National Library of Energy BETA

Sample records for type permanent magnet

  1. Electromagnetic acceleration of permanent magnets

    E-Print Network [OSTI]

    Dolya, S N

    2015-01-01

    We consider the acceleration of the permanent magnets, consisting of neodymium iron boron by means of the running magnetic field gradient. It is shown that the specific magnetic moment per nucleon in neodymium iron boron is determined by the remained magnetization of the substance. The maximum accessable gradient of the magnetic field accelerating the permanent magnets is determined by the coercive force thirty kilogauss. For the neodymium iron boron magnets this gradient is equal to twenty kilogauss divided by one centimeter. The finite velocity of the magnets six kilometers per second, the length of acceleration is six hundred thirty-seven meters.

  2. 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. __________________________________________________

  3. 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.

  4. 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...

  5. Modular Permanent Magnet Machine Based on Soft Magnetic *** Burgess-Norton Mfg.Co.

    E-Print Network [OSTI]

    Lipo, Thomas

    . The rotor structure can be designed with surface permanent magnet (SPM) or internal permanent magnet (IPM

  6. 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.

  7. Calculation Method of Permanent Magnet Pickups for Electric Guitars

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    in the 1930s, when Rickenbacker fitted out a guitar with a magnet and coils, thus designing the first magnetic to look at the types of magnetic circuit for the guitar pickups. We consider in this paper the most usual1 Calculation Method of Permanent Magnet Pickups for Electric Guitars G. Lemarquand and V

  8. Analytical Method of Torque Calculation for Interior Permanent Magnet Synchronous Machines

    E-Print Network [OSTI]

    Tolbert, Leon M.

    Analytical Method of Torque Calculation for Interior Permanent Magnet Synchronous Machines Seong (FEA). Also, this method can be applied to any type of synchronous machine. Index Terms-- equivalent circuit, inductance, permanent magnet machine, synchronous motors, torque. I. NOMENCLATURE BFE brushless

  9. Permanent magnet edge-field quadrupole

    DOE Patents [OSTI]

    Tatchyn, Roman O. (Mountain View, CA)

    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.

  10. Modeling and optimization of permanent magnetic motors

    E-Print Network [OSTI]

    Pinkham, Andrew P

    2008-01-01

    This thesis develops analytic models for the prediction and optimization of radial-flux permanent magnet motor torque and efficiency. It also facilitates the design optimization of electromagnetically-powered rotorcraft ...

  11. Dovetail spoke internal permanent magnet machine

    DOE Patents [OSTI]

    Alexander, James Pellegrino (Ballston Lake, NY); EL-Refaie, Ayman Mohamed Fawzi (Niskayuna, NY); Lokhandwalla, Murtuza (Clifton Park, NY); Shah, Manoj Ramprasad (Latham, NY); VanDam, Jeremy Daniel (West Coxsackie, NY)

    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.

  12. 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.

  13. Batch fabrication of precision miniature permanent magnets

    DOE Patents [OSTI]

    Christenson, Todd R. (Albuquerque, NM); Garino, Terry J. (Albuquerque, NM); Venturini, Eugene L. (Albuquerque, NM)

    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.

  14. Performance improvement of permanent magnet ac motors 

    E-Print Network [OSTI]

    Parsa, Leila

    2005-08-29

    positively to output torque, a five-phase permanent magnet motor with quasi-rectangular back-EMF waveform is supplied with combined fundamental and third harmonic of currents. For modeling and analysis of the motor a 0 3 3 1 1 q d q d frame of reference...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. Strong permanent magnet-assisted electromagnetic undulator

    DOE Patents [OSTI]

    Halbach, Klaus (Berkeley, CA)

    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.

  4. Feedback Control of a Permanent Magnet Biased, Homopolar Magnetic Bearing System 

    E-Print Network [OSTI]

    Wadhvani, Vishal Ashok

    2011-08-08

    was to develop a permanent magnet biased magnetic bearing system using high temperature (HT) permanent magnets (PM) developed by EEC. This system was designed for high performance, high temperature (1000F) and high speed applications. The entire system consisted...

  5. Permanent magnet helicon source for ion propulsion Francis F. Chen

    E-Print Network [OSTI]

    Chen, Francis F.

    Permanent magnet helicon source for ion propulsion Francis F. Chen Electrical Engineering that great savings in size and weight can be obtained by using specially designed permanent magnets (PMs by at least two groups for generating ions for space propulsion: the HDLT concept at the Australian National

  6. Magnetic Patterning of Permanent-Magnet Rotors for Microscale Motor/Generators

    E-Print Network [OSTI]

    Magnetic Patterning of Permanent-Magnet Rotors for Microscale Motor/Generators I. Zana* , F, USA Abstract We present and characterize a process to pattern magnetic poles on small permanent-magnet, this approach uses a ferromagnetic magnetizing head (MH) and an externally applied magnetic field, and it offers

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

    E-Print Network [OSTI]

    Waldmann, Ole

    2011-01-01

    Permanent-Magnet Mi- crowave Ion Source for a Compact High-Yield Neutron Generator,Permanent-Magnet Microwave Ion Source for a Sealed-Tube Neutron Generatorgenerator. Microwave ion sources, however, A permanent-magnet

  8. Relativistic Engine Based on a Permanent Magnet

    E-Print Network [OSTI]

    Tuval, Miron

    2015-01-01

    Newton's third law states that any action is countered by a reaction of equal magnitude but opposite direction. The total force in a system not affected by external forces is thus zero. However, according to the principles of relativity a signal can not propagate at speeds exceeding the speed of light. Hence the action cannot be generated at the same time with the reaction due to the relativity of simultaneity, thus the total force cannot be null at a given time. The following is a continuation of a previous paper \\cite{Tuval} in which we analyzed the relativistic effects in a system of two current conducting loops. Here the analysis is repeated but one of the loops is replaced by a permanent magnet. It should be emphasized that although momentum can be created in the {\\bf material} part of the system as described in the following work momentum can not be created in the {\\bf physical} system, hence for any momentum that is acquired by matter an opposite momentum is attributed to the electromagnetic field.

  9. Relativistic Engine Based on a Permanent Magnet

    E-Print Network [OSTI]

    Miron Tuval; Asher Yahalom

    2015-06-30

    Newton's third law states that any action is countered by a reaction of equal magnitude but opposite direction. The total force in a system not affected by external forces is thus zero. However, according to the principles of relativity a signal can not propagate at speeds exceeding the speed of light. Hence the action cannot be generated at the same time with the reaction due to the relativity of simultaneity, thus the total force cannot be null at a given time. The following is a continuation of a previous paper \\cite{Tuval} in which we analyzed the relativistic effects in a system of two current conducting loops. Here the analysis is repeated but one of the loops is replaced by a permanent magnet. It should be emphasized that although momentum can be created in the {\\bf material} part of the system as described in the following work momentum can not be created in the {\\bf physical} system, hence for any momentum that is acquired by matter an opposite momentum is attributed to the electromagnetic field.

  10. 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.

  11. Method and apparatus for assembling permanent magnet rotors

    DOE Patents [OSTI]

    Hsu, John S. (Oak Ridge, TN); Adams, Donald J. (Knoxville, TN)

    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.

  12. Phase-controlled rectification for permanent-magnet downhole alternators

    E-Print Network [OSTI]

    Maher, Patrick L

    2008-01-01

    This thesis develops a method of phase-controlled rectification to be used with permanent-magnet downhole alternators. The design faces unique challenges imposed by the downhole environment. The thesis discusses the design, ...

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

    SciTech Connect (OSTI)

    Yamamoto, Akiyasu, E-mail: yamamoto@appchem.t.u-tokyo.ac.jp [The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Ishihara, Atsushi; Tomita, Masaru [Railway Technical Research Institute, 2-8-38 Hikari, Kokubunji, Tokyo 185-8540 (Japan); Kishio, Kohji [The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan)

    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.

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

    DOE Patents [OSTI]

    Hsu, John S. (Oak Ridge, TN)

    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).

  15. 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).

  16. Determination of Rotor Temperature for an Interior Permanent Magnet Synchronous

    E-Print Network [OSTI]

    Noé, Reinhold

    of the magnet material monitoring its temperature also helps to increase the accuracy of the estimated torque [1Determination of Rotor Temperature for an Interior Permanent Magnet Synchronous Machine Using@lea.upb.de, boecker@lea.upb.de Abstract--In this paper an enhanced method to de- termine the rotor temperature

  17. 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.

  18. 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.

  19. Dynamic Jiles-Atherton Model for Determining the Magnetic Power Loss at High Frequency in Permanent Magnet Machines

    E-Print Network [OSTI]

    Du, Ruoyang; Robertson, Paul

    2014-12-18

    —Finite element methods (FEM), Magnetic hysteresis, Magnetic losses, Magnetization, Permanent magnet machines, Permanent magnet motors, Permanent magnet generators. I. INTRODUCTION HE magnetic power losses in ferromagnetic materials have been continuously... made to the original dynamic Jiles-Atherton model in order to make it work correctly for laminations in high frequency permanent magnet synchronous machines (PMSMs), such as BLDC motors. Since the working frequencies of modern BLDC motors...

  20. 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.

  1. 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.

  2. Spin echo without an external permanent magnetic field

    E-Print Network [OSTI]

    Joakim Bergli; Leonid Glazman

    2006-09-19

    The spin echo techniques aim at the elimination of the effect of a random magnetic field on the spin evolution. These techniques conventionally utlize the application of a permanent field which is much stronger than the random one. The strong field, however, may also modify the magnetic response of the medium containing the spins, thus altering their ``natural'' dynamics. We suggest an iterative scheme for generating a sequence of pulses which create an echo without an external permanent field. The approximation to the ideal echo improves with the sequence length.

  3. 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.

  4. Permanent Magnetic Materials Discovery | The Ames Laboratory

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

    magnetic materials find wide applications in energy generation. The materials providing best performances (e.g., high energy product), such as NdFeB, contains a large weight...

  5. Real-Time Capable Methods to Determine the Magnet Temperature of Permanent Magnet

    E-Print Network [OSTI]

    Noé, Reinhold

    ) is widely spread in industrial applications. Due to the development of high energy permanent magnet Motors -- A Review Oliver Wallscheid, Tobias Huber, Wilhelm Peters, Joachim B¨ocker Power Electronics}@lea.upb.de Abstract--The permanent magnet synchronous motor (PMSM) is widely used in highly utilised automotive

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

    E-Print Network [OSTI]

    Khesin, Boris A.

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

  7. Wireless Control of Magnetic Helical Microrobots using a Rotating-Permanent-Magnet Manipulator

    E-Print Network [OSTI]

    Bamberg, Stacy Morris

    ]. Helical propulsion using magnetic fields is particularly promising for medical microrobots. HelicalWireless Control of Magnetic Helical Microrobots using a Rotating-Permanent-Magnet Manipulator Thomas W. R. Fountain, Prem V. Kailat, and Jake J. Abbott Abstract-- Magnetic helical medical microrobots

  8. 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 tolerance levels determined, some form of magnetic shielding would be required.

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

    E-Print Network [OSTI]

    Waldmann, Ole

    2011-01-01

    A Permanent-Magnet Microwave Ion Source for a Compact High-A Permanent-Magnet Microwave Ion Source for a Compact High-on the development of a microwave ion source that will be

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

    DOE Patents [OSTI]

    Roesler, Alexander W. (Tijeras, NM); Christenson, Todd R. (Albuquerque, NM)

    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.

  11. Optimum Control for Interior Permanent Magnet Synchronous Motors (IPMSM) in Constant

    E-Print Network [OSTI]

    Noé, Reinhold

    Optimum Control for Interior Permanent Magnet Synchronous Motors (IPMSM) in Constant Torque and Electrical Drives, Paderborn, Germany Abstract--Interior Permanent Magnet Synchronous Motors (IPMSM) gain-power speed area. A widespread electrical machine used for this purpose is the Interior Permanent Magnet

  12. Direct Torque Control for Interior Permanent Magnet Synchronous Motors with Respect to Optimal Efficiency

    E-Print Network [OSTI]

    Noé, Reinhold

    applications. Highly utilized machines are often designed as interior permanent magnet synchronous motorsDirect Torque Control for Interior Permanent Magnet Synchronous Motors with Respect to Optimal@lea.upb.de, boecker@lea.upb.de URL: http://wwwlea.upb.de Keywords «Interior permanent magnet synchronous motor

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

    E-Print Network [OSTI]

    Waldmann, Ole

    2011-01-01

    permanent-magnet microwave ion source for the high-yield neutron generator.Permanent-Magnet Microwave Ion Source for a Compact High-Yield Neutron GeneratorPermanent-Magnet Microwave Ion Source for a Compact High-Yield Neutron Generator ?

  14. Performance of An Adjustable Strength Permanent Magnet Quadrupole

    SciTech Connect (OSTI)

    Gottschalk, S.C.; DeHart, T.E.; Kangas, K.W.; /STI Optronics, Bellevue; Spencer, C.M.; /SLAC; 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.

  15. Permanent magnet machine with windings having strand transposition

    DOE Patents [OSTI]

    Qu, Ronghai (Clifton Park, NY); Jansen, Patrick Lee (Scotia, NY)

    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.

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy Bills andOrder 422.1, CONDUCT PDepartmentOrderEnergy Permanent Magnet

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

    SciTech Connect (OSTI)

    Krzyzewski, S. P.; Akin, T. G.; Dahal, Parshuram; Abraham, E. R. I. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019 (United States)

    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.

  18. 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 currents in ferromagnetic pipes and tubes. Since this is a new inspection method, both theory and experiment were used to determine fundamental capabilities and limitations. Fundamental finite element modeling analysis and experimental investigations performed during this development have led to the derivation of a first order analytical equation for designing rotating magnetizers to induce current and positioning sensors to record signals from anomalies. Experimental results confirm the analytical equation and the finite element calculations provide a firm basis for the design of RPMI systems. Experimental results have shown that metal loss anomalies and wall thickness variations can be detected with an array of sensors that measure local changes in the magnetic field produced by the induced current flowing in the material. The design exploits the phenomenon that circumferential currents are easily detectable at distances well away from the magnets. Current changes at anomalies were detectable with commercial low cost Hall Effect sensors. Commercial analog to digital converters can be used to measure the sensor output and data analysis can be performed in real time using PC computer systems. The technology was successfully demonstrated during two blind benchmark tests where numerous metal loss defects were detected. For this inspection technology, the detection threshold is a function of wall thickness and corrosion depth. For thinner materials, the detection threshold was experimentally shown to be comparable to magnetic flux leakage. For wall thicknesses greater than three tenths of an inch, the detection threshold increases with wall thickness. The potential for metal loss anomaly sizing was demonstrated in the second benchmarking study, again with accuracy comparable to existing magnetic flux leakage technologies. The rotating permanent magnet system has the potential for inspecting unpiggable pipelines since the magnetizer configurations can be sufficiently small with respect to the bore of the pipe to pass obstructions that limit the application of many i

  19. Interior Permanent Magnet Reluctance Machine with Brushless Field Excitation

    SciTech Connect (OSTI)

    Wiles, R.H.

    2005-10-07

    In a conventional permanent magnet (PM) machine, the air-gap flux produced by the PM is fixed. It is difficult to enhance the air-gap flux density due to limitations of the PM in a series-magnetic circuit. However, the air-gap flux density can be weakened by using power electronic field weakening to the limit of demagnetization of the PMs. This paper presents the test results of controlling the PM air-gap flux density through the use of a stationary brushless excitation coil in a reluctance interior permanent magnet with brushless field excitation (RIPM-BFE) motor. Through the use of this technology the air-gap flux density can be either enhanced or weakened. There is no concern with demagnetizing the PMs during field weakening. The leakage flux of the excitation coil through the PMs is blocked. The prototype motor built on this principle confirms the concept of flux enhancement and weakening through the use of excitation coils.

  20. High temperature, permanent magnet biased, homopolar magnetic bearing actuator 

    E-Print Network [OSTI]

    Hossain, Mohammad Ahsan

    2006-10-30

    The EEC (Electron Energy Corporation) in conjunction with the National Aeronautics and Space Administration is researching the magnetic bearings for an alternative to conventional journal or ball bearings. The purpose of this research was to design...

  1. 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.

  2. Highly Charged Ions in Rare Earth Permanent Magnet Penning Traps

    E-Print Network [OSTI]

    Guise, Nicholas D; Tan, Joseph N

    2013-01-01

    A newly constructed apparatus at the National Institute of Standards and Technology (NIST) is designed for the isolation, manipulation, and study of highly charged ions. Highly charged ions are produced in the NIST electron-beam ion trap (EBIT), extracted through a beamline that selects a single mass/charge species, then captured in a compact Penning trap. The magnetic field of the trap is generated by cylindrical NdFeB permanent magnets integrated into its electrodes. In a room-temperature prototype trap with a single NdFeB magnet, species including Ne10+ and N7+ were confined with storage times of order 1 second, showing the potential of this setup for manipulation and spectroscopy of highly charged ions in a controlled environment. Ion capture has since been demonstrated with similar storage times in a more-elaborate Penning trap that integrates two coaxial NdFeB magnets for improved B-field homogeneity. Ongoing experiments utilize a second-generation apparatus that incorporates this two-magnet Penning tra...

  3. Monitoring Critical Temperatures in Permanent Magnet Synchronous Motors Using Low-Order

    E-Print Network [OSTI]

    Noé, Reinhold

    Monitoring Critical Temperatures in Permanent Magnet Synchronous Motors Using Low-Order Thermal motors is crucial for preventing shortened motor life spans due to excessive thermal stress. With regard to interior permanent magnet synchronous motors (IPMSM), critical temperatures typically occur in the magnets

  4. The use of a permanent magnet for water content measurements of wood chips

    E-Print Network [OSTI]

    2001-01-01

    of a Permanent Magnet for Water Content Measurements of Wooda device that measures the water content of wood chips, pulpsystem. The results of water content measurements in wood

  5. 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...

  6. A "permanent" high-temperature superconducting magnet operated in thermal communication with a mass of solid nitrogen

    E-Print Network [OSTI]

    Haid, Benjamin J. (Benjamin John Jerome), 1974-

    2001-01-01

    This thesis explores a new design for a portable "permanent" superconducting magnet system. The design is an alternative to permanent low-temperature superconducting (LTS) magnet systems where the magnet is cooled by a ...

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

    DOE Patents [OSTI]

    Ramesh, Ramamoorthy (Berkeley, CA); Thomas, Gareth (Berkeley, CA)

    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.

  8. 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, otherwise a necessary step for oxidation and corrosion resistance. Stability of these thin films was attributed to the reduction of each RE's respective oxide during processing; recognizing that fluoride compounds exhibit a slightly higher (negative) free energy driving force for formation. Formation of RE-type fluorides on the surface was evidenced through x-ray photoelectron spectroscopy (XPS). Concurrent research with auger electron spectroscopy has been attempted to accurately quantify the depth of fluoride formation in order to grasp the extent of fluorination reactions with spherical and flake particulate. Gas fusion analysis on coated powders (dia. <45 {micro}m) from an optimized experiment indicated an as-atomized oxygen concentration of 343ppm, where typical, nonpassivated RE atomized alloys exhibit an average of 1800ppm oxygen. Thermogravimetric analysis (TGA) on the same powder revealed a decreased rate of oxidation at elevated temperatures up to 300 C, compared to similar uncoated powder.

  9. 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.

  10. Design and analysis of a permanent magnet generator for naval applications

    E-Print Network [OSTI]

    Rucker, Jonathan E. (Jonathan Estill)

    2005-01-01

    This paper discusses the electrical and magnetic design and analysis of a permanent magnet generation module for naval applications. Numerous design issues are addressed and several issues are raised about the potential ...

  11. 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 today’s 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.

  12. Current Controller with Defined Dynamic Behavior for an Interior Permanent Magnet

    E-Print Network [OSTI]

    Noé, Reinhold

    Current Controller with Defined Dynamic Behavior for an Interior Permanent Magnet Synchronous Motor combustion vehicles already provide. Today's modern HEV and EV mostly include interior permanent magnet]. The required torque, which is the reference variable for these applications, is generated by choosing

  13. Size Reduction of Permanent Magnet Generators for Wind Turbines with Higher Energy Density

    E-Print Network [OSTI]

    McCalley, James D.

    . Currently, the U.S has 60GW installed wind capacity; this translates to 3.6% of total electricity generation [1]. The U.S. Department of Energy has proposed that 20% of electricity generation in the U.S. should to DFIGs. II. PERMANENT MAGNET GENERATORS A. Fundamental Principles In PMGs, the permanent magnets provide

  14. Aalborg Universitet Flicker Mitigation by Speed Control of Permanent Magnet Synchronous Generator

    E-Print Network [OSTI]

    Hu, Weihao

    Aalborg Universitet Flicker Mitigation by Speed Control of Permanent Magnet Synchronous Generator Synchronous Generator Variable-Speed Wind Turbines. Energies, 6(8), 3807-3821. 10.3390/en6083807 General.mdpi.com/journal/energies Article Flicker Mitigation by Speed Control of Permanent Magnet Synchronous Generator Variable-Speed Wind

  15. 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.

  16. 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.

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

    SciTech Connect (OSTI)

    Oikawa, Kohei, E-mail: oikawa@ecei.tohoku.ac.jp; Saito, Yuta; Komizunai, Shota; Takahashi, Kazunori; Ando, Akira [Department of Electrical Engineering, Tohoku University, Sendai 980-8579 (Japan)] [Department of Electrical Engineering, Tohoku University, Sendai 980-8579 (Japan)

    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.

  18. Mechanical alignment of particles for use in fabricating superconducting and permanent magnetic materials

    DOE Patents [OSTI]

    Nellis, William J. (Berkeley, CA); Maple, M. Brian (Del Mar, CA)

    1992-01-01

    A method for mechanically aligning oriented superconducting or permanently magnetic materials for further processing into constructs. This pretreatment optimizes the final crystallographic orientation and, thus, properties in these constructs. Such materials as superconducting fibers, needles and platelets are utilized.

  19. Fabrication and Performance of Silicon-Embedded Permanent-Magnet Microgenerators

    E-Print Network [OSTI]

    Herrault, Florian

    This paper focuses on the design, fabrication, and characterization of silicon-packaged permanent-magnet (PM) microgenerators. The use of silicon packaging favors fine control on shape and dimensions in batch fabrication ...

  20. 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.

  1. Experimental verification for the design of a doubly-fed permanent magnetic generator

    E-Print Network [OSTI]

    Lu, Bin, Ph. D. Massachusetts Institute of Technology

    2007-01-01

    This is a continuous work on the project of a doubly-fed permanent magnet (DFPM) generator for wind turbines. The construction of a prototype machine was finally finished and experiments were conducted to verify the design ...

  2. ACTIVE SUSPENSION CONTROL WITH DIRECT-DRIVE TUBULAR LINEAR BRUSHLESS PERMANENT-MAGNET MOTOR 

    E-Print Network [OSTI]

    Lee, Seungho

    2010-01-16

    Recently, active suspension has been applied to many commercial automobiles. To develop the control algorithm for active suspension, a quarter-car test bed was built by using a direct-drive tubular linear brushless permanent-magnet motor (LBPMM...

  3. Structural optimisation of permanent magnet direct drive generators for 5MW wind turbines 

    E-Print Network [OSTI]

    Zavvos, Aristeidis

    2013-11-28

    This thesis focuses on permanent magnet "direct drive" electrical generators for wind turbines with large power output. A variety of such generator topologies is reviewed, tested and optimised in an attempt to increase ...

  4. Optimal Current Waveforms for Brushless Permanent Magnet Motors

    E-Print Network [OSTI]

    14, 2014 Abstract In this paper we give energy-optimal excitation current waveforms for a permanent work by including a general back-EMF waveform, voltage and cur- rent limits, an arbitrary phase winding. Another advantage of on-line optimization is the ability to adapt in real time to changes in the model

  5. Discharge Oscillations in a Permanent Magnet Cylindrical Hall-Effect Thruster

    E-Print Network [OSTI]

    circuit leaves very little room for magnetic pole pieces and heat shields. Propulsion Research EngineerDischarge Oscillations in a Permanent Magnet Cylindrical Hall-Effect Thruster IEPC-2009 and complexity as the voltage is increased, and are reduced in severity with increasing flow rate. The `breathing

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

    E-Print Network [OSTI]

    A Permanent-Magnet Microwave Ion Source for a Compact High-Yield Neutron Generator O. Waldmanna-yield compact neutron generator for active interrogation applications. The sealed tube generator will be capable with an optimized magnetic field. Keywords: Neutron generator, Microwave ion source, Active interroga- tion PACS: 29

  7. Evaluation of permanent magnets for high temperature operations 

    E-Print Network [OSTI]

    Van Hees, Elizabeth

    1985-01-01

    as 3H F = x. m. H- &x where x = the magnetic susceptibility, which is the magnetic moment, M, divided by H, the field strength. The partial differential, 3H/ax, is the field gradient of the magnet, and m is the mass of the sample. This equation... is to inves- tigate the relevent magnetic properties of commercially availalbe magnetic materials for prolonged use in a high temperature environment (200'C to 450'C). Such materials can be utilized in geothermal and petroleum well logging. A device...

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

    DOE Patents [OSTI]

    Alexander, James Pellegrino (Ballston Lake, NY); EL-Refaie, Ayman Mohamed Fawzi (Niskayuna, NY); Lokhandwalla, Murtuza (Clifton Park, NY); Shah, Manoj Ramprasad (Latham, NY); VanDam, Jeremy Daniel (West Coxsackie, NY)

    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.

  9. Study of Various Slanted Air-gap Structures of Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

    E-Print Network [OSTI]

    Tolbert, Leon M.

    magnet machine, synchronous motors, torque. I. NOMENCLATURE BFE brushless field excitation IPMSM interiorStudy of Various Slanted Air-gap Structures of Interior Permanent Magnet Synchronous Motor of the slanted air-gap structure of an interior permanent magnet synchronous motor with brushless field

  10. IEEE TRANSACTIONS ON MAGNETICS, VOL. 41, NO. 10, OCTOBER 2005 3823 Design of a Superhigh-Speed Cryogenic Permanent

    E-Print Network [OSTI]

    Wu, Thomas

    . In this paper, the design and simulation of a cryogenic PMSM with an output shaft power of 2000 W at 200 000 rpm magnet is centrally located inside the hollow shaft. The permanent magnet was inserted into the hollow shaft by heating the titanium shaft to 570 K and cooling the permanent magnet down to 77 K. B. Design

  11. 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.

  12. 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.

  13. 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.

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

    DOE Patents [OSTI]

    Sriram, Tillasthanam V. (Carmel, IN)

    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.

  15. Dynamic Motor Parameter Identification for High Speed Flux Weakening Operation of Brushless Permanent Magnet Synchronous Machines

    E-Print Network [OSTI]

    Szabados, Barna

    Permanent Magnet Synchronous Machines Abstract: An experimental investigation is conducted to determine the behaviour of brushless PM synchronous machine parameters in the high speed flux weakening operating range synchronous machines. Special computer assisted measuring techniques are employed using an experimental vector

  16. Control Realization for an Interior Permanent Magnet Synchronous Motor (IPMSM) in Automotive Drive Trains

    E-Print Network [OSTI]

    Noé, Reinhold

    Control Realization for an Interior Permanent Magnet Synchronous Motor (IPMSM) in Automotive Drive, the Maximal Torque Per Current (MTPC) method provides appropriate results. The requested torque is generated higher drive efficiency. The requested torque is generated with a minimum of total losses, which

  17. Permanent Magnet Motors for Energy Savings in Industrial Applications Copyright Material IEEE

    E-Print Network [OSTI]

    McCalley, James D.

    Permanent Magnet Motors for Energy Savings in Industrial Applications Copyright Material IEEE Paper industry. Over the past 30 years, there have been clear trends in motor utilization that demand higher energy efficiency and reduced Total Cost of Ownership (TCO). Induction motors have been able

  18. A Fault-Tolerant Multiphase Permanent Magnet Generator for Marine Current Turbine Applications

    E-Print Network [OSTI]

    Boyer, Edmond

    A Fault-Tolerant Multiphase Permanent Magnet Generator for Marine Current Turbine Applications on offshore wind turbine systems. Marine current turbines are characterized by a very difficult access feature. This paper deals with the use of a PM multiphase marine current turbine generator. With this kind

  19. Analysis of Slanted Air-gap Structure of Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

    E-Print Network [OSTI]

    Tolbert, Leon M.

    machine, synchronous motors, torque. I. NOMENCLATURE BFE brushless field excitation IPMSM interiorAnalysis of Slanted Air-gap Structure of Interior Permanent Magnet Synchronous Motor with Brushless permanent magnet synchronous motor (IPMSM) for application in a hybrid electric vehicle. This unique slanted

  20. Power-Factor and Torque Calculation with Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with

    E-Print Network [OSTI]

    Tolbert, Leon M.

    OF IPMSM Below is the well-known electromagnetic torque equation for all synchronous machines: dqqd iip Permanent Magnet Synchronous Motor with Brushless Field Excitation Seong Taek Lee1,2 , Timothy A. Burress1 permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include

  1. IEEE TRANSACTIONS ON MAGNETICS, VOL. 43, NO. 9, SEPTEMBER 2007 3623 Doubly Salient Permanent-Magnet Machine With Skewed Rotor

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    to control the motor. We validated the feasibility of these new design concepts by simulations, field SALIENT permanent-magnet machine (DSPM), a new kind of inverter-fed electrical traction motor first, such as high efficiency, high power density, and simple structure. Much progress has been made on the design

  2. 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.

  3. 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 the constant power speed range of the drive system and adjust the field for power factor and efficiency gains. Lower core losses at low torque regions, especially at high speeds, are attained by reducing the field excitation. Safety and reliability are increased by weakening the field when a winding short-circuit fault occurs, preventing damage to the motor. For a high-speed motor operating at 16,000-revolutions per minute (rpm), mechanical stress is a challenge. Bridges that link the rotor punching segments together must be thickened for mechanical integrity; consequently, increased rotor flux leakage significantly lowers motor performance. This barrier can be overcome by BFE to ensure sufficient rotor flux when needed.

  4. 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.

  5. 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.

  6. 734 IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 39, NO. 3, MAY/JUNE 2003 Modeling of Iron Losses of Permanent-Magnet

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    currents, hysteresis, iron losses, permanent magnets (PMs), permanent-magnet (PM) machines, synchronous Losses of Permanent-Magnet Synchronous Motors Chunting Mi, Member, IEEE, Gordon R. Slemon, Life Fellow and the reduction of stator loss from operation near unity power factor. In PM machines, iron losses form

  7. Analytical modeling of a new disc permanent magnet linear synchronous machine for electric vehicles

    SciTech Connect (OSTI)

    Liu, C.T.; Chen, J.W.; Su, K.S.

    1999-09-01

    This paper develops an analytical approach based on a qd0 reference frame model to analyze dynamic and steady state characteristics of disc permanent magnet linear synchronous machines (DPMLSMs). The established compact mathematical model can be more easily employed to analyze the system behavior and to design the controller. Superiority in operational electromagnetic characteristics of the proposed DPMLSM for electric vehicle (EV) applications is verified by both numerical simulations and experimental investigations.

  8. Optimal current control strategies for surface-mounted permanent-magnet synchronous machine drives

    SciTech Connect (OSTI)

    Chapman, P.L.; Sudhoff, S.D.; Whitcomb, C.A.

    1999-12-01

    The current waveforms for optimal excitation of surface-mounted permanent-magnet synchronous machines are set forth. Four different modes are considered, involving varying degrees of minimization of rms current and torque ripple. The optimized waveforms are markedly different than the traditional sinusoidal or rectangular excitation schemes. Inclusion of cogging torque and arbitrary degree of torque ripple minimization generalize this work over that of previous authors. An experimental drive and a detailed computer simulation verify the proposed control schemes.

  9. Minimizing Wheel Slip in Railway Locomotives with Coupled Permanent Magnet Synchronous Motors

    E-Print Network [OSTI]

    Shayak Bhattacharjee

    2015-01-17

    In this work I consider control strategies of permanent magnet synchronous motors in which the back-emf signal from the motor is used to achieve commutation of the six step driving circuit. I show that if the strategy is modified to connect multiple motors in a cyclic chain, then a collective synchronized state is favoured. The stability of this state can be exploited in the bogies of a railway locomotive to automatically terminate wheel slipping episodes.

  10. Abstract --For high-speed machines applications, eddy-current losses in the interior permanent magnet of synchronous

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Abstract -- For high-speed machines applications, eddy- current losses in the interior permanent carries out a prediction of eddy current losses in PM where the skin effect is considered. A complete by analytical method. Index Terms-- High speed, Permanent magnet machines, Eddy-currents, power losses, skin

  11. 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.

  12. JOURNAL DE PHYSIQUE Colloque C5, supplment au n 5, Tome 40, Mai 1979, page C5-273 The physics and the technology of rare earth permanent magnets

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    to forecast the type of substitution to employ on the rare earth or transition metals, as a means and the technology of rare earth permanent magnets J. P. Haberer and H. Lemaire Aimants UGIMAG S.A., France Résumé rare earth base alloys have magnetic properties which substantially exceed the values obtained before

  13. 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.

  14. 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

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

    SciTech Connect (OSTI)

    McIntyre, Timothy J [ORNL

    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 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.

  16. 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.

  17. Modular axial-flux permanent-magnet motor for ship propulsion drives

    SciTech Connect (OSTI)

    Caricchi, F.; Crescimbini, F.; Honorati, O.

    1999-09-01

    Original features such as compactness and lightness make slotless axial-flux permanent-magnet machines (AFPMs) eligible for application in large power motor drives devoted to the direct drive of ship propellers. This paper discusses characteristics of AFPMs designed for application in marine propulsion, and machine performances such as efficiency, weight and torque density are evaluated for a comparison with those of conventional synchronous machines. A newly-conceived modular arrangement of the machine stator winding is proposed and experimental results taken from a small-size machine prototype are finally shown.

  18. 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.

  19. 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 ?-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 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

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

    SciTech Connect (OSTI)

    Hadjipanayis, George C. [University of Delaware] [University of Delaware; McCallum, William R. [Ames Laboratory] [Ames Laboratory; Sellmyer, David J. [University of Nebraska, Lincoln] [University of Nebraska, Lincoln; Harris, Vincent [Northeastern University] [Northeastern University; Carpenter, Everett E. [Virginia Commonwealth University] [Virginia Commonwealth University; Liu, Jinfang [Electron Energy Corporation] [Electron Energy Corporation

    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.

  1. Calculation of cogging force in a novel slotted linear tubular brushless permanent magnet motor

    SciTech Connect (OSTI)

    Zhu, Z.Q.; Hor, P.J.; Howe, D. [Univ. of Sheffield (United Kingdom). Dept. of Electronic and Electrical Engineering] [Univ. of Sheffield (United Kingdom). Dept. of Electronic and Electrical Engineering; Rees-Jones, J. [Unilever Research Port Sunlight Lab., Bebington (United Kingdom)] [Unilever Research Port Sunlight Lab., Bebington (United Kingdom)

    1997-09-01

    There is an increasing requirement for controlled linear motion over short and long strokes, in the factory automation and packaging industries, for example. Linear brushless PM motors could offer significant advantages over conventional actuation technologies, such as motor driven cams and linkages and pneumatic rams--in terms of efficiency, operating bandwidth, speed and thrust control, stroke and positional accuracy, and indeed over other linear motor technologies, such as induction motors. Here, a finite element/analytical based technique for the prediction of cogging force in a novel topology of slotted linear brushless permanent magnet motor has been developed and validated. The various force components, which influence cogging are pre-calculated by the finite element analysis of some basic magnetic structures, facilitate the analytical synthesis of the resultant cogging force. The technique can be used to aid design for the minimization of cogging.

  2. 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 Teubner–Stray 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.

  3. 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 today’s 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.

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

    SciTech Connect (OSTI)

    None

    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.

  5. Adaptive fuzzy dynamic surface control for the chaotic permanent magnet synchronous motor using Nussbaum gain

    SciTech Connect (OSTI)

    Luo, Shaohua [School of Automation, Chongqing University, Chongqing 400044, China and College of Mechanical Engineering, Hunan University of Arts and Science, Hunan 415000 (China)

    2014-09-01

    This paper is concerned with the problem of adaptive fuzzy dynamic surface control (DSC) for the permanent magnet synchronous motor (PMSM) system with chaotic behavior, disturbance and unknown control gain and parameters. Nussbaum gain is adopted to cope with the situation that the control gain is unknown. And the unknown items can be estimated by fuzzy logic system. The proposed controller guarantees that all the signals in the closed-loop system are bounded and the system output eventually converges to a small neighborhood of the desired reference signal. Finally, the numerical simulations indicate that the proposed scheme can suppress the chaos of PMSM and show the effectiveness and robustness of the proposed method.

  6. Design of low-power permanent-magnet synchronous motor for use in high-density heat pump

    E-Print Network [OSTI]

    Jenicek, David P. (David Pierre)

    2011-01-01

    An analytical model for the functionality of a permanent-magnet synchronous motor is developed. Taking as input a specific geometry, it predicts steady-state losses of a design at an average rate of 0.85 seconds per analysis, ...

  7. Design and Empirical Identification of a Lumped Parameter Thermal Network for Permanent Magnet Synchronous Motors with Physically

    E-Print Network [OSTI]

    Noé, Reinhold

    Synchronous Motors with Physically Motivated Constraints Oliver Wallscheid, Student Member, IEEE, Joachim B¨ocker, Senior Member, IEEE Abstract--Monitoring critical temperatures in permanent magnet synchronous motors (PMSM) is essential to prevent device failures or excessive motor life time reduction due to thermal

  8. IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 2095 Permanent Magnet Helicon Source for Ion Propulsion

    E-Print Network [OSTI]

    Chen, Francis F.

    IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 2095 Permanent Magnet Helicon Source for Ion Propulsion Francis F. Chen, Life Fellow, IEEE Abstract--Helicon sources have been proposed by at least two groups for generating ions for space propulsion: the Helicon Dou- ble Layer Thruster (HDLT

  9. 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. (San Carlos, CA); Rottmayer, Robert Earl (Fremont, CA); Carey, Matthew J. (San Jose, CA)

    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.

  10. Studies on the effect of the axial magnetic field on the x-ray bremsstrahlung in a 2.45 GHz permanent magnet microwave ion source

    SciTech Connect (OSTI)

    Kumar, Narender; Rodrigues, G., E-mail: gerosro@gmail.com; Lakshmy, P. S.; Mathur, Y.; Ahuja, R.; Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi (India)] [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi (India); Baskaran, R. [Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India)] [Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India)

    2014-02-15

    A compact microwave ion source has been designed and developed for operation at a frequency of 2.45 GHz. The axial magnetic field is based on two permanent magnet rings, operating in the “off-resonance” mode and is tunable by moving the permanent magnets. In order to understand the electron energy distribution function, x-ray bremsstrahlung has been measured in the axial direction. Simulation studies on the x-ray bremsstrahlung have been carried out to compare with the experimental results. The effect of the axial magnetic field with respect to the microwave launching position and the position of the extraction electrode on the x-ray bremsstrahlung have been studied.

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

    SciTech Connect (OSTI)

    Su, Gui-Jia [ORNL; Tang, Lixin [ORNL; Huang, Xianghui [GE Global Research

    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.

  12. 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.

  13. 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.}

  14. 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 regardless of speed for relative speeds, n = {omega}/{omega}{sub base} {ge} 2. Performance was also examined with efficiency measurements during the 30-kW PM motor test. Material requirements were examined with finite-element analyses (FEA) to determine the speed and location where yield starts and the corresponding deformations and stresses.

  15. 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.

  16. 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 developed in future work. This report documents the results of this preliminary investigation.

  17. 50 IEEE TRANSACTIONS ON MAGNETICS, VOL. 40, NO. 1, JANUARY 2004 Analytical Method for Predicting the Air-Gap Flux of

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    the Air-Gap Flux of Interior-Type Permanent-Magnet Machines Chunting Mi, Senior Member, IEEE, Mariano method to calcu- late the air-gap magnetic flux of interior-type permanent-magnet (IPM) machines taking INTERIOR-TYPE permanent-magnet (IPM) motors are used in a wide range of industrial applications due

  18. Spectra of In-like Tungsten, $W^{25+}$, from the Shanghai permanent magnet electron beam ion trap

    E-Print Network [OSTI]

    Li, W; Shi, Z; Fei, Z; R,; Zhao,; Brage, T; Huldt, S; Hutton, R; Zou, Y

    2015-01-01

    Three visible lines of M1 transitions from In-like W were recorded using the Shanghai permanent magnet electron beam ion trap. The experimental wavelengths were measured as 493.84 $\\pm$ 0.15, 226.97 $\\pm$ 0.13 and 587.63 $\\pm$ 0.23 nm (vacuum wavelengths). These results are in good agreement with theoretical predictions obtained using large-scale Relativistic Many-Body Perturbation Theory, in the form of the Flexible Atomic Code, and some explorations with the Muliconfiguration Dirac-Hartree-Fock code GRASP2K.

  19. 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.

  20. 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.

  1. Power-Factor Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

    SciTech Connect (OSTI)

    Lee, Seong T [ORNL; Burress, Timothy A [ORNL; Hsu, John S [ORNL

    2009-01-01

    This paper introduces a new method for calculating the power factor with consideration of the cross saturation between the direct-axis (d-axis) and the quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross-saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux at high speed, which was developed for the traction motor of a hybrid electric vehicle.

  2. On-the-fly machine-learning for high-throughput experiments: search for rare-earth-free permanent magnets

    SciTech Connect (OSTI)

    Kusne, AG; Gao, TR; Mehta, A; Ke, LQ; Nguyen, MC; Ho, KM; Antropov, V; Wang, CZ; Kramer, MJ; Long, C; Takeuchi, I

    2014-09-15

    Advanced materials characterization techniques with ever-growing data acquisition speed and storage capabilities represent a challenge in modern materials science, and new procedures to quickly assess and analyze the data are needed. Machine learning approaches are effective in reducing the complexity of data and rapidly homing in on the underlying trend in multi-dimensional data. Here, we show that by employing an algorithm called the mean shift theory to a large amount of diffraction data in high-throughput experimentation, one can streamline the process of delineating the structural evolution across compositional variations mapped on combinatorial libraries with minimal computational cost. Data collected at a synchrotron beamline are analyzed on the fly, and by integrating experimental data with the inorganic crystal structure database (ICSD), we can substantially enhance the accuracy in classifying the structural phases across ternary phase spaces. We have used this approach to identify a novel magnetic phase with enhanced magnetic anisotropy which is a candidate for rare-earth free permanent magnet.

  3. 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.

  4. Interaction between an electric charge and a magnetic dipole of any kind (permanent, para- or dia- magnetic or superconducting)

    E-Print Network [OSTI]

    Coïsson, R

    2015-01-01

    The interaction between point charge and magnetic dipole is usually considered only for the case of a rigid ferromagnetic dipole (constant-current): here the analysis of force, momentum and energy (including the energy provided by the internal current generator) is generalised to any magnetic dipole behaviour: rigid, paramagnetic, diamagnetic or superconducting (perfectly diamagnetic).

  5. Noise reduction control strategy of a permanent magnet synchronous machine for vehicle applications 

    E-Print Network [OSTI]

    Doolittle, Randy Gene

    2009-05-15

    that was not available: 1. V S (secant voltage) or a phase voltage to give a value to the BackEMF (E) 2. L A , L B , L C (phase inductances), L S (secant inductance), or L D and L Q 3. M D ? (magnet flux linkage) or B G (air gap flux density) The thesis... T EM,rated d-q rated Torque 309Nm V S,rated Secant Voltage I S,rated,rms Secant Rated RMS Current 300A P ,rated Rated Machine Power P ,max Maximum Machine Power 64.5kW ? ,max Top Speed E Back EMF @ Top Speed 400V (assumed could be 600V...

  6. 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.

  7. 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)

  8. 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.

  9. 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.

  10. Toroidal Magnetic Fields in Type II Superconducting Neutron Stars

    E-Print Network [OSTI]

    Taner Akgun; Ira Wasserman

    2007-11-01

    We determine constraints on the form of axisymmetric toroidal magnetic fields dictated by hydrostatic balance in a type II superconducting neutron star with a barotropic equation of state. Using Lagrangian perturbation theory, we find the quadrupolar distortions due to such fields for various models of neutron stars with type II superconducting and normal regions. We find that the star becomes prolate and can be sufficiently distorted to display precession with a period of the order of years. We also study the stability of such fields using an energy principle, which allows us to extend the stability criteria established by R. J. Tayler for normal conductors to more general media with magnetic free energy that depends on density and magnetic induction, such as type II superconductors. We also derive the growth rate and instability conditions for a specific instability of type II superconductors, first discussed by P. Muzikar, C. J. Pethick and P. H. Roberts, using a local analysis based on perturbations around a uniform background.

  11. 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 speed depends solely on machine parameters and is virtually independent of the load level and the direct current (dc) supply voltage. Thus, the motor current is virtually the same at no load as at full load resulting in poor efficiency at less than full load conditions. While an inductance higher than the value cited above is warranted, it still does not ensure that the motor current is proportional to load; consequently, the problem of low efficiency at high speed and partial load is not resolved but is only mitigated. A common definition of 'base speed' is the speed at which the voltage applied to the motor armature is equal to the magnitude of the back-emf. The results in this study indicate that the dc supply voltage should be adequate to drive rated current into the motor winding at the specified base speed. At a minimum this requires sufficient voltage to overcome not only the back-emf but also the voltage drop across the internal impedance of the machine. For a high inductance PMSM, the internal impedance at base speed can be considerable and substantial additional voltage is required to overcome the internal voltage drop. It is further shown that even more voltage than the minimum required for injecting rated current at base speed can be beneficial by allowing the required power to be developed at lower current, which reduces losses in the motor and inverter components. Further, it is shown that the current is minimized at a unique speed; consequently, there may be room for optimization if the drive spends a substantial amount of its operating life at a certain speed (for example 60 mph). In this study, fundamental frequency phasor models are developed for a synchronous PMSM and the control systems that drive them is CPA. The models were compared with detailed simulations to show their validity. The result was used to design a traction drive control system with optimized efficiency to drive the fractional-slot motor with concentrated windings. The goal is to meet or exceed the FreedomCAR inverter cost and performance targets.

  12. High-Performance Control of Two Three-Phase Permanent-Magnet Synchronous Machines in an Integrated Drive for Automotive Applications

    SciTech Connect (OSTI)

    Tang, Lixin [ORNL; Su, Gui-Jia [ORNL

    2008-01-01

    The closed-loop control of an integrated dual AC drive system is presented to control two three-phase permanent-magnet motors. A five-leg inverter is employed in the drive system; three of the inverter legs are for a main traction motor, but only two are needed for a three-phase auxiliary motor by utilizing the neutral point of the traction motor. An integrated drive with reduced component count is therefore achieved by eliminating one inverter leg and its gate drivers. A modified current control scheme based on the rotor flux orientation principle is presented. Simulation and experimental results are included to verify the independent control capability of the integrated drive.

  13. Calculation of synchronous reactances of small permanent-magnet alternating-current motors: Comparison of analytical approach and finite element method with measurements

    SciTech Connect (OSTI)

    Gieras, J.F.; Wing, M. [Univ. of Cape Town, Rondebosch (South Africa). Dept. of Electrical Engineering] [Univ. of Cape Town, Rondebosch (South Africa). Dept. of Electrical Engineering; Santini, E. [Univ. of Rome (Italy). Dept. of Electrical Engineering] [Univ. of Rome (Italy). Dept. of Electrical Engineering

    1998-09-01

    The synchronous reactances of permanent magnet (PM) motors have been determined using: (1) analytical method, i.e., form factors of the stator field (armature reaction factors), (2) finite element method (FEM), and (3) experimental tests on a special machine set. The analytical method is widely used in calculations of synchronous reactances of salient pole synchronous machines with electromagnetic excitation. Rotors of PM synchronous machines have more complicated structures, hence it is more difficult to predict accurately the magnetic field distribution in their airgaps in order to find the form factors of the stator field. Numerical methods of field analysis can easily solve this problem. The FEM can predict both the synchronous and mutual (armature reaction) reactances in the d and q axes. The leakage reactance can then be evaluated as a difference between synchronous and mutual reactances. As an example, a small, three-phase, four-pole motor with SmCo surface mounted PM`s (three parallel magnets per pole), and mild-steel pole shoes has been investigated. Such a complicated rotor structure has been intentionally designed in order to be able to compare the advantages and disadvantages of the analytical method and the FEM. In the FEM, the reactances have been calculated using both the flux linkage and current/energy perturbation method. Synchronous reactances as functions of the stator current and load angle obtained analytically from the FEM modeling and from measurements have been compared.

  14. Type II superconductivity and magnetic flux transport in neutrons stars

    E-Print Network [OSTI]

    P. B. Jones

    2005-10-13

    The transition to a type II proton superconductor which is believed to occur in a cooling neutron star is accompanied by changes in the equation of hydrostatic equilibrium and by the formation of proton vortices with quantized magnetic flux. Analysis of the electron Boltzmann equation for this system and of the proton supercurrent distribution formed at the transition leads to the derivation of a simple expression for the transport velocity of magnetic flux in the liquid interior of a neutron star. This shows that flux moves easily as a consequence of the interaction between neutron and proton superfluid vortices during intervals of spin-down or spin-up in binary systems. The differences between the present analysis and those of previous workers are reviewed and an error in the paper of Jones (1991) is corrected.

  15. 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.

  16. Power-Factor and Torque Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

    SciTech Connect (OSTI)

    Lee, Seong T [ORNL; Burress, Timothy A [ORNL; Tolbert, Leon M [ORNL

    2009-01-01

    This paper introduces a new method for calculating the power factor and output torque by considering the cross saturation between direct-axis (d-axis) and quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux at high speed, which was developed for the traction motor of a hybrid electric vehicle. The conventional two-axis IPMSM model was modified to include the cross-saturation effect by adding the cross-coupled inductance terms Ldq and Lqd. By the advantage of the excited structure of the experimental IPMSM, the analyzing works were performed under two conditions, the highest and lowest excited conditions. Therefore, it is possible to investigate the cross-saturation effect when a machine has higher magnetic flux from its rotor. The following is a summary of conclusions that may be drawn from this work: (1) Considering cross saturation of an IPMSM offers more accurate expected values of motor parameters in output torque calculation, especially when negative d-axis current is high; (2) A less saturated synchronous machine could be more affected by the cross-coupled saturation effect; (3) Both cross-coupled inductances, L{sub qd} and L{sub dq}, are mainly governed by d-axis current rather than q-axis current; (4) The modified torque equation, can be used for the dynamic model of an IPMSM for developing a better control model or control strategy; and (5) It is possible that the brushless field excitation structure has a common magnetic flux path on both d- and q-axis, and as a result, the reluctance torque of the machine could be reduced.

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

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

    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...

  18. Enhanced production of electron cyclotron resonance plasma by exciting selective microwave mode on a large-bore electron cyclotron resonance ion source with permanent magnet

    SciTech Connect (OSTI)

    Kimura, Daiju, E-mail: kimura@nf.eie.eng.osaka-u.ac.jp; Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Imai, Youta; Kumakura, Sho; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)] [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

    2014-02-15

    We are constructing a tandem type ECRIS. The first stage is large-bore with cylindrically comb-shaped magnet. We optimize the ion beam current and ion saturation current by a mobile plate tuner. They change by the position of the plate tuner for 2.45 GHz, 11–13 GHz, and multi-frequencies. The peak positions of them are close to the position where the microwave mode forms standing wave between the plate tuner and the extractor. The absorbed powers are estimated for each mode. We show a new guiding principle, which the number of efficient microwave mode should be selected to fit to that of multipole of the comb-shaped magnets. We obtained the excitation of the selective modes using new mobile plate tuner to enhance ECR efficiency.

  19. 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 light load and higher speed. This current reduction, which is the salient feature of DMIC, may be significant when operating duty cycles have low loads at high frequencies. Reduced copper losses make operation more efficient thereby reducing operating costs. In the Deere applications selected for this study, the operating benefit was overshadowed by the motor's rotational losses. Rotational losses of Deere 1 and Deere 2 dominate the overall drive efficiency so that their reduction has the greatest potential to improve performance. A good follow-up project would be to explore cost erective ways to reduce the rotational losses buy 66%.

  20. The Lorentz transformations of the vectors E, B, P, M and the external electric fields from a stationary superconducting wire with a steady current and from a stationary permanent magnet

    E-Print Network [OSTI]

    Tomislav Ivezic

    2012-11-02

    In the first part of this paper we review the fundamental difference between the usual transformations of the three-dimensional (3D) vectors of the electric field $\\mathbf{E}$, the magnetic field $\\mathbf{B}$, the polarization $\\mathbf{P}$, the magnetization $\\mathbf{M}$ and the Lorentz transformations of the 4D geometric quantities, vectors E, B, P, M, with many additional explanations and several new results. In the second part, we have discussed the existence of the electric field vector E outside a stationary superconducting wire with a steady current and also different experiments for the detection of such electric fields. Furthermore, a fundamental prediction of the existence of the external electric field vector E from a stationary permanent magnet is considered. These electric fields are used for the resolution of the "charge-magnet paradox" with 4D geometric quantities for a qualitative explanation of the Aharonov-Bohm effect in terms of fields and not, as usual, in terms of the vector potential and for a qualitative explanation that the particle interference is not a test of a Lorentz-violating model of electrodynamics according to which a magnetic solenoid generates not only a static magnetic field but also a static electric field.

  1. The evolution of surface magnetic fields in young solar-type stars

    E-Print Network [OSTI]

    Folsom, C P; Bouvier, J; Morin, J; Lèbre, A

    2015-01-01

    Surface rotation rates of young solar-type stars display drastic changes at the end of the pre-main sequence through the early main sequence. This may trigger corresponding changes in the magnetic dynamos operating in these stars, which ought to be observable in their surface magnetic fields. We present here the first results of an observational effort aimed at characterizing the evolution of stellar magnetic fields through this critical phase. We observed stars from open clusters and associations, which range from 20 to 600 Myr, and used Zeeman Doppler Imaging to characterize their complex magnetic fields. We find a clear trend towards weaker magnetic fields for older ages, as well as a tight correlation between magnetic field strength and Rossby number over this age range. Comparing to results for younger T Tauri stars, we observe a very significant change in magnetic strength and geometry, as the radiative core develops during the late pre-main sequence.

  2. AC losses in type-II superconductors induced by nonuniform fluctuations of external magnetic field

    E-Print Network [OSTI]

    as the economic gains of implementation of type-II superconductors in power transmission lines, current leads amplitude. The results can be used to estimate the AC losses in flywheels, electric motors, magnetic shields

  3. Anomalous delta-type electric and magnetic two-nucleon interactions

    E-Print Network [OSTI]

    Nicolae Bogdan Mandache

    2009-04-07

    Anomalous delta-type interactions, of both electric and magnetic nature, are introduced between the overlapping peripheral structures of the nucleons, which may explain the spin-triplet deuteron state and the absence of other nucleon-nucleon bound states.

  4. High Temperature, Permanent Magnet Biased Magnetic Bearings 

    E-Print Network [OSTI]

    Gandhi, Varun R.

    2010-07-14

    performance, high speed and high temperature applications like space vehicles, jet engines and deep sea equipment. The bearing system had a target design to carry a load equal to 500 lb-f (2225N). Another objective was to design and build a test rig fixture...

  5. Magnetic levitation on a type-I superconductor as a practical demonstration experiment for students

    E-Print Network [OSTI]

    Osorio, M R; Suderow, H

    2012-01-01

    We describe and discuss an experimental set-up which allows undergraduate and graduate students to view and study magnetic levitation on a type-I superconductor. The demonstration can be repeated many times using one readily available 25 liter liquid helium dewar. We study the equilibrium position of a magnet that levitates over a lead bowl immersed in a liquid hand-held helium cryostat. We combine the measurement of the position of the magnet with simple analytical calculations. This provides a vivid visualization of magnetic levitation from the balance between pure flux expulsion and gravitation. The experiment contrasts and illustrates the case of magnetic levitation with high temperature type-II superconductors using liquid nitrogen, where levitation results from partial flux expulsion and vortex physics.

  6. Condensate Nuclei and Magnetic Polarity Reversals in the Sun and Solar-type Stars

    E-Print Network [OSTI]

    Babur M. Mirza

    2015-05-28

    Magnetic field generation in the Sun and solar-type stars is modeled here based on the formation of magnetically polarized condensates (B. M. Mirza, Mod. Phys. Lett. B 28 (2014) 1450148) under the high density and pressure conditions. The correct orders of magnitude for the time period and the energy loss in a solar cycle are deduced, as well as the enhancement in the energy emission observed during solar cycles. It is shown that this feedback magnetic field along with differential rotation is sufficient to generate the toroidal magnetic field in the solar exterior. The model is useful in determining magnetic polarity reversals, energy generation, and reversal times, in solar-type stars.

  7. Creating the Permanent Prisoner

    E-Print Network [OSTI]

    Dolovich, Sharon

    2012-01-01

    Facing the Challenges of Prisoner Reentry (Washington, DC:Press, 2005). Creating the Permanent Prisoner | 137C. West, Data Brief: Prisoners at Yearend 2009—Advance

  8. Solar-type Magnetic Reconnection Model for Magnetar Giant Flare

    E-Print Network [OSTI]

    Youhei Masada; Shigehiro Nagataki; Kazunari Shibata; Toshio Terasawa

    2010-05-24

    We present a theoretical model describing magnetar giant flares on the basis of solar flare/coronal mass ejection theory. In our model, a preflare activity plays a crucial role in driving evaporating flows and supplying baryonic matters into the magnetosphere. The loaded baryonic matter, that is called "prominence", is then gradually uplifted via crustal cracking with maintaining a quasi-force-free equilibrium of the magnetosphere. Finally the prominence is erupted by the magnetic pressure force due to the loss of equilibrium triggered by the explosive magnetic reconnection. The giant flare should be induced as a final outcome of the prominence eruption accompanied by large-scale field reconfigurations. An essential difference between solar and magnetar flares is the control process of their evolutionary dynamics. The flaring activity on magnetars is mainly controlled by the radiative process unlike the solar flare governed by the electron conduction. It is highly suggestive that our model is accountable for the physical properties of the extraordinary giant flare observed on 2004 December 27 from SGR1806-20, including the source of baryonic matters loaded in the expanding ejecta observed after the giant burst.

  9. Study of Catcher Bearings for High Temperature Magnetic Bearing Application 

    E-Print Network [OSTI]

    Narayanaswamy, Ashwanth

    2011-08-08

    temperature permanent magnet based magnetic bearings. The magnetic bearings are made of high temperature resistant permanent magnets (up to 1000 degrees F). A test rig has been developed to test these magnetic bearings. The test rig mainly consists of two...

  10. Gating of Permanent Molds for ALuminum Casting

    SciTech Connect (OSTI)

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang

    2004-03-30

    This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

  11. Sub-natural $N$-type Resonance in Cesium Atomic Vapor: splitting in magnetic fields

    E-Print Network [OSTI]

    Slavov, D; Sarkisyan, D; Mirzoyan, R; Krasteva, A; Wilson-Gordon, A D; Cartaleva, S

    2013-01-01

    The sub-natural-width $N$-type resonance in {\\Lambda}-system, on the $D_2$ line of Cs atoms is studied for the first time in the presence of a buffer gas (neon) and the radiations of two continuous narrow band diode lasers. $L$ = 1 cm long cell is used to investigate $N$-type process. The $N$-type resonance in a magnetic field for $^{133}$Cs atoms is shown to split into seven or eight components, depending on the magnetic field and laser radiation directions. The results obtained indicate that levels $F_g$ = 3, 4 are initial and final in the N resonance formation. The experimental results with magnetic field agree well with the theoretical curves.

  12. Pinch-type instability experiments in magnetic Taylor-Couette flows

    E-Print Network [OSTI]

    Pinch-type instability experiments in magnetic Taylor-Couette flows G. R¨udiger1 and D.A. Shalybkov.F. Ioffe Institute of Physics and Technology, 194021 St. Petersburg, Russia E-mail: gruediger enough Hartmann numbers the toroidal field is always (pinch-)unstable independent of any details

  13. THE DESIGN AND FABRICATION OF A LARGE MAGNETIC CUSP TYPE OF PLASMA GENERATOR FOR THE PRODUCTION OF NEGATIVE IONS

    E-Print Network [OSTI]

    Biagi, L.A.

    2010-01-01

    MAGNETIC CUSP TYPE OF PLASMA GENERATOR FOR THE PRODUCTION OFMAGNETIC CUSP TYPE OF PLASMA GENERATOR F R THE PRODUCTION OFa t i o n of the plasma generator to be useo on t h i s t e

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O O D SFederal8823 Revision 02August 1, LowerMicroclimatesAre

  15. 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.

  16. U.S. Rare Earth Magnet Patents Table © 6-2-2015 page 1

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

    of permanent magnetic motors with broader and flexible in material selection space and cost selection space What is claimed is: 1. A composite permanent magnetic material,...

  17. Fast and slow magnetic deflagration fronts in Type I X-ray bursts

    E-Print Network [OSTI]

    Cavecchi, Yuri; Watts, Anna L; Braithwaite, Jonathan

    2015-01-01

    Type I X-ray bursts are produced by thermonuclear runaways that develop on accreting neutron stars. Once one location ignites, the flame propagates across the surface of the star. Flame propagation is fundamental in order to understand burst properties like rise time and burst oscillations. Previous work quantified the effects of rotation on the front, showing that the flame propagates as a deflagration and that the front strongly resembles a hurricane. However the effect of magnetic fields was not investigated, despite the fact that magnetic fields strong enough to have an effect on the propagating flame are expected to be present on many bursters. In this paper we show how the coupling between fluid layers introduced by an initially vertical magnetic field plays a decisive role in determining the character of the fronts that are responsible for the Type I bursts. In particular, on a star spinning at 450 Hz (typical among the bursters) we test seed magnetic fields of $10^{7} - 10^{10}$ G and find that for th...

  18. Type I and Two-Gap Superconductivity in Neutron Star Magnetism

    E-Print Network [OSTI]

    P B Jones

    2006-08-18

    Neutron-star inner cores with several charged baryonic components are likely to be analogues of the two-gap superconductor which is of current interest in condensed-matter physics. Consequently, type I superconductivity is less probable than type II but may nevertheless be present in some intervals of matter density. The intermediate state structure formed at finite magnetic flux densities after the superconducting transitions is subject to buoyancy, frictional and neutron-vortex interaction forces. These are estimated and it is shown that the most important frictional force is that produced by the stable stratification of neutron-star matter, the irreversible process being diffusion in the normal, finite magnetic-flux density, parts of the structure. The length-scale of the structure, in directions perpendicular to the local magnetic field is of crucial importance. For small scales, the flux comoves with the neutron vortices, as do the proton vortices of a type II superconductor. But for much larger length-scales, flux movement tends to that expected for normal charged Fermi systems.

  19. Advanced Penning-type ion source development and passive beam focusing techniques for an associated particle imaging neutron generator

    E-Print Network [OSTI]

    Sy, Amy

    2013-01-01

    Compact Permanent Magnet Microwave-Driven Neutron Generator.generator. The planned replacement of this electromagnet with a permanent-magnet

  20. 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.

  1. Magnetic levitation system for moving objects - Energy Innovation...

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

    Abstract: Repelling magnetic forces are produced by the interaction of a flux-concentrated magnetic field (produced by permanent magnets or electromagnets) with an...

  2. Temporary and Permanent Buyout Prices in Online Auctions

    E-Print Network [OSTI]

    Gupta, Shobhit

    Increasingly used in online auctions, buyout prices allow bidders to instantly purchase the item listed. We distinguish two types: a temporary buyout option disappears if a bid above the reserve price is made; a permanent ...

  3. IEEE TRANSACTIONS ON ENERGY CONVERSION, VOL. 20, NO. 1, MARCH 2005 121 Minimization of Iron Losses of Permanent

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    magnet machines, synchronous machines. I. INTRODUCTION ELECTRIC motor-driven equipment utilizes of Permanent Magnet Synchronous Machines Chunting Chris Mi, Senior Member, IEEE, Gordon R. Slemon, Life Fellow, IEEE, and Richard Bonert, Member, IEEE Abstract--In permanent magnet (PM) synchronous machines, iron

  4. Permanent magnet focused X-band photoinjector

    DOE Patents [OSTI]

    Yu, David U. L. (Rancho Palos Verdes, CA); Rosenzweig, James (Los Angeles, CA)

    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.

  5. Nitrogen enrichment, boron depletion and magnetic fields in slowly-rotating B-type dwarfs

    E-Print Network [OSTI]

    T. Morel; S. Hubrig; M. Briquet

    2008-01-29

    Evolutionary models for massive stars, accounting for rotational mixing effects, do not predict any core-processed material at the surface of B dwarfs with low rotational velocities. Contrary to theoretical expectations, we present a detailed and fully-homogeneous, NLTE abundance analysis of 20 early B-type dwarfs and (sub)giants that reveals the existence of a population of nitrogen-rich and boron-depleted, yet intrinsically slowly-rotating objects. The low-rotation rate of several of these stars is firmly established, either from the occurrence of phase-locked UV wind line-profile variations, which can be ascribed to rotational modulation, or from theoretical modelling in the pulsating variables. The observational data presently available suggest a higher incidence of chemical peculiarities in stars with a (weak) detected magnetic field. This opens the possibility that magnetic phenomena are important in altering the photospheric abundances of early B dwarfs, even for surface field strengths at the one hundred Gauss level. However, further spectropolarimetric observations are needed to assess the validity of this hypothesis.

  6. Nitrogen enrichment, boron depletion and magnetic fields in slowly-rotating B-type dwarfs

    E-Print Network [OSTI]

    Morel, T; Briquet, M

    2008-01-01

    Evolutionary models for massive stars, accounting for rotational mixing effects, do not predict any core-processed material at the surface of B dwarfs with low rotational velocities. Contrary to theoretical expectations, we present a detailed and fully-homogeneous, NLTE abundance analysis of 20 early B-type dwarfs and (sub)giants that reveals the existence of a population of nitrogen-rich and boron-depleted, yet intrinsically slowly-rotating objects. The low-rotation rate of several of these stars is firmly established, either from the occurrence of phase-locked UV wind line-profile variations, which can be ascribed to rotational modulation, or from theoretical modelling in the pulsating variables. The observational data presently available suggest a higher incidence of chemical peculiarities in stars with a (weak) detected magnetic field. This opens the possibility that magnetic phenomena are important in altering the photospheric abundances of early B dwarfs, even for surface field strengths at the one hund...

  7. An efficient gigawatt level X-band Cerenkov type oscillator without guiding magnetic field

    SciTech Connect (OSTI)

    Guo, Liming; Shu, Ting; Li, Zhiqiang; Zhang, Hua; Ju, Jinchuan [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2014-07-15

    This paper presents a novel modification of gigawatt level X-band Cerenkov type high power microwave oscillator without guiding magnetic field. A confining cathode is put forward to suppress the radial dispersion of the annular relativistic electron beam and accordingly improve its axial transportation to ensure further beam-wave interaction. An overmoded nonuniform slow wave structure is adopted in order to increase the power capacity of the oscillator and the efficiency of beam-wave interaction. A tapered collector is used to collect the beam, increase the Q-factor, and extract the microwave favorably. The simulation results indicate that a microwave is generated by the proposed oscillator with output power of 1.9?GW and frequency of 9.02?GHz, when the diode voltage and beam current are 620?kV and 9?kA, respectively. The corresponding power conversion efficiency is 34%.

  8. A Compact Disk Type Plasma Propulsion System with Modulated Magnetic Field for Nanoscale Space Vehicles

    SciTech Connect (OSTI)

    Fukuda, Takeshi; Ueda, Satoshi; Ohnishi, Yukihiro; Inomoto, Michiaki [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, 565-0871 Osaka (Japan)

    2008-12-31

    A compact 5 mm disk type plasma thruster simply composed of only a set of antenna windings and bias field coil which produces significant thrust of 0.74 mN with rotating magnetic field has been proposed and successfully developed for future applications to low altitude nanosatellites. The key technology issue is that the rotating speed is set above the ion plasma frequency but far below the electron plasma frequency, in order to produce the electron drag current and axial electric field as a consequence of the interaction with the bias field. The formation of axial electric field was confirmed and the produced plasma density was >6x10{sup 18} m{sup -3}, whereas the power consumption is 500 W in the inductively coupled mode of operation. The anticipated thrust density and specific thrust could potentially be extended to 7.64 Nm{sup -2} and 850 s, respectively, which is comparable to conventional Hall effect thrusters.

  9. Superconducting Magnet Division

    E-Print Network [OSTI]

    Gupta, Ramesh

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

  10. 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?Å) and Fe ion (0.645?Å). 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.

  11. X-ray emission from the giant magnetosphere of the magnetic O-type star NGC 1624-2

    E-Print Network [OSTI]

    Petit, V; Wade, G A; Nazé, Y; Owocki, S P; Sundqvist, J O; ud-Doula, A; Fullerton, A; Leutenegger, M; Gagné, M

    2015-01-01

    We observed NGC 1624-2, the O-type star with the largest known magnetic field Bp~20 kG), in X-rays with the ACIS-S camera onboard the Chandra X-ray Observatory. Our two observations were obtained at the minimum and maximum of the periodic Halpha emission cycle, corresponding to the rotational phases where the magnetic field is the closest to equator-on and pole-on, respectively. With these observations, we aim to characterise the star's magnetosphere via the X-ray emission produced by magnetically confined wind shocks. Our main findings are: (i) The observed spectrum of NGC 1624-2 is hard, similar to the magnetic O-type star Theta 1 Ori C, with only a few photons detected below 0.8 keV. The emergent X-ray flux is 30% lower at the Halpha minimum phase. (ii) Our modelling indicated that this seemingly hard spectrum is in fact a consequence of relatively soft intrinsic emission, similar to other magnetic Of?p stars, combined with a large amount of local absorption (~1-3 x 10^22 cm^-2). This combination is necess...

  12. The evolution of surface magnetic fields in young solar-type stars I: the first 250 Myr

    E-Print Network [OSTI]

    Folsom, C P; Bouvier, J; Lèbre, A; Amard, L; Palacios, A; Morin, J; Donati, J -F; Jeffers, S V; Marsden, S C; Vidotto, A A

    2016-01-01

    The surface rotation rates of young solar-type stars vary rapidly with age from the end of the pre-main sequence through the early main sequence. Important changes in the dynamos operating in these stars may result from this evolution, which should be observable in their surface magnetic fields. Here we present a study aimed at observing the evolution of these magnetic fields through this critical time period. We observed stars in open clusters and stellar associations of known ages, and used Zeeman Doppler Imaging to characterize their complex magnetic large-scale fields. Presented here are results for 15 stars, from 5 associations, with ages from 20 to 250 Myr, masses from 0.7 to 1.2 solar masses, and rotation periods from 0.4 to 6 days. We find complex large-scale magnetic field geometries, with global average strengths from 14 to 140 G. There is a clear trend towards decreasing average large-scale magnetic field strength with age, and a tight correlation between magnetic field strength and Rossby number. ...

  13. 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.

  14. 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...

  15. 3D modeling of magnetic atom traps on type-II superconductor chips

    E-Print Network [OSTI]

    Prigozhin, Leonid

    of Mathematics, Imperial College London, London SW7 2AZ, UK E-mail: sokolovv@bgu.ac.il, leonid September 2014 Published 12 November 2014 Abstract Magnetic traps for cold atoms have become a powerful tool depth, shape, distance from the chip surface, etc) that are necessary when designing magnetic traps

  16. Discovery of a magnetic field in the CoRoT hybrid B-type pulsator HD 43317

    E-Print Network [OSTI]

    Briquet, M; Leroy, B; Pápics, P I

    2013-01-01

    A promising way of testing the impact of a magnetic field on internal mixing (core overshooting, internal rotation) in main-sequence B-type stars is to perform asteroseismic studies of a sample of magnetic pulsators. The CoRoT satellite revealed that the B3IV star HD 43317 is a hybrid SPB/beta Cep-type pulsator that has a wealth of pulsational constraints on which one can perform a seismic modelling, in particular, probing the extent of its convective core and mixing processes. Moreover, indirect indicators of a magnetic field in the star were observed: rotational modulation due to chemical or temperature spots and X-ray emission. Our goal was to directly investigate the field in HD 43317 and, if it is magnetic, to characterise it. We collected data with the Narval spectropolarimeter installed at TBL (T\\'elescope Bernard Lyot, Pic du Midi, France) and applied the least-squares deconvolution technique to measure the circular polarisation of the light emitted from HD 43317. We modelled the longitudinal field me...

  17. Adjustable permanent quadrupoles for the next linear collider

    SciTech Connect (OSTI)

    James T. Volk et al.

    2001-06-22

    The proposed Next Linear Collider (NLC) will require over 1400 adjustable quadrupoles between the main linacs' accelerator structures. These 12.7 mm bore quadrupoles will have a range of integrated strength from 0.6 to 138 Tesla, with a maximum gradient of 141 Tesla per meter, an adjustment range of +0 to {minus}20% and effective lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micron during the 20% adjustment. In an effort to reduce costs and increase reliability, several designs using hybrid permanent magnets have been developed. Four different prototypes have been built. All magnets have iron poles and use Samarium Cobalt to provide the magnetic fields. Two use rotating permanent magnetic material to vary the gradient, one uses a sliding shunt to vary the gradient and the fourth uses counter rotating magnets. Preliminary data on gradient strength, temperature stability, and magnetic center position stability are presented. These data are compared to an equivalent electromagnetic prototype.

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

    DOE Patents [OSTI]

    Haskel, Daniel (Naperville, IL); Lang, Jonathan C. (Naperville, IL); Srajer, George (Oak Park, IL)

    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.

  19. Magnetic fields in O-, B- and A-type stars on the main sequence

    E-Print Network [OSTI]

    Briquet, Maryline

    2014-01-01

    In this review, the latest observational results on magnetic fields in main-sequence stars with radiative envelopes are summarised together with the theoretical works aimed at explaining them.

  20. Magnetic and microwave properties of U-type hexaferrite films with high remanence and low ferromagnetic resonance linewidth

    SciTech Connect (OSTI)

    Su, Zhijuan; Bennett, Steven; Hu, Bolin; Chen, Yajie, E-mail: y.chen@neu.edu; Harris, Vincent G. [Center for Microwave Magnetic Materials and Integrated Circuits, Northeastern University, Boston, Massachusetts 02115, USA and The Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts 02115 (United States)

    2014-05-07

    U-type barium hexaferrite films (Ba{sub 4}Ni{sub 1.4}Co{sub 0.6}Fe{sub 36}O{sub 60}) were deposited on (0001) sapphire substrates by pulsed laser deposition. Microstructure and magnetic properties of the films were characterized by X-ray diffraction, scanning electron microscopy and vibrating sample magnetometry. Ferromagnetic resonance (FMR) measurements were performed at X-band. The results indicate an anisotropy field of ?8 kOe, and the saturation magnetization (4?M{sub s}) of ?3.6 kG. An optimal post-deposition annealing of films results in a strong (0 0?n) crystallographic texture and a high hysteresis loop squareness (M{sub r}/M{sub s}?=?92%) leading to self biased properties. Furthermore, the highly self-biased ferrite films exhibited an FMR linewidth of ?200?Oe. The U-type hexaferrite films having low microwave loss, low magnetic anisotropy field, and high squareness are a suitable alternative to Sc or In doped BaM ferrites that have been the choice material for self-biased microwave devices at X-band frequencies.

  1. 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.

  2. A STRUCTURAL-MAGNETIC STRAIN MODEL FOR MAGNETOSTRICTIVE TRANSDUCERS

    E-Print Network [OSTI]

    strains and forces is provided by a magnetic bias generated by either the surrounding permanent magnet of a cylindrical Terfenol-D rod, a wound wire solenoid, an enclosing permanent magnet and a prestress mechanismA STRUCTURAL-MAGNETIC STRAIN MODEL FOR MAGNETOSTRICTIVE TRANSDUCERS Marcelo J. Dapino Department

  3. MODELING OF EDDY CURRENT LOSS AND TEMPERATURE OF THE MAGNETS

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    MODELING OF EDDY CURRENT LOSS AND TEMPERATURE OF THE MAGNETS IN PERMANENT MAGNET MACHINES@umich.edu Received 24 November 2010 Accepted 16 June 2011 The eddy current loss in the magnets of permanent magnet- mium-iron-boron (NdFeB), and slot/tooth harmonics, there is eddy current loss generated inside

  4. A Landau-type quantization from a Lorentz symmetry violation background with crossed electric and magnetic fields

    E-Print Network [OSTI]

    K. Bakke; H. Belich

    2015-07-14

    We investigate the arising of an analogue of the Landau quantization from a background of the violation of the Lorentz symmetry established by a time-like 4-vector and a field configuration of crossed electric and magnetic field. We also analyse the effects on this Landau-type system subject to a hard-wall confining potential by showing a particular case where a discrete spectrum of energy can be obtained. Further, we analyse the effects of a linear confining potential on the Landau-type system. We show that a quantum effect characterized by the dependence of the cyclotron frequency on the quantum numbers of the system can arise in this analogue of the Landau system. As an example, we calculate the cyclotron frequency associated with ground state of the system.

  5. Remotely addressable magnetic composite micropumps{ Eric Diller, Shuhei Miyashita and Metin Sitti*

    E-Print Network [OSTI]

    Sitti, Metin

    the creation of micron-scale permanent magnets for the application of forces and torques via externally-generated in an addressable manner. We propose micro-scale permanent magnet composites that can be remotely and reversibly, which pair switchable permanent magnets with electromagnets. In these devices, electromagnetic coils

  6. THE DESIGN AND FABRICATION OF A LARGE RECTANGULAR MAGNETIC CUSP PLASMA SOURCE FOR HIGH INTENSITY NEUTRAL BEAM INJECTORS

    E-Print Network [OSTI]

    Biagi, L.A.

    2010-01-01

    generator should be replaced with a larger-volume "magnetic bucket" plasma source,-* in which the walls are lined with permanent magnetsgenerator (Fi^. 1). Design and Fabrication Techniq The permanent magnets

  7. Negative magnetophoresis of submicron species in magnetic nanofluids

    E-Print Network [OSTI]

    Gonzalez, Lino A. (Lino Alberto), 1976-

    2009-01-01

    In this work we studied the focusing and trapping of submicron, nonmagnetic species immersed in a magnetic nanofluid under applied magnetic fields. Focusing was achieved using two pairs of permanent magnets, which forced ...

  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. Structure and magnetic properties of Ce?(Ni/Al/Ga)??—A new phase with the La?Al?? 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 Ce?(Ni/Al/Ga)?? 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 La?Al?? structure type. Wavelength dispersive microprobe provides the composition of Ce?.?????Ni?.?????Al?.?????Ga?.?????. Single crystal refinement provides the composition Ce?Ni?.??Al?.??Ga?.?? 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 Ce?Al??. The effective magnetic moment was found to be ?eff = 1.9?B/Ce, which is lower than the expected value for trivalent Ce (2.54?B/Ce).

  10. 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.

    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 sameway 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. The rangemore »of field magnitudes for which the superconducting-tubes structure is favored shrinks when the field is more in-plane oriented.« less

  11. 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.

    2013-09-01

    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 sameway 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. The range of field magnitudes for which the superconducting-tubes structure is favored shrinks when the field is more in-plane oriented.

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

    SciTech Connect (OSTI)

    Zhang, Hua; Shu, Ting, E-mail: mrtingshu@qq.com; Ju, Jinchuan; Wu, Dapeng [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)] [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    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.

  13. Effect of an Oscillating Magnetic Field on the Release Properties of Magnetic Collagen Gels

    E-Print Network [OSTI]

    Spinu, Leonard

    -15 The oscillating magnetic field was generated by a plate demagnetizer or by moving a permanent magnet backEffect of an Oscillating Magnetic Field on the Release Properties of Magnetic Collagen Gels Vania M The paper describes the effect of an oscillating magnetic field (OMF) on the morphology and release

  14. CERTS Microgrid Laboratory Test Bed

    E-Print Network [OSTI]

    Lasseter, R. H.

    2010-01-01

    and direct-drive permanent magnet generator technology forsystem. The generator is liquid-cooled permanent magnet type

  15. 30TH INTERNATIONAL COSMIC RAY CONFERENCE In-orbit performances of the magnetic spectrometer of PAMELA

    E-Print Network [OSTI]

    Morselli, Aldo

    of the spectrometer of PAMELA is generated by a permanent magnet composed of five identical modules put one on top microstrip sensors, which are placed inside the magnetic cavity of a permanent magnet. The apparatus is used30TH INTERNATIONAL COSMIC RAY CONFERENCE In-orbit performances of the magnetic spectrometer

  16. Type-I superconductor pick-up coil in superconducting quantum interference device-based ultra-low field nuclear magnetic resonance

    SciTech Connect (OSTI)

    Hwang, Seong-min, E-mail: smhwang@kriss.re.kr; Kim, Kiwoong; Kyu Yu, Kwon; Lee, Seong-Joo; Hyun Shim, Jeong [Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Körber, Rainer [Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin (Germany); Magnicon GmbH, Division Berlin, Abbestraße 2-12, D-10587 Berlin (Germany); Burghoff, Martin [Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin (Germany)

    2014-02-10

    In ultra-low field nuclear magnetic resonance (ULF-NMR) with strong prepolarization field (B{sub p}), type-II superconducting pick-up coils may be vulnerable to flux pinning from the strong B{sub p}. Pick-up coils made of NbTi, Nb, and Pb were evaluated in terms of acquired NMR signal quality. The type-II pick-up coils showed degraded signals above 61?mT maximum exposure, while the Pb pick-up coil exhibited no such degradation. Furthermore, a negative counter pulse following a strong B{sub p} was shown to follow magnetic hysteresis loop to unpin the trapped flux in the type-II pick-up coil and restore the NMR signal.

  17. 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?O·H?O 2, have been synthesized via the hydrothermal technique and characterized by single crystal X-ray diffraction analyses, IR, XPS, TG analysis, UV–DRS, 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)?]²? 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 0–50 mT in the range of 600–1000 cm?¹, 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.

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

    Office of Environmental Management (EM)

    3 Permanent and Nonpermanent Positions, Appointments, & CHRIS Codes POLICY GUIDANCE MEMORANDUM 23 Permanent and Nonpermanent Positions, Appointments, & CHRIS Codes DOE Guidance -...

  19. 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.

  20. Comparing Two Types of Magnetically- Coupled Adjustable Speed Drives with Variable Frequency Drives in Pump and Fan Applications 

    E-Print Network [OSTI]

    Anderson, K. J.; Chvala, W. D.

    2003-01-01

    This paper presents the results from laboratory tests on MagnaDrive Corporations fixed-magnet magnetically-coupled adjustable speed drive (MC-ASD) and Coyote Electronics electromagnetic MC-ASD as compared to a typical variable frequency drive (VFD...

  1. Numerical studies on the effect of normal-metal coatings on the magnetization characteristics of type-II superconductors

    E-Print Network [OSTI]

    Hampshire, Damian

    Numerical studies on the effect of normal-metal coatings on the magnetization characteristics; published 19 April 2005 Magnetic properties of superconductors coated with metals of arbitrary resistivity N in the coating is reduced, the initial vortex penetration field Hp N does not decrease monotonically from

  2. THE POST-MERGER MAGNETIZED EVOLUTION OF WHITE DWARF BINARIES: THE DOUBLE-DEGENERATE CHANNEL OF SUB-CHANDRASEKHAR TYPE Ia SUPERNOVAE AND THE FORMATION OF MAGNETIZED WHITE DWARFS

    SciTech Connect (OSTI)

    Ji Suoqing; Fisher, Robert T. [University of Massachusetts Dartmouth, Department of Physics, 285 Old Westport Road, North Dartmouth, MA 02740 (United States); Garcia-Berro, Enrique [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, c/Esteve Terrades, 5, E-08860 Castelldefels (Spain); Tzeferacos, Petros; Jordan, George; Lee, Dongwook [Center for Astrophysical Thermonuclear Flashes, The University of Chicago, Chicago, IL 60637 (United States); Loren-Aguilar, Pablo [School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom); Cremer, Pascal [Bethe Center for Theoretical Physics, Universitaet Bonn, Nussallee 12, D-53115 Bonn (Germany); Behrends, Jan [Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin (Germany)

    2013-08-20

    Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-degenerate channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf binaries to include the effect of the magnetic field. In these systems, the two white dwarfs complete a final merger on a dynamical timescale, and are tidally disrupted, producing a rapidly rotating white dwarf merger surrounded by a hot corona and a thick, differentially rotating disk. The disk is strongly susceptible to the magnetorotational instability (MRI), and we demonstrate that this leads to the rapid growth of an initially dynamically weak magnetic field in the disk, the spin-down of the white dwarf merger, and to the subsequent central ignition of the white dwarf merger. Additionally, these magnetized models exhibit new features not present in prior hydrodynamic studies of white dwarf mergers, including the development of MRI turbulence in the hot disk, magnetized outflows carrying a significant fraction of the disk mass, and the magnetization of the white dwarf merger to field strengths {approx}2 Multiplication-Sign 10{sup 8} G. We discuss the impact of our findings on the origins, circumstellar media, and observed properties of SNe Ia and magnetized white dwarfs.

  3. Magnetic Resonance Imaging 1 A new global optimization algorithm and its application to a

    E-Print Network [OSTI]

    Neumaier, Arnold

    by the uniformity of the magnetic field generated by this magnet, in that, the more uniform is the magnetic field a low field dedicated magnet is that of using permanent magnets surrounded by an iron yoke to amplifyMagnetic Resonance Imaging 1 A new global optimization algorithm and its application to a Magnetic

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

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

    1 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation ape020burress2011o...

  5. 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...

  6. A doubly-fed permanent magnet generator for wind turbines

    E-Print Network [OSTI]

    Thomas, Andrew J. (Andrew Joseph), 1981-

    2004-01-01

    Optimum extraction of energy from a wind turbine requires that turbine speed vary with wind speed. Existing solutions to produce constant-frequency electrical output under windspeed variations are undesirable due to ...

  7. High Temperature, Buried Permanent Magnet, Brushless DC Motor 

    E-Print Network [OSTI]

    Zhang, Zhengxin

    2010-10-12

    Outputs, Back EMF and Phase Current in One Electric Cycle ................ 31 Fig. 3-9 Hall Effect Sensor Positions ............................................................................. 33 Fig. 3-10 State One... 1- HIGH LEVEL HALL SENSOR INPUT 0- LOW LEVEL HALL SENSOR INPUT H- HIGH OR SWITCHING MOTOR OUTPUT L- LOW MOTOR OUTPUT X- MOTOR OUTPUT IS OFF (FLOATING) In one electrical cycle, the Hall Effect sensor outputs, Back EMF, Motor Phase inputs have a...

  8. Permanent magnet assisted synchronous reluctance motor, design and performance improvement 

    E-Print Network [OSTI]

    Niazi, Peyman

    2006-04-12

    . current........................................................................75 2- 33 Saturation effect due to the PM of the rotor.........................................................75 2- 34 Line-to-line back-EMF in PMa...-SynRM. .............................................................76 2- 35 Torque-angle curves of the PMa-SynRM and SynRM. .......................................77 2- 36 Stator and rotor laminations of the proposed PMa-SynRM.................................78 2- 37 Actual back-EMF line voltage at 1800...

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

    DOE Patents [OSTI]

    Hsu, John S. (Oak Ridge, TN)

    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.

  10. High force density linear permanent magnet motors : "electromagnetic muscle actuators"

    E-Print Network [OSTI]

    Ruddy, Bryan P. (Bryan Paul), 1983-

    2012-01-01

    Actuator performance represents a key constraint on the capability of many engineered devices. Performance of these devices is often exceeded by their muscle-powered natural counterparts, inspiring the development of new, ...

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy Bills and Reduce CarbonEnergyDepartment13 FederalJuly 28,1Department of

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy Bills and Reduce CarbonEnergyDepartment13 FederalJuly 28,1Department

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy Bills and Reduce CarbonEnergyDepartment13 FederalJuly

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy Bills andOrder 422.1, CONDUCT PDepartmentOrder (2013-SE-14001)Energy 2

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy Bills andOrder 422.1, CONDUCT PDepartmentOrder (2013-SE-14001)Energy

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy Bills andOrder 422.1, CONDUCT PDepartmentOrder

  17. A New Class of Switched Reluctance Motors without Permanent Magnets |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Financing ToolInternationalReportOffice | DepartmentVery1, in: Statement

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Financing ToolInternationalReportOffice | DepartmentVery1, in: StatementDepartment of Energy 0

  19. High Performance Permanent Magnets for Advanced Motors | Department of

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12,ExecutiveFinancing ProgramsDepartment of¡High Performance ComputingEnergy

  20. Jiangxi Jinli Permanent Magnet Technology Co Ltd | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OFAMERICA'SHeavyAgency (IRENA) Jump to: navigation,Wind Jump to:FAWWende NewJinli

  1. 2007 Nature Publishing Group Nuclear magnetic resonance imaging

    E-Print Network [OSTI]

    Leonardo, Degiorgi

    to sense the magnetic force generated between the tip and spins in a sample. Magnetic resonance is used for the present work is the development of magnetic tips that generate magnetic field gradients as high as 1 of the technique on a patterned CaF2 test object. Unlike the permanent magnet tips previously used for

  2. 862 IEEE TRANSACTIONS ON ENERGY CONVERSION, VOL. 26, NO. 3, SEPTEMBER 2011 Analytical Method for Magnetic Field Calculation in

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    -pole 60-slot double-rotor axial-flux PM motor was proposed for electric vehicles [4]. In these machines for Magnetic Field Calculation in a Low-Speed Permanent-Magnet Harmonic Machine Linni Jian, Member, IEEE-drive low-speed permanent-magnet machines. The machines derived from the magnetic-gearing ef- fect can

  3. Synthesis of NiCoMnX (X = In, Al) Heusler-type Magnetic Shape Memory Alloy Thin Films 

    E-Print Network [OSTI]

    Rios, Steven Eli

    2014-08-13

    Magnetic shape memory alloys are a class of shape memory alloys, and therefore exhibit a thermoelastic martensite phase transformation between symmetric and asymmetric crystalline states induced by appropriate temperature ...

  4. B fields in OB stars (BOB): on the detection of weak magnetic fields in the two early B-type stars beta CMa and epsilon CMa

    E-Print Network [OSTI]

    Fossati, L; Morel, T; Langer, N; Briquet, M; Carroll, T A; Hubrig, S; Nieva, M F; Oskinova, L M; Przybilla, N; Schneider, F R N; Scholler, M; Simon-Diaz, S; Ilyin, I; de Koter, A; Reisenegger, A; Sana, H

    2014-01-01

    Within the context of the "B fields in OB stars (BOB)" collaboration, we used the HARPSpol spectropolarimeter to observe the early B-type stars beta CMa (HD44743; B1 II/III) and epsilon CMa (HD52089; B1.5 II). For both stars, we consistently detected the signature of a weak (<30 G in absolute value) longitudinal magnetic field. We determined the physical parameters of both stars and characterise their X-ray spectrum. For beta CMa, our mode identification analysis led to determining a rotation period of 13.6+/-1.2 days and of an inclination angle of the rotation axis of 57.6+/-1.7 degrees, with respect to the line of sight. On the basis of these measurements and assuming a dipolar field geometry, we derived a best fitting obliquity of ~22 degrees and a dipolar magnetic field strength (Bd) of ~100 G (60magnetic massive stars. For epsilon CMa we could only determine a lower limit on the dipolar magnetic field strength of 13 G. For this s...

  5. Global modeling of cancer gene expression signa-Cancer leads to permanent changes in cell's physiological state and various

    E-Print Network [OSTI]

    Kaski, Samuel

    Global modeling of cancer gene expression signa- tures Cancer leads to permanent changes in cell cancer types. Less is known about the underlying biological processes, or relationships between different cancer types with respect to these changes. While each specific cancer type has a set of unique

  6. Magnetic multipole redirector of moving plasmas

    DOE Patents [OSTI]

    Crow, James T. (Albuquerque, NM); Mowrer, Gary R. (Cedar Crest, NM)

    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.

  7. Permanent Field Plot Methodology and Equipment1 Thomas G. Cole2

    E-Print Network [OSTI]

    of what changes occur over time in indigenous agroforestry systems. Permanent plot methodology can be used to conduct several different types of surveys. Two that are appropriate to the Pacific are island-wide and case studies. An island-wide survey is ideal for obtaining baseline information concerning agroforest

  8. 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.

  9. 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.

  10. MODELING OF EDDY CURRENT LOSS AND TEMPERATURE OF THE MAGNETS

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    MODELING OF EDDY CURRENT LOSS AND TEMPERATURE OF THE MAGNETS IN PERMANENT MAGNET MACHINES the performance of the machine. This paper presents the modeling and analysis of eddy current loss in surface- mounted-magnets PM synchronous motors (SPMSM) and interior-magnets PM synchronous motors (IPMSM), operated

  11. Near-field-magnetic-tweezer manipulation of single DNA molecules Jie Yan, Dunja Skoko, and John F. Marko

    E-Print Network [OSTI]

    Croquette, Vincent

    with 3- m-diameter paramagnetic particles. A small, permanent magnet that can be moved as close as 10 m in other recent "magnetic-tweezer" studies. Our instrument generates these forces in the focal plane also have the disadvantage of being quite expensive. Conventional MT using permanent magnets about 1 mm

  12. 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.

  13. Advanced Penning-type ion source development and passive beam focusing techniques for an associated particle imaging neutron generator

    E-Print Network [OSTI]

    Sy, Amy

    2013-01-01

    cusp magnetic field to the plasma confinement and resultantaxial magnetic field and the resultant magnetic confinementaxial magnetic field imposes a type of magnetic confinement

  14. 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.

  15. A mesoscopic network model for permanent set in crosslinked elastomers...

    Office of Scientific and Technical Information (OSTI)

    model for permanent set in crosslinked elastomers A mesoscopic computational model for polymer networks and composites is developed as a coarse-grained representation of the...

  16. Magnetic machines and power electronics for power MEMS applications

    E-Print Network [OSTI]

    Das, Sauparna, 1979-

    2005-01-01

    This thesis presents the modeling, design, and characterization of microfabricated, surface-wound, permanent-magnet (PM) generators, and their power electronics, for use in Watt-level Power MEMS applications such as a ...

  17. Low-field classroom nuclear magnetic resonance system

    E-Print Network [OSTI]

    Zimmerman, Clarissa Lynette

    2010-01-01

    The goal of this research was to develop a Low-field Classroom NMR system that will enable hands-on learning of NMR and MRI concepts in a Biological-Engineering laboratory course. A permanent magnet system, designed using ...

  18. Fluorescent lamp with static magnetic field generating means

    DOE Patents [OSTI]

    Moskowitz, Philip E. (Peabody, MA); Maya, Jakob (Brookline, MA)

    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.

  19. 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.

  20. Magnesium substitutions in rare-earth metal germanides with the Gd5Si4 type. Synthesis, structure determination and magnetic properties of RE5-xMgxGe4 (RE=Gd-Tm, Lu and Y)

    SciTech Connect (OSTI)

    Sarrao, J L [Los Alamos National Laboratory; Thompson, Joe D [Los Alamos National Laboratory; Tobash, P H [UNIV. OF DE; Bobev, S [UNIV. OF DE

    2009-01-01

    A series of magnesium-substituted rare-earth metal germanides with a general formula RE{sub 5-x}Mg{sub x}Ge{sub 4} (x {approx} 1.0-2.3; RE =Gd-Tm, Lu, Y) have been synthesized by high-temperature reactions and structurally characterized by single-crystal X-ray diffraction. These compounds crystallize with the common Gd{sub 5}Si{sub 4} type in the orthorhombic space group Pnma (No. 62; Z =4; Pearson's code oP36) and do not appear to undergo temperature-induced crystallographic phase transitions down to 120 K. Replacing rare-earth metal atoms with Mg, up to nearly 45 % at., reduces the valence electron count and is clearly expressed in the subtle changes of the Ge-Ge and metal-metal bonding. Magnetization measurements as a function of the temperature and the applied field reveal complex magnetic structures at cryogenic temperatures, and Curie-Weiss paramagnetic behavior at higher temperatures. The observed local moment magnetism is consistent with RE+ ground states in all cases. In the magnetically ordered phases, the magnetization cannot reach saturation in fields up to 50 kOe. The structural trends across the series and the variations of hte magnetic properties as a function of the Mg content are also discussed. KEYWORDS: Rare-earth intermetallics, germanides, crystal structure,Gd{sub 5}Si{sub 4} type.

  1. 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.

  2. 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 ?{sub eff}=7.87(1) ?{sub B}/Eu atom and ?{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.

  3. Combined passive magnetic bearing element and vibration damper

    DOE Patents [OSTI]

    Post, Richard F. (Walnut Creek, CA)

    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. 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.

  5. 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.

  6. Analytical Model of Magnet Eddy-Current Volume Losses in Multi-phase PM Machines

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Analytical Model of Magnet Eddy-Current Volume Losses in Multi-phase PM Machines with Concentrated, 94000 Créteil France Abstract--this paper studies magnet eddy-current losses in permanent magnet (PM calculations. Keywords--Traction, Concentrated Winding, Eddy- Current, Volume Magnet Losses, Multiphase Machine

  7. Magnetic cooling at Risoe DTU

    E-Print Network [OSTI]

    Nielsen, K K; Jensen, J B; Bahl, C R H; Pryds, N; Smith, A; Nordentoft, A; Hattel, J

    2009-01-01

    Magnetic refrigeration at room temperature is of great interest due to a long-term goal of making refrigeration more energy-efficient, less noisy and free of any environmentally hostile materials. A refrigerator utilizing an active magnetic regenerator (AMR) is based on the magnetocaloric effect, which manifests itself as a temperature change in magnetic materials when subjected to a varying magnetic field. In this work we present the current state of magnetic refrigeration research at Risoe DTU with emphasis on the numerical modeling of an existing AMR test machine. A 2D numerical heat-transfer and fluid-flow model that represents the experimental setup is presented. Experimental data of both no-heat load and heat load situations are compared to the model. Moreover, results from the numerical modeling of the permanent magnet design used in the system are presented.

  8. Permanence : aligning architecture, nuclear waste, and the Public

    E-Print Network [OSTI]

    Maher, John, III (John Edward)

    2014-01-01

    Permanence is intended as a provocation to question the current relationship of time and architecture. Architecture has always had a relationship with time, but historically this relationship has been troubled. In 2013 we ...

  9. 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.

  10. 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.

  11. 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.

  12. Nuclear Magnetic Resonance: Portable and integrated Lead: P. Poulichet.

    E-Print Network [OSTI]

    Baudoin, Geneviève

    Nuclear Magnetic Resonance: Portable and integrated Lead: P. Poulichet. Permanent members: L. Rousseau, A. Fakri. Associated researchers: C. Delabie, A. Exertier. Portable Nuclear Magnetic Resonance : our work in the field of nuclear magneto resonance is focused on the design and the realization

  13. Molecular CP-violating magnetic moment Andrei Derevianko1

    E-Print Network [OSTI]

    Titov, Anatoly

    Molecular CP-violating magnetic moment Andrei Derevianko1 and M. G. Kozlov2 1 Department of Physics Received 26 April 2005; published 6 October 2005 A concept of CP-violating T,P-odd permanent molecular magnetic moments CP is introduced. We relate the moments to the electric dipole moment of electron e

  14. If yes, date your card was issued: Card number Enclose a photocopy of the front and back of your Permanent Resident, Asylee, or Refugee Card

    E-Print Network [OSTI]

    of your Permanent Resident, Asylee, or Refugee Card Are you a Permanent Resident, Asylee, or Refugee

  15. From permanence to total availability: a quantum conceptual upgrade

    E-Print Network [OSTI]

    Massimiliano Sassoli de Bianchi

    2011-06-14

    We consider the classical concept of time of permanence and observe that its quantum equivalent is described by a bona fide self-adjoint operator. Its interpretation, by means of the spectral theorem, reveals that we have to abandon not only the idea that quantum entities would be characterizable in terms of spatial trajectories but, more generally, that they would possess the very attribute of spatiality. Consequently, a permanence time shouldn't be interpreted as a "time" in quantum mechanics, but as a measure of the total availability of a quantum entity in participating to a process of creation of a spatial localization.

  16. High performance hybrid magnetic structure for biotechnology applications

    DOE Patents [OSTI]

    Humphries, David E. (El Cerrito, CA); Pollard, Martin J. (El Cerrito, CA); Elkin, Christopher J. (San Ramon, CA)

    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.

  17. 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.

  18. Permanent carbon dioxide storage in deep-sea sediments

    E-Print Network [OSTI]

    Schrag, Daniel

    Permanent carbon dioxide storage in deep-sea sediments Kurt Zenz House* , Daniel P. Schrag, Cambridge, MA 02138; Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139; and §Earth Engineering Center, Columbia University, New York, NY 10027

  19. Behavior of fullscale concrete segmented pipelines under permanent ground displacements

    E-Print Network [OSTI]

    Michalowski, Radoslaw L.

    Behavior of fullscale concrete segmented pipelines under permanent ground displacements Junhee, Indiana; d Department of Civil Engineering, Merrimack College, MA ABSTRACT Concrete pipelines are one pipelines and eventually lead to joint failures. In order to understand and model the typical failure

  20. 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.

  1. Permanent laser conditioning of thin film optical materials

    DOE Patents [OSTI]

    Wolfe, C. Robert (Palo Alto, CA); Kozlowski, Mark R. (Pleasanton, CA); Campbell, John H. (Livermore, CA); Staggs, Michael (Tracy, CA); Rainer, Frank (Livermore, CA)

    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.

  2. 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.'

  3. Phoenix: Detecting and Recovering from Permanent Processor Design Bugs

    E-Print Network [OSTI]

    Torrellas, Josep

    Phoenix: Detecting and Recovering from Permanent Processor Design Bugs with Programmable Hardware://iacoma.cs.uiuc.edu 14 Phoenix Conceptual Design Signature Buffer Bug Detection Unit (BDU) Global Recovery Unit Signal of Phoenix Subsystem SSUBDU Subsystem BDUSSUHUB Neighborhood To Recovery Unit IO Cntrl.L1 CacheFetch Unit

  4. Magnetic fields in massive stars

    E-Print Network [OSTI]

    S. Hubrig; M. Schoeller; M. Briquet; M. A. Pogodin; R. V. Yudin; J. F. Gonzalez; T. Morel; P. De Cat; R. Ignace; P. North; G. Mathys; G. J. Peters

    2007-12-02

    We review the recent discoveries of magnetic fields in different types of massive stars and briefly discuss strategies for spectropolarimetric observations to be carried out in the future.

  5. Magnetic fields in massive stars

    E-Print Network [OSTI]

    Hubrig, S; Briquet, M; Pogodin, M A; Yudin, R V; González, J F; Morel, T; De Cat, P; Ignace, R; North, P; Mathys, G; Peters, G J

    2007-01-01

    We review the recent discoveries of magnetic fields in different types of massive stars and briefly discuss strategies for spectropolarimetric observations to be carried out in the future.

  6. Use of Retrievable Compared to Permanent Inferior Vena Cava Filters: A Single-Institution Experience

    SciTech Connect (OSTI)

    Ha, Thuong G. Van [University of Chicago, Department of Radiology, Section of Vascular and Interventional Radiology (United States)], E-mail: tgvanha@uchicago.edu; Chien, Andy S. [Pritzker School of Medicine, University of Chicago (United States); Funaki, Brian S.; Lorenz, Jonathan [University of Chicago, Department of Radiology, Section of Vascular and Interventional Radiology (United States); Piano, Giancarlo [University of Chicago, Department of Surgery (United States); Shen, Maxine [Pritzker School of Medicine, University of Chicago (United States); Leef, Jeffrey [University of Chicago, Department of Radiology, Section of Vascular and Interventional Radiology (United States)

    2008-03-15

    The purpose of this study was to review the use, safety, and efficacy of retrievable inferior vena cava (IVC) filters in their first 5 years of availability at our institution. Comparison was made with permanent filters placed in the same period. A retrospective review of IVC filter implantations was performed from September, 1999, to September, 2004, in our department. These included both retrievable and permanent filters. The Recovery nitinol and Guenther tulip filters were used as retrievable filters. The frequency of retrievable filter used was calculated. Clinical data and technical data related to filter placement were reviewed. Outcomes, including pulmonary embolism, complications associated with placement, retrieval, or indwelling, were calculated. During the study period, 604 IVC filters were placed. Of these, 97 retrievable filters (16%) were placed in 96 patients. There were 53 Recovery filter and 44 Tulip filter insertions. Subjects were 59 women and 37 men; the mean age was 52 years, with a range of from 18 to 97 years. The placement of retrievable filters increased from 2% in year 1 to 32% in year 5 of the study period. The total implantation time for the permanent group was 145,450 days, with an average of 288 days (range, 33-1811 days). For the retrievable group, the total implantation time was 21,671 days, with an average of 226 days (range, 2-1217 days). Of 29 patients who returned for filter retrieval, the filter was successfully removed in 28. There were 14 of 14 successful Tulip filter retrievals and 14 of 15 successful Recovery filter retrievals. In one patient, after an indwelling period of 39 days, a Recovery nitinol filter could not be removed secondary to a large clot burden within the filter. For the filters that were removed, the mean dwell time was 50 days for the Tulip type and 20 days for the Recovery type. Over the follow-up period there was an overall PE incidence of 1.4% for the permanent group and 1% for the retrieval group. In conclusion, there was an increase in the use of retrievable filters over the study period and an overall increase in the total number of filters implanted. The increased use of these filters appeared to be due to expanded indications predicated by their retrievability. Placement and retrieval of these filters have a low risk of complications, and retrievable filters appeared effective, as there was low rate of clinically significant pulmonary embolism associated with these filters during their indwelling time.

  7. Magnetic actuation and transition shapes of a bistable spherical cap

    E-Print Network [OSTI]

    Loukaides, E. G.; Smoukov, S. K.; Seffen, K. A.

    2015-01-22

    6.11, ABAQUS Documentation, Dassault Systèmes, Providence, RI, 2011. [23] M. McCraig and A.G. Clegg, Permanent Magnets in Theory and Practice, 2nd ed., John Wiley and Sons, New York, 1987. [24] S. Blinder, Magnetic field of a cylindrical bar magnet... one stable shape. As potential actuator elements, only the transition between states needs to be “powered” continuously and not their rest configurations; thus, there are positive implications for saving energy during operation. Description...

  8. Superconducting Magnet Division

    E-Print Network [OSTI]

    Ohta, Shigemi

    Superconducting Magnet Division MAGNETIC DESIGN OF E-LENS SOLENOID AND CORRECTOR SYSTEM FOR RHIC* R.6 A gun collectors gun Combined Horizontal and Vertical Corrector Design Both types of dipole correctors. Gupta, M. Anerella, W. Fischer, G. Ganetis, X. Gu, A. Ghosh, A. Jain, P. Kovach, A. Marone, S. Plate, A

  9. 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.

  10. Self-nanoscaling of the soft magnetic phase in bulk SmCo/Fe nanocomposite magnets

    E-Print Network [OSTI]

    Liu, J. Ping

    in high power density applications, such as wind power turbines and electric motors in hybrid vehicles that these excellent properties are achieved at a low cost. Sm­Co intermetallic compounds (including SmCo5, Sm2Co17)max, the figure of merit of a permanent magnet. To reduce the materials costs, it is desirable to lower

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

    DOE Patents [OSTI]

    Anderson, Oscar A. (Berkeley, CA); Chan, Chun F. (Hayward, CA); Leung, Ka-Ngo (Hercules, CA)

    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.

  12. An issue of permanence: assessing the effectiveness of temporary carbon storage

    E-Print Network [OSTI]

    Herzog, Howard J.

    In this paper, we present a method to quantify the effectiveness of carbon mitigation options taking into account the "permanence" of the emissions reduction. While the issue of permanence is most commonly associated with ...

  13. 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.

  14. 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.

  15. 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. [Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2 (Canada) and Department of Oncology, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); Department of Physics, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2 (Canada); Department of Oncology, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada) and Department of Physics, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada)

    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)]. Results: As expected, RE{sub preplan} for our edema model indicated underdosage in the calculation volume with a clear dependence on seed and calculation point positions, and increased with increasing values of {Delta} and T. Values of RE{sub preplan} were generally larger near the ends of the virtual prostate in the RPC phantom compared with more central locations. For edema characteristics similar to the population average values previously measured at our center, i.e., {Delta}=0.2 and T=28 d, mean values of RE{sub preplan} in an axial plane located 1.5 cm from the center of the seed distribution were 8.3% for {sup 131}Cs seeds, 7.5% for {sup 103}Pd seeds, and 2.2% for {sup 125}I seeds. Maximum values of RE{sub preplan} in the same plane were about 1.5 times greater. Note that detailed results strictly apply only for loose seed implants where the seeds are fixed in tissue and move in synchrony with that tissue. Conclusions: A dose calculation method for permanent prostate implants incorporating spatially anisotropic linearly time-resolving edema was developed for which cumulative dose can be written in closed form. The method yields values for RE{sub preplan} that differ from those for spatially isotropic edema. The method is suitable for calculating pre- and postimplant dosimetry correction factors for clinical seed configurations when edema characteristics can be measured or estimated.

  16. Semiclassical bounds in magnetic bottles

    E-Print Network [OSTI]

    Diana Barseghyan; Pavel Exner; Hynek Kovarik; Timo Weidl

    2015-01-13

    The aim of the paper is to derive spectral estimates into several classes of magnetic systems. They include three-dimensional regions with Dirichlet boundary as well as a particle in $\\mathbb{R}^3$ confined by a local change of the magnetic field. We establish two-dimensional Berezin-Li-Yau and Lieb-Thirring-type bounds in the presence of magnetic fields and, using them, get three-dimensional estimates for the eigenvalue moments of the corresponding magnetic Laplacians.

  17. 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.

  18. 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.

  19. Cycles of magnetic activity in solar-type stars. The place of the Sun among the stars with different levels of coronal and chromospheric activity

    E-Print Network [OSTI]

    Bruevich, E A; Shimanovskaya, E V

    2015-01-01

    Activity of the chromospheres and coronas of the stars of late (F, G, K) spectral classes and also their cyclic activity is analyzed on the observational data of solar-type stars from Mount Wilson "HK-project". The chromospheric and coronal activity of "HK-project stars" and the Sun was compared to the stars with active atmospheres observed in Planets Search Programs. It is shown that the cyclic activity begins to occur in stars, close by their spectral type to the Sun and becomes more pronounced at K-stars. The results of a comparative analysis of the characteristics of chromospheric and coronal activity of the Sun and F, G and K-stars are presented.

  20. Magnetic levitation system for moving objects

    DOE Patents [OSTI]

    Post, Richard F. (Walnut Creek, CA)

    1998-01-01

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

  1. 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.

  2. Magnetically leviated superconducting bearing

    DOE Patents [OSTI]

    Weinberger, Bernard R. (Avon, CT); Lynds, Jr., Lahmer (Glastonbury, CT)

    1993-01-01

    A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.

  3. Computer Based Motor Parameter Determination for High Speed Operation of Permanent Magnet Synchronous Machines

    E-Print Network [OSTI]

    Szabados, Barna

    Synchronous Machines B. Szabados and U. Schaible McMaster University 1280 Main St. W., Hamilton, Ontario PM synchronous machine parameters in the high speed operating range. The theory and real interior PM synchronous machine at up to 8000 rpm. Results are presented which show a significant variation

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

    Office of Scientific and Technical Information (OSTI)

    roughness for machine tool drives depends on motor torque quality. For propulsion and vehicle motors, quietness and smoothness are strongly required. The severity of torque...

  5. 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

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

    E-Print Network [OSTI]

    Waldmann, Ole

    2011-01-01

    Compact High-Yield Neutron Generator, AIP Conf. Proc. 1336 (a Sealed-Tube Neutron Generator O. Waldmann ? B. Ludewigtthrough a 60 · 6 mm 2 tron generator. When operated with a

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

    E-Print Network [OSTI]

    Waldmann, Ole

    2011-01-01

    a Compact High-Yield Neutron Generator O. Waldmann 1 , B.Compact High-Yield Neutron Generator ? O. Waldmann a and B.yield compact neutron generator for active interrogation

  8. Design and Control of a Floating Wave-Energy Converter Utilizing a Permanent Magnet Linear Generator

    E-Print Network [OSTI]

    Tom, Nathan Michael

    2013-01-01

    Force . . . . . . . . . . . . . . . . . . . .GeneratorGenerator Dry Bench Test . . . . . . . . .4.5.7 Generator Power

  9. Sensorless Speed Control of Permanent Magnet-Assisted Synchronous Reluctance Motor (PMa-SynRM) 

    E-Print Network [OSTI]

    Chakali, Anil K.

    2011-02-22

    for their help, particularly Robert Vartanian, Jeihoon Baek, Behrooz Nikbakhtan, Nicholas Frank, Suengdeog Choi, Mashid Amirabadi, Mehran Mirjafari, Vivek Sundaram, Anand Balakrishnan, Yateendra Deshpande, Dr. Salman Talebi and Dr. Baris Ozturk. Finally, I...

  10. A fully-integrated multi-watt permanent-magnet turbine generator

    E-Print Network [OSTI]

    Yen, Bernard Chih-Hsun, 1981-

    2008-01-01

    The energy density available from batteries is increasingly becoming a limiting factor in the capabilities of portable electronics. As a result, there is a growing need for compact, high energy density sources. This thesis ...

  11. Design and Control of a Floating Wave-Energy Converter Utilizing a Permanent Magnet Linear Generator

    E-Print Network [OSTI]

    Tom, Nathan Michael

    2013-01-01

    electrical generator technology for wave energy converters,”seen, clean technologies, such as ocean wave energy, presentwave energy point absorber,” Proceedings of the IFAC Conference on Control Methodologies and Technology

  12. Design and Control of a Floating Wave-Energy Converter Utilizing a Permanent Magnet Linear Generator

    E-Print Network [OSTI]

    Tom, Nathan Michael

    2013-01-01

    Conference on Electric Machines and Drives (IEMDC-03), JuneConference on Electric Machines & Drives (IEMDC-07), 2,Vernier hybrid machines,” IEEE Proceedings Electric Power

  13. Performance of a permanent-magnet helicon source at 27 and 13 MHz Francis F. Chen

    E-Print Network [OSTI]

    Chen, Francis F.

    plasma for roll-to-roll process- ing. In the present work, one of the helicon sources in the array for other applications such as spacecraft thrusters or optical coatings. It has been shown4 that helicon

  14. Operational behavior of a double-fed permanent magnet generator for wind turbines

    E-Print Network [OSTI]

    Reddy, Sivananda Kumjula

    2005-01-01

    Greater efficiency in wind turbine systems is achieved by allowing the rotor to change its rate of rotation as the wind speed changes. The wind turbine system is decoupled from the utility grid and a variable speed operation ...

  15. Vibration sensors utilizing fiber fabry-perot interferometers and permanent magnets 

    E-Print Network [OSTI]

    Conkey, Andrew P.

    2009-05-15

    , the effect of the non-linearity can be removed by signal processing. The fiber optic gap sensor (FOGS) developed has a sensitivity of 250 mV/mil for a 30 mil gap to 50 mV/mil for a 65 mil gap and a dynamic range up to 820 Hz. An advantage of the FOGS over...

  16. Direct torque control of permanent magnet synchronous motors with non-sinusoidal back-EMF 

    E-Print Network [OSTI]

    Ozturk, Salih Baris

    2009-05-15

    This work presents the direct torque control (DTC) techniques, implemented in four- and six-switch inverter, for brushless dc (BLDC) motors with non-sinusoidal back- EMF using two and three-phase conduction modes. First of all, the classical direct...

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

    E-Print Network [OSTI]

    Waldmann, Ole

    2011-01-01

    densities, high atomic fractions, and high power e?cienciesa high atomic species fraction at signi?cantly lower power

  18. Design and Control of a Floating Wave-Energy Converter Utilizing a Permanent Magnet Linear Generator

    E-Print Network [OSTI]

    Tom, Nathan Michael

    2013-01-01

    electrical generator technology for wave energy converters,”wave energy point absorber,” Proceedings of the IFAC Conference on Control Methodologies and Technologyseen, clean technologies, such as ocean wave energy, present

  19. Design and Control of a Floating Wave-Energy Converter Utilizing a Permanent Magnet Linear Generator

    E-Print Network [OSTI]

    Tom, Nathan Michael

    2013-01-01

    control of resonant wave energy devices,” Phil. Trans. R.control of deep water wave energy devices using an activecapture of a wave energy device by inertia adjustment,”

  20. 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).

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent Bonding in ActinideRail betweenProtectionCurrent CO-OP

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired SolarAboutXuRod Hunt (208) 386-52542Devices" Inventor..--.. Ali

  3. Robust ferromagnetism in the compressed permanent magnet Sm 2 Co 17

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference) | SciTech Connect Robust emergent climate phenomena associated

  4. Robust ferromagnetism in the compressed permanent magnet Sm2Co17 (Journal

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference) | SciTech Connect Robust emergent climate phenomena

  5. Robust ferromagnetism in the compressed permanent magnet Sm2Co17 (Journal

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference) | SciTech Connect Robust emergent climate phenomenaArticle) |

  6. Detrital remanent magnetization in the solar nebula

    E-Print Network [OSTI]

    Fu, Roger Rennan

    We introduce the theoretical basis of a new form of remanent magnetization that likely formed on primitive bodies in the solar system. Accretional detrital remanent magnetization (ADRM) operates via “compass needle”-type ...

  7. Flywheel energy storage with superconductor magnetic bearings

    DOE Patents [OSTI]

    Weinberger, Bernard R. (Avon, CT); Lynds, Jr., Lahmer (Glastonbury, CT); Hull, John R. (Hinsdale, IL)

    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.

  8. Iron-Nitride-Based Magnets: Synthesis and Phase Stabilization of Body Center Tetragonal (BCT) Metastable Fe-N Anisotropic Nanocomposite Magnet- A Path to Fabricate Rare Earth Free Magnet

    SciTech Connect (OSTI)

    None

    2012-01-01

    REACT Project: The University of Minnesota will develop an early stage prototype of an iron-nitride permanent magnet material for EVs and renewable power generators. This new material, comprised entirely of low-cost and abundant resources, has the potential to demonstrate the highest energy potential of any magnet to date. This project will provide the basis for an entirely new class of rare-earth-free magnets capable of generating power without costly and scarce rare earth materials. The ultimate goal of this project is to demonstrate a prototype with magnetic properties exceeding state-of-the-art commercial magnets.

  9. Magnets & Magnet Condensed Matter Science

    E-Print Network [OSTI]

    McQuade, D. Tyler

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

  10. 3D magnetic inversion for total magnetization in areas with complicated remanence Peter G. Leli`evre*, Douglas W. Oldenburg and Nigel Phillips,

    E-Print Network [OSTI]

    Oldenburg, Douglas W.

    this problem we design a methodology for inverting magnetic data for subsurface magnetization, as opposed to magnetic susceptibility. Our approach contains flexibility to obtain different types of magnetization3D magnetic inversion for total magnetization in areas with complicated remanence Peter G. Leli

  11. GUIDELINES AND INFORMATION REGARDING THE TENURE, PERMANENT STATUS AND PROMOTION PROCESS FOR 2010-2011

    E-Print Network [OSTI]

    Roy, Subrata

    1 GUIDELINES AND INFORMATION REGARDING THE TENURE, PERMANENT STATUS AND PROMOTION PROCESS FOR 2010. Eligibility for Tenure and Permanent Status III. Procedures IV. Additional Information for Chairs and Directors V. Additional Information for College Committees and Deans VI. Preparing the Packets: Guidelines

  12. Tenure/Permanent Status Timeline (after the March 2013 regulation change)

    E-Print Network [OSTI]

    Watson, Craig A.

    year. The tenure/permanent status Third-Year packet is submitted to IFAS Human Resources in the summer of the third academic year. The tenure/permanent status packet is submitted to IFAS Human Resources no later the following July 1. DATE OF HIRE YEAR TO YEAR TO YEAR T/PS SUBMIT SUBMIT GRANTED THIRD-YEAR T/PS PACKET (JULY

  13. Creating Permanent Test Collections of Web Pages for Information Extraction Research*

    E-Print Network [OSTI]

    Gatterbauer, Wolfgang

    Creating Permanent Test Collections of Web Pages for Information Extraction Research* Bernhard information extraction, there is a need for permanent and annotated web page collections enabling objective sharable web page collections is not trivial nowadays because of the dynamic and diverse nature of modern

  14. Permanent shadow in simple craters near the lunar poles D. Ben J. Bussey,1

    E-Print Network [OSTI]

    Spudis, Paul D.

    Permanent shadow in simple craters near the lunar poles D. Ben J. Bussey,1 Paul G. Lucey,1 Donovan, 7500 km2 and 6500 km2 , for the north and south pole respectively. These values were obtained, to investigate the size and latitudinal extent of permanently shadowed regions near the lunar poles. Craters

  15. Geometry Dependence of Magnetization Reversal in Nanocomposite Alloys

    SciTech Connect (OSTI)

    Skomski, Ralph; Manchanda, Priyanka; Takeuchi, Ichiro; Cui, Jun

    2014-06-11

    The geometrical optimization of aligned hard-soft permanent-magnet nanocomposites is investigated by model calculations. Considered criteria are the shapes of the soft and c-axis-aligned hard phases, the packing fraction of the soft phase, and magnetostatic interactions. Taking into account that the energy product is enhanced via the volume fraction of the soft phase, subject to maintaining coercivity, we find that the best structures are soft-magnetic cubes as well as long rods with a square cross section. Comparing embedded soft cubes with embedded soft spheres of the same size, our nucleation-field analysis shows that the volume fraction of the soft phase is enhanced by 91%, with a coercivity reduction of only 25%. Magnetostatic interactions often but not always deteriorate the permanent-magnet performance, as exemplified by the example of MnBi:FeCo bilayers and multilayers.

  16. Refrigerator Magnets It seems that, these days, the home refrigerator was invented primarily as a venue for displaying

    E-Print Network [OSTI]

    Lü, James Jian-Qiang

    of these magnets (I will call them type A), the magnetic force problem we need to solve involves only the magnet and the steel skin of the refrigerator door. The second kind of magnet (I will call it type B) has an additional includes all three components. For both types of configurations we will assume that the magnetization

  17. Superconducting magnets

    SciTech Connect (OSTI)

    Not Available

    1994-08-01

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

  18. 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.

  19. Thermodynamic properties of a magnetically modulated graphene

    E-Print Network [OSTI]

    SK Firoz Islam; Naveen K. Singh; Tarun Kanti Ghosh

    2011-09-12

    The effect of magnetic modulation on thermodynamic properties of a graphene monolayer in presence of a constant perpendicular magnetic field is reported here. One-dimensional spatial electric or magnetic modulation lifts the degeneracy of the Landau levels and converts into bands and their band width oscillates with magnetic field leading to Weiss-type oscillation in the thermodynamic properties. The effect of magnetic modulation on thermodynamic properties of a graphene sheet is studied and then compared with electrically modulated graphene and magnetically modulated conventional two-dimensional electron gas (2DEG). We observe Weiss-type and de Haas-van Alphen (dHvA) oscillations at low and high magnetic field, respectively. There is a definite phase difference in Weiss-type oscillations in thermodynamic quantities of magnetically modulated graphene in compare to electrically modulated graphene. On the other hand, the phase remains same and amplitude of the oscillation is large when compared with the magnetically modulated 2DEG. Explicit asymptotic expressions of density of states and the Helmholtz free energy are provided to understand the phase and amplitude of the Weiss-type oscillations qualitatively. We also study thermodynamic properties when both electric and magnetic modulations are present. The Weiss-type oscillations still exist when the modulations are out-of-phase.

  20. 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.

  1. 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.

  2. 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.

  3. Magnetic shielding

    DOE Patents [OSTI]

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

    1987-01-01

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

  4. 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.

  5. Evaluation of the filler effects on fatique cracking and permanent deformation of asphalt concrete mixtures 

    E-Print Network [OSTI]

    Izzo, Richard P

    1997-01-01

    The addition of hydrated lime to asphalt has shown to be beneficial with an improvement in the Theological properties of the binder, as well as resistance to permanent deformation (rutting) and fatigue cracking of asphalt concrete mixtures...

  6. Factors affecting the permanence of livestock projects undertaken by Heifer International-Mexico 

    E-Print Network [OSTI]

    Arispe, Sergio Adrian

    2003-01-01

    in the state of Durango, Mexico. This study identified and analyzed the factors affecting the permanence of hog and dairy cow projects in four communities in the state of Durango, Mexico. The researcher interviewed seven project managers and 35 beneficiaries...

  7. 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 oilcontaining formations or saline aquifers. The term ?globule? refers to the water or liquid carbon dioxide droplets sheathed with ultrafine particles dispersed in the continuous external medium, liquid CO{sub 2} or H{sub 2}O, respectively. The key to obtaining very small globules is the shear force acting on the two intermixing fluids, and the use of ultrafine stabilizing particles or nanoparticles. We found that using Kenics-type static mixers with a shear rate in the range of 2700 to 9800 s{sup -1} and nanoparticles between 100-300 nm produced globule sizes in the 10 to 20 ?m range. Particle stabilized emulsions with that kind of globule size should easily penetrate oil-bearing formations or saline aquifers where the pore and throat size can be on the order of 50 ?m or larger. Subsequent research focused on creating particle stabilized emulsions that are deemed particularly suitable for Permanent Sequestration of Carbon Dioxide. Based on a survey of the literature an emulsion consisting of 70% by volume of water, 30% by volume of liquid or supercritical carbon dioxide, and 2% by weight of finely pulverized limestone (CaCO{sub 3}) was selected as the most promising agent for permanent sequestration of CO{sub 2}. In order to assure penetration of the emulsion into tight formations of sandstone or other silicate rocks and carbonate or dolomite rock, it is necessary to use an emulsion consisting of the smallest possible globule size. In previous reports we described a high shear static mixer that can create such small globules. In addition to the high shear mixer, it is also necessary that the emulsion stabilizing particles be in the submicron size, preferably in the range of 0.1 to 0.2 ?m (100 to 200 nm) size. We found a commercial source of such pulverized limestone particles, in addition we purchased under this DOE Project a particle grinding apparatus that can provide particles in the desired size range. Additional work focused on attempts to generate particle stabilized emulsions with a flow through, static mixer based apparatus under a variety

  8. 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.

  9. 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.

  10. Reduced electron temperature in a magnetized inductively-coupled plasma with internal coil

    SciTech Connect (OSTI)

    Arancibia Monreal, J.; Chabert, P. [LPP, CNRS, Ecole Polytechnique, UPMC, Paris XI, 91128 Palaiseau (France)] [LPP, CNRS, Ecole Polytechnique, UPMC, Paris XI, 91128 Palaiseau (France); Godyak, V. [RF Plasma Consulting, Brookline, Massachusetts 02446 (United States) [RF Plasma Consulting, Brookline, Massachusetts 02446 (United States); Michigan Institute for Plasma Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2013-10-15

    The effect of magnetic filtering on the electron energy distribution function is studied in an inductive discharge with internal coil coupling. The coil is placed inside the plasma and driven by a low-frequency power supply (5.8 MHz) which leads to a very high power transfer efficiency. A permanent dipole magnet may be placed inside the internal coil to produce a static magnetic field around 100 Gauss. The coil and the matching system are designed to minimize the capacitive coupling to the plasma. Capacitive coupling is quantified by measuring the radiofrequency (rf) plasma potential with a capacitive probe. Without the permanent magnet, the rf plasma potential is significantly smaller than the electron temperature. When the magnet is present, the rf plasma potential increases. The electron energy distribution function is measured as a function of space with and without the permanent magnet. When the magnet is present, electrons are cooled down to low temperature in the downstream region. This region of low electron temperature may be useful for plasma processing applications, as well as for efficient negative ion production.

  11. Magnetic nanotubes

    DOE Patents [OSTI]

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

    2010-11-16

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

  12. 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 and Sr occupy the same site. Oxygens are in the corner of polyhedra. - Highlights: • Structural phase changes at high temperatures. • Ordered distribution of oxygen vacancies below 573 K. • Double Perovskite type structure below 373 K in the P4/mmm space group. • Structural changes have direct correlation with conductivity. • Low area specific resistance at 973 K.

  13. Materials with low DC magnetic susceptibility for sensitive magnetic measurements

    E-Print Network [OSTI]

    Khatiwada, Rakshya; Kendrick, Rachel; Khosravi, Marjan; Peters, Michael; Smith, Erick; Snow, Mike

    2015-01-01

    Materials with very low DC magnetic susceptibility have many scientific applications. To our knowledge however, relatively little research has been conducted with the goal to produce a totally nonmagnetic material. This phrase in our case means after spatially averaging over macroscopic volumes, it possesses an average zero DC magnetic susceptibility. We report measurements of the DC magnetic susceptibility of three different types of nonmagnetic materials at room temperature: (I) solutions of paramagnetic salts and diamagnetic liquids, (II) liquid gallium-indium alloys and (III) pressed powder mixtures of tungsten and bismuth. The lowest measured magnetic susceptibility among these candidate materials is in the order of 10^-9 cgs volume susceptibility units, about two orders of magnitude smaller than distilled water. In all cases, the measured concentration dependence of the magnetic susceptibility is consistent with that expected for the weighted sum of the susceptibilities of the separate components within...

  14. Development of vortex state in circular magnetic nanodots: Theory and experiment RID A-9247-2009 

    E-Print Network [OSTI]

    Mejia-Lopez, J.; Altbir, D.; Landeros, P.; Escrig, J.; Romero, A. H.; Roshchin, Igor V.; Li, C-P; Fitzsimmons, M. R.; Batlle, X.; Schuller, Ivan K.

    2010-01-01

    in a variety of spintronics and magnetic storage applications, including magnetic bit- patterned media and magnetic random access memory. One of the most studied types of such structures are nanoscaled disks denoted as ?nanodots? which have been...

  15. Arthur W. Mahoney Curriculum Vitae Information

    E-Print Network [OSTI]

    and J. Abbott, "Generating Rotating Magnetic Fields with a Single Permanent Magnet for Propulsion and J. Abbott, "5-DOF Manipulation of an Untethered Magnetic Device in Fluid using a Single Permanent discharge machining of NdFeB permanent magnets with an RC-type machine," Journal of Materials Engineering

  16. 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.

  17. Dynamically stable magnetic suspension/bearing system

    DOE Patents [OSTI]

    Post, Richard F. (Walnut Creek, CA)

    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.

  18. Magnetic Properties of Mesoporous and Nano-particulate Metal Oxides 

    E-Print Network [OSTI]

    Hill, Adrian H

    2009-01-01

    The magnetic properties of the first row transition metal oxides are wide and varied and have been studied extensively since the 1930’s. Observations that the magnetic properties of these material types change with the ...

  19. 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 curve information, as well as temperature gradient history both in the solidifying metal and within the mold are invariably required to be validated. This validation depends upon the response of the sensor concerned, but also on its own effect upon the thermal environment. A joint university/industry team has completed an investigation of the invasive effects of thermocouples upon temperature history in permanent molds determining the degree of uncertainty associated with placement and indicating how the time-temperature history may be recovered. In addition to its relevance to the all important study of thermal contact of the casting with metallic molds, the observations also impact the determination of heat flux and interfacial heat transfer coefficients. In these respects the study represents the first of its kind that has tackled the problem in depth for permanent mold castings. An important ramification of this investigation has been the errors likely to be encountered in mold temperature measurement with thin section aluminum castings, especially with respect to the plans for thermocouple placement. A comparison between the degree of uncertainty experienced in sand molds compared with that found in permanent molds reveals that the associated problems have a lesser impact. These conclusions and the related recommendations have been disseminated to industry and the technical community through project reports and publications.

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

    SciTech Connect (OSTI)

    Agarwal, Shilpi, E-mail: sipi.agarwal@gmail.com, E-mail: manojklakra@gmail.com, E-mail: cshakher@iddc.iitd.ac.in; Kumar, Manoj, E-mail: sipi.agarwal@gmail.com, E-mail: manojklakra@gmail.com, E-mail: cshakher@iddc.iitd.ac.in; Shakher, Chandra, E-mail: sipi.agarwal@gmail.com, E-mail: manojklakra@gmail.com, E-mail: cshakher@iddc.iitd.ac.in [Instrument Design Development Centre, Indian Institute of Technology Delhi, HauzKhas, New Delhi - 110016 (India)

    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.

  1. Direct measurement of the impulse in a magnetic thrust chamber system for laser fusion rocket

    SciTech Connect (OSTI)

    Maeno, Akihiro; Yamamoto, Naoji; Nakashima, Hideki [Interdisciplinary Graduate School of Engineering Science, Kyushu University, 6-1 Kasuga-kouen, Kasuga, Fukuoka 816-8580 (Japan); Fujioka, Shinsuke; Johzaki, Tomoyuki [Institute of Laser Engineering, Osaka University, Suita, Osaka 565-087 (Japan); Mori, Yoshitaka [Graduate School for the Creation of New Photonics Industries, Hamamatsu, Shizuoka 431-1202 (Japan); Sunahara, Atsushi [Institute for Laser Technology, Suita, Osaka 565-087 (Japan)

    2011-08-15

    An experiment is conducted to measure an impulse for demonstrating a magnetic thrust chamber system for laser fusion rocket. The impulse is produced by the interaction between plasma and magnetic field. In the experiment, the system consists of plasma and neodymium permanent magnets. The plasma is created by a single-beam laser aiming at a polystyrene spherical target. The impulse is 1.5 to 2.2 {mu}Ns by means of a pendulum thrust stand, when the laser energy is 0.7 J. Without magnetic field, the measured impulse is found to be zero. These results indicate that the system for generating impulse is working.

  2. 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.

  3. 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.

  4. 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.

  5. Conditioning of spent nuclear fuel for permanent disposal

    SciTech Connect (OSTI)

    Laidler, J.J.

    1994-10-01

    A compact, efficient method for conditioning spent nuclear fuel is under development This method, known as pyrochemical processing, or {open_quotes}pyroprocessing,{close_quotes} provides a separation of fission products from the actinide elements present in spent fuel and further separates pure uranium from the transuranic elements. The process can facilitate the timely and environmentally-sound treatment of the highly diverse collection of spent fuel currently in the inventory of the United States Department of Energy (DOE). The pyroprocess utilizes elevated-temperature processes to prepare spent fuel for fission product separation; that separation is accomplished by a molten salt electrorefining step that provides efficient (99.9%) separation of transuranics. The resultant waste forms from the pyroprocess are stable under envisioned repository environment conditions and highly leach-resistant. Treatment of any spent fuel type produces a set of common high-level waste forms, one a mineral and the other a metal alloy, that can be readily qualified for repository disposal and preclude the substantial costs that would be associated with the qualification of the numerous spent fuel types included in the DOE inventory.

  6. DESIGN STUDY OF THE DIPOLE MAGNET FOR THE RHIC EBIS HIGH ENERGY TRANSPORT LINE

    E-Print Network [OSTI]

    DESIGN The bending section in EBIS HEBT line consists of two identical H type magnets with a slit betweenDESIGN STUDY OF THE DIPOLE MAGNET FOR THE RHIC EBIS HIGH ENERGY TRANSPORT LINE Takeshi Kanesue magnet body should be laminated. In this paper, design methods of the dipole magnet to optimize magnetic

  7. Visa Type Alien Number (If Applicable) FPd Which of the following categories best describes you? Response is voluntary. See notes on reverse side for explanation.

    E-Print Network [OSTI]

    Qiu, Weigang

    COLLEGE USE ONLY DIV FEE GRPADM CURRICULUM RESIDENCY STP YR MO Visa Type Alien Number (If of application . 3. Permanent residents of the United States will be required to present their Alien Registration

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

    SciTech Connect (OSTI)

    Buchenau, D., E-mail: d.buchenau@hzdr.de; Galindo, V.; Eckert, S. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics, Bautzner Landstraße 400, 01328 Dresden (Germany)

    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.

  9. Top DIUS official moves to the Football Association Ian Watmore, permanent secretary at the Department for Innovation, Universities and Skills,

    E-Print Network [OSTI]

    Crowther, Paul

    Top DIUS official moves to the Football Association Ian Watmore, permanent secretary Football Association. At the FA, Watmore will be reunited with David Triesman, the FA's chairman, who

  10. FLUXCAP: A flux-coupled ac/dc magnetizing device

    E-Print Network [OSTI]

    Gopman, Daniel B; Kent, Andrew D

    2012-01-01

    We report on an instrument for applying ac and dc magnetic fields by capturing the flux from a rotating permanent magnet and projecting it between two adjustable pole pieces. This can be an alternative to standard electromagnets for experiments with small samples or in probe stations in which an applied magnetic field is needed locally, with advantages that include a compact form-factor, very low power requirements and dissipation as well as fast field sweep rates. This flux capture instrument (FLUXCAP) can produce fields from -400 to +400 mT, with field resolution less than 1 mT. It generates static magnetic fields as well as ramped fields, with ramping rates as high as 10 T/s. We demonstrate the use of this apparatus for studying the magnetotransport properties of spin-valve nanopillars, a nanoscale device that exhibits giant magnetoresistance.

  11. Scaling of Superconducting Switches for Extraction of Magnetic Energy

    E-Print Network [OSTI]

    Ballarino, A

    2010-01-01

    In certain cases it is necessary to extract the energy from a superconducting magnet when it quenches, in order to limit the heat generated by the event and thus prevent irreversible damage. This is usually achieved by opening a contact breaker across a resistor in the circuit feeding the magnet. For the heavy currents used to excite large magnets such switches incorporate sophisticated devices to limit arcing during the operation; besides being quite large and expensive, such switches have a limited lifetime. It is therefore interesting to consider the use of superconducting switches to perform this function, the advantage being that such switches would (i) not require maintenance and (ii) would be housed within the cryogenic environment of the magnet, and thus avoid permanent diversion of the current in and out of that environment to the mechanical switch (which operates at room temperature). However, practical switches for such an application are made up of superconductor in a metal matrix, and it is conve...

  12. Magnet Cable Manufacturing

    E-Print Network [OSTI]

    Royet, J.M.

    2011-01-01

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

  13. 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 core—coupling 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.

  14. Magnetic Stereoscopy

    E-Print Network [OSTI]

    Thomas Wiegelmann; Bernd Inhester

    2006-12-21

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

  15. Job Posting-Jan 7, 2014, 4:38:58 PM Job Type-Full time permanent

    E-Print Network [OSTI]

    New Hampshire, University of

    · Robotics & Vision Systems· 6 Sigma, Lean, TPM· Advanced computer skills in Excel, Minitab, Infinity, SAP automated systems. They will be actively involved in all aspects of the many automated processes used to produce ceramic components for use in lighting products. Some projects will require working independently

  16. AN ISSUE OF PERMANENCE: ASSESSING THE EFFECTIVENESS OF TEMPORARY CARBON STORAGE

    E-Print Network [OSTI]

    AN ISSUE OF PERMANENCE: ASSESSING THE EFFECTIVENESS OF TEMPORARY CARBON STORAGE HOWARD HERZOG1, KEN of temporary storage?' Valuing temporary storage can be represented as a familiar economic problem a fixed cumulative emissions limit and there is no backstop, then a storage option with even very slow

  17. Optimal drug release schedule for in-situ radiosensitization of image guided permanent prostate implants

    E-Print Network [OSTI]

    Sridhar, Srinivas

    of image guided 125 I prostate brachytherapy. Spacers used in permanent implants may be manufactured from such a constraint, is not known. This work determines the optimal elution schedules for 125 I prostate brachytherapy. The interaction between brachytherapy dose distributions and drug distribution around drug eluting spacers

  18. MONITORING TIANJIN SUBSIDENCE WITH THE PERMANENT SCATTERERS Dr. Daniele Perissin(1)

    E-Print Network [OSTI]

    Perissin, Daniele

    MONITORING TIANJIN SUBSIDENCE WITH THE PERMANENT SCATTERERS TECHNIQUE Dr. Daniele Perissin(1) , Dr 34/5, 20133 Milano, Italy 1. ABSTRACT Many urban areas in China are affected by land subsidence the area around Tianjin city in the Popular Republic of China, where a subsidence at the present time

  19. Fluorescence Microscopy Evidence for Quasi-Permanent Attachment of Antifreeze Proteins to Ice Surfaces

    E-Print Network [OSTI]

    Wettlaufer, John S.

    Fluorescence Microscopy Evidence for Quasi-Permanent Attachment of Antifreeze Proteins to Ice ABSTRACT Many organisms are protected from freezing by the presence of extracellular antifreeze proteins (AFPs), which bind to ice, modify its morphology, and prevent its further growth. These proteins have

  20. The WIPP is the nation's first geologic facility designed for permanent disposal of transuranic

    E-Print Network [OSTI]

    The WIPP is the nation's first geologic facility designed for permanent disposal of transuranic, New Mexico to dispose of this waste. The TRU waste being disposed at the WIPP is packaged into drums-level waste and spent nuclear fuel. The WIPP has a total capacity of 6.2 million cubic feet of TRU waste

  1. 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.”

  2. 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.

  3. Examples of the Generalized Quantum Permanent Compromise Attack to the Blum-Micali Construction

    E-Print Network [OSTI]

    Guedes, Elloá B; Lula, Bernardo

    2010-01-01

    This paper presents examples of the quantum permanent compromise attack to the Blum-Micali construction. Such attacks illustrate how a previous attack to the Blum-Micali generator can be extended to the whole Blum-Micali construction, including the Blum-Blum-Shub and Kaliski generators.

  4. Phoenix: Detecting and Recovering from Permanent Processor Design Bugs with Programmable Hardware

    E-Print Network [OSTI]

    Torrellas, Josep

    Phoenix: Detecting and Recovering from Permanent Processor Design Bugs with Programmable Hardware, and Motorola processors, this paper proposes and evalu- ates Phoenix -- novel field-programmable on-chip hardware that de- tects and recovers from design defects. Phoenix taps key logic signals and, based

  5. Microsymposium 34, MS065, 2001 PERMANENTLY SHADOWED AREAS AT THE LUNAR POLES. V. V. Shevchenko1

    E-Print Network [OSTI]

    Shevchenko, Vladislav

    Microsymposium 34, MS065, 2001 PERMANENTLY SHADOWED AREAS AT THE LUNAR POLES. V. V. Shevchenko1 , E a maximum of 1,95° above the horizon at the lunar poles. Therefore topographic depressions near the lunar poles may contain water ice deposits. We have used the Morphological catalogue of the craters

  6. ''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.

  7. Interfacial deformation and jetting of a magnetic fluid

    E-Print Network [OSTI]

    Afkhami, Shahriar; Griffiths, Ian M

    2015-01-01

    An attractive technique for forming and collecting aggregates of magnetic material at a liquid--air interface by an applied magnetic field gradient was recently addressed theoretically and experimentally [Soft Matter, (9) 2013, 8600-8608]: when the magnetic field is weak, the deflection of the liquid--air interface has a steady shape, while for sufficiently strong fields, the interface destabilizes and forms a jet that extracts magnetic material. Motivated by this work, we develop a numerical model for the closely related problem of solving two-phase Navier--Stokes equations coupled with the static Maxwell equations. We computationally model the forces generated by a magnetic field gradient produced by a permanent magnet and so determine the interfacial deflection of a magnetic fluid (a pure ferrofluid system) and the transition into a jet. We analyze the shape of the liquid--air interface during the deformation stage and the critical magnet distance for which the static interface transitions into a jet. We d...

  8. Magnetic reconnection configurations and particle acceleration in solar flares

    E-Print Network [OSTI]

    Chen, P. F.

    types of solar flares. Upper panel: two-ribbon flares; Lower panel: compact flares. The color showsMagnetic reconnection configurations and particle acceleration in solar flares P. F. Chen, W. J space under different magnetic configurations. Key words: solar flares, magnetic reconnection, particle

  9. Magnetic Channeling of Radiatively Driven Hot-Star Winds

    E-Print Network [OSTI]

    Owocki, Stanley P.

    in magnetic Bp stars like sigma Ori C. We conclude with an outlook for the general role of magnetic fields that of the solar wind. Their high surface temperatures mean that such stars lack the hydrogen recombination convection zone that induces the magnetic dynamo cycle of cooler, solar type stars [e.g., 3]. Such stars have

  10. ON THE INTERACTION BETWEEN CONVECTION AND MAGNETIC FIELDS Fausto Cattaneo

    E-Print Network [OSTI]

    Emonet, Thierry

    found in these different regimes are described and analyzed. Subject headings: convection -- Sun: magnetic fields -- Sun: photosphere 1. INTRODUCTION Magnetic activity is exhibited by late-type stars with deep convective envelopes, but the fine structure of the magnetic field can only be detected on the Sun

  11. Blood Types

    E-Print Network [OSTI]

    Hacker, Randi; Tsutsui, William

    2007-03-14

    Sox spent a hundred mil to acquire pitcher Daisuke Matsuzaka; they probably weren't even aware that he is a Type O and that they make the best bankers, politicians and... you guessed it... professional baseball players. #ceas #hacker #japan #tsutsuien...

  12. 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.).

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

    DOE Patents [OSTI]

    Humphries, David E. (El Cerrito, CA); Hong, Seok-Cheol (Seoul, KR); Cozzarelli, legal representative, Linda A. (Berkeley, CA); Pollard, Martin J. (El Cerrito, CA); Cozzarelli, Nicholas R. (Berkeley, CA)

    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.

  14. 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. While a route to increased coercivity wasmore »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

  15. Abstract--This paper presents an analysis by which the dynamic performances of a permanent magnet synchronous

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -generation electricity has fallen steadily. Wind turbines in USA produce about 1% of total generation [1]. Also, wind of increasing environmental concern, more and more electricity is generated from renewable energy. The main advantage of electricity generation from renewable sources is the absence of harmful emission

  16. A microprocessor-based control to improve the high speed performance of a permanent magnet brushless motor 

    E-Print Network [OSTI]

    Becerra, Roger Carlos

    1986-01-01

    -state performance variables, each simulation is allowed to proceed until all of transient modes sufficiently decay. Rotor speed is held constant throughout each simulation. 120 ase e . 7Raase !Weg. Phase 361etL. 90 O 30 200 360 520 680 Speed (rpg) 840... rare earth mag- nets and advanced motor design and manufacturing techniques have stimulated a surge of interest in the development and applications of PM brushless motors. The implementation of a method of converter control to improve the high speed...

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

    SciTech Connect (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.

  19. Design and performance evaluation of an electric go-kart and custom permanent magnet brushless DC motor

    E-Print Network [OSTI]

    Davis, Eli Marc

    2012-01-01

    This undergraduate thesis documents the design considerations and specifications of building a personal battery-powered go-kart. This includes designing and building a custom brushless DC motor for use in the drivetrain. ...

  20. 0-7803-9280-9/05/$20.00 2005 IEEE. 603 Design of a High-Speed Permanent Magnet Motor

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    and developments have been done in order to achieve industrial systems for both stationary and mobile applications to maintain gas and membrane hydration; - the cooling circuit, to extract the heat produced during of the pumps, compressors... must be provided by the stack and it can represent up to 40 % of the produced

  1. 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...

  2. Permanent Magnet Assisted Synchronous Reluctance Machine (PMa-SynRM) Design and Performance Analysis for Fan and Pump Applications 

    E-Print Network [OSTI]

    Vartanian, Robert

    2014-08-13

    .................................................................................................... 28 IIIB. Design Criteria ................................................................................................ 30 IIIB1. Torque Performance ............................................................................ 30 IIIB2. Back-EMF... ....................................................... 53 IIIG1. Back-EMF Measurement .................................................................... 55 IIIH. Skew Effect on PMa-SynRM NdFeB ............................................................ 59 IIIH1. Effect of Skewing on Cogging Torque...

  3. Magnetic Reconnection

    SciTech Connect (OSTI)

    Masaaki Yamada, Russell Kulsrud and Hantao Ji

    2009-09-17

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

  4. Magnetic domain structures of focused ion beam-patterned cobalt films using scanning ion microscopy with polarization analysis

    E-Print Network [OSTI]

    Rau, Carl

    in the areas of ultrahigh density magnetic recording, MRAM design, and miniaturized magnetic sensor arrays, it is found that rectangular Co bars of sizes between 10­30 m exhibit S type, whereas circular shaped magnetic elements show C type micromagnetic magnetization patterns. It is shown that SIMPA provides a simple way

  5. Patterned Magnetic Nanostructures and Quantized Magnetic Disks

    E-Print Network [OSTI]

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

  6. 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.

  7. Measuring Magnetic Fields in the Solar Atmosphere

    E-Print Network [OSTI]

    de Wijn, A G

    2012-01-01

    Since the discovery by Hale in the early 1900s that sunspots harbor strong magnetic field, magnetism has become increasingly important in our understanding of processes on the Sun and in the Heliosphere. Many current and planned instruments are capable of diagnosing magnetic field in the solar atmosphere. Photospheric magnetometry is now well-established. However, many challenges remain. For instance, the diagnosis of magnetic field in the chromosphere and corona is difficult, and interpretation of measurements is harder still. As a result only very few measurements have been made so far, yet it is clear that if we are to understand the outer solar atmosphere we must study the magnetic field. I will review the history of solar magnetic field measurements, describe and discuss the three types of magnetometry, and close with an outlook on the future.

  8. Materials with low DC magnetic susceptibility for sensitive magnetic measurements

    E-Print Network [OSTI]

    Rakshya Khatiwada; Lawrence Dennis; Rachel Kendrick; Marjan Khosravi; Michael Peters; Erick Smith; Mike Snow

    2015-06-30

    Materials with very low DC magnetic susceptibility have many scientific applications. To our knowledge however, relatively little research has been conducted with the goal to produce a totally nonmagnetic material. This phrase in our case means after spatially averaging over macroscopic volumes, it possesses an average zero DC magnetic susceptibility. We report measurements of the DC magnetic susceptibility of three different types of nonmagnetic materials at room temperature: (I) solutions of paramagnetic salts and diamagnetic liquids, (II) liquid gallium-indium alloys and (III) pressed powder mixtures of tungsten and bismuth. The lowest measured magnetic susceptibility among these candidate materials is in the order of 10^-9 cgs volume susceptibility units, about two orders of magnitude smaller than distilled water. In all cases, the measured concentration dependence of the magnetic susceptibility is consistent with that expected for the weighted sum of the susceptibilities of the separate components within experimental error. These results verify the Wiedemann additivity law and thereby realize the ability to produce materials with small but tunable magnetic susceptibility. For our particular scientific application, we are also looking for materials with the largest possible number of neutrons and protons per unit volume. The gallium-indium alloys fabricated and measured in this work possess to our knowledge the smallest ratio of volume magnetic susceptibility to nucleon number density per unit volume for a room temperature liquid, and the tungsten-bismuth pressed powder mixtures possess to our knowledge the smallest ratio of volume magnetic susceptibility to nucleon number density per unit volume for a room temperature solid. This ratio is a figure of merit for a certain class of precision experiments that search for possible exotic spin-dependent forces of Nature.

  9. MAGNETIC FLUX LEAKAGE INVESTIGATION OF INTERACTING DEFECTS: COMPETITIVE EFFECTS OF STRESS CONCENTRATION AND MAGNETIC SHIELDING

    E-Print Network [OSTI]

    Clapham, Lynann

    CONCENTRATION AND MAGNETIC SHIELDING C Mandache1,2 and L Clapham1 1 Queen's University, Kingston, Ontario, K7L 3 of their stress concentrations and by the mutual shielding of the defects from the applied flux density. This type and magnetic flux shielding further complicates the defect-induced MFL signal calibration [6]. The focus

  10. Derived Types What Are Derived Types?

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    Derived Types #12;What Are Derived Types? As usual, a hybrid of two, unrelated concepts C++, Python orientation comes in #12;Simple Derived Types TYPE Wheel INTEGER :: spokes REAL :: diameter, width CHARACTER(LEN=15) :: material END TYPE Wheel That defines a derived type Wheel Using derived types needs a special

  11. Derived Types What Are Derived Types?

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    Derived Types #12;What Are Derived Types? As usual, a hybrid of two, unrelated concepts C object orientation comes in This course will only describe the former. #12;Simple Derived Types TYPE That defines a derived type Wheel Using derived types needs a special syntax TYPE(Wheel) :: w1 #12;More

  12. Laboratory Plasma Dynamos, Astrophysical Dynamos, and Magnetic Helicity Evolution

    E-Print Network [OSTI]

    Blackman, E G; Blackman, Eric G.; Ji, Hantao

    2006-01-01

    The term ``dynamo'' means different things to the laboratory fusion plasma and astrophysical plasma communities. To alleviate the resulting confusion and to facilitate interdisciplinary progress, we pinpoint conceptual differences and similarities between laboratory plasma dynamos and astrophysical dynamos. We can divide dynamos into three types: 1. magnetically dominated helical dynamos which sustain a large scale magnetic field against resistive decay and drive the magnetic geometry toward the lowest energy state, 2. flow-driven helical dynamos which amplify or sustain large scale magnetic fields in an otherwise turbulent flow, and 3. flow-driven nonhelical dynamos which amplify fields on scales at or below the driving turbulence. We discuss how all three types occur in astrophysics whereas plasma confinement device dynamos are of the first type. Type 3 dynamos requires no magnetic or kinetic helicity of any kind. Focusing on type 1 and 2 dynamos, we show how different limits of a unified set of equations f...

  13. 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.

  14. Nematic order of model goethite nanorods in a magnetic field

    E-Print Network [OSTI]

    H. H. Wensink; G. J. Vroege

    2005-01-18

    We explore the nematic order of model goethite nanorods in an external magnetic field within Onsager-Parsons density functional theory. The goethite rods are represented by monodisperse, charged spherocylinders with a permanent magnetic moment along the rod main axis, forcing the particles to align parallel to the magnetic field at low field strength. The intrinsic diamagnetic susceptibility anisometry of the rods is negative which leads to a preferred perpendicular orientation at higher field strength. It is shown that these counteracting effects may give rise to intricate phase behavior, including a pronounced stability of biaxial nematic order and the presence of reentrant phase transitions and demixing phenomena. The effect of the applied field on the nematic-to-smectic transition will also be addressed.

  15. 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.

  16. Superconducting wiggler magnets for beam-emittance damping rings

    E-Print Network [OSTI]

    Schoerling, Daniel

    2012-01-01

    Ultra-low emittance beams with a high bunch charge are necessary for the luminosity performance of linear electron-positron colliders, such as the Compact Linear Collider (CLIC). An effective way to create ultra-low emittance beams with a high bunch charge is to use damping rings, or storage rings equipped with strong damping wiggler magnets. The remanent field of the permanent magnet materials and the ohmic losses in normal conductors limit the economically achievable pole field in accelerator magnets operated at around room temperature to below the magnetic saturation induction, which is 2.15 T for iron. In wiggler magnets, the pole field in the center of the gap is reduced further like the hyperbolic cosine of the ratio of the gap size and the period length multiplied by pi. Moreover, damping wiggler magnets require relatively large gaps because they have to accept the un-damped beam and to generate, at a small period length, a large magnetic flux density amplitude to effectively damp the beam emittance....

  17. Type: Renewal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsStateof Energy TwoEvent at the Pu Facility,Type IV COPV1

  18. 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.

  19. A topological analysis of the magnetic breakout model for an eruptive solar flare

    E-Print Network [OSTI]

    Priest, Eric

    A topological analysis of the magnetic breakout model for an eruptive solar flare BY RHONA MACLEAN model gives an elegant explanation for the onset of an eruptive solar flare, involving magnetic types of bifurcation. Keywords: solar flare; magnetic breakout; magnetic topology; solar corona 1

  20. 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.

  1. DIRECT-DRIVE AND EDDY-CURRENT SEPTUM MAGNETS June 29, 2001

    E-Print Network [OSTI]

    Kemner, Ken

    DIRECT-DRIVE AND EDDY-CURRENT SEPTUM MAGNETS S. H. Kim June 29, 2001 Abstract -- Two types of thin septum magnets, direct drive and eddy current, were compared mainly in 2-D magnetic aspects. For the eddy-current type, the leakage fields calculated using OPERA-2d were compared with the calculations

  2. FROM CONSTANT TO NON-DEGENERATELY VANISHING MAGNETIC FIELDS IN SUPERCONDUCTIVITY

    E-Print Network [OSTI]

    the distribution of superconductivity in a type II superconductor submitted to a vari- able magnetic fieldFROM CONSTANT TO NON-DEGENERATELY VANISHING MAGNETIC FIELDS IN SUPERCONDUCTIVITY BERNARD HELFFER- tivity in a type II superconductor subjected to a constant magnetic field. The second function describes

  3. 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

  4. MAGNETIC FIELD MEASUREMENTS OF HD2, A HIgh Nb3Sn DIPOLE MAGNET

    SciTech Connect (OSTI)

    Wang, X.; Caspi, S.; Cheng, D. W.; Felice, H.; Ferracin, P.; Hafalia, R. R.; Joseph, J. M.; Lietzke, A. F.; Lizarazo, J.; McInturff, A. D.; Sabbi, G. L.; Sasaki, K.

    2009-05-04

    The Superconducting Magnet Program at Lawrence Berkeley National Laboratory has designed and tested HD2, a 1 m long Nb{sub 3}Sn accelerator-type dipole based on a simple block-type coil geometry with flared ends. HD2 represents a step toward the development of cost-effective accelerator quality magnets operating in the range of 13-15 T. The design was optimized to minimize geometric harmonics and to address iron saturation and conductor magnetization effects. Field quality was measured during recent cold tests. The measured harmonics are presented and compared to the design values.

  5. 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 heat exchangers or oil distribution issues found in traditional vapor compression systems.

  6. Nanostructured magnetic materials

    E-Print Network [OSTI]

    Chan, Keith T.

    2011-01-01

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

  7. Magnets and Power Supplies

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

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

  8. SUPERCONDUCTING MAGNETIC ENERGY STORAGE

    E-Print Network [OSTI]

    Hassenzahl, W.

    2011-01-01

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

  9. STUDY TYPES What is a "Study Type"?

    E-Print Network [OSTI]

    Dorf, Martin E.

    #12;STUDY TYPES What is a "Study Type"? A Study Type is a defined business process. Study Types work together to streamline workflow, track data & keep users informed. There are 2 Study Types in eCOMS: COMS and IACUC. The COMS Study: The COMS Study is an online form that a Principal Investigator fills

  10. Graphene Nanoribbon in Sharply Localized Magnetic Fields

    E-Print Network [OSTI]

    Abdulaziz D. Alhaidari; Hocine Bahlouli; Abderrahim El Mouhafid; Ahmed Jellal

    2013-03-20

    We study the effect of a sharply localized magnetic field on the electron transport in a strip (ribbon) of graphene sheet, which allows to give results for the transmission and reflection probability through magnetic barriers. The magnetic field is taken as a single and double delta type localized functions, which are treated later as the zero width limit of gaussian fields. For both field configurations, we evaluate analytically and numerically their transmission and reflection coefficients. The possibility of spacial confinement due to the inhomogeneous field configuration is also investigated.

  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. 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.

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

    DOE Patents [OSTI]

    Coffey, Howard T. (Darien, IL)

    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. Laboratory Plasma Dynamos, Astrophysical Dynamos, and Magnetic Helicity Evolution

    E-Print Network [OSTI]

    Eric G. Blackman; Hantao Ji

    2006-04-10

    The term ``dynamo'' means different things to the laboratory fusion plasma and astrophysical plasma communities. To alleviate the resulting confusion and to facilitate interdisciplinary progress, we pinpoint conceptual differences and similarities between laboratory plasma dynamos and astrophysical dynamos. We can divide dynamos into three types: 1. magnetically dominated helical dynamos which sustain a large scale magnetic field against resistive decay and drive the magnetic geometry toward the lowest energy state, 2. flow-driven helical dynamos which amplify or sustain large scale magnetic fields in an otherwise turbulent flow, and 3. flow-driven nonhelical dynamos which amplify fields on scales at or below the driving turbulence. We discuss how all three types occur in astrophysics whereas plasma confinement device dynamos are of the first type. Type 3 dynamos requires no magnetic or kinetic helicity of any kind. Focusing on type 1 and 2 dynamos, we show how different limits of a unified set of equations for magnetic helicity evolution reveal both types. We explicitly describe a steady-state example of a type 1 dynamo, and three examples of type 2 dynamos: (i) closed volume and time dependent; (ii) steady-state with open boundaries; (iii) time dependent with open boundaries.

  16. Longitudinal wave function control in single quantum dots with an applied magnetic field

    E-Print Network [OSTI]

    Shuo Cao; Jing Tang; Yunan Gao; Yue Sun; Kangsheng Qiu; Yanhui Zhao; Min He; Jin-An Shi; Lin Gu; David A. Williams; Weidong Sheng; Kuijuan Jin; Xiulai Xu

    2015-01-29

    Controlling single-particle wave functions in single semiconductor quantum dots is in demand to implement solid-state quantum information processing and spintronics. Normally, particle wave functions can be tuned transversely by an perpendicular magnetic field. We report a longitudinal wave function control in single quantum dots with a magnetic field. For a pure InAs quantum dot with a shape of pyramid or truncated pyramid, the hole wave function always occupies the base because of the less confinement at base, which induces a permanent dipole oriented from base to apex. With applying magnetic field along the base-apex direction, the hole wave function shrinks in the base plane. Because of the linear changing of the confinement for hole wave function from base to apex, the center of effective mass moves up during shrinking process. Due to the uniform confine potential for electrons, the center of effective mass of electrons does not move much, which results in a permanent dipole moment change and an inverted electron-hole alignment along the magnetic field direction. Manipulating the wave function longitudinally not only provides an alternative way to control the charge distribution with magnetic field but also a new method to tune electron-hole interaction in single quantum dots.

  17. Submitted to MT-15, Fifteenth International Conference on Magnet Technology, Beijing, China, October 20-24, 1997. Coldmass for LHC Dipole Insertion Magnets*

    E-Print Network [OSTI]

    Ohta, Shigemi

    designed with 2-in-1 coldmasses. In the design presented here, all magnets would be 2-in-1 type coldmasses and the expected field quality in 2-in-1 dipole magnets. A unique feature of this coldmass design is the use design and allows the LHC main dipole cryostat, post, etc., to be used in these magnets. The pro- posed

  18. Magnetic switch coupling to synchronize magnetic modulators

    DOE Patents [OSTI]

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

    1999-01-01

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

  19. 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.

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

    DOE Patents [OSTI]

    Huang, Yuhong (West Hills, CA); Wei, Qiang (West Hills, CA); Zheng, Haixing (Oak Park, CA)

    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.

  1. Theory of dissociative recombination of a linear triatomic ion with permanent electric dipole moment: Study of HCO$^{+}$

    E-Print Network [OSTI]

    Nicolas Douguet; Viatcheslav Kokoouline; Chris H. Greene

    2009-10-27

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

  2. Controlling Magnetism at the Nanoscale

    E-Print Network [OSTI]

    Wong, Jared

    2012-01-01

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

  3. Assignment Types UTS LIBRARY

    E-Print Network [OSTI]

    University of Technology, Sydney

    Assignment Types UTS LIBRARY February 2013 Academic Writing Guide Part 2 ­ Assignment Types: This section outlines the basic types of written assignments, providing structural elements and examples. #12;2 II. Assignment Types 1. Essay Writing

  4. Fast magnetization in counterstreaming plasmas with temperature anisotropies

    E-Print Network [OSTI]

    M. Lazar

    2007-11-15

    Counterstreaming plasmas exhibits an electromagnetic unstable mode of filamentation type, which is responsible for the magnetization of plasma system. It is shown that filamentation instability becomes significantly faster when plasma is hotter in the streaming direction. This is relevant for astrophysical sources, where strong magnetic fields are expected to exist and explain the nothermal emission observed.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Dipolar structures in magnetite ferrofluids studied with small-angle neutron scattering with and without applied magnetic field

    SciTech Connect (OSTI)

    Klokkenburg, M.; Erne, B. H.; Petukhov, A. V.; Philipse, A. P. [Van 't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht (Netherlands); Wiedenmann, A. [Hahn-Meitner-Institut Berlin, Department SF3, Glienickerstrasse 100, D-14109 Berlin (Germany)

    2007-05-15

    Field-induced structure formation in a ferrofluid with well-defined magnetite nanoparticles with a permanent magnetic dipole moment was studied with small-angle neutron scattering (SANS) as a function of the magnetic interactions. The interactions were tuned by adjusting the size of the well-defined, single-magnetic-domain magnetite (Fe{sub 3}O{sub 4}) particles and by applying an external magnetic field. For decreasing particle dipole moments, the data show a progressive distortion of the hexagonal symmetry, resulting from the formation of magnetic sheets. The SANS data show qualitative agreement with recent cryogenic transmission electron microscopy results obtained in 2D [Klokkenburg et al., Phys. Rev. Lett. 97, 185702 (2006)] on the same ferrofluids.

  12. Mechanism of magnetism in stacked nanographite with open shell electrons

    E-Print Network [OSTI]

    Kikuo Harigaya; Toshiaki Enoki

    2001-10-23

    Antiferromagnetism in stacked nanographite is investigated with using the Hubbard-type models. The A-B stacking or the stacking near to that of A-B type is favorable for the hexagonal nanographite with zigzag edges, in order that magnetism appears. Next, we find that the open shell electronic structure can be an origin of the decreasing magnetic moment with the decrease of the inter-graphene distance, as experiments on adsorption of molecules suggest.

  13. Magnetic Graphene Nanohole Superlattices

    E-Print Network [OSTI]

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

    2008-01-01

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

  14. Magnetic assisted statistical assembly

    E-Print Network [OSTI]

    Cheng, Diana I

    2008-01-01

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

  15. Radiation damage issues for superconducting magnet

    E-Print Network [OSTI]

    McDonald, Kirk

    and "RAL 71A", developed at RAL · What are the disadvantages? · Can have low radiation hardness so polymer dictates magnet lifetime #12;Known radiation dose limits for polymers Many factors influence rad ions and radicals Ideally we should consider more than just dose... Radiation types do have different

  16. A Typed Operational Semantics for Type Theory 

    E-Print Network [OSTI]

    Goguen, Healfdene

    Untyped reduction provides a natural operational semantics for type theory. Normalization results say that such a semantics is sound. However, this reduction does not take type information into account and gives no information ...

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

    DOE Patents [OSTI]

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

    1978-01-01

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

  18. Magnetic Fields Analogous to electric field, a magnet

    E-Print Network [OSTI]

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

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

  19. 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.

  20. 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.

  1. Metallic Magnetic Hetrostructures

    E-Print Network [OSTI]

    Leung, Chi Wah

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

  2. 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 (5–15?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.

  3. Resonances Width in Crossed Electric and Magnetic Christian Ferrari a and Hynek Kova r k b

    E-Print Network [OSTI]

    Resonances Width in Crossed Electric and Magnetic Fields Christian Ferrari a and Hynek Kova#20;r#19 con#12;ned to a two- dimensional plane and submitted to homogeneous magnetic and electric #12;elds dimensions in the presence of crossed magnetic and electric #12;elds and a potential type perturbation. We

  4. Formation of Sets and Subsets of Informative Features of Information Carriers with Magnetic Hard Disks*

    E-Print Network [OSTI]

    Borissova, Daniela

    . Regardless of the type of the information carrier with hard magnetic disks, the main and most important137 Formation of Sets and Subsets of Informative Features of Information Carriers with Magnetic magnetic disk, new informative features are presented, which form a substantial subset of the informative

  5. sedimentation under permanent ice cover in the Arc-tic Ocean. Cont. Shelf Res. 14: 279-293.

    E-Print Network [OSTI]

    390 Notes sedimentation under permanent ice cover in the Arc- tic Ocean. Cont. Shelf Res. 14: 279-293. HAWLEY, N. 1988. Flow in cylindrical sediment traps. J. Great Lakes Res. 14: 76-88. HOLM-HANSEN, O., C. J. Effectiveness of various treatments in retarding mi- crobial activity in sediment trap material

  6. Reduction of Magnetic Noise in Atom Chips by Material Optimization

    E-Print Network [OSTI]

    V. Dikovsky; Y. Japha; C. Henkel; R. Folman

    2005-06-05

    We discuss the contribution of the material type in metal wires to the electromagnetic fluctuations in magnetic microtraps close to the surface of an atom chip. We show that significant reduction of the magnetic noise can be achieved by replacing the pure noble metal wires with their dilute alloys. The alloy composition provides an additional degree of freedom which enables a controlled reduction of both magnetic noise and resistivity if the atom chip is cooled. In addition, we provide a careful re-analysis of the magnetically induced trap loss observed by Yu-Ju Lin et al. [Phys. Rev. Lett. 92, 050404 (2004)] and find good agreement with an improved theory.

  7. 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.

  8. The chiral magnetic nanomotors

    E-Print Network [OSTI]

    Morozov, Konstantin I

    2013-01-01

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

  9. Getting through to a qubit by magnetic solitons

    E-Print Network [OSTI]

    Alessandro Cuccoli; Davide Nuzzi; Ruggero Vaia; Paola Verrucchi

    2015-05-12

    We propose a method for acting on the spin state of a spin-1/2 localized particle, or `qubit', by means of a magnetic signal effectively generated by the nearby transit of a magnetic soliton, there conveyed through a transmission line. We first introduce the specific magnetic soliton of which we will make use, and briefly review the properties that make it apt to represent a signal. We then show that a Heisenberg spin chain can serve as transmission line, and propose a method for injecting a soliton into the chain by acting just on one of its ends. We finally demonstrate that the resulting magnetic pulse can indeed cause, just passing by the spin-1/2 localized particle embodying the qubit, a permanent change in its spin state, thus realizing the possibility of getting through to a single, localized qubit, and manipulate its state. A thorough analysis of how the overall dynamical system operates depending on the setting of its parameters demonstrates that fine tuning is not necessary as it exists an extended region in the parameters space that corresponds to an effective functioning. Moreover, we show that possible noise on the transmission line does not invalidate the scheme.

  10. Transient horizontal magnetic fields in solar plage regions

    E-Print Network [OSTI]

    R. Ishikawa; S. Tsuneta; K. Ichimoto; H. Isobe; Y. Katsukawa; B. W. Lites; S. Nagata; T. Shimizu; R. A. Shine; Y. Suematsu; T. D. Tarbell; A. M. Title

    2008-02-13

    We report the discovery of isolated, small-scale emerging magnetic fields in a plage region with the Solar Optical Telescope aboard Hinode. Spectro-polarimetric observations were carried out with a cadence of 34 seconds for the plage region located near disc center. The vector magnetic fields are inferred by Milne-Eddington inversion. The observations reveal widespread occurrence of transient, spatially isolated horizontal magnetic fields. The lateral extent of the horizontal magnetic fields is comparable to the size of photospheric granules. These horizontal magnetic fields seem to be tossed about by upflows and downflows of the granular convection. We also report an event that appears to be driven by the magnetic buoyancy instability. We refer to buoyancy-driven emergence as type1 and convection-driven emergence as type2. Although both events have magnetic field strengths of about 600 G, the filling factor of type1 is a factor of two larger than that of type2. Our finding suggests that the granular convection in the plage regions is characterized by a high rate of occurrence of granular-sized transient horizontal fields.

  11. 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: upasana@physics.iisc.ernet.in, E-mail: bm@physics.iisc.ernet.in [Department of Physics, Indian Institute of Science, Bangalore 560012 (India)

    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.

  12. Magnetic fields in beta Cep, SPB, and Be stars

    E-Print Network [OSTI]

    Schoeller, M; Briquet, M; Ilyin, I

    2013-01-01

    Recent observational and theoretical results emphasize the potential significance of magnetic fields for structure, evolution, and environment of massive stars. Depending on their spectral and photometric behavior, the upper main-sequence B-type stars are assigned to different groups, such as beta Cep stars and slowly pulsating B (SPB) stars, He-rich and He-deficient Bp stars, Be stars, BpSi stars, HgMn stars, or normal B-type stars. All these groups are characterized by different magnetic field geometry and strength, from fields below the detection limit of a few Gauss up to tens of kG. Our collaboration was the first to systematically study the magnetic fields in representative samples of different types of main-sequence B stars. In this article, we give an overview about what we have learned during the last years about magnetic fields in beta Cep, SPB, and Be stars.

  13. Magnetic fields in non-convective regions of stars

    E-Print Network [OSTI]

    Braithwaite, J

    2015-01-01

    We review the current state of knowledge of magnetic fields inside stars, concentrating on recent developments concerning magnetic fields in stably stratified (zones of) stars, leaving out convective dynamo theories and observations of convective envelopes. We include the observational properties of A, B and O-type main-sequence stars, which have radiative envelopes, and the fossil field model which is normally invoked to explain the strong fields sometimes seen in these stars. Observations seem to show that Ap-type stable fields are excluded in stars with convective envelopes. Most stars contain both radiative and convective zones, and there are potentially important effects arising from the interaction of magnetic fields at the boundaries between them, the solar cycle being one of the better known examples. Related to this, we discuss whether the Sun could harbour a magnetic field in its core. Recent developments regarding the various convective and radiative layers near the surfaces of early-type stars and...

  14. Landau quantization and mass-radius relation of magnetized White Dwarfs in general relativity

    E-Print Network [OSTI]

    Mukhopadhyay, Somnath; Basu, D N

    2015-01-01

    Recently, several white dwarfs have been proposed with masses significantly above the Chandrasekhar limit, known as Super-Chandrasekhar White Dwarfs, to account for the overluminous Type Ia supernovae. In the present work, Equation of State of a completely degenerate relativistic electron gas in magnetic field based on Landau quantization of charged particles in a magnetic field is developed. The mass-radius relations for magnetized White Dwarfs are obtained by solving the Tolman-Oppenheimer-Volkoff equations. The effects of the magnetic energy density and pressure contributed by a density-dependent magnetic field are treated properly to find the stability configurations of realistic magnetic White Dwarf stars.

  15. A comparison of two magnetic ultra-cold neutron trapping concepts using a Halbach-octupole array

    E-Print Network [OSTI]

    K. Leung; S. Ivanov; F. Martin; F. Rosenau; M. Simson; O. Zimmer

    2015-03-17

    This paper describes a new magnetic trap for ultra-cold neutrons (UCNs) made from a 1.2 m long Halbach-octupole array of permanent magnets with an inner bore radius of 47 mm combined with an assembly of superconducting end coils and bias field solenoid. The use of the trap in a vertical, magneto-gravitational and a horizontal setup are compared in terms of the effective volume and ability to control key systematic effects that need to be addressed in high precision neutron lifetime measurements.

  16. Types of Commissioning

    Broader source: Energy.gov [DOE]

    Several commissioning types exist to address the specific needs of equipment and systems across both new and existing buildings. The following commissioning types provide a good overview.

  17. 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...

  18. Ultrahigh Energy Neutrals from Extreme Magnetic Flares

    E-Print Network [OSTI]

    David Eichler

    2003-03-20

    It is shown that bulk acceleration during reconnection of extremely strong magnetic fields near compact objects can accelerate ions to Lorentz factors of $\\sim 10^2 \\sigma^{3/5}$ under general conditions, where $\\sigma$, the magnetic energy per current-carrying proton rest energy, can approach $10^{15}$. For magnetar-type fields, neutrons and neutrinos can be generated at potentially detectable levels via hadron polarization. Ultrahigh energy photons can also be emitted and escorted from the high field region by Poynting flux.

  19. Submergible barge retrievable storage and permanent disposal system for radioactive waste

    DOE Patents [OSTI]

    Goldsberry, Fred L. (Spring, TX); Cawley, William E. (Richland, WA)

    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.

  20. 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.

  1. 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.

  2. 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.

  3. Measurement of Permanent Electric Dipole Moments of Charged Hadrons in Storage Rings

    E-Print Network [OSTI]

    Jörg Pretz

    2013-07-30

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

  4. Accelerator Quality HTS Dipole Magnet Demonstrator Designs for the EuCARD-2, 5 Tesla 40 mm Clear Aperture Magnet

    E-Print Network [OSTI]

    Kirby, G A; Ballarino, A; Bottura, L; Chouika, N; Clement, S; Datskov, V; Fajardo, L; Fleiter, J; Gauthier, R; Gentini, L; Lambert, L; Lopes, M; Perez, J C; de Rijk, G; Rijllart, A; Rossi, L; ten Kate, H; Durante, M; Fazilleau, P; Lorin, C; Härö, E; Stenvall, A; Caspi, S; Marchevsky, M; Goldacker, W; Kario, A

    2015-01-01

    Future high-energy accelerators will need very high magnetic fields in the range of 20 T. The EuCARD-2 work-package-10 is a collaborative push to take HTS materials into an accelerator quality demonstrator magnet. The demonstrator will produce 5 T standalone and between 17 T and 20 T, when inserted into the 100 mm aperture of Fresca-2 high field out-sert magnet. The HTS magnet will demonstrate the field strength and field quality that can be achieved. An effective quench detection and protection system will have to be developed to operate with the HTS superconducting materials. This paper presents a ReBCO magnet design using multi strand Roebel cable that develops a stand-alone field of 5 T in a 40 mm clear aperture and discusses the challenges associated with good field quality using this type of material. A selection of magnet designs is presented as result of a first phase of development.

  5. Accelerator Quality HTS Dipole Magnet Demonstrator designs for the EuCARD-2, 5 Tesla 40 mm Clear Aperture Magnet

    E-Print Network [OSTI]

    Kirby, G; Ballarino, A; Bottura, L; Chouika, N; Clement, S; Datskov, V; Fajardo, L; Fleiter, J; Gauthier, R; Lambert, L; Lopes, M; Perez, J; DeRijk, G; Rijllart, A; Rossi, L; Ten Kate, H; Durante, M; Fazilleau, P; Lorin, C; Haro, E; Stenvall, A; Caspi, S; Marchevsky, M; Goldacker, W; Kario, A

    2014-01-01

    Future high-energy accelerators will need very high magnetic fields in the range of 20 T. The EuCARD-2 work-package-10 is a collaborative push to take HTS materials into an accelerator quality demonstrator magnet. The demonstrator will produce 5 T standalone and between 17 T and 20 T, when inserted into the 100 mm aperture of Fresca-2 high field out-sert magnet. The HTS magnet will demonstrate the field strength and field quality that can be achieved. An effective quench detection and protection system will have to be developed to operate with the HTS superconducting materials. This paper presents a ReBCO magnet design using multi strand Roebel cable that develops a stand-alone field of 5 T in a 40 mm clear aperture and discusses the challenges associated with good field quality using this type of material. A selection of magnet designs is presented as result of a first phase of development.

  6. 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.

  7. 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.

  8. 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.

  9. Magnetic Braids Anthony Yeates

    E-Print Network [OSTI]

    Dundee, University of

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

  10. Types of Lights Types of Lights

    E-Print Network [OSTI]

    1 Types of Lights Types of Lights q So far we have studied point lights ­ Radiate in all direc7ons q Other lights ­ Direc7onal lights (posi7on-independent) ­ Spotlights #12;2 Direc1onal Lights q Shine in a single, uniform direc7on q All rays

  11. 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.

  12. MAGNET CABLE MANUFACTURING

    E-Print Network [OSTI]

    Royet, J.

    2010-01-01

    76SFOOO98. MAGNET CABLE MANUFACTURING John Royet Lawrenceused in this cable manufacturing are made of superconductingapplied during manufacturing. 2.2 Twist The composite

  13. Intended Minor (if applicable)Intended Major If yes, date your card was issued: Card numberAre you a Permanent Resident, Asylee, or Refugee in the U.S.?

    E-Print Network [OSTI]

    Caughman, John

    numberAre you a Permanent Resident, Asylee, or Refugee in the U.S.? Enclose a photocopy of the front and back of your Permanent Resident, Asylee, or Refugee Card Yes No Pending Do you wish to be considered

  14. Intended Minor (if applicable)Intended Major If yes, date your card was issued: Card numberAre you a Permanent Resident, Asylee, or Refugee in the U.S.?

    E-Print Network [OSTI]

    Latiolais, M. Paul

    numberAre you a Permanent Resident, Asylee, or Refugee in the U.S.? Enclose a photocopy of the front and back of your Permanent Resident, Asylee, or Refugee Card Yes No Pending If you are neither a citizen

  15. New developments in pulsed fields at the US National High Magnetic Field Laboratory

    SciTech Connect (OSTI)

    Campbell, L.J.; Parkin, D.M.; Rickel, D.G. [Los Alamos National Lab., NM (United States); Pernambuco-Wise, P. [Florida State Univ., Tallahassee, FL (United States)

    1996-12-01

    Los Alamos National Laboratory is a member of a consortium (with Florida State University and the University of Florida) to operate the National High Magnetic Field Laboratory (NHMFL), with funding from the National Science Foundation and the State of Florida. Los Alamos provides unique resources for its component of NHMFL in the form of a 1.4 GW inertial storage motor-generator for high field pulsed magnets and infrastructure for fields generated by flux compression. The NHMFL provides a user facility open to all qualified users, develops magnet technology in association with the private sector, and advances science and technology opportunities. The magnets in service at Los Alamos are of three types. Starting with the pre-existing explosive flux compression capability in 1991, NHMFL added capacitor-driven magnets in December, 1992, and a 20 tesla superconducting magnet in January, 1993. The capacitor-driven magnets continue to grow in diversity and accessibility, with four magnet stations now available for several different magnet types. Two magnets of unprecedented size and strength are nearing completion of assembly and design, respectively. Under final assembly is a quasi-continuous magnet that contains 90 MJ of magnetic energy at full field, and being designed is a non-destructive 100 T magnet containing 140 MJ.

  16. Topology of surfaces for molecular Stark energy, alignment and orientation generated by combined permanent and induced electric dipole interactions

    E-Print Network [OSTI]

    Burkhard Schmidt; Bretislav Friedrich

    2013-12-20

    We show that combined permanent and induced electric dipole interactions of polar and polarizable molecules with collinear electric fields lead to a sui generis topology of the corresponding Stark energy surfaces and of other observables - such as alignment and orientation cosines - in the plane spanned by the permanent and induced dipole interaction parameters. We find that the loci of the intersections of the surfaces can be traced analytically and that the eigenstates as well as the number of their intersections can be characterized by a single integer index. The value of the index, distinctive for a particular ratio of the interaction parameters, brings out a close kinship with the eigenproperties obtained previously for a class of Stark states via the apparatus of supersymmetric quantum mechanics.

  17. 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.

  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 approximately 3 mm in the radial and circumferential directions on the anode. Conclusions: Active shielding is an attractive solution for correcting the effects of magnetic fields on the x-ray focal spot. If extremely long fluoroscopic exposure times are required, longer operation times can be achieved by including a permanent magnet with the active shielding design.

  19. 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.

  20. Tenure/Permanent Status Timeline UF's academic year is August 16 to August 15 for IFAS 12-month faculty.

    E-Print Network [OSTI]

    Jawitz, James W.

    , the first academic year begins August 16 of the following calendar year. The tenure/permanent status Third-Year packet is submitted to IFAS Human Resources in the summer of the third academic year. The tenure TO YEAR T/PS SUBMIT SUBMIT GRANTED THIRD-YEAR T/PS PACKET (JULY) (SUMMER) (FALL) 11/08/06 TO 11/07/07 2010