilibria. The existence of a new class of kinetic equilibria is pointed out, which occur for spatially-symmetric systems. These equilibria are shown to exist in the presence of non-uniform background EM fields and curved space-time. In the non-relativistic limit, this feature permits the determination of kinetic equilibria even for plasmas in which particle energy is not conserved due to the occurrence of explicitly time-dependent EM fields. Finally, absolute stability criteria are established which apply in the case of infinitesimal symmetric perturbations that can be either externally or internally produced.

Cremaschini, Claudio, E-mail: claudiocremaschini@gmail.com; Stuchlík, Zden?k [Faculty of Philosophy and Science, Institute of Physics, Silesian University in Opava, Bezru?ovo nám.13, CZ-74601 Opava (Czech Republic)] [Faculty of Philosophy and Science, Institute of Physics, Silesian University in Opava, Bezru?ovo nám.13, CZ-74601 Opava (Czech Republic); Tessarotto, Massimo [Faculty of Philosophy and Science, Institute of Physics, Silesian University in Opava, Bezru?ovo nám.13, CZ-74601 Opava (Czech Republic) [Faculty of Philosophy and Science, Institute of Physics, Silesian University in Opava, Bezru?ovo nám.13, CZ-74601 Opava (Czech Republic); Department of Mathematics and Geosciences, University of Trieste, Via Valerio 12, 34127 Trieste (Italy)

2014-03-15T23:59:59.000Z

133

A Topological Structure in the Set of Classical Free Radiation Electromagnetic Fields  

E-Print Network [OSTI]

The aim of this work is to proceed with the development of a model of topological electromagnetism in empty space, proposed by one of us some time ago and based on the existence of a topological structure associated with the radiation fields in standard Maxwell's theory. This structure consists in pairs of complex scalar fields, say $\\phi$ and $\\theta$, that can be interpreted as maps $\\phi,\\theta: S^3\\mapsto S^2$, the level lines of which are orthogonal to one another, where $S^3$ is the compactified physical 3-space $R^3$, with only one point at infinity, and $S^2$ is the 2-sphere identified with the complete complex plane. These maps were discovered and studied in 1931 by the German mathematician H. Hopf, who showed that the set of all of them can be ordered in homotopy classes, labeled by the so called Hopf index, equal to $\\gamma=\\pm 1,\\,\\pm 2,\\,\\cdots ,\\, \\pm k,...$ but without $\\gamma=0$. In the model presented here and at the level of the scalars $\\phi$ and $\\theta$, the equations of motion are highly nonlinear; however there is a transformation of variables that converts exactly these equations (not by truncation!) into the linear Maxwell's ones for the magnetic and electric fields $\\B$ and $\\E$.

A. F. Ranada; A. Tiemblo

2014-07-29T23:59:59.000Z

134

Electromagnetic fields induced by a point source in a uniaxial multiferroic full-space, half-space, and bimaterial space  

E-Print Network [OSTI]

Electromagnetic fields induced by a point source in a uniaxial multiferroic full-space, half-space, and bimaterial space X. Wang and E. Pana) Department of Civil Engineering and Department of Applied Mathematics multiferroic full-space, half-space, and bimaterial space. While for the bimaterial space case the interface

Pan, Ernie

135

E-Print Network 3.0 - ambient electromagnetic fields Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Analysis Techniques Summary: & Technology Introduction Products fail electromagnetic interference (EMI) tests. This can be a disappointing... , and antenna. No single method...

136

E-Print Network 3.0 - amplitude-modulated electromagnetic fields...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

; Engineering 8 Yerkes Summer Institute 2002 Before we begin our investigations into radio waves you should review the Summary: of the spectrum. Electromagnetic radiation...

137

Phase field method to optimize dielectric devices for electromagnetic wave propagation  

SciTech Connect (OSTI)

We discuss a phase field method for shape optimization in the context of electromagnetic wave propagation. The proposed method has the same functional capabilities as the level set method for shape optimization. The first advantage of the method is the simplicity of computation, since extra operations such as re-initialization of functions are not required. The second is compatibility with the topology optimization method due to the similar domain representation and the sensitivity analysis. Structural shapes are represented by the phase field function defined in the design domain, and this function is optimized by solving a time-dependent reaction diffusion equation. The artificial double-well potential function used in the equation is derived from sensitivity analysis. We study four types of 2D or 2.5D (axisymmetric) optimization problems. Two are the classical problems of photonic crystal design based on the Bloch theory and photonic crystal wave guide design, and two are the recent topics of designing dielectric left-handed metamaterials and dielectric ring resonators.

Takezawa, Akihiro, E-mail: akihiro@hiroshima-u.ac.jp; Kitamura, Mitsuru, E-mail: kitamura@naoe.hiroshima-u.ac.jp

2014-01-15T23:59:59.000Z

138

Electromagnetic quasinormal modes of D-dimensional black holes  

E-Print Network [OSTI]

Using the monodromy method we calculate the asymptotic quasinormal (QN) frequencies of an electromagnetic field moving in D-dimensional Schwarzschild and Schwarzschild de Sitter (SdS) black holes ($D\\geq 4$). For the D-dimensional Schwarzschild anti-de Sitter (SadS) black hole we also compute these frequencies with a similar method. Moreover, we calculate the electromagnetic normal modes of the D-dimensional anti-de Sitter (AdS) spacetime.

A. López-Ortega

2006-11-02T23:59:59.000Z

139

Numerical approximation of the Schrödinger equation with the electromagnetic field by the Hagedorn wave packets  

SciTech Connect (OSTI)

In this paper, we approximate the semi-classical Schrödinger equation in the presence of electromagnetic field by the Hagedorn wave packets approach. By operator splitting, the Hamiltonian is divided into the modified part and the residual part. The modified Hamiltonian, which is the main new idea of this paper, is chosen by the fact that Hagedorn wave packets are localized both in space and momentum so that a crucial correction term is added to the truncated Hamiltonian, and is treated by evolving the parameters associated with the Hagedorn wave packets. The residual part is treated by a Galerkin approximation. We prove that, with the modified Hamiltonian only, the Hagedorn wave packets dynamics give the asymptotic solution with error O(?{sup 1/2}), where ? is the scaled Planck constant. We also prove that, the Galerkin approximation for the residual Hamiltonian can reduce the approximation error to O(?{sup k/2}), where k depends on the number of Hagedorn wave packets added to the dynamics. This approach is easy to implement, and can be naturally extended to the multidimensional cases. Unlike the high order Gaussian beam method, in which the non-constant cut-off function is necessary and some extra error is introduced, the Hagedorn wave packets approach gives a practical way to improve accuracy even when ? is not very small.

Zhou, Zhennan, E-mail: zhou@math.wisc.edu

2014-09-01T23:59:59.000Z

140

Exactly solvable model of two three-dimensional harmonic oscillators interacting with the quantum electromagnetic field: The far-zone Casimir-Polder potential  

SciTech Connect (OSTI)

We consider two three-dimensional isotropic harmonic oscillators with the same frequency and interacting with the quantum electromagnetic field in the Coulomb gauge and within dipole approximation. Using a Bogoliubov-type transformation, we can obtain transformed operators such that the Hamiltonian of the system, when expressed in terms of these operators, assumes a diagonal form. We are also able to obtain an expression for the energy shift of the ground state, which is valid at all orders in the coupling constant. From this energy shift, the nonperturbative Casimir-Polder potential energy between the two oscillators can be obtained. When approximated to the fourth order in the electric charge, the well-known expression of the far zone Casimir-Polder potential in terms of the polarizabilities of the oscillators is recovered.

Ciccarello, F. [Dipartimento di Fisica e Tecnologie Relative dell'Universita degli Studi di Palermo and CNR-INFM, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Karpov, E. [International Solvay Institutes for Physics and Chemistry, Campus Plaine ULB, C.P. 231, Boulevard du Triomphe, B-1050, Brussels (Belgium) and Quantum Information and Communication (QUIC), CP 165/59, Ecole Polytechnique, Universite Libre de Bruxelles, 50 av. F. D. Roosevelt, B-1050 Brussels (Belgium); Passante, R. [Dipartimento di Scienze Fisiche ed Astronomiche dell'Universita degli Studi di Palermo and CNR-INFM, Via Archirafi 36, I-90123 Palermo (Italy)

2005-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Apparatus and method for enhanced chemical processing in high pressure and atmospheric plasmas produced by high frequency electromagnetic waves  

DOE Patents [OSTI]

An apparatus and method for creating high temperature plasmas for enhanced chemical processing of gaseous fluids, toxic chemicals, and the like, at a wide range of pressures, especially at atmospheric and high pressures includes an electro-magnetic resonator cavity, preferably a reentrant cavity, and a wave guiding structure which connects an electro-magnetic source to the cavity. The cavity includes an intake port and an exhaust port, each having apertures in the conductive walls of the cavity sufficient for the intake of the gaseous fluids and for the discharge of the processed gaseous fluids. The apertures are sufficiently small to prevent the leakage of the electro-magnetic radiation from the cavity. Gaseous fluid flowing from the direction of the electro-magnetic source through the guiding wave structure and into the cavity acts on the plasma to push it away from the guiding wave structure and the electro-magnetic source. The gaseous fluid flow confines the high temperature plasma inside the cavity and allows complete chemical processing of the gaseous fluids at a wide range of pressures.

Efthimion, Philip C. (Bedminister, NJ); Helfritch, Dennis J. (Flemington, NJ)

1989-11-28T23:59:59.000Z

142

Position-dependent photon operators in the quantization of the electromagnetic field in dielectrics at local thermal equilibrium  

E-Print Network [OSTI]

It has very recently been suggested that asymmetric coupling of electromagnetic fields to thermal reservoirs under nonequilibrium conditions can produce unexpected oscillatory behavior in the local photon statistics in layered structures. Better understanding of the predicted phenomena could enable useful applications related to thermometry, noise filtering, and enhancing optical interactions. In this work we briefly review the field quantization and study the local steady state temperature distributions in optical cavities formed of lossless and lossy media to show that also local field temperatures exhibit oscillations that depend on position as well as the photon energy.

Mikko Partanen; Teppo Häyrynen; Jani Oksanen; Jukka Tulkki

2014-12-02T23:59:59.000Z

143

On the frequency of oscillations in the pair plasma generated by a strong electric field  

E-Print Network [OSTI]

We study the frequency of the plasma oscillations of electron-positron pairs created by the vacuum polarization in an uniform electric field with strength E in the range 0.2 Ec plasma oscillation equation when E -> 0. Thereby, we focus our attention on its evolution in time studying how this oscillation frequency approaches the plasma frequency. The time-scale needed to approach to the plasma frequency and the power spectrum of these oscillations are computed. The characteristic frequency of the power spectrum is determined uniquely from the initial value of the electric field strength. The effects of plasma degeneracy and pair annihilation are discussed.

A. Benedetti; W. -B. Han; R. Ruffini; G. V. Vereshchagin

2011-02-21T23:59:59.000Z

144

Coherent quantum states of a relativistic particle in an electromagnetic plane wave and a parallel magnetic field  

SciTech Connect (OSTI)

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.

Colavita, E. [Colegio de Ciencia y Tecnología, Universidad Autónoma de la Ciudad de México, México, D.F., 09790 (Mexico)] [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)

2014-03-15T23:59:59.000Z

145

Duality and integrability: Electromagnetism, linearized gravity, and massless higher spin gauge fields as bi-Hamiltonian systems  

SciTech Connect (OSTI)

In the reduced phase space of electromagnetism, the generator of duality rotations in the usual Poisson bracket is shown to generate Maxwell's equations in a second, much simpler Poisson bracket. This gives rise to a hierarchy of bi-Hamiltonian evolution equations in the standard way. The result can be extended to linearized Yang-Mills theory, linearized gravity, and massless higher spin gauge fields.

Barnich, Glenn; Troessaert, Cedric [Physique Theorique et Mathematique, Universite Libre de Bruxelles and International Solvay Institutes, Campus Plaine C.P. 231, B-1050 Bruxelles (Belgium)

2009-04-15T23:59:59.000Z

146

Dimensional scaling treatment of stability of atomic anions induced by superintense, high-frequency laser fields  

E-Print Network [OSTI]

and often paradoxical electronic properties of atoms induced by high-frequency superintense radiation fields- lization of multiply charged anions of hydrogen10 and doubly charged anions of helium and lithium atoms.11 of molecular anions. II. LASER ATOM INTERACTION We consider a high-frequency monochromatic electric field

Kais, Sabre

147

Second and Fourth Harmonic Frequencies in Electric Field-Induced Liquid Crystal Reorientations  

E-Print Network [OSTI]

Second and Fourth Harmonic Frequencies in Electric Field-Induced Liquid Crystal Reorientations of Central Florida, Orlando, Florida, USA The second and fourth harmonics of low frequency electric field-optical modulation; liquid crystal; second and fourth harmonics 1. INTRODUCTION Nematic liquid crystal (LC) has been

Wu, Shin-Tson

148

Quasinormal frequencies of the Dirac field in the massless topological black hole  

E-Print Network [OSTI]

Motivated by the recent computations of the quasinormal frequencies of higher dimensional black holes we exactly calculate the quasinormal frequencies of the Dirac field propagating in D-dimensional (D > 4) massless topological black hole. From the exact values of the quasinormal frequencies for the fermion and boson fields we discuss whether the recently proposed bound on the relaxation time of a perturbed thermodynamical system is satisfied in D-dimensional massless topological black hole. Also we study the consequences of these results.

A. Lopez-Ortega

2010-06-25T23:59:59.000Z

149

Advanced methods for the computation of particle beam transport and the computation of electromagnetic fields and beam-cavity interactions  

SciTech Connect (OSTI)

The University of Maryland Dynamical Systems and Accelerator Theory Group carries out research in two broad areas: the computation of charged particle beam transport using Lie algebraic methods and advanced methods for the computation of electromagnetic fields and beam-cavity interactions. Important improvements in the state of the art are believed to be possible in both of these areas. In addition, applications of these methods are made to problems of current interest in accelerator physics including the theoretical performance of present and proposed high energy machines. The Lie algebraic method of computing and analyzing beam transport handles both linear and nonlinear beam elements. Tests show this method to be superior to the earlier matrix or numerical integration methods. It has wide application to many areas including accelerator physics, intense particle beams, ion microprobes, high resolution electron microscopy, and light optics. With regard to the area of electromagnetic fields and beam cavity interactions, work is carried out on the theory of beam breakup in single pulses. Work is also done on the analysis of the high behavior of longitudinal and transverse coupling impendances, including the examination of methods which may be used to measure these impedances. Finally, work is performed on the electromagnetic analysis of coupled cavities and on the coupling of cavities to waveguides.

Dragt, A.J.; Gluckstern, R.L.

1990-11-01T23:59:59.000Z

150

Electromagnetic Waves Propagation in 3D Plasma Configurations  

E-Print Network [OSTI]

Electromagnetic Waves Propagation in 3D Plasma Configurations Pavel Popovich, W. Anthony Cooper in a plasma strongly depends on the frequency, therefore the tools used for wave propagation studies are very that will allow for the calculation of the fields and energy deposition of a low-frequency wave propagating

151

Electromagnetic interference impact of the proposed emitters for the High Frequency Active Auroral Research Program (HAARP). Interim report  

SciTech Connect (OSTI)

The proposed HAARP emitters at the Gakona (Alaska) preferred site and at the Clear AFS (Alaska) alternative site are the Ionospheric Research Instrument (IRI), the Incoherent Scatter Radar (ISR), and the Vertical Incidence Sounder(VIS). The electromagnetic interference (EMI) impact of those emitters on receiving systems in the vicinity of the sites is estimated in this study. The results are intended for use as an input to the Air Force Environmental Impact Statement as part of the Environmental Impact Analysis Process.

Robertshaw, G.A.; Snyder, A.L.; Weiner, M.M.

1993-05-14T23:59:59.000Z

152

Electromagnetic Geometry  

E-Print Network [OSTI]

We show that Maxwell's electromagnetism can be mapped into the Born-Infeld theory in a curved space-time, which depends only on the electromagnetic field in a specific way. This map is valid for any value of the two lorentz invariants $F$ and $G$ confirming that we have included all possible solutions of Maxwell's equations. Our result seems to show that specifying the dynamics and the space-time structure of a given theory can be viewed merely as a choice of representation to describe the physical system.

M. Novello; F. T. Falciano; E. Goulart

2011-11-08T23:59:59.000Z

153

Quasinormal frequencies of the Dirac field in a D-dimensional Lifshitz black hole  

E-Print Network [OSTI]

In a D-dimensional Lifshitz black hole we calculate exactly the quasinormal frequencies of a test Dirac field in the massless and zero angular eigenvalue limits. These results are an extension of the previous calculations in which the quasinormal frequencies of the Dirac field are determined, but in four dimensions. We discuss the four-dimensional limit of our expressions for the quasinormal frequencies and compare with the previous results. We also determine whether the Dirac field has unstable modes in the D-dimensional Lifshitz spacetime.

A. Lopez-Ortega

2014-07-03T23:59:59.000Z

154

ADVANCED METHODS FOR THE COMPUTATION OF PARTICLE BEAM TRANSPORT AND THE COMPUTATION OF ELECTROMAGNETIC FIELDS AND MULTIPARTICLE PHENOMENA  

SciTech Connect (OSTI)

Since 1980, under the grant DEFG02-96ER40949, the Department of Energy has supported the educational and research work of the University of Maryland Dynamical Systems and Accelerator Theory (DSAT) Group. The primary focus of this educational/research group has been on the computation and analysis of charged-particle beam transport using Lie algebraic methods, and on advanced methods for the computation of electromagnetic fields and multiparticle phenomena. This Final Report summarizes the accomplishments of the DSAT Group from its inception in 1980 through its end in 2011.

Alex J. Dragt

2012-08-31T23:59:59.000Z

155

The Electromagnetic Gauge Field Interpolation between the Instant Form and the Front Form of the Hamiltonian Dynamics  

E-Print Network [OSTI]

We present the electromagnetic gauge field interpolation between the instant form and the front form of the relativistic Hamiltonian dynamics and extend our interpolation of the scattering amplitude presented in the simple scalar field theory to the case of the electromagnetic gauge field theory with the scalar fermion fields known as the sQED theory. We find that the Coulomb gauge in the instant form dynamics (IFD) and the light-front gauge in the front form dynamics, or the light-front dynamics (LFD), are naturally linked by the unified general physical gauge that interpolates between these two forms of dynamics and derive the spin-1 polarization vector for the photon that can be generally applicable for any interpolation angle. Corresponding photon propagator for an arbitrary interpolation angle is found and examined in terms of the gauge field polarization and the interpolating time ordering. Using these results, we calculate the lowest-order scattering processes for an arbitrary interpolation angle in sQED. We provide an example of breaking the reflection symmetry under the longitudinal boost, $P^z \\leftrightarrow -P^z$, for the time-ordered scattering amplitude in any interpolating dynamics except the LFD and clarify the confusion in the prevailing notion of the equivalence between the infinite momentum frame (IMF) and the LFD. The particular correlation found in our previous analysis of the scattering amplitude in the simple scalar field theory, coined as the J-shaped correlation, between the total momentum of the system and the interpolation angle persists in the present analysis of the sQED scattering amplitude. We discuss the singular behavior of this correlation in conjunction with the zero-mode issue in the LFD.

Chueng-Ryong Ji; Ziyue Li; Alfredo Takashi Suzuki

2014-12-08T23:59:59.000Z

156

Negative-frequency modes in quantum field theory  

E-Print Network [OSTI]

We consider a departure from standard quantum field theory, constructed so as to permit momentum eigenstates of both positive and negative energy. The resulting theory is intriguing because it brings about the cancellation of leading ultra-violet divergences and the absence of a zero-point energy. The theory gives rise to tree-level source-to-source transition amplitudes that are manifestly causal and consistent with standard S-matrix elements. It also leads to the usual result for the oblique corrections to the standard electroweak theory. Remarkably, the latter agreement relies on the breakdown of naive perturbation theory due to resonance effects. It remains to be shown that there are no problems with perturbative unitarity.

Dickinson, Robert; Millington, Peter

2015-01-01T23:59:59.000Z

157

Negative-frequency modes in quantum field theory  

E-Print Network [OSTI]

We consider a departure from standard quantum field theory, constructed so as to permit momentum eigenstates of both positive and negative energy. The resulting theory is intriguing because it brings about the cancellation of leading ultra-violet divergences and the absence of a zero-point energy. The theory gives rise to tree-level source-to-source transition amplitudes that are manifestly causal and consistent with standard S-matrix elements. It also leads to the usual result for the oblique corrections to the standard electroweak theory. Remarkably, the latter agreement relies on the breakdown of naive perturbation theory due to resonance effects. It remains to be shown that there are no problems with perturbative unitarity.

Robert Dickinson; Jeff Forshaw; Peter Millington

2015-03-06T23:59:59.000Z

158

Radio frequency wave experiments on the MST reversed field pinch  

SciTech Connect (OSTI)

Experiments, simulations, and theory all indicate that the magnetic fluctuations responsible for the poor confinement in the reversed field pinch (RFP) can be controlled by altering the radial profile of the current density. The magnetic fluctuations in the RFP are due to resistive MHD instabilities caused by current profile peaking; thus confinement in the RFP is ultimately the result of a misalignment between inductively driven current profiles and the stable current profiles characteristic of the Taylor state. If a technique such as rf current drive can be developed to non-inductively sustain a Taylor state (a current profile linearly stable to all tearing modes), the confinement of the RFP and its potential as a reactor concept are likely to increase. Whether there is a self-consistent path from poor confinement to greatly improved confinement through current profile modification is an issue for future experiments to address if and only if near term experiments can demonstrate: (1) coupling to and the propagation of rf waves in RFP plasmas, (2) efficient current drive, and (3) control of the power deposition which will make it possible to control the current profile. In this paper, modeling results and experimental plans are presented for two rf experiments which have the potential of satisfying these three goals: high-n{sub {parallel}} lower hybrid (LH) waves and electron Bernstein waves (EBWs).

Forest, C.B.; Chattopadhyay, P.K.; Nornberg, M.D.; Prager, S.C.; Thomas, M.A. [Univ. of Wisconsin, Madison, WI (United States). Physics Dept.; Uchimoto, E. [Univ. of Montana, Missoula, MT (United States). Dept. of Physics and Astronomy; Smirnov, A.P. [Moscow State Univ. (Russian Federation); Harvey, R.W. [CompX, Del Mar, CA (United States); Ram, A.K. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center

1999-04-01T23:59:59.000Z

159

Transient electromagnetic interference in substations  

SciTech Connect (OSTI)

Electromagnetic interference levels on sensitive electronic equipment are quantified experimentally and theoretically in air and gas insulated substations of different voltages. Measurement techniques for recording interference voltages and currents and electric and magnetic fields are reviewed and actual interference data are summarized. Conducted and radiated interference coupling mechanisms and levels in substation control wiring are described using both measurement results and electromagnetic models validated against measurements. The nominal maximum field and control wire interference levels expected in the switchyard and inside the control house from switching operations, faults, and an average lightning strike are estimated using high frequency transient coupling models. Comparisons with standards are made and recommendations given concerning equipment shielding and surge protection.

Wiggins, C.M.; Thomas, D.E.; Nickel, F.S.; Salas, T.M. (BDM International, Inc., Albuquerque, NM (United States)); Wright, S.E. (Electric Power Research Inst., Palo Alto, CA (United States))

1994-10-01T23:59:59.000Z

160

Modeling of capacitive and electromagnetic field shielding effects in a CVT.  

SciTech Connect (OSTI)

In the discharge of a capacitor the current was measured with a current viewing transformer (CVT). In addition to measuring the current flowing through the CVT primary, a 51 MHz noise signal was added to the primary current. When the CVT was covered with a gold shield, the noise was eliminated. Analysis of the measured results indicate that the gold layer reflected the electromagnetic that was generated by current flowing in the primary and that the capacitance between the shield and the CVT secondary had no measurable effect on the CVT output.

Gover, James E. (Kettering University); Bou, Jimmy; Sommerville, William (Kettering University); Sanchez, Robert O.

2005-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Self-Duality in Nonlinear Electromagnetism  

E-Print Network [OSTI]

We discuss duality invariant interactions between electromagnetic fields and matter. The case of scalar fields is treated in some detail.

Mary K. Gaillard; Bruno Zumino

1997-05-28T23:59:59.000Z

162

Electromagnetic WavesElectromagnetic Waves In this chapter we will review selected properties of electromagnetic waves since  

E-Print Network [OSTI]

Electromagnetic WavesElectromagnetic Waves In this chapter we will review selected properties of electromagnetic waves since radar involves the transmission, propagation and scattering of EM waves by various is the electrostatic force between two point charges. #12;Electromagnetic WavesElectromagnetic Waves Electric fields

Rutledge, Steven

163

Linked and knotted beams of light, conservation of helicity and the flow of null electromagnetic fields  

E-Print Network [OSTI]

Maxwell's equations allow for some remarkable solutions consisting of pulsed beams of light which have linked and knotted field lines. The preservation of the topological structure of the field lines in these solutions has previously been ascribed to the fact that the electric and magnetic helicity, a measure of the degree of linking and knotting between field lines, are conserved. Here we show that the elegant evolution of the field is due to the stricter condition that the electric and magnetic fields be everywhere orthogonal. The field lines then satisfy a `frozen field' condition and evolve as if they were unbreakable filaments embedded in a fluid. The preservation of the orthogonality of the electric and magnetic field lines is guaranteed for null, shear-free fields such as the ones considered here by a theorem of Robinson. We calculate the flow field of a particular solution and find it to have the form of a Hopf fibration moving at the speed of light in a direction opposite to the propagation of the pulsed light beam, a familiar structure in this type of solution. The difference between smooth evolution of individual field lines and conservation of electric and magnetic helicity is illustrated by considering a further example in which the helicities are conserved, but the field lines are not everywhere orthogonal. The field line configuration at time t=0 corresponds to a nested family of torus knots but unravels upon evolution.

William T. M. Irvine

2011-10-25T23:59:59.000Z

164

Waveguide-based ultrasonic and far-field electromagnetic sensors for downhole reservoir characterization.  

SciTech Connect (OSTI)

This report summarizes the first year research and development effort leading to development of high-temperature sensors for enhanced geothermal systems. It covers evaluation of ultrasonic and electromagnetic (EM) techniques applied to temperature measurement and flow characterization. On temperature measurement, we have evaluated both microwave radiometry and ultrasonic techniques for temperature gradient and profile measurements. Different antenna designs are evaluated and array loop antenna design is selected for further development. We have also evaluated ultrasonic techniques for total flow characterization, which includes using speed of sound to determine flow temperature, measuring acoustic impedance to estimate fluid density, and using cross-correlation technique to determine the mass flow rate. Method to estimate the flow enthalpy is briefly discussed. At end, the need and proposed techniques to characterize the porosity and permeability of a hot dry rock resource are presented.

Sheen, S. H.; Chien, H. T.; Wang, K.; Liao, S.; Gopalsami, N.; Bakhtiari, S.; Raptis, A. C.; Nuclear Engineering Division

2010-11-12T23:59:59.000Z

165

Project no. 516369 Electromagnetic compatibility between rolling stock and  

E-Print Network [OSTI]

to anything in that environment. Electromagnetic interference (EMI): Degradation of the performance compatibility EMI Electromagnetic interference ETSI European Telecommunications Standards Institute FM Frequency

Paris-Sud XI, Université de

166

PINEAL MELATONIN LEVEL DISRUPTION IN HUMANS DUE TO ELECTROMAGNETIC FIELDS AND ICNIRP LIMITS  

E-Print Network [OSTI]

, thousands of well- documented publications have reported melatonin as a naturally occurring free to power-frequency (50 or 60 Hz) EMFs is unavoidable. Melatonin is a natural hormone produced by pineal Committee of Non-Ionizing Radiation Protection (ICNIRP) limit and also with the existing experimental

Halgamuge, Malka N.

167

FDFD: A 3D FiniteDi#erence FrequencyDomain Code for Electromagnetic Induction Tomography 1  

E-Print Network [OSTI]

the electrical current in­ jection type and the magnetic field type have been well­known for many years [1], e large computer memories and fast computing machines, because it does not take a very large 3D forward was performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory

168

Emerging issues in extremely-low-frequency electric and magnetic field health research  

SciTech Connect (OSTI)

Concern has increased over potential consequences of exposure to electric and magnetic fields of extremely low frequency (0-100 Hz), particularly from power transmission and distribution. Also at issue are electrical environments in homes and workplaces. Until recently, research focused on the electric, rather than the magnetic, field; now, both are under extensive investigation. A review of research to date indicates the following: Electric and magnetic fields can produce effects in vitro, with the locus of field interaction believed to be at the cell membrane. Chronic in vivo electric field exposure fails to produce effects except in behavior, neurophysiology, endocrinology, and, possibly, fetal development. The extrapolation of these animal data to humans requires further research. The epidemiological literature has, in some cases, reported an association between increased cancer rates and putative field exposure. Exposure assessments indicate that, in all likelihood, human exposures to 60-Hz electric fields of the magnitudes found under transmission lines are very infrequent; assessments are continuing to characterize exposure to 60-Hz magnetic fields and to measure the field frequency spectra found in residential and workplace settings. The public health issues emerging from this research focus on fetal development and on the initiation or promotion of cancer. It is critical to reduce existing uncertainties in order to enable valid risk assessment.

Kavet, R.I.; Banks, R.S.

1986-04-01T23:59:59.000Z

169

Lightning strikes to tall objects: Currents inferred from far electromagnetic fields versus directly measured currents  

E-Print Network [OSTI]

-field-to-current conversion factor for lightning strikes to flat ground based on the transmission line model and (b currents on tall towers are used for testing the validity of field-to-current conversion equations [e on current measurement location (e.g., near the top or bottom of the tower) and on whether initial or largest

Florida, University of

170

EMC-ORIENTED ANALYSIS OF ELECTRIC NEAR-FIELD IN HIGH FREQUENCY  

E-Print Network [OSTI]

EMC-ORIENTED ANALYSIS OF ELECTRIC NEAR-FIELD IN HIGH FREQUENCY Ali Alaeldine12 , Olivier Maurice3 - 35043 Rennes Cedex - France 3 EMC for Automotive Systems Group - Research and Development Center - PSA - Route de Gachet - 44300 Nantes - France Abstract. This paper introduces an EMC-oriented study

Paris-Sud XI, Université de

171

Electromagnetic field generation in the downstream of electrostatic shocks due to electron trapping  

E-Print Network [OSTI]

A new magnetic field generation mechanism in electrostatic shocks is found, which can produce fields with magnetic energy density as high as 0.01 of the kinetic energy density of the flows on time scales $ \\tilde \\, 10^4 \\, {\\omega}_{pe}^{-1}$. Electron trapping during the shock formation process creates a strong temperature anisotropy in the distribution function, giving rise to the pure Weibel instability. The generated magnetic field is well-confined to the downstream region of the electrostatic shock. The shock formation process is not modified and the features of the shock front responsible for ion acceleration, which are currently probed in laser-plasma laboratory experiments, are maintained. However, such a strong magnetic field determines the particle trajectories downstream and has the potential to modify the signatures of the collisionless shock.

Stockem, A; Fonseca, R A; Silva, L O

2014-01-01T23:59:59.000Z

172

PHYSICS 416. Electromagnetism. Lecturer: Tim Gorringe.  

E-Print Network [OSTI]

PHYSICS 416. Electromagnetism. Lecturer: Tim Gorringe. Office: CP 273. Phone: 257-8740. Textbook: Electromagnetic Fields, R. Wangsness, 2nd Ed. Web page www.pa.uky.edu/gorringe/phy416/index.html Class hours: MWF-semester sequence on electromagnetic theory. 1 416/417 Course Objectives. The electromagnetic field binds electrons

MacAdam, Keith

173

PHYSICS 417. Electromagnetism. Lecturer: Tim Gorringe.  

E-Print Network [OSTI]

PHYSICS 417. Electromagnetism. Lecturer: Tim Gorringe. Office: CP273. Phone: 257-8740. Textbook: Electromagnetic Fields, R. Wangsness, 2nd Ed. Web page www.pa.uky.edu/gorringe/phy417/index.html Class hours: MWF-semester sequence on electromagnetic theory. 1 Course Objectives. The electromagnetic field binds electrons

MacAdam, Keith

174

On the efficiency of electrical submersible pumps equipped with variable frequency drives: A field study  

SciTech Connect (OSTI)

A field study was conducted on 18 electrical-submersible-pump- (ESP-) equipped wells operating in the Williston basin. Fifteen of these wells were run with variable frequency drives (VFD`s). The purpose of the study was to determine the efficiency and operating characteristics of ESP`s operating with VFD`s and compare them to those without. Voltage, current, power, and frequency were measured at the drive input, the drive output, and ESP input. Production data were recorded and power and efficiency were calculated at all measurement locations and compared to published data.

Patterson, M.M. [Patterson (Maurice M.), Hemphill, TX (United States)

1996-02-01T23:59:59.000Z

175

Analytic model of electromagnetic fields around a plasma bubble in the blow-out regime  

SciTech Connect (OSTI)

An analytic model of the electric and magnetic fields surrounding the nonlinear plasma 'bubble' formed around the high-current electron bunch in a plasma wakefield accelerator is developed. The model, justified by the results of particle-in-cell simulations, accurately captures the thin high-density plasma sheath and extended return current layer surrounding the bubble. The resulting global fields inside and outside the bubble are used to investigate electron self-injection in a plasma with a smooth density gradient. It is shown that accurate description of the current/density sheaths is crucial for quantitative description of self-injection.

Yi, S. A.; Khudik, V.; Siemon, C.; Shvets, G. [Department of Physics and Institute for Fusion Studies, University of Texas, Austin, Texas 78712 (United States)

2013-01-15T23:59:59.000Z

176

Fiber optic probe of free electron evanescent fields in the optical frequency range  

SciTech Connect (OSTI)

We introduce an optical fiber platform which can be used to interrogate proximity interactions between free-electron evanescent fields and photonic nanostructures at optical frequencies in a manner similar to that in which optical evanescent fields are sampled using nanoscale aperture probes in scanning near-field microscopy. Conically profiled optical fiber tips functionalized with nano-gratings are employed to couple electron evanescent fields to light via the Smith-Purcell effect. We demonstrate the interrogation of medium energy (30–50?keV) electron fields with a lateral resolution of a few micrometers via the generation and detection of visible/UV radiation in the 700–300?nm (free-space) wavelength range.

So, Jin-Kyu, E-mail: js1m10@orc.soton.ac.uk; MacDonald, Kevin F. [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Zheludev, Nikolay I. [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371 (Singapore)

2014-05-19T23:59:59.000Z

177

Journal of Electrostatics 65 (2007) 316321 Return stroke current profiles and electromagnetic fields associated with  

E-Print Network [OSTI]

fields associated with lightning strikes to tall towers: Comparison of engineering models D. Pavanelloa strike object, namely the Bruce­Golde (BG) model, the transmission line (TL) model, the traveling current current' (that is the idealized current that would be measured at the tower top if the current reflection

Florida, University of

178

Progress In Electromagnetics Research B, Vol. 13, 120, 2009 MAGNETIC FIELD PRODUCED BY A TILE  

E-Print Network [OSTI]

by permanent magnets is very useful for optimizing alternate magnet structures or magnetic couplings PERMANENT MAGNET WHOSE POLARIZATION IS BOTH UNIFORM AND TANGENTIAL R. Ravaud, G. Lemarquand, V. Lemarquand field produced by a tile permanent magnet whose polarization is both tangential and uniform

Paris-Sud XI, Université de

179

Energy Down Conversion between Classical Electromagnetic Fields via a Quantum Mechanical SQUID Ring  

E-Print Network [OSTI]

We consider the interaction of a quantum mechanical SQUID ring with a classical resonator (a parallel $LC$ tank circuit). In our model we assume that the evolution of the ring maintains its quantum mechanical nature, even though the circuit to which it is coupled is treated classically. We show that when the SQUID ring is driven by a classical monochromatic microwave source, energy can be transferred between this input and the tank circuit, even when the frequency ratio between them is very large. Essentially, these calculations deal with the coupling between a single macroscopic quantum object (the SQUID ring) and a classical circuit measurement device where due account is taken of the non-perturbative behaviour of the ring and the concomitant non-linear interaction of the ring with this device.

M. J. Everitt; T. D. Clark; P. B. Stiffell; C. J. Harland; J. F. Ralph

2005-05-16T23:59:59.000Z

180

Relativistic heat flux for a single component charged fluid in the presence of an electromagnetic field  

E-Print Network [OSTI]

Transport properties in gases are significantly affected by temperature. In previous works it has been shown that when the thermal agitation in a gas is high enough, such that relativistic effects become relevant, heat dissipation is driven not solely by a temperature gradient but also by other vector forces. In the case of relativistic charged fluids, a heat flux is driven by an electrostatic field even in the single species case. The present work generalizes such result by considering also a magnetic field in an arbitrary inertial reference frame. The corresponding constitutive equation is explicitly obtained showing that both electric and magnetic forces contribute to thermal dissipation. This result may lead to relevant effects in plasma dynamics.

Garcia-Perciante, A L; Brun-Battistini, D

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Third order Lovelock black branes in the presence of a nonlinear electromagnetic field  

E-Print Network [OSTI]

We consider third order Lovelock gravity coupled to an U(1) gauge field for which its Lagrangian is given by a power of Maxwell invariant. In this paper, we present a class of horizon flat rotating black branes and investigate their geometrical properties and the effect of nonlinearity on the solutions. We use some known formulas and methods to calculate thermodynamic and conserved quantities. Finally, we check the satisfaction of the first law of thermodynamics.

Hendi, S H; Mohammadpour, H

2015-01-01T23:59:59.000Z

182

Enhanced Field Emission Studies on Niobium Surfaces Relevant to High Field Superconducting Radio-Frequency Devices  

SciTech Connect (OSTI)

Enhanced field emission (EFE) presents the main impediment to higher acceleration gradients in superconducting niobium (Nb) radiofrequency cavities for particle accelerators. The strength, number and sources of EFE sites strongly depend on surface preparation and handling. The main objective of this thesis project is to systematically investigate the sources of EFE from Nb, to evaluate the best available surface preparation techniques with respect to resulting field emission, and to establish an optimized process to minimize or eliminate EFE. To achieve these goals, a scanning field emission microscope (SFEM) was designed and built as an extension to an existing commercial scanning electron microscope (SEM). In the SFEM chamber of ultra high vacuum, a sample is moved laterally in a raster pattern under a high voltage anode tip for EFE detection and localization. The sample is then transferred under vacuum to the SEM chamber equipped with an energy-dispersive x-ray spectrometer for individual emitting site characterization. Compared to other systems built for similar purposes, this apparatus has low cost and maintenance, high operational flexibility, considerably bigger scan area, as well as reliable performance. EFE sources from planar Nb have been studied after various surface preparation, including chemical etching and electropolishing, combined with ultrasonic or high-pressure water rinse. Emitters have been identified, analyzed and the preparation process has been examined and improved based on EFE results. As a result, field-emission-free or near field-emission-free surfaces at ~140 MV/m have been consistently achieved with the above techniques. Characterization on the remaining emitters leads to the conclusion that no evidence of intrinsic emitters, i.e., no fundamental electric field limit induced by EFE, has been observed up to ~140 MV/m. Chemically etched and electropolished Nb are compared and no significant difference is observed up to ~140 MV/m. To address concerns on the effect of natural air drying process on EFE, a comparative study was conducted on Nb and the results showed insignificant difference under the experimental conditions. Nb thin films deposited on Cu present a possible alternative to bulk Nb in superconducting cavities. The EFE performance of a preliminary energetically deposited Nb thin film sample are presented.

Tong Wang

2002-09-18T23:59:59.000Z

183

Characterization of the reactive flow field dynamics in a gas turbine injector using high frequency PIV  

E-Print Network [OSTI]

The present work details the analysis of the aerodynamics of an experimental swirl stabilized burner representative of gas turbine combustors. This analysis is carried out using High Frequency PIV (HFPIV) measurements in a reactive situation. While this information is usually available at a rather low rate, temporally resolved PIV measurements are necessary to better understand highly turbulent swirled flows, which are unsteady by nature. Thanks to recent technical improvements, a PIV system working at 12 kHz has been developed to study this experimental combustor flow field. Statistical quantities of the burner are first obtained and analyzed, and the measurement quality is checked, then a temporal analysis of the velocity field is carried out, indicating that large coherent structures periodically appear in the combustion chamber. The frequency of these structures is very close to the quarter wave mode of the chamber, giving a possible explanation for combustion instability coupling.

Barbosa, Séverine; Ducruix, Sébastien

2008-01-01T23:59:59.000Z

184

Electric dipole moment searches: Effect of linear electric field frequency shifts induced in confined gases, II  

E-Print Network [OSTI]

The next generation of particle edm searches will be at such a high sensitivity that it will be possible for the results to be contaminated by a systematic error resulting from the interaction of the motional (E x v/c) magnetic field with stray field gradients. In this paper we extend previous work to present an analytic form for the frequency shift in the case of a rectangular storage vessel and discuss the implications of the result for the neutron edm experiment which will be installed at the SNS (Spallation Neutron Source) by the LANL collaboration

R. Golub; C. M. Swank; S. K. Lamoreaux

2009-06-03T23:59:59.000Z

185

Control of resonant frequency by currents in graphene: Effect of Dirac field on deflection  

SciTech Connect (OSTI)

To construct Lagrangian based on plate theory and tight-binding model, deflection-field coupling to Dirac fermions in graphene can be investigated. As have been known, deflection-induced strain may cause an effect on motion of electron, like a pseudo gauge field. In the work, we will investigate the effect of the Dirac field on the motion of the deflection-field in graphene derived from Lagrangian density. Due to the interaction of the deflection- and Dirac-fields, the current-induced surface-tension up to about 4×10{sup ?3} N/m in graphene membrane is predicted. This result may lead to controllable resonant frequency by currents in graphene. The high resonant frequency is found to be perfectly linearly controlled by both charge and valley currents. Our work reveals the potential of graphene for application of nano-electro-mechanical device and the physics of interaction of electron and deflection-filed in graphene system is investigated.

Soodchomshom, Bumned, E-mail: Bumned@hotmail.com, E-mail: fscibns@ku.ac.th [Department of Physics, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand)

2014-09-21T23:59:59.000Z

186

Coupling of electrons to the electromagnetic field in a localized basis  

E-Print Network [OSTI]

, such as materials and molecules, responding to ap- plied fields, such as ultrashort laser pulses.9?19 Our starting point is, of course, the time-dependent Schr?dinger equation, i#1; #1; #1;t #2;#1;x,t#2; = H? #2;#1;x,t#2; , #1;1#2; H? = 1 2m#3;? i#1; #1...; ? qc A#1;x,t#2;#4;2 + U, q = ? e . #1;2#2; Some time ago, Graf and Vogl20 obtained a result, used in Refs. 13?19, which is the time-dependent version of the Peierls substitution: If H0 is the Hamiltonian matrix in a localized basis with no applied...

Allen, Roland E.

2008-01-01T23:59:59.000Z

187

Control of the electromagnetic environment of a quantum emitter by shaping the vacuum field in a coupled-cavity system  

E-Print Network [OSTI]

We propose a scheme for the ultrafast control of the emitter-field coupling rate in cavity quantum electrodynamics. This is achieved by the control of the vacuum field seen by the emitter through a modulation of the optical modes in a coupled-cavity structure. The scheme allows the on/off switching of the coupling rate without perturbing the emitter and without introducing frequency chirps on the emitted photons. It can be used to control the shape of single-photon pulses for high-fidelity quantum state transfer, to control Rabi oscillations and as a gain-modulation method in lasers. We discuss two possible experimental implementations based on photonic crystal cavities and on microwave circuits.

Robert Johne; Ron Schutjens; Sartoon Fattah poor; Chao-Yuan Jin; Andrea Fiore

2015-03-20T23:59:59.000Z

188

Nonlocal theory of electromagnetic wave decay into two electromagnetic waves in a rippled density plasma channel  

SciTech Connect (OSTI)

Parametric decay of a large amplitude electromagnetic wave into two electromagnetic modes in a rippled density plasma channel is investigated. The channel is taken to possess step density profile besides a density ripple of axial wave vector. The density ripple accounts for the momentum mismatch between the interacting waves and facilitates nonlinear coupling. For a given pump wave frequency, the requisite ripple wave number varies only a little w.r.t. the frequency of the low frequency decay wave. The radial localization of electromagnetic wave reduces the growth rate of the parametric instability. The growth rate decreases with the frequency of low frequency electromagnetic wave.

Sati, Priti; Tripathi, V. K. [Indian Institute of Technology, Hauz Khas, Delhi 110054 (India)

2012-12-15T23:59:59.000Z

189

Coronary heart diseases: Assessment of risk associated with work exposure to ultralow-frequency magnetic fields  

SciTech Connect (OSTI)

The present analysis was stimulated by previous findings on the possible influence of natural ultralow-frequency (ULF; 0.001--10 Hz) geomagnetic field variations on the cardiovascular system and indications of an effect of man-made ULF magnetic fields on the rate of myocardial infarction. In the present study, the authors considered the occupational health hazards of the strongest ULF magnetic fields in densely populated urban areas. Measurements of ULF magnetic field fluctuations produced by trains powered by DC electricity were performed by means of a computer-based, highly sensitive, three-component magnetometer. The authors found that the magnitude of magnetic field pulses inside the driver`s cab of electric locomotives (ELs) could be {ge} 280 {micro}T in the vertical component, and, in the driver`s compartment of electric motor unit (EMU) trains, they were approximately 50 and 35 {micro}T, respectively. The authors have investigated the relationships between the occupational exposure to ULF magnetic field fluctuations produced by electric trains and cardiovascular diseases (CVDs) among railroad workers in the former Soviet Union. They have analyzed medical statistical data for a period of 3 years for approximately 45,000 railroad workers and 4,000 engine drivers. The authors have also analyzed 3 years of morbidity data for three subgroups of engine drivers ({approximately} 4,000 in each group) operating different types of trains. They find that EL drivers have a twofold increase in risk (2.00 {+-} 0.27) of coronary heart diseases (CHDs) compared with EMU drivers. Because the analysis of major CVDs shows that the examined subpopulations of drivers can be considered to have had equal exposure to all known risk factors, the elevated CHD risk among El drivers could be attributed to the increased occupational exposure to ULF magnetic fields.

Ptitsyna, N.G.; Kopytenko, Y.A.; Tyasto, M.I.; Kopytenko, E.A.; Voronov, P.M.; Zaitsev, D.B. [Inst. of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation, St. Petersburg (Russian Federation)] [Inst. of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation, St. Petersburg (Russian Federation); Villoresi, G. [CNR, Frascati (Italy). Inst. di Fisica Spazio Interplanetario] [CNR, Frascati (Italy). Inst. di Fisica Spazio Interplanetario; Kudrin, V.A. [Inst. of Railroad Workers` Hygiene, Moscow (Russian Federation)] [Inst. of Railroad Workers` Hygiene, Moscow (Russian Federation); Iucci, N. [Terza Univ. di Roma, Rome (Italy). Dipt. di Fisica E. Amaldi] [Terza Univ. di Roma, Rome (Italy). Dipt. di Fisica E. Amaldi

1996-12-31T23:59:59.000Z

190

Enhanced stability of a dewetting thin liquid film in a single-frequency vibration field S. Shklyaev,1  

E-Print Network [OSTI]

amplitude equation for the averaged film thickness. We show that there exists a window in the frequencyEnhanced stability of a dewetting thin liquid film in a single-frequency vibration field S; published 31 March 2008 Dynamics of a thin dewetting liquid film on a vertically oscillating substrate

Khenner, Mikhail

191

The interaction of radio frequency electromagnetic fields with atmospheric water droplets and application to aircraft ice prevention  

E-Print Network [OSTI]

In this work the physics of advanced microwave anti-icing systems, which pre-heat impinging supercooled water droplets prior to impact, is studied by means of a computer simulation and is found to be feasible. In order to ...

Hansman, Robert John

1982-01-01T23:59:59.000Z

192

Beam dynamics studies for transverse electromagnetic mode type rf deflectors  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

We have performed three-dimensional simulations of beam dynamics for transverse electromagnetic mode (TEM) type rf deflectors: normal and superconducting. The compact size of these cavities as compared to the conventional TM110 type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a single cell superconducting structure is enough to produce the required vertical displacement at the target point. Both the normal and superconducting structures show very small emittance dilution due to the vertical kick of the beam.

Ahmed, Shahid; Krafft, Geoffrey A.; Deitrick, Kirsten; De Silva, Subashini U.; Delayen, Jean R.; Spata, Mike; Tiefenback, Michael; Hofler, Alicia; Beard, Kevin

2012-02-01T23:59:59.000Z

193

Reverse Time Migration for Extended Obstacles: Electromagnetic Waves  

E-Print Network [OSTI]

We propose a new single frequency reverse time migration (RTM) algorithm for imaging extended targets using electromagnetic waves. The imaging functional is defined as the imaginary part of the cross-correlation of the Green function for Helmholtz equation and the back-propagated electromagnetic field. The resolution of our RTM method for both penetrable and non-penetrable extended targets is studied by virtue of Helmholtz-Kirchhoff identity for the time-harmonic Maxwell equation. The analysis implies that our imaging functional is always positive and thus may have better stability properties. Numerical examples are provided to demonstrate the powerful imaging quality and confirm our theoretical results.

Junqing Chen; Zhiming Chen; Guanghui Huang

2014-06-10T23:59:59.000Z

194

Statistics of the electromagnetic response of a chaotic reverberation chamber  

E-Print Network [OSTI]

This article presents a study of the electromagnetic response of a chaotic reverberation chamber (RC) in the presence of losses. By means of simulations and of experiments, the fluctuations in the maxima of the field obtained in a conventional mode-stirred RC are compared with those in a chaotic RC in the neighborhood of the Lowest Useable Frequency (LUF). The present work illustrates that the universal spectral and spatial statistical properties of chaotic RCs allow to meet more adequately the criteria required by the Standard IEC 61000-4-21 to perform tests of electromagnetic compatibility.

J. -B. Gros; U. Kuhl; O. Legrand; F. Mortessagne; O. Picon; E. Richalot

2014-09-20T23:59:59.000Z

195

611: Electromagnetic Theory Problem Sheet 5  

E-Print Network [OSTI]

611: Electromagnetic Theory Problem Sheet 5 (1a) Show that the energy-momentum tensor for the electromagnetic field is tracefree, i.e. Tµ µ = 0. What would happen, in a spacetime dimension d = 4? (Assume) Show that the energy-momentum tensor for the electromagnetic field can be written as Tµ = 1 8 (Fµ F

Pope, Christopher

196

Why Study Electromagnetics: The First Unit in an Undergraduate Electromagnetics Course  

E-Print Network [OSTI]

1 Why Study Electromagnetics: The First Unit in an Undergraduate Electromagnetics Course Allen unification of electric and magnetic fields predicting electromagnetic wave phenomena which Nobel Laureate: "Of what relevance is the study of electromagnetics to our modern society?" The goal of this unit

Taflove, Allen

197

A low-frequency passive seismic array experiment over an onshore oil field in Abu Dhabi, United Arab Emirates  

E-Print Network [OSTI]

oil field in the emirate of Abu Dhabi in the United Arab Emirates. The aim of the experiment Arab Emirates Mohammed Y. Ali1 , Braham Barkat1 , Karl A. Berteussen1 , and James Small1 ABSTRACT A lowA low-frequency passive seismic array experiment over an onshore oil field in Abu Dhabi, United

Ali, Mohammed

198

Dr. S. Cruz-Pol, INEL 4152-Electromagnetics  

E-Print Network [OSTI]

field density [VF/m2] Ã?H = magnetic field intensity, [A/m] Ã?B = magnetic field density, [Teslas] Take JdlH Cruz-Pol, Electromagnetics UPRM Electromagnetics Ã? This is the principle of motors, hydro

Cruz-Pol, Sandra L.

199

Quaternion Gravi-Electromagnetism  

E-Print Network [OSTI]

Defining the generalized charge, potential, current and generalized fields as complex quantities where real and imaginary parts represent gravitation and electromagnetism respectively, corresponding field equation, equation of motion and other quantum equations are derived in manifestly covariant manner. It has been shown that the field equations are invariant under Lorentz as well as duality transformations. It has been shown that the quaternionic formulation presented here remains invariant under quaternion transformations.

A. S. Rawat; O. P. S. Negi

2011-07-05T23:59:59.000Z

200

Electromagnetic Signals from Bacterial DNA  

E-Print Network [OSTI]

Chemical reactions can be induced at a distance due to the propagation of electromagnetic signals during intermediate chemical stages. Although is is well known at optical frequencies, e.g. photosynthetic reactions, electromagnetic signals hold true for muck lower frequencies. In E. coli bacteria such electromagnetic signals can be generated by electric transitions between energy levels describing electrons moving around DNA loops. The electromagnetic signals between different bacteria within a community is a "wireless" version of intercellular communication found in bacterial communities connected by "nanowires". The wireless broadcasts can in principle be of both the AM and FM variety due to the magnetic flux periodicity in electron energy spectra in bacterial DNA orbital motions.

A. Widom; J. Swain; Y. N. Srivastava; S. Sivasubramanian

2012-02-09T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Some Wave Equations for Electromagnetism and Gravitation  

E-Print Network [OSTI]

The paper studies the inferences of wave equations for electromagnetic fields when there are gravitational fields at the same time. In the description with the algebra of octonions, the inferences of wave equations are identical with that in conventional electromagnetic theory with vector terminology. By means of the octonion exponential function, we can draw out that the electromagnetic waves are transverse waves in a vacuum, and rephrase the law of reflection, Snell's law, Fresnel formula, and total internal reflection etc. The study claims that the theoretical results of wave equations for electromagnetic strength keep unchanged in the case for coexistence of gravitational and electromagnetic fields. Meanwhile the electric and magnetic components of electromagnetic waves can not be determined simultaneously in electromagnetic fields.

Zi-Hua Weng

2010-08-11T23:59:59.000Z

202

Course Outline Physics 433: Electromagnetism II  

E-Print Network [OSTI]

Course Outline Physics 433: Electromagnetism II Spring 2014 Prof. Keun Hyuk "Ken" Ahn 483 Tiernan of this course is on the elementary concepts of electromagnetic fields. Upon completion of the course, students are expected to be capable of using the Maxwell equations to calculate simple electromagnetic problems, ranging

203

611: Electromagnetic Theory Problem Sheet 5  

E-Print Network [OSTI]

611: Electromagnetic Theory Problem Sheet 5 (1) Consider the expression for the electric field due · dS over a spherical surface that encloses the moving charge. (2a) Consider an electromagnetic wave density and the Poynting vector. (2c) Repeat the steps in (2a) and (2b) for an electromagnetic wave

Pope, Christopher

204

611: Electromagnetic Theory Problem Sheet 6  

E-Print Network [OSTI]

611: Electromagnetic Theory Problem Sheet 6 (1) Consider the expression for the electric field due · dS over a spherical surface that encloses the moving charge. (2a) Consider an electromagnetic wave density and the Poynting vector. (2c) Repeat the steps in (2a) and (2b) for an electromagnetic wave

Pope, Christopher

205

Electromagnetics from Simulation to Optimal Design  

E-Print Network [OSTI]

1 Electromagnetics from Simulation to Optimal Design Christian Hafner Laboratory for Electromagnetic Fields and Microwave Electronics (IFH) ETH Zurich (Switzerland) Lab: http://www.ifh.ee.ethz.ch COG 23, 2013 #12;2 IFH courses · Advanced engineering electromagnetics (Leuchtmann, start spring 2014

Lang, Annika

206

The influence of oscillating electromagnetic fields on membrane structure and function: Synthetic liposome and natural membrane bilayer systems with direct application to the controlled delivery of chemical agents  

SciTech Connect (OSTI)

Investigations have been conducted to determine if an imposed electromagnetic field can influence membrane transport, and ion and drug permeability in both synthetic and natural cell membrane systems. Microwave fields enhance accumulation of sodium in the lymphocyte and induce protein shedding at Tc. Microwaves also trigger membrane permeability of liposome systems under specific field exposure conditions. Sensitivity varies in a defined way in bilayers displaying a membrane structural phase transition temperature, Tc; maximal release was observed at or near Tc. Significantly, liposome systems without a membrane phase transition were also found to experience permeability increases but, in contrast, this response was temperature independent. The above results indicate that field-enhanced drug release occurs in liposome vesicles that possess a Tc as well as non-Tc liposomes. Additional studies extend non-Tc liposome responses to the in vivo case in which microwaves trigger Gentamicin release from a liposome depot'' placed subcutaneously in the rat hind leg. In addition, evidence is provided that cell surface sequestered liposomes can be triggered by microwave fields to release drugs directly into target cells. 24 refs., 6 figs.

Liburdy, R.P.; de Manincor, D.; Fingado, B.

1989-09-01T23:59:59.000Z

207

Space-time Curvature of Classical Electromagnetism  

E-Print Network [OSTI]

The space-time curvature carried by electromagnetic fields is discovered and a new unification of geometry and electromagnetism is found. Curvature is invariant under charge reversal symmetry. Electromagnetic field equations are examined with De Rham co homology theory. Radiative electromagnetic fields must be exact and co exact to preclude unobserved massless topological charges. Weyl's conformal tensor, here called ``the gravitational field'', is decomposed into a divergence-free non-local piece with support everywhere and a local piece with the same support as the matter. By tuning a local gravitational field to a Maxwell field the electromagnetic field's local gravitational field is discovered. This gravitational field carries the electromagnetic field's polarization or phase information, unlike Maxwell's stress-energy tensor. The unification assumes Einstein's equations and derives Maxwell's equations from curvature assumptions. Gravity forbids magnetic monopoles! This unification is stronger than the Einstein-Maxwell equations alone, as those equations must produce the electromagnetic field's local gravitational field and not just any conformal tensor. Charged black holes are examples. Curvature of radiative null electromagnetic fields is characterized.

R. W. M. Woodside

2004-10-08T23:59:59.000Z

208

Field Verification of Energy and Demand Savings of Two Injection Molding Machines Retrofitted with Variable Frequency Drives  

E-Print Network [OSTI]

Detailed field measurements of energy consumption (kWh) and demand (kW) are conducted on two injection molding machines (IMMs) used in a typical plastic manufacturing facility in the San Francisco Bay Area, with/without Variable Frequency Drives...

Liou, S. P.; Aguiar, D.

209

Electromagnetic properties of baryons  

SciTech Connect (OSTI)

We discuss the chiral behavior of the nucleon and {Delta}(1232) electromagnetic properties within the framework of a SU(2) covariant baryon chiral perturbation theory. Our one-loop calculation is complete to the order p{sup 3} and p{sup 4}/{Delta} with {Delta} as the {Delta}(1232)-nucleon energy gap. We show that the magnetic moment of a resonance can be defined by the linear energy shift only when an additional relation between the involved masses and the applied magnetic field strength is fulfilled. Singularities and cusps in the pion mass dependence of the {Delta}(1232) electromagnetic moments reflect a non-fulfillment. We show results for the pion mass dependence of the nucleon iso-vector electromagnetic quantities and present preliminary results for finite volume effects on the iso-vector anomalous magnetic moment.

Ledwig, T.; Pascalutsa, V.; Vanderhaeghen, M. [Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany); Martin-Camalich, J. [Departamento de Fisica Teorica and IFIC, Universidad de Valencia-CSIC, Spain and Department of Physics and Astronomy, University of Sussex, BN1 9Qh, Brighton (United Kingdom)

2011-10-21T23:59:59.000Z

210

Electromagnetic waves in a polydisperse dusty plasma  

SciTech Connect (OSTI)

The properties of low-frequency electromagnetic waves in a polydisperse dusty plasma are studied. The dispersion relation for the waves propagating at an arbitrary angle to the external magnetic field is derived, with the coefficients explicitly determined by the dust-size distribution function. The dependence of wave dispersion on properties of the dust-size distribution function is analysed. It is shown that the cutoff for an oblique propagation in plasma with a wide scatter of dust sizes takes place at a much lower frequency than in a plasma with monosized dust particles. It is found that dispersion properties of a transversal magnetosonic wave mode around dust–cyclotron frequencies considerably differ from those in a plasma with monosized dust. In a plasma with low mass fraction of dust particles, the dispersion is smooth without the cutoff and the resonance intrinsic for a plasma with monosized dust. Increase of the dust fraction results in splitting of the dispersion curve on to two branches. Further increase of the dust fraction leads to emergence of the third branch located between the cutoffs and restricted from the lower and higher frequencies by two resonances. The dependence of the frequencies of cutoffs and resonances on the width of the dust-size distribution, its slope and the dust mass fraction are analysed. It is shown that the transparency frequency windows in a plasma with polydisperse dust are wider for transversal elecromagnetic waves, but narrower for longitudinal or oblique waves.

Prudskikh, V. V.; Shchekinov, Yu. A. [Department of Physics, Southern Federal University, Rostov on Don 344090 (Russian Federation)] [Department of Physics, Southern Federal University, Rostov on Don 344090 (Russian Federation)

2013-10-15T23:59:59.000Z

211

LOW-FREQUENCY IMAGING OF FIELDS AT HIGH GALACTIC LATITUDE WITH THE MURCHISON WIDEFIELD ARRAY 32 ELEMENT PROTOTYPE  

SciTech Connect (OSTI)

The Murchison Widefield Array (MWA) is a new low-frequency, wide-field-of-view radio interferometer under development at the Murchison Radio-astronomy Observatory in Western Australia. We have used a 32 element MWA prototype interferometer (MWA-32T) to observe two 50 Degree-Sign diameter fields in the southern sky, covering a total of {approx}2700 deg{sup 2}, in order to evaluate the performance of the MWA-32T, to develop techniques for epoch of reionization experiments, and to make measurements of astronomical foregrounds. We developed a calibration and imaging pipeline for the MWA-32T, and used it to produce {approx}15' angular resolution maps of the two fields in the 110-200 MHz band. We perform a blind source extraction using these confusion-limited images, and detect 655 sources at high significance with an additional 871 lower significance source candidates. We compare these sources with existing low-frequency radio surveys in order to assess the MWA-32T system performance, wide-field analysis algorithms, and catalog quality. Our source catalog is found to agree well with existing low-frequency surveys in these regions of the sky and with statistical distributions of point sources derived from Northern Hemisphere surveys; it represents one of the deepest surveys to date of this sky field in the 110-200 MHz band.

Williams, Christopher L.; Hewitt, Jacqueline N.; Levine, Alan M. [MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA (United States); De Oliveira-Costa, Angelica; Hernquist, Lars L.; Bernardi, Gianni [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Bowman, Judd D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ (United States); Briggs, Frank H. [Research School of Astronomy and Astrophysics, The Australian National University, Canberra (Australia); Gaensler, B. M.; Mitchell, Daniel A.; Subrahmanyan, Ravi; Sadler, Elaine M. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Morales, Miguel F. [Department of Physics, University of Washington, Seattle, WA (United States); Sethi, Shiv K. [Raman Research Institute, Bangalore (India); Arcus, Wayne; Crosse, Brian W. [International Centre for Radio Astronomy Research, Curtin University, Perth (Australia); Barnes, David G. [Center for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne (Australia); Bunton, John D. [CSIRO Astronomy and Space Science, Epping (Australia); Cappallo, Roger C.; Corey, Brian E., E-mail: clmw@mit.edu [MIT Haystack Observatory, Westford, MA (United States); and others

2012-08-10T23:59:59.000Z

212

Electromagnetic reactions on light nuclei  

E-Print Network [OSTI]

Electromagnetic reactions on light nuclei are fundamental to advance our understanding of nuclear structure and dynamics. The perturbative nature of the electromagnetic probes allows to clearly connect measured cross sections with the calculated structure properties of nuclear targets. We present an overview on recent theoretical ab-initio calculations of electron-scattering and photonuclear reactions involving light nuclei. We encompass both the conventional approach and the novel theoretical framework provided by chiral effective field theories. Because both strong and electromagnetic interactions are involved in the processes under study, comparison with available experimental data provides stringent constraints on both many-body nuclear Hamiltonians and electromagnetic currents. We discuss what we have learned from studies on electromagnetic observables of light nuclei, starting from the deuteron and reaching up to nuclear systems with mass number A=16.

Sonia Bacca; Saori Pastore

2014-07-13T23:59:59.000Z

213

Elec Eng 2FH3 Electromagnetics I COURSE NUMBER & TITLE: Elec Eng 2FH3 Electromagnetics I  

E-Print Network [OSTI]

Elec Eng 2FH3 ­ Electromagnetics I COURSE NUMBER & TITLE: Elec Eng 2FH3 ­ Electromagnetics I field 6. Inductance 7. Faraday's law CALENDAR DESCRIPTION: Electromagnetics Part I is an introduction into engineering electromagnetics. It covers the mathematical foundations such as selected topics of vector

Haykin, Simon

214

High-frequency and -field EPR and FDMRS study of the [Fe(H2O)6]2+ ion in ferrous  

E-Print Network [OSTI]

High-frequency and -field EPR and FDMRS study of the [Fe(H2O)6]2+ ion in ferrous fluorosilicate J online 29 September 2011 Keywords: High-field EPR Spin Hamiltonian Zero-field splitting Iron(II) a b Resonance (EPR) at conventional frequencies (9­95 GHz) and fields (0­3.5 T), the non-Kramers (integer spin

McQuade, D. Tyler

215

Impact of contact and access resistances in graphene field-effect transistors on quartz substrates for radio frequency applications  

SciTech Connect (OSTI)

High-frequency performance of graphene field-effect transistors (GFETs) has been limited largely by parasitic resistances, including contact resistance (R{sub C}) and access resistance (R{sub A}). Measurement of short-channel (500?nm) GFETs with short (200?nm) spin-on-doped source/drain access regions reveals negligible change in transit frequency (f{sub T}) after doping, as compared to ?23% f{sub T} improvement for similarly sized undoped GFETs measured at low temperature, underscoring the impact of R{sub C} on high-frequency performance. DC measurements of undoped/doped short and long-channel GFETs highlight the increasing impact of R{sub A} for larger GFETs. Additionally, parasitic capacitances were minimized by device fabrication using graphene transferred onto low-capacitance quartz substrates.

Ramón, Michael E., E-mail: michael.ramon@utexas.edu, E-mail: hemacp@utexas.edu; Movva, Hema C. P., E-mail: michael.ramon@utexas.edu, E-mail: hemacp@utexas.edu; Fahad Chowdhury, Sk.; Parrish, Kristen N.; Rai, Amritesh; Akinwande, Deji; Banerjee, Sanjay K. [Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78758 (United States); Magnuson, Carl W.; Ruoff, Rodney S. [Department of Mechanical Engineering and the Materials Science and Engineering Program, The University of Texas at Austin, Austin, Texas 78712 (United States)

2014-02-17T23:59:59.000Z

216

Gravitation and electromagnetism  

E-Print Network [OSTI]

Maxwell's equations comprise both electromagnetic and gravitational fields. The transverse part of the vector potential belongs to magnetism, the longitudinal one is concerned with gravitation. The Coulomb gauge indicates that longitudinal components of the fields propagate instantaneously. The delta-function singularity of the field of the divergence of the vector potential, referred to as the dilatation center, represents an elementary agent of gravitation. Viewing a particle as a source or a scattering center of the point dilatation, the Newton's gravitation law can be reproduced.

V. P. Dmitriyev

2002-07-23T23:59:59.000Z

217

Strong permanent magnet-assisted electromagnetic undulator  

DOE Patents [OSTI]

This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles.

Halbach, Klaus (Berkeley, CA)

1988-01-01T23:59:59.000Z

218

Electromagnetic two-dimensional analysis of trapped-ion eigenmodes  

SciTech Connect (OSTI)

A two-dimensional electromagnetic analysis of the trapped-ion instability for the tokamak case with ..beta.. not equal to 0 has been made, based on previous work in the electrostatic limit. The quasineutrality condition and the component of Ampere's law along the equilibrium magnetic field are solved for the perturbed electrostatic potential and the component of the perturbed vector potential along the equilibrium magnetic field. The general integro-differential equations are converted into a matrix eigenvalue-eigenfunction problem by expanding in cubic B-spline finite elements in the minor radius and in Fourier harmonics in the poloidal angle. A model MHD equilibrium with circular, concentric magnetic surfaces and large aspect ratio is used which is consistent with our assemption that B << 1. The effect on the trapped-ion mode of including these electromagnetic extensions to the calculation is considered, and the temperature (and ..beta..) scaling of the mode frequency is shown and discussed.

Kim, D.; Rewoldt, G.

1984-11-01T23:59:59.000Z

219

A new electromagnetic code for ICRF antenna in EAST  

E-Print Network [OSTI]

The demand for an effective tool to help in the design of ion cyclotron radio frequency (ICRF) antenna system for fusion experiment has driven the development of predictive codes. A new electromagnetic code based on the method of moments (MOM) is described in the paper. The code computes the electromagnetic field by the solution of the electric field integral equation. The structure of ICRF antennas are discretized with triangular mesh. By using the new code, the scattering parameter and the surface current are given and compared with the result by commercial code CST. Moreover, the power spectra are studied with different toroidal phases for heating and current drive. Good agreement of simulation results between the new code and CST are obtained. The code has been validated against CST for EAST ICRF antenna.

Yang, Hua; Dong, Sa; Zhang, Xin-Jun; Zhao, Yan-Ping; Shang, Lei

2015-01-01T23:59:59.000Z

220

Electromagnetic Reciprocity.  

SciTech Connect (OSTI)

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 and now a geophysical consultant ) and Dr. Chester J. Weiss (recently rejoined with Sandia National Laboratories) for many stimulating (and reciprocal!) discussions regar ding the topic at hand.

Aldridge, David F.

2014-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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221

Progress In Electromagnetics Research M, Vol. 35, 173182, 2014 Three-Dimensional Analytical Model for an Axial-Field  

E-Print Network [OSTI]

--In this paper, we propose an analytical method for modeling a permanent magnets axial field magnetic coupling. Shaft Rout Magnets Soft-Iron yoke h h Rin e To load From motor Magnetic coupling Figure 1. Structure equipped with axially magnetized permanent magnets (PMs). The PMs are glued on an iron yoke to form a north

Paris-Sud XI, Université de

222

Development of a 2D Analytical Model for the Electromagnetic Computation of Axial-Field Magnetic Gears  

E-Print Network [OSTI]

, they present many advantages compared to mechanical gearboxes such as low acoustic noise, low vibrations geometry such as coaxial magnetic gear [17], [18] or radial-field PMs motors with semi-closed slots [19], [20]. In these cases, the slots are open on two sides (tooth-tips for PMs motors), hence the problem

Paris-Sud XI, Université de

223

HIGH-FREQUENCY RADIO SPECTRAL ENERGY DISTRIBUTIONS AND POLARIZATION FRACTIONS OF SOURCES IN AN ATACAMA COSMOLOGY TELESCOPE SURVEY FIELD  

SciTech Connect (OSTI)

We present flux densities and polarization percentages of 159 radio galaxies based on nearly simultaneous Very Large Array observations at four frequencies, 4.86, 8.46, 22.46, and 43.34 GHz. This sample is selected from the high-frequency Australia Telescope 20 GHz (AT20G) survey and consists of all sources with flux density S{sub 20GHz} > 40 mJy in an equatorial field of the Atacama Cosmology Telescope (ACT) survey. For a subset of 25 of these sources, we used the Green Bank Telescope (GBT) to obtain 90 GHz data. The goals of this program are: (1) a characterization of the spectra, polarization, and variability of high-frequency-selected radio sources, (2) extrapolating from the few GHz regime to the {approx}150 GHz regime of the ACT survey, allowing for more accurate removal of the radio source signal in our particular field, and (3) providing a data set that will allow more accurate modeling of the high-frequency radio source contamination in current and future Sunyaev-Zeldovich and cosmic microwave background experiments. We find that, as expected, this sample consists of flatter spectrum and more compact or point-like sources than low-frequency-selected samples. In the K band, variability is typically {approx}<20%, although there are exceptions. The higher frequency data are well suited to the detection of extreme gigahertz peak spectrum sources. The inclusion of the 43 GHz data causes the relative fraction of inverted spectrum sources to go down and of peaked spectrum sources to go up when compared with the AT20G survey results. The trend largely continues with the inclusion of the 90 GHz data, although {approx}10% of the sources with GBT data show a spectral upturn from 43 GHz to 90 GHz. The measured polarization fractions are typically <5%, although in some cases they are measured to be up to {approx}20%. For sources with detected polarized flux in all four bands, about 40% of the sample, the polarization fractions typically increase with frequency. This trend is stronger for steeper spectrum sources as well as for the lower flux density sources.

Sajina, Anna [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Partridge, Bruce; Evans, Tyler; Vechik, Nicholas [Department of Physics and Astronomy, Haverford College, Haverford, PA 19041 (United States); Stefl, Shannon [Kent State University, Kent, OH 44242 (United States); Myers, Steve [National Radio Astronomy Observatory, Socorro, NM 87801 (United States); Dicker, Simon; Korngut, Phillip [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States)

2011-05-01T23:59:59.000Z

224

Effects of Three-Dimensional Electromagnetic Structures on Resistive-Wall-Mode Stability of Reversed Field Pinches  

SciTech Connect (OSTI)

In this Letter, the linear stability of the resistive wall modes (RWMs) in toroidal geometry for a reversed field pinch (RFP) plasma is studied. Three computational models are used: the cylindrical code ETAW, the toroidal MHD code MARS-F, and the CarMa code, able to take fully into account the effects of a three-dimensional conducting structure which mimics the real shell geometry of a reversed field pinch experimental device. The computed mode growth rates generally agree with experimental data. The toroidal effects and the three-dimensional features of the shell, like gaps, allow a novel interpretation of the RWM spectrum in RFP's and remove its degeneracy. This shows the importance of making accurate modeling of conductors for the RWM predictions also in future devices such as ITER.

Villone, F. [Ass. Euratom/ENEA/CREATE, DAEIMI, Universita di Cassino, Via Di Biasio 43, 03043, Cassino (Italy); Liu, Y. Q. [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Paccagnella, R.; Bolzonella, T. [Consorzio RFX, Ass. Euratom/ENEA, and C.N.R., Corso Stati Uniti 4, 35127, Padova (Italy); Rubinacci, G. [Ass. Euratom/ENEA/CREATE, DIEL, Universita di Napoli Federico II, Via Claudio 21, 80125, Napoli (Italy)

2008-06-27T23:59:59.000Z

225

Computational Electronics and Electromagnetics  

SciTech Connect (OSTI)

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.

DeFord, J.F.

1993-03-01T23:59:59.000Z

226

Poynting-vector based method for determining the bearing and location of electromagnetic sources  

DOE Patents [OSTI]

A method and apparatus is utilized to determine the bearing and/or location of sources, such as, alternating current (A.C.) generators and loads, power lines, transformers and/or radio-frequency (RF) transmitters, emitting electromagnetic-wave energy for which a Poynting-Vector can be defined. When both a source and field sensors (electric and magnetic) are static, a bearing to the electromagnetic source can be obtained. If a single set of electric (E) and magnetic (B) sensors are in motion, multiple measurements permit location of the source. The method can be extended to networks of sensors allowing determination of the location of both stationary and moving sources.

Simons, David J. (Modesto, CA); Carrigan, Charles R. (Tracy, CA); Harben, Philip E. (Livermore, CA); Kirkendall, Barry A. (Golden, CO); Schultz, Craig A. (Danville, CA)

2008-10-21T23:59:59.000Z

227

Linear electric field frequency shift (important for next generation electric dipole moment searches) induced in confined gases by a magnetic field gradient  

E-Print Network [OSTI]

The search for particle electric dipole moments (edm) represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known $\\overrightarrow{v}\\times \\overrightarrow{E}$ field with magnetic field gradients (often referred to as the geometric phase effect (Commins, ED; Am. J. Phys. \\QTR{bf}{59}, 1077 (1991), Pendlebury, JM \\QTR{em}{et al;} Phys. Rev. \\QTR{bf}{A70}, 032102 (2004)). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic form for the velocity auto-correlation function which determines the velocity-position correlation function which in turn determines the behavior of the frequency shift (Lamoreaux, SK and Golub, R; Phys. Rev \\QTR{bf}{A71}, 032104 (2005)) and show how it depends on the operating conditions of the experiment. We also discuss some additional issues.

Authors A. L. Barabanov; R. Golub; S. K. Lamoreaux

2006-07-17T23:59:59.000Z

228

Quantum Monte Carlo calculations of electromagnetic transitions in $^8$Be with meson-exchange currents derived from chiral effective field theory  

SciTech Connect (OSTI)

We report quantum Monte Carlo calculations of electromagnetic transitions in $^8$Be. The realistic Argonne $v_{18}$ two-nucleon and Illinois-7 three-nucleon potentials are used to generate the ground state and nine excited states, with energies that are in excellent agreement with experiment. A dozen $M1$ and eight $E2$ transition matrix elements between these states are then evaluated. The $E2$ matrix elements are computed only in impulse approximation, with those transitions from broad resonant states requiring special treatment. The $M1$ matrix elements include two-body meson-exchange currents derived from chiral effective field theory, which typically contribute 20--30\\% of the total expectation value. Many of the transitions are between isospin-mixed states; the calculations are performed for isospin-pure states and then combined with the empirical mixing coefficients to compare to experiment. In general, we find that transitions between states that have the same dominant spatial symmetry are in decent agreement with experiment, but those transitions between different spatial symmetries are often significantly underpredicted.

Pastore, S. [University of South Carolina; Wiringa, Robert B. [ANL; Pieper, Steven C. [ANL; Schiavilla, Rocco [Old Dominion U., JLAB

2014-08-01T23:59:59.000Z

229

Electromagnetic wave scattering by Schwarzschild black holes  

E-Print Network [OSTI]

We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section, and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor and gravitational waves. We present a unified picture of the scattering of all massless fields for the first time.

Luís C. B. Crispino; Sam R. Dolan; Ednilton S. Oliveira

2009-05-20T23:59:59.000Z

230

Acceleration of electrons in the near field of lower hybrid frequency grills  

SciTech Connect (OSTI)

On Tore Supra, during lower hybrid (LH) current drive experiments, localized heat flux deposition is observed on plasma facing components such as the guard limiters of the LH grills or any object which is magnetically connected to the LH launching waveguides : modular low-field side limiters, ion cyclotron heating antennas, inner first wall. Similar observations have been made on the divertor plates and limiters of TdeV. In particular, by alternating the rf powers of the 2 grills of Tore Supra, it was shown that the heat flux on the tiles of the guard limiters is related to the local electric field but not with the convective power. We present here a model of acceleration of electrons in the near field of LH antennas. Results of this model are compared to experimental results.

Goniche, M. [JET Joint Undertaking, Abingdon, Oxfordshire (England); Mailloux, J.; Demers, Y.; Jacquet, P.; Bibet, P.; Froissard, P.; Rey, G.; Surle, F.; Tareb, M. [Centre canadien de fusion magnetique, Varnnes, Quebec, (Canada); Guilhem, D.; Harris, J.H. [Oak Ridge National Lab., TN (United States)

1996-09-01T23:59:59.000Z

231

Mathematical model of the seismic electromagnetic signals (SEMS) in non crystalline substances  

SciTech Connect (OSTI)

The mathematical model of seismic electromagnetic waves in non crystalline substances is developed and the solutions are discussed to show the possibility of improving the electromagnetic waves especially the electric field. The shear stress of the medium in fourth order tensor gives the equation of motion. Analytic methods are selected for the solutions written in Hansen vector form. From the simulated SEMS, the frequency of seismic waves has significant effects to the SEMS propagating characteristics. EM waves transform into SEMS or energized seismic waves. Traveling distance increases once the frequency of the seismic waves increases from 100% to 1000%. SEMS with greater seismic frequency will give seismic alike waves but greater energy is embedded by EM waves and hence further distance the waves travel.

Dennis, L. C. C.; Yahya, N.; Daud, H.; Shafie, A. [Electromagnetic cluster, Universiti Teknologi Petronas, 31750 Tronoh, Perak (Malaysia)

2012-09-26T23:59:59.000Z

232

Radio-frequency dispersive detection of donor atoms in a field-effect transistor  

SciTech Connect (OSTI)

Radio-frequency dispersive read-out can provide a useful probe to nano-scale structures, such as nano-wire devices, especially, when the implementation of charge sensing is not straightforward. Here, we demonstrate dispersive “gate-only” read-out of phosphor donors in a silicon nano-scale transistor. The technique enables access to states that are only tunnel-coupled to one contact, which is not easily achievable by other methods. This allows us to locate individual randomly placed donors in the device channel. Furthermore, the setup is naturally compatible with high bandwidth access to the probed donor states and may aid the implementation of a qubit based on coupled donors.

Verduijn, J., E-mail: a.verduijn@unsw.edu.au; Rogge, S. [Centre for Quantum Computation and Communication Technology, University of New South Wales, Sydney NSW 2052 (Australia)] [Centre for Quantum Computation and Communication Technology, University of New South Wales, Sydney NSW 2052 (Australia); Vinet, M. [CEA/LETI-MINATEC, CEA-Grenoble, 17 rue des martyrs, F-38054 Grenoble (France)] [CEA/LETI-MINATEC, CEA-Grenoble, 17 rue des martyrs, F-38054 Grenoble (France)

2014-03-10T23:59:59.000Z

233

Unmanned airborne vehicle (UAV): Flight testing and evaluation of two-channel E-field very low frequency (VLF) instrument  

SciTech Connect (OSTI)

Using VLF frequencies, transmitted by the Navy`s network, for airborne remote sensing of the earth`s electrical, magnetic characteristics was first considered by the United States Geological Survey (USGS) around the mid 1970s. The first VLF system was designed and developed by the USGS for installation and operation on a single engine, fixed wing aircraft used by the Branch of Geophysics for geophysical surveying. The system consisted of five channels. Two E-field channels with sensors consisting of a fixed vertical loaded dipole antenna with pre-amp mounted on top of the fuselage and a gyro stabilized horizontal loaded dipole antenna with pre-amp mounted on a tail boom. The three channel magnetic sensor consisted of three orthogonal coils mounted on the same gyro stabilized platform as the horizontal E-field antenna. The main features of the VLF receiver were: narrow band-width frequency selection using crystal filters, phase shifters for zeroing out system phase variances, phase-lock loops for generating real and quadrature gates, and synchronous detectors for generating real and quadrature outputs. In the mid 1990s the Branch of Geophysics designed and developed a two-channel E-field ground portable VLF system. The system was built using state-of-the-art circuit components and new concepts in circuit architecture. Small size, light weight, low power, durability, and reliability were key considerations in the design of the instrument. The primary purpose of the instrument was for collecting VLF data during ground surveys over small grid areas. Later the system was modified for installation on a Unmanned Airborne Vehicle (UAV). A series of three field trips were made to Easton, Maryland for testing and evaluating the system performance.

NONE

1998-12-01T23:59:59.000Z

234

Fiber optic probe of free electron evanescent fields in the optical frequency range Jin-Kyu So, Kevin F. MacDonald, and Nikolay I. Zheludev  

E-Print Network [OSTI]

, Kevin F. MacDonald, and Nikolay I. Zheludev Citation: Applied Physics Letters 104, 201101 (2014); doi evanescent fields in the optical frequency range Jin-Kyu So,1,a) Kevin F. MacDonald,1 and Nikolay I. Zheludev

Zheludev, Nikolay

235

Generally covariant model of a scalar field with high frequency dispersion and the cosmological horizon problem  

E-Print Network [OSTI]

Short distance structure of spacetime may show up in the form of high freqency dispersion. Although such dispersion is not locally Lorentz invariant, we show in a scalar field model how it can nevertheless be incorporated into a generally covariant metric theory of gravity provided the locally preferred frame is dynamical. We evaluate the resulting energy-momentum tensor and compute its expectation value for a quantum field in a thermal state. The equation of state differs at high temperatures from the usual one, but not by enough to impact the problems of a hot big bang cosmology. We show that a superluminal dispersion relation can solve the horizon problem via superluminal equilibration, however it cannot do so while remaining outside the Planck regime unless the dispersion relation is artificially chosen to have a rather steep dependence on wavevector.

Ted Jacobson; David Mattingly

2000-09-11T23:59:59.000Z

236

Plasma Frequency Shift Due to a Slowly Rotating Compact Star  

E-Print Network [OSTI]

We investigate the effects of a slowly rotating compact gravitational source on electron oscillations in a homogeneous electrically neutral plasma in the absence of an external electric or magnetic field. Neglecting the random thermal motion of the electrons we assume the gravitoelectromagnetic approximation to the general theory of relativity for the gravitational field. It is shown that there is a shift in the plasma frequency and hence in the dielectric constant of the plasma due to the gravitomagnetic force. We also give estimates for the difference in the frequency of radially transmitted electromagnetic signals for typical compact star candidates.

Babur M. Mirza; Hamid Saleem

2005-05-10T23:59:59.000Z

237

Electromagnetically induced transparency in mechanical effects of light  

SciTech Connect (OSTI)

We consider the dynamical behavior of a nanomechanical mirror in a high-quality cavity under the action of a coupling laser and a probe laser. We demonstrate the existence of the analog of electromagnetically induced transparency (EIT) in the output field at the probe frequency. Our calculations show explicitly the origin of EIT-like dips as well as the characteristic changes in dispersion from anomalous to normal in the range where EIT dips occur. Remarkably the pump-probe response for the optomechanical system shares all the features of the {Lambda} system as discovered by Harris and collaborators.

Agarwal, G. S.; Huang, Sumei [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

2010-04-15T23:59:59.000Z

238

Coherent control and giant enhancement of multiphoton ionization and high-order-harmonic generation driven by intense frequency-comb laser fields: An ab initio theoretical investigation  

E-Print Network [OSTI]

the intensity of the driving frequency-comb laser fields. However, the two-level model does not take into account the effects of multilevel structure and ionization, which are inherent in real atomic and/or molecular systems driven by intense laser fields... function. In general, the carrier frequency ?c is not necessarily one of the comb frequencies nor does it equal ?0. Due to the incommensuration between the time period (=2?/?c) of the carrier wave and the time interval ? of the pulse envelope, there is a...

Chu, Shih-I; Zhao, Di; Li, Fu-li

2013-04-11T23:59:59.000Z

239

Simulation of the frequency dispersion of effective dielectric characteristics of composite materials  

SciTech Connect (OSTI)

The problems of calculating the effective dielectric characteristics of polycrystalline materials are considered taking into account the frequency dependence of the characteristics of individual components. The effective characteristics of ceramics such as lead zirconate-titanate with titanium and zirconium oxide, metal lead, and water inclusions are calculated in the Maxwell-Garnett and Bruggeman approximations. The dependences of the effective dielectric characteristics on the inclusion concentration and applied electromagnetic-field frequency are obtained.

Yakovlev, V. B.; Bardushkin, V. V.; Lavrov, I. V., E-mail: iglavr@mail.ru; Yakovleva, E. N. [National Research University of Electronic Technology (MIET) (Russian Federation)

2014-12-15T23:59:59.000Z

240

Structurally Electromagnetic Formation Flight (EMFF)  

E-Print Network [OSTI]

Structurally connected secondary mirror EMFF secondary mirror EMFF Design Electromagnetic Formation for a smaller, simpler system. µEMFF investigates the use of conventional conductors, capacitors, and solar propellants that often limit lifetime, the EMFF system uses solar power to energize a magnetic field

de Weck, Olivier L.

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Synchrotron Radiation at Radio Frequencies from Cosmic Ray Air Showers  

E-Print Network [OSTI]

We review some of the properties of extensive cosmic ray air showers and describe a simple model of the radio-frequency radiation generated by shower electrons and positrons as they bend in the Earth's magnetic field. We perform simulations by calculating the trajectory and radiation of a few thousand charged shower particles. The results are then transformed to predict the strength and polarization of the electromagnetic radiation emitted by the whole shower.

Denis A. Suprun; Peter W. Gorham; Jonathan L. Rosner

2003-06-06T23:59:59.000Z

242

Synchrotron Radiation at Radio Frequencies from Cosmic Ray Air Showers  

E-Print Network [OSTI]

We review some of the properties of extensive cosmic ray air showers and describe a simple model of the radio-frequency radiation generated by shower electrons and positrons as they bend in the Earth's magnetic field. We perform simulations by calculating the trajectory and radiation of a few thousand charged shower particles. The results are then transformed to predict the strength and polarization of the electromagnetic radiation emitted by the whole shower.

Suprun, D A; Rosner, Jonathan L; Suprun, Denis A.; Gorham, Peter W.; Rosner, Jonathan L.

2003-01-01T23:59:59.000Z

243

Electromagnetism on Anisotropic Fractals  

E-Print Network [OSTI]

We derive basic equations of electromagnetic fields in fractal media which are specified by three indepedent fractal dimensions {\\alpha}_{i} in the respective directions x_{i} (i=1,2,3) of the Cartesian space in which the fractal is embedded. To grasp the generally anisotropic structure of a fractal, we employ the product measure, so that the global forms of governing equations may be cast in forms involving conventional (integer-order) integrals, while the local forms are expressed through partial differential equations with derivatives of integer order but containing coefficients involving the {\\alpha}_{i}'s. First, a formulation based on product measures is shown to satisfy the four basic identities of vector calculus. This allows a generalization of the Green-Gauss and Stokes theorems as well as the charge conservation equation on anisotropic fractals. Then, pursuing the conceptual approach, we derive the Faraday and Amp\\`ere laws for such fractal media, which, along with two auxiliary null-divergence conditions, effectively give the modified Maxwell equations. Proceeding on a separate track, we employ a variational principle for electromagnetic fields, appropriately adapted to fractal media, to independently derive the same forms of these two laws. It is next found that the parabolic (for a conducting medium) and the hyperbolic (for a dielectric medium) equations involve modified gradient operators, while the Poynting vector has the same form as in the non-fractal case. Finally, Maxwell's electromagnetic stress tensor is reformulated for fractal systems. In all the cases, the derived equations for fractal media depend explicitly on fractal dimensions and reduce to conventional forms for continuous media with Euclidean geometries upon setting the dimensions to integers.

Martin Ostoja-Starzewski

2011-06-08T23:59:59.000Z

244

Characterization and performance of a field aligned ion cyclotron range of frequency antenna in Alcator C-Mod  

SciTech Connect (OSTI)

Ion cyclotron range of frequency (ICRF) heating is expected to provide auxiliary heating for ITER and future fusion reactors where high Z metallic plasma facing components (PFCs) are being considered. Impurity contamination linked to ICRF antenna operation remains a major challenge particularly for devices with high Z metallic PFCs. Here, we report on an experimental investigation to test whether a field aligned (FA) antenna can reduce impurity contamination and impurity sources. We compare the modification of the scrape of layer (SOL) plasma potential of the FA antenna to a conventional, toroidally aligned (TA) antenna, in order to explore the underlying physics governing impurity contamination linked to ICRF heating. The FA antenna is a 4-strap ICRF antenna where the current straps and antenna enclosure sides are perpendicular to the total magnetic field while the Faraday screen rods are parallel to the total magnetic field. In principle, alignment with respect to the total magnetic field minimizes integrated E|| (electric field along a magnetic field line) via symmetry. A finite element method RF antenna model coupled to a cold plasma model verifies that the integrated E|| should be reduced for all antenna phases. Monopole phasing in particular is expected to have the lowest integrated E||. Consistent with expectations, we observed that the impurity contamination and impurity source at the FA antenna are reduced compared to the TA antenna. In both L and H-mode discharges, the radiated power is 20%–30% lower for a FA-antenna heated discharge than a discharge heated with the TA-antennas. However, inconsistent with expectations, we observe RF induced plasma potentials (via gas-puff imaging and emissive probes to be nearly identical for FA and TA antennas when operated in dipole phasing). Moreover, the highest levels of RF-induced plasma potentials are observed using monopole phasing with the FA antenna. Thus, while impurity contamination and sources are indeed reduced with the FA antenna configuration, the mechanism determining the SOL plasma potential in the presence of ICRF and its impact on impurity contamination and sources remains to be understood.

Wukitch, S. J.; Garrett, M. L.; Ochoukov, R.; Terry, J. L.; Hubbard, A.; Labombard, B.; Lau, C.; Lin, Y.; Lipschultz, B.; Miller, D.; Reinke, M. L.; Whyte, D. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)] [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Collaboration: Alcator C-Mod Team

2013-05-15T23:59:59.000Z

245

Electromagnetic scattering and induction models for spheroidal geometries  

E-Print Network [OSTI]

Electromagnetic scattering from a medium containing randomly distributed discrete dielectric spheroidal inclusions is studied. Also, the broadband magnetoquasistatic solution for the induced magnetic field from a conducting ...

Barrowes, Benjamin E., 1973-

2004-01-01T23:59:59.000Z

246

Electromagnetic wave scattering by small perfectly conducting particles and applications  

E-Print Network [OSTI]

A formula for the electromagnetic (EM) field in the medium, in which many small perfectly conducting particles of an arbitrary shape are distributed, is derived.

Alexander G. Ramm

2014-02-13T23:59:59.000Z

247

Unification of Electromagnetism and Gravitation in the Framework of General Geometry  

E-Print Network [OSTI]

A new geometry, called General geometry, is constructed. It is proven that its the most simplest special case is geometry underlying Electromagnetism. Another special case is Riemannian geometry. Action for electromagnetic field and Maxwell equations are derived from curvature function of geometry underlying Electromagnetism. It is shown that equation of motion for a particle interacting with electromagnetic field coincides exactly with equation for geodesics of geometry underlying Electromagnetism. It is also shown that Electromagnetism can not be geometrized in the framework of Riemannian geometry. Using General Geometry we propose a unified model of electromagnetism and gravitation which reproduces Electromagnetism and Gravitation and predicts that electromagnetic field is a source for gravitational field. This theory is formulated in four dimensional spacetime and does not contain additional fields.

Shervgi Shahverdiyev

2005-07-05T23:59:59.000Z

248

SOLAR NANTENNA ELECTROMAGNETIC COLLECTORS  

SciTech Connect (OSTI)

This research explores a new efficient approach for producing electricity from the abundant energy of the sun. A nanoantenna electromagnetic collector (NEC) has been designed, prototyped, and tested. Proof of concept has been validated. The device targets mid-infrared wavelengths where conventional photovoltaic (PV) solar cells do not respond but is abundant in solar energy. The initial concept of designing NEC antennas was based on scaling of radio frequency antenna theory. This approach has proven unsuccessful by many due to not fully understanding and accounting for the optical behavior of materials in the THz region. Also until recent years the nanofabrication methods were not available to fabricate the optical antenna elements. We have addressed and overcome both technology barriers. Several factors were critical in successful implementation of NEC including: 1) frequency-dependent modeling of antenna elements, 2) selection of materials with proper THz properties and 3) novel manufacturing methods that enable economical large-scale manufacturing. The work represents an important step toward the ultimate realization of a low-cost device that will collect as well as convert this radiation into electricity, which will lead to a wide spectrum, high conversion efficiency, and low cost solution to complement conventional PVs.

Steven D. Novack; Dale K. Kotter; Dennis Slafer; Patrick Pinhero

2008-08-01T23:59:59.000Z

249

Investigation of electromagnetic welding  

E-Print Network [OSTI]

We propose several methodologies to study and optimize the electromagnetic process for Electromagnetic Forming (EMF) and Welding (EMW), thereby lowering the necessary process energy up to a factor of three and lengthening ...

Pressl, Daniel G. (Daniel Gerd)

2009-01-01T23:59:59.000Z

250

Electromagnetic properties of neutrinos  

E-Print Network [OSTI]

A short review on electromagnetic properties of neutrinos is presented. In spite of many efforts in the theoretical and experimental studies of neutrino electromagnetic properties, they still remain one of the main puzzles related to neutrinos.

Carlo Giunti; Alexander Studenikin

2010-06-08T23:59:59.000Z

251

ON THE INFLUENCE OF THE GEOMETRY ON SKIN EFFECT IN ELECTROMAGNETISM  

E-Print Network [OSTI]

ON THE INFLUENCE OF THE GEOMETRY ON SKIN EFFECT IN ELECTROMAGNETISM GABRIEL CALOZ, MONIQUE DAUGE, ERWAN FAOU, VICTOR P´ERON ABSTRACT. We consider the equations of electromagnetism set on a domain made in electromagnetism. This effect describes the rapid decay of electromagnetic fields with depth inside a metallic

Dauge, Monique

252

Electromagnetic modeling of the energy distribution of a metallic cylindrical parabolic reflector covered with a magnetized plasma layer  

SciTech Connect (OSTI)

The energy distribution along the focal axis of a long metallic cylindrical parabolic reflector with a plasma layer on its surface in the presence of an external magnetic field is investigated. The effects of some physical parameters, such as the plasma frequency, the wave frequency and the thickness of plasma layer on the energy distribution and the reflected and transmitted electromagnetic fields, are simulated. These investigations for both S- and P-polarizations have been done separately. It is found that the maximum value of the reflected intensity increases by increasing the incident wave frequency and by decreasing the plasma layer thickness and the plasma frequency for both polarizations. Furthermore, the results show that the increase of the magnetic field strength can cause an increase in the reflected intensity for S-polarization and a slight decrease for P-polarization.

Niknam, A. R., E-mail: a-niknam@sbu.ac.ir; Khajehmirzaei, M. R. [Laser and Plasma Research Institute, Shahid Beheshti University, GC, Tehran (Iran, Islamic Republic of); Davoudi-Rahaghi, B.; Rahmani, Z.; Jazi, B.; Abdoli-Arani, A. [Department of Laser and Photonics, Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of)

2014-07-15T23:59:59.000Z

253

Control of the Lamb shift by a driving field  

E-Print Network [OSTI]

A unitary transformation approach is used to study the energy level shift of the atom coupled to both a vacuum electromagnetic field and a driving laser. The Lamb shift of the energy levels is shown to depend on the Rabi frequency and the detuning...

Yang, Shuai; Zheng, Hang; Hong, Ran; Zhu, Shi-Yao; Zubairy, M. Suhail

2010-01-01T23:59:59.000Z

254

Electromagnetically-Induced Frame-Dragging around Astrophysical Objects  

E-Print Network [OSTI]

Frame dragging (Lense-Thirring effect) is generally associated with rotating astrophysical objects. However, it can also be generated by electromagnetic fields if electric and magnetic fields are simultaneously present. In most models of astrophysical objects, macroscopic charge neutrality is assumed and the entire electromagnetic field is characterized in terms of a magnetic dipole component. Hence, the purely electromagnetic contribution to the frame dragging vanishes. However, strange stars may posses independent electric dipole and neutron stars independent electric quadrupole moments that may lead to the presence of purely electromagnetic contributions to the frame dragging. Moreover, recent observations have shown that in stars with strong electromagnetic fields, the magnetic quadrupole may have a significant contribution to the dynamics of stellar processes. As an attempt to characterized and quantify the effect of electromagnetic frame-dragging in this kind of astrophysical objects, an analytic soluti...

Ruiz, Andrés F Gutiérrez

2015-01-01T23:59:59.000Z

255

Electromagnetic Measurements at RHIC  

E-Print Network [OSTI]

Electromagnetic Measurements at RHIC Hideki Hamagaki Center for Nuclear Study University of Tokyo #12;2/10/2005 "Electromagnetic measurements at RHIC"@ICPAQGP 05 Hideki Hamagaki 2 Prologue · EM probe and where they are produced; #12;2/10/2005 "Electromagnetic measurements at RHIC"@ICPAQGP 05 Hideki Hamagaki

Hamagaki, Hideki

256

Electromagnetic Abdulaziz Hanif  

E-Print Network [OSTI]

Electromagnetic Propulsion Abdulaziz Hanif Electrical Engineering Department King Fahd University of spacecraft, which would be jolted through space by electromagnets, could take us farther than any of these other methods. When cooled to extremely low temperatures, electromagnets demonstrate an unusual behavior

Masoudi, Husain M.

257

Electromagnetic Measurements at RHIC  

E-Print Network [OSTI]

Electromagnetic Measurements at RHIC Hideki Hamagaki Center for Nuclear Study Graduate School of Science the University of Tokyo #12;2006/06/29 "Electromagnetic measurements at RHIC"@ATHIC 2006 Hideki;2006/06/29 "Electromagnetic measurements at RHIC"@ATHIC 2006 Hideki Hamagaki 3 Prologue ­ scope of EM measurements · EM

Hamagaki, Hideki

258

Electromagnetic space-time crystals. II. Fractal computational approach  

E-Print Network [OSTI]

A fractal approach to numerical analysis of electromagnetic space-time crystals, created by three standing plane harmonic waves with mutually orthogonal phase planes and the same frequency, is presented. Finite models of electromagnetic crystals are introduced, which make possible to obtain various approximate solutions of the Dirac equation. A criterion for evaluating accuracy of these approximate solutions is suggested.

G. N. Borzdov

2014-10-20T23:59:59.000Z

259

Electromagnetic waves, gravitational coupling and duality analysis  

E-Print Network [OSTI]

In this letter we introduce a particular solution for parallel electric and magnetic fields, in a gravitational background, which satisfy free-wave equations and the phenomenology suggested by astrophysical plasma physics. These free-wave equations are computed such that the electric field does not induce the magnetic field and vice-versa. In a gravitational field, we analyze the Maxwell equations and the corresponding electromagnetic waves. A continuity equation is presented. A commutative and noncommutative analysis of the electromagnetic duality is described.

E. M. C. Abreu; C. Pinheiro; S. A. Diniz; F. C. Khanna

2005-10-27T23:59:59.000Z

260

A strong permanent magnet-assisted electromagnetic undulator  

DOE Patents [OSTI]

This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles. 4 figs.

Halbach, K.

1987-01-30T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Interaction of biological systems with static and ELF electric and magnetic fields  

SciTech Connect (OSTI)

Although background levels of atmospheric electric and geomagnetic field levels are extremely low, over the past several decades, human beings and other life forms on this planet have been subjected to a dramatically changing electromagnetic milieu. An exponential increase in exposure to electromagnetic fields has occurred, largely because of such technological advances as the growth of electrical power generation and transmission systems, the increased use of wireless communications, and the use of radar. In addition, electromagnetic field generating devices have proliferated in industrial plants, office buildings, homes, public transportation systems, and elsewhere. Although significant increases have occurred in electromagnetic field strenghths spanning all frequency ranges, this symposium addresses only the impact of these fields at static and extremely low frequencies (ELF), primarily 50 and 60 Hz. This volume contains the proceedings of the symposium entitled /open quotes/Interaction of biological systems with static and ELF electric and magnetic fields/close quotes/. The purpose of the symposium was to provide a forum for discussions of all aspects of research on the interaction of static and ELF electromagnetic fields with biological systems. These systems include simple biophysical models, cell and organ preparations, whole animals, and man. Dosimetry, exposure system design, and artifacts in ELF bioeffects research were also addressed, along with current investigations that examine fundamental mechanisms of interactions between the fields and biological processes. Papers are indexed separately.

Anderson, L.E.; Kelman, B.J.; Weigel, R.J. (eds.)

1987-01-01T23:59:59.000Z

262

Frequency-Selective Near-Field Radiative Heat Transfer between Photonic Crystal Slabs: A Computational Approach for Arbitrary Geometries and Materials  

E-Print Network [OSTI]

of energy from a hot to a cold body is well known to be enhanced (even exceeding the black- body limit) whenFrequency-Selective Near-Field Radiative Heat Transfer between Photonic Crystal Slabs of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA 3 Department

Soljaèiæ, Marin

263

Electro-Optical Sensing Apparatus and Method for Characterizing Free-Space Electromagnetic Radiation  

DOE Patents [OSTI]

Apparatus and methods for characterizing free-space electromagnetic energy, and in particular, apparatus/method suitable for real-time two-dimensional far-infrared imaging applications are presented. The sensing technique is based on a non-linear coupling between a low-frequency electric field and a laser beam in an electro-optic crystal. In addition to a practical counter-propagating sensing technique, a co-linear approach is described which provides longer radiated field--optical beam interaction length, thereby making imaging applications practical.

Zhang, Xi-Cheng; Libelo, Louis Francis; Wu, Qi

1999-09-14T23:59:59.000Z

264

Velocity damper for electromagnetically levitated materials  

DOE Patents [OSTI]

A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material is disclosed. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation. 1 fig.

Fox, R.J.

1994-06-07T23:59:59.000Z

265

Spinors and pre-metric electromagnetism  

E-Print Network [OSTI]

The basic concepts of the formulation of Maxwellian electromagnetism in the absence of a Minkowski scalar product on spacetime are summarized, with particular emphasis on the way that the electromagnetic constitutive law on the space of bivectors over spacetime supplants the role of the Minkowski scalar product on spacetime itself. The complex geometry of the space of bivectors is summarized, with the intent of showing how an isomorphic copy of the Lorentz group appears in that context. The use of complex 3-spinors to represent electromagnetic fields is then discussed, as well as the expansion of scope that the more general complex projective geometry of the space of bivectors suggests.

David Delphenich

2005-12-22T23:59:59.000Z

266

On the Axioms of Topological Electromagnetism  

E-Print Network [OSTI]

The axioms of topological electromagnetism are refined by the introduction of the de Rham homology of k-vector fields on orientable manifolds and the use of Poincare duality in place of Hodge duality. The central problem of defining the electromagnetic constitutive law is elaborated upon in the linear and nonlinear cases. The manner by which the spacetime metric might follow from the constitutive law is examined in the linear case. The possibility that the intersection form of the spacetime manifold might play a role in defining a topological basis for the constitutive law is explored. The manner by which wave motion might follow from the electromagnetic structure is also discussed.

D. H. Delphenich

2003-12-14T23:59:59.000Z

267

Effects of Electromagnetic Fields on Fish and Invertebrates Task 2.1.3: Effects on Aquatic Organisms Fiscal Year 2012 Progress Report Environmental Effects of Marine and Hydrokinetic Energy  

SciTech Connect (OSTI)

Energy generated by the world’s oceans and rivers offers the potential to make substantial contributions to the domestic and global renewable energy supply. However, the marine and hydrokinetic (MHK) energy industry faces challenges related to siting, permitting, construction, and operation of pilotand commercial-scale facilities. One of the challenges is to understand the potential effects to marine organisms from electromagnetic fields, which are produced as a by-product of transmitting power from offshore to onshore locations through underwater transmission cables. This report documents the progress of the third year of research (fiscal year 2012) to investigate environmental issues associated with marine and hydrokinetic energy (MHK) generation. This work was conducted by Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy’s (DOE’s) Office of Energy Efficiency and Renewable Energy (EERE) Wind and Water Technologies Office. The report addresses the effects of electromagnetic fields (EMFs) on selected marine species where significant knowledge gaps exist. The species studied this fiscal year included one fish and two crustacean species: the Atlantic halibut (Hippoglossus hippoglossus), Dungeness crab (Metacarcinus magister), and American lobster (Homarus americanus).

Woodruff, Dana L.; Cullinan, Valerie I.; Copping, Andrea E.; Marshall, Kathryn E.

2013-05-20T23:59:59.000Z

268

A current driven electromagnetic mode in sheared and toroidal configurations  

E-Print Network [OSTI]

The induced electric field in a tokamak drives a parallel electron current flow. In an inhomogeneous, finite beta plasma, when this electron flow is comparable to the ion thermal speed, the Alfven mode wave solutions of the electromagnetic gyrokinetic equation can become nearly purely growing kink modes. Using the new "low-flow" version of the gyrokinetic code GS2 developed for momentum transport studies [Barnes et al 2013 Phys. Rev. Lett. 111, 055005], we are able to model the effect of the induced parallel electric field on the electron distribution to study the destabilizing influence of current on stability. We identify high mode number kink modes in GS2 simulations and make comparisons to analytical theory in sheared magnetic geometry. We demonstrate reassuring agreement with analytical results both in terms of parametric dependences of mode frequencies and growth rates, and regarding the radial mode structure.

Pusztai, István; Parra, Felix I; Barnes, Michael

2013-01-01T23:59:59.000Z

269

Enhanced ULF electromagnetic activity detected by DEMETER above seismogenic regions  

E-Print Network [OSTI]

In this paper we present results of a comparison between ultra low frequency (ULF) electromagnetic (EM) radiation, recorded by an electric field instrument (ICE) onboard the satellite DEMETER in the topside ionosphere, and the seismicity of regions with high and lower seiismic activity. In particular we evaluated the energy variations of the ULF Ez-electric field component during a period of four years (2006-2009), in order to examine check the possible relation of ULF EM radiation with seismogenic regions located in central America, Indonesia, Eastern Mediterranean Basin and Greece. As a tool of evaluating the ULF Ez energy variations we used Singular Spectrum Analysis (SSA) techniques. The results of our analysis clearly show a significant increase of the ULF EM energy emmited from regions of highest seismic activity at the tectonic plates boundaries. We interpret these results as suggesting that the highest ULF EM energy detected in the topside ionosphere is originated from seismic processes within Earth's...

Athanasiou, M; David, C; Anagnostopoulos, G

2013-01-01T23:59:59.000Z

270

Thermal front tracking with cross borehole electromagnetic imaging: Task 32 of Annex 4 of the implementing agreement  

SciTech Connect (OSTI)

Field experiments at the Texaco Kern River Field were conducted to identify optimum transmission frequencies and assess the electromagnetic interference problems present in the system. We concluded that the transmitter must be operated below 3 MHz for attenuation measurements to be in the conduction regime. Operation in the conduction regime is necessary if we are to correlate images to independent measurements such as the dual induction logs. We also concluded that electromagnetic interference problems become more severe as the frequency is lowered. We are currently designing a downhole active transmitter that will operate at 2 MHz. This frequency is low enough to be in the conduction regime and to increase our transmission distance capability, but high enough so that we can still drive a 1 or 2 meter antenna. By driving the antenna with a downhole oscillator we dramatically reduce the chance of electromagnetic interference pathways. Future plans are to test the transmitter at the Texaco field site and demonstrate correlation to induction logs. This will be followed by a brine tracing experiment at the same site. We will then move our equipment to a new pilot test site for a substantial series of cooperative experiments with Texaco. 5 refs., 11 figs.

Harben, P.E.; Pihlman, M.

1988-04-01T23:59:59.000Z

271

Electromagnetic and spin polarisabilities in lattice QCD  

E-Print Network [OSTI]

We discuss the extraction of the electromagnetic and spin polarisabilities of nucleons from lattice QCD. We show that the external field method can be used to measure all the electromagnetic and spin polarisabilities including those of charged particles. We then turn to the extrapolations required to connect such calculations to experiment in the context of chiral perturbation theory, finding a strong dependence on the lattice volume and quark masses.

W. Detmold; B. C. Tiburzi; A. Walker-Loud

2006-10-02T23:59:59.000Z

272

Extremely high frequency RF effects on electronics.  

SciTech Connect (OSTI)

The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

2012-01-01T23:59:59.000Z

273

Quantum modulation against electromagnetic interference  

E-Print Network [OSTI]

Periodic signals in electrical and electronic equipment can cause interference in nearby devices. Randomized modulation of those signals spreads their energy through the frequency spectrum and can help to mitigate electromagnetic interference problems. The inherently random nature of quantum phenomena makes them a good control signal. I present a quantum modulation method based on the random statistics of quantum light. The paper describes pulse width modulation schemes where a Poissonian light source acts as a random control that spreads the energy of the potential interfering signals. I give an example application for switching-mode power supplies and comment the further possibilities of the method.

Juan Carlos Garcia-Escartin

2014-11-26T23:59:59.000Z

274

Unbalanced electromagnetic forces  

E-Print Network [OSTI]

) . I :, jazdz g (Member) (Member) August 1974 -" ~ 5:. -. 62 ABSTRACT Unbalanced Electromagnetic Forces (August 1974) Craig Martin Hansen, B. S. , Texas A&M University Directed by: Dr. Attilio J. Giaroia Electromagnetic forces from moving... be deduced from the history of the development of an under- standing of electromagnetic forces. This is a relatively short history (starting in the late 1800's) filled with misunderstandings and pre]udices. This history can be divided into two eras: non...

Hansen, Craig Martin

2012-06-07T23:59:59.000Z

275

Relativistic approach to electromagnetic imaging  

E-Print Network [OSTI]

A novel imaging principle based on the interaction of electromagnetic waves with a beam of relativistic electrons is proposed. Wave-particle interaction is assumed to take place in a small spatial domain, so that each electron is only briefly accelerated by the incident field. In the one-dimensional case the spatial distribution of the source density can be directly observed in the temporal spectrum of the scattered field. Whereas, in the two-dimensional case the relation between the source and the spectrum is shown to be approximately the Radon transform.

Budko, N

2004-01-01T23:59:59.000Z

276

Relativistic approach to electromagnetic imaging  

E-Print Network [OSTI]

A novel imaging principle based on the interaction of electromagnetic waves with a beam of relativistic electrons is proposed. Wave-particle interaction is assumed to take place in a small spatial domain, so that each electron is only briefly accelerated by the incident field. In the one-dimensional case the spatial distribution of the source density can be directly observed in the temporal spectrum of the scattered field. Whereas, in the two-dimensional case the relation between the source and the spectrum is shown to be approximately the Radon transform.

Neil Budko

2004-03-11T23:59:59.000Z

277

Electromagnetic properties of massive neutrinos  

SciTech Connect (OSTI)

The vertex function for a virtual massive neutrino is calculated in the limit of soft real photons. A method based on employing the neutrino self-energy operator in a weak external electromagnetic field in the approximation linear in the field is developed in order to render this calculation of the vertex function convenient. It is shown that the electric charge and the electric dipole moment of the real neutrino are zero; only the magnetic moment is nonzero for massive neutrinos. A fourth-generation heavy neutrino of mass not less than half of the Z-boson mass is considered as a massive neutrino.

Dobrynina, A. A., E-mail: aleksandradobrynina@rambler.ru; Mikheev, N. V.; Narynskaya, E. N. [Demidov Yaroslavl State University (Russian Federation)] [Demidov Yaroslavl State University (Russian Federation)

2013-10-15T23:59:59.000Z

278

Meson electromagnetic form factors  

E-Print Network [OSTI]

The electromagnetic structure of the pseudoscalar meson nonet is completely described by the sophisticated Unitary&Analytic model, respecting all known theoretical properties of the corresponding form factors.

Stanislav Dubnicka; Anna Z. Dubnickova

2012-10-23T23:59:59.000Z

279

Electromagnetically driven peristaltic pump  

DOE Patents [OSTI]

An electromagnetic peristaltic pump apparatus may comprise a main body section having an inlet end and an outlet end and a flexible membrane which divides the main body section into a first cavity and a second cavity. The first cavity is in fluid communication with the inlet and outlet ends of the main body section. The second cavity is not in fluid communication with the first cavity and contains an electrically conductive fluid. The second cavity includes a plurality of electrodes which are positioned within the second cavity generally adjacent the flexible membrane. A magnetic field generator produces a magnetic field having a plurality of flux lines at least some of which are contained within the second cavity of the main body section and which are oriented generally parallel to a flow direction in which a material flows between the inlet and outlet ends of the main body section. A control system selectively places a voltage potential across selected ones of the plurality of electrodes to deflect the flexible membrane in a wave-like manner to move material contained in the first cavity between the inlet and outlet ends of the main body section.

Marshall, Douglas W. (Blackfoot, ID)

2000-01-01T23:59:59.000Z

280

The nature of electromagnetic energy  

E-Print Network [OSTI]

The nature of the electromagnetic (EM) energy for general charge and current distributions is analyzed. There are two well known forms for calculating EM energy as the integral over all space of either the electromagnetic fields: $u_{\\bf EB}=({\\bf E\\bcdot D+B\\bcdot H})/8\\pi$, or the electromagnetic potentials and charge-current densities: $u_{\\rho{\\bf A}}=1/2(\\rho\\phi+{\\bf j\\bcdot A})$. We discuss the appropriate use of each of these forms in calculating the total EM energy and the EM energy within a limited volume. We conclude that only the form $u_{\\bf EB}$ can be considered as a suitable EM energy density, while either form can be integrated to find the total EM energy. However, bounding surface integrals (if they don't vanish) must be included when using the $u_{\\bf EB}$ form. Including these surface integrals resolves some seeming paradoxes in the energy of electric or magnetic dipoles in uniform fields

Jerrold Franklin

2007-07-23T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

A tunable metamaterial dependent on electric field at terahertz with barium strontium titanate thin film  

SciTech Connect (OSTI)

A tunable metamaterial with resonance frequency at terahertz (THz) was developed. Electromagnetic response of the metamaterial was characterized with THz time domain spectrometer at various direct current electric fields. The resonance frequency increased monotonously with increasing electric field. The finite difference time domain method was used to simulate the transmission spectra of the metamaterial at THz frequencies. By comparing the simulated resonance frequency with the experimental curve, dielectric property of the Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3} (BST60) thin film at THz, over 0–33?kV/cm, was evaluated.

Bian, Yanlong; Zhai, Jiwei, E-mail: apzhai@tongji.edu.cn [Function Materials Research Laboratory, Tongji University, Shanghai 200092 (China); Wu, Chao; Li, Hongqiang [Department of Physics Science and Engineering, Tongji University, Shanghai 200092 (China)

2014-01-27T23:59:59.000Z

282

Detailed discussion of a linear electric field frequency shift (important for next generation) electric dipole moment searches) induced in confined gases by a magnetic field gradient: Implications for electric dipole moment experiments (II)  

E-Print Network [OSTI]

The search for particle electric dipole moments represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known E x v field with magnetic field gradients (often referred to as the geometric phase effect [9,10]). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic model for the correlation function which determines the behavior of the frequency shift [11], and show in detail how it depends on the operating conditions of the experiment. We also propose a method to directly measure ths correlation function under the exact conditions of a given experiment.

A. L. Barabanov; R. Golub; S. K. Lamoreaux

2005-12-20T23:59:59.000Z

283

Simulation of the influence high-frequency (2 MHz) capacitive gas discharge and magnetic field on the plasma sheath near a surface in hypersonic gas flow  

SciTech Connect (OSTI)

The plasma sheath near the surface of a hypersonic aircraft formed under associative ionization behind the shock front shields the transmission and reception of radio signals. Using two-dimensional kinetic particle-in-cell simulations, we consider the change in plasma-sheath parameters near a flat surface in a hypersonic flow under the action of electrical and magnetic fields. The combined action of a high-frequency 2-MHz capacitive discharge, a constant voltage, and a magnetic field on the plasma sheath allows the local electron density to be reduced manyfold.

Schweigert, I. V., E-mail: ischweig@itam.nsc.ru [Russian Academy of Sciences, Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch (Russian Federation)

2012-08-15T23:59:59.000Z

284

NISTHB 150-11 Electromagnetic  

E-Print Network [OSTI]

NISTHB 150-11 NVLAP Electromagnetic Compatibility and Telecommunications Bethany Hackett Bradley. #12;NISTHB 150-11 NVLAP Electromagnetic Compatibility and Telecommunications Bethany Hackett Bradley Programs Dennis Camell Electromagnetics Division Physical Measurement Laboratory http://dx.doi.org/10

285

Compact betatron with four controlling-field periodicity elements  

SciTech Connect (OSTI)

A compact 3-MeV betatron is described. The electromagnet of the betatron uses removable four-element poles, which form a magnetic field with azimuthal variation. The betatron accelerates 2 x 10/sup 10/ particles per cycle. The cycle repetition frequency is up to 400 Hz. The radius of the equilibrium orbit is 4.5 cm. The maximum interpole gap is 4 cm. The depth of magnetic-field variation on the equilibrium radius is 0.15.

Chakhlov, V.L.; Pushin, V.S.; Burov, G.I.; Zvontsov, A.A.; Zvorygin, V.P.; Zrelov, Yu.D.

1987-01-01T23:59:59.000Z

286

Tunability enhanced electromagnetic wiggler  

DOE Patents [OSTI]

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.

Schlueter, R.D.; Deis, G.A.

1992-03-24T23:59:59.000Z

287

High-frequency absorption of the dynamic mixed state in the surface superconductivity region  

SciTech Connect (OSTI)

We analyze the absorption of a high-frequency electromagnetic field in the type II superconductor Pb{sub 0.8}In{sub 0.2} in magnetic fields H{sub c2} < H < H{sub c3}. The absorption component proportional to the rate of variation of the external magnetic field is detected. We assume that this absorption component is associated with the dynamic mixed state of the superconducting shell containing 2D magnetic flux vortices (Kulik vortices). The motion of these vortices under the action of the critical current ensures the required difference between the external and internal magnetic inductions of the superconducting shell upon a change in the external magnetic field. This model correctly describes the observed behavior of absorption of rf electromagnetic radiation.

Berezin, V. A., E-mail: berezin@iptm.ru; Tulin, V. A., E-mail: tulin@iptm.ru [Russian Academy of Sciences, Institute of Microelectronics Technology and High-Purity Materials (Russian Federation)

2013-03-15T23:59:59.000Z

288

A universal electromagnetic energy conversion adapter based on a metamaterial absorber  

E-Print Network [OSTI]

On the heels of metamaterial absorbers (MAs) which produce near perfect electromagnetic (EM) absorption and emission, we propose a universal electromagnetic energy conversion adapter (UEECA) based on MA. By choosing the appropriate energy converting sensors, the UEECA is able to achieve near 100% signal transfer ratio between EM energy and various forms of energy such as thermal, DC electric, or higher harmonic EM energy. The inherited subwavelength dimension and the EM field intensity enhancement can further empower UEECA in many critical applications such as energy harvesting, solar cell, and nonlinear optics. The principle of UEECA is understood with a transmission line model, which further provides a design strategy that can incorporate a variety of energy conversion devices. The concept is experimentally validated at a microwave frequency with a signal transfer ratio of 96% by choosing an RF diode as the energy converting sensor.

Xie, Yunsong; Wilson, Jeffrey D; Simons, Rainee N; Chen, Yunpeng; Xiao, John Q

2013-01-01T23:59:59.000Z

289

Measurement of Electromagnetic Parameters and FDTD Modeling of Ferrite Cores  

E-Print Network [OSTI]

Measurement of Electromagnetic Parameters and FDTD Modeling of Ferrite Cores Jianfeng Xu #1 products based on magneto-dielectric (ferrite) materials with desirable frequency responses that satisfy simulation tool that could deal with frequency- dispersive materials. An example of a ferrite material

Koledintseva, Marina Y.

290

Line geometry and electromagnetism III: groups of transformations  

E-Print Network [OSTI]

The role of linear and projective groups of transformations in line geometry and electromagnetism is examined in accordance with Klein's Erlanger Programm for geometries. The group of collineations of real projective space is chosen as the most general group, and reductions to some of its various subgroups are then detailed according to their relevance to electromagnetic fields, and especially wave-like ones.

D. H. Delphenich

2014-04-16T23:59:59.000Z

291

Merging electromagnetism with space-time metric  

E-Print Network [OSTI]

In the present work, it is shown that the electromagnetism may be directly associated to the four-dimensional space-time geometry. The starting point is an analysis of the geodesic equation of general relativity where it is verified that it contains implicitly the effects of the Coulomb and the Lorentz forces. Consequently, some components of the metric tensor are identified with the components of the four-vector electromagnetic potential. Then, it is constructed a low-field equation for the electromagnetism in the same structure of the Einstein field equations for the gravitation, relating the curvature of space-time to sources of charge and current density. In this framework, all the Maxwell equations are implicit. A proof of consistency with the framework of quantum mechanics is shown.

C. A. Duarte

2014-03-10T23:59:59.000Z

292

I. What is electromagnetic radiation and the electromagnetic spectrum?  

E-Print Network [OSTI]

i­1 I. What is electromagnetic radiation and the electromagnetic spectrum? What do light, X effects on matter. This "stuff" is called electromagnetic radiation, because it travels (radiates) and has electrical and magnetic effects. Electromagnetic radiation is the means for many of our interactions

Sitko, Michael L.

293

Field Evaluations of Low-Frequency SAFT-UT on Cast Stainless Steel and Dissimilar Metal Weld Components  

SciTech Connect (OSTI)

This report documents work performed at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, and at the Electric Power Research Institute's (EPRI) Nondestructive Examination (NDE) Center in Charlotte, North Carolina, on evalutating a low frequency ultrasonic inspection technique used for examination of cast stainless steel (CSS) and dissimilar metal (DMW) reactor piping components. The technique uses a zone-focused, multi-incident angle, low frequency (250-450 kHz) inspection protocol coupled with the synthetic aperture focusing technique (SAFT). The primary focus of this work is to provide information to the United States Nuclear Regulatory Commission on the utility, effectiveness and reliability of ultrasonic testing (UT) inspection techniques as related to the inservice ultrasonic inspection of coarse grained primary piping components in pressurized water reactors (PWRs).

Diaz, Aaron A.; Harris, R. V.; Doctor, Steven R.

2008-11-01T23:59:59.000Z

294

Electro-optical and Magneto-optical Sensing Apparatus and Method for Characterizing Free-space Electromagnetic Radiation  

DOE Patents [OSTI]

Apparatus and methods for characterizing free-space electromagnetic energy, and in particular, apparatus/method suitable for real-time two-dimensional far-infrared imaging applications are presented. The sensing technique is based on a non-linear coupling between a low-frequency electric (or magnetic) field and a laser beam in an electro-optic (or magnetic-optic) crystal. In addition to a practical counter-propagating sensing technique, a co-linear approach is described which provides longer radiated field-optical beam interaction length, thereby making imaging applications practical.

Zhang, Xi-Cheng; Riordan, Jenifer Ann; Sun, Feng-Guo

2000-08-29T23:59:59.000Z

295

Electromagnetic Effects in SDF Explosions  

SciTech Connect (OSTI)

The notion of high ion and electron concentrations in the detonation of aluminized explosive mixtures has aroused some interest in electro-magnetic effects that the SDF charges might generate when detonated. Motivated by this interest we have started to investigate whether significant electro-magnetic effects show up in our small-scale experiments. However, the design of instrumentation for this purpose is far from straightforward, since there are a number of open questions. Thus the main aim of the feasibility tests is to find - if possible - a simple and reliable method that can be used as a diagnostic tool for electro-magnetic effects. SDF charges with a 0.5-g PETN booster and a filling of 1 g aluminum flakes have been investigated in three barometric bomb calorimeters with volumes ranging from 6.3 l to of 6.6 l. Though similar in volume, the barometric bombs differed in the length-to-diameter ratio. The tests were carried out with the bombs filled with either air or nitrogen at ambient pressure. The comparison of the test in air to those in nitrogen shows that the combustion of TNT detonation products or aluminum generates a substantial increase of the quasi-steady overpressure in the bombs. Repeated tests in the same configuration resulted in some scatter of the experimental results. The most likely reason is that the aluminum combustion in most or all cases is incomplete and that the amount of aluminum actually burned varies from test to test. The mass fraction burned apparently decreases with increasing aspect ratio L/D. Thus an L/D-ratio of about 1 is optimal for the performance of shock-dispersed-fuel combustion. However, at an L/D-ratio of about 5 the combustion still yields appreciable overpressure in excess of the detonation. For a multi-burst scenario in a tunnel environment with a number of SDF charges distributed along a tunnel section a spacing of 5 tunnel diameter and a fuel-specific volume of around 7 l/g might provide an acceptable compromise between optimizing the combustion performance and keeping the number of elementary charges low. Further tests in a barometric bomb calorimeter of 21.2 l volume were performed with four types of aluminum. The mass fraction burned in this case appeared to depend on the morphology of the aluminum particles. Flake aluminum exhibited a better performance than granulated aluminum with particle sizes ranging from below 25 {micro}m to 125 {micro}m for the coarsest material. In addition, a feasibility study on electro-magnetic effects from SDF charges detonated in a tunnel has been performed. A method was developed to measure the local, unsteady electro-conductivity in the detonation/combustion products cloud. This method proved to yield reproducible results. A variety of methods were tested with regard to probing electro-magnetic pulses from the detonation of SDF charges. The results showed little reproducibility and were small compared to the effect from pulsed high voltage discharges of comparatively small energy (around 32 J). Thus either no significant electromagnetic pulse is generated in our small-scale tests or the tested techniques have to be discarded as too insensitive or too limited in bandwidth to detect possibly very high frequency electro-magnetic disturbances.

Reichenbach, H; Neuwald, P; Kuhl, A L

2010-02-12T23:59:59.000Z

296

Purely electromagnetic spacetimes  

E-Print Network [OSTI]

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.

B. V. Ivanov

2007-12-15T23:59:59.000Z

297

Asia Pacific Symposium of Applied Electromagnetics and Mechanics (APSAEM2010) Kuala Lumpur, Malaysia, 28-30th  

E-Print Network [OSTI]

, Malaysia, 28-30th July 2010 Reducing Electromagnetic Interference in Non-Isolated DC to DC Step JAMALUDIN*2 Investigation of the Electromagnetic interference (EMI) is important for design of a good power: electromagnetic interference, power converter, EMI, ohmic heating, high frequency. 1. Introduction In order

Hammerton, James

298

Electromagnetic rotational actuation.  

SciTech Connect (OSTI)

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.

Hogan, Alexander Lee

2010-08-01T23:59:59.000Z

299

Introduction Framework Multiscale Expansion Axisymmetric Problems FEM Simulations Postprocessing A Transmission Problem in Electromagnetism with a  

E-Print Network [OSTI]

A Transmission Problem in Electromagnetism with a Singular Interface GABRIEL CALOZ 2 MONIQUE DAUGE 2 ERWAN FAOU 2´eron A Transmission Problem in Electromagnetism with a Singular Interface 1 / 33 inria-00528523,version1-22Oct2010 of electromagnetic fields with depth inside the conductor. The Skin Depth : () = 2/µ0 V. P´eron A Transmission

Paris-Sud XI, Université de

300

THIN LAYER MODELS FOR ELECTROMAGNETISM MARC DURUFLE, VICTOR PERON, AND CLAIR POIGNARD  

E-Print Network [OSTI]

THIN LAYER MODELS FOR ELECTROMAGNETISM MARC DURUFL´E, VICTOR P´ERON, AND CLAIR POIGNARD ABSTRACT of electromagnetic waves in domains with thin layer. These models appear as first order approximations of the electromagnetic field. They are obtained thanks to a multiscale expansion of the exact solution with respect

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Gradient instabilities of electromagnetic waves in Hall thruster plasma  

SciTech Connect (OSTI)

This paper presents a linear analysis of gradient plasma instabilities in Hall thrusters. The study obtains and analyzes the dispersion equation of high-frequency electromagnetic waves based on the two-fluid model of a cold plasma. The regions of parameters corresponding to unstable high frequency modes are determined and the dependence of the increments and intrinsic frequencies on plasma parameters is obtained. The obtained results agree with those of previously published studies.

Tomilin, Dmitry [Department of Electrophysics, Keldysh Research Centre, Moscow 125438 (Russian Federation)

2013-04-15T23:59:59.000Z

302

Scanning evanescent electro-magnetic microscope  

DOE Patents [OSTI]

A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

Xiang, Xiao-Dong (Alameda, CA); Gao, Chen (Alameda, CA)

2001-01-01T23:59:59.000Z

303

Duality in Off-Shell Electromagnetism  

E-Print Network [OSTI]

In this paper, we examine the Dirac monopole in the framework of Off-Shell Electromagnetism, the five dimensional U(1) gauge theory associated with Stueckelberg-Schrodinger relativistic quantum theory. After reviewing the Dirac model in four dimensions, we show that the structure of the five dimensional theory prevents a natural generalization of the Dirac monopole, since the theory is not symmetric under duality transformations. It is shown that the duality symmetry can be restored by generalizing the electromagnetic field strength to an element of a Clifford algebra. Nevertheless, the generalized framework does not permit us to recover the phenomenological (or conventional) absence of magnetic monopoles.

Martin Land

2006-03-21T23:59:59.000Z

304

Radial electric field generated by resonant trapped electron pinch with radio frequency injection in a tokamak plasma  

E-Print Network [OSTI]

electrons in the direction parallel to the toroidal field. It was found that, for typical tokamak parameters required in ITER or future reactors. Therefore, it is of great interest to investigate methods of flow and transport was provided in sequential time scales. In addition, an inter-machine comparison of intrinsic

305

Vacuum energy densities of a field in a cavity with a mobile boundary  

E-Print Network [OSTI]

We consider the zero-point field fluctuations, and the related field energy densities, inside a one-dimensional and a three-dimensional cavity with a mobile wall. The mechanical degrees of freedom of the mobile wall are described quantum mechanically and they are fully included in the overall system dynamics. In this optomechanical system, the field and the wall can interact with each other through the radiation pressure on the wall, given by the photons inside the cavity or even by vacuum fluctuations. We consider two cases: the one-dimensional electromagnetic field and the three-dimensional scalar field, and use the Green's functions formalism, which allows extension of the results obtained for the scalar field to the electromagnetic field. We show that the quantum fluctuations of the position of the cavity's mobile wall significantly affect the field energy density inside the cavity, in particular at the very proximity of the mobile wall. The dependence of this effect from the ultraviolet cutoff frequency, related to the plasma frequency of the cavity walls, is discussed. We also compare our new results for the one-dimensional electromagnetic field and the three-dimensional massless scalar field to results recently obtained for the one-dimensional massless scalar field. We show that the presence of a mobile wall also changes the Casimir-Polder force on a polarizable body placed inside the cavity, giving the possibility to detect experimentally the new effects we have considered.

Federico Armata; Roberto Passante

2015-01-15T23:59:59.000Z

306

Effects of Electromagnetic Fields on Fish and Invertebrates: Task 2.1.3: Effects on Aquatic Organisms - Fiscal Year 2011 Progress Report - Environmental Effects of Marine and Hydrokinetic Energy  

SciTech Connect (OSTI)

This fiscal year (FY) 2011 progress report (Task 2.1.3 Effects on Aquatic Organisms, Subtask 2.3.1.1 Electromagnetic Fields) describes studies conducted by PNNL as part of the DOE Wind and Water Power Program to examine the potential effects of electromagnetic fields (EMF) from marine and hydrokinetic devices on aquatic organisms, including freshwater and marine fish and marine invertebrates. In this report, we provide a description of the methods and results of experiments conducted in FY 2010-FY 2011 to evaluate potential responses of selected aquatic organisms. Preliminary EMF laboratory experiments during FY 2010 and 2011 entailed exposures with representative fish and invertebrate species including juvenile coho salmon (Oncorhynchus kisutch), Atlantic halibut (Hippoglossus hippoglossus), California halibut (Paralicthys californicus), rainbow trout (Oncorhynchus mykiss), and Dungeness crab (Metacarcinus magister). These species were selected for their ecological, commercial, and/or recreational importance, as well as their potential to encounter an MHK device or transmission cable during part or all of their life cycle. Based on previous studies, acute effects such as mortality were not expected to occur from EMF exposures. Therefore, our measurement endpoints focused on behavioral responses (e.g., detection of EMF, interference with feeding behavior, avoidance or attraction to EMF), developmental changes (i.e., growth and survival from egg or larval stage to juvenile), and exposure markers indicative of physiological responses to stress. EMF intensities during the various tests ranged from 0.1 to 3 millitesla, representing a range of upper bounding conditions reported in the literature. Experiments to date have shown there is little evidence to indicate distinct or extreme behavioral responses in the presence of elevated EMF for the species tested. Several developmental and physiological responses were observed in the fish exposures, although most were not statistically significant. Additional species are currently planned for laboratory testing in the next fiscal year (e.g. an elasmobranch, American lobster) to provide a broader assessment of species important to stakeholders. The collective responses of all species will be assessed in terms of life stage, exposure scenarios, and biological relevance, to address current uncertainties related to effects of EMF on aquatic organisms.

Woodruff, Dana L.; Schultz, Irvin R.; Marshall, Kathryn E.; Ward, Jeffrey A.; Cullinan, Valerie I.

2012-05-01T23:59:59.000Z

307

Reconstruction of the three mechanical material constants of a lossy fluid-like cylinder from low-frequency scattered acoustic fields  

E-Print Network [OSTI]

The inverse medium problem for a circular cylindrical domain is studied using low-frequency acoustic waves as the probe radiation. It is shown that to second order in $k_{0}a$ ($k_{0}$ the wavenumber in the host medium, $a$ the radius of the cylinder), only the first three terms (i.e., of orders 0, -1 and +1) in the partial wave representation of the scattered field are non-vanishing, and the material parameters enter into these terms in explicit manner. Moreover, the zeroth-order term contains only two of the unknown material constants (i.e., the real and imaginary parts of complex compressibility of the cylinder $\\kappa_{1}$) whereas the $\\pm 1$ order terms contain the other material constant (i.e., the density of the cylinder $\\rho_{1}$). A method, relying on the knowledge of the totality of the far-zone scattered field and resulting in explicit expressions for $\\rho_{1}$ and $\\kappa_{1}$, is devised and shown to give highly-accurate estimates of these quantities even for frequencies such that $k_{0}a$ is ...

Scotti, T; Scotti, Thierry; Wirgin, Armand

2003-01-01T23:59:59.000Z

308

Electromagnetic Radiations as a Fluid Flow  

E-Print Network [OSTI]

We combine Maxwell's equations with Eulers's equation, related to a velocity field of an immaterial fluid, where the density of mass is replaced by a charge density. We come out with a differential system able to describe a relevant quantity of electromagnetic phenomena, ranging from classical dipole waves to solitary wave-packets with compact support. The clue is the construction of an energy tensor summing up both the electromagnetic stress and a suitable mass tensor. With this right-hand side, explicit solutions of the full Einstein's equation are computed for a wide class of wave phenomena. Since our electromagnetic waves may behave and interact exactly as a material fluid, they can create vortex structures. We then explicitly analyze some vortex ring configurations and examine the possibility to build a model for the electron.

Daniele Funaro

2009-11-25T23:59:59.000Z

309

EMG #121471 Electromagnetics, 25:679693, 2005  

E-Print Network [OSTI]

. Keywords electromagnetic compatibility, electromagnetic interference, aperture, cou- pling, finite compatibility (EMC) and electromagnetic interference (EMI) requirements, it is crucial to quantify

Ramahi, Omar

310

Electromagnetic SCRF Cavity Tuner  

SciTech Connect (OSTI)

A novel prototype of SCRF cavity tuner is being designed and tested at Fermilab. This is a superconducting C-type iron dominated magnet having a 10 mm gap, axial symmetry, and a 1 Tesla field. Inside the gap is mounted a superconducting coil capable of moving {+-} 1 mm and producing a longitudinal force up to {+-} 1.5 kN. The static force applied to the RF cavity flanges provides a long-term cavity geometry tuning to a nominal frequency. The same coil powered by fast AC current pulse delivers mechanical perturbation for fast cavity tuning. This fast mechanical perturbation could be used to compensate a dynamic RF cavity detuning caused by cavity Lorentz forces and microphonics. A special configuration of magnet system was designed and tested.

Kashikhin, V.; Borissov, E.; Foster, G.W.; Makulski, A.; Pischalnikov, Y.; Khabiboulline, T.; /Fermilab

2009-05-01T23:59:59.000Z

311

Excitation of electrostatic waves in the electron cyclotron frequency range during magnetic reconnection in laboratory overdense plasmas  

SciTech Connect (OSTI)

We report the observation of electromagnetic radiation at high harmonics of the electron cyclotron frequency that was considered to be converted from electrostatic waves called electron Bernstein waves (EBWs) during magnetic reconnection in laboratory overdense plasmas. The excitation of EBWs was attributed to the thermalization of electrons accelerated by the reconnection electric field around the X-point. The radiative process discussed here is an acceptable explanation for observed radio waves pulsation associated with major flares.

Kuwahata, A., E-mail: kuwahata@ts.t.u-tokyo.ac.jp [Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656 (Japan); Igami, H. [National Institute for Fusion Science, Toki 509-5292 (Japan); Kawamori, E. [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China); Kogi, Y. [Fukuoka Institute of Technology, Fukuoka 811-0295 (Japan); Inomoto, M.; Ono, Y. [Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561 (Japan)

2014-10-15T23:59:59.000Z

312

3. ELECTROMAGNETIC COMPATIBILITY Abstract --The electromagnetic interference between the  

E-Print Network [OSTI]

walls and tubes) and with strong EMI (Electromagnetic Interference). So it is ideal to use the power

Paris-Sud XI, Université de

313

Electromagnetic Scattering by Spheres of Topological Insulators  

E-Print Network [OSTI]

The electromagnetic scattering properties of topological insulator (TI) spheres are systematically studied in this paper. Unconventional backward scattering caused by the topological magneto-electric (TME) effect of TIs are found in both Rayleigh and Mie scattering regimes. This enhanced backward scattering can be achieved by introducing an impedance-matched background which can suppress the bulk scattering. For the cross-polarized scattering coefficients, interesting antiresonances are found in the Mie scattering regime, wherein the cross-polarized electromagnetic fields induced by the TME effect are trapped inside TI spheres. In the Rayleigh limit, the quantized TME effect of TIs can be determined by measuring the electric-field components of scattered waves in the far field.

Ge, Lixin; Zi, Jian

2015-01-01T23:59:59.000Z

314

Quasinormal modes of test fields around regular black holes  

E-Print Network [OSTI]

We study scalar, electromagnetic and gravitational test fields in the Hayward, Bardeen and Ay\\'{o}n-Beato-Garc\\'{i}a regular black hole spacetimes and demonstrate that the test fields are stable in all these spacetimes. Using the sixth order WKB approximation of the linear "axial" perturbative scheme, we determine dependence of the quasinormal mode (QNM) frequencies on the characteristic parameters of the test fields and the spacetime charge parameters of the regular black holes. We give also the greybody factors, namely the transmission and reflection coefficients of scattered scalar, electromagnetic and gravitational waves. We show that damping of the QNMs in regular black hole spacetimes is suppressed in comparison to the case of Schwarzschild black holes, and increasing charge parameter of the regular black holes increases reflection and decreases transmission factor of incident waves for each of the test fields.

Bobir Toshmatov; Ahmadjon Abdujabbarov; Zden?k Stuchlík; Bobomurat Ahmedov

2015-03-19T23:59:59.000Z

315

Electromagnetic Mass Models in General Theory of Relativity  

E-Print Network [OSTI]

"Electromagnetic mass" where gravitational mass and other physical quantities originate from the electromagnetic field alone has a century long distinguished history. In the introductory chapter we have divided this history into three broad categories -- classical, quantum mechanical and general relativistic. Each of the categories has been described at a length to get the detailed picture of the physical background. Recent developments on Repulsive Electromagnetic Mass Models are of special interest in this introductory part of the thesis. In this context we have also stated motivation of our work. In the subsequent chapters we have presented our results and their physical significances. It is concluded that the electromagnetic mass models which are the sources of purely electromagnetic origin ``have not only heuristic flavor associated with the conjecture of Lorentz but even a physics having unconventional yet novel features characterizing their own contributions independent of the rest of the physics".

Sumana Bhadra

2007-10-30T23:59:59.000Z

316

Televisions, Video Privacy, and Powerline Electromagnetic Interference  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iv Safe Use Guidelines, Electromagnetic Interference, and FCC Warning . . . . . . . . . . . . .v

Matsuoka, Yoky

317

Electromagnetic Radiation REFERENCE: Remote Sensing of  

E-Print Network [OSTI]

1 CHAPTER 2: Electromagnetic Radiation Principles REFERENCE: Remote Sensing of the Environment John;2 Electromagnetic Energy Interactions Energy recorded by remote sensing systems undergoes fundamental interactions, creating convectional currents in the atmosphere. c) Electromagnetic energy in the form of electromagnetic

Gilbes, Fernando

318

Electromagnetically Induced Flows Michiel de Reus  

E-Print Network [OSTI]

Electromagnetically Induced Flows in Water Michiel de Reus 8 maart 2013 () Electromagnetically Conclusion and future research () Electromagnetically Induced Flows 2 / 56 #12;1 Introduction 2 Maxwell Navier Stokes equations 5 Simulations 6 Conclusion and future research () Electromagnetically Induced

Vuik, Kees

319

Quantum mechanics of a charged particle in a background magnetic field interacting with linearized gravitational waves  

E-Print Network [OSTI]

We consider the dynamics of a charged particle interacting with background electromagnetic field under the influence of linearized gravitational waves in the long wave-length and low-velocity limit. Following the prescription in \\cite{speli}, the system is quantized and the Hamiltonian is then solved by using standard algebraic iterative methods. The solution is in conformity with the classical analysis and shows the possibility of tuning the frequency by changing the magnetic field to set up resonance.

Sunandan Gangopadhyay; Anirban Saha

2012-04-02T23:59:59.000Z

320

618 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 49, NO. 3, JUNE 2002 A Comparative Study of Carrier-Frequency  

E-Print Network [OSTI]

-frequency modulation (CFM) techniques for the conducted electromagnetic interference (EMI) suppression in pulsewidth. The most direct way of solving electromagnetic interference (EMI) problems is to reduce the emission from

So, Hing-Cheung

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

A new low-frequency backward mode in inhomogeneous plasmas  

SciTech Connect (OSTI)

When an electromagnetic transverse wave propagates through an inhomogeneous plasma so that its electric field has a component in the direction of the background density gradient, there appears a disbalance of charge in every plasma layer, caused by the density gradient. Due to this, some additional longitudinal electric field component appears in the direction of the wave vector. This longitudinal field may couple with the usual electrostatic longitudinal perturbations like the ion acoustic, electron Langmuir, and ion plasma waves. As a result, these standard electrostatic waves are modified and in addition to this a completely new low-frequency mode appears. Some basic features of the coupling and modification of the ion acoustic wave, and properties of the new mode are discussed here, in ordinary electron-ion and in pair plasmas.

Vranjes, J., E-mail: jvranjes@yahoo.com [Institute of Physics, Pregrevica 118, 11080 Zemun, Belgrade (Serbia)

2014-07-15T23:59:59.000Z

322

A generalized Debye source approach to electromagnetic scattering in layered media  

SciTech Connect (OSTI)

The standard solution to time-harmonic electromagnetic scattering problems in homogeneous layered media relies on the use of the electric field dyadic Green's function. However, for small values of the governing angular frequency ?, evaluation of the electric field using this Green's function exhibits numerical instability. In this short note, we provide an alternative approach which is immune from this low-frequency breakdown as ? ? 0. Our approach is based on the generalized Debye source representation of Maxwell fields. Using this formulation, the electric and magnetic fields gracefully decouple in the static limit, a behavior similar to that of the classical Lorenz-Debye-Mie representation of Maxwell fields in spherical geometries. We derive extensions of both the generalized Deybe source and Lorenz-Debye-Mie representations to planar geometries, as well as provide equations for the solution of scattering from a perfectly conducting half-space and in layered media using a Sommerfeld-like approach. These formulas are stable as ? tends to zero, and offer alternatives to the electric field dyadic Green's function.

O’Neil, Michael, E-mail: oneil@cims.nyu.edu [Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, New York 10012 (United States)] [Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, New York 10012 (United States)

2014-01-15T23:59:59.000Z

323

Electromagnetic Wave Dynamics in  

E-Print Network [OSTI]

possibilities for strong localization of electromagnetic radiation in a dense and ultracold atomic gas sample an ultracold atomic rubidium gas sample, showing the coherent backscattering cone. The angular width of electrical excita- tion of condensed samples.3 Ongoing experimental and theoretical research directed toward

324

Electromagnetism and Gravitation  

E-Print Network [OSTI]

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.

Kenneth Dalton

1997-03-10T23:59:59.000Z

325

Electromagnetic pulsar spindown  

E-Print Network [OSTI]

We evaluate the result of the recent pioneering numerical simulations in Spitkovsky~2006 on the spindown of an oblique relativistic magnetic dipole rotator. Our discussion is based on our experience from two idealized cases, that of an aligned dipole rotator, and that of an oblique split-monopole rotator. We conclude that the issue of electromagnetic pulsar spindown may not have been resolved yet.

I. Contopoulos

2007-01-10T23:59:59.000Z

326

Electromagnetic wave propagation through an overdense magnetized collisional plasma layer  

SciTech Connect (OSTI)

The results of investigations into the feasibility of using a magnetic window to propagate electromagnetic waves through a finite-sized overdense plasma slab are described. We theoretically calculate the transmission coefficients for right- and left-handed circularly polarized plane waves through a uniform magnetized plasma slab. Using reasonable estimates for the plasma properties expected to be found in the ionized shock layer surrounding a hypersonic aircraft traveling in the earth's upper atmosphere (radio blackout conditions), and assuming a 1 GHz carrier frequency for the radio communications channel, we find that the required magnetic field for propagation of right-handed circularly polarized, or whistler, waves is on the order of a few hundred gauss. Transmission coefficients are calculated as a function of sheath thickness and are shown to be quite sensitive to the electron collision frequency. One-dimensional particle-in-cell simulations are shown to be in good agreement with the theory. These simulations also demonstrate that Ohmic heating of the electrons can be considerable. Two- and three-dimensional particle-in-cell simulations using a simplified waveguide and antenna model illustrate the same general transmission behavior as the theory and one-dimensional simulations. In addition, a net focusing effect due to the plasma is also observed in two and three dimensions. These simulations can be extended to design and analyze more realistic waveguide and antenna models.

Thoma, C.; Rose, D. V.; Miller, C. L.; Clark, R. E.; Hughes, T. P. [Voss Scientific LLC, Albuquerque, New Mexico 87108 (United States)

2009-08-15T23:59:59.000Z

327

Electromagnetic fluctuation-induced interactions in randomly charged slabs  

E-Print Network [OSTI]

Randomly charged net-neutral dielectric slabs are shown to interact across a featureless dielectric continuum with long-range electrostatic forces that scale with the statistical variance of their quenched random charge distribution and inversely with the distance between their bounding surfaces. By accounting for the whole spectrum of electromagnetic field fluctuations, we show that this long-range disorder-generated interaction extends well into the retarded regime where higher-order Matsubara frequencies contribute significantly. This occurs even for highly clean samples with only a trace amount of charge disorder and shows that disorder effects can be important down to the nano scale. As a result, the previously predicted non-monotonic behavior for the total force between dissimilar slabs as a function of their separation distance is substantially modified by higher-order contributions, and in almost all cases of interest, we find that the equilibrium inter-surface separation is shifted to substantially larger values compared to predictions based solely on the zero-frequency component. This suggests that the ensuing non-monotonic interaction is more easily amenable to experimental detection. The presence of charge disorder in the intervening dielectric medium between the two slabs is shown to lead to an additional force that can be repulsive or attractive depending on the system parameters and can, for instance, wash out the non-monotonic behavior of the total force when the intervening slab contains a sufficiently large amount of disorder charges.

Vahid Rezvani; Jalal Sarabadani; Ali Naji; Rudolf Podgornik

2012-07-19T23:59:59.000Z

328

A method for calculating wide band electromagnetic interference from power line corona  

SciTech Connect (OSTI)

An algorithm for calculating electromagnetic interference from power line corona for a range of frequencies from 100 kHz to 30 MHz is demonstrated. It can be used for calculations at any distance or direction from the line. The algorithm incorporates an existing generation function which has been optimized by comparison to long term electromagnetic interference measurements.

Olsen, R.G. [Washington State Univ., Pullman, WA (United States). School of Electrical Engineering and Computer Science] [Washington State Univ., Pullman, WA (United States). School of Electrical Engineering and Computer Science; Schennum, S.D. [Gonzaga Univ., Spokane, WA (United States)] [Gonzaga Univ., Spokane, WA (United States)

1995-07-01T23:59:59.000Z

329

The CLAS Forward Electromagnetic Calorimeter  

SciTech Connect (OSTI)

The CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab utilizes six iron-free superconducting coils to provide an approximately toroidal magnetic field. The six sectors are instrumented individually to form six independent spectrometers. The forward region (8deg < (theta) < 45deg) of each sector is equipped with a lead-scintillator electromagnetic sampling calorimeter (EC), 16 radiation lengths thick, using a novel triangular geometry with stereo readout. With its good energy and position resolution, the EC is used to provide the primary electron trigger for CLAS. It is also used to reject pions, reconstruct pi-0 and eta decays and detect neutrons, This paper treats the design, construction and performance of the calorimeter.

M. Amarian; Geram Asryan; Kevin Beard; Will Brooks; Volker Burkert; Tom Carstens; Alan Coleman; Raphael Demirchyan; Yuri Efremenko; Hovanes Egiyan; Kim Egiyan; Herb Funsten; Vladimir Gavrilov; Kevin L. Giovanetti; R.M. Marshall; Berhard Mecking; R.C. Minehart; H. Mkrtchan; Mavrik Ohandjanyan; Youri Sharabian; L.C. Smith; Stepan Stepanyan; W.A. Stephens; T.Y. Tung; Carl Zorn

2001-05-01T23:59:59.000Z

330

Electromagnetic Properties of the Early Universe  

E-Print Network [OSTI]

Detailed physical processes of magnetic field generation from density fluctuations in the pre-recombination era are studied. Solving Maxwell equations and the generalized Ohm's law, the evolutions of the net charge density, the electric current and the electromagnetic field are solved. Unlike most of previous works, we treat electrons and photons as separate components under the assumption of tight coupling. We find that generation of the magnetic field due to density fluctuations takes place only from the second order of both perturbation theory and the tight coupling approximation.

Keitaro Takahashi; Kiyotomo Ichiki; Naoshi Sugiyama

2008-05-29T23:59:59.000Z

331

Graphene Frequency Multipliers  

E-Print Network [OSTI]

In this letter, the ambipolar transport properties of graphene flakes have been used to fabricate full-wave signal rectifiers and frequency-doubling devices. By correctly biasing an ambipolar graphene field-effect transistor ...

Wang, Han

332

Vibration Isolation using a Shunted Electromagnetic S. Behrens, A. J. Fleming, S. O. R. Moheimani  

E-Print Network [OSTI]

a base disturbance y. A low- frequency mass-spring-damper is often employed as a mechanical filter to the terminals of an electromagnetic coil, the relative mechanical velocity between the coil and magnet can

Fleming, Andrew J.

333

An approach to electromagnetism from the general relativity  

E-Print Network [OSTI]

Classical gravitation is so similar to the electrostatic that the possible unification has been investigated for many years. Although electromagnetism is formulated successfully by quantum field theory, this paper proposes a simple approach to describe the electromagnetism from the macroscopic perspective of general relativity. The hypothesis is based on two charged particles that cause disturbance energy sufficient to disrupt the space-time and explain approximately Maxwell's equations. Therefore, with such this simple idea, we suggest the possibility that the geometric relationship between electromagnetism and gravitation is not yet fully exhausted.

Robert Monjo i Agut

2013-12-02T23:59:59.000Z

334

Theory of electromagnetic fluctuations for magnetized multi-species plasmas  

SciTech Connect (OSTI)

Analysis of electromagnetic fluctuations in plasma provides relevant information about the plasma state and its macroscopic properties. In particular, the solar wind persistently sustains a small but detectable level of magnetic fluctuation power even near thermal equilibrium. These fluctuations may be related to spontaneous electromagnetic fluctuations arising from the discreteness of charged particles. Here, we derive general expressions for the plasma fluctuations in a multi-species plasma following arbitrary distribution functions. This formalism, which generalizes and includes previous works on the subject, is then applied to the generation of electromagnetic fluctuations propagating along a background magnetic field in a plasma of two proton populations described by drifting bi-Maxwellians.

Navarro, Roberto E., E-mail: roberto.navarro@ug.uchile.cl; Muñoz, Víctor [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Araneda, Jaime [Departamento de Física, Universidad de Concepción, Concepción 4070386 (Chile); Moya, Pablo S. [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, Maryland 20771 (United States); Department of Physics, Catholic University of America, Washington, D. C. 20064 (United States); Viñas, Adolfo F. [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, Maryland 20771 (United States); Valdivia, Juan A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Centro de Estudios Interdisciplinarios Básicos y Aplicados en Complejidad, CEIBA complejidad, Bogotá (Colombia)

2014-09-15T23:59:59.000Z

335

Quantum field theoretical description for the reflectivity of graphene  

E-Print Network [OSTI]

We derive the polarization tensor of graphene at nonzero temperature in (2+1)-dimensional space-time. The obtained tensor coincides with the previously known one at all Matsubara frequencies, but, in contrast to it, admits analytic continuation to the real frequency axis satisfying all physical requirements. Using the obtained representation for the polarization tensor, we develope quantum field theoretical description for the reflectivity of graphene. The analytic asymptotic expressions for the reflection coefficients and reflectivities at low and high frequencies are derived for both independent polarizations of the electromagnetic field. The dependencies of reflectivities on the frequency and angle of incidence are investigated. Numerical computations using the exact expressions for the polarization tensor are performed and application regions for the analytic asymptotic results are determined.

Bordag, M; Mostepanenko, V M; Petrov, V M

2015-01-01T23:59:59.000Z

336

Electromagnetic time reversal algorithms and source localization in lossy dielectric media  

E-Print Network [OSTI]

The problem of reconstructing the spatial support of an extended radiating electric current source density in a lossy dielectric medium from transient boundary measurements of the electric fields is studied. A time reversal algorithm is proposed to localize a source density from loss-less wave-field measurements. Further, in order to recover source densities in a lossy medium, we first build attenuation operators thereby relating loss-less waves with lossy ones. Then based on asymptotic expansions of attenuation operators with respect to attenuation parameter, we propose two time reversal strategies for localization. The losses in electromagnetic wave propagation are incorporated using the Debye's complex permittivity, which is well-adopted for low frequencies (radio and microwave) associated with polarization in dielectrics.

Abdul Wahab; Amer Rasheed; Tasawar Hayat; Rab Nawaz

2014-09-16T23:59:59.000Z

337

Progress In Electromagnetics Research, PIER 74, 119, 2007 ANALYSIS OF INTERACTION BETWEEN A  

E-Print Network [OSTI]

partially re-radiates, and partially dissipates within the FR body, eventually producing heat. Both re-radiated energy and heat loss in the FR depend on coupling between the FR and the electromagnetic field picks out energy from electromagnetic field at the ferromagnetic resonance. Thus the typical linewidth

Koledintseva, Marina Y.

338

Electromagnetic Siegert states for periodic dielectric structures  

E-Print Network [OSTI]

The formalism of Siegert states to describe the resonant scattering in quantum theory is extended to the resonant scattering of electromagnetic waves on periodic dielectric arrays. The excitation of electromagnetic Siegert states by an incident wave packet and their decay is studied. The formalism is applied to develop a theory of coupled electromagnetic resonances arising in the electromagnetic scattering problem for two such arrays separated by a distance 2h (or, generally, when the physical properties of the scattering array depend on a real coupling parameter h). Analytic properties of Siegert states as functions of the coupling parameter h are established by the Regular Perturbation Theorem which is an extension the Kato-Rellich theorem to the present case. By means of this theorem, it is proved that if the scattering structure admits a bound state in the radiation continuum at a certain value of the coupling parameter h, then there always exist regions within the structure in which the near field can be amplified as much as desired by adjusting the value of h. This establishes a rather general mechanism to control and amplify optical nonlinear effects in periodically structured planar structures possessing a nonlinear dielectric susceptibility.

Friends R. Ndangali; Sergei V. Shabanov

2011-08-09T23:59:59.000Z

339

Gravitation and Electromagnetism  

E-Print Network [OSTI]

The realms of gravitation, belonging to Classical Physics, and Electromagnetism, belonging to the Theory of the Electron and Quantum Mechanics have remained apart as two separate pillars, inspite of a century of effort by Physicists to reconcile them. In this paper it is argued that if we extend ideas of Classical spacetime to include in addition to non integrability non commutavity also, then such a reconcilation is possible.

B. G. Sidharth

2001-06-16T23:59:59.000Z

340

Fractional Electromagnetic Waves  

E-Print Network [OSTI]

In the present work we consider the electromagnetic wave equation in terms of the fractional derivative of the Caputo type. The order of the derivative being considered is 0 <\\gamma<1. A new parameter \\sigma, is introduced which characterizes the existence of the fractional components in the system. We analyze the fractional derivative with respect to time and space, for \\gamma = 1 and \\gamma = 1/2 cases.

J. F. Gómez; J. J. Rosales; J. J. Bernal; V. I. Tkach; M. Guía

2011-08-31T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Banded electromagnetic stator core  

DOE Patents [OSTI]

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figs.

Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

1996-06-11T23:59:59.000Z

342

Banded electromagnetic stator core  

DOE Patents [OSTI]

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.

Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

1994-04-05T23:59:59.000Z

343

Analysis of electromagnetic scattering by nearly periodic structures: an LDRD report.  

SciTech Connect (OSTI)

In this LDRD we examine techniques to analyze the electromagnetic scattering from structures that are nearly periodic. Nearly periodic could mean that one of the structure's unit cells is different from all the others--a defect. It could also mean that the structure is truncated, or butted up against another periodic structure to form a seam. Straightforward electromagnetic analysis of these nearly periodic structures requires us to grid the entire structure, which would overwhelm today's computers and the computers in the foreseeable future. In this report we will examine various approximations that allow us to continue to exploit some aspects of the structure's periodicity and thereby reduce the number of unknowns required for analysis. We will use the Green's Function Interpolation with a Fast Fourier Transform (GIFFT) to examine isolated defects both in the form of a source dipole over a meta-material slab and as a rotated dipole in a finite array of dipoles. We will look at the numerically exact solution of a one-dimensional seam. In order to solve a two-dimensional seam, we formulate an efficient way to calculate the Green's function of a 1d array of point sources. We next formulate ways of calculating the far-field due to a seam and due to array truncation based on both array theory and high-frequency asymptotic methods. We compare the high-frequency and GIFFT results. Finally, we use GIFFT to solve a simple, two-dimensional seam problem.

Johnson, William Arthur; Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Wilton, Donald R. (University of Houston, Houston, TX); Basilio, Lorena I.; Peters, David William; Capolino, F. (University of Houston, Houston, TX)

2006-10-01T23:59:59.000Z

344

Electromagnetic Perturbations in the Reconnecting Current Sheet in MRX  

SciTech Connect (OSTI)

Magnetic reconnection is a fundamental plasma process in which magnetic field lines break and reconnect, converting magnetic field energy into particle kinetic energy. Electromagnetic fluctuations, which may play a role in fast reconnection, are studied from both an experimental and theoretical standpoint. The waves, which are in the lower hybrid range of frequencies, may be produced by a plasma instability known as the oblique lower hybrid drift instability. When the electron drift velocity is large, the theory predicts coupling between whistler and acoustic waves in the ion frame that may lead to an instability in the vicinity of the current sheet. On the experimental side, an antenna placed in the Magnetic Reconnection Experiment (MRX) at the Princeton Plasma Physics Laboratory is used to apply perturbations, and their propagation characteristics are measured. Results from a 2mm diameter antenna indicate that any induced fluctuations are confined to the current sheet and are preferentially excited in the direction of electron flow within the layer. Preliminary data from a 2cm diameter antenna shows a wave propagating in the electron flow direction at the local electron drift velocity. Thus electron drift appears to play a crucial role in the appearance of fluctuations.

Dorfman, Seth; Ji, Hantao; Yamada, MasAki; Ren Yang; Gerhardt, Stefan; Kulsrud, Russell; McGeehan, Brendan; Wang Yansong [Princeton Plasma Physics Laboratory, Princeton NJ 08540 (United States)

2006-11-30T23:59:59.000Z

345

Generalized Terminal Modeling of Electromagnetic Interference  

SciTech Connect (OSTI)

Terminal models have been used for various applications. In this paper, a three-terminal model is proposed for electromagnetic-interference (EMI) characterization. The model starts with a power electronic system at a particular operating condition and creates a unique linearized equivalent circuit. Impedances and current/voltage sources define the noise throughout the entire EMI frequency spectrum. All parameters needed to create the model are clearly defined to ensure convergence and maximize accuracy. In addition, the accuracy of the model is confirmed up to 100 MHz for a dc-dc boost converter using both simulation and experimental validation.

Baisden, Andrew Carson [IEEE Industrial Applications Society; Boroyevich, Dushan [Virginia Polytechnic Institute and State University (Virginia Tech); Wang, Fei [ORNL

2010-01-01T23:59:59.000Z

346

Transverse electromagnetic horn antenna with resistively-loaded exterior surfaces  

DOE Patents [OSTI]

An improved transverse electromagnetic (TEM) horn antenna comprises a resistive loading material on the exterior surfaces of the antenna plates. The resistive loading material attenuates or inhibits currents on the exterior surfaces of the TEM horn antenna. The exterior electromagnetic fields are of opposite polarity in comparison to the primary and desired interior electromagnetic field, thus inherently cause partial cancellation of the interior wave upon radiation or upon reception. Reducing the exterior fields increases the radiation efficiency of the antenna by reducing the cancellation of the primary interior field (supported by the interior surface currents). This increases the transmit gain and receive sensitivity of the TEM horn antenna, as well as improving the transient (time-domain) response.

Aurand, John F. (Edgewood, NM)

1999-01-01T23:59:59.000Z

347

ELECTROMAGNETIC COMPATIBILITY AND RENEWABLE POWER FOR IMPLANTABLE NEUROSTIMULATORS  

E-Print Network [OSTI]

J, Bakker P: Electromagnetic interference from radiomaking electromagnetic interference neurostimulator functioninclude electromagnetic interference and battery failure. In

Pantchenko, Oxana S.

2012-01-01T23:59:59.000Z

348

Electromagnetic analysis of nanostructure dispersion in polymer matrices  

E-Print Network [OSTI]

P. R. , “Enhanced electromagnetic interference shielding40] Chung D. D. L. “Electromagnetic Interference Shieldingreinforcement, electromagnetic interference shielding, etc.

Pfeifer, Steven Charles; Pfeifer, Steven Charles

2012-01-01T23:59:59.000Z

349

Cerro Prieto geothermal field: exploration during exploitation  

SciTech Connect (OSTI)

Geological investigations at Momotombo included photogeology, field mapping, binocular microscope examination of cuttings, and drillhole correlations. Among the geophysical techniques used to investigate the field sub-structure were: Schlumberger and electromagnetic soundings, dipole mapping and audio-magnetotelluric surveys, gravity and magnetic measurements, frequency domain soundings, self-potential surveys, and subsurface temperature determinations. The geochemical program analyzed the thermal fluids of the surface and in the wells. The description and results of exploration methods used during the investigative stages of the Momotombo Geothermal Field are presented. A conceptual model of the geothermal field was drawn from the information available at each exploration phase. The exploration methods have been evaluated with respect to their contributions to the understanding of the field and their utilization in planning further development.

Not Available

1982-07-01T23:59:59.000Z

350

Electromagnetic Compatibility in Nuclear Power Plants  

SciTech Connect (OSTI)

Electromagnetic compatibility (EMC) has long been a key element of qualification for mission critical instrumentation and control (I&C) systems used by the U.S. military. The potential for disruption of safety-related I&C systems by electromagnetic interference (EMI), radio-frequency interference (RFI), or power surges is also an issue of concern for the nuclear industry. Experimental investigations of the potential vulnerability of advanced safety systems to EMI/RFI, coupled with studies of reported events at nuclear power plants (NPPs) that are attributed to EMI/RFI, confirm the safety significance of EMC for both analog and digital technology. As a result, Oak Ridge National Laboratory has been engaged in the development of the technical basis for guidance that addresses EMC for safety-related I&C systems in NPPs. This research has involved the identification of engineering practices to minimize the potential impact of EMI/RFI and power surges and an evaluation of the ambient electromagnetic environment at NPPs to tailor those practices for use by the nuclear industry. Recommendations for EMC guidance have been derived from these research findings and are summarized in this paper.

Ewing, P.D.; Kercel, S.W.; Korsah, K.; Wood, R.T.

1999-08-29T23:59:59.000Z

351

Sub-Nyquist Field Trial Using Time Frequency Packed DP-QPSK Super-Channel Within Fixed ITU-T Grid  

E-Print Network [OSTI]

Sub-Nyquist time frequency packing technique was demonstrated for the first time in a super channel field trial transmission over long-haul distances. The technique allows a limited spectral occupancy even with low order modulation formats. The transmission was successfully performed on a deployed Australian link between Sydney and Melbourne which included 995 km of uncompensated SMF with coexistent traffic. 40 and 100 Gb/s co-propagating channels were transmitted together with the super-channel in a 50 GHz ITU-T grid without additional penalty. The super-channel consisted of eight sub-channels with low-level modulation format, i.e. DP-QPSK, guaranteeing better OSNR robustness and reduced complexity with respect to higher order formats. At the receiver side, coherent detection was used together with iterative maximum-a-posteriori (MAP) detection and decoding. A 975 Gb/s DP-QPSK super-channel was successfully transmitted between Sydney and Melbourne within four 50GHz WSS channels (200 GHz). A maximum potential...

Potì, L; Berrettini, G; Fresi, F; Foggi, T; Secondini, M; Giorgi, L; Cavaliere, F; Hackett, S; Petronio, A; Nibbs, P; Forgan, R; Leong, A; Masciulli, R; Pfander, C

2015-01-01T23:59:59.000Z

352

Electromagnetic Probes in PHENIX  

E-Print Network [OSTI]

Electromagnetic probes are arguably the most universal tools to study the different physics processes in high energy hadron and heavy ion collisions. In this paper we summarize recent measurements of real and virtual direct photons at central rapidity by the PHENIX experiment at RHIC in p+p, d+Au and Au+Au collisions. We also discuss the impact of the results and the constraints they put on theoretical models. At the end we report on the immediate as well as on the mid-term future of photon measurements at RHIC.

Gabor David

2006-09-21T23:59:59.000Z

353

Electromagnetic pump stator coil  

DOE Patents [OSTI]

An electrical stator coil for an electromagnetic pump includes a continuous conductor strip having first and second terminals at opposite ends thereof and an intermediate section disposed therebetween. The strip is configured in first and second coil halves, with the first coil half including a plurality of windings extending from the first terminal to the intermediate section, and the second coil half including a plurality of windings extending from the second terminal to the intermediate section. The first and second coil halves are disposed coaxially, and the first and second terminals are disposed radially inwardly therefrom with the intermediate section being disposed radially outwardly therefrom. 9 figs.

Fanning, A.W.; Dahl, L.R.

1996-06-25T23:59:59.000Z

354

Electromagnetic couplings of elementary vector particles  

E-Print Network [OSTI]

On the basis of the three fundamental principles of (i) Poincar\\'{e} symmetry of space time, (ii) electromagnetic gauge symmetry, and (iii) unitarity, we construct an universal Lagrangian for the electromagnetic interactions of elementary vector particles, i.e., massive spin-1 particles transforming in the /1/2,1/2) representation space of the Homogeneous Lorentz Group (HLG). We make the point that the first two symmetries alone do not fix the electromagnetic couplings uniquely but solely prescribe a general Lagrangian depending on two free parameters, here denoted by \\xi and g. The first one defines the electric-dipole and the magnetic-quadrupole moments of the vector particle, while the second determines its magnetic-dipole and electric-quadrupole moments. In order to fix the parameters one needs an additional physical input suited for the implementation of the third principle. As such, one chooses Compton scattering off a vector target and requires the cross section to respect the unitarity bounds in the high energy limit. In result, we obtain the universal g=2, and \\xi=0 values which completely characterize the electromagnetic couplings of the considered elementary vector field at tree level. The nature of this vector particle, Abelian versus non-Abelian, does not affect this structure. Merely, a partition of the g=2 value into non-Abelian, g_{na}, and Abelian, g_{a}=2-g_{na}, contributions occurs for non-Abelian fields with the size of g_{na} being determined by the specific non-Abelian group appearing in the theory of interest, be it the Standard Model or any other theory.

M. Napsuciale; S. Rodriguez; E. G. Delgado-Acosta; M. Kirchbach

2007-11-27T23:59:59.000Z

355

Electromagnetic fuel injector  

SciTech Connect (OSTI)

This patent describes an electromagnetic fuel injector for an internal combustion engine having a valve axis and including a housing, a flat armature connected to a movable valve element arranged to cooperate with a valve seat, spring means for exerting a force in an axial direction on the armature, and electromagnetic means for exerting a force in an opposite direction on the armature when electrically energized. The improvement comprises: the spring means being a helical coil spring disposed in substantially coaxial alignment with the valve axis and having an end in compressive engagement with the armature, the final coil which includes the end of the coil spring being inclined axially outward at an angle relative to a plane normal to the axis of the spring so as to apply to the armature a greater axial spring force to one side of the valve axis than the other thereby to effect pivoting of the armature about a pivot, the pivot being determined by the location of the end of the coil spring.

Gieseking, J.H.

1987-04-28T23:59:59.000Z

356

Entanglement of two-qubit photon beam by magnetic field  

E-Print Network [OSTI]

We have studied the possibility of affecting the entanglement measure of 2-qubit system consisting of two photons with different fixed frequencies but with two arbitrary linear polarizations, moving in the same direction, by the help of an applied external magnetic field. The interaction between the magnetic field and the photons in our model is achieved through intermediate electrons that interact with both the photons and the magnetic field. The possibility of exact theoretical analysis of this scheme is based on known exact solutions that describe the interaction of an electron subjected to an external magnetic field (or a medium of electrons not interacting with each other) with a quantized field of two photons. We adapt these exact solutions to the case under consideration. Using explicit wave functions for the resulting electromagnetic field, we calculate the entanglement measure of the photon beam as a function of the applied magnetic field and parameters of the electron medium.

A. D. Levin; D. M. Gitman; R. C. Castro

2014-09-05T23:59:59.000Z

357

Electromagnetic neutrino: a short review  

E-Print Network [OSTI]

A short review on selected issues related to the problem of neutrino electromagnetic properties is given. After a flash look at the theoretical basis of neutrino electromagnetic form factors, constraints on neutrino magnetic moments and electric millicharge from terrestrial experiments and astrophysical observations are discussed. We also focus on some recent studies of the problem and on perspectives.

Alexander I. Studenikin

2014-11-09T23:59:59.000Z

358

Microfabricated ion frequency standard  

DOE Patents [OSTI]

A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

Schwindt, Peter (Albuquerque, NM); Biedermann, Grant (Albuquerque, NM); Blain, Matthew G. (Albuquerque, NM); Stick, Daniel L. (Albuquerque, NM); Serkland, Darwin K. (Albuquerque, NM); Olsson, III, Roy H. (Albuquerque, NM)

2010-12-28T23:59:59.000Z

359

Spacetime algebra as a powerful tool for electromagnetism  

E-Print Network [OSTI]

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.

Justin Dressel; Konstantin Y. Bliokh; Franco Nori

2014-12-03T23:59:59.000Z

360

Controlled Source Frequency-Domain Electromagnetics At Neal Hot...  

Open Energy Info (EERE)

efforts. Software provided by Zonge International was used for the interpretation process. Interpretations show that the production fault dips west and trends north-south and...

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Controlled Source Frequency-Domain Electromagnetics At Neal Hot Springs  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentratingRenewable Solutions LLC Jump to:Information New York

362

Controlled Source Frequency-Domain Electromagnetics At Neal Hot Springs  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentratingRenewable Solutions LLC Jump to:Information New YorkGeothermal Area (Shaltry, 2012)

363

Frequency-Domain Electromagnetic Survey | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to: navigation, search Equivalent URI DBpediaFredonia,Iowa BioProcess

364

Frequency-Domain Electromagnetic Survey | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to: navigation, search Equivalent URI DBpediaFredonia,Iowa BioProcess

365

Frequency-Domain Electromagnetics Survey At Kilauea East Rift Geothermal  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to: navigation, search Equivalent URI DBpediaFredonia,Iowa BioProcessArea (FURUMOTO, 1976)

366

Airborne electromagnetic surveys as a reconnaissance technique...  

Open Energy Info (EERE)

Airborne electromagnetic surveys as a reconnaissance technique for geothermal exploration Abstract INPUT airborne electromagnetic (AEM) surveys were conducted during 1979 in five...

367

Quantization of the Classical Maxwell-Nordstrom Fields  

E-Print Network [OSTI]

The classical electromagnetic and gravitomagnetic fields in the vacuum, in (3+2) dimensions, described by the Maxwell-Nordstrom equations, are quantized. These equations are rederived from the field tensor which follows from a five-dimensional form of the Dirac equation. The electromagnetic field depends on the customary time t, and the hypothetical gravitomagnetic field depends on the second time variable u. The total field energy is identified with the component T44 of the five-dimensional energy-stress tensor of the electromagnetic and gravitomagnetic fields. In the ground state, the electromagnetic field and the gravitomagnetic field energies cancel out. The quanta of the gravitomagnetic field have spin 1.

J. Kocinski

2004-11-10T23:59:59.000Z

368

A fast multigrid-based electromagnetic eigensolver for curved metal boundaries on the Yee mesh  

SciTech Connect (OSTI)

For embedded boundary electromagnetics using the Dey–Mittra (Dey and Mittra, 1997) [1] algorithm, a special grad–div matrix constructed in this work allows use of multigrid methods for efficient inversion of Maxwell’s curl–curl matrix. Efficient curl–curl inversions are demonstrated within a shift-and-invert Krylov-subspace eigensolver (open-sourced at ([ofortt]https://github.com/bauerca/maxwell[cfortt])) on the spherical cavity and the 9-cell TESLA superconducting accelerator cavity. The accuracy of the Dey–Mittra algorithm is also examined: frequencies converge with second-order error, and surface fields are found to converge with nearly second-order error. In agreement with previous work (Nieter et al., 2009) [2], neglecting some boundary-cut cell faces (as is required in the time domain for numerical stability) reduces frequency convergence to first-order and surface-field convergence to zeroth-order (i.e. surface fields do not converge). Additionally and importantly, neglecting faces can reduce accuracy by an order of magnitude at low resolutions.

Bauer, Carl A., E-mail: carl.bauer@colorado.edu [Department of Physics and the Center for Integrated Plasma Studies, University of Colorado, Boulder, CO 80309 (United States); Werner, Gregory R. [Department of Physics and the Center for Integrated Plasma Studies, University of Colorado, Boulder, CO 80309 (United States)] [Department of Physics and the Center for Integrated Plasma Studies, University of Colorado, Boulder, CO 80309 (United States); Cary, John R. [Department of Physics and the Center for Integrated Plasma Studies, University of Colorado, Boulder, CO 80309 (United States) [Department of Physics and the Center for Integrated Plasma Studies, University of Colorado, Boulder, CO 80309 (United States); Tech-X Corporation, Boulder, CO 80303 (United States)

2013-10-15T23:59:59.000Z

369

Nucleon Electromagnetic Form Factors  

SciTech Connect (OSTI)

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.

Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi

2007-10-01T23:59:59.000Z

370

Nonlinear interaction of intense electromagnetic waves with a magnetoactive electron-positron-ion plasma  

SciTech Connect (OSTI)

The nonlinear coupling between circularly polarized electromagnetic (CPEM) waves and acoustic-like waves in a magnetoactive electron-positron-ion (e-p-i) plasma is studied, taking into account the relativistic motion of electrons and positrons. The possibility of modulational instability and its growth rate as well as the envelope soliton formation and its characteristics in such plasmas are investigated. It is found that the growth rate of modulation instability increases in the case that ?{sub c}/?<1 (?{sub c} and ? are the electron gyrofrequency and the CPEM wave frequency, respectively) and decreases in the case that ?{sub c}/?>1. It is also shown that in a magnetoactive e-p-i plasma, the width of bright soliton increases/decreases in case of (?{sub c}/?)<1/(?{sub c}/?)>1 by increasing the magnetic field strength.

Khorashadizadeh, S. M.; Rastbood, E.; Zeinaddini Meymand, H. [Physics Department, University of Birjand, Birjand (Iran, Islamic Republic of)] [Physics Department, University of Birjand, Birjand (Iran, Islamic Republic of); Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)] [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)

2013-08-15T23:59:59.000Z

371

THE BIANCHI IDENTITIES, ELECTROMAGNETIC WAVES, AND CHARGE CONSERVATION IN THE P(4) THEORY OF  

E-Print Network [OSTI]

OF GRAVITATION AND ELECTROMAGNETISM J. H. Chilton and K. S. Hammon Department of Physics North Carolina State, namely the affine geometry of the P(4) = O(1, 3) R4 theory of gravitation and electromag- netism (Norris) theory one obtains a conservation law and a wave equation for the electromagnetic field that parallels

Norris, Larry K.

372

The momentum of an electromagnetic wave inside a dielectric  

SciTech Connect (OSTI)

The problem of assigning a momentum to an electromagnetic wave packet propagating inside an insulator has become known under the name of the Abraham–Minkowski controversy. In the present paper we re-examine this issue making the hypothesis that the forces exerted on an insulator by an electromagnetic field do not distinguish between polarization and free charges. Under this assumption we show that the Abraham expression for the radiation mechanical momentum is highly favored. -- Highlights: •We discuss an approximation to treat electrodynamics of a dielectric material. •We support the Abraham form for the electromagnetic momentum. •We deduce Snell’s law from the conservation of the Abraham momentum. •We show how to deal with the electric field discontinuity at the dielectric boundary.

Testa, Massimo, E-mail: massimo.testa@roma1.infn.it

2013-09-15T23:59:59.000Z

373

Impulsive cylindrical gravitational wave: one possible radiative form emitted from cosmic strings and corresponding electromagnetic response  

E-Print Network [OSTI]

The cosmic strings(CSs) may be one important source of gravitational waves(GWs), and it has been intensively studied due to its special properties such as the cylindrical symmetry. The CSs would generate not only usual continuous GW, but also impulsive GW that brings more concentrated energy and consists of different GW components broadly covering low-, intermediate- and high-frequency bands simultaneously. These features might underlie interesting electromagnetic(EM) response to these GWs generated by the CSs. In this paper, with novel results and effects, we firstly calculate the analytical solutions of perturbed EM fields caused by interaction between impulsive cylindrical GWs (would be one of possible forms emitted from CSs) and background celestial high magnetic fields or widespread cosmological background magnetic fields, by using rigorous Einstein - Rosen metric. Results show: perturbed EM fields are also in the impulsive form accordant to the GW pulse, and asymptotic behaviors of the perturbed EM fields are fully consistent with the asymptotic behaviors of the energy density, energy flux density and Riemann curvature tensor of corresponding impulsive cylindrical GWs. The analytical solutions naturally give rise to the accumulation effect which is proportional to the term of distance^1/2, and based on it, we for the first time predict potentially observable effects in region of the Earth caused by the EM response to GWs from the CSs.

H. Wen; F. Y. Li; Z. Y. Fang; A. Beckwith

2014-05-04T23:59:59.000Z

374

Electromagnetic wave scattering by small bodies  

E-Print Network [OSTI]

A reduction of the Maxwell's system to a Fredholm second-kind integral equation with weakly singular kernel is given for electromagnetic (EM) wave scattering by one and many small bodies. This equation is solved asymptotically as the characteristic size of the bodies tends to zero. The technique developed is used for solving the many-body EM wave scattering problem by rigorously reducing it to solving linear algebraic systems, completely bypassing the usage of integral equations. An equation is derived for the effective field in the medium, in which many small particles are embedded. A method for creating a desired refraction coefficient is outlined.

A. G. Ramm

2008-04-21T23:59:59.000Z

375

Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation  

DOE Patents [OSTI]

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.

Novack, Steven D.; Kotter, Dale K.; Pinhero, Patrick J.

2012-10-09T23:59:59.000Z

376

Structures, systems and methods for harvesting energy from electromagnetic radiation  

DOE Patents [OSTI]

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.

Novack, Steven D. (Idaho Falls, ID); Kotter, Dale K. (Shelley, ID); Pinhero, Patrick J. (Columbia, MO)

2011-12-06T23:59:59.000Z

377

Black Hole Thermodynamics and Electromagnetism  

E-Print Network [OSTI]

We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.

Burra G. Sidharth

2005-07-15T23:59:59.000Z

378

Electromagnetic Calorimeter for HADES  

E-Print Network [OSTI]

We propose to build the Electromagnetic calorimeter for the HADES di-lepton spectrometer. It will enable to measure the data on neutral meson production from nucleus-nucleus collisions, which are essential for interpretation of dilepton data, but are unknown in the energy range of planned experiments (2-10 GeV per nucleon). The calorimeter will improve the electron-hadron separation, and will be used for detection of photons from strange resonances in elementary and HI reactions. Detailed description of the detector layout, the support structure, the electronic readout and its performance studied via Monte Carlo simulations and series of dedicated test experiments is presented. The device will cover the total area of about 8 m^2 at polar angles between 12 and 45 degrees with almost full azimuthal coverage. The photon and electron energy resolution achieved in test experiments amounts to 5-6%/sqrt(E[GeV]) which is sufficient for the eta meson reconstruction with S/B ratio of 0.4% in Ni+Ni collisions at 8 AGeV. A purity of the identified leptons after the hadron rejection, resulting from simulations based on the test measurements, is better than 80% at momenta above 500 MeV/c, where time-of-flight cannot be used.

W. Czyzycki; E. Epple; L. Fabbietti; M. Golubeva; F. Guber; A. Ivashkin; M. Kajetanowicz; A. Krasa; F. Krizek; A. Kugler; K. Lapidus; E. Lisowski; J. Pietraszko; A. Reshetin; P. Salabura; Y. Sobolev; J. Stanislav; P. Tlusty; T. Torrieri; M. Traxler

2011-11-28T23:59:59.000Z

379

Electromagnetic Calorimeter for HADES  

E-Print Network [OSTI]

We propose to build the Electromagnetic calorimeter for the HADES di-lepton spectrometer. It will enable to measure the data on neutral meson production from nucleus-nucleus collisions, which are essential for interpretation of dilepton data, but are unknown in the energy range of planned experiments (2-10 GeV per nucleon). The calorimeter will improve the electron-hadron separation, and will be used for detection of photons from strange resonances in elementary and HI reactions. Detailed description of the detector layout, the support structure, the electronic readout and its performance studied via Monte Carlo simulations and series of dedicated test experiments is presented. The device will cover the total area of about 8 m^2 at polar angles between 12 and 45 degrees with almost full azimuthal coverage. The photon and electron energy resolution achieved in test experiments amounts to 5-6%/sqrt(E[GeV]) which is sufficient for the eta meson reconstruction with S/B ratio of 0.4% in Ni+Ni collisions at 8 AGeV....

Czyzycki, W; Fabbietti, L; Golubeva, M; Guber, F; Ivashkin, A; Kajetanowicz, M; Krasa, A; Krizek, F; Kugler, A; Lapidus, K; Lisowski, E; Pietraszko, J; Reshetin, A; Salabura, P; Sobolev, Y; Stanislav, J; Tlusty, P; Torrieri, T; Traxler, M

2011-01-01T23:59:59.000Z

380

Immunizing digital systems against electromagnetic interference  

SciTech Connect (OSTI)

This paper discusses the development of the technical basis for acceptance criteria applicable to the immunization of digital systems against electromagnetic interference (EMI). The work is sponsored by the US Nuclear Regulatory Commission and stems from the safety-related issues that need to be addressed as a result of the application of digital instrumentation and control systems in nuclear power plants. Designers of digital circuits are incorporating increasingly higher clock frequencies and lower logic level voltages, thereby leading to potentially greater susceptibility of spurious interference being misinterpreted as legitimate logic. Development of the technical basis for acceptance criteria to apply to these digital systems centers around establishing good engineering practices to ensure that sufficient levels of electromagnetic compatibility (EMC) are maintained between the nuclear power plant`s electronic and electromechanical systems. First, good EMC design and installation practices are needed to control the emissions from interference sources and thereby their impact on other nearby circuits and systems. Secondly, a test and evaluation program is needed to outline the EMI tests to be performed, the associated test methods to be followed, and adequate test limits to ensure that the circuit or system under test meets the recommended guidelines. Test and evaluation should be followed by periodic maintenance to assess whether the recommended EMI control practices continue to be adhered to as part of the routine operation of the nuclear power plant. By following these steps, the probability of encountering safety-related instrumentation problems associated with EMI will be greatly reduced.

Ewing, P.D.; Korsah, K. [Oak Ridge National Lab., TN (United States); Antonescu, C. [Nuclear Regulatory Commission, Washington, DC (United States). Office of Nuclear Regulatory Research

1993-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
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381

Immunizing digital systems against electromagnetic interference  

SciTech Connect (OSTI)

This paper discusses the development of the technical basis for acceptance criteria applicable to the immunization of digital systems against electromagnetic interference (EMI). The work is sponsored by the US Nuclear Regulatory Commission and stems from the safety-related issues that need to be addressed as a result of the application of digital instrumentation and control systems in nuclear power plants. Designers of digital circuits are incorporating increasingly higher clock frequencies and lower logic level voltages, thereby leading to potentially greater susceptibility of spurious interference being misinterpreted as legitimate logic. Development of the technical basis for acceptance criteria to apply to these digital systems centers around establishing good engineering practices to ensure that sufficient levels of electromagnetic compatibility (EMC) are maintained between the nuclear power plant's electronic and electromechanical systems. First, good EMC design and installation practices are needed to control the emissions from interference sources and thereby their impact on other nearby circuits and systems. Secondly, a test and evaluation program is needed to outline the EMI tests to be performed, the associated test methods to be followed, and adequate test limits to ensure that the circuit or system under test meets the recommended guidelines. Test and evaluation should be followed by periodic maintenance to assess whether the recommended EMI control practices continue to be adhered to as part of the routine operation of the nuclear power plant. By following these steps, the probability of encountering safety-related instrumentation problems associated with EMI will be greatly reduced.

Ewing, P.D.; Korsah, K. (Oak Ridge National Lab., TN (United States)); Antonescu, C. (Nuclear Regulatory Commission, Washington, DC (United States). Office of Nuclear Regulatory Research)

1993-01-01T23:59:59.000Z

382

Novel microwave near-field sensors for material characterization, biology, and nanotechnology  

E-Print Network [OSTI]

The wide range of interesting electromagnetic behavior of contemporary materials requires that experimentalists working in this field master many diverse measurement techniques and have a broad understanding of condensed matter physics and biophysics. Measurement of the electromagnetic response of materials at microwave frequencies is important for both fundamental and practical reasons. In this paper, we propose a novel near-field microwave sensor with application to material characterization, biology, and nanotechnology. The sensor is based on a subwavelength ferrite-disk resonator with magnetic-dipolar-mode (MDM) oscillations. Strong energy concentration and unique topological structures of the near fields originated from the MDM resonators allow effective measuring material parameters in microwaves, both for ordinary structures and objects with chiral properties.

Joffe, R; Shavit, R

2015-01-01T23:59:59.000Z

383

Conservation of the spin and orbital angular momenta in electromagnetism  

E-Print Network [OSTI]

We review and re-examine the description and separation of the spin and orbital angular momenta (AM) of an electromagnetic field in free space. While the spin and orbital AM of light are not separately-meaningful physical quantities in orthodox quantum mechanics or classical field theory, these quantities are routinely measured and used for applications in optics. A meaningful quantum description of the spin and orbital AM of light was recently provided by several authors, which describes separately conserved and measurable integral values of these quantities. However, the electromagnetic field theory still lacks corresponding locally-conserved spin and orbital AM currents. In this paper, we construct these missing spin and orbital AM densities and fluxes that satisfy the proper continuity equations. We show that these are physically measurable and conserved quantities. These are, however, not Lorentz-covariant, so only make sense in the single laboratory reference frame of the measurement probe. The fluxes we derive improve the canonical (non-conserved) spin and orbital AM fluxes, and include a `spin-orbit' term that describes the spin-orbit interaction effects observed in nonparaxial optical fields. We also consider both standard and dual-symmetric versions of the electromagnetic field theory. Applying the general theory to nonparaxial optical vortex beams validates our results and allows us to discriminate between earlier approaches to the problem. Our treatment yields the complete and consistent description of the spin and orbital AM of free Maxwell fields in both quantum-mechanical and field-theory approaches.

Konstantin Y. Bliokh; Justin Dressel; Franco Nori

2014-08-03T23:59:59.000Z

384

Ferrite material characterization in a static bias field for the design of a tuneable cavity  

E-Print Network [OSTI]

During the development of ferrite-loaded accelerating cavities, the electromagnetic properties of the dispersive ferrite material need to be known. We describe a coaxial short-circuit measurement technique to measure the complex permeability of toroidal-shaped samples (127mm outer and 70mm inner diameter) that are exposed to an external magnetic bias field. The external magnetic bias field is applied perpendicular to the RF magnetic field. With this method it is possible to characterize the frequency dependence of the permeability for a frequency range of 1- 100MHz. The dependence of the permeability on the external magnetic bias is presented for the ferrite G-510 from Trans-Tech Inc. and the material characterization is shown in the same frequency range. The measurement results are verified by simulations of the measurement set-up.

Eberhardt, J; Vollinger, C

2014-01-01T23:59:59.000Z

385

Graded pitch electromagnetic pump for thin strip metal casting systems  

DOE Patents [OSTI]

A metal strip casing system is provided with an electromagnetic pump which includes a pair of primary blocks having a graded pole pitch, polyphase ac winding and being arranged on opposite sides of a movable heat sink. A nozzle is provided for depositing liquid metal on the heat sink such that the resulting metal strip and heat sink combination is subjected to a longitudinal electromagnetic field which increases in wavelength in the direction of travel of the heat sink, thereby subjecting the metal and heat sink to a longitudinal force having a magnitude which increases in the direction of travel. 4 figs.

Kuznetsov, S.B.

1986-04-01T23:59:59.000Z

386

Graded pitch electromagnetic pump for thin strip metal casting systems  

DOE Patents [OSTI]

A metal strip casing system is provided with an electromagnetic pump which includes a pair of primary blocks having a graded pole pitch, polyphase ac winding and being arranged on opposite sides of a movable heat sink. A nozzle is provided for depositing liquid metal on the heat sink such that the resulting metal strip and heat sink combination is subjected to a longitudinal electromagnetic field which increases in wavelength in the direction of travel of the heat sink, thereby subjecting the metal and heat sink to a longitudinal force having a magnitude which increases in the direction of travel.

Kuznetsov, Stephen B. (Pittsburgh, PA)

1986-01-01T23:59:59.000Z

387

Electromagnetic low-energy constants in ChPT  

E-Print Network [OSTI]

We investigate three-flavour chiral perturbation theory including virtual photons in a limit where the strange quark mass is much larger than the external momenta and the up and down quark masses, and where the external fields are those of two-flavour chiral perturbation theory. In particular we work out the strange quark mass dependence of the electromagnetic two-flavour low-energy constants C and k_i. We expect that these relations will be useful for a more precise determination of the electromagnetic low-energy constants.

Christoph Haefeli; Mikhail A. Ivanov; Martin Schmid

2007-10-29T23:59:59.000Z

388

Analog Electromagnetism in a Symmetrized $^3$He-A  

E-Print Network [OSTI]

We derive a low temperature effective action for the order parameter in a symmetrized phase A of helium 3, where the Fermi velocity equals the transversal velocity of low energy fermionic quasiparticles. The effective action has a form of the electromagnetic action. This analog electromagnetism is a part of the program to derive analog gravity and the standard model as a low energy effective theory in a condensed matter system. For the analog gauge field to satisfy the Maxwell equations interactions in $^3$He require special tuning that leads to the symmetric case.

Jacek Dziarmaga

2001-12-18T23:59:59.000Z

389

Electromagnetic solitary pulses in a magnetized electron-positron plasma  

SciTech Connect (OSTI)

A theory for large amplitude compressional electromagnetic solitary pulses in a magnetized electron-positron (e-p) plasma is presented. The pulses, which propagate perpendicular to the external magnetic field, are associated with the compression of the plasma density and the wave magnetic field. Here the solitary wave magnetic field pressure provides the restoring force, while the inertia comes from the equal mass electrons and positrons. The solitary pulses are formed due to a balance between the compressional wave dispersion arising from the curl of the inertial forces in Faraday's law and the nonlinearities associated with the divergence of the electron and positron fluxes, the nonlinear Lorentz forces, the advection of the e-p fluids, and the nonlinear plasma current densities. The compressional solitary pulses can exist in a well-defined speed range above the Alfven speed. They can be associated with localized electromagnetic field excitations in magnetized laboratory and space plasmas composed of electrons and positrons.

Shukla, P. K. [RUB International Chair, International Centre for Advanced Studies in Physical Sciences, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Eliasson, B. [Institut fuer Theoretische Physik, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Stenflo, L. [Department of Physics, Linkoeping University, SE-58183 Linkoeping (Sweden)

2011-03-15T23:59:59.000Z

390

Plasmon decay to a neutrino pair via neutrino electromagnetic moments in a strongly magnetized medium  

E-Print Network [OSTI]

We calculate the neutrino luminosity of a degenerate electron gas in a strong magnetic field via plasmon decay to a neutrino pair due to neutrino electromagnetic moments and obtain the relative upper bounds on the effective neutrino magnetic moment.

A. V. Borisov; P. E. Sizin

2014-06-12T23:59:59.000Z

391

Generation and coherent control of even-order harmonics driven by intense frequency-comb and cavity-mode fields inside a fsEC  

E-Print Network [OSTI]

Generation and coherent control of even-order harmonics driven by intense frequency-comb and cavity) doi:10.1088/0953-4075/46/14/145403 Generation and coherent control of even-order harmonics driven, resulting in the generation of even-order harmonics. The high-order harmonic generation (HHG) from a two

Chu, Shih-I

392

On the electromagnetic constitutive laws that are equivalent to spacetime metrics  

E-Print Network [OSTI]

The raising of both indices in the components of the Minkowski electromagnetic field strength 2-form to give the components of the electromagnetic excitation bivector field can be regarded as being equivalent to an electromagnetic constitutive law, as well as being defined by the components of the spacetime metric. This notion is clarified, and the nature of the equivalent dielectric tensors and magnetic permeability tensors that are defined by some common spacetime metrics is discussed. The relationship of the basic construction to effective metrics is discussed, and, in particular, the fact that this effective metric is more general than the Gordon metric.

D. H. Delphenich

2014-09-17T23:59:59.000Z

393

Surface electromagnetic wave equations in a warm magnetized quantum plasma  

SciTech Connect (OSTI)

Based on the single-fluid plasma model, a theoretical investigation of surface electromagnetic waves in a warm quantum magnetized inhomogeneous plasma is presented. The surface electromagnetic waves are assumed to propagate on the plane between a vacuum and a warm quantum magnetized plasma. The quantum magnetohydrodynamic model includes quantum diffraction effect (Bohm potential), and quantum statistical pressure is used to derive the new dispersion relation of surface electromagnetic waves. And the general dispersion relation is analyzed in some special cases of interest. It is shown that surface plasma oscillations can be propagated due to quantum effects, and the propagation velocity is enhanced. Furthermore, the external magnetic field has a significant effect on surface wave's dispersion equation. Our work should be of a useful tool for investigating the physical characteristic of surface waves and physical properties of the bounded quantum plasmas.

Li, Chunhua; Yang, Weihong [Department of Modern Physics, University of Science and Technology of China, 230026 Hefei (China); Wu, Zhengwei, E-mail: wuzw@ustc.edu.cn [Department of Modern Physics, University of Science and Technology of China, 230026 Hefei (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Center of Low Temperature Plasma Application, Yunnan Aerospace Industry Company, Kunming, 650229 Yunnan (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

2014-07-15T23:59:59.000Z

394

Elimination of Radio-Frequency Noise by Identifying and Diverting Large RF Ground Currents  

SciTech Connect (OSTI)

The problem of electromagnetic interference in scientific instruments is compounded for high-power plasma experiments by the large currents and voltages as well as by the broad bandwidths of the instruments. Ground loops are known to allow stray magnetic fields to drive large ground currents that can induce spurious signals and damage electronics. Furthermore, even when a ground loop is broken, capacitive coupling can still permit the flow of radio-frequency current, resulting in high-frequency spurious signals that can overwhelm the desired signal. We present the effects of RF ground loops on the output of vacuum photodiodes used in the Caltech Solar Loop Experiment and demonstrate the elimination of the spurious signals by diverting the ground currents away from the most vulnerable point of the signal line. Techniques for identifying the RF ground loops are also discussed. These techniques should be valuable in many high-power systems where interference from spurious coupling is an issue.

Perkins, R. J.; Bellan, P. M. [Applied Physics, California Institute of Technology (United States)

2011-12-23T23:59:59.000Z

395

Combined gravitational and electromagnetic self-force on charged particles in electrovac spacetimes  

E-Print Network [OSTI]

We consider the self-force on a charged particle moving in a curved spacetime with a background electromagnetic field, extending previous studies to situations in which gravitational and electromagnetic perturbations are comparable. The formal expression $f^{ret}_\\alpha$ for the self-force on a particle, written in terms of the retarded perturbed fields, is divergent, and a renormalization is needed to find the particle's acceleration at linear order in its mass $m$ and charge $e$. We assume that, as in previous work in a Lorenz gauge, the renormalization for accelerated motion comprises an angle average and mass renormalization. Using the short distance expansion of the perturbed electromagnetic and gravitational fields, we show that the renormalization is equivalent to that obtained from a mode sum regularization in which one subtracts from the expression for the self-force in terms of the retarded fields a singular part field comprising only the leading and subleading terms in the mode sum. The most striking part of our result, arising from a remarkable cancellation, is that the renormalization involves no mixing of electromagnetic and gravitational fields. In particular, the renormalized mass is obtained by subtracting (1) the purely electromagnetic contribution from a point charge moving along an accelerated trajectory and (2) the purely gravitational contribution from a point mass moving along the same trajectory. In a mode-sum regularization, the same cancellation implies that the required regularization parameters are sums of their purely electromagnetic and gravitational values.

Thomas M. Linz; John L. Friedman; Alan G. Wiseman

2014-06-19T23:59:59.000Z

396

Electromagnetic compatibility in semiconductor manufacturing  

SciTech Connect (OSTI)

Electromagnetic Interference (EMI) causes problems in semiconductor manufacturing facilities that range from nuisances to major disruptions of production. In many instances, these issues are addressed in a reactionary rather than proactive manner by individuals who do not have the experience or the equipment necessary to combat EMI problems in a timely, cost effective manner. This approach leads to expensive retrofits, reduced equipment availability, long recovery times, and in some cases, line yield impacts. The goal of electromagnetic compatibility (EMC) in semiconductor manufacturing is to ensure that semiconductor process, metrology, and support equipment operate as intended without being affected by electromagnetic disturbances either transmitted through air (radiated interference), or transferred into the equipment via a conductive media (conducted interference). Rather than being neglected until serious issues arise, EMC should be considered in the early stages of facility design, in order to gain the most benefit at the lowest cost.

Montoya, J.A. [Intel Corp., Hillsboro, OR (United States)

1995-12-31T23:59:59.000Z

397

Electromagnetic radiation by gravitating bodies  

E-Print Network [OSTI]

Gravitating bodies in motion, regardless of their constitution, always produce electromagnetic radiation in the form of photon pairs. This phenomenon is an analog of the radiation caused by the motion of dielectric (or magnetic) bodies. It is a member of a wide class of phenomena named dynamical Casimir effects, and it may be viewed as the squeezing of the electromagnetic vacuum. Production of photon pairs is a purely quantum-mechanical effect. Unfortunately, as we show, the emitted radiation is extremely weak as compared to radiation produced by other mechanisms.

Iwo Bialynicki-Birula; Zofia Bialynicka-Birula

2008-05-06T23:59:59.000Z

398

Perfectly Reflectionless Omnidirectional Electromagnetic Absorber  

E-Print Network [OSTI]

We demonstrate the existence of metamaterial blueprints describing, and fundamental limitations concerning, perfectly reflectionless omnidirectional electromagnetic absorbers (PR-OEMA). Previous attempts to define PR-OEMA blueprints have led to active (gain), rather than passive, media. We explain this fact and unveil new, distinct limitations of true PR-OEMA devices including the appearance of an "electromagnetic horizon" on physical solutions. As practical alternatives, we introduce two new OEMA blueprints. While these two blueprints do not correspond to reflectionless media, they are effective in absorbing incident waves in a manner robust to incident wave diversity.

Sainath, Kamalesh

2014-01-01T23:59:59.000Z

399

INTERPRETATION OF AIRBORNE ELECTROMAGNETIC AND MAGNETIC DATA IN THE 600 AREA  

SciTech Connect (OSTI)

As part of the 200-PO-1 Phase I geophysical surveys, Fugro Airborne Surveys was contracted to collect airborne electromagnetic (EM) and magnetic surveys of the Hanford Site 600 Area. Two helicopter survey systems were used with the HeliGEOTEM{reg_sign} time domain portion flown between June 19th and June 20th, 2008, and the RESOLVE{reg_sign} frequency domain portion was flown from June 29th to July 1st, 2008. Magnetic data were acquired contemporaneously with the electromagnetic surveys using a total-field cesium vapor magnetometer. Approximately 925 line kilometers (km) were flown using the HeliGEOTEM{reg_sign} II system and 412 line kilometers were flown using the RESOLVE{reg_sign} system. The HeliGEOTEM system has an effective penetration of roughly 250 meters into the ground and the RESOLVE system has an effective penetration of roughly 60 meters. Acquisition parameters and preliminary results are provided in SGW-39674, Airborne Electromagnetic Survey Report, 200-PO-1 Groundwater Operable Unit, 600 Area, Hanford Site. Airborne data are interpreted in this report in an attempt to identify areas of likely preferential groundwater flow within the aquifer system based on the presence of paleochannels or fault zones. The premise for the interpretation is that coarser-grained intervals have filled in scour channels created by episodic catastrophic flood events during the late Pleistocene. The interpretation strategy used the magnetic field anomaly data and existing bedrock maps to identify likely fault or lineament zones. Combined analysis of the magnetic, 60-Hz noise monitor, and flight-altitude (radar) data were used to identify zones where EM response is more likely due to cultural interference and or bedrock structures. Cross-sectional and map view presentations of the EM data were used to identify more electrically resistive zones that likely correlate with coarser-grained intervals. The resulting interpretation identifies one major northwest-southeast trending preferential flowpath with several minor units running along a similar trend. This presumed path of preferential flow is compared with the tritium concentration levels observed for the 600 Area. Analysis of the magnetic field data shows the location of potential bedrock faults and lineaments which may influence the horizontal and vertical flow of water. Faults lying within, or in the vicinity of preferential groundwater flow paths may allow flow into or out of the otherwise confined basalt layers.

CUMMINS GD

2010-11-11T23:59:59.000Z

400

Electromagnetic design considerations for fast acting controllers  

SciTech Connect (OSTI)

Electromagnetic design considerations for fast acting controllers in a power system is introduced and defined. A distinction is made in relation to the more commonly understood system control design necessary for damping electromechanical oscillations using stability programs and eigenanalysis. Electromagnetic eigenanalysis tools have limited availability and are consequently rarely used. Electromagnetic transients programs (emtp) on the other hand are widely used and a procedure for undertaking electromagnetic control design of fast acting controllers in a power system using emtp is presented.

Woodford, D.A. [Manitoba HVDC Research Centre, Winnipeg, Manitoba (Canada)] [Manitoba HVDC Research Centre, Winnipeg, Manitoba (Canada)

1996-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

On the mechanism of electromagnetic microwave absorption in superfluid helium  

SciTech Connect (OSTI)

In experiments on electromagnetic (EM) wave absorption in the microwave range in superfluid (SF) helium [1-3], a narrow EM field absorption line with a width on the order of (20-200) kHz was observed against the background of a wide absorption band with a width of 30-40 GHz at frequencies f{sub 0} Almost-Equal-To 110-180 GHz corresponding to the roton gap energy {Delta}{sub r}(T) in the temperature range 1.4-2.2 K. Using the so-called flexoelectric mechanism of polarization of helium atoms ({sup 4}He) in the presence of density gradients in SF helium (HeII), we show that nonresonance microwave absorption in the frequency range 170-200 GHz can be due to the existence of time-varying local density gradients produced by roton excitations in the bulk HeII. The absorption bandwidth is determined by the roton-roton scattering time in an equilibrium Boltzmann gas of rotons, which is t{sub r-r} Almost-Equal-To 3.4 Multiplication-Sign 10{sup -11} s at T = 1.4 K and decreases upon heating. We propose that the anomalously narrow microwave resonance absorption line in HeII at the roton frequency f{sub 0}(T) = {Delta}r(T)/2{pi}h appears due to the following two factors: (i) the discrete structure of the spectrum of the surface EM resonator modes in the form of a periodic sequence of narrow peaks and (ii) the presence of a stationary dipole layer in HeII near the resonator surface, which forms due to polarization of {sup 4}He atoms under the action of the density gradient associated with the vanishing of the density of the SF component at the solid wall. For this reason, the relaxation of nonequilibrium rotons generated in such a surface dipole layer is strongly suppressed, and the shape and width of the microwave resonance absorption line are determined by the roton density of states, which has a sharp peak at the edge of the roton gap in the case of weak dissipation. The effective dipole moments of rotons in the dipole layer can be directed either along or across the normal to the resonator surface, which explains the experimentally observed symmetric doublet splitting of the resonance absorption line in an external dc electric field perpendicular to the resonator surface. We show that negative absorption (induced emission) of EM field quanta observed after triggering a Kapitza 'heat gun' occurs when the occupation numbers for roton states due to 'pumping' of rotons exceed the occupation numbers of EM field photons in the resonator.

Pashitskii, E. A., E-mail: pashitsk@iop.kiev.ua; Pentegov, V. I. [National Academy of Sciences of Ukraine, Institute of Physics (Ukraine)

2012-08-15T23:59:59.000Z

402

IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY, VOL. 55, NO. 2, APRIL 2013 395 Electromagnetic Interference Analysis of  

E-Print Network [OSTI]

to electromagnetic interference (EMI) is becoming a critical aspect of signal integrity analysis. For mod- eling in high-speed packages [2]. As a result, effi- cient and accurate electromagnetic interference (EMIIEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY, VOL. 55, NO. 2, APRIL 2013 395 Electromagnetic

Roy, Sourajeet

403

Radiation from electrons in graphene in strong electric field  

E-Print Network [OSTI]

We study the interaction of electrons in graphene with the quantized electromagnetic field in the presence of an applied uniform electric field using the Dirac model of graphene. Electronic states are represented by exact solutions of the Dirac equation in the electric background, and amplitudes of first-order Feynman diagrams describing the interaction with the photon field are calculated for massive Dirac particles in both valleys. Photon emission probabilities from a single electron and from a many-electron system at the charge neutrality point are derived, including the angular and frequency dependence, and several limiting cases are analyzed. The pattern of photon emission at the Dirac point in a strong field is determined by an interplay between the nonperturbative creation of electron-hole pairs and spontaneous emission, allowing for the possibility of observing the Schwinger effect in measurements of the radiation emitted by pristine graphene under DC voltage.

N. Yokomizo

2014-05-05T23:59:59.000Z

404

Three-dimensional electromagnetic modeling and inversion on massively parallel computers  

SciTech Connect (OSTI)

This report has demonstrated techniques that can be used to construct solutions to the 3-D electromagnetic inverse problem using full wave equation modeling. To this point great progress has been made in developing an inverse solution using the method of conjugate gradients which employs a 3-D finite difference solver to construct model sensitivities and predicted data. The forward modeling code has been developed to incorporate absorbing boundary conditions for high frequency solutions (radar), as well as complex electrical properties, including electrical conductivity, dielectric permittivity and magnetic permeability. In addition both forward and inverse codes have been ported to a massively parallel computer architecture which allows for more realistic solutions that can be achieved with serial machines. While the inversion code has been demonstrated on field data collected at the Richmond field site, techniques for appraising the quality of the reconstructions still need to be developed. Here it is suggested that rather than employing direct matrix inversion to construct the model covariance matrix which would be impossible because of the size of the problem, one can linearize about the 3-D model achieved in the inverse and use Monte-Carlo simulations to construct it. Using these appraisal and construction tools, it is now necessary to demonstrate 3-D inversion for a variety of EM data sets that span the frequency range from induction sounding to radar: below 100 kHz to 100 MHz. Appraised 3-D images of the earth`s electrical properties can provide researchers opportunities to infer the flow paths, flow rates and perhaps the chemistry of fluids in geologic mediums. It also offers a means to study the frequency dependence behavior of the properties in situ. This is of significant relevance to the Department of Energy, paramount to characterizing and monitoring of environmental waste sites and oil and gas exploration.

Newman, G.A.; Alumbaugh, D.L. [Sandia National Labs., Albuquerque, NM (United States). Geophysics Dept.

1996-03-01T23:59:59.000Z

405

Electromagnetic Induced Gravitational Perturbations  

E-Print Network [OSTI]

We study the physical consequences of two diffferent but closely related perturbation schemes applied to the Einstein-Maxwell equations. In one case the starting space-time is flat while in the other case it is Schwarzschild. In both cases the perturbation is due to a combined electric and magnetic dipole field. We can see, within the Einstein-Maxwell equations a variety of physical consequences. They range from induced gravitational energy-momentum loss, to a well defined spin angular momentum with its loss and a center-of-mass with its equations of motion.

T. M. Adamo; E. T. Newman

2008-07-23T23:59:59.000Z

406

611: Electromagnetic Theory Problem Sheet 5  

E-Print Network [OSTI]

611: Electromagnetic Theory Problem Sheet 5 (1a) The Null Energy Condition on an energy = (k, 0, 0, k), show that the energy-momentum tensor Tµ = 1 4 Fµ F - 1 4µ F F (1) for electromagnetism if the equality kµ k Tµ = 0 is attained. (2) Show that the energy-momentum tensor for electromagnetism can

Pope, Christopher

407

Electromagnetic Interrogation of Dielectric Materials 1  

E-Print Network [OSTI]

Electromagnetic Interrogation of Dielectric Materials 1 H.T. Banks M.W. Buksas Center for Research grant P200A40730. #12; Abstract We investigate time domain based electromagnetic inverse problems electromagnetic phenomenon. For our purposes, we categorize the materials and the models employed to describe them

408

Electromagnetic Corrections in Staggered Chiral Perturbation Theory  

E-Print Network [OSTI]

Electromagnetic Corrections in Staggered Chiral Perturbation Theory C. Bernard and E.D. Freeland perturbation theory including electromagnetism, and discuss the extent to which quenched-photon simulations can-lat]17Nov2010 #12;Electromagnetic Corrections in Staggered Chiral Perturbation Theory E.D. Freeland 1

Bernard, Claude

409

Physics 4: Introductory Physics Electromagnetism and Light  

E-Print Network [OSTI]

Physics 4: Introductory Physics Electromagnetism and Light Professor Jeffrey D. Richman Department: Electromagnetism and Light Welcome to Physics 4! What is your goal in life? If it is to become an engineer or to pursue a career in science, this is a key class for you. Understanding electromagnetism and light

Fygenson, Deborah Kuchnir

410

Electromagnetic Formation Flight of Satellite Arrays  

E-Print Network [OSTI]

Electromagnetic Formation Flight of Satellite Arrays Daniel W. Kwon and David W. Miller February 2005 SSL # 2-05 #12;#12;Electromagnetic Formation Flight of Satellite Arrays By DANIEL W. KWON S;#12;Electromagnetic Formation Flight of Satellite Arrays by DANIEL W. KWON Submitted to the Department of Aeronautics

411

Electromagnetic and nuclear radiation detector using micromechanical sensors  

DOE Patents [OSTI]

Electromagnetic and nuclear radiation is detected by micromechanical sensors that can be coated with various interactive materials. As the micromechanical sensors absorb radiation, the sensors bend and/or undergo a shift in resonance characteristics. The bending and resonance changes are detected with high sensitivity by any of several detection methods including optical, capacitive, and piezoresistive methods. Wide bands of the electromagnetic spectrum can be imaged with picoJoule sensitivity, and specific absorptive coatings can be used for selective sensitivity in specific wavelength bands. Microcantilevers coated with optical cross-linking polymers are useful as integrating optical radiation dosimeters. Nuclear radiation dosimetry is possible by fabricating cantilevers from materials that are sensitive to various nuclear particles or radiation. Upon exposure to radiation, the cantilever bends due to stress and its resonance frequency shifts due to changes in elastic properties, based on cantilever shape and properties of the coating.

Thundat, Thomas G. (Knoxville, TN); Warmack, Robert J. (Knoxville, TN); Wachter, Eric A. (Oak Ridge, TN)

2000-01-01T23:59:59.000Z

412

Characterization of the coherent noise, electromagnetic compatibility and electromagnetic interference of the ATLAS EM calorimeter Front End Board  

E-Print Network [OSTI]

Characterization of the coherent noise, electromagnetic compatibility and electromagnetic interference of the ATLAS EM calorimeter Front End Board

Chase, B E; Lanni, F; Makowiecki, D S; Radeka, V; Rescia, S; Takai, H; Bán, J; Parsons, J; Sippach, W

1999-01-01T23:59:59.000Z

413

Experimental test of the compatibility of the definitions of the electromagnetic energy density and the Poynting vector  

E-Print Network [OSTI]

It is shown that the generally accepted definition of the Poynting vector and the energy flux vector defined by means of the energy density of the electromagnetic field (Umov vector) lead to the prediction of the different results touching electromagnetic energy flux. The experiment shows that within the framework of the mentioned generally accepted definitions the Poynting vector adequately describes the electromagnetic energy flux unlike the Umov vector. Therefore one can conclude that a generally accepted definitions of the electromagnetic energy density and the Poynting vector, in general, are not always compatible.

Andrew Chubykalo; Augusto Espinoza; Rumen Tzonchev

2005-03-24T23:59:59.000Z

414

Semiclassical Estimates of Electromagnetic Casimir Self-Energies of Spherical and Cylindrical Metallic Shells  

E-Print Network [OSTI]

The leading semiclassical estimates of the electromagnetic Casimir stresses on a spherical and a cylindrical metallic shell are within 1% of the field theoretical values. The electromagnetic Casimir energy for both geometries is given by two decoupled massless scalars that satisfy conformally covariant boundary conditions. Surface contributions vanish for smooth metallic boundaries and the finite electromagnetic Casimir energy in leading semiclassical approximation is due to quadratic fluctuations about periodic rays in the interior of the cavity only. Semiclassically the non-vanishing Casimir energy of a metallic cylindrical shell is almost entirely due to Fresnel diffraction.

Martin Schaden

2010-06-16T23:59:59.000Z

415

Faraday Acceleration with Radio-frequency Assisted Discharge (FARAD) Edgar Y. Choueiri  

E-Print Network [OSTI]

. Polzin Electric Propulsion and Plasma Dynamics Laboratory (EPPDyL) Mechanical and Aerospace Engineering electrodeless accelerator concept that relies on an RF-assisted discharge, an applied magnetic field efficient plasma production, magnetic field guided mass injection, and electromagnetic acceleration

Choueiri, Edgar

416

Proceedings ofAsia-Pacific Microwave Conference 2007 Agricultural Applications for Electromagnetic  

E-Print Network [OSTI]

Proceedings ofAsia-Pacific Microwave Conference 2007 Agricultural Applications for Electromagnetic treatment for anti-freezing operation, pre-harvest Sunne pest control, and Orchid flower control rate of energy in pistachio and sensitive objects is the most. This frequency depends

Paris-Sud XI, Université de

417

Dark Energy, Gravitation and Electromagnetism  

E-Print Network [OSTI]

In the context of the fact that the existence of dark energy causing the accelerated expansion of the universe has been confirmed by the WMAP and the Sloan Digital Sky Survey, we re-examine gravitation itself, starting with the formulation of Sakharov and show that it is possible to obtain gravitation in terms of the electromagnetic charge of elementary particles, once the ZPF and its effects at the Compton scale are taken into account.

B. G. Sidharth

2004-01-08T23:59:59.000Z

418

Laminated electromagnetic pump stator core  

DOE Patents [OSTI]

A stator core for an electromagnetic pump includes a plurality of circumferentially abutting tapered laminations extending radially outwardly from a centerline axis to collectively define a radially inner bore and a radially outer circumference. Each of the laminations includes radially inner and outer edges and has a thickness increasing from the inner edge toward the outer edge to provide a substantially continuous path adjacent the circumference. This pump is used in nuclear fission reactors. 19 figs.

Fanning, A.W.

1995-08-08T23:59:59.000Z

419

Shielding effectiveness against electromagnetic interference  

SciTech Connect (OSTI)

The use of metal-filled and metal-coated plastics and other modified dielectric materials to replace metals for enclosures has created a need to test these materials for their electromagnetic interference (EMI) shielding effectiveness (SE). Shielding effectiveness involves a variety of electromagnetic environments, and useful data can be obtained from tests that carefully limit the environment to that of a plane wave. Such an environment can be created in a circular or rectangular transmission line. Two such transmission line test fixtures, which hold samples of the material to be tested, have been developed. The fixtures described in this report are the National Bureau of Standards (NBS) coaxial transverse electromagnetic (TEM) cell, and a dual TEM cell constructed at ORNL from a design suggested by the NBS. The NBS coaxial fixture is an improved version of the device recommended by the American Society for Testing and Materials (ASTM). The problems associated with measuring SE are well described in the literature. The two methods described here are the result of years of work to establish procedures and instrumentation that will produce acceptable data.

Googe, J.M.; Hess, R.A.

1987-10-01T23:59:59.000Z

420

Antenna-coupled silicon-organic hybrid integrated photonic crystal modulator for broadband electromagnetic wave detection  

E-Print Network [OSTI]

In this work, we design, fabricate and characterize a compact, broadband and highly sensitive integrated photonic electromagnetic field sensor based on a silicon-organic hybrid modulator driven by a bowtie antenna. The large electro-optic (EO) coefficient of organic polymer, the slow-light effects in the silicon slot photonic crystal waveguide (PCW), and the broadband field enhancement provided by the bowtie antenna, are all combined to enhance the interaction of microwaves and optical waves, enabling a high EO modulation efficiency and thus a high sensitivity. The modulator is experimentally demonstrated with a record-high effective in-device EO modulation efficiency of r33=1230pm/V. Modulation response up to 40GHz is measured, with a 3-dB bandwidth of 11GHz. The slot PCW has an interaction length of 300um, and the bowtie antenna has an area smaller than 1cm2. The bowtie antenna in the device is experimentally demonstrated to have a broadband characteristics with a central resonance frequency of 10GHz, as we...

Zhang, Xingyu; Subbaraman, Harish; Wang, Shiyi; Zhan, Qiwen; Luo, Jingdong; Jen, Alex K -Y; Chung, Chi-jui; Yan, Hai; Pan, Zeyu; Nelson, Robert L; Lee, Charles Y -C; Chen, Ray T

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Electromagnetic power of merging and collapsing compact objects  

E-Print Network [OSTI]

[Abridged] Electromagnetic emission can be produced as a precursor to the merger, as a prompt emission during the collapse of a NS and at the spin-down stage of the resulting BH. We demonstrate that the time evolution of the axisymmetric force-free magnetic fields can be expressed in terms of the hyperbolic Grad-Shafranov equation. We find exact non-linear time-dependent split-monopole structure of magnetosphere driven by spinning and collapsing NS in Schwarzschild geometry. Based on this solution, we argue that the collapse of a NS into the BH happens smoothly, without natural formation of current sheets or other dissipative structures on the open field lines and, thus, does not allow the magnetic field to become disconnected from the star and escape to infinity. Thus, as long as an isolated Kerr BH can produce plasma and currents, it does not lose its open magnetic field lines, its magnetospheric structure evolved towards a split monopole and the BH spins down electromagnetically. The "no hair theorem", which assumes that the outside medium is a vacuum, is not applicable in this case: highly conducting plasma introduces a topological constraint forbidding the disconnection of the magnetic field lines from the BH. Eventually, a single random large scale spontaneous reconnection event will lead to magnetic field release, shutting down the electromagnetic BH engine forever. We also discuss the nature of short Gamma Ray Bursts and suggest that the similarity of the early afterglows properties of long and short GRBs can be related to the fact that in both cases a spinning BH can retains magnetic field for sufficiently long time to extract a large fraction of its rotation energy and produce high energy emission via the internal dissipation in the wind.

Maxim Lyutikov

2011-04-06T23:59:59.000Z

422

Methods, computer readable media, and graphical user interfaces for analysis of frequency selective surfaces  

DOE Patents [OSTI]

A frequency selective surface (FSS) and associated methods for modeling, analyzing and designing the FSS are disclosed. The FSS includes a pattern of conductive material formed on a substrate to form an array of resonance elements. At least one aspect of the frequency selective surface is determined by defining a frequency range including multiple frequency values, determining a frequency dependent permittivity across the frequency range for the substrate, determining a frequency dependent conductivity across the frequency range for the conductive material, and analyzing the frequency selective surface using a method of moments analysis at each of the multiple frequency values for an incident electromagnetic energy impinging on the frequency selective surface. The frequency dependent permittivity and the frequency dependent conductivity are included in the method of moments analysis.

Kotter, Dale K. (Shelley, ID) [Shelley, ID; Rohrbaugh, David T. (Idaho Falls, ID) [Idaho Falls, ID

2010-09-07T23:59:59.000Z

423

Spectrum of the volume integral operator of electromagnetic scattering  

E-Print Network [OSTI]

Spectrum of the volume integral operator of the three-dimensional electromagnetic scattering is analyzed. The operator has both continuous essential spectrum, which dominates at lower frequencies, and discrete eigenvalues, which spread out at higher ones. The explicit expression of the operator's symbol provides exact outline of the essential spectrum for any inhomogeneous anisotropic scatterer with Holder continuous constitutive parameters. Geometrical bounds on the location of discrete eigenvalues are derived for various physical scenarios. Numerical experiments demonstrate good agreement between the predicted spectrum of the operator and the eigenvalues of its discretized version.

Neil V. Budko; Alexander B. Samokhin

2005-05-04T23:59:59.000Z

424

Terahertz electromagnetic wave generation and amplification by an electron beam in the elliptical plasma waveguides with dielectric rod  

SciTech Connect (OSTI)

The propagation of electromagnetic waves in an elliptical plasma waveguide including strongly magnetized plasma column and a dielectric rod is investigated. The dispersion relation of guided hybrid electromagnetic waves is obtained. Excitation of the waves by a thin annular relativistic elliptical electron beam will be studied. The time growth rate of electromagnetic waves is obtained. The effects of relative permittivity constant of dielectric rod, radius of dielectric rod, accelerating voltage, and current density of the annular elliptical beam on the growth rate and the frequency spectra are numerically presented.

Rahmani, Z., E-mail: z.rahmani@kashanu.ac.ir; Jazi, B. [Department of Laser and Photonics, Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Heidari-Semiromi, E. [Department of Condense Matter, Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of)

2014-09-15T23:59:59.000Z

425

Magnetoelectric-field helicities and reactive power flows  

E-Print Network [OSTI]

The dual symmetry between the electric and magnetic fields underlies Maxwell's electrodynamics. Due to this symmetry one can describe topological properties of an electromagnetic field in free space and obtain the conservation law of optical (electromagnetic) helicity. What kind of the field helicity one can expect to see when the electromagnetic-field symmetry is broken? The near fields originated from small ferrite particles with magnetic dipolar mode (MDM) oscillations are the fields with the electric and magnetic components, but with broken dual (electric-magnetic) symmetry. These fields, called magnetoelectric (ME) fields, have topological properties different from such properties of electromagnetic fields. The helicity states of ME fields are topologically protected quantum like states. In this paper, we study the helicity properties of ME fields. We analyze conservation laws of the ME-field helicity and show that the helicity density is related to an imaginary part of the complex power flow density. We...

Kamenetskii, E O; Shavit, R

2015-01-01T23:59:59.000Z

426

Three Dimensional Controlled-source Electromagnetic Edge-based Finite Element Modeling of Conductive and Permeable Heterogeneities  

E-Print Network [OSTI]

ordnance, is often highly conductive and magnetically permeable. Interpretation of the CSEM response in the presence of cultural noise requires an understanding of electromagnetic field diffusion and the effects of anomalous highly conductive and permeable...

Mukherjee, Souvik

2010-10-12T23:59:59.000Z

427

High-frequency surface wave pumped He-Ne laser  

SciTech Connect (OSTI)

A new electrodeless He-Ne laser using a plasma produced by an electromagnetic surface wave as the active medium is described. Gain measurements are reported as a function of the pump wave frequency from 200 to 915 MHz. The dependence of laser performance on the gas mixture and pressure is also presented.

Moutoulas, C.; Moisan, M.; Bertrand, L.; Hubert, J.; Lachambre, J.L.; Ricard, A.

1985-02-15T23:59:59.000Z

428

LowFrequency Solar Radio Bursts from Green Bank  

E-Print Network [OSTI]

waves at the plasma frequency that are converted into fundamental and har- monic electromagnetic waves of emission during the decline of the soft X­rays. The Type III bursts are attributed to beams of keV­energy (UT) 20040716 GBSRBS GOES FIGURE 4: Short­wave fadeout followed by a Type II burst. In this figure

White, Stephen

429

Electromagnetic confinement for vertical casting or containing molten metal  

DOE Patents [OSTI]

An apparatus and method adapted to confine a molten metal to a region by means of an alternating electromagnetic field. As adapted for use in the present invention, the alternating electromagnetic field given by B.sub.y =(2.mu..sub.o .rho.gy).sup.1/2 (where B.sub.y is the vertical component of the magnetic field generated by the magnet at the boundary of the region; y is the distance measured downward form the top of the region, .rho. is the metal density, g is the acceleration of gravity and .mu..sub.o is the permeability of free space) induces eddy currents in the molten metal which interact with the magnetic field to retain the molten metal with a vertical boudnary. As applied to an apparatus for the continuous casting of metal sheets or rods, metal in liquid form can be continuously introduced into the region defined by the magnetic field, solidified and conveyed away from the magnetic field in solid form in a continuous process.

Lari, Robert J. (Aurora, IL); Praeg, Walter F. (Palos Park, IL); Turner, Larry R. (Naperville, IL)

1991-01-01T23:59:59.000Z

430

Dr. S. Cruz-Pol, INEL 4152-Electromagnetics Electrical Engineering, UPRM  

E-Print Network [OSTI]

was born! · This is the principle of motors, hydro-electric generators and transformers operation. Cruz/m] · B = magnetic field density, [Teslas] · J = current density [A/m2] Cruz-Pol, Electromagnetics UPRM a conduc4ng loop is moving inside a magnet (sta4c B field, in Teslas), the force

Cruz-Pol, Sandra L.

431

Electromagnetic interactions at RHIC and LHC  

E-Print Network [OSTI]

At LHC energies the Lorentz factor will be 3400 for the Pb + Pb collisions and the electromagnetic interactions will play important roles. Cross sections for the electromagnetic particle productions are very large and can not be ignored for the lifetimes of the beams and background. In this article, we are going to study some of the electromagnetic processes at RHIC and LHC and show the cross section calculations of the electron-positron pair production with the giant dipole resonance of the ions.

M. C. Guclu

2008-11-15T23:59:59.000Z

432

Discrimination of partial discharge electromagnetic signal in SF{sub 6} gas from external noises using phase gate control method  

SciTech Connect (OSTI)

The authors proposed phase gate control method for distinguishing frequency spectrum of electromagnetic wave caused by partial discharge (PD) in SF{sub 6} gas from external noises. They investigated the dependence of the polarity and phase angle of ac voltage on the electromagnetic wave spectrum. They derived the frequency region where PD spectrum caused by SF{sub 6} gas can be detected under noisy conditions. The authors also related quantitatively the gain of electromagnetic wave spectrum to the maximum PD charge simultaneously occurring in both SF{sub 6} gas and air. On the basis of these results, they determined the minimum detectable PD level in SF{sub 6} gas under noisy conditions as a function of measuring frequency.

Hikita, M.; Hoshino, T.; Kato, T.; Hayakawa, N.; Okubo, H. [Nagoya Univ. (Japan); Ueda, T. [Chubu Electric Power Co., Inc., Nagoya (Japan)

1996-12-31T23:59:59.000Z

433

The Speed of Light as a Dilaton Field  

E-Print Network [OSTI]

Through dimensional analysis, eliminating the physical time, we identify the speed of light as a dilaton field. This leads to a restmass zero, spin zero gauge field which we call the speedon field. The complete Lagrangian for gravitational, electromagnetic and speedon field interactions with a charged scalar field, representing matter, is given. We then find solutions for the gravitational-electromagnetic-speedon field equations. This then gives an expression for the speed of light.

Walter Wyss

1997-12-09T23:59:59.000Z

434

Cellular Manipulation and Control by Electromagnetism | Argonne...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

phenomenon for sensors; however, one may also use intense electromagnetic radiation, such as pulsed power, plasmas, or lasers, to induce changes in cellular...

435

6.630 Electromagnetic Theory, Fall 2002  

E-Print Network [OSTI]

6.630 is an introductory subject on electromagnetics, emphasizing fundamental concepts and applications of Maxwell equations. Topics covered include: polarization, dipole antennas, wireless communications, forces and energy, ...

Kong, Jin Au, 1942-

436

22.105 Electromagnetic Interactions, Fall 1998  

E-Print Network [OSTI]

Principles and applications of electromagnetism, starting from Maxwell's equations, with emphasis on phenomena important to nuclear engineering and radiation sciences. Solution methods for electrostatic and magnetostatic ...

Hutchinson, I. H. (Ian H.)

437

Detecting excess ionizing radiation by electromagnetic breakdown of air  

SciTech Connect (OSTI)

A scheme is proposed for detecting a concealed source of ionizing radiation by observing the occurrence of breakdown in atmospheric air by an electromagnetic wave whose electric field surpasses the breakdown field in a limited volume. The volume is chosen to be smaller than the reciprocal of the naturally occurring concentration of free electrons. The pulse duration of the electromagnetic wave must exceed the avalanche breakdown time (10-200 ns) and could profitably be as long as the statistical lag time in ambient air (typically, microseconds). Candidate pulsed electromagnetic sources over a wavelength range, 3 mm>{lambda}>10.6 {mu}m, are evaluated. Suitable candidate sources are found to be a 670 GHz gyrotron oscillator with 200 kW, 10 {mu}s output pulses and a Transversely Excited Atmospheric-Pressure (TEA) CO{sub 2} laser with 30 MW, 100 ns output pulses. A system based on 670 GHz gyrotron would have superior sensitivity. A system based on the TEA CO{sub 2} laser could have a longer range >100 m.

Granatstein, Victor L.; Nusinovich, Gregory S. [Center for Applied Electromagnetics, Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States)

2010-09-15T23:59:59.000Z

438

Electromagnetic effects on transportation systems  

SciTech Connect (OSTI)

Electronic and electrical system protection design can be used to eliminate deleterious effects from lightning, electromagnetic interference, and electrostatic discharges. Evaluation of conventional lightning protection systems using advanced computational modeling in conjunction with rocket-triggered lightning tests suggests that currently used lightning protection system design rules are inadequate and that significant improvements in best practices used for electronic and electrical system protection designs are possible. A case study of lightning induced upset and failure of a railway signal and control system is sketched.

Morris, M.E.; Dinallo, M.A.

1996-05-01T23:59:59.000Z

439

Magneto-optical resonance of electromagnetically induced absorption with high contrast and narrow width in a vapour cell with buffer gas  

E-Print Network [OSTI]

The method for observing the high-contrast and narrow-width resonances of electromagnetically induced absorption (EIA) in the Hanle configuration under counterpropagating light waves is proposed. We theoretically analyze the absorption of a probe light wave in presence of counterpropagating one with the same frequency as the function of a static magnetic field applied along the vectors of light waves, propagating in a vapour cell. Here, as an example, we study a "dark" type of atomic dipole transition Fg=1-->Fe=1 in D1 line of 87Rb, where usually the electromagnetically induced transparency (EIT) can be observed. To obtain the EIA signal one should proper chose the polarizations of light waves and intensities. In contrast of regular schemes for observing EIA signals (in a single travelling light wave in the Hanle configuration or in a bichromatic light field consisted of two travelling waves), the proposed scheme allows one to use buffer gas to significantly enhance properties of the resonance. Also the dramatic influence of atomic transition openness on contrast of the resonance is revealed, that gives great advantage in comparison with cyclic atomic transitions. The obtained results can be interesting in high-resolution spectroscopy, nonlinear and magneto-optics.

D. V. Brazhnikov; A. V. Taichenachev; V. I. Yudin

2014-08-11T23:59:59.000Z

440

Modulational instability of electromagnetic waves in a collisional quantum magnetoplasma  

SciTech Connect (OSTI)

The modulational instability of right-hand circularly polarized electromagnetic electron cyclotron (CPEM-EC) wave in a magnetized quantum plasma is studied taking into account the collisional effects. Employing quantum hydrodynamic and nonlinear Schrödinger equations, the dispersion relation of modulated CPEM-EC wave in a collisional plasma has been derived. It is found that this wave is unstable in such a plasma system and the growth rate of the associated instability depends on various parameters such as electron Fermi temperature, plasma number density, collision frequency, and modulation wavenumber. It is shown that while the increase of collision frequency leads to increase of the growth rate of instability, especially at large wavenumber limit, the increase of plasma number density results in more stable modulated CPEM-EC wave. It is also found that in contrast to collisionless plasma in which modulational instability is restricted to small wavenumbers, in collisional plasma, the interval of instability occurrence can be extended to a large domain.

Niknam, A. R., E-mail: a-niknam@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of); Rastbood, E.; Bafandeh, F.; Khorashadizadeh, S. M., E-mail: smkhorashadi@birjand.ac.ir [Physics Department of Birjand University, Birjand (Iran, Islamic Republic of)

2014-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Electromagnetic wave propagation in a random distribution of C{sub 60} molecules  

SciTech Connect (OSTI)

Propagation of electromagnetic waves in a random distribution of C{sub 60} molecules are investigated, within the framework of the classical electrodynamics. Electronic excitations over the each C{sub 60} molecule surface are modeled by a spherical layer of electron gas represented by two interacting fluids, which takes into account the different nature of the ? and ? electrons. It is found that the present medium supports four modes of electromagnetic waves, where they can be divided into two groups: one group with shorter wavelength than the light waves of the same frequency and the other with longer wavelength than the free-space radiation.

Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Engineering Physics, Kermanshah University of Technology, Kermanshah, Iran and Department of Nano Sciences, Institute for Studies in Theoretical Physics and Mathematics (IPM), Tehran (Iran, Islamic Republic of)

2014-10-15T23:59:59.000Z

442

Mechanisms of electromagnetic interference between electrical networks and neighboring metallic utilities  

SciTech Connect (OSTI)

This paper examines the mechanisms of electromagnetic interference between a power line and a neighboring pipeline. An electromagnetic field theory approach is used to carry out the study. First, the field theory approach is used to model the complete conductor network under consideration as is. The inductive, capacitive and conductive interference effects between all the elements in the network are simultaneously taken into account in one single step. The computed results are then used to develop a network model whereby the inductive, capacitive and conductive interference effects can be separated. This approach allows one to better understand the effects of each individual component and compare the field-theory (inductive) based results with those obtained from a circuit model approach. The effects of a typical mitigation system on the interference levels are also studied. The results presented in this paper clearly illustrate the mechanisms of electromagnetic interference and mitigation between electrical networks and neighboring metallic utilities.

Dawalibi, F.P.; Ma, J.; Li, Y. [Safe Engineering Services and Technologies Ltd., Montreal, Quebec (Canada)

1999-11-01T23:59:59.000Z

443

Trapping of electrons in troughs of self generated electromagnetic standing waves in a bounded plasma column  

SciTech Connect (OSTI)

Observations and measurements are reported on electron trapping in troughs of self-generated electromagnetic standing waves in a bounded plasma column confined in a minimum-B field. The boundaries are smaller than the free space wavelength of the waves. Earlier work of researchers primarily focused upon electron localization effects induced by purely electrostatic perturbation. We demonstrate the possibility in the presence of electromagnetic standing waves generated in the bounded plasma column. The electron trapping is verified with electrostatic measurements of the plasma floating potential, electromagnetic measurements of the wave field profile, and optical intensity measurements of Argon ionic line at 488?nm. The experimental results show a reasonably good agreement with predictions of a Monte Carlo simulation code that takes into account all kinematical and dynamical effects in the plasma in the presence of bounded waves and external fields.

Bhattacharjee, Sudeep; Sahu, Debaprasad; Pandey, Shail; Chatterjee, Sanghomitro [Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016 (India)] [Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Dey, Indranuj [Department of Advanced Energy Engineering Science, Kyushu University, Kasuga Kouen 6-1, Kasuga City 816-8580 (Japan)] [Department of Advanced Energy Engineering Science, Kyushu University, Kasuga Kouen 6-1, Kasuga City 816-8580 (Japan); Roy Chowdhury, Krishanu [Max Planck Institute for the Physics of Complex System, Dresden 01187 (Germany)] [Max Planck Institute for the Physics of Complex System, Dresden 01187 (Germany)

2014-01-15T23:59:59.000Z

444

Exact microscopic theory of electromagnetic heat transfer between a dielectric sphere and plate  

E-Print Network [OSTI]

Near-field electromagnetic heat transfer holds great potential for the advancement of nanotechnology. Whereas far-field electromagnetic heat transfer is constrained by Planck's blackbody limit, the increased density of states in the near-field enhances heat transfer rates by orders of magnitude relative to the conventional limit. Such enhancement opens new possibilities in numerous applications, including thermal-photo-voltaics, nano-patterning, and imaging. The advancement in this area, however, has been hampered by the lack of rigorous theoretical treatment, especially for geometries that are of direct experimental relevance. Here we introduce an efficient computational strategy, and present the first rigorous calculation of electromagnetic heat transfer in a sphere-plate geometry, the only geometry where transfer rate beyond blackbody limit has been quantitatively probed at room temperature. Our approach results in a definitive picture unifying various approximations previously used to treat this problem, ...

Otey, Clayton

2011-01-01T23:59:59.000Z

445

Exact microscopic theory of electromagnetic heat transfer between a dielectric sphere and plate  

E-Print Network [OSTI]

Near-field electromagnetic heat transfer holds great potential for the advancement of nanotechnology. Whereas far-field electromagnetic heat transfer is constrained by Planck's blackbody limit, the increased density of states in the near-field enhances heat transfer rates by orders of magnitude relative to the conventional limit. Such enhancement opens new possibilities in numerous applications, including thermal-photo-voltaics, nano-patterning, and imaging. The advancement in this area, however, has been hampered by the lack of rigorous theoretical treatment, especially for geometries that are of direct experimental relevance. Here we introduce an efficient computational strategy, and present the first rigorous calculation of electromagnetic heat transfer in a sphere-plate geometry, the only geometry where transfer rate beyond blackbody limit has been quantitatively probed at room temperature. Our approach results in a definitive picture unifying various approximations previously used to treat this problem, and provides new physical insights for designing experiments aiming to explore enhanced thermal transfer.

Clayton Otey; Shanhui Fan

2011-10-10T23:59:59.000Z

446

Electromagnetic probes of the QGP  

E-Print Network [OSTI]

We investigate the properties of the QCD matter across the deconfinement phase transition in the scope of the parton-hadron string dynamics (PHSD) transport approach. We present here in particular the results on the electromagnetic radiation, i.e. photon and dilepton production, in relativistic heavy-ion collisions. By comparing our calculations for the heavy-ion collisions to the available data, we determine the relative importance of the various production sources and address the possible origin of the observed strong elliptic flow $v_2$ of direct photons. We argue that the different centrality dependence of the hadronic and partonic sources for direct photon production in nucleus-nucleus collisions can be employed to shed some more light on the origin of the photon $v_2$ "puzzle". While the dilepton spectra at low invariant mass show in-medium effects like an enhancement from multiple baryonic resonance formation or a collisional broadening of the vector meson spectral functions, the dilepton yield at high invariant masses (above 1.1 GeV) is dominated by QGP contributions for central heavy-ion collisions at ultra-relativistic energies. This allows to have an independent view on the parton dynamics via their electromagnetic massive radiation.

E. L. Bratkovskaya; O. Linnyk; W. Cassing

2014-09-15T23:59:59.000Z

447

Compact orthogonal NMR field sensor  

DOE Patents [OSTI]

A Compact Orthogonal Field Sensor for emitting two orthogonal electro-magnetic fields in a common space. More particularly, a replacement inductor for existing NMR (Nuclear Magnetic Resonance) sensors to allow for NMR imaging. The Compact Orthogonal Field Sensor has a conductive coil and a central conductor electrically connected in series. The central conductor is at least partially surrounded by the coil. The coil and central conductor are electrically or electro-magnetically connected to a device having a means for producing or inducing a current through the coil and central conductor. The Compact Orthogonal Field Sensor can be used in NMR imaging applications to determine the position and the associated NMR spectrum of a sample within the electro-magnetic field of the central conductor.

Gerald, II, Rex E. (Brookfield, IL); Rathke, Jerome W. (Homer Glen, IL)

2009-02-03T23:59:59.000Z

448

Electromagnetically Restrained Lithium Blanket APEX Interim Report November, 1999  

E-Print Network [OSTI]

to avoid corrosion or fire. Lithium's high electrical conductivity may possibly permit efficient, compactElectromagnetically Restrained Lithium Blanket APEX Interim Report November, 1999 6-1 CHAPTER 6: ELECTROMAGNETICALLY RESTRAINED LITHIUM BLANKET Contributors Robert Woolley #12;Electromagnetically Restrained Lithium

California at Los Angeles, University of

449

Electromagnetic Inverse Problems Involving Distributions of Dielectric Mechanisms and Parameters  

E-Print Network [OSTI]

Electromagnetic Inverse Problems Involving Distributions of Dielectric Mechanisms and Parameters H University, Raleigh, NC 27695-8205 August 17, 2005 Abstract We consider electromagnetic interrogation, uniform, log-normal, and log-Bi-Gaussian distributions. Keywords: Electromagnetic interrogation

450

Regularity and approximation of systems arising in electromagnetic interrogation of  

E-Print Network [OSTI]

Regularity and approximation of systems arising in electromagnetic interrogation of dielectric describes the electromagnetic interrogation of dielectric materials. We address the well describing the electromagnetic in- terrogation of dielectric materials. Let E and H be the intensities

451

Electromagnetic corrections to light hadron masses  

E-Print Network [OSTI]

At the precision reached in current lattice QCD calculations, electromagnetic effects are becoming numerically relevant. We will present preliminary results for electromagnetic corrections to light hadron masses, based on simulations in which a $\\mathrm{U}(1)$ degree of freedom is superimposed on $N_f=2+1$ QCD configurations from the BMW collaboration.

A. Portelli; S. Dürr; Z. Fodor; J. Frison; C. Hoelbling; S. D. Katz; S. Krieg; T. Kurth; L. Lellouch; T. Lippert; K. K. Szabó; A. Ramos

2011-01-12T23:59:59.000Z

452

Optimization Material Distribution methodology: Some electromagnetic examples  

E-Print Network [OSTI]

730 1 Optimization Material Distribution methodology: Some electromagnetic examples P. Boissoles, H. Ben Ahmed, M. Pierre, B. Multon Abstract--In this paper, a new approach towards Optimization Material to be highly adaptive to various kinds of electromagnetic actuator optimization approaches. Several optimal

Paris-Sud XI, Université de

453

applied computational electromagnetics: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electromagnetics Geosciences Websites Summary: Max Optics, Inc. 12;MadMax Optics 2 Stealth Electromagnetic interference Antennas on complex platformsFMM Code...

454

Electromagnetic Interference (EMI) Shielding of Single-Walled Carbon  

E-Print Network [OSTI]

Electromagnetic Interference (EMI) Shielding of Single-Walled Carbon Nanotube Epoxy Composites Ning (SWNT)-polymer composites have been fabricated to evaluate the electromagnetic interference (EMI

Gao, Hongjun

455

Electromagnetic Interference in Wireless Communications: Behavioral-Level Simulation  

E-Print Network [OSTI]

Electromagnetic Interference in Wireless Communications: Behavioral-Level Simulation Approach in electromagnetic interference (EMI) modeling and simulation for modern and future wireless communication systems

Loyka, Sergey

456

HOT ELECTROMAGNETIC OUTFLOWS. II. JET BREAKOUT  

SciTech Connect (OSTI)

We consider the interaction between radiation, matter, and a magnetic field in a compact, relativistic jet. The entrained matter accelerates outward as the jet breaks out of a star or other confining medium. In some circumstances, such as gamma-ray bursts (GRBs), the magnetization of the jet is greatly reduced by an advected radiation field while the jet is optically thick to scattering. Where magnetic flux surfaces diverge rapidly, a strong outward Lorentz force develops and radiation and matter begin to decouple. The increase in magnetization is coupled to a rapid growth in Lorentz factor. We take two approaches to this problem. The first examines the flow outside the fast magnetosonic critical surface, and calculates the flow speed and the angular distribution of the radiation field over a range of scattering depths. The second considers the flow structure on both sides of the critical surface in the optically thin regime, using a relaxation method. In both approaches, we find how the terminal Lorentz factor and radial profile of the outflow depend on the radiation intensity and optical depth at breakout. The effect of bulk Compton scattering on the radiation spectrum is calculated by a Monte Carlo method, while neglecting the effects of internal dissipation. The peak of the scattered spectrum sits near the seed peak if radiation pressure dominates the acceleration, but is pushed to a higher frequency if the Lorentz force dominates. The unscattered seed radiation can form a distinct, low-frequency component of the spectrum, especially if the magnetic Poynting flux dominates.

Russo, Matthew [Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7 (Canada); Thompson, Christopher [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)

2013-08-20T23:59:59.000Z

457

Electromagnetic Energy, Absorption, and Casimir Forces. I. Uniform Dielectric Media in Thermal Equilibrium  

E-Print Network [OSTI]

The derivation of Casimir forces between dielectrics can be simplified by ignoring absorption, calculating energy changes due to displacements of the dielectrics, and only then admitting absorption by allowing permittivities to be complex. As a first step towards a better understanding of this situation we consider in this paper the model of a dielectric as a collection of oscillators, each of which is coupled to a reservoir giving rise to damping and Langevin forces on the oscillators and a noise polarization acting as a source of a fluctuating electromagnetic (EM) field in the dielectric. The model leads naturally to expressions for the quantized EM fields that are consistent with those obtained by different approaches, and also results in a fluctuation-dissipation relation between the noise polarization and the imaginary part of the permittivity; comparison with the Rytov fluctuation-dissipation relation employed in the well-known Lifshitz theory for the van der Waals (or Casimir) force shows that the Lifshitz theory is actually a classical stochastic electrodynamical theory. The approximate classical expression for the energy density in a band of frequencies at which absorption in a dielectric is negligible is shown to be exact as a spectral thermal equilibrium expectation value in the quantum-electrodynamical theory. Our main result is the derivation of an expression for the QED energy density of a uniform dispersive, absorbing media in thermal equilibrium. The spectral density of the energy is found to have the same form with or without absorption. We also show how the fluctuation-dissipation theorem ensures a detailed balance of energy exchange between the (absorbing) medium, the reservoir and the EM field in thermal equilibrium.

F. S. S. Rosa; D. A. R. Dalvit; P. W. Milonni

2009-11-14T23:59:59.000Z

458

The dispersion relation and excitation of transverse magnetic mode electromagnetic waves in rippled-wall waveguide with a plasma rod and an annular dielectric  

SciTech Connect (OSTI)

By using the linear field theory, the dispersion relation of electromagnetic waves in a rippled-wall waveguide with a plasma rod and an annular dielectric is obtained. In addition, by injecting a finite thick annular intense relativistic electron beam in this waveguide, the excitation of these waves is investigated. Furthermore, the effects of the radius of the plasma rod, the radius of the dielectric, the corrugation amplitude, and period on the frequency spectrum are investigated. Besides, the time growth rate of excitation of these waves by an annular relativistic electron beam is studied. Finally, to demonstrate the advantages of this rippled-wall waveguide, the dispersion relation and the growth rate of three simplified cases are investigated.

Nejati, M. [Physics Department, Shahid Beheshti University, G. C. Evin, Tehran (Iran, Islamic Republic of); Shokri, B. [Physics Department and Laser-Plasma Research Institute, Shahid Beheshti University, G. C. Evin, Tehran (Iran, Islamic Republic of)

2012-01-15T23:59:59.000Z

459

Horizontal electromagnetic casting of thin metal sheets  

DOE Patents [OSTI]

Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

Hull, John R. (Hinsdale, IL); Lari, Robert J. (Aurora, IL); Praeg, Walter F. (Palos Park, IL); Turner, Larry R. (Naperville, IL)

1987-01-01T23:59:59.000Z

460

Horizontal electromagnetic casting of thin metal sheets  

DOE Patents [OSTI]

Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

Hull, John R. (Hinsdale, IL); Lari, Robert J. (Aurora, IL); Praeg, Walter F. (Palos Park, IL); Turner, Larry R. (Naperville, IL)

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency electromagnetic fields" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY, VOL. 49, NO. 3, AUGUST 2007 661 Novel Planar Electromagnetic Bandgap Structures  

E-Print Network [OSTI]

. A novel concept of using these EBG structures for electromagnetic interference reduction is also, the power/ground noise creates significant and new challenges for electromagnetic interference

Ramahi, Omar

462

Counting energy packets in the electromagnetic wave  

E-Print Network [OSTI]

We discuss the concept of energy packets in respect to the energy transported by electromagnetic waves and we demonstrate that this physical quantity can be used in physical problems involving relativistic effects. This refined concept provides results compatible to those obtained by simpler definition of energy density when relativistic effects apply to the free electromagnetic waves. We found this concept further compatible to quantum theory perceptions and we show how it could be used to conciliate between different physical approaches including the classical electromagnetic wave theory, the special relativity and the quantum theories.

Stefan Popescu; Bernhard Rothenstein

2007-05-18T23:59:59.000Z

463

Magnetically coupled electromagnetically induced transparency analogy of dielectric metamaterial  

SciTech Connect (OSTI)

In this manuscript, we experimentally demonstrate magnetically coupled electromagnetically induced transparency (EIT) analogy effect inside dielectric metamaterial. In contrast to previous studies employed different metallic topological microstructures to introduce dissipation loss change, barium strontium titanate, and calcium titanate (CaTiO{sub 3}) are chosen as the bright and dark EIT resonators, respectively, due to their different intrinsic dielectric loss. Under incident magnetic field excitation, dielectric metamaterial exhibits an EIT-type transparency window around 8.9?GHz, which is accompanied by abrupt change of transmission phase. Numerical calculations show good agreement with experiment spectra and reveal remarkably increased group index, indicating potential application in slow light.

Zhang, Fuli, E-mail: fuli.zhang@nwpu.edu.cn; He, Xuan [Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education and Department of Applied Physics, School of Science, Northwestern Polytechnical University, Xi'an 710072 (China); Zhao, Qian [State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Lan, Chuwen; Zhou, Ji [State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Zhang, Weihong, E-mail: zhangwh@nwpu.edu.cn; Qiu, Kepeng [School of Mechanical Engineering, P.O. Box 552, Northwestern Polytechnical University, Xi'an 710072 (China)

2014-03-31T23:59:59.000Z

464

Dr. S. Cruz-Pol, INEL 4151-Electromagnetics I  

E-Print Network [OSTI]

! dt d NVemf -= -= sL dSB t dlE Electromagnetics was born! � This is the principle of motors = magnetic field density, [Teslas] mH mF HB ED o o /104 36 10 /1085.8 7 9 12 - - - �= =�= = = µ µ #12;Dr://micro.magnet.fsu.edu/electromag/java/generator/dc.html BlIF BuQF �= �= Encarta® Who was NikolaTesla? �Find out what inventions he made �His relation

Cruz-Pol, Sandra L.

465

Nucleon electromagnetic form factors from twisted mass lattice QCD  

E-Print Network [OSTI]

Results on the electromagnetic form factors of the nucleon using twisted mass fermion configurations are presented. These include a gauge field ensemble simulated with two degenerate light quarks yielding a pion mass of around 130 MeV, as well as two ensembles that include strange and charm quarks in the sea yielding pion masses of 210 MeV and 373 MeV. Details of the methods used and systematic errors are discussed, such as noise reduction techniques and the effect of excited states contamination.

Abdou Abdel-Rehim; Constantia Alexandrou; Martha Constantinou; Kyriakos Hadjiyiannakou; Karl Jansen; Giannis Koutsou

2015-01-07T23:59:59.000Z

466

Nucleon electromagnetic form factors from twisted mass lattice QCD  

E-Print Network [OSTI]

Results on the electromagnetic form factors of the nucleon using twisted mass fermion configurations are presented. These include a gauge field ensemble simulated with two degenerate light quarks yielding a pion mass of around 130 MeV, as well as two ensembles that include strange and charm quarks in the sea yielding pion masses of 210 MeV and 373 MeV. Details of the methods used and systematic errors are discussed, such as noise reduction techniques and the effect of excited states contamination.

Abdel-Rehim, Abdou; Constantinou, Martha; Hadjiyiannakou, Kyriakos; Jansen, Karl; Koutsou, Giannis

2015-01-01T23:59:59.000Z

467

Electromagnetic Properties for Arbitrary Spin Particles: Part 1 $-$ Electromagnetic Current and Multipole Decomposition  

E-Print Network [OSTI]

In a set of two papers, we propose to study an old-standing problem, namely the electromagnetic interaction for particles of arbitrary spin. Based on the assumption that light-cone helicity at tree level and $Q^2=0$ should be conserved non-trivially by the electromagnetic interaction, we are able to derive \\emph{all} the natural electromagnetic moments for a pointlike particle of \\emph{any} spin. In this first paper, we propose a transparent decomposition of the electromagnetic current in terms of covariant vertex functions. We also define in a general way the electromagnetic multipole form factors, and show their relation with the electromagnetic moments. Finally, by considering the Breit frame, we relate the covariant vertex functions to multipole form factors.

Cédric Lorcé

2009-01-27T23:59:59.000Z

468

Gravitational Bending of Light with Frequency Shifts  

E-Print Network [OSTI]

Non-static gravitational fields generally introduce frequency shifts when bending light. In this paper, I discuss the frequency shifts induced in the bending of light by moving masses. As examples, I treat the recently discovered high-velocity pulsar PSR 2224+65 and a typical Einstein ring.

P. D. Morley

1993-11-15T23:59:59.000Z

469

Dynamic programming applied to electromagnetic satellite actuation  

E-Print Network [OSTI]

Electromagnetic formation flight (EMFF) is an enabling technology for a number of space mission architectures. While much work has been done for EMFF control for large separation distances, little work has been done for ...

Eslinger, Gregory John

2013-01-01T23:59:59.000Z

470

Advances in non-planar electromagnetic prototyping  

E-Print Network [OSTI]

The advent of metamaterials has introduced new ways to manipulate how electromagnetic waves reflect, refract and radiate in systems where the range of available material properties now includes negative permittivity, ...

Ehrenberg, Isaac M

2013-01-01T23:59:59.000Z

471

Electrical wire insulation and electromagnetic coil  

DOE Patents [OSTI]

An electromagnetic coil for high temperature and high radiation application in which glass is used to insulate the electrical wire. A process for applying the insulation to the wire is disclosed which results in improved insulation properties.

Bich, George J. (Penn Hills, PA); Gupta, Tapan K. (Monroeville, PA)

1984-01-01T23:59:59.000Z

472

Characterization of electromagnetic transients in power substations  

E-Print Network [OSTI]

CHARACTERIZATION OF ELECTROMAGNETIC TRANSIENTS IN POWER SUBSTATIONS A Thesis by WILLIAM CHESTER CiOERS, JR. Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE December 1980 Major Subject: Electrical Engineering CHARACTERIZATION OF ELECTROMAGNETIC TRANSIENTS IN POWER SUBSTATIONS A Thesis by WILLIAM CHESTER GOERS, JR. Approved as to style and content by: Dr. B. Don Russell (Chairman of Committee...

Goers, William Chester

1980-01-01T23:59:59.000Z