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Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

High-Temperature Superconducting Cable Testing Gregory S. Boebinger, National High Magnetic Field Laboratory  

E-Print Network [OSTI]

High-Temperature Superconducting Cable Testing Gregory S. Boebinger, National High Magnetic Field-Temperature Superconducting (HTS) Cables are desirable for application in large high-field magnets (>20 T), especially when). Of the three HTS magnet cable concepts emerging, the Conductor On Round Core was the first that was tested

Weston, Ken

2

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

E-Print Network [OSTI]

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 ...

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

2001-01-01T23:59:59.000Z

3

Superconducting magnet  

DOE Patents [OSTI]

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.

Satti, John A. (Naperville, IL)

1980-01-01T23:59:59.000Z

4

Large Superconducting Magnet Systems  

E-Print Network [OSTI]

The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb?Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb3Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 13–20 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

Védrine, P

2014-01-01T23:59:59.000Z

5

Superconducting Magnets  

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

Mit Hilfe der Technologie supraleitender Magnete lassen sich in Mit Hilfe der Technologie supraleitender Magnete lassen sich in Ringbeschleunigern höhere Energien erreichen. Weil supraleitende Spulen keinen elektrischen Widerstand aufweisen, können damit stärkere Magnetfelder erzeugt werden. In normal leitenden Elektromagneten wird - wegen des elektrischen Widerstands der Drähte - die Spule aufgeheizt. Auf diese Weise geht sehr viel Energie in Form von Wärme verloren, was die Energiekosten dieser Magnete in die Höhe treibt. Supraleitende Spulen erlauben es, Magnete grosser Feldstärke unter günstigen Bedingungen zu betreiben und damit die Energiekosten zu senken. Durch den Einbau supraleitender Spulen in den Ringbeschleuniger von Fermilab konnte dessen Energie verdoppelt werden.Auch der im Bau befindliche "Large Hadron Collider" am CERN wird supraleitende Magnete

6

Magnetism and Superconductivity in Iron Pnictides  

SciTech Connect (OSTI)

The discovery of high temperature superconductivity in iron pnictides and chalcogenides has resulted in surprising new insights into high temperature superconductivity and its relationship with magnetism. Here we provide an overview of some of what is known about these materials and in particular about the interplay of magnetism and superconductivity in them. Similarities and contrasts with cuprate superconductors are emphasized and the superconducting pairing is discussed within the framework of spin fluctuation induced pairing.

Singh, David J [ORNL

2012-01-01T23:59:59.000Z

7

Ramesh Gupta | Superconducting Magnet Division  

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

Ramesh Gupta Ramesh Gupta Ramesh Gupta has always been a leader in the world of superconducting magnets, which are essential to great modern accelerators such as the Relativistic Heavy Ion Collider at BNL, and the Large Hadron Collider at CERN, Switzerland. For the past decade, Lab researchers have been exploring the use of new materials that become superconducting at higher temperatures. Gupta, head of the High Temperature Superconductor (HTS) Research and Development Group in the Superconducting Magnet Division, is among those exploring avenues for HTS magnets that are energy efficient and have magnetic fields that are a million times stronger than the Earth's. These new magnets could revolutionize use in future accelerators, play a key role in energy efficiency and storage, and make possible new

8

Superconducting Magnet Division  

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

3 - 6/13/06 3 - 6/13/06 Superconducting Magnet Division S&T Committee Program Review June 22-23, 2006 Conference Room A, Bldg. 725, BNL DRAFT AGENDA Thursday, June 22 0830 Executive Session to address the charge S. Aronson (25 min) 0855 Welcome S. Aronson (5 min) 0900 Superconducting Magnet Division Status & M. Harrison (45 + 15 min) Issues - mission statement, core competencies, themes, program, problems, etc. 1000 Themes - Nb3Sn, HTS, Direct wind, Accelerator integration, P. Wanderer (20 + 10 min) rapid cycling Core Competencies 1030 Superconducting Materials A. Ghosh (20 + 5 min) 1055 Break 1110 Magnetic Design R. Gupta (20 + 5 min) 1135 Magnet Construction M. Anerella (20 + 5 min) 1200 Magnet Testing G. Ganetis (20 + 5 min)

9

HTS Magnet Program | Superconducting Magnet Division  

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

HTS Magnet Program HTS Magnet Program High Temperature Superconductors (HTS) have the potential to revolutionize the field of superconducting magnets for particle accelerators, energy storage and medical applications. This is because of the fact that as compared to the conventional Low Temperature Superconductors (LTS), the critical current density (Jc ) of HTS falls slowly both: as a function of increasing field, and as a function of increasing temperature These unique properties can be utilized to design and build: HTS magnets that produce very high fields (20 - 50 T) HTS magnets that operate at elevated temperatures (20 - 77 K) This is a significant step forward over the convention LTS magnets which generally operate at a temperature of ~4 K and with field usually limited

10

AFRD - Superconducting Magnets  

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

Superconducting Magnets Superconducting Magnets Home Organization Diversity Safety Links Gallery/History Updated July 2008 Ever-stronger magnets (which must be cost-effective as well) are a key to building tomorrow's high-energy accelerators and upgrading today's. Our role— not only a leading R&D group but also the administrators of the multi-institutional National Conductor Development Program— to create both evolutionary improvements and paradigm shifts in the application of accelerator magnets, providing innovative technology that enables new science. Improvements in conductor, innovative structures to solve the challenges of high fields and brittle superconductors, and integration of computerized design and analysis tools are key. The performance requirements of modern accelerators continue to press the

11

Superconducting Magnet Division  

E-Print Network [OSTI]

in the 400 kW end of RIA's Fragment Separator are subjected to several orders of magnitude more radiation an order of magnitude as compared to that for present superconducting accelerator magnets. An OPERA3d model://www.phy.anl.gov/ria/ http://www.orau.org/ria/ Figure: On this chart of the nuclides, black squares represent stable nuclei

Gupta, Ramesh

12

High-temperature superconducting magnet for use in saturated core FCL  

Science Journals Connector (OSTI)

A HTS magnet system used in a saturated core Fault Current Limiter (FCL) device is described. The superconducting magnet, operating in DC mode, is used in such FCL design for saturating the magnetic core and maintaining low device impedance under nominal conditions. The unique design of the FCL poses constrains on the DC HTS magnet. A model which meets all the necessary special requirements have been realized in a compact magnet design that is optimized for its electrical characteristics while minimizing its mass and volume. The coil, made of Bi-2223 tapes, has 50000 Ampere-turns required to maintain the core in a saturated state at nominal current in the limiting circuit. Unique, nonmagnetic cryostat made of Delrin was used. Cooling of the coil has been realized by two cold heads: one double-stage head that provides a cooling power of 6 W at 20 K and a single-stage head with a cooling capability of 40W at 70 K. This magnetic system has been successfully integrated and tested in a 120 kVA FCL model. The design, characteristics and tests of this magnetic system are described.

Z Bar-Haim; A Friedman; Y Wolfus; V Rozenshtein; F Kopansky; Z Ron; E Harel; N Pundak; Y Yeshurun

2008-01-01T23:59:59.000Z

13

Improved superconducting magnet wire  

DOE Patents [OSTI]

This invention is directed to a superconducting tape or wire composed of alternating layers of copper and a niobium-containing superconductor such as niobium of NbTi, Nb/sub 3/Sn or Nb/sub 3/Ge. In general, each layer of the niobium-containing superconductor has a thickness in the range of about 0.05 to 1.5 times its coherence length (which for Nb/sub 3/Si is 41 A) with each copper layer having a thickness in the range of about 170 to 600 A. With the use of very thin layers of the niobium composition having a thickness within the desired range, the critical field (H/sub c/) may be increased by factors of 2 to 4. Also, the thin layers of the superconductor permit the resulting tape or wire to exhibit suitable ductility for winding on a magnet core. These compositions are also characterized by relatively high values of critical temperature and therefore will exhibit a combination of useful properties as superconductors.

Schuller, I.K.; Ketterson, J.B.

1983-08-16T23:59:59.000Z

14

Superconducting trapped-field magnets: Temperature and field distributions during pulsed-field activation  

E-Print Network [OSTI]

progress in fabrication of large-sized high- temperature superconductors with high critical current den We calculate the temperature and magnetic field distributions in a bulk superconductor during leads to a strong temperature rise in superconductor during the activation pro- cess. There have already

Johansen, Tom Henning

15

Superconductivity Program Overview High-Temperature Superconductivity  

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

SuperconducTiviTy program haS Three FocuS areaS: SuperconducTiviTy program haS Three FocuS areaS: SuperconducTiviTy applicaTionS Developing HTS-based electric power equipment such as transmission and distribution cables and fault current limiters Second-generaTion Wire developmenT Developing high-performance, low-cost, second- generation HTS wire at long lengths STraTegic reSearch Supporting fundamental research activities to better understand relationships between the microstructure of HTS materials and their ability to carry large electric currents over long lengths Superconductivity Program Overview High-Temperature Superconductivity for Electric Systems Office of Electricity Delivery and Energy Reliability www.oe.energy.gov Office of Electricity Delivery and Energy Reliability, OE-1 U.S. Department of Energy - 1000 Independence Avenue, SW - Washington, DC 20585

16

Permanent magnet design for high-speed superconducting bearings  

DOE Patents [OSTI]

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.

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

1996-09-10T23:59:59.000Z

17

Superconductivity and Magnetism: Materials Properties  

E-Print Network [OSTI]

#12;#12;Superconductivity and Magnetism: Materials Properties and Developments #12;Copyright 2003 and Magnetism: Materials Properties and Developments Extended abstracts of the 24th Risø International Symposium LABORATORY ROSKILDE, DENMARK #12;Risø International Symposium on Superconductivity and Magnetism: Material

18

Characterization of a high-temperature superconducting conductor on round core cables in magnetic fields up to 20 T  

SciTech Connect (OSTI)

The next generation of high-field magnets that will operate at magnetic fields substantially above 20 T, or at temperatures substantially above 4.2 K, requires high-temperature superconductors (HTS). Conductor on round core (CORC) cables, in which RE-Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} (RE = rare earth) (REBCO) coated conductors are wound in a helical fashion on a fl?exible core, are a practical and versatile HTS cable option for low-inductance, high-field magnets. We performed the first tests of CORC magnet cables in liquid helium in magnetic fields of up to 20 T. A record critical current I{sub c} of 5021 A was measured at 4.2 K and 19 T. In a cable with an outer diameter of 7.5 mm, this value corresponds to an engineering current density J{sub e} of 114 A mm{sup -2} , the highest J{sub e} ever reported for a superconducting cable at such high magnetic fields. Additionally, the first magnet wound from an HTS cable was constructed from a 6 m-long CORC cable. The 12-turn, double-layer magnet had an inner diameter of 9 cm and was tested in a magnetic field of 20 T, at which it had an I{sub c} of 1966 A. The cables were quenched repetitively without degradation during the measurements, demonstrating the feasibility of HTS CORC cables for use in high-field magnet applications.

van der Laan, Danko [Advanced Conductor Technologies; Noyes, Patrick [National High Magnetic Field Laboratory; Miller, George [National High Magnetic Field Laboratory; Weijers, Hubertus [National High Magnetic Field Laboratory; Willering, Gerard [CERN

2013-02-13T23:59:59.000Z

19

atlas superconducting magnet: Topics by E-print Network  

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

Room temperature, water cooled copper magnets produceSuperconducting Magnet Division TEST RESULTS OF HTS COILS AND AN R&D MAGNET FOR RIA* R. Gupta, M. Anerella, M. Harrison,...

20

High Field Magnet R&D |Superconducting Magnet Division  

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

High Field Magnet R&D High Field Magnet R&D The Superconducting Magnet Division is developing advanced magnet designs and magnet-related technologies for high field accelerator magnets. We are currently working on magnets for three inter-related programs: High Field Magnets for Muon Collider Papers, Presentations Common Coil Magnets Papers, Presentations Interaction Region Magnets Papers, Presentations High Temperature Superconductor (HTS) Magnets Papers, Presentations This is part of a multi-lab superconducting magnet development program for new accelerator facilities that would be part of the U.S. High Energy Physics program. These programs (@BNL, @FNAL, @LBNL) are quite complimentary to each other, so that magnet designs and technologies developed at one laboratory can be easily transferred to another. The BNL

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Brett Parker | Superconducting Magnet Division  

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

Brett Parker Brett Parker Recent Presentations "BNL Direct Wind Magnets," (pdf) presentation dedicated to the memory of Pat Thompson given at the 22nd Magnet Technology Conference (MT22), September 11 - 16, 2011, Marseille, France A Review of BNL Direct-Wind Superconducting IR Magnet Experience, (pdf) presented at the 30th Advanced ICFA Beam Dynamics Workshop on High Luminosity e+e- Collisions, October 13 - 16, 2003, Stanford, California The Serpentine Coil Design for BEPC-II Superconducting IR Magnets, (pdf) presented at the "Mini-Workshop on BEPC-II IR Design", January 12 - 16, 2004, Beijing, P.R. China Ma nufacture of a Superconducting Octupole Magnet for the ALPHA Experiment at CERN using the Direct Wind Machine Presentations Prior to 2004 Superconducting Final Focus Magnet Issues (pdf), presented at

22

Superconducting magnetic energy storage  

SciTech Connect (OSTI)

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

Hassenzahl, W.

1988-08-01T23:59:59.000Z

23

Philosophy 26 High Temperature Superconductivity  

E-Print Network [OSTI]

is the ratio of voltage to current. The resistance of a material tells us how a low resistance, and they are therefore good conductors; other materials, likePhilosophy 26 High Temperature Superconductivity By Ohm's Law, resistance

Callender, Craig

24

Superconducting Magnet Safety Nuclear Magnetic Resonance (NMR) facilities present unique hazards not found in most  

E-Print Network [OSTI]

Superconducting Magnet Safety Nuclear Magnetic Resonance (NMR) facilities present unique hazards or steel reinforced concrete, these ferromagnetic materials may have an effect on the magnetic field environmental temperature control is required (2) Structural support for heavy equipment and vibration control

Maroncelli, Mark

25

Hermetically sealed superconducting magnet motor  

DOE Patents [OSTI]

A hermetically sealed superconducting magnet motor includes a rotor separated from a stator by either a radial gap, an axial gap, or a combined axial and radial gap. Dual conically shaped stators are used in one embodiment to levitate a disc-shaped rotor made of superconducting material within a conduit for moving cryogenic fluid. As the rotor is caused to rotate when the field stator is energized, the fluid is pumped through the conduit.

DeVault, Robert C. (Knoxville, TN); McConnell, Benjamin W. (Knoxville, TN); Phillips, Benjamin A. (Benton Harbor, MI)

1996-01-01T23:59:59.000Z

26

Hermetically sealed superconducting magnet motor  

DOE Patents [OSTI]

A hermetically sealed superconducting magnet motor includes a rotor separated from a stator by either a radial gap, an axial gap, or a combined axial and radial gap. Dual conically shaped stators are used in one embodiment to levitate a disc-shaped rotor made of superconducting material within a conduit for moving cryogenic fluid. As the rotor is caused to rotate when the field stator is energized, the fluid is pumped through the conduit. 6 figs.

DeVault, R.C.; McConnell, B.W.; Phillips, B.A.

1996-07-02T23:59:59.000Z

27

Method for obtaining large levitation pressure in superconducting magnetic bearings  

DOE Patents [OSTI]

A method and apparatus are disclosed for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap. 4 figs.

Hull, J.R.

1997-08-05T23:59:59.000Z

28

RHIC Project | Superconducting Magnet Division  

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

RHIC Project RHIC Project The Superconducting Magnet Division supplied 1740 magnetic elements, in 888 cryostats, for the RHIC facility at BNL. Of these, 780 magnetic elements were manufactured by Northrop-Grumman (Bethpage, NY) and 360 were made by Everson Electric (Bethlehem, PA). The magnets made in industry used designs developed at BNL. The first cooldown of the magnets for the RHIC engineering run was in 1999. Since then, the magnets have operated very reliably. arc dipole coil and yoke Arc dipole coil and yoke, with magnetic flux lines The magnets provide modest field (3.45 Teslas in the arc dipoles) in a cost-effective design. Key features in the principal bending and focusing magnets include the use of NbTi Rutherford cable, a single-layer coil, and cold iron as both yoke and collar. The magnets operate in forced-flow

29

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network [OSTI]

The impact of high temperature superconductors is includedimpact of high temperature superconductor 011 SMES have beenIMPACT OF HIGH CRITICAL TEMPERATURE SUPERCONDUCTORS ON SMES

Hassenzahl, W.

2011-01-01T23:59:59.000Z

30

Superconducting magnet wire  

DOE Patents [OSTI]

A superconducting tape or wire with an improved critical field is formed of alternating layers of a niobium-containing superconductor such as Nb, NbTi, Nb.sub.3 Sn or Nb.sub.3 Ge with a thickness in the range of about 0.5-1.5 times its coherence length, supported and separated by layers of copper with each copper layer having a thickness in the range of about 170-600 .ANG..

Schuller, Ivan K. (Woodridge, IL); Ketterson, John B. (Evanston, IL); Banerjee, Indrajit (San Jose, CA)

1986-01-01T23:59:59.000Z

31

Structural and magnetic phase diagram of CeFeAsO1-xFx and its relation tohigh-temperature superconductivity  

SciTech Connect (OSTI)

Recently, high-transition-temperature (high-T{sub c}) superconductivity was discovered in the iron pnictide RFeAsO{sub 1-x}F{sub x} (R, rare-earth metal) family of materials. We use neutron scattering to study the structural and magnetic phase transitions in CeFeAsO{sub 1-x}F{sub x} as the system is tuned from a semimetal to a high-T{sub c} superconductor through fluorine (F) doping, x. In the undoped state, CeFeAsO develops a structural lattice distortion followed by a collinear antiferromagnetic order with decreasing temperature. With increasing fluorine doping, the structural phase transition decreases gradually and vanishes within the superconductivity dome near x = 0.10, whereas the antiferromagnetic order is suppressed before the appearance of superconductivity for x > 0.06, resulting in an electronic phase diagram remarkably similar to that of the high-T{sub c} copper oxides. Comparison of the structural evolution of CeFeAsO{sub 1-x}F{sub x} with other Fe-based superconductors suggests that the structural perfection of the Fe-As tetrahedron is important for the high-T{sub c} superconductivity in these Fe pnictides.

Zhao, Jun [ORNL; Huang, Q. [National Institute of Standards and Technology (NIST); Dela Cruz, Clarina R [ORNL; Shiliang, Li [University of Tennessee, Knoxville (UTK); Lynn, J. W. [National Institute of Standards and Technology (NIST); Chen, Ying [National Institute of Standards and Technology (NIST); Green, Mark [National Institute of Standards and Technology (NIST); Chen, G. F, [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics; Li, G. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics; Li, Z. [Beijing National Laboratory for Condensed Matter Physics/Chinese Academy of Scie; Luo, J. L. [Chinese Academy of Sciences; Wang, N. L. [Chinese Academy of Sciences; Dai, Pengcheng [ORNL

2008-01-01T23:59:59.000Z

32

Cryogenic structural materials for superconducting magnets  

SciTech Connect (OSTI)

This paper reviews research in the United States and Japan on structural materials for high-field superconducting magnets. Superconducting magnets are used for magnetic fusion energy devices and for accelerators that are used in particle-physics research. The cryogenic structural materials that we review are used for magnet cases and support structures. We expect increased materials requirements in the future.

Dalder, E.N.C.; Morris, J.W. Jr.

1985-02-22T23:59:59.000Z

33

Superconducting Magnet Technology for Future Hadron Colliders  

SciTech Connect (OSTI)

The application of superconducting magnets to large-scale particle accelerators was successfully demonstrated with the completion of the Tevatron at Fermilab in 1983. This machine, utilizing dipole magnets operating at 4.5 T, has been operating successfully for the past 12 years. This success was followed a few years later by HERA, an electron-proton collider that uses superconducting quadrupoles and dipoles of a design similar to those in the Tevatron. The next major project was the ill-fated SSC, which was cancelled in 1993. However, the SSC R&D effort did succeed in demonstrating the reliable operation of dipole magnets up to 6.6 T. The LHC, now under construction, pushes the ductile superconductor, NbTi, to its limit in dipoles designed to operate at fields of 8.6 T at 1.8 K. Several recent studies have addressed the issues involved in taking the next step beyond the LHC. The Division of Particles and Fields Workshop on Future Hadron Facilities in the U.S., held at Indiana U. in 1994, examined two possible facilities--a 2-TeV on 2-TeV collider and a 30-Tev on 30-Tev collider. The participants arrived at the following conclusions with regard to superconducting magnets: (1) Superconducting magnets are the enabling technology for high energy colliders. As such, the highest priority for the future of hadron facilities in the U.S. is the reassembly of a U.S. superconducting magnet R&D program. (2) emphasis on conductor development and new magnet designs; and (3) goals of such a program might be (a) the development of a 9-10 Tesla magnet based on NbTi technology; (b) the development of high quality quadrupoles with gradients in the range 250-300 T/m; and (c) initiation of R&D activities aimed at moving beyond the existing technology as appears to be required for the development of a magnet operating at 12-15 Tesla. In order to reach fields above 10 T, magnet designers must turn to new materials with higher critical fields than that of NbTi. Several candidate conductors exist; unfortunately, all of these new materials are brittle, and thus pose new challenges to the magnet designers. At the same time that the forces on the magnet windings are increasing due to the higher Lorentz force associated with the higher magnetic fields, the conductor tensile strain must be limited to less than about 0.5% to prevent damage to the brittle superconducting material. Also, coil fabrication methods must be changed. If the superconductor is in the reacted, or brittle, state, the coil winding procedure must be modified to prevent overstraining. If the alternative wind and react approach is used, new insulating materials must be used that can survive the high temperature reactions (650 to 800 C) necessary to form the superconducting compounds. The issues associated with high-field dipole magnets have been discussed at a number of workshops, including those at DESY in 1991 and LBL in 1992. These workshops were extremely useful in defining the problems and focusing the attention of both materials and magnet experts on high-field dipole magnets; however, since neither set of proceedings was published, the information is not readily available. More recently, a workshop was held in Erice, Italy, under the sponsorship of the Ettore Maiorana Center for Scientific Culture. This international workshop was attended by 20 scientists from Europe, Japan, and the U.S., and the summary of that work, which represents the most recent and thorough assessment of the status of high-field magnets for accelerator magnets, is presented.

Scanlan, R.M.; Barletta, W.A.; Dell'Orco, D.; McInturff, A.D.; Asner, A.; Collings, E.W.; Dahl, P.F.; Desportes, H.; Devred, A.; Garre, R.; Gregory, E.; Hassenzahl, W.; Lamm, M.; Larbalestier, D.; Leory, D.; McIntyre, P.; Miller, J.; Shintomi, T.; ten Kate, H.; Wipf, S.

1994-10-01T23:59:59.000Z

34

Microcalorimeter Magnetic Sensor Geometries Using Superconducting Elements  

SciTech Connect (OSTI)

We describe a numerical code developed to estimate performance of magnetic microcalorimeter configurations, including superconducting elements and SQUID characteristics. We present results of a preliminary design analysis showing that composite sensors with both superconducting and paramagnetic elements should realize substantial gains in magnetic flux signal per magnetization change of the paramagnet, compared to sensors containing only paramagnet.

Boyd, S. T. P. [University of New Mexico, MSC07 4220, Albuquerque NM 87131-0001 (United States); Cantor, R. H. [STAR Cryoelectronics, 25-A Bisbee Ct., Santa Fe NM 87508-1338 (United States)

2009-12-16T23:59:59.000Z

35

LHC Magnet Program | Superconducting Magnet Division  

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

Magnet Program Magnet Program The Superconducting Magnet Division is building a number of dipole magnets for the Large Hadron Collider (LHC), which is now under construction at CERN in Geneva, Switzerland. Scheduled to begin operation in 2007, this machine will collide beams of protons with the unprecedented energy of 7 TeV per beam to explore the nature of matter at its most basic level (RHIC can collide beams of protons with energies of 0.25 TeV, but is mostly used to collide heavy ions with energies of 0.1 TeV per nucleon). The magnets are being built as part of the US program, recommended by the High Energy Physics Advisory Panel (HEPAP) and approved by Congress, to contribute to the construction and, later, use of that frontier machine by the US high energy physics community. Fermi National Accelerator Laboratory (FNAL) and

36

J-PARC Correctors | Superconducting Magnet Division  

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

Magnet Construction Magnet Construction The final turn of the J-PARC extracted proton beam is a superconducting combined function magnet line. The combined function magnets are dipole cable magnets, typical of cold mass collared magnets, but have been designed to include a large component of quadrupole field. This provides both bending and focussing of the proton beam prior to target impact, where neutrinos will be produced. The BNL Superconducting Magnet Division is using its direct wind facility to produce superconducting corrector magnets to be used in conjunction with the combined function magnets. combined function magnet The first direct wind magnet set designed and fabricated is a combined function magnet with an additional skew dipole. This magnet is intended to be used within the cable collared combined function dipole used for the

37

Magnetism and superconductivity observed to exist in harmony  

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

Magnetism and superconductivity exist in harmony Magnetism and superconductivity observed to exist in harmony Physicists have observed, for the first time in a single exotic phase,...

38

Static forces in a superconducting magnet bearing  

SciTech Connect (OSTI)

Static levitation forces and stiffnesses in a superconducting bearing consisting of concentric ring magnets and a superconducting YBaCuO ring are investigated. In the field-cooled mode a levitation force of 20 N has been achieved. The axial and radial stiffnesses have values of 15 N/mm and 10 N/mm, respectively. An arrangement with two bearings supporting a high speed shaft is now under development. A possible application of superconducting magnetic bearings is flywheels for energy storage.

Stoye, P.; Fuchs, G. [Institut fuer Festkoerper- und Werkstofforschung, Dresden (Germany)] [Institut fuer Festkoerper- und Werkstofforschung, Dresden (Germany); Gawalek, W.; Goernert, P. [Institut fuer Physikalische Hochtechnologie, Jena (Germany)] [Institut fuer Physikalische Hochtechnologie, Jena (Germany); Gladun, A. [Technische Univ., Dresden (Germany)] [Technische Univ., Dresden (Germany)

1995-11-01T23:59:59.000Z

39

Superconducting Magnet Division | Brookhaven National Laboratory  

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

Superconducting Magnet Division Superconducting Magnet Division Home Production & Testing LHC Dipole Acceptance APUL Schedule (pdf) Projects Main Projects HTS Magnet Program High Field Magnet R&D Linear Collider Final Focus e Lens Solenoid Correctors for J-PARC Correctors for SuperKEKB IR Magnets LARP APUL Past Projects BEPC-II IR Quadrupoles Bio-Med Variable Field MRI GSI Rapid Cycling Magnets Helical Magnets HERA upgrade LHC IR Dipoles RHIC Publications Search Publications Selected Cryogenic Data Notebook Proceedings of the 1968 Summer Study on Superconducting Devices and Accelerators Meetings & Workshops Safety Environmental, Safety & Health ES&H Documents Lockout-Tagout Personnel Staff Pages Ramesh Gupta Brett Parker Peter Wanderer Pe ter Wanderer, head of Brookhaven's Superconducting Magnet Division,

40

High Temperature Superconducting Underground Cable  

SciTech Connect (OSTI)

The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the world’s first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

Farrell, Roger, A.

2010-02-28T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Fiber Bragg Grating Cryo-Sensors for Superconducting Accelerator Magnets  

E-Print Network [OSTI]

The design, fabrication and tests of the new generation of superconducting magnets for the High Luminosity upgrade of the Large Hadron Collider (HL - LHC) require the support of an adequate sensing technology able to assure the integrity of the strain sensitive and brittle superconducting cables through the whole service life of the magnet: assembly up to 150 MPa, cool down to 1.9 K and powering up to about 16 kA. A precise temperature monitoring is also needed in order to guarantee the safe working condition of the superconducting cables in the power transmission lines (SC - Link) designed to feed the magnet over long distance. Temperature and strain FBGs based monitoring systems have been implemented in the first SC-Link prototype and in two subscale dipole magnets and tested in the cryogenic test facility at CERN at 30 K, 77 K and 1.9 K.

Chiuchiolo, A; Perez, J; Bajas, H; Consales, M; Giordano, M; Breglio, G; Cusano, A

2014-01-01T23:59:59.000Z

42

Study of Superconducting Fault Current Limiter Using Saturated Magnetic Core  

Science Journals Connector (OSTI)

This paper presents a saturated magnetic core superconducting current limiter (SCSFCL) operation simulation results using finite element technique. The superconducting current limiter uses BSCCO tape to produce m...

F. Fajoni; E. Ruppert; C. A. Baldan…

2014-11-01T23:59:59.000Z

43

Aluminum in Superconducting Magnets Robert J. Weggel  

E-Print Network [OSTI]

Aluminum in Superconducting Magnets Robert J. Weggel Magnet Optimization Research Engineering is aluminum, either ultrapure, as quenchstabilization matrix metal, and/or alloyed and coldworked and heat for magnets in which the stresses and strains are modest. The strongest aluminum alloy commercially available

McDonald, Kirk

44

e Lens Solenoid | Superconducting Magnet Division  

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

Electron Lens Solenoid Electron Lens Solenoid To increase the proton beam luminosity in RHIC, an electron lens (e-lens) magnet system with two superconducting solenoids is being built at Brookhaven National Laboratory. Initial Design of 200 mm, 6T Superconducting Solenoid for e-lens (pdf), R. Gupta, 3/30/10 Iterated Design of 200 mm, 6T Superconducting Solenoid for e-lens (pdf), R. Gupta, 4/6/10 Corrector Designs for Superconducting Solenoid for e-lens (pdf), R. Gupta, 4/14/10 eLens Layout (pdf), P. Kovach, 5/25/10 eLens Main Solenoid (pdf), A. Marone, 5/25/10 Optimization in Corrector Design for Superconducting Solenoid for e-Lens (pdf), R. Gupta, 6/15/10 Main Solenoid Axial Force Retention (pdf), A. Marone 8/24/10 Superconducting Solenoid for e-lens with Fringe Field Coil (pdf), R.

45

Interplay of superconductivity, magnetism, and density waves in rare-earth tritellurides and iron-based superconducting materials  

E-Print Network [OSTI]

3. Magnetism in Metals . . . . . . . . . . . . . . . . .IV Superconductivity and Magnetism in Iron-PnictideIII Superconductivity, Magnetism and Charge-Density Waves in

Zocco, Diego Andrés

2011-01-01T23:59:59.000Z

46

High temperature superconductive flux gate magnetometer  

SciTech Connect (OSTI)

This paper proposes a different type of HTS superconducting magnetometer based on the non-linear magnetic behavior of bulk HTS materials. The device design is based on the generation of second harmonics which arise as a result of non-linear magnetization observed in Type-II superconductors. Even harmonics are generated from the non-linear interaction of an ac excitation signal with an external DC magnetic field which acts as a bias signal.

Gershenson, M. (Naval Coastal Systems Center, Panama City, FL (United States))

1991-03-01T23:59:59.000Z

47

Magnetism and superconductivity in quark matter  

E-Print Network [OSTI]

Magnetic properties of quark matter and its relation to the microscopic origin of the magnetic field observed in compact stars are studied. Spontaneous spin polarization appears in high-density region due to the Fock exchange term, which may provide a scenario for the behaviors of magnetars. On the other hand, quark matter becomes unstable to form spin density wave in the moderate density region, where restoration of chiral symmetry plays an important role. Coexistence of magnetism and color superconductivity is also discussed.

T. Tatsumi; E. Nakano; K. Nawa

2005-06-01T23:59:59.000Z

48

A probe for investigating the effects of temperature, strain, and magnetic field on transport critical currents in superconducting  

E-Print Network [OSTI]

magnetic fields. The strain is applied to the wire by soldering it to a thick coiled spring and twisting one end of the spring with respect to the other. Strain can be applied reversibly from 0.7% to 0 to test long straight samples can be constructed for use in split-coil magnets, but the maximum field

Hampshire, Damian

49

Manufacturing and Testing of Accelerator Superconducting Magnets  

E-Print Network [OSTI]

Manufacturing of superconducting magnet for accelerators is a quite complex process that is not yet fully industrialized. In this paper, after a short history of the evolution of the magnet design and construction, we review the main characteristics of the accelerator magnets having an impact on the construction technology. We put in evidence how the design and component quality impact on construction and why the final product calls for a total-quality approach. LHC experience is widely discussed and main lessons are spelled out. Then the new Nb3Sn technology, under development for the next generation magnet construction, is outlined. Finally, we briefly review the testing procedure of accelerator superconducting magnets, underlining the close connection with the design validation and with the manufacturing process.

Rossi, L

2014-01-01T23:59:59.000Z

50

GSI Rapid Cycling Magnets Project | Superconducting Magnet Division  

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

GSI Rapid Cycling Magnets Project GSI Rapid Cycling Magnets Project While superconducting magnets easily achieve higher magnetic fields at lower cost than conventional electromagnets, it is very difficult to ramp superconducting magnets very quickly. But exactly that is needed at the planned new facility of GSI, the Gesellschaft für Schwerionenforschung (Institute for Heavy Ion Research), in Darmstadt, Germany. In the magnets of the SIS 200 ring, one of the components of the new facility, the magnetic field must be ramped from 0.5 Tesla to 4 Tesla at a rate of 1 Tesla per second. This ramp rate is almost 25 times faster than the ramp rate of the Relativistic Heavy Ion Collider (RHIC) magnets at Brookhaven National Lab (BNL), which ramp at a rate of 0.042 Tesla per second. While the SIS 200 magnets also require a slightly higher field strength than the

51

Fiber Optic Cryogenic Sensors for Superconducting Magnets and Superconducting Power Transmission lines at CERN  

E-Print Network [OSTI]

The design, fabrication and tests of a new generation of superconducting magnets for the upgrade of the LHC require the support of an adequate, robust and reliable sensing technology. The use of Fiber Optic Sensors is becoming particularly challenging for applications in extreme harsh environments such as ultra-low temperatures, high electromagnetic fields and strong mechanical stresses offering perspectives for the development of technological innovations in several applied disciplines.

Chiuchiolo, A; Cusano, A; Bajko, M; Perez, J C; Bajas, H; Giordano, M; Breglio, G; Palmieri, L

2014-01-01T23:59:59.000Z

52

Superconducting strip in an oblique magnetic field  

Science Journals Connector (OSTI)

As an example for a seemingly simple but actually intricate problem, we study the Bean critical state in a superconducting strip of finite thickness d and width 2w?d placed in an oblique magnetic field. The analytical solution is obtained to leading order in the small parameter d?w. The critical state depends on how the applied magnetic field is switched on, e.g., at a constant tilt angle, or first the perpendicular and then the parallel field component. For these two basic scenarios we obtain the distributions of current density and magnetic field in the critical states. In particular, we find the shapes of the flux-free core and of the lines separating regions with opposite direction of the critical currents, the detailed magnetic field lines (along the vortex lines), and both components of the magnetic moment. The component of the magnetic moment parallel to the strip plane is a nonmonotonic function of the applied magnetic field.

G. P. Mikitik; E. H. Brandt; M. Indenbom

2004-07-30T23:59:59.000Z

53

5 - High temperature superconductor (HTS) magnets  

Science Journals Connector (OSTI)

Abstract: At the time of writing, high temperature superconducting magnets have not fulfilled their early promise, mainly because of the difficulties in getting these reactive and brittle ceramics into wire form and, consequently, their expense. However, for some niche applications, HTS magnets have been developed. In this chapter, the author outlines his experience of building four such systems after introductory discussions about superconducting magnets in general and design considerations. The recent commercial availability of so-called second-generation (2G) coated conductors opens up a more promising scenario, provided the cost can come down. This scenario is discussed and some conclusions are drawn.

H. Jones

2012-01-01T23:59:59.000Z

54

Superconducting magnets for toroidal fusion reactors  

SciTech Connect (OSTI)

Fusion reactors will soon be employing superconducting magnets to confine plasma in which deuterium and tritium (D-T) are fused to produce usable energy. At present there is one small confinement experiment with superconducting toroidal field (TF) coils: Tokamak 7 (T-7), in the USSR, which operates at 4 T. By 1983, six different 2.5 x 3.5-m D-shaped coils from six manufacturers in four countries will be assembled in a toroidal array in the Large Coil Test Facility (LCTF) at Oak Ridge National Laboratory (ORNL) for testing at fields up to 8 T. Soon afterwards ELMO Bumpy Torus (EBT-P) will begin operation at Oak Ridge with superconducting TF coils. At the same time there will be tokamaks with superconducting TF coils 2 to 3 m in diameter in the USSR and France. Toroidal field strength in these machines will range from 6 to 9 T. NbTi and Nb/sub 3/Sn, bath cooling and forced flow, cryostable and metastable - various designs are being tried in this period when this new application of superconductivity is growing and maturing.

Haubenreich, P.N.

1980-01-01T23:59:59.000Z

55

HERA Upgrade Project | Superconducting Magnet Division  

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

HERA Upgrade Project HERA Upgrade Project As part of the HERA luminosity upgrade, 6 superconducting Interaction Region quadrupoles were delivered, accepted, and are in service. These 6 layer magnets were designed to include the main quadrupole focus, a skew quad, a normal and skew dipole, and a final sextupole layer. Because of the physical space constraints imposed by the existing detector region components, the DESY magnets were of necessity designed to be very compact. In addition, they are also are required to operate within the solenoidal detector fields at the collision points, so all construction materials had to be non magnetic. Two types of DESY magnets were fabricated. The first, designated as G0, was a two meter long, constant radius magnet. The second, designated GG, is a

56

High-Temperature Superconductivity Cable Demonstration Projects  

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

Temperature Temperature Superconductivity Cable Demonstration Projects Superconductivity Power Equipment www.oe.energy.gov Phone: 202-586-1411 Office of Electricity Delivery and Energy Reliability, OE-1 U.S. Department of Energy - 1000 Independence Avenue, SW - Washington, DC 20585. Plugging America Into the Future of Power "A National Effort to Introduce New Technology into the Power Delivery Infrastructure" "In order to meet President Obama's ambitious energy goals, we must modernize the nation's electrical grid to improve the transmission, storage and reliability of clean energy across the country and help to move renewable energy from the places it can be produced to the places it can be used. The Department of Energy is working with industry partners to develop the

57

Support system design for a superconducting MRI magnet  

E-Print Network [OSTI]

shields cooled to intermediate temperanires. The rest of the heat transfer is solid conduction through various components. One of these components is the magnet support system. The support system for a superconducting magnet suspends the components at 4.... A design of a support system for a superconducting magnet was developed. This system will be used to suspend the Texas Accelerator Center (TAC) liquid helium cooled, four tesla, one meter bore, superconducting coils (cold mass) inside a room...

Watts, Louis Chad

1993-01-01T23:59:59.000Z

58

Energy of magnetic moment of superconducting current in magnetic field  

E-Print Network [OSTI]

The energy of magnetic moment of the persistent current circulating in superconducting loop in an externally produced magnetic field is not taken into account in the theory of quantization effects because of identification of the Hamiltonian with the energy. This identification misleads if, in accordance with the conservation law, the energy of a state is the energy expended for its creation. The energy of magnetic moment is deduced from a creation history of the current state in magnetic field both in the classical and quantum case. But taking this energy into account demolishes the agreement between theory and experiment. Impartial consideration of this problem discovers the contradiction both in theory and experiment.

V. L. Gurtovoi; A. V. Nikulov

2014-12-22T23:59:59.000Z

59

New Superconducting Magnet Will Lead to Next Generation of Wind...  

Energy Savers [EERE]

announced that their superconducting magnet system passed a landmark reliability test, demonstrating its potential suitability for wide-scale commercial applications. This...

60

Novel Approach to Linear Accelerator Superconducting Magnet System  

SciTech Connect (OSTI)

Superconducting Linear Accelerators include a superconducting magnet system for particle beam transportation that provides the beam focusing and steering. This system consists of a large number of quadrupole magnets and dipole correctors mounted inside or between cryomodules with SCRF cavities. Each magnet has current leads and powered from its own power supply. The paper proposes a novel approach to magnet powering based on using superconducting persistent current switches. A group of magnets is powered from the same power supply through the common, for the group of cryomodules, electrical bus and pair of current leads. Superconducting switches direct the current to the chosen magnet and close the circuit providing the magnet operation in a persistent current mode. Two persistent current switches were fabricated and tested. In the paper also presented the results of magnetic field simulations, decay time constants analysis, and a way of improving quadrupole magnetic center stability. Such approach substantially reduces the magnet system cost and increases the reliability.

Kashikhin, Vladimir; /Fermilab

2011-11-28T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

VLHC Meeting | Superconducting Magnet Division  

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

Second Annual Very Large Hadron Collider (VLHC) Meeting Second Annual Very Large Hadron Collider (VLHC) Meeting October 16 - 18, 2000 The Second Annual Meeting of the Very Large Hadron Collider (VLHC) was be held on Monday, October 16 through Wednesday, October 18, 2000. It took place at Danfords in Port Jefferson, NY, about 30 minutes from Brookhaven National Laboratory. The meeting featured reports of the U.S. effort towards a post-LHC hadron collider. The program included an overview of physics in the 100 TeV c.m. regime, reports on superconductor and magnet R&D, as well as studies of accelerators and accelerator systems. The agenda also included a roundtable discussion of plans for future activities. Presentations VLHC Update (pdf), Mike Harrison, BNL Physics at Very High Energies (pdf), Sekhar Chivukula, Boston

62

Transformer current sensor for superconducting magnetic coils  

DOE Patents [OSTI]

A transformer current sensor having primary turns carrying a primary current for a superconducting coil and secondary turns only partially arranged within the primary turns. The secondary turns include an active winding disposed within the primary turns and a dummy winding which is not disposed in the primary turns and so does not experience a magnetic field due to a flow of current in the primary turns. The active and dummy windings are wound in opposite directions or connected in series-bucking relationship, and are exposed to the same ambient magnetic field. Voltages which might otherwise develop in the active and dummy windings due to ambient magnetic fields thus cancel out. The resultant voltage is purely indicative of the rate of change of current flowing in the primary turns.

Shen, Stewart S. (Oak Ridge, TN); Wilson, C. Thomas (Norris, TN)

1988-01-01T23:59:59.000Z

63

Pseudogap and Superconducting Gap in High-Temperature Superconductors  

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

Pseudogap and Superconducting Gap in Pseudogap and Superconducting Gap in High-Temperature Superconductors Two decades after the discovery of first high temperature superconductors, the microscopic mechanism of high-Tc superconductivity remains elusive. In conventional superconductors, it has been well established that electrons form so-called "Cooper pairs" to give rise to superconductivity. The pair binding manifests itself as an energy gap in many spectroscopic measurements. This energy gap, known as superconducting gap, appears at the superconducting transition temperature Tc where the resistance also vanishes. For high temperature superconductors, the story is more complicated. Over a wide region of compositions and temperatures, there exists an energy gap well above Tc. This energy gap is called pseudogap [1], because there is no direct correlation to the superconducting transition. The origin of this pseudogap and its relation to the superconducting gap are believed to hold the key for understanding the mechanism of high-Tc superconductivity - one of the outstanding problems in condensed matter physics. In this regard, researchers Kiyohisa Tanaka and Wei-Sheng Lee, along with their co-workers in Prof. Zhi-Xun Shen's group at Stanford University, have recently made an important discovery about the coexistence of two distinct energy gaps that have opposite doping dependence. Their observation not only provides a natural explanation for the contradictory results about the superconducting gap deduced from different experimental techniques, but also has profound implications on the mechanism of high-Tc superconductivity.

64

Development of superconducting magnet systems for HIFExperiments  

SciTech Connect (OSTI)

The U.S. Heavy Ion Fusion program is developing superconducting focusing quadrupoles for near-term experiments and future driver accelerators. Following the fabrication and testing of several models, a baseline quadrupole design was selected and further optimized. The first prototype of the optimized design achieved a conductor-limited gradient of 132 T/m in a 70 mm bore, with measured field harmonics within 10 parts in 10{sup 4}. In parallel, a compact focusing doublet was fabricated and tested using two of the first-generation quadrupoles. After assembly in the cryostat, both magnets reached their conductor-limited quench current. Further optimization steps are currently underway to improve the performance of the magnet system and reduce its cost. They include the fabrication and testing of a new prototype quadrupole with reduced field errors as well as improvements of the cryostat design for the focusing doublet. The prototype units will be installed in the HCX beamline at LBNL, to perform accelerator physics experiments and gain operational experience. Successful results in the present phase will make superconducting magnets a viable option for the next generation of integrated beam experiments.

Sabbi, Gian Luca; Faltens, A.; Leitzke, A.; Seidl, P.; Lund, S.; Martovets ky, N.; Chiesa, L.; Gung, C.; Minervini, J.; Schultz, J.; Goodzeit, C.; Hwang, P.; Hinson, W.; Meinke, R.

2004-07-27T23:59:59.000Z

65

Cooling system for superconducting magnet  

DOE Patents [OSTI]

A cooling system is configured to control the flow of a refrigerant by controlling the rate at which the refrigerant is heated, thereby providing an efficient and reliable approach to cooling a load (e.g., magnets, rotors). The cooling system includes a conduit circuit connected to the load and within which a refrigerant circulates; a heat exchanger, connected within the conduit circuit and disposed remotely from the load; a first and a second reservoir, each connected within the conduit, each holding at least a portion of the refrigerant; a heater configured to independently heat the first and second reservoirs. In a first mode, the heater heats the first reservoir, thereby causing the refrigerant to flow from the first reservoir through the load and heat exchanger, via the conduit circuit and into the second reservoir. In a second mode, the heater heats the second reservoir to cause the refrigerant to flow from the second reservoir through the load and heat exchanger via the conduit circuit and into the first reservoir. 3 figs.

Gamble, B.B.; Sidi-Yekhlef, A.

1998-12-15T23:59:59.000Z

66

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

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

Linear Collider Final Focus Magnet Construction Linear Collider Final Focus Magnet Construction The final focus magnets for the International Linear Collider require very small quadrupoles be placed within the detector background field for both the entrance and exit beams. The use of superconducting magnets for this function provide solutions to several problems confronting the machine designers. One constraint is the operation within the 3 tesla detector field. The direct wind magnets are capable of operation without the use of magnetic materials in their construction, making them ideal for compact focussing solutions within detectors. The second constraint is the small physical size dictated by the crossing angle of the beams and proximity to the IR within the detector solenoid. The Direct Wind design does not require a collar to withstand Lorentz

67

Magnetic phase diagram of small superconducting two-loop networks  

E-Print Network [OSTI]

The critical magnetic behaviour of simple superconducting micro-networks is illustrat- ed by discussing several properties of super- conducting micro-networks [1-3], see also [4]. This theoretical activity has beenL-277 Magnetic phase diagram of small superconducting two-loop networks J. Riess Centre de

Paris-Sud XI, Université de

68

J-PARC Correctors | Superconducting Magnet Division  

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

J-PARC Correctors J-PARC Correctors Physics Japan is constructing a 50 Gev, high intensity proton accelerator at a site near the Japanese high energy research laboratory, KEK. The project is called J-PARC (Japan Proton Accelerator Research Complex). The site is at Tokai and is part of the Japanese Atomic Energy Research Institute (JAERI). KEK and JAERI are jointly responsible for its construction. J-PARC will serve many uses. One of the uses will be to produce neutrinos that will be directed toward a detector located in Kamiokande, Japan. The neutrinos will be produced when protons are extracted from J-PARC and are directed by magnets in a beam line to strike a target. Further information about the neutrino experiment is available. KEK and the BNL Superconducting Magnet Division are working together to

69

Estimating the cost of large superconducting thin solenoid magnets  

SciTech Connect (OSTI)

The cost of thin superconducting solenoid magnets can be estimated if one knows the magnet stored energy, the magnetic field volume product or the overall mass of the superconducting coil and its cryostat. This report shows cost data collected since 1979 for large superconducting solenoid magnets used in high energy physics. These magnets are characterized in most cases by the use of indirect two phase helium cooling and a superconductor stabilizer of very pure aluminum. This correlation can be used for making a preliminary cost estimate of proposed one of a kind superconducting magnets. The magnet costs quoted include the power supply and quench protection system but the cost of the helium refrigerator and helium distribution system is not included in the estimated cost.

Green, M.A. [Lawrence Berkeley Lab., CA (United States); St. Lorant, S.J. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

1993-07-01T23:59:59.000Z

70

MAGNETIC DESIGN OF A SUPERCONDUCTING AGS SNAKE.  

SciTech Connect (OSTI)

Brookhaven National Laboratory plans to build a partial helical snake for polarized proton acceleration in the AGS. It will be a 3 Tesla superconducting magnet having a magnetic length of 1.9 meter. AGS needs only one magnet and currently there is no plan to build a prototype. Therefore, the first magnet itself must function at the design operating field and provide the required field quality, spin rotation and deflections on the particle beam. New software have been developed that exchanges input/output between the OPERA3d field design program, the Pro-Engineering CAD model and the software that drives the machine to make slots in aluminum cylinders where blocks of 6-around-I NbTi wires are placed. This new software have been used to carry out a number of iterations to satisfy various design requirements and to assure that the profile that is used in making field computations is the same that is used in cutting metal. The optimized coil cross-section is based on a two layer design with both inner and outer layers having five current blocks per quadrant. The ends are based on a design concept that will be used for the first time in accelerator magnets.

GUPTA,R.; LUCCIO,A.; MORGAN,G.; MACKAY,W.; POWER,K.; ROSER,T.; WILLEN,E.; OKAMURA,M.

2003-05-12T23:59:59.000Z

71

Cryogenic deformation of high temperature superconductive composite structures  

DOE Patents [OSTI]

An improvement in a process of preparing a composite high temperature oxide superconductive wire is provided and involves conducting at least one cross-sectional reduction step in the processing preparation of the wire at sub-ambient temperatures.

Roberts, Peter R. (Groton, MA); Michels, William (Brookline, MA); Bingert, John F. (Jemez Springs, NM)

2001-01-01T23:59:59.000Z

72

LOTO Authorized Personnel | Superconducting Magnet Division  

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

Lockout/Tagout (LOTO) Personnel Lockout/Tagout (LOTO) Personnel Primary Authorized Employee Have the training and/or experience to exercise group and system-level judgments, and are authorized to lockout and tagout any equipment for which they have division's approval. If coordinated multiple lock and tags are applied by more than one employee, those of the "primary authorized employee" must be the first to be applied and the last to be removed. SMD - LOTO Primary Authorized Personnel Name Phone # Systems/Group Raymond Ceruti Ext. 7116 Mechanical Engineering Technical Support John Cintorino Ext. 2544 Magnet Test & Measurement Joseph D'Ambra Ext. 3764 Superconducting Materials R&D Sebastian Dimaiuta Ext. 5265 Electrical Systems Technical Support Glenn Jochen Ext. 7320 Mechanical Engineering Technical Support

73

A simple figure of merit for high temperature superconducting switches  

SciTech Connect (OSTI)

The discovery of the new high temperature superconductors has revived interest in many special applications, including superconducting switches. For comparison of switch types, a simple figure of merit based in switch performance is proposed, derived for superconducting switches, and then calculated for thyristors and vacuum switches. The figure of merit is then used to show what critical current density would be needed for superconducting switches to compete with more conventional switches. 46 refs., 1 fig.

Honig, E.M.

1989-01-01T23:59:59.000Z

74

Magnetic order and superconductivity in RBa2Cu3Oz  

Science Journals Connector (OSTI)

Mössbauer studies Fe57 in RBa2-yKy(Cu1-xFex)3Oz, with R=Y and Pr, y=0 and 0.5, x=0.01,0.05, and 0.1, and z between 5.9 and 7.1, have been performed. A minority of the iron ions enter the Cu(2) site and reveal its magnetic order. For R=Y, y=0, and x=0.1, TN equals 280 and 415 K for z=6.5 and 6.1, respectively. The magnetic moments lie in the basal plane. In tetragonal, oxygen-rich PrBa2(Cu0.9Fe0.1)3O6.9, TN=325 K; in superconducting YBa2(Cu0.9Fe0.1)3O7.1 there is no magnetic order. In nonsuperconducting YBa1.5K0.5(Cu0.95Fe0.05)3O6.1 two distinctly inequivalent magnetic iron sites are observed, corresponding to iron in the Cu(2) site with different Ba-K neighbors. Moments of iron ions that have three Ba and one K as first-nearest neighbors have a different temperature dependence and TN (TN=450 K) from those with four Ba neighbors, where TN=415 K, showing that the antiferromagnetic exchange in the Cu(2) planes is strongly affected by the replacement of Ba2+ by K+, probably by repelling oxygen from the Cu(2) plane. In superconducting YBa1.5K0.5(Cu0.95Fe0.05)3O6.5 the iron site with TN=450 K remains magnetic. The implications of these findings on the valencies of the Cu ions are discussed.

I. Nowik; M. Kowitt; I. Felner; E. R. Bauminger

1988-10-01T23:59:59.000Z

75

Magnetism and Superconductivity Compete in Iron-based Superconductors...  

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

Magnetism and Superconductivity Compete in Iron-based Superconductors Wednesday, April 30, 2014 HTSC Figure 1 Fig. 1. Measured electronic structure of underdoped Ba1-xKxFe2As2 in...

76

Method of constructing a superconducting magnet  

DOE Patents [OSTI]

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.

Satti, John A. (Naperville, IL)

1981-01-01T23:59:59.000Z

77

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

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

Single Strand Superconductor Windings Single Strand Superconductor Windings Initial direct wind quad coils were constructed using 13 mil diameter single strand wire. This wire provides the smallest coil patterns possible, with quad coils wound easily onto .75 inch (19mm) diameter support tubes. The 13mil diameter superconductor gives the smallest coils possible, the penalty being higher inductance and smaller transfer function, but allowing lower operational currents. long model magnet Figure 1 shows the first one foot long model magnet constructed using the 11 axis ultrasonic wiring machine with 13 mil superconducting wire, the same wire previously used for the 472 RHIC Corrector packages. Existing stock materials were used in the construction, and the coil pattern was not optimized for harmonics, but to put as many coil turns onto the tube as

78

High Temperature Superconducting Racetrack Coils for Electric Motor Applications  

Science Journals Connector (OSTI)

American Superconductor Corporation (ASC) has designed and fabricated racetrack-shaped field coils from PbBSSCO-2223 high temperature superconducting (HTS) wire for a 125 HP, four-pole motor currently being devel...

J. P. Voccio; C. B. Prum; M. J. Navarro…

1997-01-01T23:59:59.000Z

79

Journal of Superconductivity: Incorporating Novel Magnetism ( C 2005) DOI: 10.1007/s10948-005-0005-2  

E-Print Network [OSTI]

Journal of Superconductivity: Incorporating Novel Magnetism ( C 2005) DOI: 10.1007/s10948) and a 10 °A thick Ge spacer layer. From temperature- dependent magnetization and hysteresis loop; ferromagnetism; MBE. Recently, magnetic semiconductors have at- tracted great attention due to the potential

Medvedeva, Julia E.

80

National High Magnetic Field Laboratory - Applied Superconductivity...  

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

viable present materials for superconducting application to electric power transmission lines, fault current limiters, transformers, electromagnets and motors. UW-Madison has...

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

National High Magnetic Field Laboratory - Applied Superconductivity...  

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

viable present materials for superconducting application to electric power transmission lines, fault current limiters, transformers, electromagnets and motors. Coated Conductors We...

82

Light weight, high field, stable, superconducting magnets for advanced transportation systems  

SciTech Connect (OSTI)

Although the Guideway may be the most expensive component of a MAGLEV system, the importance of a suitable magnet system should not be underestimated. The reliability of operation of MAGLEV depends on the superconducting magnets performing to their specifications in a reliable manner (i.e., without training or quenching). Besides reliability the magnets should produce high field, be sufficiently stable to withstand reasonable perturbations, be light weight, be protected in the event of a quench, and be economical (although performance should outweigh cost). We propose to develop superconducting magnets that have these features. Our magnet designs are based on internally cooled, cable-in-conduit superconductor with Polymer Matrix Composites (PMC) as the structural reinforcement. Although the initial work is with metallic superconductors such as NbTi, the processes being developed will be applicable to the High Temperature Ceramic Superconductors when they become suitable for magnet applications.

Lubell, M.S.; Dresner, L.; Kenney, W.J.; Lue, J.W.; Luton, J.N.; Schwenterly, S.W.

1991-01-01T23:59:59.000Z

83

Flywheel energy storage using superconducting magnetic bearings  

SciTech Connect (OSTI)

Storage of electrical energy on a utility scale is currently not practicable for most utilities, preventing the full utilization of existing base-load capacity. A potential solution to this problem is Flywheel Energy Storage (FES), made possible by technological developments in high-temperature superconducting materials. Commonwealth Research Corporation (CRC), the research arm of Commonwealth Edison Company, and Argonne National Laboratory are implementing a demonstration project to advance the state of the art in high temperature superconductor (HTS) bearing performance and the overall demonstration of efficient Flywheel Energy Storage. Currently, electricity must be used simultaneously with its generation as electrical energy storage is not available for most utilities. Existing storage methods either are dependent on special geography, are too expensive, or are too inefficient. Without energy storage, electric utilities, such as Commonwealth Edison Company, are forced to cycle base load power plants to meet load swings in hourly customer demand. Demand can change by as much as 30% over a 12-hour period and result in significant costs to utilities as power plant output is adjusted to meet these changes. HTS FES systems can reduce demand-based power plant cycling by storing unused nighttime capacity until it is needed to meet daytime demand.

Abboud, R.G. [Commonwealth Research Corp., Chicago, IL (United States); Uherka, K.; Hull, J.; Mulcahy, T. [Argonne National Lab., IL (United States)

1994-04-01T23:59:59.000Z

84

High performance magnetic bearing systems using high temperature superconductors  

DOE Patents [OSTI]

Disclosed are a magnetic bearing apparatus and a method for providing at least one stabilizing force in a magnetic bearing structure with a superconducting magnetic assembly and a magnetic assembly, by providing a superconducting magnetic member in the superconducting magnetic assembly with a plurality of domains and arranging said superconducting magnetic member such that at least one domain has a domain C-axis vector alignment angularly disposed relative to a reference axis of the magnetic member in the magnetic assembly. 7 figs.

Abboud, R.G.

1998-05-05T23:59:59.000Z

85

High performance magnetic bearing systems using high temperature superconductors  

DOE Patents [OSTI]

A magnetic bearing apparatus and a method for providing at least one stabilizing force in a magnetic bearing structure with a superconducting magnetic assembly and a magnetic assembly, by providing a superconducting magnetic member in the superconducting magnetic assembly with a plurality of domains and arranging said superconducting magnetic member such that at least one domain has a domain C-axis vector alignment angularly disposed relative to a reference axis of the magnetic member in the magnetic assembly.

Abboud, Robert G. (Barrington Hills, IL)

1998-01-01T23:59:59.000Z

86

Unconventional temperature enhanced magnetism in iron telluride  

SciTech Connect (OSTI)

Discoveries of copper and iron-based high-temperature superconductors (HTSC)1-2 have challenged our views of superconductivity and magnetism. Contrary to the pre-existing view that magnetism, which typically involves localized electrons, and superconductivity, which requires freely-propagating itinerant electrons, are mutually exclusive, antiferromagnetic phases were found in all HTSC parent materials3,4. Moreover, highly energetic magnetic fluctuations, discovered in HTSC by inelastic neutron scattering (INS) 5,6, are now widely believed to be vital for the superconductivity 7-10. In two competing scenarios, they either originate from local atomic spins11, or are a property of cooperative spin-density-wave (SDW) behavior of conduction electrons 12,13. Both assume clear partition into localized electrons, giving rise to local spins, and itinerant ones, occupying well-defined, rigid conduction bands. Here, by performing an INS study of spin dynamics in iron telluride, a parent material of one of the iron-based HTSC families, we have discovered that this very assumption fails, and that conduction and localized electrons are fundamentally entangled. In the temperature range relevant for the superconductivity we observe a remarkable redistribution of magnetism between the two groups of electrons. The effective spin per Fe at T 10 K, in the2 antiferromagnetic phase, corresponds to S 1, consistent with the recent analyses that emphasize importance of Hund s intra-atomic exchange15-16. However, it grows to S 3/2 in the disordered phase, a result that profoundly challenges the picture of rigid bands, broadly accepted for HTSC.

Zalinznyak, I. [Brookhaven National Laboratory (BNL); Xu, Zhijun [ORNL; Tranquada, John M. [Brookhaven National Laboratory (BNL); Gu, G. D. [Brookhaven National Laboratory (BNL); Tsvelik, A. [Brookhaven National Laboratory (BNL); Stone, Matthew B [ORNL

2011-01-01T23:59:59.000Z

87

Development of Pre?Preg Ceramic Insulation for Superconducting Magnets  

Science Journals Connector (OSTI)

A new pre?impregnated (pre?preg) ceramic?based electrical insulation system capable of surviving high superconductor reaction temperatures has been developed for use in superconducting magnets. The use of Nb 3Sn superconductors holds great promise for increased magnet performance for high energy physics fusion and other applications. A robust cost?effective manufacturing process is critical to the successful implementation of these coils. Due to its embrittlement after the high temperature reaction cycle Nb 3Sn cable is usually insulated and wound into the coil prior to heat treatment. An earlier ceramic?based insulation system applied using wet?winding or vacuum impregnation has been successfully used in the “wind and react” fabrication process. Use of the new pre?preg system will further simplify the manufacturing process while improving control over the insulation properties. Pre?preg insulation offers several advantages including improved dimensional control of the insulation controllable and uniform fiber to matrix ratio and certainty that the insulation does not infiltrate the superconductor. This paper describes the pre?preg development process processing properties as well as insulation performance data at cryogenic temperatures.

D. E. Codell; P. E. Fabian

2004-01-01T23:59:59.000Z

88

SUPERCONDUCTING DIPOLE MAGNETS FOR THE LHC INSERTION REGIONS  

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

SUPERCONDUCTING DIPOLE MAGNETS FOR THE LHC INSERTION SUPERCONDUCTING DIPOLE MAGNETS FOR THE LHC INSERTION REGIONS E. Willen, M. Anerella, J. Cozzolino, G. Ganetis, A. Ghosh, R. Gupta, M. Harrison, A. Jain, A. Marone, J. Muratore, S. Plate, J. Schmalzle, P. Wanderer, K.C. Wu, Brookhaven National Laboratory, Upton, NY 11973, USA Abstract Dipole bending magnets are required to change the horizontal separation of the two beams in the LHC. In Intersection Regions (IR) 1, 2, 5, and 8, the beams are brought into collision for the experiments located there. In IR4, the separation of the beams is increased to accommodate the machine's particle acceleration hardware. As part of the US contribution to the LHC Project, BNL is building the required superconducting magnets. Designs have been developed featuring a single

89

DESIGN REQUIREMENTS AND OPTIONS FOR FINAL FOCUSING SUPERCONDUCTING MAGNETS  

E-Print Network [OSTI]

of using both high-temperature superconductors and con- ventional low-temperature superconductors and operated in particle accelera- tors!. It should be mentioned that before high-temperature superconductor are investi- gated. The use of high-temperature superconducting materials may offer an attractive, although

California at San Diego, University of

90

Superconducting Magnets for M.H.D. Generators [and Discussion  

Science Journals Connector (OSTI)

...Superconducting Magnets for M.H.D. Generators [and Discussion] P. F. Chester W...their application in large m.h.d. generators. The newly exploited hard superconductors...J in the case of a large m.h.d. generator magnet. It will be shown that this...

1967-01-01T23:59:59.000Z

91

Manipulating the magnetic state of a carbon nanotube Josephson junction using the superconducting phase  

E-Print Network [OSTI]

We study the supercurrent of a carbon nanotube quantum dot Josephson junction in a parameter regime in which the Kondo energy and the superconducting gap are of comparable size. For gate voltages in the vicinity of a Kondo ridge the superconducting phase difference can then be used to tune the magnetic state from a singlet to a doublet. Accordingly our measured current phase relation crosses over from 0 to $\\pi$-junction behavior, exhibiting strong anharmonicities. The experimental results are in excellent agreement with our numerically exact finite temperature quantum Monte Carlo simulations and provide insights on the phase-controlled level-crossing transition at zero temperature.

R. Delagrange; D. J. Luitz; R. Weil; A. Kasumov; V. Meden; H. Bouchiat; R. Deblock

2015-01-14T23:59:59.000Z

92

New Superconducting Magnet Will Lead to Next Generation of Wind Turbine Generators  

Broader source: Energy.gov [DOE]

AML Superconductivity and Magnetics, in conjunction with DOE's Argonne National Laboratory, recently announced that their superconducting magnet system passed a landmark reliability test, demonstrating its potential suitability for wide-scale commercial applications.

93

Dynamic high pressure process for fabricating superconducting and permanent magnetic materials  

DOE Patents [OSTI]

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

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

1987-10-23T23:59:59.000Z

94

Superconducting magnetic Wollaston prism for neutron spin encoding  

SciTech Connect (OSTI)

A magnetic Wollaston prism can spatially split a polarized neutron beam into two beams with different neutron spin states, in a manner analogous to an optical Wollaston prism. Such a Wollaston prism can be used to encode the trajectory of neutrons into the Larmor phase associated with their spin degree of freedom. This encoding can be used for neutron phase-contrast radiography and in spin echo scattering angle measurement (SESAME). In this paper, we show that magnetic Wollaston prisms with highly uniform magnetic fields and low Larmor phase aberration can be constructed to preserve neutron polarization using high temperature superconducting (HTS) materials. The Meissner effect of HTS films is used to confine magnetic fields produced electromagnetically by current-carrying HTS tape wound on suitably shaped soft iron pole pieces. The device is cooled to ?30 K by a closed cycle refrigerator, eliminating the need to replenish liquid cryogens and greatly simplifying operation and maintenance. A HTS film ensures that the magnetic field transition within the prism is sharp, well-defined, and planar due to the Meissner effect. The spin transport efficiency across the device was measured to be ?98.5% independent of neutron wavelength and energizing current. The position-dependent Larmor phase of neutron spins was measured at the NIST Center for Neutron Research facility and found to agree well with detailed simulations. The phase varies linearly with horizontal position, as required, and the neutron beam shows little depolarization. Consequently, the device has advantages over existing devices with similar functionality and provides the capability for a large neutron beam (20 mm × 30 mm) and an increase in length scales accessible to SESAME to beyond 10 ?m. With further improvements of the external coupling guide field in the prototype device, a larger neutron beam could be employed.

Li, F., E-mail: fankli@indiana.edu; Parnell, S. R.; Wang, T.; Baxter, D. V. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States)] [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States); Hamilton, W. A. [Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)] [Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Maranville, B. B. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)] [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Semerad, R. [Ceraco Ceramic Coating GmbH, Ismaning 85737 (Germany)] [Ceraco Ceramic Coating GmbH, Ismaning 85737 (Germany); Cremer, J. T. [Adelphi Technology Inc., Redwood City, California 94063 (United States)] [Adelphi Technology Inc., Redwood City, California 94063 (United States); Pynn, R. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States) [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States); Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)

2014-05-15T23:59:59.000Z

95

Cryogen free superconducting splittable quadrupole magnet for linear accelerators  

SciTech Connect (OSTI)

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

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

2011-09-01T23:59:59.000Z

96

Optimization of superconducting tiling pattern for superconducting bearings  

DOE Patents [OSTI]

An apparatus and method for reducing magnetic field inhomogeneities which produce rotational loss mechanisms in high temperature superconducting magnetic bearings are disclosed. Magnetic field inhomogeneities are reduced by dividing high temperature superconducting structures into smaller structures, and arranging the smaller structures into tiers which stagger the magnetic field maximum locations of the smaller structures. 20 figs.

Hull, J.R.

1996-09-17T23:59:59.000Z

97

Optimization of superconducting tiling pattern for superconducting bearings  

DOE Patents [OSTI]

An apparatus and method for reducing magnetic field inhomogeneities which produce rotational loss mechanisms in high temperature superconducting magnetic bearings. Magnetic field inhomogeneities are reduced by dividing high temperature superconducting structures into smaller structures, and arranging the smaller structures into tiers which stagger the magnetic field maximum locations of the smaller structures.

Hull, John R. (Hinsdale, IL)

1996-01-01T23:59:59.000Z

98

E-Print Network 3.0 - astromag superconducting magnet Sample...  

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

superconducting cuprates have the capability to pass very high currents in magnetic fields well above the highest... DC field in the world, the 45 tesla hybrid magnet (a ......

99

Construction of the CERN Fast Cycled Superconducting Dipole Magnet Prototype  

E-Print Network [OSTI]

CERN is pursuing a small scale R&D on a fast cycled superconducting dipole magnet (FCM) of interest for the upgrade plan of the LHC accelerator complex. The FCM dipole prototype being built has a number of novel features if compared to other magnets for similar applications. In this paper we describe the magnet design, and its expected performance, focusing especially on the novel features (magnetic circuit, mechanical supports, cooling) and on the details of the manufacturing procedure (coil winding and impregnation, joints, instrumentation and quench protection).

Borgnolutti, F; Bottura, L; Carra, F; Foffano, G; Gomes De Faria, J M; Kalouguine, O; Kirby, G; Lopez, C; Tommasini, D

2012-01-01T23:59:59.000Z

100

Method and apparatus for measuring gravitational acceleration utilizing a high temperature superconducting bearing  

DOE Patents [OSTI]

Gravitational acceleration is measured in all spatial dimensions with improved sensitivity by utilizing a high temperature superconducting (HTS) gravimeter. The HTS gravimeter is comprised of a permanent magnet suspended in a spaced relationship from a high temperature superconductor, and a cantilever having a mass at its free end is connected to the permanent magnet at its fixed end. The permanent magnet and superconductor combine to form a bearing platform with extremely low frictional losses, and the rotational displacement of the mass is measured to determine gravitational acceleration. Employing a high temperature superconductor component has the significant advantage of having an operating temperature at or below 77K, whereby cooling may be accomplished with liquid nitrogen.

Hull, John R. (Downers Grove, IL)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

A Toy Model Study of Decay Trapping | Superconducting Magnet Division  

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

A Toy Model Study of Decay Trapping, reported by Brett Parker A Toy Model Study of Decay Trapping, reported by Brett Parker Introduction A group from the BNL Superconducting Magnet Division is looking at various options for dipole magnets which would be suitable for use in a muon storage ring that is used as a neutrino factory. Since the useful neutrino beams from a neutrino factory come from straight sections it is desirable to minimize the rings arc circumference, in relation to straight section length, in order to ensure that the fraction of muons which decay in the straight section is as large as possible. Therefore superconducting magnets, with higher B-fields and smaller bend radii, are reasonable to consider for this application. Unfortunately the decay electrons generated along with the neutrinos carry on average about a third of the original

102

Dynamic high pressure process for fabricating superconducting and permanent magnetic materials  

DOE Patents [OSTI]

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

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

1990-03-13T23:59:59.000Z

103

Possible diminution of impurity pair breaking for triplet pairing superconductivity in two-dimensional or quasi-two-dimensional, weakly localized, nearly magnetic systems  

SciTech Connect (OSTI)

We propose a conjecture according to which, as a consequence of weak localization in two-dimensional, nearly magnetic itinerant paramagnets, the pair-breaking parameter due to normal impurity scattering, in triplet pairing superconductivity, may be reduced at low enough temperature. It might then, in principle, become easier to observe triplet pairing superconductivity in dirty two-dimensional or quasi-two-dimensional metals, than in three-dimensional ones; thus some recently observed puzzling superconductive behaviors should be reexamined.

Beal-Monod, M.T.; Ebisawa, H.; Fukuyama, H.

1984-08-01T23:59:59.000Z

104

Ultra-high quality factors in superconducting niobium cavities in ambient magnetic fields up to 190 mG  

E-Print Network [OSTI]

Ambient magnetic field, if trapped in the penetration depth, leads to the residual resistance and therefore sets the limit for the achievable quality factors in superconducting niobium resonators for particle accelerators. Here we show that a complete expulsion of the magnetic flux can be performed and leads to: 1) record quality factors $Q > 2\\times10^{11}$ up to accelerating gradient of 22 MV/m; 2) $Q\\sim3\\times10^{10}$ at 2 K and 16 MV/m in up to 190 mG magnetic fields. This is achieved by large thermal gradients at the normal/superconducting phase front during the cooldown. Our findings open up a way to ultra-high quality factors at low temperatures and show an alternative to the sophisticated magnetic shielding implemented in modern superconducting accelerators.

Romanenko, A; Crawford, A C; Sergatskov, D A; Melnychuk, O

2014-01-01T23:59:59.000Z

105

Magnetic preferential orientation of metal oxide superconducting materials  

DOE Patents [OSTI]

A superconductor comprised of a polycrystalline metal oxide such as YBa[sub 2]Cu[sub 3]O[sub 7[minus]X] (where 0 < X < 0.5) exhibits superconducting properties and is capable of conducting very large current densities. By aligning the two-dimensional Cu-O layers which carry the current in the superconducting state in the a- and b-directions, i.e., within the basal plane, a high degree of crystalline axes alignment is provided between adjacent grains permitting the conduction of high current densities. The highly anisotropic diamagnetic susceptibility of the polycrystalline metal oxide material permits the use of an applied magnetic field to orient the individual crystals when in the superconducting state to substantially increase current transport between adjacent grains. In another embodiment, the anisotropic paramagnetic susceptibility of rare-earth ions substituted into the oxide material is made use of as an applied magnetic field orients the particles in a preferential direction. This latter operation can be performed with the material in the normal (non-superconducting) state. 4 figs.

Capone, D.W.; Dunlap, B.D.; Veal, B.W.

1990-07-17T23:59:59.000Z

106

Magnetic preferential orientation of metal oxide superconducting materials  

DOE Patents [OSTI]

A superconductor comprised of a polycrystalline metal oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-X (where 0superconducting properties and is capable of conducting very large current densities. By aligning the two-dimensional Cu-O layers which carry the current in the superconducting state in the a- and b-directions, i.e., within the basal plane, a high degree of crystalline axes alignment is provided between adjacent grains permitting the conduction of high current densities. The highly anisotropic diamagnetic susceptibility of the polycrystalline metal oxide material permits the use of an applied magnetic field to orient the individual crystals when in the superconducting state to substantially increase current transport between adjacent grains. In another embodiment, the anisotropic paramagnetic susceptibility of rare-earth ions substituted into the oxide material is made use of as an applied magnetic field orients the particles in a preferential direction. This latter operation can be performed with the material in the normal (non-superconducting) state.

Capone, Donald W. (Bolingbrook, IL); Dunlap, Bobby D. (Bolingbrook, IL); Veal, Boyd W. (Downers Grove, IL)

1990-01-01T23:59:59.000Z

107

Spontaneous quenches of a high temperature superconducting pancake coil  

SciTech Connect (OSTI)

A double-pancake coil made of Bi-2223/Ag high temperature superconducting (HTS) tape was constructed with an embedded heater and graded conductors to study the stability and quench propagation in HTS coils. The experiments were performed with liquid nitrogen and gaseous helium cooling in temperatures ranging from 5 to 77 K. The coil was very stable, and no ``normal`` zone was sustained or propagated with local pulsed heating. However, spontaneous quenches of the cod were experienced. This was found to be the result of having the coil current higher than that of the lower I{sub c} sections of the coil for a long time. This quench process took minutes to develop--much longer than would be expected in a low temperature superconducting coil. The quench behaved more like a spreading and continuous heating of an increasingly larger partially resistive section of the coil than like a sequential ``normal`` front propagation.

Lue, J.W.; Lubell, M.S. [Oak Ridge National Lab., TN (United States); Aized, D.; Campbell, J.M.; Schwall, R.E. [American Superconductor Corp., Westborough, MA (United States)

1995-09-01T23:59:59.000Z

108

Spontaneous quenches of a high temperature superconducting pancake coil  

SciTech Connect (OSTI)

A double-pancake coil made of Bi-2223/Ag high temperature superconducting (HTS) tape was constructed with an embedded heater and graded conductors to study the stability and quench propagation in HTS coils. The experiments were performed with liquid nitrogen and gaseous helium cooling in temperatures ranging from 5 to 77 K. The coil was very stable, and no normal zone was sustained or propagated with local pulsed heating. However, spontaneous quenches of the coil were experienced. This was found to be the result of having the coil current higher than that of the lower I{sub c} sections of the coil for a long time. This quench process took minutes to develop--much longer than would be expected in a low temperature superconducting coil. The quench behaved more like a spreading and continuous heating of an increasingly larger partially resistive section of the coil than like a sequential normal front propagation.

Lue, J.W.; Lubell, M.S. [Oak Ridge National Lab., TN (United States)] [Oak Ridge National Lab., TN (United States); Aized, D.; Campbell, J.M.; Schwall, R.E. [American Superconductor Corp., Westborough, MA (United States)] [American Superconductor Corp., Westborough, MA (United States)

1996-07-01T23:59:59.000Z

109

Meetings & Workshops | Superconducting Magnet Division  

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

Meetings & Workshops Meetings & Workshops S&T Committee Program Review June 22 - 23, 2006 Second Annual VLHC Meeting October 16 - 18, 2000 Workshop on the Effect of Synchrotron Radiation in the VLHC September 18 - 20, 2000 Proceedings of the 1968 Summer Study on Superconducting Devices and Accelerators Upcoming Events JAN 17 Friday East Coast Conference for Undergraduate Women in Physics - Lecture "The Nation's Nuclear Physics Program and the Role of the Government" Presented by Dr. Jehanne Gillo, U.S. Department of Energy, Nuclear Physics 9:30 am, Berkner Hall Auditorium Friday, January 17, 2014, 9:30 am Hosted by: Director's Office JAN 22 Wednesday Brookhaven Lecture "491st Brookhaven Lecture: Juergen Thieme of Photon Sciences Directorate" Presented by Juergen Thieme, Brookhaven Lab's Photon Sciences Directorate

110

J-PARC Correctors | Superconducting Magnet Division  

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

Interconnect Corrector Magnet Interconnect Corrector Magnet The design of these steering correction magnets has them being placed in the interconnect regions between the cable magnets. Since they are located in a vacuum, they will not be in direct contact with the helium cooling flow, but instead, require cooling be done through conduction. corrector tube Figure 8. To aid in heat transfer, the corrector tube is machined entirely out of copper. coil pattern Figure 9. To maximize the operating thermal margin, the coil pattern comes within 10 mm of the end flanges. This required making the end flanges as separate parts, to be attached after winding. support tube is insulated Figure 10. After the support tube is insulated with Kapton insulation, it is covered with the b stage fiberglass winding substrate, mounted to the

111

National High Magnetic Field Laboratory: Superconducting Wire  

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

of the particles has an effect on the pinning along various directions of magnetic field lines. The conductive capacity of 2G HTS wire is similarly affected by the...

112

Radiation-effects limits on copper in superconducting magnets  

SciTech Connect (OSTI)

The determination of the response of copper stabilizers to neutron irradiation in fusion-reactor superconducting magnets requires information in four areas: (1) neutron flux and spectrum determination, (2) resistivity changes at zero field, (3) resistivity changes at field, and (4) the cyclic irradiation and annealing. Applications of our current understanding of the limits of copper stabilizers in fusion-reactor designs are explored in two examples. Recommendations for future additions to the data base are discussed.

Guinan, M.W.

1983-05-25T23:59:59.000Z

113

Second generation high-temperature superconducting solenoid coils and energy storage.  

E-Print Network [OSTI]

??One of the most promising applications of superconductors is in Superconducting Magnetic Energy Storage (SMES) systems, which are becoming the enabling engines for improving the… (more)

Baiej, Hanan Tahir

2013-01-01T23:59:59.000Z

114

Frustrated phase separation and high temperature superconductivity  

SciTech Connect (OSTI)

A dilute system of neutral holes in an antiferromagnet separates into a hole-rich and a hole-poor phase. The phase separation is frustrated by long-range Coulomb interactions but, provided the dielectric constant is sufficiently large, there remain large-amplitude low-energy fluctuations in the hole density at intermediate length scales. The extensive experimental evidence showing that this behavior giver, a reasonable picture of high temperature superconductors is surveyed. Further, it is shown that the scattering of mobile holes from the local density fluctuations may account for the anomalous normal-state properties of high temperature superconductors and also provide the mechanism of pairing.

Emery, V.J. [Brookhaven National Lab., Upton, NY (United States); Kivelson, S.A. [California Univ., Los Angeles, CA (United States). Dept. of Physics

1992-09-01T23:59:59.000Z

115

Frustrated phase separation and high temperature superconductivity  

SciTech Connect (OSTI)

A dilute system of neutral holes in an antiferromagnet separates into a hole-rich and a hole-poor phase. The phase separation is frustrated by long-range Coulomb interactions but, provided the dielectric constant is sufficiently large, there remain large-amplitude low-energy fluctuations in the hole density at intermediate length scales. The extensive experimental evidence showing that this behavior giver, a reasonable picture of high temperature superconductors is surveyed. Further, it is shown that the scattering of mobile holes from the local density fluctuations may account for the anomalous normal-state properties of high temperature superconductors and also provide the mechanism of pairing.

Emery, V.J. (Brookhaven National Lab., Upton, NY (United States)); Kivelson, S.A. (California Univ., Los Angeles, CA (United States). Dept. of Physics)

1992-01-01T23:59:59.000Z

116

Scientific Image Gallery from the Applied Superconductivity Center at the National High Magnetic Field Laboratory  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

The Applied Superconductivity Center (ASC) is nested with the National High Magnetic Field Laboratory. Originally located at the University of Wisconsin, ASC transferred to NHMFL or Magnet Lab in 2003. ASC investigates both low and high-temperature materials. Focus areas include grain boundaries; coated conductors, BSCCO, and a new superconductor known as MgB2. The ASC Image Gallery provides graphs with text descriptions and single images with captions. The single images are organized into collections under scientific titles, such as MgB2 mentioned above. Click on the Videos link to see two 3D videos and be sure to check out the link to image collections at other organizations performing superconductivity research.

117

BEPC-II Magnet Project | Superconducting Magnet Division  

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

BEPC-II Magnet Project BEPC-II Magnet Project Project Overview The BEPC-II magnets are Interaction Region magnets to be used as part of an upgrade to the Beijing Electron Positron Collider. Two magnets will be produced, both of which will be inserted within the solenoidal detector at one of the collision points. Since the best use of the quadrupole focusing in this case requires placing the magnet as close to the collision point as possible, these magnets will be used within the magnetic field of the detector. This constrains the materials that can be used for construction to only non-magnetic materials. It also places severe demands on the structure of the magnet and it's holding supports due to the reaction forces between the solenoid and the magnet. To create the coil pattern for the final magnet, the coils will be

118

Acoustic microscopy for characterization of high?temperature superconducting tape  

Science Journals Connector (OSTI)

Although material scientists constantly discover superconducting compounds with higher critical temperatures (T c ’s) manufacturing of the high?temperature superconductors(HTS) remains a problem and long lengths (>1 mile) have yet to be produced. In an effort to produce long length superconductors manufacturing steps for HTS tape production have been critically looked at to find their effects in producing tape with the desired characteristics. In support of determining superconducting tapecharacteristics acoustic microscopy offers the potential for internal microstructural material characterization. This research will ultimately support in?process monitoring of HTSmanufacturing as part of an advanced sensing system to determine the presence of defects and/or the effects of process variables on the HTS tape. This presentation will overview scanning acoustic microscopy and present images of HTS tape at several frequencies ranging from 50 to 500 MHz. The results clearly demonstrate the feasibility of determining the Ag/ceramic interface location and the general integrity of the constituents.

Chiaki Miyasaka; Chris Cobucci; Bernhard Tittmann

1997-01-01T23:59:59.000Z

119

Operation of 17. 5 T superconducting magnet system in the last 8 years  

SciTech Connect (OSTI)

A 17.5 T hybrid superconducting magnet with an outer Nb/sub 3/Sn section and an inner V/sub 3/Ga section was installed at National Research Institute for Metals (Japan) at the beginning of 1976. Since then the magnet system has been successfully operated about 60 times without any trouble. The magnet still generates the world-highest field in the superconducting state. Ordinarily, it is cooled from room temperature down to about 15 K using two helium refrigerators with a total refrigeration power of 750 W at 20 K. For one day operation, about 120 liters of liquid is transfered into the cryostat. It requires about 2 hours to induce the magnetic field from 0 to 17.5 T. The liquid helium evaporation rate is about 4.5 liters/hr when the magnet is in full operation. To suppress the instability due to the tape movement, it was necessary to refasten tie-rods between the upper and lower flanges of the magnet during the first few years after the installation. The magnet has been effectively used to measure the critical current of newly developed high-field superconductors.

Tachikawa, K.; Asano, T.; Iijima, Y.; Inove, K.; Itoh, K.; Tanaka, Y.

1985-03-01T23:59:59.000Z

120

Status of the SSC superconducting magnet program  

SciTech Connect (OSTI)

The work that has been done on the SSC dipole over the past year is summarized in this paper, which is divided into four sections: cable development and production, cryostat design, cold mass design, and model magnet testing. 13 refs., 2 figs., 7 tabs.

Peoples, J.

1988-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Design and current-limiting simulation of magnetic-shield type superconducting fault current limiter with high-Tc superconductors  

SciTech Connect (OSTI)

The continuous development of electric power utilities has led to the increase in the problems concerning fault currents. The use of fault current limiters, which suppress fault currents below a prescribed level, has been examined in many places. The authors have studied a superconducting fault current limiter that is based on the magnetic shielding effect of superconductors. In this paper, the authors derive a requirement for leading to a flux-jumping inside a ceramic superconductor at liquid nitrogen temperature. Next, two kinds of magnetic-shield type superconducting fault current limiters are designed, and their current-limiting simulations are tried using a computer.

Kajikawa, K.; Kaiho, K.; Tamada, N. [Electrotechnical Lab., Tsukuba, Ibaraki (Japan)] [Electrotechnical Lab., Tsukuba, Ibaraki (Japan); Onishi, T. [Hokkaido Univ., Sapporo (Japan)] [Hokkaido Univ., Sapporo (Japan)

1996-07-01T23:59:59.000Z

122

J-PARC Correctors | Superconducting Magnet Division  

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

Combined Function Magnet Combined Function Magnet Both of the coil designs are two layer serpentine designs using "six around one" cable. The skew dipole is the first coil to be wound as it is the simplest from a coding and e/m analysis point of view. skew dipole nearing completion Figure 1 shows the first layer of the skew dipole nearing completion. Of note is the lack of harmonic correction spacers within the body of the coil. This is made possible by the the two step wiring process, which allows the two layers of the coil to be entirely independent of each other. Previously, the nested wire type of design locked the second layer of the coil into the same pattern already established on the first. By isolating each, it is now possible to eliminate the harmonic error correction

123

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

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

Superconducting Cable Winding Tests Superconducting Cable Winding Tests To increase the transfer function, a 6 around 1 cable was next used. This cable is more efficient because it allows the packing of more conductor within the volume surrounding the support tube. This also lowers the inductance of the coil, making quench protection easier, but requires a higher operating current. Traded off is the minimum radius of curvature that can be tolerated by the bonding process as well as the insulation integrity. For this test, the first layer was designed for a length of 8 inches, and the second layer is 6 inches long. The lengths were chosen to allow inspection of the different features which were designed in. The pole spacers on the first layer for this test were chosen to be solid copper wire, instead of the standard G-10 spacer. The copper allows for a

124

Accurate estimates for magnetic bottles in connection with superconductivity  

E-Print Network [OSTI]

Motivated by the theory of superconductivity and more precisely by the problem of the onset of superconductivity in dimension two, many papers devoted to the analysis in a semi-classical regime of the lowest eigenvalue of the Schr\\"odinger operator with magnetic field have appeared recently. Here we would like to mention the works by Bernoff-Sternberg, Lu-Pan, Del Pino-Felmer-Sternberg and Helffer-Morame and also Bauman-Phillips-Tang for the case of a disc. In the present paper we settle one important part of this question completely by proving an asymptotic expansion to all orders for low-lying eigenvalues for generic domains. The word `generic' means in this context that the curvature of the boundary of the domain has a unique non-degenerate maximum.

S. Fournais; B. Helffer

2004-11-16T23:59:59.000Z

125

Transformer current sensor for superconducting magnetic coils  

DOE Patents [OSTI]

The present invention is a current transformer for operating currents larger than 2kA (two kiloamps) that is capable of detecting a millivolt level resistive voltage in the presence of a large inductive voltage. Specifically, the present invention includes substantially cylindrical primary turns arranged to carry a primary current and substantially cylindrical secondary turns arranged coaxially with and only partially within the primary turns, the secondary turns including an active winding and a dummy winding, the active and dummy windings being coaxial, longitudinally separated and arranged to mutually cancel voltages excited by commonly experienced magnetic fields, the active winding but not the dummy winding being arranged within the primary turns.

Shen, S.S.; Wilson, C.T.

1985-04-16T23:59:59.000Z

126

A Superconducting Magnet Upgrade of the ATF2 Final Focus  

SciTech Connect (OSTI)

The ATF2 facility at KEK is a proving ground for linear collider technology with a well instrumented extracted beam line and Final Focus (FF). The primary ATF2 goal is to demonstrate the extreme beam demagnification and spot stability needed for a linear collider FF. But the ATF2 FF uses water cooled magnets and the ILC baseline has a superconducting (SC) FF. We plan to upgrade ATF2 and replace some of the warm FF magnets with SC FF magnets. The ATF2 SC magnets, like the ILC FF, will made via direct wind construction. ATF2 coil winding is in progress at BNL and warm magnetic measurements indicate we have achieved good field quality. Studies indicate that having ATF2 FF magnets with larger aperture and better field quality should allow reducing the ATF2 FF beta function for study of focusing regimes relevant to CLIC. The ATF2 magnet cryostat will have laser view ports for directly monitoring cold mass movement. We plan to make stability measurements at BNL and KEK to relate ATF2 FF magnet performance to that of a full length ILC QD0 R and D FF prototype under construction at BNL.

Parker B.; Anerella M.; Escallier J.; He P.; Jain A.; Marone A.; Wanderer P.; Wu K.C.; Hauviller C.; Marin E.; Tomas R.; Zimmermann F.; Bolzon B.; Jeremie A.; Kimura N.; Kubo K.; Kume T.; Kuroda S.; Okugi T.; Tauchi T.; Terunuma N.; Tomaru T.; Tsuchiya K.; Urakawa J.; Yamamoto A.; Bambabe P.; Coe P.; Urner D.; Seryi A.; Spencer C.; White G.

2010-05-23T23:59:59.000Z

127

A Superconducting Magnet Upgrade of the ATF2 Final Focus  

SciTech Connect (OSTI)

The ATF2 facility at KEK is a proving ground for linear collider technology with a well instrumented extracted beam line and Final Focus (FF). The primary ATF2 goal is to demonstrate the extreme beam demagnification and spot stability needed for a linear collider FF. But the ATF2 FF uses water cooled magnets and the ILC baseline has a superconducting (SC) FF. We plan to upgrade ATF2 and replace some of the warm FF magnets with SC FF magnets. The ATF2 SC magnets, like the ILC FF, will made via direct wind construction. ATF2 coil winding is in progress at BNL and warm magnetic measurements indicate we have achieved good field quality. Studies indicate that having ATF2 FF magnets with larger aperture and better field quality should allow reducing the ATF2 FF beta function for study of focusing regimes relevant to CLIC. The ATF2 magnet cryostat will have laser view ports for directly monitoring cold mass movement. We plan to make stability measurements at BNL and KEK to relate ATF2 FF magnet performance to that of a full length ILC QD0 R&D FF prototype under construction at BNL.

Parker, Brett; /Brookhaven; Anerella, Michael; /Brookhaven; Escallier, John; /Brookhaven; He, Ping; /Brookhaven; Jain, Animesh; /Brookhaven; Marone, Andrew; /Brookhaven; Wanderer, Peter; /Brookhaven; Wu, Kuo-Chen; /Brookhaven; Bambade, Philip; /Orsay, LAL; Bolzon, Benoit; /Annecy, LAPP; Jeremie, Andrea; /Annecy, LAPP; Coe, Paul; /Oxford U.; Urner, David /Oxford U.; Hauviller, Claude; /CERN; Marin, Eduardo; /CERN; Tomas, Rogelio; /CERN; Zimmermann, Frank; /CERN; Kimura, Nobuhiro; /KEK, Tsukuba; Kubo, Kiyoshi; /KEK, Tsukuba; Kume, Tatsuya /KEK, Tsukuba; Kuroda, Shigeru; /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /KEK, Tsukuba /SLAC /SLAC /SLAC

2012-07-05T23:59:59.000Z

128

Effect of magnetic field on the photon detection in thin superconducting meander structures  

Science Journals Connector (OSTI)

We have studied the influence of an externally applied magnetic field on the photon and dark count rates of meander-type niobium nitride superconducting nanowire single-photon detectors. Measurements have been performed at a temperature of 4.2 K, and magnetic fields up to 250 mT have been applied perpendicularly to the meander plane. While photon count rates are field independent at weak applied fields, they show a strong dependence at fields starting from approximately ±25 mT. This behavior, as well as the magnetic field dependence of the dark count rates, is in good agreement with the recent theoretical model of vortex-assisted photon detection and spontaneous vortex crossing in narrow superconducting lines. However, the local reduction of the superconducting free energy due to photon absorption, which is the fitting parameter in the model, increases much slower with the photon energy than the model predicts. Furthermore, changes in the free-energy during photon counts and dark counts depend differently on the current that flows through the meander. This indicates that photon counts and dark counts occur in different parts of the meander.

R. Lusche; A. Semenov; Y. Korneeva; A. Trifonov; A. Korneev; G. Gol'tsman; H.-W. Hübers

2014-03-19T23:59:59.000Z

129

Bio-Med Variable Field MRI Project | Superconducting Magnet Division  

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

Bio-Med Variable Field MRI Project Bio-Med Variable Field MRI Project One of the Research and Development projects currently underway is the Bio-Med magnet. Destined for use within the solenoidal field of an MRI, it is designed for use where the subject, in this case a rat, must be tracked in order to obtain an image. Typical MRIs require the subject to remain stationary, and a rat will not normally oblige when it is awake. By moving the composite field (MRI Solenoid plus Bio-Med dipole) to track the rat, it is possible to allow the rat some freedom of motion, while still imaging the brain functions. For the rapid movement typical of a rat, the Bio-Med coil magnet must be capable of very rapid changes in field. Superconducting magnets are typically not designed to allow rapid field variations. To do so typically

130

Voltage spike detection in high field superconducting accelerator magnets  

SciTech Connect (OSTI)

A measurement system for the detection of small magnetic flux changes in superconducting magnets, which are due to either mechanical motion of the conductor or flux jump, has been developed at Fermilab. These flux changes are detected as small amplitude, short duration voltage spikes, which are {approx}15mV in magnitude and lasts for {approx}30 {micro}sec. The detection system combines an analog circuit for the signal conditioning of two coil segments and a fast data acquisition system for digitizing the results, performing threshold detection, and storing the resultant data. The design of the spike detection system along with the modeling results and noise analysis will be presented. Data from tests of high field Nb{sub 3}Sn magnets at currents up to {approx}20KA will also be shown.

Orris, D.F.; Carcagno, R.; Feher, S.; Makulski, A.; Pischalnikov, Y.M.; /Fermilab

2004-12-01T23:59:59.000Z

131

Quench development in a high temperature superconducting tape  

SciTech Connect (OSTI)

Normal zone propagation experiments have been performed on a long length of Bi-2223/Ag high temperature superconducting (HTS) tape. Tests were conducted with liquid nitrogen and gaseous helium cooling in temperatures from 5 to 77 K. No sustained expansion of a {open_quotes}normal{close_quotes} zone was observed with a short resistive heater. Non-uniform critical currents were, however, observed over the length of the conductor. When the conductor was charged and held at a current above the critical currents of weaker sections, a quench was being developed without distinctive {open_quotes}normal{close_quotes} zone propagation. Because of the high temperature margin and broad resistive transition of the superconductor, and the good thermal conductivity of the Ag-matrix, the quench process was very slow. and no large temperature gradient along the conductor was observed.

Lue, J.W.; Lubell, M.S. [Oak Ridge National Lab., TN (United States); Aized, D.; Campbell, J.M.; Schwall, R.E. [American Superconductor Corporation, Westborough, MA (United States)

1996-12-31T23:59:59.000Z

132

Quench development in a high temperature superconducting tape  

SciTech Connect (OSTI)

Normal zone propagation experiments have been per-formed on a long length of Bi2223/Ag high temperature superconducting (HTS) tape. Tests were performed in liquid nitrogen and with gaseous helium cooling in temperatures ranging from 4.2 K to 77 K. No sustained expansion of a ``normal`` zone was observed with a short resistive heater. Non-uniform critical currents were, however, observed over the length of the conductor. When the conductor was charged and held at a current above the critical currents of weaker sections, a quench was being developed without distinctive ``normal`` zone propagation. Because of the high temperature margin and broad resistive transition of the superconductor, and the good thermal conductivity of the Ag-matrix, the quench process was very slow, and no large temperature gradient along the conductor was observed in the test duration of a few minutes.

Lue, J.W.; Lubell, M.S. [Argonne National Lab., IL (United States); Aized, D.; Campbell, J.M.; Schwall, R.E. [American Superconductor Corp., Westborough, MA (United States)

1995-12-01T23:59:59.000Z

133

Magnetism and superconductivity in Sr YRu Cu O and magnetism in Ba GdRu Cu O  

Science Journals Connector (OSTI)

We report magnetization, surface resistance ( ), and electron spin resonance (ESR) for non-superconducting Ba2GdRu1-uCuuO6, and find that all three magnetic ions (Gd, Ru, and Cu...

H.A. Blackstead; John D. Dow; D.R. Harshman…

2000-06-01T23:59:59.000Z

134

A Method for the High Energy Density SMES—Superconducting Magnetic Energy Storage  

Science Journals Connector (OSTI)

The energy density of superconducting magnetic energy storage (SMES), 107 [J/m3] for the average magnetic field 5T is rather small compared with that of batteries which are estimated as 108 [J/m3...]. This paper ...

Y. Mitani; Y. Murakami

1990-01-01T23:59:59.000Z

135

Use of Superconducting Magnet Technology for Astronaut Radiation Protection PI: Jeffery Hoffman, MIT  

E-Print Network [OSTI]

Use of Superconducting Magnet Technology for Astronaut Radiation Protection PI: Jeffery Hoffman of radiation from cosmic rays. The proposed superconducting magnetic radiation shielding system could a conceptual systems design. In Phase II, we plan to extend the shielding studies to a detailed comparison

Shepherd, Simon

136

A design flux injector for NMR superconducting magnets : results of operation with superconducting insert cells  

E-Print Network [OSTI]

It has been known for some time that high-temperature superconductors (HTS) are critical for the construction of NMR magnets generating 1 GHz and above. Such systems generally require an HTS insert to be placed in the inner ...

Mai, Rocky D. (Rocky Dikang)

2006-01-01T23:59:59.000Z

137

At the Boundary between Superconducting and Magnetic Oxides  

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

At the Boundary between Superconducting and Magnetic Oxides The transistor, which shaped so much of our modern technology and economics, grew out of scientists' desire to gain a greater understanding of the interfaces between different materials. In the same way, today's materials scientists seek to expand our understanding of complex oxides by creating new states at the interface of two materials. Novel growth of complex oxides provides the ability to combine different materials with different and often antagonistic order parameters to create novel, strongly correlated states at the interface. As shown in the article, " Magnetism at the interface between ferromagnetic and superconducting oxides " in the April 2006 issue of Nature Physics, element-resolved x-ray probes and neutrons can be used to construct the first microscopic picture of interactions in a La[subscript 0.7]Ca[subscript 0.3]MnO[subscript 3]/YBa[subscript 2]Cu[subscript 3]O[subscript 7-x] superlattice.

138

High-field, high-current-density, stable superconducting magnets for fusion machines  

SciTech Connect (OSTI)

Designs for large fusion machines require high-performance superconducting magnets to reduce cost or increase machine performance. By employing force-flow cooling, cable-in-conduit conductor configuration, and NbTi superconductor, it is now possible to design superconducting magnets that operate a high fields (8-12 T) with high current densities (5-15 kA/cm/sup 2/ over the winding pack) in a stable manner. High current density leads to smaller, lighter, and thus less expensive coils. The force-flow cooling provides confined helium, full conductor insulation, and a rigid winding pack for better load distribution. The cable-in-conduit conductor configuration ensures a high stability margin for the magnet. The NbTi superconductor has reached a good engineering material standard. Its strain-insensitive critical parameters are particularly suitable for complex coil windings of a stellarator machine. The optimization procedure for such a conductor design, developed over the past decade, is summarized here. If desired a magnet built on the principles outlines in this paper can be extended to a field higher than the design value without degrading its stability by simply lowering the operating temperature below 4.2 K. 11 refs., 3 figs.

Lue, J.W.; Dresner, L.; Lubell, M.S.

1989-01-01T23:59:59.000Z

139

Magnetism and superconductivity in RPtSi (R=La, Ce, Nd, and Sm)  

Science Journals Connector (OSTI)

Although many studies have been made on the nonmagnetic heavy fermion CePtSi belonging to the ?-ThSi2 structure, to the best of our knowledge no studies have been reported in the other rare-earth members of this series. In this paper, we report our resistivity, magnetization, and heat-capacity studies on NdPtSi and SmPtSi. We have established bulk antiferromagnetic ordering in NdPtSi below 3.8 K and ferromagnetic ordering in SmPtSi below 15 K. The heat-capacity studies show large contribution from the crystal-field effects. We have also established bulk superconductivity below 3.8 K in LaPtSi from resistivity, susceptibility, and heat-capacity studies. A detailed study of the influence of paramagnetic impurities (Nd and Ce) on the superconductivity of LaPtSi has been made. From this study, we are able to show that the superconducting transition temperature (Tc) decreases with the substitution of Nd impurities and this can be explained using Abrikosov and Gor’kov theory. On the other hand, Ce impurities show large depression of Tc which we ascribe to the Kondo effect due to Ce aotms with the Kondo temperature, Tk?0.25Tc. The observed data have been analyzed using recent quantum Monte Carlo calculations by Jarrel for superconductors with arbitrary Tk values.

S. Ramakrishnan; K. Ghosh; Arvind D. Chinchure; V. R. Marathe; Girish Chandra

1995-09-01T23:59:59.000Z

140

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

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

Two Layer Quadrupole Shielding Coil Two Layer Quadrupole Shielding Coil Near the interaction region if the ILC, the exit beam by design, is very close to the final focus quads, and is sensitive to the external field of the quads. To eliminate this effect and prevent disruption of the exiting beams, a two layer shielding quadrupole has been designed and wound. For simplicity as well as efficiency, the transfer function of this coilset has been designed to allow series connection of the focus quad with this outer shield coilset. The completed magnet will be finished with G-10 fillers, voltage taps and heaters will be added, blue epoxy filling for all interstitial spaces, and then the magnet will be wrapped with glass cloth and fiberglass roving, then cured. Once cured, this magnet will be capable of full power operation

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Thermodynamic Critical Field and Superconducting Fluctuation of Vortices for High Temperature Cuprate Superconductor: La-214  

SciTech Connect (OSTI)

Thermodynamics has been studied systematically for the high temperature cuprate superconductor La{sub 2-x}Sr{sub x}CuO{sub 4-{delta}}, La-214, in the entire superconductive region from strongly underdoped to strongly overdoped regimes. Magnetization studies with H{parallel}c have been made in order to investigate the changes in free energy of the system as the number of carriers is reduced. Above the superconducting transition temperature, the normal-state magnetization exhibits a two-dimensional Heisenberg antiferromagnetic behavior. Below T{sub c}, magnetization data are thermodynamically reversible over large portions of the H-T plane, so the free energy is well defined in these regions. As the Sr concentration is varied over the wide range from 0.060 (strongly underdoped) to 0.234 (strongly overdoped), the free energy change goes through a maximum at the optimum doped in a manner similar to the T{sub c0} vs. x curve. The density of states, N(0), remains nearly constant in the overdoped and optimum doped regimes, taking a broad maximum around x = 0.188, and then drops abruptly towards zero in the underdoped regime. The La{sub 2-x}Sr{sub x}CuO{sub 4} (La-214) system displays the fluctuating vortex behavior with the characteristic of either 2D or 3D fluctuations as indicated by clearly identifiable crossing points T* close to T{sub c}. The dimensional character of the fluctuations depends on both applied magnetic fields and the density of charge carriers. The dimensional crossover from 2D to 3D occurs in the strongly underdoped regime when the c-axis coherence distance {zeta}{sub c} becomes comparable to the spacing between adjacent CuO{sub 2} layers s at sufficiently high magnetic fields near H{sub c2}.

Yung Moo Huh

2001-05-01T23:59:59.000Z

142

Thermodynamic Critical Field and Superconducting Fluctuation of Vortices for High Temperature Cuprate Superconductor: La-214  

SciTech Connect (OSTI)

Thermodynamics has been studied systematically for the high temperature cuprate superconductor La{sub 2-x}Sr{sub x}CuO{sub 4-{delta}}, La-214, in the entire superconductive region from strongly underdoped to strongly overdoped regimes. Magnetization studies with H {parallel} c have been made in order to investigate the changes in free energy of the system as the number of carriers is reduced. Above the superconducting transition temperature, the normal-state magnetization exhibits a two-dimensional Heisenberg antiferromagnetic behavior. Below T{sub c}, magnetization data are thermodynamically reversible over large portions of the H-T plane, so the free energy is well defined in these regions. As the Sr concentration is varied over the wide range from 0.060 (strongly underdoped) to 0.234 (strongly overdoped), the free energy change goes through a maximum at the optimum doped in a manner similar to the T{sub c0} vs. x curve. The density of states, N(0), remains nearly constant in the overdoped and optimum doped regimes, taking a broad maximum around x = 0.188, and then drops abruptly towards zero in the underdoped regime. The La{sub 2-x}Sr{sub x}CuO{sub 4} (La-214) system displays the fluctuating vortex behavior with the characteristic of either 2D or 3D fluctuations as indicated by clearly identifiable crossing points T* close to T{sub c}. The dimensional character of the fluctuations depends on both applied magnetic fields and the density of charge carriers. The dimensional crossover from 2D to 3D occurs in the strongly underdoped regime when the c-axis coherence distance {xi}{sub c} becomes comparable to the spacing between adjacent CuO{sub 2} layers s at sufficiently high magnetic field near H{sub c2}.

Douglas K. Finnemore

2001-06-25T23:59:59.000Z

143

Test of two prototype high-temperature superconducting transmission cables  

SciTech Connect (OSTI)

Two 500-A class prototype high-temperature superconducting cables have been constructed by Southwire Company and tested at Oak Ridge National Laboratory (ORNL). In the first cable, no insulation was used to separate the individual HTS tapes. In the second cable, Kapton tape was used to insulate the HTS tapes between successive layers for the study of AC loss and current distribution. The cables were tested with both DC and AC currents in liquid nitrogen from 77 to 69 K. Both cables achieved DC critical current, I{sub c} greater than 500 A. A calorimetric technique that measures the cable temperature rise under ac currents was used to measure the ac loss of the cables. The un-insulated cable showed a cryoresistive behavior under the 60 Hz AC currents. The insulated cable started to show measurable loss at current where there was corresponding resistive loss.

Lue, J.W.; Lubell, M.S.; Kroeger, D.M.; Martin, P.M. [Oak Ridge National Lab., TN (United States); Demko, J.A.; Jones, E.C. [Oak Ridge Associated Universities, Inc., TN (United States); Sinha, U.; Hughey, R.L. [Southwire Co., Carrollton, GA (United States)

1996-10-01T23:59:59.000Z

144

Magnetic Energy Storage System: Superconducting Magnet Energy Storage System with Direct Power Electronics Interface  

SciTech Connect (OSTI)

GRIDS Project: ABB is developing an advanced energy storage system using superconducting magnets that could store significantly more energy than today’s best magnetic storage technologies at a fraction of the cost. This system could provide enough storage capacity to encourage more widespread use of renewable power like wind and solar. Superconducting magnetic energy storage systems have been in development for almost 3 decades; however, past devices were designed to supply power only for short durations—generally less than a few minutes. ABB’s system would deliver the stored energy at very low cost, making it ideal for eventual use in the electricity grid as a costeffective competitor to batteries and other energy storage technologies. The device could potentially cost even less, on a per kilowatt basis, than traditional lead-acid batteries.

None

2010-10-01T23:59:59.000Z

145

Modified magnetism within the coherence volume of superconducting FeSeTe  

SciTech Connect (OSTI)

Neutron Scattering is used to probe magnetic interactions as superconductivity develops in opti- mally doped Fe_(1+ )Se_xTe_(1 x). Applying the first moment sum-rule to comprehensive neutron scatter- ing data, we extract the change in magnetic exchange energy [J_(R-R ) S_R S_R ] in the superconducting state referenced to the normal state. Oscillatory changes are observed for Fe-Fe displacements | R| < , where = 1.3(1) nm is the superconducting coherence length. Dominated by a large reduction in the second nearest neighbor exchange energy (-1.2(2) meV/Fe), the overall reduction in magnetic interaction energy is Hmag = 0.31(9) meV/Fe. Comparison to the superconducting condensation energy E_sc = 0.013(1) meV/Fe, which we extract from specific heat data, suggests the modified magnetism we probe drives superconductivity in Fe_(1+ )Se_xTe_(1 x)

Leiner, Jonathan C [ORNL; Thampy, Vivek [ORNL; Christianson, Andrew D [ORNL; Abernathy, D. [Oak Ridge National Laboratory (ORNL); Stone, Matthew B [ORNL; Lumsden, Mark D [ORNL; Sales, Brian C [ORNL; Safa-Sefat, Athena [ORNL; Hu, Jin [Tulane University; Mao, Zhiqiang [Tulane University; Bao, Wei [Renmin University of China; Broholm, Collin L [ORNL

2014-01-01T23:59:59.000Z

146

Development of Superconducting Materials for Use in Magnet Applications: Nb3Sn Flux Pinning and Bi-2212 Magnetic Texturing  

E-Print Network [OSTI]

DEVELOPMENT OF SUPERCONDUCTING MATERIALS FOR USE IN MAGNET APLICATIONS: Nb3Sn FLUX PINING AND Bi-212 MAGNETIC TEXTURING Major: Physics April 2010 Submitted to the Office of Undergraduate Research Texas A&M University... in partial fulfillment of the requirements for the designation as UNDERGRADUATE RESEARCH SCHOLAR A Senior Scholars Thesis by DAVID GABRIEL RAHMANI DEVELOPMENT OF SUPERCONDUCTING MATERIALS FOR USE IN MAGNET APLICATIONS: Nb3Sn FLUX...

Rahmani, David G.

2010-07-14T23:59:59.000Z

147

HERA Luminosity Upgrade Magnet Production | Superconducting Magnet Division  

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

HERA Luminosity Upgrade Magnet Production HERA Luminosity Upgrade Magnet Production Photos taken on or before 12-May-2000. GO horizontal test setup GO horizontal test setup view toward lead tower GO horizontal test setup GO horizontal test setup GO horizontal test setup GO horizontal test setup GO horizontal test setup GO horizontal test setup GO horizontal test setup GO horizontal test setup GO horizontal test setup GO horizontal test setup lead tower feedthroughs Close up of lead tower feedthroughs lead tower feedthroughs Close up of lead tower feedthroughs lead tower feedthroughs Close up of lead tower feedthroughs GO horizontal test setup GO horizontal test setup GO horizontal test setup GO horizontal test setup GO Coldmass GO Coldmass GO sextupole coil GO sextupole coil GO quadrupole coil lead end GO quadrupole coil lead end

148

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

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

Six Layer Quadrupole Six Layer Quadrupole The incoming beam final quad for the linear collider 20 mr option requires a gradient of 140 T/m within a solenoid of 3 Tesla. To meet this goal, a design using 6 around 1 cable bonded to a one inch diameter tube was used. The magnet design required 6 layers of this cable. Two layers were bonded at a time, with S-glass compression wrap every two layers. Final cold testing results were very good, with only two training quenches before reaching short sample. Initial test results at a glance: Background Field Tesla Temp Kelvin Gradient T/m 3 4.3 158 4 4.22 139 5 4.22 134 6 3 137 This data scales to 232 Tesla/meter at 1.9 Kelvin in a 3 Tesla background field. Present field requirements for the 20 mr IR represents 60% of the magnet capability, a comfortable margin. Indeed, even at 4.3 Kelvin in a 3

149

Test results of two high temperature superconducting sample coils  

SciTech Connect (OSTI)

Electrical measurements have been performed on two high temperature superconducting coils made by American Superconductor Corporation. One coil measured 24-mm ID, 59-mm OD, 50-mm long, and used 85-m long Y-124 tape conductor. The other coil measured 29-mm ID, 44-mm OD, 43-mm long, and used 35-m long Bi-2223 tape conductor. V-I curves were measured from room to helium temperature in a variable temperature cryostat cooled by helium gas in external fields up to 5 T. Without external field, the better performing Bi-2223 coil had a critical current, I{sub c} of 14.1 A (2820 A/cm{sup 2} over the conductor) at 4.2 K and 1.8 A (360 A/cm{sup 2}) at 77 K. At 5 T, I{sub c} was 4.9 A (980 A/cm{sup 2}) at 4.2 K and 2.0 A (400 A/cm{sup 2}) at 50 K. Reduced critical current, I{sub c}(B)/I{sub c}(0) vs field plots indicated that a single smooth curve could fit all the data of up to 50 K in temperature. The reduction in critical currents with external fields for the Y-124 coil was more than 80% at 1 T. For the Bi-2223 coil, it was about 38% at 1 T, and about 61% at 5 T.

Lue, J.W.; Schwenterly, S.W.; Lubell, M.S.; Luton, J.N. [Oak Ridge National Lab., TN (United States); Joshi, C.H.; Masur, L.J.; Podtburg, E.R. [American Superconductor Corp., Watertown, MA (United States)

1993-10-01T23:59:59.000Z

150

Development of light weight, high current density, superconducting magnets  

SciTech Connect (OSTI)

High field, high current density superconducting magnets can be achieved with force-cooled, cable-in-conduit conductors while maintaining good stability and structural integrity. The weight of the conductor was reduced by using aluminum instead of stainless steel for the conduit. A 1-km long al-conduit conductor was produced by continuous extrusion of Al-tube on the cable and then drawing to the final size and rectangular shape. The structural weight was further reduced by using carbon-fiber reinforced composite, instead of stainless steel. Small test coils with copper conduit were built first to test the above ideas and to measure the stability margins of a cable-in-conduit conductor with void fractions less than 30%, substantially lower than have been used elsewhere.

Lue, J.W.; Lubell, M.S.; Luton, J.N.; Frame, B.J.; Paulaskas, F.L.; Blake, H.W. [Oak Ridge National Lab., TN (United States)] [Oak Ridge National Lab., TN (United States)

1994-07-01T23:59:59.000Z

151

Shock-induced synthesis of high temperature superconducting materials  

DOE Patents [OSTI]

It has now been determined that the unique features of the high pressure shock method, especially the shock-induced chemical synthesis technique, are fully applicable to high temperature superconducting materials. Extraordinarily high yields are achievable in accordance with this invention, e.g., generally in the range from about 20% to about 99%, often in the range from about 50% to about 90%, lower and higher yields, of course, also being possible. The method of this invention involves the application of a controlled high pressure shock compression pulse which can be produced in any conventional manner, e.g., by detonation of a high explosive material, the impact of a high speed projectile or the effect of intense pulsed radiation sources such as lasers or electron beams. Examples and a discussion are presented.

Ginley, D.S.; Graham, R.A.; Morosin, B.; Venturini, E.L.

1987-06-18T23:59:59.000Z

152

BEPC-II Magnet Project | Superconducting Magnet Division  

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

Initial R&D Winding and Tests Initial R&D Winding and Tests To achieve the current densities required within the quad coils, it was decided to fabricate the magnet using coil pairs, with the S-glass compression applied after each double layer wind. Initial wiring tests were done using a nested pattern. second layer of conductor Figure 1 shows this pattern placed the second layer of conductor into the channel formed by the first layer wires, the end of a pole test. Note the ease with which the second layer wires dropped from the channel on the wires down to the substrate. While producing the highest packing factor in the straight section, it produces a variable height end. This end geometry does not allow a simple layer cover, but requires a very complex top piece. In addition, it does not allow for the simple addition of

153

Development of Industrially Produced Composite Quench Heaters for the LHC Superconducting Lattice Magnets  

E-Print Network [OSTI]

The quench heaters are vital elements for the protection of the LHC superconducting lattice magnets in the case of resistive transitions of the conductor. The basic concept of magnet protection and technical solutions are briefly presented. The quench heater consists of partially copper clad stainless steel strips sandwiched in between electric insulating carrier foils with electrical and mechanical properties such as to withstand high voltages, low temperatures, pressures and ionizing radiation. Testing of some commercial available electric insulation foils, polyimide (PI), polyetheretherketon (PEEK) and polyarylate (PA) and combinations of adhesive systems which are suitable for industrial processing are described. Possible industrial methods for series production for some 80 km of these composite quench heaters are indicated.

Szeless, Balázs; Calvone, F

1996-01-01T23:59:59.000Z

154

Cryogenic System for a High Temperature Superconducting Power Transmission Cable  

SciTech Connect (OSTI)

High-temperature superconducting (HTS) cable systems for power transmission are under development that will use pressurized liquid nitrogen to provide cooling of the cable and termination hardware. Southwire Company and Oak Ridge National Laboratory have been operating a prototype HTS cable system that contains many of the typical components needed for a commercial power transmission application. It is being used to conduct research in the development of components and systems for eventual commercial deployment. The cryogenic system was built by Air Products and Chemicals, Allentown, Pennsylvania, and can circulate up to 0.35 kg/s of liquid nitrogen at temperatures as low as 67 K at pressures of 1 to 10 bars. Sufficient cooling is provided for testing a 5-m-long HTS transmission cable system that includes the terminations required for room temperature electrical connections. Testing of the 5-m HTS transmission cable has been conducted at the design ac conditions of 1250 A and 7.5 kV line to ground. This paper contains a description of the essential features of the HTS cable cryogenic system and performance results obtained during operation of the system. The salient features of the operation that are important in large commercial HTS cable applications will be discussed.

Demko, J.A.; Gouge, M.J.; Hughey, R.L.; Lue, J.W.; Martin, R.; Sinha, U.; Stovall, J.P.

1999-07-12T23:59:59.000Z

155

Superconducting magnetic energy storage (SMES) program, January 1-December 31, 1981  

SciTech Connect (OSTI)

Work reported is on the development of a 30 MJ superconducting magnetic energy storage (SMES) unit for use by the Bonneville Power Administration (BPA) to stabilize power oscillations on their Pacific AC Intertie. The 30 MJ superconducting coil manufacture was completed. Design of the seismic mounting of the coil to the nonconducting dewar lid and a concrete foundation is complete. The superconducting application VAR (SAVAR) control study indicated a low economic advantage and the SAVAR program was terminated. An economic and technological evaluation of superconducting fault current limiter (SFCL) was completed and the results are reported.

Rogers, J.D. (comp.)

1982-02-01T23:59:59.000Z

156

Levitation Performance of Bulk High Temperature Superconductor Above the Permanent Magnet Guideway at Different Temperatures  

Science Journals Connector (OSTI)

The levitation performance of a high temperature superconducting (HTS) Maglev system was investigated at different temperatures for HTS Maglev vehicle application. Using a cryogenic measurement system, we stud...

Hua Jing; Suyu Wang; Ming Jiang; Jiasu Wang

2010-12-01T23:59:59.000Z

157

Ambient-Pressure Bulk Superconductivity Deep in the Magnetic State of CeRhIn5  

SciTech Connect (OSTI)

Specific heat, magnetic susceptibility and electrical transport measurements were performed at ambient pressure on high-quality single crystal specimens of CeRhIn5 down to ultra-low temperatures. We report signatures of an anomaly observed in all measured quantities consistent with a bulk phase transition to a superconducting state at T{sub c}=110 mK. Occurring far below the onset of antiferromagnetism at T{sub N}=3.8 K, this transition appears to involve a significant portion of the available low-temperature density of electronic states, exhibiting an entropy change in line with that found in other members of the 115 family of superconductors tuned away from quantum criticality.

Paglione,J.; Ho, P.; Maple, M.; Tanatar, M.; Taillefer, L.; Lee, Y.; Petrovic, C.

2008-01-01T23:59:59.000Z

158

Impact of oxygen annealing on the heat capacity and magnetic resonance of superconducting Pr0.88LaCe0.12CuO4?  

SciTech Connect (OSTI)

We use thermodynamic and neutron-scattering measurements to study the effect of oxygen annealing on the superconductivity and magnetism in Pr0.88LaCe0.12CuO4?. Although the transition temperature Tc measured by susceptibility and superconducting coherence length increases smoothly with gradual oxygen removal from the annealing process, bulk superconductivity, marked by a specific-heat anomaly at Tc and the presence of a neutron magnetic resonance, only appears abruptly when Tc is close to the largest value. These results suggest that the effect of oxygen annealing must first be determined in order to establish a Ce doping dependence of antiferromagnetism and superconductivity phase diagram for electron-doped copper oxides.

Li, Shiliang [University of Tennessee, Knoxville (UTK); Chi, Songxue [University of Tennessee, Knoxville (UTK); Zhao, Jun [ORNL; Wen, H. H. [Chinese Academy of Sciences; Stone, Matthew B [ORNL; Lynn, J. W. [National Institute of Standards and Technology (NIST); Dai, Pengcheng [ORNL

2008-01-01T23:59:59.000Z

159

What Causes High-temperature Superconductivity? | U.S. DOE Office of  

Office of Science (SC) Website

What Causes High-temperature Superconductivity? What Causes High-temperature Superconductivity? Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of BES Funding Opportunities Basic Energy Sciences Advisory Committee (BESAC) News & Resources Contact Information Basic Energy Sciences U.S. Department of Energy SC-22/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3081 F: (301) 903-6594 E: sc.bes@science.doe.gov More Information » March 2013 What Causes High-temperature Superconductivity? A phase change at absolute zero temperature may provide key insights into the decades-old mystery of high-temperature superconductivity. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo Image courtesy of Ames Laboratory

160

Fermi-surface reconstruction and the origin of high-temperature superconductivity.  

SciTech Connect (OSTI)

In crystalline lattices, the conduction electrons form waves, known as Bloch states, characterized by a momentum vector k. The defining characteristic of metals is the surface in momentum space that separates occupied from unoccupied states. This 'Fermi' surface may seem like an abstract concept, but it can be measured and its shape can have profound consequences for the thermal, electronic, and magnetic properties of a material. In the presence of an external magnetic field B, electrons in a metal spiral around the field direction, and within a semiclassical momentum-space picture, orbit around the Fermi surface. Physical properties, such as the magnetization, involve a sum over these orbits, with extremal orbits on the Fermi surface, i.e., orbits with minimal or maximal area, dominating the sum [Fig. 1(a)]. Upon quantization, the resulting electron energy spectrum consists of Landau levels separated by the cyclotron energy, which is proportional to the magnetic field. As the magnetic field causes subsequent Landau levels to cross through the Fermi energy, physical quantities, such as the magnetization or resistivity, oscillate in response. It turns out that the period of these oscillations, when plotted as a function of 1/B, is proportional to the area of the extremal orbit in a plane perpendicular to the applied field [Fig. 1(b)]. The power of the quantum oscillation technique is obvious: By changing the field direction, one can map out the Fermi surface, much like a blind man feeling an elephant. The nature and topology of the Fermi surface in high-T{sub c} cuprates has been debated for many years. Soon after the materials were discovered by Bednorz and Mueller, it was realized that superconductivity was obtained by doping carriers into a parent insulating state. This insulating state appears to be due to strong electronic correlations, and is known as a Mott insulator. In the case of cuprates, the electronic interactions force the electrons on the copper ion lattice into a d{sup 9} configuration, with one localized hole in the 3d shell per copper site. Given the localized nature of this state, it was questioned whether a momentum-space picture was an appropriate description of the physics of the cuprates. In fact, this question relates to a long-standing debate in the physics community: Since the parent state is also an antiferromagnet, one can, in principle, map the Mott insulator to a band insulator with magnetic order. In this 'Slater' picture, Mott physics is less relevant than the magnetism itself. It is therefore unclear which of the two, magnetism or Mott physics, is more fundamentally tied to superconductivity in the cuprates. After twenty years of effort, definitive quantum oscillations that could be used to map the Fermi surface were finally observed in a high-temperature cuprate superconductor in 2007. This and subsequent studies reveal a profound rearrangement of the Fermi surface in underdoped cuprates. The cause of the reconstruction, and its implication for the origin of high-temperature superconductivity, is a subject of active debate.

Norman, M. R.; Materials Science Division

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Magnetic and superconducting phase diagrams in ErNi2B2C  

SciTech Connect (OSTI)

We present measurements of the superconducting upper critical field Hc2(T) and the magneticphasediagram of the superconductor ErNi2B2C made with a scanning tunneling microscope (STM). The magnetic field was applied in the basal plane of the tetragonal crystal structure. We have found large gapless regions in the superconductingphasediagram of ErNi2B2C, extending between different magnetic transitions. A close correlation between magnetic transitions and Hc2(T) is found, showing that superconductivity is strongly linked to magnetism.

Galvis, J.A.; Crespo, M.; Guillamon, I.; Suderow, Hermann; Vieira, S.; Garcia Hernandez, M.; Budko, Serguei; Canfield, Paul

2012-03-30T23:59:59.000Z

162

Anomalous peak at low fields in the magnetization versus temperature curve in bulk ceramic high-temperature superconductors  

Science Journals Connector (OSTI)

When a bulk ceramic high-temperature superconductor is cooled in a small field and the magnetic moment of the sample is measured as the sample is warmed, an anomalous peak in the magnetic moment is observed. This peak can be as high as 50% of the low-temperature moment for fields less than 1 Oe, but it rapidly decreases as the magnetic field increases. We show that this anomaly is due to the interrelationship between flux trapping by intergranular weak links and the irreversible flux trapping properties of the superconducting grains as recently described by Hao and Clem.

J. P. Wang and W. C. H. Joiner

1994-07-01T23:59:59.000Z

163

Superconducting properties of a textured NbN film from N93b NMR relaxation and magnetization measurements  

Science Journals Connector (OSTI)

Primarily motivated by the similarities between the underdoped superconducting cuprates and the granular systems in regards of electric conductivity, phase fluctuations of the order parameter, and nuclear spin-lattice relaxation, a study has been carried out in a NbN(111) textured film at controlled granularity by means of superconducting quantum interference device magnetization and N93b NMR measurements. The Meissner diamagnetism in zero-field-cooling and field-cooling conditions and for different orientation of the magnetic field and the isothermal magnetization curves around the superconducting transition temperature Tc, are studied. N93b spectra and relaxation measurements have been performed for two values of the external magnetic field in parallel and perpendicular geometry, in the temperature range 4–300 K. In the superconducting phase the experimental findings for the textured film are similar to the one in bulk NbN. The nuclear spin-lattice relaxation process is the same as in bulk NbN in the temperature range 50–300 K, confirming a dominant contribution to the density of states at the Fermi energy arising from the Nb 4d band. At variance, on cooling from about 40 K down to Tc (H), the N93b relaxation rate in the film dramatically departs from the expected behavior for the Fermi gas and mimics the opening of a spin gap. The interpretation of the spin-gap opening in terms of depletion in the density of states at the Fermi energy can justify the anomalous temperature behavior of the N93b relaxation rate on approaching Tc (H) from above. The experimental findings suggest the occurrence of superconducting fluctuations (density-of-states term) in one-dimensional regime, coupled to a reduction in the time of flight of the electrons, both effects being related to the granularity. The data also suggest that the spin-gap phase in underdoped cuprates could be connected more to granularity, rather than to exotic mechanisms of magnetic origin.

A. Lascialfari; A. Rigamonti; E. Bernardi; M. Corti; A. Gauzzi; J. C. Villegier

2009-09-09T23:59:59.000Z

164

Magnetism in SQUIDs at Millikelvin Temperatures  

Science Journals Connector (OSTI)

We have characterized the temperature dependence of the flux threading dc SQUIDs cooled to millikelvin temperatures. The flux increases as 1/T as temperature is lowered; moreover, the flux change is proportional to the density of trapped vortices. The data are compatible with the thermal polarization of surface spins in the trapped fields of the vortices. In the absence of trapped flux, we observe evidence of spin-glass freezing at low temperature. These results suggest an explanation for the universal 1/f flux noise in SQUIDs and superconducting qubits.

S. Sendelbach; D. Hover; A. Kittel; M. Mück; John M. Martinis; R. McDermott

2008-06-05T23:59:59.000Z

165

Transition temperatures and vacancies in superconducting Rb{sub 3}C{sub 60}  

SciTech Connect (OSTI)

We have studied the role of alkali-metal vacancies in the structure and superconductivity in nominal Rb{sub 3}C{sub 60} through preparation of samples with different alkali-metal loadings and annealing temperatures, to search for the possible role of nonstoichiometry in superconductivity. We find sample-to-sample variations of {approx}1 K in the superconducting transition temperature, but this does not correlate with vacancy concentration. We conclude that a model of electronic structure of alkali-metal fullerenes based on proximity to a Mott-Hubbard transition at integer doping is not applicable.

Huq, Ashfia; Stephens, Peter W. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800 (United States)

2005-09-01T23:59:59.000Z

166

Electron Temperature Structures Associated With Magnetic Tearing  

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

flattening is characteristic of rapid parallel heat conduction along helical magnetic field lines. The spatial structure of the temperature fluctuations show that the location of...

167

Transition temperature and a spatial dependence of the superconducting gap for multilayer high-temperature superconductors  

Science Journals Connector (OSTI)

We derive the expressions for the transition temperature Tc, and the spatial dependence of the superconducting gap for a multilayer high-Tc superconductor composed of groups of tightly spaced planes separated by a larger distance. The results are compared with experiment and provide strong support for an interlayer hopping as the driving force of the large Tc enhancement in multilayered compounds. Our results are universal in the sense that they are valid for an arbitrary pairing potential Vkk? in the CuO2 planes, as well as for both Fermi- and non-Fermi-liquids.

Krzysztof Byczuk and Jozef Spa?ek

1996-01-01T23:59:59.000Z

168

Phonon spectrum of QCD vacuum in magnetic-field-induced superconducting phase  

E-Print Network [OSTI]

In the background of a sufficiently strong magnetic field the vacuum was suggested to become an ideal electric conductor (highly anisotropic superconductor) due to an interplay between the strong and electromagnetic forces. The superconducting ground state resembles an Abrikosov lattice state in an ordinary type-II superconductor: it is an inhomogeneous structure made of a (charged vector) quark-antiquark condensate pierced by vortices. In this paper the acoustic (phonon) vibrational modes of the vortex lattice are studied in the mean-field approach at zero temperature. Using an effective model based on a vector meson dominance, we show that in the infrared limit the longitudinal (transverse) acoustic vibrations of the vortex lattice possess a linear (quadratic) dispersion relation corresponding to type I (type II) Nambu-Goldstone modes.

Chernodub, M N; Verschelde, Henri

2014-01-01T23:59:59.000Z

169

Phonon spectrum of QCD vacuum in magnetic-field-induced superconducting phase  

E-Print Network [OSTI]

In the background of a sufficiently strong magnetic field the vacuum was suggested to become an ideal electric conductor (highly anisotropic superconductor) due to an interplay between the strong and electromagnetic forces. The superconducting ground state resembles an Abrikosov lattice state in an ordinary type--II superconductor: it is an inhomogeneous structure made of a (charged vector) quark-antiquark condensate pierced by vortices. In this paper the acoustic (phonon) vibrational modes of the vortex lattice are studied at zero temperature. Using an effective model based on a vector meson dominance, we show that in the infrared limit the longitudinal (transverse) acoustic vibrations of the vortex lattice possess a linear (quadratic) dispersion relation corresponding to type I (type II) Nambu--Goldstone modes.

M. N. Chernodub; Jos Van Doorsselaere; Henri Verschelde

2014-01-01T23:59:59.000Z

170

The Cost of Superconducting Magnets as a Function of Stored Energy and Design Magnetic Induction Times the Field Volume  

SciTech Connect (OSTI)

By various theorems one can relate the capital cost of superconducting magnets to the magnetic energy stored within that magnet. This is particularly true for magnet where the cost is dominated by the structure needed to carry the magnetic forces. One can also relate the cost of the magnet to the product of the magnetic induction and the field volume. The relationship used to estimate the cost the magnet is a function of the type of magnet it is. This paper updates the cost functions given in two papers that were published in the early 1990 s. The costs (escalated to 2007 dollars) of large numbers of LTS magnets are plotted against stored energy and magnetic field time field volume. Escalated costs for magnets built since the early 1990 s are added to the plots.

Green, Mike; Green, M.A.; Strauss, B.P.

2007-08-27T23:59:59.000Z

171

Magnet tests and status of the superconducting electron cyclotron resonance source SERSE  

SciTech Connect (OSTI)

At Laboratorio Nazionale del Sud a superconducting 14.5 GHz electron cyclotron resonance (ECR) source will be used as injector for the K-800 superconducting cyclotron. The original project of its magnetic system has been upgraded by taking into account the results of the high B mode operation of the 6.4 GHz SC-ECRIS at MSU-NSCL and now the mirror field may achieve 2.7 T, which is much higher than the confining field of any other ECR source. The magnet design will allow us to operate in a wide range of magnetic configurations making it easy to tune the source. The status of the project will be outlined and the preliminary results of the tests of the superconducting magnets will be described. A brief description of the tests to be carried out on the source during the first period of operation on the test bench in Grenoble follows. {copyright} {ital 1996 American Institute of Physics.}

Ciavola, G.; Gammino, S.; Cafici, M.; Castro, M.; Chines, F.; Marletta, S. [INFN-Laboratorio Nazionale del Sud, Via S. Sofia 44, 95123 Catania (Italy)] [INFN-Laboratorio Nazionale del Sud, Via S. Sofia 44, 95123 Catania (Italy); Alessandria, F. [INFN-LASA, Via F.lli Cervi 201, 20090 Segrate (Midway Islands) (Italy)] [INFN-LASA, Via F.lli Cervi 201, 20090 Segrate (Midway Islands) (Italy); Bourg, F.; Briand, P.; Melin, G.; Lagnier, R.; Seyfert, P. [CEA-Departement de Recherche Fondamentale sur la Matiere Condensee, Centre detudes Nucleaires de Grenoble, 38054 Grenoble Cedex 9 (France)] [CEA-Departement de Recherche Fondamentale sur la Matiere Condensee, Centre detudes Nucleaires de Grenoble, 38054 Grenoble Cedex 9 (France); Gaggero, G.; Losasso, M.; Penco, R. [ANSALDO-GIE, Via N. Lorenzi 8, 16152 Genova (Italy)] [ANSALDO-GIE, Via N. Lorenzi 8, 16152 Genova (Italy)

1996-03-01T23:59:59.000Z

172

SciTech Connect: Ultrasonic signatures at the superconducting...  

Office of Scientific and Technical Information (OSTI)

that extends from room temperature to the superconducting transition. Although polarized neutron scattering studies hint at magnetic order associated with the pseudogap, there is...

173

Interaction of magnetic field and magnetic history in high-temperature superconductors  

Science Journals Connector (OSTI)

Yttrium barium copper oxide (YBCO) coated conductors are now the most promising high-temperature superconducting tapes in terms of current capacity and price. One form of these conductors utilizes YBCO films on Ni–W metallic tapes and is being considered for a number of power engineering applications. In these applications the conductor will carry an ac current leading to energy losses which are the focus of significant technical and experimental efforts. Our measurements of the ac losses of YBCO/Ni–W conductors carrying ac currents in applied dc magnetic fields have revealed a complex interaction between the magnetic materials present the geometry of the conductor the ac and dc magnetic fields and the electromagnetic “history” of the sample. The investigation of this interaction is the main subject of this paper.

Francesco Grilli; Stephen P. Ashworth; Leonardo Civale

2007-01-01T23:59:59.000Z

174

Stability tests of the Westinghouse coil in the International Fusion Superconducting Magnet Test Facility  

SciTech Connect (OSTI)

The Westinghouse coil is one of three forced-flow coils in the six-coil toroidal array of the International Fusion Superconducting Magnet Test Facility at Oak Ridge National Laboratory. It is wound with an 18-kA, Nb/sub 3/Sn/Cu, cable-in-conduit superconductor structurally supported by aluminum plates and cooled by 4-K, 15-atm supercritical helium. The coil is instrumented to permit measurement of helium temperature, pressure, and flow rate; structure temperature and strain; field; and normal zone voltage. A resistive heater has been installed to simulate nuclear heating, and inductive heaters have been installed to facilitate stability testing. The coil has been tested both individually and in the six-coil array. The tests covered charging to full design current and field, measuring the current-sharing threshold temperature using the resistive heaters, and measuring the stability margin using the pulsed inductive heaters. At least one section of the conductor exhibits a very broad resistive transition (resistive transition index = 4). The broad transition, though causing the appearance of voltage at relatively low temperatures, does not compromise the stability margin of the coil, which was greater than 1.1 J/cm/sup 3/ of strands. In another, nonresistive location, the stability margin was between 1.7 and 1.9 J/cm/sup 3/ of strands. The coil is completely stable in operation at 100% design current in both the single- and six-coil modes.

Dresner, L.; Fehling, D.T.; Lubell, M.S.; Lue, J.W.; Luton, J.N.; McManamy, T.J.; Shen, S.S.; Wilson, C.T.

1987-09-01T23:59:59.000Z

175

The feasibility of low-mass conductors for toroidal superconducting magnets for SSC (Superconducting Super Collider) detectors  

SciTech Connect (OSTI)

An earlier study by Luton and Bonanos concluded that the design and fabrication of superconducting toroidal bending magnets would require a major effort but would be feasible. This study is an extension to examine the feasibility of low-mass conductors for such use. It included a literature search, consultations, with conductor manufacturers, and design calculations, but no experimental work. An unoptimized sample design that used a residual resistivity ratio for aluminum of 1360 and a current density of 3.5 kA/cm{sup 2} over the uninsulated conductor for a 4.5-T toroid with 1 GJ of stored energy obtained a hot-spot temperature of 120 K with a maximum dump voltage of 3.6 kV and 24% of the initial current inductively transferred into the shorted aluminum structure. The stability margin was 200 mJ/cm{sup 3} of cable space. Limiting the quench pressure to 360 atm to give conservative stresses in the sheath and assuming that the whole flow path quenched immediately resulted in helium taps that could be a kilometer apart if the flow friction factor were the same as that experienced in the Westinghouse (W) Large Coil Task (LCT) coil. This indicates that the 520-m conductor length of each of the 72 individual coil segments of a toroid would be a single flow path. If some practical uncertainties can be favorably resolved by producing and testing sample conductors, the use of a conductor with clad-aluminum stabilizer and extruded aluminum-alloy sheath should be feasible and economical. 9 refs., 3 figs.

Luton, J.N.

1990-01-01T23:59:59.000Z

176

Improving the design and analysis of superconducting magnets for particle accelerators  

SciTech Connect (OSTI)

High energy particle accelerators are now the primary means of discovering the basic building blocks of matter and understanding the forces between them. In order to minimize the cost of building these machines, superconducting magnets are used in essentially all present day high energy proton and heavy ion colliders. The cost of superconducting magnets is typically in the range of 20--30% of the total cost of building such machines. The circulating particle beam goes through these magnets a large number of times (over hundreds of millions). The luminosity performance and life time of the beam in these machines depends significantly on the field quality in these magnets. Therefore, even a small error in the magnetic field shape may create a large cumulative effect in the beam trajectory to throw the particles of the magnet aperture. The superconducting accelerator magnets must, therefore, be designed and constructed so that these errors are small. In this thesis the research and development work will be described 3which has resulted in significant improvements in the field quality of the superconducting magnets for the Relativistic Heavy Ion Collider (RHIC). The design and the field quality improvements in the prototype of the main collider dipole magnet for the Superconducting Super Collider (SSC) will also be presented. RHIC will accelerate and collide two counter rotating beams of heavy ions up to 100 GeV/u and protons up to 250 GeV. It is expected that RHIC will create a hot, dense quark-gluon plasma and the conditions which, according to the Big Bang theory, existed in the early universe.

Gupta, R.C. [Univ. of Rajasthan, Jaipur (India). Dept. of Physics]|[Brookhaven National Lab., Upton, NY (United States). Magnet Div.

1996-11-01T23:59:59.000Z

177

Magnetism and superconductivity driven by identical 4f states in a heavy-fermion metal  

SciTech Connect (OSTI)

The apparently inimical relationship between magnetism and superconductivity has come under increasing scrutiny in a wide range of material classes, where the free energy landscape conspires to bring them in close proximity to each other. Particularly enigmatic is the case when these phases microscopically interpenetrate, though the manner in which this can be accomplished remains to be fully comprehended. Here, we present combined measurements of elastic neutron scattering, magnetotransport, and heat capacity on a prototypical heavy fermion system, in which antiferromagnetism and superconductivity are observed. Monitoring the response of these states to the presence of the other, as well as to external thermal and magnetic perturbations, points to the possibility that they emerge from different parts of the Fermi surface. Therefore, a single 4f state could be both localized and itinerant, thus accounting for the coexistence of magnetism and superconductivity.

Thompson, Joe E [Los Alamos National Laboratory; Nair, S [MAX PLANCK INST.; Stockert, O [MAX PLANCK INST.; Witte, U [INST. FUR FESTKORPERPHYSIK; Nicklas, M [MAX PLANCK INST.; Schedler, R [HELMHOLTZ - ZENTRUM; Bianchi, A [UC, IRVINE; Fisk, Z [UC, IRVINE; Wirth, S [MAX PLANCK INST.; Steglich, K [HELMHOLTZ - ZENTRUM

2009-01-01T23:59:59.000Z

178

Spin Torques in Magnetic and Superconducting Tunnel Junctions  

E-Print Network [OSTI]

Josephson Junctions . . . . . . . . . . . . . . . . . . . . .Nonlinear Dynamics in a Magnetic Josephson Junction . . . .in a magnetic Josephson junction. ” Phys. Rev. B, 86:

Hoffman, Silas Eli

2012-01-01T23:59:59.000Z

179

Engineering Nanocolumnar Defect Configurations for Optimized Vortex Pinning in High Temperature Superconducting Nanocomposite Wires  

SciTech Connect (OSTI)

High temperature superconducting (HTS), coated conductor wires based on nanocomposite films containing self-assembled, insulating BaZrO3 (BZO) nanocolumnar defects have previously been reported to exhibit enhanced vortex pinning. Here, we report on microstructural design via control of BZO nanocolumns density in YBa2Cu3O7- (YBCO)+BZO nancomposite films to achieve the highest critical current density, Jc(H, ,T). X-ray diffraction and microstructural examination shows increasing number density of epitaxial BZO nanocolumns in the highly cube-textured YBCO matrix with increasing nominal BZO additions. Transport property measurement reveals that an increase in BZO content upto 4 vol% is required to sustain the highest pinning and Jc performance as the magnetic field increases. By growing thicker, single-layer nanocomposite films (~4 m) with controlled density of BZO columnar defects, the critical current (Ic) of ~1000 A/cm at 77 K, self-field and the minimum Ic of 455 A/cm at 65 K and 3 T for all magnetic field orientations were obtained. This is the highest Ic reported to date for films on metallic templates which are the basis for the 2nd generation, coated conductor-based HTS wires.

Wee, Sung Hun [ORNL; Zuev, Yuri L [ORNL; Cantoni, Claudia [ORNL; Goyal, Amit [ORNL; Ahuja, Raj [Waukesha Electric Systems Inc.; Abiade, J. [North Carolina A& T State University

2013-01-01T23:59:59.000Z

180

High Temperature, Permanent Magnet Biased Magnetic Bearings  

E-Print Network [OSTI]

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...

Gandhi, Varun R.

2010-07-14T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Magnetic order close to superconductivity in the iron-based layered LaO1-xFxFeAs systems  

SciTech Connect (OSTI)

Since the discovery of long-range antiferromagnetic (AF) order in the parent compounds of high-transition temperature (high-Tc) copper oxides,1,2 there have been tremendous efforts to understand the role of magnetism in the superconducting mechanism because superconductivity occurs when mobile electrons or holes are doped into the AF parent compounds. Much like high-Tc copper oxides, superconductivity in the newly discovered the rare-earth (R) ironbased oxide systems [ROFeAs] are derived from either electron3,4,5,6,7 or hole 8 doping of their nonsuperconducting parent compounds. The parent (nonsuperconducting)LaOFeAs material is metallic but shows anomalies near 150 K in both resistivity and dc magnetic susceptibility3. While optical conductivity and theoretical calculations suggest that LaOFeAs exhibits a spin-density-wave(SDW)instability that is suppressed by doping electrons to form superconductivity9, there has been no direct evidence of SDW order. Here we use neutron scattering to demonstrate that LaOFeAs undergoes an abrupt structural distortion below ~150 K, changing the symmetry from tetragonal (space group P4/nmm) to monoclinic (space group P112/n) at low temperatures, and then followed by the development of long range SDW-type AF order at ~137 K with a small moment but simple magnetic structure9. Doping the system with flourine suppresses both the magnetic order and structural distortion in favor of superconductivity. Therefore, much like high-Tc copper oxides, the superconducting regime in these Fe-based materials occurs in close proximity to a long-range ordered AF ground state.

de la Cruz, Clarina [University of Tennessee, Knoxville (UTK); Huang, Q. [National Institute of Standards and Technology (NIST); Lynn, J. W. [National Institute of Standards and Technology (NIST); Li, Jiying [ORNL; RatcliffIII, W [National Institute of Standards and Technology (NIST); Zarestky, Jerel L. [Ames Laboratory; Mook Jr, Herbert A [ORNL; Chen, G. F, [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics; Luo, J. L. [Chinese Academy of Sciences; Wang, N. L. [Chinese Academy of Sciences; Dai, Pengcheng [ORNL

2008-01-01T23:59:59.000Z

182

Magnetic order close to superconductivity in the iron-based layered LaO1-xFxFeAs systems  

SciTech Connect (OSTI)

Following the discovery of long-range antiferromagnetic order in the parent compounds of high-transition-temperature (high-T{sub c}) copper oxides, there have been efforts to understand the role of magnetism in the superconductivity that occurs when mobile 'electrons' or 'holes' are doped into the antiferromagnetic parent compounds. Superconductivity in the newly discovered rare-earth iron-based oxide systems ROFeAs (R, rare-earth metal) also arises from either electron or hole doping of their non-superconducting parent compounds. The parent material LaOFeAs is metallic but shows anomalies near 150 K in both resistivity and d.c. magnetic susceptibility. Although optical conductivity and theoretical calculations suggest that LaOFeAs exhibits a spin-density-wave (SDW) instability that is suppressed by doping with electrons to induce superconductivity, there has been no direct evidence of SDW order. Here we report neutron-scattering experiments that demonstrate that LaOFeAs undergoes an abrupt structural distortion below 155 K, changing the symmetry from tetragonal (space group P4/nmm) to monoclinic (space group P112/n) at low temperatures, and then, at 137 K, develops long-range SDW-type antiferromagnetic order with a small moment but simple magnetic structure. Doping the system with fluorine suppresses both the magnetic order and the structural distortion in favor of superconductivity. Therefore, like high-T{sub c} copper oxides, the superconducting regime in these iron-based materials occurs in close proximity to a long-range-ordered antiferromagnetic ground state.

Dela Cruz, Clarina R [ORNL; Huang, Q. [National Institute of Standards and Technology (NIST); Lynn, J. W. [National Institute of Standards and Technology (NIST); Li, Jiying [ORNL; Zarestky, Jerel L. [Ames Laboratory; Mook Jr, Herbert A [ORNL; Chen, G. F, [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics; Luo, J. L. [Chinese Academy of Sciences; Wang, N. L. [Chinese Academy of Sciences; Dai, Pengcheng [ORNL

2008-01-01T23:59:59.000Z

183

Development of high temperature superconductors for magnetic field applications  

SciTech Connect (OSTI)

The key requirement for magnetic field applications of high temperature superconductor (HTS) materials is to have conductors with high transport critical current density available for magnet builders. After 3 or 4 years of being without any such object, conductor makers have had recent success in producing simple conductor prototypes. These have permitted the construction of simple HTS magnets having self fields exceeding 1 tesla at 4K. Thus the scientific feasibility of making powerful HTS magnets has been demonstrated. Attention to the technological aspects of making HTS conductors for magnets with strong flux pinning and reduced superconducting granularity is now sensible and attractive. However, extrinsic defects such as filament sausaging, cracking, misaligned grains and other perturbation to long range current flow must be controlled at a low level if the benefit of intrinsic improvements to the critical current density is to be maintained in the conductor form. Due to the great complexity of the HTS materials, there is sometimes confusion as to whether a given sample has an intrinsically or extrinsically limited critical current density. Systematic microstructure variation experiments and resistive transition analysis are shown to be particularly helpful in this phase of conductor development.

Larbalestier, D.C.

1991-01-01T23:59:59.000Z

184

Development of high temperature superconductors for magnetic field applications  

SciTech Connect (OSTI)

The key requirement for magnetic field applications of high temperature superconductor (HTS) materials is to have conductors with high transport critical current density available for magnet builders. After 3 or 4 years of being without any such object, conductor makers have had recent success in producing simple conductor prototypes. These have permitted the construction of simple HTS magnets having self fields exceeding 1 tesla at 4K. Thus the scientific feasibility of making powerful HTS magnets has been demonstrated. Attention to the technological aspects of making HTS conductors for magnets with strong flux pinning and reduced superconducting granularity is now sensible and attractive. However, extrinsic defects such as filament sausaging, cracking, misaligned grains and other perturbation to long range current flow must be controlled at a low level if the benefit of intrinsic improvements to the critical current density is to be maintained in the conductor form. Due to the great complexity of the HTS materials, there is sometimes confusion as to whether a given sample has an intrinsically or extrinsically limited critical current density. Systematic microstructure variation experiments and resistive transition analysis are shown to be particularly helpful in this phase of conductor development.

Larbalestier, D.C.

1991-12-31T23:59:59.000Z

185

Mitigating Radiation Impact on Superconducting Magnets of the Higgs Factory Muon Collider  

E-Print Network [OSTI]

Recent discovery of a Higgs boson boosted interest in a low-energy medium-luminosity Muon Collider as a Higgs Factory (HF). A preliminary design of the HF storage ring (SR) is based on cos-theta Nb3Sn superconducting (SC) magnets with the coil inner diameter ranging from 50 cm in the interaction region to 16 cm in the arc. The coil cross-sections were chosen based on the operation margin, field quality and quench protection considerations to provide an adequate space for the beam pipe, helium channel and inner absorber (liner). With the 62.5-GeV muon energy and 2 x 10^12 muons per bunch, the electrons from muon decays deposit about 300 kW in the SC magnets, or unprecedented 1 kW/m dynamic heat load, which corresponds to a multi-MW room temperature equivalent. Based on the detailed MARS15 model built and intense simulations, a sophisticated protection system was designed for the entire SR to bring the peak power density in the SC coils safely below the quench limit and reduce the dynamic heat load to the cold ...

Mokhov, Nikolai; Kashikhin, Vadim V; Striganov, Sergei I; Tropin, Igor S; Zlobin, Alexander V

2015-01-01T23:59:59.000Z

186

High temperature, permanent magnet biased, homopolar magnetic bearing actuator  

E-Print Network [OSTI]

current resistance and improves the system efficiency because the magnetic field of the HTPM can suspend the major portion of the static load on bearing. A high temperature radial magnetic bearing was designed via an iterative search employing 3D finite...

Hossain, Mohammad Ahsan

2006-10-30T23:59:59.000Z

187

SciTech Connect: "high temperature superconductivity"  

Office of Scientific and Technical Information (OSTI)

high temperature superconductivity" Find high temperature superconductivity" Find How should I search Scitech Connect ... Basic or Advanced? Basic Search Advanced × Advanced Search Options Full Text: Bibliographic Data: Creator / Author: Name Name ORCID Title: Subject: Identifier Numbers: Research Org.: Sponsoring Org.: Site: All Alaska Power Administration, Juneau, Alaska (United States) Albany Research Center (ARC), Albany, OR (United States) Albuquerque Complex - NNSA Albuquerque Operations Office, Albuquerque, NM (United States) Amarillo National Resource Center for Plutonium, Amarillo, TX (United States) Ames Laboratory (AMES), Ames, IA (United States) Argonne National Laboratory (ANL), Argonne, IL (United States) Argonne National Laboratory-Advanced Photon Source (United States) Atlanta Regional Office,

188

Design studies of superconducting cos? magnets for a fast-pulsed synchrotron  

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

BNL-68235-AB BNL-68235-AB Abstract submitted to the 17 th International Conference on Magnet Technology (MT-17), Geneva, Switzerland, September 24-28, 2001 Design studies of superconducting cosθ θ θ θ magnets for a fast-pulsed synchrotron M. Wilson, G. Moritz, G. Ganetis, A. K. Ghosh, A. Jain, J. Muratore, R. Thomas, P. Wanderer, W. Hassenzahl Part of the GSI future project is an accelerator facility with two synchrotron rings in the same tunnel. The lower and upper rings have a rigidity of 100 and 200 Tm respectively. The upper ring will be equipped with superconducting cosθ magnets. The dipoles will be operated with fields up to 4 T and ramp rates up to 4 T/s and will be similar to the RHIC- dipoles. The challenge in building such magnets is the high ramp rate. Induced coupling and persistent

189

Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films and  

E-Print Network [OSTI]

Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films and Multifilament Ran Yang College of William & Mary, Department of Applied Science, 2008 Field: Surface and Interface Science, Degree: Ph.D. Advisor: Gunter Luepke, Associate Professor of Applied Science Abstract

Shaw, Leah B.

190

Stability tests of the Westinghouse coil in the International Fusion Superconducting Magnet Test Facility  

SciTech Connect (OSTI)

The Westinghouse coil is one of three forced-flow coils in the six-coil toroidal array of the International Fusion Superconducting Magnet Test Facility at Oak Ridge National Laboratory. It is wound with an 18-kA, Nb/sub 3/Sn/Cu, cable-in-conduit superconductor structurally supported by aluminum plates and cooled by 4-K, 15-atm supercritical helium. The coil has been tested both individually and in the six-coil array. The tests covered charging to full design current and field, measuring the current-sharing threshold temperature using the resistive heaters, and measuring the stability margin using the pulsed inductive heaters. At least one section of the conductor exhibits a very broad resistive transition. The broad transition, though causing the appearance of voltage at relatively low temperatures, does not compromise the stability margin of the coil, which was greater than 1.1J/cm/sup 3/ of strands. In another nonresistive location, the stability margin was between 1.7 and 1.9 J/cm/sup 3/ of strands. The coil is completely stable in operation at 100% design current in both the single- and six-coil modes.

Dresner, L.; Fehling, D.T.; Lubell, M.S.; Lue, J.W.; Luton, J.N.; McManamy, T.J.; Shen, S.S.; Wilson, C.T.

1988-03-01T23:59:59.000Z

191

Magnetic Excitations and Their Energy Change Available to Superconducting Condensation in Optimally Doped YBa2Cu3O6.95  

SciTech Connect (OSTI)

Understanding the magnetic excitations in high-temperature (high-T{sub c}) copper-oxide superconductors is important because they may mediate the electron pairing for superconductivity. By determining the wavevector (Q) and energy ({h_bar}{omega}) dependence of the magnetic excitations, it is possible to calculate the change in the exchange energy available to the superconducting condensation energy. For the high-T{sub c} superconductor YBa{sub 2}Cu{sub 3}O{sub 6+x}, the most prominent feature in the magnetic excitations is the resonance. Suggestions that the resonance contributes a major part of the superconducting condensation have not gained acceptance because the resonance is only a small portion of the total magnetic scattering. Here, we report an extensive mapping of magnetic excitations for YBa{sub 2}Cu{sub 3}O{sub 6.95} (T{sub c} {approx} 93 K). Absolute intensity measurements of the full spectra allow us to estimate the change in the magnetic exchange energy between the normal and superconducting states, which is about 15 times larger than the superconducting condensation energy - more than enough to provide the driving force for high-T{sub c} superconductivity in YBa{sub 2}Cu{sub 3}O{sub 6.95}.

Woo, H. [University of Tennessee, Knoxville (UTK); Dai, Pengcheng [ORNL; Hayden, S M. [University of Bristol, UK; Mook Jr, Herbert A [ORNL; Scalapino, D. J. [University of California, Santa Barbara; Perring, T. G. [ISIS Facility, Rutherford Appleton Laboratory; Dogan, F. [University of Washington, Seattle

2006-01-01T23:59:59.000Z

192

Weak-localization, near-magnetism, and triplet-pairing superconductivity in three dimensions  

SciTech Connect (OSTI)

In three-dimensional nearly magnetic Fermi liquids, disorder due to impurity scattering is shown to enhance the paramagnon strength and to weaken the triplet superconductivity pair-breaking parameter (through weak-localization quantum effects). As a result (a) ''heavy fermion'' superconductors are good candidates to exhibit triplet pairing and (b) normal liquid /sup 3/He can be considered as both nearly magnetic and nearly localized.

Beal-Monod, M.T.

1985-02-01T23:59:59.000Z

193

Superconductivity | ORNL Neutron Sciences  

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

Research Highlights Research Highlights Superconductivity Neutron diffraction reveals semiconducting phase and contributes to new understanding of iron-based superconductors Contact: Huibo Cao New VULCAN tests of Japanese cable for US ITER's central magnet system (2012) Contact: Ke An ARCS maps collaborative magnetic spin behavior in iron telluride (2011) Published Work: "Unconventional Temperature Enhanced Magnetism in Fe1:1Te" Contact: Igor Zaliznyak Doug Scalapino discusses "common thread" linking unconventional superconducting materials (2011) Contact: Douglas Scalapino Materials Engineering Research at SNS Helps International Collaboration on Fusion Energy Scientists and engineers at ORNL are working with the ITER Organization and the Japanese Atomic Energy Agency to resolve issues with a critical

194

Peculiarities of the current-voltage characteristics of a Josephson medium in a YBCO high-temperature superconductor  

Science Journals Connector (OSTI)

The influence of a weak magnetic field (H high-temperature superconductor (HTSC) near the superconducting transitio...

M. A. Vasyutin

2013-12-01T23:59:59.000Z

195

Comparative Assessment of Direct Drive High Temperature Superconducting Generators in Multi-Megawatt Class Wind Turbines  

SciTech Connect (OSTI)

This paper summarizes the work completed under the CRADA between NREL and American Superconductor (AMSC). The CRADA combined NREL and AMSC resources to benchmark high temperature superconducting direct drive (HTSDD) generator technology by integrating the technologies into a conceptual wind turbine design, and comparing the design to geared drive and permanent magnet direct drive (PMDD) wind turbine configurations. Analysis was accomplished by upgrading the NREL Wind Turbine Design Cost and Scaling Model to represent geared and PMDD turbines at machine ratings up to 10 MW and then comparing cost and mass figures of AMSC's HTSDD wind turbine designs to theoretical geared and PMDD turbine designs at 3.1, 6, and 10 MW sizes. Based on the cost and performance data supplied by AMSC, HTSDD technology has good potential to compete successfully as an alternative technology to PMDD and geared technology turbines in the multi megawatt classes. In addition, data suggests the economics of HTSDD turbines improve with increasing size, although several uncertainties remain for all machines in the 6 to 10 MW class.

Maples, B.; Hand, M.; Musial, W.

2010-10-01T23:59:59.000Z

196

A Magnetic Shielding Type Superconducting Fault-Current Limiter  

Science Journals Connector (OSTI)

In a Magnetic Shielding type Fault-Current Limiter (MSFCL), the characteristics of the magnetic ... ) is an important factor in limiting the current flow. In this study, to improve the efficiency of the fault current

N. Miyauchi; H. Nakane; S. Haseyama; S. Yoshizawa

1999-01-01T23:59:59.000Z

197

Phase-Boundary of several Multicube Superconducting Circuits in a Magnetic-Field of Arbitrary Magnitude and Direction  

E-Print Network [OSTI]

A previous study [C.-R. Hu and C.-H. Huang, Phys. Rev. B 43, 7718 (1991)] of the phase boundary T(c)(H) of a single-cube superconducting circuit in an external magnetic field H of arbitrary magnitude and direction is extended here to superconducting...

YI, YM; Hu, Chia-Ren.

1992-01-01T23:59:59.000Z

198

Full-power test of a string of magnets comprising a half-cell of the Superconducting Super Collider  

SciTech Connect (OSTI)

In this paper we describe the full-powered operation of a string of industrially-fabricated magnets comprising a half-cell of the Superconducting Super Collider (SSC). The completion of these tests marks the first successful operation of a major SSC subsystem. The five 15-m long dipole magnets in the string had an aperture of 50 mm and the single 5-m long quadrupole aperture was 40 mm. Power and cryogenic connections were made to the string through spool pieces that are prototypes for SSC operations. The string was cooled to cryogenic temperatures in early July, 1992, and power tests were performed at progressively higher currents up to the nominal SSC operating point above 6500 amperes achieved in mid-August. In this paper we report on the electrical and cryogenic performance of the string components and the quench protection system during these initial tests.

Burgett, W.; Christianson, M.; Coombes, R. [and others

1992-10-01T23:59:59.000Z

199

Superconductivity and fluctuating magnetism in quasi-two-dimensional {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br probed with implanted muons.  

SciTech Connect (OSTI)

A muon-spin relaxation ({mu}{sup +}SR) investigation is presented for the molecular superconductor {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br. Evidence is found for low-temperature phase separation throughout the bulk of the material, with only a fraction of the sample showing a superconducting signal, even for slow cooling. Rapid cooling reduces the superconducting fraction still further. For the superconducting phase, the in-plane penetration depth is measured to be {lambda}{parallel} = 0.47(1) {micro}m, and evidence is seen for a vortex decoupling transition in applied fields above 40 mT. The magnetic fluctuations in the normal state produce a precipitous drop in relaxation rate above 100 K, and we discuss the possible causes for the unusual relaxation that we observe for T > T{sub c}.

Lancaster, T.; Blundel, S. J.; Pratt, F. L.; Schlueter, J. A.; Materials Science Division; Rutherford Appleton Lab.; Oxford Univ.

2011-01-19T23:59:59.000Z

200

IMPROVING THE DESIGN AND ANALYSIS OF SUPERCONDUCTING MAGNETS FOR PARTICLE ACCELERATORS  

SciTech Connect (OSTI)

The field quality in superconducting magnets has been improved to a level that it does not appear to be a limiting factor on the performance of RHIC. The many methods developed, improved and adopted during the course of this work have contributed significantly to that performance. One can not only design and construct magnets with better field quality than in one made before but can also improve on that quality after construction. The relative field error ({Delta}B/B) can now be made as low as a few parts in 10{sup {minus}5} at 2/3 of the coil radius. This is about an order of magnitude better than what is generally expected for superconducting magnets. This extra high field quality is crucial to the luminosity performance of RHIC. The research work described here covers a number of areas which all must be addressed to build the production magnets with a high field quality. The work has been limited to the magnetic design of the cross section which in most cases essentially determines the field quality performance of the whole magnet since these magnets are generally long. Though the conclusions to be presented in this chapter have been discussed at the end of each chapter, a summary of them might be useful to present a complete picture. The lessons learned from these experiences may be useful in the design of new magnets. The possibilities of future improvements will also be presented.

GUPTA,R.C.

1996-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

30-MJ superconducting magnetic energy storage for electric-transmission stabilization  

SciTech Connect (OSTI)

The Bonneville Power Administration operates the electric power transmission system that connects the Pacific Northwest and southern California. The HVAC interties develop 0.35 Hz oscillations when the lines are heavily loaded. A 30 MJ (8.4 kWh) Superconducting Magnetic Energy Storage (SMES) unit with a 10 MW converter can provide system damping for the oscillation. The unit is scheduled for installation in 1982 and operation in 1982-83. Status of the project is described. The conductor has been fully tested electrically and mechanically and the 5 kA superconducting cable has been produced. The 30 MJ superconducting coil is essentially complete. All major components of the electrical and cryogenic systems except the nonconducting dewar have been completed. The refrigerator and converter are undergoing tests. The system is to be located at the BPA Tacoma Substation and operated by microwave link from Portland, OR.

Turner, R.D.; Rogers, J.D.

1981-01-01T23:59:59.000Z

202

Cryogenic Beam Loss Monitors for the Superconducting Magnets of the LHC  

E-Print Network [OSTI]

The Beam Loss Monitor detectors close to the interaction points of the Large Hadron Collider are currently located outside the cryostat, far from the superconducting coils of the magnets. In addition to their sensitivity to lost beam particles, they also detect particles coming from the experimental collisions, which do not contribute significantly to the heat deposition in the superconducting coils. In the future, with beams of higher energy and brightness resulting in higher luminosity, distinguishing between these interaction products and dangerous quench-provoking beam losses from the primary proton beams will be challenging. The system can be optimised by locating beam loss monitors as close as possible to the superconducting coils, inside the cold mass in a superfluid helium environment, at 1.9 K. The dose then measured by such Cryogenic Beam Loss Monitors would more precisely correspond to the real dose deposited in the coil. The candidates under investigation for such detectors are based on p+-n-n+ si...

Bartosik, MR; Sapinski, M; Kurfuerst, C; Griesmayer, E; Eremin, V; Verbitskaya, E

2014-01-01T23:59:59.000Z

203

National High Magnetic Field Laboratory - Magnets and Materials...  

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

which joined the Magnet Lab and Florida State University in 2006. The ASC advances the science and technology of superconductivity by investigating low temperature and high...

204

Magnetization of in situ multifilamentary superconducting Nb/sub 3/Sn-Cu composites  

SciTech Connect (OSTI)

Magnetic properties are reported for in situ superconducting Nb/sub 3/Sn composites that have exhibited attractive electrical properties and superior mechanical characteristics. Magnetization measurements were conducted up to 4 T at 4.2 K on a variety of samples of different sizes and twist pitches, and the results are presented in absolute M-H curves and losses per cycle. It is observed that the magnetization of such composites is generally proportional to the size of the wire (approx. 0.25 to 0.51 mm) rather than the fiber size (approx. 10/sup -7/ m), which indicates a strong coupling effect among Nb/sub 3/Sn fibers.

Shen, S.S.; Verhoeven, J.D.

1980-01-01T23:59:59.000Z

205

Free energy in the coexistence region of superconductivity and magnetic order  

Science Journals Connector (OSTI)

The free energy of superconductivity and magnetic order is computed with consideration of exchange and electromagnetic effects. We use the Grassman algebra in order to define the path integral over the fermions. Making use of functional derivatives, we compute the effective action in terms of the magnetic and superconductor order parameters and we find a sinusoidal magnetic order associated to a Lifshitz term with quasi-long-range order. The stability of the coexistence region is similar to the nonlinear ? model in a lower dimension.

D. Schmeltzer

1985-12-01T23:59:59.000Z

206

Design and Operation of the 30 MJ Superconducting Magnetic Storage System on the Bonneville Power Administration Bus  

Science Journals Connector (OSTI)

A superconducting magnetic energy storage (SMES) unit is suitable for power system stablization because it can provide positive ... was installed at the Tacoma Substation of the Bonneville Power Administration as...

R. I. Schermer; M. H. Barron; H. J. Boenig…

1984-01-01T23:59:59.000Z

207

High Temperature Superconducting Fault Current Limiter for Utility Applications  

Science Journals Connector (OSTI)

One of the most near term High Temperature Superconductor (HTS) applications is the Fault Current Limiter (FCL). It is a device that...

E. M. W. Leung; G. W. Albert; M. Dew…

1997-01-01T23:59:59.000Z

208

TPX superconducting Tokamak magnet system: 1995 design and status overview  

SciTech Connect (OSTI)

The TPX magnet preliminary design effort is summarized. Key results and accomplishments during preliminary design and supporting R and D are discussed, including conductor development, quench detection, TF and PF magnet design, conductor bending and forming, reaction heat treating, helium stubs, and winding pack insulation.

Deis, G.; Bulmer, R.; Carpenter, R. [and others

1995-09-29T23:59:59.000Z

209

Effect of superfluid helium at the inner coil face on cooling and stability in superconducting accelerator magnets  

Science Journals Connector (OSTI)

For the upcoming luminosity upgrade of CERN's Large Hadron Collider a main issue is to increase the effective heat removal from the superconducting cables in the final focusing quadrupole magnets. The focus here is on the effect of superfluid helium in the thin annular space between the windings and the beam pipe which is studied using finite element modeling. Below the lambda temperature the effect of helium is described by an effective thermal conductivity. The temperature distribution is strongly dependent on the heat flux and therefore on the dimensions of the cooling channels and the spatial distribution of the heat source. Especially the influence of the so-called ground-insulation flaps partly blocking helium flow in the annulus is of interest. For a high energy deposition the flaps are a limiting factor. A solution is to implement a corrugated edged flap such that openings exist while sufficient electrical insulation is maintained.

2012-01-01T23:59:59.000Z

210

A broadband microwave Corbino spectrometer at $^3$He temperatures and high magnetic fields  

E-Print Network [OSTI]

We present the technical details of a broadband microwave spectrometer for measuring the complex conductance of thin films covering the range from 50 MHz up to 16 GHz in the temperature range 300 mK to 6 K and at applied magnetic fields up to 8 Tesla. We measure the complex reflection from a sample terminating a coaxial transmission line and calibrate the signals with three standards with known reflection coefficients. Thermal isolation of the heat load from the inner conductor is accomplished by including a section of NbTi superconducting cable (transition temperature around 8 $-$ 9 K) and hermetic seal glass bead adapters. This enables us to stabilize the base temperature of the sample stage at 300 mK. However, the inclusion of this superconducting cable complicates the calibration procedure. We document the effects of the superconducting cable on our calibration procedure and the effects of applied magnetic fields and how we control the temperature with great repeatability for each measurement. We have suc...

Liu, Wei; Armitage, N P

2014-01-01T23:59:59.000Z

211

Magnetism at the interface between ferromagnetic and superconducting oxides  

E-Print Network [OSTI]

-rays and by off-specular neutron reflectometry. The resulting data yield microscopic insight into the interplay methods, X-ray magnetic circular dichroism (XMCD) and neutron reflectometry, yields a detailed microscopic

Loss, Daniel

212

Magnetic field measurement of superconducting dipolemagnets with harmonic coil and Hall probe  

SciTech Connect (OSTI)

Magnetic field measurements and field analyses of 1-m long superconducting dipole magnets fabricated at the National Laboratory for High Energy Physics (KEK) have been carried out using a harmonic coil with the bucking scheme. Conditions of the data acquisition are optimized to achieve the accurate and efficient measurements. Not only in the steady state of the magnet excitation by constant currents, but also on the way the excite current increases until the magnet quenches the field measurements have been tried, and the results are discussed in this paper on the possibility of the {open_quotes}on-the-fly{close_quotes} measurement using a harmonic coil. Some results on the so-called remnant field of the magnets measured with a Hall probe are also described.

Nakai, Hirotaka; Kabe, Atsushi; Terashima, Akio [National Lab. for High Energy Physics, Tsukuba-shi, Ibaraki-ken (Japan)] [and others

1996-12-31T23:59:59.000Z

213

Plant and operational features of the BPA 30 MJ superconducting magnetic energy storage system  

SciTech Connect (OSTI)

A 30 MJ superconducting magnetic energy storage (SMES) system was designed and developed for application in the Western US Power System to damp power oscillations that limit high voltage ac transmission. The system is in place at the Bonneville Power Administration (BPA) Tacoma Substation and has been in an experimental use for over a year. Extended operations of the unit have been undertaken with success. The physical, electrical, and operational features of the SMES system are given.

Rogers, J.D.; Hauer, J.F.

1984-01-01T23:59:59.000Z

214

Evidence of a Precursor Superconducting Phase at Temperatures as High as 180 K in RBa2Cu3O7-????(R=Y,Gd,Eu) Superconducting Crystals from Infrared Spectroscopy  

Science Journals Connector (OSTI)

We show that a multilayer analysis of the infrared c-axis response of RBa2Cu3O7-????(R=Y,Gd,Eu) provides important new information about the anomalous normal-state properties of underdoped cuprate high temperature superconductors. In addition to competing correlations which give rise to a pseudogap that depletes the low-energy electronic states below T*?Tc, it enables us to identify the onset of a precursor superconducting state below Tons>Tc. We map out the doping phase diagram of Tons which reaches a maximum of 180 K at strong underdoping and present magnetic field dependent data which confirm our conclusions.

A. Dubroka, M. Rössle, K. W. Kim, V. K. Malik, D. Munzar, D. N. Basov, A. A. Schafgans, S. J. Moon, C. T. Lin, D. Haug, V. Hinkov, B. Keimer, Th. Wolf, J. G. Storey, J. L. Tallon, and C. Bernhard

2011-01-27T23:59:59.000Z

215

Magnetic flux dynamics in a hexagonal network of superconducting islands  

E-Print Network [OSTI]

critical states, of inter- and intra-granular screening currents. The rate of flux penetration-based tapes. The magneto-optical observation showed a flux penetration/reversal process consisting of two Bean penetration into the grains. The grain magnetization was non- uniform and asymmetrical. Although grains stood

Johansen, Tom Henning

216

Muon spin relaxation studies of incommensurate magnetism and superconductivity in stage-4 La2CuO4.11 and La1.88Sr0.12CuO4  

E-Print Network [OSTI]

Muon spin relaxation studies of incommensurate magnetism and superconductivity in stage-4 La2CuO4-0011, Japan Received 1 February 2002; published 16 July 2002 We report muon spin relaxation ( SR) measurements, zero-field SR measurements show muon spin precession below the Ne´el temperature TN with frequency 3

217

COMMERCIALIZATION DEMONSTRATION OF MID-SIZED SUPERCONDUCTING MAGNETIC ENERGY STORAGE TECHNOLOGY FOR ELECTRIC UTILITYAPPLICATIONS  

SciTech Connect (OSTI)

As an outgrowth of the Technology Reinvestment Program of the 1990’s, an Agreement was formed between BWXT and the DOE to promote the commercialization of Superconducting Magnetic Energy Storage (SMES) technology. Business and marketing studies showed that the performance of electric transmission lines could be improved with this SMES technology by stabilizing the line thereby allowing the reserved stability margin to be used. One main benefit sought was to double the capacity and the amount of energy flow on an existing transmission line by enabling the use of the reserved stability margin, thereby doubling revenue. Also, electrical disturbances, power swings, oscillations, cascading disturbances and brown/black-outs could be mitigated and rendered innocuous; thereby improving power quality and reliability. Additionally, construction of new transmission lines needed for increased capacity could be delayed or perhaps avoided (with significant savings) by enabling the use of the reserved stability margin of the existing lines. Two crucial technical aspects were required; first, a large, powerful, dynamic, economic and reliable superconducting magnet, capable of oscillating power flow was needed; and second, an electrical power interface and control to a transmission line for testing, demonstrating and verifying the benefits and features of the SMES system was needed. A project was formed with the goals of commercializing the technology by demonstrating SMES technology for utility applications and to establish a domestic capability for manufacturing large superconducting magnets for both commercial and defense applications. The magnet had very low AC losses to support the dynamic and oscillating nature of the stabilizing power flow. Moreover, to economically interface to the transmission line, the magnet had the largest operating voltage ever made. The manufacturing of that design was achieved by establishing a factory with newly designed and acquired equipment, tooling, methods and skilled personnel. The final magnet system measured 14 feet in diameter, 10 feet in height, and weighed about 35 tons. The superconducting magnet and design technology was successfully implemented and demonstrated. The project was not successfully concluded however; as the critical planned final demonstration was not achieved. The utilities could not understand or clarify their future business needs and the regulatory requirements, because of the deregulation policies and practices of the country. Much uncertainty existed which prevented utilities from defining business plans, including asset allocation and cost recovery. Despite the technical successes and achievements, the commercial development could not be implemented and achieved. Thus, the demonstration of this enhancement to the utility’s transmission system and to the reliability of the nation’s electrical grid was not achieved. The factory was ultimately discontinued and the technology, equipment and product were placed in storage.

CHARLES M. WEBER

2008-06-24T23:59:59.000Z

218

Magnetization losses in superconducting YBCO conductor-on-round-core (CORC) cables  

Science Journals Connector (OSTI)

Described are the results of magnetization loss measurements made at 77 K on several YBCO conductor-on-round-core (CORC) cables in ac magnetic fields of up to 80 mT in amplitude and frequencies of 50 to 200 Hz, applied perpendicular to the cable axis. The cables contained up to 40 tapes that were wound in as many as 13 layers. Measurements on the cables with different configurations were made as functions of applied ac field amplitude and frequency to determine the effects of their layout on ac loss. In large scale devices such as e.g. Superconducting Magnetic Energy Storage (SMES) magnets, the observed ac losses represent less than 0.1% of their stored energy.

M Majoros; M D Sumption; E W Collings; D C van der Laan

2014-01-01T23:59:59.000Z

219

Relation between cuprate superconductivity and magnetism: A Raman study of (CaLa)1(BaLa)2Cu3Oy  

Science Journals Connector (OSTI)

We present an investigation of charge-compensated antiferromagnetic (CaxLa1?x)(Ba1.75?xLa0.25+x)Cu3Oy single crystals using Raman scattering as well as muon spin rotation. In this system the parameter x controls the Cu-O-Cu superexchange interaction via bond distances and buckling angles. The oxygen content y controls the charge doping. In the absence of doping the two-magnon peak position is directly proportional to the superexchange strength J. We find that both x and y affect the peak position considerably. The Néel temperature determined from muon spin rotation on the same samples independently confirms the strong dependence of the magnetic interaction on x and y. We find a considerable increase in the maximum superconducting transition temperature Tcmax with J. This is strong evidence of the importance of orbital overlap to superconductivity in this family of cuprates.

Dirk Wulferding; Meni Shay; Gil Drachuck; Rinat Ofer; Galina Bazalitsky; Zaher Salman; Peter Lemmens; Amit Keren

2014-09-17T23:59:59.000Z

220

Temperature relaxation in a magnetized plasma  

SciTech Connect (OSTI)

A magnetic field greatly affects the relaxation phenomena in a plasma when the particles’ thermal gyro-radii are smaller than the Debye length. Its influence on the temperature relaxation (TR) is investigated through consideration of binary collisions between charged particles in the presence of a uniform magnetic field within a perturbation theory. The relaxation times are calculated. It is shown that the electron-electron (e-e) and ion-ion (i-i) TR rates first increase and then decrease as the magnetic field grows, and the doubly logarithmic term contained in the electron-ion (e-i) TR rate results from the exchange between the electron parallel and the ion perpendicular kinetic energies.

Dong, Chao; Ren, Haijun; Cai, Huishan [Department of Modern Physics, University of Science and Technology of China, Anhui Hefei 230026 (China)] [Department of Modern Physics, University of Science and Technology of China, Anhui Hefei 230026 (China); Li, Ding [Department of Modern Physics, University of Science and Technology of China, Anhui Hefei 230026 (China) [Department of Modern Physics, University of Science and Technology of China, Anhui Hefei 230026 (China); Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2013-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

High-Tc superconductivity originated from strong spin-charge correlation: indication from linear temperature dependence of resistivity  

E-Print Network [OSTI]

Both the highest- and the linear temperature dependence of the resistivity in wide temperature range appear at the optimally doped regions of Cu-based superconductors1,2,3,4,5, and the highest- of Fe-based superconductors6,7 are also associated with the linear temperature dependence of the resistivity in normal states near superconducting states. This means that the high temperature superconductivity and the linear temperature dependence of the resistivity should be dominated by the same mechanism. This letter on theoretic calculation clearly shows that strong spin-charge correlation dominated resistivity behaves the linear temperature dependence, thus high-temperature superconductivity should be induced by strong spin-charge correlation.

Tian De Cao

2007-06-01T23:59:59.000Z

222

Magnetism in Iron at High Temperatures  

Science Journals Connector (OSTI)

Magnetism in iron at high temperature is investigated by calculating the total electronic band-structure energy for four types of spin arrangements. A slow smooth spatial variation of spin direction costs relatively little energy and the atomic moment m is reduced only ? 10%. More rapid variations have considerably higher energy, which may explain the high degree of short-range order and small ?m observed at T?TC. Other aspects are also discussed.

M. V. You; V. Heine; A. J. Holden; P. J. Lin-Chung

1980-05-12T23:59:59.000Z

223

Beta Beams for Neutrino Production Heat Deposition from Decaying Ions in Superconducting Magnets  

E-Print Network [OSTI]

This report describes studies of energy deposition in superconducting magnets from secondary ions in the "beta beam" decay ring as described in the base-line scenario of the EURISOL Beta Beam Design Study. The lattice structure proposed in the Design Study has absorber elements inserted between the superconducting magnets to protect the magnet coils. We describe an efficient and small model made to carry out the study. The specially developed options in the beam code "ACCSIM" to track largely off-momentum particles has permitted to extract the necessary information to interface the transport and interaction code "FLUKA" with the aim to calculate the heat deposition in the magnets and the absorbers. The two beta emitters 18Ne10+ and 6He2+ used for neutrino and anti-neutrino production and their daughter ions have been tracked. The absorber system proposed in the Design Study is efficient to intercept the ions decayed in the arc straight sections as foreseen, however, the continuous decay in the dipoles induce ...

Wildner, Elena; Cerutti, F

2008-01-01T23:59:59.000Z

224

Beta Beams for neutrino production: Heat deposition from decaying ions in superconducting magnets  

E-Print Network [OSTI]

This note describes studies of energy deposition in superconducting magnets from secondary ions in the “beta beam” decay ring as described in the base-line scenario of the EURISOL Beta Beam Design Study. The lattice structure proposed in the Design Study has absorber elements inserted between the superconducting magnets to protect the magnet coils. We describe an efficient and small model made to carry out the study. The specially developed options in the beam code “ACCSIM” to track largely off-momentum particles has permitted to extract the necessary information to interface the transport and interaction code “FLUKA” with the aim to calculate the heat deposition in the magnets and the absorbers. The two beta emitters 18Ne10+ and 6He2+ used for neutrino and anti-neutrino production and their daughter ions have been tracked. The absorber system proposed in the Design Study is efficient to intercept the ions decayed in the arc straight sections as foreseen, however, the continuous decay in the dipol...

Wildner, Elena; Cerutti, Francesco

225

Superconducting Magnetic Energy Storage (SMES) Program. Progress report, January 1-December 31, 1983  

SciTech Connect (OSTI)

The 30 MJ superconducting magnetic energy storage (SMES) unit, devised to damp unstable power oscillations in the Western US Power System, was placed into operation in the Bonneville power Administration (BPA) Tacoma Substation. Cooldown of the 30 MJ superconducting coil was completed, and helium was liquefied for the coil environment in the containing nonconducting fiberglass reinforced plastic dewar. The converter was connected to the coil and the first operation of the SMES system occurred in March 1983. BPA developed a demand signal algorithm for computer control of the power subsystem. The SMES unit was operated for system response and has now operated successfully for extended periods. BPA has installed a number of faults signal alarms that are transmitted by microwave link to their main dispatch-control center at Dittmer to monitor the SMES system when in unmanned operation.

Rogers, J.D. (comp.)

1984-05-01T23:59:59.000Z

226

Low temperature specific heat of superconducting ternary intermetallics  

Science Journals Connector (OSTI)

A systematic investigation on the thermodynamic properties of La-based ternary intermetallic superconductors crystallizing in a U3Ni4Si4-type structure is presented. The U3Ni4Si4-type structure consists of a characteristic intergrowth of periodic BaAl4 (ThCr2Si2)- and AlB2-type segments. Pristine low temperature specific heat data for recently discovered members La3Ni4Si4 and La3Ni4Ge4 with Tcs of 1.0 and 0.7 K, respectively, are presented as well as La3Pd4Ge4 with the highest Tc of 2.5 K in the U3Ni4Si4-type group. Owing to the higher Tcs of U3Ni4Si4-type superconductors than the related ThCr2Si2-type compounds, comparisons are drawn in our investigations of the ternary intermetallics of LaPd2Ge2, LaNi2Si2, and LaNi2Ge2 having a ThCr2Si2-type structure. Our investigations of the thermodynamic properties show that La3Ni4Si4 and La3Ni4Ge4 have higher values of ?n, N(EF), and ?D than La3Pd4Ge4. The same trend was found in ThCr2Si2-type compounds of LaPd2Ge2, LaNi2Si2, and LaNi2Ge2. It turns out that the difference in Tc between La3Pd4Ge4, La3Ni4Si4, and La3Ni4Ge4, as well as the relatively higher Tc of the U3Ni4Si4-type superconductors than of the related ThCr2Si2-type compounds, are largely due to the strength of electron–phonon coupling.

S Kasahara; H Fujii; H Takeya; T Mochiku; A D Thakur; K Hirata

2008-01-01T23:59:59.000Z

227

A compact bellows-driven diamond anvil cell for high-pressure, low-temperature magnetic measurements  

SciTech Connect (OSTI)

We present the design of an efficient bellows-controlled diamond anvil cell that is optimized for use inside the bores of high-field superconducting magnets in helium-3 cryostats, dilution refrigerators, and commercial physical property measurement systems. Design of this non-magnetic pressure cell focuses on in situ pressure tuning and measurement by means of a helium-filled bellows actuator and fiber-coupled ruby fluorescence spectroscopy, respectively. We demonstrate the utility of this pressure cell with ac susceptibility measurements of superconducting, ferromagnetic, and antiferromagnetic phase transitions to pressures exceeding 8 GPa. This cell provides an opportunity to probe charge and magnetic order continuously and with high resolution in the three-dimensional Magnetic Field–Pressure–Temperature parameter space.

Feng, Yejun [The Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [The Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States); Silevitch, D. M.; Rosenbaum, T. F. [The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States)] [The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States)

2014-03-15T23:59:59.000Z

228

Interpretation of the harmonic response of superconducting films to inhomogeneous ac magnetic fields  

Science Journals Connector (OSTI)

We present a quantitative analysis of the response of a thin superconducting film to an applied nonuniform ac magnetic field. The analysis is directly applicable to the single-coil inductive measurement technique where a small coil driven by an ac current produces a nonuniform field, with JC determined by the appearance of a third-harmonic component of the voltage generated across the coil. We derive a simple model to explain the response of the film to the applied magnetic field in the absence of weak links. This model is used to predict the third-harmonic voltage generated across the coil. The derivation of the model explains why superconducting films having thicknesses even less than the penetration depth screen out the nonuniform ac magnetic fields generated by the coil. A simplified version of the model yields analytic expressions that describe the magnitude and phase of the third-harmonic component at high drive currents while the full model yields excellent agreement with experimental measurements for our highest quality epitaxial films. In other films, the presence of weak links leads to a characteristic signature in the harmonic response at low drive currents. We have also found that ion irradiation can reduce the critical current densities by significant amounts without introducing weak links into the film.

G. D. Poulin; J. S. Preston; T. Strach

1993-07-01T23:59:59.000Z

229

International Large Coil Task: testing of the largest superconducting toroidal magnet system  

SciTech Connect (OSTI)

The Large Coil Task is an international collaboration of the United States, EURATOM, Japan, and Switzerland to develop large superconducting magnets for fusion reactors. The first tests of all six coils were begun in February 1986 when the 420-ton test array was cooled to 4.2 K. Each of the heavily instrumented coils was tested alone to full design current. Heat perturbations (recovery, simulating nuclear heating, or current-sharing tempeature measurements) to investigate design limits were carried out. Two of the coils have been tested in the full array to full current, producing an 8.1-T maximum field. All coils have performed very well without training or quenching.

Lubell, M.S.; Fietz, W.A.; Haubenreich, P.N.; Lue, J.W.; Luton, J.N.; Shen, S.S.; Okuno, K.; Ulbricht, A.R.; Zichy, J.A.

1986-01-01T23:59:59.000Z

230

Electronic structure, magnetism, and superconductivity of MgCxNi3  

Science Journals Connector (OSTI)

The electronic structure of the newly discovered superconducting perovskite MgCNi3 is calculated using the LMTO method. The states near the Fermi energy are found to be dominated by Ni-d. The Stoner factor is low while the electron-phonon coupling constant is estimated to be about 0.5, which suggests that the material is a conventional type of superconductor where Tc is not affected by magnetic interactions. However, the proximity of the Fermi energy to a large peak in the density of states in conjunction with the reported nonstoichiometry of the compound has consequences for the stability of the results.

S. B. Dugdale and T. Jarlborg

2001-08-22T23:59:59.000Z

231

A study of the status and future of superconducting magnetic energy storage in power  

Science Journals Connector (OSTI)

Superconducting magnetic energy storage (SMES) systems offering flexible, reliable, and fast acting power compensation are applicable to power systems to improve power system stabilities and to advance power qualities. The authors have summarized researches on SMES applications to power systems. Furthermore, various SMES applications to power systems have been described briefly and some crucial schematic diagrams and equations are given. In addition, this study presents valuable suggestions for future studies of SMES applications to power systems. Hence, this paper is helpful for co-researchers who want to know about the status of SMES applications to power systems.

X D Xue; K W E Cheng; D Sutanto

2006-01-01T23:59:59.000Z

232

The US market for high-temperature superconducting wire in transmission cable applications  

SciTech Connect (OSTI)

Telephone interviews were conducted with 23 utility engineers concerning the future prospects for high-temperature superconducting (HTS) transmission cables. All have direct responsibility for transmission in their utility, most of them in a management capacity. The engineers represented their utilities as members of the Electric Power Research Institute`s Underground Transmission Task Force (which has since been disbanded). In that capacity, they followed the superconducting transmission cable program and are aware of the cryogenic implications. Nineteen of the 23 engineers stated the market for underground transmission would grow during the next decade. Twelve of those specified an annual growth rate; the average of these responses was 5.6%. Adjusting that figure downward to incorporate the remaining responses, this study assumes an average growth rate of 3.4%. Factors driving the growth rate include the difficulty in securing rights-of-way for overhead lines, new construction techniques that reduce the costs of underground transmission, deregulation, and the possibility that public utility commissions will allow utilities to include overhead costs in their rate base. Utilities have few plans to replace existing cable as preventive maintenance, even though much of the existing cable has exceeded its 40-year lifetime. Ten of the respondents said the availability of a superconducting cable with the same life-cycle costs as a conventional cable and twice the ampacity would induce them to consider retrofits. The respondents said a cable with those characteristics would capture 73% of their cable retrofits.

Forbes, D.

1996-04-01T23:59:59.000Z

233

Cryogenics Vision Workshop for High-Temperature Superconducting Electric Power Systems Proceedings  

SciTech Connect (OSTI)

The US Department of Energy's Superconductivity Program for Electric Systems sponsored the Cryogenics Vision Workshop, which was held on July 27, 1999 in Washington, D.C. This workshop was held in conjunction with the Program's Annual Peer Review meeting. Of the 175 people attending the peer review meeting, 31 were selected in advance to participate in the Cryogenics Vision Workshops discussions. The participants represented cryogenic equipment manufactures, industrial gas manufacturers and distributors, component suppliers, electric power equipment manufacturers (Superconductivity Partnership Initiative participants), electric utilities, federal agencies, national laboratories, and consulting firms. Critical factors were discussed that need to be considered in describing the successful future commercialization of cryogenic systems. Such systems will enable the widespread deployment of high-temperature superconducting (HTS) electric power equipment. Potential research, development, and demonstration (RD and D) activities and partnership opportunities for advancing suitable cryogenic systems were also discussed. The workshop agenda can be found in the following section of this report. Facilitated sessions were held to discuss the following specific focus topics: identifying Critical Factors that need to be included in a Cryogenics Vision for HTS Electric Power Systems (From the HTS equipment end-user perspective) identifying R and D Needs and Partnership Roles (From the cryogenic industry perspective) The findings of the facilitated Cryogenics Vision Workshop were then presented in a plenary session of the Annual Peer Review Meeting. Approximately 120 attendees participated in the afternoon plenary session. This large group heard summary reports from the workshop session leaders and then held a wrap-up session to discuss the findings, cross-cutting themes, and next steps. These summary reports are presented in this document. The ideas and suggestions raised during the Workshop will be used by the DOE Superconductivity Program for Electric Systems in preparing subsequent planning and strategy documents such as a Cryogenic Technology Development Roadmap.

Energetics, Inc.

2000-01-01T23:59:59.000Z

234

Superconducting Transition-Temperature and Other Properties of Thin Metallic-Films  

E-Print Network [OSTI]

March 1975) We point out that the results of (1) Shapoval, for the superconducting transition temperature of a thin film, (2) Nedorezov, for the surface contributions to the density of states, Fermi energy, and specific heat, and (3) Cooper and Hu...) the value of (( 4(r) [ ) increases inside the film, away from the surface, and (b) the Fermi energy also increases. [Here (~4(r)(~) is an average of the square of the electronic wave function. ] These are the two effects which, in conjunction, according...

Allen, Roland E.

1975-01-01T23:59:59.000Z

235

LANL: Superconductivity Technology Center  

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

Sitemap | Lab Home | Phone Sitemap | Lab Home | Phone ABOUT LANL ContactsPhonebookPolicy CenterOrganizationMapsJobs Emergency NEWS LIBRARY JOBS Search Materials Physics & Applications: STC STC Home OUR FOCUS HTS Physics HTS Materials Development HTS Materials Processing Power Applications Electronic Materials FUTURE APPLICATIONS Biomedical Developments Magnetic Levitation Train MHD Ship CONTACTS Center Leader Ken Marken Program Administrator Brenda Espinoza Center Office Location: TA-03, Bdg. 0032, Rm. 141 Exploring technology at STC Superconductivity Technology Center (STC) The Superconductivity Technology Center (STC) coordinates a multidisciplinary program for research, development, and technology transfer in the area of high-temperature superconductivity. Our focus is on effective collaborations with American industry, universities, and other national laboratories to develop electric power and electronic device applications of high-temperature superconductors (HTS).

236

Reactivation and operation of the large six-tesla CFFF superconducting magnet  

SciTech Connect (OSTI)

The second MHD superconducting magnet system constructed at the Argonne National Laboratory, originally intended for use in the coal-fired plasma MHD power generation program, has been in storage at Argonne since its assembly and short-term testing a decade ago. At that time it was energized for only a few days and then decommissioned. The magnet, a 6-T dipole having an effective length of 300 cm and a tapered warm bore of 80 to 100 cm, has recently been reactivated and put into service for sea water MHD propulsion research. This report describes the technical aspects of the reactivation process, as well as the operational characterization of the reconstituted system.

Hill, D.; Libera, J.; Petrick, M.

1992-07-01T23:59:59.000Z

237

Reactivation and operation of the large six-tesla CFFF superconducting magnet  

SciTech Connect (OSTI)

The second MHD superconducting magnet system constructed at the Argonne National Laboratory, originally intended for use in the coal-fired plasma MHD power generation program, has been in storage at Argonne since its assembly and short-term testing a decade ago. At that time it was energized for only a few days and then decommissioned. The magnet, a 6-T dipole having an effective length of 300 cm and a tapered warm bore of 80 to 100 cm, has recently been reactivated and put into service for sea water MHD propulsion research. This report describes the technical aspects of the reactivation process, as well as the operational characterization of the reconstituted system.

Hill, D.; Libera, J.; Petrick, M.

1992-01-01T23:59:59.000Z

238

Magnetic reconnection as a possible heating mechanism of the local high temperature protons within magnetic clouds  

Science Journals Connector (OSTI)

Magnetic clouds have the outstanding observational features of low proton temperature and plasma beta value, but numerous observations show that some magnetic clouds often have local high temperature phenomena...

HengQiang Feng; JieMin Wang

2014-08-01T23:59:59.000Z

239

Electronically competing phases and their magnetic field dependence in electron-doped nonsuperconducting and superconducting Pr{sub 0.88}LaCe{sub 0.12}CuO{sub 4{+-}}{sub {delta}}  

SciTech Connect (OSTI)

We present comprehensive neutron scattering studies of nonsuperconducting and superconducting electron-doped Pr{sub 0.88}LaCe{sub 0.12}CuO{sub 4{+-}}{sub {delta}} (PLCCO). At zero field, the transition from antiferromagnetic (AF) as-grown PLCCO to superconductivity without static antiferromagnetism can be achieved by annealing the sample in pure Ar at different temperatures, which also induces an epitaxial (Pr,La,Ce){sub 2}O{sub 3} phase as an impurity. When the superconductivity first appears in PLCCO, a quasi-two-dimensional (2D) spin-density-wave (SDW) order is also induced, and both coexist with the residual three-dimensional (3D) AF state. A magnetic field applied along the [1,1,0] direction parallel to the CuO{sub 2} plane induces a 'spin-flop' transition, where the noncollinear AF spin structure of PLCCO is transformed into a collinear one. The spin-flop transition is continuous in semiconducting PLCCO, but gradually becomes sharp with increasing doping and the appearance of superconductivity. A c-axis aligned magnetic field that suppresses the superconductivity also enhances the quasi-2D SDW order at (0.5,0.5,0) for underdoped PLCCO. However, there is no effect on the 3D AF order in either superconducting or nonsuperconducting samples. Since the same field along the [1,1,0] direction in the CuO{sub 2} plane has no (or little) effect on the superconductivity (0.5,0.5,0) and (Pr,La,Ce){sub 2}O{sub 3} impurity positions, we conclude that the c-axis field-induced effect is intrinsic to PLCCO and arises from the suppression of superconductivity.

Kang, H.J.; Dai Pengcheng; Mook, H.A.; Argyriou, D.N.; Sikolenko, V.; Lynn, J.W.; Kurita, Y.; Komiya, Seiki; Ando, Yoichi [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States) and Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States); Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States); Hahn-Meitner-Institut, Glienicker Str 100, Berlin D-14109 (Germany); NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Central Research Institute of Electric Power Industry, Komae, Tokyo 201-8511 (Japan)

2005-06-01T23:59:59.000Z

240

Cryocooler Applications for High-Temperature Superconductor Magnetic Bearings  

Science Journals Connector (OSTI)

The efficiency and stability of rotational magnetic suspension systems are enhanced by the use of high-temperature superconductor (HTS) magnetic bearings. Fundamental aspects of ... aspects to be considered are i...

R. C. Niemann; J. R. Hull

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Experience with operation of a large magnet system in the international fusion superconducting magnet test facility  

SciTech Connect (OSTI)

Superconducting toroidal field systems, including coils and ancillaries, are being developed through international collaboration in the Large Coil Task. Focal point is a test facility in Oak Ridge where six coils will be tested in a toroidal array. Shakedown of the facility and preliminary tests of the first three coils (from Japan, Switzerland, and the US) were accomplished in 1984. Useful data were obtained on performance of the helium refrigerator and distribution system, power supplies, control and data acquisition systems and voltages, currents, strains, and acoustic emission in the coils. Performance was generally gratifying except for the helium system, where improvements are being made.

Fietz, W.A.; Ellis, J.F.; Haubenreich, P.N.; Schwenterly, S.W.; Stamps, R.E.

1985-01-01T23:59:59.000Z

242

New superconducting toroidal magnet system for IAXO, the international AXion observatory  

SciTech Connect (OSTI)

Axions are hypothetical particles that were postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP (Charge conjugation and Parity) problem. The new International AXion Observatory (IAXO) will incorporate the most promising solar axions detector to date, which is designed to enhance the sensitivity to the axion-photon coupling by one order of magnitude beyond the limits of the current state-of-the-art detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions into X-ray photons. Inspired by the successful realization of the ATLAS barrel and end-cap toroids, a very large superconducting toroid is currently designed at CERN to provide the required magnetic field. This toroid will comprise eight, one meter wide and twenty one meter long, racetrack coils. The system is sized 5.2 m in diameter and 25 m in length. Its peak magnetic field is 5.4 T with a stored energy of 500 MJ. The magnetic field optimization process to arrive at maximum detector yield is described. In addition, materials selection and their structure and sizing has been determined by force and stress calculations. Thermal loads are estimated to size the necessary cryogenic power and the concept of a forced flow supercritical helium based cryogenic system is given. A quench simulation confirmed the quench protection scheme.

Shilon, I.; Dudarev, A.; Silva, H.; Wagner, U.; Kate, H. H. J. ten [European Organization for Nuclear Research (CERN), CH-1211, Genève 23 (Switzerland)

2014-01-29T23:59:59.000Z

243

Above: Power deposition in the superconducting magnets and the tungsten-carbide + water shield inside them, according to a  

E-Print Network [OSTI]

jet will disrupt the pool, unless mitigated by a splash suppressor. A SOLENOID CAPTURE SYSTEM Collider (MC) Comments Beam Power 4 MW No existing target system will survive at this power Ep 8 GeV yieldAbove: Power deposition in the superconducting magnets and the tungsten-carbide + water shield

McDonald, Kirk

244

Superconducting magnetic energy storage (SMES) program. Progress report, January 1-December 31, 1982  

SciTech Connect (OSTI)

Work reported is on the development of a 30 MJ superconducting magnetic energy storage (SMES) unit, its installation at the Bonneville Power Administration (BPA) Tacoma Substation, and the preliminary site tests in preparation for its use to stabilize power oscillations on the BPA Pacific AC Inertie. The seismic mounting of the 30 MJ superconducting coil to the dewar lid was completed. The manufacture and testing of the nonconducting dewar were completed. The 5 kV vapor cooled leads were assembled and tested. The refrigerator was placed in operation at the Tacoma Substation and tested by making liquid helium in a 500 l dewar. The refrigerator was connected to the coil dewar and is now used for cooling the 30 MJ coil and dewar with extended purification of the circulating helium to remove contaminants. All equipment was shipped and installed at the BPA Tacoma Substation. Assembly of the 30 MJ coil into the nonconducting dewar was done at the BPA Covington facility and transported to the Tacoma Substation. Substation preparation was completed by 11-1-82. BPA, at considerable expense, did an excellent job preparing the site and assisting with the SMES unit installation. All equipment is in place and operable except for components of the computer control and for full refrigeration of the 30 MJ coil. The converter was tested with the output shorted with the input transformers connected to the 13.8 kV. A new schedule for the SMES operation was established.

Rogers, J.D. (comp.)

1983-05-01T23:59:59.000Z

245

Operating experience of the IFSMTF (International Fusion Superconducting Magnet Test Facility) vapor-cooled lead system  

SciTech Connect (OSTI)

The International Fusion Superconducting Magnet Test Facility (IFSMTF) uses six pairs of vapor-cooled leads (VCLs) to introduce electric power to six test coils. Each VCL is housed in a dewar outside the 11-m vacuum vessel and is connected to the coal via a superconducting bus duct;the various VCLs are rated at 12 to 20 kA. Heat loss through the leads constitutes the single largest source of heat load to the cryogenic system. Concerns about voltage breakdown if a coil quenches have led to precautionary measures such as installation of a N/sub 2/-purged box near the top of the lead and shingles to collect water that condenses on the power buses. A few joints between power buses and VCLs were found to be inadequate during preliminary single-coil tests. This series of tests also pointed to the need for automatic control of helium flow through the leads. This was achieved by using the resistance measurements of the leads to control flow valves automatically. By the time full-array tests were started, a working scheme had developed that required little attention to the leads and that had little impact on the refrigerator between zero and full current to the coils. The operating loss of the VCLs at full current is averaging at about 7.4 gs of warm flow and 360 W of cold-gas return load. These results are compared with predictions that were based on earlier tests. 4 refs., 6 figs

Lue, J.W.; Fehling, D.T.; Fietz, W.A.; Lubell, M.S.; Luton, J.N.; Schwenterly, S.W.; Shen, S.S.; Stamps, R.E.; Thompson, D.H.; Wilson, C.T.

1987-01-01T23:59:59.000Z

246

Thermal Performance of the Supporting System for the Large Hadron Collider (LHC) Superconducting Magnets  

E-Print Network [OSTI]

The LHC collider will be composed of approximately 1700 main ring superconducting magnets cooled to 1.9 K in pressurised superfluid helium and supported within their cryostats on low heat in-leak column-type supports. The precise positioning of the heavy magnets and the stringent thermal budgets imposed by the machine cryogenic system, require a sound thermo-mechanical design of the support system. Each support is composed of a main tubular thin-walled structure in glass-fibre reinforced epoxy resin, with its top part interfaced to the magnet at 1.9 K and its bottom part mounted onto the cryostat vacuum vessel at 293 K. In order to reduce the conduction heat in-leak at 1.9 K, each support mounts two heat intercepts at intermediate locations on the column, both actively cooled by cryogenic lines carrying helium gas at 4.5-10 K and 50-65 K. The need to assess the thermal performance of the supports has lead to setting up a dedicated test set-up for precision heat load measurements on prototype supports. This pa...

Castoldi, M; Parma, Vittorio; Vandoni, Giovanna

1999-01-01T23:59:59.000Z

247

Levitation pressure and friction losses in superconducting bearings  

DOE Patents [OSTI]

A superconducting bearing having at least one permanent magnet magnetized with a vertical polarization. The lower or stator portion of the bearing includes an array of high-temperature superconducting elements which are comprised of a plurality of annular rings. An annular ring is located below each permanent magnet and an annular ring is offset horizontally from at least one of the permanent magnets. The rings are composed of individual high-temperature superconducting elements located circumferentially along the ring. By constructing the horizontally-offset high-temperature superconducting ring so that the c-axis is oriented in a radial direction, a higher levitation force can be achieved. Such an orientation will also provide substantially lower rotational drag losses in the bearing.

Hull, John R. (Downers Grove, IL)

2001-01-01T23:59:59.000Z

248

Low temperature magnetic transitions of single crystal HoBi  

SciTech Connect (OSTI)

We present resistivity, specific heat and magnetization measurements in high quality single crystals of HoBi, with a residual resistivity ratio of 126. We find, from the temperature and field dependence of the magnetization, an antiferromagnetic transition at 5.7 K, which evolves, under magnetic fields, into a series of up to five metamagnetic phases.

Fente, A. [Universidad Autonoma de Madrid; Suderow, H. [Universidad Autonoma de Madrid; Vieira, S. [Universidad Autonoma de Madrid; Nemes, N. M. [Instituto de Ciencia de Materiales de Madrid; Garcia-Hernandez, M. [Instituto de Ciencia de Materiales de Madrid; Budko, Sergei L. [Ames Laboratory; Canfield, Paul C. [Ames Laboratory

2013-09-04T23:59:59.000Z

249

DESIGN OF SUPERCONDUCTING COMBINED FUNCTION MAGNETS FOR THE 50 GEV PROTON BEAM LINE FOR THE J-PARC NEUTRINO EXPERIMENT.  

SciTech Connect (OSTI)

Superconducting combined function magnets will be utilized for the 50GeV-750kW proton beam line for the J-PARC neutrino experiment and an R and D program has been launched at KEK. The magnet is designed to provide a combined function with a dipole field of 2.59 T and a quadrupole field of 18.7 T/m in a coil aperture of 173.4 mm. A single layer coil is proposed to reduce the fabrication cost and the coil arrangement in the 2-D cross-section results in left-right asymmetry. This paper reports the design study of the magnet.

WANDERER,P.; ET AL.

2003-06-15T23:59:59.000Z

250

Improved Magnetic Field Generation Efficiency and Higher Temperature Spheromak Plasmas  

SciTech Connect (OSTI)

New understanding of the mechanisms governing the observed magnetic field generation limits on the sustained spheromak physics experiment has been obtained. Extending the duration of magnetic helicity injection during the formation of a spheromak and optimizing the ratio of injected current to bias flux produce higher magnetic field plasmas with record spheromak electron temperatures. To explore magnetic field buildup efficiency limits, the confinement region geometry was varied resulting in improved field buildup efficiencies.

Wood, R D; Hill, D N; McLean, H S; Hooper, E B; Hudson, B F; Moller, J M; Romero-Talamas, C A

2008-09-15T23:59:59.000Z

251

Improved magnetic field generation efficiency and higher temperature spheromak plasmas  

Science Journals Connector (OSTI)

New understanding of the mechanisms governing the observed magnetic field generation limits on the sustained spheromak physics experiment has been obtained. Extending the duration of magnetic helicity injection during the formation of a spheromak and optimizing the ratio of injected current to bias flux produce higher magnetic field plasmas with record spheromak electron temperatures. To explore magnetic field buildup efficiency limits, the confinement region geometry was varied resulting in improved field buildup efficiencies.

R.D. Wood; D.N. Hill; H.S. McLean; E.B. Hooper; B.F. Hudson; J.M. Moller; C.A. Romero-Talamás

2009-01-01T23:59:59.000Z

252

The hybrid lattice of KxFe2-ySe2: why superconductivity and magnetism can coexist  

SciTech Connect (OSTI)

It is always puzzling to observe superconductivity in atomically disordered systems as it contradicts the very nature of electronic state coherence, but nevertheless happens as in amorphous alloys1. How can superconductivity survive under conditions for strong electron localization2? To understand the effects of disorder, a family of recently discovered Fe-based superconductors3-6 is investigated, the KxFe2-ySe2 (7) where nominally, superconductivity is observed between a semi-metallic region below 0.7 < x < 0.85 insulating and antiferromagnetic region above8,9. By probing the local structure we observe that superconductivity emerges in a locally distorted Fe sublattice that accommodates two kinds of bond environments, forming a double-well distribution. Consisting of short bonds which are metallic in nature and of long ones which are insulating and antiferromagnetic, their distribution changes with x. Even though crystallographically the atomic structure changes slowly on average by adding K10, a continuous transition from the metallic (short) to the insulating (long) Fe bonds is observed across this region. What is unique to this system s superconducting state is the presence of the double-well distribution in equal proportions, in contrast to other Fe-based materials where only one kind of Fe bond is present. This suggests that in this superconducting system, superconductivity is intertwined with magnetism, appearing at the crossover from metallic to insulating conditions and is not due to phase separation. Such a hybrid state is most likely present in cuprate superconductors as well and may be more common than previously expected.

Louca, Despina [University of Virginia] [University of Virginia; Park, Keeseong [University of Virginia] [University of Virginia; Li, Bing [University of Virginia] [University of Virginia; Neuefeind, Joerg C [ORNL] [ORNL; Yan, Jiaqiang [ORNL] [ORNL

2013-01-01T23:59:59.000Z

253

Interplay of superconductivity, magnetism, and density waves in rare-earth tritellurides and iron-based superconducting materials  

E-Print Network [OSTI]

107 Figure IV.3: Electrical resistance R vs. temperature TRoom-temperature electrical resistance vs. applied load andanvil cell (DAC) electrical resistivity vs. temperature for

Zocco, Diego Andrés

2011-01-01T23:59:59.000Z

254

Contribution of ion beam analysis methods to the development of 2nd generation high temperature superconducting (HTS) wires  

SciTech Connect (OSTI)

One of the crucial steps in the second generation high temperature superconducting wire program was development of the buffer layer architecture. The architecture designed at the Superconductivity Technology Center at Los Alamos National Laboratory consists of several oxide layers wherein each layer plays a specific role, namely: nucleation layer, diffusion barrier, biaxially textured template, and an intermediate layer with a good match to the lattice parameter of superconducting Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} (YBCO) compound. This report demonstrates how a wide range of ion beam analysis techniques (SIMS, RBS, channeling, PIXE, PIGE, NRA, ERD) was employed for analysis of each buffer layer and the YBCO films. These results assisted in understanding of a variety of physical processes occurring during the buffet layer fabrication and helped to optimize the buffer layer architecture as a whole.

Usov, Igor O [Los Alamos National Laboratory; Arendt, Paul N [Los Alamos National Laboratory; Stan, Liliana [Los Alamos National Laboratory; Holesinger, Terry G [Los Alamos National Laboratory; Foltyn, Steven R [Los Alamos National Laboratory; Depaula, Raymond F [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

255

Control of magnetic, nonmagnetic, and superconducting states in annealed Ca(Fe1?xCox)2As2  

SciTech Connect (OSTI)

We have grown single-crystal samples of Co substituted CaFe2As2 using an FeAs flux and systematically studied the effects of annealing/quenching temperature on the physical properties of these samples. Whereas the as-grown samples (quenched from 960 ?C) all enter the collapsed tetragonal phase upon cooling, annealing/quenching temperatures between 350 and 800 ?C can be used to tune the system to low-temperature antiferromagnetic/orthorhomic or superconducting states as well. The progression of the transition temperature versus annealing/quenching temperature (T-Tanneal) phase diagrams with increasing Co concentration shows that, by substituting Co, the antiferromagnetic/orthorhombic and the collapsed tetragonal phase lines are separated and bulk superconductivity is revealed. We established a 3D phase diagram with Co concentration and annealing/quenching temperature as two independent control parameters. At ambient pressure, for modest x and Tanneal values, the Ca(Fe1?xCox)2As2 system offers ready access to the salient low-temperature states associated with Fe-based superconductors: antiferromagnetic/orthorhombic, superconducting, and nonmagnetic/collapsed tetragonal.

Ran, Sheng; Budko, Serguei L.; Straszheim, Warren E.; Soh, Jing-Han; Kim, Min Gyu; Kreyssig, Andreas; Goldman, Alan I.; Canfield, Paul C.

2012-06-22T23:59:59.000Z

256

ESS 2012 Peer Review - Superconducting Magnet ESS with Direct Power Electronics Interface - V.R. Ramanan, ABB  

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

© ABB Group © ABB Group October 5, 2012 | Slide 1 Superconducting Magnet Energy Storage System with Direct Power Electronics Interface Project Goal  Competitive, fast response, grid-scale MWh superconducting magnet energy storage (SMES) system  Demonstrated through a small scale prototype, (20 kW, 2.5 MJ) and direct connection power electronics converter (with Si-based devices) V.R. Ramanan, ABB US Corporrate Research Center GRIDS SMES SYSTEM SMES Coil MV Feeder Power Converter ABB Brookhaven NL 2G HTS Wire SuperPower MV/LV MV/LV MV/LV HV/MV Wind Park Solar Park Transmission Line Converter & System Design/Prototyping LV Loads University of Houston ABB Project Update  Issues related to SMES system integration being addressed  Project slightly behind schedule; on budget

257

Magnetic field stabilization by temperature control of an azimuthally varying field cyclotron magnet  

SciTech Connect (OSTI)

A magnetic field drift, gradual decrease of the order of 10{sup -4} in several tens of hours, was observed with the beam intensity decrease in an operation of an azimuthally varying field (AVF) cyclotron. From our experimental results, we show that the temperature increase of the magnet iron by the heat transfer from the excitation coils can induce such change of the magnetic field as to deteriorate the beam quality. The temperature control of the magnet iron was realized by thermal isolation between the main coil and the yoke and by precise control of the cooling water temperature of the trim coils attached to the pole surfaces in order to prevent temperature change of the magnet iron. The magnetic field stability of {+-}5x10{sup -6} and the beam intensity stability of {+-}2% have been achieved by this temperature control.

Okumura, S.; Arakawa, K.; Fukuda, M.; Nakamura, Y.; Yokota, W.; Ishimoto, T.; Kurashima, S.; Ishibori, I.; Nara, T.; Agematsu, T.; Sano, M.; Tachikawa, T. [Japan Atomic Energy Research Institute (JAERI), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Sumitomo Heavy Industries, Ltd. (SHI), 5-2 Soubiraki, Niihama, Ehime 792-8588 (Japan)

2005-03-01T23:59:59.000Z

258

Giant Overlap between the Magnetic and Superconducting Phases of CeAu2Si2 under Pressure  

Science Journals Connector (OSTI)

High pressure provides a powerful means for exploring unconventional superconductivity which appears mostly on the border of magnetism. Here, we report the discovery of pressure-induced heavy-fermion superconductivity up to 2.5 K in the antiferromanget CeAu2Si2 (TN?10??K). Remarkably, the magnetic and superconducting phases are found to overlap across an unprecedentedly wide pressure interval from 11.8 to 22.3 GPa. Moreover, both the bulk Tc and TM are strongly enhanced when increasing the pressure from 16.7 to 20.2 GPa. Tc reaches a maximum at a pressure slightly below pc?22.5??GPa, at which magnetic order disappears. Furthermore, the scaling behavior of the resistivity provides evidence for a continuous delocalization of the Ce 4f electrons associated with a critical end point lying just above pc. We show that the maximum Tc of CeAu2Si2 actually occurs at almost the same unit-cell volume as that of CeCu2Si2 and CeCu2Ge2, and when the Kondo and crystal-field splitting energies become comparable. Dynamical mean-filed theory calculations suggest that the peculiar behavior in pressurized CeAu2Si2 might be related to its Ce?4f orbital occupancy. Our results not only provide a unique example of the interplay between superconductivity and magnetism, but also underline the role of orbital physics in understanding Ce-based heavy-fermion systems.

Z. Ren; L.?V. Pourovskii; G. Giriat; G. Lapertot; A. Georges; D. Jaccard

2014-09-26T23:59:59.000Z

259

STATEMENT OF CONSIDERATIONS REQUEST BY DUPONT SUPERCONDUCTIVITY FOR AN ADVANCE  

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

DUPONT SUPERCONDUCTIVITY FOR AN ADVANCE DUPONT SUPERCONDUCTIVITY FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN PATENT RIGHTS UNDER DOE CONTRACT NO. DE-FC36-99GO10287; W(A)-99-008; CH-1002 The Petitioner, DuPont Superconductivity (hereinafter "DuPont"), has requested a waiver of domestic and foreign patent rights for all subject inventions arising from its participation under the above referenced contract entitled "High Temperature Superconducting Reciprocating Magnetic Separator". This contract relates to the construction of 1/4 commercial scale High Temperature Superconducting (hereinafter "HTS") Reciprocating Magnetic Separations Unit for the purification ofkaoline clay and titanium dioxide. It is anticipated that this project will be performed in three phases, over a period of

260

MagRad: A code to optimize the operation of superconducting magnets in a radiation environment  

SciTech Connect (OSTI)

A powerful computational tool, called MagRad, has been developed which optimizes magnet design for operation in radiation fields. Specifically, MagRad has been used for the analysis and design modification of the cable-in-conduit conductors of the TF magnet systems in fusion reactor designs. Since the TF magnets must operate in a radiation environment which damages the material components of the conductor and degrades their performance, the optimization of conductor design must account not only for start-up magnet performance, but also shut-down performance. The degradation in performance consists primarily of three effects: reduced stability margin of the conductor; a transition out of the well-cooled operating regime; and an increased maximum quench temperature attained in the conductor. Full analysis of the magnet performance over the lifetime of the reactor includes: radiation damage to the conductor, stability, protection, steady state heat removal, shielding effectiveness, optimal annealing schedules, and finally costing of the magnet and reactor. Free variables include primary and secondary conductor geometric and compositional parameters, as well as fusion reactor parameters. A means of dealing with the radiation damage to the conductor, namely high temperature superconductor anneals, is proposed, examined, and demonstrated to be both technically feasible and cost effective. Additionally, two relevant reactor designs (ITER CDA and ARIES-II/IV) have been analyzed. Upon addition of pure copper strands to the cable, the ITER CDA TF magnet design was found to be marginally acceptable, although much room for both performance improvement and cost reduction exists. A cost reduction of 10-15% of the capital cost of the reactor can be achieved by adopting a suitable superconductor annealing schedule. In both of these reactor analyses, the performance predictive capability of MagRad and its associated costing techniques have been demonstrated.

Yeaw, C.T.

1995-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Magnetic moments of octet baryons at finite density and temperature  

E-Print Network [OSTI]

We investigate the change of magnetic moments of octet baryons in nuclear matter at a finite density and temperature. Quark-meson coupling models are employed in describing properties of octet baryons and their interactions. Magnetic moments of octet baryons are found to increase non-negligibly as density and temperature increase, and we find that temperature dependence can be strongly correlated with the quark-hadron phase transition. Model dependence is also examined by comparing the results from the quark-meson coupling (QMC) model to those by the modified QMC (MQMC) model where the bag constant is assumed to depend on density. Both models predict sizable dependence on density and temperature, but the MQMC model shows a more drastic change of magnetic moments. Feasible changes of the nucleon mass by strong magnetic fields are also reported in the given models.

C. Y. Ryu; C. H. Hyun; M. -K. Cheoun

2010-08-12T23:59:59.000Z

262

30-MJ superconducting magnetic-energy-storage stabilizing system: an overview  

SciTech Connect (OSTI)

The 30-MJ superconducting magnetic-energy-storage (SMES) system was devised as an alternate means to modulate the Bonneville Power Administration (BPA) Pacific AC Intertie, a part of the Western US Power System, to prevent undamped power oscillations at 0.35 Hz that were observed to be associated with high power transmission. The SMES system was installed at the BPA Tacoma Substation and successfully operated as an experimental device to initiate tests to determine power system dynamics, to investigate their variability, to assess system response to SMES modulation with a major variable load, and to use SMES to develop stability-control techniques. The system has been operated at frequencies of 0.1 to 1.0 Hz at power levels of +- 8.3 MW with a parallel modulation of the converter bridges and up to 9.5 MW reactive power together with +- 4.5 MW real power in constant VAR mode with buck-boost modulation of the bridges. The coil has been charged at a maximum rate of 11.8 MW. Operation of the SMES system is now under BPA jurisdiction, and all hardware has been transferred to BPA.

Roger, J.D.; Boenig, H.J.; Dean, J.W.; Schermer, R.I.; Annestrand, S.A.; Hauer, J.F.; Miller, B.L.

1983-01-01T23:59:59.000Z

263

Stability and quench protection of high-temperature superconductors  

E-Print Network [OSTI]

In the design and operation of a superconducting magnet, stability and protection are two key issues that determine the magnet's reliability and safe operation. Although the high-temperature superconductor (HTS) is considered ...

Ang, Ing Chea

2006-01-01T23:59:59.000Z

264

Magnetism and superconductivi[t]y in Pr-based filled skutterudite arsenides  

E-Print Network [OSTI]

1.3 Magnetism . . . . .1.3.3 Itinerant Magnetism . . . . . . . . . . .3.3 Magnetism . . . . . . . . . . . . . . . . . . . . . 3.4

Sayles, Todd Allen

2008-01-01T23:59:59.000Z

265

Investigating the relationship between the superconducting and pseudogap states of the high-temperature superconductor Bi-2201 using scanning tunneling microscopy  

E-Print Network [OSTI]

There is considerable controversy regarding the nature of the relationship between the superconducting and pseudogap states of high-temperature superconductors. Although there exist a large number of theories regarding ...

Boyer, Michael Christopher

2008-01-01T23:59:59.000Z

266

Experimental Investigation of Magnetic, Superconducting, and other Phase Transitions in novel F-Electron Materials at Ultra-high Pressures - Final Progress Report  

SciTech Connect (OSTI)

This grant, entitled “Experimental investigation of magnetic, superconducting and other phase transitions in novel f-electron materials at ultrahigh pressures,” spanned the funding period from May 1st, 2003 until April 30th, 2006. The major goal of this grant was to develop and utilize an ultrahigh pressure facility—capable of achieving very low temperatures, high magnetic fields, and extreme pressures as well as providing electrical resistivity, ac susceptibility, and magnetization measurement capabilities under pressure—for the exploration of magnetic, electronic, and structural phases and any corresponding interactions between these states in novel f-electron materials. Realizing this goal required the acquisition, development, fabrication, and implementation of essential equipment, apparatuses, and techniques. The following sections of this report detail the establishment of an ultrahigh pressure facility (Section 1) and measurements performed during the funding period (Section 2), as well as summarize the research project (Section 3), project participants and their levels of support (Section 4), and publications and presentations (Section 5).

Maple, Brian; Jeffires, Jason

2006-07-28T23:59:59.000Z

267

Superconducting phase transitions in ultrathin TiN film.  

SciTech Connect (OSTI)

Building on the complete account of quantum contributions to conductivity, we demonstrate that the resistance of thin superconducting films exhibits a non-monotonic temperature behavior due to the competition between weak localization, electron-electron interaction, and superconducting fluctuations. We show that superconducting fluctuations give rise to an appreciable decrease in the resistance even at temperatures well exceeding the superconducting transition temperature, T{sub c}, with this decrease being dominated by the Maki-Thompson process. The transition to a global phase-coherent superconducting state occurs via the Berezinskii-Kosterlitz-Thouless (BKT) transition, which we observe both by power-law behavior in current-voltage characteristics and by flux flow transport in the magnetic field. The ratio T{sub BKT}/T{sub c} follows the universal relation.

Baturina, T. I.; Postolova, S. V.; Mironov, A. Yu.; Glatz, A.; Baklanov, M. R.; Vinokur, V. M. (Materials Science Division); (A. V. Rzhanov Inst. Semicond. Phys.); (IMEC)

2012-01-01T23:59:59.000Z

268

Effect of the size of GBCO-Ag secondary magnet on the static forces performance of linear synchronous motors  

E-Print Network [OSTI]

Bulk high temperature superconductor magnets (HTSM) have a higher flux-generating capability compared to conventional permanent magnets (PMs). These materials potentially can be used in high temperature superconducting (HTS) linear synchronous...

Zheng, Jun; Shi, Yunhua; He, Dabo; Jing, Hailian; Li, Jing; Deng, Zigang; Wang, Suyu; Wang, Jiasu; Cardwell, David A.

2014-01-01T23:59:59.000Z

269

Proceedings of the fourth international conference and exhibition: World Congress on superconductivity. Volume 1  

SciTech Connect (OSTI)

The goals of the World Congress on Superconductivity (WCS) have been to establish and foster the development and commercial application of superconductivity technology on a global scale by providing a non-adversarial, non-advocacy forum where scientists, engineers, businessmen and government personnel can freely exchange information and ideas on recent developments and directions for the future of superconductive research. Sessions were held on: accelerator technology, power and energy, persistent magnetic fields, performance characterization, physical properties, fabrication methodology, superconductive magnetic energy storage (SMES), thin films, high temperature materials, device applications, wire fabrication, and granular superconductors. Individual papers are indexed separately.

Krishen, K.; Burnham, C. [eds.] [National Aeronautics and Space Administration, Houston, TX (United States). Lyndon B. Johnson Space Center

1994-12-31T23:59:59.000Z

270

Methods to detect faulty splices in the superconducting magnet system of the LHC  

SciTech Connect (OSTI)

The incident of 19 September 2008 at the LHC was caused by a faulty inter-magnet splice of about 200 n{Omega} resistance. Cryogenic and electrical techniques have been developed to detect other abnormal splices, either between or inside the magnets. The existing quench protection system can be used to detect internal splices with R > 20 n{Omega}. Since this system does not cover the bus between magnets, the cryogenic system is used to measure the rate of temperature rise due to ohmic heating. Accuracy of a few mK/h, corresponding to a few Watts, has been achieved, allowing detection of excess resistance, if it is more than 40 n{Omega} in a cryogenic subsector (two optical cells). Follow-up electrical measurements are made in regions identified by the cryogenic system. These techniques have detected two abnormal internal magnet splices of 100 n{Omega} and 50 n{Omega} respectively. In 2009, this ad hoc system will be replaced with a permanent one to monitor all splices at the n{Omega} level.

Bailey, R.; Bellesia, B.; Lasheras, N.Catalan; Dahlerup-Petersen, K.; Denz, R.; Robles, C.; Koratzinos, M.; Pojer, M.; Ponce, L.; Saban, R.; Schmidt, R.; /CERN /Fermilab /Moscow, INR /Cracow, INP

2009-05-01T23:59:59.000Z

271

Temperature Instability in High-Tc Superconducting Wire Exposed to Thermal Disturbance  

Science Journals Connector (OSTI)

Abstract High-Tc superconductor wires/ conductors of longer lengths have emerged as one of the most promising candidates for several useful applications such as in utilities and in current lead powering large magnet system. These conductors are liquid nitrogen cooled and are much cheaper to operate. In the event of intrinsic thermal instability or cooling failure, irreversible transition to normal state may occur. These normal zones may propagate rapidly enough to cause transient heating leading to local ‘hot spot’ and resulting in damage to the conductor/ magnet. In this paper, the mathematical formulation to determine the temperature distribution throughout the superconductor wire subjected to such transient disturbance is illustrated. The solution to the problem is achieved by using the method of separation of variables based on physically relevant initial conditions. The results are obtained in the series form in terms of Bessel's functions and are illustrated numerically for a technical yttrium barium copper oxide (YBCO) superconductor wire. Also it is found that even for a steady state heat transfer of 500 W m–2 K–1, the conductor temperature rises above Tc in less than 10 sec of the thermal disturbance.

Ziauddin Khan; Subrata Pradhan; Irfan Ahmed

2014-01-01T23:59:59.000Z

272

Measurements of magnetic screening lengths in superconducting Nb thin films by polarized neutron reflectometry  

Science Journals Connector (OSTI)

Polarized neutron reflectivity measurements have been performed on two polycrystalline niobium films grown on silicon substrates. The samples were characterized with x-ray diffraction and reflection, electrical resistivity, and unpolarized neutron reflection measurements. For the film of 310 nm thickness, polarized neutron reflectivity measurements were carried out on both the Si side as well as the vacuum side, and we found that substantially higher quality data could be obtained from the Si side due to the enhanced contrast between the weak diamagnetic scattering and the nuclear scattering from the films. A large number of interference fringes from the waves reflected from the front and back surfaces of the film could be observed, attesting to the high quality and flatness of the sample. The vacuum-Nb interface had a surface roughness of ??3.4 nm, while the Nb-Si interface was nearly atomically smooth. We also carried out an experiment on a 300 nm-thick film of YBa2Cu3O7, but the roughness was so severe that no interference fringes could be observed, and reliable measurements of ? could not be obtained. The magnetic screening length for the Nb films was measured to be ?=110±2 nm for the sample with an electron mean free path l=10 nm, and ?=55±2 nm for the sample with l=35 nm. Taking into account the effects of crystalline defects and impurities, we obtain the intrinsic London penetration depth in superconducting Nb to be ?L=43±8 nm at T=4.5 K. This result is in good agreement with that of Felcher et al.

Huai Zhang; J. W. Lynn; C. F. Majkrzak; S. K. Satija; J. H. Kang; X. D. Wu

1995-10-01T23:59:59.000Z

273

Magnetically polarized Ir dopant atoms in superconducting Ba(Fe1?xIrx)2As2  

SciTech Connect (OSTI)

We investigate the magnetic polarization of the Ir 5d dopant states in the pnictide superconductor Ba(Fe1?xIrx)2As2 with x=0.027(2) using Ir L3 edge x-ray resonant magnetic scattering (XRMS). Despite the fact that doping partially suppresses the antiferromagnetic transition, we find that magnetic order survives around the Ir dopant sites. The Ir states are magnetically polarized with commensurate stripe-like antiferromagnetic order and long correlations lengths, ?mag>2800 and >850 Å, in the ab plane and along the c axis, respectively, driven by their interaction with the Fe spins. This Ir magnetic order persists up to the Néel transition of the majority Fe spins at TN=74(2) K. At 5 K we find that magnetic order coexists microscopically with superconductivity in Ba(Fe1?xIrx)2As2. The energy dependence of the XRMS through the Ir L3 edge shows a non-Lorentzian line shape, which we explain in terms of interference between Ir resonant scattering and Fe nonresonant magnetic scattering.

Dean, M.P.M.; Kim, M.G.; Kreyssig, A.; Kim, J.W.; Liu, X.; Ryan, P.J.; Thaler, A.; Budko, S.L.; Strassheim, W.; Canfield, P.C.; Hill, J.P.; Goldman, A.I.

2012-04-25T23:59:59.000Z

274

Study on effect of annealing conditions on structural, magnetic and superconducting properties of MgB{sub 2} bulk samples  

SciTech Connect (OSTI)

Effect of annealing conditions on structural, magnetic and superconducting properties of Magnesium Diboride (MgB{sub 2}) bulk superconductor samples prepared by solid state route method are compared. The samples are made by taking Magnesium and Boron powders in stoichiometric ratio, grounded well and pelletized at pressure of about 10Tonnes. These pellets are annealed in both Argon and vacuum environment separately up to 800°c for two hours. Both the samples show clear superconducting transition at Tc ? 38 k. This is further conformed by AC/DC magnetization (M-T), Resistivity [? (T, H)] measurements under magnetic field up to 14 Tesla as well. Rietveld refinement of X-ray diffraction of both samples conformed the MgB{sub 2} phase formation with P6/mmm space group symmetry. Scanning Electron Microscopy images of the surface revile more agglomeration of grains in case of Argon annealed samples. This result in more critical current density (J{sub c}) of Argon annealed samples than vacuum annealed one calculated from Bean's critical state model. This high Jc is explained in terms of more inter grain connectivity for Argon annealed sample than vacuum annealed sample.

Phaneendra, Konduru, E-mail: phaneendra-50@yahoo.com; Asokan, K., E-mail: phaneendra-50@yahoo.com; Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, Vasanth Kung, New Delhi-110067 (India); Awana, V. P. S. [Quantum Phenomena and Applications, National Physical Laboratory, K S Krishnan Marg, New Delhi-110012 (India); Sastry, S. Sreehari [Dept. of Physics, Acharya Nagarjuna University, Guntur-522510 (India)

2014-04-24T23:59:59.000Z

275

Secrets of superconductivity revealed  

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

Secrets of superconductivity revealed Secrets of superconductivity revealed Secrets of superconductivity revealed The superconducting material Cerium-Colbalt-Indium5 reveals new secrets about how superconductivity and magnetism can be related. January 3, 2014 Simon Gerber, first author of the publication on the superconducting properties of CeCoIn5 at the Morpheus instrument of the Spallation Neutron Source SINQ in Switzerland. (Photo: Paul Scherrer Institute/Markus Fischer) Simon Gerber, first author of the publication on the superconducting properties of CeCoIn5 at the Morpheus instrument of the Spallation Neutron Source SINQ in Switzerland. (Photo: Paul Scherrer Institute/Markus Fischer) "Superconductivity continues to give new surprises. As its secrets are revealed, we learn more about the quantum world of electrons and can begin

276

Secrets of superconductivity revealed  

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

Secrets of superconductivity revealed Secrets of superconductivity revealed Secrets of superconductivity revealed The superconducting material Cerium-Colbalt-Indium5 reveals new secrets about how superconductivity and magnetism can be related. January 3, 2014 Simon Gerber, first author of the publication on the superconducting properties of CeCoIn5 at the Morpheus instrument of the Spallation Neutron Source SINQ in Switzerland. (Photo: Paul Scherrer Institute/Markus Fischer) Simon Gerber, first author of the publication on the superconducting properties of CeCoIn5 at the Morpheus instrument of the Spallation Neutron Source SINQ in Switzerland. (Photo: Paul Scherrer Institute/Markus Fischer) "Superconductivity continues to give new surprises. As its secrets are revealed, we learn more about the quantum world of electrons and can begin

277

Experimental Investigation of Magnetic Superconducting, and other Phase Transitions in Novel f-Electron Materials at Ultra-high Pressures Using Designer Diamond Anvils  

SciTech Connect (OSTI)

Pressure is a powerful control parameter, owing to its ability to affect crystal and electronic structure without introducing defects, for the investigation of condensed matter systems. Some f-electron, heavy-fermion materials display interesting and novel behavior when exposed to pressures achievable with conventional experimental techniques; however, a growing number of condensed matter systems require extreme conditions such as ultrahigh pressures, high magnetic fields, and ultralow temperatures to sufficiently explore the important properties. To that end, we have been funded to develop an ultrahigh pressure facility at the University of California, San Diego (UCSD) in order to investigate superconductivity, magnetism, non-Fermi liquid behavior, and other phenomena under extreme conditions. Our goals for the second year of this grant were as follows: (a) perform electrical resistivity measurements on novel samples at a myriad of pressures using conventional piston-cylinder techniques, Bridgman anvil techniques, and diamond anvil cell technology; (b) install, commission, and operate an Oxford Kelvinox MX-100 dilution refrigerator for access to ultralow temperatures and high magnetic fields. (c) continue the development of diamond anvil cell (DAC) technology. During the past year, we have successfully installed the Oxford Kelvinox MX-100 dilution refrigerator and verified its operability down to 12 mK. We have begun an experimental program to systematically investigate the f-electron compound URu2Si2 under pressure and in the presence of magnetic fields. We have also continued our collaborative work with Sam Weir at Lawrence Livermore National Laboratory (LLNL) on Au4V and implemented a new corollary study on Au1-xVx using ultrahigh pressures. We have continued developing our DAC facility by designing and constructing an apparatus for in situ pressure measurement as well as designing high pressure cells. This report serves to highlight the progress we have made towards developing an ultrahigh pressure research facility at UCSD, the research performed in the past year, as well as future directions we plan to pursue.

Maple, M. Brian

2005-09-13T23:59:59.000Z

278

Large magnetic penetration depth and thermal fluctuations in a superconducting Ca10(Pt3As8)[(Fe1 xPtx)2As2]5 (x = 0.097) single crystal  

SciTech Connect (OSTI)

We have measured the temperature dependence of the absolute value of the magnetic penetration depth {lambda}(T) in a Ca{sub 10}(Pt{sub 3}As{sub 8})[(Fe{sub 1-x}Pt{sub x}){sub 2}As{sub 2}]{sub 5} (x = 0.097) single crystal using a low-temperature magnetic force microscope (MFM). We obtain {lambda}{sub ab}(0) {approx} 1000 nm via extrapolating the data to T = 0. This large {lambda} and pronounced anisotropy in this system are responsible for large thermal fluctuations and the presence of a liquid vortex phase in this low-temperature superconductor with a critical temperature of 11 K, consistent with the interpretation of the electrical transport data. The superconducting parameters obtained from {lambda} and coherence length {zeta} place this compound in the extreme type II regime. Meissner responses (via MFM) at different locations across the sample are similar to each other, indicating good homogeneity of the superconducting state on a submicron scale.

Kim J.; Nazaretski E.; Ronning, F.; Haberkorn, N.; Civale, L.; Ni, N.; Cava, R.J.; Thompson, J.D.; Movshovich, R.

2012-05-18T23:59:59.000Z

279

Increased superconducting transition temperature of a niobium thin-film proximity-coupled to gold nanoparticles using linking organic molecules  

E-Print Network [OSTI]

The superconducting critical temperature, TC, of thin Nb films is significantly modified when gold nanoparticles (NPs) are chemically linked to the Nb film, with a consistent enhancement when using 3 nm long disilane linker molecules. The TC increases by up to 10% for certain linker length and NPs size. No change is observed when the nanoparticles are physisorbed with non-linking molecules. Electron tunneling spectra acquired on the linked NPs below TC typically exhibit zero-bias peaks. We attribute these results to a pairing mechanism coupling electrons in the Nb and the NPs, mediated by the organic linkers.

Eran Katzir; Shira Yochelis; Felix Zeides; Nadav Katz; Yoav Kalcheim; Oded Millo; Gregory Leitus; Yuri Myasodeyov; Boris Ya. Shapiro; Ron Naaman; Yossi Paltiel

2011-11-02T23:59:59.000Z

280

National High Magnetic Field Laboratory Audio Dictionary: Quench  

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

stream the Magnet Minute Bob Walsh Associated Links What's a Superconducting Magnet? (audio file) What's Superconductivity? (audio file) Superconductivity: Current in a Cape and...

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

A New Mechanism for Nuclear Magnetic Relaxation in d-wave Superconduct...  

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

Mechanism for Nuclear Magnetic Relaxation in d-wave Superconductors in High Magnetic Fields Robert E. Throckmorton and Oskar Vafek (FSU, NHMFL) Robert E. Throckmorton and Oskar...

282

Fusion Engineering and Design 7579 (2005) 2932 First integrated test of the superconducting magnet systems  

E-Print Network [OSTI]

Fusion Engineering and Design 75­79 (2005) 29­32 First integrated test of the superconducting of Applied Physics and Applied Mathematics Room 210 S.W., Mudd Building, New York, NY 10027, USA Available at the center of a 5 m diameter, 3 m tall vacuum chamber. The Floating coil (F-coil) is designed for a maximum

283

Cryostat design and analysis of the superconducting magnets for Jefferson Lab's 11-GEV/C super high momentum spectrometer  

SciTech Connect (OSTI)

This paper describes the mechanical design and analysis of the cryostats for the two cos(2theta) quadrupoles and the cos(theta) dipole. All the magnets are currently being bid for commercial fabrication. The results of finite element analysis for the magnet cryostat helium vessels and outer vacuum chambers which investigate the mechanical integrity under maximum allowable internal working pressure, maximum allowable external working pressure, and cryogenic temperature are discussed. The allowable stress criterion is determined based on the allowable stress philosophy of the ASME codes. The computed cryogenic heat load of the magnets is compared with the allowable cryogenic consumption budget. The presented cool-down time of the magnets was studied under the conditions of a limited supply rate and a controlled temperature differential of 50 K in the magnets.

P. Brindza, E. Sun, S. Lassiter, M. Fowler

2010-04-01T23:59:59.000Z

284

Temperature dependence of the resonance and low-energy spin excitations in superconducting FeTe0.6Se0.4  

SciTech Connect (OSTI)

We use inelastic neutron scattering to study the temperature dependence of the low-energy spin excitations in single crystals of superconducting FeTe{sub 0.6}Se{sub 0.4} (T{sub c} = 14 K). In the low-temperature superconducting state, the imaginary part of the dynamic susceptibility at the electron and hole Fermi-surfaces nesting wave vector Q = (0.5, 0.5), {chi}{sup ''} (Q, {omega}), has a small spin gap, a two-dimensional neutron spin resonance above the spin gap, and increases linearly with increasing {h_bar}{omega} for energies above the resonance. While the intensity of the resonance decreases like an order parameter with increasing temperature and disappears at temperature slightly above T{sub c}, the energy of the mode is weakly temperature dependent and vanishes concurrently above T{sub c}. This suggests that in spite of its similarities with the resonance in electron-doped superconducting BaFe{sub 2-x} (Co, Ni){sub x}As{sub 2}, the mode in FeTe{sub 0.6}Se{sub 0.4} is not directly associated with the superconducting electronic gap.

Lipscombe, O. J. [University of Tennessee, Knoxville (UTK); Luo, H.Q. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics; Lumsden, Mark D [ORNL; Dai, Pengcheng [University of Tennessee, Knoxville (UTK)

2012-01-01T23:59:59.000Z

285

E-Print Network 3.0 - anisotropic superconducting properties...  

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

in the Superconductivity Group Background|: i) Experiments... in high-magnetic-fields: Members of the superconductivity group in Durham have published arguably the most......

286

Secrets of superconductivity revealed  

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

material Cerium-Colbalt-Indium5 reveals new secrets about how superconductivity and magnetism can be related. January 3, 2014 Simon Gerber, first author of the publication on the...

287

Operation experiences with a 30 kV/100 MVA high temperature superconducting cable system  

Science Journals Connector (OSTI)

A superconducting cable based on Bi-2223 tape technology has been developed, installed and operated in the public network of Copenhagen Energy in a two-year period between May 2001 and May 2003. This paper gives a brief overview of the system and analyses some of the operation experiences. The aim of this demonstration project is to gain experience with HTS cables under realistic conditions in a live distribution network. Approximately 50?000 utility customers have their electric power supplied through the HTS cable. The cable system has delivered 226 GW h of energy and reached a maximum operating current of 1157 A. The operation experiences include over-currents of 6 kA due to faults on peripheral lines, commissioning, servicing and failure responses on the cooling system, continuous 24 h, 7 day per week monitoring and performance of the alarm system. The implications of these experiences for the future applications of HTS cable systems are analysed.

Ole Tønnesen; Manfred Däumling; Kim H Jensen; Svend Kvorning; Søren K Olsen; Chresten Træholt; Erling Veje; Dag Willén; Jacob Østergaard

2004-01-01T23:59:59.000Z

288

Magnetic field dependence of the proximity induced triplet superconductivity at ferromagnet/superconductor interfaces  

E-Print Network [OSTI]

of long-range spin-polarized supercurrents in S-F-S Josephson junctions, signifying the appearance of a proximity- induced spin-triplet pairing order in F. It is well known that ferromagnetism and spin- singlet superconductivity are two inimical orders... the past decade experiments on S-F-S Josephson junctions with the half metallic ferromagnet (HMF) (CrO2),3-5 intermetallic (Cu2MnAl),6 and metallic (Co)7,8 barriers have revealed evidence of supercurrents in F barriers much thicker than F? . Equal...

Kalcheim, Yoav; Felner, Israel; Millo, Oded; Kirzhner, Tal; Koren, Gad; Di Bernardo, Angelo; Egilmez, Mehmet; Blamire, Mark G.; Robinson, Jason W. A.

2014-05-21T23:59:59.000Z

289

Operating principle of a high Tc superconducting saturable magnetic core fault current limiter  

Science Journals Connector (OSTI)

An electrical fault current limiter (FCL) designed with a high Tc superconducting (HTS) dc bias winding is described. The winding is prepared by using a Ag-clad (Bi,Pb)2Sr2Ca2Cu3O10+x HTS wire. The limiting behaviour of this FCL is investigated and considered with respect to operation in a 6 kV power system. The results show that the FCL limits fault currents effectively, and is a possible solution for reducing power system fault currents.

J.X. Jin; S.X. Dou; C. Grantham; D. Sutanto; H.K. Liu

1997-01-01T23:59:59.000Z

290

Strong enhancement of superconductivity in a nanosized Pb bridge  

Science Journals Connector (OSTI)

In recent experiments with a superconducting nanosized Pb bridge formed between a scanning tunneling microscope tip and a substrate, superconductivity has been detected at magnetic fields, that are a few times larger than the third (surface) critical field. We describe the observed phenomenon on the basis of a numerical solution of the Ginzburg-Landau equations in a model structure consisting of six conoids. The spatial distribution of the superconducting phase is shown to be strongly inhomogeneous, with a concentration of the superconducting phase near the narrowest part (the “neck”) of the bridge. We show that suppression of superconductivity in the bridge by applied magnetic field or by temperature first occurs near the bases and then in the neck region, what leads to a continuous superconducting-to-normal resistive transition. A position of the transition midpoint depends on temperature and, typically, is by one order of magnitude higher than the second critical field Hc2. We find that the vortex states can be realized in the bridge at low temperatures T/Tcbridge that are characterized by a varying vorticity as a function of the bridge’s height.

V.R. Misko; V.M. Fomin; J.T. Devreese

2001-06-15T23:59:59.000Z

291

Magnetism and superconductivi[t]y in Pr-based filled skutterudite arsenides  

E-Print Network [OSTI]

5.11: Zero ?eld electrical resistivity vs temperature ?(T )technique. The electrical resistivity ? vs temperature T5.3: The zero-?eld electrical resistivity ? vs temperature T

Sayles, Todd Allen

2008-01-01T23:59:59.000Z

292

Critical current measurements on a Ag/Bi-Pb-Sr-Ca-Cu-O composite coil as a function of temperature and external magnetic field  

SciTech Connect (OSTI)

Transport critical currents have been measured on two coils of high-temperature superconducting (HTSC) tape as a function of temperature and external magnetic field. The HTSC tape and the coils were fabricated by American Superconductor Corporation. The sample coil windings have inside and outside diameters of roughly 25 mm and 40 mm, respectively, and a length of 50 mm. They contain about 300 turns of filamentary Bi-Pb-Sr-Ca-Cu-O 2223 HTSC material sheathed in Ag to form a 0. 18-mm by 2.54-mm tape, with a total length of about 30 m. Critical current results are reported for temperatures between 4.2 K and 90 K, in magnetic fields ranging up to 5.5 T.

Schwenterly, S.W.; Lue, J.W.; Lubell, M.S.; Luton, J.N. [Oak Ridge National Lab., TN (United States); Joshi, C.H. [American Superconductor Corp., Watertown, MA (United States)

1992-10-01T23:59:59.000Z

293

Critical current measurements on a Ag/Bi-Pb-Sr-Ca-Cu-O composite coil as a function of temperature and external magnetic field  

SciTech Connect (OSTI)

Transport critical currents have been measured on two coils of high-temperature superconducting (HTSC) tape as a function of temperature and external magnetic field. The HTSC tape and the coils were fabricated by American Superconductor Corporation. The sample coil windings have inside and outside diameters of roughly 25 mm and 40 mm, respectively, and a length of 50 mm. They contain about 300 turns of filamentary Bi-Pb-Sr-Ca-Cu-O 2223 HTSC material sheathed in Ag to form a 0. 18-mm by 2.54-mm tape, with a total length of about 30 m. Critical current results are reported for temperatures between 4.2 K and 90 K, in magnetic fields ranging up to 5.5 T.

Schwenterly, S.W.; Lue, J.W.; Lubell, M.S.; Luton, J.N. (Oak Ridge National Lab., TN (United States)); Joshi, C.H. (American Superconductor Corp., Watertown, MA (United States))

1992-01-01T23:59:59.000Z

294

Model for local para-Cooperons possibly relevant for high-temperature superconductors  

SciTech Connect (OSTI)

We examine the superconductivity analog of the local paramagnon concept in itinerant magnetism. This local-pairing model involves critical temperatures which are /ital not/ exponential, in contrast with the usual BCS ones. Interesting consequences are expected, in particular concerning the possibility of reaching high superconducting temperatures.

Beal-Monod, M. T.

1989-06-01T23:59:59.000Z

295

Mixed-mu superconducting bearings  

DOE Patents [OSTI]

A mixed-mu superconducting bearing is disclosed including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure. 9 figs.

Hull, J.R.; Mulcahy, T.M.

1998-03-03T23:59:59.000Z

296

Primary beam steering due to field leakage from superconducting SHMS magnets  

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

Simulations of the magnetic fields from the Super High Momentum Spectrometer in Hall C at Thomas Jefferson National Accelerator Facility show significant field leakage into the region of the primary beam line between the target and the beam dump. Without mitigation, these remnant fields will steer the unscattered beam enough to limit beam operations at small scattering angles. Presented here are magnetic field simulations of the spectrometer magnets and a solution using optimal placement of a minimal amount of shielding iron around the beam line.

Moore, M.H.; Waidyawansa, B.P.; Covrig, S.; Carlini, R.; Benesch, J.

2014-11-01T23:59:59.000Z

297

Primary Beam Steering Due to Field Leakage from Superconducting SHMS Magnets  

E-Print Network [OSTI]

Simulations of the magnetic fields from the Super High Momentum Spectrometer in Hall C at Thomas Jefferson National Accelerator Facility show significant field leakage into the region of the primary beam line between the target and the beam dump. Without mitigation, these remnant fields will steer the unscattered beam enough to limit beam operations at small scattering angles. Presented here are magnetic field simulations of the spectrometer magnets and a solution using optimal placement of a minimal amount of shielding iron around the beam line.

Michael H. Moore; Buddhini P. Waidyawansa; Silviu Covrig; Roger Carlini; Jay Benesch

2014-06-30T23:59:59.000Z

298

A worldwide overview of superconductivity development efforts for utility applications  

SciTech Connect (OSTI)

The progress and prospects for the application of high temperature superconductivity to the electric power sector has been the topic of an IEA Implementing Agreement begun in 1990. The present task members are: Canada, Denmark, Finland, Germany, Israel, Italy, Japan, the Netherlands, Norway, Sweden, Switzerland, Turkey, the United Kingdom, and the United States. As a result of the Implementing Agreement, work has been performed by the Operating Agent with the full participation of all of the member countries. This work has facilitated the exchange of information among experts in all member countries and is the basis for much of the information contained in this paper. This paper summarizes progress toward application of high temperature superconductivity to devices for use in the electric power sector such as: fault-current limiters, cables, superconducting magnetic energy Storage, rotating machinery, transformers, and flywheels incorporating magnetic bearings. Such devices are being designed, built and tested throughout the world.

Giese, R.F.

1996-04-01T23:59:59.000Z

299

Magnetization curves for thin films of layered type-II superconductors, Kolmogorov-Arnold-Moser theory, and the devil's staircase  

SciTech Connect (OSTI)

Magnetization curves for a thin-layered superconducting film in parallel magnetic field have been shown to become devil's staircases provided the superconducting layers are perpendicular to the film plane. The transition from an incomplete to a complete devil's staircase with decreasing temperature is predicted. A chain of vortices is described by the generalized Frenkel-Kontorova model.

Burkov, S.E. (Laboratory of Atomic and Solid State Physics, Clark Hall, Cornell University, Ithaca, New York (USA) Landau Institute for Theoretical Physics, Moscow (U.S.S.R))

1991-08-01T23:59:59.000Z

300

Superconducting active impedance converter  

DOE Patents [OSTI]

A transimpedance amplifier for use with high temperature superconducting, other superconducting, and conventional semiconductors allows for appropriate signal amplification and impedance matching to processing electronics. The amplifier incorporates the superconducting flux flow transistor into a differential amplifier configuration which allows for operation over a wide temperature range, and is characterized by high gain, relatively low noise, and response times less than 200 picoseconds over at least a 10-80 K. temperature range. The invention is particularly useful when a signal derived from either far-IR focal plane detectors or from Josephson junctions is to be processed by higher signal/higher impedance electronics, such as conventional semiconductor technology. 12 figures.

Ginley, D.S.; Hietala, V.M.; Martens, J.S.

1993-11-16T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Superconducting active impedance converter  

DOE Patents [OSTI]

A transimpedance amplifier for use with high temperature superconducting, other superconducting, and conventional semiconductor allows for appropriate signal amplification and impedance matching to processing electronics. The amplifier incorporates the superconducting flux flow transistor into a differential amplifier configuration which allows for operation over a wide temperature range, and is characterized by high gain, relatively low noise, and response times less than 200 picoseconds over at least a 10-80 K. temperature range. The invention is particularly useful when a signal derived from either far-IR focal plane detectors or from Josephson junctions is to be processed by higher signal/higher impedance electronics, such as conventional semiconductor technology.

Ginley, David S. (Albuquerque, NM); Hietala, Vincent M. (Placitas, NM); Martens, Jon S. (Albuquerque, NM)

1993-01-01T23:59:59.000Z

302

Low-temperature magnetic characterization of optimum and etch-damaged in-plane magnetic tunnel junctions  

SciTech Connect (OSTI)

We describe low-temperature characterization of magnetic tunnel junctions (MTJs) patterned by reactive ion etching for spin-transfer-torque magnetic random access memory. Magnetotransport measurements of typical MTJs show increasing tunneling magnetoresistance (TMR) and larger coercive fields as temperature is decreased down to 10 K. However, MTJs selected from the high-resistance population of an MTJ array exhibit stable intermediate magnetic states when measured at low temperature and show TMR roll-off below 100 K. These non-ideal low-temperature behaviors arise from edge damage during the etch process and can have negative impacts on thermal stability of the MTJs.

Kan, Jimmy J.; Gottwald, Matthias; Fullerton, Eric E. [Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States)] [Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States); Lee, Kangho; Kang, Seung H. [Advanced Technology, Qualcomm, Inc., San Diego, California 92121 (United States)] [Advanced Technology, Qualcomm, Inc., San Diego, California 92121 (United States)

2013-09-21T23:59:59.000Z

303

Magnetic Imaging of Micrometer and Nanometer-size Magnetic Structures and Their Flux-Pinning Effects on Superconducting Thin Films  

E-Print Network [OSTI]

to various ferromagnetic structures. These magnetic structures include: (i) alternating iron-brass shims of 275 mu m period, (ii) an array of 4 mu m wide Co stripes with smaller period (9 mu m), (iii) a square array of 50nm diameter, high aspect ratio (5...

Ozmetin, Ali E.

2010-07-14T23:59:59.000Z

304

Superconductivity and Physical Properties of CaPd2Ge2 Single Crystals  

SciTech Connect (OSTI)

We present the superconducting and normal state properties of CaPd2Ge2 single crystals investigated by magnetic susceptibility ?, isothermal magnetization M, heat capacity Cp, in-plane electrical resistivity ? and London penetration depth ? versus temperature T and magnetic field H measurements. Bulk superconductivity is inferred from the ?(T) and Cp(T) data. The ?(T) data exhibit metallic behavior and a superconducting transition with Tc onset = 1.98 K and zero resistivity at Tc 0 = 1.67 K. The ?(T) reveals the onset of superconductivity at 2.0 K. For T > 2.0 K, the ?(T) and M(H) are weakly anisotropic paramagnetic with ?ab > ?c. The Cp(T) data confirm the bulk superconductivity below Tc = 1.69(3) K. The superconducting state electronic heat capacity is analyzed within the framework of a single-band ?-model of BCS superconductivity and various normal and superconducting state parameters are estimated. Within the ?-model, the Cp(T) data and the ab plane ?(T) data consistently indicate a moderately anisotropic s-wave gap with ?(0)/kBTc ? 1.6, somewhat smaller than the BCS value of 1.764. The relationship of the heat capacity jump at Tc and the penetration depth measurement to the anisotropy in the s-wave gap is discussed.

Anand, V K [Ames Laboratory; Kim, Hyunsoo [Ames Laboratory; Tanatar, Makariy A [Ames Laboratory; Prozorov, Ruslan [Ames Laboratory; Johnston, David C [Ames Laboratory

2014-10-08T23:59:59.000Z

305

Calculating levitation forces in the magnet-high-temperature superconductor systems  

Science Journals Connector (OSTI)

A new method of calculation of the magnetic levitation force in the permanent magnet-high-temperature superconductor systems is proposed based on the Maxwell ... the gap width calculated for various regimes of superconductor

Yu. S. Ermolaev; I. A. Rudnev

2005-12-01T23:59:59.000Z

306

Development and Investigation of a Dipole Magnet with a High-Temperature Superconductor Winding  

Science Journals Connector (OSTI)

The structure of a dipole magnet with an iron yoke, where the winding is made of a Bi-2223 high-temperature superconductor, has been developed and the magnet has been built at the Institute of High-Energy Physics...

A. I. Ageev; I. V. Bogdanov; V. V. Zubko; S. S. Kozub; K. P. Myznikov…

2002-12-01T23:59:59.000Z

307

Penetration of ac magnetic field into bulk high-temperature superconductors: Experiment and simulation  

E-Print Network [OSTI]

Penetration of ac magnetic field into bulk high-temperature superconductors: Experiment from these models for high-temperature superconductors are observed at the op- eration in ac fields condi- tions is very important for correct modeling magnetic prop- erties of high-temperature

Paperno, Eugene

308

High-temperature superconductivity in a family of iron pnictide materials  

E-Print Network [OSTI]

crystals forming from Na+ and Cl? ion in brine solutions). A finishing temperature is chosen such that the flux will still be liquid, and the ampoule is removed from the furnace 13 3. Metallic Flux Growth Figure 3.1: The phase diagram for a mixture of Iron... had several accidents involving explosions of quartz tubes at high temperatures. These are very dangerous and risk toxic contamination of the furnace and surrounding areas. Consequently, both of our furnaces were always run in a sealed and negative...

Gillett, Jack

2011-11-08T23:59:59.000Z

309

Weak magnetic field effects on chiral critical temperature in a nonlocal Nambu--Jona-Lasinio model  

E-Print Network [OSTI]

In this article we study the nonlocal Nambu--Jona-Lasinio model with a Gaussian regulator in the chiral limit. Finite temperature effects and the presence of a homogeneous magnetic field are considered. The magnetic evolution of the critical temperature for chiral symmetry restoration is then obtained. Here we restrict ourselves to the case of low magnetic field values, being this a complementary discussion to the exisiting analysis in nonlocal models in the strong magnetic field regime.

Loewe, M; Villavicencio, C; Zamora, R

2014-01-01T23:59:59.000Z

310

Weak magnetic field effects on chiral critical temperature in a nonlocal Nambu--Jona-Lasinio model  

E-Print Network [OSTI]

In this article we study the nonlocal Nambu--Jona-Lasinio model with a Gaussian regulator in the chiral limit. Finite temperature effects and the presence of a homogeneous magnetic field are considered. The magnetic evolution of the critical temperature for chiral symmetry restoration is then obtained. Here we restrict ourselves to the case of low magnetic field values, being this a complementary discussion to the exisiting analysis in nonlocal models in the strong magnetic field regime.

M. Loewe; F. Marquez; C. Villavicencio; R. Zamora

2014-10-27T23:59:59.000Z

311

The NHMFL is developing two Series-Connected Hybrid (SCH) magnets, each comprising a superconducting outsert  

E-Print Network [OSTI]

for neutron scattering experiments. Development and fabrication of this Conical Bore Resistive Insert has scattering experiments are expected by the end of 2014. Neutron Scattering at 25 Teslas: MagLab Completes technology developed at the NHMFL. The complete HZB SCH Magnet system commissioning and early neutron

McQuade, D. Tyler

312

Measurements of electromagnetic properties of LCT (Large Coil Task) coils in IFSMTF (International Fusion Superconducting Magnet Test Facility)  

SciTech Connect (OSTI)

Participants in the international Large Coil Task (LCT) have designed, built, and tested six different toroidal field coils. Each coil has a 2.5- by 3.5-m, D-shaped bore and a current between 10 and 18 kA and is designed to demonstrate stable operation at 8 T, with a superimposed averaged pulsed field of 0.14 T in 1.0 s and simulated nuclear heating. Testing of the full six-coil toroidal array began early in 1986 and was successfully completed on September 3, 1987, in the International Fusion Superconducting Magnet Test Facility (IFSMTF) at Oak Ridge National Laboratory (ORNL). This paper summarizes electromagnetic properties of LCT coils measured in different modes of energization and fast dump. Effects of mutual coupling and induced eddy currents are analyzed and discussed. Measurements of the ac loss caused by the superimposed pulsed fields are summarized. Finally, the interpretation of the test results and their relevance to practical fusion are presented. 11 refs., 10 figs., 4 tab.

Shen, S.S.; Baylor, L.R.; Dresner, L.; Fehling, D.T.; Lubell, M.S.; Lue, J.W.; Luton, J.N.; McManamy, T.J.; Wilson, C.T.; Wintenberg, R.E.

1987-01-01T23:59:59.000Z

313

Cryogenic permanent magnet undulators  

Science Journals Connector (OSTI)

In order to obtain high magnetic fields in a short period undulator, superconductive undulators have been actively investigated in recent years. In this paper, however, we propose a new approach, the cryogenic permanent magnet undulator (CPMU) design, using permanent magnets at the cryogenic temperature of liquid nitrogen or higher. This cryogenic scheme can be easily adapted to currently existing in-vacuum undulators and it improves the magnetic field performance by 30%–50%. Unlike superconductive undulators operating around the liquid helium temperature, there is no big technological difficulty such as the thermal budget problem. In addition, existing field correction techniques are applicable to the CPMUs. Since there is no quench in the CPMUs, the operation of the CPMUs has the same reliability as conventional permanent magnet undulators.

Toru Hara; Takashi Tanaka; Hideo Kitamura; Teruhiko Bizen; Xavier Maréchal; Takamitsu Seike; Tsutomu Kohda; Yutaka Matsuura

2004-05-18T23:59:59.000Z

314

Towards measuring variations of Casimir energy by a superconducting cavity  

E-Print Network [OSTI]

We consider a Casimir cavity, one plate of which is a thin superconducting film. We show that when the cavity is cooled below the critical temperature for the onset of superconductivity, the sharp variation (in the far infrared) of the reflection coefficient of the film engenders a variation in the value of the Casimir energy. Even though the relative variation in the Casimir energy is very small, its magnitude can be comparable to the condensation energy of the superconducting film, and this gives rise to a number of testable effects, including a significant increase in the value of the critical magnetic field, required to destroy the superconductivity of the film. The theoretical ground is therefore prepared for the first experiment ever aimed at measuring variations of the Casimir energy itself.

Giuseppe Bimonte; Enrico Calloni; Giampiero Esposito; Leopoldo Milano; Luigi Rosa

2005-04-07T23:59:59.000Z

315

MICROSTRUCTURE OF SUPERCONDUCTING MGB(2).  

SciTech Connect (OSTI)

Recently, Akimitsu and co-workers [1] discovered superconductivity at 39 K in the intermetallic compound MgB{sub 2}. This discovery provides a new perspective on the mechanism for superconductivity. More specifically, it opens up possibilities for investigation of structure/properties in a new class of materials. With the exceptions of the cuprate and C{sub 60} families of compounds, MgB{sub 2} possesses the highest superconducting transition temperature T{sub c}. Its superconductivity appears to follow the BCS theory, apparently being mediated by electron-phonon coupling. The coherence length of MgB{sub 2} is reported to be longer than that of the cuprates [2]. In contrast to the cuprates, grain boundaries are strongly coupled and current density is determined by flux pinning [2,3]. Presently, samples of MgB{sub 2} commonly display inhomogeneity and porosity on the nanoscale, and are untextured. In spite of these obstacles, magnetization and transport measurements show that polycrystalline samples may carry large current densities circulating across many grains [3,4]. Very high values of critical current densities and critical fields have been recently observed in thin films [5,6]. These attributes suggest possible large scale and electronic applications. The underlying microstructure can be intriguing, both in terms of basic science and in applied areas. Subsequent to the discovery, many papers were published [1-13], most dealing with synthesis, physical properties, and theory. There have yet been few studies of microstructure and structural defects [11, 14]. A thorough understanding of practical superconducting properties can only be developed after an understanding of microstructure is gained. In this work we review transmission electron microscopy (TEM) studies of sintered MgB{sub 2} pellets [14]. Structural defects, including second phase particles, dislocations, stacking faults, and grain boundaries, are analyzed using electron diffraction, electron-energy loss spectroscopy (EELS), high resolution imaging, and structural modeling.

ZHU,Y.; LI,Q.; WU,L.; VOLKOV,V.; GU,G.; MOODENBAUGH,A.R.

2001-07-12T23:59:59.000Z

316

Proposal for the award of a contract for the supply of electronics for the temperature control of cavity windows and helium gas return lines for the superconducting cavities of the LEP200 radio frequency system  

E-Print Network [OSTI]

Proposal for the award of a contract for the supply of electronics for the temperature control of cavity windows and helium gas return lines for the superconducting cavities of the LEP200 radio frequency system

1991-01-01T23:59:59.000Z

317

First-cut design of an all-superconducting 100-T direct current magnet  

SciTech Connect (OSTI)

A 100-T magnetic field has heretofore been available only in pulse mode. This first-cut design demonstrates that a 100-T DC magnet (100?T) is possible. We base our design on: Gadolinium-based coated superconductor; a nested-coil formation, each a stack of double-pancake coils with the no-insulation technique; a band of high-strength steel over each coil; and a 12-T radial-field limit. The 100?T, a 20?mm cold bore, 6-m diameter, 17-m height, with a total of 12?500-km long superconductor, stores an energy of 122 GJ at its 4.2-K operating current of 2400?A. It requires a 4.2-K cooling power of 300?W.

Iwasa, Yukikazu, E-mail: iwasa@jokaku.mit.edu; Hahn, Seungyong [Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, Massachusetts 02139 (United States)] [Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, Massachusetts 02139 (United States)

2013-12-16T23:59:59.000Z

318

Progress in Superconducting Metamaterials  

E-Print Network [OSTI]

We review progress in the development and applications of superconducting metamaterials. The review is organized in terms of several distinct advantages and unique properties brought to the metamaterials field by superconductivity. These include the low-loss nature of the meta-atoms, their compact structure, their extraordinary degree of nonlinearity and tunability, magnetic flux quantization and the Josephson effect, quantum effects in which photons interact with quantized energy levels in the meta-atom, as well as strong diamagnetism.

Philipp Jung; Alexey V. Ustinov; Steven M. Anlage

2014-03-25T23:59:59.000Z

319

Monitoring of thin layer deposits of high temperature superconducting materials by energy-dispersive X-ray fluorescence technique (EDXRF)  

Science Journals Connector (OSTI)

We present here a method for rapidly monitoring the composition of samples deposited on a substrate. This was applied to the case of superconducting material YBa2Cu3O7 deposited by laser evaporation on quartz pla...

Madan Lal; R K Choudhury

1988-05-01T23:59:59.000Z

320

Superconducting and Magnetic Behavior in La2-xNaxCuO4  

Science Journals Connector (OSTI)

...this fabric (25). High strain rates and fluctu-ating stresses characterize the base ofthe Greenland ice sheet at Camp Century and Dye 3, but temperatures are less than-13 C and a single-maximum fabric is de-veloped (16-18, 24, 26...

M. A. SUBRAMANIAN; J. GOPALAKRISHNAN; C. C. TORARDI; T. R. ASKEW; R. B. FLIPPEN; A. W. SLEIGHT; J. J. LIN; S. J. POON

1988-04-22T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Anisotropic magnetoresistance of single-crystal HoNi2B2C and the interplay of magnetic and superconducting order  

E-Print Network [OSTI]

The in-plane resistivity and magnetization measurements as a function of the magnitude and direction of the magnetic field and the temperature are reported for single-crystal samples of the HoNi2B2C magnetic superconductor. Features corresponding...

Rathnayaka, KDD; Naugle, Donald G.; Cho, BK; Canfield, PC.

1996-01-01T23:59:59.000Z

322

Competition between magnetism and superconductivity in TmNi{sub 2}B{sub 2}C observed by muon-spin rotation  

SciTech Connect (OSTI)

We report muon-spin-rotation measurements of the internal field in the rare-earth nickel boride carbide superconductor TmNi{sub 2}B{sub 2}C from 100 mK up to well above the superconducting transition temperature ({ital T}{sub {ital c}}=9.5 K). An oscillatory muon response indicates that the muon is affected by a quasistatic local field that follows a {ital T}{sup {minus}1} dependence over a wide temperature range and without interruption at the superconducting transition. The corresponding relaxation rate remains constant in the normal state, but begins to rise very sharply with decreasing temperature below {ital T}{sub {ital c}} scaling approximately with the local field down to its maximum at 2.5 K. The quasistatic internal field may be attributed to a spiral structure or slow three-dimensional correlations of the Tm moments. Decoupling experiments reveal a dynamic depolarization mechanism which may tentatively be ascribed to fast two-dimensional correlations of the Ni moments, slowed by the onset of superconductivity.

Cooke, D.W.; Smith, J.L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Blundell, S.J.; Chow, K.H.; Pattenden, P.A.; Pratt, F.L. [Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom)] [Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom); Cox, S.F.J.; Brown, S.R. [ISIS, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom)] [ISIS, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom); Morrobel-Sosa, A. [California Polytechnic State University, San Luis Obispo, California 93407 (United States)] [California Polytechnic State University, San Luis Obispo, California 93407 (United States); Lichti, R.L. [Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States)] [Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Gupta, L.C.; Nagarajan, R.; Hossain, Z. [Tata Institute of Fundamental Research, Homi Bhabha Road, Bombay 400 005 (India)] [Tata Institute of Fundamental Research, Homi Bhabha Road, Bombay 400 005 (India); Mazumdar, C. [Indian Institute of Technology, Powai, Bombay 400 076 (India)] [Indian Institute of Technology, Powai, Bombay 400 076 (India); Godart, C. [UPR-209, Centre National de la Recherche Scientifique, 92195 Meudon Cedex (France)] [UPR-209, Centre National de la Recherche Scientifique, 92195 Meudon Cedex (France)

1995-08-01T23:59:59.000Z

323

Temperature Difference Leads to Magnetism | Physical Review Focus Previous Story / Volume 28 archive  

E-Print Network [OSTI]

Temperature Difference Leads to Magnetism | Physical Review Focus Previous Story / Volume 28 Leads to Magnetism J. Wu/Univ. of California, Berkeley Heat field. Heating the right edge of an n a magnetic field pointing out of the screen, according to computer simulations. Computer simulations suggest

Wu, Junqiao

324

Superconductivity Highlights | Neutron Science | ORNL  

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

Superconductivity Superconductivity SHARE Superconductivity Highlights 1-6 of 6 Results Doug Scalapino discusses "common thread" linking unconventional superconducting materials December 01, 2012 - Douglas Scalapino was the inaugural speaker for a new joint lecture series sponsored by the Spallation Neutron Source and the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory. New VULCAN tests of Japanese cable for US ITER's central magnet system February 01, 2012 - Neutron testing of the Japanese-made superconducting cable for the central solenoid (CS) magnetic system for US ITER begins next Tuesday, says Ke An, lead instrument scientist for the VULCAN Engineering Materials Diffractometer at the Spallation Neutron Source. ARCS maps collaborative magnetic spin behavior in iron telluride

325

Mechanical Strength, Swelling and Weight Loss of Inorganic Fusion Magnet Insulation Systems Following Reactor Irradiation  

Science Journals Connector (OSTI)

Superconducting fusion magnets require a high electrical and mechanical ... were irradiated at ambient temperature in the TRIGA reactor (Vienna, Austria) up to neutron fluences...21, 1022 and 5x1022 m?2...(E>0.1 ...

K. Humer; P. Rosenkranz; H. W. Weber…

2000-01-01T23:59:59.000Z

326

Abstract--Temperature, current density and magnetic field distributions in YBCO bulk superconductor during a pulsed-field  

E-Print Network [OSTI]

-- bulk YBaCuO, stored magnetic energy, thermal coupling, magnetization, modelling. I. INTRODUCTION HE as cryo-permanent magnets [1], [2]. To magnetize the HTS, pulsed field magnetization (PFM) process1 Abstract-- Temperature, current density and magnetic field distributions in YBCO bulk

Paris-Sud XI, Université de

327

Study On Magnetic Shielding Type Superconducting Fault Current Limiter Using Bi-Sr-Ca-Cu-O Cylinder  

Science Journals Connector (OSTI)

The power application of a superconductor to restrain a fault current has been researched. A superconducting fault current limiter using a Bi-Sr-Ca-Cu-O cylinder has been developed. This limiter consists of the p...

Michiharu Ichikawa; Hiroyuki Kado; Kunikazu Izumi

1994-01-01T23:59:59.000Z

328

Cascaded multilevel converter based superconducting magnetic energy storage system for frequency control  

Science Journals Connector (OSTI)

Abstract The Super conducting magnetic energy storage (SMES), owing to high energy density and capacity, has been widely applied in different stages of power systems. One of these applications is the frequency control of the electric power systems. Frequency of a power system depends on the balance of produced and demanded energy in any instant of time. Subsequent to a sudden change in the system, which causes produced and demanded energy mismatch, frequency oscillates. According to standards, the permissible variation band of the frequency is very restricted. Larger swings of frequency may result in instability and undesirable trips. As a result, suitable frequency control mechanisms should be implemented in the system. SMES is well-suited for this application because of high energy density and fast response. SMES is attached to system by a power conditioning system (PCS) which include power electronic converters, mainly a dc–dc chopper and an inverter. This paper, studies the application of a cascaded H-bridge (CHB) multilevel converter for frequency control. As far as the authors' knowledge, such a study has not been done before. The design procedure of the converter is presented. Simulation results on a sample system are presented to verify the performance of the proposed PCS.

Mohammad Farhadi Kangarlu; Mohammad Reza Alizadeh Pahlavani

2014-01-01T23:59:59.000Z

329

Magnet strength fluctuations in the SSC (Superconducting Super Collider) lattice: Part 2, Frequency modulation  

SciTech Connect (OSTI)

This is a continuation of SSC-N-305. SSC-N-305 examined the effects of field strength modulation, when the modulation frequency (f/sub mod/) was equal to zero (i.e., current offset). The objective of this study is to examine the effect of field strength modulation with modulation frequencies other than zero. To this end, the tracking routine TEAPOT is modified to simulate frequency modulation of the current output from the 10 main SSC magnet power supplies. The amplitude (A/sub i/) and phase (phi/sub i/) of the modulation for the i/sup th/ power supply are chosen randomly. Effects of bore tube shielding are included only when studying 60 Hz modulation frequency. Bore tube shielding is due to the copper coating on the bore tube walls. This coating modifies the amplitude and phase of the modulation inside the bore tube. The bore tube is more effective at shielding the dipole field and it becomes most effective as the modulation frequency increases. 3 refs., 10 figs., 3 tabs.

Goderre, G.P.

1987-06-01T23:59:59.000Z

330

Power superconducting power transmission cable  

DOE Patents [OSTI]

The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

Ashworth, Stephen P. (Cambridge, GB)

2003-01-01T23:59:59.000Z

331

Graphite and its Hidden Superconductivity | Stanford Synchrotron Radiation  

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

Graphite and its Hidden Superconductivity Graphite and its Hidden Superconductivity Wednesday, November 20, 2013 - 2:00pm SLAC, Conference Room 137-322 Pablo Esquinazi, University of Leipzig We review different experimental results that indicate the existence of granular superconductivity at high temperatures at graphite interfaces. In particular we will discuss the following experimental results: The temperature and magnetic field dependence of the electrical resistance of bulk and thin graphite samples and its relation with the existence of two-dimensional (2D) interfaces. The anomalous hysteresis in the magnetoresistance observed in graphite thin samples as well as its enhancement restricting the current path within the sample. The Josephson behavior of the current-voltage characteristics with

332

QCD at non-zero temperature and magnetic field  

E-Print Network [OSTI]

A status of lattice QCD thermodynamics, as of 2013, is summarized. Only bulk thermodynamics is considered. There is a separate section on magnetic fields.

Kalman Szabo

2014-01-16T23:59:59.000Z

333

Superconducting thermoelectric generator  

DOE Patents [OSTI]

An apparatus and method for producing electricity from heat. The present invention is a thermoelectric generator that uses materials with substantially no electrical resistance, often called superconductors, to efficiently convert heat into electrical energy without resistive losses. Preferably, an array of superconducting elements is encased within a second material with a high thermal conductivity. The second material is preferably a semiconductor. Alternatively, the superconducting material can be doped on a base semiconducting material, or the superconducting material and the semiconducting material can exist as alternating, interleaved layers of waferlike materials. A temperature gradient imposed across the boundary of the two materials establishes an electrical potential related to the magnitude of the temperature gradient. The superconducting material carries the resulting electrical current at zero resistivity, thereby eliminating resistive losses. The elimination of resistive losses significantly increases the conversion efficiency of the thermoelectric device.

Metzger, J.D.; El-Genk, M.S.

1996-01-01T23:59:59.000Z

334

Superconducting thermoelectric generator  

DOE Patents [OSTI]

An apparatus and method for producing electricity from heat. The present invention is a thermoelectric generator that uses materials with substantially no electrical resistance, often called superconductors, to efficiently convert heat into electrical energy without resistive losses. Preferably, an array of superconducting elements is encased within a second material with a high thermal conductivity. The second material is preferably a semiconductor. Alternatively, the superconducting material can be doped on a base semiconducting material, or the superconducting material and the semiconducting material can exist as alternating, interleaved layers of waferlike materials. A temperature gradient imposed across the boundary of the two materials establishes an electrical potential related to the magnitude of the temperature gradient. The superconducting material carries the resulting electrical current at zero resistivity, thereby eliminating resistive losses. The elimination of resistive losses significantly increases the conversion efficiency of the thermoelectric device.

Metzger, John D. (Eaton's Neck, NY); El-Genk, Mohamed S. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

335

Superconducting thermoelectric generator  

DOE Patents [OSTI]

An apparatus and method for producing electricity from heat is disclosed. The present invention is a thermoelectric generator that uses materials with substantially no electrical resistance, often called superconductors, to efficiently convert heat into electrical energy without resistive losses. Preferably, an array of superconducting elements is encased within a second material with a high thermal conductivity. The second material is preferably a semiconductor. Alternatively, the superconducting material can be doped on a base semiconducting material, or the superconducting material and the semiconducting material can exist as alternating, interleaved layers of waferlike materials. A temperature gradient imposed across the boundary of the two materials establishes an electrical potential related to the magnitude of the temperature gradient. The superconducting material carries the resulting electrical current at zero resistivity, thereby eliminating resistive losses. The elimination of resistive losses significantly increases the conversion efficiency of the thermoelectric device. 4 figs.

Metzger, J.D.; El-Genk, M.S.

1998-05-05T23:59:59.000Z

336

Alexei Abrikosov and Superconductivity  

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

Alexei Abrikosov and Superconductivity Alexei Abrikosov and Superconductivity Resources with Additional Information · Publications at ANL Alexei A. Abrikosov of the U.S. Department of Energy's Argonne National Laboratory (ANL) is a recipient of the 2003 Nobel Prize in Physics for his research in the area of superconductivity. Alexei Abrikosov Courtesy Argonne National Laboratory "Abrikosov's research [at ANL] centers on condensed-matter physics (the structure and behavior of solids and liquids), and concentrates on superconductivity, the ability of some materials to carry electrical current without resistance. He was the first to propose the concept of "type-II superconductors" in 1952 and constructed the theory of their magnetic properties, known as the Abrikosov vortex lattice.

337

Large Cryogenic Infrastructure for LHC Superconducting Magnet and Cryogenic Component Tests: Layout, Commissioning and Operational Experience  

SciTech Connect (OSTI)

The largest cryogenic test facility at CERN, located at Zone 18, is used to validate and to test all main components working at cryogenic temperature in the LHC (Large Hadron Collider) before final installation in the machine tunnel. In total about 1300 main dipoles, 400 main quadrupoles, 5 RF-modules, eight 1.8 K refrigeration units will be tested in the coming years.The test facility has been improved and upgraded over the last few years and the first 18 kW refrigerator for the LHC machine has been added to boost the cryogenic capacity for the area via a 25,000 liter liquid helium dewar. The existing 6 kW refrigerator, used for the LHC Test String experiments, will also be employed to commission LHC cryogenic components.We report on the design and layout of the test facility as well as the commissioning and the first 10,000 hours operational experience of the test facility and the 18 kW LHC refrigerator.

Calzas, C.; Chanat, D.; Knoops, S.; Sanmarti, M.; Serio, L. [Accelerator Technology Division, CERN, 1211 Geneva 23 (Switzerland)

2004-06-23T23:59:59.000Z

338

Critical State of Superconducting Solenoids  

Science Journals Connector (OSTI)

The critical state is a term introduced by Bean [1] to describe the magnetic properties of a bulk type II superconductor. In this state every region of the superconducting material carries the maximum induced cri...

M. S. Lubell

1966-01-01T23:59:59.000Z

339

Regeneration tests of a room temperature magnetic refrigerator and heat pump  

E-Print Network [OSTI]

A magnetic heat pump apparatus consisting of a solid magnetic refrigerant, gadolinium, and a liquid regenerator column of ethanol and water has been tested. Utilizing a 7T field, it produced a maximum temperature span of 80 K, and in separate tests, a lowest temperature of 241 K and a highest temperature of 328 K. Thermocouples, placed at intervals along the regenerator tube, permitted measurement of the temperature distribution in the regenerator fluid. No attempt was made to extract refrigeration from the device, but analysis of the temperature distributions shows that 34 watts of refrigeration was produced.

Brown, G V

2014-01-01T23:59:59.000Z

340

Quasi-one-dimensional magnetism in TiOCl and a theory of a lightly doped dimerized insulator  

E-Print Network [OSTI]

Transition metal oxides with low dimensional geometry have displayed fascinating new phenomena such as high temperature superconductivity and unconventional magnetism. The first part of this thesis is related to this rich ...

Seidel, Alexander, 1975-

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Magnetic Susceptibility Measurements at Ultra-low Temperatures  

Science Journals Connector (OSTI)

We report the design and operation of a device for ac magnetic susceptibility measurements that can operate down to 1 mK. The device, a modification of the standard mutual inductance bridge, is designed with d...

L. Yin; J. S. Xia; N. S. Sullivan; V. S. Zapf…

2010-02-01T23:59:59.000Z

342

Anisotropic superconductivity and vortex dynamics in magnetially coupled F/S and F/S/F hybrids.  

SciTech Connect (OSTI)

Magnetically coupled superconductor-ferromagnet hybrids offer advanced routes for nanoscale control of superconductivity. Magnetotransport characteristics and scanning tunneling microscopy images of vortex structures in superconductor-ferromagnet hybrids reveal rich superconducting phase diagrams. Focusing on a particular combination of a ferromagnet with a well-ordered periodic magnetic domain structure with alternating out-of-plane component of magnetization, and a small coherence length superconductor, we find directed nucleation of superconductivity above the domain wall boundaries. We show that near the superconductor-normal state phase boundary the superconductivity is localized in narrow mesoscopic channels. In order to explore the Abrikosov flux line ordering in F/S hybrids, we use a combination of scanning tunneling microscopy and Ginzburg-Landau simulations. The magnetic stripe domain structure induces periodic local magnetic induction in the superconductor, creating a series of pinning-anti-pinning channels for externally added magnetic flux quanta. Such laterally confined Abrikosov vortices form quasi-1D arrays (chains). The transitions between multichain states occur through propagation of kinks at the intermediate fields. At high fields we show that the system becomes nonlinear due to a change in both the number of vortices and the confining potential. In F/S/F hybrids we demonstrate the evolution of the anisotropic conductivity in the superconductor that is magnetically coupled with two adjacent ferromagnetic layers. Stripe magnetic domain structures in both F-layers are aligned under each other, resulting in a directional superconducting order parameter in the superconducting layer. The conductance anisotropy strongly depends on the period of the magnetic domains and the strength of the local magnetization. The anisotropic conductivity of up to three orders of magnitude can be achieved with a spatial critical temperature modulation of 5% of T{sub c}. Induced anisotropic properties in the F/S and F/S/F hybrids have a potential for future application in switching and nonvolatile memory elements operating at low temperatures.

Karapetrov, G.; Belkin, A.; Iavarone, M.; Fedor, J.; Novosad, V.; Milosevic, M. V.; Peeters, F. M. (Materials Science Division); (Illinois Inst. of Tech.); (Temple Univ.); (Slovak Academy of Sciences); (Univ. Antwerpen)

2011-01-01T23:59:59.000Z

343

Superconducting materials for large scale applications  

SciTech Connect (OSTI)

Significant improvements in the properties ofsuperconducting materials have occurred recently. These improvements arebeing incorporated into the latest generation of wires, cables, and tapesthat are being used in a broad range of prototype devices. These devicesinclude new, high field accelerator and NMR magnets, magnets for fusionpower experiments, motors, generators, and power transmission lines.These prototype magnets are joining a wide array of existing applicationsthat utilize the unique capabilities of superconducting magnets:accelerators such as the Large Hadron Collider, fusion experiments suchas ITER, 930 MHz NMR, and 4 Tesla MRI. In addition, promising newmaterials such as MgB2 have been discovered and are being studied inorder to assess their potential for new applications. In this paper, wewill review the key developments that are leading to these newapplications for superconducting materials. In some cases, the key factoris improved understanding or development of materials with significantlyimproved properties. An example of the former is the development of Nb3Snfor use in high field magnets for accelerators. In other cases, thedevelopment is being driven by the application. The aggressive effort todevelop HTS tapes is being driven primarily by the need for materialsthat can operate at temperatures of 50 K and higher. The implications ofthese two drivers for further developments will be discussed. Finally, wewill discuss the areas where further improvements are needed in order fornew applications to be realized.

Scanlan, Ronald M.; Malozemoff, Alexis P.; Larbalestier, David C.

2004-05-06T23:59:59.000Z

344

Superconductivity of Zirconium Alloys  

Science Journals Connector (OSTI)

The superconducting transition temperatures of alloys between zirconium and VIIIth column elements are substantially higher than those of zirconium. The same is true for zirconium-gold alloys. This observation confirms a rule previously established about the height of transition temperatures.

B. T. Matthias and E. Corenzwit

1955-10-15T23:59:59.000Z

345

Review of the low-temperature magnetic properties of magnetite from a rock magnetic perspective  

Science Journals Connector (OSTI)

......is documented in magneto- resistance studies (e.g. Belov 1994...A., 1954. Magnetic and electric properties of magnetite at...A., 1950. Magnetic and electric properties of natural synchroton-radiation...Spalek, J., 1992. Elementary formulation of the Verwey......

A. R. Muxworthy; E. McClelland

2000-01-01T23:59:59.000Z

346

Physica E 40 (2007) 1224 Electron coherence at low temperatures: The role of magnetic impurities  

E-Print Network [OSTI]

new measurements of the phase coherence time in ultra-clean gold and silver wires and analyse, Kondo temperatures below 1 mK and extremely small magnetic-impurity concentration levels of less than 0

347

Compact magnetic energy storage module  

DOE Patents [OSTI]

A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module.

Prueitt, Melvin L. (Los Alamos, NM)

1994-01-01T23:59:59.000Z

348

Compact magnetic energy storage module  

DOE Patents [OSTI]

A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module. 4 figures.

Prueitt, M.L.

1994-12-20T23:59:59.000Z

349

Optimization of operating temperature in cryocooled HTS magnets for compactness and efficiency  

E-Print Network [OSTI]

superconductor (HTS) magnets is presented, aiming simultaneously at small size and low energy consumption. The magnet systems considered here are refrigerated by a closed-cycle cryocooler, and liquid cryogens may. The excessive energy consumption or the degraded overall efficiency caused by a low temperature operation could

Chang, Ho-Myung

350

Hasty switch for space magnet  

Science Journals Connector (OSTI)

... AMS is the brainchild of Nobel-prizewinning physicist Samuel Ting of the Massachusetts Institute of Technology in Cambridge (Nature 455, 854–857; 2008). Such cosmic rays might be ... July shuttle flight and is instead likely to take off in the autumn. The liquid-helium coolant required to keep the superconducting magnet at its operating temperature of 2 °C ...

Edwin Cartlidge

2010-04-28T23:59:59.000Z

351

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network [OSTI]

describes the general technology of SMES, and explains theIn each of these technologies, except SMES, the electricalva lue of SMES compared to other technologies l5 . The

Hassenzahl, W.

2011-01-01T23:59:59.000Z

352

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network [OSTI]

angle for the SCR firing circuit. This in turn controls theare controlled by a firing circuit. (We describe here theVoltage pulses from the firing circuits cause the SCRs to

Hassenzahl, W.

2011-01-01T23:59:59.000Z

353

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network [OSTI]

hydro, compressed air, and battery energy storage are allenergy storage sys tem s suc h as pumped hydro and compressed air.

Hassenzahl, W.

2011-01-01T23:59:59.000Z

354

Temperature Dependence of Nuclear Magnetic Resonance of Fe57 in Magnetite  

Science Journals Connector (OSTI)

A report is made of an attempt to fit the temperature dependence of the observed nuclear magnetic resonance (NMR) frequencies for the two sublattices in magnetite to the measured temperature dependence of the magnetization. It is shown that when the microwave geff values as reported in the literature are used in this calculation, no fit between the NMR experiment and the moment measurement is obtained. If a geff=2 is assumed, however, the data may be brought into good agreement.

E. L. Boyd

1963-03-01T23:59:59.000Z

355

Potential impact of high temperature superconductors on maglev transportation  

SciTech Connect (OSTI)

This report describes the potential impact that high-temperature superconductors (HTSs) may have on transportation by magnetically levitated vehicles. It is not intended as a planning document, but rather as an overview of potential HTS applications to magnetic-levitation (maglev) transportation. The present maglev program in the United States is summarized, and the present status of development of HTSs is described. Areas identified for possible impact on maglev technology are (1) liquid-nitrogen-cooled levitation magnets, (2) magnetic-field shielding of the passenger compartment, (3) superconducting magnetic energy storage for wayside power, (4) superconducting bearings for flywheel energy storage for wayside power, (5) downleads to continuously powered liquid-helium-cooled levitation magnets, and (6) liquid-hydrogen-cooled levitation magnets and linear motor propulsion windings. Major technical issues that remain to be resolved for the use of HTSs in maglev applications include thermal magnetic stability, mechanical properties, and critical current density at liquid-nitrogen temperatures.

Hull, J.R.

1992-02-01T23:59:59.000Z

356

Evaluation of permanent magnets for high temperature operations  

E-Print Network [OSTI]

250 276 300 25 60 0 Temperature ( C) Fig. B. Tractive Force per unit Volume of Ni Cylinder vs. Temperature for barium ferrite. 'I. 2 1. 'I 'I. O O. e 0. 6 0. 7 Unannaallad ~ m g 0. 4 0. 6 OA 0. 3 0. 2 0. 1 0. 0 Cooling A noalls 24... 425 4% 0 75 '100125150175200225250275 0 Temperature ( C) 0 20 a 30 + 10 x 40 v SO Fig. lla. Tractive Force per unit Volume of Ni Cylinder vs. Temperature for Alnico 8, annealled from 0 to 50 hours in 10 hour steps. M E u m m 0 &i 'o 0 8 u...

Van Hees, Elizabeth

2012-06-07T23:59:59.000Z

357

High Temperature Superconductor Cable Concepts for Fusion Magnets.  

E-Print Network [OSTI]

??Three concepts of high temperature superconductor cables carrying kA currents (RACC, CORC and TSTC) are investigated, optimized and evaluated in the scope of their applicability… (more)

Barth, Christian

2013-01-01T23:59:59.000Z

358

MAGNET/CRYOCOOLER INTEGRATIONFOR THERMAL STABILITY IN CONDUCTION-COOLED SYSTEMS  

E-Print Network [OSTI]

MAGNET/CRYOCOOLER INTEGRATIONFOR THERMAL STABILITY IN CONDUCTION-COOLED SYSTEMS H.-M. Chang and K The stability conditions that take into accounts the size of superconducting magnets and the refrigeration the refrigeration, causing a rise in the temperature of the magnet winding and leading to burnout. It is shown

Chang, Ho-Myung

359

Negative Absolute Temperatures: "Hot" Spins in Spontaneous Magnetic Order  

Science Journals Connector (OSTI)

...neously applicable in solids at ultra-low scale the temperatures...be car-and ultiried out at ultra-low temperatures. ipole and...stages are cooled to Ti = 15 mK by the dilution \\L refrigerator...from Tf = 200 puK toward Tf = 15 mK. A new experimental sequence...

Pertti Hakonen; Olli V. Lounasmaa

1994-09-23T23:59:59.000Z

360

Changes Made on a 2.7-m Long Superconducting Solenoid Magnet Cryogenic System that allowed the Magnet to be kept Cold using 4 K Pulse Tube Cooler  

E-Print Network [OSTI]

in Cooler,” Advances in Cryogenic Engineering 57, pp 581 -Solenoid Magnet Cryogenic System that allowed the Magnet toof the International Cryogenic Engineering Conference 22,

Green, Michael

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Ferromagnetic clusters and superconducting order in La{sub 0.7}Ca{sub 0.3}MnO{sub 3}/YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} heterostructures  

SciTech Connect (OSTI)

The existence of magnetic and superconducting order in a [(La{sub 0.7}Ca{sub 0.3}MnO{sub 3}){sub 100{sub A}}/(YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}){sub 100A}]{sub 10} superlattice has been studied by polarized neutron reflectometry, SQUID magnetometry, and resistivity measurements. The magnetization line shapes observed by SQUID magnetometry under zero-field-cooled and field-cooled conditions imply an inhomogeneously disordered magnetic state of the manganite blocks. This is substantiated by resistivity measurements and polarized neutron reflectometry. Resistivity measurements under field-cooled conditions reveal strong perturbations, which imply that the ferromagnetic La{sub 0.7}Ca{sub 0.3}MnO{sub 3} blocks contain strong magnetic disorder with perturbations coupled to the magnetic order via charge hopping between domains. Polarized neutron reflectometry under zero-field-cooled conditions, below the superconducting transition, reveal a noncollinear ferromagnetic structure, coherent across half the superlattice blocks. Across the superconducting transition, the noncollinear components are perturbed by the superconducting order and attempt to align with the dominant ferromagnetic order. Additionally, the magnetic correlation length increases from half the superlattice structure to a magnetic structure correlated across the complete superlattice. At temperatures above the superconducting transition, the noncollinear magnetic components and the magnetic correlation length relax to the structure observed below the superconducting transition.

Deen, P. P. [Institut Laue-Langevin, 6 rue Jules Horowitz, Boite Postale 156, F-38042 Grenoble (France); European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, Boite Postale 220, F-38043 Grenoble (France); Yokaichiya, F. [Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973 (United States); De Santis, A.; Bobba, F.; Cucolo, A. M. [CNR/INFM Supermat Laboratory and Physics Department, University of Salerno, Via S. Allende, Baronissi 84081 (Italy); Wildes, A. R. [Institut Laue-Langevin, 6 rue Jules Horowitz, Boite Postale 156, F-38042 Grenoble (France)

2006-12-01T23:59:59.000Z

362

Superconductive articles including cerium oxide layer  

DOE Patents [OSTI]

A ceramic superconductor comprising a metal oxide substrate, a ceramic high temperature superconductive material, and a intermediate layer of a material having a cubic crystal structure, said layer situated between the substrate and the superconductive material is provided, and a structure for supporting a ceramic superconducting material is provided, said structure comprising a metal oxide substrate, and a layer situated over the surface of the substrate to substantially inhibit interdiffusion between the substrate and a ceramic superconducting material deposited upon said structure.

Wu, Xin D. (Greenbelt, MD); Muenchausen, Ross E. (Espanola, NM)

1993-01-01T23:59:59.000Z

363

Nature of the quantum spin correlations through the superconducting?normal phase transition in electron-doped superconducting Pr0.88LaCe0.12CuO4  

SciTech Connect (OSTI)

We use neutron scattering and specific heat measurements to relate the response of the spin fluctuations and static antiferromagnetic (AF) order to the superconductivity in the electron-doped high-transition-temperature superconductor, Pr{sub .88}LaCe{sub .12}CuO{sub 4-{delta}} (PLCCO) (T{sub c} = 24 K), as the system is tuned via a magnetic field applied beyond the upper critical field (H{sub c2}) and driven into the normal state. The strength of the collective magnetic excitation commonly termed 'resonance' decreases smoothly with increasing field and vanishes in the normal state, paralleling the behavior of the superconducting condensation energy. The suppression of superconductivity is accompanied by a smooth reduction in the very low energy spin fluctuations, and the concomitant emergence of static AF order. Our results suggest an intimate connection between the resonance and the superconducting condensation energy.

Dai, Pengcheng [ORNL; Wilson, Stephen D. [University of Tennessee, Knoxville (UTK); Li, Shiliang [University of Tennessee, Knoxville (UTK); Wen, H. H. [Chinese Academy of Sciences

2008-01-01T23:59:59.000Z

364

Superconducting Cable  

DOE Patents [OSTI]

In order to provide a flexible oxide superconducting cable which is reduced in AC loss, tape-shaped superconducting wires covered with a stabilizing metal are wound on a flexible former. The superconducting wires are preferably laid on the former at a bending strain of not more than 0.2%. In laying on the former, a number of tape-shaped superconducting wires are laid on a core member in a side-by-side manner, to form a first layer. A prescribed number of tape-shaped superconducting wires are laid on top of the first layer in a side-by-side manner, to form a second layer. The former may be made of a metal, plastic, reinforced plastic, polymer, or a composite and provides flexibility to the superconducting wires and the cable formed therewith.

Hughey, Raburn L. (Franklin, GA); Sinha, Uday K. (Carrollton, GA); Reece, David S. (Carrollton, GA); Muller, Albert C. (Eidson, TN)

2005-07-22T23:59:59.000Z

365

Superconducting Cable  

DOE Patents [OSTI]

In order to provide a flexible oxide superconducting cable which is reduced in AC loss, tape-shaped superconducting wires covered with a stabilizing metal are wound on a flexible former. The superconducting wires are preferably laid on the former at a bending strain of not more than 0.2%. In laying on the former, a number of tape-shaped superconducting wires are laid on a core member in a side-by-side manner, to form a first layer. A prescribed number of tape-shaped superconducting wires are laid on top of the first layer in a side-by-side manner, to form a second layer. The former may be made of a metal, plastic, reinforced plastic, polymer, or a composite and provides flexibility to the superconducting wires and the cable formed therewith.

Hughey, Raburn L. (Franklin, GA); Sinha, Uday K. (Carrollton, GA); Reece, David S. (Carrollton, GA); Muller, Albert C. (Eidson, TN)

2005-03-08T23:59:59.000Z

366

Influence of interfacial disorder and temperature on magnetization reversal in exchange-coupled bilayers  

SciTech Connect (OSTI)

Polarized neutron reflectometry is used to measure the thermal response of the net-magnetization vector of polycrystalline ferromagnetic (F) Fe films exchange coupled to twinned (110) MnF{sub 2} antiferromagnetic (AF) layers. We observe a strong correlation between the temperature dependencies of the net sample magnetization perpendicular to the applied field at coercivity and exchange bias. For cooling field and measurement conditions involving magnetization reversal via rotation, we find a range of temperature dependencies. For the smoothest F-AF interface, the temperature dependence of exchange bias compares well to a S=5/2 Brillouin function -- an observation predicted by some theoretical models. This temperature dependence is expected for the sublattice magnetization and the square root of the anisotropy constant K{sub 1} of bulk MnF{sub 2}. In contrast, for a rough F-AF interface the magnetization reversal process (and exchange bias) showed little temperature dependence up to temperatures approaching the AF Neel point -- a clear consequence of increasing interfacial disorder in a F-AF epitaxial system.

Fitzsimmons, M. R.; Leighton, C.; Hoffmann, A.; Yashar, P. C.; Nogues, J.; Liu, K.; Majkrzak, C. F.; Dura, J. A.; Fritzsche, H.; Schuller, Ivan K.

2001-09-01T23:59:59.000Z

367

Field-dependent critical state of high-Tc superconducting strip simultaneously exposed to transport current and perpendicular magnetic field  

SciTech Connect (OSTI)

We present an exact analytical approach for arbitrary field-dependent critical state of high-T{sub c} superconducting strip with transport current. The sheet current and flux-density profiles are derived by solving the integral equations, which agree with experiments quite well. For small transport current, the approximate explicit expressions of sheet current, flux-density and penetration depth for the Kim model are derived based on the mean value theorem for integration. We also extend the results to the field-dependent critical state of superconducting strip in the simultaneous presence of applied field and transport current. The sheet current distributions calculated by the Kim model agree with experiments better than that by the Bean model. Moreover, the lines in the I{sub a}-B{sub a} plane for the Kim model are not monotonic, which is quite different from that the Bean model. The results reveal that the maximum transport current in thin superconducting strip will decrease with increasing applied field which vanishes for the Bean model. The results of this paper are useful to calculate ac susceptibility and ac loss.

Xue, Cun; He, An; Yong, Huadong; Zhou, Youhe, E-mail: zhouyh@lzu.edu.cn [Key Laboratory of Mechanics on Disaster and Environment in Western China attached to the Ministry of Education of China, and Department of Mechanics and Engineering Sciences, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China)] [Key Laboratory of Mechanics on Disaster and Environment in Western China attached to the Ministry of Education of China, and Department of Mechanics and Engineering Sciences, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China)

2013-12-15T23:59:59.000Z

368

Atomic magnetic gradiometer for room temperature high sensitivity magnetic field detection  

DOE Patents [OSTI]

A laser-based atomic magnetometer (LBAM) apparatus measures magnetic fields, comprising: a plurality of polarization detector cells to detect magnetic fields; a laser source optically coupled to the polarization detector cells; and a signal detector that measures the laser source after being coupled to the polarization detector cells, which may be alkali cells. A single polarization cell may be used for nuclear magnetic resonance (NMR) by prepolarizing the nuclear spins of an analyte, encoding spectroscopic and/or spatial information, and detecting NMR signals from the analyte with a laser-based atomic magnetometer to form NMR spectra and/or magnetic resonance images (MRI). There is no need of a magnetic field or cryogenics in the detection step, as it is detected through the LBAM.

Xu,Shoujun (Berkeley, CA); Lowery, Thomas L. (Belmont, MA); Budker, Dmitry (El Cerrito, CA); Yashchuk, Valeriy V. (Richmond, CA); Wemmer, David E. (Berkeley, CA); Pines, Alexander (Berkeley, CA)

2009-08-11T23:59:59.000Z

369

Low-temperature magnetization of (Ga,Mn) As semiconductors  

E-Print Network [OSTI]

der Laan,8 C. T. Foxon,2 and B. L. Gallagher2 1Institute of Physics ASCR, Cukrovarnick? 10, 162 53 Praha 6, Czech Republic 2School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom 3Institute of Physics ASCR, Na... is organized as follows. In Sec. II we identify the key physical considerations related to ground-state mag- netization of #1;Ga,Mn#2;As ferromagnets by focusing first on a single Mn#1;d5+hole#2; complex and approximating the total magnetization...

Jungwirth, T.; Masek, J.; Wang, KY; Edmonds, KW; Sawicki, M.; Polini, M.; Sinova, Jairo; MacDonald, AH; Campion, RP; Zhao, LX; Farley, NRS; Johal, TK; van der Laan, G.; Foxon, CT; Gallagher, BL.

2006-01-01T23:59:59.000Z

370

Influence of a constant magnetic field on the dispersion of surface magnetostatic waves in a structure consisting of ferrite and granular high-temperature superconductor  

Science Journals Connector (OSTI)

The dispersional properties of a surface magnetostatic wave (MSW) in a laminar structure consisting of ferrite film and a high-temperature superconducting (HTSC) layer are studied in detail. The propagation of...

V. A. Krakovskii; E. S. Kovalenko

1996-06-01T23:59:59.000Z

371

Superconducting inductive displacement detection of a microcantilever  

E-Print Network [OSTI]

We demonstrate a superconducting inductive technique to measure the displacement of a micromechanical resonator. In our scheme, a type I superconducting microsphere is attached to the free end of a microcantilever and approached to the loop of a dc Superconducting Quantum Interference Device (SQUID) microsusceptometer. A local magnetic field as low as 100 $\\mu$T, generated by a field coil concentric to the SQUID, enables detection of the cantilever thermomechanical noise at $4.2$ K. The magnetomechanical coupling and the magnetic spring are in good agreement with image method calculations assuming pure Meissner effect. These measurements are relevant to recent proposals of quantum magnetomechanics experiments based on levitating superconducting microparticles.

Andrea Vinante

2014-05-14T23:59:59.000Z

372

Spontaneous Fluctuations of a Temperature Filament in a Magnetized Plasma  

E-Print Network [OSTI]

, and G. J. Morales Department of Physics and Astronomy, University of California, Los Angeles, California because temperature laments can arise in a wide class of plasma environments, e.g., solar corona 3G generated in the Large Plasma Device LAPD at the University of California, Los Angeles. For the purposes

California at Los Angles, University of

373

Critical Endpoint and Inverse Magnetic Catalysis for Finite Temperature and Density Quark Matter in a Magnetic Background  

E-Print Network [OSTI]

In this article we study chiral symmetry breaking for quark matter in a magnetic background, $\\bm B$, at finite temperature and quark chemical potential, $\\mu$, making use of the Ginzburg-Landau effective action formalism. As a microscopic model to compute the effective action we use the renormalized quark-meson model. Our main goal is to study the evolution of the critical endpoint, ${\\cal CP}$, as a function of the magnetic field strength, and investigate on the realization of inverse magnetic catalysis at finite chemical potential. We find that the phase transition at zero chemical potential is always of the second order; for small and intermediate values of $\\bm B$, ${\\cal CP}$ moves towards small $\\mu$, while for larger $\\bm B$ it moves towards moderately larger values of $\\mu$. Our results are in agreement with the inverse magnetic catalysis scenario at finite chemical potential and not too large values of the magnetic field, while at larger $\\bm B$ direct magnetic catalysis sets in.

M. Ruggieri; L. Oliva; P. Castorina; R. Gatto; V. Greco

2014-02-04T23:59:59.000Z

374

Low temperature magnetic properties of magnesium substituted YbMnO{sub 3}  

SciTech Connect (OSTI)

Structural and magnetic properties of polycrystalline Yb{sub 1?x}Mg{sub x}MnO{sub 3} (x = 0, 0.05 and 0.10) hexagonal compounds prepared by solid state method, have been studied. The structural analyses of the samples were carried out by Rietveld analysis of neutron diffraction data. With increasing Mg content, we find that the lattice parameter a decreases and c increases whereas the overall Mn-O bond length decreases. Magnetization measured as a function of magnetic field at 2.5 K exhibits hysteresis, which is attributed to ferromagnetic like ordering of Yb{sup 3+} sublattice. Temperature dependence of ac magnetic susceptibility, ?{sub ac}(T), shows no signature of spin-glass behavior. ?”(T) exhibits a sudden increase at low temperatures which is due to ordering of Yb{sup 3+} sublattice.

Sattibabu, Bhumireddi, E-mail: bsb.satti@gmail.com; Bhatnagar, Anil K., E-mail: bsb.satti@gmail.com; Mohan, Dasari, E-mail: bsb.satti@gmail.com; Das, Dibakar, E-mail: bsb.satti@gmail.com; Sundararaman, Mahadevan, E-mail: bsb.satti@gmail.com [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad-500046 (India); Siruguri, Vasudeva; Rayaprol, Sudhindra [UGC-DAE Consortium for Scientific Research, Mumbai Centre, R-5 Shed, Bhabha Atomic Research Centre, Mumbai-400085 (India)

2014-04-24T23:59:59.000Z

375

Superconductive tunnel junction integrated circuit  

SciTech Connect (OSTI)

Josephson Junction integrated circuits of the current injection type and magnetically controlled type utilize a superconductive layer that forms both Josephson Junction electrode for the Josephson Junction devices on the integrated circuit as well as a ground plane for the integrated circuit. Large area Josephson Junctions are utilized for effecting contact to lower superconductive layers and islands are formed in superconductive layers to provide isolation between the groundplane function and the Josephson Junction electrode function as well as to effect crossovers. A superconductor-barrier-superconductor trilayer patterned by local anodization is also utilized with additional layers formed thereover. Methods of manufacturing the embodiments of the invention are disclosed.

Jillie, D.W. Jr.; Smith, L.N.

1984-02-07T23:59:59.000Z

376

Superconducting thermoelectric generator  

DOE Patents [OSTI]

Thermoelectricity is produced by applying a temperature differential to dissimilar electrically conducting or semiconducting materials, thereby producing a voltage that is proportional to the temperature difference. Thermoelectric generators use this effect to directly convert heat into electricity; however, presently-known generators have low efficiencies due to the production of high currents which in turn cause large resistive heating losses. Some thermoelectric generators operate at efficiencies between 4% and 7% in the 800{degrees} to 1200{degrees}C range. According to its major aspects and bradly stated, the present invention is an apparatus and method for producing electricity from heat. In particular, the invention is a thermoelectric generator that juxtaposes a superconducting material and a semiconducting material - so that the superconducting and the semiconducting materials touch - to convert heat energy into electrical energy without resistive losses in the temperature range below the critical temperature of the superconducting material. Preferably, an array of superconducting material is encased in one of several possible configurations within a second material having a high thermal conductivity, preferably a semiconductor, to form a thermoelectric generator.

Metzger, J.D.; El-Genk, M.S.

1994-01-01T23:59:59.000Z

377

Effect of magnetic field and temperature on the ferroelectric loop in MnWO4  

Science Journals Connector (OSTI)

The ferroelectric properties of MnWO4 single crystal have been investigated. Despite a relatively low remanent polarization, we show that the sample is ferroelectric. The shape of the ferroelectric loop of MnWO4 strongly depends on magnetic field and temperature. While its dependence does not directly correlate with the magnetocapacitance effect before the paraelectric transition, the effect of magnetic field on the ferroelectric polarization loop supports magnetoelectric coupling.

Bohdan Kundys; Charles Simon; Christine Martin

2008-05-12T23:59:59.000Z

378

Integrated electronic transport and thermometry at milliKelvin temperatures and in strong magnetic fields  

SciTech Connect (OSTI)

We fabricated a He-3 immersion cell for transport measurements of semiconductor nanostructures at ultra low temperatures and in strong magnetic fields. We have a new scheme of field-independent thermometry based on quartz tuning fork Helium-3 viscometry which monitors the local temperature of the sample's environment in real time. The operation and measurement circuitry of the quartz viscometer is described in detail. We provide evidence that the temperature of two-dimensional electron gas confined to a GaAs quantum well follows the temperature of the quartz viscometer down to 4 mK.

Samkharadze, N.; Kumar, A.; Csathy, G. A. [Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States); Manfra, M. J. [Department of Physics, Birck Nanotechnology Center, School of Materials Engineering, and School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Pfeiffer, L. N.; West, K. W. [Princeton University, Princeton, New Jersey 08544 (United States)

2011-05-15T23:59:59.000Z

379

Suppression of magnetism and development of superconductivity within the collapsed tetragonal phase of Ca[subscript 0.67]Sr[subscript 0.33]Fe[subscript 2]As[subscript 2] under pressure  

SciTech Connect (OSTI)

Structural and electronic characterizations of (Ca{sub 0.67}Sr{sub 0.33})Fe{sub 2}As{sub 2} have been performed as a function of pressure up to 12 GPa using conventional and designer diamond anvil cells. The compound (Ca{sub 0.67}Sr{sub 0.33})Fe{sub 2}As{sub 2} behaves intermediately between its end members, displaying a suppression of magnetism and the onset of superconductivity. Like other members of the AFe{sub 2}As{sub 2} family, (Ca{sub 0.67}Sr{sub 0.33})Fe{sub 2}As{sub 2} undergoes a pressure-induced isostructural volume collapse, which we associate with the development of As-As bonding across the mirror plane of the structure. This collapsed tetragonal phase abruptly cuts off the magnetic state and supports superconductivity with a maximum T{sub c} = 22.2 K. The maximum T{sub c} of the superconducting phase is not strongly correlated with any structural parameter, but its proximity to the abrupt suppression of magnetism as well as the volume-collapse transition suggests that magnetic interactions and structural inhomogeneity may play a role in its development.

Jeffries, J.R.; Butch, N.P.; Kirshenbaum, K.; Saha, S.R.; Samudrala, G.; Weir, S.T.; Vohra, Y.K.; Paglione, J. (LLNL); (UAB); (Maryland)

2012-10-24T23:59:59.000Z

380

Design of A Conduction-cooled 4T Superconducting Racetrack for Multi-field Coupling Measurement System  

E-Print Network [OSTI]

A conduction-cooled superconducting magnet producing a transverse field of 4 Tesla has been designed for the new generation multi-field coupling measurement system, which was used to study the mechanical behavior of superconducting samples at cryogenic temperature and intense magnetic fields. Considering experimental costs and coordinating with system of strain measurements by contactless signals (nonlinear CCD optics system), the racetrack type for the coil winding was chosen in our design, and a compact cryostat with a two-stage GM cryocooler was designed and manufactured for the superconducting magnet. The magnet was composed of a pair of flat racetrack coils wound by NbTi/Cu superconducting composite wires, a copper and stainless steel combinational form and two Bi2Sr2CaCu2Oy superconducting current leads. All the coils were connected in series and can be powered with a single power supply. The maximum central magnetic field is 4 T. In order to support the high stress and uniform thermal distribution in t...

Chen, Yuquan; Wu, Wei; Guan, Mingzhi; Wu, Beimin; Mei, Enming; Xin, Canjie

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Stability and Quench Protection for HTS Superconducting Magnets: Cooperative Research and Development Final Report, CRADA number CRD-05-00160  

SciTech Connect (OSTI)

NREL will perform deposition and testing of various dielectrics on high-temperature superconductors.

Ginley, D. S.

2010-07-01T23:59:59.000Z

382

Inelastic neutron scattering study of a nonmagnetic collapsed tetragonal phase of CaFe2As2: Evidence of the impact of spin fluctuations on superconductivity in the iron-arsenide compounds.  

SciTech Connect (OSTI)

The relationship between antiferromagnetic spin fluctuations and superconductivity has become a central topic of research in studies of superconductivity in the iron pnictides. We present unambiguous evidence of the absence of magnetic fluctuations in the non-superconducting collapsed tetragonal phase of CaFe2As2 via inelas- tic neutron scattering time-of-flight data, which is consistent with the view that spin fluctuations are a necessary ingredient for unconventional superconductivity in the iron pnictides. We demonstrate that the collapsed tetrag- onal phase of CaFe2As2 is non-magnetic, and discuss this result in light of recent reports of high-temperature superconductivity in the collapsed tetragonal phase of closely related compounds.

Soh, Jing Han [ORNL] [ORNL; Tucker, G. S. [Ames Laboratory and Iowa State University] [Ames Laboratory and Iowa State University; Pratt, Daniel K [ORNL] [ORNL; Abernathy, Douglas L [ORNL] [ORNL; Stone, Matthew B [ORNL] [ORNL; Ran, S. [Ames Laboratory and Iowa State University] [Ames Laboratory and Iowa State University; Budko, S L [Ames Laboratory and Iowa State University] [Ames Laboratory and Iowa State University; Canfield, P. C. [Ames Laboratory] [Ames Laboratory; Kreyssig, A. [Ames Laboratory and Iowa State University] [Ames Laboratory and Iowa State University; McQueeney, R. J. [Ames Laboratory] [Ames Laboratory; Goldman, A. I. [Ames Laboratory and Iowa State University] [Ames Laboratory and Iowa State University

2013-01-01T23:59:59.000Z

383

Engineering Division Superconducting  

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

10152014 Joseph V. Minervini 74 35 MW superconducting motor Superconducting Fault Current Limiter (SCFL) Technology & Engineering Division HTS (MgB 2 ) * DC superconducting...

384

Principal interactions in the magnetic system Fe{sub 1-x}Co{sub x}Si: Magnetic structure and critical temperature by neutron diffraction and SQUID measurements  

SciTech Connect (OSTI)

The compound Fe{sub 1-x}Co{sub x}Si is a good representative for a cubic magnet with Dzyaloshinskii-Moriya interaction. On the basis of the neutron diffraction and superconducting quantum interference device measurements, we built the H-T phase diagram for the compound with different x from 0.1 to 0.7. The same set of parameters governs the magnetic system for different x. These parameters are well interpreted in the framework of the recently developed theory [S. V. Maleyev, Phys. Rev. B 73, 174402 (2006)]. As a result, the spin-wave stiffness, the Dzyaloshinskii constant, the anisotropic exchange constant, and the spin-wave gap caused by the Dzyaloshinskii interaction have been obtained and plotted as a function of x. The changes of the magnetic structure with x can be well interpreted on the basis of our findings.

Grigoriev, S. V.; Maleyev, S. V.; Dyadkin, V. A. [Petersburg Nuclear Physics Institute, Gatchina, 188300 St. Petersburg (Russian Federation); Menzel, D.; Schoenes, J. [Institut fuer Physik der Kondensierten Materie, TU Braunschweig, 38106 Braunschweig (Germany); Eckerlebe, H. [GKSS Forschungszentrum, 21502 Geesthacht (Germany)

2007-09-01T23:59:59.000Z

385

26 Tesla DC Magnet for Neutron Scattering  

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

Previously, DC Magnets located at Neutron-Scattering Beamlines were commercially-manufactured superconducting magnets and limited to 17 T. A few pulsed magnet systems have been...

386

Achievement of a record electron temperature for a magnetic mirror device  

E-Print Network [OSTI]

We demonstrate plasma discharges with extremely high temperature of bulk electrons at the large axially symmetric magnetic mirror device GDT (Budker Institute, Novosibirsk). According to Thomson scattering measurements, the on-axis electron temperature averaged over several sequential shots is 660 $\\pm$ 50 eV with peak values exceeding 900 eV in few shots. This corresponds to at least threefold increase as compared to previous experiments both at the GDT and at other comparable machines, thus demonstrating the maximum quasi-stationary (~1 ms) electron temperature achieved in open traps. The breakthrough is made possible with application of sophisticated electron cyclotron resonance heating in addition to standard heating by neutral beams. The reported increase of the electron temperature along with previous experiments, which demonstrated high-density plasma confinement with $\\beta\\approx$ 60%, provide a firm basis for extrapolating to fusion relevant applications of open magnetic systems.

Bagryansky, P A; Lizunov, A A; Maximov, V V; Prikhodko, V V; Shalashov, A G; Soldatkina, E I; Solomakhin, A L; Yakovlev, D V

2014-01-01T23:59:59.000Z

387

Temperature dependence of the lower critical field and strong pinning in high-temperature superconductors  

Science Journals Connector (OSTI)

We show, within the framework of the Ginzburg-Landau theory, that both the conventional and the anomalous temperature dependence of the lower critical field observed in high-temperature superconductors may result from the flux penetration through a set of separated microdefects. Microdefects modeled by normal layers with proximity-induced superconductivity can produce drastic enhancement of the lower critical field at low temperatures and can provide strong-pinning centers. The pinning interaction between an isolated vortex and the normal layer is primarily magnetic at high temperatures. At low temperatures, magnetic interaction is reduced, due to the increase of the normal-layer coherence length.

Dragomir Davidovi? and Ljiljana Dobrosavljevi?-Gruji?

1991-02-01T23:59:59.000Z

388

The Progress on Low-Cost, High-Quality, High-Temperature Superconducting Tapes Deposited by the Combustion Chemical Vapor Deposition Process  

SciTech Connect (OSTI)

The innovative Combustion Chemical Vapor Deposition (CCVD) process is a non-vacuum technique that is being investigated to enable next generation products in several application areas including high-temperature superconductors (HTS). In combination with the Rolling Assisted Biaxially Textured Substrate (RABiTS) technology, the CCVD process has significant promise to provide low-cost, high-quality lengths of YBCO coated conductor. Over 100 meter lengths of both Ni and Ni-W (3 at. Wt.%) substrates with a surface roughness of 12-18 nm were produced. The CCVD technology has been used to deposit both buffer layer coatings as well as YBCO superconducting layers. Buffer layer architecture of strontium titanate (SrTiO{sub 3}) and ceria (CeO{sub 2}) have been deposited by CCVD on textured nickel substrates and optimized to appropriate thicknesses and microstructures to provide templates for growing PLD YBCO with a J{sub c} of 1.1 MA/cm{sup 2} at 77 K and self-field. The CCVD buffer layers have been scaled to meter plus lengths with good epitaxial uniformity along the length. A short sample cut from one of the lengths enabled high critical current density PLD YBCO. Films of CCVD YBCO superconductors have been grown on single crystal substrates with critical current densities over 1 MA/cm{sup 2}. In addition, superconducting YBCO films with an I{sub c} of 60 A/cm-width (J{sub c} = 1.5 MA/cm{sup 2}) were grown on ORNL RABiTS (CeO{sub 2}/YSZ/Y{sub 2}O{sub 3}/Ni/Ni-3W) using CCVD process.

Shoup, S.S.; White, M.K.; Krebs, S.L.; Darnell, N.; King, A.C.; Mattox, D.S.; Campbell, I.H.; Marken, K.R.; Hong, S.; Czabaj, B.; Paranthaman, M.; Christen, H.M.; Zhai, H.-Y. Specht, E.

2008-06-24T23:59:59.000Z

389

Interplay of stress, temperature, and giant magnetoimpedance in amorphous soft magnets  

Science Journals Connector (OSTI)

Giant Magnetoimpedance (GMI)-based sensing devices have attracted attention from both academia and industry due to their low cost flexibility and excellent sensitivity. Potential applications range widely from current and stress sensors navigation systems magnetic recording to more demanding ones such as field sensors for deep drilling and oil fracking at elevated temperature. To realize the latter the temperature dependence of GMI effect must be well understood. Herein we report a study on the GMI effect in a Cobalt-based amorphous microwire under temperature cycles between 20?°C–560?°C. The GMI ratio was observed to decrease from 126.1% at 20?°C to 68.5% at 230?°C rapidly drop at ?290?°C and reach a near zero value above 320?°C in the first half of the measurement where the temperature was increased. Upon cooling down from 560?°C to 20?°C the GMI ratio exhibits little variation at ?95% in the 260?°C–20?°C regime. Similarly the anisotropy-temperature profile was also observed to change irreversibly during the temperature cycle. Previous work has found the correlation between internal stress anisotropy permeability and GMI effect. We hypothesize that irreversibility in GMI-temperature and anisotropy-temperature profiles stem from internal relief in the amorphous structure which is locked in during the rapid cooling. In the subsequent temperature cycles the GMI-temperature and anisotropy-temperature profiles show little variation thus supporting the notion that the internal stress relief is complete after the first temperature cycle.

2014-01-01T23:59:59.000Z

390

Superconductivity in SrNi2P2 single crystals  

SciTech Connect (OSTI)

Heat capacity, magnetic susceptibility, and resistivity of SrNi{sub 2}P{sub 2} single crystals are presented, illustrating the structural transition at 325 K, and bulk superconductivity at 1.4 K. The magnitude of {Tc}, fits to the heat capacity data, the small upper critical field H{sub c2} = 390 Oe, and {kappa} = 2.1 suggests a conventional fully gapped superconductor. With applied pressure we find that superconductivity persists into the so-called 'collapsed tetragonal' phase, although the transition temperature is monotonically suppressed with increasing pressure. This argues that reduced dimensionality can be a mechanism for increasing the transition temperatures of layered NiP, as well as layered FeAs and NiAs, superconductors.

Ronning, Filip [Los Alamos National Laboratory; Bauer, Eric D [Los Alamos National Laboratory; Park, Tuscon [Los Alamos National Laboratory; Thompson, Joe D [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

391

Big fast vortices in the d-wave resonating valence bond theory of high-temperature superconductivity  

Science Journals Connector (OSTI)

The effect of proximity to a Mott insulating phase on the superflow properties of a d-wave superconductor is studied using the slave-boson U(1)-gauge-theory model. The model has two limits corresponding to superconductivity emerging either out of a “renormalized Fermi-liquid” or out of a non-Fermi-liquid regime. Three crucial physical parameters are identified: the size of the vortex as determined from the supercurrent it induces, the coupling of the superflow to the quasiparticles, and the “nondissipative time derivative” term. As the Mott phase is approached, the core size as defined from the supercurrent diverges, the coupling between superflow and quasiparticles vanishes, and the magnitude of the nondissipative time derivative dramatically increases. The dissipation due to a moving vortex is found to vary as the third power of the doping. The upper critical field and the size of the critical regime in which paraconductivity may be observed are estimated and found to be controlled by the supercurrent length scale.

L. B. Ioffe and A. J. Millis

2002-09-18T23:59:59.000Z

392

Nuclear Magnetic Relaxation in LiF at High Temperatures  

Science Journals Connector (OSTI)

Measurements of T1 and T2, the spin-lattice and spin-spin relaxation times, are reported for Li7 and F19 nuclei in a single crystal of LiF. T1(Li) has been measured from room temperature to the melting point (1120°K) and the other quantities from 830°K to the melting point. Above 620°K, relaxation is caused exclusively by the diffusion of Li and F ions. T1(Li), T2(Li), and T1(F) are mainly determined by ?Li, the jump frequency of Li ions, and T2(F) mainly by ?F. Using a theory of relaxation developed elsewhere, ?Li and ?F are obtained for the region of intrinsic diffusion as ?Li=1.7×1016exp(-1.81 eV/kT) and ?F=4.5×1017exp(-2.2 eV/kT). For the extrinsic region, the motional activation energy of Li ions is obtained as 0.71 eV. The values of ?Li are in good agreement with those obtained from conductivity measurements; to our knowledge, ?F has never been measured by other methods. Below 620°K quadrupolar relaxation due to lattice vibrations and relaxation by paramagnetic impurities become important, and rough values are obtained for these contributions to T1(Li). Large angular variations of T1 and T2 are observed in the region of relaxation due to atomic diffusion. T2(Li) and T1(Li) vary by a factor of 2 and 1.5, respectively, as a function of crystal orientation, in good agreement with theoretical prediction. A crude measurement of T1(Li) in molten LiF is discussed.

Maurice Eisenstadt

1963-10-15T23:59:59.000Z

393

Cylindrical Ising nanowire in an oscillating magnetic field and dynamic compensation temperature  

Science Journals Connector (OSTI)

Abstract The nonequilibrium magnetic properties of a spin-1/2 cylindrical Ising nanowire system with core/shell in an oscillating magnetic field are studied by using a mean-field approach based on the Glauber-type stochastic dynamics (DMFT). We employ the Glauber-type stochastic dynamics to construct set of the coupled mean-field dynamic equations. First, we study the temperature dependence of the dynamic order parameters to characterize the nature of the phase transitions and to obtain the dynamic phase transition points. Then, we investigate the temperature dependence of the total magnetization to find the dynamic compensation points as well as to determine the type of behavior. The phase diagrams in which contain the paramagnetic, ferromagnetic, ferrimagnetic, partially nonmagnetic, surface fundamental phases and tree mixed phases as well as reentrant behavior are presented in the reduced magnetic field amplitude and reduced temperature plane. According to values of Hamiltonian parameters, the compensation temperatures, or the N-, Q-, P-, R-, S-type behaviors.

Ersin Kantar; Mehmet Erta?

2014-01-01T23:59:59.000Z

394

E-Print Network 3.0 - anisotropic superconducting transition...  

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

susceptibility is anisotropic... Outline: 1. Superconductivity and Magnetic Fields 2. The Spin-Paramagnetic Transition 3. Spin... indicates an anisotropic ... Source:...

395

Fabrication and Characterization of Nano-Sized Magnetic Structures and Their Flux-Pinning Effects on Superconducting Thin Films  

E-Print Network [OSTI]

Energy Dissipation due to Vortex Motion .................................. 7 Vortex Pinning in the Ferromagnet-Superconductor Hybrid (FSH) . 9 II FABRICATION OF EMBEDDED FERROMAGNET..., as the external magnetic field increases above the lower critical field and below an upper critical field ??2 (?), the magnetic flux partially penetrates the sample in the form of tubes, or vortices (Fig.4). This state is said to be a vortex state or mixed...

Lee, Han Gil

2011-02-22T23:59:59.000Z

396

Study of the effects of high temperatures during quenches on the performance of a small Nb(3)Sn racetrack magnet  

SciTech Connect (OSTI)

Several high field Nb{sub 3}Sn magnets of different design are under development for future particle accelerators. The high levels of stored energy in these magnets and the high current densities in the conductor can cause high peak temperatures during a quench. The thermal gradients generated in the epoxy-impregnated magnet coils during the fast temperature rise can result in high thermo-mechanical stresses. Considering the sensitivity of Nb{sub 3}Sn to strain and epoxy cracks, it is important to define a maximum acceptable temperature in the coils during a quench which does not cause degradation of the magnet performance. A program was launched at Fermilab to study the effects of thermo-mechanical stress in Nb{sub 3}Sn coils, supported by experiments and by analysis. In collaboration with LBNL, a sub-scaled magnet was built and instrumented to measure the effect of the thermo-mechanical shock during magnet quenches. The magnet consisted of two racetrack coils, assembled in a common coil configuration with a small gap in between. During the test, the magnet reached the maximum field of {approx} 11 T at the short sample current of 9100 A. Temperature excursions up to 400 K did not diminish the magnet quench performance; only after temperature excursions over 430 K, the magnet showed detraining effects, which reduced occasionally the quench current of about 6%. Signs of irreversible degradation (reducing the maximum current of about 3%) appeared only after temperature excursions over 550 K.

Linda Imbasciati et al.

2004-03-23T23:59:59.000Z

397

Testing of the EURATOM LCT coil in the toroidal arrangement of the International Fusion Superconducting Magnet Test Facility without external pulsed fields (standard-1) and with them (standard II) and an extended single-coil test  

SciTech Connect (OSTI)

Testing of the European LCT coil, a forced-flow NbTi coil, with the five other coils in the International Fusion Superconducting Magnet Test Facility (IFSMTF) has been in progress since the beginning of 1986. By the end of July 1987, the Euratom-LCT coil had passed a single-coil test, a test in toroidal configuration with and without poloidal field transients, and an extended single-coil test up to its design limits. In this test, the coil reached, in stable operation, a field of 9 T at 140% of rated current. It reached the short-sample values of the strands used in the cable. The coil was operated up to 8 T with and without poloidal field transients in a toroidal configuration. The mass flow rate was reduced by a factor of 5 compared with the design value without any visible impact on stability. Averaged ac losses (winding, 14 W; case, 7 W) were measured under LCT specified poloidal field pulses, and the findings agreed with those of the short-sample measurements. The mechanical properties behaved as predicted by calculations. No global movement of the winding in the coil case was found, although the coil has already experienced 50% (14MN) of the maximum out-of-plane force. The operating limits were determined by measuring the current-sharing temperature. It was found that the helium mass flow rate had an impact on the hot-spot temperature of a normal region. All results obtained demonstrate that the applied technology has achieved reliable engineering standards.

Friesinger, G.; Gauss, S.; Komarek, P.; Lubell, M.S.; McManamy, T.J.; Maurer, W.; Shen, S.S.; Siewerdt, L.; Ulbricht, A.; Wuchner, F.

1988-03-01T23:59:59.000Z

398

Superconductivity above 20 K in the Ba-K-Bi-O system  

Science Journals Connector (OSTI)

The results of magnetic susceptibility measurements on multiphase Ba-K-Bi-O samples with overall composition Ba0.9KxBiO3 (x?0.2) provide evidence for superconductivity above 20 K in a minority fraction (?5%) of the sample volume. These results support the expectation that K doping at the inactive Ba donor sites can extend the metallic range of the previously studied BaPb1-xBixO3 alloys closer to the BaBiO3 Peierls instability where the strong coupling of the conduction electrons to the O phonons could explain the enhanced (Tc?22 vs 13 K) superconducting transition temperatures.

L. F. Mattheiss; E. M. Gyorgy; D. W. Johnson; Jr.

1988-03-01T23:59:59.000Z

399

Observation of magnetic moments in the superconducting state of YBa{sub 2}Cu{sub 3}O{sub 6.6}  

SciTech Connect (OSTI)

Neutron scattering measurements for YBa{sub 2}Cu{sub 3}O{sub 6.6} have identified small magnetic moments that increase in strength as the temperature is reduced below T{sup *} and further increase below T{sub c}. An analysis of the data shows the moments are antiferromagnetic between the Cu-O planes with a correlation length of longer than 195 {angstrom} in the a-b plane and about 35 {angstrom} along the c axis. The origin of the moments is unknown, and their properties are discusssed both in terms of Cu spin magnetism and orbital bond currents.

Mook, H. A.; Dai, Pengcheng; Dogan, F.

2001-07-01T23:59:59.000Z

400

Prospects of High Temperature Superconductors for fusion magnets and power applications  

Science Journals Connector (OSTI)

Abstract During the last few years, progress in the field of second-generation High Temperature Superconductors (HTS) was breathtaking. Industry has taken up production of long length coated REBCO conductors with reduced angular dependency on external magnetic field and excellent critical current density jc. Consequently these REBCO tapes are used more and more in power application. For fusion magnets, high current conductors in the kA range are needed to limit the voltage during fast discharge. Several designs for high current cables using High Temperature Superconductors have been proposed. With the REBCO tape performance at hand, the prospects of fusion magnets based on such high current cables are promising. An operation at 4.5 K offers a comfortable temperature margin, more mechanical stability and the possibility to reach even higher fields compared to existing solutions with Nb3Sn which could be interesting with respect to DEMO. After a brief overview of HTS use in power application the paper will give an overview of possible use of HTS material for fusion application. Present high current HTS cable designs are reviewed and the potential using such concepts for future fusion magnets is discussed.

Walter H. Fietz; Christian Barth; Sandra Drotziger; Wilfried Goldacker; Reinhard Heller; Sonja I. Schlachter; Klaus-Peter Weiss

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Previously, DC Magnets located at Neutron-Scattering Beamlines were commercially-manufactured superconducting magnets and limited to 17 T. A  

E-Print Network [OSTI]

Previously, DC Magnets located at Neutron-Scattering Beamlines were commercially, this was the first designed specifically for neutron scattering and the first to include resistive suitable for neutron scattering, diffraction and spectroscopy experiments with the neutron beam passing

Weston, Ken

402

X-Ray–Line Diagnostic of Magnetic Field Strength for High-Temperature Plasmas  

Science Journals Connector (OSTI)

An x-ray line diagnostic for use in magnetic field measurements in high-temperature plasmas has been identified. The intensity of the otherwise strictly forbidden 1s22s22p1/22p3/243s1/2??P03?1s22s22p6??S01 transition in neonlike ions is shown to depend on the magnetic field strength. The field dependence is illustrated between one and 3 T in the Ar8+ spectrum. The line is well resolved, bright, and close to reference lines, making it an experimentally simple to use diagnostic.

P. Beiersdorfer; J. H. Scofield; A. L. Osterheld

2003-06-13T23:59:59.000Z

403

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

SciTech Connect (OSTI)

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

Mihai, A. P.; Whiteside, A. L.; Canwell, E. J.; Marrows, C. H.; Moore, T. A., E-mail: t.a.moore@leeds.ac.uk [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Benitez, M. J.; McGrouther, D.; McVitie, S.; McFadzean, S. [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)] [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2013-12-23T23:59:59.000Z

404

National High Magnetic Field Laboratory - Coexistence of Superconducti...  

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

Coexistence of Superconductivity, Magnetism and FFLO States FFLO States The BCS (Bardeen, Cooper and Schrieffer, 1957) theory successfully explains conventional superconductivity...

405

Superconductivity program for electric systems, Superconductivity Technology Center, Los Alamos National Laboratory, annual progress report for fiscal year 1997  

SciTech Connect (OSTI)

Development of high-temperature superconductors (HTS) has undergone tremendous progress during the past year. Kilometer tape lengths and associated magnets based on BSCCO materials are now commercially available from several industrial partners. Superconducting properties in the exciting YBCO coated conductors continue to be improved over longer lengths. The Superconducting Partnership Initiative (SPI) projects to develop HTS fault current limiters and transmission cables have demonstrated that HTS prototype applications can be produced successfully with properties appropriate for commercial applications. Research and development activities at LANL related to the HTS program for Fiscal Year 1997 are collected in this report. LANL continues to support further development of Bi2223 and Bi2212 tapes in collaboration with American Superconductor Corporation (ASC) and Oxford Superconductivity Technology, Inc. (OSTI), respectively. The tape processing studies involving novel thermal treatments and microstructural characterization have assisted these companies in commercializing these materials. The research on second-generation YBCO-coated conductors produced by pulsed-laser deposition (PLD) over buffer template layers produced by ion beam-assisted deposition (IBAD) continues to lead the world. The applied physics studies of magnetic flux pinning by proton and heavy ion bombardment of BSCCO and YBCO tapes have provided many insights into improving the behavior of these materials in magnetic fields. Sections 4 to 7 of this report contain a list of 29 referred publications and 15 conference abstracts, a list of patent and license activities, and a comprehensive list of collaborative agreements in progress and completed.

Willis, J.O.; Newnam, B.E. [eds.; Peterson, D.E.

1999-03-01T23:59:59.000Z

406

Argonne National Laboratory Partners with Advanced Magnet Lab to Develop First Fully Superconducting Direct-Drive Generator  

Broader source: Energy.gov [DOE]

The Department of Energy (DOE) Argonne National Laboratory (ANL) is partnering with Advanced Magnet Lab, in Palm Bay, Florida, on one of six projects recently awarded by DOE to help develop next generation wind turbines and accelerate the deployment of advanced turbines for offshore wind energy in the United States.

407

IEEE TRANSACTIONSON APPLIED SUPERCONDUCTIVITY,VOL. I I, NO. I, MARCH 2001 I223 Magnetic Flux Controlled Josephson Array  

E-Print Network [OSTI]

-dimensional parallel arrays of Josephson junctions have the ability to perform as oscillators tunable hy magnetic flux, Josephsonjunction 1. INTRODUCTION RRAYS of parallel Josephson junctions can operate as Atunable oscillators [I Josephson junction in the array is inodcled using the RCSJ model. The junctions are resistively shunted

Orlando, Terry P.

408

Magnetic relaxation, current-voltage characteristics, and possible dissipation mechanisms for high-Tc superconducting thin films of Y-Ba-Cu-O  

Science Journals Connector (OSTI)

We propose a mechanism that may account for the temperature-insensitive relaxation of the magnetic-shielding current in epitaxial thin films of YBa2Cu3O7-?. We show that such relaxation is related to the shape of the current-voltage (J-E) characteristic of the superconductor in its critical state. The weak temperature dependence of the relaxation implies a temperature-insensitive J-E characteristic that resembles that of conventional type-II superconductors when a spatial variation of critical current density (Jc) is present. We suggest such a distribution of Jc as an explanation for the apparently large and temperature-insensitive relaxation observed in YBa2Cu3O7-?.

J. Z. Sun; C. B. Eom; B. Lairson; J. C. Bravman; T. H. Geballe

1991-02-01T23:59:59.000Z

409

Landscape of superconducting membranes  

E-Print Network [OSTI]

The AdS/CFT correspondence may connect the landscape of string vacua and the `atomic landscape' of condensed matter physics. We study the stability of a landscape of IR fixed points of N=2 large N gauge theories in 2+1 dimensions, dual to Sasaki-Einstein compactifications of M theory, towards a superconducting state. By exhibiting instabilities of charged black holes in these compactifications, we show that many of these theories have charged operators that condense when the theory is placed at a finite chemical potential. We compute a statistical distribution of critical superconducting temperatures for a subset of these theories. With a chemical potential of one milliVolt, we find critical temperatures ranging between 0.24 and 165 degrees Kelvin.

Frederik Denef; Sean A. Hartnoll

2009-03-20T23:59:59.000Z

410

Performance of silicon PIN photodiodes at low temperatures and in high magnetic fields  

E-Print Network [OSTI]

The performance of a Si PIN diode (type Hamamatsu S3590-06) as an energy sen- sitive detector operating at cryogenic temperatures (~10 K) and in magnetic fields up to 11 T was investigated, using a 207Bi conversion electron source. It was found that the detector still performs well under these conditions, with small changes in the response function being observed in high magnetic fields, e.g. a 30% to 50% decrease in energy resolution. A GEANT4 Monte Carlo simulation showed that the observed effects are mainly due to the modified trajectories of the electrons due to the influence of the magnetic field, which changes the scattering conditions, rather than to intrinsic changes of the performance of the detector itself.

F. Wauters; I. S. Kraev; M. Tandecki; E. Traykov; S. Van Gorp; D. Zakoucky; N. Severijns

2008-12-31T23:59:59.000Z

411

Ising-Glauber Spin Cluster Model for Temperature-Dependent Magnetization Noise in SQUIDs  

Science Journals Connector (OSTI)

Clusters of interacting two-level-systems, likely due to Farbe+(F+) centers at the metal-insulator interface, are shown to self-consistently lead to 1/f? magnetization noise [with ?(T)?1] in SQUIDs. Model calculations, based on a new method of obtaining correlation functions, explains various puzzling experimental features. It is shown why the inductance noise is inherently temperature dependent while the flux noise is not, despite the same underlying microscopics. Magnetic ordering in these systems, established by three-point correlation functions, explains the observed flux- inductance-noise cross correlations. Since long-range ferromagnetic interactions are shown to lead to a more weakly temperature dependent flux noise when compared to short-range interactions, the time reversal symmetry of the clusters is also not likely broken by the same mechanism which mediates surface ferromagnetism in nanoparticles and thin films of the same insulator materials.

Amrit De

2014-11-18T23:59:59.000Z

412

Study of the change of electron temperature inside magnetic island caused by localized radio frequency heating  

SciTech Connect (OSTI)

The change in the electron temperature inside magnetic island caused by localized radio frequency (rf) heating is studied numerically by solving the two-dimensional energy transport equation, to investigate the dependence of the temperature change on the location and width of the rf power deposition along the minor radius and the helical angle, the island width, and the ratio between the parallel and the perpendicular heat conductivity. Based on obtained numerical results, suggestions for optimizing the island stabilization by localized rf heating are made.

Yang, J.; Zhu, S. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031 (China); Yu, Q. [Max-Planck-Institute fuer Plasmaphysik, EURATOM Association, Garching 85748 (Germany); Zhuang, G. [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

2010-05-15T23:59:59.000Z

413

SQUID gradiometer for ultra-low temperature magnetic micro-calorimeter  

Science Journals Connector (OSTI)

First-order integrated planar SQUID gradiometers with pick-up loops of 40 µm in diameter and a baseline of 200 µm were designed specially for the readout of signals from magnetic micro-calorimeters. The SQUID has to operate in magnetic fields up to 5 mT and at temperatures down to 7 mK. The design is a first step to develop a multi-pixel x-ray detector, which can be used in high-resolution x-ray fluorescence analysis. Chip coils with a heater switch produce a magnetic field up to a few millitesla in persistent current mode. A SQUID-array amplifier was used to readout the signal of the SQUID gradiometer. The intrinsic noise of the gradiometer at 4.2 K is lower than 1 ??0 Hz?1/2. The SQUID can withstand external magnetic fields up to 7 mT without losing its performance. The results of a test with the SQUID gradiometer at ultra low temperatures are reported.

V Zakosarenko; R Stolz; L Fritzsch; H-G Meyer; A Fleischmann; C Enns

2003-01-01T23:59:59.000Z

414

Two-colour QCD at non-zero temperature in the presence of a strong magnetic field  

E-Print Network [OSTI]

In this talk we report on our study of two-colour lattice QCD with N_f=4 staggered fermion degrees of freedom with equal electric charge q in a homogeneous magnetic field B at non-zero temperature T. We find indications for a non-monotonic behaviour of the critical temperature as a function of the magnetic field strength and, as a consequence, for the occurence of `inverse magnetic catalysis' within the transition region for magnetic fields in the range 0 < qB < 0.7 GeV^2.

M. Muller-Preussker; B. Petersson; A. Schreiber; E. -M. Ilgenfritz; M. Kalinowski

2014-02-01T23:59:59.000Z

415

Room-Temperature Ferromagnetism in a II-VI Diluted Magnetic Semiconductor Zn1-xCrxTe  

Science Journals Connector (OSTI)

The magnetic and magneto-optical properties of a Cr-doped II-VI semiconductor ZnTe were investigated. Magnetic circular dichroism measurements showed a strong interaction between the sp carriers and localized d spins, indicating that Zn1-xCrxTe is a diluted magnetic semiconductor. The Curie temperature of the film with x=0.20 was estimated to be 300±10???K, which is the highest value ever reported for a diluted magnetic semiconductor in which sp-d interactions were confirmed. In spite of its high Curie temperature, Zn1-xCrxTe film shows semiconducting electrical transport properties.

H. Saito; V. Zayets; S. Yamagata; K. Ando

2003-05-20T23:59:59.000Z

416

Phase-Boundary of a Cubic Superconducting Circuit in a Magnetic-Field of Arbitrary Magnitude and Direction  

E-Print Network [OSTI]

[a /g( T) ] is the eigenvalue; n?:sinu cosp, n~ =sina sinp, and n, ?:cosa are the directional cosines describing the direction of the applied magnetic field H relative to the axes of the cube, with a and p the polar angles of H, so that H=H(n e +n e... for P is 360', but the curves have 90 periodicity, and within each period, they have mirror symmetry about the midpoint, so only the range f3=0 ?45' needs to be presented. These symmetries are, of course, those of a cube. (The same cubic symmetry...

Hu, Chia-Ren; HUANG, CH.

1991-01-01T23:59:59.000Z

417

MOTT INSULATORS, SPIN LIQUIDS AND QUANTUM DISORDERED SUPERCONDUCTIVITY  

E-Print Network [OSTI]

COURSE 7 MOTT INSULATORS, SPIN LIQUIDS AND QUANTUM DISORDERED SUPERCONDUCTIVITY MATTHEW P.A. FISHER insulators and quantum magnetism 583 3.1 Spin models and quantum magnetism . . . . . . . . . . . . . . . . . . . . . . . . . . . . 637 #12;MOTT INSULATORS, SPIN LIQUIDS AND QUANTUM DISORDERED SUPERCONDUCTIVITY Matthew P.A. Fisher

418

Modeling of Shield-Type Superconducting Fault-Current-Limiter Operation Considering Flux Pinning Effect on Flux and Supercurrent Density in High-Temperature Superconductor Cylinders  

Science Journals Connector (OSTI)

Superconducting fault current limiter, SFCL, forms an important category of fault-current-limiting devices which limit the short-circuit current levels in electrical networks. Therefore, modeling ... its main ope...

Arsalan Hekmati

2014-03-01T23:59:59.000Z

419

Detection limits of high temperature superconducting materials on various substrates by energy dispersive X-ray fluorescence and proton induced X-ray emission methods  

Science Journals Connector (OSTI)

Application of energy dispersive X-ray fluorescence (EDXRF) and proton induced X-ray emission (PIXE) methods has been demonstrated for determining the elemental composition of thin film superconducting materia...

M Lal; H N Bajpai; D Joseph; R K Choudhury

1990-04-01T23:59:59.000Z

420

Steady state heat transfer experimental studies of LHC superconducting cables operating in cryogenic environment of superfluid helium  

E-Print Network [OSTI]

The heat management is a basic and fundamental aspect of the superconducting magnets used in the CERN Large Hadron Collider. Indeed, the coil temperature must be kept below the critical value, despite the heat which can be generated or deposited in the magnet during the normal operations. Therefore, this thesis work aims at determining the heating power which can be extracted from the superconducting cables of the LHC, specially through their electrical insulation which represents the main thermal barrier. An experimental measurement campaign in superfluid helium bath was performed on several samples reproducting the main LHC magnets. The heating power was generated in the sample by Joule heating and the temperature increase was measured by means of Cernox bare chip and thermocouples. An innovative instrumentation technique which also includes the in-situ calibration of the thermocouples was developed. A thorough uncertainty analysis on the overall measurement chain concluded the experimental setup. The prese...

Santandrea, Dario; Tuccillo, Raffaele;; Granieri, Pier Paolo.

Note: This page contains sample records for the topic "temperature superconducting magnetic" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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421

Superconductive articles including cerium oxide layer  

DOE Patents [OSTI]

A ceramic superconductor comprising a metal oxide substrate, a ceramic high temperature superconductive material, and a intermediate layer of a material having a cubic crystal structure, said layer situated between the substrate and the superconductive material is provided, and a structure for supporting a ceramic superconducting material is provided, said structure comprising a metal oxide substrate, and a layer situated over the surface of the substrate to substantially inhibit interdiffusion between the substrate and a ceramic superconducting material deposited upon said structure. 7 figures.

Wu, X.D.; Muenchausen, R.E.

1993-11-16T23:59:59.000Z

422

Proximity effects in superconducting triplet spin-valve F2/F1/S  

Science Journals Connector (OSTI)

Abstract We investigate the critical temperature Tc of F2/F1/S trilayers (Fi is a ferromagnetic metal and S is a singlet superconductor), where the long-range triplet superconducting component is generated at noncollinear magnetizations of the F layers. In this paper we demonstrate a possibility of the spin-valve effect mode selection (standard switching effect, the triplet spin-valve effect or reentrant T c ( ? ) dependence) by the variation of the F2/F1 interface transparency.

R.G. Deminov; L.R. Tagirov; R.R. Gaifullin; T.Yu. Karminskaya; M.Yu. Kupriyanov; Ya.V. Fominov; A.A. Golubov

2015-01-01T23:59:59.000Z

423

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

SciTech Connect (OSTI)

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.

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

1997-04-01T23:59:59.000Z

424

Steady-State Heat Transfer in He II through Porous Superconducting Cable Insulation  

Science Journals Connector (OSTI)

The LHC program includes the study of thermal behavior of the superconducting cables wound in the dipole magnet cooled by superfluid helium (He II). Insulation of these superconducting cables forms the major ... ...

B. J. P. Baudouy; F.-P. Juster; C. Meuris…

1996-01-01T23:59:59.000Z

425

Temperature dependences of superconducting critical current density and upper critical field for V/sub 2/(Hf,Zr) multifilamentary wire  

SciTech Connect (OSTI)

The temperature dependences of the critical current density, J /SUB c/ , and the upper critical field, uH /SUB c2/ , have been studied for newly developed V/sub 2/(Hf,Zr) multifilamentary wires. At 4.2 K, a ..mu..H /SUB c2/ of 22 T and an overall J /SUB c/ of 1 x 10/sup 4/ A/cm/sup 2/ at 17 T are obtained for these wires. At 1.8 K, overall J /SUB c/ in 15 T of these wires are twice as large as that of the bronze-processed Nb/sub 3/Sn multifilamentary wire. The enhanced J /SUB c/ at reduced temperatures may be attributed to the rapid increase in ..mu..H /SUB c2/ by using the temperature scaling law of the pinning force density. ..mu..H /SUB c2/ measured in pulsed fields is about 28 T at 2.0 K. According to the temperature scaling law, the overall J /SUB c/ for 1.8 K and at 20 T is estimated to be 2 x 10/sup 4/ A/cm/sup 2/. Thus, the present V/sup 2/(Hf,Zr) multifilamentary wires are very promising for use of generating high magnetic fields in the superfluid liquid helium environment.

Inoue, K.; Kuroda, T.; Tachikawa, K.

1985-03-01T23:59:59.000Z

426

Temperature dependence of magnetic behaviour in very fine grained, spark plasma sintered NiCuZn Ferrites  

E-Print Network [OSTI]

with wide bandwidth up to 30MHz. In this paper the frequency range of 100 kHz to 5 MHz is investigated the magnetization processes taking place in these nano grained materials, in the frequency interval of 100kHz to 5Temperature dependence of magnetic behaviour in very fine grained, spark plasma sintered Ni

Boyer, Edmond

427

Electrostatic wave structures in a magnetized superthermal plasma with two-temperature electrons  

SciTech Connect (OSTI)

The linear and nonlinear excitation of arbitrary amplitude ion-acoustic (IA) solitary waves in a magnetized plasma comprising two-temperature electrons and cold ions are studied. The oblique propagation properties of two possible modes (in the linear regime) are investigated. It is found that the electron superthermality reduces the phase velocities of both modes, whereas obliqueness leads to an increase in the separation between two modes. In the nonlinear regime, an energy-like equation describes the evolution of IA solitary waves in the present model. The combined effects of the electron superthermality, magnitude of magnetic field, obliqueness and electron population are incorporated in the study of the existence domain of solitary waves and the soliton characteristics. It is shown that the small values of the hot electron population shift the permitted interval of Mach number to the lower values. Both compressive and rarefactive solitary structures are found to exist in the presence of two temperature electrons. The present investigation contributes to the physics of electrostatic wave structures in Saturn's magnetosphere in which two temperature electrons with kappa distribution exist.

Shahmansouri, M. [Department of Physics, Faculty of Science, Arak University, Arak 38156- 8 8349 (Iran, Islamic Republic of)] [Department of Physics, Faculty of Science, Arak University, Arak 38156- 8 8349 (Iran, Islamic Republic of); Alinejad, H. [Department of Physics, Faculty of Basic Science, Babol University of Technology, Babol 47148-71167 (Iran, Islamic Republic of)] [Department of Physics, Faculty of Basic Science, Babol University of Technology, Babol 47148-71167 (Iran, Islamic Republic of)

2013-08-15T23:59:59.000Z

428

Fabrication of arrays of nano-superconducting quantum interfernce devices using a double-angle processing approach  

E-Print Network [OSTI]

SQUIDs) from high-temperature superconductors such as YBCOsuperconductors. However, the thermal noise inform the increased operating temperature os high-high-temperature superconductivity, Josephson junctions, electron beam lithography I. I NTRODUCTION Superconducting interference devices (SQUIDs) from conventional superconductors

Roediger, Peter

2014-01-01T23:59:59.000Z

429

IEFIT - An Interactive Approach to High Temperature Fusion Plasma Magnetic Equilibrium Fitting  

SciTech Connect (OSTI)

An interactive IDL based wrapper, IEFIT, has been created for the magnetic equilibrium reconstruction code EFIT written in FORTRAN. It allows high temperature fusion physicists to rapidly optimize a plasma equilibrium reconstruction by eliminating the unnecessarily repeated initialization in the conventional approach along with the immediate display of the fitting results of each input variation. It uses a new IDL based graphics package, GaPlotObj, developed in cooperation with Fanning Software Consulting, that provides a unified interface with great flexibility in presenting and analyzing scientific data. The overall interactivity reduces the process to minutes from the usual hours.

Peng, Q.; Schachter, J.; Schissel, D.P.; Lao, L.L.

1999-06-01T23:59:59.000Z

430

Molybdenum-rhenium superconducting suspended nanostructures  

SciTech Connect (OSTI)

Suspended superconducting nanostructures of MoRe 50%/50% by weight are fabricated employing commonly used fabrication steps in micro- and nano-meter scale devices followed by wet-etching with Hydro-fluoric acid of a SiO{sub 2} sacrificial layer. Suspended superconducting channels as narrow as 50?nm and length 3??m have a critical temperature of ?6.5?K, which can increase by 0.5?K upon annealing at 400?°C. A detailed study of the dependence of the superconducting critical current and critical temperature upon annealing and in devices with different channel widths reveals that desorption of contaminants is responsible for the improved superconducting properties. These findings pave the way for the development of superconducting electromechanical devices using standard fabrication techniques.

Aziz, Mohsin; Christopher Hudson, David; Russo, Saverio [Centre for Graphene Science, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF (United Kingdom)

2014-06-09T23:59:59.000Z

431

At the Frontiers of Science Superconductivity and Its Electric Power Applications  

SciTech Connect (OSTI)

Electricity - it is one of our modern scientific miracles, and today we could not imagine living without it. But what if we could make it better? Superconductivity has the potential to do just that, by improving the capacity, quality, and reliability of products that use electricity. There has been a great deal of discussion about superconductivity in the last 10 years, but what exactly is it? In this document you will learn the definition of superconductivity, how it works, and its present and potential uses. You will also get an inside look at the challenges that scientists around the world are working to overcome in order to fully incorporate superconductivity in our everyday lives. When you turn on a lamp at home, the electric current flows - is conducted - through a wire made of copper or aluminum. Along the way, this wire resists the flow of electricity, and this resistance is something very much like friction. The resistance causes some of the electricity to be lost in the form of heat. Which means that every time you use an appliance, from a radio to a generator, you are not getting 100% of the energy that flows through it; some of it is wasted by the conductor. Superconductivity - the ability of a material to conduct electricity without losses to resistance - is a physical property inherent to a variety of metals and ceramics, much the same way magnetism is present in a variety of materials. It is dependent on temperature; that is, a material will not exhibit superconductivity until it is sufficiently cold. The necessary temperatures to induce superconductivity are well below what we might commonly consider 'cold.' They are so low, in fact, that they are measured using the Kelvin temperature scale (K). Absolute zero, or 0 K, is equal to -459 Fahrenheit (F). It is defined as the lowest temperature theoretically possible, or the complete absence of heat. In 1911, working in a laboratory in Holland, the Dutch scientist Heike Kamerlingh Onnes cooled mercury to 4 K (-452 F), almost absolute zero; at this temperature, the motion of individual atoms nearly ceased. Scientists were unsure what effect this extremely low temperature would have on resistance; most suspected resistance would increase as atomic motion slowed. However, during routine measurements of the mercury, it appeared that there was no electrical resistance. Onnes assumed his equipment was broken, but days later he confirmed that, near absolute zero, mercury did completely lose electrical resistance. Onnes had discovered superconductivity.

None

1998-07-01T23:59:59.000Z

432

Effects of lithium additions on processing of Bi-Sr-Ca-Cu-O superconducting tapes  

SciTech Connect (OSTI)

Lithium additions to the high-temperature superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} (2212) increased superconducting transition temperatures and improved resistance to effects of magnetic fields. In addition, these additions lowered the melting point of 2212 and increased reaction kinetics. Ag-clad tapes fabricated from 2212 with and without Li exhibited profound differences. For heating to temperatures less than or equal to 840{degrees}C, grain growth and sintering were much more substantial in the tapes containing Li.

Goretta, K.C.; Li, Y.F.; Poeppel, R.B. [Argonne National Lab., IL (United States); Wu, S.; Guo, J. [Illinois Univ., Urbana, IL (United States). Dept. of Nuclear Engineering; Schwartz, J. [Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Laboratory

1994-01-01T23:59:59.000Z

433

Magnetic susceptibility of PrMg3 at ultra low temperatures  

Science Journals Connector (OSTI)

We report susceptibility measurements of PrMg3 with a non-magnetic T3 crystalline-electric-field ground state down to 0.3 mK. The susceptibility shows the Van-Vleck-like behavior with an additional logarithmic temperature dependence below 10 K. Furthermore, the susceptibility exhibits a small peak around 0.1 K, which is attributed to the quenching of the multipole degrees of freedom. Below 30 mK, the susceptibility is almost constant down to the lowest temperature without showing the contribution of Pr nuclear spins. The disappearance of nuclear spin contribution suggests that the quenching of the multipole degrees of freedom strongly affects the nuclear spin system.

J Yoshida; S Abe; A Tada; H Tsujii; K Matsumoto; H Suzuki; H S Suzuki

2009-01-01T23:59:59.000Z

434

Superconducting micronets: The Wheatstone bridge  

Science Journals Connector (OSTI)

Using the Ginzburg-Landau theory, a particular superconducting (sc) micronet, called the Wheatstone bridge, is studied. This planar micronet is made of two nodes connected by three thin sc wires. A magnetic field is applied perpendicularly to its plane. The sc-normal second-order phase transition is characterized by only two configurations of the order parameter: cphiA=cphiB and cphiA=-cphiB, where cphiA and cphiB are the order parameters at the nodes. For temperatures near Tc, we show that only the cphiA=cphiB configuration is admissible for fluxes near ?=n?0, where n is an integer and ?0 is the flux quantum. Finally, the exact solution of the nonlinear Ginzburg-Landau equations for one-dimensional systems is numerically fitted to the boundary conditions of the Wheatstone bridge for the two configurations cphiA=cphiB and cphiA=-?B. Graphs of the Gibbs energy and of the spontaneous supercurrent, which for these two configurations is always a screening supercurrent, are given as functions of the total flux. A discontinuous transition between configurations occurs as a function of the flux.

Christine Ammann; Paul Erdös; Stephen B. Haley

1995-05-01T23:59:59.000Z

435

Test results of the US-LCT pool-boiling coils in the International Fusion Superconducting Magnet Test Facility (IFSMTF)  

SciTech Connect (OSTI)

The international Large Coil Task (LCT) has designed, built, and successfully tested six different toroidal field coils. Each has a 2.5- x 3.5-m D-shaped bore, a current between 10 and 18 kA, and is designed for stable operation at 8 T, with a superimposed pulsed field of 0.14 T in 1.0 s, and simulated nuclear heating. Included in the torus are two pool-boiling coils designed and fabricated by US firms, General Dynamics/Convair Division (GD) and General Electric/Oak Ridge National Laboratory (GE). Both coils were well instrumented for studies of electromagnetic, mechanical, and thermodynamic properties. Both coils performed well and met design specifications. In later ''extended-condition'' full-array tests beyond the design values, both operated stably at 100% design current and above 9 T, even with bath temperature higher than 4.3 K. The mechanical behavior of both coils was generally in good agreement with calculations. Both coils were also safely discharged several times in the extended-condition tests. All results indicate that the technology developed for these two pool-boiling LCT coils can be directly applied for future large-scale applications. 5 refs., 5 figs., 9 tabs.

Shen, S.S.; Dresner, L.; Lubell, M.S.; Lue, J.W.; Luton, J.N.; McManamy, T.J.; Wilson, C.T.; Wintenberg, R.E.

1987-01-01T23:59:59.000Z

436

Superconducting Topological Insulators  

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

Superconducting Topological Insulators Print Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be taken even further. Their studies showed that by doping the TI, bismuth selenide, with copper, it's possible to make the topologically ordered electrons superconducting, dropping electrical resistance in the surface states all the way to zero.

437

Superconducting Topological Insulators  

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

Superconducting Topological Insulators Print Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be taken even further. Their studies showed that by doping the TI, bismuth selenide, with copper, it's possible to make the topologically ordered electrons superconducting, dropping electrical resistance in the surface states all the way to zero.

438

Superconducting Topological Insulators  

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

Superconducting Topological Insulators Print Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be taken even further. Their studies showed that by doping the TI, bismuth selenide, with copper, it's possible to make the topologically ordered electrons superconducting, dropping electrical resistance in the surface states all the way to zero.

439

Test results of the U. S. -LCT pool-boiling coils in the International Fusion Superconducting Magnet Test Facility (IFSMTF)  

SciTech Connect (OSTI)

The international Large Coil Task (LCT) has designed, built, and successfully tested six different toroidal field coils. Each has a 2.5- x 3.5-m D-shaped bore, a current between 10 and 18 kA, and is designed for stable operation at 8 T with a superimposed pulsed field of 0.14 T in 1.0 s and simulated nuclear heating. Included in the torus are two pool-boiling coils designed and fabricated by U.S. firms, General Dynamics/Convair Division (GD) and General Electric/Oak Ridge National Laboratory (GE). Both coils were well instrumented for studies of electromagnetic, mechanical, and thermodynamic properties. Testing of the torus started early in 1986 and was successfully completed on September 3, 1987, although the pulsed field tests with GD and GE had to be deleted from the test program because it was not feasible to devote the required few months to repair the mechanism for moving the pulse coil system to these two test coils. Both coils performed well and met design specifications. In later ''extended-condition'' full-array tests beyond the design values, both operated stably at 100% design current and above 9 T, even with bath temperature higher than 4.3 K. The mechanical behaviour of both coils was generally in good agreement with calculations. Both coils were also safely discharged several times in the extended-condition tests. All results indicate that the technology developed for these two pool-boiling LT coils can be directly applied for future large-scale applications.

Shen, S.S.; Dresner, L.; Lubell, M.S.; Lue, J.W.; Luton, J.N.; McManamy, T.J.; Wilson, C.T.; Wintenberg, R.E.

1988-03-01T23:59:59.000Z

440

Oxygen-assisted room-temperature deposition of CoPt3 films with perpendicular magnetic anisotropy  

E-Print Network [OSTI]

Oxygen-assisted room-temperature deposition of CoPt3 films with perpendicular magnetic anisotropy B Jolla, California 92093 Received 23 July 2002; accepted 30 September 2002 Trace amounts of oxygen CoPt3 grown by vapor deposition at or slightly above room temperature. Oxygen is known to act

Hellman, Frances

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441

Zakharov-Kuznetsov equation in a magnetized plasma with two temperature superthermal electrons  

SciTech Connect (OSTI)

A nonlinear Zakharov-Kuznetsov (ZK) equation for ion-acoustic solitary waves (IASWs) in a magnetized plasmas containing kappa distributed cold and hot electrons is derived by using reductive perturbation method. From the solution of ZK equation, the characteristics of IASWs have been studied under the influence of various plasma parameters. Existence domain of physical parameters is determined. It has been observed that the present plasma system supports the existence of both positive as well as negative potential solitons. The combined effects of cold to hot electron temperature ratio (?), density ratio of cold electrons to ions (f), superthermality of cold and hot electrons (?{sub c},?{sub h}), strength of magnetic field (via ?{sub i}), and obliqueness (?) significantly influence the profile of IASWs. The physical parameters play a great role to modify the width and amplitude of the solitary structures. The stability analysis is also presented in this investigation and parametric range is determined to check the presence of stable and unstable solitons. The findings of this study are important to the physics of electrostatic wave structures in the Saturn's magnetosphere where two temperature electrons with kappa distribution exist.

Saini, N. S., E-mail: nssaini@yahoo.com; Chahal, B. S., E-mail: chahal-bs@rediffmail.com [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Bains, A. S., E-mail: bainsphysics@yahoo.co.in [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Shandong University at Weihai, 264209 Weihai (China); Bedi, C., E-mail: bedi-chanchal@yahoo.co.in [Department of Physics, Lyallpur Khalsa College, Jalandhar 144001 (India)

2014-02-15T23:59:59.000Z

442

Current-induced switching of magnetic tunnel junctions: Effects of field-like spin-transfer torque, pinned-layer magnetization orientation, and temperature  

SciTech Connect (OSTI)

We study current-induced switching in magnetic tunnel junctions in the presence of a field-like spin-transfer torque and titled pinned-layer magnetization in the high current limit at finite temperature. We consider both the Slonczewski and field-like torques with coefficients a{sub J} and b{sub J}, respectively. At finite temperatures, ?=b{sub J}/a{sub J}=±1 leads to a smaller mean switching time compared that with ?=0. The reduction of switching time in the presence of the field-like term is due to the alignment effect (for ?>0) and the initial torque effect.

Tiwari, R. K.; Jhon, M. H.; Ng, N.; Gan, C. K., E-mail: ganck@ihpc.a-star.edu.sg [Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, 16-16 Connexis, Singapore 138632 (Singapore); Srolovitz, D. J. [Department of Materials Science, Engineering, Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

2014-01-13T23:59:59.000Z

443

Processes yielding high superconducting temperatures  

SciTech Connect (OSTI)

It is pointed out that any microscopic description of the new high-T/sub c/ superconductors should take into account a number of important points concerning strong couplings, whatever their nature: absence of the MacMillan limit, absence of a Migdal theorem, and importance of the Brovman-Kagan type of vertices with different singularities depending on the dimensionality. As a consequence, the applicability of standard techniques such as the Eliashberg theory in particular, may be questioned in high-T/sub c/ superconductors.

Beal-Monod, M.T.

1987-12-01T23:59:59.000Z

444

Dissipative hydride precipitates in superconducting niobium cavities  

SciTech Connect (OSTI)

We report the first direct observation of the microstructural features exhibiting RF losses at high surface magnetic fields of above 100 mT in field emission free superconducting niobium cavities. The lossy areas were identified by advanced thermometry. Surface investigations using different techniques were carried out on cutout samples from lossy areas and showed the presence of dendritic niobium hydrides. This finding has possible implications to the mechanisms of RF losses in superconducting niobium at all field levels.

Romanenko, A.; Cooley, L.D.; /Fermilab; Ciovati, G.; / /Jefferson Lab; Wu, G.; /Argonne

2011-10-01T23:59:59.000Z

445

Low temperature London penetration depth and superfluid density in Fe-based superconductors  

SciTech Connect (OSTI)

The superconducting gap symmetry of the Fe-based superconductors was studied by measurements and analysis of London penetration depth and super uid density. Tunnel diode resonator technique for these measurements was implemented in a dilution refrigerator allowing for the temperatures down to 50 mK. For the analysis of the super uid density, we used both experimental studies of Al-coated samples and original thermodynamic approach based on Rutgers relation. In three systems studied, we found that the superconducting gap at the optimal doping is best described in multi-gap full gap scenario. By performing experiments on samples with arti#12;cially introduced disorder with heavy ion irradiation, we show that evolution of the superconducting transition temperature and of the super uid density are consistent with full-gap sign changing s#6; superconducting state. The superconducting gap develops strong modulation both in the under-doped and the over-doped regimes. In the terminal hole-doped KFe{sub 2}As{sub 2}, both temperature dependence of the super uid density and its evolution with increase of the scattering rate are consistent with symmetry imposed vertical line nodes in the superconducting gap. By comparative studies of hole-doped (Ba,K)Fe{sub 2}As{sub 2} and electron-doped Ca10-3-8, we show that the superconducting gap modulation in the under-doped regime is intrinsic and is not induced by the coexisting static magnetic order.

Kim, Hyunsoo [Ames Laboratory] [Ames Laboratory

2013-05-15T23:59:59.000Z

446

Friction domination with superconducting strings  

Science Journals Connector (OSTI)

We investigate the evolution of a superconducting string network with arbitrary, constant string current in the friction dominated regime. In the absence of an external magnetic field the network always reaches a scaling solution. However, for string current stronger than a critical value, it is different than the usual horizon scaling of the nonsuperconducting string case. In this case the friction domination era never ends. Whilst the superconducting string network can be much denser than usually assumed, it can never dominate the universe energy density. It can, however, influence the cosmic microwave background radiation and the formation of large scale structure. When embedded in a primordial magnetic field of sufficient strength, the network never reaches scaling and, thus, eventually dominates the universe evolution.

Konstantinos Dimopoulos and Anne-Christine Davis

1998-01-15T23:59:59.000Z

447

Superconducting technology program Sandia 1996 annual report  

SciTech Connect (OSTI)

Sandia`s Superconductivity Technology Program is a thallium-based high-temperature superconductor (HTS) research and development program consisting of efforts in powder synthesis and process development, open-system thick film conductor development, wire and tape fabrication, and HTS motor design. The objective of this work is to develop high-temperature superconducting conductors (wire and tape) capable of meeting requirements for high-power electrical devices of interest to industry. The research efforts currently underway are: (1) Process development and characterization of thallium-based high-temperature superconducting closed system wire and tape, (2) Investigation of the synthesis and processing of thallium-based thick films using two-zone processing, and (3) Cryogenic design of a 30K superconducting motor. This report outlines the research that has been performed during FY96 in each of these areas.

Roth, E.P.

1997-02-01T23:59:59.000Z

448

Superconductivity for electric power systems: Program overview  

SciTech Connect (OSTI)

Largely due to government and private industry partnerships, electric power applications based upon high-temperature superconductivity are now being designed and tested only seven years after the discovery of the high-temperature superconductors. These applications offer many benefits to the national electric system including: increased energy efficiency, reduced equipment size, reduced emissions, increased stability/reliability, deferred expansion, and flexible electricity dispatch/load management. All of these benefits have a common outcome: lower electricity costs and improved environmental quality. The U.S. Department of Energy (DOE) sponsors research and development through its Superconductivity Program for Electric Power Systems. This program will help develop the technology needed for U.S. industries to commercialize high-temperature superconductive electric power applications. DOE envisions that by 2010 the U.S. electric power systems equipment industry will regain a major share of the global market by offering superconducting products that outperform the competition.

Not Available

1995-02-01T23:59:59.000Z

449

Electronic structure of superconductivity refined  

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

Electronic structure of superconductivity refined Electronic structure of superconductivity refined Electronic structure of superconductivity refined A team of physicists propose a new model that expands on a little understood aspect of the electronic structure in high-temperature superconductors. July 10, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.

450

Ensure Continuous Power to Critical Industrial Processes with the New Superconducting Storage Device (SSD™)  

E-Print Network [OSTI]

Administration system. In that project a superconducling coil was used to provide energy to stabilizc a transmission line. Sl's focus on the benefits of superconducting magnetic energy storage Figure I. SI cryostat in an SSO trailer. 63 ESL-IE-92... capacity, While superconducting magnets have bcen used for over 10 years for magnetic resonance imaging, the only previous use of superconductivity for power systems has been a research project in the early eightjes on the Bonneville Power...

Dewinkel, C. C.; Koeppe, P. F.

451

Superconducting nano-layer coating without insulator  

E-Print Network [OSTI]

The superconducting nano-layer coating without insulator layer is studied. The magnetic-field distribution and the forces acting on a vortex are derived. Using the derived forces, the vortex-penetration field and the lower critical magnetic field can be discussed. The vortex-penetration field is identical with the multilayer coating, but the lower critical magnetic field is not. Forces acting on a vortex from the boundary of two superconductors play an important role in evaluations of the free energy.

Kubo, Takayuki

2014-01-01T23:59:59.000Z

452

National High Magnetic Field Laboratory - Magnets and Materials...  

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

Applied Superconductivity Center, please see the center's group members page. Magnet Science & Technology Group Members Senior Personnel Bai, Hongyu Research Faculty II Phone:...

453

Introduction to progress and promise of superconductivity for energy storage in the electric power sector  

SciTech Connect (OSTI)

Around the world, many groups conduct research, development and demonstration (RD and D) to make storage an economic option for the electric power sector. The progress and prospects for the application of superconductivity, with emphasis on high-temperature superconductivity, to the electric power sector has been the topic of an IEA Implementing Agreement, begun in 1990. The present Task members are Canada, Denmark, Finland, Germany, Israel, Italy, Japan, Korea, the Netherlands, Norway, Sweden, Switzerland, Turkey, the United Kingdom and the US. As a result of the Implementing Agreement, work has been done by the Operating Agent with the full participation of all the member countries. This work has facilitated the exchange of informtion among experts in all countries and has documented relevant assessments. Further, this work has reviewed the status of SMES and is now updating same, as well as investigating the progress on and prospects for flywheels with superconducting bearings. The Operating Agent and Task members find a substantially different set of opportunities for and alternatives to storage than was the case before the 1987 discovery of high-temperature superconductivity. Beside the need to level generation, there is also the need to level the load on transmission lines, increase transmission stability, and increase power quality. These needs could be addressed by high power storage that could be brought in and out of the grid in fractions of a second. Superconducting Magnetic Energy Storage and flywheels with superconducting bearings are devices that deserve continued RD and D because they promise to be the needed storage devices.

Wolsky, A.M.

1998-05-01T23:59:59.000Z

454

VLHC Meeting | Superconducting Magnet Division  

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

Workshop on the Effect of Synchrotron Radiation in the Very Large Hadron Workshop on the Effect of Synchrotron Radiation in the Very Large Hadron Collider (VLHC) September 18 - 20, 2000 The workshop was intended to be an initial investigation into the advantages and drawbacks of synchrotron radiation in a high field VLHC. We identified and clarified future topics for further investigation. Synchrotron radiation damping at very high proton beam energies can result in hitherto unobtainable beam densities which may prove beneficial in achieving machine performance goals. Radiated power will inevitably complicate the beam tube environment. Is there an appropriate balance at these energies? The workshop was one in a series looking at topics of potential interest to a next generation hadron machine organized by the VLHC Steering Committee.

455

Design of a horizontal test cryostat for superconducting RF cavities for the FREIA facility at Uppsala University  

SciTech Connect (OSTI)

Uppsala University is constructing a large scale facility, called FREIA (Facility for Research Instrumentation and Accelerator Development). FREIA includes a helium liquefier and an accelerator test facility and has the capacity to test superconducting radio-frequency (RF) cavities with the same RF system and RF power level as in an accelerator. A central element of FREIA is a horizontal test cryostat connected in closed loop to a helium liquefier. This cryostat can house two fully equipped (tuners, piezo, power coupler, helium tank) superconducting cavities to perform full RF high power tests and operate at temperatures between 1.8 K and 4.2 K. The cryostat is designed to accommodate a large array of superconducting cavities and magnets, among which the European Spallation Source (ESS) type spoke and high-? elliptical cavities as well as TESLA/ILC type elliptical cavities. The present status of the project and the design of the cryostat are reported.

Chevalier, N. R.; Thermeau, J.-P.; Bujard, P.; Junquera, T. [Accelerators and Cryogenic Systems (ACS), 86 rue de Paris, 91400 Orsay (France); Hermansson, L.; Kern, R. Santiago; Ruber, R. [Uppsala University, Department of Physics and Astronomy, 75120 Uppsala (Sweden)

2014-01-29T23:59:59.000Z

456

Magnetic order close to superconductivity in the iron-based layered LaO12xFxFeAs systems  

E-Print Network [OSTI]

that is suppressed by doping with electrons to induce superconductivity9 , there has been no direct evidence of SDW-axis spectrometer at the High Flux Isotope Reactor, Oak Ridge National Laboratory. Figure 1a shows the high, inset). This suggests that a structural phase transition has occurred. For comparison, we note

Chandra, Premi

457

Nuclear spin conversion of water inside fullerene cages detected by low-temperature nuclear magnetic resonance  

SciTech Connect (OSTI)

The water-endofullerene H{sub 2}O@C{sub 60} provides a unique chemical system in which freely rotating water molecules are confined inside homogeneous and symmetrical carbon cages. The spin conversion between the ortho and para species of the endohedral H{sub 2}O was studied in the solid phase by low-temperature nuclear magnetic resonance. The experimental data are consistent with a second-order kinetics, indicating a bimolecular spin conversion process. Numerical simulations suggest the simultaneous presence of a spin diffusion process allowing neighbouring ortho and para molecules to exchange their angular momenta. Cross-polarization experiments found no evidence that the spin conversion of the endohedral H{sub 2}O molecules is catalysed by {sup 13}C nuclei present in the cages.

Mamone, Salvatore, E-mail: s.mamone@soton.ac.uk; Concistrè, Maria; Carignani, Elisa; Meier, Benno; Krachmalnicoff, Andrea; Johannessen, Ole G.; Denning, Mark; Carravetta, Marina; Whitby, Richard J.; Levitt, Malcolm H., E-mail: mhl@soton.ac.uk [School of Chemistry, University of Southampton, Southampton SO17 1BJ (United Kingdom); Lei, Xuegong; Li, Yongjun [Department of Chemistry, Columbia University, New York, New York 10027 (United States)] [Department of Chemistry, Columbia University, New York, New York 10027 (United States); Goh, Kelvin; Horsewill, Anthony J. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)] [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

2014-05-21T23:59:59.000Z

458

Eighth International Magnetic Measurement Workshop (IMMW-8) presentations  

SciTech Connect (OSTI)

This report contains viewgraphs on magnetic field measurements conducted at the superconducting super collider and other accelerators.

NONE

1993-09-01T23:59:59.000Z

459

Magnetic property of a staggered-array undulator using a bulk high-temperature superconductor  

Science Journals Connector (OSTI)

The magnetic field of a staggered-array undulator using a bulk high-temperature superconductor is calculated by analytical and numerical methods. Analytical formulas for the undulator field and the solenoid field required to generate the undulator field are derived from a simple two-dimensional model. The analytical calculation shows the degree of dependence of these fields on the undulator parameters, the generation of a high undulator field proportional to the critical current density of the bulk superconductor, and the good tunability of the undulator field over a wide range of values. The numerical calculation is performed in a three-dimensional geometry by two methods: the center field and energy minimization methods. The latter treats the current distribution inside the bulk, whereas the former neglects it as a natural extension of the analytical model. The calculation also reveals the dependence of the fields on the undulator parameters arising from the current distribution. From the comparison with experimental results, we find that the latter method reproduces the experimental results well, which indicates the importance of the current distribution inside the bulk. Therefore, we derive a semiempirical formula for the required solenoid field by modifying the analytical formula using the numerical results so as to include the effect of the current distribution. The semiempirical formula reproduces the numerical result with an error of 3%. Finally, we estimate the magnetic performance of the undulator as an example of using the formulas and values presented in this paper. The estimation shows that an undulator field twice as large as that of the present in-vacuum undulator but with an equal period and gap can be obtained at a temperature of approximately 20–40 K, and that deflection parameters (K values) of 1 and 2 can be achieved with periods of 5 and 10 mm at approximately 4–20 K.

Ryota Kinjo; Kenta Mishima; Yong-Woon Choi; Mohamed Omer; Kyohei Yoshida; Hani Negm; Konstantin Torgasin; Marie Shibata; Kyohei Shimahashi; Hidekazu Imon; Kensuke Okumura; Motoharu Inukai; Heishun Zen; Toshiteru Kii; Kai Masuda; Kazunobu Nagasaki; Hideaki Ohgaki

2014-02-26T23:59:59.000Z</