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1

Fault Current Limiters (FCL) Fact Sheet | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

& Publications An Assessment of Fault Current Limiter Testing Requirements Superconductivity Program Overview Superconductivity for Electric Systems: 2008 Annual Peer Review...

2

Superconducting FCL using a combined inducted magnetic field trigger and shunt coil  

SciTech Connect

A single trigger/shunt coil is utilized for combined induced magnetic field triggering and shunt impedance. The single coil connected in parallel with the high temperature superconducting element, is designed to generate a circulating current in the parallel circuit during normal operation to aid triggering the high temperature superconducting element to quench in the event of a fault. The circulating current is generated by an induced voltage in the coil, when the system current flows through the high temperature superconducting element.

Tekletsadik, Kasegn D. (Rexford, NY)

2007-10-16T23:59:59.000Z

3

High Temperature Superconducting Matrix Fault Current Limiter: Proof-of-Concept Test Results  

Science Conference Proceedings (OSTI)

This report describes the design and proof-of-concept test results of a pre-prototype superconducting fault current limiter (FCL). The device employs SuperPower's Matrix Fault Current Limiter (MFCL) technology and BSCCO-2212 bulk material manufactured by Nexans SuperConductors' melt cast processing (MCP) technique. The MFCL technology is targeted to address fault current over-duty problems at the transmission voltage level of 138kV and higher. In addition to EPRI sponsorship, this $12M development progra...

2004-09-27T23:59:59.000Z

4

High temperature superconducting fault current limiter  

DOE Patents (OSTI)

A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

Hull, J.R.

1997-02-04T23:59:59.000Z

5

Pushing the Limits of RF Superconductivity Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Presentations Workshop Proceedings Suggested Reading Material on RF Superconductivity Workshop Dinner Accommodations Ground Transportation Access to...

6

Self field triggered superconducting fault current limiter  

DOE Patents (OSTI)

A superconducting fault current limiter array with a plurality of superconductor elements arranged in a meanding array having an even number of supconductors parallel to each other and arranged in a plane that is parallel to an odd number of the plurality of superconductors, where the odd number of supconductors are parallel to each other and arranged in a plane that is parallel to the even number of the plurality of superconductors, when viewed from a top view. The even number of superconductors are coupled at the upper end to the upper end of the odd number of superconductors. A plurality of lower shunt coils each coupled to the lower end of each of the even number of superconductors and a plurality of upper shunt coils each coupled to the upper end of each of the odd number of superconductors so as to generate a generally orthoganal uniform magnetic field during quenching using only the magenetic field generated by the superconductors.

Tekletsadik, Kasegn D. (Rexford, NY)

2008-02-19T23:59:59.000Z

7

Microsoft Word - FCL Testing Report Final.doc  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

An Assessment of Fault Current Limiter An Assessment of Fault Current Limiter Testing Requirements Prepared for U.S. Department of Energy Office of Electricity Delivery and Energy Reliability Prepared by Brian Marchionini and Ndeye K. Fall, Energetics Incorporated Michael "Mischa" Steurer, Florida State University February 2009 Energetics Incorporated i EXECUTIVE SUMMARY The U.S. Department of Energy's (DOE) Office of Electricity Delivery and Energy Reliability (OE) is conducting research and development (R&D) on next-generation electricity delivery equipment including fault current limiters (FCLs). Prototype FCL devices are undergoing testing with the aim of market-ready devices making their debut in the transmission and distribution (T&D) system in the next five years. As these

8

Definition: Fault Current Limiter | Open Energy Information  

Open Energy Info (EERE)

Limiter Limiter Jump to: navigation, search Dictionary.png Fault Current Limiter A fault current limiter prevents current in an electrical circuit from exceeding a predetermined level by increasing the electrical impedance of that circuit before the current through the circuit exceeds that level. Fault current limiters are designed so as to minimize the impedance of the circuit under normal conditions to reduce losses, but increase the impedance of the circuit under fault conditions to limit fault current.[1] View on Wikipedia Wikipedia Definition A Fault Current Limiter (FCL) is a device which limits the prospective fault current when a fault occurs (e.g. in a power transmission network). The term includes superconducting devices and non-superconducting devices, however some of the more simple non-superconducting devices (such

9

An Assessment of Fault Current Limiter Testing Requirements ...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Energy Reliability (OE) is conducting research and development (R&D) on next-generation electricity delivery equipment including fault current limiters (FCLs). Prototype FCL...

10

Superconducting matrix fault current limiter with current-driven trigger mechanism  

DOE Patents (OSTI)

A modular and scalable Matrix-type Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. An inductor is connected in series with the trigger superconductor in the trigger matrix and physically surrounds the superconductor. The current surge during a fault will generate a trigger magnetic field in the series inductor to cause fast and uniform quenching of the trigger superconductor to significantly reduce burnout risk due to superconductor material non-uniformity.

Yuan, Xing (Albany, NY)

2008-04-15T23:59:59.000Z

11

Program on Technology Innovation: Application of a High Temperature Superconducting Fault Current Limiter at AEP's Sporn Substation  

Science Conference Proceedings (OSTI)

This report describes the application of a Superconducting Fault Current Limiter (SFCL) to address fault current over-duty problems in American Electric Power's 138kV Sporn Substation. EPRI is current developing SFCL technology targeted to address fault current over-duty problems at the transmission voltage level of 138kV and higher. The technology under development is termed the Matrix Fault Current Limiter (MFCL) due to the modular nature arrangements of its High Temperature Superconducting (HTS) eleme...

2007-10-30T23:59:59.000Z

12

Proc. of the workshop on pushing the limits of RF superconductivity.  

Science Conference Proceedings (OSTI)

For three days in late September last year, some sixty experts in RF superconductivity from around the world came together at Argonne to discuss how to push the limits of RF superconductivity for particle accelerators. It was an intense workshop with in-depth presentations and ample discussions. There was added excitement due to the fact that, a few days before the workshop, the International Technology Recommendation Panel had decided in favor of superconducting technology for the International Linear Collider (ILC), the next major high-energy physics accelerator project. Superconducting RF technology is also important for other large accelerator projects that are either imminent or under active discussion at this time, such as the Rare Isotope Accelerator (RIA) for nuclear physics, energy recovery linacs (ERLs), and x-ray free-electron lasers. For these accelerators, the capability in maximum accelerating gradient and/or the Q value is essential to limit the length and/or operating cost of the accelerators. The technological progress of superconducting accelerators during the past two decades has been truly remarkable, both in low-frequency structures for acceleration of protons and ions as well as in high-frequency structures for electrons. The requirements of future accelerators demand an even higher level of performance. The topics of this workshop are therefore highly relevant and timely. The presentations given at the workshop contained authoritative reviews of the current state of the art as well as some original materials that previously had not been widely circulated. We therefore felt strongly that these materials should be put together in the form of a workshop proceeding. The outcome is this report, which consists of two parts: first, a collection of the scholarly papers prepared by some of the participants and second, copies of the viewgraphs of all presentations. The presentation viewgraphs, in full color, are also available from the Workshop Presentations link on the workshop's web page at http://www.aps.anl.gov/conferences/RFSCLimits/. I would like to thank all of the participants for their lively contributions to the workshop and to these proceedings, and Helen Edwards and Hasan Padamsee for their help in developing the workshop program. I also thank Cathy Eyberger, Kelly Jaje, and Renee Lanham for working very hard to take care of the administrative details, in particular Cathy for editing this report.

Kim, K-J., Eyberger, C., editors

2005-04-13T23:59:59.000Z

13

Solid-state circuit breaker with current limiting characteristic using a superconducting coil  

DOE Patents (OSTI)

A thyristor bridge interposes an ac source and a load. A series connected DC source and superconducting coil within the bridge biases the thyristors thereof so as to permit bidirectional ac current flow therethrough under normal operating conditions. Upon a fault condition a control circuit triggers the thyristors so as to reduce ac current flow therethrough to zero in less than two cycles and to open the bridge thereafter. Upon a temporary overload condition the control circuit triggers the thyristors so as to limit ac current flow therethrough to an acceptable level.

Boenig, Heinrich J. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

14

Solid-state circuit breaker with current-limiting characteristic using a superconducting coil  

DOE Patents (OSTI)

A thyristor bridge interposes an ac source and a load. A series connected DC source and superconducting coil within the bridge biases the thyristors thereof so as to permit bidirectional ac current flow therethrough under normal operating conditions. Upon a fault condition a control circuit triggers the thyristors so as to reduce ac current flow therethrough to zero in less than two eyeles and to open the bridge thereafter. Upon a temporary overload condition the control circuit triggers the thyristors so as to limit ac current flow therethrough to an acceptable level.

Boenig, H.J.

1982-08-16T23:59:59.000Z

15

Pushing the Gradient Limitations of Superconducting Photonic Band Gap Structure Cells  

SciTech Connect

Superconducting photonic band gap resonators present us with unique means to place higher order mode couples in an accelerating cavity and efficiently extract HOMs. An SRF PBG resonator with round rods was successfully tested at LANL demonstrating operation at 15 MV/m. Gradient in the SRF PBG resonator was limited by magnetic quench. To increase the quench threshold in PBG resonators one must design the new geometry with lower surface magnetic fields and preserve the resonator's effectiveness for HOM suppression. The main objective of this research is to push the limits for the high-gradient operation of SRF PBG cavities. A NCRF PBG cavity technology is established. The proof-of-principle operation of SRF PBG cavities is demonstrated. SRF PBG resonators are effective for outcoupling HOMs. PBG technology can significantly reduce the size of SRF accelerators and increase brightness for future FELs.

Simakov, Evgenya I. [Los Alamos National Laboratory; Haynes, William B. [Los Alamos National Laboratory; Kurennoy, Sergey S. [Los Alamos National Laboratory; Shchegolkov, Dmitry [Los Alamos National Laboratory; O'Hara, James F. [Los Alamos National Laboratory; Olivas, Eric R. [Los Alamos National Laboratory

2012-06-07T23:59:59.000Z

16

Design, Fabrication and Testing of a Superconducting Fault Current Limiter (SFCL)  

SciTech Connect

The purpose of this project was to conduct R&D on specified components and provide technical design support to a SuperPower team developing a high temperature superconducting Fault Current Limiter (SFCL). ORNL teamed with SuperPower, Inc. on a Superconductivity Partnerships with Industry (SPI) proposal for the SFCL that was submitted to DOE and approved in FY 2003. A contract between DOE and SuperPower, Inc. was signed on July 14, 2003 to design, fabricate and test the SFCL. This device employs high temperature superconducting (HTS) elements and SuperPower's proprietary technology. The program goal was to demonstrate a device that will address a broad range of the utility applications and meet utility industry requirements. This DOE-sponsored Superconductivity Partnership with Industry project would positively impact electric power transmission reliability and security by introducing a new element in the grid that can significantly mitigate fault currents and provide lower cost solutions for grid protection. The project will conduct R&D on specified components and provide technical design support to a SuperPower-led team developing a SFCL as detailed in tasks 1-5 below. Note the SuperPower scope over the broad SPI project is much larger than that shown below which indicates only the SuperPower tasks that are complementary to the ORNL tasks. SuperPower is the Project Manager for the SFCL program, and is responsible for completion of the project on schedule and budget. The scope of work for ORNL is to provide R&D support for the SFCL in the following four broad areas: (1) Assist with high voltage subsystem R&D, design, fabrication and testing including characterization of the general dielectric performance of LN2 and component materials; (2) Consult on cryogenic subsystem R&D, design, fabrication and testing; (3) Participate in project conceptual and detailed design reviews; and (4) Guide commercialization by participation on the Technical Advisory Board (TAB). SuperPower's in-kind work for the SFCL will be provided in the following areas: (1) Work with ORNL to develop suitable test platforms for the evaluation of subsystems and components; (2) Provide cryogenic and high voltage subsystem designs for evaluation; (3) Lead the development of the test plans associated with the subsystem and components and participate in test programs at ORNL; and (4) Based on the test results, finalize the subsystem and component designs and incorporate into the respective SFCL prototypes.

Gouge, M..; Schwenterly, S.W.; Hazelton, D. (SuperPower, Inc.)

2011-06-15T23:59:59.000Z

17

Fault-Current Limiter (FCL) Application in a Wind Power Plant (Poster)  

DOE Green Energy (OSTI)

This poster describes how the power system switchgear and power system protection for WPPs should be carefully designed to be compatible with the operation of conventional synchronous generators connected to the same grid.

Muljadi, E.; Gevorgian, V.

2011-05-01T23:59:59.000Z

18

Enhancement of power system transient stability using superconducting fault current limiters  

E-Print Network (OSTI)

Abstract|Transient stability investigations consist in studying the rotor oscillations of generators (electro-mechanic oscillations, 0.1-2 Hz) followed by a fault of large amplitude, e.g. short circuit. The goal is to indicate if the generators are capable to stay synchronous after a fault has occurred. The fault duration is one of the most important factors to be given an answer. In fact, the shorter the fault, the more the maintaining of synchronisation can be guaranteed. Now in case of a fault, a fault current limiter has an extremely fast current transition in comparison with electro-mechanic time constants. This implies a quasi-instantaneous elimination of the fault through a limitation of the current and consequently a better ability to maintain the synchronisation of the system. We recall, in a classic system the elimination of a fault, by opening a circuit breaker, is carried out in two or three cycles in the best case. We have here studied a simple, radial electric network con guration with a machine and an in nite network. The study covers simulations of di erent faults that can occur in a network and the consequences of the recovery time of the fault current limiter. I.

Marten Sjostrom; Rachid Cherkaoui

1999-01-01T23:59:59.000Z

19

Quantum-limited detection of millimeter waves using superconducting tunnel junctions  

SciTech Connect

The quasiparticle tunneling current in a superconductor-insulator- superconductor (SIS) tunnel junction is highly nonlinear. Such a nonlinearity can be used to mix two millimeter wave signals to produce a signal at a much lower intermediate frequency. We have constructed several millimeter and sub-millimeter wave SIS mixers in order to study high frequency response of the quasiparticle tunneling current and the physics of high frequency mixing. We have made the first measurement of the out-of-phase tunneling currents in an SIS tunnel junction. We have developed a method that allows us to determine the parameters of the high frequency embedding circuit by studying the details of the pumped I-V curve. We have constructed a 80--110 GHz waveguide-based mixer test apparatus that allows us to accurately measure the gain and added noise of the SIS mixer under test. Using extremely high quality tunnel junctions, we have measured an added mixer noise of 0.61 {plus_minus} 0.36 quanta, which is within 25 percent of the quantum limit imposed by the Heisenberg uncertainty principle. This measured performance is in excellent agreement with that predicted by Tucker`s theory of quantum mixing. We have also studied quasioptically coupled millimeter- and submillimeter-wave mixers using several types of integrated tuning elements. 83 refs.

Mears, C.A.

1991-09-01T23:59:59.000Z

20

Quantum-limited detection of millimeter waves using superconducting tunnel junctions  

SciTech Connect

The quasiparticle tunneling current in a superconductor-insulator- superconductor (SIS) tunnel junction is highly nonlinear. Such a nonlinearity can be used to mix two millimeter wave signals to produce a signal at a much lower intermediate frequency. We have constructed several millimeter and sub-millimeter wave SIS mixers in order to study high frequency response of the quasiparticle tunneling current and the physics of high frequency mixing. We have made the first measurement of the out-of-phase tunneling currents in an SIS tunnel junction. We have developed a method that allows us to determine the parameters of the high frequency embedding circuit by studying the details of the pumped I-V curve. We have constructed a 80--110 GHz waveguide-based mixer test apparatus that allows us to accurately measure the gain and added noise of the SIS mixer under test. Using extremely high quality tunnel junctions, we have measured an added mixer noise of 0.61 {plus minus} 0.36 quanta, which is within 25 percent of the quantum limit imposed by the Heisenberg uncertainty principle. This measured performance is in excellent agreement with that predicted by Tucker's theory of quantum mixing. We have also studied quasioptically coupled millimeter- and submillimeter-wave mixers using several types of integrated tuning elements. 83 refs.

Mears, C.A.

1991-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Superconductivity Program Overview High-Temperature Superconductivity  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

22

Limiter  

DOE Patents (OSTI)

A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

1984-10-19T23:59:59.000Z

23

Limiter  

SciTech Connect

A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

Cohen, Samuel A. (Hopewell, NJ); Hosea, Joel C. (Princeton, NJ); Timberlake, John R. (Allentown, NJ)

1986-01-01T23:59:59.000Z

24

DEPOSITION OF NIOBIUM AND OTHER SUPERCONDUCTING MATERIALS WITH HIGH POWER IMPULSE MAGNETRON SPUTTERING: CONCEPT AND FIRST RESULTS  

E-Print Network (OSTI)

Workshop on RF Superconductivity, DESY, Hamburg, Germany,Gennaro, Physica C: Superconductivity 441 (2006) 130. [10]the Limits of RF Superconductivity, Padua, Italy, 2010. [12

Anders, Andre

2013-01-01T23:59:59.000Z

25

Superconducting wires  

SciTech Connect

The requirement of high critical current density has prompted extensive research on ceramic processing of high-T/sub c/ superconductors. An overview of wire fabrication techniques and the limitations they impose on component design will be presented. The effects of processing on microstructure and critical current density will also be discussed. Particle alignment has been observed in extruded samples which is attributed to high shear stresses during plastic forming. Composites of superconductor and silver in several configurations have been made with little deleterious effect on the superconducting properties. 35 refs., 2 figs., 1 tab.

Lanagan, M.T.; Poeppel, R.B.; Singh, J.P.; Dos Santos, D.I.; Lumpp, J.K.; Dusek, J.T.; Goretta, K.C.

1988-06-01T23:59:59.000Z

26

Superconducting wire  

DOE Patents (OSTI)

This invention consists of a method of producing superconducting wire by drawing a glass fiber with a melted powder of a superconducting wire inside the glass tube. After drawing, the glass fiber is heated to crystallize the superconducting compound. The diameter of the superconducting wires is controlled by the rate at which the glass fiber s are drawn from the glass tube.

Day, D.E.; Petrovic, J.J.; Gac, F.D.; Ray, C.S.

1991-03-05T23:59:59.000Z

27

Design, Test and Demonstration of Saturable Reactor High-Temperature Superconductor Fault Current Limiters  

Science Conference Proceedings (OSTI)

Zenergy Power has successfully designed, built, tested, and installed in the US electrical grid a saturable reactor Fault Current Limiter. Beginning in 2007, first as SC Power Systems and from 2008 as Zenergy Power, Inc., ZP used DOE matching grant and ARRA funds to help refine the design of the saturated reactor fault current limiter. ZP ultimately perfected the design of the saturated reactor FCL to the point that ZP could reliably design a suitable FCL for most utility applications. Beginning with a very basic FCL design using 1G HTS for a coil housed in a LN2 cryostat for the DC bias magnet, the technology progressed to a commercial system that was offered for sale internationally. Substantial progress was made in two areas. First, the cryogenics cooling system progressed from a sub-cooled liquid nitrogen container housing the HTS coils to cryostats utilizing dry conduction cooling and reaching temperatures down to less than 20 degrees K. Large, round cryostats with â??warm boreâ? diameters of 1.7 meters enabled the design of large tanks to hold the AC components. Second, the design of the AC part of the FCL was refined from a six legged â??spiderâ? design to a more compact and lighter design with better fault current limiting capability. Further refinement of the flux path and core shape led to an efficient saturated reactor design requiring less Ampere-turns to saturate the core. In conclusion, the development of the saturable reactor FCL led to a more efficient design not requiring HTS magnets and their associated peripheral equipment, which yielded a more economical product in line with the electric utility industry expectations. The original goal for the DOE funding of the ZP project â??Design, Test and Demonstration of Saturable Reactor High-Temperature Superconductor Fault Current Limitersâ? was to stimulate the HTS wire industry with, first 1G, then 2G, HTS wire applications. Over the approximately 5 years of ZPâ??s product development program, the amount of HTS wire employed per FCL and its cost as a percentage of the total FCL product content had not dropped substantially from an unsustainable level of more than 50% of the total cost of the FCL, nor had the availability increased (today the availability of 2G wire for commercial applications outside of specific partnerships with the leading 2G wire manufacturers is extremely limited). ZP had projected a very significant commercial potential for FCLs with higher performance and lower costs compared to the initial models built with 1G wire, which would come about from the widespread availability of low-cost, high-performance 2G HTS wire. The potential for 2G wires at greatly reduced performance-based prices compared to 1G HTS conductor held out the potential for the commercial production of FCLs at price and performance levels attractive to the utility industry. However, the price of HTS wire did not drop as expected and today the available quantities of 2G wire are limited, and the price is higher than the currently available supplies of 1G wire. The commercial option for ZP to provide a reliable and reasonably priced FCL to the utility industry is to employ conventional resistive conductor DC electromagnets to bias the FCL. Since the premise of the original funding was to stimulate the HTS wire industry and ZP concluded that copper-based magnets were more economical for the foreseeable future, DOE and ZP decided to mutually terminate the project.

Frank Darmann; Robert Lombaerde; Franco Moriconi; Albert Nelson

2011-10-31T23:59:59.000Z

28

Superconductive wire  

DOE Patents (OSTI)

A superconductive article is made by inserting a rigid mandrel into an internal cavity of a first metallic tube, said tube having an interior surface and an exterior surface, said interior surface defining the interior cavity, forming a layer of a superconductive material or superconductive precursor upon the exterior surface of said first metallic tube, machining the layer of superconductive material or superconductive precursor to a predetermined diameter to form an intermediate article configured for insertion into a second metallic tube having an interior diameter corresponding to the predetermined diameter, inserting the machined intermediate article into a second metallic tube having an internal diameter corresponding to the predetermined diameter of the intermediate article to form a composite intermediate article, reducing or ironing the composite intermediate article to a predetermined cross-sectional diameter, and sintering the reduced or ironed composite intermediate article at temperatures and for time sufficient for the superconductive material or superconductive precursor to exhibit superconductivity.

Korzekwa, David A. (Los Alamos, NM); Bingert, John F. (Jemez Springs, NM); Peterson, Dean E. (Los Alamos, NM); Sheinberg, Haskell (Santa Fe, NM)

1995-01-01T23:59:59.000Z

29

Superconductive wire  

DOE Patents (OSTI)

This invention is comprised of a superconductive article including a first metallic tube having an interior surface and an exterior surface, said interior surface defining an interior hollow cavity, a layer of superconductive material surrounding said exterior surface of said first metallic tube, and, a second metallic tube having an interior surface and an exterior surface, said interior surface adjacent to said layer of superconductive material is provided together with processes of making such a superconductive article including, e.g., inserting a rigid mandrel into an internal cavity of a first metallic tube, said tube having an interior surface and an exterior surface, said interior surface defining the interior cavity, forming a layer of a superconductive material or superconductive precursor upon the exterior surface of said first metallic tube, machining the layer of superconductive material or superconductive precursor to a predetermined diameter to form an intermediate article configured for insertion into a second metallic tube having an interior diameter corresponding to the predetermined diameter, inserting the machined intermediate article into a second metallic tube having an internal diameter corresponding to the predetermined diameter of the intermediate article to form a composite intermediate article, reducing and/or ironing the composite intermediate article to a predetermined cross-sectional diameter, and sintering the reduced or ironed composite intermediate article at temperatures and for time sufficient for the superconductive material or superconductive precursor to exhibit superconductivity.

Korzekwa, D.A.; Bingert, J.F.; Peterson, D.E.; Sheinberg, H.

1992-12-31T23:59:59.000Z

30

Superconducting phase qubits  

E-Print Network (OSTI)

eld enhancement of superconductivity in ultranarrow wires.computation · Qubits · Superconductivity · Decoherence PACS

Martinis, John M.

2009-01-01T23:59:59.000Z

31

Supersymmetric color superconductivity  

E-Print Network (OSTI)

Supersymmetric Color Superconductivity 1 arXiv:hep-patterns such as color superconductivity and color-?avortional method in color superconductivity, namely µ ? ?. In

Harnik, Roni; Larson, Daniel T.; Murayama, Hitoshi

2003-01-01T23:59:59.000Z

32

Superconductive articles  

DOE Patents (OSTI)

An article of manufacture including a substrate, a patterned interlayer of magnesium oxide, barium-titanium oxide or barium-zirconium oxide, the patterned interlayer material overcoated with a secondary interlayer material of yttria-stabilized zirconia or magnesium-aluminum oxide, upon the surface of the substrate whereby an intermediate article with an exposed surface of both the overcoated patterned interlayer and the substrate is formed, a coating of a buffer layer selected from the group consisting of oxides of Ce, Y, Cm, Dy, Er, Eu, Fe, Gd, Ho, In, La, Mn, Lu, Nd, Pr, Pu, Sm, Tb, Tl, Tm, Y, and Yb over the entire exposed surface of the intermediate article, and, a ceramic superconductive material layer as an overcoat upon the buffer layer whereby the ceramic superconductive material situated directly above the substrate has a crystal structure substantially different than the ceramic superconductive material situated above the overcoated patterned interlayer.

Wu, X.D.; Muenchausen, R.E.

1991-12-31T23:59:59.000Z

33

Superconducting cyclotrons  

SciTech Connect

Superconducting cyclotrons are particularly appropriate for acceleration of heavy ions. A review is given of design features of a superconducting cyclotron with energy 440 (Q$sup 2$/A) MeV. A strong magnetic field (4.6 tesla average) leads to small physical size (extraction radius 65 cm) and low construction costs. Operating costs are also low. The design is based on established technology (from present cyclotrons and from large bubble chambers). Two laboratories (in Chalk River, Canada and in East Lansing, Michigan) are proceeding with construction of full-scale prototype components for such cyclotrons.

Blosser, H.G.; Johnson, D.A.; Burleigh, R.J.

1976-01-01T23:59:59.000Z

34

Superconducting Power Equipment  

Science Conference Proceedings (OSTI)

The 2010 Electric Power Research Institute (EPRI) Technology Watch (Techwatch) report on superconducting power applications (EPRI report 1019995, Superconducting Power Equipment: Technology Watch 2010) introduced coverage about superconducting magnetic energy storage systems and superconducting transformers. The 2011 report contains additional information about superconducting power equipment, including progress to demonstrations in some projects. The 2011 report also includes a section on superconductin...

2011-12-22T23:59:59.000Z

35

Superconductivity Conference Held  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconductivity Conference Held Z.-X. Shen SSRL sponsored a major international conference on superconductivity early this year. The conference, entitled "Spectroscopies in Novel...

36

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network (OSTI)

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

Hassenzahl, W.

2011-01-01T23:59:59.000Z

37

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network (OSTI)

Scale Superconducting Magnetic Energy Storage Plant", IEEEfor SlIperconducting Magnetic Energy Storage Unit", inSuperconducting Magnetic Energy Storage Plant, Advances in

Hassenzahl, W.

2011-01-01T23:59:59.000Z

38

Some aspects of color superconductivity: an introduction  

E-Print Network (OSTI)

A pedagogical introduction to color superconductivity in the weak coupling limit is given. The focus is on the basic tools of thermal field theory necessary to compute observables of color superconductivity. The rich symmetry structure and symmetry breaking patterns are analyzed on the basis of the Anderson-Higgs mechanism. Some techniques can also be applied for computing neutrino processes in compact stars. As an example, we show how to obtain the neutrino emissivity for Urca processes in neutron stars by computing the polarization tensor of the W-boson. We also illustrate how a spin-1 color superconducting phase generates an anisotropic neutrino emissions in compact stars.

Qun Wang

2009-12-13T23:59:59.000Z

39

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

40

Secrets of superconductivity revealed  

NLE Websites -- All DOE Office Websites (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

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Secrets of superconductivity revealed  

NLE Websites -- All DOE Office Websites (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

42

Superconducting microfabricated ion traps  

E-Print Network (OSTI)

We fabricate superconducting ion traps with niobium and niobium nitride and trap single [superscript 88]Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the ...

Wang, Shannon Xuanyue

43

Boron: Modeling, Superconductivity  

Science Conference Proceedings (OSTI)

Oct 8, 2012 ... Boron, Boron Compounds, and Boron Nanomaterials: Structure, Properties, Processing and Applications: Boron: Modeling, Superconductivity

44

High Temperature Superconductivity Partners | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High Temperature Superconductivity Partners High Temperature Superconductivity Partners Map showing DOE's partnersstakeholders in the High Temperature Superconductivity Program...

45

Basic principle of superconductivity  

E-Print Network (OSTI)

The basic principle of superconductivity is suggested in this paper. There have been two vital wrong suggestions on the basic principle, one is the relation between superconductivity and the Bose-Einstein condensation (BEC), and another is the relation between superconductivity and pseudogap.

Tian De Cao

2007-08-23T23:59:59.000Z

46

Processing method for superconducting ceramics  

DOE Patents (OSTI)

A process for preparing a superconducting ceramic and particularly YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}, where {delta} is in the order of about 0.1--0.4, is carried out using a polymeric binder which decomposes below its ignition point to reduce carbon residue between the grains of the sintered ceramic and a nonhydroxylic organic solvent to limit the problems with water or certain alcohols on the ceramic composition.

Bloom, I.D.; Poeppel, R.B.; Flandermeyer, B.K.

1990-05-07T23:59:59.000Z

47

Superconductivity, Superfluidity and Holography  

E-Print Network (OSTI)

This is a concise review of holographic superconductors and superfluids. We highlight some predictions of the holographic models and the emphasis is given to physical aspects rather than to the technical details, although some references to understand the latter are systematically provided. We include gapped systems in the discussion, motivated by the physics of high-temperature superconductivity. In order to do so we consider a compactified extra dimension (with radius R), or, alternatively, a dilatonic field. The first setup can also be used to model cylindrical superconductors; when these are probed by an axial magnetic field a universal property of holography emerges: while for large R (compared to the other scales in the problem) non-local operators are suppressed, leading to the so called Little-Parks periodicity, the opposite limit shows non-local effects, e.g. the uplifting of the Little-Parks periodicity. This difference corresponds in the gravity side to a Hawking-Page phase transition.

Alberto Salvio

2013-01-02T23:59:59.000Z

48

Superconducting microfabricated ion traps  

E-Print Network (OSTI)

We fabricate superconducting ion traps with niobium and niobium nitride and trap single 88Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the resistance and critical current using a 4-wire measurement on the trap structure, and observing change in the rf reflection. The lowest observed heating rate is 2.1(3) quanta/sec at 800 kHz at 6 K and shows no significant change across the superconducting transition, suggesting that anomalous heating is primarily caused by noise sources on the surface. This demonstration of superconducting ion traps opens up possibilities for integrating trapped ions and molecular ions with superconducting devices.

Shannon X. Wang; Yufei Ge; Jaroslaw Labaziewicz; Eric Dauler; Karl Berggren; Isaac L. Chuang

2010-10-28T23:59:59.000Z

49

Nano-fabricated superconducting radio-frequency composites, method for producing nano-fabricated superconducting rf composites  

DOE Patents (OSTI)

Superconducting rf is limited by a wide range of failure mechanisms inherent in the typical manufacture methods. This invention provides a method for fabricating superconducting rf structures comprising coating the structures with single atomic-layer thick films of alternating chemical composition. Also provided is a cavity defining the invented laminate structure.

Norem, James H.; Pellin, Michael J.

2013-06-11T23:59:59.000Z

50

Superconductive radiofrequency window assembly  

DOE Patents (OSTI)

The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The SRF window assembly has a superconducting metal-ceramic design. The SRF window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the SRF window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

Phillips, H.L.; Elliott, T.S.

1998-05-19T23:59:59.000Z

51

Superconducting radiofrequency window assembly  

DOE Patents (OSTI)

The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly has a superconducting metal-ceramic design. The srf window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

Phillips, H.L.; Elliott, T.S.

1997-03-11T23:59:59.000Z

52

Superconducting Power Cables  

Science Conference Proceedings (OSTI)

Power cables constructed from superconducting materials are being realized in utility demonstrations within the United States. Cooled by liquid nitrogen, high temperature superconducting power cables can transfer large amounts of power through relatively small cross sections. The key to their high power capacity is the high current density inherent with superconductors; a superconducting wire can conduct several times as much current as copper or aluminum conductors of the same cross section. For the pas...

2006-11-30T23:59:59.000Z

53

Superconducting Power Cables  

Science Conference Proceedings (OSTI)

This report is a continuation of a Technology Watch series on superconducting power cables that summarize full-scale superconducting cable projects throughout the world ranging from full-scale test installations to utility demonstration projects. The report covers various aspects of each project from design to implementation. When available, updated status regarding operation and maintenance (O&M) also is presented. The report will serve as a knowledge resource on the status of superconducting cable tech...

2008-12-19T23:59:59.000Z

54

Superconductive interconnections for cryoelectronics  

Science Conference Proceedings (OSTI)

Factors affecting the use of superconducting interconnections for cryoelectronics will be examined. The fundamental questions to be answered are why interconnections are important for high performance computing

Kenneth Rose

1992-01-01T23:59:59.000Z

55

Superconducting VAR control  

DOE Patents (OSTI)

Static VAR control means employing an asymmetrically controlled Graetz bridge and a superconducting direct current coil having low losses and low cost characteristics.

Boenig, Heinrich J. (Los Alamos, NM); Hassenzahl, William V. (Piedmont, CA)

1982-01-01T23:59:59.000Z

56

Superconductive imaging surface magnetometer  

DOE Patents (OSTI)

An improved pick-up coil system for use with Superconducting Quantum Interference Device gradiometers and magnetometers involving the use of superconducting plates near conventional pick-up coil arrangements to provide imaging of nearby dipole sources and to deflect environmental magnetic noise away from the pick-up coils. This allows the practice of gradiometry and magnetometry in magnetically unshielded environments. One embodiment uses a hemispherically shaped superconducting plate with interior pick-up coils, allowing brain wave measurements to be made on human patients. another embodiment using flat superconducting plates could be used in non-destructive evaluation of materials.

Overton, Jr., William C. (Los Alamos, NM); van Hulsteyn, David B. (Santa Fe, NM); Flynn, Edward R. (Los Alamos, NM)

1991-01-01T23:59:59.000Z

57

Superconducting phase qubits  

Science Conference Proceedings (OSTI)

Experimental progress is reviewed for superconducting phase qubit research at the University of California, Santa Barbara. The phase qubit has a potential advantage of scalability, based on the low impedance of the device and the ability to microfabricate ... Keywords: 03.65.Yz, 03.67.Lx, 85.25.Cp, Decoherence, Quantum computation, Qubits, Superconductivity

John M. Martinis

2009-06-01T23:59:59.000Z

58

Superconducting thermoelectric generator  

DOE Patents (OSTI)

This invention is comprised of 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 higher thermal conductivity than that of the superconducting material. 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.

1992-12-31T23:59:59.000Z

59

The TESLA superconducting linear collider  

Science Conference Proceedings (OSTI)

This paper summarizes the present status of the studies for a superconducting Linear Collider (TESLA).

R. Brinkmann; the TESLA Collaboration

1997-01-01T23:59:59.000Z

60

Superconducting materials for large scale applications  

E-Print Network (OSTI)

IEEE Trans. Applied Superconductivity, vol. 12, pp.4. “Power Applications of Superconductivity,” in Handbookof Applied Superconductivity, B. Seeber, ed. , Bristol, UK:

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

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

6.763 Applied Superconductivity, Fall 2001  

E-Print Network (OSTI)

Phenomenological approach to superconductivity, with emphasis on superconducting electronics. Electrodynamics of superconductors, London's model, and flux quantization. Josephson Junctions and superconducting quantum ...

Orlando, Terry P.

62

Introduction to Color Superconductivity  

E-Print Network (OSTI)

At high nuclear density and small temperature, due to the asymptotic freedom property of Quantum ChromoDynamics and to the existence of an attractive channel in the color interaction, diquark condensates might be formed. Since these condensates break the color gauge symmetry, this phenomenon has the name of color superconductivity. In the last few years this has become a very active field of research. While a direct experimental test is still missing, color superconductivity might have implications in astrophysics because for some compact stars, e.g. pulsars, the baryon densities necessary for color superconductivity can probably be reached.

G. Nardulli

2006-10-23T23:59:59.000Z

63

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

64

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

65

Experimental work on superconductivity  

Science Conference Proceedings (OSTI)

The high thermal conductivity in the superconductive state at low reduced critical temperatures has been used for the detection of metal imperfections, including those caused by radiation damage. A statistically disordered single crystal of Ta with 30% ...

K. Mendelssohn

1962-01-01T23:59:59.000Z

66

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

67

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

68

Alexei Abrikosov and Superconductivity  

NLE Websites -- All DOE Office Websites (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.

69

Superconducting Power Cables  

Science Conference Proceedings (OSTI)

This report is the fourth installment of a Technology Watch series on Superconducting Power Cables that summarize full-scale superconducting cable projects throughout the world. The series provides an overview of technical fundamentals and status updates on ongoing development efforts ranging from full-scale test installations to grid-deployed demonstration projects. This installment of the series covers ongoing full-scale utility installations and proposed demonstration projects worldwide. Information a...

2009-12-23T23:59:59.000Z

70

New Superconducting Materials  

Science Conference Proceedings (OSTI)

Superconductors with higher superconducting transition temperatures, higher critical currents, and better mechanical properties would be valuable. This report presents criteria to guide the search for higher transition temperature materials. To determine if candidate materials are suitably metallic, the study carried out detailed electronic structure calculations. These calculations identified boron-containing hydrides as particularly promising as a new class of possible superconducting materials that ma...

1994-11-04T23:59:59.000Z

71

Superconducting transmission line particle detector  

DOE Patents (OSTI)

A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non- superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propagating in a superconducting transmission line are used to resolve N/sup 2/ ambiguity of charged particle events. 6 figs.

Gray, K.E.

1988-07-28T23:59:59.000Z

72

Superconducting transmission line particle detector  

DOE Patents (OSTI)

A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non-superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propogating in a superconducting transmission line are used to resolve N.sup.2 ambiguity of charged particle events.

Gray, Kenneth E. (Naperville, IL)

1989-01-01T23:59:59.000Z

73

Superconducting radiofrequency window assembly  

DOE Patents (OSTI)

The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

Phillips, Harry L. (Seaford, VA); Elliott, Thomas S. (Yorktown, VA)

1997-01-01T23:59:59.000Z

74

Superconductive radiofrequency window assembly  

DOE Patents (OSTI)

The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

Phillips, Harry Lawrence (Seaford, VA); Elliott, Thomas S. (Yorktown, VA)

1998-01-01T23:59:59.000Z

75

High temperature interfacial superconductivity  

DOE Patents (OSTI)

High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La.sub.2CuO.sub.4) and a metal (La.sub.1-xSr.sub.xCuO.sub.4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, T.sub.c may be either .about.15 K or .about.30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, T.sub.c exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high T.sub.c phases and to significantly enhance superconducting properties in other superconductors. The superconducting interface may be implemented, for example, in SIS tunnel junctions or a SuFET.

Bozovic, Ivan (Mount Sinai, NY); Logvenov, Gennady (Port Jefferson Station, NY); Gozar, Adrian Mihai (Port Jefferson, NY)

2012-06-19T23:59:59.000Z

76

DOE Superconductivity Program Stakeholders | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Stakeholders Map showing the stakeholders involved in High Temperature Superconductivity work with the DOE. DOE Superconductivity Program Stakeholders More Documents &...

77

Relativistic mechanism of superconductivity  

E-Print Network (OSTI)

According to the theory of relativity, the relativistic Coulomb's force between an electron pair is composed of two parts, the main part is repulsive, while the rest part can be attractive in certain situations. Thus the relativistic attraction of an electron pair provides an insight into the mechanism of superconductivity. In superconductor, there are, probably at least, two kinds of collective motions which can eliminate the repulsion between two electrons and let the attraction being dominant, the first is the combination of lattice and electron gas, accounting for traditional superconductivity; the second is the electron gas themselves, accounting for high $T_c$ superconductivity. In usual materials, there is a good balance between the repulsion and attraction of an electron pair, the electrons are regarded as free electrons so that Fermi gas theory plays very well. But in some materials, when the repulsion dominates electron pairs, the electron gas will has a behavior opposite to superconductivity. In the present paper the superconducting states are discussed in terms of relativistic quantum theory in details, some significant results are obtained including quantized magnetic flux, London equation, Meissner effect and Josephson effect.

H. Y. Cui

2002-12-17T23:59:59.000Z

78

Fluorinated Precursors of Superconducting Ceramics ...  

Fluorinated precursors for superconducting ceramics typically increase the critical current in the ... Applications and Industries. High-temperature ...

79

Argonne TDC: Superconductive Components, Inc.  

Unlocking the Potential of High-Temperature Superconductors . Superconductive Components, Inc. Columbus, Ohio. For bulk applications of high-temperature ...

80

Argonne TDC: Superconductive Components, Inc.  

High-Performance Tailored Materials for Levitation Permanent Magnet Technologies Making materials to help advance flywheel energy storage. Superconductive Components ...

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Possibility of color magnetic superconductivity  

E-Print Network (OSTI)

Two aspects of quark matter at high density are addressed: one is color superconductivity and the other is ferromagnetism. We are mainly concerned with the latter and its relation to color superconductivity, which we call "color magnetic superconductivity". The relation of ferromagnetism and chiral symmetry restoration is also discussed.

Toshitaka Tatsumi; Tomoyuki Maruyama; Eiji Nakano

2003-12-26T23:59:59.000Z

82

Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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)

83

LANL: Superconductivity Technology Center  

NLE Websites -- All DOE Office Websites (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).

84

Orbit Spaces in Superconductivity  

E-Print Network (OSTI)

In the framework of Landau theory of phase transitions one is interested to describe all the possible low symmetry ``superconducting'' phases allowed for a given superconductor crystal and to determine the conditions under which this crystal undergoes a phase transition. These problems are best described and analyzed in the orbit space of the high symmetry group of the ``normal, non-superconducting'' phase of the crystal. In this article it is worked out a simple example concerning superconductivity, that shows the P-matrix method to determine the equations and inequalities defining the orbit space and its stratification. This approach is of general validity and can be used in all physical problems that make use of invariant functions, as long as the symmetry group is compact.

Vittorino Talamini

2006-07-30T23:59:59.000Z

85

Superconducting active impedance converter  

DOE Patents (OSTI)

This invention is comprised of 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, D.S.; Hietala, V.M.; Martens, J.S.

1992-12-31T23:59:59.000Z

86

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

E-Print Network (OSTI)

B. Superconductivity . . . . . . . . . . . . . . . . .IV Superconductivity and Magnetism in Iron-PnictideSearch for Pressure Induced Superconductivity in Undoped Ce-

Zocco, Diego Andrés

2011-01-01T23:59:59.000Z

87

Models of Holographic superconductivity  

E-Print Network (OSTI)

We construct general models for holographic superconductivity parametrized by three couplings which are functions of a real scalar field and show that under general assumptions they describe superconducting phase transitions. While some features are universal and model independent, important aspects of the quantum critical behavior strongly depend on the choice of couplings, such as the order of the phase transition and critical exponents of second-order phase transitions. In particular, we study a one-parameter model where the phase transition changes from second to first order above some critical value of the parameter and a model with tunable critical exponents.

Francesco Aprile; Jorge G. Russo

2009-12-02T23:59:59.000Z

88

Superconductivity | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (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

89

Free-standing superconductive articles  

DOE Patents (OSTI)

A substrate-free, free-standing epitaxially oriented superconductive film including a layer of a template material and a layer of a ceramic superconducting material is provided together with a method of making such a substrate-free ceramic superconductive film by coating an etchable material with a template layer, coating the template layer with a layer of a ceramic superconductive material, coating the layer of ceramic superconductive material with a protective material, removing the etchable material by an appropriate means so that the etchable material is separated from a composite structure including the template layer, the ceramic superconductive material layer and the protective material layer, removing the protective material layer from the composite structure whereby a substrate-free, free-standing ceramic superconductive film remains.

Wu, X.D.; Muenchausen, R.E.

1991-12-31T23:59:59.000Z

90

Langmuir vacuum and superconductivity  

SciTech Connect

It is shown that, in the 'jelly' model of cold electron-ion plasma, the interaction between electrons and the quantum electromagnetic vacuum of Langmuir waves involves plasma superconductivity with an energy gap proportional to the energy of the Langmuir quantum.

Veklenko, B. A. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2012-06-15T23:59:59.000Z

91

Superconductivity for Electric Systems  

E-Print Network (OSTI)

and Energy Reliability ­ Superconductivity for Electric Systems #12;3 Control Milestones and Status Control Milestone Due Date Status Section 1.1: Wire Development. · Short sample RABiTS using slot-die MOD CeO2 cap manufacturing process. Highlights: 1) HTS Program CPS Control Milestone Met - Short sample RABiTS using slot

92

Superconductivity and electron tunneling  

Science Conference Proceedings (OSTI)

Experiments on the tunneling of electrons through a thin dielectric layer separating two superconducting metals are reported. Data are presented for the pairs AI-Pb, Sn-Pb, and In-Sn. Particular attention is paid to the form of the tunneling current ...

S. Shapiro; P. H. Smith; J. Nicol; J. L. Miles; P. F. Strong

1962-01-01T23:59:59.000Z

93

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

94

SUPERCONDUCTING VANADIUM BASE ALLOY  

DOE Patents (OSTI)

A new vanadium-base alloy which possesses remarkable superconducting properties is presented. The alloy consists of approximately one atomic percent of palladium, the balance being vanadium. The alloy is stated to be useful in a cryotron in digital computer circuits.

Cleary, H.J.

1958-10-21T23:59:59.000Z

95

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

DOE Green Energy (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

96

Overview of Superconductivity and Challenges in Applications  

E-Print Network (OSTI)

Considerable progress has been achieved during the last few decades in the various fields of applied superconductivity, while the related low temperature technology has reached a high level. Magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) are so far the most successful applications, with tens of thousands of units worldwide, but high potential can also be recognized in the energy sector, with high energy cables, transformers, motors, generators for wind turbines, fault current limiters and devices for magnetic energy storage. A large number of magnet and cable prototypes have been constructed, showing in all cases high reliability. Large projects involving the construction of magnets, solenoids as well as dipoles and quadrupoles are described in the present book. A very large project, the LHC, is currently in operation, demonstrating that superconductivity is a reliable technology, even in a device of unprecedented high complexity. A project of similar complexity is ITER, a fusion device...

Flükiger, Rene

2012-01-01T23:59:59.000Z

97

AFRD - Superconducting Magnets  

NLE Websites -- All DOE Office Websites (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

98

Equilibrium Distributions and Superconductivity  

E-Print Network (OSTI)

In this article two models for charges distributions are discussed. On the basis of our consideration we put different points of view for stationary state. We prove that only finite energy model for charges' distribution and well-known variation principle explain some well-known experimental results. A new model for superconductivity was suggested, too. In frame of that model some characteristic experimental results for superconductors is possible to explain.

Ashot Vagharshakyan

2011-06-07T23:59:59.000Z

99

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

100

Superconducting magnet of Aurora  

Science Conference Proceedings (OSTI)

The AURORAsuperconducting magnet system is composed of a cylindrical single?body magnet and a refrigeration system for superconducting coils. The magnet generates B z =1 T on the central orbit at the 150 MeV electron beam injection energy and B z =4.3 T at the 650 MeV storage energy. The diameter of the central orbit is 1 m. Iron poles and yokes are used for shielding the magnetic field

T. Takayama; SHI Accelerator Research Group

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Crystalline Color Superconductivity  

E-Print Network (OSTI)

We give an introduction crystalline color superconductivity, arguing that it is likely to occur wherever quark matter in which color-flavor locking does not occur is found. We survey the properties of this form of quark matter, and argue that its presence in a compact star may result in pulsar glitches, and thus in observable consequences. However, elucidation of this proposal requires an understanding of the crystal structure, which is not yet in hand.

Krishna Rajagopal

2001-09-14T23:59:59.000Z

102

Solitons in SO(5) Superconductivity  

E-Print Network (OSTI)

A model unifying superconductivity and antiferromagnetism using an underlying approximate SO(5) symmetry has injected energy into the field of high-temperature superconductivity. This model might lead to a variety of interesting solitons. In this paper, the idea that superconducting vortices may have antiferromagnetic cores is presented, along with the results of some preliminary numerical work. An outlook for future work, including speculations about other possible exotic solitons, is presented. 1

R. Mackenzie; Québec Hc J; J. M. Cline

1999-01-01T23:59:59.000Z

103

Superconducting Cable Construction and Testing  

Science Conference Proceedings (OSTI)

Superconducting cables, carrying three to five times more power than conventional cables, can meet increasing power demands in urban areas via retrofit applications. These high capacity cables will allow utilities to greatly enhance capacity, thereby giving the grid more flexibility and reliability. This report describes the development, construction, and testing of a superconducting cable system. Background In the late eighties, a new class of ceramic oxides was discovered with superconducting propertie...

2000-11-10T23:59:59.000Z

104

Superconducting Topological Insulators  

NLE Websites -- All DOE Office Websites (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.

105

Superconducting Topological Insulators  

NLE Websites -- All DOE Office Websites (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.

106

Superconducting Topological Insulators  

NLE Websites -- All DOE Office Websites (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.

107

Flavor Superconductivity & Superfluidity  

E-Print Network (OSTI)

In these lecture notes we derive a generic holographic string theory realization of a p-wave superconductor and superfluid. For this purpose we also review basic D-brane physics, gauge/gravity methods at finite temperature, key concepts of superconductivity and recent progress in distinct realizations of holographic superconductors and superfluids. Then we focus on a D3/D7-brane construction yielding a superconducting or superfluid vector-condensate. The corresponding gauge theory is 3+1-dimensional N=2 supersymmetric Yang-Mills theory with SU(N) color and SU(2) flavor symmetry. It shows a second order phase transition to a phase in which a U(1) subgroup of the SU(2) symmetry is spontaneously broken and typical superconductivity signatures emerge, such as a conductivity (pseudo-)gap and the Meissner-Ochsenfeld effect. Condensates of this nature are comparable to those recently found experimentally in p-wave superconductors such as a ruthenate compound. A string picture of the pairing mechanism and condensation is given using the exact knowledge of the corresponding field theory degrees of freedom.

Matthias Kaminski

2010-02-25T23:59:59.000Z

108

Magnetically leviated superconducting bearing  

DOE Patents (OSTI)

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

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

1993-01-01T23:59:59.000Z

109

Superconducting magnetic energy storage  

DOE Green Energy (OSTI)

Long-time varying-daily, weekly, and seasonal-power demands require the electric utility industry to have installed generating capacity in excess of the average load. Energy storage can reduce the requirement for less efficient excess generating capacity used to meet peak load demands. Short-time fluctuations in electric power can occur as negatively damped oscillations in complex power systems with generators connected by long transmission lines. Superconducting inductors with their associated converter systems are under development for both load leveling and transmission line stabilization in electric utility systems. Superconducting magnetic energy storage (SMES) is based upon the phenomenon of the nearly lossless behavior of superconductors. Application is, in principal, efficient since the electromagnetic energy can be transferred to and from the storage coils without any intermediate conversion to other energy forms. Results from a reference design for a 10-GWh SMES unit for load leveling are presented. The conceptual engineering design of a 30-MJ, 10-MW energy storage coil is discussed with regard to system stabilization, and tests of a small scale, 100-KJ SMES system are presented. Some results of experiments are provided from a related technology based program which uses superconducting inductive energy storage to drive fusion plasmas.

Rogers, J.D.; Boenig, H.J.; Hassenzahl, W.V.; Schermer, R.I.

1978-01-01T23:59:59.000Z

110

Superconductivity and Superfluidity  

E-Print Network (OSTI)

Currently there is a common belief that the explanation of superconductivity phenomenon lies in understanding the mechanism of the formation of electron pairs. Paired electrons, however, cannot form a superconducting condensate spontaneously. These paired electrons perform disorderly zero-point oscillations and there are no force of attraction in their ensemble. In order to create a unified ensemble of particles, the pairs must order their zero-point fluctuations so that an attraction between the particles appears. As a result of this ordering of zero-point oscillations in the electron gas, superconductivity arises. This model of condensation of zero-point oscillations creates the possibility of being able to obtain estimates for the critical parameters of elementary superconductors, which are in satisfactory agreement with the measured data. On the another hand, the phenomenon of superfluidity in He-4 and He-3 can be similarly explained, due to the ordering of zero-point fluctuations. It is therefore established that both related phenomena are based on the same physical mechanism.

B. V. Vasiliev

2010-08-16T23:59:59.000Z

111

Competition between singlet and triplet superconductivity  

E-Print Network (OSTI)

The competition between singlet and triplet superconductivity is examined in consideration of correlations on an extended Hubbard model. It is shown that the triplet superconductivity may not be included in the common Hubbard model since the strong correlation favors the singlet superconductivity, and thus the triplet superconductivity should be induced by the electron-phonon interaction and the ferromagnetic exchange interaction. We also present a superconducting qualification with which magnetism is unbeneficial to superconductivity.

Tian De Cao; Tie Bang Wang

2009-05-15T23:59:59.000Z

112

Hall effect in superconducting films  

E-Print Network (OSTI)

Near the superconducting phase transition, fluctuations significantly modify the electronic transport properties. Here we study the fluctuation corrections to the Hall conductivity in disordered films, extending previous ...

Michaeli, Karen

113

Superconducting VAR control. [Patent application  

DOE Patents (OSTI)

Static VAR control means are described employing an asymmetrically controlled Graetz bridge and a superconducting direct current coil having low losses and low cost characteristics.

Boenig, H.J.; Hassenzahl, W.V.

1980-12-05T23:59:59.000Z

114

High Pressure Studies of Superconductivity.  

E-Print Network (OSTI)

??Superconductivity has been studied extensively since it was first discovered over 100 years ago. High pressure studies, in particular, have been vital in furthering our… (more)

Hillier, Narelle Jayne

2013-01-01T23:59:59.000Z

115

Analytical and Experimental Studies on the Hybrid Fault Current Limiter Employing Asymmetric Non-Inductive Coil and Fast Switch  

E-Print Network (OSTI)

This paper deals with design and operating test of a novel hybrid FCL. The FCL system consists of a coil, a fast switch and a resistor for bypassing the fault current. The switch is driven by novel non-inductive coil ...

Yang, Seong Eun

116

High-Temperature Superconductivity Cable Demonstration Projects...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High-Temperature Superconductivity Cable Demonstration Projects High-Temperature Superconductivity Cable Demonstration Projects A National Effort to Introduce New Technology into...

117

Superconductivity Program Overview | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Program Overview Superconductivity Program Overview High-Temperature Superconductivity (HTS) has the potential for achieving a more fundamental change to electric power...

118

Thermal activation of superconducting Josephson junctions  

E-Print Network (OSTI)

Superconducting quantum circuits (SQCs) are being explored as model systems for scalable quantum computing architectures. Josephson junctions are extensively used in superconducting quantum interference devices (SQUIDs) ...

Devalapalli, Aditya P. (Aditya Prakash)

2007-01-01T23:59:59.000Z

119

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

120

Superconductivity Highlights | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (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

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

DOE Superconductivity Program Stakeholders  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Air Force Research Laboratory Air Force Research Laboratory Air Liquide Air Products and Chemicals Inc. American Electric Power American Superconductor Argonne National Laboratory BOC Group Brookhaven National Laboratory Composite Technology Development Consolidated Edison Cryo-Industries of America Inc. Delta Star Inc. Directed Vapor Technologies Department of Defense Department of Homeland Security Electric Power Research Institute Entergy Florida State University Long Island Power Authority Los Alamos National Laboratory Metal Oxide Technologies Inc. Mipox International Corp. National Grid National Institute for Standards & Tech. National Renewable Energy Laboratory Nissan Electric Co. Ltd. Nexans nkt Cables Group Oak Ridge National Laboratory Oxford Superconducting Technology Pacific Gas and Electric

122

Superconducting dipole electromagnet  

DOE Patents (OSTI)

A dipole electromagnet of especial use for bending beams in particle accelerators is wound to have high uniformity of magnetic field across a cross section and to decrease evenly to zero as the ends of the electromagnet are approached by disposing the superconducting filaments of the coil in the crescent-shaped nonoverlapping portions of two intersecting circles. Uniform decrease at the ends is achieved by causing the circles to overlap increasingly in the direction of the ends of the coil until the overlap is complete and the coil is terminated.

Purcell, John R. (San Diego, CA)

1977-07-26T23:59:59.000Z

123

Precursor of Color Superconductivity  

E-Print Network (OSTI)

We investigate possible precursory phenomena of color superconductivity at finite temperature $T$ with an effective theory of QCD. It is found that the fluctuation of the diquark pair field exists with a prominent strength even well above the critical temperature $T_c$. We show that such a fluctuaiton forms a collective mode, the corresponding pole of which approaches the origin as $T$ is lowered to $T_c$ in the complex energy plane. We discuss the possible relevance of the precursor to the observables to be detected in heavy-ion collisions.

M. Kitazawa; T. Koide; T. Kunihiro; Y. Nemoto

2002-12-06T23:59:59.000Z

124

Superconducting magnet cooling system  

DOE Patents (OSTI)

A device is provided for cooling a conductor to the superconducting state. The conductor is positioned within an inner conduit through which is flowing a supercooled liquid coolant in physical contact with the conductor. The inner conduit is positioned within an outer conduit so that an annular open space is formed therebetween. Through the annular space is flowing coolant in the boiling liquid state. Heat generated by the conductor is transferred by convection within the supercooled liquid coolant to the inner wall of the inner conduit and then is removed by the boiling liquid coolant, making the heat removal from the conductor relatively independent of conductor length.

Vander Arend, Peter C. (Center Valley, PA); Fowler, William B. (St. Charles, IL)

1977-01-01T23:59:59.000Z

125

Critical Magnetic Field Determination of Superconducting Materials  

Science Conference Proceedings (OSTI)

Superconducting RF technology is becoming more and more important. With some recent cavity test results showing close to or even higher than the critical magnetic field of 170-180 mT that had been considered a limit, it is very important to develop a way to correctly measure the critical magnetic field (H{sup RF}{sub c}) of superconductors in the RF regime. Using a 11.4 GHz, 50-MW, electric field at the sample surface. A model of the system is presented in this paper along with a discussion of preliminary experimental data.

Canabal, A.; Tajima, T.; /Los Alamos; Dolgashev, V.A.; Tantawi, S.G.; /SLAC; Yamamoto, T.; /Tsukuba, Natl. Res. Lab. Metrol.

2011-11-04T23:59:59.000Z

126

Tolerance Limits  

Science Conference Proceedings (OSTI)

... LIMITS Y ** *** 2-SIDED NORMAL TOLERANCE LIMITS: XBAR +- K*S REFERENCE--CRC HANDBOOK, PAGES 32-35 ...

2010-12-06T23:59:59.000Z

127

A worldwide overview of superconductivity development efforts for utility applications  

DOE Green Energy (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

128

Color Superconductivity in Asymmetric Matter  

E-Print Network (OSTI)

The influence of different chemical potential for different flavors on color superconductivity is analyzed. It is found that there is a first order transition as the asymmetry grows. This transition proceeds through the formation of bubbles of low density, flavor asymmetric normal phase inside a high density, superconducting phase with a gap {\\it larger} than the one found in the symmetric case. For small fixed asymmetries the system is normal at low densities and superconducting only above some critical density. For larger asymmetries the two massless quarks system stays in the mixed state for arbitrarily high densities.

Paulo F. Bedaque

1999-10-06T23:59:59.000Z

129

Superconducting coil protection  

SciTech Connect

The protection system is based on a two-phase construction program. Phase I is the development of a reliable hardwired relay control system with a digital loop utilizing firmware and a microprocessor controller. Phase II is an expansion of the digital loop to include many heretofore unmonitored coil variables. These new monitored variables will be utilized to establish early quench detection and to formulate confirmation techniques of the quench detection mechanism. Established quench detection methods are discussed and a new approach to quench detection is presented. The new circuit is insensitive to external pulsed magnetic fields and the associated induced voltages. Reliability aspects of the coil protection system are discussed with respect to shutdowns of superconducting coil systems. Redundance and digital system methods are presented as related topics. (auth)

Woods, E.L.

1975-01-01T23:59:59.000Z

130

Superconducting combined function magnets  

SciTech Connect

Superconducting accelerators and storage rings, presently under construction or in the design phase, are based on separate dipole and quadrupole magnets. It is here suggested that a hybrid lattice configuration consisting of dipoles and combined function gradient magnets would: (1) reduce the number of magnet units and their total cost; and (2) increase the filling factor and thus the energy at a given field. Coil cross sections are presented for the example of the Brookhaven Colliding Beam Accelerator. An asymmetric two-layer cable gradient magnet would have transfer functions of 10.42 G/A and 0.628 G cm/sup -1//A versus 15.77 G/A and 2.03 G cm/sup -1//A of the present separate dipoles and quadrupoles.

Hahn, H.; Fernow, R.C.

1983-01-01T23:59:59.000Z

131

Superconducting energy storage  

DOE Green Energy (OSTI)

This report describes the status of energy storage involving superconductors and assesses what impact the recently discovered ceramic superconductors may have on the design of these devices. Our description is intended for R&D managers in government, electric utilities, firms, and national laboratories who wish an overview of what has been done and what remains to be done. It is assumed that the reader is acquainted with superconductivity, but not an expert on the topics discussed here. Indeed, it is the author`s aim to enable the reader to better understand the experts who may ask for the reader`s attention, support, or funding. This report may also inform scientists and engineers who, though expert in related areas, wish to have an introduction to our topic.

Giese, R.F.

1993-10-01T23:59:59.000Z

132

Superconducting magnetic coil  

DOE Patents (OSTI)

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

Aized, D.; Schwall, R.E.

1999-06-22T23:59:59.000Z

133

Superconducting magnetic energy storage  

SciTech Connect

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

134

High Tc Superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

by C. Kim (SSRL), D. H. Lu (Stanford), K. M. Shen (Stanford) and Z.-X. Shen (Stanford/SSRL) by C. Kim (SSRL), D. H. Lu (Stanford), K. M. Shen (Stanford) and Z.-X. Shen (Stanford/SSRL) Extensive research efforts to study the novel electronic properties of high-Tc superconductors and their related materials by angle-resolved photoemission spectroscopy at a recently commissioned Beam Line 5-4 (led by Z.-X. Shen) continue to be successful, producing many important results. These results, which are highlighted by five articles recently published in Physical Review Letters and one in Science, brought our understanding steps closer to solving the mystery of the high-Tc superconductivity. With the development of the latest generation of ultra-high resolution electron spectrometers in the past few years, the technique of angle resolved photoemission spectroscopy (ARPES) has recently experienced a renaissance. Nowhere is this revolution more evident than in the study of the high-temperature superconductors, which more than a decade after their discovery, continue to defy theoretical explanation. Recent ARPES experiments performed at Beam Line 5-4 have led to critical new discoveries about the fundamental nature of these mysterious superconductors and are now changing the way that the physics community views these materials. An excellent benchmark for the huge leap in detector resolution and technology is the recent work on Sr2RuO4. Although it belongs to a slightly different family than the high- temperature superconductors, its exotic superconducting mechanism (Tc = 1K) and complex electronic structure make it itself a fascinating material. In the past, due to poor resolutions, ARPES studies on this material were in disagreement with theory and other experimental techniques.

135

Brett Parker | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

136

Partial Deconfinement in Color Superconductivity  

E-Print Network (OSTI)

We analyze the fate of the unbroken SU(2) color gauge interactions for 2 light flavors color superconductivity at non zero temperature. Using a simple model we compute the deconfining/confining critical temperature and show that is smaller than the critical temperature for the onset of the superconductive state itself. The breaking of Lorentz invariance, induced already at zero temperature by the quark chemical potential, is shown to heavily affect the value of the critical temperature and all of the relevant features related to the deconfining transition. Modifying the Polyakov loop model to describe the SU(2) immersed in the diquark medium we argue that the deconfinement transition is second order. Having constructed part of the equation of state for the 2 color superconducting phase at low temperatures our results are relevant for the physics of compact objects featuring a two flavor color superconductive state.

F. Sannino; N. Marchal; W. Schäfer

2002-02-26T23:59:59.000Z

137

QUENCHES IN LARGE SUPERCONDUCTING MAGNETS  

E-Print Network (OSTI)

stored energy (J); jo is the superconducting matrix currentstored energy Eo(J) XBL 777-1557 Superconductor matrixmatrix current density as a function of sto~ed magnetic energy

Eberhard, P.H.

2010-01-01T23:59:59.000Z

138

The challenge of unconventional superconductivity.  

SciTech Connect

During the past few decades, several new classes of superconductors have been discovered that do not appear to be related to traditional superconductors. The source of the superconductivity of these materials is likely different from the electron-ion interactions that are at the heart of conventional superconductivity. Developing a rigorous theory for any of these classes of materials has proven to be a difficult challenge and will remain one of the major problems in physics in the decades to come.

Norman, M. R. (Materials Science Division)

2011-04-08T23:59:59.000Z

139

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

140

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

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Process for producing clad superconductive materials  

DOE Patents (OSTI)

A process for fabricating superconducting composite wire by the steps of placing a superconductive precursor admixture capable of undergoing a self propagating combustion in stoichiometric amounts sufficient to form a superconductive product within a metal tube, sealing one end of said tube, igniting said superconductive precursor admixture whereby said superconductive precursor admixture endburns along the length of the admixture, and cross-section reducing said tube at a rate substantially equal to the rate of burning of said superconductive precursor admixture and at a point substantially planar with the burnfront of the superconductive precursor mixture, whereby a clad superconductive product is formed in situ, the product characterized as superconductive without a subsequent sintering stage, is disclosed.

Cass, R.B.; Ott, K.C.; Peterson, D.E.

1991-03-19T23:59:59.000Z

142

Process for producing clad superconductive materials  

DOE Patents (OSTI)

A process for fabricating superconducting composite wire by the steps of placing a superconductive precursor admixture capable of undergoing a self propagating combustion in stoichiometric amounts sufficient to form a superconductive product within a metal tube, sealing one end of said tube, igniting said superconductive precursor admixture whereby said superconductive precursor admixture endburns along the length of the admixture, and cross-section reducing said tube at a rate substantially equal to the rate of burning of said superconductive precursor admixture and at a point substantially planar with the burnfront of the superconductive precursor mixture, whereby a clad superconductive product is formed in situ, the product characterized as superconductive without a subsequent sintering stage, is disclosed.

Cass, Richard B. (Ringoes, NJ); Ott, Kevin C. (Los Alamos, NM); Peterson, Dean E. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

143

Scaling of Superconducting Switches for Extraction of Magnetic Energy  

E-Print Network (OSTI)

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

Ballarino, A

2010-01-01T23:59:59.000Z

144

Strongly correlated electron behavior : superconductivity and non-Fermi liquid behavior in Ce?-xRxColn?  

E-Print Network (OSTI)

C. Superconductivity . . . . . . . . . . . . . . . . . . .1. Heavy Fermion Superconductivity . . . . . . .Introductioon to Superconductivity, ch.1, (Dover, New York [

Gonzales, Eileen

2009-01-01T23:59:59.000Z

145

bylaws of the superconducting materials committee of the minerals ...  

Science Conference Proceedings (OSTI)

of superconductivity through organized symposia and technical aspects of meetings ... macroscopic descriptions of superconductivity; physical, chemical, and.

146

Fault Current Limiters  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Fault Fault Current Limiters Superconducting & Solid-state Power Equipment 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 Plugging America Into the Future of Power What are FCLs? A fault is an unintentional short circuit, or partial short-circuit, in an electric circuit. A variety of factors such as lightning, downed power lines, or crossed power lines cause faults. During a fault, excessive current-called fault current- flows through the electrical system often resulting in a failure of one section of that system by causing a

147

A scalable control system for a superconducting adiabatic quantum optimization processor  

E-Print Network (OSTI)

We have designed, fabricated and operated a scalable system for applying independently programmable time-independent, and limited time-dependent flux biases to control superconducting devices in an integrated circuit. Here we report on the operation of a system designed to supply 64 flux biases to devices in a circuit designed to be a unit cell for a superconducting adiabatic quantum optimization system. The system requires six digital address lines, two power lines, and a handful of global analog lines.

Johnson, M W; Maibaum, F; Tolkacheva, E; Berkley, A J; Chapple, E M; Harris, R; Johansson, J; Lanting, T; Perminov, I; Ladizinsky, E; Oh, T; Rose, G

2009-01-01T23:59:59.000Z

148

A scalable control system for a superconducting adiabatic quantum optimization processor  

E-Print Network (OSTI)

We have designed, fabricated and operated a scalable system for applying independently programmable time-independent, and limited time-dependent flux biases to control superconducting devices in an integrated circuit. Here we report on the operation of a system designed to supply 64 flux biases to devices in a circuit designed to be a unit cell for a superconducting adiabatic quantum optimization system. The system requires six digital address lines, two power lines, and a handful of global analog lines.

M. W. Johnson; P. Bunyk; F. Maibaum; E. Tolkacheva; A. J. Berkley; E. M. Chapple; R. Harris; J. Johansson; T. Lanting; I. Perminov; E. Ladizinsky; T. Oh; G. Rose

2009-07-22T23:59:59.000Z

149

Superconducting magnetic energy storage  

SciTech Connect

The U.S. electric utility industry transmits power to customers at a rate equivalent to only 60% of generating capacity because, on an annual basis, the demand for power is not constant. Load leveling and peak shaving units of various types are being used to increase the utilization of the base load nuclear and fossil power plants. The Los Alamos Scientific Laboratory (LASL) is developing superconducting magnetic energy storage (SMES) systems which will store and deliver electrical energy for the purpose of load leveling, peak shaving, and the stabilization of electric utility networks. This technology may prove to be an effective means of storing energy for the electric utilities because (1) it has a high efficiency (approximately 90%), (2) it may improve system stability through the fast response of the converter, and (3) there should be fewer siting restrictions than for other load leveling systems. A general SMES system and a reference design for a 10-GWh unit for load leveling are described; and the results of some recent converter tests are presented.

Hassenzahl, W.V.; Boenig, H.J.

1977-01-01T23:59:59.000Z

150

Superconducting Cable Termination  

SciTech Connect

Disclosed is a termination that connects high temperature superconducting (HTS) cable immersed in pressurized liquid nitrogen to high voltage and neutral (shield) external bushings at ambient temperature and pressure. The termination consists of a splice between the HTS power (inner) and shield (outer) conductors and concentric copper pipes which are the conductors in the termination. There is also a transition from the dielectric tape insulator used in the HTS cable to the insulators used between and around the copper pipe conductors in the termination. At the warm end of the termination the copper pipes are connected via copper braided straps to the conventional warm external bushings which have low thermal stresses. This termination allows for a natural temperature gradient in the copper pipe conductors inside the termination which enables the controlled flashing of the pressurized liquid coolant (nitrogen) to the gaseous state. Thus the entire termination is near the coolant supply pressure and the high voltage and shield cold bushings, a highly stressed component used in most HTS cables, are eliminated. A sliding seal allows for cable contraction as it is cooled from room temperature to ˜72-82 K. Seals, static vacuum, and multi-layer superinsulation minimize radial heat leak to the environment.

Sinha, Uday K. (Carrollton, GA); Tolbert, Jerry (Newnan, GA)

2005-08-30T23:59:59.000Z

151

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

152

Nonperturbative QCD vacuum and Colour Superconductivity  

E-Print Network (OSTI)

We discuss the possibility of existence of colour superconducting state in real QCD vacuum with nonzero gluon condensate. We argue, that nonperturbative gluonic fields might play a crucial role in colour superconductivity scenario.

N. O. Agasian; B. O. Kerbikov; V. I. Shevchenko

1999-02-12T23:59:59.000Z

153

Recent Developments in High Temperature Superconductivity  

E-Print Network (OSTI)

New material systems and the experimental progress of high temperature superconductivity are briefly reviewed. We examine both oxides and non-oxides which exhibit stable and/or unstable superconductivity at high temperatures.

Hor, P. H.

1988-09-01T23:59:59.000Z

154

Two key questions about color superconductivity  

E-Print Network (OSTI)

We pose two key questions about color superconductivity: What are the effects of the large strange quark mass, and what are the observable consequences of color superconductivity? Motivated by the first question, we study ...

Kundu, Joydip, 1977-

2004-01-01T23:59:59.000Z

155

Electrothermal simulation of superconducting nanowire avalanche photodetectors  

E-Print Network (OSTI)

We developed an electrothermal model of NbN superconducting nanowire avalanche photodetectors (SNAPs) on sapphire substrates. SNAPs are single-photon detectors consisting of the parallel connection of N superconducting ...

Marsili, Francesco

156

Superconductivity in the system of p electrons  

SciTech Connect

The problem of superconductivity in an electron system with partly filled sp shell is studied. The scattering amplitudes are determined and the equations of superconductivity are derived from the assumption that the Hubbard energy is the largest energy parameter.

Zaitsev, R. O., E-mail: Zaitsev_rogdai@mail.ru [Moscow State Institute of Physics and Technology (Russian Federation)

2012-10-15T23:59:59.000Z

157

Superconducting Low Voltage Direct Current (LVDC) Networks  

Science Conference Proceedings (OSTI)

A low voltage dc superconducting distribution network is a challenging future opportunity for power distribution. This report presents a scheme for a superconducting, parallel- connected, multiterminal dc transmission system.

1994-04-27T23:59:59.000Z

158

NETL F 451.1-1/1 Categorical Exclusion (CX) Designation Form  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

44 44 Waukesha Electric System, Inc OE Southern Cal Edison activities Energy Delivery Technologies Div 2010 David Szucs approx. July 2010- January 2015 Irvine, CA "Recovery Act-Fault Current Limiting (FCL) Superconducting Transformer" Southern California Edison will install & operate a prototype FCL superconducting transformer rated 28 MVA, 66kV/12kV service, built by Waukesha Electric, in their MacArthur substation as a demonstration. 07 02 2010 David Szucs Digitally signed by David Szucs DN: cn=David Szucs, o=NETL, ou=EDTD, email=szucs@netl.doe.gov, c=US Date: 2010.07.02 13:16:07 -04'00' 07 16 2010 Fred E. Pozzuto Digitally signed by Fred E. Pozzuto DN: cn=Fred E. Pozzuto, o=USDOE, ou=NETL-Office of Project Facilitation and Compliance, email=fred.pozzuto@netl.doe.gov, c=US

159

A unified theory of superconductivity  

E-Print Network (OSTI)

In this paper, we study the reliability of BCS theory as a scientific explanation of the mystery of superconductivity. It is shown clearly that the phonon-mediated BCS theory is fundamentally incorrect. Two kinds of glues, pairing (pseudogap) glue and superconducting glue, are suggested based on a real space Coulomb confinement effect. The scenarios provide a unified explanation of the pairing symmetry, pseudogap and superconducting states, charge stripe order, spin density wave (SDW), checkerboard-type charge-ordered phase, magic doping fractions and vortex structures in conventional and unconventional (the high-Tc cuprates and MgB2) superconductors. The theory agrees with the existence of a pseudogap in high-temperature superconductors, while no pseudogap feature could be observed in MgB2 and most of the conventional superconductors. Our results indicate that the superconducting phase can coexist with a inclined hexagonal vortex lattice in pure MgB2 single crystal with a charge carrier density ps=1.49*10^{22}/cm^{3}. Finally, the physical reasons why the good conductors (for example, Ag, Au, and Cu) and the overdoped high-Tc superconductors are non-superconducting are also explored.

Xiuqing Huang

2008-04-10T23:59:59.000Z

160

Fast superconducting magnetic field switch  

DOE Patents (OSTI)

The superconducting magnetic switch or fast kicker magnet is employed with an electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater than the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles. Magnetic switches and particularly fast kicker magnets are used in the accelerator industry to quickly deflect particle beams into and out of various transport lines, storage rings, dumps, and specifically to differentially route individual bunches of particles from a train of bunches which are injected or ejected from a given ring.

Goren, Y.; Mahale, N.K.

1995-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Fast superconducting magnetic field switch  

DOE Patents (OSTI)

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

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

1996-01-01T23:59:59.000Z

162

Brittle superconducting magnets: an equivilent strain model  

Science Conference Proceedings (OSTI)

To exceed fields of 10 T in accelerator magnets, brittle superconductors like A15 Nb{sub 3}Sn and Nb{sub 3}Al or ceramic High Temperature Superconductors have to be used. For such brittle superconductors it is not their maximum tensile yield stress that limits their structural resistance as much as strain values that provoke deformations in their delicate lattice, which in turn affect their superconducting properties. Work on the sensitivity of Nb{sub 3}Sn cables to strain has been conducted in a number of stress states, including uniaxial and multi-axial, producing usually different results. This has made the need of a constituent design criterion imperative for magnet builders. In conventional structural problems an equivalent stress model is typically used to verify mechanical soundness. In the superconducting community a simple scalar equivalent strain to be used in place of an equivalent stress would be an extremely useful tool. As is well known in fundamental mechanics, there is not one single way to reduce a multiaxial strain state as represented by a 2nd order tensor to a scalar. The conceptual experiment proposed here will help determine the best scalar representation to use in the identification of an equivalent strain model.

Barzi, E.; /Fermilab; Danuso, M.

2010-08-01T23:59:59.000Z

163

BCS-Bose Crossover in Color Superconductivity  

E-Print Network (OSTI)

It is shown that the onset of the color superconducting phase occurs in the BCS-BE crossover region.

B. O. Kerbikov

2002-04-17T23:59:59.000Z

164

Color Superconductivity: Symmetries and Effective Lagrangians  

E-Print Network (OSTI)

I briefly review the symmetries and the associated low energy effective Lagrangian for two light flavor Color Superconductivity (2SC).

Francesco Sannino

2001-07-24T23:59:59.000Z

165

Symmetric superconducting states in thin films  

Science Conference Proceedings (OSTI)

Keywords: Ginzburg-Landau theory for superconductivity, Meissner effect, boundary value problems, calculus of variations, implicit difference scheme, maximum principle

Sheng Wang; Yisong Yang

1992-06-01T23:59:59.000Z

166

Magnetism and Superconductivity in Iron Pnictides  

Science Conference Proceedings (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

167

Superconducting Cuprates on Catalytic Substrates - Energy ...  

Electricity Transmission Superconducting Cuprates on Catalytic Substrates Brookhaven National Laboratory. Contact BNL About This Technology Technology Marketing ...

168

Compact High-Temperature Superconducting Cable Wins ' ...  

Science Conference Proceedings (OSTI)

Compact High-Temperature Superconducting Cable Wins 'R&D 100' Award. From NIST Tech Beat: June 22, 2011. ...

2011-07-06T23:59:59.000Z

169

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, X.D.; Muenchausen, R.E.

1991-12-31T23:59:59.000Z

170

Superconducting Multilayer Interconnect - lbl.gov  

Technique to fabricate multilayer interconnects and multiturn flux transformers for use with direct current superconducting quantum interference ...

171

Ferromagnetism and Superconductivity in Quark Matter - Color magnetic superconductivity -  

E-Print Network (OSTI)

A coexistent phase of spin polarization and color superconductivity in high-density QCD is studied at zero temperature. The axial-vector self-energy stemming from the Fock exchange term of the one-gluon-exchange interaction has a central role to cause spin polarization. As a significant feature, the Fermi surface is deformed by the axial-vector self-energy and then rotation symmetry is spontaneously broken down. The gap function results in being anisotropic in the momentum space in accordance with the deformation. It is found that spin polarization barely conflicts with color superconductivity, and almost coexists with it.

Toshitaka Tatsumi; Tomoyuki Maruyama; Eiji Nakano

2003-12-25T23:59:59.000Z

172

Superconducting wire with improved strain characteristics  

DOE Patents (OSTI)

A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improves the strain characteristics of the wire.

Luhman, Thomas (Westhampton Beach, NY); Klamut, Carl J. (E. Patchogue, NY); Suenaga, Masaki (Bellport, NY); Welch, David (Stony Brook, NY)

1982-01-01T23:59:59.000Z

173

Superconducting wire with improved strain characteristics  

DOE Patents (OSTI)

A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the strain characteristics of the wire.

Luhman, Thomas (Westhampton Beach, NY); Klamut, Carl J. (East Patchogue, NY); Suenaga, Masaki (Bellport, NY); Welch, David (Stony Brook, NY)

1982-01-01T23:59:59.000Z

174

Superconducting wire with improved strain characteristics  

DOE Patents (OSTI)

A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the strain characteristics of the wire.

Luhman, T.; Klamut, C.J.; Suenaga, M.; Welch, D.

1979-12-19T23:59:59.000Z

175

Electronic structure of superconductivity refined  

NLE Websites -- All DOE Office Websites (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.

176

Ramesh Gupta | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

177

Strain tolerant microfilamentary superconducting wire  

DOE Patents (OSTI)

A strain tolerant microfilamentary wire capable of carrying superconducting currents is provided comprising a plurality of discontinuous filaments formed from a high temperature superconducting material. The discontinuous filaments have a length at least several orders of magnitude greater than the filament diameter and are sufficiently strong while in an amorphous state to withstand compaction. A normal metal is interposed between and binds the discontinuous filaments to form a normal metal matrix capable of withstanding heat treatment for converting the filaments to a superconducting state. The geometry of the filaments within the normal metal matrix provides substantial filament-to-filament overlap, and the normal metal is sufficiently thin to allow supercurrent transfer between the overlapped discontinuous filaments but is also sufficiently thick to provide strain relief to the filaments.

Finnemore, Douglas K. (Ames, IA); Miller, Theodore A. (Tuscon, AZ); Ostenson, Jerome E. (Ames, IA); Schwartzkopf, Louis A. (Mankato, MN); Sanders, Steven C. (Ames, IA)

1993-02-23T23:59:59.000Z

178

Dual control active superconductive devices  

Science Conference Proceedings (OSTI)

A dual control active superconducting device is described comprising; (a) a first device having a first main conduction channel formed of a film of superconductor on a substrate, an active weak link region interposed in the first main conduction channel, the active weak link region composed of a plurality of links formed of a thin film of superconductor separated by non-superconductive voids, the thickness and lateral dimensions of the links selected such that magnetic flux can propagate across the weak link region when it is superconducting, and a first control line having a portion adjacent to the active weak link region of the first main conduction channel such that current in the first control line will impose a magnetic flux on the weak link region; (b) a second superconducting device having a second main conduction channel formed of a film of superconductor on a substrate, an active weak link region interposed in the second main conduction channel, the active weak link region composed of at least one link formed of a thin film of superconductor separated by non-superconductive voids, the thickness and lateral dimensions of the links selected such that magnetic flux can propagate across the weak link region when it is superconducting, and a second control line having a portion adjacent to the active weak link region such that current in the second control line will impose a magnetic flux on the weak link region in the second main conduction channel; (c) an internal control line electrically connected to receive the current passed through the first main conduction channel and having a portion adjacent to the active weak link region of the second main conduction channel such that a current in the internal control line will impose a magnetic flux on the weak link region; and (d) electrical connectors connected to provide input current to the first and second main conduction channels and to conduct the output current.

Martens, J.S.; Beyer, J.B.; Nordman, J.E.; Hohenwarter, G.K.G.

1993-07-20T23:59:59.000Z

179

Superconductivity and Chiral Symmetry Breaking with Fermion Clusters  

E-Print Network (OSTI)

Cluster variables have recently revolutionized numerical work in certain models involving fermionic variables. This novel representation of fermionic partition functions is continuing to find new applications. After describing results from a study of a two dimensional Hubbard type model that confirm a superconducting transition in the Kosterlitz-Thouless universality class, we show how a cluster type algorithm can be devised to study the chiral limit of strongly coupled lattice gauge theories with staggered fermions.

Shailesh Chandrasekharan

2001-10-16T23:59:59.000Z

180

A Physical Picture of Superconductivity  

E-Print Network (OSTI)

A universal mechanism of superconductivity applicable to “low temperature” and “high temperature ” superconductors is proposed in this paper. With this model of mechanism experimental facts of superconductors can be qualitatively explained. A function is introduced to describe the average separation distance between vibrating lattice atoms, which is crucial for the transition from normal to superconductive state. However, the most attractive and exciting conclusion that can be derived from this physical picture, is that given atoms of other element be successfully sandwiched between ferromagnetic atoms one by one, a superconductor constructed this way is most likely to have a very high transition temperature.

W. Z. Shangguan; T. C. Au-yeung

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Freely oriented portable superconducting magnet  

SciTech Connect

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

Schmierer, Eric N. (Los Alamos, NM); Prenger, F. Coyne (Los Alamos, NM); Hill, Dallas D. (Los Alamos, NM)

2010-01-12T23:59:59.000Z

182

HTS Magnet Program | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

183

Free-standing oxide superconducting articles  

DOE Patents (OSTI)

A substrate-free, free-standing epitaxially oriented superconductive film including a layer of a template material and a layer of a ceramic superconducting material is provided together with a method of making such a substrate-free ceramic superconductive film by coating an etchable material with a template layer, coating the template layer with a layer of a ceramic superconductive material, coating the layer of ceramic superconductive material with a protective material, removing the etchable material by an appropriate means so that the etchable material is separated from a composite structure including the template layer.

Wu, X.D.; Muenchausen, R.E.

1993-12-14T23:59:59.000Z

184

Meissner superconductivity in itinerant ferromagnets  

E-Print Network (OSTI)

Recent results about the coexistence of ferromagnetism and unconventional superconductivity with spin-triplet Cooper pairing are reviewed on the basis of the quasi-phenomenological Ginzburg-Landau theory. The superconductivity in the mixed phase of coexistence of ferromagnetism and unconventional superconductivity is triggered by the spontaneous magnetization. The mixed phase is stable whereas the other superconducting phases that usually exist in unconventional superconductors are either unstable or metastable at relatively low temperatures in a quite narrow domain of the phase diagram and the stability properties are determined by the particular values of Landau parameters. The phase transitions from the normal phase to the phase of coexistence is of first order while the phase transition from the ferromagnetic phase to the coexistence phase can be either of first or second order depending on the concrete substance. The Cooper pair and crystal anisotropy are relevant to a more precise outline of the phase diagram shape and reduce the degeneration of the ground states of the system. The results are discussed in view of application to itinerant ferromagnetic compounds as UGe2, ZrZn2, URhGe. 1

D. V. Shopova; D. I. Uzunov

2005-01-01T23:59:59.000Z

185

Superconducting flux flow digital circuits  

DOE Patents (OSTI)

A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs) are disclosed. Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics. 8 figs.

Hietala, V.M.; Martens, J.S.; Zipperian, T.E.

1995-02-14T23:59:59.000Z

186

Superconducting flux flow digital circuits  

DOE Patents (OSTI)

A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs). Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics.

Hietala, Vincent M. (Placitas, NM); Martens, Jon S. (Sunnyvale, CA); Zipperian, Thomas E. (Albuquerque, NM)

1995-01-01T23:59:59.000Z

187

Direct Observation of Coexistence of Ferromagnetism and Superconductivity in RuSr2(Gd0.7Ce0.3)2Cu2O10  

E-Print Network (OSTI)

Recent reports of the detecting of ferromagnetism and superconductivity in ruthenium-cuprates have aroused great interest. Unfortunately, whether the two antagonistic phenomena coexist in the same space in the compounds remains unresolved. By employing the magneto-optical-imaging technique, ferromagnetism and superconductivity were indeed directly observed to coexist in the same space in RuSr2(Gd0.7Ce0.3)2Cu2O10 within the experimental resolution of ? 10 µm. The observation sets a length scale limit for models proposed to account for the competition between ferromagnetism and superconductivity, especially d-wave superconductivity, in this interesting class of compounds.

unknown authors

2008-01-01T23:59:59.000Z

188

Bifurcation analysis for phase transitions in superconducting rings with nonuniform thickness  

Science Conference Proceedings (OSTI)

Keywords: Ginzburg-Landau functional, Little-Parks experiment, superconducting rings, superconductivity

Jorge Berger; Jacob Rubinstein

1998-02-01T23:59:59.000Z

189

e Lens Solenoid | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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.

190

Tunable high-q superconducting notch filter  

DOE Patents (OSTI)

A superconducting notch filter is made of three substrates disposed in a cryogenic environment. A superconducting material is disposed on one substrate in a pattern of a circle and an annular ring connected together. The second substrate has a corresponding pattern to form a parallel plate capacitor and the second substrate has the circle and annular ring connected by a superconducting spiral that forms an inductor. The third substrate has a superconducting spiral that is placed parallel to the first superconducting spiral to form a transformer. Relative motion of the first substrate with respect to the second is effected from outside the cryogenic environment to vary the capacitance and hence the frequency of the resonant circuit formed by the superconducting devices.

Pang, C.S.; Falco, C.M.; Kampwirth, R.T.; Schuller, I.K.

1979-11-29T23:59:59.000Z

191

Composite for superconducting metal oxide  

DOE Patents (OSTI)

A principal objective of the invention is to provide a new superconducting composite which has a greatly improved ductility and fracture resistance to assist in the fabrication and processing of superconductors and to provide long service life. A principal objective of the present invention is to provide a composite superconductor comprising a continuous superconductor phase and a minor amount of silver present as a discontinuous phase.

Singh, Jitendra P.; Shi, Donglu; Capone, D.W. II; Dusek, J.T.

1988-12-23T23:59:59.000Z

192

Ten questions and answers about superconductivity  

E-Print Network (OSTI)

This work answers the basic questions of superconductivity in a question-and-answer format. We extend a basic hypothesis to various superconductors. This hypothesis is that superconductivity requires that the pairing gap locates around the Fermi level. On the basis of this hypothesis our calculations give the so-called three factor theory with which some key problems of the high temperature superconductivity are explained.

Tian De Cao

2010-06-29T23:59:59.000Z

193

Superconducting thin films on potassium tantalate substrates  

DOE Patents (OSTI)

A superconductive system for the lossless transmission of electrical current comprising a thin film of superconducting material Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x epitaxially deposited upon a KTaO.sub.3 substrate. The KTaO.sub.3 is an improved substrate over those of the prior art since the it exhibits small lattice constant mismatch and does not chemically react with the superconducting film.

Feenstra, Roeland (Oak Ridge, TN); Boatner, Lynn A. (Oak Ridge, TN)

1992-01-01T23:59:59.000Z

194

Dual control active superconductive devices  

DOE Patents (OSTI)

A superconducting active device has dual control inputs and is constructed such that the output of the device is effectively a linear mix of the two input signals. The device is formed of a film of superconducting material on a substrate and has two main conduction channels, each of which includes a weak link region. A first control line extends adjacent to the weak link region in the first channel and a second control line extends adjacent to the weak link region in the second channel. The current flowing from the first channel flows through an internal control line which is also adjacent to the weak link region of the second channel. The weak link regions comprise small links of superconductor, separated by voids, through which the current flows in each channel. Current passed through the control lines causes magnetic flux vortices which propagate across the weak link regions and control the resistance of these regions. The output of the device taken across the input to the main channels and the output of the second main channel and the internal control line will constitute essentially a linear mix of the two input signals imposed on the two control lines. The device is especially suited to microwave applications since it has very low input capacitance, and is well suited to being formed of high temperature superconducting materials since all of the structures may be formed coplanar with one another on a substrate.

Martens, Jon S. (Albuquerque, NM); Beyer, James B. (Madison, WI); Nordman, James E. (Madison, WI); Hohenwarter, Gert K. G. (Madison, WI)

1993-07-20T23:59:59.000Z

195

Superconductivity with Stripes | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

| 2000 | 1998 | Subscribe to APS Science Highlights rss feed Superconductivity with Stripes October 18, 2013 Bookmark and Share The interplay between stripe order,...

196

Superconductivity Technology Center - Los Alamos National Lab ...  

Researchers at the facility conduct research and development on processes for fabrication of high temperature superconducting tapes, measurement of the physical and ...

197

Center for Emergent Superconductivity 2013 Fall Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Center for Emergent Superconductivity (CES) 2013 Fall Workshop Homepage Registration pulldown Talks pulldown CES Workshop Talks CES Jr. Research Talks Programs pulldown Contact Us...

198

Center for Emergent Superconductivity 2013 Fall Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

main gate, please inform the guard you are attending the Center for Emergent Superconductivity 2013 Fall Workshop workshop. You may be requested to check in at the security...

199

High Temperature Interfacial Superconductivity - Energy Innovation ...  

Cuprate superconductors exhibit relatively high transition temperatures, but their unit cells are complex and large. Localizing a superconducting layer to a small ...

200

Publications | Ramesh Gupta | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

for muon collider" (pdf), R. Gupta, et al., 2010 Applied Superconductivity Conference, Washington, DC, August 2010. Slides from the talk (pdf) "Second Generation HTS Quadrupole...

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

ORNL superconducting wire yields unprecedented performance |...  

NLE Websites -- All DOE Office Websites (Extended Search)

ORNL | News | News Releases | 2013 SHARE Media Contact: Morgan McCorkle Communications 865.574.7308 ORNL superconducting wire yields unprecedented performance This figure shows the...

202

Two key questions about color superconductivity.  

E-Print Network (OSTI)

??We pose two key questions about color superconductivity: What are the effects of the large strange quark mass, and what are the observable consequences of… (more)

Kundu, Joydip, 1977-

2004-01-01T23:59:59.000Z

203

Digital Cable Goes Quantum: NIST Debuts Superconducting ...  

Science Conference Proceedings (OSTI)

... The setup resembles a miniature version of a cable-television transmission line, but with some powerful added features, including superconducting ...

2012-06-08T23:59:59.000Z

204

A Superconducting transformer system for high current cable testing  

E-Print Network (OSTI)

A Superconducting Transformer System for High Current CableDC) superconducting transformer system for the high currentsuperconducting cables. The transformer consists of a core-

Godeke, A.

2010-01-01T23:59:59.000Z

205

Magnetism and superconductivity observed to exist in harmony  

NLE Websites -- All DOE Office Websites (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,...

206

Current Challenges and Physics of Superconducting Radio-Frequency...  

NLE Websites -- All DOE Office Websites (Extended Search)

Recent performance advances in superconducting RF (SRF) cavities have made RF superconductivity a vital technology for accelerators which serve a variety of experimental...

207

Commissioning of the superconducting ECR ion source VENUS  

E-Print Network (OSTI)

COMMISSIONING OF THE SUPERCONDUCTING ECR ION SOURCE VENUS *paper describes the ongoing commissioning. Initial resultscoils [2]. During commissioning of the superconducting

Leitner, Daniela; Abbott, Steve R.; Dwinell, Roger D.; Leitner, Matthaeus; Taylor, Clyde; Lyneis, Claude M.

2003-01-01T23:59:59.000Z

208

Quantum transport and field-induced superconductivity in carbon nanotubes.  

E-Print Network (OSTI)

?? For my thesis, I conducted experiments to investigate superconductivity and superconducting proximity effect in carbon nanotubes. The measurements are carried out on carbon nanotube… (more)

Yang, Yanfei

2010-01-01T23:59:59.000Z

209

The superconductivity of some intermetallic compounds  

Science Conference Proceedings (OSTI)

The W-Os, Re-W, Re-Mo, Re-Hf, and Mo-Hf binary systems were investigated for superconductivity down to 1°K. Several new superconducting regions were found with the most significant occurring in the primary and terminal solid-solution alloys. The ...

R. D. Blaugher; A. Taylor; J. K. Hulm

1962-01-01T23:59:59.000Z

210

Design Concepts for a Superconducting Cable  

Science Conference Proceedings (OSTI)

Superconducting cables carry higher currents and, depending upon the design, can experience substantially lower transmission losses than conventional cables. This report discusses previous approaches to designing superconducting cables, describes the technical issues that must be considered when designing a high-temperature superconductor (HTS) cable, and presents several design concepts for an HTS cable.

1994-09-28T23:59:59.000Z

211

Correlational analysis of superconducting mixed copper oxides  

Science Conference Proceedings (OSTI)

A unifying structural scheme of all layered superconducting cuprates is proposed. The paper is a review based on a three level correlational analysis of the behaviour of one compound, of a homologous series and a third interseries analysis, revealing ... Keywords: correlational analysis, homologous series, layered cuprates, superconductivity

Cristina Zarioiu; V. G. Lascu; Lidia Petrova; Anca Novac

2008-06-01T23:59:59.000Z

212

Stripes and superconductivity in cuprate superconductors  

E-Print Network (OSTI)

One type of order that has been observed to compete with superconductivity in cuprates involves alternating charge and antiferromagnetic stripes. Recent neutron scattering studies indicate that the magnetic excitation spectrum of a stripe-ordered sample is very similar to that observed in superconducting samples. In fact, it now appears that there may be a universal magnetic spectrum for the cuprates. One likely implication of this universal spectrum is that stripes of a dynamic form are present in the superconducting samples. On cooling through the superconducting transition temperature, a gap opens in the magnetic spectrum, and the weight lost at low energy piles up above the gap; the transition temperature is correlated with the size of the spin gap. Depending on the magnitude of the spin gap with respect to the magnetic spectrum, the enhanced magnetic scattering at low temperature can be either commensurate or incommensurate. Connections between stripe correlations and superconductivity are discussed.

J. M. Tranquada

2005-01-01T23:59:59.000Z

213

STRIPES AND SUPERCONDUCTIVITY IN CUPRATE SUPERCONDUCTORS  

SciTech Connect

One type of order that has been observed to compete with superconductivity in cuprates involves alternating charge and antiferromagnetic stripes. Recent neutron scattering studies indicate that the magnetic excitation spectrum of a stripe-ordered sample is very similar to that observed in superconducting samples. In fact, it now appears that there may be a universal magnetic spectrum for the cuprates. One likely implication of this universal spectrum is that stripes of a dynamic form are present in the superconducting samples. On cooling through the superconducting transition temperature, a gap opens in the magnetic spectrum, and the weight lost at low energy piles up above the gap; the transition temperature is correlated with the size of the spin gap. Depending on the magnitude of the spin gap with respect to the magnetic spectrum, the enhanced magnetic scattering at low temperature can be either commensurate or incommensurate. Connections between stripe correlations and superconductivity are discussed.

TRANQUADA, J.M.

2005-08-22T23:59:59.000Z

214

Applications of superconductivity in electric power systems  

DOE Green Energy (OSTI)

Major applications of superconductivity to power systems are considered. The state of the art of materials and refrigeration developments that are necessary for these applications is reviewed. Specific applications including superconducting cables for power transmission and superconducting magnetics for MHD generators, for energy storage, and for magnetically-confined fusion power generation are discussed in terms of their advantages and the progress being made toward introducing the various devices into real situations. It is concluded that the feasibility of superconducting devices is assured, and that, although their performance, reliability, and cost effectiveness for use in power generation, transmission, and storage remain to be proven, it is reasonable to expect that superconductivity can make it in the real world. (LCL)

Keller, W.E.

1976-01-01T23:59:59.000Z

215

Free-standing oxide superconducting articles  

DOE Patents (OSTI)

A substrate-free, free-standing epitaxially oriented superconductive film including a layer of a template material and a layer of a ceramic superconducting material is provided together with a method of making such a substrate-free ceramic superconductive film by coating an etchable material with a template layer, coating the template layer with a layer of a ceramic superconductive material, coating the layer of ceramic superconductive material with a protective material, removing the etchable material by an appropriate means so that the etchable material is separated from a composite structure including the template lay This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

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

1993-01-01T23:59:59.000Z

216

Microelectronic superconducting crossover and coil  

DOE Patents (OSTI)

A microelectronic component comprising a crossover is provided comprising a substrate, a first high T.sub.c superconductor thin film, a second insulating thin film comprising SrTiO.sub.3 ; and a third high T.sub.c superconducting film which has strips which crossover one or more areas of the first superconductor film. An in situ method for depositing all three films on a substrate is provided which does not require annealing steps and which can be opened to the atmosphere between depositions.

Wellstood, Frederick C. (Berkeley, CA); Kingston, John J. (Oakland, CA); Clarke, John (Berkeley, CA)

1994-01-01T23:59:59.000Z

217

Microelectronic superconducting crossover and coil  

DOE Patents (OSTI)

A microelectronic component comprising a crossover is provided comprising a substrate, a first high T[sub c] superconductor thin film, a second insulating thin film comprising SrTiO[sub 3]; and a third high T[sub c] superconducting film which has strips which crossover one or more areas of the first superconductor film. An in situ method for depositing all three films on a substrate is provided which does not require annealing steps and which can be opened to the atmosphere between depositions. 13 figures.

Wellstood, F.C.; Kingston, J.J.; Clarke, J.

1994-03-01T23:59:59.000Z

218

Catch-Disperse-Release Readout for Superconducting Qubits  

E-Print Network (OSTI)

We analyze a single-shot readout for superconducting qubits via the controlled catch, dispersion, and release of a microwave field. A tunable coupler is used to decouple the microwave resonator from the transmission line during the dispersive qubit-resonator interaction, thus circumventing damping from the Purcell effect. We show that if the qubit frequency tuning is sufficiently adiabatic, a fast high-fidelity qubit readout is possible, even in the strongly nonlinear dispersive regime. Interestingly, the Jaynes-Cummings nonlinearity leads to the quadrature squeezing of the resonator field below the standard quantum limit, resulting in a significant decrease of the measurement error.

Eyob A. Sete; Andrei Galiautdinov; Eric Mlinar; John M. Martinis; Alexander N. Korotkov

2013-02-27T23:59:59.000Z

219

Superconducting magnet development program progress report, July 1974--June 1975  

SciTech Connect

During FY 1975, the superconducting magnet development program at the Lawrence Livermore Laboratory was primarily directed toward the development of multifilamentary Nb$sub 3$Sn conductor for large CTR machines. It was secondarily concerned with preliminary work for the MX experiment and with the acquisition of additional testing facilities. Among the significant achievements was the construction and operation of a 27-cm-bore coil to its short-sample limit of 7-T at the windings. The coil was wound with a 100-m length of 67,507- filament Nb$sub 3$Sn conductor. (auth)

Cornish, D.N.; Harvey, A.R.; Nelson, R.L.; Taylor, C.E.; Zbasnik, J.P.

1975-10-24T23:59:59.000Z

220

Superconducting coil and method of stress management in a superconducting coil  

DOE Patents (OSTI)

A superconducting coil (12) having a plurality of superconducting layers (18) is provided. Each superconducting layer (18) may have at least one superconducting element (20) which produces an operational load. An outer support structure (24) may be disposed outwardly from the plurality of layers (18). A load transfer system (22) may be coupled between at least one of the superconducting elements (20) and the outer support structure (24). The load transfer system (22) may include a support matrix structure (30) operable to transfer the operational load from the superconducting element (20) directly to the outer support structure (24). A shear release layer (40) may be disposed, in part, between the superconducting element (20) and the support matrix structure (30) for relieving a shear stress between the superconducting element (20) and the support matrix structure (30). A compliant layer (42) may also be disposed, in part, between the superconducting element (20) and the support matrix structure (30) for relieving a compressive stress on the superconducting element (20).

McIntyre, Peter M. (College Station, TX); Shen, Weijun (Oak Ridge, TN); Diaczenko, Nick (College Station, TX); Gross, Dan A. (College Station, TX)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Reassessment of Superconducting Magnetic Energy Storage (SMES) Transmission System Benefits  

Science Conference Proceedings (OSTI)

This report reassesses the benefits of superconducting magnetic energy storage (SMES) for enhancing transmission system performance.

2002-03-21T23:59:59.000Z

222

Method for making mirrored surfaces comprising superconducting material  

DOE Patents (OSTI)

Superconducting mirror surfaces are provided by forming a mirror surface from a material which is superconductive at a temperature above about 40 K and adjusting the temperature of the surface to that temperature at which the material is superconducting. The mirror surfaces are essentially perfect reflectors for electromagnetic radiation with photon energy less than the superconducting band gap.

Early, J.T.; Hargrove, R.S.

1989-12-12T23:59:59.000Z

223

High Temperature Superconducting Underground Cable  

SciTech Connect

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

224

CRITICAL FIELD FOR SUPERCONDUCTIVITY AND LOW-TEMPERATURE NORMAL-STATE HEAT CAPACITY OF TUNGSTEN  

E-Print Network (OSTI)

y CRITICAL FIELD FOR SUPERCONDUCTIVITY AND LOW-TEMPERATURECritical Field for Superconductivity and Low-Temperaturemagnetic field for superconductivity In tungsten from 5.5 to

Triplett, B.B.

2008-01-01T23:59:59.000Z

225

Superconductivity  

Science Conference Proceedings (OSTI)

Add to Cart, Image, Click on Title to view details, Member (Student) Price, Non- member Price. Available at wiley.com, Advanced Materials for Energy Conversion ...

226

Basic Research Needs for Superconductivity. Report of the Basic Energy Sciences Workshop on Superconductivity, May 8-11, 2006  

SciTech Connect

As an energy carrier, electricity has no rival with regard to its environmental cleanliness, flexibility in interfacing with multiple production sources and end uses, and efficiency of delivery. In fact, the electric power grid was named ?the greatest engineering achievement of the 20th century? by the National Academy of Engineering. This grid, a technological marvel ingeniously knitted together from local networks growing out from cities and rural centers, may be the biggest and most complex artificial system ever built. However, the growing demand for electricity will soon challenge the grid beyond its capability, compromising its reliability through voltage fluctuations that crash digital electronics, brownouts that disable industrial processes and harm electrical equipment, and power failures like the North American blackout in 2003 and subsequent blackouts in London, Scandinavia, and Italy in the same year. The North American blackout affected 50 million people and caused approximately $6 billion in economic damage over the four days of its duration. Superconductivity offers powerful new opportunities for restoring the reliability of the power grid and increasing its capacity and efficiency. Superconductors are capable of carrying current without loss, making the parts of the grid they replace dramatically more efficient. Superconducting wires carry up to five times the current carried by copper wires that have the same cross section, thereby providing ample capacity for future expansion while requiring no increase in the number of overhead access lines or underground conduits. Their use is especially attractive in urban areas, where replacing copper with superconductors in power-saturated underground conduits avoids expensive new underground construction. Superconducting transformers cut the volume, weight, and losses of conventional transformers by a factor of two and do not require the contaminating and flammable transformer oils that violate urban safety codes. Unlike traditional grid technology, superconducting fault current limiters are smart. They increase their resistance abruptly in response to overcurrents from faults in the system, thus limiting the overcurrents and protecting the grid from damage. They react fast in both triggering and automatically resetting after the overload is cleared, providing a new, self-healing feature that enhances grid reliability. Superconducting reactive power regulators further enhance reliability by instantaneously adjusting reactive power for maximum efficiency and stability in a compact and economic package that is easily sited in urban grids. Not only do superconducting motors and generators cut losses, weight, and volume by a factor of two, but they are also much more tolerant of voltage sag, frequency instabilities, and reactive power fluctuations than their conventional counterparts. The challenge facing the electricity grid to provide abundant, reliable power will soon grow to crisis proportions. Continuing urbanization remains the dominant historic demographic trend in the United States and in the world. By 2030, nearly 90% of the U.S. population will reside in cities and suburbs, where increasingly strict permitting requirements preclude bringing in additional overhead access lines, underground cables are saturated, and growth in power demand is highest. The power grid has never faced a challenge so great or so critical to our future productivity, economic growth, and quality of life. Incremental advances in existing grid technology are not capable of solving the urban power bottleneck. Revolutionary new solutions are needed ? the kind that come only from superconductivity.

Sarrao, J.; Kwok, W-K; Bozovic, I.; Mazin, I.; Seamus, J. C.; Civale, L.; Christen, D.; Horwitz, J.; Kellogg, G.; Finnemore, D.; Crabtree, G.; Welp, U.; Ashton, C.; Herndon, B.; Shapard, L.; Nault, R. M.

2006-05-11T23:59:59.000Z

227

RHIC Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

228

Superconducting Magnet Division | Brookhaven National Laboratory  

NLE Websites -- All DOE Office Websites (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,

229

New Science with the APS Superconducting Undulator  

NLE Websites -- All DOE Office Websites (Extended Search)

| 2007 | 2006 | 2005 2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed New Science with the APS Superconducting Undulator JULY 24, 2013 Bookmark and Share The Nature...

230

MAGNETIC DESIGN OF A SUPERCONDUCTING AGS SNAKE*  

NLE Websites -- All DOE Office Websites (Extended Search)

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...

231

Helical Magnets Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC, the basic construction unit is a superconducting dipole magnet producing a four tesla dipole field that rotates through 360 degrees in a length of 2.4 meters. The magnets...

232

Bipolaron Model of Superconductivity in Chalcogenide Glasses  

E-Print Network (OSTI)

In this paper we propose a small bipolaron model for the superconductivity in the Chalcogenide glasses (c-As2Te3 and c-GeTe). The results are agree with the experiments.

Liang-You Zheng; Bo-Cheng Wang; Shan T. Lai

2010-10-25T23:59:59.000Z

233

Magnetism and superconductivity of heavy fermion matter  

E-Print Network (OSTI)

The interplay of magnetism and unconventional superconductivity (d singlet wave or p triplet wave) in strongly correlated electronic system (SCES) is discussed with recent examples found in heavy fermion compounds. A short presentation is given on the formation of the heavy quasiparticle with the two sources of a local and intersite enhancement for the effective mass. Two cases of the coexistence or repulsion of antiferromagnetism and superconductivity are given with CeIn3 and CeCoIn5. A spectacular example is the emergence of superconductivity in relatively strong itinerant ferromagnets UGe2 and URhGe. The impact of heavy fermion matter among other SCES as organic conductor or high TC oxide is briefly pointed out. Key words: heavy fermion, superconductivity, antiferromagnetism, ferromagnetism

J. Flouquet A; G. Knebel A; D. Braithwaite A; D. Aoki B; J. P. Brison C; F. Hardy A; A. Huxley A; S. Raymond A; B. Salce A; I. Sheikin D

2005-01-01T23:59:59.000Z

234

Degreasing and cleaning superconducting RF Niobium cavities  

Science Conference Proceedings (OSTI)

The purpose and scope of this report is to detail the steps necessary for degreasing and cleaning of superconducting RF Niobium cavities in the A0 clean room. It lists the required equipment and the cleaning procedure.

Rauchmiller, Michael; Kellett, Ron; /Fermilab

2011-09-01T23:59:59.000Z

235

Publications | Ramesh Gupta | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Symposium on Superconductivity (ISS2012) in Tokyo, Japan, December 3-5, 2012. HTS Magnet R&D at BNL (pdf), LTHFSW2012 at Napa, CA, November 5-7, 2012 High Field Solenoid Program...

236

Near-zero modes in superconducting graphene  

E-Print Network (OSTI)

Vortices in the simplest superconducting state of graphene contain very-low-energy excitations whose existence is connected to an index theorem that applies strictly to an approximate form of the relevant Bogoliubov–de ...

Ghaemi, Pouyan

237

Superconductivity for electric power systems: Program overview  

SciTech Connect

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

238

Cooling arrangement for a superconducting coil  

DOE Patents (OSTI)

A superconducting device is disclosed, such as a superconducting rotor for a generator or motor. A vacuum enclosure has an interior wall surrounding a cavity containing a vacuum. A superconductive coil is placed in the cavity. A generally-annularly-arranged, thermally-conductive sheet has an inward-facing surface contacting generally the entire outward-facing surface of the superconductive coil. A generally-annularly-arranged coolant tube contains a cryogenic fluid and contacts a generally-circumferential portion of the outward-facing surface of the sheet. A generally-annularly-arranged, thermally-insulative coil overwrap generally circumferentially surrounds the sheet. The coolant tube and the inward-facing surface of the coil overwrap together contact generally the entire outward-facing surface of the sheet. 3 figs.

Herd, K.G.; Laskaris, E.T.

1998-06-30T23:59:59.000Z

239

Electromagnetic Modelling of Superconducting Sensor Designs  

E-Print Network (OSTI)

DEPARTMENT OF MATERIALS SCIENCE AND METALLURGY Electromagnetic Modelling of Superconducting Sensor Designs Guido Gerra Clare Hall, University of Cambridge 1 Preface The present dissertation has been submitted... and for all the moments they have shared with me. 4 Abstract The problem of design optimisation of thin film direct current Superconducting QUantum Interference Device (SQUID) magnetometers made of YBCO (YBa2Cu3O7-x) was considered. The inductances...

Gerra, Guido

240

Dissipative hydride precipitates in superconducting niobium cavities  

Science Conference Proceedings (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

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Passive energy dump for superconducting coil protection  

DOE Patents (OSTI)

The patent describes a passive resistance type energy dump for the protection of the coils of a superconducting magnet. Insertion heaters are immersed in a rigid container filled with a fusible alloy. The energy dump is connected across the coils of the superconducting magnet wherein individual heater elements are connected singly to the windings or otherwise according to the energy dumping requirements upon transition of the magnet to a normal state.

Luton, J.N. Jr.

1973-01-16T23:59:59.000Z

242

Architecture for high critical current superconducting tapes  

DOE Patents (OSTI)

Improvements in critical current capacity for superconducting film structures are disclosed and include the use of, e.g., multilayer YBCO structures where individual YBCO layers are separated by a layer of an insulating material such as CeO.sub.2 and the like, a layer of a conducting material such as strontium ruthenium oxide and the like or by a second superconducting material such as SmBCO and the like.

Jia, Quanxi (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM)

2002-01-01T23:59:59.000Z

243

Superconductive microstrip exhibiting negative differential resistivity  

DOE Patents (OSTI)

A device capable of exhibiting negative differential electrical resistivity over a range of values of current and voltage is formed by vapor- depositing a thin layer of a material capable of exhibiting superconductivity on an insulating substrate, establishing electrical connections at opposite ends of the deposited strip, and cooling the alloy into its superconducting range. The device will exhibit negative differential resistivity when biased in the current- induced resistive state.

Huebener, R.P.; Gallus, D.E.

1975-10-28T23:59:59.000Z

244

Armored spring-core superconducting cable and method of construction  

DOE Patents (OSTI)

An armored spring-core superconducting cable (12) is provided. The armored spring-core superconducting cable (12) may include a spring-core (20), at least one superconducting strand (24) wound onto the spring-core (20), and an armored shell (22) that encases the superconducting strands (24). The spring-core (20) is generally a perforated tube that allows purge gases and cryogenic liquids to be circulated through the armored superconducting cable (12), as well as managing the internal stresses within the armored spring-core superconducting cable (12). The armored shell (22) manages the external stresses of the armored spring-core superconducting cable (12) to protect the fragile superconducting strands (24). The armored spring-core superconducting cable (12) may also include a conductive jacket (34) formed outwardly of the armored shell (22).

McIntyre, Peter M. (611 Montclair, College Station, TX 77840); Soika, Rainer H. (1 Hensel, #X4C, College Station, TX 77840)

2002-01-01T23:59:59.000Z

245

Solution of thin film magnetization problems in type-II superconductivity  

Science Conference Proceedings (OSTI)

Keywords: critical current, numerical solution, superconductivity, thin film, variational inequality

Leonid Prigozhin

1998-07-01T23:59:59.000Z

246

Photon emission near superconducting bodies  

Science Conference Proceedings (OSTI)

We study the photon emission due to a magnetic spin-flip transition of a two-level atom in the vicinity of a dielectric body such as a normal conducting metal or a superconductor. For temperatures below the transition temperature T{sub c} of a superconductor, the corresponding spin-flip lifetime is boosted by several orders of magnitude as compared to the case of a normal conducting body. Numerical results of an exact formulation are also compared to a previously derived approximative analytical expression for the spin-flip lifetime, and we find excellent agreement. We present results on how the spin-flip lifetime depends on the temperature T of a superconducting body as well as its thickness H. Finally, we study how nonmagnetic impurities as well as possible Eliashberg strong-coupling effects influence the spin-flip rate. It is found that nonmagnetic impurities as well as strong-coupling effects have no dramatic impact on the spin-flip lifetime.

Skagerstam, Bo-Sture K.; Rekdal, Per Kristian [Department of Physics, The Norwegian University of Science and Technology, N-7491 Trondheim (Norway)

2007-11-15T23:59:59.000Z

247

Some elementary theoretical considerations concerning superconductivity of superimposed metallic films  

Science Conference Proceedings (OSTI)

A microscopic theory of superconductivity of superimposed metallic films is proposed, based on the fact that thee lectron pair correlation function penetrates into a normal metal where the electron-electron interaction would not by itself produce a superconducting ...

L. N. Cooper

1962-01-01T23:59:59.000Z

248

High Temperature Superconductivity in Cuprates: a model  

E-Print Network (OSTI)

A model is proposed such that quasi-particles (electrons or holes) residing in the CuO2 planes of cuprates may interact leading to metallic or superconducting behaviors. The metallic phase is obtained when the quasi-particles are treated as having classical kinetic energies and the superconducting phase occurs when the quasi-particles are taken as extremely relativistic objects. The interaction between both kinds of particles is provided by a force dependent-on-velocity. In the case of the superconducting behavior, the motion of apical oxygen ions provides the glue to establish the Cooper pair. The model furnishes explicit relations for the Fermi velocity, the perpendicular and the in-plane coherence lengths, the zero-temperature energy gap, the critical current density, the critical parallel and perpendicular magnetic fields. All these mentioned quantities are expressed in terms of fundamental physical constants as: charge and mass of the electron, light velocity in vacuum, Planck constant, electric permittivity of the vacuum. Numerical evaluation of these quantities show that their values are close those found for the superconducting YBaCuO, leading to think the model as being a possible scenario to explain superconductivity in cuprates.

P. R. Silva

2010-07-16T23:59:59.000Z

249

Superconductivity in bulk ultrafine-grained metals prepared by high ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 2014 TMS Annual Meeting & Exhibition. Symposium , Ultrafine Grained Materials VIII. Presentation Title, Superconductivity in bulk ...

250

RECENT ADVANCES IN THE TECHNOLOGY OF SUPERCONDUCTING ACCELERATOR MAGNETS  

E-Print Network (OSTI)

Accelerator Magnets,· Brookhaven National Laboratory,in Superconducting Magnets,- Brookhaven National Laboratory,Accelerator Magnet Wire," Brookhaven National Laboratory,

Taylor, C.E.

2010-01-01T23:59:59.000Z

251

Iron-based Materials May Unlock Superconductivity's Secrets  

Science Conference Proceedings (OSTI)

... wide use in next-generation systems for storing, distributing and using electricity. ... whose appearance shatters the fragile superconductive state. ...

2011-04-26T23:59:59.000Z

252

Proceedings of 2009 KEPRI-EPRI Joint Superconductivity Conference  

Science Conference Proceedings (OSTI)

The Electric Power Research Institute (EPRI) and Korea Electric Power Research Institute (KEPRI) held the 2009 KEPRI-EPRI Joint Superconductivity Conference on November 1618, 2009 in Daejeon, Korea at KEPRIs facilities. The conference was the ninth in EPRIs series of annual superconductivity conferences. KEPRI, which is the research center of Korea Electric Power Corporation, cosponsored the event with EPRIs Superconductivity Program. The Korea Institute of Applied Superconductivity and Cryogenics was th...

2010-02-25T23:59:59.000Z

253

Microsoft Word - FCL Testing Report Final.doc  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

at transmission-level voltages. While there is a need to conduct high voltage-current tests, there are a number of experts that believe it may be possible to substitute modeling...

254

Study on the energy criterion of cuprate superconductivity  

E-Print Network (OSTI)

In this paper, we use the variation of spontaneous magnetization to describe the influence of electron holes in cuprate superconductors, and use competitive energy relations to explore the superconductivity rule and energy criterion, on this basis, we can deduce a clear physical image of superconducting phase diagram and superconducting mechanism.

Gu Jiapu

2007-07-07T23:59:59.000Z

255

RHIC Superconducting Accelerator and Electron Cooling Group  

NLE Websites -- All DOE Office Websites (Extended Search)

Organization Chart (PDF) Organization Chart (PDF) Accelerator R&D Division eRHIC R&D Energy Recovery Linac Photocathode R&D Superconducting RF Electron Cooling LARP Center for Accelerator Science and Education C-AD Accelerator R&D Division Superconducting RF Group Group Headed By: Sergey Belomestnykh This web site presents information on the Superconducting Accelerator and RHIC Electron Cooling Group, which is in the Accelerator R&D Division of the Collider-Accelerator Department of Brookhaven National Laboratory. Work is supported mainly by the Division of Nuclear Physics of the US Department of Energy. Upcoming Events: TBD Most recent events: 56 MHz 2nd External Review, March 8-9, 2011 External Review of the Energy Recovery Linac, February 17-18, 2010. Report of the Review Committee

256

J-PARC Correctors | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

257

Superconducting magnetic shielding apparatus and method  

DOE Patents (OSTI)

Disclosed is a method and apparatus for providing magnetic shielding around a working volume. The apparatus includes a hollow elongated superconducting shell or cylinder having an elongated low magnetic pinning central portion, and two high magnetic pinning end regions. Transition portions of varying magnetic pinning properties are interposed between the central and end portions. The apparatus further includes a solenoid substantially coextensive with and overlying the superconducting cylinder, so as to be magnetically coupled therewith. The method includes the steps passing a longitudinally directed current through the superconducting cylinder so as to depin magnetic reservoirs trapped in the cylinder. Next, a circumferentially directed current is passed through the cylinder, while a longitudinally directed current is maintained. Depinned magnetic reservoirs are moved to the end portions of the cylinder, where they are trapped.

Clem, J.R.

1982-07-09T23:59:59.000Z

258

Superconducting magnetic shielding apparatus and method  

DOE Patents (OSTI)

Disclosed are a method and apparatus for providing magnetic shielding around a working volume. The apparatus includes a hollow elongated superconducting shell or cylinder having an elongated low magnetic pinning central portion, and two high magnetic pinning end regions. Transition portions of varying magnetic pinning properties are interposed between the central and end portions. The apparatus further includes a solenoid substantially coextensive with and overlying the superconducting cylinder, so as to be magnetically coupled therewith. The method includes the steps passing a longitudinally directed current through the superconducting cylinder so as to depin magnetic reservoirs trapped in the cylinder. Next, a circumferentially directed current is passed through the cylinder, while a longitudinally directed current is maintained. Depinned magnetic reservoirs are moved to the end portions of the cylinder, where they are trapped. 5 figs.

Clem, J.R.; Clem, J.R.

1983-10-11T23:59:59.000Z

259

Superconducting magnetic shielding apparatus and method  

DOE Patents (OSTI)

Disclosed is a method and apparatus for providing magnetic shielding around a working volume. The apparatus includes a hollow elongated superconducting shell or cylinder having an elongated low magnetic pinning central portion, and two high magnetic pinning end regions. Transition portions of varying magnetic pinning properties are interposed between the central and end portions. The apparatus further includes a solenoid substantially coextensive with and overlying the superconducting cylinder, so as to be magnetically coupled therewith. The method includes the steps passing a longitudinally directed current through the superconducting cylinder so as to depin magnetic reservoirs trapped in the cylinder. Next, a circumferentially directed current is passed through the cylinder, while a longitudinally directed current is maintained. Depinned magnetic reservoirs are moved to the end portions of the cylinder, where they are trapped.

Clem, John R. (Ames, IA); Clem, John R. (Ames, IA)

1983-01-01T23:59:59.000Z

260

Improved Superconducting Wire for Wind Generators: Superconducting Wires for Direct-Drive Wind Generators  

SciTech Connect

REACT Project: Brookhaven National Laboratory will develop a low-cost superconducting wire that could be used in high-power wind generators. Superconducting wire currently transports 600 times more electric current than a similarly sized copper wire, but is significantly more expensive. Brookhaven National Laboratory will develop a high-performance superconducting wire that can handle significantly more electrical current, and will demonstrate an advanced manufacturing process that has the potential to yield a several-fold reduction in wire costs while using a using negligible amount of rare earth material. This design has the potential to make a wind turbine generator lighter, more powerful, and more efficient, particularly for offshore applications.

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

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

DOE Green Energy (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

262

Superconducting Magnetic Energy Storage in Trapped Field Magnets of High Temperature Superconductors  

Science Conference Proceedings (OSTI)

Superconducting permanent magnets for storing high magnetic fields can serve as a means of energy storage and are useful in applications ranging from motors and generators to fault current limiters and circuit breakers. This report presents the results of experimental studies on high temperature superconductors, which were successfully used to trap a record high stable magnetic field of 83,000 G at 54 K and 100,000 G at 42 K.

1995-12-29T23:59:59.000Z

263

Criterion of stability of the superconducting state  

E-Print Network (OSTI)

In this paper, we propose to draw attention to the stability criterion of the superconductor current state. We use for this purpose the rough systems mathematical apparatus allowing us to relate the desired criterion with the dielectric permittivity of the matter and to identify the type of all possible phonons trajectories in its superconducting state. The state of superconductivity in the matter can be explained only by the phonons behavior peculiarity. And on the basis of the above-mentioned assumption, the corresponding mathematical model is constructed.

Iogann Tolbatov

2009-10-23T23:59:59.000Z

264

Safety and reliability in superconducting MHD magnets  

DOE Green Energy (OSTI)

This compilation adapts studies on safety and reliability in fusion magnets to similar problems in superconducting MHD magnets. MHD base load magnet requirements have been identified from recent Francis Bitter National Laboratory reports and that of other contracts. Information relevant to this subject in recent base load magnet design reports for AVCO - Everett Research Laboratories and Magnetic Corporation of America is included together with some viewpoints from a BNL workshop on structural analysis needed for superconducting coils in magnetic fusion energy. A summary of design codes used in large bubble chamber magnet design is also included.

Laverick, C.; Powell, J.; Hsieh, S.; Reich, M.; Botts, T.; Prodell, A.

1979-07-01T23:59:59.000Z

265

On Color Superconductivity in External Magnetic Field  

E-Print Network (OSTI)

We study color superconductivity in external magnetic field. We discuss the reason why the mixing angles in color-flavor locked (CFL) and two-flavor superconductivity (2SC) phases are different despite the fact that the CFL gap goes to the 2SC gap for $m_s \\to \\infty$. Although flavor symmetry is explicitly broken in external magnetic field, we show that all values of gaps in their coset spaces of possible solutions in the CFL phase are equivalent in external magnetic field.

E. V. Gorbar

2000-01-20T23:59:59.000Z

266

Superconducting phases of f-electron compounds  

E-Print Network (OSTI)

Superconductivity was discovered almost a century ago. Yet, unexpected and fascinating new variants of this same old theme are being found at an increasing pace. This is due to great technical advances in materials preparation and an increasingly more systematic screening of new compounds. Prior to the late 1970s all known superconductors could be accounted for in terms of a condensate of Cooper pairs, where the Cooper pairs form due to electron-phonon interactions. With the discovery of the superfluid phases of 3He this understanding began to change in two ways (Osheroff et al., 1972; Vollhardt and Wölfle, 1990). First, 3He provided an example of non-electron-phonon mediated pairing. Second, it provided an example of a superfluid condensate that breaks additional symmetries. The discovery of heavy-fermion superconductivity as a prime candidate for complex order parameter symmetries and non-electron-phonon mediated pairing in f-electron compounds nearly three decades ago was long recognized as an important turning point in the history of superconductivity. However, progress in heavy fermion superconductivity until not long ago seemed to have been slow. In recent years especially the superconductivity in the cuprates, ruthenates, cobaltates, pyrochlores and ironpnictides received great attention. However, a spectacular series of discoveries and developments in f-electron superconductors took place at the same time. While in the first twelve years following the discovery of heavyfermion superconductivity in CeCu2Si2 only five more heavy fermion superconductors could be identified, over twenty five additional systems have been found in the past fifteen years (see Fig. 1). By now over thirty systems are known, about half of which were discovered in the past five years alone. This illustrates the speed of development the field of f-electron superconductivity has picked up despite its long tradition. As a result there is growing appreciation that superconducting phases of f-electron compounds frequently exist at the border of competing and coexisting forms of electronic order. For the majority of systems, including the original heavy-fermion superconductors, an inarXiv:0905.2625v1

Christian Pfleiderer

2009-01-01T23:59:59.000Z

267

Apparatus for characterizing conductivity of superconducting materials  

DOE Patents (OSTI)

Apparatus and method for noncontact, radio-frequency shielding current characterization of materials. Self- or mutual inductance changes in one or more inductive elements, respectively, occur when materials capable of supporting shielding currents are placed in proximity thereto, or undergo change in resistivity while in place. Such changes can be observed by incorporating the inductor(s) in a resonant circuit and determining the frequency of oscillation or by measuring the voltage induced on a coupled inductive element. The present invention is useful for determining the critical temperature and superconducting transition width for superconducting samples. 10 figures.

Doss, J.D.

1993-12-07T23:59:59.000Z

268

Process Limits on Euclid  

NLE Websites -- All DOE Office Websites (Extended Search)

Process Limits Process Limits Limit Hard Soft core file size (blocks) 0 unlimited data seg size (kbytes) unlimited unlimited scheduling priority 0 0 file size (blocks) unlimited...

269

Prospects for Strong Cavity Quantum Electrodynamics with Superconducting Circuits  

E-Print Network (OSTI)

We propose a realizable architecture using one-dimensional transmission line resonators to reach the strong coupling limit of cavity quantum electrodynamics in superconducting electrical circuits. The vacuum Rabi frequency for the coupling of cavity photons to quantized excitations of an adjacent electrical circuit (qubit) can easily exceed the damping rates of both the cavity and the qubit. This architecture is attractive for quantum computing and control, since it provides strong inhibition of spontaneous emission, potentially leading to greatly enhanced qubit lifetimes, allows high-fidelity quantum non-demolition measurements of the state of multiple qubits, and has a natural mechanism for entanglement of qubits separated by centimeter distances. In addition it would allow production of microwave photon states of fundamental importance for quantum communication.

S. M. Girvin; Ren-Shou Huang; Alexandre Blais; Andreas Wallraff; R. J. Schoelkopf

2003-10-28T23:59:59.000Z

270

Color symmetric superconductivity in a phenomenological QCD model  

E-Print Network (OSTI)

In this paper, we construct a theory of the NJL-type where superconductivity is present, and yet the super-conducting state remains, in the average, color symmetric. This shows that the present approach to color superconductivity is consistent with color singlet-ness. Indeed, quarks are free in the deconfined phase, but the deconfined phase itself is believed to be a color singlet. The usual description of the color superconducting state violates color singlet-ness. On the other hand, the color superconducting state here proposed, is color symmetric in the sense that an arbitrary color rotation leads to an equivalent state, with precisely the same physical properties.

Henrik Bohr; Constança Providência; João da Providência

2009-09-19T23:59:59.000Z

271

Pseudogap and Superconducting Gap in High-Temperature Superconductors  

NLE Websites -- All DOE Office Websites (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.

272

Termination for superconducting power transmission systems  

DOE Patents (OSTI)

This patent relates to a cold, electrical gradient, terminal section for a superconducting cable for alternating current power transmission. A cold electrical gradient section filled with a gaseous coolant acting as an insulator is provided in series with a separate thermal gradient section. (auth)

Forsyth, E.B.; Jensen, J.E.

1975-08-26T23:59:59.000Z

273

Eccentric superconducting RF cavity separator structure  

DOE Patents (OSTI)

Accelerator apparatus having an eccentric-shaped, iris-loaded deflecting cavity for an rf separator for a high energy high momentum, charged particle accelerator beam. In one embodiment, the deflector is superconducting, and the apparatus of this invention provides simplified machining and electron beam welding techniques. Model tests have shown that the electrical characteristics provide the desired mode splitting without adverse effects.

Aggus, John R. (Shoreham, NY); Giordano, Salvatore T. (Port Jefferson, NY); Halama, Henry J. (Shoreham, NY)

1976-01-01T23:59:59.000Z

274

Positive and inverse isotope effect on superconductivity  

E-Print Network (OSTI)

This article improves the BCS theory to include the inverse isotope effect on superconductivity. An affective model can be deduced from the model including electron-phonon interactions, and the phonon-induced attraction is simply and clearly explained on the electron Green function. The focus of this work is on how the positive or inverse isotope effect occurs in superconductors.

Tian De Cao

2009-09-04T23:59:59.000Z

275

Color superconductivity and the strange quark  

E-Print Network (OSTI)

At ultra-high density, matter is expected to form a degenerate Fermi gas of quarks in which there is a condensate of Cooper pairs of quarks near the Fermi surface: color superconductivity. In these proceedings I review some of the underlying physics, and discuss outstanding questions about the phase structure of ultra-dense quark matter.

Mark G Alford

2005-12-01T23:59:59.000Z

276

Active superconducting devices formed of thin films  

DOE Patents (OSTI)

Active superconducting devices are formed of thin films of superconductor which include a main conduction channel which has an active weak link region. The weak link region is composed of an array of links of thin film superconductor spaced from one another by voids and selected in size and thickness such that magnetic flux can propagate across the weak link region when it is superconducting. Magnetic flux applied to the weak link region will propagate across the array of links causing localized loss of superconductivity in the links and changing the effective resistance across the links. The magnetic flux can be applied from a control line formed of a superconducting film deposited coplanar with the main conduction channel and weak link region on a substrate. The devices can be formed of any type to superconductor but are particularly well suited to the high temperature superconductors since the devices can be entirely formed from coplanar films with no overlying regions. The devices can be utilized for a variety of electrical components, including switching circuits, amplifiers, oscillators and modulators, and are well suited to microwave frequency applications.

Martens, Jon S. (Madison, WI); Beyer, James B. (Madison, WI); Nordman, James E. (Madison, WI); Hohenwarter, Gert K. G. (Madison, WI)

1991-05-28T23:59:59.000Z

277

Locating strongly coupled color superconductivity using universality and experiments with trapped ultracold atoms  

E-Print Network (OSTI)

Cold fermionic atoms are known to enter the universal strongly coupled regime as their scattering length $a$ gets large compared to the inter-particle distances. Recent experimental data provide important critical parameters of such system. We argue that quarks may enter the same regime due to marginal binding of diquarks, and if so one can use its universality in order to deduce such properties as the slope of the critical line of color superconductivity, $dT_c/d\\mu$. We further discuss limitations on the critical temperature itself and conclude that it is limited by $T_c<70\\, MeV$.

E. V. Shuryak

2006-06-21T23:59:59.000Z

278

Intrinsic Spin-Orbit Coupling in Superconducting Delta-Doped SrTiO3 Heterostructures  

SciTech Connect

We report the violation of the Pauli limit due to intrinsic spin-orbit coupling in SrTiO{sub 3} heterostructures. Via selective doping down to a few nanometers, a two-dimensional superconductor is formed, geometrically suppressing orbital pair-breaking. The spin-orbit scattering is exposed by the robust in-plane superconducting upper critical field, exceeding the Pauli limit by a factor of 4. Transport scattering times several orders of magnitude higher than for conventional thin film superconductors enables a new regime to be entered, where spin-orbit coupling effects arise non-perturbatively.

Bell, Christopher

2011-08-19T23:59:59.000Z

279

Torsional texturing of superconducting oxide composite articles  

DOE Patents (OSTI)

A method of texturing a multifilamentary article having filaments comprising a desired oxide superconductor or its precursors by torsionally deforming the article is provided. The texturing is induced by applying a torsional strain which is at least about 0.3 and preferably at least about 0.6 at the surface of the article, but less than the strain which would cause failure of the composite. High performance multifilamentary superconducting composite articles having a plurality of low aspect ratio, twisted filaments with substantially uniform twist pitches in the range of about 1.00 inch to 0.01 inch (25 to 0.25 mm), each comprising a textured desired superconducting oxide material, may be obtained using this texturing method. If tighter twist pitches are desired, the article may be heat treated or annealed and the strain repeated as many times as necessary to obtain the desired twist pitch. It is preferred that the total strain applied per step should be sufficient to provide a twist pitch tighter than 5 times the diameter of the article, and twist pitches in the range of 1 to 5 times the diameter of the article are most preferred. The process may be used to make a high performance multifilamentary superconducting article, having a plurality of twisted filaments, wherein the degree of texturing varies substantially in proportion to the radial distance from the center of the article cross-section, and is substantially radially homogeneous at any given cross-section of the article. Round wires and other low aspect ratio multifilamentary articles are preferred forms. The invention is not dependent on the melting characteristics of the desired superconducting oxide. Desired oxide superconductors or precursors with micaceous or semi-micaceous structures are preferred. When used in connection with desired superconducting oxides which melt irreversibly, it provides multifilamentary articles that exhibit high DC performance characteristics and AC performance markedly superior to any currently available for these materials. In a preferred embodiment, the desired superconducting oxide material is BSCCO 2223.

Christopherson, Craig John (Grafton, MA); Riley, Jr., Gilbert N. (Marlborough, MA); Scudiere, John (Bolton, MA)

2002-01-01T23:59:59.000Z

280

Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in these manganites is remarkably similar to that found in high-temperature superconducting copper oxide materials (cuprates). This discovery casts new doubts on any direct link between the pseudogap phase and high-temperature superconductivity and adds fire to the debate over one of the great scientific mysteries of our time: What causes high-temperature superconductivity?

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in these manganites is remarkably similar to that found in high-temperature superconducting copper oxide materials (cuprates). This discovery casts new doubts on any direct link between the pseudogap phase and high-temperature superconductivity and adds fire to the debate over one of the great scientific mysteries of our time: What causes high-temperature superconductivity?

282

Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

Pseudogaps, Polarons, and the Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Wednesday, 26 April 2006 00:00 Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in these manganites is remarkably similar to that found in high-temperature superconducting copper oxide materials (cuprates). This discovery casts new doubts on any direct link between the pseudogap phase and high-temperature superconductivity and adds fire to the debate over one of the great scientific mysteries of our time: What causes high-temperature superconductivity?

283

ORNL Publishes Study on Superconducting Wire Performance | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ORNL Publishes Study on Superconducting Wire Performance ORNL Publishes Study on Superconducting Wire Performance ORNL Publishes Study on Superconducting Wire Performance August 23, 2013 - 4:06pm Addthis The Department of Energy's Oak Ridge National Laboratory (ORNL) recently released a new study on advances in superconducting wire technology. A team led by ORNL's Amit Goyal demonstrated that the ability to control nanoscale imperfections in superconducting wires results in materials with excellent and customized performance. The team's findings are published in Nature Publishing Group's Scientific Reports. The full press release and link to the new report are available on ORNL's website. Dr. Goyal, a high temperature superconductivity (HTS) research at ORNL, won the Department's 2011 E.O. Lawrence Award in the inaugural category of

284

Color superconductivity with determinant interaction in strange quark matter  

E-Print Network (OSTI)

We investigate the effect of six fermion determinant interaction on color superconductivity as well as on chiral symmetry breaking. Coupled mass gap equations and the superconducting gap equation are derived through the minimisation of the thermodynamic potential. The effect of nonzero quark -- antiquark condensates on the superconducting gap is derived. This becomes particularly relevant for the case of 2-flavor superconducting matter with unpaired strange quarks in the diquark channel. While the effect of six fermion interaction leads to an enhancement of u-d superconductivity, due to nonvanishing strange quark--antiquark condensates, such an enhancement will be absent at higher densities for u-s or d-s superconductivity due to early (almost) vanishing of light quark-- antiquark condensates.

Amruta Mishra; Hiranmaya Mishra

2006-05-21T23:59:59.000Z

285

Superconductivity with stripes | Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Science Computing, Environment & Life Sciences Energy Engineering & Systems Analysis Photon Sciences Physical Sciences & Engineering Energy Frontier Research Centers Science Highlights Postdoctoral Researchers The brightness and energy of X-ray beams are critical properties for research. The APS Upgrade will make our X-ray beams brighter, meaning more X-rays can be focused onto a smaller, laser-like spot, allowing researchers to gather more data in greater detail in less time. Superconductivity with stripes November 12, 2013 Tweet EmailPrint The physics of low-temperature superconductivity is fairly well understood, but the ultimate goal of achieving the phenomenon at much higher temperatures remains tantalizingly elusive. The most promising high-temperature superconductor candidates are generally considered to be

286

Energy Programs | Center for Emergent Superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

Center for Emergent Superconductivity (CES) Center for Emergent Superconductivity (CES) The mission of the CES is to advance the frontier of understanding and control of the materials, mechanisms, and critical currents of superconductors, including existing and new materials, and to communicate Center and other research results throughout national and international communities. More... Principal Investigators CES News Publications Recent CES Presentations EFRC Acknowledgements Reference Document (pdf) Guide to EFRC Science Review Documents (pdf) CES-EFRC Materials Catalog (restricted) CES-EFRC April 2009 Kickoff Meeting (restricted) CES-EFRC 2010 Winter Workshop (restricted) CES Fall Workshop: 2013 | 2012 | 2011 | 2010 April 2, 2012 Review (restricted) Story Archives Recent News atomic-scale microscopy Opposing Phenomena Possible Key to High-Efficiency Electricity Delivery

287

Energy Extraction for the LHC Superconducting Circuits  

E-Print Network (OSTI)

The superconducting magnets of the LHC will be powered in about 1700 electrical circuits. The energy stored in circuits, up to 1.3 GJ, can potentially cause severe damage of magnets, bus bars and current leads. In order to protect the superconducting elements after a resistive transition, the energy is dissipated into a dump resistor installed in series with the magnet chain that is switched into the circuit by opening current breakers. Experiments and simulation studies have been performed to identify the LHC circuits that need energy extraction. The required values of the extraction resistors have been computed. The outcome of the experimental results and the simulation studies are presented and the design of the different energy extraction systems that operate at 600 A and at 13 kA is described.

Dahlerup-Petersen, K; Schmidt, R; Sonnemann, F

2001-01-01T23:59:59.000Z

288

Superconductivity and the BCS-Bogoliubov Theory  

E-Print Network (OSTI)

First, we reformulate the BCS-Bogoliubov theory of superconductivity from the viewpoint of linear algebra. We define the BCS Hamiltonian on $\\mathbb{C}^{2^{2M}}$, where $M$ is a positive integer. We discuss selfadjointness and symmetry of the BCS Hamiltonian as well as spontaneous symmetry breaking. Beginning with the gap equation, we give the well-known expression for the BCS state and find the existence of an energy gap. We also show that the BCS state has a lower energy than the normal state. Second, we introduce a new superconducting state explicitly and show from the viewpoint of linear algebra that this new state has a lower energy than the BCS state. Third, beginning with our new gap equation, we show from the viewpoint of linear algebra that we arrive at the results similar to those in the BCS-Bogoliubov theory.

Shuji Watanabe

2010-06-07T23:59:59.000Z

289

Method of fabricating composite superconducting wire  

DOE Patents (OSTI)

An improvement in the method for preparing composite rods of superconducting alloy and normal metal from which multifilament composite superconducting wire is fabricated by bending longitudinally a strip of normal metal around a rod of superconductor alloy and welding the edges to form the composite rod. After the rods have preferably been provided with a hexagonal cross-sectional shape, a plurality of the rods are stacked into a normal metal extrusion can, sealed and worked to reduce the cross-sectional size and form multifilament wire. Diffusion barriers and high-electrical resistance barriers can easily be introduced into the wire by plating or otherwise coating the faces of the normal metal strip with appropriate materials.

Strauss, Bruce P. (Downers Grove, IL); Reardon, Paul J. (Princeton, NJ); Remsbottom, Robert H. (Middleton, WI)

1977-01-01T23:59:59.000Z

290

High-temperature superconducting current leads  

Science Conference Proceedings (OSTI)

Use of high-temperature superconductors (HTSs) for current leads to deliver power to devices at liquid helium temperature can reduce refrigeration requirements to values significantly below those achievable with conventional leads. HTS leads are now near commercial realization. Argonne National Laboratory (ANL) has developed a sinter-forge process to fabricate current leads from bismuth-based superconductors. The current-carrying capacity of these leads is five times better than that of HTS leads made by a conventional fabrication process. ANL along with Superconductivity, Inc., has developed a 1500 ampere current lead for an existing superconducting magnetic energy storage (SMES) device. With Babcock & Wilcox Company, Argonne is creating 16-kiloampere leads for use in a 0.5 MWh SMES. In a third project Argonne performed characterization testing of a existing, proprietary conduction-cooled lead being developed by Zer Res Corp.

Niemann, R.C.

1995-03-01T23:59:59.000Z

291

High-Temperature Superconductivity Cable Demonstration Projects  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

292

Use of superconductive technology for energy storage and power transmission for large power systems: power parks  

DOE Green Energy (OSTI)

A general review and technology assessment of superconducting magnets for energy storage and superconducting cables for power transmission are presented. It is concluded that the technology is now available for applying superconductivity in the power industry. (TFD)

Keller, W.E.

1977-01-01T23:59:59.000Z

293

Superconducting RF systems for eRHIC  

Science Conference Proceedings (OSTI)

The proposed electron-hadron collider eRHIC will consist of a six-pass 30-GeV electron Energy Recovery Linac (ERL) and one of RHIC storage rings operating with energy up to 250 GeV. The collider design extensively utilizes superconducting RF (SRF) technology in both electron and hadron parts. This paper describes various SRF systems, their requirements and parameters.

Belomestnykh S.; Ben-Zvi, I.; Brutus, J.C.; Hahn, H. et al

2012-05-20T23:59:59.000Z

294

Superconducting Power Equipment: Technology Watch 2012  

Science Conference Proceedings (OSTI)

The demand to transport large quantities of renewable energy from wind, solar, or hydro projects in remote locations to population load centers is increasing worldwide. Improved efficiency and greater power capacity that superconducting cables provide in this application continue to attract interest. In the United States, the Tres Amigas interconnect project, which reportedly will eventually use dc superconductors, is, in part, motivated by the need to transport wind power from west to east. ...

2012-12-20T23:59:59.000Z

295

Specifying and Testing Superconducting Power Equipment  

Science Conference Proceedings (OSTI)

EPRI held a workshop on September 21, 2007 in Hauppauge, New York to discuss what is needed to develop standards and specifications for testing superconducting power equipment. Stakeholders, including developers, equipment manufacturers, and electric utilities, participated in the discussions, which were arranged in a semi-formal setting to promote open dialogue. The U.S. Department of Energy provided assistance with meeting facilitation and recording.

2008-07-22T23:59:59.000Z

296

Holographic Superconductivity with Gauss-Bonnet gravity  

E-Print Network (OSTI)

I review recent work on holographic superconductivity with Einstein-Gauss-Bonnet gravity, and show how the critical temperature of the superconductor depends on both gravitational backreaction and the Gauss-Bonnet parameter, using both analytic and numerical arguments. I also review computations of the conductivity, finding the energy gap, and demonstrating that there is no universal gap ratio, $\\omega_g/T_c$, for these superconductors.

Ruth Gregory

2010-12-07T23:59:59.000Z

297

Compact Superconducting Crabbing and Deflecting Cavities  

SciTech Connect

Recently, new geometries for superconducting crabbing and deflecting cavities have been developed that have significantly improved properties over those the standard TM{sub 110} cavities. They are smaller, have low surface fields, high shunt impedance and, more importantly for some of them, no lower-order-mode with a well-separated fundamental mode. This talk will present the status of the development of these cavities.

De Silva, Payagalage Subashini Uddika [JLAB, Old Dominion U.

2012-09-01T23:59:59.000Z

298

On a Model of Superconductivity and Biology  

E-Print Network (OSTI)

The paper deals with a semilinear integrodifferential equation that characterizes several dissipative models of Viscoelasticity, Biology and Superconductivity. The initial - boundary problem with Neumann conditions is analyzed. When the source term F is a linear function, then the explicit solution is obtained. When F is non linear, some results on existence, uniqueness and a priori estimates are deduced. As example of physical model the reaction - diffusion system of Fitzhugh Nagumo is considered.

Monica De Angelis

2012-03-02T23:59:59.000Z

299

High temperature superconductivity in metallic region near Mott transition  

E-Print Network (OSTI)

The spin-singlet superconductivity without phonons is examined in consideration of correlations on an extended Hubbard model. It is shown that the superconductivity requires not only the total correlation should be strong enough but also the density of state around Fermi energy should be large enough, which shows that the high temperature superconductivity could only be found in the metallic region near the Mott metal insulator transition (MIT). Other properties of superconductors are also discussed on these conclusions.

Tian De Cao

2009-06-11T23:59:59.000Z

300

Method for manufacturing a rotor having superconducting coils  

DOE Patents (OSTI)

A method and apparatus for manufacturing a rotor for use with a rotating machine is provided that employs a superconducting coil on the rotor. An adhesive is applied to an outer surface of the rotor body, which may include a groove disposed within an outer surface of the rotor body. A superconducting coil is then mounted onto the rotor body such that the adhesive bonds the superconducting coil to the rotor body.

Driscoll, David I. (South Euclid, OH); Shoykhet, Boris A. (Beachwood, OH)

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Substrates suitable for deposition of superconducting thin films  

DOE Patents (OSTI)

A superconducting system for the lossless transmission of electrical current comprising a thin film of superconducting material Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x epitaxially deposited upon a KTaO.sub.3 substrate. The KTaO.sub.3 is an improved substrate over those of the prior art since the it exhibits small lattice constant mismatch and does not chemically react with the superconducting film.

Feenstra, Roeland (Oak Ridge, TN); Boatner, Lynn A. (Oak Ridge, TN)

1993-01-01T23:59:59.000Z

302

Strategic Intelligence Update: Superconductivity for Power Delivery Applications, April 2013  

Science Conference Proceedings (OSTI)

EPRI’s Strategic Intelligence Update: Superconductivity for Power Delivery Applications newsletter is part of its commitment to keep its members informed on the latest industry news and intelligence. Superconductivity is a rapidly evolving field, and this newsletter—along with EPRI’s annual Technology Watch reports—will closely follow developments in key technologies, R&D programs, demonstrations, deployments, and other superconductivity activities. The ...

2013-04-30T23:59:59.000Z

303

Superconductivity, superfluidity and zero-point oscillations  

E-Print Network (OSTI)

Currently it is thought that in order to explain the phenomenon of superconductivity is necessary to understand the mechanism of formation of electron pairs. However, the paired electrons cannot form a superconducting condensate. They perform disorderly zero-point oscillations and there are no attractive forces in their ensemble. To create a unified ensemble of particles, the pairs must order their zero-point fluctuations so that an attraction between the particles appears. For this reason, the ordering of zero-point oscillations in the electron gas is the cause of superconductivity and the parameters characterizing this order determine the properties of superconductors. The model of condensation of zero-point oscillations creates the possibility to obtain estimates for the critical parameters of elementary superconductors, which are also in the satisfactory agreement with measured data. On the another hand, the phenomenon of superfluidity in He-4 and He-3 can be similarly explained due to the ordering of zero-point fluctuations. Thus it is established that the both related phenomena are based on the same physical mechanism.

B. V. Vasiliev

2010-09-13T23:59:59.000Z

304

Magnetic profiles in ferromagnetic/superconducting superlattices.  

SciTech Connect

The interplay between ferromagnetism and superconductivity has been of longstanding fundamental research interest to scientists, as the competition between these generally mutually exclusive types of long-range order gives rise to a rich variety of physical phenomena. A method of studying these exciting effects is by investigating artificially layered systems, i.e. alternating deposition of superconducting and ferromagnetic thin films on a substrate, which enables a straight-forward combination of the two types of long-range order and allows the study of how they compete at the interface over nanometer length scales. While originally studies focused on low temperature superconductors interchanged with metallic ferromagnets, in recent years the scope has broadened to include superlattices of high T{sub c} superconductors and colossal magnetoresistance oxides. Creating films where both the superconducting as well as the ferromagnetic layers are complex oxide materials with similar crystal structures (Figure 1), allows the creation of epitaxial superlattices, with potentially atomically flat and ordered interfaces.

te Velthuis, S. G. E.; Hoffmann, A.; Santamaria, J.; Materials Science Division; Univ. Complutense de Madrid

2007-02-28T23:59:59.000Z

305

Rotatable superconducting cyclotron adapted for medical use  

DOE Patents (OSTI)

A superconducting cyclotron (10) rotatable on a support structure (11) in an arc of about 180.degree. around a pivot axis (A--A) and particularly adapted for medical use is described. The rotatable support structure (13, 15) is balanced by being counterweighted (14) so as to allow rotation of the cyclotron and a beam (12), such as a subparticle (neutron) or atomic particle beam, from the cyclotron in the arc around a patient. Flexible hose (25) is moveably attached to the support structure for providing a liquified gas which is supercooled to near 0.degree. K. to an inlet means (122) to a chamber (105) around superconducting coils (101, 102). The liquid (34) level in the cyclotron is maintained approximately half full so that rotation of the support structure and cyclotron through the 180.degree. can be accomplished without spilling the liquid from the cyclotron. With the coils vertically oriented, each turn of the winding is approximately half immersed in liquid (34) and half exposed to cold gas and adequate cooling to maintain superconducting temperatures in the section of coil above the liquid level is provided by the combination of cold gas/vapor and by the conductive flow of heat along each turn of the winding from the half above the liquid to the half below.

Blosser, Henry G. (East Lansing, MI); Johnson, David A. (Williamston, MI); Riedel, Jack (East Lansing, MI); Burleigh, Richard J. (Berkeley, CA)

1985-01-01T23:59:59.000Z

306

Vital Tool in Superconductivity Studies | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Short Title Neutron scattering continues as a vital tool in superconductivity studies January 01, 2011 In 2008, the totally unexpected discovery of a New class of superconductors,...

307

On superconductivity of high-spin transition metal compounds  

SciTech Connect

The possibility of Cooper instability in transition metal compounds is established based of the concept of the strong interaction in the same unit cell. The multicomponent scattering amplitude of excitations is calculated. The superconductivity equations are derived for compounds of 3d transition metals. It is shown that in the pole approximation, the superconductivity equations can be reduced to the multicomponent superconductivity equations with preset BCS constants. A method is developed for calculating one-orbital constants and constants with different orbitals as functions of the total spin. The concentration ranges of superconducting ordering are obtained for one-orbital equations.

Zaitsev, R. O., E-mail: Zaitsev_rogdai@mail.ru [Moscow Institute of Physics and Technology (State University) (Russian Federation)

2011-11-15T23:59:59.000Z

308

BSA 08-04: High Temperature Interfacial Superconductivity  

Cuprate superconductors exhibit relatively high transition temperatures, but their unit cells are complex and large. Localizing a superconducting layer to a small ...

309

"ONE HUNDRED YEARS OF SUPERCONDUCTIVITY", Dr. Michael Norman...  

NLE Websites -- All DOE Office Websites (Extended Search)

March 10, 2012, 9:30am Science On Saturday "ONE HUNDRED YEARS OF SUPERCONDUCTIVITY", Dr. Michael Norman, Materials Science Division, Argonne National Laboratory http:...

310

Superconductivity for Electric Systems: 2008 Annual Peer Review...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

for Electric Systems: 2008 Annual Peer Review Final Report The Office of Electricity Delivery and Energy Reliability's High Temperature Superconductivity (HTS) for...

311

Magnetism and Superconductivity in Ruthenates, Ruthenocuprates, and Other Layered Oxides.  

E-Print Network (OSTI)

??There exist several classes of materials that simultaneously exhibit superconductivity and anomalous magnetic order, where both effects are homogeneous throughout the material. No cohesive explanation… (more)

Smylie, Matthew Passmore

2010-01-01T23:59:59.000Z

312

EFFECTS OF DIMENSIONALITY, SAMPLE TOPOLOGY, AND DISORDER ON SUPERCONDUCTIVITY.  

E-Print Network (OSTI)

??The primary goal of this thesis work is to explore various phenomena related to the effects of dimensionality, sample topology, and disorder on superconductivity, motivated… (more)

Wang, Haohua

2006-01-01T23:59:59.000Z

313

Effects of geometric constraints and sample topology on superconductivity.  

E-Print Network (OSTI)

??The goal of this dissertation is to explore the effects of geometric constraints and sample topology on superconductivity. This work started with an effort to… (more)

Staley, Neal

2012-01-01T23:59:59.000Z

314

Studies in Magnetism and Superconductivity under Extreme Pressure.  

E-Print Network (OSTI)

??Abstract Studies of superconductivity, magnetism and structure under pressure have made important contributions to furthering our understanding of the physical properties of materials. High pressure… (more)

Bi, Wenli

2011-01-01T23:59:59.000Z

315

Type-I superconductivity and neutron star precession  

E-Print Network (OSTI)

Type-I proton superconducting cores of neutron stars break up in a magnetic field into alternating domains of superconducting and normal fluids. We examine two channels of superfluid-normal fluid friction where (i) rotational vortices are decoupled from the non-superconducting domains and the interaction is due to the strong force between protons and neutrons; (ii) the non-superconducting domains are dynamically coupled to the vortices and the vortex motion generates transverse electric fields within them, causing electronic current flow and Ohmic dissipation. The obtained dissipation coefficients are consistent with the Eulerian precession.

Armen Sedrakian

2004-08-25T23:59:59.000Z

316

Superconductivity Efforts at the US Department of Energy (DOE)  

Science Conference Proceedings (OSTI)

The DOE Office of Electricity Delivery and Energy Reliability Superconductivity Program's specific mission is to work in partnership with industry to develop HTS

317

Developing a High-Temperature Superconducting Bulk Magnet for ...  

Science Conference Proceedings (OSTI)

In addition to these well-developed technologies, high-critical temperature superconductors that show superconductivity at liquid nitrogen are also prospective ...

318

Growth and Superconductivity of Pb and Pb-Bi Alloys in the Quantum Regime.  

E-Print Network (OSTI)

??Superconductivity is a collective quantum phenomenon that is inevitably suppressed in reduced dimensionality. Questions of how thin superconducting wires or films can be before they… (more)

Ozer, Mustafa Murat

2006-01-01T23:59:59.000Z

319

Normal zone propagation in superconducting focusing solenoids and related quench protection issues  

SciTech Connect

Superconducting solenoids are increasingly used as focusing lenses in transport channels of proton linear RF accelerators. If these accelerators employ superconducting RF cavities, each focusing lens is usually comprised of three coils connected in series: a main coil, which provides the needed focusing strength, and two bucking coils, that help to reduce magnetic field outside the lens. When a normal zone develops in any of the coils in a focusing lens, it propagates with a direction and a rate which depends on the coil and the specific part of the coil in which the quench first occurred. As a result of this propagation process (quenching), the temperature and/or voltage of parts of the lens can exceed safe limits, thus compromising lens reliability. On the other hand, the negative impact of quench events can be significantly mitigated if an external resistor is used to absorb a part of the energy stored in the magnetic field. This paper presents the main results of a solenoid quench protection study based on computational modeling of normal zone propagation in solenoid lenses being built for a superconducting linear RF accelerator under development at Fermilab.

Terechkine, I.; /Fermilab

2007-06-01T23:59:59.000Z

320

Beam heating studies on an early model is a superconducting cosine theta magnet  

Science Conference Proceedings (OSTI)

Superconducting magnets for accelerators can be accidentally quenched by heat resulting from beam losses in the magnet. The threshold for such quenches is determined by the time structure of the beam loss and by details of the magnet application, construction and cooling. A 4.25 m long superconducting cosine theta dipole magnet, MARK VI, constructed during the research and development phase of the ISABELLE Project at BNL was installed in the 28.5 GeV/c primary proton beam line from the AGS. By energizing the magnet, the proton beam could be deflected into the magnet. The beam intensity required to quench the magnet was observed for different beam sizes and at several values of magnet current up to 2400 A or approximately 70% of the highest magnet operating current. The maximum current was limited by the gas-cooled power lead flow available using pool-boiling helium rather than single phase forced-flow helium at 5 atm for which the magnet system was designed. Details of the experimental setup including the magnet and cryogenic system, the beam-monitoring equipment and instrumentation are described. The measurements are discussed and compared with beam heating measurements made on another superconducting magnet and interpreted using the Cascade Simulation Program, CASIM.

Bozoki, G; Bunce, G; Danby, G; Foelsche, H; Jackson, J; Prodell, A; Soukas, A; Stevens, A; Stoehr, R; Weisenbloom, J

1980-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

A new boson-fermion model of superconductivity  

E-Print Network (OSTI)

It is shown that the superconducting energy gap necessarily lead to the disappearance of some quasi-electrons, thus we suggest a new boson-fermion Hamiltonian to describe superconductivity. The new supercurrent equations are derived with this Hamiltonian. Some new results can be found besides the zero resistance effect, the Meissner effect and the magnetic flux quantum can be explained.

Tian De Cao

2010-10-17T23:59:59.000Z

322

Superconductivity at 35 K in Graphite-Sulfur Composites  

E-Print Network (OSTI)

We report magnetization measurements performed on graphite–sulfur composites which demonstrate a clear superconducting behavior below the critical temperature Tc0 = 35 K. The Meissner-Ochsenfeld effect, screening supercurrents, and magnetization hysteresis loops characteristic of type-II superconductors were measured. The results indicate that the superconductivity occurs in a small sample fraction, possibly related to the sample surface.

R. Ricardo Da Silva; J. H. S. Torres; Y. Kopelevich

2001-01-01T23:59:59.000Z

323

Superconducting magnetic energy storage for asynchronous electrical systems  

DOE Patents (OSTI)

It is an object of the present invention to provide superconducting magnetic energy storage for a plurality of asynchronous electrical systems. It is a further object of the present invention to provide load leveling and stability improvement in a plurality of independent ac systems using a single superconducting magnetic energy storage coil.

Boenig, H.J.

1984-05-16T23:59:59.000Z

324

Superconducting magnetic energy storage for asynchronous electrical systems  

DOE Patents (OSTI)

A superconducting magnetic energy storage coil connected in parallel between converters of two or more ac power systems provides load leveling and stability improvement to any or all of the ac systems. Control is provided to direct the charging and independently the discharging of the superconducting coil to at least a selected one of the ac power systems.

Boenig, Heinrich J. (Los Alamos, NM)

1986-01-01T23:59:59.000Z

325

Pressure induced Superconductivity in the Charge Density Wave Compound Tritelluride  

Science Conference Proceedings (OSTI)

A series of high-pressure electrical resistivity measurements on single crystals of TbTe{sub 3} reveal a complex phase diagram involving the interplay of superconducting, antiferromagnetic and charge density wave order. The onset of superconductivity reaches a maximum of almost 4 K (onset) near {approx} 12.4 GPa.

Hamlin, J.J.; Zocco, D.A.; Sayles, T.A.; Maple, M.B.; /UC, Davis; Chu, J.-H.; Fisher, I.R.; /Stanford U., Geballe Lab.

2010-02-15T23:59:59.000Z

326

Proceedings of 8th Annual EPRI Superconductivity Conference  

Science Conference Proceedings (OSTI)

The Electric Power Research Institutes EPRIs Eighth Annual EPRI Superconductivity ConferencePower Delivery Applications for Superconductivitywas held November 1213, 2008 in Oak Ridge, Tennessee at the Doubletree Hotel Oak Ridge. The U.S. Department of Energy DOE and Oak Ridge National Laboratory co-sponsored the event with EPRIs Superconductivity Program. This report contains the papers presented at the conference.

2008-12-23T23:59:59.000Z

327

STATEMENT OF CONSIDERATIONS REQUEST BY DUPONT SUPERCONDUCTIVITY FOR AN ADVANCE  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

328

Los Alamos scientists see new mechanism for superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

New mechanism for superconductivity New mechanism for superconductivity Los Alamos scientists see new mechanism for superconductivity Researchers have posited an explanation for superconductivity that may open the door to the discovery of new, unconventional forms of superconductivity. November 24, 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.

329

Damping in high-temperature superconducting levitation systems  

Science Conference Proceedings (OSTI)

Methods and apparatuses for improved damping in high-temperature superconducting levitation systems are disclosed. A superconducting element (e.g., a stator) generating a magnetic field and a magnet (e.g. a rotor) supported by the magnetic field are provided such that the superconducting element is supported relative to a ground state with damped motion substantially perpendicular to the support of the magnetic field on the magnet. Applying this, a cryostat housing the superconducting bearing may be coupled to the ground state with high damping but low radial stiffness, such that its resonant frequency is less than that of the superconducting bearing. The damping of the cryostat may be substantially transferred to the levitated magnetic rotor, thus, providing damping without affecting the rotational loss, as can be derived applying coupled harmonic oscillator theory in rotor dynamics. Thus, damping can be provided to a levitated object, without substantially affecting the rotational loss.

Hull, John R. (Sammamish, WA)

2009-12-15T23:59:59.000Z

330

Dual Superconductivity in G2 group  

E-Print Network (OSTI)

We investigate the dual superconductivity mechanism in the exceptional group $G_2$. This is a centerless group (no 't Hooft flux vortices are allowed) and we check for the presence of a magnetic monopole condensate in the confined phase by measuring on the lattice a disorder parameter related to the vacuum expectation value of an operator carrying magnetic charge. The behaviour of the disorder parameter is consistent with the dual superconductor picture. A first step of an analysis on the thermodynamical properties of the theory is conducted by mean of this operator.

G. Cossu; M. D'Elia; A. Di Giacomo; B. Lucini; C. Pica

2006-09-28T23:59:59.000Z

331

Superconductivity as a Bose-Einstein condensation?  

E-Print Network (OSTI)

Bose-Einstein condensation (BEC) in two dimensions (2D) (e.g., to describe the quasi-2D cuprates) is suggested as the possible mechanism widely believed to underlie superconductivity in general. A crucial role is played by nonzero center-of-mass momentum Cooper pairs (CPs) usually neglected in BCS theory. Also vital is the unique {\\it linear} dispersion relation appropriate to weakly-coupled "bosonic" CPs moving in the Fermi sea--rather than in vacuum where the dispersion would be quadratic but only for very strong coupling, and for which BEC is known to be impossible in 2D.

S. K. Adhikari; M. Casas; A. Puente; A. Rigo; M. Fortes; M. A. Solís; M. de Llano; A. A. Valladares; O. Rojo

2000-04-13T23:59:59.000Z

332

Superconducting Hair on Charged Black String Background  

E-Print Network (OSTI)

Behaviour of Dirac fermions in the background of a charged black string penetrated by an Abelian Higgs vortex is elaborated. One finds the evidence that the system under consideration can support fermion fields acting like a superconducting cosmic string in the sence that a nontrivial Dirac fermion field can be carried by the system in question. The case of nonextremal and extremal black string vortex systems were considered. The influence of electric and Higgs charge, the winding number and the fermion mass on the fermion localization near the black string event horizon was studied. It turned out that the extreme charged black string expelled fermion fields more violently comparing to the nonextremal one.

Lukasz Nakonieczny; Marek Rogatko

2012-01-25T23:59:59.000Z

333

Higgs instability in gapless superfluidity/superconductivity  

E-Print Network (OSTI)

In this letter we explore the Higgs instability in the gapless superfluid/superconducting phase. This is in addition to the (chromo)magnetic instability that is related to the fluctuations of the Nambu-Goldstone bosonic fields. While the latter may induce a single-plane-wave LOFF state, the Higgs instability favors spatial inhomogeneity and cannot be removed without a long range force. In the case of the g2SC state the Higgs instability can only be partially removed by the electric Coulomb energy. But this does not exclude the possibility that it can be completely removed in other exotic states such as the gCFL state.

Ioannis Giannakis; Defu Hou; Mei Huang; Hai-cang Ren

2006-06-16T23:59:59.000Z

334

Superconducting radiofrequency linac development at Fermilab  

SciTech Connect

As the Fermilab Tevatron Collider program draws to a close, a strategy has emerged of an experimental program built around the high intensity frontier. The centerpiece of this program is a superconducting H- linac that will support world leading programs in long baseline neutrino experimentation and the study of rare processes. Based on technology shared with the International Linear Collider, Project X will provide multi-MW beams at 60-120 GeV from the Main Injector, simultaneous with very high intensity beams at lower energies. Project X also supports development of a Muon Collider as a future facility at the energy frontier.

Holmes, Stephen D.; /Fermilab

2009-10-01T23:59:59.000Z

335

Current discontinuities on superconducting cosmic strings  

Science Conference Proceedings (OSTI)

The propagation of current perturbations on superconducting cosmic strings is considered. The conditions for the existence of discontinuities similar to shock waves have been found. The formulas relating the string parameters and the discontinuity propagation speed are derived. The current growth law in a shock wave is deduced. The propagation speeds of shock waves with arbitrary amplitudes are calculated. The reason why there are no shock waves in the case of time-like currents (in the 'electric' regime) is explained; this is attributable to the shock wave instability with respect to perturbations of the string world sheet.

Troyan, E., E-mail: et@iaaru.astronautiko.org; Vlasov, Yu. V. [Moscow Institute of Physics and Technology (Russian Federation)

2011-07-15T23:59:59.000Z

336

Superconducting RF Cavities Past, Present and Future  

E-Print Network (OSTI)

In the last two decades many laboratories around the world, notably Argonne (ANL), TJNAF (formerly CEBAF), CERN, DESY and KEK, decided to develop the technology of superconducting (SC) accelerating cavities. The aim was either to increase the accelerator energy or to save electrical consumption or both. This technology has been used extensively in the operating machines showing good performances and strong reliability. At present, the technology using bulk niobium (Nb) or Nb coated on copper (Cu) is mature enough to be applied for many different applications, such as synchrotron light sources and spallation neutron drivers. Results, R&D work and future projects will be presented with emphasis on application to linear accelerators.

Chiaveri, Enrico

2003-01-01T23:59:59.000Z

337

Superconducting Proximity Effect in Single-Crystal Nanowires  

E-Print Network (OSTI)

This dissertation describes experimental studies of the superconducting proximity effect in single-crystal Pb, Sn, and Zn nanowires of lengths up to 60 um, with both ends of the nanowires in contact with macroscopic electrodes that are either superconducting (Sn or Pb) or non-superconducting (Au). The Pb, Sn, and Zn nanowires are fabricated using a template-based electrochemical deposition method. Electric contacts to the nanowires are formed in situ during electrochemical growth. This method produces high transparency contacts between a pair of macroscopic electrodes and a single nanowire, circumventing the formation of oxide or other poorly conducting interface layers. Extensive analyses of the structure and the composition of the nanowire samples are presented to demonstrate that (1) the nanowires are single crystalline and (2) the nanowires are clean without any observable mixing of the materials from the electrodes. The nanowires being investigated are significantly longer than the nanowires with which electrode-induced superconductivity was previously investigated by other groups. We have observed that in relatively short (~6 um) Sn and Zn nanowires, robust superconductivity is induced at the superconducting transition temperatures of the electrodes. When Sn and Pb nanowires are in contact with a pair of Au electrodes, superconductivity is suppressed completely. For nanowires of 60 um in length, although the suppression of superconductivity by Au electrodes is only partial, the induced superconductivity at the higher transition temperatures of the electrodes remains full and robust. Therefore, an anomalous superconducting proximity effect has been observed on a length scale which far exceeds the expected length based on the existing theories of the proximity effect. The measured current-voltage characteristic of the nanowires reveals more details such as hysteresis, multiple Andreev reflection, and phase-slip centers. An interesting relation between the proximity effect and the residual-resistance-ratio of the nanowires has also been observed. Possible mechanisms for this proximity effect are discussed based on these experimental observations.

Liu, Haidong

2009-05-01T23:59:59.000Z

338

CX-003061: Categorical Exclusion Determination | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

061: Categorical Exclusion Determination 061: Categorical Exclusion Determination CX-003061: Categorical Exclusion Determination Recovery Act-Fault Current Limiting (FCL) Superconducting Transformer CX(s) Applied: A9, B3.6, B4.11 Date: 07/16/2010 Location(s): Irvine, California Office(s): Electricity Delivery and Energy Reliability, National Energy Technology Laboratory Southern California Edison will install and operate a prototype fault current limiting superconducting transformer rated 28 megavolt ampere, 66 kilovolt/12 kilovolt service, built by Waukesha Electric, in their MacArthur substation as a demonstration. DOCUMENT(S) AVAILABLE FOR DOWNLOAD CX-003061.pdf More Documents & Publications CX-002486: Categorical Exclusion Determination CX-002485: Categorical Exclusion Determination CX-00120

339

Page not found | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

41 - 6850 of 29,416 results. 41 - 6850 of 29,416 results. Download CX-003061: Categorical Exclusion Determination Recovery Act-Fault Current Limiting (FCL) Superconducting Transformer CX(s) Applied: A9, B3.6, B4.11 Date: 07/16/2010 Location(s): Irvine, California Office(s): Electricity Delivery and Energy Reliability, National Energy Technology Laboratory http://energy.gov/nepa/downloads/cx-003061-categorical-exclusion-determination Download CX-003062: Categorical Exclusion Determination Recovery Act-Fault Current Limiting Superconducting Transformer CX(s) Applied: A11, B3.6 Date: 07/16/2010 Location(s): Schenectady, New York Office(s): Electricity Delivery and Energy Reliability, National Energy Technology Laboratory http://energy.gov/nepa/downloads/cx-003062-categorical-exclusion-determination

340

Optimization of superconducting flux qubit readout using near-quantum-limited amplifiers  

E-Print Network (OSTI)

readout-power-dependent transition down rate. The readout-transition rate is approximately pro- portional to the readout excitation power.

Johnson, Jedediah Edward Jensen

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Design Considerations of Fast-cycling Synchrotrons Based on Superconducting Transmission Line Magnets  

E-Print Network (OSTI)

Design Considerations of Fast-cycling Synchrotrons Based on Superconducting Transmission Line Magnets

Piekarz, H; Huang, Y; Shiltsev, V

2008-01-01T23:59:59.000Z

342

Bottom-up superconducting and Josephson junction devices inside a Group-IV semiconductor  

E-Print Network (OSTI)

We propose superconducting devices made from precision hole-doped regions within a silicon (or germanium) single crystal. We analyze the properties of this superconducting semiconductor and show that practical superconducting wires, Josephson tunnel junctions or weak links, SQUIDs, and qubits are realizable. This work motivates the pursuit of bottom-up superconductivity for improved or fundamentally different technology and physics.

Yun-Pil Shim; Charles Tahan

2013-08-30T23:59:59.000Z

343

SLPX: superconducting long-pulse experiment  

DOE Green Energy (OSTI)

The principal objectives of the SLPX--Superconducting Long-Pulse Experiment--are to demonstrate quasi-steady operation of 3 to 5 MA hydrogen and deuterium plasmas at high temperature and high thermal wall loading, and to develop reliable operation of a prototypical reactor magnetics systems featuring a toroidal assembly of high-field niobium-tin coils. This report summarizes the results of an engineering scoping study for the SLPX. A range of sizes has been investigated, from a TF (toroidal-field) coil aperture of 2.6 m x 3.65 m, to an aperture of 3.1 m x 4.8 m, and with a maximum field at the Nb/sub 3/Sn conductor of 10 to 12 Tesla. The poloidal-field magnetics system utilizes superconducting ohmic-heating and d.c. EF coils located outside the TF coils, together with normal-conducting EF and divertor coils located inside the TF coils. For the largest embodiment, the D-shaped plasma in hydrogen operation has major radius = 3.6 m, half-width = 0.90 m, elongation < 1.5, and B = 7,2 T. Maximum plasma current of 5.0 MA can be maintained for a 30-s flat-top when Z/sub eff/approximately 1. A single-null poloidal magnetic divertor disposes of particles and heat diffusing out of the current channel, thereby helping to insure the feasibility of quasi-steady operation.

Jassby, D.L.; File, J.; Reardon, P.J.

1978-10-01T23:59:59.000Z

344

Superconducting solenoids for the MICE channel  

DOE Green Energy (OSTI)

This report describes the channel of superconductingsolenoids for the proposed international Muon Ionization CoolingExperiment (MICE). MICE consists of two cells of a SFOFO cooling channelthat is similar to that studied in the level 2 study of a neutrinofactory[1]. MICE also consists of two detector solenoids at either end ofthe cooling channel section. The superconducting solenoids for MICEperform three functions. The coupling solenoids, which are largesolenoids around 201.25 MHz RF cavities, couple the muon beam between thefocusing sections as it passes along the cooling channel. The focusingsolenoids are around the liquid hydrogen absorber that reduces themomentum of the muons in all directions. These solenoids generate agradient field along the axis as they reduce the beta of the muon beambefore it enters the absorber. Each detector solenoid system consists offive coils that match the muon beam coming to or from an absorber to a4.0 T uniform solenoidal field section that that contains the particledetectors at the ends of the experiment. There are detector solenoids atthe beginning and at the end of the experiment. This report describes theparameters of the eighteen superconducting coils that make up the MICEmagnetic channel.

Green, M.A.; Barr, G.; Baynham, D.E.; Rockford, J.H.; Fabbricatore, P.; Farinin, S.; Palmer, R.B.; Rey, J.M.

2003-05-01T23:59:59.000Z

345

Density matrix, superconductivity and molecular structure  

Science Conference Proceedings (OSTI)

Starting from Yang`s offdiagonal long-range order concept and the macroscopic occupation condition for the second order density matrix as the basis for condensation phenomena the authors develop the notion that the extremal wave function (EWF), which is related to these conditions, leads to superconductivity in monatomic systems. It is proven that the BCS model and the version where it is projected onto a fixed number of particles possesses EWF properties, differs negligibly from the EWF, and conserves offdiagonal long-range order. The condition for the EWF to be energetically favored is the presence of macroscopic degenerate one-electron energy levels in the system, partial occupation of this degenerate region, and also an effective attraction among the electrons. Considerations are advanced indicating that these conditions are satisfied in the high temperature superconducting metal oxide ceramics, due to the presence of macroscopically degenerate diffusion orbitals distributed among the O{sup -} ions in the CuO{sub 2} layers, and with the effective screening of these layers by the metal-like La, Ba, Y, or O layers. 51 refs., 3 figs., 1 tab.

Mestechkin, M.M.; Klimko, G.T.; Vaiman, G.E. [Academy of Science of the Ukrainian SSR, Donetsk (Russian Federation)

1992-01-01T23:59:59.000Z

346

Strong enhancement of superconductivity in a nanosized Pb bridge  

E-Print Network (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, which are 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 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/Tc ? 0.6. The vortex states lead to a fine structure of the superconducting-to-normal resistive transition. We also analyze vortex states in the bridge, which are characterized by a varying vorticity as a function of the bridge’s height.

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

2008-01-01T23:59:59.000Z

347

Non-Fermi Liquid Regimes and Superconductivity in the Low Temperature Phase Diagrams of Strongly Correlated d- and f-Electron Materials  

E-Print Network (OSTI)

Zapf, J. Wosnitza, Superconductivity in Conventional andLiquid Regimes and Superconductivity in the Low Temperatureas un- conventional superconductivity and novel magnetic

Brian Maple, M.; Baumbach, Ryan E.; Butch, Nicholas P.; Hamlin, James J.; Janoschek, Marc

2010-01-01T23:59:59.000Z

348

Detector limitations, STAR  

Science Conference Proceedings (OSTI)

Every detector has limitations in terms of solid angle, particular technologies chosen, cracks due to mechanical structure, etc. If all of the presently planned parts of STAR [Solenoidal Tracker At RHIC] were in place, these factors would not seriously limit our ability to exploit the spin physics possible in RHIC. What is of greater concern at the moment is the construction schedule for components such as the Electromagnetic Calorimeters, and the limited funding for various levels of triggers.

Underwood, D. G.

1998-07-13T23:59:59.000Z

349

Power Switches Utilizing Superconducting Material for Accelerator Magnets  

E-Print Network (OSTI)

Power switches that utilize superconducting material find application in superconducting systems. They can be used for the protection of magnets as a replacement for warm DC breakers, as well as for the replacement of cold diodes. This paper presents a comparison of switches made of various superconducting materials having transport currents of up to 600 A and switching times of the order of milliseconds. The switches operate in the temperature range 4.2-77 K and utilize stainless steel clad YBCO tape and MgB2 tape with a nickel, copper, and iron matrix. Results from simulations and tests are reported.

March, S A; Yang, Y; 10.1109/TASC.2009.2017890

2009-01-01T23:59:59.000Z

350

Topologically-protected quantum memory interfacing atomic and superconducting qubits  

E-Print Network (OSTI)

We propose a scheme to manipulate a kind of topological spin qubits realized with cold atoms in a one-dimensional optical lattice. In particularly, by introducing a quantum optomechanical setup, we are able to fist transfer a superconducting qubit state to an atomic state and then to store it into the topological spin qubit. In this way, an efficient topological quantum memory may be constructed for the superconducting qubit. Therefore, we can consolidate the advantages of both the noise resistance of topological qubits and the scalability of superconducting qubits in this hybrid architecture.

Zheng-Yuan Xue; Zhang-qi Yin; Yan Chen; Z. D. Wang; Shi-Liang Zhu

2013-01-17T23:59:59.000Z

351

Thermal evolution of rotating strange stars in color superconductivity phase  

E-Print Network (OSTI)

Under the combination effect of the recommencement heating due to spin-down of strange stars and the heat perseveration due to weak conduct heat of the crust, the Cooper pair breaking and formation(PBF) in color superconduction quark matter arises. We investigated the cooling of the strange stars with a crust in color superconductivity phase including both decomfinement heating and PBF process. We find that deconfinement heating can delay the thermal evolution of strange stars and the PBF process suppresses the early temperature rise of the stars. The cooling strange stars behave within the brightness constraint of young compact objects when the color superconductivity gap is small enough.

X. P. Zheng; X. Zhou; Y. W. Yu

2006-07-04T23:59:59.000Z

352

System and method for cooling a superconducting rotary machine  

Science Conference Proceedings (OSTI)

A system for cooling a superconducting rotary machine includes a plurality of sealed siphon tubes disposed in balanced locations around a rotor adjacent to a superconducting coil. Each of the sealed siphon tubes includes a tubular body and a heat transfer medium disposed in the tubular body that undergoes a phase change during operation of the machine to extract heat from the superconducting coil. A siphon heat exchanger is thermally coupled to the siphon tubes for extracting heat from the siphon tubes during operation of the machine.

Ackermann, Robert Adolf (Schenectady, NY); Laskaris, Evangelos Trifon (Schenectady, NY); Huang, Xianrui (Clifton Park, NY); Bray, James William (Niskayuna, NY)

2011-08-09T23:59:59.000Z

353

Limited Warranty Research In Motion Limited (“RIM”), the ...  

Science Conference Proceedings (OSTI)

... Handheld Limited Warranty (Jordan) 072406 (English) (UK Version 082504) 1 Page 2. Handheld Limited Warranty (Jordan ...

2012-11-15T23:59:59.000Z

354

Limited discrepancy search revisited  

Science Conference Proceedings (OSTI)

Harvey and Ginsberg's limited discrepancy search (LDS) is based on the assumption that costly heuristic mistakes are made early in the search process. Consequently, LDS repeatedly probes the state space, going against the heuristic (i.e., taking discrepancies) ... Keywords: Heuristic mistakes, limited discrepancy search, performance improvement

Patrick Prosser; Chris Unsworth

2011-05-01T23:59:59.000Z

355

LHC Magnet Program | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

356

HERA Upgrade Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

357

J-PARC Correctors | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

358

Meetings & Workshops | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

359

LOTO Authorized Personnel | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

360

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

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Automated Hydroforming of Seamless Superconducting RF Cavity  

SciTech Connect

We are studying the possibility of automated hydroforming process for seamless superconducting RF cavities. Preliminary hydroforming tests of three-cell cavities from seamless tubes made of C1020 copper have been performed. The key point of an automated forming is to monitor and strictly control some parameters such as operation time, internal pressure and material displacements. Especially, it is necessary for our studies to be able to control axial and radial deformation independently. We plan to perform the forming in two stages to increase the reliability of successful forming. In the first stage hydroforming by using intermediate constraint dies, three-cell cavities were successfully formed in less than 1 minute. In parallel, we did elongation tests on cavity-quality niobium and confirmed that it is possible to achieve an elongation of >64% in 2 stages that is required for our forming of 1.3 GHz cavities.

Nagata, Tomohiko [ULVAC, Inc.; Shinozawa, Seiichi [ULVAC, Inc.; Abe, Noriyuki [ULVAC, Inc.; Nagakubo, Junki [ULVAC, Inc.; Murakami, Hirohiko [ULVAC, Inc.; Tajima, Tsuyoshi [Los Alamos National Laboratory; Inoue, Hitoshi [High Energy Accelerator Research Organization, KEK; Yamanaka, Masashi [High Energy Accelerator Research Organization, KEK; Ueno, Kenji [High Energy Accelerator Research Organization, KEK

2012-07-31T23:59:59.000Z

362

Type I Superconductivity in Neutron Stars  

E-Print Network (OSTI)

The magnetic structure of neutron vortices in the superfluid cores of neutron stars is determined assuming that the proton condensate forms a type I superconductor. It is shown that the entrainment currents induced by the neutron vortex circulation cause the proton superconductor to break into successive domains of normal and superconducting regions. The Gibbs free-energy is found in the case in which the normal domains form cylindrical tubes coaxial with the neutron vortex. The minimum of the energy functional corresponds to a tube radius $a\\sim 0.1-0.5 ~b$, where $b$ is the outer radius of the neutron vortex. The magnetic field within the tube is of the order of $ 5 \\times 10^{14}$ G.

D. M. Sedrakian; A. Sedrakian; G. F. Zharkov

1997-10-24T23:59:59.000Z

363

Diffusion effects on a superconductive model  

E-Print Network (OSTI)

A superconductive model characterized by a third order parabolic operator L" is analysed. When the viscous terms, represented by higher - order deriva- tives, tend to zero, a hyperbolic operator L0 appears. Furthermore, if P" is the Dirichlet initial boundary - value problem for L", when L" turns into L0; P" turns into a problem P0 with the same initial - boundary conditions as P". The solution of the nonlinear problem related to the remainder term r is achieved, as long as the higher-order derivatives of the solution of P0 are bounded. More- over, some classes of explicit solutions related to P0 are determined, proving the existence of at least one motion whose derivatives are bounded. The estimate shows that the diffusion effects are bounded even when time tends to infinity.

M. de Angelis; G. Fiore

2012-11-06T23:59:59.000Z

364

Method of preparing composite superconducting wire  

DOE Patents (OSTI)

An improved method of preparing composite multifilament superconducting wire of Nb.sub.3 Sn in a copper matrix which eliminates the necessity of coating the drawn wire with tin. A generalized cylindrical billet of an alloy of copper containing at least 15 weight percent niobium, present in the copper as discrete, randomly distributed and oriented dendritic-shaped particles, is provided with at least one longitudinal opening which is filled with tin to form a composite drawing rod. The drawing rod is then drawn to form a ductile composite multifilament wire containing a filament of tin. The ductile wire containing the tin can then be wound into magnet coils or other devices before heating to diffuse the tin through the wire to react with the niobium forming Nb.sub.3 Sn. Also described is an improved method for making large billets of the copper-niobium alloy by consumable-arc casting.

Verhoeven, John D. (Ames, IA); Gibson, Edwin D. (Ames, IA); Finnemore, Douglas K. (Ames, IA); Ostenson, Jerome E. (Ames, IA); Schmidt, Frederick A. (Ames, IA); Owen, Charles V. (Ames, IA)

1985-08-06T23:59:59.000Z

365

Improved method of preparing composite superconducting wire  

DOE Patents (OSTI)

An improved method of preparing composite multifilament superconducting wire of Nb/sub 3/Sn in a copper matrix eliminates the necessity of coating the drawn wire with tin. A generalized cylindrical billet of an alloy of copper containing at least 15 weight percent niobium, present in the copper as discrete, randomly distributed and oriented dendritic-shaped particles, is provided with at least one longitudinal opening which is filled with tin to form a composite drawing rod. The drawing rod is then drawn to form a ductile composite multifilament wire containing a filament of tin. The ductile wire containing the tin can then be wound into magnet coils or other devices before heating to diffuse the tin through the wire to react with the niobium forming Nb/sub 3/Sn. Also described is an improved method for making large billets of the copper-niobium alloy by consumable-arc casting.

Verhoeven, J.D.; Gibson, E.D.; Finnemore, D.K.; Ostenson, J.E.; Schmidt, F.A.; Owen, C.V.

1979-10-17T23:59:59.000Z

366

Improved method of preparing composite superconducting wire  

DOE Patents (OSTI)

An improved method of preparing composite multifilament superconducting wire of Nb/sub 3/Sn in a copper matrix which eliminates the necessity of coating the drawn wire with tin is described. A generalized cylindrical billet of an alloy of copper containing at least 15 weight percent niobium, present in the copper as discrete, randomly distributed and oriented dendritic-shaped particles, is provided with at least one longitudinal opening which is filled with tin to form a composite drawing rod. The drawing rod is then drawn to form a ductile composite multifilament wire containing a filament of tin. The ductile wire containing the tin can then be wound into magnet coils or other devices before heating to diffuse the tin through the wire to react with the niobium forming Nb/sub 3/Sn. Also described is an improved method for making large billets of the copper-niobium alloy by consumable-arc casting.

Verhoeven, J.D.; Gibson, E.D.; Finnemore, D.K.; Ostenson, J.E.; Schmidt, F.A.; Owen, C.V.

1981-04-24T23:59:59.000Z

367

Electromagnetically induced interference at superconducting qubits  

E-Print Network (OSTI)

We study electromagnetically induced interference at superconducting qubits. The interaction between qubits and electromagnetic fields can provide additional coupling channels to qubit states, leading to quantum interference in a microwave driven qubit. In particular, the interwell relaxation or Rabi oscillation, resulting respectively from the multi- or single-mode interaction, can induce effective crossovers. The environment is modeled by a multi-mode thermal bath, generating the interwell relaxation. Relaxation induced interference, independent of the tunnel coupling, provides deeper understanding to the interaction between the qubits and their environment. It also supplies a useful tool to characterize the relaxation strength as well as the characteristic frequency of the bath. In addition, we demonstrate the relaxation can generate population inversion in a strongly driving two-level system. On the other hand, different from Rabi oscillation, Rabi oscillation induced interference involves more complicate...

Du, Lingjie

2010-01-01T23:59:59.000Z

368

Tunable electromagnetic environment for superconducting quantum bits  

E-Print Network (OSTI)

We introduce a setup which realises a tunable engineered environment for experiments in circuit quantum electrodynamics. We illustrate this concept with the specific example of a quantum bit, qubit, in a high-quality-factor cavity which is capacitively coupled to another cavity including a resistor. The temperature of the resistor, which acts as the dissipative environment, can be controlled in a well defined manner in order to provide a hot or cold environment for the qubit, as desired. Furthermore, introducing superconducting quantum interference devices (SQUIDs) into the cavity containing the resistor, provides control of the coupling strength between this artificial environment and the qubit. We demonstrate that our scheme allows us to couple strongly to the environment enabling rapid initialization of the system, and by subsequent tuning of the magnetic flux of the SQUIDs we may greatly reduce the resistor-qubit coupling, allowing the qubit to evolve unhindered.

P. J. Jones; J. A. M. Huhtamäki; J. Salmilehto; K. Y. Tan; M. Möttönen

2013-02-15T23:59:59.000Z

369

Competition between superconductivity and spin density wave  

E-Print Network (OSTI)

The Hubbard model has been investigated widely by many authors, while this work may be new in two aspects. One, we focus on the possible effects of the positions of the gaps associated with the pairing and the spin density wave. Two, we suggest that the models with different parameters are appropriate for different materials (or a material in different doped regions). This will lead to some new insights into the high temperature superconductors. It is shown that the SDW can appear at some temperature region when the on-site Coulomb interaction is larger, while the SC requires a decreased U at a lower temperature. This can qualitatively explain the relationship between superconducting and pseudogap states of Cu-based superconductors in underdoped and optimally doped regions. The superinsulator is also discussed.

Tian De Cao

2011-01-02T23:59:59.000Z

370

The Lichnerowicz-Weitzenboeck formula and superconductivity  

SciTech Connect

We derive the Lichnerowicz-Weitzenboeck formula for the two-component order parameter superconductor, which provides a twofold view of the kinetic energy of the superconductor. For the one component order parameter superconductor we review the connection between the Lichnerowicz-Weitzenboeck formula and the Ginzburg-Landau theory. For the two-component case we claim that this formula opens a venue to describe inhomogeneous superconducting states intertwined by spin correlations and charged dislocation. In this case the Lichnerowicz-Weitzenboeck formula displays local rotational and electromagnetic gauge symmetry (SU(2) Circled-Times U(1)) and relies on local commuting momentum and spin operators. The order parameter lives in a space with curvature and torsion described by Elie Cartan geometrical formalism. The Lichnerowickz-Weitzenboeck formula leads to first order differential equations that are a three-dimensional version of the Seiberg-Witten equations.

Vargas-Paredes, Alfredo A.; Doria, Mauro M. [Departamento de Fisica dos Solidos, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro (Brazil)] [Departamento de Fisica dos Solidos, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro (Brazil); Neto, Jose Abdala Helayeel [Centro Brasileiro de Pesquisas Fisicas, 22290-160 Rio de Janeiro RJ (Brazil)] [Centro Brasileiro de Pesquisas Fisicas, 22290-160 Rio de Janeiro RJ (Brazil)

2013-01-15T23:59:59.000Z

371

Quench anaylsis of MICE spectrometer superconducting solenoid  

SciTech Connect

MICE superconducting spectrometer solenoids fabrication and tests are in progress now. First tests of the Spectrometer Solenoid discovered some issues which could be related to the chosen passive quench protection system. Both solenoids do not have heaters and quench propagation relied on the 'quench back' effect, cold diodes, and shunt resistors. The solenoids have very large inductances and stored energy which is 100% dissipated in the cold mass during a quench. This makes their protection a challenging task. The paper presents the quench analysis of these solenoids based on 3D FEA solution of coupled transient electromagnetic and thermal problems. The simulations used the Vector Fields QUENCH code. It is shown that in some quench scenarios, the quench propagation is relatively slow and some areas can be overheated. They describe ways of improving the solenoids quench protection in order to reduce the risk of possible failure.

Kashikhin, Vladimir; Bross, Alan; /Fermilab; Prestemon, Soren; / /LBL, Berkeley

2011-09-01T23:59:59.000Z

372

Fast thermometry for superconducting rf cavity testing  

SciTech Connect

Fast readout of strategically placed low heat capacity thermometry can provide valuable information of Superconducting RF (SRF) cavity performance. Such a system has proven very effective for the development and testing of new cavity designs. Recently, several resistance temperature detectors (RTDs) were installed in key regions of interest on a new 9 cell 3.9 GHz SRF cavity with integrated HOM design at FNAL. A data acquisition system was developed to read out these sensors with enough time and temperature resolution to measure temperature changes on the cavity due to heat generated from multipacting or quenching within power pulses. The design and performance of the fast thermometry system will be discussed along with results from tests of the 9 cell 3.9GHz SRF cavity.

Orris, Darryl; Bellantoni, Leo; Carcagno, Ruben H.; Edwards, Helen; Harms, Elvin Robert; Khabiboulline, Timergali N.; Kotelnikov, Sergey; Makulski, Andrzej; Nehring, Roger; Pischalnikov, Yuriy; /Fermilab

2007-06-01T23:59:59.000Z

373

Some aspects of superconducting accelerator design  

SciTech Connect

The performance of an accelerator can be characterized by the efficiency with which electrical energy, the minimumm energy needed to generate a given beam voltage. The current accelerator improvement program at SLAC aims at raising the beam voltage to 50 GV which will use 240 klystrons each capable of producing a pulse 5 ..mu..s in length at a peak power of 36 MW. The Linear Collider requires 50 MW klystrons to achieve 60 GV which will raise the concomittant power consumption to 32.3 MW. We show that with superconducting elements we can increase the rf and ac conversion efficiencies and achieve the necessary 50 GV using only 1/3 of the present power requirements, provided that we exclude CW operation. We will further demonstrate that this increase in efficiency is crucial and highly significant in the design of a proposed 1000 GV linear accelerator.

Farkas, Z.D.; St. Lorant, S.J.

1982-11-01T23:59:59.000Z

374

IMPROVING THE DESIGN AND ANALYSIS OF SUPERCONDUCTING MAGNETS FOR PARTICLE ACCELERATORS  

SciTech Connect

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

375

High Power Superconducting Continuous Wave Linacs for Protons and  

Office of Science (SC) Website

Power Superconducting Continuous Power Superconducting Continuous Wave Linacs for Protons and Heavy-Ions Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives High Power Superconducting Continuous Wave Linacs for Protons and Heavy-Ions Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: High Power Superconducting Continuous Wave Linacs for Protons and Heavy-Ions

376

J. Robert Schrieffer and the BCS Theory of Superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

J. Robert Schrieffer and the BCS Theory of Superconductivity J. Robert Schrieffer and the BCS Theory of Superconductivity Resources with Additional Information J. Robert Schrieffer Courtesy of NHMFL Robert Schrieffer received his BS from M.I.T. in 1953 and his Ph.D. from the University of Illinois in 1957. Upon entering the University of Illinois, "he immediately began research with Professor John Bardeen. After working out a problem dealing with electrical conduction on semiconductor surfaces, Schrieffer spent a year in the laboratory, applying the theory to several surface problems. In the third year of graduate studies, he joined Bardeen and [Leon] Cooper in developing the theory of superconductivity, which constituted his doctoral dissertation."1 Bardeen, Cooper and Schrieffer were awarded the 1972 Nobel Prize in Physics "for their jointly developed theory of superconductivity, usually called the BCS-theory".

377

Proceedings of the 1968 Summer Study on Superconducting Devices and  

NLE Websites -- All DOE Office Websites (Extended Search)

1968 Summer Study on Superconducting Devices and 1968 Summer Study on Superconducting Devices and Accelerators Brookhaven National Laboratory June 10 - July 19, 1968 1968 summer study on superconducting devices and accelerators at Brookhaven National Laboratory is considered as one of the most important and defining meeting that led to the application of superconductivity in modern particle accelerators and storage rings. One must admire that bold vision, and years of persistent and hard work of number of scientists, engineers and technicians which turned that vision in to reality. Moreover, the research work presented then, serves as a good reference material even today. Given its historical and scientific importance, the entire proceedings of this six week study is made available now on the web for easy and wide access.

378

Fermilab | Recovery Act | High-field superconducting magnets  

NLE Websites -- All DOE Office Websites (Extended Search)

may allow scientists to create high-field superconducting magnets that could exceed 50 Tesla, or more than twice the strength of existing magnets. In the project's first phase,...

379

Critical magnetic field of surface superconductivity in lead  

SciTech Connect

The critical superconductivity field H{sub c3} is measured on lead single crystals. It is shown that the temperature dependence of H{sub c3}/H{sub c} in the vicinity of superconducting transition temperature T{sub c} is essentially nonlinear. Relative changes in the value of H{sub c3}/H{sub c} reach approximately 30%, which cannot be described by the Ginzburg-Landau theory. The experimental temperature dependences lead to the conclusion that the surface superconducting transition temperature noticeably exceeds the superconducting transition temperature in the bulk of the semiconductor. The differences in the critical temperatures and in the Ginzburg-Landau parameters for lead are estimated.

Khlyustikov, I. N., E-mail: khly@kapitza.ras.ru [Russian Academy of Sciences, Kapitza Institute of Physical Problems (Russian Federation)

2011-12-15T23:59:59.000Z

380

Chiral superconductivity from repulsive interactions in doped graphene  

E-Print Network (OSTI)

Chiral superconductivity, which breaks time-reversal symmetry, can exhibit a wealth of fascinating properties that are highly sought after for nanoscience applications. We identify doped graphene monolayer as a system where ...

Chubukov, A. V.

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

Dual Superconductivity and Chiral Symmetry in Full QCD  

E-Print Network (OSTI)

A disorder parameter detecting dual superconductivity of the vacuum is measured across the chiral phase transition in full QCD with two flavours of dynamical staggered fermions. The observed behaviour is similar to the quenched case.

J. M. Carmona; M. D'Elia; L. Del Debbio; A. Di Giacomo; B. Lucini; G. Paffuti

2001-10-12T23:59:59.000Z

382

Color symmetrical superconductivity in a schematic nuclear quark model  

E-Print Network (OSTI)

In this note, a novel BCS-type formalism is constructed in the framework of a schematic QCD inspired quark model, having in mind the description of color symmetrical superconducting states. The physical properties of the BCS vacuum (average numbers of quarks of different colors) remain unchanged under an arbitrary color rotation. In the usual approach to color superconductivity, the pairing correlations affect only the quasi-particle states of two colors, the single particle states of the third color remaining unaffected by the pairing correlations. In the theory of color symmetrical superconductivity here proposed, the pairing correlations affect symmetrically the quasi-particle states of the three colors and vanishing net color-charge is automatically insured. It is found that the groundstate energy of the color symmetrical sector of the Bonn model is well approximated by the average energy of the color symmetrical superconducting state proposed here.

Henrik Bohr; João da Providência

2009-09-14T23:59:59.000Z

383

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

384

Novel Approach to Linear Accelerator Superconducting Magnet System  

SciTech Connect

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

385

Efficiently Coupling Light to Superconducting Nanowire Single-Photon Detectors  

E-Print Network (OSTI)

We designed superconducting nanowire single-photon detectors (SNSPDs) integrated with silver optical antennae for free-space coupling and a dielectric waveguide for fiber coupling. According to our finite-element simulation, ...

Hu, Xiaolong

386

Afterpulsing and instability in superconducting nanowire avalanche photodetectors  

E-Print Network (OSTI)

We investigated the reset time of superconducting nanowire avalanche photodetectors (SNAPs) based on 30?nm wide nanowires. We studied the dependence of the reset time of SNAPs on the device inductance and discovered that ...

Marsili, Francesco

387

Multi-level quantum description of decoherence in superconducting qubits  

E-Print Network (OSTI)

We present a multi-level quantum theory of decoherence for a general circuit realization of a superconducting qubit. Using electrical network graph theory, we derive a Hamiltonian for the circuit. The dissipative circuit elements (external impedances, shunt resistors) are described using the Caldeira-Leggett model. The master equation for the superconducting phases in the Born-Markov approximation is derived and brought into the Bloch-Redfield form in order to describe multi-level dissipative quantum dynamics of the circuit. The model takes into account leakage effects, i.e. transitions from the allowed qubit states to higher excited states of the system. As a special case, we truncate the Hilbert space and derive a two-level (Bloch) theory with characteristic relaxation (T_1) and decoherence (T_2) times. We apply our theory to the class of superconducting flux qubits; however, the formalism can be applied for both superconducting flux and charge qubits.

Guido Burkard; Roger H. Koch; David P. DiVincenzo

2003-08-01T23:59:59.000Z

388

Superconductivity with deformed Fermi surfaces and compact stars  

E-Print Network (OSTI)

I discuss the deformed Fermi surface superconductivity (DFS) and some of its alternatives in the context of nucleonic superfluids and two flavor color superconductors that may exist in the densest regions of compact stellar objects.

Armen Sedrakian

2003-12-15T23:59:59.000Z

389

Evolution of spin excitations into the superconducting state...  

NLE Websites -- All DOE Office Websites (Extended Search)

x )Fe 2 As 2 . Phys. Rev. Lett. 101, 107006 (2008). 4. Christianson, A. D. et al. Unconventional superconductivity in Ba 0.6 K 0.4 Fe 2 As 2 from inelastic neutron scattering....

390

Radiofrequency amplifier based on a dc superconducting quantum interference device  

DOE Patents (OSTI)

A low noise radiofrequency amplifer, using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID and an input coil are maintained at superconductivity temperatures in a superconducting shield, with the input coil inductively coupled to the superconducting ring of the dc SQUID. A radiofrequency signal from outside the shield is applied to the input coil, and an amplified radiofrequency signal is developed across the dc SQUID ring and transmitted to exteriorly of the shield. A power gain of 19.5 +- 0.5 dB has been achieved with a noise temperature of 1.0 +- 0.4 K at a frequency of 100 MHz.

Hilbert, C.; Martinis, J.M.; Clarke, J.

1984-04-27T23:59:59.000Z

391

Radiofrequency amplifier based on a dc superconducting quantum interference device  

DOE Patents (OSTI)

A low noise radiofrequency amplifier (10), using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID (11) and an input coil (12) are maintained at superconductivity temperatures in a superconducting shield (13), with the input coil (12) inductively coupled to the superconducting ring (17) of the dc SQUID (11). A radiofrequency signal from outside the shield (13) is applied to the input coil (12), and an amplified radiofrequency signal is developed across the dc SQUID ring (17) and transmitted to exteriorly of the shield (13). A power gain of 19.5.+-.0.5 dB has been achieved with a noise temperature of 1.0.+-.0.4 K. at a frequency of 100 MHz.

Hilbert, Claude (Berkeley, CA); Martinis, John M. (Berkeley, CA); Clarke, John (Berkeley, CA)

1986-01-01T23:59:59.000Z

392

Strain-induced time-reversal odd superconductivity in graphene  

E-Print Network (OSTI)

Time-reversal symmetry breaking superconductors are exotic phases of matter with fascinating properties, which are, however, encountered rather sparsely. Here we identify the possibility of realizing such a superconducting state that exhibits an $f+is$ pairing symmetry in strained graphene. Although the underlying attractive interactions need to be sufficiently strong and comparable in pristine graphene to support such pairing state, we argue that strain can be conducive for its formation even for weak interactions. We show that quantum-critical behavior near the transition is controlled by a multicritical point, characterized by various critical exponents computed here in the framework of an $\\epsilon$-expansion near four spacetime dimensions. Furthermore, a vortex in this mixed superconducting state hosts a pair of Majorana fermions supporting a quartet of insulating and superconducting orders, among which topologically nontrivial quantum spin Hall insulator. These findings suggest that strained graphene could provide a platform for the realization of exotic superconducting states of Dirac fermions.

Bitan Roy; Vladimir Juricic

2013-09-02T23:59:59.000Z

393

Spontaneous brillouin scattering quench diagnostics for large superconducting magnets  

E-Print Network (OSTI)

Large superconducting magnets used in fusion reactors, as well as other applications, need a diagnostic that can non-invasively measure the temperature and strain throughout the magnet in real-time. A new fiber optic sensor ...

Mahar, Scott B

2008-01-01T23:59:59.000Z

394

Wire rope superconducting cable for diurnal load leveling SMES  

DOE Green Energy (OSTI)

The design of a wire rope cable for a superconducting magnetic energy storage (SMES) unit is discussed. The superconducting wires in the rope permit the passage of large currents in the relatively small conductors of the windings and hence cause large electromagnetic forces to act on the rope. The diameter of the rope, from a strength point of view, can be considerably reduced by supporting the rope at various points along its length.

Costello, G.A.

1980-01-01T23:59:59.000Z

395

Control of Superconductivity in Cuprate/Manganite Heterostructures  

E-Print Network (OSTI)

Control of Superconductivity in Cuprate/Manganite Heterostructures Brian SiewHan Pang Hughes Hall University of Cambridge A dissertation submitted for the degree of Doctor of Philosophy at University of Cambridge June 2004 iAbstract Research has... shown that the spin alignment in an adjacent ferromagnet is capable of suppress- ing superconductivity. In this project, devices incorporating cuprate/manganite heterostuctres were successfully fabricated to study the effects of spin transport...

Pang, Brian SiewHan

396

Toroidal constant-tension superconducting magnetic energy storage units  

DOE Patents (OSTI)

A superconducting magnetic energy storage unit is provided in which the magnet is wound in a toroidal fashion such that the magnetic field produced is contained only within the bore of the magnet, and thus producing a very low external field. The superconducting magnet includes a coolant channel disposed through the wire. The bore of the magnet comprises a storage volume in which cryogenic coolant is stored, and this volume supplies the coolant to be delivered to the coolant in the magnet.

Herring, J.S.

1990-10-26T23:59:59.000Z

397

Toroidal constant-tension superconducting magnetic energy storage units  

DOE Patents (OSTI)

A superconducting magnetic energy storage unit is provided in which the magnet is wound in a toroidal fashion such that the magnetic field produced is contained only within the bore of the magnet, and thus producing a very low external field. The superconducting magnet includes a coolant channel disposed through the wire. The bore of the magnet comprises a storage volume in which cryogenic coolant is stored, and this volume supplies the coolant to be delivered to the coolant channel in the magnet.

Herring, J. Stephen (Idaho Falls, ID)

1992-01-01T23:59:59.000Z

398

Cooling of superconducting devices by liquid storage and refrigeration unit  

SciTech Connect

A system is disclosed for cooling superconducting devices. The system includes a cryogen cooling system configured to be coupled to the superconducting device and to supply cryogen to the device. The system also includes a cryogen storage system configured to supply cryogen to the device. The system further includes flow control valving configured to selectively isolate the cryogen cooling system from the device, thereby directing a flow of cryogen to the device from the cryogen storage system.

Laskaris, Evangelos Trifon; Urbahn, John Arthur; Steinbach, Albert Eugene

2013-08-20T23:59:59.000Z

399

Microstrip filters for measurement and control of superconducting qubits  

E-Print Network (OSTI)

Careful filtering is necessary for observations of quantum phenomena in superconducting circuits at low temperatures. Measurements of coherence between quantum states requires extensive filtering to protect against noise coupled from room temperature electronics. We demonstrate distributed transmission line filters which cut off exponentially at GHz frequencies and can be anchored at the base temperature of a dilution refrigerator. The compact design makes them suitable to filter many different bias lines in the same setup, necessary for the control and measurement of superconducting qubits.

Longobardi, Luigi; Patel, Vijay; Chen, Wei; Lukens, James E

2013-01-01T23:59:59.000Z

400

CONTROL LIMITER DEVICE  

DOE Patents (OSTI)

A control-limiting device for monltoring a control system is described. The system comprises a conditionsensing device, a condition-varying device exerting a control over the condition, and a control means to actuate the condition-varying device. A control-limiting device integrates the total movement or other change of the condition-varying device over any interval of time during a continuum of overlapping periods of time, and if the tothl movement or change of the condition-varying device exceeds a preset value, the control- limiting device will switch the control of the operated apparatus from automatic to manual control.

DeShong, J.A.

1960-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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

SCMS-1, Superconducting Magnet System for an MHD generator  

DOE Green Energy (OSTI)

The research and development effort connected with the building of the superconducting magnet systems for MHD generators at the Institute for High Temperatures of the U.S.S.R. Academy of Sciences included the designing, fabrication and testing of the superconducting magnet system for an MHD generator (SCMS-1), producing a magnetic field up to 4 Tesla in a warm bore tube 300 mm in diameter and 1000 mm long (the nonuniformity of the magnetic field in the warm bore did not exceed +-5%. The superconducting magnet system is described. The design selected consisted of a dipole, saddle-form coil, wound around a tube. The cooling of the coils is of the external type with helium access to each layer of the winding. For winding of the superconducting magnet system a 49-strand cable was used consisting of 42 composition conductors, having a diameter of 0.3 mm each, containing six superconducting strands with a niobium-titanium alloy base (the superconducting strands were 70 microns in diameter), and seven copper conductors of the same diameter as the composite conductors. The cable is made monolithic with high purity indium and insulated with lavsan fiber. The cable diameter with insulation is 3.5 mm. (WHK)

Zenkevich, V.B.; Kirenin, I.A.; Tovma, V.A.

1977-01-01T23:59:59.000Z

402

A Superconducting transformer system for high current cable testing  

Science Conference Proceedings (OSTI)

This article describes the development of a direct-current (dc) superconducting transformer system for the high current test of superconducting cables. The transformer consists of a core-free 10 464 turn primary solenoid which is enclosed by a 6.5 turn secondary. The transformer is designed to deliver a 50 kA dc secondary current at a dc primary current of about 50 A. The secondary current is measured inductively using two toroidal-wound Rogowski coils. The Rogowski coil signal is digitally integrated, resulting in a voltage signal that is proportional to the secondary current. This voltage signal is used to control the secondary current using a feedback loop which automatically compensates for resistive losses in the splices to the superconducting cable samples that are connected to the secondary. The system has been commissioned up to 28 kA secondary current. The reproducibility in the secondary current measurement is better than 0.05% for the relevant current range up to 25 kA. The drift in the secondary current, which results from drift in the digital integrator, is estimated to be below 0.5 A/min. The system's performance is further demonstrated through a voltage-current measurement on a superconducting cable sample at 11 T background magnetic field. The superconducting transformer system enables fast, high resolution, economic, and safe tests of the critical current of superconducting cable samples.

Godeke, A.; Dietderich, D. R.; Joseph, J. M.; Lizarazo, J.; Prestemon, S. O.; Miller, G.; Weijers, H. W.

2010-02-15T23:59:59.000Z

403

Road to room-temperature superconductivity: A universal model  

E-Print Network (OSTI)

In a semiclassical view superconductivity is attributed exclusively to the advance of atoms' outer s electrons through the nuclei of neighbor atoms in a solid. The necessary progression of holes in the opposite direction has the electric and magnetic effect as if two electrons were advancing instead of each actual one. Superconductivity ceases when the associated lateral oscillation of the outer s electrons extends between neighbor atoms. If such overswing occurs already at T = 0, then the material is a normal conductor. Otherwise, lateral overswing can be caused by lattice vibrations at a critical temperature Tc or by a critical magnetic field Bc. Lateral electron oscillations are reduced - and Tc is increased - when the atoms of the outer s electrons are squeezed, be it in the bulk crystal, in a thin film, or under external pressure on the sample. The model is applied to alkali metals and alkali-doped fullerenes. Aluminum serves as an example of a simple metal with superconductivity. Application of the model to transition metals, intertransitional alloys and compounds of transition metals with other elements sheds light on the pattern of their critical temperature. More examples of the squeeze effect are provided by the superconductivity of PdH, MgB2, borocarbides, ferropnictides, and organic charge-transfer salts. The model also provides the superconduction mechanism in the oxide superconductors, exemplified by YBa2Cu3O7. Finally the model suggests which steps to take in order to reach superconductivity at room temperature and above.

Manfred Bucher

2013-02-15T23:59:59.000Z

404

Imaging magnetic sources in the presence of superconducting surfaces : model&experiment  

DOE Green Energy (OSTI)

The forward physics model describing the effect of a superconducting surface on the magnetic field distribution resulting from specific magnetic sources has numerous applications ranging from basic physics experiments to large superconducting magnets used in energy storage and magnetic resonance imaging. In this paper, we describe the novel application of a superconducting imaging surface (SIS) to enhance the performance of systems designed to directly observe and localize human brain function. Magnetoencephalography (MEG) measures the weak magnetic fields emanating from the brain as a direct consequence of the neuronal currents resulting from brain function[1]. The extraordinarily weak magnetic fields are measured by an array of SQUID (Superconducting QUantum Interference Device) sensors. The position and vector characteristics of these neuronal sources can be estimated from the inverse solution of the field distribution at the surface of the head. In addition, MEG temporal resolution is unsurpassed by any other method currently used for brain imaging. Although MEG source reconstruction is limited by solutions of the electromagnetic inverse problem, constraints used for source localization produce reliable results. A novel MEG system incorporating a SIS has been designed and built at Los Alamos with the goal of dramatically improving source localization accuracy while mitigating limitations of current systems (e.g. low signal-to-noise, cost, bulk). We incorporate shielding and source field measurement into an integrated design and combine the latest SQUID and data acquisition technology. The Los Alamos MEG system is based on the principal that fields from nearby sources measured by a SQUID sensor array while the SIS simultaneously shields the sensor array from distant noise fields. In general, Meissner currents flow in the surface of superconductors, preventing any significant penetration of magnetic fields. A hemispherical SIS with a brim, or helmet, surrounds the SQUID sensor array largely sheilding the SQUID sensors from sources outside the helmet. We present the general derivation of the forward model used to describe the effect of a SIS on source fields. Experimental data for the SIS-MEG system are compared with computed field distributions for a comprehensive set of sources.

Matlachov, A. N. (Andrei N.); Espy, M. A. (Michelle A.); Volegov, P. (Petr); Flynn, E. R. (Edward. R.); Maharajh, K. (Keeran); Kraus, Robert H., Jr.

2001-01-01T23:59:59.000Z

405

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

E-Print Network (OSTI)

??Superconductivity, charge- and spin-density waves are collective electronic phenomena that originate from electron-electron and electron-phonon interactions, and the concept of Fermi surface competition between these… (more)

Zocco, Diego Andrés

2011-01-01T23:59:59.000Z

406

Security Clearances; Limitations  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

SEC. 1072. SECURITY CLEARANCES; LIMITATIONS. SEC. 1072. SECURITY CLEARANCES; LIMITATIONS. (a) In General.-Title III of the Intelligence Reform and Terrorism Prevention Act of 2004 (50 U.S.C. 435b) is amended by adding at the end the following new section: "SEC. 3002. SECURITY CLEARANCES; LIMITATIONS. "(a) Definitions.-In this section: "(1) Controlled substance.-The term `controlled substance' has the meaning given that term in section 102 of the Controlled Substances Act (21 U.S.C. 802). "(2) Covered person.-The term `covered person' means- "(A) an officer or employee of a Federal agency; "(B) a member of the Army, Navy, Air Force, or Marine Corps who is on active duty or is in an active status; and "(C) an officer or employee of a contractor of a Federal agency.

407

PURPA and Superconducting Magnetic Energy Storage: Energy Conservation, Environmental Protection and Entrepreneurial Opportunity in the Next Technological Revolution  

E-Print Network (OSTI)

1988] SUPERCONDUCTING MAGNETIC ENERGY STORAGE Corp. ,60 theSupercon- ducting Magnetic Energy Storage, 2 SUPERCURRENTS1988] SUPERCONDUCTING MAGNETIC ENERGY STORAGE facilities (

Bovett, Robert E.

1988-01-01T23:59:59.000Z

408

Imaging Techniques for Relativistic Beams: Issues and Limitations  

Science Conference Proceedings (OSTI)

Characterizations of transverse profiles for low-power beams in the accelerators of the proposed linear colliders (ILC and CLIC) using imaging techniques are being evaluated. Assessments of the issues and limitations for imaging relativistic beams with intercepting scintillator or optical transition radiation screens are presented based on low-energy tests at the Fermilab A0 photoinjector and are planned for the Advanced Superconducting Test Accelerator at Fermilab. We have described several of the issues and limitations one encounters with the imaging of relativistic electron beams. We have reported our initial tests at the A0PI facility and our plans to extend these studies to the GeV scale at the ASTA facility. We also have plans to test these concepts with 23-GeV beams at the FACET facility at SLAC in the coming year. It appears the future remains bright for imaging techniques in ILC-relevant parameter space.

Lumpkin, Alex H.; Wendt, Manfred; /Fermilab

2012-02-01T23:59:59.000Z

409

Testing of 3-meter Prototype Fault Current Limiting Cables  

Science Conference Proceedings (OSTI)

Two 3-m long, single-phase cables have been fabricated by Ultera from second generation (2G) superconductor supplied by American Superconductor. The first cable was made with two layers of 2G tape conductor and had a critical current of 5,750 A while the second cable had four layers and a critical current of 8,500 A. AC loss was measured for both cables at ac currents of up to 4 kArms. Ultera performed initial fault current studies of both cables in Denmark with limited currents in the range from 9.1 to 44 kA. Results from these tests will provide a basis for a 25-m long, three-phase, prototype cable to be tested at ORNL early next year and a 300-m long, fault current limiting, superconducting cable to be installed in a ConEd substation in New York City.

Gouge, Michael J [ORNL; Duckworth, Robert C [ORNL; Demko, Jonathan A [ORNL; Rey, Christopher M [ORNL; Thompson, James R [ORNL; Lindsay, David T [ORNL; Tolbert, Jerry Carlton [ORNL; Willen, Dag [Ultera; Lentge, Heidi [Ultera; Thidemann, Carsten [Ultera; Carter, Bill [AMSC

2009-01-01T23:59:59.000Z

410

Electromagnetically induced interference at superconducting qubits  

E-Print Network (OSTI)

We study electromagnetically induced interference at superconducting qubits. The interaction between qubits and electromagnetic fields can provide additional coupling channels to qubit states, leading to quantum interference in a microwave driven qubit. In particular, the interwell relaxation or Rabi oscillation, resulting respectively from the multi- or single-mode interaction, can induce effective crossovers. The environment is modeled by a multi-mode thermal bath, generating the interwell relaxation. Relaxation induced interference, independent of the tunnel coupling, provides deeper understanding to the interaction between the qubits and their environment. It also supplies a useful tool to characterize the relaxation strength as well as the characteristic frequency of the bath. In addition, we demonstrate the relaxation can generate population inversion in a strongly driving two-level system. On the other hand, different from Rabi oscillation, Rabi oscillation induced interference involves more complicated and modulated photon exchange thus offers an alternative means to manipulate the qubit, with more controllable parameters including the strength and position of the tunnel coupling. It also provides a testing ground for exploring nonlinear quantum phenomena and quantum state manipulation, in not only the flux qubit but also the systems with no crossover structure, e.g. phase qubits.

Lingjie Du; Yang Yu

2010-12-14T23:59:59.000Z

411

Excitation Fields in a Superconducting Global String  

E-Print Network (OSTI)

A model of a straight superconducting global cosmic string is examined in a setting wherein the string supports a charge/current pulse described by a travelling wave along the string. Linearized field equations are obtained for fluctuations of the scalar and vector fields of the theory, and a set of approximate particular solutions are found for the case in which the linear charge density and the current of the string have equal magnitudes. Although the equations of motion seem to suggest that the scalar and vector excitation fields are massive inside the string core, the particular solutions show that they behave as effectively massless fields which propagate at the speed of light along the string along with the primary charge/current pulse. The effect of the mass parameter is to modulate the radial profile of the excitation fields. The vector excitation field generates radial and angular components for both the electric and magnetic fields, but the particular solutions do not describe the emission or absorption of electromagnetic radiation from the string.

J. R. Morris

1995-09-28T23:59:59.000Z

412

Strong Coupling BCS Superconductivity and Holography  

E-Print Network (OSTI)

We attempt to give a holographic description of the microscopic theory of a BCS superconductor. Exploiting the analogy with chiral symmetry breaking in QCD we use the Sakai-Sugimoto model of two D8 branes in a D4 brane background with finite baryon number. In this case there is a new tachyonic instability which is plausibly the bulk analog of the Cooper pairing instability. We analyze the Yang-Mills approximation to the non-Abelian Born-Infeld action. We give some exact solutions of the non-linear Yang-Mills equations in flat space and also give a stability analysis, showing that the instability disappears in the presence of an electric field. The holograhic picture also suggests a dependence of $T_c$ on the number density which is different from the usual (weak coupling) BCS. The flat space solutions are then generalized to curved space numerically and also, in an approximate way, analytically. This configuration should then correspond to the ground state of the boundary superconducting (superfluid) ground state. We also give some preliminary results on Green functions computations in the Sakai - Sugimoto model without any chemical potential

S. Kalyana Rama; Swarnendu Sarkar; B. Sathiapalan; Nilanjan Sircar

2011-04-14T23:59:59.000Z

413

Nonequilibrium transport in superconducting tunneling structures.  

SciTech Connect

We derive the current-voltage (I-V) characteristics of far from equilibrium superconducting tunneling arrays and find that the energy relaxation ensuring the charge transfer occurs in two stages: (i) the energy exchange between charge carriers and the intermediate bosonic agent, environment, and (ii) relaxing the energy further to the (phonon) thermostat, the bath, provided the rate of the environmental modes-phonon interactions is slower than their energy exchange rate with the tunneling junction. For a single junction we find I {proportional_to} (V/R)ln({Lambda}/V), where R is the bare tunnel resistance of the junction and {Lambda} is the high energy cut-off of the electron-environment interaction. In large tunneling arrays comprised of macroscopic number of junctions, low-temperature transport is governed by the cotunneling processes losing energy to the electron-hole environment. Below some critical temperature, T*, the Coulomb interactions open a finite gap in the environment excitations spectrum blocking simultaneously Cooper pair and normal excitations currents through the array; this is the microscopic mechanism of the insulator-to-superinsulator transition.

Chtchelkatchev, N. M.; Vinokur, V. M.; Baturina, T. I. (Materials Science Division); (Moscow Inst. Physics and Technology); (Inst. Semiconductor Physics)

2010-12-01T23:59:59.000Z

414

Superconductivity for Large Scale Wind Turbines  

SciTech Connect

A conceptual design has been completed for a 10MW superconducting direct drive wind turbine generator employing low temperature superconductors for the field winding. Key technology building blocks from the GE Wind and GE Healthcare businesses have been transferred across to the design of this concept machine. Wherever possible, conventional technology and production techniques have been used in order to support the case for commercialization of such a machine. Appendices A and B provide further details of the layout of the machine and the complete specification table for the concept design. Phase 1 of the program has allowed us to understand the trade-offs between the various sub-systems of such a generator and its integration with a wind turbine. A Failure Modes and Effects Analysis (FMEA) and a Technology Readiness Level (TRL) analysis have been completed resulting in the identification of high risk components within the design. The design has been analyzed from a commercial and economic point of view and Cost of Energy (COE) calculations have been carried out with the potential to reduce COE by up to 18% when compared with a permanent magnet direct drive 5MW baseline machine, resulting in a potential COE of 0.075 $/kWh. Finally, a top-level commercialization plan has been proposed to enable this technology to be transitioned to full volume production. The main body of this report will present the design processes employed and the main findings and conclusions.

R. Fair; W. Stautner; M. Douglass; R. Rajput-Ghoshal; M. Moscinski; P. Riley; D. Wagner; J. Kim; S. Hou; F. Lopez; K. Haran; J. Bray; T. Laskaris; J. Rochford; R. Duckworth

2012-10-12T23:59:59.000Z

415

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

416

Flywheel energy storage using superconducting magnetic bearings  

DOE Green Energy (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

417

Superconducting Electronics (Nato ASI Series (closed) / Nato ASI Subseries F, 1st edition  

Science Conference Proceedings (OSTI)

The book provides an in-depth understanding of the fundamentals of superconducting electronics and the practical considerations for the fabrication of superconducting electronic structures. Additionally, it covers in detail the opportunities afforded ...

Harold Weinstock; Martin Nisenoff

2012-07-01T23:59:59.000Z

418

A Superconducting Joint Technique for MgB[subscript 2] Round Wires  

E-Print Network (OSTI)

This paper describes a technique to superconductively splice multifilament MgB2 wires. To date the technique has achieved joints capable of carrying a superconducting current of 200 A at 10 K in self field. Joints details, ...

Yao, Weijun

419

Hall conductivity dominated by fluctuations near the superconducting transition in disordered thin films  

E-Print Network (OSTI)

We have studied the Hall effect in superconducting tantalum nitride films. We find a large contribution to the Hall conductivity near the superconducting transition, which we can track to temperatures well above T[subscript ...

Breznay, Nicholas P.

420

Phase Structure and Instability Problem in Color Superconductivity  

E-Print Network (OSTI)

We address the phase structure of color superconducting quark matter at high quark density. Under the electric and color neutrality conditions there appear various phases as a result of the Fermi surface mismatch among different quark flavors induced by finite strange quark mass; the color-flavor locked (CFL) phase where quarks are all energy gapped, the u-quark superconducting (uSC) phase where u-quarks are paired with either d- or s-quarks, the d-quark superconducting (dSC) phase that is the d-quark analogue of the uSC phase, the two-flavor superconducting (2SC) phase where u- and d-quarks are paired, and the unpaired quark matter (UQM) that is normal quark matter without pairing. Besides these possibilities, when the Fermi surface mismatch is large enough to surpass the gap energy, the gapless superconducting phases are expected. We focus our discussion on the chromomagnetic instability problem related to the gapless CFL (gCFL) onset and explore the instability regions on the phase diagram as a function of the temperature and the quark chemical potential. We sketch how to reach stable physical states inside the instability regions.

Kenji Fukushima

2005-10-22T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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.


421

ARPES Studies of Cuprate Fermiology: Superconductivity, Pseudogap and Quasiparticle Dynamics  

Science Conference Proceedings (OSTI)

We present angle-resolved photoemission spectroscopy (ARPES) studies of the cuprate high-temperature superconductors which elucidate the relation between superconductivity and the pseudogap and highlight low-energy quasiparticle dynamics in the superconducting state. Our experiments suggest that the pseudogap and superconducting gap represent distinct states, which coexist below T{sub c}. Studies on Bi-2212 demonstrate that the near-nodal and near-antinodal regions behave differently as a function of temperature and doping, implying that different orders dominate in different momentum-space regions. However, the ubiquity of sharp quasiparticles all around the Fermi surface in Bi-2212 indicates that superconductivity extends into the momentum-space region dominated by the pseudogap, revealing subtlety in this dichotomy. In Bi-2201, the temperature dependence of antinodal spectra reveals particle-hole asymmetry and anomalous spectral broadening, which may constrain the explanation for the pseudogap. Recognizing that electron-boson coupling is an important aspect of cuprate physics, we close with a discussion of the multiple 'kinks' in the nodal dispersion. Understanding these may be important to establishing which excitations are important to superconductivity.

Vishik, Inna

2011-06-23T23:59:59.000Z

422

Structural phase transitions and superconductivity in lanthanum copper oxides  

SciTech Connect

Despite the enormous effort expended over the past ten years to determine the mechanism underlying high temperature superconductivity in cuprates there is still no consensus on the physical origin of this fascinating phenomenon. This is a consequence of a number of factors, among which are the intrinsic difficulties in understanding the strong electron correlations in the copper oxides, determining the roles played by antiferromagnetic interactions and low dimensionality, analyzing the complex phonon dispersion relationships, and characterizing the phase diagrams which are functions of the physical parameters of temperature and pressure, as well as the chemical parameters of stoichiometry and hole concentration. In addition to all of these intrinsic difficulties, extrinsic materials issues such as sample quality and homogeneity present additional complications. Within the field of high temperature superconductivity there exists a subfield centered around the material originally reported to exhibit high temperature superconductivity by Bednorz and Mueller, Ba doped La{sub 2}CuO{sub 4}. This is structurally the simplest cuprate superconductor. The authors report on studies of phase differences observed between such base superconductors doped with Ba or Sr. What these studies have revealed is a fascinating interplay of structural, magnetic and superconducting properties which is unique in the field of high temperature superconductivity and is summarized in this paper.

Crawford, M.K.; Harlow, R.L.; McCarron, E.M. [DuPont, Wilmington, DE (United States)] [and others

1996-12-31T23:59:59.000Z

423

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

424

Failure Analysis of the Beam Vacuum in the Superconducting Cavities of the TESLA Main Linear Accelerator  

E-Print Network (OSTI)

1 Failure Analysis of the Beam Vacuum in the Superconducting Cavities of the TESLA Main Linear Hamburg, Germany Abstract For the long term successful operation of the superconducting TESLA accelerator The beam vacuum system of the TESLA main linear accelerators contains about 20.000 superconducting cavities

425

Development of a cryogenic induction motor for use with a superconducting magnetic bearing  

E-Print Network (OSTI)

Development of a cryogenic induction motor for use with a superconducting magnetic bearing Tomotake of a superconducting magnetic bearing (SMB). Both the motor and the SMB are operated at liquid He temperatures. We give Keywords: Astrophysical polarimeter; Induction motor; Superconducting magnetic bearings 1. Introduction

Oxley, Paul

426

Proceedings of the 1968 Summer Study on Superconducting Devices and  

NLE Websites -- All DOE Office Websites (Extended Search)

selected cryogenic data notebook selected cryogenic data notebook (Digitized and put on web from the original report : BNL 10200-R, Revised August 1980) Compiled and Edited by J.E. Jensen, W.A. Tuttle, R.B. Stewart, H. Brechna and A.G. Prodell Brookhaven National Laboratory NOTE: The indexing is primitive. A useful place to start may be the Subject Index A PDF viewer is required to see most articles. Cover Page Introduction Subject Index Expanded subject index (under construction) Disclaimer Click here to go to Material Properties Important to the Design of A Large Superconducting Magnet Click Here to View the Proceedings of the 1968 Summer Study on Superconducting Devices and Accelerators Go to the Home Page of the Superconducting Magnet Division (SMD) at BNL Go to the Workshop Page at SMD Go to the Publication Page at SMD

427

SUPERCONDUCTING DIPOLE MAGNETS FOR THE LHC INSERTION REGIONS  

NLE Websites -- All DOE Office Websites (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

428

New phase of matter discovered In superconducting material  

NLE Websites -- All DOE Office Websites (Extended Search)

New phase of matter discovered In superconducting material New phase of matter discovered In superconducting material New phase of matter discovered In superconducting material Tiny crystals, probed with a device called a resonant ultrasound spectrometer, are helping solve the long-time mystery of "pseudogap behavior" in copper oxide superconductors. June 6, 2013 Arkady Shekhter setting up the resonant ultrasound measurement in a flow cryostat. Arkady Shekhter setting up the resonant ultrasound measurement in a flow cryostat. Contact Nancy Ambrosiano Communications Office (505) 667-0471 Email News flash: The pseudogap is indeed a phase of matter. Albert Migliori, LANL Fellow and Seaborg Institute director noted that, "the key effects were so small that extreme attention to eliminating spurious signals

429

Uniformly wound superconducting coil and method of making same  

DOE Patents (OSTI)

A coil of superconducting wire for a superconducting magnet having a relaely dense and uniformly spaced winding to enhance the homogeneity and strength of the magnetic field surrounding the coil and a method of winding the same wherein the mandrel used to wind said coil comprises removable spacers and retainers forming a plurality of outwardly opening slots, each of said slots extending generally about the periphery of the mandrel and being sized to receive and outwardly align and retain successive turns of the superconducting wire within each slot as the wire is wound around and laterally across the mandrel to form a plurality of wire ribbons of a predetermined thickness laterally across the mandrel.

Mookerjee, Sumit (Cedar Hill, TX); Weijun, Shen (Beijun, CN); Yager, Billy (Waxahachie, TX)

1994-01-01T23:59:59.000Z

430

Method for producing strain tolerant multifilamentary oxide superconducting wire  

DOE Patents (OSTI)

A strain tolerant multifilamentary wire capable of carrying superconducting currents is provided comprising a plurality of discontinuous filaments formed from a high temperature superconducting material. The discontinuous filaments have a length at least several orders of magnitude greater than the filament diameter and are sufficiently strong while in an amorphous state to withstand compaction. A normal metal is interposed between and binds the discontinuous filaments to form a normal metal matrix capable of withstanding heat treatment for converting the filaments to a superconducting state. The geometry of the filaments within the normal metal matrix provides substantial filament-to-filament overlap, and the normal metal is sufficiently thin to allow supercurrent transfer between the overlapped discontinuous filaments but is also sufficiently thick to provide strain relief to the filaments.

Finnemore, Douglas K. (Ames, IA); Miller, Theodore A. (Tucson, AZ); Ostenson, Jerome E. (Ames, IA); Schwartzkopf, Louis A. (Mankato, MN); Sanders, Steven C. (Ames, IA)

1994-07-19T23:59:59.000Z

431

Superconducting Circuits for Quantum Simulation of Dynamical Gauge Fields  

E-Print Network (OSTI)

We describe a superconducting-circuit lattice design for the implementation and simulation of dynamical lattice gauge theories. We illustrate our proposal by analyzing a one-dimensional U(1) quantum-link model, where superconducting qubits play the role of matter fields on the lattice sites and the gauge fields are represented by two coupled microwave resonators on each link between neighboring sites. A detailed analysis of a minimal experimental protocol for probing the physics related to string breaking effects shows that despite the presence of decoherence in these systems, distinctive phenomena from condensed-matter and high-energy physics can be visualized with state-of-the-art technology in small superconducting-circuit arrays.

D. Marcos; P. Rabl; E. Rico; P. Zoller

2013-06-07T23:59:59.000Z

432

Renormalization group and the superconducting susceptibility of a Fermi liquid  

Science Conference Proceedings (OSTI)

A free Fermi gas has, famously, a superconducting susceptibility that diverges logarithmically at zero temperature. In this paper we ask whether this is still true for a Fermi liquid and find that the answer is that it does not. From the perspective of the renormalization group for interacting fermions, the question arises because a repulsive interaction in the Cooper channel is a marginally irrelevant operator at the Fermi liquid fixed point and thus is also expected to infect various physical quantities with logarithms. Somewhat surprisingly, at least from the renormalization group viewpoint, the result for the superconducting susceptibility is that two logarithms are not better than one. In the course of this investigation we derive a Callan-Symanzik equation for the repulsive Fermi liquid using the momentum-shell renormalization group, and use it to compute the long-wavelength behavior of the superconducting correlation function in the emergent low-energy theory. We expect this technique to be of broader interest.

Parameswaran, S. A.; Sondhi, S. L. [Department of Physics, Joseph Henry Laboratories, Princeton University, Princeton, New Jersey 08544 (United States); Shankar, R. [Department of Physics, Yale University, New Haven, Connecticut 06520 (United States)

2010-11-15T23:59:59.000Z

433

Corbino-geometry Josephson weak links in thin superconducting films  

Science Conference Proceedings (OSTI)

I consider a Corbino-geometry superconducting-normal-superconducting Josephson weak link in a thin superconducting film, in which current enters at the origin, flows outward, passes through an annular Josephson weak link, and leaves radially. In contrast to sandwich-type annular Josephson junctions, in which the gauge-invariant phase difference obeys the sine-Gordon equation, here the gauge-invariant phase difference obeys an integral equation. I present exact solutions for the gauge-invariant phase difference across the weak link when it contains an integral number N of Josephson vortices and the current is zero. I then study the dynamics when a current is applied, and I derive the effective resistance and the viscous drag coefficient; I compare these results with those in sandwich-type junctions. I also calculate the critical current when there is no Josephson vortex in the weak link but there is a Pearl vortex nearby.

Clem, John R.

2010-11-29T23:59:59.000Z

434

Uniformly wound superconducting coil and method of making same  

DOE Patents (OSTI)

A coil of superconducting wire for a superconducting magnet is described having a relatively dense and uniformly spaced winding to enhance the homogeneity and strength of the magnetic field surrounding the coil and a method of winding the same wherein the mandrel used to wind said coil comprises removable spacers and retainers forming a plurality of outwardly opening slots, each of said slots extending generally about the periphery of the mandrel and being sized to receive and outwardly align and retain successive turns of the superconducting wire within each slot as the wire is wound around and laterally across the mandrel to form a plurality of wire ribbons of a predetermined thickness laterally across the mandrel. 8 figures.

Mookerjee, S.; Weijun, S.; Yager, B.

1994-03-08T23:59:59.000Z

435

Graphite and its Hidden Superconductivity | Stanford Synchrotron Radiation  

NLE Websites -- All DOE Office Websites (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

436

Superconductivity in gallium-substituted Ba8Si46 clathrates  

E-Print Network (OSTI)

We report a joint experimental and theoretical investigation of superconductivity in Ga-substituted type-I silicon clathrates. We prepared samples of the general formula Ba8Si46-xGax, with different values of x. We show that Ba8Si40Ga6 is a bulk superconductor, with an onset at T-C approximate to 3.3 K. For x=10 and higher, no superconductivity was observed down to T=1.8 K. This represents a strong suppression of superconductivity with increasing Ga content, compared to Ba8Si46 with T-C approximate to 8 K. Suppression of superconductivity can be attributed primarily to a decrease in the density of states at the Fermi level, caused by a reduced integrity of the sp(3)-hybridized networks as well as the lowering of carrier concentration. These results are corroborated by first-principles calculations, which show that Ga substitution results in a large decrease of the electronic density of states at the Fermi level, which explains the decreased superconducting critical temperature within the BCS framework. To further characterize the superconducting state, we carried out magnetic measurements showing Ba8Si40Ga6 to be a type-II superconductor. The critical magnetic fields were measured to be H-C1 approximate to 35 Oe and H-C2 approximate to 8.5 kOe. We deduce the London penetration depth lambda approximate to 3700 A and the coherence length xi(c)approximate to 200 A. Our estimate of the electron-phonon coupling reveals that Ba8Si40Ga6 is a moderate phonon-mediated BCS superconductor.

Li, Yang; Zhang, Ruihong; Liu, Yang; Chen, Ning; Luo, Z. P.; Ma, Xingqiao; Cao, Guohui; Feng, Z. S.; Hu, Chia-Ren; Ross, Joseph H., Jr.

2007-01-01T23:59:59.000Z

437

Convergence of Ginzburg-Landau functionals in 3-d superconductivity  

E-Print Network (OSTI)

In this paper we consider the asymptotic behavior of the Ginzburg- Landau model for superconductivity in 3-d, in various energy regimes. We rigorously derive, through an analysis via {\\Gamma}-convergence, a reduced model for the vortex density, and we deduce a curvature equation for the vortex lines. In a companion paper, we describe further applications to superconductivity and superfluidity, such as general expressions for the first critical magnetic field H_{c1}, and the critical angular velocity of rotating Bose-Einstein condensates.

Sisto Baldo; Robert L. Jerrard; Giandomenico Orlandi; Mete Soner

2011-02-23T23:59:59.000Z

438

Superconductivity in Metal-mixed Ion-Implanted Polymer Films  

E-Print Network (OSTI)

Ion-implantation of normally insulating polymers offers an alternative to depositing conjugated organics onto plastic films to make electronic circuits. We used a 50 keV nitrogen ion beam to mix a thin 10 nm Sn/Sb alloy film into the sub-surface of polyetheretherketone (PEEK) and report the low temperature properties of this material. We observed metallic behavior, and the onset of superconductivity below 3 K. There are strong indications that the superconductivity does not result from a residual thin-film of alloy, but instead from a network of alloy grains coupled via a weakly conducting, ion-beam carbonized polymer matrix.

A. P. Micolich; E. Tavenner; B. J. Powell; A. R. Hamilton; M. T. Curry; R. E. Giedd; P. Meredith

2005-09-11T23:59:59.000Z

439

Quantum Information Transfer between Topological and Superconducting Qubits  

E-Print Network (OSTI)

We describe a scheme that enables a strong Jaynes-Cummings coupling between a topological qubit and a superconducting flux qubit. The coupling strength is dependent on the phase difference between two superconductors on a topological insulator and may be expediently controlled by a phase controller. With this coherent coupling and single-qubit rotations arbitrary unitary operations on the two-qubit hybrid system of topological and flux qubits can be performed. Numerical simulations show that quantum state transfer and entanglement distributing between the topological and superconducting flux qubits may be performed with high fidelity.

Fang-Yu Hong; Jing-Li Fu; Zhi-Yan Zhu

2013-01-19T23:59:59.000Z

440

Toroidal constant-tension superconducting magnetic energy storage units  

DOE Patents (OSTI)

A superconducting magnetic energy storage unit is provided in which the magnet is wound in a toroidal fashion such that the magnetic field produced is contained only within the bore of the magnet, and thus producing a very low external field. The superconducting magnet includes a coolant channel disposed through the wire. The bore of the magnet comprises a storage volume in which cryogenic coolant is stored, and this volume supplies the coolant to be delivered to the coolant channel in the magnet. 6 figs.

Herring, J.S.

1992-11-03T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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.
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441

Color superconductivity in ultra-dense quark matter  

E-Print Network (OSTI)

At ultra-high density, matter is expected to form a degenerate Fermi gas of quarks in which there is a condensate of Cooper pairs of quarks near the Fermi surface. This phenomenon is called color superconductivity. In these proceedings I review the underlying physics of color superconductivity and our current understanding of the possible phases of real-world quark matter. Then I consider how lattice gauge theorists would proceed to investigate the phase structure of dense quark matter if it were possible to perform the path integral numerically, i.e. if the sign problem had been solved.

Mark G. Alford

2006-10-06T23:59:59.000Z

442

Excitation of superconducting qubits from hot non-equilibrium quasiparticles  

E-Print Network (OSTI)

Superconducting qubits probe environmental defects such as non-equilibrium quasiparticles, an important source of decoherence. We show that "hot" non-equilibrium quasiparticles, with energies above the superconducting gap, affect qubits differently from quasiparticles at the gap, implying qubits can probe the dynamic quasiparticle energy distribution. For hot quasiparticles, we predict a non-neligable increase in the qubit excited state probability P_e. By injecting hot quasiparticles into a qubit, we experimentally measure an increase of P_e in semi-quantitative agreement with the model and rule out the typically assumed thermal distribution.

J. Wenner; Yi Yin; Erik Lucero; R. Barends; Yu Chen; B. Chiaro; J. Kelly; M. Lenander; Matteo Mariantoni; A. Megrant; C. Neill; P. J. J. O'Malley; D. Sank; A. Vainsencher; H. Wang; T. C. White; A. N. Cleland; John M. Martinis

2012-09-08T23:59:59.000Z

443

Review of Brookhaven National Laboratory superconducting power transmission program  

SciTech Connect

ABS>Research is being conducted at Brookhaven National Laboratory to develop a superconducting ac cable system leading to the construction of a 1/2 mile model cable of 200 MVA capacity at Brookhaven and a cable of larger (>2000 MVA) capacity for test at a utility testing site. It is a coaxial cable of flexible design using Nb/sub 3/Sn superconductor, and a tape wound dielectric, helium impregnated, of a material yet to be determined. The research development is reported on the dielectric materials, cryogenic enclosure, refrigeration, and superconducting materials. (MCW)

Jensen, J.E.

1973-10-11T23:59:59.000Z

444

Superconducting spoke cavities for high-velocity applications  

SciTech Connect

To date, superconducting spoke cavities have been designed, developed, and tested for particle velocities up to {beta}{sub 0}~0.6, but there is a growing interest in possible applications of multispoke cavities for high-velocity applications. We have explored the design parameter space for low-frequency, high-velocity, double-spoke superconducting cavities in order to determine how each design parameter affects the electromagnetic properties, in particular the surface electromagnetic fields and the shunt impedance. We present detailed design for cavities operating at 325 and 352 MHz and optimized for {beta}{sub 0}~=0.82 and 1.

Hopper, Christopher S. [Old Dominion U.; Delayen, Jean R. [Old Dominion U., JLAB

2013-10-01T23:59:59.000Z

445

Enhancement of superconductivity of lanthanum and yttrium sesquicarbide  

DOE Patents (OSTI)

A method of enhancing the superconductivity of body-centered cubic lanthanum and yttrium sesquicarbide through formation of the sesquicarbides from ternary alloys of novel composition (N/sub x/M/sub 1-x/)C/sub z/, where N is yttrium or lanthanum, M is thorium, any of the Group IV and VI transition metals, or gold, germanium or silicon, and z is approximately 1.2 to 1.6. These ternary sesquicarbides have superconducting transition temperatures as high as 17.0/sup 0/K.

Krupka, M.C.; Giorgi, A.L.; Krikorian, N.H.; Szklarz, E.G.

1971-06-22T23:59:59.000Z

446

Similarity-based fuzzy limits  

Science Conference Proceedings (OSTI)

In this paper the concept of similarity-based fuzzy limits in metric spaces is introduced and it is shown that it is an application of limit maps of topologies on [0,1]-valued sets, introduced by Hohle and Sostak, furthermore it is observed that the ... Keywords: Fuzzy limit, Limit map, Similarity-based fuzzy limit, [0,1]-Valued topology

Gültekin Soylu

2008-12-01T23:59:59.000Z

447

Cavity quantum electrodynamics for superconducting electrical circuits: an architecture for quantum computation  

E-Print Network (OSTI)

We propose a realizable architecture using one-dimensional transmission line resonators to reach the strong coupling limit of cavity quantum electrodynamics in superconducting electrical circuits. The vacuum Rabi frequency for the coupling of cavity photons to quantized excitations of an adjacent electrical circuit (qubit) can easily exceed the damping rates of both the cavity and the qubit. This architecture is attractive both as a macroscopic analog of atomic physics experiments and for quantum computing and control, since it provides strong inhibition of spontaneous emission, potentially leading to greatly enhanced qubit lifetimes, allows high-fidelity quantum non-demolition measurements of the state of multiple qubits, and has a natural mechanism for entanglement of qubits separated by centimeter distances. In addition it would allow production of microwave photon states of fundamental importance for quantum communication.

Alexandre Blais; Ren-Shou Huang; Andreas Wallraff; S. M. Girvin; R. J. Schoelkopf

2004-02-07T23:59:59.000Z

448

Cooling Strings of Superconducting Devices below 2 K the Helium II Bayonet Heat Exchanger  

E-Print Network (OSTI)

High-energy particle accelerators and colliders contain long strings of superconducting devices - acceleration RF cavities and magnets - operating at high field, which may require cooling in helium II below 2 K. In order to maintain adequate operating conditions, the applied or generated heat loads must be extracted and transported with minimum temperature difference. Conventional cooling schemes based on conductive or convective heat transport in pressurized helium II very soon reach their intrinsic limits of thermal impedance over extended lengths. We present the concept of helium II bayonet heat exchanger, which has been developed at CERN for the magnet cooling scheme of the Large Hadron Collider (LHC), and describe its specific advantages as a slim, quasi-isothermal heat sink. Experimental results obtained on several test set-ups, and a prototype magnet string have permitted to validate its performance and sizing rules, for transporting linear heat loads in the W.m-1 range over distances of several tens o...

Lebrun, P; Tavian, L; Van Weelderen, R

1998-01-01T23:59:59.000Z

449

Evidence for charge Kondo effect in superconducting Tl-doped PbTe  

SciTech Connect

We report results of low-temperature thermodynamic and transport measurements of Pb{sub 1-x}Tl{sub x}Te single crystals for Tl concentrations up to the solubility limit of approximately x = 1.5%. For all doped samples, we observe a low-temperature resistivity upturn that scales in magnitude with the Tl concentration. The temperature and field dependence of this upturn are consistent with a charge Kondo effect involving degenerate Tl valence states differing by two electrons, with a characteristic Kondo temperature T{sub K} {approx} 6 K. The observation of such an effect supports an electronic pairing mechanism for superconductivity in this material and may account for the anomalously high T{sub c} values.

Fisher, I

2010-01-11T23:59:59.000Z

450

Coherent output of photons from coupled superconducting transmission line resonators controlled by charge qubits  

E-Print Network (OSTI)

We study the coherent control of microwave photons propagating in a superconducting waveguide consisting of coupled transmission line resonators, each of which is connected to a tunable charge qubit. While these coupled line resonators form an artificial photonic crystal with an engineered photonic band structure, the charge qubits collectively behave as spin waves in the low excitation limit, which modify the band-gap structure to slow and stop the microwave propagation. The conceptual exploration here suggests an electromagnetically controlled quantum device based on the on-chip circuit QED for the coherent manipulation of photons, such as the dynamic creation of laser-like output from the waveguide by pumping the artificial atoms for population inversion.

Lan Zhou; Y. B. Gao; Z. Song; C. P. Sun

2006-08-26T23:59:59.000Z

451

(Limiting the greenhouse effect)  

SciTech Connect

Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

Rayner, S.

1991-01-07T23:59:59.000Z

452

(Limiting the greenhouse effect)  

SciTech Connect

Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

Rayner, S.

1991-01-07T23:59:59.000Z

453

Feasible utility scale Superconducting Magnetic Energy Storage system  

DOE Green Energy (OSTI)

This paper presents the latest design features and estimated costs of a 5000 MWh/1000 MW Superconducting Magnetic Energy Storage (SMES) plant. SMES is proposed as a commercially viable technology for electric utility load leveling. The primary advantage of SMES over other electrical energy storage technologies is its high net roundtrip efficiency. Other features include rapid availability and low maintenance and operating costs. Economic comparisons are made with other energy storage options and with gas turbines. In a diurnal load leveling application, a superconducting coil can be charged from the utility grid during off-peak hours. The ac grid is connected to the dc magnetic coil through a power conversion system that includes an inverter/rectifier. Once charged, the superconducting coil conducts current, which supports an electromagnetic field, with virtually no losses. During hours of peak load, the stored energy is discharged to the grid by reversing the charging process. The principle of operation of a SMES unit is shown in Fig. 1. For operation in the superconducting mode, the coil is maintained at extremely low temperature by immersion in a bath of liquid helium.

Loyd, R.J.; Schoenung, S.M.; Nakamura, T.; Lieurance, D.W.; Hilal, M.A.; Rogers, J.D.; Purcell, J.R.; Hassenzahl, W.V.

1986-01-01T23:59:59.000Z

454

Magnetoelastic instabilities and vibrations of superconducting-magnet systems  

SciTech Connect

This report describes the research accomplished under Depatment of Energy/NSF grants associated with the structural design of superconducting magnets for magnetic fusion reactors. The main results pertain to magnetomechanical instabilities in toroidal and poloidal field magnets for proposed fusion reactors. One major accomplishment was the building and testing of a 1/75th scale superconducting structural model of a 16 coil Tokamak reactor. Using this model the buckling of toroidal and poloidal field coils under different constraints was observed. A series of dynamic tests were performed, including the effect of currents on natural frequencies, poloidal-toroidal coil interaction, and buckling induced superconducting-normal quench of the coils. The stability of poloidal coils in a toroidal magnet field were investigated with the 16 coil torus. A superconducting poloidal coil was observed to become statically unstable or buckle as the current approached a certain value. Magnetoelastic buckling of other magnet systems such as a yin-yang pair of magnets, Ioffe coils, and discrete coil solenoids were also studied.

Moon, F.C.

1982-03-01T23:59:59.000Z

455

Interband transitions and interference effects in superconducting qubits  

Science Conference Proceedings (OSTI)

We investigate phase-sensitive interference effects in a periodically sin(2¿ f rf t)-driven, artificial two-state system connected to a microwave resonator at f LC ¿ 800 MHz. We observe two ... Keywords: 73.23.Hk, 85.25.Cp, 85.35.Gv, Aharonov---Anandan phase, Franck---Condon physics, Landau---Zener tunneling, Multiphoton transitions, Superconducting qubits

Antti Paila; Jani Tuorila; Mika Sillanpää; David Gunnarsson; Jayanta Sarkar; Yuriy Makhlin; Erkki Thuneberg; Pertti Hakonen

2009-06-01T23:59:59.000Z

456

Quantized geodesic flow and superconductivity of plasma in fireballs  

E-Print Network (OSTI)

An explanation of stability of fireballs is proposed based on quantum effects in a thin surface layer of negatively charged plasma surrounding a positive kernel of a fireball. We construct a quantization of the geodesic flow on the sphere and study the quantum statistics of fermions confined to a spherical surface. Analogy with the BCS theory of superconductivity is explored; spectral gap is estimated.

M. Zelikin

2007-02-21T23:59:59.000Z

457

Superconducting articles of manufacture and method of producing same  

SciTech Connect

Bulk coatings of Nb.sub.3 Ge with high superconducting transition temperatures bonded to metallic substrates and a chemical vapor deposition method for producing such coatings on metallic substrates are disclosed. In accordance with the method, a Nb.sub.3 Ge coating having a transition temperature in excess of 21.5 K may be tightly bonded to a copper substrate.

Newkirk, Lawrence R. (Los Alamos, NM); Valencia, Flavio A. (Santa Fe, NM)

1980-01-01T23:59:59.000Z

458

Development of superconducting transmission cable. CRADA final report  

SciTech Connect

The purpose of this Cooperative Research and Development Agreement (CRADA) between Oak Ridge National Laboratory (ORNL) and Southwire Company is to develop the technology necessary to proceed to commercialization of high-temperature superconducting (HTS) transmission cables. Power transmission cables are a promising near-term electric utility application for high-temperature superconductivity. Present HTS wires match the needs for a three-phase transmission cable: (1) the wires must conduct high currents in self-field, (2) there are no high forces developed, and (3) the cables may operate at relatively low current density. The commercially-available HTS wires, in 100-m lengths, make construction of a full three-phase, alternating current (ac) transmission cable possible. If completed through the pre-commercialization phase, this project will result in a new capability for electric power companies. The superconducting cable will enable delivery with greater efficiency, higher power density, and lower costs than many alternatives now on the market. Job creation in the US is expected as US manufacturers supply transmission cables to the expanding markets in Asia and to the densely populated European cities where pipe-type cable is prevalent. Finally, superconducting cables may enable delivery of the new, diverse and distributed sources of electricity that will constitute the majority of new installed electrical generation in the world during the coming decades.

Hawsey, R.; Stovall, J.P. [Oak Ridge National Lab., TN (United States); Hughey, R.L.; Sinha, U.K. [Southwire Co., Carrollton, GA (United States)

1997-10-01T23:59:59.000Z

459

Thermal aspects of a superconducting coil for fusion reactor  

SciTech Connect

Computer models are used to simulate both localized and extensive thermal excursions in a large superconducting magnet for fusion reactor. Conditions for the failure of fusion magnet due to thermal excursion are delineated. Designs to protect the magnet against such thermal excursion are evaluated. (auth)

Yeh, H.T.

1975-01-01T23:59:59.000Z

460

Microscopic Probes of High-Temperature Superconductivity  

Science Conference Proceedings (OSTI)

The granularity of the cuprate superconductors limits the effectiveness of many experimental probes that average over volumes containing many atoms. This report presents theoretical studies on muon spin relaxation and positron annihilation, two microscopic experimental techniques that can probe the properties of both high- and low-temperature superconductors on the atomic scale.

1992-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "limiting fcl superconducting" 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.


461

Perspectives: Superconductivity The Race to Beat the Cuprates  

E-Print Network (OSTI)

Superconductors are materials that lose all electrical resistance below a specific temperature, known as the critical temperature (Tc). Large-scale applications, for example, in superconducting cables, require materials with high (ideally room temperature) Tc’s, but most superconductors have very low Tc’s, typically a few kelvin or less. The discovery of a layered copper oxide (cuprate) with a Tc of 38 K (see panel A in the first figure) in 1986 [1] raised hopes that high temperature superconductivity might be within reach. By 1993, cuprate Tc’s of 133 K at ambient pressure had been achieved [2,3], but efforts to further increase cuprate Tc’s have not been fruitful. Two reports by Schön et al. [4,5] in the current issue of science –applying a similar technique to two very different materials – drastically alter the perception that planar cuprates are the only route to high temperature superconductivity. Schön et al. use a field-effect device introduced in previous investigations to transform insulating compounds into metals [6]. On page 2430, they show that copper oxide materials with a ladder structure (panel B in the first figure) can be superconducting [4], even without the high pressure applied in previous studies of related compounds. Even more spectacularly, they report on page 2432 that the Tc of a noncuprate molecular materials, C60 (panel C in the first figure), known before to superconduct at 52 K upon hole doping [7], can be raised by hole doping with intercalated CHBr3 to 117 K [5], not far from the cuprate record. Simple extrapolations suggest that the Tc could be increased even further, effectively ending the dominance of cuprates in the high-Tc arena.

Elbio Dagotto

2001-01-01T23:59:59.000Z

462

Investigation of superconducting and non-superconducting phases of Na?Ì£?CoO?·1.3H?0  

E-Print Network (OSTI)

The discovery of unconventional superconductivity in hydrated Na?Ì£?CoO?·1.3H?0 has lead to active research work on the material over the last year due to its similarities and possible insight into the high-T[sub]c copper ...

Garcia, Daniel Robert, 1982-

2004-01-01T23:59:59.000Z

463

High Temperature Superconductivity -- A Joint Feasibility Study for a Power Application with High-Temperature Superconducting Cable by Peco Energy  

Science Conference Proceedings (OSTI)

Practical realization of high temperature superconductivity (HTS) technology is within the electric power industry's reach. This report documents a feasibility study co-sponsored by PECO Energy Company (PECO) to assess a real-world underground transmission application of this technology.

1998-11-17T23:59:59.000Z

464

High Temperature Superconductivity -- A Joint Feasibility Study for a Power Application with High-Temperature Superconducting Cable by South Carolina  

Science Conference Proceedings (OSTI)

Practical realization of high temperature superconductivity (HTS) technology is within the reach of the electric power industry. This report documents a feasibility study co-sponsored by South Carolina Electric and Gas Company (SCE&G) to assess a real-world underground transmission application of this technology.

1998-11-17T23:59:59.000Z

465

Effects of potting on training and quench propagation in a large stored energy superconducting dipole coil  

DOE Green Energy (OSTI)

A superconducting racetrack dipole coil was constructed to compare directly training and quench behavior in potted and non-potted coils. The stored energy of this coil was 175 KJoules at the conductor's short sample limit of 238 Amp with a peak field on the coil of 7.6 Tesla. The outward magnetic forces were restrained by rows of tie rods between side plates. Comparisons of training behavior were made for both steel and aluminum tie rods. Helium flow was provided by channels in the fiberglass cable tape allowing 1/4 of the conductor direct access to the helium supply. After training the coil to 90% of short sample limit, the tie rods were relaxed and the entire coil was vacuum impregnated with a standard clear magnet epoxy. After potting, the previous tie rod preloads were re-established. This resulted in a much shallower training curve, and required retraining after thermal cycling. The unpotted coil showed no evidence of internal quench propagation below 80% short sample, whereas the potted coil exhibited good quench propagation and energy dissipation at all currents, simplifying protection strategies. Fully impregnated coils of this design are not practical for thermally cycled magnets designed to operate above 80% of short sample limit.

Cox, B.; Garbincius, P.H.; Guerra, J.; Mazur, P.O.; Satti, J.A.; Tilles, E.B.

1980-09-01T23:59:59.000Z

466

One Hundred Years of Superconductivity: Superconducting Materials and Electric Power Applications (465th Brookhaven Lecture)  

SciTech Connect

It was one hundred years ago this year that Dutch physicist Heike Kamerlingh Onnes discovered that by lowering the temperature of mercury to a blistering cold four degrees Kelvin, the metal became a “superconductor” and allowed electricity to flow through it with very little, if any, resistance. Fast forward one hundred years: now we are looking for new ways to store and transport energy — energy we can use to get from one place to another, stay comfortable when the weather outside is not, grow enough healthy food to feed the population, and sustain our ways of life — all while trying to protect the planet. Superconductors, with their potential to be über-energy efficient, are likely to play a crucial role in solving these challenges, and researchers at Brookhaven Lab are figuring out just how it can be done. Li will begin his talk with an overview of the first one hundred years of exploring superconductivity. He will also discuss the challenges of developing new superconductors and improving their performance for real-world energy applications, and then explain how basic science researchers at BNL are addressing those challenges.

Li, Qiang (BNL Condensed Matter Physics and Materials Science Department)

2011-01-19T23:59:59.000Z

467

Superconducting microcircuitry by the microlithographic patterning of superconducting compounds and related materials  

DOE Patents (OSTI)

A method is described of producing superconducting microcircuits comprising the steps of: depositing a thin film of Ba[sub 2]Cu[sub 3]O[sub 5+x](O < x < 1) onto a substrate; depositing a thin film of a dopant onto said thin film of Ba[sub 2]Cu[sub 3]O[sub 5+x]; depositing a photoresist onto said thin film of a dopant; shining light through a mask containing a pattern for a desired circuit configuration and onto said photoresist; developing said photoresist to remove portions of said photoresist shined by the light and to selectively expose said dopant film; etching said selectively exposed dopant film from said thin film of Ba[sub 2]Cu[sub 3]O[sub 5+x] to form a pattern of dopant; and heating said substrate at a temperature and for a period of time sufficient to diffuse and react said pattern of dopant with said thin film of Ba[sub 2]Cu[sub 3]O[sub 5+x].

Coppa, N.V.

1993-08-24T23:59:59.000Z

468

COMMENTARY:Limits to adaptation  

SciTech Connect

An actor-centered, risk-based approach to defining limits to social adaptation provides a useful analytic framing for identifying and anticipating these limits and informing debates over society s responses to climate change.

Preston, Benjamin L [ORNL

2013-01-01T23:59:59.000Z

469

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

NLE Websites -- All DOE Office Websites (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

470

High Field Magnet R&D |Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

471

A Toy Model Study of Decay Trapping | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

472

Project Fact Sheet Columbus HTS Power Cable Superconductivity  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Columbus Columbus HTS Power Cable Superconductivity Partnerships with Industry 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 This project involves field-testing of a long-length high-temperature superconducting (HTS) cable under real environmental stresses and real electrical loads. The cable system forms an important electrical link in a util- ity substation in Columbus, Ohio. What are its Primary aPPlications? HTS power cables are used for electricity transmission and distribution. The Columbus cable is a distribution cable, conducting electricity within a local grid. What are the Benefits to Utilities?

473

GSI Rapid Cycling Magnets Project | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (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

474

Superconductivity for Electric Systems: 2008 Annual Peer Review Final  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

for Electric Systems: 2008 Annual Peer Review for Electric Systems: 2008 Annual Peer Review Final Report Superconductivity for Electric Systems: 2008 Annual Peer Review Final Report The Office of Electricity Delivery and Energy Reliability's High Temperature Superconductivity (HTS) for Electric Systems Program's specific mission is to work in partnership with industry to develop HTS wire and perform other research and development activities leading to the commercialization of HTS-based electric power applications by U.S. companies. This technology contributes to several key performance improvements of the grid. It enhances reliability by increasing capacity, which relieves congestion and helps prevent outages. Efficiency is improved as a result of the reduction of loss during operation which both conserves

475

Project Fact Sheet Long Island HTS Power Cable Superconducting  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Long Long Island HTS Power Cable Superconducting 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 What is the status of the Project? The cable was energized April 22, 2008 and serves the equivalent of 300,000 homes. It is the first HTS power cable to operate at transmission voltage in the grid. LIPA plans to retain the superconductor as a permanent part of it's grid. This project involves the demonstration of a high- temperature superconducting (HTS) power cable in the Long Island Power grid, spanning nearly half a mile and serving as a permanent link in the Long Island Power

476

Realization and modeling of rf superconducting quantum interference device metamaterials  

E-Print Network (OSTI)

We have prepared meta-atoms based on radio frequency superconducting quantum interference devices (RF SQUIDs) and examined their tunability with dc magnetic field, rf current, and temperature. RF SQUIDs are superconducting split ring resonators in which the usual capacitance is supplemented with a Josephson junction, which introduces strong nonlinearity in the rf properties. We find excellent agreement between the data and a model which regards the Josephson junction as the resistively and capacitively-shunted junction. A magnetic field tunability of 80 THz/Gauss at 12 GHz is observed, a total tunability of 56$%$ is achieved, and a unique electromagnetically-induced transparency feature at intermediate excitation powers is demonstrated for the first time. An RF SQUID metamaterial is shown to have qualitatively the same behavior as a single RF SQUID with regards to DC flux and temperature tuning.

M. Trepanier; Daimeng Zhang; Oleg Mukhanov; Steven M. Anlage

2013-08-06T23:59:59.000Z

477

Dual superconductivity and vacuum properties in Yang--Mills theories  

E-Print Network (OSTI)

We address, within the dual superconductivity model for color confinement, the question whether the Yang-Mills vacuum behaves as a superconductor of type I or type II. In order to do that we compare, for the theory with gauge group SU(2), the determination of the field penetration depth $\\lambda$ with that of the superconductor correlation length $\\xi$. The latter is obtained by measuring the temporal correlator of a disorder parameter developed by the Pisa group to detect dual superconductivity. The comparison places the vacuum close to the border between type I and type II and marginally on the type II side. We also check our results against the study of directly measurable effects such as the interaction between two parallel flux tubes, obtaining consistent indications for a weak repulsive behaviour. Future strategies to improve our investigation are discussed.

A. D'Alessandro; M. D'Elia; L. Tagliacozzo

2006-07-12T23:59:59.000Z

478

Evidence for two-dimensional nucleation of superconductivity in  

E-Print Network (OSTI)

According to the crystal structure of MgB2 and band structure calculations quasi-two-dimensional (2D) boron planes are responsible for the superconductivity. We report on critical fields and resistance measurements of 30 nm thick MgB2 films grown on MgO single crystalline substrate. A linear temperature dependence of the parallel and perpendicular upper critical fields indicate a 3D-like penetration of magnetic field into the sample. Resistivity measurements, in contrast, yield a temperature dependence of fluctuation conductivity above Tc which agrees with the Aslamazov-Larkin theory of fluctuations in 2D superconductors. We consider this finding as an experimental evidence of two-dimensional nucleation of superconductivity in MgB2.

A. S. Sidorenko; L. R. Tagirov; A. N. Rossolenko; V. V. Ryazanov; R. Tidecks

2008-01-01T23:59:59.000Z

479

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

480

Simulating Zeno physics by quantum quench with superconducting circuits  

E-Print Network (OSTI)

Studying out-of-equilibrium physics in quantum systems under quantum quench is of vast experimental and theoretical interests. Using periodic quantum quenches, we present an experimentally accessible scheme to simulate the quantum Zeno and anti-Zeno effects in an open quantum system of a single superconducting qubit interacting with an array of transmission line resonators. The scheme is based on the following two observations: Firstly, compared with conventional systems, the short-time non-exponential decay in our superconducting circuit system is readily observed; and secondly, a quench-off process mimics an ideal projective measurement when its time duration is sufficiently long. Our results show that quantum quenches can serve as a promising decoherence control strategy.

Qing-Jun Tong; Jun-Hong An; L. C. Kwek; Hong-Gang Luo; C. H. Oh

2013-10-24T23:59:59.000Z

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481

Fast Ferroelectric L-Band Tuner for Superconducting Cavities  

Science Conference Proceedings (OSTI)

Design, analysis, and low-power tests are described on a ferroelectric tuner concept that could be used for controlling external coupling to RF cavities for the superconducting Energy Recovery Linac (ERL) in the electron cooler of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). The tuner configuration utilizes several small donut-shaped ferroelectric assemblies, which allow the design to be simpler and more flexible, as compared to previous designs. Design parameters for 704 and 1300 MHz versions of the tuner are given. Simulation results point to efficient performance that could reduce by a factor-of-ten the RF power levels required for driving superconducting cavities in the BNL ERL.

Jay L. Hirshfield

2012-07-03T23:59:59.000Z

482

Superconducting magnetic energy storage for electric power system dynamic stabilization  

DOE Green Energy (OSTI)

A Superconducting Magnetic Energy Storage (SMES) system is being developed at the Los Alamos Scientific Laboratory (LASL) for a dynamic stabilizer to be installed in the Bonneville Power Administration (BPA) power system at Tacoma, Washington, by 1982. This unit will be an alternate stabilization method to the dc modulator now used to stabilize the 900 mile, ac intertie between BPA and Southern California. The generation control systems' response to the constantly occuring, small-load and voltage changes can result in negatively damped, low-frequency power oscillations. The dc modulator provides stabilization by fast load control of the High-Voltage dc (HVDC). The SMES unit consists of a 30-MJ solenoid, a 10 MW convertor, a liquid helium dewar and auxiliary systems which operate independent of the HVDC system. The SMES dynamic stabilizer design is presented with status information about the superconducting coil, the converter and other components of the SMES dynamic stabilizer summarized.

Turner, R.

1979-01-01T23:59:59.000Z

483

Color Superconductivity in Compact Stars and Gamma Ray Bursts  

E-Print Network (OSTI)

We study the effects of color superconductivity on the structure and formation of compact stars. We show that it is possible to satisfy most of recent observational boundaries on masses and radii if a diquark condensate forms in a hybrid or a quark star. Moreover, we find that a huge amount of energy, of the order of $10^{53}$ erg, can be released in the conversion from a (metastable) hadronic star into a (stable) hybrid or quark star, if the presence of a color superconducting phase is taken into account. Accordingly to the scenario proposed in Astrophys.J.586(2003)1250, the energy released in this conversion can power a Gamma Ray Burst. This mechanism can explain the recent observations indicating a delay, of the order of days or years, between a few Supernova explosions and the subsequent Gamma Ray Burst.

A. Drago; A. Lavagno; G. Pagliara

2003-04-08T23:59:59.000Z

484

Superconducting Magnetic Energy Storage for electric power system dynamic stabilization  

DOE Green Energy (OSTI)

A Superconducting Magnetic Energy Storage (SMES) system is being developed at the Los Alamos Scientific Laboratory (LASL) for a dynamic stabilizer to be installed in the Bonneville Power Administration (BPA) power system at Tacoma, Washington, by 1982. This unit will be an alternate stabilization method to the dc modulator now used to stabilize the 900 mile, ac intertie between BPA and Southern California. The generation control systems' response to the constantly occurring, small-load and voltage changes can result in negatively damped, low-frequency power oscillations. The dc modulator provides stabilization by fast load control of the High-Voltage dc (HVDC). The SMES unit consists of a 30-MJ solenoid, a 10-MW convertor, a liquid helium dewar, and auxiliary systems which operate independent of the HVDC system. The SMES dynamic stabilizer design is presented and status information is given about the superconducting coil, the converter, and other components of the SMES dynamic stabilizer.

Turner, R.D.

1979-01-01T23:59:59.000Z

485

Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors  

SciTech Connect

We have found experimentally that the critical current of a square thin-film superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T, a behavior that has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. As a consequence, the effective transition temperature T{sub c} of the TES is current dependent and at fixed current scales as 1/L{sup 2}. We have also found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. We have observed the longitudinal proximity effect in these devices over extraordinarily long lengths up to 290 {micro}m, 1450 times the mean-free path.

Sadleir, John E.; Smith, Stephen J.; Bandler, Simon R.; Chervenak, James A.; Clem, John R.

2010-01-29T23:59:59.000Z

486

Superconducting magnetic energy storage for BPA transmission-line stabilization  

DOE Green Energy (OSTI)

The Bonneville Power Administration (BPA) operates the electrical transmission system that joins the Pacific Northwest with southern California. A 30 MJ (8.4 kWh) Superconducting Magnetic Energy Storage (SMES) unit with a 10 MW converter is being installed at the Tacoma Substation to provide system damping for low frequency oscillations of 0.35 Hz. The integrated system status is described and reviewed. Components included in the system are the superconducting coil, seismically mounted in an epoxy fiberglass nonconducting dewar; a helium refrigerator; a heat rejection subsystem; a high pressure gas recovery subsystem; a liquid nitrogen trailer; the converter with power transformers and switchgear; and a computer system for remote microwave link operation of the SMES unit.

Rogers, J.D.; Barron, M.H.; Boenig, H.J.; Criscuolo, A.L.; Dean, J.W.; Schermer, R.I.

1982-01-01T23:59:59.000Z

487

Method of manufacturing a niobium-aluminum-germanium superconductive material  

DOE Patents (OSTI)

A method for manufacturing flexible Nb.sub.3 (Al,Ge) multifilamentary superconductive material in which a sintered porous niobium compact is infiltrated with an aluminum-germanium alloy and thereafter deformed and heat treated in a series of steps at different successively higher temperatures preferably below 1000.degree. C. to produce filaments composed of Nb.sub.3 (Al,G3) within the compact. By avoiding temperatures in excess of 1000.degree. C. during the heat treatment, cladding material such as copper can be applied to facilitate a deformation step preceding the heat treatment and can remain in place through the heat treatment to also serve as a temperature stabilizer for supeconductive material produced. Further, these lower heat treatment temperatures favor formation of filaments with reduced grain size and, hence with more grain boundaries which in turn increase the current-carrying capacity of the superconductive material.

Wang, John L. (San Francisco, CA); Pickus, Milton R. (Oakland, CA); Douglas, Kent E. (Redondo Beach, CA)

1980-01-01T23:59:59.000Z

488

Limitations on Carry Lookahead Networks  

Science Conference Proceedings (OSTI)

The fan-in and fan-out limitations imposed by specific gate circuits force corresponding limits-upon the sizes of carry lookahead circuits fabricated from those gates. The relationships between those limits are derived, providing simple formulae that ... Keywords: high-speed arithmetic, Binary addition, carry lookahead

T. Rhyne

1984-04-01T23:59:59.000Z

489

Program on Technology Innovation: Superconducting DC Cable Workshop  

Science Conference Proceedings (OSTI)

This report is a summary of discussions and conclusion from a workshop on the technology of superconducting DC transmission cables. The workshop was held at EPRI in Palo Alto, California on October 12, 13, and 14, 2005. The purpose of the meeting was to bring a small group of experts in technologies relevant to the development of such a cable and to enumerate potential issues, technical challenges, and a timetable for development. The first half of the workshop consisted of short technical presentations,...

2006-03-31T23:59:59.000Z

490

Pressure Effects on Two Superconducting Iron-based Families  

SciTech Connect

Insight into the mechanism of high-temperature superconductivity can be gained by pressure-dependent studies of structural, thermodynamics and transport data. The role of pressure may be complicated by the level of hydrostaticity. High-pressure studies on two iron-based families of RFeAsO (R = rare-earth metals) and AFe{sub 2}As{sub 2} (A = alkaline-earth metals) are reviewed here.

Safa-Sefat, Athena [ORNL

2011-01-01T23:59:59.000Z

491

Microcomputer control for the superconducting magnetic energy storage system  

DOE Green Energy (OSTI)

The microcomputer-based, automatic control and data acquisition system for the Superconducting Magnetic Energy Storage system is described. A brief discussion of the function of SMES and identification of its major systems is followed by a detailed discussion of the control and data acquisition system. The distributed control and data acquisition architecture, interprocessor timing and communications, task scheduler, master-slave relationship, and man/machine interface are some of the topics discussed.

Seamons, M.J.; Criscuolo, A.L.

1981-01-01T23:59:59.000Z

492

The All Superconducting Substation: A Comparison with a Conventional Substation  

Science Conference Proceedings (OSTI)

Conventional substations today are quite similar in appearance to those of 50 years ago. However, substation components, efficiency, and safety have improved considerably in that time. If the improvements are to continue, different technologies will be required in the future. Superconducting devices such as transformers and cables are under development at present and may provide more efficient and more reliable service than conventional components. This report describes the effects of substituting superc...

2000-11-07T23:59:59.000Z

493

Superconducting Photonic Crystal with Nanostrips for Mid-Infrared Applications  

Science Conference Proceedings (OSTI)

One dimensional photonic crystal with superconducting nanostrips and semiconductor materials can be tailored to have narrow bands, with ei