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Sample records for magnetic domain-wall motion

  1. Thermal effects on transverse domain wall dynamics in magnetic nanowires

    SciTech Connect (OSTI)

    Leliaert, J.; Van de Wiele, B.; Vandermeulen, J.; Coene, A.; Dupré, L.; Vansteenkiste, A.; Waeyenberge, B. Van; Laurson, L.; Durin, G.

    2015-05-18

    Magnetic domain walls are proposed as data carriers in future spintronic devices, whose reliability depends on a complete understanding of the domain wall motion. Applications based on an accurate positioning of domain walls are inevitably influenced by thermal fluctuations. In this letter, we present a micromagnetic study of the thermal effects on this motion. As spin-polarized currents are the most used driving mechanism for domain walls, we have included this in our analysis. Our results show that at finite temperatures, the domain wall velocity has a drift and diffusion component, which are in excellent agreement with the theoretical values obtained from a generalized 1D model. The drift and diffusion component are independent of each other in perfect nanowires, and the mean square displacement scales linearly with time and temperature.

  2. Nonadiabatic Spin Torque Investigated Using Thermally Activated Magnetic Domain Wall Dynamics

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Nonadiabatic Spin Torque Investigated Using Thermally Activated Magnetic Domain Wall Dynamics M microscopy, we investigate the thermally activated motion of domain walls (DWs) between two positions properly analyzed, thermally activated processes at tem- peratures even well below the Curie temperature

  3. Stochastic Domain-Wall Depinning in Magnetic Nanowires

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of magnetic-domain walls and opens a path to further technological developments in spintronics applications. Magnetic Data Storage "Rats My disk drive has crashed. How will I...

  4. Temperature dependence of carrier spin polarization determined from current-induced domain wall motion in a Co/Ni nanowire

    SciTech Connect (OSTI)

    Ueda, K.; Koyama, T.; Hiramatsu, R.; Kobayashi, K.; Ono, T.; Chiba, D.; Fukami, S.; Tanigawa, H.; Suzuki, T.; Ohshima, N.; Ishiwata, N.; Nakatani, Y.

    2012-05-14

    We have investigated the temperature dependence of the current-induced magnetic domain wall (DW) motion in a perpendicularly magnetized Co/Ni nanowire at various temperatures and with various applied currents. The carrier spin polarization was estimated from the measured domain wall velocity. We found that it decreased more with increasing temperature from 100 K to 530 K than the saturation magnetization did.

  5. Current-driven domain wall motion enhanced by the microwave field

    SciTech Connect (OSTI)

    Wang, Xi-guang; Guo, Guang-hua Nie, Yao-zhuang; Wang, Dao-wei; Li, Zhi-xiong; Tang, Wei; Zeng, Zhong-ming

    2014-07-14

    The magnetic domain wall (DW) motion driven by a spin-polarized current opens a new concept for memory and logic devices. However, the critical current density required to overcome the intrinsic and/or extrinsic pinning of DW remains too large for practical applications. Here, we show, by using micromagnetic simulations and analytical approaches, that the application of a microwave field offers an effective solution to this problem. When a transverse microwave field is applied, the adiabatic spin-transfer torque (STT) alone can sustain a steady-state DW motion without the sign of Walker breakdown, meaning that the intrinsic pinning disappears. The extrinsic pinning can also be effectively reduced. Moreover, the DW velocity is increased greatly for the microwave-assisted DW motion. This provides a new way to manipulate the DW motion at low current densities.

  6. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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  7. Automotion of domain walls for spintronic interconnects

    SciTech Connect (OSTI)

    Nikonov, Dmitri E.; Manipatruni, Sasikanth; Young, Ian A.

    2014-06-07

    We simulate “automotion,” the transport of a magnetic domain wall under the influence of demagnetization and magnetic anisotropy, in nanoscale spintronic interconnects. In contrast to spin transfer driven magnetic domain wall motion, the proposed interconnects operate without longitudinal charge current transfer, with only a transient current pulse at domain wall creation and have favorable scaling down to the 20?nm dimension. Cases of both in-plane and out-of-plane magnetization are considered. Analytical dependence of the velocity of domain walls on the angle of magnetization are compared with full micromagnetic simulations. Deceleration, attenuation and disappearance, and reflection of domain walls are demonstrated through simulation. Dependences of the magnetization angle on the current pulse parameters are studied. The energy and delay analysis suggests that automotion is an attractive option for spintronic logic interconnects.

  8. Pinning induced by inter-domain wall interactions in planar magnetic nanowires

    SciTech Connect (OSTI)

    Hayward, T.J.; Bryan, M.T.; Fry, P.W.; Fundi, P.M.; Gibbs, M.R.J.; Allwood, D.A.; Im, M.-Y.; Fischer, P.

    2009-10-30

    We have investigated pinning potentials created by inter-domain wall magnetostatic interactions in planar magnetic nanowires. We show that these potentials can take the form of an energy barrier or an energy well depending on the walls' relative monopole moments, and that the applied magnetic fields required to overcome these potentials are significant. Both transverse and vortex wall pairs are investigated and it is found that transverse walls interact more strongly due to dipolar coupling between their magnetization structures. Simple analytical models which allow the effects of inter-domain wall interactions to be estimated are also presented.

  9. Magnetic domain wall propagation in a submicron spin-valve stripe: influence of the pinned layer

    E-Print Network [OSTI]

    Boyer, Edmond

    1/10 Magnetic domain wall propagation in a submicron spin-valve stripe: influence of the pinned ferromagnetic spin-valve stripe is investigated using giant magnetoresistance. A notch in the stripe efficiently generated in the vicinity of the notch by the pinned layer of the spin-valve. PACS: 72.25.Ba; 73.43.Qt; 75

  10. Phase diagram of magnetic domain walls in spin valve nano-stripes N. Rougemaille,1

    E-Print Network [OSTI]

    Boyer, Edmond

    Phase diagram of magnetic domain walls in spin valve nano-stripes N. Rougemaille,1 V. Uhlí,2, 1 O walls in Co/Cu/Py spin valve nano-stripes (Py: Permalloy), in which the Co layer is mostly single domain Magneto- Resistance. These stacking are called spin valve for a metal spacer layer, and pseudo spin valve

  11. Stochastic Domain-Wall Depinning in Magnetic Nanowires

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ferromagnetic wires of nanometer sizes are considered to be key components in future spintronic applications for novel classes of magnetic storage devices. One example is the...

  12. Magnetic behavior of 360° domain walls in patterned magnetic thin films

    E-Print Network [OSTI]

    Mascaro, Mark Daniel

    2012-01-01

    360° transverse domain walls (360DWs), which form readily from transverse 180° domain walls (180DWs) of opposite sense, demonstrate qualitatively distinct behaviors from their constituent 180DWs and are therefore of interest ...

  13. Magnetic domain wall manipulation in (Ga,Mn)As nanostructures for spintronic applications

    SciTech Connect (OSTI)

    Wosinski, Tadeusz; Andrearczyk, Tomasz; Figielski, Tadeusz; Olender, Karolina; Wrobel, Jerzy

    2014-02-21

    Ring-shaped nanostructures have been designed and fabricated by electron-beam lithography patterning and chemical etching from thin epitaxial layers of the ferromagnetic semiconductor (Ga,Mn)As. The nanostructures, in a form of planar rings with a slit, were supplied with four electrical terminals and subjected to magneto-transport studies under planar weak magnetic field. Magnetoresistive effects caused by manipulation of magnetic domain walls and magnetization reversal in the nanostructures have been investigated and possible applications of the nanostructures as four-terminal spintronic devices are discussed.

  14. Spin torque and heating effects in current-induced domain wall motion probed by transmission electron microscopy

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Spin torque and heating effects in current-induced domain wall motion probed by transmission are reported. Heating on membranes leads to thermally activated random behavior at low current densities and by backcoating the SiN membranes with Al, heating effects are significantly reduced. A set of indicators

  15. Steady-state domain wall motion driven by adiabatic spin-transfer torque with assistance of microwave field

    SciTech Connect (OSTI)

    Wang, Xi-guang; Guo, Guang-hua Nie, Yao-zhuang; Xia, Qing-lin; Tang, Wei; Wang, D.; Zeng, Zhong-ming

    2013-12-23

    We have studied the current-induced displacement of a 180° Bloch wall by means of micromagnetic simulation and analytical approach. It is found that the adiabatic spin-transfer torque can sustain a steady-state domain wall (DW) motion in the direction opposite to that of the electron flow without Walker Breakdown when a transverse microwave field is applied. This kind of motion is very sensitive to the microwave frequency and can be resonantly enhanced by exciting the domain wall thickness oscillation mode. A one-dimensional analytical model was established to account for the microwave-assisted wall motion. These findings may be helpful for reducing the critical spin-polarized current density and designing DW-based spintronic devices.

  16. Contributions of domain wall motion to complex electromechanical coefficients of 0.62Pb,,Mg1/3Nb2/3...O30.38PbTiO3 crystals

    E-Print Network [OSTI]

    Cao, Wenwu

    Contributions of domain wall motion to complex electromechanical coefficients of 0.62Pb,,Mg1/3Nb2 electromechanical coefficients and loss factors change dramatically at the coercive field Ec around 250 V, the imaginary parts of the electromechanical coefficients can be used to study the degree of domain wall motions

  17. Droplet Nucleation and Domain Wall Motion in a Bounded Interval Robert S. Maier

    E-Print Network [OSTI]

    Maier, Robert S.

    magnetization. In the weak-noise limit, noise-activated magnetization reversals become exponentially rare, the reversal rate being given by the Kramers formula "!$#&% ')(1032547698 . Here 6 is the noise strength, 0 study a spatially extended model of noise-induced magne- tization reversal: a classical Ginzburg

  18. Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic

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  19. Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  20. Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  1. DOMAIN WALL MOTION IN R. WIESER # , U. NOWAK and K. D. USADEL

    E-Print Network [OSTI]

    Usadel, K. D.

    nanowires are possible candidates for patterned magnetic storage media (Ross et al. (2000); Nielsch et al. (2002)). For these nanowires and also for other future magneto­electronic devices the understanding.: +49 203 379 2969, fax: +49 203 379 3665, email: robert@thp.uni­duisburg.de 1 #12; of the nanostructure

  2. High efficiency of the spin-orbit torques induced domain wall motion in asymmetric interfacial multilayered Tb/Co wires

    SciTech Connect (OSTI)

    Bang, Do; Awano, Hiroyuki

    2015-05-07

    We investigated current-induced DW motion in asymmetric interfacial multilayered Tb/Co wires for various thicknesses of magnetic and Pt-capping layers. It is found that the driving mechanism for the DW motion changes from interfacial to bulk effects at much thick magnetic layer (up to 19.8?nm). In thin wires, linearly depinning field dependence of critical current density and in-plane field dependence of DW velocity suggest that the extrinsic pinning governs field-induced DW motion and injecting current can be regarded as an effective field. It is expected that the high efficiency of spin-orbit torques in thick magnetic multilayers would have important implication for future spintronic devices based on in-plane current induced-DW motion or switching.

  3. Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on the Dynamic Behavior of Magnetic Vortices Print Soft magnetic, micron-sized thin-film structures with magnetic vortices are intriguing systems that may one day be used in...

  4. Domain wall assisted magnetization switching in (111) oriented L1{sub 0} FePt grown on a soft magnetic metallic glass

    SciTech Connect (OSTI)

    Kaushik, Neelam; Sharma, Parmanand; Yubuta, Kunio; Makino, Akihiro; Inoue, Akihisa

    2010-08-16

    We report on growth and magnetic properties of exchange-coupled (111)-L1{sub 0} FePt hard/CoFeTaB soft magnetic metallic glass bilayered structure processed at lower temperature ({approx}400 deg. C). Single phaselike hysteresis loops with tailorable coercivity (<8.2 kOe) in out of plane direction are obtained. The magnetization switching mechanism is identified as domain wall assisted. In views of excellent nanofabrication abilities of metallic glass thin film and the ability to grow preferred oriented L1{sub 0} FePt, the present bilayered structure is very promising for the fabrication of high density bit--patterned magnetic recording media and other spintronic devices.

  5. Influence of topography and Co domain walls on the magnetization reversal of the FeNi layer in FeNi/Al2O3/Co magnetic tunnel junctions

    E-Print Network [OSTI]

    Kuch, Wolfgang

    Influence of topography and Co domain walls on the magnetization reversal of the FeNi layer in Fe situated on and situated be- tween steps is large. To test the influence of the topography microscopic view of the influence of the substrate-induced layer topography on the magnetization reversal

  6. Gravitational Effects in Supersymmetric Domain Wall Backgrounds

    E-Print Network [OSTI]

    M. Cvetic; S. Griffies

    1992-04-13

    A recent study of supersymmetric domain walls in $N=1$ supergravity theories revealed a new class of domain walls interpolating between supersymmetric vacua with different non-positive cosmological constants. We classify three classes of domain wall configurations and study the geodesic structure of the induced space-time. Motion of massive test particles in such space-times shows that these walls are always repulsive from the anti-deSitter (AdS) side, while on the Minkowski side test particles feel no force. Freely falling particles far away from a wall in an AdS vacuum experience a constant proper acceleration, \\ie\\ they are Rindler particles. A new coordinate system for discussing AdS space-time is presented which eliminates the use of a periodic time-like coordinate.

  7. Domain walls in gapped graphene

    E-Print Network [OSTI]

    Semenoff, G W; Zhou, Fei

    2015-01-01

    The electronic properties of a particular class of domain walls in gapped graphene are investigated. We show that they can support mid-gap states which are localized in the vicinity of the domain wall and propagate along its length. With a finite density of domain walls, these states can alter the electronic properties of gapped graphene significantly. If the mid-gap band is partially filled,the domain wall can behave like a one-dimensional metal embedded in a semi-conductor, and could potentially be used as a single-channel quantum wire.

  8. Domain walls in gapped graphene

    E-Print Network [OSTI]

    G. W. Semenoff; V. Semenoff; Fei Zhou

    2008-05-31

    The electronic properties of a particular class of domain walls in gapped graphene are investigated. We show that they can support mid-gap states which are localized in the vicinity of the domain wall and propagate along its length. With a finite density of domain walls, these states can alter the electronic properties of gapped graphene significantly. If the mid-gap band is partially filled,the domain wall can behave like a one-dimensional metal embedded in a semi-conductor, and could potentially be used as a single-channel quantum wire.

  9. Domain wall mobility in nanowires: transverse versus vortex walls R. Wieser, U. Nowak and K. D. Usadel

    E-Print Network [OSTI]

    Usadel, K. D.

    Arrays of magnetic nanowires are possible candidates for patterned magnetic storage media [1, 2]. For these nanowires and also for other future magneto­electronic devices the understanding of domain wall motion and mobility is important for the controlled switching of the nanostructure. In a recent experiment

  10. Domain wall displacement by remote spin-current injection

    E-Print Network [OSTI]

    Skirdkov, P. N.

    We demonstrate numerically the ability to displace a magnetic domain wall (DW) by remote spin current injection. We consider a long and narrow magnetic nanostripe with a single DW. The spin-polarized current is injected ...

  11. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

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  12. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

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  13. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

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  14. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

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  15. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

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  16. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

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  17. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

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  18. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

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  19. Depinning transition of a domain wall in ferromagnetic films

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xi, Bin; Luo, Meng -Bo; Vinokur, Valerii M.; Hu, Xiao

    2015-09-14

    We report first principle numerical study of domain wall (DW) depinning in two-dimensional magnetic film, which is modeled by 2D random-field Ising system with the dipole-dipole interaction. We observe non-conventional activation-type motion of DW and reveal the fractal structure of DW near the depinning transition. We determine scaling functions describing critical dynamics near the transition and obtain universal exponents establishing connection between thermal softening of pinning potential and critical dynamics. In addition, we observe that tuning the strength of the dipole-dipole interaction switches DW dynamics between two different universality classes, corresponding to two distinct dynamic regimes characterized by non-Arrhenius andmore »conventional Arrhenius-type DW motions.« less

  20. Propagating and reflecting of spin wave in permalloy nanostrip with 360° domain wall

    SciTech Connect (OSTI)

    Zhang, Senfu; Mu, Congpu; Zhu, Qiyuan; Zheng, Qi; Liu, Xianyin; Wang, Jianbo; Liu, Qingfang

    2014-01-07

    By micromagnetic simulation, we investigated the interaction between propagating spin wave (or magnonic) and a 360° domain wall in a nanostrip. It is found that propagating spin wave can drive a 360° domain wall motion, and the velocity and direction are closely related to the transmission coefficient of the spin wave of the domain wall. When the spin wave passes through the domain wall completely, the 360° domain wall moves toward the spin wave source. When the spin wave is reflected by the domain wall, the 360° domain wall moves along the spin wave propagation direction. Moreover, when the frequency of the spin wave is coincident with that of the 360° domain wall normal mode, the 360° domain wall velocity will be resonantly enhanced no matter which direction the 360 DW moves along. On the other hand, when the spin wave is reflected from the moving 360° domain wall, we observed the Doppler effect clearly. After passing through a 360° domain wall, the phase of the spin wave is changed, and the phase shift is related to the frequency. Nevertheless, phase shift could be manipulated by the number of 360° domain walls that spin wave passing through.

  1. Effective Supergravity for Supergravity Domain Walls

    E-Print Network [OSTI]

    M. Cvetic; N. D. Lambert

    2002-05-23

    We discuss the low energy effective action for the Bosonic and Fermionic zero-modes of a smooth BPS Randall-Sundrum domain wall, including the induced supergravity on the wall. The result is a pure supergravity in one lower dimension. In particular, and in contrast to non-gravitational domain walls or domain walls in a compact space, the zero-modes representing transverse fluctuations of domain wall have vanishing action.

  2. Spatially resolved observation of domain-wall propagation in a submicron ferromagnetic NOT-gate

    E-Print Network [OSTI]

    Grütter, Peter

    , one head-to-head or tail-to-tail domain wall propagates in the structure. Magnetic fields above by the polarity of the adjacent wire magnetization directions as either head-to- head or tail-to-tail domain walls-wall propagation. MFM using low magnetic moment tips 30 nm CoPtCr was operated in the constant height mode

  3. Droplet Nucleation and Domain Wall Motion in a Bounded Interval Robert S. Maier 1;2 and D. L. Stein 2;1

    E-Print Network [OSTI]

    Maier, Robert S.

    and negative magnetization. In the weak­noise limit, noise­activated magnetization reversals become exponentially rare, the reversal rate being given by the Kramers formula \\Gamma ¸ \\Gamma 0 exp], who worked out a `large deviation theory' of its magnetization reversals, but did not compute

  4. Charm physics with Moebius Domain Wall Fermions

    E-Print Network [OSTI]

    Andreas Jüttner; Francesco Sanfilippo; Justus Tobias Tsang; Peter Boyle; Marina Marinkovic; Shoji Hashimoto; Takashi Kaneko; Yong-Gwi Cho

    2015-01-04

    We present results showing that Domain Wall fermions are a suitable discretisation for the simulation of heavy quarks. This is done by a continuum scaling study of charm quarks in a M\\"obius Domain Wall formalism using a quenched set-up. We find that discretisation effects remain well controlled by the choice of Domain Wall parameters preparing the ground work for the ongoing dynamical $2+1f$ charm program of RBC/UKQCD.

  5. Charm physics with Moebius Domain Wall Fermions

    E-Print Network [OSTI]

    Jüttner, Andreas; Tsang, Justus Tobias; Boyle, Peter; Marinkovic, Marina; Hashimoto, Shoji; Kaneko, Takashi; Cho, Yong-Gwi

    2015-01-01

    We present results showing that Domain Wall fermions are a suitable discretisation for the simulation of heavy quarks. This is done by a continuum scaling study of charm quarks in a M\\"obius Domain Wall formalism using a quenched set-up. We find that discretisation effects remain well controlled by the choice of Domain Wall parameters preparing the ground work for the ongoing dynamical $2+1f$ charm program of RBC/UKQCD.

  6. Nonlinear magnetoinductive waves and domain walls in composite metamaterials

    E-Print Network [OSTI]

    Nonlinear magnetoinductive waves and domain walls in composite metamaterials Ilya V. Shadrivov a-handed composite metamaterials. We derive the coupled equations for describing the propagation of magnetoinductive waves, and show that in the nonlinear regime the magnetic response of a metamaterial may become bistable

  7. Magnetic domain structure and domain-wall energy in UFe{sub 8}Ni{sub 2}Si{sub 2} and UFe{sub 6}Ni{sub 4}Si{sub 2} intermetallic compounds

    SciTech Connect (OSTI)

    Wyslocki, J.J.; Suski, W.; Wochowski, K.

    1994-03-01

    Magnetic domain structures in the UFe{sub 8}Ni{sub 2}Si{sub 2} and UFe{sub 6}Ni{sub 4}Si{sub 2} compounds were studied using the powder pattern method. The domain structure observed is typical for uniaxial materials. The domain-wall energy density {gamma} was determined from the average surface domain width D{sub s} observed on surfaces perpendicular to the easy axis as equal to 16 erg/cm{sup 2} for UFe{sub 8}Ni{sub 2}Si{sub 2} and 10 erg/cm{sup 2} for UFe{sub 6}Ni{sub 4}Si{sub 2}. Moreover, the critical diameter for single domain particle D{sub c} was calculated for the studied compounds.

  8. One-dimensional domain walls in thin ferromagnetic films with fourfold anisotropy

    E-Print Network [OSTI]

    Ross G. Lund; Cyrill B. Muratov

    2015-09-23

    We study the properties of domain walls and domain patterns in ultrathin epitaxial magnetic films with two orthogonal in-plane easy axes, which we call fourfold materials. In these materials, the magnetization vector is constrained to lie entirely in the film plane and has four preferred directions dictated by the easy axes. We prove the existence of $90^\\circ$ and $180^\\circ$ domain walls in these materials as minimizers of a nonlocal one-dimensional energy functional. Further, we investigate numerically the role of the considered domain wall solutions for pattern formation in a rectangular sample.

  9. Scattering from a Domain Wall in a Spontaneously Broken Gauge Theory

    E-Print Network [OSTI]

    Glennys R. Farrar; John W. McIntosh, Jr

    1994-12-20

    We study the interaction of particles with a domain wall at a symmetry-breaking phase transition by perturbing about the domain wall solution. We find the particulate excitations appropriate near the domain wall and relate them to the particles present far from the wall in the uniform broken and unbroken phases. For a quartic Higgs potential we find analytic solutions to the equations of motion and derive reflection and transmission coefficients. We discover several bound states for particles near the wall. Finally, we apply our results to the electroweak phase transition in the standard model.

  10. End states, ladder compounds, and domain wall fermions

    E-Print Network [OSTI]

    Michael Creutz

    1999-09-01

    A magnetic field applied to a cross linked ladder compound can generate isolated electronic states bound to the ends of the chain. After exploring the interference phenomena responsible, I discuss a connection to the domain wall approach to chiral fermions in lattice gauge theory. The robust nature of the states under small variations of the bond strengths is tied to chiral symmetry and the multiplicative renormalization of fermion masses.

  11. Thermodynamics of free Domain Wall fermions

    E-Print Network [OSTI]

    R. V. Gavai; Sayantan Sharma

    2008-11-19

    Studying various thermodynamic quantities for the free domain wall fermions for both finite and infinite fifth dimensional extent N_5, we find that the lattice corrections are minimum for $N_T\\geq10$ for both energy density and susceptibility, for its irrelevant parameter M in the range 1.45-1.50. The correction terms are, however, quite large for small lattice sizes of $N_T\\leq8$. We propose modifications of the domain wall operator, as well as the overlap operator, to reduce the finite cut-off effects to within 10% of the continuum results of the thermodynamic quantities for the currently used N_T=6-8 lattices. Incorporating chemical potential, we show that \\mu^2 divergences are absent for a large class of such domain wall fermion actions although the chiral symmetry is broken for $\\mu\

  12. Perforation of domain wall by point mass

    E-Print Network [OSTI]

    D. V. Gal'tsov; E. Yu. Melkumova; P. A. Spirin

    2013-12-30

    We investigate collision of a point particle and an infinitely thin planar domain wall interacting gravitationally within the linearized gravity in Minkowski space-time of arbitrary dimension. In this setting we are able to describe analytically the perforation of the wall by an impinging particle, showing that it is accompanied by excitation of the spherical shock branon wave propagating outwards with the speed of light. Formally, the shock wave is a free solution of the branon wave equation which has to be added to ensure the validity of the retarded solution at the perforation point. Physically, the domain wall gets excited due to the shake caused by an instantaneous change of sign of the repulsive gravitational force. This effect is shown to hold, in particular, in four space-time dimensions, being applicable to the problem of cosmological domain walls.

  13. Perforation of domain wall by point mass

    E-Print Network [OSTI]

    Gal'tsov, D V; Spirin, P A

    2013-01-01

    We investigate collision of a point particle and an infinitely thin planar domain wall interacting gravitationally within the linearized gravity in Minkowski space-time of arbitrary dimension. In this setting we are able to describe analytically the perforation of the wall by an impinging particle, showing that it is accompanied by excitation of the spherical shock branon wave propagating outwards with the speed of light. Formally, the shock wave is a free solution of the branon wave equation which has to be added to ensure the validity of the retarded solution at the perforation point. Physically, the domain wall gets excited due to the shake caused by an instantaneous change of sign of the repulsive gravitational force. This effect is shown to hold, in particular, in four space-time dimensions, being applicable to the problem of cosmological domain walls.

  14. Standing gravitational waves from domain walls

    E-Print Network [OSTI]

    Merab Gogberashvili; Shynaray Myrzakul; Douglas Singleton

    2009-07-19

    We construct a plane symmetric, standing gravitational wave for a domain wall plus a massless scalar field. The scalar field can be associated with a fluid which has the properties of `stiff' matter, i.e. matter in which the speed of sound equals the speed of light. Although domain walls are observationally ruled out in the present era the solution has interesting features which might shed light on the character of exact non-linear wave solutions to Einstein's equations. Additionally this solution may act as a template for higher dimensional 'brane-world' model standing waves.

  15. Solitons and Domain Walls in Odd Dimensions

    E-Print Network [OSTI]

    N. D. Lambert; G. W. Gibbons

    2000-07-04

    We discuss the existance of smooth soliton solutions which interpolate between supersymmetric vacua in odd-dimensional theories. In particular we apply this analysis to a wide class of supergravities to argue against the existence of smooth domain walls interpolating between supersymmetric vacua. We find that if the superpotential changes sign then any Goldstino modes will diverge.

  16. Domain Wall Pinning and Dislocations: Investigating Magnetite Deformed Under Conditions Analogous to Nature Using Transmission Electron Microscopy

    E-Print Network [OSTI]

    Lindquist, A. K.; Feinberg, J. M.; Harrison, R. J.; Loudon, J. C.; Newell, A. J.

    2015-03-19

    In this study, we deformed samples cut from a single magnetite octahedron and used transmission electron microscopy (TEM) and magnetic measurements to experimentally verify earlier computational models of magnetic domain wall pinning by dislocations...

  17. Domain wall conduction in multiaxial ferroelectrics

    SciTech Connect (OSTI)

    Eliseev, E. A.; Morozovska, A. N.; Svechnikov, S. V.; Maksymovych, Petro; Kalinin, Sergei V

    2012-01-01

    The conductance of domain wall structures consisting of either stripes or cylindrical domains in multiaxial ferroelectric-semiconductors is analyzed. The effects of the flexoelectric coupling, domain size, wall tilt, and curvature on charge accumulation are analyzed using the Landau-Ginsburg Devonshire theory for polarization vector combined with the Poisson equation for charge distributions. The proximity and size effect of the electron and donor accumulation/depletion by thin stripe domains and cylindrical nanodomains are revealed. In contrast to thick domain stripes and wider cylindrical domains, in which the carrier accumulation (and so the static conductivity) sharply increases at the domain walls only, small nanodomains of radii less than 5-10 correlation lengths appeared conducting across the entire cross-section. Implications of such conductive nanosized channels may be promising for nanoelectronics.

  18. Inflationary power asymmetry from primordial domain walls

    E-Print Network [OSTI]

    Jazayeri, Sadra; Firouzjahi, Hassan; Solomon, Adam R; Wang, Yi

    2014-01-01

    We study the asymmetric primordial fluctuations in a model of inflation in which translational invariance is broken by a domain wall. We calculate the corrections to the power spectrum of curvature perturbations; they are anisotropic and contain dipole, quadrupole, and higher multipoles with non-trivial scale-dependent amplitudes. Inspired by observations of these multipole asymmetries in terms of two-point correlations and variance in real space, we demonstrate that this model can explain the observed anomalous power asymmetry of the cosmic microwave background (CMB) sky, including its characteristic feature that the dipole dominates over higher multipoles. We test the viability of the model and place approximate constraints on its parameters by using observational values of dipole, quadrupole, and octopole amplitudes of the asymmetry measured by a local-variance estimator. We find that a configuration of the model in which the CMB sphere does not intersect the domain wall during inflation provides a good fi...

  19. Quantum Fusion of Domain Walls with Fluxes

    E-Print Network [OSTI]

    S. Bolognesi; M. Shifman; M. B. Voloshin

    2009-07-20

    We study how fluxes on the domain wall world volume modify quantum fusion of two distant parallel domain walls into a composite wall. The elementary wall fluxes can be separated into parallel and antiparallel components. The parallel component affects neither the binding energy nor the process of quantum merger. The antiparallel fluxes, instead, increase the binding energy and, against naive expectations, suppress quantum fusion. In the small flux limit we explicitly find the bounce solution and the fusion rate as a function of the flux. We argue that at large (antiparallel) fluxes there exists a critical value of the flux (versus the difference in the wall tensions), which switches off quantum fusion altogether. This phenomenon of flux-related wall stabilization is rather peculiar: it is unrelated to any conserved quantity. Our consideration of the flux-related all stabilization is based on substantiated arguments that fall short of complete proof.

  20. Light quark masses using domain wall fermions

    E-Print Network [OSTI]

    Tom Blum; Amarjit Soni; Matthew Wingate

    1998-09-10

    We compute the one-loop self-energy correction to the massive domain wall quark propagator. Combining this calculation with simulations at several gauge couplings, we estimate the strange quark mass in the continuum limit. The perturbative one-loop mass renormalization is comparable to that for Wilson quarks and considerably smaller than that for Kogut-Susskind quarks. Also, scaling violations appear mild in comparison to other errors at present. Given their good chiral behavior and these features, domain wall quarks are attractive for evaluating the light quark masses. Our preliminary quenched result is m_s(2 GeV) = 82(15) MeV in the ${\\bar{MS}}$ scheme.

  1. In-situ observation of domain wall motion in Pb(In{sub 1/2}Nb{sub 1/2})O{sub 3}-Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} crystals

    SciTech Connect (OSTI)

    Lin, Dabin; Cai, Changlong [Laboratory of Thin Film Techniques and Optical Test, Xi'an Technological University, Xi'an 710032 (China); Li, Zhenrong, E-mail: zhrli@mail.xjtu.edu.cn; Li, Fei; Xu, Zhuo [Electronic Materials Research Laboratory, Key Laboratory of Education Ministry and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049 (China); Zhang, Shujun, E-mail: soz1@psu.edu [Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Cheng, Yaojin [Science and Technology on Low-Light-Level Night Vision Laboratory, Xi'an 710065 (China)

    2014-07-21

    Various domain structures, including wave-like domains, mixed needle-like and laminar domains, typical embedded 90° and 180° domains, have been observed in unpoled rhombohedral, monoclinic, and tetragonal Pb(In{sub 1/2}Nb{sub 1/2})O{sub 3}-Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} (PIN-PMN-PT) crystals by polarizing light microscope; while in poled tetragonal crystals, the parallel 180° domains were reversed and only vertical 90° domain walls were observed. For 0.24PIN-0.42PMN-0.34PT crystals with morphotropic phase boundary composition, the domain wall motion was in-situ observed as a function of applied electric field along crystallographic [100] direction. With increasing the electric field from 0 to 12?kV/cm, the rhombohedral (R) domains were found to change to monoclinic (M) domains and then to tetragonal (T) domains. The electric field-induced phase transition was also confirmed by X-ray diffraction and the temperature-dependent dielectric behavior.

  2. Melting Instantons, Domain Walls, and Large N

    E-Print Network [OSTI]

    H. B. Thacker

    2008-10-22

    Monte Carlo studies of $CP^{N-1}$ sigma models have shown that the structure of topological charge in these models undergoes a sharp transition at $N=N_c\\approx 4$. For $NN_c$ it is dominated by extended, thin, 1-dimensionally coherent membranes of topological charge, which can be interpreted as domain walls between discrete quasi-stable vacua. These vacua differ by a unit of background electric flux. The transition can be identified as the delocalization of topological charge, or "instanton melting," a phenomenon first suggested by Witten to resolve the conflict between instantons and large $N$ behavior. Implications for $QCD$ are discussed.

  3. Control of domain wall pinning by localised focused Ga?{sup +} ion irradiation on Au capped NiFe nanowires

    SciTech Connect (OSTI)

    Burn, D. M. Atkinson, D.

    2014-10-28

    Understanding domain wall pinning and propagation in nanowires are important for future spintronics and nanoparticle manipulation technologies. Here, the effects of microscopic local modification of the magnetic properties, induced by focused-ion-beam intermixing, in NiFe/Au bilayer nanowires on the pinning behavior of domain walls was investigated. The effects of irradiation dose and the length of the irradiated features were investigated experimentally. The results are considered in the context of detailed quasi-static micromagnetic simulations, where the ion-induced modification was represented as a local reduction of the saturation magnetization. Simulations show that domain wall pinning behavior depends on the magnitude of the magnetization change, the length of the modified region, and the domain wall structure. Comparative analysis indicates that reduced saturation magnetisation is not solely responsible for the experimentally observed pinning behavior.

  4. Inflationary power asymmetry from primordial domain walls

    E-Print Network [OSTI]

    Sadra Jazayeri; Yashar Akrami; Hassan Firouzjahi; Adam R. Solomon; Yi Wang

    2014-11-29

    We study the asymmetric primordial fluctuations in a model of inflation in which translational invariance is broken by a domain wall. We calculate the corrections to the power spectrum of curvature perturbations; they are anisotropic and contain dipole, quadrupole, and higher multipoles with non-trivial scale-dependent amplitudes. Inspired by observations of these multipole asymmetries in terms of two-point correlations and variance in real space, we demonstrate that this model can explain the observed anomalous power asymmetry of the cosmic microwave background (CMB) sky, including its characteristic feature that the dipole dominates over higher multipoles. We test the viability of the model and place approximate constraints on its parameters by using observational values of dipole, quadrupole, and octopole amplitudes of the asymmetry measured by a local-variance estimator. We find that a configuration of the model in which the CMB sphere does not intersect the domain wall during inflation provides a good fit to the data. We further derive analytic expressions for the corrections to the CMB temperature covariance matrix, or angular power spectra, which can be used in future statistical analysis of the model in spherical harmonic space.

  5. Inflationary power asymmetry from primordial domain walls

    SciTech Connect (OSTI)

    Jazayeri, Sadra; Akrami, Yashar; Firouzjahi, Hassan; Solomon, Adam R.; Wang, Yi E-mail: yashar.akrami@astro.uio.no E-mail: a.r.solomon@damtp.cam.ac.uk

    2014-11-01

    We study the asymmetric primordial fluctuations in a model of inflation in which translational invariance is broken by a domain wall. We calculate the corrections to the power spectrum of curvature perturbations; they are anisotropic and contain dipole, quadrupole, and higher multipoles with non-trivial scale-dependent amplitudes. Inspired by observations of these multipole asymmetries in terms of two-point correlations and variance in real space, we demonstrate that this model can explain the observed anomalous power asymmetry of the cosmic microwave background (CMB) sky, including its characteristic feature that the dipole dominates over higher multipoles. We test the viability of the model and place approximate constraints on its parameters by using observational values of dipole, quadrupole, and octopole amplitudes of the asymmetry measured by a local-variance estimator. We find that a configuration of the model in which the CMB sphere does not intersect the domain wall during inflation provides a good fit to the data. We further derive analytic expressions for the corrections to the CMB temperature covariance matrix, or angular power spectra, which can be used in future statistical analysis of the model in spherical harmonic space.

  6. Cosmic Microwave Background anisotropies generated by domain wall networks

    E-Print Network [OSTI]

    Sousa, L

    2015-01-01

    We develop a numerical tool for the fast computation of the temperature and polarization power spectra generated by domain wall networks, by extending the publicly available CMBACT code --- that calculates the CMB signatures generated by active sources --- to also describe domain wall networks. In order to achieve this, we adapt the Unconnected Segment model for cosmic strings to also describe domain wall networks, and use it to model the energy-momentum of domain wall networks throughout their cosmological history. We use this new tool to compute and study the TT, EE, TE and BB power spectra generated by standard domain wall networks, and derive a conservative constraint on the energy scale of the domain wall-forming phase transition of $\\upeta <0.92\\,\\,{\\rm MeV}$ (which is a slight improvement over the original Zel'dovich bound of $1\\,\\,{\\rm MeV}$).

  7. Hamilton-Jacobi method for Domain Walls and Cosmologies

    E-Print Network [OSTI]

    Kostas Skenderis; Paul K. Townsend

    2006-12-07

    We use Hamiltonian methods to study curved domain walls and cosmologies. This leads naturally to first order equations for all domain walls and cosmologies foliated by slices of maximal symmetry. For Minkowski and AdS-sliced domain walls (flat and closed FLRW cosmologies) we recover a recent result concerning their (pseudo)supersymmetry. We show how domain-wall stability is consistent with the instability of adS vacua that violate the Breitenlohner-Freedman bound. We also explore the relationship to Hamilton-Jacobi theory and compute the wave-function of a 3-dimensional closed universe evolving towards de Sitter spacetime.

  8. Surface effect on domain wall width in ferroelectrics

    E-Print Network [OSTI]

    2009-10-26

    Oct 26, 2009 ... the domain wall thickness and gradient coefficients in typical ... phase transitions or u. 0 for the second ... tained from the surface energy in the form12. P3 ? 1 ..... Calculated width solid curves of domain wall at level. 0.76 as a ...

  9. Contribution of domain wall networks to the CMB power spectrum

    E-Print Network [OSTI]

    Lazanu, A; Shellard, E P S

    2015-01-01

    We use three domain wall simulations from the radiation era to the late time dark energy domination era based on the PRS algorithm to calculate the energy-momentum tensor components of domain wall networks in an expanding universe. Unequal time correlators in the radiation, matter and cosmological constant epochs are calculated using the scaling regime of each of the simulations. The CMB power spectrum of a network of domain walls is determined. The first ever quantitative constraint for the domain wall surface tension is obtained using a Markov chain Monte Carlo method; an energy scale of domain walls of 0.93 MeV, which is close but below the Zel'dovich bound, is determined.

  10. Domain wall QCD with physical quark masses

    E-Print Network [OSTI]

    RBC,; Blum, T; Boyle, P A; Christ, N H; Frison, J; Garron, N; Hudspith, R J; Izubuchi, T; Janowski, T; Jung, C; Juettner, A; Kelly, C; Kenway, R D; Lehner, C; Marinkovic, M; Mawhinney, R D; McGlynn, G; Murphy, D J; Ohta, S; Portelli, A; Sachrajda, C T; Soni, A

    2014-01-01

    We present results for several light hadronic quantities ($f_\\pi$, $f_K$, $B_K$, $m_{ud}$, $m_s$, $t_0^{1/2}$, $w_0$) obtained from simulations of 2+1 flavor domain wall lattice QCD with large physical volumes and nearly-physical pion masses at two lattice spacings. We perform a short, O(3)%, extrapolation in pion mass to the physical values by combining our new data in a simultaneous chiral/continuum `global fit' with a number of other ensembles with heavier pion masses. We use the physical values of $m_\\pi$, $m_K$ and $m_\\Omega$ to determine the two quark masses and the scale - all other quantities are outputs from our simulations. We obtain results with sub-percent statistical errors and negligible chiral and finite-volume systematics for these light hadronic quantities, including: $f_\\pi$ = 130.2(9) MeV; $f_K$ = 155.5(8) MeV; the average up/down quark mass and strange quark mass in the $\\overline {\\rm MS}$ scheme at 3 GeV, 2.997(49) and 81.64(1.17) MeV respectively; and the neutral kaon mixing parameter, ...

  11. Domain wall QCD with physical quark masses

    E-Print Network [OSTI]

    RBC; UKQCD collaborations; :; T. Blum; P. A. Boyle; N. H. Christ; J. Frison; N. Garron; R. J. Hudspith; T. Izubuchi; T. Janowski; C. Jung; A. Juettner; C. Kelly; R. D. Kenway; C. Lehner; M. Marinkovic; R. D. Mawhinney; G. McGlynn; D. J. Murphy; S. Ohta; A. Portelli; C. T. Sachrajda; A. Soni

    2014-11-25

    We present results for several light hadronic quantities ($f_\\pi$, $f_K$, $B_K$, $m_{ud}$, $m_s$, $t_0^{1/2}$, $w_0$) obtained from simulations of 2+1 flavor domain wall lattice QCD with large physical volumes and nearly-physical pion masses at two lattice spacings. We perform a short, O(3)%, extrapolation in pion mass to the physical values by combining our new data in a simultaneous chiral/continuum `global fit' with a number of other ensembles with heavier pion masses. We use the physical values of $m_\\pi$, $m_K$ and $m_\\Omega$ to determine the two quark masses and the scale - all other quantities are outputs from our simulations. We obtain results with sub-percent statistical errors and negligible chiral and finite-volume systematics for these light hadronic quantities, including: $f_\\pi$ = 130.2(9) MeV; $f_K$ = 155.5(8) MeV; the average up/down quark mass and strange quark mass in the $\\overline {\\rm MS}$ scheme at 3 GeV, 2.997(49) and 81.64(1.17) MeV respectively; and the neutral kaon mixing parameter, $B_K$, in the RGI scheme, 0.750(15) and the $\\overline{\\rm MS}$ scheme at 3 GeV, 0.530(11).

  12. Gapped Domain Walls, Gapped Boundaries and Topological Degeneracy

    E-Print Network [OSTI]

    Tian Lan; Juven Wang; Xiao-Gang Wen

    2014-11-26

    Gapped domain walls, as topological line defects between 2+1D topologically ordered states, are examined. We provide simple criteria to determine the existence of gapped domain walls, which apply to both Abelian and non-Abelian topological orders. Our criteria also determine which 2+1D topological orders must have gapless edge modes, namely which 1+1D global gravitational anomalies ensure gaplessness. Furthermore, we introduce a new mathematical object, the tunneling matrix $\\mathcal W$, whose entries are the fusion-space dimensions $\\mathcal W_{ia}$, to label different types of gapped domain walls. By studying many examples, we find evidence that the tunneling matrices are powerful quantities to classify different types of gapped domain walls. Since a gapped boundary is a gapped domain wall between a bulk topological order and the vacuum, regarded as the trivial topological order, our theory of gapped domain walls inclusively contains the theory of gapped boundaries. In addition, we derive a topological ground state degeneracy formula, applied to arbitrary orientable spatial 2-manifolds with gapped domain walls, including closed 2-manifolds and open 2-manifolds with gapped boundaries.

  13. Calculation of the strange quark mass using domain wall fermions

    E-Print Network [OSTI]

    Tom Blum; Amarjit Soni; Matthew Wingate

    2000-09-18

    We present a first calculation of the strange quark mass using domain wall fermions. This paper contains an overview of the domain wall discretization and a pedagogical presentation of the perturbative calculation necessary for computing the mass renormalization. We combine the latter with numerical simulations to estimate the strange quark mass. Our final result in the quenched approximation is 95(26) MeV in the ${\\bar{MS}}$ scheme at a scale of 2 GeV. We find that domain wall fermions have a small perturbative mass renormalization, similar to Wilson quarks, and exhibit good scaling behavior.

  14. Asymmetric domain walls of small angle in soft ferromagnetic films

    E-Print Network [OSTI]

    Lukas Döring; Radu Ignat

    2014-12-07

    We focus on a special type of domain walls appearing in the Landau-Lifshitz theory for soft ferromagnetic films. These domain walls are divergence-free $S^2$-valued transition layers that connect two directions in $S^2$ (differing by an angle $2\\theta$) and minimize the Dirichlet energy. Our main result is the rigorous derivation of the asymptotic structure and energy of such "asymmetric" domain walls in the limit $\\theta \\to 0$. As an application, we deduce that a supercritical bifurcation causes the transition from symmetric to asymmetric walls in the full micromagnetic model.

  15. Analytical and micromagnetic study of a Neel domain wall 

    E-Print Network [OSTI]

    Rivkin, K.; Romanov, K.; Abanov, Artem; Adamov, Y.; Saslow, W. M.

    2008-01-01

    For ferromagnets with exchange, dipolar interaction, and uniaxial anisotropy, by both analytic methods and micromagnetic simulations we study Neel domain walls in thin ferromagnetic strips of finite width. Comparison of the numerical results...

  16. Collapse of Axionic Domain Wall and Axion Emission

    E-Print Network [OSTI]

    Michiyasu Nagasawa; Masahiro Kawasaki

    1994-05-09

    We examine the collapse of an axion domain wall bounded by an axionic string. It is found that the collapse proceeds quickly and axion domain walls disappear. However axions are emitted in the collapse and its energy density increases during radiation dominated era and contributes significantly to the present mass density of the universe. In particular the axion emitted from the wall can account for the dark matter in the universe for $F_a\\gsim 10^{10}\\GeV$.

  17. Spherical Domain Wall Collapse in a Dust Universe

    E-Print Network [OSTI]

    Norihiro Tanahashi; Chul-Moon Yoo

    2015-05-13

    To clarify observational consequence of bubble nucleations in inflationary era, we analyse dynamics of a spherical domain wall in an expanding universe. We consider a spherical shell of the domain wall with tension $\\sigma$ collapsing in a spherically-symmetric dust universe, which is initially separated into the open Friedmann-Lema\\^itre-Robertson-Walker universe inside the shell and the Einstein-de Sitter universe outside. The domain wall shell collapses due to the tension, and sweeps the dust fluid. The universe after the collapse becomes inhomogeneous and is described by the Lema\\^itre-Tolman-Bondi model. We construct solutions describing this inhomogeneous universe by solving dynamical equations obtained from Israel's junction conditions applied to this system. We find that a black hole forms after the domain wall collapse for any initial condition, and that the black hole mass at the moment of its formation is universally given by $M_{\\rm BH}\\simeq 17 \\sigma/H_{\\rm hc}$, where $H_{\\rm hc}$ is the Hubble parameter at the time when the shell radius becomes equal to the Hubble radius. We also find that the dust fluid is distributed as $\\rho\\propto R^{3/2}$ near the central region after the collapse, where $R$ is the area radius. These features would provide observable signatures of a spherical domain wall generated in the early universe.

  18. Domain wall and isocurvature perturbation problems in axion models

    SciTech Connect (OSTI)

    Kawasaki, Masahiro; Yoshino, Kazuyoshi; Yanagida, Tsutomu T. E-mail: tsutomu.tyanagida@ipmu.jp

    2013-11-01

    Axion models have two serious cosmological problems, domain wall and isocurvature perturbation problems. In order to solve these problems we investigate the Linde's model in which the field value of the Peccei-Quinn (PQ) scalar is large during inflation. In this model the fluctuations of the PQ field grow after inflation through the parametric resonance and stable axionic strings may be produced, which results in the domain wall problem. We study formation of axionic strings using lattice simulations. It is found that in chaotic inflation the axion model is free from both the domain wall and the isocurvature perturbation problems if the initial misalignment angle ?{sub a} is smaller than O(10{sup ?2}). Furthermore, axions can also account for the dark matter for the breaking scale v ? 10{sup 12?16} GeV and the Hubble parameter during inflation H{sub inf}?<10{sup 11?12} GeV in general inflation models.

  19. A Domain Wall Model for Hysteresis in Piezoelectric Materials

    E-Print Network [OSTI]

    A Domain Wall Model for Hysteresis in Piezoelectric Materials Ralph C. Smith Center for Research to attain the full potential of the materials as sensors and actuators in high performance applications design. i #12; 1 Introduction Piezoelectric materials provide the capability for designing actuators

  20. Phenomenological theory of a single domain wall in uniaxial trigonal ferroelectrics: Lithium niobate and lithium tantalate

    E-Print Network [OSTI]

    Gopalan, Venkatraman

    Phenomenological theory of a single domain wall in uniaxial trigonal ferroelectrics: Lithium niobate and lithium tantalate David A. Scrymgeour and Venkatraman Gopalan Department of Materials Science, lithium niobate and lithium tantalate. The contributions to the domain- wall energy from polarization

  1. Speeding up Domain Wall Fermion Algorithms using QCDLAB

    E-Print Network [OSTI]

    Artan Borici

    2007-03-21

    Simulating lattice QCD with chiral fermions and indeed using Domain Wall Fermions continues to be challenging project however large are concurrent computers. One obvious bottleneck is the slow pace of prototyping using the low level coding which prevails in most, if not all, lattice projects. Recently, we came up with a new proposal, namely QCDLAB, a high level language interface, which we believe will boost our endeavours to rapidly code lattice prototype applications in lattice QCD using MATLAB/OCTAVE language and environment. The first version of the software, QCDLAB 1.0 offers the general framework on how to achieve this goal by simulating set of the lattice Schwinger model {\\tt http://phys.fshn.edu.al/qcdlab.html}. In this talk we introduce QCDLAB 1.1, which extends QCDLAB 1.0 capabilities for real world lattice computations with Wilson and Domain Wall fermions.

  2. Stochastic Domain-Wall Depinning in Magnetic Nanowires

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation ofAlbuquerque|SensitiveApril 2,BL4-2StefanLightsource StimulatedStochastic

  3. Stochastic Domain-Wall Depinning in Magnetic Nanowires

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation ofAlbuquerque|SensitiveApril 2,BL4-2StefanLightsource

  4. Stochastic Domain-Wall Depinning in Magnetic Nanowires

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect Photovoltaics -7541C.3X-rays3 Prepared by:'! I ,StimulusConnectStochastic

  5. Stochastic Domain-Wall Depinning in Magnetic Nanowires

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect Photovoltaics -7541C.3X-rays3 Prepared by:'! I

  6. Stochastic Domain-Wall Depinning in Magnetic Nanowires

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect Photovoltaics -7541C.3X-rays3 Prepared by:'! IStochastic

  7. Stochastic Domain-Wall Depinning in Magnetic Nanowires

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect Photovoltaics -7541C.3X-rays3 Prepared by:'! IStochasticStochastic

  8. Stochastic Domain-Wall Depinning in Magnetic Nanowires

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effect Photovoltaics -7541C.3X-rays3 Prepared by:'! IStochasticStochasticStochastic

  9. Proton decay matrix elements with domain-wall fermions

    E-Print Network [OSTI]

    Y. Aoki; C. Dawson; J. Noaki; A. Soni

    2006-09-18

    Hadronic matrix elements of operators relevant to nucleon decay in grand unified theories are calculated numerically using lattice QCD. In this context, the domain-wall fermion formulation, combined with non-perturbative renormalization, is used for the first time. These techniques bring reduction of a large fraction of the systematic error from the finite lattice spacing. Our main effort is devoted to a calculation performed in the quenched approximation, where the direct calculation of the nucleon to pseudoscalar matrix elements, as well as the indirect estimate of them from the nucleon to vacuum matrix elements, are performed. First results, using two flavors of dynamical domain-wall quarks for the nucleon to vacuum matrix elements are also presented to address the systematic error of quenching, which appears to be small compared to the other errors. Our results suggest that the representative value for the low energy constants from the nucleon to vacuum matrix elements are given as |alpha| simeq |beta| simeq 0.01 GeV^3. For a more reliable estimate of the physical low energy matrix elements, it is better to use the relevant form factors calculated in the direct method. The direct method tends to give smaller value of the form factors, compared to the indirect one, thus enhancing the proton life-time; indeed for the pi^0 final state the difference between the two methods is quite appreciable.

  10. Time-resolved observation of fast domain-walls driven by vertical spin currents in short tracks

    SciTech Connect (OSTI)

    Sampaio, Joao; Lequeux, Steven; Chanthbouala, Andre; Cros, Vincent; Grollier, Julie; Matsumoto, Rie; Yakushiji, Kay; Kubota, Hitoshi; Fukushima, Akio; Yuasa, Shinji; Nishimura, Kazumasa; Nagamine, Yoshinori; Maehara, Hiroki; Tsunekawa, Koji

    2013-12-09

    We present time-resolved measurements of the displacement of magnetic domain-walls (DWs) driven by vertical spin-polarized currents in track-shaped magnetic tunnel junctions. In these structures, we observe very high DW velocities (600?m/s) at current densities below 10{sup 7}?A/cm{sup 2}. We show that the efficient spin-transfer torque combined with a short propagation distance allows avoiding the Walker breakdown process and achieving deterministic, reversible, and fast (?1?ns) DW-mediated switching of magnetic tunnel junction elements, which is of great interest for the implementation of fast DW-based spintronic devices.

  11. Nonlinear Spin-Polarized Transport through a Ferromagnetic Domain Wall Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211

    E-Print Network [OSTI]

    Flatte, Michael E.

    of a p-n junction, while two consecutive domain walls correspond to a p-n-p transistor. In a recent paper current is, indeed, possible in the ``p-n-p'' configuration, and can be controlled by a magnetic field

  12. Future of Chiral Extrapolations with Domain Wall Fermions

    E-Print Network [OSTI]

    Stephen R. Sharpe

    2007-06-01

    I discuss the constraints on the lattice spacing, a, the quark masses, m, the box size, L, and particularly the residual mass, m_res, such that one can successfully calculate phenomenologically interesting quantities using Domain Wall fermions (DWF). The constraints on a, m, and L are largely common with other improved fermion discretizations, and I emphasize that the improved chiral symmetry of DWF does not remove the need for simulations with a significant range of lattice parameters. Concerning m_res, I compare the analysis of chiral symmetry breaking to that with Wilson fermions, emphasizing that DWF are better than simply Wilson fermions with each chiral symmetry breaking effect reduced by a common factor. I then discuss the impact of non-zero m_res both on generic hadronic quantities, and on matrix elements which involve mixing with lower dimension operators.

  13. Investigation of dominant spin wave modes by domain walls collision

    SciTech Connect (OSTI)

    Ramu, M.; Purnama, I.; Goolaup, S.; Chandra Sekhar, M.; Lew, W. S.

    2014-06-28

    Spin wave emission due to field-driven domain wall (DW) collision has been investigated numerically and analytically in permalloy nanowires. The spin wave modes generated are diagonally symmetric with respect to the collision point. The non-propagating mode has the highest amplitude along the middle of the width. The frequency of this mode is strongly correlated to the nanowire geometrical dimensions and is independent of the strength of applied field within the range of 0.1?mT to 1?mT. For nanowire with film thickness below 5?nm, a second spin wave harmonic mode is observed. The decay coefficient of the spin wave power suggests that the DWs in a memory device should be at least 300?nm apart for them to be free of interference from the spin waves.

  14. Charm physics with physical light and strange quarks using domain wall fermions

    E-Print Network [OSTI]

    Peter A. Boyle; Luigi Del Debbio; Nicolas Garron; Andreas Juttner; Ava Khamseh; Marina Marinkovic; Francesco Sanfilippo; Justus T. Tsang

    2015-02-03

    We present a study of charm physics using RBC/UKQCD 2+1 flavour physical point domain wall fermion ensembles for the light quarks as well as for the valence charm quark. After a brief motivation of domain wall fermions as a suitable heavy quark discretisation we will show first results for masses and matrix elements.

  15. Charm physics with physical light and strange quarks using domain wall fermions

    E-Print Network [OSTI]

    Boyle, Peter A; Garron, Nicolas; Juttner, Andreas; Khamseh, Ava; Marinkovic, Marina; Sanfilippo, Francesco; Tsang, Justus T

    2015-01-01

    We present a study of charm physics using RBC/UKQCD 2+1 flavour physical point domain wall fermion ensembles for the light quarks as well as for the valence charm quark. After a brief motivation of domain wall fermions as a suitable heavy quark discretisation we will show first results for masses and matrix elements.

  16. Molecular structure and motion in zero field magnetic resonance

    SciTech Connect (OSTI)

    Jarvie, T.P.

    1989-10-01

    Zero field magnetic resonance is well suited for the determination of molecular structure and the study of motion in disordered materials. Experiments performed in zero applied magnetic field avoid the anisotropic broadening in high field nuclear magnetic resonance (NMR) experiments. As a result, molecular structure and subtle effects of motion are more readily observed.

  17. Motion Caused by Magnetic Field in Lobachevsky Space

    E-Print Network [OSTI]

    V. V. Kudryashov; Yu. A. Kurochkin; E. M. Ovsiyuk; V. M. Red'kov

    2010-06-27

    We study motion of a relativistic particle in the 3-dimensional Lobachevsky space in the presence of an external magnetic field which is analogous to a constant uniform magnetic field in the Euclidean space. Three integrals of motion are found and equations of motion are solved exactly in the special cylindrical coordinates. Motion on surface of the cylinder of constant radius is considered in detail.

  18. Energy-momentum balance in particle - domain wall perforating collision

    E-Print Network [OSTI]

    D. V. Gal'tsov; E. Yu. Melkumova; P. A. Spirin

    2015-02-10

    We investigate the energy-momentum balance in the perforating collision of a point particle with an infinitely thin planar domain wall within the linearized gravity in arbitrary dimensions. Since the metric of the wall increases with distance, the wall and the particle are never free, and their energy-momentum balance involves not only the instantaneous kinetic momenta, but also the non-local contribution of gravitational stresses. However, careful analysis shows that the stresses can be unambiguously divided between the colliding objects leading to definition of the gravitationally dressed momenta. These take into account for gravity in the same way as the potential energy does in the non-relativistic theory, but our treatment is fully relativistic. Another unusual feature of our problem is the non-vanishing flux of the total energy-momentum tensor through the lateral surface of the world tube. In this case the zero divergence of the energy-momentum tensor does not imply conservation of the total momentum defined as the integral over the space-like section of the tube. But one can still define the conservation low infinitesimally, passing to time derivatives of the momenta. Using this definition we establish the momentum balance in terms of the dressed particle and wall momenta.

  19. Quantum Fusion of Strings (Flux Tubes) and Domain Walls

    E-Print Network [OSTI]

    S. Bolognesi; M. Shifman; M. B. Voloshin

    2009-05-20

    We consider formation of composite strings and domain walls as a result of fusion of two elementary objects (elementary strings in the first case and elementary walls in the second) located at a distance from each other. The tension of the composite object T_2 is assumed to be less than twice the tension of the elementary object T_1, so that bound states are possible. If in the initial state the distance d between the fusing strings or walls is much larger than their thickness and satisfies the conditions T_1 d^2 >> 1 (in the string case) and T_1 d^3 >> 1 (in the wall case), the problem can be fully solved quasiclassically. The fusion probability is determined by the first, "under the barrier" stage of the process. We find the bounce configuration and its extremal action S_B. In the wall problem e^{-S_B} gives the fusion probability per unit time per unit area. In the string case, due to a logarithmic infrared divergence, the problem is well formulated only for finite-length strings. The fusion probability per unit time can be found in the limit in which the string length is much larger than the distance between two merging strings.

  20. Domain walls and vortices in linearly coupled systems

    E-Print Network [OSTI]

    Dror, Nir; Zeng, Jianhua

    2011-01-01

    We investigate 1D and 2D radial domain-wall (DW) states in the system of two nonlinear-Schr\\"{o}dinger/Gross-Pitaevskii equations, which are coupled by the linear mixing and by the nonlinear XPM (cross-phase-modulation). The system has straightforward applications to two-component Bose-Einstein condensates, and to the bimodal light propagation in nonlinear optics. In the former case, the two components represent different hyperfine atomic states, while in the latter setting they correspond to orthogonal polarizations of light. Conditions guaranteeing the stability of flat continuous wave (CW) asymmetric bimodal states are established, followed by the study of families of the corresponding DW patterns. Approximate analytical solutions for the DWs are found near the point of the symmetry-breaking bifurcation of the CW states. An exact DW solution is produced for ratio 3:1 of the XPM and SPM coefficients. The DWs between flat asymmetric states, which are mirror images to each other, are completely stable, and al...

  1. Domain Wall Model in the Galactic Bose-Einstein Condensate Halo

    E-Print Network [OSTI]

    J. C. C. de Souza; M. O. C. Pires

    2013-05-22

    We assume that the galactical dark matter halo, considered composed of an axionlike particles Bose-Einstein condensate \\cite{pir12}, can present topological defects, namely domain walls, arising as the dark soliton solution for the Gross-Pitaevskii equation in a self-graviting potential. We investigate the influence that such substructures would have in the gravitational interactions within a galaxy. We find that, for the simple domain wall model proposed, the effects are too small to be identified, either by means of a local measurement of the gradient of the gravitational field or by analysing galaxy rotation curves. In the first case, the gradient of the gravitational field in the vicinity of the domain wall would be $10^{-31}\\; (m/s^2)/m$. In the second case, the ratio of the tangential velocity correction of a star due to the presence of the domain wall to the velocity in the spherical symmetric case would be $10^{-8}$.

  2. Motion of charged particles in ABC magnetic fields Alejandro Luque #

    E-Print Network [OSTI]

    Motion of charged particles in ABC magnetic fields Alejandro Luque # Departament de Matemâ?? atica consequences of our study are the existence of confinement regions of charges near some magnetic lines, magnetic field, Hamiltonian dynamical system, el­ liptic equilibrium point, quasi­periodic solution

  3. Modeling Left Ventricle Wall Motion Using Tagged Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Alenezy, Mohammed D.

    2009-04-17

    A two-parameter computational model is proposed for the study of the regional motion of the left ventricle (LV) wall using tagged magnetic resonance imaging (tMRI) data. In this model, the LV wall motion is mathematically decomposed into two...

  4. Substrate Clamping Effects on Irreversible Domain Wall Dynamics in Lead Zirconate Titanate Thin Films

    SciTech Connect (OSTI)

    Griggio, Flavio [ORNL; Jesse, Stephen [ORNL; Kumar, Amit [ORNL; Ovchinnikov, Oleg S [ORNL; Kim, H. [Pennsylvania State University, University Park, PA; Jackson, T. N. [Pennsylvania State University, University Park, PA; Damjanovic, Dragan [ORNL; Kalinin, Sergei V [ORNL; Trolier-Mckinstry, Susan E [ORNL

    2012-01-01

    The role of long-range strain interactions on domain wall dynamics is explored through macroscopic and local measurements of nonlinear behavior in mechanically clamped and released polycrystalline lead zirconate-titanate (PZT) films. Released films show a dramatic change in the global dielectric nonlinearity and its frequency dependence as a function of mechanical clamping. Furthermore, we observe a transition from strong clustering of the nonlinear response for the clamped case to almost uniform nonlinearity for the released film. This behavior is ascribed to increased mobility of domain walls. These results suggest the dominant role of collective strain interactions mediated by the local and global mechanical boundary conditions on the domain wall dynamics. The work presented in this Letter demonstrates that measurements on clamped films may considerably underestimate the piezoelectric coefficients and coupling constants of released structures used in microelectromechanical systems, energy harvesting systems, and microrobots.

  5. Lattice QCD with domain wall quarks and applications to weak matrix elements

    E-Print Network [OSTI]

    T. Blum; A. Soni Brookhaven National Lab

    1997-10-13

    Using domain wall fermions, we estimate $B_K(\\mu\\approx 2 GeV)=0.628(47)$ in quenched QCD which is consistent with previous calculations. At $\\gbeta=6.0$ and 5.85 we find the ratio $f_K/m_\\rho$ in agreement with the experimental value, within errors. These results support expectations that $O(a)$ errors are exponentially suppressed in low energy ($E\\ll a^{-1}$) observables, and indicate that domain wall fermions have good scaling behavior at relatively strong couplings. We also demonstrate that the axial current numerically satisfies the lattice analog of the usual continuum axial Ward identity.

  6. In situ measurement of increased ferroelectric/ferroelastic domain wall

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby aLED Street LightingFrom theHighI _ _1motion in declamped

  7. Analysis of ultra-narrow ferromagnetic domain walls

    SciTech Connect (OSTI)

    Jenkins, Catherine; Paul, David

    2012-01-10

    New materials with high magnetic anisotropy will have domains separated by ultra-narrow ferromagnetic walls with widths on the order of a few unit cells, approaching the limit where the elastic continuum approximation often used in micromagnetic simulations is accurate. The limits of this approximation are explored, and the static and dynamic interactions with intrinsic crystalline defects and external driving #12;elds are modeled. The results developed here will be important when considering the stability of ultra-high-density storage media.

  8. The effect of thermal activation on the coercivity of domain walls L. LopezDiaz a)

    E-Print Network [OSTI]

    Moro, Esteban

    The effect of thermal activation on the coercivity of domain walls L. Lopez­Diaz a) Departamento de of temperature was taken into account. However, it is well known that thermal activation over finite energy the inclusion and, consequently, the coercivity is low­ ered. In this article, the effect of thermal activation

  9. The effect of thermal activation on the coercivity of domain walls L. Lopez-Diaza)

    E-Print Network [OSTI]

    Moro, Esteban

    The effect of thermal activation on the coercivity of domain walls L. Lopez-Diaza) Departamento de of temperature was taken into account. However, it is well known that thermal activation over finite energy the inclusion and, consequently, the coercivity is low- ered. In this article, the effect of thermal activation

  10. Thermoelectric Effect across the Metal-Insulator Domain Walls in VO2

    E-Print Network [OSTI]

    Wu, Junqiao

    Thermoelectric Effect across the Metal-Insulator Domain Walls in VO2 Microbeams J. Cao,,, W. Fan-performance thermoelectric materials are currently one of the focuses in materials research for energy conversion technologies.1-4 A good thermoelectric material should have a relatively high thermopower (Seebeck coefficient

  11. B-physics with dynamical domain-wall light quarks and relativistic b-quarks

    E-Print Network [OSTI]

    Ruth S. Van de Water; Oliver Witzel

    2011-01-24

    We report on our progress in calculating the B-meson decay constants and B^0-bar B^0 mixing parameters using domain-wall light quarks and relativistic b-quarks. We present our computational method and show some preliminary results obtained on the coarser (a approx 0.11fm) 24^3 lattices. This work is presented on behalf of the RBC and UKQCD collaborations.

  12. CP violation in the models of fermion localization on a domain wall (brane)

    E-Print Network [OSTI]

    Alexander A. Andrianov; Vladimir A. Andrianov; Oleg O. Novikov

    2013-03-31

    A brief survey of fermion localization mechanism on a domain wall ("thick brane") generated by a topologically nontrivial vacuum configuration of scalar fields is given. The extension of scalar fields interaction with fermions which supplies fermions with an axial mass is proposed. For several flavors and generations of fermions this extension can entail the Cabibbo-Kobayashi-Maskawa matrix of the Standard Model. As well the model with two scalar doublets which provide a supplementary CP violation mechanism is considered.

  13. Nucleon structure from mixed action calculations using 2+1 flavors of asqtad sea and domain wall valence fermions

    E-Print Network [OSTI]

    Bratt, Jonathan D.

    We present high statistics results for the structure of the nucleon from a mixed-action calculation using 2+1 flavors of asqtad sea and domain-wall valence fermions. We perform extrapolations of our data based on different ...

  14. One-Flavor Algorithms for Simulation of Lattice QCD with Domain-Wall Fermion: EOFA versus RHMC

    E-Print Network [OSTI]

    Yu-Chih Chen; Ting-Wai Chiu

    2014-12-02

    We compare the performances of the exact one-flavor algorithm (EOFA) and the rational hybrid Monte Carlo algorithm (RHMC), for dynamical simulations of lattice QCD with domain-wall fermion.

  15. The static quark potential in 2+1 flavour Domain Wall QCD from QCDOC

    E-Print Network [OSTI]

    Koichi Hashimoto; Taku Izubuchi; Jun Noaki; for the RBC-UKQCD Collaborations

    2005-10-14

    We report our present status of on-going project on the measurement of the static quark potential in 2+1 flavour domain wall QCD with various improved gauge actions and couplings. Lattice spacing determined from Sommer scale on these ensembles are from 1.6 GeV to 2.0 GeV for $16^3 \\times 32$ lattice with fifth dimension size 8. We also examine size of discretization error from scaling of a pair of dimensionless quantities, $(r_0 m_\\pi)^2$ and $r_0 m_\\rho$, and found small scaling violation.

  16. The relation between the waveguide and overlap implementations of Kaplan's domain wall fermions

    E-Print Network [OSTI]

    Maarten Golterman; Yigal Shamir

    1995-09-26

    Recently, Narayanan and Neuberger proposed that the fermion determinant for a lattice chiral gauge theory be defined by an overlap formula. The motivation for that formula comes from Kaplan's five dimensional lattice domain wall fermions. In the case that the target continuum theory contains $4n$ chiral families, we show that the effective action defined by overlap formula is identical to the effective action of a modified waveguide model that has extra bosonic ghost fields. This raises serious questions about the viability of the overlap formula for defining chiral gauge theories on the lattice.

  17. Domain wall fermion calculation of nucleon g_A/g_V

    E-Print Network [OSTI]

    Tom Blum; Shigemi Ohta; Shoichi Sasaki

    2000-11-01

    We present a preliminary domain-wall fermion lattice-QCD calculation of isovector vector and axial charges, g_V and g_A, of the nucleon. Since the lattice renormalizations, Z_V and Z_A, of the currents are identical with DWF, the lattice ratio (g_A/g_V)^{lattice} directly yields the continuum value. Indeed Z_V determined from the matrix element of the vector current agrees closely with Z_A from a non-perturbative renormalization study of quark bilinears. We also obtain spin related quantities Delta-q/g_V and delta-q/g_V.

  18. Bistable illusory rebound motion: Event-related functional magnetic resonance imaging of perceptual states and switches

    E-Print Network [OSTI]

    Bucci, David J.

    Bistable illusory rebound motion: Event-related functional magnetic resonance imaging of perceptual of a recently discovered visual illusion that we call Fillusory rebound motion_ (IRM) are described. This illusion is remarkable because motion is perceived in the absence of any net motion energy in the stimulus

  19. Nucleon axial charge from quenched lattice QCD with domain wall fermions

    E-Print Network [OSTI]

    Shoichi Sasaki; Kostas Orginos; Shigemi Ohta; Tom Blum; for the RBCK Collaboration

    2003-07-18

    We present a quenched lattice calculation of the nucleon isovector vector and axial-vector charges gV and gA. The chiral symmetry of domain wall fermions makes the calculation of the nucleon axial charge particularly easy since the Ward-Takahashi identity requires the vector and axial-vector currents to have the same renormalization, up to lattice spacing errors of order O(a^2). The DBW2 gauge action provides enhancement of the good chiral symmetry properties of domain wall fermions at larger lattice spacing than the conventional Wilson gauge action. Taking advantage of these methods and performing a high statistics simulation, we find a significant finite volume effect between the nucleon axial charges calculated on lattices with (1.2 fm)^3 and (2.4 fm)^3 volumes (with lattice spacing, a, of about 0.15 fm). On the large volume we find gA = 1.212 +/- 0.027(statistical error) +/- 0.024(normalization error). The quoted systematic error is the dominant (known) one, corresponding to current renormalization. We discuss other possible remaining sources of error. This theoretical first principles calculation, which does not yet include isospin breaking effects, yields a value of gA only a little bit below the experimental one, 1.2670 +/- 0.0030.

  20. Cosmic bubble and domain wall instabilities II: Fracturing of colliding walls

    E-Print Network [OSTI]

    Jonathan Braden; J. Richard Bond; Laura Mersini-Houghton

    2015-06-09

    We study collisions between nearly planar domain walls including the effects of small initial nonplanar fluctuations. These perturbations represent the small fluctuations that must exist in a quantum treatment of the problem. In a previous paper, we demonstrated that at the linear level a subset of these fluctuations experience parametric amplification as a result of their coupling to the planar symmetric background. Here we study the full three-dimensional nonlinear dynamics using lattice simulations, including both the early time regime when the fluctuations are well described by linear perturbation theory as well as the subsequent stage of fully nonlinear evolution. We find that the nonplanar fluctuations have a dramatic effect on the overall evolution of the system. Specifically, once these fluctuations begin to interact nonlinearly the split into a planar symmetric part of the field and the nonplanar fluctuations loses its utility. At this point the colliding domain walls dissolve, with the endpoint of this being the creation of a population of oscillons in the collision region. The original (nearly) planar symmetry has been completely destroyed at this point and an accurate study of the system requires the full three-dimensional simulation.

  1. Motion of guiding center drift atoms in the electric and magnetic field of a Penning trap

    E-Print Network [OSTI]

    California at San Diego, University of

    Motion of guiding center drift atoms in the electric and magnetic field of a Penning trap S. G discusses the motion of the weakly bound atoms in the electric and magnetic field of the plasma and trap in the magnetic and electric field of the trap. Because the binding is so weak, even a modest electric field

  2. Domain Walls and Anchoring Transitions Mimicking Nematic Biaxiality in the Oxadiazole Bent-Core Liquid Crystal C7

    E-Print Network [OSTI]

    Kim, Young-ki; Xiang, Jie; Shin, Sung-Tae; Lavrentovich, Oleg D

    2015-01-01

    We investigate the origin of secondary disclinations that were recently described as a new evidence of a biaxial nematic phase in an oxadiazole bent-core thermotropic liquid crystal C7. With an assortment of optical techniques such as polarizing optical microscopy, LC PolScope, and fluorescence confocal polarizing microscopy, we demonstrate that the secondary disclinations represent non-singular domain walls formed in an uniaxial nematic during the surface anchoring transition, in which surface orientation of the director changes from tangential (parallel to the bounding plates) to tilted. Each domain wall separates two regions with the director tilted in opposite azimuthal directions. At the centre of the wall, the director remains parallel to the bonding plates. The domain walls can be easily removed by applying a modest electric field. The anchoring transition is explained by the balance of (a) the intrinsic perpendicular surface anchoring produced by the polyimide aligning layer and (b) tangential alignme...

  3. In-situ TEM observation of the interaction between magnetic domain walls and twin domain walls below the Verwey transition in magnetite

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    transition is first-order in character and proceeds by the rapid movement of an abrupt phase interface of the monoclinic phase. On cooling through the transition, the [001] easy axis of the monoclinic phase may have performed an in-situ study of the cubic to monoclinic phase transition in synthetic multi

  4. GPU-Based Conjugate Gradient Solver for Lattice QCD with Domain-Wall Fermions

    E-Print Network [OSTI]

    Ting-Wai Chiu; Tung-Han Hsieh; Yao-Yuan Mao; Kenji Ogawa

    2011-01-02

    We present the first GPU-based conjugate gradient (CG) solver for lattice QCD with domain-wall fermions (DWF). It is well-known that CG is the most time-consuming part in the Hybrid Monte Carlo simulation of unquenched lattice QCD, which becomes even more computational demanding for lattice QCD with exact chiral symmetry. We have designed a CG solver for the general 5-dimensional DWF operator on NVIDIA CUDA architecture with mixed-precision, using the defect correction as well as the reliable updates algorithms. We optimize our computation by even-odd preconditioning in the 4D space-time lattice, plus several innovative techniques for CUDA kernels. For NVIDIA GeForce GTX 285/480, our CG solver attains 180/233 Gflops (sustained).

  5. GPU-Based Conjugate Gradient Solver for Lattice QCD with Domain-Wall Fermions

    E-Print Network [OSTI]

    Chiu, Ting-Wai; Mao, Yao-Yuan; Ogawa, Kenji

    2010-01-01

    We present the first GPU-based conjugate gradient (CG) solver for lattice QCD with domain-wall fermions (DWF). It is well-known that CG is the most time-consuming part in the Hybrid Monte Carlo simulation of unquenched lattice QCD, which becomes even more computational demanding for lattice QCD with exact chiral symmetry. We have designed a CG solver for the general 5-dimensional DWF operator on NVIDIA CUDA architecture with mixed-precision, using the defect correction as well as the reliable updates algorithms. We optimize our computation by even-odd preconditioning in the 4D space-time lattice, plus several innovative techniques for CUDA kernels. For NVIDIA GeForce GTX 285/480, our CG solver attains 180/233 Gflops (sustained).

  6. Nucleon form factors with 2+1 flavor dynamical domain-wall fermions

    E-Print Network [OSTI]

    Takeshi Yamazaki; Yasumichi Aoki; Tom Blum; Huey-Wen Lin; Shigemi Ohta; Shoichi Sasaki; Robert Tweedie; James Zanotti

    2009-04-14

    We report our numerical lattice QCD calculations of the isovector nucleon form factors for the vector and axialvector currents: the vector, induced tensor, axialvector, and induced pseudoscalar form factors. The calculation is carried out with the gauge configurations generated with N_f=2+1 dynamical domain wall fermions and Iwasaki gauge actions at beta = 2.13, corresponding to a cutoff 1/a = 1.73 GeV, and a spatial volume of (2.7 fm)^3. The up and down quark masses are varied so the pion mass lies between 0.33 and 0.67 GeV while the strange quark mass is about 12% heavier than the physical one. We calculate the form factors in the range of momentum transfers, 0.2 6 is required to ensure that finite volume effects are below 1%.

  7. Magnetic domain walls for on-chip transport and detection of superparamagnetic beads

    E-Print Network [OSTI]

    Rapoport, Elizabeth Ashera

    2014-01-01

    Surface-functionalized superparamagnetic (SPM) microbeads are of great interest in biomedical research and diagnostic device engineering for tagging, manipulating, and detecting chemical and biological species in a fluid ...

  8. Effect of surface roughness on magnetic domain wall thickness, domain size, and coercivity

    E-Print Network [OSTI]

    Wang, Gwo-Ching

    , Rensselaer Polytechnic Institute, Troy, New York 12180-3590 G. Palasantzas and J. Th. M. De Hosson Department nm thick deposited on plasma etched Si 100 substrates showed that, by increasing surface rough- ness nearly linearly with film thickness. Such an increase of the thickness fluctuations5 was attributed

  9. Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATION PLAN FOR THE

  10. Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATION PLAN FOR THEVortices Influence of Domain

  11. Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy,ImpactScientific andIndividualEventInexpensive

  12. Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy,ImpactScientific andIndividualEventInexpensiveVortices

  13. Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy,ImpactScientific

  14. Direct Observation of Nanoscale Peltier and Joule Effects at Metal-Insulator Domain Walls in Vanadium Dioxide Nanobeams

    E-Print Network [OSTI]

    Wu, Junqiao

    Direct Observation of Nanoscale Peltier and Joule Effects at Metal- Insulator Domain Walls localized alternating Peltier heating and cooling as well as Joule heating concentrated at the M-I domain the monoclinic phase identification. KEYWORDS: Vanadium dioxide, thermoreflectance microscopy, Peltier effect

  15. The finite temperature QCD using 2+1 flavors of domain wall fermions at Nt = 8

    SciTech Connect (OSTI)

    Cheng, M; Christ, N H; Li, M; Mawhinney, R D; Renfrew, D; Hegde, P; Karsch, F; Lin, M; Vranas, P

    2009-11-30

    We study the region of the QCD phase transition using 2+1 flavors of domain wall fermions (DWF) and a 16{sup 3} x 8 lattice volume with a fifth dimension of L{sub s} = 32. The disconnected light quark chiral susceptibility, quark number susceptibility and the Polyakov loop suggest a chiral and deconfining crossover transition lying between 155 and 185 MeV for our choice of quark mass and lattice spacing. In this region the lattice scale deduced from the Sommer parameter r{sub 0} is a{sup -1} {approx} 1.3 GeV, the pion mass is {approx} 300 MeV and the kaon mass is approximately physical. The peak in the chiral susceptibility implies a pseudo critical temperature T{sub c} = 171(10)(17) MeV where the first error is associated with determining the peak location and the second with our unphysical light quark mass and non-zero lattice spacing. The effects of residual chiral symmetry breaking on the chiral condensate and disconnected chiral susceptibility are studied using several values of the valence L{sub s}.

  16. Finite Temperature QCD Using 2 þ 1 Flavors of Domain Wall Fermions at Nt ¼ 8

    SciTech Connect (OSTI)

    Karsch, F.; Lim, M; Cheng, M; Christ, N; Hegde, P.; Li, L.; Mawhinney, R.; Renfrew, D.; Vranas, P.

    2010-03-30

    We study the region of the QCD phase transition using 2 + 1 flavors of domain wall fermions and a 16{sup 3} x 8 lattice volume with a fifth dimension of L{sub s} = 32. The disconnected light quark chiral susceptibility, quark number susceptibility, and the Polyakov loop suggest a chiral and deconfining crossover transition lying between 155 and 185 MeV for our choice of quark mass and lattice spacing. In this region the lattice scale deduced from the Sommer parameter r{sub 0} is a{sup -1} {approx} 1.3 GeV, the pion mass is {approx} 300 MeV, and the kaon mass is approximately physical. The peak in the chiral susceptibility implies a pseudocritical temperature T{sub c} = 171(10)(17) MeV where the first error is associated with determining the peak location and the second with our unphysical light quark mass and nonzero lattice spacing. The effects of residual chiral symmetry breaking on the chiral condensate and disconnected chiral susceptibility are studied using several values of the valence L{sub s}.

  17. A Lattice Study of the Nucleon Excited States with Domain Wall Fermions

    E-Print Network [OSTI]

    Shoichi Sasaki; Tom Blum; Shigemi Ohta

    2002-01-16

    We present results of our numerical calculation of the mass spectrum for isospin one-half and spin one-half non-strange baryons, i.e. the ground and excited states of the nucleon, in quenched lattice QCD. We use a new lattice discretization scheme for fermions, domain wall fermions, which possess almost exact chiral symmetry at non-zero lattice spacing. We make a systematic investigation of the negative-parity $N^*$ spectrum by using two distinct interpolating operators at $\\beta=6/g^2=6.0$ on a $16^3 \\times 32 \\times 16$ lattice. The mass estimates extracted from the two operators are consistent with each other. The observed large mass splitting between this state, $N^*(1535)$, and the positive-parity ground state, the nucleon N(939), is well reproduced by our calculations. We have also calculated the mass of the first positive-parity excited state and found that it is heavier than the negative-parity excited state for the quark masses studied.

  18. Motion of charged particles in magnetic fields created by symmetric configurations of wires

    E-Print Network [OSTI]

    . Furthermore, the circular wire system can be interpreted as a simplified model of the levitated magnetic, this paper illustrates that very simple magnetic con- figurations can give rise to complicated, even chaoticMotion of charged particles in magnetic fields created by symmetric configurations of wires Jacobo

  19. Continuum limit physics from 2+1 flavor domain wall QCD

    SciTech Connect (OSTI)

    Aoki, Y.; Izubuchi, T.; Arthur, R.; Blum, T.; Boyle, P.A.; Brommel, D.; Christ, N.H.; Dawson, C.; Flynn, J.M.; Jin, X.Y.; Jung, C.; Kelly, C.; Li, M.; Lichtl, A.; Lightman, M.; Lin, M.F.; Mawhinney, R.D.; Maynard,C.M.; Ohta, S.; Pendleton, B.J.; Sachrajda, C.T.; Scholz, E.E.; Soni, A.; Wennekers, J.; Zanotti, J.M.; Zhou, R.

    2011-04-22

    We present physical results obtained from simulations using 2+1 flavors of domain wall quarks and the Iwasaki gauge action at two values of the lattice spacing a, [a{sup -1} = 1.73(3) GeV and a{sup -1} = 2.28(3) GeV]. On the coarser lattice, with 24{sup 3} x 64 x 16 points (where the 16 corresponds to L{sub s}, the extent of the 5th dimension inherent in the domain wall fermion formulation of QCD), the analysis of C. Allton et al. Phys. Rev. D 78 is extended to approximately twice the number of configurations. The ensembles on the finer 32{sup 3} x 64 x 16 lattice are new. We explain in detail how we use lattice data obtained at several values of the lattice spacing and for a range of quark masses in combined continuum-chiral fits in order to obtain results in the continuum limit and at physical quark masses. We implement this procedure for our data at two lattice spacings and with unitary pion masses in the approximate range 290-420 MeV (225-420 MeV for partially quenched pions). We use the masses of the {pi} and K mesons and the {Omega} baryon to determine the physical quark masses and the values of the lattice spacing. While our data in the mass ranges above are consistent with the predictions of next-to-leading order SU(2) chiral perturbation theory, they are also consistent with a simple analytic ansatz leading to an inherent uncertainty in how best to perform the chiral extrapolation that we are reluctant to reduce with model-dependent assumptions about higher order corrections. In some cases, particularly for f{sub {pi}}, the pion leptonic decay constant, the uncertainty in the chiral extrapolation dominates the systematic error. Our main results include f{sub {pi}} = 124(2){sub stat}(5){sub syst} MeV, f{sub K}/f{sub {pi}} = 1.204(7)(25) where f{sub K} is the kaon decay constant, m{sub s}{sup MS} (2 GeV) = (96.2 {+-} 2.7) MeV and m{sub ud}{sup MS} (2 GeV) = (3.59 {+-} 0.21) MeV (m{sub s}/m{sub ud} = 26.8 {+-} 1.4) where m{sub s} and m{sub ud} are the mass of the strange quark and the average of the up and down quark masses, respectively, [{Sigma}{sup MS} (2 GeV)]{sup 1/3} = 256(6) MeV, where {Sigma} is the chiral condensate, the Sommer scale r{sub 0} = 0.487(9) fm and r{sub 1} = 0.333(9) fm.

  20. Nucleon isovector structure functions in (2+1)-flavor QCD with domain wall fermions

    E-Print Network [OSTI]

    Yasumichi Aoki; Tom Blum; Huey-Wen Lin; Shigemi Ohta; Shoichi Sasaki; Robert Tweedie; Takeshi Yamazaki; James Zanotti

    2010-03-17

    We report on numerical lattice QCD calculations of some of the low moments of the nucleon structure functions. The calculations are carried out with gauge configurations generated by the RBC and UKQCD collaborations with (2+1)-flavors of dynamical domain wall fermions and the Iwasaki gauge action ($\\beta = 2.13$). The inverse lattice spacing is $a^{-1} = 1.73$ GeV, and two spatial volumes of ((2.7{\\rm fm})^3) and ((1.8 {\\rm fm})^3) are used. The up and down quark masses are varied so the pion mass lies between 0.33 and 0.67 GeV while the strange mass is about 12 % heavier than the physical one. The structure function moments we present include fully non-perturbatively renormalized iso-vector quark momentum fraction, (_{u-d}), helicity fraction, (_{\\Delta u - \\Delta d}), and transversity, (_{\\delta u - \\delta d}), as well as an unrenormalized twist-3 coefficient, (d_1). The ratio of the momentum to helicity fractions, (_{u-d}/_{\\Delta u - \\Delta d}), does not show dependence on the light quark mass and agrees well with the value obtained from experiment. Their respective absolute values, fully renormalized, show interesting trends toward their respective experimental values at the lightest quark mass. A prediction for the transversity, (0.7 _{\\delta u -\\delta d} < 1.1), in the (\\bar{\\rm MS}) scheme at 2 GeV is obtained. The twist-3 coefficient, (d_1), though yet to be renormalized, supports the perturbative Wandzura-Wilczek relation.

  1. Nucleon structure with two flavors of dynamical domain-wall fermions

    E-Print Network [OSTI]

    Huey-Wen Lin; Tom Blum; Shigemi Ohta; Shoichi Sasaki; Takeshi Yamazaki

    2008-02-06

    We present a numerical lattice quantum chromodynamics calculation of isovector form factors and the first few moments of the isovector structure functions of the nucleon. The calculation employs two degenerate dynamical flavors of domain-wall fermions, resulting in good control of chiral symmetry breaking. Non-perturbative renormalization of the relevant quark currents is performed where necessary. The inverse lattice spacing, $a^{-1}$, is about 1.7 GeV. We use degenerate up and down dynamical quark masses around 1, 3/4 and 1/2 the strange quark mass. The physical volume of the lattice is about $(1.9{fm})^3$. The ratio of the isovector vector to axial charges, $g_A/g_V$, trends a bit lower than the experimental value as the quark mass is reduced toward the physical point. We calculate the momentum-transfer dependences of the isovector vector, axial, induced tensor and induced pseudoscalar form factors. The Goldberger-Treiman relation holds at low momentum transfer and yields a pion-nucleon coupling, $g_{\\pi NN} = 15.5(1.4)$, where the quoted error is only statistical. We find that the flavor non-singlet quark momentum fraction $_{u-d}$ and quark helicity fraction $_{\\Delta u-\\Delta d}$ overshoot their experimental values after linear chiral extrapolation. We obtain the transversity, $_{\\delta u-\\delta d} = 0.93(6)$ in $\\bar{\\rm MS}$ at 2 GeV and a twist-3 polarized moment, $d_1$, appears small, suggesting that the Wandzura-Wilczek relation holds approximately. We discuss the systematic errors in the calculation, with particular attention paid to finite-volume effects, excited-state contamination, and chiral extrapolations.

  2. Regulation and large motion tracking for active magnetic bearing system using sliding mode control 

    E-Print Network [OSTI]

    Sun, Guangyoung

    1999-01-01

    In this thesis, sliding mode control (SMC), one of nonlinear control theories is designed based on the original nonlinear active magnetic bearing (AMB) system with 4 degrees of freedom. It is applied to the regulation/stabilization and large motion...

  3. Control strategies and motion planning for nanopositioning applications with multi-axis magnetic-levitation instruments 

    E-Print Network [OSTI]

    Shakir, Huzefa

    2007-09-17

    This dissertation is the first attempt to demonstrate the use of magnetic-levitation (maglev) positioners for commercial applications requiring nanopositioning. The key objectives of this research were to devise the control strategies and motion...

  4. Domain Walls and Anchoring Transitions Mimicking Nematic Biaxiality in the Oxadiazole Bent-Core Liquid Crystal C7

    E-Print Network [OSTI]

    Young-ki Kim; Greta Cukrov; Jie Xiang; Sung-Tae Shin; Oleg D. Lavrentovich

    2015-03-23

    We investigate the origin of secondary disclinations that were recently described as a new evidence of a biaxial nematic phase in an oxadiazole bent-core thermotropic liquid crystal C7. With an assortment of optical techniques such as polarizing optical microscopy, LC PolScope, and fluorescence confocal polarizing microscopy, we demonstrate that the secondary disclinations represent non-singular domain walls formed in an uniaxial nematic during the surface anchoring transition, in which surface orientation of the director changes from tangential (parallel to the bounding plates) to tilted. Each domain wall separates two regions with the director tilted in opposite azimuthal directions. At the centre of the wall, the director remains parallel to the bonding plates. The domain walls can be easily removed by applying a modest electric field. The anchoring transition is explained by the balance of (a) the intrinsic perpendicular surface anchoring produced by the polyimide aligning layer and (b) tangential alignment caused by ionic impurities forming electric double layers. The model is supported by the fact that the temperature of the tangential-tilted anchoring transition decreases as the cell thickness increases and as the concentration of ionic species (added salt) increases. We also demonstrate that the surface alignment is strongly affected by thermal degradation of the samples. The study shows that C7 exhibits only a uniaxial nematic phase and demonstrate yet another mechanism (formation of secondary disclinations) by which a uniaxial nematic can mimic a biaxial nematic behaviour.

  5. Power-law Behavior of Strings Scattered from Domain-wall at High Energies and Breakdown of their Linear Relations

    E-Print Network [OSTI]

    Chuan Tsung Chan; Jen-Chi Lee; Yi Yang

    2007-05-18

    In contrast to the common wisdom, we discover that, instead of the exponential fall-off of the form factors with Regge-pole structure, the high-energy scattering amplitudes of string scattered from Domain-wall behave as power-law with Regge-pole structure. This is to be compared with the well-known power-law form factors without Regge-pole structure of the D-instanton scatterings. This discovery makes Domain-wall scatterings an unique example of a hybrid of string and field theory scatterings. The calculation is done for bosonic string scatterings of arbitrary massive string states from D-24 brane. Moreover, we discover that the usual linear relations of high-energy string scattering amplitudes at each fixed mass level break down for the Domain-wall scatterings. This result gives a strong evidence that the existence of the infinite linear relations, or stringy symmetries, of high-energy string scattering amplitudes is responsible for the softer, exponential fall-off high-energy string scatterings than the power-law field theory scatterings.

  6. Metallic Magnetic Hetrostructures

    E-Print Network [OSTI]

    Leung, Chi Wah

    .2.2 Domains and magnetization processes 1.2.2.1 Domains and domain walls 1.2.2.2 Magnetization reversal and hysteresis 1.2.2.3 Modelling of magnetization process 1.3 Sputter deposition of thin films in this project 1.3.1 Substrate preparation 1.3.2 ‘UFO...

  7. The Static Approximation to B Meson Mixing using Light Domain-Wall Fermions: Perturbative Renormalization and Ground State Degeneracies

    E-Print Network [OSTI]

    Norman H. Christ; Thomas T. Dumitrescu; Taku Izubuchi; Oleg Loktik

    2007-10-28

    We discuss the theoretical input into the current RBC-UKQCD calculation of $f_{B_{d, s}}$ and $B_{B_{d, s}}$ using a smeared static heavy quark propagator, light domain-wall quarks and the Iwasaki gauge action. We present the complete one-loop, mean-field improved matching of heavy-light current and four-fermion lattice operators onto the static continuum theory renormalized in $\\bar{\\text{MS}}$(NDR). The large degeneracies present in a static calculation are addressed, and a method for extracting $f_B$ and $B_B$ using only box sources is described; implications for future calculations are discussed.

  8. Dynamics of skyrmions in chiral magnets: Dynamic phase transitions and equation of motion

    SciTech Connect (OSTI)

    Lin, Shi-Zeng, E-mail: szl@lanl.gov; Reichhardt, Charles; Batista, Cristian D.; Saxena, Avadh [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-05-07

    We study the dynamics of skyrmions in a metallic chiral magnet. First, we show that skyrmions can be created dynamically by destabilizing the ferromagnetic background state through a spin polarized current. We then treat skyrmions as rigid particles and derive the corresponding equation of motion. The dynamics of skyrmions is dominated by the Magnus force, which accounts for the weak pinning of skyrmions observed in experiments. Finally, we discuss the quantum motion of skyrmions.

  9. Domain Nucleation and Annihilation in Uniformly Magnetized State under Current Pulses in Narrow Ferromagnetic Wires

    E-Print Network [OSTI]

    Otani, Yoshichika

    of possible applications in hard disk drives, magnetic random access memory, and other spintronic devices.1 to nucleate a domain wall.10) This idea will be the use of the spintronic magnetization control. Experimental

  10. Domain-Wall Lattices in the Te-W(211) System 

    E-Print Network [OSTI]

    STOLZENBERG, M.; Lyuksyutov, Igor F.; BAUER, E.

    1990-01-01

    Knowledge of energy dissipation and relaxation in electron, spin, and lattice degrees of freedom is of fundamental importance from both a technological and scientific point of view. In this dissertation, the electronic and magnetization dynamics...

  11. Two-dimensional single-stream electron motion in a coaxial diode with magnetic insulation

    SciTech Connect (OSTI)

    Fuks, Mikhail I.; Schamiloglu, Edl [Department of Electrical and Computer Engineering, MSC01 1100, University of New Mexico, Albuquerque, New Mexico 87131-0001 (United States)] [Department of Electrical and Computer Engineering, MSC01 1100, University of New Mexico, Albuquerque, New Mexico 87131-0001 (United States)

    2014-05-15

    One of the most widespread models of electrons drifting around the cathode in magnetrons is the single-stream state, which is the Brillouin stream with purely azimuthal motion. We describe a single-stream state in which electrons not only move in the azimuthal direction, but also along the axial direction, which is useful for consideration, for example, of relativistic magnetrons, MILOs, and coaxial transmission lines. Relations are given for the conditions of magnetic insulation for 2D electron motion, for 1D azimuthal and axial motion, and for synchronism of these streams with the operating waves of M-type microwave sources. Relations are also provided for the threshold of generation in magnetrons with 2D electron motion.

  12. One-loop operator matching in the static heavy and domain-wall light quark system with O(a) improvement

    E-Print Network [OSTI]

    Tomomi Ishikawa; Yasumichi Aoki; Jonathan M. Flynn; Taku Izubuchi; Oleg Loktik

    2011-05-16

    We discuss perturbative O(g^2a) matching with static heavy quarks and domain-wall light quarks for lattice operators relevant to B-meson decays and $B^0$-$\\bar{B}^0$ mixing. The chiral symmetry of the light domain-wall quarks does not prohibit operator mixing at O(a) for these operators. The O(a) corrections to physical quantities are non-negligible and must be included to obtain high-precision simulation results for CKM physics. We provide results using plaquette, Symanzik, Iwasaki and DBW2 gluon actions and applying APE, HYP1 and HYP2 link-smearing for the static quark action.

  13. Non-perturbative renormalization of overlap quark bilinears on 2+1-flavor domain wall fermion configurations

    E-Print Network [OSTI]

    Zhaofeng Liu; Ying Chen; Shao-Jing Dong; Michael Glatzmaier; Ming Gong; Anyi Li; Keh-Fei Liu; Yi-Bo Yang; Jian-Bo Zhang

    2014-08-19

    We present renormalization constants of overlap quark bilinear operators on 2+1-flavor domain wall fermion configurations. This setup is being used by the chiQCD collaboration in calculations of physical quantities such as strangeness in the nucleon and the strange and charm quark masses. The scale independent renormalization constant for the axial vector current is computed using the Ward Identity. The renormalization constants for scalar, pseudoscalar and vector current are calculated in the RI-MOM scheme. Results in the MS-bar scheme are also given. The step scaling function of quark masses in the RI-MOM scheme is computed as well. The analysis uses, in total, six different ensembles of three sea quarks each on two lattices with sizes 24^3x64 and 32^3x64 at spacings a=(1.73 GeV)^{-1} and (2.28 GeV)^{-1}, respectively.

  14. Direct observation of domain walls in NiFe films using high-resolution Lorentz microscopy

    E-Print Network [OSTI]

    Laughlin, David E.

    . Wong and David E. Laughlin Department of Materials Science and Engineering, Carnegie Mellon University that the thickness dependence has a similar profile to the theoretically predicted trend but the actual wall with the interactive data language IDL image processing software so that the interference between magnetic

  15. SOLAR MAGNETIZED TORNADOES: ROTATIONAL MOTION IN A TORNADO-LIKE PROMINENCE

    SciTech Connect (OSTI)

    Su, Yang; Veronig, Astrid; Temmer, Manuela; Vanninathan, Kamalam; Gömöry, Peter; Wang, Tongjiang; Gan, Weiqun; Li, YouPing

    2014-04-10

    Su et al. proposed a new explanation for filament formation and eruption, where filament barbs are rotating magnetic structures driven by underlying vortices on the surface. Such structures have been noticed as tornado-like prominences when they appear above the limb. They may play a key role as the source of plasma and twist in filaments. However, no observations have successfully distinguished rotational motion of the magnetic structures in tornado-like prominences from other motions such as oscillation and counter-streaming plasma flows. Here we report evidence of rotational motions in a tornado-like prominence. The spectroscopic observations in two coronal lines were obtained from a specifically designed Hinode/EIS observing program. The data revealed the existence of both cold and million-degree-hot plasma in the prominence leg, supporting the so-called prominence-corona transition region. The opposite velocities at the two sides of the prominence and their persistent time evolution, together with the periodic motions evident in SDO/AIA dark structures, indicate a rotational motion of both cold and hot plasma with a speed of ?5 km s{sup –1}.

  16. Proper Motions of OH Masers and Magnetic Fields in Massive Star-Forming Regions

    E-Print Network [OSTI]

    Vincent L. Fish; Mark J. Reid

    2007-08-08

    We present data of proper motions of OH masers in the massive star-forming regions ON 1, K3-50, and W51 Main/South. OH maser motions in ON 1 are consistent with expansion at approximately 5 km/s, likely tracing the expanding ultracompact H II region. Motions in K3-50 are faster and may be indicating the final stages of OH maser emission in the source, before the OH masers turn off as the H II region transitions from the ultracompact to the compact phase. W51 South shows indications of aspherical expansion, while motions in W51 Main are more difficult to interpret. Nevertheless, it appears that the relative projected separation between W51 Main and W51 South is decreasing, corresponding to an estimate of enclosed mass of at least 1500 solar masses, consistent with estimates derived from millimeter-wavelength dust emission. We confirm the ~20 mG magnetic fields previously seen in W51 Main, which may represent the upper end of the density range allowable for 1665 MHz maser emission. Magnetic field strengths and directions, obtained from Zeeman splitting, in each source are consistent with values obtained in the first epoch four to nine years ago.

  17. Large Magnetic Fields and Motions of OH Masers in W75 N

    E-Print Network [OSTI]

    Vincent L. Fish; Mark J. Reid

    2006-11-02

    We report on a second epoch of VLBA observations of the 1665 and 1667 MHz OH masers in the massive star-forming region W75 N. We find evidence to confirm the existence of very strong (~40 mG) magnetic fields near source VLA 2. The masers near VLA 2 are dynamically distinct and include a very bright spot apparently moving at 50 km/s relative to those around VLA 1. This fast-moving spot may be an example of a rare class of OH masers seen in outflows in star-forming regions. Due to the variability of these masers and the rapidity of their motions, tracking these motions will require multiple observations over a significantly shorter time baseline than obtained here. Proper motions of the masers near VLA 1 are more suggestive of streaming along magnetized shocks rather than Keplerian rotation in a disk. The motions of the easternmost cluster of masers in W75 N (B) may be tracing slow expansion around an unseen exciting source.

  18. Nonlinear motion of coupled magnetic vortices in ferromagnetic/non-magnetic/ferromagnetic trilayer

    E-Print Network [OSTI]

    Jun, Su-Hyeong

    2010-01-01

    o f nanometer scale spintronic devices and memory devices [4]. In the realization o f spintronic and memory devices,potential application o f spintronics and magnetic storage

  19. Motion of free spins and NMR imaging without a radio-frequency magnetic field

    E-Print Network [OSTI]

    Kees van Schenk Brill; Jassem Lahfadi; Tarek Khalil; Daniel Grucker

    2015-04-19

    NMR imaging without any radio-frequency magnetic field is explained by a quantum treatment of independent spin~$\\tfrac 12$. The total magnetization is determined by means of their individual wave function. The theoretical treatment, based on fundamental axioms of quantum mechanics and solving explicitly the Schr\\"{o}dinger equation with the kinetic energy part which gives the motion of free spins, is recalled. It explains the phase shift of the spin noise spectrum with its amplitude compared to the conventional NMR spectrum. Moreover it explains also the relatively good signal to noise ratio of NMR images obtained without a RF pulse. This derivation should be helpful for new magnetic resonance imaging sequences or for developing quantum computing by NMR.

  20. Finite temperature QCD using 2+1 flavors of domain wall fermions at N{sub t}=8

    SciTech Connect (OSTI)

    Cheng, Michael; Christ, Norman H.; Li, Min; Mawhinney, Robert D.; Renfrew, Dwight; Hegde, Prasad; Karsch, Frithjof; Lin Meifeng; Vranas, Pavlos [Department of Physics, Columbia University, New York, New York 10027 (United States); Department of Physics and Astronomy, SUNY, Stony Brook, New York 11794-3800 (United States); Physics Department, Brookhaven National Laboratory, Upton, New York 11973, USA and Fakultaet fuer Physik, Universitaet Bielefeld, D-33615 Bielefeld (Germany); Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2010-03-01

    We study the region of the QCD phase transition using 2+1 flavors of domain wall fermions and a 16{sup 3}x8 lattice volume with a fifth dimension of L{sub s}=32. The disconnected light quark chiral susceptibility, quark number susceptibility, and the Polyakov loop suggest a chiral and deconfining crossover transition lying between 155 and 185 MeV for our choice of quark mass and lattice spacing. In this region the lattice scale deduced from the Sommer parameter r{sub 0} is a{sup -1{approx_equal}}1.3 GeV, the pion mass is {approx_equal}300 MeV, and the kaon mass is approximately physical. The peak in the chiral susceptibility implies a pseudocritical temperature T{sub c}=171(10)(17) MeV where the first error is associated with determining the peak location and the second with our unphysical light quark mass and nonzero lattice spacing. The effects of residual chiral symmetry breaking on the chiral condensate and disconnected chiral susceptibility are studied using several values of the valence L{sub s}.

  1. 3D Controlled Motion of a Microrobot using Magnetic Gradients Karim Belharet, David Folio and Antoine Ferreira

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    3D Controlled Motion of a Microrobot using Magnetic Gradients Karim Belharet, David Folio to allow 3D navigation of a microdevice in blood vessels, namely: (i) vessel path extraction, (ii) magnetic locations in the human body become accessible. Because the method of propulsion should al- low

  2. Note: Spectral motional Stark effect diagnostic for measurement of magnetic fields below 0.3 T

    SciTech Connect (OSTI)

    Lizunov, A.; Donin, A. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation) [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Savkin, V. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation)] [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation)

    2013-08-15

    The paper reports on development of the spectral motional Stark effect (MSE) diagnostic in the midplane of the gas dynamic trap (GDT) linear system for magnetic confinement of anisotropic hot-ion plasma. The axially symmetric GDT vacuum magnetic field has a minimum value in the midplane, which varies from 0.2 to 0.35 T in different regimes of operation. Buildup of 15 keV ion population generates a diamagnetic reduction of magnetic field in the plasma core of up to 30% in the maximum density region, as measured by the existing eight-line MSE diagnostic. Commissioning of the midplane MSE provided first direct measurements of diamagnetic modifications in the minimum magnetic field GDT section, a necessary complement to the understanding of equilibrium and self-organization of high-? plasmas in GDT. Making use of the stable short-pulse diagnostic beam and calibration of the apparent spectral width of beam emission lines allow for the measurement of the plasma magnetic field of 0.29 ± 0.007 T with the integration time of 200 ?s.

  3. Neutral $B$ meson mixings and $B$ meson decay constants with static heavy and domain-wall light quarks

    E-Print Network [OSTI]

    Yasumichi Aoki; Tomomi Ishikawa; Taku Izubuchi; Christoph Lehner; Amarjit Soni

    2015-06-29

    Neutral $B$ meson mixing matrix elements and $B$ meson decay constants are calculated. Static approximation is used for $b$ quark and domain-wall fermion formalism is employed for light quarks. The calculations are carried out on $2+1$ flavor dynamical ensembles generated by RBC/UKQCD Collaborations with lattice spacings $0.086$fm ($a^{-1}\\sim 2.3$GeV) and $0.11$fm ($1.7$GeV), and a fixed physical spatial volume of about $(2.7{\\rm fm})^3$. In the static quark action, link-smearings are used to improve the signal-to-noise ratio. We employ two kinds of link-smearings, HYP1 and HYP2, and their results are combined in taking the continuum limit. For the matching between the lattice and the continuum theory, one-loop perturbative $O(a)$ improvements are made to reduce discretization errors. As the most important quantity of this work, we obtain SU(3) breaking ratio $\\xi=1.208(60)$, where the error includes statistical and systematic one. (Uncertainty from infinite $b$ quark mass is not included.) We also find other neutral $B$ meson mixing quantities $f_B\\sqrt{\\hat{B}_B}=240(22)$MeV, $f_{B_s}\\sqrt{\\hat{B}_{B_s}}=290(22)$MeV, $\\hat{B}_B=1.17(22)$, $\\hat{B}_{B_s}=1.22(13)$ and $B_{B_s}/B_B=1.028(74)$, $B$ meson decay constants $f_B=219(17)$MeV, $f_{B_s}=264(19)$MeV and $f_{B_s}/f_B=1.193(41)$, in the static limit of $b$ quark, which do not include infinite $b$ quark mass uncertainty.

  4. Neutral B-meson mixing from unquenched lattice QCD with domain-wall light quarks and static b-quarks

    E-Print Network [OSTI]

    Conrado Albertus; Yasumichi Aoki; Peter A. Boyle; Norman H. Christ; Thomas T. Dumitrescu; Jonathan M. Flynn; Tomomi Ishikawa; Taku Izubuchi; Oleg Loktik; Christopher T. Sachrajda; Amarjit Soni; Ruth S. Van de Water; Jan Wennekers; Oliver Witzel

    2010-01-12

    We demonstrate a method for calculating the neutral B-meson decay constants and mixing matrix elements in unquenched lattice QCD with domain-wall light quarks and static b-quarks. Our computation is performed on the "2+1" flavor gauge configurations generated by the RBC and UKQCD Collaborations with a lattice spacing of a approx 0.11 fm (a^-1 = 1.729 GeV) and a lattice spatial volume of approximately (1.8 fm)^3. We simulate at three different light sea quark masses with pion masses down to approximately 430 MeV, and extrapolate to the physical quark masses using a phenomenologically-motivated fit function based on next-to-leading order heavy-light meson SU(2) chiral perturbation theory. For the b-quarks, we use an improved formulation of the Eichten-Hill action with static link-smearing to increase the signal-to-noise ratio. We also improve the heavy-light axial current used to compute the B-meson decay constant to O(alpha_s p a) using one-loop lattice perturbation theory. We present initial results for the SU(3)-breaking ratios f_{B_s}/f_{B_d} and xi = f_{B_s} sqrt{B_{B_s}}/f_{B_d} sqrt{B_{B_d}}, thereby demonstrating the viability of the method. For the ratio of decay constants, we find f_{B_s}/f_{B_d} = 1.15(12) and for the ratio of mixing matrix elements, we find xi = 1.13(12), where in both cases the errors reflect the combined statistical and systematic uncertainties, including an estimate of the size of neglected O(1/m_b) effects.

  5. Quasi-harmonic oscillatory motion of charged particles around a Schwarzschild black hole immersed in an uniform magnetic field

    E-Print Network [OSTI]

    Martin Kološ; Zden?k Stuchlík; Arman Tursunov

    2015-06-22

    In order to test the role of large-scale magnetic fields in quasiperiodic oscillation phenomena observed in microquasars, we study oscillatory motion of charged particles in vicinity of a Schwarzschild black hole immersed into an external asymptotically uniform magnetic field. We determine the fundamental frequencies of small harmonic oscillations of charged test particles around stable circular orbits in the equatorial plane of a magnetized black hole, and discuss the radial profiles of frequencies of the radial and latitudinal harmonic oscillations in dependence on the mass of the black hole and the strength of the magnetic field. We demonstrate that assuming relevance of resonant phenomena of the radial and latitudinal oscillations of charged particles at their frequency ratio $3:2$, the oscillatory frequencies of charged particles can be well related to the frequencies of the twin high-frequency quasi-periodic oscillations observed in the microquasars GRS 1915+105, XTE 1550-564 and GRO 1655-40.

  6. Quasi-harmonic oscillatory motion of charged particles around a Schwarzschild black hole immersed in an uniform magnetic field

    E-Print Network [OSTI]

    Kološ, Martin; Tursunov, Arman

    2015-01-01

    In order to test the role of large-scale magnetic fields in quasiperiodic oscillation phenomena observed in microquasars, we study oscillatory motion of charged particles in vicinity of a Schwarzschild black hole immersed into an external asymptotically uniform magnetic field. We determine the fundamental frequencies of small harmonic oscillations of charged test particles around stable circular orbits in the equatorial plane of a magnetized black hole, and discuss the radial profiles of frequencies of the radial and latitudinal harmonic oscillations in dependence on the mass of the black hole and the strength of the magnetic field. We demonstrate that assuming relevance of resonant phenomena of the radial and latitudinal oscillations of charged particles at their frequency ratio $3:2$, the oscillatory frequencies of charged particles can be well related to the frequencies of the twin high-frequency quasi-periodic oscillations observed in the microquasars GRS 1915+105, XTE 1550-564 and GRO 1655-40.

  7. Temperature dependent nucleation, propagation, and annihilation of domain walls in all-perpendicular spin-valve nanopillars

    SciTech Connect (OSTI)

    Gopman, D. B. Kent, A. D.; Bedau, D.; Mangin, S.; Fullerton, E. E.; Katine, J. A.

    2014-03-21

    We present a study of the temperature dependence of the switching fields in Co/Ni-based perpendicularly magnetized spin-valves. While magnetization reversal of all-perpendicular Co/Ni spin valves at ambient temperatures is typically marked by a single sharp step change in resistance, low temperature measurements can reveal a series of resistance steps, consistent with non-uniform magnetization configurations. We propose a model that consists of domain nucleation, propagation, and annihilation to explain the temperature dependence of the switching fields. Interestingly, low temperature (<30?K) step changes in resistance that we associate with domain nucleation have a bimodal switching field and resistance step distribution, attributable to two competing nucleation pathways.

  8. The Low Energy Constants of $SU(2)$ Partially Quenched Chiral Perturbation Theory from $N_{f}=2+1$ Domain Wall QCD

    E-Print Network [OSTI]

    Boyle, P A; Garron, N; Jung, C; Jüttner, A; Kelly, C; Mawhinney, R D; McGlynn, G; Murphy, D J; Ohta, S; Portelli, A; Sachrajda, C T

    2015-01-01

    We have performed fits of the pseudoscalar masses and decay constants, from a variety of RBC-UKQCD domain wall fermion ensembles, to $SU(2)$ partially quenched chiral perturbation theory at next-to leading order (NLO) and next-to-next-to leading order (NNLO). We report values for 9 NLO and 8 linearly independent combinations of NNLO partially quenched low energy constants, which we compare to other lattice and phenomenological determinations. We discuss the size of successive terms in the chiral expansion and use our large set of low energy constants to make predictions for mass splittings due to QCD isospin breaking effects and the S-wave $\\pi \\pi$ scattering lengths. We conclude that, for the range of pseudoscalar masses explored in this work, $115~\\mathrm{MeV} \\lesssim m_{\\rm PS} \\lesssim 430~\\mathrm{MeV}$, the NNLO $SU(2)$ expansion is quite robust and can fit lattice data with percent-scale accuracy.

  9. B-meson decay constants from 2+1-flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks

    E-Print Network [OSTI]

    Norman H. Christ; Jonathan M. Flynn; Taku Izubuchi; Taichi Kawanai; Christoph Lehner; Amarjit Soni; Ruth S. Van de Water; Oliver Witzel

    2015-02-02

    We calculate the B-meson decay constants f_B, f_Bs, and their ratio in unquenched lattice QCD using domain-wall light quarks and relativistic b-quarks. We use gauge-field ensembles generated by the RBC and UKQCD collaborations using the domain-wall fermion action and Iwasaki gauge action with three flavors of light dynamical quarks. We analyze data at two lattice spacings of a ~ 0.11, 0.086 fm with unitary pion masses as light as M_pi ~ 290 MeV; this enables us to control the extrapolation to the physical light-quark masses and continuum. For the b-quarks we use the anisotropic clover action with the relativistic heavy-quark interpretation, such that discretization errors from the heavy-quark action are of the same size as from the light-quark sector. We renormalize the lattice heavy-light axial-vector current using a mostly nonperturbative method in which we compute the bulk of the matching factor nonperturbatively, with a small correction, that is close to unity, in lattice perturbation theory. We also improve the lattice heavy-light current through O(alpha_s a). We extrapolate our results to the physical light-quark masses and continuum using SU(2) heavy-meson chiral perturbation theory, and provide a complete systematic error budget. We obtain f_B0 = 199.5(12.6) MeV, f_B+ = 195.6(14.9) MeV, f_Bs = 235.4(12.2) MeV, f_Bs/f_B0 = 1.197(50), and f_Bs/f_B+ = 1.223(71), where the errors are statistical and total systematic added in quadrature. These results are in good agreement with other published results and provide an important independent cross check of other three-flavor determinations of $B$-meson decay constants using staggered light quarks.

  10. Vacuum Arc Plasma Motion In A Curvilinear Magnetic Field In A Framework Of The Rigid-Rotor Model

    SciTech Connect (OSTI)

    Timoshenko, Aleksandr I.; Gnybida, Mikhail V.; Taran, Valeriy S.; Tereshin, Vladimir I.; Chechel'nitskij, Oleg G.

    2006-01-15

    Vacuum-arc plasma motion in a toroidal magnetic field is described on a base of steady-state ({partial_derivative}/{partial_derivative}t = 0) Vlasov-Maxwell equations for the long plasma column aligned parallel to a constant axial magnetic field. The relations for the self-consistent electric field, which appears due to a displacement of the electrons from the ions at the curvilinear trajectory, were derived within a framework of the drift approximation. The dynamics of the central part of the plasma flow in the electric polarization fields was considered in detail. The displacement of the plasma flow at the output of the plasma duct was calculated. The results are in a good agreement with the experimental data obtained by others authors.

  11. Effect of substrate temperature on the magnetic properties of epitaxial sputter-grown Co/Pt

    SciTech Connect (OSTI)

    Mihai, A. P.; Whiteside, A. L.; Canwell, E. J.; Marrows, C. H.; Moore, T. A.; Benitez, M. J.; McGrouther, D.; McVitie, S.; McFadzean, S.

    2013-12-23

    Epitaxial Co/Pt films have been deposited by dc-magnetron sputtering onto heated C-plane sapphire substrates. X-ray diffraction, the residual resistivity, and transmission electron microscopy indicate that the Co/Pt films are highly ordered on the atomic scale. The coercive field and the perpendicular magnetic anisotropy increase as the substrate temperature is increased from 100–250?°C during deposition of the Co/Pt. Measurement of the domain wall creep velocity as a function of applied magnetic field yields the domain wall pinning energy, which scales with the coercive field. Evidence for an enhanced creep velocity in highly ordered epitaxial Co/Pt is found.

  12. Effects of demagnetizing factors on transient motion of ferrofluid in a uniform rotating magnetic field

    E-Print Network [OSTI]

    Snively, Michael John

    2011-01-01

    The mechanisms that lead to bulk flow within a ferrofluid-filled container subjected to a rotating uniform magnetic field are experimentally studied. There are two prevailing theories: spin diffusion theory and flow due ...

  13. Motion-Tolerant Magnetic Earring Sensor and Wireless Earpiece for Wearable Photoplethysmography

    E-Print Network [OSTI]

    Poh, Ming-Zher

    This paper addresses the design considerations and critical evaluation of a novel embodiment for wearable photoplethysmography (PPG) comprising a magnetic earring sensor and wireless earpiece. The miniaturized sensor can ...

  14. Solution for "geodesic" motion of a Schwarzschild black hole along a magnetic field in AdS2 x S2 space-time

    E-Print Network [OSTI]

    Alekseev, George A

    2015-01-01

    The exact solution of Einstein - Maxwell equations for a Schwarzschild black hole immersed in the static spatially homogeneous AdS${}^2\\times\\mathbb{S}^2$ space-time of Bertotti-Robinson magnetic universe is presented. In this solution, the black hole possesses a finite initial boost in the direction of the magnetic field and performs a "geodesic" oscillating motion interacting with the background gravitational and electromagnetic fields.

  15. Results of stretched wire field integral measurements on the mini-undulator magnet -- comparison of results obtained from circular and translational motion of the integrating wire

    SciTech Connect (OSTI)

    Solomon, L.

    1998-05-01

    Measurements of the multipole content of the Mini-Undulator magnet have been made with two different integrating wire techniques. Both measurements used 43 strand Litz wire stretched along the length of the magnet within the magnet gap. In the first technique, the wire motion was purely translational, while in the second technique the wire was moved along a circular path. The induced voltage in the Litz wire was input into a Walker integrator, and the integrator output was analyzed as a function of wire position for determination of the multipole content of the magnetic field. The mini-undulator magnet is a 10 period, 80 mm per period hybrid insertion device. For all the data contained herein the magnet gap was set at 49 mm. In the mini-undulator magnet, the iron poles are 18mm x 32mm x 86 mm, and the Samarium Cobalt permanent magnet blocks are 22mm x 21mm x 110mm. For this magnet, which is a shortened prototype for the NSLS Soft X-Ray Undulator Magnet, the undulator parameter K = 0.934 B (Tesla){lambda}(cm), and B(tesla) = 0.534/sinh({pi}Gap/{lambda}). At a gap of 49 mm, the magnetic field is 1590 Gauss.

  16. Spin-Orbit Torque Driven Magnetization Dynamics in (Ga,Mn)As and (Ga,Mn)(As,P) Dilute Magnetic Semiconductors 

    E-Print Network [OSTI]

    Vehstedt, Erin Kathleen

    2014-07-18

    . In order to overcome these limits, new methods must be developed to reliably transmit and store data more efficiently. The understanding and manipulation of magnetic domain walls (DWs) may play a pivotal role in the development of new non-volatile and down...

  17. Reversal mechanisms of coupled bi-component magnetic nanostructures G. Shimon,1,2

    E-Print Network [OSTI]

    Adeyeye, Adekunle

    in applications such as high density information storage,1­3 domain wall (DW) logic,4,5 and memory devices.6Reversal mechanisms of coupled bi-component magnetic nanostructures G. Shimon,1,2 A. O. Adeyeye,1 Institute of Physics. [http://dx.doi.org/10.1063/1.4747446] Thin film ferromagnetic nanostructures have been

  18. Interaction of mesoscopic magnetic textures with superconductors 

    E-Print Network [OSTI]

    Erdin, S.; Kayali, AF; Lyuksyutov, Igor F.; Pokrovsky, Valery L.

    2002-01-01

    magnetizatio Th , numbe PHYSICAL REVIEW B 66, 014414 ~2002! proposed and analyzed. Such systems include arrays of mag- netic dots on the top of a SC film,6?8 FM-SC bilayers,9?11 magnetic nanorods embedded into a superconductor,12 mag- netic stripes... in superconducting films,13 a layer of magnetic dipoles between two bulk superconductors,14 an array of magnetic dipoles mimicking the FM dots on SC film,15 and a domain wall in a thick magnetic film on the bulk super- conductor.16,18 Earlier Marmorkos et al.17...

  19. RESULTS OF STRETCHED WIRE FIELD INTEGRAL MEASUREMENTS ON THE MINI-UNDULATOR MAGNET-COMPARISON OF RESULTS OBTAINED FROM CIRCULAR AND TRANSLATIONAL MOTION OF THE INTEGRATING WIRE.

    SciTech Connect (OSTI)

    SOLOMON, L.

    1998-05-01

    Measurements of the multipole content of the Mini-Undulator magnet have been made with two different integrating wire techniques. Both measurements used 43 strand Litz wire stretched along the length of the magnet within the magnet gap. In the first technique, the wire motion was purely translational, while in the second technique the wire was moved along a circular path. The induced voltage in the Litz wire was input into a Walker integrator, and the integrator output was analyzed as a function of wire position for determination of the multipole content of the magnetic field. The mini-undulator magnet is a 10 period, 80 mm per period hybrid insertion device. For all the data contained herein the magnet gap was set at 49 mm. In the mini-undulator magnet, the iron poles are 18mm x 32mm x 86mm, and the Samarium Cobalt permanent magnet blocks are 22mm x 21mm x 110mm. For this magnet, which is a shortened prototype for the NSLS Soft X-Ray Undulator Magnet, the undulator parameter K = 0.934 B(Tesla){lambda}(cm), and B(tesla) = 0.534/sinh({pi}Gap/{lambda}). At a gap of 49 mm, the magnetic field is 1590 Gauss. The 43 strand Litz wire is supported on motorized x-y stages at both ends of the magnet, which are controlled by stepping motors through a Labview program. One leg of the wire loop is within the magnet gap, and the other leg is in an essentially field free region. Only the leg of the wire loop within the magnet gap is moved during data acquisition. The Litz wire is tensioned with 11.5 pounds, and is wrapped with a supporting tape which is itself tensioned with 18 pounds through a spring and turnbuckle arrangement. With this setup the sag in the wire over the 72 inch span is less than 0.003 inches, as measured with survey instruments. Photographs of the setup are shown.

  20. 3An electron of charge | | and mass moves in the presence of a uniform magnetic field pointing in the z-direction . The motion of the electron is confined to the -plane.

    E-Print Network [OSTI]

    Ha, Taekjip

    A-7 3An electron of charge | | and mass moves in the presence of a uniform magnetic field pointing in the z-direction . The motion of the electron is confined to the - plane. (a) As a warm up, write down by [ ] where is the canonical momentum, and is the magnetic vector potential. (c) The Hamiltonian

  1. Construction of a two-parameter empirical model of left ventricle wall motion using cardiac tagged magnetic resonance imaging data

    E-Print Network [OSTI]

    Shi, Jack J; Alenezy, Mohammed D.; Smirnova, Irina V.; Bilgen, Mehmet

    2012-10-24

    /Tcardiac=0.4, but read 0.2 for the apex and - 0.08 for the base level. The difference indicated that the apex twisted more than the base. Conclusion It is feasible to empirically model the spatial and temporal evolution of the LV wall motion using a two...

  2. Development of the B-Stark motional Stark effect diagnostic for measurements of the internal magnetic field in the DIII-D tokamak

    E-Print Network [OSTI]

    Pablant, Novimir Antoniuk

    2010-01-01

    1.1 Magnetic confinement fusion . . . . . . . . . . 1.2Stokes vector magnetic confinement fusion, 1 magnetic fieldare discussed. Magnetic confinement fusion The goal of

  3. Magnetic Fields above the Surface of aSuperconductor with Internal Magnetism

    SciTech Connect (OSTI)

    Bluhm, Hendrik; /Stanford U., Phys. Dept. /SLAC, SSRl

    2007-06-26

    The author presents a method for calculating the magnetic fields near a planar surface of a superconductor with a given intrinsic magnetization in the London limit. He computes solutions for various magnetic domain boundary configurations and derives relations between the spectral densities of the magnetization and the resulting field in the vacuum half space, which are useful if the magnetization can be considered as a statistical quantity and its features are too small to be resolved individually. The results are useful for analyzing and designing magnetic scanning experiments. Application to existing data from such experiments on Sr{sub 2}RuO{sub 4} show that a domain wall would have been detectable, but the magnetic field of randomly oriented small domains and small defects may have been smaller than the experimental noise level.

  4. Fast chirality reversal of the magnetic vortex by electric current

    SciTech Connect (OSTI)

    Lim, W. L. Liu, R. H.; Urazhdin, S.; Tyliszczak, T.; Erokhin, S. G.; Berkov, D.

    2014-12-01

    The possibility of high-density information encoding in magnetic materials by topologically stable inhomogeneous magnetization configurations such as domain walls, skyrmions, and vortices has motivated intense research into mechanisms enabling their control and detection. While the uniform magnetization states can be efficiently controlled by electric current using magnetic multilayer structures, this approach has proven much more difficult to implement for inhomogeneous states. Here, we report direct observation of fast reversal of magnetic vortex by electric current in a simple planar structure based on a bilayer of spin Hall material Pt with a single microscopic ferromagnetic disk contacted by asymmetric electrodes. The reversal is enabled by a combination of the chiral Oersted field and spin current generated by the nonuniform current distribution in Pt. Our results provide a route for the efficient control of inhomogeneous magnetization configurations by electric current.

  5. Magnetization reversal assisted by half antivortex states in nanostructured circular cobalt disks

    SciTech Connect (OSTI)

    Lara, A.; Aliev, F. G.; Dobrovolskiy, O. V.; Prieto, J. L.; Huth, M.

    2014-11-03

    The half antivortex, a fundamental topological structure which determines magnetization reversal of submicron magnetic devices with domain walls, has been suggested also to play a crucial role in spin torque induced vortex core reversal in circular disks. Here, we report on magnetization reversal in circular disks with nanoholes through consecutive metastable states with half antivortices. In-plane anisotropic magnetoresistance and broadband susceptibility measurements accompanied by micromagnetic simulations reveal that cobalt (Co) disks with two and three linearly arranged nanoholes directed at 45° and 135° with respect to the external magnetic field show reproducible step-like changes in the anisotropic magnetoresistance and magnetic permeability due to transitions between different intermediate states mediated by vortices and half antivortices confined to the dot nanoholes and edges, respectively. Our findings are relevant for the development of multi-hole based spintronic and magnetic memory devices.

  6. ElectroMechanical Systems A transducer used to measure translational motion is shown in Figure 1.1. The permanent magnet

    E-Print Network [OSTI]

    Landers, Robert G.

    Electro­Mechanical Systems QUESTION 1 A transducer used to measure translational motion is shown variables and inputs. #12;Electro­Mechanical Systems 2 L R ei(t) + - M K B N S I(t) Figure 2.1 QUESTION 3 of state equations describing the system dynamics. d. Determine the state variables and inputs. #12;Electro­Mechanical

  7. Motion-reversal in a simple microscopic swimmer

    E-Print Network [OSTI]

    A. Alexander-Katz

    2007-05-18

    We study the motion of a microscopic swimmer composed of a semiflexible polymer anchored at the surface of a magnetic sphere using hydrodynamic simulations and scaling arguments. The swimmer is driven by a rotating magnetic field, and displays forward and backward motion depending on the value of the rotational frequency. In particular, the system exhibits forward thrust for frequencies below a critical frequency $\\omega^*$, while above $\\omega^*$ the motion is reversed.

  8. On new maximal supergravity and its BPS domain-walls

    E-Print Network [OSTI]

    Adolfo Guarino

    2015-03-20

    We revise the SU(3)-invariant sector of $\\mathcal{N}=8$ supergravity with dyonic SO(8) gaugings. By using the embedding tensor formalism, analytic expressions for the scalar potential, superpotential(s) and fermion mass terms are obtained as a function of the electromagnetic phase $\\omega$ and the scalars in the theory. Equipped with these results, we explore non-supersymmetric AdS critical points at $\\omega \

  9. The static quark potential for dynamical domain wall fermion simulations

    E-Print Network [OSTI]

    Min Li

    2006-10-18

    We present preliminary results for the static quark potential computed on some of the DWF lattice configurations generated by the RBC-UKQCD collaborations. Most of these results were obtained using Wilson lines joining spatial planes fixed into the Coulomb gauge. We compare the results from this method with the earlier ones on $16^3 \\times 32$ lattices using Bresenham spatial paths with APE smeared link variables. Some preliminary results on $24^3 \\times 64$ lattices are also presented.

  10. Nucleon transverse momentum-dependent parton distributions from domain wall

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTech Connect Nanomechanical switchFlue Gas StreamsConnectArticle) | SciTechfermion

  11. Nucleon transverse momentum-dependent parton distributions from domain wall

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTech Connect Nanomechanical switchFlue Gas StreamsConnectArticle) |

  12. Iran Thomas Auditorium, 8600 Charged Domain Walls in Ferroelectrics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACT EVALUATIONIntroducing the RichardBudgetIowaOctober 5,December 10,

  13. Perceiving Motion and Events Image motion vs. Object Motion

    E-Print Network [OSTI]

    Majumder, Aditi

    ? But can we always "see" it moving? ­ What about the moon... ­ Or the blades of a helicopter? #12;10 What;14 Apparent Motion If video is just a sequence of frames, why do we see motion? First Tested by Sigmund

  14. Magnetic spectroscopy and microscopy of functional materials

    SciTech Connect (OSTI)

    Jenkins, C.A.

    2011-01-28

    Heusler intermetallics Mn{sub 2}Y Ga and X{sub 2}MnGa (X; Y =Fe, Co, Ni) undergo tetragonal magnetostructural transitions that can result in half metallicity, magnetic shape memory, or the magnetocaloric effect. Understanding the magnetism and magnetic behavior in functional materials is often the most direct route to being able to optimize current materials for todays applications and to design novel ones for tomorrow. Synchrotron soft x-ray magnetic spectromicroscopy techniques are well suited to explore the the competing effects from the magnetization and the lattice parameters in these materials as they provide detailed element-, valence-, and site-specifc information on the coupling of crystallographic ordering and electronic structure as well as external parameters like temperature and pressure on the bonding and exchange. Fundamental work preparing the model systems of spintronic, multiferroic, and energy-related compositions is presented for context. The methodology of synchrotron spectroscopy is presented and applied to not only magnetic characterization but also of developing a systematic screening method for future examples of materials exhibiting any of the above effects. The chapter progression is as follows: an introduction to the concepts and materials under consideration (Chapter 1); an overview of sample preparation techniques and results, and the kinds of characterization methods employed (Chapter 2); spectro- and microscopic explorations of X{sub 2}MnGa/Ge (Chapter 3); spectroscopic investigations of the composition series Mn{sub 2}Y Ga to the logical Mn{sub 3}Ga endpoint (Chapter 4); and a summary and overview of upcoming work (Chapter 5). Appendices include the results of a Think Tank for the Graduate School of Excellence MAINZ (Appendix A) and details of an imaging project now in progress on magnetic reversal and domain wall observation in the classical Heusler material Co{sub 2}FeSi (Appendix B).

  15. Magneto-optical imaging of thin magnetic films using spins in diamond

    E-Print Network [OSTI]

    David A. Simpson; Jean-Philippe Tetienne; Julia McCoey; Kumaravelu Ganesan; Liam T. Hall; Steven Petrou; Robert E. Scholten; Lloyd C. L. Hollenberg

    2015-08-10

    Imaging the fields of magnetic materials provides crucial insight into the physical and chemical processes surrounding magnetism, and has been a key ingredient in the spectacular development of magnetic data storage. Existing approaches using the magneto-optic Kerr effect (MOKE), x-ray and electron microscopy have limitations that constrain further development, and there is increasing demand for imaging and characterisation of magnetic phenomena in real time with high spatial resolution. In this work, we show how the magneto-optical response of an array of negatively-charged nitrogen-vacancy spins in diamond can be used to image and map the sub-micron stray magnetic field patterns from thin ferromagnetic films. Using optically detected magnetic resonance, we demonstrate wide-field magnetic imaging over 100x100 {\\mu}m^2 with a diffraction-limited spatial resolution of 440 nm at video frame rates, under ambient conditions. We demonstrate a novel all-optical spin relaxation contrast imaging approach which can image magnetic structures in the absence of an applied microwave field. Straightforward extensions promise imaging with sub-{\\mu}T sensitivity and sub-optical spatial and millisecond temporal resolution. This work establishes practical diamond-based wide-field microscopy for rapid high-sensitivity characterisation and imaging of magnetic samples, with the capability for investigating magnetic phenomena such as domain wall and skyrmion dynamics and the spin Hall effect in metals.

  16. Motional Spin Relaxation in Large Electric Fields

    E-Print Network [OSTI]

    Riccardo Schmid; B. Plaster; B. W. Filippone

    2008-07-02

    We discuss the precession of spin-polarized Ultra Cold Neutrons (UCN) and $^{3}$He atoms in uniform and static magnetic and electric fields and calculate the spin relaxation effects from motional $v\\times E$ magnetic fields. Particle motion in an electric field creates a motional $v\\times E$ magnetic field, which when combined with collisions, produces variations of the total magnetic field and results in spin relaxation of neutron and $^{3}$He samples. The spin relaxation times $T_{1}$ (longitudinal) and $T_{2}$ (transverse) of spin-polarized UCN and $^{3}$He atoms are important considerations in a new search for the neutron Electric Dipole Moment at the SNS \\emph{nEDM} experiment. We use a Monte Carlo approach to simulate the relaxation of spins due to the motional $v\\times E$ field for UCN and for $^{3}$He atoms at temperatures below $600,\\mathrm{mK}$. We find the relaxation times for the neutron due to the $v\\times E$ effect to be long compared to the neutron lifetime, while the $^{3}$He relaxation times may be important for the \\emph{nEDM} experiment.

  17. GLOBAL PLATE MOTION FRAMES: TOWARD A UNIFIED MODEL

    E-Print Network [OSTI]

    Torsvik, Trond Helge

    to a reference system such as the Earth's mantle, are still poorly understood. Accurate absolute plate motion magnetic dipole axis are not necessarily fixed to the mantle reference system. Absolute plate motion models and a paleomagnetic absolute plate reference system into a ``hybrid'' model for the time period from the assembly

  18. Motion characteristics of long ac arcs in atmospheric air

    SciTech Connect (OSTI)

    Gu Shanqiang; He Jinliang; Zeng Rong; Zhang Bo; Xu Guozheng; Chen Weijiang

    2007-01-29

    Experiments on the motion of long alternating current arcs in atmospheric air show that the anode and cathode arc roots have different motion characteristics because of different formation mechanisms. During a half cycle of the arc current, the anode arc root moves towards the direction of magnetic force and occasionally has a jumping motion, while the cathode arc root moves sufficiently slow to consider it stationary and hardly has any jump. The arc column has a complex shape and moves under the drive of the magnetic force and is also quickened by the lower arc root.

  19. Motion in Quantum Gravity

    E-Print Network [OSTI]

    Karim Noui

    2010-03-31

    We tackle the question of motion in Quantum Gravity: what does motion mean at the Planck scale? Although we are still far from a complete answer we consider here a toy model in which the problem can be formulated and resolved precisely. The setting of the toy model is three dimensional Euclidean gravity. Before studying the model in detail, we argue that Loop Quantum Gravity may provide a very useful approach when discussing the question of motion in Quantum Gravity.

  20. Hamiltonian theory of adiabatic motion of relativistic charged particles

    SciTech Connect (OSTI)

    Tao Xin; Chan, Anthony A.; Brizard, Alain J. [Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States); Department of Chemistry and Physics, Saint Michael's College, Colchester, Vermont 05439 (United States)

    2007-09-15

    A general Hamiltonian theory for the adiabatic motion of relativistic charged particles confined by slowly varying background electromagnetic fields is presented based on a unified Lie-transform perturbation analysis in extended phase space (which includes energy and time as independent coordinates) for all three adiabatic invariants. First, the guiding-center equations of motion for a relativistic particle are derived from the particle Lagrangian. Covariant aspects of the resulting relativistic guiding-center equations of motion are discussed and contrasted with previous works. Next, the second and third invariants for the bounce motion and drift motion, respectively, are obtained by successively removing the bounce phase and the drift phase from the guiding-center Lagrangian. First-order corrections to the second and third adiabatic invariants for a relativistic particle are derived. These results simplify and generalize previous works to all three adiabatic motions of relativistic magnetically trapped particles.

  1. BROWNIAN MOTION JUSTIN HARTMANN

    E-Print Network [OSTI]

    May, J. Peter

    BROWNIAN MOTION JUSTIN HARTMANN Abstract. This paper begins to explore a rigorous introduction: August 24, 2009. 1 #12;2 JUSTIN HARTMANN Definition 1.3. If S is a topological space, then the sigma

  2. Ternary superlattice boosting interface-stabilized magnetic chirality

    SciTech Connect (OSTI)

    Chen, Gong; Schmid, Andreas K.; N'Diaye, Alpha T.; Wu, Yizheng

    2015-02-09

    In cobalt-nickel multilayers grown on iridium surfaces, magnetic homo-chirality can be stabilized by Dzyaloshinskii-Moriya interactions (DMI) at the interface with the substrate. When thickness of the multilayers is increased beyond threshold values, then non-chiral bulk properties exceed interface contributions and this type of chirality vanishes. Here, we use spin-polarized low energy electron microscopy to measure these thickness thresholds, and we determine estimates of the strength of the DMI from the measurements. Even though the same 5d heavy metal is used as a substrate, a remarkably large variation is found between the two 3d magnets: our results indicate that the strength of the DMI at Co/Ir interfaces is three times larger than at Ni/Ir interfaces. We show how this finding provides ways to extend interfacial-DMI stabilization of domain wall chirality to 3d/5d/3d ternary multilayers such as [Ni/Ir/Co]{sub n}. Such strategies may extend chirality-control to larger film thickness and a wider range of substrates, which may be useful for designing new spintronics devices.

  3. Turbulence, Transport and the Density Limit in Magnetic Fusion Experiments

    E-Print Network [OSTI]

    Greenwald, Martin

    Program) 3 Magnetic Confinement Takes advantage of the motion of charged particles in a magnetic field) · In toroidal devices, plasma is confined by Poloidal magnetic fields #12;DESPITE THE CHALLENGES, PROGRESS HAS AND MAGNETIC CONFINEMENT· · · · THE DENSITY LIMIT PROBLEM INTERLUDE ON TRANSPORT AND TURBULENCE TOWARDS

  4. Turbulence and Transport The Secrets of Magnetic Confinement

    E-Print Network [OSTI]

    Greenwald, Martin

    Magnetic Confinement · Takes advantage of the motion of charged particles in a magnetic field. HOW DO WE DO. · In Toroidal devices, plasma is confined by Poloidal magnetic fields #12;\\COLLISIONAL TRANSPORT ITurbulence and Transport The Secrets of Magnetic Confinement Presented by Martin Greenwald MIT

  5. Motion detector and analyzer

    DOE Patents [OSTI]

    Unruh, W.P.

    1987-03-23

    Method and apparatus are provided for deriving positive and negative Doppler spectrum to enable analysis of objects in motion, and particularly, objects having rotary motion. First and second returned radar signals are mixed with internal signals to obtain an in-phase process signal and a quadrature process signal. A broad-band phase shifter shifts the quadrature signal through 90/degree/ relative to the in-phase signal over a predetermined frequency range. A pair of signals is output from the broad-band phase shifter which are then combined to provide a first side band signal which is functionally related to a negative Doppler shift spectrum. The distinct positive and negative Doppler spectra may then be analyzed for the motion characteristics of the object being examined.

  6. LABORATORY IV CIRCULAR MOTION

    E-Print Network [OSTI]

    Minnesota, University of

    Lab IV - 1 LABORATORY IV CIRCULAR MOTION The problems in this laboratory will help you investigate. OBJECTIVES: After successfully completing this laboratory, you should be able to: · Determine Laboratories I, II, and III. Before coming to the lab you should be able to: · Determine an object

  7. -STABILITY AND VORTEX MOTION IN TYPE II SUPERCONDUCTORS

    E-Print Network [OSTI]

    Spirn, Daniel

    -STABILITY AND VORTEX MOTION IN TYPE II SUPERCONDUCTORS MATTHIAS KURZKE AND DANIEL SPIRN Abstract. 1. Introduction 1.1. Physical background. The evolution of a superconducting material is usu- ally of the magnetic field and the electric field potential for a superconducting sample R2 . The parameter

  8. Generation of Character Motion by Reactive Motion Capture System

    E-Print Network [OSTI]

    Thawonmas, Ruck

    in the human-scale virtual environment. Our purpose is to make character animations with character motion data: Force Feedback, Motion Cap- ture, Human-scale Virtual Environments, Virtual Human 1 Introduction To generate the human motions in virtual envi- ronments made by a computer that are similar to the real world

  9. ur solid Earth undergoes constant change from motions within its core

    E-Print Network [OSTI]

    McLeod, Dennis

    O ur solid Earth undergoes constant change from motions within its core to the surface. Solid Earth is the physical planet we live on, not the oceans or atmosphere. Motions near Earth's cen- ter affect the geodynamo, which generates the Earth's magnetic field. Convection within Earth's mantle drives plate

  10. Motion blur removal from photographs

    E-Print Network [OSTI]

    Cho, Taeg Sang

    2010-01-01

    One of the long-standing challenges in photography is motion blur. Blur artifacts are generated from relative motion between a camera and a scene during exposure. While blur can be reduced by using a shorter exposure, this ...

  11. Stabilization effect of magnetic shear on the diocotron instability Shigeo Kondoh, Tomoya Tatsuno, and Zensho Yoshida

    E-Print Network [OSTI]

    Tatsuno, Tomoya

    the magnetic field. The motion of electrons parallel to the magnetic field cancels the electric charge produced,5 The Prototype Ring Trap Proto-RT experiment1,6,7 is aimed at pure magnetic confinement of a toroidal non in a uniform magnetic field, the diocotron modes propagating in the per- pendicular direction to the magnetic

  12. Operationalization of Relativistic Motion

    E-Print Network [OSTI]

    Bruno Hartmann

    2015-01-08

    We apply the Helmholtz program of basic measurements to relativistic motion. We define a spatiotemporal order by practical comparison: "longer than" if one object or process covers the other. To express its value also numerically (how many times more) we cover them by a locally regular grid of light clocks. We define basic measures from physical operations. Interrelation of measurement operations by different observers reveals a genetic derivation of formal Lorentz transformation. Operationally impracticable configurations for accelerating observers clarify the way out of apparent Twin paradox. From simple measurement-methodical principles - without mathematical presuppositions - we derive all equations of relativistic Kinematics (and next same for classical and relativistic Dynamics).

  13. Fast superconducting magnetic field switch

    DOE Patents [OSTI]

    Goren, Y.; Mahale, N.K.

    1996-08-06

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles. 6 figs.

  14. Fast superconducting magnetic field switch

    DOE Patents [OSTI]

    Goren, Yehuda (Mountain View, CA); Mahale, Narayan K. (The Woodlands, TX)

    1996-01-01

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles.

  15. The Origin of Magnetic Fields

    E-Print Network [OSTI]

    California at Berkeley, University of

    is an aerodynamic drag force resisting motion of the tube through the external, field­free plasma. The mag­ netic of Sun's X­ray Emission: #12; Emerging Active Regions -- what we see at the photo­ sphere: (from Cauzzi buoyancy force, FT is the force due to magnetic tension (field line bending), FC represents the Coriolis

  16. Cosmic magnetism

    SciTech Connect (OSTI)

    Seymour, P.

    1986-01-01

    This book deals with the cosmic magnetism in a non-mathematical way. It uses Faraday's very powerful and highly pictorial concept of lines of magnetic force and their associated physical properties to explain the structure and behavior of magnetic fields in extraterrestrial objects. Contents include: forces of nature; magnetic field of earth; solar and interplanetary magnetic fields; magnetic fields in the solar system; stars and pulsars; and magnetic fields of the milky way and other galaxies.

  17. Kaluza-Klein Magnetized Cylindrical Wormhole

    E-Print Network [OSTI]

    Hashemi, S Sedigheh

    2015-01-01

    A new exact vacuum solution in five dimensions, which describes a magnetized cylindrical wormhole in $3+1$ dimensions is presented. The magnetic field lines are stretched along the wormhole throat and are concentrated near to it. We study the motion of neutral and charged test particles under the influence of the magnetized wormhole. The effective potential for a neutral test particle around and across the magnetized wormhole has a repulsive character. The total magnetic flux on either side of the wormhole is obtained. We present analytic expressions which show regions in which the null energy condition is violated.

  18. Atomic Models for Motional Stark Effects Diagnostics

    SciTech Connect (OSTI)

    Gu, M F; Holcomb, C; Jayakuma, J; Allen, S; Pablant, N A; Burrell, K

    2007-07-26

    We present detailed atomic physics models for motional Stark effects (MSE) diagnostic on magnetic fusion devices. Excitation and ionization cross sections of the hydrogen or deuterium beam traveling in a magnetic field in collisions with electrons, ions, and neutral gas are calculated in the first Born approximation. The density matrices and polarization states of individual Stark-Zeeman components of the Balmer {alpha} line are obtained for both beam into plasma and beam into gas models. A detailed comparison of the model calculations and the MSE polarimetry and spectral intensity measurements obtained at the DIII-D tokamak is carried out. Although our beam into gas models provide a qualitative explanation for the larger {pi}/{sigma} intensity ratios and represent significant improvements over the statistical population models, empirical adjustment factors ranging from 1.0-2.0 must still be applied to individual line intensities to bring the calculations into full agreement with the observations. Nevertheless, we demonstrate that beam into gas measurements can be used successfully as calibration procedures for measuring the magnetic pitch angle through {pi}/{sigma} intensity ratios. The analyses of the filter-scan polarization spectra from the DIII-D MSE polarimetry system indicate unknown channel and time dependent light contaminations in the beam into gas measurements. Such contaminations may be the main reason for the failure of beam into gas calibration on MSE polarimetry systems.

  19. Group Motion Editing Taesoo Kwon

    E-Print Network [OSTI]

    Takahashi, Shigeo

    : I.3.7 [Three-Dimensional Graphics and Realism]: Animation--Virtual reality Keywords: Group Motion Editing, Crowd Simulation, Human Motion, Character Animation 1 Introduction Crowd scenes appear frequently in crowd animation make it possible to synthesize convincing animations of virtual crowds by simulating

  20. A STATISTICAL STUDY OF SHEAR MOTION OF THE FOOTPOINTS IN TWO-RIBBON FLARES Yingna Su,1,2

    E-Print Network [OSTI]

    Su, Yingna

    : corona -- Sun: flares -- Sun: magnetic fields -- Sun: UV radiation 1. INTRODUCTION Solar flares can been reported in almost 20 solar flares, which suggests that this motion may be a common feature in solar flares. In this paper we have made a detailed statistical study of the shear motion

  1. NL3281 Brownian motion 1 NL3281 Brownian motion

    E-Print Network [OSTI]

    Kramer, Peter

    in the relation between the drag force Fdrag and velocity v of the particle in steady state motion (assuming a low Reynolds number): Fdrag = mv. (4) For a sphere of radius a moving through a fluid with dynamic viscosity µ

  2. Magnets & Magnet Condensed Matter Science

    E-Print Network [OSTI]

    McQuade, D. Tyler

    Sights from around the Magnet Lab in 2010. On the cover MAGNETS & MAGNET MATERIALS Engineering materials in Mesoporous Silica SBA-15 31 YBCO Pancake Wound Test Coil for 32-T Magnet Development 32 Strong Vortex Pinning from Marine Cyanobacteria 37 Heavy Petroleum Composition 2. Progression of the Boduszynski Model

  3. Motion Estimation from Disparity Images

    E-Print Network [OSTI]

    Demirdjian, D.

    2001-05-07

    A new method for 3D rigid motion estimation from stereo is proposed in this paper. The appealing feature of this method is that it directly uses the disparity images obtained from stereo matching. We assume that the stereo ...

  4. Motion at low Reynolds number

    E-Print Network [OSTI]

    Tam, Daniel See Wai, 1980-

    2008-01-01

    The work described in this thesis centers on inertialess motion at low Reynolds numbers at the crossroad between biofluids and microfluids. Here we address questions regarding locomotion of micro-swimmers, transport of ...

  5. Tunable Transient Decay Times in Nonlinear Systems: Application to Magnetic Precession

    E-Print Network [OSTI]

    M. G. Phelps; K. L. Livesey; A. M. Ferona; R. E. Camley

    2015-02-03

    The dynamical motion of the magnetization plays a key role in the properties of magnetic materials. If the magnetization is initially away from the equilibrium direction in a magnetic nanoparticle, it will precess at a natural frequency and, with some damping present, will decay to the equilibrium position in a short lifetime. Here we investigate a simple but important situation where a magnetic nanoparticle is driven non-resonantly by an oscillating magnetic field, not at the natural frequency. We find a surprising result that the lifetime of the transient motion is strongly tunable, by factors of over 10,000, by varying the amplitude of the driving field.

  6. On the Crab Proper Motion

    E-Print Network [OSTI]

    PATRIZIA A. CARAVEO; ROBERTO MIGNANI

    1998-11-24

    Owing to the dramatic evolution of telescopes as well as optical detectors in the last 20 yrs, we are now able to measure anew the proper motion of the Crab pulsar, after the classical result of Wyckoff and Murray (1977) in a time span 40 times shorter. The proper motion is aligned with the axis of symmetry of the inner Crab nebula and, presumably, with the pulsar spin axis.

  7. Solar Radiation and Asteroidal Motion

    E-Print Network [OSTI]

    Jozef Klacka

    2000-09-07

    Effects of solar wind and solar electromagnetic radiation on motion of asteroids are discussed. The results complete the statements presented in Vokrouhlick\\'{y} and Milani (2000). As for the effect of electromagnetic radiation, the complete equation of motion is presented to the first order in $v/c$ -- the shape of asteroid (spherical body is explicitly presented) and surface distribution of albedo should be taken into account. Optical quantities must be calculated in proper frame of reference.

  8. Generation of spin-motion entanglement in a trapped ion using long-wavelength radiation

    E-Print Network [OSTI]

    K. Lake; S. Weidt; J. Randall; E. Standing; S. C. Webster; W. K. Hensinger

    2014-11-13

    Applying a magnetic field gradient to a trapped ion allows long-wavelength microwave radiation to produce a mechanical force on the ion's motion when internal transitions are driven. We demonstrate such a coupling using a single trapped \\Yb{171}~ion, and use it to produce entanglement between the spin and motional state, an essential step towards using such a field gradient to implement multi-qubit operations.

  9. A new class of magnetic confinement device in the shape of a knot S.R. Hudson, E. Startsev, and E. Feibush

    E-Print Network [OSTI]

    Hudson, Stuart

    A new class of magnetic confinement device in the shape of a knot S.R. Hudson, E. Startsev, and E) The principle of magnetically confining a plasma exploits the fact that the motion of charged particles in a strong magnetic field consists of a free-streaming motion parallel to the field combined with a small

  10. Large amplitude oscillatory motion along a solar filament

    E-Print Network [OSTI]

    B. Vrsnak; A. M. Veronig; J. K. Thalmann; T. Zic

    2007-07-12

    Large amplitude oscillations of solar filaments is a phenomenon known for more than half a century. Recently, a new mode of oscillations, characterized by periodical plasma motions along the filament axis, was discovered. We analyze such an event, recorded on 23 January 2002 in Big Bear Solar Observatory H$\\alpha$ filtergrams, in order to infer the triggering mechanism and the nature of the restoring force. Motion along the filament axis of a distinct buldge-like feature was traced, to quantify the kinematics of the oscillatory motion. The data were fitted by a damped sine function, to estimate the basic parameters of the oscillations. In order to identify the triggering mechanism, morphological changes in the vicinity of the filament were analyzed. The observed oscillations of the plasma along the filament was characterized by an initial displacement of 24 Mm, initial velocity amplitude of 51 km/s, period of 50 min, and damping time of 115 min. We interpret the trigger in terms of poloidal magnetic flux injection by magnetic reconnection at one of the filament legs. The restoring force is caused by the magnetic pressure gradient along the filament axis. The period of oscillations, derived from the linearized equation of motion (harmonic oscillator) can be expressed as $P=\\pi\\sqrt{2}L/v_{A\\phi}\\approx4.4L/v_{A\\phi}$, where $v_{A\\phi} =B_{\\phi0}/\\sqrt{\\mu_0\\rho}$ represents the Alfv\\'en speed based on the equilibrium poloidal field $B_{\\phi0}$. Combination of our measurements with some previous observations of the same kind of oscillations shows a good agreement with the proposed interpretation.

  11. Superconducting magnets

    SciTech Connect (OSTI)

    Not Available

    1994-08-01

    This report discusses the following topics on superconducting magnets: D19B and -C: The next steps for a record-setting magnet; D20: The push beyond 10 T: Beyond D20: Speculations on the 16-T regime; other advanced magnets for accelerators; spinoff applications; APC materials development; cable and cabling-machine development; and high-{Tc} superconductor at low temperature.

  12. Piezoelectric step-motion actuator

    DOE Patents [OSTI]

    Mentesana; Charles P. (Leawood, KS)

    2006-10-10

    A step-motion actuator using piezoelectric material to launch a flight mass which, in turn, actuates a drive pawl to progressively engage and drive a toothed wheel or rod to accomplish stepped motion. Thus, the piezoelectric material converts electrical energy into kinetic energy of the mass, and the drive pawl and toothed wheel or rod convert the kinetic energy of the mass into the desired rotary or linear stepped motion. A compression frame may be secured about the piezoelectric element and adapted to pre-compress the piezoelectric material so as to reduce tensile loads thereon. A return spring may be used to return the mass to its resting position against the compression frame or piezoelectric material following launch. Alternative embodiment are possible, including an alternative first embodiment wherein two masses are launched in substantially different directions, and an alternative second embodiment wherein the mass is eliminated in favor of the piezoelectric material launching itself.

  13. Barkhausen avalanches in anisotropic ferromagnets with 180 # domain walls Bosiljka Tadic 1,# and Ulrich Nowak 2,##

    E-Print Network [OSTI]

    Usadel, K. D.

    with recently observed behavior in amorphous Metglas and Fe­Co­B ribbons when the applied anisotropic stress of the amorphous Metglas Fe­B­Si [1,7,9] and Fe­Co­B alloys [5,6] which are annealed in a paral­ lel field [9

  14. Self-localized domain walls at -conjugated branching junctions Yongwoo Shin and Xi Lin

    E-Print Network [OSTI]

    Lin, Xi

    's Fermi liquid theory.1 These quasi-particles in conducting polymers, however, are subject to intrinsic, leading to the formation of self- localized charge carriers.2 These phonon-screened charge car- riers the translationally invariant Goldstone mode,5 the am- plitude oscillation mode,3 and a series of other higher order

  15. 2+1 Flavour Domain Wall QCD: light meson spectrum, leptonic decays and neutral kaon mixing 

    E-Print Network [OSTI]

    Antonio, David J

    2008-01-01

    We study light hadron phenomenology using Lattice QCD. We focus on the calculations of the light pseudoscalar quantities: masses, decay constants and B-parameters; in particular the calculation of the Kaon B-parameter, ...

  16. Kinks from Dynamical Systems: Domain Walls in a Deformed O(N) Linear Sigma Model

    E-Print Network [OSTI]

    A. Alonso Izquierdo; M. A. Gonzalez Leon; J. Mateos Guilarte

    2000-03-24

    It is shown how a integrable mechanical system provides all the localized static solutions of a deformation of the linear O(N)-sigma model in two space-time dimensions. The proof is based on the Hamilton-Jacobi separability of the mechanical analogue system that follows when time-independent field configurations are being considered. In particular, we describe the properties of the different kinds of kinks in such a way that a hierarchical structure of solitary wave manifolds emerges for distinct N.

  17. Scaling behavior of domain walls at the T =0 ferromagnet to spin-glass transition

    E-Print Network [OSTI]

    Peinke, Joachim

    ) Disordered model systems, governed by Edwards-Anderson Hamiltonian for Ising spins i =±1: H() = - i,j Jijij Quenched disorder: Jij > 0 : Jij -J2 /2 / 2 + (J -1) =0: SG with Gaussian disorder =1: Ferromagnet Ground states (GSs) Spin

  18. Fast Domain Wall Switching in a Thin Ferroelectric Polymer Jong Yeog Son,a

    E-Print Network [OSTI]

    Lee, EokKyun

    such as nonvolatile memories.8 Meanwhile, scanning probe microscopy SPM on ferroelectric domains has exhibited- namics in PbTiO3 thin films.10,11 Various applications of the SPM method such as piezoresponse force

  19. A Domain Wall Model for SMA Characterization Jordan E. Massad 1 and Ralph C. Smith 2

    E-Print Network [OSTI]

    earthquake-proof structures [1, 21]. More recently, microelectromechanical systems (MEMS) devices have used

  20. Current-driven Domain Wall Dynamics And Its Electric Signature In Ferromagnetic Nanowires 

    E-Print Network [OSTI]

    Liu, Yang

    2012-10-19

    dramatic reduction in heating power thus greatly expanding the range of materials which can be used for spintronic devices. [10, 14] We also note that DMI suppresses critical current jc and a ects parameter a. For vd < vrc, the optimal current coincides...

  1. Nucleon axial charge from quenched lattice QCD with domain wall fermions and improved gauge action

    E-Print Network [OSTI]

    Shoichi Sasaki; Tom Blum; Shigemi Ohta; Kostas Orginos

    2001-10-12

    In our previous DWF calculation with the Wilson gauge action at $\\beta=6.0$ ($a^{-1}\\simeq$ 1.9 GeV) on a $16^3 \\times 32 \\times 16$ lattice, we found that $\\Ga$ had a fairly strong dependence on the quark mass. A simple linear extrapolation of $\\Ga$ to the chiral limit yielded a value that was almost a factor of two smaller than the experimental one. Here we report our recent study of this issue. In particular, we investigate possible errors arising from finite lattice volume, especially in the lighter quark mass region. We employ a RG-improved gauge action (DBW2), which maintains very good chiral behavior even on a coarse lattice ($a^{-1}\\simeq$ 1.3 GeV), in order to perform simulations at large physical volume ($> (2{\\rm fm})^3$). Our preliminary results suggest that the finite volume effect is significant.

  2. Cosmic bubble and domain wall instabilities I: parametric amplification of linear fluctuations

    E-Print Network [OSTI]

    Jonathan Braden; J. Richard Bond; Laura Mersini-Houghton

    2014-12-17

    This is the first paper in a series where we study collisions of nucleated bubbles taking into account the effects of small initial (quantum) fluctuations in a fully 3+1-dimensional setting. In this paper, we consider the evolution of linear fluctuations around highly symmetric though inhomogeneous backgrounds. We demonstrate that a large degree of asymmetry develops over time from tiny fluctuations superposed upon planar and SO(2,1) symmetric backgrounds. These fluctuations arise from zero-point vacuum oscillations, so excluding them by enforcing a spatial symmetry is inconsistent in a quantum treatment. We consider the limit of two colliding planar walls, with fluctuation mode functions characterized by the wavenumber transverse to the collision direction and a longitudinal shape along the collision direction $x$, which we solve for. Initially, the fluctuations obey a linear wave equation with a time- and space-dependent mass $m_{eff}(x,t)$. When the walls collide multiple times, $m_{eff}$ oscillates in time. We use Floquet theory to study the fluctuations and generalize techniques familiar from preheating to the case with many coupled degrees of freedom. This inhomogeneous case has bands of unstable transverse wavenumbers $k_\\perp$ with exponentially growing mode functions. From the detailed spatial structure of the mode functions in $x$, we identify both broad and narrow parametric resonance generalizations of the homogeneous $m_{eff}(t)$ case of preheating. The unstable $k_\\perp$ modes are longitudinally localized, yet can be described as quasiparticles in the Bogoliubov sense. We define an effective occupation number to show they are created in bursts for the case of well-defined collisions in the background. The transverse-longitudinal coupling accompanying nonlinearity radically breaks this localized particle description, with nonseparable 3D modes arising.

  3. Domain walls as dark energy (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) | SciTech Connect Discrimination ofDynamics ModelPorous

  4. Domain walls in a Born-Infeld-dilaton background (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) | SciTech Connect Discrimination ofDynamics ModelPorousSciTech

  5. Dynamic domain walls in a Maxwell-dilaton background (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) | SciTech Connect Discriminationquenchedwithimpact on

  6. Particle energization through time-periodic helical magnetic fields

    E-Print Network [OSTI]

    Mitra, Dhrubaditya

    We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with coefficients A=B=C=1 are chaotic, and we show ...

  7. Motion Processing and From-from-Apparent-Motion in Infancy 

    E-Print Network [OSTI]

    Hirshkowitz, Amy

    2014-08-05

    information within the displays. In these form-from-apparent-motion (FFAM) displays, red “background” random dots are set against an overall white background, with a portion of the random dots set as green “foreground” dots. Although the dots do not move...

  8. CORONAL MAGNETIC FIELD MEASUREMENTS THROUGH GYRORESONANCE EMISSION

    E-Print Network [OSTI]

    White, Stephen

    . The spiralling motion of electrons in the 200­ 2000 G fields in the solar corona produces sufficient opacity to render the corona optically thick, making it easy to recognize such sources in microwave images from. Keywords: Sun, solar corona, solar magnetic fields, solar radio emission Introduction Since the realization

  9. Space and motion : data based rules of public space pedestrian motion

    E-Print Network [OSTI]

    Gonzalez Rojas, Paloma (Paloma Francisca)

    2015-01-01

    The understanding of space relies on motion, as we experience space by crossing it. While in motion we sense the environment in time, interacting with space. The vision of this thesis is to incorporate people's motion into ...

  10. Can We Distinguish Biological Motions of Virtual Humans? Perceptual Study With Captured Motions of Weight Lifting.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Information Systems-- Animations ­ Artificial, augmented, and virtual realities Keywords: Human Motions performing various interactions in VE. Animating virtual humans to perform these tasks involves taking manyCan We Distinguish Biological Motions of Virtual Humans? Perceptual Study With Captured Motions

  11. THE CONNECTION BETWEEN INTERNETWORK MAGNETIC ELEMENTS AND SUPERGRANULAR FLOWS

    SciTech Connect (OSTI)

    Orozco Suarez, D.; Katsukawa, Y.; Bellot Rubio, L. R.

    2012-10-20

    The advection of internetwork magnetic elements by supergranular convective flows is investigated using high spatial resolution, high cadence, and high signal-to-noise ratio Na I D1 magnetograms obtained with the Hinode satellite. The observations show that magnetic elements appear everywhere across the quiet Sun surface. We calculate the proper motion of these magnetic elements with the aid of a feature tracking algorithm. The results indicate that magnetic elements appearing in the interior of supergranules tend to drift toward the supergranular boundaries with a non-constant velocity. The azimuthally averaged radial velocities of the magnetic elements and of the supergranular flow, calculated from a local correlation tracking technique applied to Dopplergrams, are very similar. This suggests that, in the long term, surface magnetic elements are advected by supergranular flows, although on short timescales their very chaotic motions are driven mostly by granular flows and other processes.

  12. Magnetically-actuated artificial cilia for microfluidic propulsion

    E-Print Network [OSTI]

    Khaderi, S N; Anderson, P D; Ioan, D; Toonder, J M J den; Onck, P R

    2009-01-01

    Natural cilia are hair-like microtubule-based structures that are able to move fluid at low Reynolds number through asymmetric motion. In this paper we follow a biomimetic approach to design artificial cilia lining the inner surface of microfluidic channels with the goal to propel fluid. The artificial cilia consist of polymer films filled with magnetic nanoparticles. The asymmetric, non-reciprocating motion is generated by tuning an external magnetic field. To obtain the magnetic field and associated magnetization local to the cilia we solve the Maxwell equations, from which the magnetic torques can be deduced. To obtain the ciliary motion we solve the dynamic equations of motion which are then fully coupled to the fluid dynamic equations that describe fluid flow around the cilia. By doing so we show that by properly tuning the applied magnetic field, asymmetric ciliary motion can be generated that is able to propel fluid in a microchannel. The results are presented in terms of three dimensionless parameters...

  13. 1 Introduction Synthetic motion capture

    E-Print Network [OSTI]

    Terzopoulos, Demetri

    animation of animals in virtual worlds, but at significant computational cost. Syn- thetic motion capture). Lifelike virtual animals naturally beckon active in- volvement, and one feels compelled to interact also form the basis of Miller's snakes and worms (Miller 1988), the virtual humans of Hodgins et al

  14. Unwinding motion of a twisted active region filament

    SciTech Connect (OSTI)

    Yan, X. L.; Xue, Z. K.; Kong, D. F.; Liu, J. H.; Xu, C. L.

    2014-12-10

    To better understand the structures of active region filaments and the eruption process, we study an active region filament eruption in active region NOAA 11082 in detail on 2010 June 22. Before the filament eruption, the opposite unidirectional material flows appeared in succession along the spine of the filament. The rising of the filament triggered two B-class flares at the upper part of the filament. As the bright material was injected into the filament from the sites of the flares, the filament exhibited a rapid uplift accompanying the counterclockwise rotation of the filament body. From the expansion of the filament, we can see that the filament consisted of twisted magnetic field lines. The total twist of the filament is at least 5? obtained by using a time slice method. According to the morphology change during the filament eruption, it is found that the active region filament was a twisted flux rope and its unwinding motion was like a solar tornado. We also find that there was a continuous magnetic helicity injection before and during the filament eruption. It is confirmed that magnetic helicity can be transferred from the photosphere to the filament. Using the extrapolated potential fields, the average decay index of the background magnetic fields over the filament is 0.91. Consequently, these findings imply that the mechanism of solar filament eruption could be due to the kink instability and magnetic helicity accumulation.

  15. Magnetic shielding

    DOE Patents [OSTI]

    Kerns, J.A.; Stone, R.R.; Fabyan, J.

    1987-10-06

    A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient magnetic field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines. 3 figs.

  16. Magnetic shielding

    DOE Patents [OSTI]

    Kerns, John A. (Livermore, CA); Stone, Roger R. (Walnut Creek, CA); Fabyan, Joseph (Livermore, CA)

    1987-01-01

    A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient magnetic field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

  17. Automatic Head Motion Prediction from Speech Data 

    E-Print Network [OSTI]

    Hofer, Gregor; Shimodaira, Hiroshi

    2007-01-01

    In this paper we present a novel approach to generate a sequence of head motion units given some speech. The modelling approach is based on the notion that head motion can be divided into a number of short homogeneous ...

  18. Metrics for sampling-based motion planning 

    E-Print Network [OSTI]

    Morales Aguirre, Marco Antonio

    2009-05-15

    A motion planner finds a sequence of potential motions for a robot to transit from an initial to a goal state. To deal with the intractability of this problem, a class of methods known as sampling-based planners build ...

  19. Experimental wave effect on vertical relative motion 

    E-Print Network [OSTI]

    Padmanabhan, Rajith

    2007-09-17

    Ship motions are influenced by the sea state. Conventionally the responses are calculated in the frequency domain. This method, however, is valid only for narrow band spectra. As the seaway becomes more nonlinear, the ship motions cannot be readily...

  20. Magnetic shielding

    DOE Patents [OSTI]

    Kerns, J.A.; Stone, R.R.; Fabyan, J.

    1985-02-12

    A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

  1. Magnetic nanotubes

    DOE Patents [OSTI]

    Matsui, Hiroshi (Glen Rock, NJ); Matsunaga, Tadashi (Tokyo, JP)

    2010-11-16

    A magnetic nanotube includes bacterial magnetic nanocrystals contacted onto a nanotube which absorbs the nanocrystals. The nanocrystals are contacted on at least one surface of the nanotube. A method of fabricating a magnetic nanotube includes synthesizing the bacterial magnetic nanocrystals, which have an outer layer of proteins. A nanotube provided is capable of absorbing the nanocrystals and contacting the nanotube with the nanocrystals. The nanotube is preferably a peptide bolaamphiphile. A nanotube solution and a nanocrystal solution including a buffer and a concentration of nanocrystals are mixed. The concentration of nanocrystals is optimized, resulting in a nanocrystal to nanotube ratio for which bacterial magnetic nanocrystals are immobilized on at least one surface of the nanotubes. The ratio controls whether the nanocrystals bind only to the interior or to the exterior surfaces of the nanotubes. Uses include cell manipulation and separation, biological assay, enzyme recovery, and biosensors.

  2. Simple Harmonic Motion and Newton's 3rd

    E-Print Network [OSTI]

    Yu, Jaehoon

    Simple Harmonic Motion and Newton's 3rd Law Theory Simple Harmonic Motion is not as simpleperiod where m is the mass of the object in kilograms and k is the spring constant. Newton's 3rd Law Newton's 3rd Law using two Force sensors. Procedure: Simple Harmonic Motion Getting the data 1. Open

  3. Wave Motion Unit code: MATH35012

    E-Print Network [OSTI]

    Sidorov, Nikita

    MATH35012 Wave Motion Unit code: MATH35012 Credit Rating: 10 Unit level: Level 3 Teaching period This course unit aims to elucidate some of the physical properties of important types of wave motion and their mathematical descriptions. Overview Wave motion occurs in the oceans, atmosphere and in the earth. Problems

  4. Magnetic levitation system for moving objects

    DOE Patents [OSTI]

    Post, Richard F. (Walnut Creek, CA)

    1998-01-01

    Repelling magnetic forces are produced by the interaction of a flux-concentrated magnetic field (produced by permanent magnets or electromagnets) with an inductively loaded closed electric circuit. When one such element moves with respect to the other, a current is induced in the circuit. This current then interacts back on the field to produce a repelling force. These repelling magnetic forces are applied to magnetically levitate a moving object such as a train car. The power required to levitate a train of such cars is drawn from the motional energy of the train itself, and typically represents only a percent or two of the several megawatts of power required to overcome aerodynamic drag at high speeds.

  5. Magnetic levitation system for moving objects

    DOE Patents [OSTI]

    Post, R.F.

    1998-03-03

    Repelling magnetic forces are produced by the interaction of a flux-concentrated magnetic field (produced by permanent magnets or electromagnets) with an inductively loaded closed electric circuit. When one such element moves with respect to the other, a current is induced in the circuit. This current then interacts back on the field to produce a repelling force. These repelling magnetic forces are applied to magnetically levitate a moving object such as a train car. The power required to levitate a train of such cars is drawn from the motional energy of the train itself, and typically represents only a percent or two of the several megawatts of power required to overcome aerodynamic drag at high speeds. 7 figs.

  6. Motion Patches: Building Blocks for Virtual Environments Annotated with Motion Data

    E-Print Network [OSTI]

    Lee, Jehee

    Motion Patches: Building Blocks for Virtual Environments Annotated with Motion Data Kang Hoon Lee motion data can be transferred to the target environment. These building blocks annotated Myung Geol Choi Jehee Lee Seoul National University Motion capture from the source environment Building

  7. A Randomized Controlled Trial of Lorazepam to Reduce Liver Motion in Patients Receiving Upper Abdominal Radiation Therapy

    SciTech Connect (OSTI)

    Tsang, Derek S.; Voncken, Francine E.M.; Tse, Regina V.; Sykes, Jenna; Wong, Rebecca K.S.; Dinniwell, Rob E.; Kim, John; Ringash, Jolie; Brierley, James D.; Cummings, Bernard J.; Brade, Anthony; Dawson, Laura A.

    2013-12-01

    Purpose: Reduction of respiratory motion is desirable to reduce the volume of normal tissues irradiated, to improve concordance of planned and delivered doses, and to improve image guided radiation therapy (IGRT). We hypothesized that pretreatment lorazepam would lead to a measurable reduction of liver motion. Methods and Materials: Thirty-three patients receiving upper abdominal IGRT were recruited to a double-blinded randomized controlled crossover trial. Patients were randomized to 1 of 2 study arms: arm 1 received lorazepam 2 mg by mouth on day 1, followed by placebo 4 to 8 days later; arm 2 received placebo on day 1, followed by lorazepam 4 to 8 days later. After tablet ingestion and daily radiation therapy, amplitude of liver motion was measured on both study days. The primary outcomes were reduction in craniocaudal (CC) liver motion using 4-dimensional kV cone beam computed tomography (CBCT) and the proportion of patients with liver motion ?5 mm. Secondary endpoints included motion measured with cine magnetic resonance imaging and kV fluoroscopy. Results: Mean relative and absolute reduction in CC amplitude with lorazepam was 21% and 2.5 mm respectively (95% confidence interval [CI] 1.1-3.9, P=.001), as assessed with CBCT. Reduction in CC amplitude to ?5 mm residual liver motion was seen in 13% (95% CI 1%-25%) of patients receiving lorazepam (vs 10% receiving placebo, P=NS); 65% (95% CI 48%-81%) had reduction in residual CC liver motion to ?10 mm (vs 52% with placebo, P=NS). Patients with large respiratory movement and patients who took lorazepam ?60 minutes before imaging had greater reductions in liver CC motion. Mean reductions in liver CC amplitude on magnetic resonance imaging and fluoroscopy were nonsignificant. Conclusions: Lorazepam reduces liver motion in the CC direction; however, average magnitude of reduction is small, and most patients have residual motion >5 mm.

  8. The transverse and rotational motions of magnetohydrodynamic kink waves in the solar atmosphere

    SciTech Connect (OSTI)

    Goossens, M.; Van Doorsselaere, T. [Centre for Mathematical Plasma Astrophysics, Katholieke Universiteit Leuven, Celestijnenlaan 200B, bus 2400, B-3001 Herverlee (Belgium); Soler, R.; Terradas, J. [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Verth, G., E-mail: marcel.goossens@wis.kuleuven.be [Solar Physics and Space Plasma Research Centre (SP2RC), The University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2014-06-10

    Magnetohydrodynamic (MHD) kink waves have now been observed to be ubiquitous throughout the solar atmosphere. With modern instruments, they have now been detected in the chromosphere, interface region, and corona. The key purpose of this paper is to show that kink waves do not only involve purely transverse motions of solar magnetic flux tubes, but the velocity field is a spatially and temporally varying sum of both transverse and rotational motion. Taking this fact into account is particularly important for the accurate interpretation of varying Doppler velocity profiles across oscillating structures such as spicules. It has now been shown that, as well as bulk transverse motions, spicules have omnipresent rotational motions. Here we emphasize that caution should be used before interpreting the particular MHD wave mode/s responsible for these rotational motions. The rotational motions are not necessarily signatures of the classic axisymmetric torsional Alfvén wave alone, because kink motion itself can also contribute substantially to varying Doppler velocity profiles observed across these structures. In this paper, the displacement field of the kink wave is demonstrated to be a sum of its transverse and rotational components, both for a flux tube with a discontinuous density profile at its boundary, and one with a more realistic density continuum between the internal and external plasma. Furthermore, the Doppler velocity profile of the kink wave is forward modeled to demonstrate that, depending on the line of sight, it can either be quite distinct or very similar to that expected from a torsional Alfvén wave.

  9. PCA-based lung motion model

    E-Print Network [OSTI]

    Li, Ruijiang; Jia, Xun; Zhao, Tianyu; Lamb, James; Yang, Deshan; Low, Daniel A; Jiang, Steve B

    2010-01-01

    Organ motion induced by respiration may cause clinically significant targeting errors and greatly degrade the effectiveness of conformal radiotherapy. It is therefore crucial to be able to model respiratory motion accurately. A recently proposed lung motion model based on principal component analysis (PCA) has been shown to be promising on a few patients. However, there is still a need to understand the underlying reason why it works. In this paper, we present a much deeper and detailed analysis of the PCA-based lung motion model. We provide the theoretical justification of the effectiveness of PCA in modeling lung motion. We also prove that under certain conditions, the PCA motion model is equivalent to 5D motion model, which is based on physiology and anatomy of the lung. The modeling power of PCA model was tested on clinical data and the average 3D error was found to be below 1 mm.

  10. Magnetic monopoles

    SciTech Connect (OSTI)

    Fryberger, D.

    1984-12-01

    In this talk on magnetic monopoles, first the author briefly reviews some historical background; then, the author describes what several different types of monopoles might look like; and finally the author discusses the experimental situation. 81 references.

  11. Complex motion of precipitation bands

    E-Print Network [OSTI]

    Lagzi, I; Rácz, Z; Lagzi, Istvan; Papai, Peter; Racz, Zoltan

    2006-01-01

    Formation and dynamics of an Al(OH)_3 precipitation ring is studied by diffusing NaOH into a gel containing AlCl_3. Limited feeding of the outer electrolyte (NaOH) is found to yield an intricate ring-dynamics which involves stopping and reversal of the direction of motion of the precipitation ring, and evolution into stationary multi-ring structures. A model of the ring-dynamics is developed by combining a phase separation scenario for the precipitation with the redissolution (complex formation) of the precipitate in the excess of the outer electrolyte.

  12. On the relationship between photospheric footpoint motions and coronal heating in solar active regions

    SciTech Connect (OSTI)

    Van Ballegooijen, A. A.; Asgari-Targhi, M.; Berger, M. A.

    2014-05-20

    Coronal heating theories can be classified as either direct current (DC) or alternating current (AC) mechanisms, depending on whether the coronal magnetic field responds quasi-statically or dynamically to the photospheric footpoint motions. In this paper we investigate whether photospheric footpoint motions with velocities of 1-2 km s{sup –1} can heat the corona in active regions, and whether the corona responds quasi-statically or dynamically to such motions (DC versus AC heating). We construct three-dimensional magnetohydrodynamic models for the Alfvén waves and quasi-static perturbations generated within a coronal loop. We find that in models where the effects of the lower atmosphere are neglected, the corona responds quasi-statically to the footpoint motions (DC heating), but the energy flux into the corona is too low compared to observational requirements. In more realistic models that include the lower atmosphere, the corona responds more dynamically to the footpoint motions (AC heating) and the predicted heating rates due to Alfvén wave turbulence are sufficient to explain the observed hot loops. The higher heating rates are due to the amplification of Alfvén waves in the lower atmosphere. We conclude that magnetic braiding is a highly dynamic process.

  13. Development of a 6-degree-of-freedom magnetically levitated instrument with nanometer precision 

    E-Print Network [OSTI]

    Gu, Jie

    2004-09-30

    This thesis presents the design and fabrication of a novel magnetically levitated (maglev) device with six-degree-of-freedom motion capability at nanometer precision. The applications of this device are manufacture of nanoscale structures, assembly...

  14. Approaches to Creating and Controlling Motion in MRI Gregory S. Fischer, Member, IEEE, Gregory Cole, Student Member, IEEE and Hao Su, Student Member, IEEE

    E-Print Network [OSTI]

    Camesano, Terri

    Approaches to Creating and Controlling Motion in MRI Gregory S. Fischer, Member, IEEE, Gregory Cole, Student Member, IEEE and Hao Su, Student Member, IEEE Abstract-- Magnetic Resonance Imaging (MRI) can is complicated by factors including: the high magnetic field strength, the requirement that such devices should

  15. Nonlinear motion of coupled magnetic vortices in ferromagnetic/non-magnetic/ferromagnetic trilayer

    E-Print Network [OSTI]

    Jun, Su-Hyeong

    2010-01-01

    o f nanometer scale spintronic devices and memory devices [4]. In the realization o f spintronic and memory devices,

  16. Liouville Brownian motion at criticality

    E-Print Network [OSTI]

    Rémi Rhodes; Vincent Vargas

    2015-02-15

    In this paper, we construct the Brownian motion of Liouville Quantum Gravity with central charge $c=1$ (more precisely we restrict to the corresponding free field theory). Liouville quantum gravity with $c=1$ corresponds to two-dimensional string theory and is the conjectural scaling limit of large planar maps weighted with a $O(n=2)$ loop model or a $Q=4$-state Potts model embedded in a two dimensional surface in a conformal manner. Following \\cite{GRV1}, we start by constructing the critical LBM from one fixed point $x\\in\\mathbb{R}^2$ (or $x\\in\\S^2$), which amounts to changing the speed of a standard planar Brownian motion depending on the local behaviour of the critical Liouville measure $M'(dx)=-X(x)e^{2X(x)}\\,dx$ (where $X$ is a Gaussian Free Field, say on $\\mathbb{S}^2$). Extending this construction simultaneously to all points in $\\mathbb{R}^2$ requires a fine analysis of the potential properties of the measure $M'$. This allows us to construct a strong Markov process with continuous sample paths living on the support of $M'$, namely a dense set of Hausdorff dimension $0$. We finally construct the associated Liouville semigroup, resolvent, Green function, heat kernel and Dirichlet form. In passing, we extend to quite a general setting the construction of the critical Gaussian multiplicative chaos that was initiated in \\cite{Rnew7,Rnew12} and also establish new capacity estimates for the critical Gaussian multiplicative chaos.

  17. Motion of a helical vortex

    E-Print Network [OSTI]

    Fuentes, Oscar Velasco

    2015-01-01

    We study the motion of a single helical vortex in an unbounded, inviscid, incompressible fluid. The vortex is an infinite tube whose centerline is a helix and whose cross section is a circle of small radius (compared to the radius of curvature) where the vorticity is uniform and parallel to the centerline. Ever since Joukowsky (1912) deduced that this vortex translates and rotates steadily without change of form, numerous attempts have been made to compute these self-induced velocities. Here we use Hardin's (1982) solution for the velocity field to find new expressions for the vortex's linear and angular velocities. Our results, verified by numerically computing the Helmholtz integral and the Rosenhead-Moore approximation to the Biot-Savart law, are more accurate than previous results over the whole range of values of the vortex pitch and cross-section. We then use the new formulas to study the advection of passive particles near the vortex; we find that the vortex's motion and capacity to transport fluid dep...

  18. Magnetic Braiding and Parallel Electric Fields

    E-Print Network [OSTI]

    A. L. Wilmot-Smith; G. Hornig; D. I. Pontin

    2008-10-08

    The braiding of the solar coronal magnetic field via photospheric motions - with subsequent relaxation and magnetic reconnection -- is one of the most widely debated ideas of solar physics. We readdress the theory in the light of developments in three-dimensional magnetic reconnection theory. It is known that the integrated parallel electric field along field lines is the key quantity determining the rate of reconnection, in contrast with the two-dimensional case where the electric field itself is the important quantity. We demonstrate that this difference becomes crucial for sufficiently complex magnetic field structures. A numerical method is used to relax a braided magnetic field to an ideal force-free equilibrium; that equilibrium is found to be smooth, with only large- scale current structures. However, the equilibrium is shown to have a highly filamentary integrated parallel current structure with extremely short length- scales. An analytical model is developed to show that, in a coronal situation, the length scales associated with the integrated parallel current structures will rapidly decrease with increasing complexity, or degree of braiding, of the magnetic field. Analysis shows the decrease in these length scales will, for any finite resistivity, eventually become inconsistent with the stability of a force- free field. Thus the inevitable consequence of the magnetic braiding process is shown to be a loss of equilibrium of the coronal field, probably via magnetic reconnection events.

  19. Electric Magnetic Duality in String Theory

    E-Print Network [OSTI]

    Ashoke Sen

    1992-10-06

    The electric-magnetic duality transformation in four dimensional heterotic string theory discussed by Shapere, Trivedi and Wilczek is shown to be an exact symmetry of the equations of motion of low energy effective field theory even after including the scalar and the vector fields, arising due to compactification, in the effective field theory. Using this duality transformation we construct rotating black hole solutions in the effective field theory carrying both, electric and magnetic charges. The spectrum of extremal magnetically charged black holes turns out to be similar to that of electrically charged elementary string excitations. We also discuss the possibility that the duality symmetry is an exact symmetry of the full string theory under which electrically charged elementary string excitations get exchanged with magnetically charged soliton like solutions. This proposal might be made concrete following the suggestion of Dabholkar et. al. that fundamental strings may be regarded as soliton like classical solutions in the effective field theory.

  20. Novel energy level structure of Dirac oscillator in magnetic field

    E-Print Network [OSTI]

    Md. Moniruzzaman; S. B. Faruque

    2015-08-12

    We have presented an elegant high energy quantum problem, namely, the full Dirac oscillator under axial magnetic field with its full solution. We have found the energy spectrum which is rich and at the same time has a novel structure. The quantized energy levels show coupling of the oscillator frequency with the Larmor frequency in the 2D surface where the electrons under consideration follow a 2D oscillator. The axis in which magnetic field is pointed, the electrons follow a 1D oscillator. There is also coupling between spin and orbital motion and also a coupling between a resultant effect of orbital and spin motion with Larmor precession.

  1. Symmetry in the retinogeniculate motion circuit /

    E-Print Network [OSTI]

    Kaye, Alfred

    2013-01-01

    cortical stages of processing, retinal direction selectivityfeatures of retinal mo- tion processing with the efficientretinal ganglion cell subtypes and brain structures involved in motion processing.

  2. Magnet Cable Manufacturing

    E-Print Network [OSTI]

    Royet, J.M.

    2011-01-01

    J. Royet, "Magnet Cable Manufacturing", oral presentation atDivision Magnet Cable Manufacturing J. Royet October 1990J I Magnet Cable Manufacturing* John Royet Accelerator &

  3. Noninvasive valve monitor using constant magnetic and/or DC electromagnetic field

    DOE Patents [OSTI]

    Casada, Donald A. (Knoxville, TN); Haynes, Howard D. (Knoxville, TN)

    1993-01-01

    One or more sources of steady magnetic field are carefully located on the outside of a valve body. The constant magnetic field is transmitted into the valve body and valve internals. A magnetic field detector carefully located on the outside of the valve body detects the intensity of the magnetic field at its location. As the position of a valve internal part is changed, there is an alteration in the magnetic field in the valve, and a consequent change in the detected magnetic field. Changes in the detected signal provide an indication of the position and motion of the valve internals.

  4. Magnetic Stereoscopy

    E-Print Network [OSTI]

    Thomas Wiegelmann; Bernd Inhester

    2006-12-21

    The space mission STEREO will provide images from two viewpoints. An important aim of the STEREO mission is to get a 3D view of the solar corona. We develop a program for the stereoscopic reconstruction of 3D coronal loops from images taken with the two STEREO spacecraft. A pure geometric triangulation of coronal features leads to ambiguities because the dilute plasma emissions complicates the association of features in image 1 with features in image 2. As a consequence of these problems the stereoscopic reconstruction is not unique and multiple solutions occur. We demonstrate how these ambiguities can be resolved with the help of different coronal magnetic field models (potential, linear and non-linear force-free fields). The idea is that, due to the high conductivity in the coronal plasma, the emitting plasma outlines the magnetic field lines. Consequently the 3D coronal magnetic field provides a proxy for the stereoscopy which allows to eliminate inconsistent configurations. The combination of stereoscopy and magnetic modelling is more powerful than one of these tools alone. We test our method with the help of a model active region and plan to apply it to the solar case as soon as STEREO data become available.

  5. A ash-drag effect in random motion reveals involvement of preattentive motion processing

    E-Print Network [OSTI]

    Whitney, David

    A ash-drag effect in random motion reveals involvement of preattentive motion processing Department-ku, Tokyo, JapanIkuya Murakami The ash-drag (FDE) effect refers to the phenomenon in which the position of a stationary ashed object in one location appears shifted in the direction of nearby motion. Over the past

  6. Vision Research 40 (2000) 21352147 Visual motion of missing-fundamental patterns: motion energy

    E-Print Network [OSTI]

    He, Sheng

    2000-01-01

    Vision Research 40 (2000) 2135­2147 Visual motion of missing-fundamental patterns: motion energy-fundamental chromatic gratings and plaids, at approximate isoluminance, and missing-fundamen- tal luminance barberpoles: Motion energy; Feature tracking; Missing fundamental pattern; Plaids; Barberpole www

  7. The Motion Of A Spring Released From Uniform Circular Motion

    E-Print Network [OSTI]

    Dooling, Thomas; Carnaghi, Matthew; Titus, Aaron

    2015-01-01

    A weak spring is connected at one end to a rotor turning at constant angular velocity. The spring extends to a stretched length as determined by the spring mass, rest length, spring constant, rotor radius and rotor angular velocity. When released from the rotor, the inner end of the spring pulls away as expected, causing a wave to travel down the spring as it collapses. During this time interval, the outer end of the spring continues to move along its original circular path in uniform circular motion, as if the spring were still connected to the rotor. This is analogous to the effect of a hanging Slinky released from rest whose bottom end remains at a fixed position above the ground until a wave from the top of the Slinky reaches the bottom of the Slinky. Values from a numerical model and measurements from video analysis show that upon release the inner end travels along a circle of similar radius as the outer end. The effect appears as a series of alternating semi-circles. In addition, the simulation and dat...

  8. An Architecture for Motion Capture Animation

    E-Print Network [OSTI]

    de Figueiredo, Luiz Henrique

    An Architecture for Motion Capture Animation Fernando Wagner da Silva Luiz Velho Jonas Gomes Paulo System's Architecture q Conclusions q Future work / Work in progress General Outline #12;q Motion systems Our Motivation #12;q MoCap as main animation tool q Modular architecture (Input, Processing

  9. DEFENDANTS' SUPPLEMENTAL MEMORANDUM RE: MOTIONS TO

    E-Print Network [OSTI]

    Gollin, George

    DEFENDANTS' SUPPLEMENTAL MEMORANDUM RE: MOTIONS TO SUPPRESS AND DISMISS - 1 - Richard D. Wall. ) ) ) ) ) ) ) ) ) ) ) ) ) Case No.: CR-05-180-7-LRS DEFENDANTS' SUPPLEMENTAL MEMORANDUM RE: MOTIONS TO SUPPRESS AND DISMISS ) Defendants jointly submit the following supplemental memorandum of points and authorities re: Defendants

  10. Learning Dynamic Arm Motions for Postural Recovery

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Learning Dynamic Arm Motions for Postural Recovery Scott Kuindersma, Roderic Grupen, Andrew Barto}@cs.umass.edu Abstract--The biomechanics community has recently made progress toward understanding the role of rapid arm of arm recovery motions in humans and experimentally demonstrate advantages of this behavior

  11. Robot Motion Planning with Uncertainty The Challenge

    E-Print Network [OSTI]

    Whitton, Mary C.

    Roadmap (SMR), a new motion planning framework that explicitly considers uncertainty in robot motion approach. Our framework builds on the highly successful approach used in Probabilistic Roadmaps (PRMs of discrete states is selected in the state space, and a roadmap is built that represents their collision

  12. Appendix E: Software Video Analysis of Motion

    E-Print Network [OSTI]

    Minnesota, University of

    E - 1 Appendix E: Software Video Analysis of Motion Analyzing pictures (movies or videos using a computer and data acquisition software. This appendix will guide a person somewhat familiar: SOFTWARE E - 2 Using video to analyze motion is a two-step process. The first step is recording a video

  13. Robot Motion Planning with Uncertainty The Challenge

    E-Print Network [OSTI]

    Pollefeys, Marc

    to address this problem. One of them, the Stochastic Motion Roadmap (SMR), is a new motion planning framework in Probabilistic Roadmaps (PRMs): a learning phase followed by a query phase. During the learning phase, a random (or quasi-random) sample of discrete states is selected in the state space, and a roadmap is built

  14. Roadmapbased Motion Planning in Dynamic Environments

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Roadmap­based Motion Planning in Dynamic Environments Jur P. van den Berg Mark H. Overmars.cs.uu.nl #12; Roadmap­based Motion Planning in Dynamic Environments Jur P. van den Berg Mark H. Overmars April obstacles. We propose a practical algorithm based on a roadmap that is created for the static part

  15. VISIBILITYBASED PROBABILISTIC ROADMAPS FOR MOTION PLANNING

    E-Print Network [OSTI]

    Cortés, Juan

    VISIBILITY­BASED PROBABILISTIC ROADMAPS FOR MOTION PLANNING T. Sim'eon, J­P. Laumond, and C a variant of Probabilistic Roadmap Methods (PRM) that recently appeared as a promising approach to motion to produce small roadmaps, called visibility roadmaps. Our algorithm integrates an original termination

  16. Seismic switch for strong motion measurement

    DOE Patents [OSTI]

    Harben, Philip E. (Oakley, CA); Rodgers, Peter W. (Santa Barbara, CA); Ewert, Daniel W. (Patterson, CA)

    1995-01-01

    A seismic switching device that has an input signal from an existing microseismic station seismometer and a signal from a strong motion measuring instrument. The seismic switch monitors the signal level of the strong motion instrument and passes the seismometer signal to the station data telemetry and recording systems. When the strong motion instrument signal level exceeds a user set threshold level, the seismometer signal is switched out and the strong motion signal is passed to the telemetry system. The amount of time the strong motion signal is passed before switching back to the seismometer signal is user controlled between 1 and 15 seconds. If the threshold level is exceeded during a switch time period, the length of time is extended from that instant by one user set time period.

  17. Seismic switch for strong motion measurement

    DOE Patents [OSTI]

    Harben, P.E.; Rodgers, P.W.; Ewert, D.W.

    1995-05-30

    A seismic switching device is described that has an input signal from an existing microseismic station seismometer and a signal from a strong motion measuring instrument. The seismic switch monitors the signal level of the strong motion instrument and passes the seismometer signal to the station data telemetry and recording systems. When the strong motion instrument signal level exceeds a user set threshold level, the seismometer signal is switched out and the strong motion signal is passed to the telemetry system. The amount of time the strong motion signal is passed before switching back to the seismometer signal is user controlled between 1 and 15 seconds. If the threshold level is exceeded during a switch time period, the length of time is extended from that instant by one user set time period. 11 figs.

  18. Bounding Lorentz violation at particle colliders by tracking the motion of charged particles

    SciTech Connect (OSTI)

    Altschul, Brett [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina 29208 (United States)

    2011-10-01

    In the presence of Lorentz violation, the motion of a charged particle in a magnetic field is distorted. By measuring the eccentricities of particles' elliptical orbits and studying how those eccentricities vary with the absolute orientation of the laboratory, it is possible to constrain the Lorentz-violating c{sub JK} parameters. For each observed species, this method can provide constraints on four linear combinations of coefficients for which, in some species, there are presently no two-sided bounds.

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

    E-Print Network [OSTI]

    H. Yan; B. Plaster

    2011-04-07

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

  20. Magnetic Reconnection

    SciTech Connect (OSTI)

    Masaaki Yamada, Russell Kulsrud and Hantao Ji

    2009-09-17

    We review the fundamental physics of magnetic reconnection in laboratory and space plasmas, by discussing results from theory, numerical simulations, observations from space satellites, and the recent results from laboratory plasma experiments. After a brief review of the well-known early work, we discuss representative recent experimental and theoretical work and attempt to interpret the essence of significant modern findings. In the area of local reconnection physics, many significant findings have been made with regard to two- uid physics and are related to the cause of fast reconnection. Profiles of the neutral sheet, Hall currents, and the effects of guide field, collisions, and micro-turbulence are discussed to understand the fundamental processes in a local reconnection layer both in space and laboratory plasmas. While the understanding of the global reconnection dynamics is less developed, notable findings have been made on this issue through detailed documentation of magnetic self-organization phenomena in fusion plasmas. Application of magnetic reconnection physics to astrophysical plasmas is also brie y discussed.

  1. Patterned Magnetic Nanostructures and Quantized Magnetic Disks

    E-Print Network [OSTI]

    -increasing demands in data storage and to new applications of magnetic devices in the field of sensors. NewPatterned Magnetic Nanostructures and Quantized Magnetic Disks STEPHEN Y. CHOU Invited Paper, opens up new opportunities for engineering innovative magnetic materials and devices, developing ultra

  2. TEST & MOTION SIMULATION SYSTEMSSERVOTEST Tailored Solutions For Your Servohydraulic

    E-Print Network [OSTI]

    TEST & MOTION SIMULATION SYSTEMSSERVOTEST SERVOTEST ACTUATORS Tailored Solutions For Your Servohydraulic Test And Motion Simulation System Requirements #12;TEST & MOTION SIMULATION SYSTEMSSERVOTEST qualified engineers · Founded in 1958 as a Consultancy to service the growing test market · International

  3. Efficient Cost Measures for Motion Compensation at Low Bit Rates

    E-Print Network [OSTI]

    Hoang, Dzung T.; Long, Philip M.; Vitter, Jeffrey Scott

    1996-01-01

    We present and compare methods for choosing motion vectors for block-based motion-compensated video coding. The primary focus is on videophone and video- conferencing applications, where low bit rates are neces- sary, where motion is usually limited...

  4. Simulation levels of detail for plant motion 

    E-Print Network [OSTI]

    Beaudoin, Jacob Michael

    2013-02-22

    that motion interactive [PCOI, DCFOI, EMF03]. A comparison of our method with some of these other methods is provided in section 7. 1. SLODs have come into prominence only in the last few years [Ber97, CF97]. They have sometimes taken other names ? Endo et... al. refer to them as levels of motion detail, or LOmDs [EMF03]. There have been a wide variety of applications for SLODs. These include rigid body dynamics and motion [CIF99, DO01, CAF01], simple collision detection and response [CH97, ODG*03...

  5. Ultra-wideband radar motion sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1994-11-01

    A motion sensor is based on ultra-wideband (UWB) radar. UWB radar range is determined by a pulse-echo interval. For motion detection, the sensors operate by staring at a fixed range and then sensing any change in the averaged radar reflectivity at that range. A sampling gate is opened at a fixed delay after the emission of a transmit pulse. The resultant sampling gate output is averaged over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion. 15 figs.

  6. Neutrinoless double beta decay mediated by the neutrino magnetic moment

    E-Print Network [OSTI]

    Marek Gó?d?; Wies?aw A. Kami?ski

    2014-11-07

    We present a new channel of the neutrinoless double beta decay. In this scenario neutrinos not only oscillate inside the nucleus but also interact with an external non-uniform magnetic field. We assume that the field rotates about the direction of motion of the neutrino and show, that for a certain speed of rotation the half-life of the $0\

  7. Neutrinoless double beta decay mediated by the neutrino magnetic moment

    E-Print Network [OSTI]

    Gó?d?, Marek

    2014-01-01

    We present a new channel of the neutrinoless double beta decay. In this scenario neutrinos not only oscillate inside the nucleus but also interact with an external non-uniform magnetic field. We assume that the field rotates about the direction of motion of the neutrino and show, that for a certain speed of rotation the half-life of the $0\

  8. ROTATING MOTIONS AND MODELING OF THE ERUPTING SOLAR POLAR-CROWN PROMINENCE ON 2010 DECEMBER 6

    SciTech Connect (OSTI)

    Su, Yingna; Van Ballegooijen, Adriaan

    2013-02-10

    A large polar-crown prominence composed of different segments spanning nearly the entire solar disk erupted on 2010 December 6. Prior to the eruption, the filament in the active region part split into two layers: a lower layer and an elevated layer. The eruption occurs in several episodes. Around 14:12 UT, the lower layer of the active region filament breaks apart: One part ejects toward the west, while the other part ejects toward the east, which leads to the explosive eruption of the eastern quiescent filament. During the early rise phase, part of the quiescent filament sheet displays strong rolling motion (observed by STEREO-B) in the clockwise direction (viewed from east to west) around the filament axis. This rolling motion appears to start from the border of the active region, then propagates toward the east. The Atmospheric Imaging Assembly (AIA) observes another type of rotating motion: In some other parts of the erupting quiescent prominence, the vertical threads turn horizontal, then turn upside down. The elevated active region filament does not erupt until 18:00 UT, when the erupting quiescent filament has already reached a very large height. We develop two simplified three-dimensional models that qualitatively reproduce the observed rolling and rotating motions. The prominence in the models is assumed to consist of a collection of discrete blobs that are tied to particular field lines of a helical flux rope. The observed rolling motion is reproduced by continuous twist injection into the flux rope in Model 1 from the active region side. Asymmetric reconnection induced by the asymmetric distribution of the magnetic fields on the two sides of the filament may cause the observed rolling motion. The rotating motion of the prominence threads observed by AIA is consistent with the removal of the field line dips in Model 2 from the top down during the eruption.

  9. Effects of Seismic Motion Incoherency on SSI and SSSI Responses...

    Office of Environmental Management (EM)

    Effects of Seismic Motion Incoherency on SSI and SSSI Responses of Nuclear Structures for Different Soil Site Conditions Effects of Seismic Motion Incoherency on SSI and SSSI...

  10. Department of Energy Files Motion to Withdraw Yucca Mountain...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Files Motion to Withdraw Yucca Mountain License Application Department of Energy Files Motion to Withdraw Yucca Mountain License Application March 3, 2010 -...

  11. ROCKING AND OVERTURNING RESPONSE OF RIGID BODIES TO EARTHQUAKE MOTIONS

    E-Print Network [OSTI]

    Aslam, M.

    2011-01-01

    Pendulum Structures During Earthquakes," Bulletin of theand Tsai, N.C. , "Simulated Earthquake Motions," CaliforniaResponse of Rigid Bodies to Earthquake Motions M. Aslam W.

  12. Generalized Sampling-Based Feedback Motion Planners 

    E-Print Network [OSTI]

    Kumar, Sandip

    2012-02-14

    states. In the deterministic robotics motion planning community, sampling based algorithms like probabilistic roadmaps (PRM) and rapidly exploring random trees (RRTs) have been successful in solving very high dimensional deterministic problem. However...

  13. Test particle motion in modified gravity theories

    E-Print Network [OSTI]

    Mahmood Roshan

    2013-02-05

    We derive the equations of motion of an electrically neutral test particle for modified gravity theories in which the covariant divergence of the ordinary matter energy-momentum tensor dose not vanish (i.e. $\

  14. On learning task-directed motion plans

    E-Print Network [OSTI]

    Finney, Sarah, 1974-

    2009-01-01

    Robotic motion planning is a hard problem for robots with more than just a few degrees of freedom. Modern probabilistic planners are able to solve many problems very quickly, but for difficult problems, they are still ...

  15. Influence of Motion Cueing on Helicopter Stabilization

    E-Print Network [OSTI]

    Influence of Motion Cueing on Helicopter Stabilization Daniel R. Berger, Cengiz Terzibas, and Heinrich H. Bülthoff Max Planck Institute for Biological Cybernetics, Tübingen, Germany Helicopters vestibular and somatosensory cues. To test this hypothesis, we measured helicopter hovering performance

  16. Week 14: Chapter 15 Oscillatory Motion

    E-Print Network [OSTI]

    conditions and observe the resultant motion When the spring is neither stretched nor compressed, the block About Restoring Force, 2 The block is at the equilibrium position x = 0 The spring is neither

  17. Information Fusion for Improved Motion Estimation 

    E-Print Network [OSTI]

    Peacock, Andrew M

    Motion Estimation is an important research field with many commercial applications including surveillance, navigation, robotics, and image compression. As a result, the field has received a great deal of attention and ...

  18. Slow motion responses of compliant offshore structures 

    E-Print Network [OSTI]

    Cao, Peimin

    1996-01-01

    An efficient method is developed to predict slow motion responses of slender compliant offshore structures in the unidirectional irregular waves and currents. The environmental loads are computed using the modified Morison equation based on slender...

  19. Properties of GRB Lightcurves from Magnetic Reconnection

    E-Print Network [OSTI]

    Beniamini, Paz

    2015-01-01

    The energy dissipation mechanism within Gamma ray bursts' (GRBs) ultra-relativistic outflows that drive the prompt $\\gamma$-ray emission remains uncertain. Two leading candidates are internal shocks and magnetic reconnection. While the emission from internal shocks has been extensively studied, that from reconnection still has few quantitative predictions. We study the prompt GRB emission from magnetic reconnection and compare its expected temporal and spectral properties to observations. The main difference from internal shocks is that for magnetic reconnection one expects relativistic bulk motions with a Lorentz factor of $\\Gamma'\\gtrsim$a few in the mean rest frame of the outflow - the comoving frame. We consider a thin spherical shell (or reconnection layer) expanding at a bulk Lorentz factor $\\Gamma\\gg 1$ in which the emitting material moves with $\\Gamma'$ in the comoving frame along this layer in two anti-parallel directions (e.g. of the reconnecting field lines). The resulting relativistic beaming of t...

  20. Diabaticity of nuclear motion: problems and perspectives

    SciTech Connect (OSTI)

    Nazarewicz, W [Joint Inst. for Heavy Ion Research, Oak Ridge, TN (United States)] [Joint Inst. for Heavy Ion Research, Oak Ridge, TN (United States)

    1992-12-31

    The assumption of adiabatic motion lies in foundations of many models of nuclear collective motion. To what extend can nuclear modes be treated adiabatically? Due to the richness and complexity of the nuclear many-body problem there is no unique answer to this question. The challenges of nuclear collective dynamics invite exciting interactions between several areas of physics such as nuclear structure, field theory, nonlinear dynamics, transport theory, and quantum chaos.

  1. Instrumentation for a multichord motional Stark effect diagnostic in KSTAR

    SciTech Connect (OSTI)

    Chung, J., E-mail: jinil@nfri.re.kr; Ko, J. [National Fusion Research Institute, Yuseong, Daejeon 305-333 (Korea, Republic of); De Bock, M. F. M.; Jaspers, R. J. E. [Eindhoven University of Technology, 5612 AZ, Eindhoven (Netherlands)

    2014-11-15

    The motional Stark effect (MSE) diagnostic is used to measure the radial magnetic pitch angle profile in neutral beam heated plasmas. This information is used to calculate the safety factor, q, with magnetic equilibrium reconstruction codes such as EFIT. The MSE diagnostic is important during active shaping of the q profile to optimize confinement and stability, and it has become a key diagnostic in high performance tokamaks. A multichord photo-elastic modulator (PEM) based MSE system is being developed for a real-time plasma current profile control in Korea Superconducting Tokamak Advanced Research (KSTAR). The PEM-based approach is a standard method that measures the polarization direction of a single Stark line with narrow tunable bandpass filters. A tangential view of the heating beam provides good spatial resolution of 1–3 cm, which provides an opportunity to install 25 spatial channels spanning the major radius from 1.74 m to 2.84 m. Application of real-time control is a long-term technical goal after commissioning the diagnostic in KSTAR, which is expected in 2015. In this paper, we describe the design of this newly-constructed multichord MSE diagnostic in KSTAR.

  2. Utilization of Recently Enhanced Simulation Tools and Empirical Ground Motion Databases to Improve Ground Motion Prediction Capabilities

    E-Print Network [OSTI]

    Khodavirdi, Khatereh

    2013-01-01

    Mo- tion Prediction Equations for Subduction Earthquakes. ”motion prediction equations for subduction earthquakes.motion prediction for interface subduction zone earthquakes

  3. Superconducting Magnet Division

    E-Print Network [OSTI]

    Gupta, Ramesh

    Superconducting Magnet Division Permanent Magnet Designs with Large Variations in Field Strength the residual field of the magnetized bricks by concentrating flux lines at the iron pole. Low Field Design Medium Field Design Superconducting Magnet Division Dipole and Quadrupole Magnets for RHIC e

  4. Superconducting magnet

    DOE Patents [OSTI]

    Satti, John A. (Naperville, IL)

    1980-01-01

    A superconducting magnet designed to produce magnetic flux densities of the order of 4 to 5 Webers per square meter is constructed by first forming a cable of a plurality of matrixed superconductor wires with each wire of the plurality insulated from each other one. The cable is shaped into a rectangular cross-section and is wound with tape in an open spiral to create cooling channels. Coils are wound in a calculated pattern in saddle shapes to produce desired fields, such as dipoles, quadrupoles, and the like. Wedges are inserted between adjacent cables as needed to maintain substantially radial placement of the long dimensions of cross sections of the cables. After winding, individual strands in each of the cables are brought out to terminals and are interconnected to place all of the strands in series and to maximize the propagation of a quench by alternating conduction from an inner layer to an outer layer and from top half to bottom half as often as possible. Individual layers are separated from others by spiraled aluminum spacers to facilitate cooling. The wound coil is wrapped with an epoxy tape that is cured by heat and then machined to an interference fit with an outer aluminum pipe which is then affixed securely to the assembled coil by heating it to make a shrink fit. In an alternate embodiment, one wire of the cable is made of copper or the like to be heated externally to propagate a quench.

  5. Evolution of reconnection along an arcade of magnetic loops

    E-Print Network [OSTI]

    Paolo C. Grigis; Arnold O. Benz

    2005-04-20

    RHESSI observations of a solar flare showing continuous motions of double hard X-ray sources interpreted as footpoints of magnetic loops are presented. The temporal evolution shows many distinct emission peaks of duration of some tens of seconds ('elementary flare bursts'). Elementary flare bursts have been interpreted as instabilities or oscillations of the reconnection process leading to an unsteady release of magnetic energy. These interpretations based on two-dimensional concepts cannot explain these observations, showing that the flare elements are displaced in a third dimension along the arcade. Therefore, the observed flare elements are not a modulation of the reconnection process, but originate as this process progresses along an arcade of magnetic loops. Contrary to previous reports, we find no correlation between footpoint motion and hard X-ray flux. This flare apparently contradicts the predictions of the standard translation invariant 2.5D reconnection models.

  6. Nanostructured magnetic materials

    E-Print Network [OSTI]

    Chan, Keith T.

    2011-01-01

    Magnetism and Magnetic Materials Conference, Atlanta, GA (Nanostructured Magnetic Materials by Keith T. Chan Doctor ofinduced by a Si-based material occurs at a Si/Ni interface

  7. Dynamics of Magnetized Vortex Tubes in the Solar Chromosphere

    E-Print Network [OSTI]

    Kitiashvili, I N; Mansour, N N; Wray, A A

    2012-01-01

    We use 3D radiative MHD simulations to investigate the formation and dynamics of small-scale (less than 0.5 Mm in diameter) vortex tubes spontaneously generated by turbulent convection in quiet-Sun regions with initially weak mean magnetic fields. The results show that the vortex tubes penetrate into the chromosphere and substantially affect the structure and dynamics of the solar atmosphere. The vortex tubes are mostly concentrated in intergranular lanes and are characterized by strong (near sonic) downflows and swirling motions that capture and twist magnetic field lines, forming magnetic flux tubes that expand with height and which attain magnetic field strengths ranging from 200 G in the chromosphere to more than 1 kG in the photosphere. We investigate in detail the physical properties of these vortex tubes, including thermodynamic properties, flow dynamics, and kinetic and current helicities, and conclude that magnetized vortex tubes provide an important path for energy and momentum transfer from the con...

  8. Brownian Dynamics of charged particles in a constant magnetic field

    E-Print Network [OSTI]

    Hou, L J; Piel, A; Shukla, P K

    2009-01-01

    Numerical algorithms are proposed for simulating the Brownian dynamics of charged particles in an external magnetic field, taking into account the Brownian motion of charged particles, damping effect and the effect of magnetic field self-consistently. Performance of these algorithms is tested in terms of their accuracy and long-time stability by using a three-dimensional Brownian oscillator model with constant magnetic field. Step-by-step recipes for implementing these algorithms are given in detail. It is expected that these algorithms can be directly used to study particle dynamics in various dispersed systems in the presence of a magnetic field, including polymer solutions, colloidal suspensions and, particularly complex (dusty) plasmas. The proposed algorithms can also be used as thermostat in the usual molecular dynamics simulation in the presence of magnetic field.

  9. Crustal motion in Indonesia from Global Positioning System measurements

    E-Print Network [OSTI]

    McCaffrey, Robert

    Crustal motion in Indonesia from Global Positioning System measurements Y. Bock,1 L. Prawirodirdjo: crustal motion, Indonesia tectonics, GPS, current plate motions, Southeast Asia Citation: Bock, Y., L, Crustal motion in Indonesia from Global Positioning System measurements, J. Geophys. Res., 108(B8), 2367

  10. Magnets and Power Supplies

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Up: APS Storage Ring Parameters Previous: Longitudinal bunch profile and Magnets and Power Supplies Dipole Magnets and Power Supplies Value Dipole Number 80+1 No. of power...

  11. SUPERCONDUCTING MAGNETIC ENERGY STORAGE

    E-Print Network [OSTI]

    Hassenzahl, W.

    2011-01-01

    Superconducting 30-MJ Energy Storage Coil", Proc. 19 80 ASC,Superconducting Magnetic Energy Storage Plant", IEEE Trans.SlIperconducting Magnetic Energy Storage Unit", in Advances

  12. 6.641 Electromagnetic Fields, Forces, and Motion, Spring 2003

    E-Print Network [OSTI]

    Zahn, Markus, 1946-

    Electric and magnetic quasistatic forms of Maxwell's equations applied to dielectric, conduction, and magnetization boundary value problems. Electromagnetic forces, force densities, and stress tensors, including magnetization ...

  13. Bulk equations of motion from CFT correlators

    E-Print Network [OSTI]

    Daniel Kabat; Gilad Lifschytz

    2015-07-27

    To O(1/N) we derive, purely from CFT data, the bulk equations of motion for interacting scalar fields and for scalars coupled to gauge fields and gravity. We first uplift CFT operators to mimic local AdS fields by imposing bulk microcausality. This requires adding an infinite tower of smeared higher-dimension double-trace operators to the CFT definition of a bulk field, with coefficients that we explicitly compute. By summing the contribution of the higher-dimension operators we derive the equations of motion satisfied by these uplifted CFT operators and show that we precisely recover the expected bulk equations of motion. We exhibit the freedom in the CFT construction which corresponds to bulk field redefinitions.

  14. Bulk equations of motion from CFT correlators

    E-Print Network [OSTI]

    Kabat, Daniel

    2015-01-01

    To O(1/N) we derive, purely from CFT data, the bulk equations of motion for interacting scalar fields and for scalars coupled to gauge fields and gravity. We first uplift CFT operators to mimic local AdS fields by imposing bulk microcausality. This requires adding an infinite tower of smeared higher-dimension double-trace operators to the CFT definition of a bulk field, with coefficients that we explicitly compute. By summing the contribution of the higher-dimension operators we derive the equations of motion satisfied by these uplifted CFT operators and show that we precisely recover the expected bulk equations of motion. We exhibit the freedom in the CFT construction which corresponds to bulk field redefinitions.

  15. Telescoping magnetic ball bar test gage

    DOE Patents [OSTI]

    Bryan, J.B.

    1982-03-15

    A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengagable servo drives which cannot be clutched out. Two gage balls are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit and a rigid member. One gage ball is secured by a magnetic socket knuckle assembly which fixes its center with respect to the machine being tested. The other gage ball is secured by another magnetic socket knuckle assembly which is engaged or held by the machine in such manner that the center of that ball is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball. As the moving ball executes its trajectory, changes in the radial distance between the centers of the two balls caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly actuated by the parallel reed flexure unit. Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball locations, thereby determining the accuracy of the machine.

  16. Electric-Magnetic Dualities in Gauge Theories

    E-Print Network [OSTI]

    Ho, Jun-Kai

    2015-01-01

    Electric-magnetic dualities are equivalence between strong and weak coupling constants. A standard way is to exchange electric and magnetic fields in the abelian gauge theory. We use three ways to perform electric-magnetic dualities in the case of the non-commutative $U(1)$ gauge theory. The first way is to use covariant field strengths to be the electric and magnetic fields. We find an invariant form of the equation of motion after performing the electric-magnetic duality. The second way is to use the Seiberg-Witten map to rewrite the non-commutative $U(1)$ gauge theory in terms of abelian field strength. The third way is that we use the large Neveu Schwarz-Neveu Schwarz (NS-NS) background limit (non-commutativity parameter only has one degree of freedom) to consider the non-commutative $U(1)$ gauge theory or D3-brane. In this limit, we introduce or dualize a new one-form gauge potential to get a D3-brane in a large Ramond-Ramond (R-R) background via field redefinition. We also use perturbation to study equi...

  17. Rigid and differential plasma crystal rotation induced by magnetic fields U. Konopka, D. Samsonov,* A. V. Ivlev,

    E-Print Network [OSTI]

    Goree, John

    Rigid and differential plasma crystal rotation induced by magnetic fields U. Konopka, D. Samsonov in the sheath of a radio-frequency discharge, rotate under the influence of a vertical magnetic field. Depending of motion. A simple analytical model is used to explain quali- tatively the mechanism of the observed

  18. Domain wall freezing in KDP-type ferroelectrics V.H. Schmidt*, G. Bohannan, D. Arbogast, G. Tuthill

    E-Print Network [OSTI]

    temperatures, the effect of this interaction is to "flatten" the wall, making it energe- tically unfavorable

  19. Quantum Dynamics of Spin Wave Propagation through Domain Walls S. YUAN, H. DE RAEDT and S. MIYASHITA1;2

    E-Print Network [OSTI]

    as a concept for a new generation of nonvolatile memory storage and logical devices.8) On the other hand nanostructures which is treated as a kind of soliton in a continuous medium. Such structure can be created of storing information or even performing logic functions, and to offer new types of electronics devices1

  20. Cosmic bubble and domain wall instabilities III: The role of oscillons in three-dimensional bubble collisions

    E-Print Network [OSTI]

    J. Richard Bond; Jonathan Braden; Laura Mersini-Houghton

    2015-06-09

    We study collisions between pairs of bubbles nucleated in an ambient false vacuum. For the first time, we include the effects of small initial (quantum) fluctuations around the instanton profiles describing the most likely initial bubble profile. Past studies of this problem neglect these fluctuations and work under the assumption that the collisions posess an exact SO(2,1) symmetry. We use three-dimensional lattice simulations to demonstrate that for double-well potentials, small initial perturbations to this symmetry can be amplified as the system evolves. Initially the amplification is well-described by linear perturbation theory around the SO(2,1) background, but the onset of strong nonlinearities amongst the fluctuations quickly leads to a drastic breaking of the original SO(2,1) symmetry and the production of oscillons in the collision region. We explore several single-field models, and we find it is hard to both realize inflation inside of a bubble and produce oscillons in a collision. Finally, we extend our results to a simple two-field model. The additional freedom allowed by the second field allows us to construct viable inflationary models that allow oscillon production in collisions. The breaking of the SO(2,1) symmetry allows for a new class of observational signatures from bubble collisions that do not posess azimuthal symmetry, including the production of gravitational waves which cannot be supported by an SO(2,1) spacetime.

  1. f{sub K}/f{sub {pi}} in full QCD with domain wall valence quarks (Journal

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of rare Kaonfor DirectSciTechConnectXOP:(Journal Article) |CapArticle) |

  2. Electron dynamics in parallel electric and magnetic fields

    E-Print Network [OSTI]

    Christian Bracher; Tobias Kramer; John B. Delos

    2005-10-13

    We examine the spatial distribution of electrons generated by a fixed energy point source in uniform, parallel electric and magnetic fields. This problem is simple enough to permit analytic quantum and semiclassical solution, and it harbors a rich set of features which find their interpretation in the unusual and interesting properties of the classical motion of the electrons: For instance, the number of interfering trajectories can be adjusted in this system, and the turning surfaces of classical motion contain a complex array of singularities. We perform a comprehensive analysis of both the semiclassical approximation and the quantum solution, and we make predictions that should serve as a guide for future photodetachment experiments.

  3. Magnetic Damping For Maglev

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhu, S.; Cai, Y.; Rote, D.M.; Chen, S.S.

    1998-01-01

    Magnetic damping is one of the important parameters that control the response and stability of maglev systems. An experimental study to measure magnetic damping directly is presented. A plate attached to a permanent magnet levitated on a rotating drum was tested to investigate the effect of various parameters, such as conductivity, gap, excitation frequency, and oscillation amplitude, on magnetic damping. The experimental technique is capable of measuring all of the magnetic damping coefficients, some of which cannot be measured indirectly.

  4. Robotic Motion The linear algebra of Canadarm

    E-Print Network [OSTI]

    Murty, Ram

    Robotic Motion The linear algebra of Canadarm #12;The robot arm simulation The movements of the robotic arm can be described using orthogonal matrices. #12;Six degrees of freedom The first segment the robotic arm to the position (x,y), we need to rotate the first arm by an angle and the second arm

  5. Video motion detection for physical security applications

    SciTech Connect (OSTI)

    Matter, J.C.

    1990-01-01

    Physical security specialists have been attracted to the concept of video motion detection for several years. Claimed potential advantages included additional benefit from existing video surveillance systems, automatic detection, improved performance compared to human observers, and cost effectiveness. In recent years significant advances in image processing dedicated hardware and image analysis algorithms and software have accelerated the successful application of video motion detection systems to a variety of physical security applications. Currently Sandia is developing several advanced systems that employ image processing techniques for a broader set of safeguards and security applications. TCATS (Target Cueing and Tracking System) uses a set of powerful, flexible, modular algorithms and software to alarm on purposeful target motion. Custom TCATS hardware optimized for perimeter security applications is currently being evaluated with video input. VISDTA (Video Imaging System for Detection, Tracking, and Assessment) uses some of the same TCATS algorithms and operates with a thermal imager input. In the scan mode, VISDTA detects changes in a scene from the previous image at a given scan point; in the stare mode, VISDTA detects purposeful motion similar to TCATS.

  6. Motion Planning for a Tethered Mobile Robot 

    E-Print Network [OSTI]

    HosseiniTeshnizi, Reza

    2015-08-12

    Recently there has been surge of research in motion planning for tethered robots. In this problem a planar robot is connected via a cable of limited length to a fixed point in R2. The configuration space in this problem is more complicated than...

  7. Chemistry in Motion: Tiny Synthetic Motors

    E-Print Network [OSTI]

    Peter H. Colberg; Shang Yik Reigh; Bryan Robertson; Raymond Kapral

    2014-11-03

    In this Account, we describe how synthetic motors that operate by self-diffusiophoresis make use of a self-generated concentration gradient to drive motor motion. A description of propulsion by self-diffusiophoresis is presented for Janus particle motors comprising catalytic and noncatalytic faces. The properties of the dynamics of chemically powered motors are illustrated by presenting the results of particle-based simulations of sphere-dimer motors constructed from linked catalytic and noncatalytic spheres. The geometries of both Janus and sphere-dimer motors with asymmetric catalytic activity support the formation of concentration gradients around the motors. Because directed motion can occur only when the system is not in equilibrium, the nature of the environment and the role it plays in motor dynamics are described. Rotational Brownian motion also acts to limit directed motion, and it has especially strong effects for very small motors. We address the following question: how small can motors be and still exhibit effects due to propulsion, even if only to enhance diffusion? Synthetic motors have the potential to transform the manner in which chemical dynamical processes are carried out for a wide range of applications.

  8. Clearance Based Path Optimization for Motion Planning

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Abstract Many motion planning techniques, like the probabilistic roadmap method (PRM), gen­ erate low] and humanoid robot planning [13]. A commonly used technique for planning paths is the Probabilistic Roadmap.1 Probabilistic Roadmap Method The probabilistic roadmap method consists of two phases: a construction and a query

  9. Strong-Motion Instrumentation Programs in Taiwan

    E-Print Network [OSTI]

    Wu, Yih-Min

    western Taiwan, with high- rise buildings as a consequence of developing economy, is vulnerable-Motion Accelerograph Array in Taiwan, Phase 1 (SMART-1 Array) SMART-1 Array was set up in Lotung in 1980 and closed and University of California, Berkeley. The SMART-1 Array consisted of a central site and accelerographs in three

  10. On the Topic of Motion Integrals 

    E-Print Network [OSTI]

    Bertinato, Christopher

    2013-04-02

    An integral of motion is a function of the states of a dynamical system that is constant along the system’s trajectories. Integrals are known for their utility as a means of reducing the dimension of a system, effectively leaving only one...

  11. Clearance Based Path Optimization for Motion Planning

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Abstract Many motion planning techniques, like the probabilistic roadmap method (PRM), gen- erate low] and humanoid robot planning [13]. A commonly used technique for planning paths is the Probabilistic Roadmap. 1.1 Probabilistic Roadmap Method The probabilistic roadmap method consists of two phases

  12. Canonical equations of ideal magnetic hydrodynamics

    SciTech Connect (OSTI)

    Gorskii, V.B.

    1987-07-01

    Ideal magnetohydrodynamics is used to consider a general class of adiabatic flow in magnetic liquids. Two invariants of the canonical equations of motion--Hamiltonian and Lagrangian--are determined in terms of the canonical variables by using the approximate variational formulations. The resulting model describes adiabatic three-dimensional flow of a nonviscous compressible liquid with ideal electric conductivity and zero heat conductivity. A Clebsch transformation is used to arrive at a form of the Lagrange-Cauchy integral for a vortex flow.

  13. Measurement and physical interpretation of the mean motion of turbulent density patterns detected by the BES system on MAST

    E-Print Network [OSTI]

    Ghim, Y -c; Dunai, D; Zoletnik, S; Bardoczi, L; Schekochihin, A A

    2012-01-01

    The mean motion of turbulent patterns detected by a two-dimensional (2D) beam emission spectroscopy (BES) diagnostic on the Mega Amp Spherical Tokamak (MAST) is determined using a cross-correlation time delay (CCTD) method. Statistical reliability of the method is studied by means of synthetic data analysis. The experimental measurements on MAST indicate that the apparent mean poloidal motion of the turbulent density patterns in the lab frame arises because the longest correlation direction of the patterns (parallel to the local background magnetic fields) is not parallel to the direction of the fastest mean plasma flows (usually toroidal when strong neutral beam injection is present). The experimental measurements are consistent with the mean motion of plasma being toroidal. The sum of all other contributions (mean poloidal plasma flow, phase velocity of the density patterns in the plasma frame, non-linear effects, etc.) to the apparent mean poloidal velocity of the density patterns is found to be negligible...

  14. Nanocomposite Magnets: Transformational Nanostructured Permanent Magnets

    SciTech Connect (OSTI)

    2010-10-01

    Broad Funding Opportunity Announcement Project: GE is using nanomaterials technology to develop advanced magnets that contain fewer rare earth materials than their predecessors. Nanomaterials technology involves manipulating matter at the atomic or molecular scale, which can represent a stumbling block for magnets because it is difficult to create a finely grained magnet at that scale. GE is developing bulk magnets with finely tuned structures using iron-based mixtures that contain 80% less rare earth materials than traditional magnets, which will reduce their overall cost. These magnets will enable further commercialization of HEVs, EVs, and wind turbine generators while enhancing U.S. competitiveness in industries that heavily utilize these alternatives to rare earth minerals.

  15. Comment on 'Geometric phase of the gyromotion for charged particles in a time-dependent magnetic field'[Phys. Plasmas 18, 072505 (2011)

    SciTech Connect (OSTI)

    Brizard, Alain J. [Department of Physics, Saint Michael's College, Colchester, Vermont 05439 (United States); Guillebon, Loiec de [Centre de Physique Theorique Aix-Marseille Universite, CNRS (UMR 7332), 13288 Marseille Cedex 09 (France)

    2012-09-15

    The geometric analysis of the gyromotion for charged particles in a time-dependent magnetic field by Liu and Qin [Phys. Plasmas 18, 072505 (2011)] is reformulated in terms of the spatial angles that represent the instantaneous orientation of the magnetic field. This new formulation, which includes the equation of motion for the pitch angle, clarifies the decomposition of the gyroangle-averaged equation of motion for the gyrophase into its dynamic and geometric contributions.

  16. PHYS 626 --Fundamentals of Plasma Physics --Section 6.4-6.5 1. Using the ideal MHD equation of motion, an energy equation can be derived. It is

    E-Print Network [OSTI]

    Ng, Chung-Sang

    ). The energy of the wave is propagating along ^z, with group velocity vg = VA ^z. 4. The other two modes of motion, an energy equation can be derived. It is simply the continuity equation of energy density, which is the sum of kinetic energy density mU2 /2, magnetic energy density B2 /2µ0, and the internal energy

  17. A magnetohydrodynamic model of the M87 jet. II. Self-consistent quad-shock jet model for optical relativistic motions and particle acceleration

    SciTech Connect (OSTI)

    Nakamura, Masanori

    2014-04-20

    We describe a new paradigm for understanding both relativistic motions and particle acceleration in the M87 jet: a magnetically dominated relativistic flow that naturally produces four relativistic magnetohydrodynamic (MHD) shocks (forward/reverse fast and slow modes). We apply this model to a set of optical super- and subluminal motions discovered by Biretta and coworkers with the Hubble Space Telescope during 1994-1998. The model concept consists of ejection of a single relativistic Poynting jet, which possesses a coherent helical (poloidal + toroidal) magnetic component, at the remarkably flaring point HST-1. We are able to reproduce quantitatively proper motions of components seen in the optical observations of HST-1 with the same model we used previously to describe similar features in radio very long baseline interferometry observations in 2005-2006. This indicates that the quad relativistic MHD shock model can be applied generally to recurring pairs of super/subluminal knots ejected from the upstream edge of the HST-1 complex as observed from radio to optical wavelengths, with forward/reverse fast-mode MHD shocks then responsible for observed moving features. Moreover, we identify such intrinsic properties as the shock compression ratio, degree of magnetization, and magnetic obliquity and show that they are suitable to mediate diffusive shock acceleration of relativistic particles via the first-order Fermi process. We suggest that relativistic MHD shocks in Poynting-flux-dominated helical jets may play a role in explaining observed emission and proper motions in many active galactic nuclei.

  18. Apparatus and method for reducing inductive coupling between levitation and drive coils within a magnetic propulsion system

    DOE Patents [OSTI]

    Post, Richard F. (Walnut Creek, CA)

    2001-01-01

    An apparatus and method is disclosed for reducing inductive coupling between levitation and drive coils within a magnetic levitation system. A pole array has a magnetic field. A levitation coil is positioned so that in response to motion of the magnetic field of the pole array a current is induced in the levitation coil. A first drive coil having a magnetic field coupled to drive the pole array also has a magnetic flux which induces a parasitic current in the levitation coil. A second drive coil having a magnetic field is positioned to attenuate the parasitic current in the levitation coil by canceling the magnetic flux of the first drive coil which induces the parasitic current. Steps in the method include generating a magnetic field with a pole array for levitating an object; inducing current in a levitation coil in response to motion of the magnetic field of the pole array; generating a magnetic field with a first drive coil for propelling the object; and generating a magnetic field with a second drive coil for attenuating effects of the magnetic field of the first drive coil on the current in the levitation coil.

  19. Exact Relativistic Magnetized halos around Rotating Disks

    E-Print Network [OSTI]

    Antonio C. Gutiérrez-Piñeres; Abraão J. S. Capistrano

    2015-05-15

    The exact relativistic treatment of a rotating disk surrounded by a magnetized material halo is presented. The features of the halo and disk are described by the distributional energy-momentum tensor of a general fluid in canonical form. All the relevant quantities and the metric and electromagnetic potentials are exactly determined by an arbitrary harmonic function only. For instance, the generalized Kuzmin-disk potential is used. The particular class of solutions obtained is asymptotically flat and satisfies all the energy conditions. Moreover, the motion of a charged particle on the halo is described. As far as we know, this is the first relativistic model describing analytically the magnetized halo of a rotating disk.

  20. Magnetic infrasound sensor

    DOE Patents [OSTI]

    Mueller, Fred M. (Los Alamos, NM); Bronisz, Lawrence (Los Alamos, NM); Grube, Holger (Los Alamos, NM); Nelson, David C. (Santa Fe, NM); Mace, Jonathan L. (Los Alamos, NM)

    2006-11-14

    A magnetic infrasound sensor is produced by constraining a permanent magnet inside a magnetic potential well above the surface of superconducting material. The magnetic infrasound sensor measures the position or movement of the permanent magnet within the magnetic potential well, and interprets the measurements. Infrasound sources can be located and characterized by combining the measurements from one or more infrasound sensors. The magnetic infrasound sensor can be tuned to match infrasound source types, resulting in better signal-to-noise ratio. The present invention can operate in frequency modulation mode to improve sensitivity and signal-to-noise ratio. In an alternate construction, the superconductor can be levitated over a magnet or magnets. The system can also be driven, so that time resolved perturbations are sensed, resulting in a frequency modulation version with improved sensitivity and signal-to-noise ratio.

  1. Magnetic switch coupling to synchronize magnetic modulators

    DOE Patents [OSTI]

    Reed, Kim W. (Albuquerque, NM); Kiekel, Paul (Albuquerque, NM)

    1999-01-01

    Apparatus for synchronizing the output pulses from a pair of magnetic switches. An electrically conductive loop is provided between the pair of switches with the loop having windlings about the core of each of the magnetic switches. The magnetic coupling created by the loop removes voltage and timing variations between the outputs of the two magnetic switches caused by any of a variety of factors. The only remaining variation is a very small fixed timing offset caused by the geometry and length of the loop itself.

  2. Magnetic switch coupling to synchronize magnetic modulators

    DOE Patents [OSTI]

    Reed, K.W.; Kiekel, P.

    1999-04-27

    Apparatus for synchronizing the output pulses from a pair of magnetic switches is disclosed. An electrically conductive loop is provided between the pair of switches with the loop having windings about the core of each of the magnetic switches. The magnetic coupling created by the loop removes voltage and timing variations between the outputs of the two magnetic switches caused by any of a variety of factors. The only remaining variation is a very small fixed timing offset caused by the geometry and length of the loop itself. 13 figs.

  3. A high spatial resolution Stokes polarimeter for motional Stark effect imaging

    SciTech Connect (OSTI)

    Thorman, Alex; Michael, Clive; Howard, John [Plasma Research Laboratory, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2013-06-15

    We describe an enhanced temporally switched interfero-polarimeter that has been successfully deployed for high spatial resolution motional Stark effect imaging on the KSTAR superconducting tokamak. The system utilizes dual switching ferroelectric liquid crystal waveplates to image the full Stokes vector of elliptically polarized and Doppler-shifted Stark-Zeeman Balmer-alpha emission from high energy neutral beams injected into the magnetized plasma. We describe the optical system and compare its performance against a Mueller matrix model that takes account of non-ideal performance of the switching ferro-electric liquid crystal waveplates and other polarizing components.

  4. Electric-Magnetic Struggle in QGP, Deconfinement and Baryons

    E-Print Network [OSTI]

    Edward Shuryak

    2007-09-13

    We argue that quite unusual properties of Quark-Gluon Plasma in the RHIC temperature domain $T=(1-2)T_c$ are consequences of the approximate equilibrium between electric and magnetic sectors reached above the deconfinement temperature. Already classical study of few body motion in a electric-magnetic plasma shows abnormally large scattering rate due to the so called ``magnetic bottle'' effect. Molecular dynamics simulation have found that equal mixture of electric and magnetic quasiparticles do produce plasmas of small viscosity and even smaller diffusion rate, comparable to what is needed to explain RHIC data and also to what follows from AdS/CFT. As a separate issue, we point out that right above $T_c$ there should be surviving s-wave baryons made of quarks ($N,\\Delta$), as well as adjoint objects, 3-gluon and 3-monopole chains (the latter being nothing else but ``calorons'' or finite-T instantons).

  5. Controlling Magnetism at the Nanoscale

    E-Print Network [OSTI]

    Wong, Jared

    2012-01-01

    157 A.2 Magnetism Unit Conversion148 A.1 Magnetism Unit ConversionA·m) Table A.1: Magnetism Unit Conversion Table Quantity A.1

  6. Beyond pixels : exploring new representations and applications for motion analysis

    E-Print Network [OSTI]

    Liu, Ce, Ph. D. Massachusetts Institute of Technology

    2009-01-01

    The focus of motion analysis has been on estimating a flow vector for every pixel by matching intensities. In my thesis, I will explore motion representations beyond the pixel level and new applications to which these ...

  7. Motion-to-Energy (M2Eâ?¢) Power Generation Technology

    ScienceCinema (OSTI)

    Idaho National Laboratory

    2010-01-08

    INL researchers developed M2E, a new technology that converts motion to energy. M2E uses an innovative, optimized microgenerator with power management circuitry that kinetically charges mobile batteries from natural motion such as walking. To learn more,

  8. Motion-to-Energy (M2E) Power Generation Technology

    ScienceCinema (OSTI)

    INL

    2009-09-01

    INL researchers developed M2E, a new technology that converts motion to energy. M2E uses an innovative, optimized microgenerator with power management circuitry that kinetically charges mobile batteries from natural motion such as walking.

  9. Stochastic Conformational Roadmaps for Computing Ensemble Properties of Molecular Motion

    E-Print Network [OSTI]

    Latombe, Jean-Claude

    Stochastic Conformational Roadmaps for Computing Ensemble Properties of Molecular Motion Mehmet intuition behind probabilistic roadmap planners for motion planning is that many collision-free paths stochas- tic conformational roadmap, whose nodes are randomly sampled molecule conformations. A roadmap

  10. Perception and processing of self-motion cues 

    E-Print Network [OSTI]

    Smith, Michael Thomas

    2013-11-28

    The capacity of animals to navigate through familiar or novel environments depends crucially on the integration of a disparate set of self motion cues. The study begins with one of the most simple, planar visual motion, ...

  11. The Duffing Oscillator And Linearization Techniques For Its Motion Constants 

    E-Print Network [OSTI]

    Rashdan, Mouath

    2014-01-16

    Analyzing the characteristics of higher order nonlinear dynamic systems is really difficult. This can involve giving solutions with respect to time. Motion constants are another way of studying the behavior of the dynamic system. If the motion...

  12. Production-Intent Lost-Motion Variable Valve Actuation Systems...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Production-Intent Lost-Motion Variable Valve Actuation Systems Production-Intent Lost-Motion Variable Valve Actuation Systems Variable valve actuation with onoff IEGR pre-bump is...

  13. Active dipole clusters: from helical motion to fission

    E-Print Network [OSTI]

    Andreas Kaiser; Katarina Popowa; Hartmut Löwen

    2015-05-29

    The structure of a finite particle cluster is typically determined by total energy minimization. Here we consider the case where a cluster of soft sphere dipoles becomes active, i.e. when the individual particles exhibit an additional self-propulsion along their dipole moments. We numerically solve the overdamped equations of motion for soft-sphere dipoles in a solvent. Starting from an initial metastable dipolar cluster, the self-propulsion generates a complex cluster dynamics. The final cluster state has in general a structure widely different to the initial one, the details depend on the model parameters and on the protocol of how the self-propulsion is turned on. The center-of-mass of the cluster moves on a helical path, the details of which are governed by the initial cluster magnetization. An instantaneous switch to a high self-propulsion leads to fission of the cluster. However, fission does not occur if the self-propulsion is increased slowly to high strengths. Our predictions can be verified through experiments with self-phoretic colloidal Janus-particles and for macroscopic self-propelled dipoles in a highly viscous solvent.

  14. Dynamical Objectivity in Quantum Brownian Motion

    E-Print Network [OSTI]

    J. Tuziemski; J. K. Korbicz

    2015-01-05

    We analyze one of the fundamental models of decoherence and quantum-to-classical transition---Quantum Brownian Motion, and show formation of a, so called, spectrum broadcast structure. As recently shown, this is a specific structure of multi-partite quantum states responsible for appearance of classical objective features in quantum mechanics. Working in the limit of a very massive central system and in a weak-coupling regime, we derive a surprising time-evolving, rather than time-asymptotic, spectrum broadcast structure, leading to perceived objectivity of a state of motion. We do it for realistic, noisy random environment, modeled as a thermal bath, and present some generalization to arbitrary single-mode Gaussian states. We study numerically the formation of the spectrum broadcast structure as a function of the temperature, showing its certain noise-robustness.

  15. An Alternative Approach to Elliptical Motion

    E-Print Network [OSTI]

    Mustafa Ozdemir

    2015-04-17

    Elliptical rotation is the motion of a point on an ellipse through some angle about a vector. The purpose of this paper is to examine the generation of elliptical rotations and to interpret the motion of a point on an elipsoid using elliptic inner product and elliptic vector product. To generate an elliptical rotation matrix, first we define an elliptical ortogonal matrix and an elliptical skew symmetric matrix using the associated inner product. Then we use elliptic versions of the famous Rodrigues, Cayley, and Householder methods to construct an elliptical rotation matrix. Finally, we define elliptic quaternions and generate an elliptical rotation matrix using those quaternions. Each method is proven and is provided with several numerical examples.

  16. Particle energization through time-periodic helical magnetic fields

    E-Print Network [OSTI]

    Mitra, Dhrubaditya; Dasgupta, Brahmananda; Niklasson, Eyvind; Ram, Abhay

    2013-01-01

    We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with $A=B=C=1$ are chaotic, and we show that the motion of a charged particle in such a field is also chaotic at late time with positive Lyapunov exponent. We further show that in time-periodic (frequency $\\omega$) ABC fields the kinetic energy of a charged particle can increase indefinitely with time. At late times the mean kinetic energy grows as a power law in time with exponent $\\xi$ that approaches unity. For an initial distribution of particles, whose kinetic energy is uniformly distributed within some interval, the PDF of kinetic energy is, at late time, close to a Gaussian but with steeper tails.

  17. Particle energization through time-periodic helical magnetic fields

    E-Print Network [OSTI]

    Dhrubaditya Mitra; Axel Brandenburg; Brahmananda Dasgupta; Eyvind Niklasson; Abhay Ram

    2014-04-30

    We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with coefficients $A=B=C=1$ are chaotic, and we show that the motion of a charged particle in such a field is also chaotic at late times with positive Lyapunov exponent. We further show that in time-periodic ABC fields, the kinetic energy of a charged particle can increase indefinitely with time. At late times the mean kinetic energy grows as a power law in time with an exponent that approaches unity. For an initial distribution of particles, whose kinetic energy is uniformly distributed within some interval, the PDF of kinetic energy is, at late times, close to a Gaussian but with steeper tails.

  18. General Nth order integrals of the motion

    E-Print Network [OSTI]

    S. Post; P. Winternitz

    2015-02-11

    The general form of an integral of motion that is a polynomial of order N in the momenta is presented for a Hamiltonian system in two-dimensional Euclidean space. The classical and the quantum cases are treated separately, emphasizing both the similarities and the differences between the two. The main application will be to study Nth order superintegrable systems that allow separation of variables in the Hamilton-Jacobi and Schr\\"odinger equations, respectively.

  19. Compression of ground-motion data

    SciTech Connect (OSTI)

    Long, J.W.

    1981-04-01

    Ground motion data has been recorded for many years at Nevada Test Site and is now stored on thousands of digital tapes. The recording format is very inefficient in terms of space on tape. This report outlines a method to compress the data onto a few hundred tapes while maintaining the accuracy of the recording and allowing restoration of any file to the original format for future use. For future digitizing a more efficient format is described and suggested.

  20. A Note on Gravitational Brownian Motion

    E-Print Network [OSTI]

    David Merritt

    2004-05-19

    Chandrasekhar's theory of stellar encounters predicts a dependence of the Brownian motion of a massive particle on the velocity distribution of the perturbing stars. One consequence is that the expectation value of the massive object's kinetic energy can be different from that of the perturbers. This effect is shown to be modest however, and substantially smaller than claimed in a recent study based on a more approximate treatment of the encounter equations.

  1. Video looping of human cyclic motion 

    E-Print Network [OSTI]

    Choi, Hye Mee

    2004-09-30

    Library . ................ 30 IV.2.1. Walk . . . ....................... 34 IV.2.2. Run . . . . ....................... 37 IV.2.3. Hop and Jump . . . . . ................ 39 IV.2.4. Carrying a Heavy Object ................ 43 IV.3. Compositing Multiple... in Motion. Plate 115: Dog walk. [18] ... 4 4 Marey?s fusil photographique. [1] ..................... 6 5 Marey?s black costume for geometric chronophotography, 1884. [1] ... 6 6 Etienne-Jules Marey, (a) Joinville soldier walking, 1883. (b) Joinville soldier...

  2. ForPeerReview SMC Framework in Motion Control Systems

    E-Print Network [OSTI]

    Yanikoglu, Berrin

    ForPeerReview SMC Framework in Motion Control Systems Journal: International Journal of Adaptive, Mechatronics Keywords: Motion Control, Sliding Mode Control, Bilateral Control , Interconnected Systems http acsauth.cls [Version: 2002/11/11 v1.00] SMC Framework in Motion Control Systems A. S¸abanovi¸c Sabanci

  3. Ground motions and its effects in accelerator design

    SciTech Connect (OSTI)

    Fischer, G.E.

    1984-07-01

    This lecture includes a discussion of types of motion, frequencies of interest, measurements at SLAC, some general comments regarding local sources of ground motion at SLAC, and steps that can be taken to minimize the effects of ground motion on accelerators. (GHT)

  4. FIFTY YEARS OF GROUND-MOTION MODELS John Douglas1

    E-Print Network [OSTI]

    model for the prediction of earthquake ground motions accounting for both magnitude and distance called: ground-motion models or ground- motion prediction equations (GMPEs), but originally were referred a month and at the last count the total number of equations for the prediction of peak ground acceleration

  5. VINETA II: A linear magnetic reconnection experiment

    SciTech Connect (OSTI)

    Bohlin, H. Von Stechow, A.; Rahbarnia, K.; Grulke, O.; Klinger, T.; Ernst-Moritz-Arndt University, Domstr. 11, 17489 Greifswald

    2014-02-15

    A linear experiment dedicated to the study of driven magnetic reconnection is presented. The new device (VINETA II) is suitable for investigating both collisional and near collisionless reconnection. Reconnection is achieved by externally driving magnetic field lines towards an X-point, inducing a current in the background plasma which consequently modifies the magnetic field topology. Owing to the open field line configuration of the experiment, the current is limited by the axial sheath boundary conditions. A plasma gun is used as an additional electron source in order to counterbalance the charge separation effects and supply the required current. Two drive methods are used in the device. First, an oscillating current through two parallel conductors drive the reconnection. Second, a stationary X-point topology is formed by the parallel conductors, and the drive is achieved by an oscillating current through a third conductor. In the first setup, the magnetic field of the axial plasma current dominates the field topology near the X-point throughout most of the drive. The second setup allows for the amplitude of the plasma current as well as the motion of the flux to be set independently of the X-point topology of the parallel conductors.

  6. Electro-Mechanical Resonant Magnetic Field Sensor

    E-Print Network [OSTI]

    Temnykh, A B; Temnykh, Alexander B.; Lovelace, Richard V. E.

    2002-01-01

    We describe a new type of magnetic field sensor which is termed an Electro-Mechanical Resonant Sensor (EMRS). The key part of this sensor is a small conductive elastic element with low damping rate and therefore a high Q fundamental mode of frequency $f_1$. An AC current is driven through the elastic element which, in the presence of a magnetic field, causes an AC force on the element. When the frequency of the AC current matches the resonant frequency of the element, maximum vibration of the element occurs and this can be measured precisely by optical means. We have built and tested a model sensor of this type using for the elastic element a length of copper wire of diameter 0.030 mm formed into a loop shape. The wire motion was measured using a light emitting diode photo-transistor assembly. This sensor demonstrated a sensitivity better than 0.001G for an applied magnetic field of $ \\sim 1$G and a good selectivity for the magnetic field direction. The sensitivity can be easily improved by a factor of $\\sim ...

  7. Motion in alternative theories of gravity

    E-Print Network [OSTI]

    Gilles Esposito-Farese

    2009-05-15

    Although general relativity (GR) passes all present experimental tests with flying colors, it remains important to study alternative theories of gravity for several theoretical and phenomenological reasons that we recall in these lecture notes. The various possible ways of modifying GR are presented, and we notably show that the motion of massive bodies may be changed even if one assumes that matter is minimally coupled to the metric as in GR. This is illustrated with the particular case of scalar-tensor theories of gravity, whose Fokker action is discussed, and we also mention the consequences of the no-hair theorem on the motion of black holes. The finite size of the bodies modifies their motion with respect to pointlike particles, and we give a simple argument showing that the corresponding effects are generically much larger in alternative theories than in GR. We also discuss possible modifications of Newtonian dynamics (MOND) at large distances, which have been proposed to avoid the dark matter hypothesis. We underline that all the previous classes of alternatives to GR may a priori be used to predict such a phenomenology, but that they generically involve several theoretical and experimental difficulties.

  8. Magnetic Graphene Nanohole Superlattices

    E-Print Network [OSTI]

    Yu, Decai; Liu, Miao; Liu, Wei; Liu, Feng

    2008-01-01

    We investigate the magnetic properties of nano-holes (NHs) patterned in graphene using first principles calculations. We show that superlattices consisting of a periodic array of NHs form a new family of 2D crystalline "bulk" magnets whose collective magnetic behavior is governed by inter-NH spin-spin interaction. They exhibit long-range magnetic order well above room temperature. Furthermore, magnetic semiconductors can be made by doping magnetic NHs into semiconducting NH superlattices. Our findings offer a new material system for fundamental studies of spin-spin interaction and magnetic ordering in low dimensions, and open up the exciting opportunities of making engineered magnetic materials for storage media and spintronics applications.

  9. Magnetic assisted statistical assembly

    E-Print Network [OSTI]

    Cheng, Diana I

    2008-01-01

    The objective of this thesis is to develop a process using magnetic forces to assemble micro-components into recesses on silicon based integrated circuits. Patterned SmCo magnetic thin films at the bottom of recesses are ...

  10. Electric-Magnetic Dualities in Gauge Theories

    E-Print Network [OSTI]

    Jun-Kai Ho; Chen-Te Ma

    2015-07-28

    Electric-magnetic dualities are equivalence between strong and weak coupling constants. A standard way is to exchange electric and magnetic fields in the abelian gauge theory. We use three ways to perform electric-magnetic dualities in the case of the non-commutative $U(1)$ gauge theory. The first way is to use covariant field strengths to be the electric and magnetic fields. We find an invariant form of the equation of motion after performing the electric-magnetic duality. The second way is to use the Seiberg-Witten map to rewrite the non-commutative $U(1)$ gauge theory in terms of abelian field strength. The third way is that we use the large Neveu Schwarz-Neveu Schwarz (NS-NS) background limit (non-commutativity parameter only has one degree of freedom) to consider the non-commutative $U(1)$ gauge theory or D3-brane. In this limit, we introduce or dualize a new one-form gauge potential to get a D3-brane in a large Ramond-Ramond (R-R) background via field redefinition. We also use perturbation to study equivalence between two D3-brane theories. Comparison on three methods in the non-commutative $U(1)$ gauge theory gives different physical implications. This comparison reflects differences between the non-abelian and non-commutative gauge theories in the electric-magnetic dualities. For a complete study, we also extend our studies to the simplest abelian and non-abelian $p$-form gauge theories, and a non-commutative theory with the non-abelian structure.

  11. Management of Respiratory Motion in Extracorporeal High-Intensity Focused Ultrasound Treatment in Upper Abdominal Organs: Current Status and Perspectives

    SciTech Connect (OSTI)

    Muller, A., E-mail: arnaud.muller@chu-lyon.fr [Centre Hospitalier Lyon Sud, Service de Radiologie, Hospices Civils de Lyon (France); Petrusca, L.; Auboiroux, V. [University of Geneva, Department of Radiology, Faculty of Medicine (Switzerland)] [University of Geneva, Department of Radiology, Faculty of Medicine (Switzerland); Valette, P. J. [Centre Hospitalier Lyon Sud, Service de Radiologie, Hospices Civils de Lyon (France)] [Centre Hospitalier Lyon Sud, Service de Radiologie, Hospices Civils de Lyon (France); Salomir, R. [University of Geneva, Department of Radiology, Faculty of Medicine (Switzerland)] [University of Geneva, Department of Radiology, Faculty of Medicine (Switzerland); Cotton, F. [Centre Hospitalier Lyon Sud, Service de Radiologie, Hospices Civils de Lyon (France)] [Centre Hospitalier Lyon Sud, Service de Radiologie, Hospices Civils de Lyon (France)

    2013-12-15

    Extracorporeal high-intensity focused ultrasound (HIFU) is a minimally invasive therapy considered with increased interest for the ablation of small tumors in deeply located organs while sparing surrounding critical tissues. A multitude of preclinical and clinical studies have showed the feasibility of the method; however, concurrently they showed several obstacles, among which the management of respiratory motion of abdominal organs is at the forefront. The aim of this review is to describe the different methods that have been proposed for managing respiratory motion and to identify their advantages and weaknesses. First, we specify the characteristics of respiratory motion for the liver, kidneys, and pancreas and the problems it causes during HIFU planning, treatment, and monitoring. Second, we make an inventory of the preclinical and clinical approaches used to overcome the problem of organ motion. Third, we analyze their respective benefits and drawbacks to identify the remaining physical, technological, and clinical challenges. We thereby consider the outlook of motion compensation techniques and those that would be the most suitable for clinical use, particularly under magnetic resonance thermometry monitoring.

  12. Rotating superconductor magnet for producing rotating lobed magnetic field lines

    DOE Patents [OSTI]

    Hilal, Sadek K. (Englewood Cliffs, NJ); Sampson, William B. (Bellport, NY); Leonard, Edward F. (Leonia, NJ)

    1978-01-01

    This invention provides a rotating superconductor magnet for producing a rotating lobed magnetic field, comprising a cryostat; a superconducting magnet in the cryostat having a collar for producing a lobed magnetic field having oppositely directed adjacent field lines; rotatable support means for selectively rotating the superconductor magnet; and means for energizing the superconductor magnet.

  13. Magnetic Fields Analogous to electric field, a magnet

    E-Print Network [OSTI]

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

    Magnetic Fields Analogous to electric field, a magnet produces a magnetic field, B Set up a B field two ways: Moving electrically charged particles Current in a wire Intrinsic magnetic field Basic) Opposite magnetic poles attract like magnetic poles repel #12;Like the electric field lines

  14. Noble gas magnetic resonator

    DOE Patents [OSTI]

    Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert

    2014-04-15

    Precise measurements of a precessional rate of noble gas in a magnetic field is obtained by constraining the time averaged direction of the spins of a stimulating alkali gas to lie in a plane transverse to the magnetic field. In this way, the magnetic field of the alkali gas does not provide a net contribution to the precessional rate of the noble gas.

  15. Magnetic nanohole superlattices

    DOE Patents [OSTI]

    Liu, Feng

    2013-05-14

    A magnetic material is disclosed including a two-dimensional array of carbon atoms and a two-dimensional array of nanoholes patterned in the two-dimensional array of carbon atoms. The magnetic material has long-range magnetic ordering at a temperature below a critical temperature Tc.

  16. Atomic Motion in an Optical Standing Wave 40 Chapter 2. Atomic Motion in an Optical Standing Wave

    E-Print Network [OSTI]

    Steck, Daniel A.

    Chapter 2 Atomic Motion in an Optical Standing Wave 39 #12;40 Chapter 2. Atomic Motion in an Optical Standing Wave 2.1 Overview In this chapter we will motivate the experiments in this dissertation by considering the basic setup common to all of the experiments: the motion of an atom in a standing wave of far

  17. Magnetically attached sputter targets

    DOE Patents [OSTI]

    Makowiecki, D.M.; McKernan, M.A.

    1994-02-15

    An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material is described. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly. 11 figures.

  18. Systematic Microwave Source Motions along Flare-arcade Observed by Nobeyama Radioheliograph and AIA/SDO

    E-Print Network [OSTI]

    Kim, Sujin; Masuda, Satoshi

    2013-01-01

    We found systematic microwave source motions along a flare-arcade using Nobeyama Radioheliograph (NoRH) 17 GHz images. The motions were associated with a X-class disk flare which occurred on 15th February 2011. For this study, we also used EUV images from Atmospheric Imaging Assembly (AIA) and magnetograms from Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory, and multi-channel microwave data from Nobeyama Radiopolarimeters (NoRP) and Korean Solar Radio Burst Locator (KSRBL). We traced centroids of the microwave source observed by NoRH 17 GHz during the flare and found two episodes of the motion with several facts: 1) The microwave source moved systematically along the flare-arcade, which was observed by the AIA 94 A in a direction parallel to the neutral line. 2) The period of each episode was 5 min and 14 min, respectively. 3) Estimated parallel speed was 34 km/s for the first episode and 22 km/s for the second episode. The spectral slope of microwave flux above 10 GHz obtained by N...

  19. The chiral magnetic nanomotors

    E-Print Network [OSTI]

    Morozov, Konstantin I

    2013-01-01

    Propulsion of the chiral magnetic nanomotors powered by a rotating magnetic field is in the focus of the modern biomedical applications. This technology relies on strong interaction of dynamic and magnetic degrees of freedom of the system. Here we study in detail various experimentally observed regimes of the helical nanomotor orientation and propulsion depending on the actuation frequency, and establish the relation of these two properties with remanent magnetization and geometry of the helical nanomotors. The theoretical predictions for the transition between the regimes and nanomotor orientation and propulsion speed are in excellent agreement with available experimental data. The proposed theory offers a few simple guidelines towards the optimal design of the magnetic nanomotors. In particular, efficient nanomotors should be fabricated of hard magnetics, e.g., cobalt, magnetized transversally and have the geometry of a normal helix with a helical angle of 35-45 degrees.

  20. Particle Capture Efficiency in a Multi-Wire Model for High Gradient Magnetic Separation

    E-Print Network [OSTI]

    Eisenträger, Almut; Griffiths, Ian M

    2014-01-01

    High gradient magnetic separation (HGMS) is an efficient way to remove magnetic and paramagnetic particles, such as heavy metals, from waste water. As the suspension flows through a magnetized filter mesh, high magnetic gradients around the wires attract and capture the particles, removing them from the fluid. We model such a system by considering the motion of a paramagnetic tracer particle through a periodic array of magnetized cylinders. We show that there is a critical Mason number (ratio of viscous to magnetic forces) below which the particle is captured irrespective of its initial position in the array. Above this threshold, particle capture is only partially successful and depends on the particle's entry position. We determine the relationship between the critical Mason number and the system geometry using numerical and asymptotic calculations. If a capture efficiency below 100% is sufficient, our results demonstrate how operating the HGMS system above the critical Mason number but with multiple separa...

  1. Error Reduction for Weigh-In-Motion

    SciTech Connect (OSTI)

    Hively, Lee M; Abercrombie, Robert K; Scudiere, Matthew B; Sheldon, Frederick T

    2009-01-01

    Federal and State agencies need certifiable vehicle weights for various applications, such as highway inspections, border security, check points, and port entries. ORNL weigh-in-motion (WIM) technology was previously unable to provide certifiable weights, due to natural oscillations, such as vehicle bouncing and rocking. Recent ORNL work demonstrated a novel filter to remove these oscillations. This work shows further filtering improvements to enable certifiable weight measurements (error < 0.1%) for a higher traffic volume with less effort (elimination of redundant weighing).

  2. Quantum Brownian motion model for stock markets

    E-Print Network [OSTI]

    Meng, Xiangyi; Guo, Hong

    2014-01-01

    We investigate the relevance between quantum open systems and stock markets. A Quantum Brownian motion model is proposed for studying the interaction between the Brownian system and the reservoir, i.e., the stock index and the entire stock market. Based on the model, we investigate the Shanghai Stock Exchange of China from perspective of quantum statistics, and thereby examine the behaviors of the stock index violating the efficient market hypothesis, such as fat-tail phenomena and non-Markovian features. Our interdisciplinary works thus help to discovery the underlying quantum characteristics of stock markets and develop new research fields of econophysics.

  3. Quantum potential energy as concealed motion

    E-Print Network [OSTI]

    Peter Holland

    2014-11-13

    It is known that the Schroedinger equation may be derived from a hydrodynamic model in which the Lagrangian position coordinates of a continuum of particles represent the quantum state. Using Routh\\s method of ignorable coordinates it is shown that the quantum potential energy of particle interaction that represents quantum effects in this model may be regarded as the kinetic energy of additional concealed freedoms. The method brings an alternative perspective to Planck\\s constant, which plays the role of a hidden variable, and to the canonical quantization procedure, since what is termed kinetic energy in quantum mechanics may be regarded literally as energy due to motion.

  4. Blue Motion Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformationBio-GasIllinois: EnergyHills, Connecticut: EnergyMotion Energy

  5. Ocean Motion International LLC | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsourceII Jump to:Information 3rd|Northfork ElectricName01988) | OpenThe NeedlesMotion

  6. Formation of Moving Magnetic Features and Penumbral Magnetic Fields with Hinode/SOT

    E-Print Network [OSTI]

    Masahito Kubo; Kiyoshi Ichimoto; Toshifumi Shimizu; Saku Tsuneta; Yoshinori Suematsu; Yukio Katsukawa; Shin'ichi Nagata; Theodore D Tarbell; Richard A Shine; Alan M Title; Zoe A Frank; Bruce W Lites; David Elmore

    2007-09-12

    Vector magnetic fields of moving magnetic features (MMFs) are well observed with the Solar Optical Telescope (SOT) aboard the Hinode satellite. We focus on the evolution of three MMFs with the SOT in this study. We found that an MMF having relatively vertical fields with polarity same as the sunspot is detached from the penumbra around the granules appeared in the outer penumbra. This suggests that granular motions in the outer penumbra are responsible for the disintegration of the sunspot. Two MMFs with polarity opposite to the sunspot are located around the outer edge of horizontal fields extending from the penumbra. This is an evidence that the MMFs with polarity opposite to the sunspot are prolongation of penumbral horizontal fields. Radshifts larger than sonic velocity in the photosphere are detected for some of the MMFs with polarity opposite to the sunspot.

  7. Non-Fourier Motion in The Fourier Spectrum Steven S. Beauchemin

    E-Print Network [OSTI]

    Beauchemin, Steven S.

    Non-Fourier Motion in The Fourier Spectrum Steven S. Beauchemin GRASP Laboratory Department, image motion analysis in the fre- quency domain is performed according to the Motion From Fourier Coe- Fourier motion. This type of motion includes phenom- ena relevant to motion analysis such as translucency

  8. Diaphragm as an anatomic surrogate for lung tumor motion

    E-Print Network [OSTI]

    Cervino, Laura I; Sandhu, Ajay; Jiang, Steve B

    2009-01-01

    Lung tumor motion due to respiration poses a challenge in the application of modern three-dimensional conformal radiotherapy. Direct tracking of the lung tumor during radiation therapy is very difficult without implanted fiducial markers. Indirect tracking relies on the correlation of the tumor's motion and the surrogate's motion. The present paper presents an analysis of the correlation between the tumor motion and the diaphragm motion in order to evaluate the potential use of diaphragm as a surrogate for tumor motion. We have analyzed the correlation between diaphragm motion and superior-inferior lung tumor motion in 32 fluoroscopic image sequences from 10 lung cancer patients. A simple linear model and a more complex linear model that accounts for phase delays between the two motions have been used. Results show that the diaphragm is a good surrogate for tumor motion prediction for most patients, resulting in an average correlation factor of 0.94 and 0.98 with each model respectively. The model that accoun...

  9. Anisotropic Matter in Cosmology: Locally Rotationally Symmetric Bianchi $I$ and $VII_o$ Models

    E-Print Network [OSTI]

    Sloan, David

    2016-01-01

    We examine the behaviour of homogeneous, anisotropic space-times, specifically the locally rotationally symmetric Bianchi types $I$ and $VII_o$ in the presence of anisotropic matter. By finding an appropriate constant of the motion, and transforming the equations of motion we are able to provide exact solutions in the presence perfect fluids with anisotropic pressures. The solution space covers matter consisting of a single perfect fluid which satisfies the weak energy condition and is rich enough to contain solutions which exhibit behaviour which is qualitatively distinct from the isotropic sector. Thus we find that there is more `matter that matters' close to a homogeneous singularity than the usual stiff fluid. Example metrics are given for cosmologies whose matter sources are magnetic fields, relativistic particles, cosmic strings and domain walls.

  10. Motion Measurement for Synthetic Aperture Radar.

    SciTech Connect (OSTI)

    Doerry, Armin W.

    2015-01-01

    Synthetic Aperture Radar (SAR) measures radar soundings from a set of locations typically along the flight path of a radar platform vehicle. Optimal focusing requires precise knowledge of the sounding source locations in 3 - D space with respect to the target scene. Even data driven focusing techniques (i.e. autofocus) requires some degree of initial fidelity in the measurements of the motion of the radar. These requirements may be quite stringent especially for fine resolution, long ranges, and low velocities. The principal instrument for measuring motion is typically an Inertial Measurement Unit (IMU), but these instruments have inherent limi ted precision and accuracy. The question is %22How good does an IMU need to be for a SAR across its performance space?%22 This report analytically relates IMU specifications to parametric requirements for SAR. - 4 - Acknowledgements Th e preparation of this report is the result of a n unfunded research and development activity . Although this report is an independent effort, it draws heavily from limited - release documentation generated under a CRADA with General Atomics - Aeronautical System, Inc. (GA - ASI), and under the Joint DoD/DOE Munitions Program Memorandum of Understanding. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of En ergy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

  11. Computational Biomechanics, Stochastic Motion and Team Sports

    E-Print Network [OSTI]

    Grimpampi, E; Sacripanti, A

    2008-01-01

    The objective of the present study is to present a computational model of the motion of a single athlete in a team and to compare the resulting trajectory with experimental data obtained in the field during competitions by match analysis software. To this purpose, some results related to a paths ensemble of a single player are discussed. Between each interaction it is assumed that he follows a straight line and his motion is characterized by viscous, pushing and pedestrian like force. A random force is supposed to influence only the trajectory direction after each interaction. Furthermore it is assumed that the time step between each interaction is a random variable belonging to a Gaussian distribution. The main criteria is a selection of a function correlated to the strategy of the player, around which, in a necessarily randomly way, a tactic function should be added. The strategy depends on the players role: for the numerical simulations in this paper, a forward player was selected, with the average target ...

  12. Journal of Biomechanics 40 (2007) 437444 Quantifying biomechanical motion using Procrustes motion analysis

    E-Print Network [OSTI]

    Collins, Robert T.

    2007-01-01

    , IA 50011-2274, USA c Human Computer Interaction Program, Iowa State University, Ames, IA 50011 is a central focus of many studies in biology, anthropology, biomechanics, and ergonomics. However, while a multivariate data space, representing a specific motion. By evaluating the size, shape, and orientation

  13. KINEMATIC FAST DYNAMO PROBLEMS Stars and planets possess magnetic elds that permanently change. Earth, for

    E-Print Network [OSTI]

    Khesin, Boris A.

    CHAPTER V KINEMATIC FAST DYNAMO PROBLEMS Stars and planets possess magnetic elds that permanently that the time pattern of the switches forms a Cantor-type set on the time scale (see AnS]). The mechanism the subject of dynamo theory. Kinematic dynamo theory studies what kind of uid motion can induce exponential

  14. STATISTICAL PROPERTIES OF THE EVOLUTION OF SOLAR MAGNETIC FIELDS Loukas Vlahos #

    E-Print Network [OSTI]

    Vlahos, Loukas

    effects, such as the Coriolis force, magnetic tension, drag and large scale convection motion. The lack the observed activity at the photo­ sphere, chromosphere, corona and interplanetary space. Key words to the surface through buoyant forces. During their buoyant rise, flux tubes are influenced by several physical

  15. Morphology of the Small-Animal Lung Using Magnetic Resonance Microscopy

    E-Print Network [OSTI]

    Morphology of the Small-Animal Lung Using Magnetic Resonance Microscopy Laurence W. Hedlund and G motion control and animal support, the lungs of the live, small animal can be imaged. Although in vivo He, it is possible to image the tissue and gas compartments of the lung. This capability

  16. Pulsed Gradient Spin Echo Nuclear Magnetic Resonance Imaging of Diffusion in Granular Flow

    SciTech Connect (OSTI)

    Seymour, Joseph D.; Caprihan, Arvind; Altobelli, Stephen A.; Fukushima, Eiichi

    2000-01-10

    We derive the formalism to obtain spatial distributions of collisional correlation times for macroscopic particles undergoing granular flow from pulsed gradient spin echo nuclear magnetic resonance diffusion data. This is demonstrated with an example of axial motion in the shear flow regime of a 3D granular flow in a horizontal rotating cylinder at one rotation rate. (c) 2000 The American Physical Society.

  17. Dynamics of an electron confined to a "hybrid plane" and interacting with a magnetic field

    E-Print Network [OSTI]

    Raffaele Carlone; Pavel Exner

    2010-12-13

    We discuss spectral and resonance properties of a Hamiltonian describing motion of an electron moving on a "hybrid surface" consisting on a halfline attached by its endpoints to a plane under influence of a constant magnetic field which interacts with its spin through a Rashba-type term.

  18. USING RUNNING DIFFERENCE IMAGES TO TRACK PROPER MOTIONS OF XUV CORONAL INTENSITY ON THE SUN

    SciTech Connect (OSTI)

    Sheeley, N. R. Jr.; Warren, H. P.; Lee, J. E-mail: harry.warren@nrl.navy.mil; Chung, S.; Katz, J.; Namkung, M

    2014-12-20

    We have developed a procedure for observing and tracking proper motions of faint XUV coronal intensity on the Sun and have applied this procedure to study the collective motions of cellular plumes and the shorter-period waves in sunspots. Our space/time maps of cellular plumes show a series of tracks with the same 5-8 minute repetition times and ?100 km s{sup –1} sky-plane speeds found previously in active-region fans and in coronal hole plumes. By synchronizing movies and space/time maps, we find that the tracks are produced by elongated ejections from the unipolar flux concentrations at the bases of the cellular plumes and that the phases of these ejections are uncorrelated from cell to cell. Thus, the large-scale motion is not a continuous flow, but is more like a system of independent conveyor belts all moving in the same direction along the magnetic field. In contrast, the proper motions in sunspots are clearly waves resulting from periodic disturbances in the sunspot umbras. The periods are ?2.6 minutes, but the sky-plane speeds and wavelengths depend on the heights of the waves above the sunspot. In the chromosphere, the waves decelerate from 35-45 km s{sup –1} in the umbra to 7-8 km s{sup –1} toward the outer edge of the penumbra, but in the corona, the waves accelerate to ?60-100 km s{sup –1}. Because chromospheric and coronal tracks originate from the same space/time locations, the coronal waves must emerge from the same umbral flashes that produce the chromospheric waves.

  19. Passive magnetic bearing system

    DOE Patents [OSTI]

    Post, Richard F.

    2014-09-02

    An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.

  20. Multimodal MRI Neuroimaging with Motion Compensation Based on Particle Filtering

    E-Print Network [OSTI]

    Chen, Yu-Hui; Kim, Boklye; Meyer, Charles; Hero, Alfred

    2015-01-01

    Head movement during scanning impedes activation detection in fMRI studies. Head motion in fMRI acquired using slice-based Echo Planar Imaging (EPI) can be estimated and compensated by aligning the images onto a reference volume through image registration. However, registering EPI images volume to volume fails to consider head motion between slices, which may lead to severely biased head motion estimates. Slice-to-volume registration can be used to estimate motion parameters for each slice by more accurately representing the image acquisition sequence. However, accurate slice to volume mapping is dependent on the information content of the slices: middle slices are information rich, while edge slides are information poor and more prone to distortion. In this work, we propose a Gaussian particle filter based head motion tracking algorithm to reduce the image misregistration errors. The algorithm uses a dynamic state space model of head motion with an observation equation that models continuous slice acquisitio...

  1. Pulse magnetic welder

    DOE Patents [OSTI]

    Christiansen, D.W.; Brown, W.F.

    1984-01-01

    A welder is described for automated closure of fuel pins by a pulsed magnetic process in which the open end of a length of cladding is positioned within a complementary tube surrounded by a pulsed magnetic welder. Seals are provided at each end of the tube, which can be evacuated or can receive tag gas for direct introduction to the cladding interior. Loading of magnetic rings and end caps is accomplished automatically in conjunction with the welding steps carried out within the tube.

  2. Magnetic latching solenoid

    DOE Patents [OSTI]

    Marts, D.J.; Richardson, J.G.; Albano, R.K.; Morrison, J.L. Jr.

    1995-11-28

    This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized. 2 figs.

  3. Magnetic Braids Anthony Yeates

    E-Print Network [OSTI]

    Dundee, University of

    function Main result Conclusion Examples 1. Magnetic loops in the solar corona. NASA Solar Dynamics of the potential a Hi,j a x = 2 a xi At each neutral p Hi,j a . The magnet function and it co field topology. Magnetic helicity H = V A·BdV, B = �A is a well-known global ideal invariant in a closed

  4. Magnetic Fields in Population III Star Formation

    SciTech Connect (OSTI)

    Turk, Matthew J.; Oishi, Jeffrey S.; Abel, Tom; Bryan, Greg

    2012-02-22

    We study the buildup of magnetic fields during the formation of Population III star-forming regions, by conducting cosmological simulations from realistic initial conditions and varying the Jeans resolution. To investigate this in detail, we start simulations from identical initial conditions, mandating 16, 32 and 64 zones per Jeans length, and studied the variation in their magnetic field amplification. We find that, while compression results in some amplification, turbulent velocity fluctuations driven by the collapse can further amplify an initially weak seed field via dynamo action, provided there is sufficient numerical resolution to capture vortical motions (we find this requirement to be 64 zones per Jeans length, slightly larger than, but consistent with previous work run with more idealized collapse scenarios). We explore saturation of amplification of the magnetic field, which could potentially become dynamically important in subsequent, fully-resolved calculations. We have also identified a relatively surprising phenomena that is purely hydrodynamic: the higher-resolved simulations possess substantially different characteristics, including higher infall-velocity, increased temperatures inside 1000 AU, and decreased molecular hydrogen content in the innermost region. Furthermore, we find that disk formation is suppressed in higher-resolution calculations, at least at the times that we can follow the calculation. We discuss the effect this may have on the buildup of disks over the accretion history of the first clump to form as well as the potential for gravitational instabilities to develop and induce fragmentation.

  5. The Acceleration of Ions in Solar Flares During Magnetic Reconnection

    E-Print Network [OSTI]

    Knizhnik, Kalman; Drake, James F

    2011-01-01

    The acceleration of solar flare ions during magnetic reconnection is explored via particle-in-cell simulations that self-consistently follow the motions of both protons and $\\alpha$ particles. We demonstrate that the dominant ion heating during reconnection with a guide field (a magnetic component perpendicular to the reconnection plane) results from pickup behavior during the entry into reconnection exhausts. In contrast with anti-parallel reconnection, the temperature increment is dominantly transverse, rather than parallel, to the local magnetic field. The comparison of protons and alphas reveals a mass-to-charge ($M/Q$) threshold in pickup behavior that favors heating of high $M/Q$ ions over protons, which is consistent with impulsive flare observations.

  6. Coulomb Oscillations of Indium-doped ZnO Nanowire Transistors in a Magnetic Field

    E-Print Network [OSTI]

    Xiulai Xu; Andrew C. Irvine; Yang Yang; Xitian Zhang; David A. Williams

    2010-11-05

    We report on the observation of Coulomb oscillations from localized quantum dots superimposed on the normal hopping current in ZnO nanowire transistors. The Coulomb oscillations can be resolved up to 20 K. Positive anisotropic magnetoresistance has been observed due to the Lorentz force on the carrier motion. Magnetic field-induced tunneling barrier transparency results in an increase of oscillation amplitude with increasing magnetic field. The energy shift as a function of magnetic field indicates electron wavefunction modification in the quantum dots.

  7. Motion of spinning test bodies in Kerr spacetime

    E-Print Network [OSTI]

    Eva Hackmann; Claus Lämmerzahl; Yuri N. Obukhov; Dirk Puetzfeld; Isabell Schaffer

    2014-09-23

    We investigate the motion of spinning test bodies in General Relativity. By means of a multipolar approximation method for extended test bodies we derive the equations of motion, and classify the orbital motion of pole-dipole test bodies in the equatorial plane of the Kerr geometry. An exact expression for the periastron shift of a spinning test body is given. Implications of test body spin corrections are studied and compared with the results obtained by means of other approximation schemes.

  8. Magnetically leviated superconducting bearing

    DOE Patents [OSTI]

    Weinberger, Bernard R. (Avon, CT); Lynds, Jr., Lahmer (Glastonbury, CT)

    1993-01-01

    A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.

  9. MAGNET CABLE MANUFACTURING

    E-Print Network [OSTI]

    Royet, J.

    2010-01-01

    76SFOOO98. MAGNET CABLE MANUFACTURING John Royet Lawrenceused in this cable manufacturing are made of superconductingapplied during manufacturing. 2.2 Twist The composite

  10. Motion to Withdraw from Yucca Mountain application | Department...

    Broader source: Energy.gov (indexed) [DOE]

    it's pending license application for a permanent geologic repository at Yucca Mountain, Nevada. Motion to Withdraw from Yucca Mountain application More Documents &...

  11. Wall and laser spot motion in cylindrical hohlraums

    SciTech Connect (OSTI)

    Huser, G.; Courtois, C.; Monteil, M.-C.

    2009-03-15

    Wall and laser spot motion measurements in empty, propane-filled and plastic (CH)-lined gold coated cylindrical hohlraums were performed on the Omega laser facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. Wall motion was measured using axial two-dimensional (2D) x-ray imaging and laser spot motion was perpendicularly observed through a thinned wall using streaked hard x-ray imaging. Experimental results and 2D hydrodynamic simulations show that while empty targets exhibit on-axis plasma collision, CH-lined and propane-filled targets inhibit wall expansion, corroborated with perpendicular streaked imaging showing a slower motion of laser spots.

  12. Real Time Estimation of Ship Motions Using Kalman Filtering Techniques

    E-Print Network [OSTI]

    Triantafyllou, Michael S.

    1983-01-01

    The estimation of the heave, pitch, roll, sway, and yaw motions of a DD-963 destroyer is studied, using Kalman filtering

  13. Joint Motion to Intervene of Northern States Power Company (Minnesota...

    Broader source: Energy.gov (indexed) [DOE]

    Eenrgy Regulatory Commission More Documents & Publications Enron Documents 1993 Ontario Power Generation Motion to Intervene & Comments in FE Docket No. 99-1 Application for...

  14. Seismic Ground Motion Response Using SHAKE, EERA and NERA for...

    Office of Environmental Management (EM)

    Motion Response Using SHAKE, EERA and NERA for SRS Soil Profile Jay Amin - Structural Mechanics, Principal Engineer Shawn Carey, PhD, PE - Structural Mechanics, Structural Lead...

  15. Design and Control of a Ship Motion Simulation Platform from...

    Office of Scientific and Technical Information (OSTI)

    Article: Design and Control of a Ship Motion Simulation Platform from an Energy Efficiency Perspective Citation Details In-Document Search Title: Design and Control of a Ship...

  16. Zeno's First Paradox of Motion: A Cartesian Perspective

    E-Print Network [OSTI]

    Balster, Lori

    Zeno's First Paradox of Motion: A Cartesian Perspective Lori Bolster University of Dayton Before I introduce some of Descartes' perspective into a discussion of Zeno's First Paradox of Motion, I would first like to restate in general what Zeno...'s First Paradox of Motion is. Essentially, Zeno says that, in order for motion from point A to point B to occur, one half of that distance must first be traveled. In order for one half of that distance to be traveled, one fourth of that distance must...

  17. Motion Sensor Driven Gestrure Recognition for Future Internet Application Development

    E-Print Network [OSTI]

    Petrakis, Euripides G.M.

    live their lives in Smart Cities and can use next generation IoT devices (e.g. motion sensors) as part

  18. Entropic Motion in Loop Quantum Gravity

    E-Print Network [OSTI]

    J. Manuel Garcia-Islas

    2015-02-19

    Entropic forces result from an increase of the entropy of a thermodynamical physical system. It has been proposed that gravity is such a phenomenon and many articles have appeared on the literature concerning this problem. Loop quantum gravity has also considered such possibility. We propose a new method in loop quantum gravity which reproduces an entropic force. By considering the interaction between a fixed gravity state space and a particle state in loop quantum gravity, we show that it leads to a mathematical description of a random walk of such particle. The random walk in special situations, can be seen as an entropic motion in such a way that the particle will move towards a location where entropy increases. This may prove that such theory can reproduce gravity as it is expected.

  19. Objectivisation In Simplified Quantum Brownian Motion Models

    E-Print Network [OSTI]

    J. Tuziemski; J. K. Korbicz

    2015-02-24

    Birth of objective properties from subjective quantum world has been one of the key questions in the quantum-to-classical transition. Basing on recent results in the field, we study it in a quantum mechanical model of a boson-boson interaction-quantum Brownian motion. Using various simplifications we prove a formation for thermal environments of, so called, spectrum broadcast structures, responsible for perceived objectivity. In the quantum measurement limit we prove that this structure is always formed, providing the characteristic timescales. Including self-Hamiltonians of the environment, we show the exponential scaling of the effect with the size of the environment. Finally, in the full model we numerically study the influence of squeezing in the initial state of the environment, showing broader regions of formation than for non-squeezed thermal states.

  20. Solid state engine with alternating motion

    DOE Patents [OSTI]

    Golestaneh, A.A.

    1980-01-21

    Heat energy is converted to mechanical motion utilizing apparatus including a cylinder, a piston having openings therein reciprocable in the cylinder, inlet and outlet ports for warm water at one end of the cylinder, inlet and outlet ports for cool water at the other end of the cylinder, gates movable with the piston and slidably engaging the cylinder wall to alternately open and close the warm and cool water ports, a spring bearing against the warm water side of the piston and a double helix of a thermal shape memory material attached to the cool end of the cylinder and to the piston. The piston is caused to reciprocate by alternately admitting cool water and warm water to the cylinder.

  1. Solid state engine with alternating motion

    SciTech Connect (OSTI)

    Golestaneh, A.A.

    1982-04-20

    Heat energy is converted to mechanical motion utilizing apparatus including a cylinder, a piston having openings therein reciprocable in the cylinder, inlet and outlet ports for warm water at one end of the cylinder, inlet and outlet ports for cool water at the other end of the cylinder, gates movable with the piston and slidably engaging the cylinder wall to alternately open and close the warm and cool water ports, a spring bearing against the warm water side of the piston and a double helix of a thermal shape memory material attached to the cool end of the cylinder and to the piston. The piston is caused to reciprocate by alternately admitting cool water and warm water to the cylinder.

  2. Josephson junction of non-Abelian superconductors and non-Abelian Josephson vortices

    E-Print Network [OSTI]

    Muneto Nitta

    2015-08-06

    A Josephson junction is made of two superconductors sandwiching an insulator, and a Josephson vortex is a magnetic vortex (flux tube) absorbed into the Josephson junction, whose dynamics can be described by the sine-Gordon equation. In a field theory framework, a flexible Josephson junction was proposed, in which the Josephson junction is represented by a domain wall separating two condensations and a Josephson vortex is a sine-Gordon soliton in the domain wall effective theory. In this paper, we propose a Josephson junction of non-Abelian color superconductors, that is described by a non-Abelian domain wall, and show that a non-Abelian vortex (color magnetic flux tube) absorbed into it is a non-Abelian Josephson vortex represented as a non-Abelian sine-Gordon soliton in the domain wall effective theory, that is the $U(N)$ principal chiral model.

  3. Josephson junction of non-Abelian superconductors and non-Abelian Josephson vortices

    E-Print Network [OSTI]

    Nitta, Muneto

    2015-01-01

    A Josephson junction is made of two superconductors sandwiching an insulator, and a Josephson vortex is a magnetic vortex absorbed into the Josephson junction, whose dynamics can be described by the sine-Gordon equation. In a field theory framework, a flexible Josephson junction was proposed, in which the Josephson junction is represented by a domain wall separating two condensations and a Josephson vortex is a sine-Gordon soliton in the domain wall effective theory. In this paper, we propose a Josephson junction of non-Abelian color superconductors, that is described by a non-Abelian domain wall, and show that a non-Abelian vortex (color magnetic flux tube) absorbed into it is a non-Abelian Josephson vortex represented as a non-Abelian sine-Gordon soliton in the domain wall effective theory.

  4. Engineering characterization of ground motion. Task II. Observational data on spatial variations of earthquake ground motion. Volume 3

    SciTech Connect (OSTI)

    Chang, C.Y.; Power, M.S.; Idriss, I.M.; Somerville, P.G.; Silva, W.; Chen, P.C.

    1986-02-01

    This report presents the results of part of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this research program sponsored by the US Nuclear Regulatory Commission (USNRC) is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Volume 3 presents observational data on spatial variations of earthquake ground motion.

  5. Nonthermally Dominated Electron Acceleration during Magnetic Reconnection in a Low-beta Plasma

    E-Print Network [OSTI]

    Li, Xiaocan; Li, Hui; Li, Gang

    2015-01-01

    By means of fully kinetic simulations, we show that magnetic reconnection is highly efficient at converting magnetic energy into nonthermal electrons in the nonrelativistic low-beta regimes. This leads to a nonthermally dominated distribution with a power-law tail that contains more than half of the electrons in the system. The main acceleration mechanism is a Fermi-type acceleration accomplished by the curvature drift motion along the electric field induced by Alfv\\'enic plasma flows. A guiding-center description is used to reveal the role of drift motions during the bulk nonthermal energization. The nonthermally dominated acceleration resulting from magnetic reconnection may help explain the highly efficient electron acceleration in solar flares and other astrophysical systems.

  6. SUDDEN PHOTOSPHERIC MOTION AND SUNSPOT ROTATION ASSOCIATED WITH THE X2.2 FLARE ON 2011 FEBRUARY 15

    SciTech Connect (OSTI)

    Wang, Shuo; Liu, Chang; Deng, Na; Wang, Haimin

    2014-02-20

    The Helioseismic and Magnetic Imager provides 45 s cadence intensity images and 720 s cadence vector magnetograms. These unprecedented high-cadence and high-resolution data give us a unique opportunity to study the change of photospheric flows and sunspot rotations associated with flares. By using the differential affine velocity estimator method and the Fourier local correlation tracking method separately, we calculate velocity and vorticity of photospheric flows in the flaring NOAA AR 11158, and investigate their temporal evolution around the X2.2 flare on 2011 February 15. It is found that the shear flow around the flaring magnetic polarity inversion line exhibits a sudden decrease, and both of the two main sunspots undergo a sudden change in rotational motion during the impulsive phase of the flare. These results are discussed in the context of the Lorentz-force change that was proposed by Hudson et al. and Fisher et al. This mechanism can explain the connections between the rapid and irreversible photospheric vector magnetic field change and the observed short-term motions associated with the flare. In particular, the torque provided by the horizontal Lorentz force change agrees with what is required for the measured angular acceleration.

  7. Vacuum self-magnetization?

    SciTech Connect (OSTI)

    Perez Rojas, H.; Rodriguez Querts, E. [Instituto de Cibernetica, Matematica y Fisica, Calle E No. 309, esq. a 15 Vedado, C. Havana (Cuba)

    2006-06-19

    We study vacuum properties in a strong magnetic field as the zero temperature and zero density limit of quantum statistics. For charged vector bosons (W bosons) the vacuum energy density diverges for B > B{sub c} = m{sub w}{sup 2}/e, leading to vacuum instability. A logarithmic divergence of vacuum magnetization is found for B = Bc, which suggests that if the magnetic field is large enough, it is self-consistently maintained, and this mechanism actually prevents B from reaching the critical value Bc. For virtual neutral vector bosons bearing an anomalous magnetic moment, the instability of the ground state for B > B{sub c}{sup '} = m{sub n}{sup 2}/q also leads to the vacuum energy density divergence for fields B > B{sub c}{sup '} and to the magnetization divergence for B B{sub c}{sup '}. The possibility of virtual electron-positron pairs bosonization in strong magnetic field and the applicability of the neutral bosons model to describe the virtual positronium behavior in a magnetic field are discussed. We conjecture that this could lead to vacuum self-magnetization in QED.

  8. Passive magnetic bearing configurations

    DOE Patents [OSTI]

    Post, Richard F. (Walnut Creek, CA)

    2011-01-25

    A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

  9. Superconducting Magnet Division

    E-Print Network [OSTI]

    Ohta, Shigemi

    Superconducting Magnet Division MAGNETIC DESIGN OF E-LENS SOLENOID AND CORRECTOR SYSTEM FOR RHIC* R.6 A gun collectors gun Combined Horizontal and Vertical Corrector Design Both types of dipole correctors. Gupta, M. Anerella, W. Fischer, G. Ganetis, X. Gu, A. Ghosh, A. Jain, P. Kovach, A. Marone, S. Plate, A

  10. Plasticity-Induced Magnetization in Amorphous Magnetic Solids

    E-Print Network [OSTI]

    H. George E. Hentschel; Itamar Procaccia; Bhaskar Sen Gupta

    2013-10-15

    Amorphous magnetic solids, like metallic glasses, exhibit a novel effect: the growth of magnetic order as a function of mechanical strain under athermal conditions in the presence of a magnetic field. The magnetic moment increases in steps whenever there is a plastic event. Thus plasticity induces the magnetic ordering, acting as the effective noise driving the system towards equilibrium. We present results of atomistic simulations of this effect in a model of a magnetic amorphous solid subjected to pure shear and a magnetic field. To elucidate the dependence on external strain and magnetic field we offer a mean-field theory that provides an adequate qualitative understanding of the observed phenomenon.

  11. Disk Accretion Flow Driven by Large-Scale Magnetic Fields: Solutions with Constant Specific Energy

    E-Print Network [OSTI]

    Li-Xin Li

    2003-05-29

    (Abridged) We study the dynamical evolution of a stationary, axisymmetric, and perfectly conducting cold accretion disk containing a large-scale magnetic field around a Kerr black hole, trying to understand the relation between accretion and the transportation of angular momentum and energy. We solve the radial momentum equation for solutions corresponding to an accretion flow that starts from a subsonic state at infinity, smoothly passes the fast critical point, then supersonically falls into the horizon of the black hole. The solutions always have the following features: 1) The specific energy of fluid particles remains constant but the specific angular momentum is effectively removed by the magnetic field. 2) At large radii, where the disk motion is dominantly rotational, the energy density of the magnetic field is equipartitioned with the rotational energy density of the disk. 3) Inside the fast critical point, where radial motion becomes important, the ratio of the electromagnetic energy density to the kinetic energy density drops quickly. The results indicate that: 1) Disk accretion does not necessarily imply energy dissipation since magnetic fields do not have to transport or dissipate a lot of energy as they effectively transport angular momentum. 2) When resistivity is small, the large-scale magnetic field is amplified by the shearing rotation of the disk until the magnetic energy density is equipartitioned with the rotational energy density, ending up with a geometrically thick disk. This is in contrast with the evolution of small-scale magnetic fields where if the resistivity is nonzero the magnetic energy density is likely to be equipartitioned with the kinetic energy density associated with local random motions (e.g., turbulence), making a thin Keplerian disk possible.

  12. Effect of magnetic field on the wave dispersion relation in three-dimensional dusty plasma crystals

    SciTech Connect (OSTI)

    Yang Xuefeng [School of Mathematical Sciences, Dalian University of Technology, Dalian 116024 (China); Wang Zhengxiong [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2012-07-15

    Three-dimensional plasma crystals under microgravity condition are investigated by taking into account an external magnetic field. The wave dispersion relations of dust lattice modes in the body centered cubic (bcc) and the face centered cubic (fcc) plasma crystals are obtained explicitly when the magnetic field is perpendicular to the wave motion. The wave dispersion relations of dust lattice modes in the bcc and fcc plasma crystals are calculated numerically when the magnetic field is in an arbitrary direction. The numerical results show that one longitudinal mode and two transverse modes are coupled due to the Lorentz force in the magnetic field. Moreover, three wave modes, i.e., the high frequency phonon mode, the low frequency phonon mode, and the optical mode, are obtained. The optical mode and at least one phonon mode are hybrid modes. When the magnetic field is neither parallel nor perpendicular to the primitive wave motion, all the three wave modes are hybrid modes and do not have any intersection points. It is also found that with increasing the magnetic field strength, the frequency of the optical mode increases and has a cutoff at the cyclotron frequency of the dust particles in the limit of long wavelength, and the mode mixings for both the optical mode and the high frequency phonon mode increase. The acoustic velocity of the low frequency phonon mode is zero. In addition, the acoustic velocity of the high frequency phonon mode depends on the angle of the magnetic field and the wave motion but does not depend on the magnetic field strength.

  13. Magnet pole tips

    DOE Patents [OSTI]

    Thorn, Craig E. (Wading River, NY); Chasman, Chellis (Setauket, NY); Baltz, Anthony J. (Coram, NY)

    1984-04-24

    An improved magnet which more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

  14. Magnet pole tips

    DOE Patents [OSTI]

    Thorn, C.E.; Chasman, C.; Baltz, A.J.

    1981-11-19

    An improved magnet more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

  15. Five-minute oscillation power within magnetic elements in the solar atmosphere

    SciTech Connect (OSTI)

    Jain, Rekha; Gascoyne, Andrew [School of Mathematics and Statistics, University of Sheffield, Sheffield S3 7RH (United Kingdom); Hindman, Bradley W.; Greer, Benjamin, E-mail: R.Jain@sheffield.ac.uk [JILA, University of Colorado, Boulder, CO 80309-0440 (United States)

    2014-12-01

    It has long been known that magnetic plage and sunspots are regions in which the power of acoustic waves is reduced within the photospheric layers. Recent observations now suggest that this suppression of power extends into the low chromosphere and is also present in small magnetic elements far from active regions. In this paper we investigate the observed power suppression in plage and magnetic elements, by modeling each as a collection of vertically aligned magnetic fibrils and presuming that the velocity within each fibril is the response to buffeting by incident p modes in the surrounding field-free atmosphere. We restrict our attention to modeling observations made near the solar disk center, where the line-of-sight velocity is nearly vertical and hence, only the longitudinal component of the motion within the fibril contributes. Therefore, we only consider the excitation of axisymmetric sausage waves and ignore kink oscillations as their motions are primarily horizontal. We compare the vertical motion within the fibril with the vertical motion of the incident p mode by constructing the ratio of their powers. In agreement with observational measurements we find that the total power is suppressed within strong magnetic elements for frequencies below the acoustic cut-off frequency. However, further physical effects need to be examined for understanding the observed power ratios for stronger magnetic field strengths and higher frequencies. We also find that the magnitude of the power deficit increases with the height above the photosphere at which the measurement is made. Furthermore, we argue that the area of the solar disk over which the power suppression extends increases as a function of height.

  16. Hot Jupiters and stellar magnetic activity

    E-Print Network [OSTI]

    A. F. Lanza

    2008-05-20

    Recent observations suggest that stellar magnetic activity may be influenced by the presence of a close-by giant planet. Specifically, chromospheric hot spots rotating in phase with the planet orbital motion have been observed during some seasons in a few stars harbouring hot Jupiters. The spot leads the subplanetary point by a typical amount of about 60-70 degrees, with the extreme case of upsilon And where the angle is about 170 degrees. The interaction between the star and the planet is described considering the reconnection between the stellar coronal field and the magnetic field of the planet. Reconnection events produce energetic particles that moving along magnetic field lines impact onto the stellar chromosphere giving rise to a localized hot spot. A simple magnetohydrostatic model is introduced to describe the coronal magnetic field of the star connecting its surface to the orbiting planet. The field is assumed to be axisymmetric around the rotation axis of the star and its configuration is more general than a linear force-free field. With a suitable choice of the free parameters, the model can explain the phase differences between the hot spots and the planets observed in HD 179949, upsilon And, HD 189733, and tau Bootis, as well as their visibility modulation on the orbital period and seasonal time scales. The possible presence of cool spots associated with the planets in tau Boo and HD 192263 cannot be explained by the present model. However, we speculate about the possibility that reconnection events in the corona may influence subphotospheric dynamo action in those stars producing localized photospheric (and chromospheric) activity migrating in phase with their planets.

  17. MOTION OF ELECTRON-HOLE DROPS IN Ge

    E-Print Network [OSTI]

    Westervelt, R.M.

    2011-01-01

    MOTION OF ELECTRON-HOLE DROPS IN Ge R. M. Westervelt, J. C.MOTION OF ELECTRON-HOLE DROPS IN Ge R. M. Westervelt, J. C.OF ELECTRON-HOLE DROPS IN Ge R M Westervelt, J C Culbertson

  18. Ideal Observers for Detecting Human Motion: Correspondence Noise.

    E-Print Network [OSTI]

    Yuille, Alan L.

    purpose, models of motion. We perform more psychophysical experiments which are consistent with humansIdeal Observers for Detecting Human Motion: Correspondence Noise. HongJing Lo Department obtain Barlow and Tripathy's classic model as an approximation. Our psychophysical experiments show

  19. Human Motion Capture Data Compression by Model-Based Indexing

    E-Print Network [OSTI]

    Bhandarkar, Suchendra "Suchi" M.

    Human Motion Capture Data Compression by Model-Based Indexing: A Power Aware Approach Siddhartha Chattopadhyay, Suchendra M. Bhandarkar, Member, IEEE, and Kang Li Abstract--Human Motion Capture (MoCap) data can be used for animation of virtual human-like characters in distributed virtual reality applications

  20. A Wireless Human Motion Capturing System for Home Rehabilitation

    E-Print Network [OSTI]

    Tseng, Yu-Chee

    A Wireless Human Motion Capturing System for Home Rehabilitation Yu-Chee Tseng, Chin-Hao Wu, Fang the use of intelligent sensors to capture human motions for home rehabilitation. We design a game to help a patient to conduct his/her rehabilitation program. For each exercise, the patient is instructed to wear

  1. Knee's Motion Path Relative to the Passive Coupled Kinematic Envelope

    E-Print Network [OSTI]

    Dodd, Kevin A.

    2009-06-15

    , and describe motion relative to them. The coupled envelopes of internal/external (IE), varus/ valgus (VV), and anterior/ posterior (AP) motion and a neutral path were used to describe loaded lunges and a simulated walk cycle. The envelopes were created...

  2. Changes in Pilot Control Behaviour across Stewart Platform Motion Systems

    E-Print Network [OSTI]

    Changes in Pilot Control Behaviour across Stewart Platform Motion Systems F. M. Nieuwenhuizen1,2, H system bandwidth has a significant effect on performance and control behaviour. Participants barely use of Korea Low-cost motion systems have been proposed for certain training tasks that would otherwise

  3. Radon-based Structure from Motion Without Correspondences Ameesh Makadia

    E-Print Network [OSTI]

    Sastry, S. Shankar

    Radon-based Structure from Motion Without Correspondences Ameesh Makadia Christopher Geyer Shankar present a novel approach for the estimation of 3D- motion directly from two images using the Radon trans is in the realization that the Radon transform is a filtering operator: If we assume that im- ages are defined

  4. Soft Wearable Motion Sensing Suit for Lower Limb Biomechanics Measurements*

    E-Print Network [OSTI]

    Wood, Robert

    Soft Wearable Motion Sensing Suit for Lower Limb Biomechanics Measurements* Yigit Meng¨uc¸1,2, Yong of human biomechanics as well as the entertainment industry. Although existing technologies motion data in order to understand the underlying biomechanics. Simulation tools such as Open- Sim [2

  5. Sparsification of Motion-Planning Roadmaps by Edge Contraction

    E-Print Network [OSTI]

    Agarwal, Pankaj K.

    Sparsification of Motion-Planning Roadmaps by Edge Contraction Doron Shaharabani, Oren Salzman Department of Computer Science, Duke University, USA Abstract--We present Roadmap Sparsification by Edge Con- traction (RSEC), a simple and effective algorithm for reducing the size of a motion-planning roadmap

  6. Applications of nonlocal constants of motion in Lagrangian Dynamics

    E-Print Network [OSTI]

    Gianluca Gorni; Gaetano Zampieri

    2015-01-29

    We give a recipe to generate "nonlocal" constants of motion for ODE Lagrangian systems and we apply the method to find useful constants of motion for dissipative system, for the Lane-Emden equation, and for the Maxwell-Bloch system with RWA.

  7. Method and apparatus for planning motions of robot manipulators

    DOE Patents [OSTI]

    Chen, Pang C. (4000 Camino De La Sierra, N.E., Albuquerque, NM 87111); Hwang, Yong K. (9036 Walter Bambrook, N.E., Albuquerque, NM 87122)

    1996-01-01

    Method and apparatus for automatically planning motions of robot manipulators. The invention rapidly finds a collision-free path in a cluttered robot environment, if one exists, from any starting configuration of the robot manipulator to any ending configuration. The time to solution of a motion planning problem is not uniform, but proportional to the complexity of the problem.

  8. LABORATORY I: DESCRIPTION OF MOTION IN ONE DIMENSION

    E-Print Network [OSTI]

    Minnesota, University of

    Lab I - 1 LABORATORY I: DESCRIPTION OF MOTION IN ONE DIMENSION In this laboratory you will measure with your instructor. Remember, one of the reasons for doing physics in a laboratory setting is to help you this laboratory, you should be able to: · Describe completely the motion of any object moving in one dimension

  9. LABORATORY II DESCRIPTION OF MOTION IN TWO DIMENSIONS

    E-Print Network [OSTI]

    Minnesota, University of

    Lab II - 1 LABORATORY II DESCRIPTION OF MOTION IN TWO DIMENSIONS In this laboratory you continue the study of accelerated motion in more situations. The carts you used in Laboratory I moved in only one instructor. OBJECTIVES: After successfully completing this laboratory, you should be able to: · Determine

  10. LABORATORY I: DESCRIPTION OF MOTION IN ONE DIMENSION

    E-Print Network [OSTI]

    Minnesota, University of

    Lab I - 1 LABORATORY I: DESCRIPTION OF MOTION IN ONE DIMENSION In this laboratory you will measure with your instructor. Remember, one of the reasons for doing physics in a laboratory setting is to help you: After you successfully complete this laboratory, you should be able to: · Describe completely the motion

  11. LABORATORY II DESCRIPTION OF MOTION IN TWO DIMENSIONS

    E-Print Network [OSTI]

    Minnesota, University of

    Lab II - 1 LABORATORY II DESCRIPTION OF MOTION IN TWO DIMENSIONS In this laboratory you continue the study of accelerated motion in more situations. The carts you used in Laboratory I moved in only one or your instructor. OBJECTIVES: After successfully completing this laboratory, you should be able to

  12. Automatic Detection and Segmentation of Robot-Assisted Surgical Motions

    E-Print Network [OSTI]

    Shafran, Izhak

    ) with classification accuracy approaching 90%. However, these results rely on a manual interpretation of recorded video of Computer Science 2 Department of Electrical and Computer Engineering 3 Department of Mechanical Engineering or motion enhancements to the surgeon. However, in every case, the key step is to relate recorded motion

  13. Creating Robust Roadmaps for Motion Planning in Changing Environments

    E-Print Network [OSTI]

    van den Berg, Jur

    Creating Robust Roadmaps for Motion Planning in Changing Environments Jur P. van den Berg1 Dennis-- In this paper we introduce a method based on the Probabilistic Roadmap (PRM) Planner to construct robust roadmaps for motion planning in changing environments. PRM's are usually aimed at static environments

  14. Motion Planning Using Dynamic Roadmaps Marcelo Kallmann and Maja Mataric

    E-Print Network [OSTI]

    Kallmann, Marcelo

    Motion Planning Using Dynamic Roadmaps Marcelo Kallmann and Maja Mataric Interaction Lab, Computer, mataric}@usc.edu Abstract - We evaluate the use of dynamic roadmaps for on- line motion planning and nodes of a precomputed roadmap are updated accordingly. We concentrate in this paper on analyzing

  15. Roadmap-based Motion Planning in Dynamic Environments

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Roadmap-based Motion Planning in Dynamic Environments Jur P. van den Berg Mark H. Overmars.cs.uu.nl #12;Roadmap-based Motion Planning in Dynamic Environments Jur P. van den Berg Mark H. Overmars April obstacles. We propose a practical algorithm based on a roadmap that is created for the static part

  16. Creating Highquality Roadmaps for Motion Planning in Virtual Environments

    E-Print Network [OSTI]

    Geraerts, R.J.

    Creating High­quality Roadmaps for Motion Planning in Virtual Environments Roland Geraerts and Mark, the Netherlands Email: {roland,markov}@cs.uu.nl Abstract--- Our goal is to create roadmaps that are particularly suited for motion planning in virtual environments. We use our Reachability Roadmap Method to compute

  17. Bioinspired Design : : Magnetic Freeze Casting

    E-Print Network [OSTI]

    Porter, Michael Martin

    2014-01-01

    30 CHAPTER 3: FREEZE CASTING: A94 CHAPTER 5: MAGNETIC FREEZE CASTING INSPIRED BY98 5.2.1. Magnetic freeze casting

  18. Electromagnetic acceleration of permanent magnets

    E-Print Network [OSTI]

    Dolya, S N

    2015-01-01

    We consider the acceleration of the permanent magnets, consisting of neodymium iron boron by means of the running magnetic field gradient. It is shown that the specific magnetic moment per nucleon in neodymium iron boron is determined by the remained magnetization of the substance. The maximum accessable gradient of the magnetic field accelerating the permanent magnets is determined by the coercive force thirty kilogauss. For the neodymium iron boron magnets this gradient is equal to twenty kilogauss divided by one centimeter. The finite velocity of the magnets six kilometers per second, the length of acceleration is six hundred thirty-seven meters.

  19. Lensless Imaging of Magnetic Nanostructures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine. By studying...

  20. QUENCHES IN LARGE SUPERCONDUCTING MAGNETS

    E-Print Network [OSTI]

    Eberhard, P.H.

    2010-01-01

    QUENCHES IN LARGE SUPERCONDUCTING MAGNETS. P. H. Eberhard,Study of an Unprotected Superconducting Coil Going Normal,"Method for Testing Superconducting Magnets," LBL Physics

  1. Large Magnetization at Carbon Surfaces

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Large Magnetization at Carbon Surfaces Large Magnetization at Carbon Surfaces Print Wednesday, 31 August 2011 00:00 From organic matter to pencil lead, carbon is a versatile...

  2. The allwise motion survey and the quest for cold subdwarfs

    SciTech Connect (OSTI)

    Kirkpatrick, J. Davy; Fajardo-Acosta, Sergio; Gelino, Christopher R.; Fowler, John W.; Cutri, Roc M.; Schneider, Adam; Cushing, Michael C.; Mace, Gregory N.; Wright, Edward L.; Logsdon, Sarah E.; McLean, Ian S.; Skrutskie, Michael F.; Eisenhardt, Peter R.; Stern, Daniel; Balokovi?, Mislav; Burgasser, Adam J.; Faherty, Jacqueline K.; Lansbury, George B.; Rich, J. A.; Skrzypek, Nathalie; and others

    2014-03-10

    The AllWISE processing pipeline has measured motions for all objects detected on Wide-field Infrared Survey Explorer (WISE) images taken between 2010 January and 2011 February. In this paper, we discuss new capabilities made to the software pipeline in order to make motion measurements possible, and we characterize the resulting data products for use by future researchers. Using a stringent set of selection criteria, we find 22,445 objects that have significant AllWISE motions, of which 3525 have motions that can be independently confirmed from earlier Two Micron All Sky Survey (2MASS) images, yet lack any published motions in SIMBAD. Another 58 sources lack 2MASS counterparts and are presented as motion candidates only. Limited spectroscopic follow-up of this list has already revealed eight new L subdwarfs. These may provide the first hints of a 'subdwarf gap' at mid-L types that would indicate the break between the stellar and substellar populations at low metallicities (i.e., old ages). Another object in the motion list—WISEA J154045.67–510139.3—is a bright (J ? 9 mag) object of type M6; both the spectrophotometric distance and a crude preliminary parallax place it ?6 pc from the Sun. We also compare our list of motion objects to the recently published list of 762 WISE motion objects from Luhman. While these first large motion studies with WISE data have been very successful in revealing previously overlooked nearby dwarfs, both studies missed objects that the other found, demonstrating that many other nearby objects likely await discovery in the AllWISE data products.

  3. Automatically Generating Eye Motion in Virtual Agents Eye Motion has a fundamental role in verbal and non-verbal

    E-Print Network [OSTI]

    Animation's applications, such as virtual humans in general and game/movies characters. This paper presents tagging 1. INTRODUCTION Virtual humans have been widely used in many applica- tions. One is concernedAutomatically Generating Eye Motion in Virtual Agents ABSTRACT Eye Motion has a fundamental role

  4. Magnetically Catalyzed Fusion

    E-Print Network [OSTI]

    Jeremy S. Heyl; Lars Hernquist

    1996-08-25

    We calculate the reaction cross-sections for the fusion of hydrogen and deuterium in strong magnetic fields as are believed to exist in the atmospheres of neutron stars. We find that in the presence of a strong magnetic field ($B \\gsim 10^{12}$G), the reaction rates are many orders of magnitude higher than in the unmagnetized case. The fusion of both protons and deuterons are important over a neutron star's lifetime for ultrastrong magnetic fields ($B \\sim 10^{16}$G). The enhancement may have dramatic effects on thermonuclear runaways and bursts on the surfaces of neutron stars.

  5. Moment free toroidal magnet

    DOE Patents [OSTI]

    Bonanos, Peter (East Brunswick, NJ)

    1983-01-01

    A toroidal magnet for confining a high magnetic field for use in fusion reactor research and nuclear particle detection. The magnet includes a series of conductor elements arranged about and fixed at its small major radius portion to the outer surface of a central cylindrical support each conductor element having a geometry such as to maintain the conductor elements in pure tension when a high current flows therein, and a support assembly which redistributes all or part of the tension which would otherwise arise in the small major radius portion of each coil element to the large major radius portion thereof.

  6. M. Flierl: Adaptive Spatial Wavelets for Motion-Compensated Orthogonal Video Transforms, IEEE ICIP, Cairo, Egypt, Nov. 2009. 1 ADAPTIVE SPATIAL WAVELETS FOR MOTION-COMPENSATED

    E-Print Network [OSTI]

    Flierl, Markus

    , Cairo, Egypt, Nov. 2009. 1 ADAPTIVE SPATIAL WAVELETS FOR MOTION-COMPENSATED ORTHOGONAL VIDEO TRANSFORMS

  7. Anisotropy of magnetic emulsions induced by magnetic and electric fields

    E-Print Network [OSTI]

    Yury I. Dikansky; Alexander N. Tyatyushkin; Arthur R. Zakinyan

    2011-09-10

    The anisotropy of magnetic emulsions induced by simultaneously acting electric and magnetic fields is theoretically and experimentally investigated. Due to the anisotropy, the electric conductivity and magnetic permeability of a magnetic emulsion are no longer scalar coefficients, but are tensors. The electric conductivity and magnetic permeability tensors of sufficiently diluted emulsions in sufficiently weak electric and magnetic fields are found as functions of the electric and magnetic intensity vectors. The theoretically predicted induced anisotropy was verified experimentally. The experimental data are analyzed and compared with theoretical predictions. The results of the analysis and comparison are discussed.

  8. 4 K to 20 K rotational-cooling magnetic refrigerator capable of 1-mW to >1-W operation

    SciTech Connect (OSTI)

    Barclay, J.A.

    1980-02-01

    The low-temperature, magnetic entropy of certain single-crystal paramagnetic materials, such as DyPO/sub 4/, changes dramatically as the crystal rotates in a magnetic field. A new magnetic refrigerator design based on the anisotropic nature of such materials is presented. The key advantages of the rotational-cooling concept are (1) a single, rotary motion is required, (2) magnetic field shaping is not a problem because the entire working material is in a constant field, and (3) the refrigerator can be smaller than comparable magnetic refrigerators because the working material is entirely inside the magnet at all times. The main disadvantage of the rotational-cooling concept is that small-dimension single crystals are required.

  9. Design of the magnetic diagnostics unit onboard LISA Pathfinder

    E-Print Network [OSTI]

    Marc Diaz-Aguiló; Ignacio Mateos; Juan Ramos-Castro; Alberto Lobo; Enrique García-Berro

    2012-02-13

    LISA (Laser Interferometer Space Antenna) is a joint mission of ESA and NASA which aims to be the first space-borne gravita- tional wave observatory. Due to the high complexity and technological challenges that LISA will face, ESA decided to launch a technological demonstrator, LISA Pathfinder. The payload of LISA Pathfinder is the so-called LISA Technology Package, and will be the highest sensitivity geodesic explorer flown to date. The LISA Technology Package is designed to measure relative accelerations between two test masses in nominal free fall (geodesic motion). The magnetic, thermal and radiation disturbances affecting the payload are monitored and dealt by the diagnostics subsystem. The diagnostics subsystem consists of several modules, and one of these is the magnetic diagnostics unit. Its main function is the assessment of differential acceleration noise between test masses due to the magnetic effects. To do so, it has to determine the magnetic characteristics of the test masses, namely their magnetic remanences and susceptibilities. In this paper we show how this can be achieved to the desired accuracy.

  10. Modular tokamak magnetic system

    DOE Patents [OSTI]

    Yang, Tien-Fang (Wayland, MA)

    1988-01-01

    A modular tokamak system comprised of a plurality of interlocking moldules. Each module is comprised of a vacuum vessel section, a toroidal field coil, moldular saddle coils which generate a poloidal magnetic field and ohmic heating coils.

  11. Geometrically frustrated quantum magnets

    E-Print Network [OSTI]

    Nikolić , Predrag, 1974-

    2004-01-01

    (cont.) more general lessons on frustrated quantum magnetism. At the end, we demonstrate some new mathematical tools on two other frustrated two-dimensional systems, and summarize our conclusions, with an outlook to remaining ...

  12. Magnetic gripper device

    DOE Patents [OSTI]

    Meyer, R.E.

    1993-03-09

    A climbing apparatus is provided for climbing ferromagnetic surfaces, such as storage tanks and steel frame structures. A magnet assembly is rotatably mounted in a frame assembly. The frame assembly provides a pair of cam surfaces having different dimensions so that, when the frame is rotated, the cam surfaces contact the ferromagnetic surface to separate the magnet assembly from the surface. The different cam dimensions enable one side of the magnet at a time to be detached from the surface to reduce the effort needed to disengage the climbing apparatus. The cam surface also provides for smoothly attaching the apparatus. A hardened dowel pin is also attached to the frame and the pointed end of the dowel engages the surface when the magnet is attached to the surface to prevent downward sliding movement of the assembly under the weight of the user.

  13. Magnetic Catalysis in Graphene

    E-Print Network [OSTI]

    Christopher Winterowd; Carleton DeTar; Savvas Zafeiropoulos

    2015-09-22

    One of the most important developments in condensed matter physics in recent years has been the discovery and characterization of graphene. A two-dimensional layer of Carbon arranged in a hexagonal lattice, graphene exhibits many interesting electronic properties, most notably that the low energy excitations behave as massless Dirac fermions. These excitations interact strongly via the Coulomb interaction and thus non-perturbative methods are necessary. Using methods borrowed from lattice QCD, we study the graphene effective theory in the presence of an external magnetic field. Graphene, along with other $(2+1)$-dimensional field theories, has been predicted to undergo spontaneous breaking of flavor symmetry including the formation of a gap as a result of the external magnetic field. This phenomenon is known as magnetic catalysis. Our study investigates magnetic catalysis using a fully non-perturbative approach.

  14. Magnetic Catalysis in Graphene

    E-Print Network [OSTI]

    Winterowd, Christopher; Zafeiropoulos, Savvas

    2015-01-01

    One of the most important developments in condensed matter physics in recent years has been the discovery and characterization of graphene. A two-dimensional layer of Carbon arranged in a hexagonal lattice, graphene exhibits many interesting electronic properties, most notably that the low energy excitations behave as massless Dirac fermions. These excitations interact strongly via the Coulomb interaction and thus non-perturbative methods are necessary. Using methods borrowed from lattice QCD, we study the graphene effective theory in the presence of an external magnetic field. Graphene, along with other $(2+1)$-dimensional field theories, has been predicted to undergo spontaneous breaking of flavor symmetry including the formation of a gap as a result of the external magnetic field. This phenomenon is known as magnetic catalysis. Our study investigates magnetic catalysis using a fully non-perturbative approach.

  15. Magnetic gripper device

    DOE Patents [OSTI]

    Meyer, Ross E. (Los Alamos, NM)

    1993-01-01

    A climbing apparatus is provided for climbing ferromagnetic surfaces, such as storage tanks and steel frame structures. A magnet assembly is rotatably mounted in a frame assembly. The frame assembly provides a pair of cam surfaces having different dimensions so that, when the frame is rotated, the cam surfaces contact the ferromagnetic surface to separate the magnet assembly from the surface. The different cam dimensions enable one side of the magnet at a time to be detached from the surface to reduce the effort needed to disengage the climbing apparatus. The cam surface also provides for smoothly attaching the apparatus. A hardened dowel pin is also attached to the frame and the pointed end of the dowel engages the surface when the magnet is attached to the surface to prevent downward sliding movement of the assembly under the weight of the user.

  16. ZEEMANS - a high magnetic

    SciTech Connect (OSTI)

    Savici, Andrei T [ORNL; Granroth, Garrett E [ORNL; Broholm, Collin L [ORNL; Bird, Mark D [ORNL; Lee, Young S [ORNL

    2010-01-01

    ZEEMANS, a new instrument proposed for the Spallation Neutron Source (SNS) at Oak Ridge, will provide highest available magnetic elds for neutron scattering experiments. The unique capabilities of the magnet, large size and required connection to utilities demand a versatile instrument, able of performing diraction (powder and single crystal), SANS, re ectometry, and inelastic spectrometry, with minimal modications between congurations. In this paper we present preliminary design features for ZEEMANS. Monte Carlo simulations and analytical calculations were used to study its expected performance.

  17. Magnetic coupling device

    DOE Patents [OSTI]

    Nance, Thomas A. (Aiken, SC)

    2009-08-18

    A quick connect/disconnect coupling apparatus is provided in which a base member is engaged by a locking housing through a series of interengagement pins. The pins maintain the shaft in a locked position. Upon exposure to an appropriately positioned magnetic field, pins are removed a sufficient distance such that the shaft may be withdrawn from the locking housing. The ability to lock and unlock the connector assembly requires no additional tools or parts apart from a magnetic key.

  18. Magnetic fluorescent lamp

    DOE Patents [OSTI]

    Berman, S.M.; Richardson R.W.

    1983-12-29

    The radiant emission of a mercury-argon discharge in a fluorescent lamp assembly is enhanced by providing means for establishing a magnetic field with lines of force along the path of electron flow through the bulb of the lamp assembly, to provide Zeeman splitting of the ultraviolet spectral line. Optimum results are obtained when the magnetic field strength causes a Zeeman splitting of approximately 1.7 times the thermal line width.

  19. arXiv:cond-mat/0307631v125Jul2003 typeset using JPSJ.sty

    E-Print Network [OSTI]

    magnetization. If the magnetic field is reversed, then the anti-domain of the magnetization appears at the edge conductivity of nanowires in the presence of magnetic domain walls by the method of wave packet propagation. We simulation. We propose a procedure, based on the Landauer formula, to reduce this dependence. Direct

  20. Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization

    DOE Patents [OSTI]

    Doughty, Frank C. (Plano, TX); Spencer, John E. (Plano, TX)

    2000-12-19

    In a plasma-producing device, an optimized magnet field for electron cyclotron resonance plasma generation is provided by a shaped pole piece. The shaped pole piece adjusts spacing between the magnet and the resonance zone, creates a convex or concave resonance zone, and decreases stray fields between the resonance zone and the workpiece. For a cylindrical permanent magnet, the pole piece includes a disk adjacent the magnet together with an annular cylindrical sidewall structure axially aligned with the magnet and extending from the base around the permanent magnet. The pole piece directs magnetic field lines into the resonance zone, moving the resonance zone further from the face of the magnet. Additional permanent magnets or magnet arrays may be utilized to control field contours on a local scale. Rather than a permeable material, the sidewall structure may be composed of an annular cylindrical magnetic material having a polarity opposite that of the permanent magnet, creating convex regions in the resonance zone. An annular disk-shaped recurve section at the end of the sidewall structure forms magnetic mirrors keeping the plasma off the pole piece. A recurve section composed of magnetic material having a radial polarity forms convex regions and/or magnetic mirrors within the resonance zone.