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1

Pulsed Electric Current Dipole/Dipole Interference.  

National Technical Information Service (NTIS)

A time-domain analysis of electromagnetic, pulsed electric current dipole/dipole interference is presented. The emitting and suscepting dipoles may be either 'electric dipoles' (short segments of electric current carrying wire) or 'magnetic dipoles' (smal...

D. Quak A. T. de Hoop

1998-01-01

2

Electric dipoles on magnetic monopoles in spin ice.  

PubMed

The close connection of electricity and magnetism is one of the cornerstones of modern physics. This connection has a crucial role from a fundamental point of view and in practical applications, including spintronics and multiferroic materials. A breakthrough was a recent proposal that in magnetic materials called spin ice the elementary excitations have a magnetic charge and behave as magnetic monopoles. I show that, besides magnetic charge, there should be an electric dipole attached to each magnetic monopole. This opens new possibilities to study and control such monopoles using an electric field. Thus, the electric-magnetic analogy goes even further than usually assumed: whereas electrons have electric charge and magnetic dipole (spin), magnetic monopoles in spin ice, while having magnetic charge, also have an electric dipole. PMID:22713746

Khomskii, D I

2012-06-19

3

Colocated Magnetic Loop, Electric Dipole Array Antenna (Preliminary Results).  

National Technical Information Service (NTIS)

We present a detailed electromagnetic analysis of an electrically small colocated electric dipole and magnetic loop antenna array. This antenna is the simplest example of the Grimes multipole class of antenna arrays. We have determined that since the inte...

P. L. Overfelt D. R. Bowling D. J. White

1994-01-01

4

Quark electric dipole moment induced by magnetic field  

SciTech Connect

We show numerically that quarks develop an electric dipole moment in the direction of a sufficiently intense magnetic field due to local fluctuations of topological charge. This anomalous CP-odd effect is a spin analogue of the chiral magnetic effect in QCD.

Buividovich, P. V. [JINR, Dubna, Moscow region, 141980 (Russian Federation); ITEP, B. Cheremushkinskaya 25, Moscow, 117218 (Russian Federation); Chernodub, M. N. [CNRS, LMPT, Federation Denis Poisson, Universite de Tours, 37200 France (France); DMPA, University of Gent, Krijgslaan 281, S9, B-9000 Gent (Belgium); ITEP, B. Cheremushkinskaya 25, Moscow, 117218 (Russian Federation); Luschevskaya, E. V.; Polikarpov, M. I. [ITEP, B. Cheremushkinskaya 25, Moscow, 117218 (Russian Federation)

2010-02-01

5

Quantum phase of an electric dipole moving in a magnetic dipole field  

NASA Astrophysics Data System (ADS)

It is shown that a neutral particle with an electric dipole moment acquires a quantum phase of Aharonov-Bohm type which is induced by a magnetic dipole field, in addition to the He-McKellar-Wilkens phase which requires a magnetic monopole field. Therefore this phase is measurable in principle. This phase is related to the Casella phase in the sense of the electromagnetic duality.

Lee, Tae-Yeon

2000-12-01

6

Dark-matter electric and magnetic dipole moments  

SciTech Connect

We consider the consequences of a neutral dark-matter particle with a nonzero electric and/or magnetic dipole moment. Theoretical constraints, as well as constraints from direct searches, precision tests of the standard-model, the cosmic microwave background and matter power spectra, and cosmic gamma rays, are included. We find that a relatively light particle with mass between an MeV and a few GeV and an electric or magnetic dipole as large as {approx}3x10{sup -16}e cm (roughly 1.6x10{sup -5}{mu}{sub B}) satisfies all experimental and observational bounds. Some of the remaining parameter space may be probed with forthcoming more sensitive direct searches and with the Gamma-Ray Large Area Space Telescope.

Sigurdson, Kris; Kurylov, Andriy; Kamionkowski, Marc [California Institute of Technology, Mail Code 130-33, Pasadena, California 91125 (United States); Doran, Michael; Caldwell, Robert R. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, New Hampshire 03755 (United States)

2004-10-15

7

Dark-matter electric and magnetic dipole moments  

Microsoft Academic Search

We consider the consequences of a neutral dark-matter particle with a nonzero electric and\\/or magnetic dipole moment. Theoretical constraints, as well as constraints from direct searches, precision tests of the standard-model, the cosmic microwave background and matter power spectra, and cosmic gamma rays, are included. We find that a relatively light particle with mass between an MeV and a few

Kris Sigurdson; Michael Doran; Andriy Kurylov; Robert R. Caldwell; Marc Kamionkowski

2004-01-01

8

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

9

Thermodynamics of a continuous medium with electric and magnetic dipoles  

NASA Astrophysics Data System (ADS)

The thermodynamics of an electrically charged, multicomponent fluid with spontaneous electric and magnetic dipoles is analysed in the presence of electromagnetic fields. Taking into account the chemical composition of the current densities and stress tensors leads to three types of irreversible terms: scalars, vectors and pseudo-vectors. The scalar terms account for chemical reactivities, the vectorial terms account for transport and the pseudo-vectorial terms account for relaxation. The linear phenomenological relations, derived from the irreversible evolution, describe notably the Lehmann and electric Lehmann effects, the Debye relaxation of polar molecules and the Landau-Lifshitz relaxation of the magnetisation. This formalism accounts for the thermal and electric magnetisation accumulations and magnetisation waves. It also predicts that a temperature gradient affects the dynamics of magnetic vortices and drives magnetisation waves.

Brechet, Sylvain D.; Ansermet, Jean-Philippe

2013-07-01

10

Magnetic Johnson noise constraints on electron electric dipole moment experiments  

SciTech Connect

Magnetic fields from statistical fluctuations in currents in conducting materials broaden atomic linewidths by the Zeeman effect. The constraints imposed by this broadening on the design of experiments that measure the electric dipole moment of the electron are analyzed. Contrary to the predictions of Lamoreaux [S. K. Lamoreaux, Phys. Rev. A 60, 1717 (1999)], the standard material for high-permeability magnetic shields proves to be as significant a source of broadening as is an ordinary metal. A scheme that would replace this standard material with ferrite is proposed.

Munger, Charles T. Jr. [Stanford Linear Accelerator Center, 2575 Sand Hill Road, Mail Stop 59, Menlo Park, California 94025 (United States) and Lawrence Berkeley National Laboratory, Mail Stop 71-259, Berkeley, California 94320 (United States)

2005-07-15

11

Magnetic Johnson Noise Constraints on Electron Electric Dipole Moment Experiments  

SciTech Connect

Magnetic fields from statistical fluctuations in currents in conducting materials broaden atomic linewidths by the Zeeman effect. The constraints so imposed on the design of experiments to measure the electric dipole moment of the electron are analyzed. Contrary to the predictions of Lamoreaux [S.K. Lamoreaux, Phys. Rev. A60, 1717(1999)], the standard material for high-permeability magnetic shields proves to be as significant a source of broadening as an ordinary metal. A scheme that would replace this standard material with ferrite is proposed.

Munger, C.

2004-11-18

12

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

13

Resonant electric dipole-dipole interactions between cold Rydberg atoms in a magnetic field  

NASA Astrophysics Data System (ADS)

Laser cooled 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 electric dipole-dipole interactions between atoms in these two states were probed using the linewidth of the two-photon microwave transitions 46d5/2 -- 47d5/2. The presence of a weak magnetic field (roughly 1 G) reduced the observed line broadening, indicating that the interaction is suppressed by the field. The field removes some of the energy degeneracies responsible foe the resonant interaction, and this is the basis for a quantitative model of the resulting suppression. A technique for the calibration of magnetic field strengths using the 34s1/2 -- 34p1/2 one-photon transition is also presented.

Afrousheh, Kourosh; Bohlouli-Zanjani, Parisa; Carter, Jeffery; Mugford, Ashton; Martin, James D. D.

2006-05-01

14

Electric and magnetic dipole moments of the bound system of a Dirac particle and a fixed magnetic monopole  

Microsoft Academic Search

The electric and the magnetic dipole moments are calculated for the bound states of a charged Dirac particle of spin 1\\/2 with an extra magnetic moment in the field of a fixed magnetic monopole. Unlike ordinary bound systems with P and\\/or T invariance, this system, lacking both, is found to possess a nonvanishing electric dipole moment. Its magnitude for the

Yoichi Kazama

1977-01-01

15

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

16

Energy balance problems in systems of induced and permanent electric and magnetic dipoles  

Microsoft Academic Search

There are many problems where a detailed understanding of the interaction energy of systems of dipoles is needed, including electrorheological and magnetorheological fluids, ferrofluids, magnetic composites, and dielectrics. We have constructed soluble microscopic problems involving electric and magnetic dipoles to investigate energy balance, and have come to some understanding of the proper form of the dipolar free energy in aggregations

Robert A. Anderson; James E. Martin

2002-01-01

17

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

18

Two-Cascade Magnetic Field Stabilizer of the Installation for Measuring Neutron Electric Dipole Moment.  

National Technical Information Service (NTIS)

A two-cascade magnetic field stabilizer of installation for the measurement of neutron electrical dipole moment (EDM) using ultracold neutrons has been constructed and tested. Quantum cesium magnetometers (QCM) with optical pumping placed inside a ferroma...

A. N. Kozlov Y. V. Nikitenko Y. V. Taran

1980-01-01

19

Electric and weak magnetic-dipole-moment effects in e+e--->l+l-  

Microsoft Academic Search

We consider the weak effects in e+e--->l+l- that come, not from neutral currents, but from possible muon or heavy-lepton electric dipole moments, and from weak corrections to magnetic dipole moments. We show that in the coming experiments on this reaction, these weak effects can safely be ignored.

Robert Budny; Boris Kayser; Joel Primack

1977-01-01

20

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

21

Modification of electric and magnetic dipole emission in anisotropic plasmonic systems.  

PubMed

In order to investigate the effects of plasmonic environments on spontaneous emission of magnetic and electric dipoles, we have studied luminescence of Eu3+ ions in close vicinity to gold nanostrip arrays. Significant changes in the emission kinetics, emission polarization, and radiation patterns have been observed in the wavelength range corresponding to the plasmonic resonance. The effect of the plasmonic resonance on the magnetic dipole transition 5D0?7F1 is found to be very different from its effect on the electric dipole transitions. This makes Eu3+-containing complexes promising for mapping local distributions of magnetic and electric fields in metamaterials and plasmonic systems. PMID:24104224

Noginova, N; Hussain, R; Noginov, M A; Vella, J; Urbas, A

2013-10-01

22

Electric and anomalous magnetic dipole moments of the muon in the MSSM  

Microsoft Academic Search

We study the electric dipole moment (EDM) and the anomalous magnetic dipole moment (MDM) of the muon in the CP-violating Minimal Supersymmetric extension of the Standard Model (MSSM). We take into account the contributions from the chargino- and neutralino-mediated one-loop graphs and the dominant two-loop Higgs-mediated Barr-Zee diagrams. We improve earlier calculations by incorporating CP-violating Higgs-boson mixing effects and the

Kingman Cheung; Otto C. W. Kong; Jae Sik Lee

2009-01-01

23

Quantum phases of electric and magnetic dipoles as special cases of the Aharonov-Bohm phase  

NASA Astrophysics Data System (ADS)

It is shown that the vector potential of the Aharonov-Bohm effect is effectively the same as vector potentials of the quantum phases of electric and magnetic dipoles such as the Aharonov-Casher effect, when the Aharonov-Bohm solenoid is a straight cylinder with symmetric cross sections. With a circular cross section, the Aharonov-Bohm vector potential is effectively the same as the Aharonov-Casher vector potential, while with a rectangular cross section, it is effectively the same as the vector potential of the Casella phase. Therefore, we may say that the quantum phases of the dipoles belong to a subclass of the Aharonov-Bohm phase, and they must share the topological origin of the Aharonov-Bohm phase, even though their topological freedom is limited to the particle trajectories. However, the dipole phases have the extra relativistic effect that a magnetic (electric) dipole moving in an electric (magnetic) field feels an additional magnetic (electric) field, in its rest frame. This effect limits further the topological freedom of the dipole phases.

Lee, Tae-Yeon

2001-09-01

24

Ratio of electric quadrupole to magnetic dipole amplitudes in the nucleon-delta transition  

SciTech Connect

We have analyzed available data on magnetic dipole and electric quadrupole amplitudes for the photoproduction of pions around the delta region, in the framework of a phenomenological ..gamma..N..delta.. interaction and background. The unitarity constraint via Watson's theorem limits severely the range of allowed gauge couplings in the ..gamma..N..delta.. vertex. We obtain (-1.5 +- 0.2)% as the ratio of the electric quadrupole to magnetic dipole resonant amplitudes, a value of the same order of magnitude as predicted in the skyrmion model of baryons. This ratio suggests a deformed structure of the nucleon and the delta isobar.

Davidson, R.; Mukhopadhyay, N.C.; Wittman, R.

1986-02-24

25

Magnetic flux and lines of force for the Hertzian electric dipole and nonsinusoidal waves  

Microsoft Academic Search

The authors present computer plots of magnetic lines of force for the Hertzian electric dipole excited by sinusoidal currents that radiate to the far-field electromagnetic waves with the time variation of a Gaussian pulse. Plots of lines of force for sinusoidal waves are also presented for comparison. Since the density of the lines of force at any distance from the

M. G. M. Hussain; A. A. Omar

1990-01-01

26

On the radiation Q and the gain of crossed electric and magnetic dipole moments  

Microsoft Academic Search

Exact expressions for the radiation quality factor Q and the gain pattern function of the corresponding antenna are derived and their properties are analyzed for crossed electric and magnetic dipole moment configuration. Both omni-directional and directional antennas with linear, elliptical, or circular polarization can achieve the same minimum radiation Q. The maximum gain of the antenna ranges from 3\\/2 to

Do-Hoon Kwon

2005-01-01

27

Lepton electric and magnetic dipole moments via lepton flavor-violating spin-1 unparticle interactions  

SciTech Connect

The magnetic dipole moment and the electric dipole moment of leptons are calculated under the assumption of lepton flavor violation (LFV) induced by spin-1 unparticles with both vector and axial-vector couplings to leptons, including a CP-violating phase. The experimental limits on the muon magnetic dipole moment and LFV process, such as the decay l{sub i}{sup -}{yields}l{sub j}{sup -}l{sub k}{sup -}l{sub k}{sup +}, are then used to constrain the LFV couplings for particular values of the unparticle operator dimension d{sub U} and the unparticle scale {Lambda}{sub U}, assuming that LFV transitions between the tau and muon leptons are dominant. It is found that the current experimental constraints favor a scenario with dominance of the vector couplings over the axial-vector couplings. We also obtain estimates for the electric dipole moments of the electron and the muon, which are well below the experimental values.

Moyotl, A.; Rosado, A.; Tavares-Velasco, G. [Instituto de Fisica, Benemerita Universidad Autonoma de Puebla, Apartado Postal 72570, Puebla (Mexico); Facultad de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Apartado Postal 1152, Puebla (Mexico)

2011-10-01

28

Electric dipole moments, cluster metallicity, and the magnetism of rare earth clusters  

Microsoft Academic Search

One of the fundamental properties of bulk metals is the cancellation of electric fields. The free charges inside of a metal will move until they find an arrangement where the internal electric field is zero. This implies that the electric dipole moment of a metal particle should be exactly zero, because an electric dipole moment requires a net separation of

John Bowlan

2010-01-01

29

Magnetic g_e-FACTORS and Electric Dipole Moments of Lanthanide Monoxides: PrO  

NASA Astrophysics Data System (ADS)

The very complex optical spectra of the lanthanide monoxides are caused by the insensitivity of the electronic energies to the numerous possible arrangements of the Ln^{2+} electrons in the 4f and 6s orbitals. Disentangling the complex optical spectra may be aided by using simple Ligand Field Theory(LFT) to establish the global electronic structure for the low-lying electronic states. A comparison of experimentally determined permanent electric dipole moments, ?_{el}, and magnetic dipole moments, ?_{m}, is an effective means of sorting this myriad of states and assessing the quality of LFT and other electronic structure methodologies. Here we report on the determination of the permanent electric dipole moments, ?_{el}, and magnetic g{_e}-factors for the X_{2}(? = 4.5) and [18.1] (? = 5.5) states of PrO from the analysis of the optical Stark and Zeeman spectra. The g_{e}-factors are compared with those computed using wavefunctions predicted from ligand field theory. The ?_{el} value for the X_{2}(? = 4.5) state is compared to ab initio, and density functional predictions and with the experimental values of other lanthanide monoxides. A phenomenological fit of ?_{el} for the entire series of LnO is used to predict ?_{el} for the isovalent actinide monoxide series. Carette, P.,; Hocquet,A. J. Mol. Spectrosc. 131 301, 1988. Dolg, M.; Stoll, H. Theor. Chim. Acta. 75,369, 1989. Wu, Z.; Guan, W. Meng, J. Su, Z. J. Cluster Science 18 444, 2007.

Wang, Hailing; Steimle, Timothy C.; Linton, Colan

2009-06-01

30

Electric and anomalous magnetic dipole moments of the muon in the MSSM  

NASA Astrophysics Data System (ADS)

We study the electric dipole moment (EDM) and the anomalous magnetic dipole moment (MDM) of the muon in the CP-violating Minimal Supersymmetric extension of the Standard Model (MSSM). We take into account the contributions from the chargino- and neutralino-mediated one-loop graphs and the dominant two-loop Higgs-mediated Barr-Zee diagrams. We improve earlier calculations by incorporating CP-violating Higgs-boson mixing effects and the resummed threshold corrections to the Yukawa couplings of the charged leptons as well as that of the bottom quark. The analytic correlation between the muon EDM and MDM is explicitly presented at one- and two-loop levels and, through several numerical examples, we illustrate its dependence on the source of the dominant contributions. We have implemented the analytic expressions for the muon EDM and MDM in an updated version of the public code CPsuperH2.0.

Cheung, Kingman; Kong, Otto C. W.; Lee, Jae Sik

2009-06-01

31

Quantum dynamics of magnetic and electric dipoles and the geometric phase  

NASA Astrophysics Data System (ADS)

We study the quantum dynamics of a neutral particle that posseses a permanent magnetic and electric dipole moments in the presence of an electromagnetic field. The analysis of this dynamics demonstrates the appearance of a quantum phase that combines the Aharonov-Casher effect and the He-Mckellar-Wilkens effect. We demonstrate that this phase is a special case of the geometric quantum phase. A series of field configurations where this phase would be found is presented. A generalized Casella-type effect is found in one of these configurations. A physical scenario for the quantum phase in an interferometric experiment is proposed.

Furtado, Claudio; Ribeiro, Carlos Alberto

2004-06-01

32

Electric quadrupole and magnetic dipole transition probabilities within the ground configuration of F+  

NASA Astrophysics Data System (ADS)

The radiative lifetime of the 2s22p4 1S0 level in F+ has been measured by time-resolved observations of both strong (though electric-dipole forbidden) decay branches: the electric quadrupole (E2) transition (~80% branch) to the 2s22p4 1D2 level and the magnetic dipole (M1) transition (~20% branch) to the 2s22p4 3P1 level. We observed the fluorescence associated with both transitions from a population of F+ ions circulating in a heavy-ion storage ring. Our result for the F+ 2s22p4 1S0 level lifetime of 420+/-12 ms provides a benchmark for theory. Moreover, although the calculated lifetimes vary by more than 20%, the calculated branching fractions vary by less than 4% and 7% for the 1S0-->1D2 E2 and 1S0-->3P1 M1 transitions, respectively. Using our measured lifetime and the calculated branching fractions, we report semiempirical transition probabilities for the 1S0-->1D2 E2 and 1S0-->3P1 M1 transitions of 1.90 s-1+/-7% and 0.50 s-1+/-9%, respectively.

Calamai, A. G.; Gwinner, G.; Tordoir, X.; Träbert, E.; Wolf, A.

2000-06-01

33

? weak magnetic dipole moment  

Microsoft Academic Search

The weak magnetic dipole moment of the ?-lepton is reviewed. Standard Model predictions and the last experimental results are presented. These may result in a stringent test for both their point-like structure and also for new physics.

Gabriel Gonza´lez-Sprinberg

1998-01-01

34

Limits on the Weak Electric and Magnetic Dipole Moments of the ? from Azimuthal Asymmetries  

NASA Astrophysics Data System (ADS)

The ? flight direction is reconstructed for 5012 Z^0arrow ?^+ ?^- decays, with the ?'s decaying into ??_? or ??_?. >From azimuthal asymmetries we perform measurements of the electric weak dipole moment d^w_? and the anomalous weak magnetic moment a^w_?. The preliminary results are d_?^w = (0.39 ± 1.23 ± 1.72) × 10-17 e \\cdot cm, Re(a_?^w) = -0.0022 ± 0.0022 ± 0.0031 and Im(a_?^w) = -0.0064 ± 0.0051 ± 0.0070. Corresponding upper limits at the 95% confidence level are |d_?^w| < 4.52 × 10-17 e \\cdot cm, |Re(a_?^w)| < 0.0096 and |Im(a_?^w)| < 0.0234

L3 Collaboration

1997-04-01

35

Direct modulation of lanthanide emission at sub-lifetime scales using electric and magnetic dipole transition  

NASA Astrophysics Data System (ADS)

Lanthanide ions, such as trivalent Europium (Eu3+) and Erbium (Er3+) are technologically important, high quantum yield light emitters that exhibit both magnetic dipole (MD) and electric dipole (ED) transitions. It is well know that the transition rate of an emitter in an inhomogenous optical environment, e.g. an emitter near a mirror, is modified due to self-interference effects, leading to either enhancement or inhibition of spontaneous emission. However, due to the opposite symmetry of their emitted fields, ED and MD transitions exhibit differing self-interference. Here, we leverage this difference to show large spectral tuning and sub-lifetime dynamic modulation of Eu3+ emission. Specifically, we use a moving gold mirror to selectively enhance the ED and MD transitions in Eu3+ doped Y2O3. Controlling the emitter-mirror distance allows us to tune the emission spectra from 580 nm to 715 nm. Modulating the mirror position with a piezoelectric crystal allows us to dynamically tune the Eu3+ emission at speeds faster than the excited state lifetime.

Karaveli, Sinan; Weinstein, Aaron J.; Zia, Rashid

2012-02-01

36

Quantum-Mechanical Description of the Electromagnetic Interaction of Relativistic Particles with Electric and Magnetic Dipole Moments  

Microsoft Academic Search

The Hamiltonian of relativistic particles with electric and magnetic dipole moments that interact with an electromagnetic\\u000a field is determined in the Foldy-Wouthuysen representation. Transition to the semiclassical approximation is carried out.\\u000a The quantum-mechanical and semiclassical equations of spin motion are derived.

A. Ya. Silenko

2005-01-01

37

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

38

How to introduce the magnetic dipole moment  

Microsoft Academic Search

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 magnetic field at distant points, identifying

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

2012-01-01

39

Possible Binding of a Magnetic Monopole to a Particle with Electric Charge and a Magnetic Dipole Moment  

Microsoft Academic Search

The author argues that Dirac monopoles, if they exist, could be strongly bound to those naturally occuring free nuclei with magnetic dipole moments, and discusses the effect this binding would have on the interpretation of experimental monopole searches.

Dennis Sivers

1970-01-01

40

Magnetic dipole transitions in the hydrogen molecule  

SciTech Connect

In homonuclear molecules, such as H{sub 2}, the electric dipole transitions are strongly forbidden, and the transitions between rovibrational states are of the electric quadrupole type. We show, however, that magnetic dipole transitions also take place, although they are significantly weaker. We evaluate the probabilities of such transitions between several of the lowest rotational states and compare them with those of the corresponding electric quadrupole transitions.

Pachucki, Krzysztof [Institute of Theoretical Physics, University of Warsaw, Hoza 69, PL-00-681 Warsaw (Poland); Komasa, Jacek [Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, PL-60-780 Poznan (Poland)

2011-03-15

41

Bound states for an induced electric dipole in the presence of an azimuthal magnetic field and a disclination  

SciTech Connect

Based on the Wei-Han-Wei setup [H. Wei, R. Han, and X. Wei, Phys. Rev. Lett. 75, 2071 (1995)], where a neutral particle with an induced electric dipole moment interacts with a configuration of crossed electric and magnetic fields, in this paper we study the bound states that arise when we change the Wei-Han-Wei field configuration and consider a field configuration of crossed azimuthal magnetic field and a radial electric field. Moreover, we consider here a spin-half neutral particle and the presence of a linear topological defect called disclination. We obtain the bound states in two distinct cases: in the first case, we consider that the wave function of the neutral particle is well-behaved at the origin and vanishes at the asymptotic limit; in the second case, we consider the neutral particle confined to a parabolic potential like a quantum dot.

Bakke, K. [Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU (United Kingdom)

2010-09-15

42

Electric quadrupole and magnetic dipole moments of the first excited 2 + states of 186 Os and 188 Os  

Microsoft Academic Search

The spectroscopic quadrupole moments and the magnetic dipole moments of the lowest 2+ states in186Os (137 keV) and188Os (155 keV) have been determined by Mößbauer transmission experiments. The electric quadrupole momentsQ2+(Os 186)=- (1.80±0.22) b andQ2+(Os 188)=-(1.81±0.24) b as well as their ratioQ2+(Os 188)\\/Q2+(Os 186)=1.00±0.07 within the limits of error agree withB(E2) data, if a comparison on the basis of the

F. Wagner; D. Kucheida; G. Kaindl; P. Kienle

1970-01-01

43

Magnetic dipole and electric quadrupole transitions in the trivalent lanthanide series: Calculated emission rates and oscillator strengths  

NASA Astrophysics Data System (ADS)

Given growing interest in optical-frequency magnetic dipole transitions, we use intermediate coupling calculations to identify strong magnetic dipole emission lines that are well suited for experimental study. The energy levels for all trivalent lanthanide ions in the 4fn configuration are calculated using a detailed free ion Hamiltonian, including electrostatic and spin-orbit terms as well as two-body, three-body, spin-spin, spin-other-orbit, and electrostatically correlated spin-orbit interactions. These free ion energy levels and eigenstates are then used to calculate the oscillator strengths for all ground-state magnetic dipole absorption lines and the spontaneous emission rates for all magnetic dipole emission lines including transitions between excited states. A large number of strong magnetic dipole transitions are predicted throughout the visible and near-infrared spectrum, including many at longer wavelengths that would be ideal for experimental investigation of magnetic light-matter interactions with optical metamaterials and plasmonic antennas.

Dodson, Christopher M.; Zia, Rashid

2012-09-01

44

Dipole Moments of Weak, Electrically Small Emitters from TEM-Cell Measurements.  

National Technical Information Service (NTIS)

The report presents a new method for determining the equivalent electric and magnetic dipole moments of an electrically small emitter from TEM-cell measurements. The electric dipole moments are determined from open-circuit measurements, and the magnetic d...

D. A. Hill K. H. Cavcey

1998-01-01

45

CrRb: A molecule with large magnetic and electric dipole moments  

SciTech Connect

We report calculations of Born-Oppenheimer potential energy curves of the chromium-rubidium heteronuclear molecule ({sup 52}Cr{sup 87}Rb), and the long-range dispersion coefficient for the interaction between ground state Cr and Rb atoms. Our calculated van der Waals coefficient (C{sub 6}=1770 a.u.) has an expected error of 3%. The ground state {sup 6{Sigma}+} molecule at its equilibrium separation has a permanent electric dipole moment of d{sub e}(R{sub e}=3.34Angstrom)=2.90 D. We investigate the hyperfine and dipolar collisions between trapped Cr and Rb atoms, finding elastic to inelastic cross section ratio of 10{sup 2}-10{sup 3}.

Pavlovic, Z. [ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046 (United States); Sadeghpour, H. R. [ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States); Cote, R. [Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046 (United States); Roos, B. O. [Department of Theoretical Chemistry, University of Lund, S-221 00 Lund (Sweden)

2010-05-15

46

Super strong permanent dipole magnet  

Microsoft Academic Search

The authors have been developing very strong permanent magnets. In the past, our magnets could generate greater than 5 Tesla dipole fields. We are now in a process of reaching much higher fields. The present paper is devoted to describing magnetic design developments in order to obtain super strong magnetic fields (of order of several Tesla magnitudes) with permanent magnets

Masayuki Kumada; Evgeny I. Antokhin; Yoshihisa Iwashita; Masaaki Aoki; Eiji Sugiyama

2004-01-01

47

Time-Resolved Energy-Momentum Spectroscopy of Electric and Magnetic Dipole Transitions in Cr(3+):MgO.  

PubMed

Due to the recent interest in magnetic light-matter interactions, the magnetic dipole (MD) transitions in lanthanide ions have been studied for potential applications in nano-optics. Similar to lanthanide ions, transition-metal ions also exhibit strong MD emission at room temperature, but their prominent MD zero-phonon lines are often accompanied by significant electric dipole (ED) sideband emission. Here, we extend energy-momentum spectroscopy to time-resolved measurements, and use this technique to quantify the ED and MD contributions to light emission from trivalent chromium doped magnesium oxide (Cr(3+):MgO). This allows us to differentiate the MD (2)E ? (4)A2 zero-phonon line from phonon-assisted (2)E ? (4)A2 and (4)T2 ? (4)A2 ED sidebands. We also demonstrate how the relative intensities of the sharp MD zero-phonon line and the broad ED sidebands can be used as a qualitative measure of the MD and ED local density of optical states. PMID:23879390

Karaveli, Sinan; Wang, Shutong; Xiao, Gang; Zia, Rashid

2013-07-26

48

Magnetic dipole and electric quadrupole rotational structures and chirality in 105 Rh  

NASA Astrophysics Data System (ADS)

The 105 Rh nucleus has been studied with the 100 Mo ( 11 B ,?2n? ) reaction at 43 MeV incident energy. A rich variety of structures was observed at high and low spins, using ?-?-t and ?-?-particle coincidences and directional correlation ratios. A ? -vibrational band was observed for the first time in this nucleus. A new structure based on the intruder 1/ 2+ [431] proton orbital was identified. Four magnetic dipole bands have also been observed at high spin, three of which have negative parity and have similar characteristics: they are very regular in energy spacing, presenting nearly constant alignments and large values of B(M1)/B(E2) ratios. Two of them are nearly degenerate in excitation energy and could be chiral partners. The ? g9/2 ?? h11/2 ( g7/2 , d5/2 ) configuration is tentatively assigned for these bands, with the angular momenta of the proton and neutron intruders and the collective angular momentum aligning along the three perpendicular axes of the triaxial core, as predicted by tilted axis cranking calculations.

Alcántara-Núñez, J. A.; Oliveira, J. R.; Cybulska, E. W.; Medina, N. H.; Rao, M. N.; Ribas, R. V.; Rizzutto, M. A.; Seale, W. A.; Falla-Sotelo, F.; Wiedemann, K. T.; Dimitrov, V. I.; Frauendorf, S.

2004-02-01

49

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

50

Two-loop supersymmetric corrections to lepton anomalous magnetic and electric dipole moments  

SciTech Connect

Using the effective Lagrangian method, we analyze the electroweak corrections to the anomalous dipole moments of leptons from some special two-loop topological diagrams which are composed of neutralino-slepton (chargino-sneutrino) in the minimal supersymmetric extension of the standard model (MSSM). Considering the translational invariance of the inner loop momenta and the electromagnetic gauge invariance, we get all dimension six operators and derive their coefficients. After applying equations of motion to the external leptons, the anomalous dipole moments of leptons are obtained. The numerical results imply that there is a parameter space where the two-loop supersymmetric corrections to the muon anomalous dipole moments may be significant.

Feng Taifu [Department of Physics, Dalian University of Technology, Dalian 116024 (China); Department of Physics, University of Jyvaeskylae, Fin-40014 (Finland); Center for Theoretical Physics, Seoul National University, Seoul, 151-742 (Korea, Republic of); Li Xueqian [Department of Physics, Nankai University, Tianjin 300071 (China); Lin Lin; Song Heshan [Department of Physics, Dalian University of Technology, Dalian 116024 (China); Maalampi, Jukka [Department of Physics, University of Jyvaeskylae, Fin-40014 (Finland)

2006-06-01

51

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

52

Ab initio Calculation of Electric Quadrupole and Magnetic Dipole Transitions in Ions of the N I Isoelectronic Sequence  

NASA Astrophysics Data System (ADS)

The electric quadrupole (E2) and magnetic dipole (M1) transitions in the nitrogen isoelectronic sequence (Z=10-30) between the levels of the 1s22s22p3, 1s22s2p4 and 1s22p5 configurations are investigated. The results include wavelengths and radiative E2 and M1 transition probabilities. The stationary second-order many-body perturbation theory (MBPT) was used to account for the electron correlations. A non-local potential was used to calculate the radial part of the effective Hamiltonian. Relativistic corrections were included in the Breit-Pauli approximation. The lowest-order correlation corrections to the one-body part of the spin-orbit interaction operator were also included.

Merkelis, G.; Martinson, I.; Kisielius, R.; Vilkas, M. J.

53

Electric and magnetic dipole transitions to bound states in /sup 206/Pb  

SciTech Connect

Nuclear resonance fluorescence measurements with linearly polarized bremsstrahlung were performed to determine parities of bound dipole transitions in /sup 206/Pb. A new 1/sup +/ level at 5800 keV was found, which has almost the same strength as the isoscalar M1 transition in /sup 208/Pb. Twenty-four further dipole states in /sup 206/Pb below 7.6 MeV possess negative parity.

Ratzek, R.; Berg, U.E.P.; Blasing, C.; Jung, A.; Schennach, S.; Stock, R.; Urban, F.; Wickert, H.

1986-02-10

54

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

NASA Astrophysics Data System (ADS)

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, 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

55

Locating a Buried Magnetic Dipole  

Microsoft Academic Search

Five measurements of the magnetic-field vector near the surface of the earth are shown to be sufficient to determine the orientation and location of a buried magnetic dipole. A discussion of field experiments which demonstrate the location concept is included.

Thurlow W. H. Caffey; Louis Romero

1982-01-01

56

Transient electric and magnetic fields associated with establishing a finite electrostatic dipole, revisited  

Microsoft Academic Search

The authors reexamine the analysis of M.J. Master and M.A. Uman (1983), who derived and plotted the electromagnetic field waveforms generated by a square wave of current propagating with constant speed along a finite linear path, resulting in the formation of a finite electrostatic dipole. It was concluded that such a square pulse of current had charge only at its

M. Rubinstein; M. A. Uman

1991-01-01

57

{tau} weak magnetic dipole moment  

SciTech Connect

The weak magnetic dipole moment of the {tau}-lepton is reviewed. Standard Model predictions and the last experimental results are presented. These may result in a stringent test for both their point-like structure and also for new physics.

Gonzalez-Sprinberg, Gabriel [Facultad de Ciencias, Universidad de la Rep'ublica Montevideo (Uruguay)

1998-10-05

58

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

NASA Astrophysics Data System (ADS)

The model (Lagrangian) with a peculiar extra U(1) [S. M. Barr and I. Dorsner, Phys. Rev. DPRVDAQ1550-7998 10.1103/PhysRevD.72.01501172, 015011 (2005); S. M. Barr and A. Khan, Phys. Rev. DPRVDAQ1550-799810.1103/PhysRevD.74.085023 74, 085023 (2006)] is clearly presented. The assigned extra U(1) gauge charges give a strong constraint to build Lagrangians. The Z' 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???1 [6°?arg?(A)?90°].

Heo, Jae Ho

2009-08-01

59

On the origin dependence of the angle made by the electric and magnetic vibrational transition dipole moment vectors.  

PubMed

The concept of robustness of rotational strengths of vibrational modes in a VCD spectrum has been introduced as an aid in assignment of the absolute configuration with the help of the VCD spectrum. The criteria for robustness have been based on the distribution around 90° of the angles ?(i) between electric and magnetic transition dipoles of all the modes i of a molecule. The angles ?(i) (not, of course, the rotational strengths) are, however, dependent on the choice of origin. The derived criteria are for the center of mass chosen as the origin of the coordinate system. We stress in this note that application of the derived criteria assumes that excessive translation of the coordinate origin is not applied. Although the ?(i) angles are not very sensitive to the position of the origin, very small displacements (a few Å) are not a problem, excessive translation of the origin does have considerable effect on the ?(i) angles. In this note we quantify this effect and demonstrate how the distribution of ?(i) angles is affected. Although it is possible to recalibrate the robustness criteria for the angles for a specific (large) displacement, we recommend that such displacement simply be avoided. It is to be noted that some modeling software does yield output with excessively displaced coordinate origin; this should be checked and corrected. PMID:21842037

Nicu, Valentin Paul; Baerends, Evert Jan

2011-08-12

60

Measuring the Forces between Magnetic Dipoles  

ERIC Educational Resources Information Center

|We describe a simple undergraduate lab in which students determine how the force between two magnetic dipoles depends on their separation. We consider the case where both dipoles are permanent and the case where one of the dipoles is induced by the field of the other (permanent) dipole. Agreement with theoretically expected results is quite good.|

Gayetsky, Lisa E.; Caylor, Craig L.

2007-01-01

61

Measuring the Forces between Magnetic Dipoles  

ERIC Educational Resources Information Center

We describe a simple undergraduate lab in which students determine how the force between two magnetic dipoles depends on their separation. We consider the case where both dipoles are permanent and the case where one of the dipoles is induced by the field of the other (permanent) dipole. Agreement with theoretically expected results is quite good.

Gayetsky, Lisa E.; Caylor, Craig L.

2007-01-01

62

Paramagnetic Resonance Absorption in Uranium (III) Chloride and the Nuclear Spin, Magnetic Dipole Moment, and Electric Quadrupole Moment of Uranium233  

Microsoft Academic Search

Paramagnetic resonance absorption in single crystals of U233Cl3 diluted with LaCl3 has been investigated. The values of the parameters in the appropriate Hamiltonian are given. The values of the nuclear spin, magnetic dipole moment, and electric quadrupole moment obtained from these studies are discussed. The ratios of the mo ments of U235 and U233, which can be obtained with much

Paul B. Dorain; Clyde A. Hutchison; Eugene Wong

1957-01-01

63

A Spacecraft Magnetic Dipole Moment Determination Method  

Microsoft Academic Search

To learn about the magnitude of the magnetic dipole moment of a spacecraft that will orbit under the influence of the Earth magnetic field, is fundamental in terms of predicting the disturbances that will eventually arise from this interaction with the Earth magnetic field due to magnetic forces. Keeping the total residual magnetic dipole moment at tolerable value is of

Marco A. Strobino

2002-01-01

64

Tailoring magnetic dipole emission with plasmonic split-ring resonators.  

PubMed

We numerically explore the emission behavior of magnetic dipole emitters located next to resonant plasmonic split-ring resonators (SRRs), which are well known for their large magnetic moment at their fundamental resonance in the near infrared. Our results are compared to the situation for electric dipole emitters, where the SRR can be described by solely its electric dipole moment. We show that a similar approach in the case of magnetic dipole emitters is not sufficient, as the symmetry breaking due to the gap has to be taken into account. We demonstrate how retardation between the emitter and the SRR can be used as an additional degree of freedom to manipulate the emission spectrum. Our concept will pave the road towards efficient plasmonic antennas for magnetic dipole emitters. PMID:23889429

Hein, Sven M; Giessen, Harald

2013-07-10

65

Tailoring Magnetic Dipole Emission with Plasmonic Split-Ring Resonators  

NASA Astrophysics Data System (ADS)

We numerically explore the emission behavior of magnetic dipole emitters located next to resonant plasmonic split-ring resonators (SRRs), which are well known for their large magnetic moment at their fundamental resonance in the near infrared. Our results are compared to the situation for electric dipole emitters, where the SRR can be described by solely its electric dipole moment. We show that a similar approach in the case of magnetic dipole emitters is not sufficient, as the symmetry breaking due to the gap has to be taken into account. We demonstrate how retardation between the emitter and the SRR can be used as an additional degree of freedom to manipulate the emission spectrum. Our concept will pave the road towards efficient plasmonic antennas for magnetic dipole emitters.

Hein, Sven M.; Giessen, Harald

2013-07-01

66

Magnetic Field of a Dipole and the Dipole-Dipole Interaction  

ERIC Educational Resources Information Center

|With a data-acquisition system and sensors commercially available, it is easy to determine magnetic fields produced by permanent magnets and to study the dipole-dipole interaction for different separations and angular positions of the magnets. For sufficiently large distances, the results confirm the 1/R[superscript 3] law for the magnetic field…

Kraftmakher, Yaakov

2007-01-01

67

Dipole Relaxation in an Electric Field.  

ERIC Educational Resources Information Center

Derives an expression for the orientational entropy of a rigid rod (electric dipole) from Boltzmann's equation. 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. (Author/GS)

Neumann, Richard M.

1980-01-01

68

Gravitational radiation reaction in compact binary systems: Contribution of the magnetic dipole magnetic dipole interaction  

Microsoft Academic Search

We study the gravitational radiation reaction in compact binary systems composed of neutron stars with spin and huge magnetic dipole moments (magnetars). The magnetic dipole moments undergo a precessional motion about the respective spins. At sufficiently high values of the magnetic dipole moments, their interaction generates second post-Newtonian order contributions both to the equations of motion and to the gravitational

Mátyás Vasúth; Zoltán Keresztes; András Mihály; László Á. Gergely

2003-01-01

69

Dynamics of an electric dipole moment in a stochastic electric field  

NASA Astrophysics Data System (ADS)

The mean-field dynamics of an electric dipole moment in a deterministic and a fluctuating electric field is solved to obtain the average over fluctuations of the dipole moment and the angular momentum as a function of time for a Gaussian white-noise stochastic electric field. The components of the average electric dipole moment and the average angular momentum along the deterministic electric-field direction do not decay to zero, despite fluctuations in all three components of the electric field. This is in contrast to the decay of the average over fluctuations of a magnetic moment in a stochastic magnetic field with Gaussian white noise in all three components. The components of the average electric dipole moment and the average angular momentum perpendicular to the deterministic electric-field direction oscillate with time but decay to zero, and their variance grows with time.

Band, Y. B.

2013-08-01

70

Dynamics of an electric dipole moment in a stochastic electric field.  

PubMed

The mean-field dynamics of an electric dipole moment in a deterministic and a fluctuating electric field is solved to obtain the average over fluctuations of the dipole moment and the angular momentum as a function of time for a Gaussian white-noise stochastic electric field. The components of the average electric dipole moment and the average angular momentum along the deterministic electric-field direction do not decay to zero, despite fluctuations in all three components of the electric field. This is in contrast to the decay of the average over fluctuations of a magnetic moment in a stochastic magnetic field with Gaussian white noise in all three components. The components of the average electric dipole moment and the average angular momentum perpendicular to the deterministic electric-field direction oscillate with time but decay to zero, and their variance grows with time. PMID:24032795

Band, Y B

2013-08-15

71

Effect of Magnetic Dipole Moment on Magnet Forces  

Microsoft Academic Search

This paper discusses the effect of magnetic dipole moment on the ``lifting power'' of permanent magnets and on forces between magnets. To within the precision of observations, stacking identical magnets end-to-end appears to increase the dipole moment of a magnet in direct proportion to the material length of the magnet. This convenience facilitates a wide range of experiments that can

Ken Taylor; Ian Campbell; Matthew Mirochna; Robbie Stewart

2008-01-01

72

SSC collider dipole magnet end mechanical design  

Microsoft Academic Search

The authors describe the mechanical design of the ends of Superconducting Super Collider (SSC) dipole magnets to be constructed and tested at Fermilab. Coil end clamps, end yoke configuration, and end plate design are discussed. Loading of the end plate by axial Lorentz forces is examined. Relevant data from 40 mm and 50 mm aperture model dipole magnets built and

S. W. Delchamps; R. C. Bossert; J. Carson; K. Ewald; H. Fulton; J. Kerby; W. Koska; J. Strait; M. Wake; K. K. Leung

1991-01-01

73

Dynamic magnetization reversal in dipole systems  

NASA Astrophysics Data System (ADS)

The possibility of magnetization reversal in two different systems of magnetic dipoles by preliminary excitation of certain oscillatory regimes is demonstrated using numerical analysis of bistable states of these systems. Cyclic magnetization reversal of the systems is executed by sequential alternation of the frequency of the applied ac field. The interaction of two ring-shaped dipole systems is analyzed and peculiarities of the change in the total magnetic moments induced by this interaction are revealed.

Shutyi, A. M.

2013-06-01

74

Magnetic Dipole Field 3D Model  

NSDL National Science Digital Library

The Magnetic Dipole Field 3D Model displays the field lines and field vectors of a dipole located at the origin and oriented along the z-axis. Users can compute the field line passing through a point by dragging the a marker within the 3D view. Users can also visualize the field vectors in a plane passing though the center of the dipole. The Magnetic Dipole Field 3D Model was developed using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_em_MagneticDipole3D.jar file will run the program if Java is installed. EJS is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models.

Christian, Wolfgang

2012-08-11

75

Zeeman slower based on magnetic dipoles  

Microsoft Academic Search

In this paper it is proposed to use a periodic array of very strong and compact neodymium magnets to create the desired magnetic field of the Zeeman slower. A model of the slower based on point-like magnetic dipoles has been introduced, which is a key element in designing of such type of a slower. The high precision of that simple

Yuri B. Ovchinnikov

2007-01-01

76

Detailed discussion of a linear electric field frequency shift induced in confined gases by a magnetic field gradient: Implications for neutron electric-dipole-moment experiments  

SciTech Connect

The search for particle electric dipole moments (EDM's) is one of the best places to look for physics beyond the standard model of electroweak interaction because the size of time reversal violation predicted by the standard model is incompatible with present ideas concerning the creation of the baryon-antibaryon asymmetry. As the sensitivity of these EDM searches increases more subtle systematic effects become important. We develop a general analytical approach to describe a systematic effect recently observed in an electric dipole moment experiment using stored particles [J. M. Pendlebury et al., Phys. Rev. A 70, 032102 (2004)]. Our approach is based on the relationship between the systematic frequency shift and the velocity autocorrelation function of the resonating particles. Our results, when applied to well-known limiting forms of the correlation function, are in good agreement with both the limiting cases studied in recent work that employed a numerical and heuristic analysis. Our general approach explains some of the surprising results observed in that work and displays the rich behavior of the shift for intermediate frequencies, which has not been studied previously.

Lamoreaux, S.K. [University of California, Los Alamos National Laboratory, Physics Division, Los Alamos, New Mexico 87545 (United States); Golub, R. [Physics Department, North Carolina State University, Raleigh, North Carolina 27606 (United States)

2005-03-01

77

A Zeeman slower based on magnetic dipoles  

Microsoft Academic Search

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

Yuri B. Ovchinnikov

2007-01-01

78

Magnetic field decay in model SSC dipoles  

Microsoft Academic Search

The authors 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

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

1989-01-01

79

Dipole Experiment with Magnetically Isolated Supports  

NASA Astrophysics Data System (ADS)

Basics plasma physics experiments in the collisionless regimes require good plasma confinement to permit temperatures and densities in the range of Te˜30 eV, n ˜1.10^19 m-3. Our design for a new magnetic reconnection experiment is based on the confinement of the dipole geometry which has also been considered for fusion applications (e.i. the LDX experiment at MIT). Rather than magnetic levitation as applied in the LDX experiment, we use magnetically isolated supports. This magnetic isolation is achieved by applying currents in the support structures configuring the magnetic field such that the plasma cannot stream directly to the support along magnetic field lines. We here report on the first magnetic and electrostatic measurements in this dipole configuration.

Montag, P.; Egedal, J.; Vrublevskis, A.; Le, A.; Fox, W.

2012-10-01

80

Dipole-field contributions to geometric-phase-induced false electric-dipole-moment signals for particles in traps  

SciTech Connect

It has been shown in an earlier publication [J. Pendlebury et al. Phys. Rev. A 70, 032102 (2004)] that magnetic-field gradients applied to particles in traps can induce Larmor frequency shifts that may falsely be interpreted as electric-dipole moment signals. This study has now been extended to include nonuniform magnetic-field gradients due to the presence of a local magnetic dipole. It is found that, in the high orbit-frequency regime, .the magnitude of the shifts can be enhanced beyond the simple expectation of proportionality to the volume-averaged magnetic-field gradient <{partial_derivative}B{sub z}/{partial_derivative}z>.

Harris, P. G.; Pendlebury, J. M. [Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom)

2006-01-15

81

Recent developments in neutron electric dipole moment and related CP violating quantities  

SciTech Connect

We summarize recent theoretical developments in CP violation related to the neutron electric dipole moment, chromo-electric dipole moments for quarks, chromo-electric dipole moment for gluon, and electric dipole moments for electron and W boson. 31 refs.

Chang, D. (Northwestern Univ., Evanston, IL (USA). Dept. of Physics and Astronomy Fermi National Accelerator Lab., Batavia, IL (USA))

1990-12-20

82

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

83

Conductor fabrication for ISABELLE dipole magnets  

Microsoft Academic Search

Fabrication techniques and specifications are discussed for the ; composite superconductor braids to be used in the dipole magnets of the ISABELLE ; Storage Rings. Properties of the NbTi and Cu composite superconductor are given, ; the braid parameters are presented, and the fabrication processes are shown in ; photographs. (PMA)

McInturff

1975-01-01

84

Magnetic Dipole Moment of the Bhabha System  

Microsoft Academic Search

A systematic procedure was recently developed for extracting the intrinsic moments of a system described by the general first-order linear field equation (ibetamu?mu+k)psi=0. The procedure is here applied to compute the magnetic dipole moments of a dibaric system proposed by Bhabha.

Robert L. Pease; Jane Pease

1957-01-01

85

Magnetic Dipole Moment of RV Alliance.  

National Technical Information Service (NTIS)

A SACLANTCEN magnetometry sea trial was performed in September 1998 in the northern Tyrrhenian Sea in the vicinity of the Formiche di Grosseto islands. One of the trial objectives concerned the measurement of the magnetic dipole moment of the NATO researc...

J. Watermann

1999-01-01

86

Magnetic dipole moment integrals over Slater orbitals  

Microsoft Academic Search

General expressions for all magnetic dipole moment integrals over Slater-type orbitals are presented in a form suitable for ready computation. The two-center integrals are expressed concisely in terms of the C functions introduced by Ruedenberg, Roothaan, and Jaunzemis.

Hideo Ichimura; Arvi Rauk

1973-01-01

87

SSC collider dipole magnet end mechanical design.  

National Technical Information Service (NTIS)

This paper describes the mechanical design of the ends of Superconducting Super Collider dipole magnets to be constructed and tested at Fermilab. Coil end clamps, end yoke configuration, and end plate design are discussed. Loading of the end plate by axia...

S. W. Delchamps R. C. Bossert J. Carson K. Ewald H. Fulton

1991-01-01

88

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

89

Stability of superconducting ISABELLE dipole magnets  

SciTech Connect

The concept of the minimum propagating zone (MPZ) is used to examine the causes of quenches in ISABELLE cosine theta superconducting dipole magnets. The size of disturbances large enough to exceed the MPZ and initiate quenches is estimated and compared with the size of disturbances which may be produced in the magnets. A suggestion for reducing the size of these disturbances through individual support of the coil block is outlined.

Wipf, S.L.

1981-04-01

90

The Submillimeter and Millimeter Excess of the Small Magellanic Cloud: Magnetic Dipole Emission from Magnetic Nanoparticles?  

NASA Astrophysics Data System (ADS)

The Small Magellanic Cloud (SMC) has surprisingly strong submillimeter- and millimeter-wavelength emission that is inconsistent with standard dust models, including those with emission from spinning dust. Here, we show that the emission from the SMC may be understood if the interstellar dust mixture includes magnetic nanoparticles, emitting magnetic dipole radiation resulting from thermal fluctuations in the magnetization. The magnetic grains can be metallic iron, magnetite Fe3O4, or maghemite ?-Fe2O3. The required mass of iron is consistent with elemental abundance constraints. The magnetic dipole emission is predicted to be polarized orthogonally to the normal electric dipole radiation if the nanoparticles are inclusions in larger grains. We speculate that other low-metallicity galaxies may also have a large fraction of the interstellar Fe in magnetic materials.

Draine, B. T.; Hensley, Brandon

2012-09-01

91

THE SUBMILLIMETER AND MILLIMETER EXCESS OF THE SMALL MAGELLANIC CLOUD: MAGNETIC DIPOLE EMISSION FROM MAGNETIC NANOPARTICLES?  

SciTech Connect

The Small Magellanic Cloud (SMC) has surprisingly strong submillimeter- and millimeter-wavelength emission that is inconsistent with standard dust models, including those with emission from spinning dust. Here, we show that the emission from the SMC may be understood if the interstellar dust mixture includes magnetic nanoparticles, emitting magnetic dipole radiation resulting from thermal fluctuations in the magnetization. The magnetic grains can be metallic iron, magnetite Fe{sub 3}O{sub 4}, or maghemite {gamma}-Fe{sub 2}O{sub 3}. The required mass of iron is consistent with elemental abundance constraints. The magnetic dipole emission is predicted to be polarized orthogonally to the normal electric dipole radiation if the nanoparticles are inclusions in larger grains. We speculate that other low-metallicity galaxies may also have a large fraction of the interstellar Fe in magnetic materials.

Draine, B. T.; Hensley, Brandon, E-mail: draine@astro.princeton.edu [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States)

2012-09-20

92

New experimental limit on the electron electric dipole moment  

SciTech Connect

A search for the electron electric dipole moment {ital d}{sub {ital e}} is carried out with two counterpropagating beams of ground-state {sup 205}Tl. The experiment employs atomic-beam magnetic resonance with separated oscillatory fields combined with laser state selection and fluorescence detection. Extensive tests were made for possible systematic effects. The result for the atomic electric dipole moment is {ital d}{sub {ital a}}=(1.6 {plus minus}5.0){times}10{sup {minus}24} {ital e} cm, where the uncertainty includes equal statistical and systematic contributions. This yields {ital d}{sub {ital e}}=({minus}2.7{plus minus}8.3) {times}10{sup {minus}27} {ital e} cm, assuming the ratio {ital d}{sub {ital a}}/{ital d}{sub {ital e}}={minus}600.

Abdullah, K.; Carlberg, C.; Commins, E.D.; Gould, H.; Ross, S.B. (Chemical Sciences Division, Building 71-259, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, CA (USA) Department of Physics, University of California, Berkeley, CA (USA))

1990-11-05

93

The Electric Dipole Form Factor of the Nucleon  

NASA Astrophysics Data System (ADS)

We use chiral perturbation theory in next-to-leading order to calculate the electric dipole form factor of the nucleon at low momentum. We consider effects from sources of time-reversal violation in the Standard Model up to effective dimension six: the QCD theta angle, the light quarks' electric and color-electric dipole moments, and the gluon color-electric dipole moment.

van Kolck, U.; Mereghetti, E.; de Vries, J.; Timmermans, R. G. E.

2011-04-01

94

MUON G-2 AND ELECTRIC DIPOLE MOMENTS IN STORAGE RINGS: POWERFUL PROBES OF PHYSICS BEYOND THE STANDARD MODEL.  

SciTech Connect

We have shown that the study of dipole moments, both magnetic and electric, in storage rings offer unique opportunities in probing physics beyond the Standard Model (SM). Both methods use similar techniques (particle and spin precession in magnetic storage rings). We are currently investigating the systematic errors associated with the resonance electric dipole moment (EDM) method. So far it looks very promising.

SEMERTZIDIS, Y.K.

2005-05-23

95

SSC superconducting dipole magnet cryostat model style B construction experience  

SciTech Connect

A program to upgrade the full scale SSC dipole magnet cryostat model function and assembly methods has resulted in a series of dipole magnets designated as style B construction. New design features and assembly techniques have produced a magnet and cryostat assembly that is the basis for Phase 1 of the SSC dipole magnet industrialization program. Details of the assembly program, assembly experience, and comparison to previous assembly experiences are presented. Improvements in magnet assembly techniques are also evaluated. 6 refs., 5 figs.

Engler, N.H.; Bossert, R.C.; Carson, J.A.; Gonczy, J.D.; Larson, E.T.; Nicol, T.H.; Niemann, R.C.; Sorensen, D.; Zink, R.

1989-03-01

96

Nuclear magnetic dipole moments from NMR spectra  

Microsoft Academic Search

In the procedure applied to extract the magnetic dipole moments of bare nuclei from NMR spectra of molecules the shielding of nuclei by electrons has been often described in a very crude manner. We determine the moments for 13C, 14N, 15N, 17O, 19F, 31P and 33S using more accurate shielding constants. Our gas phase NMR data are next used to

Andrej Antusek; Karol Jackowski; Micha? Jaszu?ski; Wlodzimierz Makulski; Marcin Wilczek

2005-01-01

97

Ac loss measurement of SSC dipole magnets  

SciTech Connect

AC losses in full length and 1.5 m model SSC collider dipoles were successfully measured by the direct observation of energy flow into and out of magnets during a ramp cycle. The measurement was performed by using two double-integrating type digital volt meters (DVM`s) for current and voltage measurement. Measurements were performed for six is m long ASST magnets and five 1.5 m long model magnets, inducting one 40 mm diameter magnet. There were large variations in the eddy current losses. Since these magnets use conductors with slight deviations in their internal structures and processing of the copper surface depending on the manufacturer, it is likely that there are differences in the contact resistance between strands. Correlation between the ramp rate dependence of the,quench current and the eddy current loss was evident.

Delchamps, S.; Hanft, R.; Jaffery, T.; Kinney, W.; Koska, W.; Lamm, M.J.; Mazur, P.O.; Orris, D.; Ozelis, J.P.; Strait, J.; Wake, M.

1992-09-01

98

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

99

Gravitational Waves from Inspiraling Compact Binaries with Magnetic Dipole Moments  

Microsoft Academic Search

We investigate the effects of magnetic dipole-dipole coupling and electromagnetic radiation on the frequency evolution of gravitational waves from inspiraling binary neutron stars with magnetic dipole moments. This study is motivated by the discovery of superstrongly magnetized neutron stars, i.e., magnetars. We derive the contributions of the magnetic fields to the accumulated cycles in gravitational waves as Nmag~6×10-3(H\\/1016 G)2, where

Kunihito Ioka; Keisuke Taniguchi

2000-01-01

100

Electron electric-dipole-moment experiment using electric-field quantized slow cesium atoms  

SciTech Connect

A proof-of-principle electron electric-dipole-moment (e-EDM) experiment using slow cesium atoms, nulled magnetic fields, and electric-field quantization has been performed. With the ambient magnetic fields seen by the atoms reduced to less than 200 pT, an electric field of 6 MV/m lifts the degeneracy between states of unequal |m{sub F}| and, along with the low ({approx_equal}3 m/s) velocity, suppresses the systematic effect from the motional magnetic field. The low velocity and small residual magnetic field have made it possible to induce transitions between states and to perform state preparation, analysis, and detection in regions free of applied static magnetic and electric fields. This experiment demonstrates techniques that may be used to improve the e-EDM limit by two orders of magnitude, but it is not in itself a sensitive e-EDM search, mostly due to limitations of the laser system.

Amini, Jason M.; Munger, Charles T. Jr.; Gould, Harvey [Mail Stop 71-259, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2007-06-15

101

Prospects for 10T accelerator dipole magnets  

SciTech Connect

A next-generation major accelerator will require the highest possible field to minimize the circumference; however, there have been no proven designs for suitable magnets with fields substantially higher than 5T. A number of successful 4 to 5T dipole magnets have been built in recent years; these have involved long and difficult development projects. The 3'' bore 4.25T magnets for the Doubler are being produced by the hundreds at Fermilab, and a number of prototypes of the 5.2'' bore 5T ISABELLE magnets have been built. Successful short, approx. 5T models have been made at SACLAY, KEK, and Serpukhov, and a number of model magnets with lower fields have been built at many laboratories. Field uniformity achieved in these magnets is about ..delta..B/B approx. = 10/sup -3/. 10T magnets with higher field uniformity will be a challenging development task. The general problems of high-field (10T) magnets are discussed in terms of superconductor performance and mechanical limitations.

Taylor, C.E.; Meuser, R.B.

1981-03-01

102

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

103

Nuclear electric dipole moment of 3He  

NASA Astrophysics Data System (ADS)

In the no-core shell model (NCSM) framework, we calculate the 3He electric dipole moment (EDM) generated by parity- and time-reversal violation in the nucleon-nucleon interaction. While the results are somehow sensitive to the interaction model chosen for the strong two- and three-body interactions, we demonstrate the pion-exchange dominance to the EDM of 3He, if the coupling constants for ?, ? and ?-exchanges are of comparable magnitude, as expected. Finally, our results suggest that a measurement of 3He EDM would be complementary to the currently planned neutron and deuteron experiments, and would constitute a powerful constraint to the models of the pion P- and T-violating interactions.

Stetcu, I.; Liu, C.-P.; Friar, J. L.; Hayes, A. C.; Navrátil, P.

2009-01-01

104

Nuclear electric dipole moment of 3He  

SciTech Connect

In the no-core shell model (NCSM) framework, we calculate the {sup 3}He electric dipole moment (EDM) generated by parity- and time-reversal violation in the nucleon-nucleon interaction. While the results are somehow sensitive to the interaction model chosen for the strong two- and three-body interactions, we demonstrate the pion-exchange dominance to the EDM of {sup 3}He, if the coupling constants for {pi}, {rho} and {omega}-exchanges are of comparable magnitude, as expected. Finally, our results suggest that a measurement of {sup 3}He EDM would be complementary to the currently planned neutron and deuteron experiments, and would constitute a powerful constraint to the models of the pion P- and T-violating interactions.

Stetcu, Ionel [Los Alamos National Laboratory; Friar, J L [Los Alamos National Laboratory; Hayes, A C [Los Alamos National Laboratory; Liu, C P [UNIV WISCONSIN; Navratil, P [LIVERMORE NAT LAB

2008-01-01

105

The neutron electric dipole moment and the Weinberg mechanism  

SciTech Connect

We gave an overview of various mechanism for CP violation paying special attention to their prediction of the neutron electric dipole moment. The implication of the recent developments associated with the color electric dipole moment of gluon in various models of CP-violation are then critically assessed. 25 refs.

Chang, D. (Northwestern Univ., Evanston, IL (USA). Dept. of Physics and Astronomy Fermi National Accelerator Lab., Batavia, IL (USA))

1990-01-01

106

Electron electric dipole moment experiment using electric-fieldquantized slow cesium atoms  

SciTech Connect

A proof-of-principle electron electric dipole moment (e-EDM)experiment using slow cesium atoms, nulled magnetic fields, and electricfield quantization has been performed. With the ambient magnetic fieldsseen by the atoms reduced to less than 200 pT, an electric field of 6MV/m lifts the degeneracy between states of unequal lbar mF rbar and,along with the low (approximately 3 m/s) velocity, suppresses thesystematic effect from the motional magnetic field. The low velocity andsmall residual magnetic field have made it possible to induce transitionsbetween states and to perform state preparation, analysis, and detectionin regions free of applied static magnetic and electric fields. Thisexperiment demonstrates techniques that may be used to improve the e-EDMlimit by two orders of magnitude, but it is not in itself a sensitivee-EDM search, mostly due to limitations of the laser system.

Amini, Jason M.; Munger Jr., Charles T.; Gould, Harvey.

2007-04-05

107

Electric-Field Induced Dipole Blockade with Rydberg Atoms  

SciTech Connect

High resolution laser Stark excitation of np (60dipole-dipole interaction. The dipole blockade effect is observed as a quenching of the Rydberg excitation depending on the value of the dipole moment induced by the external electric field. Effects of ions which could match the dipole blockade effect are discussed in detail but are ruled out for our experimental conditions. Analytic and Monte Carlo simulations of the excitation of an ensemble of interacting Rydberg atoms agree with the experiments and indicate a major role of the nearest neighboring Rydberg atom.

Vogt, Thibault; Viteau, Matthieu; Chotia, Amodsen; Zhao Jianming; Comparat, Daniel; Pillet, Pierre [Laboratoire Aime Cotton, CNRS, Universite Paris-Sud, Batiment 505, Campus d'Orsay, 91405 Orsay (France)

2007-08-17

108

Role of dipole-dipole interactions for hyperthermia heating of magnetic nanoparticle ensembles  

NASA Astrophysics Data System (ADS)

For clinical hyperthermia treatment the heating efficiency of magnetic nanoparticle ensembles is a crucial element. Using efficient algorithms, this heating is studied numerically with a focus on the effects of dipole-dipole interparticle interactions. For the time evolution of realistically modeled systems an approach based on the Landau-Lifschitz-Gilbert equation of motion with Langevin dynamics is taken. Our results suggest a widely negative influence of dipole-dipole interactions on the heating power of nanoparticles. However, considering ensembles within a fixed, given sample volume an optimal particle density exists. The presented results may have important implications for the medical use of magnetic hyperthermia treatment.

Haase, C.; Nowak, U.

2012-01-01

109

Space propulsion by fusion in a magnetic dipole  

SciTech Connect

The unique advantages of fusion rocket propulsion systems for distant missions are explored using the magnetic dipole configurations as an example. The dipole is found to have features well suited to space applications. Parameters are presented for a system producing a specific power of kW/kg, capable of interplanetary flights to Mars in 90 days and to Jupiter in a year, and of extra-solar-system flights to 1000 astronomical units (the Tau mission) in 20 years. This is about 10 times better specific power performance than nuclear electric fission systems. Possibilities to further increase the specific power toward 10 kW/kg are discussed, as is an approach to implementing the concept through proof-testing on the moon. 20 refs., 14 figs., 2 tabs.

Teller, E.; Glass, A.J.; Fowler, T.K. (Lawrence Livermore National Lab., CA (United States)); Hasegawa, A. (AT and T Bell Labs., Murray Hill, NJ (United States)); Santarius, J.F. (Wisconsin Univ., Madison, WI (United States). Fusion Technology Inst.)

1991-07-15

110

Soft Electric Dipole Modes in Heavy Nuclei:. Some Selected Examples  

NASA Astrophysics Data System (ADS)

Two examples of our recent work on the structure of low-energy electric dipole modes are presented. The first part discusses attempts to unravel the structure of the pygmy dipole resonance (PDR) and possible evidence for a vortex-type electric dipole mode below the giant dipole resonance (GDR) in 208Pb with a high-resolution measurement of the (?cp, ?cp') reaction under 0°. The second part presents the systematics of the PDR in stable tin isotopes deduced from high-resolution (?, ?') experiments and its comparison to studies of the exotic neutron-rich isotopes 130,132Sn at GSI using Coulomb breakup.

von Neumann-Cosel, P.

2008-04-01

111

Concentric Titled Double-Helix Dipole Magnets  

SciTech Connect

The high magnetic fields required for future accelerator magnets can only be achieved with Nb3Sn, other A15 or HTS type conductors, which are brittle and sensitive to mechanical strain. The traditional ''cosine-theta'' dipole configuration has intrinsic drawbacks that make it difficult and expensive to employ such conductors in these designs. Some of these problems involve (1) difficulty in applying enough pre-stress to counteract Lorentz forces without compromising conductor performance; (2) small minimum bend radii of the conductor necessitating the intricate wind-and-react coil fabrication; (3) complex spacers in particular for coil ends and expensive tooling for coil fabrication; (4) typically only 2/3 of the coil aperture can be used with achievable field uniformity.

Rainer Meinke, Ph.D; Carl Goodzeit; Millicent Ball, Ph.D

2003-09-05

112

Quench propagation in the SSC dipole magnets  

SciTech Connect

The effects of quench propagation are modeled in 40mm and 50mm diameter collider dipole magnet designs. A comparative study of the cold diode (passive) and quench heater (active) protection schemes will be presented. The SSCQ modeling program accurately simulates the axial quench velocity and uses phenomenological time delays for turn-to-turn transverse propagation. The axial quench velocity is field dependent and consequently, each conductor's quench profile is tracked separately. No symmetry constraints are employed and the distribution of the temperatures along the conductor differs from the adiabatic approximation. A single magnet has a wide margin of self protection which suggests that passive protection schemes must be considered. 6 refs., 3 figs., 1 tab.

Lopez, G.; Snitchler, G.

1990-09-01

113

MAGNETIC DESIGN OF DIPOLES FOR LHC INSERTION REGIONS  

Microsoft Academic Search

Abstract Anumber,of dipole ,magnets ,for the insertion regions of the Large Hadron Collider (LHC) will be built at BNL. All these magnets ,will have ,the 80 mm aperture ,coil design used for the RHIC arc dipoles. An oblate shaped yoke with a vertical height of 550 mm is ,developed ,for the twin aperture D4A and D4B dipoles. This design allows

A. Jain; R. Gupta; P. Wanderer; E. Willen

1998-01-01

114

The residual permanent magnetic dipole moment of the moon  

Microsoft Academic Search

The residual dipole moment of the outer spherical shell of the Moon, magnetized in the field of an internal dipole is calculated for the case when the permeability of the shell differs from unity. It is shown that, using an average value of surface magnetization from returned lunar crystalline rock samples and a global figure for the lunar permeability of

A. Stephenson

1976-01-01

115

Helical dipole magnets for polarized protons in RHIC  

SciTech Connect

Superconducting helical dipole magnets will be used in the Brookhaven Relativistic Heavy Ion Collider (RHIC) to maintain polarization of proton beams and to perform localized spin rotations at the two major experimental detector regions. Requirements for the helical dipole system are discussed, and magnet prototype work is reported.

Syphers, M.; Courant, E.; Fischer, W. [and others

1997-07-01

116

Nuclear Electric Dipole Moment of 3He  

SciTech Connect

A permanent electric dipole moment (EDM) of a physical system would require time-reversal (T) violation, which is equivalent to charge-conjugation-parity (CP) violation by CPT invariance. Experimental programs are currently pushing the limits on EDMs in atoms, nuclei, and the neutron to regimes of fundamental theoretical interest. Nuclear EDMs can be studied at ion storage rings with sensitivities that may be competitive with atomic and neutron measurements. Here we calculate the magnitude of the CP-violating EDM of {sup 3}He and the expected sensitivity of such a measurement to the underlying CP-violating interactions. Assuming that the coupling constants are of comparable magnitude for {pi}-, {rho}-, and {omega}-exchanges, we find that the pion-exchange contribution dominates. Finally, our results suggest that a measurement of the {sup 3}He EDM is complementary to the planned neutron and deuteron experiments, and could provide a powerful constraint for the theoretical models of the pion-nucleon P,T-violating interaction.

Stetcu, I; P.Liu, C; Friar, J L; Hayes, A C; Navratil, P

2008-04-08

117

Electric dipole moments in the MSSM reloaded  

NASA Astrophysics Data System (ADS)

We present a detailed study of the Thallium, neutron, Mercury and deuteron electric dipole moments (EDMs) in the CP-violating Minimal Supersymmetric extension of the Standard Model (MSSM). We take into account the complete set of one-loop graphs, the dominant Higgs-mediated two-loop diagrams, the complete CP-odd dimension-six Weinberg operator and the Higgs-mediated four-fermion operators. We improve upon earlier calculations by including the resummation effects due to CP-violating Higgs-boson mixing and to threshold corrections to the Yukawa couplings of all up- and down-type quarks and charged leptons. As an application of our study, we analyse the EDM constraints on the CPX, trimixing and Maximally CP- and Minimally Flavour-Violating (MCPMFV) scenarios. Cancellations may occur among the CP-violating contributions to the three measured EDMs arising from the 6 CP-violating phases in the MCPMFV scenario, leaving open the possibility of relatively large contributions to other CP-violating observables. The analytic expressions for the EDMs are implemented in an updated version of the code CPsuperH2.0.

Ellis, John; Lee, Jae Sik; Pilaftsis, Apostolos

2008-10-01

118

Electric dipole polarizability and the neutral skin  

SciTech Connect

The recent high-resolution measurement of the electric dipole (E1) polarizability {alpha}{sub D} in {sup 208}Pb [A. Tamii et al. Phys. Rev. Lett. 107 062502 (2011)] provides a unique constraint on the neutron-skin thickness of this nucleus. The neutron-skin thickness r{sub skin} of {sup 208}Pb 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 {alpha}{sub D} and r{sub skin}, we carry out systematic calculations for {sup 208}Pb, {sup 132}Sn, and {sup 48}Ca 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 {alpha}{sub D} and r{sub skin}, 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 r{sub skin} and {alpha}{sub D} for the nuclei under consideration. We conclude that precise measurements of r{sub skin} in both {sup 48}Ca and {sup 208}Pb - combined with the recent measurement of {alpha}{sub D} - should significantly constrain the isovector sector of the nuclear energy density functional.

Piechaczek, A. [Louisiana State University; Nazarewicz, Witold [ORNL; Reinhard, P.-G. [Universitat Erlangen, Germany; Agrawal, Bijay K [ORNL; Colo, Gianluca [ORNL; Paar, Nils [ORNL; Roca-Maza, X [IFGA, University of Milan and INFN, Milano, Italy; Vretenar, Dario [ORNL

2012-01-01

119

Electric dipole moment of the ? meson  

NASA Astrophysics Data System (ADS)

At a hadronic scale the effect of CP-violating interactions that typically appear in extensions of the Standard Model may be described by an effective Lagrangian, in which the operators are expressed in terms of lepton and partonic gluon and quark fields and ordered by their mass dimension, k?4. Using a global-symmetry-preserving truncation of QCD Dyson-Schwinger equations, we compute the ?-meson's electric dipole moment (EDM), d?, as generated by the leading dimension-four and dimension-five CP-violating operators and an example of a dimension-six four-quark operator. The two dimension-five operators, i.e., the quark EDM and quark chromo-EDM, produce contributions to d? whose coefficients are of the same sign and within a factor of 2 in magnitude. Moreover, should a suppression mechanism be verified for the ? term in any beyond-Standard-Model theory, the contribution from a four-quark operator can match the quark EDM and quark chromo-EDM in importance. This study serves as a prototype for the more challenging task of computing the neutron's EDM.

Pitschmann, Mario; Seng, Chien-Yeah; Ramsey-Musolf, Michael J.; Roberts, Craig D.; Schmidt, Sebastian M.; Wilson, David J.

2013-01-01

120

Magnetic dipole transitions in superdeformed nuclei  

SciTech Connect

Magnetic dipole transition matrix elements in superdeformed nuclei are calculated based on an axially symmetrically deformed Nilsson model. Several levels become the candidates to be assigned for the experimental evidence of the superdeformed band in {sup 193}Hg and {sup 193}Tl. Although the intrinsic {ital g}{sub {ital K}} factors for some levels show slower convergence to the asymptotic limit values, their wave functions show a good revival of {ital L}{minus}{ital S} coupling scheme at superdeformation. Comparing the experimental data with the renormalized {ital g}{sub {ital K}}{sup {prime}}, we find the pseudospin picture is not suitable for the superdeformed band. {copyright} {ital 1996 The American Physical Society.}

Sugawara-Tanabe, K.; Arima, A.; Yoshida, N. [Otsuma Womens University, Tama, Tokyo 206 (Japan)]|[The Institute of Physical and Chemical Research, Wako, Saitama 351-01 (Japan)]|[Faculty of Informatics, Kansai University, Takatsuki, Osaka 569 (Japan)

1996-01-01

121

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

122

Measurement of AC loss and magnetic field during ramps in the LHC model dipoles  

Microsoft Academic Search

We describe the systems for AC loss and magnetic field measurements developed for the LHC superconducting magnets. AC loss measurements are performed using an electric method, while field measurements are performed using either fixed pick-ups or rotating coils. We present results obtained on 1-m long model dipoles, and compare the results of the different methods in terms of average interstrand

Z. Ang; I. Bejar; L. Bottura; D. Richter; M. Sheahan; L. Walckiers; R. Wolf

1999-01-01

123

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

SciTech Connect

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 5x10{sup -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.

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. [Physics Department, Amherst College, Amherst, Massachusetts 01002 (United States); Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2005-12-16

124

Effects of dipole magnet inhomogeneities on the beam ellipsoid  

SciTech Connect

The RAYTRACE computer code has been modified to accept magnetic fields measured in the median plane of a dipole magnet. This modification allows one to study the effects of a non-ideal dipole magnet on the beam ellipsoid (as defined by the TRANSPORT code manual). The effects on the beam ellipsoid are due to: field inhomogeneities in the interior region of the dipole, and discrepancies from design conditions of the magnetic field values in the fringe field region. The results of the RAYTRACE code calculations based on experimentally measured fields will be compared with the results derived using both an ideal (no inhomogeneities) dipole with SCOFF boundaries and an ideal dipole with perfect (according to design) fringe fields.

Tsoupas, N.; Colman, J.; Levine, M.; McKenzie-Wilson, R.; Ward, T.; Grand, P.

1986-01-01

125

QED vacuum fluctuations and induced electric dipole moment of the neutron  

SciTech Connect

Quantum fluctuations in the QED vacuum generate nonlinear effects, such as peculiar induced electromagnetic fields. In particular, we show here that an electrically neutral particle, possessing a magnetic dipole moment, develops an induced electric dipole-type moment with unusual angular dependence, when immersed in a quasistatic, constant external electric field. The calculation of this effect is done in the framework of the Euler-Heisenberg effective QED Lagrangian, corresponding to the weak field asymptotic expansion of the effective action to one-loop order. It is argued that the neutron might be a good candidate to probe this signal of nonlinearity in QED.

Dominguez, C. A. [Centre for Theoretical Physics and Astrophysics, University of Cape Town, Rondebosch 7700 (South Africa); Department of Physics, Stellenbosch University, Stellenbosch 7600 (South Africa); Falomir, H. [Instituto de Fisica La Plata-Consejo Nacional de Ciencia y Tecnica, Universidad Nacional de La Plata (Argentina); Ipinza, M.; Loewe, M. [Facultad de Fisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Kohler, S. [Department of Physics, Stellenbosch University, Stellenbosch 7600 (South Africa); Rojas, J. C. [Departamento de Fisica, Universidad Catolica del Norte, Casilla 1280, Antofagasta (Chile)

2009-08-01

126

Development of Cellular Magnetic Dipoles in Magnetotactic Bacteria  

PubMed Central

Magnetotactic bacteria benefit from their ability to form cellular magnetic dipoles by assembling stable single-domain ferromagnetic particles in chains as a means to navigate along Earth's magnetic field lines on their way to favorable habitats. We studied the assembly of nanosized membrane-encapsulated magnetite particles (magnetosomes) by ferromagnetic resonance spectroscopy using Magnetospirillum gryphiswaldense cultured in a time-resolved experimental setting. The spectroscopic data show that 1), magnetic particle growth is not synchronized; 2), the increase in particle numbers is insufficient to build up cellular magnetic dipoles; and 3), dipoles of assembled magnetosome blocks occur when the first magnetite particles reach a stable single-domain state. These stable single-domain particles can act as magnetic docks to stabilize the remaining and/or newly nucleated superparamagnetic particles in their adjacencies. We postulate that docking is a key mechanism for building the functional cellular magnetic dipole, which in turn is required for magnetotaxis in bacteria.

Faivre, Damien; Fischer, Anna; Garcia-Rubio, Ines; Mastrogiacomo, Giovanni; Gehring, Andreas U.

2010-01-01

127

Modeling magnetic nanoparticle dipole-dipole interactions inside living cells  

NASA Astrophysics Data System (ADS)

Biomedical applications based on superparamagnetic nanoparticles injected in vivo may be affected by the cellular uptake of these nanoparticles. Living cells indeed capture and internalize nanoparticles, concentrating them into intracellular vesicles called lysosomes. As a consequence, nanoparticles interact magnetically with each other, modifying their magnetic properties. The effects of cellular uptake can be observed on the temperature dependence of zero-field cooled (ZFC) magnetization, which is known to be sensitive to magnetic interactions. In this paper, a theoretical model is proposed to account for weak magnetic interactions between nanoparticles aggregated into spherical compartments. This model suggests a new interpretation of the maximum of the ZFC curve, uncorrelated with the nanoparticle relaxation time but with the extent of interaction effects. It focuses on the local field felt by each nanoparticle, which is the sum of the applied magnetic field and the field created by all the other nanoparticles. For the considered organization of nanoparticles, only the field created by touching neighbors has to be taken into account, setting up the local nanoparticle volume fraction as the unique parameter of the model. This parameter relates the global magnetization measurements to the local distribution of nanoparticles in cells and tissues or in other complex media with aggregated organization.

Lévy, Michael; Gazeau, Florence; Bacri, Jean-Claude; Wilhelm, Claire; Devaud, Martin

2011-08-01

128

Calculation of the magnetic field due to a bioelectric current dipole in an ellipsoid  

Microsoft Academic Search

The bioelectric current dipole model is important both theoretically and computationally in the study of electrical activity\\u000a in the brain and stomach due to the resemblance of the shape of these two organs to an ellipsoid. To calculate the magnetic\\u000a field B due to a dipole in an ellipsoid, one must evaluate truncated series expansions involving ellipsoidal harmonics $$\\u000a\\\\mathbb{E}_n^m

Andrei Irimia

2008-01-01

129

Measuring the Electron Electric Dipole Moment Using Ytterbium Fluoride Molecules  

NASA Astrophysics Data System (ADS)

It is well known that the existence of an electron electric dipole moment (eEDM) would violate time reversal symmetry. The Standard Model predicts an eEDM less than 10^{-38}e.cm, however many popular extensions predict values in the range 10^{-29}-10^{-24}e.cm. Our experiment currently has the potential to measure eEDMs down to approximately 10^{-29}e.cm, making it a precise probe for T-violation and physics beyond the Standard Model. We measure the eEDM by performing a type of separated oscillating field interferometry on a pulsed beam of YbF. The molecules are prepared such that the molecular spin is oriented perpendicular to an applied strong (10kV/cm) electric field. The spin is then allowed to precess about the electric field axis over a 0.5ms interaction period. We measure this angle of rotation, which is directly proportional to the eEDM. In order to measure the eEDM precisely and without error we use a complex switching technique wherein certain parameters, including the applied electric and magnetic fields, are reversed between individual molecular pulses. I will present our current technique and our most recent world leading result.

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

2013-06-01

130

Dipole-quadrupole dynamics during magnetic field reversals  

SciTech Connect

The shape and the dynamics of reversals of the magnetic field in a turbulent dynamo experiment are investigated. We report the evolution of the dipolar and the quadrupolar parts of the magnetic field in the VKS experiment, and show that the experimental results are in good agreement with the predictions of a recent model of reversals: when the dipole reverses, part of the magnetic energy is transferred to the quadrupole, reversals begin with a slow decay of the dipole and are followed by a fast recovery, together with an overshoot of the dipole. Random reversals are observed at the borderline between stationary and oscillatory dynamos.

Gissinger, Christophe [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States)

2010-11-15

131

Space propulsion by fusion in a magnetic dipole  

Microsoft Academic Search

In this paper, the unique advantages of fusion rocket propulsion systems for distant missions are explored using the magnetic dipole configuration as an example. The dipole is found to have features well suited to space applications. Parameters are presented for a system producing a specific power of 1 kW\\/kg, capable of interplanetary flights to Mars in 90 days and to

E. Teller; A. J. Glass; A. Hasegawa; J. F. Santarius

1992-01-01

132

Space propulsion by fusion in a magnetic dipole  

Microsoft Academic Search

The unique advantages of fusion rocket propulsion systems for distant missions are explored using the magnetic dipole configurations as an example. The dipole is found to have features well suited to space applications. Parameters are presented for a system producing a specific power of kW\\/kg, capable of interplanetary flights to Mars in 90 days and to Jupiter in a year,

E. Teller; A. J. Glass; T. K. Fowler; A. Hasegawa; J. F. Santarius

1991-01-01

133

Laboratory model studies of satellite-borne electric dipole antennas on KROT magnetoplasma device  

Microsoft Academic Search

The scale modeling of satellite borne antenna systems is performed in a large laboratory mag-netoplasma. The experiments are carried out on KROT device (IAP RAS, Nizhny Novgorod); influence of magnetized plasma on impedance and radiation characteristics of electric dipole antennas is studied. Experimental parameters correspond to the operation of 10-100 m length antennas in topside ionosphere and plasmasphere. The dimensions

Mikhail Gushchin; Natalia Aidakina; Ilya Zudin; Sergei Korobkov; Alexander Kostrov; Askold Strikovsky

2010-01-01

134

Far field radiation from an arbitrarily oriented Hertzian dipole in an unbounded electrically gyrotropic medium  

Microsoft Academic Search

The general solution to the problem of far field radiation from an arbitrarily oriented Hertzian dipole in an electrically gyrotropic medium such as magnetically biased cold plasma, is found using the dyadic Green's function for the gyrotropic medium which is expressed as a sum of two single dyads. The numerical results are given in different frequency bands using Clemmow-Mually-Allis (CMA)

Abdullah Eroglu; J. K. Lee

2005-01-01

135

Solid-state systems for the electron electric dipole moment and other fundamental measurements  

Microsoft Academic Search

In 1968, Shapiro published the suggestion that one could search for an electron dipole moment (EDM) by applying a strong electric field to a substance that has an unpaired electron spin; at low temperature, the EDM interaction would lead to a net sample magnetization that can be detected with a superconducting quantum interference device (SQUID) magnetometer. One experimental EDM search

S. K. Lamoreaux

2002-01-01

136

NUCLEAR MAGNETIC DIPOLE MOMENT OF Ca⁴¹  

Microsoft Academic Search

The nuclear magnetic dipole spin resonance of Ca⁴¹ in a saturated ; Ca(NOâ)â aqueous solution was observed. A description is given of ; the experimental equipment and procedure. The amplitude of the Ca⁴¹ ; nuclear induction signal indicates a spin quantum number of 7\\/2. The corrected ; nuclear magnetic dipole moment is found to be -1.5946 nm. Various other ;

E. Brun; J. J. Kraushaar; W. L. Pierce; Wm. J. Veigele

1962-01-01

137

Need for remeasurements of nuclear magnetic dipole moments  

Microsoft Academic Search

The need for a reassessment of nuclear magnetic dipole moments is prompted by recent experiments on the ground-state hyperfine structure in highly charged hydrogenlike systems which are sufficiently sensitive to probe QED effects. This work gives an overview of the magnetic dipole moments for the nuclei of interest, i.e., 165Ho, 185,187Re, 203,205Tl, 207Pb, and 209Bi. It is found that the

Martin G. Gustavsson; Ann-Marie Mårtensson-Pendrill

1998-01-01

138

Electric quadrupole and magnetic dipole interactions at 181Ta impurity in Zr2Ni7 intermetallic compound: Experiment and first-principles calculations  

NASA Astrophysics Data System (ADS)

Electric quadrupole interactions at 181Ta impurity in the intermetallic compound Zr2Ni7 have been studied by perturbed angular correlation technique. It has been found that there are two electric field gradients (EFG) at the 181Ta site due to two different crystalline configurations in Zr2Ni7, while contradictory results were reported from previous investigations. The values of EFG at room temperature have been found to be Vzz=7.9×1017 V/cm2 and 7.1×1017 V/cm2 corresponding to present experimental values of quadrupole frequencies and asymmetry parameters for the two sites: ?Q1=70.7(1) Mrad/s, ?=0.28(1), ?=0.8(2)% (site fraction 84%) and ?Q2=63(1) Mrad/s, ?=0.35(5), ?˜0 (site fraction 9%). Electric field gradients and asymmetry parameters have been computed from the complementary first-principles density functional theory (DFT) to compare with present experimental results. Our calculated values of EFG are found to be in close agreement with the experimental results. No magnetic interactions in Zr2Ni7 have been observed at 298 and 77 K which implies that there is no ferromagnetic ordering in this material down to 77 K. This observation is corroborated by theoretical calculations, wherein no magnetic moment or hyperfine field is found at any atomic site.

Dey, C. C.; Srivastava, S. K.

2013-10-01

139

Extremely small domain in the lattice of magnetic dipoles  

NASA Astrophysics Data System (ADS)

Lattices of magnetic dipoles with 1-4 rows are investigated. Numerical analysis reveals the smallest stationary domains formed in the lattices, necessary conditions for the formation and destruction of such domains are obtained, and the change in the magnetic moment of the lattices during domain formation is considered. It is shown that the action of an external field on one of the dipoles forming a domain is sufficient for its breaking. The lattices in which the orientational phase transition appears upon perturbation of several dipoles and propagates over the entire system are revealed.

Shutyi, A. M.

2013-07-01

140

A superconducting dipole magnet for the UTSI MHD facility  

Microsoft Academic Search

The Argonne National Laboratory is designing and will build a large superconducting dipole magnet system for use in the Coal Fired Flow MHD Research Facility at the University of Tennessee Space Institute (UTSI). Presented in detail are the conceptual design of the magnet geometry, conductor design, cryostability evaluation, magnetic pressure computation, structural design, cryostat design, and the cryogenics system design.

S.-T. Wang; R. Niemann; L. Turner; L. Genens; W. Pelczarski; J. Gonczy; J. Hoffmann; Y.-C. Huang; N. Modjeski; E. Kraft

1979-01-01

141

Superconducting dipole magnet for the UTSI MHD facility  

Microsoft Academic Search

The Argonne National Laboratory is designing and will build a large superconducting dipole magnet system for use in the Coal Fired Flow MHD Research Facility at the University of Tennessee Space Institute (UTSI). Presented in detail are the conceptual design of the magnet geometry, conductor design, cryostability evaluation, magnetic pressure computation, structural design, cryostat design, and the cryogenics system design.

S. T. Wang; R. C. Niemann; L. R. Turner; L. Genens; W. Pelczarski; J. Gonczy; J. Hoffman; Y. C. Huang; N. Modjeski; E. Kraft

1978-01-01

142

Superconducting Super Collider 5T dipole magnet cryogenic design  

Microsoft Academic Search

Proposed colliding beam particle accelerators for high energy physics research will employ superconducting accelerator rings. The rings' superconducting magnet systems must provide the required magnetic function, have low refrigeration load, operate with very high reliability and be manufacturable at a low cost. The cryogenic aspects of a conceptual design for a 5T field, 5cm aperture, 12m long superconducting dipole magnet

R. C. Niemann; J. A. Carson; H. T. Edwards; N. Engler; J. D. Gonczy; R. W. Hanft; R. A. Lundy; P. M. Mantsch; A. D. McInturff; T. H. Nicol; R. J. Powers; R. Remsbottom; C. Rode; E. Schmidt; A. Szymulanski

1985-01-01

143

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

144

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

145

Regular and chaotic orbits near a massive magnetic dipole  

NASA Astrophysics Data System (ADS)

Within the framework of Bonnor's exact solution describing a massive magnetic dipole, we study the motion of neutral and electrically charged test particles. In dependence on the Bonnor spacetime parameters, we determine regions enabling the existence of stable circular orbits confined to the equatorial plane and of those levitating above the equatorial plane. Constructing Poincaré surfaces of section and recurrence plots, we also investigate the dynamics of particles moving along general off-equatorial trajectories bound in effective potential wells forming around the stable circular orbits. We demonstrate that the motion in the Bonnor spacetime is not integrable. This extends previous investigations of generalized Störmer's problem into the realm of exact solutions of Einstein-Maxwell equations, where the gravitational and electromagnetic effects play a comparable role on the particle motion.

Ková?, Ji?í; Kopá?ek, Ond?ej; Karas, Vladimír; Kojima, Yasufumi

2013-01-01

146

MIT Physics 8.02: Electrostatics - Creation of an Electric Dipole  

NSDL National Science Digital Library

This is an animation depicting the electric dipole field that is created when two opposite charges of equal magnitude are pulled apart. The item may be viewed as a video or in stepped motion. This item is part of a larger collection of visualizations developed by the MIT TEAL/Studio Physics Project to support an introductory course in electricity and magnetism. Lecture notes, labs, and presentations are also available as part of the MIT Open Courseware Repository: MIT Open Courseware: Electricity and Magnetism

Belcher, John

2010-04-12

147

Properties of the superconductor in accelerator dipole magnets  

NASA Astrophysics Data System (ADS)

Several aspects of the application of superconductors to high field dipole magnets for particle accelerators are discussed. The attention is focused on the 10 tesla (1 m model) magnet that is envisaged for the future Large Hadron Collider (LHC) accelerator. The basic motivation behind the study is the intention of employing superconductors to their utmost performance. An overview of practical supercomputers, their applications and their impact on high field dipole magnets used for particle accelerators, is presented. The LHC reference design for the dipole magnets is outlined. Several models were used to study the influence of a number of factors in the shape and in particular, the deviation from the shape that is due to the flux flow state. For the investigated extrinsic and intrinsic factors, a classification can be made with respect to the effect on the shape of the characteristic of a multifilamentary wire. The optimization of the coil structure for high field dipole magnets, with respect to the field quality is described. An analytical model for solid and hollow filaments, to calculate the effect of filament magnetization in the quality of the dipole field, is presented.

Teravest, Derk

148

Multiple Magnetic Dipole Modeling Coupled with a Genetic Algorithm  

NASA Astrophysics Data System (ADS)

Magnetic field measurements of scientific spacecraft can be modelled successfully with the multiple magnetic dipole method. The existing GANEW software [1] uses a modified Gauss-Newton algorithm to find good magnetic dipole models. However, this deterministic approach relies on suitable guesses of the initial parameters which require a lot of expertise and time-consuming interaction of the user. Here, the use of probabilistic methods employing genetic algorithms is put forward. Stochastic methods like these are well- suited for providing good initial starting points for GANEW. Furthermore a computer software is reported upon that was successfully tested and used for a Cluster II satellite.

Lientschnig, G.

2012-05-01

149

AC losses in the SSC high energy booster dipole magnets  

Microsoft Academic Search

The baseline design for the SSC (Superconducting Super Collider) high energy booster (HEB) has dipole bending magnets with a 50-mm aperture. An analysis of the cryogenic heat load due to AC losses generated in the HEB ramp cycle is reported for this magnet. Included in this analysis are losses from superconductor hysteresis, yoke hysteresis, strand eddy currents, and cable eddy

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

1992-01-01

150

Kick Velocity Induced by Magnetic Dipole and Quadrupole Radiation  

Microsoft Academic Search

We examine the recoil velocity induced by the superposition of magnetic dipole and quadrupole radiation from a pulsar\\/magnetar born with rapid rotation. The resultant velocity depends on not the magnitude, but rather the ratio of the two moments and their geometrical configuration. The model does not necessarily lead to high spatial velocity for a magnetar with a strong magnetic field,

Yasufumi Kojima; Yugo E. Kato

2011-01-01

151

Construction experiences with SSC collider dipole magnets at Fermilab  

Microsoft Academic Search

Full length and short model SSC (Superconducting Super Collider) 50 mm bore dipoles are being built and tested at Fermilab. The mechanical design of these magnets has been determined from experience with the construction of previous superconducting magnets. Construction experience includes coil fabrication, ground insulation, instrumentation, collaring, and yoke assembly. Fabrication techniques are explained, and construction problems and their solutions

R. C. Bossert; J. S. Brandt; J. A. Carson; K. Coulter; S. Delchamps; K. Ewald; H. Fulton; I. Gonczy; W. Koska; M. J. Lamm; J. B. Strait; M. Wake; M. Gordon; N. Hassan; R. Sims; M. Winters

1992-01-01

152

Second generation superconducting super collider dipole magnet cryostat design  

SciTech Connect

The SSC Magnet Development Program is developing accelerator dipole magnets in successive iterations. The initial iteration is complete with six full length model magnets and a thermal model having been built and tested. This initial experience along with the evolving SSC Magnet System Requirements have resulted in the second generation magnet cryostat design. It is this configuration that will be employed for the near term ongoing magnetic, thermal, string and accelerated life testing and will be the design considered for Phase I; i.e., Technology Orientation, of the SSC Magnet Industrialization Program. 5 refs., 7 figs., 1 tab.

Niemann, R.C.; Bossert, R.C.; Carson, J.A.; Engler, N.H.; Gonczy, J.D.; Larson, E.T.; Nicol, T.H.; Ohmori, T.

1988-12-01

153

Magnetic Dipole in a Stationary Plasma.  

National Technical Information Service (NTIS)

The determination of the magnetopause or free boundary of a plasma-free point dipole immersed in a field-free, stationary plasma is treated using a moment technique first introduced by Midgley and Davis. Their results are extended in two ways. First, usin...

P. F. Fougere

1970-01-01

154

New search for the neutron electric dipole moment  

SciTech Connect

We report on a new experiment to search for the neutron electric dipole moment which has the potential ta lower the current limit by a factor of 50 to 100. A unique approach to this measurement is described including the results of recent measurements at LANSCE of the mass diffusion coefficient for 3He in superfluid 4He.

Barnes, Peter D.

2002-01-01

155

Image theory for electric dipoles above a conducting anisotropic earth  

Microsoft Academic Search

New image representations for vertical electric dipoles (VED) above an imperfectly conducting and axially anisotropic earth are developed. These include multidiscrete images at different depths below the air-earth interface and multipole image sources. It is shown that, in contrast with the available image representations in the literature, the developed ones predict the correct behavior of the fields in the far

S. F. Mahmoud

1984-01-01

156

Linear time-dependent electric dipole properties of argon  

Microsoft Academic Search

This paper presents results of calculations of the Hartree-Fock first-order frequency-dependent properties of argon. Numerical results are given for the linear polarizability, refractive index, Verdet coefficients, and first electric dipole transition frequency. In addition, Van der Waal's coefficients between pairs of Hartree-Fock rare-gas atoms are presented.

V. G. Kaveeshwar; R. Klingbeil; R. P. Hurst

1976-01-01

157

Enhancement of the electron electric dipole moment in gadolinium garnets  

NASA Astrophysics Data System (ADS)

Effects caused by the electron electric dipole moment (EDM) in gadolinium garnets are considered. Experimental studies of these effects could improve the current upper limit on the electron EDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculations of observable effects in gadolinium gallium garnet and gadolinium iron garnet. Our calculation accounts for both direct and exchange diagrams.

Mukhamedjanov, T. N.; Dzuba, V. A.; Sushkov, O. P.

2003-10-01

158

Electric Dipole Echoes and Noise-Induced Decoherence  

SciTech Connect

The generation of echoes in the electric dipole moment of a Rydberg wavepacket precessing in an external electric field by reversal of the field is described. When the wavepacket experiences reversible dephasing, large echoes are observed pointing to strong refocusing of the wavepacket. The presence of irreversible dephasing leads to a reduction in the size of the echoes. The effectof irreversible dynamics on echoes is investigated using artifically synthesized noise. Methods to determine the decoherence rate are discussed.

Mestayer, J. J. [Rice University; Zhao, W. [Rice University; Lancaster, J. C. [Rice University; Dunning, F. B. [Rice University; Yoshida, S. [Vienna University of Technology, Austria; Reinhold, Carlos O [ORNL; Burgdorfer, J. [Vienna University of Technology, Austria

2007-01-01

159

An alternate method for designing dipole magnet ends  

SciTech Connect

Small bore superconducting dipole magnets, such as those for the SSC, often have problems in the ends. These problems can often be alleviated by spreading out the end windings so that the conductor sees less deformation. This paper presents a new procedure for designing dipole magnet ends which can be applied to magnets with either cylindrical or conical bulged ends to have integrated field multipoles which meet the constraints imposed by the SSC lattice. The method described here permits one to couple existing multiparameter optimization routines (i.e., MINUIT with suitable independent parameter constraints) with a computer code DIPEND, which describes the multiples, so that one can meet any reasonable objective (i.e., minimizing integrated sextupole and decapole). This paper will describe how the computer method was used to analyze the bulged conical ends for an SSC dipole. 6 refs, 6 figs, 2 tabs.

Pope, W.L.; Green, M.A.; Peters, C.; Caspi, S.; Taylor, C.E.

1988-08-01

160

Superconducting super collider 5T dipole magnet cryogenic design  

SciTech Connect

Proposed colliding beam particle accelerators for high energy physics research will employ superconducting accelerator rings. The rings' superconducting magnet systems must provide the required magnetic function, have low refrigeration load, operate with very high reliability and be manufacturable at a low cost. The cryogenic aspects of a conceptual design for a 5T field, 5cm aperture, 12m long superconducting dipole magnet suitable for a 20 TeV proton-proton collider are presented.

Niemann, R.C.; Carson, J.A.; Edwards, H.T.; Engler, H.N.; Gonczy, J.D.; Hanft, R.W.; Lundy, R.A.; Mantsch, P.M.; McInturff, A.D.; Nicol, T.H.; Powers, R.J.

1985-03-01

161

13B Nuclear Magnetic Dipole Moment  

Microsoft Academic Search

Polarized 13B nuclei have been produced through the 11B(t,p)13B reaction using the 3.5-MeV Van de Graaff accelerator at Brookhaven National Laboratory. The recoiling nuclei were stopped in Au, Pd, and Pt foils, and the effective dipole moments of 13B in these metals were measured by a resonant depolarization technique. From earlier measurements of the spin-lattice relaxation times of 12B in

R. L. Williams; L. Madansky

1971-01-01

162

SKEW QUADRUPOLES IN RHIC DIPOLE MAGNETS AT HIGH FIELDS.  

SciTech Connect

In the RHIC arc dipoles, the center of the cold mass lies above the center of the cryostat. At the maximum design field, the magnetic flux lines leak through the yoke to the asymmetrically located cryostat, which provides an additional return path. This introduces a systematic top-bottom asymmetry leading to a skew quadrupole term at high fields. A similar asymmetry is also created by any difference in weights of the upper and the lower yoke halves. Data from measurements of several RHIC dipoles are presented to study this effect. In the current production series of the RDIC dipoles, an attempt is made to compensate the effect of the cryostat by an asymmetry in the iron yoke. Seven dipoles with this type of yoke have been cold tested, and show a reduced saturation in the skew quadrupole term, as expected.

JAIN, A.; GUPTA, P.; THOMPSON, P.; WANDERER, P.

1995-06-11

163

Quantum-mechanical description of spin-1 particles with electric dipole moments  

NASA Astrophysics Data System (ADS)

The Proca-Corben-Schwinger equations for a spin-1 particle with an anomalous magnetic moment are added by a term describing an electric dipole moment, then they are reduced to a Hamiltonian form, and finally they are brought to the Foldy-Wouthuysen representation. Relativistic equations of motion are derived. The needed agreement between quantum-mechanical and classical relativistic equations of motion is proved. The scalar and tensor electric and magnetic polarizabilities of pointlike spin-1 particles (W bosons) are calculated for the first time.

Silenko, Alexander J.

2013-04-01

164

Magnetic dipole moments in single and coupled split-ring resonators  

Microsoft Academic Search

We examine the role of magnetic dipoles in single and coupled pairs of metallic split-ring resonators by numerically computing their magnitude and examining their relative contributions to the scattering cross section. We demonstrate that magnetic dipoles can strongly influence the scattering cross section along particular directions. It is also found that the magnetic dipole parallel to the incident magnetic field

Yong Zeng; Colm Dineen; Jerome V. Moloney

2010-01-01

165

Magnetic Dipole Moment from a One?Kiloton Underground Nuclear Explosion in a Cavity  

Microsoft Academic Search

This paper reports the results of numerical modeling of the magnetic dipole moment produced by displacement of the Earth's magnetic field in a one-kiloton underground nuclear explosion in a cavity. It is shown that with increase in cavity size, the magnetic dipole moment increases, reaching 107 A · m2, which is approximately 200 times the magnetic dipole moment from a

N. G. Karlykhanov; A. A. Kondrat'ev; V. N. Nogin

2004-01-01

166

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.

167

Stress Management and Capacitive Stress Transducers Used in Dipole Magnets  

NASA Astrophysics Data System (ADS)

Research in accelerator dipole magnet technology is aimed first and foremost to produce as high a magnetic field as possible. However, stresses in the superconducting coil packages from Lorentz forces limit the maximum field. Future dipole magnets are being designed, built, and tested by the Accelerator Research Lab at Texas A&M University which incorporate unique stress management techniques. Within these magnets, custom capacitive pressure transducers are being developed to monitor the Lorentz forces within the coil package. A brief introduction to stress management techniques used in future TAMU magnets will be given, along with the status of current and future research involving tooling and fabrication techniques used in the production of capacitive pressure transducers.

Benson, Christopher; McIntyre, Peter; McInturff, Al; Jaisle, Andrew; Holik, Trey

2009-10-01

168

A variable-field permanent-magnet dipole for accelerators  

SciTech Connect

A new concept for a variable-field permanent-magnet dipole has been developed and fabricated at Los Alamos. The application requires an extremely uniform dipole field in the magnet aperture and precision variability over a large operating range. An iron-core permanent- magnet design using a shunt that was specially shaped to vary the field in a precise and reproducible fashion with shunt position. The key to this design is in the shape of the shunt. The field as a function of shunt position is very linear from 90% of the maximum field to 20% of the minimum field. The shaped shunt also results in a small maximum magnetic force attracting the shunt to the yoke allowing a simple mechanical design. Calculated and measured results agree well for the magnet.

Kraus, R.H. Jr.; Barlow, D.B.; Meyer, R.

1992-01-01

169

A variable-field permanent-magnet dipole for accelerators  

SciTech Connect

A new concept for a variable-field permanent-magnet dipole has been developed and fabricated at Los Alamos. The application requires an extremely uniform dipole field in the magnet aperture and precision variability over a large operating range. An iron-core permanent- magnet design using a shunt that was specially shaped to vary the field in a precise and reproducible fashion with shunt position. The key to this design is in the shape of the shunt. The field as a function of shunt position is very linear from 90% of the maximum field to 20% of the minimum field. The shaped shunt also results in a small maximum magnetic force attracting the shunt to the yoke allowing a simple mechanical design. Calculated and measured results agree well for the magnet.

Kraus, R.H. Jr.; Barlow, D.B.; Meyer, R.

1992-09-01

170

Communication: Magnetic dipole transitions in the OH A 2?+ ? X 2? system.  

PubMed

We report on the observation of magnetic dipole allowed transitions in the well-characterized A (2)?(+) - X (2)? band system of the OH radical. A Stark decelerator in combination with microwave Rabi spectroscopy is used to control the populations in selected hyperfine levels of both ?-doublet components of the X (2)?(3/2), v = 0, J = 3/2 ground state. Theoretical calculations presented in this Communication predict that the magnetic dipole transitions in the A (2)?(+), v = 1 ? X (2)?, v = 0 band are weaker than the electric dipole transitions by a factor of 2.58 × 10(3) only, i.e., much less than commonly believed. Our experimental data confirm this prediction. PMID:22979842

Kirste, Moritz; Wang, Xingan; Meijer, Gerard; Gubbels, Koos B; van der Avoird, Ad; Groenenboom, Gerrit C; van de Meerakker, Sebastiaan Y T

2012-09-14

171

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

NASA Astrophysics Data System (ADS)

We recently reported a new measurement of the electron's electric dipole moment using YbF molecules (Hudson et al 2011 Nature 473 493). 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 dipole moment of zero, so we provide upper bounds to its size at various confidence levels. Finally, we review the prospects for future improvements in the precision of the experiment.

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

2012-10-01

172

ULF\\/ELF magnetic fields generated at the sea surface by submerged magnetic dipoles  

Microsoft Academic Search

The complete expressions for the electromagnetic fields generated by buried harmonic dipole sources involve complex integrals that cannot ordinarily be solved in closed form. We present numerical solutions for the quasi-static magnetic fields at the sea surface due to magnetic dipoles submerged from 25 m to 200 m in an infinitely deep sea, for frequencies in the interval 0.1 Hz

A. C. Fraser-Smith; D. M. Bubenik

1976-01-01

173

Near-Field Magnetic Dipole Moment Analysis.  

National Technical Information Service (NTIS)

This paper describes the data analysis technique used for magnetic testing at the NASA Goddard Space Flight Center (GSFC). Excellent results have been obtained using this technique to convert a spacecraft s measured magnetic field data into its respective...

P. K. Harris

2003-01-01

174

Transient cooldown stresses in superconducting collider dipole magnet.  

National Technical Information Service (NTIS)

The three-dimensional thermal transient stress in a collider dipole magnet (CDM) is evaluated and examined. The cooldown rate is one of the factors that determines the availability of the Superconducting Super Collider ring, but it is limited by stress in...

K. K. Leung G. Snitchler

1992-01-01

175

Petrophysics of magnetic dipole fields in an anisotropic earth  

Microsoft Academic Search

Measurement-while-drilling (MWD) resistivity log data are often acquired in highly deviated or horizontal holes. The loop sensors are located on the drill collar and are approximated as magnetic dipoles. The conductivity of the earth in the vertical direction ?v and horizontal direction ?h are almost always different. When an MWD resistivity tool enters a new bed, the response is compared

2000-01-01

176

Weak magnetic dipole moments in two-Higgs-doublet models  

Microsoft Academic Search

We investigate the effects of the new scalars in a two-Higgs-doublet model on the weak magnetic dipole moments of the fermions at the Z peak. The proportionality of the Yukawa couplings to the fermion masses, and to tanbeta, makes such effects more important for the third family, and potentially relevant. For the tau lepton, the new diagrams are suppressed by

J. Bernabéu; D. Comelli; L. Lavoura; João P. Silva

1996-01-01

177

Weak magnetic dipole moments in two-Higgs-doublet models  

Microsoft Academic Search

We investigate the effects of the new scalars in a two-Higgs-doublet model on the weak magnetic dipole moments of the fermions at the {ital Z} peak. The proportionality of the Yukawa couplings to the fermion masses, and to tan, makes such effects more important for the third family, and potentially relevant. For the lepton, the new diagrams are suppressed by

J. Bernabeu; D. Comelli; L. Lavoura; Joao P. Silva

1996-01-01

178

Superconducting super collider second generation dipole magnet cryostat design  

Microsoft Academic Search

The Superconducting Super Collider, a planned colliding beam particle physics research facility, requires --10,000 superconducting devices for the control of high energy particle beams. The --7,500 collider ring superconducting dipole magnets require cryostats that are functional, cryogenically efficient, mass producible and cost effective. A second generation cryostat design has been developed utilizing the experiences gained during the construction, installation and

R. C. Niemann; R. C. Bossert; J. A. Carson; N. H. Engler; J. D. Gonczy; E. T. Larson; T. H. Nicol; T. Ohmori

1989-01-01

179

Magnetic field measurements of model SSC (Superconducting Super Collider) dipoles  

Microsoft Academic Search

To qualify for use in the Superconducting Super Collider, the 8000 or so 16 m long dipole magnets must pass a series of tests. One of these will be a set of warm measurements of field quality, which must be precise to about 0.001% of the 100 G field produced by 10 A, the maximum current the coils are allowed

W. V. Hassenzahl; W. S. Gilbert; M. I. Green; P. J. Barale

1986-01-01

180

SUPERCONDUCTING DIPOLE MAGNETS FOR THE LHC INSERTION REGIONS  

Microsoft Academic Search

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

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

2000-01-01

181

Magnetic dipole localization with a gradiometer: obtaining unique solutions  

Microsoft Academic Search

The five independent equations describing the field gradient tensor at a point for a static magnetic dipole source can be inverted to give the bearing vector to the source and the source moment vector divided by the fourth power of the range. The equations have four solutions, two of which are related in a non-trivial way, and two more that

W. M. Wynn

1997-01-01

182

Higgs-Higgsino-gaugino induced two loop electric dipole moments  

SciTech Connect

We compute the complete set of Higgs-mediated chargino-neutralino two-loop contributions to the electric dipole moments of the electron and neutron in the minimal supersymmetric standard model (MSSM). We study the dependence of these contributions on the parameters that govern CP-violation in the MSSM gauge-gaugino-Higgs-Higgsino sector. We find that contributions mediated by the exchange of WH{sup {+-}} and ZA{sup 0} pairs, where H{sup {+-}} and A{sup 0} are the charged and CP-odd Higgs scalars, respectively, are comparable to or dominate over those mediated by the exchange of neutral gauge bosons and CP-even Higgs scalars. We also emphasize that the result of this complete set of diagrams is essential for the full quantitative study of a number of phenomenological issues, such as electric dipole moment searches and their implications for electroweak baryogenesis.

Li Yingchuan [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Profumo, Stefano [Department of Physics and Santa Cruz Institute for Particle Physics, University of California, 1156 High Street, Santa Cruz, California 95064 (United States); Ramsey-Musolf, Michael [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125 (United States)

2008-10-01

183

Magnetic dipole moment of 127 Sb by NMR\\/ON  

Microsoft Academic Search

The technique of NMR on oriented nuclei has been applied to127Sb to measure the magnetic dipole moment of the127Sb ground state. Resonant destruction of gamma-ray anisotropy from127Sbg (Ip=7\\/2+) has been observed at 139.6(2) MHz forBapp=0.30(1) T andat 138.7(1) MHz forBapp=0.25(1) T. The deduced magnetic moment is |µ|=2.697(6) µN.

M. Booth; M. Lindroos; I. Oliveira; P L Richards; J. Rikovska; N. J. Stone; B. Fogelberg; M. Veskovic

1993-01-01

184

Core polarization corrections to magnetic dipole moments and transitions  

Microsoft Academic Search

Core polarization corrections to ground state magnetic dipole moments are calculated in first-order perturbation theory, with the use of Sussex matrix elements. These corrections are introduced in the particle-(hole-) core coupling model. It is shown that the need for effectivegs factors in the calculation of magnetic moments can be explained largely in terms of one-particle-one-hole polarization effects of the core.

G. Vanden Berghe; K. Heyde; M. Waroquier

1973-01-01

185

Magnetic dipole moment of the ?(1232) in chiral perturbation theory  

Microsoft Academic Search

.  The magnetic dipole moment of the ?(1232) is calculated in the framework of manifestly Lorentz-invariant baryon chiral perturbation\\u000a theory in combination with the extended on-mass-shell renormalization scheme. As in the case of the nucleon, at leading order\\u000a both isoscalar and isovector anomalous magnetic moments are given in terms of two low-energy constants. In contrast to the\\u000a nucleon case, at next-to-leading

C. Hacker; N. Wies; J. Gegelia; S. Scherer

2006-01-01

186

Primary measuring transducer for determining magnetic dipole moment  

Microsoft Academic Search

The features of a new primary transducer, designed to measure two components of the magnetic dipole moment vector, are considered.\\u000a The transducer has an extremely simple construction. Using it, one can eliminate relative errors of the displacement of this\\u000a vector, which reach 10–20%. The measurement equations and an original formula for calculating the magnetic flux are obtained.

V. A. Slaev; Yu. A. Urbanovich

1998-01-01

187

Magnetic dipole moments of the 147, 149 Gd ground states  

Microsoft Academic Search

Nuclear orientation measurements at low temperatures have been carried out on radioactive isotopes147, 149Gd in Fe and Gd. The initial-state orientation coefficients determined from the measured gamma-ray anisotropies yield the magnetic dipole moments of the147Gd and149Gd ground states to be 1.02(9) and 0.88(4), ?N, respectively. These values follow the systematics of the 7\\/2? state magnetic moments of the odd-A nuclei

T. I. Kracíková; S. Davaa; M. Finger

1987-01-01

188

Four-layer, two-inch bore, superconducting dipole magnet  

SciTech Connect

Superconductors provide the accelerator designer with a unique opportunity to construct machines that can achieve high particle energies and yet have low operating costs. This paper describes the design, fabrication and testing of a 4 layer, 50 mm bore superconducting dipole magnet, D-9A. The magnet reached short sample, 5.8 T at 4.4 K and 8.0 T and 1.8 K, with little training, and exhibited low losses and low ramp rate sensitivity.

Hassenzahl, W.V.; Peters, C.; Gilbert, W.; Taylor, C.; Meuser, R.

1982-11-01

189

Coil end design for the SSC collider dipole magnet  

Microsoft Academic Search

The authors describe the design of the coil end for the 50-mm-aperture SSC (Superconducting Super 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

J. S. Brandt; N. W. Bartlett; R. C. Bossert; J. A. Carson; J. J. Konc; G. C. Lee; J. M. Cook; S. Caspi; M. A. Gordon; F. Nobrega

1991-01-01

190

Construction experiences with SSC collider dipole magnets at Fermilab  

SciTech Connect

Full length and short model SSC 50 mm bore dipoles are being built and tested at Fermilab. Mechanical design of these magnets has been determined from experience involved in the construction of previous superconducting magnets. construction experience includes coil fabrication, ground insulation, instrumentation, collaring and yoke assembly. In this paper fabrication techniques are explained. Construction problems and their solutions are reviewed. Relationship of short to long model construction is discussed.

Bossert, R.C.; Brandt, J.S.; Carson, J.A.; Coulter, K.; Delchamps, S.; Ewald, K.; Fulton, H.; Gonczy, I.; Koska, W.; Lamm, M.J.; Srait, J.B.; Wake, M. (Fermi National Accelerator Lab., Batavia, IL (United States))

1992-01-01

191

Magnetic Fields of a Dipole in Special Volume Conductor Shapes  

Microsoft Academic Search

Expressions are presented for the magnetic fields produced by current dipoles in four basic volume conductor shapes. These shapes are the semi-infinite volume, the sphere, the prolate spheroid (egg-shape), and the oblate spheroid (discus-shape). The latter three shapes approximate the shape of the human head and can serve as a basis for understanding the measurements of the brain's magnetic fields.

B. Neil Cuffin; David Cohen

1977-01-01

192

CP violation beyond the MSSM: baryogenesis and electric dipole moments  

Microsoft Academic Search

We study electroweak baryogenesis and electric dipole moments in the presence of the two leading-order, non-renormalizable\\u000a operators in the Higgs sector of the MSSM. Significant qualitative and quantitative differences from MSSM baryogenesis arise\\u000a due to the presence of new CP-violating phases and to the relaxation of constraints on the supersymmetric spectrum (in particular,\\u000a both stops can be light). We find:

Kfir Blum; Cedric Delaunay; Marta Losada; Yosef Nir; Sean Tulin

2010-01-01

193

A cosmological lower bound on the neutron electric dipole moment  

Microsoft Academic Search

We argue that in a wide class of grand unified theories diagrams similar to those generating baryon number in the early universe also contribute to renormalization of the CP-violating theta parameter of QCD and hence to the neutron electric dipole moment dn. We then use the apparent baryon-to-photon ratio (nB\\/ngamma) >~ 1.3 × 10-10 to deduce an order-of-magnitude lower bound

John Ellis; Mary K. Gaillard; D. V. Nanopoulos; Serge Rudaz

1981-01-01

194

Rheometry Experiment of Electric Dipole Antennas Onboard GEOTAIL  

NASA Astrophysics Data System (ADS)

Two components of ac electric field are measured by two pairs of long dipole antennas onboard GEOTAIL spacecraft; the wire antenna (WANT) and the probe antenna (PANT). The frequency range is from dc to 800 kHz. To obtain accurate values of electric field components, we should evaluate an exact antenna effective length and an accurate antenna impedance of each dipole. The antenna impedance has been measured in situ, and the effective lengths have been so far assumed simply as 50 m, half of their tip-to-tip length of 100 m. However it is not easy to estimate actual effective length especially in the low frequency such as several hundreds Hz or lower. In this study, we conduct an experiment of rheometry. A 1/100 scale model of GEOTAIL and its wire antennas are immersed in a water tank with an applied uniform ac electric field. By actually receiving the ac field with the wire antenna attached to the GEOTAIL model, we evaluate various characteristics of the antenna, such as effective lengths, directivity patterns, and frequency responses. We will report the results of the experiment, and discuss the characteristics of the dipole antennas onboard GEOTAIL.

Imachi, T.; Yagitani, S.; Nagano, I.; Higashi, R.; Tsutsui, M.; Matsumoto, H.

2001-12-01

195

Magnetic or optical molasses loading for a Cs dipole trap  

NASA Astrophysics Data System (ADS)

We have studied the loading of a single-beam or a crossed dipole trap made by a Nd:YAG laser. The loading was performed from a magnetic trap or after a molasses phase with cesium atoms. Looking for high atomic density to perform a fast evaporation to reach the Bose-Einstein Condensation, we found that a crossed dipole trap with a waist of 30 ?m and a laser power P=10 W, loaded from a molasses, gives a good starting point to begin evaporation with 5 &|m~ 106 atoms loaded in 50 ms.

Stern, G.; Dimova, E.; Fioretti, A.; Comparat, D.; Pillet, P.

2007-03-01

196

Connecting Electricity and Magnetism  

NSDL National Science Digital Library

As discussed at the beginning of the book, there is an intimate connection between electricity and magnetism, which will be further addressed in this chapter as well. We'll end up with a scientific model for what magnetism is, what makes something a permanent magnet, and why magnets attract some metals and not others.

Robertson, William C.

2005-01-01

197

Elasticity of nuclear medium as a principal macrodynamical promoter of electric pygmy dipole resonance  

NASA Astrophysics Data System (ADS)

Motivated by arguments of the nuclear core-layer model formulated in [S.I. Bastrukov, J.A. Maruhn, Z. Phys. A 335 (1990) 139], the macroscopic excitation mechanism of the electric pygmy dipole resonance (PDR) is considered as owing its origin to perturbation-induced effective decomposition of a nucleus into two spherical domains undisturbed inner region treated as a static core and dynamical layer undergoing elastic shear vibrations. The elastic restoring force is central to the excitation mechanism under consideration and has the same physical meaning as in macroscopic model of nuclear giant resonances involving distortions of the Fermi-sphere providing unified description of isoscalar giant electric and magnetic resonances of multipole degree ??2 in terms of two fundamental vibrational modes in an elastic sphere, to wit, as spheroidal (electric) and torsional (magnetic) modes of shear elastic oscillations of the nodeless field of material displacements excited in the entire nucleus volume. In the present Letter focus is placed on the emergence of dipole overtone in the frequency spectrum of spheroidal elastic vibrations as Goldstone soft mode. To emphasis this feature of dipole resonant excitation imprinted in the core-layer model we regain spectral equation for the frequency of spheroidal elastic vibrations trapped in the finite-depth layer, derived in the above paper, but using canonical equation of an elastic continuous medium. The obtained analytic equations for the frequency of dipole vibrational state in question and its excitation strength lead to the following estimates for the PDR energy centroid E(E1)=[31±1]A MeV and the total excitation probability B(E1)=[1.85±0.05]10ZAe fm throughout the nuclear chart exhibiting fundamental character of this soft dipole mode of nuclear resonant response.

Bastrukov, S. I.; Molodtsova, I. V.; Podgainy, D. V.; Mi?icu, ?.; Chang, H.-K.

2008-06-01

198

Managing magnetic force applied to a magnetic device by a rotating dipole field  

NASA Astrophysics Data System (ADS)

We demonstrate that the attractive magnetic force acting on a rotating magnetic device (e.g., a magnetic microrobot), actuated using a rotating magnet dipole, can be converted into a lateral force by rotating the actuator dipole according to a specific open-loop trajectory. Results show rotating magnetic devices can be rolled and simultaneously pushed along a surface by the lateral force, resulting in significant increase in velocity. We also demonstrate that the lateral force magnitude can be sufficient to levitate the magnetic device. The results apply to rotating magnetic devices of any size provided inertia has a negligible contribution to its dynamics.

Mahoney, Arthur W.; Abbott, Jake J.

2011-09-01

199

Magnetic localisation of a current dipole implanted in dogs.  

PubMed

In order to evaluate the difficulty in localising a current dipole due to volume conductor current contributions to the magnetocardiogram, accuracy of depth localisation of a commercial coaxial pacemaker cable, used as a current dipole, was studied in two experimental situations: immersed in a prismatic container with NaCl solution and introduced into the lower oesophagus of dogs. Isofield contour maps were obtained by interpolation of the magnetic field measured over a plane and perpendicular to it with a third-order gradiometer coupled to a SQUID. The dipole can be accurately localised in the prismatic container. The observation of an isofield map that is symmetric about the maximum-minimum axis when the dogs are in the dorsal decubitus position with the dipole in the cephalocaudal direction implies that internal inhomogeneities in the dog's volume conductor produce no appreciable effect on the magnetic field. Nevertheless, a large distortion of the magnetic field lines is observed and can be explained by calculations using models that take into account the external boundary of the volume conductor. PMID:3823141

Costa Monteiro, E; Bruno, A C; Louro, S R; Costa Ribeiro, P; Fonseca Costa, A

1987-01-01

200

Theoretical analysis of the spin exchange and magnetic dipole-dipole interactions leading to the magnetic structure of Ni3TeO6.  

PubMed

The origin of the collinear antiferromagnetic magnetic structure of Ni(3)TeO(6) below 52 K was analyzed by calculating its spin exchanges on the basis of density functional calculations, and the cause for the parallelc-spin orientation found for this magnetic structure by calculating the spin-orbit coupling and magnetic dipole-dipole interaction energies. The calculated exchanges correctly predict the observed magnetic structure below 52 K, and lead practically to no spin frustration. The perpendicularc- and parallelc-spin orientations are predicted by the spin-orbit coupling and the magnetic dipole-dipole interactions, respectively. However, the magnetic dipole-dipole interactions are stronger than the spin-orbit coupling interactions, and hence are responsible for the spin orientation observed for Ni(3)TeO(6). PMID:20690764

Wu, Fang; Kan, Erjun; Tian, Chuan; Whangbo, Myung-Hwan

2010-08-16

201

Superconducting super collider second generation dipole magnet cryostat design  

SciTech Connect

The Superconducting Super Collider, a planned colliding beam particle physics research facility, requires --10,000 superconducting devices for the control of high energy particle beams. The --7,500 collider ring superconducting dipole magnets require cryostats that are functional, cryogenically efficient, mass producible and cost effective. A second generation cryostat design has been developed utilizing the experiences gained during the construction, installation and operation of several full length first generation dipole magnet models. The nature of the cryostat improvements is presented. Considered are the connections between the magnet cold mass and its supports, cryogenic supports, cold mass axial anchor, thermal shields, insulation, vacuum vessel and interconnections. The details of the improvements are enumerated and the abstracted results of available component and system evaluations are presented.

Niemann, R.C.; Bossert, R.C.; Carson, J.A.; Engler, N.H.; Gonczy, J.D.; Larson, E.T.; Nicol, T.H.; Ohmori, T.

1989-03-01

202

Superconducting super collider second generation dipole magnet cryostat design  

SciTech Connect

The Superconducting Super Collider, a planned colliding beam particle physics research facility, requires /approximately/10,000 superconducting devices for the control of high energy particle beams. The /approximately/7,500 collider ring superconducting dipole magnets require cryostats that are functional, cryogenically efficient, mass producible and cost effective. A second generation cryostat design has been developed utilizing the experiences gained during the construction, installation and operation of several full length first generation dipole magnet models. The nature of the cryostat improvements is presented. Considered are the connections between the magnet cold mass and its supports, cryogenic supports, cold mass axial anchor, thermal shields, insulation, vacuum vessel and interconnections. The details of the improvements are enumerated and the abstracted results of available component and system evaluations are presented. 8 refs., 11 figs.

Niemann, R.C.; Bossert, R.C.; Carson, J.A.; Engler, N.H.; Gonczy, J.D.; Larson, E.T.; Nicol, T.H.; Ohmori, T.

1988-12-01

203

A radiation hard dipole magnet coils using aluminum clad copper conductors  

SciTech Connect

A C-type septum dipole magnet is located 600 mm downstream of the primary target in an external beam line of the AGS. Conventional use of fiber glass/epoxy electrical insulation for the magnet coils results in their failure after a relatively short running period, therefore a radiation hard insulation system is required. This is accomplished by replacing the existing copper conductor with a copper conductor having a thin aluminum skin which is anodized to provide the electrical insulation. Since the copper supports a current density of 59 A/mm/sup 2/, no reduction in cross sectional area can be tolerated. Design considerations, manufacturing techniques, and operating experience of a prototype dipole is presented. 3 refs., 4 figs.

Leonhardt, W.J.

1989-01-01

204

Refrigeration options for the Advanced Light Source Superbend Dipole Magnets  

SciTech Connect

The 1.9 GeV Advance Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL) produces photons with a critical energy of about 3.1 kev at each of its thirty-six 1.3 T gradient bending magnets. It is proposed that at three locations around the ring the conventional gradient bending magnets be replaced with superconducting bending magnets with a maximum field of 5.6 T. At the point where the photons are extracted, their critical energy will be about 12 keV. In the beam lines where the SuperBend superconducting magnets are installed, the X ray brightness at 20 keV will be increased over two orders of magnitude. This report describes three different refrigeration options for cooling the three SuperBend dipoles. The cooling options include: (1) liquid helium and liquid nitrogen cryogen cooling using stored liquids, (2) a central helium refrigerator (capacity 70 to 100 W) cooling all of the SuperBend magnets, (3) a Gifford McMahon (GM) cryocooler on each of the dipoles. This paper describes the technical and economic reasons for selecting a small GM cryocooler as the method for cooling the SuperBend dipoles on the LBNL Advanced Light Source.

Green, M.A.; Hoyer, E.H.; Schlueter, R.D.; Taylor, C.E.; Zbasnik, J.; Wang, S.T.

1999-07-09

205

Bilayer crystals of charged magnetic dipoles: structure and phonon spectrum.  

PubMed

We study the structure and phonon spectrum of a two-dimensional bilayer system of classical charged dipoles oriented perpendicular to the plane of the layers for equal density in each layer. This system can be tuned through six different crystalline phases by changing the interlayer separation or the charge and/or dipole moment of the particle. The presence of the charge on the dipole particles is responsible for the nucleation of five staggered phases and a disordered phase which are not found in the magnetic dipole bilayer system. These extra phases are a consequence of the competition between the repulsive Coulomb and the attractive dipole interlayer interaction. We present the phase diagram and determine the order of the phase transitions. The phonon spectrum of the system was calculated within the harmonic approximation, and a nonmonotonic behavior of the phonon spectrum is found as a function of the effective strength of the interparticle interaction. The stability of the different phases is determined. PMID:23004758

Ramos, I R O; Ferreira, W P; Munarin, F F; Farias, G A; Peeters, F M

2012-05-24

206

Challenges and opportunities in the search for electric dipole moment (EDM) in ^225Ra atom  

NASA Astrophysics Data System (ADS)

The observation of a permanent electric dipole moment (EDM) in a non-degenerate system would indicate violation of time reversal symmetry. ^225Ra atom is a particularly attractive candidate for this search since it has a nuclear spin I=1/2 and has a significant nuclear octupole deformation. This property increases the Schiff moment of the nucleus and therefore enhances the atomic EDM. The half life (t1/2 =14.9 days) of ^225Ra is sufficiently long to perform EDM searches. Our group has already demonstrated the trapping of laser cooled Ra atoms in a magneto-optical trap (MOT) and transferring them to a far off resonant optical dipole trap (ODT). We will discuss our recent progress on manipulation of ultra cold Ra atoms in the ODT, efforts in improving our laser systems and generation of electric and magnetic fields required for the measurement.

Ranjan Kalita, Mukut; Bailey, Kevin; Dietrich, Matthew; Greene, John; Holt, Roy; Korsch, Wolfgang; Lu, Zheng-Tian; Mueller, Peter; O'Connor, Thomas; Parker, Richard; Sulai, Ibrahim; Singh, Jaideep

2011-10-01

207

A new experimental limit on the electric dipole moment of the electron  

SciTech Connect

We describe a search for the electric dipole moment d{sub e} of the electron, carried out with {sup 205}Tl atoms in the ground state. The experiment makes use of the separated-oscillating-field magnetic-resonance method, laser state selection, fluorescence detection, and two counter-propagating atomic beams. Very careful attention is paid to systematic effects. The result for the atomic electric dipole moment is d{sub a} = (1.6 {plus minus} 5.0) {times} 10{sup {minus}24} e cm. If we assume the theoretical ratio d{sub a}/d{sub e} = {minus}600, this yields d{sub e} = ({minus}2.7 {plus minus} 8.3) {times} 10{sup {minus}27} e cm. 17 refs., 7 figs., 1 tab.

Carlberg, C.; Gould, H. (Lawrence Berkeley Lab., CA (USA)); Abdullah, K.; Commins, E.D.; Ross, S.B. (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Physics)

1990-12-01

208

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

209

Systematics and fragmentation of low-lying electric dipole strength  

SciTech Connect

We report on systematic investigations of low-lying electric dipole (E1) strength in atomic nuclei. Using the method of real photon scattering the dipole response of all stable N = 82 isotones has been measured with high resolution. In all cases a resonance like structure of E1 strength is observed in the energy region 5-8 MeV, which shows a strong fragmentation. The total integrated strength increases towards the proton poorer isotones, indicating a dependence of the total strength on the neutron-to-proton ratio. The experimental results are compared to microscopic calculations within the Quasi-particle Phonon Model (QPM). By including complex configurations of up to three phonons the calculation is able to reproduce also the fragmentation of the E1 strength and is in good agreement with the experimental observation.

Savran, D.; Fritzsche, M.; Mueller, S.; Pietralla, N.; Ponomarev, V. Yu.; Sonnabend, K. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstr. 9, D-64289 Darmstadt (Germany); Endres, J.; Hasper, J.; Zilges, A. [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany)

2009-01-28

210

Study By Spin Tracking of A Storage Ring For Deuteron Electric Dipole Moment  

SciTech Connect

Spin tracking of polarized deuterons for a proposed experiment to measure a possible Electric Dipole Moment (EDM) of the deuteron was done by using the codes UAL and SPINK. In the experiment the direction of spin polarization will be frozen using crossed electric and magnetic fields. Systematics, in particular the effects of non-linearities of the lattice on a beam with finite emittance and energy spread, have been extensively simulated and the effect of sextuple corrections to increase the spin coherence time has been studied.

Lin, F.; Malitsky, N. D.; Luccio, A. U.; Morse, W. M.; Semertzidis, Y. K. [Brookhaven National Laboratory, Upton, NY (United States); Onderwater, C. J. G. [University of Groningen, NL-9747AA Groningen (Netherlands); Orlov, Y. F. [Cornell University, Ithaca, NY (United States)

2009-08-04

211

Equilibrium values and dynamics of the net magnetic moment of a system of magnetic dipoles  

SciTech Connect

Equilibrium states of different systems formed by coupled spherical bodies with dipole magnetic moments have been investigated using a numerical analysis. The bistable states and the corresponding values of the net magnetic moment are determined for a number of planar and three-dimensional systems of dipoles, and the conditions providing the existence of orientational configurations of coupled dipoles involved in the bistability are analyzed. The disturbances of the magnetic moment due to the quasi-static passage of an additional dipole and the dynamic modes excited by a homogeneous alternating magnetic field and represented by periodic, quasi-periodic, and chaotic oscillations of the magnetic moment of the system are considered for several types of systems. The bifurcation diagrams of the dynamic modes are constructed, and the specific features typical of the systems under consideration are revealed.

Shutyi, A. M., E-mail: shuty@mail.r [Ulyanovsk State University (Russian Federation)

2010-02-15

212

Dipole interaction and magnetic anisotropy in gadolinium compounds  

NASA Astrophysics Data System (ADS)

The influence of the dipole interaction on the magnetic anisotropy of Gd compounds is investigated. Available data on ferromagnets and antiferromagnets with different crystal structures are discussed and complemented by new neutron scattering experiments on GdCu2In, GdAu2Si2, GdAu2, and GdAg2. If the propagation vector of the magnetic structure is known, the orientation of the magnetic moments as caused by the dipole interaction can be predicted by a straightforward numerical method for compounds with a single Gd atom in the primitive unit cell. The moment directions found by magnetic diffraction on GdAu2Si2, GdAu2, GdAg2, GdCu2Si2, GdNi2B2C, GdNi2Si2, GdBa2Cu3O7, GdNi5, GdCuSn, GdCu2In, GdCu4In, and GdX (X=Ag, Cu, S, Se, Sb, As, Bi, P) are compared to the predicted directions resulting in an almost complete accordance. Therefore, the dipole interaction is identified as the dominating source of anisotropy for most Gd compounds. The numerical method can be applied to a large number of other compounds with zero angular momentum.

Rotter, M.; Loewenhaupt, M.; Doerr, M.; Lindbaum, A.; Sassik, H.; Ziebeck, K.; Beuneu, B.

2003-10-01

213

The tau weak-magnetic dipole moment  

Microsoft Academic Search

We calculate the prediction for the anomalous weak-magnetic form factor of the tau lepton at q2 = M2 within the Standard Model. With all particles on-shell, this is an electroweak gauge-invariant quantity. Its value is a?w(MZ2)= ? (2.10+0.61 i) × 10?6. We show that the transverse and normal components of the single-tau polarization of tau pairs produced at e+e? unpolarized

J. Bernabéu; G. A. González-Sprinberg; M. Tung; J. Vidal

1995-01-01

214

Dipole corrector magnets for the LBNE beam line  

SciTech Connect

The conceptual design of a new dipole corrector magnet has been thoroughly studied. The planned Long-Baseline Neutrino Experiment (LBNE) beam line will require correctors capable of greater range and linearity than existing correctors, so a new design is proposed based on the horizontal trim dipole correctors built for the Main Injector synchrotron at Fermilab. The gap, pole shape, length, and number of conductor turns remain the same. To allow operation over a wider range of excitations without overheating, the conductor size is increased, and to maintain better linearity, the back leg thickness is increased. The magnetic simulation was done using ANSYS to optimize the shape and the size of the yoke. The thermal performance was also modeled and analyzed.

Yu, M.; Velev, G.; Harding, D.; /Fermilab

2011-03-01

215

Production of Austenitic Steel for the LHC Superconducting Dipole Magnets  

Microsoft Academic Search

The austenitic-steel collars are an important component of the LHC dipole magnets, operating at cryogenic temperature under high mechanical stress. The required steel, known as YUS 130S, has been specifically developed for this application by Nippon Steel Corporation (NSC), who was awarded a CERN contract in 1999 for the supply of 11 500 tonnes. In 2005-after six years of work-the

F. Bertinelli; F. Fudanoki; T. Komori; G. Peiro; L. Rossi

2006-01-01

216

Superconducting super collider second generation dipole magnet cryostat design  

Microsoft Academic Search

The Superconducting Super Collider, a planned colliding beam particle physics research facility, requires \\/approximately\\/10,000 superconducting devices for the control of high energy particle beams. The \\/approximately\\/7,500 collider ring superconducting dipole magnets require cryostats that are functional, cryogenically efficient, mass producible and cost effective. A second generation cryostat design has been developed utilizing the experiences gained during the construction, installation and

R. C. Niemann; R. C. Bossert; J. A. Carson; N. H. Engler; J. D. Gonczy; E. T. Larson; T. H. Nicol; T. Ohmori

1988-01-01

217

Detection of Nonpolar Ions in 2?3/2 States by Radioastronomy via Magnetic Dipole Transitions  

NASA Astrophysics Data System (ADS)

The possibility of magnetic dipole-induced pure rotational transitions in the interstellar medium is investi- gated for symmetric Hund's case (a) linear molecules, such as H-C?C-H+ ({\\widetilde X} 2?3/2u ), CO2 + ({\\widetilde X} 2?3/2g ), H-C?C-C?C-H+ ({\\widetilde X} 2?3/2g ), and N3 ({\\widetilde X} 2?3/2g ). These species lack an electric dipole moment and therefore cannot undergo pure rotational electric dipole transitions. These species can undergo pure rotational transitions via the parallel component of the magnetic dipole operator, however. The transition moments and Einstein A coefficients for the allowed pure rotational transitions are derived for a general Hund's case (a) linear molecule, and tabulated for the examples of H-C?C-H+ (2?3/2u ) and H-C?C-C?C-H+ (2?3/2g ). It is found that the rates of emission are comparable to collision rates in interstellar clouds, suggesting that this decay mechanism may be important in simulating rotational population distributions in diffuse clouds and for detecting these molecules by radioastronomy. Expected line positions for the magnetic dipole-allowed Ref (J) and Rfe (J) transitions of H-C?C-H+ (2?3/2u ), H-C?C-C?C-H+ (2?3/2g ), CO2 + (2?3/2g ), and N3 (2?3/2g ) are tabulated to assist in their observation by radioastronomy or in the laboratory.

Morse, Michael D.; Maier, John P.

2011-05-01

218

Experimental Upper Limit for the Permanent Electric Dipole Moment of RB85 by Optical-Pumping Techniques.  

National Technical Information Service (NTIS)

An optical-pumping experiment designed to detect a permanent electric dipole moment in the ground state of the Rb85 atom is described. It has the advantage of averaging out the motional magnetic fields that limit the more recent related atomic-beam result...

E. S. Ensberg

1966-01-01

219

Experimental search for the electron Electric Dipole Moment using solid state techniques  

NASA Astrophysics Data System (ADS)

We report results of an experimental search for the permanent Electric Dipole Moment (EDM) of the electron using a solid state system. The experiment uses a paramagnetic insulator (gadolinium gallium garnet) with a large magnetic response at low temperatures. The presence of the electron EDM leads to a finite magnetization when the garnet sample is subjected to a strong electric field. The resulting magnetization can be measured using a superconducting quantum interference device (SQUID) as a magnetometer. With considerable efforts made towards controlling various sources of systematic effects, the experiment is currently free of spurious signals larger than the SQUID noise. We report the value of electron EDM of (-5.57 ± 7.98 ± 0.12) × 10-25e-cm with 120 hours of data.

Kim, Y. J.; Liu, C.-Y.; Lamoreaux, S. K.; Reddy, G.

2011-09-01

220

Electric Dipole Moments in the Limit of Heavy Superpartners  

NASA Astrophysics Data System (ADS)

Supersymmetric loop corrections induce potentially large CP-violating couplings of the Higgs bosons to nucleons and electrons that do not vanish in the limit of heavy superpartners. The Higgs-mediated CP-odd four-fermion operators are enhanced by tan(3? and induce electric dipole moments of heavy atoms which exceed the current experimental bounds for the electroweak scale Higgs masses and tan(?>~10. If only the first two sfermion generations are heavy, the Higgs-mediated contributions typically dominate over the Barr-Zee type two-loop diagrams at tan(?>30.

Lebedev, Oleg; Pospelov, Maxim

2002-08-01

221

Reappraisal of the Electric Dipole Moment Enhancement Factor for Thallium  

SciTech Connect

The electric dipole moment (EDM) enhancement factor of atomic Tl is of considerable interest as it has been used in determining the most accurate limit on the electron EDM to date. However, its value varies from -179 to -1041 in different approximations. In view of the large uncertainties associated with many of these calculations, we perform an accurate calculation employing the relativistic coupled-cluster theory and obtain -466, which in combination with the most accurate measurement of Tl EDM [Phys. Rev. Lett. 88, 071805 (2002)] yields a new limit for the electron EDM: |d{sub e}|<2.0x10{sup -27}e cm.

Nataraj, H. S. [Cyclotron and Radioisotope Center, Tohoku University, Sendai 9808578 (Japan); Sahoo, B. K. [Theoretical Physics Division, Physical Research Laboratory, Ahmedabad 380009 (India); Das, B. P. [Theoretical Astrophysics Group, Indian Institute of Astrophysics, Bangalore 560034 (India); Mukherjee, D. [Indian Association for the Cultivation of Sciences, Kolkata 700032 (India)

2011-05-20

222

Electric dipole moments in the limit of heavy superpartners.  

PubMed

Supersymmetric loop corrections induce potentially large CP-violating couplings of the Higgs bosons to nucleons and electrons that do not vanish in the limit of heavy superpartners. The Higgs-mediated CP-odd four-fermion operators are enhanced by tan((3)beta and induce electric dipole moments of heavy atoms which exceed the current experimental bounds for the electroweak scale Higgs masses and tan(beta greater, similar 10. If only the first two sfermion generations are heavy, the Higgs-mediated contributions typically dominate over the Barr-Zee type two-loop diagrams at tan(beta>30. PMID:12225182

Lebedev, Oleg; Pospelov, Maxim

2002-08-15

223

Neutron electric dipole moment in CP violating BLMSSM  

NASA Astrophysics Data System (ADS)

Considering the CP violating phases, we analyze the neutron electric dipole moment (EDM) in a CP violating supersymmetric extension of the standard model where baryon and lepton numbers are local gauge symmetries(BLMSSM). The contributions from the one loop diagrams and the Weinberg operators are taken into account. Adopting some assumptions on the relevant parameter space, we give the numerical results analysis. The numerical results for the neutron EDM can reach 1.05 × 10-25( e.cm), which is about the experimental upper limit.

Zhao, Shu-Min; Feng, Tai-Fu; Yan, Ben; Zhang, Hai-Bin; Zhang, Yin-Jie; Chen, Biao; Li, Xue-Qian

2013-10-01

224

Stationary Generalization of the Bonnor Magnetic Dipole Solution  

NASA Astrophysics Data System (ADS)

An exact asymptotically flat 3-parameter solution of the Einstein--Max\\-well equations is presented that reduces to the Bonnor magnetic dipole solution in the magnetostatic limit, and to the Tomimatsu-Sato $\\delta=2$ solution in the stationary pure vacuum limit. This solution is the simplest possible one admitting the polynomial representation in the spheroidal coordinates ($x,y$) and able to describe the exterior field of a magnetized spinning mass. A multipole criterion for the choice of the parameters in the Einstein--Maxwell spacetimes is also formulated.

Manko, V. S.; Ruiz, E.

1997-08-01

225

Magnetic dipole sequences in {sup 83}Rb  

SciTech Connect

High-spin states in {sup 83}Rb were populated in the reaction {sup 11}B+{sup 76}Ge at beam energies of 45 and 50 MeV. {gamma} rays were detected with the spectrometer GASP. The level scheme of {sup 83}Rb was extended up to 13.9 MeV. Mean lifetimes of 23 levels were determined using the Doppler-shift-attenuation method. Among the bands newly established is a sequence comprising intense M1 transitions and crossover E2 transitions. This sequence turns out to be irregular and thus shows that magnetic rotation as observed in the neighboring odd-odd isotopes is not realized in this odd-even nuclide. Excited states in {sup 83}Rb were interpreted in terms of the shell model using the model space {pi}(0f{sub 5/2},1p{sub 3/2},1p{sub 1/2},0g{sub 9/2}) {nu}(1p{sub 1/2},0g{sub 9/2}). The configurations predicted for the negative-parity M1 sequence reproduce the M1 transition strengths fairly well.

Schwengner, R.; Schnare, H.; Wagner, A.; Doenau, F. [Institut fuer Strahlenphysik, Forschungszentrum Dresden-Rossendorf, D-01314 Dresden (Germany); Rainovski, G. [Faculty of Physics, University of Sofia, BG-1164 Sofia (Bulgaria); Frauendorf, S. [Institut fuer Strahlenphysik, Forschungszentrum Dresden-Rossendorf, D-01314 Dresden (Germany); Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Jungclaus, A. [Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, E-28006 Madrid (Spain); Hausmann, M.; Lieb, K. P. [II. Physikalisches Institut, Universitaet Goettingen, D-37073 Goettingen (Germany); Yordanov, O. [Institute for Nuclear Research and Nuclear Energy, BAS, BG-1784 Sofia (Bulgaria); Napoli, D. R.; De Angelis, G.; Axiotis, M. [INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Marginean, N. [Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, P. O. Box MG-6 (Romania); Brandolini, F.; Alvarez, C. Rossi [INFN and Dipartimento di Fisica dell'Universita di Padova, I-35131 Padova (Italy)

2009-10-15

226

Development Of Y3Fe5O12 Nano-Magnetic Feeder For Em Source Of An Intelligent Horizontal Twin Dipoles  

Microsoft Academic Search

Direct detection of hydrocarbon by an active source using electromagnetic (EM) energy termed at seabed logging (SBL) has shown very promising results. However, powerful horizontal electrical dipole (HED) which could improve data acquisition still remains a challenge. This paper the presents development of a twin dipole with yttrium iron garnet based magnetic feeder. The toroid shape yttrium iron garnet samples

Noorhana Yahya; Tan Wei Zhu

2009-01-01

227

Dipole Model of Electric Pulse Generation Caused by the Relaxation Processes in the Earth's Crust  

NASA Astrophysics Data System (ADS)

Study of electric and magnetic (EM) signals in the Earth's crust is of interest from a viewpoint of both establishing mechanisms and conditions for generation of geophysical fields and interpreting physical and mechanical characteristics of a hierarchically structured medium. In a previously developed model [1] it was proposed that generation of electromagnetic impulses in the Earth's crust with low water content was a result of a quasi independent displacement of a structural block being relaxed in constrained conditions. A transient electric current system generated on an active side of the structural block due to electric polarization of an inter-block gap content was considered as a source of EM radiation. In a new numerical model we use a set of Hertz's dipoles distributed over the active surface. Time dependence of the dipole moments was defined by displacement of the structural unit. To estimate EM signals the full system of Maxwell equations in a conductive medium was solved. The results of numerical simulations were compared with electric field records in a surface layer of the Earth's crust in the area of influence of the tectonically active Kurai structure (Gornyi Altai) [2]. The amplitudes of electric fields at a distance of 50-100 linear block sizes obtained in numerical simulations are in good agreement with the instrumental observations, which proves the validity of our model for the estimation of electric effects in the low moisture rock medium.

Losseva, T. V.; Spivak, A.; Kuzmicheva, M. Y.

2011-12-01

228

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

229

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

230

The Electric Dipole Moment of Iridium Monosilicide, IrSi  

NASA Astrophysics Data System (ADS)

The optical spectrum of iridium monosilicide (IrSi) was recently observed using REMPI spectroscopy in the range 17200 to 23850 cm^{-1}. The observation was supported by an ab initio calculation which predicted a X^{2}?_{5/2} state. Here, we report on the analysis of the optical Stark effect for the X^{2}?_{5/2} and [16.0]1.5 (v=6) states. The (6,0)[16.0]1.5 - X^{2}?_{5/2} and the (7,0)[16.0]3.5- X^{2}?_{5/2} bands of IrSi have been recorded using high-resolution laser-induced fluorescence spectroscopy. The observed optical Stark shifts for the ^{193}IrSi and ^{191}IrSi isotopologues were analyzed to produce the electric dipole moments of -0.4139(64)D and 0.7821(63)D for the X^{2}?_{5/2} and [16.0]1.5 (v=6) states, respectively. The negative sign of electric dipole moment of the X^{2}?_{5/2} state is supported by high-level quantum-chemical calculations employing all-electron scalar-relativistic CCSD(T) method augmented with spin-orbit corrections as well as corrections due to full triple excitations. In particular, electron-correlation effects have been shown to be essential in the prediction of the negative sign of the dipole moment. A comparison with other iridium containing molecules will be made. Maria A. Garcia, Carolin Vietz, Fernando Ruipérez, Michael D. Morse, and Ivan Infante, Kimika Fakultatea, Euskal Herriko. J. Chem. Phys., (submitted)

Le, Anh; Steimle, Timothy C.; Cheng, Lan; Stanton, John F.

2013-06-01

231

Magnetic dipole localization using the gradient rate tensor measured by a five-axis magnetic gradiometer with known velocity  

Microsoft Academic Search

The use of the magnetic gradient tensor in the point-by-point localization of a magentic dipole was first demonstrated by Wynn in 1971, with a more explicit solution derived by Frahm in 1972. This algorithm maps the five independent components of the magnetic gradient tensor at a point into the dipole bearing vector and the dipole moment vector scaled by the

W. M. Wynn

1995-01-01

232

Study of atomic permanent electric dipole moments for CP violation  

NASA Astrophysics Data System (ADS)

Permanent electric dipole moments of non-degenerate physical systems are direct evidences of Parity (P) and time-reversal (T) symmetry violations. These symmetries are inturn closely related to CP violation through the CPT theorem. CP violation is a pre-requisite for the matter anti-matter asymmety in the Universe. If C or CP were good symmetries of nature, particle production would create anti-particle production in equal number and there wouldn't be a baryon asymmetry. The magnitude of CP violation predicted by the Standard Model is insufficient to account for the observed baryon asymmetry. We have performed an atomic physics calculation of the electric dipole moment of the Hg(mercury), which to date is the most accurate calculation as it incorporates important electron correlation effects. Using the P and T violating coupling constants at the atomic level, it is possible to extract the CP violating parameters at the elementary particle level. Our calculation is model independent many-body calculation and hence, our calculated parameters can be used not only as a test for models of particle physics, but also for a better understanding of the process of baryogenesis in the early universe. In my talk I would like to highlight our latest results on the P and T violating parameters of the Hg, Yb and Ra atoms at the atomic level and relate them to some important CP violating parameters at the elementary particle level.

Latha, K. V. P.

2012-07-01

233

Electric dipole moment signatures of PeV-scale superpartners  

NASA Astrophysics Data System (ADS)

A possible supersymmetric interpretation of the new Higgs-like 126 GeV resonance involves a high sfermion mass scale, from tens of TeV to a PeV or above. This scale provides sufficiently large loop corrections to the Higgs mass and can naturally resolve the constraints from flavor-violating observables, even with a generic flavor structure in the sfermion sector. We point out that such high scales could still generate CP-violating electric dipole moments at interesting levels due to the enhancement of left-right sfermion mixing. We illustrate this by saturating the light fermion mass corrections from the sfermion threshold, leaving the gaugino masses unconstrained. In this framework, we find that the current electric dipole moment bounds probe energy scales of 0.1 PeV or higher; this is competitive with the reach of ?K and more sensitive than other hadronic and leptonic flavor observables. We also consider the sensitivity to higher-dimensional supersymmetric operators in this scenario, including those that lead to proton decay.

McKeen, David; Pospelov, Maxim; Ritz, Adam

2013-06-01

234

Magnetic dipole and higher pole interaction on a square lattice.  

PubMed

We have studied the magnetic interaction of circular magnetic islands with a dipole character on a square lattice. The square pattern consists of lithographically prepared polycrystalline PdFe islands, 150 nm in diameter and a periodicity of 300 nm. Below the Curie temperature at 260 K, the islands are in a single domain state with isotropic in-plane magnetization. Below 160 K, there is an onset of interisland interaction that leads to a change of the shape of the hysteresis, an increase of coercivity, and a development of in-plane anisotropy. Photoemission electron microscopy with circularly polarized incident x rays tuned to the L3 edge of Fe confirms the increasing correlation of the magnetic islands and the formation of elongated chains, as predicted by Vedmedenko et al. [Phys. Rev. Lett. 95, 207202 (2005)] for contributions from pole interactions of higher order than the dipolar one. Neighboring chains are found to be irregularly oriented either parallel or antiparallel. PMID:23679771

Ewerlin, Melanie; Demirbas, Derya; Brüssing, Frank; Petracic, Oleg; Ünal, Ahmet A; Valencia, Sergio; Kronast, Florian; Zabel, Hartmut

2013-04-26

235

Magnetic Dipole and Higher Pole Interaction on a Square Lattice  

NASA Astrophysics Data System (ADS)

We have studied the magnetic interaction of circular magnetic islands with a dipole character on a square lattice. The square pattern consists of lithographically prepared polycrystalline PdFe islands, 150 nm in diameter and a periodicity of 300 nm. Below the Curie temperature at 260 K, the islands are in a single domain state with isotropic in-plane magnetization. Below 160 K, there is an onset of interisland interaction that leads to a change of the shape of the hysteresis, an increase of coercivity, and a development of in-plane anisotropy. Photoemission electron microscopy with circularly polarized incident x rays tuned to the L3 edge of Fe confirms the increasing correlation of the magnetic islands and the formation of elongated chains, as predicted by Vedmedenko et al. [Phys. Rev. Lett. 95, 207202 (2005)] for contributions from pole interactions of higher order than the dipolar one. Neighboring chains are found to be irregularly oriented either parallel or antiparallel.

Ewerlin, Melanie; Demirbas, Derya; Brüssing, Frank; Petracic, Oleg; Ünal, Ahmet A.; Valencia, Sergio; Kronast, Florian; Zabel, Hartmut

2013-04-01

236

Green's functions computation of the EMI due to electric dipole sources inside a rectangular cavity  

Microsoft Academic Search

Summary form only given. The EMI of a rectangular enclosure excited by internal electric dipole sources is presented. The interaction between the sources and the enclosure is described by using the dyadic Green's function. Our detailed approach for electric dipole sources are given in a graphical form. The cavity walls are assumed to be perfect conductors. First a small electric

S. K. Goudos; J. N. Sahalos

2000-01-01

237

Electric-dipole-forbidden nuclear transitions driven by super-intense laser fields  

SciTech Connect

Electric-dipole-forbidden transitions of nuclei interacting with super-intense laser fields are investigated by considering stable isotopes with suitable low-lying first excited states. Different classes of transitions are identified, and all magnetic sublevels corresponding to the near-resonantly driven nuclear transition are included in the description of the nuclear quantum system. We find that large transition matrix elements and convenient resonance energies qualify nuclear M1 transitions as good candidates for the coherent driving of nuclei. We discuss the implications of resonant interaction of intense laser fields with nuclei beyond the dipole approximation for the controlled preparation of excited nuclear states and important aspects of possible experiments aimed at observing these effects.

Palffy, Adriana; Evers, Joerg; Keitel, Christoph H. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

2008-04-15

238

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

239

Space propulsion by fusion in a magnetic dipole  

SciTech Connect

A conceptual design is discussed for a fusion rocket propulsion system based on the magnetic dipole configuration. The dipole is found to have features well suited to space applications. Example parameters are presented for a system producing a specific power of 1 kW/kg, capable of interplanetary flights to Mars in 90 days and to Jupiter in a year, and of extra-solar-system flights to 1000 astronomical units (the Tau mission) in 20 years. This is about 10 times better specific power toward 10 kW/kg are discussed, as in an approach to implementing the concept through proof-testing on the moon. 21 refs., 14 figs., 2 tabs.

Teller, E.; Glass, A.J.; Fowler, T.K. (Lawrence Livermore National Lab., CA (USA)); Hasegawa, A. (AT and T Bell Labs., Murray Hill, NJ (USA)); Santarius, J.F. (Wisconsin Univ., Madison, WI (USA). Fusion Technology Inst.)

1991-04-12

240

Strong dependence of ultracold chemical rates on electric dipole moments  

SciTech Connect

We use the quantum threshold laws combined with a classical capture model to provide an analytical estimate of the chemical quenching cross sections and rate coefficients of two colliding particles at ultralow temperatures. We apply this quantum threshold model (QT model) to indistinguishable fermionic polar molecules in an electric field. At ultracold temperatures and in weak electric fields, the cross sections and rate coefficients depend only weakly on the electric dipole moment d induced by the electric field. In stronger electric fields, the quenching processes scale as d{sup 4(L+(1/2))} where L>0 is the orbital angular-momentum quantum number between the two colliding particles. For p-wave collisions (L=1) of indistinguishable fermionic polar molecules at ultracold temperatures, the quenching rate thus scales as d{sup 6}. We also apply this model to pure two-dimensional collisions and find that chemical rates vanish as d{sup -4} for ultracold indistinguishable fermions. This model provides a quick and intuitive way to estimate chemical rate coefficients of reactions occuring with high probability.

Quemener, Goulven; Bohn, John L. [JILA, University of Colorado, Boulder, Colorado 80309-0440 (United States)

2010-02-15

241

Improved Experimental Limit on the Electric Dipole Moment of the Neutron  

SciTech Connect

An experimental search for an electric dipole moment (EDM) of the neutron has been carried out at the Institut Laue-Langevin, 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. The results may be interpreted as an upper limit on the neutron EDM of vertical bar d{sub n} vertical bar <2.9x10{sup -26}e cm (90% C.L.)

Baker, C. A.; Iaydjiev, P.; Ivanov, S. N. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Doyle, D. D.; Harris, P. G.; May, D. J. R.; Pendlebury, J. M.; Richardson, J. D.; Shiers, D.; Smith, K. F. [Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Geltenbort, P. [Institut Laue-Langevin, BP 156, F-38042 Grenoble Cedex 9 (France); Green, K.; Grinten, M. G. D. van der [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom)

2006-09-29

242

Passive Superconductor: A Viable Method of Controlling Magnetization Multipoles in the SSC Dipole.  

National Technical Information Service (NTIS)

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 decapol...

M. A. Green

1989-01-01

243

Magnetic design and analysis of the SSC high energy booster dipole magnets  

NASA Astrophysics Data System (ADS)

This paper presents key magnetic design considerations and analyses performed on the Superconducting Super Collider (SSC) High Energy Booster Dipole Magnets (HDM). The design considerations include: optimization of the coil cross section to establish low magnetic field harmonic content and specified field strength throughout a wide range of cable azimuthal sizes; effects of wedge geometry and cable stacking procedures on the field harmonics; and effects of yoke geometry and material variations on the central field strength and harmonics of the magnet.

Krefta, Mark P.; Chuboy, Helen L.; Johnson, Dave C.; Garg, Vijay

1994-07-01

244

Laser trapping of radium for an electric dipole moment measurement  

NASA Astrophysics Data System (ADS)

The best limits on time-reversal violation in the nuclear sector are currently set through electric dipole moment (EDM) searches on the neutron and Hg-199. Recent theoretical calculations predict that atomic EDM measurements of certain octupole-deformed nuclei, e.g., in the radium isotopic chain, are two to three orders of magnitude more sensitive to the underlying time-reversal violation than the one in Hg-199. Ra-225, with nuclear spin 1/2 and a radioactive half-life of 15 days, is a particularly attractive candidate for a tabletop EDM measurement based on a laser-cooling and trapping approach. Towards this end, we have successfully cooled and trapped atoms of Ra-225 and Ra-226 in a magneto-optical trap -- a first for this rare element -- and have identified black-body radiation as a beneficial source of optical repumping. We will present our laser cooling scheme and ongoing measurements of atomic level energies, lifetimes, isotope shifts and hyperfine structure in radium and discuss our progress towards an EDM measurement of Ra-225 based on an optical dipole trap. This work is supported by DOE, Office of Nuclear Physics, under contract No. DE-AC02-06CH11357.

Mueller, P.; Sulai, I. A.; Trimble, W.; Ahmad, I.; Bailey, K.; Bishof, M.; Greene, J. P.; Guest, J. R.; Holt, R. J.; Lu, Z.-T.; O'Connor, T. P.; Gould, H. A.

2008-05-01

245

Progress towards an electric dipole moment measurement in radium-225  

NASA Astrophysics Data System (ADS)

The search for a permanent electric dipole moment (EDM) in an atom is a sensitive test of time-reversal symmetry violation. In the nuclear sector, the best limit for T-violation through EDMs is set by measurements of the EDM of the neutron and of the diamagnetic atom Hg-199. Collective and mean field calculations suggest that because of the octupole deformation of its nucleus, Ra-225 (a spin .5ex1-.1em/ -.15em.25ex2 diamagnetic atom with a half life of 15 days) would be two to three orders of magnitude more sensitive to underlying T-violating interactions in the nucleus than Hg-199. Our search for a permanent EDM in Ra-225 involves measuring the nuclear spin precession of polarized Ra-225 atoms held in an optical dipole trap. We will report on recent measurements of atomic properties in Ra as well as progress in the construction of the experiment. This work is supported by DOE, Office of Nuclear Physics, under contract No. DE-AC02-06CH11357.

Sulai, I. A.; Trimble, W.; Ahmad, I.; Bailey, K.; Gould, H. A.; Graner, B.; Greene, J. P.; Holt, R. J.; Korsch, W.; Lu, Z.-T.; Mueller, P.; O'Connor, T. P.

2009-05-01

246

Muon anomalous magnetic dipole moment in supersymmetric theories  

Microsoft Academic Search

We study the muon anomalous magnetic dipole moment in supersymmetric\\u000atheories. The impact of the recent Brookhaven E821 experimental measurement on\\u000aboth model-independent and model-dependent supersymmetric parameter spaces is\\u000adiscussed in detail. We find that values of tan\\\\beta as low as 3 can be\\u000aobtained while remaining within the E821 one-sigma bound. This requires a light\\u000asmuon; however, we show

Stephen P. Martin; James D. Wells

2001-01-01

247

Gamow-Teller and magnetic dipole transitions for ?, ? and ?  

NASA Astrophysics Data System (ADS)

We discuss the effects of the quenching and spreading of the Gamow-Teller (GT) strengths for 0954-3899/24/8/020/img4 and 0954-3899/24/8/020/img5 due to the mixing of the sd-shell components and the halo effects as well as the 0954-3899/24/8/020/img6-hole contributions. The magnetic dipole (M1) transitions between the isobaric analogue state and the GT states for 0954-3899/24/8/020/img4 are studied. It has been found that strong M1 transitions from the IAS occur selectively to several (GT) states.

Suzuki, Toshio

1998-08-01

248

Interpretation of the dipole-dipole electrical-resistivity survey, Tuscarora Geothermal Area, Elko County, Nevada  

SciTech Connect

Interpretation of Tuscarora geothermal area model results has suggested that low resistivity zones on two dipole-dipole lines and possibly a third are related to thermal fluids. These two-dimensional models have delineated what appear to be aquifers within the valley sediments and the Tertiary volcanics. Structural breaks noted at the surface by geologic mapping are also evident in the interpretive models. The area southeast of the hot springs in Hot Creek is poorly delineated by the current dipole-dipole coverage, yet this appears to be the most promising prospect area based upon the available data coverage. Exploratory drilling is currently moving in this direction. Perhaps additional dipole-dipole lines could aid in the selection of future drill sites.

Mackelprang, C.E.

1982-02-01

249

First integrated test of the superconducting magnet systems for the Levitated Dipole Experiment (LDX)  

Microsoft Academic Search

The Levitated Dipole Experiment (LDX) is an innovative approach to explore the magnetic confinement of a fusion plasma offering the possibility of an improved fusion power source. In this concept, a magnetic dipole (a superconducting solenoid) is magnetically levitated for several hours at the center of a 5m diameter, 3m tall vacuum chamber. The Floating coil (F-coil) is designed for

A. Zhukovsky; P. C. Michael; J. H. Schultz; B. A. Smith; J. V. Minervini; J. Kesner; A. Radovinsky; D. Garnier; M. Mauel

2005-01-01

250

Three-dimensional computation of magnetic fields and Lorentz forces of an LHC dipole magnet.  

National Technical Information Service (NTIS)

Magnetic fields and Lorentz forces of an LHC dipole magnet are calculated using the method of image currents to represent the effect of the iron shield. The calculation is performed for coils of finite length using a parametrization for coil heads of cons...

C. Daum D. Avest

1989-01-01

251

Controlling a Nanowire Spin-Orbit Qubit via Electric-Dipole Spin Resonance  

NASA Astrophysics Data System (ADS)

A semiconductor nanowire quantum dot with strong spin-orbit coupling (SOC) can be used to achieve a spin-orbit qubit. In contrast to a spin qubit, the spin-orbit qubit can respond to an external ac electric field, an effect called electric-dipole spin resonance. Here we develop a theory that can apply in the strong SOC regime. We find that there is an optimal SOC strength ?opt=2/2, where the Rabi frequency induced by the ac electric field becomes maximal. Also, we show that both the level spacing and the Rabi frequency of the spin-orbit qubit have periodic responses to the direction of the external static magnetic field. These responses can be used to determine the SOC in the nanowire.

Li, Rui; You, J. Q.; Sun, C. P.; Nori, Franco

2013-08-01

252

Nuclear electric dipole moment of {sup 3}He  

SciTech Connect

In the no-core shell model (NCSM) framework, we calculate the {sup 3}He electric dipole moment (EDM) generated by parity- and time-reversal violation in the nucleon-nucleon interaction. While the results are somehow sensitive to the interaction model chosen for the strong two- and three-body interactions, we demonstrate the pion-exchange dominance to the EDM of {sup 3}He, if the coupling constants for {pi}, {rho} and {omega}-exchanges are of comparable magnitude, as expected. Finally, our results suggest that a measurement of {sup 3}He EDM would be complementary to the currently planned neutron and deuteron experiments, and would constitute a powerful constraint to the models of the pion P- and T-violating interactions.

Stetcu, I.; Friar, J. L.; Hayes, A. C. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Liu, C.-P. [Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Navratil, P. [Lawrence Livermore National Laboratory, P.O. Box 808, L-414, California 94551 (United States)

2009-01-28

253

Thermal annealing-induced electric dipole relaxation in natural alexandrite  

NASA Astrophysics Data System (ADS)

Electrical properties of natural alexandrite (BeAl2O4:Cr3+) are investigated by the thermally stimulated depolarization current (TSDC) technique. Samples are submitted to consecutive annealing processes and TSDC is carried out after each annealing, yielding bands with different parameters. These bands are fitted by a continuous distribution of relaxation parameters: activation energy and pre-exponential factor of the Arrhenius equation. It has been observed that annealing influences the dipole relaxation behavior, since it promotes a modification of Fe3+ and Cr3+ impurity distributions on sites of distinct symmetry: Al1 and Al2. In order to have a reference for comparison, TSDC is also carried out on a synthetic alexandrite sample, where the only impurity present is Cr3+ ion.

Scalvi, Rosa M. Fernandes; Li, Maximo Siu; Scalvi, Luis V. A.

2005-02-01

254

Neutron electric dipole moment: Constituent dressing and compositeness  

SciTech Connect

Contributions to the neutron's electric dipole moment (EDM), d{sub n}, are calculated using a well-constrained ansatz for the nucleon's Poincare covariant Fadde'ev amplitude. The momentum-dependent quark dressing amplifies the contribution from the current-quarks' EDMs; and dressed-quark confinement and binding make distinguishable the effect of the two CP and T violating interactions: i{gamma}{sub 5}{sigma}{sub {mu}{nu}}(p{sub 1}-p{sub 2}){sub {nu}} and {gamma}{sub 5}(p{sub 1}+p{sub 2}){sub {mu}}, where p{sub 1,2} are the current-quarks' momenta. The value of |d{sub n}| obtained using the current-quark EDMs generated by a minimal three Higgs doublet model of spontaneous CP violation is close to the current experimental upper bound.

Hecht, M. B.; Roberts, C. D.; Schmidt, S. M.

2001-08-01

255

Calculating the external magnetic force on the Earth's dipole  

NASA Astrophysics Data System (ADS)

The force exerted by the external perturbation magnetic field on the magnetic moment of a planet is related to various aspects of stress balance in the magnetosphere and its interaction with the solar wind. The total force applied by the solar wind must ultimately be exerted on the planet itself, which contains essentially all the mass of the entire system (the mass fraction in the Earth's magnetosphere is less than ~ 10-20 of the total). The force is transmitted through the magnetosphere primarily (and near the planet almost exclusively) by the magnetic field. In the simplest approximation (Siscoe, 1966), the force is applied directly as the gradient of the external perturbation field at the dipole. More recently (Siscoe and Siebert, 2006; Vasyliunas, 2007), it has been recognized that coupling by Birkeland currents between the ionosphere and the magnetosphere allows the external force to be transmitted also as a J × B-c force in the ionosphere; further transmission to the planet itself then has to proceed as a mechanical stress. Because of the converging dipole field, the force in the ionosphere is greatly amplified and much stronger than the initially imposed force from the magnetosphere or solar wind, an effect sometimes described as the mechanical advantage of the magnetosphere (Vasyliunas, 2007). Empirical estimates of the force thus provide a sensitive (albeit indirect and imprecise) indicator of stresses in the outer magnetosphere, as well as a direct measure of the global input of linear momentum into the atmosphere. The total magnetic force on the planet can be calculated from measurements of magnetic perturbations by integrating the Maxwell stress tensor over the surface. I derive the formula for the three vector components of the force in terms of the conventional geomagnetic quantities, integrated over latitude and longitude with appropriate weighting factors (which are not always intuitively obvious and in some cases reverse sign between low and high latitudes).

Vasyliunas, Vytenis M.

2010-05-01

256

Electric dipole polarizabilities of alkali-metal ions from perturbed relativistic coupled-cluster theory  

NASA Astrophysics Data System (ADS)

We use the perturbed relativistic coupled-cluster theory to compute the static electric dipole polarizabilities of the singly ionized alkali-metal atoms, namely, Na+, K+, Rb+, Cs+, and Fr+. The computations use the Dirac-Coulomb-Breit Hamiltonian with the no-virtual-pair approximation and we also estimate the correction to the static electric dipole polarizability arising from the Breit interaction.

Chattopadhyay, S.; Mani, B. K.; Angom, D.

2013-04-01

257

SSC 50 mm dipole magnet cryostat thermal measurement results  

SciTech Connect

A prototype Superconducting Super Collider (SSC) 50 mm dipole magnet cryostat, DCA323, was instrumented at Fermilab and delivered to the SSC Laboratory for installation into the accelerator systems string test facility. In series with other magnets, the instrumented cryostat will be used to quantify and verify cryostat thermal performance with respect to design requirements. Prior to leaving Fermilab, DCA323 was subjected to magnetic testing at the Magnet Test Facility (MTF). This presented an opportunity to obtain preliminary thermal performance data under simulated operating conditions. It should be noted that measurements of overall cryostat thermal performance were not possible during the MTF measurements as the magnet test stands are designed for magnetic rather than thermal testing. They are not designed to limit heat inleak to the ends of the cryostat, which has been shown to have a significant effect on overall measured thermal performance. Nonetheless, these measurements do offer insight into the performance of several of the cryostat components and sub-systems.

Boroski, W.N.; Nicol, T.H.; Ruschman, M.K.; Schoo, C.J.

1993-05-01

258

Magnetic dipole transitions in 4d{sup N} configurations of tungsten ions  

SciTech Connect

Magnetic dipole transitions between the levels of ground 4d{sup N} configurations of tungsten ions were analyzed by employing a large basis of interacting configurations. Previously introduced configuration interaction strength between two configurations was used to determine the configurations with the largest contribution to wave functions of atomic states for the considered configurations. Collisional-radiative modeling was performed for the levels of the ground configuration coupled through electric dipole transitions with 4p{sup 5}4d{sup N+1} and 4d{sup N-1}4f configurations. New identification of some lines observed in the electron-beam ion trap plasma was proposed based on calculations in which wavelength convergence was reached.

Jonauskas, V.; Kisielius, R.; Kyniene, A.; Kucas, S.; Norrington, P. H. [Institute of Theoretical Physics and Astronomy, Vilnius University, A. Gostauto 12, LT-01108 Vilnius (Lithuania); Department of Applied Mathematics and Theoretical Physics, Queen's University of Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdon (United Kingdom)

2010-01-15

259

Spectrometer sensitivity calibration in the extreme uv by means of branching ratios of magnetic dipole lines  

SciTech Connect

Relative intensity measurements of various line pairs resulting from magnetic dipole transitions within the configurations s/sup 2/p/sup 2/ and s/sup 2/p/sup 4/, in conjunction with calculated transition probabilities, have been used to determine the wavelength dependence of the sensitivity of a grazing incidence spectrometer, in the range 400 to 1000 A. Emissions from Cr XIX, Fe XXI, Ni XXI and XXIII, Cu XXIV, and Zr XXVII ions in PLT tokamak discharges were used for this purpose. Absolute sensitivity of the spectrometer at selected wavelengths had been determined by the traditional hydrogen, helium, carbon, and oxygen electric-dipole line pairs from the same discharges. Similar attempts to use transitions in the s/sup 2/p/sup 3/ configurations in Cr XVIII, Zr XXVI, and Mo XXVIII ions resulted in significant discrepancies that are ascribed to uncertainties in the corresponding calculated transition probabilities.

Denne, B.; Hinnov, E.

1984-04-01

260

Monte Carlo simulations of flexible molecules in a static electric field: electric dipole and conformation  

NASA Astrophysics Data System (ADS)

We have performed Monte Carlo replica-exchange method calculations on the gas phase tryptophan-glycine dipeptide in a static electric field. At low electric field, the average dipole of the molecule follows the Langevin-Debye equation. At high electric field, a deviation from this law is observed and the analysis of the results shows that the external field modifies the conformation of the molecules. This opens the way to a possible control of the conformation of gas phase biomolecules with static electric fields.

Poulain, P.; Antoine, R.; Broyer, M.; Dugourd, P.

2005-01-01

261

Ultracold molecular collisions in combined electric and magnetic fields  

NASA Astrophysics Data System (ADS)

We consider collisions of electric and magnetic polar molecules, taking the OH radical as an example, subject to combined electric and magnetic static fields. We show that the relative orientation of the fields has an important effect on the collision processes for different fields' magnitudes at different collision energies. This is due to the way the molecules polarize in the combined electric and magnetic fields and hence the way the electric dipole-dipole interaction rises. If OH molecules are confined in magnetic quadrupole traps and if an electric field is applied, molecular collisions will strongly depend on the position as well as the velocity of the molecules. Consequences on the molecular dynamics are discussed.

Quéméner, Goulven; Bohn, John L.

2013-07-01

262

6. 4 Tesla dipole magnet for the SSC  

SciTech Connect

A design is presented for a dipole magnet suitable for the proposed SSC facility. Test results are given for model magnets of this design 1 m long and 4.5 m long. Flattened wedge-shaped cables (''keystoned'') are used in a graded, two-layer ''cos theta'' configuration with three wedges to provide sufficient field uniformity and mechanical rigidity. Stainless steel collars 15 mm wide, fastened with rectangular keys, provide structural support, and there is a ''cold'' iron flux return. The outer-layer cable has 30 strands of 0.0255 in. dia NbTi multifilamentary wire with Cu/S.C. = 1.8, and the inner has 23 strands of .0318 in. dia wire with Cu/S.C. = 1.3. Performance data is given including training behavior, winding stresses, collar deformation, and field uniformity.

Taylor, C.E.; Caspi, S.; Gilbert, W.; Meuser, R.; Mirk, K.; Peters, C.; Scanlan, R.; Dahl, P.; Cottingham, J.; Hassenzahl, W.

1985-05-01

263

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

264

Magnetic properties of iron yoke laminations for SSC dipole magnets  

SciTech Connect

We examine the magnetic properties for the iron used in the SSC yoke laminations so that the accelerator tolerances can be met. The accelerator requirements for field quality specify a tolerance on the variation in the central field. At machine injection the variation in field is attributed to coercivity, H{sub c}. Requirements on the magnitude and the variation of H{sub c} are presented. At the 6.65 tesla operating field the variation in the saturation magnetization dominates the magnetic tolerance for the iron. 4 refs., 3 figs., 2 tabs.

Kahn, S.A.; Morgan, G.H.

1991-01-01

265

Progress toward a measurement of the electron electrical dipole moment using ultra-cold atoms  

NASA Astrophysics Data System (ADS)

In this thesis, the basic principles of the C, P, T symmetries are introduced and the experiments to measure the electric dipole moment (EDM) are summarized. We propose an experiment to search for the electric dipole moment of the electron using Cs and Rb atoms in 1D optical lattice traps. Our projected sensitivity is 3x10-30 e-cm with an integration time of 12 hours, which is a 500-fold improvement over the current limit. The potential sources of noise and systematic errors in our designed experiment are analyzed. The preliminary test results for charging small ITO coated electric field plates are given, and the designs of a magnetic shielding system and cancellation coils are also described. We trapped the Cs and Rb atoms in the MOT, and launched Cs atoms up 90 cm from the MOT to the center of the measurement chamber while guided by a resonator enhanced 1D optical lattice trap with transport efficiency up to 50%. The 1064 nm wavelength optical lattice is made in a 2 m long build-up cavity of light, and provides a transverse guide depth of up to 250 muK. Before they reach the top of their trajectory, the atoms are stopped and cooled by optical molasses, becoming trapped in the 1D lattice. We also demonstrate multiple launches of Cs atoms to the trap.

Fang, Fang

266

Effects of magnetic dipole-dipole interactions in atomic Bose-Einstein condensates with tunable s-wave interactions  

NASA Astrophysics Data System (ADS)

The s-wave interaction is usually the dominant form of interactions in atomic Bose-Einstein condensates (BECs). Recently, Feshbach resonances have been employed to reduce the strength of the s-wave interaction in many atomic species. This opens the possibilities to study magnetic dipole-dipole interactions (MDDIs) in BECs, where the novel physics resulting from long-range and anisotropic dipolar interactions can be explored. Using a variational method, we study the effect of MDDIs on the statics and dynamics of atomic BECs with tunable s-wave interactions for a variety of species, including both nonalkali metals with large magnetic dipole moments (52Cr, 164Dy, 168Er) and alkali metals (with much smaller magnetic dipole moments). A parameter of magnetic Feshbach resonances, ?dd,max, is used to quantitatively indicate the feasibility of experimentally observing MDDI effects in different atomic species. We find that strong MDDI effects should be observable in both in-trap and time-of-flight behaviors, not only for the strongly magnetic dipolar species but also for the alkali-metal BECs of 7Li, 39K, and 133Cs. In addition, we predict several effects which should be experimentally observable. Our results provide a helpful guide for experimentalists to realize and study atomic dipolar quantum gases.

Olson, Abraham J.; Whitenack, Daniel L.; Chen, Yong P.

2013-10-01

267

Magnetic and Electrical Properties.  

National Technical Information Service (NTIS)

The development of controlled growth of monolayers and thin metallic films has led to a number of studies in which the magnetic and electrical properties are modified by interfaces. The thrust of his paper is to consider cases where the property modificat...

M. B. Brodsky J. E. Mattson

1989-01-01

268

Nb/sub 3/Sn dipole magnet reacted after winding  

SciTech Connect

A 5 cm bore dia., 1-m-long dipole model magnet was constructed by winding un-reacted cable, followed by reaction and epoxy-impregnation. Experience and test results are described on the 1.7 mm dia. internal-tin wire, the eleven-strand flattened cable, fiberglass insulation, and construction of the magnet. Each half of the magnet has two double-pancake-type windings that were reacted in a single operation. The two double-pancakes were then separately vacuum impregnated after soldering the flexible Nb-Ti leads to the Nb/sub 3/Sn conductors. No iron flux return yoke was used. In initial tests a central field of 8.0 T was reached at 4.4 K. However, evidence from training behavior, and 1.8 K tests indicate that premature quenching, rather than critical current of the cable, limited the field intensity. The magnet was reassembled and more rigidly clamped; additional test results are reported.

Taylor, C.; Scanlan, R.; Peters, C.; Wolgast, R.; Gilbert, W.; Hassenzahl, W.; Meuser, R.; Rechen, J.

1984-09-01

269

The permanent electric dipole moment and hyperfine interactions in platinum monofluoride, PtF.  

PubMed

The [11.9]? = 3/2 ? X (2)?(3/2)(0,0) and (1,0) bands of platinum monofluoride, PtF, have been recorded field-free and in the presence of a static electric field. The (19)F(I = 1/2) and (195)Pt(I = 1/2) magnetic hyperfine interactions have been analyzed and compared with predicted values obtained using atomic information and a proposed molecular orbital correlation diagram. The optical Stark shifts were analyzed to produce the permanent electric dipole moments, ?(el), of 2.47(11)D and 3.42(6)D for the [11.9]? = 3/2 and X (2)?(3/2)states, respectively. The observed trend in ?(el) for the PtX (X = C,N,O,S and F) series is discussed and a comparison with IrF made. PMID:22894350

Qin, Chengbing; Zhang, Ruohan; Wang, Fang; Steimle, Timothy C

2012-08-01

270

Correct use of the Gordon decomposition in the calculation of nucleon magnetic dipole moments  

SciTech Connect

We perform the calculation of the nucleon dipole magnetic moment in full detail using the Gordon decomposition of the free quark current. This calculation has become necessary because of frequent misuse of the Gordon decomposition by some authors in computing the nucleon dipole magnetic moment.

Mekhfi, Mustapha [International Center for Theoretical Physics, Trieste, Italy and Departement de Physique, Universite Es-senia, 31100 Oran (Algeria)

2008-11-15

271

Design and end chamfer simulation of PEFP beam line curved dipole magnets  

Microsoft Academic Search

The design, fabrication and field measurement of 11 DC curved dipole magnets for the PEFP Beam Line have been completed. In this paper, a design method for a complex end chamfer using OPERA-3D is proposed. The conventional method for estimating chamfer shape is extended and applied to a curved dipole magnet by a coordinate transformation. Using the interface with CAD

Ying-Shun Zhu; Mei Yang; Zhuo Zhang; Wan Chen; Bao-Gui Yin; Cai-Tu Shi; Wen Kang

2011-01-01

272

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 (d{yields}{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 d{yields}{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 d{yields}{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_equal}1.7 GeV, physical volume V{approx_equal}(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, from which we obtain the bound |d{yields}{sub N}|(less-or-similar sign)0.02e-{theta}-fm. Satisfactory results for the magnetic and electric form factors of the proton and neutron are also obtained and presented.

Berruto, F.; Soni, A. [High Energy Theory Group, Brookhaven National Laboratory, Upton, New York 11973 (United States); Blum, T. [RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973 (United States); Physics Department, University of Connecticut, Storrs, Connecticut 06269-3046 (United States); Orginos, K. [Department of Physics, College of William and Mary, P.O. Box 8795, Williamsburg, Virginia 23187-8795 (United States); Jefferson Lab, MS 12H2, 12000 Jefferson Avenue, Newport News, Virginia 23606 (United States)

2006-03-01

273

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

274

Prospects for an electron electric-dipole-moment search with ferroelectric (Eu,Ba)TiO{sub 3} ceramics  

SciTech Connect

We propose to use ferroelectric (Eu,Ba)TiO{sub 3} ceramics just above their magnetic ordering temperature for a sensitive electron electric-dipole-moment search. We have synthesized a number of such ceramics with various europium concentrations and measured their properties relevant for such a search: permeability, magnetization noise, and ferroelectric hysteresis loops. We also identify and estimate the likely systematics: the magnetoelectric effect, hysteresis-loop heating, and ferroelectric relaxation currents. Our measurements and estimates indicate that a search for the electron electric dipole moment with Eu{sub 0.5}Ba{sub 0.5}TiO{sub 3} could lead to an order of magnitude improvement on the current best limit, if the systematic effects can be controlled.

Sushkov, A. O.; Eckel, S.; Lamoreaux, S. K. [Yale University, Department of Physics, P. O. Box 208120, New Haven, Connecticut 06520-8120 (United States)

2010-02-15

275

Electric dipolar Kondo effect emerging from a vibrating magnetic ion.  

PubMed

When a magnetic ion vibrates in a metal, it inevitably introduces a new channel of hybridization with conduction electrons, and in general, the vibrating ion induces an electric dipole moment. In such a situation, we find that magnetic and nonmagnetic Kondo effects alternatively occur due to the screening of the spin moment and electric dipole moment of the vibrating ion. In particular, the electric dipolar two-channel Kondo effect is found to occur for a weak Coulomb interaction. We also show that a magnetically robust heavy-electron state appears near the fixed point of the electric dipolar two-channel Kondo effect. We believe that the vibrating magnetic ion opens a new door in Kondo physics. PMID:23004326

Hotta, Takashi; Ueda, Kazuo

2012-06-15

276

Electric-dipole-induced spin resonance in quantum dots  

NASA Astrophysics Data System (ADS)

An alternating electric field, applied to a quantum dot, couples to the electron spin via the spin-orbit interaction. We analyze different types of spin-orbit coupling known in the literature and find two efficient mechanisms of spin control in quantum dots. The linear in momentum Dresselhaus and Rashba spin-orbit couplings give rise to a fully transverse effective magnetic field in the presence of a Zeeman splitting at lowest order in the spin-orbit interaction. The cubic in momentum Dresselhaus terms are efficient in a quantum dot with anharmonic confining potential and give rise to a spin-electric coupling proportional to the orbital magnetic field. We derive an effective spin Hamiltonian, which can be used to implement spin manipulation on a time scale of 10ns with the current experimental setups.

Golovach, Vitaly N.; Borhani, Massoud; Loss, Daniel

2006-10-01

277

Resistively-tapered-dipole electric-field probes up to 40 GHz  

Microsoft Academic Search

An electric-field probe for use as a transfer standard at frequencies up to 40 GHz is developed. The lower frequency cutoff is below 1 MHz. The design is based on the resistively tapered dipole (RTD) probes developed for frequencies up to 18 GHz. Those probes used 8-mm tapered dipoles. In this study, 6-mm, 4-mm, and 2-mm dipoles are used to

J. Randa; M. Kanda; R. D. Orr

1991-01-01

278

Design of a model dipole magnet for the SSC High Energy Booster  

SciTech Connect

A superconducting model dipole magnet has been designed to serve as a vehicle in an R D program to develop a dipole magnet for potential use in the SSC High Energy Booster. The objective has been to use the Brookhaven, National Laboratory (BNL) and Fermi National Accelerator Laboratory (FNAL) 50 mm aperture dipole designs to the maximum possible extent for design of a dipole magnet with the same size aperture and a field intensity of 6.67 T. Objectives of this program have also included an evaluation of magnet cross section designs which provides in margin and includes a field quality iteration on BNL and FNAL dipole designs. In this paper the 2D magnetic and mechanical design of the cold mass in conceptual and detail form is presented.

Hassan, N.; Couzens, K.; Dwyer, S.; Jaisle, A.; Jayakumar, R.; Krishnamurthy, S.; Mihelic, R.; Phillips, S.; Puri, R.K.; Sarna, K.; Snitchler, G.; Venkatraman, V.

1993-04-01

279

Design of a model dipole magnet for the SSC High Energy Booster  

SciTech Connect

A superconducting model dipole magnet has been designed to serve as a vehicle in an R&D program to develop a dipole magnet for potential use in the SSC High Energy Booster. The objective has been to use the Brookhaven, National Laboratory (BNL) and Fermi National Accelerator Laboratory (FNAL) 50 mm aperture dipole designs to the maximum possible extent for design of a dipole magnet with the same size aperture and a field intensity of 6.67 T. Objectives of this program have also included an evaluation of magnet cross section designs which provides in margin and includes a field quality iteration on BNL and FNAL dipole designs. In this paper the 2D magnetic and mechanical design of the cold mass in conceptual and detail form is presented.

Hassan, N.; Couzens, K.; Dwyer, S.; Jaisle, A.; Jayakumar, R.; Krishnamurthy, S.; Mihelic, R.; Phillips, S.; Puri, R.K.; Sarna, K.; Snitchler, G.; Venkatraman, V.

1993-04-01

280

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

281

Contamination of dark matter experiments from atmospheric magnetic dipoles  

NASA Astrophysics Data System (ADS)

Dark matter collisions with heavy nuclei (Xe, Ge, Si, Na) may produce recoils observable at direct-search experiments. Given that some of these experiments are yielding conflicting information, however, it is worth asking if physics other than dark matter may produce similar nuclear recoils. We examine under what conditions an atmospherically produced neutral particle with a relatively large magnetic dipole moment could fake a dark matter signal. We argue that a very definite flux could explain the signals seen at DAMA/LIBRA, CDMS/Si and CoGeNT consistently with the bounds from XENON100 and CDMS/Ge. To explore the plausibility of this scenario, we discuss a concrete model with 10–50 MeV sterile neutrinos that was recently proposed to explain the LSND and MiniBooNE anomalies.

Bueno, A.; Masip, M.; Sánchez-Lucas, P.; Setzer, N.

2013-10-01

282

Confinement of electron plasma by levitating dipole magnet  

SciTech Connect

A recent experiment on the Ring Trap 1 device has demonstrated long-term (exceeding 300 s) confinement of non-neutral (pure electron) plasma in a dipole magnetic field; particles diffuse inward, steepening the density gradient and self-organizing into a stable vortex structure [Z. Yoshida et al., Phys. Rev. Lett. 104, 235004 (2010)]. In this study, the internal structures of the plasma are experimentally investigated, and it is shown that the observations are consistent with rigidly rotating charged particle clump. The radial profiles of electrostatic potential and electron density consistently show that the drift velocity has homogeneous angular frequency in the confinement region. The electrostatic fluctuations also rotate rigidly with a phase velocity that agrees with the drift velocity. The magnetospheric system should have a wide application in confining single-species and even multiple-species charged particles.

Saitoh, H.; Yoshida, Z.; Morikawa, J.; Yano, Y.; Hayashi, H.; Mizushima, T.; Kawai, Y.; Kobayashi, M.; Mikami, H. [Department of Advanced Energy, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan)

2010-11-15

283

An experimental search for the electron Electric Dipole Moment in Gadolinium Gallium Garnet  

NASA Astrophysics Data System (ADS)

A discovery of a permanent electric dipole moment of the electron (eEDM) would provide crucial information about the nature of T-violation and imply new sources of CP-violation beyond the Standard Model. While the leading experimental technique used to measure EDM is based on the nuclear magnetic resonance, we are pursuing research that would improve the present experimental limit of the eEDM using a new technique in solid-state systems at low temperatures. The experiment uses a paramagnetic insulator Gadolinium Gallium Garnet with a large magnetic response. The presence of the eEDM leads to a finite magnetization when the garnet sample is subjected to a strong electric field. The resulting magnetization can be measured using the Superconducting Quantum Interference Device (SQUID) as a sensitive magnetometer. In this talk, we will discuss the progress to control the systematic effects and improve the sensitivity. The major efforts include the design and implementation of a 24-bit data acquisition system with ultra-low level of channel crosstalk, and the control of the high voltage drift from the supply. With these considerable progresses, we report our first background-free experimental limit of the eEDM on the order of 10-24 e.cm .

Kim, Young Jin; Liu, Chen-Yu

2011-04-01

284

Measurement of the zero-field magnetic dipole moment of magnetizable colloidal silica spheres  

Microsoft Academic Search

The magnetic properties of dispersions of magnetic silica microspheres have been investigated by measuring the magnetization curves and the complex magnetic susceptibility as a function of frequency and field amplitude. The silica spheres appear to have a net permanent magnetic dipole moment, even in zero field, which is increased significantly after a temporary exposure of the silica colloids to a

E. M. Claesson; B. H. Erné; I. A. Bakelaar; B. W. M. Kuipers; A. P. Philipse

2007-01-01

285

Model dependence of the {sup 2}H electric dipole moment  

SciTech Connect

Background: Direct measurement of the electric dipole moment (EDM) of the neutron is in the future; measurement of a nuclear EDM may well come first. The deuteron is one nucleus for which exact model calculations are feasible. Purpose: We explore the model dependence of deuteron EDM calculations. Methods: Using a separable potential formulation of the Hamiltonian, we examine the sensitivity of the deuteron EDM to variation in the nucleon-nucleon interaction. We write the EDM as the sum of two terms, the first depending on the target wave function with plane-wave intermediate states, and the second depending on intermediate multiple scattering in the {sup 3}P{sub 1} channel, the latter being sensitive to the off-shell behavior of the {sup 3}P{sub 1} amplitude. Results: We compare the full calculation with the plane-wave approximation result, examine the tensor force contribution to the model results, and explore the effect of short-range repulsion found in realistic, contemporary potential models of the deuteron. Conclusions: Because one-pion exchange dominates the EDM calculation, separable potential model calculations will provide an adequate description of the {sup 2}H EDM until such time as a measurement better than 10% is obtained.

Afnan, I. R.; Gibson, B. F. [School of Chemical and Physical Sciences Flinders University, GPO Box 2100, Adelaide 5001 (Australia); Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2010-12-15

286

Atomic electric dipole moments: The Schiff theorem and its corrections  

SciTech Connect

Searches for the permanent electric dipole moments (EDMs) of diamagnetic atoms provide powerful probes of CP-violating hadronic and semileptonic interactions. The theoretical interpretation of such experiments, however, requires careful implementation of a well-known theorem by Schiff that implies a vanishing net EDM for an atom built entirely from pointlike, nonrelativistic constituents that interact only electrostatically. Any experimental observation of a nonzero atomic EDM would result from corrections to the pointlike, nonrelativistic, electrostatic assumption. We reformulate Schiff's theorem at the operator level and delineate the electronic and nuclear operators whose atomic matrix elements generate corrections to 'Schiff screening'. We obtain a form for the operator responsible for the leading correction associated with finite nuclear size - the so-called Schiff moment operator - and observe that it differs from the corresponding operator used in previous Schiff moment computations. We show that the more general Schiff moment operator reduces to the previously employed operator only under certain approximations that are not generally justified. We also identify other corrections to Schiff screening that may not be included properly in previous theoretical treatments. We discuss practical considerations for obtaining a complete computation of corrections to Schiff screening in atomic EDM calculations.

Liu, C.-P. [T-16, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Theory Group, Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); Ramsey-Musolf, M. J. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125 (United States); Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Haxton, W. C. [Institute for Nuclear Theory and Department of Physics, University of Washington, Box 351550, Seattle, Washington 98195-1550 (United States); Timmermans, R. G. E.; Dieperink, A. E. L. [Theory Group, Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands)

2007-09-15

287

Refined representations of the horizontal electric components of the normal field of a high-frequency horizontal electric dipole  

NASA Astrophysics Data System (ADS)

Among the components of normal dipole fields useful in high-frequency electric prospecting, the electric components E and E y of the normal field of the horizontal electric dipole are considerably complicated in structure. By checking these values by means of computer mathematics in combination with the development of the classical (dynamical) theory of interference soundings, the above expressions alluded to in geophysical literature were shown to contain considerable errors. The present paper is devoted to this question.

Petrukhin, B. P.

2009-09-01

288

Magnetic dipole moment of 127Sb and 129Sb by nuclear magnetic resonance on oriented nuclei  

Microsoft Academic Search

A series of low temperature nuclear orientation (LTNO) experiments has been initiated to measure accurately ground-state magnetic dipole moments of a sequence of odd-proton antimony isotopes up to the neutron shell closure at N=82 using the sensitive technique of nuclear magnetic resonance on oriented nuclei (NMR\\/ON). The main aim of this investigation is to clarify the single-particle+collective core coupling mechanism

M. Lindroos; M. Booth; D. Doran; Y. Koh; I. Oliveira; J. Rikovska; P. Richards; N. J. Stone; M. Veskovic; D. Zákoucký; B. Fogelberg

1996-01-01

289

Induced Current on a Long Wire Due to a Vertical Electric Dipole Above Dissipative Ground.  

National Technical Information Service (NTIS)

A closed form expression for the induced current along an infinitely long wire due to a distant vertical electric dipole is found. The dipole and the wire are situated above but near a dissipative ground half space. The wire is assumed to be thin but of f...

A. A. Aburwein

1986-01-01

290

A Closed-Form Formula for Magnetic Dipole Localization by Measurement of Its Magnetic Field and Spatial Gradients  

Microsoft Academic Search

This paper presents a simple algorithm and a compact sensor for localization of a magnetic dipole. First, we derive an explicit localization formula, where the dipole position, irrespective of its posture, is directly reconstructed from the magnetic field and its spatial gradient tensor. Then, we develop a sensor unit consisting of three orthogonal loop coils, three orthogonal planar gradiometers, and

Takaaki Nara; Satoshi Suzuki; Shigeru Ando

2006-01-01

291

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

292

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

293

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

294

Longitudinal Zeeman slowers based on permanent magnetic dipoles  

Microsoft Academic Search

Longitudinal Zeeman slowers composed of arrays of compact discrete neodymium magnets are proposed. The general properties of these slowers, as well as specific designs of short spin-flip Zeeman slowers for Sr and Rb atoms are described. The advantages of these slowers are their simplicity, low cost and absence of consumed electrical power and corresponding water cooling. The smoothness of the

Yuri B. Ovchinnikov

2011-01-01

295

Longitudinal Zeeman slowers based on permanent magnetic dipoles  

Microsoft Academic Search

Longitudinal Zeeman slowers composed of arrays of compact discrete neodymium magnets are proposed. The general properties of these slowers, as well as specific designs of short spin-flip Zeeman slowers for Sr and Rb atoms are described. The advantages of these slowers are their simplicity, low cost and absence of consumed electrical power and corresponding water cooling. The smoothness of the

Yuri B. Ovchinnikov

296

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

297

Intrinsic magnetic Field of Titan Upper limit to the dipole moment  

NASA Astrophysics Data System (ADS)

Titan is embedded in the Saturnian corotating magnetosphere with its orbit lying in the equatorial plane at radius of 20 Saturn radii. The interaction of Titan with this flowing magnetospheric plasma is complex due to the time variation of external conditions and the physics of the interaction with the neutral atmosphere and the ionosphere. A search for any intrinsic magnetic field of Titan must be carried out at low altitudes, where the complexities of the interaction are minimized. Large scale magnetic fields are observed below Titan's ionopause and these fields change both magnitude and orientation at low altitudes. The variability of these fields suggests that external fields and ionospheric currents contribute to the field seen at low altitudes, but if the interior of Titan is electrically conducting the radial component of the field should be least affected by them. Thus the radial component of the magnetometer data between 1100 km and 950 km (periapsis) are studied to determine how much of these fields may be due to an intrinsic dipole moment. By combining data at polar regions and equatorial regions, the dipole moments aligned in three Cartesian axes (g10, g11, h11) are inverted from the data. Pass to pass consistencies of the dipole moments allow us to estimate an upper limit of the intrinsic field. The probable error of the mean of the g10 term is sufficiently high that this value is consistent with zero, but the other two components may be statistically different than zero. The upper limit to the magnetic moment from these data is about 1.2 nT Rt 3.

Wei, H.; Russell, C. T.; Dougherty, M. K.; Neubauer, F. M.; Bertucci, C.; Ma, Y. J.

2007-05-01

298

Charged Lepton Electric Dipole Moment Enhancement in the Lorentz Violated Extension of the Standard Model  

NASA Astrophysics Data System (ADS)

We consider the Lorentz violated extension of the standard model. In this framework, there are terms that explicitly violate CP-symmetry. We examine the CPT-even d??-term to find the electric dipole moment of charged leptons. We show that the form factors besides the momentum transfer, depend on a new Lorentz-scalar, constructing by d?? and the four momenta of the lepton, as well. Such an energy dependence of the electric dipole form factor leads to an enhancement of the lepton electric dipole moment at high energy, even at the zero momentum transfer. We show that at {\\vert d}/{\\vert p2m^2l ˜ 1} the electric dipole moment of the charged lepton can be as large as 10-14e cm.

Haghighat, M.; Motie, I.; Rezaei, Z.

2013-09-01

299

Permanent dipole magnets for the 8 GeV transfer line at FNAL  

SciTech Connect

The transfer line that will serve to transport 8 GeV protons from the Booster to the new Fermilab Main Injector has been built using permanent magnets. A total of 46 horizontal bend dipoles and 5 vertical bend dipoles were built for this beamline; 67 gradient magnets were also built. The magnets were built using magnetized strontium ferrite bricks. Thermal compensation of these bricks was effected by use of a nickel-iron alloy. The dipole magnets were built with a mean integrated strength of 0.56954 T-m, and an rms spread of 0.06%. The magnets were thermally cycled from 20{degrees}C to 0{degrees}C to condition the ferrite against irreversible thermal losses, and the compensation was measured with a flipcoil. The magnet strength was adjusted by varying the number of bricks installed at the magnet ends. Details of the assembly process and a summary of magnetic measurements are presented here.

Glass, H.D.; Brown, B.C.; Foster, G.W.; Fowler, W.B.; Haggard, J.E. [and others

1997-06-01

300

On field line resonances of hydromagnetic Alfven waves in dipole magnetic field  

SciTech Connect

Using the dipole magnetic field model, we have developed the theory of field line resonances of hydromagnetic Alfven waves in general magnetic field geometries. In this model, the Alfven speed thus varies both perpendicular and parallel to the magnetic field. Specifically, it is found that field line resonances do persist in the dipole model. The corresponding singular solutions near the resonant field lines as well as the natural definition of standing shear Alfven eigenfunctions have also been systematically derived. 11 refs.

Chen, Liu; Cowley, S.C.

1989-07-01

301

The magnetic dipole moment of the 150 keV state of 177 Lu  

Microsoft Academic Search

The magnetic dipole interaction of the 150 keV state of177Lu in an environment of metallic ytterbium has been investigated by time-differential perturbed angular correlation experiments. The measurements were performed in an external magnetic field of 0.4 T at room temperature. Two independent measurements at different ?-? cascades give the same Larmor precession frequency. From the weighted average the magnetic dipole

G. Netz; H. Daum; W. Prieske; T. Thiel; E. Gerdau

1977-01-01

302

Mechanical design of the 2D cross-section of the SSC collider dipole magnet  

Microsoft Academic Search

The authors describe the mechanical design of the two-dimensional cross section of the baseline collider dipole magnet for the Superconducting Super Collider. The components described are the collar and yoke laminations and the cold mass shell. The 50-mm-aperture collider dipole magnet uses stainless-steel collars to position the conductors at the locations specified by the magnetic design and to prestress the

J. Strait; J. Kerby; R. Bossert; J. Carson; G. Spigo; J. R. Turner

1991-01-01

303

Design and analysis of the SSC (Superconducting Super Collider) dipole magnet suspension system  

SciTech Connect

The design of the suspension system for Superconducting Super Collider (SSC) dipole magnets has been driven by rigorous thermal and structural requirements. The current system, designed to meet those requirements, represents a significant departure from previous superconducting magnet suspension system designs. This paper will present a summary of the design and analysis of the vertical and lateral suspension as well as the axial anchor system employed in SSC dipole magnets. 5 refs., 9 figs., 4 tabs.

Nicol, T.H.; Niemann, R.C.; Gonczy, J.D.

1989-03-01

304

Electric dipoles and phase stability in nematic liquid crystals  

Microsoft Academic Search

A theory for the nematic-isotropic (N-I) phase transition of prolate uniaxial molecules with longitudinal dipole moments is presented. The theory is based on the variational cluster expansion, truncated after the two-molecule term, and is implemented for polar hard spherocylinders with and without attractions, and for polar linear arrays of Lennard-Jones interactions centre. We find that the dipole interactions substantially shift

A. G. Vanakaras; D. J. Photinos

1995-01-01

305

Atomic electric-dipole moments from Higgs-boson-mediated interactions  

Microsoft Academic Search

Electric-dipole moments of paramagnetic atoms can provide important insights into a unique kind of CP violation involving Higgs-boson-mediated interactions between leptons and hadrons. We report a limit for the coupling constant of such an interaction by combining the results of our relativistic many-body calculations and experimental data on the electric-dipole moment of atomic thallium. The importance of electron correlation in

B. K. Sahoo; B. P. Das; Rajat K. Chaudhuri; Debashis Mukherjee; E. P. Venugopal

2008-01-01

306

A superconducting dipole magnet for the CFFF MHD facility at the University of Tennessee Space Institute  

Microsoft Academic Search

The paper describes a superconducting dipole magnet for the CFFF MHD. The design of the MHD system consisting of the superconducting magnet, magnet cryostat, a helium refrigerator, and instrumentation are discussed, noting that the magnet will have an on-axis peak field of 6 T and an MHD channel warm aperture of 80 cm diameter at the MHD channel inlet. The

S.-T. Wang; L. R. Turner; R. C. Niemann; L. Genens; W. Pelczarski; J. Gonczy; J. Hoffman; K. Mataya; H. Ludwig; S.-H. Kim

1979-01-01

307

Feasibility study of a 3He-magnetometer for neutron electric dipole moment experiments  

NASA Astrophysics Data System (ADS)

We report on a 3He-magnetometer capable of detecting tiny magnetic field fluctuations of less than 10-14 T in experiments for measuring the electric dipole moment (EDM) of the neutron. It is based on the Ramsey technique of separated oscillating fields and uses nuclear spin-polarized 3He gas which is stored in two vessels of /V~=10 l in a sandwich-type arrangement around the storage bottle for ultra-cold neutrons (UCN). The gas is polarized by means of optical pumping in a separate, small discharge cell at pressures around 0.5 mbar and is then expanded into the actual magnetometer volume. To detect the polarization of 3He gas at the end of the storage cycle the gas is pumped out by means of an oil-diffusion pump and compressed again into the discharge cell where optical detection of nuclear polarization is used.

Borisov, Y.; Heil, W.; Leduc, M.; Lobashev, V.; Otten, E. W.; Sobolev, Y.

2000-02-01

308

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

309

Electrical field control of interface magnetic anisotropy  

NASA Astrophysics Data System (ADS)

The interface magnetic anisotropy of ferromagnetic metals comes from the spin-orbit interaction. By explicitly taking into account the interaction between the symmetry-broken interface potential and the spin-dependent electric dipoles of the Bloch states, we find that the interface spin-orbit coupling can be modeled by the Rashba spin-orbit Hamiltonian (RSOH). Due to the presence of the RSOH, the spin up and down states of the ferromagnet are spin mixed at the interface. Among other consequences, the RSOH induces a perpendicular surface magnetic anisotropy whose magnitude is comparable to the observed values in transition metals. When an external electric field is applied across the interface, the induced screening potential modifies the RSOH and thus the perpendicular anisotropy can be manipulated. Our calculated results are in agreement with the experiments [1]. [4pt] [1] Endo et al., Appl. Phys. Lett. 96, 212503 (2010); T. Nozaki et al, Appl. Phys. Lett. 96, 022506 (2010).

Xu, Lei; Zhang, Shufeng

2011-03-01

310

Electric field control of interface magnetic anisotropy  

NASA Astrophysics Data System (ADS)

The interface magnetic anisotropy of ferromagnetic metals comes from the spin-orbit interaction. But unlike the semiconductor heterostructures, the strong electron screening would make the Rashba spin-orbit coupling (RSOC) localized within the election screening length at metallic interface. Now by explicitly taking into account the interaction between the symmetry-broken interface potential and the spin-dependent electric dipoles of the Bloch states, we find that this interaction may generate a RSOC, which is much stronger than the direct Pauli spin-orbit coupling. Due to the presence of the RSOC, the spin up and down states of the ferromagnet are spin mixed at the interface. Among other consequences, the RSOC induces a perpendicular surface magnetic anisotropy whose magnitude is comparable to the observed values in transition metals. When we apply an external electric field across the interface, the induced screening potential modifies the RSOC and thus the perpendicular anisotropy can be manipulated.

Xu, Lei; Zhang, Shufeng

2011-10-01

311

Nb3Sn accelerator magnet technology scale up using cos-theta dipole coils  

SciTech Connect

Fermilab is working on the development of Nb{sub 3}Sn accelerator magnets using shell-type dipole coils and the wind-and-react method. As a part of the first phase of technology development, Fermilab built and tested six 1 m long dipole model magnets and several dipole mirror configurations. The last three dipoles and two mirrors reached their design fields of 10-11 T. The technology scale up phase has started by building 2 m and 4 m dipole coils and testing them in a mirror configuration in which one of the two coils is replaced by a half-cylinder made of low carbon steel. This approach allows for shorter fabrication times and extensive instrumentation preserving almost the same level of magnetic field and Lorentz forces in the coils as in a complete dipole model magnet. This paper presents details on the 2 m (HFDM07) and 4 m long (HFDM08) Nb{sub 3}Sn dipole mirror magnet design and fabrication technology, as well as the magnet test results which are compared with 1 m long models.

Nobrega, F.; Andreev, N.; Ambrosio, G.; Barzi, E.; Bossert, R.; Carcagno, R.; Chlachidze, G.; Feher, S.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; /Fermilab

2007-06-01

312

Finite-element structural analysis of the 10 m long dipole prototype magnet for the LHC  

Microsoft Academic Search

In the framework of the R&D program for the LHC (Large Hadron Collider) superconducting magnets, a series of dipole prototypes, manufactured by European firms, will be placed in a test cell of the LHC machine to be tested in the second part of 1992. The design of the cross-section of the full length dipole prototype is a natural evolution from

M. Bona; D. Perini

1992-01-01

313

Effects of the Dipole Tilt on Dayside Magnetic Reconnection in the Earth's Magnetosphere for Northward IMF  

NASA Astrophysics Data System (ADS)

Magnetic reconnection at the dayside magnetopause are dominantly affected by the relative orientation of the magnetic fields in the magnetosheath and magnetosphere, the relative perpendicular velocities of field lines both before and after reconnection, and the location of the minimum geomagnetic field. We have performed a high-resolution and time-dependent three dimensional MHD simulation of interaction between the solar wind and the Earth's magnetosphere when the dipole tilt, and By and Bz components of the IMF are simultaneously included in the whole volume of the simulation box. In the recent study of Park, K.S. et al. (2006) found that for positive dipole tilt (northern hemisphere is summer) and southward IMF (Bz = 5 nT, By = 5nT), the reconnection site shifts sunward and equatorward in the summer hemisphere, and moves tailward and away from equator in the winter hemisphere. The dipole tilt creates asymmetry that strongly affects the direction of the plasma flow due to reconnection. Moreover, the electric field in the northern "reconnection" region (antiparallel region) is 50% larger than that at the magnetic equator and twice that at the subsolar point. In present study, for the case of positive dipole tilt, and during the northward IMF (Bz = 5 nT, By = 5nT), magnetic reconnection occurs at high latitudes in the northern dusk due to antiparallel field condition in the summer hemisphere for By > 0 and creates open field lines. The open field lines which are generated in the dusk sector and their feet are on the northern ionosphere, move from dusk to dawn in the dayside magnetopause and then come back to dusk in the tail. Tail reconnection successively occurs in the slant and elevated plasma sheet. The polar cap potential in dusk cell is larger than that the dawn cell in summer hemisphere. Moreover three-cell pattern appears in the northern ionosphere. On the other hand, the negative potential is comparable to the positive potential in winter hemisphere and the distorted three-cell pattern appears in the southern ionosphere. The open-closed boundary in the winter hemisphere appears at higher latitude than that in the summer hemisphere.

Park, K.; Ogino, T.

2006-12-01

314

Comparative anatomy of dipole magnets or the magnet designer's coloring book  

SciTech Connect

A collection of dipole magnet cross sections is presented together with an indication of how they are related geometrically. The relationships indicated do not necessarily imply the actual path of evolutionary development. Brief consideration is given to magnets of higher multipole order, i.e., quadrupole magnets, etc.). The magnets under consideration have currents parallel to the axis except at the ends, and are long. The relationship between current distribution and magnetic field is essentially two-dimensional. The coils are usually surrounded by an iron yoke, but the emphasis is on conductor-dominated configurations capable of producing a rather uniform magnetic field in the aperture; the iron usually has a small effect.

Meuser, R.B.

1983-04-01

315

Electric dipole moments and polarizability in the quark-diquark model of the neutron  

SciTech Connect

For a bound state internal wave function respecting parity symmetry, it can be rigorously argued that the mean electric dipole moment must be strictly zero. Thus, both the neutron, viewed as a bound state of three quarks, and the water molecule, viewed as a bound state of ten electrons, two protons, and an oxygen nucleus, have zero mean electric dipole moments. Yet, the water molecules are said to have a nonzero dipole moment strength d=e{Lambda} with {Lambda}{sub H{sub 2O{approx_equal}}}0.385 A. The neutron may also be said to have an electric dipole moment strength with {Lambda}{sub neutron{approx_equal}}0.612 fm. The neutron analysis can be made experimentally consistent, if one employs a quark-diquark model of neutron structure.

Srivastava, Y. N. [Physics Department, University of Perugia, Via A. Pascoli, 06123 Perugia (Italy); Physics Department, Northeastern University, Boston, Massachusetts 02115 (United States); INFN, Sezione di Perugia, Via A. Pascoli, 06123 Perugia (Italy); Widom, A.; Swain, J. [Physics Department, Northeastern University, Boston, Massachusetts 02115 (United States); Panella, O. [INFN, Sezione di Perugia, Via A. Pascoli, 06123 Perugia (Italy)

2010-11-01

316

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

317

Stochastic dynamics of electric dipole in external electric fields: A perturbed nonlinear pendulum approach  

NASA Astrophysics Data System (ADS)

The motion of a dipole in external electric fields is considered in the framework of nonlinear pendulum dynamics. A stochastic layer is formed near the separatrix of the dipole pendulum in a restoring static electric field under the periodic perturbation by plane-polarized electric fields. The width of the stochastic layer depends on the direction of the forcing field variation, and this width can be evaluated as a function of perturbation frequency, amplitude, and duration. A numerical simulation of the approximate stochastic layer width of a perturbed pendulum yields a multi-peak frequency spectrum. It is described well enough at high perturbation amplitudes by an analytical estimation based on the separatrix map with an introduced expression of the most effective perturbation phase. The difference in the fractal dimensions of the phase spaces calculated geometrically and using the time-delay reconstruction is attributed to the predominant development of periodic and chaotic orbits, respectively. The correlation of the stochastic layer width with the phase space fractal dimensions is discussed.

Kapranov, Sergey V.; Kouzaev, Guennadi A.

2013-06-01

318

Magnetic force acting on a magnetic dipole over a superconducting thin film  

SciTech Connect

The magnetostatic interaction energy and corresponding magnetic force acting on a magnetic point dipole placed above a type-II thin superconducting film in the mixed state with a single vortex are calculated using electromagnetics coupled with the London theory of superconductivity. If a vortex is trapped by a circular defect of radius {ital b}{lt}{Lambda}, the magnetic forces, caused by the vortex, differ from the results of free from defect pinning by the factor (1{minus}{ital b}/{Lambda}), where {Lambda} is the effective penetration depth. The possibility of formation of the vortex in the thin film only in the field of the magnetic point dipole is investigated. The critical position of the dipole for creating the first vortex under the electromagnetic pinning of a circular defect and that position in the absence of defect pinning are obtained for comparison. In particular, in the limit of {ital a}/{Lambda}{gt}1, where {ital a} is the separation between the dipole and the thin film, the only difference between two results is in the cutoff length, i.e., in the case of a circular defect the only difference in the critical position calculation is the cutoff at radius {ital b} rather than at coherence length {xi}. The pinning force of a single vortex by a circular defect is also calculated. Further, we investigate the conditions of the vortex creation for various cases (including the first, second, and third vortices) for a free of pinning center in the examining region. It is found that the creation of a new single vortex in the thin film causes an abrupt change in vertical levitation force: the force changed discontinuously. {copyright} {ital 1996 The American Physical Society.}

Wei, J.C. [Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu, Taiwan, Republic of (China); Chen, J.L. [Department of Electro-Physics, National Chiao-Tung University, Hsinchu, Taiwan, Republic of (China); Horng, L. [Department of Physics, National Changhua University of Education, Changhua, Taiwan, Republic of (China); Yang, T.J. [Department of Electro-Physics, National Chiao-Tung University, Hsinchu, Taiwan, Republic of (China)

1996-12-01

319

Magnetic designs of 2-in-1 Nb3Sn dipole magnets for VLHC  

Microsoft Academic Search

The paper presents the results of a conceptual design study of double aperture Nb3Sn dipole magnets for VLHC based on the cos-theta and common coil geometry with cold and warm iron yoke. The study included an optimization of the iron yoke geometry to achieve the maximum transfer function, small fringe fields and low-order field harmonics as well as an optimization

Vadim V. Kashikhin; Alexander V. Zlobin

2001-01-01

320

Frequency response study of dipole magnet cold mass for the Superconducting Super Collider.  

National Technical Information Service (NTIS)

This paper describes the technique for calculating the dynamic response of the Superconducting Super Collider (SSC) dipole magnet cold mass. Dynamic motion specification and beam location stability of the cold mass are not available at the present time. D...

K. K. Leung T. Nicol

1991-01-01

321

R Measurements with ISR in BaBar - Hadronic Part of Muon Magnetic Dipole Moment.  

National Technical Information Service (NTIS)

Recent measurements of the quantity R, the ratio of annihilation o , including those following Initial State Radiation, are discussed in the context of the hadronic part of i, the muon magnetic dipole moment. The data indicate that more precise theoretica...

P. Taras

2006-01-01

322

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

323

Configuration of Particle Drain for the High Energy Charged Particles in the Magnetic Dipole Field.  

National Technical Information Service (NTIS)

The boundary of particle leakage from the magnetic dipole trap depending on the value of adiabatic parameter is investigated. By trajectory computation a generalized analytical expression is determined for the shape of particle drain by x less than or equ...

I. V. Amirkhanov E. P. Zhidkov V. V. Ignatov A. N. Il'ina V. D. Il'in

1987-01-01

324

The electric dipole moment of rhodopsin solubilized in Triton X-100.  

PubMed Central

The electric dipole moment of solubilized rhodopsin was determined with dielectric dispersion measurements. Rhodopsin was extracted from disc membranes of cattle rod outer segments with the nonionic detergent Triton X-100. The dipole moment of rhodopsin at its isoionic point in the detergent micelle is 720 D (150 charge-A). This value is comparable to dipole moments of nonmembrane proteins, especially those which tend to aggregate or polymerize. Flash irradiation of the rhodopsin results in an increase in the dipole moment of about 25 D (5 charge-A). The light-induced increase in dipole moment appears to be composed of two parts--a faster component related to a change in the number of protons bound by rhodopsin and a slower component apparently independent of the change in proton binding.

Petersen, D C; Cone, R A

1975-01-01

325

Design study of a superconducting dipole model magnet for the Large Hadron Collider  

Microsoft Academic Search

A design study of a high-field superconducting dipole magnet for the LHC (Large Hadron Collider) project has been carried out in cooperation between CERN and KEK. The objective is to develop a 1-m twin-aperture dipole model magnet based on double shell coil design with a fully symmetric split collaring structure. Development of superconducting cable with high keystone angle is a

Hiromi Hirabayashi; Akira Yamamoto; Shuma Kawabata; Giorgio Brianti; Daniel Leroy; Romeo Perin

1991-01-01

326

Industrial development and engineering of a 1 meter twin-aperture superconducting dipole magnet for LHC  

Microsoft Academic Search

The authors discuss the technical solutions and experiences obtained related to the choice of construction materials and manufacturing procedures for a 1-m twin-aperture superconducting dipole magnet for the LHC (Large Hadron Collider). It is pointed out that the production development and engineering for a 10-T twin-aperture dipole magnet require sophisticated solutions for numerous problems. These problems concern the insulation and

H. J. Israel; H. Boschman; R. L. Dubbeldam

1992-01-01

327

Performance of the Main Dipole Magnet Circuits of the LHC during Commissioning  

Microsoft Academic Search

During hardware commissioning of the Large Hadron Collider (LHC), 8 main dipole circuits are tested at 1.9 K and up to their nominal current. Each dipole circuit contains 154 magnets of 15 m length, and has a total stored energy of up to 1.3 GJ. All magnets are wound from Nb-Ti superconducting Rutherford cables, and contain heaters to quickly force

A. Verweij; V. Baggiolini; A. Ballarino; B. Bellesia; Frederick Bordry; A. Cantone; M. Casas Lino; A. Castaneda Serra; C. Castillo Trello; N Catalan-Lasheras; Z. Charifoulline; G. Coelingh; K. Dahlerup-Petersen; G. D'Angelo; R. Denz; S. Feher; R. Flora; M. Gruwe; V. Kain; B. Khomenko; G. Kirby; A. MacPherson; A. Marqueta Barbero; K.-H. Mess; M. Modena; R. Mompo; V. Montabonnet; S le Naour; D Nisbet; V Parma; M Pojer; L Ponce; A Raimondo; S Redaelli; H Reymond; D Richter; G de Rijk; A Rijllart; I Romera Ramirez; R Saban; S Sanfilippo; R Schmidt; A Siemko; M Solfaroli Camillocci; Y Thurel; H Thiessen; W Venturini-Delsolaro; A Vergara Fernandez; R Wolf; M Zerlauth

2008-01-01

328

Recursive Bayesian Method for Magnetic Dipole Tracking With a Tensor Gradiometer  

Microsoft Academic Search

Previous magnetic dipole localization algorithms using gradient data attempt to find the position of the magnetic source at the measurement time only. Based on the direct inversion of the magnetic gradient tensor, these methods provide results that can be highly sensitive to temporal noise in data. To avoid a temporally scattered solution, a recursive approach is proposed that is promising

Marius Birsan

2011-01-01

329

The search for electric dipole moments of light ions in storage rings  

NASA Astrophysics Data System (ADS)

The Standard Model (SM) of Particle Physics is not capable of accounting for the apparent matter-antimatter asymmetry of our universe. Physics beyond the SM is required and is searched for by (i) employing highest energies (e.g., at LHC), and (ii) striving for ultimate precision and sensitivity (e.g., in the search for electric dipole moments (EDMs)). Permanent EDMs of particles violate both time reversal (T) and parity (P) invariance, and are via the CPT-theorem also CP-violating. Finding an EDM would be a strong indication for physics beyond the SM, and reducing upper limits further provides crucial tests for any corresponding theoretical model, e.g., SUSY. Direct searches for proton and deuteron EDMs bear the potential to reach sensitivities beyond 10?29 e·cm. For an all-electric proton storage ring, this goal is pursued by the US-based srEDM collaboration [1], while the newly founded Jülich-based JEDI collaboration [2] is pursuing an approach using a combined electric-magnetic lattice, which shall provide access to the EDMs of protons, deuterons, and 3He ions in the same machine. In addition, JEDI has recently proposed making a direct measurement of the proton and/or deuteron EDM at COSY using resonant techniques involving Wien filters.

Rathmann, Frank; Saleev, Artem; Nikolaev, N. N.; Jedi; srEdm collaborations

2013-07-01

330

Ultrafast coherent control of giant oscillating molecular dipoles in the presence of static electric fields  

NASA Astrophysics Data System (ADS)

We propose a scheme to generate electric dipole moments in homonuclear molecular cations by creating, with an ultrashort pump pulse, a quantum superposition of vibrational states on electronic states strongly perturbed by very strong static electric fields. By field-induced molecular stabilization, the dipoles can reach values as large as 50 Debyes and oscillate on a time-scale comparable to that of the slow vibrational motion. We show that both the electric field and the pump pulse parameters can be used to control the amplitude and period of the oscillation, while preventing the molecule from ionizing or dissociating.

Chang, Bo Y.; Shin, Seokmin; Palacios, Alicia; Martín, Fernando; Sola, Ignacio R.

2013-08-01

331

Low Temperature Heat Transfer Properties of Conventional Electrical Insulation for the Next European Dipole  

Microsoft Academic Search

The heat transfer properties of the fibreglass epoxy resin impregnated electrical insulation of the Next European dipole, known as conventional insulation, has been tested at low temperature. The electrical insulation is made of E-glass fibre with a plain weave and RAL epoxy system 227 (DGEBF epoxy resin and DETD aromatic hardener). The samples have been tested in pressurized superfluid helium

J. Polinski; S. Canfer; G. Ellwood; B. Baudouy

2008-01-01

332

Electromagnetic edge diffraction revisited: the transient field of magnetic dipole sources  

NASA Astrophysics Data System (ADS)

A surprisingly simple exact solution is derived for the transient electromagnetic field scattered by a perfectly conducting half-plane, which is embedded in a uniformly conducting host and energized by a unit step impulse of an arbitrarily oriented magnetic dipole. Despite its simplicity, the model has some relevance for geophysical applications (e.g. mineral exploration), provides insight into the physics of the transient scattering process, and has merits in validating numerical 2.5-D or 3-D codes. The diffraction of electromagnetic waves at a perfectly conducting edge is one of the few vectorial diffraction problems that allows an exact treatment. In the past, attention has been confined to harmonic excitation in a lossless dielectric host, whereas the transient field in a lossy medium has escaped attention. In the quasi-static approximation in particular, this solution turns out to be simple compared to the explicit form of the field using harmonic excitation. However, even the inclusion of displacement currents, which may be necessary when applying transient electromagnetic methods to environmental geophysics, does not lead to complications. The electric field and the time derivative of the magnetic field are given explicitly both in the quasi-static limit and with the inclusion of displacement currents. The late-time behaviour of the field is remarkable: whereas the full-space parts of these fields show the well-known t- 5/2 decay, the diffracted wave emerging from the edge decays only as t- 2 and therefore dominates the field geometry at late × . The appendices briefly treat the quasi-static transient field of a grounded electric dipole and sketch the formal solution for a perfectly conducting half-plane in a layered host.

Weidelt, Peter

2000-06-01

333

Influence of the magnetic dipole interaction on the properties of magnetic vortices in particles of small size  

Microsoft Academic Search

Two type of plaquette systems are proposed for modeling a vortex in an easy-plane two-dimensional Heisenberg ferromagnet with the dipole–dipole interaction of the magnetic moments of the lattice taken into account. The first plaquette describes a system with the boundary spins fixed in the easy plane perpendicular to the “surface” of the magnet, while in the second plaquette the boundary

A. S. Kovalev; J. E. Prilepsky

2004-01-01

334

On the resource evaluation of marine gas hydrate deposits using sea-floor transient electric dipole-dipole methods  

SciTech Connect

Methane hydrates are solid, nonstoichiometric mixtures of water and the gas methane. The depth extent and stability of the hydrate zone is governed by the phase diagram for mixtures of methane and hydrate and determined by ambient pressures and temperatures. The base of the hydrate zone is a phase boundary between solid hydrate and free gas and water. It stands out on seismic sections as a bright reflection. The diffuse upper boundary is not as well marked so that the total mass of hydrate is not determined easily by seismic alone. The addition of electrical data, collected with a seafloor transient electric dipole-dipole system, can aid in the evaluation of the resource. Two exploration scenarios are investigated through numerical modeling. In the first, a very simple example illustrating some of the fundamental characteristics of the electrical response, most of the properties of the section including the probable, regional thickness of the hydrate zone (200 m) are assumed known from seismic and spot drilling. In the second example, less information is assumed available a priori and the complementary electrical survey is required to find both the thickness and the hydrate content in a hydrate zone about 200 m thick beneath the sea floor containing 20 and 40% hydrate in the available pore space, respectively. A linear eigenfunction analysis reveals that for these two models, the total mass of hydrate, the product of hydrate content and thickness, may be estimated to an accuracy of about 3{epsilon}% given measurements of traveltime to an accuracy of {epsilon}% over a range of separations from 100 to 1300 m. Based on these data, the author suggests that the value of {epsilon} may be of the order of 3%.

Edwards, R.N. [Univ. of Toronto, Ontario (Canada). Dept. of Physics

1997-01-01

335

Model SSC (Superconducting Super Collider) dipole magnet cryostat assembly at Fermilab  

SciTech Connect

The Superconducting Super Collider (SSC) magnet development program includes the design, fabrication and testing of full length model dipole magnets. A result of the program has been the development of a magnet cryostat design. The cryostat subsystems consist of cold mass connection-slide, suspension, thermal shields, insulation, vacuum vessel and interconnections. Design details are presented along with model magnet production experience. 6 refs., 13 figs.

Niemann, R.C.

1989-03-01

336

Electric dipole moment of the top quark within an effective theory  

NASA Astrophysics Data System (ADS)

Using the effective Lagrangian approach, we develope the trilinear contributions originated in the dimension-six electroweak invariants O~W = (1/3)?ijkWi?vWjv?Wk?? and O~WB = (1/2)B~??Wc???†?c?, and then we insert the corresponding vertices in a one-loop ttV diagram, with V off-shell, generating the structure of the electric dipole moment. Using a nonlinear gauge, we prove that the results are gauge independent. Finally, we present the analytic expressions for the electric dipole form factors originated in each invariant introduced.

Novales-Sánchez, H.; Toscano, J. J.

2009-04-01

337

Electron in the Field of a Molecule with an Electric Dipole Moment  

SciTech Connect

In solving the eigenvalue wave equation, we relax the usual diagonal constraint on its matrix representation by allowing it to be tridiagonal. This results in a larger representation space that incorporates an analytic solution for the noncentral electric dipole pole potential cos{theta}/r{sup 2}, which was believed not to belong to the class of exactly solvable potentials. Consequently, we obtain closed form solution of the time-independent Schroedinger equation for an electron in the field of a molecule treated as a point electric dipole.

Alhaidari, A. D. [Shura Council, Riyadh 11212 (Saudi Arabia); Bahlouli, H. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2008-03-21

338

Double-core-polarization contribution to atomic parity-nonconservation and electric-dipole-moment calculations  

NASA Astrophysics Data System (ADS)

We present a detailed study of the effect of double core polarization (the polarization of core electrons due to the simultaneous action of the electric dipole and parity-violating weak fields) for amplitudes of the ss and sd parity-nonconserving transitions in Rb, Cs, Ba+, La2+, Tl, Fr, Ra+, Ac2+, and Th3+ as well as electron electric-dipole-moment enhancement factors for the ground states of the above neutral atoms and Au. This effect is quite large and has the potential to resolve some disagreement between calculations in the literature. It also has significant consequences for the use of experimental data in the accuracy analysis.

Roberts, B. M.; Dzuba, V. A.; Flambaum, V. V.

2013-10-01

339

Proposal for a cryogenic magnetic field measurement system for SSC dipole magnets  

SciTech Connect

This proposal describes the research and development required, and the subsequent fabrication of, a system capable of making integrated magnetic multipole measurements of cryogenic 40-mm-bore SSC dipole magnets utilizing a cryogenic probe. Our experience and some preliminary studies indicate that it is highly unlikely that a 16-meter-long probe can be fabricated that will have a twist below several milliradians at cryogenic temperatures. We would anticipate a twist of several milliradians just as a result of cooldown stresses. Consequently, this proposal describes a segmented 16-meter-long probe, for which we intend to calibrate the phase of each segment to within 0.1 milliradians. The data for all segments will be acquired simultaneously, and integrated data will be generated from the vector sums of the individual segments. The calibration techniques and instrumentation required to implement this system will be described. The duration of an integral measurement at one current is expected to be under 10 seconds. The system is based on an extrapolation of the techniques used at LBL to measure cryogenic 1-meter models of SSC magnets with a cryogenic probe. It should be noted that the expansion of the dipole bore from 40 to 50 mm may make a warm-finger device practical at a cost of approximately one quarter of the cryogenic probe. A warm quadrupole measurement system can be based upon the same principles. 5 refs., 9 figs., 1 tab.

Green, M.I.; Hansen, L.

1991-03-01

340

Search for a Permanent Electric Dipole Moment on MERCURY-199 Atoms as a Test of Time Reversal Symmetry  

NASA Astrophysics Data System (ADS)

Optically pumped atomic oscillators driven with a modulated light source have been used to measure the Permanent Electric Dipole Moment (PEDM) of the ^{199}Hg atom. A nonzero PEDM on the ground state of ^{199} Hg would be a direct violation of time reversal symmetry. The measurement was obtained by searching for a relative shift in the resonance frequency of the processing nuclear magnetic moments when an externally applied electric field was reversed relative to an externally applied magnetic field. The null result, d(^{199} Hg) = (.3 +/- 5.7 +/- 5.0) times 10 ^{-28} ecdotcm, represents nearly a factor of 15 improvement over previous ^{199}Hg measurements, and a factor of 25 improvement in statistical uncertainty. When combined with theoretical calculations, the result sets stringent limits on possible sources of time reversal symmetry violation in atomic systems.

Jacobs, James Patrick

341

Analysis of a cross flow cooling scheme for an SSC collider dipole magnet  

NASA Astrophysics Data System (ADS)

An analysis of a scheme to induce transverse flow in the annulus between the beam tube and coils of an SSC dipole magnet is presented. Transverse, or cross flow, cooling is used to limit the temperature rise from heat sources in the beam tube. These sources include synchrotron radiation during accelerator operation, and heat leak from the magnetic measuring device inserted in the beam tube during verification and acceptance testing of Collider Dipole Magnets. A model which describes the flow distribution within a dipole, and subsequent temperature rise of the helium, is developed and solved. Pressure drops and transverse flow rates are presented as functions of parameters which describes the relative impedance of the various flow paths through the magnet. Results show that substantial reductions in coil temperature rise occur for very small increases in overall pressure drop, for the proper set of flow path impedances.

Peck, Scott D.

1994-07-01

342

Magnetic measurements on the ring dipoles and quadrupoles for the Los Alamos proton storage ring  

NASA Astrophysics Data System (ADS)

This paper discusses magnetic measurements and shimming performed on the ring dipoles and quadrupoles for the Los Alamos Proton Storage Ring (PSR). For the dipoles, point-by-point field maps were obtained using a search coil that could be scanned over a three-dimensional grid. By appropriate machining of removable end blocks, all magnet lengths were adjusted to within 0.01% of a nominal value and all integrated multipoles were set within tolerance. Integrated fields of 20 PSR quadrupoles were measured using a rotating Morgan Coil and a digital spectrum analyzer. The magnets were shimmed to specifications by adjusting steel bolts threaded through the field clamps.

Schermer, R. I.; Blind, B.; Jason, A. J.; Sawyer, G. A.

343

Frequency generation by a magnetic vortex-antivortex dipole in spin-polarized current  

Microsoft Academic Search

We study the dynamics of a vortex-antivortex (VA) dipole which may be generated due to spin-polarized current flowing through a magnetic element. We employ the Landau-Lifshitz equation with a Slonczewski spin-torque term with in-plane polarization. We establish that the vortex dipole is set in steady-state rotational motion. The frequency of rotation is due to two independent forces: the interaction between

Stavros Komineas

2012-01-01

344

Wideband planar open-sleeve dipole on magnetic dielectric material based EBG substrate  

Microsoft Academic Search

Open-sleeve dipoles are widely used antennas because they have several parameters that can be adjust to achieve wide range of operating bandwidth. In this paper, an end-loaded planar open-sleeve dipole (ELPOSD) with a magnetic dielectric material based planar EBG substrate is investigated. With S11 < -10 dB, the ELPOSD has a bandwidth of 5.15-10 GHz and the broadband gains precede

Chaoyuan Ding; Chengli Ruan; Lin Peng; Xuncai Yin

2009-01-01

345

Performance of six 4. 5 m SSC (Superconducting Super Collider) dipole model magnets  

Microsoft Academic Search

Six 4.5 m long dipole models for the proposed Superconducting Super Collider have been successfully tested. The magnets are cold-iron (and cold bore) 1-in-1 dipoles, wound with current density-graded high homogeneity NbTi cable in a two-layer cos theta coil of 40 mm inner diameter. The coil is prestressed by 15 mm wide stainless steel collars, and mounted in a circular,

E. Willen; P. Dahl; J. Cottingham; M. Garber; A. Ghosh; C. Goodzeit; A. Green; J. Herrera; S. Kahn; E. Kelly

1986-01-01

346

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

347

A superconducting dipole magnet system for the MHD facility at Univ. of Tennessee Space Institute  

Microsoft Academic Search

A superconducting dipole magnet system for use in the MHD facility at the University of Tennessee Space Institute (UTSI) has been designed by Argonne National Laboratory. The system consists of the magnet and its cryostat, a helium liquefier\\/refrigeration facility, a helium gas handling system, apparatus for cryogenic transfer and storage and an integrated control system including computer data acquisition system,

S.-T. Wang; L. R. Turner; R. C. Niemann; L. Genens; M. S. Srinivasan

1978-01-01

348

US SCMS dipole magnet system for the bypass loop of the U-25 MHD facility  

Microsoft Academic Search

The Argonne National Laboratory is responsible for designing and constructing a superconducting dipole magnet system for use in the bypass loop of the U-25 MHD facility in Moscow. The system consists of the magnet and its cryostat, a helium refrigerator\\/liquefier facility, associated cryogenic and storage apparatus, power supply, the necessary vacuum and gas handling systems and an integrated control system.

R. C. Niemann; S. T. Wang; W. J. Pelczarski

1976-01-01

349

Design and Test of a Nb3Sn Subscale Dipole Magnet for Training Studies  

SciTech Connect

As part of a collaboration between CEA/Saclay and the Superconducting Magnet Group at LBNL, a subscale dipole structure has been developed to study training in Nb3Sn coils under variable pre-stress conditions. This design is derived from the LBNL Subscale Magnet and relies on the use of identical Nb{sub 3}Sn racetrack coils. Whereas the original LBNL subscale magnet was in a dual bore 'common-coil' configuration, the new subscale dipole magnet (SD) is assembled as a single bore dipole made of two superposed racetrack coils. The dipole is supported by a new mechanical structure developed to withstand the horizontal and axial Lorentz forces and capable of applying variable vertical, horizontal and axial preload. The magnet was tested at LBNL as part of a series of training studies aiming at understanding of the relation between pre-stress and magnet performance. Particular attention is given to the coil ends where the magnetic field peaks and stress conditions are the least understood. After a description of SD design, assembly, cool-down and tests results are reported and compared with the computations of the OPERA3D and ANSYS magnetic and mechanical models.

Felice, Helene; Caspi, Shlomo; Dietderich, Daniel R.; Felice, Helene; Ferracin, Paolo; Gourlay, Steve A.; Hafalia, Aurelo R.; Lietzke, Alan F.; Mailfert, Alain; Sabbi, GainLuca; Vedrine, Pierre

2007-06-01

350

Tests of 40 mm SSC dipole model magnets with vertically split yokes.  

National Technical Information Service (NTIS)

Several 1 meter long, 40 mm aperture model SSC dipole magnets with vertically split yokes have been built and tested at Fermilab. In addition to the yoke design, these magnets were used to evaluate several variants of the collet clamps which apply prestre...

W. Koska R. Bossert K. J. Coulter S. Delchamps S. Gourlay

1991-01-01

351

SPIN AND MAGNETIC DIPOLE MOMENT OF 2.6HR Mn⁵⁶  

Microsoft Academic Search

Progress tc date on atomic beam magnetic resonance measurements of the ; nuclear spin of Mn⁵⁶ is reported. Tentative results indicate a spin of 1 = ; 3\\/sub n\\/ and a magnetic dipole moment mu = 3.53 plus or minus 0.01 nan. ; (W.D.M.);

W. J. Childs; L. S. Goodman; L. J. Kieffer

1958-01-01

352

Measurements of the magnetic dipole moments of the antiproton and the Sigma hyperon  

Microsoft Academic Search

The fine-structure splittings in atoms formed by stopping antiprotons in Pb and U and Sigma- hyperons in Pb and Pt have been measured. Since the fine structure is produced through the interaction of the magnetic dipole moment of the p¯ or the Sigma- with the Coulomb field of the nucleus, a value for the magnetic moment can be determined from

B. L. Roberts; C. R. Cox; M. Eckhause; J. R. Kane; R. E. Welsh; D. A. Jenkins; W. C. Lam; P. D. Barnes; R. A. Eisenstein; J. Miller; R. B. Sutton; A. R. Kunselman; R. J. Powers; J. D. Fox

1975-01-01

353

Supersymmetric sum rules on magnetic dipole moments of arbitrary-spin particles  

Microsoft Academic Search

We find model independent, exact sum rules valid for any theory with unbroken N = 1 supersymmetry. These sum rules determine the magnetic dipole moments of all particles within a massive N = 1 supermultiplet in terms of a single free parameter. They imply in particular that, when all magnetic-moment matrix elements are diagonal, the gyromagnetic ratio of arbitrary-spin supersymmetric

Sergio Ferrara; Massimo Porrati

1992-01-01

354

Helium pressure rise of superconducting super collider dipole magnets following a quench  

Microsoft Academic Search

A code for simultaneously solving the time-dependent continuity, momentum, and energy equations for helium in flow channels, the heat conduction equation in windings, and the magnet current decay equation has been applied to a full-length superconducting super collider dipole magnet for the extreme case of having helium flow only around the bore tube. Code modifications were made to model a

M. A. Hilal; S. D. Peck; E. A. Ibrahim; V. N. Karpenko; W. R. Hassenzahl

1988-01-01

355

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

Microsoft Academic Search

The design of the SSC (Superconducting Super Collider) dipole magnet cryostat is described, and discussions of the thermal, structural, and dynamic considerations involved in the development of each of the major systems are included. The SSC development program has afforded the opportunity to extend the design of cryostats for superconducting magnets far beyond the state of the art achieved at

T. H. Nicol; Y. P. Tsavalas

1991-01-01

356

A method of obtaining solutions with only positive dipole moments on inversion of satellite magnetic anomalies  

Microsoft Academic Search

A method has been developed to obtain solutions with positive magnetization on inversion of satellite magnetic anomalies. Starting with an initial guess of positive values, the dipole moments are updated through an iterative process under the condition that the calculated fields reproduce the observed anomalies in the sense of least squares. Application of the method is illustrated through inversions of

B. P. Singh; N. Basavaiah; M. Rajaram; G. Geetharamanan

1989-01-01

357

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

358

Updating the neutron electric dipole moment in a fourth generation standard model  

NASA Astrophysics Data System (ADS)

A fourth generation of quarks, if it exists, may provide sufficient CP violation for the baryon asymmetry of the Universe. We estimate the neutron electric dipole moment in the presence of a fourth generation and find it would be dominated by the strange quark chromoelectric dipole moment, assuming it does not get wiped out by a Peccei-Quinn symmetry. Both the three electroweak loop and the two-loop electroweak/one-loop gluonic contributions are considered. With mb', mt' at 500 GeV or so that can be covered at the LHC, and with a Jarlskog CP violation factor that is consistent with hints of New Physics in b?s transitions, the neutron electric dipole moment is found around 10-31ecm, still far below the 10-28ecm reach of the new experiments being planned or under construction.

Hisano, Junji; Hou, Wei-Shu; Xu, Fanrong

2011-11-01

359

A robust limit for the electric dipole moment of the electron  

NASA Astrophysics Data System (ADS)

Electric dipole moments constitute a competitive method to search for new physics, being particularly sensitive to new CP -violating phases. Given the experimental and theoretical progress in this field and more generally in particle physics, the necessity for more reliable bounds than the ones usually employed emerges. We therefore propose an improved extraction of the electric dipole moment of the electron and the relevant coefficient of the electron-nucleon coupling, taking into account theoretical uncertainties and possible cancellations, to be used in model-dependent analyses. Specifically, we obtain at 95% C.L. | d e | ? 0.14 × 10-26 e cm with present data, which is very similar to the bound typically quoted from the YbF molecule, but obtained in a more conservative manner. We examine furthermore in detail the prospects for improvements and derive upper limits for the dipole moments of several paramagnetic systems presently under investigation, i.e. cesium, rubidium and francium.

Jung, Martin

2013-05-01

360

Updating the neutron electric dipole moment in a fourth generation standard model  

SciTech Connect

A fourth generation of quarks, if it exists, may provide sufficient CP violation for the baryon asymmetry of the Universe. We estimate the neutron electric dipole moment in the presence of a fourth generation and find it would be dominated by the strange quark chromoelectric dipole moment, assuming it does not get wiped out by a Peccei-Quinn symmetry. Both the three electroweak loop and the two-loop electroweak/one-loop gluonic contributions are considered. With m{sub b'}, m{sub t'} at 500 GeV or so that can be covered at the LHC, and with a Jarlskog CP violation factor that is consistent with hints of New Physics in b{yields}s transitions, the neutron electric dipole moment is found around 10{sup -31}e cm, still far below the 10{sup -28}e cm reach of the new experiments being planned or under construction.

Hisano, Junji [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); IPMU, TODIAS, University of Tokyo, Kashiwa, 277-8583 (Japan); Hou, Wei-Shu [Department of Physics, National Taiwan University, Taipei, Taiwan 10617 (China); National Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan 10617 (China); Xu Fanrong [Department of Physics, National Taiwan University, Taipei, Taiwan 10617 (China)

2011-11-01

361

Estimation and localization of electrical dipoles in somatosensory evoked potentials  

Microsoft Academic Search

Neuronal currents in the brain produce external magnetic fields and scalp surface potentials that can be measured using magnetoencephalography (MEG) and electroencephalography (EEG), respectively. In the context of the localization of neuronal sources, the forward problem is to determinate the potentials and magnetic fields that result from primary current sources. The inverse problem is to estimate the location of these

Pablo Lecumberri; M. Gomez; A. Malanda; J. Artieda; M. Alegre; I. G. de Gurtubay; M. Valencia; M. Colino

2002-01-01

362

Direct measurement of the nuclear magnetic dipole moment of Ho 165 with the atomic beam magnetic resonance method  

Microsoft Academic Search

With an atomic beam magnetic resonance apparatus four rf transitions between different Zeeman levels of the4I15\\/2 ground state of Ho165 have been measured in an external magnetic field of about 3000 Gauss. The interaction between the nuclear magnetic dipole moment and the external field could be deduced from these measurements. Because the magnetic field was measured by calibration transitions in

R. A. Haberstroh; T. I. Moran; S. Penselin

1972-01-01

363

Electric and Magnetic Forces: Electric Charges  

NSDL National Science Digital Library

Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach.This Science Object is the first of three Science Objects in the Electric and Magnetic Forces SciPack.

National Science Teachers Association (NSTA)

2008-10-30

364

Regular and Chaotic Motion in General Relativity. Case of Magnetized Black Hole and a Massive Magnetic Dipole  

NASA Astrophysics Data System (ADS)

Near a rotating black hole, circular motion of particles, dust grains and complex fluids have been investigated as a model for accretion of gaseous and dusty environment in the toroidal geometry. Here we further discuss, within the framework of general relativity, figures of equilibrium of matter under the influence of combined gravitational and large-scale magnetic fields, assuming that the accreted material acquires a small (but non-vanishing) electric charge due to the interplay of plasma processes and photoionization. We employ different solutions for the central body (magnetized Kerr metric, or a massive magnetic dipole) and we identify the corresponding regions of stability. The action of gravitational and electromagnetic forces jointly determine the regions of stable motion, in particular, whether the halo lobes develop where particles can be captured in permanent circulation around the central body. Therefore, our set-up is relevant in the context of accreting compact objects where the halo motion can describe the overall global motion through corona of an accretion disc or a geometrically thick torus. We also investigate situations when the motion exhibits the onset of chaos. In order to characterize the measure of chaoticness we employ techniques of Poincare surfaces of section and Recurrence plots. Acknowledgments: Czech-US collaboration project (ref. ME09036) and the Czech Science Foundation program (ref. P209/10/P190) are gratefully acknowledged for their continued support.

Karas, Vladimir; Kovar, J.; Kopacek, O.; Kojima, Y.; Slany, P.; Stuchlik, Z.

2012-05-01

365

Transient analysis of the AGS-Booster ring dipole and quadrupole magnet system  

SciTech Connect

A case study has been conducted for the quantitative analysis of the transmission line effects in the Brookhaven AGS Booster ring dipole and quadrupole magnet string. The Booster is a rapid cycling synchrotron (7.5 Hz) which is excited by multiphase rectifier power supplies. A computer model and a simulation program are developed to study the transient current response of the magnet string due to an applied step voltage. To damp out the staircase noise caused by wave reflection during the current ramp, external resistors will be added in parallel with each half dipole magnet and each quadrupole magnet. The system model simulation values are based on the actual magnet parameters, the magnet power supply bus system, and the proposed current ramping rate. The system simulation approach can be applied to a larger system as well, and will be briefly discussed. 5 refs., 7 figs.

Zhang, W.; Soukas, A.V.; Zhang, S.Y.

1991-01-01

366

CP violation and electric dipole moment at low energy ?-pair production  

Microsoft Academic Search

CP violation at low energy is investigated at the ? electromagnetic vertex. High statistics at B-factories, and on top of the ? resonances, allows a detailed investigation of CP-odd observables related to the ?-pair production. The contribution of the tau electric dipole moment is considered in detail. We perform an analysis independent from the high energy data by means of

J. Bernabéu; G. A. González-Sprinberg; J. Vidal

2004-01-01

367

On the Theory of Radiation from a Raised Electric Dipole over an Inhomogeneous Ground Plane.  

National Technical Information Service (NTIS)

The influence of a finite ground plane on the field of a raised electric dipole is considered from an analytical standpoint. The method for evaluating the integrals is discussed briefly and some asymptotic results are given which illustrate the limiting b...

J. R. Wait

1967-01-01

368

Pure Rotational Spectrum and Electric Dipole Moment of CH3D  

Microsoft Academic Search

The pure rotational spectrum of CH3D in the ground vibrational and electronic state has been observed using a far-infrared grating spectrometer. This spectrum is of particular interest because the electric dipole moment ? arises entirely from an isotopic substitution. Ten distinct lines have been observed in the frequency range from 40 to 120 cm?1, and have been identified with the

Irving Ozier; W. Ho; George Birnbaum

1969-01-01

369

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

370

Measurement of the nuclear magnetic dipole moments of 177Hf and 179Hf with the atomic beam magnetic resonance method  

Microsoft Academic Search

The nuclear ground-state magnetic dipole moments of 177Hf and 179Hf have been determined with the atomic beam magnetic resonance method. The results are: muI(177Hf = 0.7836(6)muN, muI(179Hf) = -0.6329(13) muN (uncorrected for diamagnetic shielding).

S. Büttgenbach; M. Herschel; G. Meisel; E. Schrödl; W. Witte

1973-01-01

371

Development of twin aperture dipole magnets for the Large Hadron Collider  

Microsoft Academic Search

A twin aperture dipole magnet has been developed with a feature of symmetric, separate coil\\/collar design in a R&D cooperation between CERN and KEK towards the LHC (Large Hadron Collider) project. The magnet reached 8.1 T at 4.2 K and 9.6 T at 1.8 K in the training test. Development of the magnet and test results are discussed. Design study

Akira Yamamoto; Takakazu Shintomi; Nono Higashi; Hiromi Hirabayashi; Hiroshi Kawamata; Naihao Song; Akio Terashima; Hiroshi Yamaoka; Shuma Kawabata; G. Brianti; J. Buckley; D. Leroy; R. Perin; A. Siemko; L. Walckiers; M. Hirano; T. Origasa; K. Makishima; I. Inoue; M. Ikeda; S. Meguro; M. Kondo

1995-01-01

372

Quench characteristics of 5-cm-aperture, 15-m-long SSC dipole magnet prototypes  

Microsoft Academic Search

The quench performance and ramp rate sensitivity of 18 5-cm-aperture, 15-m-long Superconducting Super Collider (SSC) dipole magnet prototypes are discussed. All the magnets appear to reach a quench plateau near their extrapolated short sample current limit and well in excess of the operating current with very little training. Most of the magnets, however, exhibit a dramatic degradation of their quench

W. Nah; A. Akhmetov; M. Anerella; R. Bossert; T. Bush; J. Carson; R. Coombes; J. Cottingham; S. W. Delchamps; A. Devred; J. Di Marco; G. Ganetis; G. Garber; C. Goodzeit; A. Ghosh; S. Gourlay; A. Greene; R. Gupta; R. Hanft; A. Jain; S. Khan; E. Kelly; W. Koska; M. Kuchnir; J. Kuzminski; M. J. Lamm; P. Mantsch; P. O. Mazur; G. Morgan; J. Muratore; T. Ogitsu; D. Orris; J. Ozelis; T. Peterson; E. G. Pewitt; A. Prodell; M. Puglisi; P. Radusewicz; M. Rehak; E. P. Rohrer; J. Royet; W. Sampson; P. Sanger; R. Scanlan; R. Schermer; R. Shutt; R. Stiening; J. Strait; C. Taylor; R. Thomas; P. Thompson; J. C. Tompkins; J. Turner; M. Wake; P. Wanderer; E. Willen; Y. Yu; J. Zbasnik; Y. Zhao; H. Zheng

1993-01-01

373

Electrical Transport in Metallic Magnetic Multilayers.  

National Technical Information Service (NTIS)

This thesis contains a theoretical study of electrical transport in metallic magnetic multilayers. The resistance of magnetic multilayers drops sharply when the magnetizations of adjacent magnetic layers are aligned by applying an external magnetic field....

C. M. Schep

1997-01-01

374

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

375

On the magnetic dipole moment of the 153 Tb ground state  

Microsoft Academic Search

Temperature dependence of the angular distribution anisotropy of the 212·0 keV gamma-ray following the decay of153Tb oriented in a gadolinium host was measured at temperatures from 16 to 70 mK. Magnetic dipole hyperfine splitting parameter a0 for153Tb(Gd) and magnetic dipole moment of the153Tb ground state were estimated to be ¦a0¦?1·2×10-5 eV and ¦µ¦??3·1 nuclear magnetons, respectively.

I. Procházka; J. Konícek; J. Dupák; M. Finger; M. I. Fominykh; T. I. Kracíková; V. N. Pavlov; M. Petrík; V. M. Tsupko-Sitnikov; J. Muhonen

1981-01-01

376

Electromagnetic field of a vertical electric dipole in the presence of a three-layered region  

Microsoft Academic Search

The electromagnetic field generated by a vertical electric dipole in the air over the surface of a two-layered region is determined for continuous-wave excitation. The region of interest consists of a conductor or dielectric with high permittivity, coated with an electrically thin layer of a dielectric under a half-space of air. Simple explicit formulas are derived for the field at

Ronald W. P. King; Sheldon S. Sandler

1994-01-01

377

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

378

Magnetic dipole hyperfine interactions in {sup 137}Ba{sup +} and the accuracies of the neutral weak interaction matrix elements  

SciTech Connect

The relativistic coupled-cluster method is applied to calculate the magnetic dipole hyperfine constant 'A' of the 6s{sub 1/2}, 6p{sub 1/2}, 6p{sub 3/2}, and 5d{sub 3/2} states of singly ionized barium. After the inclusion of two-body correlation effects into the computation of the hyperfine matrix elements, the accuracy of the obtained values was significantly increased compared to earlier computations. Based on these numbers and earlier calculations of the electric dipole transitions and excitation energies, an estimate for the accuracy of the vertical bar [5p{sup 6}]6s{sub 1/2}>{yields} vertical bar [5p{sup 6}]5d{sub 3/2}> parity-nonconserving electric dipole transition amplitude is carried out. The results suggest that for the first time, to our knowledge, a precision of better than 1% is feasible for this transition amplitude.

Sahoo, Bijaya K.; Gopakumar, Geetha; Chaudhuri, Rajat K.; Das, B.P.; Merlitz, Holger; Mahapatra, Uttam Sinha; Mukherjee, Debashis [Non-Accelerator Particle Physics Group, Indian Institute of Astrophysics, Bangalore 560034 (India); Forschungszentrum Karlsruhe GmbH, Institut fuer Nanotechnologie, Postfach 3640, D-76021 Karlsruhe (Germany); Department of Physical Chemistry, Indian Association for Cultivation of Science, Calcutta 700 032 (India)

2003-10-01

379

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

380

Boosting the directivity of optical antennas with magnetic and electric dipolar resonant particles.  

PubMed

Dielectric particles supporting both magnetic and electric Mie resonances are shown to be able to either reflect or collect the light emitted by a single photon source. An analytical model accurately predicts the scattering behavior of a single dielectric particle electromagnetically coupled to the electric dipole transition moment of a quantum emitter. We derive near field extensions of the Kerker conditions in order to determine the conditions that strongly reduce scattering in either the forward or backward directions. This concept is then employed to design a lossless dielectric collector element whose directivity is boosted by the coherent scattering of both electric and magnetic dipoles. PMID:23037088

Rolly, Brice; Stout, Brian; Bonod, Nicolas

2012-08-27

381

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

382

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

383

Observation of Magnetic Dipole Forbidden Transitions in LHD and Its Application to Burning Plasma Diagnostics  

NASA Astrophysics Data System (ADS)

Magnetic dipole forbidden (M1) transition was studied in large helical device (LHD) and F-, Si- and Ti-like Ml transitions are successfully observed for highly ionized Ar, Kr, Mo and Xe ions. The wavelengths measured in visible range for the heavy elements, which are carefully determined with extremely small uncertainties of 0.02 ~ 0.05 Å as a standard wavelength of usual electric dipole (E1) plasma emissions, are compared with theoretical predictions. The result shows a good agreement with recent Hatree-Fock calculation including semi-empirical adjustment. The M1 intensity for the F-like ions is examined by analyzing the intensity ratio of M1 to E1. Density dependence of the ratio is experimentally verified by comparing with collisional- radiative model calculation on level population. The M1/E1 line ratio for the F-like ions is applied to the ? (He2+) particle diagnostics in ITER, in which a steady-state operation of burning plasmas based on D-T fusion reaction is expected with ? particle heating. Unfortunately, the present estimation suggests a negative result for the ? particle measurement because the ratio is largely enhanced by the collisional excitation with bulk ions due to high ion temperature of ITER of 10 keV as assumed and the resultant effect of the collisional excitation with ? particles becomes less. Meanwhile, the Ml transition, in particular, Ti-like WLIII (W52+) transition (3627 Å) emitted in visible range, is very useful for diagnostics of the impurity behavior and the core plasma parameters in ITER.

Morita, Shigeru; Goto, Motoshi; Katai, Ryuji; Dong, Chunfeng; Sakaue, Hiroyuki; Zhou, Hangyu

2010-06-01

384

Quench antenna and fast-motion investigations during training of a 7T dipole magnet  

SciTech Connect

Equipment was installed to detect fast conductor motion and quench propagation in a 1 meter long superconducting dipole magnet (1) The fast-motion antenna, centered within the bore of the magnet, used three long dipole coils, mounted end-to-end to span the magnet length. Coil signals were nulled against a neighbor to produce low-ripple signals that were sensitive to local flux changes. A low-microphonic signal was used as an event trigger. (2) Nulling improvements were made for the magnet`s coil-imbalance signals for improved cross-correlation information. (3) A quench-propagation antenna was installed to observe current redistribution during quench propagation. It consisted of quadrupole/sextupole coil sets distributed at three axial locations within the bore of the magnet. Signals were interpreted in terms of the radius, angle, orientation, and rate of change of an equivalent dipole. The magnet was cooled to 1.8K to maximize the number of events. Twenty-four fast-motion events occurred before the first quench. The signals were correlated with the magnet-coil imbalance signals. The quench-propagation antenna was installed for all subsequent quenches. Ramp-rate triggered quenches produced adequate signals for analysis, but pole-turn quenches yielded such small signals that angular localization of a quench was not precise.

Lietzke, A.F.; Benjegerdes, R.; Bish, P.; Krywinski, J.; Scanlan, R.; Schmidt, R.; Taylor, C.

1994-10-17

385

Trends in cable magnetization and persistent currents during the production of the main dipoles of the Large Hadron Collider  

Microsoft Academic Search

The production of more than 60% of superconducting cables for the main dipoles of the Large Hadron Collider has been completed. The results of the measurements of cable magnetization and the dependence on the manufacturers are presented. The strand magnetization produces field errors that have been measured in a large number of dipoles (approximately 100 to date) tested in cold

Boris Bellesia; Luca Bottura; Valeria Granata; Sandrine Le Naour; Luc Oberli; Stephane Sanfilippo; Claudio Santoni; Walter Scandale; Nikolai Schwerg; Ezio Todesco; Christine Vollinger

2005-01-01

386

Calculation of the (T,P)-odd electric dipole moment of thallium and cesium  

SciTech Connect

Parity and time invariance violating electric dipole moment of {sup 205}Tl is calculated using the relativistic Hartree-Fock and configuration interaction methods and the many-body perturbation theory. Contributions from the interaction of the electron electric dipole moments with internal electric field and scalar-pseudoscalar electron-nucleon (T,P)-odd interaction are considered. The results are d({sup 205}Tl)=-582(20)d{sub e} or d({sup 205}Tl)=-7.0(2)x10{sup -18}C{sup SP}e cm. Interpretation of the measurements are discussed. The results of similar calculations for {sup 133}Cs are d({sup 133}Cs)=124(4)d{sub e} or d({sup 133}Cs)=0.76(2)x10{sup -18}C{sup SP}e cm.

Dzuba, V. A.; Flambaum, V. V. [School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia)

2009-12-15

387

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

388

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

PubMed

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. PMID:24116780

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

2013-09-24

389

DETECTION OF NONPOLAR IONS IN {sup 2}{Pi}{sub 3/2} STATES BY RADIOASTRONOMY VIA MAGNETIC DIPOLE TRANSITIONS  

SciTech Connect

The possibility of magnetic dipole-induced pure rotational transitions in the interstellar medium is investi- gated for symmetric Hund's case (a) linear molecules, such as H-C{identical_to}C-H{sup +} (X-tilde {sup 2}{Pi}{sub 3/2u}), CO{sub 2} {sup +} (X-tilde {sup 2}{Pi}{sub 3/2g}), H-C{identical_to}C-C{identical_to}C-H{sup +} (X-tilde {sup 2}{Pi}{sub 3/2g}), and N{sub 3} (X-tilde {sup 2}{Pi}{sub 3/2g}). These species lack an electric dipole moment and therefore cannot undergo pure rotational electric dipole transitions. These species can undergo pure rotational transitions via the parallel component of the magnetic dipole operator, however. The transition moments and Einstein A coefficients for the allowed pure rotational transitions are derived for a general Hund's case (a) linear molecule, and tabulated for the examples of H-C{identical_to}C-H{sup +} ({sup 2}{Pi}{sub 3/2u}) and H-C{identical_to}C-C{identical_to}C-H{sup +} ({sup 2}{Pi}{sub 3/2g}). It is found that the rates of emission are comparable to collision rates in interstellar clouds, suggesting that this decay mechanism may be important in simulating rotational population distributions in diffuse clouds and for detecting these molecules by radioastronomy. Expected line positions for the magnetic dipole-allowed R{sub ef} (J) and R{sub fe} (J) transitions of H-C{identical_to}C-H{sup +} ({sup 2}{Pi}{sub 3/2u}), H-C{identical_to}C-C{identical_to}C-H{sup +} ({sup 2}{Pi}{sub 3/2g}), CO{sub 2}{sup +} ({sup 2}{Pi}{sub 3/2g}), and N{sub 3} ({sup 2}{Pi}{sub 3/2g}) are tabulated to assist in their observation by radioastronomy or in the laboratory.

Morse, Michael D. [Department of Chemistry, University of Utah, Salt Lake City, UT 84112 (United States); Maier, John P., E-mail: morse@chem.utah.edu, E-mail: j.p.maier@unibas.ch [Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel (Switzerland)

2011-05-10

390

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

391

Electric dipole moments of impact-excited He atoms  

SciTech Connect

We excited helium atoms using 10--20-keV H{sub 2}{sup +} (D{sub 2}{sup +}) ion impact and investigated the intensity of the {lambda}(4{sup 3}{ital D}-2{sup 3}{ital P})=447 nm line as a function of an electric field {minus}2 kV/cm{approx lt}{ital F}{le}+2 kV/cm applied antiparallel and parallel to the ion beam. The recorded signals were strongly asymmetric with respect to the sign of the electric field. This asymmetry is explained by assuming a coherent excitation of He levels with different angular momenta (4{ital d},4{ital f} and 5{ital f},5{ital g}). These measurements demonstrate that angular momentum coherences of impact-excited states can also be observed in nonhydrogenic systems.

Aynacioglu, A.S.; Heumann, S.; von Oppen, G. (Institut fuer Strahlungs- und Kernphysik, Technische Universitaet Berlin, D-1000 Berlin 12, Federal Republic of Germany (DE))

1990-04-16

392

Field and structural analysis of 56 mm aperture dipole model magnets for the Large Hadron Collider  

Microsoft Academic Search

A new dipole model magnet design has been made with an aperture of 56 mm according to re-optimization of the accelerator design for the Large Hadron Collider (LHC) to be built at CERN, A feature of “symmetric\\/separate collar configuration” in the new design proposed by KEK has been evaluated in terms of field quality and mechanical stability according to the

Naihao Song; Akira Yamamoto; Takakazu Shintomi; Hiromi Hirabayashi; Hiroshi Yamaoka; A. Terashima

1996-01-01

393

Divergent quench velocity expression and 4-cm SSC R D dipole magnets  

SciTech Connect

a quench velocity expression which has a divergent behavior close to the critical current density is reported here. This quench velocity has the same behavior presented by that of the quench velocity measurements made on the 17-m-long, 4-cm-aperture SSC R D dipole magnets which show a clear departure from the expected theoretical adiabatic expression. 8 refs., 1 fig.

Lopez, G.

1991-05-01

394

Unitary model for the ?p???0p reaction and the magnetic dipole moment of the ?+(1232)  

Microsoft Academic Search

photon to the p ! ?N process is exactly satisfied. We study the sensitivity of the p ! ?0p process at higher values of the final photon energy to the ?+(1232) magnetic dipole moment. We compare our results with existing data and give predictions for forthcoming measurements of angular and energy distributions. It is found that the photon asymmetry and

Wen-Tai Chiang; M. Vanderhaeghen; Shin Nan Yang; D. Drechsel

2005-01-01

395

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, Paul [Universite de Montreal, Physique des Particules, Montreal, Quebec, H3C 3J7 (Canada)

2007-02-27

396

Muon anomalous magnetic dipole moment in the minimal supersymmetric standard model  

Microsoft Academic Search

The muon anomalous magnetic dipole moment (MDM) is calculated in the framework of the minimal supersymmetric standard model (MSSM). In this paper, we discuss how the muon MDM depends on the parameters in the MSSM in detail. We show that the contribution of the superparticle loop becomes significant especially when tanbeta is large. Numerically, it becomes of order 10-8-10-9 in

Takeo Moroi

1996-01-01

397

Magnetic dipole moment of the ?+(1232) from the ?p???0p reaction  

Microsoft Academic Search

The p ! ?0p reaction in the ?(1232)-resonance region is investigated as a method to access the ?+(1232) magnetic dipole moment. The calculations are performed within the context of an effective Lagrangian model containing both the ?-resonant mechanism and a background of non-resonant contribu- tions to the p ! ?0p reaction. Results are shown both for existing and forthcoming p

D. Drechsel; M. Vanderhaeghen

2001-01-01

398

Magnetic dipole moments of odd-mass nuclei in the spherical region  

Microsoft Academic Search

The magnetic dipole moments of odd-mass nuclei are calculated and ; compared to the experimental data for nuclei with particles in the 28-126 shells, ; except for the deformed region of 150 less than or equal to A less than or equal ; to 190. The wave functions upon which the calculation is based are admixtures of ; seniority-one wave

N. Freed; L. S. Kisslinger

1961-01-01

399

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

400

Muon magnetic dipole moment and Higgs mass in supersymmetric SU(5) models  

Microsoft Academic Search

We study the muon magnetic dipole moment and the Higgs mass in the framework of the supersymmetric SU(5) models. In this analysis, all the relevant parameters in the Lagrangian are taken to be free; in particular, assumption of the universal scalar mass is not adopted. Negative search for the Higgs boson at the LEP II experiment sets an important constraint on

Motoi Endo; Takeo Moroi

2002-01-01

401

Exotic atom measurements of the magnetic dipole moment of the sigma minus  

Microsoft Academic Search

An experiment performed at the AGS at Brookhaven National Laboratory to measure the magnetic dipole moment of the Sigma- hyperon is described. The results were deduced from the observed fine-structure splitting in the atomic states of Sigma- nucleus. The recently published value is (-1.105+\\/-0.029+\\/-.010) nuclear magnetons.

J. P. Miller; E. J. Austin; F. O'Brien; B. L. Roberts; G. W. Dodson; R. J. Powers; R. B. Sutton; M. Eckhause; P. P. Guss; D. W. Hertzog; D. Joyce; J. R. Kane; W. C. Phillips; W. F. Vulcan; R. E. Welsh; R. J. Whyley; R. G. Winter; A. R. Kunselman

1989-01-01

402

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

403

Transient electromagnetic field of a vertical magnetic dipole on a two-layer conducting Earth  

Microsoft Academic Search

The transient field-frequency domain of magnetic dipole in a two-layered conducting Earth has been studied. It is obtained as a summation of waveguide modes plus contributions from branch cuts in the complex-plane of the longitudinal wave number. Results can be used to evaluate numerical solutions of more complicated modeling algorithms

Samira T. Bishay; Osama M. Abo Seida; Ghada M. Sami

2001-01-01

404

Transient electromagnetic fields of a vertical magnetic dipole on a two-layer earth  

Microsoft Academic Search

The transient fields of a vertical magnetic dipole on a two-layer earth model are expressed in analytical form using two different approaches. In the first, the fields in the time domain are obtained as the inverse Laplace transforms of derived full wave time-harmonic solutions, while in the second, the concept of natural frequencies of the stratified earth is utilized. Comparison

S. F. Mahmoud; A. Z. Botros; J. R. Wait

1979-01-01

405

Kosterlitz-Thouless transition of magnetic dipoles on the two-dimensional plane  

NASA Astrophysics Data System (ADS)

The universality class of a phase transition is often determined by factors like dimensionality and inherent symmetry. We study the magnetic dipole system in which the ground-state symmetry and the underlying lattice structure are coupled to each other in an intricate way. A two-dimensional (2D) square-lattice system of magnetic dipoles undergoes an order-disorder phase transition belonging to the 2D Ising universality class. According to Prakash and Henley [Phys. Rev. BJUPSAU1098-012110.1103/PhysRevB.42.6574 42, 6572 (1990)], this can be related to the fourfold-symmetric ground states, which suggests a similarity to the four-state clock model. Provided that this type of symmetry connection holds true, the magnetic dipoles on a honeycomb lattice, which possess sixfold-symmetric ground states, should exhibit a Kosterlitz-Thouless transition in accordance with the six-state clock model. This is verified through numerical simulations in the present investigation. However, it is pointed out that this symmetry argument does not always apply, which suggests that factors other than symmetry can be decisive for the universality class of the magnetic dipole system.

Baek, Seung Ki; Minnhagen, Petter; Kim, Beom Jun

2011-05-01

406

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

407

Two-dimensional hybrid code simulation of electromagnetic ion cyclotron waves in a dipole magnetic field  

Microsoft Academic Search

Proton temperature anisotropy (T$\\\\perp$p\\/T$\\\\parallel$p > 1) with sufficiently high ?$\\\\parallel$p will drive the electromagnetic ion cyclotron (EMIC) instability. A two-dimensional hybrid code is employed to simulate the EMIC waves in a dipole magnetic field. We initialize the electron-proton plasma such that the MHD equilibrium J × B = ?$\\\\bf\\\

Y. Hu; R. E. Denton

2009-01-01

408

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

409

Field inhomogeneity effect on the quench current of LHC dipole magnets  

NASA Astrophysics Data System (ADS)

The calculation of the maximum field of superconducting magnets is carried out by comparing the cable critical current line (Ic vs B) with the magnet load line. In order to take into account the self field effects in critical current measurements, both the lines commonly refer to the maximum magnetic field at the conductor. In case of dipole magnets for high energy physics applications, in which the cable experiences a strong field inhomogeneity, another criterion (the effective field one) can be adopted, considering the field distribution inside the cable. Furthermore the transition smoothness and the thermal exchange can be considered. The paper describes the results of the calculation obtained for LHC dipoles: the maximum current value comes out to be a little higher (about 3%) if the new criteria are adopted instead of the maximum field criterion.

Fabbricatore, Pasquale; Musenich, Riccardo; Gemme, Gianluca; Parodi, Renzo; Zhang, Bi

1994-07-01

410

Refrigeration options for the Advanced Light Source Superbend Dipole Magnets  

Microsoft Academic Search

The 1.9 GeV Advance Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL) produces photons with a critical energy of about 3.1 kev at each of its thirty-six 1.3 T gradient bending magnets. It is proposed that at three locations around the ring the conventional gradient bending magnets be replaced with superconducting bending magnets with a maximum field of

M. A. Green; E. H. Hoyer; R. D. Schlueter; C. E. Taylor; J. Zbasnik; S. T. Wang

1999-01-01

411

Magnetic dipole moment estimates for an ancient lunar dynamo  

SciTech Connect

The four measured planetary magnetic moments combined with a recent theoretical prediction for dynamo magnetic fields suggest that no dynamo exists in the moon's interior today. For the moon to have had a magnetic moment in the past of sufficient strength to account for at least some of the lunar rock magnetism, the rotation would have been about twenty times faster than it is today and the radius of the fluid, conducting core must have been about 750 km. The argument depends on the validity of the Busse solution to the validity of the MHD problem of planetary dynamos.

Anderson, K.A.

1983-02-15

412

Low Temperature Heat Transfer Properties of Conventional Electrical Insulation for the Next European Dipole  

NASA Astrophysics Data System (ADS)

The heat transfer properties of the fibreglass epoxy resin impregnated electrical insulation of the Next European dipole, known as conventional insulation, has been tested at low temperature. The electrical insulation is made of E-glass fibre with a plain weave and RAL epoxy system 227 (DGEBF epoxy resin and DETD aromatic hardener). The samples have been tested in pressurized superfluid helium (He II) where heat is applied perpendicularly to the fibres between 1.55 K to 2.05 K. Overall thermal resistance is determined with temperature and compared with other electrical insulation systems.

Polinski, J.; Canfer, S.; Ellwood, G.; Baudouy, B.

2008-03-01

413

Electrical properties of metal-molecule-silicon structures with varying molecular backbones, dipoles, and atomic tethers  

NASA Astrophysics Data System (ADS)

We present the results of an extensive experimental investigation of metal-monolayer-silicon junctions. By varying the molecular dipole, the molecular backbone, the Si-molecule linkage, and the Si-doping, we indentified critical features that determine the electrical transport and injection properties of the junctions. Two basic structures were used. One is an enclosed planar structure in which an organic monolayer is directly assembled on silicon and contacted with evaporated silver. The other was made via Flip Chip Lamination, a novel approach that relies on the formation of monolayers on a gold surface first, which enables the study of a wider range of molecular layers on silicon of very high-quality. Two charge transport regimes dominate: (1) a Schottky barrier limited regime where the molecular dipole results in silicon band bending at the junction interface, and (2) a tunneling regime where the molecular dipole creates a small local electric field that screens the electrical transport. Transition Voltage spectroscopy was used to identify electrical differences between ?-conjugated and alkyl backbones attributed to the extended ?-delocalization and variations due to the chemical nature of Si-atom linkage.

Richter, Curt A.; Gergel-Hackett, Nadine; Coll, Mariona; Hacker, Christina A.

2011-03-01

414

Magnetic dipole moment of the Delta(1232) in chiral perturbation theory  

Microsoft Academic Search

The magnetic dipole moment of the Delta(1232) is calculated in the framework of manifestly Lorentz-invariant baryon chiral perturbation theory in combination with the extended on-mass-shell renormalization scheme. As in the case of the nucleon, at leading order both isoscalar and isovector anomalous magnetic moments are given in terms of two low-energy constants. In contrast to the nucleon case, at next-to-leading

C. Hacker; N. Wies; J. Gegelia; S. Scherer

2006-01-01

415

The sign of the magnetic dipole moment of the ground state of 122 I  

Microsoft Academic Search

The sign of the nuclear magnetic dipole moment of the ground state of122I has been determined to be positive using a novel experimental technique. The technique investigates the asymmetry of positron\\u000a emission by detecting the 511 keV gamma-rays produced on the annihilation of the positrons. The method would appear to have\\u000a general validity for studying the sign of the magnetic

C. J. Ashworth; T. L. Shaw; J. Rikovska; N. J. Stone; V. R. Green; P. M. Walker; B. D. D. Singleton; I. S. Grant

1988-01-01

416

The sign of the magnetic dipole moment of the ground state of122I  

Microsoft Academic Search

The sign of the nuclear magnetic dipole moment of the ground state of122I has been determined to be positive using a novel experimental technique. The technique investigates the asymmetry of positron emission by detecting the 511 keV gamma-rays produced on the annihilation of the positrons. The method would appear to have general validity for studying the sign of the magnetic

C. J. Ashworth; T. L. Shaw; J. Rikovska; N. J. Stone; V. R. Green; P. M. Walker; B. D. D. Singleton; I. S. Grant

1988-01-01

417

Magnetic measurement system for harmonic analysis of LBL SSC model dipoles and quadrupoles  

Microsoft Academic Search

Specialized hardware and software have been developed to facilitate harmonic error analysis measurements of one-meter-long Superconducting Super Collider (SSC) model dipole and quadrupole magnets. Cold bore measurements feature cryogenic search-coil arrays with high buckling ratios that also have sufficient sensitivity to make room-temperature measurements at the low magnet currents of --10 A. Three sets of search coils allow measurements of

M. I. Green; P. J. Barale; W. S. Gilbert; W. V. Hessenzahl; D. H. Nelson; C. E. Taylor; N. J. Travis; D. A. Van Dyke

1988-01-01

418

Magnetic measurement system for harmonic analysis of LBL SSC (Superconducting Super Collider) model dipoles and quadrupoles  

Microsoft Academic Search

Specialized hardware and software have been developed to facilitate harmonic error analysis measurements of one-meter-long Superconducting Super Collider (SSC) model dipole and quadrupole magnets. Cold bore measurements feature cryogenic search-coil arrays with high bucking ratios that also have sufficient sensitivity to make room-temperature measurements at the low magnet currents of approx.10 A. Three sets of search coils allow measurements of

M. I. Green; P. J. Barale; W. S. Gilbert; W. V. Hassenzahl; D. H. Nelson; C. E. Taylor; N. J. Travis; D. A. Van Dyke

1987-01-01

419

Corrector magnets: Combined structural analysis of collier 50 mm aperture ordered wound dipoles interior section  

SciTech Connect

The 50mm aperture prototype collider ordered wound dipole connector magnets have been modeled with finite element techniques considering the individual and combined load cases of the preloading from keys, cooldown to 4 K and the effect of magnetic forces during energizing. Results of the analysis are presented as longitudinal, transverse and shear stresses for the ordered wound coils and as maximum von Mises stress for the carbon steel outer laminations, the stainless steel inner lamination, and the carbon steel keys.

Tran, Vu H.

1993-04-01

420

Evolution of plasma sheet electron pitch angle distribution by whistler-mode chorus waves in non-dipole magnetic fields: Comparisons with the use of dipole model  

NASA Astrophysics Data System (ADS)

We present a detailed numerical study on the effects of non-dipole magnetic field on Earth's plasma sheet electron distribution and its implication for diffuse auroral precipitation. Use of the modified bounce-averaged Fokker-Planck equation for 2-D non-dipole magnetic fields suggests that we can follow the numerical schemes used for a dipole field but should evaluate bounce-averaged diffusion coefficients and bounce period related terms in non-dipole magnetic fields. Focusing on nightside whistler-mode chorus waves at L=6 within the Dungey magnetic models, we calculate and make comparison of the bounce-averaged diffusion coefficients in each case. Adoption of the Alternative Direction Implicit scheme to numerically solve 2-D Fokker-Planck diffusion equation gives the result that chorus driven resonant scattering diffuses the plasma sheet electrons much faster into loss cone and also expands to lower energies and higher equatorial pitch angles when the southward interplanetary magnetic field increases in the Dungey magnetic model. Furthermore, we find that changes in diffusion coefficients are the dominant factor responsible for variations in modeled temporal evolution of plasma sheet electron distribution. Our study demonstrates that the effects of realistic ambient magnetic fields are required to be incorporated into both evaluation of resonant diffusion coefficients and calculation of Fokker-Planck diffusion equation to quantitatively understand the evolution of plasma sheet electron distribution and the occurrence of diffuse aurora, in particular at L>5 during geomagnetically disturbed periods when the ambient magnetic field considerably deviates from a magnetic dipole.

Ma, Q.; Ni, B.; Tao, X.; Thorne, R. M.

2011-12-01

421

Magnetic field angle changes during manufacture and testing of SSC collider dipoles  

SciTech Connect

Measurements of the magnetic field angle along the length of collider dipole magnets are discussed. These superconducting magnets were built at Fermilab for the Superconducting Super Collider (SSC) by Fermilab and General Dynamics personnel. These measurements were made at four stages in the assembly and test sequence. The data show-that changes can occur both during installation in the cryostat and as a result of cold testing. Most of the changes during installation are correlated with the welding of the tie bar restraints. But the changes observed as a result of the cold testing can be attributed to changes in the magnetization of the iron laminations.

Kuchnir, M.; Bleadon, M.; Delchamps, S.W.; Schmidt, E.; Bossert, R.; Carson, J.; Gourlay, S.; Hanft, R.; Koska, W.; Lamm, M.J.; Mazur, P.O.; Orris, D.; Ozelis, J.; Strait, J.; Wake, M. [Fermi National Accelerator Lab., Batavia, IL (United States); Devred, A.; DiMarco, J.; Kuzminski, J.; Ogitsu, T.; Yu, Y.; Zheng, H. [Superconducting Super Collider Lab., Dallas, TX (United States)

1992-10-01

422

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

423

Information Content of the Low-Energy Electric Dipole Strength: Correlation Analysis  

SciTech Connect

Background: Recent experiments on the electric dipole (E1) polarizability in heavy nuclei have stimulated theoretical interest in the low-energy electric dipole strength, both isovector and isoscalar. Purpose: We study the information content carried by the electric dipole strength with respect to isovector and isoscalar indicators characterizing bulk nuclear matter and finite nuclei. To separate isoscalar and isovector modes, and low-energy strength and giant resonances, we analyze the E1 strength as a function of the excitation energy E and momentum transfer q. Methods: We use the self-consistent nuclear density functional theory with Skyrme energy density functionals, augmented by the random phase approximation, to compute the E1 strength and covariance analysis to assess correlations between observables. Calculations are performed for the spherical, doubly magic nuclei 208Pb and 132Sn. Results: We demonstrate that E1 transition densities in the low-energy region below the giant dipole resonance exhibit appreciable state dependence and multinodal structures, which are fingerprints of weak collectivity. The correlation between the accumulated low-energy strength and the symmetry energy is weak, and dramatically depends on the energy cutoff assumed. On the other hand, a strong correlation is predicted between isovector indicators and the accumulated isovector strength at E around 20 MeV and momentum transfer q 0.65 fm 1. Conclusions: Momentum- and coordinate-space patterns of the low-energy dipole modes indicate a strong fragmentation into individual particle-hole excitations. The global measure of low-energy dipole strength correlates poorly with the nuclear symmetry energy and other isovector characteristics. Consequently, our results do not support the suggestion that there exists a collective pygmy dipole resonance, which is a strong indicator of nuclear isovector properties. By considering nonzero values of momentum transfer, one can isolate individual excitations and nicely separate low-energy excitations from the T=1 and T=0 giant collective modes. That is, measurements at q>0 may serve as a tool to correlate the E1 strength with certain bulk observables, such as incompressibility and symmetry energy.

Reinhard, P.-G. [Inst. fur Theoretische Physik II, Univ. Erlangen-Numberg, Germany; Nazarewicz, Witold [UTK/ORNL/University of Warsaw

2013-01-01

424

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

425

Local Observation of Field Polarity Dependent Flux Pinning by Magnetic Dipoles.  

PubMed

A scanning Hall probe microscope is used to study flux pinning in a thin superconducting Pb film covering a square array of single-domain Co dots with in-plane magnetization. We show that single flux quanta of opposite sign thread the superconducting film below T(c) at the opposite poles of these dipoles. Depending on the polarity of the applied field, flux lines are attracted to a specific pole of the dipoles, due to the direct interaction with the vortexlike structures induced by the local stray field. PMID:11136117

Van Bael MJ; Bekaert; Temst; Van Look L; Moshchalkov; Bruynseraede; Howells; Grigorenko; Bending; Borghs

2001-01-01

426

Electric dipole moment of the top quark within an effective theory  

SciTech Connect

Using the effective Lagrangian approach, we develope the trilinear contributions originated in the dimension-six electroweak invariants O-tilde{sub W} = (1/3){epsilon}{sub ijk}W{sup i{mu}}{sub v}W{sup jv}{sub {lambda}}W{sup k{lambda}}{sub {mu}} and O-tilde{sub WB} = (1/2)B-tilde{sub {alpha}}{sub {beta}}W{sup c{alpha}}{sup {beta}}{phi}{sup {dagger}}{tau}{sup c}{phi}, and then we insert the corresponding vertices in a one-loop ttV diagram, with V off-shell, generating the structure of the electric dipole moment. Using a nonlinear gauge, we prove that the results are gauge independent. Finally, we present the analytic expressions for the electric dipole form factors originated in each invariant introduced.

Novales-Sanchez, H. [Facutad de Ciencias Fisico-Matematicas, Benemerita Universidad Autonoma de Puebla. Apartado Postal 1152, Puebla, Pue. (Mexico); Toscano, J. J. [Instituto de Fisica y Matematicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio C-3, Ciudad Universitaria, C. P. 58040, Morelia, Michoacan (Mexico)

2009-04-20

427

Two-loop diagrams for the electric dipole moment of the neutron  

NASA Astrophysics Data System (ADS)

CP-violating two-loop Feynman diagrams for the electric dipole moment of the neutron are considered in the framework of the Kobayashi-Maskawa model. It is shown that leading logarithmic contributions ~ 1nMW2 are cancelled by a twofold GIM mechanism. The remaining logarithms of heavy-quark masses are called ``relics of short-distance effects''. It is also found that the calculated contributions are complementary and of the same order of magnitude as some corresponding long-distance contributions considered by other authors. The electric dipole moment of the neutron is estimated not to exceed Dn/e ~10-32 cm. Some details of two-loop integrations are presented, in particular the effectiveness of dimensional regularization in calculating certain individual diagrams. Supported by the SIZ I of SR Croatia and by the NSF YOR 82/051 grant.

Eeg, J. O.; Picek, I.

1984-09-01

428

CP violation and electric-dipole-moment at low energy ? production with polarized electrons  

Microsoft Academic Search

The new proposals for high luminosity B\\/Flavor factories, near and on top of the ? resonances, allow for a detailed investigation of CP-violation in the ?-pair production. In particular, bounds on the tau electric dipole moment can be obtained of genuine CP-odd observables related to the ?-pair production. We perform an independent analysis from low energy (10 GeV) data by

J. Bernabéu; G. A. González-Sprinberg; J. Vidal

2007-01-01

429

Radiation of pulses generated by a vertical electric dipole above a plane, non-conducting, earth  

Microsoft Academic Search

Summary  At a heighth above a plane, non-conducting, earth a vertical electric dipole emits an impulsive electromagnetic wave. The resulting electromagnetic\\u000a field in the air is determined; it consists of a reflected wave which is superimposed upon the given incident wave. The Hertzian\\u000a vector corresponding to the reflected wave is expressed in terms of a single integral over a finite interval;

A. T. De Hoop; H. J. Frankena

1960-01-01

430

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

SciTech Connect

The nuclear electric dipole moment (EDM) and the nuclear Schiff moment for the lowest 1/2{sup +} state of {sup 129}Xe are investigated in terms of the nuclear shell model. We estimate the upper limit for the EDM of neutral {sup 129}Xe atom using the Schiff moment. We also estimate the upper limit of the nuclear EDM, which may be directly measured through ionic atoms.

Yoshinaga, Naotaka [Department of Physics, Saitama University, Saitama City 338-8570 (Japan); Higashiyama, Koji [Department of Physics, Chiba Institute of Technology, Narashino, Chiba 275-0023 (Japan)

2011-05-06

431

Statistical and nonstatistical neutron decay of the giant electric dipole resonance of 208Pb  

Microsoft Academic Search

The neutron decay of the giant electric dipole resonance of 208Pb has been determined by a measurement of the differential cross section, dsigma(Egamma,En)\\/dEn of the 208Pb(gamma,n) reaction for 20 contiguous photon energy bands between 11.2 and 15.7 MeV. The statistical component of the decay was calculated in the Hauser-Feshbach formalism. A nonstatistical component of the decay to low-lying hole states

R. Alarcon; P. L. Cole; D. S. Dale; P. T. Debevec; L. J. Morford

1991-01-01

432

Enhancement factor for the electron electric dipole moment in francium and gold atoms  

Microsoft Academic Search

If electrons had an electric dipole moment (EDM) they would induce EDMs of\\u000aatoms. The ratio of the atomic EDM to the electron EDM for a particular atom is\\u000acalled the enhancement factor, R. We calculate the enhancement factor for the\\u000afrancium and gold atoms, with the results 910 plus\\/minus 5% for Fr and 260\\u000aplus\\/minus 15% for Au. The

T. M. R. Byrnes; V. A. Dzuba; V. V. Flambaum; D. W. Murray

1999-01-01

433

Elasticity of nuclear medium as a principal macrodynamical promoter of electric pygmy dipole resonance  

Microsoft Academic Search

Motivated by arguments of the nuclear core-layer model formulated in [S.I. Bastrukov, J.A. Maruhn, Z. Phys. A 335 (1990) 139], the macroscopic excitation mechanism of the electric pygmy dipole resonance (PDR) is considered as owing its origin to perturbation-induced effective decomposition of a nucleus into two spherical domains–undisturbed inner region treated as a static core and dynamical layer undergoing elastic

S. I. Bastrukov; I. V. Molodtsova; D. V. Podgainy; ?. Mi?icu; H.-K. Chang

2008-01-01

434

Low-energy neutrino Majorana phases and charged-lepton electric dipole moments  

Microsoft Academic Search

If the neutrinos are Majorana fermions, there are at least three new, potentially observable CP-odd phases that parametrize CP-invariance violating phenomena. We currently have no information regarding any of them and know that two out of the three, the so-called Majorana phases, are very hard to access experimentally. Here, we discuss the effect of Majorana phases on charged-lepton electric dipole

André de Gouvêa; Shrihari Gopalakrishna

2005-01-01

435

Non-Markovian theory of relativistic electric-dipole spontaneous emission of hydrogen-like atoms  

Microsoft Academic Search

The non-Markovian corrections to electric-dipole emission of hydrogen-like atoms of large atomic number Z are studied by multipole photon field formulation. The correlation functions are derived by the corresponding spectra, which show how the delta-function type correlation is approached. The decay of upper-level population is calculated by the relevant integro-differential equation. The numerical results show that the relativistic and finite

Chang-qi Cao; Xiao-wei Fu; Hui Cao

2005-01-01

436

Spherical harmonic series solution of fields excited by vertical electric dipole in earth-ionosphere cavity  

Microsoft Academic Search

The spherical harmonic series expression of electromagnetic fields excited by ELF\\/SLF vertical electric dipole in the spherical\\u000a earth-ionosphere cavity is derived when the earth and ionosphere are regarded as non-ideal conductors. A method of speeding\\u000a numerical convergence has been presented. The electromagnetic fields in the cavity are calculated by this algorithm, and the\\u000a results show that the electromagnetic fields between

Yuanxin Wang; Wensheng Fan; Weiyan Pan; Hongqi Zhang

2008-01-01

437

Exact solution for a noncentral electric dipole ring-shaped potential in the tridiagonal representation  

SciTech Connect

The Schroedinger equation with noncentral electric dipole ring-shaped potential is investigated by working in a complete square integrable basis that supports an infinite tridiagonal matrix representation of the wave operator. The three-term recursion relations for the expansion coefficients of both the angular and radial wavefunctions are presented. The discrete spectrum for the bound states is obtained by the diagonalization of the radial recursion relation. Some potential applications of this system in different fields are discussed.

Huangfu Guoqing [Department of Physics and Electronic Engineering, Weinan Teachers University, Weinan 714000 (China); Zhang Mincang [College of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062 (China)

2011-04-15

438

Tune shift effect due to the multipole longitudinal periodic structure in the superconducting dipole magnets  

SciTech Connect

Neglecting the curvature terms, the magnetic field and the vector potential which generate the multipole longitudinal periodic structure in a superconducting dipole magnet are found. Using this field and the standard Hamiltonian perturbation theory, the tune shifts due to this periodic pattern in the superconducting dipole magnets are estimated for the Superconducting Super Collider (SSC) machine. The results suggest that this tune shift is very small for most of the multipoles and could be ignored for the SSC. However, for the quadrupole longitudinal oscillation pattern, the tune shift relative to the amplitude of this oscillation could be of the order of 10{sup {minus}5} and may not be ignored. 12 refs., 4 figs., 3 tabs.

Lopez, G.; Chen, S.

1991-10-01

439

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

440

3D Design, Contruction, and Field Analysis of CIS Main Dipole Magnets  

NASA Astrophysics Data System (ADS)

The lattice for CIS ( Cooler Injection Synchroton ) requires four laminated 90^circ main dipole magnets with bending radius ? = 1.273 m, EFL = 2 m, and an edge angle of 12^circ. Optimum Cooler injection and injection in the planned 15 GeV LISS ring requires operation up to about 1.75 T. Initial operation of 1 Hz, with later upgrade to 5 Hz is planned. We will present 2D and 3D field calculations used to optimize the shape of laminations and endpacks of the magnet. Endpacks are designed to determine edge angle and to compensate hexapole components, in particular above 1.4 T where saturation becomes significant. The large dipole curvature required a new type of dipole construction. Each magnet consists of wedge shaped blocks fabricated from stamped lamination of cold rolled low carbon iron. B-stage (dry) epopy was used for bonding and insulation. The end blocks are machined to include the calculated 3D shape of the endpacks. All four magnets were mapped in the field range from 0.3 T - 1.8 T. Comparison of calculations and data in terms of B(I) curves, EFL, edge angle, and hexapole component as function of field excitation will be presented. The constructed magnets are well within expected specifications.

Berg, G. P. A.; Fox, W.; Friesel, D. L.; Rinckel, T.

1997-05-01

441

Electric and Magnetic Concept Inventory  

NSDL National Science Digital Library

In the summer of 1995, a group of college physics teachers met for a week at Lee College in order to develop a collection of questions for use as an instrument to measure students' conceptual understanding in the areas of electricity and magnetism. This report provides some of the preliminary results of these efforts.

Hieggelke, Curtis J.; Maloney, David

2006-06-19

442

Electric and Magnetic Forces: Electromagnetism  

NSDL National Science Digital Library

Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach.This Science Object is the last of three Science Objects in the Electric and Magnetic Forces SciPack.

National Science Teachers Association (NSTA)

2008-10-30

443

Possible Sensitivity Increase of the Installation for Neutron Electric Dipole Momentum Measurement by Means of Ultracold Neutrons.  

National Technical Information Service (NTIS)

A possibility is discussed for increasing the sensitivity of the installation for measuring a neutron electric dipole moment through use of ultracold neutrons in the ''storage'' variant due to the introduction of the moving polarizer. It is shown that the...

Y. V. Taran

1974-01-01

444

Analysis of Lightning Induced Magnetic Field Penetration Through Protective Metal Screens Using an Equivalent Magnetic Dipole Moment Representation of an Array of Elliptic Apertures.  

National Technical Information Service (NTIS)

This investigation analyzed lightning induced magnetic field penetration through protective metal screens using an equivalent magnetic dipole moment representation of an array of elliptic apertures. Two metal screens with differing aperture sizes were mod...

J. L. O'Neal

1986-01-01

445

40 mm bore Nb-Ti model dipole magnet  

SciTech Connect

Preliminary R and D has been started on magnets for a next-generation high-energy-physics accelerator, the 20 TeV Superconducting Supercollider (SSC). One design now being developed at LBL is described in this paper. The design is based on two layers of flattened Nb-Ti cable, a 40 mm ID winding with flared ends, and an operating field of 6.5 T. Experimental results are presented on several one-meter-long models tested at both He I and He II temperature. Measurement of field, residual magnetization, quench propagation velocity, and winding prestress are presented. (A 2-in-1 magnet based on this coil design is being jointly developed by LBL and Brookhaven National Laboratory, and 15 ft. long models are being constructed at BNL).

Taylor, C.; Gilbert, W.; Hassenzahl, W.; Meuser, R.; Peters, C.; Rechen, J.; Scanlan, R.

1984-09-10

446

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

2009-12-09

447

Extracting Irreversible Dephasing Rates from Electric Dipole Echoes in Rydberg Stark Wave Packets  

SciTech Connect

The precession of an electric dipole moment in an external electric field can be reversed by reversing the field direction. This time-reversal operation allows study of coherence in the time evolution of Rydberg Stark wave packets by measuring the resulting echoes. Different sources of reversible dephasing and irreversible dephasing, i.e., decoherence, are discussed in detail. Stochastic interactions with the environment are simulated in a controlled manner by using artificially synthesized noise. The rate of irreversible dephasing is determined from the reduction of the echo amplitude under multiple field reversals.

Yoshida, S. [Institute for Theoretical Physics, Vienna University of Technology, Austria; Reinhold, Carlos O [ORNL; Burgdorfer, J. [Institute for Theoretical Physics, Vienna University of Technology, Austria; Zhao, W. [Rice University; Mestayer, J. J. [Rice University; Lancaster, J. C. [Rice University; Dunning, F. B. [Rice University

2008-12-01

448

High-resolution spectroscopy on trapped molecular ions in rotating electric fields: A new approach for measuring the electron electric dipole moment  

NASA Astrophysics Data System (ADS)

Spectroscopy on a trapped diatomic molecular ion with a ground or metastable 3 ? 1 level could prove to be a sensitive probe for a permanent electron electric dipole moment. High-resolution molecular spectroscopy is a sensitive probe of fundamental physics. A rotating electric field can be used to polarize trapped molecular ions. High-resolution spectroscopy can be performed in the presence of rapidly time-varying fields. Spectroscopy on polarized, trapped molecular ions can probe for an electron electric dipole moment.

Leanhardt, A. E.; Bohn, J. L.; Loh, H.; Maletinsky, P.; Meyer, E. R.; Sinclair, L. C.; Stutz, R. P.; Cornell, E. A.

2011-11-01

449

Fast Convergence Algorithm for Earthquake Prediction Using SLF\\/ELF Horizontal Electric Dipole during Day and Night and Schumann Resonance  

Microsoft Academic Search

Electromagnetic wave radiation from a SLF\\/ELF horizontal electric dipole (HED) related to seismic activity is discussed. In\\u000a order to estimate the effects on the electromagnetic waves associated with the seismic activity, SLF\\/ELF waves on the ground\\u000a radiated from a possible seismic current source modeled as a electric dipole, are precisely computed by using a speeding numerical\\u000a convergence algorithm. A theoretical

Yuan-xin Wang; Rong-hong Jin; Jun-ping Geng

450

Mercury intrinsic magnetic field : Limits of the offset-dipole representation  

NASA Astrophysics Data System (ADS)

The interaction of the solar wind (SW) with the magnetic field of The analysis of MESSENGER orbital observations led Anderson et al (2011) to propose a dipole centered on the spin axis of the planet with a northward offset equal to 484±11 km to represent the intrinsic magnetic field of Mercury at northern latitudes higher than 30°. The magnetic moment has a magnitude of 195±10nT, points southward and is tilted by less than 3° with respect to the spin axis. The restriction to northern latitude comes from the lack of low altitude measurements of the magnetic field at southern latitudes due to MESSENGER orbit. Hence for the moment being there is no observation to constrain the representation of the southern planetary field. The suggested offset is equal to about 20% of the planetary radius which is quite a large value by comparison to 8.5% in the terrestrial case although with a lateral offset. This representation of the intrinsic field by an offset dipole suggests that the southern polar cap should be much wider than the northern one, leading to important consequences for magnetospheric dynamics. Nevertheless the offset dipole is just a convenient representation that can be fitted by the first terms of the multipolar development. The surface field of the planet produced by the offset dipole (OD) proposed by Anderson et al (2011) is thus fitted by the sum of a dipolar and a quadrupolar field (DQ) for northern latitudes higher than 50°. The resulting field differs slightly from the offset dipole field at northern latitudes but a separatrix exists at southern latitudes between dipolar-like and quadrupolar like field lines. This separatrix begins on the polar axis at an altitude RS equal to three times the ratio of the quadrupolar to the dipolar moment. When the relative axial offset of the dipole becomes larger than 16% then RS becomes larger than the planetary radius leading to important topological changes of the southern field. Global hybrid simulations of the Hermean magnetosphere for the two models OD and DQ demonstrate that the southern magnetosphere produced by the DQ model differs greatly from what is expected using the OD model (Richer et al 2012). Reference: Anderson et al., Science, 333 , 1859, (2011) Richer, E., R. Modolo, G. M. Chanteur, S. Hess, and F. Leblanc (2012), A global hybrid model for Mercury's interaction with the solar wind: Case study of the dipole representation, J. Geophys. Res., 117, A10228, doi:10.1029/2012JA017898.

Chanteur, Gérard M.; Modolo, Ronan; Richer, Emilie; Hess, Sébastien; Leblanc, François

2013-04-01

451

Magnetic dipole moments of Cu58 and Cu59 by in-source laser spectroscopy  

Microsoft Academic Search

Online measurements of the magnetic dipole moments and isotope shifts of Cu58 and Cu59 by the in-source laser spectroscopy method are reported. The results for the magnetic moments are mu (Cu58) =+0.52(8)muN,mu(Cu59) =+1.84(3)muN and for the isotope shifts deltanu59,65=1.72(22) GHz and deltanu58,65=1.99(30) GHz in the transition from the 3d104sS21\\/2 ground state to the 3d104pP21\\/2 state in Cu I. The magnetic

N. J. Stone; U. Köster; J. Rikovska Stone; D. V. Fedorov; V. N. Fedoseyev; K. T. Flanagan; M. Hass; S. Lakshmi

2008-01-01

452

Magnetic dipole and quadrupole response of nuclei, supernova physics and in-medium vector meson scaling  

NASA Astrophysics Data System (ADS)

The relevance of magnetic dipole and quadrupole strength distributions for the physics of a type II supernova are discussed. A recently developed high-resolution, large solid-angle system for the detection of 180° electron scattering at the superconducting Darmstadt electron linear accelerator (S-DALINAC) is introduced which represents a unique tool for the study of low-multipolarity magnetic transitions. First results discussed include the modification of the M1 strength in complex nuclei by meson exchange currents, the overall quenching of M2 strength and possible tests of in-medium vector meson scaling (Brown-Rho scaling) by selected magnetic form factors.

Lüttge, C.; von Neumann-Cosel, P.; Neumeyer, F.; Richter, A.

1996-02-01

453

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

454

Undulation instability in a bilayer lipid membrane due to electric field interaction with lipid dipoles  

NASA Astrophysics Data System (ADS)

Bilayer lipid membranes (BLMs) are an essential component of all biological systems, forming a functional barrier for cells and organelles from the surrounding environment. The lipid molecules that form membranes contain both permanent and induced dipoles, and an electric field can induce the formation of pores when the transverse field is sufficiently strong (electroporation). Here, a phenomenological free energy is constructed to model the response of a BLM to a transverse static electric field. The model contains a continuum description of the membrane dipoles and a coupling between the headgroup dipoles and the membrane tilt. The membrane is found to become unstable through buckling modes, which are weakly coupled to thickness fluctuations in the membrane. The thickness fluctuations, along with the increase in interfacial area produced by membrane buckling, increase the probability of localized membrane breakdown, which may lead to pore formation. The instability is found to depend strongly on the strength of the coupling between the dipolar headgroups and the membrane tilt as well as the degree of dipolar ordering in the membrane.

Bingham, Richard J.; Olmsted, Peter D.; Smye, Stephen W.

2010-05-01

455

Directional magnetoelectric effects in MnWO4: magnetic sources of the electric polarization.  

PubMed

The ferroelectric order and magnetic field induced effects observed in the spiral phase of MnWO4 are described theoretically. It is demonstrated explicitly that the Dzyaloshinskii-Moriya antisymmetric interactions contribute to the correlation between spins and electric dipoles in the incommensurate and commensurate ferroelectric phases of magnetic multiferroics. However, other single-site symmetric interactions are shown to be involved in the magnetoelectric process, suggesting the possible existence of an electric polarization originating from purely symmetric effects. PMID:21389374

Tolédano, P; Mettout, B; Schranz, W; Krexner, G

2010-01-22

456

Directional magnetoelectric effects in MnWO4: magnetic sources of the electric polarization  

NASA Astrophysics Data System (ADS)

The ferroelectric order and magnetic field induced effects observed in the spiral phase of MnWO4 are described theoretically. It is demonstrated explicitly that the Dzyaloshinskii-Moriya antisymmetric interactions contribute to the correlation between spins and electric dipoles in the incommensurate and commensurate ferroelectric phases of magnetic multiferroics. However, other single-site symmetric interactions are shown to be involved in the magnetoelectric process, suggesting the possible existence of an electric polarization originating from purely symmetric effects.

Tolédano, P.; Mettout, B.; Schranz, W.; Krexner, G.

2010-02-01

457

Final report on the CERN muon storage ring including the anomalous magnetic moment and the electric dipole moment of the muon, and a direct test of relativistic time dilation  

Microsoft Academic Search

A comprehensive description of the muon storage ring and its operation is given, and the final results of the experiment are presented and discussed. The anomalous magnetic moments of positive and negative muons are found to be amu+ = 1165911(11) × 10-9 and amu- = 1165937(12) × 10-9 giving an average value for muons of amu = 1165924(8.5) × 10-9.

J. Bailey; K. Borer; F. Combley; H. Drumm; C. Eck; F. J. M. Farley; J. H. Field; W. Flegel; P. M. Hattersley; F. Krienen; F. Lange; G. Lebée; E. McMillan; G. Petrucci; E. Picasso; O. Rúnolfsson; W. von Rüden; R. W. Williams; S. Wojcicki

1979-01-01

458

Kick velocity induced by magnetic dipole and quadrupole radiation  

Microsoft Academic Search

We examine the recoil velocity induced by the superposition of the magnetic\\u000adipole and quadrupole radiation from a pulsar\\/magnetar born with rapid\\u000arotation. The resultant velocity depends on not the magnitude, but rather the\\u000aratio of the two moments and their geometrical configuration. The model does\\u000anot necessarily lead to high spatial velocity for a magnetar with a strong\\u000amagnetic

Yasufumi Kojimaand; Yugo E. Kato

2010-01-01

459

Electric-Dipole{endash}Quadrupole Interference of Overlapping Autoionizing Levels in Photoelectron Energy Spectra  

SciTech Connect

We have measured the photon energy dependence of electric-dipole{endash}quadrupole interference in cadmium between the odd parity 4d{sup 9}5s{sup 2}5p J=1 and even parity 5p6p {sup 3} P{sub 2} autoionizing levels. The resonant interference structure is isolated by taking the difference between constant ionic state spectra at 45{degree} with respect to the photon beam in the forward and backward directions. We find interference effects that are approximately 0.5{percent} of the dipole cross section for photon energies of 13thinspeV, in good agreement with theory. We compare the results with those from (e,thinsp2e) experiments. {copyright} {ital 1998} {ital The American Physical Society }

Martin, N.L.; Thompson, D.B.; Bauman, R.P. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055 (United States); Caldwell, C.D.; Krause, M.O.; Frigo, S.P. [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Wilson, M. [Physics Department, Royal Holloway, University of London, Egham, Surrey TW20 0EX (United Kingdom)

1998-08-01

460

Progress Towards Laser Trapping of 225Ra for an Electric Dipole Moment Measurement  

SciTech Connect

Many extensions to the Standard Model, such as supersymmetry, predict electric dipole moments (EDMs) just below current experimental sensitivity. In 225Ra, which has an octupole-deformed nucleus, the signature of an EDM is expected to be amplified by two to three orders of magnitude relative to previously studied systems. We plan to collect 225Ra atoms in a magneto-optical trap and transfer the sample to an optical dipole trap where the EDM measurement can be performed. To this end, we have measured the absolute 1S0(F=1/2){r_reversible}3P1(F=3/2) transition frequency and determined the lifetime of the lowest 3P1 state in 225Ra. Development of a magneto-optical trap based on this transition is underway.

Scielzo, N. D.; Ahmad, I.; Bailey, K.; Guest, J. R.; Holt, R. J.; O'Connor, T. P.; Potterveld, D. H.; Schulte, E. C. [Physics Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Bowers, D. L. [Chemical Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Lu, Z.-T. [Physics Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States)

2006-07-11

461

Real-Time Localization of Moving Dipole Sources for Tracking Multiple Free-Swimming Weakly Electric Fish  

PubMed Central

In order to survive, animals must quickly and accurately locate prey, predators, and conspecifics using the signals they generate. The signal source location can be estimated using multiple detectors and the inverse relationship between the received signal intensity (RSI) and the distance, but difficulty of the source localization increases if there is an additional dependence on the orientation of a signal source. In such cases, the signal source could be approximated as an ideal dipole for simplification. Based on a theoretical model, the RSI can be directly predicted from a known dipole location; but estimating a dipole location from RSIs has no direct analytical solution. Here, we propose an efficient solution to the dipole localization problem by using a lookup table (LUT) to store RSIs predicted by our theoretically derived dipole model at many possible dipole positions and orientations. For a given set of RSIs measured at multiple detectors, our algorithm found a dipole location having the closest matching normalized RSIs from the LUT, and further refined the location at higher resolution. Studying the natural behavior of weakly electric fish (WEF) requires efficiently computing their location and the temporal pattern of their electric signals over extended periods. Our dipole localization method was successfully applied to track single or multiple freely swimming WEF in shallow water in real-time, as each fish could be closely approximated by an ideal current dipole in two dimensions. Our optimized search algorithm found the animal’s positions, orientations, and tail-bending angles quickly and accurately under various conditions, without the need for calibrating individual-specific parameters. Our dipole localization method is directly applicable to studying the role of active sensing during spatial navigation, or social interactions between multiple WEF. Furthermore, our method could be extended to other application areas involving dipole source localization.

Jun, James Jaeyoon; Longtin, Andre; Maler, Leonard

2013-01-01

462

Electric Dipole Moments of Light Nuclei and the Implications for CP Violation  

NASA Astrophysics Data System (ADS)

A definitive measurement of an electric dipole moment (EDM) would likely imply new physics beyond the standard model. Although the standard model strong interaction term could theoretically produce an EDM of any size, that it is constrained by the current neutron EDM limit to be some 10 orders of magnitude smaller than 1 suggests that the electroweak sector and CP violation will be the source of a measurable EDM. The weak interaction standard model EDM is itself orders of magnitude smaller than contemporary experiments can measure. Direct measurement of the neutron EDM lies in the next decade; measurement of the proton EDM could well come first. A BNL proposal for an electrostatic storage ring measurement lies in the offing. Unless the EDM proves to be an isoscalar, one will need other measurements to separate the isoscalar, isovector, and isotensor components. Measurement of a nuclear EDM will be required: 2H, 3H, or 3He being the simplest nuclear systems. A storage ring measurement of the triton EDM could be accomplished in a manner analogous to that proposed for the proton. However, the deuteron EDM measurement offers certain advantages, even though the experiment would be more complex, involving electric and magnetic fields, than that required for the proton and triton. The COSY facility in the Forschungszentrum Juelich is almost an ideal facility to house such an experiment; one could also measure in the same ring the EDM for the proton and He. The deuteron is the one nucleus for which exact model calculations can easily be performed. We briefly explore the model dependence of deuteron EDM calculations. Using a separable potential formulation of the Hamiltonian, we examine the sensitivity of the deuteron EDM to variations in the nucleon-nucleon interaction, including contemporary potential models, and we explore the dependence upon intermediate state multiple scattering in the 3P1 channel. We investigate the tensor force contribution to the model results and examine the effects of short-range repulsion that characterize realistic, contemporary potential models of the deuteron. Because one-pion exchange dominates the EDM calculation, separable potential model calculations appear to provide an adequate description of the deuteron EDM until such time as a measurement of better than 10 % is achieved.

Gibson, B. F.; Afnan, I. R.

2013-03-01

463

Simulation and Characterization of the MINER{nu}A Dipole Magnets  

SciTech Connect

The MINER{nu}A (Main INjector ExpeRiment for {nu} A) experiment (http://minerva.fnal.gov/) is a neutrino scattering experiment which uses the NuMI beamline at Fermilab. It seeks to measure low energy neutrino interactions both to support neutrino oscillation experiments and to study the strong dynamics of the nucleon and nucleus that affect these interactions. For energy calibration of the main detector, a tertiary test beam line was designed and commissioned. This test beam consisted of target, collimator, two TOF stations and four wire chamber stations. Two dipole trim magnets were used to form a spectrometer. Here we present the simulation and characterization of these dipole magnets.

Felix, J.; Castorena, J.; Higuera, A.; Urrutia, Z. [Universidad de Guanajuato, Division de Ciencias e Ingenierias, Departamento de Fisica, Leon GTO, 37150 Mexico (Mexico); Zavala, G. [Universidad de Guanajuato, UCEA, Guanajuato GTO (Mexico)

2009-12-17

464

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

465

The Nuclear Magnetic Dipole Moments of the Stable Isotopes of Europium and the Hyperfine Structure Anomaly  

Microsoft Academic Search

The nuclear magnetic dipole moment of 151Eu and the ratio of the moments of 151Eu and 153Eu have been measured by the new method of resonance in three loops in a short atomic beam. The results are: mu(151Eu) = 3.419 ± 0.004 n.m.; mu(151Eu)\\/mu(153Eu) = 2.2686 ± 0.0015. The result, taken together with the ratio of the hyperfine structures of

F. M. Pichanick; P. G. H. Sandars; G. K. Woodgate

1960-01-01

466

On the nuclear spin and magnetic dipole moment of 180Ta  

Microsoft Academic Search

The hyperfine structure of an atomic transition in 180Ta was investigated by laser-induced resonance fluorescence. As a result we obtained for the quantity muI180 (1+1\\/2I180) the value 5.04 (5) muN. This experimental result is best reproduced assuming parallel coupling of a 9\\/2-[514] proton and a 9\\/2+[624] neutron. It is concluded that 180Ta most likely has Ipi=9- and a magnetic dipole

B. Burghardt; R. Harzer; H. J. Hoeffgen; G. Meisel

1980-01-01

467

Initial measurements of the lunar induced magnetic dipole moment using Lunar Prospector magnetometer data  

Microsoft Academic Search

Twenty-one orbits of Lunar Prospector magnetometer data obtained during an extended passage of the Moon through a lobe of the geomagnetic tail in April 1998 are applied to estimate the residual lunar induced magnetic dipole moment. Editing and averaging of individual orbit segments yields a negative induced moment with amplitude -2.4+\\/-1.6×1022Gauss-cm3 per Gauss of applied field. Assuming that the induced

Lon L. Hood; David L. Mitchell; Robert P. Lin; Mario H. Acuna; Alan B. Binder

1999-01-01

468

One-loop MSSM contribution to the weak magnetic dipole moments of heavy fermions  

Microsoft Academic Search

The MSSM predictions at the one-loop level for the weak-magnetic dipole moments of the ? lepton and the b quark are analysed. The entire supersymmetric parameter space is scanned with the usual GUT constraint and common squark and slepton mass parameters. The real part of aW? is dominated by the chargino contribution, being the same order as the SM one

W. Hollik; J. I. Illana; S. Rigolin; D. Stöckinger

1998-01-01

469

Exotic-atom measurement of the magnetic dipole moment of the Sigma hyperon  

Microsoft Academic Search

The magnetic dipole moment of the Sigma- hyperon has been determined from Sigma--atom x-ray transitions in natural lead and tungsten. Negative kaons were stopped in a target which consisted of sheets of W or Pb immersed in liquid hydrogen. The Sigma- resulting from the reaction K-p-->Sigma-pi+ were tagged by observing the monoenergetic pi+. X rays from Sigma- atoms were detected

D. W. Hertzog; M. Eckhause; P. P. Guss; D. Joyce; J. R. Kane; W. C. Phillips; W. F. Vulcan; R. E. Welsh; R. J. Whyley; R. G. Winter; E. Austin; J. P. Miller; F. O'brien; B. L. Roberts; G. W. Dodson; R. J. Powers; R. B. Sutton; A. R. Kunselman

1988-01-01

470

Thermal and structural performance of a single tube support post for the Superconducting Super Collider dipole magnet cryostat.  

National Technical Information Service (NTIS)

The reentrant support post currently incorporated in the Superconducting Super Collider (SSC) dipole cryostat has been shown to meet the structural and thermal requirements of the cryostat, both in prototype magnet assemblies and through component testing...

W. N. Boroski T. H. Nicol M. K. Ruschman C. J. Schoo

1993-01-01

471

Magnetic Measurements of the Prototype Dipole for the IR-FEL at the Thomas Jefferson National Accelerator Facility  

NASA Astrophysics Data System (ADS)

Magnetic measurements have been performed on the dipole.html>prototype dipole for the high power IR-FEL presently under construction at the Thomas Jefferson National Accelerator Facility. The optics-driven requirements for these magnets include low fields, large horizontal apertures, tight field homogeneity, absolute setability of core field and integrated field, and control of the horizontal and vertical focusing terms designed into the magnets. A prototype dipole was fabricated and underwent several iterations of mechanical adjustment and magnetic measurement. Measurements were made to quantify the effects of field clamps on vertical focusing terms and effective length. Additional tests were made using various applications of Purcell gaps and high permeability materials in order to achieve the required homogeneity. Results from the prototype have been integrated into the design of the six styles of dipoles needed for the FEL.

Karn, J.; Biallas, G.; Guerra, A.; Harwood, L.

1997-05-01

472

The magnetic dipole transitions in the ( c bar b ) binding system  

NASA Astrophysics Data System (ADS)

The magnetic dipole transitions between the vector mesons B* c and their relevant pseudoscalar mesons B c ( B c , B* c , B c (2 S), B* c (2 S), B c (3 S), B* c (3 S) etc., the binding states of ( c bar b ) system) of the B c family are interesting. The ‘hyperfine’ splitting due to spin-spin interaction is an important topic for understanding the spin-spin interaction and the spectrum of the the ( c bar b ) binding system. The knowledge about the magnetic dipole transitions is also very useful for identifying the vector boson B* c mesons experimentally, whose masses are just slightly above the masses of their relevant pseudoscalar mesons B c . Considering the possibility to observe the vector mesons via the transitions at Z 0 factory and the potential use of the theoretical estimate on the transitions, we fucus our efforts on calculating the magnetic dipole transitions, i.e. a precise calculation of the rates for the transitions such as decays B* c ? B c ? and B* c ? B c e + e -, and particularly work in the Bethe-Salpeter framework. As a typical example, we carefully investigate the dependence of the rate ?( B* c ? B c ?) on the mass difference ? M = M_{B_c^* } - M_{B_c }.

Ke, Hongwei; Wang, Guoli; Li, Xueqian; Chang, Chaohsi

2010-11-01

473

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

474

Spin-torque-induced rotational dynamics of a magnetic vortex dipole  

NASA Astrophysics Data System (ADS)

We study, both experimentally and by numerical modeling, the magnetic dynamics that can be excited in a magnetic thin-film nanopillar device using the spin torque from a spatially localized current injected via a tens-of-nanometer-diameter aperture. The current-driven magnetic dynamics can produce large-amplitude microwave emission at zero magnetic field, with a frequency well below that of the uniform ferromagnetic resonance mode. Micromagnetic simulations indicate that the physical origin of this efficient microwave nano-oscillator is the nucleation and subsequent steady-state rotational dynamics of a magnetic vortex dipole driven by the localized spin torque. The results show that this implementation of a spintronic nano-oscillator is a promising candidate for microwave technology applic