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1

Electric Dipole Moment of Magnetic Monopole  

E-print Network

The electric dipole moment of magnetic monopoles with spin is studied in the N=2 supersymmetric gauge theory. The dipole moments of the electric charge distributions, as well as the dipole moments due to the magnetic currents, are calculated. The contribution of charge distribution of the fermion to the gyroelectric ratio is expressed by using zeta(3).

Makoto Kobayashi

2006-12-26

2

Magnetic and electric dipoles for physics beyond the standard model  

NASA Astrophysics Data System (ADS)

The magnetic and electric dipole moments of particles have been significant topics to explore physics beyond the standard model. The anomalous magnetic dipole moment of the muon has shown a sizable deviation from the standard model prediction. Many people consider that the deviation comes from new physics beyond the standard model, so it provides a significance for new physics beyond the standard model. We discuss its significance by building a model in the standard model extension. The search for the electric dipole will uncover the violation of one of the fundamental discrete symmetries, CP violation. The charged leptons do not have CP violating interactions in the standard model. A lepton electric dipole moment is induced by the CKM phase in the quark sector via a diagram with a closed quark loop, so any positive detection of an electric dipole moment will imply the presence of a non-CKM CP violating source and lead to the scale of new physics. We consider new CP violating sources, and predictions of the sizable electric dipole moments are discussed. Finally, Dirac fermionic dark matter near the electroweak scale with nonzero dipoles is introduced and its implications are discussed. In addition, QCD radiative corrections to pair annihilation of spin-1 bosonic dark matter is presented and we show that the radiative correction can play a significant role to analyze dark matter phenomenology for the certain models.

Heo, Jae Ho

3

Dynamically fluctuating electric dipole moments in fullerene-based magnets  

NASA Astrophysics Data System (ADS)

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

Kambe, Takashi; Oshima, Kokichi

2014-09-01

4

Measurement of AC electrical characteristics of SSC superconducting dipole magnets  

SciTech Connect

Experiments were conducted to measure the AC electrical characteristics of SSC superconducting dipole magnets over the frequency range of 0.1 Hz to 10 kHz. A magnet equivalent circuit representing the magnet DC inductance, eddy current losses, coil-to-ground and turn-to-turn capacitance, was synthesized from the experimental data. This magnet equivalent circuit can be used to predict the current ripple distribution along the superconducting magnet string and can provide dynamic information for the design of the collider current regulation loop.

Smedley, K M [Superconducting Super Collider Lab., Dallas, TX (United States)] [Superconducting Super Collider Lab., Dallas, TX (United States); Shafer, R E [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States)

1992-01-01

5

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

SciTech Connect

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

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

2011-04-15

6

Magnetic and Electric Dipole Constraints on Extra Dimensions and Magnetic Fluxes  

E-print Network

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

Aaron J. Roy; Myron Bander

2008-05-10

7

Dynamically fluctuating electric dipole moments in fullerene-based magnets.  

PubMed

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

Kambe, Takashi; Oshima, Kokichi

2014-01-01

8

Dynamically fluctuating electric dipole moments in fullerene-based magnets  

PubMed Central

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

Kambe, Takashi; Oshima, Kokichi

2014-01-01

9

Table of nuclear magnetic dipole and electric quadrupole moments  

SciTech Connect

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

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

2005-05-01

10

Mapping and Quantifying Electric and Magnetic Dipole Luminescence at the nanoscale  

E-print Network

We report on an experimental technique to quantify the relative importance of electric and magnetic dipole luminescence from a single nanosource in structured environments. By attaching a $Eu^{3+}$-doped nanocrystal to a near-field scanning optical microscope tip, we map the branching ratios associated to two electric dipole and one magnetic dipole transitions in three dimensions on a gold stripe. The relative weight of the electric and magnetic radiative local density of states can be recovered quantitatively, based on a multilevel model. This paves the way towards the full electric and magnetic characterization of nanostructures for the control of luminescence at the single emitter level.

Aigouy, L; Gredin, P; Mortier, M; Carminati, R

2014-01-01

11

Mapping and Quantifying Electric and Magnetic Dipole Luminescence at the Nanoscale  

NASA Astrophysics Data System (ADS)

We report on an experimental technique to quantify the relative importance of electric and magnetic dipole luminescence from a single nanosource in structured environments. By attaching a Eu3+-doped nanocrystal to a near-field scanning optical microscope tip, we map the branching ratios associated with two electric dipole and one magnetic dipole transitions in three dimensions on a gold stripe. The relative weights of the electric and magnetic radiative local density of states can be recovered quantitatively, based on a multilevel model. This paves the way towards the full electric and magnetic characterization of nanostructures for the control of single emitter luminescence.

Aigouy, L.; Cazé, A.; Gredin, P.; Mortier, M.; Carminati, R.

2014-08-01

12

Effect of Electric and Magnetic Fields on Spin Dynamics in the Resonant Electric Dipole Moment Experiment  

E-print Network

A buildup of the vertical polarization in the resonant electric dipole moment (EDM) experiment [Y. F. Orlov, W. M. Morse, and Y. K. Semertzidis, Phys. Rev. Lett. 96, 214802 (2006)] is affected by a horizontal electric field in the particle rest frame oscillating at a resonant frequency. This field is defined by the Lorentz transformation of an oscillating longitudinal electric field and a uniform vertical magnetic one. The effect of a longitudinal electric field is significant, while the contribution from a magnetic field caused by forced coherent longitudinal oscillations of particles is dominant. The effect of electric field on the spin dynamics was not taken into account in previous calculations. This effect is considerable and leads to decreasing the EDM effect for the deuteron and increasing it for the proton. The formula for resonance strengths in the EDM experiment has been derived. The spin dynamics has been calculated.

Alexander J. Silenko

2006-04-11

13

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

E-print Network

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

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

2014-01-01

14

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

NASA Astrophysics Data System (ADS)

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 charge and thus a nonzero internal electric field. This thesis is an experimental study to see if this property continues to hold for tiny subnanometer metal particles called clusters (2--200 atom, R < 1 nm). We have measured the electric dipole moments of metal clusters made from 15 pure elements using a molecular beam electric deflection technique. We find that the observed dipole moments vary a great deal across the periodic table. Alkali metals have zero dipole moments, while transition metals and lanthanides all have dipole moments which are highly size dependent. In most cases, the measured dipole moments are independent of temperature (T = 20--50 K), and when there is a strong temperature dependence this suggests that there is a new state of matter present. Our interpretation of these results are that those clusters which have a nonzero dipole moment are non-metallic, in the sense that their electrons must be localized and prevented from moving to screen the internal field associated with a permanent dipole moment. This interpretation gives insight to several related phenomena and applications. We briefly discuss an example cluster system RhN where the measured electric dipole moments appear to be correlated with a the N2O reactivity. Finally, we discuss a series of magnetic deflection experiments on lanthanide clusters (Pr, Ho, Tb, and Tm). The magnetic response of these clusters is very complex and highly sensitive to size and temperature. We find that PrN (which is non-magnetic in the bulk) becomes magnetic in clusters and Tm N clusters have magnetic moments lower than the atomic value as well as the bulk saturation value implying that the magnetic order in the cluster involves non-collinear or antiferromagnetic order. HoN and TbN show very similar size dependent trends suggesting that these clusters have similar structures.

Bowlan, John

15

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

16

Electric Quadrupole and Magnetic Dipole Moments of Mirror Nuclei and Self-Conjugate Nuclei  

NASA Astrophysics Data System (ADS)

A transformation, which brings about the unification of the nuclear collective and single particle models, yields sumrules for the magnetic dipole moments and for the electric quadrupole moments of mirror nuclei. These sumrules are applied to cases, for which the numerical values of these moments are known.Translated AbstractElektrische Qadrupol- und Magnetische Dipolmomente von Spiegelkernen und Kernen mit N = ZMit Hilfe einer Transformation, die die Vereinigung von Kollektiv- und Schalenmodell liefert, lassen sich Summenregeln für die magnetischen Dipol- und die elektrischen Quadrupolmomente von Spiegelkernen ableiten. Diese Summenregeln werden auf Spiegelkerne angewandt, für die die numerischen Werte der Momente bekannt sind.

Zickendraht, W.

17

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

NASA Astrophysics Data System (ADS)

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

Lang, Michael Loren

18

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

NASA Astrophysics Data System (ADS)

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

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

2009-06-01

19

Electric dipole two equal magnitude,  

E-print Network

Electric dipole � two equal magnitude, opposite charged particles separated by distance d What's the electric field at point P due to the dipole? Electric Dipole #12;Approximate E field for a dipole is Define electric dipole moment, p as, The direction of p and d is from the negative to positive E field along

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

20

Measurement of the anomalous magnetic and electric dipole moments of the tau lepton  

Microsoft Academic Search

We analyse e+e????? events using 100pb?1 of data collected by the L3 experiment during the 1991-1995 LEP runs at the Z pole. From the energy of the photons and their isolation from the tau decay products, we determine the anomalous magnetic and electric dipole moments of the tau to be, respectively:a?=0.004±0.027±0.023;d?=(0.0±1.5±1.3)×10?16e·cm.This is a direct measurement of these ? form factors

M. Acciarri; O. Adriani; M. Aguilar-Benitez; S P Ahlen; J. Alcaraz; G. Alemanni; James V Allaby; A. Aloisio; M. G. Alviggi; H. Anderhub; V. P. Andreev; T. Angelescu; F. Anselmo; A. Arefiev; T. Azemoon; P. Bagnaia; L. Baksay; R. C. Ball; S. Banerjee; K. Banicz; A. Barczyk; R. Barillère; L. Barone; P. Bartalini; A. Baschirotto; M. Basile; R. Battiston; A. Bay; F. Becattini; U. Becker; F. Behner; J. Berdugo; P. Berges; B. Bertucci; S. Bhattacharya; M. Biasini; A. Biland; G. M. Bilei; J. J. Blaising; S. C. Blyth; G. J. Bobbink; R. Bock; A. Böhm; L. Boldizsar; B. Borgia; D. Bourilkov; M. Bourquin; D. Boutigny; S. Braccini; J. G. Branson; V. Brigljevic; I. C. Brock; A. Buffini; J. D. Burger; W. J. Burger; X. D. Cai; M. Campanelli; G. Cara Romeo; A. M. Cartacci; J. Casaus; G. Castellini; F. Cavallari; N. Cavallo; C. Cecchi; M. Cerrada; F. Cesaroni; M. Chamizo; Y. H. Chang; U. K. Chaturvedi; S. V. Chekanov; M. Chemarin; A. Chen; G M Chen; H. F. Chen; H. S. Chen; M. Chen; G. Chiefari; C. Y. Chien; L. Cifarelli; F. Cindolo; C. Civinini; I. Clare; G. Coignet; A. P. Colijn; N. Colino; S. Costantini; F. Cotorobai; B. de la Cruz; A. Csilling; T. S. Dai; R. D'Alessandro; R. de Asmundis; A. Degré; K. Deiters; P. Denes; F. DeNotaristefani; M. Diemoz; D. van Dierendonck; F. Di Lodovico; C. Dionisi; M. Dittmar; A. Dominguez; M. T. Dova; E. Drago; D. Duchesneau; P. Duinker; I. Duran; S. Easo; H. El Mamouni; A. Engler; F. J. Eppling; F. C. Erné; J. P. Ernenwein; M A Falagán; R. Faccini; S. Falciano; A. Favara; J. Fay; O. Fedin; M. Felcini; T. Ferguson; F. Ferroni; H. Fesefeldt; E. Fiandrini; J. H. Field; F. Filthaut; P. H. Fisher; I. Fisk; G. Forconi; L. Fredj; K. Freudenreich; C. Furetta; Yu. Galaktionov; S. N. Ganguli; P. Garcia-Abia; M. Gataullin; S. S. Gau; S. Gentile; J. Gerald; N. Gheordanescu; S. Giagu; S. Goldfarb; J. Goldstein; Z. F. Gong; A. Gougas; G. Gratta; M. W. Gruenewald; R. van Gulik; V. K. Gupta; A. Gurtu; L. J. Gutay; D. Haas; B. Hartmann; A. Hasan; D. Hatzifotiadou; T. Hebbeker; A. Hervé; P. Hidas; J. Hirschfelder; W. C. van Hoek; H. Hofer; H. Hoorani; S. R. Hou; G. Hu; I. Iashvili; B. N. Jin; L. W. Jones; P. de Jong; I. Josa-Mutuberria; A. Kasser; R. A. Khan; D. Kamrad; J. S. Kapustinsky; Y. Karyotakis; M. Kaur; M. N. Kienzle-Focacci; D. Kim; J. K. Kim; S. C. Kim; W. W. Kinnison; A. Kirkby; D. Kirkby; J. Kirkby; D. Kiss; W. Kittel; A. Klimentov; A. Kopp; I. Korolko; V. Koutsenko; R. W. Kraemer; A. Kunin; P. Lacentre; P. Ladron de Guevara; G. Landi; C. Lapoint; K. Lassila-Perini; P. Laurikainen; A. Lavorato; M. Lebeau; A. Lebedev; P. Lebrun; P. Lecomte; P. Le Coultre; H. J. Lee; C. Leggett; J. M. Le Goff; R. Leiste; E. Leonardi; P. Levtchenko; C. Li; C. H. Lin; W. T. Lin; F. L. Linde; Z. A. Liu; W. Lohmann; E. Longo; W. Lu; Y. S. Lu; K. Lübelsmeyer; C. Luci; D. Luckey; L. Luminari; W. Lustermann; W. G. Ma; M. Maity; G. Majumder; L. Malgeri; A. Malinin; C. Maña; D. Mangeol; P. Marchesini; G. Marian; A. Marin; J. P. Martin; F. Marzano; G. G. G. Massaro; K. Mazumdar; S. Mele; L. Merola; M Von der Mey; W. J. Metzger; Y. Mi; D. Migani; A. Mihul; A. J. W. van Mil; H. Milcent; G. Mirabelli; J. Mnich; P. Molnar; B. Monteleoni; R. Moore; T. Moulik; R. Mount; F. Muheim; A. J. M. Muijs; S. Nahn; M. Napolitano; F. Nessi-Tedaldi; H. Newman; T. Niessen; A. Nippe; A. Nisati; H. Nowak; Y. D. Oh; G. Organtini; R. Ostonen; S. Palit; C. Palomares; D. Pandoulas; S. Paoletti; P. Paolucci; H. K. Park; I. H. Park; G. Pascale; G. Passaleva; S. Patricelli; T. Paul; M. Pauluzzi; C. Paus; F. Pauss; D. Peach; Y. J. Pei; S. Pensotti; D. Perret-Gallix; B. Petersen; S. Petrak; A. Pevsner; D. Piccolo; M. Pieri; P. A. Piroué; E. Pistolesi; V Pozhidaev; M. Pohl; V. Pojidaev; H. Postema; J. Pothier; N. Produit; D. Prokofiev; J. Quartieri; G. Rahal-Callot; N. Raja; P. G. Rancoita; M. Rattaggi; G. Raven; P. Razis; D. Ren; M. Rescigno; S. Reucroft; T. van Rhee; S. Riemann; K. Riles; O. Rind; A. Robohm; J. Rodin; B. P. Roe; L. Romero; S. Rosier-Lees; Ph. Rosselet; S. Roth; J. A. Rubio; D. Ruschmeier; H. Rykaczewski; J. Salicio; E. Sanchez; M E Sarakinos; G. Sauvage; C. Schäfer; V. Schegelsky; S. Schmidt-Kaerst; D. Schmitz; M. Schneegans; N. Scholz; H. Schopper; D. J. Schotanus; G. Schwering; C. Sciacca; D. Sciarrino; L. Servoli; S. Shevchenko; N. Shivarov; V. Shoutko; J. Shukla; E. Shumilov; A. Shvorob; T. Siedenburg; D. Son; V. Soulimov; B. Smith; P. Spillantini; M. Steuer; D. P. Stickland; H. Stone; B. Stoyanov; A. Straessner; K. Sudhakar; G. Sultanov; L. Z. Sun; G. F. Susinno; H. Suter; J. D. Swain; X. W. Tang; L. Tauscher; Samuel C. C. Ting; S. M. Ting; S. C. Tonwar; J. Tóth; C. Tully; K. L. Tung; Y. Uchida; J. Ulbricht; E. Valente; G. Vesztergombi; I. Vetlitsky; G. Viertel; M. Vivargent; S. Vlachos; H. Vogel; H. Vogel; I. Vorobiev; A. A. Vorobyov; M. Wadhwa; W. Wallraff; J. C. Wang; X. L. Wang

1998-01-01

21

Magneto-Electric Dipole Antenna Arrays  

E-print Network

A planar magneto-electric (ME) dipole antenna array is proposed and demonstrated by both full-wave analysis and experiments. The proposed structure leverages the infinite wavelength propagation characteristic of composite right/left-handed (CRLH) transmission lines to form high-gain magnetic radiators combined with radial conventional electric radiators, where the overall structure is excited by a single differential feed. The traveling-wave type nature of the proposed ME-dipole antenna enables the formation of directive arrays with high-gain characteristics and scanning capability. Peak gains of 10.84 dB and 5.73 dB are demonstrated for the electric dipole and magnetic-dipole radiation components, respectively.

Gupta, Shulabh; Caloz, Christophe

2014-01-01

22

Electric dipole radiation near a mirror  

SciTech Connect

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

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

2010-05-15

23

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

24

CrRb: A molecule with large magnetic and electric dipole moments  

SciTech Connect

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

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

2010-05-15

25

Equivalent source magnetic dipoles revisited  

NASA Astrophysics Data System (ADS)

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

Dyment, J.; Arkani-Hamed, J.

26

Electric-dipole-induced spin resonance in disordered semiconductors  

E-print Network

ARTICLES Electric-dipole-induced spin resonance in disordered semiconductors MATHIAS DUCKHEIM One of the hallmarks of spintronics is the control of magnetic moments by electric fields enabled in such structures is electric-dipole-induced spin resonance (EDSR), where the radio-frequency fields driving

Loss, Daniel

27

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

E-print Network

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

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

2014-08-28

28

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

SciTech Connect

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

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

2012-01-01

29

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

PubMed

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

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

2012-09-01

30

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

31

About possibility to measure an electric dipole moment (EDM) of nuclei in the range $10^{-27} ÷10^{-32}$ $e \\cdot cm$ in experiments for search of time-reversal violating generation of magnetic and electric fields  

E-print Network

The possibility to measure an electric dipole moment (EDM) of nuclei in the range $10^{-27} \\div 10^{-32}$ $e \\cdot cm$ in experiments for search of time-reversal violating generation of magnetic and electric fields is discussed.

Vladimir Baryshevsky

2004-02-19

32

Magnetic-dipole photo-recombination in ultracold hydrogen plasma  

NASA Astrophysics Data System (ADS)

The cross section for magnetic-dipole photodisintegration of the negative hydrogen ion has been calculated within the zero-range-potential approximation. The magnetic-dipole cross section for photodetachment within the very narrow range of energy near the process threshold is predicted to dominate over the electric-dipole one. It is shown that in ultracold hydrogen plasma at temperatures below T = 3.29 × 10-4 K the magnetic-dipole photo-recombination becomes an important mechanism of electron capture by hydrogen atoms.

Baltenkov, A. S.

2014-05-01

33

Nuclear Electric Dipole Moment Calculations  

NASA Astrophysics Data System (ADS)

One of the most important constraints on CP violation in the nucleon and NN interaction is provided by electric dipole moment (EDM) limits for neutral diamagnetic atoms, particularly 199Hg. To extract CP-violating couplings from experiment, one must relate the atomic EDM to the underlying nuclear CP-odd moments, a task complicated by the atomic response, which largely shields the nucleus from the applied external electric field. The residual response -- the Schiff moment -- depends on corrections such as the finite size of the nucleus. Conventional Schiff-moment calculations have largely ignored one consequence of the screening: the cancellation between direct and polarization diagrams, which yields an answer that is suppressed by two powers of RN/RA, where RN and RA are the nuclear and atomic sizes, requires one to identify all other terms that contribute to the same order in the RN/RA power counting. We show that such terms arise from nuclear excitations associated with the dipole charge and transverse electric multipole operators, and discuss the consequences. We also describe higher T-odd moments that contribute up to the same order in the counting, and point out interesting nuclear structure and experimental consequences.

Haxton, Wick

2010-11-01

34

Magnetic dipole and electric quadrupole moments of the neutron-deficient bismuth isotopes  

NASA Astrophysics Data System (ADS)

The complete hyperfine structures of the A = 202, 203 and 204 bismuth isotopes have been observed in the 306.7 nm line using an extremely sensitive gas cell technique of laser spectroscopy. The magnetic moments, quadrupole moments and relative changes in the mean square charge radii have been extracted and have been used to study the bulk and valence nuclear behaviour around 208Pb. The trends of the quadrupole moments of the proton-particle, neutron-hole ground and isomeric systems are observed to be very nearly identical throughout the Z ? 82, N ? 126 region. Furthermore the correspondence between the behaviour of Qs and the behaviour of the ground state charge radii demonstrates that the global systematics of this region are closer than those of any other.

Campbell, P.; Behr, J. A.; Billowes, J.; Gwinner, G.; Sprouse, G. D.; Xu, F.

1996-02-01

35

Magnetic particles with shifted dipoles  

NASA Astrophysics Data System (ADS)

We present simulations and analytical calculations for a system of magnetic nano-particles that possess a dipole moment that is shifted out of the center of mass, towards the surface, leading to a further asymmetry of the dipolar interaction. In our contribution, we discuss the peculiarities of ground state small clusters, both, with and without an external magnetic field. Small clusters help us to get an insight into the inter-particle interactions and form a building block for studies of larger systems. Without external magnetic field, the ground state structure changes from chains and rings with parallel alignment of moments, usually observed in dipolar particles (Prokopieva et al., 2009 [1]), to pairs and triangles with close to anti-parallel orientation of moments, when the shift of the dipole is increased. We also present magnetization properties of larger systems at finite temperature and observe the influence of the shift in particular on the initial slope of the magnetization curve, namely, the initial susceptibility.

Kantorovich, Sofia; Weeber, Rudolf; Cerdà, Joan J.; Holm, Christian

2011-05-01

36

Numerical Based Linear Model for Dipole Magnets  

SciTech Connect

In this paper, we discuss an algorithm for constructing a numerical linear optics model for dipole magnets from a 3D field map. The difference between the numerical model and K. Brown's analytic approach is investigated and clarified. It was found that the optics distortion due to the dipoles' fringe focusing must be properly taken into account to accurately determine the chromaticities. In NSLS-II, there are normal dipoles with 35-mm gap and dipoles for infrared sources with 90-mm gap. This linear model of the dipole magnets is applied to the NSLS-II lattice design to match optics parameters between the DBA cells having dipoles with different gaps.

Li,Y.; Krinsky, S.; Rehak, M.

2009-05-04

37

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

E-print Network

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

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

2006-07-17

38

Dipole Relaxation in an Electric Field.  

ERIC Educational Resources Information Center

Derives an expression for the orientational entropy of a rigid rod (electric dipole) from Boltzmann's equation. Subsequent application of Newton's second law of motion produces Debye's classical expression for the relaxation of an electric dipole in a viscous medium. (Author/GS)

Neumann, Richard M.

1980-01-01

39

Electric dipoles on the Bloch sphere  

E-print Network

The time evolution of a two-level quantum mechanical system can be geometrically described using the Bloch sphere. By mapping the Bloch sphere evolution onto the dynamics of oscillating electric dipoles, we provide a physically intuitive link between classical electromagnetism and the electric dipole transitions of atomic & molecular physics.

Vutha, Amar C

2014-01-01

40

Magnetic dipole discharges. III. Instabilities  

SciTech Connect

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

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

2013-08-15

41

Classical states of an electric dipole in an external magnetic field: Complete solution for the center of mass and trapped states  

NASA Astrophysics Data System (ADS)

We study the classical behavior of an electric dipole in the presence of a uniform magnetic field. Using the Lagrangian formulation, we obtain the equations of motion, whose solutions are represented in terms of Jacobi functions. We also identify two constants of motion, namely, the energy E and a pseudomomentumC?. We obtain a relation between the constants that allows us to suggest the existence of a type of bound states without turning points, which are called trapped states. These results are consistent with and complementary to previous results.

Atenas, Boris; del Pino, Luis A.; Curilef, Sergio

2014-11-01

42

Electric Dipole Moments of Fundamental Particles  

E-print Network

Electric dipole moment (EDM) experiments are at the fore-front of search for physics beyond the standard model. The next generation searches promise to improve by several orders of magnitude the current EDM sensitivity levels.

Yannis K. Semertzidis

2004-01-13

43

Electric dipole emission by fullerenes and buckyonions  

E-print Network

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.

Susana Iglesias-Groth

2005-09-15

44

Magnetic Dipole Field 3D Model  

NSDL National Science Digital Library

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

Christian, Wolfgang

2012-08-11

45

Linear chains of dipoles and magnetic susceptibility  

NASA Astrophysics Data System (ADS)

The dipole-dipole interactions may lead to the linear chain formation in the ferrofluids. When the dipolar interaction energy is much larger than the thermal energy, the average length of the chains becomes much larger than 1. This strongly influences on the magnetic susceptibility ? which is enhanced in comparison to its Langevin value ?L by a factor of 2.

Gorenstein, Mark I.; Greiner, Walter

2014-01-01

46

QED vacuum fluctuations and induced electric dipole moment of the neutron  

Microsoft Academic Search

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

C. A. Dominguez; H. Falomir; M. Ipinza; M. Loewe; S. Kohler; J. C. Rojas

2009-01-01

47

$?$ electric dipole moment with polarized beams  

E-print Network

High luminosity Super B/Flavor factories, near and on top of the $\\Upsilon$ resonances, allow for a detailed investigation of CP-violation in $\\tau$ physics. In particular, bounds on the $\\tau$ electric dipole moment can be obtained from CP-odd observables. We perform an independent analysis from other low and high energy data. For polarized electron beam a CP-odd asymmetry, associated to the normal polarization term, can be used to set stringent bounds on the $\\tau$ electric dipole moment.

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

2007-07-11

48

Inclusion of magnetic dipole–dipole and hydrodynamic interactions in implant-assisted magnetic drug targeting  

Microsoft Academic Search

Mathematical modelling of the implant-assisted magnetic drug targeting system of Avilés, Ebner and Ritter is performed. In order to model the agglomeration of particles known to occur in this system, the magnetic dipole–dipole and hydrodynamic interactions are included. Such interactions were calculated previously by Mikkelsen et al. under low magnetic fields (~0.05T) in microfluidic systems. Here, a higher magnetic field

P. J. Cregg; Kieran Murphy; Adil Mardinoglu

2009-01-01

49

Searches for Permanent Electric Dipole Moments (EDM)  

E-print Network

(~10-11 at T=30 K) Ultra-Cold Neutrons (UCN) The ILL UCN Source Materials used for UCN storage: #12;The SQUIDs to detect 3He spin precession 3He capture/4He scintillation detection #12;UCN Source #12;NeutronSearches for Permanent Electric Dipole Moments (EDM) of Atoms, Molecules, and the Neutron Dmitry

Pines, Alexander

50

NEUTRON ELECTRIC-DIPOLE MOMENT, ULTRACOLD NEUTRONS  

E-print Network

.5. Scintillation detection 55 eigenstates of the spin in an oscillating field 26 7.6. Sources of cold neutrons 56 4NEUTRON 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

51

Effect of spin excitations with simultaneous magnetic- and electric-dipole character on the static magnetoelectric properties of multiferroic materials  

NASA Astrophysics Data System (ADS)

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.

Szaller, Dávid; Bordács, Sándor; Kocsis, Vilmos; Rõõm, Toomas; Nagel, Urmas; Kézsmárki, István

2014-05-01

52

Incipient magnetic rotation? A magnetic dipole band in 104Cd  

E-print Network

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

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

2000-07-05

53

Electric Dipole Moments of Neutron-Odd Nuclei  

E-print Network

The electric dipole moments (EDMs) of neutron-odd nuclei with even protons are systematically evaluated. We first derive the relation between the EDM and the magnetic moment operators by making use of the core polarization scheme. This relation enables us to calculate the EDM of neutron-odd nuclei without any free parameters. From this calculation, one may find the best atomic system suitable for future EDM experiments.

Takehisa Fujita; Sachiko Oshima

2011-02-15

54

Electric dipole moment of light nuclei  

SciTech Connect

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.

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

55

The Case of the Disappearing Magnetic Dipole  

ERIC Educational Resources Information Center

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

Gough, W.

2008-01-01

56

Circular current loops, magnetic dipoles and spherical harmonic analysis.  

USGS Publications Warehouse

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

Alldredge, L.R.

1980-01-01

57

Large magnetic field instabilities induced by magnetic dipole transitions  

Microsoft Academic Search

We present a new mechanism that will limit very high magnetic fields which have been conjectured to exist in connection with some astrophysical phenomena. Low lying strongly interacting particles and resonances mixing with each other via magnetic dipole QED couplings force a vacuum instability for large external magnetic fields. These mixings limit fields to a few GeV2.

Myron Bander; H. R. Rubinstein

1992-01-01

58

Large muon electric dipole moment from flavor?  

SciTech Connect

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.

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

59

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

SciTech Connect

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

SEMERTZIDIS, Y.K.

2005-05-23

60

Instantaneous Power Radiated from Magnetic Dipole Moments  

E-print Network

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.

Morley, Peter D

2014-01-01

61

Instantaneous Power Radiated from Magnetic Dipole Moments  

E-print Network

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.

Peter D. Morley; Douglas J. Buettner

2014-07-04

62

Neutron electric dipole moment and dressed spin  

NASA Astrophysics Data System (ADS)

The neutron electric dipole moment (EDM) experiment has played a unique role in examining the violation of fundamental symmetries and understanding the nature of electroweak and strong interaction. A non-zero neutron EDM is one of direct evidence for CP and T violation and has the potential to reveal the origin of CP violation and to explore physics beyond the Standard Model. A new neutron EDM experiment will be built to improve a factor of 100 by using a novel technique of ultra-cold neutrons(UCN) in superfluid 4He at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL). In the experiment, 3He in the measurement cell will be used as a neutron spin analyzer and a comagnetometer. The absorption between UCN and 3He atoms will emit scintillation light in the superfluid 4He depending on the angle between nuclear spins of two particles. Consequently, the neutron precession frequency can be derived by the scintillation light amplitude. Furthermore, the 3He precession frequency can be measured by the superconducting quantum interference device (SQUID). A dressed-spin technique will also be applied to measure the small precession frequency change due to a non-zero neutron EDM. The dressed-spin technique is used to modify the effective precession frequencies of neutrons and 3He atoms to make them equal by applying an oscillatory field (dressing field) that is perpendicular to the static magnetic field. The phenomenon of the dressed spin for 3He in a cell should be demonstrated before the proposed neutron EDM experiment. A successful measurement over a broad range of the amplitude and frequency of the dressing field was done at the University of Illinois. The observed effects can be explained by using quantum optics formalism. The formalism is diagonalized to solve the solution and confirms the data. In addition, the application of the dressed-spin technique was investigated. The modulation and the feedback loop technique should be considered with the dressed-spin technique for the measurement of the small EDM effect. The modulation of the dressing field arbitrarily changes the relative precession frequency between UCN and 3He. Through the feedback loop, the effective neutron precession frequency can be measured. The corresponding sensitivity of neutron EDM will be estimated. A future neutron EDM experiment could be improved if the dressed-spin technique can be carefully considered and applied.

Chu, Ping-Han

63

Magnetic field decay in model SSC dipoles  

SciTech Connect

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

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

1988-08-01

64

Generalized dyons and magnetic dipoles: The issue of angular momentum  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

65

An electrically charged doubly spinning dipole black ring  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

66

Pulsar Pair Cascades in a Distorted Magnetic Dipole Field  

E-print Network

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

Harding, Alice K

2010-01-01

67

PULSAR PAIR CASCADES IN A DISTORTED MAGNETIC DIPOLE FIELD  

SciTech Connect

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

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

2011-01-01

68

Pulsar Pair Cascades in a Distorted Magnetic Dipole Field  

NASA Astrophysics Data System (ADS)

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

Harding, Alice K.; Muslimov, Alex G.

2011-01-01

69

Pulsar Pair Cascades in a Distorted Magnetic Dipole Field  

NASA Technical Reports Server (NTRS)

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

Harding, Alice K.; Muslimov, Alex G.

2010-01-01

70

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

NASA Astrophysics Data System (ADS)

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

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

2007-06-01

71

Development of a simulation for measuring neutron electric dipole moment  

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

72

A search for the electric dipole of the electron  

SciTech Connect

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

Abdullah, K.F.

1989-08-01

73

Search for the Neutron Electric Dipole Moment  

SciTech Connect

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

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

2010-08-04

74

Search for the Neutron Electric Dipole Moment  

NASA Astrophysics Data System (ADS)

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 2.9×10-6 e-cm. In this talk, I review the basic measurement principles of neutron EDM searches, then discuss a new experiment to be carried out in the United States at the Spallation Neutron Source with ultracold neutrons and an in-situ 3He "co-magnetometer".

Plaster, Brad

2010-08-01

75

Magnetic dipole discharges. I. Basic properties  

SciTech Connect

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

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

2013-08-15

76

Electric dipole moment of the electron and of the neutron  

NASA Technical Reports Server (NTRS)

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

Barr, S. M.; Zee, A.

1990-01-01

77

New measurements of the neutron electric dipole moment  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

78

Electron Electric Dipole Moment induced by Octet-Colored Scalars  

E-print Network

An appended sector of two octet-colored scalars, each an electroweak doublet, is an interesting extension of the simple two Higgs doublet model motivated by the minimal flavor violation. Their rich CP violating interaction gives rise to a sizable electron electric dipole moment, besides the quark electric dipole moment via the two-loop contribution of Barr-Zee mechanism.

Jae Ho Heo; Wai-Yee Keung

2007-12-31

79

Inclusion of magnetic dipole-dipole and hydrodynamic interactions in implant-assisted magnetic drug targeting  

NASA Astrophysics Data System (ADS)

Mathematical modelling of the implant-assisted magnetic drug targeting system of Avilés, Ebner and Ritter is performed. In order to model the agglomeration of particles known to occur in this system, the magnetic dipole-dipole and hydrodynamic interactions are included. Such interactions were calculated previously by Mikkelsen et al. under low magnetic fields (~0.05 T) in microfluidic systems. Here, a higher magnetic field (0.7 T) is considered and the effect of interactions on two nanoparticles with a seed implant is calculated. The calculations were performed with the open-source software OpenFOAM. Different initial positions are considered and the system performance is assessed in terms of capture cross section. Inclusion of both interactions was seen to alter the capture cross section of the system by up to 7% in absolute terms.

Cregg, P. J.; Murphy, Kieran; Mardinoglu, Adil

2009-12-01

80

Pair Cascades and Deathlines in Offset Magnetic Dipole Fields  

NASA Technical Reports Server (NTRS)

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.

Harding, Alice; Muslimov, Alex

2010-01-01

81

The search for permanent electric dipole moments  

SciTech Connect

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

Kirch, Klaus [PSI-Villigen - ETH Zürich

2013-02-13

82

Nucleon tensor charges and electric dipole moments  

E-print Network

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 enhance the contribution of the singly-represented valence-quark relative to that of the doubly-represented quark for each quantity considered herein. 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 40% more than the doubly-represented $u$-quark; and in connection with the proton's tensor charges, $\\delta_T u$, $\\delta_T d$, the r...

Pitschmann, Mario; Roberts, Craig D; Schmidt, Sebastian M

2014-01-01

83

Nuclear Electric Dipole Moment of 3He  

SciTech Connect

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

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

2008-04-08

84

Dipole Magnet from High Tc Superconductor  

NASA Astrophysics Data System (ADS)

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

Nielsen, Gunver; Zangenberg, Nikolaj; Hazelton, Drew; Hauge, Nils; Nielsen, Bjarne Roger; Møller, Søren Pape; Baurichter, Arnd

85

Plasma expansion in the presence of a dipole magnetic field  

SciTech Connect

Simulations of the initial expansion of a plasma injected into a stationary magnetized background plasma in the presence of a dipole magnetic field are carried out in two dimensions with a kinetic ion, massless fluid electron (hybrid) electromagnetic code. For small values of the magnetic dipole, the injected ions have large gyroradii compared to the scale length of the dipole field and are essentially unmagnetized. As a result, these ions expand, excluding the ambient magnetic field and plasma to form a diamagnetic cavity. However, for stronger magnetic dipoles, the ratio of the gyroradii of the injected ions to the dipole field scale length is small so that they remain magnetized, and hence trapped in the dipole field, as they expand. The trapping and expansion then lead to additional plasma currents and resulting magnetic fields that not only exclude the background field but also interact with the dipole field in a more complex manner that stretches the closed dipole field lines. A criterion to distinguish between the two regimes is derived and is then briefly discussed in the context of applying the results to the plasma sail scheme for the propulsion of small spacecraft in the solar wind.

Winske, D.; Omidi, N. [Applied Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); SciberNet, Inc., Solana Beach, California 92075 (United States)

2005-07-15

86

Effect of dipole-dipole interaction on self-control magnetization oscillation in double-domain nanomagnets  

NASA Astrophysics Data System (ADS)

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.

Gao, Y. J.; Guo, Y. J.; Liu, J.-M.

2012-03-01

87

Development of Cellular Magnetic Dipoles in Magnetotactic Bacteria  

PubMed Central

Magnetotactic bacteria benefit from their ability to form cellular magnetic dipoles by assembling stable single-domain ferromagnetic particles in chains as a means to navigate along Earth's magnetic field lines on their way to favorable habitats. We studied the assembly of nanosized membrane-encapsulated magnetite particles (magnetosomes) by ferromagnetic resonance spectroscopy using Magnetospirillum gryphiswaldense cultured in a time-resolved experimental setting. The spectroscopic data show that 1), magnetic particle growth is not synchronized; 2), the increase in particle numbers is insufficient to build up cellular magnetic dipoles; and 3), dipoles of assembled magnetosome blocks occur when the first magnetite particles reach a stable single-domain state. These stable single-domain particles can act as magnetic docks to stabilize the remaining and/or newly nucleated superparamagnetic particles in their adjacencies. We postulate that docking is a key mechanism for building the functional cellular magnetic dipole, which in turn is required for magnetotaxis in bacteria. PMID:20713012

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

2010-01-01

88

Electric-Dipole Active Two-Magnon Excitation in ab Spiral Spin Phase of a Ferroelectric Magnet Gd0.7Tb0.3MnO3  

NASA Astrophysics Data System (ADS)

A broad continuum-like spin excitation (1-10 meV) with a peak structure around 2.4 meV has been observed in the ferroelectric ab spiral spin phase of Gd0.7Tb0.3MnO3 by using terahertz (THz) time-domain spectroscopy. Based on a complete set of light-polarization measurements, we identify the spin excitation active for the light E vector only along the a-axis, which grows in intensity with lowering temperature even from above the magnetic ordering temperature but disappears upon the transition to the A-type antiferromagnetic phase. Such an electric-dipole active spin excitation as observed at THz frequencies can be ascribed to the two-magnon excitation in terms of the unique polarization selection rule in a variety of the magnetically ordered phases.

Kida, Noriaki; Yamasaki, Yuichi; Shimano, Ryo; Arima, Taka-hisa; Tokura, Yoshinori

2008-12-01

89

QED vacuum fluctuations and induced electric dipole moment of the neutron  

SciTech Connect

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

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

2009-08-01

90

QED vacuum fluctuations and induced electric dipole moment of the neutron  

E-print Network

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.

C. A. Dominguez; H. Falomir; M. Ipinza; S. Kohler; M. Loewe; J. C. Rojas

2009-07-13

91

QED vacuum fluctuations and induced electric dipole moment of the neutron  

E-print Network

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.

Domínguez, C A; Ipinza, M; Köhler, S; Loewe, M; Rojas, J C

2009-01-01

92

Magnetic Field Measurements of an HTS Retrofit Synchrotron Dipole  

Microsoft Academic Search

A copper coil dipole magnet from the National Syn- chrotronLightSource(NSLS)atBrookhavenNationalLaboratory (BNL) has been retrofitted by HTS-110 Ltd with coils made from Bi-2223 wire and a self-contained cryogenic cooling system, while keeping the magnet's original iron yoke. This modified bending dipole, which is the first such known retrofit HTS-based acceler- ator magnet, provides the benefits of a compact coil design to

J. Muratore; J. Escallier; G. Ganetis; A. K. Ghosh; R. C. Gupta; P. He; A. Jain; P. Joshi; P. Wanderer; M. Fee; M. Christian

2011-01-01

93

Vortex strings in electric dipole radiation near a mirror  

NASA Astrophysics Data System (ADS)

The energy flow pattern of the radiation emitted by an oscillating electric dipole near a mirror has a complicated structure, including numerous singularities and vortices. We consider the flow lines of energy in the plane through the surface normal and the oscillation direction of the dipole. It is shown that the vortices are due to the vanishing of the magnetic field at their centers. The locations of the vortices have the appearance of beads on strings, and there are four such strings. The rotation direction of the energy flow for each vortex on a given string is the same. There are two strings with clockwise rotation and two strings with counterclockwise rotation. Field lines of energy flow either start or end at the center of a vortex. For a given string, field lines end at each vortex or field lines start at each vortex. There are two strings on which field lines end at the centers of the vortices, and there are two strings on which field lines start inside the vortices.

Li, Xin; Arnoldus, Henk F.

2013-09-01

94

Role of noncollinear magnetization for the first-order electric-dipole hyperpolarizability at the four-component Kohn-Sham density functional theory level  

NASA Astrophysics Data System (ADS)

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 3E (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.

Bast, Radovan; Saue, Trond; Henriksson, Johan; Norman, Patrick

2009-01-01

95

Space propulsion by fusion in a magnetic dipole  

Microsoft Academic Search

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

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

1991-01-01

96

Space propulsion by fusion in a magnetic dipole  

Microsoft Academic Search

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

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

1991-01-01

97

Space propulsion by fusion in a magnetic dipole  

Microsoft Academic Search

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

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

1992-01-01

98

Electricity and Magnetism  

NSDL National Science Digital Library

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

99

A superconducting dipole magnet for the UTSI MHD facility  

Microsoft Academic Search

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

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

1979-01-01

100

Dual aperture dipole magnet with second harmonic component  

SciTech Connect

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

Praeg, Walter F. (Palos Park, IL)

1985-01-01

101

Dual aperture dipole magnet with second harmonic component  

DOEpatents

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

Praeg, W.F.

1983-08-31

102

Regular and chaotic orbits near a massive magnetic dipole  

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

103

Electric dipole moment searches: reexamination of frequency shifts for particles in traps  

E-print Network

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.

Guillaume Pignol; Stephanie Roccia

2012-01-03

104

Mercury Monohalides: Suitability for Electron Electric Dipole Moment Searches  

E-print Network

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 effective electric field, and identify HgBr and HgI as interesting candidates for future electric dipole moment search experiments.

Prasannaa, V S; Abe, M; Das, B P

2014-01-01

105

Neutron Electric Dipole Moment Matt Eichenfield  

E-print Network

probe constituents' (quarks') electromagnetic properties #12;A Gentler Approach Ultra-Cold Neutron (UCN magnetization than initial magnetization #12;A Decent Experiment Needs... A good source of neutrons essential. #12;Neutron Source Pick a momentum (8.9 Angstrom Neutrons at LANSCE...necessary for 4He

Golwala, Sunil

106

The decentered magnetic dipole: a challenge for modelling  

Microsoft Academic Search

The global bipolar structure of the magnetic surface field is asymmetric for many stars, making its analytical description by an expansion of spherical harmonics problematic because of the coordinates. Landstreet (1970) proposed that the asymmetry could be understood assuming a decentered magnetic dipole in the stellar interior. Its surface field can be calculated for different arrangements inside and outside the

Ewald Gerth; Yurij V. Glagolevskij

2004-01-01

107

Origin of Spontaneous Electric Dipoles in Homonuclear Niobium Clusters  

NASA Astrophysics Data System (ADS)

Surprisingly large, spontaneous electric dipole moments recently observed in homonuclear niobium clusters below 100K (Moro et al., 2003) are explained using first-principles electronic structure calculations. The calculated moments for Nbn (n?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.

Andersen, Kristopher E.; Kumar, Vijay; Kawazoe, Yoshiyuki; Pickett, Warren E.

2004-12-01

108

Neutron Electric Dipole Moment Search with a Spallation Ultracold Neutron  

E-print Network

Neutron Electric Dipole Moment Search with a Spallation Ultracold Neutron Source at TRIUMF sources Various approaches for EDM #12;New method to make UCN Liberate neutrons by protoninduced spallation. Moderate (thermalize) in cold (20 K) D2 O. Cold neutrons then "downscatter" to near zero

Martin, Jeff

109

13B Nuclear Magnetic Dipole Moment  

Microsoft Academic Search

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

R. L. Williams; L. Madansky

1971-01-01

110

PHYSICAL REVIEW E 88, 022127 (2013) Dynamics of an electric dipole moment in a stochastic electric field  

E-print Network

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

Band, Yehuda B.

111

Origin of electric dipole moments in free niobium clusters  

NASA Astrophysics Data System (ADS)

Niobium clusters Nbn (5 <=n <=200) with surprisingly large, spontaneous electric dipole moments were recently observed in low-temperature (T < 100 K) molecular beam experiments by Moro et al. (Science 300, 1265). We address the origin of the electric dipole using first-principles electronic structure calculations for Nbn (n <=15). The calculated moments generally agree with the experimental data, in which negligible moments are found for n = 4, 10, and 15; moderate moments for n = 5--9; and large moments for n = 11--14. 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 tends to align along the axis of the largest principal moment. Charge deformation densities reveal directional, partially covalent bonds that stabilize the structural asymmetry. Classical simulations of the deflection of a cluster in a molecular beam provide evidence that the electronic dipole may persist at higher temperatures, but is masked by the rotational dynamics of the cluster.

Andersen, Kristopher; Kumar, Vijay; Pickett, Warren

2005-03-01

112

Plasma stability in a dipole magnetic field  

E-print Network

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

Simakov, Andrei N., 1974-

2001-01-01

113

Bistability between equatorial and axial dipoles during magnetic field reversals.  

PubMed

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

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

2012-06-01

114

Gravitational waves from inspiralling compact binaries with magnetic dipole moments  

E-print Network

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.

Kunihito Ioka; Keisuke Taniguchi

2000-01-13

115

New Experiment to Measure the Electron Electric Dipole Moment  

NASA Technical Reports Server (NTRS)

An electron can possess an electric dipole moment (edm) only if time reversal symmetry (T) is violated. No edm of any particle has yet been discovered. CP-violation, equivalent to T-violation by the CPT theorem, does occur in Kaon decays and can be accounted for by the standard model. However, this mechanism leads to an electron edm d(sub e) of the order of 10(exp -38) e cm, whereas the current experimental bound on d(sub e) is about 10(exp -27) e cm. However, well-motivated extensions of the standard model such as supersymmetric theories do predict that de could be as large as the current bound. In addition, CP violation in the early universe is required to explain the preponderance of matter over anti-matter, but the exact mechanism of this CP violation is unclear. For these reasons, we are undertaking a new experimental program to determine de to an improved accuracy of 10(exp -29) e cm. Our experiment will use laser-cooled, trapped Cesium atoms to measure the atomic edm d(sub Cs) that occurs if d(sub e) is not zero. In order to do this, we will measure the energy splitting between the atoms spin states in parallel electric and magnetic fields. The signature of an edm would be a linear dependence of the splitting on the electric field E due to the interaction - d(sub Cs) dot E. Our measurement will be much more sensitive than previous measurements because atoms can be stored in the trap for tens of seconds, allowing for much narrower Zeeman resonance linewidths. Also, our method eliminates the most important systematic errors, proportional to atomic velocity, which have limited previous experiments. In this presentation, we will describe the design of our new apparatus, which is presently under construction. An important feature of our experimental apparatus is that magnetic field noise will be suppressed to a very low value of the order of 1 fT/(Hz)1/2. This requires careful attention to the Johnson noise currents in the chamber, which have not been important in previous experiments. In addition we will present estimates of the limits of the various errors that we expect for our experiment.

Kittle, Melanie

2003-01-01

116

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

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

117

Improved Experimental Limit on the Electric Dipole Moment of the Neutron  

NASA Astrophysics Data System (ADS)

An experimental search for an electric dipole moment (EDM) of the neutron has been carried out at the Institut Laue-Langevin, Grenoble. Spurious signals from magnetic-field fluctuations were reduced to insignificance by the use of a cohabiting atomic-mercury magnetometer. Systematic uncertainties, including geometric-phase-induced false EDMs, have been carefully studied. The results may be interpreted as an upper limit on the neutron EDM of |dn|<2.9×10-26ecm (90% C.L.).

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

2006-09-01

118

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

PubMed

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

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

2005-12-16

119

Multiple magnetic dipole modeling and field prediction of satellites  

Microsoft Academic Search

A new method for the analysis of the dc magnetic properties of spacecraft and their subassemblies is proposed. The method, which is applicable as well to a more general variety of problems, is based on a multiple dipolar modeling of the test object; a very effective optimization procedure of the Gauss-Newton type is used to determine the dipole positions and

K. Mehlem

1978-01-01

120

The permanent and induced magnetic dipole moment of the moon  

NASA Technical Reports Server (NTRS)

Magnetic field observations with the Apollo 15 subsatellite have been used to deduce the components of both the permanent and induced lunar dipole moments in the orbital plane. The present permanent lunar magnetic dipole moment in the orbital plane is less than 1.3 times ten to the eighteenth power gauss-cu cm. Any uniformly magnetized near surface layer is therefore constrained to have a thickness-magnetization product less than 2.5 emu-cm per g. The induced moment opposes the external field, implying the existence of a substantial lunar ionosphere with a permeability between 0.63 and 0.85. Combining this with recent measures of the ratio of the relative field strength at the ALSEP and Explorer 35 magnetometers indicates that the global lunar permeability relative to the plasma in the geomagnetic tail lobes is between 1.008 and 1.03.

Russell, C. T.; Coleman, P. J., Jr.; Lichtenstein, B. R.; Schubert, G.

1974-01-01

121

Effects of MHD slow shocks propagating along magnetic flux tubes in a dipole magnetic field  

Microsoft Academic Search

Variations of the plasma pressure in a magnetic flux tube can produce MHD waves evolving into shocks. In the case of a low plasma beta, plasma pressure pulses in the magnetic flux tube generate MHD slow shocks propagating along the tube. For converging magnetic field lines, such as in a dipole magnetic field, the cross section of the magnetic flux

N. V. Erkaev; V. A. Shaidurov; V. S. Semenov; H. K. Biernat

2002-01-01

122

Development of Cellular Magnetic Dipoles in Magnetotactic Bacteria  

Microsoft Academic Search

Magnetotactic bacteria benefit from their ability to form cellular magnetic dipoles by assembling stable single-domain ferromagnetic particles in chains as a means to navigate along Earth's magnetic field lines on their way to favorable habitats. We studied the assembly of nanosized membrane-encapsulated magnetite particles (magnetosomes) by ferromagnetic resonance spectroscopy using Magnetospirillum gryphiswaldense cultured in a time-resolved experimental setting. The spectroscopic data

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

2010-01-01

123

A cosmological lower bound on the neutron electric dipole moment  

Microsoft Academic Search

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

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

1981-01-01

124

Electric Dipole Moment in the Split Supersymmetry Models  

E-print Network

We study an important contribution to the electric dipole moment (EDM) of the electron (or quarks) at the two-loop level due to the $W$-EDM in the recently proposed scenario of split supersymmetry. This contribution is independent of the Higgs mass, and it can enhance the previous estimation of the electron (neutron) EDM by $20-50%$ ($40-90%$). Our formula is new in its analytical form.

Darwin Chang; We-Fu Chang; Wai-Yee Keung

2005-03-06

125

Constraining the neutrino magnetic dipole moment from white dwarf pulsations  

NASA Astrophysics Data System (ADS)

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. We employ state-of-the-art evolutionary and pulsational codes which allow us to perform a detailed asteroseismological period fit based on fully DB white dwarf evolutionary sequences. Plasmon neutrino emission is the dominant cooling mechanism for this class of hot pulsating white dwarfs, and so it is the main contributor to the rate of change of period with time (Pi dot) for the DBV class. Thus, the inclusion of an anomalous neutrino emission through a non-vanishing magnetic dipole moment in these sequences notably influences the evolutionary timescales, and also the expected pulsational properties of the DBV stars. By comparing the theoretical Pi dot value 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 with an upper limit of ?? lesssim 10-11 ?B. This bound 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.

Córsico, A. H.; Althaus, L. G.; Miller Bertolami, M. M.; Kepler, S. O.; García-Berro, E.

2014-08-01

126

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

SciTech Connect

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

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

1997-10-01

127

Rheometry Experiment of Electric Dipole Antennas Onboard GEOTAIL  

NASA Astrophysics Data System (ADS)

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

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

2001-12-01

128

Magnetic Susceptibility Anisotropy, Molecular Quadrupole Moment, and the Sign of the Electric Dipole Moment in OCCCS: A High-Resolution Microwave Fourier Transform Study Combined with IGLO Calculations  

Microsoft Academic Search

The molecular Zeeman effects of 16O12C12C12C32S and 16O12C12C12C34S have been observed by microwave Fourier transform spectroscopy in magnetic fields up to 20 000 G. The magnetic susceptibility anisotropy of the OCCCS molecule is xi-xi? = -18.740(6) 10-6 erg G-2 mol-1. The molecular g? values for the two isotopomers obtained from the J = 3 --> J = 2 transitions are

F. Holland; U. Fleischer; A. Klesing; D. H. Sutter

1993-01-01

129

Capacitive Stress Gauges in Model Dipole Magnets  

E-print Network

of weighted capacitance. Though the offsets to capacitance due to a heating cycle may be unpredictable, convergence of weighted capacitance values over several heat cycles can certainly reduce error in model magnet stress measurements....

Ragland, R. Blake

2009-06-09

130

Transmission of electric dipole radiation through an interface  

NASA Astrophysics Data System (ADS)

We consider the transmission of electric dipole radiation through an interface between two dielectrics, for the case of a vertical dipole. Energy flows along the field lines of the Poynting vector, and in the optical near field these field lines are curves (as opposed to optical rays). When the radiation passes through the interface into a thicker medium, the field lines bend to the normal (as rays do), but the transmission angle is not related to the angle of incidence. The redirection of the radiation at the interface is determined by the angle dependence of the transmission coefficient. This near-field redistribution is responsible for the far-field angular power pattern. When the transmission medium is thinner than the embedding medium of the dipole, some energy flows back and forth through the interface in an oscillating fashion. In each area where field lines dip below the interface, an optical vortex appears just above the interface. The centers of these vortices are concentric singular circles around the dipole axis.

Arnoldus, Henk F.; Berg, Matthew J.; Li, Xin

2014-02-01

131

Electrical Integrity Tests during Production of the LHC Dipoles  

E-print Network

For the LHC dipoles, mandatory electrical integrity tests are performed to qualify the cold mass (CM) at four production stages: individual pole, collared coil, CM before end cover welding and final CM. A description of the measurement equipment and its recent development are presented. After passing the demands set out in the specification, the results of the tests are transmitted to CERN where they are further analyzed. The paper presents the most important results of these measurements. We also report a review of the electrical non-conformities encountered e.g. interturn shorts and quench heater failure, their diagnostic and the cures.

deRijk, G; Cornelis, M; Fessia, P; Miles, J; Modena, M; Molinari, G; Rinn, J; Savary, F; Vlogaert, J

2006-01-01

132

Origin of the electric dipole moment in niobium clusters  

NASA Astrophysics Data System (ADS)

Evidence of a permanent electric dipole moment in free niobium clusters containing from 5 to over 100 atoms at temperatures below 100 K has been recently reported by Moro. et. al. (Science 300, 1265). The observed moments, on the order of 2 debye, were measured by deflecting a cryogenically cooled cluster beam through an inhomogeneous electric field, and were found to be significantly larger than the moments for clusters of other elements. However, the microscopic origin of the dipole moment is still unknown, and appears distinct from the ferroelectricty of crystalline compounds. Here we present an analysis of the dielectric properties of niobium clusters from first-principles density-functional calculations. The magnitude of the calculated moments generally agree with experiment within the studied size range of 2-18 atoms. The contribution to the total moment from specific electronic states is presented for clusters containing 9-15 atoms. In these, most of the moment is contributed by valence states, and for clusters with an odd number of electrons, the dipole is predominately associated with a single spin-polarization.

Andersen, K. E.; Pickett, W. E.; Kumar, V.; Kawazoe, Y.

2004-03-01

133

Full length SSC R and D dipole magnet test results  

SciTech Connect

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.

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

134

Magnetic dipole moment determination by near-field analysis  

NASA Technical Reports Server (NTRS)

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

Eichhorn, W. L.

1972-01-01

135

Isospin properties of electric dipole excitations in 48Ca  

E-print Network

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 (\\alpha,\\alpha'\\gamma) experiment at E_{\\alpha}=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.

V. Derya; D. Savran; J. Endres; M. N. Harakeh; H. Hergert; J. H. Kelley; P. Papakonstantinou; N. Pietralla; V. Yu. Ponomarev; R. Roth; G. Rusev; A. P. Tonchev; W. Tornow; H. J. Wörtche; A. Zilges

2014-02-03

136

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

SciTech Connect

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

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

2010-02-15

137

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

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

138

Performance of dipole magnets in helium II  

SciTech Connect

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.

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

1981-03-01

139

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

140

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

NASA Astrophysics Data System (ADS)

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

Lin, F.; Malitsky, N. D.; Luccio, A. U.; Morse, W. M.; Semertzidis, Y. K.; Onderwater, C. J. G.; Orlov, Y. F.

2009-08-01

141

Dipole corrector magnets for the LBNE beam line  

SciTech Connect

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

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

2011-03-01

142

Magnetic field measurements of printed-circuit quadrupoles and dipoles  

Microsoft Academic Search

Printed-Circuit (PC) quadrupoles and dipoles have been designed and developed for focusing and bending a space-charge dominated electron beam in the University of Maryland Electron Ring (UMER), currently under development. Due to the rather small aspect ratio (length\\/diameter <1) of the magnets, the field quality, especially the nonlinear fringe field, has been a concern for the success of the UMER

W. W. Zhang; S. Bernal; P. Chin; R. Kishek; M. Reiser; M. Venturini; J. G. Wang; V. Yun

1999-01-01

143

Nuclear electric dipole moment of three-body system  

E-print Network

Nuclear electric dipole moments of $^{3}He$ and $^{3}H$ are calculated using Time Reversal Invariance Violating (TRIV) potentials based on the meson exchange theory, as well as the ones derived by using pionless and pionful effective field theories, with nuclear wave functions obtained by solving Faddeev equations in configuration space for the complete Hamiltonians comprising both TRIV and realistic strong interactions. The obtained results are compared with the previous calculations of $^{3}He$ EDM and with time reversal invariance violating effects in neutron-deuteron scattering.

Young-Ho Song; Rimantas Lazauskas; Vladimir Gudkov

2012-11-15

144

Nuclear electric dipole moment of three-body system  

E-print Network

Nuclear electric dipole moments of $^{3}He$ and $^{3}H$ are calculated using Time Reversal Invariance Violating (TRIV) potentials based on the meson exchange theory, as well as the ones derived by using pionless and pionful effective field theories, with nuclear wave functions obtained by solving Faddeev equations in configuration space for the complete Hamiltonians comprising both TRIV and realistic strong interactions. The obtained results are compared with the previous calculations of $^{3}He$ EDM and with time reversal invariance violating effects in neutron-deuteron scattering.

Song, Young-Ho; Gudkov, Vladimir

2012-01-01

145

The permanent electric dipole moment of chromium monoxide  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

146

Magnetic dipole sequences in Rb83  

NASA Astrophysics Data System (ADS)

High-spin states in Rb83 were populated in the reaction B11+Ge76 at beam energies of 45 and 50 MeV. ? rays were detected with the spectrometer GASP. The level scheme of Rb83 was extended up to 13.9 MeV. Mean lifetimes of 23 levels were determined using the Doppler-shift-attenuation method. Among the bands newly established is a sequence comprising intense M1 transitions and crossover E2 transitions. This sequence turns out to be irregular and thus shows that magnetic rotation as observed in the neighboring odd-odd isotopes is not realized in this odd-even nuclide. Excited states in Rb83 were interpreted in terms of the shell model using the model space ?(0f5/2,1p3/2,1p1/2,0g9/2)?(1p1/2,0g9/2). The configurations predicted for the negative-parity M1 sequence reproduce the M1 transition strengths fairly well.

Schwengner, R.; Rainovski, G.; Schnare, H.; Wagner, A.; Frauendorf, S.; Dönau, F.; Jungclaus, A.; Hausmann, M.; Yordanov, O.; Lieb, K. P.; Napoli, D. R.; de Angelis, G.; Axiotis, M.; Marginean, N.; Brandolini, F.; Alvarez, C. Rossi

2009-10-01

147

New Experimental Limit on the Electric Dipole Moment of the Electron in a Paramagnetic Insulator  

E-print Network

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 $(-5.57 \\pm 7.98 \\pm 0.12)\\times10^{-25}$e$\\cdot$cm with 5 days of data averaging.

Y. J. Kim; C. -Y. Liu; S. K. Lamoreaux; G. Visser; B. Kunkler; A. V. Matlashov; B. Kunkler

2011-04-22

148

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

NASA Astrophysics Data System (ADS)

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

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

2011-09-01

149

Progress Toward Measurement of the Electron's Electric Dipole Moment Using the PbF Molecule  

NASA Astrophysics Data System (ADS)

The PbF molecule is particularly suited to a search for the electron's electric dipole moment (e-EDM.) In addition to its sensitivity to an e-EDM, its ^2?1/2 ground state provides for a small magnetic moment. Furthermore, this small magnetic moment vanishes at a magic value of electric field. This vanishing point has an experimentally observable signature: When a beam of suitably aligned ground state PbF molecules is allowed to traverse a region of electric and magnetic fields, the polarization is conserved when the electric field matches this magic value. By measuring the (molecular-frame)magnitude of this magic electric field for the case that the electric field is parallel or antiparallel to the magnetic field, sensitivity to the e-EDM is achieved. Progress toward this measurement, including the development of a continuous molecular beam source of PbF, characterization of the electronic, rotational, and hyperfine structure of the molecule, the achievement of an ultra-sensitive continuous ionization detection scheme, and the construction of a Ramsey- resonance machine are briefly summarized.

Shafer-Ray, Neil; McRaven, Christopher; Sivakumar, Poopalasingam; Rupasinghe, Milinda

2009-05-01

150

Search for a permanent electric dipole moment of the mercury atom  

NASA Astrophysics Data System (ADS)

There has been exciting progress in recent years in the search for a spin-aligned electric dipole moment (EDM) of atoms, molecules, and the neutron. Although such a time-reversal violating dipole has not yet been detected, highly touted theories of possible new physics, such as Supersymmetry, predict the existence of EDMs within reach of modern experiments. In 2001 our group published a precise limit on the EDM of the ^199Hg atom: |d(Hg)|< 2.1 x 10-28 e cm. To further refine these measurements, we switched from two to a stack of four nuclear-spin-polarized Hg vapor cells. Two lie in parallel magnetic and anti-parallel electric fields, resulting in EDM-sensitive spin precession; the other two cells, at zero electric field, serve to cancel magnetic gradient noise and limit systematics due to magnetic impurities or leakage currents. To date, the statistical uncertainty for the new EDM data is1.7 x 10-29 e cm. Constraining systematics to similar levels will thus yield an order of magnitude improvement over our previous measurement. The talk will highlight recent work and show our current results. This research is supported by NSF Grant PHY 0457320.

Fortson, Norval

2008-04-01

151

The Electric Dipole Moment of Iridium Monosilicide, IrSi  

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

152

Probing electric and magnetic vacuum fluctuations with quantum dots  

E-print Network

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

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

2014-04-04

153

Probing electric and magnetic vacuum fluctuations with quantum dots  

E-print Network

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

Tighineanu, Petru; Sørensen, Anders Søndberg; Stobbe, Søren; Lodahl, Peter

2014-01-01

154

Probing Electric and Magnetic Vacuum Fluctuations with Quantum Dots  

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

155

Probing electric and magnetic vacuum fluctuations with quantum dots.  

PubMed

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

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

2014-07-25

156

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

ERIC Educational Resources Information Center

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

Smith, Glenn S.

2011-01-01

157

Electric Dipole Polarizabilities of Hydrogen and Helium Isotopes  

E-print Network

The electric dipole polarizabilities of $^3$H, $^3$He, and $^4$He are calculated directly using the Schr\\"odinger equation with the latest generation of two- and three-nucleon interactions. These polarizabilities 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 $^4$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.

I. Stetcu; S. Quaglioni; J. L. Friar; A. C. Hayes; P. Navrátil

2009-04-23

158

Electric dipole polarizabilities of hydrogen and helium isotopes  

SciTech Connect

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

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

2009-01-01

159

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

NASA Astrophysics Data System (ADS)

The search for particle electric dipole moments (EDM’s) 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 v?×E? field with magnetic field gradients which is often referred to as the geometric phase effect [E. D. Commins, Am. J. Phys. 59, 1077 (1991); J. M. Pendlebury , Phys. Rev. A 70, 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 autocorrelation function which determines the velocity-position correlation function which in turn determines the behavior of the frequency shift [S. K. Lamoreaux and R. Golub, Phys. Rev A 71, 032104 (2005)] and show how it depends on the operating conditions of the experiment. We also discuss some additional issues.

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

2006-11-01

160

Multiconfiguration Dirac-Hartree-Fock calculations of atomic electric dipole moments of Ra225, Hg199, and Yb171  

NASA Astrophysics Data System (ADS)

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.

RadžiÅ«tÄ--, Laima; Gaigalas, Gediminas; Jönsson, Per; Biero?, Jacek

2014-07-01

161

Anthranilamides as bioinspired molecular electrets: experimental evidence for a permanent ground-state electric dipole moment.  

PubMed

As electrostatic equivalents of magnets, organic electrets offer unparalleled properties for impacting energy conversion and electronic applications. While biological systems have evolved to efficiently utilize protein ?-helices as molecular electrets, the synthetic counterparts of these conjugates still remain largely unexplored. This paper describes a study of the electronic properties of anthranilamide oligomers, which proved to be electrets based on their intrinsic dipole moments as evident from their spectral and dielectric properties. NMR studies provided the means for estimating the direction of the intrinsic electric dipoles of these conjugates. This study sets the foundation for the development of a class of organic materials that are de novo designed from biomolecular motifs and possess unexplored electronic properties. PMID:23270467

Xia, Bing; Bao, Duoduo; Upadhyayula, Srigokul; Jones, Guilford; Vullev, Valentine I

2013-03-01

162

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

E-print Network

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

Adriana Pálffy; Jörg Evers; Christoph H. Keitel

2007-10-31

163

Lepton Dipole Moments  

E-print Network

From the famous experiments of Stern and Gerlach to the present, measurements of magnetic dipole moments, and searches for electric dipole moments of ``elementary'' particles have played a major role in our understanding of sub-atomic physics. In this talk I discuss the progress on measurements and theory of the magnetic dipole moments of the electron and muon. I also discuss a new proposal to search for a permanent electric dipole moment (EDM) of the muon and put it into the more general context of other EDM searches.

B. Lee Roberts

2003-09-02

164

Improved Experimental Limit on the Electric Dipole Moment of the Neutron  

SciTech Connect

An experimental search for an electric dipole moment (EDM) of the neutron has been carried out at the Institut Laue-Langevin, Grenoble. Spurious signals from magnetic-field fluctuations were reduced to insignificance by the use of a cohabiting atomic-mercury magnetometer. Systematic uncertainties, including geometric-phase-induced false EDMs, have been carefully studied. The results may be interpreted as an upper limit on the neutron EDM of vertical bar d{sub n} vertical bar <2.9x10{sup -26}e cm (90% C.L.)

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

2006-09-29

165

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

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

166

Improved experimental limit on the electric dipole moment of the neutron.  

PubMed

An experimental search for an electric dipole moment (EDM) of the neutron has been carried out at the Institut Laue-Langevin, Grenoble. Spurious signals from magnetic-field fluctuations were reduced to insignificance by the use of a cohabiting atomic-mercury magnetometer. Systematic uncertainties, including geometric-phase-induced false EDMs, have been carefully studied. The results may be interpreted as an upper limit on the neutron EDM of |d(n)|< 2.9 x 10(-26)e cm (90% C.L.). PMID:17026025

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

2006-09-29

167

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

Microsoft Academic Search

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

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

2010-01-01

168

Analysis of Exploding Plasma Behavior in a Dipole Magnetic Field  

NASA Astrophysics Data System (ADS)

Numerical analyses on plasma behaviors in a dipole magnetic field are performed using a three-dimensional (3D) hybrid code. Results are compared with the experimental data and magnetohydrodynamics (MHD) analysis. Dependence of plasma expansion on initial plasma energy and location are discussed by temporal evolutions of plasma position and magnetic field strength. An overall good agreement in the expansion behavior of plasmas among these results is found. The asymmetrical shape of the expanding plasma in the cross-field direction is also noticed, and the reason for this is discussed. For future engineering applications, these results will be useful in designing an optimal configuration of the magnetic thrust chamber for laser fusion rockets, and for studying the effective explosive methods for protecting the earth from collisions by asteroids or comets.

Muranaka, Takanobu; Uchimura, Hideyuki; Nakashima, Hideki; Zakharov, Yuri P.; Nikitin, Sergey A.; Ponomarenko, Arnold G.

2001-02-01

169

Progress towards an electric dipole moment measurement in radium-225  

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

170

NMR frequency and magnetic dipole moment of (3)He nucleus.  

PubMed

We present new gas-phase NMR spectra which relate the resonance frequency of (3)He nucleus to the resonance frequency of the proton in tetramethylsilane (TMS). We discuss the dependence of (3)He resonance frequency on the density of the solvent gas, and we consider in detail the absolute shielding scales of both nuclei. Finally, we analyse the accuracy of the results, using the relationship between the resonance frequencies, absolute shielding constants and magnetic dipole moments of (1)H and (3)He nuclei. PMID:18442939

Jackowski, Karol; Jaszu?ski, Micha?; Kamie?ski, Bohdan; Wilczek, Marcin

2008-07-01

171

Magnetic dipole radiation tailored by substrates: numerical investigation.  

PubMed

Nanoparticles of high refractive index materials can possess strong magnetic polarizabilities and give rise to artificial magnetism in the optical spectral range. While the response of individual dielectric or metal spherical particles can be described analytically via multipole decomposition in the Mie series, the influence of substrates, in many cases present in experimental observations, requires different approaches. Here, the comprehensive numerical studies of the influence of a substrate on the spectral response of high-index dielectric nanoparticles were performed. In particular, glass, perfect electric conductor, gold, and hyperbolic metamaterial substrates were investigated. Optical properties of nanoparticles were characterized via scattering cross-section spectra, electric field profiles, and induced electric and magnetic moments. The presence of substrates was shown to have significant impact on particle's magnetic resonances and resonant scattering cross-sections. Variation of substrate material provides an additional degree of freedom in tailoring optical properties of magnetic multipoles, important in many applications. PMID:24921770

Markovich, D L; Ginzburg, P; Samusev, A K; Belov, P A; Zayats, A V

2014-05-01

172

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

SciTech Connect

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

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

2001-06-15

173

CKM benchmarks for electron electric dipole moment experiments  

NASA Astrophysics Data System (ADS)

All current experiments searching for an electron electric dipole moment (EDM) de are performed with atoms and diatomic molecules. Motivated by significant recent progress in searches for an EDM-type signal in diatomic molecules with an uncompensated electron spin, we provide an estimate for the expected signal in the Standard Model due to the Cabibbo-Kobayashi-Maskawa (CKM) phase. We find that the main contribution originates from the effective electron-nucleon operator e¯i?5eN¯N, induced by a combination of weak and electromagnetic interactions at O(GF2?2), and not by the CKM-induced electron EDM itself. When the resulting atomic P ,T-odd mixing is interpreted as an equivalent electron EDM, this estimate leads to the benchmark deequiv(CKM)˜10-38 ecm.

Pospelov, Maxim; Ritz, Adam

2014-03-01

174

Even larger contributions to the neutron electric dipole moment  

NASA Astrophysics Data System (ADS)

Constraints on theories of CP-violation, from limits on the neutron electric dipole moment, and mediated by a CP-odd three-gluon operator, are current best sellers. We introduce novel CP-odd operators involving one photon and three gluons. We find that effects mediated by these operators result on bounds on supersymmetry an order of magnitude more stringent than earlier results: they are the tightest known bounds. For left-right models we derive richer limits than previously found. We also recalculate the anomalous dimensions of the three-gluon operator and find them to be minus those originally used; this weakens considerably its strictures on theory, though it still mediates the dominant effect in multi-Higgs models.

de Rújula, A.; Gavela, M. B.; Pène, O.; Vegas, F. J.

1990-08-01

175

CP violation in beta decay and electric dipole moments  

NASA Astrophysics Data System (ADS)

The T-odd correlation coefficient D in nuclear ? decay probes CP violation in many theories beyond the standard model. We provide an analysis for how large D can be in light of constraints from electric dipole moment (EDM) searches. We argue that the neutron EDM dn currently provides the strongest constraint on D, which is 10-103 times stronger than current direct limits on D (depending on the model). In particular, contributions to D in leptoquark models (previously regarded as “EDM safe”) are more constrained than previously thought. Bounds on D can be weakened only by fine-tuned cancellations or if theoretical uncertainties are larger than estimated in dn. We also study implications for D from mercury and deuteron EDMs.

Ng, John; Tulin, Sean

2012-02-01

176

Nuclear Electric Dipole Moments in Chiral Effective Field Theory  

E-print Network

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

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

2014-01-01

177

Electroweak baryogenesis, electric dipole moments, and Higgs diphoton decays  

NASA Astrophysics Data System (ADS)

We study the viability of electroweak baryogenesis in a two Higgs doublet model scenario augmented by vector-like, electroweakly interacting fermions. Considering a limited, but illustrative region of the model parameter space, we obtain the observed cosmic baryon asymmetry while satisfying present constraints from the non-observation of the permanent electric dipole moment (EDM) of the electron and the combined ATLAS and CMS result for the Higgs boson diphoton decay rate. The observation of a non-zero electron EDM in a next generation experiment and/or the observation of an excess (over the Standard Model) of Higgs to diphoton events with the 14 TeV LHC run or a future e + e - collider would be consistent with generation of the observed baryon asymmetry in this scenario.

Chao, Wei; Ramsey-Musolf, Michael J.

2014-10-01

178

Two modes of wave propagation manifested in vertical electric dipole radiation over a sphere  

Microsoft Academic Search

The radiation of a vertical electric dipole over an electrically homogeneous sphere is considered anew, starting with a novel mathematical formulation. Both the dipole and the point of observation are assumed to lie on the spherical interface. The analysis is valid for a sphere whose radius is much larger than the wavelength in the outside region. Contributions to the value

Vassilios A. Houdzoumis; Vassilios A

2000-01-01

179

Production of Austenitic Steel for the LHC Superconducting Dipole Magnets  

E-print Network

The austenitic-steel collars are an important component of the LHC dipole magnets, operating at cryogenic temperature under high mechanical stress. The required steel, known as YUS 130S, has been specifically developed for this application by Nippon Steel Corporation (NSC), who was awarded a CERN contract in 1999 for the supply of 11 500 tonnes. In 2005 - after six years of work - the contract is being successfully completed, with final production being ensured since October 2003 by Nippon Steel & Sumikin Stainless Steel Corporation (NSSC). The paper describes the steel properties, its manufacturing and quality control process, organization of production, logistics and contract follow-up. Extensive statistics have been collected relating to mechanical, physical and technological parameters. Specific attention is dedicated to measurements of magnetic permeability performed at cryogenic temperatures by CERN, the equipment used and statistical results. Reference is also made to the resulting precision of the...

Bertinelli, F; Komori, T; Peiro, G; Rossi, L

2006-01-01

180

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

SciTech Connect

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

Denne, B.; Hinnov, E.

1984-04-01

181

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

SciTech Connect

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

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

2010-01-15

182

Cross Correlation between the Dipole-Dipole Interaction and the Curie Spin Relaxation: The Effect of Anisotropic Magnetic Susceptibility  

NASA Astrophysics Data System (ADS)

Cross-correlated relaxation caused by the interference of nuclear dipole-dipole interaction and the Curie spin relaxation (DD-CSR cross relaxation) is generalized to treat the case of anisotropic magnetic susceptibility, including the important case where the latter originates from zero-field splitting. It is shown that the phenomenon of DD-CSR cross relaxation is absolutely general and to be expected under any electronic configuration. The results of the generalization are presented for a model system, and the consequences for paramagnetic metalloproteins are illustrated with an example of cerium(III)-substituted calbindin. The effects of the magnetic anisotropy are found to be substantial.

Bertini, Ivano; Kowalewski, Jozef; Luchinat, Claudio; Parigi, Giacomo

2001-09-01

183

Electric and magnetic response to the continuum for A=7 isobars in a dicluster model  

E-print Network

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.

A. Mason; R. Chatterjee; L. Fortunato; A. Vitturi

2008-06-25

184

Magnets and Electricity.  

ERIC Educational Resources Information Center

Describes a kit designed as a leisure time activity for teenagers and adults who have had little previous experience of magnetism and electricity. The kit may be useful for homework, small group work, or as a training course for nonscientist science teachers. (PR)

Ward, Alan

1993-01-01

185

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

SciTech Connect

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H{sup 3}?{sub 1} state of ThO molecule was proposed and now prepared by the ACME Collaboration [ http://www.electronedm.org ]. To interpret the experiment in terms of eEDM and dimensionless constant k{sub T,} {sub P} characterizing the strength of the T,P-odd pseudoscalar–scalar electron–nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, E{sub eff}, and a parameter of the T,P-odd pseudoscalar–scalar interaction, W{sub T,} {sub P}, in ThO is required. We report our results for E{sub eff} (84 GV/cm) and W{sub T,} {sub P} (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H{sup 3}?{sub 1} ? X{sup 1}?{sup +} transition energy, which can serve as a measure of reliability of the obtained E{sub eff} and W{sub T,} {sub P} values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the ?-doublets of H{sup 3}?{sub 1}.

Skripnikov, L. V., E-mail: leonidos239@gmail.com; Petrov, A. N.; Titov, A. V. [Federal State Budgetary Institute “Petersburg Nuclear Physics Institute,” Gatchina, Leningrad district 188300 (Russian Federation) [Federal State Budgetary Institute “Petersburg Nuclear Physics Institute,” Gatchina, Leningrad district 188300 (Russian Federation); Department of Physics, Saint Petersburg State University, Saint Petersburg, Petrodvoretz 198904 (Russian Federation)

2013-12-14

186

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

187

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

NASA Astrophysics Data System (ADS)

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

Fang, Fang

188

Neutron electric dipole moment measurement with a buffer gas comagnetometer  

NASA Astrophysics Data System (ADS)

A neutron EDM measurement with a comagnetometer is discussed. For magnetometry, polarized xenon atoms are injected into a cylindrical cell where a cylindrically symmetric magnetic field and an electric field are applied for the EDM measurement. The geometric phase effect (GPE), which originates from particle motion in a magnetic field gradient, is analyzed in terms of the Dyson series. The motion of the xenon atom is largely suppressed because of a small mean free path. The field gradient is controlled by means of NMR measurements, where the false effect of Earth's rotation is removed. As a result, the GPE is reduced below 10-28e cm.

Masuda, Yasuhiro; Asahi, Koichiro; Hatanaka, Kichiji; Jeong, Sun-Chan; Kawasaki, Shinsuke; Matsumiya, Ryohei; Matsuta, Kensaku; Mihara, Mototsugu; Watanabe, Yutaka

2012-03-01

189

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

E-print Network

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

DeLauter, Jonathan

190

EPICS Slow Controls System in the Search for a Neutron Electric Dipole Moment  

NASA Astrophysics Data System (ADS)

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.

Taylor, Courtney

2006-10-01

191

Electric Dipolar Kondo Effect Emerging from a Vibrating Magnetic Ion  

NASA Astrophysics Data System (ADS)

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

Hotta, Takashi; Ueda, Kazuo

2012-06-01

192

Adsorption of hydrophobin on different self-assembled monolayers: the role of the hydrophobic dipole and the electric dipole.  

PubMed

In this work, the adsorptions of hydrophobin (HFBI) on four different self-assembled monolayers (SAMs) (i.e., CH3-SAM, OH-SAM, COOH-SAM, and NH2-SAM) were investigated by parallel tempering Monte Carlo and molecular dynamics simulations. Simulation results indicate that the orientation of HFBI adsorbed on neutral surfaces is dominated by a hydrophobic dipole. HFBI adsorbs on the hydrophobic CH3-SAM through its hydrophobic patch and adopts a nearly vertical hydrophobic dipole relative to the surface, while it is nearly horizontal when adsorbed on the hydrophilic OH-SAM. For charged SAM surfaces, HFBI adopts a nearly vertical electric dipole relative to the surface. HFBI has the narrowest orientation distribution on the CH3-SAM, and thus can form an ordered monolayer and reverse the wettability of the surface. For HFBI adsorption on charged SAMs, the adsorption strength weakens as the surface charge density increases. Compared with those on other SAMs, a larger area of the hydrophobic patch is exposed to the solution when HFBI adsorbs on the NH2-SAM. This leads to an increase of the hydrophobicity of the surface, which is consistent with the experimental results. The binding of HFBI to the CH3-SAM is mainly through hydrophobic interactions, while it is mediated through a hydration water layer near the surface for the OH-SAM. For the charged SAM surfaces, the adsorption is mainly induced by electrostatic interactions between the charged surfaces and the oppositely charged residues. The effect of a hydrophobic dipole on protein adsorption onto hydrophobic surfaces is similar to that of an electric dipole for charged surfaces. Therefore, the hydrophobic dipole may be applied to predict the probable orientations of protein adsorbed on hydrophobic surfaces. PMID:25185838

Peng, Chunwang; Liu, Jie; Zhao, Daohui; Zhou, Jian

2014-09-30

193

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

SciTech Connect

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

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

1993-04-01

194

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

SciTech Connect

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

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

1993-04-01

195

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

E-print Network

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

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

2013-05-31

196

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

E-print Network

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

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

2013-01-01

197

Nuclear electric dipole moment of three-body systems  

NASA Astrophysics Data System (ADS)

Background: The existence of the electric dipole moment (EDM) of stable nuclei would be a direct evidence of the time reversal invariance violation (TRIV). Therefore, its measurement could be considered as a complement to the search for neutron and atomic EDMs.Purpose: To clarify theoretical issues related to calculations of EDMs in many-body systems we calculated the EDMs of the simplest nuclei.Method: For calculations of three-nucleon systems EDMs we used TRIV potentials based on the meson exchange theory, as well as the ones derived by using effective field theories (EFT) with and without explicit pions. Nuclear wave functions were obtained by solving Faddeev equations in configuration space for the complete Hamiltonians comprising both TRIV and realistic strong interactions.Results: The expressions for EDMs of 3He and 3H are given in terms of meson exchange couplings and low energy constants of EFT potentials.Conclusions: The obtained results are compared with the previous calculations of 3He EDM and with time reversal invariance violating effects in neutron-deuteron scattering. The model dependence on strong interactions is discussed.

Song, Young-Ho; Lazauskas, Rimantas; Gudkov, Vladimir

2013-01-01

198

Search for the Electric Dipole Moment of RADIUM-225  

NASA Astrophysics Data System (ADS)

The nuclear Schiff moment and its resulting atomic electric dipole moment (EDM) are signatures of time-reversal and parity violation. They represent an important window onto physics beyond the Standard Model. We are developing a next generation experiment to search for the Schiff moment and EDM of 225Ra (t1/2 = 15 d) based on laser-cooled and -trapped radium atoms. Due to octupole deformation of the nucleus, 225Ra is predicted to be 2-3 orders of magnitude more sensitive to T-violating interactions than 199Hg (stable), which currently sets the most stringent limits in the nuclear sector. At present, 225Ra samples at the level of a few mCi (~ 1014 atoms) are available from the decay of the long-lived 229Th in stock. A future ISOL facility driven by a high-intensity accelerator could deliver 4-5 orders of magnitude more 225Ra. It holds the potential to further improve the EDM search sensitivity.

Holt, Roy J.; Lu, Zheng-Tian; Mueller, Peter

2010-06-01

199

Atomic electric dipole moments: The Schiff theorem and its corrections  

SciTech Connect

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

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

2007-09-15

200

Theoretical Prediction and Impact of Fundamental Electric Dipole Moments  

E-print Network

The predicted Standard Model (SM) electric dipole moments (EDMs) of electrons and quarks are tiny, providing an important window to observe new physics. Theories beyond the SM typically allow relatively large EDMs. The EDMs depend on the relative phases of terms in the effective Lagrangian of the extended theory, which are generally unknown. Underlying theories, such as string/M-theories compactified to four dimensions, could predict the phases and thus EDMs in the resulting supersymmetric (SUSY) theory. Earlier one of us, with collaborators, made such a prediction and found, unexpectedly, that the phases were predicted to be zero at tree level in the theory at the unification or string scale $\\sim\\mathcal{O}(10^{16}$ GeV). Electroweak (EW) scale EDMs still arise via running from the high scale, and depend only on the SM Yukawa couplings that also give the CKM phase. Here we extend the earlier work by studying the dependence of the low scale EDMs on the constrained but not fully known fundamental Yukawa coupl...

Ellis, Sebastian A R

2014-01-01

201

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

NASA Astrophysics Data System (ADS)

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

Kim, Young Jin; Liu, Chen-Yu

2011-04-01

202

High Voltage Breakdown and SQUID Performance for the Neutron Electric Dipole Moment Experiment  

NASA Astrophysics Data System (ADS)

A new search for a permanent electric dipole moment (EDM) of the neutron is underway at the Oak Ridge Spallation Neutron Source. A non-zero EDM would be a signal of time reversal symmetry violation and improve our understanding of the matter-antimatter asymmetry of the universe. The experiment will use a Superconducting Quantum Interference Device (SQUID) to infer the precession of ultracold neutrons held in a superfluid helium bath, in the presence of applied electric and magnetic fields. The experiment's sensitivity is proportional to the applied electric field. Neither the maximum practical size of the electric field nor the behavior of SQUIDs in proximity to this field are presently understood. Therefore we have constructed a small prototype (to decrease the cool-down time) to verify that SQUIDs can function in a high voltage environment and when exposed to RF interference. Another goal is to determine what characteristics allow us to maximize the electric field without breakdown. To do this we measure the breakdown voltage in both normal and superfluid helium at a variety of temperatures and (more uniquely) at different pressures, as well as test a variety of electrode materials.

Huffer, Craig; Liu, Chen-Yu; Long, Josh; Karcz, Maciej

2007-10-01

203

Regular and Chaotic Motion in General Relativity: The Case of a Massive Magnetic Dipole  

E-print Network

Circular motion of particles, dust grains and fluids in the vicinity of compact objects has been investigated as a model for accretion of gaseous and dusty environment. Here we further discuss, within the framework of general relativity, figures of equilibrium of matter under the influence of combined gravitational and large-scale magnetic fields, assuming that the accreted material acquires a small electric charge due to interplay of plasma processes and photoionization. In particular, we employ an exact solution describing the massive magnetic dipole and we identify the regions of stable motion. We also investigate situations when the particle dynamics exhibits the onset of chaos. In order to characterize the measure of chaoticness we employ techniques of Poincar\\'e surfaces of section and of recurrence plots.

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

2014-07-03

204

Regular and Chaotic Motion in General Relativity: The Case of a Massive Magnetic Dipole  

E-print Network

Circular motion of particles, dust grains and fluids in the vicinity of compact objects has been investigated as a model for accretion of gaseous and dusty environment. Here we further discuss, within the framework of general relativity, figures of equilibrium of matter under the influence of combined gravitational and large-scale magnetic fields, assuming that the accreted material acquires a small electric charge due to interplay of plasma processes and photoionization. In particular, we employ an exact solution describing the massive magnetic dipole and we identify the regions of stable motion. We also investigate situations when the particle dynamics exhibits the onset of chaos. In order to characterize the measure of chaoticness we employ techniques of Poincar\\'e surfaces of section and of recurrence plots.

Kopá?ek, Ond?ej; Karas, Vladimír; Kojima, Yasufumi

2014-01-01

205

Magnetic Dipole Moment of SGRs and AXPs Described as Massive and Magnetic White Dwarfs  

E-print Network

The Anomalous X-ray Pulsars (AXPs) and Soft Gamma-ray Repeaters (SGRs) are some of the most interesting groups of pulsars that have been intensively studied in the recent years. They are understood as neutron stars (NSs) with super strong magnetic fields, namely $B\\gtrsim10^{14}$ G. However, in the last two years two SGRs with low magnetic fields $B\\sim(10^{12}-10^{13})$ G have been detected. Moreover, three fast and very {\\it magnetic} white dwarfs (WDs) have also been observed in the last years. Based on these new pulsar discoveries, we compare and contrast the magnetic fields, magnetic dipole moment, characteristic ages, and X-ray steady luminosities of these two SGRs (in the WD model) with three fast white dwarfs, to conclude that they show strong similarities corroborating an alternative description of several SGRs/AXPs as very massive and magnetic white dwarfs. The pulsar magnetic dipole moment $m$ depending only on the momentum of inertia $I$, and observational properties, such as the period $P$ and its first time derivative $\\dot{P}$, can help to identify the scale of $I$ for SGRs/AXPs. We analyze the pulsar magnetic dipole moment $m$ of SGRs and AXPs when a model based on a massive fast rotating highly magnetized white dwarf is considered. We show that the values for $m$ obtained for several SGRs and AXPs are in agreement with the observed range $10^{34}{\\rm emu}\\leq m \\leq10^{36}{\\rm emu}$ of isolated and polar magnetic white dwarfs. This result together with the fact that for {\\it magnetic} white dwarfs $B\\sim(10^6-10^8)$ G their magnetic dipole moments are almost independent of the star rotation period ($10^{4}\\lesssim P \\lesssim10^{6} {\\rm s}$) - a phenomenology not shared by neutron stars pulsars - suggests a possible {\\it magnetic} white dwarf nature for some of SGRs/AXPs that have much smaller periods ($P\\sim 10$ s).

J. G. Coelho; M. Malheiro

2012-11-26

206

Theoretical Prediction and Impact of Fundamental Electric Dipole Moments  

E-print Network

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

Sebastian A. R. Ellis; Gordon L. Kane

2014-05-29

207

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

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

208

Progress Towards a New Measurement of the Electric Dipole Moment of ^199Hg.  

NASA Astrophysics Data System (ADS)

We are currently undertaking a four vapor cell search for the permanent electric dipole moment (EDM) of ^199Hg. The existence of a nonzero EDM would imply a source of CP violation beyond the standard model. The present limit on the EDM of ^199 Hg is |dHg| < 2.1 x10-28 ,,, which was established several years ago by our group at the University of Washington. In that experiment, two quartz vapor cells containing polarized Hg vapor were placed in parallel magnetic and anti-parallel electric fields (the use of two cells permitted the removal of common-mode effects), and the spin precession frequency was measured using an optical technique. In our current experiment, two additional cells at zero electric field serve to cancel magnetic gradient noise and to improve limits on systematic effects due to charging and leakage currents. We have recently overcome several systematic issues and begun acquiring data with our upgraded apparatus. To prevent experimenter bias from influencing the data, we have also instituted a blind analysis protocol. The statistical error of the data at the time of this writing was ±0.15x10-28 e cm, and we hope to improve the sensitivity by a further factor of two. We will discuss recent progress and our plans to place improved limits on systematic effects.

Swallows, M. D.; Griffith, W. C.; Heckel, B. R.; Fortson, E. N.; Romalis, M. V.

2007-06-01

209

Self-consistent calculations of the electric giant dipole resonances in light and heavy nuclei.  

PubMed

While bulk properties of stable nuclei are successfully reproduced by mean-field theories employing effective interactions, the dependence of the centroid energy of the electric giant dipole resonance on the nucleon number A is not. This problem is cured by considering many-particle correlations beyond mean-field theory, which we do within the quasiparticle time blocking approximation. The electric giant dipole resonances in 16O, 40Ca, and 208Pb are calculated using two new Skyrme interactions. PMID:23002827

Lyutorovich, N; Tselyaev, V I; Speth, J; Krewald, S; Grümmer, F; Reinhard, P-G

2012-08-31

210

Magnetic Measurement of the 10 kW, IR FEL Dipole Magnets  

SciTech Connect

Magnetic measurements have been performed on several families of dipoles for the 10 kW IR-FEL presently under construction at the Thomas Jefferson National Accelerator Facility. The requirements for these magnets include varying field strengths, large horizontal apertures and parts in 10,000 field homogeneity as well as setability of core and integrated field. Measurements were made to quantify the magnets according to these requirements and to determine the hysteresis protocol, ramp rate dependence, and field clamp settings that are used. This paper will describe the results of these measurements and the procedures used to accomplish them.

Tommy Hiatt; Kenneth Baggett; J. Beck; George Biallas; David Douglas; Kevin Sullivan; C. Tennant

2003-05-01

211

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

NASA Technical Reports Server (NTRS)

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

Antonucci, E.

1974-01-01

212

Calculations of magnetic field for the end design of the RHIC arc dipole  

SciTech Connect

This paper describes the results of a 3D calculation of the magnetic field in the end region of the RHIC arc dipole magnet. Multipole harmonics are obtained in the end regions of the magnet. Comparisons of these harmonics are made to the measurements of harmonics on the actual magnets.

Kahn, S.A.; Gupta, R.C.; Jain, A.K.; Morgan, G.H.; Thompson, P.A.

1993-09-01

213

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

SciTech Connect

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

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

2007-06-01

214

A six-tesla superconducting dipole magnet design and development program for POPAE  

Microsoft Academic Search

POPAE, the proposed Proton-Proton Intersecting Storage Ring Facility at Fermi National Accelerator Laboratory, will require some 1400 superconducting 6.0 T DC dipole and quadrupole magnets. The dipoles are 6. 17 m long and consist of coils of rectangular cross section clamped directly onto the 6 cm inner diameter bore tube. Aluminum is used to support the coils, and they are

J. Bywater; M. H. Foss; L. E. Genens; L. G. Hyman; R. P. Smith; L. R. Turner; S. T. Wang; S. C. Snowdon; J. R. Purcell

1977-01-01

215

Direct detection of light anapole and magnetic dipole DM  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

216

Discrepancy in the near-solute electric dipole moment calculated from the electric field.  

PubMed

The electric dipole moment p(r) was computed as the integral of the permanent dipole moment of the solvent molecule ?(r) weighted by the orientational probability distribution ?(r;O) over all orientations, where O is the orientation of the solvent molecule at r. The relationship between ?(r;O) and the potential of the mean torque was derived; p(r) is proportional to the electric field E(r) under the following assumptions: (1) the van der Waals (vdW) interaction is independent of the orientation of the solvent molecule at r; (2) the solvent molecule and its electrical effect are modeled as a point dipole moment; (3) the solvent molecule at r is in a region far from the solute; and (4) ?E(r) ? k(B) T, where k(B) is Boltzmann's constant and T is absolute temperature. The errors caused by calculating near-solute ?(r) and p(r) from E(r) are unclear. The results show that ?(r) is inconsistent with the value calculated from E(r) for water molecules in the first and second shells of solute with charge state Q = ±1 e, and a large variation in solvent molecular polarizability ?(mol) (r), which appeared in the first valley of 4?r(2) E(r) for |Q| < 1 e. Nonetheless, p(r) is consistent with the values calculated from E(r) for |Q| ? 1 e. The implication is that the assumptions for calculating p(r) can be ignored in the calculation of the solvation free energy of biomolecules, as they pertain to protein folding and protein-protein/ligand interactions. PMID:21717477

Yang, Pei-Kun

2011-10-01

217

Search For The Electric Dipole Moment Of The Neutron  

NASA Astrophysics Data System (ADS)

We report on the nEDM experiment at the Institut Laue Langevin (ILL), based on a precision measurement of the Larmor precession frequency of polarised ultra-cold neutrons stored in a cell in a magnetic field. An EDM would reveal itself by a response of the Larmor precession frequency of the neutron to an electric field applied over the storage volume. The experiment has been taking data over a period of six years and has subsequently been running for one year devoted to systematic studies related to the experiment. These systematic studies have now been completed. This experiment will result in an EDM measurement with a sensitivity of the order of 10-26 e cm. The experimental techniques used in the experiment are presented as well as the systematic studies and results of the data analysis of the experiment.

van der Grinten, Maurits

2006-07-01

218

Lossless propagation of magnetic dipole excitations on chains of dielectric particles with high refractive index  

NASA Astrophysics Data System (ADS)

Lossless propagation of longitudinal magnetic dipole waves along chains of high-index subwavelength particles is predicted for a narrow frequency range around the magnetic Mie resonance of the individual particles. Mathematical analogies between dipole and magnetoinductive waves are used to reduce back-reflections thus improving the power transfer efficiency of respective particle waveguides. The proposed technique can be used to optimize the propagation of even more complex particle-based configurations.

Zhuromskyy, O.; Peschel, U.

2014-09-01

219

Regular and chaotic dynamics of a chain of magnetic dipoles with moments of inertia  

SciTech Connect

The nonlinear dynamic modes of a chain of coupled spherical bodies having dipole magnetic moments that are excited by a homogeneous ac magnetic field are studied using numerical analysis. Bifurcation diagrams are constructed and used to find conditions for the presence of several types of regular, chaotic, and quasi-periodic oscillations. The effect of the coupling of dipoles on the excited dynamics of the system is revealed. The specific features of the Poincare time sections are considered for the cases of synchronous chaos with antiphase synchronization and asynchronous chaos. The spectrum of Lyapunov exponents is calculated for the dynamic modes of an individual dipole.

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

2009-05-15

220

Prospects for using Gd3Fe5O12 ferrite ceramics in searches for the electron permanent electric dipole moment and violation of local Lorentz invariance  

NASA Astrophysics Data System (ADS)

Gadolinium iron garnet (Gd3Fe5O12) ferrite ceramic maintains its high magnetic susceptibility down to cryogenic temperatures: our measurements at 4 K give ?=75. This gives rise to an enhancement of material magnetization that would be induced by effects such as violation of local Lorentz invariance, or orientation of permanent electric dipole moments caused by an applied electric field. Such magnetization can be detected with DC SQUID magnetometers. Magnetic noise measurements with SQUIDs at 4 K indicate that the EDM sensitivity on the level of 10-28e.cm is achievable after ten days of averaging.

Sushkov, Alexander; Eckel, Stephen; Lamoreaux, Steve

2008-05-01

221

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

NASA Astrophysics Data System (ADS)

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.

Yan, H.; Plaster, B.

2011-06-01

222

Search for electric dipole moments of light ions in storage rings  

NASA Astrophysics Data System (ADS)

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

Rathmann, F.; Saleev, A.; Nikolaev, N. N.

2014-01-01

223

Electrically active magnetic excitations in antiferromagnets (Review Article)  

NASA Astrophysics Data System (ADS)

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

Krivoruchko, V. N.

2012-09-01

224

Measurements of passive correction of magnetization higher multipoles in one meter long dipoles  

SciTech Connect

The use of passive superconductor to correct the magnetization sextupole and decapole in SSC dipoles appears to be promising. This paper presents the results of a series of experiments of passive superconductor correctors in one meter long dipole magnets. Reduction of the magnetization sextupole by a factor of five to ten has been achieved using the passive superconductor correctors. The magnetization decapole was also reduced. The passive superconductor correctors reduced the sextupole temperature sensitivity by an order of magnitude. Flux creep decay was partially compensated for by the correctors. 13 refs., 7 figs.

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

1990-09-01

225

Magnetohydrodynamic simulations of hypersonic flow over a cylinder using axial- and transverse-oriented magnetic dipoles.  

PubMed

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

226

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

NASA Astrophysics Data System (ADS)

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

Weidelt, Peter

2000-06-01

227

Electric dipole moments of charged leptons in the split fermion scenario in the two Higgs doublet model  

E-print Network

We predict the charged lepton electric dipole moments in the split fermion scenario in the framework of the two Higgs doublet model. We observe that the numerical value of the muon (tau) electric dipole moment is at the order of the magnitude of $10^{-22} (e-cm)$ ($10^{-20} (e-cm)$) and there is an enhancement in the case of two extra dimensions, especially for the tau lepton electric dipole moment.

E. O. Iltan

2005-02-28

228

The Secret Life of the Dipole  

E-print Network

A new force on the magnetic dipole, which exists in the presence of both electric and magnetic fields, is described. Its origin due to the `hidden momentum', implications and possible experimental tests are discussed.

Jeeva S. Anandan

1998-12-14

229

Production of trilobite Rydberg molecule dimers with thousand-Debye permanent electric dipole moments  

E-print Network

We observe that when an ultracold ground state cesium (Cs) atom becomes bound within the electronic cloud of an extended Cs electronic orbit, ultralong-range molecules with giant (kilo-Debye) permanent electric dipole moments form. Large molecular permanent electric dipole moments are challenging to experimentally realize. Meeting this challenge has garnered significant interest because 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. These new hybrid class of `trilobite' molecules are predominated with degenerate Rydberg manifolds, making them difficult to produce with conventional optical association. Their behavior is quantitatively reproduced with detailed coupled-channel calculations.

Booth, Donald; Yang, Jin; Sadeghpour, Hossein; Shaffer, James

2014-01-01

230

^3He comagnetometer readout for the neutron electric dipole moment (nEDM) experiment at SNS  

NASA Astrophysics Data System (ADS)

The nEDM collaboration is developing a new experiment to measure the neutron's electric dipole moment to ˜10-28 e--cm. A non-zero neutron EDM would be the first observation of CP violation in a baryon containing only light quarks, while a null result would be inconsistent with predictions from most variants of supersymmetry. The experiment will measure the difference in spin precession, of polarized ultracold neutrons (UCN) produced and stored in a superfluid-helium-filled cell, when the magnetic and electric fields are parallel and antiparallel. A key feature of the experimental method is the use of polarized ^3He atoms within the cell acting as both spin analyzer and comagnetometer to the UCN. In one mode of running, the ^3He precession signal is detected by SQUID gradiometers adjacent to the cell. This talk will cover the efforts of the nEDM collaboration towards practical implementation of SQUIDs for the ^3He comagnetometer readout, with a goal of <=1 fT/?Hz noise level (referred to one gradiometer loop), low enough to be a small contribution to the overall uncertainty of the final nEDM result. )

Clayton, Steven

2010-02-01

231

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

E-print Network

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

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

2014-01-01

232

On the Electric Dipole Polarizability of the Three-Hadron Bound System  

E-print Network

A simple analytical expression for the electric dipole polarizability of the three-hadron bound system having only one stable bound state has been derived neglecting by the higher orbital components of the off-shell three-body transition matrix at the energy of the bound state. As a case in point, we have estimated the electric dipole polarizability of the triton, using a cluster triton wave function and the Hulthen potential to describe the related p-n and n-d bound states.

V. F. Kharchenko; A. V. Kharchenko

2010-03-30

233

A Ten-Fold Improvement to the Limit of the Electron Electric Dipole Moment  

NASA Astrophysics Data System (ADS)

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.

Spaun, Benjamin Norman

234

What Are Electric and Magnetic Fields? (EMF)  

MedlinePLUS

What are Electric and Magnetic Fields? (EMF) Electric and Magnetic Fields Electricity is an essential part of our lives. Electricity powers all sorts of things around us, from computers to refrigerators ...

235

Molecular Expressions: Electricity and Magnetism  

NSDL National Science Digital Library

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

Davidson, Michael

2010-03-16

236

Negative refraction of dipole-exchange spin waves through a magnetic twin interface in restricted geometry  

Microsoft Academic Search

A phenomenon of negative refraction of dipole-exchange spin waves (DESWs) was demonstrated by micromagnetic modeling, based on the fact that the DESWs' dispersion is anisotropic according to the relative orientation of the DESW propagation direction with respect to the orientation of local static magnetizations. Using this anisotropic dispersion behavior, the negative refraction of the DESWs was reproduced through a magnetic

Sang-Koog Kim; Sangkook Choi; Ki-Suk Lee; Dong-Soo Han; Dae-Eun Jung; Youn-Seok Choi

2008-01-01

237

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

SciTech Connect

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

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

2007-06-01

238

2D Magnetic Design and Optimization of a 88-mm Aperture 15 T Dipole for NED  

Microsoft Academic Search

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

Nikolai Schwerg; Christine Vollinger; Arnaud Devred; Daniel Leroy

2007-01-01

239

Generation of a quasi-stationary electromagnetic field by a distributed magnetic dipole moving in a collisionless plasma  

Microsoft Academic Search

The problem of the excitation of quasi-stationary electromagnetic fields by a moving magnetic dipole is solved within the framework of the kinetic equation for collisionless plasma using methods of the linear theory of particle emission. A multipole representation is obtained for fields at small and large distances from the dipole. The quasi-stationary electromagnetic fields excited by a dipole are pressed

V. M. Gubchenko

1988-01-01

240

Determination of Nanocrystal Size Distribution in Magnetic Multicore Particles Including Dipole-Dipole Interactions and Magnetic Anisotropy: a Monte Carlo Study  

NASA Astrophysics Data System (ADS)

A correct estimate of the size distribution (i.e., median diameter D and geometric standard deviation ?) of the magnetic nanocrystals (MNCs) embedded in magnetic multicore particles is a necessity in most applications relying on the magnetic response of these particles. In this paper we use a Monte Carlo method to simulate the equilibrium magnetization of two types of multicore particles: (I) MNCs fused in a random compact cluster, and (II) MNCs distributed on the surface of a large carrier sphere. The simulated magnetization data are then fitted using a common method based on a Langevin equation weighted with a size distribution function. Finally, the fitting parameters Dm and ?m are compared to the real parameters Dp and ?p used to generate the MNCs. Our results show that fitting magnetization data with a Langevin model that neglects magnetic anisotropy and dipole-dipole interactions leads to an erroneous estimate of the size distribution of the MNCs in multicore particles. The magnitude of the error depends on the particle morphology, number of MNCs contained in the particle and magnetic properties of the MNCs.

Schaller, Vincent; Wahnström, Göran; Sanz-Velasco, Anke; Enoksson, Peter; Johansson, Christer

2010-12-01

241

Electric and Magnetic Forces: Electric Charges  

NSDL National Science Digital Library

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

National Science Teachers Association (NSTA)

2008-10-30

242

Atomic-scale study of electric dipoles near charged and uncharged domain walls in ferroelectric films.  

PubMed

Ferroelectrics are materials exhibiting spontaneous electric polarization due to dipoles formed by displacements of charged ions inside the crystal unit cell. Their exceptional properties are exploited in a variety of microelectronic applications. As ferroelectricity is strongly influenced by surfaces, interfaces and domain boundaries, there is great interest in exploring how the local atomic structure affects the electric properties. Here, using the negative spherical-aberration imaging technique in an aberration-corrected transmission electron microscope, we investigate the cation-oxygen dipoles near 180 degrees domain walls in epitaxial PbZr(0.2)Ti(0.8)O(3) thin films on the atomic scale. The width and dipole distortion across a transversal wall and a longitudinal wall are measured, and on this basis the local polarization is calculated. For the first time, a large difference in atomic details between charged and uncharged domain walls is reported. PMID:18066068

Jia, Chun-Lin; Mi, Shao-Bo; Urban, Knut; Vrejoiu, Ionela; Alexe, Marin; Hesse, Dietrich

2008-01-01

243

Dipole orientation and surface cluster size effects on chemisorption-induced magnetism: a DFT study of the interaction of gold-thiopolypeptide.  

PubMed

A nanosystem formed by a high electric dipole moment thiopolypeptide alpha-helix, consisting of eight l-glycine units, chemisorbed on the (111) surface of Au23 and Au55 clusters, with the S as the linking atom, was studied using the wave function broken symmetry UDFT method. We have found a strong correlation between the orientation of the electric dipole of the alpha-helix and charge transfer and the magnetic behavior of the adsorbate-cluster system. Upon chemisorption, dipole moments may be quenched or enhanced, with respect to the gas phase value, with the strongest reduction corresponding to the magnetic state. A reduction of the alpha-helix's electric dipole with the net charge transfer from the Au surface was obtained for the more stable state. In this state description, it may happen that the calculated spin densities of the chemisorbed alpha-helix and its free radical form are similar. The magnetic properties are strongly dependent on the size of the Au cluster and on its electronic structure with respect to nuclei positions. In general, the localized spin density per atom increases and the magnetization of the extended system decreases with cluster size, a trend found experimentally for organic monolayers with a similar type of adsorbate we consider here. PMID:18788718

Puerta, Luis; Franco, Héctor J; Murgich, Juan; Gonzalez, Carlos; Simón-Manso, Yamil; Mujica, Vladimiro

2008-10-01

244

Magnetic dipole moment of a spherical shell with TRM acquired in a field of internal origin. [Thermoremanent Magnetization implications for lunar magnetic field  

NASA Technical Reports Server (NTRS)

The acquisition of thermoremanent magnetization (TRM) by a cooling spherical shell is studied for internal magnetizing dipole fields, using Runcorn's (1975) theorems on magnetostatics. If the shell cools progressively inward, inner regions acquire TRM in a net field composed of the dipole source term plus a uniform field due to the outer magnetized layers. In this case, the global dipole moment and external remanent field are nonzero when the whole shell has cooled below the Curie point and the source dipole has disappeared. The remanent field outside the shell is found to depend on the thickness, radii, and cooling rate of the shell, as well as the coefficient of TRM and the intensity of the magnetizing field. Some implications for the moon's remanent dipole moment are discussed.

Srnka, L. J.

1976-01-01

245

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

246

A proposal for continuous loading of an optical dipole trap with magnetically guided ultra cold atoms  

E-print Network

The capture of a moving atom by a non-dissipative trap, such as an optical dipole trap, requires the removal of the excessive kinetic energy of the atom. In this article we develop a mechanism to harvest ultra cold atoms from a guided atom beam into an optical dipole trap by removing their directed kinetic energy. We propose a continuous loading scheme where this is accomplished via deceleration by a magnetic potential barrier followed by optical pumping to the energetically lowest Zeeman sublevel. We theoretically investigate the application of this scheme to the transfer of ultra cold chromium atoms from a magnetically guided atom beam into a deep optical dipole trap. We discuss the realization of a suitable magnetic field configuration. Based on numerical simulations of the loading process we analyze the feasibility and efficiency of our loading scheme.

Anoush Aghajani-Talesh; Markus Falkenau; Axel Griesmaier; Tilman Pfau

2009-12-11

247

Microstructure and magnetic properties of magnetic fluids consisting of shifted dipole particles under the influence of an external magnetic field  

NASA Astrophysics Data System (ADS)

We investigate the structure of a recently proposed magnetic fluid consisting of shifted dipolar (SD) particles in an externally applied magnetic field via computer simulations. For standard dipolar fluids the applied magnetic field usually enhances the dipole-dipole correlations and facilitates chain formation whereas in the present system the effect of an external field can result in a break-up of clusters. We thoroughly investigate the origin of this phenomenon through analyzing first the ground states of the SD-particle systems as a function of an applied field. In a second step we quantify the microstructure of these systems as functions of the shift parameter, the effective interaction parameter, and the applied magnetic field strength. We conclude the paper by showing that with the proper choice of parameters, it is possible to create a system of SD-particles with highly interacting magnetic particles, whose initial susceptibility is below the Langevin susceptibility, and which remains spatially isotropic even in a very strong external magnetic field.

Weeber, Rudolf; Klinkigt, Marco; Kantorovich, Sofia; Holm, Christian

2013-12-01

248

Microstructure and magnetic properties of magnetic fluids consisting of shifted dipole particles under the influence of an external magnetic field.  

PubMed

We investigate the structure of a recently proposed magnetic fluid consisting of shifted dipolar (SD) particles in an externally applied magnetic field via computer simulations. For standard dipolar fluids the applied magnetic field usually enhances the dipole-dipole correlations and facilitates chain formation whereas in the present system the effect of an external field can result in a break-up of clusters. We thoroughly investigate the origin of this phenomenon through analyzing first the ground states of the SD-particle systems as a function of an applied field. In a second step we quantify the microstructure of these systems as functions of the shift parameter, the effective interaction parameter, and the applied magnetic field strength. We conclude the paper by showing that with the proper choice of parameters, it is possible to create a system of SD-particles with highly interacting magnetic particles, whose initial susceptibility is below the Langevin susceptibility, and which remains spatially isotropic even in a very strong external magnetic field. PMID:24320398

Weeber, Rudolf; Klinkigt, Marco; Kantorovich, Sofia; Holm, Christian

2013-12-01

249

Search for electric dipole moment in 129Xe atom using a nuclear spin oscillator  

NASA Astrophysics Data System (ADS)

We aim to measure the electric dipole moment (EDM) of a diamagnetic atom 129Xe using an optical-detection nuclear spin maser technique. The relation of EDM in a diamagnetic atom to nuclear Schiff moment and fundamental sources generating it is discussed, and the present status for the development of our experimental setup is presented.

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

2014-01-01

250

Theory of Electric Dipole Moment of Atomic Rubidium due to Parity and Time Reversal Violation  

Microsoft Academic Search

A nonzero electric dipole moment (EDM) of a nondegenerate quantum mechanical system, in general, and an atom, in particular, will be a signature of the violation of both the parity (P) and the time reversal (T) symmetries. There are several possible mechanisms which can lead to P and T violation in atomic systems, and hence a permanent atomic EDM. In

Alok Shukla

1991-01-01

251

Power loss of an oscillating electric dipole in a quantum plasma  

SciTech Connect

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

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

2012-12-15

252

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

E-print Network

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

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

2006-01-09

253

Mechanical analysis of the Nb3Sn dipole magnet HD1  

Microsoft Academic Search

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

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

254

Generation of a quasisteady electromagnetic field by a distributed magnetic dipole moving in a collisionless plasma  

SciTech Connect

The problem of the excitation of quasisteady electromagnetic fields by a moving dipole with a moment directed perpendicularly to its velocity is solved using the linear theory of particle emission based on the kinetic equation for a collisionless plasma. A multipole representation is derived for the fields at large and small distances from the dipole. The quasisteady electromagnetic fields excited by the dipole are squeezed against it. The currents in the plasma screen the field of the dipole, and an anomalous skin region with a typical size r/sub G/ = (..sigma../sub ..cap alpha../ ..sqrt pi../2 ..omega../sub p//sub ..cap alpha../ /sup 2/v'/c/sup 2/v/sub ..cap alpha../)/sup -1/2/ forms (..omega../sub p//sub ..cap alpha../ is the plasma frequency, v' is the velocity of the dipole, v/sub ..cap alpha../ is the thermal velocity, and c is the velocity of light). In this anomalous skin region, the energy of the dipole is dissipated resonantly and converted into plasma particle energy through the excited quasisteady electromagnetic field. The rate of this process, the radiation resistance, and the stopping force exerted on the dipole are all calculated. An anomalous collisionless magnetic Reynolds number is defined. This Reynolds number characterizes the role played by conductivity effects in a collisionless plasma.

Gubchenko, V.M.

1988-03-01

255

An improved limit on the electric dipole moment of the muon  

NASA Astrophysics Data System (ADS)

A search for a muon electric dipole moment (EDM) has been performed at the Brookhaven National Laboratory muon storage ring using data from the 2000 run of the muon g - 2 experiment. An EDM in an elementary particle would violate parity and time reversal symmetry. Polarized muons were injected into the 7m radius storage ring at 3.1GeV. The difference between their precession and cyclotron frequencies (o a = op - o c) was measured to determine their anomalous magnetic moment. A muon EDM would cause a tilt in the precession plane, resulting in an oscillation in the vertical position of positron hits on the detectors at o a. An oscillation amplitude of -1.3+/-5.9stat+/-10.4sys mm was measured, giving an EDM measurement of -0.1+/-1.4x 10-19e-cm Given that this is consistent with zero, a new muon EDM limit of 2.8x10-19e-cm 95%CL has been set. Combining this with the previous measurement of the muon EDM from the CERN g - 2 experiment [1] produces a limit of 2.7x10-19e-cm 95%CL.

McNabb, Ronald Steven, Jr.

256

Searching for the electron electric dipole moment in an electrostatic storage ring  

NASA Astrophysics Data System (ADS)

A non-zero permanent electric dipole moment (EDM) of an electron would violate parity and time-reversal symmetries. Non-zero EDMs are predicted in the standard model, but are unobservably small. New physics incorporating new particles and new CP-violating phases can lead, through radiative corrections, to dramatic enhancements of the electron EDM, to within a few orders of magnitude of the current experimental limit. A new approach to electron EDM searches using molecular ions stored in a table-top electrostatic storage ring is described. Molecular ions with long-lived paramagnetic states such as WN^+ can be injected and stored in larger numbers and with longer coherence times than competing experiments, leading to high sensitivity to an electron EDM. Systematic effects mimicking an EDM such as those due to motional magnetic fields and geometric phases are found not to limit the approach in the short term. Sensitivities of ?|de| 10-30 e.cm/day, an improvement by three orders of magnitude, appear possible under conservative conditions.

Kawall, David

2011-04-01

257

Search for a permanent electric dipole moment using liquid 129Xe  

SciTech Connect

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

PROFESSOR MICHAEL ROMALIS

2008-11-24

258

Dipole moment of a small water cluster. The effect of size, temperature, and electric field  

Microsoft Academic Search

A molecular dynamics simulation of neutral clusters (H2O)\\u000a n ? 21 has been performed in the framework of the flexible polarized model. The formation and evolution of the dipole moment of\\u000a the cluster have been investigated with a change in the size and temperature of the cluster and an external electric field.\\u000a It has been shown that at low electric

D. Yu. Dubov; A. A. Vostrikov

2010-01-01

259

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

Microsoft Academic Search

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

Ronald W. P. King; Sheldon S. Sandler

1994-01-01

260

Paddlefish strike at artificial dipoles simulating the weak electric fields of planktonic prey.  

PubMed

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

Wojtenek, W; Pei, X; Wilkens, L A

2001-04-01

261

Magnetic field distribution of injection chicane dipoles in Spallation Neutron Source accumulator ring  

NASA Astrophysics Data System (ADS)

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.

Wang, J. G.

2006-01-01

262

Electric and Magnetic Forces  

NSDL National Science Digital Library

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

2010-02-10

263

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

SciTech Connect

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

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

1992-09-01

264

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

NASA Astrophysics Data System (ADS)

We address a number of issues regarding solid-state electron electric-dipole moment (EDM) experiments, focusing on gadolinium-iron garnet [(GdIG) chemical formula Gd3Fe5O12 ] as a possible sample material. GdIG maintains its high magnetic susceptibility down to 4.2 K, which enhances the EDM-induced magnetization of a sample placed in an electric field. We estimate that lattice polarizability gives rise to an EDM enhancement factor of approximately 20. We also calculate the effect of the demagnetizing field for various sample geometries and permeabilities. Measurements of intrinsic GdIG magnetization noise are presented, and the fluctuation-dissipation theorem is used to compare our data with the measurements of the imaginary part of GdIG permeability at 4.2 K, showing good agreement above frequencies of a few hertz. We also observe how the demagnetizing field suppresses the noise-induced magnetic flux, confirming our calculations. The statistical sensitivity of an EDM search based on a solid GdIG sample is estimated to be on the same level as the present experimental limit. Such a measurement would be valuable given the completely different methods and systematics involved. The most significant systematics in such an experiment are the magnetic hysteresis and the magnetoelectric effect. Our analysis shows that it should be possible to control these at the level of statistical sensitivity.

Sushkov, A. O.; Eckel, S.; Lamoreaux, S. K.

2009-02-01

265

Fabrication and Test Results of a Nb3Sn Superconducting Racetrack Dipole Magnet  

SciTech Connect

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.

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

266

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

NASA Astrophysics Data System (ADS)

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

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

2010-06-01

267

Measurement of net electric charge and dipole moment of dust aggregates in a complex plasma  

NASA Astrophysics Data System (ADS)

Understanding the agglomeration of dust particles in complex plasmas requires knowledge of basic properties such as the net electrostatic charge and dipole moment of the dust. In this study, dust aggregates are formed from gold-coated mono-disperse spherical melamine-formaldehyde monomers in a radiofrequency (rf) argon discharge plasma. The behavior of observed dust aggregates is analyzed both by studying the particle trajectories and by employing computer models examining three-dimensional structures of aggregates and their interactions and rotations as induced by torques arising from their dipole moments. These allow the basic characteristics of the dust aggregates, such as the electrostatic charge and dipole moment, as well as the external electric field, to be determined. It is shown that the experimental results support the predicted values from computer models for aggregates in these environments.

Yousefi, Razieh; Davis, Allen B.; Carmona-Reyes, Jorge; Matthews, Lorin S.; Hyde, Truell W.

2014-09-01

268

Electric dipole response of $^6$He: Halo-neutron and core excitations  

E-print Network

Electric dipole ($E1$) response of $^{6}$He is studied with a fully microscopic six-body calculation. The wave functions for the ground and excited states are expressed as a superposition of explicitly correlated Gaussians (CG). Final state interactions of three-body decay channels are explicitly taken into account. The ground state properties and the low-energy $E1$ strength are obtained consistently with observations. Two main peaks as well as several small peaks are found in the $E1$ strength function. The peak at the high-energy region indicates a typical macroscopic picture of the giant dipole resonance, the out-of-phase proton-neutron motion. The transition densities of the lower-lying peaks exhibit in-phase proton-neutron motion in the internal region, out-of-phase motion near the surface region, and spatially extended neutron oscillation, indicating a soft-dipole mode (SDM) and its vibrationally excited mode.

D. Mikami; W. Horiuchi; Y. Suzuki

2014-05-24

269

Magnetic Fields Analogous to electric field, a magnet  

E-print Network

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

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

270

Measurements of vacuum magnetic birefringence using permanent dipole magnets: the PVLAS experiment  

NASA Astrophysics Data System (ADS)

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 quantum electrodynamics (QED) vacuum and is predicted by the Euler-Heisenberg-Weisskopf effective Lagrangian. It can be detected by measuring the ellipticity acquired by a linearly polarized 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. Here we report the results of a scaled-down test setup and describe the new PVLAS apparatus. This latter is in construction and is based on a high-sensitivity ellipsometer with a high-finesse Fabry-Perot cavity (>4 × 105) 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 Ae, which determines the strength of the nonlinear terms in the QED Lagrangian: A(PVLAS)e < 3.3 × 10-21 T-2 at 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.

Della Valle, F.; Gastaldi, U.; Messineo, G.; Milotti, E.; Pengo, R.; Piemontese, L.; Ruoso, G.; Zavattini, G.

2013-05-01

271

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

SciTech Connect

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

Taras, P.; /Quebec U., Montreal

2007-07-09

272

Lymphocyte fractionation using immunomagnetic colloid and a dipole magnet flow cell sorter  

Microsoft Academic Search

The relationship between cell function and surface marker expression is a subject of active investigation in biology and medicine. These investigations require separating cells of a homogeneous subset into multiple fractions of varying marker expression. We have developed a novel cell sorter, the dipole magnet flow sorter (DMFS), which separates selected T lymphocyte subpopulations, targeted by immunomagnetic colloid, into multiple

Lee R. Moore; Maciej Zborowski; Liping Sun; Jeffrey J. Chalmers

1998-01-01

273

Chapter 5. An example from statistical mechanics 5.1 Magnetic dipole systems  

E-print Network

Chapter 5. An example from statistical mechanics 5.1 Magnetic dipole systems Consider a two-Boltzmann distribution is one of the foundations of Statistical Mechanics, and can be derived by considering to the reservoir. #12;44 An example from statistical mechanics The entropy of such a system is defined to be S D k

274

The Dipole and Cuadrupole Aproximation of the Earth Magnetic Field for Monitoring the Temporal Evolution  

Microsoft Academic Search

In the present work are compiled the coefficients of spherical harmonics analysis representing the dipole and cuadrupole aproximation of the Earth Magnetic Field, from 1550 to 2005 years. The temporal variation of each coefficient are approximately by a non linear function in the interval of study and then forecasting the values up to year 2100. The position of the excentric

J. C. Gianibelli

2007-01-01

275

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

Microsoft Academic Search

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

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

1989-01-01

276

Is the adiabatic approximation sufficient to account for the post-Born-Oppenheimer effects on molecular electric dipole moments?  

Microsoft Academic Search

We estimated the post-Born–Oppenheimer (post-BO) contribution to electric dipole moments by finite-field derivatives of the diagonal Born–Oppenheimer correction computed with correlated electronic wave functions. The new method is used to examine the effect of isotopic substitution on the dipole moments of the HD, LiH, LiD, and H2 O molecules. The non-zero dipole moment of HD is solely due to the

Sandra L. Hobson; Edward F. Valeev; Attila G. Császár; John F. Stanton

2009-01-01

277

Disk Formation by Asymptotic Giant Branch Winds in Dipole Magnetic Fields  

NASA Astrophysics Data System (ADS)

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-1) outflow (10-5 Msolar yr-1) from an asymptotic giant branch 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.

Matt, Sean; Balick, Bruce; Winglee, Robert; Goodson, Anthony

2000-12-01

278

Observation of electric-dipole-forbidden infrared transitions in cold molecular ions  

NASA Astrophysics Data System (ADS)

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.

Germann, Matthias; Tong, Xin; Willitsch, Stefan

2014-11-01

279

Microscopic probe for vector measurement of both the electric and the magnetic field of light  

E-print Network

Microscopic probe for vector measurement of both the electric and the magnetic field of light microscopic imaging of light", Nature Photonics, 1, 53-56, 2007. 2. H. W. Kihm et al., "Bethe(Near-field Scanning Optical Microscope) tip (electric dipole) (1) hole tip (2

Park, Namkyoo

280

Orbital and spin motion in a storage ring with static electric and magnetic fields  

NASA Astrophysics Data System (ADS)

I present the fundamental electrodynamic equations of motion for the orbital and spin motion in a storage ring with static electric and magnetic fields, including motion in pure electrostatic fields. In particular, I treat strong focusing lattices and synchrotron oscillations. This generalizes and extends the work of previous authors. I also treat the spin motion, including a possible permanent electric dipole moment (EDM).

Mane, S. R.

2012-09-01

281

Physics Topics: Electricity and Magnetism  

NSDL National Science Digital Library

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

Tatum, J. B.

2006-11-14

282

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

E-print Network

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

Young Jin Kim; Steven M. Clayton

2012-10-17

283

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

E-print Network

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

Kim, Young Jin

2012-01-01

284

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

NASA Astrophysics Data System (ADS)

We introduce the Time Dependent Equivalent Source Dipole (TD-ESD) method developed with the purpose of modeling the Hermean magnetic field. It takes into account the partial orbital coverage provided by MErcury Surface, Space ENvironment, Geochemistry, and Ranging (MESSENGER) mission. The TD-ESD method is based on the Equivalent Source Dipole approach, which has been largely used to downward or upward continue to constant altitude measurements of magnetic fields of crustal origin, on local or global scale. In this present application to Mercury, for which an internal core field is expected, the dipoles are uniformly distributed at a spherical surface placed deep into the planet's interior. Both their magnitude and directions are not a priori imposed and are free to evolve with time. Using synthetic data generated at MESSENGER orbit positions we successfully recover the three components of the magnetic field. We also recover the temporal variation that we a priori imposed. We find that downward and upward continuation is possible over a certain limited region. The resulting field is within 6% of the initial field for altitudes ranging between -100km and 1500km. Here we present the first constant altitude magnetic field maps derived from MESSENGER measurements acquired during the first mercury's solar day. We identify a strong time dependent signature of the external magnetic field, even when only measurements over the northern hemisphere below ~1000 km altitude are used. A future improvement of the method will consist in the simultaneous analysis of the external and internal magnetic fields.

Oliveira, Joana; Langlais, Benoit; Amit, Hagay; Pais, Maria Alexandra

2014-05-01

285

Study on Ampere-Turns of superconducting dipole and quadrupole magnets based on sector coils  

NASA Astrophysics Data System (ADS)

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.

Zhu, Yingshun; Wu, Yingzhi; Kang, Wen; Yang, Mei

2014-03-01

286

Design of Racetrack Coils for High Field Dipole Magnets  

SciTech Connect

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.

Sabbi, G.; Caspi, S.; Gourlay, S.A.; Hafalia, R.; Jackson, A.; Lietzke, A.; McInturff, A.D.; Scanlan, R.M.

2000-09-08

287

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

SciTech Connect

Background: Recent experiments on the electric dipole (E1) polarizability in heavy nuclei have stimulated theoretical interest in the low-energy electric dipole strength, both isovector and isoscalar. Purpose: We study the information content carried by the electric dipole strength with respect to isovector and isoscalar indicators characterizing bulk nuclear matter and finite nuclei. To separate isoscalar and isovector modes, and low-energy strength and giant resonances, we analyze the E1 strength as a function of the excitation energy E and momentum transfer q. Methods: We use the self-consistent nuclear density functional theory with Skyrme energy density functionals, augmented by the random phase approximation, to compute the E1 strength and covariance analysis to assess correlations between observables. Calculations are performed for the spherical, doubly magic nuclei 208Pb and 132Sn. Results: We demonstrate that E1 transition densities in the low-energy region below the giant dipole resonance exhibit appreciable state dependence and multinodal structures, which are fingerprints of weak collectivity. The correlation between the accumulated low-energy strength and the symmetry energy is weak, and dramatically depends on the energy cutoff assumed. On the other hand, a strong correlation is predicted between isovector indicators and the accumulated isovector strength at E around 20 MeV and momentum transfer q 0.65 fm 1. Conclusions: Momentum- and coordinate-space patterns of the low-energy dipole modes indicate a strong fragmentation into individual particle-hole excitations. The global measure of low-energy dipole strength correlates poorly with the nuclear symmetry energy and other isovector characteristics. Consequently, our results do not support the suggestion that there exists a collective pygmy dipole resonance, which is a strong indicator of nuclear isovector properties. By considering nonzero values of momentum transfer, one can isolate individual excitations and nicely separate low-energy excitations from the T=1 and T=0 giant collective modes. That is, measurements at q>0 may serve as a tool to correlate the E1 strength with certain bulk observables, such as incompressibility and symmetry energy.

Reinhard, P.-G. [Inst. fur Theoretische Physik II, Univ. Erlangen-Numberg, Germany; Nazarewicz, Witold [UTK/ORNL/University of Warsaw

2013-01-01

288

Effect of dipole ordering on the electrical properties of the interface between two organic insulators  

NASA Astrophysics Data System (ADS)

The "polar catastrophe" hypothesis on the mechanism of the formation of a two-dimensional conducting channel at the interface between two insulators is investigated experimentally. In particular, the influence of the concentration of dipolar groups at one of the surfaces on the electrical conductivity along the interface between two organic polymer insulators is studied. Poly(diphenylene phthalide) with phthalide side groups, possessing a relatively large dipole moment, is used as the polymer. The concentration of dipoles at the surface is varied by adding a low-molecular compound to the material. It is found that the concentration of dipolar groups has a considerable effect on the electrical conductivity along the polymer/polymer interface. A decrease in the conductivity of the interface at high concentrations of the low-molecular additive is explained on the basis of atomic-force microscopy data by the features of the supramolecular structure of the composite and the increasing imperfection of the interface.

Gadiev, R. M.; Lachinov, A. N.; Galiev, A. F.; Kalimullina, L. R.; Nabiullin, I. R.

2014-10-01

289

New constraint from Electric Dipole Moments on chargino baryogenesis in MSSM  

E-print Network

A commonly accepted mechanism of generating baryon asymmetry in the minimal supersymmetric standard model (MSSM) depends on the CP violating relative phase between the gaugino mass and the Higgsino mu term. The direct constraint on this phase comes from the limit of electric dipole moments (EDM) of various light fermions. To avoid such a constraint, a scheme which assumes the first two generation sfermions are very heavy is usually evoked to suppress the one-loop EDM contributions. We point out that under such a scheme the most severe constraint may come from a new contribution to the electric dipole moments of the electron, the neutron or atoms via the chargino sector at the two-loop level. As a result, the allowed parameter space for baryogenesis in MSSM is severely constrained, independent of masses of the first two generation sfermions.

Darwin Chang; We-Fu Chang; Wai-Yee Keung

2002-05-08

290

Persistent currents for a moving neutral particle with no permanent electric dipole moment  

NASA Astrophysics Data System (ADS)

Topological effects on the confinement of a moving neutral particle with an induced electric dipole moment confined to a quantum ring and a two-dimensional quantum dot (described by a hard-wall confining potential) are investigated. It is shown in this work that the spectrum of energy depends on the geometric phase obtained by Wei et al. [H. Wei, R. Han, X. Wei, Phys. Rev. Lett. 75, 2071 (1995)] and persistent currents arise from this dependence in both the quantum ring and the quantum dot. Further, the behaviour of the analogue of the Landau system for a moving electric dipole confined to a two-dimensional quantum dot is discussed, and it is shown that persistent currents are absent in this case.

Bakke, Knut; Furtado, Claudio

2014-10-01

291

Probing CP violation with the electric dipole moment of atomic mercury  

E-print Network

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

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

2009-02-27

292

Global Electrical Conductivity Magnetic Satellite Induction Studies  

E-print Network

induction to measure Earth conductivity: · Magnetotelluric (MT) method Measure electric and magnetic fields-varying magnetic field induces electric currents in conductors. � E = - B t Secondary magnetic fields created by these currents appose the primary magnetic field. So, conductors attenuate magnetic fields. 2nd

Constable, Steve

293

Designing dielectric resonators on substrates: combining magnetic and electric resonances.  

PubMed

High-performance integrated optics, solar cells, and sensors require nanoscale optical components at the surface of the device, in order to manipulate, redirect and concentrate light. High-index dielectric resonators provide the possibility to do this efficiently with low absorption losses. The resonances supported by dielectric resonators are both magnetic and electric in nature. Combined scattering from these two can be used for directional scattering. Most applications require strong coupling between the particles and the substrate in order to enhance the absorption in the substrate. However, the coupling with the substrate strongly influences the resonant behavior of the particles. Here, we systematically study the influence of particle geometry and dielectric environment on the resonant behavior of dielectric resonators in the visible to near-IR spectral range. We show the key role of retardation in the excitation of the magnetic dipole (MD) mode, as well as the limit where no MD mode is supported. Furthermore, we study the influence of particle diameter, shape and substrate index on the spectral position, width and overlap of the electric dipole (ED) and MD modes. Also, we show that the ED and MD mode can selectively be enhanced or suppressed using multi-layer substrates. And, by comparing dipole excitation and plane wave excitation, we study the influence of driving field on the scattering properties. Finally, we show that the directional radiation profiles of the ED and MD modes in resonators on a substrate are similar to those of point-dipoles close to a substrate. Altogether, this work is a guideline how to tune magnetic and electric resonances for specific applications. PMID:24216852

van de Groep, J; Polman, A

2013-11-01

294

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

Microsoft Academic Search

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

Steven Weinberg

1989-01-01

295

Terminal Impedance and Antenna Current Distribution of a VLF Electric Dipole in the Inner Magnetosphere  

Microsoft Academic Search

The current distribution and input impedance of an electric dipole antenna operating in a cold magnetoplasma at very low frequency (VLF) is determined through numerical simulation. A full wave solution of Maxwell's equations using a finite-difference frequency-domain (FDFD) method is implemented to simulate electromagnetic wave propagation in this highly anisotropic medium. The classical perfectly matched-layer (PML) boundary condition is found

Timothy W. Chevalier; Umran S. Inan; Timothy F. Bell

2008-01-01

296

Torque for electron spin induced by electron permanent electric dipole moment  

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

297

Study on the fermion systems coupled by electric dipol interaction with the free electromagnetic field  

NASA Astrophysics Data System (ADS)

We established a master equation for a system of fermions coupled by electric dipol interaction with the free electromagnetic field. This equation has a Lindblad equation form, with a hamiltonian part corresponding to the shell model and a dissipative part with microscopic coefficients depending on physical constants, matrix elements, and temperature. The dependence on the transition energy of the dissipative coefficients satisfies asymptothycal conditions for the energy transfer in full agreement with the principle of the detailed balance.

Stefanescu, Eliade; Sterian, Andreea R.; Sterian, Paul

2005-06-01

298

rf Wien filter in an electric dipole moment storage ring: The ``partially frozen spin'' effect  

NASA Astrophysics Data System (ADS)

An rf Wien filter (WF) can be used in a storage ring to measure a particle’s electric dipole moment (EDM). If the WF frequency equals the spin precession frequency without WF, and the oscillating WF fields are chosen so that the corresponding transverse Lorentz force equals zero, then a large source of systematic errors is canceled but the EDM signal is not. This effect, discovered by simulation, can be called the “partially frozen spin” effect.

Morse, William M.; Orlov, Yuri F.; Semertzidis, Yannis K.

2013-11-01

299

The electric dipole moment of the nucleon from simulations at imaginary vacuum angle theta  

E-print Network

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.

R. Horsley; T. Izubuchi; Y. Nakamura; D. Pleiter; P. E. L. Rakow; G. Schierholz; J. Zanotti

2008-08-10

300

Preliminary analysis of coil wedge dimensional variation in SSC Prototype Dipole Magnets  

SciTech Connect

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).

Pollock, D.; Brown, G.; Dwyer, S.; Gattu, R.; Warner, D.

1993-05-01

301

Nondestructive evaluation using dipole model analysis with a scan type magnetic camera  

NASA Astrophysics Data System (ADS)

Large structures such as nuclear power, thermal power, chemical and petroleum refining plants are drawing interest with regard to the economic aspect of extending component life in respect to the poor environment created by high pressure, high temperature, and fatigue, securing safety from corrosion and exceeding their designated life span. Therefore, technology that accurately calculates and predicts degradation and defects of aging materials is extremely important. Among different methods available, nondestructive testing using magnetic methods is effective in predicting and evaluating defects on the surface of or surrounding ferromagnetic structures. It is important to estimate the distribution of magnetic field intensity for applicable magnetic methods relating to industrial nondestructive evaluation. A magnetic camera provides distribution of a quantitative magnetic field with a homogeneous lift-off and spatial resolution. It is possible to interpret the distribution of magnetic field when the dipole model was introduced. This study proposed an algorithm for nondestructive evaluation using dipole model analysis with a scan type magnetic camera. The numerical and experimental considerations of the quantitative evaluation of several sizes and shapes of cracks using magnetic field images of the magnetic camera were examined.

Lee, Jinyi; Hwang, Jiseong

2005-12-01

302

Electric transition dipole moment in pre-Born-Oppenheimer molecular structure theory.  

PubMed

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?u+1 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

Simmen, Benjamin; Mátyus, Edit; Reiher, Markus

2014-10-21

303

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

SciTech Connect

This paper discusses magnetic measurements and shimming performed on the ring dipoles and quadrupoles for the Los Alamos Proton Storage Ring (PSR). For the dipoles, point-by-point field maps were obtained using a search coil that could be scanned over a three-dimensional grid. By appropriate machining of removable end blocks, all magnet lengths were adjusted to within 0.01% of a nominal value and all integrated multipoles were set within tolerance. Integrated fields of 20 PSR quadrupoles were measured using a rotating ''Morgan Coil'' and a digital spectrum analyzer. The magnets were shimmed to specifications by adjusting steel bolts threaded through the field clamps. 3 refs., 5 figs., 4 tabs.

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

1985-01-01

304

40 mm bore Nb-Ti model dipole magnet  

SciTech Connect

Preliminary R and D has been started on magnets for a next-generation high-energy-physics accelerator, the 20 TeV Superconducting Supercollider (SSC). One design now being developed at LBL is described in this paper. The design is based on two layers of flattened Nb-Ti cable, a 40 mm ID winding with flared ends, and an operating field of 6.5 T. Experimental results are presented on several one-meter-long models tested at both He I and He II temperature. Measurement of field, residual magnetization, quench propagation velocity, and winding prestress are presented. (A 2-in-1 magnet based on this coil design is being jointly developed by LBL and Brookhaven National Laboratory, and 15 ft. long models are being constructed at BNL).

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

1984-09-10

305

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

SciTech Connect

Several 1 meter long, 40 mm aperture model SSC dipole magnets with vertically split yokes have been built and tested at Fermilab. In addition to the yoke design, these magnets were used to evaluate several variants of the collet clamps which apply prestress to the magnet ends. The magnets were instrumented with voltage taps for quench localization and strain gage based devices for measuring stresses, forces and deflections resulting from cooldown and excitation. Test were carried out in a vertical dewar at temperatures from 3.8{degree}K to 4.4{degree}K. The quench and mechanical behavior of these magnets will be presented and magnetic field measurements will be shown. A comparison with an earlier series of magnets with horizontally split yokes will be made. 7 refs., 4 figs., 1 tab.

Koska, W.; Bossert, R.; Coulter, K.J.; Delchamps, S.; Gourlay, S.; Kinney, W.; Jaffery, T.S.; Lamm, M.J.; Strait, J.; Wake, M.

1991-05-01

306

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

NASA Astrophysics Data System (ADS)

We introduce the Time Dependent Equivalent Source Dipole (TD-ESD) method developed with the purpose of modeling the Hermean magnetic field, taking into account the partial orbital coverage provided by MErcury Surface, Space ENvironment, Geochemistry, and Ranging (MESSENGER) mission. The TD-ESD method is based on the Equivalent Source Dipole approach, which has been largely used to downward or upward continue to constant altitude measurements of magnetic fields of crustal origin, on local or global scale. In this present application to Mercury, for which an internal core field is expected, the dipoles are uniformly distributed in a spherical shell placed deep into the planet's interior; their magnitude and direction are free to evolve with time. We ran several tests in order to validate the new method. We successfully recover the three components of the synthetic Hermean magnetic field. We also recover the temporal variation that we a priori imposed. Using synthetic data generated at MESSENGER orbit positions we find that downward and upward continuation is possible over a certain delimited region. When the dipole layer is placed at a depth of 640 km below the planet's surface, the resulting field is within 6% of the initial field model for altitudes ranging between -100km and 1500km. Here we present constant altitude magnetic field maps derived from MESSENGER measurements acquired during the first solar mercury year. We identify a strong signature of the external magnetic field, even when only measurements over the northern hemisphere below ~1000 km altitude are used. A future improvement of the method will consist in the simultaneous analysis of the external and internal magnetic fields.

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

2013-12-01

307

Electron Electric Dipole Moment and Hyperfine Interaction Constants for ThO  

E-print Network

A recently implemented relativistic four-component configuration interaction approach to study ${\\cal{P}}$- and ${\\cal{T}}$-odd interaction constants in atoms and molecules is employed to determine the electron electric dipole moment effective electric field in the $\\Omega=1$ first excited state of the ThO molecule. We obtain a value of $E_{\\text{eff}} = 75.6 \\left[\\frac{\\rm GV}{\\rm cm}\\right]$ with an estimated error bar of $3\\%$ and $10\\%$ smaller than a previously reported result [arXiv:1308.0414 [physics.atom-ph

Timo Fleig; Malaya K. Nayak

2014-01-10

308

Mercury intrinsic magnetic field : Limits of the offset-dipole representation  

NASA Astrophysics Data System (ADS)

The interaction of the solar wind (SW) with the magnetic field of The analysis of MESSENGER orbital observations led Anderson et al (2011) to propose a dipole centered on the spin axis of the planet with a northward offset equal to 484±11 km to represent the intrinsic magnetic field of Mercury at northern latitudes higher than 30°. The magnetic moment has a magnitude of 195±10nT, points southward and is tilted by less than 3° with respect to the spin axis. The restriction to northern latitude comes from the lack of low altitude measurements of the magnetic field at southern latitudes due to MESSENGER orbit. Hence for the moment being there is no observation to constrain the representation of the southern planetary field. The suggested offset is equal to about 20% of the planetary radius which is quite a large value by comparison to 8.5% in the terrestrial case although with a lateral offset. This representation of the intrinsic field by an offset dipole suggests that the southern polar cap should be much wider than the northern one, leading to important consequences for magnetospheric dynamics. Nevertheless the offset dipole is just a convenient representation that can be fitted by the first terms of the multipolar development. The surface field of the planet produced by the offset dipole (OD) proposed by Anderson et al (2011) is thus fitted by the sum of a dipolar and a quadrupolar field (DQ) for northern latitudes higher than 50°. The resulting field differs slightly from the offset dipole field at northern latitudes but a separatrix exists at southern latitudes between dipolar-like and quadrupolar like field lines. This separatrix begins on the polar axis at an altitude RS equal to three times the ratio of the quadrupolar to the dipolar moment. When the relative axial offset of the dipole becomes larger than 16% then RS becomes larger than the planetary radius leading to important topological changes of the southern field. Global hybrid simulations of the Hermean magnetosphere for the two models OD and DQ demonstrate that the southern magnetosphere produced by the DQ model differs greatly from what is expected using the OD model (Richer et al 2012). Reference: Anderson et al., Science, 333 , 1859, (2011) Richer, E., R. Modolo, G. M. Chanteur, S. Hess, and F. Leblanc (2012), A global hybrid model for Mercury's interaction with the solar wind: Case study of the dipole representation, J. Geophys. Res., 117, A10228, doi:10.1029/2012JA017898.

Chanteur, Gérard M.; Modolo, Ronan; Richer, Emilie; Hess, Sébastien; Leblanc, François

2013-04-01

309

Ground state magnetic dipole moment of 35K  

E-print Network

The ground state magnetic moment of 35K has been measured using the technique of nuclear magnetic resonance on beta-emitting nuclei. The short-lived 35K nuclei were produced following the reaction of a 36Ar primary beam of energy 150 MeV/nucleon incident on a Be target. The spin polarization of the 35K nuclei produced at 2 degrees relative to the normal primary beam axis was confirmed. Together with the mirror nucleus 35S, the measurement represents the heaviest T = 3/2 mirror pair for which the spin expectation value has been obtained. A linear behavior of gp vs. gn has been demonstrated for the T = 3/2 known mirror moments and the slope and intercept are consistent with the previous analysis of T = 1/2 mirror pairs.

T. J. Mertzimekis; P. F. Mantica; A. D. Davies; S. N. Liddick; B. E. Tomlin

2006-02-02

310

Electric and Magnetic Walls on Dielectric Interfaces  

E-print Network

Sufficient conditions of the existence of electric or magnetic walls on dielectric interfaces are given for a multizone uniform dielectric waveguiding system. If one of two adjacent dielectric zones supports a TEM field distribution while the other supports a TM (TE) field distribution, then the common dielectric interface behaves as an electric (magnetic) wall, that is, the electric (magnetic) field line is perpendicular to the interface while the magnetic (electric) field line is parallel to the interface.

Changbiao Wang

2010-07-20

311

Ferromagnetic material in the superconductor and its effect on the magnetization sextupole and decapole in the SSC dipoles at injection  

SciTech Connect

It has been shown that the magnetization of a multifilamentary superconductor can be altered by adding nickel to the composite strand. This report presents the results of calculations of the magnetization sextupole and higher multipoles in a five centimeter SSC dipole with and without nickel as part of the strand composite. The relative distribution of the nickel in the inner and outer coil conductors can be used to effectively eliminate sextupole and decapole at the SSC dipole injection field. Calculations of magnetization sextupole in the dipole are presented for strand with substituted nickel filaments and strand with electroplated nickel. The effect of nickel in the strand on the SSC dipole field quality at fields above the injection field is described. The effect of nickel in the strand on magnetization sextupole flux creep decay and the magnetization sextupole temperature dependence is also discussed. 11 refs., 7 figs., 1 tab.

Green, M.A. (Lawrence Berkeley Lab., CA (USA)); Collings, E.W.; Marken, K.R.; Sumption, M.D. (Battelle Columbus Div., OH (USA))

1991-03-01

312

Calculation of geometric phases in electric dipole searches with trapped spin-1/2 particles based on direct solution of the Schrödinger equation  

NASA Astrophysics Data System (ADS)

Pendlebury etal . [Phys. Rev. A 70, 032102 (2004), 10.1103/PhysRevA.70.032102] were the first to investigate the role of geometric phases in searches for an electric dipole moment (EDM) of elementary particles based on Ramsey-separated oscillatory field magnetic resonance with trapped ultracold neutrons and comagnetometer atoms. Their work was based on the Bloch equation and later work using the density matrix corroborated the results and extended the scope to describe the dynamics of spins in general fields and in bounded geometries. We solve the Schrödinger equation directly for cylindrical trap geometry and obtain a full description of EDM-relevant spin behavior in general fields, including the short-time transients and vertical spin oscillation in the entire range of particle velocities. We apply this method to general macroscopic fields and to the field of a microscopic magnetic dipole.

Steyerl, A.; Kaufman, C.; Müller, G.; Malik, S. S.; Desai, A. M.; Golub, R.

2014-05-01

313

Calculation of geometric phases in electric dipole searches with trapped spin-1/2 particles based on direct solution of the Schrödinger equation  

E-print Network

Pendlebury $\\textit{et al.}$ [Phys. Rev. A $\\textbf{70}$, 032102 (2004)] were the first to investigate the role of geometric phases in searches for an electric dipole moment (EDM) of elementary particles based on Ramsey-separated oscillatory field magnetic resonance with trapped ultracold neutrons and comagnetometer atoms. Their work was based on the Bloch equation and later work using the density matrix corroborated the results and extended the scope to describe the dynamics of spins in general fields and in bounded geometries. We solve the Schr\\"odinger equation directly for cylindrical trap geometry and obtain a full description of EDM-relevant spin behavior in general fields, including the short-time transients and vertical spin oscillation in the entire range of particle velocities. We apply this method to general macroscopic fields and to the field of a microscopic magnetic dipole.

A. Steyerl; C. Kaufman; G. Müller; S. S. Malik; A. M. Desai; R. Golub

2014-03-04

314

Determination of Mercury's magnetic dipole moment which fits the measurements taken during Mariner 10's flybys.  

NASA Astrophysics Data System (ADS)

Abstract. A new "Paraboloidal" model of Mercury's magnetospheric magnetic field based upon the earlier terrestrial model and using similar techniques is developed. The model describes field of Mercury's dipole, which is considered to be offset from the planet's centre, the magnetopause currents driven by the solar wind, and the tail current system including the cross-tail currents and their closure currents at the magnetopause. The effect of the interplanetary magnetic field (IMF) is modelled as a partial penetration of the IMF into the magnetosphere. The goals of the present work are: 1) to develop an easily usable, yet robust model of Mercury's magnetospheric magnetic field; and 2) to produce an improved "unified" determination of Mercury's magnetic dipole moment which fits the measurements taken during both Mariner 10's first and third flybys. This new model of Mercury's magnetosphere is described and used to determine a best Mercury magnetic dipole moment of 240 nT RM 3, from the two Mariner 10 flybys; a value which is intermediate between the various estimates produced by previous models. Best fit gives the dipole offset up to 0.1 RM above the equatorial plane. In preparation for the up-coming Mercury fly-bys by the MESSENGER mission this new Paraboloidal model is used to predict the configuration of this miniature magnetosphere under average and extreme solar wind conditions. EPSC Abstracts, Vol. 3, EPSC2008-A-00054, 2008 European Planetary Science Congress, Author(s) 2008 A new model of Mercury's global magnetospheric current systems has been developed based upon the Paraboloidal Model which has been successfully applied previously to the Earth , Jupiter, and Saturn. Using this model we have re-examined the Mariner 10 observations taking into account the IMF penetration into the magnetosphere and the global magnetospheric currents at the time of each encounter. The magnetospheric current model includes the magnetopause current that confines the planet's magnetic field to the magnetosphere and the tail current system consisting of the cross-tail current sheet and the closure currents at the magnetopause. Under the assumption that the solar wind interaction with Mercury is terrestrial in character, it was shown that the contribution of the external current systems into the total magnetic field in the vicinity of Mercury is significant even at the planet's surface. Determination of a rotation axis-aligned magnetic dipole moment value, 240 nT Rm 3, that is consistent with both of the Mariner 10's close encounters is one of achievements of the present work. We received some evidence for the dipole offset up to 0.1 Rm in northward direction, but more accurate calculations of the dipole position will require an additional study. Comparison of the model calculations with observation data obtained during the Mariner 10 MI and MIII flybys shows the important role which IMF plays in the Mercury's magnetosphere. Analysis of magnetic field measurements gives indirect indication that the coefficient of the IMF penetration into the Hermean magnetosphere is much larger than at the Earth and may approach unity when the upstream IMF is southward. This result supports earlier suggestions that magnetic reconnection between the planetary magnetic field and the IMF may be much more efficient at Mercury as compared to the Earth due to the lower Alfven Mach numbers found in the inner heliosphere.

Alexeev, I. I.; Belenkaya, E. S.; Bobrovnikov, S. Yu.; Slavin, J. A.; Sarantos, M.

2008-09-01

315

Recent improvements in superconducting cable for accelerator dipole magnets  

SciTech Connect

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

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

1991-05-01

316

Electric Dipole Moments of Light Nuclei and the Implications for CP Violation  

NASA Astrophysics Data System (ADS)

A definitive measurement of an electric dipole moment (EDM) would likely imply new physics beyond the standard model. Although the standard model strong interaction term could theoretically produce an EDM of any size, that it is constrained by the current neutron EDM limit to be some 10 orders of magnitude smaller than 1 suggests that the electroweak sector and CP violation will be the source of a measurable EDM. The weak interaction standard model EDM is itself orders of magnitude smaller than contemporary experiments can measure. Direct measurement of the neutron EDM lies in the next decade; measurement of the proton EDM could well come first. A BNL proposal for an electrostatic storage ring measurement lies in the offing. Unless the EDM proves to be an isoscalar, one will need other measurements to separate the isoscalar, isovector, and isotensor components. Measurement of a nuclear EDM will be required: 2H, 3H, or 3He being the simplest nuclear systems. A storage ring measurement of the triton EDM could be accomplished in a manner analogous to that proposed for the proton. However, the deuteron EDM measurement offers certain advantages, even though the experiment would be more complex, involving electric and magnetic fields, than that required for the proton and triton. The COSY facility in the Forschungszentrum Juelich is almost an ideal facility to house such an experiment; one could also measure in the same ring the EDM for the proton and He. The deuteron is the one nucleus for which exact model calculations can easily be performed. We briefly explore the model dependence of deuteron EDM calculations. Using a separable potential formulation of the Hamiltonian, we examine the sensitivity of the deuteron EDM to variations in the nucleon-nucleon interaction, including contemporary potential models, and we explore the dependence upon intermediate state multiple scattering in the 3P1 channel. We investigate the tensor force contribution to the model results and examine the effects of short-range repulsion that characterize realistic, contemporary potential models of the deuteron. Because one-pion exchange dominates the EDM calculation, separable potential model calculations appear to provide an adequate description of the deuteron EDM until such time as a measurement of better than 10 % is achieved.

Gibson, B. F.; Afnan, I. R.

2013-03-01

317

Constraints on light magnetic dipole dark matter from the ILC and SN 1987A  

NASA Astrophysics Data System (ADS)

To illustrate the complementarity of the linear collider and astrophysics bounds on the light (MeV-scale mass) dark matter (DM), we study the constraints on the magnetic dipole DM from the DM-electron interactions at the proposed International Linear Collider (ILC) and in supernova (SN) 1987A. We in particular focus on the e+e- annihilation, which is the common process for producing DM pairs both at the ILC and in the SN. We estimate the bounds on the DM magnetic dipole moment from the monophoton signals at the ILC and also from the energy loss rate due to the freely streaming DM produced in the SN. The SN bounds can be more stringent than those from the ILC by as much as a factor O(105) for a DM mass below 102 MeV. For larger DM masses, on the other hand, SN rapidly loses its sensitivity and the collider constraints can complement the SN constraints.

Kadota, Kenji; Silk, Joseph

2014-05-01

318

New measurements of magnetic field decay in 1 meter SSC-type dipoles  

SciTech Connect

Previous studies of magnetic field decay in model SSC dipoles due to changes in magnetization currents caused by flux creep have used the assumed SSC injection energy of 1 TeV, or 0.33 tesla central dipole field, and an excitation to the storage field of 6.6 tesla. More recently, it has been decided to inject at 2 TeV, or 0.66 tesla and so more recent tests have been carried out at the new injection field, or at both the new and old fields. Additionally, the effect of temperature changes and excitation cycles on the field decay have been studied. 6 refs., 11 figs., 2 tabs.

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

1990-09-01

319

Real-Time Localization of Moving Dipole Sources for Tracking Multiple Free-Swimming Weakly Electric Fish  

PubMed Central

In order to survive, animals must quickly and accurately locate prey, predators, and conspecifics using the signals they generate. The signal source location can be estimated using multiple detectors and the inverse relationship between the received signal intensity (RSI) and the distance, but difficulty of the source localization increases if there is an additional dependence on the orientation of a signal source. In such cases, the signal source could be approximated as an ideal dipole for simplification. Based on a theoretical model, the RSI can be directly predicted from a known dipole location; but estimating a dipole location from RSIs has no direct analytical solution. Here, we propose an efficient solution to the dipole localization problem by using a lookup table (LUT) to store RSIs predicted by our theoretically derived dipole model at many possible dipole positions and orientations. For a given set of RSIs measured at multiple detectors, our algorithm found a dipole location having the closest matching normalized RSIs from the LUT, and further refined the location at higher resolution. Studying the natural behavior of weakly electric fish (WEF) requires efficiently computing their location and the temporal pattern of their electric signals over extended periods. Our dipole localization method was successfully applied to track single or multiple freely swimming WEF in shallow water in real-time, as each fish could be closely approximated by an ideal current dipole in two dimensions. Our optimized search algorithm found the animal’s positions, orientations, and tail-bending angles quickly and accurately under various conditions, without the need for calibrating individual-specific parameters. Our dipole localization method is directly applicable to studying the role of active sensing during spatial navigation, or social interactions between multiple WEF. Furthermore, our method could be extended to other application areas involving dipole source localization. PMID:23805244

Jun, James Jaeyoon; Longtin, Andre; Maler, Leonard

2013-01-01

320

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

SciTech Connect

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

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

2011-03-28

321

Future Muon Dipole Moment Measurements  

E-print Network

From the famous experiments of Stern and Gerlach to the present, measurements of magnetic dipole moments, and searches for electric dipole moments of ``elementary'' particles have played a major role in our understanding of sub-atomic physics. In this talk I discuss the progress on measurements and theory of the magnetic dipole moment of the muon. I also discuss a new proposal to search for a permanent electric dipole moment (EDM) of the muon and put it into the more general context of other EDM searches. These experiments, along with searches for the lepton flavor violating decays $\\mu \\to e \\gamma$ and $\\mu^- + A \\to e^- + A$, provide a path to the high-energy frontier through precision measurements.

B. Lee Roberts

2004-12-12

322

Exotic-atom measurement of the magnetic dipole moment of the Sigma hyperon  

Microsoft Academic Search

The magnetic dipole moment of the Sigma- hyperon has been determined from Sigma--atom x-ray transitions in natural lead and tungsten. Negative kaons were stopped in a target which consisted of sheets of W or Pb immersed in liquid hydrogen. The Sigma- resulting from the reaction K-p-->Sigma-pi+ were tagged by observing the monoenergetic pi+. X rays from Sigma- atoms were detected

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

1988-01-01

323

The role of magnetic dipoles and non-zero-order Bragg waves in metamaterial perfect absorbers.  

PubMed

We develop a simple treatment of a metamaterial perfect absorber (MPA) based on grating theory. We analytically prove that the condition of MPA requires the existence of two currents, which are nearly out of phase and have almost identical amplitude, akin to a magnetic dipole. Furthermore, we show that non-zero-order Bragg modes within the MPA may consume electromagnetic energy significantly. PMID:23481811

Zeng, Yong; Chen, Hou-Tong; Dalvit, Diego A R

2013-02-11

324

Theory of global thermoremanent magnetization of planetary lithospheres in dipole fields of internal origin  

NASA Technical Reports Server (NTRS)

A model is presented for the global thermoremanent magnetization of spherical lithospheres which cool in the presence of central dipole fields. Reversals and intensity variations of the field are incorporated in this model, which is applicable to bodies whose interiors have remained above the Curie point throughout their evolution. The model demonstrates that even considering Runcorn's (1975) magnetostatics theorems for spherical shells, a nonzero magnetic permeability and a finite cooling rate in the lithosphere permit the acquisition of a sizable global remanent dipole moment, which would be detectable by external measurements after the magnetizing field has disappeared. Preliminary application of this model to Mercury, Venus, and Mars suggests that only the combination of a nonreversing ancient source field with a surface value near 1 Oe plus a sizable concentration (about 1% by volume) of ferromagnetic material in their crusts could produce remanent planetary dipole fields as large as those measured by spacecraft. On the other hand, if ancient reversing dynamos existed in these planets, it is unlikely that large planetary-scale fields like those observed at Mercury could be due to remanence in their crusts, irrespective of their composition.

Srnka, L. J.; Mendenhall, M. H.

1979-01-01

325

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

SciTech Connect

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

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

2005-09-01

326

Tests of Fermilab built 40 mm aperture full length SSC dipole magnets  

SciTech Connect

Several 40 mm aperture, 17 m long dipoles have been built by Fermilab as developmental prototypes for the Superconducting Super Collider. These magnets differ from those manufactured at Brookhaven National Laboratory in that they have an external inner-outer coil splice design, a collet style end clamp assembly, a new, analytically designed minimum stress coil end design, and a new insulation system which does not employ shims or shoes''. In addition, the magnets were built using production-style tooling. The magnets were tested at the Fermilab Magnet Testing Facility. Quench testing and mechanical measurement results are presented and analyzed with emphasis on the new design and fabrication features of these magnets. 13 refs., 5 figs.

Koska, W.; Bleadon, M.; Bossert, R.; Carson, J.; Delchamps, S.; Gourlay, S.; Hanft, R.; Kuchnir, M.; Lamm, M.J.; Mantsch, P.; Mazur, P.O.; Orris, D., Strait, J.; Wake, M. (Fermi National Accelerator Lab., Batavia, IL (United States)); Bush, T.; Coombes, R.; Devred, A.; DiMarco, J.; Goodzeit, C.; Kuzminski, J.; Ogitsu, T.; Puglisi, M.; Radusewicz, P.; Schermer, R.; Tompkins, J.C.; Wolf, Z.; Yu, Y.; Zheng, H. (Superconduct

1991-09-01

327

Mechanical analysis of the Nb3Sn dipole magnet HD1  

SciTech Connect

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.

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

328

Mechanical Analysis of the Nb3Sn Dipole Magnet HD1  

SciTech Connect

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.

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

329

Magnetic dipole excitations in nuclei: Elementary modes of nucleonic motion  

SciTech Connect

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 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, 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.

Heyde, Kris; Neumann-Cosel, Peter von; Richter, Achim [Department of Subatomic and Radiation Physics, University of Gent, Proeftuinstraat 86, B-9000 Gent (Belgium); Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstad (Germany) and ECT, Villa Tambosi, I-38123 Villazzano, Trento (Italy)

2010-07-15

330

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

SciTech Connect

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

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

1991-06-01

331

Theoretical study of HfF{sup +} in search of the electron electric dipole moment  

SciTech Connect

We report ab initio relativistic correlation calculations of potential curves for ten low-lying electronic states, the effective electric field on the electron, and hyperfine constants for the {sup 3}{delta}{sub 1} state of a cation of the heavy transition metal fluoride HfF{sup +}, which it is suggested can be used in experiments to search for the electric dipole moment of the electron. It is shown that HfF{sup +} has a deeply bound {sup 1}{sigma}{sup +} ground state; its dissociation energy is D{sub e}=6.4 eV. The {sup 3}{delta}{sub 1} state is obtained as the relatively long-lived first excited state lying about 0.2 eV higher. The calculated effective electric field E{sub eff}=W{sub d}|{omega}| acting on an electron in this state is 5.84x10{sup 24} Hz/e cm.

Petrov, A. N.; Mosyagin, N. S.; Isaev, T. A.; Titov, A. V. [Petersburg Nuclear Physics Institute, Gatchina, Leningrad district 188300 (Russian Federation)

2007-09-15

332

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

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

333

Electron electric dipole moment as a sensitive probe of PeV scale physics  

NASA Astrophysics Data System (ADS)

We give a quantitative analysis of the electric dipole moments as a probe of high scale physics. We focus on the electric dipole moment of the electron since the limit on it is the most stringent. Further, theoretical computations of it are free of QCD uncertainties. The analysis presented here first explores the probe of high scales via electron electric dipole moment (EDM) within minimal supersymmetric standard model where the contributions to the EDM arise from the chargino and the neutralino exchanges in loops. Here it is shown that the electron EDM can probe mass scales from tens of TeV into the PeV range. The analysis is then extended to include a vectorlike generation which can mix with the three ordinary generations. Here new CP phases arise and it is shown that the electron EDM now has not only a supersymmetric (SUSY) contribution from the exchange of charginos and neutralinos but also a nonsupersymmetric contribution from the exchange of W and Z bosons. It is further shown that the interference of the supersymmetric and the nonsupersymmetric contribution leads to the remarkable phenomenon where the electron EDM as a function of the slepton mass first falls and become vanishingly small and then rises again as the slepton mass increases. This phenomenon arises as a consequence of cancellation between the SUSY and the non-SUSY contribution at low scales while at high scales the SUSY contribution dies out and the EDM is controlled by the non-SUSY contribution alone. The high mass scales that can be probed by the EDM are far in excess of what accelerators will be able to probe. The sensitivity of the EDM to CP phases both in the SUSY and the non-SUSY sectors are also discussed.

Ibrahim, Tarek; Itani, Ahmad; Nath, Pran

2014-09-01

334

Remarks on ``New experimental limit on the electric dipole moment of the neutron''  

NASA Astrophysics Data System (ADS)

A new limit for the neutron electric dipole moment has been recently reported. This new limit is obtained by combining the result from a previous experiment with the result from a more recent experiment that has much worse statistical accuracy. We show that the old result has a systematic error possibly four times greater than the new limit, and under the circumstances, averaging of the old and new results is statistically invalid. The conclusion is that it would be more appropriate to quote two independent but mutually supportive limits as obtained from each experiment separately.

Lamoreaux, S. K.; Golub, R.

2000-03-01

335

Measurement of the neutron electric dipole moment via spin rotation in a non-centrosymmetric crystal  

E-print Network

We have measured the neutron electric dipole moment using spin rotation in a non-centrosymmetric crystal. Our result is d_n = (2.5 +- 6.5(stat) +- 5.5(syst)) 10^{-24} e cm. The dominating contribution to the systematic uncertainty is statistical in nature and will reduce with improved statistics. The statistical sensitivity can be increased to 2 10^{-26} e cm in 100 days data taking with an improved setup. We state technical requirements for a systematic uncertainty at the same level.

V. V. Fedorov; M. Jentschel; I. A. Kuznetsov; E. G. Lapin; E. Lelievre-Berna; V. Nesvizhevsky; A. Petoukhov; S. Yu. Semenikhin; T. Soldner; V. V. Voronin; Yu. P. Braginetz

2010-09-01

336

New concept for a neutron electric dipole moment search using a pulsed beam  

NASA Astrophysics Data System (ADS)

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.

Piegsa, Florian M.

2013-10-01

337

Additional two-loop contributions to electric dipole moments in supersymmetric theories  

E-print Network

We calculate the two-loop contributions to the electric dipole moments of the electron and the neutron mediated by charged Higgs in a generic supersymmetric theories. The new contributions are originated from the potential CP violation in the trilinear couplings of the charged Higgs bosons to the scalar-top or the scalar-bottom quarks. These couplings did not receive stringent constraints directly. We find observable effects for a sizeable portion of the parameter space related to the third generation scalar-quarks in the minimal supersymmetric standard model.

Darwin Chang; We-Fu Chang; Wai-Yee Keung

1999-10-24

338

Electric dipole moments as probes of new CP-odd physics  

NASA Astrophysics Data System (ADS)

We review the importance of precision probes for flavor-diagonal CP-violation, specifically searches for electric dipole moments of nucleons, atoms and molecules, in accessing new CP-odd physics at high scales. We summarize the effective field theory analysis of observable EDMs in terms of a general set of CP-odd operators at 1 GeV, and the ensuing model-independent new physics constraints, incorporating the recently improved limit on the Hg EDM. We also discuss the current status of these limits in the context of 1- and 2-loop contributions in supersymmetric models.

Ritz, Adam

2009-12-01

339

Search for the Neutron Electric Dipole Moment at the SNS at Oak Ridge  

NASA Astrophysics Data System (ADS)

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 2.9×10-26 e cm.

Kolarkar, Ameya

2010-02-01

340

SQUIDs as Detectors in a New Experiment to Measure the Neutron Electric Dipole Moment  

SciTech Connect

A new experiment has been proposed at Los Alamos National Laboratory to measure the neutron electric dipole moment (EDM) to 4x10{sup {minus}28} ecm, a factor of 250 times better than the current experimental limit. Such a measure of the neutron EDM would challenge the theories of supersymmetry and time reversal violation as the origin of the observed cosmological asymmetry in the ratio of baryons to antibaryons. One possible design for this new experiment includes the use of LTC SQUIDs coupled to large ({approximately}100 cm{sup 2}) pick-up coils to measure the precession frequency of the spin-polarized {sup 3}He atoms that act as polarizer, spin analyzer, detector, and magnetometer for the ultra-cold neutrons used in the experiment. The method of directly measuring the {sup 3}He precession signal eliminates the need for very uniform magnetic fields (a major source of systematic error in these types of experiments). It is estimated that a flux of {approximately}2x10{sup {minus}16} Tm{sup 2} (0.1 F{sub 0}) will be coupled into the pick-up coils. To achieve the required signal-to-noise ratio one must have a flux resolution of d F{sub SQ}=2x10{sup {minus}6} F{sub 0}/{radical}Hz at 10 Hz. While this is close to the sensitivity available in commercial devices, the effects of coupling to such a large pick-up coil and flux noise from other sources in the experiment still need to be understood. To determine the feasibility of using SQUIDs in such an application we designed and built a superconducting test cell, which simulates major features of the proposed EDM experiment, and we developed a two-SQUID readout system that will reduce SQUID noise in the experiment. We present an overview of the EDM experiment with SQUIDs, estimations of required SQUID parameters and experimental considerations. We also present the measured performance of a single magnetometer in the test cell as well as the performance of the two SQUID readout technique

Espy, M.A.; Cooper, M.; Lamoreaux, S.; Kraus, R.H., Jr.; Matlachov, A.; Ruminer, P.

1998-09-13

341

SQUIDs as detectors in a new experiment to measure the neutron electric dipole moment  

SciTech Connect

A new experiment has been proposed at Los Alamos National Laboratory to measure the neutron electric dipole moment (EDM) to 4{times}10{sup {minus}28} ecm, a factor of 250 times better than the current experimental limit. Such a measure of the neutron EDM would challenge the theories of supersymmetry and time reversal violation as the origin of the observed cosmological asymmetry in the ratio of baryons to antibaryons. One possible design for this new experiment includes the use of LTC SQUIDs coupled to large ({approximately}100 cm{sup 2}) pick-up coils to measure the precision frequency of the spin-polarized {sup 3}He atoms that act as polarizer, spin analyzer, detector, and magnetometer for the ultra-cold neutrons used in the experiment. The method of directly measuring the {sup 3}He precession signal eliminates the need for very uniform magnetic fields (a major source of systematic error in these types of experiments). It is estimated that a flux of {approximately}2{times}10{sup {minus}16} Tm{sup 2} (0.1 {Phi}{sub 0}) will be coupled into the pick-up coils. To achieve the required signal-to-noise ratio one must have a flux resolution of d{Phi}{sub SQ} = 2{times}10{sup {minus}6}{Phi}{sub 0}/{radical}Hz at 10 Hz. While this is close to the sensitivity available in commercial devices, the effects of coupling to such a large pick-up coil and flux noise from other sources in the experiment still need to be understood. To determine the feasibility of using SQUIDs in such an application the authors designed and built a superconducting test cell, which simulates major features of the proposed EDM experiment, and they developed a two-SQUID readout system that will reduce SQUID noise in the experiment. They present an overview of the EDM experiment with SQUIDs, estimations of required SQUID parameters and experimental considerations. The authors also present the measured performance of a single magnetometer in the test cell as well as the performance of the two SQUID readout technique.

Espy, M.A.; Cooper, M.; Lamoreaux, S.; Kraus, R.H. Jr.; Matlachov, A.; Ruminer, P.

1998-12-31

342

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

343

2D Magnetic Design and Optimization of a 88-mm Aperture 15 T Dipole for NED  

E-print Network

The Next European Dipole (NED) activity supported by the European Union aims at the development of a high-performance Nb3Sn conductor ( c = 1500A mm 2 @15 T, 4.2 K) in collaboration with European industry and at the design of a highfield dipole magnet making use of this conductor. In the framework of the NED collaboration which coordinates the activity of several institutes,CERNhas contributed to the electromagnetic design study of a cos , layer-type superconducting dipole with an 88 mm aperture that is able to reach 15 T at 4.2 K. Part of the optimization process was dedicated to the reduction of the multipole coefficients so as to improve field quality while keeping an efficient peak-field to main-field ratio. In this paper, we present the optimization of the coil cross-section and of the shape of the iron yoke to reduce saturation-induced field errors during ramp. The effects of persistent magnetization currents are also estimated and different methods to compensate persistent-current-induced field distort...

Schwerg, N; Devred, A; Leroy, D

2007-01-01

344

Performance analysis of HD1: a 16 Tesla Nb3Sn dipole Magnet  

SciTech Connect

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

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

2005-06-01

345

HD1: Design and Fabrication of a 16 Tesla Nb3Sn Dipole Magnet  

SciTech Connect

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.

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

346

HD1: Design and Fabrication of a 16 Tesla Nb3Sn DipoleMagnet  

SciTech Connect

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

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

2003-11-10

347

Taming molecular collisions using electric and magnetic fields.  

PubMed

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

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

2014-11-01

348

Design and development of Nb{sub 3}Sn single-layer common coil dipole magnet for VLHC  

SciTech Connect

Common coil dipole magnets based on Nb{sub 3}Sn 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 in terms of cable insulation, structural materials and magnet fabrication. A common coil design allows the use of pre-reacted Nb{sub 3}Sn superconductor with low critical current degradation after bending. Fermilab in collaboration with LBNL is involved in the development of a single-layer common-coil dipole magnet with maximum field of 11 T and 40-50 mm aperture, for a future VLHC. The current magnetic and mechanical designs of the dipole model, magnet parameters along with the status of the program, are reported in this paper.

Giorgio Ambrosio et al.

2001-07-30

349

A Relativistic Many-Body Analysis of the Electric Dipole Moment of $^{223}$Rn  

E-print Network

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-...

Sahoo, B K; Das, B P

2014-01-01

350

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

NASA Astrophysics Data System (ADS)

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

Maiezza, Alessio; Nemevšek, Miha

2014-11-01

351

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

E-print Network

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

Steve K. Lamoreaux

2007-01-17

352

Dipole moment of a small water cluster. The effect of size, temperature, and electric field  

NASA Astrophysics Data System (ADS)

A molecular dynamics simulation of neutral clusters (H2O) n ? 21 has been performed in the framework of the flexible polarized model. The formation and evolution of the dipole moment of the cluster have been investigated with a change in the size and temperature of the cluster and an external electric field. It has been shown that at low electric fields corresponding to the experiments on the deflection of clusters in the transverse inhomogeneous electrostatic field (Moro et al., 2006), the induced polarization of the cluster is determined by the orientational polarizability of the “rigid” cluster, rather than by the intracluster reorientation of the molecules. The calculated dependence of the effective polarizability of the cluster in the low field on n qualitatively reproduces the experimental results, but the calculated polarizability is numerically much higher than the experimental value by, e.g., a factor of 4 for n ? 20.

Dubov, D. Yu.; Vostrikov, A. A.

2010-07-01

353

Combined Panofsky Quadrupole & Corrector Dipole  

SciTech Connect

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

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

2007-07-02

354

Unusual electric response of the dislocations and the impurity dipoles in KNbO3 single crystals  

NASA Astrophysics Data System (ADS)

A highly unusual electric response of the dislocations and the impurity dipoles in KNbO3 single crystals has been found. The etch pits representing these defects move in the structure carrying these defects with them. This shows that the defects have associated with them structural units that are orders of magnitude larger in physical size. Naturally these units are also associated with stress fields and electric effects on account of the ferroelectric nature of the crystal. The nature of the stress fields could be determined by studying the movement of the etch pits in response to the externally applied electric fields. It is found that the impurity dipoles in the observed pseudocubic (001) surface have stress fields similar to those of screw dislocations, and the dipoles in the front and side faces have stress fields similar to those of edge dislocations. The external dc field causes rotation of the dislocation loops and, hence, changes the domain structure. It may order or disorder the dislocations, the effect being reversible. Similar effects have been observed for impurity dipoles. Several consequences of the stress fields have been considered theoretically and observed experimentally. For example, the stress fields of impurity dipoles and dislocation loops lead to their mutual exclusion. Hence, at a given place in the crystal the domain structure is nucleated either by the dislocation loops or by the impurity dipoles. The conjoint domain nucleation, sometimes possible by an impurity dipole and a dislocation loop worked out on theoretical considerations, agrees with experimental observation. Large distance mutual interaction, bulk ordering, dependence of bulk ordering on the density of defects, and domain nucleation have all been explained on the basis of the structural units associated with the impurity dipoles and the dislocation loops.

Ingle, S. G.; Kakde, R. N.

1995-07-01

355

Calculation of P,T-odd electric dipole moments for diamagnetic atoms $^{129}$Xe, $^{171}$Yb, $^{199}$Hg, $^{211}$Rn, and $^{225}$Ra  

E-print Network

Electric dipole moments of diamagnetic atoms of experimental interest are calculated using the relativistic Hartree-Fock and random-phase approximation methods, the many-body perturbation theory and configuration interaction technique. We consider P,T-odd interactions which give rise to atomic electric dipole moment in the second order of the perturbation theory. These include nuclear Schiff moment, P,T-odd electron-nucleon interaction and electron electric dipole moment. Interpretation of a new experimental constraint of a permanent electric dipole moment of $^{199}$Hg [W. C. Griffith {\\it et al.}, Phys. Rev. Lett. {\\bf 102}, 101601 (2009)] is discussed.

V. A. Dzuba; V. V. Flambaum; S. G. Porsev

2009-06-30

356

Magnetic dipole with a flexible tail as a self-propelling microdevice  

NASA Astrophysics Data System (ADS)

By numerical simulations, it is illustrated that a magnetic dipole with a flexible tail behaves as a swimmer in AC magnetic fields. The behavior of the swimmer on long time scales is analyzed and it is shown that due to the flexibility of the tail two kinds of torques arise, the first is responsible for the orientation of the swimmer perpendicularly to the AC field and the second drags the filament in the direction of the rotating field. Due to this, circular trajectories of the swimmer are possible; however, these are unstable. The self-propulsion velocity of this swimmer is higher than the velocities of other magnetic microdevices for comparable values of the magnetoelastic number.

Livanovi?s, R?dolfs; C?bers, Andrejs

2012-04-01

357

Magnetic dipole with a flexible tail as a self-propelling microdevice.  

PubMed

By numerical simulations, it is illustrated that a magnetic dipole with a flexible tail behaves as a swimmer in AC magnetic fields. The behavior of the swimmer on long time scales is analyzed and it is shown that due to the flexibility of the tail two kinds of torques arise, the first is responsible for the orientation of the swimmer perpendicularly to the AC field and the second drags the filament in the direction of the rotating field. Due to this, circular trajectories of the swimmer are possible; however, these are unstable. The self-propulsion velocity of this swimmer is higher than the velocities of other magnetic microdevices for comparable values of the magnetoelastic number. PMID:22680478

Livanovi?s, R?dolfs; C?bers, Andrejs

2012-04-01

358

Bipolarity Without Binarity: AGB Winds, Dipole Magnetic Fields, and Disk Formation  

NASA Astrophysics Data System (ADS)

We present a simple, robust mechanism for producing an equatorially concentrated wind (excretion disk) from a non-rotating AGB or post-AGB star. This equatorial density enhancement (existing in a slow wind) presents an aspherical inertial barrier to subsequent fast, isotropic winds that may occur. Such a barrier may act as a nozzle for producing the axisymmetric (elliptical or bipolar) morphologies exhibited by many PNe without invoking merging binary systems or surface rotation near breakup. In the presented model, the star initially has a dipole magnetic field that is inflated by the wind to become mostly radial but oppositely directed above and below the equator. The interaction between the wind plasma and magnetic field produce a steady-state outflow in which magnetic forces direct plasma toward the equator. We also present the results of MHD simulations that confirm the model.

Matt, S.; Balick, B.; Winglee, R.; Goodson, A.

2000-05-01

359

Recoil velocity of pulsar/magnetar induced by magnetic dipole and quadrupole radiation  

NASA Astrophysics Data System (ADS)

Recoil velocity is examined as a back reaction to the magnetic dipole and quadrupole radiations from a pulsar/magnetar born with rapid rotation. The model is extended from notable Harrison-Tademaru one by including arbitrary field-strength of the magnetic quadrupole moment. The process is slow one operating on a spindown timescale. Resultant velocity depends on not the magnitude, but rather the ratio of the two moments and their geometrical configuration. The model does not necessarily lead to high spatial velocity for a magnetar with a strong magnetic field. This fact is consistent with the recent observational upper bound. The maximum velocity predicted with this model is slightly smaller than that of observed fast-moving pulsars.

Kojima, Yasufumi

2013-03-01

360

Quench problems of Nb3 Sn cosine theta high field dipole model magnets  

SciTech Connect

We have developed and tested several cosine theta high field dipole model magnets for accelerator application, utilizing Nb{sub 3}Sn 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 6.8 Tesla at 4.5 K due to cryo-instability. Typical quench behaviors of these magnets are described for both types of magnets, HFDA-04 of MJR and HFDA-05 of PIT. Their characteristics parameters are compared on d{sub eff}, RRR, thermal conductivity and others, together with other historical Nb{sub 3}Sn magnets. It is suggested a larger RRR value is essential for the stability of the epoxy impregnated high field magnets made with high current density strands. It is shown that a magnet with a larger RRR value has a longer MPZ value and more stable, due to its high thermal conductivity and low resistivity.

Yamada, Ryuji; /Fermilab; Wake, Masayoshi; /KEK, Tsukuba

2004-12-01

361

Limits on the neutrino magnetic dipole moment from the luminosity function of hot white dwarfs  

E-print Network

Recent determinations of the white dwarf luminosity function (WDLF) from very large surveys have extended our knowledge of the WDLF to very high luminosities. This, together with the availability of new full evolutionary white dwarf models that are reliable at high luminosities, have opened the possibility of testing particle emission in the core of very hot white dwarfs, where neutrino processes are dominant. We use the available WDLFs from the Sloan Digital Sky Survey and the SuperCOSMOS Sky Survey to constrain the value of the neutrino magnetic dipole moment ($\\mu_\

Marcelo Miguel Miller Bertolami

2014-07-05

362

Magnetic dipole moments of odd-odd N=Z nuclei  

Microsoft Academic Search

The experimental data of the magnetic dipole moments of low-lying states in odd-odd N=Z nuclei, which has increased recently by a factor of 2, are revisited within the simple shell model, taking the wave functions to be of the form Psicore(J=0,T=0)Psinp(J,T=0). Good agreement with the updated experimental data is obtained within the jj-coupling scheme Psinp[(nlj)2J,(T=0)], using the Schmidt values for

Yigal Ronen; Shalom Shlomo

1998-01-01

363

Reconstructing supersymmetric contribution to muon anomalous magnetic dipole moment at ILC  

NASA Astrophysics Data System (ADS)

We study the possibility to determine the supersymmetric (SUSY) contribution to the muon anomalous magnetic dipole moment by using ILC measurements of the properties of superparticles. Assuming that the contribution is as large as the current discrepancy between the result of the Brookhaven E821 experiment and the standard-model prediction, we discuss how and how accurately the SUSY contribution can be reconstructed. We will show that, in a sample point, the reconstruction can be performed with the accuracy of ?13% with the center-of-mass energy 500 GeV and the integrated luminosity ?500-1000 fb.

Endo, Motoi; Hamaguchi, Koichi; Iwamoto, Sho; Kitahara, Teppei; Moroi, Takeo

2014-01-01

364

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

E-print Network

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

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

2009-06-16

365

A D-He/sup 3/ fusion reactor based on a dipole magnetic field  

SciTech Connect

An innovative fusion reactor suitable for D-He/sup 3/ fuel is proposed, based on a dipole magnetic field produced by a simple one-turn coil with /approx lt/16 T near-field intensity. The equilibrium plasma, phase-space density satisfies /partial derivative//cflx f//sub 0/(/mu/, J, /psi/)//partial derivative//psi/ = O, where /psi/ is the flux function, has a steep enough pressure profile for an efficient fusion reaction yet is stable for low frequency instabilities to local beta exceeding unity. The semi-open field configuration is particularly suitable for D-He/sup 3/ reactions. 8 refs., 1 fig.

Hasegawa, Akira; Chen, Liu

1989-07-01

366

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

SciTech Connect

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

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

2013-06-15

367

Generation of Electric and Magnetic Fields During Detonation of High Explosive Charges in Boreholes  

SciTech Connect

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.

Soloviev, S; Sweeney, J

2004-06-04

368

Tentative Detection of Electric Dipole Emission from Rapidly Rotating Dust Grains  

E-print Network

We present the first tentative detection of spinning dust emission from specific astronomical sources. All other detections in the current literature are statistical. The Green Bank 140 foot telescope was used to observe 10 dust clouds at 5, 8, and 10 GHz. In some cases, the observed emission was consistent with the negative spectral slope expected for free-free emission (thermal bremsstrahlung), but in two cases it was not. One HII region yields a rising spectrum, inconsistent with free-free or synchrotron emission at the 10 sigma level. One dark cloud (L 1622) has a similar spectrum with lower significance. Both spectra are consistent with electric dipole emission from rapidly rotating dust grains ("spinning dust"), as predicted by Draine & Lazarian.

Douglas P. Finkbeiner; David J. Schlegel; Curtis Frank; Carl Heiles

2001-09-27

369

Distinguishing axions from generic light scalars using electric dipole moment and fifth-force experiments  

NASA Astrophysics Data System (ADS)

We derive electric dipole moment (EDM) constraints on possible new macroscopic time-reversal and parity-violating (TVPV) spin-dependent forces. These constraints are compared to those derived from direct searches in fifth-force experiments and from combining laboratory searches with astrophysical bounds on stellar energy loss. For axion-mediated TVPV spin-dependent forces, EDM constraints dominate over fifth-force limits by several orders of magnitude. However, we show that for a generic light scalar, unrelated to the strong CP problem, present bounds from direct fifth-force searches are more stringent than those inferred from EDM limits for the interaction ranges explored by fifth-force experiments. Thus, correlating observations in EDM and fifth-force experiments could help distinguish axions from more generic light scalar scenarios.

Mantry, Sonny; Pitschmann, Mario; Ramsey-Musolf, Michael J.

2014-09-01

370

Application of the contour transformation method to a vertical electric dipole over Earth  

NASA Astrophysics Data System (ADS)

A contour transformation method is applied to the computation of the Sommerfeld integral associated with a vertical electric dipole above Earth. In this method the slowly varying part of the transformed Sommerfeld integrand is approximated by a few exponential terms using Prony's method. The resulting integrals are then carried out analytically, thereby, yielding incomplete Lipschitz-Hankel integrals. Therefore numerical integration of the Sommerfeld integral is unnecessary since the incomplete Lipschitz-Hankel integrals are computed using efficient Bessel series expansions. This method is compared with a direct numerical integration of the Sommerfeld integral and a contour deformation technique which also utilizes Prony's method. The results demonstrate that the contour transformation method enables the accurate and efficient computation of the Sommerfeld integral for all source and observation locations (i.e., near zone, far zone and even grazing). This technique can also be applied to problems involving multiple layers.

Dvorak, Steven L.; Mechaik, Mehdi M.

1993-05-01

371

Possible shape coexistence and magnetic dipole transitions in {sup 17}C and {sup 21}Ne  

SciTech Connect

Magnetic dipole (M1) transitions of N=11 nuclei {sup 17}C and {sup 21}Ne are investigated by using shell model and deformed Skyrme Hartree-Fock + blocked BCS wave functions. Shell model calculations predict well observed energy spectra and magnetic dipole transitions in {sup 21}Ne, while the results are rather poor to predict these observables in {sup 17}C. In the deformed HF calculations, the ground states of the two nuclei are shown to have large prolate deformations close to {beta}{sub 2}=0.4. It is also pointed out that the first K{sup {pi}}=1/2{sup +} state in {sup 21}Ne is prolately deformed, while the first K{sup {pi}}=1/2{sup +} state in {sup 17}C is predicted to have a large oblate deformation close to the ground state in energy, We point out that the experimentally observed large hindrance of the M1 transition between I{sup {pi}}=1/2{sup +} and 3/2{sup +} in {sup 17}C can be attributed to a shape coexistence near the ground state of {sup 17}C.

Sagawa, H. [Center for Mathematics and Physics, University of Aizu, Aizu-Wakamatsu, Fukushima 965-8580 (Japan); Zhou, X. R. [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005 (China); Suzuki, Toshio [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan); Yoshida, N. [Faculty of Informatics, Kansai University, Takatsuki 569-1095 (Japan)

2008-10-15

372

TOPICAL REVIEW: Electrical polarization and orbital magnetization: the modern theories  

NASA Astrophysics Data System (ADS)

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.

Resta, Raffaele

2010-03-01

373

Electrical polarization and orbital magnetization: the modern theories.  

PubMed

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

Resta, Raffaele

2010-03-31

374

Measurement and Calibration of the Corrector Magnets and the Chacane Dipole magnets for CTF3  

E-print Network

The magnetic field of the CTF3 corrector and Chicane magnets was measured with a 3D hall probe setup. The resulting field plot was used to calculate the bending angle of the magnets with respect to the magnet current. this information will be used as a calibration for their use in the CTF3.

Forstner, O

2003-01-01

375

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

E-print Network

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

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

2012-05-10

376

Test Results for HD1, a 16 Tesla Nb3Sn Dipole Magnet  

SciTech Connect

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 Nb{sub 3}Sn 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 of brittle conductor and high Lorentz stress, considerable care was taken to predict the magnet's mechanical responses to pre-stress, cool-down, and excitation. Subsequent cold testing satisfied expectations: Training started at 13.6 T, 83% of 'short-sample', achieved 90% in 10 quenches, and reached its peak bore field (16 T) after 19 quenches. The average plateau, {approx}92% of 'short-sample', appeared to be limited by 'stick-slip' conductor motions, consistent with the 16.2 T conductor 'lift-off' pre-stress that was chosen for this first test. Some lessons learned and some implications for future conductor and magnet technology development are presented and discussed.

Lietzke, A.F.; Bartlett, S.; Bish, P.; Caspi, S.; Chiesa, L.; Dietderich, D.; Ferracin, P.; Gourlay, S.A.; Goli, M.; Hafalia, R.R.; Higley, H.; Hannaford, R.; Lau, W.; Liggens, N.; Mattafirri, S.; McInturff, A.; Nyman, M.; Sabbi, G.; Scanlan, R.; Swanson, J.

2003-10-01

377

Recent Test Results of the High Field Nb3Sn Dipole Magnet HD2  

SciTech Connect

The 1 m long Nb{sub 3}Sn 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 room for a bore tube with a clear aperture of 36 mm. After a first series of tests where HD2 reached a maximum bore field of 13.8 T, corresponding to an estimated peak field on the conductor of 14.5 T, the magnet was disassembled and reloaded without the bore tube and with a clear aperture increased to 43 mm. We describe in this paper the magnet training observed in two consecutive tests after the removal of the bore tube, with a comparison of the quench performance with respect to the previous tests. An analysis of the voltage signals recorded before and after training quenches is then presented and discussed, and the results of coil visual inspections reported.

Ferracin, P.; Bingham, B.; Caspi, S.; Cheng, D. W.; Dietderich, D. R.; Felice, H.; Hafalia, A. R.; Hannaford, C. R.; Joseph, J.; Lietzke, A. F.; Lizarazo, J.; Sabbi, G.; Wang, X.

2009-10-19

378

Molecular Expressions: Electricity and Magnetism - Inductance  

NSDL National Science Digital Library

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

Davidson, Michael

2007-08-28

379

Electric dipole polarizabilities at imaginary frequencies for hydrogen, the alkali-metal, alkaline-earth, and noble gas atoms  

SciTech Connect

The electric dipole polarizabilities evaluated at imaginary frequencies for hydrogen, the alkali-metal atoms, the alkaline-earth atoms, and the noble gases are tabulated along with the resulting values of the atomic static polarizabilities, the atom-surface interaction constants, and the dispersion (or van der Waals) constants for the homonuclear and the heteronuclear diatomic combinations of the atoms.

Derevianko, Andrei [Physics Department, Univ. of Nevada, Reno, NV 89557-0058 (United States)], E-mail: andrei@unr.edu; Porsev, Sergey G. [Physics Department, Univ. of Nevada, Reno, NV 89557-0058 (United States); Petersburg Nuclear Physics Institute, Gatchina, Leningrad District 188300 (Russian Federation)], E-mail: sporsev@gmail.com; Babb, James F. [ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138-1516 (United States)], E-mail: jbabb@cfa.harvard.edu

2010-05-15

380

A NEW METHOD TO INVESTIGATE THE NEUTRON ELECTRIC DIPOLE MOMENT Euratom CCR-Ispra, Reactor Physics Dept.  

E-print Network

neutron beam and the polarization detection method are described and discussed in comparison with other241. A NEW METHOD TO INVESTIGATE THE NEUTRON ELECTRIC DIPOLE MOMENT M. FORTE, Euratom CCR électrique dipolaire du neutron (MED) est envisagée ; elle est basée sur l'interaction du MED du neutron et

Paris-Sud XI, Université de

381

Unusual electric response of the dislocations and the impurity dipoles in KNbO3 single crystals  

Microsoft Academic Search

A highly unusual electric response of the dislocations and the impurity dipoles in KNbO3 single crystals has been found. The etch pits representing these defects move in the structure carrying these defects with them. This shows that the defects have associated with them structural units that are orders of magnitude larger in physical size. Naturally these units are also associated

S. G. Ingle; R. N. Kakde

1995-01-01

382

Big black hole, little neutron star: Magnetic dipole fields in the Rindler spacetime  

NASA Astrophysics Data System (ADS)

As a black hole and neutron star approach during inspiral, the field lines of a magnetized neutron star eventually thread the black hole event horizon and a short-lived electromagnetic circuit is established. The black hole acts as a battery that provides power to the circuit, thereby lighting up the pair just before merger. Although originally suggested as an electromagnetic counterpart to gravitational-wave detection, a black hole battery is of more general interest as a novel luminous astrophysical source. To aid in the theoretical understanding, we present analytic solutions for the electromagnetic fields of a magnetic dipole in the presence of an event horizon. In the limit that the neutron star is very close to a Schwarzschild horizon, the Rindler limit, we can solve Maxwell’s equations exactly for a magnetic dipole on an arbitrary worldline. We present these solutions here and investigate a proxy for a small segment of the neutron star orbit around a big black hole. We find that the voltage the black hole battery can provide is in the range ˜1016 statvolts with a projected luminosity of 1042ergs/s for an M=10M? black hole, a neutron star with a B-field of 1012G, and an orbital velocity ˜0.5c at a distance of 3M from the horizon. Larger black holes provide less power for binary separations at a fixed number of gravitational radii. The black hole/neutron star system therefore has a significant power supply to light up various elements in the circuit possibly powering bursts, jets, beamed radiation, or even a hot spot on the neutron star crust.

D'Orazio, Daniel J.; Levin, Janna

2013-09-01

383

Electric control of magnetism at room temperature  

PubMed Central

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

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

2012-01-01

384

Electric control of magnetism at room temperature.  

PubMed

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

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

2012-01-01

385

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

SciTech Connect

Specialized hardware and software have been developed to facilitate harmonic error analysis measurements of one-meter-long Superconducting Super Collider (SSC) model dipole and quadrupole magnets. Cold bore measurements feature cryogenic search-coil arrays with high bucking ratios that also have sufficient sensitivity to make room-temperature measurements at the low magnet currents of approx.10 A. Three sets of search coils allow measurements of the center, either end, and/or the axially integrated field. Signals from the search coils are digitally integrated by means of a voltage-to-frequency converter feeding an up-down counter. The data are drift corrected, Fourier analyzed, converted to physical quantities, and printed and plotted. A cycle of measurements including data acquisition, processing, and the generation of tabular and graphic output requires 80 seconds. The vast amount of data generated (several hundred measurement cycles for each magnet) has led to the development of postprocessing programs and procedures. Spreadsheets allow easy manipulation and comparison of results within a test series and between magnets. 8 refs., 4 figs., 1 tab.

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

1987-09-01

386

Observability of an induced electric dipole moment of the neutron from nonlinear QED  

E-print Network

It has been shown recently that a neutron placed in an external quasistatic electric field develops an induced electric dipole moment $\\mathbf{p}_{\\mathrm{IND}}$ due to quantum fluctuations in the QED vacuum. A feasible experiment which could detect such an effect is proposed and described here. It is shown that the peculiar angular dependence of $\\mathbf{p}_{\\mathrm{IND}}$ on the orientation of the neutron spin leads to a characteristic asymmetry in polarized neutron scattering by heavy nuclei. This asymmetry can be of the order of $10^{-3}$ for neutrons with epithermal energies. For thermalized neutrons from a hot moderator one still expects experimentally accessible values of the order of $10^{-4}$. The contribution of the induced effect to the neutron scattering length is expected to be only one order of magnitude smaller than that due to the neutron polarizability from its quark substructure. The experimental observation of this scattering asymmetry would be the first ever signal of nonlinearity in electrodynamics due to quantum fluctuations in the QED vacuum.

O. Zimmer; C. A. Dominguez; H. Falomir; M. Loewe

2011-04-07

387

Observability of an induced electric dipole moment of the neutron from nonlinear QED  

E-print Network

It has been shown recently that a neutron placed in an external quasistatic electric field develops an induced electric dipole moment $\\mathbf{p}_{\\mathrm{IND}}$ due to quantum fluctuations in the QED vacuum. A feasible experiment which could detect such an effect is proposed and described here. It is shown that the peculiar angular dependence of $\\mathbf{p}_{\\mathrm{IND}}$ on the orientation of the neutron spin leads to a characteristic asymmetry in polarized neutron scattering by heavy nuclei. This asymmetry can be of the order of $10^{-3}$ for neutrons with epithermal energies. For thermalized neutrons from a hot moderator one still expects experimentally accessible values of the order of $10^{-4}$. The contribution of the induced effect to the neutron scattering length is expected to be only one order of magnitude smaller than that due to the neutron polarizability from its quark substructure. The experimental observation of this scattering asymmetry would be the first ever signal of nonlinearity in elect...

Zimmer, O; Falomir, H; Loewe, M

2011-01-01

388

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

NASA Astrophysics Data System (ADS)

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

Pretz, Jörg

2013-03-01

389

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

E-print Network

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

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

2008-10-29

390

Electrical properties of chain microstructure magnetic emulsions in magnetic field  

E-print Network

The work deals with the experimental study of the emulsion whose dispersion medium is a magnetic fluid while the disperse phase is formed by a glycerin-water mixture. It is demonstrated that under effect of a magnetic field chain aggregates form from the disperse phase drops. Such emulsion microstructure change affects its macroscopic properties. The emulsion dielectric permeability and specific electrical conductivity have been measured. It is demonstrated that under the effect of relatively weak external magnetic fields (~ 1 kA/m) the emulsion electrical parameters may change several fold. The work theoretically analyzes the discovered regularities of the emulsion electrical properties.

Arthur Zakinyan; Yuri Dikansky; Marita Bedzhanyan

2014-02-05

391

A fourth-order many-body perturbation theory calculation of the first and second electric dipole hyperpolarizability of ammonia  

NASA Astrophysics Data System (ADS)

The electric dipole moment (? ?), dipole polarizability (? ?,?) and second (? ????) dipole hyperpolarizability of ammonia were obtained from finite-field self-consistent-field (SCF) and complete fourth-order many-body perturbation theory (MP4) calculations. With z as the C3 axis, the following SDQ-MP4 results are reported: ? z = -0.6034 e a0, ? = 14.01 and ?? = 1.59 e2a20E-1h, ? = 30.47 and ?? = 8.87 e3a30E-2h, ? = 3864 e4a40E-3h. The triplets (T4) contribution to the fourth-order correction for the above properties is estimated to be 0.0083 e a0, 0.29 and 0.25 e2a20E-1h, 4.42 and 5.43 e3a30E-2h, 311 e4a40E-3h, respectively.

Maroulis, George

1992-07-01

392

Theory of dissociative recombination of a linear triatomic ion with permanent electric dipole moment: Study of HCO{sup +}  

SciTech Connect

We present a theoretical description of dissociative recombination of triatomic molecular ions having large permanent dipole moments. The study has been partly motivated by a discrepancy between experimental and theoretical cross sections for dissociative recombination of the HCO{sup +} ion. The HCO{sup +} ion has a considerable permanent dipole moment (Dapprox =4 D), which has not been taken explicitly into account in previous theoretical studies. In the present study, we include explicitly the effect of the permanent electric dipole on the dynamics of the incident electron using the generalized quantum defect theory, and we present the resulting cross section obtained. This demonstrates the possibility of applying generalized quantum defect theory to the dissociative recombination of molecular ions.

Douguet, Nicolas; Kokoouline, Viatcheslav; Greene, Chris H. [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States) and Laboratoire Aime Cotton, CNRS, Universite Paris-Sud XI, Orsay (France); Department of Physics and JILA, University of Colorado, Boulder, Colorado 80309 (United States)

2009-12-15

393

Nucleon Magnetic Moments and Electric Polarizabilities  

SciTech Connect

Electromagnetic properties of the nucleon are explored with lattice QCD using a novel technique. Focusing on background electric fields, we show how the electric polarizability can be extracted from nucleon correlation functions. A crucial step concerns addressing contributions from the magnetic moment, which affects the relativistic propagation of nucleons in electric fields. By properly handing these contributions, we can determine both magnetic moments and electric po larizabilities. Lattice results from anisotropic clover lattices are presented. Our method is not limited to the neutron; we show results for the proton as well.

W Detmold, B C Tiburzi, A Walker-Loud

2010-06-01

394

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

395

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

SciTech Connect

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

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

1982-01-01

396

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

SciTech Connect

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

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

1992-04-01

397

Measurement of a magnetic-dipole transition probability in Xe32+ using an electron-beam ion trap  

E-print Network

The transition probability for the 3d(4) D-5(2) <-- D-5(3) magnetic-dipole transition in Ti-like Xe (Xe32+) has been measured using an electron-beam ion trap. The unusually weak dependence of the transition energy on nuclear charge Z, and the fact...

Serpa, F. G.; Morgan, C. A.; Meyer, E. S.; Gillaspy, J. D.; Trabert, E.; Church, David A.; Takacs, E.

1997-01-01

398

Development of the EuCARD Nb3Sn Dipole Magnet FRESCA2  

E-print Network

The key objective of the Superconducting High Field Magnet work package of the European Project EuCARD, and specifically of the High Field Model task, is to design and fabricate the Nb3Sn dipole magnet FRESCA2. With an aperture of 100 mm and a target bore field of 13 T, the magnet is aimed at upgrading the FRESCA cable test facility at CERN. The design features four 1.5 m long double-layer coils wound with a 21 mm wide cable. The windings are contained in a support structure based on a 65 mm thick aluminum shell pre-tensioned with bladders. In order to qualify the assembly and loading procedure and to validate the finite element stress computations, the structure will be assembled around aluminum blocks, which replace the superconducting coils, and instrumented with strain gauges. In this paper, we report on the status of the assembly and we update on the progress on design and fabrication of tooling and coils.

Ferracin, P; Durante, M; Fazilleau, P; Fessia, P; Manil, P; Milanese, A; Munoz Garcia, J; Oberli, L; Perez, J; Rifflet, J; de Rijk, G; Rondeaux, F; Todesco, E

2013-01-01

399

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

NASA Astrophysics Data System (ADS)

The superconducting dipole prototype magnet of the collector ring for the Facility for Antiproton and Ion Research (FAIR) is an international cooperation project. The collaborative simulation and testing of the developed prototype magnet is presented in this paper. To evaluate the mechanical strength of the coil case during quench, a 3-dimensional (3D) electromagnetic (EM) model was developed based on the solid97 magnetic vector element in the ANSYS commercial software, which includes the air region, coil and yoke. EM analysis was carried out with a peak operating current at 278 A. Then, the solid97 element was transferred into the solid185 element, the coupled analysis was switched from electromagnetic to structural, and the finite element model for the coil case and glass-fiber reinforced composite (G10) spacers was established by the ANSYS Parametric Design Language based on the 3D model from the CATIA V5 software. However, to simulate the friction characteristics inside the coil case, the conta173 surface-to-surface contact element was established. The results for the coil case and G10 spacers show that they are safe and have sufficient strength, on the basis of testing in discharge and quench scenarios.

Zhu, Yinfeng; Zhu, Zhe; Xu, Houchang; Wu, Weiyue

2012-08-01

400

Can (electric-magnetic) duality be gauged?  

SciTech Connect

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

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

2011-02-15

401

Can (Electric-Magnetic) Duality Be Gauged?  

E-print Network

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

Claudio Bunster; Marc Henneaux

2010-11-25

402

Intensity of the earth's magnetic field - Evidence for a Mesozoic dipole low  

Microsoft Academic Search

All of the Triassic and younger paleointensity determinations made using the Thellier (1959) method have been compiled. The data set shows the occurrence of large, long-term changes of geomagnetic dipole strength with time. Although the average dipole strength has been approximately constant since the Late Cretaceous, a dipole strength only one third of the Cenozoic value prevailed during most of

Michel Prevot; Mohammed El-Messaoud Derder; Michael McWilliams; John Thompson

1990-01-01

403

Generation of electric and magnetic field during detonation of high explosive charges in boreholes  

NASA Astrophysics Data System (ADS)

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. Three components of electric field (vertical component in air and two horizontal components in the soil) and three components of the magnetic induction were recorded during the field experiments. Test conditions and physicomechanical properties of the soil exert significant influence on the parameters of electromagnetic signals generated by underground explosions 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 layered media. We used the solution for a field produced by stationary vertical and horizontal electric dipoles placed near the interface between two layers with different conductivity. The magnitude of the field source was estimated on the basis of the records of electromagnetic signals obtained at different distances from the borehole. For an underground explosion of a TNT charge with a mass of 2 kg carried out in granite the maximum estimated value of the electric dipole component is about 10-7 C m. This estimate is more than an order of magnitude greater than that obtained for an explosion of the same mass carried out in sandy loam.

Soloviev, S. P.; Sweeney, J. J.

2005-01-01

404

Buried antenna analysis at VHF. Part 1: The buried horizontal electric dipole  

NASA Astrophysics Data System (ADS)

A method was developed to find the far field radiation pattern of a buried horizontal electric dipole (HED) at 37.5 MHz. The imaginary part of the index of refraction was shown to be negligible for dry soil at this frequency so standard antenna theory and ray optic theory was used. The effect of the ground-air interface was modeled using the transmission coefficient and Snell's law for a dielectric interface. Because the current distribution for the buried HED depends on antenna construction, results are shown for the far field pattern in the air for different current distributions on the HED. The literature on this problem was reviewed; most used the Sommerfeld or moment methods to make the same calculations. The results of one of the reports using the Sommerfeld method could be compared and were found to be similar. An extensive bibliography is included. The analysis was then applied to a buried antenna array. The current distribution was known and was used to calculate the far field pattern. It was concluded that the far field pattern is highly dependent on the current distribution. This part is classified.

Burks, J. W.

1984-01-01

405

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

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

406

Determination of electric-dipole matrix elements in K and Rb from Stark shift measurements  

NASA Astrophysics Data System (ADS)

Stark shifts of potassium and rubidium D1 lines have been measured with high precision by Miller [Phys. Rev. A 49, 5128 (1994)]. In this work, we combine these measurements with our all-order calculations to determine the values of the electric-dipole matrix elements for the 4pj-3dj' transitions in K and the 5pj-4dj' transitions in Rb to high precision. The 4p1/2-3d3/2 and 5p1/2-4d3/2 transitions contribute on the order of 90% to the respective polarizabilities of the np1/2 states in K and Rb, and the remaining 10% can be accurately calculated using the relativistic all-order method. Therefore, the combination of the experimental data and theoretical calculations allows us to determine the np-(n-1)d matrix elements and their uncertainties. We compare these values with our all-order calculations of the np-(n-1)d matrix elements in K and Rb for a benchmark test of the accuracy of the all-order method for transitions involving nd states. Such matrix elements are of special interest for many applications, such as determination of “magic” wavelengths in alkali-metal atoms for state-insensitive cooling and trapping, and determination of blackbody radiation shifts in optical frequency standards with ions.

Arora, Bindiya; Safronova, M. S.; Clark, Charles W.

2007-11-01

407

Top quark electric dipole moment in a minimal supersymmetric standard model extension with vectorlike multiplets  

SciTech Connect

The electric dipole moment (EDM) of the top quark is calculated in a model with a vector like multiplet which mixes with the third generation in an extension of the minimal supersymmetric standard model. Such mixings allow for new CP violating phases. Including these new CP phases, the EDM of the top in this class of models is computed. The top EDM arises from loops involving the exchange of the W, the Z as well as from the exchange involving the charginos, the neutralinos, the gluino, and the vector like multiplet and their superpartners. The analysis of the EDM of the top is more complicated than for the light quarks because the mass of the external fermion, in this case the top quark mass cannot be ignored relative to the masses inside the loops. A numerical analysis is presented and it is shown that the top EDM could be close to 10{sup -19} ecm consistent with the current limits on the EDM of the electron, the neutron and on atomic EDMs. A top EDM of size 10{sup -19} ecm could be accessible in collider experiments such as the International Linear Collider.

Ibrahim, Tarek [Department of Physics, Faculty of Science, University of Alexandria, Alexandria (Egypt); Nath, Pran [Department of Physics, Northeastern University, Boston, Massachusetts 02115 (United States)

2010-09-01

408

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

SciTech Connect

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

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

2011-12-15

409

Extracting electric dipole breakup cross section of one-neutron halo nuclei from breakup observables  

E-print Network

How to extract an electric dipole (E1) breakup cross section \\sigma(E1) from one- neutron removal cross sections measured by using 12C and 208Pb targets, \\sigma_(-1n)^C and \\sigma_(-1n)^Pb, respectively, is discussed. It is shown that within about 5% error, \\sigma(E1) can be obtained by subtracting \\Gamma \\sigma_(-1n)^C from \\sigma_(- 1n)^Pb, as assumed in preceding studies. However, for the reaction of weakly-bound projectiles, the scaling factor \\Gamma is found to be two times as large as that usually adopted. As a result, we obtain 13-20% smaller \\sigma(E1) of 31Ne at 250 MeV/nucleon than extracted in a previous analysis of experimental data. By compiling the values of \\Gamma obtained for several projectiles, \\Gamma=(2.30 +/- 0.41)\\exp(- S_n)+(2.43 +/- 0.21) is obtained, where S_n is the neutron separation energy. The target mass number dependence of the nuclear parts of the one-neutron removal cross section and the elastic breakup cross section is also investigated.

Kazuki Yoshida; Tokuro Fukui; Kosho Minomo; Kazuyuki Ogata

2013-12-27

410

Atoms in Crossed Electric and Magnetic Fields  

NASA Astrophysics Data System (ADS)

In this dissertation, extensive experimental and theoretical work pertaining to three interesting aspects of the interaction of atoms with crossed electric and magnetic fields is presented. The first experiment discussed deals with the effects of weak crossed fields on sodium atoms. A fluorescence spectrum of laser excited sodium n = 11 states in an electric field of 2560 V/cm perpendicular to a magnetic field of 4.4 kG is presented, along with a comparison to theory. The data show the important effects of m-mixing and residual degeneracies which remain in the crossed fields. The next topic presented is the theoretical prediction of novel resonances, termed "quasi-Penning resonances," corresponding to electron states localized away from the nucleus at the Stark saddlepoint in strong crossed electric and magnetic fields. The stability and possibility for observation of these resonances is explored. Finally, extensive experimental maps of data are presented which compare laser induced ionization spectra of sodium atoms in crossed electric and magnetic fields to spectra in an electric field atone. The experiment explores the energy region of the electric field saddlepoint, where quasi-Penning resonances are predicted to occur. The magnetic field is too weak for the observation of these resonances, but the experiment provides important groundwork for the understanding of future experiments in strong crossed fields. The magnetic field is seen to cause splitting of some transitions due to the interaction of the electron spin with the magnetic field. Also, magnetic field induced state mixing causes a redistribution of oscillator strengths leading to changes in peak heights and auto-ionizing line widths. On the whole, however, the effect of the weak crossed magnetic field on the sodium Stark spectra remains small.

Korevaar, Eric John

1987-09-01

411

Improved study of electric dipoles on the Si(100)-2 × 1 surface by non-contact scanning nonlinear dielectric microscopy  

NASA Astrophysics Data System (ADS)

We studied a Si(100)-2 × 1 surface by non-contact scanning nonlinear dielectric microscopy (NC-SNDM). Simultaneously taken images of the topography and electric dipole moment distribution show that negative electric dipole moments are locally formed on individual dimers on the surface. In addition, we obtained the dc bias voltage dependence of the ?local(3) signal on a specific dimer by using an atom-tracking technique with NC-SNDM. We observed that the electric dipole induced a surface potential of around -250 mV on the dimer.

Suzuki, Masataka; Yamasue, Kohei; Abe, Masayuki; Sugimoto, Yoshiaki; Cho, Yasuo

2014-09-01

412

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

E-print Network

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

Burkhard Schmidt; Bretislav Friedrich

2013-12-20

413

Results from a Search for the Permanent Electric Dipole Moment (EDM) of ^199Hg  

NASA Astrophysics Data System (ADS)

Observation of a nonzero EDM would imply CP violation beyond the Standard Model. Additional sources of CP violation are expected to help explain the matter-antimatter asymmetry observed in our universe and naturally arise in extensions to the standard model such as supersymmetry. Our group has recently reported a new upper limit: |dHg| < 3.1x10-29 e-cm for the EDM of ^199Hg. The experiment compared the spin precession frequencies in four spin-polarized Hg vapor cells: two cells lie in parallel magnetic and anti-parallel electric fields, resulting in EDM-sensitive spin precession while the remaining two cells, at zero electric field, serve to cancel noise generated by magnetic field gradients and test for systematic errors. A frequency shift, linear in the applied electric field, due to the Stark mixing of atomic states has been identified and measured. A description of the EDM experiment and measurements that led to our recent result will be presented. )

Heckel, Blayne

2010-02-01

414

Progress Towards a New Measurement of the Permanent Electric Dipole Moment (EDM) of ^199Hg  

NASA Astrophysics Data System (ADS)

Observation of a nonzero EDM would imply CP violation beyond the Standard Model. The most precise EDM limit, established by our group several years ago for ^199Hg, is |dHg| < 2.1x10-28 e cm. To further refine these measurements, we recently switched from two to four spin- polarized Hg vapor cells: two lie in parallel magnetic and anti- parallel electric fields, resulting in EDM-sensitive spin precession; the remaining cells, at zero electric field, serve to cancel magnetic gradient noise and limit systematics due to charging and leakage currents. To date, the statistical uncertainty for the new EDM data is ± 1.7x10-29 e cm, a 3x improvement over our previous measurement. Constraining systematics at similar levels requires mitigating Stark interference, an EDM-mimicking vector light shift that is linear in the electric field. To this end, we have explored averaging data at two probe wavelengths where the Stark interference light shift is equal but opposite. Alternatively, this effect can be eliminated by determining the Larmor frequency ``in the dark'' between two probe pulses that establish the Larmor phase at the beginning and end of the dark period. We are currently implementing this latter scheme. We will discuss progress on an improved measurement of the ^199 Hg EDM.

Loftus, T. H.; Swallows, M. D.; Heckel, B. R.; Fortson, E. N.; Griffith, W. C.; Romalis, M. V.

2008-05-01

415

Multiconfiguration Dirac-Hartree-Fock calculations of the electric dipole moment of radium induced by the nuclear Schiff moment  

SciTech Connect

The multiconfiguration Dirac-Hartree-Fock theory has been employed to calculate the electric dipole moment of the 7s6d {sup 3}D{sub 2} state of radium induced by the nuclear Schiff moment. The results are dominated by valence and core-valence electron correlation effects. We show that the correlation effects can be evaluated in a converged series of multiconfiguration expansions.

Bieron, Jacek; Gaigalas, Gediminas; Gaidamauskas, Erikas; Fritzsche, Stephan; Indelicato, Paul; Joensson, Per [Instytut Fizyki imienia Mariana Smoluchowskiego, Uniwersytet Jagiellonski, Reymonta 4, 30-059 Krakow (Poland); Vilnius University Research Institute of Theoretical Physics and Astronomy, A. Gostauto 12, LT-01108 Vilnius, Lithuania and Vilnius Pedagogical University, Studentu 39, LT-08106 Vilnius (Lithuania); Helmholtzzentrum fuer Schwerionenforschung (GSI), D-64291 Darmstadt (Germany); Laboratoire Kastler Brossel, Ecole Normale Superieure CNRS, Universite P. et M. Curie-Paris 6, Case 74, 4 place Jussieu, 75252 Paris CEDEX 05 (France); Nature, Environment, Society, Malmoe University, S-20506 Malmoe (Sweden)

2009-07-15

416

Using the History of Electricity and Magnetism To Enhance Teaching.  

ERIC Educational Resources Information Center

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

Binnie, Anna

2001-01-01

417

Limits on the neutrino magnetic dipole moment from the luminosity function of hot white dwarfs  

NASA Astrophysics Data System (ADS)

Context. Recent determinations of the white dwarf luminosity function (WDLF) from very large surveys have extended our knowledge of the WDLF to very high luminosities. This, together with the availability of new full evolutionary white dwarf models that are reliable at high luminosities, have opened the possibility of testing particle emission in the core of very hot white dwarfs, where neutrino processes are dominant. Aims: We use the available WDLFs from the Sloan Digital Sky Survey and the SuperCOSMOS Sky Survey to constrain the value of the neutrino magnetic dipole moment (??). Methods: We used a state-of-the-art stellar evolution code to compute a grid of white dwarf cooling sequences under the assumptions of different values of ??. Then we constructed theoretical WDLFs for different values of ?? and performed a ?2-test to derive constraints on the value of ??. Results: We find that the WDLFs derived from the Sloan Digital Sky Survey and the SuperCOSMOS Sky Survey do not yield consistent results. The discrepancy between the two WDLFs suggests that the uncertainties are significantly underestimated. Consequently, we constructed a unified WDLF by averaging the SDSS and SSS and estimated the uncertainties by taking into account the differences between the WDLF at each magnitude bin. Then we compared all WDLFs with theoretical WDLFs. Comparison between theoretical WDLFs and both the SDSS and the averaged WDLF indicates that ?? should be ?? < 5 × 10-12 e?/(2mec). In particular, a ?2-test on the averaged WDLF suggests that observations of the disk WDLF exclude values of ?? > 5 × 10-12e?/(2mec) at more than a 95% confidence level, even when conservative estimates of the uncertainties are adopted. This is close to the best available constraints on ?? from the physics of globular clusters. Conclusions: Our study shows that modern WDLFs, which extend to the high-luminosity regime, are an excellent tool for constraining the emission of particles in the core of hot white dwarfs. However, discrepancies between different WDLFs suggest there might be some relevant unaccounted systematic errors. A larger set of completely independent WDLFs, as well as more detailed studies of the theoretical WDLFs and their own uncertainties, is desirable to explore the systematic uncertainties behind this constraint. Once this is done, we believe the Galactic disk WDLF will offer constraints on the magnetic dipole moment of the neutrino similar to the best available constraints obtainable from globular clusters.

Miller Bertolami, Marcelo Miguel

2014-02-01

418

Determination of electric-dipole matrix elements in K and Rb from Stark shift measurements  

SciTech Connect

Stark shifts of potassium and rubidium D1 lines have been measured with high precision by Miller et al. [Phys. Rev. A 49, 5128 (1994)]. In this work, we combine these measurements with our all-order calculations to determine the values of the electric-dipole matrix elements for the 4p{sub j}-3d{sub j{sup '}} transitions in K and the 5p{sub j}-4d{sub j{sup '}} transitions in Rb to high precision. The 4p{sub 1/2}-3d{sub 3/2} and 5p{sub 1/2}-4d{sub 3/2} transitions contribute on the order of 90% to the respective polarizabilities of the np{sub 1/2} states in K and Rb, and the remaining 10% can be accurately calculated using the relativistic all-order method. Therefore, the combination of the experimental data and theoretical calculations allows us to determine the np-(n-1)d matrix elements and their uncertainties. We compare these values with our all-order calculations of the np-(n-1)d matrix elements in K and Rb for a benchmark test of the accuracy of the all-order method for transitions involving nd states. Such matrix elements are of special interest for many applications, such as determination of ''magic'' wavelengths in alkali-metal atoms for state-insensitive cooling and trapping, and determination of blackbody radiation shifts in optical frequency standards with ions.

Arora, Bindiya; Safronova, M. S.; Clark, Charles W. [Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Physics Laboratory, National Institute of Standards and Technology, Technology Administration, U.S. Department of Commerce, Gaithersburg, Maryland 20899-8410 (United States)

2007-11-15

419

Mechanical Design of HD2, a 15 T Nb3Sn Dipole Magnet with a 35 mm Bore  

SciTech Connect

After the fabrication and test of HD1, a 16 T Nb{sub 3}Sn dipole magnet based on flat racetrack coil configuration, the Superconducting Magnet Program at Lawrence Berkeley National Laboratory (LBNL) is developing the Nb{sub 3}Sn 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 further step towards the application of block-type coils to high-field accelerator magnets. The design features tilted racetrack-type ends, to avoid obstructing the beam path, and a 4 mm thick stainless steel tube, to support the coil during the preloading operation. The mechanical structure, similar to the one used for HD1, is based on an external aluminum shell pretensioned with pressurized bladders. Axial rods and stainless steel plates provide longitudinal support to the coil ends during magnet excitation. A 3D finite element analysis has been performed to evaluate stresses and deformations from assembly to excitation, with particular emphasis on conductor displacements due to Lorentz forces. Numerical results are presented and discussed.

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

2006-06-01

420

IRON SATURATION CONTROL IN RHIC DIPOLE MAGNETS* P.A.Thompson,R.C.Gupta,S.A.Kahn,H.Hahn.G.H.Morgan,PJ.Wanderer,E.Willen.  

E-print Network

IRON SATURATION CONTROL IN RHIC DIPOLE MAGNETS* P.A.Thompson,R.C.Gupta,S.A.Kahn of the yoke iron. Changes have been made to the yoke to reduce these perturbations, in particular, decapole The proposed RHIC will include 360 "standard" superconducting dipoles(bore=BOmm, design field=3.45 T). The iron

Gupta, Ramesh

421

Electric-Magnetic Duality and Topological Insulators  

SciTech Connect

We work out the action of the SL(2,Z) electric-magnetic duality group for an insulator with a nontrivial permittivity, permeability, and theta angle. This theory has recently been proposed to be the correct low-energy effective action for topological insulators. As applications, we give manifestly SL(2,Z) covariant expressions for the Faraday rotation at orthogonal incidence at the interface of two such materials, as well as for the induced magnetic and electric charges, slightly clarifying the meaning of expressions previously derived in the literature. We also use electric-magnetic duality to find a gravitational dual for a strongly coupled version of this theory using the gauge/gravity correspondence.

Karch, A. [Department of Physics, University of Washington, Seattle, Washington 98195-1560 (United States)

2009-10-23

422

Electric and Magnetic Forces: Electrostatics and Current Electricity  

NSDL National Science Digital Library

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

National Science Teachers Association (NSTA)

1900-01-01

423

The photon detection operator and complementarity between an electric detector and a magnetic detector  

NASA Astrophysics Data System (ADS)

It has been a long-standing problem that there is no consistent definition of the photon position operator or photon number density in the context of quantum theory. In this paper, we derive the photon detection operator, which defines the location of photon absorption, by applying the theory of indirect measurement to quantum electrodynamics. It is shown that the photon detection probability depends on the properties of a photon-absorbing atom, in particular, on both electric and magnetic dipole moments of the atom. An experiment is proposed in which the complementarity of wave-particle nature of light will be tested. It is also discussed that the complementarity is related to the non-commutativity of the electric and the magnetic fields. (When this work was presented at the conference CEWQO2013, it had the title ‘Photon position operators and complementarity between electric detector and magnetic detector’.)

Tanimura, Shogo

2014-04-01

424

The design and development of a single piece, sandwhich tube coldmass support post for the SSC Collider Dipole Magnets  

SciTech Connect

This paper presents the design and development of the single piece, carbon/epoxy syntactic core sandwich tube support post concept for the 13-m and 15-m Collider Dipole Magnet (CDM). The engineering studies focus on balancing the structural and thermal requirements for the structure, and most importantly the implicit requirement of ``Designing for Producibility.`` Results from these studies, as well as the development program plan, will be presented.

Ahmad, A. [Superconducting Super Collider Lab., Dallas, TX (United States); Mehle, G. [General Dynamics Corp., San Diego, CA (United States). Space Systems Div.

1993-04-01

425

Measurement of net electric charge and dipole moment of dust aggregates in a complex plasma  

E-print Network

Understanding the agglomeration of dust particles in complex plasmas requires a knowledge of the basic properties such as the net electrostatic charge and dipole moment of the dust. In this study, dust aggregates are formed from gold coated mono-disperse spherical melamine-formaldehyde monomers in a radio-frequency (rf) argon discharge plasma. The behavior of observed dust aggregates is analyzed both by studying the particle trajectories and by employing computer models examining 3D structures of aggregates and their interactions and rotations as induced by torques arising from their dipole moments. These allow the basic characteristics of the dust aggregates, such as the electrostatic charge and dipole moment, to be determined. It is shown that the experimental results support the predicted values from computer models for aggregates in these environments.

Yousefi, Razieh; Carmona-Reyes, Jorge; Matthews, Lorin S; Hyde, Truell W

2014-01-01

426

Measurement of wall relaxation times of polarized Helium-3 in bulk liquid Helium-4 for the neutron electric dipole moment experiment  

NASA Astrophysics Data System (ADS)

The Neutron Electric Dipole Moment (nEDM) experiment that will take place at the Spallation Neutron Source (SNS) in Oak Ridge, Tennessee will measure the electric dipole moment (EDM) of the neutron with a precision of order 10-28 e-cm, utilizing spin-polarized 3He in bulk liquid 4He to detect neutron precession in a 10 mG magnetic field and 50 kV/cm electric field. Since depolarized 3He will produce a background, relaxation of the polarized 3He, characterized by the probability of depolarization per bounce, Pd, was measured for materials that will be in contact with polarized 3He. Depolarization probabilities were determined from measurements of the longitudinal relaxation time of polarized 3He in bulk liquid 4He inside an acrylic cell coated with the wavelength shifter deuterated tetraphenyl butadiene (d-TPB), which will be used to coat the nEDM measurement cell. Relaxation measurements were also performed while rods, made from plumbing material Torlon and valve bellows material BeCu, were present in the cell. The BeCu was coated with Pyralin resin prior to relaxation measurements, while relaxation measurements were performed both before and after the Torlon rod was coated with Pyralin resin. The depolarization probabilities were found to be Pd-TPBd <1.32x10-7 PBareTorlon d=1.01+/-0.08 x10-6 PCoatedTorlon d=2.5+/-0.1 x10-7 PCoatedBeCu d=7.9+/-0.3 x10-7 The relaxation rates extrapolated from the observed values of Pd for d-TPB, coated Torlon, and coated BeCu in the nEDM apparatus were found to be consistent with design goals.

Yoder, Jacob

427

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

NASA Astrophysics Data System (ADS)

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

Bali, G. S.; Bruckmann, F.; Endr?di, G.; Fodor, Z.; Katz, S. D.; Schäfer, A.

2014-04-01

428

Magnetic sponge phenomena associated with interchain dipole-dipole interactions in a series of ferrimagnetic chain compounds doped with minor diamagnetic species.  

PubMed

The donor/acceptor ionic chain (i.e., the D(+)A(-) chain) [Ru2(2-MeO-4-ClPhCO2)4(BTDA-TCNQ)]·2.5(benzene) (1; 2-MeO-4-ClPhCO2(-) = 2-methoxy-4-chlorobenzoate; BTDA-TCNQ = bis(1,2,5-thiadiazolo)tetracyanoquinodimethane) is a ferrimagnetic chain with S = 3/2 from [Ru2(II,III)](+) (i.e., D(+)) and S = 1/2 from BTDA-TCNQ(•-) (i.e., A(-)), with J ? -100 K, in which long-range antiferromagnetic ordering at TN = 11 K occurs because interchain antiferromagnetic interactions are critical. Compound 1 undergoes a reversible crystal-to-crystal structural transformation with the elimination/absorption of the crystallization solvent to form the dried compound [Ru2(2-MeO-4-ClPhCO2)4(BTDA-TCNQ)] (1'), which has a higher TN (14 K). This change is clearly caused by the shortening of the interchain distances because the exchange coupling parameter for the chain is the same in both 1 and 1'. The chain compounds in 1 can be doped with minor diamagnetic [Rh2(II,II)] species, [{(Ru2)(1-x)(Rh2)(x)(2-MeO-4-ClPhCO2)4}(BTDA-TCNQ)]·2.5(benzene) (x = 0.03 for Rh-3%; x = 0.05 for Rh-5%; x = 0.16 for Rh-16%), which shifts the TN to lower temperatures, the magnitude of the shift being dependent on the doping ratio x (TN = 5.9 K for Rh-3%, TN = 3.7 K for Rh-5%, and TN was not observed above 1.8 K for Rh-16%). Drying a doped compound increased its TN, as was found for 1': TN = 9.9 K for Rh-3%', TN = 9.2 K for Rh-5%', and TN was not observed above 1.8 K for Rh-16%'. TN had a linear relationship with the doping ratio x of the [Rh2] species in both the fresh and dried compounds. The TN linear relationship is associated with the magnitude of the effective magnetic dipole (i.e., the average correlation length) in the chains caused by the [Rh2] defects as well as naturally generated defects in the synthetic process and with the interchain distances affected by the crystal-to-crystal transformations. These results demonstrate that slightly modifying the short-range correlation lengths, which changes the magnetic dipole magnitudes, strongly affects the bulk antiferromagnetic transition, with key dipole-dipole interactions, in low-dimensional anisotropic systems. PMID:24750071

Nishio, Masaki; Miyasaka, Hitoshi

2014-05-01

429

Towards a Measurement of the Electric Dipole Moment of radon-223  

NASA Astrophysics Data System (ADS)

The observed baryon asymmetry in the universe requires a greater degree of CP violation than is contained in the CP-violating Standard Model processes discovered thus far. Since the permanent electric dipole moment (EDM) of a particle, atom, or molecule is a CP-odd observable, any nonzero measurement of an EDM above the small Standard Model background would indicate a new source of CP violation. The nuclear structure of 223Rn is expected to enhance its sensitivity to CP-violating interactions relative to 199Hg, currently the most sensitive atomic EDM result, motivating the development of the Radon EDM experiment. In anticipation of radon production at TRIUMF, we performed a series of studies to improve the design and predict the expected precision of the Radon EDM experiment. We designed and tested a prototype gas transfer apparatus that collects a sample of noble gas from a beam and transfers it to a measurement cell, achieving a transfer efficiency of about 40%. We recently improved this to greater than 90%. We studied the polarization and relaxation of radon using samples of 209Rn produced at SUNY Stony Brook's Nuclear Structure Laboratory and polarized it via spin-exchange with optically pumped rubidium. We constructed equations for the anisotropy of the gamma rays emitted by polarized 209Rn as a function of the rubidium polarization, the spin-exchange cross section sigmaSE, the wall-binding temperature T0, the quadrupole relaxation rate Ginfinity2 , and the cell temperature. Using rubidium polarization values measured by electron spin resonance, our radon polarization data indicated that a silane-based wall coating improved the relaxation rate in our cells. For T 0 = 350 K and sigmaSE = 2.5 x 10 -5A2, we found Ginfinity2 = 0.14 +/- 0.02 Hz in uncoated cells and Ginfinity2 = 0.042 +/- 0.012 Hz in coated cells. We used the coated-cell results to obtain a conservative estimate of the Radon EDM precision, 3 x 10-26e · cm at TRIUMF using gamma-ray anisotropies. Coupled with the enhancement effects, this indicates sensitivity to CP violation similar to that of 199Hg in the first phase of the Radon EDM experiment.

Tardiff, Eric R.

430

Molecular Expressions: Electricity and Magnetism - Transformer  

NSDL National Science Digital Library

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

Davidson, Michael

2007-10-23

431

Molecular Expressions: Electricity and Magnetism - Batteries  

NSDL National Science Digital Library

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

Davidson, Michael

2007-06-12

432

Finite nuclear mass corrections to electric and magnetic interactions in diatomic molecules  

SciTech Connect

In order to interpret precise measurements of molecular properties, finite nuclear mass corrections to the Born-Oppenheimer approximation have to be accounted for. It is demonstrated that they can be obtained systematically using nonadiabatic perturbation theory. The formulas for the leading corrections to the relativistic contribution to energy, the transition electric dipole moment, the electric polarizability, and the magnetic shielding constant are derived. They can be conveniently calculated for a fixed position of nuclei, as in the Born-Oppenheimer approximation, and then averaged over the rovibrational function.

Pachucki, Krzysztof [Institute of Theoretical Physics, University of Warsaw, PL-00-681 Warsaw, Hoza 69 (Poland)

2010-03-15

433

Magnetic response enhancement via electrically induced magnetic moments  

E-print Network

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

B. Jungnitsch; J. Evers

2008-04-22

434

Concept of Virtual Electric\\/Magnetic Walls and its Realization With Artificial Magnetic Conductor Technique  

Microsoft Academic Search

In this letter, we present a novel concept of virtual electric\\/magnetic walls which are formed by combining perfect electric conducting parallel plates and perfect magnetic conducting parallel plates. In practice, the perfect magnetic wall can be replaced with an artificial magnetic conductor surface. Two types of complementary transverse electromagnetic waveguides are built with the virtual electric\\/magnetic walls. The field distribution

Duochuan C. Li; Francois Boone; Maurizio Bozzi; Luca Perregrini; Ke Wu

2008-01-01

435

Superconducting Materials, Magnets and Electric Power Applications  

NASA Astrophysics Data System (ADS)

The surprising discovery of superconductivity a century ago launched a chain of convention-shattering innovations and discoveries in superconducting materials and applications that continues to this day. The range of large-scale applications grows with new materials discoveries - low temperature NbTi and Nb3Sn for liquid helium cooled superconducting magnets, intermediate temperature MgB2 for inexpensive cryocooled applications including MRI magnets, and high temperature YBCO and BSSCO for high current applications cooled with inexpensive liquid nitrogen. Applications based on YBCO address critical emerging challenges for the electricity grid, including high capacity superconducting cables to distribute power in urban areas; transmission of renewable electricity over long distances from source to load; high capacity DC interconnections among the three US grids; fast, self-healing fault current limiters to increase reliability; low-weight, high capacity generators enabling off-shore wind turbines; and superconducting magnetic energy storage for smoothing the variability of renewable sources. In addition to these grid applications, coated conductors based on YBCO deposited on strong Hastelloy substrates enable a new generation of all superconducting high field magnets capable of producing fields above 30 T, approximately 50% higher than the existing all superconducting limit based on Nb3Sn. The high fields, low power cost and the quiet electromagnetic and mechanical operation of such magnets could change the character of high field basic research on materials, enable a new generation of high-energy colliding beam experiments and extend the reach of high density superconducting magnetic energy storage.

Crabtree, George

2011-03-01

436

Assembly and Test of HD2, a 36 mm bore high field Nb3Sn Dipole Magnet  

SciTech Connect

We report on the fabrication, assembly, and test of the Nb{sub 3}Sn dipole magnet HD2. The magnet, aimed at demonstrating the application of Nb{sub 3}Sn superconductor in high field accelerator-type dipoles, features a 36 mm clear bore surrounded by block-type coils with tilted ends. The coil design is optimized to minimize geometric harmonics in the aperture and the magnetic peak field on the conductor in the coil ends. The target bore field of 15 T at 4.3 K is consistent with critical current measurements of extracted strands. The coils are horizontally pre-stressed during assembly using an external aluminum shell pre-tensioned with water-pressurized bladders. Axial pre-loading of the coil ends is accomplished through two end plates and four aluminum tension rods. The strain in coil, shell, and rods is monitored with strain gauges during assembly, cool-down and magnet excitation, and compared with 3D finite element computations.