Quark electric dipole moment induced by magnetic field
P. V. Buividovich; M. N. Chernodub; E. V. Luschevskaya; M. I. Polikarpov
2010-02-12
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.
Table of nuclear magnetic dipole and electric quadrupole moments
N. J. Stone
2005-01-01
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
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
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.
Magnetic and Electric Dipole Constraints on Extra Dimensions and Magnetic Fluxes
Aaron J. Roy; Myron Bander
2008-05-10
The propagation of charged particles and gauge fields in a compact extra dimension contributes to $g-2$ of the charged particles. In addition, a magnetic flux threading this extra dimension generates an electric dipole moment for these particles. We present constraints on the compactification size and on the possible magnetic flux imposed by the comparison of data and theory of the magnetic moment of the muon and from limits on the electric dipole moments of the muon, neutron and electron.
PHYSICAL REVIEW A 84, 034502 (2011) Magnetic and electric dipole moments of the H 3
Gabrielse, Gerald
2011-01-01
PHYSICAL REVIEW A 84, 034502 (2011) Magnetic and electric dipole moments of the H 3 1 state in Th 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 H and the molecule
Quark electric dipole moment induced by magnetic field in SU(2) gluodynamics
Luschevskaya, E. V. [ITEP, B. Cheremushkinskaya 25, Moscow, 117218 (Russian Federation); JINR, Dubna, Moscow region, 141980 (Russian Federation); 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); ITEP, B. Cheremushkinskaya 25, Moscow, 117218 (Russian Federation); Polikarpov, M. I. [ITEP, B. Cheremushkinskaya 25, Moscow, 117218 (Russian Federation)
2011-05-23
We show that in the external Abelian magnetic field the topological fluctuations of the vacuum of gluodynamics lead to an appearance of the electric dipole moment of quarks in the direction of the magnetic field. The correlation between the electric dipole moment with the chiral density increases with the strength of the field. Thermal fluctuations decrease the correlation between these two quantities.
Kenichi Yamazaki; Tadashi Kawamoto
2001-01-01
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
Yongmin Zhang; Ce Liu; Liang C. Shen
1996-01-01
Traditional measurement-while drilling (MWD) logging tools use magnetic dipoles (coils) as transmitting and receiving antennas and operate at a fixed frequency. In this paper, a new MWD tool using electrical dipoles and using pulses as transmitting signals is investigated and its performance is compared to the coil-type MWD tool in the same formation using a numerical simulation technique. The performances
Campione, Salvatore; Warne, Larry K; Sinclair, Michael B
2014-01-01
In this paper we describe a methodology for tailoring the design of metamaterial dielectric resonators, which represent a promising path toward low-loss metamaterials at optical frequencies. We first describe a procedure to decompose the far field scattered by subwavelength resonators in terms of multipolar field components, providing explicit expressions for the multipolar far fields. We apply this formulation to confirm that an isolated high-permittivity cube resonator possesses frequency separated electric and magnetic dipole resonances, as well as a magnetic quadrupole resonance in close proximity to the electric dipole resonance. We then introduce multiple dielectric gaps to the resonator geometry in a manner suggested by perturbation theory, and demonstrate the ability to overlap the electric and magnetic dipole resonances, thereby enabling directional scattering by satisfying the first Kerker condition. We further demonstrate the ability to push the quadrupole resonance away from the degenerate dipole ...
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
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.
Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments
compilation] and to the journal. Listings of abbreviations used to identify methods and journals are given Arrangement of the Table 3 List of annotations ** List of Experimental Method abbreviations used ** Literature Reference abbreviation list ** General Introduction This Table comprises a listing of measured magnetic
Electric dipole moments, cluster metallicity, and the magnetism of rare earth clusters
John Bowlan
2010-01-01
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
Electric-dipole-active magnetic resonance in the conical-spin magnet Ba2Mg2Fe12O22
NASA Astrophysics Data System (ADS)
Kida, N.; Okuyama, D.; Ishiwata, S.; Taguchi, Y.; Shimano, R.; Iwasa, K.; Arima, T.; Tokura, Y.
2009-12-01
Electric-field (E) drive of magnetic resonance in a solid has been a big challenge in condensed-matter physics and emerging spintronics. We demonstrate the appearance of distinct magnetic excitations driven by the light E component in a hexaferrite Ba2Mg2Fe12O22 . In the conical-spin state even with no spontaneous electric polarization (Ps) , a sharp and intense resonance is observed around 2.8 meV for the light E vector parallel to the magnetic propagation vector in accord with the inelastic neutron scattering spectrum at the magnetic zone center. As the generic characteristic of the conical state, a weak magnetic field (˜2kOe) can modify the spin structure, leading to a remarkable change (terahertz magnetochromism) in spectral shape and intensity (by ˜200% ) of the electric-dipole-active magnetic resonance. The present observation implies that potentially many magnets with noncollinearly ordered spins may host such an electric-dipole-active resonance, irrespective of the presence or absence of Ps .
Electric dipole moment induced by a QCD instanton in an external magnetic field
Gokce Basar; Gerald V. Dunne; Dmitri E. Kharzeev
2011-12-02
In the chiral magnetic effect, there is a competition between a strong magnetic field, which tends to project positively charged particles to have spin aligned along the magnetic field, and a chirality imbalance which may be produced locally by a topologically nontrivial gauge field such as an instanton. We study the properties of the Euclidean Dirac equation for a light fermion in the presence of both a constant abelian magnetic field and an SU(2) instanton. In particular, we analyze the zero modes analytically in various limits, both on R^4 and on the four-torus, in order to compare with recent lattice QCD results, and study the implications for the electric dipole moment.
Coïsson, R
2015-01-01
The interaction between point charge and magnetic dipole is usually considered only for the case of a rigid ferromagnetic dipole (constant-current): here the analysis of force, momentum and energy (including the energy provided by the internal current generator) is generalised to any magnetic dipole behaviour: rigid, paramagnetic, diamagnetic or superconducting (perfectly diamagnetic).
Radiation reaction due to magnetic dipole radiation
Naoki Itoh
1991-01-01
The radiation reaction due to magnetic dipole radiation is calculated for a charged-particle system whose magnetic moment changes with time. The explicit expressions for the electric and magnetic fields due to the magnetic dipole radiation reaction are derived, they are found to originate in the fourth-order term in the expansion of the retarded potential, whereas the field due to the
Axion Induced Oscillating Electric Dipole Moments
Hill, Christopher T
2015-01-01
The axion electromagnetic anomaly induces an oscillating electric dipole for any static magnetic dipole. Static electric dipoles do not produce oscillating magnetic moments. This is a low energy theorem which is a consequence of the space-time dependent cosmic background field of the axion. The electron will acquire an oscillating electric dipole of frequency $m_a$ and strength $\\sim 10^{-32}$ e-cm, two orders of magnitude above the nucleon, and within four orders of magnitude of the present standard model DC limit. This may suggest sensitive new experimental venues for the axion dark matter search.
S. Afach; C. A. Baker; G. Ban; G. Bison; K. Bodek; Z. Chowdhuri; M. Daum; M. Fertl; B. Franke; P. Geltenbort; K. Green; M. G. D. van der Grinten; Z. Grujic; P. G. Harris; W. Heil; V. Hélaine; R. Henneck; M. Horras; P. Iaydjiev; S. N. Ivanov; M. Kasprzak; Y. Kermaïdic; K. Kirch; P. Knowles; H. -C. Koch; S. Komposch; A. Kozela; J. Krempel; B. Lauss; T. Lefort; Y. Lemière; A. Mtchedlishvili; O. Naviliat-Cuncic; J. M. Pendlebury; F. M. Piegsa; G. Pignol; P. N. Prashant; G. Quéméner; D. Rebreyend; D. Ries; S. Roccia; P. Schmidt-Wellenburg; N. Severijns; A. Weis; E. Wursten; G. Wyszynski; J. Zejma; J. Zenner; G. Zsigmond
2015-03-30
We report on the measurement of a Larmor frequency shift proportional to the electric-field strength for $^{199}{\\rm Hg}$ atoms contained in a volume permeated with aligned magnetic and electric fields. This shift arises from the interplay between the inevitable magnetic field gradients and the motional magnetic field. The proportionality to electric-field strength makes it apparently similar to an electric dipole moment (EDM) signal, although unlike an EDM this effect is P- and T-conserving. We have used a neutron magnetic resonance EDM spectrometer, featuring a mercury co-magnetometer and an array of external cesium magnetometers, to measure the shift as a function of the applied magnetic field gradient. Our results are in good agreement with theoretical expectations.
Afach, S; Ban, G; Bison, G; Bodek, K; Chowdhuri, Z; Daum, M; Fertl, M; Franke, B; Geltenbort, P; Green, K; van der Grinten, M G D; Grujic, Z; Harris, P G; Heil, W; Hélaine, V; Henneck, R; Horras, M; Iaydjiev, P; Ivanov, S N; Kasprzak, M; Kermaïdic, Y; Kirch, K; Knowles, P; Koch, H -C; Komposch, S; Kozela, A; Krempel, J; Lauss, B; Lefort, T; Lemière, Y; Mtchedlishvili, A; Naviliat-Cuncic, O; Pendlebury, J M; Piegsa, F M; Pignol, G; Prashant, P N; Quéméner, G; Rebreyend, D; Ries, D; Roccia, S; Schmidt-Wellenburg, P; Severijns, N; Weis, A; Wursten, E; Wyszynski, G; Zejma, J; Zenner, J; Zsigmond, G
2015-01-01
We report on the measurement of a Larmor frequency shift proportional to the electric-field strength for $^{199}{\\rm Hg}$ atoms contained in a volume permeated with aligned magnetic and electric fields. This shift arises from the interplay between the inevitable magnetic field gradients and the motional magnetic field. The proportionality to electric-field strength makes it apparently similar to an electric dipole moment (EDM) signal, although unlike an EDM this effect is P- and T-conserving. We have used a neutron magnetic resonance EDM spectrometer, featuring a mercury co-magnetometer and an array of external cesium magnetometers, to measure the shift as a function of the applied magnetic field gradient. Our results are in good agreement with theoretical expectations.
Araujo, J B; Ferreira, Manoel M
2015-01-01
We analyse some dimension-five CPT-even and Lorentz-violating nonminimal couplings\\ between fermionic and gauge fields in the context of the Dirac equation. Once evaluated the nonrelativistic Hamiltonian, we discuss the behavior of the terms under discrete symmetries and analyse the implied effects. We then use the anomalous magnetic dipole moment and \\ electron electric dipole moment measurements to reach upper bounds of $1$ part in $10^{20}$ and $10^{24}$ $\\left( eV\\right) ^{-1}$, improving the level of restriction on such couplings by at least 8 orders of magnitude.
Axion induced oscillating electric dipole moments
NASA Astrophysics Data System (ADS)
Hill, Christopher T.
2015-06-01
The axion electromagnetic anomaly induces an oscillating electric dipole for any static magnetic dipole. Static electric dipoles do not produce oscillating magnetic moments. This is a low-energy theorem which is a consequence of the spacetime-dependent cosmic background field of the axion in the limit that it is only locally time dependent (v ?/c =0 ). The electron will acquire an oscillating electric dipole of frequency ma and strength ˜10-32 e -cm , 2 orders of magnitude above the nucleon, and within 4 orders of magnitude of the present standard model limit on a constant electron electric dipole moment. This may suggest sensitive new experimental venues for the axion dark-matter search.
Le Roy, Robert J.
Resonant electric dipole-dipole interactions between cold Rydberg atoms in a magnetic field K October 2005; published 5 June 2006 Laser-cooled 85 Rb atoms were optically excited to 46d5/2 Rydberg states. A microwave pulse transferred a fraction of the atoms to the 47p3/2 Rydberg state. The resonant
Lithium electric dipole polarizability
Puchalski, M.; KePdziera, D.; Pachucki, K. [Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, PL-60-780 Poznan (Poland); Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, PL-87-100 Torun (Poland); Faculty of Physics, University of Warsaw, Hoza 69, PL-00-681 Warsaw (Poland)
2011-11-15
The electric dipole polarizability of the lithium atom in the ground state is calculated including relativistic and quantum electrodynamics corrections. The obtained result {alpha}{sub E}=164.0740(5) a.u. is in good agreement with the less accurate experimental value of 164.19(1.08) a.u. The small uncertainty of about 3 parts per 10{sup 6} comes from the approximate treatment of quantum electrodynamics corrections. Our theoretical result can be considered as a benchmark for more general atomic structure methods and may serve as a reference value for the relative measurement of polarizabilities of the other alkali-metal atoms.
Brodsky, Stanley J.; /SLAC; Gardner, Susan; /Kentucky U.; Hwang, Dae Sung; /Sejong U.
2006-01-11
We consider the electric dipole form factor, F{sub 3}(q{sup 2}), as well as the Dirac and Pauli form factors, F{sub 1}(q{sup 2}) and F{sub 2}(q{sup 2}), of the nucleon in the light-front formalism. We derive an exact formula for F{sub 3}(q{sup 2}) to complement those known for F{sub 1}(q{sup 2}) and F{sub 2}(q{sup 2}). We derive the light-front representation of the discrete symmetry transformations and show that time-reversal- and parity-odd effects are captured by phases in the light-front wave functions. We thus determine that the contributions to F{sub 2}(q{sup 2}) and F{sub 3}(q{sup 2}), Fock-state by Fock-state, are related, independent of the fundamental mechanism through which CP violation is generated. Our relation is not specific to the nucleon, but, rather, is true of spin-1/2 systems in general, be they lepton or baryon. The empirical values of the anomalous magnetic moments, in concert with empirical bounds on the associated electric dipole moments, can better constrain theories of CP violation. In particular, we find that the neutron and proton electric dipole moments echo the isospin structure of the anomalous magnetic moments, {kappa}{sup n} {approx} -{kappa}{sup p}.
Axion Induced Oscillating Electric Dipole Moments
Christopher T. Hill
2015-04-10
The axion electromagnetic anomaly induces an oscillating electric dipole for {\\em any} static magnetic dipole. Static electric dipoles do not produce oscillating magnetic moments. This is a low energy theorem which is a consequence of the space-time dependent cosmic background field of the axion in the limit that it is only locally time dependent $(\\overrightarrow{\\beta}=0)$. The electron will acquire an oscillating electric dipole of frequency $m_a$ and strength $\\sim 10^{-32}$ e-cm, three orders of magnitude above the nucleon, and within four orders of magnitude of the present standard model DC limit. This may suggest sensitive new experimental venues for the axion dark matter search.
How to Introduce the Magnetic Dipole Moment
ERIC Educational Resources Information Center
Bezerra, M.; Kort-Kamp, W. J. M.; Cougo-Pinto, M. V.; Farina, C.
2012-01-01
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…
Neutron Electric Dipole Moment Experiments
Jen-Chieh Peng
2008-04-26
The neutron electric dipole moment (EDM) provides unique information on CP violation and physics beyond the Standard Model. We first review the history of experimental searches for neutron electric dipole moment. The status of future neutron EDM experiments, including experiments using ultra-cold neutrons produced in superfluid helium, will then be presented.
Afach, S.; Fertl, M.; Franke, B., E-mail: beatrice.franke@psi.ch, E-mail: bernhard.lauss@psi.ch; Kirch, K. [Paul Scherrer Institute, Villigen (Switzerland); Institute for Particle Physics, Eidgenössische Technische Hochschule, Zürich (Switzerland); Bison, G.; Burri, F.; Chowdhuri, Z.; Daum, M.; Henneck, R.; Lauss, B., E-mail: beatrice.franke@psi.ch, E-mail: bernhard.lauss@psi.ch; Meier, M.; Schmidt-Wellenburg, P.; Zsigmond, G. [Paul Scherrer Institute, Villigen (Switzerland); Bodek, K.; Zejma, J. [Jagellonian University, Cracow (Poland); Grujic, Z.; Kasprzak, M.; Weis, A. [University of Fribourg (Switzerland); Hélaine, V. [Laboratoire de Physique Corpusculaire, Caen (France); Paul Scherrer Institute, Villigen (Switzerland); Koch, H.-C. [Institut für Physik, Johannes-Gutenberg-Universität, Mainz (Germany); University of Fribourg (Switzerland); and others
2014-08-28
The Surrounding Field Compensation (SFC) system described in this work is installed around the four-layer Mu-metal magnetic shield of the neutron electric dipole moment spectrometer located at the Paul Scherrer Institute. The SFC system reduces the DC component of the external magnetic field by a factor of about 20. Within a control volume of approximately 2.5?m?×?2.5?m?×?3?m, disturbances of the magnetic field are attenuated by factors of 5–50 at a bandwidth from 10{sup ?3} Hz up to 0.5?Hz, which corresponds to integration times longer than several hundreds of seconds and represent the important timescale for the neutron electric dipole moment measurement. These shielding factors apply to random environmental noise from arbitrary sources. This is achieved via a proportional-integral feedback stabilization system that includes a regularized pseudoinverse matrix of proportionality factors which correlates magnetic field changes at all sensor positions to current changes in the SFC coils.
NASA Astrophysics Data System (ADS)
Singer, B. Sh.
2015-06-01
Asymptotic expressions are derived for electromagnetic fields induced by arbitrarily oriented electric and magnetic dipoles in a laterally isotropic stratified medium. Considering that the leading terms, which describe the airwave, decay in accordance with the same geometric law whether the source is a horizontal electric or magnetic dipole, it is suggested to use a transmitter, which combines these sources. It is shown that the airwave greatly diminishes if the amplitudes and phases of the horizontal current and magnetic moments of this transmitter are chosen to minimize the far-zone vertical magnetic field. A properly tuned combined transmitter will induce the electromagnetic field with a relatively small transverse electric mode. Raw electromagnetic data acquired with the combined transmitter will be more sensitive to parameters of the resistive reservoir than data acquired using the traditional horizontal electric dipole type of the transmitter.
Magnetization-induced local electric dipoles and multiferroic properties of Ba2CoGe2O7
NASA Astrophysics Data System (ADS)
Solovyev, I. V.
2015-06-01
Ba2CoGe2O7 , crystallizing in the noncentrosymmetric but nonpolar P 4 ¯21m structure, belongs to a special class of multiferroic materials, whose properties are featured by the presence of rotoinversion symmetry. Unlike inversion, the rotoinversion symmetry can be easily destroyed by magnetization. Moreover, due to the specific structural pattern, in which magnetic Co2 + ions are separated by nonmagnetic GeO4 tetrahedra, the magnetic structure of Ba2CoGe2O7 is relatively soft. Altogether, this leads to a rich variety of multiferroic properties, where the magnetic structure of Ba2CoGe2O7 can be easily deformed by the magnetic field, inducing the net electric polarization in the direction depending on the magnetic symmetry of the system, which itself depends on the direction of the magnetic field. In this paper, we show that all these properties can be successfully explained on the basis of a realistic low-energy model, derived from first-principles electronic structure calculations for the magnetically active Co 3 d bands, and the Berry-phase theory of electronic polarization. Particularly, we argue that the magnetization-induced electric polarization in Ba2CoGe2O7 is essentially local and can be expressed via the expectation values
=Tr [p ?D ?] of some dipole matrices p ? and the site-diagonal density matrices D ? of the magnetic Co atoms. Thus, the basic aspects of multiferroic properties of Ba2CoGe2O7 can be understood already in the atomic limit, where both magnetic anisotropy and magnetoelectric coupling are specified by D ?. Then, the observable polarization is the macroscopic average over the microscopic electric dipoles
. We discuss the behavior of interatomic magnetic interactions, the main contributions to the magnetocrystalline anisotropy, and the spin canting in the x y plane, as well as the similarities and differences between the proposed picture and the phenomenological model of spin-dependent p -d hybridization.
A. L. Barabanov; R. Golub; S. K. Lamoreaux
2005-12-20
The search for particle electric dipole moments represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known E x v field with magnetic field gradients (often referred to as the geometric phase effect [9,10]). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic model for the correlation function which determines the behavior of the frequency shift [11], and show in detail how it depends on the operating conditions of the experiment. We also propose a method to directly measure ths correlation function under the exact conditions of a given experiment.
EXPERIMENTAL LIMIT TO THE ELECTRIC DIPOLE MOMENT OF THE NEUTRON
J. H. Smith; E. M. Purcell; N. F. Ramsey
1957-01-01
An experimental measurement of the electric dipole moment of the neutron ; by a neutron-beam magnetic resonance method is described. The result of the ; experiment is that the electric dipole moment of the neutron equals the charge of ; the electron multiplied by a distance D - ( --0.1 of 2.4) x 10â»Â²Â° cm. ; Consequently, if an electric
Optical force on toroidal nanostructures: toroidal dipole versus renormalized electric dipole
Zhang, Xu-Lin; Lin, Zhifang; Sun, Hong-Bo; Chan, C T
2015-01-01
We study the optical forces acting on toroidal nanostructures. A great enhancement of optical force is unambiguously identified as originating from the toroidal dipole resonance based on the source-representation, where the distribution of the induced charges and currents is characterized by the three families of electric, magnetic, and toroidal multipoles. On the other hand, the resonant optical force can also be completely attributed to an electric dipole resonance in the alternative field-representation, where the electromagnetic fields in the source-free region are expressed by two sets of electric and magnetic multipole fields based on symmetry. The confusion is resolved by conceptually introducing the irreducible electric dipole, toroidal dipole, and renormalized electric dipole. We demonstrate that the optical force is a powerful tool to identify toroidal response even when its scattering intensity is dwarfed by the conventional electric and magnetic multipoles.
Heo, Jae Ho [Physics Department, University of Illinois at Chicago, Chicago, Illinois 60607 (United States)
2009-08-01
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.].
S. Afach; G. Bison; K. Bodek; F. Burri; Z. Chowdhuri; M. Daum; M. Fertl; B. Franke; Z. Grujic; V. Helaine; R. Henneck; M. Kasprzak; K. Kirch; H. -C. Koch; A. Kozela; J. Krempel; B. Lauss; T. Lefort; Y. Lemiere; M. Meier; O. Naviliat-Cuncic; F. M. Piegsa; G. Pignol; C. Plonka-Spehr; P. N. Prashanth; G. Quemener; D. Rebreyend; S. Roccia; P. Schmidt-Wellenburg; A. Schnabel; N. Severijns; J. Voigt; A. Weis; G. Wyszynski; J. Zejma; J. Zenner; G. Zsigmond
2014-08-28
The Surrounding Field Compensation (SFC) system described in this work is installed around the four-layer Mu-metal magnetic shield of the neutron electric dipole moment spectrometer located at the Paul Scherrer Institute. The SFC system reduces the DC component of the external magnetic field by a factor of about 20. Within a control volume of approximately 2.5m x 2.5m x 3m disturbances of the magnetic field are attenuated by factors of 5 to 50 at a bandwidth from $10^{-3}$ Hz up to 0.5 Hz, which corresponds to integration times longer than several hundreds of seconds and represent the important timescale for the nEDM measurement. These shielding factors apply to random environmental noise from arbitrary sources. This is achieved via a proportional-integral feedback stabilization system that includes a regularized pseudoinverse matrix of proportionality factors which correlates magnetic field changes at all sensor positions to current changes in the SFC coils.
Lunkenheimer, P.; Muller, J.; Krohns, S.; Schrettle, F.; Loidl, A.; Hartmann, B.; Rommel, R.; de Souza, M.; Hotta, C.; Schlueter, J. A.; Lang, M. (Materials Science Division); (Univ. Augsburg); (Goethe-Univ. Frankfurt); (Kyoto Sangyo Univ.)
2012-01-01
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.
Excitation of Magnetic Dipole Transitions at Optical Frequencies
NASA Astrophysics Data System (ADS)
Kasperczyk, Mark; Person, Steven; Ananias, Duarte; Carlos, Luis D.; Novotny, Lukas
2015-04-01
We use the magnetic field distribution of an azimuthally polarized focused laser beam to excite a magnetic dipole transition in Eu3 + ions embedded in a Y2O3 nanoparticle. The absence of the electric field at the focus of an azimuthally polarized beam allows us to unambiguously demonstrate that the nanoparticle is excited by the magnetic dipole transition near 527.5 nm. When the laser wavelength is resonant with the magnetic dipole transition, the nanoparticle maps the local magnetic field distribution, whereas when the laser wavelength is resonant with an electric dipole transition, the nanoparticle is sensitive to the local electric field. Hence, by tuning the excitation wavelength, we can selectively excite magnetic or electric dipole transitions through optical fields.
Excitation of magnetic dipole transitions at optical frequencies.
Kasperczyk, Mark; Person, Steven; Ananias, Duarte; Carlos, Luis D; Novotny, Lukas
2015-04-24
We use the magnetic field distribution of an azimuthally polarized focused laser beam to excite a magnetic dipole transition in Eu^{3+} ions embedded in a Y_{2}O_{3} nanoparticle. The absence of the electric field at the focus of an azimuthally polarized beam allows us to unambiguously demonstrate that the nanoparticle is excited by the magnetic dipole transition near 527.5 nm. When the laser wavelength is resonant with the magnetic dipole transition, the nanoparticle maps the local magnetic field distribution, whereas when the laser wavelength is resonant with an electric dipole transition, the nanoparticle is sensitive to the local electric field. Hence, by tuning the excitation wavelength, we can selectively excite magnetic or electric dipole transitions through optical fields. PMID:25955052
Kerimov, B. K., E-mail: kerimovbk@gmail.com; Safin, M. Ya., E-mail: misafin@gmail.co [Moscow State University (Russian Federation)
2009-11-15
Analytic expressions for cross sections and spin asymmetries characterizing processes of elastic weak, electromagnetic, and electroweak scattering of a neutrino (antineutrino) having electromagnetic moments on a polarized or an unpolarized proton target were obtained with allowance for the C-, P-, and T/CP-violating anapole and electric dipole moments and the neutral weak, electric, magnetic, and axial form factors of the proton, and these expressions were analyzed. The behavior of spin asymmetries was studied versus the energy and form-factor parameters.
Electric dipole two equal magnitude,
Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University
Electric dipole two equal magnitude, opposite charged particles separated by distance d What) directions =-=-= 9090 sin dpEdWU Ep·-=-= cospEU #12;Exercise Rank a) magnitude of torque and b) U , greatest to least a) Magnitudes are same U greatest at =180 b) 1 & 3 tie, then 2 &4 sinpE=×= Ep cosp
Magnetic Dipole Moment of Neutrino
Masood, Samina S
2015-01-01
We recalculate the magnetic moment of neutrinos in a hot and dense medium. The magnetic dipole moment of neutrinos is modified at high temperature and chemical potential. We show that the magnetic dipole moment of electron neutrino does not get a significant contribution from thermal background to meet the cosmological bound. However, chemical potential contribution to the magnetic moment is non-ignorable even when chemical potential is an order of magnitude greater than the electron mass. It is demonstrated that this effect is more significant in the models with an extended Higgs sector through neutrino mixing.
Magnetic Dipole Moment of Neutrino
Samina S. Masood
2015-06-03
We recalculate the magnetic moment of neutrinos in a hot and dense medium. The magnetic dipole moment of neutrinos is modified at high temperature and chemical potential. We show that the magnetic dipole moment of electron neutrino does not get a significant contribution from thermal background to meet the cosmological bound. However, chemical potential contribution to the magnetic moment is non-ignorable even when chemical potential is an order of magnitude greater than the electron mass. It is demonstrated that this effect is more significant in the models with an extended Higgs sector through neutrino mixing.
Lower Bounds on the Q of Electrically Small Dipole Antennas
Arthur D. Yaghjian; Howard R. Stuart
2010-01-01
General expressions are obtained for the lower bounds on the quality factor (Q) of electrically small electric- and magnetic-dipole antennas confined to an arbitrarily shaped volume V and excited by general sources or by global electric-current sources alone. The lower-bound expressions depend only on the direction of the dipole moment with respect to V , the electrical size of V
Electric Dipole Moments of Dyon and `Electron'
Makoto Kobayashi; Taichiro Kugo; Tatsuya Tokunaga
2007-01-01
The electric and magnetic dipole moments of dyon fermions are calculated within N = 2 supersymmetric Yang-Mills theory including the theta-term. It is found, in particular, that the gyroelectric ratio deviates from the canonical value of 2 for the monopole fermion (n_{m} = 1, n_{e} = 0) in the case theta != 0. Then, applying the S-duality transformation to the
Romalis, Mike
Zeeman frequency shifts in an optical dipole trap used to search for an electric-dipole moment M. V to search for an atomic permanent electric-dipole moment EDM . We present numerical results for Cs and Hg moment d and a magnetic dipole moment interacts with electric and mag- netic fields E and B according
Recanati, Catherine
with electric or magnetic properties, for example with the electric dipole moment surface. The symmetrized of the potential energy surface (PES) and of the electric dipole moment surface (EDMS) of the molecule under studyIntegrity bases for covariants of tetrahedral XY4 molecules. Application to the electric dipole
{tau} weak magnetic dipole moment
Gonzalez-Sprinberg, Gabriel [Facultad de Ciencias, Universidad de la Rep'ublica Montevideo (Uruguay)
1998-10-05
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.
Measurability of Nuclear Electric Dipole Moments
L. I. Schiff
1963-01-01
The possibility of measuring a very small nuclear electric dipole moment is explored by calculating the interaction of this moment with an external electric field. It is shown that for a quantum system of point, charged, electric dipoles in an external electrostatic potential of arbitrary form, there is complete shielding; i.e., there is no term in the interaction energy that
Authors A. L. Barabanov; R. Golub; S. K. Lamoreaux
2006-07-17
The search for particle electric dipole moments (edm) represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known $\\overrightarrow{v}\\times \\overrightarrow{E}$ field with magnetic field gradients (often referred to as the geometric phase effect (Commins, ED; Am. J. Phys. \\QTR{bf}{59}, 1077 (1991), Pendlebury, JM \\QTR{em}{et al;} Phys. Rev. \\QTR{bf}{A70}, 032102 (2004)). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic form for the velocity auto-correlation function which determines the velocity-position correlation function which in turn determines the behavior of the frequency shift (Lamoreaux, SK and Golub, R; Phys. Rev \\QTR{bf}{A71}, 032104 (2005)) and show how it depends on the operating conditions of the experiment. We also discuss some additional issues.
Magnetic Field of a Dipole and the Dipole-Dipole Interaction
ERIC Educational Resources Information Center
Kraftmakher, Yaakov
2007-01-01
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…
NEUTRON ELECTRIC-DIPOLE MOMENT, ULTRACOLD NEUTRONS
NEUTRON ELECTRIC-DIPOLE MOMENT, ULTRACOLD NEUTRONS AND POLARIZED 3He R. GOLUB~and Steve K REPORTS (Review Section of Physics Letters) 237, No. 1(1994)1--62. PHYSICS REPORTS North-Holland Neutron electric-dipole moment, ultracold neutrons and polarized 3He R. Goluba and Steve K. Lamoreauxb a
Dipole Relaxation in an Electric Field.
ERIC Educational Resources Information Center
Neumann, Richard M.
1980-01-01
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)
The Muon Electric Dipole Moment
Vernon Barger; Chung Kao; Ashok Das
1997-07-31
The electric dipole moment of the muon ($d_\\mu$) is evaluated in a two Higgs doublet model with a softly broken discrete symmetry. For $\\tan\\beta \\equiv |v_2|/|v_1| \\sim 1$, contributions from two loop diagrams involving the $t$ quark and the $W$ boson dominate; while for $\\tan\\beta \\gsim 10$, contributions from two loop diagrams involving the $b$ quark and the $\\tau$ lepton are dominant. For $8 \\gsim \\tan\\beta \\gsim 4$, significant cancellation occurs among the contributions from two loop diagrams and the one loop contribution dominates for $\\tan\\beta \\sim 7$. For $\\tan\\beta \\gsim 15$, the calculated $d_\\mu$ can be close to the reach of a recently proposed experiment at the Brookhaven National Laboratory.
The Dynamics of an Electric Dipole Moment in a Stochastic Electric Field
Y. B. Band
2013-08-27
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 mo- mentum 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 elec- tric 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.
Coldmass for LHC Dipole Insertion Magnets
Gupta, R.; Alforque, R.; Anerella, M.; Kelly, E.; Plate, S.; Rufer, C.; Wanderer, P.; Willen, E.; Wu, K.C.
1997-10-18
Brookhaven National Laboratory (BNL) is building a number of magnets for the insertion regions of the Large Hadron Collider (LHC). This paper presents the magnetic design and the expected field quality in 2-in-1 dipole magnets. A unique feature of this cold mass design is the use of an oblate-shaped yoke. This concept permits a variety of BNL-built magnets to have a similar overall design and allows the LHC main dipole cryostat, post, etc., to be used in these magnets. The proposed oblate-shaped yoke also offers a way to reduce the overall cryostat size in future magnets. The dipoles will use the same 80 mm aperture coils as used in the Relativistic Heavy Ion Collider (RHIC) dipole magnets, but will use stainless steel collars. The design presented here is still evolving and the magnets may be built differently than described here.
COLDMASS FOR LHC DIPOLE INSERTION MAGNETS.
GUPTA,R.; ALFORQUE,R.; ANERELLA,M.; KELLY,E.; PLATE,S.; RUFER,C.; WANDERER,P.; WILLEN,E.; WU,K.C.
1997-10-20
Brookhaven National Laboratory (BNL) is building a number of magnets for the insertion regions of the Large Hadron Collider (LHC). This paper presents the magnetic design and the expected field quality in 2-in-1 dipole magnets. A unique feature of this coldmass design is the use of an oblate-shaped yoke. This concept permits a variety of BNL-built magnets to have a similar overall design and allows the LHC main dipole cryostat, post, etc., to be used in these magnets. The proposed oblate-shaped yoke also offers a way to reduce the overall cryostat size in future magnets. The dipoles will use the same 80 mm aperture coils as used in the Relativistic Heavy Ion Collider (RHIC) dipole magnets, but will use stainless steel collars. The design presented here is still evolving and the magnets may be built differently than described here.
Electric dipole emission by fullerenes and buckyonions
Susana Iglesias-Groth
2005-09-15
We study the rotation rates and electric dipole emission of hydrogenated icosahedral fullerenes (single and multishell) in various phases of the interstellar medium. Using the formalism of Draine and Lazarian for the rotational dynamics of these molecules in various astrophysical environments, we find effective rotation rates in the range 1-65 GHz with a trend toward lower rotational frequency as the radius of the molecule increases. Owing to the moderately polar nature of the C--H bond, hydrogenated fullerenes (fulleranes) are expected to have a net dipole moment and produce electric dipole radiation. Adopting the same size distribution proposed for fullerenes in the study of the UV extinction bump (2175 \\AA) we predict the dipole electric emission of mixtures of fulleranes for various levels of hydrogenation. We find that these molecules could be the carriers of the anomalous microwave emission recently detected by Watson et al. in the Perseus molecular complex.
Fields and radiation of 'true' and current magnetic dipoles in a medium
NASA Astrophysics Data System (ADS)
Ginzburg, V. L.
'True' and current magnetic dipoles in a medium with permittivity and magnetic permeability are compared in terms of the fields and radiation generated by them. 'True' dipoles are those formed by two magnetic poles (monopoles) of different sign, while current dipoles are those with the form of a miniature ring (solenoid) with current or with the form of a small permanent magnet. As an example, an analysis is made of the energy of Vavilov-Cerenkov emission for point magnetic dipoles of both types as well as for electric dipoles.
Accelerator Magnets:. Dipole, Quadrupole and Sextupole
NASA Astrophysics Data System (ADS)
Hwang, C. S.
2004-02-01
The main characteristics of the magnet design and performance of lattice magnets including dipole, quadrupole, and sextupole magnets, will be presented. The design and construction constraints of the conventional, steel iron yoke, and the direct-current magnets are also discussed. The equations of the ideal pole shapes of the dipole, quadrupole, and sextupole, are used to design the magnets. Several two- or three-dimensional calculation codes are introduced to simulate the magnets. Moreover, a brief description of the injection magnets is also presented. Finally, field measurement and mapping methods are introduced and the results from field measurements by means of a Hall probe are discussed.
Iron saturation control in RHIC dipole magnets
Thompson, P.A.; Gupta, R.C.; Kahn, S.A.; Hahn, H.; Morgan, G.H.; Wanderer, P.J.; Willen, E.
1991-01-01
The Relativistic Heavy Ion Collider (RHIC) will require 360 dipoles of 80 mm bore. This paper discusses the field perturbations produced by the saturation of the yoke iron. Changes have been made to the yoke to reduce these perturbations, in particular, decapole < 10{sup {minus}4}. Measurements and calculations for 6 series of dipole magnets are presented. 2 refs., 2 figs., 1 tab.
Capacitive Stress Transducers in Model Dipole Magnets
Benson, Christopher P.
2010-07-14
Capacitive stress transducers are used to measure mechanical stresses in the windings of superconducting dipole magnets. These transducers consist of a bonded laminate composed of alternating foils of stainless steel and a high-strength polymer...
A superconducting dipole magnet for laser spectroscopy
Wagenhauser, Kenneth Edward
1990-01-01
A SUPERCONDUCTING DIPOLE MAGNET FOR LASER SPECTROSCOPY A Thesis by KENNETH EDWARD WAGENHAUSER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requhements for the degree of MASTER OF SCIENCE... May 1990 Major subject: Physics A SUPERCONDUCTING DIPOLE MAGNET FOR LASER SPECTROSCOPY A thesis by KENNETH EDWARD WAGENHAUSER Approved to as to style and content by: Hans A. Schuessler (Chair of Committee) David H. Russell (Member) Glenn A...
Neutron Electric Dipole Moment Matt Eichenfield
Golwala, Sunil
Neutron Electric Dipole Moment (NEDM) Matt Eichenfield 04/20/2007 #12;P and T Violations EDM to explain the Baryonic asymmetry of the universe #12;The Neutron's Constituents Three quarks Two down (q d neutron radius, the separation causing the SM NEDM
NASA Astrophysics Data System (ADS)
Szaller, Dávid; Bordács, Sándor; Kocsis, Vilmos; Rõõm, Toomas; Nagel, Urmas; Kézsmárki, István
2014-05-01
We derive a sum rule to demonstrate that the static magnetoelectric (ME) effect is governed by optical transitions that are simultaneously excited by the electric and magnetic components of light. The ME sum rule is applicable to a broad class of materials lacking the spatial inversion and the time-reversal symmetries, including multiferroic compounds. Due to the dynamical ME effect, the optical excitations in these materials can exhibit directional dichroism, i.e., the absorption coefficient can be different for counter-propagating light beams. According to the ME sum rule, the magnitude of the linear ME effect of a material is mainly determined by the directional dichroism of its low-energy optical excitations. An application of the sum rule to the multiferroic Ba2CoGe2O7, Sr2CoSi2O7, and Ca2CoSi2O7 shows that in these compounds the static ME effect is mostly governed by the directional dichroism of the spin-wave excitations in the giga-terahertz spectral range. On this basis, we argue that the studies of directional dichroism and the application of the ME sum rule promote the synthesis of new materials with large static ME effect.
Molecules with an induced dipole moment in a stochastic electric field
NASA Astrophysics Data System (ADS)
Band, Y. B.; Ben-Shimol, Y.
2013-10-01
The mean-field dynamics of a molecule with an induced dipole moment (e.g., a homonuclear diatomic molecule) in a deterministic and a stochastic (fluctuating) electric field is solved to obtain the decoherence properties of the system. The average (over fluctuations) electric dipole moment and average angular momentum as a function of time for a Gaussian white noise electric field are determined via perturbative and nonperturbative solutions in the fluctuating field. In the perturbative solution, 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 Gaussian white noise magnetic field. In the nonperturbative solution, the component of the average electric dipole moment and the average angular momentum in the deterministic electric field direction also decay to zero.
Ac loss measurement of SSC dipole magnets
S. Delchamps; R. Hanft; T. Jaffery; W. Kinney; W. Koska; M. J. Lamm; P. O. Mazur; D. Orris; J. P. Ozelis; J. Strait; M. Wake
1992-01-01
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
Magnetic field properties of the ISABELLE Project superconducting dipole magnets
Kirk, H.G.; Engelmann, R.; Herrera, J.; Jaeger, K.; Robins, K.; Willen, E.
1981-01-01
A series of prototype superconducting dipole magnets have been constructed and tested as part of the ISABELLE Project research and development program. Results of magnetic field measurements are presented with emphasis placed on the DC and AC components of the main field. Magnetization and the effects of the magnetic fields at the ends of the magnet are displayed.
Electric Dipole Moments of Alkali Atoms. A Limit to the Electric Dipole Moment of the Free Electron
J. P. Carrico; E. Lipworth; P. G. Sandars; T. S. Stein; M. C. Weisskopf
1968-01-01
The observation of an electric dipole moment (EDM) in an atomic system of well-defined angular momentum would be direct evidence for violations of both parity and time-reversal invariances. A search has been made for an EDM in the cesium atom, using an atomic-beam magnetic-resonance technique. A large 25-cps voltage is applied across two parallel metal plates situated between the loops
T. S. Stein; J. P. Carrico; E. Lipworth; M. C. Weisskopf
1969-01-01
An atomic-beam magnetic-resonance apparatus has been employed to search for a linear Stark effect on the flop-in Zeeman transition (F=4, mF=-4)(F=4, mF=-3) of the ground state of the cesium atom. Such an effect could be interpreted in terms of a permanent electric dipole moment (EDM) of the cesium atom. The existence of an EDM in a nondegenerate physical system having
Magnetic Dipole Microwave Emission from Dust Grains
Draine, B T
1999-01-01
Thermal fluctuations in the magnetization of interstellar grains will produce magnetic dipole emission at frequencies below ~100 GHz. We show how to calculate absorption and emission from small particles composed of magnetic materials. The Kramers-Kronig relations for a dusty medium are generalized to include the possibility of magnetic grains. The frequency-dependent magnetic permeability is discussed for candidate grain materials, including iron and magnetite. We calculate emission spectra for various interstellar grain candidates. While paramagnetic grains or magnetite grains cannot account for the observed "anomalous" emission from dust in the 14-90 GHz range, stronger magnetic dipole emission will result if a fraction of the grain material is ferromagnetic, as could be the case given the high Fe content of interstellar dust. The observed emission from dust near 90 GHz implies that not more than 5% of interstellar Fe is in the form of metallic iron grains or inclusions (e.g., in "GEMS"). However, we show ...
Savukov, I; Matlashov, A; Volegov, P; Espy, M; Cooper, M
2008-12-01
The precession of (3)He spins is detected with ultra-low field NMR. The absolute strength of the NMR signal is accurately measured and agrees closely with theoretical calculations. The sensitivity is analyzed for applications to a neutron electric dipole moment (nEDM) fundamental symmetry experiment under development. PMID:18835204
NASA Astrophysics Data System (ADS)
Savukov, I.; Matlashov, A.; Volegov, P.; Espy, M.; Cooper, M.
2008-12-01
The precession of 3He spins is detected with ultra-low field NMR. The absolute strength of the NMR signal is accurately measured and agrees closely with theoretical calculations. The sensitivity is analyzed for applications to a neutron electric dipole moment (nEDM) fundamental symmetry experiment under development.
NASA Astrophysics Data System (ADS)
Balasubramanian, T. K.; Mishra, Adya P.; Kshirsagar, R. J.
2014-01-01
The recently measured magnetic dipole (M1) absorption intensities of rovibronic transitions in the A-band (b?g+1-X?g-3, 030 band) of 16O2 are theoretically analyzed employing a model in which the b?g+1:X?g-3 mutual perturbations are treated to a sufficient degree of accuracy. Effects of rotational perturbations became manifest in the data analysis and rovibronic correction parameters are needed to reconcile theory and experiment. At a subtle level there is evidence of Herman-Wallis (HW) type effect arising from vibration-rotation interaction in the b and X states. The functional form for the HW correction factor is arrived at from first principles. The final calculations reproduce the measured intensities to fraction of a percent, well within the measurement accuracy. The present analysis leads to the value
Incipient magnetic rotation? A magnetic dipole band in 104Cd
D. G. Jenkins; R. Wadsworth; J. A. Cameron; M. P. Carpenter; C. J. Chiara; R. M. Clark M. Devlin; P. Fallon; D. B. Fossan; I. M. Hibbert; R. V. F. Janssens; V. P. Janzen; R. Kruecken; D. R. LaFosse; G. J. Lane; T. Lauritsen; I. Y. Lee; A. O. Macchiavelli; C. M. Parry; D. G. Sarsantities; J. M. Sears; D. Seweryniak; J. F. Smith; K. Starosta; D. Ward; I. Wiedenhoever; A. N. Wilson; J. N. Wilson; S. Frauendorf
2000-07-05
High spin states of the nucleus 104Cd have been studied using the Gammapshere array. The level scheme for 104Cd has been revised and evidence for a structure consisting of magnetic dipole transitions is presented. Shell model calculations, published previously, are invoked to support an interpretation of this structure as an incpient case of magnetic rotation where the transversal magnetic dipole moment is not strong enough to break the signature symmetry.
Electric dipole moment of light nuclei
Gibson, Benjamin [Los Alamos National Laboratory; Afnan, I R [Los Alamos National Laboratory
2010-01-01
We examine the sensitivity of the deuteron Electric Dipole Moment (EDM) to variation in the nucleon-nucleon interaction. In particular, we write the EDM as a sum of two terms, one depends on the target wave function, the second on intermediate multiple scattering states in the {sup 3}P{sub 1} channel. This second contribution is sensitive to off-shell behavior of the {sup 3}P{sub 1} amplitude.
Electric dipole moment of light nuclei
Afnan, Iraj R. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001 (Australia); Gibson, Benjamin F. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2010-07-27
We examine the sensitivity of the deuteron Electric Dipole Moment (EDM) to variation in the nucleon-nucleon interaction. In particular, we write the EDM as a sum of two terms, one depends on the target wave function, the second on intermediate multiple scattering states in the {sup 3}P{sub 1} channel. This second contribution is sensitive to off-shell behavior of the {sup 3}P{sub 1} amplitude.
New measurements of neutron electric dipole moment
A. P. Serebrov; E. A. Kolomenskiy; A. N. Pirozhkov; I. A. Krasnoshekova; A. V. Vasiliev; A. O. Polyushkin; M. S. Lasakov; A. K. Fomin; I. V. Shoka; V. A. Solovey; O. M. Zherebtsov; P. Geltenbort; O. Zimmer; S. N. Ivanov; E. B. Alexandrov; S. P. Dmitriev; N. A. Dovator
2013-12-16
We report a new measurement of the neutron electric dipole moment with the PNPI EDM spectrometer using the ultracold neutron source PF2 at the research reactor of the ILL. Its first results can be interpreted as a limit on the neutron EDM of $|d_{\\rm n}| < 5.5 \\times 10^{-26} \\rm{e} \\cdot \\rm{cm}$ (90% confidence level).
Landau levels analog to electric dipole
NASA Astrophysics Data System (ADS)
Ribeiro, L. R.; Furtado, Claudio; Nascimento, J. R.
2006-01-01
In this Letter we study the quantum dynamics of a neutral particle in the presence of an external magnetic field. We demonstrate in a specific field-dipole configuration that we have a quantization similar to the Landau levels. We investigate this quantization motivated by the recent analysis of Landau Aharonov Casher (LAC) quantization of Ericsson and Sjöqvist [M. Ericsson, E. Sjöqvist, Phys. Rev. A 65 (2001) 013607]. The energy eigenfunction and eigenvalues are obtained.
Circular current loops, magnetic dipoles and spherical harmonic analysis.
Alldredge, L.R.
1980-01-01
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
Sur, Chiranjib; Chaudhuri, Rajat K. [Department of Astronomy, Ohio State University, Columbus, Ohio 43210 (United States); Indian Institute of Astrophysics, Koramangala, Block II, Bangalore 560 034 (India)
2007-09-15
Searching for an accurate optical clock which can serve as a better time standard than the present-day atomic clock is highly demanding from several areas of science and technology. Several attempts have been made to build more accurate clocks with different ion species. In this paper, we discuss the electric quadrupole and hyperfine shifts in the 5d{sup 9}6s{sup 2} {sup 2}D{sub 5/2}(F=0,m{sub F}=0){r_reversible}5d{sup 10}6s {sup 2}S{sub 1/2}(F=2,m{sub F}=0) clock transition in {sup 199}Hg{sup +}, one of the most promising candidates for next-generation optical clocks. We have applied Fock-space unitary coupled-cluster theory to study the electric quadrupole moment of the 5d{sup 9}6s{sup 2} {sup 2}D{sub 5/2} state and magnetic dipole hyperfine constants of 5d{sup 9}6s{sup 2} {sup 2}D{sub 3/2,5/2} and 5d{sup 10}6s{sup 1} {sup 2}S{sub 1/2} states, respectively, of {sup 199}Hg{sup +}. We have also compared our results with available data. To the best of our knowledge, this is the first time a variant of coupled-cluster theories has been applied to study these kinds of properties of Hg{sup +} and is the most accurate estimate of these quantities to date.
The Submm and mm Excess of the SMC: Magnetic Dipole Emission from Magnetic Nanoparticles?
Draine, B T
2012-01-01
The Small Magellanic Cloud (SMC) has surprisingly strong submm and mm-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 gamma-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.
NASA Astrophysics Data System (ADS)
Draine, B. T.; Hensley, Brandon
2012-09-01
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.
Magnetic Dipole Microwave Emission from Dust Grains
B. T. Draine; A. Lazarian
1998-07-01
Thermal fluctuations in the magnetization of interstellar grains will produce magnetic dipole emission at frequencies below ~100 GHz. We show how to calculate absorption and emission from small particles composed of magnetic materials. The Kramers-Kronig relations for a dusty medium are generalized to include the possibility of magnetic grains. The frequency-dependent magnetic permeability is discussed for candidate grain materials, including iron and magnetite. We calculate emission spectra for various interstellar grain candidates. While paramagnetic grains or magnetite grains cannot account for the observed "anomalous" emission from dust in the 14-90 GHz range, stronger magnetic dipole emission will result if a fraction of the grain material is ferromagnetic, as could be the case given the high Fe content of interstellar dust. The observed emission from dust near 90 GHz implies that not more than 5% of interstellar Fe is in the form of metallic iron grains or inclusions (e.g., in "GEMS"). However, we show that if most interstellar Fe is in a moderately ferromagnetic material, it could contribute a substantial fraction of the observed 14-90 GHz emission, perhaps comparable to the contribution from spinning ultrasmall dust grains. The two emission mechanisms can be distinguished by measuring the emission from dark clouds. The expected polarization of magnetic dipole emission is discussed
The Case of the Disappearing Magnetic Dipole
ERIC Educational Resources Information Center
Gough, W.
2008-01-01
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…
Ac loss measurement of SSC dipole magnets
S. Delchamps; R. Hanft; T. Jaffery; W. Kinney; W. Koska; M. J. Lamm; P. O. Mazur; D. Orris; J. P. Ozelis; J. Strait; M. Wake
1992-01-01
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
Stability of superconducting ISABELLE dipole magnets
Wipf, S.L.
1981-04-01
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.
Single-layer high field dipole magnets
Vadim V. Kashikhin and Alexander V. Zlobin
2001-07-30
Fermilab is developing high field dipole magnets for post-LHC hadron colliders. Several designs with a nominal field of 10-12 T, coil bore size of 40-50 mm based on both shell-type and block-type coil geometry are currently under consideration. This paper presents a new approach to magnet design, based on simple and robust single-layer coils optimized for the maximum field, good field quality and minimum number of turns.
Concentric Titled Double-Helix Dipole Magnets
Rainer Meinke; Carl Goodzeit; Millicent Ball
2003-01-01
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
Single-layer high field dipole magnets
Vadim V. Kashikhint; Alexander V. Zlobin
2001-01-01
Fermilab is developing high field dipole magnets for post-LHC hadron colliders. Several designs with a nominal field of 10-12 T, coil bore size of 40-50 mm based on both shell-type and block-type coil geometry are currently under consideration. This paper presents a new approach to magnet design, based on simple and robust single-layer coils optimized for the maximum field, good
Large muon electric dipole moment from flavor?
Hiller, Gudrun; Huitu, Katri; Rueppell, Timo; Laamanen, Jari [CERN, Theory Division, CH-1211 Geneva 23 (Switzerland) and Institut fuer Physik, Technische Universitaet Dortmund, D-44221 Dortmund (Germany); Department of Physics, and Helsinki Institute of Physics, FIN-00014 University of Helsinki (Finland); Theoretical High Energy Physics, Radboud University Nijmegen, P.O. Box 9010, NL-6500 GL Nijmegen (Netherlands)
2010-11-01
We study the prospects and opportunities of a large muon electric dipole moment (EDM) of the order (10{sup -24}-10{sup -22}) ecm. We investigate how natural such a value is within the general minimal supersymmetric extension of the standard model with CP violation from lepton flavor violation in view of the experimental constraints. In models with hybrid gauge-gravity-mediated supersymmetry breaking, a large muon EDM is indicative for the structure of flavor breaking at the Planck scale, and points towards a high messenger scale.
Revised cross section for RHIC dipole magnets
Thompson, P.A.; Gupta, R.C.; Kahn, S.A.; Hahn, H.; Morgan, G.H.; Wanderer, P.J.; Willen, E.
1991-01-01
Using the experience gained in designing and building Relativistic Heavy Ion Collider (RHIC) dipole prototype magnets an improved cross section has been developed. Significant features of this design include the use of only three wedges for field shaping and wedge cross sections which are sectors of an annulus. To aid in the understanding of the actual magnets, one has been sectioned, and detailed mechanical and photographic measurements made of the wire positions. The comparison of these measurements with the magnetic field measurements will is presented. 2 refs, 3 figs., 2 tabs.
Development of a simulation for measuring neutron electric dipole moment
NASA Astrophysics Data System (ADS)
Katayama, Ryo; Mishima, Kenji; Yamashita, Satoru; Sakurai, Dai; Kitaguchi, Masaaki; Yoshioka, Tamaki; Seki, Yoshichika
2014-07-01
The neutron electric dipole moment (nEDM) is sensitive to new physics beyond the standard model and could prove to be a new source of CP violation. Several experiments are being planned worldwide for its high-precision measurement. The nEDM is measured as the ultracold neutron (UCN) spin precession in a storage bottle under homogeneous electric and magnetic fields. In nEDM measurement, the systematic uncertainties are due to the motion of the UCNs, the geometry of the measurement system, and inhomogeneous electric and magnetic fields. Therefore, it is essential to quantitatively understand these effects in order to reduce them. Geant4UCN is an ideal simulation framework because it can compute the UCN trajectory, evaluate the time evolution of the spin precession due to arbitrary electric and magnetic fields, and define the storage geometry flexibly. We checked how accurately Geant4UCN can calculate the spin precession. We found that because of rounding errors, it cannot simulate it accurately enough for nEDM experiments, assuming homogeneous electric and magnetic fields with strengths of 10 kV/cm and 1 ?T, respectively, and 100 s of storage. In this paper, we report on its discrepancies and describe a solution.
Electron electric dipole moment experiment using electric-fieldquantized slow cesium atoms
Amini, Jason M.; Munger Jr., Charles T.; Gould, Harvey.
2007-04-05
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.
Instantaneous power radiated from magnetic dipole moments
NASA Astrophysics Data System (ADS)
Morley, P. D.; Buettner, D. J.
2015-03-01
We compute the power radiated per unit solid angle of a moving magnetic dipole moment, and its instantaneous radiated power, both non-relativistically and relativistically. This is then applied to various interesting situations: solar neutrons, electron synchrotrons and cosmological Dirac neutrinos. Concerning the latter, we show that hypothesized early-universe Big Bang conditions allow for neutrino radiation cooling and provide an energy loss-mechanism for subsequent neutrino condensation.
Instantaneous Power Radiated from Magnetic Dipole Moments
Peter D. Morley; Douglas J. Buettner
2014-07-04
We compute the power radiated per unit solid angle of a moving magnetic dipole moment, and its instantaneous radiated power, both non-relativistically and relativistically. This is then applied to various interesting situations: solar neutrons, electron synchrotrons and cosmological Dirac neutrinos. Concerning the latter, we show that hypothesized early-universe Big Bang conditions allow for neutrino radiation cooling and provide an energy loss-mechanism for subsequent neutrino condensation.
Magnetic field properties of SSC model dipole magnets
Wake, M.; Bossert, R.; Carson, J.; Delchamps, S.; Jaffery, T.S.; Kinney, W.; Koska, W.; Lamm, M.J.; Strait, J. (Fermi National Accelerator Lab., Batavia, IL (United States)); Butteris, J.; Sims, R.; Winters, M. (Superconducting Super Collider Lab., Dallas, TX (United States))
1992-09-01
SSC 1.5m model dipole magnets were built and tested at Fermilab. Magnetic field properties were studied in term of transfer function variation and multipole components. The results were satisfactory. Observation of periodicity of remanent field along the axis is also reported.
Magnetic field decay in model SSC dipoles
Gilbert, W.S.; Althaus, R.F.; Barale, P.J.; Benjegerdes, R.W.; Green, M.A.; Green, M.I.; Scanlan, R.M.
1988-08-01
We have observed that some of our model SSC dipoles have long time constant decays of the magnetic field harmonics with amplitudes large enough to result in significant beam loss, if they are not corrected. The magnets were run at constant current at the SSC injection field level of 0.3 tesla for one to three hours and changes in the magnetic field were observed. One explanation for the observed field decay is time dependent superconductor magnetization. Another explanation involves flux creep or flux flow. Data are presented on how the decay changes with previous flux history. Similar magnets with different Nb-Ti filament spacings and matrix materials have different long time field decay. A theoretical model using proximity coupling and flux creep for the observed field decay is discussed. 10 refs., 5 figs., 2 tabs.
Ac loss measurement of SSC dipole magnets
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
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.
A search for the electric dipole of the electron
Abdullah, K.F.
1989-08-01
We report a new upper limit on the electric dipole moment (EDM) of the electron of d{sub e} = 0.1 {plus minus} 3.2 {times} 10{sup {minus}26} e-cm. This precision is one hundred times better than any previously published limit and a factor of two better than that of unofficial reports. Recently there has been a great deal of theoretical interest in the possibility of a non-zero electron EDM. Models such as the left-right-symmetric Standard Model and an off-standard'' model with new heavy neutrinos are constrained by the new limit on d{sub e}. A non-zero electron EDM would violate the time reversal and parity space-time symmetries. T-violation was observed in neutral kaon decay and is still not fully explained by the Standard Model. Our experimental technique involves searching for an energy shift, linear in applied electric field, between the m{sub F} = 1 and m{sub F} = {minus}1 magnetic sublevels of the F=1 hyperfine level of the 6{sup 2}P{sub 1/2} ground state of atomic thallium. If the electron has a non-zero EDM, this thallium state will exhibit an atomic electric dipole moment that is roughly 600 times larger. The energy shift is detected with the technique of magnetic resonance spectroscopy, employing separated oscillating fields, applied to an atomic beam of thallium. In the approach, any relative phase-shift between the m{sub F} = {plus minus}1 components of the F=1 wavefunction acquired by the atom as it travels through an electric field is detected through interference with two separate oscillating magnetic fields located on either side of the electric field. The new level of precision is achieved through several improvements on previous experiments including employment of a vertical apparatus, two opposing atomic beams, and optical pumping for atomic state selection and analysis.
Fracture detection using a grounded subsurface vertical electric dipole
Zhou, Q.; Lee, K.H.; Goldstein, N.E.; Morrison, H.F.; Becker, A.
1986-08-01
In this paper we study the scattered magnetic field above the surface of the earth due to a buried sheet-like conductor excited by a grounded and oscillating vertical electric dipole (G.V.E.D.) in the earth. The significance of this technique for the detection of water-filled fractures is that there is no magnetic field in the air, assuming that the displacement current is negligible, so long as the G.V.E.D. source is buried in a layered half-space. If any signal is detected it must be due to the presence of a 2-D or 3-D inhomogeneity, such as a sheet-like conductor. Using a numerical modeling approach, we calculated the strength and anomaly shape of the secondary magnetic field from the sheet to determine a G.V.E.D. is a suitable source detecting a major conductive fracture zone.
Spherical Bondi accretion onto a magnetic dipole
Yu. M. Toropin; O. D. Toropina; M. M. Romanova; V. V. Savelyev; V. M. Chechetkin; R. V. E. Lovelace
1998-11-17
Quasi-spherical supersonic (Bondi-type) accretion to a star with a dipole magnetic field is investigated using resistive magnetohydrodynamic simulations. A systematic study is made of accretion to a non-rotating star, while sample results for a rotating star are also presented. A new stationary subsonic accretion flow is found with a steady rate of accretion to the magnetized star smaller than the Bondi accretion rate. Dependences of the accretion rate and the flow pattern on the magnetic momentum of the star and the magnetic diffusivity are presented. For slow star's rotation the accretion flow is similar to that in non-rotating case, but in the case of fast rotation the structure of the subsonic accretion flow is fundamentally different and includes a region of ``propeller'' outflow. The methods and results described here are of general interest and can be applied to systems where matter accretes with low angular momentum.
New measurements of the neutron electric dipole moment
NASA Astrophysics Data System (ADS)
Serebrov, A. P.; Kolomenskiy, E. A.; Pirozhkov, A. N.; Krasnoschekova, I. A.; Vassiljev, A. V.; Polushkin, A. O.; Lasakov, M. S.; Fomin, A. K.; Shoka, I. V.; Solovey, V. A.; Zherebtsov, O. M.; Geltenbort, P.; Ivanov, S. N.; Zimmer, O.; Alexandrov, E. B.; Dmitriev, S. P.; Dovator, N. A.
2014-03-01
We report a new measurement of the neutron electric dipole moment with the PNPI EDM spectrometer using the ultracold neutron source PF2 at the research reactor of the ILL. Its first results can be interpreted as a limit on the neutron electric dipole moment of | d n | < 5.5 × 10-26 e cm (90% confidence level).
Magnetic field fluctuations in SC dipole magnet
Vladimir Shiltsev et al.
2001-08-15
Magnetic field fluctuations at the betatron frequency can lead to emittance growth in circular accelerators. Tolerances are extremely tight for large hadron colliders like LHC and VLHC[1]. We performed experimental studies of the fluctuations in a stand-alone superconducting Tevatron magnet. Here we give a general description of the experimental set-up, present main results and discuss consequences for the colliders.
Search for the Neutron Electric Dipole Moment
Plaster, Brad [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States)
2010-08-04
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'.
Nuclear Electric Dipole Moment of 3He
I. Stetcu; C. -P. Liu; J. L. Friar; A. C. Hayes; P. Navratil
2008-04-23
A permanent electric dipole moment (EDM) of a physical system requires time-reversal (T) and parity (P) violation. Experimental programs are currently pushing the limits on EDMs in atoms, nuclei, and the neutron to regimes of fundamental theoretical interest. Here we calculate the magnitude of the PT-violating EDM of 3He and the expected sensitivity of such a measurement to the underlying PT-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. Our results suggest that a measurement of the 3He EDM is complementary to the planned neutron and deuteron experiments, and could provide a powerful constraint for the theoretical models of the pion-nucleon PT-violating interaction.
Magnetic Dipole Interaction on a Square Lattice
NASA Astrophysics Data System (ADS)
Zabel, Hartmut; Ewerlin, Melanie; Demirbas, Derya; Bruessing, Frank; Kronast, Florian
2013-03-01
We have studied interactions and phase transitions of circular magnetic islands with dipole character on a square lattice. By lithographic means we have prepared square patterns of periodicity 300 nm decorated with circular islands of 150 nm diameter using Pd0.87Fe0.13 as magnetic alloy. Below the Curie temperature of 260 K each island is in a ferromagnetic, single domain state with dipolar character and zero in-plane anisotropy. Below a second transition temperature the dipoles start to interact. MOKE measurements show a characteristic change in the magnetic hysteresis for temperatures below 160 K with increasing coercivity for decreasing temperatures. Furthermore, below the second transition the in-plane hysteresis becomes anisotropic, having an easy axis along [10] direction and a hard axis along [11] direction. SPEEM experiments at BESSY II of the HZB with circularly polarized incident photons tuned to the Fe L3 - edge show clearly the development of dipolar chains below the second phase transition that increase in length with decreasing temperature. Neighbouring chains are found to be oriented parallel as well as antiparallel. We have studied interactions and phase transitions of circular magnetic islands with dipole character on a square lattice. By lithographic means we have prepared square patterns of periodicity 300 nm decorated with circular islands of 150 nm diameter using Pd0.87Fe0.13 as magnetic alloy. Below the Curie temperature of 260 K each island is in a ferromagnetic, single domain state with dipolar character and zero in-plane anisotropy. Below a second transition temperature the dipoles start to interact. MOKE measurements show a characteristic change in the magnetic hysteresis for temperatures below 160 K with increasing coercivity for decreasing temperatures. Furthermore, below the second transition the in-plane hysteresis becomes anisotropic, having an easy axis along [10] direction and a hard axis along [11] direction. SPEEM experiments at BESSY II of the HZB with circularly polarized incident photons tuned to the Fe L3 - edge show clearly the development of dipolar chains below the second phase transition that increase in length with decreasing temperature. Neighbouring chains are found to be oriented parallel as well as antiparallel. This work was supported by DFG-SFB 491 and BMBF under contracts 05K10PC2 and 05ES3xBA/5
NSDL National Science Digital Library
In this two-part activity, students learn about electromagnetism by constructing electromagnets and observing their behavior. They will discover that there is a close relationship between electricity and magnetism in that moving magnets can induce electric currents and that electric currents can cause magnetism. They also learn that electric current flowing in a wire creates a magnetic field around it.
Prospects for 10T accelerator dipole magnets
Taylor, C.E.; Meuser, R.B.
1981-03-01
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.
Magnetic dipole discharges. I. Basic properties
Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)] [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States); Teodorescu-Soare, C. T.; Ionita, C.; Schrittwieser, R. [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)] [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)
2013-08-15
A simple discharge is described which uses a permanent magnet as a cold cathode and the metallic chamber wall as an anode. The magnet's equator is biased strongly negative, which produces secondary electrons due to the impact of energetic ions. The emitted electrons are highly confined by the strong dipolar magnetic field and the negative potential in the equatorial plane of the magnet. The emitted electrons ionize near the sheath and produce further electrons, which drift across field lines to the anode while the nearly unmagnetized ions are accelerated back to the magnet. A steady state discharge is maintained at neutral pressures above 10{sup ?3} mbar. This is the principle of magnetron discharges, which commonly use cylindrical and planar cathodes rather than magnetic dipoles as cathodes. The discharge properties have been investigated in steady state and pulsed mode. Different magnets and geometries have been employed. The role of a background plasma has been investigated. Various types of instabilities have been observed such as sheath oscillations, current-driven turbulence, relaxation instabilities due to ionization, and high frequency oscillations created by sputtering impulses, which are described in more detail in companion papers. The discharge has also been operated in reactive gases and shown to be useful for sputtering applications.
Neutron electric dipole moment on the lattice
Eigo Shintani; S. Aoki; N. Ishizuka; K. Kanaya; Y. Kikukawa; Y. Kuramashi; M. Okawa; A. Ukawa; T. Yoshié
2005-09-26
We carry out a feasibility study toward a lattice QCD calculation of the neutron electric dipole moment (NEDM) in the presence of the $\\theta$ term using two different approaches. In the first method, we calculate the CP-odd electromagnetic form factor $F_3$, which becomes the NEDM in the zero momentum transfer limit. At the first order in $\\theta$, we derive a formula connecting the lattice three-point function to the CP-odd electromagnetic form factor. In the second method we directly extract the NEDM from the energy difference between spin-up and spin-down neutron states in the presence of a constant electric field, without expanding a small but non-zero $\\theta$. We test both approaches numerically, employing the domain-wall quark action with the RG improved gauge action in quenched QCD at $a^{-1}\\simeq 2$ GeV on a $16^3\\times 32\\times 16$ lattice, and further applying the second method to the clover quark action at a similar lattice spacing and nucleon mass. We obtain good signals from both approaches. In particular the second method works well with both fermion formulations.
Space propulsion by fusion in a magnetic dipole
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
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.
Pair Cascades and Deathlines in Offset Magnetic Dipole Fields
NASA Technical Reports Server (NTRS)
Harding, Alice; Muslimov, Alex
2010-01-01
We investigate electron-positron pair cascades in a dipole magnetic field whose axis is offset from the neutron star center. In such a field geometry, the polar cap is displaced from the neutron star symmetry axis and the field line radius of curvature is modified. Using the modified parallel electric field near the polar cap of an offset dipole, we simulate pair cascades to determine the pair deathlines and pair multiplicities as a function of the offset parameter. We find that the pair multiplicity can change dramatically with a modest offset, with a significant increase on one side of the polar cap. Lower pair deathlines allow a larger fraction of the pulsar population, that include old and millisecond pulsars, to produce cascades with high multiplicity.
Electric-dipole-induced universality for Dirac fermions in graphene.
De Martino, Alessandro; Klöpfer, Denis; Matrasulov, Davron; Egger, Reinhold
2014-05-01
We study electric dipole effects for massive Dirac fermions in graphene and related materials. The dipole potential accommodates towers of infinitely many bound states exhibiting a universal Efimov-like scaling hierarchy. The dipole moment determines the number of towers, but there is always at least one tower. The corresponding eigenstates show a characteristic angular asymmetry, observable in tunnel spectroscopy. However, charge transport properties inferred from scattering states are highly isotropic. PMID:24856711
Concentric Titled Double-Helix Dipole Magnets
Rainer Meinke, Ph.D; Carl Goodzeit; Millicent Ball, Ph.D
2003-09-05
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.
Possible Constraints on Neutron Electric Dipole Moment from Pulsar Radiation
C. Sivaram
2010-02-12
Even if only a small fraction of neutron dipole moments are aligned in a neutron star, observed pulsar radiation loses provide a stringent limit on the neutron electric dipole moment of <10-29 ecm, more stringent than best current experimental limits.
Nuclear Electric Dipole Moment of 3He
Stetcu, I; P.Liu, C; Friar, J L; Hayes, A C; Navratil, P
2008-04-08
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.
The search for permanent electric dipole moments
Kirch, Klaus [PSI-Villigen - ETH Zürich
2013-02-13
Permanent electric dipole moments (EDMs) of fundamental systems with spin - particles, nuclei, atoms or molecules violate parity and time reversal invariance. Invoking the CPT theorem, time reversal violation implies CP violation. Although CP-violation is implemented in the standard electro-weak theory, EDM generated this way remain undetectably small. However, this CP-violation also appears to fail explaining the observed baryon asymmetry of our universe. Extensions of the standard theory usually include new sources of CP violation and often predict sizeable EDMs. EDM searches in different systems are complementary and various efforts worldwide are underway and no finite value has been established yet. The prototype of an EDM search is the pursuit of the EDM of the neutron. It has the longest history and at the same time is at the forefront of present research. The talk aims at giving an overview of the field with emphasis on our efforts within an international collaboration at PSI, nedm.web.psi.ch.
Electric dipole moments in the MSSM reloaded
NASA Astrophysics Data System (ADS)
Ellis, John; Lee, Jae Sik; Pilaftsis, Apostolos
2008-10-01
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.
Nucleon tensor charges and electric dipole moments
Mario Pitschmann; Chien-Yeah Seng; Craig D. Roberts; Sebastian M. Schmidt
2014-12-22
A symmetry-preserving Dyson-Schwinger equation treatment of a vector-vector contact interaction is used to compute dressed-quark-core contributions to the nucleon $\\sigma$-term and tensor charges. The latter enable one to directly determine the effect of dressed-quark electric dipole moments (EDMs) on neutron and proton EDMs. The presence of strong scalar and axial-vector diquark correlations within ground-state baryons is a prediction of this approach. These correlations are active participants in all scattering events and thereby modify the contribution of the singly-represented valence-quark relative to that of the doubly-represented quark. Regarding the proton $\\sigma$-term and that part of the proton mass which owes to explicit chiral symmetry breaking, with a realistic $d$-$u$ mass splitting the singly-represented $d$-quark contributes 37% more than the doubly-represented $u$-quark; and in connection with the proton's tensor charges, $\\delta_T u$, $\\delta_T d$, the ratio $\\delta_T d/\\delta_T u$ is 18% larger than anticipated from simple quark models. Of particular note, the size of $\\delta_T u$ is a sensitive measure of the strength of dynamical chiral symmetry breaking; and $\\delta_T d$ measures the amount of axial-vector diquark correlation within the proton, vanishing if such correlations are absent.
QED vacuum fluctuations and induced electric dipole moment of the neutron
C. A. Dominguez; H. Falomir; M. Ipinza; S. Kohler; M. Loewe; J. C. Rojas
2009-08-05
Quantum fluctuations in the QED vacuum generate non-linear 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 non-linearity in QED.
QED vacuum fluctuations and induced electric dipole moment of the neutron
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
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.
Theoretical electric dipole moments of SiH, GeH and SnH
NASA Technical Reports Server (NTRS)
Pettersson, L. G. M.; Langhoff, S. R.
1986-01-01
Accurate theoretical dipole moments have been computed for the X2Pi ground states of Si(-)H(+) (0.118 D), Ge(+)H(-) (0.085 D), and Sn(+)H(-) (0.357 D). The trend down the periodic table is regular and follows that expected from the electronegativities of the group IV atoms. The dipole moment of 1.24 + or - 0.1 D for GeH recently derived by Brown, Evenson and Sears (1985) from the relative intensities of electric and magnetic dipole transitions in the 10-micron spectrum of the X2Pi state is seriously questioned.
Theoretical Electric Dipole Moments of SiH, GeH and SnH
NASA Technical Reports Server (NTRS)
Pettersson, Lars G. M.; Langhoff, Stephen R.
1986-01-01
Accurate theoretical dipole moments (mu(sub c) have been computed for the X(exp 2)Pi ground states of Si(-)H(+)(0.118 D), Ge(+)H(-)(0.085 D) and Sn(+)H(-)(0.357 D). The trend down the periodic table is regular and follows that expected from the electronegativities of the group IV atoms. The dipole moment of 1.24 +/- 0.1 D for GeH recently derived by Brown, Evenson and Sears from the relative intensities of electric and magnetic dipole transitions in the 10 microns spectrum of the X(exp 2)Pi state is seriously questioned.
Symmetric Injection of High Beta Plasma into a Magnetic Dipole
NASA Astrophysics Data System (ADS)
Giersch, Louis; Winglee, Robert; Slough, John; Ziemba, Tim; Euripides, Peter
2003-10-01
Dipole confinement is a critical issue for several plasma devices, including the magnetic levitated dipole experiment for fusion applications, and mini-magnetospheric plasma propulsion for spacecraft applications. In this paper we investigate confinement of plasma within a magnetic dipole as functions of chamber neutral pressure and external magnetic field. The dipole plasma is created by the symmetric injection of high beta plasma into the equator of the dipole. The injection uses 8 cascaded arc plasma sources arranged at 45-degree increments around the magnet. The electron temperature, magnetic perturbations, and 3D measurements of the plasma density as a function of time are presented. Plasma losses on feed throughs are a significant sink of plasma. Nevertheless plasma with beta of order unity can be attained and confinement is seen out to several times the Bohm diffusion limit.
Comment on "Axion induced oscillating electric dipole moments"
Flambaum, V V; Stadnik, Y V
2015-01-01
In the recent work of Hill [Phys. Rev. D 91, 111702(R) (2015)], it is claimed that the axion electromagnetic anomaly induces an oscillating electron electric dipole moment of frequency $m_a$ and strength $\\sim 10^{-32}~e$ cm, in the limit $v/c \\to 0$ for the axion field. Here, we demonstrate that a proper treatment of this problem in the lowest order yields no electric dipole moment of the electron in the same limit.
New insights into the neutron electric dipole moment
K. Ottnad; B. Kubis; U. -G. Meißner; F. -K. Guo
2010-03-29
We analyze the CP-violating electric dipole form factor of the nucleon in the framework of covariant baryon chiral perturbation theory. We give a new upper bound on the vacuum angle, |\\theta_0| \\lesssim 2.5 \\cdot 10^{-10}. The quark mass dependence of the electric dipole moment is discussed and compared to lattice QCD data. We also perform the matching between its representations in the three- and two-flavor theories.
Heat leak performance of SSC collider dipole magnets
Weisend, J.G. II; Levin, M.; Franks, D.; Pletzer, R.; Augustynowicz, S.; McInturff, A.D. [Superconducting Super Collider Lab., Dallas, TX (United States); Boroski, W.B. [Fermi National Accelerator Lab., Batavia, IL (United States)
1993-09-01
The large number of superconducting dipoles in the SSC results in a stringent heat leak budget for each dipole. Ensuring that the dipoles meet this budget is vital to the successful operation or the collider. This work surveys heat leak measurements taken during 4 different magnet string tests. These tests involved both 40 mm and SO mm aperture dipoles. In these experiments the heat leak to the 80 K shield, 20 K shield and cold mass are measured. The results are compared to predictions from a computational thermal model of the dipole cryostat. Discrepancies are seen between the predicted and measured values. Possible explanations for these discrepancies are given.
NASA Astrophysics Data System (ADS)
Bast, Radovan; Saue, Trond; Henriksson, Johan; Norman, Patrick
2009-01-01
The quadratic response function has been derived and implemented at the adiabatic four-component Kohn-Sham density functional theory level with inclusion of noncollinear spin magnetization and gradient corrections in the exchange-correlation functional—a work that is an extension of our previous report where magnetization dependencies in the exchange-correlation functional were ignored [J. Henriksson, T. Saue, and P. Norman, J. Chem. Phys. 128, 024105 (2008)]. The electric-field induced second-harmonic generation experiments on CF3Cl and CF3Br are addressed by a determination of ?¯(-2?;?,?) for a wavelength of 694.3 nm, and the same property is also determined for CF3I. The relativistic effects on the static hyperpolarizability for the series of molecules amount to 1%, 5%, and 9%, respectively. At the experimental wavelength, the contributions to ? due to the magnetization dependence in the exchange-correlation functional are negligible for CF3Cl and CF3Br and small for CF3I. The noticeable effect of magnetization in the latter case is attributed to a near two-photon resonance with the excited state 1 E3 (nonrelativistic notation). It is emphasized, however, that the effect of magnetization on ? for CF3I is negligible both in comparison to the total relativistic correction as well as to the effects of electron correlation. It is concluded that, in calculations of hyperpolarizabilities under nonresonant conditions, the magnetization dependence in the exchange-correlation functional may be ignored.
Determination of the Delta++ magnetic dipole moment
G. Lopez Castro; A. Mariano
2001-06-26
We study the elastic and radiative pi+ p scattering within a full dynamical model which incorporates the finite width effects of the Delta++. The scattering amplitudes are invariant under contact transformations of the spin 3/2 field and gauge-invariance is fulfilled for the radiative case. The pole parameters of the Delta++ obtained from the elastic cross section are m_Delta = 1211.2 \\pm 0.4 MeV and Gamma_Delta = 88.2 \\pm 0.4 MeV. From a fit to the most sensitive observables in radiative pi+ p scattering, we obtain mu_Delta = 6.14 \\pm 0.51 e/2m_p for the magnetic dipole moment of the Delta++.
K. B. Maracas
1994-01-01
Increasing electrification brings increased human exposures to electric and magnetic fields, commonly called EMFs, and growing evidence suggests that exposure to even low frequency, low energy, electric and magnetic fields may be related to adverse health effects. This paper focuses on magnetic fields and strategies that address them. The challenges faced by scientists in understanding magnetic field interactions with humans,
Dipole Magnet from High Tc Superconductor
NASA Astrophysics Data System (ADS)
Nielsen, Gunver; Zangenberg, Nikolaj; Hazelton, Drew; Hauge, Nils; Nielsen, Bjarne Roger; Møller, Søren Pape; Baurichter, Arnd
The applicability of second-generation high-temperature superconductors (HTS) made from YBCO coated conductors in accelerator magnet technology was demonstrated by a consortium under the lead of Danfysik. A 3T demonstrator dipole magnet was designed, built and tested by the consortium. In total 2.5 km HTS tape was manufactured and tested by SuperPower. The tape was delivered in spool lengths 0varying from 93 m to 172 m and had a minimum Ic of 115 A or more. The tape was insulated with a 0.025 mm thin epoxy film before winding in total 14 saddle coils and 4 racetrack coils and subsequent impregnation with epoxy. All coils were azimuthally arranged in an ellipse configuration in order to achieve a cosine-theta-like current distribution around a circular good field with a diameter of 52 mm and a magnetic field length of 250 mm. The cold-mass consisting of the coil arrangement clamped in between a steel substrate and an aluminum collar and a surrounding laminated iron yoke, was mounted in a cryostat. The cold-mass is contact-cooled by two GM cryocoolers
Analysis and design of short, iron-free dipole magnets
Harvey, A.R.
1981-10-21
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.
NASA Astrophysics Data System (ADS)
Gao, Y. J.; Guo, Y. J.; Liu, J.-M.
2012-03-01
A double-domain model with long-range dipole-dipole interaction is proposed to investigate the self-oscillation of magnetization in nano-magnetic systems driven by self-controlled spin-polarized current. The dynamic behavior of magnetization oscillation is calculated by a modified Landau-Lifshitz-Gilbert equation in order to evaluate the effects of the long-range dipole-dipole interaction. While the self-oscillation of magnetization can be maintained substantially, several self-oscillation regions are experienced as the dipole-dipole interaction increases gradually.
Calculation of the magnetic field due to a bioelectric current dipole in an ellipsoid
Andrei Irimia
2008-01-01
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
New Experimental Limit on the Electric Dipole Moment of the Neutron
P. G. Harris; C. A. Baker; K. Green; P. Iaydjiev; S. Ivanov; D. J. R. May; J. M. Pendlebury; D. Shiers; K. F. Smith; M. van der Grinten; P. Geltenbort
1999-01-01
The latest neutron electric dipole moment (EDM) experiment has been collecting data at the Institut Laue-Langevin (ILL), Grenoble, since 1996. It uses an atomic-mercury magnetometer to compensate for the magnetic field fluctuations that were the principal source of systematic errors in previous experiments. The first results, in combination with the previous ILL measurement, yield a possible range of values of
NASA Astrophysics Data System (ADS)
Tarnovsky, V.; Bunimovicz, M.; Vuškovi?, L.; Stumpf, B.; Bederson, B.
1993-03-01
The average static (dc) electric dipole polarizabilities of the NaK and KCs heteronuclear alkali dimers have been measured, and those of the homonuclear molecules remeasured using molecular beam deflection in an inhomogeneous electric field. A congruent magnetic field enabled removal of the monomer constituents of the beam. The resulting deflection curves reflect both the permanent electric dipole force (for the heteronuclear dimers only), and the induced (polarizability) dipole force. It is assumed that the molecular constituents of the beam possess modified Maxwell-Boltzmann velocity and rotational state distributions. A Mach number is introduced to describe the sonic beam properties. The data analysis consists of a two-parameter least squares best fit of the experimental deflection curves to computed ones, the parameters being the polarizability and the Mach number. Values of the permanent heteronuclear dipole moments are taken from the literature. The obtained static electric dipole polarizabilities in units of (Å3) are 34±3 for Li2 (948 K), 40±3 for Na2 (676 K), 77±6 for K2 (542 K), 79±6 for Rb2 (527 K), 104±8 for Cs2 (480 K), 51±3 for NaK (612 K), and 89±5 for KCs (488 K). Comparison with recent calculations as well as earlier measurements of the homonuclear species are given. Two empirical rules are proposed for determining polarizabilities and dipole moments of heteronuclear molecules.
Electric lines of force of an electrically small dipole-loop antenna array
P. L. Overfelt
1998-01-01
The electric lines of force of an electrically small dipole-loop antenna array have been determined analytically for both the near- and far-fields of the array. It has been found that the behavior of the families of electric contours are dependent upon a coupling parameter, which is the ratio of the loop and dipole sizes and currents. This parameter also controls
NASA Astrophysics Data System (ADS)
Dey, C. C.; Srivastava, S. K.
2013-10-01
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.
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.
Neutron electric dipole moment from lattice QCD
E. Shintani; S. Aoki; N. Ishizuka; K. Kanaya; Y. Kikukawa; Y. Kuramashi; M. Okawa; Y. Tanigchi; A. Ukawa; T. Yoshié
2005-08-01
We carry out a feasibility study for the lattice QCD calculation of the neutron electric dipole moment (NEDM) in the presence of the $\\theta$ term. We develop the strategy to obtain the nucleon EDM from the CP-odd electromagnetic form factor $F_3$ at small $\\theta$, in which NEDM is given by $\\lim_{q^2\\to 0}\\theta F_3(q^2)/(2m_N)$ where $q$ is the momentum transfer and $m_N$ is the nucleon mass. We first derive a formula which relates $F_3$, a matrix element of the electromagnetic current between nucleon states, with vacuum expectation values of nucleons and/or the current. In the expansion of $\\theta$, the parity-odd part of the nucleon-current-nucleon three-point function contains contributions not only from the parity-odd form factors but also from the parity-even form factors multiplied by the parity-odd part of the nucleon two-point function, and therefore the latter contribution must be subtracted to extract $F_3$. We then perform an explicit lattice calculation employing the domain-wall quark action with the RG improved gauge action in quenched QCD at $a^{-1}\\simeq 2$ GeV on a $16^3\\times 32\\times 16$ lattice. At the quark mass $m_f a =0.03$, corresponding to $m_\\pi/m_\\rho \\simeq 0.63$, we accumulate 730 configurations, which allow us to extract the parity-odd part in both two- and three-point functions. Employing two different Dirac $\\gamma$ matrix projections, we show that a consistent value for $F_3$ cannot be obtained without the subtraction described above. We obtain $F_3(q^2\\simeq 0.58 \\textrm{GeV}^2)/(2m_N) =$ $-$0.024(5) $e\\cdot$fm for the neutron and $F_3(q^2\\simeq 0.58 \\textrm{GeV}^2)/(2m_N) =$ 0.021(6) $e\\cdot$fm for the proton.
First Computation of Parasitic Fields in LHC Dipole Magnet Interconnects
Devred, Arnaud; Boncompagni, Yann; Ferapontov, V; Koutchouk, Jean-Pierre; Russenschuck, Stephan; Sahner, T; Völlinger, C
2006-01-01
The Large Hadron Collider (LHC), now under construction at CERN, will rely on about 1600 main superconducting dipole and quadrupole magnets and over 7400 superconducting corrector magnets distributed around the eight sectors of the machine. Each magnet type is powered by dedicated superconducting busbars running along the sectors and mounted on the iron yokes of the main dipole and quadruple magnets. In the numerous magnet interconnects, the busbars are not magnetically shielded from the beam pipes and produce parasitic fields that can affect beam optics. We review the 3-D models that have been developed with ROXIE to compute the parasitic fields and we discuss their potential impacts on machine performance.
Electric dipole moment searches: reexamination of frequency shifts for particles in traps
Guillaume Pignol; Stephanie Roccia
2012-05-02
In experiments searching for a nonzero electric dipole moment of trapped particles, frequency shifts correlated with an applied electric field can be interpreted as a false signal. One such effect, referred to as the geometric phase effect, is known to occur in a magnetic field that is nonperfectly homogeneous. The increase in sensitivity of experiments demands improved theoretical description of this effect. In the case of fast particles, like atoms at room temperature and low pressure, the validity of established theories was limited to a cylindrical confinement cell in a uniform gradient with cylindrical symmetry. We develop a more general theory valid for an arbitrary shape of the magnetic field as well as for arbitrary geometry of the confinement cell. Our improved theory is especially relevant for experiments measuring the neutron electric dipole moment with an atomic comagnetometer. In this context, we have reproduced and extended earlier numerical studies of the geometric phase effect induced by localized magnetic impurities.
Gutierrez-Rodriguez, A.; Jayme-Valdes, B. [Facultad de Fisica, Universidad Autonoma de Zacatecas, Apartado Postal C-580, 98060 Zacatecas, Zacatecas (Mexico); Hernandez-Ruiz, M. A. [Facultad de Ciencias Quimicas, Universidad Autonoma de Zacatecas, Apartado Postal 585, 98060 Zacatecas, Zacatecas (Mexico); Perez, M. A. [Departamento de Fisica, CINVESTAV, Apartado Postal 14-740, 07000 Mexico D. F. (Mexico)
2006-09-01
We obtain bounds on the anomalous magnetic and electric dipole moments of the tau-neutrino through the reaction e{sup +}e{sup -}{yields}{nu}{nu}{gamma} at the Z{sub 1}-pole in the framework of a Left-Right symmetric model and a class of E{sub 6} inspired models with an additional neutral vector boson Z{sub {theta}}. We use the data collected by the L3 Collaboration at LEP. For the parameters of the E{sub 6} model we consider the mixing angle {theta}{sub E{sub 6}}=37.8 deg. and M{sub Z{sub {theta}}}=7M{sub Z{sub 1}}. We find that our bounds are of the same order of magnitude as those obtained in other extensions of the standard model.
NASA Astrophysics Data System (ADS)
Serebrov, A. P.; Kolomenskiy, E. A.; Pirozhkov, A. N.; Krasnoshekova, I. A.; Vasiliev, A. V.; Polyushkin, A. O.; Lasakov, M. S.; Murashkin, A. N.; Solovey, V. A.; Fomin, A. K.; Shoka, I. V.; Zherebtsov, O. M.; Geltenbort, P.; Ivanov, S. N.; Zimmer, O.; Alexandrov, E. B.; Dmitriev, S. P.; Dovator, N. A.
2015-03-01
This article presents results of measuring the neutron electric dipole moment (EDM) made by the Institut Laue-Langevin (ILL) reactor using the Petersburg Nuclear Physics Institute (PNPI) experimental installation. A double-chamber magnetic resonance spectrometer with prolonged holding of ultracold neutrons has been employed. The results determine the upper limit for EDM neutron quantity equal to | d n | < 5.5 × 10-26 e cm at a 90% confidence level.
a PbF Probe for the Electron Electric Dipole Moment
NASA Astrophysics Data System (ADS)
Moore-Furneaux, John; Shafer-Ray, N. E.
2011-06-01
A molecule in a state of total angular momentum F has a familiar 2F+1 degeneracy. In the presence of a pure magnetic field, this 2F+1 degeneracy is completely lifted with each magnetic sub-level M_F acquiring its own energy. In the presence of an electric field, quantum states with non-zero magnetic quantum numbers |M_F| remain doubly degenerate. This fact is well established by Stark spectroscopy and is a consequence of time-reversal symmetry. In 1950, Purcell and Ramsey pointed out that time-reversal symmetry could be broken by the existence of an electric dipole moment of the electron. Over the last 60 years, the interest in such a symmetry breaking dipole moment has increased, in part because it may explain the matter-antimatter asymmetry of the Universe, and in part because it could help to differentiate between competing fundamental models of Physics. If large enough, such a dipole moment could lead to an observable lifting of the degeneracy between +M_F and -M_F states of a molecule in a pure electric field. We report on progress toward searching for an electric dipole moment by an optical quantum beat experiment utilizing the X_1 ^2?1/2 state of PbF molecule.
Neutron Electric Dipole Moment Induced by the Strangeness Revisited
NASA Astrophysics Data System (ADS)
Fuyuto, Kaori; Hisano, Junji; Nagata, Natsumi
We evaluate the neutron electric dipole moment in the presence of the CP-violating operators up to dimension five based on the chiral perturbation theory. In the calculation, we apply the nucleon matrix elements of scalar-type quark operators obtained by the lattice QCD simulations. On the other hand, those of the dipole-type quark-gluon operators are evaluated by the QCD sum rules. The obtained resultant indicates that, though the quantity of strange quark in nucleon is small, the contribution of the chromoelectric dipole moment of that quark may be sizable.
Demonstration of a Cold Atom Fountain Electron Electric Dipole Moment Experiment
Jason M. Amini; Charles T. Munger Jr.; Harvey Gould
2006-03-14
A Cs fountain electron electric dipole moment (EDM) experiment using electric-field quantization is demonstrated. With magnetic fields reduced to 200 pT or less, the electric field lifts the degeneracy between hyperfine levels of different|mF| and, along with the slow beam and fountain geometry, suppresses systematics from motional magnetic fields. Transitions are induced and the atoms polarized and analyzed in field-free regions. The feasibility of reaching a sensitivity to an electron EDM of 2 x 10 exp(-50) C-m [1.3 x 10 exp(-29) e-cm] in a cesium fountain experiment is discussed.
An Improved Neutron Electric Dipole Moment Experiment
M. Ku?niak; I. Altarev; G. Ban; G. Bison; K. Bodek; M. Burghoff; M. Daum; K. Eberhardt; P. Fierlinger; E. Gutsmiedl; G. Hampel; W. Heil; R. Henneck; N. Khomutov; K. Kirch; St. Kistryn; S. Knappe-Grueneberg; A. Knecht; P. Knowles; J. V. Kratz; T. Lauer; B. Lauss; T. Lefort; A. Mtchedlishvili; O. Naviliat-Cuncic; S. Paul; A. S. Pazgalev; G. Petzold; C. Plonka-Spehr; G. Quéméner; D. Rebreyend; S. Roccia; G. Rogel; T. Sander-Thoemmes; A. Schnabel; N. Severijns; Yu. Sobolev; R. Stoepler; L. Trahms; M. Tur; A. Weis; N. Wiehl; J. Zejma; G. Zsigmond
2008-08-05
A new measurement of the neutron EDM, using Ramsey's method of separated oscillatory fields, is in preparation at the new high intensity source of ultra-cold neutrons (UCN) at the Paul Scherrer Institute, Villigen, Switzerland (PSI). The existence of a non-zero nEDM would violate both parity and time reversal symmetry and, given the CPT theorem, might lead to a discovery of new CP violating mechanisms. Already the current upper limit for the nEDM (|d_n|<2.9E-26 e.cm) constrains some extensions of the Standard Model. The new experiment aims at a two orders of magnitude reduction of the experimental uncertainty, to be achieved mainly by (1) the higher UCN flux provided by the new PSI source, (2) better magnetic field control with improved magnetometry and (3) a double chamber configuration with opposite electric field directions. The first stage of the experiment will use an upgrade of the RAL/Sussex/ILL group's apparatus (which has produced the current best result) moved from Institut Laue-Langevin to PSI. The final accuracy will be achieved in a further step with a new spectrometer, presently in the design phase.
Karim, Ishtak
2007-01-01
The Levitated Dipole Experiment (LDX) is the first experiment of its kind to use a levitated current ring to confine a plasma in a dipole magnetic field. Unlike most other confinement devices, plasma compressibility ...
Magnetic dipole moments of the heavy tensor mesons in QCD
Aliev, T M; Savc?, M
2015-01-01
The magnetic dipole moments of the ${\\cal D}_2$, and ${\\cal D}_{S_2}$, ${\\cal B}_2$, and ${\\cal B}_{S_2}$ heavy tensor mesons are estimated in framework of the light cone QCD sum rules. It is observed that the magnetic dipole moments for the charged mesons are larger than that of its neutral counterpart. It is found that the $SU(3)$ flavor symmetry violation is about 10\\% in both $b$ and $c$ sectors.
Test results for a Nb3Sn dipole magnet
A. F. Lietzke; R. Benjegerdes; S. Caspi; D. Dell'Orco; W. Harnden; A. D. McInturff; M. Morrison; R. M. Scanlan; C. E. Taylor; J. M. van Oort
1997-01-01
A cosine theta type dipole magnet using Nb3Sn conductor have been designed, built and tested. D19H is a two-layer dipole magnet with a Nb3Sn inner layer and a recycled NbTi outer layer. Coil-pairs are connected with two of the four Nb3Sn splices in a high field region, and compressed by a ring and collet system. The ramp-rate sensitivity and the
Mechanical Design of the SMC (Short Model Coil) Dipole Magnet
F. Regis; P. Manil; P. Fessia; M. Bajko; G. de Rijk
2010-01-01
The Short Model Coil (SMC) working group was set in February 2007 within the Next European Dipole (NED) program, in order to develop a short-scale model of a Nb3Sn dipole magnet. The SMC group comprises four laboratories: CERN\\/TE-MSC group (CH), CEA\\/IRFU (FR), RAL (UK) and LBNL (US). The SMC magnet was originally conceived to reach a peak field of about
Regular and chaotic orbits near a massive magnetic dipole
Ji?í Ková?; Ond?ej Kopá?ek; Vladimí Karas; Yasufumi Kojima
2013-01-09
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 Poincar\\'e 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 St\\"ormer'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.
Dual aperture dipole magnet with second harmonic component
Praeg, W.F.
1983-08-31
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.
Mercury monohalides: suitability for electron electric dipole moment searches.
Prasannaa, V S; Vutha, A C; Abe, M; Das, B P
2015-05-01
Heavy polar diatomic molecules are the primary tools for searching for the T-violating permanent electric dipole moment of the electron (eEDM). Valence electrons in some molecules experience extremely large effective electric fields due to relativistic interactions. These large effective electric fields are crucial to the success of polar-molecule-based eEDM search experiments. Here we report on the results of relativistic ab initio calculations of the effective electric fields in a series of molecules that are highly sensitive to an eEDM, the mercury monohalides (HgF, HgCl, HgBr, and HgI). We study the influence of the halide anions on E_{eff}, and identify HgBr and HgI as attractive candidates for future electric dipole moment search experiments. PMID:26000997
Mercury Monohalides: Suitability for Electron Electric Dipole Moment Searches
NASA Astrophysics Data System (ADS)
Prasannaa, V. S.; Vutha, A. C.; Abe, M.; Das, B. P.
2015-05-01
Heavy polar diatomic molecules are the primary tools for searching for the T -violating permanent electric dipole moment of the electron (eEDM). Valence electrons in some molecules experience extremely large effective electric fields due to relativistic interactions. These large effective electric fields are crucial to the success of polar-molecule-based eEDM search experiments. Here we report on the results of relativistic ab initio calculations of the effective electric fields in a series of molecules that are highly sensitive to an eEDM, the mercury monohalides (HgF, HgCl, HgBr, and HgI). We study the influence of the halide anions on Eeff, and identify HgBr and HgI as attractive candidates for future electric dipole moment search experiments.
Band, Yehuda B.
2013-01-01
PHYSICAL REVIEW E 88, 022127 (2013) Dynamics of an electric dipole moment in a stochastic electric 2013; published 15 August 2013) 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
Electricity and Magnetic Fields
NSDL National Science Digital Library
VU Bioengineering RET Program,
The grand challenge for this legacy cycle unit is for students to design a way to help a recycler separate aluminum from steel scrap metal. In previous lessons, they have looked at how magnetism might be utilized. In this lesson, students think about how they might use magnets and how they might confront the problem of turning the magnetic field off. Through the accompanying activity students explore the nature of an electrically induced magnetic field and its applicability to the needed magnet.
Origin of spontaneous electric dipoles in homonuclear niobium clusters.
Andersen, Kristopher E; Kumar, Vijay; Kawazoe, Yoshiyuki; Pickett, Warren E
2004-12-10
Surprisingly large, spontaneous electric dipole moments recently observed in homonuclear niobium clusters below 100 K are explained using first-principles electronic structure calculations. The calculated moments for Nb(n) (n < or =15) generally agree with the experimental data. A strong correlation is found between the geometrical asymmetry of the cluster and electric dipole: its magnitude is proportional to the spread in the principal moments of inertia and its direction aligns with the axis of the largest principal moment. Charge deformation densities reveal directional, partially covalent bonds that stabilize structural asymmetry. Classical simulations of the deflection of a cluster in a molecular beam reveal that the electronic dipole may persist at higher temperatures, but is masked by the rotational dynamics of the cluster. PMID:15697833
Electricity and Magnetism (1135-1225 Monday, Wednesday, Rutherford 115)
Lovejoy, Shaun
magnetic dipoles, Lorenz force law. 25% EM Fields in matter Be able to solve (static) problems involving change, check webCT. #12;Conservation lawsmagnetmagnet EM concept map Gauss's law Maxwell's equations (In, Guass's law, electric fields and potentials, work and energy, image methods, dipoles, quadrupoles. 2
NASA Astrophysics Data System (ADS)
Amrani, D.
2015-03-01
We propose a simple experiment to estimate the magnetic dipole moment of a neodymium disc magnet. The experiment employs a precision digital balance and a 1?m ruler to measure the force between two magnets. The magnetic dipole moment is determined from the slope of the magnetic force as a function of the inverse fourth power of the distance. The presented activity can be performed by teachers and students at college or university level to enhance their knowledge of the physics of magnetism.
Rotational transitions and electric dipole moment of fluorocarbene, HCF
NASA Astrophysics Data System (ADS)
Wagner, M.; Gamperling, M.; Braun, D.; Prohaska, M.; Hüttner, W.
2000-02-01
Microwave optical double resonance was used to determine the electric dipole moment components along the axes of inertia of the HCF molecule. The values are ?a=0.043(5) D, and ?b=1.402(6) D. Some of the rotational and centrifugal distortion constants, previously determined from Doppler limited optical spectra, were obtained with improved accuracy.
Neutron Electric Dipole Moment from Beyond the Standard Model
Tanmoy Bhattacharya; Vincenzo Cirigliano; Rajan Gupta
2012-12-20
We discuss the phenomenology of neutron Electric Dipole Moment from the Standard Model and beyond, and identify the matrix elements most necessary to connect the current and forthcoming experiments with phenomenology. We then describe lattice techniques for calculating these matrix elements
Electric Dipole Emission by Fulleranes and Galactic Anomalous Microwave Emission
Susana Iglesias-Groth
2005-01-01
We study the rotation rates and electric dipole emission of hydrogenated icosahedral fullerenes (single and multishell) in various phases of the interstellar medium. Using the formalism of Draine & Lazarian for the rotational dynamics of these molecules in various astrophysical environments, we find effective rotation rates in the range 1-65 GHz with a trend toward lower rotational frequency as the
Electric dipole moments of the nucleon and light nuclei
Andreas Wirzba
2014-04-24
The electric dipole moments of the nucleon and light ions are discussed and strategies for disentangling the underlying sources of CP violation beyond the Kobayashi-Maskawa quark-mixing mechanism of the Standard Model are indicated. Contribution to "45 years of nuclear theory at Stony Brook: a tribute to Gerald E. Brown".
Measuring magnetic dipole fields using Hall effects sensors
L. Benadero; J. A. Gorri; J. Villar; A. Albareda; E. Toribio; R. Perez
1991-01-01
The way in which a Hall effect transducer is made appropriate for measuring magnetic fields is described. The aim of this is to provide a thermally well compensated probe that gives precise orientation and positioning for taking measurements. This probe is used in the checking of far fields generated by magnetic dipoles.
Constraining the neutrino magnetic dipole moment from white dwarf pulsations
Alejandro H. Córsico; Leandro G. Althaus; Marcelo M. Miller Bertolami; S. O. Kepler; Enrique García-Berro
2014-07-25
Pulsating white dwarf stars can be used as astrophysical laboratories to constrain the properties of weakly interacting particles. Comparing the cooling rates of these stars with the expected values from theoretical models allows us to search for additional sources of cooling due to the emission of axions, neutralinos, or neutrinos with magnetic dipole moment. In this work, we derive an upper bound to the neutrino magnetic dipole moment using an estimate of the rate of period change of the pulsating DB white dwarf star PG 1351+489. By comparing the theoretical rate of change of period expected for this star with the rate of change of period with time of PG 1351+489, we assess the possible existence of additional cooling by neutrinos with magnetic dipole moment. Our models suggest the existence of some additional cooling in this pulsating DB white dwarf, consistent with a non-zero magnetic dipole moment. Our upper limit for the neutrino magnetic dipole moment is somewhat less restrictive than, but still compatible with, other limits inferred from the white dwarf luminosity function or from the color-magnitude diagram of the Globular cluster M5. Further improvements of the measurement of the rate of period change of the dominant pulsation mode of PG 1351+489 will be necessary to confirm our bound.
The field of the vertical electric dipole immersed in the heterogeneous half-space
NASA Astrophysics Data System (ADS)
Barsukov, P. O.; Fainberg, E. B.
2014-07-01
The field of the vertical electric dipole (VED) immersed in the heterogeneous conductive halfspace (sea) is analyzed in time domain. In the near field of the source, the amplitudes of the electric and magnetic components of the field are proportional to power 3/2 and power 5/2 of the conductivity of the medium, respectively. After termination of the transmitter pulse, all the VED components decay with time as ˜1/ t 5/2. The possibility of applying the VED field for estimating the electrical properties of the offshore geological sections is demonstrated.
electric dipole moment measurement by Stark level crossing and ef mixing spectroscopy
Auzinsh, Marcis
NaK D 1 electric dipole moment measurement by Stark level crossing and ef mixing spectroscopy M presents the first permanent electric dipole moment dp measurements for NaK D1 state rovibronic levels. Two the electric dipole moment value and the -doubling splitting between e,f substates of an individual rotational
Magnetic dipole properties in deformed nuclei
NASA Astrophysics Data System (ADS)
Faessler, A.
The magnetic dipole response in deformed nuclei is investigated. Spurious states due to the rotation of the whole nucleus are removed by restricting the residual interaction in such a way that it commutes with the total angular momentum as a ground state expectation value in the quasi-particle random phase approximation. By this one guarantees that the spurious state due to rotations lies at energy zero and that it is a solution of the quasi-particle random phase equation (QRPA) and can easily be removed. The Hamiltonian is chosen to be a deformed Saxon Woods potential with a pairing force and an isoscalar and isovector generalized quadrupole-quadrupole and spin-spin interaction. The generalized isoscalar quadrupole operator is defined as the commutator of the independent quasi-particle Hamiltonian with the total angular momentum. The restoration of rotational symmetry mentioned above determines the isoscalar coupling constant. The generalized isovector quadrupole-quadrupole force does not commute with the total angular momentum. But one can find a linear “isovector” combination of the proton and the neutron total angular momentum which produces by a commutator with the independent quasiparticle Hamiltonian an “isovector” quadrupole operator which yields an isovector quadrupole-quadrupole force which always commutes with the total angular momentum. Thus one gets no restriction of the isovector quadrupole-quadrupole force constant. We fit it to the isovector giant quadrupole resonance ( E(E2) = {130}/{A {1}/{3}}MeV). The Hamiltonian contains in addition a spin-spin force, which always commutes with the total angular momentum and therefore does not spoil the restoration of rotational symmetry. The proton-proton, neutron-neutron and proton-neutron spin force constant is determined by solving the nuclear matter problem with the Reid soft core interaction within the Brückner theory and translating the result with the help of the Migdal force into finite nuclei. This yields an almost pure repulsive isovector spin-spin force. This Hamiltonian predicts a high lying ?N = 2 scissors mode which lies between 17 and 26 MeV. It is spread over very many 1 + states with an average spacing of 15 keV. This highlying scissors mode consists of several hundred states and the overlap with an artificially constructed scissors mode is of the order of 38%, while the low lying scissors mode which shows up as 1 + states around 3 MeV has an overlap with the scissors mode of more than 50 %. In the same energy range as the high lying scissors mode lies also the isovector giant quadrupole resonance. Even at 180°, that means at completely backward angles, the E2 is comparable with the M1 excitation. This is due to the transversal quadrupole transition probability which is not disappearing in electron scattering at 180°. The same Hamiltonian is nicely describing the low lying scissors mode around 3 MeV in the rare earth and the transuranic nuclei. It gives the energies and the reduced magnetic dipole transition probabilities. It also can reproduce the formfactors measured by inelastic electron scattering. The Hamiltonian also reproduces the spin-flip states between 5 and 9 MeV excitation energy, which can be measured by inelastic proton scattering. One obtains in this region two maxima. The lowest one around 6 MeV is mainly of isoscalar nature and is weaker than the spin flip maximum at 7 to 8 MeV, which is mainly of isovector nature. The detailed form of this two-spin flip maxima depend very sensitively on the ratio of the isoscalar and isovector strength of the spin-spin force. In conclusion one can say: There exist a high lying scissors mode, but it is strongly fragmented over several hundred 1 + states between 17 and 26 MeV and even in electron scattering at backward angles the cross section for the excitation of the isovector giant quadrupole resonance is of comparable size. Thus it will be difficult to establish experimentally the existence of this high lying scissors mode.
Improved Experimental Limit on the Electric Dipole Moment of the Neutron
C. A. Baker; D. D. Doyle; P. Geltenbort; K. Green; M. G. D. van der Grinten; P. G. Harris; P. Iaydjiev; S. N. Ivanov; D. J. R. May; J. M. Pendlebury; J. D. Richardson; D. Shiers; K. F. Smith
2006-01-01
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
New measurements of neutron electric dipole moment with double chamber EDM spectrometer
A. P. Serebrov; E. A. Kolomenskiy; A. N. Pirozhkov; I. A. Krasnoshekova; A. V. Vasiliev; A. O. Polyushkin; M. S. Lasakov; A. N. Murashkin; V. A. Solovey; A. K. Fomin; I. V. Shoka; O. M. Zherebtsov; P. Geltenbort; S. N. Ivanov; O. Zimmer; E. B. Alexandrov; S. P. Dmitriev; N. A. Dovator
2014-08-27
The article presents results on neutron electric dipole moment measurements (EDM), made by ILL reactor using PNPI experimental installation. Double chamber magnetic resonance spectrometer with prolonged holding of ultra cold neutrons has been employed. The obtained results at 90% confidence level determine the upper limit for EDM neutron quantity equal to $|d_n| < 5.5 \\cdot 10^{-26}$ e$ \\cdot$cm.
Neutron electric dipole moment induced by strangeness revisited
NASA Astrophysics Data System (ADS)
Fuyuto, Kaori; Hisano, Junji; Nagata, Natsumi
2013-03-01
We have revisited the calculation of the neutron electric dipole moment in the presence of the CP-violating operators up to dimension 5 based on the chiral perturbation theory. In particular, we focus on the contribution of strangeness content. In the calculation, we extract the nucleon matrix elements of scalar-type quark operators from the results of the lattice QCD simulations, while those of the dipole-type quark-gluon operators are evaluated by using the method of the QCD sum rules. As a result, it is found that although the strangeness quantity in nucleons is small, the contribution of the chromoelectric dipole moment of strange quarks may still be sizable, and thus may offer a sensitive probe for the CP-violating interactions in physics beyond the Standard Model.
Demonstration of current drive by a rotating magnetic dipole field
NASA Astrophysics Data System (ADS)
Giersch, L.; Slough, J. T.; Winglee, R.
2007-04-01
Abstract.A dipole-like rotating magnetic field was produced by a pair of circular, orthogonal coils inside a metal vacuum chamber. When these coils were immersed in plasma, large currents were driven outside the coils: the currents in the plasma were generated and sustained by the rotating magnetic dipole (RMD) field. The peak RMD-driven current was at roughly two RMD coil radii, and this current (60 kA m-) was sufficient to reverse the ambient magnetic field (33 G). Plasma density, electron temperature, magnetic field and current probes indicated that plasma formed inside the coils, then expanded outward until the plasma reached equilibrium. This equilibrium configuration was adequately described by single-fluid magnetohydrodynamic equilibrium, wherein the cross product of the driven current and magnetic filed was approximately equal to the pressure gradient. The ratio of plasma pressure to magnetic field pressure, ?, was locally greater than unity.
Asteroseismic Constraints on the Neutrino Magnetic Dipole Moment
NASA Astrophysics Data System (ADS)
Córsico, Alejandro H.; Althaus, Leandro G.; Miller Bertolami, Marcelo M.; Kepler, S. O.; García-Berro, Enrique
2015-06-01
Pulsating white dwarf (WD) stars can be used as astrophysical laboratories to constrain the properties of weakly interacting particles. Comparing the cooling rates of these stars with the expected values from theoretical models allows us to search for additional sources of cooling due to the emission of axions, neutralinos, or neutrinos with magnetic dipole moment. In this work, we derive an upper bound to the neutrino magnetic dipole moment (??) using an estimate of the rate of period change of the pulsating DB WD star PG 1351+489. Our models suggest the existence of some additional cooling in this pulsating DB WD, consistent with a non-zero magnetic dipole moment with an upper limit of ???10–11 ?B.
Sushkov, A O; Lamoreaux, S K
2009-01-01
We propose to use ferroelectric (Eu,Ba)TiO$_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 Eu concentrations and measured their properties relevant for such a search: permeability, magnetization noise, and ferroelectric hysteresis loops. The results of our measurements indicate that a search for the electron electric dipole moment with Eu$_{0.5}$Ba$_{0.5}$TiO$_3$ should lead to an order of magnitude improvement on the current best limit.
Communication: Magnetic dipole transitions in the OH A 2?+ ? X 2? system
NASA Astrophysics Data System (ADS)
Kirste, Moritz; Wang, Xingan; Meijer, Gerard; Gubbels, Koos B.; van der Avoird, Ad; Groenenboom, Gerrit C.; van de Meerakker, Sebastiaan Y. T.
2012-09-01
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 × 103 only, i.e., much less than commonly believed. Our experimental data confirm this prediction.
Communication: Magnetic dipole transitions in the OH A 2?+ ? X 2? system.
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
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
Sharma, N.K.; Saxena, P.; Singh, S.; Nagawat, A.K.; Sahu, R.S. [Department of Physics, University of Rajasthan, Jaipur 302 004 (India)] [Department of Physics, University of Rajasthan, Jaipur 302 004 (India)
1997-10-01
W{sup {plus_minus}}H{sup {minus_plus}}Z{sub i} (i=1,2) vertices available exclusively in the extra U(1) superstring-inspired model have been utilized to evaluate the W-W-{gamma} vertex contribution at the one loop level. The expressions so obtained have been used to estimate the anomalous magnetic dipole moment ({Delta}k{sub WZ{sub i}H}) and electric quadrupole moment ({Delta}Q{sub WZ{sub i}H}) of the W{sup +} boson. The contribution of the Z{sub 2}WW vertex is also added to these values. The resulting values in the unit of ({minus}{alpha}/{pi}) when the Z{sub 2} mass varies from 555 to 620 GeV have the following ranges: for m{sub t(CDF)}=175.6GeV, {Delta}k{sub [U(1)]}, from 25.402 to 41.559, {Delta}Q{sub [U(1)]}, from 6.886 to 10.858; for m{sub t(D0)}=169GeV, {Delta}k{sub [U(1)]}, from 20.821 to 34.121, {Delta}Q{sub [U(1)]}, from 5.738 to 9.033. These are larger than the standard model radiative correction contributions but an order of magnitude smaller than those predicted by the composite model of Abbott and Farhi.
SKEW QUADRUPOLES IN RHIC DIPOLE MAGNETS AT HIGH FIELDS.
JAIN, A.; GUPTA, P.; THOMPSON, P.; WANDERER, P.
1995-06-11
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.
Skew quadrupole in RHIC dipole magnets at high fields
Jain, A.; Gupta, R.; Thompson, P.; Wanderer, P. [Brookhaven National Lab., Upton, NY (United States)] [Brookhaven National Lab., Upton, NY (United States)
1996-07-01
In the RHIC are 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 RHIC 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.
Skew quadrupole in RHIC dipole magnets at high fields
Jain, A.; Gupta, P.; Thompson, P.; Wanderer, P.
1995-07-01
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 RHIC 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.
A variable-field permanent-magnet dipole for accelerators
Kraus, R.H. Jr.; Barlow, D.B.; Meyer, R.
1992-01-01
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.
A variable-field permanent-magnet dipole for accelerators
Kraus, R.H. Jr.; Barlow, D.B.; Meyer, R.
1992-09-01
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.
Baryon electric dipole moments from strong CP violation
Feng-Kun Guo; Ulf-G. Meißner
2012-11-28
The electric dipole form factors and moments of the ground state baryons are calculated in chiral perturbation theory at next-to-leading order. We show that the baryon electric dipole form factors at this order depend only on two combinations of low-energy constants. We also derive various relations that are free of unknown low-energy constants. We use recent lattice QCD data to calculate all baryon EDMs. In particular, we find d_n = -2.9\\pm 0.9 and d_p = 1.1\\pm 1.1 in units of 10^{-16} e \\theta_0 cm. Finite volume corrections to the moments are also worked out. We show that for a precision extraction from lattice QCD data, the next-to-leading order terms have to be accounted for.
Self-generated magnetic dipoles in weakly magnetized beam-plasma system.
Jia, Qing; Mima, Kunioki; Cai, Hong-bo; Taguchi, Toshihiro; Nagatomo, Hideo; He, X T
2015-02-01
A self-generation mechanism of magnetic dipoles and the anomalous energy dissipation of fast electrons in a magnetized beam-plasma system are presented. Based on two-dimensional particle-in-cell simulations, it is found that the magnetic dipoles are self-organized and play important roles in the beam electron energy dissipation. These dipoles drift slowly in the direction of the return flow with a quasisteady velocity, which depends upon the magnetic amplitude of the dipole and the imposed external magnetic field. This dipole formation provides a mechanism for the anomalous energy dissipation of a relativistic electron beam, which would play an important role in collisionless shock and ion shock acceleration. PMID:25768618
Gravitational waves from inspiralling compact binaries with magnetic dipole moments
Kunihito Ioka; Keisuke Taniguchi
2000-01-13
We investigate the effects of the magnetic dipole-dipole coupling and the electromagnetic radiation on the frequency evolution of gravitational waves from inspiralling binary neutron stars with magnetic dipole moments. This study is motivated by the discovery of the superstrongly magnetized neutron stars, i.e., magnetar. We derive the contributions of the magnetic fields to the accumulated cycles in gravitational waves as $N_{mag} \\sim 6 \\times 10^{-3} (H/10^{16}{\\rm G})^{2}$, where $H$ denotes the strength of the polar magnetic fields of each neutron star in the binary system. It is found that the effects of the magnetic fields will be negligible for the detection and the parameter estimation of gravitational waves, if the upper limit for magnetic fields of neutron stars are less than $\\sim 10^{16}$G, which is the maximum magnetic field observed in the soft gamma repeaters and the anomalous X-ray pulsars up to date. We also discuss the implications of electromagnetic radiation from the inspiralling binary neutron stars for the precursory X-ray emission prior to the gamma ray burst observed by the Ginga satellite.
An update on passive correctors for the SSC dipole magnets
Green, M.A.
1991-05-01
The concept of correction of the magnetization sextupole became a topic of discussion as soon as it was realized that superconductor magnetization could have a serious effect on the SSC beam during injection. Several methods of correction were proposed. These included (1) correction with active bore tube windings like those on the HERA machine which correct out magnetization sextupole and the sextupole due to iron saturation, (2) correction with persistent sextupole windings mounted on the bore tube (3) correction using passive superconductor (4) correction using ferromagnetic material, and (5) correction using oriented magnetized materials. This report deals with the use of passive superconductor to correct the magnetization sextupole. Two basic methods are explored in this report: (1) One can correct the magnetization sextupole by changing the diameter of the superconductor filaments in one or more blocks of the SSC dipole. (2) One can correct the magnetization sextupole and decapole by mounting passive superconducting wires on the inside of the SSC dipole coil bore. In addition, an assessment of the contribution of each conductor in the dipole to the magnetization sextupole and decapole is shown. 38 refs, 25 figs., 15 tabs.
A cosmological lower bound on the neutron electric dipole moment
John Ellis; Mary K. Gaillard; D. V. Nanopoulos; Serge Rudaz
1981-01-01
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
Electric dipole moments as probes of new physics
Maxim. Pospelov; Adam Ritz
2005-01-01
We review several aspects of flavour-diagonal CP-violation, focussing on the role played by the electric dipole moments (EDMs) of leptons, nucleons, atoms, and molecules, which constitute the source of several stringent constraints on new CP-violating physics. We dwell specifically on the calculational aspects of applying the hadronic EDM constraints, reviewing in detail the application of QCD sum-rules to the calculation
Plasma stability in a dipole magnetic field
Simakov, Andrei N., 1974-
2001-01-01
The MHD and kinetic stability of an axially symmetric plasma, confined by a poloidal magnetic field with closed lines, is considered. In such a system the stabilizing effects of plasma compression and magnetic field ...
Reexamination of The Standard Model Nucleon Electric Dipole Moment
Chien-Yeah Seng
2015-02-06
The Cabibbo-Kobayashi-Maskawa matrix in the Standard Model is currently the only experimentally-confirmed source of CP-violation. The intrinsic electric dipole moment of the nucleon induced by this CP-phase via hadronic loop and pole diagrams has been studied more than two decades ago, but the existing calculation is subject to various theoretical issues such as the breakdown of chiral power counting and uncertainties in the determination of low energy constants. We carry out an up-to-date re-analysis on both one-loop and pole diagram contributions to the nucleon electric dipole moment based on Heavy Baryon Chiral Perturbation Theory in a way that preserves power counting, and redo the determination of the low energy constants following the results of more recent articles. Combined with an estimation of higher-order contributions, we expect the long-distance contribution to the Standard Model nucleon electric dipole moment to be approximately $(1\\times10^{-32}-6\\times10^{-32})e\\,\\mathrm{cm}$.
Rheometry Experiment of Electric Dipole Antennas Onboard GEOTAIL
NASA Astrophysics Data System (ADS)
Imachi, T.; Yagitani, S.; Nagano, I.; Higashi, R.; Tsutsui, M.; Matsumoto, H.
2001-12-01
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.
Search for electric dipole moments at storage rings
Gerco Onderwater
2012-04-11
Permanent electric dipole moments (EDMs) violate parity and time reversal symmetry. Within the Standard Model (SM) they are many orders of magnitude below present experimental sensitivity. Many extensions of the SM predict much larger EDMs, which are therefore an excellent probe for the existence of "new physics". Until recently it was believed that only electrically neutral systems could be used for sensitive searches of EDMs. With the introduction of a novel experimental method, high precision for charged systems will be within reach as well. The features of this method and its possibilities are discussed.
Kyoichi Iigusa; Takuma Sawaya; Makoto Taromaru; Takashi Ohira; Bokuji Komiyama
2006-01-01
We examine that an inductively loaded dipole becomes electrical invisible showing that the influence on a nearby antenna's input impedance and on its radiation pattern (scattering) are minimized. We also verify that the direction of the current reverses on the electrically invisible dipole so that the integral of the dipole current becomes zero. By making an inductive load with a
Disk Formation by AGB Winds in Dipole Magnetic Fields
S. Matt; B. Balick; R. Winglee; A. Goodson
2000-08-08
We present a simple, robust mechanism by which an isolated star can produce an equatorial disk. The mechanism requires that the star have a simple dipole magnetic field on the surface and an isotropic wind acceleration mechanism. The wind couples to the field, stretching it until the field lines become mostly radial and oppositely directed above and below the magnetic equator, as occurs in the solar wind. The interaction between the wind plasma and magnetic field near the star produces a steady outflow in which magnetic forces direct plasma toward the equator, constructing a disk. In the context of a slow (10 km/s) outflow (10^{-5} M_sun/yr) from an AGB star, MHD simulations demonstrate that a dense equatorial disk will be produced for dipole field strengths of only a few Gauss on the surface of the star. A disk formed by this model can be dynamically important for the shaping of Planetary Nebulae.
Electric dipole moments of nanosolvated acid molecules in water clusters
Guggemos, Nicholas; Kresin, Vitaly V
2015-01-01
The electric dipole moments of $(H_{2}O)_{n}DCl$ ($n=3-9$) clusters have been measured by the beam deflection method. Reflecting the (dynamical) charge distribution within the system, the dipole moment contributes information about the microscopic structure of nanoscale solvation. The addition of a DCl molecule to a water cluster results in a strongly enhanced susceptibility. There is evidence for a noticeable rise in the dipole moment occurring at $n\\approx5-6$. This size is consistent with predictions for the onset of ionic dissociation. Additionally, a molecular dynamics model suggests that even with a nominally bound impurity an enhanced dipole moment can arise due to the thermal and zero point motion of the proton and the water molecules. The experimental measurements and the calculations draw attention to the importance of fluctuations in defining the polarity of water-based nanoclusters, and generally to the essential role played by motional effects in determining the response of fluxional nanoscale sy...
A radiation hard dipole magnet coils using aluminum clad copper conductors
Leonhardt, W.J.
1989-01-01
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.
Entangled quantum state of magnetic dipoles
S. Ghosh; G. Aeppli; S. N. Coppersmith; T. F. Rosenbaum
2003-01-01
Free magnetic moments usually manifest themselves in Curie Laws, where weak\\u000aexternal magnetic fields produce magnetizations diverging as the reciprocal 1\\/T\\u000aof the temperature. for a variety of materials that do not disply static\\u000amagnetism, including doped semiconductors and certain rare earth\\u000aintermetallics, the 1\\/T law is changed to a power law T^-a with a<1. We report\\u000ahere that a
Four-layer, two-inch bore, superconducting dipole magnet
Hassenzahl, W.V.; Peters, C.; Gilbert, W.; Taylor, C.; Meuser, R.
1982-11-01
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.
Graded High Field Nb3Sn Dipole Magnets
S. Caspi; P. Ferracin; S. Gourlay
2007-01-01
Dipole magnets with fields beyond 16T will require superconducting coils that are at least 40 mm thick, an applied pres-stress around 150 MPa and a protection scheme for stored energy in the range of 1-2 MJ\\/m. The coil size will have a direct impact on the overall magnet cost and the stored energy will raise new questions on protection. To
Isospin properties of electric dipole excitations in 48Ca
NASA Astrophysics Data System (ADS)
Derya, V.; Savran, D.; Endres, J.; Harakeh, M. N.; Hergert, H.; Kelley, J. H.; Papakonstantinou, P.; Pietralla, N.; Ponomarev, V. Yu.; Roth, R.; Rusev, G.; Tonchev, A. P.; Tornow, W.; Wörtche, H. J.; Zilges, A.
2014-03-01
Two different experimental approaches were combined to study the electric dipole strength in the doubly-magic nucleus 48Ca below the neutron threshold. Real-photon scattering experiments using bremsstrahlung up to 9.9 MeV and nearly mono-energetic linearly polarized photons with energies between 6.6 and 9.51 MeV provided strength distribution and parities, and an (?,???) experiment at E?=136 MeV gave cross sections for an isoscalar probe. The unexpected difference observed in the dipole response is compared to calculations using the first-order random-phase approximation and points to an energy-dependent isospin character. A strong isoscalar state at 7.6 MeV was identified for the first time supporting a recent theoretical prediction.
Capacitive Stress Gauges in Model Dipole Magnets
Ragland, R. Blake
2009-06-09
Capacitive transducers are used to measure mechanical stress in the windings of superconducting magnets. The transducer consists of a bonded laminate of alternating thin foils of stainless steel and high-strength polymer (polyimide). The thin...
New experimental limit on the electric dipole moment of the electron in a paramagnetic insulator
NASA Astrophysics Data System (ADS)
Kim, Y. J.; Liu, C.-Y.; Lamoreaux, S. K.; Visser, G.; Kunkler, B.; Matlashov, A. N.; Long, J. C.; Reddy, T. G.
2015-05-01
We report results of an experimental search for the intrinsic electric dipole moment of the electron (eEDM) using a solid-state technique. The experiment employs a paramagnetic, insulating gadolinium gallium garnet (GGG) that has a large magnetic response at low temperatures. The presence of the eEDM would lead to a small but nonzero magnetization as the GGG sample is subjected to a strong electric field. We search for the resulting Stark-induced magnetization with a sensitive magnetometer. Recent progress on the suppression of several sources of background allows the experiment to run free of spurious signals at the level of the statistical uncertainties. We report our first limit on the eEDM of (-5.57 ±7.98 ±0.12 )×10-25 e cm with 5 days of data averaging.
New Experimental Limit on the Electric Dipole Moment of the Electron in a Paramagnetic Insulator
Y. J. Kim; C. -Y. Liu; S. K. Lamoreaux; G. Visser; B. Kunkler; A. N. Matlashov; J. C. Long; T. G. Reddy
2015-06-01
We report results of an experimental search for the intrinsic Electric Dipole Moment (EDM) of the electron using a solid-state technique. The experiment employs a paramagnetic, insulating gadolinium gallium garnet (GGG) that has a large magnetic response at low temperatures. The presence of the eEDM would lead to a small but non-zero magnetization as the GGG sample is subject to a strong electric field. We search for the resulting Stark-induced magnetization with a sensitive magnetometer. Recent progress on the suppression of several sources of background allows the experiment to run free of spurious signals at the level of the statistical uncertainties. We report our first limit on the eEDM of $(-5.57 \\pm 7.98 \\pm 0.12)\\times$10$^{-25}$e$\\cdot$cm with 5 days of data averaging.
Refrigeration options for the Advanced Light Source Superbend Dipole Magnets
Green, M.A.; Hoyer, E.H.; Schlueter, R.D.; Taylor, C.E.; Zbasnik, J.; Wang, S.T.
1999-07-09
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.
Entangled quantum state of magnetic dipoles.
Ghosh, S; Rosenbaum, T F; Aeppli, G; Coppersmith, S N
2003-09-01
Free magnetic moments usually manifest themselves in Curie laws, where weak external magnetic fields produce magnetizations that vary as the reciprocal of the temperature (1/T). For a variety of materials that do not display static magnetism, including doped semiconductors and certain rare-earth intermetallics, the 1/T law is replaced by a power law T(-alpha) with alpha < 1. Here we show that a much simpler material system-namely, the insulating magnetic salt LiHo(x)Y(1-x)F(4)-can also display such a power law. Moreover, by comparing the results of numerical simulations of this system with susceptibility and specific-heat data, we show that both energy-level splitting and quantum entanglement are crucial to describing its behaviour. The second of these quantum mechanical effects-entanglement, where the wavefunction of a system with several degrees of freedom cannot be written as a product of wavefunctions for each degree of freedom-becomes visible for remarkably small tunnelling terms, and is activated well before tunnelling has visible effects on the spectrum. This finding is significant because it shows that entanglement, rather than energy-level redistribution, can underlie the magnetic behaviour of a simple insulating quantum spin system. PMID:12955135
Candidate molecular ions for an electron electric dipole moment experiment
Meyer, Edmund R.; Bohn, John L.; Deskevich, Michael P. [Department of Physics, JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440 (United States); Department of Chemistry and Biochemistry, JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440 (United States)
2006-06-15
This paper is a theoretical work in support of a newly proposed experiment [R. Stutz and E. Cornell, Bull. Am. Soc. Phys. 89, 76 (2004)] that promises greater sensitivity to measurements of the electron's electric dipole moment (EDM) based on the trapping of molecular ions. Such an experiment requires the choice of a suitable molecule that is both experimentally feasible and possesses an expectation of a reasonable EDM signal. We find that the molecular ions PtH{sup +} and HfH{sup +} are both suitable candidates in their low-lying {sup 3}{delta} states. In particular, we anticipate that the effective electric fields generated inside these molecules are approximately 73 and -17 GV/cm, respectively. As a byproduct of this discussion, we also explain how to make estimates of the size of the effective electric field acting in a molecule, using commercially available nonrelativistic molecular structure software.
Full length SSC R and D dipole magnet test results
Strait, J.; Bleadon, M.; Brown, B.C.; Hanft, R.; Kuchnir, M.; Lamm, M.; Mantsch, P.; Mazur, P.O.; Orris, D.; Peoples, J.
1989-03-01
Four full scale SSC development dipole magnets have been tested for mechanical and quench behavior. Two are of a design similar to previous magnets but contain a number of improvements, including more uniform coil size, higher pre-stress and a redesigned inner-outer coil splice. One exceeds the SSC operating current on the second quench but the other appears to be limited by damaged superconductor to a lower current. The other two magnets are of alternate designs. One trains erratically and fails to reach a plateau and the other reaches plateau after four quenches. 12 refs., 4 figs.
A superconducting dipole magnet for laser spectroscopy
Wagenhauser, Kenneth Edward
1990-01-01
steel sheath holds the halves of the hon core together, and provides the exterior surface of the magnet. The sheath is one meter in length, and the windings are only slightly shorter. In order to reduce the heat input to the cryostat by the main power... above its critical temperanue. When a power supply is being used to operate the magnet, the heater wire carries a current which generates sufficient heat to keep the switch open. The superconducting element is too warm to superconduct, and the switch...
Capacitive Stress Gauges in Model Dipole Magnets
Ragland, R. Blake
2009-06-09
magnitude stresses in room temperature to cryogenic (~2K) environments where space is at a premium. In this instance, they will measure a few to a few hundred MPa present in the superconducting coil while energized to magnetic fields in the 10 Tesla...
NASA Astrophysics Data System (ADS)
Yun, Sang Jae; Kim, Jaewan; Nam, Chang Hee
2015-04-01
In quantum information processing, one of the most useful interactions between qubits is the Ising type interaction. We propose a scheme to implement the exact Ising interaction through magnetic dipole–dipole interaction. Although magnetic dipolar interaction is Heisenberg type in general, this interaction can bring about the exact mathematical form of the Ising interaction if qubit levels are chosen among the highest magnetic quantum number states. Real physical systems to which our scheme can be applied include rotational states of molecules, hyperfine states of atoms, or electronic states of nitrogen-vacancy centers in diamond. We analyze the feasibility of our scheme for these systems. For example, when the hyperfine levels of rubidium 87 atoms are chosen as qubits and the distance of the two atoms is 0.1 micrometer, the controlled-Z gate time will be 8.5 ms. We suggest diverse search and study to achieve optimal implementation of this scheme.
Sang Jae Yun; Jaewan Kim; Chang Hee Nam
2015-03-30
In quantum information processing, one of the most useful interaction between qubits is the Ising type interaction. We propose a scheme to implement the exact Ising interaction through magnetic dipole-dipole interaction. Although magnetic dipolar interaction is Heisenberg type in general, this interaction can bring about the exact mathematical form of the Ising interaction if qubit levels are chosen among the highest magnetic quantum number states. Real physical systems to which our scheme can be applied include rotational states of molecules, hyperfine states of atoms, or electronic states of nitrogen-vacancy centers in diamond. We analyze the feasibility of our scheme for these systems. For example, when the hyperfine levels of rubidium 87 atoms are chosen as qubits and the distance of the two atoms is 0.1 micrometer, controlled-Z gate time will be 8.5 ms. We suggest diverse search and study to achieve optimal implementation of this scheme.
Parity-violating electric-dipole transitions in helium
NASA Technical Reports Server (NTRS)
Hiller, J.; Sucher, J.; Bhatia, A. K.; Feinberg, G.
1980-01-01
The paper examines parity-violating electric-dipole transitions in He in order to gain insight into the reliability of approximate calculations which are carried out for transitions in many-electron atoms. The contributions of the nearest-lying states are computed with a variety of wave functions, including very simple product wave functions, Hartree-Fock functions and Hylleraas-type wave functions with up to 84 parameters. It is found that values of the matrix elements of the parity-violating interaction can differ considerably from the values obtained from the good wave functions, even when these simple wave functions give accurate values for the matrix elements in question
Generalized Wannier functions: a comparison of molecular electric dipole polarizabilities
O'Regan, David D; Mostofi, Arash A
2012-01-01
Localized Wannier functions provide an efficient and intuitive means by which to compute dielectric properties from first principles. They are most commonly constructed in a post-processing step, following total-energy minimization. Nonorthogonal generalized Wannier functions (NGWFs) may be also optimized in situ, in the process of solving for the ground-state density. We explore the relationship between NGWFs and orthonormal, maximally localized Wannier functions (MLWFs), demonstrating that NGWFs may be used to compute electric dipole polarizabilities efficiently, with no necessity for post-processing optimization, and with an accuracy comparable to MLWFs.
Reappraisal of the Electric Dipole Moment Enhancement Factor for Thallium
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
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.
NASA Astrophysics Data System (ADS)
RadžiÅ«tÄ--, Laima; Gaigalas, Gediminas; Jönsson, Per; Biero?, Jacek
2014-07-01
The multiconfiguration Dirac-Hartree-Fock method is employed to calculate atomic electric dipole moments in the ground states of Ra225, Hg199, and Yb171. For the calculations of the matrix elements we extend the relativistic atomic structure package grasp2k. The extension includes programs to evaluate matrix elements of PT-odd electron-nucleus tensor-pseudotensor and pseudoscalar-scalar interactions, the atomic electric dipole operator, the nuclear Schiff moment, and the interaction of the electron electric dipole moment with nuclear magnetic moments. The interelectronic interactions are accounted for through valence and core-valence electron correlation effects. The electron shell relaxation is included with separately optimized wave functions of opposite parities.
Performance of dipole magnets in helium II
Althaus, R.; Caspi, S.; Gilbert, W.S.; Hassenzahl, W.; Meuser, R.; Rechen, J.; Taylor, C.; Warren, R.
1981-03-01
Data from tests in He II of four 1-meter-long magnets are presented. The maximum quench current is increased up to 30 percent, compared with tests in He I. Data from calorimetric measurements of heat generated during cyclic operation are presented. Quenches were induced by heaters placed near the conductor, and the energy required to induce quenches in He II and in He I are compared.
Polarized electric dipole moment of well-deformed reflection asymmetric nuclei
V. Yu. Denisov
2011-06-06
The expression for polarized electric dipole moment of well-deformed reflection asymmetric nuclei is obtained in the framework of liquid-drop model in the case of geometrically similar proton and neutron surfaces. The expression for polarized electric dipole moment consists of the first and second orders terms. It is shown that the second-order correction terms of the polarized electric dipole moment are important for well-deformed nuclei.
Dipole corrector magnets for the LBNE beam line
Yu, M.; Velev, G.; Harding, D.; /Fermilab
2011-03-01
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.
Magnetic and Thermal Characteristics of a Model Dipole Magnet for the SIS 300
S. Kozub; L. Tkachenko; V. Zubko; E. Floch; J. Kaugerts; G. Moritz; B. Auchmann; S. Russenschuck; D. Tommasini
2007-01-01
The synchrotron SIS 300, developed for the Facility for Antiproton and Ion Research (FAIR) project at GSI, will use fast-cycling dipoles with 100 mm inner diameter coils, magnetic field amplitude of 6 T and a ramp rate of 1 T\\/s. This work presents the calculations of the magnetic and thermal characteristics of a 1 m model dipole with optimized 2D
Determination of the Magnetic Dipole Moment of the Rho Meson
NASA Astrophysics Data System (ADS)
Toledo Sánchez, G.; García Gudiño, D.
2014-12-01
We determine the magnetic dipole moment of the rho meson using preliminary data from the BaBar Collaboration for the e+e- ? ?+?-2?0 process, in the center of mass energy range from 0.9 to 2.2 GeV. We describe the ?* ? 4? vertex using a vector meson dominance model, including all intermediate resonance contributions. We find that ?? = 2.1 ± 0.5 [e/2m?].
Magnetization Measurements of Wires for the Next European Dipole (NED)
Michela Greco; Cristina Bernini; Pasquale Fabbricatore; Carlo Ferdeghini; Umberto Gambardella
2006-01-01
The Next European Dipole (NED) activity is developing a high-performance Nb3Sn wire (aiming at a noncopper critical current density of 1500 A\\/mm2 at 4.2 K and 15 T), within the framework of the Coordinated Accelerator Research in Europe (CARE) project. As part of the conductor development program, magnetization measurements are carried out in parallel and transverse field, from low fields
Visualizing Special Relativity: The Field of An Electric Dipole Moving at Relativistic Speed
ERIC Educational Resources Information Center
Smith, Glenn S.
2011-01-01
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…
Proposal to measure the muon electric dipole moment with a compact storage
Roberts, B. Lee
Proposal to measure the muon electric dipole moment with a compact storage ring at PSI Thomas Introduction: lepton dipole moments Muon spin precession in B and E fields (g2)µ and µEDM at storage rings PSI, 4 July 2007Measuring the muon EDM at PSI 3 Lepton dipole moments Define g and as unit
Electric and magnetic response to the continuum for A=7 isobars in a dicluster model
A. Mason; R. Chatterjee; L. Fortunato; A. Vitturi
2008-11-11
Mirror isobars $^7$Li and $^7$Be are investigated in a dicluster model. The magnetic dipole moments and the magnetic dipole response to the continuum are calculated in this framework. The magnetic contribution is found to be small with respect to electric dipole and quadrupole excitations even at astrophysical energies, at a variance with the case of deuteron. Energy weighted molecular sum rules are evaluated and a formula for the molecular magnetic dipole sum rule is found which matches the numerical calculations. Cross-sections for photo-dissociation and radiative capture as well as the S-factor for reactions of astrophysical significance are calculated with good agreement with known experimental data.
An Improved Search for the Neutron Electric Dipole Moment
M. Burghoff; A. Schnabel; G. Ban; T. Lefort; Y. Lemiere; O. Naviliat-Cuncic; E. Pierre; G. Quemener; J. Zejma; M. Kasprzak; P. Knowles; A. Weis; G. Pignol; D. Rebreyend; S. Afach; G. Bison; J. Becker; N. Severijns; S. Roccia; C. Plonka-Spehr; J. Zennerz; W. Heil; H. C. Koch; A. Kraft; T. Lauer; Yu. Sobolev; Z. Chowdhuri; J. Krempel; B. Lauss; A. Mtchedlishvili; P. Schmidt-Wellenburg; G. Zsigmond; M. Fertl; B. Franke; M. Horras; K. Kirch; F. Piegsa
2011-10-07
A permanent electric dipole moment of fundamental spin-1/2 particles violates both parity (P) and time re- versal (T) symmetry, and hence, also charge-parity (CP) symmetry since there is no sign of CPT-violation. The search for a neutron electric dipole moment (nEDM) probes CP violation within and beyond the Stan- dard Model. The experiment, set up at the Paul Scherrer Institute (PSI), an improved, upgraded version of the apparatus which provided the current best experimental limit, dn < 2.9E-26 ecm (90% C.L.), by the RAL/Sussex/ILL collaboration: Baker et al., Phys. Rev. Lett. 97, 131801 (2006). In the next two years we aim to improve the sensitivity of the apparatus to sigma(dn) = 2.6E-27 ecm corresponding to an upper limit of dn < 5E-27 ecm (95% C.L.), in case for a null result. In parallel the collaboration works on the design of a new apparatus to further increase the sensitivity to sigma(dn) = 2.6E-28 ecm.
An Improved Search for the Neutron Electric Dipole Moment
Burghoff, M; Ban, G; Lefort, T; Lemiere, Y; Naviliat-Cuncic, O; Pierre, E; Quemener, G; Zejma, J; Kasprzak, M; Knowles, P; Weis, A; Pignol, G; Rebreyend, D; Afach, S; Bison, G; Becker, J; Severijns, N; Roccia, S; Plonka-Spehr, C; Zennerz, J; Heil, W; Koch, H C; Kraft, A; Lauer, T; Sobolev, Yu; Chowdhuri, Z; Krempel, J; Lauss, B; Mtchedlishvili, A; Schmidt-Wellenburg, P; Zsigmond, G; Fertl, M; Franke, B; Horras, M; Kirch, K; Piegsa, F
2011-01-01
A permanent electric dipole moment of fundamental spin-1/2 particles violates both parity (P) and time re- versal (T) symmetry, and hence, also charge-parity (CP) symmetry since there is no sign of CPT-violation. The search for a neutron electric dipole moment (nEDM) probes CP violation within and beyond the Stan- dard Model. The experiment, set up at the Paul Scherrer Institute (PSI), an improved, upgraded version of the apparatus which provided the current best experimental limit, dn < 2.9E-26 ecm (90% C.L.), by the RAL/Sussex/ILL collaboration: Baker et al., Phys. Rev. Lett. 97, 131801 (2006). In the next two years we aim to improve the sensitivity of the apparatus to sigma(dn) = 2.6E-27 ecm corresponding to an upper limit of dn < 5E-27 ecm (95% C.L.), in case for a null result. In parallel the collaboration works on the design of a new apparatus to further increase the sensitivity to sigma(dn) = 2.6E-28 ecm.
LABORATORY VI ELECTRICITY FROM MAGNETISM
Minnesota, University of
LABORATORY VI ELECTRICITY FROM MAGNETISM Lab VI - 1 In the previous problems you explored the magnetic field and its effect on moving charges. You also saw how electric currents could create magnetic fields. This lab will carry that investigation one step further, determining how changing magnetic fields
LABORATORY VI ELECTRICITY FROM MAGNETISM
Minnesota, University of
LABORATORY VI ELECTRICITY FROM MAGNETISM Lab VI - 1 In the previous problems you explored the magnetic field and its effect on moving charges. You also saw how magnetic fields could be created magnetic fields can give rise to electric currents. This is the effect that allows the generation
Electric dipole polarizabilities of hydrogen and helium isotopes
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
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.
Strong dependence of ultracold chemical rates on electric dipole moments
Quemener, Goulven; Bohn, John L. [JILA, University of Colorado, Boulder, Colorado 80309-0440 (United States)
2010-02-15
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.
Design features of the SSC (Superconducting Super Collider) dipole magnet
Willen, E.; Cottingham, J.; Ganetis, G.; Garber, M.; Ghosh, A.; Goodzeit, C.; Greene, A.; Herrera, J.; Kahn, S.; Kelly, E.
1989-01-01
The main ring dipole for the SSC is specified as a high performance magnet that is required to provide a uniform, 6.6 T field in a 4 cm aperture at minimum cost. These design requirements have been addressed in an R D program in which the coil design, coil mechanical support, yoke and shell structure, trim coil and beam tube design, and a variety of new instrumentation, have been developed. The design of the magnet resulting from this intensive R D program, including various measurements from both 1.8 m and 17 m long models, is reviewed. 7 refs., 3 figs.
Electromagnetic drag on a magnetic dipole near a translating conducting bar
NASA Astrophysics Data System (ADS)
Kirpo, Maksims; Tympel, Saskia; Boeck, Thomas; Krasnov, Dmitry; Thess, André
2011-06-01
The electromagnetic drag force and torque acting on a magnetic dipole due to the translatory motion of an electrically conducting bar with square cross section and infinite length is computed by numerical analysis for different orientations and locations of the dipole. The study is motivated by the novel techniques termed Lorentz force velocimetry and Lorentz force eddy current testing for noncontact measurements of the velocity of a conducting liquid and for detection of defects in the interior of solid bodies, respectively. The present, simplified configuration provides and explains important scaling laws and reference results that can be used for verification of future complete numerical simulations of more realistic problems and complex geometries. The results of computations are also compared with existing analytical solutions for an infinite plate and with a newly developed asymptotic theory for large distances between the bar and the magnetic dipole. We finally discuss the optimization problem of finding the orientation of the dipole relative to the bar that produces the maximum force in the direction of motion.
Enhancement of magnetic dipole emission at yellow light in optical metamaterials
NASA Astrophysics Data System (ADS)
Hu, Wenliang; Yi, Ningbo; Sun, Shang; Cui, Lin; Song, Qinghai; Xiao, Shumin
2015-09-01
Here we demonstrate the control of magnetic dipole spontaneous emission at yellow light by magnetic metamaterials. By embedding magnetic dipole into a magnetic metamaterial consisting of arrays of paired silver strips, the radiative emission enhancement and the Purcell factor around 590 nm has been dramatically increased to 110 and 180 respectively. Moreover, the enhancements are found to be robust to variation of dipole's positions and structure geometries, showing nice fabrication tolerance for practical applications.
Nb3Sn accelerator magnet technology scale up using cos-theta dipole coils
F. Nobrega; N. Andreev; G. Ambrosio; E. Barzi; R. Bossert; R. Carcagno; G. Chlachidze; S. Feher; V. S. Kashikhin; V. V. Kashikhin; M. J. Lamm
2007-01-01
Fermilab is working on the development of NbSn 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
Proposal for a sensitive search for electric dipole moment of electron with matrix-isolated radicals
M. G. Kozlov; Andrei Derevianko
2006-07-31
We propose using matrix-isolated paramagnetic diatomic molecules to search for the electric dipole moment of electron (eEDM). As was suggested by Shapiro in 1968, the eEDM leads to a magnetization of a sample in the external electric field. In a typical condensed matter experiment, the effective field on the unpaired electron is of the same order of magnitude as the laboratory field, typically about $10^{5}$V/cm. We exploit the fact that the effective electric field inside heavy polar molecules is in the order of $10^{10}$V/cm. This leads to a huge enhancement of the Shapiro effect. Statistical sensitivity of the proposed experiment may allow one to improve the current limit on eEDM by three orders of magnitude in few hours accumulation time.
SUPERCONDUCTING DIPOLE MAGNETS FOR THE LHC INSERTION REGIONS
WILLEN,E.; ANERELLA,M.; COZZOLINO,J.; GANETIS,G.; GHOSH,A.; GUPTA,R.; HARRISON,M.; JAIN,A.; MARONE,A.; MURATORE,J.; PLATE,S.; SCHMALZLE,J.; WANDERER,P.; WU,K.C.
2000-06-26
Dipole bending magnets are required to change the horizontal separation of the two beams in the LHC. In Intersection Regions (IR) 1, 2, 5, and 8, the beams are brought into collision for the experiments located there. In IR4, the separation of the beams is increased to accommodate the machine's particle acceleration hardware. As part of the US contribution to the LHC Project, BNL is building the required superconducting magnets. Designs have been developed featuring a single aperture cold mass in a single cryostat, two single aperture cold masses in a single cryostat, and a dual aperture cold mass in a single cryostat. All configurations feature the 80 mm diameter, 10 m long superconducting coil design used in the main bending magnets of the Relativistic Heavy Ion Collider recently completed at Brookhaven. The magnets for the LHC, to be built at Brookhaven, are described and results from the program to build two dual aperture prototypes are presented.
NASA Astrophysics Data System (ADS)
Olson, Abraham; Chen, Yong P.
2010-03-01
Employing previously developed variational calculation techniques [1, 2], we explore various possibilities for observing effects of magnetic dipole-dipole interaction (MDDI) in Bose-Einstein condensates (BECs). The effects of MDDI on both in-trap and time-of-flight expansion dynamics are investigated, as well as effects on condensate stability. The variational calculation has been verified to agree well with experimental data in Cr^52[3] and Li^7[4]. Using current knowledge of Feshbach resonances, we determine the experimental accessibility of observing MDDI effects for the bosonic alkalis and find most favorable results for Li^7, K^39, and Cs^133. We also present calculations for Dy and Er, motivated by advances in cooling such high magnetic moment species. These results would be useful to experimentalists working on dipolar quantum gases. [4pt] [1] S. Yi and L. You, Phys. Rev. A, 63, 053607 (2001)[0pt] [2] T. Koch et al. Nature Physcis 4, 218-222 (2008)[0pt] [3] T. Lahaye et al. Nature 448, 672-675 (2007)[0pt] [4] S.E. Pollack et al. Phys. Rev. Lett. 102, 090402 (2009).
Electric and Magnetic Field Detection in Elasmobranch Fishes
NASA Astrophysics Data System (ADS)
Kalmijn, Ad. J.
1982-11-01
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.
Space propulsion by fusion in a magnetic dipole
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
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.
Schiff screening of relativistic nucleon electric-dipole moments by electrons
Liu, C.-P.; Engel, J. [T-16, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599-3255 (United States)
2007-08-15
We show, at leading-order in the multipole expansion of the electron-nucleus interaction, that nucleon electric-dipole moments are completely shielded by electrons so that they contribute nothing to atomic electric-dipole moments, even when relativity in the nucleus is taken into account. It is well known that relativistic electron motion, by contrast, leads to dipole moments that are not screened; we discuss the reasons for the difference.
S. Xia; M. Chua; P. A. Tanner
2001-01-01
The physical mechanism of the electric dipole–electric dipole (ED–ED) interaction may be looked at from several viewpoints in the calculation of the ED–ED energy transfer rate of rare earth ions in insulators. In this article, we demonstrate the equivalence of the results calculated from taking the ED–ED interaction as an energy transfer operation, or as a correction operator to the
Electrically Tunable Magnetism in Magnetic Topological Insulators
NASA Astrophysics Data System (ADS)
Zhang, Shou-Cheng; Wang, Jing; Lian, Biao
2015-03-01
The external controllability of the magnetic properties in topological insulators would be important both for fundamental and practical interests. Here we predict the electric-field control of ferromagnetism in a thin film of insulating magnetic topological insulators. The decrease of band inversion by the application of electric fields results in a reduction of magnetic susceptibility, and hence in the modication of magnetism. Remarkably, the electric field could even induce the magnetic quantum phase transition from ferromagnetism to paramagnetism. We further propose a topological transistor device in which the dissipationless charge transport of chiral edge states is controlled by an electric field. The simultaneous electrical control of magnetic order and chiral edge transport in such a device may lead to electronic and spintronic applications for topological insulators. This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, under Contract No. DE-AC02-76SF00515.
Magnetic design and analysis of the SSC high energy booster dipole magnets
NASA Astrophysics Data System (ADS)
Krefta, Mark P.; Chuboy, Helen L.; Johnson, Dave C.; Garg, Vijay
1994-07-01
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.
Magnetic design and analysis of the SSC High Energy Booster dipole magnets
Krefta, M.P.; Chuboy, H.L.; Johnson, D.C.; Garg, V. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)] [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)
1994-07-01
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.
X-ray Line from the Dark Transition Electric Dipole
Chao-Qiang Geng; Da Huang; Lu-Hsing Tsai
2014-07-27
We study a two-component dark matter (DM) model in which the two Majorana fermionic DM components with nearly degenerate masses are stabilized by an $Z_2$ symmetry and interact with the right-handed muon and tau only via real Yukawa couplings, together with an additional $Z_2$-odd singly-charged scalar. In this setup, the decay from the heavy DM to the lighter one via the transition electric dipole yields the 3.55 keV X-ray signal observed recently. The Yukawa couplings in the dark sector are assumed to be hierarchical, so that the observed DM relic abundance can be achieved with the leading s-wave amplitudes without a fine-tuning. We also consider the constraints from flavor physics, DM direct detections and collider searches, respectively.
Quench performance of Fermilab\\/General Dynamics built full length SSC collider dipole magnets
J. Strait; D. Orris; P. O. Mazur; M. Bleadon; R. Bossert; J. Carson; S. W. Delchamps; S. Gourlay; R. Hanft; W. Koska; M. Kuchnir; M. J. Lamm; J. Ozelis; M. Wake; A. Devred; J. DiMarco; J. Kuzminski; W. Nah; T. Ogitsu; M. Puglisi; J. C. Tompkins; Y. Yu; Y. Zhao; H. Zheng
1992-01-01
In this paper we present results of quench testing of full length SSC dipole magnets at Fermilab. The data are from the first six of a series of thirteen 15 m long, 50 mm aperture SSC dipole magnets which are being built and tested at Fermilab. These magnets were designed jointly by Fermilab, Brookhaven Laboratory, Lawrence Berkeley Laboratory and the
Fabrication and test results of a high field, Nb3Sn superconducting racetrack dipole magnet
R. Benjegerdes; P. Bish; D. Byford; S. Caspi; D. R. Dietderich; S. A. Gourlay; R. Hafalia; R. Hannaford; H. Higley; A. Jackson; A. Lietzke; N. Liggins; A. D. McInturff; J. O'Neill; E. Palmerston; G. Sabbi; R. M. Scanlan; J. Swanson
2001-01-01
The LBNL Superconducting Magnet Program is extending accelerator magnet technology to the highest possible fields. A 1 meter long, racetrack dipole magnet, utilizing state-of-the-art Nb3Sn superconductor, has been built and tested. A record dipole filed of 14.7 Tesla has been achieved. Relevant features of the final assembly and test results are discussed
Fabrication and test results of a high field, Nb3Sn superconducting racetrack dipole magnet
Benjegerdes, R.; Bish, P.; Byford, D.; Caspi, S.; Dietderich, D.R.; Gourlay, S.A.; Hafalia, R.; Hannaford, R.; Higley, H.; Jackson, A.; Lietzke, A.; Liggins, N.; McInturff, A.D.; O'Neill, J.; Palmerston, E.; Sabbi, G.; Scanlan, R.M.; Swanson, J.
2001-06-15
The LBNL Superconducting Magnet Program is extending accelerator magnet technology to the highest possible fields. A 1 meter long, racetrack dipole magnet, utilizing state-of-the-art Nb{sub 3}Sn superconductor, has been built and tested. A record dipole filed of 14.7 Tesla has been achieved. Relevant features of the final assembly and tested results are discussed.
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
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
Search for a Neutron Electric Dipole Moment at the SNS Brad Filippone (Caltech) for the nEDM@SNS collaboration The discovery of a neutron EDM (Electric Dipole Moment) above the Standard Model background, which
Denne, B.; Hinnov, E.
1984-04-01
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.
Search for Electric dipole moment (EDM) in laser cooled and trapped 225Ra atoms
NASA Astrophysics Data System (ADS)
Kalita, Mukut; Bailey, Kevin; Dietrich, Matthew; Green, John; Holt, Roy; Korsch, Wolfgang; Lu, Zheng-Tian; Lemke, Nathan; Mueller, Peter; O'Connor, Tom; Parker, Richard; Singh, Jaideep; Trimble, Will; Argonne National Laboratory Collaboration; University Of Chicago Collabration; University Of Kentucky Collaboration
2014-05-01
We are searching for an EDM of the diamagnetic 225Ra atom. 225Ra has nuclear spin I =1/2. Experimental sensitivity to its EDM is enhanced due to its heavy mass and the increased Schiff moment of its octupole deformed nucleus. Our experiment involves collecting laser cooled Ra atoms in a magneto-optical trap (MOT), transporting them 1 meter with a far off-resonant optical dipole trap (ODT) and then transferring the atoms to a second standing-wave ODT in our experimental chamber. We will report our recent experiences in polarizing and observing Larmor precession of 225Ra atoms in parallel electric and magnetic fields in a magnetically shielded region and progress towards a first measurement of the EDM of 225Ra. This work is supported by DOE, Office of Nuclear Physics, under contract No. DE-AC02-06CH11357 and contract No. DE-FG02-99ER41101.
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
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.
Calculation of the neutron electric dipole moment with two dynamical flavors of domain wall fermions
F. Berruto; T. Blum; K. Orginos; A. Soni
2005-12-08
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.
Calculation of the neutron electric dipole moment with two dynamical flavors of domain wall fermions
F. Berruto; T. Blum; K. Orginos; A. Soni
2005-12-08
We present a study of the neutron electric dipole moment ($\\vec d_N$) within the framework of lattice QCD with two flavors of dynamical lig ht quarks. The dipole moment is sensitive to the topological structure of the gaug e fields, and accuracy can only be achieved by using dynamical, or sea quark, calc ulations. However, the topological charge evolves slowly in these calculations, le ading to a relatively large uncertainty in $\\vec d_N$. It is shown, using quenched configurations, that a better sampling of the charge d istribution reduces this problem, but because the CP even part of the fermion determinant is absent, both the topological charge dis tribution and $\\vec d_N$ are pathological in the chiral limit. We discuss the statistical and systematic uncertainties arising from the topological charge distr ibution and unphysical size of the quark mass in our calculations and prospects fo r eliminating them. Our calculations employ the RBC collaboration two flavor domain wall fermion and DBW2 gauge action lattices with inverse lattice spacing $a^{-1}\\approx$ 1.7 GeV, physical volume $V\\approx (2$ fm)$^3$, and light quark mass roughly equal to the strange quark mass ($m_{sea}=0.03 $ and 0.04). We determine a value of the electric dipole moment that is zero withi n (statistical) errors, $|\\vec d_N| = -0.04(20)$ 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.
P. J. Cregg; Kieran Murphy; Adil Mardinoglu; Adriele Prina-Mello
2010-01-01
The implant assisted magnetic targeted drug delivery system of Avilés, Ebner and Ritter is considered both experimentally (in vitro) and theoretically. The results of a 2D mathematical model are compared with 3D experimental results for a magnetizable wire stent. In this experiment a ferromagnetic, coiled wire stent is implanted to aid collection of particles which consist of single domain magnetic
EPICS Slow Controls System in the Search for a Neutron Electric Dipole Moment
NASA Astrophysics Data System (ADS)
Taylor, Courtney
2006-10-01
The measurement of a nonzero electric dipole moment (EDM) of the neutron would significantly impact our understanding of the nature of the electro-weak and strong interactions. The goal of the current experiment is to improve the measurement sensitivity of the EDM by two orders of magnitude. The experiment is based on the magnetic-resonance technique of rotating a magnetic dipole moment in a magnetic field. The measurement of the neutron EDM comes from a measurement of the difference in the precession frequencies of neutrons when a strong electric field parallel to the magnetic field is reversed. This construction project is divided into a number of subsystems, five of which require automated control. The Experimental Physics and Industrial Control System (EPICS) is a slow-controls data acquisition (DAQ) system and is the system of choice for this experiment. It was selected for both its ease of use and ability to act as a total control system for large systems. As part of the initial research and development for the EDM project, we are setting up a prototype system that will eventually be copied and sent to the subsystem managers. This prototype consists of a VME crate housing a single board computer and DAQ modules. EPICS, running on a PC with CentOS Linux-x86, interfaces with the VME single board computer and provides a graphical user interface for the control system. The details on building this prototype DAQ system will be presented. Supported in part by the U.S. DoE.
Paris-Sud XI, Université de
241. A NEW METHOD TO INVESTIGATE THE NEUTRON ELECTRIC DIPOLE MOMENT M. FORTE, Euratom CCR the existence of a neutron electric dipole moment (EDM) is considered, based on the neutron EDM interaction with the electric dipole moments of a ferroelectric target. The changes caused in the polarization of a transmitted
6. 4 Tesla dipole magnet for the SSC
Taylor, C.E.; Caspi, S.; Gilbert, W.; Meuser, R.; Mirk, K.; Peters, C.; Scanlan, R.; Dahl, P.; Cottingham, J.; Hassenzahl, W.
1985-05-01
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.
Magnetic properties of iron yoke laminations for SSC dipole magnets
Kahn, S.A.; Morgan, G.H.
1991-01-01
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.
Pressure profiles of plasmas confined in the field of a magnetic dipole
NASA Astrophysics Data System (ADS)
Davis, Matthew S.; Mauel, M. E.; Garnier, Darren T.; Kesner, Jay
2014-09-01
Equilibrium pressure profiles of plasmas confined in the field of a dipole magnet are reconstructed using magnetic and x-ray measurements on the levitated dipole experiment (LDX). LDX operates in two distinct modes: with the dipole mechanically supported and with the dipole magnetically levitated. When the dipole is mechanically supported, thermal particles are lost along the field to the supports, and the plasma pressure is highly peaked and consists of energetic, mirror-trapped electrons that are created by electron cyclotron resonance heating. By contrast, when the dipole is magnetically levitated losses to the supports are eliminated and particles are lost via slower cross-field transport that results in broader, but still peaked, plasma pressure profiles.
Mechanical Design of HD2, a 15 T Dipole Magnet with a 35 mm Bore
P. Ferracin; S. E. Bartlett; S. Caspi; D. R. Dietderich; S. A. Gourlay; A. R. Hafalia; C. R. Hannaford; A. F. Lietzke; S. Mattafirri; A. D. McInturff; G. L. Sabbi
2006-01-01
After the fabrication and test of HD1, a 16 T Nb3Sn dipole magnet based on flat racetrack coil configuration, the Superconducting Magnet Program at Lawrence Berkeley National Laboratory (LBNL) is developing the Nb3Sn dipole HD2. With a dipole field above 15 T, a 35 mm clear bore, and nominal field harmonics within a fraction of one unit, HD2 represents a
The molecular frame electric dipole moment and hyperfine interactions in hafnium fluoride, HfF.
Le, Anh; Steimle, Timothy C; Skripnikov, Leonid; Titov, Anatoly V
2013-03-28
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
Engel, Jonathan
2007-01-01
- dipole moments are completely shielded by electrons so that they contribute nothing to atomic electric-dipole electron motion, by contrast, leads to dipole moments that are not screened; we discuss the reasons induced by the parity- and time-reversal-violating interaction of the nucleon dipole moments
A new current dipole model satisfying current continuity for inverse magnetic field source problems
Hisashi Endo; Toshiyuki Takagi; Yoshifuru Saito
2005-01-01
A new current dipole model is proposed to estimate magnetic field sources. A set of the current dipoles represents a closed-loop current element, always satisfying current continuity. The target region is filled with the closed-loop current elements to derive a system of equations, then its solution estimates unknown current distribution from given magnetic field data. The generalized vector sampled pattern
Mauel, Michael E.
Observation of Centrifugally Driven Interchange Instabilities in a Plasma Confined by a Magnetic) Centrifugally driven interchange instabilities are observed in a laboratory plasma confined by a dipole magnetic electrostatic dipole vortex [3] that transports mass, energy, and charge [4]. The centrifugally driven
Correct use of the Gordon decomposition in the calculation of nucleon magnetic dipole moments
Mekhfi, Mustapha [International Center for Theoretical Physics, Trieste, Italy and Departement de Physique, Universite Es-senia, 31100 Oran (Algeria)
2008-11-15
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.
Magnetic Testing of a Superferric Dipole That Uses Metal-Oxide Insulated CICC
DeLauter, Jonathan
A small dipole magnet designed for use in high-radiation environments that uses metal-oxide cable-in-conduit-conductor has been constructed and tested for magnetic properties. The conductor consisted of 42 strands of 0.5 ...
Purcell factor of Mie resonators featuring electric and magnetic modes
Zambrana-Puyalto, Xavier
2015-01-01
We present a modal approach to compute the Purcell factor in Mie resonators exhibiting both electric and magnetic resonances. The analytic expressions of the normal modes are used to calculate the effective volumes. We show that important features of the effective volume can be predicted thanks to the translation-addition coefficients of a displaced dipole. Using our formalism, it is easy to see that, in general, the Purcell factor of Mie resonators is not dominated by a single mode, but rather by a large superposition. Finally we consider a silicon resonator homogeneously doped with electric dipolar emitters, and we show that the average electric Purcell factor dominates over the magnetic one.
Search For A Permanent Electric Dipole Moment Using Atomic Indium
Sahoo, B K; Das, B P; 10.1103/PhysRevA.84.030502
2011-01-01
We propose indium (In) as a possible candidate for observing the permanent electric dipole moment (EDM) arising from the violations of parity (P) and time-reversal (T) symmetries. This atom has been laser cooled and therefore the measurement of its EDM has the potential of improving on the current best EDM limit for a paramagnetic atom which comes from thallium. We report the results of our calculations of the EDM enhancement factor due to the electron EDM and the ratio of the atomic EDM to the electron-nucleus scalar-pseudoscalar (S-PS) interaction coupling constant in In in the framework of the relativistic coupled cluster theory. It might be possible to get new limits for the electron EDM and the S-PS CP violating coupling constant by combining the results of our calculations with the measured value of the EDM of In when it is available. These limits could have important implications for the standard model (SM) of particle physics.
Model dependence of the {sup 2}H electric dipole moment
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
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.
Neutron Electric Dipole Moment and Tensor Charges from Lattice QCD
Tanmoy Bhattacharya; Vincenzo Cirigliano; Rajan Gupta; Huey-Wen Lin; Boram Yoon
2015-06-20
We present Lattice QCD results on the neutron tensor charges including, for the first time, a simultaneous extrapolation in the lattice spacing, volume, and light quark masses to the physical point in the continuum limit. We find that the "disconnected" contribution is smaller than the statistical error in the "connected" contribution. Our estimates in the $\\overline{\\text{MS}}$ scheme at $2$ GeV, including all systematics, are $g_T^{d-u}=1.020(76)$, $g_T^d = 0.774(66)$, $g_T^u = - 0.233(28)$, and $g_T^s = 0.008(9)$. The flavor diagonal charges determine the size of the neutron electric dipole moment (EDM) induced by quark EDMs that are generated in many new scenarios of CP-violation beyond the Standard Model (BSM). We use our results to derive model-independent bounds on the EDMs of light quarks and update the EDM phenomenology in split Supersymmetry with gaugino mass unification, finding a stringent upper bound of $d_n neutron EDM in this scenario.
Neutron Electric Dipole Moment and Tensor Charges from Lattice QCD
Tanmoy Bhattacharya; Vincenzo Cirigliano; Rajan Gupta; Huey-Wen Lin; Boram Yoon
2015-06-12
We present Lattice QCD results on the neutron tensor charges including, for the first time, a simultaneous extrapolation in the lattice spacing, volume, and light quark masses to the physical point in the continuum limit. We find that the "disconnected" contribution is smaller than the statistical error in the "connected" contribution. Our estimates in the $\\overline{\\text{MS}}$ scheme at $2$ GeV, including all systematics, are $g_T^{d-u}=1.014(75)$, $g_T^d = 0.773(65)$, $g_T^u = - 0.229(27)$, and $g_T^s = 0.008(9)$. The flavor diagonal charges determine the size of the neutron electric dipole moment (EDM) induced by quark EDMs that are generated in many new scenarios of CP-violation beyond the Standard Model (BSM). We use our results to derive model-independent bounds on the EDMs of light quarks and update the EDM phenomenology in split Supersymmetry with gaugino mass unification, finding a stringent upper bound of $d_n neutron EDM in this scenario.
Electric dipole moment of the rho-meson
Mario Pitschmann; Chien-Yeah Seng; Michael J. Ramsey-Musolf; Craig D. Roberts; Sebastian M. Schmidt; David J. Wilson
2012-09-19
At an 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 .geq. 4. Using a global-symmetry-preserving truncation of QCD's Dyson-Schwinger equations, we compute the rho-meson's electric dipole moment (EDM), d_rho, as generated by the leading dimension-four and -five CP-violating operators and an example of a dimension-six four-quark operator. The two dimension-five operators; viz., quark-EDM and -chromo-EDM, produce contributions to d_rho whose coefficients are of the same sign and within a factor of two in magnitude. Moreover, should a suppression mechanism be verified for the theta-term in any beyond-Standard-Model theory, the contribution from a four-quark operator can match the quark-EDM and -chromo-EDM in importance. This study serves as a prototype for the more challenging task of computing the neutron's EDM.
Nuclear Electric Dipole Moments in Chiral Effective Field Theory
J. Bsaisou; J. de Vries; C. Hanhart; S. Liebig; Ulf-G. Meißner; D. Minossi; A. Nogga; A. Wirzba
2015-04-30
We provide a consistent and complete calculation of the electric dipole moments of the deuteron, helion, and triton in the framework of chiral effective field theory. The CP-conserving and CP-violating interactions are treated on equal footing and we consider CP-violating one-, two-, and three-nucleon operators up to next-to-leading-order in the chiral power counting. In particular, we calculate for the first time EDM contributions induced by the CP-violating three-pion operator. We find that effects of CP-violating nucleon-nucleon contact interactions are larger than those found in previous studies based on phenomenological models for the CP-conserving nucleon-nucleon interactions. Our results which apply to any model of CP violation in the hadronic sector can be used to test various scenarios of CP violation. As examples, we study the implications of our results on the QCD $\\theta$-term and the minimal left-right symmetric model.
Magnetic properties of iron yoke laminations for SSC dipole magnets
S. A. Kahn; G. H. Morgan
1991-01-01
The authors examine the magnetic properties for the iron used in the SSC (Superconducting Super Collider) yoke laminations so that the accelerator tolerance 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, Hc. Requirements on the magnitude and the
NASA Astrophysics Data System (ADS)
Lebedev, A. V.
2015-01-01
Magnetic susceptibility measurements were carried out for magnetite-based fluids over a wide temperature range. The fluids were stabilized with commonly used surfactants (fatty acids) and new surfactants (polypropylene glycol and tallow acids). The coefficients of temperature dependence of the particle magnetic moments were determined by fitting of the measured and calculated values of magnetic susceptibility. The influence of the inter-particle dipole-dipole interaction on the susceptibility was taken into account in the framework of A.O. Ivanov's model. The corrections for thermal expansion were determined by density measurements of the carrier fluid. The obtained values of temperature coefficients correlate to the solidification temperature of the fluid samples. For fluids with a low solidification temperature the value of the temperature coefficient of particle magnetization coincides with its value for bulk magnetite.
Frequency generation by a magnetic vortex-antivortex dipole in spin-polarized current
Stavros Komineas
2012-03-05
A vortex-antivortex (VA) dipole may be generated due to a spin-polarized current flowing through a nano-aperture in a magnetic element. We study the vortex dipole dynamics using the Landau-Lifshitz equation in the presence of an in-plane applied magnetic field and 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 the two vortices and the external magnetic field. The nonzero skyrmion number of the dipole is responsible for both forces giving rise to rotational dynamics. The spin-torque acts to stabilize the vortex dipole motion at a definite vortex-antivortex separation distance. We give analytical and numerical results for the angular frequency of rotation and VA dipole features as functions of the parameters.
Magnetic field measurements of 1. 5 meter model SSC collider dipole magnets at Fermilab
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
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.
CryoEDM: A cryogenic experiment to measure the neutron electric dipole moment
NASA Astrophysics Data System (ADS)
van der Grinten, M. G. D.; CryoEDM Collaboration; Balashov, S. N.; Francis, V.; Green, K.; Iaydjiev, P. S.; Ivanov, S. N.; Khazov, A.; Tucker, M. A. H.; Wark, D. L.; Davidson, A.; Hardiman, M.; Harris, P. G.; Katsika, K.; Pendlebury, J. M.; Peeters, S. J. M.; Shiers, D. B.; Smith, P.; Townsley, C.; Wardell, I.; Clarke, C.; Henry, S.; Kraus, H.; McCann, M.; Geltenbort, P.; Yoshiki, Y.
2009-12-01
CryoEDM is an experiment that aims to measure the electric dipole moment (EDM) of the neutron to a precision of 10 -28 e cm. A description of CryoEDM, the apparatus, technologies and commissioning is presented.
Theory for electric dipole superconductivity with an application for bilayer excitons
Jiang, Qing-Dong; Bao, Zhi-qiang; Sun, Qing-Feng; Xie, X. C.
2015-01-01
Exciton superfluid is a macroscopic quantum phenomenon in which large quantities of excitons undergo the Bose-Einstein condensation. Recently, exciton superfluid has been widely studied in various bilayer systems. However, experimental measurements only provide indirect evidence for the existence of exciton superfluid. In this article, by viewing the exciton in a bilayer system as an electric dipole, we derive the London-type and Ginzburg-Landau-type equations for the electric dipole superconductors. By using these equations, we discover the Meissner-type effect and the electric dipole current Josephson effect. These effects can provide direct evidence for the formation of the exciton superfluid state in bilayer systems and pave new ways to drive an electric dipole current. PMID:26154838
Theory for electric dipole superconductivity with an application for bilayer excitons.
Jiang, Qing-Dong; Bao, Zhi-Qiang; Sun, Qing-Feng; Xie, X C
2015-01-01
Exciton superfluid is a macroscopic quantum phenomenon in which large quantities of excitons undergo the Bose-Einstein condensation. Recently, exciton superfluid has been widely studied in various bilayer systems. However, experimental measurements only provide indirect evidence for the existence of exciton superfluid. In this article, by viewing the exciton in a bilayer system as an electric dipole, we derive the London-type and Ginzburg-Landau-type equations for the electric dipole superconductors. By using these equations, we discover the Meissner-type effect and the electric dipole current Josephson effect. These effects can provide direct evidence for the formation of the exciton superfluid state in bilayer systems and pave new ways to drive an electric dipole current. PMID:26154838
Vakur B. Ertürk; Roberto G. Rojas; Kit Wing Lee
2004-01-01
Various arrays consisting of finite number of printed dipoles on electrically large dielectric coated circular cylinders are investigated using a hybrid method of moments\\/Green's function technique in the spatial domain. This is basically an \\
Can paramagnetic atoms in superfluid helium be used to search for permanent electric dipole moments?
M. Arndt; S. I. Kanorsky; A. Weis; T. W. Hänsch
1993-01-01
Large densities together with long trapping times have been observed for atoms immersed in He II. The feasibility of experiments searching for permanent electric dipole moments (PEDM) of paramagnetic atoms in He II is discussed.
Dipole-exchange modes in transversely magnetized ferromagnetic stripes
NASA Astrophysics Data System (ADS)
Arias, Rodrigo; Duan, Zheng; Krivorotov, Ilya
2014-03-01
We present a theory of dipole-exchange modes in transversely magnetized ferromagnetic stripes of rectangular cross sections: a comparison is made with experimental results on Permalloy stripes. The model applies to very thin stripes (of the order of the exchange length): the magnetization is considered uniform over their thickness, and we consider modes of long wavelength along the longitudinal direction of the stripes. An applied magnetic field saturates the stripes along the transverse direction, and we also consider the effect of the exchange and dipolar fields. Under these assumptions we obtain the frequencies and shapes of the modes either considering free or pinned boundary conditions. We obtain good agreement with measurements of the frequency spectra in Permalloy nano wires of several rectangular cross sections: this happens for modes with appreciable amplitude throughout the samples. There is frequency disagreement for edge modes due to limitations of the model, since the effects of roughness, corners and imperfections at the edges of the samples are quite relevant in this case. This work was supported by the NSF Materials World Network Program Grant No. DMR-1210850 and by DOE grant DE-FG02-84ER45083. Also, supported by ``Proyecto ICM FP10-061-F-FIC'', and ``Proyecto FONDECYT 1130192, Conicyt, Chile''.
ANALYTICAL CALCULATION OF STOKES PROFILES OF ROTATING STELLAR MAGNETIC DIPOLE
Martinez Gonzalez, M. J. [Instituto de Astrofisica de Canarias, Via Lactea s/n, 38200 La Laguna, Tenerife (Spain); Asensio Ramos, A. [Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife (Spain)
2012-08-20
The observation of the polarization emerging from a rotating star at different phases opens up the possibility to map the magnetic field in the stellar surface thanks to the well-known Zeeman-Doppler imaging. When the magnetic field is sufficiently weak, the circular and linear polarization profiles locally in each point of the star are proportional to the first and second derivatives of the unperturbed intensity profile, respectively. We show that the weak-field approximation (for weak lines in the case of linear polarization) can be generalized to the case of a rotating star including the Doppler effect and taking into account the integration on the stellar surface. The Stokes profiles are written as a linear combination of wavelength-dependent terms expressed as series expansions in terms of Hermite polynomials. These terms contain the surface-integrated magnetic field and velocity components. The direct numerical evaluation of these quantities is limited to rotation velocities not larger than eight times the Doppler width of the local absorption profiles. Additionally, we demonstrate that in a rotating star, the circular polarization flux depends on the derivative of the intensity flux with respect to the wavelength and also on the profile itself. Likewise, the linear polarization depends on the profile and on its first and second derivatives with respect to the wavelength. We particularize the general expressions to a rotating dipole.
A differential-fed magneto-electric dipole antenna for ultra-wideband applications
Mingjian Li; Kwai-Man Luk
2011-01-01
an ultra-wideband differential-fed magneto-electric dipole antenna with unidirectional radiation patterns is proposed in this paper. A novel parallel twin-L shaped differential feeding structure provides an ultra-wideband impedance matching. A unified gain can be realized by the modification of the magneto- electric dipole and using a rectangular cavity, instead of a normal ground plane. The antenna can achieve an impedance bandwidth
Zeng, Yong; Moloney, Jerome V
2009-09-15
We analytically study second-harmonic (SH) generation from thin metallic films with subwavelength noncentrosymmetric patterns. Because the thickness of the film is much smaller than the SH wavelength, retardation effects are negligible. The far-field SH intensities are thus dominated by an effective electric dipole. It is further demonstrated that internal bulk SH polarization density is comparable with its surface counterpart. The electric dipole, consequently, originates from the entire volume of the metallic membrane. PMID:19756124
Proposal for trapped-ion emulation of the electric dipole moment of neutral relativistic particles
NASA Astrophysics Data System (ADS)
Tenev, Tihomir G.; Ivanov, Peter A.; Vitanov, Nikolay V.
2013-02-01
The electric dipole moments of various neutral elementary particles, such as neutron, neutrinos, certain hypothetical dark matter particles, and others, are predicted to exist by the standard model of high-energy physics and various extensions of it. However, the predicted values are beyond the present experimental capabilities. We propose to simulate and emulate the electric dipole moment of neutral relativistic particles and the ensuing effects in the presence of an electrostatic field by emulation of an extended Dirac equation in ion traps.
The neutron electric dipole moment experiment at the FRM-II
NASA Astrophysics Data System (ADS)
Marino, Michael
2013-04-01
The discovery of a neutron electric dipole moment (nEDM) would provide an unambiguous indication of time violation in a fundamental system, and address one of the Sakharov conditions (CP-symmetry violation) necessary to explain the observed matter/antimatter asymmetry in the universe. Current experimental limitations on the nEDM are roughly 6 orders of magnitude above the Standard Model (SM) prediction and so searches for the nEDM provide powerful tests of physics beyond the SM. The nEDM experiment currently under construction at the FRM-II reactor in Munich is seeking to improve this limit up to 2 orders of magnitude. A contextual overview of the relevant physics will be given, and developments in the FRM-II nEDM experiment, including the recent installation of a world-record magnetically shielded room, will be presented.
Feasibility study of a 3He-magnetometer for neutron electric dipole moment experiments
NASA Astrophysics Data System (ADS)
Borisov, Yu; Heil, W.; Leduc, M.; Lobashev, V.; Otten, E. W.; Sobolev, Yu
2000-02-01
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.
Electric field and potential calculation for a bioelectric current dipole in an ellipsoid
Andrei Irimia
2005-01-01
Computer-based modelling in ellipsoidal geometry can be useful in electro- encephalography and gastrography due to the resemblance of the human brain and stomach to an ellipsoid. Both theoretically and computationally, the bioelectric current dipole model is important for the study of electrical activity in these two organs. Computing the electric potential phi and electric field E due to a current
Prospects for electric-dipole-moment measurements in radon
NASA Astrophysics Data System (ADS)
Chupp, Timothy
2014-09-01
A permanent electric dipole moment (EDM) of a particle or system would arise due to breaking of time-reversal, or equivalently CP symmetry. Experiments to date on the neutron, atoms and molecules have only set upper limits on EDMs. New techniques and systems in which the effects of CP violation would be greatly enhanced are driving the field forward. Systems that may be favorable for significant advances include 221,223Rn, where the combination of octupole collectivity and relatively closely spaced opposite parity levels would increase the nuclear Schiff moment by one or more orders of magnitude compared to other diamagnetic atoms, i.e. 199Hg. We have developed and tested at TRIUMF-ISAC an on-line EDM experiment that will collect and make measurements on the short-lived species (T1 / 2 ~ 25 m) featuring high-efficiency collection and spin-exchange polarization of noble-gas isotopes. Nuclear-structure issues include determining the octupole collectivity as well as the spacing of opposite parity levels. Experiments are underway at ISOLDE, NSCL and ISAC to study the nuclear structure of isotopes in this mass region. I will report on progress and comment on how we learn about the basic physical parameters of CP violation from EDM measurements. A permanent electric dipole moment (EDM) of a particle or system would arise due to breaking of time-reversal, or equivalently CP symmetry. Experiments to date on the neutron, atoms and molecules have only set upper limits on EDMs. New techniques and systems in which the effects of CP violation would be greatly enhanced are driving the field forward. Systems that may be favorable for significant advances include 221,223Rn, where the combination of octupole collectivity and relatively closely spaced opposite parity levels would increase the nuclear Schiff moment by one or more orders of magnitude compared to other diamagnetic atoms, i.e. 199Hg. We have developed and tested at TRIUMF-ISAC an on-line EDM experiment that will collect and make measurements on the short-lived species (T1 / 2 ~ 25 m) featuring high-efficiency collection and spin-exchange polarization of noble-gas isotopes. Nuclear-structure issues include determining the octupole collectivity as well as the spacing of opposite parity levels. Experiments are underway at ISOLDE, NSCL and ISAC to study the nuclear structure of isotopes in this mass region. I will report on progress and comment on how we learn about the basic physical parameters of CP violation from EDM measurements. T. Chupp (spokesman), C. Svensson (spokesman), S. Degenkolb, R. Dunlop, P. Fierlinger, A. Garnsworthy, F. Gong, P. Garret, G. Hackman, M. Hayden, M. Pearson, R. Picker, E. Rand, J. Singh, N. Sachdeva.
Permanent dipole magnets for the 8 GeV transfer line at FNAL
Glass, H.D.; Brown, B.C.; Foster, G.W.; Fowler, W.B.; Haggard, J.E. [and others
1997-06-01
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.
Noncommutative QED and anomalous dipole moments
Ihab. F. Riad; M. M. Sheikh-Jabbari
2000-01-01
We study QED on noncommutative spaces, NCQED. In particular we present the detailed calculation for the noncommutative electron-photon vertex and show that the Ward identity is satisfied. We discuss that in the noncommutative case moving electron will show electric dipole effects. In addition, we work out the electric and magnetic dipole moments up to one loop level. For the magnetic
The 9.1-T iron-free Nb-Ti dipole magnet with pancake windings
W. Gilbert; S. Caspi; W. Hassenzahl; R. Meuser; C. Peters; J. Rechen; R. Schafer; C. Taylor; R. Wolgast
1983-01-01
An eight-pancake Nb-Ti dipole magnet, with bent up ends, called D-108B has been built and tested. This magnet is a Nb-Ti version of a Nb3Sn magnet designed to produce a 10-tesla dipole field in a 40 mm diameter aperture. The pancake design is used for the heavy 12,000 ampere Nb3Sn cable because of the mechanical difficulty in winding such a
Assembly and Test of HD2, a 36 mm Bore High Field Dipole Magnet
Paolo Ferracin; Brad Bingham; Shlomo Caspi; D. W. Cheng; Daniel R. Dietderich; Helene Felice; Arno Godeke; A. R. Hafalia; C. R. Hannaford; J. M. Joseph; A. F. Lietzke; Juan Lizarazo; GianLuca Sabbi; Frederic Trillaud; X. R. Wang
2009-01-01
We report on the fabrication, assembly, and test of the Nb3Sn dipole magnet HD2. The magnet, aimed at demonstrating the application of Nb3Sn superconductor in high field accelerator-type dipoles, features a 36 mm clear bore surrounded by block-type coils with tilted ends. The coil design is optimized to minimize geometric harmonics in the aperture and the magnetic peak field on
Shogo Kozaki
1977-01-01
Recent analytical studies of ULF electromagnetic fields in the atmosphere are reviewed. These fields have their origin in the discharge of thunderclouds. The problem for a vertical electrical dipole source played in an atmosphere where the conductivity increases exponentially with altitude is described. The analytical expressions for the electric and magnetic field, which vary in time and space, are approximately
Electric dipole moments and polarizability in the quark-diquark model of the neutron
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
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.
Graded High Field Nb3Sn Dipole Magnets
Caspi, S.; Ferracin, P.; Gourlay, S.
2007-06-01
Dipole magnets with fields beyond 16T will require superconducting coils that are at least 40 mm thick, an applied pres-stress around 150 MPa and a protection scheme for stored energy in the range of 1-2 MJ/m. The coil size will have a direct impact on the overall magnet cost and the stored energy will raise new questions on protection. To reduce coil size and minimize risk, the coil may have to be graded. Grading is achieved by splitting the coil into several layers with current densities that match the short sample field in each layer. Grading, especially at high fields, can be effective; however it will also significantly raise the stress. In this paper we report on the results of a study on the coil size and field relation to that of the stress and stored energy. We then extend the results to graded coils and attempt to address high stress issues and ways to reduce it.
MAGNETIC FIELD MEASUREMENTS OF HD2, A HIgh Nb3Sn DIPOLE MAGNET
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
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.
Solar rotating magnetic dipole?. [around axis perpendicular to rotation axis of the sun
NASA Technical Reports Server (NTRS)
Antonucci, E.
1974-01-01
A magnetic dipole rotating around an axis perpendicular to the rotation axis of the sun can account for the characteristics of the surface large-scale solar magnetic fields through the solar cycle. The polarity patterns of the interplanetary magnetic field, predictable from this model, agree with the observed interplanetary magnetic sector structure.
Fabrication and test results of a twin-aperture superconducting dipole model magnet for LHC
H. Boschman; H. J. Israel; R. L. Dubbeldam; D. Leroy; P. Rohmig
1993-01-01
In the research and development program for the Large Hadron Collider (LHC) project at CERN the construction of superconducting dipole magnets with a twin aperture plays an important role. The design value of the magnetic field produced by these magnets is 10 T at superfluid helium temperatures below 2 K. One of the 1-m-long model magnets in the program has
Electromagnetic Design Study for a Large Bore 15T Superconducting Dipole Magnet
N Schwerg; C Völlinger; Arnaud Devred; H Henke
2005-01-01
In the framework of research and development (R&D) activities at CERN the Next European Dipole (NED) program is one which is to the development of a high-field dipole magnet using Nb_3Sn superconductors. Part of the NED activities is a design study of different possible dipole configurations which is shared amongst the collaborating institutes. This thesis covers the electromagnetic design study
H. Yan; B. Plaster
2011-04-07
Geometric-phase-induced false electric dipole moment (EDM) signals, resulting from interference between magnetic field gradients and particle motion in electric fields, have been studied extensively in the literature, especially for neutron EDM experiments utilizing stored ultracold neutrons and co-magnetometer atoms. Previous studies have considered particle motion in the transverse plane perpendicular to the direction of the applied electric and magnetic fields. We show, via Monte Carlo studies, that motion along the field direction can impact the magnitude of this false EDM signal if the wall surfaces are rough such that the wall collisions can be modeled as diffuse, with the results dependent on the size of the storage cell's dimension along the field direction.
Dipolar Radicals in Crossed Electric and Magnetic Fields
John L. Bohn; Goulven Quéméner
2013-01-11
Paramagnetic, dipolar Hund's case-a radicals are considered in the presence of arbitrary, non-collinear combinations of electric and magnetic fields. The field-dependent part of the Hamiltonian is found to be exactly diagonalizable, and described by quantum numbers given by the projection of the molecule's total angular momentum along a space-fixed axis that is determined by both the fields and the electric and magnetic dipole moments of the molecule. In cases of strong fields, this procedure identifies a set of quantum numbers for the molecule in crossed fields. We dub this set a "Hund's case-X" basis.
Nb3Sn accelerator magnet technology scale up using cos-theta dipole coils
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
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.
Self-force on an electric dipole in the spacetime of a cosmic string
Muniz, C.R., E-mail: celiomuniz@yahoo.com [Grupo de Física Teórica (GFT), Universidade Estadual do Ceará, UECE-FECLI, Iguatu, Ceará (Brazil); Bezerra, V.B., E-mail: valdir@ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, CEP 58051-970, João Pessoa, PB (Brazil)
2014-01-15
We calculate the electrostatic self-force on an electric dipole in the spacetime generated by a static, thin, infinite and straight cosmic string. The electric dipole is held fixed in different configurations, namely, parallel, perpendicular to the cosmic string and oriented along the azimuthal direction around this topological defect, which is stretched along the z axis. We show that the self-force is equivalent to an interaction of the electric dipole with an effective dipole moment which depends on the linear mass density of the cosmic string and on the configuration. The plots of the self-forces as functions of the parameter which determines the angular deficit of the cosmic string are shown for those different configurations. -- Highlights: •Review of regularized Green’s function applied to the problem. •Self-force on an electric dipole in the string spacetime for some orientations. •Representation via graphs of the self-forces versus angular parameter of the cosmic string. •Self-force induced by the string seen as an interaction between two dipoles. •Discussion about the superposition principle in this non-trivial background.
Full QCD calculation of neutron electric dipole moment with the external electric field method
E. Shintani; S. Aoki; Y. Kuramashi
2008-07-22
We have calculated the neutron electric dipole moment (NEDM) in the presence of the CP violating $\\theta$ term in lattice QCD with 2-flavor dynamical clover quarks, using the external electric field method. Accumulating a large number of statistics by the averages over 16 different source points and over forward and backward nucleon propagators, we have obtained non-zero signals of neutron and proton EDM beyond one standard deviation at each quark mass in full QCD. We have investigated the quark mass dependence of nucleon EDM in full QCD, and have found that nucleon EDM in full QCD does not decrease toward the chiral limit, as opposed to the theoretical expectation. We briefly discuss possible reasons for this behavior.
Polarizable vacuum analysis of electric and magnetic fields
Xing-Hao Ye
2009-08-22
The electric and magnetic fields are investigated on the basis of quantum vacuum. The analysis of the electromagnetic energy and force indicates that an electric field is a polarized distribution of the vacuum virtual dipoles, and that a magnetic field in vacuum is a rearrangement of the vacuum polarization. It means that an electromagnetic wave is a successional changing of the vacuum polarization in space. Also, it is found that the average half length of the virtual dipoles around an elementary charge is a=2.8 *10^(-15)m. The result leads to the step distribution of the field energy around an electron, the relation between the fine structure constant and the vacuum polarization distribution, and an extremely high energy density of the electromagnetic field.
Magnetic designs of 2-in-1 Nb3Sn dipole magnets for VLHC
Vadim V. Kashikhin; Alexander V. Zlobin
2001-01-01
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
Direct detection of light anapole and magnetic dipole DM
NASA Astrophysics Data System (ADS)
Del Nobile, Eugenio; Gelmini, Graciela B.; Gondolo, Paolo; Huh, Ji-Haeng
2014-06-01
We present comparisons of direct detection data for ``light WIMPs'' with an anapole moment interaction (ADM) and a magnetic dipole moment interaction (MDM), both assuming the Standard Halo Model (SHM) for the dark halo of our galaxy and in a halo-independent manner. In the SHM analysis we find that a combination of the 90% CL LUX and CDMSlite limits or the new 90% CL SuperCDMS limit by itself exclude the parameter space regions allowed by DAMA, CoGeNT and CDMS-II-Si data for both ADM and MDM. In our halo-independent analysis the new LUX bound excludes the same potential signal regions as the previous XENON100 bound. Much of the remaining signal regions is now excluded by SuperCDMS, while the CDMSlite limit is much above them. The situation is of strong tension between the positive and negative search results both for ADM and MDM. We also clarify the confusion in the literature about the ADM scattering cross section.
NSDL National Science Digital Library
2010-02-10
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
Magnetic Fields Analogous to electric field, a magnet
Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University
Magnetic Fields Analogous to electric field, a magnet produces a magnetic field, B Set up a B field two ways: Moving electrically charged particles Current in a wire Intrinsic magnetic field Basic characteristic of elementary particles such as an electron #12;Magnetic Fields Magnetic field lines Direction
Mohamed A. Mohamed; Edward F. Kuester; Melinda Piket-May; Christopher L. Holloway
2009-01-01
In this paper, a study is made of the electrostatic potential and fleld of an electric dipole located in the interface between two dielectric regions. When the dipole is oriented perpendicular to the interface, the detailed position of the charges of the dipole relative to the location of the interface has a signiflcant efiect on the value of the fleld
Radiation effects in a muon collider ring and dipole magnet protection
N. V. Mokhov; V. V. Kashikhin; I. Novitski; A. V. Zlobin
2011-01-01
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
TEST RESULTS FOR INITIAL PRODUCTION OF LHC INSERTION REGION DIPOLE MAGNETS*
Large Hadron Collider Program
TEST RESULTS FOR INITIAL PRODUCTION OF LHC INSERTION REGION DIPOLE MAGNETS* J. F. Muratore , M at 7.56 TeV. The magnets will be tested at 4.5 K using either forced flow supercritical helium or liquid helium. This paper reports the results of tests of four D1 magnets, including spontaneous quench
K. Prabhakar Rao; K. Mallick
2001-01-01
A C++ program is developed to compute the normalized vertical magnetic field of a vertical magnetic dipole source placed on the surface of the transitional earth. Three classes with member functions are designed to compute the kernel function, Hankel transform integral and the normalized vertical magnetic field. The digital filter technique is used to evaluate the Hankel integral. The program
Effective electric field of molecules of observation experiment of electron electric dipole moment
NASA Astrophysics Data System (ADS)
Fukuda, Masahiro; Soga, Kota; Senami, Masato; Tachibana, Akitomo
2014-09-01
Heavy polar diatomic molecules are the most promising candidates for experiments of the electric dipole moment (EDM) of the electron, which is a hopeful and inexpensive probe of physics beyond the standard model. The upper bound of the electron EDM, de, is determined by the energy shift by the EDM, which is the product of de and the effective electric field Eeff . Eeff , which cannot be measured experimentally, must be determined by ab initio computations for each molecule based on relativistic quantum theory. Relativistic and correlation effects are essentially important for accurate computations of heavy atoms and molecules. For the former effects, the four-component Dirac equation should be solved for the inclusion of the relativistic term, such as the spin-orbit interaction, while post Hartree-Fock computations, such as configuration interaction (CI), are required for the latter effects. These two treatments consume large computational resources, and hence the value of the effective electric field has not been settled yet. In this work, we investigate the effective electric field for the electron EDM in diatomic molecules such as YbF, which is a representative one for experiments of the electron EDM.
Guarendi, Andrew N.; Chandy, Abhilash J.
2013-01-01
Numerical simulations of magnetohydrodynamic (MHD) hypersonic flow over a cylinder are presented for axial- and transverse-oriented dipoles with different strengths. ANSYS CFX is used to carry out calculations for steady, laminar flows at a Mach number of 6.1, with a model for electrical conductivity as a function of temperature and pressure. The low magnetic Reynolds number (?1) calculated based on the velocity and length scales in this problem justifies the quasistatic approximation, which assumes negligible effect of velocity on magnetic fields. Therefore, the governing equations employed in the simulations are the compressible Navier-Stokes and the energy equations with MHD-related source terms such as Lorentz force and Joule dissipation. The results demonstrate the ability of the magnetic field to affect the flowfield around the cylinder, which results in an increase in shock stand-off distance and reduction in overall temperature. Also, it is observed that there is a noticeable decrease in drag with the addition of the magnetic field. PMID:24307870
Guarendi, Andrew N; Chandy, Abhilash J
2013-01-01
Numerical simulations of magnetohydrodynamic (MHD) hypersonic flow over a cylinder are presented for axial- and transverse-oriented dipoles with different strengths. ANSYS CFX is used to carry out calculations for steady, laminar flows at a Mach number of 6.1, with a model for electrical conductivity as a function of temperature and pressure. The low magnetic Reynolds number (<1) calculated based on the velocity and length scales in this problem justifies the quasistatic approximation, which assumes negligible effect of velocity on magnetic fields. Therefore, the governing equations employed in the simulations are the compressible Navier-Stokes and the energy equations with MHD-related source terms such as Lorentz force and Joule dissipation. The results demonstrate the ability of the magnetic field to affect the flowfield around the cylinder, which results in an increase in shock stand-off distance and reduction in overall temperature. Also, it is observed that there is a noticeable decrease in drag with the addition of the magnetic field. PMID:24307870
Results from a Prototype Permanent Magnet Dipole-Quadrupole Hybrid for the PEP-II B-Factory
M. Sullivan; G. Bowden; S. Ecklund; D. Jensen; M. Nordby; A. Ringwall; Z. R. Wolf
2001-01-01
We describe the construction of a prototype hybrid permanent magnet dipole and quadruple. The magnet consists of two concentric rings of SmCo magnetic material 5 cm in length. The outer ring is made of 16 uniformly magnetized blocks assembled as a Halbach dipole and the inner ring has 32 blocks oriented in a similar fashion so as to generate a
Results from a prototype permanent magnet dipole-quadrupole hybrid for the PEP-II B-factory
M. Sullivan; G B Bowden; S D Ecklund; D. Jensen; M E Nordby; A D Ringwall; Z. Wolf
1997-01-01
We describe the construction of a prototype hybrid permanent magnet dipole and quadrupole. The magnet consists of two concentric rings of Sm2Co17 magnetic material 5 cm in length. The outer ring is made of 16 uniformly magnetized blocks assembled as a Halbach dipole and the inner ring has 32 blocks oriented in a similar fashion so as to generate a
Fabrication and test results of a Nb3Sn superconducting racetrack dipole magnet
K. Chow; D. R. Dietderich; S. A. Gourlay; R. Gupta; W. Harnden; A. F. Lietzke; A. D. McInturff; G. A. Millos; L. Morrison; R. M. Scanlan
1999-01-01
A “proof-of-principle” Nb3Sn superconducting dual-bore dipole magnet was built from racetrack coils, as a first step in a program to develop an economical, 15 Tesla, accelerator-quality magnet. The mechanical design and magnet fabrication procedures are discussed. No training was required to achieve temperature-dependent plateau currents, despite several thermal cycles that involved partial magnet disassembly and substantial pre-load variations. Subsequent magnets
Unraveling models of CP violation through electric dipole moments of light nuclei
W. Dekens; J. de Vries; J. Bsaisou; W. Bernreuther; C. Hanhart; Ulf-G. Meißner; A. Nogga; A. Wirzba
2014-07-21
We show that the proposed measurements of the electric dipole moments of light nuclei in storage rings would put strong constraints on models of flavor-diagonal CP violation. Our analysis is exemplified by a comparison of the Standard Model including the QCD theta term, the minimal left-right symmetric model, a specific version of the so-called aligned two-Higgs doublet model, and briefly the minimal supersymmetric extension of the Standard Model. By using effective field theory techniques we demonstrate to what extend measurements of the electric dipole moments of the nucleons, the deuteron, and helion could discriminate between these scenarios. We discuss how measurements of electric dipole moments of other systems relate to the light-nuclear measurements.
Production of trilobite Rydberg molecule dimers with kilo-Debye permanent electric dipole moments
NASA Astrophysics Data System (ADS)
Booth, D.; Rittenhouse, S. T.; Yang, J.; Sadeghpour, H. R.; Shaffer, J. P.
2015-04-01
Permanent electric dipole moments are important for understanding symmetry breaking in molecular physics, control of chemical reactions, and realization of strongly correlated many-body quantum systems. However, large molecular permanent electric dipole moments are challenging to realize experimentally. We report the observation of ultralong-range Rydberg molecules with bond lengths of ~100 nanometers and kilo-Debye permanent electric dipole moments that form when an ultracold ground-state cesium (Cs) atom becomes bound within the electronic cloud of an extended Cs electronic orbit. The electronic character of this hybrid class of “trilobite” molecules is dominated by degenerate Rydberg manifolds, making them difficult to produce by conventional photoassociation. We used detailed coupled-channel calculations to reproduce their properties quantitatively. Our findings may lead to progress in ultracold chemistry and strongly correlated many-body physics.
Electric dipole moment of diatomic molecules by configuration interaction. IV.
NASA Technical Reports Server (NTRS)
Green, S.
1972-01-01
The theory of basis set dependence in configuration interaction calculations is discussed, taking into account a perturbation model which is valid for small changes in the self-consistent field orbitals. It is found that basis set corrections are essentially additive through first order. It is shown that an error found in a previously published dipole moment calculation by Green (1972) for the metastable first excited state of CO was indeed due to an inadequate basis set as claimed.
A Ten-Fold Improvement to the Limit of the Electron Electric Dipole Moment
NASA Astrophysics Data System (ADS)
Spaun, Benjamin Norman
The Standard Model of particle physics is wonderfully successful in its predictions but known to be incomplete. It fails to explain the existence of dark matter, and the fact that a universe made of matter survived annihilation with antimatter following the big bang. Extensions to the Standard Model, such as weak-scale Supersymmetry, provide explanations for some of these phenomena by asserting the existence of new particles and new interactions that break symmetry under time-reversal. These theories predict a small, yet potentially measurable electron electric dipole moment (EDM), de, that also violates time-reversal symmetry. Here, we report a new measurement of the electron EDM in the polar molecule thorium monoxide (ThO): de = -2.1 pm 3.7stat pm 2.5syst x 10-29 e cm, which corresponds to an upper limit of de| < 8.7 x 10 -29 e cm with 90 % confidence. This is more than an order of magnitude improvement in sensitivity compared to the previous limit. This result sets strong constraints on new physics at an energy scale (TeV) at least as high as that directly probed by the Large Hadron Collider. The unprecedented precision of this EDM measurement was achieved by using the high effective electric field within ThO to greatly magnify the EDM signal. Valence electrons travel relativistically near the heavy thorium nucleus and experience an effective electric field of about 100 GV/cm, millions of times larger than any static laboratory field. The reported measurement is a combination of millions of separate EDM measurements performed with billions of ThO molecules in a cold, slow buffer gas beam. Other features of ThO, such as a near-zero magnetic moment and high electric polarizability, allow potential systematic errors to be drastically suppressed and ensure the accuracy of our measurement.
Electric dipole response of {sup 208}Pb and constraints on the symmetry energy
Tamii, A. [Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka, Ibaraki 567-0047 (Japan)
2014-05-02
The electric dipole (E1) response of {sup 208}Pb has been precisely determined by measuring polarized proton inelastic scattering at very forward angles including zero degrees. The electric dipole polarizability, that is defined as the inverse energy-weighted sum rule of the E1 reduced transition strength, has been extracted as ?{sub D} = 20.1 ±0.6 fm{sup 3}. A constraint band has been extracted in the plane of the symmetry energy (J) and its slope parameter (L) at the saturation density.
P- and T-Violating Lagrangians in Chiral Effective Field Theory and Nuclear Electric Dipole Moments
J. Bsaisou; Ulf-G. Meißner; A. Nogga; A. Wirzba
2015-04-30
A scheme to derive hadronic interactions induced by effective multi-quark terms is presented within the framework of chiral effective field theory. It is employed to work out the list of parity- and time-reversal-symmetry-violating hadronic interactions that are relevant for the computation of nuclear contributions to the electric dipole moments of the hydrogen-2, helium-3 and hydrogen-3 nuclei. We also derive the scattering and Faddeev equations required to compute electromagnetic form factors in general and electric dipole moments in particular.
Electric and Magnetic Forces: Electromagnetism
NSDL National Science Digital Library
National Science Teachers Association (NSTA)
2008-10-30
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.
Electric and magnetic field exposure
S. S. Sussman
1988-01-01
The possible health hazards of low-level, power line frequency (50\\/60 Hz) electric and magnetic fields are considered. The historical background to this concern is briefly discussed. The types of studies being carried out and the results so far are summarized. It is concluded that while the scientific evidence on field effects is inconclusive, inferences of health effects justify further evaluation
Polarity reversals and tilt of the Earth's magnetic dipole
NASA Technical Reports Server (NTRS)
Dolginov, A. Z.
1993-01-01
There is evidence that the terrestrial magnetic field is connected with the Earth's mantle: (1) there are magnetic anomalies that do not take part in the westward drift of the main field, but are fixed with respect to the mantle; (2) the geomagnetic pole position flips in a particular way by preferred meridional paths during a reversal; and (3) magnetic polarity reversals are correlated with the activations of geological processes. These facts may be explained if we take into account that a significant horizontal temperature gradient can exist in the top levels of the liquid core because of the different thermoconductivity of the different areas of the core-mantle boundary. These temperature inhomogeneities can penetrate the core because fluxes along the core boundary (the thermal wind) can be strongly suppressed by a small redistribution of the chemical composition in the top of the core. The nonparallel gradients of the temperature, density, and composition on the top of the core create a curled electric field that produces a current and a magnetic field. This seed-field can be amplified by motions in the core. The resulting field does not forget the seed-field distribution and in this way the field on the Earth surface (that can be created only in regions with high conductivity, i.e. in the core) is connected with the core-mantle boundary. Contrary to the usual approach to the dynamo problem, we will take into account that the seed field of thermoelectric origin is acting not only at some initial moment of time but permanently.
The dynamics of high energy density plasma jets magnetized by large dipole magnetic fields
NASA Astrophysics Data System (ADS)
Gourdain, Pierre; Byvank, Tom; Hammer, Dave; Kusse, Bruce; Seyler, Charlie; Bland, Simon; Lebedev, Sergey; Swadling, George
2014-10-01
Astrophysical plasma jets expelled by proto-stars or galactic nuclei are often magnetized by the magnetic field that the star or galaxy generates. This field resembles the one of a dipole and, while strong near the celestial body, the field decays rapidly away from the source. Experimental observations of supersonic high energy density plasma jets generated in the laboratory by radial foils have shown that the field impacts strongly the dynamics of the jet. Such jets share some similarities with astrophysical jets in the magneto-hydrodynamics sense, e.g. large Reynolds, magnetic Reynolds and Peclet numbers. This work shows how a dipole field generated at the base of the supersonic jet affects the plasma dynamics. In regions where the plasma beta is low (near the base of the jet), the jet is conical. At higher altitudes, where the beta is high, the jet is strongly collimated. Numerical computations highlight the mechanisms responsible for such transitions. Research supported by NSF Grant # PHY-1102471, the DOE Grant # DE-SC0002151 and the NNSA/DOE Cooperative Agreement DE-NA0001836 and DE-NA0001847.
Reversals of the solar magnetic dipole in the light of observational data and simple dynamo models
NASA Astrophysics Data System (ADS)
Pipin, V. V.; Moss, D.; Sokoloff, D.; Hoeksema, J. T.
2014-07-01
Context. Observations show that the photospheric solar magnetic dipole usually does not vanish during the reversal of the solar magnetic field, which occurs in each solar cycle. In contrast, mean-field solar dynamo models predict that the dipole field does become zero. In a recent paper it was suggested that this contradiction could be explained as a large-scale manifestation of small-scale magnetic fluctuations of the surface poloidal field. Aims: Our aim is to confront this interpretation with the available observational data. Methods: Here we compare this interpretation with Wilcox Solar Observatory (WSO) photospheric magnetic field data in order to determine the amplitude of magnetic fluctuations required to explain the phenomenon and to compare the results with predictions from a simple dynamo model which takes these fluctuations into account. Results: We demonstrate that the WSO data concerning the magnetic dipole reversals are very similar to the predictions from our very simple solar dynamo model, which includes both mean magnetic field and fluctuations. The ratio between the rms value of the magnetic fluctuations and the mean field is estimated to be about 2, in reasonable agreement with estimates from sunspot data. The reversal epoch, during which the fluctuating contribution to the dipole is larger than that from the mean field, is about 4 months. The memory time of the fluctuations is about 2 months. Observations demonstrate that the rms of the magnetic fluctuations is strongly modulated by the phase of the solar cycle. This gives additional support to the concept that the solar magnetic field is generated by a single dynamo mechanism rather than also by independent small-scale dynamo action. A suggestion of a weak nonaxisymmetric magnetic field of a fluctuating nature arises from the analysis, with a lifetime of about 1 year. Conclusions: The behaviour of the magnetic dipole during the reversal epoch gives valuable information about details of solar dynamo action.
Updating the neutron electric dipole moment in a fourth generation standard model
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
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.
Quench performance of Fermilab/General Dynamics built full length SSC collider dipole magnets
Strait, J.; Orris, D.; Mazur, P.O.; Bleadon, M.; Bossert, R.; Carson, J.; Delchamps, S.W.; Gourlay, S.; Hanft, R.; Koska, W.; Kuchnir, M.; Lamm, M.J.; Ozelis, J.; Wake, M. [Fermi National Accelerator Lab., Batavia, IL (United States); Devred, A.; DiMarco, J.; Kuzminski, J.; Nah, W.; Ogitsu, T.; Puglisi, M.; Tompkins, J.C.; Yu, Y.; Zhao, Y.; Zheng, H. [Superconducting Super Collider Lab., Dallas, TX (United States)
1992-04-01
In this paper we present results of quench testing of full length SSC dipole magnets at Fermilab. The data are from the first six of a series of thirteen 15 m long, 50 mm aperture SSC dipole magnets which are being built and tested at Fermilab. These magnets were designed jointly by Fermilab, Brookhaven Laboratory, Lawrence Berkeley Laboratory and the SSC laboratory. Among the major goals for this series of magnets are to transfer magnet production technology to the lead vendor for the Collider Dipole Magnet, the General Dynamics Corporation, and to demonstrate industrial production by the vendor. The first magnet in the series, DCA311, was built by Fermilab technicians to establish assembly procedures. The second magnet, DCA312, was the ``technology transfer magnet`` and was built jointly by Fermilab and General Dynamics technicians. The next seven, DCA313- 319 are being built by General Dynamics personnel using Fermilab facilities and procedures. However, Fermilab personnel still operate the major tooling, provide the welders, perform assembly of items that would not be part of production magnets (e.g. voltage taps), and oversee the QA program. Five of these 7 GD-built magnets will be used in the Accelerator Systems String Test (ASST) to be carried out in Dallas later this year. The last four magnets, DCA320-323, are being built by Fermilab alone.
A. Kovalenko; N. Agapov; V. Bartenev; A. Donyagin; I. Eliseeva; H. Khodzhibagiyan; G. Kuznetsov; A. Smirnov; M. Voevodin; G. Moritz
2004-01-01
New experimental results from the investigation of a model superferric Nuclotron-type dipole and quadrupole magnets are presented. The magnets operate at pulse repetition rate f = 1 Hz, providing the peak magnetic field B = 2 T and the field gradient G = 34 T\\/m in the dipoles and quadrupoles respectively. The superconducting coil is made from a hollow multi-filamentary
Neutron electric dipole moment with external electric field method in lattice QCD
NASA Astrophysics Data System (ADS)
Shintani, E.; Aoki, S.; Ishizuka, N.; Kanaya, K.; Kikukawa, Y.; Kuramashi, Y.; Okawa, M.; Ukawa, A.; Yoshié, T.
2007-02-01
We discuss a possibility that the neutron electric dipole moment (NEDM) can be calculated in lattice QCD simulations in the presence of the CP-violating ? term. In this paper we measure the energy difference between spin-up and spin-down states of the neutron in the presence of a uniform and static external electric field. We first test this method in quenched QCD with the renormalization group improved gauge action on a 163×32 lattice at a-1?2GeV, employing two different lattice fermion formulations, the domain-wall fermion and the clover fermion for quarks, at relatively heavy quark mass (mPS/mV?0.85). We obtain nonzero values of the NEDM from calculations with both fermion formulations. We next consider some systematic uncertainties of our method for the NEDM, using 243×32 lattice at the same lattice spacing only with the clover fermion. We finally investigate the quark mass dependence of the NEDM and observe a nonvanishing behavior of the NEDM toward the chiral limit. We interpret this behavior as a manifestation of the pathology in the quenched approximation.
Neutron electric dipole moment with external electric field method in lattice QCD
E. Shintani; S. Aoki; N. Ishizuka; K. Kanaya; Y. Kikukawa; Y. Kuramashi; M. Okawa; A. Ukawa; T. Yoshié
2007-02-24
We discuss a possibility that the Neutron Electric Dipole Moment (NEDM) can be calculated in lattice QCD simulations in the presence of the CP violating $\\theta$ term. In this paper we measure the energy difference between spin-up and spin-down states of the neutron in the presence of an uniform and static external electric field. We first test this method in quenched QCD with the RG improved gauge action on a $16^3\\times 32$ lattice at $a^{-1}\\simeq$ 2 GeV, employing two different lattice fermion formulations, the domain-wall fermion and the clover fermion for quarks, at relatively heavy quark mass $(m_{PS}/m_V \\simeq 0.85)$. We obtain non-zero values of NEDM from calculations with both fermion formulations. We next consider some systematic uncertainties of our method for NEDM, using $24^3\\times 32$ lattice at the same lattice spacing only with the clover fermion. We finally investigate the quark mass dependence of NEDM and observe a non-vanishing behavior of NEDM toward the chiral limit. We interpret this behavior as a manifestation of the pathology in the quenched approximation.
Measurement of the Electric Dipole Polarizabilities of Alkali Halide Dimers
Robert Louis Kremens Jr.
1981-01-01
An electric field deflection method has been used to measure the space average polarizabilities of the dimers of the alkali halide salts of rubidium, cesium, potassium, and chlorine, flourine, bromine and iodine. The experimental procedure consisted of passing an effusive thermal beam of molecules through a region of inhomogeneous electric field and studying the deflection pattern obtained at the detector.
Modification of cos theta coil shape in superconducting dipole magnets for reducing the coil size
P. R. Sarma; N. Ibomcha; R. K. Bhandari
2005-01-01
In coil-dominated superconducting dipole magnets the coil size and hence the cost of the magnet can be reduced by optimizing the shape of the coil. We have used the variational calculus and a random search technique to show that the coil shape markedly deviates from the conventional cos theta design when one reduces the coil size while holding the field
Modification of cos ? coil shape in superconducting dipole magnets for reducing the coil size
P. R. Sarma; N. Ibomcha; R. K. Bhandari
2005-01-01
In coil-dominated superconducting dipole magnets the coil size and hence the cost of the magnet can be reduced by optimizing the shape of the coil. We have used the variational calculus and a random search technique to show that the coil shape markedly deviates from the conventional cos ? design when one reduces the coil size while holding the field
Design and Test of a Nb3Sn Subscale Dipole Magnet for Training Studies
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
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.
Revisiting the Calculation of the Neutron Electric Dipole Moment with the QCD Sum Rule Method
NASA Astrophysics Data System (ADS)
Nagata, Natsumi
We study the neutron electric dipole moment in the presence of the CP-violating operators up to the dimension five in terms of the QCD sum rules. By using input parameters obtained from the lattice simulation, we derive a conservative limit for the contributions of the CP violating operators.
An upper limit to the electric dipole moment of the neutron from lattice QCD
NASA Astrophysics Data System (ADS)
Allés, B.; D'Elia, M.; Di Giacomo, A.
2007-02-01
A linear increase with the volume of the topological susceptibility can signal spontaneous breaking of parity P and time inversion T, due to a nonzero vacuum expectation value of the topological charge Q. Such a breaking would produce a nonzero electric dipole moment of the neutron, d n. An upper limit to d n is derived from numerical simulations at increasing volumes.
A Comparative Study of Radio Wave Propagation Over the Earth Due to a Vertical Electric Dipole
Ting Fei; Le-Wei Li; Tat-Soon Yeo; Hai-Long Wang; Qun Wu
2007-01-01
A comparative study of the electromagnetic field excited by a vertical electric dipole on the Earth is presented. Four sets of formulas for both the planar Earth model and the spherical Earth model (of large radius) are compared to find out their valid ranges. Numerical computations are also carried out specifically for a three-layered Earth model. For the planar Earth
The 2H electric dipole moment in a separable potential approach
Gibson, Benjamin [Los Alamos National Laboratory; Afnan, I. R. [FLINDERS UNIV.
2009-01-01
Measurement of the electric dipole moment of H or HE may well come prior to the coveted measurement of the neutron EDM. Exact model calculations for the deuteron are feasible, and we explore here the model dependence of such deuteron EDM calculations.
An upper limit to the electric dipole moment of the neutron from lattice QCD
B. Alles; M. D'Elia; A. Di Giacomo
2005-10-11
A linear increase with the volume of the topological susceptibility can signal spontaneous breaking of parity and time inversion, due to a nonzero vacuum expectation value of the topological charge. Such a breaking would produce a nonzero electric dipole moment of the neutron, d_n. An upper limit to d_n is derived from numerical simulations at increasing volumes.
When electric charge becomes also magnetic
Tiago C. Adorno; Dmitry M. Gitman; Anatoly E. Shabad
2015-07-08
In nonlinear electrodynamics, QED included, we find a static solution to the field equations with an electric charge as its source, which is comprised of homogeneous parallel magnetic and electric fields, and a radial spherically-nonsymmetric long-range magnetic field, whose magnetic charge is proportional to the electric charge and also depends on the homogeneous component of the solution.
NASA Astrophysics Data System (ADS)
Li, Dongfang; Jiang, Mingming; Cueff, Sébastien; Dodson, Christopher M.; Karaveli, Sinan; Zia, Rashid
2014-04-01
We experimentally quantify the contribution of magnetic dipole (MD) transitions to the near-infrared light emission from trivalent erbium-doped yttrium oxide (Er3+:Y2O3). Using energy-momentum spectroscopy, we demonstrate that the 4I13/2?4I15/2 emission near 1.5 ?m originates from nearly equal contributions of electric dipole (ED) and MD transitions that exhibit distinct emission spectra. We then show how these distinct spectra, together with the differing local density of optical states for ED and MD transitions, can be leveraged to control Er3+ emission in structured environments. We demonstrate that far-field emission spectra can be tuned to resemble almost pure emission from either ED or MD transitions and show that the observed spectral modifications can be accurately predicted from the measured ED and MD intrinsic emission rates.
2D Magnetic Design and Optimization of a 88-mm Aperture 15 T Dipole for NED
Nikolai Schwerg; Christine Vollinger; Arnaud Devred; Daniel Leroy
2007-01-01
The Next European Dipole (NED) activity supported by the European Union aims at the development of a high-performance Nb3Sn conductor (Jc = 1500 A\\/mm2 @ 15 T, 4.2 K) in collaboration with European industry and at the design of a high- field dipole magnet making use of this conductor. In the framework of the NED collaboration which coordinates the activity
F. Toral; Arnaud Devred; H. Felice; Paolo Fessia; P W Loveridge; Federico Regis; J. Rochford; S. Sanz; Nikolai Schwerg; P. Vedrine; C. Vollinger
2007-01-01
The next European dipole (NED) activity is developing a high-performance Nb3Sn wire (aiming at a non-copper critical current density of 1500 A\\/mm2 at 4.2 K and 15 T), within the framework of the Coordinated Accelerator Research in Europe (CARE) project. This activity is expected to lead to the fabrication of a large aperture, high field dipole magnet. In preparation for
The permanent electric dipole moment of chromium monodeuteride, CrD
Jinhai Chen; Timothy C. Steimle; Anthony J. Merer
2007-01-01
A number of low-N lines of the X 6Sigma+<--A 6Sigma+(0,0) band of chromium monodeuteride, CrD, have been recorded at near the natural linewidth limit by high resolution laser excitation spectroscopy of a supersonic molecular beam sample. The shifts and splitting of these lines caused by a static electric field have been analyzed to give the permanent electric dipole moments of
The permanent electric dipole moment of chromium monodeuteride, CrD
Jinhai Chen; Timothy C. Steimle; Anthony J. Merer
2007-01-01
A number of low-N lines of the X 6?+?A 6?+(0,0) band of chromium monodeuteride, CrD, have been recorded at near the natural linewidth limit by high resolution laser excitation spectroscopy of a supersonic molecular beam sample. The shifts and splitting of these lines caused by a static electric field have been analyzed to give the permanent electric dipole moments of
Paddlefish strike at artificial dipoles simulating the weak electric fields of planktonic prey.
Wojtenek, W; Pei, X; Wilkens, L A
2001-04-01
The freshwater paddlefish Polyodon spathula (Polyodontidae) feeds primarily on the water flea (Daphnia sp.), and previous studies suggest that these fish detect their planktonic prey using their rostral electrosensory system. Zooplankton produce direct-current and oscillating alternating-current electric fields containing multiple frequencies and amplitudes. We asked whether an inanimate electric field is sufficient to elicit paddlefish strikes equivalent to their feeding behavior. Juvenile paddlefish respond to artificial dipole stimuli by investigating the electric field and striking at the dipole electrode tips. These behavioral responses, scored as strikes, exhibit a bandpass characteristic with a maximum response between 5 and 15 Hz. Responses were less frequent at higher (20, 30, 40, 50 Hz) and lower (0.1, 0.5, 1 Hz) test frequencies, with a steep drop-off below 5 Hz. Strike rates also varied with stimulus intensity. Response frequency was greatest at 0.25 microA peak-to-peak amplitude, with reduced responses at lower and higher amplitudes (0.125 and 1.25 microA). Striking behavior was also influenced by water conductivity: strike rate was reduced at higher water conductivity. Dipole-elicited strikes exhibit behavioral plasticity. Fish habituate to repetitive dipole stimuli that are not reinforced by prey capture, and they dishabituate after food reinforcement. These experiments characterize paddlefish feeding strikes towards dipole electrodes at signal frequencies and intensities simulating the electric fields of zooplankton, their natural prey, and demonstrate that electric fields are sufficient to elicit feeding behavior. The results support the conclusion that paddlefish use their passive electrosensory system for planktivorous feeding. PMID:11273801
Magnetic levitation for effective loading of cold cesium atoms in a crossed dipole trap
NASA Astrophysics Data System (ADS)
Li, Yuqing; Feng, Guosheng; Xu, Rundong; Wang, Xiaofeng; Wu, Jizhou; Chen, Gang; Dai, Xingcan; Ma, Jie; Xiao, Liantuan; Jia, Suotang
2015-05-01
We report a detailed study of effective magnetically levitated loading of cold atoms in a crossed dipole trap: an appropriate magnetic field gradient precisely compensates for the destructive gravitational force of the atoms and an additional bias field simultaneously eliminates the antitrapping potential induced by the magnetic field gradient. The magnetic levitation is required for a large-volume crossed dipole trap to form a shallow but very effective loading potential, making it a promising method for loading and trapping more cold atoms. For cold cesium atoms in the F =3 , m F =3 state prepared by three-dimensional degenerated Raman sideband cooling, a large number of atoms ˜3.2 ×106 have been loaded into a large-volume crossed dipole trap with the help of the magnetic levitation technique. The dependence of the number of atoms loaded and trapped in the dipole trap on the magnetic field gradient and bias field, respectively, is in good agreement with the theoretical analysis. The optimum magnetic field gradient of 31.13 G/cm matches the theoretical value of 31.3 G/cm well. This method can be used to obtain more cold atoms or a large number of Bose-Einstein condensation atoms for many atomic species in high-field seeking states.
P. G. Judge
2007-01-01
Stokes profiles of typical magnetic dipole coronal emission lines contain information on the embedded magnetic fields, but the interpretation of the lines is subject to ambiguities. The present study illuminates the information content of coronal emission line measurements that include all four Stokes parameters. The simplest case of localized emission along the line of sight, such as that from a
Tichit, Paul-Henri; Burokur, Shah Nawaz; Qiu, Cheng-Wei; de Lustrac, André
2013-09-27
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
Molecular Expressions: Electricity & Magnetism: Resistance
NSDL National Science Digital Library
Michael Davidson
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..
Simple model of skeletal matter composed of magnetized electrically conducting thin rods
A. B. Kukushkin; K. V. Cherepanov
2005-01-01
A simple electrodynamic model for describing the behavior of a skeletal matter composed of magnetized, electrically conducting thin rods (1D magnetic dipoles) is proposed. It is aimed at modeling the self-assembling of a skeletal matter from carbon nanotubes (or similar nanodust), as suggested for interpreting the experimental data on the long-lived filamentary structures in the high-current electric discharges. Here the
Hindered magnetic dipole transition in the covariant light-front approach
Wei Wang
2010-02-18
Hindered magnetic dipole transitions $\\Upsilon(nS)\\to \\gamma \\eta_b(n'S)$ are studied in the covariant light-front approach. Compared with the allowed magnetic dipole transitions, we find that results for hindered magnetic dipole transitions are sensitive to heavy quark mass and shape parameters of the light-front wave functions. It is possible to tune the parameters so that the predictions of branching fractions of $\\Upsilon(2S,3S)\\to\\gamma\\eta_b$ are consistent with the recent experimental data, but the relevant decay constant of $\\eta_b$ is much smaller than that of $\\Upsilon(1S)$. We also generalize the investigation to the charmonium sector and find the the same conclusion.
HD1: Design and Fabrication of a 16 Tesla Nb3Sn Dipole Magnet
A. R. Hafalia; S. E. Barlett; S. Caspi; L. Chiesa; D. R. Dietderich; P. Ferracin; M. Goli; S. A. Gourlay; C. R. Hannaford; H. Higley; A. F. Lietzke; N. Liggins; S. Mattafirri; A. D. McInturff; M. Myman; G. L. Sabbi; R. M. Scanlan; J. Swanson
2003-01-01
The Lawrence Berkeley National Laboratory (LBNL) Supcrconducting Magnet Group has completed the design, fabrication and tcst of HD1, a 16 T block-coil dipole magnet. State of the art NbSn conductor was wound in double-layer racetrack coils and supported by an iron yoke and a tensioned aluminum shell. In order to prevent conductor movement under magnetic forces up to the design
HD1: Design and Fabrication of a 16 Tesla Nb3Sn DipoleMagnet
A. R. Hafalia; S. E. Bartlett; S. Capsi; L. Chiesa; D. R. Dietderich; P. Ferracin; M. Goli; S. A. Gourlay; C. R. Hannaford; H. Highley; A. F. Lietzke; N. Liggins; S. Mattafirri; A. D. McInturff; M. Nyman; G. L. Sabbi; R. M. Scanlan; J. Swanson
2003-01-01
The Lawrence Berkeley National Laboratory (LBNL) Superconducting Magnet Group has completed the design, fabrication and test of HD1, a 16 T block-coil dipole magnet. State of the art NbâSn conductor was wound in double-layer racetrack coils and supported by an iron yoke and a tensioned aluminum shell. In order to prevent conductor movement under magnetic forces up to the design
Design and Test of a Nb3Sn Subscale Dipole Magnet for Training Studies
Helene Felice; Shlomo Caspi; Daniel R. Dietderich; Paolo Ferracin; Steve A. Gourlay; Aurelio R. Hafalia; Alan F. Lietzke; Alain Mailfert; Gianluca Sabbi; Pierre Vedrine
2007-01-01
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 Nb3Sn racetrack coils. Whereas the original LBNL subscale magnet was in a dual
Mechanical analysis of the Nb3Sn dipole magnet HD1
Paolo Ferracin; Scott E. Bartlett; Shlomo Caspi; Daniel R. Dietderich; Steve A. Gourlay; Charles R. Hannaford; Aurelio R. Hafalia; Alan F. Lietzke; Sara Mattafirri; Gianluca Sabbi
2005-01-01
The Superconducting Magnet Group at Lawrence Berkeley National Laboratory (LBNL) has recently fabricated and tested HD1, a Nb3Sn dipole magnet. The magnet reached a 16 T field, and exhibited training quenches in the end regions and in the straight section. After the test, HD1 was disassembled and inspected, and a detailed 3D finite element mechanical analysis was done to investigate
Recent Test Results of the High Field Dipole Magnet HD2
P. Ferracin; B. Bingham; S. Caspi; D. W. Cheng; D. R. Dietderich; H. Felice; A. R. Hafalia; C. R. Hannaford; J. Joseph; A. F. Lietzke; J. Lizarazo; G. Sabbi; X. Wang
2010-01-01
The 1 m long Nb3Sn dipole magnet HD2, fabricated and tested at Lawrence Berkeley National Laboratory, represents a step towards the development of block-type accelerator quality magnets operating in the range of 13-15 T. The magnet design features two coil modules composed of two layers wound around a titanium-alloy pole. The layer 1 pole includes a round cutout to provide
Sensitivity of Field Harmonics in Nb3Sn Dipole Magnet to the Correction Strip Position
V. V. Kashikhin; A. V. Zlobin
The method of correction of the coil magnetization effect in Nb3Sn dipole magnet using thin iron strips has been proposed in TD099-048. This note presents the results of calculation of field harmonics sensitivity to the correction strip geometry and position variations in magnet bore. A possibility of reduction of strip alignment errors on the field quality is also discussed. I.
Test results for HD1, a 16 tesla Nb3Sn dipole magnet
A. F. Lietzke; S. Bartlett; P. Bish; S. Caspi; L. Chiesa; D. Dietderich; P. Ferracin; S. A. Gourlay; M. Goli; R. R. Hafalia; H. Higley; R. Hannaford; W. Lau; N. Liggens; S. Mattafirri; A. McInturff; M. Nyman; G. Sabbi; R. Scanlan; J. Swanson
2004-01-01
The Superconducting Magnet Group at Lawrence Berkeley National Laboratory has been developing the technology for using brittle superconductor in high-field accelerator magnets. HD1, the latest in a series of magnets, contains two, double-layer Nb3Sn flat racetrack coils. This single-bore dipole configuration, using the highest performance conductor available, was designed and assembled for a 16 tesla conductor\\/structure\\/pre-stress proof-of-principle. With the combination
HD1: design and fabrication of a 16 Tesla Nb3Sn dipole magnet
A. R. Hafalia; S. E. Bartlett; S. Caspi; L. Chiesa; D. R. Dietderich; P. Ferracin; M. Goli; S. A. Gourlay; C. R. Hannaford; H. Higley; A. F. Lietzke; N. Liggins; S. Mattafirri; A. D. McInturff; M. Nyman; G. L. Sabbi; R. M. Scanlan; J. Swanson
2004-01-01
The Lawrence Berkeley National Laboratory (LBNL) Superconducting Magnet Group has completed the design, fabrication and test of HD1, a 16 T block-coil dipole magnet. State of the art Nb3Sn conductor was wound in double-layer racetrack coils and supported by an iron yoke and a tensioned aluminum shell. In order to prevent conductor movement under magnetic forces up to the design
Volume 182, number I CHEMICAL PHYSICS LETTERS 19July 1991 The electric dipole moments of SeH and GeH
Ashworth, Stephen H.
Volume 182, number I CHEMICAL PHYSICS LETTERS 19July 1991 The electric dipole moments of SeH and Ge in this case, the measurements can be used to determine the molecule's electric dipole moment. The permanent electric dipole moment of SeH has been measured previously from the Stark effect (h=O.483 D). It is found
Calculation of the (T,P)-odd electric dipole moment of thallium and cesium
Dzuba, V. A.; Flambaum, V. V. [School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia)
2009-12-15
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.
Radiation effects in a muon collider ring and dipole magnet protection
Mokhov, N.V.; Kashikhin, V.V.; Novitski, I.; Zlobin, A.V.; /Fermilab
2011-03-01
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.
Calculated electric dipole moment of NiH X2Delta
NASA Technical Reports Server (NTRS)
Walch, S.; Bauschlicher, C. W., Jr.; Langhoff, S. R.
1985-01-01
A calculated dipole moment of 2.39 D at R sub e = 2.79 a sub 0 is reported, obtained from complete active space SCF/configuration interaction calculations plus one natural orbital iteration. The calculation is in good agreement with the experimental value of 2.4 + or - 0.1 D measured for the lowest vibrational level. In agreement with Gray et al. (1985), it is found that the dipole moment is strongly correlated with the 3d electron population; the good agreement with experiment thus provides verification of the mixed state model of NiH. It is concluded that the electric dipole moment of NiH is a sensitive test of the quality of the NiH wave function.
Modification of cos ? coil shape in superconducting dipole magnets for reducing the coil size
NASA Astrophysics Data System (ADS)
Sarma, P. R.; Ibomcha, N.; Bhandari, R. K.
2005-01-01
In coil-dominated superconducting dipole magnets the coil size and hence the cost of the magnet can be reduced by optimizing the shape of the coil. We have used the variational calculus and a random search technique to show that the coil shape markedly deviates from the conventional cos? design when one reduces the coil size while holding the field and field quality to specified values. A block-coil dipole giving a field of 7.0T has been designed on the basis of the optimization. With iron yoke this can give a field of 8.4T.
Kim, Young Jin
2012-01-01
A discovery of a permanent electric dipole moment (EDM) of the neutron would provide one of the most important low energy tests of the discrete symmetries beyond the Standard Model of particle physics. A new search of neutron EDM, to be conducted at the spallation neutron source (SNS) at ORNL, is designed to improve the present experimental limit of ~10^-26 e-cm by two orders of magnitude. The experiment is based on the magnetic-resonance technique in which polarized neutrons precess at the Larmor frequency when placed in a static magnetic field; a non-zero EDM would be evident as a difference in precession frequency when a strong external electric field is applied parallel vs. anti-parallel to the magnetic field. In addition to its role as neutron spin-analyzer via the spin-dependent n+3He nuclear capture reaction, polarized helium-3 (which has negligible EDM) will serve as co-magnetometer to correct for drifts in the magnetic field. In one of the two methods that will be built into the apparatus, the helium...
NASA Astrophysics Data System (ADS)
Wang, J. G.
2006-01-01
We have performed 3D computing simulations to study the magnetic field distribution of the injection chicane dipoles in the SNS accumulator ring. The simulations yield the performance characteristics of the magnets and generate the magnetic field data in three dimensional grids for further beam tracking study. Based on the simulation data, a 3D multipole expansion of the chicane dipole field, consisting of the generalized gradients and their derivatives, has been made. The harmonic and pseudoharmonic components in the expansion give much insight into the magnet physics and can fit directly into theoretical frame work of beam optics. The expansion is quasianalytical by fitting numeric data into interpolation functions. A 5th-order representation of the magnetic field is generated, and the effects of even higher-order terms on the field representation are discussed.
Induced Magnetic Dipole at Callisto: 3-D Hybrid Modeling of Flybys by Galileo
NASA Astrophysics Data System (ADS)
Holmstrom, M.; Lindkvist, J.; Khurana, K. K.; Fatemi, S.; Barabash, S.
2014-12-01
Modeling the interaction between Callisto and Jupiter's magnetosphere is important to understand the origin of the magnetic field perturbations observed by Galileo, potentially related to subsurface oceans. By using a 3-D hybrid plasma solver, we have varied the induced magnetic dipole responses due to the time-varying magnetic field of the Jovian magnetosphere corresponding to the C3 and C9 flybys by Galileo. The internal conductivity of Callisto has been set to match the induced dipole response. The model is thus including the physics of a time-varying magnetic field and the dynamics of the magnetospheric plasma. We see that the magnetic response by Callisto depends strongly on the magnetospheric plasma environment.
Fabrication and Test Results of a Nb3Sn Superconducting Racetrack Dipole Magnet
Chow, K.; Dietderich, D.R.; Gourlay, S.A.; Gupta, R.; Harnden, W.; Lietzke, A. F.; McInturff, A.D.; Millos, G.A.; Morrison, L.; Morrison, M.; Scanlan, R.M.
2000-02-06
A 'proof-of-principle' Nb{sub 3}Sn superconducting dual-bore dipole magnet was built from racetrack coils, as a first step in a program to develop an economical, 15 Tesla, accelerator-quality magnet. The mechanical design and magnet fabrication procedures are discussed. No training was required to achieve temperature-dependent plateau currents, despite several thermal cycles that involved partial magnet disassembly and substantial pre-load variations. Subsequent magnets are expected to approach 15 Tesla with substantially improved conductor.
Fabrication and Test Results of a Nb3Sn Superconducting Racetrack Dipole Magnet
Chow, K.; Dietderich, D.R.; Gourlay, S.A.; Gupta, R.; Harnden, W.; Lietzke, A.F.; McInturff, A.D.; Millos, G.A.; Morrison, L.; Morrison, M.; Scanlan, R.M.
1999-03-22
A 'proof-of-principle' Nb{sub 3}Sn superconducting dual-bore dipole magnet was built from racetrack coils, as a first step in a program to develop an economical, 15 Tesla, accelerator-quality magnet. The mechanical design and magnet fabrication procedures are discussed. No training was required to achieve temperature-dependent plateau currents, despite several thermal cycles that involved partial magnet disassembly and substantial pre-load variations. Subsequent magnets are expected to approach 15 Tesla with substantially improved conductor.
Observation of electric-dipole-forbidden infrared transitions in cold molecular ions
NASA Astrophysics Data System (ADS)
Germann, Matthias; Tong, Xin; Willitsch, Stefan
2014-11-01
Spectroscopic transitions in atoms and molecules that are not allowed within the electric-dipole approximation, but occur because of higher-order terms in the interaction between matter and radiation, are termed dipole-forbidden. These transitions are extremely weak and therefore exhibit very small natural linewidths. Dipole-forbidden optical transitions in atoms form the basis of next-generation atomic clocks and of high-fidelity qubits used in quantum information processors and quantum simulators. In molecules, however, such transitions are much less characterized, reflecting the considerable challenges to address them. Here, we report direct observation of dipole-forbidden, electric-quadrupole-allowed infrared (IR) transitions in a molecular ion. Their detection was enabled by the very long interrogation times of several minutes afforded by the sympathetic cooling of individual quantum-state-selected molecular ions into the nearly perturbation-free environment of a Coulomb crystal. The present work paves the way for new mid-IR frequency standards and precision spectroscopic measurements on single molecules in the IR domain.
NASA Astrophysics Data System (ADS)
Guella, Thomas Paul
1985-12-01
An electric field deflection technique has been used to obtain the average dimer polarizabilities of all the alkali halides, and the scalar ('2)P(, 1/2) polarizabilities of indium and thallium. The experimental procedure consisted of passing a well collimated effusive beam through a region of inhomogeneous electric field and analyzing the deflected beam pattern, with respect to the undeflected beam shape, at the detector. The beam deflections were analyzed in two ways. One method consisted of normalizing the deflections by comparing the experi- mental deflections to those obtained from atomic lithium, whose polarizability is known to within 2%. The normalization reduces the polarizability determination to the ratio of measured line slopes. This procedure lessens systematic errors resulting from a lack of detailed information concerning field variations along the beam path within the interaction region. A second method, employing a C.D.C. Cyber 360 computer, comprizes a quantitative analysis of the monomer and dimer deflections in which part of the actual deflected beam shape is used. Our results are compared with the polarizability values obtained from a simple 'mass-spring' model for the dimer which employs calculated (and experimental) vibrational frequencies and effective ionic polarizabilities from various dimer models. In addition to an electric deflection measurement, and E-H gradient balance technique was also employed for the indium and thallium ('2)P(, 1/2) measurements. This method consisted of balancing the magnetic dipole force for negative magnetic substates against the induced electric dipole force in a region where simultaneous and congruent inhomogeneous electric and magnetic fields are estab- lished. These measurements were normalized to an m = -3 substate of Cs whose polarizability is known to within (.5%). The results of our electric deflection and E-H gradient balance measurements for these atomic systems were (UNFORMATTED TABLE FOLLOWS). In Tl. 10.18 (+OR-) 1.2 (ANGSTROM)('3)) 7.6 (+OR-) 0.8 (ANGSTROM)('3). (TABLE ENDS). These values compare extremely well with the recent calculation for Tl of Flambaum and Sushkov (7.11 (ANGSTROM)('3)) and that of Liberman and Zangwill for In (9.66 (ANGSTROM)('3)) and Tl (7.74 (ANGSTROM)('3)).
Measurements of vacuum magnetic birefringence using permanent dipole magnets: the PVLAS experiment
F. Della Valle; U. Gastaldi; G. Messineo; E. Milotti; R. Pengo; L. Piemontese; G. Ruoso; G. Zavattini
2013-01-21
The PVLAS collaboration is presently assembling a new apparatus (at the INFN section of Ferrara, Italy) to detect vacuum magnetic birefringence (VMB). VMB is related to the structure of the QED vacuum and is predicted by the Euler-Heisenberg-Weisskopf effective Lagrangian. It can be detected by measuring the ellipticity acquired by a linearly polarised light beam propagating through a strong magnetic field. Using the very same optical technique it is also possible to search for hypothetical low-mass particles interacting with two photons, such as axion-like (ALP) or millicharged particles (MCP). Here we report results of a scaled-down test setup and describe the new PVLAS apparatus. This latter one is in construction and is based on a high-sensitivity ellipsometer with a high-finesse Fabry-Perot cavity ($>4\\times 10^5$) and two 0.8 m long 2.5 T rotating permanent dipole magnets. Measurements with the test setup have improved by a factor 2 the previous upper bound on the parameter $A_e$, which determines the strength of the nonlinear terms in the QED Lagrangian: $A_e^{\\rm (PVLAS)} < 3.3 \\times 10^{-21}$ T$^{-2}$ 95% c.l. Furthermore, new laboratory limits have been put on the inverse coupling constant of ALPs to two photons and confirmation of previous limits on the fractional charge of millicharged particles is given.
Information content of the low-energy electric dipole strength: Correlation analysis
NASA Astrophysics Data System (ADS)
Reinhard, P.-G.; Nazarewicz, W.
2013-01-01
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.
Information Content of the Low-Energy Electric Dipole Strength: Correlation Analysis
Reinhard, P.-G. [Inst. fur Theoretische Physik II, Univ. Erlangen-Numberg, Germany; Nazarewicz, Witold [UTK/ORNL/University of Warsaw
2013-01-01
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.
Operator evolution for ab initio electric dipole transitions of 4He
Micah D. Schuster; Sofia Quaglioni; Calvin W. Johnson; Eric D. Jurgenson; Petr Navratil
2015-04-02
A goal of nuclear theory is to make quantitative predictions of low-energy nuclear observables starting from accurate microscopic internucleon forces. A major element of such an effort is applying unitary transformations to soften the nuclear Hamiltonian and hence accelerate the convergence of ab initio calculations as a function of the model space size. The consistent simultaneous transformation of external operators, however, has been overlooked in applications of the theory, particularly for nonscalar transitions. We study the evolution of the electric dipole operator in the framework of the similarity renormalization group method and apply the renormalized matrix elements to the calculation of the 4He total photoabsorption cross section and electric dipole polarizability. All observables are calculated within the ab initio no-core shell model. We find that, although seemingly small, the effects of evolved operators on the photoabsorption cross section are comparable in magnitude to the correction produced by including the chiral three-nucleon force and cannot be neglected.
Probing CP Violation with the Electric Dipole Moment of Atomic Mercury
Latha, K. V. P.; Das, B. P. [Indian Institute of Astrophysics, Bangalore (India); Angom, D. [Physical Research Laboratory, Ahmedabad (India); Mukherjee, D. [Indian Association of Cultivation of Science, Kolkata (India)
2009-08-21
The electric dipole moment of atomic {sup 199}Hg induced by the nuclear Schiff moment and the tensor-pseudotensor electron-nucleus interactions are calculated. For this, we develop and employ a novel method based on the relativistic coupled-cluster theory. The results of our theoretical calculations, combined with the latest experimental result of the {sup 199}Hg electric dipole moment, provide new bounds on the T reversal or CP violation parameters theta{sub QCD}, the tensor-pseudotensor coupling constant C{sub T}, and (d-tilde{sub u}-d-tilde{sub d}). This is the most accurate calculation of these parameters to date. We highlight the crucial role of electron correlation effects in their interplay with the P, T violating interactions. Our results demonstrate substantial changes in the results of earlier calculations of these parameters which can be attributed to the more accurate inclusion of important correlation effects.
The electric and magnetic form factors of the proton
A1 Collaboration; J. C. Bernauer; M. O. Distler; J. Friedrich; Th. Walcher; P. Achenbach C. Ayerbe Gayoso; R. Böhm; L. Debenjak; L. Doria; A. Esser; H. Fonvieille; M. Gómez Rodrígues de la Paz; J. M. Friedrich; M. Makek; H. Merkel; D. G. Middleton; U. Müller; L. Nungesser; J. Pochodzalla; M. Potokar; S. Sánchez Majos; B. S. Schlimme; S. Širca; M. Weinriefer
2014-07-29
The paper describes a precise measurement of electron scattering off the proton at momentum transfers of $0.003 \\lesssim Q^2 \\lesssim 1$\\ GeV$^2$. The average point-to-point error of the cross sections in this experiment is $\\sim$ 0.37%. These data are used for a coherent new analysis together with all world data of unpolarized and polarized electron scattering from the very smallest to the highest momentum transfers so far measured. The extracted electric and magnetic form factors provide new insight into their exact shape, deviating from the classical dipole form, and of structure on top of this gross shape. The data reaching very low $Q^2$ values are used for a new determination of the electric and magnetic radii. An empirical determination of the Two-Photon-Exchange (TPE) correction is presented. The implications of this correction on the radii and the question of a directly visible signal of the pion cloud are addressed.
Constraints on UED KK-neutrino dark matter from magnetic dipole moments
Thomas Flacke; David W. Maybury
2006-01-24
Generically, universal extra dimension (UED) extensions of the standard model predict the stability of the lightest Kaluza-Klein (KK) particle and hence provide a dark matter candidate. For UED scenarios with one extra dimension, we model-independently determine the size of the induced dimension-five magnetic dipole moment of the KK-neutrino, $\
Charged spinning fluids with magnetic dipole moment in the Einstein-Cartan theory
Amorim, R.
1985-06-15
A classical perfect charged spinning fluid with magnetic dipole moment in the Einstein-Cartan theory is described by using an Eulerian Lagrangian formalism. The field equations and equations of motion so obtained generalize those proposed by Ray and Smalley. We also clarify some open questions which appear in the works of Ray and Smalley and of de Ritis et al.
Electromagnetic Design Study for a Large Bore 15T Superconducting Dipole Magnet
Schwerg, N; Devred, Arnaud; Henke, H
2005-01-01
In the framework of research and development (R&D) activities at CERN the Next European Dipole (NED) program is one which is to the development of a high-field dipole magnet using Nb_3Sn superconductors. Part of the NED activities is a design study of different possible dipole configurations which is shared amongst the collaborating institutes. This thesis covers the electromagnetic design study of an 88 mm large bore superconducting 15 T dipole magnet with a coil cross section in cos-theta-layer design. Based on analytically describable geometries the sources of multipole errors are studied and elementary estimations of the magnet are carried out, e.g., the required amount of superconductors or the influence of the iron yoke thickness on the field quality. The magnet cross section for NED is optimized by means of the CERN field computation program ROXIE. The preliminary NED design serves as starting point for the coil cross section optimization with respect to field quality and a radial positioning of th...
ERIC Educational Resources Information Center
Kholmetskii, Alexander L.; Yarman, T.
2010-01-01
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…
Far-region electromagnetic radiation with a vertical magnetic dipole in sea
Yunliang Long; Hongyan Jiang; Bernhard Rembold
2001-01-01
Great attention has been paid to conveniently calculating the electromagnetic (EM) field due to a vertical magnetic dipole (VMD) buried in stratified media. It is quite difficult because this topic involves the computation of Sommerfeld (1949) type integrals (SI). In this paper closed-form expressions for the far field of a VMD embedded below the sea surface are obtained easily by
Observation of the Dynamical Structure of Turbulence in Plasma Confined by a Dipole Magnetic Field
Mauel, Michael E.
Observation of the Dynamical Structure of Turbulence in Plasma Confined by a Dipole Magnetic Field in time and cause chaotic plasma fluctuations. The predominance of large scale structures represents energy cascade and a linear damping of small scale structures. PACS numbers: 52.35Mw, 52.35.Ra, 52.55.Hc
R Measurements With ISR in BaBar: Hadronic Part of Muon Magnetic Dipole Moment
Taras, P.; /Quebec U., Montreal
2007-07-09
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}.
R measurements with ISR in BaBar - hadronic part of muon magnetic dipole moment
Taras, Paul [Universite de Montreal, Physique des Particules, Montreal, Quebec, H3C 3J7 (Canada)
2007-02-27
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}.
Development of cos-theta Nb{sub 3}Sn dipole magnets for VLHC
Alexander Zlobin et al.
2001-07-20
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.
Development of cos-theta Nb3Sn dipole magnets for VLHC
Alexander Zlobin; G. Ambrosio; N. Andreev; E. Barzi; D. Chichili; V. V. Kashikhin; P. J. Limon; I. Terechkine; S. Yadav; R. Yamada
2001-01-01
This paper describes the double aperture dipole magnets developed for a VLHC based on Nb3Sn superconductor, a cos-theta coil, cold and warm iron yokes, and the wind-and-react fabrication technique. Status of the model R&D program, strand and cable and other major component development are also discussed
NASA Technical Reports Server (NTRS)
Omidvar, K.
1977-01-01
The branching ratios in hydrogen-like atoms due to the electric-dipole transitions are tabulated for the initial principal and azimuthal quantum numbers n prime l prime, and final principal and azimuthal quantum numbers n l. Average values with respect to l prime are given. The branching ratios not tabulated, including the initial states n prime yields infinity l prime corresponding to the threshold of the continuum, could be obtained by extrapolation.
Torque for electron spin induced by electron permanent electric dipole moment
Senami, Masato, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Fukuda, Masahiro, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Ogiso, Yoji, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Tachibana, Akitomo, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp [Department of Micro Engineering, Kyoto University, Kyoto 615-8540 (Japan)
2014-10-06
The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field.
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
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.
Neutron electric dipole moment and flavor changing interactions in supersymmetric theories
Gi-Chol Cho; Naoyuki Haba; Minako Honda
2005-10-04
Supersymmetric contributions to the neutron electric dipole moment (EDM) are studied taking account of the flavor changing interactions. We found that the gluino contribution is sensitive to the flavor changing interaction. Enhancement of neutron EDM via flavor mixing effects is possible when the squark mass difference between the different generations is sizable. As an example, the results of the SUSY SU(5) GUT with right-handed neutrinos are briefly discussed.
Larger Higgs-boson-exchange terms in the neutron electric dipole moment
Steven Weinberg
1989-01-01
The neutron electric dipole moment (dn) due to Higgs-boson exchange is reconsidered, now without assuming that Higgs-boson exchange is solely responsible for K0L-->2pi. The dominant contribution to dn arises from a three-gluon operator, produced in integrating out top quarks and neutral Higgs bosons. The estimated results together with current experimental bounds on dn show, even for the largest plausible Higgs-boson
Development of a multifunction module for the neutron electric dipole moment experiment at PSI
NASA Astrophysics Data System (ADS)
Bourrion, O.; Pignol, G.; Rebreyend, D.; Vescovi, C.
2013-02-01
Experiments aiming at measuring the neutron electric dipole moment (nEDM) are at the forefront of precision measurements and demand instrumentation of increasing sensitivity and reliability. In this paper, we report on the development of a dedicated acquisition and control electronics board for the nEDM experiment at the Paul Scherrer Institute (PSI) in Switzerland. This multifunction module is based on a FPGA (Field Programmable Gate Array) which allows an optimal combination of versatility and evolution capacities.
The electric dipole moment of the nucleon from simulations at imaginary vacuum angle theta
R. Horsley; T. Izubuchi; Y. Nakamura; D. Pleiter; P. E. L. Rakow; G. Schierholz; J. Zanotti
2008-08-15
We compute the electric dipole moment of proton and neutron from lattice QCD simulations with N_f=2 flavors of dynamical quarks at imaginary vacuum angle theta. The calculation proceeds via the CP odd form factor F_3. A novel feature of our calculation is that we use partially twisted boundary conditions to extract F_3 at zero momentum transfer. As a byproduct, we test the QCD vacuum at nonvanishing theta.
New constraints on Lorentz invariance violation from the neutron electric dipole moment
I. Altarev; C. A. Baker; G. Ban; K. Bodek; M. Daum; M. Fertl; B. Franke; P. Fierlinger; P. Geltenbort; K. Green; M. G. D. van der Grinten; P. G. Harris; R. Henneck; M. Horras; P. Iaydjiev; S. N. Ivanov; N. Khomutov; K. Kirch; S. Kistryn; A. Knecht; A. Kozela; F. Kuchler; B. Lauss; T. Lefort; Y. Lemière; A. Mtchedlishvili; O. Naviliat-Cuncic; J. M. Pendlebury; G. Petzoldt; E. Pierre; F. M. Piegsa; G. Pignol; G. Quéméner; D. Rebreyend; S. Roccia; P. Schmidt-Wellenburg; N. Severijns; D. Shiers; K. F. Smith; Yu. Sobolev; J. Zejma; J. Zenner; G. Zsigmond
2010-06-25
We propose an original test of Lorentz invariance in the interaction between a particle spin and an electromagnetic field and report on a first measurement using ultracold neutrons. We used a high sensitivity neutron electric dipole moment (nEDM) spectrometer and searched for a direction dependence of a nEDM signal leading to a modulation of its magnitude at periods of 12 and 24 hours. We constrain such a modulation to $d_{12} 10^{10}$~GeV.
Shell model estimate of electric dipole moment in medium and heavy nuclei
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
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.
Measurement of the Electron Electric Dipole Moment Using YbF Molecules
J. J. Hudson; B. E. Sauer; M. R. Tarbutt; E. A. Hinds
2002-01-01
The most sensitive measurements of the electron electric dipole moment d_e\\u000ahave previously been made using heavy atoms. Heavy polar molecules offer a\\u000agreater sensitivity to d_e because the interaction energy to be measured is\\u000atypically 10^3 times larger than in a heavy atom. We report the first\\u000ameasurement of this kind, for which we have used the molecule YbF.
Strait, J.; Coulter, K.; Jaffery, T.; Kerby, J.; Koska, W.; Lamm, M.J.
1990-05-03
The yoke in SSC dipole magnets provides mechanical support to the collared coil as well as serving as a magnetic element. The yoke and skin are used to increase the coil prestress and reduce collar deflections under excitation. Yokes split on the vertical or horizontal mid-plane offer different advantages in meeting these objectives. To evaluate the relative merits of the two configuration a 1.8 m model dipole was assembled and tested first with horizontally split and then with vertically split yoke laminations. The magnet was extensively instrumented to measure azimuthal and axial stresses in the coil and the cold mass skin resulting from cooldown and excitation. Mechanical behavior of this magnet with each configuration is compared with that of other long and short models and with calculations. 13 refs., 5 figs.
Caspi, S.; Gilbert, W.S.; Rechen, J.B.
1982-11-01
The quench current of a superconducting dipole magnet decreases from its slow-ramp value as the current ramp-rate is increased, due to heat buildup in the coil winding. This ramp-rate dependence has been measured for several superconducting dipoles in both normal He I and in superfluid He II. The heat generated by charging fields has been measured for severall magnets in He II, where particularly sensitive and accurate measurements can be made of any heat input to the essentially isothermal helium bath by its temperature rise. Previously measured values of heat transfer are applied to the data from one magnet to explain its observed behavior. The conclusion is drawn that at a given cycle rate, a superfluid He II-cooled superconducting accelerator can operate closer to the short-sample limit of the magnet's superconductor than can a corresponding He I-cooled machine.
NASA Astrophysics Data System (ADS)
Forster, F.; Mühlbacher, M.; Schuh, D.; Wegscheider, W.; Ludwig, S.
2015-05-01
On-chip magnets can be used to implement relatively large local magnetic field gradients in nanoelectronic circuits. Such field gradients provide possibilities for all-electrical control of electron spin qubits where important coupling constants depend crucially on the detailed field distribution. We present a double quantum dot (QD) hybrid device laterally defined in a GaAs/AlGaAs heterostructure which incorporates two single-domain nanomagnets. They have appreciably different coercive fields which allows us to realize four distinct configurations of the local inhomogeneous field distribution. We perform dc transport spectroscopy in the Pauli-spin blockade regime as well as electric-dipole-induced spin resonance (EDSR) measurements to explore our hybrid nanodevice. Characterizing the two nanomagnets we find excellent agreement with numerical simulations. By comparing the EDSR measurements with a second double QD incorporating just one nanomagnet we reveal an important advantage of having one magnet per QD: It facilitates strong field gradients in each QD and allows us to control the electron spins individually for instance in an EDSR experiment. With just one single-domain nanomagnet and common QD geometries EDSR can likely be performed only in one QD.
Electric transition dipole moment in pre-Born-Oppenheimer molecular structure theory.
Simmen, Benjamin; Mátyus, Edit; Reiher, Markus
2014-10-21
This paper presents the calculation of the electric transition dipole moment in a pre-Born-Oppenheimer framework. Electrons and nuclei are treated equally in terms of the parametrization of the non-relativistic total wave function, which is written as a linear combination of basis functions constructed from explicitly correlated Gaussian functions and the global vector representation. The integrals of the electric transition dipole moment are derived corresponding to these basis functions in both the length and the velocity representation. The calculations are performed in laboratory-fixed Cartesian coordinates without relying on coordinates which separate the center of mass from the translationally invariant degrees of freedom. The effect of the overall motion is eliminated through translationally invariant integral expressions. The electric transition dipole moment is calculated between two rovibronic levels of the H2 molecule assignable to the lowest rovibrational states of the X (1)?(g)(+) and B (1)?(u)(+) electronic states in the clamped-nuclei framework. This is the first evaluation of this quantity in a full quantum mechanical treatment without relying on the Born-Oppenheimer approximation. PMID:25338879
SUPERCONDUCTING FAST-CYCLING DIPOLE MAGNETS FOR THE GSI FUTURE ACCELERATOR FACILITY
A. Kovalenko; N. Agapov; S. Averichev; A. Doniagin; I. Eliseeva; I. Karpunina; H. Khodzhibagiyan; V. Kuzichev; G. Kuznetsov; A. Nesterov; P. Nikitaev; A. Starikov; L. Zaitsev; C. Muehle; E. Fischer; G. Hess; J. Kaugerts; M. Kauschke
The results of design and tests of 2T superconducting model dipoles, operating at 1Hz, are presented. The magnets use a SC coil made from hollow superconducting cable, cooled with forced flow two-phase helium, and utilise a two section window frame iron yoke at different temperatures: one section at 4.5 K, the other at 80 K. Measurements of magnet training, AC
Design and development of Nb3Sn single-layer common coil dipole magnet for VLHC
Giorgio Ambrosio; N. Andreev; E. Barzi; P. Bauer; D. Chichili; K. Ewald; S. Feher; L. Imbasciati; V. V. Kashikhin; S. W. Kim; P. Limon; I. Novitski; J. M. Rey; S. Yadav; R. Yamada; A. V. Zlobin; R. Scanlan
2001-01-01
Common coil dipole magnets based on Nb3Sn conductor and the react-and-wind technology are a promising option for the next generation of hadron colliders. The react-and-wind technology has potential cost benefits related to less expensive cable insulation, structural materials and magnet fabrication. A common coil design allows the use of a pre-reacted Nb3Sn superconductor with low critical current degradation after bending.
Test Results for RD3c, A Nb3Sn Common-Coil Racetrack Dipole Magnet
A. F. Lietzke; S. Caspi; M. Coccoli; D. R. Dietderich; P. Ferracin; S. A. Gourlay; R. R. Haffalia; L. Chiesa; A. D. McInturff; G. Sabbi; R. M. Scanlan
2002-01-01
The Superconducting Magnet Group at Lawrence Berkeley Laboratory has been developing racetrack technology for economical, high-field accelerator magnets from brittle superconductor. Recent tests have demonstrated (1) robust, reusable, double-layer, flat racetrack, wind and react NbSn coils, (2) a reusable, easily assembled, coil-support structure that can minimize conductor movement, and (3) 15T dipole fields, with no degradation. RD3c is our first
Test results of RD3c, a Nb3Sn common-coil racetrack dipole magnet
A. F. Lietzke; S. Caspi; L. Chiesa; M. Coccoli; D. R. Dietderich; P. Ferracin; S. A. Gourlay; R. R. Hafalia; A. D. McInturff; G. Sabbi; R. M. Scanlan
2003-01-01
The superconducting magnet group at Lawrence Berkeley National Laboratory has been developing racetrack coil technology for economical, high-field accelerator magnets from brittle superconductor. Recent tests have demonstrated 1) robust, reusable, double-layer, flat racetrack, wind and react Nb3Sn coils, 2) a reusable, easily assembled coil-support structure that can minimize conductor movement and 3) nearly 15 T dipole fields, without conductor degradation.
Quench problems of Nb3Sn cosine theta high field dipole model magnets
Ryuji Yamada; Masayoshi Wake
2005-01-01
We have developed and tested several cosine theta high field dipole model magnets for accelerator application, utilizing Nb3Sn strands made by MJR method and PIT method. With Rutherford cables made with PIT strand we achieved 10.1 Tesla central field at 2.2 K operation, and 9.5 Tesla at 4.5 K operation. The magnet wound with the MJR cable prematurely quenched at
Development of an experimental 10 T Nb3Sn dipole magnet for the CERN LHC
H. H. J. ten Kate; A. den Ouden; D. ter Avest; S. Wessel; R. Dubbeldam; W. van Emden; C. Daum; M. Bona; R. Perin
1991-01-01
An experimental 1-m long twill aperture dipole magnet developed using a high-current Nb3Sn conductor in order to attain a magnetic field well beyond 10 T at 4.2 K is described. The emphasis in this Nb3Sn project is on the highest possible field within the known Large Hadron Collider (LHC) twin-aperture configuration. A design target of 11.5 T was chosen
Observation of coupled magnetic and electric domains
M. Fiebig; Th. Lottermoser; D. Fröhlich; A. V. Goltsev; R. V. Pisarev
2002-01-01
Ferroelectromagnets are an interesting group of compounds that complement purely (anti-)ferroelectric or (anti-)ferromagnetic materials-they display simultaneous electric and magnetic order. With this coexistence they supplement materials in which magnetization can be induced by an electric field and electrical polarization by a magnetic field, a property which is termed the magnetoelectric effect. Aside from its fundamental importance, the mutual control of
Structural performance of the first SSC (Superconducting Super Collider) Design B dipole magnet
Nicol, T.H.
1989-09-01
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.
Magnetic field angle changes during manufacture and testing of SSC collider dipoles
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
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.
Study on Ampere-Turns of superconducting dipole and quadrupole magnets based on sector coils
NASA Astrophysics Data System (ADS)
Zhu, Yingshun; Wu, Yingzhi; Kang, Wen; Yang, Mei
2014-03-01
General expressions of Ampere-Turns for superconducting dipole and quadrupole magnets based on sector coils are proposed. According to the magnetic field generated by simplified coil layouts using the line current theory, the required excitation current to achieve the desired field strength in the aperture is calculated. The contribution of magnetic field by an iron yoke is taken into account by using the image current method. The validity of derived equations is confirmed by applications to main superconducting magnets which have been built in several high energy accelerators. The proposed analytical expressions provide a simple relationship among the bore field, main dimensions of the magnet, and the total excitation current. These expressions are complementary to the existing method in the electromagnetic design, and are shown to be quite similar to those of conventional magnets. Finally, the comparison of Ampere-Turns between superconducting magnets and conventional magnets is presented.
Center for Gravity, Electrical & Magnetic Studies
Center for Gravity, Electrical & Magnetic Studies Colorado School of Mines CGEMGravity&MagneticsResearchConsortium BININV3D v.2.1 A Program for the Inversion of Gravity Over 3D Structures Using a Binary Formulation for the sponsors of the Gravity & Magnetics Research Consortium © Gravity and Magnetics Research Consortium, 2009
Interaction between Plasma and a Two-Dimensional Magnetic Dipole
W. H. Bostick; H. Byfield; Y. Nakagawa; D. Wells
1962-01-01
Theory predicts that when a stream of perfectly conducting fluid ; impinges on a magnetic field, there may be a hydromagnetic interaction strong ; enough to compress the magnetic field, which leads to the formation of a boundary ; surface between the fluid and the field. The formation of a cavity in a copper ; plasma streaming around a twodimensional
The permanent electric dipole moments of iron monocarbide, FeC
Timothy C. Steimle; Wilton L. Virgo; David A. Hostutler
2002-01-01
Numerous branch features in the (0,0) [12.0] ?=2?X 3?3 and (0,0) [13.1] 3&Fgr;4?X 3?3 band systems of the iron monocarbide, FeC, have been studied using optical Stark spectroscopy. The electric field induced splittings in the high resolution laser induced fluorescence spectra were analyzed to produce values for the permanent electric dipole moments, ?, of 4.02(6) D, 4.44(6) D, and 2.36(3)
The permanent electric dipole moments of iron monocarbide, FeC
Timothy C. Steimle; Wilton L. Virgo; David A. Hostutler
2002-01-01
Numerous branch features in the (0,0) 12.0 Omega=2[left arrow]X 3Delta3 and (0,0) 13.1 3Phi4[left arrow]X 3Delta3 band systems of the iron monocarbide, FeC, have been studied using optical Stark spectroscopy. The electric field induced splittings in the high resolution laser induced fluorescence spectra were analyzed to produce values for the permanent electric dipole moments, mu, of 4.02(6) D, 4.44(6) D,
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
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.
Preliminary analysis of coil wedge dimensional variation in SSC Prototype Dipole Magnets
Pollock, D.; Brown, G.; Dwyer, S.; Gattu, R.; Warner, D.
1993-05-01
The wedges used in SSC Prototype Dipole Magnets determine the relative position of conductor blocks within magnet coils. They serve to compensate partially for the less than full keystoning of the superconductor cable and to adjust current distribution with azimuth to determine the magnetic field shape. The ability to control the size and uniformity of wedges therefore is an important factor influencing magnet quality. This paper presents preliminary results of a Statistical Quality Control study of wedge dimensional variation and predicted field quality. Dimensions of samples from outer wedges for magnet DCA102 have been measured using a programmable optical comparator. The data is used to evaluate wedge manufacturing process capability, wedge uniformity, and to predict changes in conductor block position due to wedge deviation. Expected multipole variation attributable to observed wedge variation is discussed. This work focuses on a Prototype Dipole Magnet being built at the SSCL Magnet Development Laboratory (SSCL MDL) in Waxahachie, Texas. The magnet is of the same design as the DCA3xx series magnets built at Fermi National Accelerator Laboratory (FNAL) in 1991--92 and later used in the 1992 Accelerator Systems String Test (ASST).
Design of Racetrack Coils for High Field Dipole Magnets
Sabbi, G.; Caspi, S.; Gourlay, S.A.; Hafalia, R.; Jackson, A.; Lietzke, A.; McInturff, A.D.; Scanlan, R.M.
2000-09-08
The magnet group at LBNL is currently in the process of developing high-field accelerator magnets for use in future colliders. One of the primary challenges is to provide a design which is cost-effective and simple to manufacture, at the same time resulting in good training performance and field quality adequate for accelerator operation. Recent studies have focused on a racetrack geometry that has the virtues of simplicity and conductor compatibility. The results have been applied to the design of a series of prototype high-field magnets based on Nb{sub 3}Sn conductor.
Design and optimization of the 12.5 T EFDA dipole magnet
NASA Astrophysics Data System (ADS)
Portone, A.; Salpietro, E.; Bottura, L.; Bruzzone, P.; Della Corte, A.; Fietz, W.; Heller, R.; Raff, S.; Lucas, J.; Toral, F.; Rifflet, J. M.; Testoni, P.
2006-07-01
The aim of this paper is to provide an overview of a recent study carried out—within the framework of the European Fusion Program—to design a 12.5 T superconducting dipole. By focusing on the CICC based design option, the overall design procedure is presented. In particular, the 2D optimization of the dipole cross section is described including the magneto-static analysis of the winding and iron yoke, the mechanical analysis of the conductor jacket, insulation and outer cylinder, the conductor hot spot analysis, etc. As far as the thermo-hydraulic design is concerned, simulations of nominal as well as offset operating conditions (e.g., magnet quench) are presented with emphasis on their role played in the overall magnet design. For example, diagrams reporting the helium heat removal capabilities, pressure drop, mass flow, etc. are shown and their usefulness as guidance for the magnet designer described.
Studies of time dependence of fields in TEVATRON superconducting dipole magnets
Hanft, R.W.; Brown, B.C.; Herrup, D.A.; Lamm, M.J.; McInturff, A.D.; Syphers, M.J.
1988-08-22
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.
3D Design, Contruction, and Field Analysis of CIS Main Dipole Magnets
NASA Astrophysics Data System (ADS)
Berg, G. P. A.; Fox, W.; Friesel, D. L.; Rinckel, T.
1997-05-01
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.
Bingham, Richard J; Olmsted, Peter D; Smye, Stephen W
2010-05-01
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. PMID:20866263
Search for a Permanent Electric Dipole Moment of the Mercury Atom
Fortson, E. N. [Department of Physics, University of Washington, Seattle, WA 98195 (United States)
2009-12-17
There has been exciting progress in recent years in the search for a permanent electric dipole moment (EDM) of an atom, a molecule, or the neutron. An EDM along the axis of spin can exist only if time reversal symmetry (T) is violated. Although such a dipole has not yet been detected, mainstream theories of possible new physics, such as Supersymmetry, predict the existence of EDMs within reach of modern experiments. Here I discuss the results of our new experimental search for a permanent electric dipole moment of {sup 199}Hg utilizing a stack of four vapor cells. We find d({sup 199}Hg) (0.49{+-}1.29{sub stat}{+-}0.76{sub syst})x10{sup -29} e cm, and interpret this as a new upper bound, d({sup 199}Hg)<3.1x10{sup -29} e cm(95% C.L.). This result improves our previous {sup 199}Hg limit by a factor of 7, and can be used to set new constraints on CP violation in physics beyond the Standard Model.
Experiments of Search for Neutron Electric Dipole Moment and Spin-Dependent Short-Range Force
NASA Astrophysics Data System (ADS)
Zheng, Wangzhi
It is of great importance to identify new sources of discrete symmetry violations because it can explain the baryon number asymmetry of our universe and also test the validity of various models beyond the standard model. Neutron Electric Dipole Moment (nEDM) and short-range force are such candidates for the new sources of P&T violations. A new generation nEDM experiment was proposed in USA in 2002, aiming at improving the current nEDM upperlimit by two orders of magnitude. Polarized 3He is crucial in this experiment and Duke is responsible for the 3He injection, measurements of 3He nuclear magnetic resonance (NMR) signal and some physics properties related to polarized 3He. A Monte-Carlo simulation is used to simulate the entire 3He injection process in order to study whether polarized 3He can be successfully delivered to the measurement cell. Our simulation result shows that it is achievable to maintain more than 95% polarization after 3He atoms travel through very complicated paths in the presence of non-uniform magnetic fiels. We also built an apparatus to demonstrate that the 3He precession signal can be measured under the nEDM experimental conditions using the Superconducting Quantum Interference Device (SQUID). Based on the measurement result in our lab, we project that the signal-to-noise ratio in the nEDM experiment will be at least 10. During this SQUID test, two interesting phenomena were discovered. One is the pressure dependence of the T1 of the polarized 3He which has never been reported before. The other is the discrepancy between the theoretically predicted T2 and the experimentally measured T2 of the 3He precession signal. To investigate these two interesting phenomena, two dedicated experiments were built, and two papers have been published in Physical Review A. In addition to the nEDM experiment, polarized 3He is also used in the search for the exotic short-range force. The high pressure 3He cell used in this experiment has a very thin window (˜250 mum) to maximize the effect from the force. We demonstrate that our new method could improve the current best experimental limit by two orders of magnitude. A rapid communication demonstrating the technique and the result was published in Physical Review D.
Dipole moments and near field potentials
R. E. Kleinman
1973-01-01
Expressions are derived for the moments of electric and magnetic dipoles whose far field is equivalent to the Rayleigh term in the far field of a given radiating electromagnetic field. The equivalent dipole moments are expressed as integrals over an arbitrary closed surface of the near electromagnetic fields and simplification is achieved by rewriting these expressions in terms of the
ECE 390 Electric & Magnetic Fields Catalog Description: Static and quasi-static electric and magnetic fields. Credits: 4 Terms Offered: Fall Prerequisites: MTH 255, ENGR 203 (concurrent enrollment fields in free space, Ampere's circuital law, vector magnetic potential · Biot-Savart law, magnetic
Preliminary results from a study of collar lamination variation in SSC Prototype Dipole Magnets
Gattu, R.; Brown, G.M.; Pollock, D.
1993-04-01
The collar laminations used in SSC Prototype Collider Dipole Magnets determine the volume within which the magnet coils are constrained after collaring and keying. The uniformity and symmetry of the inside volume of the collars along the length of the magnet may have a significant influence on the field quality of the finished assembly. This paper describes an on-going Statistical Quality Control study of collar lamination dimensional variation being performed by SSCL Magnet Systems Division Quality Assurance. Samples of collars have been measured using a coordinate measuring machine evaluate manufacturing process capability as well as the overall uniformity of the inventory population of collar laminations. The collar data will be used to predict variation in the coil assembly center and radius for inner and outer top-bottom, left-right coil combinations well as pole angles. Collar results will be combined with azimuthal coil size measurements part of a manufacturing cause and effect model for predicting axial geometric multipoles based on the observed mechanical variation. This work focuses on Prototype Collider Dipole Magnet DCA 102 currently being built at the SSCL MDL in Waxahachie, Texas. This magnet is being made on the same coil curing and collaring mold cavities that were used for the DCA 300 series magnets built at FNAL in 1991--1992 and which were later used in the 1992 Accelerator Systems String Test (ASST). The collars are part of the same procurement used for the DCA300 series magnets.
Full 180° Magnetization Reversal with Electric Fields
Wang, J. J.; Hu, J. M.; Ma, J.; Zhang, J. X.; Chen, L. Q.; Nan, C. W.
2014-01-01
Achieving 180° magnetization reversal with an electric field rather than a current or magnetic field is a fundamental challenge and represents a technological breakthrough towards new memory cell designs. Here we propose a mesoscale morphological engineering approach to accomplishing full 180° magnetization reversals with electric fields by utilizing both the in-plane piezostrains and magnetic shape anisotropy of a multiferroic heterostructure. Using phase-field simulations, we examined a patterned single-domain nanomagnet with four-fold magnetic axis on a ferroelectric layer with electric-field-induced uniaxial strains. We demonstrated that the uniaxial piezostrains, if non-collinear to the magnetic easy axis of the nanomagnet at certain angles, induce two successive, deterministic 90° magnetization rotations, thereby leading to full 180° magnetization reversals. PMID:25512070
Full 180° magnetization reversal with electric fields.
Wang, J J; Hu, J M; Ma, J; Zhang, J X; Chen, L Q; Nan, C W
2014-01-01
Achieving 180° magnetization reversal with an electric field rather than a current or magnetic field is a fundamental challenge and represents a technological breakthrough towards new memory cell designs. Here we propose a mesoscale morphological engineering approach to accomplishing full 180° magnetization reversals with electric fields by utilizing both the in-plane piezostrains and magnetic shape anisotropy of a multiferroic heterostructure. Using phase-field simulations, we examined a patterned single-domain nanomagnet with four-fold magnetic axis on a ferroelectric layer with electric-field-induced uniaxial strains. We demonstrated that the uniaxial piezostrains, if non-collinear to the magnetic easy axis of the nanomagnet at certain angles, induce two successive, deterministic 90° magnetization rotations, thereby leading to full 180° magnetization reversals. PMID:25512070
Full 180° Magnetization Reversal with Electric Fields
NASA Astrophysics Data System (ADS)
Wang, J. J.; Hu, J. M.; Ma, J.; Zhang, J. X.; Chen, L. Q.; Nan, C. W.
2014-12-01
Achieving 180° magnetization reversal with an electric field rather than a current or magnetic field is a fundamental challenge and represents a technological breakthrough towards new memory cell designs. Here we propose a mesoscale morphological engineering approach to accomplishing full 180° magnetization reversals with electric fields by utilizing both the in-plane piezostrains and magnetic shape anisotropy of a multiferroic heterostructure. Using phase-field simulations, we examined a patterned single-domain nanomagnet with four-fold magnetic axis on a ferroelectric layer with electric-field-induced uniaxial strains. We demonstrated that the uniaxial piezostrains, if non-collinear to the magnetic easy axis of the nanomagnet at certain angles, induce two successive, deterministic 90° magnetization rotations, thereby leading to full 180° magnetization reversals.
Bloch electrons in electric and magnetic fields
Alejandro Kunold; Manuel Torres
2000-04-29
We investigate Bloch electrons in two dimensions subject to constant electric and magnetic fields. The model that results from our pursuit is governed by a finite difference equation with a quasienergy spectrum that interpolates between a butterfly-like structure and a Stark ladder structure. These findings ensued from the use of electric and magnetic translation operators.
Fabrication and component testing results for a Nb{sub 3}Sn dipole magnet
Dell`Orco, D.; Scanlan, R.M.; Taylor, C.E.; Lietzke, A.; Caspi, S.; van Oort, J.M.; McInturff, A.D.
1994-10-01
At present, the maximum field achieved in accelerator R&D dipoles is slightly over 10T, with NbTi conductor at 1.8 K. Although Nb{sub 3}Sn has the potential to achieve much higher fields, none of the previous dipoles constructed from Nb{sub 3}Sn have broken the 10T barrier. We report here on the construction of a dipole with high current density Nb{sub 3}Sn with a predicted short sample limit of 13T. A wind and react technique, followed by epoxy impregnation of the fiberglass insulated coils, was used. The problems identified with the use of Nb{sub 3}SD in earlier dipole magnets were investigated in a series of supplemental tests. This includes measurement of the degradation of J{sub c} with transverse strain, cabling degradation, joint resistance measurements, and epoxy strength tests. In addition, coff assembly techniques were developed to ensure that adequate prestress could be applied without damaging the reacted Nb{sub 3}Sn cable. We report here the results of these tests and the construction status of this 50 mm bore dipole.
Jun, James Jaeyoon; Longtin, André; Maler, Leonard
2013-01-01
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. PMID:23805244
Generation of Electric and Magnetic Fields During Detonation of High Explosive Charges in Boreholes
Soloviev, S; Sweeney, J
2004-06-04
We present experimental results of a study of electromagnetic field generation during underground detonation of high explosive charges in holes bored in sandy loam and granite. Test conditions and physico-mechanical properties of the soil exert significant influence on the parameters of electromagnetic signals generated by underground TNT charges with masses of 2 - 200 kg. The electric and magnetic field experimental data are satisfactorily described by an electric dipole model with the source embedded in a layered media.
Calculation and optimization of stray fields of septum dipole magnets
Holmes, Andrew J T
1976-01-01
A theoretical treatment is described of the external stray field of C- shaped septum magnets, such as those designed for the beam extraction systems of the 400 GeV CERN Super Proton Synchrotron. A special conformal transformation of the magnetic plane yields analytic expressions for the four components of the stray field: the septum- shape field (due to the form of the septum conductor), the edge-effect field (due to the mechanical clearance between septum and yoke), the cooling-duct field (due to the presence of these ducts in the septum), and the magnetomotance field (caused by the ampere-turn losses in the yoke). These expressions can be computed by numerical iteration. The septum-shape field turns out to be opposite in sign to the other three, making possible a criterion which creates a minimal stray field for a given magnetic induction. Plots of calculated and measured stray fields are presented for four prototype septum magnets whose total induction is between 0.38 and 1.41 T. (3 refs).
Dipole-quadrupole dynamics during magnetic field reversals Christophe Gissinger
Gissinger, Christophe
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 for geomagnetic reversals, among which we can mention, the analogy with a bistable oscillator 2 , a mean
M. Spata, G.A. Krafft
2011-09-01
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.
Test of Fermilab built, post-ASST, 50-mm-aperture, full length SSC dipole magnets
Kuzminski, J.; Akhmetov, A. [Superconducting Super Collider Lab., Dallas, TX (United States); Bossert, R. [Fermi National Accelerator Lab., Batavia, IL (United States)] [and others
1993-05-01
During 1992 at Fermilab, a series of nine 50-mm-aperture, 15-m-long, SSC superconducting dipole magnets, designed jointly by Fermilab, Brookhaven National Laboratory, and the SSC Laboratory, have been built and successfully cold tested. Seven of these dipole magnets, designate for the Accelerator System String Test (ASST) carried out at SSCL in Dallas, were assembled Fermilab by General Dynamics personnel, and have achieved the nominal operating current level without significant training. In addition, a series of four R&D magnets (DCA320 323) we manufactured at Fermilab to test an alternative insulation schemes. In this paper we present th quench performance of these four R&D magnets, which were cold tested at the Fermilab Magnet Test Facility at nominal temperatures of 4.35 K, 3.85 K, and 3.50 K. An extended characterization test was performed on one of these magnets (DCA322). During this test the magnet was successfully cooled down to superfluid He temperature (1.8 K) and reached a field B {ge} 9.5 T.
Magnetic and electric hotspots with silicon nanodimers.
Bakker, Reuben M; Permyakov, Dmitry; Yu, Ye Feng; Markovich, Dmitry; Paniagua-Domínguez, Ramón; Gonzaga, Leonard; Samusev, Anton; Kivshar, Yuri; Luk'yanchuk, Boris; Kuznetsov, Arseniy I
2015-03-11
The study of the resonant behavior of silicon nanostructures provides a new route for achieving efficient control of both electric and magnetic components of light. We demonstrate experimentally and numerically that enhancement of localized electric and magnetic fields can be achieved in a silicon nanodimer. For the first time, we experimentally observe hotspots of the magnetic field at visible wavelengths for light polarized across the nanodimer's primary axis, using near-field scanning optical microscopy. PMID:25686205
Observation of coupled magnetic and electric domains.
Fiebig, M; Lottermoser, Th; Fröhlich, D; Goltsev, A V; Pisarev, R V
2002-10-24
Ferroelectromagnets are an interesting group of compounds that complement purely (anti-)ferroelectric or (anti-)ferromagnetic materials--they display simultaneous electric and magnetic order. With this coexistence they supplement materials in which magnetization can be induced by an electric field and electrical polarization by a magnetic field, a property which is termed the magnetoelectric effect. Aside from its fundamental importance, the mutual control of electric and magnetic properties is of significant interest for applications in magnetic storage media and 'spintronics'. The coupled electric and magnetic ordering in ferroelectromagnets is accompanied by the formation of domains and domain walls. However, such a cross-correlation between magnetic and electric domains has so far not been observed. Here we report spatial maps of coupled antiferromagnetic and ferroelectric domains in YMnO3, obtained by imaging with optical second harmonic generation. The coupling originates from an interaction between magnetic and electric domain walls, which leads to a configuration that is dominated by the ferroelectromagnetic product of the order parameters. PMID:12397352
The permanent electric dipole moment of thorium sulfide, ThS.
Le, Anh; Heaven, Michael C; Steimle, Timothy C
2014-01-14
Numerous rotational lines of the {18.26}1-X(1)?(+) band system of thorium sulfide, ThS, were recorded near 547.6 nm at a resolution of approximately 30 MHz. Measurements were made under field-free conditions, and in the presence of a static electric field. The field-free spectrum was analyzed to produce rotational and ?-doubling parameters. The Stark shifts induced by the electric field were analyzed to determine permanent electric dipole moments, ??el, of 4.58(10) D and 6.72(5) D for the X(1)?(+) (v = 0) and {18.26}1 states, respectively. The results are compared with the predictions of previous and new electronic structure calculations for ThS, and the properties of isovalent ThO. PMID:24437877
Magnetism and Electricity Activity "Attracts" Student Interest
ERIC Educational Resources Information Center
Roman, Harry T.
2010-01-01
Electricity and magnetism are intimately linked, this relationship forming the basis of the modern electric utility system and the generation of bulk electrical energy. There is rich literature from which to teach students the basics, but nothing drives the point home like having them learn from firsthand experience--and that is what this…
Surveying Students' Conceptual Knowledge of Electricity and Magnetism.
ERIC Educational Resources Information Center
Maloney, David P.; O'Kuma, Thomas L.; Hieggelke, Curtis J.; Van Heuvelen, Alan
2001-01-01
Introduces the Conceptual Survey of Electricity and Magnetism (CSEM) which was developed to assess students' knowledge of topics in electricity and magnetism. Reports on the number of student difficulties in electricity and magnetism. (Contains 23 references.) (Author/YDS)
He, P.; Jain, A., Gupta, R., Skaritka, J., Spataro, C., Joshi, P., Ganetis, G., Anerella, M., Wanderer, P.
2011-03-28
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.
Performance of six 4. 5 m SSC (Superconducting Super Collider) dipole model magnets
Willen, E.; Dahl, P.; Cottingham, J.; Garber, M.; Ghosh, A.; Goodzeit, C.; Green, A.; Herrera, J.; Kahn, S.; Kelly, E.
1986-01-01
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, split iron yoke of 267 mm outer diameter, supported in a cylindrical yoke containment vessel. At 4.5 K the magnets reached a field of about 6.6 T with little training, or the short sample limit of the conductor, and in subcooled (2.6 - 2.4 K) liquid, 8 T was achieved. The allowed harmonics were close to the predicted values, and the unallowed harmonics small. The sextupole trim coil operated well above the required current with little training.
Simulation and Characterization of the MINER{nu}A 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
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.
Geometric-phase-induced false electric dipole moment signals for particles in traps
NASA Astrophysics Data System (ADS)
Pendlebury, J. M.; Heil, W.; Sobolev, Yu.; Harris, P. G.; Richardson, J. D.; Baskin, R. J.; Doyle, D. D.; Geltenbort, P.; Green, K.; van der Grinten, M. G. D.; Iaydjiev, P. S.; Ivanov, S. N.; May, D. J. R.; Smith, K. F.
2004-09-01
Theories are developed to evaluate Larmor frequency shifts, derived from geometric phases, in experiments to measure electric dipole moments (EDM’s) of trapped, atoms, molecules, and neutrons. A part of these shifts is proportional to the applied electric field and can be interpreted falsely as an electric dipole moment. A comparison is made between our theoretical predictions for these shifts and some results from our recent experiments, which shows agreement to within the experimental errors of 15%. The comparison also demonstrates that some trapped particle EDM experiments have reached a sensitivity where stringent precautions are needed to minimize and control such false EDM’s. Computer simulations of these processes are also described. They give good agreement with the analytical results and they extend the study by investigating the influence of varying surface reflection laws in the hard-walled traps considered. They also explore the possibility to suppress such false EDM’s by introducing collisions with buffer gas particles. Some analytic results for frequency shifts proportional to the square of the E field are also given and there are results for the averaging of the B field in the absence of an E field.
QCD corrections to the electric dipole moment of the neutron in the MSSM
Giuseppe Degrassi; Enrico Franco; Schedar Marchetti; Luca Silvestrini
2005-10-18
We consider the QCD corrections to the electric dipole moment of the neutron in the Minimal Supersymmetric Standard Model. We provide a master formula for the Wilson coefficients at the low energy scale including for the first time the mixing between the electric and chromoelectric operators and correcting widely used previous LO estimates. We show that, because of the mixing between the electric and chromoelectric operators, the neutralino contribution is always strongly suppressed. We find that, in general, the effect of the QCD corrections is to reduce the amount of CP violation generated at the high scale. We discuss the perturbative uncertainties of the LO computation, which are particularly large for the gluino-mediated contribution. This motivates our Next-to-Leading order analysis. We compute for the first time the order alpha_s corrections to the Wilson coefficients for the gluino contributions, and recompute the two-loop anomalous dimension for the dipole operators. We show that the large LO uncertainty disappears once NLO corrections are taken into account.
Electrical detection of magnetization reversal without auxiliary magnets
NASA Astrophysics Data System (ADS)
Olejník, K.; Novák, V.; Wunderlich, J.; Jungwirth, T.
2015-05-01
First-generation magnetic random access memories based on anisotropic magnetoresistance required magnetic fields for both writing and reading. Modern all-electrical read/write memories use instead nonrelativistic spin transport connecting the storing magnetic layer with a reference ferromagnet. Recent studies have focused on electrical manipulation of magnetic moments by relativistic spin torques requiring no reference ferromagnet. Here we report the observation of a counterpart magnetoresistance effect in such a relativistic system which allows us to electrically detect the sign of the magnetization without an auxiliary magnetic field or ferromagnet. We observe the effect in a geometry in which the magnetization of a uniaxial (Ga,Mn)As epilayer is set either parallel or antiparallel to a current-induced nonequilibrium spin polarization of carriers. In our structure, this linear-in-current magnetoresistance reaches 0.2% at current density of 106Acm -2 .
TOPICAL REVIEW: Electrical polarization and orbital magnetization: the modern theories
NASA Astrophysics Data System (ADS)
Resta, Raffaele
2010-03-01
Macroscopic polarization P and magnetization M are the most fundamental concepts in any phenomenological description of condensed media. They are intensive vector quantities that intuitively carry the meaning of dipole per unit volume. But for many years both P and the orbital term in M evaded even a precise microscopic definition, and severely challenged quantum-mechanical calculations. If one reasons in terms of a finite sample, the electric (magnetic) dipole is affected in an extensive way by charges (currents) at the sample boundary, due to the presence of the unbounded position operator in the dipole definitions. Therefore P and the orbital term in M—phenomenologically known as bulk properties—apparently behave as surface properties; only spin magnetization is problemless. The field has undergone a genuine revolution since the early 1990s. Contrary to a widespread incorrect belief, P has nothing to do with the periodic charge distribution of the polarized crystal: the former is essentially a property of the phase of the electronic wavefunction, while the latter is a property of its modulus. Analogously, the orbital term in M has nothing to do with the periodic current distribution in the magnetized crystal. The modern theory of polarization, based on a Berry phase, started in the early 1990s and is now implemented in most first-principle electronic structure codes. The analogous theory for orbital magnetization started in 2005 and is partly work in progress. In the electrical case, calculations have concerned various phenomena (ferroelectricity, piezoelectricity, and lattice dynamics) in several materials, and are in spectacular agreement with experiments; they have provided thorough understanding of the behaviour of ferroelectric and piezoelectric materials. In the magnetic case the very first calculations are appearing at the time of writing (2010). Here I review both theories on a uniform ground in a density functional theory (DFT) framework, pointing out analogies and differences. Both theories are deeply rooted in geometrical concepts, elucidated in this work. The main formulae for crystalline systems express P and M in terms of Brillouin-zone integrals, discretized for numerical implementation. I also provide the corresponding formulae for disordered systems in a single k-point supercell framework. In the case of P the single-point formula has been widely used in the Car-Parrinello community to evaluate IR spectra.
Electrical polarization and orbital magnetization: the modern theories.
Resta, Raffaele
2010-03-31
Macroscopic polarization P and magnetization M are the most fundamental concepts in any phenomenological description of condensed media. They are intensive vector quantities that intuitively carry the meaning of dipole per unit volume. But for many years both P and the orbital term in M evaded even a precise microscopic definition, and severely challenged quantum-mechanical calculations. If one reasons in terms of a finite sample, the electric (magnetic) dipole is affected in an extensive way by charges (currents) at the sample boundary, due to the presence of the unbounded position operator in the dipole definitions. Therefore P and the orbital term in M--phenomenologically known as bulk properties--apparently behave as surface properties; only spin magnetization is problemless. The field has undergone a genuine revolution since the early 1990s. Contrary to a widespread incorrect belief, P has nothing to do with the periodic charge distribution of the polarized crystal: the former is essentially a property of the phase of the electronic wavefunction, while the latter is a property of its modulus. Analogously, the orbital term in M has nothing to do with the periodic current distribution in the magnetized crystal. The modern theory of polarization, based on a Berry phase, started in the early 1990s and is now implemented in most first-principle electronic structure codes. The analogous theory for orbital magnetization started in 2005 and is partly work in progress. In the electrical case, calculations have concerned various phenomena (ferroelectricity, piezoelectricity, and lattice dynamics) in several materials, and are in spectacular agreement with experiments; they have provided thorough understanding of the behaviour of ferroelectric and piezoelectric materials. In the magnetic case the very first calculations are appearing at the time of writing (2010). Here I review both theories on a uniform ground in a density functional theory (DFT) framework, pointing out analogies and differences. Both theories are deeply rooted in geometrical concepts, elucidated in this work. The main formulae for crystalline systems express P and M in terms of Brillouin-zone integrals, discretized for numerical implementation. I also provide the corresponding formulae for disordered systems in a single k-point supercell framework. In the case of P the single-point formula has been widely used in the Car-Parrinello community to evaluate IR spectra. PMID:21389484
Effect of Membrane Tension on the Electric Field and Dipole Potential of Lipid Bilayer Membrane
Warshaviak, Dora Toledo; Muellner, Michael J.; Chachisvilis, Mirianas
2011-01-01
The dipole potential of lipid bilayer membrane controls the difference in permeability of the membrane to oppositely charged ions. We have combined molecular dynamics (MD) simulations and experimental studies to determine changes in electric field and electrostatic potential of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) lipid bilayer in response to applied membrane tension. MD simulations based on CHARMM36 force field showed that electrostatic potential of DOPC bilayer decreases by ~45 mV in the physiologically relevant range of membrane tension values (0 to 15 dyn/cm). The electrostatic field exhibits a peak (~0.8×109 V/m) near the water/lipid interface which shifts by 0.9 Å towards the bilayer center at 15 dyn/cm. Maximum membrane tension of 15 dyn/cm caused 6.4% increase in area per lipid, 4.7% decrease in bilayer thickness and 1.4% increase in the volume of the bilayer. Dipole-potential sensitive fluorescent probes were used to detect membrane tension induced changes in DOPC vesicles exposed to osmotic stress. Experiments confirmed that dipole potential of DOPC bilayer decreases at higher membrane tensions. These results are suggestive of a potentially new mechanosensing mechanism by which mechanically induced structural changes in the lipid bilayer membrane could modulate the function of membrane proteins by altering electrostatic interactions and energetics of protein conformational states. PMID:21722624
Effect of membrane tension on the electric field and dipole potential of lipid bilayer membrane.
Warshaviak, Dora Toledo; Muellner, Michael J; Chachisvilis, Mirianas
2011-10-01
The dipole potential of lipid bilayer membrane controls the difference in permeability of the membrane to oppositely charged ions. We have combined molecular dynamics (MD) simulations and experimental studies to determine changes in electric field and electrostatic potential of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) lipid bilayer in response to applied membrane tension. MD simulations based on CHARMM36 force field showed that electrostatic potential of DOPC bilayer decreases by ~45mV in the physiologically relevant range of membrane tension values (0 to 15dyn/cm). The electrostatic field exhibits a peak (~0.8×10(9)V/m) near the water/lipid interface which shifts by 0.9Å towards the bilayer center at 15dyn/cm. Maximum membrane tension of 15dyn/cm caused 6.4% increase in area per lipid, 4.7% decrease in bilayer thickness and 1.4% increase in the volume of the bilayer. Dipole-potential sensitive fluorescent probes were used to detect membrane tension induced changes in DOPC vesicles exposed to osmotic stress. Experiments confirmed that dipole potential of DOPC bilayer decreases at higher membrane tensions. These results are suggestive of a potentially new mechanosensing mechanism by which mechanically induced structural changes in the lipid bilayer membrane could modulate the function of membrane proteins by altering electrostatic interactions and energetics of protein conformational states. PMID:21722624
G. V. Krashevskaya; V. A. Kurnaev; M. M. Tsventoukh
Recent results of plasma confinement investigations in the compact double-dipole device Magnetor are presented. Two coaxial coils placed in the same plane with opposite currents create the poloidal magnetic field with the ellipsoidal separatrix. High mirror-ratio reduces particle losses on the small supports of the internal coil. Plasma is created by ECR on 2.45GHz at 10µTorr. The poloidal configuration with
Possible enhancement of magnetic dipole transitions between Gamow-Teller and isobaric analog states
H. Sagawa; Toshio Suzuki; Nguyen van Giai
1995-01-01
A new decay scheme between Gamow-Teller (GT) resonances and isobaric analog states (IAS) by magnetic dipole transitions is studied. The sum rule of M1 transitions between IAS and GT states is found to be significantly enhanced compared to the non-energy-weighted sum rule of the parent state. Calculated enhancement factors can be as large as ~2.5 for 48Sc and 90Nb, and
3D ANSYS quench simulation of cosine theta Nb3Sn high field dipole magnets
R. Yamada; E. Marcsin; A. Lee; M. Wake
2004-01-01
To study detailed quench behavior of cosine theta Nb3Sn high field dipole magnets a 3D simulation program is made using ANSYS finite element analysis program. The simulation program reproduces the detailed end structure, as well as the straight section, based from a CAD file of I-DEAS. It can calculate the thermal and its resulting mechanical stress distribution inside the coil
Using permanent magnets to boost the dipole field for the High-Energy LHC
Frank Zimmermann; Yoshihisa Iwashita
2012-01-01
The High-Energy LHC (HE-LHC) will be a new accelerator in the LHC tunnel based on novel dipole magnets, with a field up to 20 T, which are proposed to be realized by a hybrid-coil design, comprising blocks made from Nb- Ti, Nb3Sn and HTS, respectively. Without the HTS the field would be only 15 T. In this note we propose
Shell model estimate of electric dipole moments in medium and heavy nuclei
NASA Astrophysics Data System (ADS)
Teruya, Eri; Yoshinaga, Naotaka; Higashiyama, Koji
2015-05-01
Existence of the electric dipole moment (EDM) is deeply related with time-reversal invariance. The EDMof a diamagnetic atom is mainly induced by the nuclear Schiff moment. After carrying out the shell model calculations to obtain wavefunctions for Xe isotopes, we evaluate nuclear Schiff moments for Xe isotopes to estimate their atomic EDMs. We estimate the contribution from each single particle orbital for the Schiff moment. It is found that the contribution on the Schiff moment is very different from orbital to orbital.
New concept for a neutron electric dipole moment search using a pulsed beam
NASA Astrophysics Data System (ADS)
Piegsa, Florian M.
2013-10-01
A concept to search for a neutron electric dipole moment (nEDM) is presented, which employs a pulsed neutron beam instead of the established use of storable ultracold neutrons (UCN). The technique takes advantage of the high peak flux and the time structure of a next-generation pulsed spallation source like the planned European Spallation Source. It is demonstrated that the sensitivity for a nEDM can be improved by several orders of magnitude compared to the best beam experiments performed in the 1970s and can compete with the sensitivity of UCN experiments.
Search for the Neutron Electric Dipole Moment at the SNS at Oak Ridge
Kolarkar, Ameya [Physics Department, 590 Commonwealth Ave., Boston University, Boston, MA 02215 (United States)
2010-02-10
The possible existence of a non-zero electric dipole moment (EDM) of the neutron is of fundamental interest for our understanding of the nature of electro-weak and strong interactions. The experimental search for this moment has the potential to reveal new sources of T and CP violation and to challenge calculations that propose extensions to the Standard Model. A new experiment being developed at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory seeks to lower the current EDM limit of the neutron by a factor of 50 to 100 over the present upper limit of 2.9x10{sup -26} e cm.
New Limit on the Permanent Electric Dipole Moment of 199Hg
M. V. Romalis; W. C. Griffith; J. P. Jacobs; E. N. Fortson
2001-01-01
We present the first results of a new search for a permanent electric dipole\\u000amoment of the ^{199}Hg atom using a UV laser. Our measurements give d(Hg)= -\\u000a(1.06 +\\/- 0.49 +\\/- 0.40) 10^{-28} e cm. We interpret the result as an upper\\u000alimit |d(Hg)| < 2.1 10^{-28} e cm (95% C.L.), which sets new constraints on\\u000atheta_{QCD}, chromo-EDMs of
NASA Astrophysics Data System (ADS)
Karn, J.; Biallas, G.; Guerra, A.; Harwood, L.
1997-05-01
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.
Cryostat design for the Superconducting Super Collider 50mm aperture dipole magnet
Nicol, T.H. (Fermi National Accelerator Lab., Batavia, IL (USA)); Tsavalas, Y.P. (General Electric Co., Florence, SC (USA). Medical Systems)
1990-09-01
The cryostat of an SSC dipole magnet consists of all magnet components except the cold mass assembly. It serves to support the cold mass accurately and reliably within the vacuum vessel, provide all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. It must function reliably during storage, shipping and handling, normal magnet operation, quenches, and seismic excitations and must be manufacturable at low cost. The major components of the cryostat are the vacuum vessel, thermal shields, multilayer insulation (MLI) system, cryogenic piping, interconnections, and suspension system. The overall design of a cryostat for superconducting accelerator magnets requires consideration of fluid flow, proper selection of materials for their thermal and structural performance at both ambient and operating temperature, and knowledge of the environment to which the magnets will be subjected over the course their 25 year expected life. This paper describes the design of the current SSC collider dipole magnet cryostat and includes discussions on the thermal, structural, and dynamic considerations involved in the development of each of the major systems. 7 refs., 1 fig., 2 tabs.
Design study of 15-Tesla RHQT Nb3Al block type dipole magnet
Yamada, R.; Ambrosio, G.; Barzi, E.; Kashikin, V.; Kikuchi, A.; Novitski, I.; Takeuchi, T.; Wake, M.; Zlobin, A.; /Fermilab /NIMC, Tsukuba /KEK, Tsukuba
2005-09-01
The design study of the block type 15-Tesla RHQT Nb{sub 3}Al dipole magnet, and its merits over Nb{sub 3}Sn magnets are presented. The copper stabilized RHQT Nb{sub 3}Al strand is now becoming commercially available for the application to the accelerator magnets. A 1 mm diameter RHQT Nb{sub 3}Al strand with filament size about 50 {mu}, non-copper Jc about 1000 A/mm{sup 2} at 15 Tesla at 4.2K, copper ratio of 50%, can now be produced over several hundred meters. The stress and strain characteristics of the Nb{sub 3}Al strand are superior to the Nb{sub 3}Sn strand. Another advantage is that it can tolerate a longitudinal strain up to 0.55%. The RHQT Nb{sub 3}Al Rutherford cable will have less chance of contamination of the stabilizer, compared to Nb{sub 3}Sn cable. These characteristics of the RHQT Nb{sub 3}Al will be beneficial for designing and producing 15-Tesla dipole magnets. An example 15-Tesla magnet cross section, utilizing the RHQT Nb{sub 3}Sn strand is presented. A systematic investigation on RHQT Nb{sub 3}Al strands, its Rutherford cables, and building a small racetrack magnet for cable testing are proposed.
Dependence of Magnetic Field Quality on Collar Supplier and Dimensions in the Main LHC Dipole
Bellesia, B; Santoni, C; Todesco, E
2006-01-01
In order to keep the electro-magnetic forces and to minimize conductor movements, the superconducting coils of the main Large Hadron Collider dipoles are held in place by means of austenitic steel collars. Two suppliers provide the collars necessary for the whole LHC production, which has now reached more than 800 collared coils. In this paper we first assess if the different collar suppliers origin a noticeable difference in the magnetic field quality measured at room temperature. We then analyze the measurements of the collar dimensions carried out at the manufacturers, comparing them to the geometrical tolerances. Finally we use a magneto-static model to evaluate the expected spread in the field components induced by the actual collar dimensions. These spreads are compared to the magnetic measurements at room temperature over the magnet production in order to identify if the collars, rather than other components or assembly process, can account for the measured magnetic field effects. It has been found tha...
The design and manufacture of the Fermilab Main Injector Dipole Magnet
Brown, B.C.; Chester, N.S.; Harding, D.J.; Martin, P.S.
1992-03-01
Fermilab's new Main Injector Ring (MIR) will replace the currently operating Main Ring to provide 150 GeV Proton and Antiproton beams for Tevetron injection, and rapid cycling, high intensity, 120 GeV Proton beams for Antiproton production. To produce and maintain the required high beam quality, high intensity, and high repetition rate, conventional dipole magnets with laminated iron core and water cooled copper conductor were chosen as the bending magnet. A new magnet design having low inductance, large copper cross section, and field uniformity sufficient for high intensity injection and efficient slow resonant extraction, is required to obtain the needed geometric aperture, dynamic aperture, and operational reliability. The current Main Injector Ring lattice design requires the use of 344 of these magnets. 216 of these magnets are to be 6 m long, and 128 are to be 4 m long.
The design and manufacture of the Fermilab Main Injector Dipole Magnet
Brown, B.C.; Chester, N.S.; Harding, D.J.; Martin, P.S.
1992-03-01
Fermilab`s new Main Injector Ring (MIR) will replace the currently operating Main Ring to provide 150 GeV Proton and Antiproton beams for Tevetron injection, and rapid cycling, high intensity, 120 GeV Proton beams for Antiproton production. To produce and maintain the required high beam quality, high intensity, and high repetition rate, conventional dipole magnets with laminated iron core and water cooled copper conductor were chosen as the bending magnet. A new magnet design having low inductance, large copper cross section, and field uniformity sufficient for high intensity injection and efficient slow resonant extraction, is required to obtain the needed geometric aperture, dynamic aperture, and operational reliability. The current Main Injector Ring lattice design requires the use of 344 of these magnets. 216 of these magnets are to be 6 m long, and 128 are to be 4 m long.
Mechanical analysis of the Nb3Sn dipole magnet HD1
Ferracin, Paolo; Bartlett, Scott E.; Caspi, Shlomo; Dietderich,Daniel R.; Gourlay, Steve A.; Hannaford, Carles R.; Hafalia, Aurelio R.; Lietzke, Alan F.; Mattafirri, Sara; Sabbi, Gianluca
2005-04-14
The Superconducting Magnet Group at Lawrence Berkeley National Laboratory (LBNL) has recently fabricated and tested HD1, a Nb{sub 3}Sn dipole magnet. The magnet reached a 16 T field, and exhibited training quenches in the end regions and in the straight section. After the test, HD1 was disassembled and inspected, and a detailed 3D finite element mechanical analysis was done to investigate for possible quench triggers. The study led to minor modifications to mechanical structure and assembly procedure, which were verified in a second test (HD1b). This paper presents the results of the mechanical analysis, including strain gauge measurements and coil visual inspection. The adjustments implemented in the magnet structure are reported and their effect on magnet training discussed.
Mechanical Analysis of the Nb3Sn Dipole Magnet HD1
Ferracin, Paolo; Bartlett, Scott E.; Caspi, Shlomo; Dietderich, Daniel R.; Gourlay, Steve A.; Hannaford, Charles R.; Hafalia, Aurelio R.; Lietzke, Alan F.; Mattafirri, Sara; Sabbi, Gianluca
2005-06-01
The Superconducting Magnet Group at Lawrence Berkeley National Laboratory (LBNL) has recently fabricated and tested HD1, a Nb3Sn dipole magnet. The magnet reached a 16 T field, and exhibited training quenches in the end regions and in the straight section. After the test, HD1 was disassembled and inspected, and a detailed 3D finite element mechanical analysis was done to investigate for possible quench triggers. The study led to minor modifications to mechanical structure and assembly procedure, which were verified in a second test (HD1b). This paper presents the results of the mechanical analysis, including strain gauge measurements and coil visual inspection. The adjustments implemented in the magnet structure are reported and their effect on magnet training discussed.
Electric control of magnetism at room temperature.
Wang, Liaoyu; Wang, Dunhui; Cao, Qingqi; Zheng, Yuanxia; Xuan, Haicheng; Gao, Jinlong; Du, Youwei
2012-01-01
In the single-phase multiferroics, the coupling between electric polarization (P) and magnetization (M) would enable the magnetoelectric (ME) effect, namely M induced and modulated by E, and conversely P by H. Especially, the manipulation of magnetization by an electric field at room-temperature is of great importance in technological applications, such as new information storage technology, four-state logic device, magnetoelectric sensors, low-power magnetoelectric device and so on. Furthermore, it can reduce power consumption and realize device miniaturization, which is very useful for the practical applications. In an M-type hexaferrite SrCo(2)Ti(2)Fe(8)O(19), large magnetization and electric polarization were observed simultaneously at room-temperature. Moreover, large effect of electric field-controlled magnetization was observed even without magnetic bias field. These results illuminate a promising potential to apply in magnetoelectric devices at room temperature and imply plentiful physics behind them. PMID:22355737
Electric control of magnetism at room temperature
Wang, Liaoyu; Wang, Dunhui; Cao, Qingqi; Zheng, Yuanxia; Xuan, Haicheng; Gao, Jinlong; Du, Youwei
2012-01-01
In the single-phase multiferroics, the coupling between electric polarization (P) and magnetization (M) would enable the magnetoelectric (ME) effect, namely M induced and modulated by E, and conversely P by H. Especially, the manipulation of magnetization by an electric field at room-temperature is of great importance in technological applications, such as new information storage technology, four-state logic device, magnetoelectric sensors, low-power magnetoelectric device and so on. Furthermore, it can reduce power consumption and realize device miniaturization, which is very useful for the practical applications. In an M-type hexaferrite SrCo2Ti2Fe8O19, large magnetization and electric polarization were observed simultaneously at room-temperature. Moreover, large effect of electric field-controlled magnetization was observed even without magnetic bias field. These results illuminate a promising potential to apply in magnetoelectric devices at room temperature and imply plentiful physics behind them. PMID:22355737
Measurements of the persistent current decay and snapback effect in Tevatron dipole magnets
Velev, G.V.; Bauer, P.; DiMarco, J.; Hanft, R.; Lamm, M.; Schlabach, P.; Sylvester, C.; Tartaglia, M.; Tompkins, J.C.; /Fermilab
2006-08-01
A systematic study of the persistent current decay and snapback effect in the fields of Tevatron accelerator dipoles was performed at the Fermilab Magnet Test Facility (MTF). The decay and snapback were measured under a range of conditions including variations of the current ramp parameters and magnet operational history. The study has mostly focused on the dynamic behavior of the normal sextupole component. In addition, the paper presents the persistent current effects observed in the other allowed field harmonics as well. The results provide new information about the previously observed ''excess'' decay during the first several seconds of the sextupole decay during injection and the correlation between the snapback amplitude and its duration.
Magnetic and electrical properties of Martian particles
NASA Technical Reports Server (NTRS)
Olhoeft, G. R.
1991-01-01
The only determinations of the magnetic properties of Martian materials come from experiments on the two Viking Landers. The results suggest Martian soil containing 1 to 10 percent of a highly magnetic phase. Though the magnetic phase mineral was not conclusively identified, the predominate interpretation is that the magnetic phase is probably maghemite. The electrical properties of the surface of Mars were only measured remotely by observations with Earth based radar, microwave radiometry, and inference from radio-occultation of Mars orbiting spacecraft. No direct measurements of electrical properties on Martian materials have been performed.
The role of hydrodynamic forces in the confinement and assembly of magnetic dipoles
NASA Astrophysics Data System (ADS)
Prikockis, M.; Chen, A.; Sooryakumar, R.
2014-03-01
The confinement of interacting magnetic dipoles provides a means to probe the assembly of and many-body coupling within a mesoscopic system. Using a previously developed confinement method (Scientific Reports 3, 3124 (2013)), we investigate the role of hydrodynamic forces in one such mesoscopic system that supports a fluid borne suspension of microscopic beads that contain embedded superparmagnetic particles. Our confinement platform consists of a thin permalloy disk patterned on a silicon surface and a precessing magnetic field. By adjusting the orientation of the field, inter-particle dipolar and trap confinement forces are tuned - thereby enabling the plane-confined beads to repel or attract one another. At a specific field orientation, the dipolar interaction is weakened to provide a regime where the hydrodynamic forces, stemming from rotational motion of the beads, play a role in bead assembly. We investigate the dependence of dipole ordering on the hydrodynamic forces by varying the frequency of the field rotation in this special field configuration. This represents a unique system where the hydrodynamic forces of fluid borne magnets are tuned independently of the magnetic forces in a magnetic dipolar confinement scheme.
A. B. Kukushkin; N. L. Marusov; V. S. Neverov; I. B. Semenov; K. V. Cherepanov; P. V. Minashin
2009-01-01
Numerical modeling of electrodynamic aggregation is carried out for a random\\u000aensemble of magnetized nanodust taken as a many body system of strongly\\u000amagnetized thin rods (i.e., one-dimensional static magnetic dipoles), which\\u000apossess electric conductivity and static electric charge, screened with its own\\u000astatic plasma sheath. The self-assembling of quasi-linear filaments from an\\u000aensemble of randomly situated basic blocks and
A Relativistic Many-Body Analysis of the Electric Dipole Moment of $^{223}$Rn
B. K. Sahoo; Yashpal Singh; B. P. Das
2014-10-20
We report the results of our {\\it ab initio} relativistic many-body calculations of the electric dipole moment (EDM) $d_A$ arising from the electron-nucleus tensor-pseudotensor (T-PT) interaction, the interaction of the nuclear Schiff moment (NSM) with the atomic electrons and the electric dipole polarizability $\\alpha_d$ for $^{223}$Rn. Our relativistic random-phase approximation (RPA) results are substantially larger than those of lower-order relativistic many-body perturbation theory (MBPT) and the results based on the relativistic coupled-cluster (RCC) method with single and double excitations (CCSD) are the most accurate to date for all the three properties that we have considered. We obtain $d_A = 4.85(6) \\times 10^{-20} C_T \\ |e| \\ cm$ from T-PT interaction, $d_A=2.89(4) \\times 10^{-17} {S/(|e|\\ fm^3)}$ from NSM interaction and $\\alpha_d=35.27(9) \\ ea_0^3$. The former two results in combination with the measured value of $^{223}$Rn EDM, when it becomes available, could yield the best limits for the T-PT coupling constant, EDMs and chromo-EDMs of quarks and $\\theta_{QCD}$ parameter, and would thereby shed light on leptoquark and supersymmetric models that predict CP violation.
Measurements of the electric dipole polarizabilities of the alkali halide dimers
Kremens, R.; Bederson, B.; Jaduszliwer, B.; Stockdale, J.; Tino, A.
1984-08-15
We report the first measurements of the average electric dipole polarizabilities of five alkali halide dimers. A combined monomer-dimer molecular beam deflection pattern in an inhomogeneous electric field is subject to an appropriate computational analysis to extract the polarizabilities. A simple combination of bond and effective ionic models to estimate the polarizabilities gives reasonably good agreement with the measured values. The values are, in units of 10/sup -24/ cm/sup 2/, (KF)/sub 2/:25.3 +- 3.2; (KCl)/sub 2/:28.6 +- 3.0; (RbCl)/sub 2/:43.4 +- 4.2; (CsCl)/sub 2/:36.6 +- 5.0; (CsF)/sub 2/:21.2 +- 2.6.
Measurements of the electric dipole polarizabilities of the alkali halide dimers
Kremens, R.; Bederson, B.; Jaduszliwer, B.; Stockdale, J.; Tino, A.
1984-04-15
We report the first measurements of the average electric dipole polarizabilities of five alkali halide dimers. A combined monomer--dimer molecular beam deflection pattern in an inhomogeneous electric field is subject to an appropriate computational analysis to extract the polarizabilities. A simple combination of bond and effective ionic models to estimate the polarizabilities gives reasonably good agreement with the measured values. The values are, in units of 10/sup -24/ cm/sup 2/, (DF(/sub 2/: 25.3 +- 3.2; (KDl)/sub 2/: 28.6 +- 3.0; (RbCl)/sub 2/:43.4 +- 4.2; (CsCl)/sub 2/:36.6 +- 5.0; (CsF)/sub 2/:21.2 +- 2.6.
Magnetic dipole excitations in nuclei: elementary modes of nucleonic motion
Kris Heyde; Peter von Neumann-Cosel; Achim Richter
2010-04-21
The nucleus is one of the most multi-faceted many-body systems in the universe. It exhibits a multitude of responses depending on the way one 'probes' it. With increasing technical advancements of beams at the various accelerators and of detection systems the nucleus has, over and over again, surprised us by expressing always new ways of 'organized' structures and layers of complexity. Nuclear magnetism is one of those fascinating faces of the atomic nucleus we discuss in the present review. We shall not just limit ourselves to presenting the by now very large data set that has been obtained in the last two decades using various probes, electromagnetic and hadronic alike and that presents ample evidence for a low-lying orbital scissors mode around 3 MeV, albeit fragmented over an energy interval of the order of 1.5 MeV, and higher-lying spin-flip strength in the energy region 5 - 9 MeV in deformed nuclei, nor to the presently discovered evidence for low-lying proton-neutron isovector quadrupole excitations in spherical nuclei. To the contrary, we put the experimental evidence in the perspectives of understanding the atomic nucleus and its various structures of well-organized modes of motion and thus enlarge our discussion to more general fermion and bosonic many-body systems.
Magnetic dipole excitations in nuclei: elementary modes of nucleonic motion
Heyde, Kris; Richter, Achim
2010-01-01
The nucleus is one of the most multi-faceted many-body systems in the universe. It exhibits a multitude of responses depending on the way one 'probes' it. With increasing technical advancements of beams at the various accelerators and of detection systems the nucleus has, over and over again, surprised us by expressing always new ways of 'organized' structures and layers of complexity. Nuclear magnetism is one of those fascinating faces of the atomic nucleus we discuss in the present review. We shall not just limit ourselves to presenting the by now very large data set that has been obtained in the last two decades using various probes, electromagnetic and hadronic alike and that presents ample evidence for a low-lying orbital scissors mode around 3 MeV, albeit fragmented over an energy interval of the order of 1.5 MeV, and higher-lying spin-flip strength in the energy region 5 - 9 MeV in deformed nuclei, nor to the presently discovered evidence for low-lying proton-neutron isovector quadrupole excitations in...
Magnetic dipole excitations in nuclei: Elementary modes of nucleonic motion
NASA Astrophysics Data System (ADS)
Heyde, Kris; von Neumann-Cosel, Peter; Richter, Achim
2010-07-01
The nucleus is one of the most multifaceted many-body systems in the Universe. It exhibits a multitude of responses depending on the way one “probes” it. With increasing technical advancements of beams at the various accelerators and of detection systems the nucleus has, over and over again, surprised us by expressing always new ways of “organized” structures and layers of complexity. Nuclear magnetism is one of those fascinating faces of the atomic nucleus discussed in the present review. We shall not just limit ourselves to presenting the by now large data set that has been obtained in the past two decades using various probes, electromagnetic and hadronic alike and that presents ample evidence for a low-lying orbital scissors mode around 3MeV , albeit fragmented over an energy interval of the order of 1.5MeV , and higher-lying spin-flip strength in the energy region 5-9MeV in deformed nuclei nor to the presently discovered evidence for low-lying proton-neutron isovector quadrupole excitations in spherical nuclei. To the contrary, the experimental evidence is put in the perspectives of understanding the atomic nucleus and its various structures of well-organized modes of motion and thus enlarges the discussion to more general fermion and bosonic many-body systems.
HD1: Design and Fabrication of a 16 Tesla Nb3Sn DipoleMagnet
Hafalia, A.R.; Bartlett, S.E.; Capsi, S.; Chiesa, L.; Dietderich,D.R.; Ferracin, P.; Goli, M.; Gourlay, S.A.; Hannaford, C.R.; Highley,H.; Lietzke, A.F.; Liggins, N.; Mattafirri, S.; McInturff, A.D.; Nyman,M.; Sabbi, G.L.; Scanlan, R.M.; Swanson, J.
2003-11-10
The Lawrence Berkeley National Laboratory (LBNL) Superconducting Magnet Group has completed the design, fabrication and test of HD1, a 16 T block-coil dipole magnet. State of the art Nb{sub 3}Sn conductor was wound in double-layer racetrack coils and supported by an iron yoke and a tensioned aluminum shell. In order to prevent conductor movement under magnetic forces up to the design field, a coil pre-stress of 150 MPa was required. To achieve this level without damaging the brittle conductor, the target stress was generated during cool-down to 4.2 K by exploiting the thermal contraction differentials between yoke and shell. Accurate control of the shell tension during assembly was obtained using pressurized bladders and interference load keys. An integrated 3D CAD model was used to optimize magnetic and mechanical design and analysis.
Effect of rapid evolution of magnetic tilt angle on a newborn magnetar's dipole radiation
NASA Astrophysics Data System (ADS)
Xu, Ming; Huang, Yong-Feng
2015-07-01
We study the electromagnetic radiation from a newborn magnetar whose magnetic tilt angle decreases rapidly. We calculate the evolution of the angular spin frequency, the perpendicular component of the surface magnetic field strength, and the energy loss rate through magnetic dipole radiation. We show that the spin-down of the magnetar experiences two stages characterized by two different timescales. The apparent magnetic field decreases with the decrease of the tilt angle. We further show that the energy loss rate of the magnetar is very different from that in the case of a fixed tilt angle. The evolution of the energy loss rate is consistent with the overall light curves of gamma-ray bursts which show a plateau structure in their afterglow stage. Our model supports the idea that some gamma-ray bursts with a plateau phase in their afterglow stage may originate from newborn millisecond magnetars. Supported by the National Natural Science Foundation of China.
Magnetic dipole moment of the $\\Delta(1232)$ in chiral perturbation theory
Hacker, C; Gegelia, J; Scherer, S
2006-01-01
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 order the isoscalar anomalous magnetic moment receives a (real) loop contribution. Moreover, due to the unstable nature of the $\\Delta (1232)$, at next-to-leading order the isovector anomalous magnetic moment not only receives a real but also an imaginary loop contribution.
Axial variations in the magnetic field of superconducting dipoles and quadrupoles
Ghosh, A.K.; Robins, K.E.; Sampson, W.B.
1993-09-01
A periodic variation in the magnetic field along the axis has been observed in both quadrupole and dipole magnets made from superconducting cable. This oscillation is present in all components of the field and has a wavelength equal to the transposition length of the cable. In general the amplitude of these variations increases with magnet current and is not reversible. The residual field patten at zero current depends on the energizing cycle and increases with time spent at high field. The decay of the oscillations has a complex time dependence which contains some extremely long time constants. Unbalanced currents in the individual strands of the cable appear to cause these effects and the field variations can only be completely erased by raising the magnet above its critical temperature.
Performance analysis of HD1: a 16 Tesla Nb3Sn dipole Magnet
Mattafirri, S.; Bartlett, S.E.; Bish, P.A.; Caspi, S.; Dietderich, D.R.; Ferracin, P.; Gourlay, S.A.; Hannaford, C.R.; Hafalia, A.R.; Lau, W.G.; Lietzke, A.F.; McInturff, A.D.; Nyman, M.; Sabbi, G.L.; Scanlan, R.M.
2005-06-01
The Superconducting Magnet Group at Lawrence Berkeley National Laboratory (LBNL) has been developing technology for high field accelerator magnets from brittle conductors. HD1 is a single bore block dipole magnet using two, double-layer Nb{sub 3}Sn flat racetrack coils. The magnet was tested in October 2003 and reached a bore peak field of 16 T (94.5% of short sample). The average quench current plateau appeared to be limited by 'stick slip' conductor motions. Diagnostics recorded quench origins and preload distributions. Cumulative deformation of the mechanical structure has been observed. Quench velocity in different field regions has been measured and compared with model predictions. The results obtained during the HD1 test are presented and discussed.
HD1: Design and Fabrication of a 16 Tesla Nb3Sn Dipole Magnet
Hafalia, A.R.; Barlett, S.E.; Caspi, S.; Chiesa, L.; Dietderich, D.R.; Ferracin, P.; Goli, M.; Gourlay, S.A.; Hannaford, C.R.; Higley, H.; Lietzke, A.F.; Liggins, N.; Mattafirri, S.; McInturff, A.D.; Myman, M.; Sabbi, G.L.; Scanlan, R.M.; Swanson, J.
2003-10-01
The Lawrence Berkeley National Laboratory (LBNL) Supcrconducting Magnet Group has completed the design, fabrication and tcst of HD1, a 16 T block-coil dipole magnet. State of the art Nb{sub 3}Sn conductor was wound in double-layer racetrack coils and supported by an iron yoke and a tensioned aluminum shell. In order to prevent conductor movement under magnetic forces up to the design field, a coil prestress of 150 MPa was required. To achieve this level without damaging the brittle conductor, the target stress was generated during cool-down to 4.2 K by exploiting the thermal contraction differentials between yoke and shell. Accurate control of the shell tension during assembly was obtained using pressurized bladders and interference load keys. An integrated 3D CAD model was used to optimize magnetic and mechanical design and analysis.