National Library of Energy BETA

Sample records for magnetic domain-wall motion

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

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

    X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print Wednesday, 26 September 2007 00:00 The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray

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

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

    X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be

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

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

    X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be

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

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

    X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be

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

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

    X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be

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

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

    X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be

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

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

    X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be

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

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

    X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be

  9. Electric field driven magnetic domain wall motion in ferromagnetic-ferroelectric heterostructures

    SciTech Connect (OSTI)

    Van de Wiele, Ben; Laurson, Lasse; Franke, Kvin J. A.; Dijken, Sebastiaan van

    2014-01-06

    We investigate magnetic domain wall (MDW) dynamics induced by applied electric fields in ferromagnetic-ferroelectric thin-film heterostructures. In contrast to conventional driving mechanisms where MDW motion is induced directly by magnetic fields or electric currents, MDW motion arises here as a result of strong pinning of MDWs onto ferroelectric domain walls (FDWs) via local strain coupling. By performing extensive micromagnetic simulations, we find several dynamical regimes, including instabilities such as spin wave emission and complex transformations of the MDW structure. In all cases, the time-averaged MDW velocity equals that of the FDW, indicating the absence of Walker breakdown.

  10. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    Stochastic Domain-Wall Depinning in Magnetic Nanowires Stochastic Domain-Wall Depinning in Magnetic Nanowires Print Wednesday, 29 July 2009 00:00 Reliably controlling the motion of magnetic domain walls along magnetic nanowires is a key requirement for current technological development of novel classes of logic and storage devices, but understanding the nature of non-deterministic domain-wall motion remains a scientific challenge. A statistical analysis of high-resolution magnetic soft x-ray

  11. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    Stochastic Domain-Wall Depinning in Magnetic Nanowires Print Reliably controlling the motion of magnetic domain walls along magnetic nanowires is a key requirement for current technological development of novel classes of logic and storage devices, but understanding the nature of non-deterministic domain-wall motion remains a scientific challenge. A statistical analysis of high-resolution magnetic soft x-ray microscopy images by a Berkeley Lab-University of Hamburg group has now revealed that

  12. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    Stochastic Domain-Wall Depinning in Magnetic Nanowires Print Reliably controlling the motion of magnetic domain walls along magnetic nanowires is a key requirement for current technological development of novel classes of logic and storage devices, but understanding the nature of non-deterministic domain-wall motion remains a scientific challenge. A statistical analysis of high-resolution magnetic soft x-ray microscopy images by a Berkeley Lab-University of Hamburg group has now revealed that

  13. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    Stochastic Domain-Wall Depinning in Magnetic Nanowires Print Reliably controlling the motion of magnetic domain walls along magnetic nanowires is a key requirement for current technological development of novel classes of logic and storage devices, but understanding the nature of non-deterministic domain-wall motion remains a scientific challenge. A statistical analysis of high-resolution magnetic soft x-ray microscopy images by a Berkeley Lab-University of Hamburg group has now revealed that

  14. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    Stochastic Domain-Wall Depinning in Magnetic Nanowires Print Reliably controlling the motion of magnetic domain walls along magnetic nanowires is a key requirement for current technological development of novel classes of logic and storage devices, but understanding the nature of non-deterministic domain-wall motion remains a scientific challenge. A statistical analysis of high-resolution magnetic soft x-ray microscopy images by a Berkeley Lab-University of Hamburg group has now revealed that

  15. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    Stochastic Domain-Wall Depinning in Magnetic Nanowires Print Reliably controlling the motion of magnetic domain walls along magnetic nanowires is a key requirement for current technological development of novel classes of logic and storage devices, but understanding the nature of non-deterministic domain-wall motion remains a scientific challenge. A statistical analysis of high-resolution magnetic soft x-ray microscopy images by a Berkeley Lab-University of Hamburg group has now revealed that

  16. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    Stochastic Domain-Wall Depinning in Magnetic Nanowires Print Reliably controlling the motion of magnetic domain walls along magnetic nanowires is a key requirement for current technological development of novel classes of logic and storage devices, but understanding the nature of non-deterministic domain-wall motion remains a scientific challenge. A statistical analysis of high-resolution magnetic soft x-ray microscopy images by a Berkeley Lab-University of Hamburg group has now revealed that

  17. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    Stochastic Domain-Wall Depinning in Magnetic Nanowires Print Reliably controlling the motion of magnetic domain walls along magnetic nanowires is a key requirement for current technological development of novel classes of logic and storage devices, but understanding the nature of non-deterministic domain-wall motion remains a scientific challenge. A statistical analysis of high-resolution magnetic soft x-ray microscopy images by a Berkeley Lab-University of Hamburg group has now revealed that

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

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

    One of these, called racetrack memory, involves no rotating disk at all. Instead, it is based on wires made of a magnetic ... by applying and releasing an external magnetic field (Hext). ...

  19. 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.

  20. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    concept called a racetrack memory, for example, the electron spin provides the driving force that moves a domain wall (boundary between regions of different magnetization) down...

  1. 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.

  2. 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.

  3. Magnetic bead detection using domain wall-based nanosensor

    SciTech Connect (OSTI)

    Corte-León, H.; Krzysteczko, P.; Schumacher, H. W.; Manzin, A.; Cox, D.; Antonov, V.; Kazakova, O.

    2015-05-07

    We investigate the effect of a single magnetic bead (MB) on the domain wall (DW) pinning/depinning fields of a DW trapped at the corner of an L-shaped magnetic nanodevice. DW propagation across the device is investigated using magnetoresistance measurements. DW pinning/depinning fields are characterized in as-prepared devices and after placement of a 1 μm-sized MB (Dynabeads{sup ®} MyOne{sup ™}) at the corner. The effect of the MB on the DW dynamics is seen as an increase in the depinning field for specific orientations of the device with respect to the external magnetic field. The shift of the depinning field, ΔB{sub dep} = 4.5–27.0 mT, is highly stable and reproducible, being significantly above the stochastic deviation which is about 0.5 mT. The shift in the deppinning field is inversely proportional to the device width and larger for small negative angles between the device and the external magnetic field. Thus, we demonstrate that DW-based devices can be successfully used for detection of single micron size MB.

  4. Magnetic soft x-ray microscopy of the domain wall depinning process...

    Office of Scientific and Technical Information (OSTI)

    Magnetic soft x-ray microscopy of the domain wall depinning process in permalloy magnetic nanowires Citation Details In-Document Search Title: Magnetic soft x-ray microscopy of the ...

  5. Magnetic soft x-ray microscopy of the domain wall depinning process in

    Office of Scientific and Technical Information (OSTI)

    permalloy magnetic nanowires (Journal Article) | SciTech Connect Magnetic soft x-ray microscopy of the domain wall depinning process in permalloy magnetic nanowires Citation Details In-Document Search Title: Magnetic soft x-ray microscopy of the domain wall depinning process in permalloy magnetic nanowires Authors: Im, Mi-Young ; Bocklage, Lars ; Meier, Guido ; Fischer, Peter Publication Date: 2011-10-27 OSTI Identifier: 1172969 Report Number(s): LBNL-5866E DOE Contract Number:

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

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

    Vortices Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic Vortices Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic Vortices Print Wednesday, 27 August 2008 00:00 Soft magnetic, micron-sized thin-film structures with magnetic vortices are intriguing systems that may one day be used in ultrafast computer memories. In such systems, the otherwise in-plane magnetization turns perpendicular to the plane at the center of the vortex, forming the vortex core.

  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. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    while. Such is the dream for novel magnetic data storage devices included under the umbrella of "spintronics," a technology based on using the electron's quantum-mechanical spin...

  9. 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 ...

  10. 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...

  11. Stability of a pinned magnetic domain wall as a function of its internal configuration

    SciTech Connect (OSTI)

    Montaigne, F.; Duluard, A.; Briones, J.; Lacour, D.; Hehn, M.; Childress, J. R.

    2015-01-14

    It is shown that there are many stable configurations for a domain wall pinned by a notch along a magnetic stripe. The stability of several of these configurations is investigated numerically as a function of the thickness of the magnetic film. The depinning mechanism depends on the structure of the domain wall and on the thickness of the magnetic film. In the case of a spin-valve structure, it appears that the stray fields emerging from the hard layer at the notch location influence the stability of the micromagnetic configuration. Different depinning mechanisms are thus observed for the same film thickness depending on the magnetization orientation of the propagating domain. This conclusion qualitatively explains experimental magnetoresistance measurements.

  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)

    Vortices Influence of Domain Wall Pinning 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 ultrafast computer memories. In such systems, the otherwise in-plane magnetization turns perpendicular to the plane at the center of the vortex, forming the vortex core. Because such a core has two possible polarizations (up or down) and can be switched between these two states

  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)

    Vortices Influence of Domain Wall Pinning 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 ultrafast computer memories. In such systems, the otherwise in-plane magnetization turns perpendicular to the plane at the center of the vortex, forming the vortex core. Because such a core has two possible polarizations (up or down) and can be switched between these two states

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

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

    Vortices Influence of Domain Wall Pinning 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 ultrafast computer memories. In such systems, the otherwise in-plane magnetization turns perpendicular to the plane at the center of the vortex, forming the vortex core. Because such a core has two possible polarizations (up or down) and can be switched between these two states

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

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

    Vortices Influence of Domain Wall Pinning 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 ultrafast computer memories. In such systems, the otherwise in-plane magnetization turns perpendicular to the plane at the center of the vortex, forming the vortex core. Because such a core has two possible polarizations (up or down) and can be switched between these two states

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

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

    Vortices Influence of Domain Wall Pinning 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 ultrafast computer memories. In such systems, the otherwise in-plane magnetization turns perpendicular to the plane at the center of the vortex, forming the vortex core. Because such a core has two possible polarizations (up or down) and can be switched between these two states

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

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

    Vortices Influence of Domain Wall Pinning 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 ultrafast computer memories. In such systems, the otherwise in-plane magnetization turns perpendicular to the plane at the center of the vortex, forming the vortex core. Because such a core has two possible polarizations (up or down) and can be switched between these two states

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

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

    Vortices Influence of Domain Wall Pinning 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 ultrafast computer memories. In such systems, the otherwise in-plane magnetization turns perpendicular to the plane at the center of the vortex, forming the vortex core. Because such a core has two possible polarizations (up or down) and can be switched between these two states

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Axion domain wall baryogenesis

    SciTech Connect (OSTI)

    Daido, Ryuji; Kitajima, Naoya; Takahashi, Fuminobu

    2015-07-28

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m≃10{sup 8}–10{sup 13} GeV and f≃10{sup 13}–10{sup 16} GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

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

    Office of Scientific and Technical Information (OSTI)

    motion in declamped tetragonal lead zirconate titanate thin films (Journal Article) | DOE PAGES Publisher's Accepted Manuscript: In situ measurement of increased ferroelectric/ferroelastic domain wall motion in declamped tetragonal lead zirconate titanate thin films « Prev Next » Title: In situ measurement of increased ferroelectric/ferroelastic domain wall motion in declamped tetragonal lead zirconate titanate thin films Authors: Wallace, M. [1] Search DOE PAGES for author "Wallace,

  5. 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

  6. Depinning transition of a domain wall in ferromagnetic films

    SciTech Connect (OSTI)

    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 and conventional Arrhenius-type DW motions.

  7. 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.

  8. 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.

  9. Evolution of domain wall networks: The Press-Ryden-Spergel algorithm

    SciTech Connect (OSTI)

    Sousa, L.; Avelino, P. P.

    2010-04-15

    The Press-Ryden-Spergel (PRS) algorithm is a modification to the field theory equations of motion, parametrized by two parameters ({alpha} and {beta}), implemented in numerical simulations of cosmological domain wall networks, in order to ensure a fixed comoving resolution. In this paper we explicitly demonstrate that the PRS algorithm provides the correct domain wall dynamics in (N+1)-dimensional Friedmann-Robertson-Walker universes if {alpha}+{beta}/2=N, fully validating its use in numerical studies of cosmic domain evolution. We further show that this result is valid for generic thin featureless domain walls, independently of the Lagrangian of the model.

  10. Standing gravitational waves from domain walls

    SciTech Connect (OSTI)

    Gogberashvili, Merab; Myrzakul, Shynaray; Singleton, Douglas

    2009-07-15

    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 nonlinear wave solutions to Einstein's equations. Additionally this solution may act as a template for higher dimensional 'brane-world' model standing waves.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

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

    Office of Scientific and Technical Information (OSTI)

    fermion calculations at 297 MeV pion mass (Conference) | SciTech Connect Conference: Nucleon transverse momentum-dependent parton distributions from domain wall fermion calculations at 297 MeV pion mass Citation Details In-Document Search Title: Nucleon transverse momentum-dependent parton distributions from domain wall fermion calculations at 297 MeV pion mass Lattice QCD calculations of transverse momentum-dependent parton distributions (TMDs) in a nucleon are performed based on a

  16. Magnetoelectric domain wall dynamics and its implications for magnetoelectric memory

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

    Belashchenko, K. D.; Tchernyshyov, O.; Kovalev, Alexey A.; Tretiakov, O. A.

    2016-03-30

    Domain wall dynamics in a magnetoelectric antiferromagnet is analyzed, and its implications for magnetoelectric memory applications are discussed. Cr2O3 is used in the estimates of the materials parameters. It is found that the domain wall mobility has a maximum as a function of the electric field due to the gyrotropic coupling induced by it. In Cr2O3, the maximal mobility of 0.1 m/(s Oe) is reached at E≈0.06 V/nm. Fields of this order may be too weak to overcome the intrinsic depinning field, which is estimated for B-doped Cr2O3. These major drawbacks for device implementation can be overcome by applying amore » small in-plane shear strain, which blocks the domain wall precession. Domain wall mobility of about 0.7 m/(s Oe) can then be achieved at E = 0.2 V/nm. Furthermore, a split-gate scheme is proposed for the domain-wall controlled bit element; its extension to multiple-gate linear arrays can offer advantages in memory density, programmability, and logic functionality.« less

  17. Fast strain wave induced magnetization changes in long cobalt bars: Domain motion versus coherent rotation

    SciTech Connect (OSTI)

    Davis, S.; Adenwalla, S.; Borchers, J. A.; Maranville, B. B.

    2015-02-14

    A high frequency (88 MHz) traveling strain wave on a piezoelectric substrate is shown to change the magnetization direction in 40 μm wide Co bars with an aspect ratio of 10{sup 3}. The rapidly alternating strain wave rotates the magnetization away from the long axis into the short axis direction, via magnetoelastic coupling. Strain-induced magnetization changes have previously been demonstrated in ferroelectric/ferromagnetic heterostructures, with excellent fidelity between the ferromagnet and the ferroelectric domains, but these experiments were limited to essentially dc frequencies. Both magneto-optical Kerr effect and polarized neutron reflectivity confirm that the traveling strain wave does rotate the magnetization away from the long axis direction and both yield quantitatively similar values for the rotated magnetization. An investigation of the behavior of short axis magnetization with increasing strain wave amplitude on a series of samples with variable edge roughness suggests that the magnetization reorientation that is seen proceeds solely via coherent rotation. Polarized neutron reflectivity data provide direct experimental evidence for this model. This is consistent with expectations that domain wall motion cannot track the rapidly varying strain.

  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. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    walls and opens a path to further technological developments in spintronics applications. ... included under the umbrella of "spintronics," a technology based on using the ...

  20. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    today's spinning disk, such a dialog could become ancient history. Not only that, the computer could hold more information, retrieve it more quickly, and consume less power all the...

  1. Stochastic Domain-Wall Depinning in Magnetic Nanowires

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

    moving parts, in contrast to today's spinning disk, such a dialog could become ancient history. Not only that, the computer could hold more information, retrieve it more...

  2. 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.

  3. 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.

  4. 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.

  5. Gravitational waves from domain walls in the next-to-minimal supersymmetric standard model

    SciTech Connect (OSTI)

    Kadota, Kenji; Kawasaki, Masahiro; Saikawa, Ken’ichi

    2015-10-16

    The next-to-minimal supersymmetric standard model predicts the formation of domain walls due to the spontaneous breaking of the discrete Z{sub 3}-symmetry at the electroweak phase transition, and they collapse before the epoch of big bang nucleosynthesis if there exists a small bias term in the potential which explicitly breaks the discrete symmetry. Signatures of gravitational waves produced from these unstable domain walls are estimated and their parameter dependence is investigated. It is shown that the amplitude of gravitational waves becomes generically large in the decoupling limit, and that their frequency is low enough to be probed in future pulsar timing observations.

  6. Current induced perpendicular-magnetic-anisotropy racetrack memory with magnetic field assistance

    SciTech Connect (OSTI)

    Zhang, Y.; Klein, J.-O.; Chappert, C.; Ravelosona, D.; Zhao, W. S.

    2014-01-20

    High current density is indispensable to shift domain walls (DWs) in magnetic nanowires, which limits the using of racetrack memory (RM) for low power and high density purposes. In this paper, we present perpendicular-magnetic-anisotropy (PMA) Co/Ni RM with global magnetic field assistance, which lowers the current density for DW motion. By using a compact model of PMA RM and 40 nm design kit, we perform mixed simulation to validate the functionality of this structure and analyze its density potential. Stochastic DW motion behavior has been taken into account and statistical Monte-Carlo simulations are carried out to evaluate its reliability performance.

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

    SciTech Connect (OSTI)

    Jun, Su-Hyeong; Shim, Je-Ho; Oh, Suhk-Kun; Yu, Seong-Cho; Kim, Dong-Hyun; Mesler, Brooke; Fischer, Peter

    2009-07-05

    We have investigated a coupled motion of two vortex cores in ferromagnetic/nonmagnetic/ferromagnetic trilayer cynliders by means of micromagnetic simulation. Dynamic motion of two vortex with parallel and antiparallel relative chiralities of curling spins around the vortex cores have been examined after excitation by 1-ns pulsed external field. With systematic variation in non-magnetic spacer layer thickness from 0 to 20 nm, the coupling between two cores becomes significant as the spacer becomes thinner. Significant coupling leads to a nonlinear chaotic coupled motion of two vortex cores for the parallel chiralities and a faster coupled gyrotropic oscillation for the antiparallel chiralities.

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

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect f{sub K}/f{sub {pi}} in full QCD with domain wall valence quarks Citation Details In-Document Search Title: f{sub K}/f{sub {pi}} in full QCD with domain wall valence quarks We compute the ratio of pseudoscalar decay constants f{sub K}/f{sub {pi}} using domain-wall valence quarks and rooted improved Kogut-Susskind sea quarks, at a lattice spacing of b{approx}0.125 fm. By employing continuum chiral perturbation theory, we extract the Gasser-Leutwyler low-energy

  9. Axial couplings of heavy hadrons from domain-wall lattice QCD

    SciTech Connect (OSTI)

    W. Detmold, C.J.D. Lin, S. Meinel

    2011-12-01

    We calculate matrix elements of the axial current for static-light mesons and baryons in lattice QCD with dynamical domain wall fermions. We use partially quenched heavy hadron chiral perturbation theory in a finite volume to extract the axial couplings g{sub 1}, g{sub 2}, and g{sub 3} from the data. These axial couplings allow the prediction of strong decay rates and enter chiral extrapolations of most lattice results in the b sector. Our calculations are performed with two lattice spacings and with pion masses down to 227 MeV.

  10. Cosmic bubble and domain wall instabilities II: fracturing of colliding walls

    SciTech Connect (OSTI)

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

    2015-08-26

    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.

  11. Magnetic dipole excitations in nuclei: Elementary modes of nucleonic motion

    SciTech Connect (OSTI)

    Heyde, Kris; Neumann-Cosel, Peter von; Richter, Achim

    2010-07-15

    The nucleus is one of the most multifaceted many-body systems in the Universe. It exhibits a multitude of responses depending on the way one ''probes'' it. With increasing technical advancements of beams at the various accelerators and of detection systems the nucleus has, over and over again, surprised us by expressing always new ways of ''organized'' structures and layers of complexity. Nuclear magnetism is one of those fascinating faces of the atomic nucleus discussed in the present review. We shall not just limit ourselves to presenting the by now large data set that has been obtained in the past two decades using various probes, electromagnetic and hadronic alike and that presents ample evidence for a low-lying orbital scissors mode around 3 MeV, albeit fragmented over an energy interval of the order of 1.5 MeV, and higher-lying spin-flip strength in the energy region 5-9 MeV in deformed nuclei nor to the presently discovered evidence for low-lying proton-neutron isovector quadrupole excitations in spherical nuclei. To the contrary, the experimental evidence is put in the perspectives of understanding the atomic nucleus and its various structures of well-organized modes of motion and thus enlarges the discussion to more general fermion and bosonic many-body systems.

  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)

    B. Van Waeyenberge (Ghent University, Belgium), K.W. Chou, H. Stoll, M. Curcic, G. Schutz (Max Planck Institute for Metals Research, Germany), T. Tyliszczak (ALS), G....

  13. An in-situ study of magnetic domain structures in undercooled Fe-29.5 at. %Pd magnetostrictive alloys by Lorentz microscopy and electron holography

    SciTech Connect (OSTI)

    Sun, Wen; Xu, Xianhui; Liu, Jian E-mail: xiawxing@nimte.ac.cn; Xia, Weixing E-mail: xiawxing@nimte.ac.cn; Yan, Aru

    2015-04-28

    Understanding of correlation between magnetic domain structure and functional properties is of importance for the magnetic field driven phase transition (e.g., martensitic transformation) or microstructure variation (e.g., twin boundary motion) materials. In this work, we report a Fe-29.5 at. %Pd shape memory alloy treated by undercooling processing upon a degree of 320?K below the liquid temperature. The effect of high undercooling on the solidified microstructure and martensitic transformation temperatures was investigated. By in-situ Lorentz transmission electron microscopy and electron holography, magnetic domain structure and the field-induced domain wall motion behavior in as-cast and undercooled samples have been schematically studied. The irregular domain structure can be observed in these alloys. On the application of a field up to 300?Oe, the domain walls for both samples are able to move along the direction of the external magnetic field, but structural transition and rearrangement of variants are not observed in the undercooled alloy. The large magnetostriction of Fe-29.5 at. %Pd undercooled alloy originates from the irregular domain walls motion instead of the rearrangement of martensitic twin variants.

  14. Nucleon transverse momentum-dependent parton distributions from domain wall fermion calculations at 297 MeV pion mass

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

    Engelhardt, M.; Musch, B.; Bhattacharya, T.; Gupta, R.; Hagler, P.; Negele, J.; Pochinsky, A.; Schafer, A.; Syritsyn, S.; Yoon, B.

    2014-06-23

    Here, lattice QCD calculations of transverse momentum-dependent parton distributions (TMDs) in a nucleon are performed based on a definition of TMDs via hadronic matrix elements of quark bilocal operators containing staple-shaped gauge connections. A parametrization of the matrix elements in terms of invariant amplitudes serves to cast them in the Lorentz frame preferred for the lattice calculation. Using a RBC/UKQCD domain wall fermion ensemble corresponding to a pion mass of 297 MeV, on a lattice with spacing 0.084 fm, selected TMD observables are accessed and compared to previous exploration at heavier pion masses on coarser lattices.

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

    SciTech Connect (OSTI)

    Su, Yang; Veronig, Astrid; Temmer, Manuela; Vanninathan, Kamalam; Gmry, 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 ?5kms{sup 1}.

  16. Relativistic electron motion in cylindrical waveguide with strong guiding magnetic field and high power microwave

    SciTech Connect (OSTI)

    Wu, Ping; Sun, Jun; Cao, Yibing

    2015-06-15

    In O-type high power microwave (HPM) devices, the annular relativistic electron beam is constrained by a strong guiding magnetic field and propagates through an interaction region to generate HPM. Some papers believe that the E × B drift of electrons may lead to beam breakup. This paper simplifies the interaction region with a smooth cylindrical waveguide to research the radial motion of electrons under conditions of strong guiding magnetic field and TM{sub 01} mode HPM. The single-particle trajectory shows that the radial electron motion presents the characteristic of radial guiding-center drift carrying cyclotron motion. The radial guiding-center drift is spatially periodic and is dominated by the polarization drift, not the E × B drift. Furthermore, the self fields of the beam space charge can provide a radial force which may pull electrons outward to some extent but will not affect the radial polarization drift. Despite the radial drift, the strong guiding magnetic field limits the drift amplitude to a small value and prevents beam breakup from happening due to this cause.

  17. Photon equation of motion with application to the electron's anomalous magnetic moment

    SciTech Connect (OSTI)

    Ritchie, A B

    2007-12-06

    The photon equation of motion previously applied to the Lamb shift is here applied to the anomalous magnetic moment of the electron. Exact agreement is obtained with the QED result of Schwinger. The photon theory treats the radiative correction to the photon in the presence of the electron rather than its inverse as in standard QED. The result is found to be first-order in the photon-electron interaction rather than second-order as in standard QED, introducing an ease of calculation hitherto unavailable.

  18. Neutron and proton electric dipole moments from Nf=2+1 domain-wall fermion lattice QCD

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

    Shintani, Eigo; Blum, Thomas; Izubuchi, Taku; Soni, Amarjit

    2016-05-05

    We present a lattice calculation of the neutron and proton electric dipole moments (EDM’s) with Nf = 2 + 1 flavors of domain-wall fermions. The neutron and proton EDM form factors are extracted from three-point functions at the next-to-leading order in the θ vacuum of QCD. In this computation, we use pion masses 330 and 420 MeV and 2.7 fm3 lattices with Iwasaki gauge action and a 170 MeV pion and 4.6 fm3 lattice with I-DSDR gauge action, all generated by the RBC and UKQCD collaborations. The all-mode-averaging technique enables an efficient, high statistics calculation; however the statistical errors onmore » our results are still relatively large, so we investigate a new direction to reduce them, reweighting with the local topological charge density which appears promising. Furthermore, we discuss the chiral behavior and finite size effects of the EDM’s in the context of baryon chiral perturbation theory.« less

  19. Magnetic Resonance Imaging–Guided versus Surrogate-Based Motion Tracking in Liver Radiation Therapy: A Prospective Comparative Study

    SciTech Connect (OSTI)

    Paganelli, Chiara; Seregni, Matteo; Fattori, Giovanni; Summers, Paul; Bellomi, Massimo; Baroni, Guido; Riboldi, Marco

    2015-03-15

    Purpose: This study applied automatic feature detection on cine–magnetic resonance imaging (MRI) liver images in order to provide a prospective comparison between MRI-guided and surrogate-based tracking methods for motion-compensated liver radiation therapy. Methods and Materials: In a population of 30 subjects (5 volunteers plus 25 patients), 2 oblique sagittal slices were acquired across the liver at high temporal resolution. An algorithm based on scale invariant feature transform (SIFT) was used to extract and track multiple features throughout the image sequence. The position of abdominal markers was also measured directly from the image series, and the internal motion of each feature was quantified through multiparametric analysis. Surrogate-based tumor tracking with a state-of-the-art external/internal correlation model was simulated. The geometrical tracking error was measured, and its correlation with external motion parameters was also investigated. Finally, the potential gain in tracking accuracy relying on MRI guidance was quantified as a function of the maximum allowed tracking error. Results: An average of 45 features was extracted for each subject across the whole liver. The multi-parametric motion analysis reported relevant inter- and intrasubject variability, highlighting the value of patient-specific and spatially-distributed measurements. Surrogate-based tracking errors (relative to the motion amplitude) were were in the range 7% to 23% (1.02-3.57mm) and were significantly influenced by external motion parameters. The gain of MRI guidance compared to surrogate-based motion tracking was larger than 30% in 50% of the subjects when considering a 1.5-mm tracking error tolerance. Conclusions: Automatic feature detection applied to cine-MRI allows detailed liver motion description to be obtained. Such information was used to quantify the performance of surrogate-based tracking methods and to provide a prospective comparison with respect to MRI-guided radiation therapy, which could support the definition of patient-specific optimal treatment strategies.

  20. 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.

  1. 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.

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

    SciTech Connect (OSTI)

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

    2015-03-10

    We calculate the B-meson decay constants fB, fBs, 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 Mπ ≈ 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(αsa). 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 fB0 = 196.2(15.7) MeV, fB+ = 195.4(15.8) MeV, fBs = 235.4(12.2) MeV, fBs/fB0 = 1.193(59), and fBs/fB+ = 1.220(82), where the errors are statistical and total systematic added in quadrature. In addition, 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.

  3. ALSNews Vol. 300

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

    ... This result both provides valuable insight into the motion of magnetic-domain walls and opens a path to further technological developments in spintronics applications. Read more... ...

  4. PLASMA MOTIONS AND HEATING BY MAGNETIC RECONNECTION IN A 2007 MAY 19 FLARE

    SciTech Connect (OSTI)

    Hara, Hirohisa; Watanabe, Tetsuya; Harra, Louise K.; Leonard Culhane, J.; Young, Peter R.

    2011-11-10

    Based on scanning spectroscopic observations with the Hinode EUV imaging spectrometer, we have found a loop-top hot source, a fast jet nearby, and an inflow structure flowing to the hot source that appeared in the impulsive phase of a long-duration flare at the disk center on 2007 May 19. The hot source observed in Fe XXIII and Fe XXIV emission lines has the electron temperature of 12 MK and density of 1 Multiplication-Sign 10{sup 10} cm{sup -3}. It shows excess line broadening, which exceeds the thermal Doppler width by {approx}100 km s{sup -1}, with a weak redshift of {approx}30 km s{sup -1}. We have also observed a blueshifted faint jet whose Doppler velocity exceeds 200 km s{sup -1} with an electron temperature of 9 MK. Coronal plasmas with electron temperature of 1.2 MK and density of 2.5 Multiplication-Sign 10{sup 9} cm{sup -3} that flow into the loop-top region with a Doppler velocity of 20 km s{sup -1} have been identified in the Fe XII observation. They disappeared near the hot source, possibly by being heated to the hotter faint jet temperature. From the geometrical relationships of these phenomena, we conclude that they provide evidence for magnetic reconnection that occurs near the loop-top region. The estimated reconnection rate is 0.05-0.1, which supports the Petschek-type magnetic reconnection. Further supporting evidence for the presence of the slow-mode and fast-mode MHD shocks in the reconnection geometry is given based on the observed quantities.

  5. Dynamics of charged particle motion in the vicinity of three dimensional magnetic null points: Energization and chaos

    SciTech Connect (OSTI)

    Gascoyne, Andrew

    2015-03-15

    Using a full orbit test particle approach, we analyse the motion of a single proton in the vicinity of magnetic null point configurations which are solutions to the kinematic, steady state, resistive magnetohydrodynamics equations. We consider two magnetic configurations, namely, the sheared and torsional spine reconnection regimes [E. R. Priest and D. I. Pontin, Phys. Plasmas 16, 122101 (2009); P. Wyper and R. Jain, Phys. Plasmas 17, 092902 (2010)]; each produce an associated electric field and thus the possibility of accelerating charged particles to high energy levels, i.e., > MeV, as observed in solar flares [R. P. Lin, Space Sci. Rev. 124, 233 (2006)]. The particle's energy gain is strongly dependent on the location of injection and is characterised by the angle of approach β, with optimum angle of approach β{sub opt} as the value of β which produces the maximum energy gain. We examine the topological features of each regime and analyse the effect on the energy gain of the proton. We also calculate the complete Lyapunov spectrum for the considered dynamical systems in order to correctly quantify the chaotic nature of the particle orbits. We find that the sheared model is a good candidate for the acceleration of particles, and for increased shear, we expect a larger population to be accelerated to higher energy levels. In the strong electric field regime (E{sub 0}=1500 V/m), the torsional model produces chaotic particle orbits quantified by the calculation of multiple positive Lyapunov exponents in the spectrum, whereas the sheared model produces chaotic orbits only in the neighbourhood of the null point.

  6. 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 100250?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.

  7. ALSNews Vol. 280

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

    Contents X-ray imaging current-driven magnetic domain-wall motion in nanowires ... Requests for special operations use of the "scrubbing" shift should be sent to Rick ...

  8. Magnetization Reversal Process of Single Crystal α-Fe Containing a Nonmagnetic Particle

    SciTech Connect (OSTI)

    Li, Yi; Xu, Ben; Hu, Shenyang Y.; Li, Yulan; Li, Qiu-Lin; Liu, Wei

    2015-09-25

    The magnetization reversal process and hysteresis loops in a single crystal α-iron with nonmagnetic particles are simulated in this work based on the Landau-Lifshitz–Gilbert equation. The evolutions of the magnetic domain morphology are studied, and our analyses show that the magnetization reversal process is affected by the interaction between the moving domain wall and the existing nonmagnetic particles. This interaction strongly depends on the size of the particles, and it is found that particles with a particular size contribute the most to magnetic hardening.

  9. MAGNETS

    DOE Patents [OSTI]

    Hofacker, H.B.

    1958-09-23

    This patent relates to nmgnets used in a calutron and more particularly to means fur clamping an assembly of magnet coils and coil spacers into tightly assembled relation in a fluid-tight vessel. The magnet comprises windings made up of an assembly of alternate pan-cake type coils and spacers disposed in a fluid-tight vessel. At one end of the tank a plurality of clamping strips are held firmly against the assembly by adjustable bolts extending through the adjacent wall. The foregoing arrangement permits taking up any looseness which may develop in the assembly of coils and spacers.

  10. Dielectric and magnetic investigations of GaFeO{sub 3} single crystals

    SciTech Connect (OSTI)

    Srimathy, B. Bhaumik, Indranil Ganesamoorthy, S. Karnal, A. K. Kumar, J.

    2014-04-24

    Structural, dielectric and magnetic properties have been investigated for the polar ferrimagnet, GaFeO{sub 3} single crystals grown by optical floating zone technique. Phase formation was confirmed from X-ray diffraction. Hopping conduction mechanism of Fe{sup 2+} ions and oxygen vacancies contribute to the electric polarization and dielectric constant of the material. Disorderness in the cation site gives rise to the magnetic ordering and the splitting in the zero field cooled (ZFC) and field cooled (FC) magnetization curves reveals the movement of the domain walls.

  11. 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.

  12. FINAL REPORT: FG02-01ER-45906 - A novel class of artificially modulated magnetic multilayers based on magnetic shape memory alloys

    SciTech Connect (OSTI)

    Chopra, H. D.

    2005-06-20

    The temperature dependent micromagnetic behavior, structural phase transitions, magnetic transition, and the dynamics of phase transitions have been investigated using magnetic shape memory alloys. Results provide a novel concept of ?polymagnets?. In thin film form the number of martensite variants is greatly reduced. A new technique to study dynamics of magnetic phase transitions has been developed applicable to bulk, thin films or multilayers. Transition pathways in magnetic shape memory alloys are as follows: Structural transitions followed by magnetic transition on cooling, and magnetic transition followed by structural transition on heating. The anisotropy of exchange spring mulilayers is greatly sensitive to substrate constraints, and shows a marked rotational hysteresis at lower temperatures. Results also show that a large reduction in coercivity of multilayers is a direct result of broadening of domain wall width by interlayer magnetostatic interactions.

  13. X-ray imaging of Nonlinear Resonant Gyrotropic Magnetic Vortex...

    Office of Scientific and Technical Information (OSTI)

    Vortex Core Motion in Circular Permalloy Disks Citation Details In-Document Search Title: X-ray imaging of Nonlinear Resonant Gyrotropic Magnetic Vortex Core Motion in ...

  14. 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.

  15. Imaging the magnetic nanodomains in Nd2Fe14B

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

    Huang, Lunan; Taufour, Valentin; Lamichhane, T. N.; Schrunk, Benjamin; Bud'ko, Sergei L.; Canfield, P. C.; Kaminski, Adam

    2016-03-08

    Here, we study magnetic domains in Nd2Fe14B single crystals using high resolution magnetic force microscopy (MFM). Previous MFM studies and small angle neutron scattering experiments suggested the presence of nanoscale domains in addition to optically detected micrometer-scale ones. We find, in addition to the elongated, wavy nanodomains reported by a previous MFM study, that the micrometer-sized, star-shaped fractal pattern is constructed of an elongated network of nanodomains ~20 nm in width, with resolution-limited domain walls thinner than 2 nm. While the microscopic domains exhibit significant resilience to an external magnetic field, some of the nanodomains are sensitive to the magneticmore » field of the MFM tip.« less

  16. The effect of boron doping on crystal structure, magnetic properties and magnetocaloric effect of DyCo2

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

    Wang, C. L.; Liu, J.; Mudryk, Y.; Gschneidner, Jr., K. A.; Long, Y.; Pecharsky, V. K.

    2015-12-19

    In this study, the magnetic properties and magnetic entropy changes of DyCo2Bx (x=0, 0.05, 0.1, and 0.2) alloys were investigated. The Curie temperature (TC) increases with increasing B concentration. The frequency dependence of ac magnetic susceptibility of DyCo2 caused by the narrow domain wall pinning effect is depressed by B doping, but the coercivity and the magnetic viscosity are prominently increased in the B doped alloys. The magnetic transition nature of DyCo2Bx changes from the first-order to the second-order with increasing x, which leads to the decrease of the maximum magnetic entropy change. However, the relative cooling power (RCP) ofmore » DyCo2 and the B doped alloys remains nearly constant.« less

  17. The effect of boron doping on crystal structure, magnetic properties and magnetocaloric effect of DyCo2

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

    Wang, C. L.; Liu, J.; Mudryk, Y.; Gschneidner, Jr., K. A.; Long, Y.; Pecharsky, V. K.

    2015-12-19

    The magnetic properties and magnetic entropy changes of DyCo2Bx (x=0, 0.05, 0.1, and 0.2) alloys were investigated. The Curie temperature (TC) increases with increasing B concentration. The frequency dependence of ac magnetic susceptibility of DyCo2 caused by the narrow domain wall pinning effect is depressed by B doping, but the coercivity and the magnetic viscosity are prominently increased in the B doped alloys. The magnetic transition nature of DyCo2Bx changes from the first-order to the second-order with increasing x, which leads to the decrease of the maximum magnetic entropy change. Furthermore, the relative cooling power (RCP) of DyCo2 and themore » B doped alloys remains nearly constant.« less

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

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

    Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL) Lausanne 1015, Switzerland CNMS D D I I S S C C O O V V E E R R Y Y SEMINAR SERIES Abstract: A ferroelectric...

  19. Dynamic domain walls in a Maxwell-dilaton background (Journal...

    Office of Scientific and Technical Information (OSTI)

    10.1103PhysRevD.78.084008; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA) Country of Publication: United States Language: ...

  20. Sandia Motion Measurement Processor

    Energy Science and Technology Software Center (OSTI)

    2003-03-01

    SANDIA-MMP is used to estimate the motion of the belly and wing pods of an aircraft given various indirect in-flight measurements.

  1. 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.

  2. Influence of microstructural changes due to tempering at 923 K and 1,023 K on magnetic Barkhausen noise behavior in normalized 2.25Cr-1Mo ferritic steel

    SciTech Connect (OSTI)

    Raj, B.; Moorthy, V.; Vaidyanathan, S.

    1997-01-01

    Magnetic Barkhausen noise analysis has been used to characterize the microstructural changes in normalized and tempered 2.25 Cr-1Mo steel. It is observed that tempering at 923 K shows a single peak behavior up to 20 h and tempering at 1,023 K shows a two peak behavior. This has been explained on the basis of the two stage process of irreversible domain wall movement during magnetization, associated with two major obstacles to domain wall movement: namely lath/grain boundaries and secondary phase precipitates. At lower fields, existing reverse domain walls at lath/grain boundaries overcome the resistance offered by the grain boundaries and move to a distance before they are pined by the precipitates. Then, at higher field, they overcome these precipitates. These two processes occur over a range of critical field strengths with some mean values. If these two mean values are close to each other, then a single peak in the rms voltage of the magnetic Barkhausen noise, with the associated changes in its shape, is observed. On the other hand, if the mean values of the critical fields for these two barriers are widely separated, then a two peak behavior is the clear possibility. The effect of the microstructural changes due to tempering for different durations at 923 K and 1,023 K in 2.25 Cr-1Mo ferritic steel on magnetic Barkhausen noise is explained based on these two stage processes. The influence of high dislocation density in bainitic structure, dissociation of bainite, and precipitation of different carbides such as Fe{sub 3}C, Mo{sub 2}C, Cr{sub 7}Ce{sub 3}, M{sub 23}C{sub 6}, etc., on magnetic Barkhausen noise behavior has been analyzed in this study.

  3. DOE Opposes Injunction Motion

    Broader source: Energy.gov [DOE]

    On April 23, 2010, the Department of Energy opposed the State of Washington’s motion to enjoin the Department's efforts to wind down the Yucca Mountain Program. The Department's filing, made in the...

  4. 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).

  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. Intrinsic Feature Motion Tracking

    Energy Science and Technology Software Center (OSTI)

    2013-03-19

    Subject motion during 3D medical scanning can cause blurring and artifacts in the 3D images resulting in either rescans or poor diagnosis. Anesthesia or physical restraints may be used to eliminate motion but are undesirable and can affect results. This software measures the six degree of freedom 3D motion of the subject during the scan under a rigidity assumption using only the intrinsic features present on the subject area being monitored. This movement over timemore » can then be used to correct the scan data removing the blur and artifacts. The software acquires images from external cameras or images stored on disk for processing. The images are from two or three calibrated cameras in a stereo arrangement. Algorithms extract and track the features over time and calculate position and orientation changes relative to an initial position. Output is the 3D position and orientation change measured at each image.« less

  7. Soft X-ray techniques to study mesoscale magnetism

    SciTech Connect (OSTI)

    Kortright, Jeffrey B.

    2003-06-26

    Heterogeneity in magnetization (M) is ubiquitous in modern systems. Even in nominally homogeneous materials, domains or pinning centers typically mediate magnetization reversal. Fundamental lengths determining M structure include the domain wall width and the exchange stiffness length, typically in the 4-400 nm range. Chemical heterogeneity (phase separation, polycrystalline microstructure, lithographic or other patterning, etc.) with length scales from nanometers to microns is often introduced to influence magnetic properties. With 1-2 nm wavelengths {lambda}, soft x-rays in principle can resolve structure down to {lambda}/2, and are well suited to study these mesoscopic length scales [1, 2]. This article highlights recent advances in resonant soft x-ray methods to resolve lateral magnetic structure [3], and discusses some of their relative merits and limitations. Only techniques detecting x-ray photons (rather than photo-electrons) are considered [4], since they are compatible with strong applied fields to probe relatively deeply into samples. The magneto-optical (MO) effects discovered by Faraday and Kerr were observed in the x-ray range over a century later, first at ''hard'' wavelengths in diffraction experiments probing interatomic magnetic structure [5]. In the soft x-ray range, magnetic linear [6] and circular [7] dichroism spectroscopies first developed that average over lateral magnetic structure. These large resonant MO effects enable different approaches to study magnetic structure or heterogeneity that can be categorized as microscopy or scattering [1]. Direct images of magnetic structure result from photo-emission electron microscopes [4, 8] and zone-plate microscopes [9, 10]. Scattering techniques extended into the soft x-ray include familiar specular reflection that laterally averages over structure but can provide depth-resolved information, and diffuse scattering and diffraction that provide direct information about lateral magnetic structure. Scattering techniques are further classified as partially for fully coherent according to the extent of transverse coherence of the incident beam.

  8. Lifshitz metal–insulator transition induced by the all-in/all-out magnetic order in the pyrochlore oxide Cd{sub 2}Os{sub 2}O{sub 7}

    SciTech Connect (OSTI)

    Hiroi, Z. Hirose, T.; Nagashima, I.; Okamoto, Y.; Yamaura, J.

    2015-04-01

    We investigate the metal–insulator transition (MIT) of the osmium pyrochlore oxide Cd{sub 2}Os{sub 2}O{sub 7} through transport and magnetization measurements. The MIT and a magnetic transition to the all-in/all-out (AIAO) order occur simultaneously at 227 K. We propose a mechanism based on a Lifshitz transition induced by the AIAO magnetic order probably via strong spin–orbit couplings in the specific semimetallic band structure. It is suggested, moreover, that two observed puzzles, a finite conductivity near T = 0 and an emergence of weak ferromagnetic moments, are not bulk properties but originate at magnetic domain walls between two kinds of AIAO domains.

  9. Imaging of magnetic DW injection processed in patterened Ni80Fe20 structures

    SciTech Connect (OSTI)

    Bryan, M. T.; Basu, S.; Fry, P. W.; Schrefl, T.; Gibbs, M.R.J.; Allwood, D. A.; Im, M.-Y.; Fischer, P.

    2009-03-23

    Magnetization reversal in patterned ferromagnetic nanowires usually occurs via domain wall (DW) nucleation and propagation from one end (or both ends) of the wire which can be significantly reduced by a large, magnetically soft pad on one of the wire ends. These 'nucleation pads' reverse at lower fields than an isolated nanowire and introduce a DW to the wire from the wire end attached to the pad. Once a critical 'injection' field is reached, the DW sweeps through the wire, reversing its magnetization. Nucleation pads are frequently used as part of nanowire devices and experimental structures. Magnetic-field-driven shift register memory can include an injection pad to write data while those attached to nanowire spiral turn sensors act as both a source and sink of domain walls. Both of these devices use two-dimensional wire circuits and therefore require the use of orthogonal in-plane magnetic fields to drive domain walls through wires of different orientations. These bi-axial fields can significantly alter the fields at which DW injection occurs and control the number of different injection modes. We have used magnetic transmission soft X-ray microscopy (M-TXM) [6] providing 25nm spatial resolution to image the evolution of magnetization configurations in patterned 24nm thick Ni{sub 80}Fe{sub 20} rectangular nucleation pads and attached wires during DW injection. The structures consisted of 2 {micro}m x 3 {micro}m nucleation pads with wires of width 200 nm, 300 nm or 500 nm attached Comparing the magnetic configuration of the injection pads with micromagnetic models, we find that the relative orientation of closure domains in the remanent magnetization configuration of injection pads determines the reversal pathway that follows, although this is further affected by applied transverse fields. Micromagnetic simulations were performed using a hybrid finite element/boundary element code. The magnetic elements were designed with 20 nm thickness and discretized into a mesh of tetrahedral elements with a maximum cell size of 20 nm. Material properties for bulk permalloy were used, i.e. exchange stiffness A = 1.3 x 10{sup -11} J/m, saturation magnetization M{sub S} = 800 kA/m, magneto-crystalline anisotropy K = 0 Jm{sup -3}, damping constant a = 0.01. A linearly increasing magnetic field (1 Oe/ns) was applied parallel to the wire long axis to simulate switching fields. The dimensions of the simulated structures mimicked the essential features of the experimental structures, although edge roughness was neglected from the model. The remanent magnetization state of the pad with no transverse field consists of a uniform magnetization aligned with the wire axis, with closure domains at the edges facing and joining the wire. When H{sub y} = 0 Oe and H{sub x} = 20 Oe, the magnetization state of the pad buckles, forming eight domains, half of which have magnetizations rotated away from the x-axis. As H{sub x} is increased, the rotation of the domains become larger and the non-rotated domains shrink A transverse field applied in addition to the axial field exhibits a more complex modes of magnetization reversal in the pad (Fig. 1). We understand the pathway of pad magnetization more generally by using micromagnetic simulations. Two initial configurations are shown in Fig. 2 with the closure domain on the left-hand edge of the pad either parallel or anti-parallel to both closure domains on the righthand edges of the pad. As H{sub x} is increased to inject a domain wall, the pad magnetization states changed to vortex states, as observed by M-TXM. At higher fields, the magnetization of the modeled pad became single-domain, although closure domains remained at fields up to H{sub x} = 90 Oe. This supports the suggestion that experimentally observed multi-modal injection is due to the magnetization state of the pad. In summary, the relative orientation of closure domains in the pads determines the magnetization reversal pathway under an axial field. However, the addition of transverse fields can alter these and lead to the pads undergoing reversal under lower axial fields. Our observations have wider implications for experiments and devices using patterned magnetic wires.

  10. 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.

  11. Blue Motion Energy | Open Energy Information

    Open Energy Info (EERE)

    Motion Energy Jump to: navigation, search Name: Blue Motion Energy Region: Netherlands Sector: Marine and Hydrokinetic Website: http: This company is listed in the Marine and...

  12. A nonlinear piezoelectric energy harvester for various mechanical motions

    SciTech Connect (OSTI)

    Fan, Kangqi; Chang, Jianwei; Liu, Zhaohui; Zhu, Yingmin; Pedrycz, Witold

    2015-06-01

    This study presents a nonlinear piezoelectric energy harvester with intent to scavenge energy from diverse mechanical motions. The harvester consists of four piezoelectric cantilever beams, a cylindrical track, and a ferromagnetic ball, with magnets integrated to introduce the magnetic coupling between the ball and the beams. The experimental results demonstrate that the harvester is able to collect energy from various directions of vibrations. For the vibrations perpendicular to the ground, the maximum peak voltage is increased by 3.2 V and the bandwidth of the voltage above 4 V is increased by more than 4 Hz compared to the results obtained when using a conventional design. For the vibrations along the horizontal direction, the frequency up-conversion is realized through the magnetic coupling. Moreover, the proposed design can harvest energy from the sway motion around different directions on the horizontal plane. Harvesting energy from the rotation motion is also achieved with an operating bandwidth of approximately 6 Hz.

  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; Mahale, Narayan K.

    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. Piezoelectric step-motion actuator

    DOE Patents [OSTI]

    Mentesana; Charles P.

    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.

  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. Validity of equation-of-motion approach to kondo problem in the large N

    Office of Scientific and Technical Information (OSTI)

    limit (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Validity of equation-of-motion approach to kondo problem in the large N limit Citation Details In-Document Search Title: Validity of equation-of-motion approach to kondo problem in the large N limit The Anderson impurity model for Kondo problem is investigated for arbitrary orbit-spin degeneracy N of the magnetic impurity by the equation of motion method (EOM). By employing a new decoupling scheme, a

  18. Radiation camera motion correction system

    DOE Patents [OSTI]

    Hoffer, P.B.

    1973-12-18

    The device determines the ratio of the intensity of radiation received by a radiation camera from two separate portions of the object. A correction signal is developed to maintain this ratio at a substantially constant value and this correction signal is combined with the camera signal to correct for object motion. (Official Gazette)

  19. Household magnets

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

    Household magnets Chances are very good that you have experimented with magnets. People have been fascinated with magnetism for thousands of years. As familiar to us as they may be, magnets still have some surprises for us. Here is a small collection of some of our favorite magnet experiments. What happens when we break a magnet in half? Radio Shack sells cheap ceramic magnets in several shapes. Get a ring shaped magnet and break it with pliers or a tap with a hammer. Try to put it back

  20. X-ray imaging of Nonlinear Resonant Gyrotropic Magnetic Vortex...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: X-ray imaging of Nonlinear Resonant Gyrotropic Magnetic Vortex Core Motion in Circular Permalloy Disks Citation Details In-Document Search Title: X-ray imaging of ...

  1. Dynamic Switching of the Spin Circulation in Tapered Magnetic...

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

    which allows to record an image of the in-plane circulation of the magnetic vortex. The topology of vortices-areas where there is a spinning motion around an imaginary axis-is a...

  2. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    polarization. In this experiment, the researchers applied a small (0.1-mT) sinusoidal magnetic field to induce gyrotropic motion in a square Permalloy (Ni80Fe20) sample. The...

  3. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    Have feedback or suggestions for a way to improve these results? In situ measurement of increased ferroelectricferroelastic domain wall motion in declamped tetragonal lead ...

  4. Guarded Motion for Mobile Robots

    Energy Science and Technology Software Center (OSTI)

    2005-03-30

    The Idaho National Laboratory (INL) has created codes that ensure that a robot will come to a stop at a precise, specified distance from any obstacle regardless of the robot's initial speed, its physical characteristics, and the responsiveness of the low-level motor control schema. This Guarded Motion for Mobile Robots system iteratively adjusts the robot's action in response to information about the robot's environment.

  5. Collective cell motion | Argonne National Laboratory

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

    Collective cell motion Share Topic Programs Materials science Materials simulation & theory Mathematics, computing, & computer science Modeling, simulation, & visualization Over ...

  6. 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.

  7. MOTIONS OF HARD X-RAY SOURCES DURING AN ASYMMETRIC ERUPTION

    SciTech Connect (OSTI)

    Liu Chang; Jing Ju; Liu Rui; Deng Na; Wang Haimin; Lee, Jeongwoo

    2010-10-01

    Filament eruptions and hard X-ray (HXR) source motions are commonly observed in solar flares, which provide critical information on the coronal magnetic reconnection. This Letter reports an event on 2005 January 15, in which we found an asymmetric filament eruption and a subsequent coronal mass ejection together with complicated motions of HXR sources during the GOES-class X2.6 flare. The HXR sources initially converge to the magnetic polarity inversion line (PIL), and then move in directions either parallel or perpendicular to the PIL depending on the local field configuration. We distinguish the evolution of the HXR source motion in four phases and associate each of them with distinct regions of coronal magnetic fields as reconstructed using a nonlinear force-free field extrapolation. It is found that the magnetic reconnection proceeds along the PIL toward the regions where the overlying field decreases with height more rapidly. It is also found that not only the perpendicular but the parallel motion of the HXR sources correlates well with the HXR light curve. These results are discussed in favor of the torus instability as an important factor in the eruptive process.

  8. Domain walls in a Born-Infeld-dilaton background (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    10.1103PhysRevD.78.084023; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA) Country of Publication: United States Language: ...

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

    Office of Scientific and Technical Information (OSTI)

    Report Number(s): LBNL--50255 R&D Project: PTHOPS; TRN: US0502453 DOE Contract Number: AC03-76SF00098 Resource Type: Journal Article Resource Relation: Journal Name: Physical ...

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

    SciTech Connect (OSTI)

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

    2015-03-03

    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. In particular, we demonstrate that a large degree of asymmetry develops over time from tiny initial fluctuations superposed upon planar and SO(2,1) symmetric backgrounds. These fluctuations are inevitable consequences of zero-point vacuum oscillations, so excluding them by enforcing a high degree of spatial symmetry is inconsistent in a quantum treatment. To simplify the analysis we consider the limit of two colliding planar walls, with mode functions for the fluctuations characterized by the wavenumber transverse to the collision direction and a longitudinal shape along the collision direction x, which we solve for. In the linear regime, the fluctuations obey a linear wave equation with a time- and space-dependent mass m{sub eff}(x,t). In situations where the walls collide multiple times, m{sub eff} oscillates in time. We use Floquet theory to study the evolution of the fluctuations and generalize the calculations familiar from the preheating literature to the case with many coupled degrees of freedom. The inhomogeneous case has bands of unstable transverse wavenumbers k{sub ⊥} whose corresponding mode functions grow exponentially. By examining the detailed spatial structure of the mode functions in x, we identify both broad and narrow parametric resonance generalizations of the homogeneous m{sub eff}(t) case of preheating. The unstable k{sub ⊥} modes are longitudinally localized, yet can be described as quasiparticles in the Bogoliubov sense. We define an effective occupation number and 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 that will be studied in subsequent papers.

  11. 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 Fsica, 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 Alfvn 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 Alfvn wave.

  12. 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.

  13. Mineral Magnetism

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

    Mineral Magnetism 1663 Los Alamos science and technology magazine Latest Issue:March 2016 past issues All Issues » submit Mineral Magnetism By understanding what makes a material magnetic, scientists want to create new strongly magnetic materials that don't rely on hard-to-get precursor elements. March 8, 2016 Small piles of rare earth elements In the United States, rare-earth elements used in strong magnets, such as neodymium and samarium, are scarce due to limits on foreign sources. CREDIT:

  14. 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 Alfvn 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 Alfvn wave turbulence are sufficient to explain the observed hot loops. The higher heating rates are due to the amplification of Alfvn waves in the lower atmosphere. We conclude that magnetic braiding is a highly dynamic process.

  15. GENERATION OF MAGNETOHYDRODYNAMIC WAVES IN LOW SOLAR ATMOSPHERIC FLUX TUBES BY PHOTOSPHERIC MOTIONS

    SciTech Connect (OSTI)

    Mumford, S. J.; Fedun, V.; Erdlyi, R.

    2015-01-20

    Recent ground- and space-based observations reveal the presence of small-scale motions between convection cells in the solar photosphere. In these regions, small-scale magnetic flux tubes are generated via the interaction of granulation motion and the background magnetic field. This paper studies the effects of these motions on magnetohydrodynamic (MHD) wave excitation from broadband photospheric drivers. Numerical experiments of linear MHD wave propagation in a magnetic flux tube embedded in a realistic gravitationally stratified solar atmosphere between the photosphere and the low choromosphere (above ? = 1) are performed. Horizontal and vertical velocity field drivers mimic granular buffeting and solar global oscillations. A uniform torsional driver as well as Archimedean and logarithmic spiral drivers mimic observed torsional motions in the solar photosphere. The results are analyzed using a novel method for extracting the parallel, perpendicular, and azimuthal components of the perturbations, which caters to both the linear and non-linear cases. Employing this method yields the identification of the wave modes excited in the numerical simulations and enables a comparison of excited modes via velocity perturbations and wave energy flux. The wave energy flux distribution is calculated to enable the quantification of the relative strengths of excited modes. The torsional drivers primarily excite Alfvn modes (?60% of the total flux) with small contributions from the slow kink mode, and, for the logarithmic spiral driver, small amounts of slow sausage mode. The horizontal and vertical drivers primarily excite slow kink or fast sausage modes, respectively, with small variations dependent upon flux surface radius.

  16. 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.

  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. 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.

  19. 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.

  20. Magnetic shielding

    DOE Patents [OSTI]

    Kerns, John A.; Stone, Roger R.; Fabyan, Joseph

    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.

  1. Materials/Condensed Matter

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

    ... Influence of Domain Wall Pinning on the Dynamic Behavior of Magnetic Vortices Electric Field Control of ... A New Route to Nano Self-Assembly Proton Channel Orientation in ...

  2. Magnetic filtration process, magnetic filtering material, and...

    Office of Scientific and Technical Information (OSTI)

    The present invention provides magnetically responsive activated carbon, and a method of forming magnetically responsive activated carbon. The method of forming magnetically ...

  3. 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.

  4. Magnetic levitation system for moving objects

    DOE Patents [OSTI]

    Post, Richard F.

    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. Magnetic nanotubes

    DOE Patents [OSTI]

    Matsui, Hiroshi; Matsunaga, Tadashi

    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.

  7. 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.

  8. Help:Motion Chart | Open Energy Information

    Open Energy Info (EERE)

    information, visit the Google Help page for Motion Charts Step 2 - Setting up the Chart Once you have the data in the google doc, and it is displaying the ranges you'd like, its...

  9. 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.

  10. Controlling Motion at the Nanoscale: Rise of the Molecular Machines...

    Office of Scientific and Technical Information (OSTI)

    Published Article: Controlling Motion at the Nanoscale: Rise of the Molecular Machines Title: Controlling Motion at the Nanoscale: Rise of the Molecular Machines Authors: ...

  11. MHK Technologies/Blue Motion Energy marine turbine | Open Energy...

    Open Energy Info (EERE)

    Blue Motion Energy marine turbine < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Blue Motion Energy marine turbine.jpg Technology Profile...

  12. John Papanikolas: Visualizing Charge Carrier Motion in Nanowires...

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

    John Papanikolas: Visualizing Charge Carrier Motion in Nanowires Using Femtosecond Pump-Pr... Visualizing Charge Carrier Motion in Nanowires Using Femtosecond Pump-Probe Microscopy ...

  13. Engineering characterization of ground motion. Task I. Effects...

    Office of Scientific and Technical Information (OSTI)

    to be used to characterize motion at the foundation level of nuclear power plants. ... EARTHQUAKES; GROUND MOTION; NUCLEAR POWER PLANTS; SEISMIC EFFECTS; NONLINEAR PROBLEMS; ...

  14. CRYOGENIC MAGNETS

    DOE Patents [OSTI]

    Post, R.F.; Taylor, C.E.

    1963-05-21

    A cryogenic magnet coil is described for generating magnetic fields of the order of 100,000 gauss with a minimum expenditure of energy lost in resistive heating of the coil inductors and energy lost irreversibly in running the coil refrigeration plant. The cryogenic coil comprises a coil conductor for generating a magnetic field upon energization with electrical current, and refrigeration means disposed in heat conductive relation to the coil conductor for cooling to a low temperature. A substantial reduction in the power requirements for generating these magnetic fields is attained by scaling the field generating coil to large size and particular dimensions for a particular conductor, and operating the coil at a particular optimum temperature commensurate with minimum overall power requirements. (AEC)

  15. 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.

  16. 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.

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

    DOE Patents [OSTI]

    Casada, D.A.; Haynes, H.D.

    1993-08-17

    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.

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

    DOE Patents [OSTI]

    Casada, Donald A.; Haynes, Howard D.

    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.

  19. Cool Magnetic Molecules

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

    ... Underlying the magnetocaloric effect is the idea that magnetism is the result of the ... with the magnetic field, the magnetic entropy (disorder) of the system decreases; if ...

  20. Cool Magnetic Molecules

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

    enhanced magnetic refrigeration at very low temperatures. Not Your Mother's Refrigerator Magnets Some day soon, magnets could do more than clutter up the front of your...

  1. Macroscopic spin-orbit coupling in non-uniform magnetic fields

    SciTech Connect (OSTI)

    Tabat, N.; Edelman, H. S.; Song, D.; Vogt, T.

    2015-03-02

    Translational dynamics of aggregated magnetic nano-particles placed in a rotating external magnetic field is described. It is observed and explained that aggregates that spin within a radially decreasing field strength must execute an orbital motion of their center of mass in a sense that counters their spin rotation. This orbital motion is tightly coupled to the spin dynamics of the aggregates. An analytical model for the canonical variables describing the orbital motion is derived and shown to be in good agreement with the measured values.

  2. The feasibility of head motion tracking in helical CT: A step toward motion correction

    SciTech Connect (OSTI)

    Kim, Jung-Ha; Nuyts, Johan; Kuncic, Zdenka; Fulton, Roger

    2013-04-15

    Purpose: To establish a practical and accurate motion tracking method for the development of rigid motion correction methods in helical x-ray computed tomography (CT). Methods: A commercially available optical motion tracking system provided 6 degrees of freedom pose measurements at 60 Hz. A 4 Multiplication-Sign 4 calibration matrix was determined to convert raw pose data acquired in tracker coordinates to a fixed CT coordinate system with origin at the isocenter of the scanner. Two calibration methods, absolute orientation (AO), and a new method based on image registration (IR), were compared by means of landmark analysis and correlation coefficient in phantom images coregistered using the derived motion transformations. Results: Transformations calculated using the IR-derived calibration matrix were found to be more accurate, with positional errors less than 0.5 mm (mean RMS), and highly correlated image voxel intensities. The AO-derived calibration matrix yielded larger mean RMS positional errors ( Asymptotically-Equal-To 1.0 mm), and poorer correlation coefficients. Conclusions: The authors have demonstrated the feasibility of accurate motion tracking for retrospective motion correction in helical CT. Their new IR-based calibration method based on image registration and function minimization was simpler to perform and delivered more accurate calibration matrices. This technique is a useful tool for future work on rigid motion correction in helical CT and potentially also other imaging modalities.

  3. 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.

  4. The motional Stark effect polarimeter in the HL-2A tokamak

    SciTech Connect (OSTI)

    Yu, D. L. Wei, Y. L.; Xia, F.; Cao, J. Y.; Chen, C. Y.; Liu, L.; Chen, W. J.; Ji, X. Q.; Liu, Y.; Yan, L. W.; Yang, Q. W.; Duan, X. R.

    2014-05-15

    A 7-channel motional Stark effect polarimeter based on four polarizers and a spectrometer has been developed in the HL-2A tokamak, which is the first time successful utilizing this kind of polarimeter on a tokamak. The accuracy of the angle can reach ±0.25° in the calibration experiments. Pilot experiments of measuring the magnetic pitch angle have been successfully carried out in the weak motional Stark effect plasma discharge with toroidal magnetic field of ∼1.3 T and beam energy of ∼25 keV/amu. The pitch angles of magnetic field are obtained for 7 spatial points covering 24 cm along major radius with time resolution of 40 ms; the profiles of safety factor are obtained by combining with the Equilibrium and Reconstruction Fitting Code. The core value of safety factor (q) is less than 1 during the sawtooth oscillation and the position of q = 1 surface is well consistent with the results measured by soft X-ray array.

  5. motion-of-large-riprap-rocks

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

    Development of a Computational Approach to Detect Instability and Incipient Motion of Large Riprap Rocks" Presentation at the Transportation Research Board Annual Meeting Washington DC, January 14, 2014 Paper number 14-3035 Cezary Bojanowski Transportation Research and Analysis Computing Center (TRACC), Energy Systems Division Argonne National Laboratory Steven Lottes Transportation Research and Analysis Computing Center (TRACC), Energy Systems Division Argonne National Laboratory Abstract

  6. 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.

  7. 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.

  8. 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 ...

  9. Forming rotated SAR images by real-time motion compensation....

    Office of Scientific and Technical Information (OSTI)

    Forming rotated SAR images by real-time motion compensation. Citation Details In-Document Search Title: Forming rotated SAR images by real-time motion compensation. Proper waveform...

  10. Motion to Intervene and Initial Comments of PJM Interconnection...

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

    Initial Comments of PJM Interconnection, L.L.C. Motion to Intervene and Initial Comments of PJM Interconnection, L.L.C. Motion to Intervene and Initial Comments of PJM ...

  11. Video: Collective cell motion - rotation | Argonne National Laboratory

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

    Video: Collective cell motion - rotation Share Topic Environment Biology Computational biology Programs Materials science Materials simulation & theory Mathematics, computing, & ...

  12. Spectral line broadening in magnetized black holes

    SciTech Connect (OSTI)

    Frolov, Valeri P.; Shoom, Andrey A.; Tzounis, Christos E-mail: ashoom@ualberta.ca

    2014-07-01

    We consider weakly magnetized non-rotating black holes. In the presence of a regular magnetic field the motion of charged particles in the vicinity of a black hole is modified. As a result, the position of the innermost stable circular orbit (ISCO) becomes closer to the horizon. When the Lorentz force is repulsive (directed from the black hole) the ISCO radius can reach the gravitational radius. In the process of accretion charged particles (ions) of the accreting matter can be accumulated near their ISCO, while neutral particles fall down to the black hole after they reach 6M radius. The sharp spectral line Fe α, emitted by iron ions at such orbits, is broadened when the emission is registered by a distant observer. In this paper we study this broadening effect and discuss how one can extract information concerning the strength of the magnetic field from the observed spectrum.

  13. Motion to Withdraw from Yucca Mountain application | Department of Energy

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

    Motion to Withdraw from Yucca Mountain application Motion to Withdraw from Yucca Mountain application DOE's withdraws it's pending license application for a permanent geologic repository at Yucca Mountain, Nevada. PDF icon Motion to Withdraw from Yucca Mountain application More Documents & Publications Heating Ventilation and Air Conditioning Efficiency Greenpower Trap Mufflerl System CERTIFIED REALTY SPECIALIST

  14. 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.

  15. 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.

  16. Try This: Household Magnets

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

    Household Magnets Household Magnets Chances are very good that you have experimented with magnets. People have been fascinated with magnetism for thousands of years. As familiar to us as they may be, magnets still have some surprises for us. Here is a small collection of some of our favorite magnet experiments. What happens when we break a magnet in half? Radio Shack sells cheap ceramic magnets in several shapes. Get a ring shaped magnet and break it with pliers or a tap with a hammer. Try to

  17. Permanent magnet assembly

    DOE Patents [OSTI]

    Chell, Jeremy; Zimm, Carl B.

    2006-12-12

    A permanent magnet assembly is disclosed that is adapted to provide a magnetic field across an arc-shaped gap. Such a permanent magnet assembly can be used, for example, to provide a time-varying magnetic field to an annular region for use in a magnetic refrigerator.

  18. System and method for generating motion corrected tomographic images

    DOE Patents [OSTI]

    Gleason, Shaun S.; Goddard, Jr., James S.

    2012-05-01

    A method and related system for generating motion corrected tomographic images includes the steps of illuminating a region of interest (ROI) to be imaged being part of an unrestrained live subject and having at least three spaced apart optical markers thereon. Simultaneous images are acquired from a first and a second camera of the markers from different angles. Motion data comprising 3D position and orientation of the markers relative to an initial reference position is then calculated. Motion corrected tomographic data obtained from the ROI using the motion data is then obtained, where motion corrected tomographic images obtained therefrom.

  19. GRANULAR-SCALE MAGNETIC FLUX CANCELLATIONS IN THE PHOTOSPHERE

    SciTech Connect (OSTI)

    Kubo, M.; Low, B. C.; Lites, B. W.

    2010-04-01

    We investigate the evolution of five granular-scale magnetic flux cancellations just outside the moat region of a sunspot by using accurate spectropolarimetric measurements and G-band images with the Solar Optical Telescope (SOT) aboard Hinode. The opposite-polarity magnetic elements approach a junction of the intergranular lanes and then collide with each other there. The intergranular junction has strong redshifts, darker intensities than the regular intergranular lanes, and surface converging flows. This clearly confirms that the converging and downward convective motions are essential for the approaching process of the opposite-polarity magnetic elements. However, the motion of the approaching magnetic elements does not always match with their surrounding surface flow patterns in our observations. This suggests that, in addition to the surface flows, subsurface downward convective motions and subsurface magnetic connectivities are important for understanding the approach and collision of the opposite-polarity elements observed in the photosphere. We find that the horizontal magnetic field appears between the canceling opposite-polarity elements in only one event. The horizontal fields are observed along the intergranular lanes with Doppler redshifts. This cancellation is most probably a result of the submergence (retraction) of low-lying photospheric magnetic flux. In the other four events, the horizontal field is not observed between the opposite-polarity elements at any time when they approach and cancel each other. These approaching magnetic elements are more concentrated rather than gradually diffused, and they have nearly vertical fields even while they are in contact each other. We thus infer that the actual flux cancellations are highly time-dependent events at scales less than a pixel of Hinode SOT (about 200 km) near the solar surface.

  20. 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.

  1. Error Reduction in Weigh-In-Motion

    Energy Science and Technology Software Center (OSTI)

    2007-09-21

    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 bounding 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 lessmore » effort (elimination of redundant weighing)« less

  2. 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).

  3. Diffusional Motion of Redox Centers in Carbonate Electrolytes

    SciTech Connect (OSTI)

    Han, Kee Sung; Rajput, Nav Nidhi; Wei, Xiaoliang; Wang, Wei; Hu, Jian Z.; Persson, Kristin A.; Mueller, Karl T.

    2014-09-14

    Ferrocene (Fc) and N-(ferrocenylmethyl)-N,N-dimethyl-N-ethylammonium bistrifluoromethyl-sulfonimide (Fc1N112-TFSI) were dissolved in carbonate solvents and self diffusion coefficents (D) of solutes and solvents were measured by 1H and 19F pulsed field gradient (PFG) nuclear magnetic resonance (NMR) spectroscopy. The organic solvents were propylene carbonate (PC), ethyl methyl carbonate (EMC) and a ternary mixture that also includes ethylene carbonate (EC). Results from NMR studies over the temperature range of 0-50 C and for various concentrations (0.25 - 1.7 M) of Fc1N112-TFSI are compared to values of D simulated with classical molecular dynamics (MD). The measured self-diffusion coefficients gradually decreased as the Fc1N112-TFSI concentration increased in all solvents. Since the peaks for the two ions (Fc1N212 and TFSI) are separated in one-dimensional NMR spectra, separate diffusion coefficients could be measured and DTFSI is larger than DFc1N112 in all samples measured. The EC, PC and EMC have the same D in the neat solvent mixture and when Fc is dissolved in EC/PC/EMC at a concentration of 0.2 M, probably due to the interactions between common carbonyl structures within EC, PC and EMC. A difference in D (DPC < DEC < DEMC), and both a higher Ea for translational motion and higher effective viscosity for PC in the mixture containing Fc1N112-TFSI reflect the interaction between PC and Fc1N112+, which is a relatively stronger interaction than that between Fc1N112+ and other solvent species. In the EC/PC/EMC solution that is saturated with Fc1N112-TFSI, we find that DPC = DEC = DEMC and Fc1N112+ and all components of the EC/PC/EMC solution have the same Ea for translational motion, while the ratio DEC/PC/EMC/DFc1N112+ is approximately 3. These results reflect the lack of available free volume for independent diffusion in the saturated solution. The Fc1N112+ transference numbers lie around 0.4 and increases slightly as the temperature is increased in the PC and EMC solvents. The trends observed for D from simulations are in good agreement with experimental results and provide molecular level understanding of the solvation structure of Fc1N112-TFSI dissolved in EC/PC/EMC.

  4. Diffusional motion of redox centers in carbonate electrolytes

    SciTech Connect (OSTI)

    Han, Kee Sung; Rajput, Nav Nidhi; Persson, Kristin A.; Wei, Xiaoliang; Wang, Wei; Hu, Jian Zhi; Mueller, Karl T.

    2014-09-14

    Ferrocene (Fc) and N-(ferrocenylmethyl)-N,N-dimethyl-N-ethylammonium bistrifluoromethyl-sulfonimide (Fc1N112-TFSI) were dissolved in carbonate solvents and self-diffusion coefficients (D) of solutes and solvents were measured by {sup 1}H and {sup 19}F pulsed field gradient nuclear magnetic resonance (NMR) spectroscopy. The organic solvents were propylene carbonate (PC), ethyl methyl carbonate (EMC), and a ternary mixture that also includes ethylene carbonate (EC). Results from NMR studies over the temperature range of 050 C and for various concentrations (0.251.7 M) of Fc1N112-TFSI are compared to values of D simulated with classical molecular dynamics (MD). The measured self-diffusion coefficients gradually decreased as the Fc1N112-TFSI concentration increased in all solvents. Since TFSI{sup ?} has fluoromethyl groups (CF{sub 3}), D{sub TFSI} could be measured separately and the values found are larger than those for D{sub Fc1N112} in all samples measured. The EC, PC, and EMC have the same D in the neat solvent mixture and when Fc is dissolved in EC/PC/EMC at a concentration of 0.2 M, probably due to the interactions between common carbonyl structures within EC, PC, and EMC. A difference in D (D{sub PC} < D{sub EC} < D{sub EMC}), and both a higher E{sub a} for translational motion and higher effective viscosity for PC in the mixture containing Fc1N112-TFSI reflect the interaction between PC and Fc1N112{sup +}, which is a relatively stronger interaction than that between Fc1N112{sup +} and other solvent species. In the EC/PC/EMC solution that is saturated with Fc1N112-TFSI, we find that D{sub PC} = D{sub EC} = D{sub EMC} and Fc1N112{sup +} and all components of the EC/PC/EMC solution have the same E{sub a} for translational motion, while the ratio D{sub EC/PC/EMC}/D{sub Fc1N112} is approximately 3. These results reflect the lack of available free volume for independent diffusion in the saturated solution. The Fc1N112{sup +} transference numbers lie around 0.4 and increase slightly as the temperature is increased in the PC and EMC solvents. The trends observed for D from simulations are in good agreement with experimental results and provide molecular level understanding of the solvation structure of Fc1N112-TFSI dissolved in EC/PC/EMC.

  5. 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.

  6. 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.

  7. Telescoping magnetic ball bar test gage

    DOE Patents [OSTI]

    Bryan, J.B.

    1984-03-13

    A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengageable servo drives which cannot be clutched out is disclosed. 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. 3 figs.

  8. Telescoping magnetic ball bar test gage

    DOE Patents [OSTI]

    Bryan, James B.

    1984-01-01

    A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengageable servo drives which cannot be clutched out. Two gage balls (10, 12) 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 (14) and a rigid member (16, 18, 20, 22, 24). One gage ball (10) is secured by a magnetic socket knuckle assembly (34) which fixes its center with respect to the machine being tested. The other gage ball (12) is secured by another magnetic socket knuckle assembly (38) which is engaged or held by the machine in such manner that the center of that ball (12) is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball (10). As the moving ball (12) executes its trajectory, changes in the radial distance between the centers of the two balls (10, 12) caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly (50, 52, 54, 56, 58, 60) actuated by the parallel reed flexure unit (14). Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball (10) locations, thereby determining the accuracy of the machine.

  9. Magnetization of neutron matter

    SciTech Connect (OSTI)

    Bigdeli, M.

    2011-09-21

    In this paper, we compute magnetization of neutron matter at strong magnetic field using the lowest order constrained variational (LOCV) technique.

  10. TWISTED MAGNETIC FLUX TUBES IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Zaqarashvili, Teimuraz V.; Vörös, Zoltán; Narita, Yasuhito; Bruno, Roberto

    2014-03-01

    Magnetic flux tubes in the solar wind can be twisted as they are transported from the solar surface, where the tubes are twisted due to photospheric motions. It is suggested that the twisted magnetic tubes can be detected as the variation of total (thermal+magnetic) pressure during their passage through the observing satellite. We show that the total pressure of several observed twisted tubes resembles the theoretically expected profile. The twist of the isolated magnetic tube may explain the observed abrupt changes of magnetic field direction at tube walls. We have also found some evidence that the flux tube walls can be associated with local heating of the plasma and elevated proton and electron temperatures. For the tubes aligned with the Parker spiral, the twist angle can be estimated from the change of magnetic field direction. Stability analysis of twisted tubes shows that the critical twist angle of the tube with a homogeneous twist is 70°, but the angle can further decrease due to the motion of the tube with respect to the solar wind stream. The tubes with a stronger twist are unstable to the kink instability, therefore they probably cannot reach 1 AU.

  11. MAGNETIC DENSITOMETER

    DOE Patents [OSTI]

    McCann, J.A.; Jones, R.H.

    1961-08-15

    A magnetic densitometer for locating defects and metallic inclusions in materials is described. The apparatus consists of two primary coils connected in series opposition and adapted te be placed in inductive relation to the material under test, a source of constant frequency alternating current coupled across the primary coil combination, a pick-up coil disposed in symmetrical inductive relationship with said primary coils, a phase-shifter coupled to the output of the energizing source. The output of the phase-shifter is coupled in series with the pick-up coil. An amplifier is provided selective to the third harmonic of the energizing source frequency. The series combination of the pick-up coil and the phase-shifter output are connected across the input of the amplifier, and an amplitude comparitor is coupled to the output of the amplifier and the energizing source for comparing the instantaneous amplitude of the amplifier output and the instantaneous output of the energizing source and producing an output proportional to the difference in amplitude. A recorder is coupled to the output of the amplitude comparison means to give an indication of the amplitude difference, thereby providing a permanent presentation of the character of the changes in characteristics exhibited by the material under test. (AEC)

  12. Magnetic vortex dynamics on a picosecond timescale in a hexagonal permalloy pattern

    SciTech Connect (OSTI)

    Shim, J.-H.; Kim, D.-H.; Mesler, B.; Moon, J.-H.; Lee, K.-J.; Anderson, E. H.; Fischer, P.

    2009-12-02

    We have observed a motion of magnetic vortex core in a hexagonal Permalloy pattern by means of Soft X-ray microscopy. Pump-probe stroboscopic observation on a picosecond timescale has been carried out after exciting a ground state vortex structure by an external field pulse of 1 ns duration. Vortex core is excited off from the center position of the hexagonal pattern but the analysis of the core trajectory reveals that the motion is nongyrotropic.

  13. Target motion tracking with a scanned particle beam

    SciTech Connect (OSTI)

    Bert, Christoph; Saito, Nami; Schmidt, Alexander; Chaudhri, Naved; Schardt, Dieter; Rietzel, Eike

    2007-12-15

    Treatment of moving targets with scanned particle beams results in local over- and under-dosage due to interplay of beam and target motion. To mitigate the impact of respiratory motion, a motion tracking system has been developed and integrated in the therapy control system at Gesellschaft fuer Schwerionenforschung. The system adapts pencil beam positions as well as the beam energy according to target motion to irradiate the planned position. Motion compensation performance of the tracking system was assessed by measurements with radiographic films and a 3D array of 24 ionization chambers. Measurements were performed for stationary detectors and moving detectors using the tracking system. Film measurements showed comparable homogeneity inside the target area. Relative differences of 3D dose distributions within the target volume were 1{+-}2% with a maximum of 4%. Dose gradients and dose to surrounding areas were in good agreement. The motion tracking system successfully preserved dose distributions delivered to moving targets and maintained target conformity.

  14. 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.

  15. Solid state engine with alternating motion

    DOE Patents [OSTI]

    Golestaneh, Ahmad A. (Bolingbrook, IL)

    1982-01-01

    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.

  16. Department of Energy Files Motion to Withdraw Yucca Mountain License

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

    Application | 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 - 12:00am Addthis WASHINGTON, D.C. - The U.S. Department of Energy today filed a motion with the Nuclear Regulatory Commission to withdraw the license application for a high-level nuclear waste repository at Yucca Mountain with prejudice. "President Obama is fully committed to ensuring that the

  17. 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.

  18. Magnetic Membrane System

    DOE Patents [OSTI]

    McElfresh, Michael W.; (Livermore, CA); Lucas, Matthew S.; (Pasadena, CA)

    2004-12-30

    The present invention provides a membrane with magnetic particles. In one embodiment the membrane is created by mixing particles in a non-magnetic base. The membrane may act as an actuator, a sensor, a pump, a valve, or other device. A magnet is operatively connected to the membrane. The magnet acts on and changes the shape of the membrane.

  19. Joint Motion to Intervene of Northern States Power Company (Minnesota...

    Energy Savers [EERE]

    States Power Company (Minnesota) et al. on the Proposed Open Access Requirements Joint Motion to Intervene of Northern States Power Company (Minnesota) et al. on the Proposed ...

  20. ARM - Evaluation Product - MPL Corrected for Ship Motion (MPLPOLFSSHIP...

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

    is provided as an evaluation product for the MAGIC and ACAPEX campaigns. The signal return values and the rangebinwidth are corrected to account for the motion (pitch,...

  1. Motion of Robert G. Burnley, Director the Commonwealth of Virginia...

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

    of Robert G. Burnley, Director the Commonwealth of Virginia Department of Environmental ... Motion of Robert G. Burnley, Director the Commonwealth of Virginia Department of ...

  2. Motion for Leave to File Consolidated Answer and Consolidated...

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

    G. Burnley, Director of the Commenwealth of Virginia Department of Environmental Quality Motion for Leave to File Consolidated Answer and Consolidated Answer of Robert G. ...

  3. Widget:Motion Chart Visualizations | Open Energy Information

    Open Energy Info (EERE)

    References usenergyconsumption: SED data usconsumption2010: SED data worldenergysupply: OECD data Retrieved from "http:en.openei.orgwindex.php?titleWidget:MotionChartVisuali...

  4. 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.

  5. Green Growth in Motion: Sharing Korea's Experience | Open Energy...

    Open Energy Info (EERE)

    lt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":"" Hide Map Language: English Green Growth in Motion: Sharing Korea's Experience Screenshot References:...

  6. Seismic Ground Motion Response Using SHAKE, EERA and NERA for...

    Office of Environmental Management (EM)

    Seismic Ground Motion Response Using SHAKE, EERA and NERA for SRS Soil Profile Jay Amin - Structural Mechanics, Principal Engineer Shawn Carey, PhD, PE - Structural Mechanics, ...

  7. Simulation of Explosion Ground Motions Using a Hydrodynamic-to...

    Office of Scientific and Technical Information (OSTI)

    Simulation of Explosion Ground Motions Using a Hydrodynamic-to-Elastic Coupling Approach in Three-Dimensions Citation Details In-Document Search Title: Simulation of Explosion ...

  8. NMR Investigations of Network Formation and Motional Dynamics...

    Office of Scientific and Technical Information (OSTI)

    NMR Investigations of Network Formation and Motional Dynamics in Well-Defined Model Poly(dimethylsiloxane) Elastomers Citation Details In-Document Search Title: NMR Investigations ...

  9. Design and Control of a Ship Motion Simulation Platform from...

    Office of Scientific and Technical Information (OSTI)

    Journal 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 ...

  10. 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 5-8minute repetition times and ?100kms{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 ?2.6minutes, but the sky-plane speeds and wavelengths depend on the heights of the waves above the sunspot. In the chromosphere, the waves decelerate from 35-45kms{sup 1} in the umbra to 7-8kms{sup 1} toward the outer edge of the penumbra, but in the corona, the waves accelerate to ?60-100kms{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.

  11. 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.

  12. Recycling Magnets | Jefferson Lab

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

    Recycling Magnets Recycling Magnets July 15, 2013 The cost of a nuclear or particle physics experiment can be enormous, several hundred million dollars for the Large Hadron Collider Experiments, ATLAS and CMS at CERN, several tens of millions of dollars for an experiment like our GlueX experiment in Hall D, being built as part of our upgrade project. Among the expensive components of many experiments is a large magnet or sometimes more than one magnet. Sometimes the magnets have interesting

  13. 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.

  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. 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.

  16. Magnetic switch coupling to synchronize magnetic modulators

    DOE Patents [OSTI]

    Reed, Kim W.; Kiekel, Paul

    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.

  17. 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.

  18. Dynamic MRI of Grid-Tagged Hyperpolarized Helium-3 for the Assessment of Lung Motion During Breathing

    SciTech Connect (OSTI)

    Cai Jing; Sheng Ke; Benedict, Stanley H.; Read, Paul W.; Larner, James M.; Mugler, John P.; Lange, Eduard E. de; Cates, Gordon D.; Miller, G. Wilson

    2009-09-01

    Purpose: To develop a dynamic magnetic resonance imaging (MRI) tagging technique using hyperpolarized helium-3 (HP He-3) to track lung motion. Methods and Materials: An accelerated non-Cartesian k-space trajectory was used to gain acquisition speed, at the cost of introducing image artifacts, providing a viable strategy for obtaining whole-lung coverage with adequate temporal resolution. Multiple-slice two-dimensional dynamic images of the lung were obtained in three healthy subjects after inhaling He-3 gas polarized to 35%-40%. Displacement, strain, and ventilation maps were computed from the observed motion of the grid peaks. Results: Both temporal and spatial variations of pulmonary mechanics were observed in normal subjects, including shear motion between different lobes of the same lung. Conclusion: These initial results suggest that dynamic imaging of grid-tagged hyperpolarized magnetization may potentially be a powerful tool for observing and quantifying pulmonary biomechanics on a regional basis and for assessing, validating, and improving lung deformable image registration algorithms.

  19. 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.

  20. Method and apparatus for planning motions of robot manipulators

    DOE Patents [OSTI]

    Chen, Pang C.; Hwang, Yong K.

    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.

  1. Exact physical model for magnets in storage rings

    SciTech Connect (OSTI)

    Maletic, D.; Ruggiero, A.G.

    1992-12-31

    In this report we try to make estimates of both kinematic and field effects on the stability of a particle motion, by employing a truly Maxwellian representation of the magnetic field in exact equations of motion. For this purpose we adopt a simple FODO cell model, which repeats periodically to infinity. This model includes only quadrupoles and drifts, leaving out the bending magnets to avoid the problem of the trajectory curvature. We think this model is a physically consistent approximation of a storage ring. We derive several models with different levels of approximation and compare them by evaluating the importance of these effects. The relevance to long-term stability is being investigated in the meantime by comparing the different models with extensive computer simulations. The results will be shown in a subsequent report.

  2. GAIA: A WINDOW TO LARGE-SCALE MOTIONS

    SciTech Connect (OSTI)

    Nusser, Adi; Branchini, Enzo; Davis, Marc E-mail: branchin@fis.uniroma3.it

    2012-08-10

    Using redshifts as a proxy for galaxy distances, estimates of the two-dimensional (2D) transverse peculiar velocities of distant galaxies could be obtained from future measurements of proper motions. We provide the mathematical framework for analyzing 2D transverse motions and show that they offer several advantages over traditional probes of large-scale motions. They are completely independent of any intrinsic relations between galaxy properties; hence, they are essentially free of selection biases. They are free from homogeneous and inhomogeneous Malmquist biases that typically plague distance indicator catalogs. They provide additional information to traditional probes that yield line-of-sight peculiar velocities only. Further, because of their 2D nature, fundamental questions regarding vorticity of large-scale flows can be addressed. Gaia, for example, is expected to provide proper motions of at least bright galaxies with high central surface brightness, making proper motions a likely contender for traditional probes based on current and future distance indicator measurements.

  3. Tamper resistant magnetic stripes

    DOE Patents [OSTI]

    Naylor, Richard Brian; Sharp, Donald J.

    1999-01-01

    This invention relates to a magnetic stripe comprising a medium in which magnetized particles are suspended and in which the encoded information is recorded by actual physical rotation or alignment of the previously magnetized particles within the flux reversals of the stripe which are 180.degree. opposed in their magnetic polarity. The magnetized particles are suspended in a medium which is solid, or physically rigid, at ambient temperatures but which at moderately elevated temperatures, such as 40.degree. C., is thinable to a viscosity permissive of rotation of the particles therein under applications of moderate external magnetic field strengths within acceptable time limits.

  4. 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 listWISEA J154045.67510139.3is 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.

  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. Lensless Imaging of Magnetic Nanostructures

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

    Lensless Imaging of Magnetic Nanostructures Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging...

  7. Lensless Imaging of Magnetic Nanostructures

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

    Imaging of Magnetic Nanostructures Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in...

  8. Active magnetic regenerator

    DOE Patents [OSTI]

    Barclay, John A.; Steyert, William A.

    1982-01-01

    The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.

  9. 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.

  10. Cool Magnetic Molecules

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

    Cool Magnetic Molecules Cool Magnetic Molecules Print Wednesday, 25 May 2011 00:00 Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost

  11. 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.

  12. 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.

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

    DOE Patents [OSTI]

    Hilal, Sadek K.; Sampson, William B.; Leonard, Edward F.

    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.

  14. Scaling laws in magnetized plasma turbulence

    SciTech Connect (OSTI)

    Boldyrev, Stanislav

    2015-06-28

    Interactions of plasma motion with magnetic fields occur in nature and in the laboratory in an impressively broad range of scales, from megaparsecs in astrophysical systems to centimeters in fusion devices. The fact that such an enormous array of phenomena can be effectively studied lies in the existence of fundamental scaling laws in plasma turbulence, which allow one to scale the results of analytic and numerical modeling to the sized of galaxies, velocities of supernovae explosions, or magnetic fields in fusion devices. Magnetohydrodynamics (MHD) provides the simplest framework for describing magnetic plasma turbulence. Recently, a number of new features of MHD turbulence have been discovered and an impressive array of thought-provoking phenomenological theories have been put forward. However, these theories have conflicting predictions, and the currently available numerical simulations are not able to resolve the contradictions. MHD turbulence exhibits a variety of regimes unusual in regular hydrodynamic turbulence. Depending on the strength of the guide magnetic field it can be dominated by weakly interacting Alfv\\'en waves or strongly interacting wave packets. At small scales such turbulence is locally anisotropic and imbalanced (cross-helical). In a stark contrast with hydrodynamic turbulence, which tends to ``forget'' global constrains and become uniform and isotropic at small scales, MHD turbulence becomes progressively more anisotropic and unbalanced at small scales. Magnetic field plays a fundamental role in turbulent dynamics. Even when such a field is not imposed by external sources, it is self-consistently generated by the magnetic dynamo action. This project aims at a comprehensive study of universal regimes of magnetic plasma turbulence, combining the modern analytic approaches with the state of the art numerical simulations. The proposed study focuses on the three topics: weak MHD turbulence, which is relevant for laboratory devices, the solar wind, solar corona heating, and planetary magnetospheres; strong MHD turbulence, which is relevant for fusion devices, star formation, cosmic rays acceleration, scattering and trapping in galaxies, as well as many aspects of dynamics, distribution and composition of space plasmas, and the process of magnetic dynamo action, which explains the generation and the structure of magnetic fields in turbulent plasmas. The planned work will aim at developing new analytic approaches, conducting new numerical simulations with currently unmatched resolution, and training students in the methods of the modern theory of plasma turbulence. The work will be performed at the University of Wisconsin--Madison.

  15. Proton spin tracking with symplectic integration of orbit motion

    SciTech Connect (OSTI)

    Luo, Y.; Dutheil, Y.; Huang, H.; Meot, F.; Ranjbar, V.

    2015-05-03

    Symplectic integration had been adopted for orbital motion tracking in code SimTrack. SimTrack has been extensively used for dynamic aperture calculation with beam-beam interaction for the Relativistic Heavy Ion Collider (RHIC). Recently proton spin tracking has been implemented on top of symplectic orbital motion in this code. In this article, we will explain the implementation of spin motion based on Thomas-BMT equation, and the benchmarking with other spin tracking codes currently used for RHIC. Examples to calculate spin closed orbit and spin tunes are presented too.

  16. Monitoring internal organ motion with continuous wave radar in CT

    SciTech Connect (OSTI)

    Pfanner, Florian; Maier, Joscha; Allmendinger, Thomas; Flohr, Thomas; Kachelrieß, Marc

    2013-09-15

    Purpose: To avoid motion artifacts in medical imaging or to minimize the exposure of healthy tissues in radiation therapy, medical devices are often synchronized with the patient's respiratory motion. Today's respiratory motion monitors require additional effort to prepare the patients, e.g., mounting a motion belt or placing an optical reflector on the patient's breast. Furthermore, they are not able to measure internal organ motion without implanting markers. An interesting alternative to assess the patient's organ motion is continuous wave radar. The aim of this work is to design, implement, and evaluate such a radar system focusing on application in CT.Methods: The authors designed a radar system operating in the 860 MHz band to monitor the patient motion. In the intended application of the radar system, the antennas are located close to the patient's body inside the table of a CT system. One receive and four transmitting antennas are used to avoid the requirement of exact patient positioning. The radar waves propagate into the patient's body and are reflected at tissue boundaries, for example at the borderline between muscle and adipose tissue, or at the boundaries of organs. At present, the authors focus on the detection of respiratory motion. The radar system consists of the hardware mentioned above as well as of dedicated signal processing software to extract the desired information from the radar signal. The system was evaluated using simulations and measurements. To simulate the radar system, a simulation model based on radar and wave field equations was designed and 4D respiratory-gated CT data sets were used as input. The simulated radar signals and the measured data were processed in the same way. The radar system hardware and the signal processing algorithms were tested with data from ten volunteers. As a reference, the respiratory motion signal was recorded using a breast belt simultaneously with the radar measurements.Results: Concerning the measurements of the test persons, there is a very good correlation (ρ= 0.917) between the respiratory motion phases received by the radar system and the external motion monitor. Our concept of using an array of transmitting antennas turned out to be widely insensitive to the positioning of the test persons. A time shift between the respiratory motion curves recorded with the radar system and the motion curves from the external respiratory monitor was observed which indicates a slight difference between internal organ motion and motion detected by the external respiratory monitor. The simulations were in good accordance with the measurements.Conclusions: A continuous wave radar operating in the near field of the antennas can be used to determine the respiratory motion of humans accurately. In contrast to trigger systems used today, the radar system is able to measure motion inside the body. If such a monitor was routinely available in clinical CT, it would be possible optimizing the scan start with respect to the respiratory state of the patient. Breathing commands would potentially widely be avoided, and as far as uncooperative patients or children are concerned, less sedation might be necessary. Further applications of the radar system could be in radiation therapy or interventional imaging for instance.

  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. Motion to Intervene Out of Time and Comments of FirstEnergy Service...

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

    Motion to Intervene Out of Time and Comments of FirstEnergy Service Company PP-230-3 Motion to Intervene Out of Time and Comments of FirstEnergy Service Company PDF icon Motion to ...

  19. Motion to Intervene and Comments of Public Utility District No...

    Office of Environmental Management (EM)

    Comments of Public Utility District No. 1 (Pend Oreille County, Washington) on PP 99-1 Notice of Intent to Amend Presidential Permit Motion to Intervene and Comments of Public ...

  20. DOE Defends Its Motion to Withdraw Yucca Mountain Application

    Broader source: Energy.gov [DOE]

    Today, the United States Department of Energy filed with the NRC's Atomic Safety and Licensing Board a reply brief making clear that its motion to withdraw the pending application to license the...

  1. Cataclysmic variables in the SUPERBLINK proper motion survey

    SciTech Connect (OSTI)

    Skinner, Julie N.; Thorstensen, John R.; Lpine, Sbastien

    2014-12-01

    We have discovered a new high proper motion cataclysmic variable (CV) in the SUPERBLINK proper motion survey, which is sensitive to stars with proper motions greater than 40 mas yr{sup ?1}. This CV was selected for follow-up observations as part of a larger search for CVs selected based on proper motions and their near-UV?V and V?K{sub s} colors. We present spectroscopic observations from the 2.4 m Hiltner Telescope at MDM Observatory. The new CV's orbital period is near 96 minutes, its spectrum shows the double-peaked Balmer emission lines characteristic of quiescent dwarf novae, and its V magnitude is near 18.2. Additionally, we present a full list of known CVs in the SUPERBLINK catalog.

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

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

    March 3, 2010 - 12:00am Addthis WASHINGTON, D.C. - The U.S. Department of Energy today filed a motion with the Nuclear Regulatory Commission to withdraw the license application for ...

  3. ARM - Evaluation Product - Vertical Air Motion during Large-Scale...

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

    ProductsVertical Air Motion during Large-Scale Stratiform Rain ARM Data Discovery Browse ... Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Vertical Air ...

  4. 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.

  5. NMR Investigations of Network Formation and Motional Dynamics in

    Office of Scientific and Technical Information (OSTI)

    Well-Defined Model Poly(dimethylsiloxane) Elastomers (Journal Article) | SciTech Connect NMR Investigations of Network Formation and Motional Dynamics in Well-Defined Model Poly(dimethylsiloxane) Elastomers Citation Details In-Document Search Title: NMR Investigations of Network Formation and Motional Dynamics in Well-Defined Model Poly(dimethylsiloxane) Elastomers Authors: Lewicki, J P ; Harley, S J ; Bell, C ; Finnie, J A ; Ashmore, M ; Maxwell, R S Publication Date: 2013-05-30 OSTI

  6. The interplay between regular and chaotic motion in nuclei

    SciTech Connect (OSTI)

    Rotter, I.

    1987-04-01

    The regular motion of nucleons in the low-lying nuclear states and the chaotic motion in the compound nuclei are shown to arise from the interplay of conservative and dissipative forces in the open quantum mechanical nuclear system. The regularity at low level density is caused by self-organization in a conservative field of force. At high level density, chaoticity appears since information on the environment is transferred into the system by means of dissipative forces.

  7. John Papanikolas: Visualizing Charge Carrier Motion in Nanowires Using

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

    Femtosecond Pump-Probe Microscopy | Center for Energy Efficient Materials John Papanikolas: Visualizing Charge Carrier Motion in Nanowires Using Femtosecond Pump-Probe Microscopy Apr 17, 2014 | 4:00 PM - 5:00 PM John Papanikolas Professor of Chemistry & Deputy Director, EFRC on Solar Fuels University of North Carolina, Chapel Hill Visualizing Charge Carrier Motion in Nanowires Using Femtosecond Pump-Probe Microscopy April 17, 2014 | 4:00pm | ESB 1001 Faculty host: Dan Morse

  8. Continuous motion scan ptychography: characterization for increased speed

    Office of Scientific and Technical Information (OSTI)

    in coherent x-ray imaging (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Continuous motion scan ptychography: characterization for increased speed in coherent x-ray imaging Citation Details In-Document Search Title: Continuous motion scan ptychography: characterization for increased speed in coherent x-ray imaging Authors: Deng, Junjing ; Nashed, Youssef S. G. ; Chen, Si ; Phillips, Nicholas W. ; Peterka, Tom ; Ross, Rob ; Vogt, Stefan ; Jacobsen, Chris ;

  9. Continuous motion scan ptychography: characterization for increased speed

    Office of Scientific and Technical Information (OSTI)

    in coherent x-ray imaging (Journal Article) | DOE PAGES Continuous motion scan ptychography: characterization for increased speed in coherent x-ray imaging « Prev Next » Title: Continuous motion scan ptychography: characterization for increased speed in coherent x-ray imaging Authors: Deng, Junjing ; Nashed, Youssef S. G. ; Chen, Si ; Phillips, Nicholas W. ; Peterka, Tom ; Ross, Rob ; Vogt, Stefan ; Jacobsen, Chris ; Vine, David J. Publication Date: 2015-02-23 OSTI Identifier: 1222333

  10. Uniaxial stress-driven coupled grain boundary motion in hexagonal

    Office of Scientific and Technical Information (OSTI)

    close-packed metals: A molecular dynamics study (Journal Article) | SciTech Connect Uniaxial stress-driven coupled grain boundary motion in hexagonal close-packed metals: A molecular dynamics study Citation Details In-Document Search This content will become publicly available on January 1, 2017 Title: Uniaxial stress-driven coupled grain boundary motion in hexagonal close-packed metals: A molecular dynamics study Authors: Zong, Hongxiang ; Ding, Xiangdong ; Lookman, Turab ; Li, Ju ; Sun,

  11. Variable Charge Motion for 2007-2010 Heavy Duty Diesel Engines...

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

    Charge Motion for 2007-2010 Heavy Duty Diesel Engines Variable Charge Motion for 2007-2010 Heavy Duty Diesel Engines 2003 DEER Conference Presentation: AVL Powertrain Engineering ...

  12. SISMA (Site of Italian Strong Motion Accelerograms): a Web-Database of Ground Motion Recordings for Engineering Applications

    SciTech Connect (OSTI)

    Scasserra, Giuseppe; Lanzo, Giuseppe; D'Elia, Beniamino; Stewart, Jonathan P.

    2008-07-08

    The paper describes a new website called SISMA, i.e. Site of Italian Strong Motion Accelerograms, which is an Internet portal intended to provide natural records for use in engineering applications for dynamic analyses of structural and geotechnical systems. SISMA contains 247 three-component corrected motions recorded at 101 stations from 89 earthquakes that occurred in Italy in the period 1972-2002. The database of strong motion accelerograms was developed in the framework of a joint project between Sapienza University of Rome and University of California at Los Angeles (USA) and is described elsewhere. Acceleration histories and pseudo-acceleration response spectra (5% damping) are available for download from the website. Recordings can be located using simple search parameters related to seismic source and the recording station (e.g., magnitude, V{sub s30}, etc) as well as ground motion characteristics (e.g. peak ground acceleration, peak ground velocity, peak ground displacement, Arias intensity, etc.)

  13. Respiratory motion effects on whole breast helical tomotherapy

    SciTech Connect (OSTI)

    Moeckly, Steven R.; Lamba, Michael; Elson, Howard R.

    2008-04-15

    The effects of intrafraction respiratory motion on nonhelical intensity-modulated radiotherapy have been well addressed in the literature, both theoretically and experimentally. However, the consequences of respiratory motion on helical tomotherapy, for patient-specific treatment plans, are less well known. Parameters specific to this treatment modality such as pitch, gantry speed, and degree of modulation may play prominent roles in radiation delivery with respect to intrafraction respiratory motion. This phantom-based study specifically addressed the effects of intrafraction respiratory motion on whole breast helical tomotherapy. A device capable of driving an acrylic phantom with reproducible, one-dimensional, anterior-posterior motion resembling a sinusoid of 4.6 mm crest-trough amplitude was developed. A plan to irradiate the corner of an acrylic phantom using parameters typical of a whole breast helical tomotherapy technique was developed using the TomoTherapy Hi-Art-II System registered . The treatment was delivered to the phantom, with Kodak EDR2 film in the axial plane, for each of the following conditions: (i) phantom at 270 deg. initial sinusoidal phase and 12 cycles/min motion, (ii) phantom at 270 deg. initial sinusoidal phase and 18 cycles/min motion, and (iii)-(v) phantom at 18 cycles/min motion with 0 deg., 90 deg., and 180 deg. initial sinusoidal phases. A measure of technique reproducibility was also performed for several irradiations with the phantom static at 270 deg. initial sinusoidal phase. Films were processed using a Kodak MIN-R mammography film processor, scanned with a Vidar NXR-16 Dosimetry Pro scanner and analyzed with RIT113 v.4.2 software. Films were compared to a reference film irradiated under the conditions of no motion and 270 deg. sinusoidal phase. For all comparisons, 5% dose difference threshold, 3% dose difference and 2 mm distance-to-agreement gamma analysis, and isodose plots were generated. The results of this study show a small area of greater than 5% decrease in dose at the phantom's anterior surface and a 1.5-3 mm posterior-medial shift of isodose lines in the penumbral and apex regions of the PTV. Frequency and phase effects are apparent within the PTV where dose varies with high spatial frequency. As the reference film was produced by delivering the treatment plan to the phantom static and in the position corresponding to maximum expiration, results are representative of extreme deviations between planned and delivered dose with respect to sinusoidal motion of clinically relevant magnitudes and frequencies.

  14. 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.

  15. The polarization trajectory of terahertz magnetic dipole radiation in (110)-oriented PrFeO{sub 3} single crystal

    SciTech Connect (OSTI)

    Song, Gaibei; Jin, Zuanming; Lin, Xian; Jiang, Junjie; Wang, Xinyan; Wu, Hailong; Ma, Guohong E-mail: sxcao@shu.edu.cn; Cao, Shixun E-mail: sxcao@shu.edu.cn

    2014-04-28

    By using the polarized terahertz (THz) time-domain spectroscopy, the macro-magnetization motion in (110)-oriented PrFeO{sub 3} single crystal was constructed. We emphasize that the trajectory of the emitted THz waveforms relies on not only the motion of macroscopic magnetization vector, but also the spin configuration in the ground state and the propagation of THz pulse. The azimuthal angle (the incident THz pulse polarization with respect to the crystal axes) enables us to control the polarization trajectories of the quasiferromagnetic and quasiantiferromagnetic mode radiations that can lead to further applications on multiple information storing and quantum processing.

  16. Nanoscale, multidimensional artificial magnet created

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

    Nanoscale, multidimensional artificial magnet created Nanoscale, multidimensional artificial magnet created Applications might range from general magnetism, such as developing sensors, to information encoding. October 26, 2015 Researchers have created a nanoscale, artificial magnet by arranging an array of magnetic nano-islands along a geometry that is not found in natural magnets. As temperature is reduced, magnetic nanoislands (in blue) reach a one-dimensional static, ordered state, while

  17. 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.

  18. Analysis of magnetic probe signals including effect of cylindrical conducting wall for field-reversed configuration experiment

    SciTech Connect (OSTI)

    Ikeyama, Taeko; Hiroi, Masanori; Nemoto, Yuuichi; Nogi, Yasuyuki

    2008-06-15

    A confinement field is disturbed by magnetohydrodynamic (MHD) motions of a field-reversed configuration (FRC) plasma in a cylindrical conductor. The effect of the conductor should be included to obtain a spatial structure of the disturbed field with a good precision. For this purpose, a toroidal current in the plasma and an eddy current on a conducting wall are replaced by magnetic dipole and image magnetic dipole moments, respectively. Typical spatial structures of the disturbed field are calculated by using the dipole moments for such MHD motions as radial shift, internal tilt, external tilt, and n=2 mode deformation. Then, analytic formulas for estimating the shift distance, tilt angle, and deformation rate of the MHD motions from magnetic probe signals are derived. It is estimated from the calculations by using the dipole moments that the analytic formulas include an approximately 40% error. Two kinds of experiment are carried out to investigate the reliability of the calculations. First, a magnetic field produced by a circular current is measured in an aluminum pipe to confirm the replacement of the eddy current with the image magnetic dipole moments. The measured fields coincide well with the calculated values including the image magnetic dipole moments. Second, magnetic probe signals measured from the FRC plasma are substituted into the analytic formulas to obtain shift distance and deformation rate. The experimental results are compared to the MHD motions measured by using a radiation from the plasma. If the error included in the analytic formulas and the difference between the magnetic and optical structures in the plasma are considered, the results of the radiation measurement support well those of the magnetic analysis.

  19. PREDICTING MERGER-INDUCED GAS MOTIONS IN ?CDM GALAXY CLUSTERS

    SciTech Connect (OSTI)

    Nagai, Daisuke; Lau, Erwin T.; Avestruz, Camille; Rudd, Douglas H.; Nelson, Kaylea

    2013-11-10

    In the hierarchical structure formation model, clusters of galaxies form through a sequence of mergers and continuous mass accretion, which generate significant random gas motions especially in their outskirts where material is actively accreting. Non-thermal pressure provided by the internal gas motions affects the thermodynamic structure of the X-ray emitting intracluster plasma and introduces biases in the physical interpretation of X-ray and Sunyaev-Zeldovich effect observations. However, we know very little about the nature of gas motions in galaxy clusters. The ASTRO-H X-ray mission, scheduled to launch in 2015, will have a calorimeter capable of measuring gas motions in galaxy clusters at the level of ?< 100 km s{sup 1}. In this work, we predict the level of merger-induced gas motions expected in the ?CDM model using hydrodynamical simulations of galaxy cluster formation. We show that the gas velocity dispersion is larger in more massive clusters, but exhibits a large scatter. We show that systems with large gas motions are morphologically disturbed, while early forming, relaxed groups show a smaller level of gas motions. By analyzing mock ASTRO-H observations of simulated clusters, we show that such observations can accurately measure the gas velocity dispersion out to the outskirts of nearby relaxed galaxy clusters. ASTRO-H analysis of merging clusters, on the other hand, requires multi-component spectral fitting and enables unique studies of substructures in galaxy clusters by measuring both the peculiar velocities and the velocity dispersion of gas within individual sub-clusters.

  20. 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.

  1. Magnetic latching solenoid

    DOE Patents [OSTI]

    Marts, Donna J.; Richardson, John G.; Albano, Richard K.; Morrison, Jr., John L.

    1995-01-01

    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. 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. Cool Magnetic Molecules

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

    Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability

  4. Cool Magnetic Molecules

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

    Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability

  5. Cool Magnetic Molecules

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

    Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability

  6. Cool Magnetic Molecules

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

    Conversely, introducing a magnetic field to certain materials will cause the material to heat up. This happens because, as the spins in such (paramagnetic) materials align with...

  7. Cool Magnetic Molecules

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

    for applications involving enhanced magnetic refrigeration at very low temperatures. ... In molecular form, "nanomagnets" might just be the key to refrigeration that uses less ...

  8. Magnetically leviated superconducting bearing

    DOE Patents [OSTI]

    Weinberger, Bernard R.; Lynds, Jr., Lahmer

    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. Cool Magnetic Molecules

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

    (Gd). While some of this research is focused on materials that would operate near room temperature, Karotsis et al. here investigate the magnetic cooling properties of...

  10. ALSNews Vol. 300

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

    0 ALSNews Vol. 300 Print Wednesday, 29 July 2009 00:00 In This Issue Towards Heavy Fermions in Europium Intermetallic Compounds Stochastic Domain-Wall Depinning in Magnetic...

  11. OBSERVATION OF MAGNETIC RECONNECTION DRIVEN BY GRANULAR SCALE ADVECTION

    SciTech Connect (OSTI)

    Zeng Zhicheng; Cao Wenda; Ji Haisheng

    2013-06-01

    We report the first evidence of magnetic reconnection driven by advection in a rapidly developing large granule using high spatial resolution observations of a small surge event (base size {approx} 4'' Multiplication-Sign 4'') with the 1.6 m aperture New Solar Telescope at the Big Bear Solar Observatory. The observations were carried out in narrowband (0.5 A) He I 10830 A and broadband (10 A) TiO 7057 A. Since He I 10830 A triplet has a very high excitation level and is optically thin, its filtergrams enable us to investigate the surge from the photosphere through the chromosphere into the lower corona. Simultaneous space data from the Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory were used in the analysis. It is shown that the surge is spatio-temporally associated with magnetic flux emergence in the rapidly developing large granule. During the development of the granule, its advecting flow ({approx}2 km s{sup -1}) squeezed the magnetic flux into an intergranular lane area, where a magnetic flux concentration was formed and the neighboring flux with opposite magnetic polarity was canceled. During the cancellation, the surge was produced as absorption in He I 10830 A filtergrams while simultaneous EUV brightening occurred at its base. The observations clearly indicate evidence of a finest-scale reconnection process driven by the granule's motion.

  12. Observation of the chiral magnetic effect in ZrTe₅

    SciTech Connect (OSTI)

    Li, Qiang; Kharzeev, Dmitri E.; Zhang, Cheng; Huang, Yuan; Pletikosic, I.; Fedorov, A. V.; Zhong, R. D.; Schneeloch, J. A; Gu, G. D.; Valla, T.

    2015-02-08

    The chiral magnetic effect is the generation of electric current induced by chirality imbalance in the presence of magnetic field. It is a macroscopic manifestation of the quantum anomaly in relativistic field theory of chiral fermions (massless spin 1/2 particles with a definite projection of spin on momentum) – a dramatic phenomenon arising from a collective motion of particles and antiparticles in the Dirac sea. The recent discovery of Dirac semimetals with chiral quasi-particles opens a fascinating possibility to study this phenomenon in condensed matter experiments. Here we report on the first observation of chiral magnetic effect through the measurement of magneto-transport in zirconium pentatelluride, ZrTe₅. Our angle-resolved photoemission spectroscopy experiments show that this material’s electronic structure is consistent with a 3D Dirac semimetal. We observe a large negative magnetoresistance when magnetic field is parallel with the current. The measured quadratic field dependence of the magnetoconductance is a clear indication of the chiral magnetic effect. The observed phenomenon stems from the effective transmutation of Dirac semimetal into a Weyl semimetal induced by the parallel electric and magnetic fields that represent a topologically nontrivial gauge field background.

  13. Observation of the chiral magnetic effect in ZrTe₅

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

    Li, Qiang; Kharzeev, Dmitri E.; Zhang, Cheng; Huang, Yuan; Pletikosic, I.; Fedorov, A. V.; Zhong, R. D.; Schneeloch, J. A.; Gu, G. D.; Valla, T.

    2015-02-08

    The chiral magnetic effect is the generation of electric current induced by chirality imbalance in the presence of magnetic field. It is a macroscopic manifestation of the quantum anomaly in relativistic field theory of chiral fermions (massless spin 1/2 particles with a definite projection of spin on momentum) – a dramatic phenomenon arising from a collective motion of particles and antiparticles in the Dirac sea. The recent discovery of Dirac semimetals with chiral quasi-particles opens a fascinating possibility to study this phenomenon in condensed matter experiments. Here we report on the first observation of chiral magnetic effect through the measurementmore » of magneto-transport in zirconium pentatelluride, ZrTe₅. Our angle-resolved photoemission spectroscopy experiments show that this material’s electronic structure is consistent with a 3D Dirac semimetal. We observe a large negative magnetoresistance when magnetic field is parallel with the current. The measured quadratic field dependence of the magnetoconductance is a clear indication of the chiral magnetic effect. Furthermore, the observed phenomenon stems from the effective transmutation of Dirac semimetal into a Weyl semimetal induced by the parallel electric and magnetic fields that represent a topologically nontrivial gauge field background.« less

  14. The motional Stark effect diagnostic for ITER using a line-shift approach

    SciTech Connect (OSTI)

    Foley, E. L.; Levinton, F. M.; Yuh, H. Y.; Zakharov, L. E.

    2008-10-15

    The United States has been tasked with the development and implementation of a motional Stark effect (MSE) system on ITER. In the harsh ITER environment, MSE is particularly susceptible to degradation, as it depends on polarimetry, and the polarization reflection properties of surfaces are highly sensitive to thin film effects due to plasma deposition and erosion of a first mirror. Here we present the results of a comprehensive study considering a new MSE-based approach to internal plasma magnetic field measurements for ITER. The proposed method uses the line shifts in the MSE spectrum (MSE-LS) to provide a radial profile of the magnetic field magnitude. To determine the utility of MSE-LS for equilibrium reconstruction, studies were performed using the ESC-ERV code system. A near-term opportunity to test the use of MSE-LS for equilibrium reconstruction is being pursued in the implementation of MSE with laser-induced fluorescence on NSTX. Though the field values and beam energies are very different from ITER, the use of a laser allows precision spectroscopy with a similar ratio of linewidth to line spacing on NSTX as would be achievable with a passive system on ITER. Simulation results for ITER and NSTX are presented, and the relative merits of the traditional line polarization approach and the new line-shift approach are discussed.

  15. 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.

  16. Five-minute oscillation power within magnetic elements in the solar atmosphere

    SciTech Connect (OSTI)

    Jain, Rekha; Gascoyne, Andrew; Hindman, Bradley W.; Greer, Benjamin

    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.

  17. Passive magnetic bearing configurations

    DOE Patents [OSTI]

    Post, Richard F.

    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.

  18. Stirling engine power control and motion conversion mechanism

    DOE Patents [OSTI]

    Marks, David T.

    1983-01-01

    A motion conversion device for converting between the reciprocating motion of the pistons in a Stirling engine and the rotating motion of its output shaft, and for changing the stroke and phase of the pistons, includes a lever pivoted at one end and having a cam follower at the other end. The piston rod engages the lever intermediate its ends and the cam follower engages a cam keyed to the output shaft. The lever pivot can be moved to change the length of the moment arm defined between the cam follower and the piston rod the change the piston stroke and force exerted on the cam, and the levers can be moved in opposite directions to change the phase between pistons.

  19. LARGE-SCALE MOTIONS IN THE PERSEUS GALAXY CLUSTER

    SciTech Connect (OSTI)

    Simionescu, A.; Werner, N.; Urban, O.; Allen, S. W.; Fabian, A. C.; Sanders, J. S.; Mantz, A.; Nulsen, P. E. J.; Takei, Y.

    2012-10-01

    By combining large-scale mosaics of ROSAT PSPC, XMM-Newton, and Suzaku X-ray observations, we present evidence for large-scale motions in the intracluster medium of the nearby, X-ray bright Perseus Cluster. These motions are suggested by several alternating and interleaved X-ray bright, low-temperature, low-entropy arcs located along the east-west axis, at radii ranging from {approx}10 kpc to over a Mpc. Thermodynamic features qualitatively similar to these have previously been observed in the centers of cool-core clusters, and were successfully modeled as a consequence of the gas sloshing/swirling motions induced by minor mergers. Our observations indicate that such sloshing/swirling can extend out to larger radii than previously thought, on scales approaching the virial radius.

  20. MAGNETIC RECORDING HEAD

    DOE Patents [OSTI]

    Merrill, L.C.

    1958-06-17

    An electromagetic recording head is described for simultaneous recording of a plurality of signals within a small space on a magnetically semsitized medium. Basically the head structure comprises a non-magnetic centerpiece provided with only first and second groups of spaced cut-out slots respectively on opposite sides of the centerpiece. The two groups of slots are in parallel alignment and the slots of one group are staggered with respect to the slots of the other group so that one slot is not directly opposite another slot. Each slot has a magnet pole piece disposed therein and cooperating with a second pole and coil to provide a magnetic flux gap at the upper end of the slot. As a tape is drawn over the upper end of the centerpiece the individual magnetic circuits are disposed along its width to provide means for simultaneously recording information on separate portions, tracks. of the tape.

  1. 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.

  2. 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.

  3. Novel magnets and superconductors studied by high precision magnetic...

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

    Novel magnets and superconductors studied by high precision magnetic susceptometer under pressure An Inductor-capacitor circuit (LC circuit) is a simple, text-book level electric...

  4. Motion of charged test particles in Reissner-Nordstroem spacetime

    SciTech Connect (OSTI)

    Pugliese, Daniela; Quevedo, Hernando; Ruffini, Remo

    2011-05-15

    We investigate the circular motion of charged test particles in the gravitational field of a charged mass described by the Reissner-Nordstroem spacetime. We study in detail all the spatial regions where circular motion is allowed around either black holes or naked singularities. The effects of repulsive gravity are discussed by finding all the circles at which a particle can have vanishing angular momentum. We show that the geometric structure of stable accretion disks, made of only test particles moving along circular orbits around the central body, allows us to clearly distinguish between black holes and naked singularities.

  5. Lensless Imaging of Magnetic Nanostructures

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

    Lensless Imaging of Magnetic Nanostructures Lensless Imaging of Magnetic Nanostructures Print Wednesday, 28 March 2012 00:00 Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine. By studying the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the

  6. SU-C-17A-05: Quantification of Intra-Fraction Motion of Breast Tumors Using Cine-MRI

    SciTech Connect (OSTI)

    Heijst, T van; Philippens, M; Bongard, D van den; Asselen, B van; Lagendijk, J; Kleijnen, J; Hartogh, M den

    2014-06-01

    Purpose: Magnetic resonance imaging (MRI) enables direct characterization of intra-fraction motion ofbreast tumors, due to high softtissue contrast and geometric accuracy. The purpose is to analyzethis motion in early-stage breast-cancer patients using pre-operative supine cine-MRI. Methods: MRI was performed in 12 female early-stage breast-cancer patients on a 1.5-T Ingenia (Philips)wide-bore scanner in supine radiotherapy (RT) position, prior to breast-conserving surgery. Twotwodimensional (2D) T2-weighted balanced fast-field echo (cine-MRI) sequences were added tothe RT protocol, oriented through the tumor. They were alternately acquired in the transverse andsagittal planes, every 0.3 s during 1 min. A radiation oncologist delineated gross target volumes(GTVs) on 3D contrast-enhanced MRI. Clinical target volumes (CTV = GTV + 15 mm isotropic)were generated and transferred onto the fifth time-slice of the time-series, to which subsequents lices were registered using a non-rigid Bspline algorithm; delineations were transformed accordingly. To evaluate intra-fraction CTV motion, deformation fields between the transformed delineations were derived to acquire the distance ensuring 95% surface coverage during scanning(P95%), for all in-plane directions: anteriorposterior (AP), left-right (LR), and caudal-cranial(CC). Information on LR was derived from transverse scans, CC from sagittal scans, AP fromboth sets. Results: Time-series with registration errors - induced by motion artifacts - were excluded by visual inspection. For our analysis, 11 transverse, and 8 sagittal time-series were taken into account. Themedian P95% calculated in AP (19 series), CC (8), and LR (11) was 1.8 mm (range: 0.94.8), 1.7mm (0.83.6), and 1.0 mm (0.63.5), respectively. Conclusion: Intra-fraction motion analysis of breast tumors was achieved using cine-MRI. These first results show that in supine RT position, motion amplitudes are limited. This information can be used for adaptive RT planning, and to develop preoperative partial-breast RT strategies, such asablative RT for early-stage breast-cancer patients.

  7. Motion as perturbation. II. Development of the method for dosimetric analysis of motion effects with fixed-gantry IMRT

    SciTech Connect (OSTI)

    Nelms, Benjamin E.; Opp, Daniel; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir

    2014-06-15

    Purpose: In this work, the feasibility of implementing a motion-perturbation approach to accurately estimate volumetric dose in the presence of organ motionpreviously demonstrated for VMAT-is studied for static gantry IMRT. The method's accuracy is improved for the voxels that have very low planned dose but acquire appreciable dose due to motion. The study describes the modified algorithm and its experimental validation and provides an example of a clinical application. Methods: A contoured region-of-interest is propagated according to the predefined motion kernel throughout time-resolved 4D phantom dose grids. This timed series of 3D dose grids is produced by the measurement-guided dose reconstruction algorithm, based on an irradiation of a staticARCCHECK (AC) helical dosimeter array (Sun Nuclear Corp., Melbourne, FL). Each moving voxel collects dose over the dynamic simulation. The difference in dose-to-moving voxel vs dose-to-static voxel in-phantom forms the basis of a motion perturbation correction that is applied to the corresponding voxel in the patient dataset. A new method to synchronize the accelerator and dosimeter clocks, applicable to fixed-gantry IMRT, was developed. Refinements to the algorithm account for the excursion of low dose voxels into high dose regions, causing appreciable dose increase due to motion (LDVE correction). For experimental validation, four plans using TG-119 structure sets and objectives were produced using segmented IMRT direct machine parameters optimization in Pinnacle treatment planning system (v. 9.6, Philips Radiation Oncology Systems, Fitchburg, WI). All beams were delivered with the gantry angle of 0. Each beam was delivered three times: (1) to the static AC centered on the room lasers; (2) to a static phantom containing a MAPCHECK2 (MC2) planar diode array dosimeter (Sun Nuclear); and (3) to the moving MC2 phantom. The motion trajectory was an ellipse in the IEC XY plane, with 3 and 1.5 cm axes. The period was 5 s, with the resulting average motion speed of 1.45 cm/s. The motion-perturbed high resolution (2 mm voxel) volumetric dose grids on the MC2 phantom were generated for each beam. From each grid, a coronal dose plane at the detector level was extracted and compared to the corresponding moving MC2 measurement, using gamma analysis with both global (G) and local (L) dose-error normalization. Results: Using the TG-119 criteria of (3%G/3 mm), per beam average gamma analysis passing rates exceeded 95% in all cases. No individual beam had a passing rate below 91%. LDVE correction eliminated systematic disagreement patterns at the beams aperture edges. In a representative example, application of LDVE correction improved (2%L/2 mm) gamma analysis passing rate for an IMRT beam from 74% to 98%. Conclusions: The effect of motion on the moving region-of-interest IMRT dose can be estimated with a standard, static phantom QA measurement, provided the motion characteristics are independently known from 4D CT or otherwise. The motion-perturbed absolute dose estimates were validated by the direct planar diode array measurements, and were found to reliably agree with them in a homogeneous phantom.

  8. Lensless Imaging of Magnetic Nanostructures

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

    in medicine. By studying the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important...

  9. Magnetic nematicity: A debated origin

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

    Vaknin, David

    2016-01-22

    Different experimental studies based on nuclear magnetic resonance and inelastic neutron scattering reach opposing conclusions in regards to the origin of magnetic nematicity in iron chalcogenides.

  10. Magnetic Refrigeration | GE Global Research

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

    Johnson, a materials scientist and project leader on GE's magnetic refrigeration project. ... materials would further improve the competitiveness of magnetic refrigeration technology. ...

  11. Speed Limit of Magnetic Recording

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

    from the original magnetization direction can be distinguished as changes in the grey scale contrast. In our images the original magnetization direction corresponds to light...

  12. 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...

  13. Lensless Imaging of Magnetic Nanostructures

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

    useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine. By studying the basics of magnetism,...

  14. 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...

  15. Lensless Imaging of Magnetic Nanostructures

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

    the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies....

  16. Barriers in the transition to global chaos in collisionless magnetic reconnection. II. Field line spectroscopy

    SciTech Connect (OSTI)

    Borgogno, D.; Grasso, D.; Pegoraro, F.; Schep, T. J.

    2011-10-15

    The transitional phase from local to global chaos in the magnetic field of a reconnecting current layer is investigated. The identification of the ridges in the field of the finite time Lyapunov exponent as barriers to the field line motion is carried out adopting the technique of field line spectroscopy to analyze the radial position of a field line while it winds its way through partial stochastic layers and to compare the frequencies of the field line motion with the corresponding frequencies of the distinguished hyperbolic field lines that are the nonlinear generalizations of linear X-lines.

  17. Magnetic field generator

    DOE Patents [OSTI]

    Krienin, Frank (Shoreham, NY)

    1990-01-01

    A magnetic field generating device provides a useful magnetic field within a specific retgion, while keeping nearby surrounding regions virtually field free. By placing an appropriate current density along a flux line of the source, the stray field effects of the generator may be contained. One current carrying structure may support a truncated cosine distribution, and it may be surrounded by a current structure which follows a flux line that would occur in a full coaxial double cosine distribution. Strong magnetic fields may be generated and contained using superconducting cables to approximate required current surfaces.

  18. Moment free toroidal magnet

    DOE Patents [OSTI]

    Bonanos, Peter

    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.

  19. CORRELATING ELECTRONIC AND VIBRATIONAL MOTIONS IN CHARGE TRANSFER SYSTEMS

    SciTech Connect (OSTI)

    Khalil, Munira

    2014-06-27

    The goal of this research program was to measure coupled electronic and nuclear motions during photoinduced charge transfer processes in transition metal complexes by developing and using novel femtosecond spectroscopies. The scientific highlights and the resulting scientific publications from the DOE supported work are outlined in the technical report.

  20. Motion to intervene and comments of the energy services group...

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

    group of Hydro-Quebec and H.Q. Energy Services (U.S.) Inc, on FE 99-1 Motion to intervene and comments of the energy services group of Hydro-Quebec and H.Q. Energy Services (U.S.) ...

  1. Interfacial dislocation motion and interactions in single-crystal superalloys

    SciTech Connect (OSTI)

    Liu, B.; Raabe, D.; Roters, F.; Arsenlis, A.

    2014-10-01

    The early stage of high-temperature low-stress creep in single-crystal superalloys is characterized by the rapid development of interfacial dislocation networks. Although interfacial motion and dynamic recovery of these dislocation networks have long been expected to control the subsequent creep behavior, direct observation and hence in-depth understanding of such processes has not been achieved. Incorporating recent developments of discrete dislocation dynamics models, we simulate interfacial dislocation motion in the channel structures of single-crystal superalloys, and investigate how interfacial dislocation motion and dynamic recovery are affected by interfacial dislocation interactions and lattice misfit. Different types of dislocation interactions are considered: self, collinear, coplanar, Lomer junction, glissile junction, and Hirth junction. The simulation results show that strong dynamic recovery occurs due to the short-range reactions of collinear annihilation and Lomer junction formation. The misfit stress is found to induce and accelerate dynamic recovery of interfacial dislocation networks involving self-interaction and Hirth junction formation, but slow down the steady interfacial motion of coplanar and glissile junction forming dislocation networks. The insights gained from these simulations on high-temperature low-stress creep of single-crystal superalloys are also discussed.

  2. The universal criterion for switching a magnetic vortex core in soft magnetic nanodots

    SciTech Connect (OSTI)

    Lee, K.-S.; Kim, S.-K.; Yu, Y.-S.; Choi, Y.-S.; Guslienko, K. Y.; Jung, H.; Fischer, P.

    2008-10-01

    The universal criterion for ultrafast vortex core switching between core-up and -down vortex bi-states in soft magnetic nanodots was empirically investigated by micromagnetic simulations and combined with an analytical approach. Vortex-core switching occurs whenever the velocity of vortex core motion reaches a critical value, which is {nu}{sub c} = 330 {+-} 37 m/s for Permalloy, as estimated from numerical simulations. This critical velocity was found to be {nu}{sub c} = {eta}{sub c}{gamma} {radical}A{sub ex} with A{sub ex} the exchange stiffness, {gamma} the gyromagnetic ratio, and an estimated proportional constant {eta}{sub c} = 1.66 {+-} 0.18. This criterion does neither depend on driving force parameters nor on the dimension or geometry of the magnetic specimen. The phase diagrams for the vortex core switching criterion and its switching time with respect to both the strength and angular frequency of circular rotating magnetic fields were derived, which offer practical guidance for implementing vortex core switching into future solid state information storage devices.

  3. 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.

  4. Permanent magnet energy conversion machine with magnet mounting arrangement

    DOE Patents [OSTI]

    Hsu, John S.; Adams, Donald J.

    1999-01-01

    A hybrid permanent magnet dc motor includes three sets of permanent magnets supported by the rotor and three sets of corresponding stators fastened to the surrounding frame. One set of magnets operates across a radial gap with a surrounding radial gap stator, and the other two sets of magnets operate off the respective ends of the rotor across respective axial gaps.

  5. Motion of small bodies in classical field theory

    SciTech Connect (OSTI)

    Gralla, Samuel E. [Enrico Fermi Institute and Department of Physics University of Chicago 5640 S. Ellis Avenue, Chicago, Illinois 60637 (United States)

    2010-04-15

    I show how prior work with R. Wald on geodesic motion in general relativity can be generalized to classical field theories of a metric and other tensor fields on four-dimensional spacetime that (1) are second-order and (2) follow from a diffeomorphism-covariant Lagrangian. The approach is to consider a one-parameter-family of solutions to the field equations satisfying certain assumptions designed to reflect the existence of a body whose size, mass, and various charges are simultaneously scaled to zero. (That such solutions exist places a further restriction on the class of theories to which our results apply.) Assumptions are made only on the spacetime region outside of the body, so that the results apply independent of the body's composition (and, e.g., black holes are allowed). The worldline 'left behind' by the shrinking, disappearing body is interpreted as its lowest-order motion. An equation for this worldline follows from the 'Bianchi identity' for the theory, without use of any properties of the field equations beyond their being second-order. The form of the force law for a theory therefore depends only on the ranks of its various tensor fields; the detailed properties of the field equations are relevant only for determining the charges for a particular body (which are the ''monopoles'' of its exterior fields in a suitable limiting sense). I explicitly derive the force law (and mass-evolution law) in the case of scalar and vector fields, and give the recipe in the higher-rank case. Note that the vector force law is quite complicated, simplifying to the Lorentz force law only in the presence of the Maxwell gauge symmetry. Example applications of the results are the motion of 'chameleon' bodies beyond the Newtonian limit, and the motion of bodies in (classical) non-Abelian gauge theory. I also make some comments on the role that scaling plays in the appearance of universality in the motion of bodies.

  6. 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.

  7. 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.

  8. Magnetic Materials Group

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

    4-ID-C: Soft X-ray Magnetic Spectroscopy This beamline operates in the soft x-ray energy spectrum (500 - 2700 eV) using an electromagnetic helical undulator to provide circularly...

  9. Magnetic separation of algae

    DOE Patents [OSTI]

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  10. Magnetic gripper device

    DOE Patents [OSTI]

    Meyer, Ross E.

    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.

  11. Low Temperature Scaling of the Susceptibility of Ni Films

    SciTech Connect (OSTI)

    Song, X. H.; Zhang, Xiaoguang; Fan, J.; Jin, Y. R.; Su, S. K.; Zhang, D. L.

    2008-03-01

    Measurement of low field ac susceptibility of Ni thin films over the temperature range 5-300K reveals a surprising power law scaling. The temperature dependent part of the normalized susceptibility, $\\chi_\\parallel/M_S-\\chi_{\\rm rot}/M_S$, where $\\chi_\\parallel$ is the initial susceptibility for in-plane magnetization, $\\chi_{\\rm rot}$ is the domain rotation contribution, and $M_S$ is the saturation magnetization, scales with the nonlinear reduced temperature as $t^{-2}$ over the entire temperature range, where $t=(T-T_C)/(T+T_C)$ and $T_C$ is the Curie temperature. Thickness and reduced temperature dependences are completely decoupled. This result implies that domain wall motion does not contribute to the low field susceptibility.

  12. 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.

  13. Magnetic coupling device

    DOE Patents [OSTI]

    Nance, Thomas A.

    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.

  14. 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.

  15. MAGNETIC NEUTRON SCATTERING

    SciTech Connect (OSTI)

    ZALIZNYAK,I.A.; LEE,S.H.

    2004-07-30

    Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron magnetic scattering is similar to the cross-section of nuclear scattering by short-range nuclear forces, and is large enough to provide measurable scattering by the ordered magnetic structures and electron spin fluctuations. In the half-a-century or so that has passed since neutron beams with sufficient intensity for scattering applications became available with the advent of the nuclear reactors, they have became indispensable tools for studying a variety of important areas of modern science, ranging from large-scale structures and dynamics of polymers and biological systems, to electronic properties of today's technological materials. Neutron scattering developed into a vast field, encompassing many different experimental techniques aimed at exploring different aspects of matter's atomic structure and dynamics. Modern magnetic neutron scattering includes several specialized techniques designed for specific studies and/or particular classes of materials. Among these are magnetic reflectometry aimed at investigating surfaces, interfaces, and multilayers, small-angle scattering for the large-scale structures, such as a vortex lattice in a superconductor, and neutron spin-echo spectroscopy for glasses and polymers. Each of these techniques and many others offer exciting opportunities for examining magnetism and warrant extensive reviews, but the aim of this chapter is not to survey how different neutron-scattering methods are used to examine magnetic properties of different materials. Here, we concentrate on reviewing the basics of the magnetic neutron scattering, and on the recent developments in applying one of the oldest methods, the triple axis spectroscopy, that still is among the most extensively used ones. The developments discussed here are new and have not been coherently reviewed. Chapter 2 of this book reviews magnetic small-angle scattering, and modern techniques of neutron magnetic reflectometry are discussed in Chapter 3.

  16. Freely oriented portable superconducting magnet

    DOE Patents [OSTI]

    Schmierer, Eric N.; Prenger, F. Coyne; Hill, Dallas D.

    2010-01-12

    A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.

  17. Lensless Imaging of Magnetic Nanostructures

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

    Lensless Imaging of Magnetic Nanostructures 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 the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging

  18. Lensless Imaging of Magnetic Nanostructures

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

    Lensless Imaging of Magnetic Nanostructures 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 the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging

  19. Lensless Imaging of Magnetic Nanostructures

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

    Lensless Imaging of Magnetic Nanostructures 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 the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging

  20. Lensless Imaging of Magnetic Nanostructures

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

    Lensless Imaging of Magnetic Nanostructures 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 the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging

  1. Lensless Imaging of Magnetic Nanostructures

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

    Imaging of Magnetic Nanostructures 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 the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging for the

  2. Lensless Imaging of Magnetic Nanostructures

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

    Imaging of Magnetic Nanostructures 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 the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging for the

  3. Lensless Imaging of Magnetic Nanostructures

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

    Lensless Imaging of Magnetic Nanostructures 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 the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging

  4. Lensless Imaging of Magnetic Nanostructures

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

    Lensless Imaging of Magnetic Nanostructures 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 the basics of magnetism, scientists aim to better understand the fundamental physical principles that govern magnetic systems, perhaps leading to important new technologies. The high brightness and coherence of the ALS's soft x-rays have enabled scientists to apply lensless x-ray imaging

  5. Connecting apparatus for limited rotary or rectilinear motion

    DOE Patents [OSTI]

    Hardin, Jr., Roy T.

    1981-11-10

    Apparatus for providing connection between two members movable in a horizontal plane with respect to each other in a rotary or linear fashion. The apparatus includes a set of horizontal shelves affixed to each of the two members, vertically aligned across a selected gap. A number of cables or hoses, for electrical, hydraulic or pneumatic connection are arranged on the aligned shelves in a U-shaped loop, connected through their extremities to the two members, so that through a sliding motion portions of the cable are transferred from one shelf to the other, across the gap, upon relative motion of the members. The apparatus is particularly adaptable to the rotating plugs of the reactor vessel head of a nuclear reactor.

  6. Clearance detector and method for motion and distance

    DOE Patents [OSTI]

    Xavier, Patrick G.

    2011-08-09

    A method for correct and efficient detection of clearances between three-dimensional bodies in computer-based simulations, where one or both of the volumes is subject to translation and/or rotations. The method conservatively determines of the size of such clearances and whether there is a collision between the bodies. Given two bodies, each of which is undergoing separate motions, the method utilizes bounding-volume hierarchy representations for the two bodies and, mappings and inverse mappings for the motions of the two bodies. The method uses the representations, mappings and direction vectors to determine the directionally furthest locations of points on the convex hulls of the volumes virtually swept by the bodies and hence the clearance between the bodies, without having to calculate the convex hulls of the bodies. The method includes clearance detection for bodies comprising convex geometrical primitives and more specific techniques for bodies comprising convex polyhedra.

  7. Characterization of Slow Orbit Motion in the SPEAR3

    SciTech Connect (OSTI)

    Sunilkumar, Nikita; Gassner, Georg; Safranek, James; Yan, Yiton; /SLAC

    2012-07-09

    SPEAR3 is a third-generation synchrotron light source storage ring. The beam stability requirements are {approx}10% of the beam size, which is about 1 micron in the vertical plane. Hydrostatic level system (HLS) measurements show that the height of the SPEAR3 tunnel floor varies by tens of microns daily. We present analysis of the HLS data, including accounting for common-mode tidal motion. We discuss the results of experiments done to determine the primary driving source of ground motion. We painted the accelerator tunnel walls white; we temporarily installed Mylar over the asphalt in the center of the accelerator; and we put Mylar over a section of the tunnel walls.

  8. Tropical cyclone motion and recurvature in TCM-90. Master's thesis

    SciTech Connect (OSTI)

    Fitzpatrick, M.E.

    1992-01-01

    Rawinsonde and satellite data collected during the Tropical Cyclone Motion (TCM90) experiment, which was conducted during the summer of 1990 in the Western North pacific, is used to examine tropical cyclone steering motion and recurvature. TCM-90 composite results are compared with those found in a composite study using twenty-one years (1957-77) of Western North Pacific rawinsonde data during the same August-September period and also for all months during this same 21-year period. Both data sets indicate that the composite deep-layer-mean (850-300 mb) winds 5-7 deg from the cyclone center provide an important component of the steering flow for tropical cyclones. However, despite the rawinsonde data enhancements of the TCM-90 experiment, data limitations prevented an accurate observation of steering flow conditions at individual time periods or for the average of only 5-10 time periods when composited together.

  9. Intrinsic Feature-Based Pose Measurement for Medical Imaging Motion

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

    Compensation - Energy Innovation Portal Find More Like This Return to Search Intrinsic Feature-Based Pose Measurement for Medical Imaging Motion Compensation Oak Ridge National Laboratory Contact ORNL About This Technology Publications: PDF Document Publication 11-G00260_ID2341.pdf (497 KB) Technology Marketing SummaryTomographic imaging of awake, unrestrained animals or humans during a scan can result in blurring and unusable 3D images due to movement by the subject. This invention

  10. Motion of Robert G. Burnley, Director the Commonwealth of Virginia

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

    Department of Environmental Quality to Deny the District of Columbia Public Service Commission's Petition Further Analysis of Environmental Impacts of Requested Relief | Department of Energy of Robert G. Burnley, Director the Commonwealth of Virginia Department of Environmental Quality to Deny the District of Columbia Public Service Commission's Petition Further Analysis of Environmental Impacts of Requested Relief Motion of Robert G. Burnley, Director the Commonwealth of Virginia Department

  11. Motion of gravitationally interacting particles in Born-Infeld electrodynamics

    SciTech Connect (OSTI)

    Shkolnik, N.; Mallett, R.L.

    1986-12-15

    The motion of charged particles in the framework of the Einstein-Infeld-Hoffmann method is examined. The Born-Infeld energy-momentum tensor is used on the right-hand side of the gravitational field equations. It is shown that this results in a modified behavior of charged particles. In particular, it leads to a modification of Coulomb's law at small distances. It is also shown that a stable system of two charged particles is possible.

  12. Historical Information H. 6 SeismicIGround Motion Activity

    Office of Legacy Management (LM)

    6 SeismicIGround Motion Activity Book 3 The Effects of the Rulison Event on Buildings and Other Surface Structures DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. I I .* ,a - . . > - . ~ - ..+<#z*:<~:<:~.:$:.y;.$3s, 3898 OFF THE EFFECTS OF THE RULISON EVENT ON BUILDINGS AND OTHER SURFACE STRUCTURES Lloyd A. Lee and Roger E. Skjei January 14, 1970 John A. Blume & Associates Research

  13. Quantifying intra- and inter-fractional motion in breast radiotherapy

    SciTech Connect (OSTI)

    Jones, Scott; Fitzgerald, Rhys; Owen, Rebecca; Ramsay, Jonathan

    2015-03-15

    The magnitude of intra- and inter-fractional variation in the set up of breast cancer patients treated with tangential megavoltage photon beams was investigated using an electronic portal imaging device (EPID). Daily cine-EPID images were captured during delivery of the tangential fields for ten breast cancer patients treated in the supine position. Measurements collected from each image included the central lung distance (CLD), central flash distance (CFD), superior axial measurement (SAM) and the inferior axial measurement (IAM). The variation of motion within a fraction (intra-fraction) and the variation between fractions (inter-fraction) was analysed to quantify set up variation and motion due to respiration. Altogether 3775 EPID images were collected from 10 patients. The effect of respiratory motion during treatment was <0.1 cm standard deviation (SD) in the anterior–posterior (AP) direction. The inter-fraction movement caused by variations in daily set up was larger at 0.28 cm SD in the AP direction. Superior–inferior (SI) variation was more difficult to summarise and proved unreliable as the measurements were taken to an ambiguous point on the images. It was difficult to discern true SI movement from that implicated by AP movement. There is minimal intra-fractional chest wall motion due to respiration during treatment. Inter-fractional variation was larger, however, on average it remained within departmental tolerance (0.5 cm) for set up variations. This review of our current breast technique provides confidence in the feasibility of utilising advanced treatment techniques (field-in-field, intensity modulated radiotherapy or volumetric modulated arc therapy) following a review of the current imaging protocol.

  14. Coupled beam motion in a storage ring with crab cavities

    SciTech Connect (OSTI)

    Huang, Xiaobiao

    2015-11-16

    We studied the coupled beam motion in a storage ring between the transverse and longitudinal directions introduced by crab cavities. Analytic form of the linear decoupling transformation is derived. Also, the equilibrium bunch distribution in an electron storage ring with a crab cavity is given, including contribution to the eigen-emittance induced by the crab cavity. Application to the short pulse generation scheme using crab cavities [1] is considered.

  15. 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,

  16. Motion to Intervene Out of Time of Sumas Energy 2, Inc on Proposed...

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

    Motion to Intervene Out of Time of Sumas Energy 2, Inc on Proposed Open-Access Requirement ... Motion to intervene out ouf time by Sumas Energy 2, Inc on the proposed change in ...

  17. Active magnetic regenerator

    DOE Patents [OSTI]

    Barclay, J.A.; Steyert, W.A.

    1981-01-27

    An apparatus and method for refrigeration are disclosed which provides efficient refrigeration over temperature ranges in excess of 20/sup 0/C and which requires no maintenance and is, therefore, usable on an unmanned satellite. The apparatus comprises a superconducting magnet which may be solenoidal. A piston comprising a substance such as a rare earth substance which is maintained near its Curie temperature reciprocates through the bore of the solenoidal magnet. A magnetic drive rod is connected to the piston and appropriate heat sinks are connected thereto. The piston is driven by a suitable mechanical drive such as an electric motor and cam. In practicing the invention, the body of the piston is magnetized and demagnetized as it moves through the magnetic field of the solenoid to approximate any of the following cycles or a condition thereof as well as, potentially, other cycles: Brayton, Carnot, Ericsson, and Stirling. Advantages of the present invention include: that refrigeration can be accomplished over at least a 20/sup 0/C scale at superconducting temperatures as well as at more conventional temperatures; very high efficiency, high reliability, and small size. (LCL)

  18. Magnetic reconnection launcher

    DOE Patents [OSTI]

    Cowan, Maynard

    1989-01-01

    An electromagnetic launcher includes a plurality of electrical stages which are energized sequentially in synchrony with the passage of a projectile. Each stage of the launcher includes two or more coils which are arranged coaxially on either closed-loop or straight lines to form gaps between their ends. The projectile has an electrically conductive gap-portion that passes through all the gaps of all the stages in a direction transverse to the axes of the coils. The coils receive an electric current, store magnetic energy, and convert a significant portion of the stored magnetic energy into kinetic energy of the projectile by magnetic reconnection as the gap portion of the projectile moves through the gap. The magnetic polarity of the opposing coils is in the same direction, e.g. N-S-N-S. A gap portion of the projectile may be made from aluminum and is propelled by the reconnection of magnetic flux stored in the coils which causes accelerating forces to act upon the projectile at both the rear vertical surface of the projectile and at the horizontal surfaces of the projectile near its rear. The gap portion of the projectile may be flat, rectangular and longer than the length of the opposing coils and fit loosely within the gap between the opposing coils.

  19. METHOD AND APPARATUS FOR DETERMINING CHARGED PARTICLE MOTION

    DOE Patents [OSTI]

    Kerns, Q.A.

    1959-08-01

    An analog system for determining the motion of charged particles in three dimensional electrical fields is described. A model electrode structure is formed and potentials are applied to the electrodes to provide an analog of the field which is to be studied. To simulate charged particles within the model, conducting spheres are placed at points from which particle motion is to be traced. To free the spheres from gravitational attraction in order that they will be electrostatically accelerated through the model, the apparatus is suspended and dropped. During the pericd that the model is dropping the spheres move through the electrcde structure with a motion corresponding to that of particles in the real system. The model is photographed in the course of falling so that the instantaneous position of the spheres within the simulated field at selected times may be observed and measured. The device thus gives data of particles in the real system. The model is photographed in the course of falling so that the instantaneous position of the spheres within the simulated field at selected times may be observed and measured. The device thus gives data which frequently can otherwise be obtained only with a digital computer.

  20. Automated-In-Motion Vehicle Evaluation Environment (AIMVEE)

    Energy Science and Technology Software Center (OSTI)

    2006-05-04

    The AIMVEE/WIM system electronically retrieves deployment information, identifies vehicle automatically, and determines total weight, individual wheel weight, individual axle weights, axle spacing, and center-of-balance for any wheeled vehicle in motion. The AIMVEE/WIM system can also perform these functions statically for both wheel vehicles and cargo with information. The AIMVEE/WIM system incorporates digital images and applies cubing algorithms to determine length, width, height for cubic dimensions of both vehicle and cargo. Once all this information ismore » stored, it electronically links to data collection and dissemination systems to provide “actual” weight and measurement information for planning, deployment, and in-transit visibility. The Static Scale Conversion (SSC) system is an unique enhancement to the AIMVEE/WIM system. It enables a SSC to weigh and measure vehicles and cargo dynamically (i.e., as they pass over the large scale and is included in the AIMVEE computer code base. The material to be copyrighted is the Automated-In-Motion Vehicle Evaluation Environment (AIMVEE)/Weigh-In-Motion User Training and Testing material. It includes instructional material in the set-up, operation and tear-down of the AIMVEE/WIM system. It also includes a final exam associated with the training.« less

  1. Giant atomic displacement at a magnetic phase transition in metastable Mn3O4

    SciTech Connect (OSTI)

    Hirai, Shigeto; Moreira Dos Santos, Antonio F; Shapiro, Max C; Molaison, Jamie J; Pradhan, Neelam; Guthrie, Malcolm; Tulk, Christopher A; Fisher, Ian R; Mao, Wendy

    2013-01-01

    We present x-ray, neutron scattering, and heat capacity data that reveal a coupled first-order magnetic and structural phase transition of the metastable mixed-valence postspinel compound Mn3O4 at 210 K. Powder neutron diffraction measurements reveal a magnetic structure in which Mn3+ spins align antiferromagnetically along the edge-sharing a axis, with a magnetic propagation vector k = [1/2,0,0]. In contrast, the Mn2+ spins, which are geometrically frustrated, do not order until a much lower temperature. Although the Mn2+ spins do not directly participate in the magnetic phase transition at 210 K, structural refinements reveal a large atomic shift at this phase transition, corresponding to a physical motion of approximately 0.25 angstrom, even though the crystal symmetry remains unchanged. This "giant" response is due to the coupled effect of built-in strain in the metastable postspinel structure with the orbital realignment of the Mn3+ ion.

  2. Example-Based Automatic Music-Driven Conventional Dance Motion Synthesis

    SciTech Connect (OSTI)

    Xu, Songhua; Fan, Rukun; Geng, Weidong

    2012-01-01

    We introduce a novel method for synthesizing dance motions that follow the emotions and contents of a piece of music. Our method employs a learning-based approach to model the music to motion mapping relationship embodied in example dance motions along with those motions' accompanying background music. A key step in our method is to train a music to motion matching quality rating function through learning the music to motion mapping relationship exhibited in synchronized music and dance motion data, which were captured from professional human dance performance. To generate an optimal sequence of dance motion segments to match with a piece of music, we introduce a constraint-based dynamic programming procedure. This procedure considers both music to motion matching quality and visual smoothness of a resultant dance motion sequence. We also introduce a two-way evaluation strategy, coupled with a GPU-based implementation, through which we can execute the dynamic programming process in parallel, resulting in significant speedup. To evaluate the effectiveness of our method, we quantitatively compare the dance motions synthesized by our method with motion synthesis results by several peer methods using the motions captured from professional human dancers' performance as the gold standard. We also conducted several medium-scale user studies to explore how perceptually our dance motion synthesis method can outperform existing methods in synthesizing dance motions to match with a piece of music. These user studies produced very positive results on our music-driven dance motion synthesis experiments for several Asian dance genres, confirming the advantages of our method.

  3. Seismic Ground Motion Response Using SHAKE, EERA and NERA for SRS Soil

    Office of Environmental Management (EM)

    Profile | Department of Energy Seismic Ground Motion Response Using SHAKE, EERA and NERA for SRS Soil Profile Seismic Ground Motion Response Using SHAKE, EERA and NERA for SRS Soil Profile Seismic Ground 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 Rucker Williams, PE - Geotechnical Engineering Lead October 22, 2014 PDF icon Seismic Ground Motion Response Using

  4. Superconducting magnetic coil

    DOE Patents [OSTI]

    Aized, D.; Schwall, R.E.

    1999-06-22

    A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil. 15 figs.

  5. Superconducting magnetic coil

    DOE Patents [OSTI]

    Aized, Dawood; Schwall, Robert E.

    1996-06-11

    A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil.

  6. Superconducting magnetic coil

    DOE Patents [OSTI]

    Aized, Dawood; Schwall, Robert E.

    1999-06-22

    A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil.

  7. Magnetic nanoparticle temperature estimation

    SciTech Connect (OSTI)

    Weaver, John B.; Rauwerdink, Adam M.; Hansen, Eric W.

    2009-05-15

    The authors present a method of measuring the temperature of magnetic nanoparticles that can be adapted to provide in vivo temperature maps. Many of the minimally invasive therapies that promise to reduce health care costs and improve patient outcomes heat tissue to very specific temperatures to be effective. Measurements are required because physiological cooling, primarily blood flow, makes the temperature difficult to predict a priori. The ratio of the fifth and third harmonics of the magnetization generated by magnetic nanoparticles in a sinusoidal field is used to generate a calibration curve and to subsequently estimate the temperature. The calibration curve is obtained by varying the amplitude of the sinusoidal field. The temperature can then be estimated from any subsequent measurement of the ratio. The accuracy was 0.3 deg. K between 20 and 50 deg. C using the current apparatus and half-second measurements. The method is independent of nanoparticle concentration and nanoparticle size distribution.

  8. Ginzburg-Landau theory for skyrmions in inversion-symmetric magnets with competing interactions

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

    Lin, Shi-Zeng; Hayami, Satoru

    2016-02-01

    Magnetic skyrmions have attracted considerable attention recently for their huge potential in spintronic applications. Generally skyrmions are big compared to the atomic lattice constant, which allows for the Ginzburg-Landau type description in the continuum limit. This description successfully captures the main experimental observations on skyrmions in B20 compound without inversion symmetry. Skyrmions can also exist in inversion-symmetric magnets with competing interactions. Here, we derive a general Ginzburg-Landau theory for skyrmions in these magnets valid in the long-wavelength limit. We study the unusual static and dynamical properties of skyrmions based on the derived Ginzburg-Landau theory. We show that an easy axismore » spin anisotropy is sufficient to stabilize a skyrmion lattice. Interestingly, the skyrmion in inversion-symmetric magnets has a new internal degree of freedom associated with the rotation of helicity, i.e., the “spin” of the skyrmion as a particle, in addition to the usual translational motion of skyrmions (orbital motion). The orbital and spin degree of freedoms of an individual skyrmion can couple to each other, and give rise to unusual behavior that is absent for the skyrmions stabilized by the Dzyaloshinskii-Moriya interaction. Finally, the derived Ginzburg-Landau theory provides a convenient and general framework to discuss skyrmion physics and will facilitate the search for skyrmions in inversion-symmetric magnets.« less

  9. Magnetic imager and method

    DOE Patents [OSTI]

    Powell, James; Reich, Morris; Danby, Gordon

    1997-07-22

    A magnetic imager 10 includes a generator 18 for practicing a method of applying a background magnetic field over a concealed object, with the object being effective to locally perturb the background field. The imager 10 also includes a sensor 20 for measuring perturbations of the background field to detect the object. In one embodiment, the background field is applied quasi-statically. And, the magnitude or rate of change of the perturbations may be measured for determining location, size, and/or condition of the object.

  10. Magnetic imager and method

    DOE Patents [OSTI]

    Powell, J.; Reich, M.; Danby, G.

    1997-07-22

    A magnetic imager includes a generator for practicing a method of applying a background magnetic field over a concealed object, with the object being effective to locally perturb the background field. The imager also includes a sensor for measuring perturbations of the background field to detect the object. In one embodiment, the background field is applied quasi-statically. And, the magnitude or rate of change of the perturbations may be measured for determining location, size, and/or condition of the object. 25 figs.

  11. Automated-In-Motion Vehicle Evaluation Environment (AIMVEE) Weigh-In Motion (WIM) User Training and Testing

    Energy Science and Technology Software Center (OSTI)

    2006-05-04

    The AIMVEE/WIM system electronically retrieves deployment information, identifies vehicle automatically, and determines total weight, individual wheel weight, individual axle weights, axle spacing, and center-of-balance for any wheeled vehicle in motion. The AIMVEE/WIM system can also perform these functions statically for both wheel vehicles and cargo with information. The AIMVEE/WIM system incorporates digital images and applies cubing algorithms to determine length, width, height for cubic dimensions of both vehicle and cargo. Once all this information ismore » stored, it electronically links to data collection and dissemination systems to provide “actual” weight and measurement information for planning, deployment, and in-transit visibility. The Static Scale Conversion (SSC) system is an unique enhancement to the AIMVEE/WIM system. It enables a SSC to weigh and measure vehicles and cargo dynamically (i.e., as they pass over the large scale and is included in the AIMVEE computer code base. The material to be copyrighted is the Automated-In-Motion Vehicle Evaluation Environment (AIMVEE)/Weigh-In-Motion User Training and Testing material. It includes instructional material in the set-up, operation and tear-down of the AIMVEE/WIM system. It also includes a final exam associated with the training.« less

  12. COLLOQUIUM: Space Physics and the Role of Magnetic Reconnection in Space

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

    Weather | Princeton Plasma Physics Lab June 11, 2014, 4:00pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: Space Physics and the Role of Magnetic Reconnection in Space Weather Professor Vassilis Angelopoulous UCLA Earth's magnetosphere is buffeted by the solar wind. The interaction transfers energy electro-mechanically into Earth's environment and sets the magnetospheric and ionospheric plasma into motion. The energy is ultimately converted to heat raising the scale-height of the

  13. Study on the Mechanical Instability of MICE Coupling Magnets

    SciTech Connect (OSTI)

    Wang, Li; Pan, Heng; Gou, Xing Long; Wu, Hong; Zheng, Shi Xian; Green, Michael A

    2011-05-04

    The superconducting coupling solenoid magnet is one of the key equipment in the Muon Ionization Cooling Experiment (MICE). The coil has an inner radius of 750 mm, length of 281 mm and thickness of 104 mm at room temperature. The peak induction in the coil is about 7.3 T with a full current of 210 A. The mechanical disturbances which might cause the instability of the impregnated superconducting magnet involve the frictional motion between conductors and the cracking of impregnated materials. In this paper, the mechanical instability of the superconducting coupling magnet was studied. This paper presents the numerical calculation results of the minimum quench energy (MQE) of the coupling magnet, as well as the dissipated strain energy in the stress concentration region when the epoxy cracks and the frictional energy caused by 'stick-slip' of the conductor based on the bending theory of beam happens. Slip planes are used in the coupling coil and the frictional energy due to 'slow slip' at the interface of the slip planes was also investigated. The dissipated energy was compared with MQE, and the results show that the cracking of epoxy resin in the region of shear stress concentration is the main factor for premature quench of the coil.

  14. Category:Magnetic Techniques | Open Energy Information

    Open Energy Info (EERE)

    Magnetic Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Magnetic Techniques page? For detailed information on Magnetic...

  15. Tunable Magnetic Regenerator/Refrigerant - Energy Innovation...

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

    Magnetic regenerators utilize the magnetocaloric effect--the ability of a magnetic field to reduce the magnetic part of a solid materials entropy, generating heat, and then ...

  16. Equilibrium magnetic states in individual hemispherical permalloy...

    Office of Scientific and Technical Information (OSTI)

    The magnetization distributions in individual soft magnetic permalloy caps on non-magnetic spherical particles with sizes ranging from 50 to 800 nm are investigated. We ...

  17. Disorder-Induced Microscopic Magnetic Memory

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

    Disorder-Induced Microscopic Magnetic Memory Disorder-Induced Microscopic Magnetic Memory Print Wednesday, 26 October 2005 00:00 The magnetic-recording industry deliberately...

  18. Magnet Motor Corp | Open Energy Information

    Open Energy Info (EERE)

    Magnet Motor Corp Jump to: navigation, search Name: Magnet Motor Corp. Place: Starnberg, Germany Zip: 82319 Sector: Vehicles Product: Magnet motor Corp has been developing and...

  19. Magnetic excitations in Kondo liquid: superconductivity and hidden magnetic

    Office of Scientific and Technical Information (OSTI)

    quantum critical fluctuations (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Magnetic excitations in Kondo liquid: superconductivity and hidden magnetic quantum critical fluctuations Citation Details In-Document Search Title: Magnetic excitations in Kondo liquid: superconductivity and hidden magnetic quantum critical fluctuations We report Knight shift experiments on the superconducting heavy electron material CeCoIn{sub 5} that allow one to track with

  20. Electronic Structure and Magnetism in Diluted Magnetic Semiconductors

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

    Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print Wednesday, 29 November 2006 00:00 The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted

  1. Magnetic excitations in Kondo liquid: superconductivity and hidden magnetic

    Office of Scientific and Technical Information (OSTI)

    quantum critical fluctuations (Journal Article) | SciTech Connect Magnetic excitations in Kondo liquid: superconductivity and hidden magnetic quantum critical fluctuations Citation Details In-Document Search Title: Magnetic excitations in Kondo liquid: superconductivity and hidden magnetic quantum critical fluctuations × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI)

  2. Magnetic Filtration Process, Magnetic Filtering Material, and Method of

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

    Forming Magnetic Filtering Material - Energy Innovation Portal Industrial Technologies Industrial Technologies Find More Like This Return to Search Magnetic Filtration Process, Magnetic Filtering Material, and Method of Forming Magnetic Filtering Material Oak Ridge National Laboratory Contact ORNL About This Technology Technology Marketing SummaryORNL researchers developed a new method for filtering materials and managing wastewater. This invention offers an integrated, intensified process

  3. THE CONTRACTION OF OVERLYING CORONAL LOOP AND THE ROTATING MOTION OF A SIGMOID FILAMENT DURING ITS ERUPTION

    SciTech Connect (OSTI)

    Yan, X. L.; Qu, Z. Q.; Xue, Z. K.; Deng, L. H.; Ma, L.; Kong, D. F.; Liu, J. H.

    2013-06-15

    We present an observation of overlying coronal loop contraction and rotating motion of the sigmoid filament during its eruption on 2012 May 22 observed by the Solar Dynamics Observatory (SDO). Our results show that the twist can be transported into the filament from the lower atmosphere to the higher atmosphere. The successive contraction of the coronal loops was due to a suddenly reduced magnetic pressure underneath the filament, which was caused by the rising of the filament. Before the sigmoid filament eruption, there was a counterclockwise flow in the photosphere at the right feet of the filament and the contraction loops and a convergence flow at the left foot of the filament. The hot and cool materials have inverse motion along the filament before the filament eruption. Moreover, two coronal loops overlying the filament first experienced brightening, expansion, and contraction successively. At the beginning of the rising and rotation of the left part of the filament, the second coronal loop exhibited rapid contraction. The top of the second coronal loop also showed counterclockwise rotation during the contraction process. After the contraction of the second loop, the left part of the filament rotated counterclockwise and expanded toward the right of NOAA AR 11485. During the filament expansion, the right part of the filament also exhibited counterclockwise rotation like a tornado.

  4. Transition from order to chaos, and density limit, in magnetized plasmas

    SciTech Connect (OSTI)

    Carati, A.; Maiocchi, A.; Marino, M.; Galgani, L.; Zuin, M.; Martines, E.

    2012-09-15

    It is known that a plasma in a magnetic field, conceived microscopically as a system of point charges, can exist in a magnetized state, and thus remain confined, inasmuch as it is in an ordered state of motion, with the charged particles performing gyrational motions transverse to the field. Here, we give an estimate of a threshold, beyond which transverse motions become chaotic, the electrons being unable to perform even one gyration, so that a breakdown should occur, with complete loss of confinement. The estimate is obtained by the methods of perturbation theory, taking as perturbing force acting on each electron that due to the so-called microfield, i.e., the electric field produced by all the other charges. We first obtain a general relation for the threshold, which involves the fluctuations of the microfield. Then, taking for such fluctuations, the formula given by Iglesias, Lebowitz, and MacGowan for the model of a one component plasma with neutralizing background, we obtain a definite formula for the threshold, which corresponds to a density limit increasing as the square of the imposed magnetic field. Such a theoretical density limit is found to fit pretty well the empirical data for collapses of fusion machines.

  5. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, L.D.

    1987-02-11

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

  6. Magnetic resonance apparatus

    DOE Patents [OSTI]

    Jackson, Jasper A.; Cooper, Richard K.

    1982-01-01

    Means for producing a region of homogeneous magnetic field remote from the source of the field, wherein two equal field sources are arranged axially so their fields oppose, producing a region near the plane perpendicular to the axis midway between the sources where the radial component of the field goes through a maximum. Near the maximum, the field is homogeneous over prescribed regions.

  7. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, Lance D.

    1988-01-01

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

  8. Magnetic refrigeration apparatus and method

    DOE Patents [OSTI]

    Barclay, John A.; Overton, Jr., William C.; Stewart, Walter F.

    1984-01-01

    The disclosure relates to refrigeration through magnetizing and demagnitizing a body by rotating it within a magnetic field. Internal and external heat exchange fluids and in one embodiment, a regenerator, are used.

  9. Magnetic refrigeration apparatus and method

    DOE Patents [OSTI]

    Barclay, J.A.; Overton, W.C. Jr.; Stewart, W.F.

    The disclosure relates to refrigeration through magnetizing and demagnitizing a body by rotating it within a magnetic field. Internal and external heat exchange fluids and in one embodiment, a regenerator, are used.

  10. Magnetic Materials | Advanced Photon Source

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

    Materials Internal Magnetic Materials The Magnetic Material Group (MMG) is part of the X-ray Science Division (XSD) at the Advanced Photon Source (APS). Our research focuses on the...

  11. Large Magnetization at Carbon Surfaces

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

    Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure...

  12. Magnet Cooldown and Warmup Model

    Energy Science and Technology Software Center (OSTI)

    1995-07-11

    This program evaluates cooldown/warmup performance of an SSC magnet or magnet strings, But can be applied to any other iron coldmass which is cooled or warmed by helium.

  13. Magnetic reconnection launcher

    DOE Patents [OSTI]

    Cowan, M.

    1987-04-06

    An electromagnetic launcher includes a plurality of electrical stages which are energized sequentially in the launcher with the passage of a projectiles. Each stage of the launcher includes two or more coils which are arranged coaxially on either closed-loop or straight lines to form gaps between their ends. The projectile has an electrically conductive gap-portion that passes through all the gaps of all the stages in a direction transverse to the axes of the coils. The coils receive an electric current, store magnetic energy, and convert a significant portion of the stored magnetic energy into kinetic energy of the projectile moves through the gap. The magnetic polarity of the opposing coils is in the same direction, e.g. N-S-N-S. A gap portion of the projectile may be made from aluminum and is propelled by the reconnection of magnetic flux stored in the coils which causes accelerating forces to act upon the projectile and at the horizontal surfaces of the projectile near its rear. The gap portion of the projectile may be flat, rectangular and longer than the length of the opposing coils. The gap portion of the projectile permits substantially unrestricted distribution of the induced currents so that current densities are only high where the useful magnetic force is high. This allows designs which permit ohmic oblation from the rear surfaces of the gap portion of the projectile allowing much high velocities to be achieved. An electric power apparatus controls the electric power supplied to the opposing coils until the gap portion of the projectile substantially occupies the gap between the coils, at which time the coils are supplied with peak current quickly. 8 figs.

  14. Ames Lab 101: Magnetic Refrigeration

    ScienceCinema (OSTI)

    Pecharsky, Vitalij

    2013-03-01

    Vitalij Pecharsky, distinguished professor of materials science and engineering, discusses his research in magnetic refrigeration at Ames Lab.

  15. Ames Lab 101: Magnetic Refrigeration

    SciTech Connect (OSTI)

    Pecharsky, Vitalij

    2011-01-01

    Vitalij Pecharsky, distinguished professor of materials science and engineering, discusses his research in magnetic refrigeration at Ames Lab.

  16. Evolution of twisted magnetic fields

    SciTech Connect (OSTI)

    Zweibel, E.G.; Boozer, A.H.

    1985-02-01

    The magnetic field of the solar corona evolves quasistatically in response to slowly changing photospheric boundary conditions. The magnetic topology is preserved by the low resistivity of the solar atmosphere. We show that a magnetic flux coordinate system simplifies the problem of calculating field evolution with invariant topology. As an example, we calculate the equilibrium of a thin magnetic flux tube with small twist per unit length.

  17. Carbon Joins the Magnetic Club

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

    Press Release 29 May 2007 Carbon Joins the Magnetic Club summary written by Brad Plummer, SLAC Communication Office The exclusive club of magnetic elements officially has a new member-carbon. Using a proton beam and advanced x-ray techniques, SLAC researchers in collaboration with colleagues from LBNL and the University of Leipzig in Germany have finally put to rest doubts about carbon's ability to be made magnetic. "In the past, some groups thought they had discovered magnetic

  18. The Equations of Motion of Compact Binaries in the Neighborhood of Supermassive Black Hole

    SciTech Connect (OSTI)

    Gorbatsievich, Alexander; Bobrik, Alexey

    2010-03-24

    By the use of Einstein-Infeld-Hoffmann method, the equations of motion of a binary star system in the field of a supermassive black hole are derived. In spite of the fact that the motion of a binary system as a whole can be relativistic or even ultra-relativistic with respect to the supermassive black hole, it is shown, that under the assumption of non-relativistic relative motion of the stars in binary system, the motion of the binary system as a whole satisfies the Mathisson-Papapetrou equations with additional terms depending on quadrupole moments. Exemplary case of ultrarelativistic motion of a binary neutron star in the vicinity of non-rotating black hole is considered. It it shown that the motion of binary's center of mass may considerably differ from geodesic motion.

  19. Prostate Bed Motion During Intensity-Modulated Radiotherapy Treatment

    SciTech Connect (OSTI)

    Klayton, Tracy; Price, Robert; Buyyounouski, Mark K.; Sobczak, Mark; Greenberg, Richard; Li, Jinsheng; Keller, Lanea; Sopka, Dennis; Kutikov, Alexander; Horwitz, Eric M.

    2012-09-01

    Purpose: Conformal radiation therapy in the postprostatectomy setting requires accurate setup and localization of the prostatic fossa. In this series, we report prostate bed localization and motion characteristics, using data collected from implanted radiofrequency transponders. Methods and Materials: The Calypso four-dimensional localization system uses three implanted radiofrequency transponders for daily target localization and real-time tracking throughout a course of radiation therapy. We reviewed the localization and tracking reports for 20 patients who received ultrasonography-guided placement of Calypso transponders within the prostate bed prior to a course of intensity-modulated radiation therapy at Fox Chase Cancer Center. Results: At localization, prostate bed displacement relative to bony anatomy exceeded 5 mm in 9% of fractions in the anterior-posterior (A-P) direction and 21% of fractions in the superior-inferior (S-I) direction. The three-dimensional vector length from skin marks to Calypso alignment exceeded 1 cm in 24% of all 652 fractions with available setup data. During treatment, the target exceeded the 5-mm tracking limit for at least 30 sec in 11% of all fractions, generally in the A-P or S-I direction. In the A-P direction, target motion was twice as likely to move posteriorly, toward the rectum, than anteriorly. Fifteen percent of all treatments were interrupted for repositioning, and 70% of patients were repositioned at least once during their treatment course. Conclusion: Set-up errors and motion of the prostatic fossa during radiotherapy are nontrivial, leading to potential undertreatment of target and excess normal tissue toxicity if not taken into account during treatment planning. Localization and real-time tracking of the prostate bed via implanted Calypso transponders can be used to improve the accuracy of plan delivery.

  20. I Historical Information H. 6 SeismicIGround Motion Activity

    Office of Legacy Management (LM)

    Historical Information H. 6 SeismicIGround Motion Activity Book 3 Seismic Data from Rulison DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. This page intentionally left blank S E I S M I C D A T A F R O M R U L I S O N ENVIRONMENTAL SCIENCE SERVICES ADMINISTRATION COAST AND GEODETIC SURVEY Prepared By SPECIAL SEISMOLOGICAL ANALYSIS BRANCH James N. Jordan, Chief Sponsored By U .S. ARMS CONTROL AND

  1. Low-temperature magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1983-05-26

    The invention relates to magnetic refrigeration and more particularly to low temperature refrigeration between about 4 and about 20 K, with an apparatus and method utilizing a belt of magnetic material passed in and out of a magnetic field with heat exchangers within and outside the field operably disposed to accomplish refrigeration.

  2. Low-temperature magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, John A.

    1985-01-01

    The disclosure is directed to a low temperature 4 to 20 K. refrigeration apparatus and method utilizing a ring of magnetic material moving through a magnetic field. Heat exchange is accomplished in and out of the magnetic field to appropriately utilize the device to execute Carnot and Stirling cycles.

  3. Low field magnetic resonance imaging

    DOE Patents [OSTI]

    Pines, Alexander; Sakellariou, Dimitrios; Meriles, Carlos A.; Trabesinger, Andreas H.

    2010-07-13

    A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.

  4. Iterative reconstruction of magnetic induction using Lorentz...

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

    Iterative reconstruction of magnetic induction using Lorentz transmission electron tomography Title Iterative reconstruction of magnetic induction using Lorentz transmission...

  5. NUMERICAL SIMULATIONS OF CHROMOSPHERIC ANEMONE JETS ASSOCIATED WITH MOVING MAGNETIC FEATURES

    SciTech Connect (OSTI)

    Yang, Liping; He, Jiansen; Tu, Chuanyi; Zhang, Lei; Peter, Hardi; Feng, Xueshang; Zhang, Shaohua

    2013-11-01

    Observations with the space-based solar observatory Hinode show that small-scale magnetic structures in the photosphere are found to be associated with a particular class of jets of plasma in the chromosphere called anemone jets. The goal of our study is to conduct a numerical experiment of such chromospheric anemone jets related to the moving magnetic features (MMFs). We construct a 2.5 dimensional numerical MHD model to describe the process of magnetic reconnection between the MMFs and the pre-existing ambient magnetic field, which is driven by the horizontal motion of the magnetic structure in the photosphere. We include thermal conduction parallel to the magnetic field and optically thin radiative losses in the corona to account for a self-consistent description of the evaporation process during the heating of the plasma due to the reconnection process. The motion of the MMFs leads to the expected jet and our numerical results can reproduce many observed characteristics of chromospheric anemone jets, topologically and quantitatively. As a result of the tearing instability, plasmoids are generated in the reconnection process that are consistent with the observed bright moving blobs in the anemone jets. An increase in the thermal pressure at the base of the jet is also driven by the reconnection, which induces a train of slow-mode shocks propagating upward. These shocks are a secondary effect, and only modulate the outflow of the anemone jet. The jet itself is driven by the energy input due to the reconnection of the MMFs and the ambient magnetic field.

  6. Core and filament formation in magnetized, self-gravitating isothermal layers

    SciTech Connect (OSTI)

    Van Loo, Sven; Keto, Eric; Zhang, Qizhou

    2014-07-01

    We examine the role of the gravitational instability in an isothermal, self-gravitating layer threaded by magnetic fields on the formation of filaments and dense cores. Using a numerical simulation, we follow the non-linear evolution of a perturbed equilibrium layer. The linear evolution of such a layer is described in the analytic work of Nagai et al. We find that filaments and dense cores form simultaneously. Depending on the initial magnetic field, the resulting filaments form either a spiderweb-like network (for weak magnetic fields) or a network of parallel filaments aligned perpendicular to the magnetic field lines (for strong magnetic fields). Although the filaments are radially collapsing, the density profile of their central region (up to the thermal scale height) can be approximated by a hydrodynamical equilibrium density structure. Thus, the magnetic field does not play a significant role in setting the density distribution of the filaments. The density distribution outside of the central region deviates from the equilibrium. The radial column density distribution is then flatter than the expected power law of r {sup 4} and similar to filament profiles observed with Herschel. Our results do not explain the near constant filament width of ?0.1pc. However, our model does not include turbulent motions. It is expected that the accretion-driven amplification of these turbulent motions provides additional support within the filaments against gravitational collapse. Finally, we interpret the filamentary network of the massive star forming complex G14.225-0.506 in terms of the gravitational instability model and find that the properties of the complex are consistent with being formed out of an unstable layer threaded by a strong, parallel magnetic field.

  7. Spatiotemporal filtering of MR-temperature artifacts arising from bowel motion during transurethral MR-HIFU

    SciTech Connect (OSTI)

    Schmitt, Alain; Mougenot, Charles; Chopra, Rajiv

    2014-11-01

    Purpose: Transurethral MR-HIFU is a minimally invasive image-guided treatment for localized prostate cancer that enables precise targeting of tissue within the gland. The treatment is performed within a clinical MRI to obtain real-time MR thermometry used as an active feedback to control the spatial heating pattern in the prostate and to monitor for potential damage to surrounding tissues. This requires that the MR thermometry measurements are an accurate representation of the true tissue temperature. The proton resonance frequency shift thermometry method used is sensitive to tissue motion and changes in the local magnetic susceptibility that can be caused by the motion of air bubbles in the rectum, which can impact the performance of transurethral MR-HIFU in these regions of the gland. Methods: A method is proposed for filtering of temperature artifacts based on the temporal variance of the temperature, using empirical and dynamic positional knowledge of the ultrasonic heating beam, and an estimation of the measurement noise. A two-step correction strategy is introduced which eliminates artifact-detected temperature variations while keeping the noise level low through spatial averaging. Results: The filter has been evaluated by postprocessing data from five human transurethral ultrasound treatments. The two-step correction process led to reduced final temperature standard deviation in the prostate and rectum areas where the artifact was located, without negatively affecting areas distal to the artifact. The performance of the filter was also found to be consistent across all six of the data sets evaluated. The evaluation of the detection criterion parameter M determined that a value of M = 3 achieves a conservative filter with minimal loss of spatial resolution during the process. Conclusions: The filter was able to remove most artifacts due to the presence of moving air bubbles in the rectum during transurethral MR-HIFU. A quantitative estimation of the filter capabilities shows a systematic improvement in the standard deviation of the corrected temperature maps in the rectum zone as well as in the entire acquired slice.

  8. Method of making permanent magnets

    DOE Patents [OSTI]

    McCallum, R.W.; Dennis, K.W.; Lograsso, B.K.; Anderson, I.E.

    1993-09-07

    A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles. Wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties. 13 figures.

  9. Method of making permanent magnets

    DOE Patents [OSTI]

    McCallum, R. William; Dennis, Kevin W.; Lograsso, Barbara K.; Anderson, Iver E.

    1993-09-07

    A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties.

  10. 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 element. Now, another use has been found: magnets. One would not expect pure carbon to be magnetic, but for more than ten years scientists have suspected that carbon can be made to be magnetic by doping it with nonmagnetic materials, changing its order ever so slightly. Years ago, the first x-ray images obtained using the

  11. Connecting apparatus for limited rotary of rectilinear motion (II)

    DOE Patents [OSTI]

    Hardin, Jr., Roy T.; Kurinko, Carl D.

    1981-01-01

    Apparatus for providing connection between two members having relative movement in a horizontal plane in a rotary or linear fashion. The apparatus includes a set of vertical surfaces affixed to each of the members, laterally aligned across a selected vertical gap. A number of cables or hoses, for electrical, hydraulic, or pneumatic connection are arranged between consecutive surfaces in a C-shaped traveling loop, connected through their end portions to the two respective members, so that through a sliding motion portions of the cable are transferred from between one set of surfaces to the other aligned set, across the gap, upon relative motion of the members. A number of flexible devices are affixed to the upper set of surfaces for supporting the upper portion of each looped cable. The apparatus is particularly adaptable to an area having limited lateral clearances and requiring signal level separation between electrical cables, such as found in the rotating plugs and associated equipment of the reactor vessel head of a nuclear reactor.

  12. Well-observed dynamics of flaring and peripheral coronal magnetic loops during an M-class limb flare

    SciTech Connect (OSTI)

    Shen, Jinhua; Zhou, Tuanhui; Ji, Haisheng; Feng, Li; Wiegelmann, Thomas; Inhester, Bernd

    2014-08-20

    In this paper, we present a variety of well-observed dynamic behaviors for the flaring and peripheral magnetic loops of the M6.6 class extreme limb flare that occurred on 2011 February 24 (SOL2011-02-24T07:20) from EUV observations by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory and X-ray observations by RHESSI. The flaring loop motion confirms the earlier contraction-expansion picture. We find that the U-shaped trajectory delineated by the X-ray corona source of the flare roughly follows the direction of a filament eruption associated with the flare. Different temperature structures of the coronal source during the contraction and expansion phases strongly suggest different kinds of magnetic reconnection processes. For some peripheral loops, we discover that their dynamics are closely correlated with the filament eruption. During the slow rising to abrupt, fast rising of the filament, overlying peripheral magnetic loops display different responses. Two magnetic loops on the elbow of the active region had a slow descending motion followed by an abrupt successive fast contraction, while magnetic loops on the top of the filament were pushed outward, slowly being inflated for a while and then erupting as a moving front. We show that the filament activation and eruption play a dominant role in determining the dynamics of the overlying peripheral coronal magnetic loops.

  13. Inductrack magnet configuration

    DOE Patents [OSTI]

    Post, Richard Freeman

    2003-10-14

    A magnet configuration comprising a pair of Halbach arrays magnetically and structurally connected together are positioned with respect to each other so that a first component of their fields substantially cancels at a first plane between them, and a second component of their fields substantially adds at this first plane. A track of windings is located between the pair of Halbach arrays and a propulsion mechanism is provided for moving the pair of Halbach arrays along the track. When the pair of Halbach arrays move along the track and the track is not located at the first plane, a current is induced in the windings and a restoring force is exerted on the pair of Halbach arrays.

  14. Inductrack magnet configuration

    DOE Patents [OSTI]

    Post, Richard Freeman

    2003-12-16

    A magnet configuration comprising a pair of Halbach arrays magnetically and structurally connected together are positioned with respect to each other so that a first component of their fields substantially cancels at a first plane between them, and a second component of their fields substantially adds at this first plane. A track of windings is located between the pair of Halbach arrays and a propulsion mechanism is provided for moving the pair of Halbach arrays along the track. When the pair of Halbach arrays move along the track and the track is not located at the first plane, a current is induced in the windings and a restoring force is exerted on the pair of Halbach arrays.

  15. Magnetized Turbulent Dynamo in Protogalaxies

    SciTech Connect (OSTI)

    Leonid Malyshkin; Russell M. Kulsrud

    2002-01-28

    The prevailing theory for the origin of cosmic magnetic fields is that they have been amplified to their present values by the turbulent dynamo inductive action in the protogalactic and galactic medium. Up to now, in calculation of the turbulent dynamo, it has been customary to assume that there is no back reaction of the magnetic field on the turbulence, as long as the magnetic energy is less than the turbulent kinetic energy. This assumption leads to the kinematic dynamo theory. However, the applicability of this theory to protogalaxies is rather limited. The reason is that in protogalaxies the temperature is very high, and the viscosity is dominated by magnetized ions. As the magnetic field strength grows in time, the ion cyclotron time becomes shorter than the ion collision time, and the plasma becomes strongly magnetized. As a result, the ion viscosity becomes the Braginskii viscosity. Thus, in protogalaxies the back reaction sets in much earlier, at field strengths much lower than those which correspond to field-turbulence energy equipartition, and the turbulent dynamo becomes what we call the magnetized turbulent dynamo. In this paper we lay the theoretical groundwork for the magnetized turbulent dynamo. In particular, we predict that the magnetic energy growth rate in the magnetized dynamo theory is up to ten times larger than that in the kinematic dynamo theory. We also briefly discuss how the Braginskii viscosity can aid the development of the inverse cascade of magnetic energy after the energy equipartition is reached.

  16. Magnetic hydrogel with high coercivity

    SciTech Connect (OSTI)

    Szeri, H.; Alvero?lu, E.; Kurtan, U.; ?enel, M.; Baykal, A.

    2013-08-01

    Highlights: Polyacrylamide (PAAm) hydrogels containing magnetic BaFe{sub 12}O{sub 19} nanoparticles have been prepared. Magnetization measurements reveal that hydrogels have hard magnetic properties with high coercivity. Magnetic nanoparticles makes the gel more homogeneous and do not diffuse out of the gel during water intake. These gels are useful in applications as wastewater treatment once gels are magnetized before its usage. - Abstract: This study investigates the synthesis and characterization of polyacrylamide (PAAm) hydrogels containing magnetic BaFe{sub 12}O{sub 19} nanoparticles. Structural, electrical, and magnetic characterization of the gels have been performed with X-ray powder diffractometry, scanning electron microscopy, DC conductivity, magnetization and fluorescence spectroscopy techniques. The preparation and characterization of polyacrylamide (PAAm) hydrogels that contain 5 and 10 mg BaFe{sub 12}O{sub 19} (16 and 21 nm diameter) nanoparticles are described herein. It is seen from the fluorescence spectra that, nanoparticles surrounded to pyranine molecules so that some of pyranine molecules could not bound to the polymer strands. Electrical measurements show that presence of nanoparticles make the gel more homogeneous. Magnetization measurements reveal that hydrogels have hard magnetic properties with quite high coercivity of 4.2 kOe, which does not change with swelling. This feature makes these gels useful in applications as wastewater treatment if they are magnetized before use.

  17. Magnetic resonance apparatus

    DOE Patents [OSTI]

    Jackson, J.A.; Cooper, R.K.

    1980-10-10

    The patent consists of means for producing a region of homogeneous magnetic field remote from the source of the field, wherein two equal field sources are arranged axially so their fields oppose, producing a region near the plane perpendicular to the axis midway between the sources where the radial correspondent of the field goes through a maximum. Near the maximum, the field is homogeneous over prescribed regions.

  18. EVOLUTION OF A MAGNETIC FLUX ROPE AND ITS OVERLYING ARCADE BASED ON NONLINEAR FORCE-FREE FIELD EXTRAPOLATIONS

    SciTech Connect (OSTI)

    Jing, Ju; Liu, Chang; Lee, Jeongwoo; Wang, Shuo; Xu, Yan; Wang, Haimin; Wiegelmann, Thomas

    2014-03-20

    Dynamic phenomena indicative of slipping reconnection and magnetic implosion were found in a time series of nonlinear force-free field (NLFFF) extrapolations for the active region 11515, which underwent significant changes in the photospheric fields and produced five C-class flares and one M-class flare over five hours on 2012 July 2. NLFFF extrapolation was performed for the uninterrupted 5 hour period from the 12 minute cadence vector magnetograms of the Helioseismic and Magnetic Imager on board the Solar Dynamic Observatory. According to the time-dependent NLFFF model, there was an elongated, highly sheared magnetic flux rope structure that aligns well with an Hα filament. This long filament splits sideways into two shorter segments, which further separate from each other over time at a speed of 1-4 km s{sup –1}, much faster than that of the footpoint motion of the magnetic field. During the separation, the magnetic arcade arching over the initial flux rope significantly decreases in height from ∼4.5 Mm to less than 0.5 Mm. We discuss the reality of this modeled magnetic restructuring by relating it to the observations of the magnetic cancellation, flares, a filament eruption, a penumbra formation, and magnetic flows around the magnetic polarity inversion line.

  19. IGRT/ART phantom with programmable independent rib cage and tumor motion

    SciTech Connect (OSTI)

    Haas, Olivier C. L.; Mills, John A.; Land, Imke; Mulholl, Pete; Menary, Paul; Crichton, Robert; Wilson, Adrian; Sage, John; Anna, Morenc; Depuydt, Tom

    2014-02-15

    Purpose: This paper describes the design and experimental evaluation of the Methods and Advanced Equipment for Simulation and Treatment in Radiation Oncology (MAESTRO) thorax phantom, a new anthropomorphic moving ribcage combined with a 3D tumor positioning system to move target inserts within static lungs. Methods: The new rib cage design is described and its motion is evaluated using Vicon Nexus, a commercial 3D motion tracking system. CT studies at inhale and exhale position are used to study the effect of rib motion and tissue equivalence. Results: The 3D target positioning system and the rib cage have millimetre accuracy. Each axis of motion can reproduce given trajectories from files or individually programmed sinusoidal motion in terms of amplitude, period, and phase shift. The maximum rib motion ranges from 7 to 20 mm SI and from 0.3 to 3.7 mm AP with LR motion less than 1 mm. The repeatability between cycles is within 0.16 mm root mean square error. The agreement between CT electron and mass density for skin, ribcage, spine hard and inner bone as well as cartilage is within 3%. Conclusions: The MAESTRO phantom is a useful research tool that produces programmable 3D rib motions which can be synchronized with 3D internal target motion. The easily accessible static lungs enable the use of a wide range of inserts or can be filled with lung tissue equivalent and deformed using the target motion system.

  20. Penetration depth and absorption mechanisms of spin currents in Ir{sub 20}Mn{sub 80} and Fe{sub 50}Mn{sub 50} polycrystalline films by ferromagnetic resonance and spin pumping

    SciTech Connect (OSTI)

    Merodio, P.; Ghosh, A.; Lemonias, C.; Gautier, E.; Ebels, U.; Chshiev, M.; Béa, H. E-mail: helene.bea@cea.fr; Baltz, V. E-mail: helene.bea@cea.fr

    2014-01-20

    Spintronics relies on the spin dependent transport properties of ferromagnets (Fs). Although antiferromagnets (AFs) are used for their magnetic properties only, some fundamental F-spintronics phenomena like spin transfer torque, domain wall motion, and tunnel anisotropic magnetoresistance also occur with AFs, thus making AF-spintronics attractive. Here, room temperature critical depths and absorption mechanisms of spin currents in Ir{sub 20}Mn{sub 80} and Fe{sub 50}Mn{sub 50} are determined by F-resonance and spin pumping. In particular, we find room temperature critical depths originating from different absorption mechanisms: dephasing for Ir{sub 20}Mn{sub 80} and spin flipping for Fe{sub 50}Mn{sub 50}.

  1. Nonthermally dominated electron acceleration during magnetic reconnection in a low-β plasma

    SciTech Connect (OSTI)

    Li, Xiaocan; Guo, Fan; Li, Hui; Li, Gang

    2015-09-24

    By means of fully kinetic simulations, we investigate electron acceleration during magnetic reconnection in a nonrelativistic proton–electron plasma with conditions similar to solar corona and flares. We demonstrate that reconnection leads to a nonthermally dominated electron acceleration with a power-law energy distribution in the nonrelativistic low-β regime but not in the high-β regime, where β is the ratio of the plasma thermal pressure and the magnetic pressure. The accelerated electrons contain most of the dissipated magnetic energy in the low-β regime. A guiding-center current description is used to reveal the role of electron drift motions during the bulk nonthermal energization. We find that the main acceleration mechanism is a Fermi-type acceleration accomplished by the particle curvature drift motion along the electric field induced by the reconnection outflows. Although the acceleration mechanism is similar for different plasma β, low-β reconnection drives fast acceleration on Alfvénic timescales and develops power laws out of thermal distribution. Thus, the nonthermally dominated acceleration resulting from magnetic reconnection in low-β plasma may have strong implications for the highly efficient electron acceleration in solar flares and other astrophysical systems.

  2. Nonthermally dominated electron acceleration during magnetic reconnection in a low-β plasma

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

    Li, Xiaocan; Guo, Fan; Li, Hui; Li, Gang

    2015-09-24

    By means of fully kinetic simulations, we investigate electron acceleration during magnetic reconnection in a nonrelativistic proton–electron plasma with conditions similar to solar corona and flares. We demonstrate that reconnection leads to a nonthermally dominated electron acceleration with a power-law energy distribution in the nonrelativistic low-β regime but not in the high-β regime, where β is the ratio of the plasma thermal pressure and the magnetic pressure. The accelerated electrons contain most of the dissipated magnetic energy in the low-β regime. A guiding-center current description is used to reveal the role of electron drift motions during the bulk nonthermal energization.more » We find that the main acceleration mechanism is a Fermi-type acceleration accomplished by the particle curvature drift motion along the electric field induced by the reconnection outflows. Although the acceleration mechanism is similar for different plasma β, low-β reconnection drives fast acceleration on Alfvénic timescales and develops power laws out of thermal distribution. Thus, the nonthermally dominated acceleration resulting from magnetic reconnection in low-β plasma may have strong implications for the highly efficient electron acceleration in solar flares and other astrophysical systems.« less

  3. SYSTEMATIC MOTION OF FINE-SCALE JETS AND SUCCESSIVE RECONNECTION IN SOLAR CHROMOSPHERIC ANEMONE JET OBSERVED WITH THE SOLAR OPTICAL TELESCOPE/HINODE

    SciTech Connect (OSTI)

    Singh, K. A. P.; Nishida, K.; Shibata, K.; Isobe, H.

    2012-11-20

    The Solar Optical Telescope (SOT) on board Hinode allows observations with high spatiotemporal resolution and stable image quality. A {lambda}-shaped chromospheric anemone jet was observed in high resolution with SOT/Hinode. We found that several fine-scale jets were launched from one end of the footpoint to the other. These fine-scale jets ({approx}1.5-2.5 Mm) gradually move from one end of the footpoint to the other and finally merge into a single jet. This process occurs recurrently, and as time progresses the jet activity becomes more and more violent. The time evolution of the region below the jet in Ca II H filtergram images taken with SOT shows that various parts (or knots) appear at different positions. These bright knots gradually merge into each other during the maximum phase. The systematic motion of the fine-scale jets is observed when different knots merge into each other. Such morphology would arise due to the emergence of a three-dimensional twisted flux rope in which the axial component (or the guide field) appears in the later stages of the flux rope emergence. The partial appearance of the knots could be due to the azimuthal magnetic field that appears during the early stage of the flux rope emergence. If the guide field is strong and reconnection occurs between the emerging flux rope and an ambient magnetic field, this could explain the typical feature of systematic motion in chromospheric anemone jets.

  4. Selectivity in multiple quantum nuclear magnetic resonance

    SciTech Connect (OSTI)

    Warren, W.S.

    1980-11-01

    The observation of multiple-quantum nuclear magnetic resonance transitions in isotropic or anisotropic liquids is shown to give readily interpretable information on molecular configurations, rates of motional processes, and intramolecular interactions. However, the observed intensity of high multiple-quantum transitions falls off dramatically as the number of coupled spins increases. The theory of multiple-quantum NMR is developed through the density matrix formalism, and exact intensities are derived for several cases (isotropic first-order systems and anisotropic systems with high symmetry) to shown that this intensity decrease is expected if standard multiple-quantum pulse sequences are used. New pulse sequences are developed which excite coherences and produce population inversions only between selected states, even though other transitions are simultaneously resonant. One type of selective excitation presented only allows molecules to absorb and emit photons in groups of n. Coherent averaging theory is extended to describe these selective sequences, and to design sequences which are selective to arbitrarily high order in the Magnus expansion. This theory and computer calculations both show that extremely good selectivity and large signal enhancements are possible.

  5. Global-scale consequences of magnetic-helicity injection and condensation on the sun

    SciTech Connect (OSTI)

    Mackay, Duncan H.; DeVore, C. Richard; Antiochos, Spiro K.

    2014-04-01

    In the recent paper of Antiochos, a new concept for the injection of magnetic helicity into the solar corona by small-scale convective motions and its condensation onto polarity inversion lines (PILs) was developed. We investigate this concept through global simulations of the Sun's photospheric and coronal magnetic fields, and compare the results with the hemispheric pattern of solar filaments. Assuming that the vorticity of the cells is predominantly counterclockwise/clockwise in the northern/southern hemisphere, the convective motions inject negative/positive helicity into each hemisphere. The simulations show that: (1) on a north-south oriented PIL, both differential rotation and convective motions inject the same sign of helicity, which matches that required to reproduce the hemispheric pattern of filaments. (2) On a high-latitude east-west oriented polar crown or subpolar crown PIL, the vorticity of the cells has to be approximately 2-3 times greater than the local differential-rotation gradient in order to overcome the incorrect sign of helicity injection from differential rotation. (3) In the declining phase of the cycle, as a bipole interacts with the polar field, in some cases, helicity condensation can reverse the effect of differential rotation along the east-west lead arm but not in all cases. The results show that this newly developed concept of magnetic helicity injection and condensation, in conjunction with the mechanisms used in Yeates et al., is a viable explanation for the hemispheric pattern of filaments. Future observational studies should focus on examining the vorticity component within convective motions to determine both its magnitude and latitudinal variation relative to the differential-rotation gradient on the Sun.

  6. Electronic Structure and Magnetism in Diluted Magnetic Semiconductors

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

    Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted magnetic semiconductors created by doping ions like Mn, Fe, or Co having a net spin into a semiconducting host

  7. Electronic Structure and Magnetism in Diluted Magnetic Semiconductors

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

    Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted magnetic semiconductors created by doping ions like Mn, Fe, or Co having a net spin into a semiconducting host

  8. Electronic Structure and Magnetism in Diluted Magnetic Semiconductors

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

    Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted magnetic semiconductors created by doping ions like Mn, Fe, or Co having a net spin into a semiconducting host

  9. Electronic Structure and Magnetism in Diluted Magnetic Semiconductors

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

    Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted magnetic semiconductors created by doping ions like Mn, Fe, or Co having a net spin into a semiconducting host

  10. Electronic Structure and Magnetism in Diluted Magnetic Semiconductors

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

    Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print The possibility of using electrons' spins in addition to their charge in information technology has created much enthusiasm for a new field of electronics popularly known as "spintronics." An intensely studied approach to obtaining spin-polarized carriers for data-storage devices is the use of diluted magnetic semiconductors created by doping ions like Mn, Fe, or Co having a net spin into a semiconducting host

  11. Phase and Radial Motion in Ion Linear Accelerators

    Energy Science and Technology Software Center (OSTI)

    2007-03-29

    Parmila is an ion-linac particle-dynamics code. The name comes from the phrase, "Phase and Radial Motion in Ion Linear Accelerators." The code generates DTL, CCDTL, and CCL accelerating cells and, using a "drift-kick" method, transforms the beam, represented by a collection of particles, through the linac. The code includes a 2-D and 3-D space-charge calculations. Parmila uses data generated by the Poisson Superfish postprocessor SEC. This version of Parmila was written by Harunori Takeda andmore » was supported through Feb. 2006 by James H. Billen. Setup installs executable programs Parmila.EXE, Lingraf.EXE, and ReadPMI.EXE in the LANL directory. The directory LANL\\Examples\\Parmila contains several subdirectories with sample files for Parmila.« less

  12. Historical Information H.6 SeismicIGround Motion Activity

    Office of Legacy Management (LM)

    , SeismicIGround Motion Activity Book 3 Structural Response Studies for Project Rulison DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. S t r u c t u r a l Response Studies f o r P r o j e c t R U L I S O N P r e p a r e d under C o n t r a c t ATC26-13-99 f o r t h e Nevada Operations O f f i c e , USAEC J o h n A. B l u m e & A s s o c i a t e s R e s e a r c h D i v i s i o n san f r a n c

  13. Damping, motional narrowing, and chaos in rotational nuclei

    SciTech Connect (OSTI)

    Stephens, F. S.; Deleplanque, M. A.; Lee, I. Y.; Macchiavelli, A. O.; Fallon, P.; Diamond, R. M.; Ward, D.; Clark, R. M.; Cromaz, M.

    2008-09-15

    We have studied the unresolved {gamma}-ray spectrum of three ytterbium nuclei produced in heavy-ion fusion reactions and measured the two damping widths, {gamma}{sub {mu}}, the spreading (compound-damping) width, and {gamma}{sub rot}, the rotational damping width, together with P{sub nar}, the probability that the population enters and leaves a given state via the same component of the wave function. Our results for {gamma}{sub {mu}} and {gamma}{sub rot} are in good agreement with theoretical expectations, as well as with those of other groups using different methods. Our results for P{sub nar} lead to a new method for quantitative evaluation of the full order-to-chaos transition in these Yb nuclei. Finally, we provide the first evidence for the motional narrowing of {gamma}{sub rot} in nuclei. The basic physics occurring in this region is level mixing, which our simulation technique reproduces surprisingly well.

  14. Photothermally activated motion and ignition using aluminum nanoparticles

    SciTech Connect (OSTI)

    Abboud, Jacques E.; Chong Xinyuan; Zhang Mingjun; Zhang Zhili; Jiang Naibo; Roy, Sukesh; Gord, James R.

    2013-01-14

    The aluminum nanoparticles (Al NPs) are demonstrated to serve as active photothermal media, to enhance and control local photothermal energy deposition via the photothermal effect activated by localized surface plasmon resonance (LSPR) and amplified by Al NPs oxidation. The activation source is a 2-AA-battery-powered xenon flash lamp. The extent of the photothermally activated movement of Al NPs can be {approx}6 mm. Ignition delay can be {approx}0.1 ms. Both scanning electron microscopy and energy-dispersive X-ray spectroscopy measurements of motion-only and after-ignition products confirm significant Al oxidation occurs through sintering and bursting after the flash exposure. Simulations suggest local heat generation is enhanced by LSPR. The positive-feedback effects from the local heat generation amplified by Al oxidation produce a large increase in local temperature and pressure, which enhances movement and accelerates ignition.

  15. Full-wave receiver architecture for the homodyne motion sensor

    DOE Patents [OSTI]

    Haugen, Peter C; Dallum, Gregory E; Welsh, Patrick A; Romero, Carlos E

    2013-11-19

    A homodyne motion sensor or detector based on ultra-wideband radar utilizes the entire received waveform through implementation of a voltage boosting receiver. The receiver includes a receiver input and a receiver output. A first diode is connected to the receiver output. A first charge storage capacitor is connected from between the first diode and the receiver output to ground. A second charge storage capacitor is connected between the receiver input and the first diode. A second diode is connected from between the second charge storage capacitor and the first diode to ground. The dual diode receiver performs voltage boosting of a RF signal received at the receiver input, thereby enhancing receiver sensitivity.

  16. Full-wave receiver architecture for the homodyne motion sensor

    DOE Patents [OSTI]

    Haugen, Peter C.; Dallum, Gregory E.; Welsh, Patrick A.; Romero, Carlos E.

    2015-09-29

    A homodyne motion sensor or detector based on ultra-wideband radar utilizes the entire received waveform through implementation of a voltage boosting receiver. The receiver includes a receiver input and a receiver output. A first diode is connected to the receiver output. A first charge storage capacitor is connected from between the first diode and the receiver output to ground. A second charge storage capacitor is connected between the receiver input and the first diode. A second diode is connected from between the second charge storage capacitor and the first diode to ground. The dual diode receiver performs voltage boosting of a RF signal received at the receiver input, thereby enhancing receiver sensitivity.

  17. Real time markerless motion tracking using linked kinematic chains

    DOE Patents [OSTI]

    Luck, Jason P.; Small, Daniel E.

    2007-08-14

    A markerless method is described for tracking the motion of subjects in a three dimensional environment using a model based on linked kinematic chains. The invention is suitable for tracking robotic, animal or human subjects in real-time using a single computer with inexpensive video equipment, and does not require the use of markers or specialized clothing. A simple model of rigid linked segments is constructed of the subject and tracked using three dimensional volumetric data collected by a multiple camera video imaging system. A physics based method is then used to compute forces to align the model with subsequent volumetric data sets in real-time. The method is able to handle occlusion of segments and accommodates joint limits, velocity constraints, and collision constraints and provides for error recovery. The method further provides for elimination of singularities in Jacobian based calculations, which has been problematic in alternative methods.

  18. Intrinsic feature-based pose measurement for imaging motion compensation

    DOE Patents [OSTI]

    Baba, Justin S.; Goddard, Jr., James Samuel

    2014-08-19

    Systems and methods for generating motion corrected tomographic images are provided. A method includes obtaining first images of a region of interest (ROI) to be imaged and associated with a first time, where the first images are associated with different positions and orientations with respect to the ROI. The method also includes defining an active region in the each of the first images and selecting intrinsic features in each of the first images based on the active region. Second, identifying a portion of the intrinsic features temporally and spatially matching intrinsic features in corresponding ones of second images of the ROI associated with a second time prior to the first time and computing three-dimensional (3D) coordinates for the portion of the intrinsic features. Finally, the method includes computing a relative pose for the first images based on the 3D coordinates.

  19. Joint Motion to Intervene of Northern States Power Company (Minnesota) et

    Energy Savers [EERE]

    al. on the Proposed Open Access Requirements | Department of Energy Motion to Intervene of Northern States Power Company (Minnesota) et al. on the Proposed Open Access Requirements Joint Motion to Intervene of Northern States Power Company (Minnesota) et al. on the Proposed Open Access Requirements Joint motion to intervene of the Northern States Power Company (Minnesota), the Northern States Power Company (Wisconsin), and NRG Energy, Incl on the Proposed Open Access Requirements for

  20. Cover Letter for Motion to Intervene and Comments of the District of

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

    Columbia Government | Department of Energy Cover Letter for Motion to Intervene and Comments of the District of Columbia Government Cover Letter for Motion to Intervene and Comments of the District of Columbia Government Docket No. EO-05-01: Cover letter for Motion to Intervene and Comments of the District of Columbia Government, being filed today with the Federal Energy Regulatory Commission, and served upon all parties designated on the official service list, in Docket No. EL05-145-000

  1. Strain-assisted current-induced magnetization reversal in magnetic...

    Office of Scientific and Technical Information (OSTI)

    It is found that the critical current density for in-plane magnetization reversal ... ; Department of Physics, University of Science and Technology Beijing, Beijing 100083 ...

  2. HOW TO DETERMINE AN EXOMOON'S SENSE OF ORBITAL MOTION

    SciTech Connect (OSTI)

    Heller, Ren; Albrecht, Simon E-mail: albrecht@phys.au.dk

    2014-11-20

    We present two methods to determine an exomoon's sense of orbital motion (SOM), one with respect to the planet's circumstellar orbit and one with respect to the planetary rotation. Our simulations show that the required measurements will be possible with the European Extremely Large Telescope (E-ELT). The first method relies on mutual planet-moon events during stellar transits. Eclipses with the moon passing behind (in front of) the planet will be late (early) with regard to the moon's mean orbital period due to the finite speed of light. This ''transit timing dichotomy'' (TTD) determines an exomoon's SOM with respect to the circumstellar motion. For the 10 largest moons in the solar system, TTDs range between 2 and 12 s. The E-ELT will enable such measurements for Earth-sized moons around nearby Sun-like stars. The second method measures distortions in the IR spectrum of the rotating giant planet when it is transited by its moon. This Rossiter-McLaughlin effect (RME) in the planetary spectrum reveals the angle between the planetary equator and the moon's circumplanetary orbital plane, and therefore unveils the moon's SOM with respect to the planet's rotation. A reasonably large moon transiting a directly imaged planet like ?Picb causes an RME amplitude of almost 100 m s{sup 1}, about twice the stellar RME amplitude of the transiting exoplanet HD209458b. Both new methods can be used to probe the origin of exomoons, that is, whether they are regular or irregular in nature.

  3. Control system for an interior permanent magnet synchronous machine

    SciTech Connect (OSTI)

    Bose, B.K.

    1988-10-12

    A high performance, fully operational, four-quadrant control scheme is used in an interior permanent magnet synchronous machine. The machine operates smoothly with full performance in the constant-torque region as well as in the flux-weakening, constant-power region in both directions of motion. The transition between the constant-torque and constant-power regions is very smooth under all conditions of operation. Control in the constant-torque region is based on a vector or field-oriented technique, with the direct-axis aligned with the total stator flux, whereas constant-power region control is accomplished by orientation of the torque angle of the impressed square-wave voltage through the feedforward vector rotator. In a preferred embodiment, the control system employs a digital distributed microcomputer controller arrangement which relies upon various precisely estimated feedback signals, such as torque, flux, etc. The control scheme includes an outer torque control loop primarily for traction type applications, but also contemplates speed and position control loops for various industrial drives. A 70 hp drive system using a Neodymium-Iron-Boron permanent magnet machine and transistor pulse width modulating inverter has been designed and successfully tested. This control scheme also has application in controlling surface permanent magnet machines. 16 figs.

  4. Apparatus and method for continuous separation of magnetic particles from non-magnetic fluids

    DOE Patents [OSTI]

    Oder, Robin R.; Jamison, Russell E.

    2011-11-08

    An apparatus and method for continuous separation of magnetic particles from non-magnetic fluids including particular rods, magnetic fields and flow arrangements.

  5. TURBULENT DIFFUSION IN THE PHOTOSPHERE AS DERIVED FROM PHOTOSPHERIC BRIGHT POINT MOTION

    SciTech Connect (OSTI)

    Abramenko, V. I.; Yurchyshyn, V.; Goode, P. R.; Carbone, V.; Lepreti, F.; Capparelli, V.; Vecchio, A.; Stein, R. F.

    2011-12-20

    On the basis of observations of solar granulation obtained with the New Solar Telescope of Big Bear Solar Observatory, we explored proper motion of bright points (BPs) in a quiet-sun area, a coronal hole, and an active region plage. We automatically detected and traced BPs and derived their mean-squared displacements as a function of time (starting from the appearance of each BP) for all available time intervals. In all three magnetic environments, we found the presence of a super-diffusion regime, which is the most pronounced inside the time interval of 10-300 s. Super-diffusion, measured via the spectral index, {gamma}, which is the slope of the mean-squared displacement spectrum, increases from the plage area ({gamma} = 1.48) to the quiet-sun area ({gamma} = 1.53) to the coronal hole ({gamma} = 1.67). We also found that the coefficient of turbulent diffusion changes in direct proportion to both temporal and spatial scales. For the minimum spatial scale (22 km) and minimum time scale (10 s), it is 22 and 19 km{sup 2} s{sup -1} for the coronal hole and the quiet-sun area, respectively, whereas for the plage area it is about 12 km{sup 2} s{sup -1} for the minimum time scale of 15 s. We applied our BP tracking code to three-dimensional MHD model data of solar convection and found the super-diffusion with {gamma} = 1.45. An expression for the turbulent diffusion coefficient as a function of scales and {gamma} is obtained.

  6. An Updated Central and Eastern United States Ground-Motion Model |

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

    Department of Energy An Updated Central and Eastern United States Ground-Motion Model An Updated Central and Eastern United States Ground-Motion Model An Updated Central and Eastern United States Ground-Motion Model Lawrence Salomone Pinnacle Specialty Group, Inc. DOE NPH Meeting October 21-22, 2014 PDF icon An Updated Central and Eastern United States Ground-Motion Model More Documents & Publications A Probabilistic Seismic Hazard Analysis Update Review for Two DOE Sites and NGA-East

  7. Continuous magnetic separator and process

    DOE Patents [OSTI]

    Oder, Robin R.; Jamison, Russell E.

    2008-04-22

    A continuous magnetic separator and process for separating a slurry comprising magnetic particles into a clarified stream and a thickened stream. The separator has a container with a slurry inlet, an overflow outlet for the discharge of the clarified slurry stream, and an underflow outlet for the discharge of a thickened slurry stream. Magnetic particles in the slurry are attracted to, and slide down, magnetic rods within the container. The slurry is thus separated into magnetic concentrate and clarified slurry. Flow control means can be used to control the ratio of the rate of magnetic concentrate to the rate of clarified slurry. Feed control means can be used to control the rate of slurry feed to the slurry inlet.

  8. Thin film superconductor magnetic bearings

    DOE Patents [OSTI]

    Weinberger, Bernard R.

    1995-12-26

    A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.

  9. Confined partial filament eruption and its reformation within a stable magnetic flux rope

    SciTech Connect (OSTI)

    Joshi, Navin Chandra; Kayshap, Pradeep; Uddin, Wahab; Srivastava, Abhishek K.; Dwivedi, B. N.; Filippov, Boris; Chandra, Ramesh; Choudhary, Debi Prasad E-mail: njoshi98@gmail.com

    2014-05-20

    We present observations of a confined partial eruption of a filament on 2012 August 4, which restores its initial shape within ?2 hr after eruption. From the Global Oscillation Network Group H? observations, we find that the filament plasma turns into dynamic motion at around 11:20 UT from the middle part of the filament toward the northwest direction with an average speed of ?105 km s{sup 1}. A little brightening underneath the filament possibly shows the signature of low-altitude reconnection below the filament eruptive part. In Solar Dynamics Observatory/Atmospheric Imaging Assembly 171 images, we observe an activation of right-handed helically twisted magnetic flux rope that contains the filament material and confines it during its dynamical motion. The motion of cool filament plasma stops after traveling a distance of ?215 Mm toward the northwest from the point of eruption. The plasma moves partly toward the right foot point of the flux rope, while most of the plasma returns after 12:20 UT toward the left foot point with an average speed of ?60 km s{sup 1} to reform the filament within the same stable magnetic structure. On the basis of the filament internal fine structure and its position relative to the photospheric magnetic fields, we find filament chirality to be sinistral, while the activated enveloping flux rope shows a clear right-handed twist. Thus, this dynamic event is an apparent example of one-to-one correspondence between the filament chirality (sinistral) and the enveloping flux rope helicity (positive). From the coronal magnetic field decay index, n, calculation near the flux rope axis, it is evident that the whole filament axis lies within the domain of stability (i.e., n < 1), which provides the filament stability despite strong disturbances at its eastern foot point.

  10. Magnetic compression laser driving circuit

    DOE Patents [OSTI]

    Ball, Don G. (Livermore, CA); Birx, Dan (Brentwood, CA); Cook, Edward G. (Livermore, CA)

    1993-01-01

    A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 Kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 Kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

  11. Magnetic compression laser driving circuit

    DOE Patents [OSTI]

    Ball, D.G.; Birx, D.; Cook, E.G.

    1993-01-05

    A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

  12. Summary report for nanoscale magnetics

    SciTech Connect (OSTI)

    Tobin, J.G.; Waddill, G.D.; Jankowski, A.F.; Tamura, E.; Sterne, P.A.; Pappas, D.P.; Tong, S.Y.

    1993-09-23

    We have probed the electronic, geometric, and magnetic nanoscale structure of ultrathin magnetic films, both monolayers and multilayers (Fe/Cu(001), FePt, FeCoPt, UFe{sub 2}, U-S). Techniques used included the MCD (magnetic circular dichroism)-variants of of x-ray absorption, core-level photoemission, and photoelectron diffraction. Progress has been made on nanoscale structure-property relations, in part of coupling of world-class experimentation and theoretical modeling. Feasibility of investigations of 5f magnetism using bulk uranium samples also has been demonstrated.

  13. Measurements of magnetic field alignment

    SciTech Connect (OSTI)

    Kuchnir, M.; Schmidt, E.E.

    1987-11-06

    The procedure for installing Superconducting Super Collider (SSC) dipoles in their respective cryostats involves aligning the average direction of their field with the vertical to an accuracy of 0.5 mrad. The equipment developed for carrying on these measurements is described and the measurements performed on the first few prototypes SSC magnets are presented. The field angle as a function of position in these 16.6 m long magnets is a characteristic of the individual magnet with possible feedback information to its manufacturing procedure. A comparison of this vertical alignment characteristic with a magnetic field intensity (by NMR) characteristic for one of the prototypes is also presented. 5 refs., 7 figs.

  14. Wireless power transfer magnetic couplers

    DOE Patents [OSTI]

    Wu, Hunter; Gilchrist, Aaron; Sealy, Kylee

    2016-01-19

    A magnetic coupler is disclosed for wireless power transfer systems. A ferrimagnetic component is capable of guiding a magnetic field. A wire coil is wrapped around at least a portion of the ferrimagnetic component. A screen is capable of blocking leakage magnetic fields. The screen may be positioned to cover at least one side of the ferrimagnetic component and the coil. A distance across the screen may be at least six times an air gap distance between the ferrimagnetic component and a receiving magnetic coupler.

  15. Large Magnetization at Carbon Surfaces

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

    Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure carbon to be magnetic, but for more than ten years scientists have suspected that carbon can be made to be magnetic by doping it with nonmagnetic materials, changing its order ever so slightly. Years ago, the first x-ray images obtained using the scanning transmission x-ray microscope at ALS Beamline 11.0.2 provided

  16. Large Magnetization at Carbon Surfaces

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

    Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure carbon to be magnetic, but for more than ten years scientists have suspected that carbon can be made to be magnetic by doping it with nonmagnetic materials, changing its order ever so slightly. Years ago, the first x-ray images obtained using the scanning transmission x-ray microscope at ALS Beamline 11.0.2 provided

  17. Large Magnetization at Carbon Surfaces

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

    Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure carbon to be magnetic, but for more than ten years scientists have suspected that carbon can be made to be magnetic by doping it with nonmagnetic materials, changing its order ever so slightly. Years ago, the first x-ray images obtained using the scanning transmission x-ray microscope at ALS Beamline 11.0.2 provided

  18. Large Magnetization at Carbon Surfaces

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

    Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure carbon to be magnetic, but for more than ten years scientists have suspected that carbon can be made to be magnetic by doping it with nonmagnetic materials, changing its order ever so slightly. Years ago, the first x-ray images obtained using the scanning transmission x-ray microscope at ALS Beamline 11.0.2 provided

  19. Large Magnetization at Carbon Surfaces

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

    Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure carbon to be magnetic, but for more than ten years scientists have suspected that carbon can be made to be magnetic by doping it with nonmagnetic materials, changing its order ever so slightly. Years ago, the first x-ray images obtained using the scanning transmission x-ray microscope at ALS Beamline 11.0.2 provided

  20. Large Magnetization at Carbon Surfaces

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

    Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure carbon to be magnetic, but for more than ten years scientists have suspected that carbon can be made to be magnetic by doping it with nonmagnetic materials, changing its order ever so slightly. Years ago, the first x-ray images obtained using the scanning transmission x-ray microscope at ALS Beamline 11.0.2 provided

  1. Large Magnetization at Carbon Surfaces

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

    Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure carbon to be magnetic, but for more than ten years scientists have suspected that carbon can be made to be magnetic by doping it with nonmagnetic materials, changing its order ever so slightly. Years ago, the first x-ray images obtained using the scanning transmission x-ray microscope at ALS Beamline 11.0.2 provided

  2. Ground Magnetics | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Ground Magnetics Details Activities (25) Areas (19) Regions (0) NEPA(1) Exploration...

  3. Large Magnetization at Carbon Surfaces

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

    sensors, and data processing. Fortunately, additional research has proven that etching carbon with sulfuric acid can also make the carbon magnetic, opening the door for...

  4. BNL Direct Wind Superconducting Magnets

    SciTech Connect (OSTI)

    Parker, B.; Anerella, M.; Escallier, J.; Ghosh, A.; Jain, A.; Marone, A.; Muratore, A.; Wanderer, P.

    2011-09-12

    BNL developed Direct Wind magnet technology is used to create a variety of complex multi-functional multi-layer superconducting coil structures without the need for creating custom production tooling and fixturing for each new project. Our Direct Wind process naturally integrates prestress into the coil structure so external coil collars and yokes are not needed; the final coil package transverse size can then be very compact. Direct Wind magnets are produced with very good field quality via corrections applied during the course of coil winding. The HERA-II and BEPC-II Interaction Region (IR) magnet, J-PARC corrector and Alpha antihydrogen magnetic trap magnets and our BTeV corrector magnet design are discussed here along with a full length ILC IR prototype magnet presently in production and the coils that were wound for an ATF2 upgrade at KEK. A new IR septum magnet design concept for a 6.2 T combined-function IR magnet for eRHIC, a future RHIC upgrade, is introduced here.

  5. 4D STUDY OF STRAIN GRADIENTS EVOLUTION IN TWINNED NiMnGa SINGLE CRYSTALS UNDER MAGNETIC FIELD

    SciTech Connect (OSTI)

    Barabash, Rozaliya; Xu, Ruqing; Barabash, Oleg M; Sozinov, Alexei

    2014-01-01

    Time-resolved 3D X-ray microscopy with a submicron beam size was used to follow the evolution of strains in off-stoichiometric NiMnGa twinned crystals near type I (hard) twin boundary under magnetic field. Laminate A/B microstructure was revealed near the twin boundaries in A variant. Large strain gradients are observed in the C variant in the immediate vicinity of the type I twin boundary: the lattice is under large tensile strains ~0.4% along the c- axes within first micron. Distinct a and b lattice parameter evolution with temperature and magnetic field is demonstrated. In an applied magnetic field the strain field was observed at larger distances from the twin boundary and becomes more complex. Stochastic twin boundary motion was observed after the magnetic field reaches a certain critical value.

  6. Acceleration during magnetic reconnection

    SciTech Connect (OSTI)

    Beresnyak, Andrey; Li, Hui

    2015-07-16

    The presentation begins with colorful depictions of solar x-ray flares and references to pulsar phenomena. Plasma reconnection is complex, could be x-point dominated or turbulent, field lines could break due to either resistivity or non-ideal effects, such as electron pressure anisotropy. Electron acceleration is sometimes observed, and sometimes not. One way to study this complex problem is to have many examples of the process (reconnection) and compare them; the other way is to simplify and come to something robust. Ideal MHD (E=0) turbulence driven by magnetic energy is assumed, and the first-order acceleration is sought. It is found that dissipation in big (length >100 ion skin depths) current sheets is universal and independent on microscopic resistivity and the mean imposed field; particles are regularly accelerated while experiencing curvature drift in flows driven by magnetic tension. One example of such flow is spontaneous reconnection. This explains hot electrons with a power-law tail in solar flares, as well as ultrashort time variability in some astrophysical sources.

  7. Multiparameter magnetic inspection system with magnetic field control and plural magnetic transducers

    DOE Patents [OSTI]

    Jiles, David C. (Ames, IA)

    1991-04-16

    A multiparameter magnetic inspection system for providing an efficient and economical way to derive a plurality of independent measurements regarding magnetic properties of the magnetic material under investigation. The plurality of transducers for a plurality of different types of measurements operatively connected to the specimen. The transducers are in turn connected to analytical circuits for converting transducer signals to meaningful measurement signals of the magnetic properties of the specimen. The measurement signals are processed and can be simultaneously communicated to a control component. The measurement signals can also be selectively plotted against one another. The control component operates the functioning of the analytical circuits and operates and controls components to impose magnetic fields of desired characteristics upon the specimen. The system therefore allows contemporaneous or simultaneous derivation of the plurality of different independent magnetic properties of the material which can then be processed to derive characteristics of the material.

  8. Multiparameter magnetic inspection system with magnetic field control and plural magnetic transducers

    DOE Patents [OSTI]

    Jiles, D.C.

    1991-04-16

    A multiparameter magnetic inspection system is disclosed for providing an efficient and economical way to derive a plurality of independent measurements regarding magnetic properties of the magnetic material under investigation. The plurality of transducers for a plurality of different types of measurements operatively connected to the specimen. The transducers are in turn connected to analytical circuits for converting transducer signals to meaningful measurement signals of the magnetic properties of the specimen. The measurement signals are processed and can be simultaneously communicated to a control component. The measurement signals can also be selectively plotted against one another. The control component operates the functioning of the analytical circuits and operates and controls components to impose magnetic fields of desired characteristics upon the specimen. The system therefore allows contemporaneous or simultaneous derivation of the plurality of different independent magnetic properties of the material which can then be processed to derive characteristics of the material. 1 figure.

  9. Secondary lift for magnetically levitated vehicles

    DOE Patents [OSTI]

    Cooper, Richard K.

    1976-01-01

    A high-speed terrestrial vehicle that is magnetically levitated by means of magnets which are used to induce eddy currents in a continuous electrically conductive nonferromagnetic track to produce magnetic images that repel the inducing magnet to provide primary lift for the vehicle. The magnets are arranged so that adjacent ones have their fields in opposite directions and the magnets are spaced apart a distance that provides a secondary lift between each magnet and the adjacent magnet's image, the secondary lift being maximized by optimal spacing of the magnets.

  10. EFFECTS OF NON-ISOTROPIC SCATTERING, MAGNETIC HELICITY, AND ADIABATIC FOCUSING ON DIFFUSIVE TRANSPORT OF SOLAR ENERGETIC PARTICLES

    SciTech Connect (OSTI)

    Litvinenko, Yuri E.

    2012-06-10

    Transport of solar energetic particles in interplanetary space is analyzed. A new systematic derivation of the diffusion approximation is given, which incorporates the effects of non-isotropic scattering, magnetic helicity, and adiabatic focusing in a non-uniform large-scale magnetic field. The derivation is based on a system of stochastic differential equations, equivalent to the Fokker-Planck equation, and the new method is a generalization of the Smoluchowski approximation in the theory of the Brownian motion. Simple, physically transparent expressions for the transport coefficients are derived. Different results of earlier treatments of the problem are related to the assumptions regarding the evolving particle distribution.

  11. Engineering characterization of ground motion. Task II. Effects of ground motion characteristics on structural response considering localized structural nonlinearities and soil-structure interaction effects. Volume 2

    SciTech Connect (OSTI)

    Kennedy, R.P.; Kincaid, R.H.; Short, S.A.

    1985-03-01

    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. Task I of the study, which is presented in NUREG/CR-3805, Vol. 1, developed a basis for selecting design response spectra taking into account the characteristics of free-field ground motion found to be significant in causing structural damage. Task II incorporates additional considerations of effects of spatial variations of ground motions and soil-structure interaction on foundation motions and structural response. The results of Task II are presented in four parts: (1) effects of ground motion characteristics on structural response of a typical PWR reactor building with localized nonlinearities and soil-structure interaction effects; (2) empirical data on spatial variations of earthquake ground motion; (3) soil-structure interaction effects on structural response; and (4) summary of conclusions and recommendations based on Tasks I and II studies. This report presents the results of the first part of Task II. The results of the other parts will be presented in NUREG/CR-3805, Vols. 3 to 5.

  12. Magnetic agglomeration method for size control in the synthesis...

    Office of Scientific and Technical Information (OSTI)

    Magnetic agglomeration method for size control in the synthesis of magnetic nanoparticles Title: Magnetic agglomeration method for size control in the synthesis of magnetic ...

  13. SOLAR MAGNETIC TRACKING. IV. THE DEATH OF MAGNETIC FEATURES

    SciTech Connect (OSTI)

    Lamb, D. A.; Howard, T. A.; DeForest, C. E.; Parnell, C. E.; Welsch, B. T.

    2013-09-10

    The removal of magnetic flux from the quiet-Sun photosphere is important for maintaining the statistical steady state of the magnetic field there, for determining the magnetic flux budget of the Sun, and for estimating the rate of energy injected into the upper solar atmosphere. Magnetic feature death is a measurable proxy for the removal of detectable flux, either by cancellation (submerging or rising loops, or reconnection in the photosphere) or by dispersal of flux. We used the SWAMIS feature tracking code to understand how nearly 2 Multiplication-Sign 10{sup 4} magnetic features die in an hour-long sequence of Hinode/SOT/NFI magnetograms of a region of the quiet Sun. Of the feature deaths that remove visible magnetic flux from the photosphere, the vast majority do so by a process that merely disperses the previously detected flux so that it is too small and too weak to be detected, rather than completely eliminating it. The behavior of the ensemble average of these dispersals is not consistent with a model of simple planar diffusion, suggesting that the dispersal is constrained by the evolving photospheric velocity field. We introduce the concept of the partial lifetime of magnetic features, and show that the partial lifetime due to Cancellation of magnetic flux, 22 hr, is three times slower than previous measurements of the flux turnover time. This indicates that prior feature-based estimates of the flux replacement time may be too short, in contrast with the tendency for this quantity to decrease as resolution and instrumentation have improved. This suggests that dispersal of flux to smaller scales is more important for the replacement of magnetic fields in the quiet Sun than observed bipolar cancellation. We conclude that processes on spatial scales smaller than those visible to Hinode dominate the processes of flux emergence and cancellation, and therefore also the quantity of magnetic flux that threads the photosphere.

  14. Quantum chaos and statistical properties of energy levels: Numerical study of the hydrogen atom in a magnetic field

    SciTech Connect (OSTI)

    Delande, D.; Gay, J.C.

    1986-10-20

    The transition to chaos in ''the hydrogen atom in a magnetic field'' is numerically studied and shown to lead to well-defined signature on the energy-level fluctuations. Upon an increase in the energy, the calculated statistics evolve from Poisson to Gaussian orthogonal ensemble according to the regular or chaotic character of the classical motion. Several methods are employed to test the generic nature of these distributions.

  15. Systems and methods for estimating the structure and motion of an object

    DOE Patents [OSTI]

    Dani, Ashwin P; Dixon, Warren

    2015-11-03

    In one embodiment, the structure and motion of a stationary object are determined using two images and a linear velocity and linear acceleration of a camera. In another embodiment, the structure and motion of a stationary or moving object are determined using an image and linear and angular velocities of a camera.

  16. Ambient betatron motion and its excitation by ``ghost lines'' in Tevatron

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

    Shiltsev, Vladimir; Stancari, Giulio; Valishev, Alexander

    2011-08-02

    Transverse betatron motion of the Tevatron proton beam is measured and analysed. It is shown that the motion is coherent and excited by external sources of unknown origins. The observations of the time varying “ghost lines“ in the betatron spectra are reported.

  17. Engineering characterization of strong ground motion recorded at rock sites. Final report

    SciTech Connect (OSTI)

    Silva, W.; Darragh, R.B.

    1995-06-01

    An essential element in the seismic design of critical facilities is a quantitative estimate of ground motion characteristics due to earthquakes. This report confirms the validity of a simple relationship between magnitude, site condition and frequency content of the ground motion that is extremely useful for engineering design purposes.

  18. Phase locking of vortex cores in two coupled magnetic nanopillars

    SciTech Connect (OSTI)

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

    2014-11-15

    Phase locking dynamics of the coupled vortex cores in two identical magnetic spin valves induced by spin-polarized current are studied by means of micromagnetic simulations. Our results show that the available current range of phase locking can be expanded significantly by the use of constrained polarizer, and the vortices undergo large orbit motions outside the polarization areas. The effects of polarization areas and dipolar interaction on the phase locking dynamics are studied systematically. Phase locking parameters extracted from simulations are discussed by theoreticians. The dynamics of vortices influenced by spin valve geometry and vortex chirality are discussed at last. This work provides deeper insights into the dynamics of phase locking and the results are important for the design of spin-torque nano-oscillators.

  19. Magnetic Resonance Facility (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-03-01

    This fact sheet provides information about Magnetic Resonance Facility capabilities and applications at NREL's National Bioenergy Center. Liquid and solid-state analysis capability for a variety of biomass, photovoltaic, and materials characterization applications across NREL. NREL scientists analyze solid and liquid samples on three nuclear magnetic resonance (NMR) spectrometers as well as an electron paramagnetic resonance (EPR) spectrometer.

  20. Magnetic polarizability of the nucleon

    SciTech Connect (OSTI)

    Ragusa, S.

    1996-01-01

    We derive an expression for the magnetic polarizability of the nucleon, as related to sums of products of its electromagnetic transition moments involving the electric and magnetic dipoles and mean-square radii, as well as the electric quadrupole moment. Two sum rules emerge from the calculation. {copyright} {ital 1995 The American Physical Society.}

  1. Exploration of Artificial Frustrated Magnets

    SciTech Connect (OSTI)

    Samarth, Nitin; Schiffer, Peter

    2015-02-17

    This program encompasses experimental and theoretical studies of arrays of nanometer-scale magnets known as “artificial frustrated magnets”. These magnets are small and closely spaced, so that their behavior as a collective group is complex and reveals insights into how such collections of interacting objects behave as a group. In particular, the placement of the magnets is such that the interactions between them are “frustrated”, in that they compete with each other. These systems are analogs to a class of magnetic materials in which the lattice geometry frustrates interactions between individual atomic moments, and in which a wide range of novel physical phenomena have been recently observed. The advantage to studying the arrays is that they are both designable and resolvable: i.e., the experiments can control all aspects of the array geometry, and can also observe how individual elements of the arrays behave. This research program demonstrated a number of phenomena including the role of multiple collective interactions, the feasibility of using systems with their magnetism aligned perpendicular to the plane of the array, the importance of disorder in the arrays, and the possibility of using high temperatures to adjust the magnet orientations. All of these phenomena, and others explored in this program, add to the body of knowledge around collective magnetic behavior and magnetism in general. Aside from building scientific knowledge in an important technological area, with relevance to computing and memory, the program also gave critical support to the education of students working on the experiments.

  2. Magnetic-field-dosimetry system

    DOE Patents [OSTI]

    Lemon, D.K.; Skorpik, J.R.; Eick, J.L.

    1981-01-21

    A device is provided for measuring the magnetic field dose and peak field exposure. The device includes three Hall-effect sensors all perpendicular to each other, sensing the three dimensional magnetic field and associated electronics for data storage, calculating, retrieving and display.

  3. Superconducting magnetic energy storage

    SciTech Connect (OSTI)

    Hassenzahl, W.

    1988-08-01

    Recent programmatic developments in Superconducting Magnetic Energy Storage (SMES) have prompted renewed and widespread interest in this field. In mid 1987 the Defense Nuclear Agency, acting for the Strategic Defense Initiative Office, issued a request for proposals for the design and construction of SMES Engineering Test Model (ETM). Two teams, one led by Bechtel and the other by Ebasco, are now engaged in the first phase of the development of a 10 to 20 MWhr ETM. This report presents the rationale for energy storage on utility systems, describes the general technology of SMES, and explains the chronological development of the technology. The present ETM program is outlined; details of the two projects for ETM development are described in other papers in these proceedings. The impact of high T/sub c/ materials on SMES is discussed. 69 refs., 3 figs., 3 tabs.

  4. Josephson magnetic rotary valve

    SciTech Connect (OSTI)

    Soloviev, I. I.; Klenov, N. V.; Bakurskiy, S. V.; Bol'ginov, V. V.; Ryazanov, V. V.; Kupriyanov, M. Yu.; Golubov, A. A.

    2014-12-15

    We propose a control element for a Josephson spin valve. It is a complex Josephson device containing ferromagnetic (F) layer in the weak-link area consisting of two regions, representing 0 and π Josephson junctions, respectively. The valve's state is defined by mutual orientations of the F-layer magnetization vector and boundary line between 0 and π sections of the device. We consider possible implementation of the control element by introduction of a thin normal metal layer in a part of the device area. By means of theoretical simulations, we study properties of the valve's structure as well as its operation, revealing such advantages as simplicity of control, high characteristic frequency, and good legibility of the basic states.

  5. Vertical air motions over the Tropical Western Pacific for validating cloud resolving and regional models

    SciTech Connect (OSTI)

    Williams, Christopher R.

    2015-03-16

    The objective of this project was to estimate the vertical air motion using Doppler velocity spectra from two side-by-side vertically pointing radars. The retrieval technique was applied to two different sets of radars. This first set was 50- and 920-MHz vertically pointing radars near Darwin, Australia. The second set was 449-MHz and 2.8-GHz vertically pointing radars deployed at SGP for MC3E. The retrieval technique uses the longer wavelength radar (50 or 449 MHz) to observe both the vertical air motion and precipitation motion while the shorter wavelength radar (920 MHz or 2.8 GHz) observes just the precipitation motion. By analyzing their Doppler velocity spectra, the precipitation signal in the 920 MHz or 2.8 GHz radar is used to mask-out the precipitation signal in the 50 or 449 MHz radar spectra, leaving just the vertical air motion signal.

  6. Method and system for controlling a permanent magnet machine

    DOE Patents [OSTI]

    Walters, James E.

    2003-05-20

    Method and system for controlling the start of a permanent magnet machine are provided. The method allows to assign a parameter value indicative of an estimated initial rotor position of the machine. The method further allows to energize the machine with a level of current being sufficiently high to start rotor motion in a desired direction in the event the initial rotor position estimate is sufficiently close to the actual rotor position of the machine. A sensing action allows to sense whether any incremental changes in rotor position occur in response to the energizing action. In the event no changes in rotor position are sensed, the method allows to incrementally adjust the estimated rotor position by a first set of angular values until changes in rotor position are sensed. In the event changes in rotor position are sensed, the method allows to provide a rotor alignment signal as rotor motion continues. The alignment signal allows to align the estimated rotor position relative to the actual rotor position. This alignment action allows for operating the machine over a wide speed range.

  7. Effects of thermal motion on electromagnetically induced absorption

    SciTech Connect (OSTI)

    Tilchin, E.; Wilson-Gordon, A. D.; Firstenberg, O. [Department of Chemistry, Bar-Ilan University, Ramat Gan IL-52900 (Israel); Department of Physics, Technion-Israel Institute of Technology, Haifa IL-32000 (Israel)

    2011-05-15

    We describe the effect of thermal motion and buffer-gas collisions on a four-level closed N system interacting with strong pump(s) and a weak probe. This is the simplest system that experiences electromagnetically induced absorption (EIA) due to transfer of coherence via spontaneous emission from the excited state to the ground state. We investigate the influence of Doppler broadening, velocity-changing collisions (VCC), and phase-changing collisions (PCC) with a buffer gas on the EIA spectrum of optically active atoms. In addition to exact expressions, we present an approximate solution for the probe absorption spectrum, which provides physical insight into the behavior of the EIA peak due to VCC, PCC, and the wave-vector difference between the pump and probe beams. VCC are shown to produce a wide pedestal at the base of the EIA peak, which is scarcely affected by the pump-probe angular deviation, whereas the sharp central EIA peak becomes weaker and broader due to the residual Doppler-Dicke effect. Using diffusionlike equations for the atomic coherences and populations, we construct a spatial-frequency filter for a spatially structured probe beam and show that Ramsey narrowing of the EIA peak is obtained for beams of finite width.

  8. Permanent-magnet multipole with adjustable strength

    DOE Patents [OSTI]

    Halbach, K.

    1982-09-20

    Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling there between. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

  9. Permanent magnet multipole with adjustable strength

    DOE Patents [OSTI]

    Halbach, Klaus

    1985-01-01

    Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling therebetween. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

  10. Plated lamination structures for integrated magnetic devices

    DOE Patents [OSTI]

    Webb, Bucknell C.

    2014-06-17

    Semiconductor integrated magnetic devices such as inductors, transformers, etc., having laminated magnetic-insulator stack structures are provided, wherein the laminated magnetic-insulator stack structures are formed using electroplating techniques. For example, an integrated laminated magnetic device includes a multilayer stack structure having alternating magnetic and insulating layers formed on a substrate, wherein each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by an insulating layer, and a local shorting structure to electrically connect each magnetic layer in the multilayer stack structure to an underlying magnetic layer in the multilayer stack structure to facilitate electroplating of the magnetic layers using an underlying conductive layer (magnetic or seed layer) in the stack as an electrical cathode/anode for each electroplated magnetic layer in the stack structure.

  11. Disorder-Induced Microscopic Magnetic Memory

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

    Disorder-Induced Microscopic Magnetic Memory Disorder-Induced Microscopic Magnetic Memory Print Wednesday, 26 October 2005 00:00 The magnetic-recording industry deliberately introduces carefully controlled disorder into its materials to obtain the desired magnetic properties. But as the density of magnetic disks climbs, the size of the magnetic domains responsible for storage must decrease, posing new challenges. Beautiful theories based on random microscopic disorder have been developed over

  12. Nuclear magnetic resonance investigation of dynamics in poly(ethylene oxide)-based lithium polyether-ester-sulfonate ionomers

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

    Roach, David J.; Dou, Shichen; Colby, Ralph H.; Mueller, Karl T.

    2012-01-06

    Nuclear magnetic resonance (NMR) spectroscopy has been utilized to investigate the dynamics of poly(ethylene oxide)-based lithium sulfonate ionomer samples that have low glass transition temperatures. 1H and 7Li spin-lattice relaxation times (T1) of the bulk polymer and lithium ions, respectively, were measured and analyzed in samples with a range of ion contents. The temperature dependence of T1 values along with the presence of minima in T1 as a function of temperature enabled correlation times and activation energies to be obtained for both the segmental motion of the polymer backbone and the hopping motion of lithium cations. Similar activation energies formore » motion of both the polymer and lithium ions in the samples with lower ion content indicate that the polymer segmental motion and lithium ion hopping motion are correlated in these samples, even though their respective correlation times differ significantly. A divergent trend is observed for correlation times and activation energies of the highest ion content sample with 100% lithium sulfonation due to the presence of ionic aggregation. Details of the polymer and cation dynamics on the nanosecond timescale are discussed and complement the findings of X-ray scattering and Quasi Elastic Neutron Scattering experiments.« less

  13. Magnetic Pair Spectrometer Studies of Electromagnetic Transitions...

    Office of Scientific and Technical Information (OSTI)

    Warburton, E. K. PHYSICS; BRANCHING RATIO; CARBON 13; CARBON 14; DECAY; DEUTERON BEAMS; ELECTRIC CHARGES; ENERGY; ENERGY LEVELS; ERRORS; LIFETIME; MAGNETIC FIELDS; MAGNETIC...

  14. Magnetic Pair Spectrometer Studies of Electromagnetic Transitions...

    Office of Scientific and Technical Information (OSTI)

    English Subject: PHYSICS; BRANCHING RATIO; CARBON 13; CARBON 14; DECAY; DEUTERON BEAMS; ELECTRIC CHARGES; ENERGY; ENERGY LEVELS; ERRORS; LIFETIME; MAGNETIC FIELDS; MAGNETIC...

  15. Category:Ground Magnetics | Open Energy Information

    Open Energy Info (EERE)

    Ground Magnetics Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Ground Magnetics page? For detailed information on Ground...

  16. Interfacial Magnetism in Complex Oxide Heterostructures Probed...

    Office of Scientific and Technical Information (OSTI)

    Interfacial Magnetism in Complex Oxide Heterostructures Probed by Neutrons and X-rays This ... Next Title: Interfacial Magnetism in Complex Oxide Heterostructures Probed by Neutrons ...

  17. Magnetic diagnostics for equilibrium reconstructions with eddy...

    Office of Scientific and Technical Information (OSTI)

    Magnetic diagnostics for equilibrium reconstructions with eddy currents on the lithium tokamak experimenta) Citation Details In-Document Search Title: Magnetic diagnostics for...

  18. National High Magnetic Field Laboratory moves closer

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

    researchers to carefully tune material parameters while perfectly reproducing the non-invasive magnetic field. Such high magnetic fields confine electrons to nanometer scale...

  19. Design Principles for Materials with Magnetic Functionality ...

    Office of Scientific and Technical Information (OSTI)

    Design Principles for Materials with Magnetic Functionality Citation Details In-Document Search Title: Design Principles for Materials with Magnetic Functionality This report ...

  20. Direct Imaging of Asymmetric Magnetization Reversal

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

    Direct Imaging of Asymmetric Magnetization Reversal Print The phenomenon of exchange bias has transformed how data is read on magnetic hard disks and created an explosion in their...

  1. Direct Imaging of Asymmetric Magnetization Reversal

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

    Direct Imaging of Asymmetric Magnetization Reversal Direct Imaging of Asymmetric Magnetization Reversal Print Wednesday, 28 September 2005 00:00 The phenomenon of exchange bias has...

  2. Disorder-Induced Microscopic Magnetic Memory

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

    Disorder-Induced Microscopic Magnetic Memory Print The magnetic-recording industry deliberately introduces carefully controlled disorder into its materials to obtain the desired...

  3. Magnetic filtration process, magnetic filtering material, and methods of forming magnetic filtering material

    DOE Patents [OSTI]

    Taboada-Serrano, Patricia; Tsouris, Constantino; Contescu, Cristian I; McFarlane, Joanna

    2013-10-08

    The present invention provides magnetically responsive activated carbon, and a method of forming magnetically responsive activated carbon. The method of forming magnetically responsive activated carbon typically includes providing activated carbon in a solution containing ions of ferrite forming elements, wherein at least one of the ferrite forming elements has an oxidation state of +3 and at least a second of the ferrite forming elements has an oxidation state of +2, and increasing pH of the solution to precipitate particles of ferrite that bond to the activated carbon, wherein the activated carbon having the ferrite particles bonded thereto have a positive magnetic susceptibility. The present invention also provides a method of filtering waste water using magnetic activated carbon.

  4. Effects of Respiratory Motion on Passively Scattered Proton Therapy Versus Intensity Modulated Photon Therapy for Stage III Lung Cancer: Are Proton Plans More Sensitive to Breathing Motion?

    SciTech Connect (OSTI)

    Matney, Jason; Park, Peter C. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); The University of Texas Graduate School of Biomedical Sciences, Houston, Texas (United States); Bluett, Jaques [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chen, Yi Pei [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); The University of Texas Graduate School of Biomedical Sciences, Houston, Texas (United States); Liu, Wei; Court, Laurence E. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liao, Zhongxing [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Li, Heng [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mohan, Radhe, E-mail: rmohan@mdanderson.org [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2013-11-01

    Purpose: To quantify and compare the effects of respiratory motion on paired passively scattered proton therapy (PSPT) and intensity modulated photon therapy (IMRT) plans; and to establish the relationship between the magnitude of tumor motion and the respiratory-induced dose difference for both modalities. Methods and Materials: In a randomized clinical trial comparing PSPT and IMRT, radiation therapy plans have been designed according to common planning protocols. Four-dimensional (4D) dose was computed for PSPT and IMRT plans for a patient cohort with respiratory motion ranging from 3 to 17 mm. Image registration and dose accumulation were performed using grayscale-based deformable image registration algorithms. The dosevolume histogram (DVH) differences (4D-3D [3D = 3-dimensional]) were compared for PSPT and IMRT. Changes in 4D-3D dose were correlated to the magnitude of tumor respiratory motion. Results: The average 4D-3D dose to 95% of the internal target volume was close to zero, with 19 of 20 patients within 1% of prescribed dose for both modalities. The mean 4D-3D between the 2 modalities was not statistically significant (P<.05) for all dosevolume histogram indices (mean SD) except the lung V5 (PSPT: +1.1% 0.9%; IMRT: +0.4% 1.2%) and maximum cord dose (PSPT: +1.5 2.9 Gy; IMRT: 0.0 0.2 Gy). Changes in 4D-3D dose were correlated to tumor motion for only 2 indices: dose to 95% planning target volume, and heterogeneity index. Conclusions: With our current margin formalisms, target coverage was maintained in the presence of respiratory motion up to 17 mm for both PSPT and IMRT. Only 2 of 11 4D-3D indices (lung V5 and spinal cord maximum) were statistically distinguishable between PSPT and IMRT, contrary to the notion that proton therapy will be more susceptible to respiratory motion. Because of the lack of strong correlations with 4D-3D dose differences in PSPT and IMRT, the extent of tumor motion was not an adequate predictor of potential dosimetric error caused by breathing motion.

  5. Seismic Safety Program: Ground motion and structural response

    SciTech Connect (OSTI)

    Not Available

    1993-05-01

    In 1964, John A. Blume & Associates Research Division (Blume) began a broad-range structural response program to assist the Nevada Operations Office of the US Atomic Energy Commission (AEC) in ensuring the continued safe conduct of underground nuclear detonation testing at the Nevada Test Site (NTS) and elsewhere. Blume`s long experience in earthquake engineering provided a general basis for the program, but much more specialized knowledge was required for the AEC`s purposes. Over the next 24 years Blume conducted a major research program to provide essential understanding of the detailed nature of the response of structures to dynamic loads such as those imposed by seismic wave propagation. The program`s results have been embodied in a prediction technology which has served to provide reliable advanced knowledge of the probable effects of seismic ground motion on all kinds of structures, for use in earthquake engineering and in building codes as well as for the continuing needs of the US Department of Energy`s Nevada Operations Office (DOE/NV). This report is primarily an accounting of the Blume work, beginning with the setting in 1964 and the perception of the program needs as envisioned by Dr. John A. Blume. Subsequent chapters describe the structural response program in detail and the structural prediction procedures which resulted; the intensive data acquisition program which, as is discussed at some length, relied heavily on the contributions of other consultant-contractors in the DOE/NV Seismic Safety Support Program; laboratory and field studies to provide data on building elements and structures subjected to dynamic loads from sources ranging from testing machines to earthquakes; structural response activities undertaken for testing at the NTS and for off-NTS underground nuclear detonations; and concluding with an account of corollary studies including effects of natural forces and of related studies on building response.

  6. Phase coded, micro-power impulse radar motion sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1996-05-21

    A motion sensing, micro-power impulse radar MIR impresses on the transmitted signal, or the received pulse timing signal, one or more frequencies lower than the pulse repetition frequency, that become intermediate frequencies in a ``IF homodyne`` receiver. Thus, many advantages of classical RF receivers can be thereby be realized with ultra-wide band radar. The sensor includes a transmitter which transmits a sequence of electromagnetic pulses in response to a transmit timing signal at a nominal pulse repetition frequency. A receiver samples echoes of the sequence of electromagnetic pulses from objects within the field with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The relative timing of the transmit timing signal and the receive timing signal is modulated between a first relative delay and a second relative delay at an intermediate frequency, causing the receiver to sample the echoes such that the time between transmissions of pulses in the sequence and samples by the receiver is modulated at the intermediate frequency. Modulation may be executed by modulating the pulse repetition frequency which drives the transmitter, by modulating the delay circuitry which controls the relative timing of the sample strobe, or by modulating amplitude of the transmitted pulses. The electromagnetic pulses will have a nominal center frequency related to pulse width, and the first relative delay and the second relative delay between which the timing signals are modulated, differ by less than the nominal pulse width, and preferably by about one-quarter wavelength at the nominal center frequency of the transmitted pulses. 5 figs.

  7. Phase coded, micro-power impulse radar motion sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1996-01-01

    A motion sensing, micro-power impulse radar MIR impresses on the transmitted signal, or the received pulse timing signal, one or more frequencies lower than the pulse repetition frequency, that become intermediate frequencies in a "IF homodyne" receiver. Thus, many advantages of classical RF receivers can be thereby be realized with ultra-wide band radar. The sensor includes a transmitter which transmits a sequence of electromagnetic pulses in response to a transmit timing signal at a nominal pulse repetition frequency. A receiver samples echoes of the sequence of electromagnetic pulses from objects within the field with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The relative timing of the transmit timing signal and the receive timing signal is modulated between a first relative delay and a second relative delay at an intermediate frequency, causing the receiver to sample the echoes such that the time between transmissions of pulses in the sequence and samples by the receiver is modulated at the intermediate frequency. Modulation may be executed by modulating the pulse repetition frequency which drives the transmitter, by modulating the delay circuitry which controls the relative timing of the sample strobe, or by modulating amplitude of the transmitted pulses. The electromagnetic pulses will have a nominal center frequency related to pulse width, and the first relative delay and the second relative delay between which the timing signals are modulated, differ by less than the nominal pulse width, and preferably by about one-quarter wavelength at the nominal center frequency of the transmitted pulses.

  8. INVESTIGATION OF CRUSTAL MOTION IN THE TIEN SHAN USING INSAR

    SciTech Connect (OSTI)

    Mellors, R J

    2011-02-25

    The northern Tien Shan of Central Asia is an area of active mid-continent deformation. Although far from a plate boundary, this region has experienced 5 earthquakes larger than magnitude 7 in the past century and includes one event that may as be as large as Mw 8.0. Previous studies based on GPS measurements indicate on the order of 23 mm/yr of shortening across the entire Tien Shan and up to 15 mm/year in the northern Tien Shan (Figure 1). The seismic moment release rate appears comparable with the geodetic measured slip, at least to first order, suggesting that geodetic rates can be considered a proxy for accumulation rates of stress for seismic hazard estimation. Interferometric synthetic aperture radar may provide a means to make detailed spatial measurements and hence in identifying block boundaries and assisting in seismic hazard. Therefore, we hoped to define block boundaries by direct measurement and by identifying and resolving earthquake slip. Due to political instability in Kyrgzystan, the existing seismic network has not performed as well as required to precisely determine earthquake hypocenters in remote areas and hence InSAR is highly useful. In this paper we present the result of three earthquake studies and show that InSAR is useful for refining locations of teleseismically located earthquakes. ALOS PALSAR data is used to investigate crustal motion in the Tien Shan mountains of Central Asia. As part of the work, considerable software development was undertaken to process PALSAR data. This software has been made freely available. Two damaging earthquakes have been imaged in the Tien Shan and the locations provided by ALOS InSAR have helped to refine seismological velocity models. A third earthquake south of Kyrgyzstan was also imaged. The use of InSAR data and especially L band is therefore very useful in providing groundtruth for earthquake locations.

  9. Nuclear magnetic resonance contrast agents

    DOE Patents [OSTI]

    Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

    1997-12-30

    A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 10 figs.

  10. Magnetic microbes: Bacterial magnetite biomineralization

    SciTech Connect (OSTI)

    Prozorov, Tanya

    2015-09-14

    Magnetotactic bacteria are a diverse group of prokaryotes with the ability to orient and migrate along the magnetic field lines in search for a preferred oxygen concentration in chemically stratified water columns and sediments. These microorganisms produce magnetosomes, the intracellular nanometer-sized magnetic crystals surrounded by a phospholipid bilayer membrane, typically organized in chains. Magnetosomes have nearly perfect crystal structures with narrow size distribution and species-specific morphologies, leading to well-defined magnetic properties. As a result, the magnetite biomineralization in these organisms is of fundamental interest to diverse disciplines, from biotechnology to astrobiology. As a result, this article highlights recent advances in the understanding of the bacterial magnetite biomineralization.

  11. Nuclear magnetic resonance contrast agents

    DOE Patents [OSTI]

    Smith, Paul H.; Brainard, James R.; Jarvinen, Gordon D.; Ryan, Robert R.

    1997-01-01

    A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC.sub.16 H.sub.14 N.sub.6. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques.

  12. Magnetic cellulose-derivative structures

    DOE Patents [OSTI]

    Walsh, M.A.; Morris, R.S.

    1986-09-16

    Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorption agents can be incorporated during the manufacture of the structure. 3 figs.

  13. Magnetic cellulose-derivative structures

    DOE Patents [OSTI]

    Walsh, Myles A. (Falmouth, MA); Morris, Robert S. (Fairhaven, MA)

    1986-09-16

    Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorbtion agents can be incorporated during the manufacture of the structure.

  14. Periodic permanent magnet focused klystron

    DOE Patents [OSTI]

    Ferguson, Patrick; Read, Michael; Ives, R Lawrence

    2015-04-21

    A periodic permanent magnet (PPM) klystron has beam transport structures and RF cavity structures, each of which has permanent magnets placed substantially equidistant from a beam tunnel formed about the central axis, and which are also outside the extent of a cooling chamber. The RF cavity sections also have permanent magnets which are placed substantially equidistant from the beam tunnel, but which include an RF cavity coupling to the beam tunnel for enhancement of RF carried by an electron beam in the beam tunnel.

  15. Improved superconducting magnet wire

    DOE Patents [OSTI]

    Schuller, I.K.; Ketterson, J.B.

    1983-08-16

    This invention is directed to a superconducting tape or wire composed of alternating layers of copper and a niobium-containing superconductor such as niobium of NbTi, Nb/sub 3/Sn or Nb/sub 3/Ge. In general, each layer of the niobium-containing superconductor has a thickness in the range of about 0.05 to 1.5 times its coherence length (which for Nb/sub 3/Si is 41 A) with each copper layer having a thickness in the range of about 170 to 600 A. With the use of very thin layers of the niobium composition having a thickness within the desired range, the critical field (H/sub c/) may be increased by factors of 2 to 4. Also, the thin layers of the superconductor permit the resulting tape or wire to exhibit suitable ductility for winding on a magnet core. These compositions are also characterized by relatively high values of critical temperature and therefore will exhibit a combination of useful properties as superconductors.

  16. Dynamics of Dirac strings and monopolelike excitations in chiral magnets under a current drive

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

    Lin, Shi -Zeng; Saxena, Avadh

    2016-02-10

    Skyrmion lines in metallic chiral magnets carry an emergent magnetic field experienced by the conduction electrons. The inflow and outflow of this field across a closed surface is not necessarily equal, thus it allows for the existence of emergent monopoles. One example is a segment of skyrmion line inside a crystal, where a monopole and antimonopole pair is connected by the emergent magnetic flux line. This is a realization of Dirac stringlike excitations. Here we study the dynamics of monopoles in chiral magnets under an electric current. We show that in the process of creation of skyrmion lines, skyrmion linemore » segments are first created via the proliferation of monopoles and antimonopoles. Then these line segments join and span the whole system through the annihilation of monopoles. The skyrmion lines are destroyed via the proliferation of monopoles and antimonopoles at high currents, resulting in a chiral liquid phase. We also propose to create the monopoles in a controlled way by applying an inhomogeneous current to a crystal. Remarkably, an electric field component in the magnetic field direction proportional to the current squared in the low current region is induced by the motion of distorted skyrmion lines, in addition to the Hall and longitudinal voltage. As a result, the existence of monopoles can be inferred from transport or imaging measurements.« less

  17. SCATTERING OF THE f-MODE BY SMALL MAGNETIC FLUX ELEMENTS FROM OBSERVATIONS AND NUMERICAL SIMULATIONS

    SciTech Connect (OSTI)

    Felipe, T.; Braun, D.; Crouch, A.; Birch, A.

    2012-10-01

    The scattering of f-modes by magnetic tubes is analyzed using three-dimensional numerical simulations. An f-mode wave packet is propagated through a solar atmosphere embedded with three different flux tube models that differ in radius and total magnetic flux. A quiet-Sun simulation without a tube present is also performed as a reference. Waves are excited inside the flux tube and propagate along the field lines, and jacket modes are generated in the surroundings of the flux tube, carrying 40% as much energy as the tube modes. The resulting scattered wave is mainly an f-mode composed of a mixture of m = 0 and m = {+-}1 modes. The amplitude of the scattered wave approximately scales with the magnetic flux. A small amount of power is scattered into the p{sub 1}-mode. We have evaluated the absorption and phase shift from a Fourier-Hankel decomposition of the photospheric vertical velocities. They are compared with the results obtained from the ensemble average of 3400 small magnetic elements observed in high-resolution MDI Doppler datacubes. The comparison shows that the observed dependence of the phase shift with wavenumber can be matched reasonably well with the simulated flux tube model. The observed variation of the phase shifts with the azimuthal order m appears to depend on details of the ensemble averaging, including possible motions of the magnetic elements and asymmetrically shaped elements.

  18. THREE-DIMENSIONAL STRUCTURE OF MICROWAVE SOURCES FROM SOLAR ROTATION STEREOSCOPY VERSUS MAGNETIC EXTRAPOLATIONS

    SciTech Connect (OSTI)

    Nita, Gelu M.; Fleishman, Gregory D.; Gary, Dale E.; Jing, Ju; Wang, Haimin; Lesovoi, Sergey V.; Bogod, Vladimir M.; Yasnov, Leonid V.

    2011-08-20

    We use rotation stereoscopy to estimate the height of a steady-state solar feature relative to the photosphere, based on its apparent motion in the image plane recorded over several days of observation. The stereoscopy algorithm is adapted to work with either one- or two-dimensional data (i.e., from images or from observations that record the projected position of the source along an arbitrary axis). The accuracy of the algorithm is tested on simulated data, and then the algorithm is used to estimate the coronal radio source heights associated with the active region NOAA 10956, based on multifrequency imaging data over seven days from the Siberian Solar Radio Telescope near 5.7 GHz, the Nobeyama Radio Heliograph at 17 GHz, as well as one-dimensional scans at multiple frequencies spanning the 5.98-15.95 GHz frequency range from the RATAN-600 instrument. The gyroresonance emission mechanism, which is sensitive to the coronal magnetic field strength, is applied to convert the estimated radio source heights at various frequencies, h(f), to information about magnetic field versus height B(h), and the results are compared to a magnetic field extrapolation derived from photospheric magnetic field observations obtained by Hinode and Michelson Doppler Imager. We found that the gyroresonant emission comes from heights exceeding the location of the third gyrolayer irrespective of the magnetic extrapolation method; implications of this finding for coronal magnetography and coronal plasma physics are discussed.

  19. Magnetic-compression/magnetized-target fusion (MAGO/MTF): A marriage of inertial and magnetic confinement

    SciTech Connect (OSTI)

    Lindemuth, I.R.; Ekdahl, C.A.; Kirkpatrick, R.C.

    1996-12-31

    Intermediate between magnetic confinement (MFE) and inertial confinement (ICF) in time and density scales is an area of research now known in the US as magnetized target fusion (MTF) and in Russian as MAGO (MAGnitnoye Obzhatiye--magnetic compression). MAGO/MTF uses a magnetic field and preheated, wall-confined plasma fusion fuel within an implodable fusion target. The magnetic field suppresses thermal conduction losses in the fuel during the target implosion and hydrodynamic compression heating process. In contrast to direct, hydrodynamic compression of initially ambient-temperature fuel (i.e., ICF), MAGO/MTF involves two steps: (a) formation of a warm (e.g., 100 eV or higher), magnetized (e.g., 100 kG) plasma within a fusion target prior to implosion; (b) subsequent quasi-adiabatic compression by an imploding pusher, of which a magnetically driven imploding liner is one example. In this paper, the authors present ongoing activities and potential future activities in this relatively unexplored area of controlled thermonuclear fusion.

  20. Motion to Intervene Out of Time and Comments of FirstEnergy Service Company

    Energy Savers [EERE]

    PP-230-3 | Department of Energy and Comments of FirstEnergy Service Company PP-230-3 Motion to Intervene Out of Time and Comments of FirstEnergy Service Company PP-230-3 Motion to Intervene Out of Time and Comments of FirstEnergy Service Company PDF icon Motion to Intervene Out of Time and Comments of FirstEnergy Service Company PP-230-3 More Documents & Publications PP-230-3 International Transmission Company Application for presidential permit OE Docket No. PP-230-4 International