National Library of Energy BETA

Sample records for type permanent magnet

  1. 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.

  2. 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.

  3. Cylindrical Hall Thrusters with Permanent Magnets

    SciTech Connect (OSTI)

    Raitses, Yevgeny; Merino, Enrique; Fisch, Nathaniel J.

    2010-10-18

    The use of permanent magnets instead of electromagnet coils for low power Hall thrusters can offer a significant reduction of both the total electric power consumption and the thruster mass. Two permanent magnet versions of the miniaturized cylindrical Hall thruster (CHT) of different overall dimensions were operated in the power range of 50W-300 W. The discharge and plasma plume measurements revealed that the CHT thrusters with permanent magnets and electromagnet coils operate rather differently. In particular, the angular ion current density distribution from the permanent magnet thrusters has an unusual halo shape, with a majority of high energy ions flowing at large angles with respect to the thruster centerline. Differences in the magnetic field topology outside the thruster channel and in the vicinity of the channel exit are likely responsible for the differences in the plume characteristics measured for the CHTs with electromagnets and permanent magnets. It is shown that the presence of the reversing-direction or cusp-type magnetic field configuration inside the thruster channel without a strong axial magnetic field outside the thruster channel does not lead to the halo plasma plume from the CHT. __________________________________________________

  4. 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.

  5. 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.

  6. Are Permanent Magnets Really Permanent? | GE Global Research

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

    Are Permanent Magnets Really Permanent? Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) Are Permanent Magnets Really Permanent? 2012.07.13 Chief Scientist Jim Bray describes how permanent magnets in motors and generators may lose force over time. 0 Comments Comment Name Email Submit Comment You Might Also Like 2-2-5-v

  7. Making permanent magnets more powerful and less expensive | The...

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

    Making permanent magnets more powerful and less expensive Today's high-tech and clean energy capabilities are extremely reliant on powerful permanent magnets. Permanent magnets...

  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. Rare-Earth-Free Permanent Magnets for Electrical Vehicle Motors and Wind Turbine Generators: Hexagonal Symmetry Based Materials Systems Mn-Bi and M-type Hexaferrite

    SciTech Connect (OSTI)

    Hong, Yang-Ki; Haskew, Timothy; Myryasov, Oleg; Jin, Sungho; Berkowitz, Ami

    2014-06-05

    The research we conducted focuses on the rare-earth (RE)-free permanent magnet by modeling, simulating, and synthesizing exchange coupled two-phase (hard/soft) RE-free core-shell nano-structured magnet. The RE-free magnets are made of magnetically hard core materials (high anisotropy materials including Mn-Bi-X and M-type hexaferrite) coated by soft shell materials (high magnetization materials including Fe-Co or Co). Therefore, our research helps understand the exchange coupling conditions of the core/shell magnets, interface exchange behavior between core and shell materials, formation mechanism of core/shell structures, stability conditions of core and shell materials, etc.

  11. Nonuniform radiation damage in permanent magnet quadrupoles

    SciTech Connect (OSTI)

    Danly, C. R.; Merrill, F. E.; Barlow, D.; Mariam, F. G.

    2014-08-15

    We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL’s pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

  12. Permanent magnet edge-field quadrupole

    DOE Patents [OSTI]

    Tatchyn, R.O.

    1997-01-21

    Planar permanent magnet edge-field quadrupoles for use in particle accelerating machines and in insertion devices designed to generate spontaneous or coherent radiation from moving charged particles are disclosed. The invention comprises four magnetized rectangular pieces of permanent magnet material with substantially similar dimensions arranged into two planar arrays situated to generate a field with a substantially dominant quadrupole component in regions close to the device axis. 10 figs.

  13. Permanent magnet edge-field quadrupole

    DOE Patents [OSTI]

    Tatchyn, Roman O.

    1997-01-01

    Planar permanent magnet edge-field quadrupoles for use in particle accelerating machines and in insertion devices designed to generate spontaneous or coherent radiation from moving charged particles are disclosed. The invention comprises four magnetized rectangular pieces of permanent magnet material with substantially similar dimensions arranged into two planar arrays situated to generate a field with a substantially dominant quadrupole component in regions close to the device axis.

  14. 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.

  15. A New Class of Switched Reluctance Motors without Permanent Magnets...

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

    Motors without Permanent Magnets A New Class of Switched Reluctance Motors without Permanent Magnets 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program ...

  16. Jiangxi Jinli Permanent Magnet Technology Co Ltd | Open Energy...

    Open Energy Info (EERE)

    Jinli Permanent Magnet Technology Co Ltd Jump to: navigation, search Name: Jiangxi Jinli Permanent Magnet Technology Co Ltd Place: Ganzhou, Jiangxi Province, China Sector: Wind...

  17. Dovetail spoke internal permanent magnet machine

    DOE Patents [OSTI]

    Alexander, James Pellegrino; EL-Refaie, Ayman Mohamed Fawzi; Lokhandwalla, Murtuza; Shah, Manoj Ramprasad; VanDam, Jeremy Daniel

    2011-08-23

    An internal permanent magnet (IPM) machine is provided. The IPM machine includes a stator assembly and a stator core. The stator core also includes multiple stator teeth. The stator assembly is further configured with stator windings to generate a stator magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface defining a cavity. The IPM machine also includes a rotor assembly and a rotor core. The rotor core is disposed inside the cavity and configured to rotate about the longitudinal axis. The rotor assembly further includes a shaft. The shaft further includes multiple protrusions alternately arranged relative to multiple bottom structures provided on the shaft. The rotor assembly also includes multiple stacks of laminations disposed on the protrusions and dovetailed circumferentially around the shaft. The rotor assembly further includes multiple pair of permanent magnets for generating a magnetic field, which magnetic field interacts with the stator magnetic field to produce a torque. The multiple pair of permanent magnets are disposed between the stacks. The rotor assembly also includes multiple middle wedges mounted between each pair of the multiple permanent magnets.

  18. Permanent Magnet Development for Automotive Traction Motors | Department of

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

    Energy Permanent Magnet Development for Automotive Traction Motors Permanent Magnet Development for Automotive Traction Motors 2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C. ape015_anderson_2010_o.pdf (2.46 MB) More Documents & Publications Permanent Magnet Development for Automotive Traction Motors Permanent Magnet Development for Automotive Traction Motors Permanent Magnet Development for

  19. Robust ferromagnetism in the compressed permanent magnet Sm 2...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Robust ferromagnetism in the compressed permanent magnet Sm 2 Co 17 Citation Details In-Document Search Title: Robust ferromagnetism in the compressed permanent ...

  20. Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization

    DOE Patents [OSTI]

    Doughty, Frank C. (Plano, TX); Spencer, John E. (Plano, TX)

    2000-12-19

    In a plasma-producing device, an optimized magnet field for electron cyclotron resonance plasma generation is provided by a shaped pole piece. The shaped pole piece adjusts spacing between the magnet and the resonance zone, creates a convex or concave resonance zone, and decreases stray fields between the resonance zone and the workpiece. For a cylindrical permanent magnet, the pole piece includes a disk adjacent the magnet together with an annular cylindrical sidewall structure axially aligned with the magnet and extending from the base around the permanent magnet. The pole piece directs magnetic field lines into the resonance zone, moving the resonance zone further from the face of the magnet. Additional permanent magnets or magnet arrays may be utilized to control field contours on a local scale. Rather than a permeable material, the sidewall structure may be composed of an annular cylindrical magnetic material having a polarity opposite that of the permanent magnet, creating convex regions in the resonance zone. An annular disk-shaped recurve section at the end of the sidewall structure forms magnetic mirrors keeping the plasma off the pole piece. A recurve section composed of magnetic material having a radial polarity forms convex regions and/or magnetic mirrors within the resonance zone.

  1. Batch fabrication of precision miniature permanent magnets

    DOE Patents [OSTI]

    Christenson, Todd R.; Garino, Terry J.; Venturini, Eugene L.

    2002-01-01

    A new class of processes for fabrication of precision miniature rare earth permanent magnets is disclosed. Such magnets typically have sizes in the range 0.1 to 10 millimeters, and dimensional tolerances as small as one micron. Very large magnetic fields can be produced by such magnets, lending to their potential application in MEMS and related electromechanical applications, and in miniature millimeter-wave vacuum tubes. This abstract contains simplifications, and is supplied only for purposes of searching, not to limit or alter the scope or meaning of any claims herein.

  2. Permanent magnet design for high-speed superconducting bearings

    DOE Patents [OSTI]

    Hull, J.R.; Uherka, K.L.; Abdoud, R.G.

    1996-09-10

    A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure is disclosed. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing. 9 figs.

  3. Permanent magnet design for high-speed superconducting bearings

    DOE Patents [OSTI]

    Hull, John R.; Uherka, Kenneth L.; Abdoud, Robert G.

    1996-01-01

    A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing.

  4. 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.

  5. Permanent-magnet-less synchronous reluctance system

    DOE Patents [OSTI]

    Hsu, John S

    2012-09-11

    A permanent magnet-less synchronous system includes a stator that generates a magnetic revolving field when sourced by an alternating current. An uncluttered rotor is disposed within the magnetic revolving field and spaced apart from the stator to form an air gap relative to an axis of rotation. The rotor includes a plurality of rotor pole stacks having an inner periphery biased by single polarity of a north-pole field and a south-pole field, respectively. The outer periphery of each of the rotor pole stacks are biased by an alternating polarity.

  6. Permanent-magnet switched-flux machine

    DOE Patents [OSTI]

    Trzynadlowski, Andrzej M.; Qin, Ling

    2011-06-14

    A permanent-magnet switched-flux (PMSF) device has an outer rotor mounted to a shaft about a central axis extending axially through the PMSF device. First and second pluralities of permanent-magnets (PMs) are respectively mounted in first and second circles, radially outwardly in first and second transverse planes extending from first and second sections of the central axis adjacent to an inner surface of the outer rotor. An inner stator is coupled to the shaft and has i) a stator core having a core axis co-axial with the central axis; and ii) first and second pluralities of stator poles mounted in first and second circles, radially outwardly from the stator core axis in the first and second transverse planes. The first and second pluralities of PMs each include PMs of alternating polarity.

  7. Permanent-magnet switched-flux machine

    DOE Patents [OSTI]

    Trzynadlowski, Andrzej M.; Qin, Ling

    2010-01-12

    A permanent-magnet switched-flux (PMSF) device has a ferromagnetic outer stator mounted to a shaft about a central axis extending axially through the PMSF device. Pluralities of top and bottom stator poles are respectively mounted in first and second circles, radially outwardly in first and second transverse planes extending from first and second sections of the central axis adjacent to an inner surface of the ferromagnetic outer stator. A ferromagnetic inner rotor is coupled to the shaft and has i) a rotor core having a core axis co-axial with the central axis; and ii) first and second discs having respective outer edges with first and second pluralities of permanent magnets (PMs) mounted in first and second circles, radially outwardly from the rotor core axis in the first and second transverse planes. The first and second pluralities of PMs each include PMs of alternating polarity.

  8. Permanent-magnet switched-flux machine

    DOE Patents [OSTI]

    Trzynadlowski, Andrzej M.; Qin, Ling

    2012-02-21

    A permanent-magnet switched-flux (PMSF) device has an outer rotor mounted to a shaft about a central axis extending axially through the PMSF device. First and second pluralities of permanent-magnets (PMs) are respectively mounted in first and second circles, radially outwardly in first and second transverse planes extending from first and second sections of the central axis adjacent to an inner surface of the outer rotor. An inner stator is coupled to the shaft and has i) a stator core having a core axis co-axial with the central axis; and ii) first and second pluralities of stator poles mounted in first and second circles, radially outwardly from the stator core axis in the first and second transverse planes. The first and second pluralities of PMs each include PMs of alternating polarity.

  9. Novel Flux Coupling Machine without Permanent Magnets | Department of

    Broader source: Energy.gov (indexed) [DOE]

    Energy 11 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation ape005_hsu_2011_o.pdf (325.23 KB) More Documents & Publications Novel Flux Coupling Machine without Permanent Magnets A New Class of Switched Reluctance Motors without Permanent Magnets A New Class of Switched Reluctance Motors without Permanent Magnets

  10. Novel Flux Coupling Machine without Permanent Magnets - U Machine...

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

    Magnets - U Machine Novel Flux Coupling Machine without Permanent Magnets - U Machine 2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer ...

  11. Effect of Side Permanent Magnets for Reluctance Interior Permanent Magnet Reluctance Machines

    SciTech Connect (OSTI)

    Hsu, John S; Lee, Seong T; Wiles, Randy H; Coomer, Chester; Lowe, Kirk T

    2007-01-01

    A traditional electric machine uses two dimensional magnetic flux paths in its rotor. This paper presents the development work on the utilization of the third dimension of a rotor. As an example, the air gap flux of a radial gap interior permanent magnet motor can be significantly enhanced by additional permanent magnets (PM) mounted at the sides of the rotor. A prototype motor built with this concept provided higher efficiency and required a shorter stator core length for the same power output as the Toyota/Prius traction drive motor.

  12. Strong permanent magnet-assisted electromagnetic undulator

    DOE Patents [OSTI]

    Halbach, Klaus

    1988-01-01

    This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles.

  13. Adjustable permanent magnet assembly for NMR and MRI

    DOE Patents [OSTI]

    Pines, Alexander; Paulsen, Jeffrey; Bouchard, Louis S; Blumich, Bernhard

    2013-10-29

    System and methods for designing and using single-sided magnet assemblies for magnetic resonance imaging (MRI) are disclosed. The single-sided magnet assemblies can include an array of permanent magnets disposed at selected positions. At least one of the permanent magnets can be configured to rotate about an axis of rotation in the range of at least +/-10 degrees and can include a magnetization having a vector component perpendicular to the axis of rotation. The single-sided magnet assemblies can further include a magnet frame that is configured to hold the permanent magnets in place while allowing the at least one of the permanent magnets to rotate about the axis of rotation.

  14. 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.

  15. Method and apparatus for assembling a permanent magnet pole assembly

    DOE Patents [OSTI]

    Carl, Jr., Ralph James; Bagepalli, Bharat Sampathkumaran; Jansen, Patrick Lee; Dawson, Richard Nils; Qu, Ronghai; Avanesov, Mikhail Avramovich

    2009-08-11

    A pole assembly for a rotor, the pole assembly includes a permanent magnet pole including at least one permanent magnet block, a plurality of laminations including a pole cap mechanically coupled to the pole, and a plurality of laminations including a base plate mechanically coupled to the pole.

  16. Permanent-Magnet Adjustable-Speed Motors John S . Hsu (Htsui...

    Office of Scientific and Technical Information (OSTI)

    Nature and Measurements of Torque Ripple of Permanent-Magnet Adjustable-Speed Motors John ... motors can be classified into four types depending on the nature of their origin. ...

  17. Permanent Magnet Development for Automotive Traction Motors | Department of

    Broader source: Energy.gov (indexed) [DOE]

    Energy 1 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation ape015_anderson_2011_o.pdf (1.01 MB) More Documents & Publications Permanent Magnet Development for Automotive Traction Motors Permanent Magnet Development for Automotive Traction Motors Vehicle Technologies Office Merit Review 2015: Development of Radically Enhanced alnico Magnets (DREaM) for Traction Drive

  18. Method and apparatus for assembling permanent magnet rotors

    DOE Patents [OSTI]

    Hsu, John S.; Adams, Donald J.

    1999-01-01

    A permanent magnet assembly (22) for assembly in large permanent magnet (PM) motors and generators includes a two-piece carrier (23, 24) that can be slid into a slot (13) in the rotor (10) and then secured in place using a set screw (37). The invention also provides an auxiliary carrier device (50) with guide rails (51) that line up with the teeth (12) of the rotor, so that a permanent magnet assembly (22) can be pushed first into a slot (13), and then down the slot (13) to its proper location. An auxiliary tool (50) is provided to move the permanent magnet assembly (22) into position in the slot (13) before it is secured in place. Methods of assembling and disassembling the magnet assemblies (22) in the rotor (10) are also disclosed.

  19. Method and apparatus for assembling permanent magnet rotors

    DOE Patents [OSTI]

    Hsu, J.S.; Adams, D.J.

    1999-06-22

    A permanent magnet assembly for assembly in large permanent magnet motors and generators includes a two-piece carrier that can be slid into a slot in the rotor and then secured in place using a set screw. The invention also provides an auxiliary carrier device with guide rails that line up with the teeth of the rotor, so that a permanent magnet assembly can be pushed first into a slot, and then down the slot to its proper location. An auxiliary tool is provided to move the permanent magnet assembly into position in the slot before it is secured in place. Methods of assembling and disassembling the magnet assemblies in the rotor are also disclosed. 2 figs.

  20. Permanent magnet with MgB{sub 2} bulk superconductor

    SciTech Connect (OSTI)

    Yamamoto, Akiyasu; Ishihara, Atsushi; Tomita, Masaru; Kishio, Kohji

    2014-07-21

    Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging. The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2 K. Herein, we demonstrate that 40-K-class metallic HTS magnesium diboride (MgB{sub 2}) makes an excellent permanent bulk magnet, maintaining 3 T at 20 K for 1 week with an extremely high stability (<0.1 ppm/h). The magnetic field trapped in this magnet is uniformly distributed, as for single-crystalline neodymium-iron-boron. Magnetic hysteresis loop of the MgB{sub 2} permanent bulk magnet was determined. Because MgB{sub 2} is a simple-binary-line compound that does not contain rare-earth metals, polycrystalline bulk material can be industrially fabricated at low cost and with high yield to serve as strong magnets that are compatible with conventional compact cryocoolers, making MgB{sub 2} bulks promising for the next generation of Tesla-class permanent-magnet applications.

  1. Permanent-magnet-less machine having an enclosed air gap

    DOE Patents [OSTI]

    Hsu, John S.

    2013-03-05

    A permanent magnet-less, brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by an alternating current. An uncluttered rotor disposed within the magnetic rotating field is spaced apart from the stator to form an air gap relative to an axis of rotation. A stationary excitation core spaced apart from the uncluttered rotor by an axial air gap and a radial air gap substantially encloses the stationary excitation core. Some permanent magnet-less, brushless synchronous systems include stator core gaps to reduce axial flux flow. Some permanent magnet-less, brushless synchronous systems include an uncluttered rotor coupled to outer laminations. The quadrature-axis inductance may be increased in some synchronous systems. Some synchronous systems convert energy such as mechanical energy into electrical energy (e.g., a generator); other synchronous systems may convert any form of energy into mechanical energy (e.g., a motor).

  2. Permanent-magnet-less machine having an enclosed air gap

    DOE Patents [OSTI]

    Hsu, John S.

    2012-02-07

    A permanent magnet-less, brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by an alternating current. An uncluttered rotor disposed within the magnetic rotating field is spaced apart from the stator to form an air gap relative to an axis of rotation. A stationary excitation core spaced apart from the uncluttered rotor by an axial air gap and a radial air gap substantially encloses the stationary excitation core. Some permanent magnet-less, brushless synchronous systems include stator core gaps to reduce axial flux flow. Some permanent magnet-less, brushless synchronous systems include an uncluttered rotor coupled to outer laminations. The quadrature-axis inductance may be increased in some synchronous systems. Some synchronous systems convert energy such as mechanical energy into electrical energy (e.g., a generator); other synchronous systems may convert any form of energy into mechanical energy (e.g., a motor).

  3. Method of making bonded or sintered permanent magnets

    DOE Patents [OSTI]

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

    1993-08-31

    An isotropic permanent magnet is made by mixing a thermally responsive, low viscosity binder and atomized rare earth-transition metal (e.g., iron) alloy powder having a carbon-bearing (e.g., graphite) layer thereon that facilitates wetting and bonding of the powder particles by the binder. Prior to mixing with the binder, the atomized alloy powder may be sized or classified to provide a particular particle size fraction having a grain size within a given relatively narrow range. A selected particle size fraction is mixed with the binder and the mixture is molded to a desired complex magnet shape. A molded isotropic permanent magnet is thereby formed. A sintered isotropic permanent magnet can be formed by removing the binder from the molded mixture and thereafter sintering to full density.

  4. Method of making bonded or sintered permanent magnets

    DOE Patents [OSTI]

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

    1995-11-28

    An isotropic permanent magnet is made by mixing a thermally responsive, low viscosity binder and atomized rare earth-transition metal (e.g., iron) alloy powder having a carbon-bearing (e.g., graphite) layer thereon that facilitates wetting and bonding of the powder particles by the binder. Prior to mixing with the binder, the atomized alloy powder may be sized or classified to provide a particular particle size fraction having a grain size within a given relatively narrow range. A selected particle size fraction is mixed with the binder and the mixture is molded to a desired complex magnet shape. A molded isotropic permanent magnet is thereby formed. A sintered isotropic permanent magnet can be formed by removing the binder from the molded mixture and thereafter sintering to full density.

  5. Method of making bonded or sintered permanent magnets

    DOE Patents [OSTI]

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

    1995-11-28

    An isotropic permanent magnet is made by mixing a thermally responsive, low viscosity binder and atomized rare earth-transition metal (e.g., iron) alloy powder having a carbon-bearing (e.g., graphite) layer thereon that facilitates wetting and bonding of the powder particles by the binder. Prior to mixing with the binder, the atomized alloy powder may be sized or classified to provide a particular particle size fraction having a grain size within a given relatively narrow range. A selected particle size fraction is mixed with the binder and the mixture is molded to a desired complex magnet shape. A molded isotropic permanent magnet is thereby formed. A sintered isotropic permanent magnet can be formed by removing the binder from the molded mixture and thereafter sintering to full density. 14 figs.

  6. System Cost Analysis for an Interior Permanent Magnet Motor

    SciTech Connect (OSTI)

    Peter Campbell

    2008-08-01

    The objective of this program is to provide an assessment of the cost structure for an interior permanent magnet ('IPM') motor which is designed to meet the 2010 FreedomCAR specification. The program is to evaluate the range of viable permanent magnet materials for an IPM motor, including sintered and bonded grades of rare earth magnets. The study considers the benefits of key processing steps, alternative magnet shapes and their assembly methods into the rotor (including magnetization), and any mechanical stress or temperature limits. The motor's costs are estimated for an annual production quantity of 200,000 units, and are broken out into such major components as magnetic raw materials, processing and manufacturing. But this is essentially a feasibility study of the motor's electromagnetic design, and is not intended to include mechanical or thermal studies as would be done to work up a selected design for production.

  7. High-Energy Composite Permanent Magnets: High-Energy Permanent Magnets for Hybrid Vehicles and Alternative Energy

    SciTech Connect (OSTI)

    2010-02-15

    Broad Funding Opportunity Announcement Project: The University of Delaware is developing permanent magnets that contain less rare earth material and produce twice the energy of the strongest rare earth magnets currently available. The University of Delaware is creating these magnets by mixing existing permanent magnet materials with those that are more abundant, like iron. Both materials are first prepared in the form of nanoparticles via techniques ranging from wet chemistry to ball milling. After that, the nanoparticles must be assembled in a 3-D array and consolidated at low temperatures to form a magnet. With small size particles and good contact between these two materials, the best qualities of each allow for the development of exceptionally strong composite magnets.

  8. Hybrid-secondary uncluttered permanent magnet machine and method

    DOE Patents [OSTI]

    Hsu, John S.

    2005-12-20

    An electric machine (40) has a stator (43), a permanent magnet rotor (38) with permanent magnets (39) and a magnetic coupling uncluttered rotor (46) for inducing a slip energy current in secondary coils (47). A dc flux can be produced in the uncluttered rotor when the secondary coils are fed with dc currents. The magnetic coupling uncluttered rotor (46) has magnetic brushes (A, B, C, D) which couple flux in through the rotor (46) to the secondary coils (47c, 47d) without inducing a current in the rotor (46) and without coupling a stator rotational energy component to the secondary coils (47c, 47d). The machine can be operated as a motor or a generator in multi-phase or single-phase embodiments and is applicable to the hybrid electric vehicle. A method of providing a slip energy controller is also disclosed.

  9. Permanent-magnet flowmeter having improved output-terminal means

    DOE Patents [OSTI]

    August, C.; Myers, H.J.

    1981-10-26

    Disclosed is an improved permanent magnet flowmeter capable of withstanding bending stresses in the direction of induced emf signals. The flowmeter includes a unique terminal arrangement integrally formed with the flowmeter by trepanning opposing wall sections of the flowmeter body. The terminal arrangement provides increased flowmeter sensitivity by increasing the strength of the induced emf signals.

  10. Permanent magnet flowmeter having improved output terminal means

    DOE Patents [OSTI]

    August, Charles; Myers, Harry J.

    1984-01-01

    Disclosed is an improved permanent magnet flowmeter capable of withstanding bending stresses in the direction of induced emf signals. The flowmeter includes a unique terminal arrangement integrally formed with the flowmeter by trepanning opposing wall sections of the flowmeter body. The terminal arrangement provides increased flowmeter sensitivity by increasing the strength of the induced emf signals.

  11. Brushed permanent magnet DC MLC motor operation in an external magnetic field

    SciTech Connect (OSTI)

    Yun, J.; St Aubin, J.; Rathee, S.; Fallone, B. G.

    2010-05-15

    Purpose: Linac-MR systems for real-time image-guided radiotherapy will utilize the multileaf collimators (MLCs) to perform conformal radiotherapy and tumor tracking. The MLCs would be exposed to the external fringe magnetic fields of the linac-MR hybrid systems. Therefore, an experimental investigation of the effect of an external magnetic field on the brushed permanent magnet DC motors used in some MLC systems was performed. Methods: The changes in motor speed and current were measured for varying external magnetic field strengths up to 2000 G generated by an EEV electromagnet. These changes in motor characteristics were measured for three orientations of the motor in the external magnetic field, mimicking changes in motor orientations due to installation and/or collimator rotations. In addition, the functionality of the associated magnetic motor encoder was tested. The tested motors are used with the Varian 120 leaf Millennium MLC (Maxon Motor half leaf and full leaf motors) and the Varian 52 leaf MKII MLC (MicroMo Electronics leaf motor) including a carriage motor (MicroMo Electronics). Results: In most cases, the magnetic encoder of the motors failed prior to any damage to the gearbox or the permanent magnet motor itself. This sets an upper limit of the external magnetic field strength on the motor function. The measured limits of the external magnetic fields were found to vary by the motor type. The leaf motor used with a Varian 52 leaf MKII MLC system tolerated up to 450{+-}10 G. The carriage motor tolerated up to 2000{+-}10 G field. The motors used with the Varian 120 leaf Millennium MLC system were found to tolerate a maximum of 600{+-}10 G. Conclusions: The current Varian MLC system motors can be used for real-time image-guided radiotherapy coupled to a linac-MR system, provided the fringe magnetic fields at their locations are below the determined tolerance levels. With the fringe magnetic fields of linac-MR systems expected to be larger than the

  12. Perspectives on Permanent Magnetic Materials for Energy Conversion and Power Generation

    SciTech Connect (OSTI)

    Lewis, LH; Jimenez-Villacorta, F

    2012-07-18

    Permanent magnet development has historically been driven by the need to supply larger magnetic energy in ever smaller volumes for incorporation in an enormous variety of applications that include consumer products, transportation components, military hardware, and clean energy technologies such as wind turbine generators and hybrid vehicle regenerative motors. Since the 1960s, the so-called rare-earth "supermagnets," composed of iron, cobalt, and rare-earth elements such as Nd, Pr, and Sm, have accounted for the majority of global sales of high-energy-product permanent magnets for advanced applications. In rare-earth magnets, the transition-metal components provide high magnetization, and the rare-earth components contribute a very large magnetocrystalline anisotropy that donates high resistance to demagnetization. However, at the end of 2009, geopolitical influences created a worldwide strategic shortage of rare-earth elements that may be addressed, among other actions, through the development of rare-earth-free magnetic materials harnessing sources of magnetic anisotropy other than that provided by the rare-earth components. Materials engineering at the micron scale, nanoscale, and Angstrom scales, accompanied by improvements in the understanding and characterization of nanoscale magnetic phenomena, is anticipated to result in new types of permanent magnetic materials with superior performance. DOI: 10.1007/s11661-012-1278-2 (C) The Minerals, Metals & Materials Society and ASM International 2012

  13. Robust ferromagnetism in the compressed permanent magnet Sm2Co17...

    Office of Scientific and Technical Information (OSTI)

    Robust ferromagnetism in the compressed permanent magnet Sm2Co17 Citation Details In-Document Search Title: Robust ferromagnetism in the compressed permanent magnet Sm2Co17 ...

  14. Method for forming permanent magnets with different polarities for use in microelectromechanical devices

    DOE Patents [OSTI]

    Roesler, Alexander W.; Christenson, Todd R.

    2007-04-24

    Methods are provided for forming a plurality of permanent magnets with two different north-south magnetic pole alignments for use in microelectromechanical (MEM) devices. These methods are based on initially magnetizing the permanent magnets all in the same direction, and then utilizing a combination of heating and a magnetic field to switch the polarity of a portion of the permanent magnets while not switching the remaining permanent magnets. The permanent magnets, in some instances, can all have the same rare-earth composition (e.g. NdFeB) or can be formed of two different rare-earth materials (e.g. NdFeB and SmCo). The methods can be used to form a plurality of permanent magnets side-by-side on or within a substrate with an alternating polarity, or to form a two-dimensional array of permanent magnets in which the polarity of every other row of the array is alternated.

  15. Performance of An Adjustable Strength Permanent Magnet Quadrupole

    SciTech Connect (OSTI)

    Gottschalk, S.C.; DeHart, T.E.; Kangas, K.W.; Spencer, C.M.; Volk, J.T.; /Fermilab

    2006-03-01

    An adjustable strength permanent magnet quadrupole suitable for use in Next Linear Collider has been built and tested. The pole length is 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) is 68.7 Tesla. This paper describes measurements of strength, magnetic CL and field quality made using an air bearing rotating coil system. The magnetic CL stability during -20% strength adjustment proposed for beam based alignment was < 0.2 microns. Strength hysteresis was negligible. Thermal expansion of quadrupole and measurement parts caused a repeatable and easily compensated change in the vertical magnetic CL. Calibration procedures as well as CL measurements made over a wider tuning range of 100% to 20% in strength useful for a wide range of applications will be described. The impact of eddy currents in the steel poles on the magnetic field during strength adjustments will be reported.

  16. Dynamic high pressure process for fabricating superconducting and permanent magnetic materials

    DOE Patents [OSTI]

    Nellis, William J.; Geballe, Theodore H.; Maple, M. Brian

    1988-01-01

    Shock wave formation of thin layers of materials with improved superconducting and permanent magnetic properties and improved microstructures.

  17. Disc rotors with permanent magnets for brushless DC motor

    DOE Patents [OSTI]

    Hawsey, Robert A.; Bailey, J. Milton

    1992-01-01

    A brushless dc permanent magnet motor drives an autonomous underwater vehe. In one embodiment, the motor comprises four substantially flat stators in stacked relationship, with pairs of the stators axially spaced, each of the stators comprising a tape-wound stator coil, and first and second substantially flat rotors disposed between the spaced pairs of stators. Each of the rotors includes an annular array of permanent magnets embedded therein. A first shaft is connected to the first rotor and a second, concentric shaft is connected to the second rotor, and a drive unit causes rotation of the two shafts in opposite directions. The second shaft comprises a hollow tube having a central bore in which the first shaft is disposed. Two different sets of bearings support the first and second shafts. In another embodiment, the motor comprises two ironless stators and pairs of rotors mounted on opposite sides of the stators and driven by counterrotating shafts.

  18. Permanent magnet machine with windings having strand transposition

    DOE Patents [OSTI]

    Qu, Ronghai; Jansen, Patrick Lee

    2009-04-21

    This document discusses, among other things, a stator with transposition between the windings or coils. The coils are free from transposition to increase the fill factor of the stator slots. The transposition at the end connections between an inner coil and an outer coil provide transposition to reduce circulating current loss. The increased fill factor reduces further current losses. Such a stator is used in a dual rotor, permanent magnet machine, for example, in a compressor pump, wind turbine gearbox, wind turbine rotor.

  19. A clip-on Zeeman slower using toroidal permanent magnets

    SciTech Connect (OSTI)

    Krzyzewski, S. P.; Akin, T. G.; Dahal, Parshuram; Abraham, E. R. I.

    2014-10-15

    We present the design of a zero-crossing Zeeman slower for {sup 85}Rb using rings of flexible permanent magnets. The design is inexpensive, requires no power or cooling, and can be easily attached and removed for vacuum maintenance. We show theoretically that such a design can reproduce a magnetic field profile of a standard zero-crossing Zeeman slower. Experimental measurements of a prototype and comparisons to theoretical simulations demonstrate the feasibility of the design and point toward future improvements. Simulations show an atom flux similar to other Zeeman slowers.

  20. A strong permanent magnet-assisted electromagnetic undulator

    DOE Patents [OSTI]

    Halbach, K.

    1987-01-30

    This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles. 4 figs.

  1. "Permanent Magnet Generator-like AC Current Drive for Torroidal Fusion

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

    Devices" Inventor..--.. Ali Zolfaghari | Princeton Plasma Physics Lab Permanent Magnet Generator-like AC Current Drive for Torroidal Fusion Devices" Inventor..--.. Ali Zolfaghari The scheme is similar to a permanent magnet generator. Large strong permanent magnets placed toroidally on the outside of a torus are used to create a magnetic flux that links the center of the torus through an iron (ferromagnetic material) spherical shell connected to an iron center column core. Pulsing

  2. A compact permanent magnet cyclotrino for accelerator mass spectrometry

    SciTech Connect (OSTI)

    Young, A.T.; Clark, D.J.; Kunkel, W.B.; Leung, K.N.; Li, C.Y.

    1995-02-01

    The authors describe the development of a new instrument for the detection of trace amounts of rare isotopes, a Cyclotron Mass Spectrometer (CMS). A compact low energy cyclotron optimized for high mass resolution has been designed and has been fabricated. The instrument has high sensitivity and is designed to measure carbon-14 at abundances of < 10{sup {minus}12}. A novel feature of the instrument is the use of permanent magnets to energize the iron poles of the cyclotron. The instrument uses axial injection, employing a spiral inflector. The instrument has been assembled and preliminary measurements of the magnetic field show that it has a uniformity on the order of 2 parts in 10{sup 4}.

  3. Vehicle Technologies Office Merit Review 2014: Permanent Magnet Development for Automotive Traction Motors

    Broader source: Energy.gov [DOE]

    Presentation given by Ames Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about permanent magnet development...

  4. Hybrid permanent magnet quadrupoles for the Recycler Ring at Fermilab

    SciTech Connect (OSTI)

    Brown, B.C.; Pruss, S.M.; Foster, G.W.; Glass, H.D.; Harding, D.J.; Jackson, G.R.; May, M.R.; Nicol, T.H.; Ostiguy, J.-F.; Schlabach, R.; Volk, J.T.

    1997-10-01

    Hybrid Permanent Magnet Quadrupoles are used in several applications for the Fermilab Recycler Ring and associated beam transfer lines. Most of these magnets use a 0.6096 m long iron shell and provide integrated gradients up to 1.4 T-m/m with an iron pole tip radius of 41.6 mm. A 58.4 mm pole radius design is also required. Bricks of 25. 4 mm thick strontium ferrite supply the flux to the back of the pole to produce the desired gradients (0.6 to 2.75 T/m). For temperature compensation, Ni-Fe alloy strips are interspersed between ferrite bricks to subtract flux in a temperature dependent fashion. Adjustments of the permeance of each pole using iron between the pole and the flux return shell permits the matching of pole potentials. Magnetic potentials of the poles are adjusted to the desired value to achieve the prescribed strength and field uniformity based on rotating coil harmonic measurements. Procurement, fabrication, pole potential adjustment, and measured fields will be reported.

  5. Innovative Sensors for Pipeline Crawlers: Rotating Permanent Magnet Inspection

    SciTech Connect (OSTI)

    J. Bruce Nestleroth; Richard J. Davis; Stephanie Flamberg

    2006-09-30

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they may encounter. To facilitate inspection of these ''unpiggable'' pipelines, recent inspection development efforts have focused on a new generation of powered inspection platforms that are able to crawl slowly inside a pipeline and can maneuver past the physical barriers that limit internal inspection applicability, such as bore restrictions, low product flow rate, and low pressure. The first step in this research was to review existing inspection technologies for applicability and compatibility with crawler systems. Most existing inspection technologies, including magnetic flux leakage and ultrasonic methods, had significant implementation limitations including mass, physical size, inspection energy coupling requirements and technology maturity. The remote field technique was the most promising but power consumption was high and anomaly signals were low requiring sensitive detectors and electronics. After reviewing each inspection technology, it was decided to investigate the potential for a new inspection method. The new inspection method takes advantage of advances in permanent magnet strength, along with their wide availability and low cost. Called rotating permanent magnet inspection (RPMI), this patent pending technology employs pairs of permanent magnets rotating around the central axis of a cylinder to induce high current densities in the material under inspection. Anomalies and wall thickness variations are detected with an array of sensors that measure local changes in the magnetic field produced by the induced current flowing in the material. This inspection method is an alternative to the common concentric coil remote field technique that induces low-frequency eddy

  6. High energy product permanent magnet having improved intrinsic coercivity and method of making same

    DOE Patents [OSTI]

    Ramesh, Ramamoorthy; Thomas, Gareth

    1990-01-01

    A high energy rare earth-ferromagnetic metal permanent magnet is disclosed which is characterized by improved intrinsic coercivity and is made by forming a particulate mixture of a permanent magnet alloy comprising one or more rare earth elements and one or more ferromagnetic metals and forming a second particulate mixture of a sintering alloy consisting essentially of 92-98 wt. % of one or more rare earth elements selected from the class consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures of two or more of such rare earth elements, and 2-8 wt. % of one or more alloying metals selected from the class consisting of Al, Nb, Zr, V, Ta, Mo, and mixtures of two or more of such metals. The permanent magnet alloy particles and sintering aid alloy are mixed together and magnetically oriented by immersing the mixture in an axially aligned magnetic field while cold pressing the mixture. The compressed mixture is then sintered at a temperature above the melting point of the sintering aid and below the melting point of the permanent magnet alloy to thereby coat the particle surfaces of the permanent magnetic alloy particles with the sintering aid while inhibiting migration of the rare earth element in the sintering aid into the permanent magnet alloy particles to thereby raise the intrinsic coercivity of the permanent magnet alloy without substantially lowering the high energy of the permanent magnet alloy.

  7. Processing and Protection of Rare Earth Permanent Magnet Particulate for Bonded Magnet Applications

    SciTech Connect (OSTI)

    Peter Kelly Sokolowski

    2007-12-01

    Rapid solidification of novel mixed rare earth-iron-boron, MRE{sub 2}Fe{sub 14}B (MRE = Nd, Y, Dy; currently), magnet alloys via high pressure gas atomization (HPGA) have produced similar properties and structures as closely related alloys produced by melt spinning (MS) at low wheel speeds. Recent additions of titanium carbide and zirconium to the permanent magnet (PM) alloy design in HPGA powder (using He atomization gas) have made it possible to achieve highly refined microstructures with magnetic properties approaching melt spun particulate at cooling rates of 10{sup 5}-10{sup 6}K/s. By producing HPGA powders with the desirable qualities of melt spun ribbon, the need for crushing ribbon was eliminated in bonded magnet fabrication. The spherical geometry of HPGA powders is more ideal for processing of bonded permanent magnets since higher loading fractions can be obtained during compression and injection molding. This increased volume loading of spherical PM powder can be predicted to yield a higher maximum energy product (BH){sub max} for bonded magnets in high performance applications. Passivation of RE-containing powder is warranted for the large-scale manufacturing of bonded magnets in applications with increased temperature and exposure to humidity. Irreversible magnetic losses due to oxidation and corrosion of particulates is a known drawback of RE-Fe-B based alloys during further processing, e.g. injection molding, as well as during use as a bonded magnet. To counteract these effects, a modified gas atomization chamber allowed for a novel approach to in situ passivation of solidified particle surfaces through injection of a reactive gas, nitrogen trifluoride (NF{sub 3}). The ability to control surface chemistry during atomization processing of fine spherical RE-Fe-B powders produced advantages over current processing methodologies. In particular, the capability to coat particles while 'in flight' may eliminate the need for post atomization treatment

  8. Cerium-Based Magnets: Novel High Energy Permanent Magnet Without Critical Elements

    SciTech Connect (OSTI)

    2012-01-01

    REACT Project: Ames Laboratory will develop a new class of permanent magnets based on the more commonly available element cerium for use in both EVs and renewable power generators. Cerium is 4 times more abundant and significantly less expensive than the rare earth element neodymium, which is frequently used in today’s most powerful magnets. Ames Laboratory will combine other metal elements with cerium to create a new magnet that can remain stable at the high temperatures typically found in electric motors. This new magnetic material will ultimately be demonstrated in a prototype electric motor, representing a cost-effective and efficient alternative to neodymium-based motors.

  9. Rare-Earth-Free Nanostructure Magnets: Rare-Earth-Free Permanent Magnets for Electric Vehicle Motors and Wind Turbine Generators: Hexagonal Symmetry Based Materials Systems Mn-Bi and M-type Hexaferrite

    SciTech Connect (OSTI)

    2012-01-01

    REACT Project: The University of Alabama is developing new iron- and manganese-based composite materials for use in the electric motors of EVs and renewable power generators that will demonstrate magnetic properties superior to todays best rare-earth-based magnets. Rare earths are difficult and expensive to refine. EVs and renewable power generators typically use rare earths to make their electric motors smaller and more powerful. The University of Alabama has the potential to improve upon the performance of current state-of-the-art rare-earth-based magnets using low-cost and more abundant materials such as manganese and iron. The ultimate goal of this project is to demonstrate improved performance in a full-size prototype magnet at reduced cost.

  10. 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.

  11. Permanent Magnet Synchronous Condenser with Solid State Excitation: Preprint

    SciTech Connect (OSTI)

    Hsu, P.; Muljadi, E.; Wu, Z.; Gao, W.

    2015-04-07

    A typical synchronous condenser (SC) consists of a free-spinning, wound-field synchronous generator and a field excitation controller. In this paper, we propose an SC that employs a permanent magnet synchronous generator (PMSG) instead of a wound-field machine. PMSGs have the advantages of higher efficiency and reliability. In the proposed configuration, the reactive power control is achieved by a voltage converter controller connected in series to the PMSG. The controller varies the phase voltage of the PMSG and creates the same effect on the reactive power flow as that of an over- or underexcited wound-field machine. The controller’s output voltage magnitude controls the amount of the reactive power produced by the SC. The phase of the controller’s output is kept within a small variation from the grid voltage phase. This small phase variation is introduced so that a small amount of power can be drawn from the grid into the controller to maintain its DC bus voltage. Because the output voltage of the controller is only a fraction of the line voltage, its VA rating is only a fraction of the rating of the PMSG. The proposed scheme is shown to be effective by computer simulations.

  12. The influence of microstructure on magnetic properties of nanocrystalline Fe-Pt-Nb-B permanent magnet ribbons

    SciTech Connect (OSTI)

    Randrianantoandro, N.; Greneche, J. M.; Crisan, A. D.; Crisan, O.; Marcin, J.; Kovac, J.; Hanko, J.; Skorvanek, I.; Svec, P.; Chrobak, A.

    2010-11-15

    A FePt-based hard-magnetic nanocomposite of exchange spring type was prepared by isothermal annealing of melt-spun Fe{sub 52}Pt{sub 28}Nb{sub 2}B{sub 18} (atomic percent) ribbons. The relationship between microstructure and magnetic properties was investigated by qualitative and quantitative structural analysis based on the x-ray diffraction, transmission electron microscopy, and {sup 57}Fe Moessbauer spectrometry on one hand and the superconducting quantum interference device magnetometry on the other hand. The microstructure consists of L1{sub 0}-FePt hard-magnetic grains (15-45 nm in diameter) dispersed in a soft magnetic medium composed by A1 FePt, Fe{sub 2}B, and boron-rich (FeB)PtNb remainder phase. The ribbons annealed at 700 deg. C for 1 h exhibit promising hard-magnetic properties at room temperature: M{sub r}/M{sub s}=0.69; H{sub c}=820 kA/m and (BH){sub max}=70 kJ/m{sup 3}. Strong exchange coupling between hard and soft magnetic phases was demonstrated by a smooth demagnetizing curve and positive {delta}M-peak in the Henkel plot. The magnetic properties measured from 5 to 750 K reveals that the hard characteristics remains rather stable up to 550 K, indicating a good prospect for the use of these permanent magnets in a wide temperature range.

  13. Current Drive for Plasma Via Vertically-Structured Permanent Magnet System.

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

    | Princeton Plasma Physics Lab Current Drive for Plasma Via Vertically-Structured Permanent Magnet System. This invention uses the rotatoin of permanent magnets to generate a plasma current with toroidal fusion confinement devices. This particular device strategically places two rings of magnets above and below the ferromagnetic core in order to maximize both the efficiency and plasma current. No.: M-872 Inventor(s): Ali Zolfaghari

  14. Radiofrequency hydrogen ion source with permanent magnets providing axial magnetic field

    SciTech Connect (OSTI)

    Oikawa, Kohei Saito, Yuta; Komizunai, Shota; Takahashi, Kazunori; Ando, Akira

    2014-02-15

    Uniform axial magnetic field of about 70 G is applied to a radiofrequency (rf) hydrogen ion source by arrays of permanent magnets. The plasma density and electron temperature downstream of the source and near the magnetic filter are compared with those in the previously described ion source, where the axial field has been applied by two solenoids. The source is operated at ∼350 kHz and above 10 kW rf power with a field-effect-transistor-based invertor power supply in 1.5 Pa hydrogen. The results show that the plasma density of ∼10{sup 19} m{sup −3} near the source exit and ∼10{sup 18} m{sup −3} near the magnetic filter can be obtained, which are higher than those with the solenoids.

  15. Prospects for Non-Rare Earth Permanent Magnets for Traction Motors and Generators

    SciTech Connect (OSTI)

    Kramer, Matthew; McCallum, Kendall; Anderson, Iver; Constantinides, Steven

    2012-06-29

    With the advent of high-flux density permanent magnets based on rare earth elements such as neodymium (Nd) in the 1980s, permanent magnet-based electric machines had a clear performance and cost advantage over induction machines when weight and size were factors such as in hybrid electric vehicles and wind turbines. However, the advantages of the permanent magnet-based electric machines may be overshadowed by supply constraints and high prices of their key constituents, rare earth elements, which have seen nearly a 10-fold increase in price in the last 5 years and the imposition of export limits by the major producing country, China, since 2010. We outline the challenges, prospects, and pitfalls for several potential alloys that could replace Nd-based permanent magnets with more abundant and less strategically important elements.

  16. High speed internal permanent magnet machine and method of manufacturing the same

    DOE Patents [OSTI]

    Alexander, James Pellegrino; EL-Refaie, Ayman Mohamed Fawzi; Lokhandwalla, Murtuza; Shah, Manoj Ramprasad; VanDam, Jeremy Daniel

    2011-09-13

    An internal permanent magnet (IPM) machine is provided. The IPM machine includes a stator assembly and a stator core. The stator core also includes multiple stator teeth. The stator assembly is further configured with stator windings to generate a magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface defining a cavity. The IPM machine also includes a rotor assembly and a rotor core. The rotor core is disposed inside the cavity and configured to rotate about the longitudinal axis. The rotor assembly further includes a shaft. The shaft further includes multiple protrusions alternately arranged relative to multiple bottom structures provided on the shaft. The rotor assembly also includes multiple stacks of laminations disposed on the protrusions and dovetailed circumferentially around the shaft. The rotor assembly further includes multiple permanent magnets for generating a magnetic field, which interacts with the stator magnetic field to produce torque. The permanent magnets are disposed between the stacks. The rotor assembly also includes multiple bottom wedges disposed on the bottom structures of the shaft and configured to hold the multiple stacks and the multiple permanent magnets.

  17. The use of a permanent magnet for water content measurements ofwood chips

    SciTech Connect (OSTI)

    Barale, P.J.; Fong, C.G.; Green, M.A.; Luft, P.A.; McInturff,A.D.; Reimer, J.A.; Yahnke, M.

    2001-09-20

    The Lawrence Berkeley National Laboratory has developed a device that measures the water content of wood chips, pulp and brown stock for the paper industry. This device employs a permanent magnet as the central part of a NMR measurement system. This report describes the magnet and the NMR measurement system. The results of water content measurements in wood chips in a magnetic field of 0.47 T are presented.

  18. Method for providing slip energy control in permanent magnet electrical machines

    DOE Patents [OSTI]

    Hsu, John S.

    2006-11-14

    An electric machine (40) has a stator (43), a permanent magnet rotor (38) with permanent magnets (39) and a magnetic coupling uncluttered rotor (46) for inducing a slip energy current in secondary coils (47). A dc flux can be produced in the uncluttered rotor when the secondary coils are fed with dc currents. The magnetic coupling uncluttered rotor (46) has magnetic brushes (A, B, C, D) which couple flux in through the rotor (46) to the secondary coils (47c, 47d) without inducing a current in the rotor (46) and without coupling a stator rotational energy component to the secondary coils (47c, 47d). The machine can be operated as a motor or a generator in multi-phase or single-phase embodiments and is applicable to the hybrid electric vehicle. A method of providing a slip energy controller is also disclosed.

  19. Dual-rotor, radial-flux, toroidally-wound, permanent-magnet machine

    DOE Patents [OSTI]

    Qu, Ronghai; Lipo, Thomas A.

    2005-08-02

    The present invention provides a novel dual-rotor, radial-flux, toroidally-wound, permanent-magnet machine. The present invention improves electrical machine torque density and efficiency. At least one concentric surface-mounted permanent magnet dual-rotor is located inside and outside of a torus-shaped stator with back-to-back windings, respectively. The machine substantially improves machine efficiency by reducing the end windings and boosts the torque density by at least doubling the air gap and optimizing the machine aspect ratio.

  20. Method and apparatus for sensorless operation of brushless permanent magnet motors

    DOE Patents [OSTI]

    Sriram, T.V.

    1998-04-14

    A sensorless method and apparatus for providing commutation timing signals for a brushless permanent magnet motor extracts the third harmonic back-emf of a three-phase stator winding and independently cyclically integrates the positive and negative half-cycles thereof and compares the results to a reference level associated with a desired commutation angle. 23 figs.

  1. Method and apparatus for sensorless operation of brushless permanent magnet motors

    DOE Patents [OSTI]

    Sriram, Tillasthanam V.

    1998-01-01

    A sensorless method and apparatus for providing commutation timing signals for a brushless permanent magnet motor extracts the third harmonic back-emf of a three-phase stator winding and independently cyclically integrates the positive and negative half-cycles thereof and compares the results to a reference level associated with a desired commutation angle.

  2. Perfect 2-d quadrupole fields from permanent magnets

    SciTech Connect (OSTI)

    Lee, E.P.; Vella, M.

    1996-04-01

    Consider the 13-beam channel array shown in Figure 1. It is asserted that, under mathematically ideal assumptions, a pure quadrupole field is centered in each of the 13 beam channel boxes. An identical quadrupole field (for {bar H}, not {bar B}) is also centered in each of the 4 boxes containing 4 magnetic wedges located near the center of the system. An iron yoke ({mu} = {infinity}) with the displayed zig-zag shape provides a boundary condition (H{sub {parallel}} = 0) that makes the 13 channels equivalent to a portion of an infinite array. A similar array can be readily drawn for any number of beams. The quadrupole gradient in the beam channels is B{prime} = M{sub o}/2b, where M{sub o} is the remnant field of the magnetic wedges, and the channel diameter (wedge-to-wedge) is 2b. Note that a unit cell of the array, containing one beam, has diameter 2{radical}2 b (viewed from 45{degree} tilt) so its area is 8 b{sup 2}. A significant advantage of this design over those using dipolar blocks is the large fraction of cross section devoted to beam channels (50% vs 25%). Application to a heavy ion fusion driver is discussed.

  3. Permanent Magnet Skew Quadrupoles for the Low Emittance LER Lattice of PEP-II

    SciTech Connect (OSTI)

    Decker, F.-J.; Anderson, S.; Kharakh, D.; Sullivan, M.; /SLAC

    2011-07-05

    The vertical emittance of the low energy ring (LER) in the PEP-II B-Factory was reduced by using skew quadrupoles consisting of permanent magnet material. The advantages over electric quadrupoles or rotating existing normal quadrupoles are discussed. To assure a high field quality, a Biot-Savart calculation was used to cancel the natural 12-pole component by using different size poles over a few layers. A magnetic measurement confirmed the high quality of the magnets. After installation and adjusting the original electric 12 skew and 16 normal quadrupoles the emittance contribution from the region close to the interaction point, which was the biggest part in the original design, was considerably reduced. To strengthen the vertical behavior of the LER beam, a low emittance lattice was developed. It lowered the original vertical design emittance from 0.54 nm-rad to 0.034 nm-rad. In order to achieve this, additional skew quadrupoles were required to bring the coupling correction out of the arcs and closer to the detector solenoid in the straight (Fig. 1). It is important, together with low vertical dispersion, that the low vertical emittance is not coupled into the horizontal, which is what we get if the coupling correction continues into the arcs. Further details of the lattice work is described in another paper; here we concentrate on the development of the permanent skew (PSK) quadrupole solution. Besides the permanent magnets there are two other possibilities, using electric magnets or rotating normal quadrupoles. Electric magnets would have required much more additional equipment like magnets stands, power supply, and new vacuum chamber sections. Rotating existing quadrupoles was also not feasible since they are mostly mounted together with a bending magnet on the same support girder.

  4. 16,000-rpm Interior Permanent Magnet Reluctance Machine with Brushless Field Excitation

    SciTech Connect (OSTI)

    Hsu, J.S.; Burress, T.A.; Lee, S.T.; Wiles, R.H.; Coomer, C.L.; McKeever, J.W.; Adams, D.J.

    2007-10-31

    The reluctance interior permanent magnet (RIPM) motor is currently used by many leading auto manufacturers for hybrid vehicles. The power density for this type of motor is high compared with that of induction motors and switched reluctance motors. The primary drawback of the RIPM motor is the permanent magnet (PM) because during high-speed operation, the fixed PM produces a huge back electromotive force (emf) that must be reduced before the current will pass through the stator windings. This reduction in back-emf is accomplished with a significant direct-axis (d-axis) demagnetization current, which opposes the PM's flux to reduce the flux seen by the stator wires. This may lower the power factor and efficiency of the motor and raise the requirement on the alternate current (ac) power supply; consequently, bigger inverter switching components, thicker motor winding conductors, and heavier cables are required. The direct current (dc) link capacitor is also affected when it must accommodate heavier harmonic currents. It is commonly agreed that, for synchronous machines, the power factor can be optimized by varying the field excitation to minimize the current. The field produced by the PM is fixed and cannot be adjusted. What can be adjusted is reactive current to the d-axis of the stator winding, which consumes reactive power but does not always help to improve the power factor. The objective of this project is to avoid the primary drawbacks of the RIPM motor by introducing brushless field excitation (BFE). This offers both high torque per ampere (A) per core length at low speed by using flux, which is enhanced by increasing current to a fixed excitation coil, and flux, which is weakened at high speed by reducing current to the excitation coil. If field weakening is used, the dc/dc boost converter used in a conventional RIPM motor may be eliminated to reduce system costs. However, BFE supports a drive system with a dc/dc boost converter, because it can further extend

  5. A high performance inverter-fed drive system of an interior permanent magnet synchronous machine

    SciTech Connect (OSTI)

    Bose, B.K.

    1987-01-01

    A high performance fully operational four-quadrant control scheme of an interior permanent magnet synchronous machine is described. The machine operates smoothly with full performance in constant-torque region as well as in flux-weakening constant-power region in both the directions of motion. The transition between constant-torque region and constant-power region is very smooth at all conditions of operation. The control in constant-torque region is based on vector or field-oriented technique with the direct-axis aligned to the total stator flux, whereas the constant-power region control is implemented by orientation of torque angle of the impressed square-wave voltage through the feedforward vector rotator. The control system is implemented digitally using distributed microcomputer system and all the essential feedback signals, such as torque, flux, etc., are estimated with precision. The control has been described with an outer torque control loop primarily for traction type applications, but speed and position control loops can be easily added to extend its application to other industrial drives. A 70 hp drive system using a Neodymium-Iron-Boron PM machine and transistor PWM inverter has been designed and extensively tested in laboratory on a dynamometer, and performances are found to be excellent.

  6. Spoke permanent magnet machine with reduced torque ripple and method of manufacturing thereof

    DOE Patents [OSTI]

    Reddy, Patel Bhageerath; EL-Refaie, Ayman Mohamed Fawzi; Huh, Kum-Kang; Alexander, James Pellegrino

    2016-03-15

    An internal permanent magnet machine includes a rotor assembly having a shaft comprising a plurality of protrusions extending radially outward from a main shaft body and being formed circumferentially about the main shaft body and along an axial length of the main shaft body. A plurality of stacks of laminations are arranged circumferentially about the shaft to receive the plurality of protrusions therein, with each stack of laminations including a plurality of lamination groups arranged axially along a length of the shaft and with permanent magnets being disposed between the stacks of laminations. Each of the laminations includes a shaft protrusion cut formed therein to receive a respective shaft protrusion and, for each of the stacks of laminations, the shaft protrusion cuts formed in the laminations of a respective lamination group are angularly offset from the shaft protrusion cuts formed in the laminations in an adjacent lamination group.

  7. Dynamic high pressure process for fabricating superconducting and permanent magnetic materials

    DOE Patents [OSTI]

    Nellis, William J.; Geballe, Theodore H.; Maple, M. Brian

    1990-01-01

    Shock wave formation of thin layers of materials with improved superconducting and permanent magnetic properties and improved microstructures. The material fabrication system includes a sandwiched structure including a powder material placed between two solid members to enable explosive shock consolidation. The two solid members are precooled to about 80.degree.-100.degree. K. to reduce the residual temperatures attained as a result of the shock wave treatment, and thereby increase the quench rate of the consolidated powder.

  8. Dynamic high pressure process for fabricating superconducting and permanent magnetic materials

    DOE Patents [OSTI]

    Nellis, W.J.; Geballe, T.H.; Maple, M.B.

    1990-03-13

    Shock wave formation of thin layers of materials with improved superconducting and permanent magnetic properties and improved microstructures is disclosed. The material fabrication system includes a sandwiched structure including a powder material placed between two solid members to enable explosive shock consolidation. The two solid members are precooled to about 80--100 K to reduce the residual temperatures attained as a result of the shock wave treatment, and thereby increase the quench rate of the consolidated powder. 9 figs.

  9. Wheel-type magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1983-10-11

    The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load. 7 figs.

  10. Wheel-type magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1982-01-20

    The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load.

  11. Wheel-type magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, John A.

    1983-01-01

    The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load.

  12. Iron-Nickel-Based SuperMagnets: Multiscale Development of L10 Materials for Rare Earth-Free Permanent Magnets

    SciTech Connect (OSTI)

    2012-01-01

    REACT Project: Northeastern University will develop bulk quantities of rare-earth-free permanent magnets with an iron-nickel crystal structure for use in the electric motors of renewable power generators and EVs. These materials could offer magnetic properties that are equivalent to today’s best commercial magnets, but with a significant cost reduction and diminished environmental impact. This iron-nickel crystal structure, which is only found naturally in meteorites and developed over billions of years in space, will be artificially synthesized by the Northeastern University team. Its material structure will be replicated with the assistance of alloying elements introduced to help it achieve superior magnetic properties. The ultimate goal of this project is to demonstrate bulk magnetic properties that can be fabricated at the industrial scale.

  13. A Permanent-Magnet Microwave Ion Source for a Compact High-Yield Neutron Generator

    SciTech Connect (OSTI)

    Waldmann, Ole; Ludewigt, Bernhard

    2010-10-11

    We present recent work on the development of a microwave ion source that will be used in a high-yield compact neutron generator for active interrogation applications. The sealed tube generator will be capable of producing high neutron yields, 5x1011 n/s for D-T and ~;;1x1010 n/s for D-D reactions, while remaining transportable. We constructed a microwave ion source (2.45 GHz) with permanent magnets to provide the magnetic field strength of 87.5 mT necessary for satisfying the electron cyclotron resonance (ECR) condition. Microwave ion sources can produce high extracted beam currents at the low gas pressures required for sealed tube operation and at lower power levels than previously used RF-driven ion sources. A 100 mA deuterium/tritium beam will be extracted through a large slit (60x6 mm2) to spread the beam power over a larger target area. This paper describes the design of the permanent-magnet microwave ion source and discusses the impact of the magnetic field design on the source performance. The required equivalent proton beam current density of 40 mA/cm2 was extracted at a moderate microwave power of 400 W with an optimized magnetic field.

  14. Electro-mechanical energy conversion system having a permanent magnet machine with stator, resonant transfer link and energy converter controls

    DOE Patents [OSTI]

    Skeist, S. Merrill; Baker, Richard H.

    2006-01-10

    An electro-mechanical energy conversion system coupled between an energy source and an energy load comprising an energy converter device including a permanent magnet induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer to control the flow of power or energy through the permanent magnetic induction machine.

  15. Strategic coating of NdFeB magnets with Dy to improve the coercivity of permanent magnets

    SciTech Connect (OSTI)

    Ucar, Huseyin; Parker, David S.; Nlebedim, I. C.; McCallum, R. W.; McCall, S. K.; Parans Paranthaman, M.

    2015-12-25

    Here, we present a method, supported by theoretical analysis, for optimizing the usage of the critical rare earth element dysprosium in Nd2Fe14B (NdFeB)-based permanent magnets. In this method, we use Dy selectively in locations such as magnet edges and faces, where demagnetization factors are most significant, rather than uniformly throughout the bulk sample. A 200 nm thick Dy film was sputtered onto commercial N-38, NdFeB magnets with a thickness of 3 mm and post-annealed at temperatures from 600 - 700 C. Magnets displayed enhanced coercivities after post-annealing. Furthermore, our experimental results indicate as large as a 5 percent increase in the energy product of NdFeB magnets, achieved for a total Dy weight percentage of 0.06 percent, much less than that used in commercial grade Dy-NdFeB magnets. Finally, by assuming all Dy diffused into NdFeB magnets, the improvement in energy product corresponds to a saving of over 1% Dy (critical element). Magnets manufactured using this technique will therefore be higher performing and significantly less expensive than those made presently.

  16. Strategic coating of NdFeB magnets with Dy to improve the coercivity of permanent magnets

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

    Ucar, Huseyin; Parker, David S.; Nlebedim, I. C.; McCallum, R. W.; McCall, S. K.; Parans Paranthaman, M.

    2015-12-25

    Here, we present a method, supported by theoretical analysis, for optimizing the usage of the critical rare earth element dysprosium in Nd2Fe14B (NdFeB)-based permanent magnets. In this method, we use Dy selectively in locations such as magnet edges and faces, where demagnetization factors are most significant, rather than uniformly throughout the bulk sample. A 200 nm thick Dy film was sputtered onto commercial N-38, NdFeB magnets with a thickness of 3 mm and post-annealed at temperatures from 600 - 700 C. Magnets displayed enhanced coercivities after post-annealing. Furthermore, our experimental results indicate as large as a 5 percent increase inmore » the energy product of NdFeB magnets, achieved for a total Dy weight percentage of 0.06 percent, much less than that used in commercial grade Dy-NdFeB magnets. Finally, by assuming all Dy diffused into NdFeB magnets, the improvement in energy product corresponds to a saving of over 1% Dy (critical element). Magnets manufactured using this technique will therefore be higher performing and significantly less expensive than those made presently.« less

  17. Modeling the Value Recovery of Rare Earth Permanent Magnets at End-of-Life

    SciTech Connect (OSTI)

    Cong, Liang; Jin, Hongyue; Fitsos, Pete; McIntyre, Timothy; Yih, Yuehwern; Zhao, Fu; Sutherland, John W.

    2015-05-21

    Permanent magnets containing rare earth elements (REEs) such as Dysprosium and Neodymium offer an advantage over non-REE containing magnets (e.g. ferrite or AlNiCo) in terms of power relative to size. However, REE availability has varied significantly in recent years leading to volatility in the cost of rare earth permanent magnets (REPMs). The supply of REEs can be increased by recycling consumer products and industrial machinery that contain REPMs at product end-of-life (EOL). This paper discusses the REE recovery process for EOL products. The optimal dismantling of products is examined with an emphasis placed on obtaining used REPMs. The challenge of collecting, managing, transporting, and processing used products is addressed through the development of a cost model for REPM recovery. This model is used to investigate several EOL strategies for recovering REPMs. Sensitivity analysis is conducted to identify the key factors that influence value recovery economics. A hard disk drive serves as a case study for model demonstration.

  18. Modeling the Value Recovery of Rare Earth Permanent Magnets at End-of-Life

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

    Cong, Liang; Jin, Hongyue; Fitsos, Pete; McIntyre, Timothy; Yih, Yuehwern; Zhao, Fu; Sutherland, John W.

    2015-05-21

    Permanent magnets containing rare earth elements (REEs) such as Dysprosium and Neodymium offer an advantage over non-REE containing magnets (e.g. ferrite or AlNiCo) in terms of power relative to size. However, REE availability has varied significantly in recent years leading to volatility in the cost of rare earth permanent magnets (REPMs). The supply of REEs can be increased by recycling consumer products and industrial machinery that contain REPMs at product end-of-life (EOL). This paper discusses the REE recovery process for EOL products. The optimal dismantling of products is examined with an emphasis placed on obtaining used REPMs. The challenge ofmore » collecting, managing, transporting, and processing used products is addressed through the development of a cost model for REPM recovery. This model is used to investigate several EOL strategies for recovering REPMs. Sensitivity analysis is conducted to identify the key factors that influence value recovery economics. A hard disk drive serves as a case study for model demonstration.« less

  19. Modeling the value recovery of rare earth permanent magnets at end-of-life

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

    Cong, Liang; Jin, Hongyue; Fitsos, Pete; McIntyre, Timothy; Yih, Yuehwern; Zhao, Fu; Sutherland, John W.

    2015-01-01

    Permanent magnets containing rare earth elements (REEs) such as Dysprosium and Neodymium offer an advantage over non-REE containing magnets (e.g., ferrite and AlNiCo) in terms of power relative to size. However, REE availability has varied significantly in recent years leading to volatility in the cost of rare earth permanent magnets (REPMs). The supply of REEs can be increased by recycling consumer products and industrial machinery that contain REPMs at product end-of-life (EOL). This paper discusses the REE recovery process for EOL products. The optimal dismantling of products is examined with an emphasis placed on obtaining used REPMs. The challenge ofmore » collecting, managing, transporting, and processing used products is addressed through the development of a cost model for REPM recovery. This model is used to investigate several EOL strategies for recovering REPMs. Sensitivity analysis is conducted to identify the key factors that influence value recovery economics. A hard disk drive serves as a case study for model demonstration.« less

  20. Modeling the value recovery of rare earth permanent magnets at end-of-life

    SciTech Connect (OSTI)

    Cong, Liang; Jin, Hongyue; Fitsos, Pete; McIntyre, Timothy; Yih, Yuehwern; Zhao, Fu; Sutherland, John W.

    2015-01-01

    Permanent magnets containing rare earth elements (REEs) such as Dysprosium and Neodymium offer an advantage over non-REE containing magnets (e.g., ferrite and AlNiCo) in terms of power relative to size. However, REE availability has varied significantly in recent years leading to volatility in the cost of rare earth permanent magnets (REPMs). The supply of REEs can be increased by recycling consumer products and industrial machinery that contain REPMs at product end-of-life (EOL). This paper discusses the REE recovery process for EOL products. The optimal dismantling of products is examined with an emphasis placed on obtaining used REPMs. The challenge of collecting, managing, transporting, and processing used products is addressed through the development of a cost model for REPM recovery. This model is used to investigate several EOL strategies for recovering REPMs. Sensitivity analysis is conducted to identify the key factors that influence value recovery economics. A hard disk drive serves as a case study for model demonstration.

  1. Method and system for controlling start of a permanent magnet machine

    DOE Patents [OSTI]

    Walters, James E.; Krefta, Ronald John

    2003-10-28

    Method and system for controlling a permanent magnet machine are provided. The method provides a sensor assembly for sensing rotor sector position relative to a plurality of angular sectors. The method further provides a sensor for sensing angular increments in rotor position. The method allows starting the machine in a brushless direct current mode of operation using a calculated initial rotor position based on an initial angular sector position information from the sensor assembly. Upon determining a transition from the initial angular sector to the next angular sector, the method allows switching to a sinusoidal mode of operation using rotor position based on rotor position information from the incremental sensor.

  2. Direct thrust measurement of a permanent magnet helicon double layer thruster

    SciTech Connect (OSTI)

    Takahashi, K.; Lafleur, T.; Charles, C.; Alexander, P.; Boswell, R. W.; Perren, M.; Laine, R.; Pottinger, S.; Lappas, V.; Harle, T.; Lamprou, D.

    2011-04-04

    Direct thrust measurements of a permanent magnet helicon double layer thruster have been made using a pendulum thrust balance and a high sensitivity laser displacement sensor. At the low pressures used (0.08 Pa) an ion beam is detected downstream of the thruster exit, and a maximum thrust force of about 3 mN is measured for argon with an rf input power of about 700 W. The measured thrust is proportional to the upstream plasma density and is in good agreement with the theoretical thrust based on the maximum upstream electron pressure.

  3. Method and system for controlling a permanent magnet machine during fault conditions

    DOE Patents [OSTI]

    Krefta, Ronald John; Walters, James E.; Gunawan, Fani S.

    2004-05-25

    Method and system for controlling a permanent magnet machine driven by an inverter is provided. The method allows for monitoring a signal indicative of a fault condition. The method further allows for generating during the fault condition a respective signal configured to maintain a field weakening current even though electrical power from an energy source is absent during said fault condition. The level of the maintained field-weakening current enables the machine to operate in a safe mode so that the inverter is protected from excess voltage.

  4. Cluster expansion modeling and Monte Carlo simulation of alnico 5–7 permanent magnets

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

    Nguyen, Manh Cuong; Zhao, Xin; Wang, Cai -Zhuang; Ho, Kai -Ming

    2015-03-05

    The concerns about the supply and resource of rare earth (RE) metals have generated a lot of interests in searching for high performance RE-free permanent magnets. Alnico alloys are traditional non-RE permanent magnets and have received much attention recently due their good performance at high temperature. In this paper, we develop an accurate and efficient cluster expansion energy model for alnico 5–7. Monte Carlo simulations using the cluster expansion method are performed to investigate the structure of alnico 5–7 at atomistic and nano scales. The alnico 5–7 master alloy is found to decompose into FeCo-rich and NiAl-rich phases at lowmore » temperature. The boundary between these two phases is quite sharp (~2 nm) for a wide range of temperature. The compositions of the main constituents in these two phases become higher when the temperature gets lower. Both FeCo-rich and NiAl-rich phases are in B2 ordering with Fe and Al on α-site and Ni and Co on β-site. The degree of order of the NiAl-rich phase is much higher than that of the FeCo-rich phase. In addition, a small magnetic moment is also observed in NiAl-rich phase but the moment reduces as the temperature is lowered, implying that the magnetic properties of alnico 5–7 could be improved by lowering annealing temperature to diminish the magnetism in NiAl-rich phase. Furthermore, the results from our Monte Carlo simulations are consistent with available experimental results.« less

  5. Cluster expansion modeling and Monte Carlo simulation of alnico 5–7 permanent magnets

    SciTech Connect (OSTI)

    Nguyen, Manh Cuong; Zhao, Xin; Wang, Cai -Zhuang; Ho, Kai -Ming

    2015-03-05

    The concerns about the supply and resource of rare earth (RE) metals have generated a lot of interests in searching for high performance RE-free permanent magnets. Alnico alloys are traditional non-RE permanent magnets and have received much attention recently due their good performance at high temperature. In this paper, we develop an accurate and efficient cluster expansion energy model for alnico 5–7. Monte Carlo simulations using the cluster expansion method are performed to investigate the structure of alnico 5–7 at atomistic and nano scales. The alnico 5–7 master alloy is found to decompose into FeCo-rich and NiAl-rich phases at low temperature. The boundary between these two phases is quite sharp (~2 nm) for a wide range of temperature. The compositions of the main constituents in these two phases become higher when the temperature gets lower. Both FeCo-rich and NiAl-rich phases are in B2 ordering with Fe and Al on α-site and Ni and Co on β-site. The degree of order of the NiAl-rich phase is much higher than that of the FeCo-rich phase. In addition, a small magnetic moment is also observed in NiAl-rich phase but the moment reduces as the temperature is lowered, implying that the magnetic properties of alnico 5–7 could be improved by lowering annealing temperature to diminish the magnetism in NiAl-rich phase. Furthermore, the results from our Monte Carlo simulations are consistent with available experimental results.

  6. Cluster expansion modeling and Monte Carlo simulation of alnico 57 permanent magnets

    SciTech Connect (OSTI)

    Nguyen, Manh Cuong; Zhao, Xin; Wang, Cai -Zhuang; Ho, Kai -Ming

    2015-03-05

    The concerns about the supply and resource of rare earth (RE) metals have generated a lot of interests in searching for high performance RE-free permanent magnets. Alnico alloys are traditional non-RE permanent magnets and have received much attention recently due their good performance at high temperature. In this paper, we develop an accurate and efficient cluster expansion energy model for alnico 57. Monte Carlo simulations using the cluster expansion method are performed to investigate the structure of alnico 57 at atomistic and nano scales. The alnico 57 master alloy is found to decompose into FeCo-rich and NiAl-rich phases at low temperature. The boundary between these two phases is quite sharp (~2 nm) for a wide range of temperature. The compositions of the main constituents in these two phases become higher when the temperature gets lower. Both FeCo-rich and NiAl-rich phases are in B2 ordering with Fe and Al on ?-site and Ni and Co on ?-site. The degree of order of the NiAl-rich phase is much higher than that of the FeCo-rich phase. In addition, a small magnetic moment is also observed in NiAl-rich phase but the moment reduces as the temperature is lowered, implying that the magnetic properties of alnico 57 could be improved by lowering annealing temperature to diminish the magnetism in NiAl-rich phase. Furthermore, the results from our Monte Carlo simulations are consistent with available experimental results.

  7. High-Energy Permanent Magnets for Hybrid Vehicles and Alternative Energy Uses

    SciTech Connect (OSTI)

    Hadjipanayis, George C.; McCallum, William R.; Sellmyer, David J.; Harris, Vincent; Carpenter, Everett E.; Liu, Jinfang

    2013-12-17

    The report summarizes research undertaken by a multidisciplinary team aimed at the development of the next generation high-energy permanent magnets. The principal approach was relied on bottom-up fabrication of anisotropic nanocomposite magnets. Our efforts resulted in further development of the theoretical concept and fabrication principles for the nanocomposites and in synthesis of a range of rare-earth-based hard magnetic nanoparticles. Even though we did not make a breakthrough in the assembly of these hard magnetic particles with separately prepared Fe(Co) nanoparticles and did not obtain a compact nanocomposite magnet, our performed research will help to direct the future efforts, in particular, towards nano-assembly via coating, when the two phases which made the nanocomposite are first organized in core-shell-structured particles. Two other approaches were to synthesize (discover) new materials for the traditional singe-material magnets and the nanocomposite magnets. Integrated theoretical and experimental efforts lead to a significant advance in nanocluster synthesis technique and yielded novel rare-earth-free nanostructured and nanocomposite materials. Examination of fifteen R-Fe-X alloy systems (R = rare earth), which have not been explored earlier due to various synthesis difficulties reveal several new ferromagnetic compounds. The research has made major progress in bottom-up manufacturing of rare-earth-containing nanocomposite magnets with superior energy density and open new directions in development of higher-energy-density magnets that do not contain rare earths. The advance in the scientific knowledge and technology made in the course of the project has been reported in 50 peer-reviewed journal articles and numerous presentations at scientific meetings.

  8. Manganese-Aluminum-Based Magnets: Nanocrystalline t-MnAI Permanent Magnets

    SciTech Connect (OSTI)

    2012-01-01

    REACT Project: Dartmouth is developing specialized alloys with magnetic properties superior to the rare earths used in todays best magnets. EVs and renewable power generators typically use rare earths to turn the axles in their electric motors due to the magnetic strength of these minerals. However, rare earths are difficult and expensive to refine. Dartmouth will swap rare earths for a manganese-aluminum alloy that could demonstrate better performance and cost significantly less. The ultimate goal of this project is to develop an easily scalable process that enables the widespread use of low-cost and abundant materials for the magnets used in EVs and renewable power generators.

  9. NMR system and method having a permanent magnet providing a rotating magnetic field

    DOE Patents [OSTI]

    Schlueter, Ross D [Berkeley, CA; Budinger, Thomas F [Berkeley, CA

    2009-05-19

    Disclosed herein are systems and methods for generating a rotating magnetic field. The rotating magnetic field can be used to obtain rotating-field NMR spectra, such as magic angle spinning spectra, without having to physically rotate the sample. This result allows magic angle spinning NMR to be conducted on biological samples such as live animals, including humans.

  10. Investigation of coercivity mechanism in hot deformed Nd-Fe-B permanent magnets by small-angle neutron scattering

    SciTech Connect (OSTI)

    Yano, M., E-mail: masao-yano-aa@mail.toyota.co.jp; Manabe, A.; Shoji, T.; Kato, A. [Advanced Material Engineering Division, Toyota Motor Corporation, Susono 410-1193 (Japan); Ono, K. [High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan); Harada, M. [Toyota Central R and D Labs, Inc., Aichi 480-1192 (Japan); Kohlbrecher, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

    2014-05-07

    The magnetic reversal behaviors of single domain sized Nd-Fe-B permanent magnets, with and without isolation between the Nd{sub 2}Fe{sub 14}B grains, was clarified using small-angle neutron scattering (SANS). The SANS patterns obtained arose from changes in the magnetic domains and were analyzed using the TeubnerStray model, a phenomenological correlation length model, to quantify the periodicity and morphology of the magnetic domains. The results indicated that the magnetic reversal evolved with the magnetic domains that had similar sized grains. The grain isolation enabled us to realize the reversals of single domains.

  11. A novel permanently magnetised high gradient magnetic filter using assisted capture for fine particles

    SciTech Connect (OSTI)

    Watson, J.H.P.

    1995-02-01

    This paper describes the structure and properties of a novel permanently magnetised magnetic filter for fine friable radioactive material. Previously a filter was described and tested. This filter was designed so that the holes in the filter are left open as capture proceeds which means the pressure drop builds up only slowly. This filter is not suitable for friable composite particles which can be broken by mechanical forces. The structure of magnetic part of the second filter has been changed so as to strongly capture particles composed of fine particles weakly bound together which tend to break when captured. This uses a principle of assisted-capture in which coarse particles aid the capture of the fine fragments. The technique has the unfortunate consequence that the pressure drop across the filter rises faster as capture capture proceeds than the filter described previously. These filters have the following characteristics: (1) No external magnet is required. (2) No external power is required. (3) Small is size and portable. (4) Easily interchangeable. (5) Can be cleaned without demagnetising.

  12. Carbide/nitride grain refined rare earth-iron-boron permanent magnet and method of making

    DOE Patents [OSTI]

    McCallum, R. William; Branagan, Daniel J.

    1996-01-23

    A method of making a permanent magnet wherein 1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and 2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries. The crystallized particulates are consolidated at an elevated temperature to form a shape. During elevated temperature consolidation, the primary and secondary precipitates act to pin the grain boundaries and minimize deleterious grain growth that is harmful to magnetic properties.

  13. Carbide/nitride grain refined rare earth-iron-boron permanent magnet and method of making

    DOE Patents [OSTI]

    McCallum, R.W.; Branagan, D.J.

    1996-01-23

    A method of making a permanent magnet is disclosed wherein (1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and (2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries. The crystallized particulates are consolidated at an elevated temperature to form a shape. During elevated temperature consolidation, the primary and secondary precipitates act to pin the grain boundaries and minimize deleterious grain growth that is harmful to magnetic properties. 33 figs.

  14. Development of a Permanent-Magnet Microwave Ion Source for a Sealed-Tube Neutron Generator

    SciTech Connect (OSTI)

    Waldmann, Ole; Ludewigt, Bernhard

    2011-03-31

    A microwave ion source has been designed and constructed for use with a sealed-tube, high-yield neutron generator. When operated with a tritium-deuterium gas mixture the generator will be capable of producing 5*1011 n/s in non-proliferation applications. Microwave ion sources are well suited for such a device because they can produce high extracted beam currents with a high atomic fraction at low gas pressures of 0.2-0.3 Pa required for sealed tube operation. The magnetic field strength for achieving electron cyclotron resonance (ECR) condition, 87.5 mT at 2.45 GHz microwave frequency, was generated and shaped with permanent magnets surrounding the plasma chamber and a ferromagnetic plasma electrode. This approach resulted in a compact ion source that matches the neutron generator requirements. The needed proton-equivalent extracted beam current density of 40 mA/cm^2 was obtained at moderate microwave power levels of 400 W. Results on magnetic field design, pressure dependency and atomic fraction measured for different wall materials are presented.

  15. Development of a Direct Drive Permanent Magnet Generator for Small Wind Turbines

    SciTech Connect (OSTI)

    Chertok, Allan; Hablanian, David; McTaggart, Paul; DOE Project Officer - Keith Bennett

    2004-11-16

    In this program, TIAX performed the conceptual design and analysis of an innovative, modular, direct-drive permanent magnet generator (PMG) for use in small wind turbines that range in power rating from 25 kW to 100 kW. TIAX adapted an approach that has been successfully demonstrated in high volume consumer products such as direct-drive washing machines and portable generators. An electromagnetic model was created and the modular PMG design was compared to an illustrative non-modular design. The resulting projections show that the modular design can achieve significant reductions in size, weight, and manufacturing cost without compromising efficiency. Reducing generator size and weight can also lower the size and weight of other wind turbine components and hence their manufacturing cost.

  16. Demonstration of variable speed permanent magnet generator at small, low-head hydro site

    SciTech Connect (OSTI)

    Brown Kinloch, David

    2015-12-18

    Small hydro developers face a limited set of bad choices when choosing a generator for a small low-head hydro site. Direct drive synchronous generators are expensive and technically complex to install. Simpler induction generators are higher speed, requiring a speed increaser, which results in inefficiencies and maintenance problems. In addition, both induction and synchronous generators turn at a fixed speed, causing the turbine to run off its peak efficiency curve whenever the available head is different than the designed optimum head.The solution to these problems is the variable speed Permanent Magnet Generators (PMG). At the Weisenberger Mill in Midway, KY, a variable speed Permanent Magnet Generator has been installed and demonstrated. This new PMG system replaced an existing induction generator that had a HTD belt drive speed increaser system. Data was taken from the old generator before it was removed and compared to data collected after the PMG system was installed. The new variable speed PMG system is calculated to produce over 96% more energy than the old induction generator system during an average year. This significant increase was primarily due to the PMG generator operating at the correct speed at the maximum head, and the ability for the PMG generator to reduce its speed to lower optimum speeds as the stream flow increased and the net head decreased.This demonstration showed the importance of being able to adjust the speed of fixed blade turbines. All fixed blade turbines with varying net heads could achieve higher efficiencies if the speed can be matched to the optimum speed as the head changes. In addition, this demonstration showed that there are many potential efficiencies that could be realized with variable speed technology at hydro sites where mismatched turbine and generator speeds result in lower power output, even at maximum head. Funding for this project came from the US Dept. of Energy, through Award Number DE-EE0005429.

  17. Read/write head having a GMR sensor biased by permanent magnets located between the GMR and the pole shields

    DOE Patents [OSTI]

    Yuan, Samuel W.; Rottmayer, Robert Earl; Carey, Matthew J.

    1999-01-01

    A compact read/write head having a biased giant magnetoresistive sensor. Permanent magnet films are placed adjacent to the giant magnetoresistive sensor operating in the current-perpendicular-to the-plane (Cpp) mode and spaced with respect to the sensor by conducting films. These permanent magnet films provide a magnetic bias. The bias field is substantial and fairly uniform across sensor height. Biasing of the giant magnetoresistive sensor provides distinguishable response to the rising and falling edges of a recorded pulse on an adjacent recording medium, improves the linearity of the response, and helps to reduce noise. This read/write head is much simpler to fabricate and pattern and provides an enhanced uniformity of the bias field throughout the sensor.

  18. Voltage Regulation Using a Permanent Magnet Synchronous Generator with a Series Compensator: Preprint

    SciTech Connect (OSTI)

    Hsu, Ping; Wu, Ziping; Muljadi, Eduard; Gao, Wenzhong

    2015-08-24

    A wind power plant (WPP) is often operated at unity power factor, and the utility host where the WPP connects prefers to regulate the voltage. Although this may not be an issue in a stiff grid, the connection to a weak grid can be a problematic. This paper explores the advantages of having voltage regulation capability via reactive power control. Another issue in wind power generation is that not all turbines are able to control their reactive power due to technical reasons or contractual obligations. A synchronous condenser (SC) using a permanent magnet synchronous generator (PMSG) is proposed to provide necessary reactive power for regulating voltage at a weak grid connection. A PMSG has the advantage of higher efficiency and reliability. Because of its lack of a field winding, a PMSG is typically controlled by a full-power converter, which can be costly. In the proposed system, the reactive power of the SC is controlled by a serially connected compensator operating in a closed-loop configuration. The compensator also damps the PMSG’s tendency to oscillate. The compensator’s VA rating is only a fraction of the rating of the SC and the PMSG. In this initial investigation, the proposed scheme is shown to be effective by computer simulations.

  19. Control of Two Permanent Magnet Machines Using a Five-Leg Inverter for Automotive Applications

    SciTech Connect (OSTI)

    Su, Gui-Jia; Tang, Lixin; Huang, Xianghui

    2006-01-01

    This paper presents digital control schemes for control of two permanent magnet (PM) machines in an integrated traction and air-conditioning compressor drive system for automotive applications. The integrated drive system employs a five-leg inverter to power a three-phase traction PM motor and a two-phase compressor PM motor by tying the common terminal of the two-phase motor to the neutral point of the three-phase motor. Compared to a three-phase or a standalone two-phase inverter, it eliminates one phase leg and shares the control electronics between the two drives, thus significantly reducing the component count of the compressor drive. To demonstrate that the speed and torque of the two PM motors can be controlled independently, a control strategy was implemented in a digital signal processor, which includes a rotor flux field orientation based control (RFOC) for the three-phase motor, a similar RFOC and a position sensorless control in the brushless dc (BLDC) mode for the two-phase motor. Control implementation issues unique to a two-phase PM motor are also discussed. Test results with the three-phase motor running in the ac synchronous (ACS) mode while the two-phase motor either in the ACS or the BLDC mode are included to verify the independent speed and torque control capability of the integrated drive.

  20. Periodic permanent magnet development for linear collider X-band klystrons

    SciTech Connect (OSTI)

    Sprehn, D.; Caryotakis, G.; Jongewaard, E.; Phillips, R. [Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States)

    1999-05-07

    The Stanford Linear Accelerator Center (SLAC) klystron group is currently designing, fabricating and testing 11.424 GHz klystrons with peak output powers from 50 to 75 MW at 1 to 2 {mu}s rf pulsewidths as part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). In order to eliminate the projected operational-year energy bill for klystron solenoids, Periodic Permanent Magnet (PPM) focusing has been employed on our latest X-band klystron designs. A PPM beam tester has operated at the same repetition rate, voltage and average beam power required for a 75-MW NLC klystron. Prototype 50 and 75-MW PPM klystrons were built and tested during 1996 and 1997 which operate from 50 to 70 MW at efficiencies greater than 55%. Construction and testing of 75-MW research klystrons will continue while the design and reliability is perfected. This paper will discuss the design of these PPM klystrons and the results of testing to date along with future plans for the development of a low-cost Design for Manufacture (DFM) 75-MW klystron and invitation for industry participation.

  1. Periodic permanent magnet development for linear collider X-band klystrons

    SciTech Connect (OSTI)

    Sprehn, D.; Caryotakis, G.; Jongewaard, E.; Phillips, R. [Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States)

    1999-05-01

    The Stanford Linear Accelerator Center (SLAC) klystron group is currently designing, fabricating and testing 11.424 GHz klystrons with peak output powers from 50 to 75 MW at 1 to 2 {mu}s rf pulsewidths as part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). In order to eliminate the projected operational-year energy bill for klystron solenoids, Periodic Permanent Magnet (PPM) focusing has been employed on our latest X-band klystron designs. A PPM beam tester has operated at the same repetition rate, voltage and average beam power required for a 75-MW NLC klystron. Prototype 50 and 75-MW PPM klystrons were built and tested during 1996 and 1997 which operate from 50 to 70 MW at efficiencies greater than 55{percent}. Construction and testing of 75-MW research klystrons will continue while the design and reliability is perfected. This paper will discuss the design of these PPM klystrons and the results of testing to date along with future plans for the development of a low-cost Design for Manufacture (DFM) 75-MW klystron and invitation for industry participation. {copyright} {ital 1999 American Institute of Physics.}

  2. Improvement of microwave feeding on a large bore ECRIS with permanent magnets by using coaxial semi-dipole antenna

    SciTech Connect (OSTI)

    Kurisu, Yosuke; Sakamoto, Naoki; Kiriyama, Ryutaro; Takenaka, Tomoya; Nozaki, Dai; Yano, Keisuke; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki

    2012-11-06

    We are constructing a tandem type electron cyclotron resonance (ECR) ion source (ECRIS). The first stage of this ECRIS has a large-bore with cylindrically comb-shaped permanent magnets. 2.45GHz and 11-13GHz microwaves can be supplied individually and simultaneously to the plasma chamber. For 2.45GHz, a coaxial semi-dipole antenna is used to feed the microwaves. In previous experiments, there were two problems encountered when running the 2.45GHz microwaves. High incident power was necessary to keep ECR discharge at low operating pressure because of high reflected microwave power. The surface of a support insulator between the inner and the outer electrodes of coaxial semi-dipole antenna was easily metalized by sputtering of the metal wall inside the chamber. The purpose of this study was to solve these problems. Performing several simulation experiments supports the hypothesis that the position of the support insulator is significant for microwave power efficiency. The end result was the ability to sustain ECR discharges at extremely low incident microwave power, several tens of watts, by optimized matching of the position and shape of the insulator.

  3. Radial-Gap Permanent Magnet Motor and Drive Research FY 2004

    SciTech Connect (OSTI)

    McKeever, J.W.

    2005-02-11

    The objective of this task was to study permanent magnet (PM) radial-gap traction drive systems that could meet the U.S. Department of Energy FreedomCAR Program's 2010 goals to expose weaknesses or identify strengths. Initially, the approach was to compare attributes such as physical deformations during operation, performance (torque, power, efficiency versus speed), material requirements (strength), material costs, manufacturability, weight, power density, specific power, reliability, and drivability for specific motors. Three motors selected were the commercially available 60-kW radial-gap surface-mounted PM motor manufactured by UQM Technologies, Inc.; a hypothetical PM motor with rotor-supported magnets similar to the Honda MCF-21; and Delphi's automotive electric machine drive motor, whose rotor is a ferromagnetic cylinder, held at one end by a shaft that supports the magnets on its inner surface. Potential problems have appeared related to PM motors, such as (1) high no-load spin losses and high operational power losses, probably from eddy current losses in the rotor; (2) the undemonstrated dual mode inverter control (DMIC) for driving a brushless dc motor (BDCM) (UQM and Delphi motors); (3) uncertainty about the potential for reducing current with DMIC; and (4) uncertainty about the relation between material requirements and maximum rotor speed. Therefore, the approach was changed to study in detail three of the comparison attributes: drivability, performance, and material requirements. Drivability and related problems were examined by demonstrating that DMIC may be used to drive an 18-pole 30-kW PM motor to 6000 rpm, where the maximum electrical frequency is 900 Hz. An available axial-gap test motor with 18 poles was used because its control is identical to that of a radial gap PM motor. Performance was analytically examined, which led to a derivation showing that DMIC controls a PM motor so that the motor uses minimum current to produce any power

  4. Low-field permanent magnet quadrupoles in a new relativistic-klystron two-beam accelerator design

    SciTech Connect (OSTI)

    Yu, S.; Sessler, A.

    1995-02-01

    Permanent magnets play a central role in the new relativistic klystron two-beam-accelerator design. The two key goals of this new design, low cost and the suppression of beam break-up instability are both intimately tied to the permanent magnet quadrupole focusing system. A recently completed systems study by a joint LBL-LLNL team concludes that a power source for a 1 TeV center-of-mass Next Linear Collider based on the new TBA design can be as low as $1 billion, and the efficiency (wall plug to rf) is estimated to be 36%. End-to-end simulations of longitudinal and transverse beam dynamics show that the drive beam is stable over the entire TBA unit.

  5. Intense beams from gases generated by a permanent magnet ECR ion source at PKU

    SciTech Connect (OSTI)

    Ren, H. T.; Chen, J. E.; Peng, S. X.; Lu, P. N.; Yan, S.; Zhou, Q. F.; Zhao, J.; Yuan, Z. X.; Guo, Z. Y.

    2012-02-15

    An electron cyclotron resonance (ECR) ion source is designed for the production of high-current ion beams of various gaseous elements. At the Peking University (PKU), the primary study is focused on developing suitable permanent magnet ECR ion sources (PMECRs) for separated function radio frequency quadrupole (SFRFQ) accelerator and for Peking University Neutron Imaging Facility. Recently, other kinds of high-intensity ion beams are required for new acceleration structure demonstration, simulation of fusion reactor material irradiation, aviation bearing modification, and other applications. So we expanded the ion beam category from O{sup +}, H{sup +}, and D{sup +} to N{sup +}, Ar{sup +}, and He{sup +}. Up to now, about 120 mA of H{sup +}, 83 mA of D{sup +}, 50 mA of O{sup +}, 63 mA of N{sup +}, 70 mA of Ar{sup +}, and 65 mA of He{sup +} extracted at 50 kV through a {phi} 6 mm aperture were produced by the PMECRs at PKU. Their rms emittances are less than 0.2 {pi} mm mrad. Tungsten samples were irradiated by H{sup +} or He{sup +} beam extracted from this ion source and H/He holes and bubbles have been observed on the samples. A method to produce a high intensity H/He mixed beam to study synergistic effect is developed for nuclear material irradiation. To design a He{sup +} beam injector for coupled radio frequency quadruple and SFRFQ cavity, He{sup +} beam transmission experiments were carried out on PKU low energy beam transport test bench and the transmission was less than 50%. It indicated that some electrode modifications must be done to decrease the divergence of He{sup +} beam.

  6. Control of Surface Mounted Permanent Magnet Motors with Special Application to Fractional-Slot Concentrated Windings

    SciTech Connect (OSTI)

    Lawler, J.S.

    2005-12-21

    It is well known that the ability of the permanent magnet synchronous machine (PMSM) to operate over a wide constant power speed range (CPSR) is dependent upon the machine inductance [1,2,3,4,5]. Early approaches for extending CPSR operation included adding supplementary inductance in series with the motor [1] and the use of anti-parallel thyristor pairs in series with the motor-phase windings [5]. The increased inductance method is compatible with a voltage-source inverter (VSI) controlled by pulse-width modulation (PWM) which is called the conventional phase advance (CPA) method. The thyristor method has been called the dual mode inverter control (DMIC). Neither of these techniques has met with wide acceptance since they both add cost to the drive system and have not been shown to have an attractive cost/benefit ratio. Recently a method has been developed to use fractional-slot concentrated windings to significantly increase the machine inductance [6]. This latest approach has the potential to make the PMSM compatible with CPA without supplemental external inductance. If the performance of such drive is acceptable, then the method may make the PMSM an attractive option for traction applications requiring a wide CPSR. A 30 pole, 6 kW, 6000 maximum revolutions per minute (rpm) prototype of the fractional-slot PMSM design has been developed [7]. This machine has significantly more inductance than is typical of regular PMSMs. The prototype is to be delivered in late 2005 to the Oak Ridge National Laboratory (ORNL) for testing and development of a suitable controller. In advance of the test/control development effort, ORNL has used the PMSM models developed over a number of previous studies to study the steady-state performance of high-inductance PMSM machines with a view towards control issues. The detailed steady-state model developed includes all motor and inverter-loss mechanisms and will be useful in assessing the performance of the dynamic controller to be

  7. Indirect sensing for rotor flux position of permanent magnet AC motors operating over a wide speed range

    SciTech Connect (OSTI)

    Moreira, J.C.

    1996-11-01

    This paper describes an indirect sensing, or sensorless, method for rotor flux position for brushless permanent magnet (BPM) motors operating over a wide speed range, while keeping maximum torque per ampere and/or maximum efficiency capabilities. The method described is particularly applicable to trapezoidal back emf type of BPM motors. The typical trapezoidal waveform of the motor internal voltages (or back emf) contains a fundamental and higher order frequency harmonics. In particular, the third harmonic component is extracted from the stator phase voltages while the fundamental and other polyphase components are eliminated via a simple summation of the three phase voltages. The resulting third harmonic signal keeps a constant phase relationship with the rotor flux for any motor speed and load condition, and is practically free of noise that can be introduced by the inverter switching, making this a robust sensing method. In contrast with indirect sensing methods based on detection of the back-emf signal that require heavy filtering, the third harmonic signal needs only a small amount of filtering to eliminate the switching frequency and its side bands. As a result, the method described here is not sensitive to filtering delays, allowing the motor to achieve a good performance over a wide speed range. Motor starting is also superior with this method since the third harmonic signal can be detected and processed at lower speeds than for the conventional method of back-emf sensing. Moreover, an alternative way to acquire the third harmonic signal without the need to access the stator neutral terminal is discussed. This is particularly interesting with the motor neutral connection is not available or expensive to have access. The third harmonic indirect sensing scheme is implemented in the laboratory and compared to a conventional back-emf sensing method.

  8. Dynamic high pressure process for fabricating superconducting and permanent magnetic materials

    DOE Patents [OSTI]

    Nellis, William J.; Maple, M. Brian; Geballe, Theodore H.

    1988-01-01

    Shock wave formation of superconductive ceramic oxide electric and magnetic circuit elements with improved microstructures and mechanical properties.

  9. Dynamic high pressure process for fabricating superconducting and permanent magnetic materials

    DOE Patents [OSTI]

    Nellis, W.J.; Maple, M.B.; Geballe, T.H.

    1987-10-23

    Shock wave formation of superconductive ceramic oxide electric and magnetic circuit elements with improved microstructures and mechanical properties. 10 figs.

  10. Study of the Advantages of Internal Permanent Magnet Drive Motor with Selectable Windings for Hybrid-Electric Vehicles

    SciTech Connect (OSTI)

    Otaduy, P.J.; Hsu, J.S.; Adams, D.J.

    2007-11-30

    This report describes research performed on the viability of changing the effectively active number of turns in the stator windings of an internal permanent magnet (IPM) electric motor to strengthen or weaken the magnetic fields in order to optimize the motor's performance at specific operating speeds and loads. Analytical and simulation studies have been complemented with research on switching mechanisms to accomplish the task. The simulation studies conducted examine the power and energy demands on a vehicle following a series of standard driving cycles and the impact on the efficiency and battery size of an electrically propelled vehicle when it uses an IPM motor with turn-switching capabilities. Both full driving cycle electric propulsion and propulsion limited starting from zero to a set speed have been investigated.

  11. Ultra-high speed permanent magnet axial gap alternator with multiple stators

    DOE Patents [OSTI]

    Hawsey, Robert A.; Bailey, J. Milton

    1991-01-01

    An ultra-high speed, axial gap alternator that can provide an output to a plurality of loads, the alternator providing magnetic isolation such that operating conditions in one load will not affect operating conditions of another load. This improved alternator uses a rotor member disposed between a pair of stator members, with magnets disposed in each of the rotor member surfaces facing the stator members. The magnets in one surface of the rotor member, which alternate in polarity, are isolated from the magnets in the other surface of the rotor member by a disk of magnetic material disposed between the two sets of magents. In the preferred embodiment, this disk of magnetic material is laminated between two layers of non-magnetic material that support the magnets, and the magnetic material has a peripheral rim that extends to both surfaces of the rotor member to enhance the structural integrity. The stator members are substantially conventional in construction in that equally-spaced and radially-oriented slots are provided, and winding members are laid in these slots. A unit with multiple rotor members and stator members is also described.

  12. Carbon-Based Magnets: Discovery & Design of Novel Permanent Magnets using Non-strategic Elements having Secure Supply Chains

    SciTech Connect (OSTI)

    2012-01-01

    REACT Project: VCU is developing a new magnet for use in renewable power generators and EV motors that requires no rare earth minerals. Rare earths are difficult and expensive to process, but they make electric motors and generators smaller, lighter, and more efficient. VCU would replace the rare earth minerals in EV motor magnets with a low-cost and abundant carbon-based compound that resembles a fine black powder. This new magnet could demonstrate the same level of performance as the best commercial magnets available today at a significantly lower cost. The ultimate goal of this project is to demonstrate this new magnet in a prototype electric motor.

  13. An all permanent magnet electron cyclotron resonance ion source for heavy ion therapy

    SciTech Connect (OSTI)

    Cao, Yun Li, Jia Qing; Sun, Liang Ting; Zhang, Xue Zhen; Feng, Yu Cheng; Wang, Hui; Ma, Bao Hua; Li, Xi Xia

    2014-02-15

    A high charge state all permanent Electron Cyclotron Resonance ion source, Lanzhou All Permanent ECR ion source no. 3-LAPECR3, has been successfully built at IMP in 2012, which will serve as the ion injector of the Heavy Ion Medical Machine (HIMM) project. As a commercial device, LAPECR3 features a compact structure, small size, and low cost. According to HIMM scenario more than 100 e?A of C{sup 5+} ion beam should be extracted from the ion source, and the beam emittance better than 75 ?*mm*mrad. In recent commissioning, about 120 e?A of C{sup 5+} ion beam was got when work gas was CH{sub 4} while about 262 e?A of C{sup 5+} ion beam was obtained when work gas was C{sub 2}H{sub 2} gas. The design and construction of the ion source and its low-energy transportation beam line, and the preliminary commissioning results will be presented in detail in this paper.

  14. Electroplated L1{sub 0} CoPt thick-film permanent magnets

    SciTech Connect (OSTI)

    Oniku, Ololade D. Qi, Bin; Arnold, David P.

    2014-05-07

    The fabrication and magnetic characterization of 15-?m-thick electroplated L1{sub 0} CoPt hard magnets with good magnetic properties is reported in this paper. Experimental study of the dependence of the magnets' properties on annealing temperature reveals that an intrinsic coercivity H{sub ci}?=??800?kA/m (10 kOe), squareness >0.8, and energy product of >150?kJ/m{sup 3} are obtained for photolithographically patterned structures (250??m??2?mm stripes; 15??m thickness) electroplated on silicon substrates and annealed in hydrogen forming gas at 700?C. Scanning electron microscopy is used to inspect the morphology of both the as-deposited and annealed magnetic layers, and X-ray Diffractometer analysis on the magnets annealed at 700?C confirm a phase transformation to an ordered L1{sub 0} CoPt structure, with a minor phase of hcp Co. These thick films are intended for microsystems/MEMS applications.

  15. Manganese-Based Magnets: Manganese-Based Permanent Magnet with 40 MGOe at 200°C

    SciTech Connect (OSTI)

    2012-01-01

    REACT Project: PNNL is working to reduce the cost of wind turbines and EVs by developing a manganese-based nano-composite magnet that could serve as an inexpensive alternative to rare-earth-based magnets. The manganese composite, made from low-cost and abundant materials, could exceed the performance of today’s most powerful commercial magnets at temperature higher than 200°C. Members of PNNL’s research team will leverage comprehensive computer high-performance supercomputer modeling and materials testing to meet this objective. Manganese-based magnets could withstand higher temperatures than their rare earth predecessors and potentially reduce the need for any expensive, bulky engine cooling systems for the motor and generator. This would further contribute to cost savings for both EVs and wind turbines.

  16. Robust ferromagnetism in the compressed permanent magnet Sm2Co17...

    Office of Scientific and Technical Information (OSTI)

    Resource Type: Journal Article Resource Relation: Journal Name: Physical Review B, vol. 104408, no. 10, September 8, 2014, pp. 104408 Research Org: Lawrence Livermore...

  17. Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction

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

    Kim, Daejin; Powell, Lawrence E.; Delmau, Lætitia H.; Peterson, Eric S.; Herchenroeder, Jim; Bhave, Ramesh R.

    2015-06-24

    In this paper, the rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets and industrial scrap magnets via membrane assisted solvent extraction (MSX). A hollow fiber membrane system was evaluated to extract REEs in a single step with the feed and strip solutions circulating continuously through the MSX system. The effects of several experimental variables on REE extraction such as flow rate, concentration of REEs in the feed solution, membrane configuration, and composition of acids were investigated with the MSX system. A multimembrane module configuration with REEs dissolved in aqueous nitric acidmore » solutions showed high selectivity for REE extraction with no coextraction of non-REEs, whereas the use of aqueous hydrochloric acid solution resulted in coextraction of non-REEs due to the formation of chloroanions of non-REEs. The REE oxides were recovered from the strip solution through precipitation, drying, and annealing steps. Finally, the resulting REE oxides were characterized with XRD, SEM-EDX, and ICP-OES, demonstrating that the membrane assisted solvent extraction is capable of selectively recovering pure REEs from the industrial scrap magnets.« less

  18. Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction

    SciTech Connect (OSTI)

    Kim, Daejin; Powell, Lawrence E.; Delmau, Lætitia H.; Peterson, Eric S.; Herchenroeder, Jim; Bhave, Ramesh R.

    2015-06-24

    In this paper, the rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets and industrial scrap magnets via membrane assisted solvent extraction (MSX). A hollow fiber membrane system was evaluated to extract REEs in a single step with the feed and strip solutions circulating continuously through the MSX system. The effects of several experimental variables on REE extraction such as flow rate, concentration of REEs in the feed solution, membrane configuration, and composition of acids were investigated with the MSX system. A multimembrane module configuration with REEs dissolved in aqueous nitric acid solutions showed high selectivity for REE extraction with no coextraction of non-REEs, whereas the use of aqueous hydrochloric acid solution resulted in coextraction of non-REEs due to the formation of chloroanions of non-REEs. The REE oxides were recovered from the strip solution through precipitation, drying, and annealing steps. Finally, the resulting REE oxides were characterized with XRD, SEM-EDX, and ICP-OES, demonstrating that the membrane assisted solvent extraction is capable of selectively recovering pure REEs from the industrial scrap magnets.

  19. High performance Nd-Fe-B permanent magnets without critical elements

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

    Pathak, Arjun K.; Gschneidner, Jr., K. A.; Khan, M.; McCallum, R. W.; Pecharsky, V. K.

    2016-01-28

    Scanning electron microscopy, and magnetization measurements reveal that as cast (Nd1–xCex)2Fe14B alloys contain significant amounts of α-Fe that can be dramatically reduced by annealing the alloys at 1000 °C for 3 days. The room temperature intrinsic coercivity, Hci, of (Nd0.8Ce0.2)2.2Fe14B melt spun ribbons was found to be 11 kOe, which is ~32 to ~10% higher in comparison to that of Nd2Fe14B (Hci = 8.3 kOe), and (Nd0.8Ce0.2)2.0Fe14B (Hci = 10 kOe), respectively. The substitution of Co for Fe in (Nd0.8Ce0.2)2Fe14–zCozB significantly increases both TC and the maximum energy product, (BH)max. Our study shows that both Co-containing and Co-free Ce-substituted Nd2Fe14Bmore » alloys have excellent magnetic properties at room temperature and above. As a result, the experimental results also demonstrate the potential of Nd-Ce-Fe-TM-B based alloys as alternative to expensive Dy-containing high performance rare earth magnets.« less

  20. A microcomputer-based control and simulation of an advanced IPM (interior permanent magnet) synchronous machine drive system for electric vehicle propulsion

    SciTech Connect (OSTI)

    Bose, B.K.; Szczesny, P.M.

    1987-01-01

    Advanced digital control and computer-aided control system design techniques are playing key roles in the complex drive system design and control implementation. The paper describes a high performance microcomputer-based control and digital simulation of an inverter-fed interior permanent magnet (IPM) synchronous machine which uses Neodymium-Iron-Boron magnet. The fully operational four-quadrant drive system includes constant-torque region with zero speed operation and high speed field-weakening constant-power region. The control uses vector or field-oriented technique in constant-torque region with the direct axis aligned to the stator flux, whereas the constant-power region control is based on torque angle orientation of the impressed square-wave voltage. All the key feedback signals for the control are estimated with precision. The drive system is basically designed with an outer torque control loop for electric vehicle appliation, but speed and position control loops can be added for other industrial applications. The distributed microcomputer-based control system is based on Intel-8096 microcontroller and Texas Instruments TMS32010 type digital signal processor. The complete drive system has been simulated using the VAX-based simulation language SIMMON to verify the feasibility of the control laws and to study the performances of the drive system. The simulation results are found to have excellent correlation with the laboratory breadboard tests. 19 refs., 14 figs., 5 tabs.

  1. Contol of Surface Mounted Permanent Magnet Motors with Special Application to Motors with Fractional-Slot Concentrated Windings

    SciTech Connect (OSTI)

    Patil, N.; Lawler, J.S.; McKeever, J.

    2007-07-31

    A 30-pole, 6-kW prototype of a fractional-slot permanent magnet synchronous motor (PMSM) design has been developed to operate at a maximum speed of 6000 rpm [1,2]. This machine has significantly more inductance than regular PMSMs with distributed windings. The prototype was delivered in April 2006 to the Oak Ridge National Laboratory (ORNL) for testing and development of a suitable controller. To prepare for this test/control development effort, ORNL used PMSM models developed over a number of previous studies to preview the control issues that arise when a dynamic controller drives a high inductance PMSM machine during steady state performance evaluations. The detailed steady state model developed includes all motor and inverter loss mechanisms and was useful for assessing the performance of the dynamic controller before it was put into operation. This report documents the results of tests demonstrating the effectiveness of ORNL's simple low-cost control scheme during characterization of the fractional-slot concentrated windings (FSCW) PMSM motor. The control scheme is simple because only the supply voltage magnitude and the phase angle between the back-electromotive force (emf) and the supply voltage is controlled. It is low-cost because it requires no current or phase voltage sensors.

  2. Final Technical Report for the project titled "Manganese Based Permanent Magnet with 40 MGOe at 200°C"

    SciTech Connect (OSTI)

    Cui, Jun

    2015-12-31

    The objective of project was to develop MnBi based permanent magnet for high temperature application (~150°C). This objective is derived based on MnBi’s unique positive temperature dependence of coercivity, which is doubled from ~1 T at RT to ~2.5 T at 200°C. Because of its limited magnetization (<0.9 T at RT), the MnBi magnet is best suited to fill in the gap between rare earth based NdFeB-Dy or SmCo magnet (20 MGOe) and the AlNiCo magnet (10 MGOe) at 150°C. It is expected that if successfully developed, MnBi will effectively mitigate the world’s demand on Dy. Before this project, the highest LTP content in MnBi powder is about 90% if the quantity of the powder is less than 5 gram (using melt-spin method); or 80% if the quantity is greater than 100 gram (using conventional powder metallurgical method such as arc melting and annealing). After this project, large quantities (5kg/batch) with high LPT phase content (>92 wt%) can be routinely synthesized. This achievement is made possible by the newly developed synthesis method based on conventional metallurgical processing technique involving arc melting, two-stage ingot annealing, grinding, sieving, and vacuum annealing. Before this project, the finest powder particle size is about 35 μm with overall powder composition maintaining at about 85% LTP phase. The reason why LTP phase content is listed along with particle size is because LTP MnBi is easy to decompose when exposed to temperature higher than 350 °C. As result, only low energy ball milling can be used to refine the particle size; moreover, the ball milling time cannot exceed 4 hrs, or else the decomposed LTP MnBi phase will exceed 10%. After this project, the finest powder size is reduced to 1~5 μm while maintain the 90% LTP MnBi phase content. This achievement is made possible by a newly developed cryogenic ball milling system, which provides -70 °C ambient for the rolling container. Before this project, it is not clear if MnBi will

  3. Optimization of L1{sub 0} FePt/Fe{sub 45}Co{sub 55} thin films for rare earth free permanent magnet applications

    SciTech Connect (OSTI)

    Giannopoulos, G. Psycharis, V.; Niarchos, D.; Reichel, L.; Markou, A.; Panagiotopoulos, I.; Damm, C.; Fähler, S.; Khan, Imran; Hong, Jisang

    2015-06-14

    The magnetic properties of magnetron sputtered bilayers consisting of Fe{sub 45}Co{sub 55} ultrathin layers on top of L1{sub 0} FePt films epitaxially grown on MgO substrates are studied in view of their possible application as rare earth free permanent magnets. It is found that FePt layers induce a tetragonal distortion to the Fe-Co layers which leads to increased anisotropy. This allows to take advantage of the Fe-Co high magnetic moment with less significant loss of the coercivity compared to a typical hard/soft exchange spring system. A maximum energy product approaching 50 MGOe is obtained for a FePt(7 ML)/FeCo/(5 ML) sample. The results are in accordance with first-principles computational methods, which predict that even higher energy products are possible for micromagnetically optimized microstructures.

  4. Memorandum, Approval of a Permanent Variance Regarding Static Magnetic Fields at Brookhaven National Laboratory (Variance 102 1)

    Broader source: Energy.gov [DOE]

    Approval of a Permanenet Variance Regarding Static Magnetic Fields at Brookhaven National Laboratory (Variance 1021)

  5. SCALING LAW OF RELATIVISTIC SWEET-PARKER-TYPE MAGNETIC RECONNECTION

    SciTech Connect (OSTI)

    Takahashi, Hiroyuki R.; Kudoh, Takahiro; Masada, Youhei; Matsumoto, Jin

    2011-10-01

    Relativistic Sweet-Parker-type magnetic reconnection is investigated by relativistic resistive magnetohydrodynamic (RRMHD) simulations. As an initial setting, we assume anti-parallel magnetic fields and a spatially uniform resistivity. A perturbation imposed on the magnetic fields triggers magnetic reconnection around a current sheet, and the plasma inflows into the reconnection region. The inflows are then heated due to ohmic dissipation in the diffusion region and finally become relativistically hot outflows. The outflows are not accelerated to ultrarelativistic speeds (i.e., Lorentz factor {approx_equal} 1), even when the magnetic energy dominates the thermal and rest mass energies in the inflow region. Most of the magnetic energy in the inflow region is converted into the thermal energy of the outflow during the reconnection process. The energy conversion from magnetic to thermal energy in the diffusion region results in an increase in the plasma inertia. This prevents the outflows from being accelerated to ultrarelativistic speeds. We find that the reconnection rate R obeys the scaling relation R{approx_equal}S{sup -0.5}, where S is the Lundquist number. This feature is the same as that of non-relativistic reconnection. Our results are consistent with the theoretical predictions of Lyubarsky for Sweet-Parker-type magnetic reconnection.

  6. Experimental Approach of a High Performance Control of Two PermanentMagnet Synchronous Machines in an Integrated Drive for Automotive Applications

    SciTech Connect (OSTI)

    Tang, Lixin; Su, Gui-Jia

    2006-01-01

    The close-loop digital signal processor (DSP) control of an integrated-dual inverter, which is able to drive two permanent magnet (PM) motors independently, is presented and evaluated experimentally. By utilizing the neutral point of the main traction motor, only two inverter poles are needed for the two-phase auxiliary motor. The modified field-oriented control scheme for this integrated inverter was introduced and employed in real-time control. The experimental results show the inverter is able to control two drives independently. An integrated, component count reduced drive is achieved.

  7. Design Features of a Planar Hybrid/Permanent Magnet Strong Focusing Undulator for Free Electron Laser (FEL) And Synchrotron Radiation (SR) Applications

    SciTech Connect (OSTI)

    Tatchyn, Roman; /SLAC

    2011-09-09

    Insertion devices for Angstrom-wavelength Free Electron Laser (FEL) amplifiers driven by multi-GeV electron beams generally require distributed focusing substantially stronger than their own natural focusing fields. Over the last several years a wide variety of focusing schemes and configurations have been proposed for undulators of this class, ranging from conventional current-driven quadrupoles external to the undulator magnets to permanent magnet (PM) lattices inserted into the insertion device gap. In this paper we present design studies of a flexible high-field hybrid/PM undulator with strong superimposed planar PM focusing proposed for a 1.5 Angstrom Linac Coherent Light Source (LCLS) driven by an electron beam with a 1 mm-mr normalized emittance. Attainable field parameters, tuning modes, and potential applications of the proposed structure are discussed.

  8. Control of Surface Mounted Permanent Magnet Motors with Special Application to Fractional-Slot Motors with Concentrated Windings

    SciTech Connect (OSTI)

    McKeever, John W; Patil, Niranjan; Lawler, Jack

    2007-07-01

    A 30 pole, 6 kW, and 6000 maximum revolutions per minute (rpm) prototype of the permanent magnet synchronous motor (PMSM) with fractional-slot concentrated windings (FSCW) has been designed, built, and tested at the University of Wisconsin at Madison (UWM). This machine has significantly more inductance than that of regular PMSMs. The prototype was delivered in April 2006 to the Oak Ridge National Laboratory (ORNL) for testing and development of a controller that will achieve maximum efficiency. In advance of the test/control development effort, ORNL has used the PMSM models developed over a number of previous studies to study how steady state performance of high inductance PMSM machines relates to control issues. This report documents the results of this research. The amount of inductance that enables the motor to achieve infinite constant power speed ratio (CPSR) is given by L{sub {infinity}} = E{sub b}/{Omega}{sub b}I{sub R}, where E{sub b} is the root-mean square (rms) magnitude of the line-to-neutral back-electromotive force (emf) at base speed, {Omega}{sub b} is the base speed in electrical radians per second, and I{sub R} is the rms current rating of the motor windings. The prototype machine that was delivered to ORNL has about 1.5 times as much inductance as a typical PMSM with distributed integral slot windings. The inventors of the FSCW method, who designed the prototype machine, remarked that they were 'too successful' in incorporating inductance into their machine and that steps would be taken to modify the design methodology to reduce the inductance to the optimum value. This study shows a significant advantage of having the higher inductance rather than the optimal value because it enables the motor to develop the required power at lower current thereby reducing motor and inverter losses and improving efficiency. The main problem found with high inductance machines driven by a conventional phase advance (CPA) method is that the motor current at high

  9. DYNAMO ACTION AND MAGNETIC CYCLES IN F-TYPE STARS

    SciTech Connect (OSTI)

    Augustson, Kyle C.; Toomre, Juri; Brun, Allan Sacha

    2013-11-10

    Magnetic activity and differential rotation are commonly observed features on main-sequence F-type stars. We seek to make contact with such observations and to provide a self-consistent picture of how differential rotation and magnetic fields arise in the interiors of these stars. The three-dimensional magnetohydrodynamic anelastic spherical harmonic code is employed to simulate global-scale convection and dynamo processes in a 1.2 M{sub ☉} F-type star at two rotation rates. The simulations are carried out in spherical shells that encompass most of the convection zone and a portion of the stably stratified radiative zone below it, allowing us to explore the effects a stable zone has upon the morphology of the global-scale magnetic fields. We find that dynamo action with a high degree of time variation occurs in the star rotating more rapidly at 20 Ω{sub ☉}, with the polarity of the mean field reversing on a timescale of about 1600 days. Between reversals, the magnetic energy rises and falls with a fairly regular period, with three magnetic energy cycles required to complete a reversal. The magnetic energy cycles and polarity reversals arise due to a linking of the polar-slip instability in the stable region and dynamo action present in the convection zone. For the more slowly rotating case (10 Ω{sub ☉}), persistent wreaths of magnetism are established and maintained by dynamo action. Compared to their hydrodynamic progenitors, the dynamo states here involve a marked reduction in the exhibited latitudinal differential rotation, which also vary during the course of a cycle.

  10. Development of Radically Enhanced alnico Magnets (DREAM) for...

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

    energy product permanent magnet of the alnico type in bulk final shapes without rare earth elements that will be competitive with existing commercial RE-based magnets on a cost ...

  11. Spin-down dynamics of magnetized solar-type stars

    SciTech Connect (OSTI)

    Oglethorpe, R. L. F.; Garaud, P.

    2013-12-01

    It has long been known that solar-type stars undergo significant spin-down, via magnetic braking, during their main-sequence lifetimes. However, magnetic braking only operates on the surface layers; it is not yet completely understood how angular momentum is transported within the star and how rapidly the spin-down information is communicated to the deep interior. In this work, we use insight from recent progress in understanding internal solar dynamics to model the interior of other solar-type stars. We assume, following Gough and McIntyre, that the bulk of the radiation zone of these stars is held in uniform rotation by the presence of an embedded large-scale primordial field, confined below a stably stratified, magnetic-free tachocline by large-scale meridional flows downwelling from the convection zone. We derive simple equations to describe the response of this model interior to spin-down of the surface layers, which are identical to the two-zone model of MacGregor and Brenner, with a coupling timescale proportional to the local Eddington-Sweet timescale across the tachocline. This timescale depends both on the rotation rate of the star and on the thickness of the tachocline, and it can vary from a few hundred thousand years to a few Gyr, depending on stellar properties. Qualitative predictions of the model appear to be consistent with observations, although they depend sensitively on the assumed functional dependence of the tachocline thickness on the stellar rotation rate.

  12. Magnetic properties of Ni substituted Y-type barium ferrite

    SciTech Connect (OSTI)

    Won, Mi Hee; Kim, Chul Sung

    2014-05-07

    Y-type barium hexaferrite is attractive material for various applications, such as high frequency antennas and RF devices, because of its interesting magnetic properties. Especially, Ni substituted Y- type hexaferrites have higher magnetic ordering temperature than other Y-type. We have investigated macroscopic and microscopic properties of Y-type barium hexaferrite. Ba{sub 2}Co{sub 2−x}Ni{sub x}Fe{sub 12}O{sub 22} (x = 0, 0.5, 1.0, 1.5, and 2.0) samples are prepared by solid-state reaction method and studied by X-ray diffraction (XRD), vibrating sample magnetometer, and Mössbauer spectroscopy, as well as a network analyzer for high frequency characteristics. The XRD pattern is analyzed by Rietveld refinement method and confirms the hexagonal structure with R-3m. The hysteresis curve shows ferrimagnetic behavior. Saturation magnetization (M{sub s}) decreases with Ni contents. Ni{sup 2+}, which preferentially occupies the octahedral site with up-spin sub-lattice, has smaller spin value S of 1 than Co{sup 2+} having S = 3/2. The zero-field-cooled (ZFC) measurement of Ba{sub 2}Co{sub 1.5}Ni{sub 0.5}Fe{sub 12}O{sub 22} shows that Curie and spin transition temperatures are found to be 718 K and 209 K, respectively. The Curie temperature T{sub C} is increased with Ni contents, while T{sub S} is decreased with Ni. The Mössbauer spectra were measured at various temperatures and fitted by using a least-squares method with six sextet of six Lorentzian lines for Fe sites, corresponding to the 3b{sub VI}, 6c{sub IV}*, 6c{sub VI}, 18h{sub VI}, 6c{sub IV}, and 3a{sub IV} sites at below T{sub C}. From Mössbauer measurements, we confirmed the spin state of Fe ion to be Fe{sup 3+} and obtained the isomer shift (δ), magnetic hyperfine field (H{sub hf}), and the occupancy ratio of Fe ions at six sub-lattices. The complex permeability and permittivity are measured between 100 MHz and 4 GHz, suggesting that Y-type barium hexaferrite is promising for antenna

  13. 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.

  14. Magnetic order and crystal structure study of YNi{sub 4}Si-type NdNi{sub 4}Si

    SciTech Connect (OSTI)

    Yao, Jinlei; Isnard, O.; Morozkin, A.V.; Ivanova, T.I.; Koshkid'ko, Yu.S.; Bogdanov, A.E.; Nikitin, S.A.; Suski, W.

    2015-02-15

    Magnetic measurements and neutron powder diffraction investigation of the magnetic structure of the orthorhombic YNi{sub 4}Si-type (space group Cmmm) NdNi{sub 4}Si compound are presented. The magnetocaloric effect of NdNi{sub 4}Si is calculated in terms of the isothermal magnetic entropy change and it reaches the maximum value of –3.3 J/kg K for a field change of 50 kOe near T{sub C}=12 K. Below ∼12 K, NdNi{sub 4}Si exhibits a commensurate b-axis collinear ferromagnetic ordering with the Cmm′m magnetic space group in a zero magnetic field. At 1.5 K, the neodymium atoms have the magnetic moment of 2.37(5) μ{sub B}. The orthorhombic crystal structure and its thermal evolution are discussed in comparison with the CaCu{sub 5}-type compound. - Graphical abstract: The NdNi{sub 4}Si supplement the series of the orthorhombic derivative of the CaCu{sub 5}-type, namely the YNi{sub 4}Si-type, RNi{sub 4}Si compounds (R=Y, La, Ce, Sm, Gd–Ho). Below ∼12 K in a zero applied magnetic field, NdNi{sub 4}Si exhibits a commensurate b-axis collinear ferromagnetic ordering with the Cmm′m magnetic space group. Compared to the CaCu{sub 5}-type NdNi{sub 4}Si compound, the YNi{sub 4}Si-type counterpart has the relatively high ferromagnetic ordering temperature (9.2 K vs. 12 K), the small magnetocaloric effect (–7.3 J/kg K vs. –3.3 J/kg K for ∆H=50 kOe), and the large magnetic anisotropy at low temperatures. In contrast with CaCu{sub 5}-type NdNi{sub 4}Si, YNi{sub 4}Si-type NdNi{sub 4}Si shows distinct hysteresis loop at 2 K.We suggest that orthorhombic distortion may be used as a prospective route for optimization of permanent magnetic properties in the family of CaCu{sub 5}-type rare earth materials. - Highlights: • Below ∼12 K the YNi{sub 4}Si-type NdNi{sub 4}Si shows a ferromagnetic ordering. • MCE of NdNi{sub 4}Si reaches value of –3.3 J/kg K in 0–50 kOe near Curie point. • NdNi{sub 4}Si exhibits b-axis ferromagnetic order with the Cmm′m magnetic space

  15. Permanent draft genome sequence of Desulfurococcus mobilis type strain DSM 2161, a thermoacidophilic sulfur-reducing crenarchaeon isolated from acidic hot springs of Hveravellir, Iceland

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

    Susanti, Dwi; Johnson, Eric F.; Lapidus, Alla; Han, James; Reddy, T. B. K.; Pilay, Manoj; Ivanova, Natalia N.; Markowitz, Victor M.; Woyke, Tanja; Kyrpides, Nikos C.; et al

    2016-01-13

    Our report presents the permanent draft genome sequence of Desulfurococcus mobilis type strain DSM 2161, an obligate anaerobic hyperthermophilic crenarchaeon that was isolated from acidic hot springs in Hveravellir, Iceland. D. mobilis utilizes peptides as carbon and energy sources and reduces elemental sulfur to H2S. A metabolic construction derived from the draft genome identified putative pathways for peptide degradation and sulfur respiration in this archaeon. Existence of several hydrogenase genes in the genome supported previous findings that H2 is produced during the growth of D. mobilis in the absence of sulfur. Interestingly, genes encoding glucose transport and utilization systems alsomore » exist in the D. mobilis genome though this archaeon does not utilize carbohydrate for growth. The draft genome of D. mobilis provides an additional mean for comparative genomic analysis of desulfurococci. In addition, our analysis on the Average Nucleotide Identity between D. mobilis and Desulfurococcus mucosus suggested that these two desulfurococci are two different strains of the same species.« less

  16. CRADA Final Report: Application of Dual-Mode Invertor Control to Commercially Available Radial-Gap Permanent Magnet Motors - Vol. 1

    SciTech Connect (OSTI)

    Lawler, J.S.; McKeever, J.W.; Downing, M.E.; Stahlhut, R.D; Bremmer, R.; Shoemaker, J.M.; Seksarian, A.K.; Poore, B.; Lutz, J.

    2006-05-01

    John Deere and Company (Deere), their partner, UQM Technologies, Inc. (UQM), and the Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center (PEEMRC) recently completed work on the cooperative research and development agreement (CRADA) Number ORNL 04-0691 outlined in this report. CRADA 04-0691 addresses two topical issues of interest to Deere: (1) Improved characterization of hydrogen storage and heat-transfer management; and (2) Potential benefits from advanced electric motor traction-drive technologies. This report presents the findings of the collaborative examination of potential operational and cost benefits from using ORNL/PEEMRC dual-mode inverter control (DMIC) to drive permanent magnet (PM) motors in applications of interest to Deere. DMIC was initially developed and patented by ORNL to enable PM motors to be driven to speeds far above base speed where the back-electromotive force (emf) equals the source voltage where it is increasingly difficult to inject current into the motor. DMIC is a modification of conventional phase advance (CPA). DMIC's dual-speed modes are below base speed, where traditional pulse-width modulation (PWM) achieves maximum torque per ampere (amp), and above base speed, where six-step operation achieves maximum power per amp. The modification that enables DMIC adds two anti-parallel thyristors in each of the three motor phases, which consequently adds the cost of six thyristors. Two features evaluated in this collaboration with potential to justify the additional thyristor cost were a possible reduction in motor cost and savings during operation because of higher efficiency, both permitted because of lower current. The collaborative analysis showed that the reduction of motor cost and base cost of the inverter was small, while the cost of adding six thyristors was greater than anticipated. Modeling the DMIC control displayed inverter efficiency gains due to reduced current, especially under

  17. Magnetic properties of Fe{sub 2}P-type R{sub 6}CoTe{sub 2} compounds...

    Office of Scientific and Technical Information (OSTI)

    Magnetic properties of Fesub 2P-type Rsub 6CoTesub 2 compounds (RGd-Er) Citation Details In-Document Search Title: Magnetic properties of Fesub 2P-type Rsub 6CoTesub 2 ...

  18. Magnetohydrodynamic study for three-dimensional instability of the Petschek type magnetic reconnection

    SciTech Connect (OSTI)

    Shimizu, T.; Kondoh, K.

    2013-12-15

    The 3D instability of the spontaneous fast magnetic reconnection process is studied with magnetohydrodynamics (MHD) simulations, where the 2D model of the spontaneous fast magnetic reconnection is destabilized in three dimension. As well known in many 2D numerical MHD studies, when a 1D current sheet is destabilized with the current-driven anomalous resistivity, the 2D Petschek type fast magnetic reconnection is established. This paper shows that the 2D Petschek type fast magnetic reconnection can be destabilized in three dimension by an initial resistive disturbance which includes a weak fluctuation in the sheet current direction, i.e., along the magnetic neutral line. The resulting 3D fast magnetic reconnection finally becomes intermittent and random through a 3D instability. In addition, it is also shown that the 3D instability is suppressed by the uniform resistivity. It suggests that the 3D instability is caused in the Petschek-type reconnection process which is characterized by a strongly localized magnetic diffusion region and the slow shock acceleration of the plasma jets and is suppressed in the Sweet-Parker type reconnection process.

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

    SciTech Connect (OSTI)

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

    2005-09-01

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

  20. 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.

  1. Light Metals Permanent Mold Casting

    SciTech Connect (OSTI)

    None

    2004-11-01

    The research will develop the gravity and/or low-pressure permanent-mold casting processes with sand or permanent-mold cores for aluminum and magnesium based alloys.

  2. Permanent magnet focused X-band photoinjector

    DOE Patents [OSTI]

    Yu, David U. L.; Rosenzweig, James

    2002-09-10

    A compact high energy photoelectron injector integrates the photocathode directly into a multicell linear accelerator with no drift space between the injection and the linac. High electron beam brightness is achieved by accelerating a tightly focused electron beam in an integrated, multi-cell, X-band rf linear accelerator (linac). The photoelectron linac employs a Plane-Wave-Transformer (PWT) design which provides strong cell-to-cell coupling, easing manufacturing tolerances and costs.

  3. High Performance Permanent Magnets for Advanced Motors

    Broader source: Energy.gov [DOE]

    2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C.

  4. Novel Flux Coupling Machine without Permanent Magnets

    Office of Energy Efficiency and Renewable Energy (EERE)

    2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C.

  5. Permanent Magnet Development for Automotive Traction Motors

    Broader source: Energy.gov [DOE]

    2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  6. Permanent isolation surface barrier development plan

    SciTech Connect (OSTI)

    Wing, N.R.

    1994-01-01

    The exhumation and treatment of wastes may not always be the preferred alternative in the remediation of a waste site. In-place disposal alternatives, under certain circumstances, may be the most desirable alternatives to use in the protection of human health and the environment. The implementation of an in-place disposal alternative will likely require some type of protective covering that will provide long-term isolation of the wastes from the accessible environment. Even if the wastes are exhumed and treated, a long-term barrier may still be needed to adequately dispose of the treated wastes or any remaining waste residuals. Currently, no {open_quotes}proven{close_quotes} long-term barrier is available. The Hanford Site Permanent Isolation Surface Barrier Development Program (BDP) was organized to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site. The permanent isolation barrier technology also could be used at other sites. Permanent isolation barriers use engineered layers of natural materials to create an integrated structure with redundant protective features. Drawings of conceptual permanent isolation surface barriers are shown. The natural construction materials (e.g., fine soil, sand, gravel, riprap, asphalt) have been selected to optimize barrier performance and longevity. The objective of current designs is to use natural materials to develop a maintenance-free permanent isolation surface barrier that isolates wastes for a minimum of 1,000 years by limiting water drainage to near-zero amounts; reducing the likelihood of plant, animal, and human intrusion; controlling the exhalation of noxious gases; and minimizing erosion-related problems.

  7. Uniaxial strain-induced magnetic order transition from E-type to A-type in orthorhombic YMnO{sub 3} from first-principles

    SciTech Connect (OSTI)

    Lin, S. X.; Fang, X. G.; Zhang, A. H.; Lu, X. B.; Gao, J. W.; Gao, X. S.; Zeng, M.; Liu, J.-M.

    2014-10-28

    The spin ordering magnetic structures of orthorhombic YMnO{sub 3} subjected to uniaxial strain have been investigated using first-principles calculations based on density functional theory. On applying compressive uniaxial strain of −0.8% along the b orientation, the spin ordering magnetic structure is predicted to change from E-type to A-type antiferromagnetic orderings. The structure analysis also reveals that the uniaxial strain has a dramatic influence on the Mn-O bond lengths and Mn-O-Mn bond angles, allowing the gradual suppression of the alternation of the long and short Mn-O-Mn bonds in the ab plane. These changes present very interesting possibilities for engineering the spin ordering along with ferroelectric property in orthorhombic YMnO{sub 3}.

  8. Development of Radically Enhanced alnico Magnets (DREAM) for Traction Drive

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

    Motors | The Ames Laboratory Development of Radically Enhanced alnico Magnets (DREAM) for Traction Drive Motors Research Personnel Publications Synthesis In order to enable domestic automobile makers to offer a broad range of vehicles with electric drive motors with either hybrid or purely electric motor drives, this project will utilize a demonstrated science-based process to design and synthesize a high energy product permanent magnet of the alnico type in bulk final shapes without rare

  9. Effects of aluminum substitution on the crystal structure and magnetic properties in Zn{sub 2}Y-type hexaferrites

    SciTech Connect (OSTI)

    Xu, Wenfei; Yang, Jing E-mail: xdtang@sist.ecnu.edu.cn; Bai, Wei; Zhang, Yuanyuan; Tang, Kai; Duan, Chun-gang; Chu, Junhao; Tang, Xiaodong E-mail: xdtang@sist.ecnu.edu.cn

    2015-05-07

    Crystal structure and magnetic properties of multiferroic Y-type hexaferrites Ba{sub 0.5}Sr{sub 1.5}Zn{sub 2}(Fe{sub 1?x}Al{sub x}){sub 12}O{sub 22} (x?=?0, 0.04, 0.08, and 0.12) were investigated. The Z- and M-type impurity phases decrease with increasing Al content, and the pure phase samples can be obtained by modulating Al-doping. Lattice distortion exists in Al-doped samples due to the different radius of Al ion (0.535?) and Fe ion (0.645?). The microstructural morphologies show that the hexagonal shape grains can be observed in all the samples, and grain size decreases with increasing Al content. As for magnetic properties of Ba{sub 0.5}Sr{sub 1.5}Zn{sub 2}(Fe{sub 1?x}Al{sub x}){sub 12}O{sub 22}, there exist rich thermal- and field-driven magnetic phase transitions. Temperature dependence of zero-field cooling magnetization curves from 5?K to 800?K exhibit three magnetic phase transitions involving conical spin phase, proper-screw spin phase, ferromagnetic phase, and paramagnetic phase, which can be found in all the samples. Furthermore, the phase-transition temperatures can be modulated by varying Al content. In addition, four kinds of typical hysteresis loops are observed in pure phase sample at different temperatures, which reveal different magnetization processes of above-motioned magnetic spin structures. Typically, triple hysteresis loops in low magnetic field range from 0 to 0.5?T can be observed at 5?K, which suggests low-field driven magnetic phase transitions from conical spin order to proper-screw spin order and further to ferrimagnetic spin order occur. Furthermore, the coercive field (H{sub C}) and the saturation magnetization (M{sub S}) enhance with increasing Al content from x?=?0 to 0.08, and drop rapidly at x?=?0.12, which could be attribute to that in initial Al-doped process the pitch of spin helix increases and therefore magnetization enhances, but conical spin phase eventually collapses in higher-concentration Al-doping.

  10. MAGNETIC ROSSBY WAVES IN THE SOLAR TACHOCLINE AND RIEGER-TYPE PERIODICITIES

    SciTech Connect (OSTI)

    Zaqarashvili, Teimuraz V.; Carbonell, Marc; Oliver, Ramon; Ballester, Jose Luis E-mail: marc.carbonell@uib.e E-mail: joseluis.ballester@uib.e

    2010-02-01

    Apart from the eleven-year solar cycle, another periodicity around 155-160 days was discovered during solar cycle 21 in high-energy solar flares, and its presence in sunspot areas and strong magnetic flux has been also reported. This periodicity has an elusive and enigmatic character, since it usually appears only near the maxima of solar cycles, and seems to be related with a periodic emergence of strong magnetic flux at the solar surface. Therefore, it is probably connected with the tachocline, a thin layer located near the base of the solar convection zone, where a strong dynamo magnetic field is stored. We study the dynamics of Rossby waves in the tachocline in the presence of a toroidal magnetic field and latitudinal differential rotation. Our analysis shows that the magnetic Rossby waves are generally unstable and that the growth rates are sensitive to the magnetic field strength and to the latitudinal differential rotation parameters. Variation of the differential rotation and the magnetic field strength throughout the solar cycle enhance the growth rate of a particular harmonic in the upper part of the tachocline around the maximum of the solar cycle. This harmonic is symmetric with respect to the equator and has a period of 155-160 days. A rapid increase of the wave amplitude could give rise to a magnetic flux emergence leading to observed periodicities in solar activity indicators related to magnetic flux.

  11. Spinning a New Type of Magnetic Field | U.S. DOE Office of Science...

    Office of Science (SC) Website

    The Impact This demonstration reveals a new method to control the magnetization direction in the nanomagnets used in electronics, sensors, computer hard disks, and computer memory. ...

  12. Enrichment of magnetic alignment stimulated by {gamma}-radiation in core-shell type nanoparticle Mn-Zn ferrite

    SciTech Connect (OSTI)

    Naik, P. P.; Tangsali, R. B.; Sonaye, B.; Sugur, S.

    2013-02-05

    Core shell type nanoparticle Mn{sub x}Zn{sub 1-x}Fe{sub 2}O{sub 4} systems with x=0.55, 0.65 and 0.75 were prepared using autocombustion method. The systems were characterized using tools like XRD and IR for structure confirmation. Magnetic parameter measurements like Saturation magnetization and coercivity were obtained from hysteresis loop which exhibited a symmetry shift due to core shell nature of the nanoparticles. Nanoparticles of particle size between 21.2nm to 25.7nm were found to show 20 percent shrinkage after being radiated by the {gamma}-radiation. This is due to variation in the cation distribution which also affects the cell volume of the cubic cell. Lattice constant reduction observed is reflected in the magnetic properties of the samples. A considerable hike in the saturation magnetization of the samples was observed due to enrichment of magnetic alignment in the magnetic core of the particles. Samples under investigation were irradiated with gamma radiation from Co{sup 60} source for different time intervals.

  13. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    these structures are highly stable, very strong magnetic fields of around half a tesla (approximately one-third the field of the strongest permanent magnet) were previously...

  14. Magnetic Vortex Core Reversal by Low-Field Excitations

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

    Because these structures are highly stable, very strong magnetic fields of around half a tesla (approximately one-third the field of the strongest permanent magnet) were previously ...

  15. A POSSIBLE EVOLUTIONARY SCENARIO OF HIGHLY MAGNETIZED SUPER-CHANDRASEKHAR WHITE DWARFS: PROGENITORS OF PECULIAR TYPE Ia SUPERNOVAE

    SciTech Connect (OSTI)

    Das, Upasana; Mukhopadhyay, Banibrata; Rao, A. R. E-mail: bm@physics.iisc.ernet.in

    2013-04-10

    Several recently discovered peculiar Type Ia supernovae seem to demand an altogether new formation theory that might help explain the puzzling dissimilarities between them and the standard Type Ia supernovae. The most striking aspect of the observational analysis is the necessity of invoking super-Chandrasekhar white dwarfs having masses {approx}2.1-2.8 M{sub Sun }, M{sub Sun} being the mass of Sun, as their most probable progenitors. Strongly magnetized white dwarfs having super-Chandrasekhar masses have already been established as potential candidates for the progenitors of peculiar Type Ia supernovae. Owing to the Landau quantization of the underlying electron degenerate gas, theoretical results yielded the observationally inferred mass range. Here, we sketch a possible evolutionary scenario by which super-Chandrasekhar white dwarfs could be formed by accretion on to a commonly observed magnetized white dwarf, invoking the phenomenon of flux freezing. This opens multiple possible evolution scenarios ending in supernova explosions of super-Chandrasekhar white dwarfs having masses within the range stated above. We point out that our proposal has observational support, such as the recent discovery of a large number of magnetized white dwarfs by the Sloan Digital Sky Survey.

  16. Digital lock-in detection of site-specific magnetism in magnetic materials

    DOE Patents [OSTI]

    Haskel, Daniel; Lang, Jonathan C.; Srajer, George

    2008-07-22

    The polarization and diffraction characteristics of x-rays incident upon a magnetic material are manipulated to provide a desired magnetic sensitivity in the material. The contrast in diffracted intensity of opposite helicities of circularly polarized x-rays is measured to permit separation of magnetic signals by element type and by atomic environment. This allows for the direct probing of magnetic signals from elements of the same species in nonequivalent atomic environments to better understand the behavior and characteristics of permanent magnetic materials. By using known crystallographic information together with manipulation of the polarization of x-rays having energies tuned near element-specific electronic excitations and by detecting and comparing the incident and diffracted photons at the same frequency, more accurate magnetic measurements can be made over shorter observation periods.

  17. Kondo-type transport through a quantum dot under magnetic fields

    SciTech Connect (OSTI)

    Dong, Bing; Lei, X. L.

    2001-06-15

    In this paper, we investigate the Kondo correlation effects on linear and nonlinear transport in a quantum dot connected to reservoirs under finite magnetic fields, using the slave-boson mean field approach suggested by Kotliar and Ruckenstein [Phys. Rev. Lett. >57, 1362 (1986)]. A brief comparison between the present formulation and other slave-boson formulation is presented to justify this approach. The numerical results show that the linear conductance near electron-hole symmetry is suppressed by the application of the magnetic fields, but an anomalous enhancement is predicted in the nonsymmetry regime. The effect of external magnetic fields on the nonlinear differential conductances is discussed for the Kondo system. A significant reduction of the peak splitting is observed due to the strong Kondo correlation, which agrees well with experimental data.

  18. *Permanent Resident Alien: Yes No

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

    First Name: *Middle: *Last: *Gender (circle one): Male Female Is Visitor currently in the US? Yes No *Permanent Resident Alien: Yes No *Country of Citizenship: *Date of Birth (mm/dd/yyyy): *Country of Birth: *City of Birth: Affiliation or Company Info: *Institution or Company Name: Phone Number: Street (1): Fax Number: Street (2): E-mail Address: City: State: Zip Code: *Country of Employer: *Title or Position and Duties: First Name: Middle: Last: First Name: Middle: Last: First Name: Middle:

  19. Magnetic study of M-type doped barium hexaferrite nanocrystalline particles

    SciTech Connect (OSTI)

    Alsmadi, A. M.; Bsoul, I.; Mahmood, S. H.; Alnawashi, G.; Prokeš, K.; Siemensmeyer, K.; Klemke, B.; Nakotte, H.

    2013-12-28

    Co-Ti and Ru-Ti substituted barium ferrite nanocrystalline particles BaFe{sub 12−2x}Co{sub x}Ti{sub x}O{sub 19} with (0≤x≤1) and BaFe{sub 12−2x}Ru{sub x}Ti{sub x}O{sub 19} with (0≤x≤0.6) were prepared by ball milling method, and their magnetic properties and their temperature dependencies were studied. The zero-field-cooled (ZFC) and field-cooled (FC) processes were recorded at low magnetic fields and the ZFC curves displayed a broad peak at a temperature T{sub M}. In all samples under investigation, a clear irreversibility between the ZFC and FC curves was observed below room temperature, and this irreversibility disappeared above room temperature. These results were discussed within the framework of random particle assembly model and associated with the magnetic domain wall motion. The resistivity data showed some kind of a transition from insulator to perfect insulator around T{sub M}. At 2 K, the saturation magnetization slightly decreased and the coercivity dropped dramatically with increasing the Co-Ti concentration x. With Ru-Ti substitution, the saturation magnetization showed small variations, while the coercivity decreased monotonically, recording a reduction of about 73% at x = 0.6. These results were discussed in light of the single ion anisotropy model and the cationic distributions based on previously reported neutron diffraction data for the CoTi substituted system, and the results of our Mössbauer spectroscopy data for the RuTi substituted system.

  20. 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.

  1. The Microscopic Magnetic Properties of W-type Hexaferrite Powder Prepared by A Sol-Gel Route

    SciTech Connect (OSTI)

    Jotania, Rajshree; Chauhan, Chetna; Sharma, Pooja

    2010-12-01

    Magnetic particles of W-type barium-calcium hexaferrite (BaCa{sub 2}Fe{sub 16}O{sub 27}) have been synthesized using a Stearic acid gel route. The gel precursors were dried at 100 deg. C for 2 hrs and then calcinated at 650 deg. C, 750 deg. C, 850 deg. C and 950 deg. C for 4 hrs in a furnace and slowly cooled to room temperature in order to obtain barium-calcium hexaferrite particles. The microscopic magnetic properties of prepared samples studying using Moessbauer spectroscopy. Moessbauer spectra of all samples were recorded at room temperature. Mossbauer parameters like Isomer shift, Quadruple splitting etc. were calculated with respect to iron foil. Barium calcium hexaferrite samples heated at 650 deg. C, 750 deg. C, 850 deg. C show relaxation type Moessbauer spectra along with paramagnetic doublet. The intensity of paramagnetic doublet increases with temperature confirm the presence of ferrous ions in the samples, where as sample calcinated at 950 deg. C confirm the presence of ferrimagnetic phase with partial super paramagnetic nature of prepared hexaferrite sample.

  2. Unconventional magnetism in ThCr2Si2-type phosphides, La1 xNdxCo2P2

    SciTech Connect (OSTI)

    Thompson, Corey; Kovnir, Kirill; Garlea, Vasile O; Choi, E.; Zhou, Haidong; Shatruk, Michael

    2014-01-01

    Quaternary phases La1 xNdxCo2P2 (x = 0, 0.12, 0.25, 0.37, 0.50, 0.63, 0.75, 0.88, 1.0) have been synthesized from Sn flux to investigate the origins of drastic differences in properties between ferromagnetic LaCo2P2 and antiferromagnetic NdCo2P2. Powder and single-crystal X-ray diffraction indicate that all La1 xNdxCo2P2 samples are isostructural and crystallize in the ThCr2Si2 structure type. The unit cell parameters and volume change non-linearly with the Nd content (x), with the x < 0.50 10 samples being closer to LaCo2P2 and the ones with x > 0.50 being closer to NdCo2P2. These structural differences are also reflected in the magnetic behavior. The samples with lower Nd content are characterized by ferromagnetic ordering in the Co sublattice with the TC increasing from 132 K for x = 0 to 262 K for x = 0.50, while the samples with higher Nd content exhibit suppressed magnetization in the Co sublattice and canted antiferromagnetic ordering with TC ~ 270 K. Refinement of neutron powder 15 diffraction patterns for x = 0.50 and 0.75 reveals a gradual ordering of the Nd 4f moments under the influence of Co 3d moments below 100 K. At low temperatures and zero field, these samples exhibit antiferromagnetic ordering of both Nd and Co magnetic moments, but under applied field they demonstrate the stabilization of a ferrimagnetic state with antiparallel alignment of the 4f and 3d moments, as indicated by isothermal magnetization measurements. The re-entrant ferrimagnetic transition 20 is also observed in samples with x > 0.50 if the temperature is lowered below 5 K. The occurrence of this low-temperature magnetic transition was confirmed by alternating-current susceptibility measurements.

  3. 9977 TYPE B PACKAGING INTERNAL DATA COLLECTION FEASIBILITY TESTING - MAGNETIC FIELD COMMUNICATIONS

    SciTech Connect (OSTI)

    Shull, D.

    2012-06-18

    The objective of this report is to document the findings from proof-of-concept testing performed by the Savannah River National Laboratory (SRNL) R&D Engineering and Visible Assets, Inc. for the DOE Packaging Certification Program (PCP) to determine if RuBee (IEEE 1902.1) tags and readers could be used to provide a communication link from within a drum-style DOE certified Type B radioactive materials packaging. A Model 9977 Type B Packaging was used to test the read/write capability and range performance of a RuBee tag and reader. Testing was performed with the RuBee tags placed in various locations inside the packaging including inside the drum on the outside of the lid of the containment vessel and also inside of the containment vessel. This report documents the test methods and results. A path forward will also be recommended.

  4. U.S. Rare Earth Magnet Patents Table © 8-8-2016 page 1

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

    ... of Sheffield (Sheffield, Great Britain ) Magnetic materials and method of making ... articles Abstract An article comprising first and second bodies of permanent magnet ...

  5. Simulation of a gigawatt level Ku-band overmoded Cerenkov type oscillator operated at low guiding magnetic field

    SciTech Connect (OSTI)

    Zhang, Hua; Shu, Ting Ju, Jinchuan; Wu, Dapeng

    2014-03-15

    We present the simulation results of a Ku-band overmoded Cerenkov type high power microwave oscillator. A guiding magnetic field as low as 0.6?T has been operated in the device. Overmoded slow wave structures with gradually tapered vanes are used in order to increase power capacity and the efficiency of beam-wave interaction. The drift cavity is adopted to enhance the beam-wave interaction of the device. After numerical optimization, the designed generator with an output microwave power of 1.2?GW, a frequency of 13.8 GHz, and a power conversion efficiency as high as 38% can be achieved, when the diode voltage and current are, respectively, 540?kV and 5.8?kA. The power compositions of TM{sub 0n} modes of the output microwave have been analyzed, the results of which show that TM{sub 01} mode takes over almost 95% of the power proportion.

  6. Equilibrium intermediate-state patterns in a type-I superconducting slab in an arbitrarily oriented applied magnetic field

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

    Clem, John; Prozorov, Ruslan; Wijngaarden, Rinke J.

    2013-09-04

    The equilibrium topology of superconducting and normal domains in flat type-I superconductors is investigated. Important improvements with respect to previous work are that (1) the energy of the external magnetic field, as deformed by the presence of superconducting domains, is calculated in the same way for three different topologies and (2) calculations are made for arbitrary orientation of the applied field. A phase diagram is presented for the minimum-energy topology as a function of applied field magnitude and angle. For small (large) applied fields, normal (superconducting) tubes are found, while for intermediate fields, parallel domains have a lower energy. Themore » range of field magnitudes for which the superconducting-tubes structure is favored shrinks when the field is more in-plane oriented.« less

  7. The effects of Co-Ti co-doping on the magnetic, electrical, and magnetodielectric behaviors of M-type barium hexaferrites

    SciTech Connect (OSTI)

    Guan, Yujie; Lin, Yuanbin; Zou, Liangying; Miao, Qing; Zeng, Min; Gao, Xingsen; Liu, Zhongwu; Liu, Junming

    2013-12-15

    Magnetic, electrical and magnetodielectric properties have been studied in Co-Ti co-doped M-type hexaferrite BaCo{sub x}Ti{sub x}Fe{sub 12-2x}O{sub 19} (x = 0 ∼ 4). With the incorporation of Co-Ti, both their ferromagnetic magnetization and coercivity have been greatly changed. The temperature dependent magnetization curve shows a apparent hump at around 420 K, likely in association with more complicated cycloidal spin ordering, which is closely related to ferroelectric polarization. Interestingly, a significantly enhancement in resistivity (∼3 orders in magnitude) can be obtained in co-doped samples (x > 2), which is beneficial for magnetoelectric properties. The magnetoelectric effect were examined by dielectric tunibility under external magnetic field, which shows apparent tunability up to ∼−3% for sample with x = 2 at 1T magnetic field, further supporting it is a room temperature single phase mutliferroic material.

  8. Magnetic bearing element with adjustable stiffness

    DOE Patents [OSTI]

    Post, Richard F

    2013-11-12

    A compact magnetic bearing element is provided which is made of permanent magnet discs configured to be capable of the adjustment of the bearing stiffness and levitation force over a wide range.

  9. Spomenka Kobe, Jozef Stefan Institut, Rare Earth Magnets in Europe...

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

    Hadjipanayis, Chairman, Department of Physics and Astronomy, University of Delaware, Moving Beyond Neodymium-Iron Permanent Magnets for EV Motors Iowa lab gets critical materials...

  10. Two Keggin-type heteropolytungstates with transition metal as a central atom: Crystal structure and magnetic study with 2D-IR correlation spectroscopy

    SciTech Connect (OSTI)

    Chai, Feng [Department of Chemistry, Fuzhou University, Fuzhou 350108 (China); Chen, YiPing, E-mail: ypchen007@sina.com [Department of Chemistry, Fuzhou University, Fuzhou 350108 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); You, ZhuChai; Xia, ZeMin; Ge, SuZhi; Sun, YanQiong; Huang, BiHua [Department of Chemistry, Fuzhou University, Fuzhou 350108 (China)

    2013-06-01

    Two Keggin-type heteropolytungstates, [Co(phen)?]?[CoW??O??]9H?O 1 (phen=1,10-phenanthroline) and [Fe(phen)?]?[FeW??O??]H?OH?O 2, have been synthesized via the hydrothermal technique and characterized by single crystal X-ray diffraction analyses, IR, XPS, TG analysis, UVDRS, XRD, thermal-dependent and magnetic-dependent 2D-COS IR (two-dimensional infrared correlation spectroscopy). Crystal structure analysis reveals that the polyanions in compound 1 are linked into 3D supramolecule through hydrogen bonding interactions between lattice water molecules and terminal oxygen atoms of polyanion units, and [Co(phen)?]? cations distributed in the polyanion framework with many hydrogen bonding interactions. The XPS spectra indicate that all the Co atoms in 1 are +2 oxidation state, the Fe atoms in 2 existing with +2 and +3 mixed oxidation states. - Graphical abstract: The magnetic-dependent synchronous 2D correlation IR spectra of 1 (a), 2 (b) over 050 mT in the range of 6001000 cm?, the obvious response indicate two Keggin polyanions skeleton susceptible to applied magnetic field. Highlights: Two Keggin-type heteropolytungstates with transition metal as a central atom has been obtained. Compound 1 forms into 3D supramolecular architecture through hydrogen bonding between water molecules and polyanions. Magnetic-dependent 2D-IR correlation spectroscopy was introduced to discuss the magnetism of polyoxometalate.

  11. 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.

  12. A New Class of Switched Reluctance Motors without Permanent Magnets...

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

    0 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C. ape020burress2010p...

  13. Direct control of air gap flux in permanent magnet machines

    DOE Patents [OSTI]

    Hsu, John S.

    2000-01-01

    A method and apparatus for field weakening in PM machines uses field weakening coils (35, 44, 45, 71, 72) to produce flux in one or more stators (34, 49, 63, 64), including a flux which counters flux normally produced in air gaps between the stator(s) (34, 49, 63, 64) and the rotor (20, 21, 41, 61) which carries the PM poles. Several modes of operation are introduced depending on the magnitude and polarity of current in the field weakening coils (35, 44, 45, 71, 72). The invention is particularly useful for, but not limited to, the electric vehicle drives and PM generators.

  14. Voltage Regulation Using a Permanent Magnet Synchronous Generator...

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

    ... A PMSG has the advantage of higher efficiency and ... impedance of a weak grid connection limits the power transmission. ... R and jX represent the transmission line impedance. Note ...

  15. Permanent Magnet Synchronous Condenser for Wind Power Plant Grid...

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

    for Wind Power Plant Grid Connection Support Preprint P. Hsu San Jose State University E. Muljadi National Renewable Energy Laboratory To be presented at the IEEE 2015 9 th ...

  16. Novel Flux Coupling Machine without Permanent Magnets - U Machine |

    Broader source: Energy.gov (indexed) [DOE]

    | Department of Energy Energy Conversion Equipment for Low Temperatures Geothermal Resources presentation at the April 2013 peer review meeting held in Denver, Colorado. novel_energy_conversion_equipment_low_peer2013.pdf (582.04 KB) More Documents & Publications Novel Energy Conversion Equipment for Low Temperature Geothermal Resources City of Eagan …Civic Ice Arena Renovation Canby Cascaded Geothermal Project Phase 1 Feasibility

    A new thermoelectric clothes dryer being developed by

  17. Permanent Magnet Development for Automotive Traction Motors | Department of

    Broader source: Energy.gov (indexed) [DOE]

    7.601 August 2016 ______________________________________________________________________________ 1 Performance-Based Services Acquisition [Reference: Public Law 106-398, § 821, FAR 37.6] 1.0 Summary of Latest Changes This update: (1) changes the chapter number from 37.2 to 37.601 to coincide with the FAR, (2) updates references, and (3) includes administrative changes. 2.0 Discussion This chapter supplements other more primary acquisition regulations and policies contained in the references

  18. A New Class of Switched Reluctance Motors without Permanent Magnets

    Broader source: Energy.gov [DOE]

    2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C.

  19. A New Class of Switched Reluctance Motors without Permanent Magnets

    Broader source: Energy.gov [DOE]

    2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation

  20. Permanent Magnet Synchronous Condenser with Solid State Excitation...

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

    State University E. Muljadi National Renewable Energy Laboratory Z. Wu and W. Gao University ... be achieved with the open-loop control law in (4), where Var cmd is the commanded ...

  1. THE POSSIBLE ROLE OF CORONAL STREAMERS AS MAGNETICALLY CLOSED STRUCTURES IN SHOCK-INDUCED ENERGETIC ELECTRONS AND METRIC TYPE II RADIO BURSTS

    SciTech Connect (OSTI)

    Kong, Xiangliang; Chen, Yao; Feng, Shiwei; Wang, Bing; Du, Guohui; Guo, Fan; Li, Gang

    2015-01-10

    Two solar typeII radio bursts, separated by ?24 hr in time, are examined together. Both events are associated with coronal mass ejections (CMEs) erupting from the same active region (NOAA 11176) beneath a well-observed helmet streamer. We find that the typeII emissions in both events ended once the CME/shock fronts passed the white-light streamer tip, which is presumably the magnetic cusp of the streamer. This leads us to conjecture that the closed magnetic arcades of the streamer may play a role in electron acceleration and typeII excitation at coronal shocks. To examine such a conjecture, we conduct a test-particle simulation for electron dynamics within a large-scale partially closed streamer magnetic configuration swept by a coronal shock. We find that the closed field lines play the role of an electron trap via which the electrons are sent back to the shock front multiple times and therefore accelerated to high energies by the shock. Electrons with an initial energy of 300 eV can be accelerated to tens of keV concentrating at the loop apex close to the shock front with a counter-streaming distribution at most locations. These electrons are energetic enough to excite Langmuir waves and radio bursts. Considering the fact that most solar eruptions originate from closed field regions, we suggest that the scenario may be important for the generation of more metric typeIIs. This study also provides an explanation of the general ending frequencies of metric typeIIs at or above 20-30 MHz and the disconnection issue between metric and interplanetary typeIIs.

  2. Magnetic multipole redirector of moving plasmas

    DOE Patents [OSTI]

    Crow, James T.; Mowrer, Gary R.

    1999-01-01

    A method and apparatus for redirecting moving plasma streams using a multiple array of magnetic field generators (e.g., permanent magnets or current bearing wires). Alternate rows of the array have opposite magnetic field directions. A fine wire mesh may be employed to focus as well as redirect the plasma.

  3. When Do Commercial Reactors Permanently Shut Down?

    Reports and Publications (EIA)

    2011-01-01

    For those wishing to obtain current data, the following resources are available: U.S. reactors, go to the Energy Information Administration's nuclear reactor shutdown list. (Note: As of April 30, 2010, the last U.S. reactor to permanently shut down was Big Rock Point in 1997.) Foreign Reactors, go to the Power Reactor Information System (PRIS) on the International Atomic Energy Agency's website.

  4. Gating of Permanent Molds for Aluminum Casting (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    pattern and heat flow behavior in permanent mold castings. Equipment and procedure for real time X-Ray radiography of molten aluminum flow into permanent molds have been developed. ...

  5. 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.

  6. U.S. Rare Earth Magnet Patents Table 1-5-2016 page 1

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

    machining methods. What is claimed is: 1. A method for extrusion manufacture of multi-layer structure with a ring permanent magnet processmethod comprising the steps...

  7. 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.

  8. Trading permanent and temporary carbon emissions credits

    SciTech Connect (OSTI)

    Marland, Gregg; Marland, Eric

    2009-08-01

    In this issue of Climatic Change, Van Kooten (2009) addresses an issue that has bedeviled negotiators since the drafting stage of the Kyoto Protocol. If we accept that increasing withdrawals of carbon dioxide from the atmpshere has the same net impact on the climate system as reducing emissions of carbon dioxide to the atmosphere, how do we design a system that allows trading of one for the other? As van Kooten expresses the challenge: 'The problem is that emissions reduction and carbon sequestration, while opposite sides of the same coin in some sense, are not directly comparable, thereby inhibiting their trade in carbon markets.' He explains: 'The difficulty centers on the length of time that mitigation strategies without CO{sub 2} from entering the atmosphere - the duration problem.' While reducing emissions of CO{sub 2} represents an essentially permanent benefit for the atmosphere, capturing CO{sub 2} that has been produced (whether capture is from the atmosphere or directly from, for example, the exhaust from power plants) there is the challenge of storing the carbon adn the risk that it will yet escape to the atmosphere. Permanent benefit to the atmosphere is often not assured for carbon sequestration activities. This is especially true if the carbon is taken up and stored in the biosphere - e.g. in forest trees or agricultural soils.

  9. Structure and magnetic properties of Ce₃(Ni/Al/Ga)₁₁—A new phase with the La₃Al₁₁ structure type

    SciTech Connect (OSTI)

    Janka, Oliver; Shang, Tian; Baumbach, Ryan E.; Bauer, Eric D.; Thompson, Joe D.; Kauzlarich, Susan M.

    2015-03-01

    Single crystals of Ce₃(Ni/Al/Ga)₁₁ were obtained from an Al flux reaction. Single crystals of the title compound crystallizing in the orthorhombic space group Immm (No. 71, Z = 2) with a = 436.38(14), b = 1004.5(3) and c = 1293.4(4) pm. This is a standardized unit cell of the previously published La₃Al₁₁ structure type. Wavelength dispersive microprobe provides the composition of Ce₃.₁₁₍₁₎Ni₀.₀₃₍₁₎Al₈.₉₅₍₁₎Ga₁.₉₀₍₁₎. Single crystal refinement provides the composition Ce₃Ni₀.₀₈Al₉.₁₃Ga₁.₇₈ with substitution of the Ni and Ga on the Al1 and Al4 sites with the Al2 and Al3 solely occupied by Al. Magnetic susceptibility measurements reveal antiferromagnetic ordering with TN = 4.8 K and there is no evidence for a ferromagnetic ordering that has been reported for Ce₃Al₁₁. The effective magnetic moment was found to be μeff = 1.9μB/Ce, which is lower than the expected value for trivalent Ce (2.54μB/Ce).

  10. Structure and magnetic properties of Ce₃(Ni/Al/Ga)₁₁—A new phase with the La₃Al₁₁ structure type

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

    Janka, Oliver; Shang, Tian; Baumbach, Ryan E.; Bauer, Eric D.; Thompson, Joe D.; Kauzlarich, Susan M.

    2015-03-01

    Single crystals of Ce₃(Ni/Al/Ga)₁₁ were obtained from an Al flux reaction. Single crystals of the title compound crystallizing in the orthorhombic space group Immm (No. 71, Z = 2) with a = 436.38(14), b = 1004.5(3) and c = 1293.4(4) pm. This is a standardized unit cell of the previously published La₃Al₁₁ structure type. Wavelength dispersive microprobe provides the composition of Ce₃.₁₁₍₁₎Ni₀.₀₃₍₁₎Al₈.₉₅₍₁₎Ga₁.₉₀₍₁₎. Single crystal refinement provides the composition Ce₃Ni₀.₀₈Al₉.₁₃Ga₁.₇₈ with substitution of the Ni and Ga on the Al1 and Al4 sites with the Al2 and Al3 solely occupied by Al. Magnetic susceptibility measurements reveal antiferromagnetic ordering with TN =more » 4.8 K and there is no evidence for a ferromagnetic ordering that has been reported for Ce₃Al₁₁. The effective magnetic moment was found to be μeff = 1.9μB/Ce, which is lower than the expected value for trivalent Ce (2.54μB/Ce).« less

  11. Permanent Cortical Blindness After Bronchial Artery Embolization

    SciTech Connect (OSTI)

    Doorn, Colette S. van De Boo, Diederick W.; Weersink, Els J. M.; Delden, Otto M. van Reekers, Jim A. Lienden, Krijn P. van

    2013-12-15

    A 35-year-old female with a known medical history of cystic fibrosis was admitted to our institution for massive hemoptysis. CTA depicted a hypertrophied bronchial artery to the right upper lobe and showed signs of recent bleeding at that location. Bronchial artery embolization (BAE) was performed with gelfoam slurry, because pronounced shunting to the pulmonary artery was present. Immediately after BAE, the patient developed bilateral cortical blindness. Control angiography showed an initially not opacified anastomosis between the embolized bronchial artery and the right subclavian artery, near to the origin of the right vertebral artery. Cessation of outflow in the bronchial circulation reversed the flow through the anastomosis and allowed for spill of embolization material into the posterior circulation. Unfortunately the cortical blindness presented was permanent.

  12. Comparison of conventional and novel quadrupole drift tube magnets inspired by Klaus Halbach

    SciTech Connect (OSTI)

    Feinberg, B.

    1995-02-01

    Quadrupole drift tube magnets for a heavy-ion linac provide a demanding application of magnet technology. A comparison is made of three different solutions to the problem of providing an adjustable high-field-strength quadrupole magnet in a small volume. A conventional tape-wound electromagnet quadrupole magnet (conventional) is compared with an adjustable permanent-magnet/iron quadrupole magnet (hybrid) and a laced permanent-magnet/iron/electromagnet (laced). Data is presented from magnets constructed for the SuperHILAC heavy-ion linear accelerator, and conclusions are drawn for various applications.

  13. Evaluation of Options for Permanent Geologic Disposal of Spent...

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

    and permanent disposal of spentnuclear fuel (SNF) and high-level radioactive waste (HLW) ... engineering, and materials safeguards and security, and regulatory considerations. ...

  14. Mold Materials For Permanent Molding of Aluminum Alloys (Technical...

    Office of Scientific and Technical Information (OSTI)

    Title: Mold Materials For Permanent Molding of Aluminum Alloys A test that involves ... This test has been employed to determine the relative thermal fatigue resistance of ...

  15. POLICY GUIDANCE MEMORANDUM #23 Permanent and Nonpermanent Positions...

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

    PDF icon POLICY GUIDANCE MEMORANDUM 23 Permanent and Nonpermanent Positions, Appointments, & CHRIS Codes Responsible Contacts Tiffany Wheeler Human Resources Specialist E-mail ...

  16. Heading off the permanent oil crisis

    SciTech Connect (OSTI)

    MacKenzie, J.J.

    1996-11-01

    The 1996 spike in gasoline prices was not a signal of any fundamental worldwide shortage of crude oil. But based on a review of many studies of recoverable crude oil that have been published since the 1950s, it looks as though such a shortfall is now within sight. With world demand for oil growing at 2 percent per year, global production is likely to peak between the years 2007 and 2014. As this time approaches, we can expect prices to rise markedly and, most likely, permanently. Policy changes are needed now to ease the transition to high-priced oil. Oil production will continue, though at a declining rate, for many decades after its peak, and there are enormous amounts of coal, oil sands, heavy oil, and oil shales worldwide that could be used to produce liquid or gaseous substitutes for crude oil, albeit at higher prices. But the facilities for making such synthetic fuels are costly to build and environmentally damaging to operate, and their use would substantially increase carbon dioxide emissions (compared to emissions from products made from conventional crude oil). This paper examines ways of heading of the impending oil crisis. 8 refs., 3 figs.

  17. The search for permanent electric dipole moments

    SciTech Connect (OSTI)

    Kirch, Klaus

    2013-02-13

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

  18. Fluorescent lamp with static magnetic field generating means

    DOE Patents [OSTI]

    Moskowitz, P.E.; Maya, J.

    1987-09-08

    A fluorescent lamp wherein magnetic field generating means (e.g., permanent magnets) are utilized to generate a static magnetic field across the respective electrode structures of the lamp such that maximum field strength is located at the electrode's filament. An increase in efficacy during operation has been observed. 2 figs.

  19. Fluorescent lamp with static magnetic field generating means

    DOE Patents [OSTI]

    Moskowitz, Philip E.; Maya, Jakob

    1987-01-01

    A fluorescent lamp wherein magnetic field generating means (e.g., permanent magnets) are utilized to generate a static magnetic field across the respective electrode structures of the lamp such that maximum field strength is located at the electrode's filament. An increase in efficacy during operation has been observed.

  20. EuTZn (T=Pd, Pt, Au) with TiNiSi-type structure-Magnetic properties and {sup 151}Eu Moessbauer spectroscopy

    SciTech Connect (OSTI)

    Mishra, Trinath; Hermes, Wilfried; Harmening, Thomas; Eul, Matthias; Poettgen, Rainer

    2009-09-15

    The europium compounds EuTZn (T=Pd, Pt, Au) were synthesized from the elements in sealed tantalum tubes in an induction furnace. These intermetallics crystallize with the orthorhombic TiNiSi-type structure, space group Pnma. The structures were investigated by X-ray diffraction on powders and single crystals: a=732.3(2), b=448.5(2), c=787.7(2) pm, R{sub 1}/wR{sub 2}=0.0400/0.0594, 565 F{sup 2} values for EuPdZn, a=727.8(3), b=443.7(1), c=781.7(3) pm, R{sub 1}/wR{sub 2}=0.0605/0.0866, 573 F{sup 2} values for EuPtZn, and a=747.4(2), b=465.8(2), c=789.1(4) pm, R{sub 1}/wR{sub 2}=0.0351/0.0590, 658 F{sup 2} values for EuAuZn, with 20 variables per refinement. Together the T and zinc atoms build up three-dimensional [TZn] networks with short T-Zn distances. The EuTZn compounds show Curie-Weiss behavior in the temperature range from 75 to 300 K with mu{sub eff}=7.97(1), 7.70(1), and 7.94(1) mu{sub B}/Eu atom and theta{sub P}=18.6(1), 34.9(1), and 55.5(1) K for T=Pd, Pt, and Au, respectively, indicating divalent europium. Antiferromagntic ordering was detected at 15.1(3) K for EuPdZn and canted ferromagnetic ordering at 21.2(3) and 51.1(3) K for EuPtZn and EuAuZn. {sup 151}Eu Moessbauer spectroscopic measurements confirm the divalent nature of the europium atoms by isomer shift values ranging from -8.22(8) (EuPtZn) to -9.23(2) mm/s (EuAuZn). At 4.2 K full magnetic hyperfine field splitting is observed in all three compounds due to magnetic ordering of the europium magnetic moments. - Graphical abstract: Europium coordination in EuPdZn, EuPtZn, and EuAuZn.

  1. SrAgZn and EuAgZn with KHg{sub 2}-type structure—Structure, magnetic properties, and {sup 151}Eu Mössbauer spectroscopy

    SciTech Connect (OSTI)

    Gerke, Birgit; Rodewald, Ute Ch.; Niehaus, Oliver; Pöttgen, Rainer

    2013-07-15

    Samples of SrAgZn and EuAgZn were synthesized by reaction of the elements in sealed tantalum crucibles. Both structures were refined on the basis of single crystal X-ray diffractometer data: KHg{sub 2}-type, Imma, a=476.7(1), b=780.9(2), c=810.1(2) pm, R{sub 1}/wR{sub 2}=0.0189/0.0119, 381 F² values for SrAg{sub 1.12}Zn{sub 0.88} and a=474.43(9), b=760.8(2), c=799.0(2) pm, R{sub 1}/wR{sub 2}=0.0226/0.0483, 370 F² values for EuAg{sub 1.17}Zn{sub 0.83} with 13 variables per refinement. Silver and zinc are randomly distributed on the Hg position and build up three-dimensional networks. EuAgZn shows ferromagnetic ordering at 29(1) K. In the temperature range from 75 to 300 K the sample shows Curie–Weiss behaviour with μ{sub eff}=7.87(1) μ{sub B}/Eu atom and θ{sub P}=37.1(1) K, indicating divalent europium. {sup 151}Eu Mössbauer spectroscopic measurements confirmed the divalent state with an isomer shift of −9.31 mm/s at 78 K. Temperature dependent {sup 151}Eu data show first magnetic hyperfine field splitting at 25 K and a saturated magnetization of 17 T at 5.2 K. The temperature dependence can be described by an S=7/2 Brillouin function. - Graphical abstract: The near neighbor coordination of the strontium and europium atoms in SrAg{sub 1.12}Zn{sub 0.88}, EuAg{sub 1.17}Zn{sub 0.83}, and EuAuZn. - Highlights: • Synthesis of new intermetallic zinc compounds SrAgZn and EuAgZn. • Ferromagnetic ordering of EuAgZn at 29 K. • Magnetic hyperfine field splitting in the {sup 151}Eu Mössbauer spectrum.

  2. Research on ambient temperature passive magnetic bearings at the Lawrence Livermore National Laboratory

    SciTech Connect (OSTI)

    Post, R.F.; Ryitov, D.D.` Smith, J.R.; Tung, L.S.

    1997-04-01

    Research performed at the Lawrence Livermore National Laboratory on the equilibrium and stability of a new class of ambient-temperature passive bearing systems is described. The basic concepts involved are: (1) Stability of the rotating system is only achieved in the rotating state. That is, disengaging mechanical systems are used to insure stable levitation at rest (when Earnshaw`s theorem applies). (2) Stable levitation by passive magnetic elements can be achieved if the vector sum of the force derivatives of the several elements of the system is net negative (i.e. restoring) for axial, transverse, and tilt-type perturbations from equilibrium. To satisfy the requirements of (2) using only permanent magnet elements we have employed periodic ``Halbach arrays.`` These interact with passive inductive loaded circuits and act as stabilizers, with the primary forces arising from axially symmetric permanent-magnet elements. Stabilizers and other elements needed to create compact passive magnetic bearing systems have been constructed. Novel passive means for stabilizing classes of rotor-dynamic instabilities in such systems have also been investigated.

  3. Combined passive magnetic bearing element and vibration damper

    DOE Patents [OSTI]

    Post, Richard F.

    2001-01-01

    A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium and dampen transversely directed vibrations. Mechanical stabilizers are provided to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. In a improvement over U.S. Pat. No. 5,495,221, a magnetic bearing element is combined with a vibration damping element to provide a single upper stationary dual-function element. The magnetic forces exerted by such an element, enhances levitation of the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations, and suppresses the effects of unbalance or inhibits the onset of whirl-type rotor-dynamic instabilities. Concurrently, this equilibrium is made stable against displacement-dependent drag forces of the rotating object from its equilibrium position.

  4. WIPP Begins Preliminary Work on New Permanent Ventilation System

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

    July 28, 2016 WIPP Begins Preliminary Work on New Permanent Ventilation System The geotechnical investigation necessary for construction of a new Permanent Ventilation System (PVS), including a new filter building and a new exhaust shaft, is underway at the Waste Isolation Pilot Plant (WIPP). Investigation activities include drilling multiple bore holes and the collection of core samples at various depths. Analysis of the core samples will provide information for the building design team on

  5. High performance hybrid magnetic structure for biotechnology applications

    DOE Patents [OSTI]

    Humphries, David E.; Pollard, Martin J.; Elkin, Christopher J.

    2006-12-12

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides for separation and other biotechnology applications involving holding, manipulation, or separation of magnetic or magnetizable molecular structures and targets. Also disclosed are: a method of assembling the hybrid magnetic plates, a high throughput protocol featuring the hybrid magnetic structure, and other embodiments of the ferromagnetic pole shape, attachment and adapter interfaces for adapting the use of the hybrid magnetic structure for use with liquid handling and other robots for use in high throughput processes.

  6. A small-bore high-field superconducting quadrupole magnet

    SciTech Connect (OSTI)

    Barlow, D.B.; Kraus, R.H.; Lobb, C.T.; Menzel, M.T. ); Walstrom, P.L. )

    1990-01-01

    A prototype superconducting quadrupole magnet was designed and built for use in superconducting coupled-cavity linacs where the use of permanent magnets is ruled out by consideration of trapped flux losses. The magnet has a clear bore diameter of 1.8 cm and outside diameter of 11 cm and length of 11 cm. The magnet was operated at a temperature of 4.2 K and obtained a peak quadrupole field gradient of 320 T/m.

  7. 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)

  8. Magnetic switch for reactor control rod. [LMFBR

    DOE Patents [OSTI]

    Germer, J.H.

    1982-09-30

    A magnetic reed switch assembly is described for activating an electromagnetic grapple utilized to hold a control rod in position above a reactor core. In normal operation the magnetic field of a permanent magnet is short-circuited by a magnetic shunt, diverting the magnetic field away from the reed switch. The magnetic shunt is made of a material having a Curie-point at the desired release temperature. Above that temperature the material loses its ferromagnetic properties, and the magnetic path is diverted to the reed switch which closes and short-circuits the control circuit for the control rod electro-magnetic grapple which allows the control rod to drop into the reactor core for controlling the reactivity of the core.

  9. POLICY GUIDANCE MEMORANDUM #23 Permanent and Nonpermanent Positions, Appointments, & CHRIS Codes

    Broader source: Energy.gov [DOE]

    Policy Guidance Memorandum #23 - DOE Guidance – Permanent and Nonpermanent Positions, Appointments, & CHRIS Codes

  10. Magnetic transit-time flowmeter

    DOE Patents [OSTI]

    Forster, George A.

    1976-07-06

    The flow rate of a conducting fluid in a stream is determined by disposing two permanent-magnet flowmeters in the stream, one downstream of the other. Flow of the conducting fluid causes the generation of both d-c and a-c electrical signals, the a-c comprising flow noise. Measurement of the time delay between similarities in the a-c signals by cross-correlation methods provides a measure of the rate of flow of the fluid.

  11. High performance hybrid magnetic structure for biotechnology applications

    DOE Patents [OSTI]

    Humphries, David E.; Pollard, Martin J.; Elkin, Christopher J.

    2009-02-03

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetic or magnetizable molecular structures and targets. Also disclosed are further improvements to aspects of the hybrid magnetic structure, including additional elements and for adapting the use of the hybrid magnetic structure for use in biotechnology and high throughput processes.

  12. High performance hybrid magnetic structure for biotechnology applications

    DOE Patents [OSTI]

    Humphries, David E; Pollard, Martin J; Elkin, Christopher J

    2005-10-11

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetizable molecular structures and targets. Also disclosed are: a method of assembling the hybrid magnetic plates, a high throughput protocol featuring the hybrid magnetic structure, and other embodiments of the ferromagnetic pole shape, attachment and adapter interfaces for adapting the use of the hybrid magnetic structure for use with liquid handling and other robots for use in high throughput processes.

  13. Permanent laser conditioning of thin film optical materials

    DOE Patents [OSTI]

    Wolfe, C. Robert; Kozlowski, Mark R.; Campbell, John H.; Staggs, Michael; Rainer, Frank

    1995-01-01

    The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold.

  14. Permanent laser conditioning of thin film optical materials

    DOE Patents [OSTI]

    Wolfe, C.R.; Kozlowski, M.R.; Campbell, J.H.; Staggs, M.; Rainer, F.

    1995-12-05

    The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold. 9 figs.

  15. Permanent Closure of the TAN-664 Underground Storage Tank

    SciTech Connect (OSTI)

    Bradley K. Griffith

    2011-12-01

    This closure package documents the site assessment and permanent closure of the TAN-664 gasoline underground storage tank in accordance with the regulatory requirements established in 40 CFR 280.71, 'Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks: Out-of-Service UST Systems and Closure.'

  16. Magnetic switch for reactor control rod

    DOE Patents [OSTI]

    Germer, John H.

    1986-01-01

    A magnetic reed switch assembly for activating an electromagnetic grapple utilized to hold a control rod in position above a reactor core. In normal operation the magnetic field of a permanent magnet is short-circuited by a magnetic shunt, diverting the magnetic field away from the reed switch. The magnetic shunt is made of a material having a Curie-point at the desired release temperature. Above that temperature the material loses its ferromagnetic properties, and the magnetic path is diverted to the reed switch which closes and short-circuits the control circuit for the control rod electromagnetic grapple which allows the control rod to drop into the reactor core for controlling the reactivity of the core.

  17. Types of Lighting in Commercial Buildings - Lighting Types

    U.S. Energy Information Administration (EIA) Indexed Site

    is termed fluorescence). A ballast is required to regulate and control the current and voltage. Two types of ballasts are used, magnetic and electronic. Electronic ballasts have...

  18. Magnetic Material for PM Motors | Department of Energy

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

    Magnetic Material for PM Motors Magnetic Material for PM Motors 2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. pmp_23_anderson.pdf (2.23 MB) More Documents & Publications Permanent Magnet Development for Automotive Traction Motors Vehicle Technologies Office: 2009 Propulsion Materials R&D Annual Progress Report Iver Anderson, Division of Materials Sciences and Engineering, The Ames Laboratory,

  19. Method of making fully dense anisotropic high energy magnets

    SciTech Connect (OSTI)

    Chatterjee, D.K.

    1990-01-09

    This patent describes a method of making anisotropic permanent magnets. It comprises extruding a rare earth, transition metal, magnetic alloy together with an oxygen-getter material at a temperature of from about 600{degrees} C to about 1000{degrees} C at an extrusion ratio of from about 10:1 to about 26:1 the rare earth, transition metal, magnetic alloy and the oxygen-getter material being disposed within an extrusion zone in Separate and discrete locations.

  20. Determination of prescription dose for Cs-131 permanent implants using the BED formalism including resensitization correction

    SciTech Connect (OSTI)

    Luo, Wei Molloy, Janelle; Aryal, Prakash; Feddock, Jonathan; Randall, Marcus

    2014-02-15

    Purpose: The current widely used biological equivalent dose (BED) formalism for permanent implants is based on the linear-quadratic model that includes cell repair and repopulation but not resensitization (redistribution and reoxygenation). The authors propose a BED formalism that includes all the four biological effects (4Rs), and the authors propose how it can be used to calculate appropriate prescription doses for permanent implants with Cs-131. Methods: A resensitization correction was added to the BED calculation for permanent implants to account for 4Rs. Using the same BED, the prescription doses with Au-198, I-125, and Pd-103 were converted to the isoeffective Cs-131 prescription doses. The conversion factor F, ratio of the Cs-131 dose to the equivalent dose with the other reference isotope (F{sub r}: with resensitization, F{sub n}: without resensitization), was thus derived and used for actual prescription. Different values of biological parameters such as α, β, and relative biological effectiveness for different types of tumors were used for the calculation. Results: Prescription doses with I-125, Pd-103, and Au-198 ranging from 10 to 160 Gy were converted into prescription doses with Cs-131. The difference in dose conversion factors with (F{sub r}) and without (F{sub n}) resensitization was significant but varied with different isotopes and different types of tumors. The conversion factors also varied with different doses. For I-125, the average values of F{sub r}/F{sub n} were 0.51/0.46, for fast growing tumors, and 0.88/0.77 for slow growing tumors. For Pd-103, the average values of F{sub r}/F{sub n} were 1.25/1.15 for fast growing tumors, and 1.28/1.22 for slow growing tumors. For Au-198, the average values of F{sub r}/F{sub n} were 1.08/1.25 for fast growing tumors, and 1.00/1.06 for slow growing tumors. Using the biological parameters for the HeLa/C4-I cells, the averaged value of F{sub r} was 1.07/1.11 (rounded to 1.1), and the averaged value of F

  1. Perpendicularly magnetized {tau}-MnAl (001) thin films epitaxied on GaAs

    SciTech Connect (OSTI)

    Nie, S. H.; Zhu, L. J.; Lu, J.; Pan, D.; Wang, H. L.; Yu, X. Z.; Xiao, J. X.; Zhao, J. H.

    2013-04-15

    Perpendicularly magnetized {tau}-MnAl films have been epitaxied on GaAs (001) by molecular-beam epitaxy. Crystalline quality and magnetic properties of the samples were strongly dependent on growth temperature. The highest coercivity of 10.7 kOe, saturation magnetization of 361.4 emu/cm{sup 3}, perpendicular magnetic anisotropy constant of 13.65 Merg/cm{sup 3}, and magnetic energy product of 4.44 MGOe were achieved. These tunable magnetic properties make MnAl films valuable as excellent and cost-effective alternative for not only high density perpendicular magnetic recording storage and spintronics devices but also permanent magnets.

  2. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    SciTech Connect (OSTI)

    M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

    2005-04-01

    Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

  3. Permanent split capacitor single phase electric motor system

    DOE Patents [OSTI]

    Kirschbaum, H.S.

    1984-08-14

    A permanent split capacitor single phase electric motor achieves balanced operation at more than one operating point by adjusting the voltage supplied to the main and auxiliary windings and adjusting the capacitance in the auxiliary winding circuit. An intermediate voltage tap on an autotransformer supplies voltage to the main winding for low speed operation while a capacitive voltage divider is used to adjust the voltage supplied to the auxiliary winding for low speed operation. 4 figs.

  4. Permanent split capacitor single phase electric motor system

    DOE Patents [OSTI]

    Kirschbaum, Herbert S.

    1984-01-01

    A permanent split capacitor single phase electric motor achieves balanced operation at more than one operating point by adjusting the voltage supplied to the main and auxiliary windings and adjusting the capacitance in the auxiliary winding circuit. An intermediate voltage tap on an autotransformer supplies voltage to the main winding for low speed operation while a capacitive voltage divider is used to adjust the voltage supplied to the auxiliary winding for low speed operation.

  5. 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.

  6. Negative ion beam injection apparatus with magnetic shield and electron removal means

    DOE Patents [OSTI]

    Anderson, Oscar A.; Chan, Chun F.; Leung, Ka-Ngo

    1994-01-01

    A negative ion source is constructed to produce H.sup.- ions without using Cesium. A high percentage of secondary electrons that typically accompany the extracted H.sup.- are trapped and eliminated from the beam by permanent magnets in the initial stage of acceleration. Penetration of the magnetic field from the permanent magnets into the ion source is minimized. This reduces the destructive effect the magnetic field could have on negative ion production and extraction from the source. A beam expansion section in the extractor results in a strongly converged final beam.

  7. Mo{sub 2}NiB{sub 2}-type (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} and La{sub 2}Ni{sub 3}-type (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} compounds: Crystal structure and magnetic properties

    SciTech Connect (OSTI)

    Morozkin, A.V.; Isnard, O.; Nirmala, R.; Malik, S.K.

    2015-05-15

    The crystal structure of new Mo{sub 2}NiB{sub 2}-type (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} (Immm, No. 71, oI10) and La{sub 2}Ni{sub 3}-type (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} (Cmce No. 64, oC20) compounds has been established using powder X-ray diffraction studies. Magnetization measurements show that the Mo{sub 2}NiB{sub 2}-type Gd{sub 2}Ni{sub 2.35}Si{sub 0.65} undergoes a ferromagnetic transition at ~66 K, whereas isostructural Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} shows an antiferromagnetic transition at ~52 K and a field-induced metamagnetic transition at low temperatures. Neutron diffraction study shows that, in zero applied field, Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} exhibits c-axis antiferromagnetic order with propagation vector K=[1/2, 0, 1/2] below its magnetic ordering temperature and Tb magnetic moment reaches a value of 8.32(5) μ{sub B} at 2 K. The La{sub 2}Ni{sub 3}-type Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} exhibits ferromagnetic like transition at ~42 K with coexisting antiferromagnetic interactions and field induced metamagnetic transition below ~17 K. The magnetocaloric effect of Gd{sub 2}Ni{sub 2.35}Si{sub 0.65}, Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.5}Si{sub 0.5} is calculated in terms of isothermal magnetic entropy change and it reaches a maximum value of −14.3 J/kg K, −5.3 J/kg K and −10.3 J/kg K for a field change of 50 kOe near 66 K, 52 K and 42 K, respectively. Low temperature magnetic ordering with enhanced anisotropic effects in Tb{sub 2}Ni{sub 2.35}Si{sub 0.65} and Dy{sub 2}Ni{sub 2.35}Si{sub 0.65} is accompanied by a positive magnetocaloric effect with isothermal magnetic entropy changes of +12.8 J/kg K and ~+9.9 J/kg K, respectively at 7 K for a field change of 50 kOe. - Graphical abstract: The (Gd, Tb, Dy){sub 2}Ni{sub 2.35}Si{sub 0.65} supplement the series of Mo{sub 2}NiB{sub 2}-type rare earth compounds, whereas the (Dy, Ho){sub 2}Ni{sub 2.5}Si{sub 0.5} supplement the series of La{sub 2}Ni{sub 3}-type rare

  8. Dose calculation for permanent prostate implants incorporating spatially anisotropic linearly time-resolving edema

    SciTech Connect (OSTI)

    Monajemi, T. T.; Clements, Charles M.; Sloboda, Ron S.

    2011-04-15

    Purpose: The objectives of this study were (i) to develop a dose calculation method for permanent prostate implants that incorporates a clinically motivated model for edema and (ii) to illustrate the use of the method by calculating the preimplant dosimetry error for a reference configuration of {sup 125}I, {sup 103}Pd, and {sup 137}Cs seeds subject to edema-induced motions corresponding to a variety of model parameters. Methods: A model for spatially anisotropic edema that resolves linearly with time was developed based on serial magnetic resonance imaging measurements made previously at our center to characterize the edema for a group of n=40 prostate implant patients [R. S. Sloboda et al., ''Time course of prostatic edema post permanent seed implant determined by magnetic resonance imaging,'' Brachytherapy 9, 354-361 (2010)]. Model parameters consisted of edema magnitude, {Delta}, and period, T. The TG-43 dose calculation formalism for a point source was extended to incorporate the edema model, thus enabling calculation via numerical integration of the cumulative dose around an individual seed in the presence of edema. Using an even power piecewise-continuous polynomial representation for the radial dose function, the cumulative dose was also expressed in closed analytical form. Application of the method was illustrated by calculating the preimplant dosimetry error, RE{sub preplan}, in a 5x5x5 cm{sup 3} volume for {sup 125}I (Oncura 6711), {sup 103}Pd (Theragenics 200), and {sup 131}Cs (IsoRay CS-1) seeds arranged in the Radiological Physics Center test case 2 configuration for a range of edema relative magnitudes ({Delta}=[0.1,0.2,0.4,0.6,1.0]) and periods (T=[28,56,84] d). Results were compared to preimplant dosimetry errors calculated using a variation of the isotropic edema model developed by Chen et al. [''Dosimetric effects of edema in permanent prostate seed implants: A rigorous solution,'' Int. J. Radiat. Oncol., Biol., Phys. 47, 1405-1419 (2000

  9. 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

  10. Permanent-Magnet Adjustable-Speed Motors John S . Hsu (Htsui...

    Office of Scientific and Technical Information (OSTI)

    ... February, 1990, pp. 34 - 40. 20 Anthony Lopez, "Brushless DC Motor," Study Report, Oak ... Westinghouse Electric Corporation, and later for the University of Texas at Austin. Dr. ...

  11. Permanent Magnet Machine And Method With Reluctance Poles For High Strength Undiffused Brushless Operation.

    DOE Patents [OSTI]

    Hsu, John S [Oak Ridge, TN

    2005-12-06

    A method and apparatus in which a rotor (11) and a stator (17) define a radial air gap (20) for receiving AC flux and at least one, and preferably two, DC excitation assemblies (23, 24) are positioned at opposite ends of the rotor (20) to define secondary air gaps (21, 22). Portions of PM material (14a, 14b) are provided as boundaries separating the rotor pole portions (12a, 12b) of opposite polarity from other portions of the rotor (11) and from each other to define PM poles (12a, 12b) for conveying the DC flux to or from the primary air gap (20) and for inhibiting flux from leaking from the pole portions prior to reaching the primary air gap (20). The portions of PM material (14a, 14b) are spaced from each other so as to include reluctance poles (15) of ferromagnetic material between the PM poles (12a, 12b) to interact with the AC flux in the primary-air gap (20).

  12. Airfoil and blade optimization for a direct-drive, permanent magnet wind generator

    SciTech Connect (OSTI)

    Dini, P.; Bayly, E.

    1996-12-31

    A new blade is designed for a small, variable-speed wind turbine by relying on available theoretical design and analysis methods. The performance predictions are compared to field test measurements and are found to be optimistic. This feedback sheds light on the interpretation of the theoretical results and is used to refine the design method. 9 refs., 10 figs.

  13. Novel Manufacturing Technologies for High Power Induction and Permanent Magnet Electric Motors (Agreement ID:23726)

    Broader source: Energy.gov [DOE]

    2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  14. Novel Manufacturing Technologies for High Power Induction and Permanent Magnet Electric Motors

    Broader source: Energy.gov [DOE]

    2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  15. Cogging Torque Reduction in a Permanent Magnet Wind Turbine Generator: Preprint

    SciTech Connect (OSTI)

    Muljadi, E.; Green, J.

    2002-01-01

    In this paper, we investigate three design options to minimize cogging torque: uniformity of air gap, pole width, and skewing. Although the design improvement is intended for small wind turbines, it is also applicable to larger wind turbines.

  16. Low pressure arc discharge lamp apparatus with magnetic field generating means

    DOE Patents [OSTI]

    Grossman, Mark W.; George, William A.; Maya, Jakob

    1987-01-01

    A low-pressure arc discharge apparatus having a magnetic field generating means for increasing the output of a discharge lamp is disclosed. The magnetic field generating means, which in one embodiment includes a plurality of permanent magnets, is disposed along the lamp for applying a constant transverse magnetic field over at least a portion of the positive discharge column produced in the arc discharge lamp operating at an ambient temperature greater than about 25.degree. C.

  17. Low pressure arc discharge lamp apparatus with magnetic field generating means

    DOE Patents [OSTI]

    Grossman, M.W.; George, W.A.; Maya, J.

    1987-10-06

    A low-pressure arc discharge apparatus having a magnetic field generating means for increasing the output of a discharge lamp is disclosed. The magnetic field generating means, which in one embodiment includes a plurality of permanent magnets, is disposed along the lamp for applying a constant transverse magnetic field over at least a portion of the positive discharge column produced in the arc discharge lamp operating at an ambient temperature greater than about 25 C. 3 figs.

  18. 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.

  19. 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.

  20. 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.

  1. Flywheel energy storage with superconductor magnetic bearings

    DOE Patents [OSTI]

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

    1993-01-01

    A flywheel having superconductor bearings has a lower drag to lift ratio that translates to an improvement of a factor of ten in the rotational decay rate. The lower drag results from the lower dissipation of melt-processed YBCO, improved uniformity of the permanent magnet portion of the bearings, operation in a different range of vacuum pressure from that taught by the art, and greater separation distance from the rotating members of conductive materials.

  2. Carbon Dioxide-Water Emulsions for Enhanced Oil Recovery and Permanent Sequestration of Carbon Dioxide

    SciTech Connect (OSTI)

    Ryan, David; Golomb, Dan; Shi, Guang; Shih, Cherry; Lewczuk, Rob; Miksch, Joshua; Manmode, Rahul; Mulagapati, Srihariraju; Malepati, Chetankurmar

    2011-09-30

    This project involves the use of an innovative new invention Particle Stabilized Emulsions (PSEs) of Carbon Dioxide-in-Water and Water-in-Carbon Dioxide for Enhanced Oil Recovery (EOR) and Permanent Sequestration of Carbon Dioxide. The EOR emulsion would be injected into a semi-depleted oil reservoir such as Dover 33 in Otsego County, Michigan. It is expected that the emulsion would dislocate the stranded heavy crude oil from the rock granule surfaces, reduce its viscosity, and increase its mobility. The advancing emulsion front should provide viscosity control which drives the reduced-viscosity oil toward the production wells. The make-up of the emulsion would be subsequently changed so it interacts with the surrounding rock minerals in order to enhance mineralization, thereby providing permanent sequestration of the injected CO{sub 2}. In Phase 1 of the project, the following tasks were accomplished: 1. Perform laboratory scale (mL/min) refinements on existing procedures for producing liquid carbon dioxide-in-water (C/W) and water-in-liquid carbon dioxide (W/C) emulsion stabilized by hydrophilic and hydrophobic fine particles, respectively, using a Kenics-type static mixer. 2. Design and cost evaluate scaled up (gal/min) C/W and W/C emulsification systems to be deployed in Phase 2 at the Otsego County semi-depleted oil field. 3. Design the modifications necessary to the present CO{sub 2} flooding system at Otsego County for emulsion injection. 4. Design monitoring and verification systems to be deployed in Phase 2 for measuring potential leakage of CO{sub 2} after emulsion injection. 5. Design production protocol to assess enhanced oil recovery with emulsion injection compared to present recovery with neat CO{sub 2} flooding. 6. Obtain Federal and State permits for emulsion injection. Initial research focused on creating particle stabilized emulsions with the smallest possible globule size so that the emulsion can penetrate even low-permeability crude

  3. Operation of Lanzhou all permanent electron cyclotron resonance ion source No. 2 on 320 kV platform with highly charged ions

    SciTech Connect (OSTI)

    Lu, W.; Li, J. Y.; Kang, L.; Liu, H. P.; Li, H.; Li, J. D.; Sun, L. T.; Ma, X. W.

    2014-02-15

    The 320 kV platform for multi-discipline research with highly charged ions is a heavy ion beam acceleration instrument developed by Institute of Modern Physics, which is dedicated to basic scientific researches such as plasma, atom, material physics, and astrophysics, etc. The platform has delivered ion beams of 400 species for 36?000 h. The average operation time is around 5000 h/year. With the beams provided by the platform, lots of outstanding progresses were made in various research fields. The ion source of the platform is an all-permanent magnet electron cyclotron resonance ion source, LAPECR2 (Lanzhou All Permanent ECR ion source No. 2). The maximum axial magnetic fields are 1.28 T at injection and 1.07 T at extraction, and the radial magnetic field is up to 1.21 T at the inner wall of the plasma chamber. The ion source is capable to produce low, medium, and high charge state gaseous and metallic ion beams, such as H{sup +}, {sup 40}Ar{sup 8+}, {sup 129}Xe{sup 30+}, {sup 209}Bi{sup 33+}, etc. This paper will present the latest result of LAPECR2 and the routine operation status for the high voltage platform.

  4. Giant Controllable Magnetization Changes Induced by Structural...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Giant Controllable Magnetization ... Type: Accepted Manuscript Journal Name: Scientific Reports Additional Journal Information: Journal ...

  5. 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.

  6. 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.

  7. Fluorescent lamp unit with magnetic field generating means

    DOE Patents [OSTI]

    Grossman, Mark W.; George, William A.

    1989-01-01

    A fluorescent lamp unit having a magnetic field generating means for improving the performance of the fluorescent lamp is disclosed. In a preferred embodiment the fluorescent lamp comprises four longitudinally extending leg portions disposed in substantially quadrangular columnar array and joined by three generally U-shaped portions disposed in different planes. In another embodiment of the invention the magnetic field generating means comprises a plurality of permanent magnets secured together to form a single columnar structure disposed within a centrally located region defined by the shape of lamp envelope.

  8. Fluorescent lamp unit with magnetic field generating means

    DOE Patents [OSTI]

    Grossman, M.W.; George, W.A.

    1989-08-08

    A fluorescent lamp unit having a magnetic field generating means for improving the performance of the fluorescent lamp is disclosed. In a preferred embodiment the fluorescent lamp comprises four longitudinally extending leg portions disposed in substantially quadrangular columnar array and joined by three generally U-shaped portions disposed in different planes. In another embodiment of the invention the magnetic field generating means comprises a plurality of permanent magnets secured together to form a single columnar structure disposed within a centrally located region defined by the shape of lamp envelope. 4 figs.

  9. Conceptual design of a quadrupole magnet for eRHIC

    SciTech Connect (OSTI)

    Witte, H.; Berg, J. S.

    2015-05-03

    eRHIC is a proposed upgrade to the existing Relativistic Heavy Ion Collider (RHIC) hadron facility at Brookhaven National Laboratory, which would allow collisions of up to 21 GeV polarized electrons with a variety of species from the existing RHIC accelerator. eRHIC employs an Energy Recovery Linac (ERL) and an FFAG lattice for the arcs. The arcs require open-midplane quadrupole magnets of up to 30 T/m gradient of good field quality. In this paper we explore initial quadrupole magnet design concepts based on permanent magnetic material which allow to modify the gradient during operation.

  10. Rare-earth-free magnet made from cheap materials

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

    Rare-earth-free magnet Rare-earth-free magnet made from cheap materials Researchers create a powerful permanent magnet out of iron and nitrogen as part of a program to cut the need for rare-earth metals May 17, 2016 Mars (a) 2 × 1016/cm2 fluence, embedded dots can be observed (rich N region), with a diameter of 20 nm, separated by 140 to 200 nm; (b) 8 × 1016/cm2 fluence, besides embedded dots, obvious cracks appeared; (c) 1 × 1017/cm2 fluence, an obvious microstructure is generated, with

  11. CoxC nanorod magnets: Highly magnetocrystalline anisotropy with lower Curie temperature for potential applications

    SciTech Connect (OSTI)

    El-Gendy, AA; Almugaiteeb, T; Carpenter, EE

    2013-12-01

    Magnetic CoxC nanorods with larger magnetocrystalline anisotropy of 5 x 10(5) J/m(3) as well as larger coercivity and lower Curie temperature are introduced. The particles have an average diameter of 8 nm and shows three different magnetic behaviors. The sample shows ferromagnetism up to 400 K, superparamagnetism at temperature > 400 K and permanent magnets, magnetic sensors and contract agent for magnetic resonance imaging. (c) 2013 Elsevier B.V. All rights reserved.

  12. 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 ...

  13. 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.

  14. DOE Announces $68.4 Million in Funding to Advance the Safe and Permanent

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

    Storage of CO2 | Department of Energy Announces $68.4 Million in Funding to Advance the Safe and Permanent Storage of CO2 DOE Announces $68.4 Million in Funding to Advance the Safe and Permanent Storage of CO2 June 24, 2016 - 8:00am Addthis The Department of Energy (DOE) announced $68.4 million for cost-shared research and development (R&D) projects that will help to secure the safe and permanent storage of carbon dioxide (CO2) during carbon capture and storage (CCS) operations. Funding

  15. 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.

  16. 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.

  17. 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.

  18. Raman spectra of Cu{sub 2}B{sup II}C{sup IV}X{sub 4}{sup VI} magnetic quaternary semiconductor compounds with tetragonal stannite type structure

    SciTech Connect (OSTI)

    Rincón, C. Quintero, M.; Power, Ch.; Moreno, E.; Quintero, E.; Morocoima, M.; Henao, J. A.; Macías, M. A.

    2015-05-28

    A comparative study of the Raman spectra of Cu{sub 2}B{sup II}C{sup IV}S{sub 4}{sup VI} and Cu{sub 2}B{sup II}C{sup IV}Se{sub 4}{sup VI}(where B = Mn or Fe) magnetic quaternary semiconductor compounds with stannite-type structure (I4{sup ¯}2m) has been done. Most of the fourteen Raman lines expected for these materials were observed in the spectra. The two strongest lines observed have been assigned to the IR inactive A{sub 1}{sup 1} and A{sub 1}{sup 2} stannite modes that originated from the motion of the S or Se anion around the Cu and C{sup IV} cations remaining at rest. The shift in the frequency of these two lines of about 150 cm{sup −1} to lower energies observed in Cu{sub 2}B{sup II}C{sup IV}Se{sub 4}{sup VI} compounds as compared to those in Cu{sub 2}B{sup II}C{sup IV}S{sub 4}{sup VI} ones, can then be explained as due to the anion mass effect. Based on the fact that values of these frequencies depend mainly on anion mass and bond-stretching forces between nearest-neighbor atoms, the vibrational frequencies v{sup ¯}(A{sub 1}{sup 2}) and v{sup ¯}(A{sub 1}{sup 2}) of both modes for several Cu{sub 2}B{sup II}C{sup IV}X{sub 4}{sup VI} stannite compounds (where X = S, Se, or Te) very close to the experimental data reported for these materials were calculated from a simple model that relates these stretching forces to the anion-cation bond-distances.

  19. 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.

  20. 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.

  1. 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.

  2. EERE Success Story-DOE-Funded Project is First Permanent Facility...

    Energy Savers [EERE]

    Resources at an Oil and Gas Well EERE Success Story-DOE-Funded Project is First Permanent Facility to Co-produce Electricity from Geothermal Resources at an Oil and Gas Well May ...

  3. DOE-Sponsored Field Test Finds Potential for Permanent Storage of CO2 in Lignite Seams

    Broader source: Energy.gov [DOE]

    A field test sponsored by the U.S. Department of Energy has demonstrated that opportunities to permanently store carbon in unmineable seams of lignite may be more widespread than previously documented.

  4. Cleveland EnergySaver Pilot Program (From Pilot to Permanent Program) |

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

    Department of Energy Cleveland EnergySaver Pilot Program (From Pilot to Permanent Program) Cleveland EnergySaver Pilot Program (From Pilot to Permanent Program) Provides an overview of the Cleveland Energy$aver Pilot Program aimed at reducing barriers to widespread adoption of residential energy efficient retrofits. From the Residential Energy Efficiency Solutions Conference 2012. Cleveland Energy$aver Pilot Program (1.41 MB) More Documents & Publications CX-005205: Categorical Exclusion

  5. Propulsion and stabilization system for magnetically levitated vehicles

    DOE Patents [OSTI]

    Coffey, Howard T.

    1993-06-29

    A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and stabilized by a system which includes propulsion windings mounted above and parallel to vehicle-borne suspension magnets. A linear synchronous motor is part of the vehicle guideway and is mounted above and parallel to superconducting magnets attached to the magnetically levitated vehicle.

  6. Mineral Magnetism

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

    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 ...

  7. 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)

  8. Dynamically stable magnetic suspension/bearing system

    DOE Patents [OSTI]

    Post, Richard F.

    1996-01-01

    A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium. However, owing to the limitations imposed by Earnshaw's Theorem, the magnetic bearing systems to be described do not possess a stable equilibrium at zero rotational speed. Therefore, mechanical stabilizers are provided, in each case, to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. The magnetic forces exerted by these elements, when taken together, levitate the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations. At the same time, this equilibrium is made stable against displacements of the rotating object from its equilibrium position by using combinations of elements that possess force derivatives of such magnitudes and signs that they can satisfy the conditions required for a rotating body to be stably supported by a magnetic bearing system over a finite range of those displacements.

  9. Dynamically stable magnetic suspension/bearing system

    DOE Patents [OSTI]

    Post, R.F.

    1996-02-27

    A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium. However, owing to the limitations imposed by Earnshaw`s Theorem, the magnetic bearing systems to be described do not possess a stable equilibrium at zero rotational speed. Therefore, mechanical stabilizers are provided, in each case, to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. The magnetic forces exerted by these elements, when taken together, levitate the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations. At the same time, this equilibrium is made stable against displacements of the rotating object from its equilibrium position by using combinations of elements that possess force derivatives of such magnitudes and signs that they can satisfy the conditions required for a rotating body to be stably supported by a magnetic bearing system over a finite range of those displacements. 32 figs.

  10. Structural, electrochemical and magnetic characterization of the layered-type PrBa{sub 0.5}Sr{sub 0.5}Co{sub 2}O{sub 5+?} perovskite

    SciTech Connect (OSTI)

    Azad, Abul K.; Kim, Jung H.; Irvine, John T.S.

    2014-05-01

    Structural, electrical and magnetic properties of the layered cobaltite PrBa{sub 0.5}Sr{sub 0.5}Co{sub 2}O{sub 5+?} have been investigated by means of neutron diffraction, electron diffraction, thermogravimetric analysis and SQUID magnetometry. Rietveld analysis of neutron diffraction data shows the ordered distribution of oxygen vacancies in [PrO{sub ?}] planes which doubles the lattice parameters from the simple perovskite cell parameter as a?2a{sub p} and c?2a{sub p} (a{sub p} is the cell parameter of the simple Perovskite) yielding tetragonal symmetry in the P4/mmm space group. On heating, above 573 K in air, structural rearrangement takes place and the structure can be defined as a?a{sub p} and c?2a{sub p} in the same space group. Oxygen occupancies have been determined as a function of temperature from neutron diffraction results. Initially (?373 K), oxygen occupancy was increased and then decreased with increasing temperature. It was found that at 973 K the total oxygen loss is calculated about 0.265 oxygen/formula unit. Oxygen vacancy ordering was observed below 573 K, and the oxygen occupancy decreases as cell volume increases with increasing temperature. Area specific resistance (ASR) measurements show a resistance of 0.153 ?cm{sup 2} and 0.286 ?cm{sup 2} at 973 K and 923 K, respectively. On cooling, paramagnetic to ferromagnetic and an incomplete ferromagnetic to antiferromagnetic transition takes place. Different behaviours in field cooled and zero-field-cooled measurements leads to a coexistence of ferromagnetic and antiferromagnetic order. - Graphical abstract: Structural phase changes in PrBa{sub 0.5}Sr{sub 0.5}Co{sub 2}O{sub 5+?} at elevated temperatures determined by neutron powder diffraction. Depending on oxygen occupancy it form different phases at different temperatures. This pictures show the schematic 3D diagram of PrBa{sub 0.5}Sr{sub 0.5}Co{sub 2}O{sub 5+?} at 295 K (a), 373 K (b) and 573 K (c). Co atoms are inside the octahedra/pyramid. Ba

  11. Mass spectrometric helium analysis of solid and gas samples from cold-fusion type experiments

    SciTech Connect (OSTI)

    Oliver, B.M.

    1995-12-01

    A custom mass spectrometer system, operating in static mode, has been used to measure helium in both solid and gas samples front cold-fusion type experiments. The mass spectrometer is a 2-in. Radius, 60{degrees}, permanent angle magnet instrument with a single electron-multiplier collecting. Depending on the absolute levels of helium expected, the analysis are conducted by isotope dilution or by measuring absolute collector values. Solid samples are vaporized to ensure complete helium release. Prior to analysis, the fraction of sample gas to be analyzed is exposed to a series of physical and chemical getters, including room temperature Zr-Al alloy (SAES type 101) and liquid-nitrogen cooled activated charcoal. This is done to remove active gases and hydrogen isotopes which could interfere with the helium determinations. Generally, the analysis protocol is to analyze an equal or greater number of {open_quotes}controls{close_quotes} along with the samples to accurately characterize system background and reproducibility. Absolute sensitivity for the system is approximately 1 x 10{sup 9} atoms. Absolute accuracy is 1% or better for helium levels > 10{sup 11} atoms. With few exceptions, helium analysis of solid samples front cold fusion type experiments have yielded no excess helium above usual system background. A few samples have shown helium levels in the low 10{sup 9} atom range, and some gas samples have shown {sup 4}He levels up to several hundred ppm.

  12. Frequent biphasic cellular responses of permanent fish cell cultures to deoxynivalenol (DON)

    SciTech Connect (OSTI)

    Pietsch, Constanze; Bucheli, Thomas D.; Wettstein, Felix E.; Burkhardt-Holm, Patricia

    2011-10-01

    Contamination of animal feed with mycotoxins is a major problem for fish feed mainly due to usage of contaminated ingredients for production and inappropriate storage of feed. The use of cereals for fish food production further increases the risk of a potential contamination. Potential contaminants include the mycotoxin deoxynivalenol (DON) which is synthesized by globally distributed fungi of the genus Fusarium. The toxicity of DON is well recognized in mammals. In this study, we confirm cytotoxic effects of DON in established permanent fish cell lines. We demonstrate that DON is capable of influencing the metabolic activity and cell viability in fish cells as determined by different assays to indicate possible cellular targets of this toxin. Evaluation of cell viability by measurement of membrane integrity, mitochondrial activity and lysosomal function after 24 h of exposure of fish cell lines to DON at a concentration range of 0-3000 ng ml{sup -1} shows a biphasic effect on cells although differences in sensitivity occur. The cell lines derived from rainbow trout are particularly sensitive to DON. The focus of this study lies, furthermore, on the effects of DON at different concentrations on production of reactive oxygen species (ROS) in the different fish cell lines. The results show that DON mainly reduces ROS production in all cell lines that were used. Thus, our comparative investigations reveal that the fish cell lines show distinct species-related endpoint sensitivities that also depend on the type of tissue from which the cells were derived and the severity of exposure. - Highlights: > DON uptake by cells is not extensive. > All fish cell lines are sensitive to DON. > DON is most cytotoxic to rainbow trout cells. > Biphasic cellular responses were frequently observed. > Our results are similar to studies on mammalian cell lines.

  13. Synthesis and characterization of rare-earth-free magnetic manganese bismuth nanocrystals

    SciTech Connect (OSTI)

    Shen, J; Cui, HZ; Huang, XP; Gong, MG; Qin, W; Kirkeminde, A; Cui, J; Ren, SQ

    2015-01-01

    Earth abundant manganese bismuth (MnBi) has long been of interest due to its largemagnetocrystalline anisotropy and high energy density for advanced permanent magnet applications. However, solution synthesis of MnBi phase is challenging due to the reduction potential mismatch between Mn and Bi elements. In this study, we show a versatile MnBi synthesis method involving the metal co-reduction followed by thermal annealing. The magnetically hard MnBi crystalline phase is then exchange coupled with magnetically soft cobalt coating. Our processing approach offers a promising strategy for manufacturing rare-earth-free magnetic nanocrystals.

  14. Synthesis and Characterization of Rare-earth-free Magnetic Manganese Bismuth Nanocrystals

    SciTech Connect (OSTI)

    Shen, Jian Q.; Cui, Huizhong; Huang, Xiaopeng; Gong, Maogang; Qin, Wei; Kirkeminde, Alec; Cui, Jun; Ren, Shenqiang

    2015-01-01

    Earth abundant manganese bismuth (MnBi) has long been of interest due to its large magnetocrystalline anisotropy and high energy density for advanced permanent magnet applications. However, solution synthesis of MnBi phase is challenging due to the reduction potential mismatch between Mn and Bi elements. In this study, we show a versatile MnBi synthesis method involving the metal co-reduction followed by thermal annealing. The magnetically hard MnBi crystalline phase is then exchange coupled with magnetically soft cobalt coating. Our processing approach offers a promising strategy for manufacturing rare-earth-free magnetic nanocrystals.

  15. Temperature measurement of axisymmetric flames under the influence of magnetic field using Talbot interferometry

    SciTech Connect (OSTI)

    Agarwal, Shilpi E-mail: manojklakra@gmail.com Kumar, Manoj E-mail: manojklakra@gmail.com Shakher, Chandra E-mail: manojklakra@gmail.com

    2014-10-15

    Combustion process control is related with ecological improvement and the problem of energy efficiency; hence it has a wide interest at both economical and scientific levels. Application of a magnetic field is one of the most promising methods of combustion control. The presence of magnetic field induces the changes in flame behavior. The effect of uniform magnetic field developed by permanent magnet is studied by Talbot interferometry using circular gratings. Experimental results show a small decrease in flame temperature and increase in flame dimensions.

  16. Investigation of Heat Transfer at the Mold/Metal Interface in Permanent Mold Casting of Light Alloys

    SciTech Connect (OSTI)

    Robert D. Pehlke; John T. Berry

    2005-12-16

    Accurate modeling of the metal casting process prior to creating a mold design demands reliable knowledge of the interfacial heat transfer coefficient at the mold metal interface as a function of both time and location. The phenomena concerned with the gap forming between the mold and the solidifying metal are complex but need to be understood before any modeling is attempted. The presence of mold coatings further complicates the situation. A commercial casting was chosen and studied in a gravity permanent mold casting process. The metal/mold interfacial heat transfer coefficient (IHTC) was the focus of the research. A simple, direct method has been used to evaluate the IHTC. Both the simulation and experiments have shown that a reasonably good estimate of the heat transfer coefficient could be made in the case studied. It has been found that there is a good agreement between experiments and simulations in the temperature profiles during the solidification process, given that the primary mechanism of heat transfer across the gap in permanent mold casting of light alloys is by conduction across the gap. The procedure utilized to determine the interfacial heat transfer coefficient can be applied to other casting processes. A recently completed project involving The University of Michigan and Mississippi State University, together with several industrial partners, which was supported by the USDOE through the Cast Metals Coalition, examined a number of cases of thermal contact. In an investigation which gave special consideration to the techniques of measurement, several mold coatings were employed and results presented as a function of time. Realistic conditions of coating thickness and type together with an appropriate combination of mold preheat and metal pouring temperature were strictly maintained throughout the investigation. Temperature sensors, in particular thermocouples, play an important part in validating the predictions of solidification models. Cooling

  17. High-efficiency cross-beam magnetic electron-impact source for improved miniature Mattauch-Herzog mass spectrometer performance

    SciTech Connect (OSTI)

    Hadjar, O.; Fowler, W. K.

    2012-06-15

    We describe a newly designed cross-beam magnetic electron-impact ion source (CBM-EI). We demonstrate its superiority in comparison with a conventional source (CB-EI) when used with a commercial miniature sector-field-type, non-scanning mass spectrometer featuring Mattauch-Herzog geometry (MH-MS) and a permanent sector-field magnet. This paper clearly shows the value of the CBM-EI for enhancing MH-MS sensitivity. Unlike secondary electron-multiplier type detectors, the pixelated detector (IonCCD Trade-Mark-Sign ) used in the commercial MH-MS has no gain. The MH-MS/IonCCD system is therefore challenged to compete with time-of-flight and quadrupole MS systems due to their higher ion transmissions and detector gains. Using the new CBM-EI, we demonstrate an instrument sensitivity increase of 20-fold to 100-fold relative to the CB-EI-equipped instrument. This remarkable signal increase by the simple addition of the magnet assembly arises from the magnet-induced gyromotion of the thermionic electrons, which vastly increases the effective path length of the electrons through the ionization region, and the collimated nature of the electron flux, which optimizes the ion transmission through the 100-{mu}m object slit of the MH-MS. Some or all of the realized sensitivity increase may be exchanged for an increase in resolution and/or mass range through the use of a narrower object slit, or for a reduction in ion-source pressure to limit quenching. The CBM-EI should facilitate development of a differentially pumped ion source to extend the lifetime of the filament, especially in otherwise intractable applications associated with oxidizing and corrosive samples.

  18. 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 ...

  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. Electrostatic stabilizer for a passive magnetic bearing system

    DOE Patents [OSTI]

    Post, Richard F.

    2015-11-24

    Electrostatic stabilizers are provided for passive bearing systems composed of annular magnets having a net positive stiffness against radial displacements and that have a negative stiffness for vertical displacements, resulting in a vertical instability. Further embodiments are shown of a radial electrostatic stabilizer geometry (using circuitry similar to that employed in the vertical stabilizer). This version is suitable for stabilizing radial (lateral) displacements of a rotor that is levitated by annular permanent magnets that are stable against vertical displacements but are unstable against radial displacements.

  1. Electrostatic stabilizer for a passive magnetic bearing system

    DOE Patents [OSTI]

    Post, Richard F.

    2015-12-01

    Electrostatic stabilizers are provided for passive bearing systems composed of annular magnets having a net positive stiffness against radial displacements and that have a negative stiffness for vertical displacements, resulting in a vertical instability. Further embodiments are shown of a radial electrostatic stabilizer geometry (using circuitry similar to that employed in the vertical stabilizer). This version is suitable for stabilizing radial (lateral) displacements of a rotor that is levitated by annular permanent magnets that are stable against vertical displacements but are unstable against radial displacements.

  2. Brushless machine having ferromagnetic side plates and side magnets

    DOE Patents [OSTI]

    Hsu, John S

    2012-10-23

    An apparatus is provided having a cylindrical stator and a rotor that is spaced from a stator to define an annular primary air gap that receives AC flux from the stator. The rotor has a plurality of longitudinal pole portions disposed parallel to the axis of rotation and alternating in polarity around a circumference of the rotor. Each longitudinal pole portion includes portions of permanent magnet (PM) material and at least one of the longitudinal pole portions has a first end and an opposing second end and a side magnet is disposed adjacent the first end and a side pole is disposed adjacent the second end.

  3. Eu3Ir2In15: A mixed-valent and vacancy-filled variant of the Sc5Co4Si10 structure type with anomalous magnetic properties

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

    Sarkar, Sumanta; Jana, Rajkumar; Siva, Ramesh; Banerjee, Swastika; Pati, Swapan K.; Balasubramanian, Mahalingam; Peter, Sebastian C.

    2015-10-27

    Here, a new compound, Eu3Ir2In15 has been synthesized using indium as an active metal flux. The compound crystallizes in tetragonal P4/mbm space group with lattice parameters, a = 14.8580(4) Å, b = 14.8580(4) Å, c = 4.3901(2) Å. It was further characterized by SEM-EDX studies. The temperature dependent magnetic susceptibility suggests that Eu in this compound is exclusively in divalent state. The effective magnetic moment (μeff) of this compound is 7.35 μB/Eu ion with paramagnetic Curie temperature (θp) of -28 K suggesting antiferromagnetic interaction. The mixed valent nature of Eu observed in magnetic measurements was confirmed by XANES measurements. Themore » compound undergoes demagnetization at a low magnetic field (10 Oe), which is quite unusual for Eu based intermetallic compounds. Temperature dependent resistivity studies reveal that the compound is metallic in nature. A comparative study was made between Eu3Ir2In15 and hypothetical vacancy variant Eu5Ir4In10 which also crystallizes in the same crystal structure However our computational studies along with control experiments suggest that the latter is thermodynamically less feasible compared to the former and hence we proposed that it is highly unlikely that a RE5T4X10 would exist with X as a group 13 elements.« less

  4. The magnetic flywheel flow meter: Theoretical and experimental contributions

    SciTech Connect (OSTI)

    Buchenau, D. Galindo, V.; Eckert, S.

    2014-06-02

    The development of contactless flow meters is an important issue for monitoring and controlling of processes in different application fields, like metallurgy, liquid metal casting, or cooling systems for nuclear reactors and transmutation machines. Shercliff described in his book “The Theory of Electromagnetic Flow Measurement, Cambridge University Press, 1962” a simple and robust device for contact-less measurements of liquid metal flow rates which is known as magnetic flywheel. The sensor consists of several permanent magnets attached on a rotatable soft iron plate. This arrangement will be placed closely to the liquid metal flow to be measured, so that the field of the permanent magnets penetrates into the fluid volume. The flywheel will be accelerated by a Lorentz force arising from the interaction between the magnetic field and the moving liquid. Steady rotation rates of the flywheel can be taken as a measure for the mean flow rate inside the fluid channel. The present paper provides a detailed theoretical description of the sensor in order to gain a better insight into the functional principle of the magnetic flywheel. Theoretical predictions are confirmed by corresponding laboratory experiments. For that purpose, a laboratory model of such a flow meter was built and tested on a GaInSn-loop under various test conditions.

  5. Precision formed micro magnets: LDRD project summary report

    SciTech Connect (OSTI)

    CHRISTENSON,TODD R.; GARINO,TERRY J.; VENTURINI,EUGENE L.

    2000-02-01

    A microfabrication process is described that provides for the batch realization of miniature rare earth based permanent magnets. Prismatic geometry with features as small as 5 microns, thicknesses up through several hundred microns and with submicron tolerances may be accommodated. The processing is based on a molding technique using deep x-ray lithography as a means to generate high aspect-ratio precision molds from PMMA (poly methyl methacrylate) used as an x-ray photoresist. Subsequent molding of rare-earth permanent magnet (REPM) powder combined with a thermosetting plastic binder may take place directly in the PMMA mold. Further approaches generate an alumina form replicated from the PMMA mold that becomes an intermediate mold for pressing higher density REPM material and allows for higher process temperatures. Maximum energy products of 3--8 MGOe (Mega Gauss Oersted, 1 MGOe = 100/4{pi} kJ/m{sup 3}) are obtained for bonded isotropic forms of REPM with dimensions on the scale of 100 microns and up to 23 MGOe for more dense anisotropic REPM material using higher temperature processing. The utility of miniature precision REPMs is revealed by the demonstration of a miniature multipole brushless DC motor that possesses a pole-anisotropic rotor with dimensions that would otherwise prohibit multipole magnetization using a multipole magnetizing fixture at this scale. Subsequent multipole assembly also leads to miniaturized Halbach arrays, efficient magnetic microactuators, and mechanical spring-like elements which can offset miniaturized mechanical scaling behavior.

  6. Effect of Mn doping on structural and magnetic susceptibility of C-type rare earth nano oxides Er{sub 2?x}Mn{sub x}O{sub 3}

    SciTech Connect (OSTI)

    Heiba, Zein K.; Taif University, Faculty of Science, Physics Department ; Mohamed, Mohamed Bakr; Fuess, H.

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ? Er{sub 2?x}Mn{sub x}O{sub 3} (0.0 ? x ? 0.20) prepared by solgel method. ? The change in lattice parameter is not linear with x due to the change in crystallite size with doping. ? Anomalous concentration dependence is found in magnetic susceptibility. ? The effective magnetic moment ?{sub eff} is found to decrease with composition parameter x. ? Superexchange interactions between Er ions depending on the amount of Mn or Er in different sites. -- Abstract: The manganese doped rare earth oxides Er{sub 2?x}Mn{sub x} O{sub 3} (0.0 ? x ? 0.20) were synthesized by a solgel process and analyzed by X-ray diffraction using Rietveld refinement methods. A single phase solid solution is formed up to x = 0.15 while for x ? 0.2 a manganese oxide phase appears in the diffraction pattern. Preferential cationic distribution between the non-equivalent sites 8b and 24d of space group Ia3{sup } is found for all samples but to a different extent. The octahedral volume and average bond length of Er{sub 1}-O for 8b site decrease while both octahedral volume and bond length of Er{sub 2}-O for 24d site increase. Magnetization measurements were done in the temperature range 5300 K. The effective magnetic moment ?{sub eff} is found to decrease with composition parameter x, except for sample x = 0.05 where the magnetization is enhanced. The Curie-Weiss paramagnetic temperatures indicate antiferromagnetic interaction.

  7. EERE Success Story-DOE-Funded Project is First Permanent Facility to

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

    Co-produce Electricity from Geothermal Resources at an Oil and Gas Well | Department of Energy Project is First Permanent Facility to Co-produce Electricity from Geothermal Resources at an Oil and Gas Well EERE Success Story-DOE-Funded Project is First Permanent Facility to Co-produce Electricity from Geothermal Resources at an Oil and Gas Well May 12, 2016 - 11:03am Addthis Source: Kirby Baier of Continental Resources Source: Kirby Baier of Continental Resources The U.S. Department of

  8. Magnetic separation of micro-spheres from viscous biological fluids.

    SciTech Connect (OSTI)

    Chen, H.; Kaminski, M. D.; Xianqiao, L.; Caviness, P.; Torno, M.; Rosengart, A. J.; Dhar, P.; Chemical Engineering; Univ. of Chicago Pritzker School of Medicine; Illinois Inst. of Tech.

    2007-02-21

    A magnetically based detoxification system is being developed as a therapeutic tool for selective and rapid removal of biohazards, i.e. chemicals and radioactive substances, from human blood. One of the key components of this system is a portable magnetic separator capable of separating polymer-based magnetic nano/micro-spheres from arterial blood flow in an ex vivo unit. The magnetic separator consists of an array of alternating and parallel capillary tubing and magnetizable wires, which is exposed to an applied magnetic field created by two parallel permanent magnets such that the magnetic field is perpendicular to both the wires and the fluid flow. In this paper, the performance of this separator was evaluated via preliminary in vitro flow experiments using a separator unit consisting of single capillary glass tubing and two metal wires. Pure water, ethylene glycol-water solution (v:v = 39:61 and v:v = 49:51) and human whole blood were used as the fluids. The results showed that when the viscosity increased from 1.0 cp to 3.0 cp, the capture efficiency (CE) decreased from 90% to 56%. However, it is still feasible to obtain >90% CE in blood flow if the separator design is optimized to create higher magnetic gradients and magnetic fields in the separation area.

  9. Alkali-vapor magnetic resonance driven by fictitious radiofrequency fields

    SciTech Connect (OSTI)

    Zhivun, Elena; Wickenbrock, Arne; Patton, Brian; Budker, Dmitry

    2014-11-10

    We demonstrate an all-optical {sup 133}Cs scalar magnetometer, operating in nonzero magnetic field, in which the magnetic resonance is driven by an effective oscillating magnetic field provided by the AC Stark shift of an intensity-modulated laser beam. We achieve a projected shot-noise-limited sensitivity of 1.7fT/√(Hz) and measure a technical noise floor of 40fT/√(Hz). These results are essentially identical to a coil-driven scalar magnetometer using the same setup. This all-optical scheme offers advantages over traditional coil-driven magnetometers for use in arrays and in magnetically sensitive fundamental physics experiments, e.g., searches for a permanent electric dipole moment of the neutron.

  10. Exchange-Spring Magnets: Nanocomposite Exchange-Spring Magnets for Motor and Generator Applications

    SciTech Connect (OSTI)

    2012-01-01

    REACT Project: ANL will develop a cost-effective exchange-spring magnet to use in the electric motors of wind generators and EVs that uses no rare earth materials. This ANL exchange-spring magnet combines a hard magnetic outer shell with a soft magnetic inner corecoupling these together increases the performance (energy density and operating temperature). The hard and soft magnet composite particles would be created at the molecular level, followed by consolidation in a magnetic field. This process allows the particles to be oriented to maximize the magnetic properties of low-cost and abundant metals, eliminating the need for expensive imported rare earths. The ultimate goal of this project is to demonstrate this new type of magnet in a prototype electric motor.

  11. Identification of multi-modal plasma responses to applied magnetic...

    Office of Scientific and Technical Information (OSTI)

    Title: Identification of multi-modal plasma responses to applied magnetic ... Type: Publisher's Accepted Manuscript Journal Name: Physics of Plasmas Additional Journal ...

  12. Proximity-induced magnetism in transition-metal substituted graphene...

    Office of Scientific and Technical Information (OSTI)

    Proximity-induced magnetism in transition-metal substituted graphene Citation ... GrantContract Number: AC07-05ID14517 Type: Accepted Manuscript Journal Name: Scientific Reports ...

  13. Magnetism reflectometer study shows LiF layers improve efficiency...

    Office of Scientific and Technical Information (OSTI)

    New, more efficient materials for spin valves - a device ... be on the way based on research using the magnetism ... Resource Type: Journal Article Resource Relation: ...

  14. Award Types

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

    Awards Team (505) 667-7824 Email Types of Awards The Awards Office, sponsored by the Technology Transfer Division and the Science and Technology Base Program Office, coordinates...

  15. Permanent magnet machine and method with reluctance poles and non-identical PM poles for high density operation

    DOE Patents [OSTI]

    Hsu, John S.

    2010-05-18

    A method and apparatus in which a stator (11) and a rotor (12) define a primary air gap (20) for receiving AC flux and at least one source (23, 40), and preferably two sources (23, 24, 40) of DC excitation are positioned for inducing DC flux at opposite ends of the rotor (12). Portions of PM material (17, 17a) are provided as boundaries separating PM rotor pole portions from each other and from reluctance poles. The PM poles (18) and the reluctance poles (19) can be formed with poles of one polarity having enlarged flux paths in relation to flux paths for pole portions of an opposite polarity, the enlarged flux paths communicating with a core of the rotor (12) so as to increase reluctance torque produced by the electric machine. Reluctance torque is increased by providing asymmetrical pole faces. The DC excitation can also use asymmetric poles and asymmetric excitation sources. Several embodiments are disclosed with additional variations.

  16. Vehicle Technologies Office Merit Review 2016: Novel Manufacturing Technologies for High Power Induction and Permanent Magnet Electric Motors

    Broader source: Energy.gov [DOE]

    Presentation given by Pacific Northwest National Laboratory (PNNL) at the 2016 DOE Vehicle Technologies Office and Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Meeting...

  17. Vehicle Technologies Office Merit Review 2014: Novel Manufacturing Technologies for High Power Induction and Permanent Magnet Electric Motors

    Broader source: Energy.gov [DOE]

    Presentation given by Pacific Northwest National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about novel...

  18. Vehicle Technologies Office Merit Review 2015: Brushless and Permanent Magnet Free Wound Field Synchronous Motors for EV Traction

    Broader source: Energy.gov [DOE]

    Presentation given by U of Wisconsin-Madison at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about brushless and...

  19. Vehicle Technologies Office Merit Review 2015: Novel Manufacturing Technologies for High Power Induction and Permanent Magnet Electric Motors

    Broader source: Energy.gov [DOE]

    Presentation given by Pacific Northwest National Laboratory at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about novel...

  20. Magnetic Reconnection

    SciTech Connect (OSTI)

    Masaaki Yamada, Russell Kulsrud and Hantao Ji

    2009-09-17

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

  1. A nanotubular metal-organic framework with permanent porosity : structure analysis and gas sorption studies.

    SciTech Connect (OSTI)

    Ma, S.; Simmons, J. M.; Li, J. R.; Yuan, D.; Weng, W.; Liu, D. J.; Zhou, H. C.; Chemical Sciences and Engineering Division; Texas A&M Univ.; NIST

    2009-01-01

    A nanotubular metal-organic framework, PCN-19, was constructed based on a micro3-oxo-trinickel basic carboxylate secondary building unit (SBU) and the 9,10-anthracenedicarboxylate ligand; its permanent porosity was confirmed by N2 adsorption isotherms, and its H2 storage performances were evaluated under both low and high pressures at 77 K.

  2. Permanent Closure of MFC Biodiesel Underground Storage Tank 99ANL00013

    SciTech Connect (OSTI)

    Kerry L. Nisson

    2012-10-01

    This closure package documents the site assessment and permanent closure of the Materials and Fuels Complex biodiesel underground storage tank 99ANL00013 in accordance with the regulatory requirements established in 40 CFR 280.71, “Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks: Out-of-Service UST Systems and Closure.”

  3. ''Heat Transfer at the Mold-Metal Interface in Permanent Mold Casting of Aluminum Alloys'' Final Project Report

    SciTech Connect (OSTI)

    Professor R. D. Pehlke, Principal Investigator, Dr. John M. Cookson, Dr. Shouwei Hao, Dr. Prasad Krishna, Kevin T. Bilkey

    2001-12-14

    This project on heat transfer coefficients in metal permanent mold casting has been conducted in three areas. They are the theoretical study at the University of Michigan, the experimental investigation of squeeze casting at CMI-Tech Center (Now Hayes-Lemmerz Technical Center) and the experimental investigation of low pressure permanent mold casting at Amcast Automotive.

  4. Driven reconnection in magnetic fusion experiments

    SciTech Connect (OSTI)

    Fitzpatrick, R.

    1995-11-01

    Error fields (i.e. small non-axisymmetric perturbations of the magnetic field due to coil misalignments, etc.) are a fact of life in magnetic fusion experiments. What effects do error fields have on plasma confinement? How can any detrimental effects be alleviated? These, and other, questions are explored in detail in this lecture using simple resistive magnetohydrodynamic (resistance MHD) arguments. Although the lecture concentrates on one particular type of magnetic fusion device, namely, the tokamak, the analysis is fairly general and could also be used to examine the effects of error fields on other types of device (e.g. Reversed Field Pinches, Stellerators, etc.).

  5. Novel pre-alloyed powder processing of modified alnico 8: Correlation of microstructure and magnetic properties

    SciTech Connect (OSTI)

    Anderson, I. E.; Kassen, A. G.; White, E. M. H.; Zhou, L.; Tang, W.; Palasyuk, A.; Dennis, K. W.; McCallum, R. W.; Kramer, M. J.

    2015-04-13

    Progress is reviewed on development of an improved near-final bulk magnet fabrication process for alnico 8, as a non-rare earth permanent magnet with promise for sufficient energy density and coercivity for electric drive motors. This study showed that alnico bulk magnets in near-final shape can be made by simple compression molding from spherical high purity gas atomized pre-alloyed powder. Dwell time at peak sintering temperature (1250°C) greatly affected grain size of the resulting magnet alloys. This microstructure transformation was demonstrated to be useful for gaining partially aligned magnetic properties and boosting energy product. Furthermore, while a route to increased coercivity was not identified by these experiments, manufacturability of bulk alnico magnet alloys in near-final shapes was demonstrated, permitting further processing and alloy modification experiments that can target higher coercivity and better control of grain anisotropy during grain growth.

  6. Novel pre-alloyed powder processing of modified alnico 8: Correlation of microstructure and magnetic properties

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

    Anderson, I. E.; Kassen, A. G.; White, E. M. H.; Zhou, L.; Tang, W.; Palasyuk, A.; Dennis, K. W.; McCallum, R. W.; Kramer, M. J.

    2015-04-13

    Progress is reviewed on development of an improved near-final bulk magnet fabrication process for alnico 8, as a non-rare earth permanent magnet with promise for sufficient energy density and coercivity for electric drive motors. This study showed that alnico bulk magnets in near-final shape can be made by simple compression molding from spherical high purity gas atomized pre-alloyed powder. Dwell time at peak sintering temperature (1250°C) greatly affected grain size of the resulting magnet alloys. This microstructure transformation was demonstrated to be useful for gaining partially aligned magnetic properties and boosting energy product. Furthermore, while a route to increased coercivitymore » was not identified by these experiments, manufacturability of bulk alnico magnet alloys in near-final shapes was demonstrated, permitting further processing and alloy modification experiments that can target higher coercivity and better control of grain anisotropy during grain growth.« less

  7. Hybrid magnet devices for molecule manipulation and small scale high gradient-field applications

    DOE Patents [OSTI]

    Humphries, David E.; Hong, Seok-Cheol; Cozzarelli, legal representative, Linda A.; Pollard, Martin J.; Cozzarelli, Nicholas R.

    2009-01-06

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetizable molecular structures and targets. Also disclosed are hybrid magnetic tweezers able to exert approximately 1 nN of force to 4.5 .mu.m magnetic bead. The maximum force was experimentally measured to be .about.900 pN which is in good agreement with theoretical estimations and other measurements. In addition, a new analysis scheme that permits fast real-time position measurement in typical geometry of magnetic tweezers has been developed and described in detail.

  8. 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.

  9. Model and simulation of a flywheel energy storage system at a utility substation using electro-magnetic transients programs

    SciTech Connect (OSTI)

    Weissbach, R.S.; Karady, G.G.; Farmer, R.G.

    1996-11-01

    A flywheel energy storage system for use as an uninterruptible power supply at a utility substation to replace electrochemical batteries has been modeled. The model is developed using the Electro-Magnetic Transients Program (EMTP). Models for the flywheel, permanent magnet (synchronous) motor/generator, rectifiers and inverter have been included. Transient response for loss of power and clearing of a short circuit fault, as well as variation of load voltage due to the flywheel spinning down, is presented.

  10. The Use of Small Coolers in a Magnetic Field

    SciTech Connect (OSTI)

    Green, Michael A.; Witte, Holger

    2007-07-25

    Small 4 K coolers are used to cool superconducting magnets.These coolers are usually used with high temperature suerconductor (HTS)leads. In most cases, magnet is shielded with iron or active shieldcoils. Thus the field at the cooler is low. There are instances when thecooler must be in a magnetic field. Gifford McMahon (GM) coolers or pulsetube coolers are commercially available to cool the magnets. This paperwill discuss how the two types of coolers are affected by the straymagnetic field. Strategies for using coolers on magnets that generatestray magnetic fields are discussed.

  11. Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Light Metals Permanent Mold Casting

    SciTech Connect (OSTI)

    Fasoyinu, Yemi

    2014-03-31

    Current vehicles use mostly ferrous components for structural applications. It is possible to reduce the weight of the vehicle by substituting these parts with those made from light metals such as aluminum and magnesium. Many alloys and manufacturing processes can be used to produce these light metal components and casting is known to be most economical. One of the high integrity casting processes is permanent mold casting which is the focus of this research report. Many aluminum alloy castings used in automotive applications are produced by the sand casting process. Also, aluminum-silicon (Al-Si) alloys are the most widely used alloy systems for automotive applications. It is possible that by using high strength aluminum alloys based on an aluminum-copper (Al-Cu) system and permanent mold casting, the performance of these components can be enhanced significantly. This will also help to further reduce the weight. However, many technological obstacles need to be overcome before using these alloys in automotive applications in an economical way. There is very limited information in the open literature on gravity and low-pressure permanent mold casting of high strength aluminum alloys. This report summarizes the results and issues encountered during the casting trials of high strength aluminum alloy 206.0 (Al-Cu alloy) and moderate strength alloy 535.0 (Al-Mg alloy). Five engineering components were cast by gravity tilt-pour or low pressure permanent mold casting processes at CanmetMATERIALS (CMAT) and two production foundries. The results of the casting trials show that high integrity engineering components can be produced successfully from both alloys if specific processing parameters are used. It was shown that a combination of melt processing and mold temperature is necessary for the elimination of hot tears in both alloys.

  12. A safety and regulatory assessment of generic BWR and PWR permanently shutdown nuclear power plants

    SciTech Connect (OSTI)

    Travis, R.J.; Davis, R.E.; Grove, E.J.; Azarm, M.A.

    1997-08-01

    The long-term availability of less expensive power and the increasing plant modification and maintenance costs have caused some utilities to re-examine the economics of nuclear power. As a result, several utilities have opted to permanently shutdown their plants. Each licensee of these permanently shutdown (PSD) plants has submitted plant-specific exemption requests for those regulations that they believe are no longer applicable to their facility. This report presents a regulatory assessment for generic BWR and PWR plants that have permanently ceased operation in support of NRC rulemaking activities in this area. After the reactor vessel is defueled, the traditional accident sequences that dominate the operating plant risk are no longer applicable. The remaining source of public risk is associated with the accidents that involve the spent fuel. Previous studies have indicated that complete spent fuel pool drainage is an accident of potential concern. Certain combinations of spent fuel storage configurations and decay times, could cause freshly discharged fuel assemblies to self heat to a temperature where the self sustained oxidation of the zircaloy fuel cladding may cause cladding failure. This study has defined four spent fuel configurations which encompass all of the anticipated spent fuel characteristics and storage modes following permanent shutdown. A representative accident sequence was chosen for each configuration. Consequence analyses were performed using these sequences to estimate onsite and boundary doses, population doses and economic costs. A list of candidate regulations was identified from a screening of 10 CFR Parts 0 to 199. The continued applicability of each regulation was assessed within the context of each spent fuel storage configuration and the results of the consequence analyses.

  13. Try This: Household Magnets

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

    Now which is stronger, gravity or magnetism? What is going on? How do flexible refrigerator magnets work? Get two of these magnets, they are often the size of a business card....

  14. Magnetic resonance imaging of living systems by remote detection

    DOE Patents [OSTI]

    Wemmer, David; Pines, Alexander; Bouchard, Louis; Xu, Shoujun; Harel, Elad; Budker, Dmitry; Lowery, Thomas; Ledbetter, Micah

    2013-10-29

    A novel approach to magnetic resonance imaging is disclosed. Blood flowing through a living system is prepolarized, and then encoded. The polarization can be achieved using permanent or superconducting magnets. The polarization may be carried out upstream of the region to be encoded or at the place of encoding. In the case of an MRI of a brain, polarization of flowing blood can be effected by placing a magnet over a section of the body such as the heart upstream of the head. Alternatively, polarization and encoding can be effected at the same location. Detection occurs at a remote location, using a separate detection device such as an optical atomic magnetometer, or an inductive Faraday coil. The detector may be placed on the surface of the skin next to a blood vessel such as a jugular vein carrying blood away from the encoded region.

  15. Magnetic phase diagram of Tb{sub 3}Co

    SciTech Connect (OSTI)

    Baranov, N.V.; Markin, P.E.; Nakotte, H.; Lacerda, A.

    1997-08-01

    The orthorhombic Tb{sub 3}Co compound exhibits both ferromagnetic and antiferromagnetic behavior below the critical temperature T{sub t} = 72 K as evidenced by metamagnetic transitions along the a- and b-axes and ferromagnetic magnetization process along the c-axis. In the temperature interval between T{sub t} and the Neel temperature T{sub N} = 82 field-induced transitions along all three axes are observed. This behavior results from the complex noncomplanar magnetic structure of Tb{sub 3}Co. The metamagnetic transitions are accompanied by a significant magnetoresistance effect. The Tb{sub 3}Co single crystal has permanent magnet properties along the c-axis with the highest energy up to 140 Mg Oe at T < 4.2 K.

  16. Cryogen free superconducting splittable quadrupole magnet for linear accelerators

    SciTech Connect (OSTI)

    Kashikhin, V.S.; Andreev, N.; Kerby, J.; Orlov, Y.; Solyak, N.; Tartaglia, M.; Velev, G.; /Fermilab

    2011-09-01

    A new superconducting quadrupole magnet for linear accelerators was fabricated at Fermilab. The magnet is designed to work inside a cryomodule in the space between SCRF cavities. SCRF cavities must be installed inside a very clean room adding issues to the magnet design, and fabrication. The designed magnet has a splittable along the vertical plane configuration and could be installed outside of the clean room around the beam pipe previously connected to neighboring cavities. For more convenient assembly and replacement a 'superferric' magnet configuration with four racetrack type coils was chosen. The magnet does not have a helium vessel and is conductively cooled from the cryomodule LHe supply pipe and a helium gas return pipe. The quadrupole generates 36 T integrated magnetic field gradient, has 600 mm effective length, and the peak gradient is 54 T/m. In this paper the quadrupole magnetic, mechanical, and thermal designs are presented, along with the magnet fabrication overview and first test results.

  17. 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.

  18. Type: Renewal

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

    1 INCITE Awards Type: Renewal Title: -Ab Initio Dynamical Simulations for the Prediction of Bulk Properties‖ Principal Investigator: Theresa Windus, Iowa State University Co-Investigators: Brett Bode, Iowa State University Graham Fletcher, Argonne National Laboratory Mark Gordon, Iowa State University Monica Lamm, Iowa State University Michael Schmidt, Iowa State University Scientific Discipline: Chemistry: Physical INCITE Allocation: 10,000,000 processor hours Site: Argonne National

  19. Facility Type!

    Office of Legacy Management (LM)

    ITY: --&L~ ----------- srct-r~ -----------~------~------- if yee, date contacted ------------- cl Facility Type! i I 0 Theoretical Studies Cl Sample 84 Analysis ] Production 1 Diepasal/Storage 'YPE OF CONTRACT .--------------- 1 Prime J Subcontract&- 1 Purchase Order rl i '1 ! Other information (i.e., ---------~---~--~-------- :ontrait/Pirchaee Order # , I C -qXlJ- --~-------~~-------~~~~~~ I I ~~~---~~~~~~~T~~~ FONTRACTING PERIODi IWNERSHIP: ,I 1 AECIMED AECMED GOVT GOUT &NTtiAC+OR

  20. Magnetic Refrigeration Technology for High Efficiency Air Conditioning

    SciTech Connect (OSTI)

    Boeder, A; Zimm, C

    2006-09-30

    Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate

  1. Magnetic multilayer structure

    DOE Patents [OSTI]

    Herget, Philipp; O'Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2016-07-05

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  2. Magnetic Membrane System

    DOE Patents [OSTI]

    McElfresh, Michael W.; ; Lucas, Matthew S.

    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.

  3. Type here

    Office of Environmental Management (EM)

    Injury at the Savannah River National Laboratory | Department of Energy January 10, 2006, Flash Fire and Injury at the Savannah River National Laboratory Type B Accident Investigation of the January 10, 2006, Flash Fire and Injury at the Savannah River National Laboratory February 1, 2006 On January 10, 2006, at approximately 7:47 a.m., a first-line manager (FLM) at the Savannah River National Laboratory (SRNL) received first- and second-degree burns to his head, face, neck, and left hand

  4. Magnetic properties of bulk, and rapidly solidified nanostructured (Nd1-xCex)2Fe14-yCoyB ribbons

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

    Pathak, Arjun K.; Khan, M.; Gschneidner, Jr., K. A.; McCallum, R. W.; Zhou, L.; Sun, K.; Kramer, M. J.; Pecharsky, V. K.

    2015-11-06

    Magnetic properties of Ce and Co co-doped (Nd1-xCex)2Fe14-yCoyB compounds have been investigated both in bulk polycrystalline and rapidly solidified nanostructured ribbon forms. For certain Ce concentrations the materials exhibit spin re-orientation transitions below 140 K. The Curie temperatures, saturation magnetizations, and other magnetic properties relevant for applications as permanent magnets are controlled by Ce and Co substitutions for Nd and Fe, respectively. Most importantly, the results show that Ce, Co co-doped compounds are excellent replacements for several Dy-based high performance permanent magnets (dysprosium is one of the critical elements and is, therefore, in short supply). As a result, the highmore » temperature (>375 K) magnetic properties for Nd–Ce–Fe–Co–B based alloys show promise not only as a replacement for Dy-doped Nd2Fe14B permanent magnets, but the new alloys also require significantly lower amounts of Nd, which too is the critical element that can be replaced by a more abundant Ce.« less

  5. Applied magnetism: A supply-driven materials challenge

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

    Rios, Orlando; McCall, Scott K.

    2016-05-27

    Permanent magnets are important in many green energy technologies including wind turbine generators and hybrid-electric vehicle motors. For these applications, volume and weight are important factors driving the overall design, and therefore a high energy density, or energy product, is an important figure of merit. This quantity defines the magnetic energy contained in a given volume of material, and so higher energy density magnets enable smaller, lighter applications. Currently, the most powerful magnets suitable for commercial purposes contain rare earth elements (REE), usually neodymium and dysprosium in the neodymium-iron-boride class of magnets. However, for select applications, often requiring high temperatures,more » samarium cobalt is the alloy of choice. These magnets have energy densities several times greater than their nearest non-REE-based competitor, which for some applications is the defining factor in creating a viable device. The global supply of these REE is overwhelmingly produced in China, which in 2015 mined more than ten times as much as the next largest producer (Australia). Such market domination effectively creates a single source of supply, leaving industries which rely on REE consumption susceptible to price shocks and supply disruptions of these critical materials. Furthermore, this supply sensitivity may act as a drag on the adaptation rate of green energy technologies, particularly for large-scale users.« less

  6. A New Approach for the Permanent Disposal of Long Lived Fission Waste

    SciTech Connect (OSTI)

    Perkins, L J

    2007-03-27

    Nuclear fission can meet humanity's disparate requirements for carbon-free energy throughout this century and for millennia to come - not only for electricity but also as a source of hydrogen for transportation fuels and a heat source for desalination. However, most countries are not pursuing fission as an option for future energy and global climate needs. One paramount reason is diminished public acceptance over concerns of waste disposal. We would also add 'fuel resources' as a major future concern, because fission is not sustainable in the long term with the present 'once-through' fuel that utilizes less than 1% of the mined uranium and consigns its fertile potential to a permanent waste repository. Accordingly, global scale fission will become attainable (i.e., doable) if and when an integrated solution to this overall 'fuel-cycle' problem is realized. It is the back-end of the fuel cycle - i.e., the need for permanent storage of spent fuel and high-level waste - that has become the focus of much of the criticism. In particular, the construction and implementation of permanent waste repositories such as Yucca Mountain is becoming increasingly problematic from a financial and political perspective. The major shortcoming of these conventional repositories is that they must accommodate the whole spent fuel output from once-through fuel cycles. They are thus burdened with very large masses of material but where less than 1% is long-term, hazardous waste and where only a small fraction of the potential nuclear energy has been extracted. Second, such facilities must ensure integrity of waste containment for tens of thousands of years. Given that anything more than a few hundred years hence is unknowable and wholly unpredictable as far as future civilizations are concerned, public perception is that such facilities cannot be guaranteed to be absolutely secure for their envisaged lifetimes of tens of millennia.

  7. 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

  8. A magnetically switched kicker for proton extraction

    SciTech Connect (OSTI)

    Dinkel, J.; Biggs, J.

    1989-03-01

    The application of magnetic current amplification and switching techniques to the generation of precise high current pulses for switching magnets is described. The square loop characteristic of Metglas tape wound cores at high excitation levels provides excellent switching characteristics for microsecond pulses. The rugged and passive nature of this type pulser makes it possible to locate the final stages of amplification at the load for maximum efficiency. 12 refs., 8 figs.

  9. Improved Limit on the Permanent Electric Dipole Moment of {sup 199}Hg

    SciTech Connect (OSTI)

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

    2009-03-13

    We report the results of a new experimental search for a permanent electric dipole moment of {sup 199}Hg utilizing a stack of four vapor cells. We find d({sup 199}Hg)=(0.49{+-}1.29{sub stat}{+-}0.76{sub syst})x10{sup -29} e cm, and interpret this as a new upper bound, |d({sup 199}Hg)|<3.1x10{sup -29} e cm (95% C.L.). This result improves our previous {sup 199}Hg limit by a factor of 7, and can be used to set new constraints on CP violation in physics beyond the standard model.

  10. Container for reprocessing and permanent storage of spent nuclear fuel assemblies

    DOE Patents [OSTI]

    Forsberg, Charles W. (Oak Ridge, TN)

    1992-01-01

    A single canister process container for reprocessing and permanent storage of spent nuclear fuel assemblies comprising zirconium-based cladding and fuel, which process container comprises a collapsible container, having side walls that are made of a high temperature alloy and an array of collapsible support means wherein the container is capable of withstanding temperature necessary to oxidize the zirconium-based cladding and having sufficient ductility to maintain integrity when collapsed under pressure. The support means is also capable of maintaining their integrity at temperature necessary to oxide the zirconium-based cladding. The process container also has means to introduce and remove fluids to and from the container.

  11. EA-1895: Lolo Creek Permanent Weir Construction near town of Weippe, Clearwater County, Idaho

    Broader source: Energy.gov [DOE]

    DOE’s Bonneville Power Administration was preparing this EA to evaluate the potential environmental impacts of replacing an existing seasonal fish weir with a permanent weir, which would have been used to monitor federally-listed Snake River steelhead and collect spring Chinook salmon adults to support ongoing supplementation programs in the watershed. The Bureau of Land Management, a cooperating agency, preliminarily determined Lolo Creek to be suitable for Congressional designation into the Wild and Scenic River System. The EA included a Wild and Scenic River Section 7 analysis. This project was canceled.

  12. Determination of the Neutron Magnetic Moment

    DOE R&D Accomplishments [OSTI]

    Greene, G. L.; Ramsey, N. F.; Mampe, W.; Pendlebury, J. M.; Smith, K.; Dress, W. B.; Miller, P. D.; Perrin, P.

    1981-06-01

    The neutron magnetic moment has been measured with an improvement of a factor of 100 over the previous best measurement. Using a magnetic resonance spectrometer of the separated oscillatory field type capable of determining a resonance signal for both neutrons and protons (in flowing H{sub 2}O), we find ..mu..{sub n}/..mu..{sub p} = 0.68497935(17) (0.25 ppM). The neutron magnetic moment can also be expressed without loss of accuracy in a variety of other units.

  13. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    DOE Patents [OSTI]

    Coffey, Howard T.

    1993-01-01

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

  14. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    DOE Patents [OSTI]

    Coffey, H.T.

    1993-10-19

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle levitation. 3 figures.

  15. 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.

  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. Permanent total enclosures for VOC emission control at a RCRA transfer and storage facility

    SciTech Connect (OSTI)

    Davidson, S.L.; Rozmus, G.F.; Mehta, J.; Ardzinski, E. |

    1997-12-31

    Rollins Environmental Services operates a Transfer and Storage facility at their Allworth site in Mt. Pleasant, Tennessee. VOC control was originally accomplished by the use of close capture vents routed through a Regenerative Thermal Oxidizer. Capture efficiencies at several locations in the plant where hazardous waste was sampled and processed had been inadequate to fully meet EPA Clean Air Act Amendments Best Available Control Technology (BACT) or the requirements of OSHA 1910 Subpart Z--Toxic and Hazardous Substances standards and OSHA 1910.120(p)(5)--New Technology Program without the use of high levels of personal protective equipment (PPE) and extensive Industrial Hygiene monitoring. Therefore, a program was instituted to install permanent total enclosures in these areas with the goal of 100% capture of VOC`s. This paper presents the methodology by which this program was conceived and managed and the findings of the Industrial Safety and Health monitoring studies performed before and after the installation of the Permanent Total Enclosures and balancing of air flows in the system.

  18. 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.

  19. Scaling and Optimization of Magnetic Refrigeration for Commercial Building HVAC Systems Greater than 175 kW in Capacity

    SciTech Connect (OSTI)

    Abdelaziz, Omar; West, David L; Mallow, Anne M

    2012-01-01

    Heating, ventilation, air-conditioning and refrigeration (HVACR) account for approximately one- third of building energy consumption. Magnetic refrigeration presents an opportunity for significant energy savings and emissions reduction for serving the building heating, cooling, and refrigeration loads. In this paper, we have examined the magnet and MCE material requirements for scaling magnetic refrigeration systems for commercial building cooling applications. Scaling relationships governing the resources required for magnetic refrigeration systems have been developed. As system refrigeration capacity increases, the use of superconducting magnet systems becomes more applicable, and a comparison is presented of system requirements for permanent and superconducting (SC) magnetization systems. Included in this analysis is an investigation of the ability of superconducting magnet based systems to overcome the parasitic power penalty of the cryocooler used to keep SC windings at cryogenic temperatures. Scaling relationships were used to develop the initial specification for a SC magnet-based active magnetic regeneration (AMR) system. An optimized superconducting magnet was designed to support this system. In this analysis, we show that the SC magnet system consisting of two 0.38 m3 regenerators is capable of producing 285 kW of cooling power with a T of 28 K. A system COP of 4.02 including cryocooler and fan losses which illustrates that an SC magnet-based system can operate with efficiency comparable to traditional systems and deliver large cooling powers of 285.4 kW (81.2 Tons).

  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...

  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...

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. Iron dominated magnets

    SciTech Connect (OSTI)

    Fischer, G.E.

    1985-07-01

    These two lectures on iron dominated magnets are meant for the student of accelerator science and contain general treatments of the subjects design and construction. The material is arranged in the categories: General Concepts and Cost Considerations, Profile Configuration and Harmonics, Magnetic Measurements, a few examples of ''special magnets'' and Materials and Practices. Extensive literature is provided.

  7. A Study of Thermocurrent Induced Magnetic Fields in ILC Cavities

    SciTech Connect (OSTI)

    Crawford, Anthony C.; Cooley, Victoria

    2014-03-31

    The case of axisymmetric ILC type cavities with titanium helium vessels is investigated. A first order estimate for magnetic field within the SRF current layer is presented. The induced magnetic field is found to be not more than 1.4x10-8 Tesla = 0.14 milligauss for the case of axial symmetry. Magnetic fields due to symmetry breaking effects are discussed.

  8. 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.

  9. Nanoscale, multidimensional artificial magnet created

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

    an array of magnetic nano-islands along a geometry that is not found in natural magnets. ... an array of magnetic nano-islands along a geometry that is not found in natural magnets. ...

  10. The permanent electric dipole moment of thorium sulfide, ThS

    SciTech Connect (OSTI)

    Le, Anh; Steimle, Timothy C.; Heaven, Michael C.

    2014-01-14

    Numerous rotational lines of the (18.26)1-X{sup 1}Σ{sup +} band system of thorium sulfide, ThS, were recorded near 547.6 nm at a resolution of approximately 30 MHz. Measurements were made under field-free conditions, and in the presence of a static electric field. The field-free spectrum was analyzed to produce rotational and Λ-doubling parameters. The Stark shifts induced by the electric field were analyzed to determine permanent electric dipole moments, μ{sup -vector}{sub el}, of 4.58(10) D and 6.72(5) D for the X{sup 1}Σ{sup +} (v = 0) and (18.26)1 states, respectively. The results are compared with the predictions of previous and new electronic structure calculations for ThS, and the properties of isovalent ThO.

  11. Permanent luminescent micropatterns photoinduced by low-power ultraviolet irradiation in lithium fluoride

    SciTech Connect (OSTI)

    Vincenti, Maria Aurora; Almaviva, Salvatore; Montereali, Rosa Maria; Kalinowski, Hypolito Jose; Nogueira, Rogerio Nunes

    2006-12-11

    The permanent recording of regularly spaced, periodic, light-emitting submicrometric structures in gamma-ray irradiated LiF crystals has been obtained by low-power illumination with a continuous laser at 244 nm in a standard phase mask interferometer used for Bragg gratings registration in optical fibers. Selective bleaching of primary F electronic defects and aggregate F{sub 2} laser active color centers has been identified as the mechanism responsible of photoinduced spatial modulation of absorption and photoemission properties. The results look promising for the realization of micropatterns with refractive index and gain modulation on scale comparable with the optical wavelengths to easily integrate with miniaturized LiF-based structures.

  12. Container for reprocessing and permanent storage of spent nuclear fuel assemblies

    DOE Patents [OSTI]

    Forsberg, C.W.

    1992-03-24

    A single canister process container is described for reprocessing and permanent storage of spent nuclear fuel assemblies comprising zirconium-based cladding and fuel, which process container comprises a collapsible container, having side walls that are made of a high temperature alloy and an array of collapsible support means wherein the container is capable of withstanding temperature necessary to oxidize the zirconium-based cladding and having sufficient ductility to maintain integrity when collapsed under pressure. The support means is also capable of maintaining its integrity at a temperature necessary to oxidize the zirconium-based cladding. The process container also has means to introduce and remove fluids to and from the container. 10 figs.

  13. Testing and monitoring plan for the permanent isolation surface barrier prototype

    SciTech Connect (OSTI)

    Gee, G.W.; Cadwell, L.L.; Freeman, H.D.; Ligotke, M.W.; Link, S.O.; Romine, R.A.; Walters, W.H. Jr.

    1993-06-01

    This document is a testing and monitoring plan for a prototype barrier to be constructed at the Hanford Site in 1993. The prototype barrier is an aboveground structure engineered to demonstrate the basic features of an earthen cover system, designed to permanently isolate waste from the biosphere. These features include multiple layers of soil and rock materials and a low-permeability asphalt sublayer. The surface of the barrier consists of silt loam soil, vegetated with plants. The barrier sides are reinforced with rock or coarse earthen-fill to protect against wind and water erosion. The sublayers inhibit plant and animal intrusion and percolation of water. A series of tests will be conducted on the prototype over the next several years to evaluate barrier performance under extreme climatic conditions.

  14. eHXI: A permanently installed, hard x-ray imager for the National Ignition Facility

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

    Doppner, T.; Bachmann, B.; Albert, F.; Bell, P.; Burns, S.; Celeste, J.; Chow, R.; Divol, L.; Dewald, E. L.; Hohenberger, M.; et al

    2016-06-14

    We have designed and built a multi-pinhole imaging system for high energy x-rays (≥ 50 keV) that is permanently installed in the equatorial plane outside of the target chamber at the National Ignition Facility (NIF). It records absolutely-calibrated, time-integrated x-ray images with the same line-of-sight as the multi-channel, spatially integrating hard x-ray detector FFLEX [McDonald et al., Rev. Sci. Instrum. 75 (2004) 3753], having a side view of indirect-drive inertial confinement fusion (ICF) implosion targets. The equatorial hard x-ray imager (eHXI) has recorded images on the majority of ICF implosion experiments since May 2011. Lastly, eHXI provides valuable information onmore » hot electron distribution in hohlraum experiments, target alignment, potential hohlraum drive asymmetries and serves as a long term reference for the FFLEX diagnostics.« less

  15. Method for preparing high cure temperature rare earth iron compound magnetic material

    DOE Patents [OSTI]

    Huang, Yuhong; Wei, Qiang; Zheng, Haixing

    2002-01-01

    Insertion of light elements such as H,C, or N in the R.sub.2 Fe.sub.17 (R=rare earth metal) series has been found to modify the magnetic properties of these compounds, which thus become prospective candidates for high performance permanent magnets. The most spectacular changes are increases of the Curie temperature, T.sub.c, of the magnetization, M.sub.s, and of coercivity, H.sub.c, upon interstitial insertion. A preliminary product having a component R--Fe--C,N phase is produced by a chemical route. Rare earth metal and iron amides are synthesized followed by pyrolysis and sintering in an inert or reduced atmosphere, as a result of which, the R--Fe--C,N phases are formed. Fabrication of sintered rare earth iron nitride and carbonitride bulk magnet is impossible via conventional process due to the limitation of nitridation method.

  16. Measurement of the Magnet Blocks for SSRF Insertion Devices

    SciTech Connect (OSTI)

    He Yongzhou; Zhang Jidong; Zhou Qiaogen; Qian Zhenmei; Li Yang

    2010-06-23

    Two in-vacuum undulators IVU25s and one elliptically polarized undulator EPU100 have been developed for SSRF. Two IVU25s with the same hybrid design contain about 640 Sm{sub 2}Co{sub 17} magnet blocks and the dimension of blocks is 65 Wx25 Hx9 D. The EPU100 of the APPLE-II type contains about 690 NdFeB magnet blocks with the dimension of 35 Wx35 Hx25 D. This paper describes the magnetic measurements of these magnet blocks with the Helmholtz coil measurement system for IVU25 magnet blocks and the Hall probe measurement system for EPU100 magnet blocks. The measured maximum magnetic moment deviation and the maximum angle deviation are less than {+-}1.0% and 1.1 deg. respectively both for Sm{sub 2}Co{sub 17} blocks and NdFeB blocks and satisfy the specifications of undulators.

  17. Summary of key directives governing permanent disposal in a geologic repository

    SciTech Connect (OSTI)

    Sands, S.C. III

    1993-11-01

    This document was developed in support of the Idaho National Engineering Laboratory (INEL) Spent Fuel and Waste Management Technology Development Program (SF&WMTDP). It is largely comprised of flow diagrams summarizing the key regulatory requirements which govern permanent disposal in a geologic repository. The key purposes are (1) to provide an easy and effective tool for referencing or cross referencing federal directives (i.e., regulations and orders), (2) to provide a method for examining the requirements in one directive category against the requirements in another, and (3) to list actions that must be taken to ensure directive compliance. The document is categorically broken down into a Transportation section and a Mined Geologic Disposal System (MGDS) section to ensure that the interrelationship of the entire disposal system is considered. The Transportation section describes the transportation packaging requirements, testing methods, and safety requirements imposed on fissile material shipments. The MGDS section encompasses technical aspects involved in siting, licensing, waste interaction with the container, container design features, physical characteristics of the surrounding environment, facility design features, barrier systems, safety features, criticality considerations, migration restrictions, implementation guidelines, and so forth. For purposes of illustration, the worst case scenario is outlined. It is important that the approaches and considerations contained in this document be integrated into the efforts of the SF&WMTDP so that every applicable aspect of the regulatory requirements can be evaluated to avoid investing large sums of money into projects that do not take into account all of the aspects of permanent waste disposal. Not until an overall picture and clear understanding of these regulations is established can a basis be developed to govern the direction of future activities of the SF&WMTDP.

  18. Grain refinement of permanent mold cast copper base alloys. Final report

    SciTech Connect (OSTI)

    Sadayappan, M.; Thomson, J. P.; Elboujdaini, M.; Gu, G. Ping; Sahoo, M.

    2004-04-29

    Grain refinement behavior of copper alloys cast in permanent molds was investigated. This is one of the least studied subjects in copper alloy castings. Grain refinement is not widely practiced for leaded copper alloys cast in sand molds. Aluminum bronzes and high strength yellow brasses, cast in sand and permanent molds, were usually fine grained due to the presence of more than 2% iron. Grain refinement of the most common permanent mold casting alloys, leaded yellow brass and its lead-free replacement EnviroBrass III, is not universally accepted due to the perceived problem of hard spots in finished castings and for the same reason these alloys contain very low amounts of iron. The yellow brasses and Cu-Si alloys are gaining popularity in North America due to their low lead content and amenability for permanent mold casting. These alloys are prone to hot tearing in permanent mold casting. Grain refinement is one of the solutions for reducing this problem. However, to use this technique it is necessary to understand the mechanism of grain refinement and other issues involved in the process. The following issues were studied during this three year project funded by the US Department of Energy and the copper casting industry: (1) Effect of alloying additions on the grain size of Cu-Zn alloys and their interaction with grain refiners; (2) Effect of two grain refining elements, boron and zirconium, on the grain size of four copper alloys, yellow brass, EnviroBrass II, silicon brass and silicon bronze and the duration of their effect (fading); (3) Prediction of grain refinement using cooling curve analysis and use of this method as an on-line quality control tool; (4) Hard spot formation in yellow brass and EnviroBrass due to grain refinement; (5) Corrosion resistance of the grain refined alloys; (6) Transfer the technology to permanent mold casting foundries; It was found that alloying elements such as tin and zinc do not change the grain size of Cu-Zn alloys

  19. Ground Magnetics At Kilauea East Rift Area (Leslie, Et Al., 2004...

    Open Energy Info (EERE)

    regarding type of magnetic survey. References Stephen C. Leslie, Gregory F. Moore, Julia K. Morgan (2004) Internal Structure Of Puna Ridge- Evolution Of The Submarine...

  20. Memorandum Approval of a Permanent Variance Regarding Sprinklers and Fire Boundaries in Selected Areas of 22 1-H Canyon at the Savannah River Site

    Broader source: Energy.gov [DOE]

    Approval of a Permanent Variance Regarding Sprinklers and Fire Boundaries in Selected Areas of 22 1 -H Canyon at the Savannah River Site

  1. Memorandum, Approval of a Permanent Variance Regarding Sprinklers and Fire Boundaries in Selected Areas of 22 1-H Canyon at the Savannah River Site

    Broader source: Energy.gov [DOE]

    Approval of a Permanent Variance Regarding Fire Safety in Selected Areas of 221-H Canyon at the Savannah River Site UNDER SECRETARY OF ENERGY

  2. Magnetic properties of bulk, and rapidly solidified nanostructured (Nd1-xCex)2Fe14-yCoyB ribbons

    SciTech Connect (OSTI)

    Pathak, Arjun K.; Khan, M.; Gschneidner, Jr., K. A.; McCallum, R. W.; Zhou, L.; Sun, K.; Kramer, M. J.; Pecharsky, V. K.

    2015-11-06

    Magnetic properties of Ce and Co co-doped (Nd1-xCex)2Fe14-yCoyB compounds have been investigated both in bulk polycrystalline and rapidly solidified nanostructured ribbon forms. For certain Ce concentrations the materials exhibit spin re-orientation transitions below 140 K. The Curie temperatures, saturation magnetizations, and other magnetic properties relevant for applications as permanent magnets are controlled by Ce and Co substitutions for Nd and Fe, respectively. Most importantly, the results show that Ce, Co co-doped compounds are excellent replacements for several Dy-based high performance permanent magnets (dysprosium is one of the critical elements and is, therefore, in short supply). As a result, the high temperature (>375 K) magnetic properties for Nd–Ce–Fe–Co–B based alloys show promise not only as a replacement for Dy-doped Nd2Fe14B permanent magnets, but the new alloys also require significantly lower amounts of Nd, which too is the critical element that can be replaced by a more abundant Ce.

  3. Magnetic pipeline for coal and oil

    SciTech Connect (OSTI)

    Knolle, E.

    1998-07-01

    A 1994 analysis of the recorded costs of the Alaska oil pipeline, in a paper entitled Maglev Crude Oil Pipeline, (NASA CP-3247 pp. 671--684) concluded that, had the Knolle Magnetrans pipeline technology been available and used, some $10 million per day in transportation costs could have been saved over the 20 years of the Alaska oil pipeline's existence. This over 800 mile long pipeline requires about 500 horsepower per mile in pumping power, which together with the cost of the pipeline's capital investment consumes about one-third of the energy value of the pumped oil. This does not include the cost of getting the oil out of the ground. The reason maglev technology performs superior to conventional pipelines is because by magnetically levitating the oil into contact-free suspense, there is no drag-causing adhesion. In addition, by using permanent magnets in repulsion, suspension is achieved without using energy. Also, the pumped oil's adhesion to the inside of pipes limits its speed. In the case of the Alaska pipeline the speed is limited to about 7 miles per hour, which, with its 48-inch pipe diameter and 1200 psi pressure, pumps about 2 million barrels per day. The maglev system, as developed by Knolle Magnetrans, would transport oil in magnetically suspended sealed containers and, thus free of adhesion, at speeds 10 to 20 times faster. Furthermore, the diameter of the levitated containers can be made smaller with the same capacity, which makes the construction of the maglev system light and inexpensive. There are similar advantages when using maglev technology to transport coal. Also, a maglev system has advantages over railroads in mountainous regions where coal is primarily mined. A maglev pipeline can travel, all-year and all weather, in a straight line to the end-user, whereas railroads have difficult circuitous routes. In contrast, a maglev pipeline can climb over steep hills without much difficulty.

  4. Conventional magnetic superconductors

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

    Wolowiec, C. T.; White, B. D.; Maple, M. B.

    2015-07-01

    We discuss several classes of conventional magnetic superconductors including the ternary rhodium borides and molybdenum chalcogenides (or Chevrel phases), and the quaternary nickel-borocarbides. These materials exhibit some exotic phenomena related to the interplay between superconductivity and long-range magnetic order including: the coexistence of superconductivity and antiferromagnetic order; reentrant and double reentrant superconductivity, magnetic field induced superconductivity, and the formation of a sinusoidally-modulated magnetic state that coexists with superconductivity. We introduce the article with a discussion of the binary and pseudobinary superconducting materials containing magnetic impurities which at best exhibit short-range “glassy” magnetic order. Early experiments on these materials led tomore » the idea of a magnetic exchange interaction between the localized spins of magnetic impurity ions and the spins of the conduction electrons which plays an important role in understanding conventional magnetic superconductors. Furthermore, these advances provide a natural foundation for investigating unconventional superconductivity in heavy-fermion compounds, cuprates, and other classes of materials in which superconductivity coexists with, or is in proximity to, a magnetically-ordered phase.« less

  5. Extreme ultraviolet emission and confinement of tin plasmas in the presence of a magnetic field

    SciTech Connect (OSTI)

    Roy, Amitava E-mail: aroy@barc.gov.in; Murtaza Hassan, Syed; Harilal, Sivanandan S.; Hassanein, Ahmed; Endo, Akira; Mocek, Tomas

    2014-05-15

    We investigated the role of a guiding magnetic field on extreme ultraviolet (EUV) and ion emission from a laser produced Sn plasma for various laser pulse duration and intensity. For producing plasmas, planar slabs of pure Sn were irradiated with 1064?nm, Nd:YAG laser pulses with varying pulse duration (515?ns) and intensity. A magnetic trap was fabricated with the use of two neodymium permanent magnets which provided a magnetic field strength ?0.5?T along the plume expansion direction. Our results indicate that the EUV conversion efficiency do not depend significantly on applied axial magnetic field. Faraday Cup ion analysis of Sn plasma show that the ion flux reduces by a factor of ?5 with the application of an axial magnetic field. It was found that the plasma plume expand in the lateral direction with peak velocity measured to be ?1.2?cm/?s and reduced to ?0.75?cm/?s with the application of an axial magnetic field. The plume expansion features recorded using fast photography in the presence and absence of 0.5?T axial magnetic field are simulated using particle-in-cell code. Our simulation results qualitatively predict the plasma behavior.

  6. Magnetic field survey at PG&E photovoltaic sites

    SciTech Connect (OSTI)

    Chang, G.J.; Jennings, C.

    1994-08-01

    Public awareness has aroused concerns over the possible effects of magnetic fields on human health. While research continues to determine if magnetic fields do, in fact, affect human health, concerned individuals are requesting data on magnetic field sources in their environments to base personal decisions about limiting their exposure to these sources. Timely acceptance and implementation of photovoltaics (PV), particularly for distributed applications such as PV rooftops, windows, and vehicles, may be hampered by the lack of PV magnetic field data. To address this situation, magnetic flux density was measured around equipment at two PVUSA (Photovoltaics for Utility Scale Applications) project sites in Kerman and Davis, California. This report documents the data and compares the PV magnetic fields with published data on more prevalent magnetic field sources. Although not comprehensive, electric and magnetic field (EMF) data taken at PVUSA indicate that 60-Hz magnetic fields (the EMF type of greatest public concern) are significantly less for PV arrays than for household applications. Therefore, given the present EMF research knowledge, PV array EMF may not merit considerable concern. The PV system components exhibiting significant AC magnetic fields are the transformers and power conditioning units (PCUs). However, the AC magnetic fields associated with these components are localized and are not detected at PV system perimeters. Concern about transformer and PCU EMF would apply to several generation and storage technologies.

  7. Evaluation of Options for Permanent Geologic Disposal of Spent NuclearFuel and High-Level Radioactive Waste

    Office of Energy Efficiency and Renewable Energy (EERE)

    [In Support of a Comprehensive National Nuclear Fuel Cycle Strategy, Volumes I and II (Appendices)] This study provides a technical basis for informing policy decisions regarding strategies for the management and permanent disposal of spent nuclear fuel (SNF) and high-level radioactive waste (HLW) in the United States requiring geologic isolation.

  8. High-quality permanent draft genome sequence of the extremely osmotolerant diphenol degrading bacterium Halotalea alkalilenta AW-7T, and emended description of the genus Halotalea

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

    Ntougias, Spyridon; Lapidus, Alla; Copeland, Alex; Reddy, T. B. K.; Pati, Amrita; Ivanova, Natalia N.; Markowitz, Victor M.; Klenk, Hans-Peter; Woyke, Tanja; Fasseas, Constantinos; et al

    2015-08-13

    Members of the genus Halotalea (family Halomonadaceae) are of high significance since they can tolerate the greatest glucose and maltose concentrations ever reported for known bacteria and are involved in the degradation of industrial effluents. Here, the characteristics and the permanent-draft genome sequence and annotation of Halotalea alkalilenta AW-7T are described. The microorganism was sequenced as a part of the Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project at the DOE Joint Genome Institute, and it is the only strain within the genus Halotalea having its genome sequenced. The genome is 4,467,826 bp longmore » and consists of 40 scaffolds with 64.62 % average GC content. A total of 4,104 genes were predicted, comprising of 4,028 protein-coding and 76 RNA genes. Most protein-coding genes (87.79 %) were assigned to a putative function. Halotalea alkalilenta AW-7T encodes the catechol and protocatechuate degradation to β-ketoadipate via the β-ketoadipate and protocatechuate ortho-cleavage degradation pathway, and it possesses the genetic ability to detoxify fluoroacetate, cyanate and acrylonitrile. Lastly, an emended description of the genus Halotalea Ntougias et al. 2007 is also provided in order to describe the delayed fermentation ability of the type strain.« less

  9. High-quality permanent draft genome sequence of the extremely osmotolerant diphenol degrading bacterium Halotalea alkalilenta AW-7T, and emended description of the genus Halotalea

    SciTech Connect (OSTI)

    Ntougias, Spyridon; Lapidus, Alla; Copeland, Alex; Reddy, T. B. K.; Pati, Amrita; Ivanova, Natalia N.; Markowitz, Victor M.; Klenk, Hans-Peter; Woyke, Tanja; Fasseas, Constantinos; Kyrpides, Nikos C.; Zervakis, Georgios I.

    2015-08-13

    Members of the genus Halotalea (family Halomonadaceae) are of high significance since they can tolerate the greatest glucose and maltose concentrations ever reported for known bacteria and are involved in the degradation of industrial effluents. Here, the characteristics and the permanent-draft genome sequence and annotation of Halotalea alkalilenta AW-7T are described. The microorganism was sequenced as a part of the Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project at the DOE Joint Genome Institute, and it is the only strain within the genus Halotalea having its genome sequenced. The genome is 4,467,826 bp long and consists of 40 scaffolds with 64.62 % average GC content. A total of 4,104 genes were predicted, comprising of 4,028 protein-coding and 76 RNA genes. Most protein-coding genes (87.79 %) were assigned to a putative function. Halotalea alkalilenta AW-7T encodes the catechol and protocatechuate degradation to β-ketoadipate via the β-ketoadipate and protocatechuate ortho-cleavage degradation pathway, and it possesses the genetic ability to detoxify fluoroacetate, cyanate and acrylonitrile. Lastly, an emended description of the genus Halotalea Ntougias et al. 2007 is also provided in order to describe the delayed fermentation ability of the type strain.

  10. 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

  11. Low energy spread ion source with a coaxial magnetic filter

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Lee, Yung-Hee Yvette

    2000-01-01

    Multicusp ion sources are capable of producing ions with low axial energy spread which are necessary in applications such as ion projection lithography (IPL) and radioactive ion beam production. The addition of a radially extending magnetic filter consisting of a pair of permanent magnets to the multicusp source reduces the energy spread considerably due to the improvement in the uniformity of the axial plasma potential distribution in the discharge region. A coaxial multicusp ion source designed to further reduce the energy spread utilizes a cylindrical magnetic filter to achieve a more uniform axial plasma potential distribution. The coaxial magnetic filter divides the source chamber into an outer annular discharge region in which the plasma is produced and a coaxial inner ion extraction region into which the ions radially diffuse but from which ionizing electrons are excluded. The energy spread in the coaxial source has been measured to be 0.6 eV. Unlike other ion sources, the coaxial source has the capability of adjusting the radial plasma potential distribution and therefore the transverse ion temperature (or beam emittance).

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. Maximum mass of stable magnetized highly super-Chandrasekhar white dwarfs: stable solutions with varying magnetic fields

    SciTech Connect (OSTI)

    Das, Upasana; Mukhopadhyay, Banibrata E-mail: bm@physics.iisc.ernet.in

    2014-06-01

    We address the issue of stability of recently proposed significantly super-Chandrasekhar white dwarfs. We present stable solutions of magnetostatic equilibrium models for super-Chandrasekhar white dwarfs pertaining to various magnetic field profiles. This has been obtained by self-consistently including the effects of the magnetic pressure gradient and total magnetic density in a general relativistic framework. We estimate that the maximum stable mass of magnetized white dwarfs could be more than 3 solar mass. This is very useful to explain peculiar, overluminous type Ia supernovae which do not conform to the traditional Chandrasekhar mass-limit.

  3. Synthesis, crystal structure investigation and magnetism of the complex metal-rich boride series Cr{sub x}(Rh{sub 1-y}Ru{sub y}){sub 7-x}B{sub 3} (x=0.88-1; y=0-1) with Th{sub 7}Fe{sub 3}-type structure

    SciTech Connect (OSTI)

    Misse, Patrick R.N.; Mbarki, Mohammed; Fokwa, Boniface P.T.

    2012-08-15

    Powder samples and single crystals of the new complex boride series Cr{sub x}(Rh{sub 1-y}Ru{sub y}){sub 7-x}B{sub 3} (x=0.88-1; y=0-1) have been synthesized by arc-melting the elements under purified argon atmosphere on a water-cooled copper crucible. The products, which have metallic luster, were structurally characterized by single-crystal and powder X-ray diffraction as well as EDX measurements. Within the whole solid solution range the hexagonal Th{sub 7}Fe{sub 3} structure type (space group P6{sub 3}mc, no. 186, Z=2) was identified. Single-crystal structure refinement results indicate the presence of chromium at two sites (6c and 2b) of the available three metal Wyckoff sites, with a pronounced preference for the 6c site. An unexpected Rh/Ru site preference was found in the Ru-rich region only, leading to two different magnetic behaviors in the solid solution: The Rh-rich region shows a temperature-independent (Pauli) paramagnetism whereas an additional temperature-dependent paramagnetic component is found in the Ru-rich region. - Graphical abstract: The new complex boride series Cr{sub x}(Rh{sub 1-y}Ru{sub y}){sub 7-x}B{sub 3} (x=0.88-1; y=0-1) has been synthesized by arc melting the elements under purified argon atmosphere. Beside the 3d/4d site preference within the whole solid solution, an unexpected Rh/Ru site preference was found in the Ru-rich region only, leading to two different magnetic behaviors: The Rh-rich region shows a temperature-independent (Pauli) paramagnetism whereas an additional temperature-dependent paramagnetic component is found in the Ru-rich region. Highlights: Black-Right-Pointing-Pointer Synthesis of a new boride series fulfilling Vegard Acute-Accent s rule. Black-Right-Pointing-Pointer 3d/4d site preference. Black-Right-Pointing-Pointer Unexpected Ru/Rh site preference. Black-Right-Pointing-Pointer Rh-rich region is Pauli paramagnetic. Black-Right-Pointing-Pointer Ru-rich region is Pauli and temperature-dependent paramagnetic.

  4. Manufacturing the MFTF magnet

    SciTech Connect (OSTI)

    Dalder, E.N.C.; Hinkle, R.E.; Hodges, A.J.

    1980-10-13

    The Mirror Fusion Test Facility (MFTF) is a large mirror program experiment for magnetic fusion energy. It will combine and extend the near-classical plasma confinement achieved in 2XIIB with advanced neutral-beam and magnet technologies. The product of ion density and confinement time will be improved more than an order of magnitude, while the superconducting magnet weight will be extrapolated from 15 tons in Baseball II to 375 tons in MFTF. Recent reactor studies show that the MFTF will traverse much of the distance in magnet technology towards the reactor regime.

  5. Magnetic switches and circuits

    SciTech Connect (OSTI)

    Nunnally, W.C.

    1982-05-01

    This report outlines the use of saturable inductors as switches in lumped-element, magnetic-pulse compression circuits is discussed and the characteristic use of each is defined. In addition, the geometric constraints and magnetic pulse compression circuits used in short-pulse, low-inductance systems are considered. The scaling of presaturation leakage currents, magnetic energy losses, and switching times with geometrical and material parameters are developed to aid in evaluating magnetic pulse compression systems in a particular application. Finally, a scheme for increasing the couping coefficient in saturable stripline transformers is proposed to enable their use in the short-pulse, high-voltage regime.

  6. Electronic properties of graphene nano-flakes: Energy gap, permanent dipole, termination effect, and Raman spectroscopy

    SciTech Connect (OSTI)

    Singh, Sandeep Kumar Peeters, F. M.; Neek-Amal, M.

    2014-02-21

    The electronic properties of graphene nano-flakes (GNFs) with different edge passivation are investigated by using density functional theory. Passivation with F and H atoms is considered: C{sub N{sub c}} X{sub N{sub x}} (X = F or H). We studied GNFs with 10 < N{sub c} < 56 and limit ourselves to the lowest energy configurations. We found that: (i) the energy difference Δ between the highest occupied molecular orbital and the lowest unoccupied molecular orbital decreases with N{sub c}, (ii) topological defects (pentagon and heptagon) break the symmetry of the GNFs and enhance the electric polarization, (iii) the mutual interaction of bilayer GNFs can be understood by dipole-dipole interaction which were found sensitive to the relative orientation of the GNFs, (iv) the permanent dipoles depend on the edge terminated atom, while the energy gap is independent of it, and (v) the presence of heptagon and pentagon defects in the GNFs results in the largest difference between the energy of the spin-up and spin-down electrons which is larger for the H-passivated GNFs as compared to F-passivated GNFs. Our study shows clearly the effect of geometry, size, termination, and bilayer on the electronic properties of small GNFs. This study reveals important features of graphene nano-flakes which can be detected using Raman spectroscopy.

  7. Hanford Site Permanent Isolation Surface Barrier Development Program: Fiscal year 1992 and 1993 highlights

    SciTech Connect (OSTI)

    Cadwell, L.L.; Link, S.O.; Gee, G.W.

    1993-09-01

    The Hanford Site Permanent Isolation Surface Barrier Development Program was jointly developed by the Pacific Northwest Laboratory and Westinghouse Hanford Company to design and test an earthen cover system that can be used to inhibit water infiltration; plant, animal, and human intrusion; and wind and water erosion. Kaiser Engineers Hanford Company provided engineering design support for the program. Work on barrier design has been under way at Hanford for nearly 10 years. The comprehensive development of a long-term barrier, formerly the Hanford Site Protective Barrier Development Program, was initiated in FY 1986, and a general field-tested design is expected to be completed by FY 1998. Highlights of efforts in FY 1992 and FY 1993 included the resumption of field testing, the completion of the prototype barrier design, and the convening of an external peer review panel, which met twice with the barrier development team. The review panel provided helpful guidance on current and future barrier development activities, while commending the program for its significant technical contributions to innovative barrier technology development.

  8. Characterization of fold defects in AZ91D and AE42 magnesium alloy permanent mold castings

    SciTech Connect (OSTI)

    Bichler, L. [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. E., Toronto, M5B 2K3 (Canada); Ravindran, C., E-mail: rravindr@ryerson.ca [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. E., Toronto, M5B 2K3 (Canada)

    2010-03-15

    Casting premium-quality magnesium alloy components for aerospace and automotive applications poses unique challenges. Magnesium alloys are known to freeze rapidly prior to filling a casting cavity, resulting in misruns and cold shuts. In addition, melt oxidation, solute segregation and turbulent metal flow during casting contribute to the formation of fold defects. In this research, formation of fold defects in AZ91D and AE42 magnesium alloys cast via the permanent mold casting process was investigated. Computer simulations of the casting process predicted the development of a turbulent metal flow in a critical casting region with abrupt geometrical transitions. SEM and light optical microscopy examinations revealed the presence of folds in this region for both alloys. However, each alloy exhibited a unique mechanism responsible for fold formation. In the AZ91D alloy, melt oxidation and velocity gradients in the critical casting region prevented fusion of merging metal front streams. In the AE42 alloy, limited solubility of rare-earth intermetallic compounds in the {alpha}-Mg phase resulted in segregation of Al{sub 2}RE particles at the leading edge of a metal front and created microstructural inhomogeneity across the fold.

  9. Fast dose kernel interpolation using Fourier transform with application to permanent prostate brachytherapy dosimetry

    SciTech Connect (OSTI)

    Liu, Derek Sloboda, Ron S.

    2014-05-15

    Purpose: Boyer and Mok proposed a fast calculation method employing the Fourier transform (FT), for which calculation time is independent of the number of seeds but seed placement is restricted to calculation grid points. Here an interpolation method is described enabling unrestricted seed placement while preserving the computational efficiency of the original method. Methods: The Iodine-125 seed dose kernel was sampled and selected values were modified to optimize interpolation accuracy for clinically relevant doses. For each seed, the kernel was shifted to the nearest grid point via convolution with a unit impulse, implemented in the Fourier domain. The remaining fractional shift was performed using a piecewise third-order Lagrange filter. Results: Implementation of the interpolation method greatly improved FT-based dose calculation accuracy. The dose distribution was accurate to within 2% beyond 3 mm from each seed. Isodose contours were indistinguishable from explicit TG-43 calculation. Dose-volume metric errors were negligible. Computation time for the FT interpolation method was essentially the same as Boyer's method. Conclusions: A FT interpolation method for permanent prostate brachytherapy TG-43 dose calculation was developed which expands upon Boyer's original method and enables unrestricted seed placement. The proposed method substantially improves the clinically relevant dose accuracy with negligible additional computation cost, preserving the efficiency of the original method.

  10. The search for permanent electric dipole moments, in particular for the one of the neutron

    ScienceCinema (OSTI)

    None

    2011-10-06

    Nonzero permanent electric dipole moments (EDM) of fundamental systems like particles, nuclei, atoms or molecules violate parity and time reversal invariance. Invoking the CPT theorem, time reversal violation implies CP violation. Although CP-violation is implemented in the standard electro-weak theory, EDM generated this way remain undetectably small. However, this CP-violation also appears to fail explaining the observed baryon asymmetry of our universe. Extensions of the standard theory usually include new CP violating phases which often lead to the prediciton of larger EDM. EDM searches in different systems are complementary and various efforts worldwide are underway, but no finite value could be established yet. An improved search for the EDM of the neutron requires, among other things, much better statistics. At PSI, we are presently commissioning a new high intensity source of ultracold neutrons. At the same time, with an international collaboration, we are setting up for a new measurement of the neutron EDM which is starting this year.

  11. Submergible barge retrievable storage and permanent disposal system for radioactive waste

    DOE Patents [OSTI]

    Goldsberry, Fred L.; Cawley, William E.

    1981-01-01

    A submergible barge and process for submerging and storing radioactive waste material along a seabed. A submergible barge receives individual packages of radwaste within segregated cells. The cells are formed integrally within the barge, preferably surrounded by reinforced concrete. The cells are individually sealed by a concrete decking and by concrete hatch covers. Seawater may be vented into the cells for cooling, through an integral vent arrangement. The vent ducts may be attached to pumps when the barge is bouyant. The ducts are also arranged to promote passive ventilation of the cells when the barge is submerged. Packages of the radwaste are loaded into individual cells within the barge. The cells are then sealed and the barge is towed to the designated disposal-storage site. There, the individual cells are flooded and the barge will begin descent controlled by a powered submarine control device to the seabed storage site. The submerged barge will rest on the seabed permanently or until recovered by a submarine control device.

  12. Cold test facility for 1.8 m superconducting model magnets at the SSCL

    SciTech Connect (OSTI)

    LaBarge, A.; Althaus, R.; Bird, R.; Baron, J.; Chagnon, J.; Deak, M.; Scott, M.; Vasilyev, V.; Williamson, G.

    1993-05-01

    A new facility has been constructed to measure the characteristic features of superconducting model magnets and cable at cryogenic temperatures--a function which supports the design and development process for building full-scale accelerator magnets. There are multiple systems operating in concert to test the model magnets, namely, cryogenic, magnet power, data acquisition and system control. A typical model magnet test includes the following items: warm measurements of magnet coils, strain gauges and voltage taps; hipot testing of insulation integrity; cooling with liquid nitrogen and then liquid helium; measuring quench current and magnetic field; (5) magnet warm-up. While the magnet is being cooled to 4.22 K, the mechanical stress is monitored through strain gauges. Current is then ramped into the magnet until it reaches some maximum value and the magnet transitions from the superconducting state to the normal state. Normal-zone propagation is monitored using voltage taps on the magnet coils during this process, thus indicating where the transition began. The current ramp is usually repeated until a plateau current is reached, where the magnet has mechanically settled. Many variations on the current ramping sequence are used to study different phenomena associated with magnet performance, e.g. magnetization hysteresis, eddy current losses, cryogenic stability, etc. A warm bore cryostat with a rotating coil is inserted in the magnet to measure field strength and homogeneity. These types of measurements yield multipole and current versus field data.

  13. 4 Tesla Magnet Facility | Argonne National Laboratory

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

    4 Tesla Magnet Facility 4 Tesla Magnet Facility Argonne researchers recently acquired two decommissioned magnets from magnetic resonance imaging (MRI) scanners from hospitals in ...

  14. MULTISCALE DYNAMICS OF SOLAR MAGNETIC STRUCTURES

    SciTech Connect (OSTI)

    Uritsky, Vadim M.; Davila, Joseph M.

    2012-03-20

    Multiscale topological complexity of the solar magnetic field is among the primary factors controlling energy release in the corona, including associated processes in the photospheric and chromospheric boundaries. We present a new approach for analyzing multiscale behavior of the photospheric magnetic flux underlying these dynamics as depicted by a sequence of high-resolution solar magnetograms. The approach involves two basic processing steps: (1) identification of timing and location of magnetic flux origin and demise events (as defined by DeForest et al.) by tracking spatiotemporal evolution of unipolar and bipolar photospheric regions, and (2) analysis of collective behavior of the detected magnetic events using a generalized version of the Grassberger-Procaccia correlation integral algorithm. The scale-free nature of the developed algorithms makes it possible to characterize the dynamics of the photospheric network across a wide range of distances and relaxation times. Three types of photospheric conditions are considered to test the method: a quiet photosphere, a solar active region (NOAA 10365) in a quiescent non-flaring state, and the same active region during a period of M-class flares. The results obtained show (1) the presence of a topologically complex asymmetrically fragmented magnetic network in the quiet photosphere driven by meso- and supergranulation, (2) the formation of non-potential magnetic structures with complex polarity separation lines inside the active region, and (3) statistical signatures of canceling bipolar magnetic structures coinciding with flaring activity in the active region. Each of these effects can represent an unstable magnetic configuration acting as an energy source for coronal dissipation and heating.

  15. 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.

  16. EXOTIC MAGNETS FOR ACCELERATORS.

    SciTech Connect (OSTI)

    WANDERER, P.

    2005-09-18

    Over the last few years, several novel magnet designs have been introduced to meet the requirements of new, high performance accelerators and beam lines. For example, the FAIR project at GSI requires superconducting magnets ramped at high rates ({approx} 4 T/s) in order to achieve the design intensity. Magnets for the RIA and FAIR projects and for the next generation of LHC interaction regions will need to withstand high doses of radiation. Helical magnets are required to maintain and control the polarization of high energy protons at RHIC. In other cases, novel magnets have been designed in response to limited budgets and space. For example, it is planned to use combined function superconducting magnets for the 50 GeV proton transport line at J-PARC to satisfy both budget and performance requirements. Novel coil winding methods have been developed for short, large aperture magnets such as those used in the insertion region upgrade at BEPC. This paper will highlight the novel features of these exotic magnets.

  17. 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.

  18. 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.

  19. 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.

  20. 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...

  1. Influence of plasma loss area on transport of charged particles through a transverse magnetic field

    SciTech Connect (OSTI)

    Das, B. K.; Chakraborty, M. [Centre of Plasma Physics-Institute for Plasma Research, Tepesia, Kamrup, Assam (India); Bandyopadhyay, M. [ITER-India, Institute for Plasma Research, Gandhinagar, Gujarat (India)

    2012-01-15

    Plasma transport in a double plasma device from the source region to the target region through a physical window comprising of electrically grounded magnet channels (filled with permanent magnet bars) for transverse magnetic field (TMF) and a pair of stainless steel (SS) plates is studied and presented in this manuscript. The study has relevance in negative ion source research and development where both TMF created by magnet channels and bias plate are used. The experiment is performed in two stages. In the first stage, a TMF is introduced between the two regions along with the SS plates, and corresponding plasma parameter data in the two regions are recorded by changing the distance between the TMF channels. In the second stage, the TMF is withdrawn from the system, and corresponding data are taken by changing the separation between the SS plates. The experimental results are then compared with a theoretical model. In the presence of TMF, where electrons are magnetized and ions are un-magnetized, it is observed that plasma transport perpendicular to the TMF is dominated by the ambipolar diffusion of ions. In the absence of TMF, plasma is un-magnetized, and plasma transport through the SS window aperture is almost independent of open area of the SS window.

  2. Non-magnetic organic/inorganic spin injector at room temperature

    SciTech Connect (OSTI)

    Mathew, Shinto P.; Mondal, Prakash Chandra; Naaman, Ron; Moshe, Hagay; Mastai, Yitzhak

    2014-12-15

    Spin injection into solid-state devices is commonly performed by use of ferromagnetic metal electrodes. Here, we present a spin injector design without permanent magnet; rather, the spin selectivity is determined by a chiral tunneling barrier. The chiral tunneling barrier is composed of an ultrathin Al{sub 2}O{sub 3} layer that is deposited on top of a chiral self-assembled monolayer (SAM), which consists of cysteine or oligopeptide molecules. The experimentally observed magnetoresistance can be up to 20% at room temperature, and it displays an uncommon asymmetric curve as a function of the applied magnetic field. These findings show that the spin injector transmits only one spin orientation, independent of external magnetic field. The sign of the magnetoresistance depends on the handedness of the molecules in the SAM, which act as a spin filter, and the magnitude of the magnetoresistance depends only weakly on temperature.

  3. Hanford Permanent Isolation Barrier Program: Asphalt technology data and status report - FY 1994

    SciTech Connect (OSTI)

    Freeman, H.D.; Romine, R.A.; Zacher, A.H.

    1994-09-01

    The asphalt layer within the Hanford Permanent Isolation Barrier (HPIB) is an important component of the overall design. This layer provides a RCRA equivalent backup to the overlying earthen layers in the unlikely event that these layers are not able to reduce the infiltration rate to less than 0.05 cm/yr. There is only limited amount of information on using asphalt for a moisture infiltration barrier over the long times required by the HPIB. Therefore, a number of activities are under way, as part of the Barrier Development Program, to obtain data on the performance of asphalt as a moisture barrier in a buried environment over a 1000-year period. These activities include (1) determining RCRA equivalency, (2) measurement of physical properties, (3) measurement of aging characteristics, and (4) relationship to ancient asphalt analogs. During FY 1994 progress was made on all of these activities. Studies were conducted both in the laboratory and on the prototype barrier constructed over the 216-B-57 crib in the 200 East Area on the Hanford Site. This report presents results obtained from the asphalt technology tasks during FY 1994. Also included are updates to planned activities for asphalt analogs and monitoring the asphalt test pad near the prototype barrier. Measurements of hydraulic conductivity on the HMAC portion of the prototype barrier show that the asphalt layers easily meet the RCRA standard of 1 {times} 10{sup -7} cm/s. In-place measurements using a new field falling head technique show an average of 3.66 {times} 10{sup -8} cm/s, while cores taken from the north end of the prototype and measured in a laboratory setup averaged 1.29 {times} 10{sup -9} cm/s. Measurements made on the fluid applied asphalt membrane (polymer-modified asphalt) show an extremely low permeability of less than 1 {times} 10{sup -11} cm/s.

  4. 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

  5. The superconducting solenoid magnets for MICE

    SciTech Connect (OSTI)

    Green, Michael A.

    2002-12-22

    The Muon Ionization Cooling Experiment (MICE) is a channel of superconducting solenoid magnets. The magnets in MICE are around the RF cavities, absorbers (liquid or solid) and the primary particle detectors [1], [2]. The MICE superconducting solenoid system consists of eighteen coils that are grouped in three types of magnet assemblies. The cooling channel consists of two complete cell of an SFOFO cooling channel. Each cell consists of a focusing coil pair around an absorber and a coupling coil around a RF cavity that re-accelerates the muons to their original momentum. At the ends of the experiment are uniform field solenoids for the particle detectors and a set of matching coils used to match the muon beam to the cooling cells. Three absorbers are used instead of two in order to shield the detectors from dark currents generated by the RF cavities at high operating acceleration gradients.

  6. 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...

  7. 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....

  8. 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,...

  9. PLUTONIUM OUGHT TO PRODUCE MAGNETISM.

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

    ... valence states. 1663 October 2015 5 electrical conductivity changes drastically in the presence of a magnetic field, allowing for new spintronic and magnetic- sensing devices. ...

  10. 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.

  11. Condensed Matter and Magnet Science

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

    nondestructive pulsed magnets up to 100 tesla Thermoacoustics and fluid dynamics ... Nanotechnologies play 2:54 World's first 100 Tesla non-destructive magnetic field NSF BES

  12. magnets | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    magnets NNSA-lab-created new magnets will power renewable technology The Ion Beam Materials Laboratory at NNSA's Los Alamos National Laboratory (LANL) works to characterize and ...

  13. 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. ...

  14. Progress on Superconducting Magnets for the MICE Cooling Channel

    SciTech Connect (OSTI)

    Green, Michael A; Virostek, Steve P.; Li, Derun; Zisman, Michael S.; Wang, Li; Pan, Heng; Wu, Hong; Guo, XingLong; Xu, FengYu; Liu, X. K.; Zheng, S. X.; Bradshaw, Thomas; Baynham, Elwyn; Cobb, John; Lau, Wing; Lau, Peter; Yang, Stephanie Q.

    2009-09-09

    The muon ionization cooling experiment (MICE) consists of a target, a beam line, a pion decay channel, the MICE cooling channel. Superconducting magnets are used in the pion decay channel and the MICE cooling channel. This report describes the MICE cooling channel magnets and the progress in the design and fabrication of these magnets. The MICE cooling channel consists of three types of superconducting solenoids; the spectrometer solenoids, the coupling solenoids and the focusing solenoids. The three types of magnets are being fabricated in he United States, China, and the United Kingdom respectively. The spectrometer magnets are used to analyze the muon beam before and after muon cooling. The coupling magnets couple the focusing sections and keep the muon beam contained within the iris of the RF cavities that re used to recover the muon momentum lost during ionization cooling. The focusing magnets focus the muon beam in the center of a liquid hydrogen absorber. The first of the cooling channel magnets will be operational in MICE in the spring of 2010.

  15. Electric field-controlled magnetization in bilayered magnetic films for magnetoelectric memory

    SciTech Connect (OSTI)

    Yang, Wei-Gang; Morley, Nicola A.; Rainforth, W. Mark

    2015-07-21

    Bilayered magnetic films (Co{sub 50}Fe{sub 50} (CoFe)/Metglas) were RF sputtered on both (001)-oriented and (011)-oriented PMN-PT (lead magnesium niobate-lead titanate) substrates. Electric field-controlled magnetization changes were observed in all these samples: 65 nm CoFe/24 nm Metglas/(001) PMN-PT, 65 nm CoFe/24 nm Metglas/(011) PMN-PT, and 30 nm CoFe/12 nm Metglas/(011) PMN-PT. The maximum magnetic remanence ratio change (ΔM{sub r}/M{sub s}) was 46% for CoFe/Metglas/(001) PMN-PT. In this heterostructure, the electric-field created two new non-volatile switchable remanence states and the as-grown remanence state was altered permanently. High-resolution transmission electron microscopy images show a sharp and smooth interface between Metglas and substrate and conversely a rougher interface was observed between Metglas and CoFe films. In the 30 nm CoFe/12 nm Metglas/(011) PMN-PT sample, a large ΔM{sub r}/M{sub s} of 80% along the [100] direction was measured, while the ΔM{sub r}/M{sub s} along the [01-1] direction was 60% at the applied electric field of 5 kV/cm, corresponding to a giant magnetoelectric coupling constant α = μ{sub o}ΔM{sub r}/E = 2.9 × 10{sup −6} s/m.

  16. 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.

  17. 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.

  18. Magnetostatic focal spot correction for x-ray tubes operating in strong magnetic fields using iterative optimization

    SciTech Connect (OSTI)

    Lillaney, Prasheel; Shin, Mihye; Conolly, Steven M.; Fahrig, Rebecca

    2012-09-15

    Purpose: Combining x-ray fluoroscopy and MR imaging systems for guidance of interventional procedures has become more commonplace. By designing an x-ray tube that is immune to the magnetic fields outside of the MR bore, the two systems can be placed in close proximity to each other. A major obstacle to robust x-ray tube design is correcting for the effects of the magnetic fields on the x-ray tube focal spot. A potential solution is to design active shielding that locally cancels the magnetic fields near the focal spot. Methods: An iterative optimization algorithm is implemented to design resistive active shielding coils that will be placed outside the x-ray tube insert. The optimization procedure attempts to minimize the power consumption of the shielding coils while satisfying magnetic field homogeneity constraints. The algorithm is composed of a linear programming step and a nonlinear programming step that are interleaved with each other. The coil results are verified using a finite element space charge simulation of the electron beam inside the x-ray tube. To alleviate heating concerns an optimized coil solution is derived that includes a neodymium permanent magnet. Any demagnetization of the permanent magnet is calculated prior to solving for the optimized coils. The temperature dynamics of the coil solutions are calculated using a lumped parameter model, which is used to estimate operation times of the coils before temperature failure. Results: For a magnetic field strength of 88 mT, the algorithm solves for coils that consume 588 A/cm{sup 2}. This specific coil geometry can operate for 15 min continuously before reaching temperature failure. By including a neodymium magnet in the design the current density drops to 337 A/cm{sup 2}, which increases the operation time to 59 min. Space charge simulations verify that the coil designs are effective, but for oblique x-ray tube geometries there is still distortion of the focal spot shape along with deflections of

  19. Charge trapping and de-trapping in isolated CdSe/ZnS nanocrystals under an external electric field: Indirect evidence for a permanent dipole moment

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

    Zang, Huidong; Cristea, Mihail; Shen, Xuan; Liu, Mingzhao; Camino, Fernando; Cotlet, Mircea

    2015-08-05

    Single nanoparticle studies of charge trapping and de-trapping in core/shell CdSe/ZnS nanocrystals incorporated into an insulating matrix and subjected to an external electric field demonstrate the ability to reversibly modulate the exciton dynamics and photoluminescence blinking while providing indirect evidence for the existence of a permanent ground state dipole moment in such nanocrystals. A model assuming the presence of energetically deep charge traps physically aligned along the direction of the permanent dipole is proposed in order to explain the dynamics of nanocrystal blinking in the presence of a permanent dipole moment.

  20. 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...

  1. 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.

  2. Giant Controllable Magnetization ...

    Office of Scientific and Technical Information (OSTI)

    ... Figure 1(b) (red line) also shows how applying a saturation magnetic field of 1T, then ... in the nuclear scattering length density (NSLD) profiles as the red curve in Figure 2(c). ...

  3. 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.

  4. 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.

  5. 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.

  6. Environmentally Benign and Permanent Modifications to Prevent Biofouling on Marine and Hydrokinetic Devices

    SciTech Connect (OSTI)

    Zheng Zhang

    2012-04-19

    Semprus Biosciences is developing environmentally benign and permanent modifications to prevent biofouling on Marine and Hydrokinetic (MHK) devices. Biofouling, including growth on external surfaces by bacteria, algae, barnacles, mussels, and other marine organisms, accumulate quickly on MHK devices, causing mechanical wear and changes in performance. Biofouling on crucial components of hydrokinetic devices, such as rotors, generators, and turbines, imposes substantial mass and hydrodynamic loading with associated efficiency loss and maintenance costs. Most antifouling coatings leach toxic ingredients, such as copper and tributyltin, through an eroding process, but increasingly stringent regulation of biocides has led to interest in the development of non-biocidal technologies to control fouling. Semprus Biosciences research team is developing modifications to prevent fouling from a broad spectrum of organisms on devices of all shapes, sizes, and materials for the life of the product. The research team designed and developed betaine-based polymers as novel underwater coatings to resist the attachment of marine organisms. Different betaine-based monomers and polymers were synthesized and incorporated within various coating formulations. The formulations and application methods were developed on aluminum panels with required adhesion strength and mechanical properties. The coating polymers were chemically stable under UV, hydrolytic and oxidative environments. The sulfobetaine formulations are applicable as nonleaching and stable underwater coatings. For the first time, coating formulations modified with highly packed sulfobetaine polymers were prepared and demonstrated resistance to a broad spectrum of marine organisms. Assays for comparing nonfouling performance were developed to evaluate protein adsorption and bacteria attachment. Barnacle settlement and removal were evaluated and a 60-day field test was performed. Silicone substrates including a commercial

  7. ARM - Measurement - Cloud type

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

    Measurement : Cloud type Cloud type such as cirrus, stratus, cumulus etc Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the...

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  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. Frontiers in imaging magnetism with polarized x-rays

    SciTech Connect (OSTI)

    Fischer, Peter

    2015-01-08

    Although magnetic imaging with polarized x-rays is a rather young scientific discipline, the various types of established x-ray microscopes have already taken an important role in state-of-the-art characterization of the properties and behavior of spin textures in advanced materials. The opportunities ahead will be to obtain in a unique way indispensable multidimensional information of the structure, dynamics and composition of scientifically interesting and technologically relevant magnetic materials.

  1. SISGR-MuSR Investigations of Magnetic Semiconductors for Spintronics

    Office of Scientific and Technical Information (OSTI)

    Applications (Technical Report) | SciTech Connect Technical Report: SISGR-MuSR Investigations of Magnetic Semiconductors for Spintronics Applications Citation Details In-Document Search Title: SISGR-MuSR Investigations of Magnetic Semiconductors for Spintronics Applications Authors: Lichti, Roger Publication Date: 2014-03-27 OSTI Identifier: 1148701 Report Number(s): Final Report DOE Contract Number: SC0001769 Resource Type: Technical Report Research Org: Texas Tech University Sponsoring

  2. C:\WINNT\Profiles\caseys\DESKTOP\L T R C\PICs Program\Permanent Markers\PM Test Plan.PDF

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

    0-3175 Permanent Markers Testing Program Plan September 28, 2000 United States Department of Energy Waste Isolation Pilot Plant Carlsbad Area Office Carlsbad, New Mexico Permanent Markers Testing Program Plan Waste Isolation Pilot Plant Carlsbad, New Mexico DOE/WIPP 00-3175 September 28, 2000 DOE/WIPP 00-3175 -i- Table of Contents List of Abbreviations and Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv 1.0 Introduction . . . . . . . . . . . .

  3. Temperature Measurements in the Magnetic Measurement Facility

    SciTech Connect (OSTI)

    Wolf, Zachary

    2010-12-13

    Several key LCLS undulator parameter values depend strongly on temperature primarily because of the permanent magnet material the undulators are constructed with. The undulators will be tuned to have specific parameter values in the Magnetic Measurement Facility (MMF). Consequently, it is necessary for the temperature of the MMF to remain fairly constant. Requirements on undulator temperature have been established. When in use, the undulator temperature will be in the range 20.0 {+-} 0.2 C. In the MMF, the undulator tuning will be done at 20.0 {+-} 0.1 C. For special studies, the MMF temperature set point can be changed to a value between 18 C and 23 C with stability of {+-}0.1 C. In order to ensure that the MMF temperature requirements are met, the MMF must have a system to measure temperatures. The accuracy of the MMF temperature measurement system must be better than the {+-}0.1 C undulator tuning temperature tolerance, and is taken to be {+-}0.01 C. The temperature measurement system for the MMF is under construction. It is similar to a prototype system we built two years ago in the Sector 10 alignment lab at SLAC. At that time, our goal was to measure the lab temperature to {+-}0.1 C. The system has worked well for two years and has maintained its accuracy. For the MMF system, we propose better sensors and a more extensive calibration program to achieve the factor of 10 increase in accuracy. In this note we describe the measurement system under construction. We motivate our choice of system components and give an overview of the system. Most of the software for the system has been written and will be discussed. We discuss error sources in temperature measurements and show how these errors have been dealt with. The calibration system is described in detail. All the LCLS undulators must be tuned in the Magnetic Measurement Facility at the same temperature to within {+-}0.1 C. In order to ensure this, we are building a system to measure the temperature of the

  4. Effect of eddy current in the laminations on the magnet field

    SciTech Connect (OSTI)

    Chung, Y.; Galayda, J.

    1992-04-01

    In this note theory and measurements of the effect of the eddy current in the laminations on the magnet field are presented. The theory assumes a simple solenoid-type magnet with laminated iron core and ignores the end field effect. The measurements were made on the input voltage and current, and the dipole component of the magnetic field in the middle of the magnet bore. The amplitude and phase relations between these quantities give the field attenuation factor, phase delay, and resistance and inductance of the magnet as functions of frequency. Comparisons of results with theory are discussed.

  5. 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)

  6. 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.

  7. High-quality permanent draft genome sequence of the Parapiptadenia rigida-nodulating Cupriavidus sp. strain UYPR2.512

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

    De Meyer, Sofie E.; Fabiano, Elena; Tian, Rui; Van Berkum, Peter; Seshadri, Rekha; Reddy, T. B. K.; Markowitz, Victor; Ivanova, Natalia N.; Pati, Amrita; Woyke, Tanja; et al

    2015-04-11

    Cupriavidus sp. strain UYPR2.512 is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from a root nodule of Parapiptadenia rigida grown in soils from a native forest of Uruguay. Here we describe the features of Cupriavidus sp. strain UYPR2.512, together with sequence and annotation. We find the 7,858,949 bp high-quality permanent draft genome is arranged in 365 scaffolds of 369 contigs, contains 7,411 protein-coding genes and 76 RNA-only encoding genes, and is part of the GEBA-RNB project proposal.

  8. 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.

  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. 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...

  12. 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...

  13. 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...

  14. Types of Reuse

    Broader source: Energy.gov [DOE]

    The following provides greater detail regarding the types of reuse pursued for LM sites. It should be noted that many actual reuses combine several types of the uses listed below.

  15. Types of Radiation Exposure

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

    External Irradiation Contamination Incorporation Biological Effects of Acute, Total Body Irradiation Managing Radiation Emergencies Procedure Demonstration Types of radiation ...

  16. 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 We report Knight shift experiments on the superconducting heavy electron material CeCoIn{sub 5} that allow one to track with some precision the behavior of the heavy electron

  17. 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

  18. 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

  19. Cost impact of discretionary alternatives. OSM Permanent Regulations 30 CFR, Chapter 7. Volume 1. Executive Summary and methodology. Final report

    SciTech Connect (OSTI)

    Not Available

    1990-06-11

    The report was prepared by D'Appolonia Consulting Engineers, Inc. (D'Appolonia) for the Office of Surface Mining Reclamation and Enforcement (OSM) to assess the probable impacts on coal production costs of numerous discretionary issues involved in drafting the permanent regulations for implementation of the Surface Mining Control and Reclamation Act of 1977 (the Act). The results of the engineering cost study were used directly in OSM's Regulatory Analysis (RA) developed in compliance with Executive Order 12044. The final RA was published in March 1979 and is available from the OSM. The report details those analyses conducted by D'Appolonia and used in the RA. The results of the study are not meant to reflect the complete cost or economic impact of the Act or the resulting OSM regulations. The results do provide a basis for evaluating the relative impact of the various alternatives considered by OSM during development of the permanent regulatory program. The discretionary issues analyzed in the report pertain to both surface and underground mining activities. The volume presents the general methods of approach and final results of the study, while Volumes II and III present the individual analyses of each issue for surface and underground mines, respectively.

  20. Sub-micron fracture mechanism in silica-based glass activated by permanent densification from high-strain loading

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

    Wereszczak, Andrew A.; Waters, Shirley B.; Parten, Randy J.; Pye, L. David

    2016-04-26

    Several silica-based glasses were fractured at high strain energy via drop-weight testing on small specimens. A cylindrical specimen geometry was chosen to promote initially simple, axisymmetric, and uniform compressive loading. The imposed uniaxial compressive strain at impact was sufficiently high to qualitatively cause permanent densification. Produced fragments were collected for postmortem and a fraction of them, for all the silica-based glasses, consistently had distinct sub-micron-sized fractures (~ 300–1000 nm), designated here as “microkernels”, on their surfaces. They would most often appear as a sub-micron pore on the fragment - apparently if the microkernel had popped out as a consequence ofmore » the local crack plane running through it, tensile-strain release, and the associated formation of the fragment it was on. No fractographic evidence was found to show the microkernels were associated with local failure initiation. However, their positioning and habit sometimes suggested they were associated with localized crack branching and that they could have influenced secondary fracturing that occurred during overall crushing and comminution and associated fragment size and shape creation. Furthermore, the size range of these microkernels is much too small to affect structural flexure strength of these glasses for most applications but are of a size and concentration that may affect their ballistic, shock, crush, and comminution responses when permanent densification is concomitantly occurring.« less

  1. Postdoc Appointment Types

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

    Appointment Types Postdoc Appointment Types Most postdocs will be offered a postdoctoral research associate appointment. Each year, approximately 30 Postdoctoral Fellow appointments, including the Distinguished Fellows, are awarded. Postdoc appointment types offer world of possibilities Meet the current LANL Distinguished Postdocs Research Associates Research Associates pursue research as part of ongoing LANL science and engineering programs. Sponsored postdoctoral candidate packages are

  2. Magnetism in LithiumOxygen Discharge Product

    SciTech Connect (OSTI)

    Lu, Jun; Jung, Hun-Ji; Lau, Kah Chun; Zhang, Zhengcheng; Schlueter, John A.; Du, Peng; Assary, Rajeev S.; Greeley, Jeffrey P.; Ferguson, Glen A.; Wang, Hsien-Hau; Hassoun, Jusef; Iddir, Hakim; Zhou, Jigang; Zuin, Lucia; Hu, Yongfeng; Sun, Yang-Kook; Scrosati, Bruno; Curtiss, Larry A.; Amine, Khalil

    2013-05-13

    Nonaqueous lithiumoxygen batteries have a much superior theoretical gravimetric energy density compared to conventional lithium-ion batteries, and thus could render long-range electric vehicles a reality. A molecular-level understanding of the reversible formation of lithium peroxide in these batteries, the properties of major/minor discharge products, and the stability of the nonaqueous electrolytes is required to achieve successful lithiumoxygen batteries. We demonstrate that the major discharge product formed in the lithiumoxygen cell, lithium peroxide, exhibits a magnetic moment. These results are based on dc-magnetization measurements and a lithium oxygen cell containing an ether-based electrolyte. The results are unexpected because bulk lithium peroxide has a significant band gap. Density functional calculations predict that superoxide- type surface oxygen groups with unpaired electrons exist on stoichiometric lithium peroxide crystalline surfaces and on nanoparticle surfaces; these computational results are consistent with the magnetic measurement of the discharged lithium peroxide product as well as EPR measurements on commercial lithium peroxide. The presence of superoxide-type surface oxygen groups with spin can play a role in the reversible formation and decomposition of lithium peroxide as well as the reversible formation and decomposition of electrolyte molecules.

  3. Contribution to the development of DOE ARM Climate Modeling Best Estimate Data (CMBE) products: Satellite data over the ARM permanent and AMF sites: Final Report

    SciTech Connect (OSTI)

    Xie, B; Dong, X; Xie, S

    2012-05-18

    To support the LLNL ARM infrastructure team Climate Modeling Best Estimate (CMBE) data development, the University of North Dakota (UND)'s group will provide the LLNL team the NASA CERES and ISCCP satellite retrieved cloud and radiative properties for the periods when they are available over the ARM permanent research sites. The current available datasets, to date, are as follows: the CERES/TERRA during 200003-200812; the CERES/AQUA during 200207-200712; and the ISCCP during 199601-200806. The detailed parameters list below: (1) CERES Shortwave radiative fluxes (net and downwelling); (2) CERES Longwave radiative fluxes (upwelling) - (items 1 & 2 include both all-sky and clear-sky fluxes); (3) CERES Layered clouds (total, high, middle, and low); (4) CERES Cloud thickness; (5) CERES Effective cloud height; (6) CERES cloud microphysical/optical properties; (7) ISCCP optical depth cloud top pressure matrix; (8) ISCCP derived cloud types (r.g., cirrus, stratus, etc.); and (9) ISCCP infrared derived cloud top pressures. (10) The UND group shall apply necessary quality checks to the original CERES and ISCCP data to remove suspicious data points. The temporal resolution for CERES data should be all available satellite overpasses over the ARM sites; for ISCCP data, it should be 3-hourly. The spatial resolution is the closest satellite field of view observations to the ARM surface sites. All the provided satellite data should be in a format that is consistent with the current ARM CMBE dataset so that the satellite data can be easily merged into the CMBE dataset.

  4. 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.

  5. 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.

  6. 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.

  7. Nuclear magnetic resonance imaging

    SciTech Connect (OSTI)

    Young, I.R.

    1984-07-03

    A method of imaging a body by nuclear magnetic resonance wherein volume scanning of a region of the body is achieved by scanning a first planar slice of the region and at least one further slice of the region in the relaxation time for the scan of the first slice.

  8. WE-D-17A-04: Magnetically Focused Proton Irradiation of Small Volume Targets

    SciTech Connect (OSTI)

    McAuley, G; Slater, J; Wroe, A

    2014-06-15

    Purpose: To explore the advantages of magnetic focusing for small volume proton irradiations and the potential clinical benefits for radiosurgery targets. The primary goal is to create narrow elongated proton beams of elliptical cross section with superior dose delivery characteristics compared to current delivery modalities (eg, collimated beams). In addition, more general beam shapes are also under investigation. Methods: Two prototype magnets consisting of 24 segments of samarium-cobalt (Sm2Co17) permanent magnetic material adhered into hollow cylinders were manufactured for testing. A single focusing magnet was placed on a positioning track on our Gantry 1 treatment table and 15 mm diameter proton beams with energies and modulation relevant to clinical radiosurgery applications (127 to 186 MeV, and 0 to 30 mm modulation) were delivered to a terminal water tank. Beam dose distributions were measured using a PTW diode detector and Gafchromic EBT2 film. Longitudinal and transverse dose profiles were analyzed and compared to data from Monte Carlo simulations analogous to the experimental setup. Results: The narrow elongated focused beam spots showed high elliptical symmetry indicating high magnet quality. In addition, when compared to unfocused beams, peak-to-entrance depth dose ratios were 11 to 14% larger (depending on presence or extent of modulation), and minor axis penumbras were 11 to 20% smaller (again depending on modulation) for focused beams. These results suggest that the use of rare earth magnet assemblies is practical and could improve dose-sparing of normal tissue and organs at risk while delivering enhanced dose to small proton radiosurgery targets. Conclusion: Quadrapole rare earth magnetic assemblies are a promising and inexpensive method to counteract particle out scatter that tends to degrade the peak to entrance performance of small field proton beams. Knowledge gained from current experiments will inform the design of a prototype treatment

  9. 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...

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. Magnetic lens apparatus for use in high-resolution scanning electron microscopes and lithographic processes

    DOE Patents [OSTI]

    Crewe, Albert V. (Dune Acres, IN)

    2000-01-01

    Disclosed are lens apparatus in which a beam of charged particlesis brought to a focus by means of a magnetic field, the lens being situated behind the target position. In illustrative embodiments, a lens apparatus is employed in a scanning electron microscopeas the sole lens for high-resolution focusing of an electron beam, and in particular, an electron beam having an accelerating voltage of from about 10 to about 30,000 V. In one embodiment, the lens apparatus comprises an electrically-conducting coil arranged around the axis of the beam and a magnetic pole piece extending along the axis of the beam at least within the space surrounded by the coil. In other embodiments, the lens apparatus comprises a magnetic dipole or virtual magnetic monopole fabricated from a variety of materials, including permanent magnets, superconducting coils, and magnetizable spheres and needles contained within an energy-conducting coil. Multiple-array lens apparatus are also disclosed for simultaneous and/or consecutive imaging of multiple images on single or multiple specimens. The invention further provides apparatus, methods, and devices useful in focusing charged particle beams for lithographic processes.

  15. Magnetic Force Microscopy Study of Zr2Co11 -Based Nanocrystalline Materials: Effect of Mo Addition

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

    Yue, Lanping; Jin, Yunlong; Zhang, Wenyong; Sellmyer, David J.

    2015-01-01

    Tmore » he addition of Molybdenum was used to modify the nanostructure and enhance coercivity of rare-earth-free Zr2Co11-based nanocrystalline permanent magnets. he effect of Mo addition on magnetic domain structures of melt spun nanocrystalline Zr16Co84-xMox(x=0, 0.5, 1, 1.5, and 2.0) ribbons has been investigated. It was found that magnetic properties and local domain structures are strongly influenced by Mo doping. he coercivity of the samples increases with the increase in Mo content (x≤1.5). he maximum energy product(BH)maxincreases with increasingxfrom 0.5 MGOe forx=0to a maximum value of 4.2 MGOe forx=1.5. he smallest domain size with a relatively short magnetic correlation length of 128 nm and largest root-mean-square phase shiftΦrmsvalue of 0.66° are observed for thex=1.5. he optimal Mo addition promotes magnetic domain structure refinement and thus leads to a significant increase in coercivity and energy product in this sample.« less

  16. 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.

  17. International magnetic pulse compression

    SciTech Connect (OSTI)

    Kirbie, H.C.; Newton, M.A.; Siemens, P.D.

    1991-04-01

    Although pulsed-power engineering traditionally has been practiced by a fairly small, close community in the areas of defense and energy research, it is becoming more common in high-power, high-energy commercial pursuits such as material processing and lasers. This paper is a synopsis of the Feb. 12--14, 1990 workshop on magnetic switching as it applies primarily to pulse compression (power transformation). During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card -- its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

  18. 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.

  19. Magnetic interactions in manganese oxide

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

    Manganese oxide Magnetic interactions in manganese oxide Revealing the mechanism of 'superexchange' May 24, 2016 manganese oxide Manganese oxide Revealing the Nature of Magnetic Interactions in Manganese Oxide For nearly 60 years, scientists have been trying to determine how manganese oxide (MnO) achieves its long-range magnetic order of alternating up and down electron spins. Now, a team of scientists has used their recently developed mathematical approach to study the short-range magnetic

  20. 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