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1

HTS Magnet Program | Superconducting Magnet Division  

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

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

2

Project Fact Sheet Columbus HTS Power Cable Superconductivity  

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

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?

3

Project Fact Sheet Long Island HTS Power Cable Superconducting  

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

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

4

5 - High temperature superconductor (HTS) magnets  

Science Journals Connector (OSTI)

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

H. Jones

2012-01-01T23:59:59.000Z

5

Superconductivity Program Overview High-Temperature Superconductivity  

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

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

6

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

SciTech Connect (OSTI)

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

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

2009-01-01T23:59:59.000Z

7

3 - High temperature superconductor (HTS) cables  

Science Journals Connector (OSTI)

Abstract: Many superconductor applications such as rotating machinery, transformers and magnets with low inductance require high current cables with low AC losses. This chapter gives an overview on cabling techniques for the high temperature superconductors (HTS) BSCCO (2212), BSCCO (2223) and (RE)BCO. A short review is given of the basic properties of HTS wires and tapes and the basic requirements of HTS cables for different applications. Cabling concepts for the different HTS materials are presented, and current performance and AC loss behaviour are discussed. After a short description of remaining challenges and future trends, cabling techniques are summarized.

S.I. Schlachter; W. Goldacker

2012-01-01T23:59:59.000Z

8

High Temperature Superconducting Underground Cable  

SciTech Connect (OSTI)

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

Farrell, Roger, A.

2010-02-28T23:59:59.000Z

9

High Temperature Superconducting Racetrack Coils for Electric Motor Applications  

Science Journals Connector (OSTI)

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

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

1997-01-01T23:59:59.000Z

10

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

E-Print Network [OSTI]

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

Weston, Ken

11

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

Science Journals Connector (OSTI)

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

Hua Jing; Suyu Wang; Ming Jiang; Jiasu Wang

2010-12-01T23:59:59.000Z

12

Acoustic microscopy for characterization of high?temperature superconducting tape  

Science Journals Connector (OSTI)

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

Chiaki Miyasaka; Chris Cobucci; Bernhard Tittmann

1997-01-01T23:59:59.000Z

13

4 - Bulk high temperature superconductor (HTS) materials  

Science Journals Connector (OSTI)

Abstract: This chapter concentrates on bulk materials. A bulk superconductor is one in which the superconductor has been formed into a lump, usually cylindrically shaped, but can also be hexagonal, rectangular or even square. Bulk superconductors are typically 3–5 cm across and 1 cm thick. They have many uses but the principal one is as extremely compact high-field permanent magnets in superconducting machines. A 2.6 cm (RE)BCO puck has been magnetised to 17.24 T: this is an order of magnitude greater than the flux density available from a conventional permanent magnet. This chapter describes the materials, manufacturing process, magnetisation process and some examples of machines.

T. Coombs

2012-01-01T23:59:59.000Z

14

Cryogenic System for a High Temperature Superconducting Power Transmission Cable  

SciTech Connect (OSTI)

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

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

1999-07-12T23:59:59.000Z

15

Spontaneous quenches of a high temperature superconducting pancake coil  

SciTech Connect (OSTI)

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

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

1995-09-01T23:59:59.000Z

16

Spontaneous quenches of a high temperature superconducting pancake coil  

SciTech Connect (OSTI)

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

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

1996-07-01T23:59:59.000Z

17

High temperature superconductive flux gate magnetometer  

SciTech Connect (OSTI)

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

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

1991-03-01T23:59:59.000Z

18

Test of two prototype high-temperature superconducting transmission cables  

SciTech Connect (OSTI)

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

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

1996-10-01T23:59:59.000Z

19

Papers on HTS  

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

visit Superconducting Magnet Division Webpage on HTS Magnet visit Superconducting Magnet Division Webpage on HTS Magnet Program at BNL. List of publications on HTS with Ramesh Gupta as the major author (unless noted): R. Gupta, et al., "High Field HTS Solenoid for a Muon Collider – Demonstrations, Challenges and Strategies, MT23, July 2013", presented at MT23, (talk) R. Gupta, et al., "Design Construction and Test Results of a HTS Solenoid for Energy Recovery Linac", 2011 Particle Accelerator Conference, New York (POSTER). ***BNL Papers Submitted on HTS at PAC2011*** R. Gupta, M. Anerella, A. Ghosh, H. Kirk, R. Palmer, S. Plate, W. Sampson, Y. Shiroyanagi, P. Wanderer, B. Brandt, D. Cline, A. Garren, J. Kolonko, R. Scanlan, R. Weggel, "High field HTS R&D solenoid for muon collider",

20

Philosophy 26 High Temperature Superconductivity  

E-Print Network [OSTI]

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

Callender, Craig

Note: This page contains sample records for the topic "temperature superconducting hts" 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

Definition: Very Low Impedance (Hts) Cables | Open Energy Information  

Open Energy Info (EERE)

Very Low Impedance (Hts) Cables Very Low Impedance (Hts) Cables Jump to: navigation, search Dictionary.png Very Low Impedance (Hts) Cables Cables that use conducting materials that are very low impedance, which can enable better power flow control. Cables that use high temperature superconducting (HTS) conductor would be characterized as a VLI cable. HTS cables may enable additional benefits such as lower losses, increased power density, and self-fault limiting.[1] Related Terms power, power flow control References ↑ [www.smartgrid.gov/sites/default/files/pdfs/description_of_assets.pdf SmartGrid.gov 'Description of Assets'] An i LikeLike UnlikeLike You like this.Sign Up to see what your friends like. nline Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Very_Low_Impedance_(Hts)_Cables&oldid=480440

22

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

E-Print Network [OSTI]

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

Chang, Ho-Myung

23

Magnetic saturable reactor type HTS fault current limiter for electrical application  

Science Journals Connector (OSTI)

An electrical fault current limiter (FCL) developed based on the principle of a magnetic saturable reactor requires a high current ampere-turn coil as its dc bias, and this coil is necessary to use a high temperature superconducting (HTS) winding. This HTS FCL has been studied, and identified with several advantages compared to other HTS FCLs, and therefore is further considered for its practical industry application.

J.X. Jin; S.X. Dou; C. Cook; C. Grantham; M. Apperley; T. Beales

2000-01-01T23:59:59.000Z

24

High Temperature Superconducting Fault Current Limiter for Utility Applications  

Science Journals Connector (OSTI)

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

E. M. W. Leung; G. W. Albert; M. Dew…

1997-01-01T23:59:59.000Z

25

Quench development in a high temperature superconducting tape  

SciTech Connect (OSTI)

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

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

1996-12-31T23:59:59.000Z

26

Quench development in a high temperature superconducting tape  

SciTech Connect (OSTI)

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

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

1995-12-01T23:59:59.000Z

27

Design and PHILS-based Transient Analysis of a Tri-axial HTS Power Cable  

Science Journals Connector (OSTI)

Abstract Tri-axial high-temperature superconducting (HTS) power cables are very efficient compared with other HTS power cables due to their reduced use of HTS wires and cryogenic surface area, resulting from the mutually layered structure of the three phases. However, the operating characteristics of tri-axial HTS power cables differ from other cables in a transient-state condition. In order to install HTS power cables in a real grid, feasibility verification through simulation or experimentation is required in advance. Thus, the authors design a tri-axial HTS power cable and implement a power hardware-in-the-loop simulation that consists of a real time digital simulator-based simulation model and hardware devices including a power supply and a 1 m-long tri-axial HTS model cable. Simulation results show the stability verification under steady-state and transient-state conditions.

Sun-Kyoung Ha; Chang-Soon Kim; Sung-Kyu Kim; Minh-Chau Dinh; Jin-Geun Kim; Minwon Park; In-Keun Yu; Sangjin Lee; Kideok Sim

2014-01-01T23:59:59.000Z

28

10 - Application of high temperature superconductor (HTS) technology in rotating machinery  

Science Journals Connector (OSTI)

Abstract: This chapter discusses the application of high temperature superconductors (HTS) to generators and motors. It first reviews the benefits and rationale for applying HTS technology to generators and motors. It then describes compromises affecting the electromagnetic, mechanical and thermal design for such machines. The different types of machine topology possible, their respective advantages and disadvantages and their Key performance characteristics compared to equivalent conventional machines are then outlined. Issues with developing such machines within an industrial production environment and their installation and operation within a demanding commercial environment are discussed. Challenges facing the design, build, testing and commissioning of such machines are reviewed, with a discussion of future machine and equipment requirements and trends.

R. Fair

2012-01-01T23:59:59.000Z

29

Development, Updating and Long-Term Operations of a 10.5 kV HTS Fault Current Limiter  

Science Journals Connector (OSTI)

There are many irreplaceable advantages of high temperature superconducting (HTS) fault current limiter, applying in electric utilities. It is expected to be able to solve excessive fault current problems and to ...

J. Zhang; S. Dai; Y. Teng; D. Zhang; N. Song…

2014-10-01T23:59:59.000Z

30

LANL: Superconductivity Technology Center  

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

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

31

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

DOE Patents [OSTI]

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

Hull, John R. (Downers Grove, IL)

2000-01-01T23:59:59.000Z

32

Superconductivity for Electric Systems Program Review LANL Contributions to GE HTS Generator  

E-Print Network [OSTI]

-section · Develop a heat generation profile => thermal analysis #12;Superconductivity for Electric Systems Program of coolant loop to verify heat due to flow work on helium #12;Superconductivity for Electric Systems Program for Electric Systems Program Review Stationary heat pipe tests were necessary to determine performance impact

33

DEVELOPMENT OF HTS CONDUCTORS FOR ELECTRIC POWER APPLICATIONS  

SciTech Connect (OSTI)

Second generation (2G) technologies to fabricate high-performance superconducting wires developed at the Oak Ridge National Laboratory (ORNL) were transferred to American Superconductor via this CRADA. In addition, co-development of technologies for over a decade was done to enable fabrication of commercial high-temperature superconducting (HTS) wires with high performance. The massive success of this CRADA has allowed American Superconductor Corporation (AMSC) to become a global leader in the fabrication of HTS wire and the technology is fully based on the Rolling Assisted Biaxially Textured Substrates (RABiTS) technology invented and developed at ORNL.

Goyal, A.; Rupich, M. (American Superconductor Corp.)

2012-10-23T23:59:59.000Z

34

Engineering Division Superconducting  

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

10152014 Joseph V. Minervini 74 35 MW superconducting motor Superconducting Fault Current Limiter (SCFL) Technology & Engineering Division HTS (MgB 2 ) * DC superconducting...

35

Engineering Design of A High-Temperature Superconductor Current Lead  

Science Journals Connector (OSTI)

As part of the U.S. Department of Energy’s Superconductivity Pilot Center Program, Argonne National Laboratory and Superconductivity, Inc., are developing high-temperature superconductor (HTS) current leads suita...

R. C. Niemann; Y. S. Cha; J. R. Hull; M. A. Daugherty; W. E. Buckles

1994-01-01T23:59:59.000Z

36

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

SciTech Connect (OSTI)

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

Energetics, Inc.

2000-01-01T23:59:59.000Z

37

HTS Wire Development Workshop: Proceedings  

SciTech Connect (OSTI)

The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

Not Available

1994-07-01T23:59:59.000Z

38

Decompression cooling system operation for HTS power cable in the KEPCO power grid  

Science Journals Connector (OSTI)

A 3-phase 22.9 kV/50 MVA 410 m HTS power cable system was installed at power grid of KEPCO and had been operated for 20 months. In the HTS cable system an open type cooling system was constructed for cooling LN2 using as coolant for superconducting cable. The cooling capacity of the cooling system was 6 kW at 69 K. Subcooled LN2 flew thorough 410 m HTS cable maintaining 69 K of operating temperature for HTS cable. The electric load had fluctuated continuously with the load status so that the cooling state was also controlled to keep stable operating condition. The consumed LN2 used for making subcooled state was refilled periodically and the amount was 3 tons in average. During all the operating period the HTS cable system supplied electric power stably without any problem.

2014-01-01T23:59:59.000Z

39

Potential and desire for HTS application in thermonuclear fusion  

Science Journals Connector (OSTI)

Superconducting magnets are stringent for fusion reactors with magnetic confinement to provide an economic energy balance. Large-scale development programmes have been executed worldwide to achieve in time the needed technology. The ultimate result of this effort, so far, is the ITER magnet system with the most sophisticated LTS. However, if one thinks about the design of a fusion DEMO and later reactors, the option of HTS must be considered seriously in view of the potential advantages of these conductors concerning higher operation temperature, temperature margin, high field properties and cryogenic power saving. Extrapolating from the long period needed for the ITER conductor development, it is time now to start with HTS development for fusion reactors to be able to decide their applicability. It is still a long way for the HTS to become comparable with LTS, however, continuous progress can be seen. Beside the large confinement magnets, HTS will also be of advantage for current leads, bus bars and gyrotron magnets. The state of the art of HTS is such, that already now such components can be constructed with HTS.

P. Komarek

2006-01-01T23:59:59.000Z

40

atlas superconducting magnet: Topics by E-print Network  

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

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

Note: This page contains sample records for the topic "temperature superconducting hts" 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

HTS Cable Projects  

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

Superconductivity Superconductivity Partnerships with Industry ANL Air Liquide DOE Golden LANL AEP ORNL Nexans Niagara Mohawk Super Power American Superconductor NYSERDA BOC Praxair W ? tion systems. This is the most the nation. W superconductivity? HTS Cable Projects 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

42

Extending the range of applicability of HTS cylinders in inductive superconducting fault current limiters  

Science Journals Connector (OSTI)

In the numerical routine used to estimate the temperature of the weak zones (channels) an error was introduced. Once the error is eliminated, the improvement in the thermal refrigeration of the inductive fault current limiters with artificial weak zones still remains but its importance is reduced; a channelled cylinder can refrigerate faster than a non-channelled one, as heat is removed also by conduction to the cold parts, but under a current fault the temperature of the weak zones is very much above those displayed in figure 3(b) and figure 4 (140 K is our best result, Tc being 105 K). As a consequence, the channelled cylinder needs about 9 s to get the critical temperature for the nominal current, whereas the non-channelled cylinder requires more than 15 s (both refrigerated by liquid nitrogen). Although appreciable, this improvement is still far from the usually required recovery time, which is about 1 s. This design could be more appropriate for a fault current limiter working in a slightly lower power grid or in a gaseous atmosphere, where the channelled sample is definitely much better than the non-channelled cylinder. To be competitive when operating in liquid nitrogen some additional mechanism should be implemented to avoid the excessive heating of the weak zones.

M R Osorio; J A Lorenzo; J A Veira; F Vidal

2008-01-01T23:59:59.000Z

43

Review of activities in USA on HTS materials  

SciTech Connect (OSTI)

Rapid progress in attaining practical applications of High Temperature Superconductors (HTS) has been made since the discovery of these new materials. Many critical parameters influencing HTS powder synthesis and wire processing have been identified through a combination of fundamental exploration and applied research. The complexity of these novel materials with regard to phase behavior and physical properties has become evident as a result of these careful studies. Achieving optimal mechanical and superconducting properties in wires and tapes will require further understanding and synergy among several different technical disciplines. Highlights of efforts towards producing practical superconductors for electric power applications based on rare earth-, bismuth-, and thallium-based systems are reviewed.

Peterson, D.E.

1995-02-01T23:59:59.000Z

44

Thermal management of long-length HTS cable systems  

SciTech Connect (OSTI)

Projections of electric power production suggest a major shift to renewables, such as wind and solar, which will be in remote locations where massive quantities of power are available. One solution for transmitting this power over long distances to load centers is direct current (dc), high temperature superconducting (HTS) cables. Electric transmission via dc cables promises to be effective because of the low-loss, highcurrent- carrying capability of HTS wire at cryogenic temperatures. However, the thermal management system for the cable must be carefully designed to achieve reliable and energyefficient operation. Here we extend the analysis of a superconducting dc cable concept proposed by the Electric Power Research Institute (EPRI), which has one stream of liquid nitrogen flowing in a cryogenic enclosure that includes the power cable, and a separate return tube for the nitrogen. Refrigeration stations positioned every 10 to 20 km cool both nitrogen streams. Both go and return lines are contained in a single vacuum/cryogenic envelope. Other coolants, including gaseous helium and gaseous hydrogen, could provide potential advantages, though they bring some technical challenges to the operation of long-length HTS dc cable systems. A discussion of the heat produced in superconducting cables and a system to remove the heat are discussed. Also, an analysis of the use of various cryogenic fluids in long-distance HTS power cables is presented.

Demko, Jonathan A [ORNL; Hassenzahl, William V [ORNL

2011-01-01T23:59:59.000Z

45

Analysis on heat loss characteristics of a 10 kV HTS power substation  

Science Journals Connector (OSTI)

Abstract A 10 kV High Temperature Superconducting power substation (10 kV HTS substation), supported by Chinese State 863 projects, was developed and has been running to supply power for several factories for more than two years at an industrial park of Baiyin, Gansu province in Northwest China. The system of the 10 kV HTS substation compositions, including a HTS cable, a HTS transformer, a SFCL, and a SMES, are introduced. The SMES works at liquid helium temperature and the other three apparatus operates under liquid nitrogen condition. There are mainly four types of heat losses existing in each HTS apparatus of the 10 kV HTS substation, including AC loss, Joule heat loss, conductive heat, and leak-in heat from cryostat. A small quantity of AC loss still exists due to the harmonic component of the current when it carries DC for HTS apparatus. The principle and basis for analysis of the heat losses are introduced and the total heat loss of each apparatus are calculated or estimated, which agree well with the test result. The analysis and result presented are of importance for the design of the refrigeration system.

Yuping Teng; Shaotao Dai; Naihao Song; Jingye Zhang; Zhiyuan Gao; Zhiqin Zhu; Weiwei Zhou; Zhourong Wei; Liangzhen Lin; Liye Xiao

2014-01-01T23:59:59.000Z

46

High-Temperature Superconductivity Cable Demonstration Projects  

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

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

47

Report on discussions with utility engineers about superconducting generators  

SciTech Connect (OSTI)

This report relates to a series of discussions with electric utility engineers concerning the integration of high-temperature superconducting (HTS) generators into the present electric power system. The current and future interest of the utilities in the purchase and use of HTS generators is assessed. Various performance and economic factors are also considered as part of this inspection of the utility prospects for HTS generators. Integration of HTS generators into the electric utility sector is one goal of the Superconductivity Partnership Initiative (SPI). The SPI, a major part of the Department of Energy (DOE) Superconductivity Program for Electric Systems, features vertical teaming of a major industrial power apparatus manufacturers, a producer of HTS wire, and an end-user with assistance and technical support for the national laboratories. The SPI effort on HTS generators is headed by a General Electric Corporation internal team comprised of the Corporate Research Laboratories, Power Generation Engineering, and Power Systems Group. Intermagnetics General corporation, which assisted in the development of the superconducting coils, is the HTS wire and tape manufacturer. Additional technical support is provided by the national laboratories: Argonne, Los Alamos, and Oak Ridge, and the New York State Institute on Superconductivity. The end-user is represented by Niagara-Mohawk and the Electric Power Research Institute.

none,

1996-03-01T23:59:59.000Z

48

Design Construction and Test Results of a HTS Solenoid for Energy Recovery Linac  

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

DESIGN CONSTRUCTION AND TEST RESULTS OF A HTS SOLENOID DESIGN CONSTRUCTION AND TEST RESULTS OF A HTS SOLENOID FOR ENERGY RECOVERY LINAC* R. Gupta # , M. Anerella, I. Ben-Zvi, G. Ganetis, D. Kayran, G. McIntyre, J. Muratore, S. Plate and W. Sampson, Brookhaven National Laboratory, Upton, NY, 11973 USA and M. Cole and D. Holmes, Advanced Energy Systems, Inc., Medord, NY, 11763 USA Abstract An innovative feature of the proposed Energy Recovery Linac (ERL) is the use of a solenoid made with High Temperature Superconductor (HTS) with the Superconducting RF cavity. The use of HTS allows solenoid to be placed in close proximity to the cavity and thus provides early focusing of the electron beam. In addition, cryogenic testing at ~77 K is simpler and cheaper than 4 K testing. This paper will present the

49

Pseudogap and Superconducting Gap in High-Temperature Superconductors  

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

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

50

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

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

51

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

SciTech Connect (OSTI)

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

Forbes, D.

1996-04-01T23:59:59.000Z

52

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

SciTech Connect (OSTI)

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

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

2013-02-13T23:59:59.000Z

53

Stability and quench protection of high-temperature superconductors  

E-Print Network [OSTI]

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

Ang, Ing Chea

2006-01-01T23:59:59.000Z

54

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

55

A simple figure of merit for high temperature superconducting switches  

SciTech Connect (OSTI)

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

Honig, E.M.

1989-01-01T23:59:59.000Z

56

Modular test facility for HTS insert coils  

SciTech Connect (OSTI)

The final beam cooling stages of a Muon Collider may require DC solenoid magnets with magnetic fields in the range of 40-50 T. In this paper we will present a modular test facility developed for the purpose of investigating very high field levels with available 2G HTS superconducting materials. Performance of available conductors is presented, together with magnetic calculations and evaluation of Lorentz forces distribution on the HTS coils. Finally a test of a double pancake coil is presented.

Lombardo, V; Bartalesi, A.; Barzi, E.; Lamm, M.; Turrioni, D.; Zlobin, A.V.; /Fermilab

2009-10-01T23:59:59.000Z

57

Stability and Quench Protection for HTS Superconducting Magnets: Cooperative Research and Development Final Report, CRADA number CRD-05-00160  

SciTech Connect (OSTI)

NREL will perform deposition and testing of various dielectrics on high-temperature superconductors.

Ginley, D. S.

2010-07-01T23:59:59.000Z

58

Superconducting technology program Sandia 1996 annual report  

SciTech Connect (OSTI)

Sandia`s Superconductivity Technology Program is a thallium-based high-temperature superconductor (HTS) research and development program consisting of efforts in powder synthesis and process development, open-system thick film conductor development, wire and tape fabrication, and HTS motor design. The objective of this work is to develop high-temperature superconducting conductors (wire and tape) capable of meeting requirements for high-power electrical devices of interest to industry. The research efforts currently underway are: (1) Process development and characterization of thallium-based high-temperature superconducting closed system wire and tape, (2) Investigation of the synthesis and processing of thallium-based thick films using two-zone processing, and (3) Cryogenic design of a 30K superconducting motor. This report outlines the research that has been performed during FY96 in each of these areas.

Roth, E.P.

1997-02-01T23:59:59.000Z

59

Ramesh Gupta | Superconducting Magnet Division  

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

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

60

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

Science Journals Connector (OSTI)

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

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

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

Numerical Analysis of Heat Transfer and Fluid Characteristics of Flowing Liquid Nitrogen in HTS Cable  

Science Journals Connector (OSTI)

Abstract High-temperature superconducting (HTS) cable has heat intrusion from the termination including joule heat generation at the terminal joint and from the room temperature cable through the Cu current lead. According to the length of the HTS cable, this heat loss may become a considerable amount which cannot be ignored in the HTS cable system. In this study, referring to a high-voltage cable (HV cable) which was developed in M-PACC project, the effect of heat transfer at the interface between the terminal joint and LN2 in the terminal vessel (ho) on the temperature of the HTS cable were calculated and evaluated. The condition of flow in the terminal vessel was assumed to be natural convection, forced flow or static condition for evaluating this effect with various heat transfer condition. As a result, in the case of the natural convection, most of heats flow into the LN2 in the terminal vessel where the volumetric flow of the LN2 is large since ho becomes high. Accordingly, the temperature rise of the LN2 in the inner pipe of Cu former and the terminal vessel can be restricted. However, in the cases of the forced flow and the static condition, most of heats flow into the LN2 in the inner pipe where the volumetric flow of the LN2 is small since ho becomes small. Accordingly, the temperature rise of the LN2 in the inner pipe becomes high. This temperature rise of the LN2 in the inner pipe makes the temperature of the HTS conductor large resulting in remarkable increase of AC losses. Consequently, on the HV cable design, for restriction of the AC loss increase, it is expected that designing the HTS cable termination such as extending outer surface of the terminal joint for increasing of the heat inflow from the terminal joint to the LN2 in the vessel is effective.

O. Maruyama; T. Ohkuma; T. Izumi; Y. Shiohara

2014-01-01T23:59:59.000Z

62

HTS coil development and fabrication. Final report  

SciTech Connect (OSTI)

The objective of this subtask (Task 2C) was to develop high-temperature superconductor (HTS) coil technology aimed specifically at superconducting generator applications. Bi-2223 tape produced in a separate subtask (Task 2A) was first wound and tested in a small circular coil. This small coil winding experience led the authors to develop a tape strengthening method using a lamination process and to develop a turn insulation method using a paper wrap process. A prototype racetrack coil was wound using 2500 feet of the laminated and insulated Bi-2223 tapes. The racetrack coil was cooled to 20K in a vacuum dewar using a unique closed-cycle helium gas refrigeration system.

Herd, K.G.; Salasoo, L.; Ranze, R. [and others

1996-10-01T23:59:59.000Z

63

Superconductivity for electric systems program plan, FY 1996--FY 2000  

SciTech Connect (OSTI)

This describes a comprehensive, integrated approach for the development of HTS (high-temperature superconductivity) technology for cost-effective use in electric power applications. This approach supports the program`s mission: to develop the technology that could lead to industrial commercialization of HTS electric power applications, such as fault-current limiters, motors, generators, transmission cables, superinductors, and superconducting energy storage. The vision is that, by 2010, the US power systems equipment industry will regain a major share of the global market by offering superconducting products that outperform the competition; and in US, the power grid will gain increased efficiency and stability by incorporating many kinds of HTS devices. After an overview and a discussion of the program plan (wires, systems technology, partnership initiative), this document discusses technology status, stakeholders, and the role of US DOE.

NONE

1996-03-01T23:59:59.000Z

64

Superconducting technology program: Sandia 1995 annual report  

SciTech Connect (OSTI)

Sandia`s STP program is a thallium-based high-temperature superconductor (HTS) research and development program consisting of efforts in powder synthesis and process development, open-system thick film conductor development, wire and tape fabrication, and HTS motor design. The objective of this work is to develop high-temperature superconducting conductors (wire and tape) capable of meeting requirements for high-power electrical devices of interest to industry. The research efforts currently underway are: (1) process development and characterization of thallium-based high-temperature superconducting closed system wire and tape; (2) investigation of the synthesis and processing of thallium-based thick films using two-zone processing; and (3) cryogenic design of a 30K superconducting motor. This report outlines the research that has been performed during FY95 in each of these areas.

Roth, E.P. [Sandia National Labs., Albuquerque, NM (United States). Superconductivity Materials and Technology Dept.

1996-03-01T23:59:59.000Z

65

Wire Making Techniques - HTS Coated Conductors - Fact Sheet  

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

Rolling Assisted Biaxially Textured Substrates (RABiTS Rolling Assisted Biaxially Textured Substrates (RABiTS TM ) coated conductors, characterized by their low cost and simple architecture, promise to meet industry price and performance targets. Introduction Since the discovery of high-temperature superconductors (HTS), notably YBa 2 Cu 3 O 7 (YBCO), researchers at the U.S. Department of Energy's (DOE) national laboratories have searched for ways to manufacture affordable flexible wires with high current density. One of the chief obstacles to the manufacture of commercial lengths of YBCO wire has been the phenomenon of weak links, which exist where current crosses a non-superconducting region such as a grain boundary. By aligning grains carefully, low angle boundaries between superconducting grains are assured, which

66

Power electronics performance in cryogenic environment: evaluation for use in HTS power devices  

Science Journals Connector (OSTI)

Power electronics (PE) plays a major role in electrical devices and systems, namely in electromechanical drives, in motor and generator controllers, and in power grids, including high-voltage DC (HVDC) power transmission. PE is also used in devices for the protection against grid disturbances, like voltage sags or power breakdowns. To cope with these disturbances, back-up energy storage devices are used, like uninterruptible power supplies (UPS) and flywheels. Some of these devices may use superconductivity. Commercial PE semiconductor devices (power diodes, power MOSFETs, IGBTs, power Darlington transistors and others) are rarely (or never) experimented for cryogenic temperatures, even when designed for military applications. This means that its integration with HTS power devices is usually done in the hot environment, raising several implementation restrictions. These reasons led to the natural desire of characterising PE under extreme conditions, e. g. at liquid nitrogen temperatures, for use in HTS devices. Some researchers expect that cryogenic temperatures may increase power electronics' performance when compared with room-temperature operation, namely reducing conduction losses and switching time. Also the overall system efficiency may increase due to improved properties of semiconductor materials at low temperatures, reduced losses, and removal of dissipation elements. In this work, steady state operation of commercial PE semiconductors and devices were investigated at liquid nitrogen and room temperatures. Performances in cryogenic and room temperatures are compared. Results help to decide which environment is to be used for different power HTS applications.

P Pereira; S Valtchev; J Pina; A Gonçalves; M Ventim Neves; A L Rodrigues

2008-01-01T23:59:59.000Z

67

Superconductivity for Electric Systems: 2008 Annual Peer Review Final  

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

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

68

Frustrated phase separation and high temperature superconductivity  

SciTech Connect (OSTI)

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

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

1992-09-01T23:59:59.000Z

69

Frustrated phase separation and high temperature superconductivity  

SciTech Connect (OSTI)

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

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

1992-01-01T23:59:59.000Z

70

Cost Effective Open Geometry HTS MRI System amended to BSCCO 2212 Wire for High Field Magnets  

SciTech Connect (OSTI)

The original goal of this Phase II Superconductivity Partnership Initiative project was to build and operate a prototype Magnetic Resonance Imaging (MRI) system using high temperature superconductor (HTS) coils wound from continuously processed dip-coated BSCCO 2212 tape conductor. Using dip-coated tape, the plan was for MRI magnet coils to be wound to fit an established commercial open geometry, 0.2 Tesla permanent magnet system. New electronics and imaging software for a prototype higher field superconducting system would have added significantly to the cost. However, the use of the 0.2 T platform would allow the technical feasibility and the cost issues for HTS systems to be fully established. Also it would establish the energy efficiency and savings of HTS open MRI compared with resistive and permanent magnet systems. The commercial goal was an open geometry HTS MRI running at 0.5 T and 20 K. This low field open magnet was using resistive normal metal conductor and its heat loss was rather high around 15 kolwatts. It was expected that an HTS magnet would dissipate around 1 watt, significantly reduce power consumption. The SPI team assembled to achieve this goal was led by Oxford Instruments, Superconducting Technology (OST), who developed the method of producing commercial dip coated tape. Superconductive Components Inc. (SCI), a leading US supplier of HTS powders, supported the conductor optimization through powder optimization, scaling, and cost reduction. Oxford Magnet Technology (OMT), a joint venture between Oxford Instruments and Siemens and the world’s leading supplier of MRI magnet systems, was involved to design and build the HTS MRI magnet and cryogenics. Siemens Magnetic Resonance Division, a leading developer and supplier of complete MRI imaging systems, was expected to integrate the final system and perform imaging trials. The original MRI demonstration project was ended in July 2004 by mutual consent of Oxford Instruments and Siemens. Between the project start and that date a substantial shift in the MRI marketplace occurred, with rapid growth for systems at higher fields (1.5 T and above) and a consequent decline in the low field market (<1.0 T). While the project aim appeared technically attainable at that time, the conclusion was reached that the system and market economics do not warrant additional investment. The program was redirected to develop BSCCO 2212 multifilament wire development for high field superconducting magnets for NMR and other scientific research upon an agreement between DOE and Oxford Instruments, Superconducting Technology. The work t took place between September, 2004 and the project end in early 2006 was focused on 2212 multifilamentary wire. This report summarizes the technical achievements both in 2212 dip coated for an HTS MRI system and in BSCCO 2212 multifilamentary wire for high field magnets.

Kennth Marken

2006-08-11T23:59:59.000Z

71

Large Superconducting Magnet Systems  

E-Print Network [OSTI]

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

Védrine, P

2014-01-01T23:59:59.000Z

72

Development of an HTS hydroelectric power generator for the hirschaid power station  

Science Journals Connector (OSTI)

This paper describes the development and manufacture of a 1.7MW, 5.25kV, 28pole, 214rpm hydroelectric power generator consisting of superconducting HTS field coils and a conventional stator. The generator is to be installed at a hydro power station in Hirschaid, Germany and is intended to be a technology demonstrator for the practical application of superconducting technology for sustainable and renewable power generation. The generator is intended to replace and uprate an existing conventional generator and will be connected directly to the German grid. The HTS field winding uses Bi-2223 tape conductor cooled to about 30K using high pressure helium gas which is transferred from static cryocoolers to the rotor via a bespoke rotating coupling. The coils are insulated with multi-layer insulation and positioned over laminated iron rotor poles which are at room temperature. The rotor is enclosed within a vacuum chamber and the complete assembly rotates at 214rpm. The challenges have been significant but have allowed Converteam to develop key technology building blocks which can be applied to future HTS related projects. The design challenges, electromagnetic, mechanical and thermal tests and results are presented and discussed together with applied solutions.

Ruben Fair; Clive Lewis; Joseph Eugene; Martin Ingles

2010-01-01T23:59:59.000Z

73

Design and testing of the HTS bearing for a 10 kWh flywheel system  

Science Journals Connector (OSTI)

Flywheels are of interest for a wide range of energy storage applications, from support of renewable resources to distributed power applications and uninterruptible power systems (UPS) (Day et al 2000 Proc. EESAT 2000 (Orlando, FL, Sept. 2000)). The use of high-temperature superconducting (HTS) bearings for such systems has significant advantages for applications requiring large amounts of energy to be stored with low parasitic losses and with minimal system maintenance. As flywheel systems increase in size, it becomes a significant challenge to provide adequate stiffness in these bearings without exceeding the strength limits of rotating magnet assemblies. The Boeing Company is designing and building a prototype flywheel of 10 kWh total stored energy and has focused much effort on the HTS bearing system. This paper will describe the general structure of the bearing and the steps taken to optimize its magnetic and structural performance and show recent test results.

A C Day; M Strasik; K E McCrary; P E Johnson; J W Gabrys; J R Schindler; R A Hawkins; D L Carlson; M D Higgins; J R Hull

2002-01-01T23:59:59.000Z

74

NEST Scientific Report 2007-2009 Quantum properties of hybrid and superconducting structures  

E-Print Network [OSTI]

high critical temperature superconductors (HTS), and in general in complex oxides, electrons self and macroscopic quantum properties in high critical temperature superconductor (HTS) junctions and nanostructures. The recent experiments on macroscopic quantum (MQ) effects in high critical temperature superconductor (HTS

Abbondandolo, Alberto

75

High temperature superconductivity: The products and their benefits  

SciTech Connect (OSTI)

Numerous qualitative studies have discussed, in detail, the benefits projected from the commercialization of HTS systems; however, few are available with quantitative predictions of market penetration and resultant benefits. This report attempts to quantify those benefits, as a function of time, by examining five key classes of candidate HTS electrical equipment, and projecting market entry and capture based on historical market entry o technologies considered analogous to HTS. Any such projection is a judgment, based on experience and available data, and the analyses in this report fall into that category. The five classes of equipment examined are electric motors, transformers, generators, underground cable, and fault current limiters. In each of these classes, major international programs are now underway to develop and commercialize HTS equipment in a time frame from the present to the year 2020. Based on technology status and perceived market advantages as determined from the references, market entry dates were projected followed by market penetration predictions. The earliest equipment to achieve commercialization is predicted to be fault current limiters, predicted for market entry in the 2003--2004 time period. Transformers and cable are projected for entry in 2005 followed by electric motors in 2006. The final market entry will be by generators, predicted for commercialization in 2011.

Lawrence, L.R. Jr.; Cox, C.; Broman, D. [Bob Lawrence and Associates, Inc., Alexandria, VA (United States)

1998-07-01T23:59:59.000Z

76

ORNL Publishes Study on Superconducting Wire Performance | Department of  

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

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

77

Method and etchant to join ag-clad BSSCO superconducting tape  

DOE Patents [OSTI]

A method of removing a silver cladding from high temperature superconducting material clad in silver (HTS) is disclosed. The silver clad HTS is contacted with an aqueous solution of HNO.sub.3 followed by an aqueous solution of NH.sub.4 OH and H.sub.2 O.sub.2 for a time sufficient to remove the silver cladding from the superconducting material without adversely affecting the superconducting properties of the superconducting material. A portion of the silver cladding may be masked with a material chemically impervious to HNO.sub.3 and to a combination of NH.sub.4 OH and H.sub.2 O.sub.2 to preserve the Ag coating. A silver clad superconductor is disclosed, made in accordance with the method discussed.

Balachandran, Uthamalingam (Hinsdale, IL); Iyer, Anand N. (Downers Grove, IL); Huang, Jiann Yuan (Hsinchu, TW)

1999-01-01T23:59:59.000Z

78

Method and etchant to join Ag-clad BSSCO superconducting tape  

DOE Patents [OSTI]

A method of removing a silver cladding from high temperature superconducting material clad in silver (HTS) is disclosed. The silver clad HTS is contacted with an aqueous solution of HNO{sub 3} followed by an aqueous solution of NH{sub 4}OH and H{sub 2}O{sub 2} for a time sufficient to remove the silver cladding from the superconducting material without adversely affecting the superconducting properties of the superconducting material. A portion of the silver cladding may be masked with a material chemically impervious to HNO{sub 3} and to a combination of NH{sub 4}OH and H{sub 2}O{sub 2} to preserve the Ag coating. A silver clad superconductor is disclosed, made in accordance with the method discussed. 3 figs.

Balachandran, U.; Iyer, A.N.; Huang, J.Y.

1999-03-16T23:59:59.000Z

79

Superconductivity program for electric systems, Superconductivity Technology Center, Los Alamos National Laboratory, annual progress report for fiscal year 1997  

SciTech Connect (OSTI)

Development of high-temperature superconductors (HTS) has undergone tremendous progress during the past year. Kilometer tape lengths and associated magnets based on BSCCO materials are now commercially available from several industrial partners. Superconducting properties in the exciting YBCO coated conductors continue to be improved over longer lengths. The Superconducting Partnership Initiative (SPI) projects to develop HTS fault current limiters and transmission cables have demonstrated that HTS prototype applications can be produced successfully with properties appropriate for commercial applications. Research and development activities at LANL related to the HTS program for Fiscal Year 1997 are collected in this report. LANL continues to support further development of Bi2223 and Bi2212 tapes in collaboration with American Superconductor Corporation (ASC) and Oxford Superconductivity Technology, Inc. (OSTI), respectively. The tape processing studies involving novel thermal treatments and microstructural characterization have assisted these companies in commercializing these materials. The research on second-generation YBCO-coated conductors produced by pulsed-laser deposition (PLD) over buffer template layers produced by ion beam-assisted deposition (IBAD) continues to lead the world. The applied physics studies of magnetic flux pinning by proton and heavy ion bombardment of BSCCO and YBCO tapes have provided many insights into improving the behavior of these materials in magnetic fields. Sections 4 to 7 of this report contain a list of 29 referred publications and 15 conference abstracts, a list of patent and license activities, and a comprehensive list of collaborative agreements in progress and completed.

Willis, J.O.; Newnam, B.E. [eds.; Peterson, D.E.

1999-03-01T23:59:59.000Z

80

{open_quotes}Local texture, current flow, and superconductive transport properties of Tl1223 deposits on practical substrates{close_quotes}  

SciTech Connect (OSTI)

Quantitative investigations of the crystal grain orientations and electrical transport properties of high temperature superconducting (HTS)TiBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 8+x} (Tl1223) deposits on polycrystalline substrates show that current flow comprises percolative networks of strongly-coupled material. Superconductive transport properties on different samples, on the same samples at different widths, and on samples with artificially-induced strong flux pinning defects confirm the nature of current flow, and suggest that these materials may be useful as a new class of HTS conductors.

Christen, D.K.; Specht, E.D.; Goyal, A. [and others

1996-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

Test results of two high temperature superconducting sample coils  

SciTech Connect (OSTI)

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

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

1993-10-01T23:59:59.000Z

82

Shock-induced synthesis of high temperature superconducting materials  

DOE Patents [OSTI]

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

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

1987-06-18T23:59:59.000Z

83

High-temperature superconducting magnet for use in saturated core FCL  

Science Journals Connector (OSTI)

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

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

2008-01-01T23:59:59.000Z

84

STATEMENT OF CONSIDERATIONS REQUEST BY DUPONT SUPERCONDUCTIVITY FOR AN ADVANCE  

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

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

85

Development of superconducting transmission cable. CRADA final report  

SciTech Connect (OSTI)

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

86

Development of 1 MW-class HTS motor for podded ship propulsion system  

Science Journals Connector (OSTI)

To reduce fuel consumption and lead to a major reduction of pollution from NOx, SOx and CO2, the electric ship propulsion system is one of the most prospective substitutes for conventional ship propulsion systems. In order to spread it, innovative technologies for the improvement of the power transmission are required. The high temperature superconducting technology has the possibility for a drastic reduction of power transmission loss. Recently, electric podded propulsions have become popular for large cruise vessels, icebreakers and chemical tankers because of the flexibility of the equipment arrangement and the stern hull design, and better maneuverability in harbour, etc. In this paper, a 1 MW-class High temperature superconducting (HTS) motor with high efficiency, smaller size and simple structure, which is designed and manufactured for podded propulsion, is reported. For the case of a coastal ship driven by the optimized podded propulsion in which the 1MW HTS motor is equipped, the reductions of fluid dynamic resistance and power transmission losses are demonstrated. The present research & development has been supported by the New Energy and Industrial Technology Development Organization (NEDO).

K Umemoto; K Aizawa; M Yokoyama; K Yoshikawa; Y Kimura; M Izumi; K Ohashi; M Numano; K Okumura; M Yamaguchi; Y Gocho; E Kosuge

2010-01-01T23:59:59.000Z

87

A stability verification technique using acoustic emission for an HTS monofilar component  

Science Journals Connector (OSTI)

This paper reports an acoustic emission (AE) technique that was developed for detecting the quenching and stability characteristics of high-temperature superconductors (HTSs), particularly a BSCCO-2212 monofilar component for a resistive superconducting fault current limiter (SFCL) system. The 24 kV class SFCL, which was recently developed by the KEPRI-LSIS collaboration group in Korea, requires almost 150 BSCCO-2212 monofilar components. A BSCCO-2212 monofilar HTS undergoes thermal and mechanical stress creating microcracks during and after quenching or reaching a fault state such as during a short-circuit test. The AE technique is a useful tool for detecting the presence of transient heating and the existence of hot spots within the superconducting fault current component.

H M Kim; K B Park; B W Lee; I S Oh; J W Sim; O B Hyun; Y Iwasa; H G Lee

2007-01-01T23:59:59.000Z

88

HTS component development for electric power applications  

SciTech Connect (OSTI)

This presentation covers the collaboration between Intermagnetics General Corporation (IGC) and U.S. DOE laboratories such as the Argonnne National Lab, Oak Ridge National Lab, and the DOE/Superconductivity Partnership Initiative (DOE/SPI); along with informal collaboration with six other government research facilities. Being developed is applications for superconductors related to electric power, such as generators, motors, transmisssion cable, fault current limiter, and transformers. Highlighted are the critical current densities of short and long tapes at 77K; material and labor costs for Bi-2223 tapes; structural and performance specifications for a HTS magnet; and an overview of the the DOE/SPI program with plans for future work.

Haldar, P.

1994-07-29T23:59:59.000Z

89

A High Temperature Superconductor (HTSC) Hot Electron (HE) THz Heterodyne Thermal Sensor (HTS): Computational Analysis of Conversion Gain in  

Science Journals Connector (OSTI)

The solution of the two temperature (electron and phonon) heat transfer equations, for nonequilibrium elctron–phonon cooling processes happening between electrons, sensor lattice, and the substrate system, is ...

M. M. Kaila

2002-06-01T23:59:59.000Z

90

Application of high temperature superconductors for fusion  

Science Journals Connector (OSTI)

The use of High Temperature Superconductor (HTS) materials in future fusion machines can increase the efficiency drastically. For ITER, W7-X and JT-60SA the economic benefit of HTS current leads was recognized after a 70 kA HTS current lead demonstrator was designed, fabricated and successfully tested by Karlsruhe Institute of Technology (KIT, which is a merge of former Forschungszentrum Karlsruhe and University of Karlsruhe). For ITER, the Chinese Domestic Agency will provide the current leads as a part of the superconducting feeder system. KIT is in charge of design, construction and test of HTS current leads for W7-X and JT-60SA. For W7-X 14 current leads with a maximum current of 18.2 kA are required that are oriented with the room temperature end at the bottom. JT60-SA will need 26 current leads (20 leads @ 20 kA and 6 leads @ 25.7 kA) which are mounted in vertical, normal position. These current leads are based on BiSCCO HTS superconductors, demonstrating that HTS material is now state of the art for highly efficient current leads. With respect to future fusion reactors, it would be very promising to use HTS material not only in current leads but also in coils. This would allow a large increase of efficiency if the coils could be operated at temperatures ?65 K. With such a high temperature it would be possible to omit the radiation shield of the coils, resulting in a less complex cryostat and a size reduction of the machine. In addition less refrigeration power is needed saving investment and operating costs. However, to come to an HTS fusion coil it is necessary to develop low ac loss HTS cables for currents well above 20 kA at high fields well above 10 T. The high field rules BiSCCO superconductors out at temperatures above 50 K, but RE-123 superconductors are promising. The development of a high current, high field RE-123 HTS fusion cable will not be targeted outside fusion community and has to be in the frame of a long term development programme for DEMO. KIT has already demonstrated a scalable concept using RE-123 HTS tapes that are assembled to Roebel type conductors. This concept can be expanded to form Rutherford cables as starting point for a development of a high current fusion cable. The status and prospect of using HTS conductors for fusion is discussed.

W.H. Fietz; R. Heller; S.I. Schlachter; W. Goldacker

2011-01-01T23:59:59.000Z

91

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

Office of Science (SC) Website

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

92

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

E-Print Network [OSTI]

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

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

2001-01-01T23:59:59.000Z

93

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

SciTech Connect (OSTI)

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

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

2005-09-01T23:59:59.000Z

94

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

Science Journals Connector (OSTI)

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

Krzysztof Byczuk and Jozef Spa?ek

1996-01-01T23:59:59.000Z

95

Superconducting fault current limiter for power utility application  

SciTech Connect (OSTI)

Recent accomplishments in the development of superconducting fault current limiters for power systems are outlined. These accomplishments include the comprehensive requirement for fault current limiters developed by SCE; down-selection; bridge concepts; shunt concepts; and high resistivity matrix substrates for HTS conductors. The proposed Phase II SPI-FCL Program is outlined. It is concluded that the SPI fault current limiter program will benefit both the power utility industry as well as the high temperature superconductivity community and progress of Phase I is right on target.

Leung, E. [Martin Marietta Corp., Oak Ridge, TN (United States)

1994-07-29T23:59:59.000Z

96

Automatic HTS force measurement instrument  

DOE Patents [OSTI]

A device is disclosed for measuring the levitation force of a high temperature superconductor sample with respect to a reference magnet includes a receptacle for holding several high temperature superconductor samples each cooled to superconducting temperature. A rotatable carousel successively locates a selected one of the high temperature superconductor samples in registry with the reference magnet. Mechanism varies the distance between one of the high temperature superconductor samples and the reference magnet, and a sensor measures levitation force of the sample as a function of the distance between the reference magnet and the sample. A method is also disclosed. 3 figs.

Sanders, S.T.; Niemann, R.C.

1999-03-30T23:59:59.000Z

97

Automatic HTS force measurement instrument  

DOE Patents [OSTI]

A device for measuring the levitation force of a high temperature superconductor sample with respect to a reference magnet includes a receptacle for holding several high temperature superconductor samples each cooled to superconducting temperature. A rotatable carousel successively locates a selected one of the high temperature superconductor samples in registry with the reference magnet. Mechanism varies the distance between one of the high temperature superconductor samples and the reference magnet, and a sensor measures levitation force of the sample as a function of the distance between the reference magnet and the sample. A method is also disclosed.

Sanders, Scott T. (Valparaiso, IN); Niemann, Ralph C. (Downers Grove, IL)

1999-01-01T23:59:59.000Z

98

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

E-Print Network [OSTI]

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

Mai, Rocky D. (Rocky Dikang)

2006-01-01T23:59:59.000Z

99

TEST RESULTS OF HTS COILS AND AN R AND D MAGNET FOR RIA.  

SciTech Connect (OSTI)

This paper presents the successful construction and test results of a magnetic mirror model for the Rare Isotope Accelerator (RIA) that is based on High Temperature Superconductors (HTS). In addition, the performance of thirteen coils (each made with {approx}220 meters of commercially available HTS tape) is also presented. The proposed HTS magnet is a crucial part of the R&D for the Fragment Separator region where the magnets are subjected to several orders of magnitude more radiation and energy deposition than typical beam line and accelerator magnets receive during their entire lifetime. A preliminary design of an HTS dipole magnet for the Fragment Separator region is also presented.

GUPTA, R.; ANERELLA, M.; HARRISON, M.; SCHMALZLE, J.; SAMPSON, W.; ZELLER, A.

2005-05-16T23:59:59.000Z

100

SciTech Connect: "high temperature superconductivity"  

Office of Scientific and Technical Information (OSTI)

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

Note: This page contains sample records for the topic "temperature superconducting hts" 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

Triaxial HTS Cable for the AEP Bixby Project  

SciTech Connect (OSTI)

Ultera has installed a single 200-meter long high temperature superconducting (HTS) 3-phase triaxial design cable at the American Electric Power (AEP) Bixby substation in Columbus, Ohio. The cable connects a 132/13.8 kV transformer to the distribution switchgear serving seven outgoing circuits. It was designed to carry 3000 Arms. Testing of 3- to 5-meter length prototype cables, including a 5-meter prototype with full scale terminations tested at ORNL was conducted prior to the manufacture and installation of the AEP triaxial cable. These prototypes were used to demonstrate the crucial operating conditions including steady state operation at the 3000 Arms design current, high voltage operation, high voltage withstand and 110 kV impulse, and overcurrent fault capability. A summary of the results from the thermal analysis and testing conducted by Ultera and ORNL will be presented. Some analysis of the cable thermal-hydraulic response based on the testing that were used to determine some of the cable cryogenic system requirements are also presented.

Demko, Jonathan A [ORNL; Gouge, Michael J [ORNL; Lindsay, David T [ORNL; Roden, Mark L [ORNL; Tolbert, Jerry Carlton [ORNL

2007-01-01T23:59:59.000Z

102

Microsoft Word - ASC2010-hts-after-review-v1.doc  

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

3 1 3 1  Abstract-This paper presents the goal and status of the high field High Temperature Superconductor (HTS) solenoid program funded through a series of SBIRs. The target of this R&D program is to build HTS coils that are capable of producing fields greater than 20 T when tested alone and approaching 40 T when tested in a background field magnet. The solenoid will be made with second generation (2G) high engineering current density HTS tape. To date, 17 HTS pancake coils have been built and tested in the temperature range from 20 K to 80 K. Quench protection, high stresses and minimization of degradation of conductor are some of the major challenges associated with this program. Index Terms-High Temperature Superconductors, HTS,

103

HTS power leads for the BTEV interaction region  

SciTech Connect (OSTI)

A new Interaction Region (IR) for the BTEV experiment was planned to be built at Fermilab. This IR would have required new superconducting quadrupole magnets and many additional power circuits for their operation. The new ''low beta'' quadrupole magnet design was based upon the Fermilab LHC quadrupole design, and would have operated at 9.56 kA in 4.5 K liquid helium. The use of conventional power leads for these circuits would have required substantially more helium for cooling than is available from the cryogenic plant, which is already operating close to its limit. To decrease the heat load and helium cooling demands, the use of HTS power leads was necessary. In developing specifications for HTS leads for the BTEV interaction region, several 6 kA HTS leads produced by American Superconductor Corporation (ASC) have been tested at over-current conditions. Final design requirements were to be based on these test results. This paper summarizes the test results and describes the design requirements for the 9.65 kA HTS power leads.

Feher, S.; Carcagno, R.; Orris, D.; Page, T.; Pischalnikov, Y.; Rabehl, R.; Sylvester, C.; Tartaglia, M.; Tompkins, J.C.; /Fermilab

2005-05-01T23:59:59.000Z

104

The Progress on Low-Cost, High-Quality, High-Temperature Superconducting Tapes Deposited by the Combustion Chemical Vapor Deposition Process  

SciTech Connect (OSTI)

The innovative Combustion Chemical Vapor Deposition (CCVD) process is a non-vacuum technique that is being investigated to enable next generation products in several application areas including high-temperature superconductors (HTS). In combination with the Rolling Assisted Biaxially Textured Substrate (RABiTS) technology, the CCVD process has significant promise to provide low-cost, high-quality lengths of YBCO coated conductor. Over 100 meter lengths of both Ni and Ni-W (3 at. Wt.%) substrates with a surface roughness of 12-18 nm were produced. The CCVD technology has been used to deposit both buffer layer coatings as well as YBCO superconducting layers. Buffer layer architecture of strontium titanate (SrTiO{sub 3}) and ceria (CeO{sub 2}) have been deposited by CCVD on textured nickel substrates and optimized to appropriate thicknesses and microstructures to provide templates for growing PLD YBCO with a J{sub c} of 1.1 MA/cm{sup 2} at 77 K and self-field. The CCVD buffer layers have been scaled to meter plus lengths with good epitaxial uniformity along the length. A short sample cut from one of the lengths enabled high critical current density PLD YBCO. Films of CCVD YBCO superconductors have been grown on single crystal substrates with critical current densities over 1 MA/cm{sup 2}. In addition, superconducting YBCO films with an I{sub c} of 60 A/cm-width (J{sub c} = 1.5 MA/cm{sup 2}) were grown on ORNL RABiTS (CeO{sub 2}/YSZ/Y{sub 2}O{sub 3}/Ni/Ni-3W) using CCVD process.

Shoup, S.S.; White, M.K.; Krebs, S.L.; Darnell, N.; King, A.C.; Mattox, D.S.; Campbell, I.H.; Marken, K.R.; Hong, S.; Czabaj, B.; Paranthaman, M.; Christen, H.M.; Zhai, H.-Y. Specht, E.

2008-06-24T23:59:59.000Z

105

Development of Strengthened Bundle High Temperature Superconductors  

SciTech Connect (OSTI)

In the process of developing high temperature superconducting (HTS) transmission cables, it was found that mechanical strength of the superconducting tape is the most crucial property that needs to be improved. It is also desirable to increase the current carrying capacity of the conductor so that fewer layers are needed to make the kilo-amp class cables required for electric utility usage. A process has been developed by encapsulating a stack of Bi-2223/Ag tapes with a silver or non-silver sheath to form a strengthened bundle superconductor. This process was applied to HTS tapes made by the Continuous Tube Forming and Filling (CTFF) technique pursued by Plastronic Inc. and HTS tapes obtained from other manufacturers. Conductors with a bundle of 2 to 6 HTS tapes have been made. The bundled conductor is greatly strengthened by the non-silver sheath. No superconductor degradation as compared to the sum of the original critical currents of the individual tapes was seen on the finished conductors.

Lue, J.W.; Lubell, M.S. [Oak Ridge National Lab., TN (United States); Demko, J.A. [Oak Ridge Inst. for Science and Education, TN (United States); Tomsic, M. [Plastronic, Inc., Troy, OH (United States); Sinha, U. [Southwire Company, Carollton, GA (United States)

1997-12-31T23:59:59.000Z

106

Design and Development of a 100 MVA HTS Generator for Commercial Entry  

SciTech Connect (OSTI)

In 2002, General Electric and the US Department of Energy (DOE) entered into a cooperative agreement for the development of a commercialized 100 MVA generator using high temperature superconductors (HTS) in the field winding. The intent of the program was to: (1) identify and develop technologies that would be needed for such a generator; (2) develop conceptual designs for generators with ratings of 100 MVA and higher using HTS technology; (3) perform proof of concept tests at the 1.5 MW level for GE's proprietary warm iron rotor HTS generator concept; and (4) design, build, and test a prototype of a commercially viable 100 MVA generator that could be placed on the power grid. This report summarizes work performed during the program and is provided as one of the final program deliverables. The design for the HTS generator was based on GE's warm iron rotor concept in which a cold HTS coil is wound around a warm magnetic iron pole. This approach for rotating HTS electrical machinery provides the efficiency benefits of the HTS technology while addressing the two most important considerations for power generators in utility applications: cost and reliability. The warm iron rotor concept uses the least amount of expensive HTS wire compared to competing concepts and builds on the very high reliability of conventional iron core stators and armature windings.

None

2007-06-07T23:59:59.000Z

107

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

E-Print Network [OSTI]

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

Tian De Cao

2007-06-01T23:59:59.000Z

108

Low temperature specific heat of superconducting ternary intermetallics  

Science Journals Connector (OSTI)

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

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

2008-01-01T23:59:59.000Z

109

Development of high temperature superconductors for magnetic field applications  

SciTech Connect (OSTI)

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

Larbalestier, D.C.

1991-01-01T23:59:59.000Z

110

Development of high temperature superconductors for magnetic field applications  

SciTech Connect (OSTI)

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

Larbalestier, D.C.

1991-12-31T23:59:59.000Z

111

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

E-Print Network [OSTI]

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

Allen, Roland E.

1975-01-01T23:59:59.000Z

112

Structure for hts composite conductors and the manufacture of same  

DOE Patents [OSTI]

A superconducting oxide composite structure including a superconducting oxide member, a metal layer surrounding the superconducting oxide member, and an insulating layer of a complex oxide formed in situ adjacent to the superconducting oxide member and the metal layer is provided together with a method of forming such a superconducting oxide composite structure including encapsulating a superconducting oxide member or precursor within a metal matrix layer from the group of: (i) a reactive metal sheath adjacent to the superconducting oxide member or precursor, the reactive metal sheath surrounded by a second metal layer or (ii) an alloy containing a reactive metal; to form an intermediate product, and, heating the intermediate product at temperatures and for time sufficient to form an insulating layer of a complex oxide in situ, the insulating layer to the superconducting oxide member or precursor and the metal matrix layer.

Cotton, James D. (Seattle, WA); Riley, Jr., Gilbert Neal (Marlborough, MA)

1999-01-01T23:59:59.000Z

113

Structure for HTS composite conductors and the manufacture of same  

DOE Patents [OSTI]

A superconducting oxide composite structure including a superconducting oxide member, a metal layer surrounding the superconducting oxide member, and an insulating layer of a complex oxide formed in situ adjacent to the superconducting oxide member and the metal layer is provided together with a method of forming such a superconducting oxide composite structure including encapsulating a superconducting oxide member or precursor within a metal matrix layer from the group of: (1) a reactive metal sheath adjacent to the superconducting oxide member or precursor, the reactive metal sheath surrounded by a second metal layer or (2) an alloy containing a reactive metal; to form an intermediate product, and, heating the intermediate product at temperatures and for time sufficient to form an insulating layer of a complex oxide in situ, the insulating layer to the superconducting oxide member or precursor and the metal matrix layer. 10 figs.

Cotton, J.D.; Riley, G.N. Jr.

1999-06-01T23:59:59.000Z

114

Field Demonstration of a 24-kV Superconducting Cable at Detroit Edison  

SciTech Connect (OSTI)

Customer acceptance of high temperature superconducting (HTS) cable technology requires a substantial field demonstration illustrating both the system's technical capabilities and its suitability for installation and operation within the utility environment. In this project, the world's first underground installation of an HTS cable using existing ductwork, a 120 meter demonstration cable circuit was designed and installed between the 24 kV bus distribution bus and a 120 kV-24 kV transformer at Detroit Edison's Frisbie substation. The system incorporated cables, accessories, a refrigeration system, and control instrumentation. Although the system was never put in operation because of problems with leaks in the cryostat, the project significantly advanced the state-of-the-art in the design and implementation of Warm Dielectric cable systems in substation applications. Lessons learned in this project are already being incorporated in several ongoing demonstration projects.

Kelley, Nathan; Corsaro, Pietro

2004-12-01T23:59:59.000Z

115

Flywheel energy storage using superconducting magnetic bearings  

SciTech Connect (OSTI)

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

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

1994-04-01T23:59:59.000Z

116

High Field Magnet R&D |Superconducting Magnet Division  

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

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

117

Superconducting magnetic Wollaston prism for neutron spin encoding  

SciTech Connect (OSTI)

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

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

2014-05-15T23:59:59.000Z

118

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

SciTech Connect (OSTI)

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

Yung Moo Huh

2001-05-01T23:59:59.000Z

119

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

SciTech Connect (OSTI)

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

Douglas K. Finnemore

2001-06-25T23:59:59.000Z

120

Restoration and testing of an HTS fault current controller  

SciTech Connect (OSTI)

A three-phase, 1200 A, 12.5 kV fault current controller using three HTS 4 mH coils, was built by industry and tested in 1999 at the Center Substation of Southern California Edison in Norwalk, CA. During the testing, it appeared that each of the three single-phase units had experienced a voltage breakdown, one externally and two internally. Los Alamos National Laboratory (LANL) was asked by DOE to restore the operation of the fault current controller provided the HTS coils had not been damaged during the initial substation tests. When the internally-failed coil vacuum vessels were opened it became evident that in these two vessels, a flashover had occurred at the high voltage bus section leading to the terminals of the superconducting coil. An investigation into the failure mechanism resulted in six possible causes for the flashover. Based on these causes, the high voltage bus was completely redesigned. Single-phase tests were successfully performed on the modified unit at a 13.7 kV LANL substation. This paper presents the postulated voltage flashover failure mechanisms, the new high voltage bus design which mitigates the failure mechanisms, the sequence of tests used to validate the new design, and finally, the results of variable load and short-circuit tests with the single-phase unit operating on the LANL 13.7 kV substation.

Waynert, J. A. (Joseph A.); Boenig, H. (Heinrich E.); Mielke, C. H. (Charles H.); Willis, J. O. (Jeffrey O.); Burley, B. L. (Burt L.)

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

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

E-Print Network [OSTI]

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

Baiej, Hanan Tahir

2013-01-01T23:59:59.000Z

122

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

E-Print Network [OSTI]

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

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

2014-01-01T23:59:59.000Z

123

Superconducting Magnet Division  

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

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

124

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

SciTech Connect (OSTI)

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

Norman, M. R.; Materials Science Division

2010-01-01T23:59:59.000Z

125

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

SciTech Connect (OSTI)

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

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

2010-10-01T23:59:59.000Z

126

A Conceptual Design of Superconducting Fault Current Limiter with Bi2223 in 6.6 kV Distribution System  

Science Journals Connector (OSTI)

We have proposed a new type fault current limiter, which consists of a flux-lock reactor...c...superconducting (HTS) element and ac magnetic field coil (Flux-Lock Type Fault Current Limiter: FLT-FCL). This paper ...

Yu-Hong Guo; Toshiyuki Uchii; Yasunobu Yokomizu…

1998-01-01T23:59:59.000Z

127

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

E-Print Network [OSTI]

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

Boyer, Michael Christopher

2008-01-01T23:59:59.000Z

128

Superconducting materials for large scale applications  

SciTech Connect (OSTI)

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

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

2004-05-06T23:59:59.000Z

129

An overview of Boeing flywheel energy storage systems with high-temperature  

Science Journals Connector (OSTI)

An overview summary of recent Boeing work on high-temperature superconducting (HTS) bearings is presented. A design is presented for a small flywheel energy storage system that is deployable in a field installation. The flywheel is suspended by a HTS bearing whose stator is conduction cooled by connection to a cryocooler. At full speed, the flywheel has 5 kW h of kinetic energy, and it can deliver 3 kW of three-phase 208 V power to an electrical load. The entire system, which includes a containment structure, is compatible with transportation by forklift or crane. Laboratory measurements of the bearing loss are combined with the parasitic loads to estimate the efficiency of the system. Improvements in structural composites are expected to enable the operation of flywheels with very high rim velocities. Small versions of such flywheels will be capable of very high rotational rates and will likely require the low loss inherent in HTS bearings to achieve these speeds. We present results of experiments with small-diameter rotors that use HTS bearings for levitation and rotate in vacuum at kHz rates. Bearing losses are presented as a function of rotor speed.

M Strasik; J R Hull; J A Mittleider; J F Gonder; P E Johnson; K E McCrary; C R McIver

2010-01-01T23:59:59.000Z

130

From Ions to Wires to the Grid: The Transformational Science of LANL Research in High-Tc Superconducting Tapes and Electric Power Applications  

SciTech Connect (OSTI)

The Department of Energy (DOE) Office of Electricity Delivery and Energy Reliability (OE) has been tasked to lead national efforts to modernize the electric grid, enhance security and reliability of the energy infrastructure, and facilitate recovery from disruptions to energy supplies. LANL has pioneered the development of coated conductors – high-temperature superconducting (HTS) tapes – which permit dramatically greater current densities than conventional copper cable, and enable new technologies to secure the national electric grid. Sustained world-class research from concept, demonstration, transfer, and ongoing industrial support has moved this idea from the laboratory to the commercial marketplace.

Ken Marken

2009-05-20T23:59:59.000Z

131

From Ions to Wires to the Grid: The Transformational Science of LANL Research in High-Tc Superconducting Tapes and Electric Power Applications  

ScienceCinema (OSTI)

The Department of Energy (DOE) Office of Electricity Delivery and Energy Reliability (OE) has been tasked to lead national efforts to modernize the electric grid, enhance security and reliability of the energy infrastructure, and facilitate recovery from disruptions to energy supplies. LANL has pioneered the development of coated conductors ? high-temperature superconducting (HTS) tapes ? which permit dramatically greater current densities than conventional copper cable, and enable new technologies to secure the national electric grid. Sustained world-class research from concept, demonstration, transfer, and ongoing industrial support has moved this idea from the laboratory to the commercial marketplace.

Ken Marken

2010-01-08T23:59:59.000Z

132

NEW DESIGN OF NEON REFRIGERATOR FOR HTS POWER MACHINES  

Science Journals Connector (OSTI)

In 2007 we developed a prototype refrigerator with a small turbo?expander to provide adequate cooling power (2 kW at 70 K) for HTS (High Temperature Superconductor) power machines. The reverse?Brayton cycle with neon gas as a working fluid was adopted in the refrigerator. The prototype refrigerator does not have enough COP (Coefficient of Performance) for practical HTS applications and the purpose of this study is to research the information required for designing a new neon refrigerator with improved performance. We take the same refrigeration cycle and working fluid as the prototype one adopted but a lower process pressure of 1 MPa/0.5 MPa is chosen instead of 2 MPa/1 MPa. The lower process pressure is required by the turbo?compressor design and the refrigeration process is analyzed by using a newly developed process simulator. Also a heat?exchanger configuration is studied to make the refrigerator size small. The new refrigerator will have a cooling power of 2.5 kW at 65 K and a COP of 0.06 at 80 K.

S. Yoshida; H. Hirai; A. Takaike; M. Hirokawa; Y. Aizawa; Y. Kamioka; H. Okamoto; H. Hayashi; Y. Shiohara

2010-01-01T23:59:59.000Z

133

Epitaxial HTS bolometers on silicon for IR detection  

SciTech Connect (OSTI)

Silicon wafers have shown promise for the fabrication of photothermal IR detectors (i.e., bolometers) from epitaxial HTS thin films of YBa{sub 2}Cu{sub 3}O{sub (7{minus}{delta})} (YBCO). Conventional IC-grade wafers, ultrathin wafers, and micromachined-silicon membrane windows in conventional wafers, are all suitable, but the latter provides considerable advantage for bolometer performance. The high thermal conductivity and strength of silicon make it ideal for submicron-thick window designs. Epitaxy in the HTS film is advantageous, since it reduces granular disorder, the primary cause of dark noise (resistance-fluctuations) in the detector. Mid-to-far-IR transparency of Si at 90 K is unique among those substrates that support high-quality epitaxial YBCO films. This Si transparency to IR can be used for various improvements in the optical design of these devices. The authors review the thermal and optical advantages of silicon substrates, device fabrication issues, and bolometer modeling. Thermal modeling of membrane bolometers indicates that the steady-state temperature-rise profile is nonuniform, but that this does not degrade the response linearity of the bolometer. Certain size limits and trade-offs in the design, will be important in the final device performance. They also discuss applications to FTIR instruments, and extensions of this technology to arrays including a novel on-chip transform spectrometer design.

Fenner, D.B.; Li, Q.; Hamblen, W.D.; Luo, J.; Hamblen, D.G. [AFR, Inc., East Hartford, CT (United States). Superconductivity Group; Budnick, J.I. [Univ. of Connecticut, Storrs, CT (United States). Dept. of Physics

1994-12-31T23:59:59.000Z

134

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

E-Print Network [OSTI]

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

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

2011-11-02T23:59:59.000Z

135

Department of Energy`s Wire Development Workshop - Superconductivity program for electric systems  

SciTech Connect (OSTI)

The 1996 High-Temperature Superconducting Wire Development Workshop was held on January 31--February 1 at the Crown Plaza Tampa Westshore in Tampa, Florida. The meeting was hosted by Tampa Electric Company and sponsored by the Department of Energy`s Superconductivity Program for Electric Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. Tampa Electric`s Greg Ramon began the meeting by giving a perspective on the changes now occurring in the utility sector. Major program wire development accomplishments during the past year were then highlighted, particularly the world record achievements at Los Alamos and Oak Ridge National Laboratories. The meeting then focussed on three priority technical issues: thallium conductors; AC losses in HTS conductors; and coated conductors on textured substrates. Following in-depth presentations, working groups were formed in each technology area to discuss and critique the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

NONE

1996-06-01T23:59:59.000Z

136

TEST RESULTS OF HTS COILS AND AN R&D MAGNET FOR RIA* , M. Anerella, M. Harrison, J. Schmalzle, W. Sampson, BNL, UPTON, NY, 11973 U.S.A.  

E-Print Network [OSTI]

TEST RESULTS OF HTS COILS AND AN R&D MAGNET FOR RIA* R. Gupta# , M. Anerella, M. Harrison, J This paper presents the successful construction and test results of a magnetic mirror model for the Rare Isotope Accelerator (RIA) that is based on High Temperature Superconductors (HTS). In addition

Gupta, Ramesh

137

STATEMENT OF CONSIDERATIONS REQUEST BY IGC-SUPERPOWER, LLC, FOR...  

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

entitled "510 MVA High Temperature Superconducting (Hereinafter "HTS) Power Transformer," pertains to the development of an advanced HTS 510 MVA alpha prototype...

138

High Voltage Testing of a 5-meter Prototype Triaxial HTS Cable  

SciTech Connect (OSTI)

High voltage tests were performed on a 5-m long prototype triaxial HTS cable (supplied by Ultera) at ORNL in preparation for installation of a 200-m HTS cable of the same design at the AEP utility substation in Columbus, Ohio. The triaxial design comprises three concentric phases and shield around a common former with the phase to phase dielectric at cryogenic temperature. Advantages of this design include increased current density, a reduced amount of HTS tape needed, and reduced heat load. The phase to phase voltage will be 13.2 kVrms (7.6 kVrms to ground). Preliminary testing was done on half-scale and full-scale terminations which successfully passed AC withstand, partial discharge, and impulse tests. High voltage tests conducted on the 5-m cable with the cable straight and after bending 90 degrees were ac withstand to 39 kVrms, partial discharge inception, and a minimum of 10 positive and 10 negative lightning waveform impulses at 110 kV. Phase to phase insulation was tested by applying high voltage to each phase one at a time with all the other phases grounded. Partial discharge data will be presented. The 5-m prototype triaxial HTS cable passed all the HV tests performed, with a PD inception voltage significantly above the required voltage.

Sauers, Isidor [ORNL; James, David Randy [ORNL; Ellis, Alvin R [ORNL; Tuncer, Enis [ORNL; Pace, Marshall O [ORNL; Gouge, Michael J [ORNL; Demko, Jonathan A [ORNL; Lindsay, David T [ORNL

2007-01-01T23:59:59.000Z

139

Resistive fault current limiter using HTS single-layer coils  

Science Journals Connector (OSTI)

This paper presents the work that is being done as a part of the project to develop a resistive current limiter using HTS Bi-2223/Ag tapes with the same construction scheme previously reported using LTS NbTi/CuNi wire with normal operating current of 170 A in liquid helium bath. The Bi–2223/Ag tape was helically wounded on several cylindrical G-10 tubes forming concentric coils connected in series, parallel or anti-parallel configurations in order to reduce the equivalent inductance of the complete winding. The design targets are the impedance of the electromagnetic system rising to 1.5 ? during a fault occurrence in absence of inductance both in the normal state and in the superconducting state, rated voltage and current of 15 kV and 400 A, respectively, with maximum flux density of 0.1 T. The test results in low voltage (AC/DC) as well as magnetic field measurements at 77 K and 4.2 K are presented and the limiting performance of the system are also discussed.

Carlos A. Baldan; Carlos Y. Shigue; Daltro G. Pinatti; Ernesto Ruppert-Filho; Rafael C. Freitas; Roberto P. Homrich

2004-01-01T23:59:59.000Z

140

Potential impact of high temperature superconductors on maglev transportation  

SciTech Connect (OSTI)

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

Hull, J.R.

1992-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

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

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

142

HTS dc bias coil for 35 kV/90 MVA saturated iron-core fault current limiter  

Science Journals Connector (OSTI)

A superconductive coil with 141,000 ampere-turns designed magnetizing power, made of 17,600 meters of BSCCO 2223 HTS tapes, was fabricated and tested. This coil was built for a 35 kV/90 MVA saturated iron-core fault current limiter. Computer simulations on the performance of the coil were carried out using ANSYS. The critical current of the superconducting coil and the dc resistance of the coil, including the non-superconducting joints, were investigated. Spatial distribution of the magnetic field was measured and compared with the simulation results. In this paper, we will report the configuration and the key parameters of the coil as well as the experimental and simulation results.

W.Z. Gong; J.Y. Zhang; Z.J. Cao; H. Hong; B. Tian; Y. Wang; J.Z. Wang; X.Y. Niu; J. Qiu; S.H. Wang; Y. Xin

2008-01-01T23:59:59.000Z

143

Method of forming an HTS article  

DOE Patents [OSTI]

A method of forming a superconducting article includes providing a substrate tape, forming a superconducting layer overlying the substrate tape, and depositing a capping layer overlying the superconducting layer. The capping layer includes a noble metal and has a thickness not greater than about 1.0 micron. The method further includes electrodepositing a stabilizer layer overlying the capping layer using a solution that is non-reactive to the superconducting layer. The superconducting layer has an as-formed critical current I.sub.C(AF) and a post-stabilized critical current I.sub.C(PS). The I.sub.C(PS) is at least about 95% of the I.sub.C(AF).

Bhattacharya, Raghu N.; Zhang, Xun; Selvamanickam, Venkat

2014-08-19T23:59:59.000Z

144

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

E-Print Network [OSTI]

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

Johansen, Tom Henning

145

Superconducting Magnet Division | Brookhaven National Laboratory  

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

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

146

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

SciTech Connect (OSTI)

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

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

2008-01-01T23:59:59.000Z

147

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

148

Superconducting active impedance converter  

DOE Patents [OSTI]

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

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

1993-01-01T23:59:59.000Z

149

Design and Development of the First Polish Superconducting Fault Current Limiter For MV Distribution Systems  

Science Journals Connector (OSTI)

Superconducting fault current limiters (SFCL) are designed to protect the electrical grid from faults. The rapid increase of impedance of the SFCL reduces the short current in the circuit. In this paper, we present the design and development of coreless inductive SFCL for MV distribution systems. It is a very attractive design which reduces the weight of the device thanks to the coreless construction and the size of primary winding, reduced thanks to cryogenic cooling. The primary 2G HTS and secondary 2G HTS windings are magnetically coupled to one another. Copper primary winding connected parallely to the HTS primary winding is magnetically coupled to HTS windings and ensure that in cases of lack of cooling or superconductor failure, the protected circuit will not be disrupted. Tests performed at high power test facility shows the limiting performance of the coreless inductive SFCL.

Janusz Kozak; Michal Majka; Tadeusz Janowski; Slawomir Kozak

2012-01-01T23:59:59.000Z

150

High-temperature superconductivity in a family of iron pnictide materials  

E-Print Network [OSTI]

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

Gillett, Jack

2011-11-08T23:59:59.000Z

151

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

E-Print Network [OSTI]

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

1991-01-01T23:59:59.000Z

152

Cryogenic experiences during W7-X HTS-current lead tests  

SciTech Connect (OSTI)

The Karlsruhe Institute of Technology (KIT) was responsible for design, production and test of the High Temperature Superconductor (HTS) current leads (CL) for the stellerator Wendelstein 7-X (W7-X). 16 current leads were delivered. Detailed prototype tests as well as the final acceptance tests were performed at KIT, using a dedicated test cryostat assembled beside and connected to the main vacuum vessel of the TOSKA facility. A unique feature is the upside down orientation of the current leads due to the location of the power supplies in the basement of the experimental area of W7-X. The HTS-CL consists of three main parts: the cold end for the connection to the bus bar at 4.5 K, the HTS part operating in the temperature range from 4.5 K to 65 K and a copper heat exchanger (HEX) in the temperature range from 65 K to room temperature, which is cooled with 50 K helium. Therefore in TOSKA it is possible to cool test specimens simultaneously with helium at two different temperature levels. The current lead tests included different scenarios with currents up to 18.2 kA. In total, 10 cryogenic test campaigns with a total time of about 24 weeks were performed till beginning of 2013. The test facility as well as the 2 kW cryogenic plant of ITEP showed a very good reliability. However, during such a long and complex experimental campaign, one has to deal with failures, technical difficulties and incidents. The paper gives a summary of the test performance comprising the test preparation and operation. This includes the performance and reliability of the refrigerator and the test facility with reference to the process measuring and control system, the data acquisition system, as well as the building infrastructure.

Richter, Thomas; Lietzow, Ralph [Karlsruhe Institute of Technology, Institute for Technical Physics (ITEP), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2014-01-29T23:59:59.000Z

153

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

Science Journals Connector (OSTI)

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

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

2011-01-27T23:59:59.000Z

154

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

Science Journals Connector (OSTI)

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

Ziauddin Khan; Subrata Pradhan; Irfan Ahmed

2014-01-01T23:59:59.000Z

155

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

Science Journals Connector (OSTI)

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

Madan Lal; R K Choudhury

1988-05-01T23:59:59.000Z

156

Optimization of superconducting tiling pattern for superconducting bearings  

DOE Patents [OSTI]

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

Hull, J.R.

1996-09-17T23:59:59.000Z

157

Optimization of superconducting tiling pattern for superconducting bearings  

DOE Patents [OSTI]

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

Hull, John R. (Hinsdale, IL)

1996-01-01T23:59:59.000Z

158

Modeling and experimental investigation of microstrip resonators and filters based on High-Temperature Superconductor films  

Science Journals Connector (OSTI)

Complex approach to the investigation of microstrip resonators and filters based on High-Temperature Superconductor (HTS) films is described, which includes...

M. F. Sitnikova; I. B. Vendik; O. G. Vendik; D. V. Kholodnyak…

2010-09-01T23:59:59.000Z

159

Test results for a Bi-2223 HTS racetrack coil for generator applications  

SciTech Connect (OSTI)

Testing, results and analysis of a Bi-2223 model superconducting generator coil produced under the DOE Superconductivity Partnership Initiative are presented. The test arrangement enables coil energization with dc and transient currents over a range of operating temperatures to explore coil performance under conditions analogous to those that would be experienced by a superconducting generator field coil. Analytical calculations of coil ac and ohmic losses and temperature rise compare well with experimental measurements. Good performance is predicted for a typical 3-phase fault condition. Coil steady state and transient performance can be predicted with confidence for full scale superconductor application.

Salasoo, L.; Herd, K.G.; Laskaris, E.T.; Hart, H.R. Jr.; Chari, M.V.K. [GE Corporate Research and Development Center, Schenectady, NY (United States)

1996-12-31T23:59:59.000Z

160

Operation of a test bed axial-gap brushless dc rotor with a superconducting stator  

SciTech Connect (OSTI)

A variable-speed axial-gap motor with a stator consisting of four liquid helium cooled superconducting electromagnets (two pole pairs) was built and proof tested up to 608 rpm in November 1990 as a tool for joint industry-laboratory evaluation of coils fabricated from high-temperature oxide superconductors. A second rotor was fabricated with improved materia winding configuration, and wire type, and the drive system was modified to eliminate current spiking. The modified motor was characterized to design speed, 188 rad/s (1800 rpm), to acquire a performance baseline for future comparison with that of high-temperature superconducting (HIS) wire. As it becomes commercially available, HTS wire will replace the low-temperature electromagnet wire in a stator modified to control wire temperatures between 4 K and 77 K. Measurements of the superconducting electromagnetic field and locked rotor torque as functions of cryocurrent and dc current through two phases of the rotor, respectively, provided data to estimate power that could be developed by the rotor. Back emf and parasitic mechanical and electromagnetic drag torques were measured as functions of angular velocity to calculate actual rotor power developed and to quantify losses, which reduce the motor`s efficiency. A detailed measurement of motor power at design speed confirmed the developed power equation. When subsequently operated at the 33-A maximum available rotor current, the motor delivered 15.3 kill (20.5 hp) to the load. In a final test, the cryostat was operated at 2500 A, 200 A below its critical current. At rotor design current of 60 A and 2500 A stator current, the extrapolated developed power would be 44.2 kill (59.2 hp) with 94% efficiency.

McKeever, J.W.; Sohns, C.W.; Schwenterly, S.W.; Young, R.W. Sr.; Campbell, V.W.; Hickey, M.H.; Ott, G.W. [Oak Ridge National Lab., TN (United States); Bailey, J.M. [Tennessee Univ., Knoxville, TN (United States)

1993-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

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

162

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

163

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

164

Magnetism and Superconductivity in Iron Pnictides  

SciTech Connect (OSTI)

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

Singh, David J [ORNL

2012-01-01T23:59:59.000Z

165

Nanostructured high-temperature superconductors: Creation of strong-pinning columnar defects in  

E-Print Network [OSTI]

Nanostructured high-temperature superconductors: Creation of strong-pinning columnar defects the growth and incorporation of MgO nanorods into high temperature superconductors (HTS's) has been developed a limitation to the performance of HTS materials at high temperatures and magnetic fields.11­13 The traditional

Yang, Peidong

166

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

Science Journals Connector (OSTI)

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

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

1997-01-01T23:59:59.000Z

167

Superconductivity of Zirconium Alloys  

Science Journals Connector (OSTI)

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

B. T. Matthias and E. Corenzwit

1955-10-15T23:59:59.000Z

168

Hydro-Thermal Scheduling (HTS) 1.0 Introduction  

E-Print Network [OSTI]

1 Hydro-Thermal Scheduling (HTS) 1.0 Introduction From an overall systems view, the single most, relative to that of thermal plants, are very small. There are three basic types of hydroelectric plants;2 Pump-storage This kind of hydro plant is a specialized reservoir-type plant which has capability to act

McCalley, James D.

169

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 14, NO. 2, JUNE 2004 883 Design and Cooling Characteristic Results  

E-Print Network [OSTI]

Characteristic Results of Cryogenic System for 6.6 kV/200 A Inductive Fault Current Limiter Hyoungku Kang, Min-cooled cryogenic cooling system for 1.2 kV/80 A inductive Superconducting Fault Current Limiter (SFCL.830309 TABLE I CHARACTERISTICS OF HTS TAPES tics of the sub-cooled nitrogen cooling system for DC reactor of 6

Chang, Ho-Myung

170

High Temperature Superconductors: From Delivery to Applications (Presentation from 2011 Ernest Orlando Lawrence Award-winner, Dr. Amit Goyal, and including introduction by Energy Secretary, Dr. Steven Chu)  

SciTech Connect (OSTI)

Dr. Amit Goyal, a high temperature superconductivity (HTS) researcher at Oak Ridge National Laboratory, was named a 2011 winner of the Department of Energy's Ernest Orlando Lawrence Award honoring U.S. scientists and engineers for exceptional contributions in research and development supporting DOE and its mission. Winner of the award in the inaugural category of Energy Science and Innovation, Dr. Goyal was cited for his work in 'pioneering research and transformative contributions to the field of applied high temperature superconductivity, including fundamental materials science advances and technical innovations enabling large-scale applications of these novel materials.' Following his basic research in grain-to-grain supercurrent transport, Dr. Goyal focused his energy in transitioning this fundamental understanding into cutting-edge technologies. Under OE sponsorship, Dr. Goyal co-invented the Rolling Assisted Bi-Axially Textured Substrate technology (RABiTS) that is used as a substrate for second generation HTS wires. OE support also led to the invention of Structural Single Crystal Faceted Fiber Substrate (SSIFFS) and the 3-D Self Assembly of Nanodot Columns. These inventions and associated R&D resulted in 7 R&D 100 Awards including the 2010 R&D Magazine's Innovator of the Year Award, 3 Federal Laboratory Consortium Excellence in Technology Transfer National Awards, a DOE Energy100 Award and many others. As a world authority on HTS materials, Dr. Goyal has presented OE-sponsored results in more than 150 invited talks, co-authored more than 350 papers and is a fellow of 7 professional societies.

Goyal, Amit (Oak Ridge National Laboratory) [Oak Ridge National Laboratory

2012-05-22T23:59:59.000Z

171

High Temperature Superconductors: From Delivery to Applications (Presentation from 2011 Ernest Orlando Lawrence Award-winner, Dr. Amit Goyal, and including introduction by Energy Secretary, Dr. Steven Chu)  

ScienceCinema (OSTI)

Dr. Amit Goyal, a high temperature superconductivity (HTS) researcher at Oak Ridge National Laboratory, was named a 2011 winner of the Department of Energy's Ernest Orlando Lawrence Award honoring U.S. scientists and engineers for exceptional contributions in research and development supporting DOE and its mission. Winner of the award in the inaugural category of Energy Science and Innovation, Dr. Goyal was cited for his work in 'pioneering research and transformative contributions to the field of applied high temperature superconductivity, including fundamental materials science advances and technical innovations enabling large-scale applications of these novel materials.' Following his basic research in grain-to-grain supercurrent transport, Dr. Goyal focused his energy in transitioning this fundamental understanding into cutting-edge technologies. Under OE sponsorship, Dr. Goyal co-invented the Rolling Assisted Bi-Axially Textured Substrate technology (RABiTS) that is used as a substrate for second generation HTS wires. OE support also led to the invention of Structural Single Crystal Faceted Fiber Substrate (SSIFFS) and the 3-D Self Assembly of Nanodot Columns. These inventions and associated R&D resulted in 7 R&D 100 Awards including the 2010 R&D Magazine's Innovator of the Year Award, 3 Federal Laboratory Consortium Excellence in Technology Transfer National Awards, a DOE Energy100 Award and many others. As a world authority on HTS materials, Dr. Goyal has presented OE-sponsored results in more than 150 invited talks, co-authored more than 350 papers and is a fellow of 7 professional societies.

Goyal, Amit (Oak Ridge National Laboratory)

2012-06-28T23:59:59.000Z

172

APPLIED HTS BULKS AND WIRES TO ROTATING MACHINES FOR MARINE PROPULSION  

Science Journals Connector (OSTI)

High?temperature superconductors allow a compact and efficient way to provide high?torque density to rotating machines with excellent operation. A field pole providing flux density of more than 1.5 T around the armature was initially designed for an axial?gap type with the flux parallel to the rotor axis. Melt?growth Gd?123 bulks as well as Bi?2223 wire windings have been successfully assembled on the rotor disk. No iron core was used though being an auxiliary flux control found in most HTS motors. Both bulk and wire types have realized a practical motor operation within a limited output range. For bulks a 15 kW 720 rpm synchronous motor was designed and tested in the group of TUMSAT Kitano Seiki and University of Fukui. A bulk field pole was cooled down by liquid nitrogen and was magnetized in the motor. To enhance the output power to more than 30 kW we developed a thermosyphon system using condensed neon. Another field pole with HTS wire for large?scale marine propulsion is also discussed on a 100 kW 230 rpm tested machine. A closed?cycle condensed neon associated with thermal insulation is also reported.

M. Miki; B. Felder; Y. Kimura; K. Tsuzuki; R. Taguchi; Y. Shiliang; Y. Xu; T. Ida; M. Izumi

2010-01-01T23:59:59.000Z

173

Superconductive articles including cerium oxide layer  

DOE Patents [OSTI]

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

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

1993-01-01T23:59:59.000Z

174

Superconducting Cable  

DOE Patents [OSTI]

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

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

2005-07-22T23:59:59.000Z

175

Superconducting Cable  

DOE Patents [OSTI]

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

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

2005-03-08T23:59:59.000Z

176

Prospects for the Use of HTS in High Field Magnets for Future Accelerator Facilities  

E-Print Network [OSTI]

The enthusiasm that followed discovery of High Temperature Superconductors (HTS) and the initial genuine hope of a replacement technology that could have taken over from conventional Low Temperature Superconductors (LTS) was damped during the years by difficulties in reaching performance levels of competing materials: insufficient current-carrying performance, short piece lengths, and fragility of the brittle oxide superconductors made development of applications slow and limited to demonstrators or devices less demanding from the point of view of conductor performance. However, thanks to a continuous R&D effort, significant progress was made in the past years on the development of cuprate superconductors. Today long lengths of BSCCO 2223 (km range) and REBCO (a more general acronym for YBCO, where RE = Rare Earth) tape (hundreds of meters range) conductor with controlled and homogeneous characteristics are commercially available, and tremendous progress has been made in the development of BSSCO 2212 roun...

Ballarino, A

2014-01-01T23:59:59.000Z

177

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

178

10MW Class Direct Drive HTS Wind Turbine, CRADA Number CRD-08...  

Office of Scientific and Technical Information (OSTI)

10MW Class Direct Drive HTS Wind Turbine Cooperative Research and Development Final Report CRADA Number: CRD-08-00312 NREL Technical Contact: Walter Musial CRADA Report NREL...

179

Superconductivity | ORNL Neutron Sciences  

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

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

180

Development and Test of a Prototype 100MVA Superconducting Generator  

SciTech Connect (OSTI)

In 2002, General Electric and the US Department of Energy (DOE) entered into a cooperative agreement for the development of a commercialized 100 MVA generator using high temperature superconductors (HTS) in the field winding. The intent of the program was to: • Identify and develop technologies that would be needed for such a generator. • Develop conceptual designs for generators with ratings of 100 MVA and higher using HTS technology. • Perform proof of concept tests at the 1.5 MW level for GE’s proprietary warm iron rotor HTS generator concept. • Design, build, and test a prototype of a commercially viable 100 MVA generator that could be placed on the power grid. This report summarizes work performed during the program and is provided as one of the final program deliverables.

Fogarty, James M.; Bray, James W.

2007-05-25T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

Materials basis for a six-level epitaxial HTS digital circuit process  

SciTech Connect (OSTI)

We have developed a process for fabrication of HTS single-flux-quantum logic circuits based on edge SNS junctions which requires six epitaxial film layers and six mask levels. The process was successfully applied to fabrication of small-scale circuits ({le} 10 junctions). This paper examines the materials properties affecting the reproducibility of YBCO-based SNS junctions, the low inductance provided by an integrated YBCO ground plane, and electrical isolation by SrTiO{sub 3} or SrAlTaO{sub 6} ground-plane and junction insulator layers. Some of the critical processing parameters identified by electrical measurements, TEM, SEM, and AFM were control of second-phase precipitates in YBCO, oxygen diffusion, Ar ion milling parameters, and preparation of surfaces for subsequent high-temperature depositions.

Talvacchio, J.; Forrester, M.G.; Hunt, B.D. [Northrop Grumman Science and Technology Center, Pittsburgh, PA (United States)] [and others

1996-12-31T23:59:59.000Z

182

Big fast vortices in the d-wave resonating valence bond theory of high-temperature superconductivity  

Science Journals Connector (OSTI)

The effect of proximity to a Mott insulating phase on the superflow properties of a d-wave superconductor is studied using the slave-boson U(1)-gauge-theory model. The model has two limits corresponding to superconductivity emerging either out of a “renormalized Fermi-liquid” or out of a non-Fermi-liquid regime. Three crucial physical parameters are identified: the size of the vortex as determined from the supercurrent it induces, the coupling of the superflow to the quasiparticles, and the “nondissipative time derivative” term. As the Mott phase is approached, the core size as defined from the supercurrent diverges, the coupling between superflow and quasiparticles vanishes, and the magnitude of the nondissipative time derivative dramatically increases. The dissipation due to a moving vortex is found to vary as the third power of the doping. The upper critical field and the size of the critical regime in which paraconductivity may be observed are estimated and found to be controlled by the supercurrent length scale.

L. B. Ioffe and A. J. Millis

2002-09-18T23:59:59.000Z

183

Finite-element modelling of YBCO fault current limiter with temperature dependent  

Science Journals Connector (OSTI)

In this paper, we present a numerical model which takes into account both the thermal and the electromagnetic aspects of the over-critical current regime for high-temperature superconducting (HTS) materials. The electromagnetic and thermal equations have been implemented in finite-element method (FEM) software in order to obtain a novel model for investigating the behaviour of the materials when the current exceeds Ic and the superconductor material goes to the normal state. The thermal dependence of the electrical parameters, such as the critical current density Jc, has been introduced. This model has been used to analyse the behaviour of strip lines of a YBCO/Au fault current limiter (FCL) on a sapphire substrate. Simulations with currents exceeding Ic have been performed, showing that the current limitation phase can be correctly reproduced. Such a model can be used to study the influence of the geometry on the performance of the FCL. It can replace experiments with currents exceeding Ic which may damage or destroy HTS samples and devices.

J Duron; F Grilli; L Antognazza; M Decroux; B Dutoit; Ø Fischer

2007-01-01T23:59:59.000Z

184

Cryocooler Applications for High-Temperature Superconductor Magnetic Bearings  

Science Journals Connector (OSTI)

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

R. C. Niemann; J. R. Hull

2002-01-01T23:59:59.000Z

185

HTS cables open the window for large-scale renewables  

Science Journals Connector (OSTI)

In a realistic approach to future energy consumption, the effects of sustainable power sources and the effects of growing welfare with increased use of electricity need to be considered. These factors lead to an increased transfer of electric energy over the networks. A dominant part of the energy need will come from expanded large-scale renewable sources. To use them efficiently over Europe, large energy transits between different countries are required. Bottlenecks in the existing infrastructure will be avoided by strengthening the network. For environmental reasons more infrastructure will be built underground. Nuon is studying the HTS technology as a component to solve these challenges. This technology offers a tremendously large power transport capacity as well as the possibility to reduce short circuit currents, making integration of renewables easier. Furthermore, power transport will be possible at lower voltage levels, giving the opportunity to upgrade the existing network while re-using it. This will result in large cost savings while reaching the future energy challenges. In a 6 km backbone structure in Amsterdam Nuon wants to install a 50 kV HTS Triax cable for a significant increase of the transport capacity, while developing its capabilities. Nevertheless several barriers have to be overcome.

A Geschiere; D Willén; E Piga; P Barendregt

2008-01-01T23:59:59.000Z

186

Landscape of superconducting membranes  

E-Print Network [OSTI]

The AdS/CFT correspondence may connect the landscape of string vacua and the `atomic landscape' of condensed matter physics. We study the stability of a landscape of IR fixed points of N=2 large N gauge theories in 2+1 dimensions, dual to Sasaki-Einstein compactifications of M theory, towards a superconducting state. By exhibiting instabilities of charged black holes in these compactifications, we show that many of these theories have charged operators that condense when the theory is placed at a finite chemical potential. We compute a statistical distribution of critical superconducting temperatures for a subset of these theories. With a chemical potential of one milliVolt, we find critical temperatures ranging between 0.24 and 165 degrees Kelvin.

Frederik Denef; Sean A. Hartnoll

2009-03-20T23:59:59.000Z

187

An overview of rotating machine systems with high-temperature bulk superconductors  

Science Journals Connector (OSTI)

The paper contains a review of recent advancements in rotating machines with bulk high-temperature superconductors (HTS). The high critical current density of bulk HTS enables us to design rotating machines with a compact configuration in a practical scheme. The development of an axial-gap-type trapped flux synchronous rotating machine together with the systematic research works at the Tokyo University of Marine Science and Technology since 2001 are briefly introduced. Developments in bulk HTS rotating machines in other research groups are also summarized. The key issues of bulk HTS machines, including material progress of bulk HTS, in situ magnetization, and cooling together with AC loss at low-temperature operation are discussed.

Difan Zhou; Mitsuru Izumi; Motohiro Miki; Brice Felder; Tetsuya Ida; Masahiro Kitano

2012-01-01T23:59:59.000Z

188

Modeling of Shield-Type Superconducting Fault-Current-Limiter Operation Considering Flux Pinning Effect on Flux and Supercurrent Density in High-Temperature Superconductor Cylinders  

Science Journals Connector (OSTI)

Superconducting fault current limiter, SFCL, forms an important category of fault-current-limiting devices which limit the short-circuit current levels in electrical networks. Therefore, modeling ... its main ope...

Arsalan Hekmati

2014-03-01T23:59:59.000Z

189

Detection limits of high temperature superconducting materials on various substrates by energy dispersive X-ray fluorescence and proton induced X-ray emission methods  

Science Journals Connector (OSTI)

Application of energy dispersive X-ray fluorescence (EDXRF) and proton induced X-ray emission (PIXE) methods has been demonstrated for determining the elemental composition of thin film superconducting materia...

M Lal; H N Bajpai; D Joseph; R K Choudhury

1990-04-01T23:59:59.000Z

190

Superconductive articles including cerium oxide layer  

DOE Patents [OSTI]

A ceramic superconductor comprising a metal oxide substrate, a ceramic high temperature superconductive material, and a intermediate layer of a material having a cubic crystal structure, said layer situated between the substrate and the superconductive material is provided, and a structure for supporting a ceramic superconducting material is provided, said structure comprising a metal oxide substrate, and a layer situated over the surface of the substrate to substantially inhibit interdiffusion between the substrate and a ceramic superconducting material deposited upon said structure. 7 figures.

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

1993-11-16T23:59:59.000Z

191

Dynamic simulation of 10 kW Brayton cryocooler for HTS cable  

SciTech Connect (OSTI)

Dynamic simulation of a Brayton cryocooler is presented as a partial effort of a Korean governmental project to develop 1?3 km HTS cable systems at transmission level in Jeju Island. Thermodynamic design of a 10 kW Brayton cryocooler was completed, and a prototype construction is underway with a basis of steady-state operation. This study is the next step to investigate the transient behavior of cryocooler for two purposes. The first is to simulate and design the cool-down process after scheduled or unscheduled stoppage. The second is to predict the transient behavior following the variation of external conditions such as cryogenic load or outdoor temperature. The detailed specifications of key components, including plate-fin heat exchangers and cryogenic turbo-expanders are incorporated into a commercial software (Aspen HYSYS) to estimate the temporal change of temperature and flow rate over the cryocooler. An initial cool-down scenario and some examples on daily variation of cryocooler are presented and discussed, aiming at stable control schemes of a long cable system.

Chang, Ho-Myung; Park, Chan Woo [Hong Ik University, Department of Mechanical Engineering, Seoul, 121-791 (Korea, Republic of); Yang, Hyung Suk; Hwang, Si Dole [KEPCO Research Institute, Daejeon, 305-760 (Korea, Republic of)

2014-01-29T23:59:59.000Z

192

Dynamic simulation of 10 kW Brayton cryocooler for HTS cable  

Science Journals Connector (OSTI)

Dynamic simulation of a Brayton cryocooler is presented as a partial effort of a Korean governmental project to develop 1?3 km HTS cable systems at transmission level in Jeju Island. Thermodynamic design of a 10 kW Brayton cryocooler was completed and a prototype construction is underway with a basis of steady-state operation. This study is the next step to investigate the transient behavior of cryocooler for two purposes. The first is to simulate and design the cool-down process after scheduled or unscheduled stoppage. The second is to predict the transient behavior following the variation of external conditions such as cryogenic load or outdoor temperature. The detailed specifications of key components including plate-fin heat exchangers and cryogenic turbo-expanders are incorporated into a commercial software (Aspen HYSYS) to estimate the temporal change of temperature and flow rate over the cryocooler. An initial cool-down scenario and some examples on daily variation of cryocooler are presented and discussed aiming at stable control schemes of a long cable system.

2014-01-01T23:59:59.000Z

193

Superconducting fault current limiter with fast vacuum commutation modulus  

Science Journals Connector (OSTI)

A new approach to a problem of creation of a resistive version of superconducting fault current limiters (FCL) on the basis of HTS materials has been considered. According to this approach, a scheme of FCL is added by a commutation modulus which contains a fast vacuum interrupter. This interrupter allows one to switch off the transport current as soon as 5 ms after transition of the HTS element to the normal state. The proposed scheme allows one to restrict more than an order in value a necessary operation time of FCL in a regime of a current limitation. As a result, a time of recovering the superconducting state can be significantly reduced that allows FCL to operate in automatic iterative regime. The considering device can operate not only in high voltage ac transmission lines but also in dc electrical networks. A numerical simulation of transit processes in a proposed scheme of FCL has been performed for different regimes and its features are analyzed with respect to other schemes of FCL. An experimental study of test mock-up commutation elements of FCL has been performed. This study demonstrates an efficiency of the proposed scheme. A test of a FCL model with the limiting current up to 15 kA has been realized.

D Alferov; D Yevsin; L Fisher; V Ivanov; V Sidorov

2008-01-01T23:59:59.000Z

194

Fabrication of arrays of nano-superconducting quantum interfernce devices using a double-angle processing approach  

E-Print Network [OSTI]

SQUIDs) from high-temperature superconductors such as YBCOsuperconductors. However, the thermal noise inform the increased operating temperature os high-high-temperature superconductivity, Josephson junctions, electron beam lithography I. I NTRODUCTION Superconducting interference devices (SQUIDs) from conventional superconductors

Roediger, Peter

2014-01-01T23:59:59.000Z

195

The high voltage problem in the saturated core HTS fault current limiter  

Science Journals Connector (OSTI)

A small model of a one-phase saturated core HTS fault current limiter was developed. It consists of an iron core, an AC coil and a DC HTS coil. The HTS coil comprised six 126 turns double-pancakes (ID 70 mm), wound after heat treatment from Bi-2223 multifilamentary tape in Ag matrix. A fault simulation circuit was set up to characterize the dynamic properties of the model limiter. The voltages and currents of the AC coil and the DC HTS coil were measured through a computer-based data acquisition system. The tests have shown that the limiter has a fast response and the first current peak can be easily limited, but a high voltage will be induced on the DC HTS coil side during the fault state. This high voltage can badly affect the DC current equipment on the DC HTS coil side. The origin and value of the high voltage can be explained using a transformer model. For a limiter with n1 turns AC coil and n2 turns DC coil, the largest induced voltage will be roughly close to (n2/n1)U, where U is the rated voltage of the limiter. To commercialize this kind of limiter, the high voltage problem must be solved. Some different designs were introduced to lower the induced voltage.

Y.F. He; J.H. Li; X.H. Zong; J. Sun; Y.N. Wang; C.L. Wu; J.X. Wang

2003-01-01T23:59:59.000Z

196

Molybdenum-rhenium superconducting suspended nanostructures  

SciTech Connect (OSTI)

Suspended superconducting nanostructures of MoRe 50%/50% by weight are fabricated employing commonly used fabrication steps in micro- and nano-meter scale devices followed by wet-etching with Hydro-fluoric acid of a SiO{sub 2} sacrificial layer. Suspended superconducting channels as narrow as 50?nm and length 3??m have a critical temperature of ?6.5?K, which can increase by 0.5?K upon annealing at 400?°C. A detailed study of the dependence of the superconducting critical current and critical temperature upon annealing and in devices with different channel widths reveals that desorption of contaminants is responsible for the improved superconducting properties. These findings pave the way for the development of superconducting electromechanical devices using standard fabrication techniques.

Aziz, Mohsin; Christopher Hudson, David; Russo, Saverio [Centre for Graphene Science, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF (United Kingdom)

2014-06-09T23:59:59.000Z

197

SciTech Connect: Ultrasonic signatures at the superconducting...  

Office of Scientific and Technical Information (OSTI)

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

198

Superconducting Topological Insulators  

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

Superconducting Topological Insulators Print Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be taken even further. Their studies showed that by doping the TI, bismuth selenide, with copper, it's possible to make the topologically ordered electrons superconducting, dropping electrical resistance in the surface states all the way to zero.

199

Superconducting Topological Insulators  

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

Superconducting Topological Insulators Print Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be taken even further. Their studies showed that by doping the TI, bismuth selenide, with copper, it's possible to make the topologically ordered electrons superconducting, dropping electrical resistance in the surface states all the way to zero.

200

Superconducting Topological Insulators  

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

Superconducting Topological Insulators Print Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be taken even further. Their studies showed that by doping the TI, bismuth selenide, with copper, it's possible to make the topologically ordered electrons superconducting, dropping electrical resistance in the surface states all the way to zero.

Note: This page contains sample records for the topic "temperature superconducting hts" 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

Processes yielding high superconducting temperatures  

SciTech Connect (OSTI)

It is pointed out that any microscopic description of the new high-T/sub c/ superconductors should take into account a number of important points concerning strong couplings, whatever their nature: absence of the MacMillan limit, absence of a Migdal theorem, and importance of the Brovman-Kagan type of vertices with different singularities depending on the dimensionality. As a consequence, the applicability of standard techniques such as the Eliashberg theory in particular, may be questioned in high-T/sub c/ superconductors.

Beal-Monod, M.T.

1987-12-01T23:59:59.000Z

202

Applied High-Temperature Superconductor Bulks and Wires to Rotating Machines for Marine Propulsion  

Science Journals Connector (OSTI)

High-temperature superconductors (HTS) allow providing to high-torque density rotating machines a compact, efficient, and excellent operation. Field poles that act as magnets, providing a magnetic field of more t...

Brice Felder; Motohiro Miki; Yosuke Kimura…

2011-01-01T23:59:59.000Z

203

Features of technology of high-temperature superconductor films for microwave filters  

Science Journals Connector (OSTI)

The characteristics of fourth-order bandpass microwave filters based on high-temperature super-conductor (HTS) films have been numerically simulated and experimentally measured for the devices based on YBCO fi...

I. B. Vendik; O. G. Vendik; K. N. Zemlyakov; I. V. Kolmakova…

2011-05-01T23:59:59.000Z

204

Superconductivity for electric power systems: Program overview  

SciTech Connect (OSTI)

Largely due to government and private industry partnerships, electric power applications based upon high-temperature superconductivity are now being designed and tested only seven years after the discovery of the high-temperature superconductors. These applications offer many benefits to the national electric system including: increased energy efficiency, reduced equipment size, reduced emissions, increased stability/reliability, deferred expansion, and flexible electricity dispatch/load management. All of these benefits have a common outcome: lower electricity costs and improved environmental quality. The U.S. Department of Energy (DOE) sponsors research and development through its Superconductivity Program for Electric Power Systems. This program will help develop the technology needed for U.S. industries to commercialize high-temperature superconductive electric power applications. DOE envisions that by 2010 the U.S. electric power systems equipment industry will regain a major share of the global market by offering superconducting products that outperform the competition.

Not Available

1995-02-01T23:59:59.000Z

205

Electronic structure of superconductivity refined  

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

Electronic structure of superconductivity refined Electronic structure of superconductivity refined Electronic structure of superconductivity refined A team of physicists propose a new model that expands on a little understood aspect of the electronic structure in high-temperature superconductors. July 10, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.

206

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

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

207

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

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

208

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

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

209

Permanent magnet design for high-speed superconducting bearings  

DOE Patents [OSTI]

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

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

1996-09-10T23:59:59.000Z

210

MIT Lincoln LaboratoryHTS: MTI-UAV Cueing Experiment LAB/RAK 1/24/2006  

E-Print Network [OSTI]

MIT Lincoln LaboratoryHTS: MTI-UAV Cueing Experiment LAB/RAK 1/24/2006 Lawrence Bush 2006 January 24 Semi-Automated Cueing of Predator UAV Operators from RADAR Moving Target (MTI) Data MIT Lincoln and are not necessarily endorsed by the United States Government. #12;MIT Lincoln LaboratoryHTS: MTI-UAV Cueing Experiment

Cummings, Mary "Missy"

211

Information entropic superconducting microcooler  

Science Journals Connector (OSTI)

We consider a design for a cyclic microrefrigerator using a superconducting flux qubit. Adiabatic modulation of the flux combined with thermalization can be used to transfer energy from a lower temperature normal metal thin film resistor to another one at higher temperature. The frequency selectivity of photonic heat conduction is achieved by including the hot resistor as part of a high frequency LC resonator and the cold one as part of a low-frequency oscillator while keeping both circuits in the underdamped regime. We discuss the performance of the device in an experimentally realistic setting. This device illustrates the complementarity of information and thermodynamic entropy as the erasure of the quantum bit directly relates to the cooling of the resistor.

A. O. Niskanen; Y. Nakamura; J. P. Pekola

2007-11-29T23:59:59.000Z

212

Electrical-Thermal-Structural Coupled Finite Element Model of High Temperature Superconductor for Resistive Type Fault Current Limiters  

Science Journals Connector (OSTI)

A multi-physics finite element model of high-temperature superconductors (HTS) will be presented in this article. The electrical-thermal model is mainly based on Maxwell’s equation and basic heat transfer equa...

J. Sheng; Y. Chen; B. Lin; L. Ying; Z. Jin…

2014-06-01T23:59:59.000Z

213

HTS coil and joint development for a 5T NMR insert coil  

SciTech Connect (OSTI)

A HTS coil fabrication and joint development project was undertaken to develop the technology necessary for the production of a 5 T HTS insert coil for NMR applications. A series of minicoils are being fabricated to explore various construction options such as winding technique, structural support, and electrical insulation. The results from one of these coils are presented. Present conductor technology cannot produce the long length of conductor needed in the insert coil design, therefore, a means must be found to join several lengths of conductor together. Several joint prototypes are investigated.

Shoaff, P.V. Jr.; Schwartz, J.; Van Sciver, S.W. [National High Magnetic Field Lab., Tallahassee, FL (United States); [Florida State Univ. College, Tallahassee, FL (United States)] [and others

1996-12-31T23:59:59.000Z

214

ANALYSIS OF FUTURE PRICES AND MARKETS FOR HIGH TEMPERATURE SUPERCONDUCTORS  

E-Print Network [OSTI]

1 ANALYSIS OF FUTURE PRICES AND MARKETS FOR HIGH TEMPERATURE SUPERCONDUCTORS BY JOSEPH MULHOLLAND of Future Prices and Markets for High Temperature Superconductors 2 I . PURPOSE, SCOPE AND APPROACH analysts to make estimates about the future of high temperature superconductor (HTS) technology

215

DOE Science Showcase - Understanding High-Temperature Superconductors |  

Office of Scientific and Technical Information (OSTI)

Understanding High-Temperature Superconductors Understanding High-Temperature Superconductors Credit: DOE Scientists have long worked to understand one of the great mysteries of modern physics - the origin and behavior of high-temperature superconductors (HTS) that are uniquely capable of transmitting electricity with zero loss when chilled to subzero temperatures. For decades there have been competing theories and misunderstandings of how HTS materials actually work and they have remained fundamentally puzzling to physicists. Solving this mystery has the potential to revolutionize the planet's energy infrastructure from generation to transmission and grid-scale storage. Recent technical breakthroughs in this quest are being discovered by DOE scientists and their collaborators. Read about HTS technology, basic

216

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

217

Secrets of superconductivity revealed  

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

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

218

Secrets of superconductivity revealed  

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

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

219

A dc superconducting fault current limiter using die-pressed  

Science Journals Connector (OSTI)

A model of a superconducting fault current limiter on a polycrystalline high-temperature superconductor basis is checked in the dc short circuit regime. Protection of load takes place under the conditions described in this paper. The use of ceramic materials with superconducting-normal metal-superconducting Josephson junction network having an S-type current-voltage characteristic (CVC) is shown to be effective for fault current limiter devices.

A G Mamalis; M I Petrov; D A Balaev; K A; D M Gohfeld; S V Militsyn; S G; V I Kirko; I N Vottea

2001-01-01T23:59:59.000Z

220

Cryogenic cooling system of HTS transformers by natural convection of subcooled liquid nitrogen  

E-Print Network [OSTI]

Cryogenic cooling system of HTS transformers by natural convection of subcooled liquid nitrogen Ho-793, South Korea Abstract Heat transfer analysis on a newly proposed cryogenic cooling system is performed, and over-load operation. One of the key techniques to realize these advantages in practice is the cryogenic

Chang, Ho-Myung

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


221

High Temperature Superconductors  

Science Journals Connector (OSTI)

Abstract A brief review of the phenomenology of superconductivity, the distinction between type I and type II superconductors, and the application of type II superconductors is followed by a history of the theory of conventional superconductivity. Unconventional high-temperature superconductivity in the copper oxides is reviewed as a phenomenon occurring in narrow two-dimensional bands where the time for an electron transfer between like atoms is comparable to the period of an optical-mode lattice vibration. A family of iron pnictides containing layers of iron atoms may not require an alternative explanation of its high-temperature superconductivity.

J.B. Goodenough

2013-01-01T23:59:59.000Z

222

The LHC superconducting cavities  

E-Print Network [OSTI]

The LHC RF system, which must handle high intensity (0.5 A d.c.) beams, makes use of superconducting single-cell cavities, best suited to minimizing the effects of periodic transient beam loading. There will be eight cavities per beam, each capable of delivering 2 MV (5 MV/m accelerating field) at 400 MHz. The cavities themselves are now being manufactured by industry, using niobium-on-copper technology which gives full satisfaction at LEP. A cavity unit includes a helium tank (4.5 K operating temperature) built around a cavity cell, RF and HOM couplers and a mechanical tuner, all housed in a modular cryostat. Four-unit modules are ultimately foreseen for the LHC (two per beam), while at present a prototype version with two complete units is being extensively tested. In addition to a detailed description of the cavity and its ancillary equipment, the first test results of the prototype will be reported.

Boussard, Daniel; Häbel, E; Kindermann, H P; Losito, R; Marque, S; Rödel, V; Stirbet, M

1999-01-01T23:59:59.000Z

223

High Tc Superconductivity  

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

224

Onset of surface superconductivity  

SciTech Connect (OSTI)

We examine the onset of superconductivity in the surface region of a metal. Surface effects are particularly important in systems with a short bulk coherence length {xi}{sub 0}. We show that, to the accuracy of the calculation, the surface transition temperature {ital T}{sub {ital c}{ital S}} equals the bulk transition temperature {ital T}{sub {ital c}{ital B}} if the electron-electron interaction is of the standard BCS form, i.e., a single attractive square well, extending up to some critical energy {omega}{sub 0} much smaller than the Fermi energy {var epsilon}{sub {ital F}}. If one takes into account, in addition, the repulsive part of the interaction extending beyond {omega}{sub 0} up to energies of order {var epsilon}{sub {ital F}}, then one may have {ital T}{sub {ital c}{ital S}}{gt}{ital T}{sub {ital c}{ital B}} in certain cases, although, due to restrictions imposed on the parameter values by various physical conditions, the relative increase of {ital T}{sub {ital c}} is very small, typically 10{sup {minus}3}, at least in the weak coupling limit. However, we also find a considerable gap enhancement, of order 20%, near the surface which could be of interest for critical-current measurements. Therefore we suggest an experimental reexamination of systems with short {xi}{sub 0}, i.e., superconducting degenerate semiconductors and the new high-{ital T}{sub {ital c}} oxides in confined geometries where the surface-to-volume ratio is non-negligible.

Giamarchi, T.; Beal-Monod, M.T. (Laboratoire de Physique des Solides, Universite Paris-Sud 91405 Orsay, (France)); Valls, O.T. (Laboratoire de Physique des Solides, Universite Paris-Sud, 91405 Orsay, (France) Center for the Science and Application of Superconductivity, School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (USA))

1990-06-01T23:59:59.000Z

225

Superconducting phase transitions in ultrathin TiN film.  

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

226

MICROSTRUCTURE OF SUPERCONDUCTING MGB(2).  

SciTech Connect (OSTI)

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

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

2001-07-12T23:59:59.000Z

227

Dynamic stress intensity factors of mode-I crack in high temperature superconductor  

Science Journals Connector (OSTI)

Abstract The coupled magneto-mechanical model is established for the dynamic fracture problem for the high temperature superconductor (HTS). The superconductor E–J constitutive law is characterized by power law model where the critical current density is assumed to depend exponentially on the flux density. The cracked superconductor under dynamic loading are employed to investigate dynamic fracture behavior such as the variation of dynamic stress intensity factors (DSIFs) for different applied magnetic field amplitude, the thickness of HTS, and critical current density. To evaluate \\{DSIFs\\} for a type-II superconductor under alternating magnetic field, the flux pinning induced magnetoelasticity model proposed to evaluate DSIFs, and is implemented in conjunction with finite element method. The results show that the applied magnetic field amplitude, thickness of HTS, and critical current density are three important factors affecting the dynamic fracture behavior of the HTS.

Zhiwen Gao; Youhe Zhou

2013-01-01T23:59:59.000Z

228

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

229

E-Print Network 3.0 - ag-clad bi-based superconducting Sample...  

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

Dependencies of Summary: of Bi-based high-temperature superconducting tapes," Physical Review B, vol. 45, pp. 2545-2548, 1992. 7... 2840 IEEE TRANSACTIONS ON APPLIED...

230

DESIGN REQUIREMENTS AND OPTIONS FOR FINAL FOCUSING SUPERCONDUCTING MAGNETS  

E-Print Network [OSTI]

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

California at San Diego, University of

231

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

E-Print Network [OSTI]

near Fig. 23 (a) Electrical resistivity ? vs. temperature Tcontribution to the electrical resistivity, ?, vs. T for Sc161: 4–54 Fig. 7 Electrical resistivity ? vs. T , speci?c

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

2010-01-01T23:59:59.000Z

232

Superconductivity in Bundles of Double-Wall Carbon Nanotubes  

E-Print Network [OSTI]

We present electrical and thermal specific heat measurements that show superconductivity in double-wall carbon nanotube (DWCNT) bundles. Clear evidence, comprising a resistance drop as a function of temperature, magnetoresistance ...

Shi, Wu

233

SciTech Connect: Enhanced Superconducting Gaps in Trilayer High...  

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

Enhanced Superconducting Gaps in Trilayer High-Temperature Bi (2) Sr (2) Ca (2) Cu (3) O (10+delta) Cuprate Superconductor Citation Details In-Document Search Title: Enhanced...

234

Superconductivity in primitive hexagonal germanium  

Science Journals Connector (OSTI)

We present a first-principles calculation of the electron-phonon coupling constant ? (mass enchancement parameter) for the primitive hexagonal, high-pressure structural phase of Ge (75 GPa?p?105 GPa). Using the calculated value of ?, we estimate the superconducting transition temperature Tc to be in the range of 2 to 7 K. We discuss the contributions to ? from the different phonon modes and its dependence on the phonon frequency, electron-phonon matrix elements, and Fermi-surface nesting. The results are compared with previous calculations for primitive hexagonal Si.

Jose Luis Martins and Marvin L. Cohen

1988-03-01T23:59:59.000Z

235

Temperature dependences of superconducting critical current density and upper critical field for V/sub 2/(Hf,Zr) multifilamentary wire  

SciTech Connect (OSTI)

The temperature dependences of the critical current density, J /SUB c/ , and the upper critical field, uH /SUB c2/ , have been studied for newly developed V/sub 2/(Hf,Zr) multifilamentary wires. At 4.2 K, a ..mu..H /SUB c2/ of 22 T and an overall J /SUB c/ of 1 x 10/sup 4/ A/cm/sup 2/ at 17 T are obtained for these wires. At 1.8 K, overall J /SUB c/ in 15 T of these wires are twice as large as that of the bronze-processed Nb/sub 3/Sn multifilamentary wire. The enhanced J /SUB c/ at reduced temperatures may be attributed to the rapid increase in ..mu..H /SUB c2/ by using the temperature scaling law of the pinning force density. ..mu..H /SUB c2/ measured in pulsed fields is about 28 T at 2.0 K. According to the temperature scaling law, the overall J /SUB c/ for 1.8 K and at 20 T is estimated to be 2 x 10/sup 4/ A/cm/sup 2/. Thus, the present V/sup 2/(Hf,Zr) multifilamentary wires are very promising for use of generating high magnetic fields in the superfluid liquid helium environment.

Inoue, K.; Kuroda, T.; Tachikawa, K.

1985-03-01T23:59:59.000Z

236

Superconducting Radiofrequency (SRF) Accelerator Cavities  

SciTech Connect (OSTI)

Charlie Reece, an accelerator technology scientist, explains how superconducting radiofrequency accelerator cavities work.

Reece, Charlie

2013-05-03T23:59:59.000Z

237

Superconducting Radiofrequency (SRF) Accelerator Cavities  

ScienceCinema (OSTI)

Charlie Reece, an accelerator technology scientist, explains how superconducting radiofrequency accelerator cavities work.

Reece, Charlie

2014-05-22T23:59:59.000Z

238

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

239

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

240

Levitation pressure and friction losses in superconducting bearings  

DOE Patents [OSTI]

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

Hull, John R. (Downers Grove, IL)

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

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.

242

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

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

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

243

Secrets of superconductivity revealed  

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

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

244

Alexei Abrikosov and Superconductivity  

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

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

245

Supertubes and Superconducting Membranes  

SciTech Connect (OSTI)

We show the equivalence between configurations that arise from string theory of type IIA, called supertubes, and superconducting membranes at the bosonic level. We find equilibrium and oscillating configurations for a tubular membrane carrying a current along its axis.

Cordero, Ruben; Miguel-Pilar, Zelin [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del IPN, Edificio 9, Unidad Profesional 'Adolfo Lopez Mateos', Zacatenco, 07738 Mexico D.F. (Mexico)

2007-02-09T23:59:59.000Z

246

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

E-Print Network [OSTI]

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

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

2014-01-01T23:59:59.000Z

247

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

248

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

249

Progress in Superconducting Metamaterials  

E-Print Network [OSTI]

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

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

2014-03-25T23:59:59.000Z

250

Partial insulation of GdBCO single pancake coils for protection-free HTS power  

Science Journals Connector (OSTI)

The partial insulation winding was examined to ameliorate the slow charge–discharge shown by coils wound without insulation. Single pancake coils of GdBCO coated conductor were wound without insulation, with kapton tape every five turns, and with the full use of kapton tape. They were characterized by charge–discharge, sudden discharge, and over-current testing. The improved charging and discharging and high thermal and electrical stabilities of the partially insulated coil demonstrate its potential for use in HTS power applications.

Y H Choi; S Hahn; J B Song; D G Yang; H G Lee

2011-01-01T23:59:59.000Z

251

The status and prospects for flywheels and SMES that incorporate HTS  

Science Journals Connector (OSTI)

With one firm offering to provide SMES with HTS current leads and several other entities developing flywheels with bearings that incorporate bulk ReBaCuO, the progress made toward meeting their technical goals appears promising. Another question needs attention from the research, development, and demonstration (RD&D) community: “Will technical success yield equipment that will sell?” Here, we recall what is being done and review issues touching on the specifications for equipment that customers might want. These specifications pose technical challenges that have received little attention from the community.

A.M. Wolsky

2002-01-01T23:59:59.000Z

252

Superconductivity with stripes | Argonne National Laboratory  

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

253

The Thermo-Electric Behavior of Tin and Silver at Liquid-Helium Temperatures  

Science Journals Connector (OSTI)

...vanishes abruptly at the superconducting transition temperature; this observation disagrees with the conclusions of Casimir Rademakers, who report a curious behaviour above the transition temperature which they hold to 'foreshadow' the onset of superconductivity...

1953-01-01T23:59:59.000Z

254

Qualification High Voltage Testing of Short Triax HTS Cables in the Laboratory  

SciTech Connect (OSTI)

In order to qualify the electrical insulation design of future HTS cables installed in the electric grid, a number of high voltage qualification tests are generally performed in the laboratory on either single-phase model cables and/or actual three-phase cable samples. Prior to installation of the 200-m Triax HTS cable at the American Electric Power Bixby substation near Columbus, Ohio, in September, 2006, such tests were conducted on both single-phase model cables made at ORNL and tri-axial cable sections cut off from cable made on a production run. The three-phase tri-axial design provides some specific testing challenges since the ground shield and three phases are concentric about a central former with each phase separated by dielectric tape insulation immersed in liquid nitrogen. The samples were successfully tested and qualified for partial discharge inception, AC withstand, and lightning impulse where voltage is applied to one phase with the other phases grounded. In addition one of the phase pairs was tested for dc withstand as a ldquoworst caserdquo scenario to simulate the effect of VLF (Very Low Frequency) tests on the actual cable installed at the Bixby site. The model and prototype cables will be described and the high voltage test results summarized.

James, David Randy [ORNL; Sauers, Isidor [ORNL; Ellis, Alvin R [ORNL; Tuncer, Enis [ORNL; Gouge, Michael J [ORNL; Demko, Jonathan A [ORNL; Duckworth, Robert C [ORNL; Rey, Christopher M [ORNL

2009-01-01T23:59:59.000Z

255

Temperature dependence of the gaps of high-temperature superconductors in the Fermi-arc region  

Science Journals Connector (OSTI)

It is shown how in a high-temperature superconductor, the length of the Fermi arc can be obtained from the doping dependence of the pseudogap and the superconducting gap. In the momentum region spanned by the Fermi arc, the pseudogap temperature dependence follows that of the superconducting gap. The close interconnection of the two gaps suggests that they are both an essential part of the high-temperature superconductivity.

S. Hüfner and F. Müller

2008-07-23T23:59:59.000Z

256

7 Superconductivity March 12, 2008  

E-Print Network [OSTI]

to measure. Current could be left flowing round a superconducting loop for several months without any and copper, do not seem to be superconducting, nor do the elements in Group IIA, such as calcium, but many

Thouless, David

257

Strong enhancement of superconductivity in a nanosized Pb bridge  

Science Journals Connector (OSTI)

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

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

2001-06-15T23:59:59.000Z

258

National High Magnetic Field Laboratory: Superconducting Wire  

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

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

259

STATEMENT OF CONSIDERATIONS REQUEST BY DUPONT SUPERCONDUCTIVITY...  

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

scale example of the usefulness of HTS separation technology to industry. WAIVER ACTION - ABSTRACT W(A)-99-008 REQUESTOR SUBCONTRACT SCOPE OF RATIONALE FOR DECISION WORK DuPont...

260

HigHligHts and BreaktHrougHs Pauling's rules, in a world of non-spherical atoms  

E-Print Network [OSTI]

HigHligHts and BreaktHrougHs Pauling's rules, in a world of non-spherical atoms roBert t. downs tenet of Pauling's Rules, which is that atoms are spheres of a single fixed size.Their analysis provides, explains the older ones. Keywords: Electron density distribution, Paulings rules, non-spherical atoms Jerry

Downs, Robert T.

Note: This page contains sample records for the topic "temperature superconducting hts" 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

CRYOGENIC SYSTEM FOR A 35 KV/90 MVA SATURATED IRON?CORE SUPERCONDUCTING FAULT CURRENT LIMITER  

Science Journals Connector (OSTI)

A cryogenic system was built as an open system for a 35 kV/90 MVA saturated iron?core superconducting fault current limiter. It consists of an annular cylindrical liquid nitrogen dewar cryogenic pipes sensors valves and a control unit. A HTS dc bias coil was immersed with liquid nitrogen in the dewar. The control circuit constantly monitors the liquid nitrogen level and controls the supply of liquid nitrogen in accordance with the liquid nitrogen level change. Nitrogen vapor was directly released into the environment. Heat loss under different working conditions such as no magnetization current 150 A magnetization current and on?grid condition was measured to evaluate the performance of the system. As compared with no magnetization current of the dc bias coil evaporation of liquid nitrogen increases about 20% under the on?grid condition.

H. Hong; W. Z. Gong; B. Tian; J. Y. Zhang; X. M. Hu; J. Z. Wang; X. Y. Niu; Y. Wang; L. F. Zhang; Y. W. Sun; T. Q. Wu; Y. Xin

2010-01-01T23:59:59.000Z

262

Superconducting articles of manufacture and method of producing same  

DOE Patents [OSTI]

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

263

High Temperature Superconductivity: Taming Serendipity (Thursday...  

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

predictive design of new families of superconductors. She is recognized for her work on superconductorsemiconductor proximity effects, elucidating the physical properties of the...

264

Towards measuring variations of Casimir energy by a superconducting cavity  

E-Print Network [OSTI]

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

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

2005-04-07T23:59:59.000Z

265

8 - Superconducting fault current limiters and power cables  

Science Journals Connector (OSTI)

Abstract: This chapter addresses the technology of superconducting power cables and superconducting fault current limiters. The first part of the chapter is a general summary of the electric power grid. This sets the stage for a discussion of the historical development of superconducting AC and DC cables, which begins with low temperature superconductor-based systems. It then describes the present state of superconducting cable technology and gives a summary of some of the major programs around the world. Whereas power cables may be thought of as a replacement for conventional power system components, fault current limiters and fault current controllers have no conventional equivalent in the power grid. Several conceptually different fault current limiter designs are described. Their state of development and installation on the power grid are described.

W. Hassenzahl

2012-01-01T23:59:59.000Z

266

9 - Superconducting fault current limiters and power cables  

Science Journals Connector (OSTI)

Abstract: This chapter addresses the technology of superconducting power cables and superconducting fault current limiters (FCL). The first part of the chapter is a general summary of the electric power grid. This sets the stage for a discussion of the historical development of superconducting AC and DC cables, which begins with low temperature superconductor (LTS)-based systems. It then describes the present status of superconducting cable technology and summarizes some of the major programs around the world. Whereas power cables may be thought of as a replacement for conventional power system components, \\{FCLs\\} and fault current controllers (FCC) have no conventional equivalent in the power grid. Several conceptually different FCL designs are described. The status of their development and installation on the power grid are described.

W. Hassenzahl

2013-01-01T23:59:59.000Z

267

Superconductivity in Binary Alloy Systems of the Rare Earths and of Thorium with Pt-Group Metals  

Science Journals Connector (OSTI)

Superconductivity has been discovered in many binary systems composed of transition metals having nearly empty and nearly filled d shells. With the exception of the Sc-Pt and Ce-Rh systems, all contain at least one superconducting phase and frequently more. By comparing the transition temperatures of analogous compounds, it is inferred that pure Rh should become superconducting above 10 mdeg and pure Pt at a considerably lower temperature.

T. H. Geballe; B. T. Matthias; V. B. Compton; E. Corenzwit; G. W. Hull; Jr.; L. D. Longinotti

1965-01-04T23:59:59.000Z

268

Langmuir vacuum and superconductivity  

SciTech Connect (OSTI)

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

269

Superconducting Magnet Division  

E-Print Network [OSTI]

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

Gupta, Ramesh

270

Electricity Reliability  

E-Print Network [OSTI]

Electricity Delivery and Energy Reliability High Temperature Superconductivity (HTS) Visualization in the future because they have virtually no resistance to electric current, offering the possibility of new electric power equipment with more energy efficiency and higher capacity than today's systems

271

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

SciTech Connect (OSTI)

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

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

1994-12-31T23:59:59.000Z

272

Collapse of superconductivity in a hybrid tin-graphene Josephson junction array  

E-Print Network [OSTI]

1 Collapse of superconductivity in a hybrid tin-graphene Josephson junction array Zheng Han1 of the Josephson junction array into a zero-temperature metallic state. The suppression of proximity, models involving specific types of Josephson junction arrays in which superconducting disks are coupled

Boyer, Edmond

273

Mechanism of Thickness Dependence of Critical Current Density in HTS YBaCuO7-x Film and Its Elimination Using Nano-Engineering  

E-Print Network [OSTI]

current carrying capability is jeopardized by a mysterious thickness dependence of the critical current density (Jc) --- Jc monotonically decreases with increasing thickness (t) at 77 K and self-field (SF). This poses a great challenge for both HTS...

Wang, Xiang

2008-01-01T23:59:59.000Z

274

Surface Impedance in the Surface Superconducting State  

Science Journals Connector (OSTI)

To enable a simple calculation of the microwave surface resistance, the surface superconducting state is approximated by a model in which a layer of uniform order parameter is considered superposed on the normal bulk. Appropriate values for the order parameter and thickness of this layer were chosen with the use of the numerical solutions of the Ginsburg-Landau equations by Fink and Kessinger. A Gorter-Casimir temperature dependence was used for the order parameter and the Maki temperature dependence for ?. Our experiments on Pb-In alloys at frequencies of 9.5, 23, and 55 Gc/sec are in good agreement with the calculations.

Allen Rothwarf; Jonathan I. Gittleman; Bruce Rosenblum

1967-03-10T23:59:59.000Z

275

Development of Ultra-Efficient Electric Motors Final Technical Report Covering work from April 2002 through September 2007  

SciTech Connect (OSTI)

High temperature superconducting (HTS) motors offer the potential for dramatic volume and loss reduction compared to conventional, high horspower, industrial motors. This report is the final report on the results of eight research tasks that address some of the issues related to HTS motor development that affect motor efficiency, cost, and reliability.

Rich Schiferl

2008-05-30T23:59:59.000Z

276

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

Science Journals Connector (OSTI)

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

M. A. Vasyutin

2013-12-01T23:59:59.000Z

277

Superconducting cuprate heterostructures for hot electron bolometers  

SciTech Connect (OSTI)

Transport properties of the resistive state of quasi-two dimensional superconducting heterostructures containing ultrathin La{sub 2?x}Sr{sub x}CuO{sub 4} layers synthesized using molecular beam epitaxy are studied. The electron transport exhibits strong deviation from Ohm's law, ?V??I{sup 3}, with a coefficient ?(T) that correlates with the temperature variation of the resistivity d?/dT. Close to the normal state, analysis of the nonlinear behavior in terms of electron heating yields an electron-phonon thermal conductance per unit area g{sub e?ph}?1 W/K cm{sup 2} at T = 20 K, one-two orders of magnitude smaller than in typical superconductors. This makes superconducting LaSrCuO heterostructures to be attractive candidate for the next generation of hot electron bolometers with greatly improved sensitivity.

Wen, B.; Yakobov, R.; Vitkalov, S. A. [Department of Physics, City College of New York, New York 10031 (United States)] [Department of Physics, City College of New York, New York 10031 (United States); Sergeev, A. [SUNY Research Foundation, SUNY at Buffalo, Buffalo, New York 14226 (United States)] [SUNY Research Foundation, SUNY at Buffalo, Buffalo, New York 14226 (United States)

2013-11-25T23:59:59.000Z

278

Trapped-flux internal-dipole superconducting motor/generator.  

SciTech Connect (OSTI)

A new class of motor/generator (M/G) utilizes the magnetic flux trapping capability of high-temperature superconductors (HTSs). The rotor, consists of a cylindrical shell composed of HTS segments. These segments act as trapped-field magnets, magnetized in such a way that a dipole magnetic field is produced in the interior of the shell. A stator coil assembly is placed in the interior of the shell and current passing through the conductors of the coil produce a rotational torque, either as a hysteresis motor or as a synchronous motor. The coil may be either conventional, with copper wires and an iron core, or composed of superconductors and can be used to establish the trapped fields in the HTSs.

Hull, J. R.

1998-09-03T23:59:59.000Z

279

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network [OSTI]

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

Hassenzahl, W.

2011-01-01T23:59:59.000Z

280

AFRD - Superconducting Magnets  

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

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

Note: This page contains sample records for the topic "temperature superconducting hts" 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

Supercurrent in superconducting graphene  

Science Journals Connector (OSTI)

The problem of supercurrent in superconducting graphene is revisited and the supercurrent is calculated within the mean-field model employing the two-component wave functions on a honeycomb lattice with pairing between different valleys in the Brillouin zone. We show that the supercurrent within the linear approximation in the order-parameter-phase gradient is always finite even if the doping level is exactly zero.

N. B. Kopnin and E. B. Sonin

2010-07-13T23:59:59.000Z

282

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

283

10MW Class Direct Drive HTS Wind Turbine: Cooperative Research and Development Final Report, CRADA Number CRD-08-00312  

SciTech Connect (OSTI)

This paper summarizes the work completed under the CRADA between NREL and American Superconductor (AMSC). The CRADA combined NREL and AMSC resources to benchmark high temperature superconducting direct drive (HTSDD) generator technology by integrating the technologies into a conceptual wind turbine design, and comparing the design to geared drive and permanent magnet direct drive (PMDD) wind turbine configurations. Analysis was accomplished by upgrading the NREL Wind Turbine Design Cost and Scaling Model to represent geared and PMDD turbines at machine ratings up to 10 MW and then comparing cost and mass figures of AMSC's HTSDD wind turbine designs to theoretical geared and PMDD turbine designs at 3.1, 6, and 10 MW sizes.

Musial, W.

2011-05-01T23:59:59.000Z

284

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

285

SciTech Connect: Superconductivity  

Office of Scientific and Technical Information (OSTI)

English Subject: Condensed Matter Physics, Superconductivity & Superfluidity(75) Word Cloud More Like This Full Text File size NAView Full Text View Full Text DOI: 10.2172...

286

A worldwide overview of superconductivity development efforts for utility applications  

SciTech Connect (OSTI)

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

Giese, R.F.

1996-04-01T23:59:59.000Z

287

Fiber Bragg Grating Cryo-Sensors for Superconducting Accelerator Magnets  

E-Print Network [OSTI]

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

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

2014-01-01T23:59:59.000Z

288

Graphite and its Hidden Superconductivity | Stanford Synchrotron Radiation  

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

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

289

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

E-Print Network [OSTI]

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

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

2014-01-01T23:59:59.000Z

290

Prospects of High Temperature Superconductors for fusion magnets and power applications  

Science Journals Connector (OSTI)

Abstract During the last few years, progress in the field of second-generation High Temperature Superconductors (HTS) was breathtaking. Industry has taken up production of long length coated REBCO conductors with reduced angular dependency on external magnetic field and excellent critical current density jc. Consequently these REBCO tapes are used more and more in power application. For fusion magnets, high current conductors in the kA range are needed to limit the voltage during fast discharge. Several designs for high current cables using High Temperature Superconductors have been proposed. With the REBCO tape performance at hand, the prospects of fusion magnets based on such high current cables are promising. An operation at 4.5 K offers a comfortable temperature margin, more mechanical stability and the possibility to reach even higher fields compared to existing solutions with Nb3Sn which could be interesting with respect to DEMO. After a brief overview of HTS use in power application the paper will give an overview of possible use of HTS material for fusion application. Present high current HTS cable designs are reviewed and the potential using such concepts for future fusion magnets is discussed.

Walter H. Fietz; Christian Barth; Sandra Drotziger; Wilfried Goldacker; Reinhard Heller; Sonja I. Schlachter; Klaus-Peter Weiss

2013-01-01T23:59:59.000Z

291

Fabrication of superconducting wire using organometallic precursors and infiltration  

SciTech Connect (OSTI)

Organometallic precursors from naphthenic acid and metal nitrates were used for the synthesis of YBCO oxide superconducting compounds. The characteristics of metal naphthenates as organometallic precursors were investigated by IR spectra, viscosity measurements, and infiltration. 123 superconducting compound obtained from 123 naphthenate showed a Tc of 90{degree}K and a rather dense and elongated microstructure. Also, the melting behavior of Ba-cuprates which were used for 123 making was studied. A low-temperature melting process was developed to fabricate silver-sheathed superconducting wire with the powder-in-tube method; flowing argon gas is introduced to the system at 930-945{degree}C to reduce the melting temperature of the 123 compound without silver sheath melting. It resulted in a 90{degree}K Tc superconducting core with dense and locally aligned microstructure. SEM-EDS and XRD analysis, 4-probe resistance and Jc measurements, and carbon-content determinations were carried out to characterize the microstructure, grain alignment, and superconducting properties of the samples.

Lee, Y.J.

1991-01-01T23:59:59.000Z

292

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

E-Print Network [OSTI]

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

Maroncelli, Mark

293

Search for superconductivity of Ag/Ge(100) surface alloys with UHV-LT-STM/STS  

Science Journals Connector (OSTI)

We have been searching novel superconducting materials only at their surface regions using a homemade ultra high vacuum low temperature scanning tunneling microscope. We found that scanning tunneling current-v...

Ken Hattori; Takushi Iimori; Yoshihiro Takahashi…

1996-01-01T23:59:59.000Z

294

Super-conducting niobium films produced by means of UHV arc  

Science Journals Connector (OSTI)

The paper shows that high-quality super-conducting Nb films can be deposited by means of arc discharges under ultra-high vacuum conditions. The critical temperatureT c...of Nb-films obtained with ...

J. Langner; M. J. Sadowski; K. Czaus; R. Mirowski…

2004-03-01T23:59:59.000Z

295

Operation of a Wideband Terahertz Superconducting Bolometer Responding to Quantum Cascade Laser Pulses  

Science Journals Connector (OSTI)

We make use of a niobium film to produce a micrometric vacuum-bridge superconducting bolometer responding to THz frequency. The bolometer works anywhere in the temperature range 2–7 K, which can be easily reached...

S. Cibella; M. Beck; P. Carelli; M. G. Castellano…

2012-06-01T23:59:59.000Z

296

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

297

Superconductivity and Magnetism: Materials Properties  

E-Print Network [OSTI]

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

298

PASREG 2005: The 5th International Workshop on Processing and Applications of Superconducting (RE)BCO Large Grain Materials  

Science Journals Connector (OSTI)

Large grain, (RE)BCO bulk superconductors fabricated by top-seeded melt growth (TSMG) have outstanding potential for a variety of engineering applications such as magnetic separators, flywheel energy storage, magnetic bearings and permanent magnet-like devices due to their ability to generate large magnetic fields. Recent developments in materials and systems research has led to the manufacture of proto-type devices for use in magnetron sputtering, magnetic stirrers and a mobile magnetic separator based on bulk materials technology. This issue contains selected papers presented at the 5th International Workshop on the Processing and Applications of Superconducting (RE)BCO Large Grain Materials held on 21–23 October 2005 at Tokyo Marine University to report progress made in this field over the previous two years. The workshop followed those held previously in Cambridge, UK (1997), Morioka, Japan (1999), Seattle, USA (2001), and Jena, Germany (2003). A total of 76 papers were presented at this workshop, of which 27 were presented in oral form and 49 were presented as posters. This issue contains a total of 36 selected papers in the following categories of bulk (RE)BCO large grain material: processing, characterization, and applications. The editors are grateful for the support of many colleagues both within and outside the immediate bulk community who reviewed the manuscripts to guarantee their high technical quality. Finally, the attendees wish to acknowledge the efforts of Professor Mitsuru Izumi and his research staff from Tokyo Marine University for being generous hosts during the workshop, and the efforts of Professor Masato Murakami for the overall organization of the meeting. The International PASREG Board selected the following distinguished researchers as recipients of the 2005 PASREG Award of Excellence to acknowledge their contribution to the development of bulk high temperature superconductors: • Dr Michael Strasik (Boeing, Seattle, USA) • Dr Hiroshi Ikuta (Nagoya University, Japan) • Dr Pavel Diko (Institute for Experimental Physics, Kosice, Slovakia) The poster presentation awards were bestowed to: • S Haindl, F Hengstberger, H W Weber, L Shlyk, G Krabbes, N Hari Babu, D A Cardwell `Characterization of Melt Grown Bulk Superconductors by the Magnetoscan Technique' • K Zmorayova, M Sefeiiova, P Diko, H W Weber, G Krabbes `Quantitative Characterization of Oxygenation Cracks in TSMG YBCO Bulks' • I Ohtani, H Matsuzaki, Y Kimura, E Morita, M Izumi, T Ida, M Miki, M Kitano `Pulse-Field Magnetization of Bulk HTS in Twinned Rotor Assembly for Axial-type Machines' The 6th PASREG Workshop will be held in Houston, USA, in the summer of 2007.

Masato Murakami, David Cardwell, Kamel Salama and Mitsuru Izumi

2006-01-01T23:59:59.000Z

299

Method for obtaining large levitation pressure in superconducting magnetic bearings  

DOE Patents [OSTI]

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

Hull, J.R.

1997-08-05T23:59:59.000Z

300

Superconductivity Highlights | Neutron Science | ORNL  

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

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

Note: This page contains sample records for the topic "temperature superconducting hts" 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

DOE Superconductivity Program Stakeholders  

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

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

302

General trend for pressurized superconducting hydrogen-dense materials  

SciTech Connect (OSTI)

The long-standing prediction that hydrogen can assume a metallic state under high pressure, combined with arguments put forward more recently that this state might even be superconducting up to high temperatures, continues to spur tremendous research activities toward the experimental realization of metallic hydrogen. These efforts have however so far been impeded by the enormous challenges associated with the exceedingly large required pressure. Hydrogen-dense materials, of the MH{sub 4} form (where M can be, e.g., Si, Ge, or Sn) or of the MH{sub 3} form (with M being, e.g., Al, Sc, Y, or La), allow for the rather exciting opportunity to carry out a proxy study of metallic hydrogen and associated high-temperature superconductivity at pressures within the reach of current techniques. At least one experimental report indicates that a superconducting state might have been observed already in SiH{sub 4}, and several theoretical studies have predicted superconductivity in pressurized hydrogen-rich materials; however, no systematic dependence on the applied pressure has yet been identified so far. In the present work, we have used first-principles methods in an attempt to predict the superconducting critical temperature (T{sub c}) as a function of pressure (P) for three metal-hydride systems of the MH{sub 3} form, namely ScH{sub 3}, YH{sub 3}, and LaH{sub 3}. By comparing the obtained results, we are able to point out a general trend in the T{sub c}-dependence on P. These gained insights presented here are likely to stimulate further theoretical studies of metallic phases of hydrogen-dense materials and should lead to new experimental investigations of their superconducting properties.

Kim, D. Y.; Scheicher, R. H.; Mao, Ho-kwang; Kang, T. W.; Ahuja, R.

2010-01-01T23:59:59.000Z

303

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

304

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

305

Superconducting micronets: The Wheatstone bridge  

Science Journals Connector (OSTI)

Using the Ginzburg-Landau theory, a particular superconducting (sc) micronet, called the Wheatstone bridge, is studied. This planar micronet is made of two nodes connected by three thin sc wires. A magnetic field is applied perpendicularly to its plane. The sc-normal second-order phase transition is characterized by only two configurations of the order parameter: cphiA=cphiB and cphiA=-cphiB, where cphiA and cphiB are the order parameters at the nodes. For temperatures near Tc, we show that only the cphiA=cphiB configuration is admissible for fluxes near ?=n?0, where n is an integer and ?0 is the flux quantum. Finally, the exact solution of the nonlinear Ginzburg-Landau equations for one-dimensional systems is numerically fitted to the boundary conditions of the Wheatstone bridge for the two configurations cphiA=cphiB and cphiA=-?B. Graphs of the Gibbs energy and of the spontaneous supercurrent, which for these two configurations is always a screening supercurrent, are given as functions of the total flux. A discontinuous transition between configurations occurs as a function of the flux.

Christine Ammann; Paul Erdös; Stephen B. Haley

1995-05-01T23:59:59.000Z

306

Superconducting gamma and fast-neutron spectrometers with high energy resolution  

DOE Patents [OSTI]

Superconducting Gamma-ray and fast-neutron spectrometers with very high energy resolution operated at very low temperatures are provided. The sensor consists of a bulk absorber and a superconducting thermometer weakly coupled to a cold reservoir, and determines the energy of the incident particle from the rise in temperature upon absorption. A superconducting film operated at the transition between its superconducting and its normal state is used as the thermometer, and sensor operation at reservoir temperatures around 0.1 K reduces thermal fluctuations and thus enables very high energy resolution. Depending on the choice of absorber material, the spectrometer can be configured either as a Gamma-spectrometer or as a fast-neutron spectrometer.

Friedrich, Stephan (San Jose, CA); , Niedermayr, Thomas R. (Oakland, CA); Labov, Simon E. (Berkeley, CA)

2008-11-04T23:59:59.000Z

307

Structure and superconductivity of isotope-enriched boron-doped diamond  

SciTech Connect (OSTI)

Superconducting boron-doped diamond samples were synthesized with isotopes of {sup 10}B, {sup 11}B, {sup 13}C and {sup 12}C. We claim the presence of a carbon isotope effect on the superconducting transition temperature, which supports the 'diamond-carbon'-related nature of superconductivity and the importance of the electron-phonon interaction as the mechanism of superconductivity in diamond. Isotope substitution permits us to relate almost all bands in the Raman spectra of heavily boron-doped diamond to the vibrations of carbon atoms. The 500 cm{sup 01} Raman band shifts with either carbon or boron isotope substitution and may be associated with vibrations of paired or clustered boron. The absence of a superconducting transition (down to 1.6 K) in diamonds synthesized in the Co-C-B system at 1900 K correlates with the small boron concentration deduced from lattice parameters.

Thompson, Joe D [Los Alamos National Laboratory; Ekimov, E A [INSTIT OF HIGH PRESSURE; Sidorov, V A [INSTIT OF HIGH PRESSURE; Zoteev, A [MOSCOW SU; Lebed, Y [INST FOR NUCI RES; Stishov, S M [INST FOR HIGH PRESSURE

2008-01-01T23:59:59.000Z

308

Superconductive tunnel junction integrated circuit  

SciTech Connect (OSTI)

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

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

1984-02-07T23:59:59.000Z

309

Superconducting magnetic energy storage  

SciTech Connect (OSTI)

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

Hassenzahl, W.

1988-08-01T23:59:59.000Z

310

Superconducting energy storage  

SciTech Connect (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

311

Superconductivity and Physical Properties of CaPd2Ge2 Single Crystals  

SciTech Connect (OSTI)

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

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

2014-10-08T23:59:59.000Z

312

Brett Parker | Superconducting Magnet Division  

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

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

313

Mixed-mu superconducting bearings  

DOE Patents [OSTI]

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

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

1998-03-03T23:59:59.000Z

314

EIS-0138: Superconducting Super Collider  

Broader source: Energy.gov [DOE]

The U.S. Department of Energy developed this EIS to analyze the potential environmental impacts of constructing the Superconducting Super Collider, a large proton accelerator, at each of seven alternative locations.

315

Critical State of Superconducting Solenoids  

Science Journals Connector (OSTI)

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

M. S. Lubell

1966-01-01T23:59:59.000Z

316

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

317

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

318

Superconducting Magnet Technology for Future Hadron Colliders  

SciTech Connect (OSTI)

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

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

1994-10-01T23:59:59.000Z

319

High-Tc superconductivity in entirely end-bonded multi-walled carbon nanotubes  

E-Print Network [OSTI]

We report that entirely end-bonded multi-walled carbon nanotubes (MWNTs) can show superconductivity with the transition temperature Tc as high as 12K that is approximately 40-times larger than those reported in ropes of single-walled nanotubes. We find that emergence of this superconductivity is very sensitive to junction structures of Au electrode/MWNTs. This reveals that only MWNTs with optimal numbers of electrically activated shells, which are realized by the end-bonding, can allow the superconductivity due to inter shell effects.

I. Takesue; J. Haruyama; N. Kobayashi; S. Chiashi; S. Maruyama; T. Sugai; H. Shinohara

2005-12-16T23:59:59.000Z

320

The Astro-H high temperature superconductor lead assemblies  

Science Journals Connector (OSTI)

Abstract The Soft X-ray Spectrometer (SXS) instrument, one of several instruments on JAXA’s Astro-H mission, will observe diffuse X-ray sources with unparalleled spectral resolution using a microcalorimeter array operating at 50 mK. The array is cooled with a multi-stage Adiabatic Demagnetization Refrigerator mounted on a 40 l helium tank. The tank is at the center of a typical “shell in shell” cryostat, with the innermost shield cooled by a JT cryocooler, and successive outer shields cooled by stirling-cycle cryocoolers. To achieve a multi-year liquid helium lifetime and to avoid exceeding the limited capacity of the JT cooler, very strict requirements are placed on every source of heat leak into these surfaces from the higher temperature shields. However, each ADR stage draws a maximum of 2 A, and the Wiedemann–Franz Law precludes even an optimized set of normal-metal leads capable of such high current from achieving the required low thermal conductance. Instead, a set of lead assemblies have been developed based on narrow high temperature superconductor (HTS) tapes derived from commercially available coated conductors. Although the HTS tapes are flexible and have high tensile strength, they are extremely sensitive to damage through a number of mechanisms. A robust set of assemblies have been developed that provide mechanical support to the tapes, provide appropriate interfaces at either end, and yet still meet the challenging thermal requirements. An Engineering Model (EM) set of HTS lead assemblies have survived environmental testing, both as individual units and as part of the EM cryostat, and have performed without problem in recent operation of the EM instrument. The Flight Model (FM) HTS lead assemblies are currently nearing completion.

E.R. Canavan; B.L. James; T.P. Hait; A. Oliver; D.F. Sullivan

2014-01-01T23:59:59.000Z

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321

Superconductivity from Predominantly Repulsive Interactions in Quasi One-Dimensional Systems  

Science Journals Connector (OSTI)

We show that for a one-dimensional electron gas with strong repulsive electron-electron interactions and a weak retarded attractive interaction, superconducting fluctuations can occur at high temperatures. The dominant driving force for these fluctuations is the repulsive interactions! Although the results are for a one-dimensional model, a strong analogy exists between our results and the short-ranged resonating-valence-bond picture of superconductivity.

G. T. Zimanyi; S. A. Kivelson; A. Luther

1988-05-16T23:59:59.000Z

322

Stress dependent oxidation of sputtered niobium and effects on superconductivity  

SciTech Connect (OSTI)

We report on the suppression of room temperature oxidation of DC sputtered niobium films and the effects upon the superconductive transition temperature, T{sub c}. Niobium was sputter-deposited on silicon dioxide coated 150?mm wafers and permitted to oxidize at room temperature and pressure for up to two years. Resistivity and stress measurements indicate that tensile films greater than 400?MPa resist bulk oxidation with measurements using transmission electron microscope, electron dispersive X-ray spectroscopy, x-ray photoelectric spectroscopy, and secondary ion mass spectrometry confirming this result. Although a surface oxide, Nb{sub 2}O{sub 5}, consumed the top 6–10?nm, we measure less than 1 at. % oxygen and nitrogen in the bulk of the films after the oxidation period. T{sub c} measurements using a SQUID magnetometer indicate that the tensile films maintained a T{sub c} approaching the dirty superconductive limit of 8.4?K after two years of oxidation while maintaining room temperature sheet resistance. This work demonstrates that control over niobium film stress during deposition can prevent bulk oxidation by limiting the vertical grain boundaries ability to oxidize, prolonging the superconductive properties of sputtered niobium when exposed to atmosphere.

David Henry, M., E-mail: mdhenry@sandia.gov; Wolfley, Steve; Monson, Todd; Clark, Blythe G.; Shaner, Eric; Jarecki, Robert [Sandia National Labs, MESA Fabrication Facility PO Box 5800 MS 1084, Albuquerque, New Mexico 87185-1084 (United States)

2014-02-28T23:59:59.000Z

323

Superconducting digital logic amplifier  

SciTech Connect (OSTI)

This paper describes a superconducting digital logic amplifier for interfacing between a Josephson junction logic circuit having output current and a higher voltage semiconductor circuit input. The amplifier comprising: an input terminal for connection to a ; an output terminal for connection to a semiconductor circuit input; an input, lower critical current, Josephson junction having first and second terminals; a first series string of at least three lower critical current Josephson junctions. The first series string being connected to the first terminal of the input Josephson junction such that the first series string is in series with the input Josephson junction to provide a series combination. The input terminal being connected to the first terminal of the input Josephson junction, and with the critical current of the lower critical current Josephson junctions of the input Josephson junction and the first series Josephson junctions being less than the output current of the low voltage Josephson junction circuit; a second series string of at least four higher critical current Josephson junctions. The second string being connected in parallel with the series combination to provide parallel strings having an upper common connection and a lower common connection. The lower common connection being connected to the second terminal of the input Josephson junction and the upper common connection being connected to the output terminal; and a pulsed DC current source connected the parallel strings at the upper common connection. The DC current source having a current at least equal to the critical current of the higher critical current Josephson junctions.

Przybysz, J.X.

1989-08-22T23:59:59.000Z

324

Development of Superconducting AC Fault Current Limiter  

Science Journals Connector (OSTI)

The authors have developed a new superconducting fault current limiter whose impedance during normal operation is very small. During fault conditions, the limiter behaves as a superconducting reactor. The limiter

Daisuke Ito; Eriko Yoneda; Tsutomu Fujioka…

1990-01-01T23:59:59.000Z

325

Test on Superconducting AC Fault Current Limiter  

Science Journals Connector (OSTI)

The authors have developed a new superconducting fault current limiter whose impedance during normal operation is very small. During fault conditions, the limiter behaves as a superconducting reactor. The limiter

Daisuke Ito; Eriko S. Yoneda…

1990-01-01T23:59:59.000Z

326

Simulating weak localization using superconducting quantum circuits  

E-Print Network [OSTI]

Understanding complex quantum matter presents a central challenge in condensed matter physics. The difficulty lies in the exponential scaling of the Hilbert space with the system size, making solutions intractable for both analytical and conventional numerical methods. As originally envisioned by Richard Feynman, this class of problems can be tackled using controllable quantum simulators. Despite many efforts, building an quantum emulator capable of solving generic quantum problems remains an outstanding challenge, as this involves controlling a large number of quantum elements. Here, employing a multi-element superconducting quantum circuit and manipulating a single microwave photon, we demonstrate that we can simulate the weak localization phenomenon observed in mesoscopic systems. By engineering the control sequence in our emulator circuit, we are also able to reproduce the well-known temperature dependence of weak localization. Furthermore, we can use our circuit to continuously tune the level of disorder, a parameter that is not readily accessible in mesoscopic systems. By demonstrating a high level of control and complexity, our experiment shows the potential for superconducting quantum circuits to realize scalable quantum simulators.

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

2014-03-26T23:59:59.000Z

327

Superconductivity in SrNi2P2 single crystals  

SciTech Connect (OSTI)

Heat capacity, magnetic susceptibility, and resistivity of SrNi{sub 2}P{sub 2} single crystals are presented, illustrating the structural transition at 325 K, and bulk superconductivity at 1.4 K. The magnitude of {Tc}, fits to the heat capacity data, the small upper critical field H{sub c2} = 390 Oe, and {kappa} = 2.1 suggests a conventional fully gapped superconductor. With applied pressure we find that superconductivity persists into the so-called 'collapsed tetragonal' phase, although the transition temperature is monotonically suppressed with increasing pressure. This argues that reduced dimensionality can be a mechanism for increasing the transition temperatures of layered NiP, as well as layered FeAs and NiAs, superconductors.

Ronning, Filip [Los Alamos National Laboratory; Bauer, Eric D [Los Alamos National Laboratory; Park, Tuscon [Los Alamos National Laboratory; Thompson, Joe D [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

328

Enhanced superconducting pairing interaction in indium-doped tin telluride  

SciTech Connect (OSTI)

The ferroelectric degenerate semiconductor Sn{sub 1-{delta}}Te exhibits superconductivity with critical temperatures, T{sub c}, of up to 0.3 K for hole densities of order 10{sup 21} cm{sup -3}. When doped on the tin site with greater than x{sub c} = 1.7(3)% indium atoms, however, superconductivity is observed up to 2 K, though the carrier density does not change significantly. We present specific heat data showing that a stronger pairing interaction is present for x > x{sub c} than for x < x{sub c}. By examining the effect of In dopant atoms on both T{sub c} and the temperature of the ferroelectric structural phase transition, T{sub SPT}, we show that phonon modes related to this transition are not responsible for this T{sub c} enhancement, and discuss a plausible candidate based on the unique properties of the indium impurities.

Erickson, A.S.

2010-05-03T23:59:59.000Z

329

Enhanced superconducting pairing interaction in indium-doped tin telluride  

SciTech Connect (OSTI)

The ferroelectric degenerate semiconductor Sn{sub 1-{delta}}Te exhibits superconductivity with critical temperatures, T{sub c}, of up to 0.3 K for hole densities of order 10{sup 21} cm{sup -3}. When doped on the tin site with greater than x{sub c} = 1.7(3)% indium atoms, however, superconductivity is observed up to 2 K, though the carrier density does not change significantly. We present specific heat data showing that a stronger pairing interaction is present for x > x{sub c} than for x < x{sub c}. By examining the effect of In dopant atoms on both T{sub c} and the temperature of the ferroelectric structural phase transition, T{sub SPT}, we show that phonon modes related to this transition are not responsible for this T{sub c} enhancement, and discuss a plausible candidate based on the unique properties of the indium impurities.

Erickson, A.S.; Chu, J.-H.; /Stanford U., Appl. Phys. Dept. /Stanford U., Geballe Lab.; Toney, M.F.; Geballe, T.H.; Fisher, I.R.; /SLAC, SSRL /Stanford U., Appl. Phys. Dept. /Stanford U., Geballe Lab.

2010-02-15T23:59:59.000Z

330

Superconducting Topological Fluids in Josephson Junction Arrays  

E-Print Network [OSTI]

We argue that the frustrated Josephson junction arrays may support a topologically ordered superconducting ground state, characterized by a non-trivial ground state degeneracy on the torus. This superconducting quantum fluid provides an explicit example of a system in which superconductivity arises from a topological mechanism rather than from the usual Landau-Ginzburg mechanism.

M. Cristina Diamantini; Pasquale Sodano; Carlo A. Trugenberger

2006-04-21T23:59:59.000Z

331

Superconductivity up to 114 K in the Bi-Al-Ca-Sr-Cu-O compound system without rare-earth elements  

Science Journals Connector (OSTI)

Stable superconductivity up to 114 K has been reproducibly detected in Bi-Al-Ca-Sr-Cu-O multiphase systems without any rare-earth elements. Pressure has only a slight positive effect on Tc. These observations provide an extra material base for the study of the mechanism of high-temperature superconductivity and also the prospect of reduced material cost for future applications of superconductivity.

C. W. Chu; J. Bechtold; L. Gao; P. H. Hor; Z. J. Huang; R. L. Meng; Y. Y. Sun; Y. Q. Wang; Y. Y. Xue

1988-03-07T23:59:59.000Z

332

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

SciTech Connect (OSTI)

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

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

1984-08-01T23:59:59.000Z

333

Ferrimagnetic Spin Wave Resonance and Superconductivity in Carbon Nanotubes  

E-Print Network [OSTI]

The phenomenon of ferrimagnetic spin wave resonance [uncompensated antiferromagnetic spin wave resonance] has been detected for the first time. It has been observed in carbon nanotubes, produced by high energy ion beam modification of diamond single crystals in $\\ $ direction. Peculiarities of spin wave resonance observed allow to insist on the formation in given nanotubes of $s^+$ superconductivity at room temperature, coexisting with uncompensated antiferromagnetic ordering.

Yerchuck, Dmitri; Stelmakh, Vyacheslav; Dovlatova, Alla; Alexandrov, Andrey

2013-01-01T23:59:59.000Z

334

Photo of the Week: How to Grow Superconducting Crystals | Department of  

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

How to Grow Superconducting Crystals How to Grow Superconducting Crystals Photo of the Week: How to Grow Superconducting Crystals September 13, 2013 - 11:29am Addthis Many of the materials that scientists work with at Brookhaven National Laboratory are too small and too precise for traditional tools. In cases like these, the labs grow materials instead of building them. Brookhaven physicist Genda Gu pioneered techniques that grow some of the largest single-crystal high-temperature superconductors in the world. The glowing chamber in this photo grows superconducting crystals. To do so, the furnace focuses infrared light onto a rod, melting it around 4,000 degrees Fahrenheit. Under just the right conditions, the liquefied material recrystallizes as a single uniform structure, which is highly sensitive and takes about one month to form. | Photo courtesy of Brookhaven National Laboratory.

335

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

336

Dynamical properties of superconducting nanowires  

SciTech Connect (OSTI)

The dynamical properties of thin superconducting wires (nanowires) are studied using numerical simulations based on a one-dimensional time-dependent Ginzburg-Landau equation, which is modified by introducing an order parameter u characterizing the 'purity' of the superconductor material. It is established that relatively long nanowires (with lengths much greater than the coherence length) made of a 'pure' superconductor (u > 1) are characterized by two critical current density values: j{sub c1} and j{sub c2}. For j < j{sub c1}, the total current is entirely superconducting, whereas for j > j{sub c2}, the current is purely normal. In the intermediate region of current densities, j{sub c1} < j < j{sub c2}, the total current contains both superconducting and normal components (mixed state) and the nanowire exhibits the generation of high-frequency electromagnetic waves. The current-voltage characteristics are constructed and the radiation spectrum is obtained. The properties of short superconducting nanowires (with lengths on the order of the coherence length) coincide with those of the Josephson junction. In the case of an 'impure' superconductor (u < 1), the nanowire is characterized by a single critical current density.

Nikolaev, S. V.; Yugay, K. N. [Omsk State University (Russian Federation)], E-mail: yugay_klimenty@mail.ru

2006-02-15T23:59:59.000Z

337

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

338

Superconductivity at 28?K in CaB{sub 3}C{sub 3} predicted from first-principles  

SciTech Connect (OSTI)

The structural parameters, electronic properties, and superconducting state in the graphite-like B{sub x}C{sub 1?x} intercalation compound, CaB{sub 3}C{sub 3}, have been studied using pseudopotential density functional theory within the generalized gradient approximation. Electronic and electron–phonon coupling calculations reveal that CaB{sub 3}C{sub 3} is hole conducting and superconducting with critical temperature 28.2?K, which is much higher than that of CaC{sub 6} (11.5?K). The excellent superconducting state in CaB{sub 3}C{sub 3} stems from the simultaneous presence of highly mobile and extremely confined conduction electrons, which enhances electron pairing and superconductivity. The current calculations might stimulate further theoretical and experimental investigation in search of new superconducting states in graphite-like B{sub x}C{sub 1?x} intercalated compounds.

Chen, Wanjin, E-mail: chenwwjj@gmail.com, E-mail: chenwwjj@126.com [College of Physics, Jilin Normal University, Siping 136000 (China)

2013-11-07T23:59:59.000Z

339

Superconductivity of Americium  

Science Journals Connector (OSTI)

...refrigerator capable of temper-atures from above 4 K to below 11 mK when operated without radioactive sam-ples. In this system...molecule should provide an ex-cellent tracer for determining at an ultra-structural level the distribution within tWh 'ell of a number...

JAMES L. SMITH; RICHARD G. HAIRE

1978-05-05T23:59:59.000Z

340

seshadri@mrl Superconductivity  

E-Print Network [OSTI]

Onnes at the University of Leiden in the Netherlands, 1908 "How happy I was to be able to show Onnes at the University of Leiden in the Netherlands, 1908 H. Kamerlingh Onnes, Investigations of helium, big science, Physics Today March 2008, page 26. #12;seshadri@mrl Very low temperatures 5: How

Akhmedov, Azer

Note: This page contains sample records for the topic "temperature superconducting hts" 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

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

E-Print Network [OSTI]

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

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

2015-01-14T23:59:59.000Z

342

Theory of High-T{sub c} Superconducting Cuprates Based on Experimental Evidence  

DOE R&D Accomplishments [OSTI]

A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons plus a small short-range repulsion of Hund's, or spin-fluctuation, origin. This permits to explain the large values of T{sub c}, features of the isotope effect on oxygen and copper, the existence of two types of the order parameter, the peak in the inelastic neutron scattering, the positive curvature of the upper critical field, as function of temperature etc.

Abrikosov, A. A.

1999-12-10T23:59:59.000Z

343

Gulyaev–Bleustein Waves in a Layered Structure of Piezoelectric – Periodic Granular High-Temperature Superconductor Structure  

Science Journals Connector (OSTI)

Bragg's interactions of Gulyaev–Bleustein surface waves with a periodic granular high-temperature superconducting medium are studied. Dispersion equations describing the characteristics of surface acoustoelect...

V. A. Krakovskii

2001-06-01T23:59:59.000Z

344

e Lens Solenoid | Superconducting Magnet Division  

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

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

345

Superconducting Cable Having A Felexible Former  

DOE Patents [OSTI]

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

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

2005-03-15T23:59:59.000Z

346

Superconducting Cable Having A Flexible Former  

DOE Patents [OSTI]

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

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

2005-08-30T23:59:59.000Z

347

OSTI, US Dept of Energy, Office of Scientific and Technical Information |  

Office of Scientific and Technical Information (OSTI)

Brookhaven Topic Brookhaven Topic Solving the mystery of superconductivity by Kathy Chambers 17 Oct, 2013 in Products and Content Brookhaven physicist Yong Chu at the National Synchrotron Light Source II looks At the legendary 1987 American Physical Society conference, sometimes called the "Woodstock of physics", thousands of physicists descended upon a New York Hilton ballroom to hear about the discovery of high-temperature superconductivity (HTS) in ceramic materials. Related Topics: Brookhaven, HTS, National Synchrotron Light Source II, OSTI Homepage, superconductivity, X-Ray Nanoprobe Read more... Travel through DOE databases; find emerging nanotechnology devices by Kathy Chambers 16 Jul, 2012 in Technology Quantum dots - small semiconducting nanocrystals (Image: ANL)

348

Nonlinear Electrodynamics of Superconducting Films  

Science Journals Connector (OSTI)

Microwave-transmission measurements at 9.4 Gc/sec over a wide range of incident power have been used to study the nonlinear electrodynamics of thin superconducting films. By measuring the amplitude and phase of the fundamental transmitted field, the contributions of superelectrons and normal electrons to the electrodynamics of the films have been determined. In low microwave fields the nonlinear behavior of the films can be attributed to the breakup of superconducting pairs in agreement with the Ginzberg-Landau theory. In high microwave fields, regions of normal resistance appear through which a dc bias current cannot avoid passing. Most of the third-harmonic power is generated by these resistive regions.

K. Rose and M. D. Sherrill

1966-05-06T23:59:59.000Z

349

Friction domination with superconducting strings  

Science Journals Connector (OSTI)

We investigate the evolution of a superconducting string network with arbitrary, constant string current in the friction dominated regime. In the absence of an external magnetic field the network always reaches a scaling solution. However, for string current stronger than a critical value, it is different than the usual horizon scaling of the nonsuperconducting string case. In this case the friction domination era never ends. Whilst the superconducting string network can be much denser than usually assumed, it can never dominate the universe energy density. It can, however, influence the cosmic microwave background radiation and the formation of large scale structure. When embedded in a primordial magnetic field of sufficient strength, the network never reaches scaling and, thus, eventually dominates the universe evolution.

Konstantinos Dimopoulos and Anne-Christine Davis

1998-01-15T23:59:59.000Z

350

Coherence effects in hole superconductivity  

Science Journals Connector (OSTI)

We discuss the behavior of various observables that depend on matrix elements of operators in the superconducting state within the model of hole superconductivity. In this model, the gap exhibits a linear dependence on the band energy, and the bandwidth depends on the carrier concentration and can become very small for low hole density. We study, in particular, the behavior of ultrasonic attenuation, NMR relaxation rate, and electromagnetic absorption, and present results for parameters expected to be in the range that describes the high-Tc oxides. It is found that the energy dependence of the gap does not give rise to qualitatively different behavior, but significant differences from weak-coupling BCS behavior occur at low hole concentration due to the extreme narrowness of the band.

F. Marsiglio and J. E. Hirsch

1991-12-01T23:59:59.000Z

351

Static forces in a superconducting magnet bearing  

SciTech Connect (OSTI)

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

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

1995-11-01T23:59:59.000Z

352

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

SciTech Connect (OSTI)

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

Beal-Monod, M. T.

1989-06-01T23:59:59.000Z

353

Superconducting inductive displacement detection of a microcantilever  

E-Print Network [OSTI]

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

Andrea Vinante

2014-05-14T23:59:59.000Z

354

National High Magnetic Field Laboratory - Applied Superconductivity...  

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

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

355

National High Magnetic Field Laboratory - Applied Superconductivity...  

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

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

356

Testing gravitational physics with superconducting gravimeters  

E-Print Network [OSTI]

Superconducting gravimeters are the most sensitive instruments to measure surface gravity changes at low frequencies. Currently, about twenty five superconducting gravimeters are operating in the world and their global network has been developed. We investigate possible applications of the superconducting gravimeters to tests of gravitational physics. Previous experimental searches for spatial anisotropies in the gravitational constant G and for gravitational waves, performed with gravimeters in 1960's to 1970's, can be improved by applications of the current superconducting gravimeters. Also, we describe other proposed applications of testing the universality of free-fall and searching for composition-dependent dilatonic waves, and discuss future works necessary for these geophysical tests.

Sachie Shiomi

2009-02-24T23:59:59.000Z

357

Summary of Superconducting Fault Current Limiter Technology  

Science Journals Connector (OSTI)

In recent years, superconducting fault current limiter (SFCL) has become one of the forefront topics of current-limiting technology in the world. In this...

Linmang Wang; Pengzan Jiang; Dada Wang

2012-01-01T23:59:59.000Z

358

Fermilab | Science | Particle Accelerators | Advanced Superconducting...  

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

Superconducting Test Accelerator is America's only test bed for cutting-edge particle beams and for accelerator research aimed at Intensity Frontier proton accelerators. ASTA...

359

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

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

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

360

Study of Superconducting Fault Current Limiter Using Saturated Magnetic Core  

Science Journals Connector (OSTI)

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

F. Fajoni; E. Ruppert; C. A. Baldan…

2014-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

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

362

Magnetism and superconductivity observed to exist in harmony  

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

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

363

At the Frontiers of Science Superconductivity and Its Electric Power Applications  

SciTech Connect (OSTI)

Electricity - it is one of our modern scientific miracles, and today we could not imagine living without it. But what if we could make it better? Superconductivity has the potential to do just that, by improving the capacity, quality, and reliability of products that use electricity. There has been a great deal of discussion about superconductivity in the last 10 years, but what exactly is it? In this document you will learn the definition of superconductivity, how it works, and its present and potential uses. You will also get an inside look at the challenges that scientists around the world are working to overcome in order to fully incorporate superconductivity in our everyday lives. When you turn on a lamp at home, the electric current flows - is conducted - through a wire made of copper or aluminum. Along the way, this wire resists the flow of electricity, and this resistance is something very much like friction. The resistance causes some of the electricity to be lost in the form of heat. Which means that every time you use an appliance, from a radio to a generator, you are not getting 100% of the energy that flows through it; some of it is wasted by the conductor. Superconductivity - the ability of a material to conduct electricity without losses to resistance - is a physical property inherent to a variety of metals and ceramics, much the same way magnetism is present in a variety of materials. It is dependent on temperature; that is, a material will not exhibit superconductivity until it is sufficiently cold. The necessary temperatures to induce superconductivity are well below what we might commonly consider 'cold.' They are so low, in fact, that they are measured using the Kelvin temperature scale (K). Absolute zero, or 0 K, is equal to -459 Fahrenheit (F). It is defined as the lowest temperature theoretically possible, or the complete absence of heat. In 1911, working in a laboratory in Holland, the Dutch scientist Heike Kamerlingh Onnes cooled mercury to 4 K (-452 F), almost absolute zero; at this temperature, the motion of individual atoms nearly ceased. Scientists were unsure what effect this extremely low temperature would have on resistance; most suspected resistance would increase as atomic motion slowed. However, during routine measurements of the mercury, it appeared that there was no electrical resistance. Onnes assumed his equipment was broken, but days later he confirmed that, near absolute zero, mercury did completely lose electrical resistance. Onnes had discovered superconductivity.

None

1998-07-01T23:59:59.000Z

364

Long, Highly-Ordered High-Temperature Superconductor Nanowire Arrays  

Science Journals Connector (OSTI)

Long, Highly-Ordered High-Temperature Superconductor Nanowire Arrays ... For bulk superconductors, the electrical resistance drops precipitously to zero below the superconducting transition temperature (Tc). ... Even these temperatures are considerably higher than those found in conventional superconductor NWs of similar widths, which are typically below liquid helium temperature (4.2 K). ...

Ke Xu; James R. Heath

2008-10-28T23:59:59.000Z

365

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

E-Print Network [OSTI]

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

Zocco, Diego Andrés

2011-01-01T23:59:59.000Z

366

Electronic properties of doped Mott insulators and high temperature superconductors  

E-Print Network [OSTI]

High-temperature superconducting cuprates, which are the quintessential example of a strongly correlated system and the most extensively studied materials after semiconductors, spurred the development in the fields of ...

Ribeiro, Tiago Castro

2005-01-01T23:59:59.000Z

367

QED3 Theory of High Temperature Superconductors  

E-Print Network [OSTI]

QED3 Theory of High Temperature Superconductors Zlatko Tesanovi´c The Johns Hopkins University is The Problem in high Tc superconductors? · Superconducting state appears dx2-y2 "BCS-like". Low energy: · Today, everything seems to be a high temperature superconduc- tor (cuprates, C60's, MgB2

Tesanovic, Zlatko

368

Superconducting hot-electron nanobolometer with microwave bias and readout  

E-Print Network [OSTI]

We propose a new detection technique based on radio-frequency (RF) bias and readout of an antenna-coupled superconducting nanobolometer. This approach is suitable for Frequency-Division-Multiplexing (FDM) readout of large arrays using broadband low-noise RF amplifier. We call this new detector RFTES. This feasibility study was made on demonstrator devices which are made in all-Nb technology and operate at 4.2 K. The studied RFTES devices consist of an antenna-coupled superconducting nanobolometer made of ultrathin niobium films with transition temperature Tc = 5.2 K. The 0.65-THz antenna and nanobolometer are embedded as a load into a GHz-range coplanar niobium resonator (Tc = 8.9 K, Q = 4000). To heat the superconducting Nb nanobolometer close to the Tc, the RF power at resonator frequency f = 5.8 GHz is applied via a transmission line which is weakly coupled (-11 dB) to the loaded resonator. The THz-antenna of RFTES was placed in the focus of a sapphire immersion lens inside a He4-cryostat equipped with an ...

Kuzmin, A A; Shitov, S V; Abramov, N N; Ermakov, A B; Arndt, M; Wuensch, S H; Ilin, K S; Ustinov, A V; Siegel, M

2014-01-01T23:59:59.000Z

369

Imaging the two gaps of the high temperature superconductor Pb-Bi?Sr?CuO??x  

E-Print Network [OSTI]

The nature and behavior of electronic states in high temperature superconductors are the center of much debate. The pseudogap state, observed above the superconducting transition temperature Tc, is seen by some as a precursor ...

Yi, Ming, S.M. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

370

Quantum logic gates for superconducting resonator qudits  

SciTech Connect (OSTI)

We study quantum information processing using superpositions of Fock states in superconducting resonators as quantum d-level systems (qudits). A universal set of single and coupled logic gates is theoretically proposed for resonators coupled by superconducting circuits of Josephson junctions. These gates use experimentally demonstrated interactions and provide an attractive route to quantum information processing using harmonic oscillator modes.

Strauch, Frederick W. [Williams College, Williamstown, Massachusetts 01267 (United States)

2011-11-15T23:59:59.000Z

371

Cellulose-Bound Magnesium Diboride Superconductivity  

E-Print Network [OSTI]

Cellulose-Bound Magnesium Diboride Superconductivity Y.L. Lin and M.O. Pekguleryuz Department Canada Abstract--Two-phase superconductor tapes were produced by blending high purity magnesium diboride junctions. I. INTRODUCTION Magnesium diboride was found to be superconducting in 2001 by Nagamatsu et al. [1

Ryan, Dominic

372

Microcalorimeter Magnetic Sensor Geometries Using Superconducting Elements  

SciTech Connect (OSTI)

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

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

2009-12-16T23:59:59.000Z

373

Cryogenic structural materials for superconducting magnets  

SciTech Connect (OSTI)

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

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

1985-02-22T23:59:59.000Z

374

Electron-phonon interactions and superconductivity in Si, Ge, and Sn  

Science Journals Connector (OSTI)

The pseudopotential-total-energy method is used to calculate the phonon frequency, the electron density of states at the Fermi level, and the electron-phonon coupling constant for the group-IV elements in the metallic ?-Sn structure. For these elements, the normal-state behavior is similar to that found in other simple and transition metals; the phonon frequencies, force constants, and electron-phonon matrix elements increase with increasing average electron density. With use of a semiempirical treatment of the electron-phonon coupling calculated for one phonon wave vector, the superconducting transition temperatures at normal and high pressures are examined. The superconducting transition temperature decreases while the magnitude of its pressure coefficient increases in going to heavier elements. This behavior is in good agreement with experiment. For Si and Ge, the superconducting behavior is similar to that of white tin. Because of competition and compensation between the cutoff in the phonon spectrum and the electron-phonon matrix element, the electron-phonon coupling ?’s are similar for the three elements. Hence, the Debye temperature, which is the prefactor of the McMillan equation, dominates in determining the superconducting critical temperatures.

K. J. Chang and Marvin L. Cohen

1986-10-01T23:59:59.000Z

375

Hard superconducting nitrides Xiao-Jia Chen*, Viktor V. Struzhkin*, Zhigang Wu*, Maddury Somayazulu  

E-Print Network [OSTI]

(4). The refractory characteristics of these transition- metal nitrides and carbides have been, and hardness of selected superconducting transition-metal nitrides reveals inter- esting correlations among transition temperature (Tc) near 4 K when doped with boron (3). However, the transition-metal compounds

Wu, Zhigang

376

Type-1.5 Superconductivity  

Science Journals Connector (OSTI)

We demonstrate the existence of a novel superconducting state in high quality two-component MgB2 single crystalline superconductors where a unique combination of both type-1 (?1/?11/2) superconductor conditions is realized for the two components of the order parameter. This condition leads to a vortex-vortex interaction attractive at long distances and repulsive at short distances, which stabilizes unconventional stripe- and gossamerlike vortex patterns that we have visualized in this type-1.5 superconductor using Bitter decoration and also reproduced in numerical simulations.

Victor Moshchalkov; Mariela Menghini; T. Nishio; Q. H. Chen; A. V. Silhanek; V. H. Dao; L. F. Chibotaru; N. D. Zhigadlo; J. Karpinski

2009-03-16T23:59:59.000Z

377

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

378

U.S. Department of Energy and SuperPower, Inc. Increase Energy Efficiency  

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

and SuperPower, Inc. Increase Energy and SuperPower, Inc. Increase Energy Efficiency in the Nation's Electric Grid U.S. Department of Energy and SuperPower, Inc. Increase Energy Efficiency in the Nation's Electric Grid February 21, 2008 - 11:29am Addthis $27 Million Project Demonstrates Advanced Superconductivity Technology ALBANY, NY- The U.S. Department of Energy (DOE) and SuperPower, Inc. today commemorated the Albany High-Temperature Superconducting (HTS) Cable Project, the world's first use of second-generation HTS wire on the grid. This 350-meter HTS cable runs between the Riverside and Menands Substations in Albany, New York. HTS cables encounter essentially no resistance in electricity flow, which increases efficiency by eliminating 7-10 percent of the energy losses of conventional copper-based cables. DOE's over $13.5

379

U.S. Department of Energy and SuperPower, Inc. Increase Energy Efficiency  

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

Department of Energy and SuperPower, Inc. Increase Energy Department of Energy and SuperPower, Inc. Increase Energy Efficiency in the Nation's Electric Grid U.S. Department of Energy and SuperPower, Inc. Increase Energy Efficiency in the Nation's Electric Grid February 21, 2008 - 11:46am Addthis $27 Million Project Demonstrates Advanced Superconductivity Technology ALBANY, NY- The U.S. Department of Energy (DOE) and SuperPower, Inc. today commemorated the Albany High-Temperature Superconducting (HTS) Cable Project, the world's first use of second-generation HTS wire on the grid. This 350-meter HTS cable runs between the Riverside and Menands Substations in Albany, New York. HTS cables encounter essentially no resistance in electricity flow, which increases efficiency by eliminating 7-10 percent of the energy losses of conventional copper-based cables. DOE's over $13.5

380

Process for producing Nb/sub 3/Sn superconducting wires  

SciTech Connect (OSTI)

A process for producing a Nb/sub 3/Sn superconducting wire, which comprises preparing a composite from a copper alloy material containing 0.1 to 5 atomic percent in total of at least one element of Group IV of the periodic table selected from titanium, zirconium and hafnium, a tin material and a niobium material, processing the composite into a wire, tape or tube, and heat-treating the processed composite at a temperature of 400/sup 0/ to 900/sup 0/ C. to form a Nb/sub 3/Sn compound.

Tachikawa, K.; Yoshida, S.

1984-03-06T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

Broadband calibrated scattering parameters characterization of a superconducting quantum interference device amplifier  

SciTech Connect (OSTI)

In this work, we characterize the 2-port scattering parameters of a superconducting quantum interference device amplifier at {approx}20 mK over several gigahertz of bandwidth. The measurement reference plane is positioned on a 6.25 {Omega} microstrip line situated directly at the input and output of the device by means of a thru-reflect-line cryogenic calibration procedure. From the scattering parameters, we derive the device available power gain, isolation, and input impedance over the 2-8 GHz range. This measurement methodology provides a path towards designing wide-band matching circuits for low impedance superconducting amplifiers operating at dilution refrigerator temperatures.

Ranzani, Leonardo [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); University of Colorado at Boulder, Boulder, Colorado 80309 (United States); Spietz, Lafe; Aumentado, Jose [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

2013-07-08T23:59:59.000Z

382

Response of radio frequency superconducting quantum interference devices to electromagnetic interference  

SciTech Connect (OSTI)

A number of applications of high-temperature superconductor radio frequency superconducting quantum interference devices (rf SQUIDs) require a certain immunity of these sensors against electromagnetic interference (EMI). We have investigated effects of electromagnetic radiation in the high-frequency and ultrahigh-frequency range on various types of rf SQUIDs. It has been found that EMI of sufficient field strength reduces the voltage versus flux transfer function, and thus increases the flux noise of the SQUIDs. SQUIDs with a wire wound tank circuit coil have been found to be more sensitive to EMI than SQUIDs integrated into a superconducting microstrip resonator. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Mueck, M.; Dechert, J.; Gail, J.; Kreutzbruck, M.; Schoene, S.; Weidl, R. [Institut fuer Angewandte Physik, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)] [Institut fuer Angewandte Physik, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)

1995-09-01T23:59:59.000Z

383

Superconductivity above 20 K in the Ba-K-Bi-O system  

Science Journals Connector (OSTI)

The results of magnetic susceptibility measurements on multiphase Ba-K-Bi-O samples with overall composition Ba0.9KxBiO3 (x?0.2) provide evidence for superconductivity above 20 K in a minority fraction (?5%) of the sample volume. These results support the expectation that K doping at the inactive Ba donor sites can extend the metallic range of the previously studied BaPb1-xBixO3 alloys closer to the BaBiO3 Peierls instability where the strong coupling of the conduction electrons to the O phonons could explain the enhanced (Tc?22 vs 13 K) superconducting transition temperatures.

L. F. Mattheiss; E. M. Gyorgy; D. W. Johnson; Jr.

1988-03-01T23:59:59.000Z

384

Measuring Hawking Radiation of a Kerr-Newman Black Hole in a Superconducting Transmission Line  

E-Print Network [OSTI]

Applying a dimensional reduction technique and a coordinates transformation approach, we deduce the Kerr-Newman space-time into a Painlev\\'{e}-like form, and obtain its corresponding event horizon and the Hawking radiation temperature. We find that, the event horizon of a Kerr-Newman black hole can be simulated in a superconducting transmission line. Moreover, by running some numerical simulation, we confirm that the Hawking radiation of a Kerr-Newman Black Hole can be experimentally measured in a superconducting transmission line.

X. G. Lan; D. Y. Chen; L. F. Wei

2014-01-15T23:59:59.000Z

385

Pressure increase of the electron-phonon interaction in superconducting hexagonal silicon  

Science Journals Connector (OSTI)

Using an ab initio pseudopotential approach, the pressure dependence of the electron-phonon interaction parameter ? and the phonon frequencies for metallic hexagonal phases of silicon is calculated. With changing pressure ? is found to go first through a minimum and then reach its maximum value near the phase transition from simple hexagonal (sh) to hexagonal close packed (hcp). At this point the superconducting transition temperature Tc is expected to be above 10 K. In the hcp phase Si is predicted to be superconducting with Tc in the same range as in the sh phase.

Michel M. Dacorogna; K. J. Chang; Marvin L. Cohen

1985-08-01T23:59:59.000Z

386

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

SciTech Connect (OSTI)

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

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

2008-01-01T23:59:59.000Z

387

The LHC Superconducting RF System  

E-Print Network [OSTI]

The European Laboratory for Particle Physics (CERN), the largest high energy physics laboratory worldwide, is constructing the Large Hadron Collider (LHC) in the existing 27 km circumference LEP (Large Electron Positron) collider tunnel. For the LHC, superconducting cavities, operating at 4.5 K, will provide the required acceleration field for ramping the beam energy up to 7 TeV and for keeping the colliding proton beams tightly bunched. Superconducting cavities were chosen, not only because of their high acceleration field leading to a small contribution to the machine impedance, but also because of their high stored energy which minimises the effects of periodic transient beam loading associated with the high beam intensity (0.5 A). There will be eight single-cell cavities per beam, each delivering 2 MV (5.3 MV/m) at 400 MHz. The cavities themselves are now being manufactured by industrial firms, using niobium on copper technology which gives full satisfaction at LEP. A complete cavity prototype assembly in...

Boussard, Daniel

1999-01-01T23:59:59.000Z

388

Introduction to progress and promise of superconductivity for energy storage in the electric power sector  

SciTech Connect (OSTI)

Around the world, many groups conduct research, development and demonstration (RD and D) to make storage an economic option for the electric power sector. The progress and prospects for the application of superconductivity, with emphasis on high-temperature superconductivity, to the electric power sector has been the topic of an IEA Implementing Agreement, begun in 1990. The present Task members are Canada, Denmark, Finland, Germany, Israel, Italy, Japan, Korea, the Netherlands, Norway, Sweden, Switzerland, Turkey, the United Kingdom and the US. As a result of the Implementing Agreement, work has been done by the Operating Agent with the full participation of all the member countries. This work has facilitated the exchange of informtion among experts in all countries and has documented relevant assessments. Further, this work has reviewed the status of SMES and is now updating same, as well as investigating the progress on and prospects for flywheels with superconducting bearings. The Operating Agent and Task members find a substantially different set of opportunities for and alternatives to storage than was the case before the 1987 discovery of high-temperature superconductivity. Beside the need to level generation, there is also the need to level the load on transmission lines, increase transmission stability, and increase power quality. These needs could be addressed by high power storage that could be brought in and out of the grid in fractions of a second. Superconducting Magnetic Energy Storage and flywheels with superconducting bearings are devices that deserve continued RD and D because they promise to be the needed storage devices.

Wolsky, A.M.

1998-05-01T23:59:59.000Z

389

Elaboration of the alpha-model derived from the BCS theory of superconductivity  

SciTech Connect (OSTI)

The single-band ?-model of superconductivity (Padamsee et al 1973 J. Low Temp. Phys. 12 387) is a popular model that was adapted from the single-band Bardeen–Cooper–Schrieffer (BCS) theory of superconductivity mainly to allow fits to electronic heat capacity versus temperature T data that deviate from the BCS prediction. The model assumes that the normalized superconducting order parameter ?(T)/?(0) and therefore the normalized London penetration depth ?L(T)/?L(0) are the same as in BCS theory, calculated using the BCS value ?BCS ? 1.764 of ? ? ?(0)/kBTc, where kB is The single-band ?-model of superconductivity (Padamsee et al 1973 J. Low Temp. Phys. 12 387) is a popular model that was adapted from the single-band Bardeen–Cooper–Schrieffer (BCS) theory of superconductivity mainly to allow fits to electronic heat capacity versus temperature T data that deviate from the BCS prediction. The model assumes that the normalized superconducting order parameter ?(T)/?(0) and therefore the normalized London penetration depth ?L(T)/?L(0) are the same as in BCS theory, calculated using the BCS value ?BCS ? 1.764 of ? ? ?(0)/kBTc, where kB is Boltzmann's constant and Tc is the superconducting transition temperature. On the other hand, to calculate the electronic free energy, entropy, heat capacity and thermodynamic critical field versus T, the ?-model takes ? to be an adjustable parameter. Here we write the BCS equations and limiting behaviors for the superconducting state thermodynamic properties explicitly in terms of ?, as needed for calculations within the ?-model, and present plots of the results versus T and ? that are compared with the respective BCS predictions. Mechanisms such as gap anisotropy and strong coupling that can cause deviations of the thermodynamics from the BCS predictions, especially the heat capacity jump at Tc, are considered. Extensions of the ?-model that have appeared in the literature, such as the two-band model, are also discussed. Tables of values of ?(T)/?(0), the normalized London parameter ?(T)/?(0) and ?L(T)/?L(0) calculated from the BCS theory using ? = ?BCS are provided, which are the same in the ?-model by assumption. Tables of values of the entropy, heat capacity and thermodynamic critical field versus T for seven values of ?, including ?BCS, are also presented.

Johnston, David C. [Ames Laboratory

2013-10-14T23:59:59.000Z

390

Superconducting transition temperature in heterogeneous ferromagnet-superconductor systems  

E-Print Network [OSTI]

and located at the planes zn5nd (n is an integer!. The vector potential Av due to the pancake vortices at SC layers satisfies a following equation: 2DAv~r,z !1 1 L (n d~z2zn!Av~r,z ! 5 f0 2pL (n d~z2zn!(np dnp? (2)wn~r2rnp!. ~34! 5 VALERY L.... POKROVSKY AND HONGDUO WEI PHYSICAL REVIEW B 69, 104530 ~2004! The vector potential in Eq. ~34! is induced by pancake vor- tices with the vorticity dnp561 placed at the position rnp , where p enumerates vortices in the nth plane. The Coulomb gauge ??Av50...

Pokrovsky, Valery L.; Wei, HD.

2004-01-01T23:59:59.000Z

391

Brushless exciters using a high temperature superconducting field winding  

DOE Patents [OSTI]

A brushless exciter for a synchronous generator or motor generally includes a stator and a rotor rotatably disposed within the stator. The rotor has a field winding and a voltage rectifying bridge circuit connected in parallel to the field winding. A plurality of firing circuits are connected the voltage rectifying bridge circuit. The firing circuit is configured to fire a signal at an angle of less than 90.degree. or at an angle greater than 90.degree.. The voltage rectifying bridge circuit rectifies the AC voltage to excite or de-excite the field winding.

Garces, Luis Jose (Schenectady, NY); Delmerico, Robert William (Clifton Park, NY); Jansen, Patrick Lee (Scotia, NY); Parslow, John Harold (Scotia, NY); Sanderson, Harold Copeland (Tribes Hill, NY); Sinha, Gautam (Chesterfield, MO)

2008-03-18T23:59:59.000Z

392

Optimisation of hysteretic losses in high-temperature superconducting wires.  

E-Print Network [OSTI]

??Hysteretic loss optimisations through numerical simulation and subsequent experimental confirmation in transport current and background field measurements: ferromagnetic shielding and topological geometry optimisation is used… (more)

Krüger, Philipp

2014-01-01T23:59:59.000Z

393

RHIC Project | Superconducting Magnet Division  

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

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

394

ORNL Superconducting Technology Program for Electric Energy Systems  

SciTech Connect (OSTI)

The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy's (DOE's) Office of Conservation and Renewable Energy to develop the technology base needed by US industry for commercial development of electric power applications of high-temperature superconductivity. The two major elements of this program are wire development and systems development. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from information prepared for the FY 1992 Peer Review of Projects, conducted by DOE's Office of Program Analysis, Office of Energy Research. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. Interlaboratory teams are also in place on a number of industry-driven projects. Patent disclosures, working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer to US industry. Working together, the collaborative teams are making tremendous progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high-temperature superconductor wire and wire products.

Hawsey, R.A. (comp.)

1993-02-01T23:59:59.000Z

395

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

396

New Advances in SuperConducting Materials  

ScienceCinema (OSTI)

Superconducting materials will transform the world's electrical infrastructure, saving billions of dollars once the technical details and installation are in place. At Los Alamos National Laboratory, new materials science concepts are bringing this essential technology closer to widespread industrial use.

None

2014-08-12T23:59:59.000Z

397

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

398

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

399

Dissipative hydride precipitates in superconducting niobium cavities  

SciTech Connect (OSTI)

We report the first direct observation of the microstructural features exhibiting RF losses at high surface magnetic fields of above 100 mT in field emission free superconducting niobium cavities. The lossy areas were identified by advanced thermometry. Surface investigations using different techniques were carried out on cutout samples from lossy areas and showed the presence of dendritic niobium hydrides. This finding has possible implications to the mechanisms of RF losses in superconducting niobium at all field levels.

Romanenko, A.; Cooley, L.D.; /Fermilab; Ciovati, G.; / /Jefferson Lab; Wu, G.; /Argonne

2011-10-01T23:59:59.000Z

400

Two pairing parameters in superconducting grains  

Science Journals Connector (OSTI)

Unlike bulk superconductivity, where one energy scale, the energy gap, characterizes pairing correlations, we show that in small superconducting grains there exist two different such quantities. The first characterizes collective properties of the grain, such as the condensation energy, and the second single-particle properties. To describe these two energy scales, we define two corresponding pairing parameters, and show that although both reduce to the bulk gap for large grains, this occurs at different size scales.

M. Schechter; J. von Delft; Y. Imry; Y. Levinson

2003-02-27T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

Efficient incorporation of silver to improve superconducting fibers  

DOE Patents [OSTI]

An improved method for the efficient incorporation of a metal such as silver in a superconducting material includes blending the metal with a high temperature superconductor or precursor powder and consolidating the same into pellets. The pellets are charged directly into a heating assembly where it is melted and heated sufficiently to a uniform temperature prior to fiberization. Droplets of the melted blend fall through a collar into a nozzle where they are subjected to a high velocity gas to break the melted material into ligaments which solidify into improved flexible fibers having the metal homogeneously dis This invention was made with Government support under a contract with the Department of Energy (DOE) and Ames Laboratory, Contract No. SC-91-225, our reference No. CRD-1272. The Government has certain rights in this invention.

Gleixner, Richard A. (North Canton, OH); LaCount, Dale F. (Alliance, OH); Finnemore, Douglas K. (Ames, IA)

1994-04-26T23:59:59.000Z

402

The superconducting spin valve and triplet superconductivity I.A. Garifullin a,n  

E-Print Network [OSTI]

The superconducting spin valve and triplet superconductivity I.A. Garifullin a,n , P.V. Leksin s t r a c t A review of our recent results on the spin valve effect is presented. We have used coefficient DF and the exchange splitting I of the conduction band in the F layer [1]. For pure Fe the value

Fominov, Yakov

403

Electric-field dependence of pairing temperature and tunneling in high-temperature superconductors  

Science Journals Connector (OSTI)

Using the Bethe-Salpeter equation including high electric fields, the dependence of the critical temperature of onsetting superconductivity on the applied field is calculated analytically. The critical temperature of pairing is shown to increase with the applied field strength. This is a new field effect and could contribute to the explanation of recent experiments on field-induced superconductivity. From the field dependence of the Bethe-Salpeter equation, the two-particle bound-state solution is obtained as a resonance with a tunneling probability analogous to the WKB solution of a single particle confined in a potential and coupled to an electrical field.

K. Morawetz

2002-11-27T23:59:59.000Z

404

Two-band model of a high-temperature superconductor and the dependence of the critical temperature of transition on the parameters of the model  

Science Journals Connector (OSTI)

Within the limit of weak coupling with allowance for the level of hybridization and polarization of states, dependences of the critical temperature of the superconducting transition on the concentration of car...

L. G. Zhidkov; A. G. Tret’yakov; T. N. Adrianova

2006-07-01T23:59:59.000Z

405

Modeling and Simulation of Resistive Superconducting Fault-Current Limiters  

Science Journals Connector (OSTI)

Superconducting fault-current limiters (SFCL) offer ideal performance in electrical ... simulation model for a novel resistive type superconducting fault-current limiter is proposed. This model includes the elect...

S. Nemdili; S. Belkhiat

2012-10-01T23:59:59.000Z

406

MATHEMATICAL ANALYSIS OF CONDUCTING AND SUPERCONDUCTING TRANSMISSION LINES  

E-Print Network [OSTI]

MATHEMATICAL ANALYSIS OF CONDUCTING AND SUPERCONDUCTING TRANSMISSION LINES ANNE-SOPHIE BONNET propagation in the microstrip transmission lines used in microelectronics. In the first part, the case of the perfectly conducting strip. Key words. superconducting transmission lines, waveguides, spectral analysis

Ramdani, Karim - Institut de Mathématiques �lie Cartan, Université Henri Poincaré

407

A Modular Superconducting Generator for Offshore Wind Turbines  

Science Journals Connector (OSTI)

In this study, a new claw-pole type transverse flux superconducting generator topology is presented. The machine has a stationary superconducting field winding, which eliminates electrical brushes and cryocoupler...

Ozan Keysan; Dariusz Olczak…

2013-05-01T23:59:59.000Z

408

Superconducting magnets for toroidal fusion reactors  

SciTech Connect (OSTI)

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

Haubenreich, P.N.

1980-01-01T23:59:59.000Z

409

Development of scaling rules for Rutherford type superconducting cables  

SciTech Connect (OSTI)

During the R D phase of the Superconducting Supercollider (SSC) program, LBL was responsible for establishing the parameters for cables used in SSC dipole and quadrupole magnets. In addition, the design and fabrication of a new cable for use in the Low Beta Quadrupoles. As a result of the development work on these and other cables, we have arrived a set of scaling rules which provide guidelines for choosing the parameters for a wide range of superconducting cables. These parameters include strand size, strand number, keystone angle, percent compaction, cable pitch and compacted cable dimensions. In addition, we have defined the tolerance ranges for the key cable manufacturing parameters such as mandrel size and shape, stand tension, and Turkshead temperature control. In this paper, we present the results on cables ranging from 8 strands to 36 strands of 0.65mm wire and from 8 strands to 30 strands of 0.8mm wire. We use these results to demonstrate the application of the scaling rules for Rutherford-type cable.

Royet, J.M.; Scanlan, R.M.

1990-09-01T23:59:59.000Z

410

Effects of lithium additions on processing of Bi-Sr-Ca-Cu-O superconducting tapes  

SciTech Connect (OSTI)

Lithium additions to the high-temperature superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} (2212) increased superconducting transition temperatures and improved resistance to effects of magnetic fields. In addition, these additions lowered the melting point of 2212 and increased reaction kinetics. Ag-clad tapes fabricated from 2212 with and without Li exhibited profound differences. For heating to temperatures less than or equal to 840{degrees}C, grain growth and sintering were much more substantial in the tapes containing Li.

Goretta, K.C.; Li, Y.F.; Poeppel, R.B. [Argonne National Lab., IL (United States); Wu, S.; Guo, J. [Illinois Univ., Urbana, IL (United States). Dept. of Nuclear Engineering; Schwartz, J. [Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Laboratory

1994-01-01T23:59:59.000Z

411

Frequency-Domain Multiplexed Readout for Superconducting Gamma-Ray Detectors  

SciTech Connect (OSTI)

We are developing a frequency-multiplexed readout for arrays of high-resolution Gamma detectors based on superconducting transition edge sensors (TESs). Each sensor is part of an LCR resonant circuit and is biased at an identifying carrier frequency. Several carrier signals are added and amplified with a single SQUID preamplifier at 4 K. Gamma absorption modulates the amplitude of the carrier, and demodulation at room temperature retrieves the initial temperature evolution of the sensor. This multiplexing system has originally been developed to read out large arrays of bolometers for cosmic microwave background studies. To accommodate the faster Gamma-ray signals, its demodulator bandwidth is being extended to 20 kHz to allow reading out up to eight TESs with a detector bandwidth of 10 kHz. Here we characterize the system noise performance and show how this multiplexing scheme can be adapted to read out arrays of superconducting Gamma-ray detectors.

Dreyer, Jonathan G.; Arnold, Kam; Lanting, Trevor M.; Dobbs, Matt A.; Friedrich, Stephan; Lee, Adrian T.; Spieler, Helmuth G.

2006-08-30T23:59:59.000Z

412

Proximity-induced superconductivity effect in a double-stranded DNA  

SciTech Connect (OSTI)

We study the proximity-induced superconductivity effect in a double-stranded DNA by solving the Bogoliubov-de Gennes equations and taking into account the effect of thermal fluctuations of the twist angle between neighboring base pairs. We show that the electron conductance is spin-dependent and the conductance of spin up (down) increases (decreases) due to the spin-orbit coupling (SOC). It is found that, for T?temperature-independent and it decreases due to the SOC. In addition, by solving the Bogoliubov-de Gennes equations and local gap parameter equation self-consistently, we find the critical temperature at which transition to superconductivity can take place.

Simchi, Hamidreza, E-mail: simchi@iust.ac.ir [Department of Physics, Iran University of Science and Technology, Narrmak, Tehran 16844 (Iran, Islamic Republic of); Semiconductor Technology Center, Tehran (Iran, Islamic Republic of); Esmaeilzadeh, Mahdi, E-mail: mahdi@iust.ac.ir; Mazidabadi, Hossein [Department of Physics, Iran University of Science and Technology, Narrmak, Tehran 16844 (Iran, Islamic Republic of)

2014-02-07T23:59:59.000Z

413

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

E-Print Network [OSTI]

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

Medvedeva, Julia E.

414

Enabling instrumentation and technology for 21st century light sources  

E-Print Network [OSTI]

undulators using high temperature superconductor tape, i n :clear aperture. The high temperature superconductor (HTS)For stacked high temperature superconductor (HTS) u n d u l

Byrd, J.M.

2011-01-01T23:59:59.000Z

415

HigHligHts  

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

"MRCSP Begins Field Tests in Michigan." The Midwest Regional Carbon Sequestration Partnership (MRCSP) has begun a large-scale CO 2 field project. The project is designed to inject and monitor at least 1 million metric tons of CO 2 into a series of oil fields that are in different stages of their production life cycles. The CO 2 will be injected into the geologic structures known as the northern Niagaran pinnacle reef trend. From Battelle News Release on July 9, 2013. Announcements DOE's NETL Releases Revised Editions of Best Practice Manuals (BPMs). The U.S. Department of Energy's (DOE) National Energy Technology Laboratory (NETL) released revised editions of the following Best

416

HigHligHts  

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

"MRCSP Begins Field Tests in Michigan." "MRCSP Begins Field Tests in Michigan." The Midwest Regional Carbon Sequestration Partnership (MRCSP) has begun a large-scale CO 2 field project. The project is designed to inject and monitor at least 1 million metric tons of CO 2 into a series of oil fields that are in different stages of their production life cycles. The CO 2 will be injected into the geologic structures known as the northern Niagaran pinnacle reef trend. From Battelle News Release on July 9, 2013. Announcements DOE's NETL Releases Revised Editions of Best Practice Manuals (BPMs). The National Energy Technology Laboratory (NETL) released revised editions of the following Best Practice Manuals (BPMs): "Public

417

HigHligHts  

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

President Requests $638.0 Million for Fossl Energy Programs." President Requests $638.0 Million for Fossl Energy Programs." The FY 2014 budget request seeks $638 million for the Office of Fossil Energy (FE) to advance technologies related to the reliable, efficient, affordable, and environmentally sound use of fossil fuels, as well as managing the Strategic Petroleum Reserve and Northeast Home Heating Oil Reserve. The request includes $420 million for the fossil energy research and development (R&D) portfolio. For the Carbon

418

RHIC Superconducting Accelerator and Electron Cooling Group  

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

419

J-PARC Correctors | Superconducting Magnet Division  

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

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

420

Summary results of an assessment of research projects in the superconductivity for electric power systems program  

SciTech Connect (OSTI)

The Office of Program Analysis undertook an assessment of 37 research projects sponsored by the High Temperature Superconductivity Program. This report summarizes the results of the review. Rating factors included scientific and technical merit, mission relevance, appropriateness and level of innovation, quality of project team, productivity, and probable impact on the program`s mission. Some research needs and opportunities are described that were identified by the reviewers in the areas of wire development, deposited film technology, and systems development.

NONE

1992-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "temperature superconducting hts" 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

Bogoliubov Shadow Bands in the Normal State of Superconducting Systems with Strong Pair Fluctuations  

Science Journals Connector (OSTI)

On the basis of a scenario where electron pairing is induced by resonant two-particle scattering (the boson-fermion model), we show how precursors of the superconducting state—in the form of overdamped Bogoliubov modes—emerge in the normal state upon approaching the transition temperature from above. This result is obtained by a renormalization technique based on continuous unitary transformations (the flow equations), projecting out the coherent contributions in the electron spectral function from an incoherent background.

T. Domanski and J. Ranninger

2003-12-18T23:59:59.000Z

422

Proximity effects in superconducting triplet spin-valve F2/F1/S  

Science Journals Connector (OSTI)

Abstract We investigate the critical temperature Tc of F2/F1/S trilayers (Fi is a ferromagnetic metal and S is a singlet superconductor), where the long-range triplet superconducting component is generated at noncollinear magnetizations of the F layers. In this paper we demonstrate a possibility of the spin-valve effect mode selection (standard switching effect, the triplet spin-valve effect or reentrant T c ( ? ) dependence) by the variation of the F2/F1 interface transparency.

R.G. Deminov; L.R. Tagirov; R.R. Gaifullin; T.Yu. Karminskaya; M.Yu. Kupriyanov; Ya.V. Fominov; A.A. Golubov

2015-01-01T23:59:59.000Z

423

Dynamic high pressure process for fabricating superconducting and permanent magnetic materials  

DOE Patents [OSTI]

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

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

1990-03-13T23:59:59.000Z

424

Termination for a superconducting power transmission line including a horizontal cryogenic bushing  

DOE Patents [OSTI]

A termination for a superconducting power transmission line is disclosed which is comprised of a standard air entrance insulated vertical bushing with an elbow, a horizontal cryogenic bushing linking the pressurized cryogenic cable environment to the ambient temperature bushing and a stress cone which terminates the cable outer shield and transforms the large radial voltage gradient in the cable dielectric into a much lower radial voltage gradient in the high density helium coolant at the cold end of the cryogenic bushing.

Minati, Kurt F. (Northport, NY); Morgan, Gerry H. (Patchogue, NY); McNerney, Andrew J. (Shoreham, NY); Schauer, Felix (Upton, NY)

1984-01-01T23:59:59.000Z

425

Full-wave analysis of superconducting microstrip lines on anisotropic substrates using equivalent surface impedance approach  

SciTech Connect (OSTI)

A computationally efficient full-wave technique is developed to analyze single and coupled superconducting microstrip lines on anisotropic substrates. The optic axis of the dielectric is in the plane of the substrate at an arbitrary angle with respect to the propagation direction. A dyadic Green's function for layered, anisotropic media is used to formulate an integral equation for the current in the strips. To increase the efficiency of the method, the superconducting strips are replaced by equivalent surface impedances which account for the loss and kinetic inductance of the superconductors. The validity of this equivalent surface impedance (ESI) approach is verified by comparing the calculated complex propagation constant and characteristic impedance for superconducting microstrip lines on an isotropic substrate to measured results, and to numerical results by the more rigorous volume-integral equation method. The results calculated using the ESI approach for perfectly conducting coupled lines on an anisotropic substrate agree with the results by the finite-difference time-domain method. This efficient ESI technique is then used to study the effects of the optic axis orientation and the strip width on the characteristics of single and coupled superconducting microstrip lines on M-plane sapphire. The effects of the line separation and operating temperature on the coupled lines are also investigated.

Lee, L.H.; Lyons, W.G.; Orlando, T.P.; Ali, S.M. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Electrical Engineering and Computer Science); Lyons, W.G. (Massachusetts Inst. of Tech., Lexington, MA (United States). Lincoln Lab.); Withers, R.S. (Conductus, Inc., Sunnyvale, CA (United States))

1993-12-01T23:59:59.000Z

426

Measurement of the vortex depinning force in a high temperature superconductor  

E-Print Network [OSTI]

Introduction: Superconductivity is one of those subjects in physics that is as captivating theoretically as it is experimentally interesting. The dual driving force of commercial demand for high-temperature superconductors ...

Whitehead, Andrew Patrick

2005-01-01T23:59:59.000Z

427

Nanoscale Interplay of Strain and Doping in a High-Temperature Superconductor  

Science Journals Connector (OSTI)

The highest-temperature superconductors are electronically inhomogeneous at the nanoscale, suggesting the existence of a local variable that could be harnessed to enhance the superconducting pairing. Here we report the relationship between local doping ...

Ilija Zeljkovic; Jouko Nieminen; Dennis Huang; Tay-Rong Chang; Yang He; Horng-Tay Jeng; Zhijun Xu; Jinsheng Wen; Genda Gu; Hsin Lin; Robert S. Markiewicz; Arun Bansil; Jennifer E. Hoffman

2014-11-03T23:59:59.000Z

428

Recent advances in fabrication of high-T{sub c} superconductors for electric power applications.  

SciTech Connect (OSTI)

The U.S. Department of Energy (DOE) supports an applied superconductivity program entitled ''Superconductivity Program for Electric Power Systems.'' Activities within this program contribute to development of the high-temperature superconductor (HTS) technology needed for industry to proceed with the commercial development of electric power applications such as motors, generators, transformers, transmission cables, and current limiters. Research is conducted in three categories: wire development, systems technology development, and Superconductivity Partnership Initiative (SPI). Wire development activities are devoted to improving the critical current density (J{sub c}) of short-length HTS wires, whereas systems technology development focuses on fabrication of long-length wires, coils, and on magnets. The SPI activities are aimed at development of prototype products. Significant progress has been made in the development of (HTSs) for various applications: some applications have already made significant strides in the marketplace, while others are still in the developmental stages. For successful electric power applications, it is very important that the HTS be fabricated into long-length conductors that exhibit desired superconducting and mechanical properties. Several parameters of the PIT technique must be carefully controlled to obtain the desired properties. Long lengths of Bi-2223 tapes with respectable superconducting properties have been fabricated by a carefully designed thermomechanical treatment process. A 1-MVA capacity fault current limiter, a 286-hp motor, and 630-kVA transformers, and a 50-m-long conductor, all using HTSs, have already been demonstrated. While the use of HTS devices in the electric utility area has clear advantages, impediments to successful commercialization remain. Issues such as AC losses, conductor cost, and reliable superconducting joints must be addressed. The cost of HTS conductors are still quite high, and significant R and D effort must be focused on this issue. The general acceptance of HTS power equipment will ultimately be based on system performance, reliability and maintenance, efficiency, and installed cost relative to those of conventional technologies.

Balachandran, U.

1998-03-25T23:59:59.000Z

429

TEACHER NOTES The Effect of Temperature on Electrical Resistance  

E-Print Network [OSTI]

superconducting tape2 , resistor, wire and/or other materials to serve as resistive samples Wire leadsTEACHER NOTES The Effect of Temperature on Electrical Resistance Abstract: This project allows students to experimentally discover the temperature dependence of resistance using a copper wire

Quigg, Chris

430

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

SciTech Connect (OSTI)

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

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

2012-06-22T23:59:59.000Z

431

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

SciTech Connect (OSTI)

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

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

1996-07-01T23:59:59.000Z

432

Nano-superconducting quantum interference devices with suspended junctions  

SciTech Connect (OSTI)

Nano-Superconducting Quantum Interference Devices (nano-SQUIDs) are usually fabricated from a single layer of either Nb or Al. We describe here a simple method for fabricating suspended nano-bridges in Nb/Al thin-film bilayers. We use these suspended bridges, which act as Josephson weak links, to fabricate nano-SQUIDs which show critical current oscillations at temperatures up to 1.5?K and magnetic flux densities up to over 20?mT. These nano-SQUIDs exhibit flux modulation depths intermediate between all-Al and all-Nb devices, with some of the desirable characteristics of both. The suspended geometry is attractive for magnetic single nanoparticle measurements.

Hazra, D.; Hasselbach, K. [Institut Néel, CNRS and Université Joseph Fourier, 25 Avenue des Martyrs, Grenoble (France); Kirtley, J. R. [Center for Probing the Nanoscale, Stanford University, Palo Alto, California 94305-4045 (United States)

2014-04-14T23:59:59.000Z

433

First-order disorder-driven transition and inverse melting of the vortex lattice  

E-Print Network [OSTI]

`inverse' melting behavior. � 2001 Published by Elsevier Science B.V. Keywords: Type-II superconductivity-order transition (FOT) [1±5] whereas at low temperatures the ordered vortex lattice transforms into a disordered open questions in the phase diagram of HTS is the thermodynamic nature of the disorder-dri- ven

Zeldov, Eli

434

CX-005079: Categorical Exclusion Determination  

Broader source: Energy.gov [DOE]

Design, Test and Demo of Saturable Reactor High Temperature Superconducting (HTS) Fault Current LimiterCX(s) Applied: B4.6, B4.11Date: 01/24/2011Location(s): Brilliant, OhioOffice(s): Electricity Delivery and Energy Reliability, National Energy Technology Laboratory

435

Superconducting switch concept applied to superconducting undulator phase-error correction  

SciTech Connect (OSTI)

Superconducting undulator (SCU) technology has the potential to significantly enhance the performance of synchrotron radiation sources for storage ring and FEL applications. Since 2002, our team at Lawrence Berkeley National Laboratory has been performing R and D on superconducting undulators, including the fabrication of three Nb{sub 3}Sn prototypes. We have demonstrated experimentally the possibility to provide the prototype with trim coils that could be used for phase error correction. The research effort that we report here demonstrates the possibility to add degrees of freedom to the field correction provided by these coils in a cryogenic environment. By means of bridge of superconducting switches, we can modify the current direction through a trim coil. Here we describe the design of the experimental bridge we fabricated, the results we obtained and finally the generalized concept one could plan to apply to correct the phase errors with trim coils connected to a network of superconducting bridges.

Madur, A.; Trillaud, F.; Dietderich, D.; Marks, S.; Prestemon, S.; Schlueter, R. [LBNL, 1 Cyclotron Road, BERKELEY, CA, 94720 (United States)

2010-06-23T23:59:59.000Z

436

Method and apparatus for cooling high temperature superconductors with neon-nitrogen mixtures  

DOE Patents [OSTI]

Apparatus and methods for cooling high temperature superconducting materials (HTSC) to superconductive temperatures within the range of 27.degree. K. to 77.degree. K. using a mixed refrigerant consisting of liquefied neon and nitrogen containing up to about ten mole percent neon by contacting and surrounding the HTSC material with the mixed refrigerant so that free convection or forced flow convection heat transfer can be effected.

Laverman, Royce J. (South Holland, IL); Lai, Ban-Yen (Hinsdale, IL)

1993-01-01T23:59:59.000Z

437

Thermal stabilization of superconducting sigma strings and their drum vortons  

Science Journals Connector (OSTI)

We discuss various issues related to stabilized embedded strings in a thermal background. In particular, we demonstrate that such strings will generically become superconducting at moderately low temperatures, thus enhancing their stability. We then present a new class of defects—drum vortons—which arise when a small symmetry breaking term is added to the potential. We display these points within the context of the O(4) sigma model, relevant for hadrodynamics below the QCD scale. This model admits “embedded defects” (topological defect configurations of a simpler—in this case O(2) symmetric—model obtained by imposing an embedding constraint) that are unstable in the full model at zero temperature, but that can be stabilized (by electromagnetic coupling to photons) in a thermal gas at moderately high termperatures. It is shown here that below the embedded defect stabilization threshold, there will still be stabilized cosmic string defects. However, they will not be of the symmetric embedded vortex type, but of an “asymmetric” vortex type, and are automatically superconducting. In the presence of weak symmetry breaking terms, such as arise naturally when using the O(4) model for hadrodynamics, the strings become the boundary of a new kind of cosmic sigma membrane, with tension given by the pion mass. The string current would then make it possible for a loop to attain a (classically) stable equilibrium state that differs from an “ordinary” vorton state by the presence of a sigma membrane stretched across it in a drum-like configuration. Such defects will however be entirely destabilized if the symmetry breaking is too strong, as is found to be the case—due to the rather large value of the pion mass—in the hadronic application of the O(4) sigma model.

Brandon Carter; Robert H. Brandenberger; Anne-Christine Davis

2002-05-14T23:59:59.000Z

438

Putting Accelerator Technology to Work Fully Superconducting GunFully Superconducting Gun  

E-Print Network [OSTI]

Putting Accelerator Technology to Work Fully Superconducting GunFully Superconducting Gun BNL PS Gun LANL/AES NC or AES FS gun e- 1.5-2.5 MeV 500-300 mA CW * e- 1.6-2.8 MeV 500-300 mA CW Beam cavity with low current beam * NC gun with derated gradient FS gun permits 25% higher current Ilan Ben

439

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

SciTech Connect (OSTI)

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

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

2008-01-01T23:59:59.000Z

440

No Slide Title  

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

Second Generation HTS Quadrupole Second Generation HTS Quadrupole for FRIB ASC 2010 Aug 5, 2010 0 Second Generation HTS Quadrupole for FRIB R. Gupta, M. Anerella, G. Ganetis, A. Ghosh, G. Greene, W. Sampson, Y. Shiroyanagi, P. Wanderer Brookhaven National Laboratory A. Zeller, Senior Member IEEE Michigan State University Superconducting Magnet Division Ramesh Gupta Second Generation HTS Quadrupole for FRIB ASC 2010 Aug 5, 2010 1 Overview * What is FRIB ? * Why HTS Quad ? * 1 st Generation HTS Quad * 2 nd Generation Design, Related Test Results * Summary Superconducting Magnet Division Ramesh Gupta Second Generation HTS Quadrupole for FRIB ASC 2010 Aug 5, 2010

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441

Superconducting high-pressure phases of disilane  

Science Journals Connector (OSTI)

...Superconducting high-pressure phases of disilane 10.1073/pnas.1005242107 Xilian...DC 20015 High-pressure structures of disilane (Si2H6) are investigated extensively...linear-response calculations for Pm-3m disilane at 275 GPa show a large electron-phonon...

Xilian Jin; Xing Meng; Zhi He; Yanming Ma; Bingbing Liu; Tian Cui; Guangtian Zou; Ho-kwang Mao

2010-01-01T23:59:59.000Z

442

Testing Gravitational Physics with Superconducting Gravimeters  

Science Journals Connector (OSTI)

......being improved in geo- physics.29),30) Therefore...would fall at different rates towards the Sun and other...Testing Gravitational Physics with Superconducting...such dilatonic waves pass the Earth, because of...tests of gravitational physics in the previous sections......

Sachie Shiomi

2008-01-01T23:59:59.000Z

443

Flux Exclusion Superconducting Quantum Metamaterial: Towards  

E-Print Network [OSTI]

. Recently, arrays of Josephson junction devices have been proposed as a possible solution. However-atoms containing Josephson junctions15­19 , experiments have been conducted on single superconducting qubit meta-atoms20,21 and one- dimensional Josephson junction metamaterials22 . The recently discovered class of iron

Zheludev, Nikolay

444

Aluminum in Superconducting Magnets Robert J. Weggel  

E-Print Network [OSTI]

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

McDonald, Kirk

445

Design of a horizontal test cryostat for superconducting RF cavities for the FREIA facility at Uppsala University  

SciTech Connect (OSTI)

Uppsala University is constructing a large scale facility, called FREIA (Facility for Research Instrumentation and Accelerator Development). FREIA includes a helium liquefier and an accelerator test facility and has the capacity to test superconducting radio-frequency (RF) cavities with the same RF system and RF power level as in an accelerator. A central element of FREIA is a horizontal test cryostat connected in closed loop to a helium liquefier. This cryostat can house two fully equipped (tuners, piezo, power coupler, helium tank) superconducting cavities to perform full RF high power tests and operate at temperatures between 1.8 K and 4.2 K. The cryostat is designed to accommodate a large array of superconducting cavities and magnets, among which the European Spallation Source (ESS) type spoke and high-? elliptical cavities as well as TESLA/ILC type elliptical cavities. The present status of the project and the design of the cryostat are reported.

Chevalier, N. R.; Thermeau, J.-P.; Bujard, P.; Junquera, T. [Accelerators and Cryogenic Systems (ACS), 86 rue de Paris, 91400 Orsay (France); Hermansson, L.; Kern, R. Santiago; Ruber, R. [Uppsala University, Department of Physics and Astronomy, 75120 Uppsala (Sweden)

2014-01-29T23:59:59.000Z

446

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

E-Print Network [OSTI]

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

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

2014-01-01T23:59:59.000Z

447

Unsteady heat dissipation in accelerator superconducting coils insulated with porous ceramic insulation in normal and supercritical helium conditions  

SciTech Connect (OSTI)

To investigate the unsteady heat dissipation in accelerator superconducting coils insulated with porous ceramic insulation, two experimental mock-ups reproducing the thermal and the mechanical conditions of a superconducting coils were produced. The mock-ups with compressive load of 10 MPa and 20 MPa were tested at normal (T = 4.23 K and p = 1 bar) and supercritical helium conditions (T = 4.23 K and p = 2.0 to 3.75 bar) during unsteady heat dissipation. The paper presents the experimental results of temperature rise in both superconducting coils as a function of time for a wide range of a localized heat load varying from 0.1 kJ/m{sup 3} up to 12.8 MJ m{sup ?3} per pulse. A numerical model of the transient process in these coils has been developed and the computations are compared with the experimental results.

Pietrowicz, S. [Department of Thermodynamics, Institute of Power Engineering and Fluid Mechanics, Wroc?aw University of Technology, Wybrze?e Wyspia?skiego 27, 50 - 370 Wroc?aw (Poland); Four, A.; Baudouy, B. [CEA Saclay, Irfu/ SACM, 91191 Gif-sur-Yvette (France); Kimura, N.; Yamamoto, A. [High Energy Accelerator Research Organization, KEK, Tsukuba, Ibaraki 305-0801 (Japan)

2014-01-29T23:59:59.000Z

448

Magnetism in SQUIDs at Millikelvin Temperatures  

Science Journals Connector (OSTI)

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

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

2008-06-05T23:59:59.000Z

449

Inelastic neutron scattering study of a nonmagnetic collapsed tetragonal phase of CaFe2As2: Evidence of the impact of spin fluctuations on superconductivity in the iron-arsenide compounds.  

SciTech Connect (OSTI)

The relationship between antiferromagnetic spin fluctuations and superconductivity has become a central topic of research in studies of superconductivity in the iron pnictides. We present unambiguous evidence of the absence of magnetic fluctuations in the non-superconducting collapsed tetragonal phase of CaFe2As2 via inelas- tic neutron scattering time-of-flight data, which is consistent with the view that spin fluctuations are a necessary ingredient for unconventional superconductivity in the iron pnictides. We demonstrate that the collapsed tetrag- onal phase of CaFe2As2 is non-magnetic, and discuss this result in light of recent reports of high-temperature superconductivity in the collapsed tetragonal phase of closely related compounds.

Soh, Jing Han [ORNL] [ORNL; Tucker, G. S. [Ames Laboratory and Iowa State University] [Ames Laboratory and Iowa State University; Pratt, Daniel K [ORNL] [ORNL; Abernathy, Douglas L [ORNL] [ORNL; Stone, Matthew B [ORNL] [ORNL; Ran, S. [Ames Laboratory and Iowa State University] [Ames Laboratory and Iowa State University; Budko, S L [Ames Laboratory and Iowa State University] [Ames Laboratory and Iowa State University; Canfield, P. C. [Ames Laboratory] [Ames Laboratory; Kreyssig, A. [Ames Laboratory and Iowa State University] [Ames Laboratory and Iowa State University; McQueeney, R. J. [Ames Laboratory] [Ames Laboratory; Goldman, A. I. [Ames Laboratory and Iowa State University] [Ames Laboratory and Iowa State University

2013-01-01T23:59:59.000Z

450

Superconductivity and the environment: a Roadmap  

Science Journals Connector (OSTI)

There is universal agreement between the United Nations and governments from the richest to the poorest nations that humanity faces unprecedented global challenges relating to sustainable energy, clean water, low-emission transportation, coping with climate change and natural disasters, and reclaiming use of land. We have invited researchers from a range of eclectic research areas to provide a Roadmap of how superconducting technologies could address these major challenges confronting humanity.Superconductivity has, over the century since its discovery by Kamerlingh Onnes in 1911, promised to provide solutions to many challenges. So far, most superconducting technologies are esoteric systems that are used in laboratories and hospitals. Large science projects have long appreciated the ability of superconductivity to efficiently create high magnetic fields that are otherwise very costly to achieve with ordinary materials. The most successful applications outside of large science are high-field magnets for magnetic resonance imaging, laboratory magnetometers for mineral and materials characterization, filters for mobile communications, and magnetoencephalography for understanding the human brain.The stage is now set for superconductivity to make more general contributions. Humanity uses practically unthinkable amounts of energy to drive our modern way of life. Overall, global power usage has been predicted to almost double from 16.5 to 30 TW in the next four decades (2011 Equinox Summit: Energy 2030 http://wgsi.org/publications-resources).The economy with which electrons carry energy compels the continued quest for efficient superconducting power generation, energy storage, and power transmission. The growing global population requires new arable land and treatment of water, especially in remote areas, and superconductivity offers unique solutions to these problems. Exquisite detectors give warning of changes that are otherwise invisible. Prediction of climate and disasters will be helped by future supercomputer technologies that support huge amounts of data and sophisticated modeling, and with the aid of superconductivity these systems might not require the energy of a large city.We present different sections on applications that could address (or are addressing) a range of environmental issues. The Roadmap covers water purification, power distribution and storage, low-environmental impact transport, environmental sensing (particularly for the removal of unexploded munitions), monitoring the Earth's magnetic fields for earthquakes and major solar activity, and, finally, developing a petaflop supercomputer that only requires 3% of the current supercomputer power provision while being 50 times faster.Access to fresh water. With only 2.5% of the water on Earth being fresh and climate change modeling forecasting that many areas will become drier, the ability to recycle water and achieve compact water recycling systems for sewage or ground water treatment is critical. The first section (by Nishijima) points to the potential of superconducting magnetic separation to enable water recycling and reuse.Energy. The Equinox Summit held in Waterloo Canada 2011 (2011 Equinox Summit: Energy 2030 http://wgsi.org/publications-resources) identified electricity use as humanity's largest contributor to greenhouse gas emissions. Our appetite for electricity is growing faster than for any other form of energy. The communiqué from the summit said 'Transforming the ways we generate, distribute and store electricity is among the most pressing challenges facing society today.... If we want to stabilize CO2 levels in our atmosphere at 550 parts per million, all of that growth needs to be met by non-carbon forms of energy' (2011 Equinox Summit: Energy 2030 http://wgsi.org/publications-resources). Superconducting technologies can provide the energy efficiencies to achieve, in the European Union alone, 33–65% of the required reduction in greenhouse gas emissions according to the Kyoto Protocol (Hartikainen et al 2003 Supercond. Sci. Technol. 16 9

Shigehiro Nishijima; Steven Eckroad; Adela Marian; Kyeongdal Choi; Woo Seok Kim; Motoaki Terai; Zigang Deng; Jun Zheng; Jiasu Wang; Katsuya Umemoto; Jia Du; Pascal Febvre; Shane Keenan; Oleg Mukhanov; Lance D Cooley; Cathy P Foley; William V Hassenzahl; Mitsuru Izumi

2013-01-01T23:59:59.000Z

451

Temperature dependence of vortex charges in high-temperature superconductors  

Science Journals Connector (OSTI)

Using a model Hamiltonian with d-wave superconductivity and competing antiferromagnetic (AF) interactions, the temperature (T) dependence of the vortex charge in high-Tc superconductors is investigated by numerically solving the Bogoliubov–de Gennes equations. The strength of the induced AF order inside the vortex core is T dependent. The vortex charge could be negative when the AF order with sufficient strength is present at low temperatures. At higher temperatures, the AF order may be completely suppressed and the vortex charge becomes positive. A first-order-like transition in the T-dependent vortex charge is seen near the critical temperature TAF. For an underdoped sample, the spatial profiles of the induced spin-density wave and the charge-density wave orders could have stripelike structures at TTs. As a result, a vortex charge discontinuity occurs at Ts.

Yan Chen; Z. D. Wang; C. S. Ting

2003-06-03T23:59:59.000Z

452

Temperature dependence of the lower critical field and strong pinning in high-temperature superconductors  

Science Journals Connector (OSTI)

We show, within the framework of the Ginzburg-Landau theory, that both the conventional and the anomalous temperature dependence of the lower critical field observed in high-temperature superconductors may result from the flux penetration through a set of separated microdefects. Microdefects modeled by normal layers with proximity-induced superconductivity can produce drastic enhancement of the lower critical field at low temperatures and can provide strong-pinning centers. The pinning interaction between an isolated vortex and the normal layer is primarily magnetic at high temperatures. At low temperatures, magnetic interaction is reduced, due to the increase of the normal-layer coherence length.

Dragomir Davidovi? and Ljiljana Dobrosavljevi?-Gruji?

1991-02-01T23:59:59.000Z

453

Design of A Conduction-cooled 4T Superconducting Racetrack for Multi-field Coupling Measurement System  

E-Print Network [OSTI]

A conduction-cooled superconducting magnet producing a transverse field of 4 Tesla has been designed for the new generation multi-field coupling measurement system, which was used to study the mechanical behavior of superconducting samples at cryogenic temperature and intense magnetic fields. Considering experimental costs and coordinating with system of strain measurements by contactless signals (nonlinear CCD optics system), the racetrack type for the coil winding was chosen in our design, and a compact cryostat with a two-stage GM cryocooler was designed and manufactured for the superconducting magnet. The magnet was composed of a pair of flat racetrack coils wound by NbTi/Cu superconducting composite wires, a copper and stainless steel combinational form and two Bi2Sr2CaCu2Oy superconducting current leads. All the coils were connected in series and can be powered with a single power supply. The maximum central magnetic field is 4 T. In order to support the high stress and uniform thermal distribution in t...

Chen, Yuquan; Wu, Wei; Guan, Mingzhi; Wu, Beimin; Mei, Enming; Xin, Canjie

2015-01-01T23:59:59.000Z

454

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

SciTech Connect (OSTI)

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

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

2011-01-01T23:59:59.000Z

455

Development of Pre?Preg Ceramic Insulation for Superconducting Magnets  

Science Journals Connector (OSTI)

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

D. E. Codell; P. E. Fabian

2004-01-01T23:59:59.000Z

456

Proximity effect bilayer nano superconducting quantum interference devices for millikelvin magnetometry  

SciTech Connect (OSTI)

Superconducting quantum interference devices (SQUIDs) incorporating thin film nanobridges as weak links have sensitivities approaching that required for single spin detection at 4.2?K. However, due to thermal hysteresis they are difficult to operate at much lower temperatures which hinder their application to many quantum measurements. To overcome this, we have developed nanoscale SQUIDs made from titanium-gold proximity bilayers. We show that their electrical properties are consistent with a theoretical model developed for heat flow in bilayers and demonstrate that they enable magnetic measurements to be made on a sample at system temperatures down to 60 mK.

Blois, A., E-mail: a.blois@ucl.ac.uk; Rozhko, S.; Romans, E. J. [London Centre for Nanotechnology, University College London (UCL), 17-19 Gordon Street, London WC1H 0AH (United Kingdom); Hao, L.; Gallop, J. C. [National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW (United Kingdom)

2013-12-21T23:59:59.000Z

457

Analysis of the influence of the normal zone propagation velocity on the design of resistive fault current limiters  

Science Journals Connector (OSTI)

Commercial high-temperature superconducting coated conductors (HTS-CCs) have low thermal diffusivity and nonuniform critical current density. These two factors lead commercial HTS-CCs to a partial quench when they are subjected to a transport current around their average critical current (). The consequence is the appearance of localized resistive zones, and a high risk of thermal runaway can arise when HTS-CCs are used for resistive fault current limiter (RFCL) purposes. The enhancement of the normal zone propagation velocity (NZPV) of HTS-CCs is a desirable solution for achieving sufficient thermal stability while keeping the cost of RFCLs under an acceptable threshold. Even though in recent years, several valid methods to increase the NZPV have been proposed, their impact on the design of RFCLs is not clear. For this reason, we developed a one-dimensional numerical model that enables us to simulate HTS-CCs with enhanced NZPV and to study the limitation performance of a HTS-CC-based RFCL in real operating conditions. Our preliminary re sults demonstrate that the NZPV enhancement can effectively limit the needed amount of HTS-CCs with important economic benefits for the design of RFCLs.

Daniele Colangelo; Bertrand Dutoit

2014-01-01T23:59:59.000Z

458

Low temperature London penetration depth and superfluid density in Fe-based superconductors  

SciTech Connect (OSTI)

The superconducting gap symmetry of the Fe-based superconductors was studied by measurements and analysis of London penetration depth and super uid density. Tunnel diode resonator technique for these measurements was implemented in a dilution refrigerator allowing for the temperatures down to 50 mK. For the analysis of the super uid density, we used both experimental studies of Al-coated samples and original thermodynamic approach based on Rutgers relation. In three systems studied, we found that the superconducting gap at the optimal doping is best described in multi-gap full gap scenario. By performing experiments on samples with arti#12;cially introduced disorder with heavy ion irradiation, we show that evolution of the superconducting transition temperature and of the super uid density are consistent with full-gap sign changing s#6; superconducting state. The superconducting gap develops strong modulation both in the under-doped and the over-doped regimes. In the terminal hole-doped KFe{sub 2}As{sub 2}, both temperature dependence of the super uid density and its evolution with increase of the scattering rate are consistent with symmetry imposed vertical line nodes in the superconducting gap. By comparative studies of hole-doped (Ba,K)Fe{sub 2}As{sub 2} and electron-doped Ca10-3-8, we show that the superconducting gap modulation in the under-doped regime is intrinsic and is not induced by the coexisting static magnetic order.

Kim, Hyunsoo [Ames Laboratory] [Ames Laboratory

2013-05-15T23:59:59.000Z

459

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

Science Journals Connector (OSTI)

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

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

1995-09-01T23:59:59.000Z

460

ORNL Superconducting Technology Program for Electric Power Systems, Annual Report for FY 1998  

SciTech Connect (OSTI)

The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy to develop the science and technology base needed by U.S. industry for commercial development of electric power applications of high temperature superconductivity. The two major elements of this program are wire development and applications development. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from recent open literature publications, presentations, and information prepared for the FY 1998 Annual Program Review held July 20-22, 1998. Aspects of ORNL's work that were presented at the Applied Superconductivity Conference (September 1998) are included in this report, as well. This ORNL program is highly leveraged by the staff and other resources of U.S. industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to cooperative projects. Patent disclosures, working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with U.S. industry. Working together, the collaborative teams are making rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high temperature superconductor wire and wire-using systems.

Hawsey, R.A.; Murphy, A.W.

1999-04-01T23:59:59.000Z

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461

Hole superconductivity in the electron-doped superconductor Pr2?xCexCuO4  

Science Journals Connector (OSTI)

We measure the resistivity and Hall angle of the electron-doped superconductor Pr2?xCexCuO4 as a function of doping and temperature. The resistivity ?xx at temperatures 100Ktemperature behavior is doping independent over a wide doping range and even for nonsuperconducting samples. On the other hand, the transverse resistivity ?xy, or the Hall angle ?H, where cot(?H)=?xx??xy, is sensitive to both holes and electrons. Its temperature dependence is strongly influenced by doping, and cot(?H) can be used to identify optimum doping (the maximum Tc) even well above the critical temperature. These results lead to a conclusion that in electron doped cuprates holes are responsible for the superconductivity.

Y. Dagan and R. L. Greene

2007-07-11T23:59:59.000Z

462

Superconducting weak bonds at grain boundaries in MgB{sub 2}  

SciTech Connect (OSTI)

The possibility of preparing bicrystalline Josephson junctions and bolometers based on superconducting MgB{sub 2} on specially prepared bicrystalline MgO substrates is investigated. Microbridges 0.85-6.00 {mu}m in width, intersecting the bicrystalline interface, are formed in epitaxial bicrystalline MgB{sub 2} films grown on these substrates. It is found that annealing of bicrystalline samples in oxygen leads to a systematic decrease in the critical current, an increase in the temperature width of the superconducting transition region, and to an improvement of the current-voltage (IV) characteristic, which becomes close in shape to the IV characteristic of a Josephson junction. The response of such a junction to radiation at a frequency of 110 GHz with an amplitude attaining 0.5 mV is measured.

Tarasov, M. A. [Russian Academy of Sciences, Institute of Radio Engineering and Electronics (Russian Federation)], E-mail: tarasov@hitech.cplire.ru; Stepantsov, E. A. [Russian Academy of Sciences, Institute of Crystallography (Russian Federation); Naito, M.; Tsukada, A. [Tokyo University of Agriculture and Technology, Department of Applied Physics (Japan); Winkler, D.; Kalabukhov, A. S. [Chalmers University of Technology, Department of Microtechnology and Nanoscience (Sweden); Kupriyanov, M. Yu. [Moscow State University, Research Institute of Nuclear Physics (Russian Federation)

2007-10-15T23:59:59.000Z

463

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

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

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

464

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

SciTech Connect (OSTI)

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

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

1991-01-01T23:59:59.000Z

465

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

466

A study on DC hybrid three-phase fault current limiting interrupter for a power distribution system  

Science Journals Connector (OSTI)

For the purpose of protecting electric power system, many researches and developments of fault current limiters are being performed. The authors studied a dc hybrid three-phase fault current limiting interrupter (FCLI) composed of a superconducting reactor and an S/N transition element, connected in series each other. The dc hybrid type fault current limiting interrupter can limit a fault current by means of the inductance of high temperature superconducting (HTS) coil together with the normal transition of HTS bulk material (HTSB). In the case of an accident, the normal transition of the bulk material can be accelerated by the magnetic field of the HTS coil. In this paper, the dc hybrid type fault current limiting interrupter for 5.5 km long 6.6 kV–600 A power distribution system is analyzed, and performances of fault current limitation and interruption are confirmed. Moreover, a reclosing operation is discussed for this power distribution system.

Hongtian Shao; Tomoyuki Satoh; Mitsugi Yamaguchi; Satoshi Fukui; Jun Ogawa; Takao Satoh; Hiroyuki Ishikawa

2005-01-01T23:59:59.000Z

467

Magnetic order and superconductivity in RBa2Cu3Oz  

Science Journals Connector (OSTI)

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

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

1988-10-01T23:59:59.000Z

468

In situ doping control of the surface of high-temperature superconductors  

E-Print Network [OSTI]

LETTERS In situ doping control of the surface of high-temperature superconductors M. A. HOSSAIN1 to systematic studies of high- temperature superconductors, such as creating new electron- doped superconductors.1038/nphys998 Central to the understanding of high-temperature superconductivity is the evolution

Michelson, David G.

469

Energy Programs | Center for Emergent Superconductivity  

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

470

Manufacturing and Testing of Accelerator Superconducting Magnets  

E-Print Network [OSTI]

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

Rossi, L

2014-01-01T23:59:59.000Z

471