Method for imaging with low frequency electromagnetic fields
Lee, Ki H. (Lafayette, CA); Xie, Gan Q. (Berkeley, CA)
1994-01-01T23:59:59.000Z
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.
Method for imaging with low frequency electromagnetic fields
Lee, K.H.; Xie, G.Q.
1994-12-13T23:59:59.000Z
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.
Motai, Yuichi
. This electronic system can be used to monitor VLF electromagnetic radiation in residential and occupational-Low-Frequency Electromagnetic Field Detector With Data Acquisition Saba A. Hanna, Member, IEEE, Yuichi Motai, Member, IEEE-made VLF electromagnetic fields are stronger and have been suspected of causing negative health effects
Enhancement of Kv1.3 Potassium Conductance by Extremely Low Frequency Electromagnetic Field
Claudia Cecchetto; Marta Maschietto; Pasquale Boccaccio; Stefano Vassanelli
2015-08-25T23:59:59.000Z
Theoretical and experimental evidences support the hypothesis that extremely low-frequency electromagnetic fields can affect voltage-gated channels. Little is known, however, about their effect on potassium channels. Kv1.3, a member of the voltage-gated potassium channels family originally discovered in the brain, is a key player in important biological processes including antigen-dependent activation of T-cells during the immune response. We report that Kv1.3 expressed in CHO-K1 cells can be modulated in cell subpopulations by extremely low frequency and relatively low intensity electromagnetic fields. In particular, we observed that field exposure can cause an enhancement of Kv1.3 potassium conductance and that the effect lasts for several minutes after field removal. The results contribute to put immune and nervous system responses to extremely low-frequency electromagnetic fields into a new perspective, with Kv1.3 playing a pivotal molecular role. Keywords: immunotherapy, immunomodulation, potassium channels, gating, electromagnetic fields
Enhancement of Kv1.3 Potassium Conductance by Extremely Low Frequency Electromagnetic Field
Cecchetto, Claudia; Boccaccio, Pasquale; Vassanelli, Stefano
2015-01-01T23:59:59.000Z
Theoretical and experimental evidences support the hypothesis that extremely low-frequency electromagnetic fields can affect voltage-gated channels. Little is known, however, about their effect on potassium channels. Kv1.3, a member of the voltage-gated potassium channels family originally discovered in the brain, is a key player in important biological processes including antigen-dependent activation of T-cells during the immune response. We report that Kv1.3 expressed in CHO-K1 cells can be modulated in cell subpopulations by extremely low frequency and relatively low intensity electromagnetic fields. In particular, we observed that field exposure can cause an enhancement of Kv1.3 potassium conductance and that the effect lasts for several minutes after field removal. The results contribute to put immune and nervous system responses to extremely low-frequency electromagnetic fields into a new perspective, with Kv1.3 playing a pivotal molecular role. Keywords: immunotherapy, immunomodulation, potassium chann...
Extremely low-frequency electromagnetic fields cause DNA strand breaks in normal Vero cells
Cosmin Teodor Miha; Gabriela Vochita; Florin Brinza; Pincu Rotinberg
2013-01-23T23:59:59.000Z
Extremely low frequency electromagnetic fields aren't considered as a real carcinogenic agent despite the fact that some studies have showed impairment of the DNA integrity in different cells lines. The aim of this study was evaluation of the late effects of a 100 Hz and 5.6 mT electromagnetic field, applied continuously or discontinuously, on the DNA integrity of Vero cells assessed by alkaline Comet assay and by cell cycle analysis. Normal Vero cells were exposed to extremely low frequency electromagnetic fields (100 Hz, 5.6 mT) for 45 minutes. The Comet assay and cell cycle analysis were performed 48 hours after the treatment. Exposed samples presented an increase of the number of cells with high damaged DNA as compared with non-exposed cells. Quantitative evaluation of the comet assay showed a significantly ($cells. Cell cycle analysis showed an increase of the frequency of the cells in S phase, proving the occurrence of single strand breaks. The most probable mechanism of induction of the registered effects is the production of different types of reactive oxygen species.
Frequency shifts and relaxation rates for spin 1/2 particles moving in electromagnetic fields
Pignol, G; Petukhov, A; Golub, R
2015-01-01T23:59:59.000Z
We discuss the behaviour of the Larmor frequency shift and the longitudinal relaxation rate due to non-uniform electromagnetic fields on an assembly of spin 1/2 particles, in adiabatic and nonadiabatic regimes. We also show some general relations between the various frequency shifts and between the frequency shifts and relaxation rates. The remarkable feature of all our results is that they were obtained without any specific assumptions on the explicit form of the correlation functions of the fields. Hence, we expect that our results are valid both for diffusive and ballistic regime of motion and arbitrary cell shapes and surface scattering. These results can then be applied to a wide variety of realistic systems.
Mork, B; Nelson, R; Kirkendall, B; Stenvig, N
2009-11-30T23:59:59.000Z
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.
Koldanov, V. A.; Korobkov, S. V.; Gushchin, M. E.; Kostrov, A. V. [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation)
2011-08-15T23:59:59.000Z
The electromagnetic fields excited by circular loop antennas in a magnetized plasma in the whistler frequency range are simulated by the finite-difference time-domain method. The spatial structure of quasi-monochromatic fields excited in the near- and far-field zones by an antenna with a harmonic current, as well as the dynamics of the electromagnetic field excited by an antenna with a current in the form of a single video pulse, is studied. Simulations performed for a uniform plasma and uniform ambient magnetic field agree well with the results of theoretical analysis and model laboratory experiments performed on large-scale plasma devices.
Vallée, P; Legrand, L; Mentré, P; Monod, M O; Thomas, Y; Vall\\'{e}e, Philippe; Lafait, Jacques; Legrand, Laurent; Mentr\\'{e}, Pascale; Monod, Marie-Odile; Thomas, Yol\\`{e}ne
2005-01-01T23:59:59.000Z
Well-characterized purified water was exposed for 6 h to pulsed low-frequency weak electromagnetic fields. After various time periods, nondegassed and degassed water samples were analyzed by static light scattering. Just after electromagnetic exposure (day 0), a reduction of over 20% in the maximum light scattering intensity at 488 nm wavelength in both nondegassed and degassed samples was observed. By contrast, on day 12 the difference was observed only in nondegassed water samples. The latter effect was attributed to the different geometries of the containers combined with the basic origin of the whole phenomenon due to gas bubbles present in water. By the use of dynamic light scattering, the bubble mean diameter was estimated to be around 300 nm. Our results suggest that the electromagnetic exposure acts on gas nanobubbles present in water and emphasizes the role of the gas/liquid interface. The possibility that exposure to electromagnetic fields disturbs the ionic double-layer that contributes to bubble s...
Coherent hybrid electromagnetic field imaging
Cooke, Bradly J. (Jemez Springs, NM); Guenther, David C. (Los Alamos, NM)
2008-08-26T23:59:59.000Z
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.
Electromagnetic source localization with finite set of frequency measurements
Abdul Wahab; Amer Rasheed; Rab Nawaz; Saman Anjum
2014-09-16T23:59:59.000Z
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.
Narrow field electromagnetic sensor system and method
McEwan, T.E.
1996-11-19T23:59:59.000Z
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. 12 figs.
Narrow field electromagnetic sensor system and method
McEwan, Thomas E. (Livermore, CA)
1996-01-01T23:59:59.000Z
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.
Massless Dirac Fermions in Electromagnetic Field
Ahmed Jellal; Abderrahim El Mouhafid; Mohammed Daoud
2012-02-12T23:59:59.000Z
We study the relations between massless Dirac fermions in an electromagnetic field and atoms in quantum optics. After getting the solutions of the energy spectrum, we show that it is possible to reproduce the 2D Dirac Hamiltonian, with all its quantum relativistic effects, in a controllable system as a single trapped ion through the Jaynes--Cummings and anti-Jaynes--Cummings models. Also we show that under certain conditions the evolution of the Dirac Hamiltonian provides us with Rashba spin-orbit and linear Dresselhaus couplings. Considering the multimode multiphoton Jaynes-Cummings model interacting with N modes of electromagnetic field prepared in general pure quantum states, we analyze the Rabi oscillation. Evaluating time evolution of the Dirac position operator, we determine the Zitterbewegung frequency and the corresponding oscillating term as function of the electromagnetic field.
STIMULATED ELECTROMAGNETIC EMISSIONS BY HIGH-FREQUENCY ELECTROMAGNETIC PUMPING OF THE
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
H. C. Potter
2008-12-16T23:59:59.000Z
Gauge transformations are potential transformations that leave only specific Maxwell fields invariant. To reveal more, I develop Lorenz field equations with full Maxwell form for nongauge, sans gauge function, transformations yielding mixed, superposed retarded and outgoing, potentials. The form invariant Lorenz condition is then a charge conservation equivalent. This allows me to define three transformation classes that screen for Lorenz relevance. The nongauge Lorentz conditions add polarization fields which support emergent, light-like rays that convey energy on charge conserving phase points. These localized rays escape discovery in modern Maxwell fields where the polarizations are suppressed by gauge transformations.
Frequency-Domain Electromagnetics Survey At Kilauea East Rift...
FURUMOTO, 1976) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Frequency-Domain Electromagnetics Survey At Kilauea East Rift Geothermal Area...
Resonant circuit which provides dual-frequency excitation for rapid cycling of an electromagnet
Praeg, W.F.
1982-03-09T23:59:59.000Z
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.
Electromagnetic field with constraints and Papapetrou equation
Z. Ya. Turakulov; A. T. Muminov
2006-01-12T23:59:59.000Z
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.
Localization of fremions in rotating electromagnetic fields
B. V. Gisin
2015-06-15T23:59:59.000Z
Parameters of localization are defined in the lab and rotating frame for solutions of the Dirac equation in the field of a traveling circularly polarized electromagnetic wave and constant magnetic field. The radius of localization is of the order of the electromagnetic wavelength and lesser.
Noninvasive valve monitor using alternating electromagnetic field
Eissenberg, David M. (Oak Ridge, TN); Haynes, Howard D. (Knoxville, TN); Casada, Donald A. (Knoxville, TN)
1993-01-01T23:59:59.000Z
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.
Noninvasive valve monitor using alternating electromagnetic field
Eissenberg, D.M.; Haynes, H.D.; Casada, D.A.
1993-03-16T23:59:59.000Z
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.
Electromagnetic field with induced massive term: Case with scalar field
Yu. P. Rybakov; G. N. Shikin; Yu. A. Popov; Bijan Saha
2010-04-21T23:59:59.000Z
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.
Electromagnetic field with induced massive term: Case with spinor field
Yu. P. Rybakov; G. N. Shikin; Yu. A. Popov; Bijan Saha
2010-08-12T23:59:59.000Z
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.
Plasma confinement by circularly polarized electromagnetic field in toroidal geometry
Svidzinski, Vladimir A. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); and Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2007-10-15T23:59:59.000Z
A novel plasma confinement concept based on plasma confinement by electromagnetic pressure of circularly polarized electromagnetic fields is proposed. Practical implementation of this concept in a toroidal device is suggested. In this concept the confining field frequency is in the lower range such that the size of the device is much smaller than the vacuum wavelength. Most of the previous radio-frequency (rf) confinement concepts of unmagnetized plasma were related to confinement in rf cavities which operated at high frequency for which the size of the cavity is comparable to the wavelength. Operation at lower frequencies simplifies rf design, reduces Ohmic losses in the conducting walls and probably makes application of superconductors for wall materials more feasible. It is demonstrated that circular (or nearly circular) polarization of the electromagnetic field is required for confinement from both the equilibrium and stability considerations. Numerical analysis of plasma confinement for magnetohydrodynamic plasma model in two-dimensional toroidal geometry is performed. Within this model plasma is confined by the applied rf fields and its equilibrium is stable. Technically feasible compact and medium size toroidal plasma confinement devices based on this concept are proposed. Application of this approach to the fusion reactor requires use of superconducting materials for the toroidal shell to reduce the Ohmic losses. Further theoretical and experimental studies are required for a more reliable conclusion about the attractiveness of this plasma confinement concept.
The Electromagnetic Field as a Synchrony Gauge Field
Bock, Robert D
2015-01-01T23:59:59.000Z
Building on our previous work, we investigate the identification of the electromagnetic field as a local gauge field of a restricted group of synchrony transformations. We begin by arguing that the inability to measure the one-way speed of light independent of a synchronization scheme necessitates that physical laws must be reformulated without distant simultaneity. As a result, we are forced to introduce a new operational definition of time which leads to a fundamental space-time invariance principle that is related to a subset of the synchrony group. We identify the gauge field associated with this new invariance principle with the electromagnetic field. Consequently, the electromagnetic field acquires a space-time interpretation, as suggested in our previous work. In addition, we investigate the static, spherically symmetric solution of the resulting field equations. Also, we discuss implications of the present work for understanding the tension between classical and quantum theory.
Hydrodynamic construction of the electromagnetic field
Peter Holland
2014-10-03T23:59:59.000Z
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.
Frequency and temperature dependence in electromagnetic properties of Martian analog minerals
Stillman, David E.
Frequency and temperature dependence in electromagnetic properties of Martian analog minerals David), Frequency and temperature dependence in electromagnetic properties of Martian analog minerals, J. Geophys energy [Grimm et al., 2006]. Lastly, dielectric and magnetic relaxations of Martian subsurface minerals
Reflection and Transmission of Pulsed Electromagnetic Fields through Multilayered
Oughstun, Kurt
Reflection and Transmission of Pulsed Electromagnetic Fields through Multilayered Biological Media- cally rigorous, physically correct description of the propagation of pulsed electromagnetic fields pulses through multilayered biological media consisting of three biological tissue layers rep- resenting
Survey of ambient electromagnetic and radio-frequency interference levels in nuclear power plants
Kercel, S.W.; Moore, M.R.; Blakeman, E.D.; Ewing, P.D.; Wood, R.T.
1996-11-01T23:59:59.000Z
This document reports the results of a survey of ambient electromagnetic conditions in representative nuclear power plants. The U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research engaged the Oak Ridge National Laboratory (ORNL) to perform these measurements to characterize the electromagnetic interference (EMI) and radio-frequency interference (RFI) levels that can be expected in nuclear power plant environments. This survey is the first of its kind, being based on long-term unattended observations. The data presented in this report were measured at eight different nuclear units and required 14 months to collect. A representative sampling of power plant conditions (reactor type, operating mode, site location) monitored over extended observation periods (up to 5 weeks) were selected to more completely determine the characteristic electromagnetic environment for nuclear power plants. Radiated electric fields were measured over the frequency range of 5 MHz to 8 GHz. Radiated magnetic fields and conducted EMI events were measured over the frequency range of 305 Hz to 5 MHz. Highest strength observations of the electromagnetic ambient environment across all measurement conditions at each site provide frequency-dependent profiles for EMI/RFI levels in nuclear power plants.
Electromagnetic fields: Biological and clinical aspects
Tabrah, F.L.; Batkin, S. (Department of Physiology, University of Hawaii School of Medicine, Honolulu (USA))
1991-03-01T23:59:59.000Z
Our entire biosphere is immersed in a sea of man-made electromagnetic fields (EMF). Occupational and public health data suggest that these fields may be a health hazard, possibly involving cancer and fetal loss. This paper reviews the history and pertinent physics of electromagnetic fields and presents evidence from the authors' work, and that of others, of biological interaction with living systems. Epidemiological data suggesting EMF hazards are reviewed including a discussion of possible risks associated with Hawaii's Lualualei transmitter site, TV and FM antennas in high-density population areas, fields surrounding electric power transmission and computer terminals, and the plan to route a major highway through the near-field of an operating Omega signal-source. In the face of current public fear and controversial research reports about long-term EMF exposure, suggestions are presented for public policy about these local sources of concern, as well as for the EMF risks common to any similarly developed areas. 30 refs.
Epstein, Arthur J. (Columbus, OH); Morin, Brian G. (Columbus, OH)
1998-01-01T23:59:59.000Z
The invention presents a vanadium tetracyanoethylene solvent complex for electromagnetic field shielding, and a method for blocking low frequency and magnetic fields using these vanadium tetracyanoethylene compositions. The compositions of the invention can be produced at ambient temperature and are light weight, low density and flexible. The materials of the present invention are useful as magnetic shields to block low frequency fields and static fields, and for use in cores in transformers and motors.
Epstein, A.J.; Morin, B.G.
1998-10-13T23:59:59.000Z
The invention presents a vanadium tetracyanoethylene solvent complex for electromagnetic field shielding, and a method for blocking low frequency and magnetic fields using these vanadium tetracyanoethylene compositions. The compositions of the invention can be produced at ambient temperature and are light weight, low density and flexible. The materials of the present invention are useful as magnetic shields to block low frequency fields and static fields, and for use in cores in transformers and motors. 21 figs.
Vacuum birefringence in strong inhomogeneous electromagnetic fields
Karbstein, Felix; Reuter, Maria; Zepf, Matt
2015-01-01T23:59:59.000Z
Birefringence is one of the fascinating properties of the vacuum of quantum electrodynamics (QED) in strong electromagnetic fields. The scattering of linearly polarized incident probe photons into a perpendicularly polarized mode provides a distinct signature of the optical activity of the quantum vacuum and thus offers an excellent opportunity for a precision test of non-linear QED. Precision tests require accurate predictions and thus a theoretical framework that is capable of taking the detailed experimental geometry into account. We derive analytical solutions for vacuum birefringence which include the spatio-temporal field structure of a strong optical pump laser field and an x-ray probe. We show that the angular distribution of the scattered photons depends strongly on the interaction geometry and find that scattering of the perpendicularly polarized scattered photons out of the cone of the incident probe x-ray beam is the key to making the phenomenon experimentally accessible with the current generatio...
Cosmological electromagnetic fields due to gravitational wave perturbations Mattias Marklund*
Dunsby, Peter
show that this coupling leads to an initial pulse of electromagnetic waves whose width and amplitude to produce a pulse of gravitationally induced electromagnetic waves. In particular, because of the differentCosmological electromagnetic fields due to gravitational wave perturbations Mattias Marklund
Gauge Theory of the Gravitational-Electromagnetic Field
Robert D. Bock
2015-05-26T23:59:59.000Z
We develop a gauge theory of the combined gravitational-electromagnetic field by expanding the Poincar\\'e group to include clock synchronization transformations. We show that the electromagnetic field can be interpreted as a local gauge theory of the synchrony group. According to this interpretation, the electromagnetic field equations possess nonlinear terms and electromagnetic gauge transformations acquire a space-time interpretation as local synchrony transformations. The free Lagrangian for the fields leads to the usual Einstein-Maxwell field equations with additional gravitational-electromagnetic coupling terms. The connection between the electromagnetic field and the invariance properties of the Lagrangian under clock synchronization transformations provides a strong theoretical argument in favor of the thesis of the conventionality of simultaneity. This suggests that clock synchronization invariance (or equivalently, invariance under transformations of the one-way speed of light) is a fundamental invariance principle of physics.
High frequency electromagnetic burn monitoring for underground coal gasification
Deadrick, F.J.; Hill, R.W.; Laine, E.F.
1981-06-17T23:59:59.000Z
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.
Waveguide-based Ultrasonic and Far-field Electromagnetic Sensors...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
waveguide-based ultrasonic and far- field electromagnetic sensors to measure key Enhanced Geothermal Systems (EGS) reservoir parameters, including directional temperature,...
Texas at Austin, University of
Large Dynamic Range Electromagnetic FieldLarge Dynamic Range Electromagnetic Field Sensor based on Domain Inverted Electro-Optic Polymer Directional CouplerPolymer Directional Coupler Alan X. Wang Ray T. Chen Omega Optics Inc Austin TXOmega Optics Inc., Austin, TX -1- #12;Application of Electric Field
Three-Dimensional Electromagnetic High Frequency Axisymmetric Cavity Scars.
Warne, Larry K.; Jorgenson, Roy E.
2014-10-01T23:59:59.000Z
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
Characterization of microstructure with low frequency electromagnetic techniques
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
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.
The universal C*-algebra of the electromagnetic field
Buchholz, Detlev; Ruzzi, Giuseppe; Vasselli, Ezio
2015-01-01T23:59:59.000Z
A universal C*-algebra of the electromagnetic field is constructed. It is represented in any quantum field theory which incorporates electromagnetism and expresses basic features of this field such as Maxwell's equations, Poincar\\'e covariance and Einstein causality. Moreover, topological properties of the field resulting from Maxwell's equations are encoded in the algebra, leading to commutation relations with values in its center. The representation theory of the algebra is discussed with focus on vacuum representations, fixing the dynamics of the field.
Cosmic Electromagnetic Fields due to Perturbations in the Gravitational Field
Bishop Mongwane; Peter K. S. Dunsby; Bob Osano
2012-10-21T23:59:59.000Z
We use non-linear gauge-invariant perturbation theory to study the interaction of an inflation produced seed magnetic field with density and gravitational wave perturbations in an almost Friedmann-Lema\\^itre-Robertson-Walker (FLRW) spacetime. We compare the effects of this coupling under the assumptions of poor conductivity, infinite conductivity and the case where the electric field is sourced via the coupling of velocity perturbations to the seed field in the ideal magnetohydrodynamic (MHD) regime, thus generalizing, improving on and correcting previous results. We solve our equations for long wavelength limits and numerically integrate the resulting equations to generate power spectra for the electromagnetic field variables, showing where the modes cross the horizon. We find that the rotation of the electric field dominates the power spectrum on small scales, in agreement with previous arguments.
Electromagnetic field at Finite Temperature: A first order approach
R. Casana; B. M. Pimentel; J. S. Valverde
2007-02-04T23:59:59.000Z
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.
An Obliquely Propagating Electromagnetic Drift Instability in the Lower Hybrid Frequency Range
Hantao Ji; Russell Kulsrud; William Fox; Masaaki Yamada
2005-06-10T23:59:59.000Z
By employing a local two-fluid theory, we investigate an obliquely propagating electromagnetic instability in the lower hybrid frequency range driven by cross-field current or relative drifts between electrons and ions. The theory self-consistently takes into account local cross-field current and accompanying pressure gradients. It is found that the instability is caused by reactive coupling between the backward propagating whistler (fast) waves in the moving electron frame, and the forward propagating sound (slow) waves in the ion frame when the relative drifts are large. The unstable waves we consider propagate obliquely to the unperturbed magnetic field and have mixed polarization with significant electromagnetic components. A physical picture of the instability emerges in the limit of large wave number characteristic of the local approximation. The primary positive feedback mechanism is based on reinforcement of initial electron density perturbations by compression of electron fluid via induced Lorentz force. The resultant waves are qualitatively consistent with the measured electromagnetic fluctuations in reconnecting current sheet in a laboratory plasma.
Gravity Control by means of Electromagnetic Field through Gas or Plasma at Ultra-Low Pressure
Fran De Aquino
2013-12-02T23:59:59.000Z
It is shown that the gravity acceleration just above a chamber filled with gas or plasma at ultra-low pressure can be strongly reduced by applying an Extra Low-Frequency (ELF) electromagnetic field across the gas or the plasma. This Gravitational Shielding Effect is related to recent discovery of quantum correlation between gravitational mass and inertial mass. According to the theory samples hung above the gas or the plasma should exhibit a weight decrease when the frequency of the electromagnetic field is decreased or when the intensity of the electromagnetic field is increased. This Gravitational Shielding Effect is unprecedented in the literature and can not be understood in the framework of the General Relativity. From the technical point of view, there are several applications for this discovery; possibly it will change the paradigms of energy generation, transportation and telecommunications.
Chang, Ray-Yuan; Fang, Wei-Chia; Lee, Ming-Tsung; He, Zong-Syun; Ke, Bai-Cian [Department of Physics, National Cheng-Kung University, Tainan 70101, Taiwan (China); Lee, Yi-Chi [Institute of Electro-Optical Science and Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China); Tsai, Chin-Chun [Department of Physics, National Cheng-Kung University, Tainan 70101, Taiwan (China); Institute of Electro-Optical Science and Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China)
2010-01-15T23:59:59.000Z
This investigation clarifies the transition phenomenon between the electromagnetically induced transparency (EIT) and Raman absorption in a ladder-type system of Doppler-broadened cesium vapor. A competition window of this transition was found to be as narrow as 2 MHz defined by the probe Rabi frequency. For a weak probe, the spectrum of EIT associated with quantum interference suggests that the effect of the Doppler velocity on the spectrum is negligible. When the Rabi frequency of the probe becomes comparable with the effective decay rate, an electromagnetically induced absorption (EIA) dip emerges at the center of the power broadened EIT peak. While the Rabi frequency of the probe exceeds the effective decay rate, decoherence that is generated by the intensified probe field occurs and Raman absorption dominates the interaction process, yielding a pure absorption spectrum; the Doppler velocity plays an important role in the interaction. A theory that is based on density matrix simulation, with or without the Doppler effect, can qualitatively fit the experimental data. In this work, the coherence of atom-photon interactions is created or destroyed using the probe Rabi frequency as a decoherence source.
Electromagnetic Field Creation During EWPT Nucleation With Lepton Currents
Leonard S. Kisslinger; Sameer Walawalkar; Ernest M. Henley; Mikkel B. Johnson
2005-10-11T23:59:59.000Z
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.
Julius Vanko; Miroslav Sukenik; Jozef Sima
2007-05-29T23:59:59.000Z
Including Vaidya metric into the model of Expansive Nondecelerative Universe allows to localize the energy of gravitational field. A term of effective gravitational range is introduced and classic Newton potential is substituted for Yukawa-type potential. It allows to allocate a typical frequency value to each gravitational field. Derived theoretical conclusions led us to investigate the effect of electromagnetic field with a precisely predetermined frequency and intensity on iron. We believe that under certain circumstances a decrease in iron gravitational mass should be observed. Two model experiments verifying the theoretical conclusions are proposed.
Inomoto, Michiaki; Tanabe, Hiroshi; Ono, Yasushi [Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan)] [Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Kuwahata, Akihiro [Graduate School of Engineering, The University of Tokyo,7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan)] [Graduate School of Engineering, The University of Tokyo,7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Collaboration: TS Group
2013-06-15T23:59:59.000Z
Large-amplitude electromagnetic fluctuations of ion-cyclotron-frequency range are detected in a laboratory experiment inside the diffusion region of a magnetic reconnection with a guide field. The fluctuations have properties similar to kinetic Alfvén waves propagating obliquely to the guide field. Temporary enhancement of the reconnection rate is observed during the occurrence of the fluctuations, suggesting a relationship between the modification in the local magnetic structure given by these fluctuations and the intermittent fast magnetic reconnection.
Rydberg Atoms Ionisation by Microwave Field and Electromagnetic Pulses
B. Kaulakys; G. Vilutis
1995-04-10T23:59:59.000Z
A simple theory of the Rydberg atoms ionisation by electromagnetic pulses and microwave field is presented. The analysis is based on the scale transformation which reduces the number of parameters and reveals the functional dependencies of the processes. It is shown that the observed ionisation of Rydberg atoms by subpicosecond electromagnetic pulses scale classically. The threshold electric field required to ionise a Rydberg state may be simply evaluated in the photonic basis approach for the quantum dynamics or from the multiphoton ionisation theory.
Space-Time Galerkin Projection of Electro-Magnetic Fields
Wang, Zifu; Hofmann, Heath
2015-01-01T23:59:59.000Z
Spatial Galerkin projection transfers fields between different meshes. In the area of finite element analysis of electromagnetic fields, it provides great convenience for remeshing, multi-physics, domain decomposition methods, etc. In this paper, a space-time Galerkin projection is developed in order to transfer fields between different spatial and temporal discretization bases.
Asymptotic description of pulsed ultrawideband electromagnetic beam field
Oughstun, Kurt
Asymptotic description of pulsed ultrawideband electromagnetic beam field propagation in dispersive of a pulsed ultrawideband electro- magnetic beam field as it propagates through a dispersive, attenuative evolution of the pulsed-beam field through a single-contour integral that is of the same form
Electromagnetic field of a charge intersecting a cold plasma boundary in a waveguide
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
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.
Kuzmin, Dmitry A; Shavrov, Vladimir G
2014-01-01T23:59:59.000Z
Electrodynamic properties of the graphene - magnetic semiconductor - graphene superlattice placed in magnetic field have been investigated theoretically in Faraday geometry with taking into account dissipation processes. Frequency and field dependences of the reflectance, transmittance and absorbtance of electromagnetic waves by such superlattice have been calculated for different numbers of periods of the structure and different sizes of the periods with using a transfer matrix method. The possibility of efficient control of electrodynamic properties of graphene - magnetic semiconductor - graphene superlattice has been shown.
Electromagnetic Field Quantization in Time-Dependent Dielectric Media
Xiao-Min Bei; Zhong-Zhu Liu
2011-04-18T23:59:59.000Z
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.
ECE 341: Electromagnetic Fields I EM devices and systems
Schumacher, Russ
- Power systems - Electromagnetic compatibility - Modeling of transmission lines - Communications model electric and magnetic properties of material media in relation with field equations - Understands and appreciates EM field theory as a foundation of circuit theory and electrical engineering as a whole Maxwell
Lattice p-Form Electromagnetism and Chain Field Theory
Derek K. Wise
2005-10-08T23:59:59.000Z
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.
Florida, University of
of both the incident lightning electromagnetic pulse (LEMP) and the effects of coupling of this field- mental validation using: 1) reduced-scale setups with LEMP and nuclear electromagnetic pulse (NEMP532 IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY, VOL. 51, NO. 3, AUGUST 2009 Lightning
Electromagnetic and mechanical design of gridded radio-frequency cavity windows
Alsharo'a, Mohammad M.
2004-12-01T23:59:59.000Z
Electromagnetic, thermal and structural analyses of radio-frequency (RF) cavities were performed as part of a developmental RF cavity program for muon cooling. RF cavities are necessary to provide longitudinal focusing of the muons and to compensate for their energy loss. Closing the cavity ends by electrically conducting windows reduces the power requirement and increases the on-axis electric field for a given maximum surface electric field. Many factors must be considered in the design of RF cavity windows. RF heating can cause the windows to deform in the axial direction of the cavity. The resulting thermal stresses in the window must be maintained below the yield stress of the window material. The out-of-plane deflection must be small enough so that the consequent frequency shift is tolerable. For example, for an 805 MHz cavity, the out-of-plane deflection must be kept below 25 microns to prevent the frequency of the cavity from shifting more than 10 kHz. In addition, the window design should yield smooth electric and magnetic fields, terminate field leakage beyond the window, and minimize beam scattering. In the present thesis, gridded-tube window designs were considered because of their high structural integrity. As a starting point in the analysis, a cylindrical pillbox cavity was considered as a benchmark problem. Analytical and finite element solutions were obtained for the electric and magnetic fields, power loss density, and temperature profile. Excellent agreement was obtained between the analytical and finite element results. The finite element method was then used to study a variety of gridded-tube windows. It was found that cooling of the gridded-tube windows by passing helium gas inside the tubes significantly reduces the out-of-plane deflection and the thermal stresses. Certain tube geometries and grid patterns were found to satisfy all of the design requirements.
A Continuous Field Theory of Matter and Electromagnetism
Raymond J. Beach
2012-08-31T23:59:59.000Z
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.
Gravitational Hertz experiment with electromagnetic radiation in a strong magnetic field
N. I. Kolosnitsyn; V. N. Rudenko
2015-04-24T23:59:59.000Z
Brief review of principal ideas in respect of the high frequency gravitational radiation generated and detected in the laboratory condition is presented. Interaction of electro-magnetic and gravitational waves into a strong magnetic field is considered as a more promising variant of the laboratory GW-Hertz experiment. The formulae of the direct and inverse Gertsenshtein-Zeldovich effect are derived. Numerical estimates are given and a discussion of a possibility of observation of these effects in a lab is carried out.
Does three dimensional electromagnetic field inherit the spacetime symmetries?
Cvitan, Maro; Smoli?, Ivica
2015-01-01T23:59:59.000Z
We prove that the electromagnetic field in a (1+2)-dimensional spacetime necessarily inherits the symmetries of the spacetime metric in a large class of generalized Einstein-Maxwell theories. The Lagrangians of the studied theories have general diff-covariant gravitational part and include both the gravitational and the gauge Chern-Simons terms.
Electromagnetically induced transparency with quantized fields in optocavity mechanics
Huang Sumei; Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)
2011-04-15T23:59:59.000Z
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.
Electromagnetic field quantization in a linear dielectric medium
F. Kheirandish; M. Amooshahi
2005-11-13T23:59:59.000Z
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.
Spectrally isomorphic Dirac systems: graphene in electromagnetic field
Vit Jakubsky
2014-12-02T23:59:59.000Z
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.
Khan, S. A. [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Ayub, M. K. [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Pohang University of Science and Technology (POSTECH), Pohang, Gyunbuk 790-784 (Korea, Republic of); Ahmad, Ali [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)
2012-10-15T23:59:59.000Z
Quantum plasma oscillations are studied in a strongly magnetized, ultra-dense plasma with degenerate electrons and positrons. The dispersive role of electron and positron quantum effects on low frequency (in comparison to electron cyclotron frequency) shear electromagnetic wave is investigated by employing hydrodynamic formulation. In the presence of ions, the density balance changes, and the electromagnetic wave (with frequency lower than the ion cyclotron frequency) is shown to couple with electrostatic ion mode under certain conditions. For such low frequency waves, it is also seen that the contribution of electron and positron degeneracy pressure is dominant as compared to their diffraction effects. The results are analyzed numerically for illustrative purpose pointing out their relevance to the dense laboratory (e.g., super-intense laser-dense matter interactions) and astrophysical plasmas.
Low-Frequency Electromagnetic Response Function for Strong-Coupling Superconductors
SCHOLTEN, PD; LEJEUNE, JD; SASLOW, WM; Naugle, Donald G.
1977-01-01T23:59:59.000Z
PHYSICAL REVIE% B VOLUME 16, NUMBER 3 1 AUGUST 1977 Low-frequency electromagnetic response function for strong-coupling superconfluctors* P. D. Scholten, J. D. Lejeune, t O'. M. Saslow, and D. G. Naugle Department of Physics, Texas A8r...M University, College Station, Texas 77843 (Received 1 March 1977) A simple method for calculating the low-frequency electromagnetic response function from tunneling derived a'(co)F(co) has been developed and applied to Pb, Pbog0810lo amorphous Bi, amorphous...
Norin, L.; Leyser, T. B.; Nordblad, E.; Thide, B.; McCarrick, M. [Swedish Institute of Space Physics, Uppsala (Sweden); BAE Systems Advanced Technologies, Washington, D.C. (United States)
2009-02-13T23:59:59.000Z
Experimental results of secondary electromagnetic radiation, stimulated by high-frequency radio waves irradiating the ionosphere, are reported. We have observed emission peaks, shifted in frequency up to a few tens of Hertz from radio waves transmitted at several megahertz. These emission peaks are by far the strongest spectral features of secondary radiation that have been reported. The emissions are attributed to stimulated Brillouin scattering, long predicted but hitherto never unambiguously identified in high-frequency ionospheric interaction experiments. The experiments were performed at the High-Frequency Active Auroral Research Program (HAARP), Alaska, USA.
Low frequency electrostatic and electromagnetic modes in nonuniform cold quantum plasmas
Saleem, H.; Ahmad, Ali [Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Khan, S. A. [Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Department of Physics, Government College Bagh AJK (Pakistan)
2008-01-15T23:59:59.000Z
The low frequency electrostatic and electromagnetic linear modes in a nonuniform cold quantum electron-ion plasma are studied. The effect of stationary dust on an electrostatic mode is also investigated. The quantum corrections in the linear dispersion relations of a cold dense plasma are presented with possible applications.
Ion acoustic wave generation by a standing electromagnetic field in a subcritical plasma
Boyer, Edmond
by the ponderomotive force [1] associated with a standing electromagnetic pulse. Be- cause of the nonlinear response of the plasma to the electromagnetic pulse, a zero frequency electron den- sity perturbation is created with a wave number twice the electromagnetic one. Then, after the pulse, the plasma relaxes towards
Clark, M. Collins (Albuquerque, NM); Coleman, P. Dale (Albuquerque, NM); Marder, Barry M. (Albuquerque, NM)
1993-01-01T23:59:59.000Z
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.
Photon propagation in slowly varying inhomogeneous electromagnetic fields
Felix Karbstein; Rashid Shaisultanov
2015-04-23T23:59:59.000Z
Starting from the Heisenberg-Euler effective Lagrangian, we determine the photon current and photon polarization tensor in inhomogeneous, slowly varying electromagnetic fields. To this end, we consider background field configurations varying in both space and time, paying special attention to the tensor structure. As a main result, we obtain compact analytical expressions for the photon polarization tensor in realistic Gaussian laser pulses, as generated in the focal spots of high-intensity lasers. These expressions are of utmost importance for the investigation of quantum vacuum nonlinearities in realistic high-intensity laser experiments.
Photon propagation in slowly varying inhomogeneous electromagnetic fields
Karbstein, Felix
2015-01-01T23:59:59.000Z
Starting from the Heisenberg-Euler effective Lagrangian, we determine the photon current and photon polarization tensor in inhomogeneous, slowly varying electromagnetic fields. To this end, we consider background field configurations varying in both space and time, paying special attention to the tensor structure. As a main result, we obtain compact analytical expressions for the photon polarization tensor in realistic Gaussian laser pulses, as generated in the focal spots of high-intensity lasers. These expressions are of utmost importance for the investigation of quantum vacuum nonlinearities in realistic high-intensity laser experiments.
Kuzmin, Dmitry A; Shavrov, Vladimir G
2014-01-01T23:59:59.000Z
Electrodynamic properties of the graphene - magnetic semiconductor - graphene sandwich-structure have been investigated theoretically with taking into account the dissipation processes. Influence of graphene layers on electromagnetic waves propagation in graphene - semi-infinte magnetic semiconductor and graphene - magnetic semiconductor - graphene sandwich-structure has been analyzed. Frequency and field dependences of the reflectance, transmittance and absorbtance of electromagnetic waves by such structure have been calculated. The size effects associated with the thickness of the structure have been analyzed. The possibility of efficient control of electrodynamic properties of graphene - magnetic semiconductor - graphene sandwich structure by an external magnetic field has been shown.
Rayleigh-Taylor-Induced electromagnetic fields in laser-produced plasmas
Manuel, Mario John-Errol
2013-01-01T23:59:59.000Z
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 ...
Instability-driven electromagnetic fields in coronal plasmas
Manuel, M. J.-E.; Li, C. K.; Séguin, F. H.; Sinenian, N.; Frenje, J. A.; Casey, D. T.; Petrasso, R. D. [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); Hager, J. D.; Betti, R.; Hu, S. X.; Delettrez, J.; Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York, 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, Rochester, New York, 14623 (United States)
2013-05-15T23:59:59.000Z
Filamentary electromagnetic fields previously observed in the coronae of laser-driven spherical targets [F. H. Séguin 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 ?210 ?m 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.
Instability-driven electromagnetic fields in coronal plasmas
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
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.; et al
2013-04-15T23:59:59.000Z
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 densitymore »profiles, the fastest growing modes of this instability were found to be slowly varying in time and consistent with the observed cellular size.« less
Instability-driven electromagnetic fields in coronal plasmas
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
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
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.
Variational Principles for Constrained Electromagnetic Field and Papapetrou Equation
A. T. Muminov
2007-06-28T23:59:59.000Z
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.
Poignard, Clair
, the governments have imposed some limitations to the authorized radiated fields by the power systems. It has been a more acceptable limit to these radiated fields. On the other hand, electromagnetic fields are used is obtained by submitting locally the patient to a radiofrequency (RF) electromagnetic field. The focalization
An improved model of the lightning electromagnetic field interaction with the D-region ionosphere
14 March 2012. [1] We present an improved time-domain model of the lightning electromagnetic pulse. Introduction [2] Lightning discharges produce both an electromagnetic pulse (EMP), due to the rapid lightningAn improved model of the lightning electromagnetic field interaction with the D-region ionosphere R
Electromagnetic field limits set by the V-Curve.
Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Hudson, Howard Gerald
2014-07-01T23:59:59.000Z
When emitters of electromagnetic energy are operated in the vicinity of sensitive components, the electric field at the component location must be kept below a certain level in order to prevent the component from being damaged, or in the case of electro-explosive devices, initiating. The V-Curve is a convenient way to set the electric field limit because it requires minimal information about the problem configuration. In this report we will discuss the basis for the V-Curve. We also consider deviations from the original V-Curve resulting from inductive versus capacitive antennas, increases in directivity gain for long antennas, decreases in input impedance when operating in a bounded region, and mismatches dictated by transmission line losses. In addition, we consider mitigating effects resulting from limited antenna sizes.
Geometric entropy and edge modes of the electromagnetic field
William Donnelly; Aron C. Wall
2015-06-18T23:59:59.000Z
We calculate the vacuum entanglement entropy of Maxwell theory in a class of curved spacetimes by Kaluza-Klein reduction of the theory onto a two-dimensional base manifold. Using two-dimensional duality, we express the geometric entropy of the electromagnetic field as the entropy of a tower of scalar fields, constant electric and magnetic fluxes, and a contact term, whose leading order divergence was discovered by Kabat. The complete contact term takes the form of one negative scalar degree of freedom confined to the entangling surface. We show that the geometric entropy agrees with a statistical definition of entanglement entropy that includes edge modes: classical solutions determined by their boundary values on the entangling surface. This resolves a longstanding puzzle about the statistical interpretation of the contact term in the entanglement entropy. We discuss the implications of this negative term for black hole thermodynamics and the renormalization of Newton's constant.
Electromagnetic field triggered drug and chemical delivery via liposomes
Liburdy, Robert P. (1820 Mountain View Rd., Tiburon, CA 94920)
1993-01-01T23:59:59.000Z
The present invention relates to a system and to a method of delivering a drug to a preselected target body site of a patient, comprising the steps of encapsulating the chemical agent within liposomes, essentially temperature insensitive, i.e. not having a specific predetermined phase transition temperature within the specific temperature range of drug administration; administering the liposomes to the target body site; and subjecting the target body site to nonionizing electromagnetic fields in an area of the preselected target body in order to release said chemical agent from the liposomes at a temperature of between about +10 and 65.degree. C. The invention further relates to the use of said liposomes to bind to the surface of or to enter target tissue or an organ in a living system, and, when subjected to a nonionizing field, to release a drug from the liposomes into the target site.
Electromagnetic field triggered drug and chemical delivery via liposomes
Liburdy, R.P.
1993-03-02T23:59:59.000Z
The present invention relates to a system and to a method of delivering a drug to a preselected target body site of a patient, comprising the steps of encapsulating the chemical agent within liposomes, essentially temperature insensitive, i.e. not having a specific predetermined phase transition temperature within the specific temperature range of drug administration; administering the liposomes to the target body site; and subjecting the target body site to nonionizing electromagnetic fields in an area of the preselected target body in order to release the chemical agent from the liposomes at a temperature of between about +10 and 65 C. The invention further relates to the use of the liposomes to bind to the surface of or to enter target tissue or an organ in a living system, and, when subjected to a nonionizing field, to release a drug from the liposomes into the target site.
Electromagnetic field objects in terms of Balance of Geometric flows
Donev, Stoil
2015-01-01T23:59:59.000Z
This paper reviews our physical motivation for choosing appropriate formal presentation of electromagnetic field objects (EMFO). Our view is based on the understanding that EMFO are spatially finite entities carrying internal dynamical structure, so, their available integral time stability should be represented by appropriate adaptation of their internal dynamical structure to corresponding local stress-energy-momentum balance relations with other physical objects. This adaptation process has two aspects: internal and external. Clearly, finding adequate internal dynamical structure giving appropriate integral characteristics of the object, will bring also appropriate behavior of EMFO as a whole. Therefore, the internal local stress-energy-momentum balance among the subsystems of EMFO should formally be presented by appropriately defined tensor-field quantities, which are meant to suggest a dynamical understanding of the abilities of EMFO to successfully communicate with all the rest physical world.
Electromagnetic field objects in terms of Balance of Geometric flows
Stoil Donev; Maria Tashkova
2015-08-26T23:59:59.000Z
This paper reviews our physical motivation for choosing appropriate formal presentation of electromagnetic field objects (EMFO). Our view is based on the understanding that EMFO are spatially finite entities carrying internal dynamical structure, so, their available integral time stability should be represented by appropriate adaptation of their internal dynamical structure to corresponding local stress-energy-momentum balance relations with other physical objects. This adaptation process has two aspects: internal and external. Clearly, finding adequate internal dynamical structure giving appropriate integral characteristics of the object, will bring also appropriate behavior of EMFO as a whole. Therefore, the internal local stress-energy-momentum balance among the subsystems of EMFO should formally be presented by appropriately defined tensor-field quantities, which are meant to suggest a dynamical understanding of the abilities of EMFO to successfully communicate with all the rest physical world.
O. V. Veko; N. D Vlasii; Yu. A. Sitenko; E. M. Ovsiyuk; V. M. Red'kov
2014-10-30T23:59:59.000Z
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.
Quantum Energy Teleportation with Electromagnetic Field: Discrete vs. Continuous Variables
Hotta, Masahiro
2009-01-01T23:59:59.000Z
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...
Latyshev, A V
2015-01-01T23:59:59.000Z
From kinetic Vlasov equation for collisional plasmas distribution function is received in square-law approximation on size of electromagnetic field. The formula for calculation electric current is deduced at any temperature (any degree of degeneration electronic gas). This formula contains one-dimension quadrature. It is shown, that the nonlinearity account leads to occurrence the longitudinal electric current directed along a wave vector. This longitudinal current is perpendicular to the known transversal classical current, received at the linear analysis. When frequency of collisions tends to zero, all received results for collisional plasma pass in known corresponding formulas for collisionless plasma. The case of small values of wave number is considered. It is shown, that the received quantity of longitudinal current at tendency of frequency of collisions to zero also passes in known corresponding expression of current for collisionless plasmas. Graphic comparison of dimensionless size of current is spen...
Waveguide-based Ultrasonic and Far-field Electromagnetic Sensors...
waveguide-based ultrasonic and farfield electromagnetic sensors to measure key Enhanced Geothermal Systems (EGS) reservoir parameters, including directional temperature,...
Three-dimensional superintegrable systems in a static electromagnetic field
Antonella Marchesiello; Libor Snobl; Pavel Winternitz
2015-07-16T23:59:59.000Z
We consider a charged particle moving in a static electromagnetic field described by the vector potential $\\vec A(\\vec x)$ and the electrostatic potential $V(\\vec x)$. We study the conditions on the structure of the integrals of motion of the first and second order in momenta, in particular how they are influenced by the gauge invariance of the problem. Next, we concentrate on the three possibilities for integrability arising from the first order integrals corresponding to three nonequivalent subalgebras of the Euclidean algebra, namely $(P_1,P_2)$, $(L_3,P_3)$ and $(L_1,L_2,L_3)$. For these cases we look for additional independent integrals of first or second order in the momenta. These would make the system superintegrable (minimally or maximally). We study their quantum spectra and classical equations of motion. In some cases nonpolynomial integrals of motion occur and ensure maximal superintegrability.
Electromagnetic pulse (EMP), Part I: Effects on field medical equipment
Vandre, R.H.; Klebers, J.; Tesche, F.M.; Blanchard, J.P. (Walter Reed Army Medical Center, Washington, DC (United States))
1993-04-01T23:59:59.000Z
The electromagnetic pulse (EMP) from a high-altitude nuclear detonation has the potential to cover an area as large as the continental United States with damaging levels of EMP radiation. In this study, two of seven items of medical equipment were damaged by an EMP simulator. Computer circuit analysis of 17 different items showed that 11 of the 17 items would be damaged by current surges on the power cords, while two would be damaged by current surges on external leads. This research showed that a field commander can expect approximately 65% of his electronic medical equipment to be damaged by a single nuclear detonation as far as 2,200 km away.
Low-Frequency Electromagnetic Response Function for Strong-Coupling Superconductors
SCHOLTEN, PD; LEJEUNE, JD; SASLOW, WM; Naugle, Donald G.
1977-01-01T23:59:59.000Z
VOLUME 16, NUMBER 3 1 AUGUST 1977 Low-frequency electromagnetic response function for strong-coupling superconfluctors* P. D. Scholten, J. D. Lejeune, t O'. M. Saslow, and D. G. Naugle Department of Physics, Texas A8rM University, College Station... stream_source_info PhysRevB.16.1068.pdf.txt stream_content_type text/plain stream_size 37501 Content-Encoding ISO-8859-1 stream_name PhysRevB.16.1068.pdf.txt Content-Type text/plain; charset=ISO-8859-1 PHYSICAL REVIE% B...
R. P. Abel; A. K. Mohapatra; M. G. Bason; J. D. Pritchard; K. J. Weatherill; U. Raitzsch; C. S. Adams
2009-03-05T23:59:59.000Z
We demonstrate laser frequency stabilization to excited state transitions using cascade electromagnetically induced transparency (EIT). Using a room temperature Rb vapor cell as a reference, we stabilize a first diode laser to the D2 transition and a second laser to a transition from the intermediate state to a Rydberg state with principal quantum number n=19 - 70. A combined laser linewidth of 280 kHz over a 0.1 ms time period is achieved. This method may be applied generally to any cascade system and allows laser stabilization to an atomic reference in the absence of strong optical transitions.
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
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.
Electromagnetically induced transparency controlled by a microwave field
Li, Hebin; Sautenkov, Vladimir A.; Rostovtsev, Yuri V.; Welch, George R.; Hemmer, Philip R.; Scully, Marlan O.
2009-01-01T23:59:59.000Z
interferences in electromagnetically induced transparency. A simple theoretical model and a numerical simulation have been developed to explain the observed experimental results....
6.641 Electromagnetic Fields, Forces, and Motion, Spring 2003
Zahn, Markus, 1946-
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 ...
Electromagnetic Theory 1 /56 Electromagnetic Theory
Bicknell, Geoff
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
Exact solution to the Landau-Lifshitz equation in a constant electromagnetic field
Yurij Yaremko
2014-12-04T23:59:59.000Z
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.
Dynamic model for electromagnetic field and heating patterns in loaded cylindrical cavities
Tian, Y.L.; Black, W.M.; Sa`adaldin, H.S. [George Mason Univ., Fairfax, VA (United States). Dept. of Electrical and Computer Engineering; Ahmad, I.; Silberglitt, R. [FM Technologies, Inc., Fairfax, VA (United States)
1995-07-01T23:59:59.000Z
An analytical solution for the electromagnetic fields in a cylindrical cavity, partially filled with a cylindrical dielectric has been recently reported. A program based on this solution has been developed and combined with the authors` previous program for heat transfer analysis. The new software has been used to simulate the dynamic temperature profiles of microwave heating and to investigate the role of electromagnetic field in heating uniformity and stability. The effects of cavity mode, cavity dimension, the dielectric properties of loads on electromagnetic field and heating patterns can be predicted using this software.
An ab initio derivation of electromagnetic fields of an accelerated charge
Singal, Ashok K
2011-01-01T23:59:59.000Z
Electromagnetic fields of an accelerated charge are derived from the first principles using Coulomb's law and the relativistic transformations. The electric and magnetic fields are derived first for an instantaneous rest frame of the accelerated charge, without making explicit use of Gauss law, an approach different from that available in the literature. Thereafter we calculate the electromagnetic fields for an accelerated charge having a non-relativistic motion. The expressions for these fields, supposedly accurate only to first order in velocity $\\beta$, surprisingly yield all terms exactly for the acceleration fields, only missing is a factor $1-\\beta^2$ in the velocity fields. The derivation explicitly shows the genesis of various terms in the field expressions, when expressed with respect to the time retarded position of the charge. A straightforward transformation from the instantaneous rest frame, using relativistic Doppler factors, yields expressions of the electromagnetic fields for the charge moving...
Gravitation and electromagnetism in theory of a unified four-vector field
Alexander A. Chernitskii
2006-09-28T23:59:59.000Z
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.
Electromagnetic fields and transport coefficients in a hot pion gas
A. Gomez Nicola; D. Fernandez-Fraile
2006-08-24T23:59:59.000Z
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.
Electromagnetic fields and anomalous transports in heavy-ion collisions --- A pedagogical review
Huang, Xu-Guang
2015-01-01T23:59:59.000Z
The hot and dense matter generated in heavy-ion collisions may contain domains in which the P and CP symmetries of QCD are violated. Moreover, heavy-ion collisions can generate extremely strong magnetic fields as well as electric fields. The interplay among the electromagnetic field, triangle anomaly, and the P and CP violation of QCD leads to a number of macroscopic quantum phenomena known as the anomalous transports. The purpose of the article is to give a pedagogical review of various properties of the electromagnetic fields, the anomalous transports phenomena, and their experimental signatures in heavy-ion collisions.
Electromagnetic fields and anomalous transports in heavy-ion collisions --- A pedagogical review
Xu-Guang Huang
2015-09-14T23:59:59.000Z
The hot and dense matter generated in heavy-ion collisions may contain domains in which the P and CP symmetries of QCD are violated. Moreover, heavy-ion collisions can generate extremely strong magnetic fields as well as electric fields. The interplay among the electromagnetic field, triangle anomaly, and the P and CP violation of QCD leads to a number of macroscopic quantum phenomena known as the anomalous transports. The purpose of the article is to give a pedagogical review of various properties of the electromagnetic fields, the anomalous transports phenomena, and their experimental signatures in heavy-ion collisions.
Definition of the Electromagnetic Field in the Broken-Symmetry Phase of the Electroweak Theory
Ola Tornkvist
1998-05-08T23:59:59.000Z
In the broken-symmetry phase of the electroweak theory there is no unique definition of the electromagnetic field tensor in cases where the magnitude of the Higgs field differs from a constant value. The meaning of the electromagnetic field is therefore dubious near defects and during non-equilibrium stages of the electroweak phase transition. Nevertheless, by imposing a minimal set of natural requirements one is led to a specific, gauge-invariant definition that retains the familiar properties of an electromagnetic field. An electromagnetic vector potential is constructed whose curl (exterior derivative) in any gauge gives the electromagnetic field tensor. As is required, this vector potential transforms at most by a pure gradient under arbitrary SU(2)xU(1) gauge transformations. The flux of the magnetic field is expressed as a gauge-invariant line integral. Curiously, this provides a definition for magnetic flux in cases where the spatial region with broken symmetry is not simply connected and the magnetic field itself is not everywhere defined.
Reducible Quantum Electrodynamics. I. The Quantum Dimension of the Electromagnetic Field
Jan Naudts
2015-05-30T23:59:59.000Z
In absence of currents and charges the quantized electromagnetic field can be described by wave functions which for each individual wave vector are normalized to one. The resulting formalism involves reducible representations of the Canonical Commutation Relations. The corresponding paradigm is a space-time filled with two-dimensional quantum harmonic oscillators. Mathematically, this is equivalent with two additional dimensions penetrated by the electromagnetic waves.
Novokhatski, Alexander; /SLAC; Sullivan, Michael; /SLAC; ,
2010-09-14T23:59:59.000Z
We discuss the feasibility of an application of an implicit finite-difference approximation to calculate the fields of a relativistic bunch moving with no restriction inside a vacuum chamber. We assume that a bunch trajectory is not straight but is inside a vacuum chamber or its branch. The bunch can be deflected by the fields of bending magnets. The bunch can be short enough to produce coherent synchrotron radiation (CSR). Accelerator physicists believe that electromagnetic phenomena of charged beams are governed by Maxwell's equations together with Newton's equations for particle dynamics. To understand the behavior of the beams and radiated fields we just need to find a solution to these equations for the case, which can fully describe the real accelerator environment. So, at first we make a model, which contains all the necessary components, but at the same time can be easily 'inserts' into the equations. Sometimes, it is possible to find analytical solutions, but usually they are only work for one-dimensional cases and rarer for two-dimension cases. To find a solution in general we may transform the equations into a equivalent finite-difference form and solve them using computers. We can find a lot of finite-difference schemes, which approximate Maxwell's equations since the first one that was published in 1966. Most of them are so called explicit schemes. That means that the value of the field at the new time step is calculated only by the field values at the previous time step. Stability conditions for these schemes do not allow a time step to be greater than or equal to a space (mesh) step. This limitation brings an additional troublesome effect for short wavelengths compared a mesh step. We state that this effect works like a frequency dispersion media, which is 'hidden' in the finite-difference equation.
MEASUREMENT AND ANALYSIS OF ELECTROMAGNETIC FIELDS FROM TRAMS, TRAINS AND HYBRID CARS
Halgamuge, Malka N.
of electric and magnetic fields emitted from Australian trams, trains and hybrid cars were investigated cars are now electrically operated, therefore emitting less CO2 and less pollution into the environmentMEASUREMENT AND ANALYSIS OF ELECTROMAGNETIC FIELDS FROM TRAMS, TRAINS AND HYBRID CARS Malka N
Haddadi, Hamed
Exposure assessment of Electromagnetic Fields from Wireless Computer Networks (Wi-Fi); Phase 1 networks, the most popular Wi-Fi devices used in the schools were identified. The regulatory standards bisecting the screen and keyboard. The maximum electric field strength recorded at 1 m varied from 719 mVm-1
High-frequency electric field measurement using a toroidal antenna
Lee, Ki Ha (Lafayette, CA)
2002-01-01T23:59:59.000Z
A simple and compact method and apparatus for detecting high frequency electric fields, particularly in the frequency range of 1 MHz to 100 MHz, uses a compact toroidal antenna. For typical geophysical applications the sensor will be used to detect electric fields for a wide range of spectrum starting from about 1 MHz, in particular in the frequency range between 1 to 100 MHz, to detect small objects in the upper few meters of the ground. Time-varying magnetic fields associated with time-varying electric fields induce an emf (voltage) in a toroidal coil. The electric field at the center of (and perpendicular to the plane of) the toroid is shown to be linearly related to this induced voltage. By measuring the voltage across a toroidal coil one can easily and accurately determine the electric field.
J. -B. Gros; U. Kuhl; O. Legrand; F. Mortessagne
2015-09-22T23:59:59.000Z
The effective Hamiltonian formalism is extended to vectorial electromagnetic waves in order to describe statistical properties of the field in reverberation chambers. The latter are commonly used in electromagnetic compatibility tests. As a first step, the distribution of wave intensities in chaotic systems with varying opening in the weak coupling limit for scalar quantum waves is derived by means of random matrix theory. In this limit the only parameters are the modal overlap and the number of open channels. Using the extended effective Hamiltonian, we describe the intensity statistics of the vectorial electromagnetic eigenmodes of lossy reverberation chambers. Finally, the typical quantity of interest in such chambers, namely, the distribution of the electromagnetic response, is discussed. By determining the distribution of the phase rigidity - describing the coupling to the environment - using random matrix numerical data, we find good agreement between the theoretical prediction and numerical calculations of the response.
Sergio Cordero; Eduardo Nahmad-Achar; Ramón López-Peña; Octavio Castaños
2015-08-28T23:59:59.000Z
A system of $N_a$ atoms of $n$-levels interacting dipolarly with $\\ell$ modes of electromagnetic field is considered. The energy surface of the system is constructed from the direct product of the coherent states of U$(n)$ in the totally symmetric representation for the matter times the $\\ell$ coherent states of the electromagnetic field. A variational analysis shows that the collective region is divided into $\\ell$ zones, inside each of which only one mode of the electromagnetic field contributes to the ground state. In consequence, the polychromatic phase diagram for the ground state naturally divides itself into monochromatic regions. For the case of $3$-level atoms in the $\\Xi$-configuration in the presence of $2$ modes, the variational calculation is compared with the exact quantum solution showing that both are in agreement.
Cummer, Steven A.
strokes that do and do not generate detectable ionospheric perturbations. Citation: Cheng, Z., S. A electromagnetic pulses Zhenggang Cheng,1 Steven A. Cummer,1 Han-Tzong Su,2 and Rue-Ron Hsu2 Received 10 May 2006
High-frequency electromagnetic properties of epitaxial Bi2FeCrO6 thin films grown by pulsed laser on the electromagnetic (EM) properties in high-frequency domain (HF) of multiferroic Bi2FeCrO6 (BFCO) thin films. The films were epitaxially grown on SrTiO3 substrates by pulsed laser ablation. Typical 50 nm-thick BFCO
Guiding and collimating fast electron beam by the quasi-static electromagnetic field array
Wang, J. [Physics Department, Fudan University, Shanghai 210433 (China); Science and Technology on Plasma Physics Laboratory, Mianyang 621900 (China); Zhao, Z. Q.; He, W. H.; Dong, K. G.; Wu, Y. C.; Zhu, B.; Zhang, T. K.; Zhang, B.; Zhang, Z. M.; Gu, Y. Q., E-mail: yqgu@caep.ac.cn [Science and Technology on Plasma Physics Laboratory, Mianyang 621900 (China); Cao, L. H. [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)
2014-10-15T23:59:59.000Z
A guidance and collimation scheme for fast electron beam in a traverse periodic quasi-static electromagnetic field array is proposed with the semi-analytic method and the particle-in-cell simulation. The sheath electric fields on the surfaces of nanowires and the magnetic fields around the nanowires form a traverse periodic quasi-static electromagnetic field array. Therefore, most of the fast electrons are confined at the nanowire surfaces and transport forward. More importantly, due to the divergent property of the beams, the magnitudes of the generated fields decrease with the target depth. The lateral momenta of the electrons convert into the forward momenta through Lorenz force, and they cannot recover their initial values. Therefore, the fast electrons can be guided and collimated efficiently in the gaps between the nanowires. In our particle-in-cell simulations, the observed guiding efficiency exceeds 80% compared with the reference target.
Controlling Electromagnetic Fields at Boundaries of Arbitrary Geometries
Teo, Jonathon Yi Han; Molardi, Carlo; Genevet, Patrice
2015-01-01T23:59:59.000Z
Rapid developments in the emerging field of stretchable and conformable photonics necessitate analytical expressions for boundary conditions at metasurfaces of arbitrary geometries. Here, we introduce the concept of conformal boundary optics: a design theory that determines the optical response for designer input and output fields at such interfaces. Given any object, we can realise coatings to achieve exotic effects like optical illusions and anomalous diffraction behaviour. This approach is relevant to a broad range of applications from conventional refractive optics to the design of the next-generation of wearable optical components. This concept can be generalized to other fields of research where designer interfaces with nontrivial geometries are encountered.
Hakala, J. Alexandra [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Stanchina, William [Univ. of Pittsburgh, PA (United States); National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Soong, Yee [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Hedges, Sheila [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)
2011-01-01T23:59:59.000Z
Development of in situ electromagnetic (EM) retorting technologies and design of specific EM well logging tools requires an understanding of various process parameters (applied frequency, mineral phases present, water content, organic content and temperature) on oil shale dielectric properties. In this literature review on oil shale dielectric properties, we found that at low temperatures (<200° C) and constant oil shale grade, both the relative dielectric constant (?') and imaginary permittivity (?'') decrease with increased frequency and remain constant at higher frequencies. At low temperature and constant frequency, ?' decreases or remains constant with oil shale grade, while ?'' increases or shows no trend with oil shale grade. At higher temperatures (>200º C) and constant frequency, epsilon' generally increases with temperature regardless of grade while ?'' fluctuates. At these temperatures, maximum values for both ?' and ?'' differ based upon oil shale grade. Formation fluids, mineral-bound water, and oil shale varve geometry also affect measured dielectric properties. This review presents and synthesizes prior work on the influence of applied frequency, oil shale grade, water, and temperature on the dielectric properties of oil shales that can aid in the future development of frequency- and temperature-specific in situ retorting technologies and oil shale grade assay tools.
Jeong, Jaehoon
2009-05-15T23:59:59.000Z
and multiconductor transmission lines. The method is extended to represent the general solution to Maxwell’s differential equations in vector matrix form. It is shown that, given the electromagnetic field and boundary conditions at a given instant in time, the free...
Coupling of electrons to the electromagnetic field in a localized basis
Allen, Roland E.
2008-01-01T23:59:59.000Z
A simple formula is obtained for coupling electrons in a complex system to the electromagnetic field. It includes the effect of intra-atomic excitations and nuclear motion, and can be applied in, e.g., first-principles-based simulations...
Exact analytical expression for the electromagnetic field in a focused laser beam or pulse
Alexander M. Fedotov; Konstantin Yu. Korolev; Maxim V. Legkov
2007-05-18T23:59:59.000Z
We present a new class of exact nonsingular solutions for the Maxwell equations in vacuum, which describe the electromagnetic field of the counterpropagating focused laser beams and the subperiod focused laser pulse. These solutions are derived by the use of a modification of the "complex source method", investigated and visualized.
Coupling of electrons to the electromagnetic field in a localized basis
Allen, Roland E.
2008-01-01T23:59:59.000Z
A simple formula is obtained for coupling electrons in a complex system to the electromagnetic field. It includes the effect of intra-atomic excitations and nuclear motion, and can be applied in, e.g., first-principles-based simulations...
Full-wave Electromagnetic Field Simulations of Lower Hybrid Waves in Tokamaks
Wright, John C.
Full-wave Electromagnetic Field Simulations of Lower Hybrid Waves in Tokamaks J. C. Wright , P. T, VA, USA Abstract. The most common method for treating wave propagation in tokamaks in the lower of 2D and 3D plasma inhomogeneity effects on wave propagation, the approach neglects important effects
Alexander G. Kyriakos
2004-07-09T23:59:59.000Z
The present paper is the continuity of the previous papers "Non-linear field theory" I and II. Here on the basis of the electromagnetic representation of Dirac's electron theory we consider the geometrical distribution of the electromagnetic fields of the electron-positron. This gives the posibility to obtain the explanation and solution of many fundamental problems of the QED.
Research Profile Research activities of the Electromagnetic Field Theory Group
Sandoghdar, Vahid
with the sealing of high power microwaves. In cooperation with Bosh and Sie- mens, a new sealing technique antennas will be applicable in sensor technology, near-field optical microscopy or spectros- copy
A study of electromagnetic fields in horn antennas containing two eielectrics
Quddus, Mohammad Abdul
1960-01-01T23:59:59.000Z
A STUDY OF ELECTROMAGNETIC FIELDS IN HORN ANTENNAS CONTAINING TWO DIELECTRICS A Thesis by MD. ABDUL QUDDUS Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements... dielectric has been made by Barrow and Chu. The design of optimum air- 2 filled horn has been studied by Barrow and Chu and by Braun. Barton 3 13 11 and Rhodes4 have worked on the radiation pattern, and the gain of the electromagnetic horns has been...
On the Electrodynamics of Moving Permanent Dipoles in External Electromagnetic Fields
Mansuripur, Masud
2014-01-01T23:59:59.000Z
The classical theory of electrodynamics is built upon Maxwell's equations and the concepts of electromagnetic field, force, energy and momentum, which are intimately tied together by Poynting's theorem and the Lorentz force law. Whereas Maxwell's macroscopic equations relate the electric and magnetic fields to their material sources (i.e., charge, current, polarization and magnetization), Poynting's theorem governs the flow of electromagnetic energy and its exchange between fields and material media, while the Lorentz law regulates the back-and-forth transfer of momentum between the media and the fields. The close association of momentum with energy thus demands that the Poynting theorem and the Lorentz law remain consistent with each other, while, at the same time, ensuring compliance with the conservation laws of energy, linear momentum, and angular momentum. This paper shows how a consistent application of the aforementioned laws of electrodynamics to moving permanent dipoles (both electric and magnetic) b...
On the control by electromagnetic fields of quantum systems with infinite dimensional Hilbert space
Elie Assémat; Thomas Chambrion; Dominique Sugny
2014-12-12T23:59:59.000Z
We analyze the control by electromagnetic fields of quantum systems with infinite dimensional Hilbert space and a discrete spectrum. Based on recent mathematical results, we rigorously show under which conditions such a system can be approximated in a finite dimensional Hilbert space. For a given threshold error, we estimate this finite dimension in terms of the used control field. As illustrative examples, we consider the cases of a rigid rotor and of a harmonic oscillator.
Interacting Scalar and Electromagnetic Fields in $f(R,\\,T)$ Theory of Gravity
Bijan Saha
2014-10-07T23:59:59.000Z
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.
Full Action for an Electromagnetic Field with Electrical and Magnetic Charges
S. S. Serova; S. A. Serov
2010-09-25T23:59:59.000Z
The paper offers the full action for an electromagnetic field with electrical and magnetic charges; Feynman laws are formulated for the calculation of the interaction cross-sections for electrically and magnetically charged particles on the base of offered action within relativistic quantum field theory. Derived with formulated Feynman rules cross-section of the interaction between an elementary particle with magnetic charge and an elementary particle with electrical charge proves to be equal zero.
Complex representation theory of the electromagnetic field Andreas Aste
Aste, Andreas
-component Majorana field equations. An important difference between the Dirac equation and the Dirac form of Maxwell matrices ~1, ~2, and ~3 defined by the help of the totally antisymmetric tensor in three dimensions , k = 1, 2, 3) t = ~kk (13) or, defining matrices Âµ by 0 = Id 3, where Id 3 denotes the 3 Ã? 3
Loures, Cristian Redondo; Biancalana, Fabio
2015-01-01T23:59:59.000Z
Starting from the infinite-dimensional Ikeda map, we derive an extended temporal Lugiato-Lefever equation that may account for the effects of the conjugate electromagnetic fields (also called `negative frequency fields'). In the presence of nonlinearity in a ring cavity, these fields lead to new forms of modulational instability and resonant radiations. Numerical simulations based on the new extended Lugiato-Lefever model show that the negative-frequency resonant radiations emitted by ultrashort cavity solitons can impact Kerr frequency comb formation in externally pumped temporal optical cavities of small size. Our theory is very general, is not based on the slowly-varying envelope approximation, and the predictions are relevant to all kinds of resonators, such as fiber loops, microrings and microtoroids.
Detection of electromagnetic waves using MEMS antennas
Lavrik, Nickolay V [ORNL] [ORNL; Tobin, [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Bowland, Landon T [ORNL] [ORNL
2011-01-01T23:59:59.000Z
We describe the design, fabrication and characterization of simple micromechanical structures that are capable of sensing static electric time varying electromagnetic fields. Time varying electric field sensing is usually achieved using an electromagnetic antenna and a receiver. However, these antenna-based approaches do not exhibit high sensitivity over a broad frequency (or wavelength) range. An important aspect of the present work is that, in contrast to traditional antennas, the dimensions of these micromechanical oscillators can be much smaller than the wavelength of the electromagnetic wave. We characterized the fabricated micromechanical oscillators by measuring their responses to time varying electric and electromagnetic fields.
Electromagnetically superconducting phase of QCD vacuum induced by strong magnetic field
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
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.
Electromagnetic fields in nonuniform disk-loaded waveguides
Ayzatsky, M I
2015-01-01T23:59:59.000Z
On the base of general approach we obtain some results that can be useful in the process of tuning of nonunifrom disc-loaded waveguides. Our consideration has shown that simple values that characterize the detuning of the cells can be introduced only for the disc-loaded waveguide with parameters that change very slow. In general case it is needed to conduct full numerical simulation of specific disc-loaded waveguide and obtain all necessary coupling coefficients. After that one can start the tuning process on the base of bead-pull field distribution measurements.
Two photon amplitude of partially coherent partially entangled electromagnetic fields
Miguel Angel Olvera; Sonja Franke-Arnold
2015-07-30T23:59:59.000Z
The development of efficient protocols for pure and mixed states preparation is challenging task. Most of the theory of quantum information applications has been developed for fully coherent or completely incoherent light. However, in many situations of interest partially coherent light has been proved to be a more robust model of radiation. In this paper the underpinning theory of two photon amplitude functions for down-converted fields with partially coherent pump beams is investigated. By using the generalised Siegert relations and the coherent mode representation of the cross spectral density matrix the two photon amplitude is fully characterised for partially coherent beams. A number of correlation properties from modern coherence theory are demonstrated to be preserved under parametric down-conversion. Based on the generalised Siegert relations and the Cauchy-Schwarz inequality a measure of entanglement for the two photon amplitude is proposed. Upper bounds for this measure are found in terms of the \\emph{golden ratio} for maximally entangled states. Two inequalities are derived for the two photon amplitude for which there exist a transition zone from super-Poisson statistics to sub-Poisson statistics for down-converted partially coherent fields.
8.07 Electromagnetism II, Fall 2002
Zwiebach, Barton
Survey of basic electromagnetic phenomena: electrostatics, magnetostatics; electromagnetic properties of matter. Time-dependent electromagnetic fields and Maxwell's equations. Electromagnetic waves, emission, absorption, ...
Gillani, S. S. A.; Shah, H. A. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Tsintsadze, N. L. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Institute of Physics, Tbilisi 380077 (Georgia); Razzaq, M. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan)
2010-08-15T23:59:59.000Z
It is shown that the interaction of the superstrong laser radiation with an isotropic plasma leads to the generation of low frequency electromagnetic (EM) waves and in particular a quasistationary magnetic field. When the relativistic circularly polarized transverse EM wave propagates along z-axis, it creates a ponderomotive force, which affects the motion of particles along the direction of its propagation. On the other hand, motion of the particles across the direction of propagation is defined by the ponderomotive potential. The dispersion relation for the transverse EM wave using a special distribution function, which has an anisotropic form, is derived. The dispersion relation is subsequently investigated for a number of special cases. In general, it is shown that the growth rate of the EM wave strongly depends upon its intensity.
Christo I. Christov
2011-03-06T23:59:59.000Z
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.
Hammond, R.T. [Physics Department, North Dakota State University, Fargo, North Dakota 58105 (United States)] [Physics Department, North Dakota State University, Fargo, North Dakota 58105 (United States); Davis, J.; Bobb, L. [Naval Air Warfare Center, Code 4556, Mail Stop 2, Patuxent River, Maryland 20670 (United States)] [Naval Air Warfare Center, Code 4556, Mail Stop 2, Patuxent River, Maryland 20670 (United States)
1997-02-01T23:59:59.000Z
The reflection, transmission, and absorption coefficients are derived for long-wavelength electromagnetic radiation propagating through a medium that exhibits a Gaussian conductivity. It is shown that, under certain circumstances, this applies to the ionosphere. The effects of different peak conductivities and Gaussian widths are examined, and a useful form for calculating transmission and reflection coefficients is presented. {copyright} {ital 1997 American Institute of Physics.}
Kensuke Homma
2009-11-30T23:59:59.000Z
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.
Saleem, H. [National Centre for Physics (NCP), Quaid-i-Azam University Campus, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Ahmad, Ali [Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad (Pakistan); Khan, S. A. [National Centre for Physics (NCP), Quaid-i-Azam University Campus, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Department of Physics, Government College Bagh AJK (Pakistan)
2008-09-15T23:59:59.000Z
A coupled linear dispersion relation for the basic electrostatic and electromagnetic waves in the ultracold nonuniform magnetized dense plasmas has been obtained which interestingly is analogous to the classical case. The scales of macroscopic phenomena and the interparticle quantum interactions are discussed. It is important to point out that hydrodynamic models cannot take into account strong quantum effects and they are not applicable to very dense plasmas. The analysis is presented with applications to dense plasmas which are relevant to both laboratory and astrophysical environments.
Radio frequency sheaths in an oblique magnetic field
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Myra, James R.; D'Ippolito, Daniel A.
2015-06-01T23:59:59.000Z
The physics of radio-frequency (rf) sheaths near a conducting surface is studied for plasmas immersed in a magnetic field that makes an oblique angle ? with the surface. A set of one-dimensional equations is developed that describe the dynamics of the time-dependent magnetic presheath and non-neutral Debye sheath. The model employs Maxwell-Boltzmann electrons, and the magnetization and mobility of the ions is determined by the magnetic field strength, and wave frequency, respectively. The angle, ? assumed to be large enough to insure an electron-poor sheath, is otherwise arbitrary. Concentrating on the ion-cyclotron range of frequencies, the equations are solved numericallymore »to obtain the rectified (dc) voltage, the rf voltage across the sheath and the rf current flowing through the sheath. As an application of this model, the sheath voltage-current relation is used to obtain the rf sheath impedance, which in turn gives an rf sheath boundary condition for the electric field at the sheath-plasma interface that can be used in rf wave codes. In general the impedance has both resistive and capacitive contributions, and generalizes previous sheath boundary condition models. The resistive part contributes to parasitic power dissipation at the wall.« less
Electromagnetic quasinormal modes of D-dimensional black holes II
A. López-Ortega
2007-06-20T23:59:59.000Z
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.
Non-Markovian master equation for a system of Fermions interacting with an electromagnetic field
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
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.
Hur, Min Sup
2009-01-01T23:59:59.000Z
813 Guiding of an electromagnetic pulse in a plasma immersedGuiding of an electromagnetic pulse in a plasma immersed inof guiding an electromagnetic pulse. The scheme consists of
Radio frequency accelerating cavity having slotted irises for damping certain electromagnetic modes
Palmer, R.B.
1991-05-21T23:59:59.000Z
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.
Spin Wave Storage using Chirped Control Fields in Atomic Frequency Comb based Quantum Memory
Ji?í Miná?; Nicolas Sangouard; Mikael Afzelius; Hugues de Riedmatten; Nicolas Gisin
2010-08-13T23:59:59.000Z
It has been shown that an inhomogeneously broadened optical transition shaped into an atomic frequency comb can store a large number of temporal modes of the electromagnetic field at the single photon level without the need to increase the optical depth of the storage material. The readout of light modes is made efficient thanks to the rephasing of the optical-wavelength coherence similarly to photon echo-type techniques and the re-emission time is given by the comb structure. For on-demand readout and long storage times, two control fields are used to transfer back and forth the optical coherence into a spin wave. Here, we present a detailed analysis of the spin wave storage based on chirped adiabatic control fields. In particular, we verify that chirped fields require significantly weaker intensities than $\\pi$-pulses. The price to pay is a reduction of the multimode storage capacity that we quantify for realistic material parameters associated with solids doped with rare-earth-metal ions.
Mei Xiaochun
2008-04-19T23:59:59.000Z
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.
Ewing, P.D.; Korsah, K. [Oak Ridge National Lab., TN (United States)
1994-04-01T23:59:59.000Z
This report discusses the development of the technical basis for the control of upsets and malfunctions in safety-related instrumentation and control (I&C) systems caused by electromagnetic and radio-frequency interference (EMI/RFI) and power surges. The research was performed at the Oak Ridge National Laboratory (ORNL) and was sponsored by the USNRC Office of Nuclear Regulatory Research (RES). The motivation for research stems from the safety-related issues that need to be addressed with the application of advanced I&C systems to nuclear power plants. Development of the technical basis centered 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 known to be the source(s) of EMI/RFI and power surges. First, good EMC design and installation practices need to be established to control the impact of interference sources on nearby circuits and systems. These EMC good practices include circuit layouts, terminations, filtering, grounding, bonding, shielding, and adequate physical separation. Second, an EMI/RFI test and evaluation program needs to be established to outline the tests to be performed, the associated test methods to be followed, and carefully formulated acceptance criteria based on the intended environment to ensure that the circuit or system under test meets the recommended guidelines. Third, a program needs to be developed to perform confirmatory tests and evaluate the surge withstand capability (SWC) and of I&C equipment connected to or installed in the vicinity of power circuits within the nuclear power plant. By following these three steps, the design and operability of safety-related I&C systems against EMI/RFI and power surges can be evaluated, acceptance criteria can be developed, and appropriate regulatory guidance can be provided.
Electromagnetic partner of the gravitational signal during accretion onto black holes
Juan Carlos Degollado; Victor Gualajara; Claudia Moreno; Darío Núñez
2014-10-21T23:59:59.000Z
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.
Neutrino spin oscillations in matter under the influence of gravitational and electromagnetic fields
Dvornikov, Maxim, E-mail: maxim.dvornikov@usp.br [Institute of Physics, University of São Paulo, CP 66318, CEP 05315-970 São Paulo, SP (Brazil)
2013-06-01T23:59:59.000Z
We derive the new quasi-classical equation for the description of the spin evolution of a neutrino propagating in a curved space-time and interacting with a background matter and an external electromagnetic field. This equation is used to analyze neutrino spin oscillations in these external backgrounds. We obtain the effective Hamiltonian and the transition probability for oscillations of neutrinos when they move in the vicinity of a rotating black hole, surrounded by an accretion disk, and interact with an external magnetic field. The appearance of new resonances in neutrino spin oscillations in this system is considered. The approximate treatment of spin oscillations of radially propagating ultra high energy neutrinos is developed. We also discuss the applications of our results to the description of neutrino spin oscillations in realistic astrophysical media.
Fitzpatrick, Richard
Error-field induced electromagnetic torques in a large aspect-ratio, low- , weakly shaped tokamak-ratio tokamaks Phys. Plasmas 17, 122504 (2010); 10.1063/1.3526611 A nonideal error-field response model for strongly shaped tokamak plasmas Phys. Plasmas 17, 112502 (2010); 10.1063/1.3504227 Modeling the effect
Low-cost electromagnetic tagging : design and implementation
Fletcher, Richard R. (Richard Ribon)
2002-01-01T23:59:59.000Z
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 ...
Long-term monitoring of ULF electromagnetic fields at Parkfield, CA
Kappler, K.N.; Morrison, H.F.; Egbert, G.D.
2009-08-01T23:59:59.000Z
Electric and magnetic fields in the (10{sup -4}-1.0) Hz band were monitored at two sites adjacent to the San Andreas Fault near Parkfield and Hollister, California from 1995 to present. A data window [2002-2005], enclosing the September 28, 2004 M6 Parkfield earthquake, was analyzed to determine if anomalous electric or magnetic fields, or changes in ground conductivity, occurred before the earthquake. The data were edited, removing intervals of instrument malfunction leaving 875 days in the four-year period. Frequent, spike-like disturbances were common, but were not more frequent around the time of the earthquake; these were removed before subsequent processing. Signal to noise amplitude spectra, estimated via magnetotelluric processing showed the behavior of the ULF fields to be remarkably constant over the period of analysis. These first-order plots make clear that most of the recorded energy is coherent over the spatial extent of the array. Three main statistical techniques were employed to separate local anomalous electrical or magnetic fields from the dominant coherent natural fields: transfer function estimates between components at each site were employed to subtract the dominant field, and look deeper at the 'residual' fields; the data were decomposed into principal components to identify the dominant coherent array modes; and the technique of canonical coherences was employed to distinguish anomalous fields which are spatially broad from anomalies which occur at a single site only, and furthermore to distinguish anomalies which are present in both the electric and magnetic fields from those which are present in only one field type. Standard remote reference apparent resistivity estimates were generated daily at Parkfield. A significant seasonal component of variability was observed suggesting local distortion due to variations in near surface resistance. In all cases, high levels of sensitivity to subtle electromagnetic effects were demonstrated, but no effects which can be reasonably characterized as precursors to the Parkfield earthquake were found.
Jerome Petri
2015-04-01T23:59:59.000Z
The magnetic field topology in the surrounding of neutron stars is one of the key questions in pulsar magnetospheric physics. A very extensive literature exists about the assumption of a dipolar magnetic field but very little progress has been made in attempts to include multipolar components in a self-consistent way. In this paper, we study the effect of multipolar electromagnetic fields anchored in the star. We give exact analytical solutions in closed form for any order $l$ and apply them to the retarded point quadrupole ($l=2$), hexapole ($l=3$) and octopole ($l=4$), a generalization of the retarded point dipole ($l=1$). We also compare the Poynting flux from each multipole and show that the spin down luminosity depends on the ratio $R/r_{\\rm L}$, $R$ being the neutron star radius and $r_{\\rm L}$ the light-cylinder radius. Therefore the braking index also depends on $R/r_{\\rm L}$. As such multipole fields possess very different topology, most importantly smaller length scales compared to the dipolar field, especially close to the neutron star, we investigate the deformation of the polar caps induced by these multipolar fields. Such fields could have a strong impact on the interpretation of the pulsed radio emission suspected to emanate from these polar caps as well as on the inferred geometry deduced from the high-energy light-curve fitting and on the magnetic field strength. Discrepancies between the two-pole caustic model and our new multipole-caustic model are emphasized with the quadrupole field. To this respect, we demonstrate that working with only a dipole field can be very misleading.
Spinor-Unit Field Representation of Electromagnetism Applied to a Model Inflationary Cosmology
Patrick L. Nash
2015-04-14T23:59:59.000Z
The new spinor-unit field representation of the electromagnetism \\cite{Nash2010} (with quark and lepton sources) is integrated via minimal coupling with standard Einstein gravitation, to formulate a Lagrangian model of the very early universe. The solution of the coupled Euler-Lagrange field equations yields a scale factor $a(t)$ (comoving coordinates) that initially exponentially increases $N$ e-folds from $a(0) \\approx 0$ to $a_{1} = a(0) {e}^{N} $ ($N$ = 60 is illustrated), then exponentially decreases, then exponentially increases to $a_{1}$, and so on almost periodically. (Oscillatory cosmological models are not knew, and have been derived from string theory and loop quantum gravity.) It is not known if the scale factor escapes this periodic trap. This model is noteworthy in several respects: $\\{1\\}$ All fundamental fields other than gravity are realized by spinor fields. $\\{2\\}$ A plausible connection between the \\emph{unit} field $\\mathbf{u}$ and the generalization of the photon wave function with a form of Dark Energy is described, and a simple natural scenario is outlined that allocates a fraction of the total energy of the Universe to this form of Dark Energy. $\\{3\\}$ A solution of an analog of the pure Einstein-Maxwell equations is found. This approach is in contrast with the method followed to obtain a solution of the well known Friedmann model of a radiation-dominated universe.
Blocksom, R.; Bucholz, R.
1991-01-01T23:59:59.000Z
This report documents the results of tests to record and analyze the characteristic response of three photonic Electric field, E-field sensors to simulated Electromagnetic Pulse (EMP), compared to that of a reference metallic sensor. Work was performed under Naval Research Laboratory (NRL) contract N00014-89-C-2033, sponsored by Naval Air Systems Command (NAVAIR). Tasks included: (1) selection of candidate sensors capable of measuring the E-field content (intensity and frequency spectrum) of simulated EMP phenomena generated by the Horizontally Polarized Dipole (HPD) EMP simulator at the Naval Air Test Center (NATC), Patuxent River, MD; (2) liaison with sensor designers, NATC personnel, and others as necessary to delineate test requirements and constraints; (3) development of a sensor test plan; (4) sensor tests in the HPD EMP simulation; (5) analysis of the test data; and (6) generation of the Test Report. The activities discussed herein were performed during the period of March 1990-January 1991. Since 1985, the Naval Research Laboratory (NRL) and ARC Professional Services Group Defense Systems Division (ARC) have conducted an RD effort to produce a prototype fiber optic sensor system for application to EMP field measurement. The work was sponsored under Fleet Aircraft Assessment for Navy Testing and Analysis for EMP Limitation (FAANTAEL) project managed by NAVAIR Electromagnetic Environmental Effects (E3) Branch, AIR-5161.
Electromagnetic Zero Point Field as Active Energy Source in the Intergalactic Medium
Alfonso Rueda; Hiroki Sunahata; Bernhard Haisch
1999-06-16T23:59:59.000Z
For over twenty years the possibility that the electromagnetic zero point field (ZPF) may actively accelerate electromagnetically interacting particles in regions of extremely low particle density (as those extant in intergalactic space (IGS) with n energies. The recent finding by the AGASA collaboration (Phys. Rev. Lett., 81, 1163, 1998) that the CR energy spectrum does not display any signs of the Greisen-Zatsepin-Kuzmin cut-off (that should be present if these CR particles were indeed generated in localized ultrahigh energies CR sources, as e.g., quasars and other highly active galactic nuclei), may indicate the need for an acceleration mechanism that is distributed throughout IGS as is the case with the ZPF. Other unexplained phenomena that receive an explanation from this mechanism are the generation of X-ray and gamma-ray backgrounds and the existence of Cosmic Voids. However recently, a statistical mechanics kind of challenge to the classical (not the quantum) version of the zero-point acceleration mechanism has been posed (de la Pena and Cetto, The Quantum Dice, 1996). Here we briefly examine the consequences of this challenge and a prospective resolution.
Detection of electromagnetic waves using charged MEMS structures
Datskos, Panos G [ORNL; Lavrik, Nickolay V [ORNL; Tobin, Jacob D [ORNL; Bowland, Landon T [ORNL
2012-01-01T23:59:59.000Z
We describe micromechanical structures that are capable of sensing both electrostatic fields and electromagnetic fields over a wide frequency range. Typically, sensing of electromagnetic waves is achieved with electrically conducting antennas, which despite the many advantages do not exhibit high sensitivity over a broad frequency range. An important aspect of our present work is that, in contrast to traditional antennas, the dimensions of micromechanical oscillators sensitive to electromagnetic waves can be much smaller than the wavelength. We characterized the micromechanical oscillators and measured responses to electric fields and estimated the performance limits by evaluating the signal-to-noise ratio theoretically and experimentally.
Kartashov, I. N., E-mail: igorkartashov@mail.ru; Kuzelev, M. V., E-mail: kuzelev@mail.ru [Moscow State University, Physics Department (Russian Federation)
2014-12-15T23:59:59.000Z
Electromagnetic modes of a plasma waveguide with a nonsimply connected cross section in an external magnetic field are investigated. The existence of quasi-TEM modes in a finite-strength magnetic field is demonstrated. It is shown that, in the limits of infinitely strong and zero magnetic fields, this mode transforms into a true TEM mode. The possibility of excitation of such modes by an electron beam in the regime of the anomalous Doppler effect is analyzed.
Asymptotic Entanglement Dynamics Phase Diagrams for Two Electromagnetic Field Modes in a Cavity
R. C. Drumond; L. A. M. Souza; M. Terra Cunha
2010-10-20T23:59:59.000Z
We investigate theoretically an open dynamics for two modes of electromagnetic field inside a microwave cavity. The dynamics is Markovian and determined by two types of reservoirs: the "natural" reservoirs due to dissipation and temperature of the cavity, and an engineered one, provided by a stream of atoms passing trough the cavity, as devised in [Pielawa \\emph{et al.} \\emph{Phys. Rev. Lett.} \\textbf{98}, 240401 (2007)]. We found that, depending on the reservoir parameters, the system can have distinct "phases" for the asymptotic entanglement dynamics: it can disentangle at finite time or it can have persistent entanglement for large times, with the transition between them characterized by the possibility of asymptotical disentanglement. Incidentally, we also discuss the effects of dissipation on the scheme proposed in the above reference for generation of entangled states.
Roeoesli, Martin [Institute of Social and Preventive Medicine, Department of Social and Preventive Medicine, University of Bern, Finkenhubelweg 11, CH-3012 Bern (Switzerland)], E-mail: Roeoesli@ispm.unibe.ch
2008-06-15T23:59:59.000Z
This article is a systematic review of whether everyday exposure to radiofrequency electromagnetic field (RF-EMF) causes symptoms, and whether some individuals are able to detect low-level RF-EMF (below the ICNIRP [International Commission on Non-Ionizing Radiation Protection] guidelines). Peer-reviewed articles published before August 2007 were identified by means of a systematic literature search. Meta-analytic techniques were used to pool the results from studies investigating the ability to discriminate active from sham RF-EMF exposure. RF-EMF discrimination was investigated in seven studies including a total of 182 self-declared electromagnetic hypersensitive (EHS) individuals and 332 non-EHS individuals. The pooled correct field detection rate was 4.2% better than expected by chance (95% CI: -2.1 to 10.5). There was no evidence that EHS individuals could detect presence or absence of RF-EMF better than other persons. There was little evidence that short-term exposure to a mobile phone or base station causes symptoms based on the results of eight randomized trials investigating 194 EHS and 346 non-EHS individuals in a laboratory. Some of the trials provided evidence for the occurrence of nocebo effects. In population based studies an association between symptoms and exposure to RF-EMF in the everyday environment was repeatedly observed. This review showed that the large majority of individuals who claims to be able to detect low level RF-EMF are not able to do so under double-blind conditions. If such individuals exist, they represent a small minority and have not been identified yet. The available observational studies do not allow differentiating between biophysical from EMF and nocebo effects.
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
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.
Stepanov, Andrei G; Bonacina, Luigi; Wolf, Jean-Pierre; Hauri, Christoph P
2014-01-01T23:59:59.000Z
We present a numerical parametric study of single-cycle electromagnetic pulse generation in a DAST/SiO2 multilayer structure via collinear optical rectification of 800 nm femtosecond laser pulses. It is shown that modifications of the thicknesses of the DAST and SiO2 layers allow tuning of the average frequency of the generated THz pulses in the frequency range from 3 to 6 THz. The laser-to-THz energy conversion efficiency in the proposed structures is compared with that in a bulk DAST crystal and a quasi-phase-matching periodically poled DAST crystal and shows significant enhancement.
Wellington da Cruz
1997-10-16T23:59:59.000Z
The technique of functional integration over velocities is applied to the calculation of the propagator of a spinning particle with and without anomalous magnetic moment. A representation for the spin factor is obtained in this context for the particle in a constant electromagnetic field. As a by-product, we also obtain a Schwinger representation for the first case.
B. V. Gisin
2015-08-20T23:59:59.000Z
The field of a traveling circularly polarized electromagnetic wave and a constant magnetic field localizes fermions perpendicularly to propagation of the wave in the cross section of the order of the wavelength. Unusual exact solutions of the Dirac equation correspond to this localization. Except to routine use of thin fermion beams it can be suitable for alternative measurements of the g - factor. Details and peculiarities of the solutions in application to the measurements are considered in the paper.
On Axion's Effect on Propagation of Monochromatic Electromagnetic Wave Through Strong Magnetic Field
Mikhail Khankhasayev; Carol Scarlett
2012-02-07T23:59:59.000Z
A possibility of detecting the effect of photon-axion mixing in a cavity experiment is discussed. There are two photon-axion modes that acquire different indices of refraction and split in an inhomogeneous magnetic field. For a magnetic field inhomogeneous in the direction transverse to the light propagation an analytical solution is obtained both for the index of refraction and the beams' trajectories. In a cavity experiment, the beam splitting creates a bifurcation effect, which results in a decrease of the light intensity in the central region. Modulation of magnetic field can separate this effect from background by providing a narrow frequency range for any observed signal. When one integrates this effect over time and accounts for bandwidth, the overall drop in FWHM intensity is of order 10-2%. This is a very measurable effect.
Eduardo Notte-Cuello; Waldyr A. Rodrigues Jr
2006-12-23T23:59:59.000Z
In this paper we prove in a rigorous mathematical way (using the Clifford bundle formalism) that the energies and momenta of two distinct and arbitrary free Maxwell fields (of finite energies and momenta) that are superposed are additive and thus that there is no incompatibility between the principle of superposition of fields and the principle of energy-momentum conservation, contrary to some recent claims. Our proof depends on a noticeable formula for the energy-momentum 1-form fields T^{a},namely Riesz formula, which is valid for any electromagnetic field configuration F satisfying Maxwell equation.
Malobabic, Sina; Jupe, Marco; Ristau, Detlev [Laser Component Department, Laser Zentrum Hannover e.V., Hollerithallee 8, 30149 Hannover (Germany) [Laser Component Department, Laser Zentrum Hannover e.V., Hollerithallee 8, 30149 Hannover (Germany); Quest: Centre of Quantum Engineering and Space-Time Research, Leibniz Universitaet Hannover, Hannover (Germany)
2013-06-03T23:59:59.000Z
Nowadays, Ion Beam Sputter (IBS) processes are very well optimized on an empirical basis. To achieve further progresses, a modification of the IBS process by guiding the coating material using an axial magnetic field and an additional electrical field has been studied. The electro-magnetic (EM) field leads to a significant change in plasma properties and deposition rate distributions, whereas an increase in deposition rate along the centerline of the axial EM field around 150% was observed. These fundamental studies on the prototype are the basis for the development of an applicable and workable design of a separation device.
Electromagnetic quasinormal modes of D-dimensional black holes
A. López-Ortega
2006-11-02T23:59:59.000Z
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.
Andreev, A A; Galkin, A L; Kalashnikov, M P; Korobkin, V V; Romanovsky, Mikhail Yu; Shiryaev, O B [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)
2011-08-31T23:59:59.000Z
We study the motion of an electron and emission of electromagnetic waves by an electron in the field of a relativistically intense laser pulse. The dynamics of the electron is described by the Newton equation with the Lorentz force in the right-hand side. It is shown that the electrons may be ejected from the interaction region with high energy. The energy spectrum of these electrons and the technique of using the spectrum to assess the maximal intensity in the focus are analysed. It is found that electromagnetic radiation of an electron moving in an intense laser field occurs within a small angle around the direction of the electron trajectory tangent. The tangent quickly changes its direction in space; therefore, electromagnetic radiation of the electron in the far-field zone in a certain direction in the vicinity of the tangent is a short pulse with a duration as short as zeptoseconds. The calculation of the temporary and spectral distribution of the radiation field is carried out. (superintense laser fields)
D. M. Volokitin
2010-06-23T23:59:59.000Z
In this article the algebra and the basis of corresponding analysis in 4-dimensional spaces are constructed, in pseudoeuclidean with signature (1, -1, -1, -1) and pseudo-Riemannian corresponding to the real space-time. In both cases the analogues of Cauchy-Riemann conditions are obtained. They are the systems of 1-st order partial differential equations, linear for the pseudoeuclidean and quasi-linear for the pseudo-Riemannian space (linear as about the components of differentiable function ant its derivatives so about the derivatives of metric tensor). The general solution for pseudoeuclidean space which is the flat waves of components of dependent function, and special (spherical-symmetric) wave-like (as for the components of differentiable function so for the components of metric tensor) solution for the pseudo-Riemannian space are got. In the last case the absence of central singularity for the components of metric tensor is interesting. From the Cauchy-Riemann condition follows that the differentiable function is constant along some isotropic curves given by 1-st order differential equations. The demand these curves to be geodetic lines leads to the differential restrictions for the metric tensor itself. The special kind of these restrictions is obtained. The hypothesis that the differentiable function can be interpreted as an electromagnetic field is expressed.
Second and Fourth Harmonic Frequencies in Electric Field-Induced Liquid Crystal Reorientations
Wu, Shin-Tson
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
Mikko Partanen; Teppo Häyrynen; Jani Oksanen; Jukka Tulkki
2014-12-02T23:59:59.000Z
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.
Ram, Nibedita; Pattabiraman, M.; Vijayan, C. [Department of Physics, Indian Institute of Technology, Madras, Chennai 600036 (India)
2010-09-15T23:59:59.000Z
The effect of incident light field ellipticity on the electromagnetically induced absorption (EIA) and electromagnetically induced transparency (EIT) resonances has been studied experimentally and computationally in Hanle configuration with longitudinal and transverse magnetic fields. We identify the Zeeman coherences that influence the resonance profile and study the role of coherence-transfer from excited to ground state via spontaneous emission as a function of ellipticity for the F{sub g}=2{yields}F{sub e}=3 transition of {sup 87}Rb. The EIT resonance observed with the light field locked on the F{sub g}=1{yields}F{sub e}=2 transition of {sup 87}Rb is an influence of the nearby F{sub g}=1{yields}F{sub e}=0 closed and F{sub g}=1{yields}F{sub e}=1 open transitions. With increase in ellipticity the observed EIA and EIT resonances diminish in amplitude for a longitudinal magnetic field and are enhanced for a transverse magnetic field. We computationally account for these observations and discuss the factors that influence the EIA and EIT resonance amplitudes as a function of ellipticity and show that for a transverse field scan the ellipticity dependence of the EIA resonance amplitude can be accounted for without invoking the Doppler effect unlike for a longitudinal field scan. We also show that the maximum in the EIA resonance amplitude obtained for nonzero ellipticities with a longitudinal magnetic field depends on the closedness of the atomic system.
Aerts, Sam, E-mail: sam.aerts@intec.ugent.be; Deschrijver, Dirk; Verloock, Leen; Dhaene, Tom; Martens, Luc; Joseph, Wout
2013-10-15T23:59:59.000Z
In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information—inside hotspots or in search of them—based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km{sup 2}. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2 dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. -- Highlights: • We present an iterative measurement and modeling method for outdoor RF-EMF exposure. • Hotspots are rapidly identified, and accurately characterized. • An accurate graphical representation, or heat map, is created, using kriging. • Random validation shows good correlation (0.7) and low relative errors (2 dB)
Tokman, M. D. [Institute of Applied Physics, RAS, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation)
2009-05-15T23:59:59.000Z
We discuss specific features of the electrodynamic characteristics of quantum systems within the framework of models that include a phenomenological description of the relaxation processes. As is shown by W. E. Lamb, Jr., R. R. Schlicher, and M. O. Scully [Phys. Rev. A 36, 2763 (1987)], the use of phenomenological relaxation operators, which adequately describe the attenuation of eigenvibrations of a quantum system, may lead to incorrect solutions in the presence of external electromagnetic fields determined by the vector potential for different resonance processes. This incorrectness can be eliminated by giving a gauge-invariant form to the relaxation operator. Lamb, Jr., et al. proposed the corresponding gauge-invariant modification for the Weisskopf-Wigner relaxation operator, which is introduced directly into the Schroedinger equation within the framework of the two-level approximation. In the present paper, this problem is studied for the von Neumann equation supplemented by a relaxation operator. First, we show that the solution of the equation for the density matrix with the relaxation operator correctly obtained ''from the first principles'' has properties that ensure gauge invariance for the observables. Second, we propose a common recipe for transformation of the phenomenological relaxation operator into the correct (gauge-invariant) form in the density-matrix equations for a multilevel system. Also, we discuss the methods of elimination of other inaccuracies (not related to the gauge-invariance problem) which arise if the electrodynamic response of a dissipative quantum system is calculated within the framework of simplified relaxation models (first of all, the model corresponding to constant relaxation rates of coherences in quantum transitions). Examples illustrating the correctness of the results obtained within the framework of the proposed methods in contrast to inaccuracy of the results of the standard calculation techniques are given.
Latyshev, A V
2015-01-01T23:59:59.000Z
Kinetic Vlasov-Boltzmann equation for degenerate collisional plasmas with integral of collisions of relaxation type BGK (Bhatnagar, Gross and Krook) is used. Square-law expansion on size of intensity of electric field for kinetic equation, Lorentz's force and integral of collisions is considered. It is shown, that nonlinearity leads to generation of the longitudinal electric current directed along a wave vector. Longitudinal current is perpendicular to the known transversal classical current received at the linear analysis. The case of small values of wave number is considered. When frequency of collisions tends to the zero, all received results for collisional pass plasmas in corresponding results for collisionless plasmas. Graphic research of the real and imaginary part current density is carried out.
Robertshaw, G.A.; Snyder, A.L.; Weiner, M.M.
1993-05-14T23:59:59.000Z
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.
M. Novello; F. T. Falciano; E. Goulart
2011-11-08T23:59:59.000Z
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.
Effects of magnetic field strength on the low frequency oscillation in Hall thrusters
Wang Chunsheng; Wei Liqiu; Ning Zhongxi; Yu Daren [Laboratory of Plasma Propulsion, Mail Box 458, Harbin Institute of Technology, Harbin 150001 (China)
2011-01-15T23:59:59.000Z
In order to study the effect of magnetic field strength on low frequency oscillation in Hall thrusters, experiments were carried out with different operating parameters. Experimental results show that the effect of magnetic field strength on the low frequency oscillation changes with operating parameters. In the decline zone of magnetoampere characteristic curve, low frequency oscillation increases with the increase of magnetic field strength at low mass flow rate, while decreases with the increase of magnetic field strength at high mass flow rate. With further experiments and numerical simulations, it is found that the change of electron current at low mass flow rate and the change of ion current at high mass flow rate account for the variations of low frequency oscillation. Finally, the physical analysis is performed.
Alex J. Dragt
2012-08-31T23:59:59.000Z
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.
Chueng-Ryong Ji; Ziyue Li; Alfredo Takashi Suzuki
2014-12-08T23:59:59.000Z
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.
Lau, Ryan
2007-09-17T23:59:59.000Z
frequency electromagnetic signal into the sea and downwards into the seabed. A transmitter is typically towed behind a ship to various offsets at which time an electromagnetic field is emitted from the dipole. The primary electromagnetic (EM) energy... possible direct hydrocarbon indicator for deep-sea prospects using EM energy: Oil & Gas Journal 100, 19, 30-38. MacGregor, L., and Sinha, M., 2000, Use of marine controlled-source electromagnetic sounding sub-basalt exploration: Geophysical...
Zero field high frequency oscillations in dual free layer spin torque oscillators
Braganca, P. M., E-mail: patrick.braganca@hgst.com; Pi, K.; Zakai, R.; Childress, J. R.; Gurney, B. A. [HGST, 3404 Yerba Buena Rd., San Jose, California 95135 (United States)] [HGST, 3404 Yerba Buena Rd., San Jose, California 95135 (United States)
2013-12-02T23:59:59.000Z
We observe microwave oscillations in relatively simple spin valve spin torque oscillators consisting of two in-plane free layers without spin polarizing layers. These devices exhibit two distinct modes which can reach frequencies >25?GHz in the absence of an applied magnetic field. Macrospin simulations identify these two modes as optical and acoustic modes excited by the coupling of the two layers through dipole field and spin torque effects. These results demonstrate the potential of this system as a large output power, ultrahigh frequency signal generator that can operate without magnetic field.
Reznik, Alexander N., E-mail: reznik@ipm.sci-nnov.ru [Institute for Physics of Microstructures of the Russian Academy of Sciences, GSP-105, Nizhniy Novgorod 603950, Russia, and Lobachevsky State University of Nizhny Novgorod, 23, pr. Gagarina, N. Novgorod 603950 (Russian Federation)
2014-08-25T23:59:59.000Z
An electrodynamic model is proposed for the tunneling microwave microscope with subnanometer space resolution as developed by Lee et al. [Appl. Phys. Lett. 97, 183111 (2010)]. Tip-sample impedance Z{sub a} was introduced and studied in the tunneling and non-tunneling regimes. At tunneling breakdown, the microwave current between probe and sample flows along two parallel channels characterized by impedances Z{sub p} and Z{sub t} that add up to form overall impedance Z{sub a}. Quantity Z{sub p} is the capacitive impedance determined by the near field of the probe and Z{sub t} is the impedance of the tunnel junction. By taking into account the distance dependences of effective tip radius r{sub 0}(z) and tunnel resistance R{sub t}(z)?=?Re[Z{sub t}(z)], we were able to explain the experimentally observed dependences of resonance frequency f{sub r}(z) and quality factor Q{sub L}(z) of the microscope. The obtained microwave resistance R{sub t}(z) and direct current tunnel resistance R{sub t}{sup dc}(z) exhibit qualitatively similar behavior, although being largely different in both magnitude and the characteristic scale of height dependence. Interpretation of the microwave images of the atomic structure of test samples proved possible by taking into account the inductive component of tunnel impedance ImZ{sub t}?=??L{sub t}. Relation ?L{sub t}/R{sub t}???0.235 was obtained.
ECE 342: Electromagnetic Fields II -Knows how to express a wave propagating in a
Schumacher, Russ
model the frequency response of transmission lines - Understands transmission line matching - Can use - Optical fibers Electrodynamics Transmission lines EM waves - Understand fundamentals of energy storage theory and electrical engineering as a whole EM waves and Energy Maxwell's Equations Concepts
Control of resonant frequency by currents in graphene: Effect of Dirac field on deflection
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
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?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.
Plimak, L.I., E-mail: lev.plimak@uni-ulm.de [Institut fuer Quantenphysik, Universitaet Ulm, 89069 Ulm (Germany); Stenholm, S. [Institut fuer Quantenphysik, Universitaet Ulm, 89069 Ulm (Germany) [Institut fuer Quantenphysik, Universitaet Ulm, 89069 Ulm (Germany); Physics Department, Royal Institute of Technology, KTH, Stockholm (Sweden); Laboratory of Computational Engineering, HUT, Espoo (Finland)
2012-11-15T23:59:59.000Z
The connection between real-time quantum field theory (RTQFT) [see, e.g., A. Kamenev and A. Levchenko, Adv. Phys. 58 (2009) 197] and phase-space techniques [E. Wolf and L. Mandel, Optical Coherence and Quantum Optics (Cambridge, 1995)] is investigated. The Keldysh rotation that forms the basis of RTQFT is shown to be a phase-space mapping of the quantum system based on the symmetric (Weyl) ordering. Following this observation, we define generalised Keldysh rotations based on the class of operator orderings introduced by Cahill and Glauber [K.E. Cahill, R.J. Glauber, Phys. Rev. 177 (1969) 1882]. Each rotation is a phase-space mapping, generalising the corresponding ordering from free to interacting fields. In particular, response transformation [L.I. Plimak, S. Stenholm, Ann. Phys. (N.Y.) 323 (2008) 1989] extends the normal ordering of free-field operators to the time-normal ordering of Heisenberg operators. Structural properties of the response transformation, such as its association with the nonlinear quantum response problem and the related causality properties, hold for all generalised Keldysh rotations. Furthermore, we argue that response transformation is especially suited for RTQFT formulation of spatial, in particular, relativistic, problems, because it extends cancellation of zero-point fluctuations, characteristic of the normal ordering, to interacting fields. As an example, we consider quantised electromagnetic field in the Dirac sea. In the time-normally-ordered representation, dynamics of the field looks essentially classical (fields radiated by currents), without any contribution from zero-point fluctuations. For comparison, we calculate zero-point fluctuations of the interacting electromagnetic field under orderings other than time-normal. The resulting expression is physically inconsistent: it does not obey the Lorentz condition, nor Maxwell's equations. - Highlights: Black-Right-Pointing-Pointer The Keldysh rotation is a phase-space mapping based on Weyl's operator ordering. Black-Right-Pointing-Pointer Generalised Keldysh rotations (GKRs) based on other orderings are introduced. Black-Right-Pointing-Pointer Special properties of the GKR based on the normal ordering are elucidated. Black-Right-Pointing-Pointer In relativistic QED, other rotations are shown to be physically inconsistent.
Self-Duality in Nonlinear Electromagnetism
Mary K. Gaillard; Bruno Zumino
1997-05-28T23:59:59.000Z
We discuss duality invariant interactions between electromagnetic fields and matter. The case of scalar fields is treated in some detail.
Noninvasive valve monitor using constant magnetic and/or DC electromagnetic field
Casada, Donald A. (Knoxville, TN); Haynes, Howard D. (Knoxville, TN)
1993-01-01T23:59:59.000Z
One or more sources of steady magnetic field are carefully located on the outside of a valve body. The constant magnetic field is transmitted into the valve body and valve internals. A magnetic field detector carefully located on the outside of the valve body detects the intensity of the magnetic field at its location. As the position of a valve internal part is changed, there is an alteration in the magnetic field in the valve, and a consequent change in the detected magnetic field. Changes in the detected signal provide an indication of the position and motion of the valve internals.
Rutledge, Steven
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
Dah-Wei Chiou; Tsung-Wei Chen
2015-04-14T23:59:59.000Z
It has long been speculated that the Dirac or, more generally, the Dirac-Pauli spinor in the Foldy-Wouthuysen (FW) representation should behave like a classical relativistic spinor in the low-energy limit when the particle-antiparticle interaction is negligible. In the weak-field limit of static and homogeneous electromagnetic fields, we rigorously prove, by applying Kutzelnigg's method inductively on the orders of $1/c$ in the power series, that it is indeed the case: the FW transformation of the Dirac-Pauli Hamiltonian is in full agreement with the classical counterpart, which is the sum of the orbital Hamiltonian for the Lorentz force equation and the spin Hamiltonian for the Thomas-Bargmann-Michel-Telegdi equation.
Development and Field Testing of a DSP-Based Dual-Frequency Software GPS Receiver
Psiaki, Mark L.
Development and Field Testing of a DSP-Based Dual-Frequency Software GPS Receiver Brady W. O'Hanlon, Mark L. Psiaki, Paul M. Kintner, Jr., Cornell University, Ithaca, NY Todd E. Humphreys, The University of Texas at Austin, Austin, TX BIOGRAPHY Brady W. O'Hanlon is a graduate student in the School
Coincident-Frequency Entangled Photons in a Homogenous Gravitational Field - A Thought Experiment
Clovis Jacinto de Matos
2010-11-24T23:59:59.000Z
Assuming that the Principle of energy conservation holds for coincident-frequency entangled photons propagating in a homogeneous gravitational field. It is argued that in this physical context, either Quantum entanglement or the weak equivalence principle are broken by the photons.
Bogdanov, O V
2014-01-01T23:59:59.000Z
The relations among the components of the exit momenta of ultrarelativistic electrons scattered on a strong electromagnetic wave of a low (optical) frequency and linear polarization are established using the exact solutions to the equations of motion with radiation reaction included (the Landau-Lifshitz equation). It is found that the momentum components of the electrons traversed the electromagnetic wave depend weakly on the initial values of the momenta. These electrons are mostly scattered at the small angles to the direction of propagation of the electromagnetic wave. The maximum Lorentz factor of the electrons crossed the electromagnetic wave is proportional to the work done by the electromagnetic field and is independent of the initial momenta. The momentum component parallel to the electric field strength vector of the electromagnetic wave is determined only by the diameter of the laser beam measured in the units of the classical electron radius. As for the reflected electrons, they for the most part l...
Tucker, Eric; Boreman, Glenn, E-mail: gboreman@uncc.edu [Department of Physics and Optical Science, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, North Carolina 28223 (United States); D'Archangel, Jeffrey [CREOL, The College of Optics and Photonics, University of Central Florida, 4304 Scorpius St., Orlando, Florida 32816 (United States); Raschke, Markus B. [Department of Physics, Department of Chemistry, and JILA, University of Colorado, 390 UCB, Boulder, Colorado 80309 (United States)
2014-07-28T23:59:59.000Z
Near- and far-field measurements of phase-ramped loop and patch structures are presented and compared to simulations. The far-field deflection measurements show that the phase-ramped structures can deflect a beam away from specular reflection, consistent with simulations. Scattering scanning near-field optical microscopy of the elements comprising the phase ramped structures reveals part of the underlying near-field phase contribution that dictates the far-field deflection, which correlates with the far-field phase behavior that was expected. These measurements provide insight into the resonances, coupling, and spatial phase variation among phase-ramped frequency selective surface (FSS) elements, which are important for the performance of FSS reflectarrays.
Waggoner, J.R.; Mansure, A.J.
1992-02-01T23:59:59.000Z
This report is a permanent record of a poster paper presented by the authors at the Third International Reservoir Characterization Technical Conference in Tulsa, Oklahoma on November 3--5, 1991. The subject is electromagnetic (EM) techniques that are being developed to monitor oil recovery processes to improve overall process performance. The potential impact of EM surveys is very significant, primarily in the areas of locating oil, identifying oil inside and outside the pattern, characterizing flow units, and pseudo-real time process control to optimize process performance and efficiency. Since a map of resistivity alone has little direct application to these areas, an essential part of the EM technique is understanding the relationship between the process and the formation resistivity at all scales, and integrating this understanding into reservoir characterization and simulation. First is a discussion of work completed on the core scale petrophysics of resistivity changes in an oil recovery process; a steamflood is used as an example. A system has been developed for coupling the petrophysics of resistivity with reservoir simulation to simulate the formation resistivity structure arising from a recovery process. Preliminary results are given for an investigation into the effect of heterogeneity and anisotropy on the EM technique, as well as the use of the resistivity simulator to interpret EM data in terms of reservoir and process parameters. Examples illustrate the application of the EM technique to improve process monitoring and reservoir characterization.
Howell, Robert Sherwood
1972-01-01T23:59:59.000Z
13 birds in remainder of experiment. ~fel l. ~Eff o ~* ~st ~et~ass Eeoc~of ' ~o t *l ct o *t' ~*t ', ~o~es tfc~f' lo E e et l Treatments Day 8 Day 15 Day 22 ratio& ~ %( )ratio % ratio Control 260 MHz 915 MHz Electric field-45 Hz Magnetic field...
Jia Zhang [Department of Materials Processing Engineering, School of Materials Science and Engineering, Dalian University of Technology, Linggong Road 2, Ganjingzi District, Dalian 116085, Liaoning Province (China); Duan Yuping, E-mail: duanyp@dlut.edu.c [Department of Materials Processing Engineering, School of Materials Science and Engineering, Dalian University of Technology, Linggong Road 2, Ganjingzi District, Dalian 116085, Liaoning Province (China); Li Shuqing, E-mail: lsq6668@126.co [Beijing Aeronautical Manufacturing Technology Research Institute, 1 Jun Zhuang east Road, Chaoyang District, Beijing 100024 (China); Li Xiaogang, E-mail: lixiaogang99@263.ne [School of Materials Science and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083 (China); Liu Shunhua [Department of Materials Processing Engineering, School of Materials Science and Engineering, Dalian University of Technology, Linggong Road 2, Ganjingzi District, Dalian 116085, Liaoning Province (China)
2010-07-15T23:59:59.000Z
MnO{sub 2} with a sea urchin-like ball chain shape was first synthesized in a high magnetic field via a simple chemical process, and a mechanism for the formation of this grain shape was discussed. The as-synthesized samples were characterized by XRD, SEM, TEM, and vector network analysis. The dielectric constant and the loss tangent clearly decreased under a magnetic field. The magnetic loss tangent and the imaginary part of the magnetic permeability increased substantially. Furthermore, the theoretically calculated values of reflection loss showed that the absorption peaks shifted to a higher frequency with increases in the magnetic field strength. - Graphical abstract: MnO{sub 2} with a sea urchin-like ball chain shape is first synthesized in a high magnetic field via a simple hydrothermal route.
Thomas, Brian G.
system was tested in the presence of an electromagnetic field at a commercial steel company and was shown casting, this sensor will monitor the thermal condition of the mold. The sensors inside the fiber function system causes the wavelength of light emitted along the fiber to depend on thermal strain, which varies
14 Effect of Electromagnetic Fields on Marine Ralf Bochert, Michael L Zettler
Zettler, Michael
of offshore wind farms in natural geomagnetic field environments. The movement of the wind over the blades offshore wind farms. Both variants, alter- nating current (AC) and direct current (DC) have been used
Fiber optic probe of free electron evanescent fields in the optical frequency 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
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.
Assessing human exposure to power-frequency electric and magnetic fields
Kaune, W.T. [EM Factors, Richland, WA (United States)
1993-12-01T23:59:59.000Z
This paper reviews published literature and current problems relating to the assessment of occupational and residential human exposures to power-frequency electric and magnetic fields. Available occupational exposure data suggest that the class of job titles known as electrical workers may be an effective surrogate for time-weighted-average (TWA) magnetic-field (but not electric-field) exposure. Current research in occupational-exposure assessment is directed to the construction of job-exposure matrices based on electric- and magnetic-field measurements and estimates of worker exposures to chemicals and other factors of interest. Recent work has identified five principal sources of residential magnetic fields: electric power transmission lines, electric power distribution lines, ground currents, home wiring, and home appliances. Existing residential-exposure assessments have used one or more of the following techniques: questionnaires, wiring configuration coding, theoretical field calculations, spot electric- and magnetic-field measurements, fixed-site magnetic-field recordings, personal-exposure measurements, and geomagnetic-field measurements. Available normal-power magnetic-field data for residences differ substantially between studies. It is not known if these differences are due to geographical differences, differences in measurement protocols, or instrumentation differences. Available data suggest, but are far from proving, that spot measurements may be more effective than wire codes as predictors of long-term historical magnetic-field exposure. Two studies find that away-from-home TWA magnetic-field exposures are less variable than at home exposures. The importance of home appliances as contributors to total residential magnetic-field exposure is not known at this time. It also is not known what characteristics (if any) of residential electric and magnetic fields are determinants of human health effects. 41 refs., 9 figs., 10 tabs.
Invertibility of current density from near-field electromagnetic data D. J. Sheltrawa)
Coutsias, Evangelos
about the primary current source Jp due to direct neuronal activity and defined in the following of the current source underlying the electric and magnetic fields measured outside the source. However see-planar case .4 In neuroscience applications one is usually interested in obtaining information
Hot electromagnetic outflows. III. Displaced fireball in a strong magnetic field
Thompson, Christopher; Gill, Ramandeep [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)
2014-08-10T23:59:59.000Z
The evolution of a dilute electron-positron fireball is calculated in the regime of strong magnetization and high compactness (? ? 10{sup 3}-10{sup 8}). Heating is applied at a low effective temperature (<25 keV), appropriate to breakout from a confining medium, so that relaxation to a blackbody is inhibited by pair annihilation. The diffusion equation for Compton scattering by thermal pairs is coupled to a trans-relativistic cyclo-synchrotron source. We find that the photon spectrum develops a quasi-thermal peak at energy ?0.1 m{sub e}c {sup 2} in the comoving frame, with a power-law slope below it that is characteristic of gamma-ray bursts (GRBs; F{sub ?} ? const). The formation of a thermal high-energy spectrum is checked using the full kinetic equations. Calculations for a baryon-dominated photosphere reveal a lower spectral peak energy, and a harder low-energy spectrum, unless ion rest mass carries ? 10{sup –5} of the energy flux. We infer that (1) the GRB spectrum is inconsistent with the neutron-rich wind emitted by a young magnetar or neutron torus, and points to an event horizon in the engine; (2) neutrons play a negligible role in prompt gamma-ray emission; (3) the relation between observed peak frequency and burst energy is bounded below by the observed Amati relation if the Lorentz factor ?(opening angle){sup –1} at breakout, and the jet is surrounded by a broader sheath that interacts with a collapsing stellar core; (4) X-ray flashes are consistent with magnetized jets with ion-dominated photospheres; (5) high-frequency Alfvén waves may become charge starved in the dilute pair gas; (6) limitations on magnetic reconnection from plasma collisionality have been overestimated.
Gruner, George
Frequency- and electric-field-dependent conductivity of single-walled carbon nanotube networks October 2007; published 20 February 2008 We present measurements of the frequency- and electric-field-dependent conductivity of single-walled car- bon nanotube SWCNT networks of various densities. The ac conductivity
Barbosa, Séverine; Ducruix, Sébastien
2008-01-01T23:59:59.000Z
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.
Electromagnetic structure of light nuclei
Saori Pastore
2015-08-28T23:59:59.000Z
The present understanding of nuclear electromagnetic properties including electromagnetic moments, form factors and transitions in nuclei with A $\\le$ 10 is reviewed. Emphasis is on calculations based on nuclear Hamiltonians that include two- and three-nucleon realistic potentials, along with one- and two-body electromagnetic currents derived from a chiral effective field theory with pions and nucleons.
A. L. Garcia-Perciante; A. Sandoval-Villalbazo; D. Brun-Battistini
2015-04-09T23:59:59.000Z
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
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.
Cell bystander effect induced by radiofrequency electromagnetic fields and magnetic nanoparticles
Goya, G F; Calatayud, M P; Tres, A; Ibarra, M R
2015-01-01T23:59:59.000Z
Induced effects by direct exposure to ionizing radiation (IR) are a central issue in many fields like radiation protection, clinic diagnosis and oncological therapies. Direct irradiation at certain doses induce cell death, but similar effects can also occur in cells no directly exposed to IR, a mechanism known as bystander effect. Non-IR (radiofrequency waves) can induce the death of cells loaded with MNPs in a focused oncological therapy known as magnetic hyperthermia. Indirect mechanisms are also able to induce the death of unloaded MNPs cells. Using in vitro cell models, we found that colocalization of the MNPs at the lysosomes and the non-increase of the temperature induces bystander effect under non-IR. Our results provide a landscape in which bystander effects are a more general mechanism, up to now only observed and clinically used in the field of radiotherapy.
Cell bystander effect induced by radiofrequency electromagnetic fields and magnetic nanoparticles
G. F. Goya; L. Asin; M. P. Calatayud; A. Tres; M. R. Ibarra
2015-06-03T23:59:59.000Z
Induced effects by direct exposure to ionizing radiation (IR) are a central issue in many fields like radiation protection, clinic diagnosis and oncological therapies. Direct irradiation at certain doses induce cell death, but similar effects can also occur in cells no directly exposed to IR, a mechanism known as bystander effect. Non-IR (radiofrequency waves) can induce the death of cells loaded with MNPs in a focused oncological therapy known as magnetic hyperthermia. Indirect mechanisms are also able to induce the death of unloaded MNPs cells. Using in vitro cell models, we found that colocalization of the MNPs at the lysosomes and the non-increase of the temperature induces bystander effect under non-IR. Our results provide a landscape in which bystander effects are a more general mechanism, up to now only observed and clinically used in the field of radiotherapy.
Kohno, H. [Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, Pennsylvania 18015 (United States)] [Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, Pennsylvania 18015 (United States); Myra, J. R.; D'Ippolito, D. A. [Lodestar Research Corporation, 2400 Central Avenue P-5, Boulder, Colorado 80301 (United States)] [Lodestar Research Corporation, 2400 Central Avenue P-5, Boulder, Colorado 80301 (United States)
2013-08-15T23:59:59.000Z
Computer simulations of radio-frequency (RF) waves propagating across a two-dimensional (2D) magnetic field into a conducting boundary are described. The boundary condition for the RF fields at the metal surface leads to the formation of an RF sheath, which has previously been studied in one-dimensional models. In this 2D study, it is found that rapid variation of conditions along the sheath surface promote coupling of the incident RF branch (either fast or slow wave) to a short-scale-length sheath-plasma wave (SPW). The SPW propagates along the sheath surface in a particular direction dictated by the orientation of the magnetic field with respect to the surface, and the wave energy in the SPW accumulates near places where the background magnetic field is tangent to the surface.
Kozlovskii, Andrei V [P N Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation)
2010-05-26T23:59:59.000Z
The quantum dynamics of a system consisting of a moving two-level atom and a single-mode electromagnetic field in the standing-wave resonator is studied by using the stationary phase approximation. The conditions resulting in the emergence of the collapse - revival effect of Doppler - Rabi oscillations are analysed for the initial coherent state of the electromagnetic field in the resonator. It is shown that both the character and the possibility of this effect emergence directly depend on the initial parameters of the system: the rate of the atomic centre-of-mass motion, coupling constants of the atom with the field, the mean number of photons in the resonator. Under conditions when the collapse - revival effect is absent, the system dynamics qualitatively depends on the intial electronic state of the atom. (nonlinear optical phenomena)
Meng, Yi, E-mail: yimonmy@sina.com; Cui, Jianzhong; Zhao, Zhihao; He, Lizi
2014-06-01T23:59:59.000Z
The Al-1.6Mg-1.2Si-1.1Cu-0.15Cr (all in wt. %) alloys with and without Zr addition prepared by low frequency electromagnetic casting process were investigated by using the optical microscope, scanning electron microscope and transmission electron microscope equipped with energy dispersive analytical X-ray. The effects of Al{sub 3}Zr phases on the microstructures and mechanical properties during solidification, homogenization, hot extrusion and solid solution were studied. The results show that Al{sub 3}Zr phases reduce the grain size by ? 29% and promote the formation of an equiaxed grain structure during solidification. Numerous spherical Al{sub 3}Zr dispersoids with 35–60 nm in diameters precipitate during homogenization, and these fine dispersoids change little during subsequent hot extrusion and solid solution. Adding 0.15 wt. % Zr results in no recrystallization after hot extrusion and partial recrystallization after solid solution, while the recrystallized grain size is 400–550 ?m in extrusion direction in the Zr-free alloy. In addition, adding 0.15 wt. % Zr can obviously promote Q? phase precipitation, while the ?? phases are predominant in the alloy without Zr. Adding 0.15 wt. % Zr, the ultimate tensile strength of the T6 treated alloy increases by 45 MPa, while the elongation remains about 16.7%. - Highlights: • Minor Zr can refine as-cast grains of the LFEC Al-Mg-Si-Cu-Cr alloy. • L1{sub 2} Al{sub 3}Zr phases with 35–60 nm in diameter precipitate during homogenization. • L1{sub 2} and DO{sub 22} Al{sub 3}Zr phases result in partial recrystallization after solid solution. • Minor Zr can promote the precipitation of Q? phases. • Mechanical properties of Al-Mg-Si-Cu-Cr-Zr alloy are higher than those of AA7005.
Khenner, Mikhail
Enhanced stability of a dewetting thin liquid film in a single-frequency vibration field S is considered. We assume moderate vibration frequency and large compared to the mean film thickness vibration that such vibration stabilizes the film against dewetting and rupture. DOI: 10.1103/PhysRevE.77.036320 PACS number
G. M. Nikolopoulos; P. Lambropoulos
2012-09-11T23:59:59.000Z
We study the effects of field fluctuations on the total yields of Auger electrons, obtained in the excitation of neutral atoms to a core-excited state by means of short-wavelength free-electron-laser pulses. Beginning with a self-contained analysis of the statistical properties of fluctuating free-electron-laser pulses, we analyse separately and in detail the cases of single and double Auger resonances, focusing on fundamental phenomena such as power broadening and ac Stark (Autler-Townes) splitting. In certain cases, field fluctuations are shown to influence dramatically the frequency response of the resonances, whereas in other cases the signal obtained may convey information about the bandwidth of the radiation as well as the dipole moment between Auger states.
The frequency spectrum of the Casimir effect
Lang, Andrew S.I.D. [Computer Science and Mathematics Department, Oral Roberts University, Tulsa, Oklahoma 74171 (United States)
2005-10-01T23:59:59.000Z
The frequency spectrum of the Casimir effect between parallel plates is studied. Calculations are performed for both the massless scalar field and the electromagnetic field cases, first using a spectral weight function, and then via the Fourier transform of the renormalized expectation of the Casimir energy-momentum operator. The Casimir force is calculated using the spectrum for two plates which are perfectly transparent in a frequency band. The result of this calculation suggests a way to detect the frequency spectrum of the Casimir effect.
Low frequency noise in AlGaN/InGaN/GaN double heterostructure field effect transistors
Pala, Nezih
Torr and consisted of a 1.4 lm undoped GaN buffer layer on i-SiC substrate, * Corresponding authorLow frequency noise in AlGaN/InGaN/GaN double heterostructure field effect transistors N. Pala a November 2002 Abstract Low-frequency noise in AlGaN/InGaN/GaN double heterostructure field effect
Viktor Stepanov; Franklin H. Cho; Chathuranga Abeywardana; Susumu Takahashi
2015-02-11T23:59:59.000Z
We present the development of an optically detected magnetic resonance (ODMR) system, which enables us to perform the ODMR measurements of a single defect in solids at high frequencies and high magnetic fields. Using the high-frequency and high-field ODMR system, we demonstrate 115 GHz continuous-wave and pulsed ODMR measurements of a single nitrogen-vacancy (NV) center in a diamond crystal at the magnetic field of 4.2 Tesla as well as investigation of field dependence ($0-8$ Tesla) of the longitudinal relaxation time ($T_1$) of NV centers in nanodiamonds.
Anderson, L.E.
1994-03-01T23:59:59.000Z
There is now convincing evidence from a large number of laboratories, that exposure to extremely low frequency (ELF) magnetic and electric fields produces biological responses in animals. Many of the observed effects appear to be directly or indirectly associated with the neural or neuroendocrine systems. Such effects include increased neuronal excitability, chemical and hormonal changes in the nervous system, altered behavioral responses, some of which are related to sensing the presence of the field, and changes in endogenous biological rhythms. Additional indices of general physiological status appear relatively unaffected by exposure, although effects have occasionally been described in bone growth and fracture repair, reproduction and development, and immune system function. A major current emphasis in laboratory research is to determine whether or not the reported epidemiological studies that suggest an association between EMF exposure and risk of cancer are supported in studies using animal models. Three major challenges exist for ongoing research: (1) knowledge about the mechanisms underlying observed bioeffects is incomplete, (2) researchers do not as yet understand what physical aspects of exposure produce biological responses, and (3) health consequences resulting from ELF exposure are unknown. Although no animal studies clearly demonstrate deleterious effects of ELF fields, several are suggestive of potential health impacts. From the perspective of laboratory animal studies, this paper will discuss biological responses to ELF magnetic and/or electric field exposures.
Emmanouilidou, A
2008-01-01T23:59:59.000Z
We explore the dependence of the double ionization of the He atom on the frequency of a strong laser field while keeping the ponderomotive energy constant. As we increase the frequency we find that the remarkable "finger-like" structure for high momenta recently found for $\\omega=0.055$ a.u. \\cite{Staudte, Rudenko} persists for higher frequencies. At the same time, at $\\omega=0.187$ a.u. a new X-shape structure emerges for small momenta that prevails in the correlated momenta distribution. The role of this structure as a signature of the frequency dependence of non-sequential double ionization is discussed.
Nuclear electromagnetic pulse and the electric power system
Legro, J.R.; Reed, T.J.
1985-01-01T23:59:59.000Z
A single, high-altitude nuclear detonation over the continental United States can expose large geographic areas to transient, electromagnetic pulse (EMP). The initial electromagnetic fields produced by this event have been defined as high-altitude electromagnetic pulse (HEMP). Later-time, low frequency fields have been defined as magnetohydrodynamic-electromagnetic pulse (MHD-EMP). Nuclear detonations at, or near the surface of the earth can also produce transient EMP. These electromagnetic phenomena have been defined as source region electromagnetic pulse (SREMP). The Division of Electric Energy Systems (EES) of the United States Department of Energy (DOE) has formulated and implemented a Program Plan to assess the possible effects of the above nuclear EMP on civilian electric power systems. This unclassified research effort is under the technical leadership of the Oak Ridge National Laboratory. This paper presents a brief perspective of EMP phenomenology and important interaction issues for power systems based on research performed by Westinghouse Advanced Systems Technology as a principal subcontractor in the research effort.
Hansman, Robert John
1982-01-01T23:59:59.000Z
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 ...
Beam dynamics studies for transverse electromagnetic mode type rf deflectors
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
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
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.
Statistics of the electromagnetic response of a chaotic reverberation chamber
J. -B. Gros; U. Kuhl; O. Legrand; F. Mortessagne; O. Picon; E. Richalot
2014-09-20T23:59:59.000Z
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.
Electromagnetic effects on geodesic acoustic modes
Bashir, M. F., E-mail: frazbashir@yahoo.com [Salam Chair in Physics, G. C. University Lahore, Katchery Road, Lahore 54000 (Pakistan); Department of Physics, G. C. University Lahore, Katchery Road, Lahore 54000 (Pakistan); Smolyakov, A. I. [University of Saskatchewan, 116 Science Place, Saskatoon S7N 5E2 (Canada); Institute of Tokamak Physics, NRC “Kurchatov Institute,” 123182 Moscow (Russian Federation); Elfimov, A. G. [Institute of Physics, University of São Paulo, São Paulo 05508-090 (Brazil); Melnikov, A. V. [Institute of Tokamak Physics, NRC “Kurchatov Institute,” 123182 Moscow (Russian Federation); National Research Nuclear University MEPhI, 115409, Moscow (Russian Federation); Murtaza, G. [Visiting Professor, Department of Physics, Quaid-e-Azam University, Islamabad (Pakistan)
2014-08-15T23:59:59.000Z
By using the full electromagnetic drift kinetic equations for electrons and ions, the general dispersion relation for geodesic acoustic modes (GAMs) is derived incorporating the electromagnetic effects. It is shown that m?=?1 harmonic of the GAM mode has a finite electromagnetic component. The electromagnetic corrections appear for finite values of the radial wave numbers and modify the GAM frequency. The effects of plasma pressure ?{sub e}, the safety factor q, and the temperature ratio ? on GAM dispersion are analyzed.
611: Electromagnetic Theory Problem Sheet 5
Pope, Christopher
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
611: Electromagnetic Theory Problem Sheet 6
Pope, Christopher
611: Electromagnetic Theory Problem Sheet 6 (1) A small test particle (mass m and positive charge q of the orbit. (2a) Consider an electromagnetic wave for which the electric field is given by E = E0 sin t (sin in (2a) and (2b) for an electromagnetic wave for which the electric field is E = E0 cos z (cos t, - sin
Ovchinnikov, K. N.; Uryupin, S. A., E-mail: uryupin@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)
2013-09-15T23:59:59.000Z
Specific features of the interaction of a relatively weak electromagnetic pulse with a nonisothermal current-carrying plasma in which the electron drift velocity is much higher than the ion-acoustic velocity, but lower than the electron thermal velocity, are studied. If the state of the plasma with ion-acoustic turbulence does not change during the pulse action, the field penetrates into the plasma in the ordinary diffusion regime, but the diffusion coefficient in this case is inversely proportional to the anomalous conductivity. If, during the pulse action, the particle temperatures and the current-driving field change due to turbulent heating, the field penetrates into the plasma in the subdiffusion regime. It is shown how the presence of subdiffusion can be detected by measuring the reflected field.
Radial electric field generated by resonant trapped electron pinch with radio frequency injection of Modern Physics, University of Science and Technology of China, Hefei 230026, China (Received 10 May 2011 by charge accumulation due to a resonant trapped electron pinch effect. The radial field can then drive
Why Study Electromagnetics: The First Unit in an Undergraduate Electromagnetics Course
Taflove, Allen
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
Motion of free spins and NMR imaging without a radio-frequency magnetic field
Kees van Schenk Brill; Jassem Lahfadi; Tarek Khalil; Daniel Grucker
2015-04-19T23:59:59.000Z
NMR imaging without any radio-frequency magnetic field is explained by a quantum treatment of independent spin~$\\tfrac 12$. The total magnetization is determined by means of their individual wave function. The theoretical treatment, based on fundamental axioms of quantum mechanics and solving explicitly the Schr\\"{o}dinger equation with the kinetic energy part which gives the motion of free spins, is recalled. It explains the phase shift of the spin noise spectrum with its amplitude compared to the conventional NMR spectrum. Moreover it explains also the relatively good signal to noise ratio of NMR images obtained without a RF pulse. This derivation should be helpful for new magnetic resonance imaging sequences or for developing quantum computing by NMR.
The spinor field theory of the photon
Ruo Peng Wang
2011-09-18T23:59:59.000Z
I introduce a spinor field theory for the photon. The three-dimensional vector electromagnetic field and the four-dimensional vector potential are components of this spinor photon field. A spinor equation for the photon field is derived from Maxwell's equations,the relations between the electromagnetic field and the four-dimensional vector potential, and the Lorentz gauge condition. The covariant quantization of free photon field is done, and only transverse photons are obtained. The vacuum energy divergence does not occur in this theory. A covariant "positive frequency" condition is introduced for separating the photon field from its complex conjugate in the presence of the electric current and charge.
Zolper, John C. (Vienna, VA); Sherwin, Marc E. (Rockville, MD); Baca, Albert G. (Albuquerque, NM)
2000-01-01T23:59:59.000Z
A method for making compound semiconductor devices including the use of a p-type dopant is disclosed wherein the dopant is co-implanted with an n-type donor species at the time the n-channel is formed and a single anneal at moderate temperature is then performed. Also disclosed are devices manufactured using the method. In the preferred embodiment n-MESFETs and other similar field effect transistor devices are manufactured using C ions co-implanted with Si atoms in GaAs to form an n-channel. C exhibits a unique characteristic in the context of the invention in that it exhibits a low activation efficiency (typically, 50% or less) as a p-type dopant, and consequently, it acts to sharpen the Si n-channel by compensating Si donors in the region of the Si-channel tail, but does not contribute substantially to the acceptor concentration in the buried p region. As a result, the invention provides for improved field effect semiconductor and related devices with enhancement of both DC and high-frequency performance.
Electromagnetically Induced Entanglement
Xihua Yang; Min Xiao
2015-05-18T23:59:59.000Z
We present a novel quantum phenomenon named electromagnetically induced entanglement in the conventional Lambda-type three-level atomic system driven by a strong pump field and a relatively weak probe field. Nearly perfect entanglement between the pump and probe fields can be achieved with a low coherence decay rate between the two lower levels, high pump-field intensity, and large optical depth of the atomic ensemble. The physical origin is quantum coherence between the lower doublet produced by the pump and probe fields, similar to the well-known electromagnetically induced transparency. This method would greatly facilitate the generation of nondegenerate narrow-band continuous-variable entanglement between bright light beams by using only coherent laser fields, and may find potential and broad applications in realistic quantum information processing.
Dr. S. Cruz-Pol, INEL 4152-Electromagnetics
Cruz-Pol, Sandra L.
field density [VF/m2] ØH = magnetic field intensity, [A/m] ØB = magnetic field density, [Teslas] Take JdlH Cruz-Pol, Electromagnetics UPRM Electromagnetics Ø This is the principle of motors, hydro
Quaternion Gravi-Electromagnetism
A. S. Rawat; O. P. S. Negi
2011-07-05T23:59:59.000Z
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 Field-Programmable Analog Array for high frequency OTA-C filters
Nuniz, Joseph Anthony
1994-01-01T23:59:59.000Z
specified frequency range. Such a FPAA would be ideal for prototyping analog circuits and off-theshelf analog filters. This thesis deals with the design, development and difficulties involved in building such a FPAA targeted towards high frequency...
Liu Yongxin; Zhang Quanzhi; Liu Jia; Song Yuanhong; Wang Younian [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Bogaerts, Annemie [Department of Chemistry, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk-Antwerp (Belgium)
2012-09-10T23:59:59.000Z
The electron bounce resonance heating (BRH) in dual-frequency capacitively coupled plasmas operated in oxygen and argon has been studied by different experimental methods. In comparison with the electropositive argon discharge, the BRH in an electronegative discharge occurs at larger electrode gaps. Kinetic particle simulations reveal that in the oxygen discharge, the bulk electric field becomes quite strong and is out of phase with the sheath field. Therefore, it retards the resonant electrons when traversing the bulk, resulting in a suppressed BRH. This effect becomes more pronounced at lower high-frequency power, when the discharge mode changes from electropositive to electronegative.
Crane, Randolph W.; Marts, Donna J.
1994-11-01T23:59:59.000Z
An electromagnetic fastener for manipulating objects in space uses the matic attraction of various metals. An end effector is attached to a robotic manipulating system having an electromagnet such that when current is supplied to the electromagnet, the object is drawn and affixed to the end effector, and when the current is withheld, the object is released. The object to be manipulated includes a multiplicity of ferromagnetic patches at various locations to provide multiple areas for the effector on the manipulator to become affixed to the object. The ferromagnetic patches are sized relative to the object's geometry and mass.
Crane, Randolph W. (Idaho Falls, ID); Marts, Donna J. (Idaho Falls, ID)
1994-01-01T23:59:59.000Z
An electromagnetic fastener for manipulating objects in space uses the matic attraction of various metals. An end effector is attached to a robotic manipulating system having an electromagnet such that when current is supplied to the electromagnet, the object is drawn and affixed to the end effector, and when the current is withheld, the object is released. The object to be manipulated includes a multiplicity of ferromagnetic patches at various locations to provide multiple areas for the effector on the manipulator to become affixed to the object. The ferromagnetic patches are sized relative to the object's geometry and mass.
Susceptibility study of audio recording devices to electromagnetic stimulations
Halligan, Matthew S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grant, Steven L. [Missouri Univ. of Science and Technology, Rolla, MO (United States); Beetner, Daryl G. [Missouri Univ. of Science and Technology, Rolla, MO (United States)
2014-02-01T23:59:59.000Z
Little research has been performed to study how intentional electromagnetic signals may couple into recording devices. An electromagnetic susceptibility study was performed on an analog tape recorder, a digital video camera, a wired computer microphone, and a wireless microphone system to electromagnetic interference. Devices were subjected to electromagnetic stimulations in the frequency range of 1-990 MHz and field strengths up to 4.9 V/m. Carrier and message frequencies of the stimulation signals were swept, and the impacts of device orientation and antenna polarization were explored. Message signals coupled into all devices only when amplitude modulated signals were used as stimulation signals. Test conditions that produced maximum sensitivity were highly specific to each device. Only narrow carrier frequency ranges could be used for most devices to couple messages into recordings. A basic detection technique using cross-correlation demonstrated the need for messages to be as long as possible to maximize message detection and minimize detection error. Analysis suggests that detectable signals could be coupled to these recording devices under realistic ambient conditions.
Electromagnetic Signals from Bacterial DNA
A. Widom; J. Swain; Y. N. Srivastava; S. Sivasubramanian
2012-02-09T23:59:59.000Z
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.
Melamed, Timor
Progress In Electromagnetics Research, Vol. 114, 317332, 2011 PULSED BEAM EXPANSION-based pulsed-beams expansion of planar aperture time- dependent electromagnetic fields. The propagating field-beam waveobjects over the frame spectral lattice. Explicit asymptotic expressions for the electromagnetic pulsed
Some Wave Equations for Electromagnetism and Gravitation
Zi-Hua Weng
2010-08-11T23:59:59.000Z
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.
Electromagnetics from Simulation to Optimal Design
Grohs, Philipp
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
611: Electromagnetic Theory Problem Sheet 5
Pope, Christopher
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
611: Electromagnetic Theory Problem Sheet 6
Pope, Christopher
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
Liou, S. P.; Aguiar, D.
1999-01-01T23:59:59.000Z
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...
Taieb, C.; Blanc, M.
1981-08-01T23:59:59.000Z
We analyze three-dimensional ion drift data from the Saint-Santin incoherent scatter facility to test experimentally the theoretical description of ion transport in the ionospheric dynamo layer, and to deduce electric fields and ion neutral collision frequencies from the observed drifts. Using a geometrical representation of the ion momentum equation, we show that at middle latitudes, because horizontal neutral wind influences ion motions both parallel and orthogonal to the field lines in the ionospheric dynamo layer, the information contained in a three-dimensional ion drift measurement is redundant, thus permitting to check the standard theoretical description of ionospheric electrodynamics in two ways. First, assuming a model ion-neutral collision frequency profile, one can deduce the north-south perpendicular component of the electric field function of height in the E region from Saint-Santin drift data. We find that its altitude variations remain within the experimental uncertainty of the method, in agreement with the theoretical assumption of equipotential field lines. Second, assuming that the electric field is constant in altitude, one can determine the ion collision ratio, or ratio of the ion collision frequency to the ion gyrofrequency, from a comparison of E and F region drift measurements. Daily median values of the ion collision frequencies, thus obtained for each of the three seasons, are found to compare reasonably well with ion collision frequencies derived from the Jacchia neutral atmosphere model for the case of the equinox sample, but determinations for the other seasons are contaminated by a high level of measurement noise.
Space-time Curvature of Classical Electromagnetism
R. W. M. Woodside
2004-10-08T23:59:59.000Z
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.
Ando, A.; Matsuno, T.; Funaoi, T.; Tanaka, N. [School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Tsumori, K.; Takeiri, Y. [National Institute for Fusion Science, Toki 509-5292 (Japan)
2012-02-15T23:59:59.000Z
H{sup -} beam was successfully extracted from a cesium seeded ion source operated using a field effect transistor inverter power supply as a radio frequency (RF) wave source. High density hydrogen plasma more than 10{sup 19} m{sup -3} was obtained using an external type antenna with RF frequency of lower than 0.5 MHz. The source was isolated by an isolation transformer and H{sup -} ion beam was extracted from a single aperture. Acceleration current and extraction current increased with the increase of extraction voltage. Addition of a small amount of cesium vapor into the source enhanced the currents.
Kais, Sabre
in high-frequency super-intense laser fields Ross D. Hoehn, Jiaxiang Wang, and Sabre Kais Citation-intense laser fields Ross D. Hoehn,1 Jiaxiang Wang,2 and Sabre Kais1,a) 1 Departments of Chemistry and Physics
Pérez, E A Coello
2015-01-01T23:59:59.000Z
We present a model-independent approach to electric quadrupole transitions of deformed nuclei. Based on an effective theory for axially symmetric systems, the leading interactions with electromagnetic fields enter as minimal couplings to gauge potentials, while subleading corrections employ gauge-invariant non-minimal couplings. This approach yields transition operators that are consistent with the Hamiltonian, and the power counting of the effective theory provides us with theoretical uncertainty estimates. We successfully test the effective theory in homonuclear molecules that exhibit a large separation of scales. For ground-state band transitions of rotational nuclei, the effective theory describes data well within theoretical uncertainties at leading order. In order to probe the theory at subleading order, data with higher precision would be valuable. For transitional nuclei, next-to-leading order calculations and the high-precision data are consistent within the theoretical uncertainty estimates. We also...
High-Field DNP and ENDOR with a Novel Multiple-Frequency Resonance Structure
Griffin, Robert G.
cavity simultaneously acts as a NMR coil, allowing for increased efficiency of radiofrequency irradiation to radiation losses of the open structure (20). An application of this particular design at high W frequencies
Halgamuge, Malka N.
on exposure to electromagnetic have generated conflicting results both in epidemiological and laboratory for exposures to low-frequency magnetic fields in the mili-Tesla range. No resonance frequencies or amplitude about 10 micro-Tesla. The oscillating magnetic field is assumed to act on proteins together
DEF: The Physical Basis of Electromagnetic Propulsion
Pinheiro, Mario J
2015-01-01T23:59:59.000Z
The very existence of the physical vacuum provides a framework to propose a general mechanism for propelling bodies through an agency of electromagnetic fields, that seat in that medium. When two sub-systems of a general closed device interact via nonlocal and retarded electromagnetic pulses, it is easily shown that they give a nonzero force, and that only tend to comply with the action-to-reaction force in the limit of instantaneous interactions. The arrangement of sub-systems provide a handy way to optimize the unbalanced EM force with the concept of impedance matching. The general properties of the differential electromagnetic force (DEF) are the following: i) it is proportional to the square of the intensity and to the angular wave frequency $\\omega$; ii) to the space between the sub-systems (although in a non-linear manner); iii) it is inversely proportional to the speed of interaction; iv) when the two sub-systems are out-of-phase, DEF is null. The approach is of interest to practical engineering princi...
Frequency-Selective Near-Field Radiative Heat Transfer between Photonic Crystal Slabs-selective near-field radiative heat transfer between patterned (photonic-crystal) slabs at designable frequencies and separations, exploiting a general numerical approach for computing heat transfer in arbitrary geometries
Shear driven electromagnetic drift-waves in a nonuniform dense magnetoplasma
Tariq, Sabeen; Mirza, Arshad M. [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Masood, Waqas [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad 44000 (Pakistan); National Center for Physics (NCP), Islamabad 44000 (Pakistan)
2011-08-15T23:59:59.000Z
Linear characteristic properties of high- and low-frequency (in comparison with the cyclotron frequency) electromagnetic drift-waves are studied in a nonuniform, dense magnetoplasma (composed of electrons and ions), in the presence of parallel (magnetic field-aligned) velocity shear, by using quantum magnetohydrodynamic model. By applying the drift-approximation (viz., |{partial_derivative} {sub t}|<<{omega}{sub ci}<<{omega}{sub ce}) to the quantum momentum equations, together with the continuity equations and the Poisson equation, we derive the governing equations for electromagnetic drift-waves with the shear flow. These linear equations are then Fourier transformed to obtain the dispersion relation in both high-frequency and low-frequency regimes. The dispersion relations are then discussed under various limiting cases.
Laser measurement of H{sup -} ions in a field-effect-transistor based radio frequency ion source
Tanaka, N.; Matsuno, T.; Funaoi, T.; Ando, A. [Tohoku University, Aramaki 6-6-05, Aoba, Sendai, Miyagi 980-8579 (Japan); Tauchi, Y. [Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611 (Japan); Nakano, H.; Tsumori, K.; Takeiri, Y. [National Institute for Fusion Science, Oroshi-Cho 322-6, Toki, Gifu 509-5292 (Japan)
2012-02-15T23:59:59.000Z
Hydrogen negative ion density measurements are required to clarify the characteristics of negative ion production and ion source performance. Both of laser photodetachment and cavity ring down (CRD) measurements have been implemented to a field-effect-transistor based radio-frequency ion source. The density ratio of negative hydrogen ions to electrons was successfully measured by laser photodetachment and effect of magnetic filter field on negative ion density was confirmed. The calculated CRD signal showed that CRD mirrors with >99.990% reflectivity are required and loss of reflectivity due to cesium contamination should be minimized.
611: Electromagnetic Theory Problem Sheet 4
Pope, Christopher
611: Electromagnetic Theory Problem Sheet 4 (1a) The angular momentum 3-vector L is defined by Li) Prove from the above that for the electromagnetic field, L = 1 4 r × (E × B) d3 x (b) Prove that dR dt = P E where R is the centre of mass of the electromagnetic field, defined by R Wd3x = rWd3x
Judd D. Bowman; David G. Barnes; Frank H. Briggs; Brian E. Corey; Merv J. Lynch; N. D. Ramesh Bhat; Roger J. Cappallo; Sheperd S. Doeleman; Brian J. Fanous; David Herne; Jacqueline N. Hewitt; Chris Johnston; Justin C. Kasper; Jonathon Kocz; Eric Kratzenberg; Colin J. Lonsdale; Miguel F. Morales; Divya Oberoi; Joseph E. Salah; Bruce Stansby; Jamie Stevens; Glen Torr; Randall Wayth; Rachel L. Webster; J. Stuart B. Wyithe
2006-12-01T23:59:59.000Z
Experiments were performed with prototype antenna tiles for the Mileura Widefield Array--Low Frequency Demonstrator (MWA-LFD) to better understand the widefield, wideband properties of their design and to characterize the radio frequency interference (RFI) between 80 and 300 MHz at the site in Western Australia. Observations acquired during the six month deployment confirmed the predicted sensitivity of the antennas, sky-noise dominated system temperatures, and phase-coherent interferometric measurements. The radio spectrum is remarkably free of strong terrestrial signals, with the exception of two narrow frequency bands allocated to satellite downlinks and rare bursts due to ground-based transmissions being scattered from aircraft and meteor trails. Results indicate the potential of the MWA-LFD to make significant achievements in its three key science objectives: epoch of reionziation science, heliospheric science, and radio transient detection.
Geometric and Electromagnetic Aspects of Fusion Pore Making
Darya Apushkinskaya; Evgeny Apushkinsky; Bernhelm Booss-Bavnbek; Martin Koch
2010-04-29T23:59:59.000Z
For regulated exocytosis, we model the morphology and dynamics of the making of the fusion pore or porosome as a cup-shaped lipoprotein structure (a dimple or pit) on the cytosol side of the plasma membrane. We describe the forming of the dimple by a free boundary problem. We discuss the various forces acting and analyze the magnetic character of the wandering electromagnetic field wave produced by intracellular spatially distributed pulsating (and well observed) release and binding of calcium ions anteceding the bilayer membrane vesicle fusion of exocytosis. Our approach explains the energy efficiency of the observed dimple forming prior to hemifusion and fusion pore, and the observed flickering in secretion. It provides a frame to relate characteristic time length of exocytosis to the frequency, amplitude and direction of propagation of the underlying electromagnetic field wave.
Load flow studies in the presence of magnetohydrodynamic electromagnetic pulse
Kruse, V.J.; Rackliffe, G.B. (Westinghouse Electric Corp., Pittsburgh, PA (USA). Advanced Systems Technology Div.); Barnes, P.R. (Oak Ridge National Lab., TN (USA))
1990-04-01T23:59:59.000Z
Seconds after a high-altitude nuclear event, the earth's surface experiences a very low-frequency, quasi-DC magnetohydrodynamic electromagnetic field (MHD-EMP). MHD-EMP fields impress quasi-DC currents on transmission and sub-transmission lines. These current magnitudes can exceed several times the transformer exciting current levels. Transformers and shunt reactors experience severe half-cycle saturation resulting in harmonics and increased VAR demand. This paper reviews the calculation of the quasi-dc currents, discusses the calculation of the increased var demand, and evaluates the effect of a simulated MHD-EMP event on a power system with stability and load flow analyses.
Gravitation and electromagnetism
V. P. Dmitriyev
2002-07-23T23:59:59.000Z
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.
Aldridge, David F.
2014-11-01T23:59:59.000Z
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.
Shrekenhamer, Abraham
1975-01-01T23:59:59.000Z
by means of optical fibers to eliminate perturbation of the measured electric field. The instrument utilizes the phenomenon of charge induction in con- ductors in the presence of an electric field. The charge induced on the exterior of the probe... conceptual circuit for electric field to analog voltage conversion. . 29 15 Induced-charge to analog-voltage converter. . . 35 16 Probe component layout . 36 17 Axis selector, optoelectronic converter and battery switching circuits. 18 Receiver...
Kubo, Takayuki
2014-01-01T23:59:59.000Z
The field limit of superconducting radio-frequency cavity made of type II superconductor with a large Ginzburg-Landau parameter is studied with taking effects of nano-scale surface topography into account. If the surface is ideally flat, the field limit is imposed by the superheating field. On the surface of cavity, however, nano-defects almost continuously distribute and suppress the superheating field everywhere. The field limit is imposed by an effective superheating field given by the product of the superheating field for ideal flat surface and a suppression factor that contains effects of nano-defects. A nano-defect is modeled by a triangular groove with a depth smaller than the penetration depth. An analytical formula for the suppression factor of bulk and multilayer superconductors are derived in the framework of the London theory. As an immediate application, the suppression factor of the dirty Nb processed by the electropolishing is evaluated by using results of surface topographic study. The estimat...
A Field-Programmable Analog Array for high frequency OTA-C filters
Nuniz, Joseph Anthony
1994-01-01T23:59:59.000Z
programmable specification OTA are presented. Based on the simulation and fabricated results, the fea sibility of the field-programmable analog array for designing analog systems was demonstrated....
McDonald, Kirk
than the retarded forms of the Coulomb and the BiotSavart laws. Of course, it was Maxwell who first of the Coulomb and BiotSavart laws as their leading terms, but their relation to radiation is not as manifest greater emphasis to the radiation fields. This article presents a derivation of the various expressions
DERIVATION OF THE MAGNETIC FIELD IN A CORONAL MASS EJECTION CORE VIA MULTI-FREQUENCY RADIO IMAGING
Tun, Samuel D. [The Naval Research Laboratory, Washington, DC 20375 (United States)] [The Naval Research Laboratory, Washington, DC 20375 (United States); Vourlidas, A. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)] [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)
2013-04-01T23:59:59.000Z
The magnetic field within the core of a coronal mass ejection (CME) on 2010 August 14 is derived from analysis of multi-wavelength radio imaging data. This CME's core was found to be the source of a moving type IV radio burst, whose emission is here determined to arise from the gyrosynchrotron process. The CME core's true trajectory, electron density, and line-of-sight depth are derived from stereoscopic observations, constraining these parameters in the radio emission models. We find that the CME carries a substantial amount of mildly relativistic electrons (E < 100 keV) in a strong magnetic field (B < 15 G), and that the spectra at lower heights are preferentially suppressed at lower frequencies through absorption from thermal electrons. We discuss the results in light of previous moving type IV burst studies, and outline a plan for the eventual use of radio methods for CME magnetic field diagnostics.
Small, high frequency probe for internal magnetic field measurements in high temperature plasmas
Washington at Seattle, University of
temperature 50 eV , high density ( 1020 m 3 ) plasmas such as the field-reversed configuration FRC , it has eV , high density ( 1020 m 3 ) plasmas such as the field-reversed configuration FRC , it has be exposed to the plasma. An estimate of the limiting probe size for the FRC can be obtained from
Poynting-vector based method for determining the bearing and location of electromagnetic 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
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.
Kaur, Sukhdeep; Sharma, A. K. [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi 110016 (India); Salih, Hyder A. [Department of Applied Sciences, University of Baghdad, Baghdad (Iraq)
2009-04-15T23:59:59.000Z
Second harmonic generation of a right circularly polarized Gaussian electromagnetic beam in a magnetized plasma is investigated. The beam causes Ohmic heating of electrons and subsequent redistribution of the plasma, leading to self-defocusing. The radial density gradient, in conjunction with the oscillatory electron velocity, produces density oscillation at the wave frequency. The density oscillation beats with the oscillatory velocity to produce second harmonic current density, giving rise to resonant second harmonic radiation when the wave frequency is one-third of electron cyclotron frequency. The second harmonic field has azimuthal dependence as exp(i{theta}). The self-defocusing causes a reduction in the efficiency of harmonic generation.
Measuring Instantaneous Frequency of Local Field Potential Oscillations using the Kalman Smoother
Nguyen, David P.
Rhythmic local field potentials (LFPs) arise from coordinated neural activity. Inference of neural function based on the properties of brain rhythms remains a challenging data analysis problem. Algorithms that characterize ...
Authors A. L. Barabanov; R. Golub; S. K. Lamoreaux
2006-07-17T23:59:59.000Z
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.
Gray, L.J.; Morris, M.D.; Semeraro, B.D. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Cooper, E. [Computer Application Systems, Inc., Chattanooga, TN (United States)
1996-09-30T23:59:59.000Z
Computer Application Systems, Inc. is currently developing a capciflector sensor for a variety of commercial applications, e.g., object detection in robotics. The goal of this project was to create computational tools for simulating the performance of this device. The role of modeling is to provide a quantitative understanding of how the sensor works, and to assist in designing optimal sensor configurations for specific applications. A two-dimensional boundary integral code for determining the electric field was constructed, and a novel algorithm for solving the inverse design problem was investigated. Parallel implementation of the code, which will be required for detailed three-dimensional analysis, was also investigated.
Zheludev, Nikolay
Fiber optic probe of free electron evanescent fields in the optical frequency range Jin-Kyu So fabrication of bent near-field optical fiber probes by electric arc heating Rev. Sci. Instrum. 69, 3843 (1998 of thermal evaporation conditions used in coating aluminum on near-field fiber-optic probes Rev. Sci. Instrum
Electromagnetic radiation from a plasma slab during the development of Weibel instability
Vagin, K. Yu.; Romanov, A. Yu.; Uryupin, S. A. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)
2012-01-15T23:59:59.000Z
Electromagnetic radiation from an anisotropic plasma slab formed by ionization of matter in the field of a high-power femtosecond pulse is studied. It is shown that the growth of initial field perturbations in the course of Weibel instability is accompanied by the generation of nonmonochromatic radiation with a characteristic frequency on the order of the instability growth rate. It is found that perturbations with characteristic scale lengths less than or on the order of the ratio of the speed of light to the Langmuir frequency are excited and radiated most efficiently, provided that the slab is thicker than this ratio.
Mathematical Methods for Electromagnetic and Optical Waves1
Lu, Ya Yan
Mathematical Methods for Electromagnetic and Optical Waves1 Ya Yan Lu Department of Mathematics . . . . . . . . . . . . . . . . . . . . . . 5 1.6 The energy law of electromagnetic field . . . . . . . . . . . . . . . . . . . . . 7 2.5 Pulse propagation and temporal solitons . . . . . . . . . . . . . . . . . . . . . 70 2 #12;Chapter 1
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
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.
E. A. Coello Pérez; T. Papenbrock
2015-07-16T23:59:59.000Z
We present a model-independent approach to electric quadrupole transitions of deformed nuclei. Based on an effective theory for axially symmetric systems, the leading interactions with electromagnetic fields enter as minimal couplings to gauge potentials, while subleading corrections employ gauge-invariant non-minimal couplings. This approach yields transition operators that are consistent with the Hamiltonian, and the power counting of the effective theory provides us with theoretical uncertainty estimates. We successfully test the effective theory in homonuclear molecules that exhibit a large separation of scales. For ground-state band transitions of rotational nuclei, the effective theory describes data well within theoretical uncertainties at leading order. In order to probe the theory at subleading order, data with higher precision would be valuable. For transitional nuclei, next-to-leading order calculations and the high-precision data are consistent within the theoretical uncertainty estimates. We also study the faint inter-band transitions within the effective theory and focus on the $E2$ transitions from the $0^+_2$ band (the "$\\beta$ band") to the ground-state band. Here, the predictions from the effective theory are consistent with data for several nuclei, thereby proposing a solution to a long-standing challenge.
E. A. Coello Pérez; T. Papenbrock
2015-02-16T23:59:59.000Z
We present a model-independent approach to electric quadrupole transitions of deformed nuclei. Based on an effective theory for axially symmetric systems, the leading interactions with electromagnetic fields enter as minimal couplings to gauge potentials, while subleading corrections employ gauge-invariant non-minimal couplings. This approach yields transition operators that are consistent with the Hamiltonian, and the power counting of the effective theory provides us with theoretical uncertainty estimates. We successfully test the effective theory in homonuclear molecules that exhibit a large separation of scales. For ground-state band transitions of rotational nuclei, the effective theory describes data well within theoretical uncertainties at leading order. In order to probe the theory at subleading order, data with higher precision would be valuable. For transitional nuclei, next-to-leading order calculations and the high-precision data are consistent within the theoretical uncertainty estimates. We also study the faint inter-band transitions within the effective theory and focus on the $E2$ transitions from the $0^+_2$ band (the $\\beta$ band) to the ground-state band. Here, the predictions from the effective theory are consistent with data for several nuclei, thereby proposing a solution to a long-standing challenge.
Electromagnetic wave scattering by Schwarzschild black holes
Luís C. B. Crispino; Sam R. Dolan; Ednilton S. Oliveira
2009-05-20T23:59:59.000Z
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.
Very high frequency GaAlAs laser field-effect transistor monolithic integrated circuit
Ury, I.; Lau, K.Y.; Bar-Chaim, N.; Yariv, A.
1982-07-15T23:59:59.000Z
A very low threshold GaAlAs buried heterostructure laser has been monolithically integrated with a recessed structure metal-semiconductor field-effect transistor on a semi-insulating substrate. At cw operation, the device has a direct modulation bandwidth of at least 4 GHz.
There are numerous laboratory and field examples in which low-frequency
Korneev, Valeri A.
reservoir (marked Ju0, the cracked shale reservoir) is represented by 15-20 m thick fractured shale contains the most important information about the reservoir. Let us consider three examples of field data processing. In all of them, the hydrocarbon-rich zones of the reservoir were localized using low
Sananikone, Khamla
1998-01-01T23:59:59.000Z
A transient controlled-source electromagnetic (TDEM) survey has been performed at the Texas A&M University Hydrogeological Test Site adjacent to the Brazos River in Burleson County, Texas. A I-D regularized inversion of the data shows...
Electromagnetically induced transparency in mechanical effects of light
Agarwal, G. S.; Huang, Sumei [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)
2010-04-15T23:59:59.000Z
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.
Ultimate Energy Densities for Electromagnetic Pulses
Mankei Tsang
2008-03-06T23:59:59.000Z
The ultimate electric and magnetic energy densities that can be attained by bandlimited electromagnetic pulses in free space are calculated using an ab initio quantized treatment, and the quantum states of electromagnetic fields that achieve the ultimate energy densities are derived. The ultimate energy densities also provide an experimentally accessible metric for the degree of localization of polychromatic photons.
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
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.
Alternative expression for the electromagnetic Lagrangian
Saldanha, Pablo L
2015-01-01T23:59:59.000Z
We propose an alternative expression for the Lagrangian density that governs the interaction of a charged particle with external electromagnetic fields. The proposed Lagrangian is written in terms of the local superposition of the particle fields with the applied electromagnetic fields, not in terms of the particle charge and of the electromagnetic potentials as is usual. The total Lagrangian for a set of charged particles assumes a simple elegant form with the alternative formulation, giving an aesthetic support for it. The proposed Lagrangian is equivalent to the traditional one in their domain of validity and provides an interesting description of the Aharonov-Bohm effect.
Shrekenhamer, Abraham
1975-01-01T23:59:59.000Z
) Substituting from (1. 4) into (1. 5) [4: p. 45] yields p V VU= ?? C (1. 6a) or (1. 6b) This is known as Poisson's equation. For the special case of charge- free space p = 0 and VV=0 (1 7) Eq. (1. 7) is known as Laplace's equation, a second order...) dt = q (t) = ks E (t) dS (1. 19) D For the cubical geometry: 11 f i (t)dt = ks E dS z z Z face (1. 20) Let E denote the average electric field over the z face. Then z f 2 i (t)dt = kE sJ dS ~skE a z z z Z face (1. 21) where a is the cube...
Electromagnetism on Anisotropic Fractals
Martin Ostoja-Starzewski
2011-06-08T23:59:59.000Z
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.
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
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.
Furuta, Masaki, E-mail: furutam@mail.tagen.tohoku.ac.jp; Okamoto, Satoshi; Kikuchi, Nobuaki; Kitakami, Osamu [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Shimatsu, Takehito [Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578 (Japan); Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577 (Japan)
2014-04-07T23:59:59.000Z
We have studied the dot size dependence of microwave assisted magnetization switching (MAS) on perpendicular magnetic Co/Pt multilayer dot array. The significant microwave assistance effect has been observed over the entire dot size D ranging from 50?nm to 330?nm examined in the present study. The MAS behavior, however, critically depends on D. The excitation frequency dependence of the switching field is well consistent with the spin wave theory, indicating that the magnetization precession in MAS is in accordance with the well defined eigenmodes depending on the dot diameter. The lowest order spin wave is only excited for D???100?nm, and then the MAS effect is well consistent with that of the single macrospin prediction. On the other hand, higher order spin waves are excited for D?>?100?nm, giving rise to the significant enhancement of the MAS effect. The dispersion of MAS effect also depends on D and is significantly reduced for the region of D?>?100?nm. This significant reduction of the dispersion is attributed to the essential feature of the MAS effect which is insensitive to the local fluctuation of anisotropy field, such as defect, damaged layer, and so on.
Pulse homodyne field disturbance sensor
McEwan, T.E.
1997-10-28T23:59:59.000Z
A field disturbance sensor operates with relatively low power, provides an adjustable operating range, is not hypersensitive at close range, allows co-location of multiple sensors, and is inexpensive to manufacture. The sensor includes a transmitter that transmits a sequence of transmitted bursts of electromagnetic energy. The transmitter frequency is modulated at an intermediate frequency. The sequence of bursts has a burst repetition rate, and each burst has a burst width and comprises a number of cycles at a transmitter frequency. The sensor includes a receiver which receives electromagnetic energy at the transmitter frequency, and includes a mixer which mixes a transmitted burst with reflections of the same transmitted burst to produce an intermediate frequency signal. Circuitry, responsive to the intermediate frequency signal indicates disturbances in the sensor field. Because the mixer mixes the transmitted burst with reflections of the transmitted burst, the burst width defines the sensor range. The burst repetition rate is randomly or pseudo-randomly modulated so that bursts in the sequence of bursts have a phase which varies. A second range-defining mode transmits two radio frequency bursts, where the time spacing between the bursts defines the maximum range divided by two. 12 figs.
Pulse homodyne field disturbance sensor
McEwan, Thomas E. (Livermore, CA)
1997-01-01T23:59:59.000Z
A field disturbance sensor operates with relatively low power, provides an adjustable operating range, is not hypersensitive at close range, allows co-location of multiple sensors, and is inexpensive to manufacture. The sensor includes a transmitter that transmits a sequence of transmitted bursts of electromagnetic energy. The transmitter frequency is modulated at an intermediate frequency. The sequence of bursts has a burst repetition rate, and each burst has a burst width and comprises a number of cycles at a transmitter frequency. The sensor includes a receiver which receives electromagnetic energy at the transmitter frequency, and includes a mixer which mixes a transmitted burst with reflections of the same transmitted burst to produce an intermediate frequency signal. Circuitry, responsive to the intermediate frequency signal indicates disturbances in the sensor field. Because the mixer mixes the transmitted burst with reflections of the transmitted burst, the burst width defines the sensor range. The burst repetition rate is randomly or pseudo-randomly modulated so that bursts in the sequence of bursts have a phase which varies. A second range-defining mode transmits two radio frequency bursts, where the time spacing between the bursts defines the maximum range divided by two.
Objects of maximum electromagnetic chirality
Fernandez-Corbaton, Ivan
2015-01-01T23:59:59.000Z
We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. The upper bound is attained if and only if the object is transparent for fields of one handedness (helicity). Additionally, electromagnetic duality symmetry, i.e. helicity preservation upon scattering, turns out to be a necessary condition for reciprocal scatterers to attain the upper bound. We use these results to provide requirements for the design of such extremal scatterers. The requirements can be formulated as constraints on the polarizability tensors for dipolar scatterers or as material constitutive relations. We also outline two applications for objects of maximum electromagnetic chirality: A twofold resonantly enhanced and background free circular dichroism measurement setup, and angle independent helicity filtering glasses.
The Electromagnetic Green's Function for Layered Topological Insulators
Crosse, J A; Buhmann, Stefan Yoshi
2015-01-01T23:59:59.000Z
The dyadic Green's function of the inhomogeneous vector Helmholtz equation describes the field pattern of a single frequency point source. It appears in the mathematical description of many areas of electromagnetism and optics including both classical and quantum, linear and nonlinear optics, dispersion forces (such as the Casimir and Casimir-Polder forces) and in the dynamics of trapped atoms and molecules. Here, we compute the Green's function for a layered topological insulator. Via the magnetoelectric effect, topological insulators are able to mix the electric, E, and magnetic induction, B, fields and, hence, one finds that the TE and TM polarizations mix on reflection from/transmission through an interface. This leads to novel field patterns close to the surface of a topological insulator.
Cavity-output-field control via interference effects
Viorel Ciornea; Mihai A. Macovei
2014-10-25T23:59:59.000Z
We show how interference effects are responsible for manipulating the output electromagnetic field of an optical micro-resonator in the good-cavity limit. The system of interest consists in a moderately strongly pumped two-level emitter embedded in the optical cavity. When an additional weaker laser of the same frequency is pumping the combined system through one of the resonator's mirrors then the output cavity electromagnetic field can be almost completely suppressed or enhanced. This is due to the interference among the scattered light by the strongly pumped atom into the cavity mode and the incident weaker laser field. The result applies to photonic crystal environments as well.
Oganesyan, David L; Vardanyan, Aleksandr O; Oganesyan, G D
2013-06-30T23:59:59.000Z
Difference-frequency generation in a GaAs crystal with a periodic domain structure in the field of a few-cycle laser pulse is considered for the case of weakly pronounced material dispersion. The straight-line method is used to solve numerically the system of coupled nonlinear partial differential equations describing the evolution of the electric field of this laser pulse in GaAs crystals with periodic and chirped domain structures. It is shown that application of a GaAs crystal with a chirped domain structure makes it possible to control the frequency-modulation law for a broadband differencefrequency pulse. (nonlinear optical phenomena)
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
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.
Electromagnetic properties of neutrinos
Carlo Giunti; Alexander Studenikin
2010-06-08T23:59:59.000Z
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.
Investigation of electromagnetic welding
Pressl, Daniel G. (Daniel Gerd)
2009-01-01T23:59:59.000Z
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 ...
Son, Sang-Kil; Chu, Shih-I
2008-06-05T23:59:59.000Z
.07#3;?8#4; 2.92 2.41#3;?3#4; 2.92 1.33#3;?6#4; 2.92 2.01#3;?3#4; 5.00 4.53#3;?20#4; 4.91 3.42#3;?12#4; 5.00 6.62#3;?15#4; 4.93 3.39#3;?10#4; 5.00 1.28#3;?12#4; 4.94 2.07#3;?9#4; 7.02 1.99#3;?28#4; 6.92 1.83#3;?20#4; 7.00 3.10#3;?21#4; 6.93 1.82#3;?16#4; 7.00 4...Many-mode Floquet theoretical approach for coherent control of multiphoton dynamics driven by intense frequency-comb laser fields Sang-Kil Son (???#1;1,* and Shih-I Chu (???#1;1,2,† 1Department of Chemistry, University of Kansas, Lawrence, Kansas...
Control of the Lamb shift by a driving field
Yang, Shuai; Zheng, Hang; Hong, Ran; Zhu, Shi-Yao; Zubairy, M. Suhail
2010-01-01T23:59:59.000Z
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...
Khomitsky, D V
2011-01-01T23:59:59.000Z
An expansion of the nearly free-electron model constructed by Frantzeskakis, Pons and Grioni [Phys. Rev. B {\\bf 82}, 085440 (2010)] describing quantum states at Bi/Si(111) interface with giant spin-orbit coupling is developed and applied for the band structure and spin polarization calculation, as well as for the linear response analysis for charge current and induced spin caused by dc field and by electromagnetic radiation. It is found that the large spin-orbit coupling in this system may allow resolving the spin-dependent properties even at room temperature and at realistic collision rate. The geometry of the atomic lattice combined with spin-orbit coupling leads to an anisotropic response both for current and spin components related to the orientation of the external field. The in-plane dc electric field produces only the in-plane components of spin in the sample while both the in-plane and out-of-plane spin components can be excited by normally propagating electromagnetic wave with different polarizations...
D. V. Khomitsky
2011-05-21T23:59:59.000Z
An expansion of the nearly free-electron model constructed by Frantzeskakis, Pons and Grioni [Phys. Rev. B {\\bf 82}, 085440 (2010)] describing quantum states at Bi/Si(111) interface with giant spin-orbit coupling is developed and applied for the band structure and spin polarization calculation, as well as for the linear response analysis for charge current and induced spin caused by dc field and by electromagnetic radiation. It is found that the large spin-orbit coupling in this system may allow resolving the spin-dependent properties even at room temperature and at realistic collision rate. The geometry of the atomic lattice combined with spin-orbit coupling leads to an anisotropic response both for current and spin components related to the orientation of the external field. The in-plane dc electric field produces only the in-plane components of spin in the sample while both the in-plane and out-of-plane spin components can be excited by normally propagating electromagnetic wave with different polarizations.
Ryu, S.K.; Kim, Y.K.; Kim, M.K.; Won, S.H. [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea); Chung, S.H. [Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)
2010-01-15T23:59:59.000Z
The oscillation behavior of laminar lifted flames under the influence of low-frequency AC has been investigated experimentally in coflow jets. Various oscillation modes were existed depending on jet velocity and the voltage and frequency of AC, especially when the AC frequency was typically smaller than 30 Hz. Three different oscillation modes were observed: (1) large-scale oscillation with the oscillation frequency of about 0.1 Hz, which was independent of the applied AC frequency, (2) small-scale oscillation synchronized to the applied AC frequency, and (3) doubly-periodic oscillation with small-scale oscillation embedded in large-scale oscillation. As the AC frequency decreased from 30 Hz, the oscillation modes were in the order of the large-scale oscillation, doubly-periodic oscillation, and small-scale oscillation. The onset of the oscillation for the AC frequency smaller than 30 Hz was in close agreement with the delay time scale for the ionic wind effect to occur, that is, the collision response time. Frequency-doubling behavior for the small-scale oscillation has also been observed. Possible mechanisms for the large-scale oscillation and the frequency-doubling behavior have been discussed, although the detailed understanding of the underlying mechanisms will be a future study. (author)
Electromagnetic space-time crystals. II. Fractal computational approach
G. N. Borzdov
2014-10-20T23:59:59.000Z
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.
Electromagnetic Abdulaziz Hanif
Masoudi, Husain M.
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
Electromagnetic Measurements at RHIC
Hamagaki, Hideki
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
Electromagnetic Wave Dynamics in
Kaiser, Robin
Mesoscopic Electromagnetic Wave Dynamics in Ultracold Atomic Gases Robin Kaiser and Mark D. Havey Mesoscopic Electromagnetic Wave Dynamics in Ultracold Atomic Gases #12;39 E xperimental developments permit in the transport proper- ties of electromagnetic radiation in strongly scattering random media. Even in weakly
Electromagnetic Measurements at RHIC
Hamagaki, Hideki
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
The electromagnetic spike solutions
Ernesto Nungesser; Woei Chet Lim
2013-09-28T23:59:59.000Z
The aim of this paper is to use the existing relation between polarized electromagnetic Gowdy spacetimes and vacuum Gowdy spacetimes to find explicit solutions for electromagnetic spikes by a procedure which has been developed by one of the authors for gravitational spikes. We present new inhomogeneous solutions which we call the EME and MEM electromagnetic spike solutions.
Watkins, Jeffrey Paul
1984-01-01T23:59:59.000Z
of intramolecular and intermolecular crosslinking, 1, 5, 9, 10 When a tendon is injured the repair process is similar to that which occurs in other connective tissues. A wound module is formed consisting of 6 inflammatory cells, fibroblasts, and capillaries... Histologic section from PSW 12 SDF tendon defect 29 13 Histologic section from PSW 24 SDF tendon defect 30 14 Self-contained electromagnetic coil 42 FIGURE Page 15 Treatment (L) and control (R) limbs show similar increases in diameter of SDF tendon...
High Spin Co(I): High-Frequency and -Field EPR Spectroscopy of CoX(PPh3)3 (X = Cl, Br)
McQuade, D. Tyler
High Spin Co(I): High-Frequency and -Field EPR Spectroscopy of CoX(PPh3)3 (X = Cl, Br) J. Krzystek Supporting Information ABSTRACT: The previously reported pseudotetrahedral Co(I) complexes, CoX(PR3)3, where is uncommon for Co(I), although expected for this geometry. Described here are studies using electronic
Electromagnetic waves, gravitational coupling and duality analysis
E. M. C. Abreu; C. Pinheiro; S. A. Diniz; F. C. Khanna
2005-10-27T23:59:59.000Z
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.
Direct visualization of terahertz electromagnetic waves in classic experimental geometries
Werley, Christopher Alan
2012-01-01T23:59:59.000Z
We used newly developed experimental methods to collect educational video clips of electromagnetic waves propagating at the speed of light. The terahertz frequency waves were generated and detected in LiNbO3 crystals ...
Scalar and Electromagnetic Quasinormal modes of Extended black hole in F(R) gravity
Saneesh Sebastian; V. C. Kuriakose
2014-08-05T23:59:59.000Z
In this paper we study the scalar and electromagnetic perturbations of an extended black hole in F(R) gravity. The quasinormal modes in two cases are evaluated and studied their behavior by plotting graphs in each case. To study the quasinormal mode, we use the third order WKB method. The present study shows that the absolute value of imaginary part of complex quasinormal modes increases in both cases, thus the black hole is stable against these perturbations. As the mass of the scalar field increases the imaginary part of the frequency decreases. Thus damping slows down with increasing mass of the scalar field.
Electro-Optical Sensing Apparatus and Method for Characterizing Free-Space Electromagnetic Radiation
Zhang, Xi-Cheng; Libelo, Louis Francis; Wu, Qi
1999-09-14T23:59:59.000Z
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.
Interaction of biological systems with static and ELF electric and magnetic fields
Anderson, L.E.; Kelman, B.J.; Weigel, R.J. (eds.)
1987-01-01T23:59:59.000Z
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.
Extremely high frequency RF effects on electronics.
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
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.
Velocity damper for electromagnetically levitated materials
Fox, Richard J. (Oak Ridge, TN)
1994-01-01T23:59:59.000Z
A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material. 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.
Velocity damper for electromagnetically levitated materials
Fox, R.J.
1994-06-07T23:59:59.000Z
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.
On the Axioms of Topological Electromagnetism
D. H. Delphenich
2003-12-14T23:59:59.000Z
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.
Spinors and pre-metric electromagnetism
David Delphenich
2005-12-22T23:59:59.000Z
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.
Method and apparatus for upshifting light frequency by rapid plasma creation
Dawson, John M. (Pacific Palisades, CA); Wilks, Scott C. (Santa Monica, CA); Mori, Warren B. (Hermosa Beach, CA); Joshi, Chandrasekhar J. (Santa Monica, CA); Sessler, Andrew M. (Oakland, CA)
1990-01-01T23:59:59.000Z
Photons of an electromagnetic source wave are frequency-upshifted as a plasma is rapidly created around the path of this propagating source wave. The final frequency can be controlled by adjusting the gas density. A controlled time-varying frequency (chirped) pulse can be produced by using a controlled spatially varying gas density. The plasma must be created in a time which is short compared to the transit time of the light through the plasmas region. For very fast creation over one to at most a few light periods of an overdense plasma, static magnetic fields with short wavelengths are created.
Frequency-doubled scattering of symmetry-breaking surface-state electrons on liquid Helium
Miao Zhang; Wenzhi Jia; Lianfu Wei
2013-03-18T23:59:59.000Z
Any systems with symmetry-breaking eigenstates can effectively radiate photons with doubled frequency of the incident light, which is known as the second harmonic generation. Here, we study the second-order nonlinear effects with the system of surface-state electrons on liquid Helium. Due to the symmetry-breaking eigenstates, we show that a Rabi oscillation between two levels of the surface-state electrons can be realized beyond the usual resonant driving. Consequently, an electromagnetic field with the doubled frequency of the applied driving could be effectively radiated. This can be regarded as a frequency-doubled fluorescence, and interestingly, it works in the unusual Terahertz range.
Radio Science, Volume ???, Number , Pages 110, Time Reversal of Electromagnetic Waves and
Paris 7 - Denis Diderot, Université
electromagnetic pulse at a central frequency of 2.45 GHz in a high-Q cavity. Another antenna records the stronglyRadio Science, Volume ???, Number , Pages 110, Time Reversal of Electromagnetic Waves demonstration of time-reversal focusing with electromagnetic waves in a SISO scheme. An antenna transmits a 1 µs
Woodruff, Dana L.; Cullinan, Valerie I.; Copping, Andrea E.; Marshall, Kathryn E.
2013-05-20T23:59:59.000Z
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).
INVERSE SCATTERING PROBLEMS WITH MULTI-FREQUENCIES ...
2015-01-25T23:59:59.000Z
Numerical experiments are included to illustrate the ...... electromagnetic field on the surface of the human brain to infer the abnormalities inside the brain [53].
Electromagnetic and spin polarisabilities in lattice QCD
W. Detmold; B. C. Tiburzi; A. Walker-Loud
2006-10-02T23:59:59.000Z
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.
Quantum modulation against electromagnetic interference
Juan Carlos Garcia-Escartin
2014-11-26T23:59:59.000Z
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.
Perpendicular propagating electromagnetic envelope solitons in electron-positron-ion plasma
Jehan, Nusrat [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Salahuddin, M. [Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan)
2010-05-15T23:59:59.000Z
The nonlinear amplitude modulation of electromagnetic waves propagating perpendicular to the direction of ambient magnetic field in a uniform collisionless magnetized electron-positron-ion plasma is studied. The Krylov-Bogoliubov-Mitropolsky perturbation method is employed to derive nonlinear Schroedinger equation, which describes the amplitude dynamics of perturbed magnetic field. The modulation instability criterion reveals that the low frequency mode is always stable, whereas the high frequency mode becomes modulationally unstable for certain ranges of wave number and positron-to-electron density ratio. Furthermore, the positron-to-electron density ratio as well as the strength of ambient magnetic field is found to have significant effect on the solitary wave solutions of the nonlinear Schroedinger equation, namely, dark and bright envelope solitons.
Electromagnetic properties of massive neutrinos
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
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.
The nature of electromagnetic energy
Jerrold Franklin
2012-05-29T23:59:59.000Z
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
A. L. Barabanov; R. Golub; S. K. Lamoreaux
2005-12-20T23:59:59.000Z
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.
Steyerl, A; Müller, G; Golub, R
2015-01-01T23:59:59.000Z
The important role of geometric phases in searches for a permanent electric dipole moment of the neutron, using Ramsey separated oscillatory field nuclear magnetic resonance, was first investigated by Pendlebury $\\textit{et al.}$ [Phys. Rev. A $\\mathbf{70}$, 032102 (2004)]. Their analysis was based on the Bloch equations. In subsequent work using the spin density matrix Lamoreaux and Golub [Phys. Rev. A $\\mathbf{71}$, 032104 (2005)] showed the usual relation between the frequency shifts and the correlation functions of the fields seen by trapped particles in general fields (Redfield theory). More recently we presented a solution of the Schr\\"odinger equation for spin-$1/2$ particles in circular cylindrical traps with smooth walls and exposed to arbitrary fields [Steyerl $\\textit{et al.}$, Phys.Rev. A $\\mathbf{89}$, 052129 (2014)]. Here we extend this work to show how the Redfield theory follows directly from the Schr\\"odinger equation solution and include wall roughness, cylindrical trap geometry with arbitra...
The classical geometrization of the electromagnetism
Celso de Araujo Duarte
2015-08-13T23:59:59.000Z
Following the line of the history, if by one side the electromagnetic theory was consolidated on the 19th century, the emergence of the special and the general relativity theories on the 20th century opened possibilities of further developments, with the search for the unification of the gravitation and the electromagnetism on a single unified theory. Some attempts to the geometrization of the electromagnetism emerged in this context, where these first models resided strictly on a classical basis. Posteriorly, they were followed by more complete and embracing quantum field theories. The present work reconsiders the classical viewpoint, with the purpose of showing that at first order of approximation the electromagnetism constitutes a geometric structure aside other phenomena as gravitation, and that magnetic monopoles do not exist at least up to this order of approximation. Even though being limited, the model is consistent and offers the possibility of an experimental test of validity.
Spin polarized electron-positron pair production via elliptical polarized laser fields
Anton Wöllert; Heiko Bauke; Christoph H. Keitel
2015-02-23T23:59:59.000Z
We study nonperturbative multiphoton electron-positron pair creation in ultra-strong electromagnetic fields formed by two counterpropagating pulses with elliptic polarization. Our numerical approach allows us to take into account the temporal as well as the spatial variation of the standing electromagnetic field. The spin and momentum resolved pair creation probabilities feature characteristic Rabi oscillations and resonance spectra. Therefore, each laser frequency features a specific momentum distribution of the created particles. We find that depending on the relative polarization of both pulses the created electrons may be spin polarized along the direction of field propagation.
Spin polarized electron-positron pair production via elliptical polarized laser fields
Wöllert, Anton; Keitel, Christoph H
2015-01-01T23:59:59.000Z
We study nonperturbative multiphoton electron-positron pair creation in ultra-strong electromagnetic fields formed by two counterpropagating pulses with elliptic polarization. Our numerical approach allows us to take into account the temporal as well as the spatial variation of the standing electromagnetic field. The spin and momentum resolved pair creation probabilities feature characteristic Rabi oscillations and resonance spectra. Therefore, each laser frequency features a specific momentum distribution of the created particles. We find that depending on the relative polarization of both pulses the created electrons may be spin polarized along the direction of field propagation.
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
Tunability enhanced electromagnetic wiggler
Schlueter, Ross D. (Albany, CA); Deis, Gary A. (Livermore, CA)
1992-01-01T23:59:59.000Z
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.
A universal electromagnetic energy conversion adapter based on a metamaterial absorber
Xie, Yunsong; Wilson, Jeffrey D; Simons, Rainee N; Chen, Yunpeng; Xiao, John Q
2013-01-01T23:59:59.000Z
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.
Resonance of relativistic electrons with electromagnetic ion cyclotron waves
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Denton, R. E.; Jordanova, V. K.; Bortnik, J.
2015-06-29T23:59:59.000Z
Relativistic electrons have been thought to more easily resonate with electromagnetic ion cyclotron EMIC waves if the total density is large. We show that, for a particular EMIC mode, this dependence is weak due to the dependence of the wave frequency and wave vector on the density. A significant increase in relativistic electron minimum resonant energy might occur for the H band EMIC mode only for small density, but no changes in parameters significantly decrease the minimum resonant energy from a nominal value. The minimum resonant energy depends most strongly on the thermal velocity associated with the field line motionmore »of the hot ring current protons that drive the instability. High density due to a plasmasphere or plasmaspheric plume could possibly lead to lower minimum resonance energy by causing the He band EMIC mode to be dominant. We demonstrate these points using parameters from a ring current simulation.« less
Superconductors as quantum transducers and antennas for gravitational and electromagnetic radiation
Raymond Y. Chiao
2002-07-29T23:59:59.000Z
Superconductors will be considered as macroscopic quantum gravitational antennas and transducers, which can directly convert upon reflection a beam of quadrupolar electromagnetic radiation into gravitational radiation, and vice versa, and thus serve as practical laboratory sources and receivers of microwave and other radio-frequency gravitational waves. An estimate of the transducer conversion efficiency on the order of unity comes out of the Ginzburg-Landau theory for an extreme type II, dissipationless superconductor with minimal coupling to weak gravitational and electromagnetic radiation fields, whose frequency is smaller than the BCS gap frequency, thus satisfying the quantum adiabatic theorem. The concept of ``the impedance of free space for gravitational plane waves'' is introduced, and leads to a natural impedance-matching process, in which the two kinds of radiation fields are impedance-matched to each other around a hundred coherence lengths beneath the surface of the superconductor. A simple, Hertz-like experiment has been performed to test these ideas, and preliminary results will be reported. (PACS nos.: 03.65.Ud, 04.30.Db, 04.30.Nk, 04.80.Nn, 74.60-w, 74.72.Bk)
Mitigation of Electromagnetic Pulse (EMP) Effects from Short-Pulse Lasers and Fusion Neutrons
Eder, D C; Throop, A; Brown, Jr., C G; Kimbrough, J; Stowell, M L; White, D A; Song, P; Back, N; MacPhee, A; Chen, H; DeHope, W; Ping, Y; Maddox, B; Lister, J; Pratt, G; Ma, T; Tsui, Y; Perkins, M; O'Brien, D; Patel, P
2009-03-06T23:59:59.000Z
Our research focused on obtaining a fundamental understanding of the source and properties of EMP at the Titan PW(petawatt)-class laser facility. The project was motivated by data loss and damage to components due to EMP, which can limit diagnostic techniques that can be used reliably at short-pulse PW-class laser facilities. Our measurements of the electromagnetic fields, using a variety of probes, provide information on the strength, time duration, and frequency dependence of the EMP. We measure electric field strengths in the 100's of kV/m range, durations up to 100 ns, and very broad frequency response extending out to 5 GHz and possibly beyond. This information is being used to design shielding to mitigate the effects of EMP on components at various laser facilities. We showed the need for well-shielded cables and oscilloscopes to obtain high quality data. Significant work was invested in data analysis techniques to process this data. This work is now being transferred to data analysis procedures for the EMP diagnostics being fielded on the National Ignition Facility (NIF). In addition to electromagnetic field measurements, we measured the spatial and energy distribution of electrons escaping from targets. This information is used as input into the 3D electromagnetic code, EMSolve, which calculates time dependent electromagnetic fields. The simulation results compare reasonably well with data for both the strength and broad frequency bandwidth of the EMP. This modeling work required significant improvements in EMSolve to model the fields in the Titan chamber generated by electrons escaping the target. During dedicated Titan shots, we studied the effects of varying laser energy, target size, and pulse duration on EMP properties. We also studied the effect of surrounding the target with a thick conducting sphere and cube as a potential mitigation approach. System generated EMP (SGEMP) in coaxial cables does not appear to be a significant at Titan. Our results are directly relevant to planned short-pulse ARC (advanced radiographic capability) operation on NIF.
Line geometry and electromagnetism III: groups of transformations
D. H. Delphenich
2014-04-16T23:59:59.000Z
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.
Particle Acceleration by a Short-Intense Elliptically Polarized Electromagnetic
Paris-Sud XI, Université de
Particle Acceleration by a Short-Intense Elliptically Polarized Electromagnetic Pulse Propagating to plasma physics and particle accelerators. The interaction physics of fields with particles has also been, Colchester CO4 3SQ, U.K. Abstract. The motion of a charged particle driven by an electromagnetic pulse
Zhang, Xi-Cheng; Riordan, Jenifer Ann; Sun, Feng-Guo
2000-08-29T23:59:59.000Z
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.
Spherically symmetric electromagnetic mass models of embedding class one
S. K. Maurya; Y. K. Gupta; Saibal Ray; Sourav Roy Chowdhury
2015-05-30T23:59:59.000Z
In this article we consider the static spherically symmetric spacetime metric of embedding class one. Specifically three new electromagnetic mass models are derived where the solutions are entirely dependent on the electromagnetic field, such that the physical parameters, like density, pressure etc. do vanish for the vanishing charge. We have analyzed schematically all these three sets of solutions related to electromagnetic mass models by plotting graphs and shown that they can pass through all the physical tests performed by us. To validate these special type of solutions related to electromagnetic mass models a comparison has been done with that of compact stars and shown exclusively the feasibility of the models.
Boxer, Steven G.
-9817). This correlation can be quantitatively explained if the dispersion in jNO and jCO is modeled as an electrochromic, electrochromic band shifts due to the interaction between µ associated with the oscillator and the electric field
Compression of Laser Radiation in Plasmas Using Electromagnetic Cascading
Kalmykov, Serguei; Shvets, Gennady [Department of Physics and Institute for Fusion Studies, University of Texas at Austin, One University Station C1500, Austin, Texas 78712 (United States)
2005-06-17T23:59:59.000Z
Compressing high-power laser beams in plasmas via generation of a coherent cascade of electromagnetic sidebands is described. The technique requires two copropagating beams detuned by a near-resonant frequency {omega} < or approx. {omega}{sub p}. The ponderomotive force of the laser beat wave drives an electron plasma wave which modifies the refractive index of plasma so as to produce a periodic phase modulation of the laser field with the beat period {tau}{sub b}=2{pi}/{omega}. A train of chirped laser beat notes (each of duration {tau}{sub b}) is thus created. The group velocity dispersion of radiation in plasma can then compress each beat note to a few-laser-cycle duration. As a result, a train of sharp electromagnetic spikes separated in time by {tau}{sub b} is formed. Depending on the plasma and laser parameters, chirping and compression can be implemented either concurrently in the same plasma or sequentially in different plasmas.
Electromagnetic Effects in SDF Explosions
Reichenbach, H; Neuwald, P; Kuhl, A L
2010-02-12T23:59:59.000Z
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.
Purely electromagnetic spacetimes
B. V. Ivanov
2007-12-15T23:59:59.000Z
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.
S. K. Lamoreaux; R. Golub
2005-01-25T23:59:59.000Z
The search for particle electric dipole moments (edm) is one of the best places to look for physics beyond the standard model because the size of time reversal violation predicted by the standard model is incompatible with present ideas concerning the creation of the Baryon-Antibaryon asymmetry. As the sensitivity of these edm searches increases more subtle systematic effects become important. We develop a general analytical approach to describe a systematic effect recently observed in an electric dipole moment experiment using stored particles \\cite{JMP}. Our approach is based on the relationship between the systematic frequency shift and the velocity autocorrelation function of the resonating particles. Our results, when applied to well-known limiting forms of the correlation function, are in good agreement with both the limiting cases studied in recent work that employed a numerical/heuristic analysis. Our general approach explains some of the surprising results observed in that work and displays the rich behavior of the shift for intermediate frequencies, which has not been previously studied.
Gradient instabilities of electromagnetic waves in Hall thruster plasma
Tomilin, Dmitry [Department of Electrophysics, Keldysh Research Centre, Moscow 125438 (Russian Federation)
2013-04-15T23:59:59.000Z
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.
A. Steyerl; C. Kaufman; G. Müller; R. Golub
2015-05-13T23:59:59.000Z
The important role of geometric phases in searches for a permanent electric dipole moment of the neutron, using Ramsey separated oscillatory field nuclear magnetic resonance, was first investigated by Pendlebury $\\textit{et al.}$ [Phys. Rev. A $\\mathbf{70}$, 032102 (2004)]. Their analysis was based on the Bloch equations. In subsequent work using the spin density matrix Lamoreaux and Golub [Phys. Rev. A $\\mathbf{71}$, 032104 (2005)] showed the usual relation between the frequency shifts and the correlation functions of the fields seen by trapped particles in general fields (Redfield theory). More recently we presented a solution of the Schr\\"odinger equation for spin-$1/2$ particles in circular cylindrical traps with smooth walls and exposed to arbitrary fields [Steyerl $\\textit{et al.}$, Phys.Rev. A $\\mathbf{89}$, 052129 (2014)]. Here we extend this work to show how the Redfield theory follows directly from the Schr\\"odinger equation solution and include wall roughness, cylindrical trap geometry with arbitrary cross section, and field perturbations that do not, in the frame of the moving particles, average to zero in time and which, therefore, do not satisfy the prerequisites of the statistical approach based on the spin-density matrix. We show by direct, detailed, calculation the agreement of the results from the Schr\\"odinger equation with the Redfield theory for the cases of a rectangular cell with specular walls and of a circular cell with diffuse reflecting walls.
Slave Electromagnetic studies Alan G. Jones1
Jones, Alan G.
and Jessica Spratt1,5 1 Geological Survey of Canada, 615 Booth St., Ottawa, Ontario, K1A 0E9, Canada. Email-probing electromagnetic surveys, using the nautral-source magnetotelluric (MT) technique, have recently been carried out. The former ensured low resistance ground contact for electric field measurements, and the latter avoided
Nonlinear Landau damping of transverse electromagnetic waves in dusty plasmas
Tsintsadze, N. L. [E. Andronikashvili Institute of Physics, Tbilisi 0171 (Georgia); Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Chaudhary, Rozina [Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Shah, H. A. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Murtaza, G. [Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan)
2009-04-15T23:59:59.000Z
High-frequency transverse electromagnetic waves in a collisionless isotropic dusty plasma damp via nonlinear Landau damping. Taking into account the latter we have obtained a generalized set of Zakharov equations with local and nonlocal terms. Then from this coupled set of Zakharov equations a kinetic nonlinear Schroedinger equation with local and nonlocal nonlinearities is derived for special cases. It is shown that the modulation of the amplitude of the electromagnetic waves leads to the modulation instability through the nonlinear Landau damping term. The maximum growth rate is obtained for the special case when the group velocity of electromagnetic waves is close to the dust acoustic velocity.
Duality in Off-Shell Electromagnetism
Martin Land
2006-03-21T23:59:59.000Z
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.
Scanning evanescent electro-magnetic microscope
Xiang, Xiao-Dong (Alameda, CA); Gao, Chen (Anhui, CN); Schultz, Peter G. (La Jolla, CA); Wei, Tao (Sunnyvale, CA)
2003-01-01T23:59:59.000Z
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.
Scanning evanescent electro-magnetic microscope
Xiang, Xiao-Dong (Alameda, CA); Gao, Chen (Alameda, CA)
2001-01-01T23:59:59.000Z
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.
Bioelectromagnetic effects of the electromagnetic pulse (EMP)
Patrick, E.L.; Vault, W.L.
1990-03-01T23:59:59.000Z
The public has expressed concern about the biological effects and hazards of non-ionizing electromagnetic fields produced by the electro-magnetic pulse (EMP) simulators that simulate the EMP emanating from a high-altitude nuclear explosion. This paper provides a summary of the bioelectromagnetic effects literature up through the present, describes current occupational standards for workers exposed to the EMP environment, and discusses the use of medical surveillance as it relates to the potential human health hazards associated with exposure to the EMP environment.
Woodruff, Dana L.; Schultz, Irvin R.; Marshall, Kathryn E.; Ward, Jeffrey A.; Cullinan, Valerie I.
2012-05-01T23:59:59.000Z
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.
Electromagnetic SCRF Cavity Tuner
Kashikhin, V.; Borissov, E.; Foster, G.W.; Makulski, A.; Pischalnikov, Y.; Khabiboulline, T.; /Fermilab
2009-05-01T23:59:59.000Z
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.
Electromagnetic Radiations as a Fluid Flow
Daniele Funaro
2009-11-25T23:59:59.000Z
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.
Jin Li; Kai Lin; Nan Yang
2015-03-24T23:59:59.000Z
Based on a regular exact black hole (BH) from nonlinear electrodynamics (NED) coupled to General Relativity, we investigate its stability of such BH through the Quasinormal Modes (QNMs) of electromagnetic (EM) field perturbation and its thermodynamics through Hawking radiation. In perturbation theory, we can deduce the effective potential from nonlinear EM field. The comparison of potential function between regular and RN BHs could predict their similar QNMs. The QNMs frequencies tell us the effect of magnetic charge $q$, overtone $n$, angular momentum number $l$ on the dynamic evolution of NLED EM field. Furthermore we also discuss the cases near extreme condition of such magnetically charged regular BH. The corresponding QNMs spectrum illuminates some special properties in the near-extreme cases. For the thermodynamics, we employ Hamilton-Jacobi method to calculate the near-horizon Hawking temperature of the regular BH and reveal the relationship between classical parameters of black hole and its quantum effect.
Jin, Yao; Hu, Jiawei [Institute of Physics and Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, Hunan 410081 (China); Yu, Hongwei, E-mail: hwyu@hunnu.edu.cn [Institute of Physics and Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, Hunan 410081 (China); Center for Nonlinear Science and Department of Physics, Ningbo University, Ningbo, Zhejiang 315211 (China)
2014-05-15T23:59:59.000Z
We study, using the formalism proposed by Dalibard, Dupont-Roc and Cohen-Tannoudji, the contributions of the vacuum fluctuation and radiation reaction to the rate of change of the mean atomic energy for a circularly accelerated multilevel atom coupled to vacuum electromagnetic fields in the ultrarelativistic limit. We find that the balance between vacuum fluctuation and radiation reaction is broken, which causes spontaneous excitations of accelerated ground state atoms in vacuum. Unlike for a circularly accelerated atom coupled to vacuum scalar fields, the contribution of radiation reaction is also affected by acceleration, and this term takes the same form as that of a linearly accelerated atom coupled to vacuum electromagnetic fields. For the contribution of vacuum fluctuations, we find that in contrast to the linear acceleration case, terms proportional to the Planckian factor are replaced by those proportional to a non-Planck exponential term, and this indicates that the radiation perceived by a circularly orbiting observer is no longer thermal as is in the linear acceleration case. However, for an ensemble of two-level atoms, an effective temperature can be defined in terms of the atomic transition rates, which is found to be dependent on the transition frequency of the atom. Specifically, we calculate the effective temperature as a function of the transition frequency and find that in contrast to the case of circularly accelerated atoms coupled to the scalar field, the effective temperature in the current case is always larger than the Unruh temperature. -- Highlights: •We study the spontaneous excitation of a circularly accelerated atom. •Contribution of radiation reaction to the excitation is affected by acceleration. •The radiation perceived by a circularly orbiting observer is no longer thermal. •An effective temperature can be defined in terms of atomic transition rates. •Effective temperature is larger than Unruh temperature and frequency-dependent.
On the Derivative Expansion for the Electromagnetic Casimir Free Energy at High Temperatures
Fosco, C D; Mazzitelli, F D
2015-01-01T23:59:59.000Z
We study the contribution of the thermal zero modes to the Casimir free energy, in the case of a fluctuating electromagnetic (EM) field in the presence of real materials described by frequency-dependent, local and isotropic permittivity ($\\epsilon$) and permeability ($\\mu$) functions. Those zero modes, present at any finite temperature, become dominant at high temperatures, since the theory is dimensionally reduced. Our work, within the context of the Derivative Expansion (DE) approach, focusses on the emergence of non analyticities in that dimensionally reduced theory. We conclude that the DE is well defined whenever the function $\\Omega(\\omega)$, defined by $[\\Omega(\\omega)]^2 \\equiv \\omega^2\\epsilon(\\omega)$, vanishes in the zero-frequency limit, for at least one of the two material media involved.
Fluidic electrodynamics: Approach to electromagnetic propulsion
Martins, Alexandre A.; Pinheiro, Mario J. [Institute for Plasmas and Nuclear Fusion and Instituto Superior Tecnico Lisboa, Portugal 351.1.21.841.92.43 (Portugal); Department of Physics and Institute for Plasmas and Nuclear Fusion and Instituto Superior Tecnico Lisboa, Portugal 351.1.21.841.93.22 (Portugal)
2009-03-16T23:59:59.000Z
We report on a new methodological approach to electrodynamics based on a fluidic viewpoint. We develop a systematic approach establishing analogies between physical magnitudes and isomorphism (structure-preserving mappings) between systems of equations. This methodological approach allows us to give a general expression for the hydromotive force, thus re-obtaining the Navier-Stokes equation departing from the appropriate electromotive force. From this ground we offer a fluidic approach to different kinds of issues with interest in propulsion, e.g., the force exerted by a charged particle on a body carrying current; the magnetic force between two parallel currents; the Magnus's force. It is shown how the intermingle between the fluid vector fields and electromagnetic fields leads to new insights on their dynamics. The new concepts introduced in this work suggest possible applications to electromagnetic (EM) propulsion devices and the mastery of the principles of producing electric fields of required configuration in plasma medium.
Quasinormal modes of test fields around regular black holes
Bobir Toshmatov; Ahmadjon Abdujabbarov; Zden?k Stuchlík; Bobomurat Ahmedov
2015-04-25T23:59:59.000Z
We study scalar, electromagnetic and gravitational test fields in the Hayward, Bardeen and Ay\\'on-Beato-Garc\\'ia 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.
Chen Ziyu; Li Jianfeng; Yu Yong; Li Xiaoya; Peng Qixian; Zhu Wenjun [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Wang Jiaxiang [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China)
2012-11-15T23:59:59.000Z
The influences of lateral target size on hot electron production and electromagnetic pulse emission from laser interaction with metallic targets have been investigated. Particle-in-cell simulations at high laser intensities show that the yield of hot electrons tends to increase with lateral target size, because the larger surface area reduces the electrostatic field on the target, owing to its expansion along the target surface. At lower laser intensities and longer time scales, experimental data characterizing electromagnetic pulse emission as a function of lateral target size also show target-size effects. Charge separation and a larger target tending to have a lower target potential have both been observed. The increase in radiation strength and downshift in radiation frequency with increasing lateral target size can be interpreted using a simple model of the electrical capacity of the target.
A generalized Debye source approach to electromagnetic scattering in layered media
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
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.
Electromagnetic Radiation REFERENCE: Remote Sensing of
Gilbes, Fernando
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
Electromagnetically Induced Flows Michiel de Reus
Vuik, Kees
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
8.07 Electromagnetism II, Fall 2005
Bertschinger, Edmund
This course is the second in a series on Electromagnetism beginning with Electromagnetism I (8.02 or 8.022). It is a survey of basic electromagnetic phenomena: electrostatics; magnetostatics; electromagnetic properties of ...
Electromagnetic Mass Models in General Theory of Relativity
Sumana Bhadra
2007-10-30T23:59:59.000Z
"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".
Graphene Frequency Multipliers
Wang, Han
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 ...
Electromagnetism and Gravitation
Kenneth Dalton
1997-03-10T23:59:59.000Z
The classical concept of "mass density" is not fundamental to the quantum theory of matter. Therefore, mass density cannot be the source of gravitation. Here, we treat electromagnetic energy, momentum, and stress as its source. The resulting theory predicts that the gravitational potential near any charged elementary particle is many orders of magnitude greater than the Newtonian value.
Electromagnetic pulsar spindown
I. Contopoulos
2007-01-10T23:59:59.000Z
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.
Electromagnetic Interrogation Techniques Damage Detection
Electromagnetic Interrogation Techniques for Damage Detection H. T. Banks #3; and M. L. Joyner Wincheski and W.P. Winfree Nasa Langley Research Center Hampton, VA #3; Plenary Lecture, Electromagnetic Nondestructive Evaluation 2001 (ENDE 2001), Kobe, Japan, May 1819, 20001 #12; Electromagnetic Interrogation
Electromagnetic Interrogation Techniques Damage Detection
Electromagnetic Interrogation Techniques for Damage Detection H. T. Banks and M. L. Joyner Center.P. Winfree Nasa Langley Research Center Hampton, VA Plenary Lecture, Electromagnetic Nondestructive Evaluation 2001 (ENDE 2001), Kobe, Japan, May 18-19, 20001 #12;Electromagnetic Interrogation Techniques
Variable frequency photonic crystals
Wu, Xiang-Yao; Liu, Xiao-Jing; Yang, Jing-Hai; Li, Hong; Chen, Wan-Jin
2015-01-01T23:59:59.000Z
In this paper, we have firstly proposed a new one-dimensional variable frequency photonic crystals (VFPCs), and calculated the transmissivity and the electronic field distribution of VFPCs with and without defect layer, and considered the effect of defect layer and variable frequency function on the transmissivity and the electronic field distribution. We have obtained some new characteristics for the VFPCs, which should be help to design a new type optical devices.
Youn, Sangseok
2014-08-07T23:59:59.000Z
better understanding of anisotropic Earth responses using the MCSEM method is the main objective of this thesis. The controlled-source electromagnetic response in the frequency domain due to excitation by a horizontal electric dipole (HED) transmitter...
Youn, Sangseok
2014-08-07T23:59:59.000Z
better understanding of anisotropic Earth responses using the MCSEM method is the main objective of this thesis. The controlled-source electromagnetic response in the frequency domain due to excitation by a horizontal electric dipole (HED) transmitter...
Electromagnetic Properties of the Early Universe
Keitaro Takahashi; Kiyotomo Ichiki; Naoshi Sugiyama
2008-05-29T23:59:59.000Z
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.
Quantum field theoretical description for the reflectivity of graphene
Bordag, M; Mostepanenko, V M; Petrov, V M
2015-01-01T23:59:59.000Z
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.
An approach to electromagnetism from the general relativity
Robert Monjo i Agut
2013-12-02T23:59:59.000Z
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.
Theory of electromagnetic fluctuations for magnetized multi-species plasmas
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
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.
Electromagnetic time reversal algorithms and source localization in lossy dielectric media
Abdul Wahab; Amer Rasheed; Tasawar Hayat; Rab Nawaz
2014-09-16T23:59:59.000Z
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.
Analysis of electromagnetic scattering by nearly periodic structures: an LDRD report.
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
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.
Gravitation and Electromagnetism
B. G. Sidharth
2001-06-16T23:59:59.000Z
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.
Fractional Electromagnetic Waves
J. F. Gómez; J. J. Rosales; J. J. Bernal; V. I. Tkach; M. Guía
2011-08-31T23:59:59.000Z
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.
Banded electromagnetic stator core
Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.
1994-04-05T23:59:59.000Z
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.
Electromagnetic Siegert states for periodic dielectric structures
Friends R. Ndangali; Sergei V. Shabanov
2011-08-09T23:59:59.000Z
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.
Kohno, Haruhiko
2011-01-01T23:59:59.000Z
Electromagnetic plasma waves in the ion cyclotron range of frequencies (ICRF) are routinely used in magnetic fusion experiments to heat plasmas and drive currents. However, many experiments have revealed that wave energy ...
Manipulation of Electromagnetic Fields with Plasmonic Nanostructures...
Office of Scientific and Technical Information (OSTI)
Subject: Materials Science(36); Nanoscience & Nanotechnology(77) Material Science Word Cloud More Like This Full Text File size NAView Full Text View Full Text DOI: 10.2172...
The sensitivity of children to electromagnetic fields
Kheifets, Leeka; Repacholi, M; Saunders, R; van Deventer, E
2005-01-01T23:59:59.000Z
International Commission on Non-ionizing Radiation Protection.International Commission on Non-Ionizing Radiation Protection.
Florida, University of
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY, VOL. 47, NO. 3, AUGUST 2005 521 Abstract--It is known from both theory and numerical simula- tions that a current pulse suffers apparent electromagnetic field structure is non-transverse electromagnetic (TEM), particu- larly near the source region
Geometrical Interpretation of Electromagnetism in 5-Dimensional Manifold
TaeHun Kim; Hyunbyuk Kim
2015-07-12T23:59:59.000Z
In this paper Kaluza-Klein theory is revisited and its implications are elaborated. We show that electromagnetic 4-potential is a deformation factor of a 5-dimensional (5D) manifold along the fifth (5th) axis. The charge-to-mass ratio has a physical meaning as the ratio of the movement along the direction of the 5th axis to the movement in the 4D space-time. Examinations on the interaction between particles registered by different observers suggest a covariance breaking of the 5th dimension. In order to have a 5D matter which is consistent with the construction of the 5D manifold, a notion of particle-thread is considered. Finally, the field equations which extend the Einstein field equations give the total energy-momentum tensor as a sum of that of matter, electromagnetic field, and the interaction between electric current and electromagnetic field.
Geometrical Interpretation of Electromagnetism in 5-Dimensional Manifold
Kim, TaeHun
2015-01-01T23:59:59.000Z
In this paper Kaluza-Klein theory is revisited and its implications are elaborated. We show that electromagnetic 4-potential is a deformation factor of a 5-dimensional (5D) manifold along the fifth (5th) axis. The charge-to-mass ratio has a physical meaning as the ratio of the movement along the direction of the 5th axis to the movement in the 4D space-time. Examinations on the interaction between particles registered by different observers suggest a covariance breaking of the 5th dimension. In order to have a 5D matter which is consistent with the construction of the 5D manifold, a notion of particle-thread is considered. Finally, the field equations which extend the Einstein field equations give the total energy-momentum tensor as a sum of that of matter, electromagnetic field, and the interaction between electric current and electromagnetic field.
Electromagnetic Compatibility in Nuclear Power Plants
Ewing, P.D.; Kercel, S.W.; Korsah, K.; Wood, R.T.
1999-08-29T23:59:59.000Z
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.
Classification of Electromagnetic and Gravitational Hopfions by Algebraic Type
Amy Thompson; Alexander Wickes; Joe Swearngin; Dirk Bouwmeester
2015-05-02T23:59:59.000Z
We extend the definition of hopfions to include a class of spin-$h$ fields and use this to introduce the electromagnetic and gravitational hopfions of different algebraic types. The fields are constructed through the Penrose contour integral transform, thus the singularities of the generating functions are directly related to the geometry of the resulting physical fields. We discuss this relationship and how the topological structure of the fields is related to the Robinson congruence. Since the topology appears in the lines of force for both electromagnetism and gravity, the gravito-electromagnetic formalism is used to analyze the gravitational hopfions and describe the time evolution of their tendex and vortex lines. The correspondence between fields of different spin results in analogous configurations based on the same topological structure. The null and type N fields propagate at the speed of light, while the non-null and type D fields radiate energy outward from the center. Finally we discuss the type III gravitational hopfion, which has no direct electromagnetic analog, but find that it still exhibits some of the characteristic features common to the other hopfion fields.
A characterization of the electromagnetic stress-energy tensor
J. Navarro; J. B. Sancho
2011-01-13T23:59:59.000Z
In a previous paper, we pointed out how a dimensional analysis of the stress-energy tensor of the gravitational field allows to derive the field equation of General Relativity. In this note, we comment an analogous reasoning in presence of a 2-form, that allows to characterize the so called electromagnetic stress-energy tensor.
General Polarization Matrix of Electromagnetic Radiation
Muhammet Ali Can; Alexander S. Shumovsky
2001-05-15T23:59:59.000Z
A general form of the polarization matrix valid for any type of electromagnetic radiation (plane waves, multipole radiation etc.) is defined in terms of a certain bilinear form in the field-strength tensor. The quantum counterpart is determined as an operator matrix with normal-ordered elements with respect to the creation and annihilation operators. The zero-point oscillations (ZPO) of polarization are defined via difference between the anti-normal and normal ordered operator polarization matrices. It is shown that ZPO of the multipole field are stronger than those described by the model of plane waves and are concentrated in a certain neighborhood of a local source.
Vibration Harvesting using Electromagnetic Transduction
Waterbury, Andrew
2011-01-01T23:59:59.000Z
Puers, “Harvesting Energy from Vibrations by a Micromachinedsignal processing using vibration-based power generation,”electromagnetic generator for vibration energy harvesting,”
Electromagnetic Probes in PHENIX
Gabor David
2006-09-21T23:59:59.000Z
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.
Electromagnetic pump stator coil
Fanning, Alan W. (San Jose, CA); Dahl, Leslie R. (Livermore, CA)
1996-01-01T23:59:59.000Z
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.
Electromagnetic pump stator coil
Fanning, A.W.; Dahl, L.R.
1996-06-25T23:59:59.000Z
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.
Low-frequency resonances of the refractive index in weakly ionized plasma with an admixture of dust
Prudskikh, V. V., E-mail: slavadhb@mail.ru [Southern Federal University, Faculty of Physics (Russian Federation)
2013-12-15T23:59:59.000Z
The propagation of low-frequency electromagnetic waves along the magnetic field in weakly ionized plasma with an admixture of dust is studied in the framework of the Hall magnetohydrodynamics. Explicit expressions for the coefficients of magnetic field diffusion in plasma are derived. The resonance of the refractive index is found to occur for either right- or left-hand polarized waves. A quantitative criterion is obtained that allows one to determine the polarization of waves that experience resonance at given plasma parameters. The physical mechanism of the resonance is discussed, and the obtained results are compared with the available literature data.
Microfabricated ion frequency standard
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
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.
Spacetime dynamics of spinning particles - exact gravito-electromagnetic analogies
L. Filipe O. Costa; José Natário; Miguel Zilhão
2015-07-29T23:59:59.000Z
We compare the rigorous equations describing the motion of spinning test particles in gravitational and electromagnetic fields, and show that if the Mathisson-Pirani spin condition holds then exact gravito-electromagnetic analogies emerge. These analogies provide a familiar formalism to treat gravitational problems, as well as a means for comparing the two interactions. Fundamental differences are manifest in the symmetries and time projections of the electromagnetic and gravitational tidal tensors. The physical consequences of the symmetries of the tidal tensors are explored comparing the following analogous setups: magnetic dipoles in the field of non-spinning/spinning charges, and gyroscopes in the Schwarzschild, Kerr, and Kerr-de Sitter spacetimes. The implications of the time-projections of the tidal tensors are illustrated by the work done on the particle in various frames; in particular, a reciprocity is found to exist: in a frame comoving with the particle, the electromagnetic (but not the gravitational) field does work on it, causing a variation of its proper mass; conversely, for "static observers", a stationary gravitomagnetic (but not a magnetic) field does work on the particle, and the associated potential energy is seen to embody the Hawking-Wald spin-spin interaction energy. The issue of hidden momentum, and its counterintuitive dynamical implications, is also analyzed. Finally, a number of issues regarding the electromagnetic interaction are clarified, namely the differences in the dynamics of electric and magnetic dipoles, and the physical meaning of Dixon's equations.
Borisov, A. V.; Kerimov, B. K.; Sizin, P. E., E-mail: borisov@phys.msu.ru [Moscow State University (Russian Federation)
2012-11-15T23:59:59.000Z
Expressions for the power of neutrino radiation from a degenerate electron gas in a strong magnetic field are derived for the case of neutrino-pair photoproduction via the weak and electromagnetic interaction mechanisms (it is assumed that the neutrino possesses electromagnetic form factors). It is shown that the neutrino luminosity of a medium in the electromagnetic reaction channel may exceed substantially the luminosity in the weak channel. Relative upper bounds on the effective neutrino magnetic moment are obtained.
Frequency-Domain Electromagnetic Survey | Open Energy Information
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 DeliciousPlasmaP aCentrothermDepew, New York:EssexInstitute for Solar Energy SystemsFremont County,French
Frequency-Domain Electromagnetic Survey | Open Energy Information
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 DeliciousPlasmaP aCentrothermDepew, New York:EssexInstitute for Solar Energy SystemsFremont
Frequency-Domain Electromagnetics Survey At Kilauea East Rift Geothermal
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 DeliciousPlasmaP aCentrothermDepew, New York:EssexInstitute for Solar Energy SystemsFremontArea (FURUMOTO, 1976) | Open
Controlled Source Frequency-Domain Electromagnetics At Neal Hot Springs
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 DeliciousPlasmaP a g eWorksVillagesource History View New Pages Recent Changes AllContinuous
Controlled Source Frequency-Domain Electromagnetics At Neal Hot Springs
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 DeliciousPlasmaP a g eWorksVillagesource History View New Pages Recent Changes AllContinuousGeothermal Area (Shaltry,
Controlled Source Frequency-Domain Electromagnetics At Neal Hot...
Colorado School of Mines and Imperial College London (2011) Geophysical Characterization of a Geothermal System Neal Hot Springs, Oregon, USA Additional References...
Controlled Source Frequency-Domain Electromagnetics At Neal Hot...
2012 Colorado School of Mines and Imperial College London (2011) Geophysical Characterization of a Geothermal System Neal Hot Springs, Oregon, USA Additional References...
Electromagnetic neutrino: a short review
Alexander I. Studenikin
2014-11-09T23:59:59.000Z
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.
A fast multigrid-based electromagnetic eigensolver for curved metal boundaries on the Yee mesh
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
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.
Electromagnetic triangle anomaly and neutral pion condensation in QCD vacuum
Cao, Gaoqing
2015-01-01T23:59:59.000Z
We study the QCD vacuum structure under the influence of an electromagnetic field with a nonzero second Lorentz invariant $I_2=\\vec{E}\\cdot{\\vec B}$. We show that the presence of $I_2$ can induce neutral pion ($\\pi^0$) condensation in the QCD vacuum through the electromagnetic triangle anomaly. Within the frameworks of chiral perturbation theory at leading small-momenta expansion as well as the Nambu--Jona-Lasinio model at leading $1/N_c$ expansion, we quantify the dependence of the $\\pi^0$ condensate on $I_2$. The stability of the $\\pi^0$-condensed vacuum against the Schwinger charged pair production due to electric field is also discussed.
Spacetime algebra as a powerful tool for electromagnetism
Justin Dressel; Konstantin Y. Bliokh; Franco Nori
2015-06-02T23:59:59.000Z
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.
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
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.
Measurement of radiofrequency fields
Leonowich, J.A.
1992-05-01T23:59:59.000Z
We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation and field below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields. 23 refs.
Texas at Austin. University of
Stopping supersonic oxygen with a series of pulsed electromagnetic coils: A molecular coilgun, using a series of pulsed electromagnetic coils. A series of coils is fired in a timed sequence to bring in some experiments by interactions with pulsed electric fields Stark decelerator 46 , by inter- actions
THE BIANCHI IDENTITIES, ELECTROMAGNETIC WAVES, AND CHARGE CONSERVATION IN THE P(4) THEORY OF
Norris, Larry K.
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
ON THE INFLUENCE OF THE GEOMETRY ON SKIN EFFECT IN ELECTROMAGNETISM
Dauge, Monique
ON THE INFLUENCE OF THE GEOMETRY ON SKIN EFFECT IN ELECTROMAGNETISM GABRIEL CALOZ, MONIQUE DAUGE #12;2 GABRIEL CALOZ, MONIQUE DAUGE, ERWAN FAOU, VICTOR PÂ´ERON electromagnetic field at high is larger Â and here the sign of the curvature has a major influence, which means that the skin depth
Range-gated field disturbance sensor with range-sensitivity compensation
McEwan, T.E.
1996-05-28T23:59:59.000Z
A field disturbance sensor operates with relatively low power, provides an adjustable operating range, is not hypersensitive at close range, allows co-location of multiple sensors, and is inexpensive to manufacture. The sensor includes a transmitter that transmits a sequence of transmitted bursts of electromagnetic energy. The transmitter frequency is modulated at an intermediate frequency. The sequence of bursts has a burst repetition rate, and each burst has a burst width and comprises a number of cycles at a transmitter frequency. The sensor includes a receiver which receives electromagnetic energy at the transmitter frequency, and includes a mixer which mixes a transmitted burst with reflections of the same transmitted burst to produce an intermediate frequency signal. Circuitry, responsive to the intermediate frequency signal indicates disturbances in the sensor field. Because the mixer mixes the transmitted burst with reflections of the transmitted burst, the burst width defines the sensor range. The burst repetition rate is randomly or pseudorandomly modulated so that bursts in the sequence of bursts have a phase which varies. 8 figs.
Range-gated field disturbance sensor with range-sensitivity compensation
McEwan, Thomas E. (Livermore, CA)
1996-01-01T23:59:59.000Z
A field disturbance sensor operates with relatively low power, provides an adjustable operating range, is not hypersensitive at close range, allows co-location of multiple sensors, and is inexpensive to manufacture. The sensor includes a transmitter that transmits a sequence of transmitted bursts of electromagnetic energy. The transmitter frequency is modulated at an intermediate frequency. The sequence of bursts has a burst repetition rate, and each burst has a burst width and comprises a number of cycles at a transmitter frequency. The sensor includes a receiver which receives electromagnetic energy at the transmitter frequency, and includes a mixer which mixes a transmitted burst with reflections of the same transmitted burst to produce an intermediate frequency signal. Circuitry, responsive to the intermediate frequency signal indicates disturbances in the sensor field. Because the mixer mixes the transmitted burst with reflections of the transmitted burst, the burst width defines the sensor range. The burst repetition rate is randomly or pseudorandomly modulated so that bursts in the sequence of bursts have a phase which varies.
Quasi light fields: Extending the light field to coherent radiation
Accardi, Anthony J.
Imaging technologies such as dynamic viewpoint generation are engineered for incoherent radiation using the traditional light field, and for coherent radiation using electromagnetic field theory. We present a model of ...
Richard H. Price; John W. Belcher; David A. Nichols
2012-12-19T23:59:59.000Z
We compare the nature of electromagnetic fields and of gravitational fields in linearized general relativity. We carry out this comparison both mathematically and visually. In particular the "lines of force" visualizations of electromagnetism are contrasted with the recently introduced tendex/vortex eigenline technique for visualizing gravitational fields. Specific solutions, visualizations, and comparisons are given for an oscillating point quadrupole source. Among the similarities illustrated are the quasistatic nature of the near fields, the transverse 1/r nature of the far fields, and the interesting intermediate field structures connecting these two limiting forms. Among the differences illustrated are the meaning of field line motion, and of the flow of energy.
Electromagnetic wave scattering by small bodies
A. G. Ramm
2008-04-21T23:59:59.000Z
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.
Electromagnetic simulations of coaxial type HOM coupler
Genfa Wu; Haipeng Wang; Robert Rimmer; Charles Reece
2005-07-10T23:59:59.000Z
DESY-type coaxial high order mode (HOM) coupler was used in many superconducting cavities. The electric probe tip is located at the maximum B-field inside the coupler can. For continuous wave (CW) high current application, the heating of this tip can be severe to degrade the cavity performance. Electromagnetic (EM) simulation was done to estimate the tip heating. The geometric remedies and detuning effect were discussed. The effect to HOM external quality factor (Qext) was also estimated due to these remedies. The HOM probe tip heating power was provided for CEBAF 12-GeV cavities and AES injector cavities.
Testing black hole candidates with electromagnetic radiation
Bambi, Cosimo
2015-01-01T23:59:59.000Z
Astrophysical black hole candidates are thought to be the Kerr black holes of general relativity, but there is currently no direct observational evidence that the spacetime geometry around these objects is described by the Kerr solution. The study of the properties of the electromagnetic radiation emitted by gas or stars orbiting these objects can potentially test the Kerr black hole hypothesis. In this paper, I review the state of the art of this research field, describing the possible approaches to test the Kerr metric with current and future observational facilities and discussing current constraints.
Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation
Novack, Steven D.; Kotter, Dale K.; Pinhero, Patrick J.
2012-10-09T23:59:59.000Z
Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.
Structures, systems and methods for harvesting energy from electromagnetic radiation
Novack, Steven D. (Idaho Falls, ID); Kotter, Dale K. (Shelley, ID); Pinhero, Patrick J. (Columbia, MO)
2011-12-06T23:59:59.000Z
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.
Keenan, Brett D; Medvedev, Mikhail V
2015-01-01T23:59:59.000Z
High-amplitude, chaotic/turbulent electromagnetic fluctuations are ubiquitous in high-energy-density laboratory and astrophysical plasmas, where they can be excited by various kinetic-streaming and/or anisotropy-driven instabilities, such as the Weibel instability. These fields typically exist on "sub-Larmor scales" -- scales smaller than the electron Larmor radius. Electrons moving through such magnetic fields undergo small-angle stochastic deflections of their pitch-angles, thus establishing diffusive transport on long time-scales. We show that this behavior, under certain conditions, is equivalent to Coulomb collisions in collisional plasmas. The magnetic pitch-angle diffusion coefficient, which acts as an effective "collision" frequency, may be substantial in these, otherwise, collisionless environments. We show that this effect, colloquially referred to as the plasma "quasicollisionality", may radically alter the expected radiative transport properties of candidate plasmas. We argue that the modified mag...
Interpretation of electromagnetic soundings in the Raft River...
configuration (which is designed to measure the vertical magnetic field (Hz) at the loop center for various frequencies); to present an example of the EM sounding data and...
Electromagnetic neutrinos in terrestrial experiments and astrophysics
Carlo Giunti; Konstantin A. Kouzakov; Yu-Feng Li; Alexey V. Lokhov; Alexander I. Studenikin; Shun Zhou
2015-06-17T23:59:59.000Z
An overview of neutrino electromagnetic properties, which open a door to the new physics beyond the Standard Model, is given. The effects of neutrino electromagnetic interactions both in terrestrial experiments and in astrophysical environments are discussed. The experimental bounds on neutrino electromagnetic characteristics are summarized. Future astrophysical probes of electromagnetic neutrinos are outlined.
Filling of a cavity with zero-point electromagnetic radiation
Jiri J. Mares; V. Spicka; J. Kristofik; P. Hubik
2003-11-11T23:59:59.000Z
In the present contribution we analyse a simple thought process at T = 0 in an idealized heat engine having partitions made of a material with an upper frequency cut-off and bathed in zero-point (ZP) electromagnetic radiation. As a result, a possible mechanism of filling real cavities with ZP radiation based on Doppler's effect has been suggested and corresponding entropy changes are discussed.
Electromagnetic Calorimeter for HADES
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
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.
Black Hole Thermodynamics and Electromagnetism
Burra G. Sidharth
2005-07-15T23:59:59.000Z
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.
Electromagnetic radiation and motion of arbitrarily shaped particle
Jozef Klacka
2001-07-06T23:59:59.000Z
Covariant form of equation of motion for arbitrarily shaped particle in the electromagnetic radiation field is presented. Equation of motion in the proper frame of the particle uses the radiation pressure cross section 3 $\\times$ 3 matrix. The obtained equation of motion is compared with known result.
College of Engineering Electromagnetically Enhanced Hydrocyclone for Magnetite Separation during
Demirel, Melik C.
during Overview Magnetite is used by Consol Energy to separate coal from waste rock by increasing the magnetic field patterns · An impeller was installed to continuously mix the slurry to keep the mixture Electromagnetically Enhanced Hydrocyclone for Magnetite Separation during Coal Beneficiation Magnetite is used
Novel microwave near-field sensors for material characterization, biology, and nanotechnology
Joffe, R; Shavit, R
2015-01-01T23:59:59.000Z
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.
Scattering of an ultrashort electromagnetic pulse in a plasma
Astapenko, V. A. [Moscow Institute of Physics and Technology (Russian Federation)
2011-11-15T23:59:59.000Z
An analytic approach is developed to describing how ultrashort electromagnetic pulses with a duration of one period or less at the carrier frequency are scattered in a plasma. Formulas are derived to calculate and analyze the angular and spectral probabilities of radiation scattering via two possible mechanisms-Compton and transition radiation channels-throughout the entire pulse. Numerical simulations were carried out for a Gaussian pulse. The effect of the phase of the carrier frequency relative to the pulse envelope on the scattering parameters is investigated.
Mode conversion and electron heating near the upper hybrid resonance frequency
Smith, B.L.; Okuda, H.; Abe, H.
1983-11-01T23:59:59.000Z
Mode conversion near the upper hybrid resonance frequency and electron heating are studied using a one-dimensional electromagnetic relativistic particle code. It is found that for a sufficiently small pump field E/sub 0/, E/sub 0//sup 2//4..pi..nT/sub e/ less than or equal to 0.01, electron heating is localized in a region near the electron cyclotron layer where the pump frequency is equal to the local electron gyrofrequency. For stronger pump fields, electron heating takes place more or less uniformly across a region between the upper hybrid resonance layer and the cyclotron layer. In addition, a significant fraction of electromagnetic energy associated with the pump is found to be reflected back into the vacuum from a region in the plasma near the upper hybrid resonance layer for both strong (E/sub 0//sup 2//4..pi..nT/sub e/ approx. = 1) and weak pumps (E/sub 0//sup 2//4..pi..nT/sub e/ << 1).
Electric and magnetic fields program overview
NONE
1995-09-01T23:59:59.000Z
DOE`s EMF Program is presented. The possibility of biological effects from electromagnetic fields created by electricity is examined. Current research at many National Laboratories is reviewed.
Neutral shells and their applications in the design of electromagnetic shields
Liu, Liping
resonance imaging (MRI) machines and tokamaks in magnetic confinement fusion [5, 37]. In addition) for precision measurements of magnetic fields [32]. Examples of shields for field confinement include magnetic a simple design of electromagnetic shields for both field expelling and field confinement. Motivated
Chu, Shih-I
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
Javey, Ali
) electronics on both conventional silicon and flexible substrates. KEYWORDS: III-V-on-insulator, XOI, two-dimensional membranes, radio frequency transistors, flexible electronics The growing demand on larger bandwidth, such HEMT devices are not compatible with flexible electronics, which has attracted significant amount
On the spontaneous emission of electromagnetic radiation in the CSL model
Donadi, Sandro, E-mail: sandro.donadi@ts.infn.it [Department of Physics, University of Trieste, Strada Costiera 11, 34151 Trieste (Italy) [Department of Physics, University of Trieste, Strada Costiera 11, 34151 Trieste (Italy); Istituto Nazionale di Fisica Nucleare, Trieste Section, Via Valerio 2, 34127 Trieste (Italy); Deckert, Dirk-André, E-mail: deckert@math.ucdavis.edu [Department of Mathematics, University of California, One Shields Ave, 95616 Davis (United States)] [Department of Mathematics, University of California, One Shields Ave, 95616 Davis (United States); Bassi, Angelo, E-mail: bassi@ts.infn.it [Department of Physics, University of Trieste, Strada Costiera 11, 34151 Trieste (Italy) [Department of Physics, University of Trieste, Strada Costiera 11, 34151 Trieste (Italy); Istituto Nazionale di Fisica Nucleare, Trieste Section, Via Valerio 2, 34127 Trieste (Italy)
2014-01-15T23:59:59.000Z
Spontaneous photon emission in the Continuous Spontaneous Localization (CSL) model is studied one more time. In the CSL model each particle interacts with a noise field that induces the collapse of its wave function. As a consequence of this interaction, when the particle is electrically charged, it radiates. As discussed in Adler (2013) the formula for the emission rate, to first perturbative order, contains two terms: one is proportional to the Fourier component of the noise field at the same frequency as that of the emitted photon and one is proportional to the zero Fourier component of the noise field. As discussed in previous works, this second term seems unphysical. In Adler (2013) it was shown that the unphysical term disappears when the noise is confined to a bounded region and the final particle’s state is a wave packet. Here we investigate the origin of this unphysical term and why it vanishes according to the previous prescription. We will see that perturbation theory is formally not valid in the large time limit since the effect of the noise accumulates continuously in time. Therefore either one performs an exact calculation (or at least in some way includes higher order terms) as we do here, or one finds a way to make a perturbative calculation meaningful, e.g., by confining the system as in Adler (2013). -- Highlights: •We compute the electromagnetic radiation emission in collapse models. •Under only the dipole approximation, the equations of motion are solved exactly. •The electromagnetic interaction must be treated exactly. •In order to obtain the correct emission rate the particle must be bounded.
Electromagnetic low-energy constants in ChPT
Christoph Haefeli; Mikhail A. Ivanov; Martin Schmid
2007-10-29T23:59:59.000Z
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.
Analog Electromagnetism in a Symmetrized $^3$He-A
Jacek Dziarmaga
2001-12-18T23:59:59.000Z
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.
Graded pitch electromagnetic pump for thin strip metal casting systems
Kuznetsov, S.B.
1986-04-01T23:59:59.000Z
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.
Graded pitch electromagnetic pump for thin strip metal casting systems
Kuznetsov, Stephen B. (Pittsburgh, PA)
1986-01-01T23:59:59.000Z
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.
Application of evolutionary algorithms and neural networks to electromagnetic inverse problems
Mydur, Ravicharan
2000-01-01T23:59:59.000Z
This research investigates the imaging of buried two-dimensional objects (conducting cylinders and air tunnels) of various shapes, by processing the scattered electromagnetic field under Transverse Magnetic (TM) and Transverse Electric (TE...
Fernandes, Roland Anthony Savio
2009-05-15T23:59:59.000Z
Controlled source electromagnetic (CSEM) geophysics has been used with a fair amount of success in near surface hydrogeological studies. Recently, these investigations have been conducted frequently in human impacted field sites containing cultural...
A. V. Borisov; P. E. Sizin
2014-06-12T23:59:59.000Z
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.
Application of evolutionary algorithms and neural networks to electromagnetic inverse problems
Mydur, Ravicharan
2000-01-01T23:59:59.000Z
This research investigates the imaging of buried two-dimensional objects (conducting cylinders and air tunnels) of various shapes, by processing the scattered electromagnetic field under Transverse Magnetic (TM) and Transverse Electric (TE...
Sun, Qingqing; Shahriar, M. Selim; Zubairy, M. Suhail
2008-01-01T23:59:59.000Z
We investigate the effect of electromagnetically induced transparency inside a laser cavity. By changing the intensity of an external drive field, we can control the absorption to the laser field. A semiclassical analysis shows that the system...
Self-consistent electrodynamics of large-area high-frequency capacitive plasma discharge
Chen Zhigang; Rauf, Shahid; Collins, Ken [Applied Materials, Inc., 974 E. Arques Avenue, Sunnyvale, California 94085 (United States)
2010-10-15T23:59:59.000Z
Capacitively coupled plasmas (CCPs) generated using high frequency (3-30 MHz) and very high frequency (30-300 MHz) radio-frequency (rf) sources are used for many plasma processing applications including thin film etching and deposition. When chamber dimensions become commensurate with the effective rf wavelength in the plasma, electromagnetic wave effects impose a significant influence on plasma behavior. Because the effective rf wavelength in plasma depends upon both rf and plasma process conditions (e.g., rf power and gas pressure), a self-consistent model including both the rf power delivery system and the plasma discharge is highly desirable to capture a more complete physical picture of the plasma behavior. A three-dimensional model for self-consistently studying both electrodynamic and plasma dynamic behavior of large-area (Gen 10, >8 m{sup 2}) CCP is described in this paper. This model includes Maxwell's equations and transport equations for charged and neutral species, which are coupled and solved in the time domain. The complete rf plasma discharge chamber including the rf power delivery subsystem, rf feed, electrodes, and the plasma domain is modeled as an integrated system. Based on this full-wave solution model, important limitations for processing uniformity imposed by electromagnetic wave propagation effects in a large-area CCP (3.05x2.85 m{sup 2} electrode size) are studied. The behavior of H{sub 2} plasmas in such a reactor is examined from 13.56 to 200 MHz. It is shown that various rectangular harmonics of electromagnetic fields can be excited in a large-area rectangular reactor as the rf or power is increased. The rectangular harmonics can create not only center-high plasma distribution but also high plasma density at the corners and along the edges of the reactor.
Quasi light fields: extending the light field to coherent radiation
Wornell, Gregory W.
Quasi light fields: extending the light field to coherent radiation Anthony Accardi1,2 and Gregory light field, and for coherent radiation using electromagnetic field theory. We present a model of coherent image formation that strikes a balance between the utility of the light field
On the electromagnetic constitutive laws that are equivalent to spacetime metrics
D. H. Delphenich
2014-09-17T23:59:59.000Z
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.
Surface electromagnetic wave equations in a warm magnetized quantum plasma
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
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.
Breit-Wheeler process in very short electromagnetic pulses
A. I. Titov; B. Kampfer; H. Takabe; A. Hosaka
2013-03-26T23:59:59.000Z
The generalized Breit-Wheeler process, i.e. the emission of $e^+e^-$ pairs off a probe photon propagating through a polarized short-pulsed electromagnetic (e.g.\\ laser) wave field, is analyzed. We show that the production probability is determined by the interplay of two dynamical effects. The first one is related to the shape and duration of the pulse and the second one is the non-linear dynamics of the interaction of $e^\\pm$ with the strong electromagnetic field. The first effect manifests itself most clearly in the weak-field regime, where the small field intensity is compensated by the rapid variation of the electromagnetic field in a limited space-time region, which intensifies the few-photon events and can enhance the production probability by orders of magnitude compared to an infinitely long pulse. Therefore, short pulses may be considered as a powerful amplifier. The non-linear dynamics in the multi-photon Breit-Wheeler regime plays a decisive role at large field intensities, where effects of the pulse shape and duration are less important. In the transition regime, both effects must be taken into account simultaneously. We provide suitable expressions for the $e^+e^-$ production probability for kinematic regions which can be used in transport codes.
Electromagnetic Waves Propagation in 3D Plasma Configurations
is the optimisation of low-frequency plasma heating systems in stellarators. The aim is to develop a code that will allow for the calculation of the fields and energy deposition of a low-frequency wave propagating-wave interaction is modelled by a full cold-plasma dielectric tensor, including the parallel electric field term
Scattering of an ultrashort electromagnetic radiation pulse by an atom in a broad spectral range
Astapenko, V. A., E-mail: astval@mail.ru [Moscow Institute of Physics and Technology (Russian Federation)
2011-02-15T23:59:59.000Z
The scattering of an ultrashort electromagnetic pulse by atomic particles is described using a consistent quantum-mechanical approach taking into account excitation of a target and nondipole electromagnetic interaction, which is valid in a broad spectral range. This approach is applied to the scattering of single- and few-cycle pulses by a multielectron atom and a hydrogen atom. Scattering spectra are obtained for ultrashort pulses of different durations. The relative contribution of 'elastic' scattering of a single-cycle pulse by a hydrogen atom is studied in the high-frequency limit as a function of the carrier frequency and scattering angle.
Evolution of linearly polarized electromagnetic pulses in laser plasmas
Borhanian, J. [Department of Atomic and Molecular Physics, Faculty of Physics, University of Tabriz 51664 (Iran, Islamic Republic of); Centre for Plasma Physics, Department of Physics and Astronomy, Queen's University Belfast, BT7 1NN, Northern Ireland (United Kingdom); Sobhanian, S. [Department of Atomic and Molecular Physics, Faculty of Physics, University of Tabriz 51664 (Iran, Islamic Republic of); Kourakis, I. [Centre for Plasma Physics, Department of Physics and Astronomy, Queen's University Belfast, BT7 1NN, Northern Ireland (United Kingdom); Esfandyari-Kalejahi, A. [Department of Physics, Faculty of Science, Azarbaijan University of Tarbiat Moallem, Tabriz 51745-406 (Iran, Islamic Republic of)
2008-09-15T23:59:59.000Z
An analytical and numerical investigation is presented of the behavior of a linearly polarized electromagnetic pulse as it propagates through a plasma. Considering a weakly relativistic regime, the system of one-dimensional fluid-Maxwell equations is reduced to a generalized nonlinear Schroedinger type equation, which is solved numerically using a split step Fourier method. The spatio-temporal evolution of an electromagnetic pulse is investigated. The evolution of the envelope amplitude of density harmonics is also studied. An electromagnetic pulse propagating through the plasma tends to broaden due to dispersion, while the nonlinear frequency shift is observed to slow down the pulse at a speed lower than the group velocity. Such nonlinear effects are more important for higher density plasmas. The pulse broadening factor is calculated numerically, and is shown to be related to the background plasma density. In particular, the broadening effect appears to be stronger for dense plasmas. The relation to existing results on electromagnetic pulses in laser plasmas is discussed.
Electromagnetic radiation by gravitating bodies
Iwo Bialynicki-Birula; Zofia Bialynicka-Birula
2008-05-06T23:59:59.000Z
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.
Parametric study of high altitude nuclear EMP fields. Master's thesis
Lavigne, R.J.
1984-03-01T23:59:59.000Z
A program is developed to model the electromagnetic pulse from a high altitude nuclear detonation. A Runge-Kutta numerical technique is used to solve for the electric fields. A continuous Fourier Transform of the EMP is used to determine the frequency profile of the EMP. Parametric studies are performed to determine cause and effect relationships between burst parameters and the EMP frequency profile from 100 KHz to 100 MHz. Burst parameters studied are: gamma pulse time history, gamma ray energies from 1 MeV to 10 MeV, gamma ray yield, height of burst from 75 Km to 200 Km and intersection angle of the slant range with the geomagnetic field from 90 degrees to 30 degrees.
Electromagnetic formation flight dipole solution planning
Schweighart, Samuel A. (Samuel Adam), 1977-
2005-01-01T23:59:59.000Z
Electromagnetic Formation Flight (EMFF) describes the concept of using electromagnets (coupled with reaction wheels) to provide all of the necessary forces and torques needed to maintain a satellite's relative position and ...
A modified Bitter-type electromagnet and control system for cold atom experiments
Luan, Tian; Zhou, Tianwei; Chen, Xuzong, E-mail: xuzongchen@pku.edu.cn [School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China)] [School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China); Ma, Zhaoyuan, E-mail: zyma@siom.cas.cn [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)] [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)
2014-02-15T23:59:59.000Z
We present a modified Bitter-type electromagnet which features high magnetic field, fine electronic properties and efficient heat removal. The electromagnet is constructed from a stack of copper layers separated by mica layers that have the same shape. A distinctive design of cooling channels on the insulating layers and the parallel ducts between the layers ensures low resistance for cooling water to flow. A continuous current control system is also made to regulate the current through the electromagnet. In our experiment, versatile electromagnets are applied to generate magnetic field and gradient field. From our measurements, a peak magnetic field of 1000 G and a peak gradient field of 80 G/cm are generated in the center of the apparatuses which are 7 cm and 5 cm away from the edge of each electromagnet with a current of 230 A and 120 A, respectively. With the effective feedback design in the current control system and cooling water flow of 3.8 l/min, the stability of the current through the electromagnets can reach 10{sup ?5}.
Electromagnetic Induced Gravitational Perturbations
T. M. Adamo; E. T. Newman
2008-07-23T23:59:59.000Z
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.
Qi, Zumin; Zhang, Jun; Zhong, Huihuang; Zhang, Qiang; Zhu, Danni [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China)
2014-07-15T23:59:59.000Z
Suppression of the transverse-electromagnetic (TEM) mode leakage is crucial in the design of a triaxial klystron amplifier with high gain, because a small microwave leakage from the buncher or the output cavity could overwhelm the input signal with low power. In this paper, a specially designed reflector is proposed to suppress the TEM mode leakage, whose axial electric field is approximately zero at the beam radial position. Theoretical analysis indicates that the reflector introduces little influence on the normal modulation of the beam while keeping a high reflection coefficient. By using two such reflectors with different eigen frequencies located in front of the buncher cavity and the output cavity, respectively, an improved triaxial klystron amplifier is presented. The simulation results show that the reflectors substantially decrease the TEM mode leakage power and achieve very good isolation among the cavities. The improved triaxial klystron amplifier can operate normally with 10's kW microwave injection without self-oscillations.
Hanson, George
in radiofrequency-terahertz heating of nanoparticles G. W. Hanson,1,a) R. C. Monreal,2 and S. P. Apell3 1 Department on the absorption of electromagnetic radiation by metallic nanoparticles in the radio and far infrared frequency by which nonmagnetic metallic nanoparticles can absorb low frequency radiation, including both classical
Electromagnetic Formation Flight of Satellite Arrays
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
611: Electromagnetic Theory Problem Sheet 5
Pope, Christopher
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
611: Electromagnetic Theory Problem Sheet 7
Pope, Christopher
611: Electromagnetic Theory Problem Sheet 7 (1) Consider the non-relativistic motion of a particle momentum of the particle about the centre of the force at r = 0.) (2a) Consider an electromagnetic wave the energy density and the Poynting vector. (2c) Repeat the steps in (2a) and (2b) for an electromagnetic
Electromagnetic Corrections in Staggered Chiral Perturbation Theory
Bernard, Claude
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
Electromagnetic Interrogation of Dielectric Materials 1
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
Electromagnetic and nuclear radiation detector using micromechanical sensors
Thundat, Thomas G. (Knoxville, TN); Warmack, Robert J. (Knoxville, TN); Wachter, Eric A. (Oak Ridge, TN)
2000-01-01T23:59:59.000Z
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.
Compression of laser radiation in plasmas via electromagnetic cascading
Kalmykov, Serguei; Shvets, Gennady [Department of Physics and Institute for Fusion Studies, University of Texas at Austin, One University Station C1500, Austin, Texas 78712 (United States)
2006-05-15T23:59:59.000Z
A train of few-laser-cycle relativistically intense radiation spikes with a terahertz repetition rate can be organized self-consistently in plasma from two frequency detuned co-propagating laser beams of low intensity. Large frequency bandwidth for the compression of spikes is produced via laser-induced periodic modulation of the plasma refractive index. The beat-wave-driven electron plasma wave downshifted from the plasma frequency creates a moving index grating thus inducing a periodic phase modulation of the driving laser (in spectral terms, electromagnetic cascading). The group velocity dispersion compresses the chirped laser beat notes to a few-cycle duration and relativistic intensity either concurrently in the same, or sequentially in different plasmas. Particle-in-cell simulations indicate that the effect persists in a realistic three-dimensional axisymmetric geometry.
Vibration Harvesting using Electromagnetic Transduction
Waterbury, Andrew
2011-01-01T23:59:59.000Z
harvesting Microelectromechanical systems (MEMS) are smallMEMS Vibration Energy Harvesting Devices With Passive Resonance Frequency Adaptation Capability,” Microelectromechanical
Efficient regime of electromagnetic emission in a plasma with counterstreaming electron beams
Timofeev, I. V.; Annenkov, V. V. [Budker Institute of Nuclear Physics SB RAS and Novosibirsk State University, 630090 Novosibirsk (Russian Federation)
2014-08-15T23:59:59.000Z
Efficiency of electromagnetic emission produced in a magnetized plasma with counterstreaming electron beams was investigated using both the linear kinetic theory and particle-in-cell simulations. We calculated the growth rate of the beam-plasma instability taking into account both kinetic and relativistic effects and showed that there exists a regime in which transversely propagating electromagnetic waves can be generated by the coupling of the most unstable oblique beam-driven modes. It was confirmed by numerical simulations that such a tune-up of system parameters for a specific nonlinear process can lead to a substantial increase in electromagnetic emission efficiency. It was found that electromagnetic radiation emerging from the plasma in such a regime is generated near the harmonics of the pump frequency that is determined by the typical eigenfrequency of the beam-driven modes. It was also shown that the peak emission power can reach 5% of the maximal power lost by beam electrons.
Fan, Yu; Zou, Ying; Sun, Jizhong; Wang, Dezhen [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Stirner, Thomas [Department of Electronic Engineering, University of Applied Sciences Deggendorf, Edlmairstr. 6-8, D-94469 Deggendorf (Germany)] [Department of Electronic Engineering, University of Applied Sciences Deggendorf, Edlmairstr. 6-8, D-94469 Deggendorf (Germany)
2013-10-15T23:59:59.000Z
The influence of an applied magnetic field on plasma-related devices has a wide range of applications. Its effects on a plasma have been studied for years; however, there are still many issues that are not understood well. This paper reports a detailed kinetic study with the two-dimension-in-space and three-dimension-in-velocity particle-in-cell plus Monte Carlo collision method on the role of E×B drift in a capacitive argon discharge, similar to the experiment of You et al.[Thin Solid Films 519, 6981 (2011)]. The parameters chosen in the present study for the external magnetic field are in a range common to many applications. Two basic configurations of the magnetic field are analyzed in detail: the magnetic field direction parallel to the electrode with or without a gradient. With an extensive parametric study, we give detailed influences of the drift on the collective behaviors of the plasma along a two-dimensional domain, which cannot be represented by a 1 spatial and 3 velocity dimensions model. By analyzing the results of the simulations, the occurring collisionless heating mechanism is explained well.
Electromagnetic acoustic transducer
Alers, George A. (Albuquerque, NM); Burns, Jr., Leigh R. (Albuquerque, NM); MacLauchlan, Daniel T. (Sandia Park, NM)
1988-01-01T23:59:59.000Z
A noncontact ultrasonic transducer for studying the acoustic properties of a metal workpiece includes a generally planar magnetizing coil positioned above the surface of the workpiece, and a generally planar eddy current coil between the magnetizing coil and the workpiece. When a large current is passed through the magnetizing coil, a large magnetic field is applied to the near-surface regions of the workpiece. The eddy current coil can then be operated as a transmitter by passing an alternating current therethrough to excite ultrasonic waves in the surface of the workpiece, or operated as a passive receiver to sense ultrasonic waves in the surface by measuring the output signal. The geometries of the two coils can be varied widely to be effective for different types of ultrasonic waves. The coils are preferably packaged in a housing which does not interfere with their operation, but protects them from a variety of adverse environmental conditions.
Oldenburg, Douglas W.
Comparison of integral equation and physical scale modeling of the electromagnetic responses geophysical electromagnetic responses: a numerical approach based upon the electric-field integral equa- tion and the physical scale modeling approach. The particular implementation of the integral-equation solution
Kotter, Dale K. (Shelley, ID) [Shelley, ID; Rohrbaugh, David T. (Idaho Falls, ID) [Idaho Falls, ID
2010-09-07T23:59:59.000Z
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.
Nuclear electromagnetic pulse (EMP) and electric power systems
Barnes, P.R.; Vance, E.F.; Askins, H.W. Jr.
1984-04-01T23:59:59.000Z
A nuclear detonation at high altitudes produces a transient electromagnetic pulse (EMP) of high-intensity electromagnetic fields. A single high-altitude burst can subject most of the continental United States to a strong EMP. These intense fields induce voltage and current transients in electrical conductors. Surges would be induced by EMP in transmission and distribution circuits and in control and communication elements in electric power systems throughout the national grid. Such widespread disturbances could upset the stability of electrical energy systems and result in massive power failures. The extent and nature of EMP-caused damages are not well known for utility electric power systems. Failures are likely to be associated with insulation damage and failures of low-voltage and solid-state components. It is concluded from a review of past studies that EMP may pose a serious threat to the nation's electrical energy supply.