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1

Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments  

E-print Network

of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energyTable of Nuclear Magnetic Dipole and Electric Quadrupole Moments N.J.Stone, Oxford Physics, Clarendon Laboratory Parks Road, OXFORD OX1 3PU U.K. This Table is a compilation of experimental

2

Dynamically fluctuating electric dipole moments in fullerene-based magnets  

NASA Astrophysics Data System (ADS)

We report here the direct evidence of the existence of a permanent electric dipole moment in both crystal phases of a fullerene-based magnet--the ferromagnetic ?-phase and the antiferromagnetic ?'-phase of tetra-kis-(dimethylamino)-ethylene-C60 (TDAE-C60)--as determined by dielectric measurements. We propose that the permanent electric dipole originates from the pairing of a TDAE molecule with surrounding C60 molecules. The two polymorphs exhibit clear differences in their dielectric responses at room temperature and during the freezing process with dynamically fluctuating electric dipole moments, although no difference in their room-temperature structures has been previously observed. This result implies that two polymorphs have different local environment around the molecules. In particular, the ferromagnetism of the ?-phase is founded on the homogeneous molecule displacement and orientational ordering. The formation of the different phases with respect to the different rotational states in the Jahn-Teller distorted C60s is also discussed.

Kambe, Takashi; Oshima, Kokichi

2014-09-01

3

Atomic electric dipole moment induced by the nuclear electric dipole moment: The magnetic moment effect  

SciTech Connect

We have considered a mechanism for inducing a time-reversal violating electric dipole moment (EDM) in atoms through the interaction of a nuclear EDM d{sub N} with the hyperfine interaction, the ''magnetic moment effect''. We have derived the operator for this interaction and presented analytical formulas for the matrix elements between atomic states. Induced EDMs in the diamagnetic atoms {sup 129}Xe, {sup 171}Yb, {sup 199}Hg, {sup 211}Rn, and {sup 225}Ra have been calculated numerically. From the experimental limits on the atomic EDMs of {sup 129}Xe and {sup 199}Hg we have placed the following constraints on the nuclear EDMs, |d{sub N}({sup 129}Xe)|<1.1x10{sup -21}|e|cm and |d{sub N}({sup 199}Hg)|<2.8x10{sup -24}|e|cm.

Porsev, S. G. [School of Physics, University of New South Wales, Sydney NSW 2052 (Australia); Petersburg Nuclear Physics Institute, Gatchina, Leningrad district 188300 (Russian Federation); Ginges, J. S. M.; Flambaum, V. V. [School of Physics, University of New South Wales, Sydney NSW 2052 (Australia)

2011-04-15

4

Magnetic and Electric Dipole Constraints on Extra Dimensions and Magnetic Fluxes  

E-print Network

The propagation of charged particles and gauge fields in a compact extra dimension contributes to $g-2$ of the charged particles. In addition, a magnetic flux threading this extra dimension generates an electric dipole moment for these particles. We present constraints on the compactification size and on the possible magnetic flux imposed by the comparison of data and theory of the magnetic moment of the muon and from limits on the electric dipole moments of the muon, neutron and electron.

Aaron J. Roy; Myron Bander

2008-05-10

5

Dynamically fluctuating electric dipole moments in fullerene-based magnets  

PubMed Central

We report here the direct evidence of the existence of a permanent electric dipole moment in both crystal phases of a fullerene-based magnet—the ferromagnetic ?-phase and the antiferromagnetic ??-phase of tetra-kis-(dimethylamino)-ethylene-C60 (TDAE-C60)—as determined by dielectric measurements. We propose that the permanent electric dipole originates from the pairing of a TDAE molecule with surrounding C60 molecules. The two polymorphs exhibit clear differences in their dielectric responses at room temperature and during the freezing process with dynamically fluctuating electric dipole moments, although no difference in their room-temperature structures has been previously observed. This result implies that two polymorphs have different local environment around the molecules. In particular, the ferromagnetism of the ?-phase is founded on the homogeneous molecule displacement and orientational ordering. The formation of the different phases with respect to the different rotational states in the Jahn–Teller distorted C60s is also discussed. PMID:25236361

Kambe, Takashi; Oshima, Kokichi

2014-01-01

6

Table of nuclear magnetic dipole and electric quadrupole moments  

SciTech Connect

The table is a compilation of experimental measurements of static magnetic dipole and electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin, and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. The literature search covers the period to late 2004. Many of the entries prior to 1988 follow those in Raghavan [At. Data Nucl. Data Tables 42 (1989) 189].

Stone, N.J. [Oxford Physics, Clarendon Laboratory, Oxford OX1 3PU (United Kingdom)]. E-mail: n.stone1@physics.oxford.ac.uk

2005-05-01

7

Electron scattering in graphene by impurities with electric and magnetic dipole moments  

NASA Astrophysics Data System (ADS)

The elastic electron scattering by impurities with electric and magnetic dipoles in graphene is studied with the help of Born approximation. Both types of scatterers give the nonzero cross section of backscattering. The scattering by the impurities with electric dipoles is more efficient even comparing to the scattering by the nanomagnets with anomalous magnetic moments. A comparison of the electron scattering transport cross sections by charged impurities and impurities with electric dipole moments shows that they can be comparable. The scattering by the impurities electric dipoles can be important in limiting the electron mobility in graphene along with the Coulomb scattering.

Mal'nev, V. N.; Senbeta, Teshome; Achenefe, Yohannes

2014-06-01

8

Simple estimation of equivalent magnetic dipole moment to characterize ELF magnetic fields generated by electric appliances incorporating harmonics  

Microsoft Academic Search

A simple method of quantifying the ELF (extremely low frequency) magnetic field distribution around electric appliances, which takes the harmonics into account, is newly proposed. The proposed method involves: (1) a simple estimation of the position of an equivalent magnetic dipole moment inside an appliance, using two magnetic field meters; (2) identification of the amplitude of the dipole moment magnetic-field

Kenichi Yamazaki; Tadashi Kawamoto

2001-01-01

9

CONDENSED MATTER: ELECTRONICSTRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Magnetoelectric Coupling Induced Electric Dipole Glass State in Heisenberg Spin Glass  

Microsoft Academic Search

Multiferroic behavior in an isotropic Heisenberg spin glass with Gaussian random fields, incorporated by magneto-electric coupling derived from the Landau symmetry argument, are investigated. Electric dipole glass transitions at finite temperature, due to coupling, are demonstrated by Monte Carlo simulation. This electric dipole glass state is solely ascribed to the coupling term with chiral symmetry of the magnetization, while the

Jun-Ming Liu; Lai-Wa Chan-wong; Chung-Loong Choy

2009-01-01

10

CONDENSED MATTER: ELECTRONICSTRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Magnetoelectric Coupling Induced Electric Dipole Glass State in Heisenberg Spin Glass  

NASA Astrophysics Data System (ADS)

Multiferroic behavior in an isotropic Heisenberg spin glass with Gaussian random fields, incorporated by magneto-electric coupling derived from the Landau symmetry argument, are investigated. Electric dipole glass transitions at finite temperature, due to coupling, are demonstrated by Monte Carlo simulation. This electric dipole glass state is solely ascribed to the coupling term with chiral symmetry of the magnetization, while the term associated with the spatial derivative of the squared magnetization has no contribution.

Liu, Jun-Ming; Chan-wong, Lai-Wa; Choy, Chung-Loong

2009-08-01

11

Purely electric and magnetic dipole resonances in metamaterial dielectric resonators through perturbation theory inspired geometries  

E-print Network

In this paper we describe a methodology for tailoring the design of metamaterial dielectric resonators, which represent a promising path toward low-loss metamaterials at optical frequencies. We first describe a procedure to decompose the far field scattered by subwavelength resonators in terms of multipolar field components, providing explicit expressions for the multipolar far fields. We apply this formulation to confirm that an isolated high-permittivity cube resonator possesses frequency separated electric and magnetic dipole resonances, as well as a magnetic quadrupole resonance in close proximity to the electric dipole resonance. We then introduce multiple dielectric gaps to the resonator geometry in a manner suggested by perturbation theory, and demonstrate the ability to overlap the electric and magnetic dipole resonances, thereby enabling directional scattering by satisfying the first Kerker condition. We further demonstrate the ability to push the quadrupole resonance away from the degenerate dipole ...

Campione, Salvatore; Warne, Larry K; Sinclair, Michael B

2014-01-01

12

The Energy Flow and Frequency Spectrum about Electric and Magnetic Dipoles.  

NASA Astrophysics Data System (ADS)

This dissertation investigates the properties of time dependent fields about electric and magnetic dipoles. Generalized expressions for the frequency spectrum and energy flux are obtained, and these expressions are applied in a variety of cases of physical interest. The concept of a "causal surface" through which no electromagnetic energy flows is established and applied to the case of an exponentially decaying dipole. I find that there exists a spherical surface of radius r=c tau (where tau is the time constant of the decay) around the decaying dipole through which no net energy flows. As further confirmation, I show that the total energy radiated is equal to the energy stored in the original static field outside this surface before the decay. Interestingly, this result suggests that the radiated energy comes not from the accelerating charges that constitute the dipole, but rather from the energy stored outside the causal surface. I also describe the interesting case of an oscillating electric dipole coupled to an oscillating magnetic dipole and explain the circumstances under which the Poynting flux becomes time invariant. Further, I present and prove some general theorems regarding the energy flow about electric and magnetic dipoles with periodic time dependence. I show that the net radial energy flow per period is exactly equal to the radiated energy, and I show that there is no net angular energy flow. The frequency spectrum is of particular concern in the context of electromagnetic interference and compatibility testing. This dissertation presents a theoretical model of the spectrum of radiation emitted by digital circuitry.

Schantz, Hans Gregory

13

Bond polarizability and vibronic coupling theories of Raman optical activity: The electric-dipole magnetic-dipole optical activity tensor  

NASA Astrophysics Data System (ADS)

A new formulation of the bond polarizability and vibronic coupling theories of Raman optical activity (ROA) is presented in which terms dependent upon the nuclear momentum are introduced for the first time. The new terms appear in the magnetic-dipole electric-dipole optical activity tensor and are directly analogous to the non-Born-Oppenheimer, momentum-dependent terms required in the formulation of the theory of vibrational circular dichroism. Through the use of simplifying approximations in the ROA vibronic coupling theory, a term-for-term correspondence with the bond polarizability theory is established. It is shown that the new terms are smaller than the original terms by the ratio of the vibrational transition frequency to the frequency of the incident radiation. The new terms also contribute oppositely to Stokes and anti-Stokes ROA which provides a basis for their experimental isolation.

Escribano, Juan R.; Freedman, Teresa B.; Nafie, Laurence A.

1987-09-01

14

Plasma-surface interaction in magnetic dipole fields: Understanding the near surface electrical environment in magnetic anomaly regions  

NASA Astrophysics Data System (ADS)

The Moon has no global magnetic field, only localized crustal magnetic anomalies. In-situ measurements have shown evidence for complex solar wind plasma interaction with these local magnetic fields, and indicated a strong correlation with the high-albedo markers on the lunar surface, so-called the lunar swirls. Due to the limitations of existing in-orbit and surface measurements, laboratory studies and computer simulations play important roles in understanding the near-surface/surface electric field environment in the magnetic anomaly regions. In laboratory experiments, we investigate plasma-surface interaction in a magnetic dipole field with magnetized electrons but unmagnetized ions to emulate the interaction of the solar wind with the lunar surface in moderate magnetic anomalies. We have studied the electric potential distributions above an insulating surface in a dipole field with the dipole axis parallel (0 degree) to the surface in plasma [Wang et al., 2012]. Here, we report on a complementary new study with the dipole field axes at 90 and 45 degrees to the surface. The dipole field is created with a cylindrical permanent magnet. When the dipole axis is normal to the surface, the surface potential in the central cusp region rises to more positive values than outside the field, and a bump-like potential structure emerges in the sheath above the surface. These results indicate a significant population of reflected electrons due to the magnetic mirror effect in the cusp region. The potential-bump structure diminishes when the plasma density and neutral pressure increase. A different vertical dipole field is created with a smaller-sized cylindrical magnet, which has a similar strength peaked at the central surface but decreases faster with the height. Our data shows that the potential bump moves closer to the surface and the rise in surface potential in the central cusp region is less than that above the larger-sized magnet. Two-dimensional potential contours above the surface with the 45 degrees dipole field are measured as well. The results from different field configurations show self-consistency. The implications of the laboratory results for the electric environment in lunar magnetic anomaly regions will be discussed. Wang, X., M. Horányi, S. Robertson, "Characteristics of a plasma sheath in a magnetic dipole field: Implications to the solar wind interaction with the lunar magnetic anomalies", J. Geophys. Res., 117, A06226 (2012).

Wang, X.; Howes, C.; Horanyi, M.; Robertson, S. H.

2012-12-01

15

W radiative decays and the determination of magnetic dipole and electric quadrupole moments of the W  

NASA Astrophysics Data System (ADS)

The magnetic dipole moment of the W boson is given by ?=e(1+?+?)/2MW and its electric quadrupole moment is given by Q=-e(?-?)/M2W. A nonstandard magnetic dipole moment and a nonstandard electric quadrupole moment lead to different differential decay distributions in the radiative decays of W+/-, W--->e?¯? and W--->du¯?. While hard photons are characteristic signatures of ??1 there is no such explicit signal for ??0. We present a technique for the determination of the values of ? and ? by measuring the total number of events in two regions of phase space. This experiment could be done at the CERN e+e- collider LEP II, where a clean source of W bosons will be available.

Samuel, Mark A.; Sinha, Nita; Sinha, Rahul; Sundaresan, M. K.

1991-10-01

16

Development of Active Magnetic Shielding for the Neutron Electric Dipole Moment Experiment at TRIUMF  

NASA Astrophysics Data System (ADS)

Active magnetic shielding has been proposed to provide low-frequency magnetic field stability in the neutron electric dipole moment (nEDM) experiment planned for TRIUMF. A prototype active magnetic shielding system was constructed and tested at the University of Winnipeg. The system is capable of providing RMS shielding factors > 1000 for magnetic field perturbation frequencies ? 20 mHz, and > 100 for frequencies ? 0.5 Hz, and can reduce magnetic field variations on the order of tens of muT to the level of tens of nT. The achievable shielding factor was limited by the field sampling rate limit of ~400 Hz, and by the background fi eld noise floor of the laboratory. This represents good progress towards the eventual system for nEDM experiments, where low-frequency field drifts on the order of 100 nT require active shielding to the order of 1 nT.

Lang, Michael Loren

17

Magnetic and electric dipole moments of the H {sup 3}{Delta}{sub 1} state in ThO  

SciTech Connect

The metastable H {sup 3}{Delta}{sub 1} state in the thorium monoxide (ThO) molecule is highly sensitive to the presence of a CP-violating permanent electric dipole moment of the electron (eEDM) [E. R. Meyer and J. L. Bohn, Phys. Rev. A 78, 010502 (2008)]. The magnetic dipole moment {mu}{sub H} and the molecule-fixed electric dipole moment D{sub H} of this state are measured in preparation for a search for the eEDM. The small magnetic moment {mu}{sub H}=8.5(5)x10{sup -3} {mu}{sub B} displays the predicted cancellation of spin and orbital contributions in a {sup 3}{Delta}{sub 1} paramagnetic molecular state, providing a significant advantage for the suppression of magnetic field noise and related systematic effects in the eEDM search. In addition, the induced electric dipole moment is shown to be fully saturated in very modest electric fields (<10 V/cm). This feature is favorable for the suppression of many other potential systematic errors in the ThO eEDM search experiment.

Vutha, A. C.; Kirilov, E.; DeMille, D. [Department of Physics, Yale University, New Haven, Connecticut 06520 (United States); Spaun, B.; Gurevich, Y. V.; Hutzler, N. R.; Doyle, J. M.; Gabrielse, G. [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)

2011-09-15

18

Nature of electric and magnetic dipoles gleaned from the Poynting theorem and the Lorentz force law of classical electrodynamics  

NASA Astrophysics Data System (ADS)

Starting with the most general form of Maxwell's macroscopic equations in which the free charge and free current densities, ?free and Jfree, as well as the densities of polarization and magnetization, P and M, are arbitrary functions of space and time, we compare and contrast two versions of the Poynting vector, namely, S = ?o- 1 E × B and S = E × H. Here E is the electric field, H is the magnetic field, B is the magnetic induction, and ?o is the permeability of free space. We argue that the identification of one or the other of these Poynting vectors with the rate of flow of electromagnetic energy is intimately tied to the nature of magnetic dipoles and the way in which these dipoles exchange energy with the electromagnetic field. In addition, the manifest nature of both electric and magnetic dipoles in their interactions with the electromagnetic field has consequences for the Lorentz law of force. If the conventional identification of magnetic dipoles with Amperian current loops is extended beyond Maxwell's macroscopic equations to the domain where energy, force, torque, momentum, and angular momentum are active participants, it will be shown that "hidden energy" and "hidden momentum" become inescapable consequences of such identification with Amperian current loops. Hidden energy and hidden momentum can be avoided, however, if we adopt S = E × H as the true Poynting vector, and also accept a generalized version of the Lorentz force law. We conclude that the identification of magnetic dipoles with Amperian current loops, while certainly acceptable within the confines of Maxwell's macroscopic equations, is inadequate and leads to complications when considering energy, force, torque, momentum, and angular momentum in electromagnetic systems that involve the interaction of fields and matter.

Mansuripur, Masud

2011-01-01

19

Lithium electric dipole polarizability  

SciTech Connect

The electric dipole polarizability of the lithium atom in the ground state is calculated including relativistic and quantum electrodynamics corrections. The obtained result {alpha}{sub E}=164.0740(5) a.u. is in good agreement with the less accurate experimental value of 164.19(1.08) a.u. The small uncertainty of about 3 parts per 10{sup 6} comes from the approximate treatment of quantum electrodynamics corrections. Our theoretical result can be considered as a benchmark for more general atomic structure methods and may serve as a reference value for the relative measurement of polarizabilities of the other alkali-metal atoms.

Puchalski, M.; KePdziera, D.; Pachucki, K. [Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, PL-60-780 Poznan (Poland); Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, PL-87-100 Torun (Poland); Faculty of Physics, University of Warsaw, Hoza 69, PL-00-681 Warsaw (Poland)

2011-11-15

20

Resonant electric dipole-dipole interactions between cold Rydberg atoms in a magnetic field K. Afrousheh, P. Bohlouli-Zanjani, J. D. Carter, A. Mugford, and J. D. D. Martin  

E-print Network

Resonant electric dipole-dipole interactions between cold Rydberg atoms in a magnetic field K October 2005; published 5 June 2006 Laser-cooled 85 Rb atoms were optically excited to 46d5/2 Rydberg states. A microwave pulse transferred a fraction of the atoms to the 47p3/2 Rydberg state. The resonant

Le Roy, Robert J.

21

How to Introduce the Magnetic Dipole Moment  

ERIC Educational Resources Information Center

We show how the concept of the magnetic dipole moment can be introduced in the same way as the concept of the electric dipole moment in introductory courses on electromagnetism. Considering a localized steady current distribution, we make a Taylor expansion directly in the Biot-Savart law to obtain, explicitly, the dominant contribution of the…

Bezerra, M.; Kort-Kamp, W. J. M.; Cougo-Pinto, M. V.; Farina, C.

2012-01-01

22

Dynamic stabilization of the magnetic field surrounding the neutron electric dipole moment spectrometer at the Paul Scherrer Institute  

NASA Astrophysics Data System (ADS)

The Surrounding Field Compensation (SFC) system described in this work is installed around the four-layer Mu-metal magnetic shield of the neutron electric dipole moment spectrometer located at the Paul Scherrer Institute. The SFC system reduces the DC component of the external magnetic field by a factor of about 20. Within a control volume of approximately 2.5 m × 2.5 m × 3 m, disturbances of the magnetic field are attenuated by factors of 5-50 at a bandwidth from 10 - 3 Hz up to 0.5 Hz, which corresponds to integration times longer than several hundreds of seconds and represent the important timescale for the neutron electric dipole moment measurement. These shielding factors apply to random environmental noise from arbitrary sources. This is achieved via a proportional-integral feedback stabilization system that includes a regularized pseudoinverse matrix of proportionality factors which correlates magnetic field changes at all sensor positions to current changes in the SFC coils.

Afach, S.; Bison, G.; Bodek, K.; Burri, F.; Chowdhuri, Z.; Daum, M.; Fertl, M.; Franke, B.; Grujic, Z.; Hélaine, V.; Henneck, R.; Kasprzak, M.; Kirch, K.; Koch, H.-C.; Kozela, A.; Krempel, J.; Lauss, B.; Lefort, T.; Lemière, Y.; Meier, M.; Naviliat-Cuncic, O.; Piegsa, F. M.; Pignol, G.; Plonka-Spehr, C.; Prashanth, P. N.; Quéméner, G.; Rebreyend, D.; Roccia, S.; Schmidt-Wellenburg, P.; Schnabel, A.; Severijns, N.; Voigt, J.; Weis, A.; Wyszynski, G.; Zejma, J.; Zenner, J.; Zsigmond, G.

2014-08-01

23

Electric dipole radiation near a mirror  

SciTech Connect

The emission of radiation by a linearly oscillating electric dipole is drastically altered when the dipole is close to the surface of a mirror. The energy is not emitted along optical rays, as for a free dipole, but as a set of four optical vortices. The field lines of energy flow spiral around a set of two lines through the dipole. At a larger distance from the dipole, singularities and isolated vortices appear. It is shown that these interference vortices are due to the vanishing of the magnetic field at their centers. In the plane of the mirror there is a singular circle with a diameter which is proportional to the distance between the dipole and the mirror. Inside this circle, all energy flows to a singularity on the mirror surface.

Li Xin; Arnoldus, Henk F. [Department of Physics and Astronomy, Mississippi State University, P. O. Drawer 5167, Mississippi State, Mississippi 39762-5167 (United States)

2010-05-15

24

Progress in metamaterials: Magnetic hybridization of electric dipole resonance and inhomogeneous structures for thin-film lenses  

NASA Astrophysics Data System (ADS)

From earlier theoretical work and practical implementation, understanding of negative index metamaterials (NIMs) has advanced rapidly. Much effort has been put into extending NIMs in the near-infrared (NIR) and in visible regions, where simple scaling of the magnetic response of the structures used for RF breaks down at the NIR. As a solution, a new structure in the form of a fishnet has emerged, and has been shown to successfully act as a new metamaterial in the infrared and visible regions. Attention in the research community is now turning to the direct applications. Here we report progress in the field of metamaterials for the magnetic hybridization of the electric dipole resonance and inhomogeneous metamaterial structures. From the fundamental and, possibly, application points of view, it is of interest to consider the coupling between the metamaterial magnetic resonance and electric dipole resonances of the absorbing species located in the metamaterial unit cell. Simple resonance coupling model and numerical rigorous coupled wave analysis (RCWA) were used to investigate the effect of adding a dielectric with a dipole absorption peak to a fishnet metamaterial. Anti-crossing behavior and an exchange of oscillator strength as the metamaterial structural resonance is tuned through the absorption resonance were obtained. Response of the NIM structure with a dielectric material without an absorber shows only a single resonant peak, resulting from the coupling of the broadband negative epsilon with the structurally resonant negative micro associated with the LC circuit between the two metal plates. With the addition of a dipole absorber in the dielectric, the NIM exhibits doubly resonant behavior. Presence of an electric dipole resonance in the dielectric of the fishnet structure manifests itself in a modification of the magnetic permeability, which in turn modifies the negative index behavior. A set of experimental samples were fabricated using standard lithographic processing. An Al-BCB-Al fishnet structure was used. Transmission data was obtained by FTIR. Plotting positions of the resonance peaks in the transmission response against o0 clearly shows coupling between the resonances with hybridization behavior First step in development of possible application for the metamaterials was done by Driscoll in 2006. He demonstrated a free space focusing by means of Split Ring Resonator structure. We take the next step and demonstrate that fishnet inhomogeneous metamaterial structures can be used for the thin-film lenses in the NIR regime. Here we report the first numerical demonstration of a flat, thin-film (<250 nm) GRIN positive lens operating in the NIR (˜1.55 microm) and based on the fishnet structure. This represents a significant advance toward applications as well as steps forward in design complexity and construction technique. Complex RCWA based, parametric studies and the optimization for the largest achievable phase shift with smallest variation in transmission have been performed. Proposed (64x64)lambda2 area experimental samples will have small edge effects and act as f/26 lens. The F number can be significantly improved by stacking several layers of NIMs. Preliminary experimental results show a successful pattern transferring in the photoresist layer by the use of Imaging Interferometric Lithography (IIL) tool.

Smolev, Svyatoslav

25

About a peculiar extra U(1): Z{sup '} discovery limit, muon anomalous magnetic moment, and electron electric dipole moment  

SciTech Connect

The model (Lagrangian) with a peculiar extra U(1)[S. M. Barr and I. Dorsner, Phys. Rev. D 72, 015011 (2005); S. M. Barr and A. Khan, Phys. Rev. D 74, 085023 (2006)] is clearly presented. The assigned extra U(1) gauge charges give a strong constraint to build Lagrangians. The Z{sup '} discovery limits are estimated and predicted at the Tevatron and the LHC. The new contributions of the muon anomalous magnetic moment are investigated at one and two loops, and we predict that the deviation from the standard model may be explained. The electron electric dipole moment could also be generated because of the explicit CP-violation effect in the Higgs sector, and a sizable contribution is expected for a moderately sized CP phase [argument of the CP-odd Higgs], 0.1{<=}sin{delta}{<=}1[6 deg. {<=}arg(A){<=}90 deg.].

Heo, Jae Ho [Physics Department, University of Illinois at Chicago, Chicago, Illinois 60607 (United States)

2009-08-01

26

Dynamic stabilization of the magnetic field surrounding the neutron electric dipole moment spectrometer at the Paul Scherrer Institute  

E-print Network

The Surrounding Field Compensation (SFC) system described in this work is installed around the four-layer Mu-metal magnetic shield of the neutron electric dipole moment spectrometer located at the Paul Scherrer Institute. The SFC system reduces the DC component of the external magnetic field by a factor of about 20. Within a control volume of approximately 2.5m x 2.5m x 3m disturbances of the magnetic field are attenuated by factors of 5 to 50 at a bandwidth from $10^{-3}$ Hz up to 0.5 Hz, which corresponds to integration times longer than several hundreds of seconds and represent the important timescale for the nEDM measurement. These shielding factors apply to random environmental noise from arbitrary sources. This is achieved via a proportional-integral feedback stabilization system that includes a regularized pseudoinverse matrix of proportionality factors which correlates magnetic field changes at all sensor positions to current changes in the SFC coils.

S. Afach; G. Bison; K. Bodek; F. Burri; Z. Chowdhuri; M. Daum; M. Fertl; B. Franke; Z. Grujic; V. Helaine; R. Henneck; M. Kasprzak; K. Kirch; H. -C. Koch; A. Kozela; J. Krempel; B. Lauss; T. Lefort; Y. Lemiere; M. Meier; O. Naviliat-Cuncic; F. M. Piegsa; G. Pignol; C. Plonka-Spehr; P. N. Prashanth; G. Quemener; D. Rebreyend; S. Roccia; P. Schmidt-Wellenburg; A. Schnabel; N. Severijns; J. Voigt; A. Weis; G. Wyszynski; J. Zejma; J. Zenner; G. Zsigmond

2014-08-28

27

Multiferroicity in an organic charge-transfer salt that is suggestive of electric-dipole-driven magnetism.  

PubMed

Multiferroics, showing simultaneous ordering of electrical and magnetic degrees of freedom, are remarkable materials as seen from both the academic and technological points of view. A prominent mechanism of multiferroicity is the spin-driven ferroelectricity, often found in frustrated antiferromagnets with helical spin order. There, as for conventional ferroelectrics, the electrical dipoles arise from an off-centre displacement of ions. However, recently a different mechanism, namely purely electronic ferroelectricity, where charge order breaks inversion symmetry, has attracted considerable interest. Here we provide evidence for ferroelectricity, accompanied by antiferromagnetic spin order, in a two-dimensional organic charge-transfer salt, thus representing a new class of multiferroics. We propose a charge-order-driven mechanism leading to electronic ferroelectricity in this material. Quite unexpectedly for electronic ferroelectrics, dipolar and spin order arise nearly simultaneously. This can be ascribed to the loss of spin frustration induced by the ferroelectric ordering. Hence, here the spin order is driven by the ferroelectricity, in marked contrast to the spin-driven ferroelectricity in helical magnets. PMID:22886065

Lunkenheimer, Peter; Müller, Jens; Krohns, Stephan; Schrettle, Florian; Loidl, Alois; Hartmann, Benedikt; Rommel, Robert; de Souza, Mariano; Hotta, Chisa; Schlueter, John A; Lang, Michael

2012-09-01

28

Multiferroicity in an organic charge-transfer salt that is suggestive of electric-dipole-driven magnetism  

SciTech Connect

Multiferroics, showing simultaneous ordering of electrical and magnetic degrees of freedom, are remarkable materials as seen from both the academic and technological points of view. A prominent mechanism of multiferroicity is the spin-driven ferroelectricity, often found in frustrated antiferromagnets with helical spin order. There, as for conventional ferroelectrics, the electrical dipoles arise from an off-centre displacement of ions. However, recently a different mechanism, namely purely electronic ferroelectricity, where charge order breaks inversion symmetry, has attracted considerable interest. Here we provide evidence for ferroelectricity, accompanied by antiferromagnetic spin order, in a two-dimensional organic charge-transfer salt, thus representing a new class of multiferroics. We propose a charge-order-driven mechanism leading to electronic ferroelectricity in this material. Quite unexpectedly for electronic ferroelectrics, dipolar and spin order arise nearly simultaneously. This can be ascribed to the loss of spin frustration induced by the ferroelectric ordering. Hence, here the spin order is driven by the ferroelectricity, in marked contrast to the spin-driven ferroelectricity in helical magnets.

Lunkenheimer, P.; Muller, J.; Krohns, S.; Schrettle, F.; Loidl, A.; Hartmann, B.; Rommel, R.; de Souza, M.; Hotta, C.; Schlueter, J. A.; Lang, M. (Materials Science Division); (Univ. Augsburg); (Goethe-Univ. Frankfurt); (Kyoto Sangyo Univ.)

2012-01-01

29

Equivalent source magnetic dipoles revisited  

NASA Astrophysics Data System (ADS)

Equivalent point source inversion in the rectangular coordinate system has been widely used to reduce satellite magnetic data collected at different altitudes to a common elevation over small areas. This method is based on the expression of the magnetic anomaly caused by a magnetic dipole. Such an expression derived in a spherical coordinate system by von Frese et al. [1981] is found erroneous. We point out the errors in von Frese et al.'s [1981] formulas and present the correct expression for the magnetic field of a magnetic dipole in a spherical coordinate system.

Dyment, J.; Arkani-Hamed, J.

30

Characterisation of superconducting capillaries for magnetic shielding of twisted-wire pairs in a neutron electric dipole moment experiment  

NASA Astrophysics Data System (ADS)

The cryoEDM neutron electric dipole moment experiment requires a SQUID magnetometry system with pick-up loops inside a magnetically shielded volume connected to SQUID sensors by long (up to 2 m) twisted-wire pairs (TWPs). These wires run outside the main shield, and therefore must run through superconducting capillaries to screen unwanted magnetic pick-up. We show that the average measured transverse magnetic pick-up of a set of lengths of TWPs is equivalent to a loop area of 5.0×10-6 m2/m, or 14 twists per metre. From this we set the requirement that the magnetic shielding factor of the superconducting capillaries used in the cryoEDM system must be greater than 8.0×104. The shielding factor-the ratio of the signal picked-up by an unshielded TWP to that induced in a shielded TWP-was measured for a selection of superconducting capillaries made from solder wire. We conclude the transverse shielding factor of a uniform capillary is greater than 107. The measured pick-up was equal to, or less than that due to direct coupling to the SQUID sensor (measured without any TWP attached). We show that discontinuities in the capillaries substantially impair the magnetic shielding, yet if suitably repaired, this can be restored to the shielding factor of an unbroken capillary. We have constructed shielding assemblies for cryoEDM made from lengths of single core and triple core solder capillaries, joined by a shielded Pb cylinder, incorporating a heater to heat the wires above the superconducting transition as required.

Henry, S.; Pipe, M.; Cottle, A.; Clarke, C.; Divakar, U.; Lynch, A.

2014-11-01

31

Dipole relaxation in an electric field  

NASA Astrophysics Data System (ADS)

From Boltzmann's equation, S=k ln?, an expression for the orientational entropy, S of a rigid rod (electric dipole) is derived. The free energy of the dipole in an electric field is then calculated as a function of both the dipole's average orientation and the field strength. Application of the equilibrium criterion to the free energy yields the field dependence of the entropy of the dipole. Irreversible thermodynamics is used to derive the general form of the equation of motion of the dipole's average orientation. Subsequent application of Newton's second law of motion produces Debye's classical expression for the relaxation of an electric dipole in a viscous medium.

Neumann, Richard M.

1980-07-01

32

Complete Electric and Magnetic Dipole Response of 208Pb from Zero-Degree Inelastic Proton Scattering  

NASA Astrophysics Data System (ADS)

Small-angle polarized proton scattering including 0° off 208Pb has been studied at the RCNP cyclotron with high energy resolution of the order of 25 keV (FWHM). The complete E1 strength distribution from 5 to 20 MeV could be extracted from the data and is found to agree well with available data. New E1 strength is found in the energy region above threshold inacessible in previous experiments. The total E1 polarizability as well as the properties of the pygmy dipole resonance could be determined with high precision providing important experimental constraints on the neutron skin thickness in 208Pb and the symmetry energy of neutron-rich matter. Additionally, information on the spin-M1 strength in 208Pb was obtained. Assuming dominance of the central spin-isospinflip part of the effective proton-nucleus interaction, the B(M1) transition strength can be derived. It corresponds well with data from electromagnetic probes indicating that the reaction can provide information on the poorly known spin-M1 resonance in heavy nuclei.

von Neumann-Cosel, P.

2015-11-01

33

Electric Dipole Transitions at Magnetoacoustic Resonance  

NASA Astrophysics Data System (ADS)

Ferromagnetic-ferroelectric composites show giant magnetoelectric (ME) effects that are facilitated by the sample response to electric, magnetic, and elastic forces. Composites consisting of magnetostrictive ferrites and piezoelectric lead zirconate titanate (PZT) or lead magnesium niobate-lead titanate (PMN-PT) are found to show strong ME coupling. Such materials also provide us with unique opportunities for theoretical and experimental studies on ME coupling when the magnetic and/or electric subsystems show resonance behavior. Two types of resonances are of importance: electromechanical resonance (EMR) for the piezoelectric component and ferromagnetic resonance (FMR) for the magnetic component. At the coincidence of EMR and FMR, i.e., at the magneto-acoustic resonance (MAR) ME interaction becomes stronger [1]. This work focuses on electric dipole transitions in multilayer ferromagnetic-ferroelectric composites, such as yttrium iron garnet (YIG) and PZT, at MAR. Expressions have been obtained for ME susceptibility and the ME coefficient. The results indicate the potential for novel microwave devices based on ME interactions at MAR. Supported by grants from the ARO, ONR and NSF.[1] M.I. Bichurin, V.M. Petrov, O.V. Ryabkov, S.V. Averkin and G. Srinivasan, Phys. Rev. B. 72, 060408(R) (2005).

Bichurin, M. I.; Petrov, V. M.; Ryabkov, O. V.; Filippov, A. V.; Ivanov, A. A.; Srinivasan, G.

2006-03-01

34

Magnetic dipole discharges. III. Instabilities  

SciTech Connect

Instabilities in a cross-field discharge around a permanent magnet have been investigated. The permanent magnet serves as a cold cathode and the chamber wall as an anode. The magnet is biased strongly negative and emits secondary electrons due to impact of energetic ions. The electrons outside the sheath are confined by the strong dipolar magnetic field and by the ion-rich sheath surrounding the magnet. The electron energy peaks in the equatorial plane where most ionization occurs and the ions are trapped in a negative potential well. The discharge mechanism is the same as that of cylindrical and planar magnetrons, but here extended to a 3-D cathode geometry using a single dipole magnet. While the basic properties of the discharge are presented in a companion paper, the present focus is on various observed instabilities. The first is an ion sheath instability which oscillates the plasma potential outside the sheath below the ion plasma frequency. It arises in ion-rich sheaths with low electron supply, which is the case for low secondary emission yields. Sheath oscillations modulate the discharge current creating oscillating magnetic fields. The second instability is current-driven ion sound turbulence due to counter-streaming electrons and ions. The fluctuations have a broad spectrum and short correlation lengths in all directions. The third type of fluctuations is spiky potential and current oscillations in high density discharges. These appear to be due to unstable emission properties of the magnetron cathode.

Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California Los Angeles, California 90095-1547 (United States)] [Department of Physics and Astronomy, University of California Los Angeles, California 90095-1547 (United States); Ionita, C.; Schrittwieser, R. [Institute for Ion Physics and Applied Physics, University of Innsbruck A-6020 Innsbruck (Austria)] [Institute for Ion Physics and Applied Physics, University of Innsbruck A-6020 Innsbruck (Austria)

2013-08-15

35

Electric Dipole Moment of a BPS Monopole  

E-print Network

Monopole ``superpartner'' solutions are constructed by acting with finite, broken supersymmetry transformations on a bosonic N=2 BPS monopole. The terms beyond first order in this construction represent the backreaction of the the fermionic zero-mode state on the other fields. Because of the quantum nature of the fermionic zero-modes, the superpartner solution is necessarily operator valued. We extract the electric dipole moment operator and show that it is proportional to the fermion zero-mode angular momentum operator with a gyroelectric ratio g=2. The magnetic quadrupole operator is shown to vanish identically on all states. We comment on the usefulness of the monopole superpartner solution for a study of the long-range spin dependent dynamics of BPS monopoles.

David Kastor; Euy Soo Na

1999-01-04

36

Exactly calculable field components of electric dipoles in planar boundary  

NASA Astrophysics Data System (ADS)

The Sommerfeld integrals for the electromagnetic fields in the planar boundary between air and a homogeneous, isotropic medium, due to a horizontal and a vertical electric dipole each lying along the interface, are examined in detail. In the case of the horizontal dipole, the tangential electric field is given in terms of series that involve confluent hypergeometric functions, namely, the Fresnel and exponential integrals. A similar exposition is presented for the magnetic and vertical electric fields of the vertical dipole. When the index of refraction of the adjacent space is of a sufficiently large magnitude, the derived series converge rapidly and uniformly with the distance from the source. Specifically, their rates of convergence are shown to be independent of distance. It is pointed out that the corresponding formulas of King et al. are valid down to any distance close to the source, where they smoothly connect to known "quasi-static" approximations.

Margetis, Dionisios; Wu, Tai Tsun

2001-02-01

37

Magnetic dipole imaging by a scanning magnetic microscope  

NASA Astrophysics Data System (ADS)

A reconstruction technique to evaluate residual magnetic fields and simulate magnetic images due to dipole distribution in ferromagnetic samples has been proposed in connection with a scanning magnetic microscope based on a high-Tc superconducting quantum interference device (SQUID). We have extended the expression of a point magnetic dipole to represent spatially extended sources and the generated magnetic field has been compared with experiments. In particular, a recently installed scanning SQUID magnetic microscope (model 770 by Tristan Technology) has been used. Magnetic maps obtained at different sample-to-sensor distances and in several configurations have been compared with simulations. With this aim, ferromagnetic rod samples have been modeled as extended magnetic dipoles close to the sensor. Excellent agreement has been obtained, confirming the efficiency of the proposed technique. Such an imaging technique has been demonstrated to be an easy-to-handle tool to identify dipole configurations producing a specific magnetic image.

Adamo, M.; Nappi, C.; Sarnelli, E.

2008-01-01

38

Permanent Electric Dipole Moment of Cerium Monoxide  

NASA Astrophysics Data System (ADS)

Stark spectra of the [16.5]2-X12 and [16.5]2-X23 transitions of cerium monoxide (CeO) have been obtained at a resolution of ˜50 MHz. Analysis of the Stark spectra yielded permanent electric dipole moments, ?el, of 3.119(8), 3.115(7), and 2.119(8) D for the X12, X23, and [16.5]2 states, respectively. The ground X12 state dipole moment is shown to follow the trend shown by other lanthanide oxides. While most ab initio calculations tend to overestimate the ground state dipole moment, the value calculated by using pseudopotentials in which the 4f orbital participates in the chemical bonding (Dolg,M.; Stoll, H.; Preuss, H. THEOCHEM 1991, 231, 243] is in very good agreement with our experimental value.

Linton, Colan; Chen, Jinhai; Steimle, Timothy C.

2009-04-01

39

Offset magnetic dipoles in white dwarfs  

SciTech Connect

Various authors have reported observations of the flux and circular polarization for the four stars KPD 0253 + 5052, PG 1658 + 441, PG 1533 - 057 and K 813 - 14. On the basis of the observational data, the stars were classified as magnetic white dwarfs. To place constraints on the magnetic field strengths and geometries of these stars, the relevant authors qualitatively compared the data with available theory and, in two cases, used a model of optically thin hydrogen threaded by a magnetic field. In this paper, a more detailed model for magnetic white dwarfs is used to assess the results previously obtained for these four stars. For one star (KPD 0253 + 5052), clear evidence is found for deviation from a centered dipole field structure. The observational data for the other stars are not uniquely explained by centered dipole models. The observations can be interpreted, however, through the additional use of dipole field geometries offset from the stellar center. 15 refs.

Achilleos, N.; Wickramasinghe, D.T. (Mount Stromlo and Siding Spring Observatories, Canberra (Australia) Australian National Univ., Canberra (Australia))

1989-11-01

40

Offset magnetic dipoles in white dwarfs  

NASA Astrophysics Data System (ADS)

Various authors have reported observations of the flux and circular polarization for the four stars KPD 0253 + 5052, PG 1658 + 441, PG 1533 - 057 and K 813 - 14. On the basis of the observational data, the stars were classified as magnetic white dwarfs. To place constraints on the magnetic field strengths and geometries of these stars, the relevant authors qualitatively compared the data with available theory and, in two cases, used a model of optically thin hydrogen threaded by a magnetic field. In this paper, a more detailed model for magnetic white dwarfs is used to assess the results previously obtained for these four stars. For one star (KPD 0253 + 5052), clear evidence is found for deviation from a centered dipole field structure. The observational data for the other stars are not uniquely explained by centered dipole models. The observations can be interpreted, however, through the additional use of dipole field geometries offset from the stellar center.

Achilleos, N.; Wickramasinghe, D. T.

1989-11-01

41

Incipient magnetic rotation? A magnetic dipole band in 104Cd  

E-print Network

High spin states of the nucleus 104Cd have been studied using the Gammapshere array. The level scheme for 104Cd has been revised and evidence for a structure consisting of magnetic dipole transitions is presented. Shell model calculations, published previously, are invoked to support an interpretation of this structure as an incpient case of magnetic rotation where the transversal magnetic dipole moment is not strong enough to break the signature symmetry.

D. G. Jenkins; R. Wadsworth; J. A. Cameron; M. P. Carpenter; C. J. Chiara; R. M. Clark M. Devlin; P. Fallon; D. B. Fossan; I. M. Hibbert; R. V. F. Janssens; V. P. Janzen; R. Kruecken; D. R. LaFosse; G. J. Lane; T. Lauritsen; I. Y. Lee; A. O. Macchiavelli; C. M. Parry; D. G. Sarsantities; J. M. Sears; D. Seweryniak; J. F. Smith; K. Starosta; D. Ward; I. Wiedenhoever; A. N. Wilson; J. N. Wilson; S. Frauendorf

2000-07-05

42

Circular current loops, magnetic dipoles and spherical harmonic analysis.  

USGS Publications Warehouse

Spherical harmonic analysis (SHA) is the most used method of describing the Earth's magnetic field, even though spherical harmonic coefficients (SHC) almost completely defy interpretation in terms of real sources. Some moderately successful efforts have been made to represent the field in terms of dipoles placed in the core in an effort to have the model come closer to representing real sources. Dipole sources are only a first approximation to the real sources which are thought to be a very complicated network of electrical currents in the core of the Earth. -Author

Alldredge, L.R.

1980-01-01

43

Relativistic unitary coupled-cluster study of the electric quadrupole moment and magnetic dipole hyperfine constants of {sup 199}Hg{sup +}  

SciTech Connect

Searching for an accurate optical clock which can serve as a better time standard than the present-day atomic clock is highly demanding from several areas of science and technology. Several attempts have been made to build more accurate clocks with different ion species. In this paper, we discuss the electric quadrupole and hyperfine shifts in the 5d{sup 9}6s{sup 2} {sup 2}D{sub 5/2}(F=0,m{sub F}=0){r_reversible}5d{sup 10}6s {sup 2}S{sub 1/2}(F=2,m{sub F}=0) clock transition in {sup 199}Hg{sup +}, one of the most promising candidates for next-generation optical clocks. We have applied Fock-space unitary coupled-cluster theory to study the electric quadrupole moment of the 5d{sup 9}6s{sup 2} {sup 2}D{sub 5/2} state and magnetic dipole hyperfine constants of 5d{sup 9}6s{sup 2} {sup 2}D{sub 3/2,5/2} and 5d{sup 10}6s{sup 1} {sup 2}S{sub 1/2} states, respectively, of {sup 199}Hg{sup +}. We have also compared our results with available data. To the best of our knowledge, this is the first time a variant of coupled-cluster theories has been applied to study these kinds of properties of Hg{sup +} and is the most accurate estimate of these quantities to date.

Sur, Chiranjib; Chaudhuri, Rajat K. [Department of Astronomy, Ohio State University, Columbus, Ohio 43210 (United States); Indian Institute of Astrophysics, Koramangala, Block II, Bangalore 560 034 (India)

2007-09-15

44

The Case of the Disappearing Magnetic Dipole  

ERIC Educational Resources Information Center

The problem of an oscillating magnetic dipole at the centre of a lossless dielectric spherical shell is considered. For simplicity, the free-space wavelength is taken to be much greater than the shell radii, but the relative permittivity [epsilon][subscript r] of the shell is taken as much greater than unity, so the wavelength in the shell could…

Gough, W.

2008-01-01

45

Magnetic dipole strength in 128Xe and 134Xe in the spin-flip resonance region  

NASA Astrophysics Data System (ADS)

The magnetic dipole strength in the energy region of the spin-flip resonance is investigated in 128Xe and 134Xe using quasimonoenergetic and linearly polarized ? -ray beams at the High-Intensity ? -Ray Source facility in Durham, North Carolina, USA. Absorption cross sections were deduced for the magnetic and electric and dipole strength distributions separately for various intervals of excitation energy, including the strength of states in the unresolved quasicontinuum. The magnetic dipole strength distributions show structures resembling a resonance in the spin-flip region around an excitation energy of 8 MeV. The electric dipole strength distributions obtained from the present experiments are in agreement with the ones deduced from an earlier experiment using broad-band bremsstrahlung instead of a quasimonoenergetic beam. The experimental magnetic and electric dipole strength distributions are compared with phenomenological approximations and with predictions of a quasiparticle random phase approximation in a deformed basis.

Massarczyk, R.; Rusev, G.; Schwengner, R.; Dönau, F.; Bhatia, C.; Gooden, M. Â. E.; Kelley, J. Â. H.; Tonchev, A. Â. P.; Tornow, W.

2014-11-01

46

Revised cross section for RHIC dipole magnets  

SciTech Connect

Using the experience gained in designing and building Relativistic Heavy Ion Collider (RHIC) dipole prototype magnets an improved cross section has been developed. Significant features of this design include the use of only three wedges for field shaping and wedge cross sections which are sectors of an annulus. To aid in the understanding of the actual magnets, one has been sectioned, and detailed mechanical and photographic measurements made of the wire positions. The comparison of these measurements with the magnetic field measurements will is presented. 2 refs, 3 figs., 2 tabs.

Thompson, P.A.; Gupta, R.C.; Kahn, S.A.; Hahn, H.; Morgan, G.H.; Wanderer, P.J.; Willen, E.

1991-01-01

47

Detuned electrical dipoles for plasmonic sensing.  

PubMed

We demonstrate that a pair of electrical dipolar scatterers resonating at different frequencies, i.e., detuned electrical dipoles, can be advantageously employed for plasmonic sensing of the environment, both as an individual subwavelength-sized sensor and as a unit cell of a periodic array. It is shown that the usage of the ratio between the powers of light scattered into opposite directions (or into different diffraction orders), which peaks at the intermediate frequency, allows one to reach a sensitivity of ? 400 nm/RIU with record high levels of figure of merit exceeding 200. Qualitative considerations are supported with detailed simulations and proof-of-principle experiments using lithographically fabricated gold nanorods with resonances at 800 nm. PMID:20879722

Evlyukhin, Andrey B; Bozhevolnyi, Sergey I; Pors, Anders; Nielsen, Michael G; Radko, Ilya P; Willatzen, Morten; Albrektsen, Ole

2010-11-10

48

Development of a simulation for measuring neutron electric dipole moment  

NASA Astrophysics Data System (ADS)

The neutron electric dipole moment (nEDM) is sensitive to new physics beyond the standard model and could prove to be a new source of CP violation. Several experiments are being planned worldwide for its high-precision measurement. The nEDM is measured as the ultracold neutron (UCN) spin precession in a storage bottle under homogeneous electric and magnetic fields. In nEDM measurement, the systematic uncertainties are due to the motion of the UCNs, the geometry of the measurement system, and inhomogeneous electric and magnetic fields. Therefore, it is essential to quantitatively understand these effects in order to reduce them. Geant4UCN is an ideal simulation framework because it can compute the UCN trajectory, evaluate the time evolution of the spin precession due to arbitrary electric and magnetic fields, and define the storage geometry flexibly. We checked how accurately Geant4UCN can calculate the spin precession. We found that because of rounding errors, it cannot simulate it accurately enough for nEDM experiments, assuming homogeneous electric and magnetic fields with strengths of 10 kV/cm and 1 ?T, respectively, and 100 s of storage. In this paper, we report on its discrepancies and describe a solution.

Katayama, Ryo; Mishima, Kenji; Yamashita, Satoru; Sakurai, Dai; Kitaguchi, Masaaki; Yoshioka, Tamaki; Seki, Yoshichika

2014-07-01

49

An electrically charged doubly spinning dipole black ring  

E-print Network

We present a new asymptotically flat, doubly spinning black ring of D = 5 Einstein-Maxwell-dilaton theory with Kaluza-Klein dilaton coupling. Besides the mass and two angular momenta, the solution displays both electric charge and (magnetic) dipole charge. The class of solutions that are free from conical singularities is described by four parameters. We first derive the solution in six dimensions employing the inverse scattering method, thereby generalising the inverse-scattering construction by two of the current authors of Emparan's singly spinning dipole black ring. The novel black ring itself arises upon circle Kaluza-Klein reduction. We also compute the main physical properties and asymptotic charges of our new class of solutions. Finally, we present a five-parameter generalisation of our solution.

Jorge V. Rocha; Maria J. Rodriguez; Oscar Varela

2012-12-21

50

Dipole-sheet multipole magnets for accelerators  

SciTech Connect

The dipole-sheet formalism can be used to describe both cylindrical current-sheet multipole magnets and cylindrical-bore magnets made up of permanent magnet blocks. For current sheets, the formalism provides a natural way of finding a finite set of turns that approximate a continuous distribution. The formalism is especially useful In accelerator applications where large-bore, short, high-field-quality magnets that are dominated by fringe fields are needed. A further advantage of the approach is that in systems with either open or cylindrically symmetric magnetic boundaries, analytical expressions for the three-dimensional fields that are suitable for rapid numerical evaluation can be derived. This development is described in some detail. Also, recent developments in higher-order particle-beam optics codes based on the formalism are described briefly.

Walstrom, P.L.

1993-10-01

51

Magnetic field decay in model SSC dipoles  

SciTech Connect

We have observed that some of our model SSC dipoles have long time constant decays of the magnetic field harmonics with amplitudes large enough to result in significant beam loss, if they are not corrected. The magnets were run at constant current at the SSC injection field level of 0.3 tesla for one to three hours and changes in the magnetic field were observed. One explanation for the observed field decay is time dependent superconductor magnetization. Another explanation involves flux creep or flux flow. Data are presented on how the decay changes with previous flux history. Similar magnets with different Nb-Ti filament spacings and matrix materials have different long time field decay. A theoretical model using proximity coupling and flux creep for the observed field decay is discussed. 10 refs., 5 figs., 2 tabs.

Gilbert, W.S.; Althaus, R.F.; Barale, P.J.; Benjegerdes, R.W.; Green, M.A.; Green, M.I.; Scanlan, R.M.

1988-08-01

52

Generalized dyons and magnetic dipoles: the issue of angular momentum  

E-print Network

It is known that a non-Abelian magnetic monopole cannot rotate globally (although it may possess a nonzero angular momentum density). At the same time, the total angular momentum of a magnetic dipole equals the electric charge. In this work we question the generality of these results by considering a number of generalizations of the Georgi-Glashow model. We study two different types of finite energy, regular configurations: solutions with net magnetic charge and monopole-antimonopole pairs with zero net magnetic charge. These configurations are endowed with an electric charge and carry also a nonvanishing angular momentum density. However, we argue that the qualitative results found in the Georgi-Glashow model are generic and thus a magnetic monopole cannot spin as long as the matter fields feature the usual "monopole" asymptotic behaviour independently of the dynamics of the model. A study of the properties of the dyons and magnetic dipoles in some generalizations of the Georgi-Glashow model supplemented with higher order Skyrme-like terms in the gauge curvature and Higgs fields is given quantitatively.

Francisco Navarro-Lerida; Eugen Radu; D. H. Tchrakian

2014-07-12

53

Generalized dyons and magnetic dipoles: The issue of angular momentum  

NASA Astrophysics Data System (ADS)

It is known that a non-Abelian magnetic monopole cannot rotate globally (although it may possess a nonzero angular momentum density). At the same time, the total angular momentum of a magnetic dipole equals the electric charge. In this work we question the generality of these results by considering a number of generalizations of the Georgi-Glashow model. We study two different types of finite energy, regular configurations: solutions with net magnetic charge and monopole-antimonopole pairs with zero net magnetic charge. These configurations are endowed with an electric charge and carry also a nonvanishing angular momentum density. However, we argue that the qualitative results found in the Georgi-Glashow model are generic and thus a magnetic monopole cannot spin as long as the matter fields feature the usual "monopole" asymptotic behavior independently of the dynamics of the model. A study of the properties of the dyons and magnetic dipoles in some generalizations of the Georgi-Glashow model supplemented with higher order Skyrme-like terms in the gauge curvature and Higgs fields is given quantitatively.

Navarro-Lérida, Francisco; Radu, Eugen; Tchrakian, D. H.

2014-09-01

54

A search for the electric dipole of the electron  

SciTech Connect

We report a new upper limit on the electric dipole moment (EDM) of the electron of d{sub e} = 0.1 {plus minus} 3.2 {times} 10{sup {minus}26} e-cm. This precision is one hundred times better than any previously published limit and a factor of two better than that of unofficial reports. Recently there has been a great deal of theoretical interest in the possibility of a non-zero electron EDM. Models such as the left-right-symmetric Standard Model and an off-standard'' model with new heavy neutrinos are constrained by the new limit on d{sub e}. A non-zero electron EDM would violate the time reversal and parity space-time symmetries. T-violation was observed in neutral kaon decay and is still not fully explained by the Standard Model. Our experimental technique involves searching for an energy shift, linear in applied electric field, between the m{sub F} = 1 and m{sub F} = {minus}1 magnetic sublevels of the F=1 hyperfine level of the 6{sup 2}P{sub 1/2} ground state of atomic thallium. If the electron has a non-zero EDM, this thallium state will exhibit an atomic electric dipole moment that is roughly 600 times larger. The energy shift is detected with the technique of magnetic resonance spectroscopy, employing separated oscillating fields, applied to an atomic beam of thallium. In the approach, any relative phase-shift between the m{sub F} = {plus minus}1 components of the F=1 wavefunction acquired by the atom as it travels through an electric field is detected through interference with two separate oscillating magnetic fields located on either side of the electric field. The new level of precision is achieved through several improvements on previous experiments including employment of a vertical apparatus, two opposing atomic beams, and optical pumping for atomic state selection and analysis.

Abdullah, K.F.

1989-08-01

55

PULSAR PAIR CASCADES IN A DISTORTED MAGNETIC DIPOLE FIELD  

SciTech Connect

We investigate the effect of a distorted neutron star dipole magnetic field on pulsar pair cascade multiplicity and pair death lines. Using a simple model for a distorted dipole field that produces an offset polar cap (PC), we derive the accelerating electric field above the PC in space-charge-limited flow. We find that even a modest azimuthally asymmetric distortion can significantly increase the accelerating electric field on one side of the PC and, combined with a smaller field line radius of curvature, leads to larger pair multiplicity. The death line for producing pairs by curvature radiation moves downward in the P- P-dot diagram, allowing high pair multiplicities in a larger percentage of the radio pulsar population. These results could have important implications for the radio pulsar population, high energy pulsed emission, and the pulsar contribution to cosmic ray positrons.

Harding, Alice K.; Muslimov, Alex G. [Astrophysics Science Division, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2011-01-01

56

Search for the Neutron Electric Dipole Moment  

SciTech Connect

Searches for the neutron electric dipole moment (EDM) are motivated by their highly suppressed Standard Model value. The observation of a non-zero signal in the next generation of experiments would point unambiguously to the existence of new physics beyond the Standard Model. Several ongoing efforts worldwide hold the potential for an up to two-orders-of-magnitude improvement beyond the current upper limit on the neutron EDM of 2.9x10{sup -6} e-cm. In this talk, I review the basic measurement principles of neutron EDM searches, then discuss a new experiment to be carried out in the United States at the Spallation Neutron Source with ultracold neutrons and an in-situ '3He''co-magnetometer'.

Plaster, Brad [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States)

2010-08-04

57

Electric dipole moment of the electron and of the neutron  

NASA Technical Reports Server (NTRS)

It is shown that if Higgs-boson exchange mediates CP violation a significant electric dipole moment for the electron can result. Analogous effects can contribute to the neutron's electric dipole moment at a level competitive with Weinberg's three-gluon operator.

Barr, S. M.; Zee, A.

1990-01-01

58

New measurements of the neutron electric dipole moment  

NASA Astrophysics Data System (ADS)

We report a new measurement of the neutron electric dipole moment with the PNPI EDM spectrometer using the ultracold neutron source PF2 at the research reactor of the ILL. Its first results can be interpreted as a limit on the neutron electric dipole moment of | d n | < 5.5 × 10-26 e cm (90% confidence level).

Serebrov, A. P.; Kolomenskiy, E. A.; Pirozhkov, A. N.; Krasnoschekova, I. A.; Vassiljev, A. V.; Polushkin, A. O.; Lasakov, M. S.; Fomin, A. K.; Shoka, I. V.; Solovey, V. A.; Zherebtsov, O. M.; Geltenbort, P.; Ivanov, S. N.; Zimmer, O.; Alexandrov, E. B.; Dmitriev, S. P.; Dovator, N. A.

2014-03-01

59

Communication: Permanent dipoles contribute to electric polarization in chiral NMR spectra  

SciTech Connect

Nuclear magnetic resonance spectroscopy is blind to chirality because the spectra of a molecule and its mirror image are identical unless the environment is chiral. However, precessing nuclear magnetic moments in chiral molecules in a strong magnetic field induce an electric polarization through the nuclear magnetic shielding polarizability. This effect is equal and opposite for a molecule and its mirror image but is small and has not yet been observed. It is shown that the permanent electric dipole moment of a chiral molecule is partially oriented through the antisymmetric part of the nuclear magnetic shielding tensor, causing the electric dipole to precess with the nuclear magnetic moment and producing a much larger temperature-dependent electric polarization with better prospects of detection.

Buckingham, A. David, E-mail: adb1000@cam.ac.uk [Department of Chemistry, Cambridge University, Cambridge CB2 1EW (United Kingdom)

2014-01-07

60

Spherical Bondi accretion onto a magnetic dipole  

E-print Network

Quasi-spherical supersonic (Bondi-type) accretion to a star with a dipole magnetic field is investigated using resistive magnetohydrodynamic simulations. A systematic study is made of accretion to a non-rotating star, while sample results for a rotating star are also presented. A new stationary subsonic accretion flow is found with a steady rate of accretion to the magnetized star smaller than the Bondi accretion rate. Dependences of the accretion rate and the flow pattern on the magnetic momentum of the star and the magnetic diffusivity are presented. For slow star's rotation the accretion flow is similar to that in non-rotating case, but in the case of fast rotation the structure of the subsonic accretion flow is fundamentally different and includes a region of ``propeller'' outflow. The methods and results described here are of general interest and can be applied to systems where matter accretes with low angular momentum.

Yu. M. Toropin; O. D. Toropina; M. M. Romanova; V. V. Savelyev; V. M. Chechetkin; R. V. E. Lovelace

1998-11-17

61

Low Q electrically small linear and elliptical polarized spherical dipole antennas  

Microsoft Academic Search

Electrically small antennas are generally presumed to exhibit high impedance mismatch (high VSWR), low efficiency, high quality factor (Q); and, therefore, narrow operating bandwidth. For an electric or magnetic dipole antenna, there is a fundamental lower bound for the quality factor that is determined as a function of the antenna's occupied physical volume. In this paper, the quality factor of

Steven R. Best

2005-01-01

62

A Zeeman slower based on magnetic dipoles  

NASA Astrophysics Data System (ADS)

A transverse Zeeman slower composed of an array of compact discrete neodymium magnets is considered. A simple and precise model of such a slower based on magnetic dipoles is developed. The theory of a general Zeeman slower is modified to include spatial nonuniformity of the slowing laser beam intensity due to its convergence and absorption by slowed atoms. The slower needs no high currents or water cooling and the spatial distribution of its magnetic field can be adjusted. In addition the slower provides a possibility to cool the slowed atoms transversally along the whole length of the slower. Such a slower would be ideal for transportable optical atomic clocks and their future applications in space physics.

Ovchinnikov, Yuri B.

2007-08-01

63

Magnetic Dipole Interaction on a Square Lattice  

NASA Astrophysics Data System (ADS)

We have studied interactions and phase transitions of circular magnetic islands with dipole character on a square lattice. By lithographic means we have prepared square patterns of periodicity 300 nm decorated with circular islands of 150 nm diameter using Pd0.87Fe0.13 as magnetic alloy. Below the Curie temperature of 260 K each island is in a ferromagnetic, single domain state with dipolar character and zero in-plane anisotropy. Below a second transition temperature the dipoles start to interact. MOKE measurements show a characteristic change in the magnetic hysteresis for temperatures below 160 K with increasing coercivity for decreasing temperatures. Furthermore, below the second transition the in-plane hysteresis becomes anisotropic, having an easy axis along [10] direction and a hard axis along [11] direction. SPEEM experiments at BESSY II of the HZB with circularly polarized incident photons tuned to the Fe L3 - edge show clearly the development of dipolar chains below the second phase transition that increase in length with decreasing temperature. Neighbouring chains are found to be oriented parallel as well as antiparallel.

Zabel, Hartmut; Ewerlin, Melanie; Demirbas, Derya; Bruessing, Frank; Kronast, Florian

2013-03-01

64

Magnetic dipole discharges. I. Basic properties  

NASA Astrophysics Data System (ADS)

A simple discharge is described which uses a permanent magnet as a cold cathode and the metallic chamber wall as an anode. The magnet's equator is biased strongly negative, which produces secondary electrons due to the impact of energetic ions. The emitted electrons are highly confined by the strong dipolar magnetic field and the negative potential in the equatorial plane of the magnet. The emitted electrons ionize near the sheath and produce further electrons, which drift across field lines to the anode while the nearly unmagnetized ions are accelerated back to the magnet. A steady state discharge is maintained at neutral pressures above 10-3 mbar. This is the principle of magnetron discharges, which commonly use cylindrical and planar cathodes rather than magnetic dipoles as cathodes. The discharge properties have been investigated in steady state and pulsed mode. Different magnets and geometries have been employed. The role of a background plasma has been investigated. Various types of instabilities have been observed such as sheath oscillations, current-driven turbulence, relaxation instabilities due to ionization, and high frequency oscillations created by sputtering impulses, which are described in more detail in companion papers. The discharge has also been operated in reactive gases and shown to be useful for sputtering applications.

Stenzel, R. L.; Urrutia, J. M.; Teodorescu-Soare, C. T.; Ionita, C.; Schrittwieser, R.

2013-08-01

65

Magnetic dipole discharges. I. Basic properties  

SciTech Connect

A simple discharge is described which uses a permanent magnet as a cold cathode and the metallic chamber wall as an anode. The magnet's equator is biased strongly negative, which produces secondary electrons due to the impact of energetic ions. The emitted electrons are highly confined by the strong dipolar magnetic field and the negative potential in the equatorial plane of the magnet. The emitted electrons ionize near the sheath and produce further electrons, which drift across field lines to the anode while the nearly unmagnetized ions are accelerated back to the magnet. A steady state discharge is maintained at neutral pressures above 10{sup ?3} mbar. This is the principle of magnetron discharges, which commonly use cylindrical and planar cathodes rather than magnetic dipoles as cathodes. The discharge properties have been investigated in steady state and pulsed mode. Different magnets and geometries have been employed. The role of a background plasma has been investigated. Various types of instabilities have been observed such as sheath oscillations, current-driven turbulence, relaxation instabilities due to ionization, and high frequency oscillations created by sputtering impulses, which are described in more detail in companion papers. The discharge has also been operated in reactive gases and shown to be useful for sputtering applications.

Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)] [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States); Teodorescu-Soare, C. T.; Ionita, C.; Schrittwieser, R. [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)] [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)

2013-08-15

66

Electricity and Magnetism  

NSDL National Science Digital Library

In this two-part activity, students learn about electromagnetism by constructing electromagnets and observing their behavior. They will discover that there is a close relationship between electricity and magnetism in that moving magnets can induce electric currents and that electric currents can cause magnetism. They also learn that electric current flowing in a wire creates a magnetic field around it.

67

Confronting Higgcision with Electric Dipole Moments  

E-print Network

Current data on the signal strengths and angular spectrum of the 125.5 GeV Higgs boson still allow a CP-mixed state, namely, the pseudoscalar coupling to the top quark can be as sizable as the scalar coupling: $C_u^S \\approx C_u^P =1/2$. CP violation can then arise and manifest in sizable electric dipole moments (EDMs). In the framework of two-Higgs-doublet models, we not only update the Higgs precision (Higgcision) study on the couplings with the most updated Higgs signal strength data, but also compute all the Higgs-mediated contributions from the 125.5 GeV Higgs boson to the EDMs, and confront the allowed parameter space against the existing constraints from the EDM measurements of Thallium, neutron, Mercury, and Thorium monoxide. We found that the combined EDM constraints restrict the pseudoscalar coupling to be less than about $10^{-2}$, unless there are contributions from other Higgs bosons, supersymmetric particles, or other exotic particles that delicately cancel the current Higgs-mediated contributions.

Kingman Cheung; Jae Sik Lee; Eibun Senaha; Po-Yan Tseng

2014-03-19

68

Electric dipole polarizability and the neutron skin  

NASA Astrophysics Data System (ADS)

The recent high-resolution measurement of the electric dipole (E1) polarizability ?D in 208Pb [A. Tamii , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.107.062502 107, 062502 (2011)] provides a unique constraint on the neutron-skin thickness of this nucleus. The neutron-skin thickness rskin of 208Pb is a quantity of critical importance for our understanding of a variety of nuclear and astrophysical phenomena. To assess the model dependence of the correlation between ?D and rskin, we carry out systematic calculations for 208Pb, 132Sn, and 48Ca based on the nuclear density functional theory using both nonrelativistic and relativistic energy density functionals. Our analysis indicates that whereas individual models exhibit a linear dependence between ?D and rskin, this correlation is not universal when one combines predictions from a host of different models. By averaging over these model predictions, we provide estimates with associated systematic errors for rskin and ?D for the nuclei under consideration. We conclude that precise measurements of rskin in both 48Ca and 208Pb—combined with the recent measurement of ?D—should significantly constrain the isovector sector of the nuclear energy density functional.

Piekarewicz, J.; Agrawal, B. K.; Colò, G.; Nazarewicz, W.; Paar, N.; Reinhard, P.-G.; Roca-Maza, X.; Vretenar, D.

2012-04-01

69

Confronting Higgcision with electric dipole moments  

NASA Astrophysics Data System (ADS)

Current data on the signal strengths and angular spectrum of the 125.5 GeV Higgs boson still allow a CP-mixed state, namely, the pseudoscalar coupling to the top quark can be as sizable as the scalar coupling: C {/u S } ? C {/u P } = 1/2. CP violation can then arise and manifest in sizable electric dipole moments (EDMs). In the framework of two-Higgs-doublet models, we not only update the Higgs precision (Higgcision) study on the couplings with the most updated Higgs signal strength data, but also compute all the Higgs-mediated contributions from the 125.5 GeV Higgs boson to the EDMs, and confront the allowed parameter space against the existing constraints from the EDM measurements of Thallium, neutron, Mercury, and Thorium monoxide. We found that the combined EDM constraints restrict the pseudoscalar coupling to be less than about 10-2, unless there are contributions from other Higgs bosons, supersymmetric particles, or other exotic particles that delicately cancel the current Higgs-mediated contributions.

Cheung, Kingman; Lee, Jae Sik; Senaha, Eibun; Tseng, Po-Yan

2014-06-01

70

The search for permanent electric dipole moments  

SciTech Connect

Permanent electric dipole moments (EDMs) of fundamental systems with spin - particles, nuclei, atoms or molecules violate parity and time reversal invariance. Invoking the CPT theorem, time reversal violation implies CP violation. Although CP-violation is implemented in the standard electro-weak theory, EDM generated this way remain undetectably small. However, this CP-violation also appears to fail explaining the observed baryon asymmetry of our universe. Extensions of the standard theory usually include new sources of CP violation and often predict sizeable EDMs. EDM searches in different systems are complementary and various efforts worldwide are underway and no finite value has been established yet. The prototype of an EDM search is the pursuit of the EDM of the neutron. It has the longest history and at the same time is at the forefront of present research. The talk aims at giving an overview of the field with emphasis on our efforts within an international collaboration at PSI, nedm.web.psi.ch.

Kirch, Klaus [PSI-Villigen - ETH Zürich

2013-02-13

71

Controlling magnetic dipole transition with magnetic plasmonic structures.  

PubMed

A plasmonic structure with double gold patches is proposed for enhancing the spontaneous emission of a magnetic dipole transition through a magnetic hot area. A Purcell factor of nearly 2000 can be obtained at optical frequencies together with a low sensitivity in spatial and spectral mismatches between the light emitter and the resonance mode. The associated resonance can be tuned from the visible to the IR frequencies, enabling efficient control of forbidden transitions using plasmonic structures. PMID:21686023

Feng, Tianhua; Zhou, Ying; Liu, Dahe; Li, Jensen

2011-06-15

72

The electric dipole moment of cobalt monoxide, CoO  

SciTech Connect

A number of low-rotational lines of the E{sup 4}?{sub 7/2}???X{sup 4}?{sub 7/2} (1,0) band system of cobalt monoxide, CoO, were recorded field free and in the presence of a static electric field. The magnetic hyperfine parameter, h{sub 7/2}, and the electron quadrupole parameter, eQq{sub 0}, for the E{sup 4}?{sub 7/2}(? = 1) state were optimized from the analysis of the field-free spectrum. The permanent electric dipole moment, ?{sup -vector}{sub el}, for the X{sup 4}?{sub 7/2} (? = 0) and E{sup 4}?{sub 7/2} (? = 1) states were determined to be 4.18 ± 0.05 D and 3.28 ± 0.05 D, respectively, from the analysis of the observed Stark spectra of F? = 7???F? = 6 branch feature in the Q(7/2) line and the F? = 8???F? = 7 branch feature in the R(7/2) line. The measured dipole moments of CoO are compared to those from theoretical predictions and the trend across the 3d-metal monoxide series discussed.

Zhuang, Xiujuan, E-mail: zhuangxj@hnu.edu.cn [College of Physics and Microelectronics Science, Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, Hunan University, Changsha 410082 (China)] [College of Physics and Microelectronics Science, Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, Hunan University, Changsha 410082 (China); Steimle, Timothy C. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)] [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)

2014-03-28

73

Electric and magnetic monopoles in rotating Bose-Einstein condensates  

Microsoft Academic Search

We show that by virtue of the Röntgen interaction, a vortex of order n in a Bose-Einstein condensate (BEC), in which the constituent atoms are characterized by an electric dipole, gives rise to a magnetic monopole distribution, which correctly preserves magnetic charge neutrality. If, on the other hand, the BEC atoms are characterized by a magnetic dipole, we show that

C. R. Bennett; L. G. Boussiakou; M. Babiker

2001-01-01

74

Magnetostatic potential theory and the lunar magnetic dipole field  

NASA Technical Reports Server (NTRS)

The lunar magnetic dipole moment is discussed. It is proposed that if a primordial core magnetic field existed, it would give rise to a present day nonzero external dipole magnetic field. This conclusion is based on the assumption that the lunar mantle is at least slightly ferromagnetic, and thus would maintain a permanent magnetization after the disappearance of the core magnetic field. Using a simple mathematical model of the moon, calculations are performed which support this hypothesis.

Goldstein, M. L.

1975-01-01

75

Limit on the Electron Electric Dipole Moment in Gadolinium-Iron Garnet  

NASA Astrophysics Data System (ADS)

A new method for the detection of the electron electric dipole moment (EDM) using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the sample’s magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron EDM of 5×10-24ecm, which is a factor of 40 below the limit obtained from the only previous solid-state EDM experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization.

Heidenreich, B. J.; Elliott, O. T.; Charney, N. D.; Virgien, K. A.; Bridges, A. W.; McKeon, M. A.; Peck, S. K.; Krause, D., Jr.; Gordon, J. E.; Hunter, L. R.; Lamoreaux, S. K.

2005-12-01

76

Collective electric and magnetic plasmonic resonances in spherical nanoclusters  

E-print Network

with the electric dipole efficiency Q sca indicating thatthe electric resonance the p e scattering efficiency Q scaelectric and magnetic resonances, previously identified from the analysis of the extinction and scattering efficiencies,

Vallecchi, Andrea; Albani, Matteo; Capolino, Filippo

2011-01-01

77

Theoretical electric dipole moments of SiH, GeH and SnH  

NASA Astrophysics Data System (ADS)

Accurate theoretical dipole moments have been computed for the X2Pi ground states of Si(-)H(+) (0.118 D), Ge(+)H(-) (0.085 D), and Sn(+)H(-) (0.357 D). The trend down the periodic table is regular and follows that expected from the electronegativities of the group IV atoms. The dipole moment of 1.24 + or - 0.1 D for GeH recently derived by Brown, Evenson and Sears (1985) from the relative intensities of electric and magnetic dipole transitions in the 10-micron spectrum of the X2Pi state is seriously questioned.

Pettersson, L. G. M.; Langhoff, S. R.

1986-04-01

78

Switchable magnetic dipole induced guided vortex motion N. Verellen,1  

E-print Network

Switchable magnetic dipole induced guided vortex motion N. Verellen,1 A. V. Silhanek,1,a W 2008; published online 16 July 2008 We present evidence of magnetically controlled vortex motion axes of the square lattice of dipoles. This guided vortex motion can be rerouted by 90° simply changing

Moshchalkov, Victor V.

79

a Measurement of the Electric Dipole Moment of the Electron  

NASA Astrophysics Data System (ADS)

A fundamental particle cannot have an electric dipole moment (EDM) unless both the time reversal (T) and parity (P) symmetries are broken. Therefore the measurement of a such a moment is of great fundamental interest. We have measured the electric dipole moment of the thallium atom to be d_{a} = (1.6 +/- 5.0) times 10^{-24}e cm. A known theoretical relation between the thallium ground state atomic dipole moment and the electric dipole moment of the electron, d_{a}/d _{e} = -585, allows us to state that d_{e} < 2.7 +/- 8.3 times 10^{-27}e cm. Extreme care was taken towards limiting systematics. We believe that continuing work on this measurement will yield a better limit by at least a factor of 5.

Ross, Stephen Beames

80

Measurement of the electron's electric dipole moment using YbF molecules: methods and data analysis  

E-print Network

We recently reported a new measurement of the electron's electric dipole moment using YbF molecules [Nature 473, 493 (2011)]. Here, we give a more detailed description of the methods used to make this measurement, along with a fuller analysis of the data. We show how our methods isolate the electric dipole moment from imperfections in the experiment that might mimic it. We describe the systematic errors that we discovered, and the small corrections that we made to account for these. By making a set of additional measurements with greatly exaggerated experimental imperfections, we find upper bounds on possible uncorrected systematic errors which we use to determine the systematic uncertainty in the measurement. We also calculate the size of some systematic effects that have been important in previous electric dipole moment measurements, such as the motional magnetic field effect and the geometric phase, and show them to be negligibly small in the present experiment. Our result is consistent with an electric di...

Kara, D M; Hudson, J J; Sauer, B E; Tarbutt, M R; Hinds, E A

2012-01-01

81

Analysis and design of short, iron-free dipole magnets  

SciTech Connect

Iron-free, dipole magnets are used extensively as steering magnets to correct for the bending, induced by extraneous magnetic fields, of particle beams that are being transported in vacuum. Generally, the dipoles are long enough that the space occupied by the end conductors is small compared to the overall magnet length. In a recent application, however, this criteria did not apply. This has motivated a reanalysis of the characteristics of a system of small aspect ratio (length/diameter) dipoles that are spaced at relatively large axial distances.

Harvey, A.R.

1981-10-21

82

Magnets and Electricity - Creating Magnetism with Electricity  

NSDL National Science Digital Library

This cooperative classroom activity will allow students to apply their knowledge of magnetism and electricity. The students will create a circuit that lights a flashlight bulb and simultaneously practice the skills of prediction, observation, inferrence, recording, investigation and communication.

83

Equilibrium and stability studies of plasmas confined in a dipole magnetic field using magnetic measurements  

E-print Network

The Levitated Dipole Experiment (LDX) is the first experiment of its kind to use a levitated current ring to confine a plasma in a dipole magnetic field. Unlike most other confinement devices, plasma compressibility ...

Karim, Ishtak

2007-01-01

84

Dual aperture dipole magnet with second harmonic component  

DOEpatents

An improved dual aperture dipole electromagnet includes a second-harmonic frequency magnetic guide field winding which surrounds first harmonic frequency magnetic guide field windings associated with each aperture. The second harmonic winding and the first harmonic windings cooperate to produce resultant magnetic waveforms in the apertures which have extended acceleration and shortened reset portions of electromagnet operation.

Praeg, W.F.

1983-08-31

85

Dual aperture dipole magnet with second harmonic component  

DOEpatents

An improved dual aperture dipole electromagnet includes a second-harmonic frequency magnetic guide field winding which surrounds first harmonic frequency magnetic guide field windings associated with each aperture. The second harmonic winding and the first harmonic windings cooperate to produce resultant magnetic waveforms in the apertures which have extended acceleration and shortened reset portions of electromagnet operation.

Praeg, Walter F. (Palos Park, IL)

1985-01-01

86

Electrically short dipoles with a nonlinear load, a revisited analysis  

Microsoft Academic Search

We reexamine the characteristics of electrically short dipoles with nonlinear loads and, specifically, the early work of Motohisa Kanda (1980, 1983). Although this topic has been examined in great detail in the past, some inconsistencies between numerical and analytical results are apparent, and these have not been previously addressed. We show that these inconsistencies were due to only periodic sampling

John M. Ladbury; Dennis G. Camell

2002-01-01

87

Complete electric dipole response and the neutron skin in 208Pb.  

PubMed

A benchmark experiment on (208)Pb shows that polarized proton inelastic scattering at very forward angles including 0° is a powerful tool for high-resolution studies of electric dipole (E1) and spin magnetic dipole (M1) modes in nuclei over a broad excitation energy range to test up-to-date nuclear models. The extracted E1 polarizability leads to a neutron skin thickness r(skin) = 0.156(-0.021)(+0.025) fm in (208)Pb derived within a mean-field model [Phys. Rev. C 81, 051303 (2010)], thereby constraining the symmetry energy and its density dependence relevant to the description of neutron stars. PMID:21902316

Tamii, A; Poltoratska, I; von Neumann-Cosel, P; Fujita, Y; Adachi, T; Bertulani, C A; Carter, J; Dozono, M; Fujita, H; Fujita, K; Hatanaka, K; Ishikawa, D; Itoh, M; Kawabata, T; Kalmykov, Y; Krumbholz, A M; Litvinova, E; Matsubara, H; Nakanishi, K; Neveling, R; Okamura, H; Ong, H J; Ozel-Tashenov, B; Ponomarev, V Yu; Richter, A; Rubio, B; Sakaguchi, H; Sakemi, Y; Sasamoto, Y; Shimbara, Y; Shimizu, Y; Smit, F D; Suzuki, T; Tameshige, Y; Wambach, J; Yamada, R; Yosoi, M; Zenihiro, J

2011-08-01

88

Complete electric dipole response and the neutron skin in 208Pb  

E-print Network

A benchmark experiment on 208Pb shows that polarized proton inelastic scattering at very forward angles including 0{\\deg} is a powerful tool for high-resolution studies of electric dipole (E1) and spin magnetic dipole (M1) modes in nuclei over a broad excitation energy range to test up-to-date nuclear models. The extracted E1 polarizability leads to a neutron skin thickness r_skin = 0.156+0.025-0.021 fm in 208Pb derived within a mean-field model [Phys. Rev. C 81, 051303 (2010)], thereby constraining the symmetry energy and its density dependence, relevant to the description of neutron stars.

A. Tamii; I. Poltoratska; P. von Neumann-Cosel; Y. Fujita; T. Adachi; C. A. Bertulani; J. Carter; M. Dozono; H. Fujita; K. Fujita; K. Hatanaka; A. M. Heilmann; D. Ishikawa; M. Itoh; H. J. Ong; T. Kawabata; Y. Kalmykov; E. Litvinova; H. Matsubara; K. Nakanishi; R. Neveling; H. Okamura; B. Özel-Tashenov; V. Yu. Ponomarev; A. Richter; B. Rubio; H. Sakaguchi; Y. Sakemi; Y. Sasamoto; Y. Shimbara; Y. Shimizu; F. D. Smit; T. Suzuki; Y. Tameshige; J. Wambach; R. Yamada; M. Yosoi; J. Zenihiro

2011-05-30

89

Electricity and Magnetic Fields  

NSDL National Science Digital Library

The grand challenge for this legacy cycle unit is for students to design a way to help a recycler separate aluminum from steel scrap metal. In previous lessons, they have looked at how magnetism might be utilized. In this lesson, students think about how they might use magnets and how they might confront the problem of turning the magnetic field off. Through the accompanying activity students explore the nature of an electrically induced magnetic field and its applicability to the needed magnet.

VU Bioengineering RET Program,

90

Ising interaction between orbital angular momentum states through magnetic dipole-dipole interaction  

E-print Network

In quantum information processing, one of the most preferred interaction between qubits is Ising type interaction. We propose a scheme to implement exact Ising interaction using orbital angular momentum states of any physical system that has magnetic dipole moment proportional to its angular momentum. If two qubit levels are chosen among highest-M states, magnetic dipole-dipole interaction gives an exact mathematical form of the Ising interaction. Real physical systems applicable to our scheme can possibly be rotational states of molecules, electronic orbital states of atoms, flux states of superconducting rings, or electronic states of nitrogen-vacancy centers in diamond. To investigate the feasibility of our scheme, we present brief analysis on some physical systems.

Sang Jae Yun; Jaewan Kim; Chang Hee Nam

2014-03-11

91

Constraining the neutrino magnetic dipole moment from white dwarf pulsations  

E-print Network

Pulsating white dwarf stars can be used as astrophysical laboratories to constrain the properties of weakly interacting particles. Comparing the cooling rates of these stars with the expected values from theoretical models allows us to search for additional sources of cooling due to the emission of axions, neutralinos, or neutrinos with magnetic dipole moment. In this work, we derive an upper bound to the neutrino magnetic dipole moment using an estimate of the rate of period change of the pulsating DB white dwarf star PG 1351+489. By comparing the theoretical rate of change of period expected for this star with the rate of change of period with time of PG 1351+489, we assess the possible existence of additional cooling by neutrinos with magnetic dipole moment. Our models suggest the existence of some additional cooling in this pulsating DB white dwarf, consistent with a non-zero magnetic dipole moment. Our upper limit for the neutrino magnetic dipole moment is somewhat less restrictive than, but still compatible with, other limits inferred from the white dwarf luminosity function or from the color-magnitude diagram of the Globular cluster M5. Further improvements of the measurement of the rate of period change of the dominant pulsation mode of PG 1351+489 will be necessary to confirm our bound.

Alejandro H. Córsico; Leandro G. Althaus; Marcelo M. Miller Bertolami; S. O. Kepler; Enrique García-Berro

2014-07-25

92

Limit on the electron electric dipole moment in gadolinium-iron garnet.  

PubMed

A new method for the detection of the electron electric dipole moment (EDM) using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the sample's magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron EDM of 5 x 10(-24)e cm, which is a factor of 40 below the limit obtained from the only previous solid-state EDM experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization. PMID:16384457

Heidenreich, B J; Elliott, O T; Charney, N D; Virgien, K A; Bridges, A W; McKeon, M A; Peck, S K; Krause, D; Gordon, J E; Hunter, L R; Lamoreaux, S K

2005-12-16

93

Contribution of W{sup {plus_minus}}H{sup {minus_plus}}Z{sub i} vertices to anomalous magnetic dipole and electric quadrupole moments of the W boson in the extra U(1) superstring-inspired model  

SciTech Connect

W{sup {plus_minus}}H{sup {minus_plus}}Z{sub i} (i=1,2) vertices available exclusively in the extra U(1) superstring-inspired model have been utilized to evaluate the W-W-{gamma} vertex contribution at the one loop level. The expressions so obtained have been used to estimate the anomalous magnetic dipole moment ({Delta}k{sub WZ{sub i}H}) and electric quadrupole moment ({Delta}Q{sub WZ{sub i}H}) of the W{sup +} boson. The contribution of the Z{sub 2}WW vertex is also added to these values. The resulting values in the unit of ({minus}{alpha}/{pi}) when the Z{sub 2} mass varies from 555 to 620 GeV have the following ranges: for m{sub t(CDF)}=175.6GeV, {Delta}k{sub [U(1)]}, from 25.402 to 41.559, {Delta}Q{sub [U(1)]}, from 6.886 to 10.858; for m{sub t(D0)}=169GeV, {Delta}k{sub [U(1)]}, from 20.821 to 34.121, {Delta}Q{sub [U(1)]}, from 5.738 to 9.033. These are larger than the standard model radiative correction contributions but an order of magnitude smaller than those predicted by the composite model of Abbott and Farhi.

Sharma, N.K.; Saxena, P.; Singh, S.; Nagawat, A.K.; Sahu, R.S. [Department of Physics, University of Rajasthan, Jaipur 302 004 (India)] [Department of Physics, University of Rajasthan, Jaipur 302 004 (India)

1997-10-01

94

Bistability between equatorial and axial dipoles during magnetic field reversals.  

PubMed

Numerical simulations of the geodynamo in the presence of heterogeneous heating are presented. We study the dynamics and the structure of the magnetic field when the equatorial symmetry of the flow is broken. If the symmetry breaking is sufficiently strong, the m=0 axial dipolar field is replaced by a hemispherical magnetic field, dominated by an oscillating m=1 magnetic field. Moreover, for moderate symmetry breaking, a bistability between the axial and the equatorial dipole is observed. In this bistable regime, the axial magnetic field exhibits chaotic switches of its polarity, involving the equatorial dipole during the transition period. This new scenario for magnetic field reversals is discussed within the framework of Earth's dynamo. PMID:23003961

Gissinger, Christophe; Petitdemange, Ludovic; Schrinner, Martin; Dormy, Emmanuel

2012-06-01

95

Plasma stability in a dipole magnetic field  

E-print Network

The MHD and kinetic stability of an axially symmetric plasma, confined by a poloidal magnetic field with closed lines, is considered. In such a system the stabilizing effects of plasma compression and magnetic field ...

Simakov, Andrei N., 1974-

2001-01-01

96

Canted-spin-caused electric dipoles: A local symmetry theory  

NASA Astrophysics Data System (ADS)

A pair of magnetic atoms with canted spins Sa,Sb can give rise to an electric dipole moment P. Several forms for the behavior of such a moment have appeared in the theoretical literature, some of which have been invoked to explain experimental results found in various multiferroic materials. The forms that require canting of the spins are P1?R×(Sa×Sb),P2?Sa×Sb, and P3?SaR·Sa-SbR·Sb, where R is the relative position of the atoms and Sa,Sb are unit vectors. To unify and generalize these various forms, we consider P as the most general quadratic function of the spin components that vanishes whenever Sa and Sb are collinear, i.e., we consider the most general expressions that require spin canting. The study reveals new forms. We generalize to the vector P, Moriya’s symmetry considerations regarding the (scalar) Dzyaloshinskii-Moriya energy D·Sa×Sb (which led to restrictions on D). This provides a rigorous symmetry argument that shows that P1 is allowed no matter how high the symmetry of the atoms plus environment, and gives restrictions for all other contributions. The analysis leads to the suggestion of terms omitted in the existing microscopic models, suggests a new mechanism behind the ferroelectricity found in the “proper screw structure” of CuXO2, X=Fe,Cr, and predicts an unusual antiferroelectric ordering in the antiferromagnetically and ferroelectrically ordered phase of RbFe(MoO4)2.

Kaplan, T. A.; Mahanti, S. D.

2011-05-01

97

An update on passive correctors for the SSC dipole magnets  

SciTech Connect

The concept of correction of the magnetization sextupole became a topic of discussion as soon as it was realized that superconductor magnetization could have a serious effect on the SSC beam during injection. Several methods of correction were proposed. These included (1) correction with active bore tube windings like those on the HERA machine which correct out magnetization sextupole and the sextupole due to iron saturation, (2) correction with persistent sextupole windings mounted on the bore tube (3) correction using passive superconductor (4) correction using ferromagnetic material, and (5) correction using oriented magnetized materials. This report deals with the use of passive superconductor to correct the magnetization sextupole. Two basic methods are explored in this report: (1) One can correct the magnetization sextupole by changing the diameter of the superconductor filaments in one or more blocks of the SSC dipole. (2) One can correct the magnetization sextupole and decapole by mounting passive superconducting wires on the inside of the SSC dipole coil bore. In addition, an assessment of the contribution of each conductor in the dipole to the magnetization sextupole and decapole is shown. 38 refs, 25 figs., 15 tabs.

Green, M.A.

1991-05-01

98

Electric dipole moments of nanosolvated acid molecules in water clusters  

E-print Network

The electric dipole moments of $(H_{2}O)_{n}DCl$ ($n=3-9$) clusters have been measured by the beam deflection method. Reflecting the (dynamical) charge distribution within the system, the dipole moment contributes information about the microscopic structure of nanoscale solvation. The addition of a DCl molecule to a water cluster results in a strongly enhanced susceptibility. There is evidence for a noticeable rise in the dipole moment occurring at $n\\approx5-6$. This size is consistent with predictions for the onset of ionic dissociation. Additionally, a molecular dynamics model suggests that even with a nominally bound impurity an enhanced dipole moment can arise due to the thermal and zero point motion of the proton and the water molecules. The experimental measurements and the calculations draw attention to the importance of fluctuations in defining the polarity of water-based nanoclusters, and generally to the essential role played by motional effects in determining the response of fluxional nanoscale sy...

Guggemos, Nicholas; Kresin, Vitaly V

2015-01-01

99

Probing Electric and Magnetic Vacuum Fluctuations with Quantum Dots  

NASA Astrophysics Data System (ADS)

The electromagnetic-vacuum-field fluctuations are intimately linked to the process of spontaneous emission of light. Atomic emitters cannot probe electric- and magnetic-field fluctuations simultaneously because electric and magnetic transitions correspond to different selection rules. In this Letter we show that semiconductor quantum dots are fundamentally different and are capable of mediating electric-dipole, magnetic-dipole, and electric-quadrupole transitions on a single electronic resonance. As a consequence, quantum dots can probe electric and magnetic fields simultaneously and can thus be applied for sensing the electromagnetic environment of complex photonic nanostructures. Our study opens the prospect of interfacing quantum dots with optical metamaterials for tailoring the electric and magnetic light-matter interaction at the single-emitter level.

Tighineanu, P.; Andersen, M. L.; Sørensen, A. S.; Stobbe, S.; Lodahl, P.

2014-07-01

100

Probing electric and magnetic vacuum fluctuations with quantum dots  

E-print Network

The electromagnetic-vacuum-field fluctuations are intimately linked to the process of spontaneous emission of light. Atomic emitters cannot probe electric- and magnetic-field fluctuations simultaneously because electric and magnetic transitions correspond to different selection rules. In this paper we show that semiconductor quantum dots are fundamentally different and are capable of mediating electric-dipole, magnetic-dipole, and electric-quadrupole transitions on a single electronic resonance. As a consequence, quantum dots can probe electric and magnetic fields simultaneously and can thus be applied for sensing the electromagnetic environment of complex photonic nanostructures. Our study opens the prospect of interfacing quantum dots with optical metamaterials for tailoring the electric and magnetic light-matter interaction at the single-emitter level.

Petru Tighineanu; Mads Lykke Andersen; Anders Søndberg Sørensen; Søren Stobbe; Peter Lodahl

2014-04-04

101

Probing electric and magnetic vacuum fluctuations with quantum dots.  

PubMed

The electromagnetic-vacuum-field fluctuations are intimately linked to the process of spontaneous emission of light. Atomic emitters cannot probe electric- and magnetic-field fluctuations simultaneously because electric and magnetic transitions correspond to different selection rules. In this Letter we show that semiconductor quantum dots are fundamentally different and are capable of mediating electric-dipole, magnetic-dipole, and electric-quadrupole transitions on a single electronic resonance. As a consequence, quantum dots can probe electric and magnetic fields simultaneously and can thus be applied for sensing the electromagnetic environment of complex photonic nanostructures. Our study opens the prospect of interfacing quantum dots with optical metamaterials for tailoring the electric and magnetic light-matter interaction at the single-emitter level. PMID:25105618

Tighineanu, P; Andersen, M L; Sørensen, A S; Stobbe, S; Lodahl, P

2014-07-25

102

Local spin torque induced by electron electric dipole moment in the Ybf molecule  

NASA Astrophysics Data System (ADS)

In this study, we show the modification of the equation of motion of the electronic spin, which is derived by the quantum electron spin vorticity principle, by the effect of the electron electric dipole moment (EDM). To investigate the new contribution to spin torque by EDM, using first principle calculations, we visualize distributions of the local spin angular momentum density and local spin torque density of the YbF molecule on which the static electric field and magnetic field are applied at t = 0.

Fukuda, Masahiro; Senami, Masato; Ogiso, Yoji; Tachibana, Akitomo

2014-10-01

103

DESIGN STUDY OF THE DIPOLE MAGNET FOR THE RHIC EBIS HIGH ENERGY TRANSPORT LINE  

E-print Network

DESIGN STUDY OF THE DIPOLE MAGNET FOR THE RHIC EBIS HIGH ENERGY TRANSPORT LINE Takeshi Kanesue studies of the dipole magnet for EBIS HEBT line is proceeding. The RHIC EBIS is a new high current highly charged heavy ion preinjector for RHIC. The dipole magnet discussed in this paper will be used to guide

104

Supersolid phase in atomic gases with magnetic dipole interaction  

SciTech Connect

A major obstacle for the experimental realization of a supersolid phase with cold atomic gases in an optical lattice is the weakness of the nearest-neighbor interactions achievable via magnetic dipole-dipole interactions. In this paper, we show that by using a large filling of atoms within each well, the characteristic energy scales are strongly enhanced. Within this regime, the system is well described by the rotor model, and the qualitative behavior of the phase diagram derives from mean-field theory. We find a stable supersolid phase for realistic parameters with chromium atoms.

Buehler, Adam; Buechler, Hans Peter [Institute for Theoretical Physics III, University of Stuttgart, Pfaffenwaldring 57, D-70550 (Germany)

2011-08-15

105

Mechanism of formation of a dipole magnetic field in the central regions of active galaxies  

NASA Astrophysics Data System (ADS)

A model of the formation of large-scale magnetic fields of dipole configuration in the central regions (r ? 100 pc) of active galaxies is studied. It is assumed that these regions contain a rapidly rotating, highly ionized gas (? ? 5·10-15 sec, Ne ? 103 cm-3). Ionized matter escapes from the center of the region with a velocity of several hundred km/sec and is entrained by the rotation of the surrounding medium. Biermann's "battery" effect [L. Biermann, Z. Naturforsch., 5a, 65 (1950)] operates under such conditions, and circular electric currents are formed in the medium, which amplify the dipole magnetic fields. During the active phase of a galaxy, about 108 years, the magnetic field strength at the boundary of this region may reach 10-4 10-3 G.

Andreasyan, R. R.

1996-01-01

106

Magnetic field properties of Fermilab Energy-Saver dipoles  

SciTech Connect

At Fermilab we have operated a production line for the fabrication of 901 21 foot long superconducting dipoles for use in the Energy Saver/Doubler. At any one time 772 of these dipoles are installed in the accelerator and 62 in beamlines; the remainder are spares. Magnetic field data are now available for most of these dipoles; in this paper we present some of these data which show that we have been able to maintain the necessary consistency in field quality throughout the production process. Specifically we report harmonic field coefficients, showing that the mechanical design permits substantial reduction of the magnitudes of the normal and skew quadrupole harmonic coefficients; field shape profiles; integral field data; and field angle data.

Hanft, R.; Brown, B.C.; Cooper, W.E.; Gross, D.A.; Michelotti, L.; Schmidt, E.E.; Turkot, F.

1983-03-01

107

Acoustic dipole radiation model for magnetoacoustic tomography with magnetic induction  

NASA Astrophysics Data System (ADS)

An acoustic dipole radiation model for magnetoacoustic tomography with magnetic induction (MAT-MI) is proposed, based on the analyses of one-dimensional tissue vibration, three-dimensional acoustic dipole radiation and acoustic waveform detection with a planar piston transducer. The collected waveforms provide information about the conductivity boundaries in various vibration intensities and phases due to the acoustic dipole radiation pattern. Combined with the simplified back projection algorithm, the conductivity configuration of the measured layer in terms of shape and size can be reconstructed with obvious border stripes. The numerical simulation is performed for a two-layer cylindrical phantom model and it is also verified by the experimental results of MAT-MI for a tissue-like sample phantom. The proposed model suggests a potential application of conductivity differentiation and provides a universal basis for the further study of conductivity reconstruction for MAT-MI.

Li, Yi-Ling; Ma, Qing-Yu; Zhang, Dong; Xia, Rong-Min

2011-08-01

108

Electrically silent magnetic fields.  

PubMed Central

There has been a significant controversy over the past decade regarding the relative information content of bioelectric and biomagnetic signals. In this paper we present a new, theoretical example of an electrically-silent magnetic field, based on a bidomain model of a cylindrical strand of tissue generalized to include off-diagonal components in the conductivity tensors. The physical interpretation of the off-diagonal components is explained, and analytic expressions for the electrical potential and the magnetic field are found. These expressions show that information not obtainable from electrical potential measurements can be obtained from measurements of the magnetic field in systems with conductivity tensors more complicated than those previously examined. PMID:3779008

Roth, B J; Wikswo, J P

1986-01-01

109

Parity-violating electric-dipole transitions in helium  

NASA Technical Reports Server (NTRS)

The paper examines parity-violating electric-dipole transitions in He in order to gain insight into the reliability of approximate calculations which are carried out for transitions in many-electron atoms. The contributions of the nearest-lying states are computed with a variety of wave functions, including very simple product wave functions, Hartree-Fock functions and Hylleraas-type wave functions with up to 84 parameters. It is found that values of the matrix elements of the parity-violating interaction can differ considerably from the values obtained from the good wave functions, even when these simple wave functions give accurate values for the matrix elements in question

Hiller, J.; Sucher, J.; Bhatia, A. K.; Feinberg, G.

1980-01-01

110

The permanent electric dipole moment of chromium monoxide  

NASA Technical Reports Server (NTRS)

The permanent electric dipole moments for the X 5Pi and B 5pi states of gas-phase CrO have been experimentally determined using the sub-Doppler optical technique of intermodulated fluorescence spectroscopy in conjunction with the Stark effect. The measured values are 3.88 + or - 0.13 and 4.1 + or - 1.8 D for the X and B states, respectively. The theoretical values determined for the X state using multireference CI iterative-natural-orbital and finite-field calculations are in excellent agreement with the experimental value.

Steimle, Timothy C.; Nachman, David F.; Shirley, Jeffrey E.; Bauschlicher, Charles W.; Langhoff, Stephen R.

1989-01-01

111

Magnetic dipole moment determination by near-field analysis  

NASA Technical Reports Server (NTRS)

A method for determining the magnetic moment of a spacecraft from magnetic field data taken in a limited region of space close to the spacecraft. The spacecraft's magnetic field equations are derived from first principles. With measurements of this field restricted to certain points in space, the near-field equations for the spacecraft are derived. These equations are solved for the dipole moment by a least squares procedure. A method by which one can estimate the magnitude of the error in the calculations is also presented. This technique was thoroughly tested on a computer. The test program is described and evaluated, and partial results are presented.

Eichhorn, W. L.

1972-01-01

112

Coil end design for the SSC collider dipole magnet  

SciTech Connect

This paper describes the design of the coil end for the 50mm aperture SSC collider dipole magnets built at Fermilab. The cable paths are determined from both magnetic and mechanical considerations. The end spacers are designed using the developable surface, grouped end approach, which allows the analysis of strain energy within the conductor groups. Techniques for strain energy minimization are presented and the behavior of individual conductors within a group is analyzed. The relationship between optimization of magnetic and mechanical variables is discussed. Requirements of manufacturing and inspection of coil end parts are outlined. 7 refs.

Brandt, J.; Bartlett, N.; Bossert, R.; Carson, J.; Konc, J.; Lee, G. (Fermi National Accelerator Lab., Batavia, IL (United States)); Cook, J. (Argonne National Lab., IL (United States)); Caspi, S. (Lawrence Berkeley Lab., CA (United States)); Gordon, M.; Nobrega, F. (Superconducting Super Collider Lab., Dallas, TX (United States))

1991-07-01

113

LABORATORY VI ELECTRICITY FROM MAGNETISM  

E-print Network

LABORATORY VI ELECTRICITY FROM MAGNETISM Lab VI - 1 In the previous problems you explored the magnetic field and its effect on moving charges. You also saw how electric currents could create magnetic can give rise to electric currents. This is the effect that allows the generation of electricity

Minnesota, University of

114

Measuring molecular electric dipoles using trapped atomic ions and ultrafast laser pulses  

NASA Astrophysics Data System (ADS)

We study a hybrid quantum system composed of an ion and an electric dipole. We show how a trapped ion can be used to measure the small electric field generated by a classical dipole. We discuss the application of this scheme to measure the electric dipole moment of cold polar molecules, whose internal state can be controlled with ultrafast laser pulses, by trapping them in the vicinity of a trapped ion.

Mur-Petit, Jordi; García-Ripoll, Juan José

2015-01-01

115

Dipole and electric quadrupole excitations in 40,48Ca  

NASA Astrophysics Data System (ADS)

Photon scattering experiments have been performed to investigate the structure of the two doubly magic nuclei 40,48Ca. The method is highly selective to induce low-order multipole transitions, i.e., E1, M1, and E2 from the ground state. We determined the energies and spins of excited states and the absolute strengths of the ? decays in a model independent way. We find the summed electric dipole strengths below 10 MeV to exhaust the energy weighted sum rule by 0.023 and 0.27 %, respectively. The summed electric quadrupole strengths are ?B(E2)?=332 e2 fm4 and 407 e2 fm4 for 40Ca and 48Ca, respectively. In order to explain the difference in the E1 strengths of the two isotopes several theoretical models are discussed.

Hartmann, T.; Enders, J.; Mohr, P.; Vogt, K.; Volz, S.; Zilges, A.

2002-03-01

116

Electric dipole polarizabilities of hydrogen and helium isotopes  

SciTech Connect

The electric dipole polarizabilities of {sup 3}H, {sup 3}He, and {sup 4}He are calculated directly using the Schroedinger equation with the latest generation of two- and three-nucleon interactions. These quantities are necessary in order to obtain accurate nuclear-polarization corrections for transitions involving S-waves in one-and two-electron atoms. Our results are compared to previous results, and it is shown that direct calculations of the electric polarizability of {sup 4}He using modern nuclear potentials are smaller than published values calculated using experimental photoabsorption data. The status of this topic is assessed in the context of precise measurements of transitions in one- and two-electron atoms.

Stetcu, I [Los Alamos National Laboratory; Friar, J [Los Alamos National Laboratory; Hayes, A C [Los Alamos National Laboratory; Quaglioni, S [LLNL

2009-01-01

117

Visualizing Special Relativity: The Field of An Electric Dipole Moving at Relativistic Speed  

ERIC Educational Resources Information Center

The electromagnetic field is determined for a time-varying electric dipole moving with a constant velocity that is parallel to its moment. Graphics are used to visualize this field in the rest frame of the dipole and in the laboratory frame when the dipole is moving at relativistic speed. Various phenomena from special relativity are clearly…

Smith, Glenn S.

2011-01-01

118

Determination of the Magnetic Dipole Moment of the Rho Meson  

NASA Astrophysics Data System (ADS)

We determine the magnetic dipole moment of the rho meson using preliminary data from the BaBar Collaboration for the e+e- ? ?+?-2?0 process, in the center of mass energy range from 0.9 to 2.2 GeV. We describe the ?* ? 4? vertex using a vector meson dominance model, including all intermediate resonance contributions. We find that ?? = 2.1 ± 0.5 [e/2m?].

Toledo Sánchez, G.; García Gudiño, D.

2014-12-01

119

An Improved Experimental Limit on the Electric Dipole Moment of the Neutron  

E-print Network

An experimental search for an electric-dipole moment (EDM) of the neutron has been carried out at the Institut Laue-Langevin (ILL), Grenoble. Spurious signals from magnetic-field fluctuations were reduced to insignificance by the use of a cohabiting atomic-mercury magnetometer. Systematic uncertainties, including geometric-phase-induced false EDMs, have been carefully studied. Two independent approaches to the analysis have been adopted. The overall results may be interpreted as an upper limit on the absolute value of the neutron EDM of |d_n| < 2.9 x 10^{-26} e cm (90% CL).

C. A. Baker; D. D. Doyle; P. Geltenbort; K. Green; M. G. D. van der Grinten; P. G. Harris; P. Iaydjiev; S. N. Ivanov; D. J. R. May; J. M. Pendlebury; J. D. Richardson; D. Shiers; K. F. Smith

2006-09-28

120

Search for electric dipole moment in 129Xe atom using active nuclear spin maser  

NASA Astrophysics Data System (ADS)

An experimental search for an electric dipole moment in the diamagnetic atom 129Xe is in progress through the precision measurement of spin precession frequency using an active nuclear spin maser. A 3He comagnetometer has been incorporated into the active spin maser system in order to cancel out the long-term drifts in the external magnetic field. Also, a double-cell geometry has been adopted in order to suppress the frequency shifts due to interaction with polarized Rb atoms. The first EDM measurement with the 129Xe active spin maser and the 3He comagnetometer has been conducted.

Ichikawa, Y.; Chikamori, M.; Ohtomo, Y.; Hikota, E.; Sakamoto, Y.; Suzuki, T.; Bidinosti, C. P.; Inoue, T.; Furukawa, T.; Yoshimi, A.; Suzuki, K.; Nanao, T.; Miyatake, H.; Tsuchiya, M.; Yoshida, N.; Shirai, H.; Ino, T.; Ueno, H.; Matsuo, Y.; Fukuyama, T.; Asahi, K.

2014-03-01

121

Magnetic dipole super-resonances and their impact on mechanical forces at optical frequencies.  

PubMed

Artificial magnetism enables various transformative optical phenomena, including negative refraction, Fano resonances, and unconventional nanoantennas, beamshapers, polarization transformers and perfect absorbers, and enriches the collection of electromagnetic field control mechanisms at optical frequencies. We demonstrate that it is possible to excite a magnetic dipole super-resonance at optical frequencies by coating a silicon nanoparticle with a shell impregnated with active material. The resulting response is several orders of magnitude stronger than that generated by bare silicon nanoparticles and is comparable to electric dipole super-resonances excited in spaser-based nanolasers. Furthermore, this configuration enables an exceptional control over the optical forces exerted on the nanoparticle. It expedites huge pushing or pulling actions, as well as a total suppression of the force in both far-field and near-field scenarios. These effects empower advanced paradigms in electromagnetic manipulation and microscopy. PMID:24718235

Liberal, Iñigo; Ederra, Iñigo; Gonzalo, Ramón; Ziolkowski, Richard W

2014-04-01

122

General Magnetic Transition Dipole Moments for Electron Paramagnetic Resonance  

NASA Astrophysics Data System (ADS)

We present general expressions for the magnetic transition rates in electron paramagnetic resonance (EPR) experiments of anisotropic spin systems in the solid state. The expressions apply to general spin centers and arbitrary excitation geometry (Voigt, Faraday, and intermediate). They work for linear and circular polarized as well as unpolarized excitation, and for crystals and powders. The expressions are based on the concept of the (complex) magnetic transition dipole moment vector. Using the new theory, we determine the parities of ground and excited spin states of high-spin (S =5 /2 ) FeIII in hemin from the polarization dependence of experimental EPR line intensities.

Nehrkorn, Joscha; Schnegg, Alexander; Holldack, Karsten; Stoll, Stefan

2015-01-01

123

General magnetic transition dipole moments for electron paramagnetic resonance.  

PubMed

We present general expressions for the magnetic transition rates in electron paramagnetic resonance (EPR) experiments of anisotropic spin systems in the solid state. The expressions apply to general spin centers and arbitrary excitation geometry (Voigt, Faraday, and intermediate). They work for linear and circular polarized as well as unpolarized excitation, and for crystals and powders. The expressions are based on the concept of the (complex) magnetic transition dipole moment vector. Using the new theory, we determine the parities of ground and excited spin states of high-spin (S=5/2) Fe^{III} in hemin from the polarization dependence of experimental EPR line intensities. PMID:25615456

Nehrkorn, Joscha; Schnegg, Alexander; Holldack, Karsten; Stoll, Stefan

2015-01-01

124

SUPERCONDUCTING DIPOLE MAGNETS FOR THE LHC INSERTION REGIONS  

SciTech Connect

Dipole bending magnets are required to change the horizontal separation of the two beams in the LHC. In Intersection Regions (IR) 1, 2, 5, and 8, the beams are brought into collision for the experiments located there. In IR4, the separation of the beams is increased to accommodate the machine's particle acceleration hardware. As part of the US contribution to the LHC Project, BNL is building the required superconducting magnets. Designs have been developed featuring a single aperture cold mass in a single cryostat, two single aperture cold masses in a single cryostat, and a dual aperture cold mass in a single cryostat. All configurations feature the 80 mm diameter, 10 m long superconducting coil design used in the main bending magnets of the Relativistic Heavy Ion Collider recently completed at Brookhaven. The magnets for the LHC, to be built at Brookhaven, are described and results from the program to build two dual aperture prototypes are presented.

WILLEN,E.; ANERELLA,M.; COZZOLINO,J.; GANETIS,G.; GHOSH,A.; GUPTA,R.; HARRISON,M.; JAIN,A.; MARONE,A.; MURATORE,J.; PLATE,S.; SCHMALZLE,J.; WANDERER,P.; WU,K.C.

2000-06-26

125

A computationally compact representation of Magnetic-Apex and Quasi-Dipole coordinates with smooth base vectors  

Microsoft Academic Search

Many structural and dynamical features of the ionized and neutral upper atmosphere are strongly organized by the geomagnetic field, and several magnetic coordinate systems have been developed to exploit this organization. Quasi-Dipole coordinates are appropriate for calculations involving horizontally stratified phenomena like height-integrated currents, electron densities, and thermospheric winds; Modified Apex coordinates are appropriate for calculations involving electric fields and

J. T. Emmert; A. D. Richmond; D. P. Drob

2010-01-01

126

DIPOLE MAGNET FOR USE OF RHIC EBIS HEBT LINE Takeshi Kanesue, Kyushu University, Fukuoka 819-0395, Japan  

E-print Network

DIPOLE MAGNET FOR USE OF RHIC EBIS HEBT LINE Takeshi Kanesue, Kyushu University, Fukuoka 819 and magnetic field measurement of dipole magnets for RHIC-EBIS HEBT line have completed. These magnets the Booster ring in BNL. In this paper, overview of the magnetic design of the dipoles and results of magnetic

127

Improved limit on the muon electric dipole moment  

SciTech Connect

Three independent searches for an electric dipole moment (EDM) of the positive and negative muons have been performed, using spin precession data from the muon g-2 storage ring at Brookhaven National Laboratory. Details on the experimental apparatus and the three analyses are presented. Since the individual results on the positive and negative muons, as well as the combined result, d{sub {mu}}=(0.0{+-}0.9)x10{sup -19}e cm, are all consistent with zero, we set a new muon EDM limit, |d{sub {mu}}|<1.8x10{sup -19}e cm (95% C.L.). This represents a factor of 5 improvement over the previous best limit on the muon EDM.

Bennett, G. W.; Brown, H. N.; Bunce, G.; Danby, G. T.; Larsen, R.; Lee, Y. Y.; Meng, W.; Mi, J.; Morse, W. M.; Nikas, D.; Prigl, R.; Semertzidis, Y. K.; Warburton, D. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Bousquet, B.; Cushman, P.; Duong, L.; Giron, S.; Kindem, J.; Kronkvist, I.; Qian, T. [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States)] (and others)

2009-09-01

128

Nuclear Electric Dipole Moments in Chiral Effective Field Theory  

E-print Network

We provide the first consistent and complete calculation of the electric dipole moments of the deuteron, helion, and triton in the framework of chiral effective field theory. The CP-conserving and CP-violating interactions are treated on equal footing and we consider CP-violating one-, two-, and three-nucleon operators up to next-to-leading-order in the chiral power counting. In particular, we calculate for the first time EDM contributions induced by the CP-violating three-pion operator. We find that effects of CP-violating nucleon-nucleon contact interactions are larger than those found in previous studies based on phenomenological models for the CP-conserving nucleon-nucleon interactions. Our results are model-independent and can be used to test various scenarios of CP violation. As examples, we study the implications of our results on the QCD $\\theta$-term and the minimal left-right symmetric model.

J. Bsaisou; J. de Vries; C. Hanhart; S. Liebig; Ulf-G. Meißner; D. Minossi; A. Nogga; A. Wirzba

2014-11-21

129

Vol. 112 (2007) ACTA PHYSICA POLONICA A Supplement Electric Dipole Moments of Acetone  

E-print Network

Vol. 112 (2007) ACTA PHYSICA POLONICA A Supplement Electric Dipole Moments of Acetone and of Acetic Precise values for electric dipole moments of isolated acetone and acetic acid molecules were determined expansion. The new results are µtot = µb = 2.9345(22) D for acetone from measurements on the 111 101

Kisiel, Zbigniew

130

Dipole in a magnetic field, work, and quantum spin.  

PubMed

The behavior of an atom in a nonuniform magnetic field is analyzed, as well as the motion of a classical magnetic dipole (a spinning charged ball) and a rotating charged ring. For the atom it is shown that, while the magnetic field does no work on the electron-orbital contribution to the magnetic moment (the source of translational kinetic energy being the internal energy of the atom), whether or not it does work on the electron-spin contribution to the magnetic moment depends on whether the electron has an intrinsic rotational kinetic energy associated with its spin. A rotational kinetic energy for the electron is shown to be consistent with the Dirac equation. If the electron does have a rotational kinetic energy, the acceleration of a silver atom in a Stern-Gerlach experiment or the emission of a photon from an electron spin flip can be explained without requiring the magnetic field to do work. For a constant magnetic field gradient along the z axis, it is found that the classical objects oscillate in simple harmonic motion along the z axis, the total kinetic energy -- translational plus rotational -- being a constant of the motion. For the charged ball, the change in rotational kinetic energy is associated only with a change in the precession frequency, the rotation rate about the figure axis remaining constant. PMID:18517545

Deissler, Robert J

2008-03-01

131

Fabrication and test results of a high field, Nb3Sn superconducting racetrack dipole magnet  

SciTech Connect

The LBNL Superconducting Magnet Program is extending accelerator magnet technology to the highest possible fields. A 1 meter long, racetrack dipole magnet, utilizing state-of-the-art Nb{sub 3}Sn superconductor, has been built and tested. A record dipole filed of 14.7 Tesla has been achieved. Relevant features of the final assembly and tested results are discussed.

Benjegerdes, R.; Bish, P.; Byford, D.; Caspi, S.; Dietderich, D.R.; Gourlay, S.A.; Hafalia, R.; Hannaford, R.; Higley, H.; Jackson, A.; Lietzke, A.; Liggins, N.; McInturff, A.D.; O'Neill, J.; Palmerston, E.; Sabbi, G.; Scanlan, R.M.; Swanson, J.

2001-06-15

132

Communication: Theoretical study of ThO for the electron electric dipole moment search  

NASA Astrophysics Data System (ADS)

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H3?1 state of ThO molecule was proposed and now prepared by the ACME Collaboration [http://www.electronedm.org]. To interpret the experiment in terms of eEDM and dimensionless constant kT, P characterizing the strength of the T,P-odd pseudoscalar-scalar electron-nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, Eeff, and a parameter of the T,P-odd pseudoscalar-scalar interaction, WT, P, in ThO is required. We report our results for Eeff (84 GV/cm) and WT, P (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H3?1 ? X1?+ transition energy, which can serve as a measure of reliability of the obtained Eeff and WT, P values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the ?-doublets of H3?1.

Skripnikov, L. V.; Petrov, A. N.; Titov, A. V.

2013-12-01

133

Electric and Magnetic Field Detection in Elasmobranch Fishes  

NASA Astrophysics Data System (ADS)

Sharks, skates, and rays receive electrical information about the positions of their prey, the drift of ocean currents, and their magnetic compass headings. At sea, dogfish and blue sharks were observed to execute apparent feeding responses to dipole electric fields designed to mimic prey. In training experiments, stingrays showed the ability to orient relative to uniform electric fields similar to those produced by ocean currents. Voltage gradients of only 5 nanovolts per centimeter would elicit either behavior.

Kalmijn, Ad. J.

1982-11-01

134

Electric and magnetic field detection in elasmobranch fishes.  

PubMed

Sharks, skates, and rays receive electrical information about the positions of their prey, the drift of ocean currents, and their magnetic compass headings. At sea, dogfish and blue sharks were observed to execute apparent feeding responses to dipole electric fields designed to mimic prey. In training experiments, stingrays showed the ability to orient relative to uniform electric fields similar to those produced by ocean currents. Voltage gradients of only 5 nanovolts per centimeter would elicit either behavior. PMID:7134985

Kalmijn, A J

1982-11-26

135

Sensitivity of dipole magnetic tomography to magnetic nanoparticle injectates  

NASA Astrophysics Data System (ADS)

We compare the sensitivity of magnetic field measurements to perturbations of magnetic permeability with the field sensitivity to conductivity alterations. The conductivity perturbations can be caused by the different conductivity of the injected and formation resident fluid and the magnetic permeability perturbations by injecting magnetic nanoparticles. We devise a simple method for calculating the magnetic permeability sensitivity required to solve parametric inverse problems in electromagnetic (EM) tomography involving magnetic permeability perturbations. We apply the method in 3D and 2D axisymmetric to both crosswell and single-well configurations in a homogeneous background. The emphasis of this paper is on measurements acquired at very low induction numbers (kr ? 1; k being the wave number and r the distance) where the wave length or the skin depth becomes an irrelevant scale.

Rahmani, Amir Reza; Athey, Alex E.; Chen, Jiuping; Wilt, Michael J.

2014-04-01

136

Electric and Magnetic Interactions  

NSDL National Science Digital Library

This book offers a myriad of lessons, experiments, and demonstrations in all topics in the field of electricity and magnetism. From charge interactions to electromagnetic radiation and induction, it covers the material of a second semester calculus-based introductory physics course. This book is the second of two in the Matter & Interactions series. The Matter & Interactions series emphasizes that there are only a few fundamental principles that underlie the behavior of matter, and that it is possible to construct models that can explain and predict a wide variety of physical phenomena using these principles.

Chabay, Ruth; Sherwood, Bruce

2007-09-20

137

LABORATORY VI ELECTRICITY FROM MAGNETISM  

E-print Network

LABORATORY VI ELECTRICITY FROM MAGNETISM Lab VI - 1 In the previous problems you explored by electric currents. This lab will carry that investigation one step further, determining how changing magnetic fields can give rise to electric currents. This is the effect that allows the generation

Minnesota, University of

138

First experimental evidence of a giant permanent electric-dipole moment in cellulose nanocrystals  

NASA Astrophysics Data System (ADS)

The existence of a permanent electric dipole in cellulose nanocrystals (CNCs) has been evidenced by designed rectangular reversing pulse experiments. Transient electric birefringence (TEB) was used to measure the orientation under electric fields of CNCs dispersed in an apolar solvent (toluene) at low volume fraction. We probed the static and the dynamic orientational behaviour of CNCs in order to evaluate both the permanent and induced electric-dipole contributions to the orientational order parameter S2. We demonstrated the presence of a permanent dipole \\mu_p of about 4400+/-400 Debye along the CNCs long axis. The existence of this permanent dipole can stem from the parallel arrangement of cellulose chains in a non-centrosymmetric crystallographic lattice within each CNC together with the dipole moment borne by each glucosyl monomer.

Frka-Petesic, Bruno; Jean, Bruno; Heux, Laurent

2014-07-01

139

Self-consistent electric field-induced dipole interaction of colloidal spheres, cubes, rods, and dumbbells  

NASA Astrophysics Data System (ADS)

When calculating the interaction between electric field-induced dipoles, the dipole moments are often taken to be equal to their polarizability multiplied by the external electric field. However, this approach is not exact, since it does not take into account the fact that particles with a dipole moment affect the local electric field experienced by other particles. In this work, we employ the Coupled Dipole Method to calculate the electric-field-induced dipole pair interaction self-consistently: that is, we take into account many-body effects on the individual induced dipole moments. We calculate interactions of particles with nonvanishing dimensions by splitting them up into self-consistently inducible "chunks" of polarizable matter. For point dipoles, spheres, cubes, rods, and dumbbells, we discuss the differences and commonalities between our self-consistent approach and the aforementioned approach of pre-assigning dipole moments to either the point dipoles or, in the case of spatially extended particles, to the chunks making up the particle.

Kwaadgras, Bas W.; van Roij, René; Dijkstra, Marjolein

2014-04-01

140

Calculation of the neutron electric dipole moment with two dynamical flavors of domain wall fermions  

SciTech Connect

We present a study of the neutron electric dipole moment ({rvec d}{sub N}) within the framework of lattice QCD with two flavors of dynamical light quarks. The dipole moment is sensitive to the topological structure of the gauge fields, and accuracy can only be achieved by using dynamical, or sea quark, calculations. However, the topological charge evolves slowly in these calculations, leading to a relatively large uncertainty in {rvec d}{sub N}. It is shown, using quenched configurations, that a better sampling of the charge distribution reduces this problem, but because the CP even part of the fermion determinant is absent, both the topological charge distribution and {rvec d}{sub N} are pathological in the chiral limit. We discuss the statistical and systematic uncertainties arising from the topological charge distribution and unphysical size of the quark mass in our calculations and prospects for eliminating them. Our calculations employ the RBC collaboration two flavor domain wall fermion and DBW2 gauge action lattices with inverse lattice spacing a{sup -1} {approx} 1.7 GeV, physical volume V {approx} (2 fm){sup 3}, and light quark mass roughly equal to the strange quark mass (m{sub sea} = 0.03 and 0.04). We determine a value of the electric dipole moment that is zero within (statistical) errors, |{rvec d}{sub N}| = -0.04(20) e-{theta}-fm at the smaller sea quark mass. Satisfactory results for the magnetic and electric form factors of the proton and neutron are also obtained and presented.

F. Berruto; T. Blum; K. Orginos; A. Soni

2005-12-08

141

Acoustic dipole radiation based conductivity image reconstruction for magnetoacoustic tomography with magnetic induction  

NASA Astrophysics Data System (ADS)

Based on the acoustic dipole radiation theory, a tomograhic conductivity image reconstruction algorithm is developed for the magnetoacoustic tomography with magnetic induction (MAT-MI) in a cylindrical measurement configuration. It has been experimentally proved for a tissue-like phantom that not only the configuration but also the inner conductivity distribution can be reconstructed without any borderline stripe. Furthermore, the spatial resolution also can be improved without the limitation of acoustic vibration. The favorable results have provided solid verification for the feasibility of conductivity image reconstruction and suggested the potential applications of MAT-MI in the area of medical electrical impedance imaging.

Sun, Xiaodong; Zhang, Feng; Ma, Qingyu; Tu, Juan; Zhang, Dong

2012-01-01

142

Magnetic dipole moments of the145 149Eu ground states  

NASA Astrophysics Data System (ADS)

Nuclear orientation measurements at low temperatures have been carried out on radioactive isotopes of145 149Eu in Fe and of147,149Eu in Gd. The initial-state orientation coefficients determined from the measured gamma-ray anisotropies yield the magnetic dipole moments of the europium nuclei with A=145, 146, 147, 148 and 149 to be 3.2(5), 1.7(3), 3.1(4), 2.1(3) and 2.5(5), ?N, respectively. The values obtained for odd-A nuclei follow the systematics of the 5/2+ state magnetic moments of the nuclei in this region and are close to the values given by the single-particle model.

Kraciková, T. I.; Davaa, S.; Finger, M.; Deryuga, V. A.

1983-12-01

143

Coil end design for the LHC dipole magnet  

SciTech Connect

This paper describes the design of the coil ends for the Large Hadron Collider dipole magnets of the CERN European Laboratory for Particle Physics in Switzerland. This alternative to existing European designs was provided by Fermi National Accelerator Laboratory by agreement between CERN and the United States. The superconducting cable paths are determined from both magnetic and mechanical considerations. The coil end parts used to shape and constrain the conductors in the coil ends are designed using the developable surface, grouped end approach. This method allows the analysis of strain energy within the conductor groups, and the optimization of mechanical factors during the design. Design intent and implementation are discussed. Inner and outer coil design challenges and end analysis are detailed.

Brandt, J.S.

1996-05-21

144

Apparatus for Measurement of the Electric Dipole Moment of the Neutron using a Cohabiting Atomic-Mercury Magnetometer  

E-print Network

A description is presented of apparatus used to carry out an experimental search for an electric dipole moment of the neutron, at the Institut Laue-Langevin (ILL), Grenoble. The experiment incorporated a cohabiting atomic-mercury magnetometer in order to reduce spurious signals from magnetic field fluctuations. The result has been published in an earlier letter; here, the methods and equipment used are discussed in detail.

C. A. Baker; Y. Chibane; M. Chouder; P. Geltenbort; K. Green; P. G. Harris; B. R. Heckel; P. Iaydjiev; S. N. Ivanov; I. Kilvington; S. K. Lamoreaux; D. J. May; J. M. Pendlebury; J. D. Richardson; D. B. Shiers; K. F. Smith; M. van der Grinten

2013-06-05

145

Apparatus for Measurement of the Electric Dipole Moment of the Neutron using a Cohabiting Atomic-Mercury Magnetometer  

E-print Network

A description is presented of apparatus used to carry out an experimental search for an electric dipole moment of the neutron, at the Institut Laue-Langevin (ILL), Grenoble. The experiment incorporated a cohabiting atomic-mercury magnetometer in order to reduce spurious signals from magnetic field fluctuations. The result has been published in an earlier letter; here, the methods and equipment used are discussed in detail.

Baker, C A; Chouder, M; Geltenbort, P; Green, K; Harris, P G; Heckel, B R; Iaydjiev, P; Ivanov, S N; Kilvington, I; Lamoreaux, S K; May, D J; Pendlebury, J M; Richardson, J D; Shiers, D B; Smith, K F; van der Grinten, M

2013-01-01

146

Electric and Weak Electric Dipole Form Factors for Heavy Fermions in a General Two Higgs Doublet Model  

E-print Network

The electric and weak electric dipole form factors for heavy fermions are calculated in the context of the most general two-Higgs-doublet model (2HDM). We find that the large top mass can produce a significant enhancement of the electric dipole form factor in the case of the b and c quarks. This effect can be used to distinguish between different 2HDM scenarios.

Daniel Gomez-Dumm; G. A. Gonzalez-Sprinberg

1999-05-03

147

Generalized Wannier functions: A comparison of molecular electric dipole polarizabilities  

NASA Astrophysics Data System (ADS)

Localized Wannier functions provide an efficient and intuitive means by which to compute dielectric properties from first principles. They are most commonly constructed in a post-processing step, following total-energy minimization. Nonorthogonal generalized Wannier functions (NGWFs) [Skylaris , Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.66.035119 66, 035119 (2002); Skylaris , J. Chem. Phys.JCPSA60021-960610.1063/1.1839852 122, 084119 (2005)] may also be optimized in situ, in the process of solving for the ground-state density. We explore the relationship between NGWFs and orthonormal, maximally localized Wannier functions (MLWFs) [Marzari and Vanderbilt, Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.56.12847 56, 12847 (1997); Souza, Marzari, and Vanderbilt, Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.65.035109 65, 035109 (2001)], demonstrating that NGWFs may be used to compute electric dipole polarizabilities efficiently, with no necessity for post-processing optimization, and with an accuracy comparable to MLWFs.

O'Regan, David D.; Payne, Mike C.; Mostofi, Arash A.

2012-05-01

148

CP-odd phase correlations and electric dipole moments  

SciTech Connect

We revisit the constraints imposed by electric dipole moments (EDMs) of nucleons and heavy atoms on new CP-violating sources within supersymmetric theories. We point out that certain two-loop renormalization group corrections induce significant mixing between the basis-invariant CP-odd phases. In the framework of the constrained minimal supersymmetric standard model, the CP-odd invariant related to the soft trilinear A-phase at the grand unified theory (GUT) scale, {theta}{sub A}, induces nontrivial and distinct CP-odd phases for the three gaugino masses at the weak scale. The latter give one-loop contributions to EDMs enhanced by tan{beta}, and can provide the dominant contribution to the electron EDM induced by {theta}{sub A}. We perform a detailed analysis of the EDM constraints within the constrained minimal supersymmetric standard model, exhibiting the reach, in terms of sparticle spectra, which may be obtained assuming generic phases, as well as the limits on the CP-odd phases for some specific parameter points where detailed phenomenological studies are available. We also illustrate how this reach will expand with results from the next generation of experiments which are currently in development.

Olive, Keith A. [W.I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Pospelov, Maxim [Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2J 2W9 (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8P 1A1 (Canada); Ritz, Adam [Theoretical Division, Department of Physics, CERN, Geneva 23, CH-1211 (Switzerland); Santoso, Yudi [Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2J 2W9 (Canada)

2005-10-01

149

The molecular frame electric dipole moment and hyperfine interactions in hafnium fluoride, HfF.  

PubMed

The (1,0) [17.9]2.5-X(2)?(3?2) band of hafnium monofluoride (HfF) has been recorded using high-resolution laser-induced fluorescence spectroscopy both field-free and in the presence of a static electric field. The field-free spectra of (177)HfF, (179)HfF, and (180)HfF were modeled to generate a set of fine and hyperfine parameter for the X(2)?(3?2)(v = 0) and [17.9]2.5 (v = 1) states. The observed optical Stark shifts for the (180)HfF isotopologue were analyzed to produce the molecular frame electric dipole moments of 1.66(1) D and 0.419(7) D for the X(2)?(3?2) and [17.9]2.5 state, respectively. Both the generalized effective core potential and all-electron four component approaches were used in ab initio calculations to predict the properties of ground state HfF including equilibrium distance, dipole moments, quadrupole coupling, and magnetic hyperfine constants. PMID:23556729

Le, Anh; Steimle, Timothy C; Skripnikov, Leonid; Titov, Anatoly V

2013-03-28

150

Magnetic Testing of a Superferric Dipole That Uses Metal-Oxide Insulated CICC  

E-print Network

A small dipole magnet designed for use in high-radiation environments that uses metal-oxide cable-in-conduit-conductor has been constructed and tested for magnetic properties. The conductor consisted of 42 strands of 0.5 ...

DeLauter, Jonathan

151

Ramp-rate sensitivity of SSC dipole magnet prototypes  

SciTech Connect

One of the major achievements of the magnet R&D program for the Superconducting Super Collider (SSC) is the fabrication and test of a series of 20 5-cm aperture, 15-m long dipole magnet prototypes. The ramp rate sensitivity of these magnets appears to fall in at least two categories that can be correlated to the manufacturer and production batch of the strands used for the inner-coil cables. The first category, referred to as type-A, is characterized by a strong quench current degradation at high ramp rates, usually accompanied by large distortions of the multipole fields and large energy losses. The second category, referred to as type-B, is characterized by a sudden drop of quench current at low ramp rates, followed by a much milder degradation at larger rates. The multipole fields of the type-B magnets show little ramp-rate sensitivity, and the energy losses are smaller than for the type-A magnets. The behavior of the Type-A magnets can be explained in terms of inter-strand eddy currents arising from low and non-uniform resistances at the crossovers between the strands of the two-layer Rutherford-type cable. Anomalies in the transport-current repartition among the cable strands are suggested as a possible cause for the type-B behavior. The origins of these anomalies have not yet been clearly identified. The SSC project was canceled by decision of the United States Congress on October 21, 1994.

Devred, A.; Ogitsu, T.

1994-07-01

152

Temperature dependence of magnetic moments of nanoparticles and their dipole interaction in magnetic fluids  

NASA Astrophysics Data System (ADS)

Magnetic susceptibility measurements were carried out for magnetite-based fluids over a wide temperature range. The fluids were stabilized with commonly used surfactants (fatty acids) and new surfactants (polypropylene glycol and tallow acids). The coefficients of temperature dependence of the particle magnetic moments were determined by fitting of the measured and calculated values of magnetic susceptibility. The influence of the inter-particle dipole-dipole interaction on the susceptibility was taken into account in the framework of A.O. Ivanov's model. The corrections for thermal expansion were determined by density measurements of the carrier fluid. The obtained values of temperature coefficients correlate to the solidification temperature of the fluid samples. For fluids with a low solidification temperature the value of the temperature coefficient of particle magnetization coincides with its value for bulk magnetite.

Lebedev, A. V.

2015-01-01

153

Stable Divergence Angles of a Magnetic Dipole Spiral Array  

NASA Astrophysics Data System (ADS)

An analytical model is introduced for the experiment of Douady and Couder [Phys. Rev. Lett. 68, 2098 (1992), where phyllotactic patterns appear as a dynamical result of the interaction between magnetic dipoles. The difference equation for the divergence angle (i.e. the angle between successive radial vectors) is obtained by solving the equations of motion with a second nearest neighbor (SNN) approximation. A one-dimensional map analysis as well as a comprehensive analytical proof shows that the divergence angle always converges to a single attractor regardless of the initial conditions. This attractor is approximately the Fibonacci angle(~ 138°) within variations due to a growth factor ? of the pattern. The system is proved to be stable with the SNN approximation. Further analysis with a third nearest neighbor approximation (TNN) shows extra linearly stable attractors may appear around the Lucas angle (~ 99.5°).

Fan, X. D.; Bursill, L. A.

154

CryoEDM: A cryogenic experiment to measure the neutron electric dipole moment  

NASA Astrophysics Data System (ADS)

CryoEDM is an experiment that aims to measure the electric dipole moment (EDM) of the neutron to a precision of 10 -28 e cm. A description of CryoEDM, the apparatus, technologies and commissioning is presented.

van der Grinten, M. G. D.; CryoEDM Collaboration; Balashov, S. N.; Francis, V.; Green, K.; Iaydjiev, P. S.; Ivanov, S. N.; Khazov, A.; Tucker, M. A. H.; Wark, D. L.; Davidson, A.; Hardiman, M.; Harris, P. G.; Katsika, K.; Pendlebury, J. M.; Peeters, S. J. M.; Shiers, D. B.; Smith, P.; Townsley, C.; Wardell, I.; Clarke, C.; Henry, S.; Kraus, H.; McCann, M.; Geltenbort, P.; Yoshiki, Y.

2009-12-01

155

Application of Dipole-dipole, Induced Polarization, and CSAMT Electrical Methods to Detect Evidence of an Underground Nuclear Explosion  

NASA Astrophysics Data System (ADS)

There is little experience with application of electrical methods that can be applied during the continuation period of an on-site inspection (OSI), one of the verification methods of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). In order add to such experience, we conducted controlled source audiomagnetotelluric (CSAMT), dipole-dipole resistivity, and induced polarization electrical measurements along three survey lines over and near to ground zero of an historic nuclear explosion. The presentation will provide details and results of the surveys, an assessment of application of the method toward the purposes of an OSI, and an assessment of the manpower and time requirements for data collection and processing that will impact OSI inspection team operations. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Sweeney, J. J.; Felske, D.

2013-12-01

156

Low-energy electric dipole response of Sn isotopes  

E-print Network

We study the low-energy dipole (LED) strength distribution along the Sn isotopic chain in both the isoscalar (IS) and the isovector (IV, or E1) electric channels, to provide testable predictions and guidance for new experiments with stable targets and radioactive beams. We use the self-consistent Quasi-particle Random-Phase Approximation (QRPA) with finite-range interactions and mainly the Gogny D1S force. We analyze also the performance of a realistic two-body interaction supplemented by a phenomenological three-body contact term. We find that from N=50 and up to the N=82 shell closure (132Sn) the lowest-energy part of the IS-LED spectrum is dominated by a collective transition whose properties vary smoothly with neutron number and which cannot be interpreted as a neutron-skin oscillation. For the neutron-rich species this state contributes to the E1 strength below particle threshold, but much more E1 strength is carried by other, weak but numerous transitions around or above threshold. We find that strong structural changes in the spectrum take effect beyond N=82, namely increased LED strength and lower excitation energies. Our results with the Gogny interaction are compatible with existing data. On this basis we predict that a) the summed IS strength below particle threshold shall be of the same order of magnitude for N=50-82, b) the summed E1 strength up to approximately 12 MeV shall be similar for N=50-82 MeV, while c) the summed E1 strength below threshold shall be of the same order of magnitude for N ~ 64 - 82 and much weaker for the lighter, more-symmetric isotopes. We point out a general agreement of our results with other non-relativistic studies, the absence of a collective IS mode in some of those studies, and a possibly radical disagreement with relativistic models.

P. Papakonstantinou; H. Hergert; V. Yu. Ponomarev; R. Roth

2014-03-10

157

Theoretical Prediction and Impact of Fundamental Electric Dipole Moments  

E-print Network

The predicted Standard Model (SM) electric dipole moments (EDMs) of electrons and quarks are tiny, providing an important window to observe new physics. Theories beyond the SM typically allow relatively large EDMs. The EDMs depend on the relative phases of terms in the effective Lagrangian of the extended theory, which are generally unknown. Underlying theories, such as string/M-theories compactified to four dimensions, could predict the phases and thus EDMs in the resulting supersymmetric (SUSY) theory. Earlier one of us, with collaborators, made such a prediction and found, unexpectedly, that the phases were predicted to be zero at tree level in the theory at the unification or string scale $\\sim\\mathcal{O}(10^{16}$ GeV). Electroweak (EW) scale EDMs still arise via running from the high scale, and depend only on the SM Yukawa couplings that also give the CKM phase. Here we extend the earlier work by studying the dependence of the low scale EDMs on the constrained but not fully known fundamental Yukawa couplings. The dominant contribution is from two loop diagrams and is not sensitive to the choice of Yukawa texture. The electron EDM should not be found to be larger than about $ 5\\times 10^{-30} e$ cm, and the neutron EDM should not be larger than about $5\\times 10^{-29}e$ cm. These values are quite a bit smaller than the reported predictions from Split SUSY and typical effective theories, but much larger than the Standard Model prediction. Also, since models with random phases typically give much larger EDMs, it is a significant testable prediction of compactified M-theory that the EDMs should not be above these upper limits. The actual EDMs can be below the limits, so once they are measured they could provide new insight into the fundamental Yukawa couplings of leptons and quarks. We comment also on the role of strong CP violation. EDMs probe fundamental physics near the Planck scale.

Sebastian A. R. Ellis; Gordon L. Kane

2014-05-29

158

Neptune radio emission in dipole and multipole magnetic fields  

NASA Technical Reports Server (NTRS)

We study Neptune's smooth radio emission in two ways: we simulate the observations and we then consider the radio effects of Neptune's magnetic multipoles. A procedure to deduce the characteristics of radio sources observed by the Planetary Radio Astronomy experiment minimizes limiting assumptions and maximizes use of the data, including quantitative measurement of circular polarization. Study of specific sources simulates time variation of intensity and apparent polarization of their integrated emission over an extended time period. The method is applied to Neptune smooth recurrent emission (SRE). Time series are modeled with both broad and beamed emission patterns, and at two frequencies which exhibit different time variation of polarization. These dipole-based results are overturned by consideration of more complex models of Neptune's magnetic field. Any smooth emission from the anticipated auroral radio source is weak and briefly observed. Dominant SRE originates complex fields at midlatitude. Possible SRE source locations overlap that of 'high-latitude' emission (HLE) between +(out) and -(in) quadrupoles. This is the first identification of multipolar magnetic structure with a major source of planetary radio emission.

Sawyer, C. B.; King, N. V.; Romig, J. H.; Warwick, J. W.

1995-01-01

159

ANALYTICAL CALCULATION OF STOKES PROFILES OF ROTATING STELLAR MAGNETIC DIPOLE  

SciTech Connect

The observation of the polarization emerging from a rotating star at different phases opens up the possibility to map the magnetic field in the stellar surface thanks to the well-known Zeeman-Doppler imaging. When the magnetic field is sufficiently weak, the circular and linear polarization profiles locally in each point of the star are proportional to the first and second derivatives of the unperturbed intensity profile, respectively. We show that the weak-field approximation (for weak lines in the case of linear polarization) can be generalized to the case of a rotating star including the Doppler effect and taking into account the integration on the stellar surface. The Stokes profiles are written as a linear combination of wavelength-dependent terms expressed as series expansions in terms of Hermite polynomials. These terms contain the surface-integrated magnetic field and velocity components. The direct numerical evaluation of these quantities is limited to rotation velocities not larger than eight times the Doppler width of the local absorption profiles. Additionally, we demonstrate that in a rotating star, the circular polarization flux depends on the derivative of the intensity flux with respect to the wavelength and also on the profile itself. Likewise, the linear polarization depends on the profile and on its first and second derivatives with respect to the wavelength. We particularize the general expressions to a rotating dipole.

Martinez Gonzalez, M. J. [Instituto de Astrofisica de Canarias, Via Lactea s/n, 38200 La Laguna, Tenerife (Spain); Asensio Ramos, A. [Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife (Spain)

2012-08-20

160

Magnetic field measurements of 1. 5 meter model SSC collider dipole magnets at Fermilab  

SciTech Connect

Magnetic field measurements have been performed at Fermilab on 1.5 m magnetic length model dipoles for the Superconducting Supercollider. Harmonic measurements are recorded at room temperature before and after the collared coil is assembled into the yoke and at liquid helium temperature. Measurements are made as a function of longitudinal position and excitation current. High field data are compared with room temperature measurements of both the collared coil and the completed yoked magnet and with the predicted fields for both the body of the magnet and the coil ends.

Lamm, M.J.; Bleadon, M.; Coulter, K.J.; Delchamps, S.; Hanft, R.; Jaffery, T.S.; Kinney, W.; Koska, W.; Ozelis, J.P.; Strait, J.; Wake, M. (Fermi National Accelerator Lab., Batavia, IL (United States)); DiMarco, J. (Superconducting Super Collider Lab., Dallas, TX (United States))

1991-09-01

161

Trapped ion emulation of electric dipole moment of neutral relativistic particles  

E-print Network

The electric dipole moments of various neutral elementary particles, such as neutron, neutrinos, certain hypothetical dark matter particles and others, are predicted to exist by the standard model of high energy physics and various extensions of it. However, the predicted values are beyond the present experimental capabilities. We propose to simulate and emulate the electric dipole moment of neutral relativistic particles and the ensuing effects in the presence of electrostatic field by emulation of an extended Dirac equation in ion traps.

Tihomir G. Tenev; Peter A. Ivanov; Nikolay V. Vitanov

2012-09-06

162

Proposal for trapped-ion emulation of the electric dipole moment of neutral relativistic particles  

NASA Astrophysics Data System (ADS)

The electric dipole moments of various neutral elementary particles, such as neutron, neutrinos, certain hypothetical dark matter particles, and others, are predicted to exist by the standard model of high-energy physics and various extensions of it. However, the predicted values are beyond the present experimental capabilities. We propose to simulate and emulate the electric dipole moment of neutral relativistic particles and the ensuing effects in the presence of an electrostatic field by emulation of an extended Dirac equation in ion traps.

Tenev, Tihomir G.; Ivanov, Peter A.; Vitanov, Nikolay V.

2013-02-01

163

Electrically active magnetic excitations in antiferromagnets (Review Article)  

NASA Astrophysics Data System (ADS)

Operating magnetic resonance by an electric field is a highly nontrivial concept, but is the most demanding function in the future of spin-electronics. Recent observations in a variety of multiferroic materials, named `collective electrically active magnetic excitations' and frequently referred to as "electromagnons," reveal a possibility of implementing such a function. Experimental advances in terahertz spectroscopy of electromagnons in multiferroics, as well as related theoretical models, are reviewed. Earlier theoretical works, where the existence of electric-dipole-active magnetic excitations in antiferro- and ferrimagnets with collinear spin structure has been predicted, are also discussed. Multi-sublattice magnets with electrically active magnetic excitations at room temperature provide a direct opportunity to transform one type of excitation into another in a terahertz time-domain. This is of crucial importance for magnon-based spintronics, since only short-wavelength exchange magnons allow signal processing at nanoscale distances.

Krivoruchko, V. N.

2012-09-01

164

Coherent dipole-dipole coupling between two single Rydberg atoms at an electrically-tuned Förster resonance  

NASA Astrophysics Data System (ADS)

Resonant energy transfers, the non-radiative redistribution of an electronic excitation between two particles coupled by the dipole-dipole interaction, lie at the heart of a variety of phenomena, notably photosynthesis. In 1948, Förster established the theory of fluorescence resonant energy transfer (FRET) between broadband, nearly-resonant donors and acceptors. The 1/R6 scaling of the energy transfer rate, where R is the distance between particles, enabled widespread use of FRET as a `spectroscopic ruler’ for determining nanometric distances in biomolecules. The underlying mechanism is a coherent dipolar coupling between particles, as recognized in the early days of quantum mechanics, but this coherence has not been directly observed so far. Here we study, spectroscopically and in the time domain, the coherent, dipolar-induced exchange of excitations between two Rydberg atoms separated by up to 15 ?m, and brought into resonance by applying an electric field. Coherent oscillation of the system between two degenerate pair states then occurs at a frequency scaling as 1/R3, the hallmark of resonant dipole-dipole interactions. Our results not only demonstrate, at the fundamental level of two atoms, the basic mechanism underlying FRET, but also open exciting prospects for active tuning of strong, coherent interactions in quantum many-body systems.

Ravets, Sylvain; Labuhn, Henning; Barredo, Daniel; Béguin, Lucas; Lahaye, Thierry; Browaeys, Antoine

2014-12-01

165

IMPROVING STUDENTS’ UNDERSTANDING OF ELECTRICITY AND MAGNETISM.  

E-print Network

??Electricity and magnetism are important topics in physics. Research shows that students have many common difficulties in understanding concepts related to electricity and magnetism. However,… (more)

Li, Jing

2012-01-01

166

MAGNETIC FIELD MEASUREMENTS OF HD2, A HIgh Nb3Sn DIPOLE MAGNET  

SciTech Connect

The Superconducting Magnet Program at Lawrence Berkeley National Laboratory has designed and tested HD2, a 1 m long Nb{sub 3}Sn accelerator-type dipole based on a simple block-type coil geometry with flared ends. HD2 represents a step toward the development of cost-effective accelerator quality magnets operating in the range of 13-15 T. The design was optimized to minimize geometric harmonics and to address iron saturation and conductor magnetization effects. Field quality was measured during recent cold tests. The measured harmonics are presented and compared to the design values.

Wang, X.; Caspi, S.; Cheng, D. W.; Felice, H.; Ferracin, P.; Hafalia, R. R.; Joseph, J. M.; Lietzke, A. F.; Lizarazo, J.; McInturff, A. D.; Sabbi, G. L.; Sasaki, K.

2009-05-04

167

Molecular Expressions: Electricity and Magnetism  

NSDL National Science Digital Library

This is a collection of introductory tutorials and interactive simulations pertaining to electricity and magnetism. The resources are appropriate for beginners and non-science majors, covering topics that include capacitance, inductance, resistance, batteries, generators and motors, and biographical histories of pioneers in electromagnetism. Tutorials are paired with interactive Java simulations designed to enhance understanding of the physics relating to devices such as transformers, AC and DC generators, computer hard drives, pulse magnets, transistors, and more. This item is part of a larger collection of materials on optics, microscopy, electricity, and magnetism developed by the National High Magnetic Field Laboratory and Florida State University.

Davidson, Michael

2010-03-16

168

Solar rotating magnetic dipole?. [around axis perpendicular to rotation axis of the sun  

NASA Technical Reports Server (NTRS)

A magnetic dipole rotating around an axis perpendicular to the rotation axis of the sun can account for the characteristics of the surface large-scale solar magnetic fields through the solar cycle. The polarity patterns of the interplanetary magnetic field, predictable from this model, agree with the observed interplanetary magnetic sector structure.

Antonucci, E.

1974-01-01

169

Impact of motion along the field direction on geometric-phase-induced false electric dipole moment signals  

E-print Network

Geometric-phase-induced false electric dipole moment (EDM) signals, resulting from interference between magnetic field gradients and particle motion in electric fields, have been studied extensively in the literature, especially for neutron EDM experiments utilizing stored ultracold neutrons and co-magnetometer atoms. Previous studies have considered particle motion in the transverse plane perpendicular to the direction of the applied electric and magnetic fields. We show, via Monte Carlo studies, that motion along the field direction can impact the magnitude of this false EDM signal if the wall surfaces are rough such that the wall collisions can be modeled as diffuse, with the results dependent on the size of the storage cell's dimension along the field direction.

H. Yan; B. Plaster

2011-04-07

170

Self-force on an electric dipole in the spacetime of a cosmic string  

SciTech Connect

We calculate the electrostatic self-force on an electric dipole in the spacetime generated by a static, thin, infinite and straight cosmic string. The electric dipole is held fixed in different configurations, namely, parallel, perpendicular to the cosmic string and oriented along the azimuthal direction around this topological defect, which is stretched along the z axis. We show that the self-force is equivalent to an interaction of the electric dipole with an effective dipole moment which depends on the linear mass density of the cosmic string and on the configuration. The plots of the self-forces as functions of the parameter which determines the angular deficit of the cosmic string are shown for those different configurations. -- Highlights: •Review of regularized Green’s function applied to the problem. •Self-force on an electric dipole in the string spacetime for some orientations. •Representation via graphs of the self-forces versus angular parameter of the cosmic string. •Self-force induced by the string seen as an interaction between two dipoles. •Discussion about the superposition principle in this non-trivial background.

Muniz, C.R., E-mail: celiomuniz@yahoo.com [Grupo de Física Teórica (GFT), Universidade Estadual do Ceará, UECE-FECLI, Iguatu, Ceará (Brazil); Bezerra, V.B., E-mail: valdir@ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, CEP 58051-970, João Pessoa, PB (Brazil)

2014-01-15

171

Electrodynamic Coupling of Electric Dipole Emitters to a Fluctuating Mode Density within a Nanocavity  

NASA Astrophysics Data System (ADS)

We investigate the impact of rotational diffusion on the electrodynamic coupling of fluorescent dye molecules (oscillating electric dipoles) to a tunable planar metallic nanocavity. Fast rotational diffusion of the molecules leads to a rapidly fluctuating mode density of the electromagnetic field along the molecules’ dipole axis, which significantly changes their coupling to the field as compared to the opposite limit of fixed dipole orientation. We derive a theoretical treatment of the problem and present experimental results for rhodamine 6G molecules in cavities filled with low and high viscosity liquids. The derived theory and presented experimental method is a powerful tool for determining absolute quantum yield values of fluorescence.

Chizhik, Alexey I.; Gregor, Ingo; Schleifenbaum, Frank; Müller, Claus B.; Röling, Christian; Meixner, Alfred J.; Enderlein, Jörg

2012-04-01

172

Electric dipole fields over a quarter space earth inhomogeneity and application ice hazard detection  

Microsoft Academic Search

An analysis of the fields generated by an electric dipole over a quarter space earth inhomogeneity is carried out. The results of this analysis have a particular application to the long-range detection of ice hazards, such as multiyear ice, pressure ridges and icebergs. The analysis is based on a method of space and electric field decomposition in which Heaviside functions

J. Ryan; J. Walsh

1985-01-01

173

Direct detection of light anapole and magnetic dipole DM  

NASA Astrophysics Data System (ADS)

We present comparisons of direct detection data for ``light WIMPs'' with an anapole moment interaction (ADM) and a magnetic dipole moment interaction (MDM), both assuming the Standard Halo Model (SHM) for the dark halo of our galaxy and in a halo-independent manner. In the SHM analysis we find that a combination of the 90% CL LUX and CDMSlite limits or the new 90% CL SuperCDMS limit by itself exclude the parameter space regions allowed by DAMA, CoGeNT and CDMS-II-Si data for both ADM and MDM. In our halo-independent analysis the new LUX bound excludes the same potential signal regions as the previous XENON100 bound. Much of the remaining signal regions is now excluded by SuperCDMS, while the CDMSlite limit is much above them. The situation is of strong tension between the positive and negative search results both for ADM and MDM. We also clarify the confusion in the literature about the ADM scattering cross section.

Del Nobile, Eugenio; Gelmini, Graciela B.; Gondolo, Paolo; Huh, Ji-Haeng

2014-06-01

174

Heat leak testing of a superconducting RHIC dipole magnet at Brookhaven National Laboratory  

SciTech Connect

Brookhaven National Laboratory is currently performing heat load tests on a superconducting dipole magnet. The magnet is a prototype of the 360, 8 cm bore, arc dipole magnets that will be used in the Relativistic Heavy Ion Collider (RMC). An accurate measurement of the heat load is needed to eliminate cumulative errors when determining the REUC cryogenic system load requirements. The test setup consists of a dipole positioned between two quadrupoles in a common vacuum tank and heat shield. Piping and instrumentation are arranged to facilitate measurement of the heat load on the primary 4.6 K magnet load and the secondary 55 K heat shield load. Initial results suggest that the primary heat load is well below design allowances. The secondary load was found to be higher than estimated, but remained close to the budgeted amount. Overall, the dipole performed to specifications.

DeLalio, J.T.; Brown, D.P.; Sondericker, J.H.

1993-09-01

175

Dynamics of a vortex dipole across a magnetic phase boundary in a spinor Bose-Einstein condensate  

NASA Astrophysics Data System (ADS)

The dynamics of a vortex dipole in a spin-1 Bose-Einstein condensate in which magnetic phases are spatially distributed is investigated. When a vortex dipole travels from the ferromagnetic phase to the polar phase, or vice versa, it penetrates the phase boundary and transforms into one of the various spin vortex dipoles, such as a leapfrogging ferromagnetic-core vortex dipole and a half-quantum vortex dipole. Topological connections of spin wave functions across the phase boundary are discussed.

Kaneda, Tomoya; Saito, Hiroki

2014-11-01

176

Self-energy anomaly of an electric pointlike dipole in three-dimensional static spacetimes  

E-print Network

We calculate the self-energy anomaly of a pointlike electric dipole located in a static $(2+1)$-dimensional curved spacetime. The energy functional for this problem is invariant under an infinite-dimensional (gauge) group of transformations parameterized by one scalar function of two variables. We demonstrate that the problem of the calculation of the self-energy anomaly for a pointlike dipole can be reduced to the calculation of quantum fluctuations of an effective two-dimensional Euclidean quantum field theory. We reduced the problem in question to the calculation of the conformal anomaly of an effective scalar field in two dimensions and obtained an explicit expression for the self-energy anomaly of an electric dipole in an asymptotically flat, regular $(2+1)$-dimensional spacetime which may have electrically neutral black-hole-like metrics with regular Killing horizon.

Valeri P. Frolov; Andrey A. Shoom; Andrei Zelnikov

2013-03-07

177

Unraveling models of CP violation through electric dipole moments of light nuclei  

E-print Network

We show that the proposed measurements of the electric dipole moments of light nuclei in storage rings would put strong constraints on models of flavor-diagonal CP violation. Our analysis is exemplified by a comparison of the Standard Model including the QCD theta term, the minimal left-right symmetric model, a specific version of the so-called aligned two-Higgs doublet model, and briefly the minimal supersymmetric extension of the Standard Model. By using effective field theory techniques we demonstrate to what extend measurements of the electric dipole moments of the nucleons, the deuteron, and helion could discriminate between these scenarios. We discuss how measurements of electric dipole moments of other systems relate to the light-nuclear measurements.

W. Dekens; J. de Vries; J. Bsaisou; W. Bernreuther; C. Hanhart; Ulf-G. Meißner; A. Nogga; A. Wirzba

2014-07-21

178

Proposed search for an electric-dipole moment using laser-cooled 171Yb atoms  

NASA Astrophysics Data System (ADS)

We propose an experiment to search for a permanent atomic electric-dipole moment (EDM) using laser-cooled 171Yb atoms launched in an atomic fountain. A uniform B field sets the quantization axis, and the Ramsey separated-oscillatory-fields method is used to measure the Zeeman precession frequency of the atoms. Laser beams of appropriate polarization are used for preparation and detection in a given magnetic sublevel. The signature of an EDM is a shift in the Ramsey resonance correlated with application of a large E field. The precision is expected to be at least 20 times better than current limits because the use of a cold atomic beam allows application of E field 10 times larger than in a vapor cell, and the interaction time with the E field is 200 times larger compared to a thermal beam. The leading source of systematic error in beam experiments, the {E} × {v}/c motional magnetic field, is reduced considerably because of the near-perfect reversal of velocity between up and down trajectories through the E-field region.

Natarajan, V.

2005-01-01

179

Electric and Magnetic Forces  

NSDL National Science Digital Library

SciGuides are a collection of thematically aligned lesson plans, simulations, and web-based resources for teachers to use with their students centered on standards-aligned science concepts. People have known about and experienced electricity an

2010-02-10

180

Magnetohydrodynamic Simulations of Hypersonic Flow over a Cylinder Using Axial- and Transverse-Oriented Magnetic Dipoles  

PubMed Central

Numerical simulations of magnetohydrodynamic (MHD) hypersonic flow over a cylinder are presented for axial- and transverse-oriented dipoles with different strengths. ANSYS CFX is used to carry out calculations for steady, laminar flows at a Mach number of 6.1, with a model for electrical conductivity as a function of temperature and pressure. The low magnetic Reynolds number (?1) calculated based on the velocity and length scales in this problem justifies the quasistatic approximation, which assumes negligible effect of velocity on magnetic fields. Therefore, the governing equations employed in the simulations are the compressible Navier-Stokes and the energy equations with MHD-related source terms such as Lorentz force and Joule dissipation. The results demonstrate the ability of the magnetic field to affect the flowfield around the cylinder, which results in an increase in shock stand-off distance and reduction in overall temperature. Also, it is observed that there is a noticeable decrease in drag with the addition of the magnetic field. PMID:24307870

Guarendi, Andrew N.; Chandy, Abhilash J.

2013-01-01

181

Charge non-conservation, dequantisation, and induced electric dipole moments in varying-alpha theories  

E-print Network

We note that in extensions of the Standard Model that allow for a varying fine structure constant, alpha, all matter species, apart from right-handed neutrinos, will gain an intrinsic electric dipole moment (EDM). In a large subset of varying-alpha theories, all such particle species will also gain an effective electric charge. This charge will in general not be quantised and can result in macroscopic non-conservation of electric charge.

Douglas J. Shaw

2005-09-13

182

Electric dipole response of {sup 208}Pb and constraints on the symmetry energy  

SciTech Connect

The electric dipole (E1) response of {sup 208}Pb has been precisely determined by measuring polarized proton inelastic scattering at very forward angles including zero degrees. The electric dipole polarizability, that is defined as the inverse energy-weighted sum rule of the E1 reduced transition strength, has been extracted as ?{sub D} = 20.1 ±0.6 fm{sup 3}. A constraint band has been extracted in the plane of the symmetry energy (J) and its slope parameter (L) at the saturation density.

Tamii, A. [Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka, Ibaraki 567-0047 (Japan)

2014-05-02

183

P- and T-Violating Lagrangians in Chiral Effective Field Theory and Nuclear Electric Dipole Moments  

E-print Network

A scheme to derive hadronic interactions induced by effective multi-quark terms is presented within the framework of chiral effective field theory. It is employed to work out the list of parity- and time-reversal-symmetry-violating hadronic interactions that are relevant for the computation of nuclear contributions to the electric dipole moments of the hydrogen-2, helium-3 and hydrogen-3 nuclei. We also derive the scattering and Faddeev equations required to compute electromagnetic form factors in general and electric dipole moments in particular.

Bsaisou, J; Nogga, A; Wirzba, A

2014-01-01

184

Energy levels and strong electric dipole transitions in magnesium-like gold  

NASA Astrophysics Data System (ADS)

We have reported the energy levels and strong electric dipole transition parameters such as wavelengths, weighted oscillator strengths and transition rates (or probabilities) in magnesium-like gold (Au67+, Z=79) using AUTOSTRUCTURE atomic code. Recently reported data for heavy Au ions and Au plasma diagnostics are important, in particular for modeling of M-shell spectra of Au ions. In calculations, we have considered the correlation, relativistic and quantum electrodynamics effects. The obtained results have been compared with those from other works. All lines obtained from electric dipole transitions have been also presented.

Konan, Gülay Günday; Özdemir, Leyla; Ürer, Güldem

2014-09-01

185

Ground State of Magnetic Dipoles on a Two-Dimensional Lattice: Structural Phases in Complex Plasmas  

SciTech Connect

We study analytically and by molecular dynamics simulations the ground state configuration of a system of magnetic dipoles fixed on a two-dimensional lattice. We find different phases, in close agreement with previous results. Building on this result and on the minimum energy requirement we determine the equilibrium lattice configuration, the magnetic order (ferromagnetic versus antiferromagnetic), and the magnetic polarization direction of a system of charged mesoscopic particles with magnetic dipole moments, in the domain where the strong electrostatic coupling leads to a crystalline ground state. Orders of magnitudes of the parameters of the system relevant to possible future dusty plasma experiments are discussed.

Feldmann, J. D.; Kalman, G. J. [Department of Physics, Boston College, 140 Commonwealth Avenue, Chestnut Hill, Massachusetts, 02467 (United States); Hartmann, P. [Research Institute for Solid State Physics and Optics of the Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Rosenberg, M. [Department of Electrical and Computer Engineering, University of California-San Diego, La Jolla, California, 92093 (United States)

2008-02-29

186

Brief Electricity and Magnetism Assessment  

NSDL National Science Digital Library

The Brief Electricity and Magnetism Assessment (BEMA), developed by Chabay and Sherwood, assesses student understanding of basic electricity and magnetism concepts. It is written for college-level calculus-based introductory physics courses. The files are password protected; users who wish to access the assessment will need to contact the authors. A Spanish translation of BEMA is available under Supplemental Documents. The reliability and discriminatory power of this assessment tool have been tested. The results are available at: Physical Review Special Topics - Physics Education Research: Volume 2, Issue 1, Page 7, http://prst-per.aps.org/abstract/PRSTPER/v2/i1/e010105

Chabay, Ruth; Sherwood, Bruce

2006-06-15

187

Interpretation of dipole-dipole electrical resistivity survey, Colado geothermal area, Pershing County, Nevada  

Microsoft Academic Search

An electrical resistivity survey in the Colado geothermal area, Pershing County, Nevada has defined areas of low resistivity on each of five lines surveyed. Some of these areas appear to be fault controlled. Thermal fluids encountered in several drill holes support the assumption that the hot fluids may be associated with areas of low resistivity. The evidence of faulting as

C. E. Mackelprang

1980-01-01

188

Polarity reversals and tilt of the Earth's magnetic dipole  

NASA Technical Reports Server (NTRS)

There is evidence that the terrestrial magnetic field is connected with the Earth's mantle: (1) there are magnetic anomalies that do not take part in the westward drift of the main field, but are fixed with respect to the mantle; (2) the geomagnetic pole position flips in a particular way by preferred meridional paths during a reversal; and (3) magnetic polarity reversals are correlated with the activations of geological processes. These facts may be explained if we take into account that a significant horizontal temperature gradient can exist in the top levels of the liquid core because of the different thermoconductivity of the different areas of the core-mantle boundary. These temperature inhomogeneities can penetrate the core because fluxes along the core boundary (the thermal wind) can be strongly suppressed by a small redistribution of the chemical composition in the top of the core. The nonparallel gradients of the temperature, density, and composition on the top of the core create a curled electric field that produces a current and a magnetic field. This seed-field can be amplified by motions in the core. The resulting field does not forget the seed-field distribution and in this way the field on the Earth surface (that can be created only in regions with high conductivity, i.e. in the core) is connected with the core-mantle boundary. Contrary to the usual approach to the dynamo problem, we will take into account that the seed field of thermoelectric origin is acting not only at some initial moment of time but permanently.

Dolginov, A. Z.

1993-01-01

189

Physics Topics: Electricity and Magnetism  

NSDL National Science Digital Library

This item is a section of an introductory physics textbook. It provides content support on electrostatics, electric field and potential, current electricity, magnetic field and force, and electromagnetic phenomena. The author, a veteran professor of physics, has summarized his own notes from "lectures that worked" and blended them with calculus-based practice problems with solutions. It is designed to supplement teachers and learners who have mastered basic concepts but need support with calculus-based operations and differential equations.

Tatum, J. B.

2006-11-14

190

Reversals of the solar magnetic dipole in the light of observational data and simple dynamo models  

NASA Astrophysics Data System (ADS)

Context. Observations show that the photospheric solar magnetic dipole usually does not vanish during the reversal of the solar magnetic field, which occurs in each solar cycle. In contrast, mean-field solar dynamo models predict that the dipole field does become zero. In a recent paper it was suggested that this contradiction could be explained as a large-scale manifestation of small-scale magnetic fluctuations of the surface poloidal field. Aims: Our aim is to confront this interpretation with the available observational data. Methods: Here we compare this interpretation with Wilcox Solar Observatory (WSO) photospheric magnetic field data in order to determine the amplitude of magnetic fluctuations required to explain the phenomenon and to compare the results with predictions from a simple dynamo model which takes these fluctuations into account. Results: We demonstrate that the WSO data concerning the magnetic dipole reversals are very similar to the predictions from our very simple solar dynamo model, which includes both mean magnetic field and fluctuations. The ratio between the rms value of the magnetic fluctuations and the mean field is estimated to be about 2, in reasonable agreement with estimates from sunspot data. The reversal epoch, during which the fluctuating contribution to the dipole is larger than that from the mean field, is about 4 months. The memory time of the fluctuations is about 2 months. Observations demonstrate that the rms of the magnetic fluctuations is strongly modulated by the phase of the solar cycle. This gives additional support to the concept that the solar magnetic field is generated by a single dynamo mechanism rather than also by independent small-scale dynamo action. A suggestion of a weak nonaxisymmetric magnetic field of a fluctuating nature arises from the analysis, with a lifetime of about 1 year. Conclusions: The behaviour of the magnetic dipole during the reversal epoch gives valuable information about details of solar dynamo action.

Pipin, V. V.; Moss, D.; Sokoloff, D.; Hoeksema, J. T.

2014-07-01

191

Schiff Theorem and the Electric Dipole Moments of Hydrogen-Like Atoms  

SciTech Connect

The Schiff theorem is revisited in this work and the residual P- and T-odd electron-nucleus interaction, after the shielding takes effect, is completely specified. An application is made to the electric dipole moments of hydrogen-like atoms, whose qualitative features and systematics have important implication for realistic paramagnetic atoms.

Liu, C.-P. [Kernfysisch Versneller Instituut, Zernikelaan 25, 9747 AA Groningen (Netherlands); Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Haxton, W. C. [INT, Univ. of Washington, Box 351550, Seattle, WA 98195-1550 (United States); Dept. of Physics, Univ. of Washington, Box 351550, Seattle, WA 98195-1550 (United States); Ramsey-Musolf, M. J. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Timmermans, R. G. E.; Dieperink, A. E. L. [Kernfysisch Versneller Instituut, Zernikelaan 25, 9747 AA Groningen (Netherlands)

2006-07-11

192

Schiff Theorem and the Electric Dipole Moments of Hydrogen-Like Atoms  

E-print Network

The Schiff theorem is revisited in this work and the residual $P$- and $T$-odd electron--nucleus interaction, after the shielding takes effect, is completely specified. An application is made to the electric dipole moments of hydrogen-like atoms, whose qualitative features and systematics have important implication for realistic paramagnetic atoms.

C. -P. Liu; W. C. Haxton; M. J. Ramsey-Musolf; R. G. E. Timmermans; A. E. L. Dieperink

2006-01-09

193

Dipole and electric quadrupole excitations in 32S up to 9.9 MeV  

NASA Astrophysics Data System (ADS)

Real photon scattering experiments have been performed on the N=Z nucleus 32S to investigate energies and absolute strengths of dipole and electric quadrupole excitations up to a maximum energy of Ex=9.9 MeV. Evidence for a 2+?3- two-phonon state, which is well established in heavier nuclei, is discussed.

Babilon, M.; Hartmann, T.; Mohr, P.; Vogt, K.; Volz, S.; Zilges, A.

2002-03-01

194

Fluid simulation of the collisionless plasma sheath surrounding an electric dipole antenna in the inner magnetosphere  

Microsoft Academic Search

The electrostatic sheath formation surrounding an electric dipole antenna at very low frequencies (VLF) in a magnetoplasma is examined through numerical simulation. In this paper, a hydrodynamic approach is used to solve for the nonlinear sheath dynamics of antennas located in plasmas similar to that which exists in the plasmasphere between L = 2 and L = 3 in the

T. W. Chevalier; T. F. Bell

2010-01-01

195

A unified theory on radiation of a vertical electric dipole above a dissipative earth  

Microsoft Academic Search

Analytical expressions are derived for the electromagnetic field associated with a vertical electric dipole above a dissipative earth. The scattered field is shown to consist of a direct contribution from a perfect image source, and a correction due to the finite conductivity of earth which is expressible in terms of an incomplete Hankel function. The resultant expression readily reduces to

D. C. Chang; R. J. Fisher

1974-01-01

196

Transient electromagnetic field generated by a vertical electric dipole on the surface of a dissipative earth  

Microsoft Academic Search

The problem of electromagnetic pulse propagation over a dissipative earth surface, excited by a vertical electric dipole located on the earth surface, is investigated. By deforming related integrals in the complex frequency domain it is shown that the scattering contribution of the earth, which is formally expressed in terms of several double inf'mite integrals, can be efficiently computed from some

Hussain Haddad; D. C. Chang

1981-01-01

197

Power loss of an oscillating electric dipole in a quantum plasma  

SciTech Connect

A system of linearized quantum plasma equations (quantum hydrodynamic model) has been used for investigating the dispersion equation for electrostatic waves in the plasma. Furthermore, dispersion relations and their modifications due to quantum effects are used for calculating the power loss of an oscillating electric dipole. Finally, the results are compared in quantum and classical regimes.

Ghaderipoor, L. [Department of Physics, Faculty of Science, University of Qom, 3716146611 (Iran, Islamic Republic of); Mehramiz, A. [Department of Physics, Faculty of Science, Imam Khomeini Int'l University, Qazvin 34149-16818 (Iran, Islamic Republic of)

2012-12-15

198

Implementation of an offset-dipole magnetic field in a pulsar modelling code  

E-print Network

The light curves of gamma-ray pulsars detected by the Fermi Large Area Telescope show great variety in profile shape and position relative to their radio profiles. Such diversity hints at distinct underlying magnetospheric and/or emission geometries for the individual pulsars. We implemented an offset-dipole magnetic field in an existing geometric pulsar modelling code which already includes static and retarded vacuum dipole fields. In our model, this offset is characterised by a parameter epsilon (with epsilon = 0 corresponding to the static dipole case). We constructed sky maps and light curves for several pulsar parameters and magnetic fields, studying the effect of an offset dipole on the resulting light curves. A standard two-pole caustic emission geometry was used. As an application, we compared our model light curves with Fermi data for the bright Vela pulsar.

Breed, M; Harding, A K; Johnson, T J

2014-01-01

199

Bipolar and unipolar tests of 1. 5m model SSC collider dipole magnets at Fermilab  

SciTech Connect

Tests have been performed at Fermilab on 1.5 m magnetic length model SSC collider dipoles using both bipolar and unipolar ramp cycles. Hysteresis energy loss due to superconductor and iron magnetization and eddy currents is measured and compared as a function of various ramp parameters. Additionally, magnetic field measurements have been performed for both unipolar and bipolar ramp cycles. Measurements such as these will be used to estimate the heat load during collider injection for the SSC High Energy Booster dipoles. 9 refs., 4 figs.

Lamm, M.J.; Ozelis, J.P.; Coulter, K.J.; Delchamps, S.; Jaffery, T.S.; Kinney, W.; Koska, W.; Strait, J.; Wake, M. (Fermi National Accelerator Lab., Batavia, IL (USA)); Fortunato, D.; Johnson, D.E. (Superconducting Super Collider Lab., Dallas, TX (USA))

1991-05-01

200

Cryostat design for the Superconducting Super Collider 50mm aperture dipole magnet  

Microsoft Academic Search

The cryostat of an SSC dipole magnet consists of all magnet components except the cold mass assembly. It serves to support the cold mass accurately and reliably within the vacuum vessel, provide all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. It must function reliably during storage, shipping and handling, normal

T. H. Nicol; Y. P. Tsavalas

1990-01-01

201

Collaborative Simulation and Testing of the Superconducting Dipole Prototype Magnet for the FAIR Project  

Microsoft Academic Search

The superconducting dipole prototype magnet of the collector ring for the Facility for Antiproton and Ion Research (FAIR) is an international cooperation project. The collaborative simulation and testing of the developed prototype magnet is presented in this paper. To evaluate the mechanical strength of the coil case during quench, a 3-dimensional (3D) electromagnetic (EM) model was developed based on the

Zhu Yinfeng; Zhu Zhe; Xu Houchang; Wu Weiyue

2012-01-01

202

Search for a permanent electric dipole moment using liquid 129Xe  

SciTech Connect

Search for an electric dipole moment is one of the best motivated low-energy approaches for investigating physics beyond the Standard Model. Our experimental effort is focused on improving the limit on EDM in liquid 129Xe to put constraints on nuclear CP-violating interactions. High nuclear spin density and high electrical breakdown strength make 129Xe a promising medium for EDM searches. At the time the project started, the transverse nuclear spin relaxation time T2 of 129Xe was unknown. We made measurements of T2 using NMR spin-echo techniques and found that it is exceeds 1300 sec, the longest relaxation time ever measured in a liquid [1]. We also began to investigate non-linear dipolar interaction effects in a high-density spin-polarized liquid Xe. In the second iteration of the experiment we setup a high-Tc SQUID system in magnetic shields and performed detailed studies of Xe spin precession. We developed a model for non-linear dipolar interactions and found that for one set of conditions non-linear interactions can delay spin dephasing due to magnetic field gradients, while for another set of conditions they can lead to exponential amplification of the spin precession signals [2]. Our experimental data were in good quantitative agreement with predictions of the model. We also developed a series of numerical simulations to understand various imperfections in the system and made detailed experimental measurements to confirm these numerical predictions [3]. We demonstrated that non-linear interactions can amplify small precession signals and achieved an amplification factor of 10 [4]. This general phenomenon can be used in other precision measurements with non-linear interactions. We also explored practical applications of the liquid Xe system that we developed. We demonstrated that by mixing Xe with organic liquids, such as cyclopentane, one can enhance the proton spin polarization by a factor of 106 [5]. We have used this technique to perform the first measurement of the scalar J-coupling between nuclear spins in van-der-Waals molecules, something that has never been observed before. More recently, we constructed a liquid-He apparatus to acquire Xe spin precession data using a low-Tc SQUID and achieved a signal-to-noise ratio of 106. We are currently investigating factors affecting the stability of Xe spin precession signals in this system using a superconducting magnetic shield and a persistent current magnetic field coil.

PROFESSOR MICHAEL ROMALIS

2008-11-24

203

Features of multi-dipole magnetic field structures in CP stars  

NASA Astrophysics Data System (ADS)

Ten of the sixty investigated magnetic stars have two- or three-dipole structures. From the viewpoint of the relic hypothesis a wide variety of magnetic field structures and strengths allows to assume that in the initial phases of formation of magnetic stars, their fields were even more entangled and heterogeneous than now. This may be due to the complex structure of protostellar clouds, the consequence of non-stationary processes during the collapse, and, probably, the result of subsequent accretion interactions. The expected variation of the large-scale structure with age is lost at the background of a wide variety of structures, depending on the initial conditions. Complex structures occur both in the stars at ZAMS, and in the stars leaving the Main Sequence. As a result of quadratic dependence of the magnetic structure lifetime on their characteristic dimensions, large-scale configurations can exist for times comparable to the lifetime of stellar magnetic field, i.e. ? ? 109 yrs. One of the common properties of multi-dipole stars is that the centers of the dipoles are predominantly located in the equatorial plane of rotation. In the majority of studied objects magnetic dipoles (i.e. the regions with the maximum field) are shifted from the center of the star by the distance greater than the radius of the convective core (approximately 0.1 R*). This may indicate that the poloidal field is not compatible with the convective core and is not generated therein. Large distances between the monopoles, comparable to the radii of the stars are typical. This may be a sign indicating that inside the stars the field structure is slightly different from the dipole, what implies that the dipole is not a mathematical point, but rather some highly magnetized volume inside the star, comparable to a magnetized rod.

Glagolevskij, Yu. V.

2013-07-01

204

Passive superconductor: A viable method of controlling magnetization multipoles in the SSC dipole  

SciTech Connect

At injection, the magnetization of the superconductor produces the dominant field error in the SSC dipole magnets. The field generated by magnetization currents in the superconductor is rich in higher symmetric multipoles (normal sextupole, normal decapole, and so on). Pieces of passive superconductor properly located within the bore of the dipole magnet can cancel the higher multipoles generated by the SSC dipole coils. The multipoles generated by the passive superconductor (predominantly sextupole and decapole) are controlled by the angular and radial location of the superconductor, the volume of superconductor, and the size of the superconducting filaments within the passive conductor. This paper will present the tolerances on each of these factors. The paper will show that multipole correction using passive superconductor is in general immune to the effects of temperature and magnetization decay due to flux creep, provided that dipole superconductor and the passive correction superconductor are properly specified. When combined with a lumped correction system, the passive superconductor can be a viable alternative to continuous correction coils within the SSC dipoles. 20 refs., 8 figs., 2 tabs.

Green, M.A.

1989-02-01

205

Quantifying and controlling the magnetic dipole contribution to 1.5-?m light emission in erbium-doped yttrium oxide  

NASA Astrophysics Data System (ADS)

We experimentally quantify the contribution of magnetic dipole (MD) transitions to the near-infrared light emission from trivalent erbium-doped yttrium oxide (Er3+:Y2O3). Using energy-momentum spectroscopy, we demonstrate that the 4I13/2?4I15/2 emission near 1.5 ?m originates from nearly equal contributions of electric dipole (ED) and MD transitions that exhibit distinct emission spectra. We then show how these distinct spectra, together with the differing local density of optical states for ED and MD transitions, can be leveraged to control Er3+ emission in structured environments. We demonstrate that far-field emission spectra can be tuned to resemble almost pure emission from either ED or MD transitions and show that the observed spectral modifications can be accurately predicted from the measured ED and MD intrinsic emission rates.

Li, Dongfang; Jiang, Mingming; Cueff, Sébastien; Dodson, Christopher M.; Karaveli, Sinan; Zia, Rashid

2014-04-01

206

Theoretical study of the electric dipole moment function of the ClO molecule  

NASA Technical Reports Server (NTRS)

The potential energy function and electric dipole moment function (EDMF) are computed for ClO X 2Pi using several different techniques to include electron correlation. The EDMF is used to compute Einstein coefficients, vibrational lifetimes, and dipole moments in higher vibrational levels. The band strength of the 1-0 fundamental transition is computed to be 12 + or - 2 per sq cm atm determined from infrared heterodyne spectroscopy. The theoretical methods used include SCF, CASSCF, multireference singles plus doubles configuration interaction (MRCI) and contracted CI, coupled pair functional (CPF), and a modified version of the CPF method. The results obtained using the different methods are critically compared.

Pettersson, L. G. M.; Langhoff, S. R.; Chong, D. P.

1986-01-01

207

Sources of electric brain activity: intracortical current dipoles  

Microsoft Academic Search

Intracortical evoked potentials after electrical stimulation of the optic nerve were simultaneously recorded from the different layers of the rabbit's visual cortex. The averaged potentials were subjected to current source density analyses. The results show that the first event after the stimulus is a current sink in layer VI according to the excitatory terminations of the specific afferent fibres of

P Rappelsberger; H Pockberger; H Petsche

1993-01-01

208

Interpretation of a dipole-dipole electrical resistivity survey, Colado geothermal area, Pershing County, Nevada  

SciTech Connect

An electrical resistivity survey in the Colado geothermal area, Pershing County, Nevada has defined areas of low resistivity on each of five lines surveyed. Some of these areas appear to be fault controlled. Thermal fluids encountered in several drill holes support the assumption that the hot fluids may be associated with areas of low resistivity. The evidence of faulting as interpreted from modeling of the observed resistivity data is therefore particularly significant since these structures may be the conduits for the thermal fluids. Sub-allurial fault zones are interpreted to occur between stations 0 to 5 NW on Line D and on Line A between stations 4 NW and 4 SE. Fault zones are also interpreted on Line C near stations 1 NW, 1 SE, and 3 SE, and on Line E between stations 2 to 4 NW and near 1 SE. No faulting is evident under the alluvial cover on the southwest end of Line B. A deep conductive zone is noted within the mountain range on two resistivity lines. There is no definite indication that thermal fluids are associated with this resistivity feature.

Mackelprang, C.E.

1980-09-01

209

Interpretation of dipole-dipole electrical resistivity survey, Colado geothermal area, Pershing County, Nevada  

NASA Astrophysics Data System (ADS)

An electrical resistivity survey in the Colado geothermal area, Pershing County, Nevada has defined areas of low resistivity on each of five lines surveyed. Some of these areas appear to be fault controlled. Thermal fluids encountered in several drill holes support the assumption that the hot fluids may be associated with areas of low resistivity. The evidence of faulting as interpreted from modeling of the observed resistivity data is therefore particularly significant since these structures may be the conduits for the thermal fluids. Sub-alluvial fault zones are interpreted to occur between stations 0-5 NW on Line D and on Line A between stations 4 NW and 4 SE. Fault zones are also interpreted on Line C near stations 1 NW, 1 SE, and 3 SE, and on Line E between stations 2-4 NW and near 1 SE. No faulting is evident under the alluvial cover on the southwest end of Line B. A deep conductive zone is noted within the mountain range on two resistivity lines. There is no definite indication that thermal fluids are associated with this resistivity feature.

Mackelprang, C. E.

1980-09-01

210

Translationally invariant semi-classical electrodynamics of magnetic media to electric octopole-magnetic quadrupole order  

NASA Astrophysics Data System (ADS)

We consider semi-classical macroscopic electrodynamics that is translationally invariant (independent of the choice of an arbitrary, implicit set of coordinate origins for molecule-fixed axes) for linear, homogeneous, anisotropic media interacting with harmonic, plane electromagnetic waves. We extend a previous formulation at electric octopole-magnetic quadrupole order to include media comprising magnetic molecules (those possessing both time-even and time-odd properties). This requires two additional invariant, time-odd molecular polarizabilities. Overall, the electrodynamics depends on 10 invariant polarizabilities—5 time even (one each of electric dipole and electric quadrupole-magnetic dipole order, and three of electric octopole-magnetic quadrupole order) and 5 time odd (one, two, and two, respectively)—that are required for the description of linear transmission and reflection phenomena, and material constants. The two additional time-odd polarizabilities account for certain predicted effects, and one of them contributes to the inverse ac permeability of magnetic media. The results are presented in a form that is suitable for numerical computation.

Welter, A.; Raab, R. E.; de Lange, O. L.

2013-02-01

211

Experimental Verification of Isotropic Radiation from a Coherent Dipole Source via Electric-Field-Driven LC Resonator Metamaterials  

NASA Astrophysics Data System (ADS)

It has long been conjectured that isotropic radiation by a simple coherent source is impossible due to changes in polarization. Though hypothetical, the isotropic source is usually taken as the reference for determining a radiator’s gain and directivity. Here, we demonstrate both theoretically and experimentally that an isotropic radiator can be made of a simple and finite source surrounded by electric-field-driven LC resonator metamaterials designed by space manipulation. As a proof-of-concept demonstration, we show the first isotropic source with omnidirectional radiation from a dipole source (applicable to all distributed sources), which can open up several possibilities in axion electrodynamics, optical illusion, novel transformation-optic devices, wireless communication, and antenna engineering. Owing to the electric- field-driven LC resonator realization scheme, this principle can be readily applied to higher frequency regimes where magnetism is usually not present.

Tichit, Paul-Henri; Burokur, Shah Nawaz; Qiu, Cheng-Wei; de Lustrac, André

2013-09-01

212

TOSCA calculations and measurements for the SLAC SLC damping ring dipole magnet  

SciTech Connect

The SLAC damping ring dipole magnet was originally designed with removable nose pieces at the ends. Recently, a set of magnetic measurements was taken of the vertical component of induction along the center of the magnet for four different pole-end configurations and several current settings. The three dimensional computer code TOSCA, which is currently installed on the National Magnetic Fusion Energy Computer Center's Cray X-MP, was used to compute field values for the four configurations at current settings near saturation. Comparisons were made for magnetic induction as well as effective magnetic lengths for the different configurations. 1 ref., 12 figs., 2 tabs.

Early, R.A.; Cobb, J.K.

1985-04-01

213

Hindered magnetic dipole transition in the covariant light-front approach  

E-print Network

Hindered magnetic dipole transitions $\\Upsilon(nS)\\to \\gamma \\eta_b(n'S)$ are studied in the covariant light-front approach. Compared with the allowed magnetic dipole transitions, we find that results for hindered magnetic dipole transitions are sensitive to heavy quark mass and shape parameters of the light-front wave functions. It is possible to tune the parameters so that the predictions of branching fractions of $\\Upsilon(2S,3S)\\to\\gamma\\eta_b$ are consistent with the recent experimental data, but the relevant decay constant of $\\eta_b$ is much smaller than that of $\\Upsilon(1S)$. We also generalize the investigation to the charmonium sector and find the the same conclusion.

Wei Wang

2010-02-18

214

Theoretical Study of the Electric Dipole Moment Function of the CIO Molecule  

NASA Technical Reports Server (NTRS)

The potential energy function and electric dipole moment function (EDMF) are computed for CIO Chi(sup 2)Pi using several different techniques to include electron correlation. The EDMF is used to compute Einstein coefficients, vibrational lifetimes, and dipole moments in higher vibrational levels. Remaining questions concerning the position of the maximum of the EDMF may be resolved through experimental measurement of dipole moments of higher vibrational levels. The band strength of the 1-0 fundamental transition is computed to be 12 +/- 2 /sq cm atm in good agreement with three experimental values, but larger than a recent value of 5 /sq cm atm determined from infrared heterodyne spectroscopy. The theoretical methods used include SCF, CASSCF, multireference singles plus doubles configuration interaction (MRCI) and contracted CI, coupled pair functional (CPF), and a modified version of the CPF method. The results obtained using the different methods are critically compared.

Pettersson, Lars G. M.; Langhoff, Stephen R.; Chong, Delano P.

1986-01-01

215

Neutral Fermion Having Electric and Magnetic Moments in an External Electromagnetic Field  

Microsoft Academic Search

We show that in 2+1 dimensions, the Dirac equation for a neutral fermion possessing electric and magnetic dipole moments in an external electromagnetic field reduces to the Dirac equation for a “charged” fermion in a external field characterized by a certain “3-pseudo-vector potential.” The effective charge of the neutral fermion is determined by its dipole moments. The effects of coupling

V. R. Khalilov

2001-01-01

216

Radiation effects in a muon collider ring and dipole magnet protection  

SciTech Connect

The requirements and operating conditions for a Muon Collider Storage Ring (MCSR) pose significant challenges to superconducting magnets. The dipole magnets should provide a high magnetic field to reduce the ring circumference and thus maximize the number of muon collisions during their lifetime. One third of the beam energy is continuously deposited along the lattice by the decay electrons at the rate of 0.5 kW/m for a 1.5-TeV c.o.m. and a luminosity of 10{sup 34} cm{sup -2}s{sup -1}. Unlike dipoles in proton machines, the MCSR dipoles should allow this dynamic heat load to escape the magnet helium volume in the horizontal plane, predominantly towards the ring center. This paper presents the analysis and comparison of radiation effects in MCSR based on two dipole magnets designs. Tungsten masks in the interconnect regions are used in both cases to mitigate the unprecedented dynamic heat deposition and radiation in the magnet coils.

Mokhov, N.V.; Kashikhin, V.V.; Novitski, I.; Zlobin, A.V.; /Fermilab

2011-03-01

217

Electric dipole response of He6: Halo-neutron and core excitations  

NASA Astrophysics Data System (ADS)

Electric dipole (E1) response of He6 is studied with a fully microscopic six-body calculation. The wave functions for the ground and excited states are expressed as a superposition of explicitly correlated Gaussians. Final state interactions of three-body decay channels are explicitly taken into account. The ground state properties and the low-energy E1 strength are obtained consistently with observations. Two main peaks as well as several small peaks are found in the E1 strength function. The peak at the high-energy region indicates a typical macroscopic picture of the giant dipole resonance, the out-of-phase proton-neutron motion. The transition densities of the lower-lying peaks exhibit in-phase proton-neutron motion in the internal region, out-of-phase motion near the surface region, and spatially extended neutron oscillation, indicating a soft-dipole mode and its vibrationally excited mode. The compressional dipole strength is also examined in relation to the soft-dipole mode.

Mikami, D.; Horiuchi, W.; Suzuki, Y.

2014-06-01

218

Molecular Expressions: Electricity & Magnetism: Resistance  

NSDL National Science Digital Library

Comprehensive tutorial on resistance, accompanied by three interactive simulations. One allows the user to glimpse resistance at a molecular level; the second explores Ohm's Law; and the third introduces the use of color coding in composition resistors. The author uses diagrams to illustrate arrangements of resistors in series and parallel circuits, with explanations of how to calculate equivalent resistances. This item is part of a larger collection on Electricity and Magnetism sponsored by Florida State University..

Davidson, Michael

219

The prospects for a new search for the electron electric dipole moment in solid Gadolinium iron garnet ceramics  

E-print Network

We address a number of issues regarding solid state electron electric dipole moment (EDM) experiments, focusing on gadolinium iron garnet (abbreviated GdIG, chemical formula Gd$_3$Fe$_5$O$_{12}$) as a possible sample material. GdIG maintains its high magnetic susceptibility down to 4.2 K, which enhances the EDM-induced magnetization of a sample placed in an electric field. We estimate that lattice polarizability gives rise to an EDM enhancement factor of approximately 20. We also calculate the effect of the demagnetizing field for various sample geometries and permeabilities. Measurements of intrinsic GdIG magnetization noise are presented, and the fluctuation-dissipation theorem is used to compare our data with the measurements of the imaginary part of GdIG permeability at 4.2 K, showing good agreement above frequencies of a few hertz. We also observe how the demagnetizing field suppresses the noise-induced magnetic flux, confirming our calculations. The statistical sensitivity of an EDM search based on a so...

Sushkov, A O; Lamoreaux, S K

2008-01-01

220

Development of a SQUID-based 3He Co-magnetometer Readout for a Neutron Electric Dipole Moment Experiment  

E-print Network

A discovery of a permanent electric dipole moment (EDM) of the neutron would provide one of the most important low energy tests of the discrete symmetries beyond the Standard Model of particle physics. A new search of neutron EDM, to be conducted at the spallation neutron source (SNS) at ORNL, is designed to improve the present experimental limit of ~10^-26 e-cm by two orders of magnitude. The experiment is based on the magnetic-resonance technique in which polarized neutrons precess at the Larmor frequency when placed in a static magnetic field; a non-zero EDM would be evident as a difference in precession frequency when a strong external electric field is applied parallel vs. anti-parallel to the magnetic field. In addition to its role as neutron spin-analyzer via the spin-dependent n+3He nuclear capture reaction, polarized helium-3 (which has negligible EDM) will serve as co-magnetometer to correct for drifts in the magnetic field. In one of the two methods that will be built into the apparatus, the helium-3 precession signal is read out by SQUID-based gradiometers. We present a design study of a SQUID system suitable for the neutron EDM apparatus, and discuss using very long leads between the pickup loop and the SQUID.

Young Jin Kim; Steven M. Clayton

2012-10-17

221

Development of a SQUID-based 3He Co-magnetometer Readout for a Neutron Electric Dipole Moment Experiment  

E-print Network

A discovery of a permanent electric dipole moment (EDM) of the neutron would provide one of the most important low energy tests of the discrete symmetries beyond the Standard Model of particle physics. A new search of neutron EDM, to be conducted at the spallation neutron source (SNS) at ORNL, is designed to improve the present experimental limit of ~10^-26 e-cm by two orders of magnitude. The experiment is based on the magnetic-resonance technique in which polarized neutrons precess at the Larmor frequency when placed in a static magnetic field; a non-zero EDM would be evident as a difference in precession frequency when a strong external electric field is applied parallel vs. anti-parallel to the magnetic field. In addition to its role as neutron spin-analyzer via the spin-dependent n+3He nuclear capture reaction, polarized helium-3 (which has negligible EDM) will serve as co-magnetometer to correct for drifts in the magnetic field. In one of the two methods that will be built into the apparatus, the helium...

Kim, Young Jin

2012-01-01

222

Highly polar states of Rydberg atoms in strong magnetic and weak electric fields  

NASA Astrophysics Data System (ADS)

We study the spectra of diamagnetic rubidium Rydberg atoms in strong magnetic and weak electric parallel fields, in the n-mixing regime. Our emphasis is on isolated pairs of near-degenerate, opposite-parity, diamagnetic states that become mixed by the weak electric field. Such level pairs allow for the generation of nondegenerate states with large, tunable permanent electric dipole moments and large optical excitation cross sections from the atomic ground state. We investigate how the dipole moments and the zero-electric-field energy defects of these level pairs can be tuned using small variations of the electric and magnetic fields. Using calculations, we explore the abundance of such level pairs over wide spectral regions for several magnetic quantum numbers. Applications of polar, diamagnetic Rydberg states in Rydberg-atom interaction experiments are briefly discussed.

Paradis, E.; Zigo, S.; Raithel, G.

2013-01-01

223

AC loss measurements of model and full size 50mm SSC collider dipole magnets at Fermilab  

SciTech Connect

Tests have recently been performed at Fermilab in order to measure the energy losses due to eddy currents and iron and superconductor magnetization. These measurements were performed on six 1.5m long model magnets and eight 15m long full scale collider dipole magnets. AC losses were measured as a function of ramp rate using sawtooth ramps from 500, to 5000 Amps for both types of magnets, while bipolar studies were additionally performed on some of the short magnets. The measured magnet voltage and current for a complete cycle are digitally integrated to yield the energy loss per cycle. Measurement reproducibility is typically 5%, with good agreement between long magnet measurements and extrapolations from short magnet measurement results. Magnetization loss measurements among similar magnet types agree to within experimental error, while eddy current losses correlate strongly with the observed dependence of quench current on ramp rate.

Ozelis, J.P.; Delchamps, S.W.; Gourlay, S.; Jaffery, T.; Kinney, W.; Koska, W.; Kuchnir, M.; Lamm, M.J.; Mazur, P.O.; Orris, D.; Strait, J.; Wake, M. (Fermi National Accelerator Lab., Batavia, IL (United States)); Dimarco, J.; Kuzminski, J.; Zheng, H. (Superconducting Super Collider Lab., Dallas, TX (United States))

1992-09-01

224

Polarity Reversal Time of the Magnetic Dipole Component of the Sun in Solar Cycle 24  

NASA Astrophysics Data System (ADS)

The Sun's general magnetic field has shown polarity reversal three times during the last three solar cycles. We attempt to estimate the upcoming polarity reversal time of the solar magnetic dipole by using the coronal field model and synoptic data of the photospheric magnetic field. The scalar magnetic potential of the coronal magnetic field is expanded into a spherical harmonic series. The long-term variations of the dipole component (g01) calculated from the data of National Solar Observatory/Kitt Peak and Wilcox Solar Observatory are compared with each other. It is found that the two g01 values show a similar tendency and an approximately linear increase between the Carrington rotation periods CR 2070 and CR 2118. The next polarity reversal is estimated by linear extrapolation to be between CR 2132.2 (December 2012) and CR2134.8 (March 2013).

Hakamada, Kazuyuki

2013-04-01

225

An update on passive correctors for the SSC dipole magnets  

Microsoft Academic Search

The concept of correction of the magnetization sextupole became a topic of discussion as soon as it was realized that superconductor magnetization could have a serious effect on the SSC beam during injection. Several methods of correction were proposed. These included (1) correction with active bore tube windings like those on the HERA machine which correct out magnetization sextupole and

M. A. Green

1991-01-01

226

Probing CP violation with the electric dipole moment of atomic mercury  

E-print Network

The electric dipole moment of atomic $^{199}$Hg induced by the nuclear Schiff moment and tensor-pseudotensor electron-nucleus interactions has been calculated. For this, we have developed and employed a novel method based on the relativistic coupled-cluster theory. The results of our theoretical calculations combined with the latest experimental result of $^{199}$Hg electric dipole moment, provide new bounds on the T reversal or CP violation parameters $\\theta_{\\rm QCD}$, the tensor-pseudotensor coupling constant $C_T$ and $(\\widetilde{d}_u - \\widetilde{d}_d)$. This is the most accurate calculation of these parameters to date. We highlight the the crucial role of electron correlation effects in their interplay with the P,T violating interactions. Our results demonstrate substantial changes in the results of earlier calculations of these parameters which can be attributed to the more accurate inclusion of important correlation effects in the present work.

K. V. P. Latha; D. Angom; B. P. Das; D. Mukherjee

2009-02-27

227

Electric dipole moments of leptons in the presence of Majorana neutrinos  

Microsoft Academic Search

We calculate the two-loop diagrams that give a nonzero contribution to the electric dipole moment dl of a charged lepton l due to possible Majorana masses of neutrinos. Using the example with one generation of the standard model leptons and two heavy right-handed neutrinos, we demonstrate that the nonvanishing result for dl first appears in order O(mlm2nuG2F), where mnu is

John Paul Archambault; Andrzej Czarnecki; Maxim Pospelov

2004-01-01

228

Larger Higgs-boson-exchange terms in the neutron electric dipole moment  

Microsoft Academic Search

The neutron electric dipole moment (dn) due to Higgs-boson exchange is reconsidered, now without assuming that Higgs-boson exchange is solely responsible for K0L-->2pi. The dominant contribution to dn arises from a three-gluon operator, produced in integrating out top quarks and neutral Higgs bosons. The estimated results together with current experimental bounds on dn show, even for the largest plausible Higgs-boson

Steven Weinberg

1989-01-01

229

Experimental search for the electron electric dipole moment with laser cooled francium atoms  

NASA Astrophysics Data System (ADS)

A laser cooled heavy atom is one of the candidates to search for the permanent electric dipole moment (EDM) of the electron due to the enhancement mechanism and its long coherence time. The laser cooled francium (Fr) factory has been constructed to perform the electron EDM search at the Cyclotron and Radioisotope Center, Tohoku University. The present status of Fr production and the EDM measurement system is presented.

Inoue, T.; Ando, S.; Aoki, T.; Arikawa, H.; Ezure, S.; Harada, K.; Hayamizu, T.; Ishikawa, T.; Itoh, M.; Kato, K.; Kawamura, H.; Uchiyama, A.; Aoki, T.; Asahi, K.; Furukawa, T.; Hatakeyama, A.; Hatanaka, K.; Imai, K.; Murakami, T.; Nataraj, H. S.; Sato, T.; Shimizu, Y.; Wakasa, T.; Yoshida, H. P.; Yoshimi, A.; Sakemi, Y.

2014-12-01

230

Shell model estimate of electric dipole moments in medium and heavy nuclei  

NASA Astrophysics Data System (ADS)

It is evidence for an extension of the Standard Model in particle physics, if static electric dipole moments (EDMs) are measured for any elementary particle. The nuclear EDM arises mainly from two sources: one comes from asymmetric charge distribution in a nucleus and the other is due to the nucleon intrinsic EDM. We estimate the nuclear EDMs from two sources for the 1/21+ states in Xe isotopes by a shell model approach using full orbitals between magic numbers 50 and 82.

Teruya, E.; Yoshinaga, N.; Higashiyama, K.

2014-03-01

231

Twin rotating coils for cold magnetic measurements of 15 m long LHC dipoles  

Microsoft Academic Search

We describe here a new harmonic coil system for the field measurement of the superconducting, twin aperture LHC dipoles and the associated corrector magnets. Besides field measurements the system can be used as an antenna to localize the quench origin. The main component is a 16 m long rotating shaft, made up of 13 ceramic segments, each carrying two tangential

J. Billan; L. Bottura; M. Buzio; G. D'Angelo; G. Deferne; O. Dunkel; P. Legrand; A. Rijllart; A. Siemko; P. Sievers; S. Schloss; L. Walckiers

2000-01-01

232

Different Paths to Some Fundamental Physical Laws: Relativistic Polarization of a Moving Magnetic Dipole  

ERIC Educational Resources Information Center

In this paper we consider the relativistic polarization of a moving magnetic dipole and show that this effect can be understood via the relativistic generalization of Kirchhoff's first law to a moving closed circuit with a steady current. This approach allows us to better understand the law of relativistic transformation of four-current density…

Kholmetskii, Alexander L.; Yarman, T.

2010-01-01

233

Risk Assessment of the Chopper Dipole Kicker Magnets for the MedAustron Facility  

Microsoft Academic Search

The MedAustron facility, to be built in Wiener Neustadt (Austria), will provide protons and ions for both cancer therapy and research [1]. Different types of kicker magnets will be used in the accelerator complex, including fast beam chopper dipoles: these allow the beam to be switched on and off for routine operational reasons or in case of emergency. Main requirements

T Kramer; T Stadlbauer; M J Barnes; M Benedikt; T Fowler

2011-01-01

234

Development of cos-theta Nb{sub 3}Sn dipole magnets for VLHC  

SciTech Connect

This paper describes the double aperture dipole magnets developed for a VLHC based on Nb{sub 3}Sn superconductor, a cos-theta coil, cold and warm iron yokes, and the wind-and-react fabrication technique. Status of the model R and D program, strand and cable and other major component development are also discussed.

Alexander Zlobin et al.

2001-07-20

235

Alternate manufacturing processes and materials for the SSC dipole magnet coil end parts  

Microsoft Academic Search

Modern magnet designs such as the SSC dipole utilize smaller bore diameter and wider superconducting cable. Challenging winding techniques place greater emphasis on the role of the coil end parts. Their complex configuration is derived from their function of confining the conductors to a consistent given shape and location. Present end parts, made of G-10 composite, are manufactured utilizing complex

A. Lipski; R. Bossert; J. Brandt; J. Hoffman; G. Kobliska; J. Zweibohmer; W. Higinbotham; R. Shields; R. Sims

1992-01-01

236

R Measurements With ISR in BaBar: Hadronic Part of Muon Magnetic Dipole Moment  

SciTech Connect

Recent measurements of the quantity R, the ratio of annihilation {sigma}, including those following Initial State Radiation, are discussed in the context of the hadronic part of {mu}, the muon magnetic dipole moment. The data indicate that more precise theoretical and experimental values of {mu} are needed to establish whether new physics has been observed in the measurement of {mu}.

Taras, P.; /Quebec U., Montreal

2007-07-09

237

Observation of Centrifugally Driven Interchange Instabilities in a Plasma Confined by a Magnetic Dipole  

SciTech Connect

Centrifugally driven interchange instabilities are observed in a laboratory plasma confined by a dipole magnetic field. The instabilities appear when an equatorial mesh is biased to drive a radial current that causes rapid axisymmetric plasma rotation. The observed instabilities are quasicoherent in the laboratory frame of reference; they have global radial mode structures and low azimuthal mode numbers, and they are modified by the presence of energetic, magnetically confined electrons. Results from a self-consistent nonlinear simulation reproduce the measured mode structures.

Levitt, B.; Maslovsky, D.; Mauel, M.E. [Department of Applied Physics and Applied Mathematics Columbia University, New York, New York 10027 (United States)

2005-05-06

238

Prospects for the measurement of the electron electric dipole moment using YbF  

E-print Network

We discuss an experiment underway at Imperial College London to measure the permanent electric dipole moment (EDM) of the electron using a molecular beam of YbF. We describe the measurement method, which uses a combination of laser and radiofrequency resonance techniques to detect the spin precession of the YbF molecule in a strong electric field. We pay particular attention to the analysis scheme and explore some of the possible systematic effects which might mimic the EDM signal. Finally, we describe technical improvements which should increase the sensitivity by more than an order of magnitude over the current experimental limit.

Sauer, B E; Kara, D M; Smallman, I J; Tarbutt, M R; Hinds, E A

2011-01-01

239

Structural performance of the first SSC (Superconducting Super Collider) Design B dipole magnet  

SciTech Connect

The first Design B Superconducting Super Collider (SSC) dipole magnet has been successfully tested. This magnet was heavily instrumented with temperature and strain gage sensors in order to evaluate its adherence to design constraints and design calculations. The instrumentation and associated data acquisition system allowed monitoring of the magnet during cooldown, warmup, and quench testing. This paper will focus on the results obtained from structural measurements on the suspension system during normal and rapid cooldowns and during quench studies at full magnet current. 4 refs., 9 figs.

Nicol, T.H.

1989-09-01

240

The electric and magnetic form factors of the proton  

E-print Network

The paper describes a precise measurement of electron scattering off the proton at momentum transfers of $0.003 \\lesssim Q^2 \\lesssim 1$\\ GeV$^2$. The average point-to-point error of the cross sections in this experiment is $\\sim$ 0.37%. These data are used for a coherent new analysis together with all world data of unpolarized and polarized electron scattering from the very smallest to the highest momentum transfers so far measured. The extracted electric and magnetic form factors provide new insight into their exact shape, deviating from the classical dipole form, and of structure on top of this gross shape. The data reaching very low $Q^2$ values are used for a new determination of the electric and magnetic radii. An empirical determination of the Two-Photon-Exchange (TPE) correction is presented. The implications of this correction on the radii and the question of a directly visible signal of the pion cloud are addressed.

A1 Collaboration; J. C. Bernauer; M. O. Distler; J. Friedrich; Th. Walcher; P. Achenbach C. Ayerbe Gayoso; R. Böhm; L. Debenjak; L. Doria; A. Esser; H. Fonvieille; M. Gómez Rodrígues de la Paz; J. M. Friedrich; M. Makek; H. Merkel; D. G. Middleton; U. Müller; L. Nungesser; J. Pochodzalla; M. Potokar; S. Sánchez Majos; B. S. Schlimme; S. Širca; M. Weinriefer

2014-07-29

241

Taming molecular collisions using electric and magnetic fields.  

PubMed

The motion of molecules that possess a permanent electric or magnetic dipole moment can be manipulated using electric or magnetic fields. Various devices have been developed over the last few decades to deflect or focus molecules, to orient them in space, and to decelerate or accelerate them. These precisely controlled molecules are ideal starting points for scattering experiments that reveal the quantum mechanical nature of molecular interactions. In this Tutorial Review, we present an overview of the various manipulation tools, discuss how they can be used to advantage in molecular beam scattering experiments, and review recent progress in this field. We describe a selection of benchmark experiments that illustrate the unique possibilities that are available nowadays to study molecular collisions under controlled conditions. PMID:25115818

Brouard, Mark; Parker, David H; van de Meerakker, Sebastiaan Y T

2014-11-01

242

Anisotropic property of magnetic dipole in bulk, surface, and overlayer systems  

NASA Astrophysics Data System (ADS)

Magnetization-angle dependence of the magnetic dipole is extensively studied for bulk, surface, and overlayer systems by using first-principles electronic structure calculations. In most transition-metal ferromagnets, the magnetic dipole is described well in a weak spin-orbit-interaction (SOI) regime with the angle dependence of 3cos2?-1 and the existence of the so-called magic angle. In a system with relatively strong SOI, such as Pt overlayer on Fe substrate, however, the angle dependence deviates from the 3cos2?-1 variation. An actinide compound shows completely different angle dependence arising from a competition between l·s coupling and crystal-field effect.

Oguchi, Tamio; Shishidou, Tatsuya

2004-07-01

243

Design and optimization of the 12.5 T EFDA dipole magnet  

NASA Astrophysics Data System (ADS)

The aim of this paper is to provide an overview of a recent study carried out—within the framework of the European Fusion Program—to design a 12.5 T superconducting dipole. By focusing on the CICC based design option, the overall design procedure is presented. In particular, the 2D optimization of the dipole cross section is described including the magneto-static analysis of the winding and iron yoke, the mechanical analysis of the conductor jacket, insulation and outer cylinder, the conductor hot spot analysis, etc. As far as the thermo-hydraulic design is concerned, simulations of nominal as well as offset operating conditions (e.g., magnet quench) are presented with emphasis on their role played in the overall magnet design. For example, diagrams reporting the helium heat removal capabilities, pressure drop, mass flow, etc. are shown and their usefulness as guidance for the magnet designer described.

Portone, A.; Salpietro, E.; Bottura, L.; Bruzzone, P.; Della Corte, A.; Fietz, W.; Heller, R.; Raff, S.; Lucas, J.; Toral, F.; Rifflet, J. M.; Testoni, P.

2006-07-01

244

Studies of time dependence of fields in TEVATRON superconducting dipole magnets  

SciTech Connect

The time variation in the magnetic field of a model Tevatron dipole magnet at constant excitation current has been studied. Variations in symmetry allowed harmonic components over long time ranges show a log t behavior indicative of ''flux creep.'' Both short time range and long time range behavior depend in a detailed way on the excitation history. Similar effects are seen in the remnant fields present in full-scale Tevatron dipoles following current ramping. Both magnitudes and time dependences are observed to depend on details for the ramps, such as ramp rate, flattop duration, and number of ramps. In a few magnets, variations are also seen in symmetry unallowed harmonics. 9 refs., 10 figs.

Hanft, R.W.; Brown, B.C.; Herrup, D.A.; Lamm, M.J.; McInturff, A.D.; Syphers, M.J.

1988-08-22

245

One-loop neutron electric dipole moment from supersymmetry without R parity  

NASA Astrophysics Data System (ADS)

We present a detailed analysis together with exact numerical calculations on one-loop contributions to the neutron electric dipole moment from supersymmetry without R parity, focusing on the gluino, chargino, and neutralino contributions. Apart from the neglected family mixing among quarks, complete formulas are given for the various contributions through the quark dipole operators, to which the present study is restricted. We discuss the structure and main features of the R-parity violating contributions and the interplay between the R-parity conserving and violating parameters. In particular, the parameter combination ?*i?'i11, under the optimal parametrization adopted, is shown to be solely responsible for the R-parity violating contributions in the supersymmetric loop diagrams. While ?*i?'i11 could bear a complex phase, the latter is not necessary to have a R-parity violating contribution.

Keum, Y.-Y.; Kong, Otto C.

2001-06-01

246

The Effects of an Induced Electric Dipole Moment due to Earth's Electric Field on the Artificial Satellites Orbit  

NASA Astrophysics Data System (ADS)

The orbits of artificial satellites are very sensitive to a large number of disturbances, whose effects add to the main force exerted by Earth's gravitational field. The most important perturbations, caused by solar radiation pressure, the Moon and the Sun gravitational fields, have been extensively discussed in the literature, and must be taken into account in order to correct the orbital motion, to prevent collisions between satellites in close orbits. In this paper we consider an additional source of acceleration arising from an electric dipole moment induced by the high altitude Earth electric field in a metallic satellite of spherical shape. The order of magnitude of such effect is estimated to be in the range of 10 - 23m/s2. It is emphasized that the electric dipole moment effect(EDME) is dependent on the satellite shape and geometry and proportional to E_0 v/r^4. The Earth electric field E 0 is largely influenced by atmospheric electromagnetic phenomena, such as whistler waves and thunderstorms.

Heilmann, Armando; Ferreira, Luiz Danilo Damasceno; Dartora, Cesar Augusto

2012-04-01

247

Interferometric methods for mapping static electric and magnetic fields  

NASA Astrophysics Data System (ADS)

The mapping of static electric and magnetic fields using electron probes with a resolution and sensitivity that are sufficient to reveal nanoscale features in materials requires the use of phase-sensitive methods such as the shadow technique, coherent Foucault imaging and the Transport of Intensity Equation. Among these approaches, image-plane off-axis electron holography in the transmission electron microscope has acquired a prominent role thanks to its quantitative capabilities and broad range of applicability. After a brief overview of the main ideas and methods behind field mapping, we focus on theoretical models that form the basis of the quantitative interpretation of electron holographic data. We review the application of electron holography to a variety of samples (including electric fields associated with p-n junctions in semiconductors, quantized magnetic flux in superconductors and magnetization topographies in nanoparticles and other magnetic materials) and electron-optical geometries (including multiple biprism, amplitude and mixed-type set-ups). We conclude by highlighting the emerging perspectives of (i) three-dimensional field mapping using electron holographic tomography and (ii) the model-independent determination of the locations and magnitudes of field sources (electric charges and magnetic dipoles) directly from electron holographic data.

Pozzi, Giulio; Beleggia, Marco; Kasama, Takeshi; Dunin-Borkowski, Rafal E.

2014-02-01

248

Time-reversal symmetry breaking and spontaneous Hall effect without magnetic dipole order.  

PubMed

Spin liquids are magnetically frustrated systems, in which spins are prevented from ordering or freezing, owing to quantum or thermal fluctuations among degenerate states induced by the frustration. Chiral spin liquids are a hypothetical class of spin liquids in which the time-reversal symmetry is macroscopically broken in the absence of an applied magnetic field or any magnetic dipole long-range order. Even though such chiral spin-liquid states were proposed more than two decades ago, an experimental realization and observation of such states has remained a challenge. One of the characteristic order parameters in such systems is a macroscopic average of the scalar spin chirality, a solid angle subtended by three nearby spins. In previous experimental reports, however, the spin chirality was only parasitic to the non-coplanar spin structure associated with a magnetic dipole long-range order or induced by the applied magnetic field, and thus the chiral spin-liquid state has never been found. Here, we report empirical evidence that the time-reversal symmetry can be broken spontaneously on a macroscopic scale in the absence of magnetic dipole long-range order. In particular, we employ the anomalous Hall effect to directly probe the broken time-reversal symmetry for the metallic frustrated magnet Pr(2)Ir(2)O(7). An onset of the Hall effect is observed at zero field in the absence of uniform magnetization, within the experimental accuracy, suggesting an emergence of a chiral spin liquid. The origin of this spontaneous Hall effect is ascribed to chiral spin textures, which are inferred from the magnetic measurements indicating the spin ice-rule formation. PMID:20010605

Machida, Yo; Nakatsuji, Satoru; Onoda, Shigeki; Tayama, Takashi; Sakakibara, Toshiro

2010-01-14

249

Patterned time-orbiting potentials for the confinement and assembly of magnetic dipoles  

PubMed Central

We present an all-magnetic scheme for the assembly and study of magnetic dipoles within designed confinement profiles that are activated on micro-patterned permalloy films through a precessing magnetic field. Independent control over the confinement and dipolar interactions is achieved by tuning the strength and orientation of the revolving field. The technique is demonstrated with superparamagnetic microspheres field-driven to assemble into closely packed lattice sheets, quasi-1D and other planar structures expandable into dipolar arrays that mirror the patterned surface motifs. PMID:24185093

Chen, A.; Sooryakumar, R.

2013-01-01

250

Radio emission characteristics of Pulsars and their magnetic dipole angle  

Microsoft Academic Search

We have made a statistical analysis on the subpulse width, the mean pulse width and the rate of change of polarization angle in pulsars. We obtained a number of empirical relations showing how these radio emission characteristics are related to the magnetic inclination and discussed the physical implications of the relations.

Zhen-Ru Wang; Yi Chu

1981-01-01

251

The permanent electric dipole moment of thorium sulfide, ThS.  

PubMed

Numerous rotational lines of the {18.26}1-X(1)?(+) band system of thorium sulfide, ThS, were recorded near 547.6 nm at a resolution of approximately 30 MHz. Measurements were made under field-free conditions, and in the presence of a static electric field. The field-free spectrum was analyzed to produce rotational and ?-doubling parameters. The Stark shifts induced by the electric field were analyzed to determine permanent electric dipole moments, ??el, of 4.58(10) D and 6.72(5) D for the X(1)?(+) (v = 0) and {18.26}1 states, respectively. The results are compared with the predictions of previous and new electronic structure calculations for ThS, and the properties of isovalent ThO. PMID:24437877

Le, Anh; Heaven, Michael C; Steimle, Timothy C

2014-01-14

252

Enhancement of the electron electric dipole moment in Eu{sup 2+}  

SciTech Connect

Recently, the ferroelectric Eu{sub 0.5}Ba{sub 0.5}TiO{sub 3} was suggested for experimental searches of the electron electric dipole moment. To analyze results of the experiment and interpret them in terms of fundamental constants, the effective electric field E{sub eff} acting on unpaired electrons of the europium cation should be calculated. In the present paper we consider Eu{sup 2+} cation in the uniform external electric field E{sub ext} as the first step and important starting point toward the calculation of E{sub eff} in the real solid. We have performed high-level electronic structure correlation calculations using the coupled clusters theory compared to other approaches. The calculated value of the field enhancement coefficient is K=E{sub eff}/E{sub ext}=-4.6.

Skripnikov, L.V.; Titov, A.V.; Petrov, A. N.; Mosyagin, N. S. [Petersburg Nuclear Physics Institute, Gatchina, Leningrad District 188300 (Russian Federation); Sushkov, O. P. [School of Physics, University of New South Wales, Sydney 2052 (Australia)

2011-08-15

253

A novel approach to measure the electric dipole moment of the isotope 129-Xe  

NASA Astrophysics Data System (ADS)

Permanent electric dipole moments (EDM) of fundamental systems are promising systems to find new CP violation beyond the Standard Model. Our EDM experiment is based on hyper-polarized liquid xenon droplets of sub-millimeter size on a micro-fabricated structure, placed in a low-field NMR setup. Implementation of rotating electric fields enables a conceptually new EDM measurement technique, allowing thorough investigation of systematic effects. Still, a Ramsey-type spin precession experiment with static electric field can be realized at similar sensitivity within the same setup. Employing superconducting pick-up coils and highly sensitive LTc-SQUIDs, a large array of independent measurements can be performed simultaneously. With our approach we aim to finally increase the sensitivity on the EDM of 129Xe by more than three orders of magnitude.

Kuchler, F.; Fierlinger, P.; Wurm, D.

2014-03-01

254

Dual AC Dipole Excitation for the Measurement of Magnetic Multipole Strength from Beam Position Monitor Data  

SciTech Connect

An experiment was conducted at Jefferson Lab's Continuous Electron Beam Accelerator Facility to develop a technique for characterizing the nonlinear fields of the beam transport system. Two air-core dipole magnets were simultaneously driven at two different frequencies to provide a time-dependent transverse modulation of the electron beam. Fourier decomposition of beam position monitor data was then used to measure the amplitude of these frequencies at different positions along the beamline. For a purely linear transport system one expects to find solely the frequencies that were applied to the dipoles with amplitudes that depend on the phase advance of the lattice. In the presence of nonlinear fields one expects to also find harmonics of the driving frequencies that depend on the order of the nonlinearity. The technique was calibrated using one of the sextupole magnets in a CEBAF beamline and then applied to a dipole to measure the sextupole and octupole strength of the magnet. A comparison is made between the beam-based measurements, results from TOSCA and data from our Magnet Measurement Facility.

M. Spata, G.A. Krafft

2011-09-01

255

Test of Fermilab built, post-ASST, 50-mm-aperture, full length SSC dipole magnets  

SciTech Connect

During 1992 at Fermilab, a series of nine 50-mm-aperture, 15-m-long, SSC superconducting dipole magnets, designed jointly by Fermilab, Brookhaven National Laboratory, and the SSC Laboratory, have been built and successfully cold tested. Seven of these dipole magnets, designate for the Accelerator System String Test (ASST) carried out at SSCL in Dallas, were assembled Fermilab by General Dynamics personnel, and have achieved the nominal operating current level without significant training. In addition, a series of four R&D magnets (DCA320 323) we manufactured at Fermilab to test an alternative insulation schemes. In this paper we present th quench performance of these four R&D magnets, which were cold tested at the Fermilab Magnet Test Facility at nominal temperatures of 4.35 K, 3.85 K, and 3.50 K. An extended characterization test was performed on one of these magnets (DCA322). During this test the magnet was successfully cooled down to superfluid He temperature (1.8 K) and reached a field B {ge} 9.5 T.

Kuzminski, J.; Akhmetov, A. [Superconducting Super Collider Lab., Dallas, TX (United States); Bossert, R. [Fermi National Accelerator Lab., Batavia, IL (United States)] [and others

1993-05-01

256

Spectrum analysis of the power line flicker induced by the electrical test of the prototype Booster dipole  

SciTech Connect

Testing of the prototype Booster dipole magnet at full current produced measurable disturbances of the beam position at the National Synchrotron Light Source. Power for the magnet and the NSLS are distributed from three substation transformers at Temple Place. Normally the substation configuration is for two independent 13.8 KV buses, derived from the 69 KV LILCO distribution. The buses are connected through a circuit breaker that is normally open circuited. Power for the magnet test is derived from one of the 13.8 KV buses and power for the NSLS is derived from the second bus. Coupling of the pulsating magnet load and the NSLS is at the 69 KV level. However, on the days that the interference was first observed at the NSLS only one-half of the substation transformers at Temple Place were in service. The 13.8 KV tie breaker was closed and the full substation load was supplied from this common bus. Thus the coupling between the pulsating magnet load and the NSLS was at the 13.8 KV level. Establishing the normal two bus configurations at Temple Place appeared to reduce the disturbance. These events suggested a controlled experiment to measure the magnet power swing and the induced powerline flicker; and from these measurements project the flicker on the lab site generated by the Booster operating at full energy. This experiment could corroborate the validity of the electrical models used in analyzing the power flow from the LILCO power grid and its distribution on the Lab site described in Accelerator Division Technical Note 220.

Meth, M.

1992-07-17

257

Formation of local electric dipoles with no unique polar axis in Tb3Fe5O12  

NASA Astrophysics Data System (ADS)

Using neutron scattering and the pair-density-function analysis, we investigated, the local atomic structure of the ferrimagnetic dielectric Tb3Fe5O12 garnet. Pronounced magnetic diffuse scattering is observed at high temperatures that gradually decreases with cooling as the Tb spins take on an ordered structure at about 50 K. In the temperature range where the dielectric (?) constant is enhanced, a volume striction is observed from the diffraction measurements under a magnetic field that couples the magnetic response to the dielectric properties. At the same time, large oxygen displacements, on the order of 0.1-0.2Å , are observed starting first at 90 K that persist up to 550 K, resulting in the formation of electric dipoles. However, they are not ordered and the lack of a unique polar axis in the hyperkagome structure may be linked to the absence of a polarized phase in this system. If it were present, the system could have a high ferroelectric transition temperature.

Louca, Despina; Kamazawa, K.; Proffen, T.

2009-12-01

258

Progress towards the search for the permanent electric dipole moment of Ra-225  

NASA Astrophysics Data System (ADS)

We are searching for the permanent electric dipole moment (EDM) of Radium-225. In this context, a nonzero EDM is a signature of time-reversal-symmetry violating interactions within nuclei. The Ra-225 radioisotope (half-life of 15 days) is an attractive choice because, due to its unusually large nuclear deformations, it is expected to be an extraordinarily sensitive probe to these types of interactions. In our measurement scheme, Ra atoms are first laser-cooled & -trapped in a magneto-optical trap. Subsequently they are transferred into an optical dipole trap, which is used to transport the atoms into the science chamber. Finally, the atoms are transferred into a more stable & confining optical dipole trap, where the measurement takes place. The first two steps have already been demonstrated. We will report on progress towards measurements of atomic properties necessary for the EDM search and the EDM search itself. This work is supported by DOE, Office of Nuclear Physics, under contract No. DE-AC02-06CH11357.

Singh, Jaideep; Bailey, Kevin; Dietrich, Matt R.; Greene, John P.; Holt, Roy J.; Kalita, Mukut R.; Korsch, Wolfgang; Lu, Zheng-Tian; Mueller, Peter; O'Connor, Tom P.; Parker, Richard H.; Sulai, Ibrahim A.

2011-10-01

259

Zeeman interaction in ThO H3?1 for the electron electric-dipole-moment search  

NASA Astrophysics Data System (ADS)

The current limit on the electron's electric dipole moment, |de|<8.7×10-29 ecm (90% confidence), was set using the molecule thorium monoxide (ThO) in the J =1 rotational level of its H3?1 electronic state [J. Baron et al., Science 343, 269 (2014), 10.1126/science.1248213]. This state in ThO is very robust against systematic errors related to magnetic fields or geometric phases, due in part to its ?-doublet structure. These systematics can be further suppressed by operating the experiment under conditions where the g-factor difference between the ? doublets is minimized. We consider the g factors of the ThO H3?1 state both experimentally and theoretically, including dependence on ? doublets, the rotational level, and the external electric field. The calculated and measured values are in good agreement. We find that the g-factor difference between ? doublets is smaller in J =2 than in J =1 and reaches zero at an experimentally accessible electric field. This means that the H ,J=2 state should be even more robust against a number of systematic errors compared to H ,J=1.

Petrov, A. N.; Skripnikov, L. V.; Titov, A. V.; Hutzler, N. R.; Hess, P. W.; O'Leary, B. R.; Spaun, B.; DeMille, D.; Gabrielse, G.; Doyle, J. M.

2014-06-01

260

Communication: The permanent electric dipole moment of thorium monoxide, ThO.  

PubMed

The optical Stark spectrum of the E(0(+)) - X(1)?(+) (1,0) band of thorium monoxide, ThO, was recorded and analyzed to determine the permanent electric dipole moments, ?, for the E(0(+)) (v = 1) and X(1)?(+) (v = 0) states. Values of 2.782 ± 0.012 D (X) and 3.534 ± 0.010 D (E) were obtained. The uncertainties are 2? statistical error. The systematic errors are estimated to be less than 1%. The experimental results are used to access the quality of electronic structure calculations of the properties of the X(1)?(+) (v = 0) state. PMID:21261322

Wang, Fang; Le, Anh; Steimle, Timothy C; Heaven, Michael C

2011-01-21

261

Design for a fountain of YbF molecules to measure the electron's electric dipole moment  

NASA Astrophysics Data System (ADS)

We propose an experiment to measure the electric dipole moment (EDM) of the electron using ultracold YbF molecules. The molecules are produced as a thermal beam by a cryogenic buffer gas source, and brought to rest in an optical molasses that cools them to the Doppler limit or below. The molecular cloud is then thrown upward to form a fountain in which the EDM of the electron is measured. A non-zero result would be unambiguous proof of new elementary particle interactions, beyond the standard model.

Tarbutt, M. R.; Sauer, B. E.; Hudson, J. J.; Hinds, E. A.

2013-05-01

262

Quantum electric dipoles in spin-liquid dimer Mott insulator ?-ET2Cu2(CN)3  

NASA Astrophysics Data System (ADS)

We present an effective dipolar-spin model based on the strong coupling analysis, which may explain the possible origin of “spin-liquid insulator.” The issue is related to a dimer Mott insulator reminiscent of an organic triangular lattice system, ?-ET2Cu2(CN)3 , whose gapless spin-liquid state has been discussed in the context of geometrical frustration of exchange coupling, J , between spins on dimer orbitals. It turns out that another degrees of freedom within the insulator, quantum electric dipoles on dimers, interact with each other and modify J significantly through the dipolar-spin coupling, resulting in a possible “dipolar-spin liquid.”

Hotta, Chisa

2010-12-01

263

Electron and neutron electric dipole moment in the 3-3-1 model with heavy leptons  

NASA Astrophysics Data System (ADS)

We calculate the electric dipole moment for the electron and neutron in the framework of the 3-3-1 model with heavy charged leptons. We assume that the only source of C P violation arises from a complex trilinear coupling constant and the three complex vacuum expectation values. However, two of the vacua phases are absorbed and the other two are equal up to a minus sign. Hence only one physical phase survives. In order to be compatible with the experimental data this phase has to be smaller than 1 0-6.

De Conto, G.; Pleitez, V.

2015-01-01

264

NUCLEAR AND HEAVY ION PHYSICS: Electric-dipole transitions in 165Er  

NASA Astrophysics Data System (ADS)

High-spin states of 165Er were studied using the 160Gd(9Be, 4n)reaction at beam energies of 42 and 45 MeV. The previously known bands based on the v5/2- [523] and v5/2+ [642] configurations have been extended to high-spin states. Electric-dipole transitions linking these two opposite parity bands were observed. Relatively large B(E1) values have been extracted experimentally and were attributed to octupole softness.

Wang, Shi-Tao; Zhou, Xiao-Hong; Zhang, Yu-Hu; Zheng, Yong; Liu, Min-Liang; Ma, Fei; Hu, Jun; Chen, Liang; Zhang, Xin; Zhang, Ning-Tao; Zhu, Li-Hua; Wu, Xiao-Guang; Li, Guang-Sheng

2009-08-01

265

Full 180° magnetization reversal with electric fields.  

PubMed

Achieving 180° magnetization reversal with an electric field rather than a current or magnetic field is a fundamental challenge and represents a technological breakthrough towards new memory cell designs. Here we propose a mesoscale morphological engineering approach to accomplishing full 180° magnetization reversals with electric fields by utilizing both the in-plane piezostrains and magnetic shape anisotropy of a multiferroic heterostructure. Using phase-field simulations, we examined a patterned single-domain nanomagnet with four-fold magnetic axis on a ferroelectric layer with electric-field-induced uniaxial strains. We demonstrated that the uniaxial piezostrains, if non-collinear to the magnetic easy axis of the nanomagnet at certain angles, induce two successive, deterministic 90° magnetization rotations, thereby leading to full 180° magnetization reversals. PMID:25512070

Wang, J J; Hu, J M; Ma, J; Zhang, J X; Chen, L Q; Nan, C W

2014-01-01

266

Full 180° Magnetization Reversal with Electric Fields  

NASA Astrophysics Data System (ADS)

Achieving 180° magnetization reversal with an electric field rather than a current or magnetic field is a fundamental challenge and represents a technological breakthrough towards new memory cell designs. Here we propose a mesoscale morphological engineering approach to accomplishing full 180° magnetization reversals with electric fields by utilizing both the in-plane piezostrains and magnetic shape anisotropy of a multiferroic heterostructure. Using phase-field simulations, we examined a patterned single-domain nanomagnet with four-fold magnetic axis on a ferroelectric layer with electric-field-induced uniaxial strains. We demonstrated that the uniaxial piezostrains, if non-collinear to the magnetic easy axis of the nanomagnet at certain angles, induce two successive, deterministic 90° magnetization rotations, thereby leading to full 180° magnetization reversals.

Wang, J. J.; Hu, J. M.; Ma, J.; Zhang, J. X.; Chen, L. Q.; Nan, C. W.

2014-12-01

267

Full 180° Magnetization Reversal with Electric Fields  

PubMed Central

Achieving 180° magnetization reversal with an electric field rather than a current or magnetic field is a fundamental challenge and represents a technological breakthrough towards new memory cell designs. Here we propose a mesoscale morphological engineering approach to accomplishing full 180° magnetization reversals with electric fields by utilizing both the in-plane piezostrains and magnetic shape anisotropy of a multiferroic heterostructure. Using phase-field simulations, we examined a patterned single-domain nanomagnet with four-fold magnetic axis on a ferroelectric layer with electric-field-induced uniaxial strains. We demonstrated that the uniaxial piezostrains, if non-collinear to the magnetic easy axis of the nanomagnet at certain angles, induce two successive, deterministic 90° magnetization rotations, thereby leading to full 180° magnetization reversals. PMID:25512070

Wang, J. J.; Hu, J. M.; Ma, J.; Zhang, J. X.; Chen, L. Q.; Nan, C. W.

2014-01-01

268

Electric Current Generated with a Moving Magnet  

NSDL National Science Digital Library

This is an activity about magnetic induction. Learners will induce a flow of electricity in a wire using a moving bar magnet and measure this flow using a galvanometer, or Am meter. Through discussion, this activity can then be related to magnetic fields in nature. This activity requires use of a galvanometer, bar or cow magnet, and wire. This is the fifth lesson in the second session of the Exploring Magnetism teacher guide.

269

A model of SVC radiation in magnetic dipole field and radiation varying with magnetic field. II - SVC radiation mechanism and radiation variation with magnetic field  

Microsoft Academic Search

The radio radiation and other radiative characteristics of the slowly varying component (SVC) are examined by means of a model of electron temperature and density and incorporating a dipole magnetic field. The model is based on recent EUV data regarding the chromosphere-corona transition region. The plasma electron temperature, density, and magnetic field are studied as a function of height above

Ren-Yang Zhao

1991-01-01

270

Cavity QED based on collective magnetic dipole coupling: spin ensembles as hybrid two-level systems.  

PubMed

We analyze the magnetic dipole coupling of an ensemble of spins to a superconducting microwave stripline structure, incorporating a Josephson junction based transmon qubit. We show that this system is described by an embedded Jaynes-Cummings model: in the strong coupling regime, collective spin-wave excitations of the ensemble of spins pick up the nonlinearity of the cavity mode, such that the two lowest eigenstates of the coupled spin wave-microwave cavity-Josephson junction system define a hybrid two-level system. The proposal described here enables new avenues for nonlinear optics using optical photons coupled to spin ensembles via Raman transitions. The possibility of strong coupling cavity QED with magnetic dipole transitions also opens up the possibility of extending quantum information processing protocols to spins in silicon or graphene, without the need for single-spin confinement. PMID:19257738

Imamo?lu, Atac

2009-02-27

271

Magnetic Field Mapping and Integral Transfer Function Matching of the Prototype Dipoles for the NSLS-II at BNL  

SciTech Connect

The National Synchrotron Light Source-II (NSLS-II) storage ring at Brookhaven National Laboratory (BNL) will be equipped with 54 dipole magnets having a gap of 35 mm, and 6 dipoles having a gap of 90 mm. Each dipole has a field of 0.4 T and provides 6 degrees of bending for a 3 GeV electron beam. The large aperture magnets are necessary to allow the extraction of long-wavelength light from the dipole magnet to serve a growing number of users of low energy radiation. The dipoles must not only have good field homogeneity (0.015% over a 40 mm x 20 mm region), but the integral transfer functions and integral end harmonics of the two types of magnets must also be matched. The 35 mm aperture dipole has a novel design where the yoke ends are extended up to the outside dimension of the coil using magnetic steel nose pieces. This design increases the effective length of the dipole without increasing the physical length. These nose pieces can be tailored to adjust the integral transfer function as well as the homogeneity of the integrated field. One prototype of each dipole type has been fabricated to validate the designs and to study matching of the two dipoles. A Hall probe mapping system has been built with three Group 3 Hall probes mounted on a 2-D translation stage. The probes are arranged with one probe in the midplane of the magnet and the others vertically offset by {+-}10 mm. The field is mapped around a nominal 25 m radius beam trajectory. The results of measurements in the as-received magnets, and with modifications made to the nose pieces are presented.

He, P.; Jain, A., Gupta, R., Skaritka, J., Spataro, C., Joshi, P., Ganetis, G., Anerella, M., Wanderer, P.

2011-03-28

272

Recent improvements in superconducting cable for accelerator dipole magnets  

SciTech Connect

The superconducting magnets required for the SSC have provided a focus and substantial challenge for the development of superconducting wire and cable. The number of strands in the cables have been increased from 23 for the Tevatron to 30 for the SSC inner layer cable and 36 for the SSC outer cable. Critical current degradation associated with cabling has been reduced from 15% for the Tevatron to less than 5%. R D which has led to these improvements will be described and the opportunities for further advances will be discussed. 11 refs., 2 figs., 1 tab.

Scanlan, R.M.; Royet, J.M.

1991-05-01

273

Strong bulk magnetic dipole induced second-harmonic generation from C60  

NASA Astrophysics Data System (ADS)

We describe how to separate all surface, interface, and bulk tensor components in optical second-harmonic generation experiments on isotropic thin films. Using in situ thickness scans and group theoretical arguments concerning the bulk tensor components, we demonstrate that the second-harmonic resonance of C60 at 2??=3.6 eV is of bulk character, and, quite remarkably, of magnetic dipole induced origin.

Koopmans, Bert; Janner, Anna-Maria; Jonkman, Harry T.; Sawatzky, George A.; van der Woude, Folkert

1993-11-01

274

Measurements of electron cloud growth and mitigation in dipole, quadrupole, and wiggler magnets  

NASA Astrophysics Data System (ADS)

Retarding field analyzers (RFAs), which provide a localized measurement of the electron cloud, have been installed throughout the Cornell Electron Storage Ring (CESR), in different magnetic field environments. This paper describes the RFA designs developed for dipole, quadrupole, and wiggler field regions, and provides an overview of measurements made in each environment. The effectiveness of electron cloud mitigations, including coatings, grooves, and clearing electrodes, are assessed with the RFA measurements.

Calvey, J. R.; Hartung, W.; Li, Y.; Livezey, J. A.; Makita, J.; Palmer, M. A.; Rubin, D.

2015-01-01

275

Cryostat design for the Superconducting Super Collider 50mm aperture dipole magnet  

SciTech Connect

The cryostat of an SSC dipole magnet consists of all magnet components except the cold mass assembly. It serves to support the cold mass accurately and reliably within the vacuum vessel, provide all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. It must function reliably during storage, shipping and handling, normal magnet operation, quenches, and seismic excitations and must be manufacturable at low cost. The major components of the cryostat are the vacuum vessel, thermal shields, multilayer insulation (MLI) system, cryogenic piping, interconnections, and suspension system. The overall design of a cryostat for superconducting accelerator magnets requires consideration of fluid flow, proper selection of materials for their thermal and structural performance at both ambient and operating temperature, and knowledge of the environment to which the magnets will be subjected over the course their 25 year expected life. This paper describes the design of the current SSC collider dipole magnet cryostat and includes discussions on the thermal, structural, and dynamic considerations involved in the development of each of the major systems. 7 refs., 1 fig., 2 tabs.

Nicol, T.H. (Fermi National Accelerator Lab., Batavia, IL (USA)); Tsavalas, Y.P. (General Electric Co., Florence, SC (USA). Medical Systems)

1990-09-01

276

Design study of 15-Tesla RHQT Nb3Al block type dipole magnet  

SciTech Connect

The design study of the block type 15-Tesla RHQT Nb{sub 3}Al dipole magnet, and its merits over Nb{sub 3}Sn magnets are presented. The copper stabilized RHQT Nb{sub 3}Al strand is now becoming commercially available for the application to the accelerator magnets. A 1 mm diameter RHQT Nb{sub 3}Al strand with filament size about 50 {mu}, non-copper Jc about 1000 A/mm{sup 2} at 15 Tesla at 4.2K, copper ratio of 50%, can now be produced over several hundred meters. The stress and strain characteristics of the Nb{sub 3}Al strand are superior to the Nb{sub 3}Sn strand. Another advantage is that it can tolerate a longitudinal strain up to 0.55%. The RHQT Nb{sub 3}Al Rutherford cable will have less chance of contamination of the stabilizer, compared to Nb{sub 3}Sn cable. These characteristics of the RHQT Nb{sub 3}Al will be beneficial for designing and producing 15-Tesla dipole magnets. An example 15-Tesla magnet cross section, utilizing the RHQT Nb{sub 3}Sn strand is presented. A systematic investigation on RHQT Nb{sub 3}Al strands, its Rutherford cables, and building a small racetrack magnet for cable testing are proposed.

Yamada, R.; Ambrosio, G.; Barzi, E.; Kashikin, V.; Kikuchi, A.; Novitski, I.; Takeuchi, T.; Wake, M.; Zlobin, A.; /Fermilab /NIMC, Tsukuba /KEK, Tsukuba

2005-09-01

277

A Mole for Warm Magnetic and Optical Measurements of LHC Dipoles  

E-print Network

A new rotating coil probe (a mole) has been developed for the simultaneous measurement of the magnetic field and magnetic axis of warm superconducting LHC dipoles and associated corrector windings. The mole houses a radial rotating coil and travels inside the magnet aperture by means of an externally driven two-way traction belt. The coil is rotated by an on-board piezo motor, being tested in view of future devices for cold measurements as the only type of motor compatible with strong magnetic fields. A virtual light spot is generated in the coil center by a LED source. The position of this light spot is measured from the outside by a system including a telescope, a CCD camera and a DSP. Jigs on reference granite tables are used to transfer the optical measurements to the magnet fiducials. We describe here the main characteristics and performance of the mole

Bottura, L; Deferne, G; Glöckner, C; Jansen, H; Köster, A; Legrand, P; Rijllart, A; Sievers, P

2000-01-01

278

Molecular Expressions: Electricity and Magnetism - Inductance  

NSDL National Science Digital Library

This interactive tutorial offers explanations and simulations of magnetic phenomena. Several simulations illustrate the principles of magnetic fields, Faraday's Law, self-inductance effects, and applications of inductance. The text describes the physics. This resource is part of a larger collection on electricity and magnetism by the same authors.

Davidson, Michael

2007-08-28

279

Magnetism and Electricity Activity "Attracts" Student Interest  

ERIC Educational Resources Information Center

Electricity and magnetism are intimately linked, this relationship forming the basis of the modern electric utility system and the generation of bulk electrical energy. There is rich literature from which to teach students the basics, but nothing drives the point home like having them learn from firsthand experience--and that is what this…

Roman, Harry T.

2010-01-01

280

Relativistic many-body analysis of the electric dipole moment of 223Rn  

NASA Astrophysics Data System (ADS)

We report the results of our ab initio relativistic many-body calculations of the electric dipole moment (EDM) dA arising from the electron-nucleus tensor-pseudotensor (T-PT) interaction, the interaction of the nuclear Schiff moment (NSM) with the atomic electrons and the electric dipole polarizability ?d for 223Rn . Our relativistic random-phase approximation results are substantially larger than those of lower-order relativistic many-body perturbation theory and the results based on the relativistic coupled-cluster method with single and double excitations are highly accurate for all three properties that we have considered. We obtain dA=4.85 (6 ) ×10-20 CT|e | cm from T-PT interaction, dA=2.89 (4 ) ×10-17S /(|e |fm3) from NSM interaction, and ?d=35.27 (9 ) e a03 . The former two results in combination with the measured value of 223Rn EDM, when it becomes available, could yield the best limits for the T-PT coupling constant, EDMs, and chromo-EDMs of quarks and ?QCD parameter, and would thereby shed light on leptoquark and supersymmetric models that predict C P violation.

Sahoo, B. K.; Singh, Yashpal; Das, B. P.

2014-11-01

281

Strong P invariance, neutron electric dipole moment, and minimal left-right parity at LHC  

NASA Astrophysics Data System (ADS)

In the minimal left-right model the choice of left-right symmetry is twofold: either generalized parity P or charge conjugation C . In the minimal model with spontaneously broken strict P , a large tree-level contribution to strong C P violation can be computed in terms of the spontaneous phase ? . Searches for the neutron electric dipole moments then constrain the size of ? . Following the latest update on indirect C P violation in the kaon sector, a bound on WR mass at 20 TeV is set. Possible ways out of this bound require a further hypothesis, either a relaxation mechanism or explicit breaking of P . To this end, the chiral loop of the neutron electric dipole moment at next-to-leading order is recomputed and provides an estimate of the weak contribution. Combining this constraint with other C P -violating observables in the kaon sector allows for MWR?3 TeV . On the other hand, C symmetry is free from such constraints, leaving the right-handed scale within the experimental reach.

Maiezza, Alessio; Nemevšek, Miha

2014-11-01

282

The Fermilab main injector dipole construction techniques and prototype magnet measurements  

SciTech Connect

The Fermilab Main Injector Project will provide 120--150 GeV Proton and Antiproton Beams for Fermilab Fixed Target Physics and Colliding Beams Physics use. A dipole magnet has been designed and prototypes constructed for the principal bending magnets of this new accelerator. The design considerations and fabrication techniques are described. Measurement results on prototypes are reported, emphasizing the field uniformity achieved in both body field and end field at excitation levels from injection at 0.1 T to full field of 1.7 T. 6 refs., 5 figs., 3 tabs.

Bleadon, M.; Brown, B.; Chester, N.; Desavouret, E.; Garvey, J.; Glass, H.; Harding, D.; Harfoush, F.; Holmes, S.; Humbert, J.; Kerby, J.; Knauf, A.; Kobliska, G.; Lipski, A.; Martin, P.; Mazur, P.; Orris, D.; Ostiguy, J.; Peggs, S.; Pachnik, J.; Pewitt, E.; Satti, J.; Schmidt, E.; Sim, J.; Snowdon, S.; Walbridge, D.

1991-09-01

283

A. C. losses in the SSC high energy booster dipole magnets  

SciTech Connect

The baseline design for the SSC High Energy Booster (HEB) has dipole bending magnets with a 50 mm aperture. An analysis of the cryogenic heat load due to A.C. losses generated in the HEB ramp cycle are reported for this magnet. Included in this analysis are losses from superconductor hysteresis, yoke hysteresis, strand eddy currents, and cable eddy currents. The A.C. loss impact of 2.5 {mu}m vs. 6 {mu}m filament conductor is presented. A 60 mm aperture design is also investigated. 8 refs., 3 tabs.

Jayakumar, R.; Kovachev, V.; Snitchler, G.; Orrell, D.

1991-06-01

284

Gadolinium Iron Garnet as a Solid State Material for an Electron Electric Dipole Moment Search  

E-print Network

The possibility of a solid state electron electric dipole moment (EDM) experiment based on Gadolinium Iron Garnet (GdIG) is investigated. GdIG appears to exhibit superparamagnetism and this effect can be used to enhance the electric-field-induced EDM signal at relatively a high temperatures, as compared to a simple paramagnetic system such as Gadolinium Gallium Garnet. The sensitivity of a GdIG based experiment might be large enough that an improvement by over three orders of magnitude, compared to the existing electron EDM limit, could be obtained at a modest temperature of 4 K, assuming that the superparamagnetic effect is not suppressed at this temperature, and that the spin relaxation time remains sufficiently rapid.

Steve K. Lamoreaux

2007-03-16

285

Gadolinium Iron Garnet as a Solid State Material for an Electron Electric Dipole Moment Search  

E-print Network

The possibility of a solid state electron electric dipole moment (EDM) experiment based on Gadolinium Iron Garnet (GdIG) is investigated. GdIG appears to exhibit superparamagnetism and this effect can be used to enhance the electric-field-induced EDM signal at relatively a high temperatures, as compared to a simple paramagnetic system such as Gadolinium Gallium Garnet. The sensitivity of a GdIG based experiment might be large enough that an improvement by over three orders of magnitude, compared to the existing electron EDM limit, could be obtained at a modest temperature of 4 K, assuming that the superparamagnetic effect is not suppressed at this temperature, and that the spin relaxation time remains sufficiently rapid.

Lamoreaux, S K

2007-01-01

286

SGR 0418+5729: A SMALL INCLINATION ANGLE RESULTING IN A NOT SO LOW DIPOLE MAGNETIC FIELD?  

SciTech Connect

The spin-down behaviors of SGR 0418+5729 are investigated. The pulsar spin-down model of Contopoulos and Spitkovsky is applied to SGR 0418+5729. It is shown that SGR 0418+5729 lies below the pulsar death line and its rotation-powered magnetospheric activities may therefore have stopped. The compact star is now spun down by the magnetic dipole moment perpendicular to its rotation axis. Our calculations show that under these assumptions there is the possibility of SGR 0418+5729 having a strong dipole magnetic field, if there is a small magnetic inclination angle. Its dipole magnetic field may be much higher than the characteristic magnetic field. Therefore, SGR 0418+5729 may be a normal magnetar instead of a low magnetic field magnetar.

Tong, H. [Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, Xinjiang 830011 (China); Xu, R. X. [School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China)

2012-09-20

287

Surveying Students' Conceptual Knowledge of Electricity and Magnetism.  

ERIC Educational Resources Information Center

Introduces the Conceptual Survey of Electricity and Magnetism (CSEM) which was developed to assess students' knowledge of topics in electricity and magnetism. Reports on the number of student difficulties in electricity and magnetism. (Contains 23 references.) (Author/YDS)

Maloney, David P.; O'Kuma, Thomas L.; Hieggelke, Curtis J.; Van Heuvelen, Alan

2001-01-01

288

Modeling the internal magnetic field of Mercury using the Time Dependent Equivalent Source Dipole method  

NASA Astrophysics Data System (ADS)

We model the internal magnetic field of Mercury as measured by the MESSENGER probe during its first year. We introduce a new modeling technique, the Time-Dependent Equivalent Source Dipole approach (TD-ESD). At a given location, the measured magnetic field is assumed to result from the sum of the contributions of individual dipoles located deep inside Mercury's interior which may vary with time to reflect the temporal variation of the Hermean magnetic field. We report first models computed with the TDESD method using only Mercury's sideral days separately. We discuss the time-evolution of the modeled field and compare it to the time-evolution of the residuals. There is a strong correlation between these two quantities, which confirms that external magnetic fields are somehow affecting the modeled, supposedly internal, field. We also compute a mean model using a complete solar day and find that most of the external fields are reduced. The mean magnetic equator at 200 km altitude is found at 10 N latitude on average, corresponding to a g02/g01 ratio of 0.28.

Oliveira, J. S.; Langlais, B.; Amit, H.; Pais, M. A.

2014-04-01

289

ECE 390 Electric & Magnetic Fields Catalog Description: Static and quasi-static electric and magnetic fields.  

E-print Network

electric fields in presence of material medium: conductors, dielectrics, polarization, electric fluxECE 390 ­ Electric & Magnetic Fields Catalog Description: Static and quasi-static electric), A. Jander (secondary) Course Content: · Introduction, review of vector analysis · Static electric

290

Electric control of magnetism at room temperature  

PubMed Central

In the single-phase multiferroics, the coupling between electric polarization (P) and magnetization (M) would enable the magnetoelectric (ME) effect, namely M induced and modulated by E, and conversely P by H. Especially, the manipulation of magnetization by an electric field at room-temperature is of great importance in technological applications, such as new information storage technology, four-state logic device, magnetoelectric sensors, low-power magnetoelectric device and so on. Furthermore, it can reduce power consumption and realize device miniaturization, which is very useful for the practical applications. In an M-type hexaferrite SrCo2Ti2Fe8O19, large magnetization and electric polarization were observed simultaneously at room-temperature. Moreover, large effect of electric field-controlled magnetization was observed even without magnetic bias field. These results illuminate a promising potential to apply in magnetoelectric devices at room temperature and imply plentiful physics behind them. PMID:22355737

Wang, Liaoyu; Wang, Dunhui; Cao, Qingqi; Zheng, Yuanxia; Xuan, Haicheng; Gao, Jinlong; Du, Youwei

2012-01-01

291

HD1: Design and Fabrication of a 16 Tesla Nb3Sn DipoleMagnet  

SciTech Connect

The Lawrence Berkeley National Laboratory (LBNL) Superconducting Magnet Group has completed the design, fabrication and test of HD1, a 16 T block-coil dipole magnet. State of the art Nb{sub 3}Sn conductor was wound in double-layer racetrack coils and supported by an iron yoke and a tensioned aluminum shell. In order to prevent conductor movement under magnetic forces up to the design field, a coil pre-stress of 150 MPa was required. To achieve this level without damaging the brittle conductor, the target stress was generated during cool-down to 4.2 K by exploiting the thermal contraction differentials between yoke and shell. Accurate control of the shell tension during assembly was obtained using pressurized bladders and interference load keys. An integrated 3D CAD model was used to optimize magnetic and mechanical design and analysis.

Hafalia, A.R.; Bartlett, S.E.; Capsi, S.; Chiesa, L.; Dietderich,D.R.; Ferracin, P.; Goli, M.; Gourlay, S.A.; Hannaford, C.R.; Highley,H.; Lietzke, A.F.; Liggins, N.; Mattafirri, S.; McInturff, A.D.; Nyman,M.; Sabbi, G.L.; Scanlan, R.M.; Swanson, J.

2003-11-10

292

Performance analysis of HD1: a 16 Tesla Nb3Sn dipole Magnet  

SciTech Connect

The Superconducting Magnet Group at Lawrence Berkeley National Laboratory (LBNL) has been developing technology for high field accelerator magnets from brittle conductors. HD1 is a single bore block dipole magnet using two, double-layer Nb{sub 3}Sn flat racetrack coils. The magnet was tested in October 2003 and reached a bore peak field of 16 T (94.5% of short sample). The average quench current plateau appeared to be limited by 'stick slip' conductor motions. Diagnostics recorded quench origins and preload distributions. Cumulative deformation of the mechanical structure has been observed. Quench velocity in different field regions has been measured and compared with model predictions. The results obtained during the HD1 test are presented and discussed.

Mattafirri, S.; Bartlett, S.E.; Bish, P.A.; Caspi, S.; Dietderich, D.R.; Ferracin, P.; Gourlay, S.A.; Hannaford, C.R.; Hafalia, A.R.; Lau, W.G.; Lietzke, A.F.; McInturff, A.D.; Nyman, M.; Sabbi, G.L.; Scanlan, R.M.

2005-06-01

293

Axial variations in the magnetic field of superconducting dipoles and quadrupoles  

SciTech Connect

A periodic variation in the magnetic field along the axis has been observed in both quadrupole and dipole magnets made from superconducting cable. This oscillation is present in all components of the field and has a wavelength equal to the transposition length of the cable. In general the amplitude of these variations increases with magnet current and is not reversible. The residual field patten at zero current depends on the energizing cycle and increases with time spent at high field. The decay of the oscillations has a complex time dependence which contains some extremely long time constants. Unbalanced currents in the individual strands of the cable appear to cause these effects and the field variations can only be completely erased by raising the magnet above its critical temperature.

Ghosh, A.K.; Robins, K.E.; Sampson, W.B.

1993-09-01

294

The dipole corrector magnets for the RHIC fast global orbit feedback system  

SciTech Connect

The recently completed RHIC fast global orbit feedback system uses 24 small 'window-frame' horizontal dipole correctors. Space limitations dictated a very compact design. The magnetic design and modelling of these laminated yoke magnets is described as well as the mechanical implementation, coil winding, vacuum impregnation, etc. Test procedures to determine the field quality and frequency response are described. The results of these measurements are presented and discussed. A small fringe field from each magnet, overlapping the opposite RHIC ring, is compensated by a correction winding placed on the opposite ring's magnet and connected in series with the main winding of the first one. Results from measurements of this compensation scheme are shown and discussed.

Thieberger, P.; Arnold, L.; Folz, C.; Hulsart, R.; Jain, A.; Karl, R.; Mahler, G.; Meng, W.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Ptitsyn, V.; Ritter, J.; Smart, L.; Tuozzolo, J.; White, J.

2011-03-28

295

Experimental determination of the magnetic dipole moment of candidate magnetoreceptor cells in trout  

NASA Astrophysics Data System (ADS)

Based on histological, physiological, and physical evidence, Walker et al (1997) and Diebel et al (2000) have identified distinctive cells in the olfactory epithelium of the rainbow trout (Onchorynchus mykiss) that contain magnetite and are closely associated with neurons that respond to changes in magnetic field. To put biophysical constraints on the possible transduction mechanism of magnetic signals, and in particular, to find out if the intracellular magnet is free to rotate or rather firmly anchored within the cell body, we have studied the magneto-mechanical response of isolated candidate receptor cells in suspension using a light microscope equipped with two pairs of Helmholtz coils. From the characteristic re-orientation time of suspended cells after a change in magnetic field direction, we have determined the magnitude of the magnetic dipole moment of the cells in function of the external field strength (0.4 mT to 3.2 mT) in order to find out whether or not the natural magnetic moment is remanence-based or induced (i.e., single-domain vs. superparamagnetic/multi-domain). Results: 1) The mechanical response of isolated cells to a change in magnetic field direction was always immediate, irrespective of the direction of change, which implies that the intracellular magnet is not free to rotate in the cell, but rather rigidly attached, probably to the plasma membrane, which is also suggested by our confocal fluorescence-microscope studies. 2) The cellular dipole moment turned out to be independent of the external field strength. Thus, the natural magnetic dipole moment is based on magnetic remanence, which points to single-domain particles and corroborates the results by Diebel et al (2000), who obtained switching fields consistent with single-domain magnetite. 3). The magnetic dipole moment is found to be of the order of several tens of fAm2, which greatly exceeds previous estimates (0.5 fAm2), and thus is similar to values reported for the most strongly magnetic types of magnetotactic bacteria (Hanzlik et al. 2002). Our results demonstrate that the magnetically identified cells clearly meet the physical requirements for a magnetoreceptor capable of rapidly detecting small changes in the external magnetic field. Diebel, C.E., Proksch, R., Green, C.R., Neilson, P. & Walker, M.M. (2000) Magnetite defines a vertebrate magnetoreceptor. Nature 406, 299-302. Hanzlik, M., Winklhofer, M., Petersen, N. (2002) Pulsed-field-remanence measurements on individual magnetotactic bacteria, J. Magn. Magn. Mater., 248(2), 258-267. Walker, M.M., Diebel, C.E., Haugh, C.V., Pankhurst, P.M., Montgomery, J.C. & Green, C.R. (1997) Structure and function of the vertebrate magnetic sense. Nature 390, 371-376.

Winklhofer, M.; Eder, S.; Cadioiu, H.; McNaughton, P. A.; Kirschvink, J. L.

2011-12-01

296

Risk Assessment of the Chopper Dipole Kicker Magnets for the MedAustron Facility  

E-print Network

The MedAustron facility, to be built in Wiener Neustadt (Austria), will provide protons and ions for both cancer therapy and research [1]. Different types of kicker magnets will be used in the accelerator complex, including fast beam chopper dipoles: these allow the beam to be switched on and off for routine operational reasons or in case of emergency. Main requirements for the beam chopper system are safety and reliability. A criticality analysis, to chart the probability of failure modes against the severity of their consequences of the fault, has been carried out for the chopper dipole system. This "Failure Mode, Effects, and Criticality Analysis" (FMECA), has been used to highlight failure modes with relatively high probability and severity of consequences: conservative ratings of critical components and appropriate redundancy, together with measurements and interlocks, have been used to reduce the probability and criticality of faults. This paper gives an overview of the Risk Assessment approach and pres...

Kramer, T; Barnes, M J; Benedikt, M; Fowler, T

2011-01-01

297

Permanent Electric Dipole Moment of Strontium Monofluoride as a Test of the Accuracy of a Relativistic Coupled Cluster Method  

E-print Network

The permanent electric dipole moment of the X 2 {\\Sigma}+ electronic ground state of the strontium monofluoride molecule is calculated using a relativistic coupled cluster method. Our result is compared with those of other calculations and that of experiment. Individual contributions arising from different physical effects are presented. The result obtained suggests that the relativistic coupled cluster method used in the present work is capable of yielding accurate results for the permanent electric dipole moments of molecules for which relativistic effects cannot be ignored.

Prasannaa, V S; Das, B P

2014-01-01

298

Bound on the anomalous tbW coupling from two-loop contribution to neutron electric dipole moment  

NASA Astrophysics Data System (ADS)

The two-loop contribution to the electric dipole moment (EDM) and the chromo-electric dipole moment (CEDM) of an arbitrary fermion f induced by the most general renormalizable tbW coupling with complex left- and right-handed components ( a and a) is calculated. The analytical expressions are numerically evaluated and the current experimental constraints on the electron, neutron and mercury atom EDMs are used to obtain a bound on the complex phase Im(aL?a). It is found that the most stringent constraint, Im(aL?a)<2.33×10, arises from the neutron EDM.

Avilez-López, A.; Novales-Sánchez, H.; Tavares-Velasco, G.; Toscano, J. J.

2007-09-01

299

Spectrum of relativistic radiation from electric charges and dipoles as they fall freely into a black hole  

SciTech Connect

The motion of electric charges and dipoles falling radially and freely into a Schwarzschild black hole is considered. The inverse effect of the electromagnetic fields on the black hole is neglected. Since the dipole is assumed to be a point particle, the deformation due to the action of tidal forces on it is neglected. According to the theorem stating that 'black holes have no hair', the multipole electromagnetic fields should be completely radiated as a multipole falls into a black hole. The electromagnetic radiation power spectrum for these multipoles (a monopole and a dipole) has been found. Differences have been found in the spectra for different orientations of the falling dipole. A general method has been developed to find the radiated multipole electromagnetic fields for multipoles (including higher-order multipoles-quadrupoles, etc.) falling freely into a black hole. The calculated electromagnetic spectra can be compared with observational data from stellar-mass and smaller black holes.

Shatskiy, A. A., E-mail: shatskiy@asc.rssi.ru; Novikov, I. D.; Lipatova, L. N. [Russian Academy of Sciences, Astrospace Center, Lebedev Physical Institute (Russian Federation)

2013-06-15

300

Combined Panofsky Quadrupole & Corrector Dipole  

SciTech Connect

Two styles of Panofsky Quadrupoles with integral corrector dipole windings are in use in the electron beam line of the Free Electron Laser at Jefferson Lab. We combined steering and focusing functions into single magnets, adding hundreds of Gauss-cm dipole corrector capability to existing quadrupoles because space is at a premium along the beam line. Superposing a one part in 100 dipole corrector field on a 1 part in 1000, weak (600 to 1000 Gauss) quadrupole is possible because the parallel slab iron yoke of the Panofsky Quadrupole acts as a window frame style dipole yoke. The dipole field is formed when two electrically floating “current sources”, designed and made at JLab, add and subtract current from the two opposite quadrupole current sheet windings parallel to the dipole field direction. The current sources also drive auxiliary coils at the yoke’s inner corners that improve the dipole field. Magnet measurements yielded the control system field maps that characterize the two types of fields. Field analysis using TOSCA, construction and wiring details, magnet measurements and reference for the current source are presented.

George Biallas; Nathan Belcher; David Douglas; Tommy Hiatt; Kevin Jordan

2007-07-02

301

Are you positive? Electric dipole polarity discrimination in the yellow stingray, Urobatis jamaicensis.  

PubMed

It is well established that elasmobranchs can detect dipole electric fields. However, it is unclear whether they can discriminate between the anode and cathode. To investigate this subject, we employed a behavioral assay to determine the discriminatory ability of the yellow stingray, Urobatis jamaicensis. We conditioned stingrays with food rewards to bite either the anode (n=5) or the cathode (n=6) of a direct-current dipole located on the floor of an experimental tank. All individuals successfully performed the task after 18 to 22 days. Stingrays were then tested in experimental sessions when they were rewarded only after they identified the correct pole. Stingrays successfully discriminated between the poles at a rate greater than chance, ranging among individuals from a mean of 66% to 93% correct. During experimental sessions, stingrays conditioned to distinguish the anode performed similarly to those conditioned to distinguish the cathode. We hypothesize that the ability to discriminate anode from cathode is physiologically encoded, but its utility in providing spatial information under natural conditions remains to be demonstrated. The ability to discriminate polarity may eliminate ambiguity in induction-based magnetoreception and facilitate navigation with respect to the geomagnetic field. PMID:24243961

Siciliano, Avery M; Kajiura, Stephen M; Long, John H; Porter, Marianne E

2013-10-01

302

Can (electric-magnetic) duality be gauged?  

SciTech Connect

There exists a formulation of the Maxwell theory in terms of two vector potentials, one electric and one magnetic. The action is then manifestly invariant under electric-magnetic duality transformations, which are rotations in the two-dimensional internal space of the two potentials, and local. We ask the question: Can duality be gauged? The only known and battle-tested method of accomplishing the gauging is the Noether procedure. In its decanted form, it amounts to turning on the coupling by deforming the Abelian gauge group of the free theory, out of whose curvatures the action is built, into a non-Abelian group which becomes the gauge group of the resulting theory. In this article, we show that the method cannot be successfully implemented for electric-magnetic duality. We thus conclude that, unless a radically new idea is introduced, electric-magnetic duality cannot be gauged. The implication of this result for supergravity is briefly discussed.

Bunster, Claudio [Centro de Estudios Cientificos (CECS), Casilla 1469, Valdivia (Chile); Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Muehlenberg 1, D-14476 Potsdam (Germany); Henneaux, Marc [Centro de Estudios Cientificos (CECS), Casilla 1469, Valdivia (Chile); Universite Libre de Bruxelles and International Solvay Institutes, ULB-Campus Plaine CP231, B-1050 Brussels (Belgium); Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Muehlenberg 1, D-14476 Potsdam (Germany)

2011-02-15

303

Surface temperature of a magnetized neutron star and interpretation of the ROSAT data. 1: Dipole fields  

NASA Technical Reports Server (NTRS)

We model the temperature distribution at the surface of a magnetized neutron star and study the effects on the observed X-ray spectra and light curves. Generalrelativistic effects, i.e., redshift and lensing, are fully taken into account. Atmospheric effects on the emitted spectral flux are not included: we consider only blackbody emission at the local effective temperature. In this first paper we restrict ourselves to dipole fields. General features are studied and compared with the ROSAT data from the pulsars 0833 - 45 (Vela), 0656 + 14, 0630 + 178 (Geminga), and 1055 - 52, the four cases for which there is strong evidence that thermal radiation from the stellar surface is detected. The composite spectra we obtain are not very different from a blackbody spectrum at the star's effective temperature. We conclude that, as far as blackbody spectra are considered, temperature estimates using single-temperature models give results practically identical to our composite models. The change of the (composite blackbody) spectrum with the star's rotational phase is also not very large and may be unobservable inmost cases. Gravitational lensing strongly suppresses the light curve pulsations. If a dipole field is assumed, pulsed fractions comparable to the observed ones can be obtained only with stellar radii larger than those which are predicted by current models of neutron star struture, or with low stellar masses. Moreover, the shapes of the theoretical light curves with dipole fields do not correspond to the observations. The use of magnetic spectra may raise the pulsed fraction sufficiently but will certainly make the discrepancy with the light curve shapes worse: dipole fields are not sufficient to interpret the data. Many neutron star models with a meson condensate or hypersons predict very small radii, and hence very strong lensing, which will require highly nondipolar fields to be able to reproduce the observed pulsed fractions, if possible at all: this may be a new tool to constrain the size of neutron stars. The pulsed fractions obtained in all our models increase with photon energy: the strong decrease observed in Geminga at energies 0.3-0.5 keV is definitely a genuine effect of the magnetic field on the spectrum in contradistinction to the magnetic effects on the surface temperature considered her. Thus, a detailed analysis of thermal emission from the four pulsars we consider will require both complex surface field configurations and the inclusion of magnetic effects in the atmosphere (i.e., on the emitted spectrum).

Page, Dany

1995-01-01

304

Mississippi State Physics Labs: Electricity and Magnetism  

NSDL National Science Digital Library

This item is an introductory lab that examines several aspects of electricity and magnetism. The lab contains three sections that explore the basic properties of magnets, how electromagnets work, how simple electric motors work, and a take home activity in which students create a circuit diagram of their home. Materials are inexpensive and readily available. This item is part of a larger collection of online physics labs by the authors.

Ferguson, Joe; Denson, Jack

2008-01-26

305

Design, Fabrication, and Test of a Superconducting Dipole Magnet Based on Tilted Solenoids  

SciTech Connect

It can be shown that, by superposing two solenoid-like thin windings that are oppositely skewed (tilted) with respect to the bore axis, the combined current density on the surface is 'cos-theta' like and the resulting magnetic field in the bore is a pure dipole. As a proof of principle, such a magnet was designed, built and tested as part of a summer undergraduate intern project. The measured field in the 25mm bore, 4 single strand layers using NbTi superconductor, exceeded 1 T. The simplicity of this high field quality design, void of typical wedges end-spacers and coil assembly, is especially suitable for insert-coils using High Temperature Superconducting wire as well as for low cost superconducting accelerator magnets for High Energy Physics. Details of the design, construction and test are reported.

Caspi, S.; Dietderich, D. R.; Ferracin, P.; Finney, N. R.; Fuery, M. J.; Gourlay, S. A.; Hafalia, A. R.

2007-06-01

306

Enhanced electric dipole moment of the muon in the presence of large neutrino mixing  

PubMed

The electric dipole moment (edm) of the muon ( d(e)(&mgr;)) is evaluated in supersymmetric models with nonzero neutrino masses and large neutrino mixing arising from the seesaw mechanism. It is found that if the seesaw mechanism is embedded in the framework of a left-right symmetric gauge structure, the interactions responsible for the right-handed neutrino Majorana masses lead to an enhancement in d(e)(&mgr;) to values as large as 5x10(-23)e cm, with a correlated value of (g-2)(&mgr;) approximately 13x10(-10). This should provide a strong motivation for improving the edm of the muon to the level of 10(-24)e cm as has recently been proposed. PMID:11102187

Babu; Dutta; Mohapatra

2000-12-11

307

Precision Measurement of the Electric Dipole Intercombination Rate in C{sup 2+}  

SciTech Connect

The electric dipole intercombination decay of the 2s2p {sup 3}P{sup 0}{sub 1} level in the Be-like ion C{sup 2+} has been optically observed with ions circulating in a heavy-ion storage ring. The measured transition probability of (102.94{plus_minus}0.14) s{sup -1} , corresponding to a lifetime of (9.714{plus_minus}0.013) ms, is in good agreement with recent theoretical calculations. This precision measurement thus resolves the long-standing discrepancy of data from a radiofrequency ion trap experiment with theoretical predictions. {copyright} {ital 1997} {ital The American Physical Society}

Doerfert, J.; Traebert, E. [Experimentalphysik III, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)] [Experimentalphysik III, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Wolf, A.; Schwalm, D. [Physikalisches Institut der Universitaet Heidelberg ,D-69120 Heidelberg, Germany, and Max-Planck-Institut fuer Kernphysik, D-69117 Heidelberg (Germany)] [Physikalisches Institut der Universitaet Heidelberg ,D-69120 Heidelberg, Germany, and Max-Planck-Institut fuer Kernphysik, D-69117 Heidelberg (Germany); Uwira, O. [Strahlenzentrum der Justus-Liebig-Universitaet, D-35392 Giessen (Germany)] [Strahlenzentrum der Justus-Liebig-Universitaet, D-35392 Giessen (Germany)

1997-06-01

308

Electric Dipole Moments in Radioactive Nuclei, Tests of Time Reversal Symmetry  

NASA Astrophysics Data System (ADS)

The research of radioactive nuclei opens new possibilities to study fundamental symmetries, such as time reversal and reflection symmetry. Such nuclei often provide conditions to check in an optimal way certain symmetries and the violation of such symmetries. We will discuss the possibility of obtaining improved limits on violation of time reversal symmetry using pear shaped radioactive nuclei. An effective method to test time reversal invariance in the non-strange sector is to measure parity and time reversal violating (T-P-odd) electromagnetic moments, (such as the static electric dipole moment). Parity and time reversal violating components in the nuclear force may produce P-T-odd moments in nuclei which in turn induce such moments in atoms. We will discuss the possibility that in some reflection asymmetric, heavy nuclei (which are radioactive) these moments are enhanced by several orders of magnitude. Present and future experiments, which will test this idea, will be mentioned.

Auerbach, N.

2010-11-01

309

Electric Dipole Moments in Radioactive Nuclei, Tests of Time Reversal Symmetry  

SciTech Connect

The research of radioactive nuclei opens new possibilities to study fundamental symmetries, such as time reversal and reflection symmetry. Such nuclei often provide conditions to check in an optimal way certain symmetries and the violation of such symmetries. We will discuss the possibility of obtaining improved limits on violation of time reversal symmetry using pear shaped radioactive nuclei. An effective method to test time reversal invariance in the non-strange sector is to measure parity and time reversal violating (T-P-odd) electromagnetic moments, (such as the static electric dipole moment). Parity and time reversal violating components in the nuclear force may produce P-T-odd moments in nuclei which in turn induce such moments in atoms. We will discuss the possibility that in some reflection asymmetric, heavy nuclei (which are radioactive) these moments are enhanced by several orders of magnitude. Present and future experiments, which will test this idea, will be mentioned.

Auerbach, N. [School of Physics and Astronomy, Tel Aviv University, Tel Aviv, 69978 (Israel)

2010-11-24

310

Microgravity Electron Electric Dipole Moment Experiment with a Cold Atom Beam  

NASA Technical Reports Server (NTRS)

New physics beyond the Standard Model: The small CP violation contained in the Standard Model is insufficient to account for the baryon/antibaryon asymmetry in the universe. New sources of CP violation are provided by extensions to the Standard Model. They contain CP-violating phases that couple directly to leptons and from which a large electron electric dipole moment (EDM) may be generated. Observation of an electron EDM would be proof of a Standard Model extension because the Standard Model only allows an electron EDM of less than 10(exppp -57) C-m (S.I. units; 1 C-m = 1.6 x 10(exp -21) e-cm). A null result, however, constrains models and improving the limit tightens constraints, further restricting the models.

Gould, Harvey

2003-01-01

311

Electric-dipole 5s - 5p Transitions in Promethiumlike Ions  

SciTech Connect

The 5s-5p electric-dipole resonance transitions in highly ionized promethiumlike ions have been studied applying relativistic multi-reference Moeller-Plesset second-order perturbation theory. The transition wavelengths are determined to within 0.2 {angstrom} in the more highly charged ions, where the level degeneracies are small. For somewhat lighter ions a very large reference space was used in order to account for the many degeneracies. In order to calculate transition probabilities and lifetimes, correlation corrections have been added to the transition operator in the next order. The contributions from the higher orders of the theory, that is, frequency-dependent Breit correction, Lamb shift, and mass shifts, have been estimated. The results are used to re-assess spectroscopic data from beam-foil, electron beam ion trap, and tokamak observations.

Vilkas, M J; Ishikawa, Y; Trabert, E

2008-02-29

312

Electromagnetic field of a vertical electric dipole on a perfect conductor coated with a dielectric layer  

NASA Astrophysics Data System (ADS)

The simple asymptotic analytical expressions of the electromagnetic fields induced by a vertical electric dipole on a perfect conductor coated with a dielectric layer have been obtained. These expressions show that the induced fields consist of the direct wave, reflected wave, lateral wave and trapped surface wave. The propagation wave number of the trapped surface wave is between that of the wave number k0 in the air and the wave number k1 in the dielectric. The amplitude of the trapped surface wave attenuates as ?-1/2 in the ? direction near the surface and attenuates exponentially as e-?z in the z direction. The expressions for the direct wave, reflected wave and lateral wave in this paper coincide with those given by King and Sandler [1994]. When the thickness of the dielectric layer is not small, the lateral wave and the trapped surface wave are combined the total field to produce an interference pattern.

Zhang, Hong-qi; Pan, Wei-yan

2002-08-01

313

D vs d: CP Violation in Beta Decay and Electric Dipole Moments  

E-print Network

The T-odd correlation coefficient D in nuclear beta decay probes CP violation in many theories beyond the Standard Model. We provide an analysis for how large D can be in light of constraints from electric dipole moment (EDM) searches. We argue that the neutron EDM d_n currently provides the strongest constraint on D, which is 10 - 10^3 times stronger than current direct limits on D (depending on the model). In particular, contributions to D in leptoquark models (previously regarded as "EDM safe") are more constrained than previously thought. Bounds on D can be weakened only by fine-tuned cancellations or if theoretical uncertainties are larger than estimated in d_n. We also study implications for D from mercury and deuteron EDMs.

John Ng; Sean Tulin

2011-11-02

314

Measurement of the electron electric dipole moment using YbF molecules.  

PubMed

The most sensitive measurements of the electron electric dipole moment d(e) have previously been made using heavy atoms. Heavy polar molecules offer a greater sensitivity to d(e) because the interaction energy to be measured is typically 10(3) times larger than in a heavy atom. We have used YbF to make the first measurement of this kind. Together, the large interaction energy and the strong tensor polarizability of the molecule make our experiment essentially free of the systematic errors that currently limit d(e) measurements in atoms. Our first result d(e) = (-0.2+/-3.2)x10(-26)e cm is less sensitive than the best atom measurement but is limited only by counting statistics and demonstrates the power of the method. PMID:12096992

Hudson, J J; Sauer, B E; Tarbutt, M R; Hinds, E A

2002-07-01

315

Possible Search for the Electric Dipole Moment of the Electron in an Electrostatic Storage Ring  

NASA Astrophysics Data System (ADS)

A non-zero permanent electric dipole moment (EDM) of an electron would violate parity and time-reversal symmetries. Non-zero EDMs are predicted in the Standard Model, but are unobservably small. New physics incorporating new particles and new CP-violating phases can lead, through radiative corrections, to dramatic enhancements of the electron EDM, to within a few orders of magnitude of the current experimental limit, |de|<1.0x10-27 e cm. A possible new approach to electron EDM searches using molecular ions stored in a table-top electrostatic storage ring is described. Molecular ions with long-lived paramagnetic states such as WN^+ could be injected and stored in large numbers and with long coherence times. Sensitivities approaching a few x10-30 e cm/?day, appear possible, a potential improvement by three orders of magnitude.

Kawall, David

2011-11-01

316

Large electron electric dipole moment in minimal flavor violation framework with Majorana neutrinos  

NASA Astrophysics Data System (ADS)

The latest data from the ACME Collaboration have put a stringent constraint on the electric dipole moment de of the electron. Nevertheless, the standard model (SM) prediction for de is many orders of magnitude below the new result, making this observable a powerful probe for physics beyond the SM. We carry out a model-independent study of de in the SM with right-handed neutrinos and its extension with the neutrino seesaw mechanism under the framework of minimal flavor violation. We find that de crucially depends on whether neutrinos are Dirac or Majorana particles. In the Majorana case, de can reach its experimental bound, and it constrains the scale of minimal flavor violation to be above a few hundred GeV or more. We also explore extra CP-violating sources in the Yukawa couplings of the right-handed neutrinos. Such new sources can have important effects on de.

He, Xiao-Gang; Lee, Chao-Jung; Li, Siao-Fong; Tandean, Jusak

2014-05-01

317

Improving Students' Understanding of Electricity and Magnetism  

NSDL National Science Digital Library

Electricity and magnetism are important topics in physics. Research shows that students have many common difficulties in understanding concepts related to electricity and magnetism. However, research to improve studentsâ understanding of electricity and magnetism is limited compared to introductory mechanics. This thesis explores issues related to studentsâ common difficulties in learning some topics in electricity and magnetism and how these difficulties can be reduced by research-based learning tutorials. We investigated studentsâ difficulties in solving problems involving light bulbs and equations involving circuit elements. We administered multiple choice questions and essay questions to many classes and conducted individual interviews with a subset of students. Based on these investigations, we provide suggestions to improve learning. We also developed and evaluated five tutorials on Coulombâs law, Gaussâs law and the superposition principle to help students build a robust knowledge structure and firm understanding of these concepts. Studentsâ performance on the corresponding pre- and post-tests indicates that these tutorials effectively improved their understanding. We also designed a Magnetism Conceptual Survey (MCS) that can help instructors probe studentsâ understanding of magnetism concepts. The validity and reliability of this MCS is discussed. The performance of students from different groups (e.g. female students vs. male students, calculus-based students vs. algebra-based students) was compared. We also compare the MCS and the Conceptual Survey of Electricity and Magnetism (CSEM) on common topics.

Li, Jing

2012-04-21

318

Field-theory calculation of the electric dipole moment of the neutron and paramagnetic atoms  

E-print Network

Electric dipole moments (edms) of bound states that arise from the constituents having edms are studied with field-theoretic techniques. The systems treated are the neutron and a set of paramagnetic atoms. In the latter case it is well known that the atomic edm differs greatly from the electron edm when the internal electric fields of the atom are taken into account. In the nonrelativistic limit these fields lead to a complete suppression, but for heavy atoms large enhancement factors are present. A general bound-state field theory approach applicable to both the neutron and paramagnetic atoms is set up. It is applied first to the neutron, treating the quarks as moving freely in a confining spherical well. It is shown that the effect of internal electric fields is small in this case. The atomic problem is then revisited using field-theory techniques in place of the usual Hamiltonian methods, and the atomic enhancement factor is shown to be consistent with previous calculations. Possible application of bound-state techniques to other sources of the neutron edm is discussed.

S. A. Blundell; J. Griffith; J. Sapirstein

2012-05-10

319

Magnetic dipole moment of 57,59Cu measured by in-gas-cell laser spectroscopy  

E-print Network

In-gas-cell laser spectroscopy study of the 57,59,63,65Cu isotopes has been performed for the first time using the 244.164 nm optical transition from the atomic ground state of copper. The nuclear magnetic dipole moments for 57,59,65Cu relative to that of 63Cu have been extracted. The new value for 57Cu of mu(57Cu) = +2.582(7)mu_N is in strong disagreement with the previous literature value but in good agreement with recent theoretical and systematic predictions.

T. E. Cocolios; A. N. Andreyev; B. Bastin; N. Bree; J. Buscher; J. Elseviers; J. Gentens; M. Huyse; Yu. Kudryavtsev; D. Pauwels; T. Sonoda; P. Van den Bergh; P. Van Duppen

2009-06-16

320

Temperature-dependent terahertz magnetic dipole radiation from antiferromagnetic GdFeO{sub 3} ceramics  

SciTech Connect

Temperature-dependent terahertz magnetic dipole radiation in antiferromagnetic GdFeO{sub 3} ceramic is investigated both theoretically and experimentally in this work. A two-level quantum transition mechanism is introduced to describe the excitation-radiation process, and radiative lifetime is derived analytically from the change of spin state density during this process. Terahertz spectral measurements demonstrate that the radiative frequency exhibits a red-shift and lifetime shortens as temperature increases, which is in good agreement with theoretical predictions. The temperature-sensitive radiative frequency and excellent terahertz emission mean that the antiferromagnetic ceramics show potential for application in terahertz sensors and frequency-tunable terahertz lasers.

Fu, Xiaojian; Xi, Xiaoqing; Bi, Ke; Zhou, Ji, E-mail: zhouji@mail.tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)] [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

2013-11-18

321

Electron Affinities, Magnetic Dipole Decay Rates, and Hyperfine Structure for Sn^- 5p^3 Excited States  

NASA Astrophysics Data System (ADS)

Theoretical results have been computed to complement recent measurements by Scheer et al (Bull. Am. Phys. Soc. 42), 1026 (1997) which yielded electron affinities of excited states of the ground configuration of Sn^-. Our relativistic configuration interaction (RCI) values for the position of the excited Sn^- with respect to the negative ion ground state are EA(^2D_3/2) = 5903 cm-1 (0.732 eV), EA(^2D_5/2) = 6493 cm-1 (0.805 eV). Triple excitations make a significant contribution. Magnetic dipole hyperfine structure (hfs) constants (A) and M1 transition probabilities are also reported.

O'Malley, Steven M.; Beck, Donald R.

1998-05-01

322

Relaxation oscillations of Zeeman and dipole magnetizations of a paramagnet under conditions of deep low-frequency modulation  

E-print Network

The relaxation oscillations of Zeeman and dipole magnetizaions in spin system of a solid paramagnet are theoretically analyzed under conditions of intermediate saturation of magnetic resonance and strong low-frequency modulation of the external magnetic field. Peculiarities of the relaxation oscillations in the synchronous detection regime are considered.

M. D. Zviadadze; A. G. Kvirikadze; R. L. Lepsveridze; G. I. Mamniashvili; N. M. Sozashvili

2006-10-08

323

Optical spectroscopy of single Si nanocylinders with magnetic and electric resonances  

PubMed Central

Resonant electromagnetic properties of nanoparticles fabricated from high-index semiconductor or dielectric materials are very promising for the realization of novel nanoantennas and metamaterials. In this paper we study optical resonances of Si nanocylinders located on a silica substrate. Multipole analysis of the experimental scattering spectra, based on the decomposed discrete dipole approximation, confirms resonant excitation of electric and magnetic dipole modes in the Si nanocylinders. Influences of light polarization and incident angle on the scattering properties of the nanocylinders are studied. It is shown that the dependence of resonant excitation of the electric and magnetic modes in the nanocylinders on incident angle and polarization of light allows controlling and manipulating the scattered light in this system. The demonstrated properties of Si nanocylinders can be used for the realization of dielectric metasurfaces with different functional optical properties. PMID:24535224

Evlyukhin, Andrey B.; Eriksen, René L.; Cheng, Wei; Beermann, Jonas; Reinhardt, Carsten; Petrov, Alexander; Prorok, Stefan; Eich, Manfred; Chichkov, Boris N.; Bozhevolnyi, Sergey I.

2014-01-01

324

Using the History of Electricity and Magnetism To Enhance Teaching.  

ERIC Educational Resources Information Center

Explains the properties of charged objects, the nature of an electric charge, and interactions between electricity and magnetism. Suggests that the development of modern ideas about electricity and magnetism were not a linear progression. (Contains 34 references.) (Author/YDS)

Binnie, Anna

2001-01-01

325

Evaluating an Electricity and Magnetism Assessment Tool: Brief Electricity and Magnetism Assessment  

ERIC Educational Resources Information Center

The Brief Electricity and Magnetism Assessment (BEMA), developed by Chabay and Sherwood, was designed to assess student understanding of basic electricity and magnetism concepts covered in college-level calculus-based introductory physics courses. To evaluate the reliability and discriminatory power of this assessment tool, we performed…

Ding, Lin; Chabay, Ruth; Beichner, Robert

2006-01-01

326

Correlation of superparamagnetic relaxation with magnetic dipole interaction in capped iron-oxide nanoparticles  

NASA Astrophysics Data System (ADS)

Six nanometer sized iron-oxide nanoparticles capped with an organic surfactant and/or silica shell of various thicknesses have been synthesized by a microemulsion method to enable controllable contributions of interparticle magnetic dipole interaction via tunable interparticle distances. Bare particles with direct surface contact were used as a reference to distinguish between interparticle interaction and surface effects by use of Mössbauer spectroscopy. Superparamagnetic relaxation behaviour was analyzed by SQUID-magnetometry techniques, showing a decrease of the blocking temperature with decreasing interparticle interaction energies kBT0 obtained by AC susceptibility. A many-state relaxation model enabled us to describe experimental Mössbauer spectra, leading to an effective anisotropy constant Keff ? 45 kJm?3 in case of weakly interacting particles, consistent with results from ferromagnetic resonance. Our unique multi-technique approach, spanning a huge regime of characteristic time windows from about 10 s to 5 ns, provides a concise picture of the correlation of superparamagnetic relaxation with interparticle magnetic dipole interaction.

Landers, J.; Stromberg, F.; Darbandi, M.; Schöppner, C.; Keune, W.; Wende, H.

2015-01-01

327

Correlation of superparamagnetic relaxation with magnetic dipole interaction in capped iron-oxide nanoparticles.  

PubMed

Six nanometer sized iron-oxide nanoparticles capped with an organic surfactant and/or silica shell of various thicknesses have been synthesized by a microemulsion method to enable controllable contributions of interparticle magnetic dipole interaction via tunable interparticle distances. Bare particles with direct surface contact were used as a reference to distinguish between interparticle interaction and surface effects by use of Mössbauer spectroscopy. Superparamagnetic relaxation behaviour was analyzed by SQUID-magnetometry techniques, showing a decrease of the blocking temperature with decreasing interparticle interaction energies kBT0 obtained by AC susceptibility. A many-state relaxation model enabled us to describe experimental Mössbauer spectra, leading to an effective anisotropy constant Keff ? 45 kJm(-3) in case of weakly interacting particles, consistent with results from ferromagnetic resonance. Our unique multi-technique approach, spanning a huge regime of characteristic time windows from about 10 s to 5 ns, provides a concise picture of the correlation of superparamagnetic relaxation with interparticle magnetic dipole interaction. PMID:25502104

Landers, J; Stromberg, F; Darbandi, M; Schöppner, C; Keune, W; Wende, H

2015-01-21

328

Measurement of permanent electric dipole moments of charged hadrons in storage rings  

NASA Astrophysics Data System (ADS)

Permanent Electric Dipole Moments (EDMs) of elementary particles violate two fundamental symmetries: time reversal invariance ({T}) and parity ({P}). Assuming the {CPT} theorem this implies {CP} violation. The {CP} violation of the Standard Model is orders of magnitude too small to be observed experimentally in EDMs in the foreseeable future. It is also way too small to explain the asymmetry in abundance of matter and anti-matter in our universe. Hence, other mechanisms of {CP} violation outside the realm of the Standard Model are searched for and could result in measurable EDMs. Up to now most of the EDM measurements were done with neutral particles. With new techniques it is now possible to perform dedicated EDM experiments with charged hadrons at storage rings where polarized particles are exposed to an electric field. If an EDM exists the spin vector will experience a torque resulting in change of the original spin direction which can be determined with the help of a polarimeter. Although the principle of the measurement is simple, the smallness of the expected effect makes this a challenging experiment requiring new developments in various experimental areas. Complementary efforts to measure EDMs of proton, deuteron and light nuclei are pursued at Brookhaven National Laboratory and at Forschungszentrum Jülich with an ultimate goal to reach a sensitivity of 10 - 29 e·cm.

Pretz, Jörg

2013-03-01

329

Measurements of field decay and snapback effect on Tevatron dipole and quadrupole magnets  

SciTech Connect

Since the beginning of 2002 an intensive measurement program has been performed at the Fermilab Magnet Test Facility (MTF) to understand dynamic effects in Tevatron magnets. Based on the results of this program a new correction algorithm was proposed to compensate for the decay of the sextupole field during the dwell at injection and for the subsequent field ''snapback'' during the first few seconds of the energy ramp. Beam studies showed that the new correction algorithm works better than the original one, and improves the Tevatron efficiency by at least 3%. The beam studies also indicated insufficient correction during the first 6s of the injection plateau where an unexpected discrepancy of 0.15 sextupole units of extra drift was observed. This paper reports on the most recent measurements of the Tevatron dipoles field at the beginning of the injection plateau. Results on the field decay and snapback in the Tevatron quadrupoles are also presented.

Velev, G.V.; Ambrosio, G.; Annala, G.; Bauer, P.; Carcagno, R.; DiMarco, J.; Glass, H.; Hanft, R.; Kephart, R.; Lamm, M.; Martens, M.; Schlabach, P.; Sylvester, C.; Tartaglia, M.; Tompkins, J.; /Fermilab

2005-05-01

330

Novel epoxy-free construction method for fabricating dipole magnets and test results  

SciTech Connect

Three model superconducting dipole magnets, lm length and having a bore diameter of 76mm, fabricated without epoxy resins or other adhesives, have been built and the first two have been tested in He I and He II. The conductor is the 23-strand Rutherford-type cable used in the Fermilab Doubler/Saver magnets, and is insulated with Mylar and Kapton. The two-layer winding is highly compessed by a system of structural support rings and tapered collets. Little training was required. Quench currents greater than 95% of short sample were obtained in He I with rise-times of 15 to 20 seconds to a central field of 4.6 T; 6.0 T in Helium II.

Taylor, C.; Althaus, R.; Caspi, S.; Gilbert, W.S.; Hassenzahl, W.; Meuser, R.; Rechen, J.; Warren, R.

1981-01-01

331

Vortex-antivortex dynamics in superconductor-antiparallel magnetic dipoles bilayers  

NASA Astrophysics Data System (ADS)

Artificial superconductor (S)/ferromagnet (F) hybrid structures composed by a S film and textured F layer have attracted great interest in the last fifteen years. In the limit of high values of magnetic moments, the ferromagnetic layer filled with magnetic particles (dipoles, nanodiscs, microrings, bars, etc.) can induce spontaneous creation and stabilization of vortex-antivortex (v-av) pairs in the S layer. These v-av molecules interact strongly with external applied currents inducing their annihilation or movement. Despite numerous studies about this subject, only a few of them emphasize the microscopic nature of this phenomena. In this work, the intricate dynamics of v-av molecules birth-death events and how this process influences macroscopic quantities are investigated.

Lima, Cléssio L. S.

2014-08-01

332

Electric-Field Control of Magnetism Intrinsic magnetoelectric coupling describes the microscopic interaction between magnetic and  

E-print Network

Electric-Field Control of Magnetism Intrinsic magnetoelectric coupling describes the microscopic interaction between magnetic and electric polarization in a single-phase material. The control of the magnetic of the two interactions. Moderate biaxial compression precipitates local magnetic competition

Maroncelli, Mark

333

Control of magnetic and electric responses with electric and magnetic fields in magnetoelectric heterostructures  

NASA Astrophysics Data System (ADS)

This paper reports on the tuning of both magnetic and electric responses with electric and magnetic fields for metglas-Pb (Zr,Ti)O3 based magnetoelectric (ME) heterostructures that can be promising for communication and sensor applications. The hysteresis loop results indicate a change in the in-plane magnetization due to application of voltages that leads to a tuning of the ferromagnetic resonance frequency by up to about 210 MHz with electric field. Furthermore, these structures show a high ME voltage coefficient that results in the detection of a 2 nT ac magnetic field and a low noise floor.

Das, J.; Li, M.; Kalarickal, S. S.; Altmannshofer, S.; Buchanan, K. S.; Li, J. F.; Viehland, D.

2010-05-01

334

Comment on "Prospects for a new search for the electron electric-dipole moment in solid gadolinium-iron-garnet ceramics"  

E-print Network

In a recent paper [A. O. Sushkov, S. Eckel and S. K. Lamoreaux, Phys. Rev. A 79, 022118 (2009), arXiv:0810.2756 ] the authors measured the EDM-induced magnetization M that is given by Eq. (1) in their paper. Such an expression for M is a consequence of the generally accepted opinion that both dipole moments, a MDM m and an EDM d, are proportional to the spin S. Recently [T. Ivezic, Phys. Scr. 81, 025001 (2010)] the Uhlenbeck-Goudsmit hypothesis is generalized in a Lorentz covariant manner using the four-dimensional (4D) geometric quantities. From the viewpoint of such formulation there is no EDM-induced magnetization M; in the 4D spacetime the EDM d^{a} is not proportional to S^{a}. It is argued that the induced M can come from the direct interaction between the applied electric field E^{a} and a MDM m^{a}.

Tomislav Ivezic

2010-05-17

335

Comment on "Prospects for a new search for the electron electric-dipole moment in solid gadolinium-iron-garnet ceramics"  

E-print Network

In a recent paper [A. O. Sushkov, S. Eckel and S. K. Lamoreaux, Phys. Rev. A 79, 022118 (2009), arXiv:0810.2756 ] the authors measured the EDM-induced magnetization M that is given by Eq. (1) in their paper. Such an expression for M is a consequence of the generally accepted opinion that both dipole moments, a MDM m and an EDM d, are proportional to the spin S. Recently [T. Ivezic, Phys. Scr. 81, 025001 (2010)] the Uhlenbeck-Goudsmit hypothesis is generalized in a Lorentz covariant manner using the four-dimensional (4D) geometric quantities. From the viewpoint of such formulation there is no EDM-induced magnetization M; in the 4D spacetime the EDM d^{a} is not proportional to S^{a}. It is argued that the induced M can come from the direct interaction between the applied electric field E^{a} and a MDM m^{a}.

Ivezic, Tomislav

2010-01-01

336

Order of magnitude smaller limit on the electric dipole moment of the electron.  

PubMed

The Standard Model of particle physics is known to be incomplete. Extensions to the Standard Model, such as weak-scale supersymmetry, posit the existence of new particles and interactions that are asymmetric under time reversal (T) and nearly always predict a small yet potentially measurable electron electric dipole moment (EDM), d(e), in the range of 10(-27) to 10(-30) e·cm. The EDM is an asymmetric charge distribution along the electron spin (S(?)) that is also asymmetric under T. Using the polar molecule thorium monoxide, we measured d(e) = (-2.1 ± 3.7stat ± 2.5syst) × 10(-29) e·cm. This corresponds to an upper limit of |d(e)| < 8.7 × 10(-29) e·cm with 90% confidence, an order of magnitude improvement in sensitivity relative to the previous best limit. Our result constrains T-violating physics at the TeV energy scale. PMID:24356114

Baron, J; Campbell, W C; DeMille, D; Doyle, J M; Gabrielse, G; Gurevich, Y V; Hess, P W; Hutzler, N R; Kirilov, E; Kozyryev, I; O'Leary, B R; Panda, C D; Parsons, M F; Petrik, E S; Spaun, B; Vutha, A C; West, A D

2014-01-17

337

Optical Spectroscopy of Tungsten Carbide for Uncertainty Analysis in Electron Electric Dipole Moment Search  

E-print Network

We perform laser induced fluorescence(LIF) spectroscopy on a pulsed supersonic beam of tungsten carbide(WC) molecules, which has been proposed as a candidate molecular system for a permanent Electric Dipole Moment(EDM) search of the electron in its rovibrational ground state of the X3Delta1 state. In particular, [20.6]Omega=2, v'=4 <- X3Delta1,v"=0 transition at 485nm was used for the detection. The hyperfine structure and the Omega-doublet of the transition are measured, which are essential for estimating the size of the potential systematic uncertainties for electron EDM measurement. For further suppression of the systematic uncertainty, an alternative electron EDM measurement scheme utilizing the g factor crossing point of the Omega-doublet levels is discussed. On the other hand, flux and internal temperature of the molecular beam are characterized, which sets the limit on the statistical uncertainty of the electron EDM experiment. With the given results, the prospect of electron EDM experiment with the...

Lee, J; Skripnikov, L V; Petrov, A N; Titov, A V; Mosyagin, N S; Leanhardt, A E

2012-01-01

338

Optical spectroscopy of tungsten carbide for uncertainty analysis in electron electric-dipole-moment search  

NASA Astrophysics Data System (ADS)

We perform laser-induced fluorescence spectroscopy on a pulsed supersonic beam of tungsten carbide (WC) molecules, which has been proposed as a candidate molecular system for a permanent electric dipole moment (EDM) search of the electron in its rovibrational ground state of the X3?1 state. In particular, [20.6]?=2,v'=4?X3?1,v''=0 transition at 485 nm was used for the detection. The hyperfine structure and the ? doublet of the transition is measured, which are essential for estimating the size of the potential systematic uncertainties for electron EDM measurement. For further suppression of the systematic uncertainty, an alternative electron EDM measurement scheme utilizing the g factor crossing point of the ?-doublet levels is discussed. On the other hand, flux and internal temperature of the molecular beam are characterized, which sets the limit on the statistical uncertainty of the electron EDM experiment. With the given results, the prospect of electron EDM experiment with the X3?1 state of WC molecule is discussed.

Lee, J.; Chen, J.; Skripnikov, L. V.; Petrov, A. N.; Titov, A. V.; Mosyagin, N. S.; Leanhardt, A. E.

2013-02-01

339

Search for a permanent electric-dipole moment using atomic indium  

SciTech Connect

We propose indium (In) as a possible candidate for observing the permanent electric dipole moment (EDM) arising from violations of parity (P) and time-reversal (T) symmetries. This atom has been laser cooled and therefore the measurement of its EDM has the potential of improving on the current best EDM limit for a paramagnetic atom, which comes from thallium. We report the results of our calculations of the EDM enhancement factor due to the electron EDM and the ratio of the atomic EDM to the electron-nucleus scalar-pseudoscalar (S-PS) interaction coupling constant in In within the framework of the relativistic coupled cluster theory. It might be possible to get new limits for the electron EDM and the S-PS CP-violating coupling constant by combining the results of our calculations with the measured value of the EDM of In when it is available. These limits could have important implications for the standard model (SM) of particle physics.

Sahoo, B. K. [Theoretical Physics Division, Physical Research Laboratory, Ahmedabad-380009 (India); Pandey, R. [Theoretical Astrophysics Group, Indian Astrophysics, Bangalore-560034 (India); School of Interdisciplinary and Transdisciplinary Studies, Indira Gandhi National Open University, New Delhi-110068 (India); Das, B. P. [Theoretical Astrophysics Group, Indian Astrophysics, Bangalore-560034 (India)

2011-09-15

340

Discrete dipole approximation simulations of absorption spectra and local electric field distributions of superparamagnetic magnetite nanoparticles  

NASA Astrophysics Data System (ADS)

The absorption spectra and local electric fields of nanosized superparamagnetic magnetites of four different shapes including a sphere, cube, cylinder and disk have been calculated using the discrete dipole approximation. The absorption efficiency and its peak position for the magnetite are dependent upon the morphology, geometry, particle orientation and ambient refractive index n. The calculation results indicate that the absorption efficiency increases with an increase in particle size, and the absorption peaks are red-shifted as the refractive index increases. The influence of size on the peak position is weak for nanospheres and nanocubes. In addition, for nanocylinders and nanodisks, increase of the aspect ratio results in a blue shift for the transverse mode (TM) and a red shift for the longitudinal mode (LM). From the TM to the LM, the peaks are blue-shifted for nanodisks, while being red-shifted for nanocylinders. Furthermore, the data curves of |E|/|E0|max and |E|/|E0|min maintain a nearly opposite trend to each other as the photon energy increases. It is notable that |E|/|E0|max shows a similar behavior to the real part of the dielectric function of magnetite bulk material. This feature can be attributed to the dielectric properties of this material.

Wang, Benyang; Qu, Shiliang

2013-04-01

341

Torsional electric dipole moment functions calculated for HOOH and ClOOCl.  

PubMed

The periodic torsional, electric dipole moment (EDM) functions ?(?) = ?m = 0pmcos?(m + 1?2)?, of the atmospherically significant molecules HOOH and ClOOCl, have been derived from calculations at the CCSD(T) (coupled-cluster singles and doubles model, plus a noniterative triples correction) level of electronic-structure theory with augmented, correlation-consistent basis sets extrapolated to the approximate complete basis set limit. The ?(?) of HOOH, defined by {pm} = {3.0979, -0.0301, -0.0058} D, is used to calculate squared transition EDMs that compare well with those previously derived using the experimental torsional line intensities. The ?(?) of ClOOCl, defined by ?(?) = {1.1935, 0.1163, 0.1341, -0.0040, -0.0099} D, requires a longer Fourier expansion because, in the range of dihedral angles from the cis (? = 0) to the trans (? = ?) transition structures, three inflection points are found for ClOOCl, but only one for HOOH. The permanent EDM calculated for HOOH, 1.754 D, is in close agreement with the value deduced from experiment. Compared to HOOH, the permanent EDM vector calculated for ClOOCl is directed analogously, but has a significantly smaller magnitude, 0.700 D. PMID:23485292

McGrath, Mark P

2013-03-01

342

The search for permanent electric dipole moments, in particular for the one of the neutron  

ScienceCinema

Nonzero permanent electric dipole moments (EDM) of fundamental systems like particles, nuclei, atoms or molecules violate parity and time reversal invariance. Invoking the CPT theorem, time reversal violation implies CP violation. Although CP-violation is implemented in the standard electro-weak theory, EDM generated this way remain undetectably small. However, this CP-violation also appears to fail explaining the observed baryon asymmetry of our universe. Extensions of the standard theory usually include new CP violating phases which often lead to the prediciton of larger EDM. EDM searches in different systems are complementary and various efforts worldwide are underway, but no finite value could be established yet. An improved search for the EDM of the neutron requires, among other things, much better statistics. At PSI, we are presently commissioning a new high intensity source of ultracold neutrons. At the same time, with an international collaboration, we are setting up for a new measurement of the neutron EDM which is starting this year.

None

2011-10-06

343

Studies on the electric dipole moment function and line parameters for high overtone bands of NO  

NASA Astrophysics Data System (ADS)

An accurate electric dipole moment function (EDMF) has been obtained by fitting the best available data including the pure rotational band 0-0 for individual ro-vibrational transitions for nitric oxide. Line intensities calculated using the fitted EDMF agree better with the measurements than the current HITRAN database. Moreover, the accurate ab initio potential energy curve (PEC) and EDMF were found using the multi-reference averaged quadratic coupled-cluster (AQCC) approach with the basis set aug-cc-pV6Z (aV6Z). The good agreement of the vibrational transition moments, computed using the Rydberg-Klein-Rees (RKR) potential and the fitted EDMFs, with experiments shows the present fitted EDMF could be more accurate than other fitted ones at the valid range. Our ab initio vibrational transition moments agree better with experimental data than the ones calculated using the previous theoretical PEC and EDMF, especially at the high overtones. We expect that the present study will be helpful for the transitions including high ? and high overtone bands of NO.

Chen, Huajun; Cheng, Xin Lu; Liu, Hao; Wu, Jie

2014-07-01

344

Experimental Determination of the Electric Dipole Moment Function of the X Pi-2 Hydroxyl Radical  

NASA Technical Reports Server (NTRS)

Laboratory infrared emission spectra of X 2piOH obtained with the Solar McMath FTS and the U. Paris (Orsay) FTS are used in an inversion procedure to experimentally determine the electric dipole moment function (EDMF) of the hydroxyl radical. The spectra produced at Kitt Peak show vibrational levels up to v = 10 and rotational lines in the range, -25.5 less than or equal to m less than or equal to 12.5. The following vibrational quantum number ranges were observed: for DELTA v = -1, v prime = 1 - 9, for DELTA v = -2, v prime = 2 - 10, and for DELTA v = - 3, v prime = 6 - 10. The spectra produced at Orsay show DELTA v = -1, with v prime = 1 - 4 and -22.5 less than or equal to m less than or equal to 9.5 as well as DELTA v = 0, with v prime= 1 - 3, and 9.5 less than or equal to m less than or equal to 25.5. The OH rovibrational wavefunctions used in the inversion procedure were calculated using a procedure which reproduces observed rotational constants with a high level of accuracy. Comparisons of our EDMF are made with previous experimental and theoretical work.

Chackerian, C., Jr.; Goorvitch, D.; Abrams, M. C.; Davis, S. P.; Benidar, A.; Farrenq, R.; Guelachvili, G.; Strawa, Anthony W. (Technical Monitor)

1995-01-01

345

Order of Magnitude Smaller Limit on the Electric Dipole Moment of the Electron  

E-print Network

The Standard Model (SM) of particle physics is known to be incomplete. It fails to explain dark matter, and why matter survived annihilation with antimatter following the Big Bang. Proposed extensions to the SM, such as weak-scale Supersymmetry (SUSY), may explain these phenomena by positing the existence of new particles and new interactions that are not symmetric under the time-reversal (T) transformation. These same theories nearly always predict a small, yet potentially measurable, asymmetric charge distribution directed along the spin ($\\vec{S}$) of the electron, an electric dipole moment (EDM, $\\vec{d_e}=d_e \\vec{S}/(\\hbar/2)$), which is also asymmetric under T. The predicted value of $d_e$ in these SM extensions is typically in the range of $10^{-27}$-$10^{-30}$ $e$ cm, orders of magnitude larger than is predicted by the SM. Here, we report a new search for the electron EDM using the polar molecule thorium monoxide (ThO). Our result, $d_e = (-2.1 \\pm 3.7_\\mathrm{stat} \\pm 2.5_\\mathrm{syst})\\times 10^{-...

Baron, Jacob; DeMille, David; Doyle, John M; Gabrielse, Gerald; Gurevich, Yulia V; Hess, Paul W; Hutzler, Nicholas R; Kirilov, Emil; Kozyryev, Ivan; O'Leary, Brendon R; Panda, Cristian D; Petrik, Elizabeth S; Spaun, Ben; Vutha, Amar C; West, Adam D

2014-01-01

346

Isotope shift of the electric-dipole transition in Os{sup -}  

SciTech Connect

The isotope shift of the bound-bound electric dipole transition at 1162.75 nm in the osmium anion was measured by high-precision collinear laser spectroscopy. The transition was observed in all naturally occurring isotopes, including {sup 184}Os{sup -} with a natural abundance of 0.02%. We combined the data with our prior measurements of the hyperfine structure in {sup 187}Os{sup -} and {sup 189}Os{sup -} and used them to determine experimental values for the isotope shift coefficients. The normal mass shift, specific mass shift, and field shift coefficients were found to be M{sub NMS}=141.4 GHz u, M{sub SMS}=2.4(12.6) THz u, and F=16.2(9.9) GHz fm{sup -2}, respectively. Theoretical values for the M{sub SMS} and F parameters were calculated based on a series of relativistic configuration interaction computations and a Fermi-like charge distribution and found to be in good agreement with the experimental values.

Kellerbauer, A.; Canali, C.; Fischer, A.; Warring, U.; Fritzsche, S. [Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, D-69117 Heidelberg (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstr. 1, D-64291 Darmstadt and FIAS Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, D-60438 Frankfurt/Main (Germany)

2011-12-15

347

Large electron electric dipole moment in minimal flavor violation framework with Majorana neutrinos  

E-print Network

The latest data from the ACME Collaboration have put a stringent constraint on the electric dipole moment d_e of the electron. Nevertheless, the standard model (SM) prediction for d_e is many orders of magnitude below the new result, making this observable a powerful probe for physics beyond the SM. We carry out a model-independent study of d_e in the SM with right handed neutrinos and its extension with the neutrino seesaw mechanism under the framework of minimal flavor violation. We find that d_e crucially depends on whether neutrinos are Dirac or Majorana particles. In the Majorana case, d_e can reach its experimental bound, and it constrains the scale of minimal flavor violation to be above a few hundred GeV or more. We also explore extra CP-violating sources in the Yukawa couplings of the right-handed neutrinos. Such new sources can have important effects on d_e.

Xiao-Gang He; Chao-Jung Lee; Siao-Fong Li; Jusak Tandean

2014-06-04

348

Ab initio study of the RbSr electronic structure: Potential energy curves, transition dipole moments, and permanent electric dipole moments.  

PubMed

Excited states and the ground state of the diatomic molecule RbSr were calculated by post Hartree-Fock molecular orbital theory up to 22 000 cm(-1). We applied a multireference configuration interaction calculation based on multiconfigurational self-consistent field wave functions. Both methods made use of effective core potentials and core polarization potentials. Potential energy curves, transition dipole moments, and permanent electric dipole moments were determined for RbSr and could be compared with other recent calculations. We found a good agreement with experimental spectra, which have been obtained recently by helium nanodroplet isolation spectroscopy. For the lowest two asymptotes (Rb (5s (2)S) + Sr (5s4d (3)P°) and Rb (5p (2)P°) + Sr (5s(2) (1)S)), which exhibit a significant spin-orbit coupling, we included relativistic effects by two approaches, one applying the Breit-Pauli Hamiltonian to the multireference configuration interaction wave functions, the other combining a spin-orbit Hamiltonian and multireference configuration interaction potential energy curves. Using the results for the relativistic potential energy curves that correspond to the Rb (5s (2)S) + Sr (5s4d (3)P°) asymptote, we have simulated dispersed fluorescence spectra as they were recently measured in our lab. The comparison with experimental data allows to benchmark both methods and demonstrate that spin-orbit coupling has to be included for the lowest states of RbSr. PMID:25527937

Pototschnig, Johann V; Krois, Günter; Lackner, Florian; Ernst, Wolfgang E

2014-12-21

349

Ab initio study of the RbSr electronic structure: Potential energy curves, transition dipole moments, and permanent electric dipole moments  

NASA Astrophysics Data System (ADS)

Excited states and the ground state of the diatomic molecule RbSr were calculated by post Hartree-Fock molecular orbital theory up to 22 000 cm-1. We applied a multireference configuration interaction calculation based on multiconfigurational self-consistent field wave functions. Both methods made use of effective core potentials and core polarization potentials. Potential energy curves, transition dipole moments, and permanent electric dipole moments were determined for RbSr and could be compared with other recent calculations. We found a good agreement with experimental spectra, which have been obtained recently by helium nanodroplet isolation spectroscopy. For the lowest two asymptotes (Rb (5s 2S) + Sr (5s4d 3P°) and Rb (5p 2P°) + Sr (5s2 1S)), which exhibit a significant spin-orbit coupling, we included relativistic effects by two approaches, one applying the Breit-Pauli Hamiltonian to the multireference configuration interaction wave functions, the other combining a spin-orbit Hamiltonian and multireference configuration interaction potential energy curves. Using the results for the relativistic potential energy curves that correspond to the Rb (5s 2S) + Sr (5s4d 3P°) asymptote, we have simulated dispersed fluorescence spectra as they were recently measured in our lab. The comparison with experimental data allows to benchmark both methods and demonstrate that spin-orbit coupling has to be included for the lowest states of RbSr.

Pototschnig, Johann V.; Krois, Günter; Lackner, Florian; Ernst, Wolfgang E.

2014-12-01

350

Inverse localization of electric dipole current sources in finite element models of the human head  

Microsoft Academic Search

The paper describes finite element related procedures for inverse localization of multiple sources in realistically shaped head models. Dipole sources are modeled by placing proper monopole sources on neighboring nodes. Lead field operators are established for dipole sources. Two different strategies for the solution of inverse problems, namely combinatorial optimization techniques and regularization methods are discussed and applied to visually

Helmut Buchner; Gunter Knoll; Manfred Fuchs; Adrian Rienäcker; Rainer Beckmann; Michael Wagner; Jiri Silny; Jörg Pesch

1997-01-01

351

Molecular Expressions: Electricity and Magnetism - Batteries  

NSDL National Science Digital Library

This page offers detailed background information on 15 different types of batteries. The author discusses the historical background of each battery, augmented with cross-sectional images and full explanations of how the batteries function. The item is part of a larger collection on Electricity and Magnetism sponsored by Florida State University.

Davidson, Michael

2007-06-12

352

Molecular Expressions: Electricity and Magnetism - Transformer  

NSDL National Science Digital Library

This java simulation illustrates the operation of a transformer. The user can change the input voltage and the number of primary and secondary windings. The simulation shows the input and output signal for the transformer. This resource is part of a larger collection on electricity and magnetism by the same authors.

Davidson, Michael

2007-10-23

353

Engineering the Input Impedance of Electric Planar Metamaterials Analogue of Dipole Array  

NASA Astrophysics Data System (ADS)

Since the demand of metamaterial (MM) based devices for practical applications is increased, the method with input impedance of dipole aims to produce fast results with reasonable accuracy for its design proposed. In this work, the unit of MM is equivalent to a dipole and then MM could be treated as a dipole array. An analysis is performed based on classical microwave dipole and numerical simulation by using the finite-difference time-domain for different MM configurations in the form of dipoles array. Additionally, a quality factor (Q-factor) based analysis is shown to yield simulation results which are in good agreement with the experiment. In essence, this shows that we could use antenna theory and numerical method to analyze MM thus opening the doors for a more efficient parameter optimization method.

Zhu, Yan-Wu; Qiu, Yang; Liu, Qi; Domenic, Belgiovane

2014-11-01

354

Alternate manufacturing processes and materials for the SSC dipole magnet coil end parts  

SciTech Connect

Modern magnet designs such as the SSC dipole utilize smaller bore diameter and wider superconducting cable. Challenging winding techniques place greater emphasis on the role of the coil end parts. Their complex configuration is derived from their function of confining the conductors to a consistent given shape and location. Present end parts, made of G-10 composite, are manufactured utilizing complex and expensive 5-axis machining techniques. Several alternate manufacturing processes and materials described in this paper will result in a substantial cost reduction for mass producing the end parts. The alternate processes are divided into two major groups. The composite group consists of Resin Transfer Molding (RAM), Compound Transfer Mold (CAM), Injection Molded Composite (IMP) and Compression Molded Composite (CC). The base metal coated group consists of Chemical Vapor Deposition (CAD) dip coating and hard coatings/anodizing. The paper will provide an overview of the various processes and compare test performance and cost to that of the process currently used.

Lipski, A.; Bossert, R.; Brandt, J.; Hoffman, J.; Kobliska, G.; Zweibohmer, J. (Fermi National Accelerator Lab., Batavia, IL (United States)); Higinbotham, W.; Shields, R.; Sims, R. (Superconducting Super Collider Lab., Dallas, TX (United States))

1992-04-01

355

Correlation of superconductor strand, cable and dipole critical currents in ISABELLE magnets  

SciTech Connect

A calibration between vendor critical current data for 0.0268'' diameter superconductor strand supplied to Fermilab, and the BNL 10/sup -12/ OMEGA cm critical current specification is presented. Vendor critical current data for over 400 Fermilab type billets are shown, both as supplied by the vendor and converted to BNL units. Predictions of cable critical current are made using the sum of the critical currents of the 23 strands, where all strands from the same half billet are assigned the same critical current. The measured cable critical current shows excellent correlation to the predicted value and is approximately 14 +- 2% below it. ISABELLE full length dipoles reach the conductor critical current limit, essentially without training. Magnet performance is predictable from the measured critical current of a short sample of cable to within 2%.

Tannenbaum, M.J.; Garber, M.; Sampson, W.B.

1982-01-01

356

Correlation of superconductor strand, cable, and dipole critical currents in CBA magnets  

SciTech Connect

A calibration between vendor critical current data for 0.0268'' diameter superconductor strand supplied to Fermilab, and the BNL 10/sup -12/..cap omega..cm critical current specification is presented. Vendor critical current data for over 400 Fermilab type billets are shown, both as supplied by the vendor and converted to BNL units. Predictions of cable critical current are made using the sum of the critical currents of the 23 strands, where all strands from the same half billet are assigned the same critical current. The measured critical current shows excellent correlation to the predicted value and is approximately 14 +- 2 percent below it. Colliding Beam Accelerator (CBA) full length dipoles reach the conductor critical current limit, essentially without training. Magnet performance is predictable from the measured critical current of a short sample of cable to within 2%.

Tannenbaum, M.J.; Garber, M.; Sampson, W.B.

1982-01-01

357

Magnetic-Dipole Transitions in Highly Charged Ions as a Basis of Ultraprecise Optical Clocks  

NASA Astrophysics Data System (ADS)

We evaluate the feasibility of using magnetic-dipole (M 1 ) transitions in highly charged ions as a basis of an optical atomic clockwork of exceptional accuracy. We consider a range of possibilities, including M 1 transitions between clock levels of the same fine-structure and hyperfine-structure manifolds. In highly charged ions these transitions lie in the optical part of the spectra and can be probed with lasers. The most direct advantage of our proposal comes from the low degeneracy of clock levels and the simplicity of atomic structure in combination with negligible quadrupolar shift. We demonstrate that such clocks can have projected fractional accuracies below the 1 0-20- 1 0-21 level for all common systematic effects, such as blackbody radiation, Zeeman, ac-Stark, and quadrupolar shifts.

Yudin, V. I.; Taichenachev, A. V.; Derevianko, A.

2014-12-01

358

Strict limit on in-plane ordered magnetic dipole moment in URu2Si2  

NASA Astrophysics Data System (ADS)

Neutron diffraction is used to examine the polarization of weak static antiferromagnetism in high quality single crystalline URu2Si2. As previously documented, elastic Bragg-like diffraction develops for temperature T magnetic dipole moment, which is associated with multipolar orders proposed for URu2Si2.

Ross, K. A.; Harriger, L.; Yamani, Z.; Buyers, W. J. L.; Garrett, J. D.; Menovsky, A. A.; Mydosh, J. A.; Broholm, C. L.

2014-04-01

359

Magnetic-dipole transitions in highly charged ions as a basis of ultraprecise optical clocks.  

PubMed

We evaluate the feasibility of using magnetic-dipole (M1) transitions in highly charged ions as a basis of an optical atomic clockwork of exceptional accuracy. We consider a range of possibilities, including M1 transitions between clock levels of the same fine-structure and hyperfine-structure manifolds. In highly charged ions these transitions lie in the optical part of the spectra and can be probed with lasers. The most direct advantage of our proposal comes from the low degeneracy of clock levels and the simplicity of atomic structure in combination with negligible quadrupolar shift. We demonstrate that such clocks can have projected fractional accuracies below the 10^{-20}-10^{-21} level for all common systematic effects, such as blackbody radiation, Zeeman, ac-Stark, and quadrupolar shifts. PMID:25526127

Yudin, V I; Taichenachev, A V; Derevianko, A

2014-12-01

360

Topology of surfaces for molecular Stark energy, alignment, and orientation generated by combined permanent and induced electric dipole interactions  

SciTech Connect

We show that combined permanent and induced electric dipole interactions of linear polar and polarizable molecules with collinear electric fields lead to a sui generis topology of the corresponding Stark energy surfaces and of other observables – such as alignment and orientation cosines – in the plane spanned by the permanent and induced dipole interaction parameters. We find that the loci of the intersections of the surfaces can be traced analytically and that the eigenstates as well as the number of their intersections can be characterized by a single integer index. The value of the index, distinctive for a particular ratio of the interaction parameters, brings out a close kinship with the eigenproperties obtained previously for a class of Stark states via the apparatus of supersymmetric quantum mechanics.

Schmidt, Burkhard, E-mail: burkhard.schmidt@fu-berlin.de [Institute for Mathematics, Freie Universität Berlin, Arnimallee 6, D-14195 Berlin (Germany)] [Institute for Mathematics, Freie Universität Berlin, Arnimallee 6, D-14195 Berlin (Germany); Friedrich, Bretislav, E-mail: brich@fhi-berlin.mpg.de [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin (Germany)] [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin (Germany)

2014-02-14

361

Multivariable current control for electrically and magnetically coupled superconducting magnets  

SciTech Connect

Superconducting magnet systems under construction and projected for the future contain magnets that are magnetically coupled and electrically connected with shared power supplies. A change in one power supply voltage affects all of the magnet currents. A current controller for these systems must be designed as a multivariable system. The paper describes a method, based on decoupling control, for the rational design of these systems. Dynamic decoupling is achieved by cross-feedback of the measured currents. A network of gains at the input decouples the system statically and eliminates the steady-state error. Errors are then due to component variations. The method has been applied to the magnet system of the MFTF-B, at the Lawrence Livermore National Laboratory.

Owen, E.W.; Shimer, D.W.

1985-02-08

362

Current trends in searches for new physics using measurements of parity violation and electric dipole moments in atoms and molecules  

E-print Network

We review current status of the study of parity and time invariance phenomena in atoms, nuclei and molecules. We focus on three most promising areas of research: (i) parity non-conservation in a chain of isotopes, (ii) search for nuclear anapole moments, and (iii) search for permanent electric dipole moments (EDM) of atoms and molecules which are caused by either, electron EDM or nuclear $T,P$-odd moments such as nuclear EDM and nuclear Schiff moment.

V. A. Dzuba; V. V. Flambaum

2010-09-25

363

Suppression of Secondary Electron Emission using Triangular Grooved Surface in the ILC Dipole and Wiggler Magnets  

SciTech Connect

The development of an electron cloud in the vacuum chambers of high intensity positron and proton storage rings may limit machine performance. The suppression of electrons in a magnet is a challenge for the positron damping ring of the International Linear Collider (ILC) as well as the Large Hadron Collider. Simulation show that grooved surfaces can significantly reduce the electron yield in a magnet. Some of the secondary electrons emitted from the grooved surface return to the surface within a few gyrations, resulting in a low effective secondary electron yield (SEY) of below 1.0 A triangular surface is an effective, technologically attractive mitigation with a low SEY and a weak dependence on the scale of the corrugations and the external magnetic field. A chamber with triangular grooved surface is proposed for the dipole and wiggler sections of the ILC and will be tested in KEKB in 2007. The strategy of electron cloud control in ILC and the optimization of the grooved chamber such as the SEY, impedance as well as the manufacturing of the chamber, are also discussed.

Wang, L.; Bane, K.; Chen, C.; Himel, T.; Munro, M.; Pivi, M.; Raubenheimer, T.; Stupakov, G.; /SLAC

2007-07-06

364

N=2 supersymmetry and dipole moments  

SciTech Connect

We derive sum rules for the magnetic and electric dipole moments of all particle states of an N=2 supermultiplet. For short representations, we find agreement with previously determined N=1 sum rules, while there is added freedom for long representations (expressed as certain scalar expectation values). With mild assumptions we find the simple result that the supersymmetry generated spin adds to the magnetic (electric) dipole moment with a strength corresponding to g=2 (g{sub e}=0). This result is equally valid for N=1, this time without any further assumptions. {copyright} {ital 1998} {ital The American Physical Society}

Giannakis, I.; Liu, J.T. [Physics Department, The Rockefeller University, 1230 York Avenue, New York, New York 10021-6399 (United States)] [Physics Department, The Rockefeller University, 1230 York Avenue, New York, New York 10021-6399 (United States)

1998-07-01

365

Magnetic response enhancement via electrically induced magnetic moments  

E-print Network

The realization of negative refraction in atomic gases requires a strong magnetic response of the atoms. Current proposals for such systems achieve an enhancement of the magnetic response by a suitable laser field configuration, but still rely on high gas densities. Thus further progress is desirable, and this requires an understanding of the precise mechanism for the enhancement. Therefore, here we study the magnetic and electric response to a probe field interacting with three-level atoms in ladder configuration. In our first model, the three transitions are driven by a control field and the electric and magnetic component of the probe field, giving rise to a closed interaction loop. In a reference model, the coherent driving is replaced by an incoherent pump field. A time-dependent analysis of the closed-loop system enables us to identify the different contributions to the medium response. A comparison with the reference system then allows one to identify the physical mechanism that leads to the enhancement. It is found that the enhancement occurs at so-called multiphoton resonance by a scattering of the coupling field and the electric probe field mode into the magnetic probe field mode. Based on these results, conditions for the enhancement are discussed.

B. Jungnitsch; J. Evers

2008-04-22

366

Local CP-violation and electric charge separation by magnetic fields from lattice QCD  

E-print Network

We study local CP-violation on the lattice by measuring the local correlation between the topological charge density and the electric dipole moment of quarks, induced by a constant external magnetic field. This correlator is found to increase linearly with the external field, with the coefficient of proportionality depending only weakly on temperature. Results are obtained on lattices with various spacings, and are extrapolated to the continuum limit after the renormalization of the observables is carried out. This renormalization utilizes the gradient flow for the quark and gluon fields. Our findings suggest that the strength of local CP-violation in QCD with physical quark masses is about an order of magnitude smaller than a model prediction based on nearly massless quarks in domains of constant gluon backgrounds with topological charge. We also show numerical evidence that the observed local CP-violation correlates with spatially extended electric dipole structures in the QCD vacuum.

G. S. Bali; F. Bruckmann; G. Endrodi; Z. Fodor; S. D. Katz; A. Schafer

2014-03-31

367

Dipole and quadrupole synthesis of electric potential fields. M.S. Thesis  

NASA Technical Reports Server (NTRS)

A general technique for expanding an unknown potential field in terms of a linear summation of weighted dipole or quadrupole fields is described. Computational methods were developed for the iterative addition of dipole fields. Various solution potentials were compared inside the boundary with a more precise calculation of the potential to derive optimal schemes for locating the singularities of the dipole fields. Then, the problem of determining solutions to Laplace's equation on an unbounded domain as constrained by pertinent electron trajectory data was considered.

Tilley, D. G.

1979-01-01

368

Design of a 10-T superconducting dipole magnet using niobium-tin conductor  

SciTech Connect

In order to minimize the size and cost of conventional facilities - land, tunneling, shielding, cryogenic and vacuum system - the dipole magnets for the next generation of particle accelerators must produce as strong a magnetic field as possible. Ten tesla seems to be a reasonable goal, and can be attained by using either niobium-tin conductor at 4.2 K or niobium-titanium at 1.8 K. The beam diameter in a multi-TeV accelerator, can in principle, be quite small, say 20 mm, depending on the design of the injection and extraction systems, and on beam-cooling technology. Magnet cost is strongly dependent on bore diameter, so there is a strong incentive to minimize that. We believe that a 40-mm bore diameter - about 60-mm winding inside diameter is feasible and is a reasonable goal for initial research and development. For such a high field and small bore, there is an incentive to achieve a high overall current density in order to minimize the amount of superconductor. Our design is based on an overall current density of 400 A/sq mm. LBL has undertaken the development of a magnet using niobium-tin conductor intended to meet the above specifications. The conductor is a Rutherford-type cable consisting of twelve strands of 1.71-mm-dia wire. Dimensions of the uninsulated cable are 11.0 x 3.0 mm. The configuration chosen consists of flat race-track layers - four per pole - with the ends bent up and down to clear the bore. Two coils are wound from a single piece of cable with a cross-over at the inside: the familiar double pancake arrangement.

Taylor, C.; Meuser, R.; Caspi, S.; Gilbert, W.; Hassenzahl, W.; Peters, C.; Schafer, R.; Wolgast, R.

1982-11-01

369

Magnetic flowmeter for electrically conductive liquid  

DOEpatents

A magnetic flowmeter includes first and second tube sections each having ls of non-magnetic material. The first tube is suitably connected to a process for passing a flow of an electrically conductive fluid to be measured. The second tube is established as a reference containing a still medium and is maintained at the same temperature as the first tube. A rotatable magnet assembly is disposed between the two tubes with at least two magnets attached to radially extending arms from a central shaft. Each magnet includes an air gap suitably sized to pass astraddle the diameter along a portion of the length of each of the two tubes. The magnets are provided in matched pairs spaced 180.degree. apart such that signals will be simultaneously generated in signal leads attached to each of the two tubes. By comparing the signals from the two tubes and varying the rotating speed of the magnet assembly until the signals are equal, or attain a maximum, the flow velocity of the fluid within the first tube can be determined. Through temperature monitoring and appropriate heaters, the two tubes are maintained at the same temperature.

Skladzien, Stanley B. (Elmhurst, IL); Raue, Donald J. (Naperville, IL)

1982-01-01

370

Electrical performance of a string of magnets representing a half-cell of the LHC machine  

SciTech Connect

Tests have been carried out on a string prototype superconducting magnets, consisting of one double-quadrupole and two double-dipoles forming the major part of a half-cell of the LHC machine. The magnets are protected individually by ``cold diodes`` and quench heaters. The electrical aspects of these tests are described here. The performance during quench of the protection diodes and the associated interconnections was studied. Tests determined the magnet quench performance in training and at different ramp-rates, and investigated the inter-magnet propagation of quenches. Current lead and inter-magnet contact resistances were controlled and the performance of the power converter and the dump switches assessed.

Rodriguez-Mateos, F.; Coull, L.; Dahlerup-Petersen, K.; Hagedorn, D.; Krainz, G.; Rijllart, A. [European Organization for Nuclear Research, Geneva (Switzerland); McInturff, A. [Lawrence Berkeley Lab., CA (United States)

1995-06-21

371

Improving Students' Understanding of Electricity and Magnetism  

ERIC Educational Resources Information Center

Electricity and magnetism are important topics in physics. Research shows that students have many common difficulties in understanding concepts related to electricity and magnetism. However, research to improve students' understanding of electricity and magnetism is limited compared to introductory mechanics. This thesis explores issues…

Li, Jing

2012-01-01

372

Molecular Expressions: Electricity & Magnetism: Interactive Java Tutorials  

NSDL National Science Digital Library

The Optical Microscopy Division of the National High Magnetic Field Laboratory (NHMFL) provides these state of the art Electricity & Magnetism Tutorials (For more from NHMFL, see the August 4, 1999 Scout Report for Science & Engineering). The wide variety of interactive tutorials (Java) includes topics like Atomic Orbitals, Cathode Rays, Faraday's Electromagnetic Induction Experiment, Lenz's Law, AC and DC Generator Action, and more. The Atomic Orbitals tutorial, for example, lets users select any combination of the first four atomic orbitals (s, p, d, and f) and view their orientations in relation to x, y, and z axes. These tutorials provide simple and useful tools for visualizing concepts.

373

Magnetic Dipole Inflation with Cascaded ARC and Applications to Mini-Magnetospheric Plasma Propulsion  

NASA Technical Reports Server (NTRS)

Mini-Magnetospheric Plasma Propulsion (M2P2) seeks to create a plasma-inflated magnetic bubble capable of intercepting significant thrust from the solar wind for the purposes of high speed, high efficiency spacecraft propulsion. Previous laboratory experiments into the M2P2 concept have primarily used helicon plasma sources to inflate the dipole magnetic field. The work presented here uses an alternative plasma source, the cascaded arc, in a geometry similar to that used in previous helicon experiments. Time resolved measurements of the equatorial plasma density have been conducted and the results are discussed. The equatorial plasma density transitions from an initially asymmetric configuration early in the shot to a quasisymmetric configuration during plasma production, and then returns to an asymmetric configuration when the source is shut off. The exact reasons for these changes in configuration are unknown, but convection of the loaded flux tube is suspected. The diffusion time was found to be an order of magnitude longer than the Bohm diffusion time for the period of time after the plasma source was shut off. The data collected indicate the plasma has an electron temperature of approximately 11 eV, an order of magnitude hotter than plasmas generated by cascaded arcs operating under different conditions. In addition, indirect evidence suggests that the plasma has a beta of order unity in the source region.

Giersch, L.; Winglee, R.; Slough, J.; Ziemba, T.; Euripides, P.

2003-01-01

374

Excitation of the centrifugally driven interchange instability in a plasma confined by a magnetic dipole  

SciTech Connect

The centrifugally driven electrostatic interchange instability is excited for the first time in a laboratory magnetoplasma. The plasma is confined by a dipole magnetic field, and the instability is excited when an equatorial mesh is biased to induce a radial current that creates rapid axisymmetric plasma rotation. The observed instabilities appear quasicoherent in the lab frame of reference; they have global radial mode structures and low azimuthal mode numbers, and they are modified by the presence of energetic, magnetically confined electrons. The mode structure is measured using a multiprobe correlation technique as well as a novel 96-point polar imaging diagnostic which measures particle flux along field lines that map to the pole. Interchange instabilities caused by hot electron pressure are simultaneously observed at the hot electron drift frequency. Adjusting the hot electron fraction {alpha} modifies the stability as well as the structures of the centrifugally driven modes. In the presence of larger fractions of energetic electrons, m=1 is observed to be the dominant mode. For faster rotating plasmas containing fewer energetic electrons, m=2 dominates. Results from a self-consistent nonlinear simulation reproduce the measured mode structures in both regimes. The low azimuthal mode numbers seen in the experiment and simulation can also be interpreted with a local, linear dispersion relation of the electrostatic interchange instability. Drift resonant hot electrons give the instability a real frequency, inducing stabilizing ion polarization currents that preferentially suppress high-m modes.

Levitt, B.; Maslovsky, D.; Mauel, M.E.; Waksman, J. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

2005-05-15

375

Metamaterial-enhanced coupling between magnetic dipoles for efficient wireless power transfer  

NASA Astrophysics Data System (ADS)

Nonradiative coupling between conductive coils is a candidate mechanism for wireless energy transfer applications. In this paper we propose a power relay system based on a near-field metamaterial superlens and present a thorough theoretical analysis of this system. We use time-harmonic circuit formalism to describe all interactions between two coils attached to external circuits and a slab of anisotropic medium with homogeneous permittivity and permeability. The fields of the coils are found in the point-dipole approximation using Sommerfeld integrals which are reduced to standard special functions in the long-wavelength limit. We show that, even with a realistic magnetic loss tangent of order 0.1, the power transfer efficiency with the slab can be an order of magnitude greater than free-space efficiency when the load resistance exceeds a certain threshold value. We also find that the volume occupied by the metamaterial between the coils can be greatly compressed by employing magnetic permeability with a large anisotropy ratio.

Urzhumov, Yaroslav; Smith, David R.

2011-05-01

376

Electric control of magnetization relaxation in thin film magnetic insulators.  

SciTech Connect

Control of magnetization relaxation in magnetic insulators via interfacial spin scattering is demonstrated. The experiments use nanometer-thick yttrium iron garnet (YIG)/Pt layered structures, with the Pt layer biased by an electric voltage. The bias voltage produces a spin current across the Pt thickness. As this current scatters off the YIG surface, it exerts a torque on the YIG surface spins. This torque can reduce or enhance the damping and thereby decrease or increase the ferromagnetic resonance linewidth of the YIG film, depending on the field/current configuration.

Wang, Z.; Sun, Y.; Song, Y-Y.; Wu, M.; Schultheiss, H.; Pearson, J. E.; Hoffmann, A. (Materials Science Division); (Colorado State Univ.)

2011-10-01

377

Magnetic monopole-like response in metamaterials  

NASA Astrophysics Data System (ADS)

In this paper, we explored magnetic monopole-like responses in metamaterials. We designed a sub-wavelength metamolecule that is composed of two dielectric-spaced split-ring resonators. In response to incident waves, the induced magnetic field in the metamolecule resembles that of a two-dimensional magnetic monopole. The magnetic monopole-like response is resulted from electric resonance of the metamolecule, so an electric dipole is always attached. By combining two mirror-symmetric metamolecules with inward and outward radial magnetic fields, magnetic dipole-like responses can be produced just as an electric dipole is formed by separating two opposite-signed electric charges.

Wang, Jiafu; Qu, Shaobo; Xu, Zhuo; Zhang, Anxue; Ma, Hua; Zhang, Jieqiu; Chen, Hongya; Feng, Mingde

2014-11-01

378

The Levitated Dipole Experiment (LDX) investigates plasmas confined in the closed field line dipole magnetic geometry where the plasma stability  

E-print Network

) Magnetic equilibrium flux loops, Bp coils, Hall effect sensors, levitation system trackers Fast electrons/O Feedback Loop 150 kW Power Supply Operator Interface LDX Data System PLC Low Speed I/O Coil and Bus the observed particle pinch. In future experiments, an optimal levitation control system will be implemented

379

IRON SATURATION CONTROL IN RHIC DIPOLE MAGNETS* P.A.Thompson,R.C.Gupta,S.A.Kahn,H.Hahn.G.H.Morgan,PJ.Wanderer,E.Willen.  

E-print Network

IRON SATURATION CONTROL IN RHIC DIPOLE MAGNETS* P.A.Thompson,R.C.Gupta,S.A.Kahn of the yoke iron. Changes have been made to the yoke to reduce these perturbations, in particular, decapole The proposed RHIC will include 360 "standard" superconducting dipoles(bore=BOmm, design field=3.45 T). The iron

Gupta, Ramesh

380

A New Limit on the Permanent Electric Dipole Moment (EDM) of ^199Hg  

NASA Astrophysics Data System (ADS)

A finite permanent electric dipole moment (EDM) of a particle or atom would violate time reversal symmetry (T), and would also imply violation of the combined charge conjugation and parity symmetry (CP) through the CPT theorem. EDMs are suppressed in the standard model of particle physics (SM), lying many orders of magnitude below current experimental sensitivity. It is generally accepted, however, that extra sources of CP violation are needed to account for baryogenesis and many theories beyond the SM, such as supersymmetry, naturally predict EDMs within experimental reach. To date, EDM searches have yielded null results. The most precise and significant limits have been set on the EDM of the neutronootnotetextC.A. Baker, et al., Phys. Rev. Lett. 97, 131801 (2006)., the electronootnotetextB.C. Regan, et al., Phys. Rev. Lett. 88, 071805 (2002)., and the ^ 199Hg atomootnotetextM.V. Romalis, et al., Phys. Rev. Lett. 86, 2505 (2001)., leading to tight constraints on sypersymmetric extensions of the SM. I will describe the results from a new experimental search for the EDM of ^199 Hg. We find d(^199Hg) = (0.49 ±1.29stat±0.76syst) x10-29 e cm, and interpret this as a new upper bound, d(^199Hg) < 3.1x10-29 e cm (95% C.L.)ootnotetextW.C. Griffith, et al., ArXiv:0901.2328v1.. This result improves our previous ^ 199Hg limit by a factor of 7 and offers a yet more exacting probe of possible new sources of CP violation. The experiment utilizes a stack of four spin-polarized Hg vapor cells in a common B-field. The middle two cells have oppositely directed E-fields, resulting in EDM-sensitive Larmor shifts of opposite sign; the outer two cells, enclosed by the high voltage (HV) electrodes and thus placed at E = 0, are free of EDM effects and instead allow cancelation of B- field gradient noise and checks for spurious HV-correlated B- field shifts. The dataset consists of 166 runs, with each run lasting roughly 24 hours and comprising several hundred E- field reversals. Measurements were performed for nine different vapor cells, four electrodes, two cell-containing vessels, and multiple vapor cell and electrode orientations. An unknown, HV- correlated, EDM-mimicking offset was added to the fitted values of the middle cell precession frequencies. This fixed blind offset masked the measured EDM and was revealed only after the data collection, data cuts, and error analysis were complete. In addition to experimental results, I will briefly outline the resulting new upper bounds on fundamental CP violating parameters.

Loftus, Thomas H.

2009-05-01

381

Lunar magnetic permeability, magnetic fields, and electrical conductivity temperature  

NASA Technical Reports Server (NTRS)

In the time period 1969-1972 a total of five magnetometers were deployed on the lunar surface during four Apollo missions. Data from these instruments, along with simultaneous measurements from other experiments on the moon and in lunar orbit, were used to study properties of the lunar interior and the lunar environment. The principal scientific results from analyses of the magnetic field data are discussed. The results are presented in the following main categories: (1) lunar electrical conductivity, temperature, and structure; (2) lunar magnetic permeability, iron abundance, and core size limits; (3) the local remnant magnetic fields, their interaction with the solar wind, and a thermoelectric generator model for their origin. Relevant publications and presented papers are listed.

Parkin, C. W.

1978-01-01

382

The bremsstrahlung spectrum for the electric dipole which nonradially falls into a black hole  

E-print Network

The electromagnetic bremsstrahlung spectrum for the dipole which falling by a spiral orbit into the Schwarzschild black hole was found. The characteristic features in this electromagnetic spectrum can be used for determine of the black hole mass by the new way. This new way (if implemented) provides higher accuracy in determining of the black hole mass. Also these features in the spectrum can be used for determine of the certain characteristics in the black hole magnetosphere or in the accretion disk characteristics around the black hole. It is also shown that the asymptotic behavior of this spectrum (at high frequencies) is practically independent from the impact parameter of the falling dipole.

Shatskiy, Alexander; Malinovsky, Alexandr

2015-01-01

383

Cavity-QED based on collective magnetic dipole coupling: spin ensembles as hybrid two-level systems  

E-print Network

We analyze the magnetic dipole coupling of an ensemble of spins to a superconducting microwave stripline structure, incorporating a Josephson junction based transmon qubit. We show that this system is described by an embedded Jaynes-Cummings model: in the strong coupling regime, collective spin-wave excitations of the ensemble of electrons pick up the nonlinearity of the cavity mode, such that the two lowest eigenstates of the coupled spin-wave + microwave-cavity + Josephson-junction system define a hybrid two-level system. The proposal described here enables the use of spin ensembles as qubits which can be coherently manipulated and coupled using the same nonlinear-cavity. Possibility of strong-coupling cavity-QED with magnetic-dipole transitions opens up the possibility of extending previously proposed quantum information processing protocols to spins in silicon or graphene, without the need for single-electron confinement.

Atac Imamoglu

2008-09-17

384

Solder-Filling of a Cicc Cable for the Efda Dipole Magnet  

NASA Astrophysics Data System (ADS)

Several prototype Cable-In-Conduit-Conductors (CICC) for the superconducting EDIPO (Efda DIPOle) revealed a degradation of their critical current (Ic) increasing with each loading cycle. The strong Lorentz-forces during operation in combination with the limited support of the single strands against these forces are thought to be the cause of the permanent degradation of the brittle Nb3Sn superconductor from which the multi-stranded CICC are made. In summer 2006 EFDA started to explore the possibility to remedy the Ic degradation by solder-filling the conductor in order to mechanically stabilize the twisted-strand cable inside the conduit. This solution was not considered as the main one, but as an emergency solution to be applied to the completed magnet, should every other option fail. The solder-filling approach was previously applied with success in some cases. Some issues, however, needed to be clarified before this solution could be proposed for the EDIPO project. The most important among them are the choice of solder material, details of the solder filling process, and the thermo-mechanical implications of a solder-filled, high-field, high-current cable. This work, being reported here, made use not only of simulation but also of experiments, such as the mechanical testing of solder filled cables at cryogenic temperatures.

Bauer, P.; Bruzzone, P.; Cau, F.; Weiss, K.; Portone, A.; Salpietro, E.; Vogel, M.; Vostner, A.

2008-03-01

385

Contribution of the source velocity to the scattering of electromagnetic fields caused by airborne magnetic dipoles  

NASA Astrophysics Data System (ADS)

The velocity of controlled airborne sources of electromagnetic geophysical surveys plays an additional role in the scattering of the fields by the earth. Therefore, it is necessary to investigate its contribution in the space and time variation of secondary electromagnetic fields. The model of a vertical magnetic dipole moving at a constant speed along a horizontal line in the air and above a homogeneous conductive half-space constitutes a first approach to stress the kinematic aspect and determine the difference between the fields due to an airborne and a static source. The magnetic moment of the source is equal to 104 A m2, its height is 120 m, and the horizontal and vertical separations between it and the receiver are, respectively, equal to 100 and 50 m: these values of the model are typical of towed-bird airborne TDEM surveys. We employed four values for the common velocities of source and receiver (0, 60, 80, and 100 m s-1), four values of the conductivity of the half-space (0.5, 0.1, 0.05, and 0.01 S m-1), and two causal source currents (box with periods of 80 and 10 ms and periodic with frequency values of 12.5 and 100 Hz). The results demonstrate that the relative velocity between source and medium yields a measurable variation compared to the static condition. Therefore, it must be taken into consideration by compensating the discrepancy in measured data employing the respective theoretical result. The results also show that it is necessary to adjust the concepts of time and frequency domain for electromagnetic measurements with traveling sources.

Emanoel Starteri Sampaio, Edson

2014-08-01

386

Electric dipole polarizability of alkaline-earth-metal atoms from perturbed relativistic coupled-cluster theory with triples  

NASA Astrophysics Data System (ADS)

The perturbed relativistic coupled-cluster (PRCC) theory is applied to calculate the electric dipole polarizabilities of alkaline-earth-metal atoms. The Dirac-Coulomb-Breit atomic Hamiltonian is used and we include the triple excitations in the relativistic coupled-cluster theory. The theoretical issues related to the triple excitation cluster operators are described in detail and we also provide details on the computational implementation. The PRCC theory results are in good agreement with the experimental and previous theoretical results. We, then, highlight the importance of considering the Breit interaction for alkaline-earth-metal atoms.

Chattopadhyay, S.; Mani, B. K.; Angom, D.

2014-02-01

387

On the electric-dipole contribution to the valence-band offsets in semiconductor-oxide heterostructures  

Microsoft Academic Search

The continua of interface-induced gap states (IFIGS) determine the band-structure lineup at semiconductor interfaces. Hence, both barrier heights of Schottky contacts and valence-band offsets in semiconductor heterostructures are composed of a zero-charge-transfer and an electric-dipole term. The analysis of experimental barrier heights and valence-band offsets yields IFIGS branch-point energies of 3.51+\\/-0.07 eV for SiO2 and 2.98+\\/-0.26 eV, 2.27+\\/-0.14, and 2.87+\\/-0.14

Winfried Mönch

2007-01-01

388

A high dynamic range data acquisition system for a solid-state electron electric dipole moment experiment  

SciTech Connect

We have built a high precision (24-bit) data acquisition (DAQ) system capable of simultaneously sampling eight input channels for the measurement of the electric dipole moment of the electron. The DAQ system consists of two main components: a master board for DAQ control and eight individual analog-to-digital converter (ADC) boards for signal processing. This custom DAQ system provides galvanic isolation of the ADC boards from each other and the master board using fiber optic communication to reduce the possibility of ground loop pickup and attain ultimate low levels of channel cross-talk. In this paper, we describe the implementation of the DAQ system and scrutinize its performance.

Kim, Young Jin; Kunkler, Brandon; Liu, Chen-Yu; Visser, Gerard [CEEM, Physics Department, Indiana University, Bloomington, Indiana 47408 (United States)

2012-01-15

389

Evaluating an electricity and magnetism assessment tool: Brief electricity and magnetism assessment  

NASA Astrophysics Data System (ADS)

The Brief Electricity and Magnetism Assessment (BEMA), developed by Chabay and Sherwood, was designed to assess student understanding of basic electricity and magnetism concepts covered in college-level calculus-based introductory physics courses. To evaluate the reliability and discriminatory power of this assessment tool, we performed statistical tests focusing both on item analyses (item difficulty index, item discrimination index, and item point biserial coefficient) and on the entire test (test reliability and Ferguson’s delta). The results indicate that BEMA is a reliable assessment tool.

Ding, Lin; Chabay, Ruth; Sherwood, Bruce; Beichner, Robert

2006-06-01

390

Evaluating an electricity and magnetism assessment tool: Brief electricity and magnetism assessment  

NSDL National Science Digital Library

The Brief Electricity and Magnetism Assessment (BEMA), developed by Chabay and Sherwood, was designed to assess student understanding of basic electricity and magnetism concepts covered in college-level calculus-based introductory physics courses. To evaluate the reliability and discriminatory power of this assessment tool, we performed statistical tests focusing both on item analyses (item difficulty index, item discrimination index, and item point biserial coefficient) and on the entire test (test reliability and Fergusonâs delta). The results indicate that BEMA is a reliable assessment tool.

Ding, Lin; Chabay, Ruth; Sherwood, Bruce; Beichner, Robert J.

2006-04-21

391

Ceramic electrical insulation for electrical coils, transformers, and magnets  

DOEpatents

A high temperature electrical insulation is described, which is suitable for electrical windings for any number of applications. The inventive insulation comprises a cured preceramic polymer resin, which is preferably a polysiloxane resin. A method for insulating electrical windings, which are intended for use in high temperature environments, such as superconductors and the like, advantageously comprises the steps of, first, applying a preceramic polymer layer to a conductor core, to function as an insulation layer, and second, curing the preceramic polymer layer. The conductor core preferably comprises a metallic wire, which may be wound into a coil. In the preferred method, the applying step comprises a step of wrapping the conductor core with a sleeve or tape of glass or ceramic fabric which has been impregnated by a preceramic polymer resin. The inventive insulation system allows conducting coils and magnets to be fabricated using existing processing equipment, and maximizes the mechanical and thermal performance at both elevated and cryogenic temperatures. It also permits co-processing of the wire and the insulation to increase production efficiencies and reduce overall costs, while still remarkably enhancing performance.

Rice, John A. (Longmont, CO); Hazelton, Craig S. (Lafayette, CO); Fabian, Paul E. (Broomfield, CO)

2002-01-01

392

Superconducting dipole magnet requirements for the Fermilab Phase 3 upgrade, SSC high energy booster, and Fermilab independent collider  

SciTech Connect

In July 1988 a small working group was formed to develop a conceptual design for a high field superconducting dipole magnet suitable for use in the Phase III upgrade at Fermilab. The Phase III upgrade calls for replacement of the existing Tevatron with higher field magnets to boost the energy of the fixed target program to 1.5 TeV and to add a 1.8 TeV collider program. As the work of this group evolved it became clear that the resulting design might be applicable to more than just the proposed upgrade. In particular, it seemed plausible that the work might be applicable to the high energy booster (HEB) for the SSC. At the Breckenridge Workshop in August 1989 interest in a third project began to surface, namely the revamping of an earlier proposal for a dedicated collider at Fermilab. We refer to this proposal as the FNAL Independent Collider. The requirements for the dipole magnets for this independent collider appear to be remarkably similar to those proposed for the Phase III upgrade and the SSC HEB. The purpose of this report is to compare the conceptual design of the dipoles developed for the Phase III proposal with the requirements of those for the SSC HEB, the FNAL Independent Collider, and a hybrid design which could serve the needs of both. The Phase III design will be used as the reference point for parameter scaling. 4 figs., 3 tabs.

Nicol, T.H.; Kerby, J.S.

1989-09-01

393

Contribution of the electric quadrupole resonance in optical metamaterials  

NASA Astrophysics Data System (ADS)

Optical metamaterials can exhibit negative index of refraction when both the effective permittivity and permeability are negative. The negative permeability is usually considered to be associated with a magnetic dipole resonance and the contribution from electric quadrupoles is neglected. Here, we show by simulation that the electric quadrupole contribution is actually comparable to that from magnetic dipoles. We propose an experimental scheme to determine the relative contributions from the electric dipole, magnetic dipole, and electric quadrupole of a metallic nanostructure. This can be important in the design of metamaterials.

Cho, David J.; Wang, Feng; Zhang, Xiang; Shen, Y. Ron

2008-09-01

394

Estimates of the relative magnitudes of the isotropic and anisotropic magnetic-dipole hyperfine interactions in alkali-metal-noble-gas systems  

Microsoft Academic Search

We present a detailed theoretical analysis of the noble-gas nuclear-spin relaxation due to the anisotropic magnetic-dipole hyperfine interaction between the noble-gas nucleus and alkali-metal valence electron vis à vis the already well-understood (spin-conserving) isotropic magnetic-dipole hyperfine interaction in alkali-metal-noble-gas systems. We find that, for all pairs in which the noble gas is not helium, the predicted spin-relaxation rate from the

D. K. Walter; W. Happer; T. G. Walker

1998-01-01

395

Physics 8.02: Electricity and Magnetism  

NSDL National Science Digital Library

This is the online version of a course on electricity and magnetism taught at the Massachusetts Institute of Technology (MIT). Topics covered include vector fields, electrostatics, magnetostatics, Faraday's Law, and light. The course can be navigated either by means of a Guided Tour, which provides a robust description of the physics associated with each section of the course, or via Course Notes, which provide a more in-depth exposition of the material. Both the Guided Tour and the Course Notes link to numerous visualizations/animations designed to help students understand the concepts being discussed. The animations can also be accessed independently, on web pages devoted to each course topic.

Liao, Sen-Ben; Dourmashkin, Peter; Belcher, Professor J.; Center For Eudcational Computer Initiatives, Mit

2003-12-18

396

Cross coupling between electric and magnetic orders in a multiferroic  

E-print Network

of multiferroics beyond inorganic materials. However, the coupling between two orders in multiferroic MOFs has electric and magnetic orders in a multiferroic MOF [(CH3)2NH2]Fe(HCOO)3 with a perovskite structure (magnetic field control of dielectric properties) and converse (electric field control of magnetization

Wang, Wei Hua

397

Calculation Method of Permanent Magnet Pickups for Electric Guitars  

E-print Network

1 Calculation Method of Permanent Magnet Pickups for Electric Guitars G. Lemarquand and V This paper first presents the structures of permanent magnet pickups for electric guitar and the considered device: string, magnet, coil. It then describes a method to calculate the induced electromotive force

Paris-Sud XI, Université de

398

PSU/SL Physics Animations Portal: Electricity and Magnetism  

NSDL National Science Digital Library

This web site contains a large collection of animations illustrating basic concepts of Electricity and Magnetism. It covers topics such as electric and magnetic fields, flux, Gauss's law, conduction and circuit, induction, and magnetic force. This is a part of a collection of similar videos covering many topics in physics and astronomy.

Gallis, Michael R.

2007-10-29

399

The Electric and Magnetic Personalities of Mr. Maxwell  

NSDL National Science Digital Library

Students are briefly introduced to Maxwell's equations and their significance to phenomena associated with electricity and magnetism. Basic concepts such as current, electricity and field lines are covered and reinforced. Through multiple topics and activities, students see how electricity and magnetism are interrelated.

STARS GK-12 Program,

400

Magnetic dipole discharges. II. Cathode and anode spot discharges and probe diagnostics  

SciTech Connect

The high current regime of a magnetron-type discharge has been investigated. The discharge uses a permanent magnet as a cold cathode which emits secondary electrons while the chamber wall or a grounded electrode serves as the anode. As the discharge voltage is increased, the magnet develops cathode spots, which are short duration arcs that provide copious electrons to increase the discharge current dramatically. Short (1 ?s), high current (200 A) and high voltage (750 V) discharge pulses are produced in a relaxation instability between the plasma and a charging capacitor. Spots are also observed on a negatively biased plane Langmuir probe. The probe current pulses are as large as those on the magnet, implying that the high discharge current does not depend on the cathode surface area but on the properties of the spots. The fast current pulses produce large inductive voltages, which can reverse the electrical polarity of the magnet and temporarily operate it as an anode. The discharge current may also oscillate at the frequency determined by the charging capacitor and the discharge circuit inductance. Each half cycle of high-current current pulses exhibits a fast (?10 ns) current rise when a spot is formed. It induces high frequency (10–100 MHz) transients and ringing oscillations in probes and current circuits. Most probes behave like unmatched antennas for the electromagnetic pulses of spot discharges. Examples are shown to distinguish the source of oscillations and some rf characteristics of Langmuir probes.

Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)] [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States); Ionita, C.; Schrittwieser, R. [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)] [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)

2013-08-15

401

Transient particle acceleration in strongly magnetized neutron stars. II - Effects due to a dipole field geometry  

NASA Technical Reports Server (NTRS)

Sheared Alfven waves generated by nonradial crustal disturbances above the polar cap of a strongly magnetized neutron star induce an electric field component parallel to B. An attempt is made to determine the manner in which the strong radial dependence of B affects the propagation of these sheared Alfven waves, and whether this MHD process is still an effective particle accelerator. It is found that although the general field equation is quite complicated, a simple wavelike solution can still be obtained under the conditions of interest for which the Alfven phase velocity decouples from the wave equation. The results may be applicable to gamma-ray burst sources.

Fatuzzo, Marco; Melia, Fulvio

1991-01-01

402

Adjusted oscillator strength matching for hybrid magnetic and electric excitations in Dy3Fe5O12 garnet  

NASA Astrophysics Data System (ADS)

Far-infrared spectra of magnetodielectric Dy3Fe5O12 garnet were studied using a combination of transmittance, reflectivity, and rotating analyzer ellipsometry. In addition to purely dielectric and magnetic modes, we observed several hybrid modes with a mixed magnetic and electric dipole activity. Using 4×4 matrix formalism for materials with ?(?)?1, we modeled the experimental optical spectra and determined the far-infrared dielectric and magnetic permeability functions. The matching condition ?(?h)Se=?(?h)Sm for the oscillator strengths Se(m) explains the observed vanishing of certain hybrid modes at ?h in reflectivity.

Rogers, P. D.; Choi, Y. J.; Standard, E. C.; Kang, T. D.; Ahn, K. H.; Dubroka, A.; Marsik, P.; Wang, Ch.; Bernhard, C.; Park, S.; Cheong, S.-W.; Kotelyanskii, M.; Sirenko, A. A.

2011-05-01

403

Assembly and Test of HD2, a 36 mm bore high field Nb3Sn Dipole Magnet  

SciTech Connect

We report on the fabrication, assembly, and test of the Nb{sub 3}Sn dipole magnet HD2. The magnet, aimed at demonstrating the application of Nb{sub 3}Sn superconductor in high field accelerator-type dipoles, features a 36 mm clear bore surrounded by block-type coils with tilted ends. The coil design is optimized to minimize geometric harmonics in the aperture and the magnetic peak field on the conductor in the coil ends. The target bore field of 15 T at 4.3 K is consistent with critical current measurements of extracted strands. The coils are horizontally pre-stressed during assembly using an external aluminum shell pre-tensioned with water-pressurized bladders. Axial pre-loading of the coil ends is accomplished through two end plates and four aluminum tension rods. The strain in coil, shell, and rods is monitored with strain gauges during assembly, cool-down and magnet excitation, and compared with 3D finite element computations. Magnet's training performance, quench locations, and ramp-rate dependence are then analyzed and discussed.

Ferracin, P.; Bingham, B.; Caspi, S.; Cheng, D. W,.; Dietderich, D. R.; Felice, H.; Godeke, A.; Hafalia, A. R.; Hannaford, C. R.; Joseph, J.; Lietzke, A. F.; Lizarazo, J.; Sabbi, G.; Trillaud, F.; Wang, X.

2008-08-17

404

Analysis of Electric Field Induced by ELF Magnetic Field Utilizing Generalized Equivalent Multipole-Moment Method  

NASA Astrophysics Data System (ADS)

This paper presents a generalized equivalent multipole-moment method for calculating three-dimensional Laplacian fields in multi-spherical system. The Greengard & Rokhlin's M2M, M2L, and L2L formulae enable the multipole-moment method to calculate the fields in general arrangement of multi-spheres, which involve exclusive and multi-layered spherical arrangement. We applied this method to electric field calculation in biological structures induced by ELF magnetic fields. The induced electric fields in a three eccentric and exclusive spheres system, which models human head with two eyeballs, are calculated under the application of homogeneous and magnetic-dipole fields. The validity of this method is successfully confirmed by comparing the calculated fields with those by the fast-multipole surface-charge-simulation method.

Hamada, Shoji; Yamamoto, Osamu; Kobayashi, Tetsuo

405

Supersymmetric electric-magnetic duality of hypergravity  

NASA Astrophysics Data System (ADS)

Hypergravity is the theory in which the graviton, of spin-2, has a supersymmetric partner of spin-5/2. There are "no-go" theorems that prevent interactions in these higher spin theories. However, it appears that one can circumvent them by bringing in an infinite tower of higher spin fields. With this possibility in mind, we study herein the electric-magnetic duality invariance of hypergravity. The analysis is carried out in detail for the free theory of the spin-(2,5/2) multiplet, and it is indicated how it may be extended to the infinite tower of higher spins. Interactions are not considered. The procedure is the same that was employed recently for the spin-(3/2,2) multiplet of supergravity. One introduces new potentials ("prepotentials") by solving the constraints of the Hamiltonian formulation. In terms of the prepotentials, the action is written in a form in which its electric-magnetic duality invariance is manifest. The prepotential action is local, but the spacetime invariance is not manifest. Just as for the spin-2 and spin-(3/2,2) cases, the gauge symmetries of the prepotential action take a form similar to those of the free conformal theory of the same multiplet. The automatic emergence of gauge conformal invariance, out of demand for manifest duality invariance, is yet more evidence of the subtle interplay between duality invariance and spacetime symmetry. We also compare and contrast the formulation with that of the analogous spin-(1,3/2) multiplet.

Bunster, Claudio; Henneaux, Marc; Hörtner, Sergio; Leonard, Amaury

2014-08-01

406

Electric Flux Tube in Magnetic Plasma  

E-print Network

In this paper we study a methodical problem related to the magnetic scenario recently suggested and initiated by the authors \\cite{Liao_ES_mono} to understand the strongly coupled quark-gluon plasma (sQGP): the electric flux tube in monopole plasma. A macroscopic approach, interpolating between Bose condensed (dual superconductor) and classical gas medium is developed first. Then we work out a microscopic approach based on detailed quantum mechanical calculation of the monopole scattering on electric flux tube, evaluating induced currents for all partial waves. As expected, the flux tube looses its stability when particles can penetrate it: we make this condition precise by calculating the critical value for the product of the flux tube size times the particle momentum, above which the flux tube dissolves. Lattice static potentials indicate that flux tubes seem to dissolve at $T>T_{dissolution} \\approx 1.3 T_c$. Using our criterion one gets an estimate of the magnetic density $n\\approx 4.4 \\sim 6.6 fm^{-3}$ at this temperature.

Jinfeng Liao; Edward Shuryak

2007-12-06

407

What Are Electric and Magnetic Fields? (EMF)  

MedlinePLUS

... 60 hertz (Hz). If something uses batteries, the electric current flows in one direction only, and it is ... practical situations, DC electric power does not induce electric currents in humans. AC electric power produces electric and ...

408

Electric-magnetic duality implies (global) conformal invariance  

E-print Network

We have examined quantum theories of electric magnetic duality invariant vector fields enjoying classical conformal invariance in 4-dimensional flat spacetime. We extend Dirac's argument about "the conditions for a quantum field theory to be relativistic" to "those for a quantum theory to be conformal". We realize that electric magnetic duality invariant vector theories together with classical conformal invariance defined in 4-$d$ flat spacetime are still conformally invariant theories when they are quantized in a way that electric magnetic duality is manifest.

Sung-Pil Moon; Sang-Jin Lee; Ji-Hye Lee; Jae-Hyuk Oh

2014-05-30

409

Coupling Magnetism to Electricity in Multiferroic Heterostructures  

SciTech Connect

Complex perovskite oxides exhibit a rich spectrum of functional responses, including magnetism, ferroelectricity, highly correlated electron behavior, superconductivity, etc. The basic materials physics of such materials provide the ideal playground for interdisciplinary scientific exploration. Over the past decade we have been exploring the science of such materials (for example, colossal magnetoresistance, ferroelectricity, etc) in thin-film form by creating epitaxial heterostructures and nanostructures. Among the large number of materials systems, there exists a small set of materials which exhibit multiple order parameters; these are known as multiferroics. Using our work in the field of ferroelectric and ferromagnetic oxides as the background, we are now exploring such materials as epitaxial thin films, as well as nanostructures. Specifically, we are studying the role of thin-film growth, heteroepitaxy, and processing on the basic properties as well as the magnitude of the coupling between the order parameters. In our work we are exploring the switchability of the antiferromagnetic order using this coupling. What is the importance of this work? Antiferromagnets are pervasive in the recording industry. They are used as exchange biasing layers in magnetic tunnel junctions, etc. However, to date there has been no antiferomagnet that is electrically tunable. We believe that the multiferroic BiFeO3 is one compound where this can be observed at room temperature. The next step is to explore the coupling of a ferromagnet to this antiferromagnet through the exchange biasing concept. Ultimately, this will give us the opportunity to switch the magnetic state in a ferromagnet (and therefore the spin polarization direction) by simply applying an electric field to the underlying antiferromagnetic ferroelectric. In this talk, I will describe our progress to date on this exciting possibility.

Ramesh, R. (U.S. DOE) [U.S. DOE

2012-02-15

410

Nuclear magnetic relaxation induced by exchange-mediated orientational randomization: Longitudinal relaxation dispersion for a dipole-coupled spin-1/2 pair  

NASA Astrophysics Data System (ADS)

In complex biological or colloidal samples, magnetic relaxation dispersion (MRD) experiments using the field-cycling technique can characterize molecular motions on time scales ranging from nanoseconds to microseconds, provided that a rigorous theory of nuclear spin relaxation is available. In gels, cross-linked proteins, and biological tissues, where an immobilized macromolecular component coexists with a mobile solvent phase, nuclear spins residing in solvent (or cosolvent) species relax predominantly via exchange-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings. The physical or chemical exchange processes that dominate the MRD typically occur on a time scale of microseconds or longer, where the conventional perturbation theory of spin relaxation breaks down. There is thus a need for a more general relaxation theory. Such a theory, based on the stochastic Liouville equation (SLE) for the EMOR mechanism, is available for a single quadrupolar spin I = 1. Here, we present the corresponding theory for a dipole-coupled spin-1/2 pair. To our knowledge, this is the first treatment of dipolar MRD outside the motional-narrowing regime. Based on an analytical solution of the spatial part of the SLE, we show how the integral longitudinal relaxation rate can be computed efficiently. Both like and unlike spins, with selective or non-selective excitation, are treated. For the experimentally important dilute regime, where only a small fraction of the spin pairs are immobilized, we obtain simple analytical expressions for the auto-relaxation and cross-relaxation rates which generalize the well-known Solomon equations. These generalized results will be useful in biophysical studies, e.g., of intermittent protein dynamics. In addition, they represent a first step towards a rigorous theory of water 1H relaxation in biological tissues, which is a prerequisite for unravelling the molecular basis of soft-tissue contrast in clinical magnetic resonance imaging.

Chang, Zhiwei; Halle, Bertil

2013-10-01

411

Density profiles of plasmas confined by the field of a Levitating Dipole Magnet  

E-print Network

A 4-channel microwave interferometer (center frequency: 60 GHz) has been constructed to measure the density profiles of plasmas confined within the Levitated Dipole Experiment (LDX). LDX is the first and only experiment ...

Boxer, Alexander C

2009-01-01

412

Unraveling the electronic structure of azolehemiporphyrazines: direct spectroscopic observation of magnetic dipole allowed nature of the lowest ?-?* transition of 20?-electron porphyrinoids.  

PubMed

Hemiporphyrazines are a large family of phthalocyanine analogues in which two isoindoline units are replaced by other rings. Here we report unambiguous identification of 20?-electron structure of triazolehemiporphyrazines (1, 2) and thiazolehemiporphyrazine (3) by means of X-ray analysis, various spectroscopic methods, and density functional theory (DFT) calculations. The hemiporphyrazines were compared in detail with dibenzotetraazaporphyrin (4), a structurally related 18?-electron molecule. X-ray analysis revealed that tetrakis(2,6-dimethylphenyloxy)triazolehemiporphyrazine (1b) adopted planar geometry in the solid state. A weak absorption band with a pronounced vibronic progression, observed for all the hemiporphyrazines, was attributed to the lowest ?-?* transition with the electric-dipole-forbidden nature. In the case of intrinsically chiral vanadyl triazolehemiporphyrazine (2), a large dissymmetry (g) factor was detected for the CD signal corresponding to the lowest ?-?* transition with the magnetic-dipole-allowed nature. Molecular orbital analysis and NICS calculations showed that the azolehemiporphyrazines have a 20?-electron system with a weak paratropic ring current. PMID:24866729

Muranaka, Atsuya; Ohira, Shino; Toriumi, Naoyuki; Hirayama, Machiko; Kyotani, Fumiko; Mori, Yukie; Hashizume, Daisuke; Uchiyama, Masanobu

2014-06-26

413

Thermal to electricity conversion using thermal magnetic properties  

DOEpatents

A system for the generation of Electricity from Thermal Energy using the thermal magnetic properties of a Ferromagnetic, Electrically Conductive Material (FECM) in one or more Magnetic Fields. A FECM is exposed to one or more Magnetic Fields. Thermal Energy is applied to a portion of the FECM heating the FECM above its Curie Point. The FECM, now partially paramagnetic, moves under the force of the one or more Magnetic Fields. The movement of the FECM induces an electrical current through the FECM, generating Electricity.

West, Phillip B [Idaho Falls, ID; Svoboda, John [Idaho Falls, ID

2010-04-27

414

Recalculation of radial matrix integrals for the electric dipole transitions in hydrogen  

SciTech Connect

Radial matrix integrals for the dipole approximation are calculated by employing a transformation of variables due to Schroedinger and an expansion theorem for the associated Laguerre polynomials. The resulting formulas involve a single sum in which the expansion parameter is already inverted. The formulas are suitable for machine calculations for transitions between neighboring states characterized by large values of the principal quantum numbers. It is pointed out that systems such as an electron-proton system interacting via the temperature-modified Coulomb potential can benefit from this technique. 17 refs.

Malik, G.P.; Malik, U.; Varma, V.S. (Jawaharlal Nehru University, New Delhi (India))

1991-04-01

415

Electric dipole moments of nitric acid-water complexes measured by cluster beam deflection  

E-print Network

Water clusters embedding a nitric acid molecule HNO3(H2O)_{n=1-10} are investigated via electrostatic deflection of a molecular beam. We observe large paraelectric susceptibilities that greatly exceed the electronic polarizability, revealing the contribution of permanent dipole moments. The moments derived from the data are also significantly higher than those of pure water clusters. An enhancement in the susceptibility for n=5,6 and a rise in cluster abundances setting in at n=6 suggest that dissociation of the solvated acid molecule into ions takes place in this size range.

Moro, Ramiro; Kresin, Vitaly V

2009-01-01

416

Introduction to power-frequency electric and magnetic fields.  

PubMed Central

This paper introduces the reader to electric and magnetic fields, particularly those fields produced by electric power systems and other sources using frequencies in the power-frequency range. Electric fields are produced by electric charges; a magnetic field also is produced if these charges are in motion. Electric fields exert forces on other charges; if in motion, these charges will experience magnetic forces. Power-frequency electric and magnetic fields induce electric currents in conducting bodies such as living organisms. The current density vector is used to describe the distribution of current within a body. The surface of the human body is an excellent shield for power-frequency electric fields, but power-frequency magnetic fields penetrate without significant attenuation; the electric fields induced inside the body by either exposure are comparable in magnitude. Electric fields induced inside a human by most environmental electric and magnetic fields appear to be small in magnitude compared to levels naturally occurring in living tissues. Detection of such fields thus would seem to require the existence of unknown biological mechanisms. Complete characterization of a power-frequency field requires measurement of the magnitudes and electrical phases of the fundamental and harmonic amplitudes of its three vector components. Most available instrumentation measures only a small subset, or some weighted average, of these quantities. Hand-held survey meters have been used widely to measure power-frequency electric and magnetic fields. Automated data-acquisition systems have come into use more recently to make electric- and magnetic-field recordings, covering periods of hours to days, in residences and other environments.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8206045

Kaune, W T

1993-01-01

417

Artificial light and quantum order in systems of screened dipoles Xiao-Gang Wen  

E-print Network

Artificial light and quantum order in systems of screened dipoles Xiao-Gang Wen Department) The origin of light is a unsolved mystery in nature. Recently, it was suggested that light may originate from magnetic/electric dipoles in 2D and 3D lattices. We show that our models contain an artificial light

Wen, Xiao-Gang

418

Reversible electric-field control of magnetization at oxide interfaces  

NASA Astrophysics Data System (ADS)

Electric-field control of magnetism has remained a major challenge which would greatly impact data storage technology. Although progress in this direction has been recently achieved, reversible magnetization switching by an electric field requires the assistance of a bias magnetic field. Here we take advantage of the novel electronic phenomena emerging at interfaces between correlated oxides and demonstrate reversible, voltage-driven magnetization switching without magnetic field. Sandwiching a non-superconducting cuprate between two manganese oxide layers, we find a novel form of magnetoelectric coupling arising from the orbital reconstruction at the interface between interfacial Mn spins and localized states in the CuO2 planes. This results in a ferromagnetic coupling between the manganite layers that can be controlled by a voltage. Consequently, magnetic tunnel junctions can be electrically toggled between two magnetization states, and the corresponding spin-dependent resistance states, in the absence of a magnetic field.

Cuellar, F. A.; Liu, Y. H.; Salafranca, J.; Nemes, N.; Iborra, E.; Sanchez-Santolino, G.; Varela, M.; Hernandez, M. Garcia; Freeland, J. W.; Zhernenkov, M.; Fitzsimmons, M. R.; Okamoto, S.; Pennycook, S. J.; Bibes, M.; Barthélémy, A.; Te Velthuis, S. G. E.; Sefrioui, Z.; Leon, C.; Santamaria, J.

2014-06-01

419

Reversible electric-field control of magnetization at oxide interfaces.  

PubMed

Electric-field control of magnetism has remained a major challenge which would greatly impact data storage technology. Although progress in this direction has been recently achieved, reversible magnetization switching by an electric field requires the assistance of a bias magnetic field. Here we take advantage of the novel electronic phenomena emerging at interfaces between correlated oxides and demonstrate reversible, voltage-driven magnetization switching without magnetic field. Sandwiching a non-superconducting cuprate between two manganese oxide layers, we find a novel form of magnetoelectric coupling arising from the orbital reconstruction at the interface between interfacial Mn spins and localized states in the CuO2 planes. This results in a ferromagnetic coupling between the manganite layers that can be controlled by a voltage. Consequently, magnetic tunnel junctions can be electrically toggled between two magnetization states, and the corresponding spin-dependent resistance states, in the absence of a magnetic field. PMID:24953219

Cuellar, F A; Liu, Y H; Salafranca, J; Nemes, N; Iborra, E; Sanchez-Santolino, G; Varela, M; Garcia Hernandez, M; Freeland, J W; Zhernenkov, M; Fitzsimmons, M R; Okamoto, S; Pennycook, S J; Bibes, M; Barthélémy, A; te Velthuis, S G E; Sefrioui, Z; Leon, C; Santamaria, J

2014-01-01

420

Improvement of magnetosphere structure calculations using eccentric dipole to account for the internal magnetic field  

NASA Astrophysics Data System (ADS)

In this paper we build upon the results previously produced by numerous attempts, including our own, to approximate the geomagnetic field with a an eccentric dipole instead of spherical harmonics expansions. Among other motivations to do so is that dipole-related effects are much more pronounced relative to higher-order harmonics at large distances from the Earth, and that the shift of the order of magnitude about 0.1 Earth radii is significant enough for many magnetospheric structures such as the current sheet. We present the results of multivariate simulated annealing, which includes translational and rotational repositioning of the dipole. We also include similar results produced for Mercury and Saturn, and we extend Earth-related data with Oersted and Cluster measurements in order to further improve our accuracy.

Parunakian, David

2014-05-01

421

Tuning Polymer Nanocomposite Morphology: Magnetic and AC Electric Field Manipulation of Epoxy - Montmorillonite (Clay) Suspensions  

NASA Astrophysics Data System (ADS)

The next revolutionary leap forward for polymer nano-'composites' necessitates the development of tools to transform the currently random or ill-defined nanoscale morphologies into compositionally and spatially engineered hierarchal structures, paralleling that underpinning conventional continuous fiber reinforced composites and enabling experimental verification of morphology-mechanical property correlations. Here in, utilization of AC electric fields of modest strength (1-10 V/micron) is demonstrated as a general approach to align organically modified layered silicates (OLS) parallel to the electric field - enhancing CTE, modulus and optical clarity in the reinforced direction. Interfacial polarization arising from electrophoric motion of the organic-modifier on the layer surface induces a dipole parallel to the plane of the layer, which couples to the external field. Comparably, application of a static magnetic field (0.5-2 T) induces alignment of the layers parallel or perpendicular to the field, depending on the chemical composition of the OLS. The impact of field magnitude, field frequency, dielectric permittivity and magnetic permeability of the system is discussed to elucidate the molecular characteristics of induced dipole formation and establish the limits of the process.

Vaia, Richard; Koerner, Hilmar; Jacobs, J. David; Busbee, John; Hampton, Edwin; Dean, Derrick

2004-03-01

422

Animations for Physics and Astronomy: Electricity and Magnetism Animations  

NSDL National Science Digital Library

This web site contains a large collection of animations illustrating basic concepts of electricity and magnetism. It covers topics such as electric fields, flux, gauss's law, conduction, magnetic force, etc. Animations can be viewed in a number of different formats, either embedded in a web page or through a downloaded media file.

Gallis, Michael

2010-04-06

423

Different annealing treatments for improvement of magnetic and electrical properties of soft magnetic composites  

Microsoft Academic Search

This paper investigates the effect of two steps, annealing and magnetic annealing, on the magnetic and electrical properties of iron powder particles with high purity used in soft magnetic composite materials. It was found that at low frequencies (<10kHz) the magnetic loss in the high-temperature magnetic annealed state is smaller than that in the low-temperature magnetic, magnetic annealed and without

H. Shokrollahi; K. Janghorban

2007-01-01

424

Measurement of a magnetic-dipole transition probability in Xe32+ using an electron-beam ion trap  

E-print Network

019344! and NIST for support. J.R. Roberts, C.M. Brown, and U. Feldman, Phys. Rev. A 53, 2220 ~1996!. @10# J. Sugar ~private communication!. @11# F.A. Parpia, I.P. Grant, and C.F. Fischer, GRASP2 ~private com- munication!. @12# E. Tra?bert, Nucl..., 1616 ~1994!. @15# J. Doerfert, E. Tra?bert, J. Granzow, A. Wolf, J. Kenntner, D. Habs, M. Grieser, T. Schu??ler, U. Schramm, and P. Forck, Nucl. Instrum. Methods B 98, 53 ~1995!. 55 MEASUREMENT OF A MAGNETIC-DIPOL of the signal upon switching...

Serpa, F. G.; Morgan, C. A.; Meyer, E. S.; Gillaspy, J. D.; Trabert, E.; Church, David A.; Takacs, E.

1997-01-01

425

Perturbative analysis of the electron electric dipole moment and CP violation in two-Higgs-doublet models  

NASA Astrophysics Data System (ADS)

I consider a general two-Higgs-doublet model with CP violation. I give a perturbative expansion for the mass eigenstates in terms of the small CP-violating phase. I use these analytical expressions to show that O(10-2) CP violation is allowed by the experimental bounds on the electron electric dipole moment in some regions of the parameter space. These regions also include parameters that are expected to give a strongly first-order electroweak phase transition required for electroweak baryogenesis. I also comment on how to incorporate the CP violation into the searches for a strongly first-order electroweak phase transition which could explain the matter/antimatter asymmetry in the Universe.

Ipek, Seyda

2014-04-01

426

CP Violation in D0-D0bar Mixing and Electric Dipole Moments in SUSY Alignment Models  

SciTech Connect

We report on a study of CP Violation in D{sup 0}-{bar D}{sup 0} mixing and Electric Dipole Moments in the framework of supersymmetric alignment models. Both classes of observables are strongly suppressed in the Standard Model and highly sensitive to new sources of flavor and CP violation that can be present in models of New Physics. Supersymmetric alignment models generically predict large non-standard effects in D{sup 0}-{bar D}{sup 0} mixing and we show that visible CP violation in D{sup 0}-{bar D}{sup 0} mixing implies lower bounds for the EDMs of hadronic systems, like the neutron EDM and the mercury EDM, in the reach of future experimental sensitivities. We also give updated constraints on the mass insertions of the Minimal Supersymmetric Standard Model using the current data on D{sup 0}-{bar D}{sup 0} mixing.

Altmannshofer, Wolfgang

2011-05-01

427

Constraining the density slope of nuclear symmetry energy at subsaturation densities using electric dipole polarizability in 208Pb  

NASA Astrophysics Data System (ADS)

Nuclear structure observables usually most effectively probe the properties of nuclear matter at subsaturation densities rather than at saturation density. We demonstrate that the electric dipole polarizibility ?D in 208Pb is sensitive to both the magnitude Esym(?c) and density slope L (?c) of the symmetry energy at the subsaturation cross density ?c=0.11 fm-3. Using the experimental data of ?D in 208Pb from RCNP (Research Center for Nuclear Physics, Osaka University) and the recent accurate constraint of Esym(?c) from the binding energy difference of heavy isotope pairs, we extract a value of L (?c)=47.3 ±7.8 MeV. The implication of the present constraint of L (?c) to the symmetry energy at saturation density, the neutron skin thickness of 208Pb and the core-crust transition density in neutron stars is discussed.

Zhang, Zhen; Chen, Lie-Wen

2014-12-01

428

Mean-field analysis of ground-state and low-lying electric dipole strength in C22  

NASA Astrophysics Data System (ADS)

Properties of neutron-rich C22 are studied using the mean-field approach with Skyrme energy density functionals. Its weak binding and large total reaction cross section, which are suggested by recent experiments, are simulated by modifying the central part of Skyrme potential. Calculating E1 strength distribution by using the random-phase approximation, we investigate developments of low-lying electric dipole (E1) strength and the contribution of core excitations of C20. As the neutron Fermi level approaches the zero-energy threshold (?F?-1 MeV), we find that the low-lying E1 strength exceeds the energy-weighted cluster sum rule, which indicates the importance of core excitations with the 1d5/2 orbit.

Inakura, T.; Horiuchi, W.; Suzuki, Y.; Nakatsukasa, T.

2014-06-01

429

Theoretical Determination of the Form of the Boundary of the Solar Corpuscular Stream Produced by Interaction with the Magnetic Dipole Field of the Earth  

Microsoft Academic Search

The interaction between a neutral stream of ionized solar corpuscles and a three-dimensional magnetic dipole representing the geomagnetic field is investigated. It is assumed that the stream is confined to the exterior and the magnetic field to the interior of a hollow, the boundary of which is defined by a thin current sheath. An approximate method of solution is applied,

John R. Spreiter; Benjamin R. Briggs

1962-01-01

430

Observation of Centrifugally Driven Interchange Instabilities in a Plasma Confined by a Magnetic Dipole  

E-print Network

moon [5,6]. Satellite measurements form a consistent estimate of the average mass outflow velocity [7 with an axisymmetric tungsten mesh placed at the equator of the dipole electromagnet and protruding about 1 cm. In rapidly rotating discharges having reduced populations of fast electrons, the dominant wave- length

Mauel, Michael E.

431

PLASMA CONFINEMENT IN A MAGNETIC DIPOLE* J. KESNER AND L. BROMBERG  

E-print Network

for advanced fuels. A new experimental facility is presently being built to test the stability and transport interchange stability is determined by the requirement that compressibility balance the energy of expansion chamber. Since the peak plasma pressure depends on the edge pressure, dipole energy and particle balance

432

Electric Magnetic Circuit Active Elements Based on Magnetorheological Elastomers  

Microsoft Academic Search

The circuit magnetic active element presented in the paper is based on electroconductive magnetorheological elastomer. This element and the experimental set-up for studies in magnetic field are presented in some detail. It is shown that the voltage U at the outlet of the electric circuit depends on the intensity H of the magnetic field and is considerably influenced by the

G. Catana; B. Vatzulik; O. E. Andrei; L. Chirigiu; I. Bica

2010-01-01

433

Relativistic many-body calculations of energy levels, hyperfine constants, electric-dipole matrix elements, and static polarizabilities for alkali-metal atoms  

E-print Network

Relativistic many-body calculations of energy levels, hyperfine constants, electric-dipole matrix elements, and static polarizabilities for alkali-metal atoms M. S. Safronova, W. R. Johnson, and A Removal energies and hyperfine constants of the lowest four ns, np1/2 , and np3/2 states in Na, K, Rb

Johnson, Walter R.

434

Motion of a Charged Parand Plasma Equilibrium in a Dipole Magnetic Field Can a Magnetic Field Trap a Charged Particle? Can a Magnetic Field Having Bad Curvature Trap a Plasma Stably?  

NASA Astrophysics Data System (ADS)

Since there is no magnetic monopole, the dipole magnetic field is the most elementary form of magnetic field. By studying carefully the motion of a single charged particle and the plasma equilibrium that results, one can obtain insight in the basic behavior of particle motion and equilibrium in a magnetic field. What will be the exact motion of a charged particle? What will be the guiding center motion? Are the equations of motion integrable? What happens if not? Is the plasma equilibrium in a magnetic field having bad curvature everywhere stable? This paper will cover these elementary questions using Hamiltonian dynamics.

Hasegawa, Akira

2005-01-01

435

Design of epoxy-free superconducting dipole magnets and performance in both Helium I and pressurized Helium II  

SciTech Connect

Three model superconducting dipole magnets 1m long, without iron, having a bore diameter of 76 mm have been built without epoxy resins or other adhesives and tested in He I and He II. The conductor is the 23-strand Rutherford-type cable used in the Fermilab Doubler Saver magnets, and is insulated with Mylar and Kapton. The two-layer winding is highly compressed by a system of structural support rings and tapered collets. Little training was required to reach quench currents greater than 95% of short sample in Helium I. The maximum quench current in He II is increased 20 to 30%, compared with He I operation at 4.4 K. Test results are given on cyclic losses, heater-induced quenches, and charge-rate effects.

Taylor, C.; Althaus, R.; Caspi, S.; Gilbert, W.; Hassenzahl, W.; Meuser, R.; Rechen, J.; Warren, R.

1981-03-01

436

Prediction of solar magnetic field at solar cycle 24/25 minimum based on current trends of dipole and quadrupole components  

NASA Astrophysics Data System (ADS)

During the recent Solar Cycles (SCs), solar activity parameters such as the total solar irradiance, interplanetary magnetic field and solar polar magnetic field get weakened. The length of solar cycle from SC 23 to SC 24 becomes much longer than previous solar cycles. The polarity of solar magnetic field is of not only dipole but also sum of multipoles such as the quadrupole and so on. In this study, we analyze the magnitude of harmonic function coefficients and the variation of dipole and multipole components provided by Wilcox Solar Observatory (WSO). As a result, the magnitude of total solar magnetic field shows a significant decrease since SC 23. The decrease rate of dipole is larger than that of multipole during the SC 23. It means that the dipole component gets weaker and the multipole one getse stronger in SC 23 compared with SCs 21 and 22. Thus, the multipole component is important factor in determining the solar activity. In general, the dipole component is weak at the solar maximum period and strong at the solar minimum period. The composition ratio of multipole component, particularly quadrupole increases at the solar minimum of SC 23/24. If the solar activity is low such as the solar cycle 23/24 minimum, the quadrupole component may show the relative increase. Therefore, we can predict that the solar activity will be further weaker at next solar minimum of SC 24/25 and the quadrupole component may show the remarkable increase.

Kim, B.; Oh, S.; Yi, Y.

2012-12-01

437

Instability of a spherical drop in the field of an electrical dipole  

NASA Astrophysics Data System (ADS)

Analytical calculations show that, as a field in which an initially spherical charged conducting incompressible drop is placed becomes more and more nonuniform, coupling between the drop's oscillation modes grows and the threshold of stability against the electrical field pressure declines. When an electrostatic parameter characterizing the electric field pressure exceeds a value that is critical for a certain mode to be unstable, the amplitude of this mode exponentially grows in an aperiodic manner and the amplitudes of modes coupled with this mode build up in an oscillatory manner, each mode having its own instability growth rate. In all cases, there exists a threshold value of the dimensionless electric parameter above which all oscillation modes are unstable.

Shiryaeva, S. O.; Grigor'ev, A. I.; Shiryaev, A. A.

2014-02-01

438

Study with magnetic property measurement of soft magnetic composite material and its application in electrical machines  

Microsoft Academic Search

This paper reports our study with the magnetic property measurements of soft magnetic composite (SMC) materials under both alternating and rotational magnetic excitations, and development of different electrical machines with SMC cores and three-dimensional magnetic field, such as claw pole and transverse flux motors. Three-dimensional finite element electromagnetic field analysis is conducted for determining some important parameters and optimizing the

Jian Guo Zhu; YouGuang Guo

2004-01-01

439

Modeling the magnetic pickup of an electric guitar  

NASA Astrophysics Data System (ADS)

The magnetic pickup of an electric guitar uses electromagnetic induction to convert the motion of a ferromagnetic guitar string to an electrical signal. Although the magnetic pickup is often cited as an everyday application of Faraday's law, few sources mention the distortion that the pickup generates when converting the motion of a string to an electric signal, and fewer analyze and explain this distortion. We model the magnet and ferromagnetic wire as surfaces with magnetic charge and construct an intuitive model that accurately predicts the output of a magnetic guitar pickup. This model can be understood by undergraduate students and provides an excellent learning tool due to its straightforward mathematics and intuitive algorithm. Experiments show that it predicts the change in a magnetic field due to the presence of a ferromagnetic wire with a high degree of accuracy.

Horton, Nicholas G.; Moore, Thomas R.

2009-02-01

440

Comment on "Limit on the Electron Electric Dipole Moment in Gadolinium-Iron Garnet" [arXiv:physics/0509106  

E-print Network

In the paper being commented on it is proposed a new method for the detection of the electron EDM using the solid GdIG. There, it is argued that a sample electric polarization appears when the sample is magnetized; the common belief is that the electron EDM must be collinear with its magnetic moment. All this is objected and it is suggested that the polarization of the sample can be explained by the direct, Lorentz covariant, interaction between B^{a} and an EDM d^{a}.

Tomislav Ivezic

2010-06-14

441

Comment on "Limit on the Electron Electric Dipole Moment in Gadolinium-Iron Garnet" [arXiv:physics/0509106  

E-print Network

In the paper being commented on it is proposed a new method for the detection of the electron EDM using the solid GdIG. There, it is argued that a sample electric polarization appears when the sample is magnetized; the common belief is that the electron EDM must be collinear with its magnetic moment. All this is objected and it is suggested that the polarization of the sample can be explained by the direct, Lorentz covariant, interaction between B^{a} and an EDM d^{a}.

Ivezic, Tomislav

2010-01-01

442

Solder-Filling of a Cicc Cable for the Efda Dipole Magnet  

Microsoft Academic Search

Several prototype Cable-In-Conduit-Conductors (CICC) for the superconducting EDIPO (Efda DIPOle) revealed a degradation of their critical current (Ic) increasing with each loading cycle. The strong Lorentz-forces during operation in combination with the limited support of the single strands against these forces are thought to be the cause of the permanent degradation of the brittle Nb3Sn superconductor from which the multi-stranded

P. Bauer; P. Bruzzone; F. Cau; K. Weiss; A. Portone; E. Salpietro; M. Vogel; A. Vostner

2008-01-01

443

Construction experience with Fermilab-built full length 50mm SSC dipoles  

SciTech Connect

Fourteen full length SSC dipole magnets are being built and tested at Fermilab. Their purpose is to verify the magnet design as well as transfer the construction technology to industry. Magnet design is summarized. Construction problems and their solutions are discussed. Topics include coil winding, curing and measuring, collaring, instrumentation, end clamp installation, yoking and electrical and mechanical interconnection.

Blessing, M.J.; Hoffman, D.E.; Packer, M.D. [General Dynamics Corp., San Diego, CA (United States). Space Systems Div.; Bossert, R.C.; Brandt, J.S.; Carson, J.A.; Delchamps, S.; Ewald, K.D.; Fulton, H.J.; Haggard, J.E.; Jensen, R.H.; Koska, W.; Rihel, R.K.; Robotham, W.F.; Smith, B.E.; Smith, D.J.; Strait, J.B.; Tassotto, G.; Tinsley, D.A.; Wake, M.; Winters, M.; Zimmerman, W.F. [Fermi National Accelerator Lab., Batavia, IL (United States); Gordon, M.; Higinbotham, W.; Sims, R. [Superconducting Super Collider Lab., Dallas, TX (United States)

1992-03-01

444

Nano-scale investigations of electric-dipole-layer enhanced field and thermionic emission from high current density cathodes  

NASA Astrophysics Data System (ADS)

Cesium iodide coated graphitic fibers and scandate cathodes are two important electron emission technologies. The coated fibers are utilized as field emitters for high power microwave sources. The scandate cathodes are promising thermionic cathode materials for pulsed power vacuum electron devices. This work attempts to understand the fundamental physical and chemical relationships between the atomic structure of the emitting cathode surfaces and the superior emission characteristics of these cathodes. Ab initio computational modeling in conjunction with experimental investigations was performed on coated fiber cathodes to understand the origin of their very low turn on electric field, which can be reduced by as much as ten-fold compared to uncoated fibers. Copious amounts of cesium and oxygen were found co-localized on the fiber, but no iodine was detected on the surface. Additional ab initio studies confirmed that cesium oxide dimers could lower the work function significantly. Surface cesium oxide dipoles are therefore proposed as the source of the observed reduction in the turn on electric field. It is also proposed that emission may be further enhanced by secondary electrons from cesium oxide during operation. Thermal conditioning of the coated cathode may be a mechanism by which surface cesium iodide is converted into cesium oxide, promoting the depletion of iodine by formation of volatile gas. Ab initio modeling was also utilized to investigate the stability and work functions of scandate structures. The work demonstrated that monolayer barium-scandium-oxygen surface structures on tungsten can dramatically lower the work function of the underlying tungsten substrate from 4.6 eV down to 1.16 eV, by the formation of multiple surface dipoles. On the basis of this work, we conclude that high temperature kinetics force conventional dispenser cathodes (barium-oxygen monolayers on tungsten) to operate in a non-equilibrium compositional steady state with higher than optimal work functions of ˜2 eV. We hypothesize that scandium enables the barium-oxygen surface monolayer kinetics to access a more thermodynamically stable phase with reported work functions as low as ˜1.3 eV.

Vlahos, Vasilios

445

Storage of electric and magnetic energy in passive nonreciprocal networks  

NASA Technical Reports Server (NTRS)

Examination of the relation of stored electric and magnetic energy within a system to the terminal behavior of nonreciprocal passive networks shows both similarities and important differences between wholly reciprocal systems and systems containing nonreciprocal elements.

Smith, W. E.

1969-01-01

446

Electric and Magnetic Forces between Parallel-Wire Conductors.  

ERIC Educational Resources Information Center

Discusses electric and magnetic forces between parallel-wire conductors and derives, in a simple fashion, order of magnitude estimates of the ratio of the likely electrostatic and electromagnetic forces for a simple parallel-wire balance. (Author/HM)

Morton, N.

1979-01-01

447

Biological Effects of Electrical and Magnetic Fields: Is It Real?  

E-print Network

The hazardous effect of electric and magnetic fields on biological systems is the subject of considerable debate. Traditional methods have failed to provide a correlation between the fields and biological effects. A model is presented that solves...

Durham, M. O.

448

Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets  

E-print Network

This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.

The PANDA Collaboration; W. Erni; I. Keshelashvili; B. Krusche; M. Steinacher; Y. Heng; Z. Liu; H. Liu; X. Shen; O. Wang; H. Xu; J. Becker; F. Feldbauer; F. -H. Heinsius; T. Held; H. Koch; B. Kopf; M. Pelizaeus; T. Schroeder; M. Steinke; U. Wiedner; J. Zhong; A. Bianconi; M. Bragadireanu; D. Pantea; A. Tudorache; V. Tudorache; M. De Napoli; F. Giacoppo; G. Raciti; E. Rapisarda; C. Sfienti; E. Bialkowski; A. Budzanowski; B. Czech; M. Kistryn; S. Kliczewski; A. Kozela; P. Kulessa; K. Pysz; W. Schaefer; R. Siudak; A. Szczurek; W. Czy. zycki; M. Domagala; M. Hawryluk; E. Lisowski; F. Lisowski; L. Wojnar; D. Gil; P. Hawranek; B. Kamys; St. Kistryn; K. Korcyl; W. Krzemien; A. Magiera; P. Moskal; Z. Rudy; P. Salabura; J. Smyrski; A. Wronska; M. Al-Turany; I. Augustin; H. Deppe; H. Flemming; J. Gerl; K. Goetzen; R. Hohler; D. Lehmann; B. Lewandowski; J. Luehning; F. Maas; D. Mishra; H. Orth; K. Peters; T. Saito; G. Schepers; C. J. Schmidt; L. Schmitt; C. Schwarz; B. Voss; P. Wieczorek; A. Wilms; K. -T. Brinkmann; H. Freiesleben; R. Jaekel; R. Kliemt; T. Wuerschig; H. -G. Zaunick; V. M. Abazov; G. Alexeev; A. Arefiev; V. I. Astakhov; M. Yu. Barabanov; B. V. Batyunya; Yu. I. Davydov; V. Kh. Dodokhov; A. A. Efremov; A. G. Fedunov; A. A. Feshchenko; A. S. Galoyan; S. Grigoryan; A. Karmokov; E. K. Koshurnikov; V. Ch. Kudaev; V. I. Lobanov; Yu. Yu. Lobanov; A. F. Makarov; L. V. Malinina; V. L. Malyshev; G. A. Mustafaev; A. Olshevski; M. A. . Pasyuk; E. A. Perevalova; A. A. Piskun; T. A. Pocheptsov; G. Pontecorvo; V. K. Rodionov; Yu. N. Rogov; R. A. Salmin; A. G. Samartsev; M. G. Sapozhnikov; A. Shabratova; G. S. Shabratova; A. N. Skachkova; N. B. Skachkov; E. A. Strokovsky; M. K. Suleimanov; R. Sh. Teshev; V. V. Tokmenin; V. V. Uzhinsky; A. S. Vodopianov; S. A. Zaporozhets; N. I. Zhuravlev; A. G. Zorin; D. Branford; K. Foehl; D. Glazier; D. Watts; P. Woods; W. Eyrich; A. Lehmann; A. Teufel; S. Dobbs; Z. Metreveli; K. Seth; B. Tann; A. Tomaradze; D. Bettoni; V. Carassiti; A. Cecchi; P. Dalpiaz; E. Fioravanti; I. Garzia; M. Negrini; M. Savri`e; G. Stancari; B. Dulach; P. Gianotti; C. Guaraldo; V. Lucherini; E. Pace; A. Bersani; M. Macri; M. Marinelli; R. F. Parodi; I. Brodski; W. Doering; P. Drexler; M. Dueren; Z. Gagyi-Palffy; A. Hayrapetyan; M. Kotulla; W. Kuehn; S. Lange; M. Liu; V. Metag; M. Nanova; R. Novotny; C. Salz; J. Schneider; P. Schoenmeier; R. Schubert; S. Spataro; H. Stenzel; C. Strackbein; M. Thiel; U. Thoering; S. Yang; T. Clarkson; E. Cowie; E. Downie; G. Hill; M. Hoek; D. Ireland; R. Kaiser; T. Keri; I. Lehmann; K. Livingston; S. Lumsden; D. MacGregor; B. McKinnon; M. Murray; D. Protopopescu; G. Rosner; B. Seitz; G. Yang; M. Babai; A. K. Biegun; A. Bubak; E. Guliyev; V. S. Jothi; M. Kavatsyuk; H. Loehner; J. Messchendorp; H. Smit; J. C. van der Weele; F. Garcia; D. -O. Riska; M. Buescher; R. Dosdall; R. Dzhygadlo; A. Gillitzer; D. Grunwald; V. Jha; G. Kemmerling; H. Kleines; A. Lehrach; R. Maier; M. Mertens; H. Ohm; D. Prasuhn; T. Randriamalala; J. Ritman; M. Roeder; T. Stockmanns; P. Wintz; P. Wuestner; J. Kisiel; S. Li; Z. Li; Z. Sun; H. Xu; S. Fissum; K. Hansen; L. Isaksson; M. Lundin; B. Schroeder; P. Achenbach; M. C. Mora Espi; J. Pochodzalla; S. Sanchez; A. Sanchez-Lorente; V. I. Dormenev; A. A. Fedorov; M. V. Korzhik; O. V. Missevitch; V. Balanutsa; V. Chernetsky; A. Demekhin; A. Dolgolenko; P. Fedorets; A. Gerasimov; V. Goryachev; A. Boukharov; O. Malyshev; I. Marishev; A. Semenov; C. Hoeppner; B. Ketzer; I. Konorov; A. Mann; S. Neubert; S. Paul; Q. Weitzel; A. Khoukaz; T. Rausmann; A. Taeschner; J. Wessels; R. Varma; E. Baldin; K. Kotov; S. Peleganchuk; Yu. Tikhonov; J. Boucher; T. Hennino; R. Kunne; S. Ong; J. Pouthas; B. Ramstein; P. Rosier; M. Sudol; J. Van de Wiele; T. Zerguerras; K. Dmowski; R. Korzeniewski; D. Przemyslaw; B. Slowinski; G. Boca; A. Braghieri; S. Costanza; A. Fontana; P. Genova; L. Lavezzi; P. Montagna; A. Rotondi; N. I. Belikov; A. M. Davidenko; A. A. Derevschikov; Y. M. Goncharenko; V. N. Grishin; V. A. Kachanov; D. A. Konstantinov; V. A. Kormilitsin; V. I. Kravtsov; Y. A. Matulenko; Y. M. Melnik; A. P. Meschanin; N. G. Minaev; V. V. Mochalov; D. A. Morozov; L. V. Nogach; S. B. Nurushev; A. V. Ryazantsev; P. A. Semenov; L. F. Soloviev; A. V. Uzunian; A. N. Vasiliev; A. E. Yakutin; T. Baeck; B. Cederwall; C. Bargholtz; L. Geren; P. E. Tegner; S. Belostotski; G. Gavrilov; A. Itzotov; A. Kisselev; P. Kravchenko; S. Manaenkov; O. Miklukho; Y. Naryshkin; D. Veretennikov; V. Vikhrov; A. Zhadanov; L. Fava; D. Panzieri; D. Alberto; A. Amoroso; E. Botta; T. Bressani; S. Bufalino; M. P. Bussa; L. Busso; F. De Mori; M. Destefanis; L. Ferrero; A. Grasso; M. Greco; T. Kugathasan; M. Maggiora; S. Marcello; G. Serbanut; S. Sosio; R. Bertini; D. Calvo; S. Coli; P. De Remigis; A. Feliciello; A. Filippi; G. Giraudo; G. Mazza

2009-07-01

449

Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets  

E-print Network

This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.

Erni, W; Krusche, B; Steinacher, M; Heng, Y; Liu, Z; Liu, H; Shen, X; Wang, O; Xu, H; Becker, J; Feldbauer, F; Heinsius, F -H; Held, T; Koch, H; Kopf, B; Pelizaeus, M; Schröder, T; Steinke, M; Wiedner, U; Zhong, J; Bianconi, A; Bragadireanu, M; Pantea, D; Tudorache, A; Tudorache, V; De Napoli, M; Giacoppo, F; Raciti, G; Rapisarda, E; Sfienti, C; Bialkowski, E; Budzanowski, A; Czech, B; Kistryn, M; Kliczewski, S; Kozela, A; Kulessa, P; Pysz, K; Schäfer, W; Siudak, R; Szczurek, A; zycki, W Czy; Domagala, M; Hawryluk, M; Lisowski, E; Lisowski, F; Wojnar, L; Gil, D; Hawranek, P; Kamys, B; Kistryn, St; Korcyl, K; Krzemien, W; Magiera, A; Moskal, P; Rudy, Z; Salabura, P; Smyrski, J; Wronska, A; Al-Turany, M; Augustin, I; Deppe, H; Flemming, H; Gerl, J; Goetzen, K; Hohler, R; Lehmann, D; Lewandowski, B; Lühning, J; Maas, F; Mishra, D; Orth, H; Peters, K; Saitô, T; Schepers, G; Schmidt, C J; Schmitt, L; Schwarz, C; Voss, B; Wieczorek, P; Wilms, A; Brinkmann, K -T; Freiesleben, H; Jaekel, R; Kliemt, R; Wuerschig, T; Zaunick, H -G; Abazov, V M; Alexeev, G; Arefev, A; Astakhov, V I; Barabanov, M Yu; Batyunya, B V; Davydov, Yu I; Dodokhov, V Kh; Efremov, A A; Fedunov, A G; Feshchenko, A A; Galoyan, A S; Grigorian, S; Karmokov, A; Koshurnikov, E K; Kudaev, V Ch; Lobanov, V I; Lobanov, Yu Yu; Makarov, A F; Malinina, L V; Malyshev, V L; Mustafaev, G A; Olshevski, A; Pasyuk, M A; Perevalova, E A; Piskun, A A; Pocheptsov, T A; Pontecorvo, G; Rodionov, V K; Rogov, Yu N; Salmin, R A; Samartsev, A G; Sapozhnikov, M G; Shabratova, A; Shabratova, G S; Skachkova, A N; Skachkov, N B; Strokovsky, E A; Suleimanov, M K; Teshev, R Sh; Tokmenin, V V; Uzhinsky, V V; Vodopyanov, A S; Zaporozhets, S A; Zhuravlev, N I; Zorin, A G; Branford, D; Föhl, K; Glazier, D; Watts, D; Woods, P; Eyrich, W; Lehmann, A; Teufel, A; Dobbs, S; Metreveli, Z; Seth, K; Tann, B; Tomaradze, A G; Bettoni, D; Carassiti, V; Cecchi, A; Dalpiaz, P; Fioravanti, E; Garzia, I; Negrini, M; Savri`e, M; Stancari, G; Dulach, B; Gianotti, P; Guaraldo, C; Lucherini, V; Pace, E; Bersani, A; Macri, M; Marinelli, M; Parodi, R F; Brodski, I; Döring, W; Drexler, P; Düren, M; Gagyi-Palffy, Z; Hayrapetyan, A; Kotulla, M; Kühn, W; Lange, S; Liu, M; Metag, V; Nanova, M; Novotny, R; Salz, C; Schneider, J; Schoenmeier, P; Schubert, R; Spataro, S; Stenzel, H; Strackbein, C; Thiel, M; Thoering, U; Yang, S; Clarkson, T; Cowie, E; Downie, E; Hill, G; Hoek, M; Ireland, D; Kaiser, R; Keri, T; Lehmann, I; Livingston, K; Lumsden, S; MacGregor, D; McKinnon, B; Murray, M; Protopopescu, D; Rosner, G; Seitz, B; Yang, G; Babai, M; Biegun, A K; Bubak, A; Guliyev, E; Jothi, V S; Kavatsyuk, M; Löhner, H; Messchendorp, J; Smit, H; van der Weele, J C; García, F; Riska, D -O; Büscher, M; Dosdall, R; Dzhygadlo, R; Gillitzer, A; Grunwald, D; Jha, V; Kemmerling, G; Kleines, H; Lehrach, A; Maier, R; Mertens, M; Ohm, H; Prasuhn, D; Randriamalala, T; Ritman, J; Roeder, M; Stockmanns, T; Wintz, P; Wüstner, P; Kisiel, J; Li, S; Li, Z; Sun, Z; Xu, H; Fissum, S; Hansen, K; Isaksson, L; Lundin, M; Schröder, B; Achenbach, P; Espi, M C Mora; Pochodzalla, J; Sanchez, S; Sanchez-Lorente, A; Dormenev, V I; Fedorov, A A; Korzhik, M V; Missevitch, O V; Balanutsa, V; Chernetsky, V; Demekhin, A; Dolgolenko, A; Fedorets, P; Gerasimov, A; Goryachev, V; Boukharov, A; Malyshev, O; Marishev, I; Semenov, A; Hoeppner, C; Ketzer, B; Konorov, I; Mann, A; Neubert, S; Paul, S; Weitzel, Q; Khoukaz, A; Rausmann, T; Täschner, A; Wessels, J; Varma, R; Baldin, E; Kotov, K; Peleganchuk, S; Tikhonov, Yu; Boucher, J; Hennino, T; Kunne, R; Ong, S; Pouthas, J; Ramstein, B; Rosier, P; Sudol, M; Van de Wiele, J; Zerguerras, T; Dmowski, K; Korzeniewski, R; Przemyslaw, D; Slowinski, B; Boca, G; Braghieri, A; Costanza, S; Fontana, A; Genova, P; Lavezzi, L; Montagna, P; Rotondi, A; Belikov, N I; Davidenko, A M; Derevshchikov, A A; Goncharenko, Yu M; Grishin, V N; Kachanov, V A; Konstantinov, D A; Kormilitsin, V A; Kravtsov, V I; Matulenko, Yu A; Melnik, Y M; Meshchanin, A P; Minaev, N G; Mochalov, V V; Morozov, D A; Nogach, L V; Nurushev, S B; Ryazantsev, A V; Semenov, P A; Soloviev, L F; Uzunian, A V; Vasilev, A N; Yakutin, A E; Baeck, T; Cederwall, B; Bargholtz, C; Geren, L; Tegnér, P E; Belostotskii, S; Gavrilov, G; Itzotov, A; Kiselev, A; Kravchenko, P; Manaenkov, S; Miklukho, O; Naryshkin, Yu; Veretennikov, D; Vikhrov, V; Zhadanov, A; Fava, L; Panzieri, D; Alberto, D; Amoroso, A; Botta, E; Bressani, T; Bufalino, S; Bussa, M P; Busso, L; De Mori, F; Destefanis, M; Ferrero, L; Grasso, A; Greco, M; Kugathasan, T; Maggiora, M; Marcello, S; Serbanut, G; Sosio, S; Bertini, R; Calvo, D; Coli, S; De Remigis, P; Feliciello, A; Filippi, A; Giraudo, G; Mazza, G; Rivetti, A; Szymanska, K; Tosello, F; Wheadon, R; Morra, O; Agnello, M; Iazzi, F; Szymanska, K; Birsa, R; Bradamante, F; Bressan, A; Martin, A

2009-01-01

450

Magnetic measurement data of the injector synchrotron dipole magnets for the 7-GeV Advanced Photon Source  

SciTech Connect

The magnetic measurement data of the first 34 of the required 68 production magnets for the injector synchrotron are summarized. The magnetic measurement method of the field strength and field shape relative to a reference magnet is described. The standard deviation of the integrated field strength for the 34 magnets is 3.3 {times} 10{sup {minus}4} and the variation of the integrated field with transverse displacement of {+-}25 mm is less than 2.5 {times} 10{sup {minus}4}.

Kim, K.; Kim, S.H.; Turner, L.R.; Doose, C.L.; Hogrefe, R.; Merl, R.

1993-07-01

451

A method of nerve electrical stimulation by magnetic induction.  

PubMed

The implantable electrical stimulator is usually not suitable for long term use because of its large size and short battery life, besides the magnetic stimulation can not provide deep nerve stimulation. Therefore, this paper developed a method of the electrical stimulation by using the magnetic induction. We implanted a small inductive coil which was connected with nerve electrodes. When the stimulation was applied, a coaxial coil containing a pulsed current was placed outside. So the electrical field evoking the nerve was formed because of the generation of inductive electromotive force in the inductive coil. Finite element analysis was used to analyze the electric field in the nerve and fiber model was used to predict the generation of action potential. This innovative method was applied on the sciatic nerves of rats. EMG was successfully recorded after the electrical stimulation by the magnetic induction. The results demonstrated that this new method was effective to stimulate the deep nerve. PMID:19963975

Zhang, Guanghao; Li, Yue; Huo, Xiaolin; Song, Tao

2009-01-01

452

AC electric field induced dipole-based on-chip 3D cell rotation.  

PubMed

The precise rotation of suspended cells is one of the many fundamental manipulations used in a wide range of biotechnological applications such as cell injection and enucleation in nuclear transfer (NT) cloning. Noticeably scarce among the existing rotation techniques is the three-dimensional (3D) rotation of cells on a single chip. Here we present an alternating current (ac) induced electric field-based biochip platform, which has an open-top sub-mm square chamber enclosed by four sidewall electrodes and two bottom electrodes, to achieve rotation about the two axes, thus 3D cell rotation. By applying an ac potential to the four sidewall electrodes, an in-plane (yaw) rotating electric field is generated and in-plane rotation is achieved. Similarly, by applying an ac potential to two opposite sidewall electrodes and the two bottom electrodes, an out-of-plane (pitch) rotating electric field is generated and rolling rotation is achieved. As a prompt proof-of-concept, bottom electrodes were constructed with transparent indium tin oxide (ITO) using the standard lift-off process and the sidewall electrodes were constructed using a low-cost micro-milling process and then assembled to form the chip. Through experiments, we demonstrate rotation of bovine oocytes of ~120 ?m diameter about two axes, with the capability of controlling the rotation direction and the rate for each axis through control of the ac potential amplitude, frequency, and phase shift, and cell medium conductivity. The maximum observed rotation rate reached nearly 140° s(-1), while a consistent rotation rate reached up to 40° s(-1). Rotation rate spectra for zona pellucida-intact and zona pellucida-free oocytes were further compared and found to have no effective difference. This simple, transparent, cheap-to-manufacture, and open-top platform allows additional functional modules to be integrated to become a more powerful cell manipulation system. PMID:24933556

Benhal, Prateek; Chase, J Geoffrey; Gaynor, Paul; Oback, Björn; Wang, Wenhui

2014-08-01

453

A test of the geocentric axial dipole hypothesis from an analysis of the skewness of the central marine magnetic anomaly  

NASA Astrophysics Data System (ADS)

A new, global set of palaeomagnetic observations was obtained from analysis of the symmetry of the shape of 203 crossings of the Central marine magnetic anomaly, the anomaly observed above seafloor, formed during the Brunhes normal polarity chron (0-0.78 Ma). The data indicate that the time-averaged field can be described best by a dominant geocentric axial dipole component, whose position differs insignificantly from the present spin axis, and by a small geocentric axial quadrupole component (6.0% -6.7%+5.7% the size of the dipole component). If we simply assume that the Brunhes palaeomagnetic axis has been aligned with the present spin axis, the quadrupole component is 6.2% ± 4.7%, which differs significatly from a purely dipolar field, and is in good agreement with estimates from other palaeomagnetic data. Besides expanding the spatial distribution of palaeomagnetic field observations, an important step in removing biases in prior field estimates caused by poor global coverage, these results illustrate that valuable geomagnetic information as well as accurate palaeomagnetic poles can be obtained from skewness data.

Acton, Gary D.; Petronotis, Katerina E.; Cape, Cheryl D.; Ilg, Sue Rotto; Gordon, Richard G.; Bryan, Phil C.

1996-11-01

454

Simulation and Optimization of the Spin Coherent Time for the Proton Electric Dipole Moment Measurement  

SciTech Connect

Work during this quarter has concentrated on (1) lattice development of an â??all-in-oneâ? storage ring lattice for measuring the EDM's of protons, deuterons, and helium-3 nuclei. (2) COSY EDM precursor experiments; especially using an electric bend element borrowed from the Fermilab Tevatron. (3) establishing benchmark lattices for comparing beam evolution codes. My responsibilities have been to design or alter lattices for these storage ring experiments and to guide the development of the UAL/ETEAPOT, enabling it to simulate beam and polarization evolution and survival in these experiments.

Richard Talman

2012-04-01

455

Fabrication and Test Results of a Prototype, Nb3Sn Superconducting Racetrack Dipole Magnet  

SciTech Connect

A prototype, Nb{sub 3}Sn superconducting magnet, utilizing a racetrack coil design has been built and tested. This magnet represents the first step in a recently implemented program to develop a high field, accelerator quality magnet. This magnet was constructed with coils wound from conductor developed for the ITER project, limiting the magnet to a field of 6-7 Tesla. Subsequent magnets in the program will utilize improved conductor, culminating in a magnet design capable of producing fields approaching 15 Tesla. The simple geometry is more suitable for the use of brittle superconductors necessary to eventually reach high field levels. In addition, fewer and simpler parts are used in fabricating these coils compared with the more conventional cosine theta cross section coils. The general fabrication steps, mechanical design and quench performance are discussed.

Gourlay, S. A.; Chow, K.; Dietderich, D.R.; Gupta, R.; Hannaford, R.; Harnden, W.; Lietzke, A.; McInturff, A.D.; Millos, G.A.; Morrison, L.; Morrison, M.; Scanlan, R.M.

1998-09-01