WorldWideScience

Sample records for superconducting wire applications

  1. MgB2 superconducting wires basics and applications

    CERN Document Server

    2016-01-01

    The compendium gives a complete overview of the properties of MgB2 (Magnesium Diboride), a superconducting compound with a transition temperature of Tc = 39K, from the fundamental properties to the fabrication of multifilamentary wires and to the presentation of various applications. Written by eminent researchers in the field, this indispensable volume not only discusses superconducting properties of MgB2 compounds, but also describes known preparation methods of thin films and of bulk samples obtained under high pressure methods. A unique selling point of the book is the detailed coverage of various applications based on MgB2, starting with MRI magnets and high current cables, cooled by Helium (He) vapor. High current cables cooled by liquid hydrogen are also highlighted as an interesting alternative due to the shrinking He reserves on earth. Other pertinent subjects comprise permanent magnets, ultrafine wires for space applications and wind generator projects.

  2. Composite ceramic superconducting wires for electric motor applications

    Science.gov (United States)

    Halloran, John W.

    1990-07-01

    Several types of HTSC wire have been produced and two types of HTSC motors are being built. Hundreds of meters of Ag- clad wire were fabricated from YBa2Cu3O(7-x) (Y-123) and Bi2Ca2Sr2Cu3O10 (BiSCCO). The dc homopolar motor coils are not yet completed, but multiple turns of wire have been wound on the coil bobbins to characterize the superconducting properties of coiled wire. Multifilamentary conductors were fabricated as cables and coils. The sintered polycrystalline wire has self-field critical current densities (Jc) as high as 2800 A/sq cm, but the Jc falls rapidly with magnetic field. To improve Jc, sintered YBCO wire is melt textured with a continuous process which has produced textures wire up to 0.5 meters long with 77K transport Jc above 11, 770 A/sq cm2 in self field and 2100 A/sq cm2 at 1 telsa. The Emerson Electric dc homopolar HTSC motor has been fabricated and run with conventional copper coils. A novel class of potential very powerful superconducting motors have been designed to use trapped flux in melt textures Y-123 as magnet replicas in an new type of permanent magnet motor. The stator element and part of the rotor of the first prototype machine exist, and the HTSC magnet replica segments are being fabricated.

  3. Summary of the First Generation High Temperature Superconducting Wire:Processing, Characterization and Applications

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Silver-clad (Bi,Pb)2Sr2Ca2Cu3O10+x long wires produced by powder-in-tube techniques, which have been recognized as the first generation of the High Temperature Superconducting (HTS) wires, are expected to apply widely especially in strong current applications. In this work, the processing, characterization and application of the silver-clad (Bi,Pb)2Sr2Ca2Cu3O10+x HTS wires are summarized. The HTS wires are fabricated using the combination of powder-in-tube technique, and the resulting wires are fully characterized by the means of chemical analyses, microstructural observation, electrical and magnetic measurements. The relationship among fabrication parameters, chemical and microstructural characteristics, and electrical and magnetic properties are analyzed. Applications of the HTS wires have also been introduced according to their strong current behaviors with various prototype devices made.

  4. Development of practical high temperature superconducting wire for electric power application

    Science.gov (United States)

    Hawsey, Robert A.; Sokolowski, Robert S.; Haldar, Pradeep; Motowidlo, Leszek R.

    1995-01-01

    The technology of high temperature superconductivity has gone from beyond mere scientific curiousity into the manufacturing environment. Single lengths of multifilamentary wire are now produced that are over 200 meters long and that carry over 13 amperes at 77 K. Short-sample critical current densities approach 5 x 104 A/sq cm at 77 K. Conductor requirements such as high critical current density in a magnetic field, strain-tolerant sheathing materials, and other engineering properties are addressed. A new process for fabricating round BSCCO-2212 wire has produced wires with critical current densities as high as 165,000 A/sq cm at 4.2 K and 53,000 A/sq cm at 40 K. This process eliminates the costly, multiple pressing and rolling steps that are commonly used to develop texture in the wires. New multifilamentary wires with strengthened sheathing materials have shown improved yield strengths up to a factor of five better than those made with pure silver. Many electric power devices require the wire to be formed into coils for production of strong magnetic fields. Requirements for coils and magnets for electric power applications are described.

  5. Composite conductor containing superconductive wires

    Energy Technology Data Exchange (ETDEWEB)

    Larson, W.L.; Wong, J.

    1974-03-26

    A superconductor cable substitute made by coworking multiple rods of superconductive niobium--titanium or niobium--zirconium alloy with a common copper matrix to extend the copper and rods to form a final elongated product which has superconductive wires distributed in a reduced cross-section copper conductor with a complete metallurgical bond between the normal-conductive copper and the superconductor wires contained therein is described. The superconductor cable can be in the form of a tube.

  6. Superconducting wires and fractional flux

    Science.gov (United States)

    Sá de Melo, C. A. R.

    1996-05-01

    The quantization of flux quanta in superconductors is revisited and analyzed in a new geometry. The system analyzed is a superconducting wire. The geometry is such that the superconducting wire winds N times around an insulating cylinder and that the wire has its end connected back to its beginning, thus producing an N-loop short circuited solenoid. The winding number N acts as a topological index that controls flux quantization. In this case, fractional flux quanta can be measured through the center of the insulating cylinder, provided that the cylinder radius is small enough. The Little-Parks experiment for an identical geometry is discussed. The period of oscillation of the transition temperature of the wire is found to vary as 1/N in units of flux Φ relative to the flux quantum Φ0. When a SQUID is made in such a geometry the maximal current through the SQUID varies with period Φ0/N.

  7. Introduction of CORC® wires: highly flexible, round high-temperature superconducting wires for magnet and power transmission applications

    Science.gov (United States)

    Weiss, Jeremy D.; Mulder, Tim; ten Kate, Herman J.; van der Laan, Danko C.

    2017-01-01

    Conductor on Round Core (CORC®) technology has achieved a long sought-after benchmark by enabling the production of round, multifilament, (RE)Ba2Ca3O7-x coated conductors with practical current densities for use in magnets and power applications. Recent progress, including the demonstration of engineering current density beyond 300 Amm-2 at 4.2 K and 20 T, indicates that CORC® cables are a viable conductor for next generation high field magnets. Tapes with 30 μm substrate thickness and tape widths down to 2 mm have improved the capabilities of CORC® technology by allowing the production of CORC® wires as thin as 3 mm in diameter with the potential to enhance the engineering current density further. An important benefit of the thin CORC® wires is their improved flexibility compared to thicker (7-8 mm diameter) CORC® cables. Critical current measurements were carried out on tapes extracted from CORC® wires made using 2 and 3 mm wide tape after bending the wires to various diameters from 10 to 3.5 cm. These thin wires are highly flexible and retain close to 90% of their original critical current even after bending to a diameter of 3.5 cm. A small 5-turn solenoid was constructed and measured as a function of applied magnetic field, exhibiting an engineering current density of 233 Amm-2 at 4.2 K and 10 T. CORC® wires thus form an attractive solution for applications between 4.2 and 77 K, including high-field magnets that require high current densities with small bending diameters, benefiting from a ready-to-use form (similar to NbTi and contrary to Nb3Sn wires) that does not require additional processing following coil construction.

  8. Present Status and Future Perspective of Bismuth-Based High-Temperature Superconducting Wires Realizing Application Systems

    Science.gov (United States)

    Sato, Ken-ichi; Kobayashi, Shin-ichi; Nakashima, Takayoshi

    2012-01-01

    Among a series of high-temperature superconducting materials that have been discovered to date, (Bi,Pb)2Sr2Ca2Cu3O10-x is the best candidate for superconducting wires that are long with commercial productivity, and critical current performance. In particular, the controlled overpressure (CT-OP) sintering technique gave us a 100% density of (Bi,Pb)2Sr2Ca2Cu3O10-x portion, which leads to robustness, increase in critical current, and mechanical tolerance. Many application prototypes are already verified and are being evaluated worldwide. Current leads for large magnets and magnetic billet heaters are already commercial products. Commercial applications for power cables, motors for ship propulsion and electric vehicles, and many kinds of magnets are promising in the near future.

  9. Sample of superconducting wiring (Niobium Titanium)

    CERN Multimedia

    About NbTi cable: The cable consists of 36 strands of superconducting wire, each strand has a diameter of 0.825 mm and houses 6300 superconducting filaments of niobium-titanium (Nb-Ti, a superconducting alloy). Each filament has a diameter of about 0.006 mm, i.e. 10 times smaller than a typical human hair. The filaments are embedded in a high-purity copper matrix. Copper is a normal conducting material. The filaments are in the superconductive state when the temperature is below about -263ºC (10.15 K). When the filaments leave the superconductive state, the copper acts as conductor transports the electrical current. Each strand of The NbTi cable (at superconducting state) has a current density of up to above 2000 A/mm2 at 9 T and -271ºC (2.15 K). A cable transport a current of about 13000 A at 10 T and -271ºC (2.15 K). About LHC superconducting wiring: The high magnetic fields needed for the LHC can only be reached using superconductors. At very low temperatures, superconductors have no electrical resista...

  10. Sample of superconducting wiring (Niobium Titanium)

    CERN Multimedia

    About NbTi cable: The cable consists of 36 strands of superconducting wire, each strand has a diameter of 0.825 mm and houses 6300 superconducting filaments of niobium-titanium (Nb-Ti, a superconducting alloy). Each filament has a diameter of about 0.006 mm, i.e. 10 times smaller than a typical human hair. The filaments are embedded in a high-purity copper matrix. Copper is a normal conducting material. The filaments are in the superconductive state when the temperature is below about -263ºC (10.15 K). When the filaments leave the superconductive state, the copper acts as conductor transports the electrical current. Each strand of The NbTi cable (at superconducting state) has a current density of up to above 2000 A/mm2 at 9 T and -271ºC (2.15 K). A cable transport a current of about 13000 A at 10 T and -271ºC (2.15 K). About LHC superconducting wiring: The high magnetic fields needed for the LHC can only be reached using superconductors. At very low temperatures, superconductors have no electrical resistan...

  11. Studying superconducting Nb3Sn wire

    CERN Multimedia

    AUTHOR|(CDS)2099575

    2015-01-01

    Studying superconducting Nb3Sn wire. From the current experience from LHC and HL-LHC we know that the performance requirements for Nb3Sn conductor for future circular collider are challenging and should exceed that of present state-of-the-art materials.

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

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, D

    1996-04-01

    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.

  13. Recent developments on superconducting magnesium diboride wires and tapes

    Directory of Open Access Journals (Sweden)

    S Soltanian

    2009-08-01

    Full Text Available  MgB2 wire and tape were prepared using the powder in tube and reaction in-situ technique. All samples were characterized using the XRD, SEM, TEM, as well as transport and magnetic measurements. High transport and magnetic critical current density values have been obtained for metal-clad wires and tapes. Different sheath materials have been examined, but Fe appears to be the best sheath for MgB2 superconductors. In addition to wires and tapes we also attempt to prepare superconducting coils. Results on transport Jc of solenoid coils up to 100 turns fabricated with Cu-sheathed MgB2 wires using a wind-reaction in-situ technique are reported. The results indicate that the MgB2 wires have potential for large scale applications.

  14. A New Superconducting Wire for Future Accelerators

    CERN Multimedia

    2006-01-01

    The CARE/NED project has developed a new superconducting wire that can achieve very high currents (1400 amps) at high magnetic fields (12 teslas). Cross-section of the CARE/NED wire produced by SMI. As we prepare to enter a new phase of particle physics with the LHC, technological development is a continuous process to ensure the demands of future research are met. The next generation of colliders and upgrades of the present ones will require significantly larger magnetic fields for bending and focusing the particle beams. NED (Next European Dipole) is one of the projects taking on this challenge to push technology beyond the present limit (see: More about NED). The magnets in the LHC rely on niobium titanium (NbTi) as the superconducting material, with a maximum magnetic field of 8 to 10T (tesla). In order to exceed this limitation, a different material together with the corresponding technology needs to be developed. NED is assessing the suitability of niobium tin (Nb3Sn), which has the potential to at le...

  15. Electromechanical properties of superconducting MgB{sub 2} wire

    Energy Technology Data Exchange (ETDEWEB)

    Salama, K; Zhou, Y X; Hanna, M; Alessandrini, M; Putman, P T; Fang, H [Mechanical Engineering Department and Texas Center for Superconductivity, University of Houston, Houston, TX (United States)

    2005-12-15

    The current-carrying capability of superconducting wires is degraded by stress. Therefore electromechanical properties are one of the key feedback parameters needed for progress in conductor applications. In this work, uniaxial tensile stresses and bending stresses were applied to Fe /MgB{sub 2} wires at room temperature, followed by measurement of critical current using a transport method at 4.2 K. Basic mechanical properties were calculated from the measured stress-strain characteristics. The irreversible tensile strain at which the critical current density of MgB{sub 2} wire starts to degrade was found to be 0.5%. In addition, the degradation of I{sub c} with decreasing bending diameters was found to be very rapid for wires that were deformed after the heat treatment that forms the MgB{sub 2} compound, while not much degradation of I{sub c} was found for wires that were bent before being annealed. SEM observations confirmed that cracks could be healed by post-annealing.

  16. Materials science challenges for high-temperature superconducting wire.

    Science.gov (United States)

    Foltyn, S R; Civale, L; Macmanus-Driscoll, J L; Jia, Q X; Maiorov, B; Wang, H; Maley, M

    2007-09-01

    Twenty years ago in a series of amazing discoveries it was found that a large family of ceramic cuprate materials exhibited superconductivity at temperatures above, and in some cases well above, that of liquid nitrogen. Imaginations were energized by the thought of applications for zero-resistance conductors cooled with an inexpensive and readily available cryogen. Early optimism, however, was soon tempered by the hard realities of these new materials: brittle ceramics are not easily formed into long flexible conductors; high current levels require near-perfect crystallinity; and--the downside of high transition temperature--performance drops rapidly in a magnetic field. Despite these formidable obstacles, thousands of kilometres of high-temperature superconducting wire have now been manufactured for demonstrations of transmission cables, motors and other electrical power components. The question is whether the advantages of superconducting wire, such as efficiency and compactness, can outweigh the disadvantage: cost. The remaining task for materials scientists is to return to the fundamentals and squeeze as much performance as possible from these wonderful and difficult materials.

  17. The current status of high temperature superconducting wires

    Science.gov (United States)

    Mikhailov, B. P.; Burkhanov, G. S.

    1991-12-01

    The principal technological difficulties associated with the manufacture of high temperature superconducting (HTSC) wires based on yttrium and lanthanum ceramics are briefly reviewed. It is noted that the superconducting and mechanical properties of HTSC wires or ribbons are largely determined by their microstructure. Particular attention is given to the currently used method of producing HTSC wires whereby the ceramic powder is encased in a pipe shell and then deformed by different methods, such as rolling, drawing, or pressing. The requirements for the shell material are examined, and current densities are presented for HTSC wires produced in shells of copper, silver, aluminum, nickel, stainless steel, and zirconium.

  18. Onset of Vortices in Thin Superconducting Strips and Wires

    CERN Document Server

    Aranson, I S; Shapiro, B Y

    1994-01-01

    Spontaneous nucleation and the consequent penetration of vortices into thin superconducting films and wires, subjected to a magnetic field, can be considered as a nonlinear stage of primary instability of the current-carrying superconducting state. The development of the instability leads to the formation of a chain of vortices in strips and helicoidal vortex lines in wires. The boundary of instability was obtained analytically. The nonlinear stage was investigated by simulations of the time-dependent generalized Ginzburg-Landau equation.

  19. Research Progress of MgB2 Superconducting Wires and Tapes and Superconducting Magnet Application%二硼化镁超导线带材及磁体应用研究进展

    Institute of Scientific and Technical Information of China (English)

    闫果; 王庆阳; 刘国庆; 熊晓梅; 潘熙锋; 冯勇

    2013-01-01

    Due to MgB2 superconductor has a series of advantages , like as high superconducting transition temperature Tc, simple binary crystal structure, cheap raw-materials cost, easy fabrication process of long wire and so on, it has at-tracted a lot of attentions, after discovered by Japanese scientists in 2001, and is thought as one of the most promising practical superconducting materials.Especially, it has a huge potential at the application of superconducting magnets of magnetic resonance imaging ( MRI) system with the operating conditions of 15~20K and 1~2 T.In this paper, we re-viewed the recent development of MgB2 superconducting long wires and tapes, made by Powder-In-Tube method (PIT), Continuous Tube Filling and Forming process ( CTFF) and Internal Magnesium Diffusion method ( IMD) .Research pro-gress at superconducting properties of engineering critical current density of MgB 2 superconducting wires has also been commented, and the latest studies on MgB2 superconducting magnets are reviewed.%由于具有超导转变温度(39K)较高,晶体结构简单,原材料成本低廉以及长线制备容易等一系列特点,金属间化合物二硼化镁( MgB2)超导体自2001年被日本科学家发现以来,引起人们广泛的关注,被认为是目前最有可能首先实现大规模工业应用的超导材料。尤其在制冷机工作温度(15~20 K)、较低磁场(1~2 T)条件下的医疗核磁共振成像仪( MRI)超导磁体应用上有着广泛的前景。本文主要围绕实用化 MgB2超导长线(带)制备研究而展开,重点回顾了近年来粉末套管法、连续粉末装管成型法及中心镁扩散法等MgB2超导线(带)材制备及加工方面的最新研究进展;同时综述了在 MgB2超导线带材工程临界电流密度性能改进方面的最新研究工作;最后,对近几年来 MgB2超导磁体及线圈等应用研究进展进行了回顾。

  20. Low cost, formable, high T(sub c) superconducting wire

    Science.gov (United States)

    Smialek, James L. (Inventor)

    1991-01-01

    A ceramic superconductivity part such as a wire is produced through the partial oxidation of a specially formulated copper alloy in the core. The alloys contain low level quantities of rare earth and alkaline earth dopant elements. Upon oxidation at high temperature, superconducting oxide phases are formed as a thin film.

  1. Superconducting properties of long TiN wires

    Science.gov (United States)

    Mironov, A. Yu.; Postolova, S. V.; Nasimov, D. A.

    2016-12-01

    The low-temperature transport properties of titanium nitride wires with the width comparable with or much larger than the superconducting coherence length are studied experimentally. It is shown that the reduction of the width of wires does not affect the transport properties at the temperatures above the superconducting transition temperature and electron transport in this temperature range is determined by quantum contributions to the conductivity from weak localization and electron-electron interaction. It is established that the reduction of the width of wires does not change the superconducting transition temperature but completely suppresses the topological Berezinskii-Kosterlitz-Thouless transition. It is found that the threshold magnetic field increases with a decrease in the width of wires.

  2. Superconductivity optimization and phase formation kinetics study of internal-Sn Nb{sub 3}Sn superconducting wires

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chaowu

    2007-07-15

    Superconductors Nb{sub 3}Sn wires are one of the most applicable cryogenic superconducting materials and the best choice for high-field magnets exceeding 10 T. One of the most significant utilization is the ITER project which is regarded as the hope of future energy source. The high-Cu composite designs with smaller number of sub-element and non-reactive diffusion barrier, and the RRP (Restacked Rod Process) internal-Sn technology are usually applied for the wire manufacturing. Such designed and processed wires were supplied by MSA/Alstom and WST/NIN in this research. The systematic investigation on internal-Sn superconducting wires includes the optimization of heat treatment (HT) conditions, phase formation and its relation with superconductivity, microstructure analysis, and the phase formation kinetics. Because of the anfractuosity of the configuration design and metallurgical processing, the MF wires are not sufficient for studying a sole factor effect on superconductivity. Therefore, four sets of mono-element (ME) wires with different Sn ratios and different third-element addition were designed and fabricated in order to explore the relationship between phase formation and superconducting performances, particularly the A15 layer growth kinetics. Different characterization technic have been used (magnetization measurements, neutron diffraction and SEM/TEM/EDX analysis). The A15 layer thicknesses of various ME samples were measured and carried out linear and non-linear fits by means of two model equations. The results have clearly demonstrated that the phase formation kinetics of Nb{sub 3}Sn solid-state reaction is in accordance with an n power relation and the n value is increased with the increase of HT temperature and the Sn ratio in the wire composite. (author)

  3. On topological phases in disordered p-wave superconducting wires

    Energy Technology Data Exchange (ETDEWEB)

    Rieder, Maria-Theresa

    2015-07-10

    Topological phases of matter have been the subject of intense experimental and theoretical research during the last years. Prominent examples are the Quantum Hall Effect, Topological Insulators or Topological Superconductors. The latter host special excitations, the Majorana states, at their boundaries, which can be thought of as the halves of an electron that can exist separately in this special case. These Majorana states have attracted great interest as they exhibit so-called non-Abelian braiding statistics, which could make them useful tools in the search for fault-tolerant quantum computation. In this context topologically superconducting wires are particularly useful as the Majorana states are located unambiguously at the wire's end, where they form localized end states. Topologically superconducting wires are not known to exist in nature but they can be engineered from commonly available ingredients: semiconductor or ferromagnet nano- wires and conventional superconductors. The nano-wires can inherit superconductivity by the proximity effect and can then exhibit a topologically nontrivial phase. By now, several experiments have been performed on such hybrid structures, reporting measurements that are consistent with the existence of a topologically superconducting phase in the nanowire. Most theoretical investigations on these systems, so far, have been restricted to a one-dimensional effective model: The one-dimensional p-wave superconductor, which is the prototype of a topologically superconducting wire. A nanowire, however, is in general in a quasi-one dimensional regime, with a continuous longitudinal but a quantized transverse degree of freedom. In this Thesis we study the multichannel generalization of a topologically superconducting wire by means of a two-dimensional p + ip-superconductor that is restricted to a narrow-strip geometry. Such systems can be in a topological phase, characterized by the existence of a zero-energy excitation at the

  4. Research, fabrication and applications of Bi-2223 HTS wires

    CERN Document Server

    2016-01-01

    The purpose of this book is to cover all aspects of Bi-2223 superconducting wires from fundamental research, fabrication process to applications. This book contains many chapters written by distinguished experts in the world.

  5. Processing and characterization of superconducting solenoids made of Bi-2212/Ag-alloy multifilament round wire for high field magnet applications

    Science.gov (United States)

    Chen, Peng

    As the only high temperature superconductor with round wire (RW) geometry, Bi2Sr2CaCu2O8+x (Bi-2212) superconducting wire has the advantages of being multi-filamentary, macroscopically isotropic and twistable. With overpressure (OP) processing techniques recently developed by our group at the National High Magnetic Field Laboratory (NHMFL), the engineering current density (Je) of Bi-2212 RW can be dramatically increased. For example, Je of more than 600 A/mm 2 (4.2 K and 20 T) is achieved after 100 bar OP processing. With these intrinsically beneficial properties and recent processing progress, Bi-2212 RW has become very attractive for high field magnet applications, especially for nuclear magnetic resonance (NMR) magnets and accelerator magnets etc. This thesis summarizes my graduate study on Bi-2212 solenoids for high field and high homogeneity NMR magnet applications, which mainly includes performance study of Bi-2212 RW insulations, 1 bar and OP processing study of Bi-2212 solenoids, and development of superconducting joints between Bi-2212 RW conductors. Electrical insulation is one of the key components of Bi-2212 coils to provide sufficient electrical standoff within coil winding pack. A TiO 2/polymer insulation offered by nGimat LLC was systematically investigated by differential thermal analysis (DTA), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), dielectric property measurements, and transport critical current (Ic) property measurements. About 29% of the insulation by weight is polymer. When the Bi-2212 wire is fully heat treated, this decomposes with slow heating to 400 °C in flowing O2. After the full reaction, we found that the TiO2 did not degrade the critical current properties, adhered well to the conductor, and provided a breakdown voltage of more than 100 V. A Bi-2212 RW wound solenoid coil was built using this insulation being offered by nGimat LLC. The coil resistance was constant through coil winding, polymer burn

  6. Sample of superconducting wiring  (Niobium Titanium)

    CERN Multimedia

    About NbTi cable: The cable consists of 36 strands of superconducting wire, each strand has a diameter of 0.825 mm and houses 6300 superconducting filaments of niobium-titanium (Nb-Ti, a superconducting alloy). Each filament has a diameter of about 0.006 mm, i.e. 10 times smaller than a typical human hair. The filaments are embedded in a high-purity copper matrix.  Copper is a normal conducting material. The filaments are in the superconductive state when the temperature is below about -263ºC (10.15 K). When the filaments leave the superconductive state, the copper acts as conductor transports the electrical current. Each strand of The NbTi cable (at superconducting state) has a current density of up to above 2000 A/mm2 at 9 T and -271ºC (2.15 K). A cable transport a current of about 13000 A at 10 T and -271ºC (2.15 K). About LHC superconducting wiring: The high magnetic fields needed for the LHC can only be reached using superconductors. At very low temperatures, superconductors have no electrical resis...

  7. Ex-situ manufacturing of SiC-doped MgB2 used for superconducting wire in medical device applications

    Science.gov (United States)

    Herbirowo, Satrio; Imaduddin, Agung; Sofyan, Nofrijon; Yuwono, Akhmad Herman

    2017-02-01

    Magnesium diboride (MgB2) is a superconductor material with a relatively high critical temperature. Due to its relatively high critical temperature, this material is promising and has the potential to replace Nb3Sn for wire superconducting used in many medical devices. In this work, nanoparticle SiC-doped MgB2 superconducting material has been fabricated through an ex-situ method. The doping of nanoparticle SiC by 10 and 15 wt% was conducted to analyze its effect on specific resistivity of MgB2. The experiment was started by weighing a stoichiometric amount of MgB2 and nanoparticles SiC. Both materials were mixed and grounded for 30 minutes by using an agate mortar. The specimens were then pressed into a 6 mm diameter stainless steel tube, which was then reduced until 3 mm through a wire drawing method. X-ray diffraction analysis was conducted to confirm the phase, whereas the superconductivity of the specimens was analyzed by using resistivity measurement under cryogenic magnetic system. The results indicated that the commercial MgB2 showed a critical temperature of 37.5 K whereas the SiC doped MgB2 has critical temperature of 38.3 K.

  8. Longitudinal propagation velocity of the normal zone in superconducting wires

    NARCIS (Netherlands)

    Kate, ten H.H.J.; Boschman, H.; Klundert, van de L.J.M.

    1987-01-01

    The longitudinal propagation of the normal zone in superconducting wires was experimentally investigated in order to evaluate existing analytical expressions which attempt to describe the propagation velocity in a more or less simple manner. The availability of a reliable expression is important for

  9. Superconductivity fundamentals and applications

    CERN Document Server

    Buckel, Werner

    2004-01-01

    This is the second English edition of what has become one of the definitive works on superconductivity in German -- currently in its sixth edition. Comprehensive and easy to understand, this introductory text is written especially with the non-specialist in mind. The authors, both long-term experts in this field, present the fundamental considerations without the need for extensive mathematics, describing the various phenomena connected with the superconducting state, with liberal insertion of experimental facts and examples for modern applications. While all fields of superconducting phenomena are dealt with in detail, this new edition pays particular attention to the groundbreaking discovery of magnesium diboride and the current developments in this field. In addition, a new chapter provides an overview of the elements, alloys and compounds where superconductivity has been observed in experiments, together with their major characteristics. The chapter on technical applications has been considerably expanded...

  10. Superconductivity in dense MgB2 wires.

    Science.gov (United States)

    Canfield, P C; Finnemore, D K; Bud'ko, S L; Ostenson, J E; Lapertot, G; Cunningham, C E; Petrovic, C

    2001-03-12

    MgB2 becomes superconducting just below 40 K. Whereas porous polycrystalline samples of MgB2 can be synthesized from boron powders, in this Letter we demonstrate that dense wires of MgB2 can be prepared by exposing boron filaments to Mg vapor. The resulting wires have a diameter of 160 microm, are better than 80% dense, and manifest the full chi = -1/4pi shielding in the superconducting state. Temperature-dependent resistivity measurements indicate that MgB2 is a highly conducting metal in the normal state with rho(40 K) = 0.38 microOmega cm. By using this value, an electronic mean-free path, l approximately 600 A can be estimated, indicating that MgB2 wires are well within the clean limit. Tc, Hc2(T), and Jc data indicate that MgB2 manifests comparable or better superconducting properties in dense wire form than it manifests as a sintered pellet.

  11. The Quantum Socket: Wiring for Superconducting Qubits - Part 2

    Science.gov (United States)

    Bejanin, J. H.; McConkey, T. G.; Rinehart, J. R.; Bateman, J. D.; Earnest, C. T.; McRae, C. H.; Rohanizadegan, Y.; Shiri, D.; Mariantoni, M.; Penava, B.; Breul, P.; Royak, S.; Zapatka, M.; Fowler, A. G.

    Quantum computing research has reached a level of maturity where quantum error correction (QEC) codes can be executed on linear arrays of superconducting quantum bits (qubits). A truly scalable quantum computing architecture, however, based on practical QEC algorithms, requires nearest neighbor interaction between qubits on a two-dimensional array. Such an arrangement is not possible with techniques that rely on wire bonding. To address this issue, we have developed the quantum socket, a device based on three-dimensional wires that enables the control of superconducting qubits on a two-dimensional grid. In this talk, we present experimental results characterizing this type of wiring. We will show that the quantum socket performs exceptionally well for the transmission and reflection of microwave signals up to 10 GHz, while minimizing crosstalk between adjacent wires. Under realistic conditions, we measured an S21 of -5 dB at 6 GHz and an average crosstalk of -60 dB. We also describe time domain reflectometry results and arbitrary pulse transmission tests, showing that the quantum socket can be used to control superconducting qubits.

  12. Applications of Superconductivity

    Science.gov (United States)

    Goodkind, John M.

    1971-01-01

    Presents a general review of current practical applications of the properties of superconducters. The devices are classified into groups according to the property that is of primary importance. The article is inteded as a first introduction for students and professionals. (Author/DS)

  13. Superconducting proximity effect in a mesoscopic ferromagnetic wire

    OpenAIRE

    Giroud, M.; Courtois, H.; Hasselbach, K.; Mailly, D.; Pannetier, B.

    1998-01-01

    We present an experimental study of the transport properties of a ferromagnetic metallic wire (Co) in metallic contact with a superconductor (Al). As the temperature is decreased below the Al superconducting transition, the Co resistance exhibits a significant dependence on both temperature and voltage. The differential resistance data show that the decay length for the proximity effect is much larger than we would simply expect from the exchange field of the ferromagnet.

  14. Critical current densities estimated from AC susceptibilities in proximity-induced superconducting matrix of multifilamentary wire

    Science.gov (United States)

    Akune, Tadahiro; Sakamoto, Nobuyoshi

    2009-03-01

    In a multifilamentary wire proximity-currents between filaments show a close resemblance with the inter-grain current in a high-Tc superconductor. The critical current densities of the proximity-induced superconducting matrix Jcm can be estimated from measured twist-pitch dependence of magnetization and have been shown to follow the well-known scaling law of the pinning strength. The grained Bean model is applied on the multifilamentary wire to obtain Jcm, where the filaments are immersed in the proximity-induced superconducting matrix. Difference of the superconducting characteristics of the filament, the matrix and the filament content factor give a variety of deformation on the AC susceptibility curves. The computed AC susceptibility curves of multifilamentary wires using the grained Bean model are favorably compared with the experimental results. The values of Jcm estimated from the susceptibilities using the grained Bean model are comparable to those estimated from measured twist-pitch dependence of magnetization. The applicability of the grained Bean model on the multifilamentary wire is discussed in detail.

  15. Critical current densities estimated from AC susceptibilities in proximity-induced superconducting matrix of multifilamentary wire

    Energy Technology Data Exchange (ETDEWEB)

    Akune, Tadahiro; Sakamoto, Nobuyoshi, E-mail: akune@te.kyusan-u.ac.j [Department of Electrical Engineering and Information Technology, Kyushu Sangyo University, 2-3-1 Matsukadai, Fukuoka 813-8503 (Japan)

    2009-03-01

    In a multifilamentary wire proximity-currents between filaments show a close resemblance with the inter-grain current in a high-T{sub c} superconductor. The critical current densities of the proximity-induced superconducting matrix J{sub cm} can be estimated from measured twist-pitch dependence of magnetization and have been shown to follow the well-known scaling law of the pinning strength. The grained Bean model is applied on the multifilamentary wire to obtain J{sub cm}, where the filaments are immersed in the proximity-induced superconducting matrix. Difference of the superconducting characteristics of the filament, the matrix and the filament content factor give a variety of deformation on the AC susceptibility curves. The computed AC susceptibility curves of multifilamentary wires using the grained Bean model are favorably compared with the experimental results. The values of J{sub cm} estimated from the susceptibilities using the grained Bean model are comparable to those estimated from measured twist-pitch dependence of magnetization. The applicability of the grained Bean model on the multifilamentary wire is discussed in detail.

  16. The effect of the wire design parameters on the stability of MgB{sub 2} superconducting coils

    Energy Technology Data Exchange (ETDEWEB)

    Majkic, G; Salama, K [Department of Mechanical Engineering and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-4006 (United States); Alessandrini, M; Laskaris, E T [General Electric Company, Global Research Center, Niskayuna, NY 12309 (United States)], E-mail: gmajkic@uh.edu

    2009-03-15

    The thermal stability of superconducting wires is one of the important issues for wire applications. We present a numerical study on the effect of the wire design parameters on the quench behavior of superconducting MgB{sub 2} wire employed in coils. The model considers a stack of MgB{sub 2} wires of rectangular cross section separated by insulation layers and subjected to a thermal disturbance. The problem is solved on a two-dimensional domain and employs the current sharing concept in the transition between superconducting and normal states. The effects of three design parameters in wire manufacturing are investigated. Quench behavior is compared for wires having different filling factor of superconducting filaments, different volume of copper stabilizer, and different residual resistivity ratio (RRR) values for copper. The results indicate that the quench propagation velocity (QPV) at 1.5 T is weakly affected by changes in the volume and electrical properties of copper, whereas the minimum quench energy (MQE) is strongly dependent on the RRR value of copper and can increase by a factor of nearly 2 with the RRR varying from 30 to 150. Both the MQE and QPV change remarkably by varying the MgB{sub 2} filling factor. The MQE drops by a factor of 6 and the QPV increases by a factor of 2 with the filling factor varying from 10.5% to 25%.

  17. Highly flexible, mechanically robust superconducting wire consisting of NbN-carbon-nanotube nanofibril composites

    Science.gov (United States)

    Kim, Jeong-Gyun; Kang, Haeyong; Kim, Joonggyu; Lee, Young Hee; Suh, Dongseok

    A flexible superconducting fiber is prepared by twisting carbon nanotube (CNT) sheets coated with sputter-deposited niobium nitride (NbN) layer to form the shape of yarn. Twisted CNT yarn, which has been extensively studied due to its high flexibility as well as excellent mechanical properties, and NbN, which is a superconducting material with high transition temperature (Tc) and critical magnetic field (Hc), are combined together by the deposition of NbN layer on free-standing CNT-sheet substrate followed by the biscrolling process. We tried many experimental conditions to investigate the superconducting properties of NbN-CNT yarn as a function of NbN thickness and number of CNT-sheet layers, and found out that the superconducting property of NbN on CNT-sheet can be comparable to that of NbN thin film on the normal solid substrate. In addition, the superconducting property survived even under the condition of severe mechanical deformation such as knotting. These results show the potential application of this technology as a large-scale fabrication method of flexible, mechanically robust, high performance superconducting wire. This work is supported by the Institute for Basic Science (IBS-R011-D1), and by the National Research Foundation (BSR-2013R1A1A1076063) funded by the Ministry of Science, ICT & Future Planning, Republic of Korea.

  18. High critical currents in iron-clad superconducting MgB2 wires.

    Science.gov (United States)

    Jin, S; Mavoori, H; Bower, C; van Dover, R B

    2001-05-31

    Technically useful bulk superconductors must have high transport critical current densities, Jc, at operating temperatures. They also require a normal metal cladding to provide parallel electrical conduction, thermal stabilization, and mechanical protection of the generally brittle superconductor cores. The recent discovery of superconductivity at 39 K in magnesium diboride (MgB2) presents a new possibility for significant bulk applications, but many critical issues relevant for practical wires remain unresolved. In particular, MgB2 is mechanically hard and brittle and therefore not amenable to drawing into the desired fine-wire geometry. Even the synthesis of moderately dense, bulk MgB2 attaining 39 K superconductivity is a challenge because of the volatility and reactivity of magnesium. Here we report the successful fabrication of dense, metal-clad superconducting MgB2 wires, and demonstrate a transport Jc in excess of 85,000 A cm-2 at 4.2 K. Our iron-clad fabrication technique takes place at ambient pressure, yet produces dense MgB2 with little loss of stoichiometry. While searching for a suitable cladding material, we found that other materials dramatically reduced the critical current, showing that although MgB2 itself does not show the 'weak-link' effect characteristic of the high-Tc superconductors, contamination does result in weak-link-like behaviour.

  19. High critical currents in iron-clad superconducting MgB2 wires

    Science.gov (United States)

    Jin, S.; Mavoori, H.; Bower, C.; van Dover, R. B.

    2001-05-01

    Technically useful bulk superconductors must have high transport critical current densities, Jc, at operating temperatures. They also require a normal metal cladding to provide parallel electrical conduction, thermal stabilization, and mechanical protection of the generally brittle superconductor cores. The recent discovery of superconductivity at 39K in magnesium diboride (MgB2) presents a new possibility for significant bulk applications, but many critical issues relevant for practical wires remain unresolved. In particular, MgB2 is mechanically hard and brittle and therefore not amenable to drawing into the desired fine-wire geometry. Even the synthesis of moderately dense, bulk MgB2 attaining 39K superconductivity is a challenge because of the volatility and reactivity of magnesium. Here we report the successful fabrication of dense, metal-clad superconducting MgB2 wires, and demonstrate a transport Jc in excess of 85,000Acm-2 at 4.2K. Our iron-clad fabrication technique takes place at ambient pressure, yet produces dense MgB2 with little loss of stoichiometry. While searching for a suitable cladding material, we found that other materials dramatically reduced the critical current, showing that although MgB2 itself does not show the `weak-link' effect characteristic of the high-Tc superconductors, contamination does result in weak-link-like behaviour.

  20. Electromechanical characterization of superconducting wires and tapes at 77 K

    CERN Document Server

    Bjoerstad, Roger

    The strain dependency of the critical current in state-of-the-art cuprate high-temperature superconductors (HTS) has been characterized. A universal test machine (UTM) combined with a critical current measurement system has been used to characterize the mechanical and the superconducting properties of conductors immersed in an open liquid nitrogen dewar. A set-up has been developed in order to perform simultaneous measurements of the superconductor lattice parameter changes, critical current, as well as the stress and strain at 77 K in self-field in a high energy synchrotron beamline. The HTS tapes and wires studied were based on YBCO, Bi-2223 and Bi-2212. The YBCO tapes were produced by SuperPower and American Superconductors (AMSC). Two types of Bi-2223 tapes, HT and G, were produced by Sumitomo Electric Industries (SEI). The Bi-2212 wires were produced by Oxford Superconducting Technology (OST) using Nexans granulate precursor, before undergoing a specialized over pressure (OP) processing and heat treatmen...

  1. Wire metamaterials: physics and applications.

    Science.gov (United States)

    Simovski, Constantin R; Belov, Pavel A; Atrashchenko, Alexander V; Kivshar, Yuri S

    2012-08-16

    The physics and applications of a broad class of artificial electromagnetic materials composed of lattices of aligned metal rods embedded in a dielectric matrix are reviewed. Such structures are here termed wire metamaterials. They appear in various settings and can operate from microwaves to THz and optical frequencies. An important group of these metamaterials is a wire medium possessing extreme optical anisotropy. The study of wire metamaterials has a long history, however, most of their important and useful properties have been revealed and understood only recently, especially in the THz and optical frequency ranges where the wire media correspond to the lattices of microwires and nanowires, respectively. Another group of wire metamaterials are arrays and lattices of nanorods of noble metals whose unusual properties are driven by plasmonic resonances. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Superconducting bearings for flywheel applications

    DEFF Research Database (Denmark)

    Abrahamsen, A.B.

    2001-01-01

    A literature study on the application of superconducting bearings in energy storage flywheel systems. The physics of magnetic levitation and superconductors are presented in the first part of the report, followed by a discussion of the literature found onthe applications of superconducting bearings...

  3. RAPID COMMUNICATION: High performance superconducting wire in high applied magnetic fields via nanoscale defect engineering

    Science.gov (United States)

    Wee, Sung Hun; Goyal, Amit; Zuev, Yuri L.; Cantoni, Claudia

    2008-09-01

    High temperature superconducting (HTS) wires capable of carrying large critical currents with low dissipation levels in high applied magnetic fields are needed for a wide range of applications. In particular, for electric power applications involving rotating machinery, such as large-scale motors and generators, a high critical current, Ic, and a high engineering critical current density, JE, in applied magnetic fields in the range of 3-5 Tesla (T) at 65 K are required. In addition, exceeding the minimum performance requirements needed for these applications results in a lower fabrication cost, which is regarded as crucial to realize or enable many large-scale bulk applications of HTS materials. Here we report the fabrication of short segments of a potential superconducting wire comprised of a 4 µm thick YBa2Cu3O7-δ (YBCO) layer on a biaxially textured substrate with a 50% higher Ic and JE than the highest values reported previously. The YBCO film contained columns of self-assembled nanodots of BaZrO3 (BZO) roughly oriented along the c-axis of YBCO. Although the YBCO film was grown at a high deposition rate, three-dimensional self-assembly of the insulating BZO nanodots still occurred. For all magnetic field orientations, minimum Ic and JE at 65 K, 3 T for the wire were 353 A cm-1 and 65.4 kA cm-2, respectively.

  4. High-performance dense MgB2 superconducting wire fabricated from mechanically milled powder

    Science.gov (United States)

    Kodama, Motomune; Suzuki, Takaaki; Tanaka, Hideki; Okishiro, Kenji; Okamoto, Kazutaka; Nishijima, Gen; Matsumoto, Akiyoshi; Yamamoto, Akiyasu; Shimoyama, Jun-ichi; Kishio, Kohji

    2017-04-01

    Owing to the relatively high critical temperature and the low manufacturing cost, MgB2 superconducting wires are promising for liquid helium-free superconducting applications. Today, commercially available MgB2 wires are manufactured by either an in situ or ex situ powder-in-tube process, the in situ process being more effective to obtain high critical current density. In in situ-processed wires, however, the critical current density is seriously suppressed by the high porosity of MgB2 filaments. To resolve this problem, we propose an innovative method of using precursor powder prepared by mechanical milling of magnesium, boron, and coronene powders. This precursor powder has a metal–matrix–composite structure, in which boron particles are dispersed in a magnesium matrix. The plastic deformation of the precursor powder through wire processing leads to compact packing, and a dense MgB2 filament is generated after heat treatment. As a result, the limitation of critical current density that occurs for the typical in situ process is overcome, and the practical critical current density of 103 A mm‑2 is obtained at 10 K and 6.1 T, at 15 K and 4.8 T, and at 20 K and 3.3 T.

  5. Overview of Superconductivity and Challenges in Applications

    Science.gov (United States)

    Flükiger, Rene

    2012-01-01

    Considerable progress has been achieved during the last few decades in the various fields of applied superconductivity, while the related low temperature technology has reached a high level. Magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) are so far the most successful applications, with tens of thousands of units worldwide, but high potential can also be recognized in the energy sector, with high energy cables, transformers, motors, generators for wind turbines, fault current limiters and devices for magnetic energy storage. A large number of magnet and cable prototypes have been constructed, showing in all cases high reliability. Large projects involving the construction of magnets, solenoids as well as dipoles and quadrupoles are described in the present book. A very large project, the LHC, is currently in operation, demonstrating that superconductivity is a reliable technology, even in a device of unprecedented high complexity. A project of similar complexity is ITER, a fusion device that is presently under construction. This article starts with a brief historical introduction to superconductivity as a phenomenon, and some fundamental properties necessary for the understanding of the technical behavior of superconductors are described. The introduction of superconductivity in the industrial cycle faces many challenges, first for the properties of the base elements, e.g. the wires, tapes and thin films, then for the various applied devices, where a number of new difficulties had to be resolved. A variety of industrial applications in energy, medicine and communications are briefly presented, showing how superconductivity is now entering the market.

  6. Development of a persistent superconducting joint between Bi-2212/Ag-alloy multifilamentary round wires

    Science.gov (United States)

    Chen, Peng; Trociewitz, Ulf P.; Davis, Daniel S.; Bosque, Ernesto S.; Hilton, David K.; Kim, Youngjae; Abraimov, Dmytro V.; Starch, William L.; Jiang, Jianyi; Hellstrom, Eric E.; Larbalestier, David C.

    2017-02-01

    Superconducting joints are one of the key components needed to make Ag-alloy clad Bi2Sr2CaCu2O8+x (Bi-2212) superconducting round wire (RW) successful for high-field, high-homogeneity magnet applications, especially for nuclear magnetic resonance magnets in which persistent current mode operation is highly desired. In this study, a procedure for fabricating superconducting joints between Bi-2212 RWs during coil reaction was developed. Melting temperatures of Bi-2212 powder with different amounts of Ag addition were investigated by differential thermal analysis so as to provide information for selecting the proper joint matrix. Test joints of 1.3 mm dia. wires heat treated in 1 bar flowing oxygen using the typical partial melt Bi-2212 heat treatment (HT) had transport critical currents I c of ˜900 A at 4.2 K and self-field, decreasing to ˜480 A at 14 T evaluated at 0.1 μV cm-1 at 4.2 K. Compared to the I c of the open-ended short conductor samples with identical 1 bar HT, the I c values of the superconducting joint are ˜20% smaller than that of conductor samples measured in parallel field but ˜20% larger than conductor samples measured in perpendicular field. Microstructures examined by scanning electron microscopy clearly showed the formation of a superconducting Bi-2212 interface between the two Bi-2212 RWs. Furthermore, a Bi-2212 RW closed-loop solenoid with a superconducting joint heat treated in 1 bar flowing oxygen showed an estimated joint resistance below 5 × 10-12 Ω based on its field decay rate. This value is sufficiently low to demonstrate the potential for persistent operation of large inductance Bi-2212 coils.

  7. Fabrication and superconducting properties of a simple-structured jelly-roll Nb{sub 3}Al wire with low-temperature heat-treatment

    Energy Technology Data Exchange (ETDEWEB)

    Cui, L.J. [National Engineering Laboratory for Superconducting Materials (NELSM), Western Superconducting Technologies (WST) Co. Ltd., Xi’an 710018 (China); Yan, G., E-mail: gyan@c-wst.com [National Engineering Laboratory for Superconducting Materials (NELSM), Western Superconducting Technologies (WST) Co. Ltd., Xi’an 710018 (China); Pan, X.F. [National Engineering Laboratory for Superconducting Materials (NELSM), Western Superconducting Technologies (WST) Co. Ltd., Xi’an 710018 (China); Zhang, P.X. [National Engineering Laboratory for Superconducting Materials (NELSM), Western Superconducting Technologies (WST) Co. Ltd., Xi’an 710018 (China); Northwest Institute for Nonferrous Metal Research (NIN), Xi’an 710016 (China); Qi, M. [Northwest Institute for Nonferrous Metal Research (NIN), Xi’an 710016 (China); Liu, X.H.; Feng, Y. [National Engineering Laboratory for Superconducting Materials (NELSM), Western Superconducting Technologies (WST) Co. Ltd., Xi’an 710018 (China); Chen, Y.L.; Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Superconductivity and New Energy R& D Center, Southwest Jiaotong University (SWJTU), Chengdu 610031 (China)

    2015-06-15

    Highlights: • Nb{sub 3}Al superconducting wires with Cu-matrix and different filament numbers were prepared by the jelly-roll method. • The length of 18-cores Nb{sub 3}Al superconducting wire reaches 100 m without any breakage and intermediate anneal. • This wire has the uniform filament-shapes and fine long-wire homogeneity. • This Nb{sub 3}Al long wire has the T{sub c} of 13.4 K and J{sub c} of 4.7 × 10{sup 4} A/cm{sup 2} at 4.2 K and 12 T. - Abstract: With extremely high critical current density (J{sub c}) and excellent strain tolerance, Nb{sub 3}Al superconductor is considered as an alternative to Nb{sub 3}Sn for application of high-field magnets. However, owing to their complex structure, Nb{sub 3}Al superconducting wires can hardly meet the requirement of engineering application at present. In this work, a novel simple-structured Nb{sub 3}Al superconducting wires with Cu-matrix and different filament numbers were prepared by the conventional jelly-roll method, as well as a heat-treatment of 800–850 °C for 20–50 h. The results show that a 18-filament superconducting wire with length longer than 100 m can be successfully prepared by this method, and also this Nb{sub 3}Al long wire has the T{sub c} of 13.4 K and J{sub c} of 4.7 × 10{sup 4} A/cm{sup 2} at 4.2 K and 12 T. These suggest that with further optimization, the simple-structured Nb{sub 3}Al superconducting wires are very promising to fabricate the km-grade long wires to meet the requirement of engineering application.

  8. Finite element modeling of the powder-in- tube process for manufacture of BSCCO-2212 superconducting wires

    Science.gov (United States)

    Shah, R.; Tangrila, S.; Rachakonda, S.; Thirukkonda, M.

    1995-12-01

    High-temperature superconductors have recently attracted a great deal of attention owing to their potential use in a variety of applications including power generators, superconducting magnets for mine sweepers or ship propulsion motors, and magnetic levitation transportation systems. The powder-in-tube (PIT) process has emerged as one of the most promising and economically feasible techniques to produce long lengths high-Tc oxide based superconducting wires. The PIT method involves multi-pass wire drawing followed by rolling and heat treatment. This work focuses on the development of finite element models to simulate the PIT drawing process for fabrication of silver sheathed Bi-2212 superconducting wires. The numerical models were used to predict the density of the oxide powder, the wire drawing forces, and the silver-oxide ratio during drawing. A cap-type pressure dependent constitutive equation was implemented in the model to simulate the powder behavior. The model incorporated experimentally obtained material data for the silver and powder. Data from wire drawing experiments were used to verify model predictions.

  9. Method of forming low cost, formable High T(subc) superconducting wire

    Science.gov (United States)

    Smialek, James L. (Inventor)

    1989-01-01

    A ceramic superconductivity part, such as a wire, is produced through the partial oxidation of a specially formulated copper alloy in a core. The alloys contains low level of quantities of rare earth and alkaline earth dopant elements. Upon oxidation at high temperatures, and superconducting oxide phases are formed as a thin film.

  10. Design and comparative analysis of 10 MW class superconducting wind power generators according to different types of superconducting wires

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Hae-Jin, E-mail: haejin90@changwon.ac.kr [Changwon National University, 55306 Sarim-dong, Changwon 641-773 (Korea, Republic of); Kim, Gyeong-Hun; Kim, Kwangmin; Park, Minwon [Changwon National University, 55306 Sarim-dong, Changwon 641-773 (Korea, Republic of); Yu, In-Keun, E-mail: yuik@changwon.ac.kr [Changwon National University, 55306 Sarim-dong, Changwon 641-773 (Korea, Republic of); Kim, Jong-Yul [Korea Electrotechnology Research Institute, Changwon 641-120 (Korea, Republic of)

    2013-11-15

    Highlights: •10 MW SC wind power generators are designed using different types of SC wires. •SCSGs using YBCO and Bi-2223 wires are optimized by the modified Taguchi method. •The results demonstrate a proper type of SC wire for the optimal design of SCSG. -- Abstract: Wind turbine concepts can be classified into the geared type and the gearless type. The gearless type wind turbine is more attractive due to advantages of simplified drive train and increased energy yield, and higher reliability because the gearbox is omitted. In addition, this type resolves the weight issue of the wind turbine with the light weight of gearbox. However, because of the low speed operation, this type has disadvantage such as the large diameter and heavy weight of generator. Super-Conducting (SC) wind power generator can reduce the weight and volume of a wind power system. Properties of superconducting wire are very different from each company. This paper considers the design and comparative analysis of 10 MW class SC wind power generators according to different types of SC wires. Super-Conducting Synchronous Generators (SCSGs) using YBCO and Bi-2223 wires are optimized by an optimal method. The magnetic characteristics of the SCSGs are investigated using the finite elements method program. The optimized specifications of the SCSGs are discussed in detail, and the optimization processes can be used effectively to develop large scale wind power generation systems.

  11. Industrial Large Scale Applications of Superconductivity -- Current and Future Trends

    Science.gov (United States)

    Amm, Kathleen

    2011-03-01

    Since the initial development of NbTi and Nb3Sn superconducting wires in the early 1960's, superconductivity has developed a broad range of industrial applications in research, medicine and energy. Superconductivity has been used extensively in NMR low field and high field spectrometers and MRI systems, and has been demonstrated in many power applications, including power cables, transformers, fault current limiters, and motors and generators. To date, the most commercially successful application for superconductivity has been the high field magnets required for magnetic resonance imaging (MRI), with a global market well in excess of 4 billion excluding the service industry. The unique ability of superconductors to carry large currents with no losses enabled high field MRI and its unique clinical capabilities in imaging soft tissue. The rapid adoption of high field MRI with superconducting magnets was because superconductivity was a key enabler for high field magnets with their high field uniformity and image quality. With over 30 years of developing MRI systems and applications, MRI has become a robust clinical tool that is ever expanding into new and developing markets. Continued innovation in system design is continuing to address these market needs. One of the key questions that innovators in industrial superconducting magnet design must consider today is what application of superconductivity may lead to a market on the scale of MRI? What are the key considerations for where superconductivity can provide a unique solution as it did in the case of MRI? Many companies in the superconducting industry today are investigating possible technologies that may be the next large market like MRI.

  12. Novel Wiring Technologies for Aerospace Applications

    Science.gov (United States)

    Gibson, Tracy L.; Parrish, Lewis M.

    2014-01-01

    Because wire failure in aerospace vehicles could be catastrophic, smart wiring capabilities have been critical for NASA. Through the years, researchers at Kennedy Space Center (KSC) have developed technologies, expertise, and research facilities to meet this need. In addition to aerospace applications, NASA has applied its knowledge of smart wiring, including self-healing materials, to serve the aviation industry. This webinar will discuss the development efforts of several wiring technologies at KSC and provide insight into both current and future research objectives.

  13. Superconductivity basics and applications to magnets

    CERN Document Server

    Sharma, R G

    2015-01-01

    This book presents the basics and applications of superconducting magnets. It explains the phenomenon of superconductivity, theories of superconductivity, type II superconductors and high-temperature cuprate superconductors. The main focus of the book is on the application to superconducting magnets to accelerators and fusion reactors and other applications of superconducting magnets. The thermal and electromagnetic stability criteria of the conductors and the present status of the fabrication techniques for future magnet applications are addressed. The book is based on the long experience of the author in studying superconducting materials, building magnets and numerous lectures delivered to scholars. A researcher and graduate student will enjoy reading the book to learn various aspects of magnet applications of superconductivity. The book provides the knowledge in the field of applied superconductivity in a comprehensive way.

  14. Fabrication of Chemically Doped, High Upper Critical Field Magnesium Diboride Superconducting Wires

    Energy Technology Data Exchange (ETDEWEB)

    Marzik, James, V.

    2005-10-13

    Controlled chemical doping of magnesium diboride (MgB2) has been shown to substantially improve its superconducting properties to the levels required for high field magnets, but the doping is difficult to accomplish through the usual route of solid state reaction and diffusion. Further, superconducting cables of MgB2 are difficult to fabricate because of the friable nature of the material. In this Phase I STTR project, doped and undoped boron fibers were made by chemical vapor deposition (CVD). Several >100m long batches of doped and undoped fiber were made by CVD codeposition of boron plus dopants. Bundles of these fibers infiltrated with liquid magnesium and subsequently converted to MgB2 to form Mg-MgB2 metal matrix composites. In a parallel path, doped boron nano-sized powder was produced by a plasma synthesis technique, reacted with magnesium to produce doped MgB2 superconducting ceramic bodies. The doped powder was also fabricated into superconducting wires several meters long. The doped boron fibers and powders made in this program were fabricated into fiber-metal composites and powder-metal composites by a liquid metal infiltration technique. The kinetics of the reaction between boron fiber and magnesium metal was investigated in fiber-metal composites. It was found that the presence of dopants had significantly slowed the reaction between magnesium and boron. The superconducting properties were measured for MgB2 fibers and MgB2 powders made by liquid metal infiltration. Properties of MgB2 products (Jc, Hc2) from Phase I are among the highest reported to date for MgB2 bulk superconductors. Chemically doped MgB2 superconducting magnets can perform at least as well as NbTi and NbSn3 in high magnetic fields and still offer an improvement over the latter two in terms of operating temperature. These characteristics make doped MgB2 an effective material for high magnetic field applications, such as magnetic confined fusion, and medical MRI devices. Developing

  15. Superconducting materials for large scale applications

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-05-06

    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.

  16. Metallurgical Characterization of Niobium/Tin Superconducting Multifilamentary Wires.

    Science.gov (United States)

    1983-03-31

    bronze phases and substantial interfacial shear stress between these phases being developed during both the wire drawing and anneal cycle operations. The...porosity pit has not fully cohered to the matrix in the extrusion process steps, then the flow of the bronze at the pit site during wire drawing is...stress of the materials being drawn, satisfactory wire drawing (5)is possible . It Is possible that for about 10% reduction in area passes of the

  17. Elastic anisotropy in multifilament Nb$_3$Sn superconducting wires

    CERN Document Server

    Scheuerlein, C; Alknes, P; Arnau, G; Bjoerstad, R; Bordini, B

    2015-01-01

    The elastic anisotropy caused by the texture in the Nb3Sn filaments of PIT and RRP wires has been calculated by averaging the estimates of Voigt and Reuss, using published Nb3Sn single crystal elastic constants and the Nb3Sn grain orientation distribution determined in both wire types by Electron Backscatter Diffraction. At ambient temperature the calculated Nb3Sn E-moduli in axial direction in the PIT and the RRP wire are 130 GPa and 140 GPa, respectively. The calculated E-moduli are compared with tensile test results obtained for the corresponding wires and extracted filament bundles.

  18. Fabrication of Nb{sub 3}Al superconducting wires by utilizing the mechanically alloyed Nb(Al){sub ss} supersaturated solid-solution with low-temperature annealing

    Energy Technology Data Exchange (ETDEWEB)

    Pan, X.F. [National Engineering Laboratory for Superconducting Material, Western Superconducting Technologies (WST) Co., Ltd., Xi’an 710018 (China); Superconducting Materials Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); Yan, G., E-mail: gyan@c-nin.com [National Engineering Laboratory for Superconducting Material, Western Superconducting Technologies (WST) Co., Ltd., Xi’an 710018 (China); Superconducting Materials Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); Qi, M. [Superconducting Materials Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); Cui, L.J. [National Engineering Laboratory for Superconducting Material, Western Superconducting Technologies (WST) Co., Ltd., Xi’an 710018 (China); Chen, Y.L.; Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity and New Energy R and D Center, Southwest Jiaotong University, Chengdu 610031 (China); Li, C.S. [Superconducting Materials Center, Northwest Institute for Nonferrous Metal Research, Xi’an 710016 (China); Liu, X.H. [National Engineering Laboratory for Superconducting Material, Western Superconducting Technologies (WST) Co., Ltd., Xi’an 710018 (China); Feng, Y.; Zhang, P.X. [National Engineering Laboratory for Superconducting Material, Western Superconducting Technologies (WST) Co., Ltd., Xi’an 710018 (China); Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity and New Energy R and D Center, Southwest Jiaotong University, Chengdu 610031 (China); Liu, H.J. [Institute of Plasma Physics, Chinese Academy of Sciences (CAS), Hefei 230031 (China); and others

    2014-07-15

    Highlights: • This paper reported superconducting properties of the powder-in-tube Nb{sub 3}Al wires. • The Nb{sub 3}Al wires were made by using Nb(Al){sub ss} supersaturated solid solution powders. • The Cu-matrix Nb{sub 3}Al superconducting wires have been successfully fabricated. • The transport J{sub c} of Nb{sub 3}Al wires at 4.2 K, 10 T is up to 12,700 A/cm{sup 2}. - Abstract: High-performance Nb{sub 3}Al superconducting wire is a promising candidate to the application of high-field magnets. However, due to the production problem of km-grade wires that are free from low magnetic field instability, the Nb{sub 3}Al wires made by rapid heating, quenching and transformation (RHQT) are still not available to the large-scale engineering application. In this paper, we reported the properties of the in situ powder-in-tube (PIT) Nb{sub 3}Al superconducting wires, which were made by using the mechanically alloyed Nb(Al){sub ss} supersaturated solid solution, as well as the low temperature heat-treatment at 800 °C for 10 h. The results show that Nb{sub 3}Al superconductors in this method possess very fine grains and well superconducting properties, though a little of Nb{sub 2}Al and Nb impurities still keep being existence at present work. At the Nb{sub 3}Al with a nominal 26 at.% Al content, the onset T{sub c} reaches 15.8 K. Furthermore, a series of Nb{sub 3}Al wires and tapes with various sizes have been fabricated; for the 1.0 mm-diameter wire, the J{sub c} at 4.2 K, 10 T and 14 T have achieved 12,700 and 6900 A/cm{sup 2}, respectively. This work suggests it is possible to develop high-performance Cu-matrix Nb{sub 3}Al superconducting wires by directly using the Nb(Al){sub ss} supersaturated solid-solution without the complex RHQT heat-treatment process.

  19. Over Current Properties of HTC Superconducting Wire Cooled by Liquid Hydrogen

    Science.gov (United States)

    Shirai, Yasuyuki; Kobayashi, Hiroto; Takegami, Taiki; Hikawa, Kyosuke; Shiotsu, Masahiro; Tatsumoto, Hideki; Naruo, Yoshihiro; Kobayashi, Hiroaki; Inatani, Yoshifumi; Kinoshita, Katsuhiko

    An experimental setup which can energize superconducting wires immersed in LH2 was designed and made. Over current tests were carried out using MgB2 wire. Critical current and resistivity of a test MgB2 wire submerged in liquid hydrogen were measured for exponentially increasing heat input, while the transport current exceeded the critical current. The resistivity of the conductor was obtained as a function of current and the temperature of the conductor by using the transient heating method. The distribution ratio of the current through the superconductor and the sheath, and the resistivity of the MgB2 conductor itself were estimated.

  20. Analysis of Mechanical Stresses/Strains in Superconducting Wire

    Science.gov (United States)

    Barry, Matthew; Chen, Jingping; Zhai, Yuhu

    2016-10-01

    The optimization of superconducting magnet performance and development of high-field superconducting magnets will greatly impact the next generation of fusion devices. A successful magnet development, however, relies deeply on the understanding of superconducting materials. Among the numerous factors that impact a superconductor's performance, mechanical stress is the most important because of the extreme operation temperature and large electromagnetic forces. In this study, mechanical theory is used to calculate the stresses/strains in typical superconducting strands, which consist of a stabilizer, a barrier, a matrix and superconducting filaments. Both thermal loads and mechanical loads are included in the analysis to simulate operation conditions. Because this model simulates the typical architecture of major superconducting materials, such as Nb3Sn, MgB2, Bi-2212 etc., it provides a good overall picture for us to understand the behavior of these superconductors in terms of thermal and mechanical loads. This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship (SULI) program.

  1. Design and comparative analysis of 10 MW class superconducting wind power generators according to different types of superconducting wires

    Science.gov (United States)

    Sung, Hae-Jin; Kim, Gyeong-Hun; Kim, Kwangmin; Park, Minwon; Yu, In-Keun; Kim, Jong-Yul

    2013-11-01

    Wind turbine concepts can be classified into the geared type and the gearless type. The gearless type wind turbine is more attractive due to advantages of simplified drive train and increased energy yield, and higher reliability because the gearbox is omitted. In addition, this type resolves the weight issue of the wind turbine with the light weight of gearbox. However, because of the low speed operation, this type has disadvantage such as the large diameter and heavy weight of generator. Super-Conducting (SC) wind power generator can reduce the weight and volume of a wind power system. Properties of superconducting wire are very different from each company. This paper considers the design and comparative analysis of 10 MW class SC wind power generators according to different types of SC wires. Super-Conducting Synchronous Generators (SCSGs) using YBCO and Bi-2223 wires are optimized by an optimal method. The magnetic characteristics of the SCSGs are investigated using the finite elements method program. The optimized specifications of the SCSGs are discussed in detail, and the optimization processes can be used effectively to develop large scale wind power generation systems.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    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.

  3. Microstructural and Superconducting Properties of V-Doped MgB2 Bulk and Wires

    Science.gov (United States)

    Castillo, O. E.; Sastry, P. V. P. S. S.; Trociewitz, B.; Trociewitz, U. P.; Schwartz, J.

    2004-06-01

    Studies of the effects of doping MgB2 bulk and Fe-clad wires with V are presented. Samples of composition Mg1-xVxB2 (x = 0.0, 0.05, 0.10, 0.15) have been investigated to understand the role of V doping on the phase formation, microstructure and superconducting properties. Fe-clad wires were fabricated by groove rolling and cold drawing. The superconducting transition temperature remained constant at about 39 K for all the compositions studied. Energy dispersive x-ray (EDX) analysis confirmed the presence of V in the superconducting phase. Enhancement of magnetization hysteresis loop widths indicates an improvement in flux pinning for V-doped samples. Studies on the variation of maximum reaction temperatures suggest that the optimum reaction temperature varies with V content. The optimum reaction temperature also depended on the wire diameter with the larger wires requiring higher reaction temperature. The transport critical current densities measured for groove-rolled wires were in the range of 1.0 - 1.4 × 105 A/cm2.

  4. Superconducting characteristics of short MgB2 wires of long level sensor for liquid hydrogen

    Science.gov (United States)

    Takeda, M.; Inoue, Y.; Maekawa, K.; Matsuno, Y.; Fujikawa, S.; Kumakura, H.

    2015-12-01

    To establish the worldwide storage and marine transport of hydrogen, it is important to develop a high-precision and long level sensor, such as a superconducting magnesium diboride (MgB2) level sensor for large liquid hydrogen (LH2) tanks on board ships. Three 1.7- m-long MgB2 wires were fabricated by an in situ method, and the superconducting characteristics of twenty-four 20-mm-long MgB2 wires on the 1.7-m-long wires were studied. In addition, the static level-detecting characteristics of five 500-mm-long MgB2 level sensors were evaluated under atmospheric pressure.

  5. Voltage plateaus on V( I) curves of long quasi-one-dimensional superconducting wires (without microwave irradiation)

    Science.gov (United States)

    Kuznetsov, V. I.; Firsov, A. A.

    2016-11-01

    Segments of an almost constant voltage (plateaus) on the V( I) curves of long quasi-one-dimensional superconducting aluminum wires placed in a magnetic field are found slightly below T c, which are unexpected at the parameters and geometry considered in this work. These plateaus are assumingly attributed to subharmonics of the superconducting gap and are due to multiple Andreev reflection and strong quasiparticle heating, which occur in the nonequilibrium region of a wire. The plateaus indicate the coexistence of superconductivity and dissipation in these wires. These results cannot be described by the existing theories.

  6. Neutron irradiation effects on superconducting wires and insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Arata [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)], E-mail: nishi-a@nifs.ac.jp; Takeuchi, Takao [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Nishijima, Shigehiro [Graduate School of Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nishijima, Gen; Shikama, Tatsuo [Tohoku University, 2-1-1 Katahira, Aoba, Sendai, Miyagi 980-8577 (Japan); Ochiai, Kentaro [Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai, Naka, Ibaraki 319-1195 (Japan); Koizumi, Norikiyo [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

    2009-06-15

    On the progress of the Deuterium-Deuterium (D-D) or Deuterium-Tritium (D-T) burning plasma devices, the importance of neutron irradiation on superconducting magnet materials increases and the data base is desired to design the next generation devices. To carry out the investigations on the effect of neutron irradiation, neutron irradiation fields are required together with post-irradiation test facilities. In these several years, a collaboration network of neutron irradiation effect on superconducting magnet materials has been constructed. 14 MeV neutron irradiation was carried out at Fusion Neutronics Sources (FNS) in Japan Atomic Energy Agency (JAEA) and fission neutron irradiation was performed at JRR-3 in JAEA. After the irradiation, the Nb{sub 3}Sn, NbTi and Nb{sub 3}Al samples were sent to High Field Laboratory for Superconducting Materials (HFLSM) in Tohoku University and the superconducting properties were evaluated with 28 T hybrid magnet. Also, the organic insulation materials are considered to be weaker than superconducting materials against neutron irradiation and cyanate ester resin composite was fabricated and tested at the fission reactor. One clear result on Nb{sub 3}Sn was the property change of Nb{sub 3}Sn by 14 MeV neutron irradiation over 13 T. The critical current was increased by 1.4 times around 13 T but the increment of the critical current became almost zero at higher magnetic fields and the critical magnetic field of the irradiated sample showed almost the same as non-irradiated one.

  7. Bending strain tolerance of MgB2 superconducting wires

    Science.gov (United States)

    Kováč, P.; Hušek, I.; Melišek, T.; Kulich, M.; Kopera, L.

    2016-04-01

    This work describes the strain tolerance of MgB2 superconductors subjected to variable bending stresses. Bending of MgB2 wire was done at room temperature in different modes: (i) direct bending of straight annealed samples to variable diameters and by (ii) indirect bending by straightening of bent and annealed samples. I c-bending strain characteristics of samples made by in situ PIT and by the internal magnesium diffusion (IMD) process were measured at 4.2 K. The results show a good agreement between the direct and indirect bending mode, which allows easier estimation of limits important for the winding process of MgB2 superconductors with brittle filaments. A comparison of MgB2 wires made by in situ PIT and IMD processes showed improved strain tolerance for IMD due to better grain connectivity the low annealing temperature, which does not appear to reduce the mechanical strength of sheath material.

  8. Structural and low-field magnetic characterization of superconducting MgB{sub 2} wires

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, A. [Faculty of Sciences, Department of Physics, Ankara University, 06100-Tandogan/Ankara (Turkey); Okur, S. [Izmir Institute of Technology, Department of Physics, 35437-Urla/Izmir (Turkey); Gueclue, N. [Faculty of Sciences and Art, Department of Physics, Gaziosmanpasa University, 60100-Taslicftlik/Tokat (Turkey)]. E-mail: guclu06@hotmail.com; Koelemen, U. [Faculty of Sciences and Art, Department of Physics, Gaziosmanpasa University, 60100-Taslicftlik/Tokat (Turkey); Uzun, O. [Faculty of Sciences and Art, Department of Physics, Gaziosmanpasa University, 60100-Taslicftlik/Tokat (Turkey); Oezyuezer, L. [Izmir Institute of Technology, Department of Physics, 35437-Urla/Izmir (Turkey); Gencer, A. [Faculty of Sciences, Department of Physics, Ankara University, 06100-Tandogan/Ankara (Turkey)

    2004-10-01

    Superconducting MgB{sub 2} composite wires were prepared by packing blend of MgB{sub 2} inside of Cu tubes using powder in tube (PIT) method. The produced samples of the wires were then characterised by using SEM, XRD and AC susceptibility measurements. The measured fundamental susceptibility is compared with Bean model. We have obtained an empirical functions for the penetration field H{sub p} = H{sub {alpha}}(1-t){sup {beta}}, where t is the reduced temperature. In addition, ac losses were calculated at the same fixed temperatures to compare theoretical solutions. There is a qualitative agreement between the experimental results and theory.

  9. Superconducting magnets and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J.E.C. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Francis Bitter National Magnet Lab.)

    1989-08-01

    Superconducting magnets are now being used in applications as diverse as medical imaging, fusion research, and power conditioning. The steady improvement in the understanding of instability and quenching has allowed increases in current density and compactness of winding. The reduction in winding size that has thus followed has allowed the construction of economic magnets for imaging, for acceleration, and for high-resolution spectrometers. Large magnets for fusion and energy applications have been made possible by composite conductors containing large fractions of copper or aluminum. The advent of high-temperature superconductors may hold the promise, eventually, of very-high-field magnets. Meanwhile low-temperature superconductors capable of generating fields up to 30 T have been developed.

  10. Superconducting Materials, Magnets and Electric Power Applications

    Science.gov (United States)

    Crabtree, George

    2011-03-01

    The surprising discovery of superconductivity a century ago launched a chain of convention-shattering innovations and discoveries in superconducting materials and applications that continues to this day. The range of large-scale applications grows with new materials discoveries - low temperature NbTi and Nb3 Sn for liquid helium cooled superconducting magnets, intermediate temperature MgB2 for inexpensive cryocooled applications including MRI magnets, and high temperature YBCO and BSSCO for high current applications cooled with inexpensive liquid nitrogen. Applications based on YBCO address critical emerging challenges for the electricity grid, including high capacity superconducting cables to distribute power in urban areas; transmission of renewable electricity over long distances from source to load; high capacity DC interconnections among the three US grids; fast, self-healing fault current limiters to increase reliability; low-weight, high capacity generators enabling off-shore wind turbines; and superconducting magnetic energy storage for smoothing the variability of renewable sources. In addition to these grid applications, coated conductors based on YBCO deposited on strong Hastelloy substrates enable a new generation of all superconducting high field magnets capable of producing fields above 30 T, approximately 50% higher than the existing all superconducting limit based on Nb3 Sn . The high fields, low power cost and the quiet electromagnetic and mechanical operation of such magnets could change the character of high field basic research on materials, enable a new generation of high-energy colliding beam experiments and extend the reach of high density superconducting magnetic energy storage.

  11. Influence of the heat-treatment conditions on various types of multifilamentary Nb-46.5%Ti superconducting wires

    Science.gov (United States)

    Shin, Ik Sang; Sim, Ki Hong; Hwang, Duck Young; Jang, Kyeong Ho; Na, Sin Hye; Park, Pyeong Yeol

    2016-08-01

    Unlike the NbTi superconducting wires used for high critical current density, NbTi wires for Magnetic resonance imaging (MRI) magnets have larger and fewer NbTi monofilaments and different cross sections, which show different superconducting properties. This study investigated the effects of varying the temperature, number of heat-treatment cycles, and total strain over a wide range for multifilamentary Nb-46.5%Ti wires on a mass production scale for use in MRI magnets. The heat-treatment conditions were optimized for an NbTi superconducting wire and the critical current density and the n-value were measured as functions of the final strain at temperatures of 4.2 K and 7 T. We noticed that the superconducting properties increased with increasing final strain of the multifilamentary NbTi wire. The microstructure and the effects of the size and the distribution of α-Ti precipitates on the individual heat-treatment steps were observed by using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). We, consequently, found the heat-treatment conditions that provided the highest superconducting performance for the two types of NbTi wires used in this study, and the results of the study are expected to very helpful in establishing not only the heat-treatment conditions but also important manufacturing parameters, such as the total strain, even as the design of NbTi wires for used in MRI magnets as changing with industrial demand.

  12. Contribution of ion beam analysis methods to the development of second generation high temperature superconducting wires

    Science.gov (United States)

    Usov, I. O.; Arendt, P. N.; Foltyn, S. R.; Stan, L.; DePaula, R. F.; Holesinger, T. G.

    2010-06-01

    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 intermediate layer providing a suitable lattice match to the superconducting Y 1Ba 2Cu 3O 7 (YBCO) compound. This report demonstrates how a wide range of ion beam analysis techniques (SIMS, RBS, channeling, PIXE, PIGE, NRA and ERD) was employed for analysis of each buffer layer and the YBCO film. These results assisted in understanding of a variety of physical processes occurring during the buffer layer fabrication and helped to optimize the buffer-layer architecture as a whole.

  13. Graphene wire medium: Homogenization and application

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Chigrin, Dmitry N.; Lavrinenko, Andrei

    2012-01-01

    In this contribution we analyze numerically the optical properties of the graphene wire medium, which unit cell consists of a stripe of graphene embedded into dielectric. We propose a simple method for retrieval of the isofrequency contour and effective permittivity tensor. As an example...... of the graphene wire medium application we demonstrate a reconfigurable hyperlens for the terahertz subwavelength imaging capable of resolving two sources with separation λ0/5 in the far-field....

  14. Superconductivity

    Science.gov (United States)

    1989-07-01

    SUPERCONDUCTIVITY HIGH-POWER APPLICATIONS Electric power generation/transmission Energy storage Acoustic projectors Weapon launchers Catapult Ship propulsion • • • Stabilized...temperature superconductive shields could be substantially enhanced by use of high-Tc materials. 27 28 NRAC SUPERCONDUCTIVITY SHIP PROPULSION APPLICATIONS...motor shown in the photograph. As a next step in the evolution of electric-drive ship propulsion technology, DTRC has proposed to scale up the design

  15. New concept for the development of Bi-2212 wires for high-field applications

    Science.gov (United States)

    Leveratto, A.; Braccini, V.; Contarino, D.; Ferdeghini, C.; Malagoli, A.

    2016-04-01

    The first step towards high critical currents in Bi-2212 wires was recognizing that the supercurrent is blocked over long lengths by filament-diameter bubbles grown during the melt stage, which cause expansion of the wire diameter and dedensification of the superconducting filaments. While a succesful approach to reducing the problem of voids related to bubbles involved the application of a high overpressure during the heat treatment, we fabricated Bi-2212 wires by applying a new concept of suitably alternating groove-rolling and drawing techniques with the aim of densifying the phase during the working procedure prior to the heat treatment. We here for the first time were able to reach, in wires reacted with closed ends—i.e. with gas trapped in the wire as it happens in long length wires—the very same values of critical current shown in short wires reacted with open ends. This is the irrefutable evidence that, only by acting on the deformation technique, we were able to raise the critical current by properly densifying the superconducting powder inside the filaments already before the melt stage. Whole-conductor current densities in our long-length simulation wires already reach 400 A mm-2 at 4.2 K and 5 T, which can be still easily increased through architecture optimization. The actual breakthrough is that the densification is optimized without further complex treatments through a technique which can be straightforwardly applied to long length wires.

  16. Superconductivity

    CERN Document Server

    Thomas, D B

    1974-01-01

    A short general review is presented of the progress made in applied superconductivity as a result of work performed in connection with the high-energy physics program in Europe. The phenomenon of superconductivity and properties of superconductors of Types I and II are outlined. The main body of the paper deals with the development of niobium-titanium superconducting magnets and of radio-frequency superconducting cavities and accelerating structures. Examples of applications in and for high-energy physics experiments are given, including the large superconducting magnet for the Big European Bubble Chamber, prototype synchrotron magnets for the Super Proton Synchrotron, superconducting d.c. beam line magnets, and superconducting RF cavities for use in various laboratories. (0 refs).

  17. Aluminium-oxide wires for superconducting high kinetic inductance circuits

    Science.gov (United States)

    Rotzinger, H.; Skacel, S. T.; Pfirrmann, M.; Voss, J. N.; Münzberg, J.; Probst, S.; Bushev, P.; Weides, M. P.; Ustinov, A. V.; Mooij, J. E.

    2017-02-01

    We investigate thin films of conducting aluminium-oxide, also known as granular aluminium, as a material for superconducting high quality, high kinetic inductance circuits. The films are deposited by an optimised reactive DC magnetron sputter process and characterised using microwave measurement techniques at milli-Kelvin temperatures. We show that, by precise control of the reactive sputter conditions, a high room temperature sheet resistance and therefore high kinetic inductance at low temperatures can be obtained. For a coplanar waveguide resonator with 1.5 kΩ sheet resistance and a kinetic inductance fraction close to unity, we measure a quality factor in the order of 700 000 at 20 mK. Furthermore, we observe a sheet resistance reduction by gentle heat treatment in air. This behaviour is exploited to study the kinetic inductance change using the microwave response of a coplanar wave guide resonator. We find the correlation between the kinetic inductance and the sheet resistance to be in good agreement with theoretical expectations.

  18. Microstructure and superconducting properties of nanocarbon-doped internal Mg diffusion-processed MgB2 wires fabricated using different boron powders

    Science.gov (United States)

    Xu, Da; Wang, Dongliang; Li, Chen; Yuan, Pusheng; Zhang, Xianping; Yao, Chao; Dong, Chiheng; Huang, He; Ma, Yanwei; Oguro, Hidetoshi; Awaji, Satoshi; Watanabe, Kazuo

    2016-04-01

    MgB2/Nb/Monel monofilament wires were fabricated using four different boron powders by an internal Mg diffusion (IMD) process. The microstructure, morphology and the critical current density (J c) of the used boron powders and the formative MgB2 layers were analyzed and compared. It was found that the purity and particle size of the boron powder influence the superconducting properties of MgB2 wires; further that the optimized heat-treatment condition also depends on the quality of the boron powder. The highest J c was obtained in the MgB2 layer made using amorphous boron (AB) powder, although a certain amount of voids existed in the superconducting layer. The IMD-processed MgB2 layer fabricated using high-purity boron (HB) powder had also a high J c compared with the powder-in-tube (PIT) process and a few unreacted boron particles remained in it. MgB2 wire fabricated using low-purity boron (LB) powder had a high cost-performance ratio compared with the others, which is expected to allow the fabrication of large-scale and low-cost superconducting wires for practical application. However, the enhancement of the J c was not found in the MgB2 layer manufactured using the ball-milled LB (MLB) powder as expected due to the increased percentage of impurity.

  19. Magnetization study of ITER-type internal-Sn Nb3Sn superconducting wire

    Institute of Scientific and Technical Information of China (English)

    Zhang Chao-Wu; Zhou Lian; Andre Sulpice; Jean-Louis Soubeyroux; Christophe Verwaerde; Gia Ky Hoang; Zhang Ping-Xiang; Lu Ya-Feng; Tang Xian-De

    2007-01-01

    Through magnetization measurement with a SQUID magnetometer the heat treatment optimization of an international thermonuclear experimental reactor (ITER)-type internal-Sn Nb3Sn superconducting wire has been investigated. The irreversibility temperature T*(H), which is mainly dependent on A15 phase composition, was obtained by a warming and cooling cycle at a fixed field. The hysteresis width △M(H) which reflects the flux pinning situation of the A15 phase is determined by the sweeping of magnetic field at a constant temperature. The results obtained from differently heat-treated samples show that the combination of T*(H) with △M(H) measurement is very effective for optimizing the heat reaction process. The heat treatment condition of the ITER-type wire is optimized at 675 ℃/128 h, which results in a composition closer to stoichiometric Nb3Sn and a state with best flux pinning.

  20. Applied superconductivity handbook on devices and applications

    CERN Document Server

    2015-01-01

    This wide-ranging presentation of applied superconductivity, from fundamentals and materials right up to the latest applications, is an essential reference for physicists and engineers in academic research as well as in the field. Readers looking for a systematic overview on superconducting materials will expand their knowledge and understanding of both low and high Tc superconductors, including organic and magnetic materials. Technology, preparation and characterization are covered for several geometries, but the main benefit of this work lies in its broad coverage of significant applications in power engineering or passive devices, such as filter and antenna or magnetic shields. The reader will also find information on superconducting magnets for diverse applications in mechanical engineering, particle physics, fusion research, medicine and biomagnetism, as well as materials processing. SQUIDS and their usage in medicine or geophysics are thoroughly covered as are applications in quantum metrology, and, las...

  1. Power applications for superconducting cables

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Hansen, Steen; Jørgensen, Preben

    2000-01-01

    High temperature superconducting (HTS) cables for use in electric ac power systems are under development around the world today. There are two main constructions under development: the room temperature dielectric design and the cryogenic dielectric design. However, theoretical studies have shown...

  2. Magnetic and superconducting nanowires

    DEFF Research Database (Denmark)

    Piraux, L.; Encinas, A.; Vila, L.

    2005-01-01

    magnetic and superconducting nanowires. Using different approaches entailing measurements on both single wires and arrays, numerous interesting physical properties have been identified in relation to the nanoscopic dimensions of these materials. Finally, various novel applications of the nanowires are also...

  3. Exploration of new superconductors and functional materials, and fabrication of superconducting tapes and wires of iron pnictides.

    Science.gov (United States)

    Hosono, Hideo; Tanabe, Keiichi; Takayama-Muromachi, Eiji; Kageyama, Hiroshi; Yamanaka, Shoji; Kumakura, Hiroaki; Nohara, Minoru; Hiramatsu, Hidenori; Fujitsu, Satoru

    2015-06-01

    This review shows the highlights of a 4-year-long research project supported by the Japanese Government to explore new superconducting materials and relevant functional materials. The project found several tens of new superconductors by examining ∼1000 materials, each of which was chosen by Japanese experts with a background in solid state chemistry. This review summarizes the major achievements of the project in newly found superconducting materials, and the fabrication wires and tapes of iron-based superconductors; it incorporates a list of ∼700 unsuccessful materials examined for superconductivity in the project. In addition, described are new functional materials and functionalities discovered during the project.

  4. Manufacture, electromagnetic properties and microstructure of an 18-filament jelly-roll Nb3Al superconducting wire with rapid heating and quenching heat-treatment

    Science.gov (United States)

    Pan, X. F.; Feng, Y.; Yan, G.; Cui, L. J.; Chen, C.; Zhang, Y.; Wu, Z. X.; Liu, X. H.; Zhang, P. X.; Bai, Z. M.; Zhao, Y.; Li, L. F.

    2016-01-01

    In this paper, we have reported the manufacture of a novel simple-structured jelly-roll Nb3Al precursor long wire, and its electromagnetic properties and microstructure with different rapid heating and quenching (RHQ) heat-treatments. By comparing three processing methods, it is found that the rolling and drawing (RD) method is more suitable to the fabrication of kilometer-length Nb3Al precursor wire without annealing. Using homemade RHQ equipment, we have successfully carried out RHQ heat-treatment of Nb3Al wire samples with various heating conditions. Based on magnetization and magnetoresistivity measurements, the onset superconducting transition temperature, T c and upper critical field, H c2 (0) of optimal Nb3Al wire reach 17.9 K-18.0 K and 29.7 T, respectively. Through microstructure and composition analysis, the Nb3Al superconductor in the optimal wire displays a typical ‘layer-to-layer’ structure, which comprises alternate crystalline Nb3Al and amorphous Nb layers, and the Nb3Al grains sizes are about 100 nm-300 nm. Furthermore, many small holes are dispersed in the Nb3Al superconductor due to the diffusion reaction from Al to Nb site. The work suggests the simple-structured Nb3Al precursor wire with RHQ heat-treatment is very promising for high-field application.

  5. Energy losses in mixed matrix superconducting wires under fast pulsed conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wollan, J.J.

    1976-08-17

    Energy losses have been measured on a set of mixed matrix (CuNi, Cu, NbTi) superconducting wires at B's up to 1.5 x 10/sup 7/ G/s. The losses have been measured as a function of wire diameter, twist pitch, maximum applied field, and B. Both static and dynamic losses were measured for a field applied perpendicularly to the wire axis. The dynamic losses were measured by slowly applying an external field to a sample and then causing the field to decay exponentially in roughly 1 ms to 10 ms. Under low B (9 kG) and B (10/sup 6/ G/s) conditions the hysteretic loss dominated. At high B (21 kG) and B (1.5 x 10/sup 7/ G/s) the matrix losses became dominant. The systematic variation of the losses with the mentioned parameters will be presented and will be compared to theoretical predictions.

  6. Fabrication and superconducting properties of internal Mg diffusion processed MgB2 wires using MgB4 precursors

    Science.gov (United States)

    Xu, Da; Wang, Dongliang; Yao, Chao; Zhang, Xianping; Ma, Yanwei; Oguro, Hidetoshi; Awaji, Satoshi; Watanabe, Kazuo

    2016-10-01

    Monofilament MgB2/Nb/Monel wires were fabricated using three different MgB4 precursors by an internal Mg diffusion (IMD) process. The wire geometry and heat-treatment conditions were optimized in order to improve the critical current density (J c) of the MgB2 wire. The influences of the quality of MgB4 powders, such as the particle size and MgO impurity, on the microstructure and superconducting properties of the wires were discussed. Although there were small amounts of voids, unreacted MgB4 particles and MgO impurity existed in the superconducting layers, and the transport layer J c of the wire with the MgB4 precursor reached 3.0 × 104 A cm-2 at 4.2 K and 10 T, which was comparable to that of IMD-processed wires fabricated using boron precursors. Both the non-barrier J c and engineering J c of MgB2 wire made using a MgB4 precursor were enhanced due to the improved grain connectivity and the enlarged fill factor.

  7. Performance of titanium oxide-polymer insulation in superconducting coils made of Bi-2212/Ag-alloy round wire

    Science.gov (United States)

    Chen, Peng; Trociewitz, Ulf P.; Dalban-Canassy, Matthieu; Jiang, Jianyi; Hellstrom, Eric E.; Larbalestier, David C.

    2013-07-01

    Conductor insulation is one of the key components needed to make Ag-alloy clad Bi2Sr2CaCu2O8+x (Bi-2212/Ag) superconducting round wire (RW) successful for high field magnet applications, as dielectric standoff and high winding current densities (Jw) directly depend on it. In this study, a TiO2-polymer insulation coating developed by nGimat LLC was applied to test samples and a high field test coil. The insulation was investigated by differential thermal analysis (DTA), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), dielectric property measurement, and transport critical current (Ic) property measurement. About 29% of the insulation by weight is polymer. When the Bi-2212/Ag wire is fully heat treated, this decomposes with slow heating to 400 ° C in pure O2. After the full reaction, we found that the TiO2 did not degrade the critical current properties, adhered well to the conductor, and provided a breakdown voltage of more than 100 V, which allowed the test coil to survive quenching in 31.2 T background field, while providing a 2.6 T field increment. For Bi-2212/Ag RW with a typical diameter of 1.0-1.5 mm, this ˜15 μm thick insulation allows a very high coil packing factor of ˜0.74, whereas earlier alumino-silicate braid insulation only allows packing factors of 0.38-0.48.

  8. Power applications for superconducting cables in Denmark

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Østergaard, Jacob; Olsen, S. Krüger

    1999-01-01

    In Denmark a growing concern for environmental protection has lead to wishes that the open country is kept free of overhead lines as far as possible. New lines under 100 kV and existing 60/50 kV lines should be established as underground cables. Superconducting cables represent an interesting...... alternative to conventional cables, as they are able to transmit two or more times the energy than a conventional cable. HTS cables with a room temperature dielectric design are especially interesting as a target for replacing overhead lines. Superconducting cables in the overall network are of interest...... in cases such as transmission of energy into cities and through areas of special interest. The planned large groups of windmills in Denmark generating up to 2000 MVA or more both on dry land and off-shore will be an obvious case for the application of superconducting AC or DC cables. These opportunities...

  9. Influence of filament diameter on superconducting properties of MgB2 multi-core wires

    Science.gov (United States)

    Reissner, M.; Bulla, L.; Husek, I.; Melišek, T.; Kováč, P.

    2013-06-01

    Magnetic behaviour of a series of MgB2 wires, in each case with 19 filaments of superconductor, surrounded by Ti as barrier and reinforced by stainless steel, prepared in the same way but mechanically deformed to different filament diameters ϕ between 58.5 and 17.7 µm, was investigated. Whereas no influence of ϕ on superconducting transition temperature is found, the width of the transition increases with ϕ. Critical current density, irreversibility line and mean effective activation energy U decrease systematically with decreasing ϕ. From a comparison of the field dependence of the pinning force and the temperature dependence of U, it is concluded, that pinning is dominated at low fields by grain boundary pinning and at higher fields by point defect pinning, with a rather broad distribution of pinning energies.

  10. Bifurcation Diagram and Pattern Formation of Phase Slip Centers in Superconducting Wires Driven with Electric Currents

    Science.gov (United States)

    Rubinstein, J.; Sternberg, P.; Ma, Q.

    2007-10-01

    We provide here new insights into the classical problem of a one-dimensional superconducting wire exposed to an applied electric current using the time-dependent Ginzburg-Landau model. The most striking feature of this system is the well-known appearance of oscillatory solutions exhibiting phase slip centers (PSC’s) where the order parameter vanishes. Retaining temperature and applied current as parameters, we present a simple yet definitive explanation of the mechanism within this nonlinear model that leads to the PSC phenomenon and we establish where in parameter space these oscillatory solutions can be found. One of the most interesting features of the analysis is the evident collision of real eigenvalues of the associated PT-symmetric linearization, leading as it does to the emergence of complex elements of the spectrum.

  11. Void formation in Nb3Sn-Cu superconducting wire produced by the external tin process

    Science.gov (United States)

    Verhoeven, J. D.; Efron, A.; Gibson, E. D.; Cheng, C. C.

    1986-03-01

    The tin (Sn) diffusion step for producing Nb3Sn-Cu superconducting wire by the external Sn process was modeled in experiments where either pure Sn or a Cu-Sn alloy was plated on sheets of either pure Cu or a Cu-Sn bronze. Each stage of the three-stage solid-state diffusion process was evaluated and it was found that rows of voids are produced in stage I of the process. These voids coarsen in stages II and III and in the worst case they are observed to coalesce and cause complete spalling away of the Sn-rich diffusion layers. Methods for minimizing void formation and possible causes of the void formation are discussed.

  12. Aerospace applications of high temperature superconductivity

    Science.gov (United States)

    Heinen, V. O.; Connolly, D. J.

    1991-01-01

    Space application of high temperature superconducting (HTS) materials may occur before most terrestrial applications because of the passive cooling possibilities in space and because of the economic feasibility of introducing an expensive new technology which has a significant system benefit in space. NASA Lewis Research Center has an ongoing program to develop space technology capitalizing on the potential benefit of HTS materials. The applications being pursued include space communications, power and propulsion systems, and magnetic bearings. In addition, NASA Lewis is pursuing materials research to improve the performance of HTS materials for space applications.

  13. Development of Bi-2212 round wires for high field magnet applications

    Science.gov (United States)

    Miao, H.; Huang, Y.; Meinesz, M.; Hong, S.; Parrell, J.

    2012-06-01

    Our latest progress on development of Bi-2212 round wire and insert coils is presented. We report on systematic investigations of the impact of wire drawing die angle and reduction per pass on the superconducting core density and Jc/JE performance. Several processes have been demonstrated to increase the Bi-2212 core density in green wire, improve filament homogeneity in heat treated wire, and significantly enhance wire performance. The process condition and final performance of several high performance insert coils are discussed.

  14. Design and fabrication of a 30 T superconducting solenoid using overpressure processed Bi2212 round wire

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, Gene [Muons, Inc., Batavia, IL (United States); Johnson, Rolland [Muons, Inc., Batavia, IL (United States)

    2016-02-18

    High field superconducting magnets are used in particle colliders, fusion energy devices, and spectrometers for medical imaging and advanced materials research. Magnets capable of generating fields of 20-30 T are needed by future accelerator facilities. A 20-30 T magnet will require the use of high-temperature superconductors (HTS) and therefore the challenges of high field HTS magnet development need to be addressed. Superconducting Bi2Sr2CaCu2Ox (Bi2212) conductors fabricated by the oxide-powder-in-tube (OPIT) technique have demonstrated the capability to carry large critical current density of 105 A/cm2 at 4.2 K and in magnetic fields up to 45 T. Available in round wire multi-filamentary form, Bi2212 may allow fabrication of 20-50 T superconducting magnets. Until recently the performance of Bi2212 has been limited by challenges in realizing high current densities (Jc ) in long lengths. This problem now is solved by the National High Magnetic Field Lab using an overpressure (OP) processing technique, which uses external pressure to process the conductor. OP processing also helps remove the ceramic leakage that results when Bi-2212 liquid leaks out from the sheath material and reacts with insulation, coil forms, and flanges. Significant advances have also been achieved in developing novel insulation materials (TiO2 coating) and Ag-Al sheath materials that have higher mechanical strengths than Ag-0.2wt.% Mg, developing heat treatment approaches to broadening the maximum process temperature window, and developing high-strength, mechanical reinforced Bi-2212 cables. In the Phase I work, we leveraged these new opportunities to prototype overpressure processed solenoids and test them in background fields of up to 14 T. Additionally a design of a fully superconducting 30 T solenoid was produced. This work in conjunction with the future path outlined in the Phase II proposal would

  15. Third NASA Workshop on Wiring for Space Applications

    Science.gov (United States)

    Hammoud, Ahmad (Compiler); Stavnes, Mark (Compiler)

    1995-01-01

    This workshop addressed key technology issues in the field of electrical power wiring for space applications, and transferred information and technology related to space wiring for use in government and commercial applications. Speakers from space agencies, U.S. Federal labs, industry, and academia presented program overviews and discussed topics on arc tracking phenomena, advancements in insulation materials and constructions, and new wiring system topologies.

  16. High-performance MgB2 superconducting wires for use under liquid-helium-free conditions fabricated using an internal Mg diffusion process

    Science.gov (United States)

    Ye, ShuJun; Song, Minghui; Matsumoto, Akiyoshi; Togano, Kazumasa; Takeguchi, Masaki; Ohmura, Takahito; Kumakura, Hiroaki

    2013-12-01

    MgB2 has a superconducting transition temperature (Tc) of 39 K, which is much higher than that for practical metallic superconductors. Thus, it is hoped that MgB2 can not only replace metallic superconductors, but can be used under liquid-helium-free conditions, for example, at temperatures of 10-20 K that can easily be achieved using cryocooling systems. However, to date, the reported critical current density (Jc) for MgB2 wires is not high enough for large-scale applications in liquid-helium-free conditions. In the present study, successful fabrication of high-performance MgB2 superconducting wires was carried out using an internal Mg diffusion (IMD) process, involving a p-dimethylbenzene (C8H10) pre-treatment of carbon-coated B powder with nanometer-sized particles. The resulting wires exhibited the highest ever Jc of 1.2 × 105 A cm-2 at 4.2 K and 10 T, and an engineering critical current density (Je) of about 1 × 104 A cm-2. Not only in 4.2 K, but also in 10 K, the Jc values for the wires fabricated in the present study are in fact higher than that for Nb-Ti wires at 4.2 K for the magnetic fields at which the measurements were carried out. At 20 K and 5 T, the Jc and Je were about 7.6 × 105 A cm-2 and 5.3 × 103 A cm-2, respectively, which are the highest values reported for MgB2 wires to date. The results of a detailed microstructural analysis suggested that the main reason for the superior electrical performance was the high density of the MgB2 layer rather than just the small grain size, and that the critical current could be further increased by suitable control of the microstructure. These high-performance IMD-processed MgB2 wires are thus promising superconductors for applications such as magnetic resonance imaging and maglev trains that can operate under liquid-helium-free conditions.

  17. Overview of Superconductivity and Challenges in Applications

    CERN Document Server

    Flükiger, Rene

    2012-01-01

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

  18. Proposal to negotiate an amendment to an existing contract for the supply of superconducting wire for the LHC corrector magnets

    CERN Document Server

    2005-01-01

    This document concerns the proposal to negotiate an amendment to an existing contract for the supply of superconducting wire for the LHC corrector magnets. For the reasons explained in this document, the Finance Committee is invited to approve an amendment to an existing contract with the firm ALSTOM (FR) for the supply of an additional 1 270 km of superconducting wire (Types 1 and 2) for an amount of 257 549 euros (402 679 Swiss francs), subject to revision for inflation, bringing the total to a maximum amount of 2 814 170 euros (4 399 955 Swiss francs), subject to revision for inflation. The amounts in Swiss francs have been calculated using the present rate of exchange.

  19. Penalty-Finite Element Analysis of the Eddy Current Loss in a Fully-Stabilized Multifilamentary Superconducting Wire

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The paper is mainly concerned with the penalty incurred in finiteelement analysis of the eddy-current loss problem in a fully established multi-filamentary superconducting wire. A finite element model with 4-node quadrilateral isoparametric elements is formulated for the present problem. Unlike the conventional vector potential scheme in use for electromagnetic field problem, the present work features a direct computational approach to eddy current loss. Simplicity and remarkable enhancement in computational accuracy can be obtained with the proposed method.

  20. Proposal for the award of two contracts, each for the supply of 60 km of superconducting multi-wire cable

    CERN Document Server

    2001-01-01

    This document concerns the award of two contracts, each for the supply of 60 km of superconducting multi-wire cable. Following a market survey carried out among sixteen firms in six Member States, Japan and the USA, a call for tenders (IT-2563/LHC/LHC) was sent on 6 December 2000 to four firms in four Member States. By the closing date, CERN had received three tenders from three firms in three Member States. The Finance Committee is invited to agree to the negotiation of contracts with: - ALSTOM (FR), the lowest bidder, for the supply of 60 km of superconducting multi-wire cable for a total amount of 751 531 euros (1 157 599 Swiss francs), subject to revision after 31 December 2001, with options for 9 km of superconducting multi-wire cable, for an additional amount of 114 267 euros (176 008 Swiss francs), subject to revision after 31 December 2001, bringing the total amount to 865 798 euros (1 333 607 Swiss francs), subject to revision after 31 December 2001. The rate of exchange which has been used is that s...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    2009-01-01

    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.

  2. Applications of superconductivity to packaging

    Energy Technology Data Exchange (ETDEWEB)

    Hilbert, C.; Koger, H.; Ghoshal, U.; Gibson, D.A.; Smith, L.

    1989-05-01

    The potential applications of high temperature superconductors to packaging - interconnect technology - are reviewed. The authors caution against naive assumptions such as that it is obvious that superconductors will make computers run faster. On the other hand, they present examples in which the use of superconductors can significantly improve digital systems. These examples, however, involve much more than the simple substitution of superconductors for copper. They argue that imaginative uses of superconductors will eventually have a major impact on digital systems.

  3. Recent developments in superconducting materials including ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Tachikawa, Kyoji

    1987-06-01

    This report describes the history of superconduction starting in 1911, when the superconducting phenomenon was first observed in murcury, until the recent discovery of superconducting materials with high critical temperatures. After outlining the BCS theory, basic characteristics are discussed including the critical temperature, magnetic field and current density to be reached for realizing the superconducting state. Various techniques for practical superconducting materials are discussed, including methods for producing extra fine multiconductor wires from such superconducting alloys as Nb-Ti, intermetallic Nb/sub 3/Sn compound and V/sub 3/Ga, as well as methods for producing wires of Nb/sub 3/Al, Nb/sub 3/(Al, Ge) and Nb/sub 3/Ge such as continuous melt quenching, electron beam irradiation, laser beam irradiation and chemical evaporation. Characteristics of superconducting ceramics are described, along with their applications including superconducting magnets and superconducting elements. (15 figs, 1 tab, 19 refs)

  4. Variations in the characteristics of the superconducting wire used for the ISR superconducting high-luminosity insertion

    CERN Document Server

    Billan, J; Wolf, R

    1981-01-01

    A total of 30000 meters of NbTi solid multifilamentary superconductor, I/sub c/ approximately 2500 A at 6 T, was tested. For each stretch of wire received, measurements were made to check if the wire met the specifications. The specification and the measuring set-up are described. Systematic measurements of the critical currents, Cu:SC ratio, Ti content and wire size are discussed. A strong variation in the critical current could be correlated to a strong variation in the Ti content. (4 refs).

  5. Electro-mechanical characterization of MgB2 wires for the Superconducting Link Project at CERN

    Science.gov (United States)

    Konstantopoulou, K.; Ballarino, A.; Gharib, A.; Stimac, A.; Garcia Gonzalez, M.; Perez Fontenla, A. T.; Sugano, M.

    2016-08-01

    In previous years, the R & D program between CERN and Columbus Superconductors SpA led to the development of several configurations of MgB2 wires. The aim was to achieve excellent superconducting properties in high-current MgB2 cables for the HL-LHC upgrade. In addition to good electrical performance, the superconductor shall have good mechanical strength in view of the stresses during operation (Lorenz forces and thermal contraction) and handling (tension and bending) during cabling and installation at room temperature. Thus, the study of the mechanical properties of MgB2 wires is crucial for the cable design and its functional use. In the present work we report on the electro-mechanical characterization of ex situ processed composite MgB2 wires. Tensile tests (critical current versus strain) were carried out at 4.2 K and in a 3 T external field by means of a purpose-built bespoke device to determine the irreversible strain limit of the wire. The minimum bending radius of the wire was calculated taking into account the dependence of the critical current with the strain and it was then used to obtain the minimum twist pitch of MgB2 wires in the cable. Strands extracted from cables having different configurations were tested to quantify the critical current degradation. The Young’s modulus of the composite wire was measured at room temperature. Finally, all measured mechanical parameters will be used to optimize an 18-strand MgB2 cable configuration.

  6. Proposal for the change of contractor for the supply of superconducting wires for the LHC corrector magnets

    CERN Document Server

    2001-01-01

    This document concerns the change of contractor for the supply of superconducting wires of four different types (1 to 4) for the LHC corrector magnets. For the reasons set out in this document, the Finance Committee is invited to agree to the negotiation of a contract with ALSTOM (FR), for the supply of superconducting wire for a total amount of 1 963 793 euros (3 140 059 Swiss francs), not subject to revision until 31 December 2001, with options for up to 20% additional wire, for an additional amount of 392 759 euros (628 012 Swiss francs), not subject to revision until 31 December 2001, bringing the total amount to 2 356 552 euros (3 768 071 Swiss francs), not subject to revision until 31 December 2001. The rate of exchange which has been used is that stipulated in the tender. The firm has indicated the following distribution by country of the contract value covered by this adjudication proposal: FR - 67%, US - 27%, DE - 4% and BE - 2%.

  7. Second NASA Workshop on Wiring for Space Applications

    Science.gov (United States)

    1994-01-01

    This document contains the proceedings of the Second NASA Workshop on Wiring for Space Applications held at NASA LeRC in Cleveland, OH, 6-7 Oct. 1993. The workshop was sponsored by NASA Headquarters Code QW Office of Safety and Mission Quality, Technical Standards Division and hosted by NASA LeRC, Power Technology Division, Electrical Components and Systems Branch. The workshop addressed key technology issues in the field of electrical power wiring for space applications. Speakers from government, industry, and academia presented and discussed topics on arc tracking phenomena, wiring system design, insulation constructions, and system protection. Presentation materials provided by the various speakers are included in this document.

  8. Experimental hysteretic loss for a series of superconducting filamentary NbTi wires and a field dependent critical state model. Final technical report 2 Oct 1972--31 Dec 1974

    Energy Technology Data Exchange (ETDEWEB)

    Ohmer, M.C.; Wollan, J.J.; Lawson, L.O.

    1975-07-01

    This report summarizes the Air Force superconducting wire applications, the goals of future superconducting materials development, the state of the art theories of ac loss in superconductors, and the results of hysteretic loss measurements on a series of niobium--titanium multifilamentary wires. Expressions were developed for magnetization and hysteretic loss for half cycle and full cycle for rod geometries for a critical state model with critical current inversely proportional to field. Bulk effects with surface like character are discussed along with surface shielding fields and the demagnetizing factor. The loss expressions of various models are compared to experimental loss. Universal loss curves constructed from experimental loss curves by appropriate normalization are obtained and used to predict loss accurately. (GRA)

  9. Superconductivity

    CERN Document Server

    Poole, Charles P; Farach, Horacio A

    1995-01-01

    Superconductivity covers the nature of the phenomenon of superconductivity. The book discusses the fundamental principles of superconductivity; the essential features of the superconducting state-the phenomena of zero resistance and perfect diamagnetism; and the properties of the various classes of superconductors, including the organics, the buckministerfullerenes, and the precursors to the cuprates. The text also describes superconductivity from the viewpoint of thermodynamics and provides expressions for the free energy; the Ginzburg-Landau and BCS theories; and the structures of the high

  10. Effect of the wire width on the intrinsic detection efficiency of superconducting-nanowire single-photon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lusche, R., E-mail: robert.lusche@dlr.de; Semenov, A. [Institute of Planetary Research, German Aerospace Center (DLR), Rutherfordstr. 2, 12489 Berlin (Germany); Ilin, K.; Siegel, M. [Institute of Micro- und Nano-electronic Systems (IMS), KIT, Hertzstrasse 16, 76187 Karlsruhe (Germany); Korneeva, Y.; Trifonov, A. [Department of Physics, Moscow State Pedagogical University, 1 Malaya Pirogovskaya, 119991 Moscow (Russian Federation); Korneev, A. [Department of Physics, Moscow State Pedagogical University, 1 Malaya Pirogovskaya, 119991 Moscow (Russian Federation); National Research University Higher School of Economics, 20 Myasnitskaya Ulitsa, Moscow 101000 (Russian Federation); Moscow Institute of Physics and Technology (State University), 9 Institutskiy pereulok, Dolgoprudny, Moscow region 141700 (Russian Federation); Goltsman, G. [Department of Physics, Moscow State Pedagogical University, 1 Malaya Pirogovskaya, 119991 Moscow (Russian Federation); National Research University Higher School of Economics, 20 Myasnitskaya Ulitsa, Moscow 101000 (Russian Federation); Vodolazov, D. [Institute for Physics of Microstructures, Russian Academy of Sciences, 603950 Nizhny Novgorod, GSP-105 (Russian Federation); Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, 603950 Nizhny Novgorod (Russian Federation); Hübers, H.-W. [Institute of Planetary Research, German Aerospace Center (DLR), Rutherfordstr. 2, 12489 Berlin (Germany); Institut für Optik und Atomare Physik, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin (Germany)

    2014-07-28

    A thorough spectral study of the intrinsic single-photon detection efficiency in superconducting TaN and NbN nanowires with different widths has been performed. The experiment shows that the cut-off of the intrinsic detection efficiency at near-infrared wavelengths is most likely controlled by the local suppression of the barrier for vortex nucleation around the absorption site. Beyond the cut-off quasi-particle diffusion in combination with spontaneous, thermally activated vortex crossing explains the detection process. For both materials, the reciprocal cut-off wavelength scales linearly with the wire width where the scaling factor agrees with the hot-spot detection model.

  11. Cu-Nb reinforced (Nb, Ti){sub 3}Sn superconducting wire; Cu-Nb hokyo anteika (Nb, Ti){sub 3}Sn chodendo sen

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, H.; Endo, S.; Kimura, A.; Wada, K.; Meguro, S. [The Furukawa Electric Co., Ltd., Tokyo (Japan); Watanabe, K.; Awaji, S. [Tohoku Univ., Sendai (Japan)

    2000-05-29

    The development of Nb{sub 3}Sn super-conducting wire material by combining in-Situ Cu-Nb alloy as a reinforced stabilization material in the wire inside has been carried out until now. Since the reinforced stabilization wire materials are used for cryogenic magnet of large diameter refrigerating machine, manufacture of long wire is vital. In this report, the results of investigating characteristics of Cu-Nb reinforced stabilization wire materials produced in different manufacturing scale are reported. The Cu-20wt%-Nb alloy is adopted as the reinforced stabilization material of the bronze process Nb{sub 3}Sn super-conducting wire. The produced wire is heat-treated at 650 degrees C and 864ks for 240 hrs and its characteristics are investigated. The non-copper part Jc of the reinforced stabilization wire material is 551A/mm {sup 2} at 12T, 184A/mm{sup 2} at 16T, and 76A/mm{sup 2} at 18T, and rates to the non-copper part Jc of the comparison wire materials in the same magnetic field are 0.87, 0.75 and 0.61 respectively. (NEDO)

  12. Development of (Nb,Ta3Sn multifilamentary superconductor wire for high current applications

    Directory of Open Access Journals (Sweden)

    Rodrigues Jr. Durval

    2000-01-01

    Full Text Available The optimization of the energy generated by a MagnetoHydroDynamic (MHD channel using a superconducting magnet demands the optimization of the magnetic field of the system and of the critical points on the magnet winding. This work must include the development of a high performance superconductor wire suitable for this system. Aiming to the construction of improved performance MHD channel, it was developed a low cost superconductor wire, with the required characteristics. The wire was made using a technology compatible with the assembling steps and heat treatment conditions of the MHD superconducting magnets fabrication. It was used the internal Sn method in Nb-7.5wt%Ta tube to fabricate a 271-filament wire with a diameter of 0.81 mm and a Cu/nonCu ratio of 2.3. The wire was heat treated at 200 °C to diffuse the Sn into the Cu shell, producing bronze, followed by the final reaction at temperatures ranging from 670 °C to 730 °C during 25 to 150 h, to produce (Nb,Ta3Sn. The superconducting wire characterization was made measuring the critical current Ic versus the applied magnetic field in the range of 5 to 20 T, the critical temperature Tc and the residual resistivity ratio (RRR. The wire transported critical currents above those available in commercial superconducting wires. These values of Ic are higher than the expected values for the optimization of the MHD channel.

  13. Effects of drawing and high-pressure sintering on the superconducting properties of (Ba,K)Fe2As2 powder-in-tube wires

    Science.gov (United States)

    Pyon, Sunseng; Yamasaki, Yuji; Kajitani, Hideki; Koizumi, Norikiyo; Tsuchiya, Yuji; Awaji, Satoshi; Watanabe, Kazuo; Tamegai, Tsuyoshi

    2015-12-01

    The evolution of the superconducting properties of round wires of (Ba,K)Fe2As2 fabricated by the powder-in-tube (PIT) method is systematically studied. After establishing the method to obtain the largest transport critical current density (J c) in round wires using the hot isostatic press technique, we investigated how the transition temperature (T c), J c, and microstructures change at each step of the wire fabrication. Unexpectedly, we find that superconducting properties of the wire core are significantly damaged by the drawing process. Systematic measurements of J c and T c of the core superconductor after each drawing and sintering process clarified the evolution of degradation by the drawing process and recovery by heat treatment.

  14. Superconducting chip receivers for imaging application

    NARCIS (Netherlands)

    Shitov, SV; Koshelets, VP; Ermakov, AB; Filippenko, LV; Baryshev, AM; Luinge, W; Gao, [No Value

    1999-01-01

    Experimental details of a unique superconducting imaging array receiver are discussed. Each pixel contains an internally pumped receiver chip mounted on the back of the elliptical microwave lens. Each chip comprises a quasi-optical SIS mixer integrated with a superconducting flux-flow oscillator (FF

  15. Differences in the effects of turns and constrictions on the resistive response in current-biased superconducting wire after single photon absorption

    OpenAIRE

    Zotova, A. N.; Vodolazov, D. Y.

    2013-01-01

    We study how turns and constrictions affect the resistive response of the superconducting wire after instant in time and local in space heating, which models the absorption of the single photon by the wire. We find that the presence of constriction favors detection of photons of various energies but the presence of turn increases only ability to detect relatively "low" energy photons. The main reason is that in case of constriction the current density is increased over whole length and width ...

  16. The Application of High Temperature Superconducting Materials to Power Switches

    CERN Document Server

    March, S A; Ballarino, A

    2009-01-01

    Superconducting switches may find application in superconducting magnet systems that require energy extraction. Such superconducting switches could be bypass-switches that are operated in conjunction with a parallel resistor or dump-switches where all of the energy is dissipated in the switch itself. Bypass-switches are more suited to higher energy circuits as a portion of the energy can be dissipated in the external dump resistor. Dump- switches require less material and triggering energy as a lower switch resistance is needed to achieve the required total dump resistance. Both superconducting bypass-switches and superconducting dump-switches can be ther- mally activated. Switching times that are comparable to those obtained with mechanical bypass-switch systems can be achieved using a co-wound heater that is powered by a ca- pacitor discharge. Switches that have fast thermal diffusion times through the insulation can be modelled as a lumped system whereas those with slow thermal diffusion times were modelle...

  17. Computation of Superconducting Generators for Wind Turbine Applications

    DEFF Research Database (Denmark)

    Rodriguez Zermeno, Victor Manuel

    , to the actual generators in the KW (MW) class with an expected cross section in the order of decimeters (meters). This thesis work presents cumulative results intended to create a bottom-up model of a synchronous generator with superconducting rotor windings. In a first approach, multiscale meshes with large...... relationship to model stacks of superconducting tapes. This method provided an additional speedup of about two orders of magnitude when calculating AC losses in superconducting stacks. The anisotropic bulk was latter used to model a generator with superconducting rotor windings. Transient response......The idea of introducing a superconducting generator for offshore wind turbine applications has received increasing support. It has been proposed as a way to meet energy market requirements and policies demanding clean energy sources in the near future. However, design considerations have to take...

  18. First NASA Workshop on Wiring for Space Applications

    Science.gov (United States)

    Hammond, Ahmad (Compiler); Stavnes, Mark W. (Compiler)

    1994-01-01

    This document contains the proceedings of the First NASA Workshop on Wiring for Space Applications held at NASA Lewis Research Center in Cleveland, OH, July 23-24, 1991. The workshop was sponsored by NASA Headquarters Code QE Office of Safety and Mission Quality, Technical Standards Division and hosted by the NASA Lewis Research Center, Power Technology Division, Electrical Components and Systems Branch. The workshop addressed key technology issues in the field of electrical power wiring for space applications. Speakers from government, industry and academia presented and discussed topics on arc tracking phenomena, wiring applications and requirements, and new candidate insulation materials and constructions. Presentation materials provided by the various speakers are included in this document.

  19. Porous Dielectrics in Microelectronic Wiring Applications

    Directory of Open Access Journals (Sweden)

    Vincent McGahay

    2010-01-01

    Full Text Available Porous insulators are utilized in the wiring structure of microelectronic devices as a means of reducing, through low dielectric permittivity, power consumption and signal delay in integrated circuits. They are typically based on low density modifications of amorphous SiO2 known as SiCOH or carbon-doped oxides, in which free volume is created through the removal of labile organic phases. Porous dielectrics pose a number of technological challenges related to chemical and mechanical stability, particularly in regard to semiconductor processing methods. This review discusses porous dielectric film preparation techniques, key issues encountered, and mitigation strategies.

  20. Applications of superconducting bolometers in security imaging

    Science.gov (United States)

    Luukanen, A.; Leivo, M. M.; Rautiainen, A.; Grönholm, M.; Toivanen, H.; Grönberg, L.; Helistö, P.; Mäyrä, A.; Aikio, M.; Grossman, E. N.

    2012-12-01

    Millimeter-wave (MMW) imaging systems are currently undergoing deployment World-wide for airport security screening applications. Security screening through MMW imaging is facilitated by the relatively good transmission of these wavelengths through common clothing materials. Given the long wavelength of operation (frequencies between 20 GHz to ~ 100 GHz, corresponding to wavelengths between 1.5 cm and 3 mm), existing systems are suited for close-range imaging only due to substantial diffraction effects associated with practical aperture diameters. The present and arising security challenges call for systems that are capable of imaging concealed threat items at stand-off ranges beyond 5 meters at near video frame rates, requiring substantial increase in operating frequency in order to achieve useful spatial resolution. The construction of such imaging systems operating at several hundred GHz has been hindered by the lack of submm-wave low-noise amplifiers. In this paper we summarize our efforts in developing a submm-wave video camera which utilizes cryogenic antenna-coupled microbolometers as detectors. Whilst superconducting detectors impose the use of a cryogenic system, we argue that the resulting back-end complexity increase is a favorable trade-off compared to complex and expensive room temperature submm-wave LNAs both in performance and system cost.

  1. Superconducting quantum circuits theory and application

    Science.gov (United States)

    Deng, Xiuhao

    Superconducting quantum circuit models are widely used to understand superconducting devices. This thesis consists of four studies wherein the superconducting quantum circuit is used to illustrate challenges related to quantum information encoding and processing, quantum simulation, quantum signal detection and amplification. The existence of scalar Aharanov-Bohm phase has been a controversial topic for decades. Scalar AB phase, defined as time integral of electric potential, gives rises to an extra phase factor in wavefunction. We proposed a superconducting quantum Faraday cage to detect temporal interference effect as a consequence of scalar AB phase. Using the superconducting quantum circuit model, the physical system is solved and resulting AB effect is predicted. Further discussion in this chapter shows that treating the experimental apparatus quantum mechanically, spatial scalar AB effect, proposed by Aharanov-Bohm, can't be observed. Either a decoherent interference apparatus is used to observe spatial scalar AB effect, or a quantum Faraday cage is used to observe temporal scalar AB effect. The second study involves protecting a quantum system from losing coherence, which is crucial to any practical quantum computation scheme. We present a theory to encode any qubit, especially superconducting qubits, into a universal quantum degeneracy point (UQDP) where low frequency noise is suppressed significantly. Numerical simulations for superconducting charge qubit using experimental parameters show that its coherence time is prolong by two orders of magnitude using our universal degeneracy point approach. With this improvement, a set of universal quantum gates can be performed at high fidelity without losing too much quantum coherence. Starting in 2004, the use of circuit QED has enabled the manipulation of superconducting qubits with photons. We applied quantum optical approach to model coupled resonators and obtained a four-wave mixing toolbox to operate photons

  2. Analysis of interdiffusion between SmFeAsO0.92F0.08 and metals for ex situ fabrication of superconducting wire

    Science.gov (United States)

    Fujioka, M.; Matoba, M.; Ozaki, T.; Takano, Y.; Kumakura, H.; Kamihara, Y.

    2011-07-01

    To find good sheath materials that react minimally with the superconducting core of iron-based superconducting wires, we investigated the reaction between polycrystalline SmFeAsO0.92F0.08 and the following seven metals: Cu, Fe, Ni, Ta, Nb, Cr and Ti. Each of the seven metals was prepared as a sheath-material candidate. The interfacial microstructures of SmFeAsO0.92F0.08 and these metal-sheath samples were analysed by an electron probe microanalyzer after annealing at 1000 °C for 20 h. Amongst the seven metal-sheath samples, we found that Cu was the best, because it reacted only very weakly with polycrystalline SmFeAsO0.92F0.08. Moreover, Cu is essential for superconducting wires as a stabilizing material. Metal sheaths made of Fe and Ni do not give rise to reaction layers, but large interdiffusion between these metals and polycrystalline SmFeAsO0.92F0.08 occurs. In contrast, metal sheaths made of Ta, Nb, Cr and Ti do form reaction layers. Their reaction layers apparently prevent electric current from flowing from the sheath material to the superconducting core. In general, through this research, Cu will be expected to be suitable not only as a stabilizing material but also as a sheath material for superconducting Sm-1111 wire fabricated by the ex situ PIT method.

  3. Microstructural and crystallographic imperfections of MgB2 superconducting wire and their correlation with the critical current density

    Directory of Open Access Journals (Sweden)

    Mohammed Shahabuddin

    2014-01-01

    Full Text Available A comprehensive study of the effects of structural imperfections in MgB2 superconducting wire has been conducted. As the sintering temperature becomes lower, the structural imperfections of the MgB2 material are increased, as reflected by detailed X-ray refinement and the normal state resistivity. The crystalline imperfections, caused by lattice disorder, directly affect the impurity scattering between the π and σ bands of MgB2, resulting in a larger upper critical field. In addition, low sintering temperature keeps the grain size small, which leads to a strong enhancement of pinning, and thereby, enhanced critical current density. Owing to both the impurity scattering and the grain boundary pinning, the critical current density, irreversibility field, and upper critical field are enhanced. Residual voids or porosities obviously remain in the MgB2, however, even at low sintering temperature, and thus block current transport paths.

  4. Qualitative modifications and new dynamic phases in the phase diagram of one-dimensional superconducting wires driven with electric currents

    Science.gov (United States)

    Kallush, Shimshon; Berger, Jorge

    2014-06-01

    After an initial transient period, the conduction regime in a one-dimensional superconducting wire that carries a fixed current is either normal, periodic, or stationary. The phase diagram for these possibilities was studied in Phys. Rev. Lett. 99, 167003 (2007), 10.1103/PhysRevLett.99.167003 for particular values of the length and the material parameters. We have extended this study to arbitrary length and to a range of material parameters that includes realistic values. Variation of the length leads to scaling laws for the phase diagram. Variation of the material parameters leads to new qualitative features and new phases, including a parameter region in which all three regimes are possible.

  5. Superconducting phase domains for memory applications

    NARCIS (Netherlands)

    Bakurskiy, S.V.; Klenov, N.V.; Soloviev, I.I.; Kupriyanov, M..Y.; Golubov, A.

    2016-01-01

    In this work, we study theoretically the properties of S-F/N-sIS type Josephson junctions in the frame of the quasiclassical Usadel formalism. The structure consists of two superconducting electrodes (S), a tunnel barrier (I), a combined normal metal/ferromagnet (N/F) interlayer, and a thin supercon

  6. Characterization of superconducting wires and cables by X-ray micro-tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tiseanu, Ion, E-mail: tiseanu@infim.ro [National Institute for Laser, Plasma and Radiation Physics, Atomistilor Street 409, Bucharest, Magurele (Romania); Zani, Louis [JT60-SA EU Home Team, Fusion for Energy, Boltzmannstrasse 2, 85748 Garching (Germany); Craciunescu, Teddy [National Institute for Laser, Plasma and Radiation Physics, Atomistilor Street 409, Bucharest, Magurele (Romania); Cotorobai, Florin [National Institute for Laser, Plasma and Radiation Physics, Atomistilor Street 409, Bucharest, Magurele (Romania); National Institute for Material Physics, Atomistilor Street, 105bis, Bucharest, Magurele (Romania); Dobrea, Cosmin; Sima, Adrian [National Institute for Laser, Plasma and Radiation Physics, Atomistilor Street 409, Bucharest, Magurele (Romania)

    2013-10-15

    Highlights: • A methodology in support of quality controls monitoring of Cable-in-Conduit-Conductor (CICC) to be used in tokamak magnet systems was developed. • High resolution (≈40 μm) X-ray tomography images of CICC section up to 300 mm long have been obtained. • All constitutive elements of CICC (316SS jacket, NbTi and Cu strands and external wrapper foil) can be noninvasively inspected. • Derivation of quantities like void fraction and void homogeneity at the local and global level, automatic identification of individual NbTi and Cu strands. • Derivation of geometric parameters like: trajectory, pitch angle and their space distribution. -- Abstract: Due to their mechanical strength and ability to withstand the large electromagnetic force applied to the superconductors in large magnets during excitation, the Cable-in-Conduit-Conductor (CICC) type superconductors will be employed in the next stage of fusion magnets. Here, we discuss the recent results on the application of a non-invasive method for the characterization of CCIC by X-ray micro-tomography (μXCT). The experiments have been carried out on a high resolution X-ray tomograph in INFLPR ( (http://tomography.inflpr.ro)). An open type nanofocus X-ray source with maximum high voltage of 225 kVp at 15–30 W maximum power and multiple targets of W on different windows materials (Be, Al, Cu or diamond) is the main component. X-rays are detected by means of amorphous silicon flat panel sensor in the cone-beam configuration and high-energy efficient line sensor based on individual scintillators in the fan-beam scanning configuration. The quality of tomographic images (≈40 μm space resolution) allowed the majority of strands of analyzed CICC samples to be fully reconstructed along the investigated segment (up to 300 mm long). Our method provides: (i) local and global void fractions (over a 300 mm length of the sample), (ii) void homogeneity factor as the ratio between void space surface and

  7. Peak effect and superconducting properties of SmFeAsO{sub 0.8}F{sub 0.2} wires

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y L; Cui, Y J; Yang, Y; Zhang, Y; Wang, L; Zhao, Y [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, and Superconductivity R and D Center (SRDC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C H; Sorrell, C [School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)], E-mail: yzhao@swjtu.edu.cn

    2008-11-15

    Ta-sheathed SmFeAsO{sub 0.8}F{sub 0.2} superconducting wires with T{sub c} = 52.5 K have been fabricated using the powder-in-tube (PIT) method and the superconducting properties of the wires have been investigated. The wires exhibit a very large intragrain critical current density at a temperature below 30 K. A peak effect with maximal J{sub c} = 0.6 MA cm{sup -2} at 10 K under 6 T field was observed. The peak field H{sub pear} is strongly temperature-dependent. A severe weak-link effect depresses the development of global supercurrent owing to a very short coherence length. The wires also show a power law temperature dependence for the irreversibility line with H{sub irr}{approx_equal}(1-T/T{sub c}){sup 1.5}. The H-T phase diagram was found to be similar to that of other superconducting cuprates.

  8. Superconducting spoke cavities for high-velocity applications

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-01

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

  9. Superconductivity

    CERN Document Server

    Ketterson, John B

    2008-01-01

    Conceived as the definitive reference in a classic and important field of modern physics, this extensive and comprehensive handbook systematically reviews the basic physics, theory and recent advances in the field of superconductivity. Leading researchers, including Nobel laureates, describe the state-of-the-art in conventional and unconventional superconductors at a particularly opportune time, as new experimental techniques and field-theoretical methods have emerged. In addition to full-coverage of novel materials and underlying mechanisms, the handbook reflects continued intense research into electron-phone based superconductivity. Considerable attention is devoted to high-Tc superconductivity, novel superconductivity, including triplet pairing in the ruthenates, novel superconductors, such as heavy-Fermion metals and organic materials, and also granular superconductors. What’s more, several contributions address superconductors with impurities and nanostructured superconductors. Important new results on...

  10. Applied superconductivity

    CERN Document Server

    Newhouse, Vernon L

    1975-01-01

    Applied Superconductivity, Volume II, is part of a two-volume series on applied superconductivity. The first volume dealt with electronic applications and radiation detection, and contains a chapter on liquid helium refrigeration. The present volume discusses magnets, electromechanical applications, accelerators, and microwave and rf devices. The book opens with a chapter on high-field superconducting magnets, covering applications and magnet design. Subsequent chapters discuss superconductive machinery such as superconductive bearings and motors; rf superconducting devices; and future prospec

  11. Superconducting properties of granular SmFeAsO{sub 1-x}F{sub x} wires with T{sub c} = 52 K prepared by the powder-in-tube method

    Energy Technology Data Exchange (ETDEWEB)

    Gao Zhaoshun; Wang Lei; Qi Yanpeng; Wang Dongliang; Zhang Xianping; Ma Yanwei [Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, PO Box 2703, Beijing 100190 (China); Yang Huan; Wen Haihu [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)], E-mail: ywma@mail.iee.ac.cn

    2008-11-01

    We report the fabrication of Ta-sheathed superconducting SmFeAsO{sub 1-x}F{sub x} wires by the powder-in-tube method for the first time. The transition temperature of the SmFeAsO{sub 0.65}F{sub 0.35} wires was confirmed to be as high as 52 K. High critical fields H{sub c2}(0){>=}120 T as well as current density J{sub c} of 3900 A cm{sup -2} at 5 K were also demonstrated. It should be noted that the J{sub c} exhibits a very weak field dependence behavior, indicating a very encouraging prospect for application of the new superconductors. (rapid communication)

  12. High field superconducting magnets

    Science.gov (United States)

    Hait, Thomas P. (Inventor); Shirron, Peter J. (Inventor)

    2011-01-01

    A superconducting magnet includes an insulating layer disposed about the surface of a mandrel; a superconducting wire wound in adjacent turns about the mandrel to form the superconducting magnet, wherein the superconducting wire is in thermal communication with the mandrel, and the superconducting magnet has a field-to-current ratio equal to or greater than 1.1 Tesla per Ampere; a thermally conductive potting material configured to fill interstices between the adjacent turns, wherein the thermally conductive potting material and the superconducting wire provide a path for dissipation of heat; and a voltage limiting device disposed across each end of the superconducting wire, wherein the voltage limiting device is configured to prevent a voltage excursion across the superconducting wire during quench of the superconducting magnet.

  13. Matrix field theory: Applications to superconductivity

    Science.gov (United States)

    Zhou, Lubo

    In this thesis a systematic, functional matrix field theory is developed to describe both clean and disordered s-wave and d-wave superconductors and the quantum phase transitions associated with them. The thesis can be divided into three parts. The first part includes chapters 1 to 3. In chapter one a general physical introduction is given. In chapters two and three the theory is developed and used to compute the equation of state as well as the number-density susceptibility, spin-density susceptibility, the sound attenuation coefficient, and the electrical conductivity in both clean and disordered s-wave superconductors. The second part includes chapter four. In this chapter we use the theory to describe the disorder-induced metal - superconductor quantum phase transition. The key physical idea here is that in addition to the superconducting order-parameter fluctuations, there are also additional soft fermionic fluctuations that are important at the transition. We develop a local field theory for the coupled fields describing superconducting and soft fermionic fluctuations. Using simple renormalization group and scaling ideas, we exactly determine the critical behavior at this quantum phase transition. Our theory justifies previous approaches. The third part includes chapter five. In this chapter we study the analogous quantum phase transition in disordered d-wave superconductors. This theory should be related to high Tc superconductors. Surprisingly, we show that in both the underdoped and overdoped regions, the coupling of superconducting fluctuations to the soft disordered fermionic fluctuations is much weaker than that in the s-wave case. The net result is that the disordered quantum phase transition in this case is a strong coupling, or described by an infinite disordered fixed point, transition and cannot be described by the perturbative RG description that works so well in the s-wave case. The transition appears to be related to the one that occurs in

  14. Superconducting Properties and Microstructure in MgB2 Bulks, Wires and Tapes

    Institute of Scientific and Technical Information of China (English)

    冯勇; 阎果; 赵勇; 吴晓京; 周廉; 张平祥

    2003-01-01

    We prepared a series of MgB2 bulk samples under different temperatures, holding time and increasing rates in temperature by the solid state reaction. The thermodynamic behavior and phase formation in the Mg-B system were studied by using DTA,XRD and SEM. The results indicate that the formation of the MgB2 phase is very fast and the high increasing rate in temperature is necessary to obtain high quality MgB2. In addition, the effects of the Zr-doping in Mg1-xZrxB2 bulk samples fabricated by the solid state reaction at ambient pressure on phase compositions, microstructure and flux pinning behavior were investigated by using XRD, SQUID magnetometer, SEM and TEM. Critical current density Jc can be significantly enhanced by the Zr-doping and the best data are achieved in Mg0.9Zr0.1B2. For this sample, Jc values are remarkably improved to 1.83×106 A/cm2 in self-field and 5.51×105 A/cm2 in 1 T at 20 K. Also, high quality MgB2/Ta/Cu wires and tapes with and without Ti-doping, MgB2/Fe wires and 18 filament MgB2/NbZr/Cu tapes were fabricated by the powder-in-tube (PIT) method at ambient pressure. The phase compositions, microstructure features and flux pinning properties were studied. The results suggest that Fe is thebest metal for these sheaths. MgB2/Fe wires exhibit very high Jc at high temperatures and high fields. Jc values reach as high as 1.43×105 A/cm2 (4.2 K, 4 T) and 3.72×104 A/cm2 (15 K, 4 T).

  15. Applications of the superconducting lossless resistor in electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Qian Ping; Chen Jiyan; Hua Rong; Chen Zhongming

    2003-04-15

    The main features and some very useful applications of the superconducting lossless resistor (LLR) in electric power systems are introduced in this paper. According our opinion, there are two different kinds of LLR, i.e., the time-variant LLR (Tv-LLR) and the time-invariant LLR (Ti-LLR). First, Tv-LLR is well suited for developing new type of the fault-current limiter (FCL) since it has no heat energy dissipated from its superconducting element during current-limiting process. Second, it may be used to produce the high voltage circuit breaker with current limiting ability. While Ti-LLR may be used to manufacture a new type of the superconducting transformer, with compact volume, lightweight and with continuously regulated turn-ratio (so it familiarized as time-variable transformer, TVT)

  16. Mechanical properties of high-temperature superconducting wires. Ph.D. Thesis - Illinois Inst. of Tech.

    Science.gov (United States)

    Goretta, K. C.; Cluff, J. A.; Joo, J.; Lanagan, M. T.; Singh, J. P.; Vasanthamohan, N.; Xin, Y.; Wong, K. W.

    1995-01-01

    Bending strength, fracture toughness, and elastic modulus data were acquired for YBa2Cu3O(x), Bi2Sr2CaCu2O(x) (Bi,Pb)2Sr2Ca2Cu3O(x), and Tl2Ba2Ca2Cu3O(x) bars. These data and thermal expansion coefficients strongly suggest that the maximum possible tensile strain without fracture of bulk tapes or wires is approximately equals 0.2%. In Ag-clad conductors, residual stresses will be of limited benefit, but fractures produced by larger strains can be accommodated by shunting current through the Ag.

  17. Superconductivity

    CERN Document Server

    Poole, Charles P; Creswick, Richard J; Prozorov, Ruslan

    2014-01-01

    Superconductivity, Third Edition is an encyclopedic treatment of all aspects of the subject, from classic materials to fullerenes. Emphasis is on balanced coverage, with a comprehensive reference list and significant graphics from all areas of the published literature. Widely used theoretical approaches are explained in detail. Topics of special interest include high temperature superconductors, spectroscopy, critical states, transport properties, and tunneling. This book covers the whole field of superconductivity from both the theoretical and the experimental point of view. This third edition features extensive revisions throughout, and new chapters on second critical field and iron based superconductors.

  18. Amorphous magnetostrictive wires used in delay lines for sensing applications

    CERN Document Server

    Hristoforou, E

    2002-01-01

    In this paper we give a review on the use of amorphous magnetostrictive wires in delay lines for sensing applications. Initially, we demonstrate the engineering model of the operation of magnetostrictive delay lines (MDL), illustrating the micro-strain generation, propagation and detection. Accordingly, we present the developed sensing elements based on this technique. The sensing elements are based on the parameters affecting the operation of the MDL, which are the ambient field, the interrogating electromagnetic field and the mechanical action on the magnetic element. Finally, we discuss on the development of a new magnetostrictive device, which incorporate the excitation and sensing means and can be used in sensing applications.

  19. Effect of the wire geometry and an externally applied magnetic field on the detection efficiency of superconducting nanowire single-photon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lusche, Robert; Semenov, Alexey; Huebers, Heinz-Willhelm [DLR, Institut fuer Planetenforschung, Berlin (Germany); Ilin, Konstantin; Siegel, Michael [Karlsruher Institut fuer Technologie (Germany); Korneeva, Yuliya; Trifonov, Andrey; Korneev, Alexander; Goltsman, Gregory [Moscow State Pedagogical University (Russian Federation)

    2013-07-01

    The interest in single-photon detectors in the near-infrared wavelength regime for applications, e.g. in quantum cryptography has immensely increased in the last years. Superconducting nanowire single-photon detectors (SNSPD) already show quite reasonable detection efficiencies in the NIR which can even be further improved. Novel theoretical approaches including vortex-assisted photon counting state that the detection efficiency in the long wavelength region can be enhanced by the detector geometry and an applied magnetic field. We present spectral measurements in the wavelength range from 350-2500 nm of the detection efficiency of meander-type TaN and NbN SNSPD with varying nanowire line width from 80 to 250 nm. Due to the used experimental setup we can accurately normalize the measured spectra and are able to extract the intrinsic detection efficiency (IDE) of our detectors. The results clearly indicate an improvement of the IDE depending on the wire width according to the theoretic models. Furthermore we experimentally found that the smallest detectable photon-flux can be increased by applying a small magnetic field to the detectors.

  20. Improvement in microstructure and superconducting properties of single-filament powder-in-tube MgB2 wires by cold working with a swaging machine

    Science.gov (United States)

    Saito, Yusuke; Murakami, Masato; Matsumoto, Akiyoshi; Kumakura, Hiroaki

    2017-06-01

    We investigated the influence of the mechanical deformation method of wire fabrication on the microstructure and superconducting properties of single-filament in situ powder-in-tube (PIT) MgB2 wires. We employed three deformation methods to fabricate the wires: only swaging, groove rolling + roller drawing, and groove rolling + conventional drawing. We found that cold working by swaging has three advantages over the groove rolling + drawing method: (1) improved uniformity of the MgB2 core along the longitudinal direction; (2) higher mass density of the Mg + B (MgB2) core before (after) heat treatment (HT); and (3) well-developed fiber structures of Mg (MgB2) before (after) HT. These three factors greatly enhanced the critical current density (J c) values of PIT MgB2 wires. The highest J c values were obtained through mechanical deformation by swaging for both pure and carbon-doped wires. A J c value of 3.5 × 104 A cm-2 and an engineering critical current density (J e) of 1.1 × 104 A cm-2 were recorded at 4.2 K and 10 T for a swaged wire of 4.5%-carbon-coated boron powder heat-treated at 600 °C for 1 h.

  1. Permanent superconducting magnets for space applications

    Science.gov (United States)

    Weinstein, Roy

    1994-01-01

    Work has been done to develop superconducting trapped field magnets (TFM's) and to apply them to a bumper-tether device for magnetic docking of spacecraft. The quality parameters for TFM's are J(c), the critical current of the superconductor, and d, the diameter of the superconducting tile. During this year we have doubled d, for production models, from 1 cm to 2 cm. This was done by means of seeding, an improved temperature profile in processing, and the addition of 1 percent Pt to the superconductor chemistry. Using these tiles we have set increasing records for the fields' permanent magnets. Magnets fabricated from old 1 cm tiles trapped 1.52 Tesla at 77K, 4.0T at 65K and 7.0T at 55K. The second of these fields broke a 17 year old record set at Stanford. The third field broke our own record. More recently using 2 cm tiles, we have trapped 2.3T at 77K, and 5.3T at 65K. We expect to trap lOT at 55K in this magnet in the near future. We have also achieved increases in J(c) using a method we developed for seeding U-235, and subsequently bombarding with neutrons. This method doubles J(c). We have not yet fabricated magnets from these tiles. During this year we have increased production yields from 15 percent to 95 percent. We have explored the properties of a magnetic bumper-tether for spacecraft. We have measured the bumper forces, and their dependence on time, distance, and the field of the ordinary ferromagnet (used together with a TFM). We have accounted for 85 percent of the collision energy, and its transformation to magnetic energy and heat energy. We have learned to control the relative bumper and tether forces by controlling TFM and ferromagnetic field strengths.

  2. Texture in state-of-the-art Nb3Sn multifilamentary superconducting wires

    CERN Document Server

    Scheuerlein, C; Alknes, P; Jimenez, N; Bordini, B; Ballarino, A; Di Michiel, M; Thilly, L; Besara, T; Siegrist, T

    2014-01-01

    The texture of Nb3Sn in recent multifilamentary composite wires has been studied by neutron diffraction, synchrotron x-ray diffraction and electron backscatter diffraction. In powder-in-tube (PIT) type superconductors the Nb precursor filaments exhibit a strong 〈110〉 fiber texture as a consequence of the severe cold drawing process, and a 〈110〉 texture is also observed in the Nb3Sn. In the Nb–Ta precursor of the restacked rod process (RRP) strand there is an additional texture component, and in both Ta-alloyed and Ti-alloyed RRP type conductors the Nb3Sn grains grow with a preferential 〈100〉 orientation.

  3. Electronic coolers based on superconducting tunnel junctions: fundamentals and applications

    OpenAIRE

    2014-01-01

    International audience; Thermo-electric transport at the nano-scale is a rapidly developing topic, in particular in superconductor-based hybrid devices. In this review paper, we first discuss the fundamental principles of electronic cooling in mesoscopic superconducting hybrid structures, the related limitations and applications. We review recent work performed in Grenoble on the effects of Andreev reflection, photonic heat transport, phonon cooling, as well as on an innovative fabrication te...

  4. Evaluation of Young’s modulus of MgB2 filaments in composite wires for the superconducting links for the high-luminosity LHC upgrade

    Science.gov (United States)

    Sugano, Michinaka; Ballarino, Amalia; Bartova, Barbora; Bjoerstad, Roger; Gerardin, Alexandre; Scheuerlein, Christian

    2016-02-01

    MgB2 wire is a promising superconductor for the superconducting links for the high-luminosity upgrade of the large Hadron collider at CERN. The mechanical properties of MgB2 must be fully quantified for the cable design, and in this study, we evaluate the Young’s modulus of MgB2 filaments in wires with a practical level of critical current. The Young’s moduli of MgB2 filaments by two different processes, in situ and ex situ, were compared. Two different evaluation methods were applied to an in situ MgB2 wire, a single-fiber tensile test and a tensile test after removing Monel. In addition, the Young’s modulus of the few-micron-thick Nb-Ni reaction layer in an ex situ processed wire was evaluated using a nanoindentation testing technique to improve the accuracy of analysis based on the rule of mixtures. The Young’s moduli of the in situ and ex situ MgB2 wires were in the range of 76-97 GPa and no distinct difference depending on the fabrication process was found.

  5. submitter Evaluation of Young’s modulus of MgB2 filaments in composite wires for the superconducting links for the high-luminosity LHC upgrade

    CERN Document Server

    Sugano, Michinaka; Bartova, Barbora; Bjoerstad, Roger; Gerardin, Alexandre; Scheuerlein, Christian

    2015-01-01

    MgB2 wire is a promising superconductor for the superconducting links for the high-luminosity upgrade of the large Hadron collider at CERN. The mechanical properties of MgB2 must be fully quantified for the cable design, and in this study, we evaluate the Young's modulus of MgB2 filaments in wires with a practical level of critical current. The Young's moduli of MgB2 filaments by two different processes, in situ and ex situ, were compared. Two different evaluation methods were applied to an in situ MgB2 wire, a single-fiber tensile test and a tensile test after removing Monel. In addition, the Young's modulus of the few-micron-thick Nb–Ni reaction layer in an ex situ processed wire was evaluated using a nanoindentation testing technique to improve the accuracy of analysis based on the rule of mixtures. The Young's moduli of the in situ and ex situ MgB2 wires were in the range of 76–97 GPa and no distinct difference depending on the fabrication process was found.

  6. A multiscale and multiphysics model of strain development in a 1.5 T MRI magnet designed with 36 filament composite MgB2 superconducting wire

    Science.gov (United States)

    Amin, Abdullah Al; Baig, Tanvir; Deissler, Robert J.; Yao, Zhen; Tomsic, Michael; Doll, David; Akkus, Ozan; Martens, Michael

    2016-05-01

    High temperature superconductors such as MgB2 focus on conduction cooling of electromagnets that eliminates the use of liquid helium. With the recent advances in the strain sustainability of MgB2, a full body 1.5 T conduction cooled magnetic resonance imaging (MRI) magnet shows promise. In this article, a 36 filament MgB2 superconducting wire is considered for a 1.5 T full-body MRI system and is analyzed in terms of strain development. In order to facilitate analysis, this composite wire is homogenized and the orthotropic wire material properties are employed to solve for strain development using a 2D-axisymmetric finite element analysis (FEA) model of the entire set of MRI magnet. The entire multiscale multiphysics analysis is considered from the wire to the magnet bundles addressing winding, cooling and electromagnetic excitation. The FEA solution is verified with proven analytical equations and acceptable agreement is reported. The results show a maximum mechanical strain development of 0.06% that is within the failure criteria of -0.6% to 0.4% (-0.3% to 0.2% for design) for the 36 filament MgB2 wire. Therefore, the study indicates the safe operation of the conduction cooled MgB2 based MRI magnet as far as strain development is concerned.

  7. Influence of the introduction and formation of artificial pinning centers on the transport properties of nanostructured Nb{sub 3}Sn superconducting wires

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, L B S; Rodrigues, C A; Bormio-Nunes, C; Oliveira, N F Jr; Rodrigues, D Jr, E-mail: lucas_sarno@ppgem.eel.usp.b, E-mail: durval@demar.eel.usp.b [Superconductivity Group, Department of Materials Engineering (DEMAR) Escola de Engenharia de Lorena (EEL), Universidade de Sao Paulo - USP Polo Urbo-Industrial, Gleba AI-6 - PO Box 116 - Lorena, SP (Brazil)

    2009-05-01

    The formation of nanostructures projected to act as pinning centers is presented as a highly promising technique for the transport properties optimization of superconductors. However, due to the necessity of nanometric dimensions of these pinning centers, the heat treatment (HT) profiles must be carefully analyzed. The present work describes a methodology to optimize the HT profiles in respect to diffusion, reaction and formation of the superconducting phases. After the HT, samples were removed for micro structural characterization. Measurements of transport properties were performed to analyze the influence of the introduction of artificial pinning centers (APC) on the superconducting phase and to find the flux pinning mechanism acting in these wires. Fitting the volumetric pinning force vs. applied magnetic field (F{sub p} vs. mu{sub o}H) curves of transport properties, we could determine the type and influence of flux pinning mechanism acting in the global behavior of the samples. It was concluded that the maximum current densities were obtained when normal phases (due to the introduction of the APCs) are the most efficient pinning centers in the global behavior of the samples. The use of HT with profile 220{sup 0}C/100h+575{sup 0}C/50h+650{sup 0}C/100h was found as the best treatment for these nanostructured superconducting wires.

  8. A defect detection method for MgB2 superconducting and iron-based Ba(Fe,Co)2As2 wires

    Science.gov (United States)

    Gajda, D.; Morawski, A.; Zaleski, A.; Yamamoto, A.; Cetner, T.

    2016-04-01

    In this article, a method allowing for the detection of damage in iron-based superconducting bulks and MgB2 wires is presented. MgB2 wires were made of in situ material with ex situ MgB2 barrier. The iron superconductor studied was Ba(Fe,Co)2As2. This material was surrounded by Nb barrier and placed inside an iron tube. All samples were annealed in the isostatic pressure of 1 GPa. Transport measurements were made using a four-contact probe. The transition of Nb and ex situ MgB2 barrier from superconducting into resistive state (first transition) was observed at a temperature range from 5 K to 10 K and can be attributed to damage in either the Nb or ex situ MgB2 barrier in these samples. For samples with a damaged barrier, it was not possible to determine the critical current density of the wires. The analysis indicates that annealing at 1 GPa leads to the Ba(Fe,Co)2As2 material with critical temperatures of 27 K and 21.5 K at upper critical flux density (Bc2) of 14 T.

  9. A fully superconducting bearing system for flywheel applications

    Science.gov (United States)

    Xu, Ke-xi; Wu, Dong-jie; Jiao, Y. L.; Zheng, M. H.

    2016-06-01

    A fully superconducting magnetic suspension structure has been designed and constructed for the purpose of superconducting bearing applications in flywheel energy storage systems. A thrust type bearing and two journal type bearings, those that are composed of melt textured high-Tc superconductor YBCO bulks and Nd-Fe-B permanent magnets, are used in the bearing system. The rotor dynamical behaviors, including critical speeds and rotational loss, are studied. Driven by a variable-frequency three-phase induction motor, the rotor shaft attached with a 25 kg flywheel disc can be speeded up to 15 000 rpm without serious resonance occurring. Although the flywheel system runs stably in the supercritical speeds region, very obvious rotational loss is unavoidable. The loss mechanism has been discussed in terms of eddy current loss and hysteresis loss.

  10. Application concepts of small regenerative cryocoolers in superconducting magnet systems

    Science.gov (United States)

    van der Laan, M. T. G.; Tax, R. B.; ten Kate, H. H. J.

    Superconducting magnets are in growing use outside laboratories for example MRI scanners in hospitals. Other applications under development are magnet systems for separation, levitated trains and ship propulsion. The application of cryocoolers can make these systems more practical. Interfacing these cryocoolers to the magnets can be designed in several different ways. The four basic methods will be dealt with. Test results of a realized GM cryocooler-SC magnet system will be shown. It handles about a 1:3 scale MRI magnet of which one of the six coils has been successfully tested at temperatures between 10 and 14 K.

  11. Differences in the effects of turns and constrictions on the resistive response in current-biased superconducting wire after single photon absorption

    Science.gov (United States)

    Zotova, A. N.; Y Vodolazov, D.

    2013-07-01

    We study how turns and constrictions affect the resistive response of superconducting wire after instantaneous, localized heating, by modeling the absorption of a single photon by the wire. We find that the presence of constrictions favors the detection of photons with a range of energies whereas the presence of turns increases the ability to detect only relatively ‘low’ energy photons. The main reason is that in the case of a constriction the current density is increased over the whole length and width of the constriction while in the case of a turn the current density is enhanced only near the inner corner of the turn. This results in inhomogeneous Joule heating near the turn and worsens the conditions for the appearance of the normal domain at relatively small currents, where the ‘high’ energy photons could already create a normal domain in the straight part of the wire. We also find that the amplitude of the voltage pulse depends on the location at which the photon is absorbed, being smallest when the photon is absorbed near the turn and largest when the photon is absorbed near the constriction. This effect is due to the difference in the resistance of constrictions and turns in the normal state from the resistance of the rest of the wire.

  12. A new RHQT Nb3Al superconducting wire with a Ta/Cu/Ta three-layer filament-barrier structure

    Science.gov (United States)

    Takeuchi, Takao; Tsuchiya, Kiyosumi; Nakagawa, Kazuhiko; Nimori, Shigeki; Banno, Nobuya; Iijima, Yasuo; Kikuchi, Akihiro; Nakamoto, Tatsushi

    2012-06-01

    To suppress the low-magnetic-field instability (flux jumps in low magnetic fields) of a rapid-heating, quenching and transformation (RHQT) processed Nb3Al superconductor, we had previously modified the cross-sectional design of an RHQT Nb3Al by adopting a Ta filament-barrier structure. Unlike Nb barriers, Ta barriers are not superconducting in magnetic fields at 4.2 K so that they electromagnetically decouple filaments. However, small flux jumps still occurred at 1.8 K, which is a typical operating temperature for the magnets used in high-energy particle accelerators. Furthermore, poor bonding at the Ta/Ta interface between neighboring Ta-coated jelly-roll (JR) filaments frequently caused precursor wires to break during drawing. To overcome these problems, we fabricated a new RHQT Nb3Al wire with a Ta/Cu/Ta three-layer filament-barrier structure for which an internal stabilization technique (Cu rods encased in Ta are dispersed in the wire cross section) was extended. Removing the Ta/Ta interface in the interfilamentary barrier (JR filament/Ta/Cu/Ta/JR filament) allowed precursor wires to be drawn without breaking. Furthermore, the Cu filament barrier electromagnetically decoupled filaments to suppress flux jumps at 1.8 K. The ductile Cu layer also improved the bending strain tolerance of RHQT Nb3Al.

  13. Utilization of superconductivity in energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, J.T.; Mikkonen, R.; Lahtinen, M.; Paasi, J. [Tampere Univ. of Technology (Finland). Laboratory of Electricity and Magnetism

    1998-12-31

    The technical potential of high temperature superconductors has been demonstrated in energy power applications. The magnetisation coils of the constructed 1.5 kW synchronous motor are made of bismuth-based material, the efficiency of the motor being 82 %. The same material is utilised in a 5 kJ magnetic energy storage in order to compensate for a short-term loss of power. Fast activation time and high efficiency are the benefits compared to traditional UPS systems. The operation temperature of 20-30 K enables the usage of mechanical cooling which is one major advantage compared to conventional liquid helium cooled systems. (orig.)

  14. Applications of surface analysis in the wire industry

    Science.gov (United States)

    Stout, David A.

    The quality of wire is judged not only by its physical properties such as tensile strength and fatigue resistance, but also by its surface finish. The surface roughness, oxide formation, cleanliness, and plating homogeneity and porosity are just a few of the surface properties than can influence the performance of a wire product. Coupled to this is the large amount of surface area generated in drawing wire. For example, a ten pound spool holds nine miles of 0.006″ diameter stainless steel wire. For these reasons surface analysis has become important both to the manufacturer and consumer of wire products. When surface analysis equipment such as AES, ESCA, and SIMS was first becoming commercially available in the late sixties and early seventies, the wire industry was beginning to enter a phase of technological development for many of its products. Wire manufacturers and users began using surface analysis to investigate such topics as adhesion of brass plated automobile tire cord to rubber and diffusion of layered deposits. Examples of surface analysis used for process control, problem solving, and project development include discoloration problems on stainless steel wire, welding problems with composite wires, diffusion formed brass coatings, and diffusion problems with solder coated and Cu plated steel wire.

  15. Application of ultra-thin polymer coating on metallic wires

    OpenAIRE

    Yu, Juan

    1992-01-01

    In this study, the coating of fine wires using hydrodynamic pressure technique has been investigated theoretically and experimentally. One of the principal aims of the project is to establish the minimum possible coating thickness on fine wires which can be applied by means of hydrodynamic technique. Models based on steady, uniform and laminar flow of Newtonian as well as non-Newtonian fluid for polymer coating for the process of plasto-hydrodynamic wire coating in a stepped bore unit have be...

  16. Fractal-based modeling of the stress-strain relation of Bi2Sr2CaCu2Ox/AgMg superconducting round wires

    Science.gov (United States)

    Gou, Xiaofan; Schwartz, Justin

    2013-10-01

    Bi2Sr2CaCu2Ox/AgMg (Bi2212) multi filamentary superconducting round wires (RWs) can be only potential candidate for constructing the superconducting magnet with higher magnetic field (>25T). Very complicated microstructure of Bi2212 RWs has been found by recent SEM studies, and then the vital problems of Characterization of this unique microstructure and further exploration of the correlation of macro electromechanical properties with this microstructure arise. In this paper, it is firstly found that the rough surface of individual filaments can be well characterized by fractals. On the geometrical model with the fractal simulation of the rough surface, stress-strain relation of Bi2212 RWs has been investigated. The modelling result with considering the rough surface has a better agreement to the experimental data. At the request of the authors, and with the agreement of the Proceedings Editor, the above paper in AIP Proceedings has been retracted (as of 26 November 2013) due to a prior publication by the authors which reports similar data/results. That paper was first published in volume 26 (issue 5) of the journal Superconductor Science and Technology and was published on 4 April 2013: Fractal analysis of the role of the rough interface between Bi2Sr2CaCu2Ox filaments and the Ag matrix in the mechanical behavior of composite round wires The authors wish to apologize for any inconvenience caused by publication of their AIP Proceedings article.

  17. Texturing of high T(sub c) superconducting polycrystalline fibers/wires by laser-driven directional solidification in an thermal gradient

    Science.gov (United States)

    Varshney, Usha; Eichelberger, B. Davis, III

    1995-01-01

    This paper summarizes the technique of laser-driven directional solidification in a controlled thermal gradient of yttria stabilized zirconia core coated Y-Ba-Cu-O materials to produce textured high T(sub c) superconducting polycrystalline fibers/wires with improved critical current densities in the extended range of magnetic fields at temperatures greater than 77 K. The approach involves laser heating to minimize phase segregation by heating very rapidly through the two-phase incongruent melt region to the single phase melt region and directionally solidifying in a controlled thermal gradient to achieve highly textured grains in the fiber axis direction. The technique offers a higher grain growth rate and a lower thermal budget compared with a conventional thermal gradient and is amenable as a continuous process for improving the J(sub c) of high T(sub c) superconducting polycrystalline fibers/wires. The technique has the advantage of suppressing weak-link behavior by orientation of crystals, formation of dense structures with enhanced connectivity, formation of fewer and cleaner grain boundaries, and minimization of phase segregation in the incongruent melt region.

  18. Recent Advances in Iron-Based Superconducting Wires and Tapes%新型铁基超导线带材的研究进展

    Institute of Scientific and Technical Information of China (English)

    林鹤; 马衍伟

    2013-01-01

    新型铁基超导材料具有较高的临界转变温度、超高的上临界场和非常小的各向异性等优点,在高场磁体领域应用前景广阔。目前粉末装管法已广泛应用于铁基超导线带材的制备,临界电流密度在4.2 K和10 T下高达1.7×104 A/cm2,接近实用化水平。首先介绍了铁基超导材料的典型结构与基本超导特性,详细评述了铁基超导粉末的合成和粉末装管法的工艺流程,主要包括元素配比、热处理工艺以及粉末装管原位法和先位法的对比分析,重点探讨了影响线带材临界电流密度的因素及其关键制备技术。通过包套材料的选择、掺杂改性、热等静压和轧制织构等方法来解决线带材中包套与超导芯易反应、杂相多、致密度低以及晶界弱连接等难题。此外还简要介绍了多芯线带材的最新研究进展。最后,对铁基超导线带材的发展趋势做了展望。%The newly discovered iron-based superconductors have caused great interest for high-field applications due to their good properties such as high transition temperature , ultrahigh upper critical field and low anisotropy .The iron-based superconducting wires and tapes are commonly prepared by the powder-in-tube ( PIT) process.In this paper, we focus on the fabrication techniques to realize high Jc values such as chemical composition , optimal heating conditions , sheath mate-rial, doped elements, hot isostatic press and rolling texture, particularly for the 122-type pnictide wires and tapes.Excit-ingly, so far high transport Jc value of 1.7 ×104 A/cm2 at 4.2 K and 10 T has been obtained in iron-based tapes, closed to the practical level.Finally, a perspective and future development of PIT pnictide wires and tapes are given .

  19. Superconducting RF Technology R&D for Future Accelerator Applications

    CERN Document Server

    Reece, Charles E

    2012-01-01

    Superconducting rf technology (SRF) is evolving rapidly as are its applications. While there is active exploitation of what one may term the current state-of-the-practice, there is also rapid progress expanding in several dimensions the accessible and useful parameter space. While state-of-the-art performance sometimes outpaces thorough understanding, the improving scientific understanding from active SRF research is clarifying routes to obtain optimum performance from present materials and opening avenues beyond the standard bulk niobium. The improving technical basis understanding is enabling process engineering to both improve performance confidence and reliability and also unit implementation costs. Increasing confidence in the technology enables the engineering of new creative application designs. We attempt to survey this landscape to highlight the potential for future accelerator applications.

  20. A KBE Application for Automatic Aircraft Wire Harness Routing

    NARCIS (Netherlands)

    Zhu, Z.; Van Tooren, M.J.L.; La Rocca, G.

    2012-01-01

    Wire harness design is an increasingly complex task. Knowledge Based Engineering (KBE) and optimization techniques can be used to support designers in handling this complexity. The wire harness design process can be divided in three main parts, namely electrical design, configuration design and geom

  1. Effect on deformation process of adding a copper core to multifilament MgB2 superconducting wire

    DEFF Research Database (Denmark)

    Hancock, Michael Halloway; Bay, Niels

    2007-01-01

    Using the PIT method, multifilament wire with different packing strategies has been manufactured. In all, three types of wire have been investigated, a 19-filament configuration using ex-situ powder in an Fe-matrix and two 8-filament configurations in an Fe-matrix applying a copper core, one usin...

  2. Superconducting joint making and joint evaluation between multi-filamentary Nb{sub 3}Sn wires; Nb{sub 3}Sn tashin senzaikan no chodendo setsuzoku to setsuzokubu no hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, R.; Sairote, S.; Goto, N. [Toyohashi Univ. of Tech., Aichi (Japan)

    1999-06-07

    There is the superconductive connection as a necessary and important technology in manufacturing the superconducting magnet of which MRI and magnetic field stability used in NMR and uniformity are excellent for persistent current mode operation. Though we carry out the development of the superconducting magnet of small refrigerating machine cryogenic, the superconductive connection in which strong magnetic field dick piece and high temperature operation are possible is desirable, when these magnets are operated at the persistent current mode. Then, we tried the development of the technology which carried out superconductive connection of the Nb{sub 3}Sn polycore wire rod that in this study, they are high temperature and strong magnetic field, and that the correspondence is possible at Nb{sub 3}Sn. (NEDO)

  3. Study on Recovery Performance of High Tc Superconducting Tapes for Resistive Type Superconducting Fault Current Limiter Applications

    Science.gov (United States)

    kar, Soumen; Kulkarni, Sandeep; Dixit, Manglesh; Singh, Kuwar Pal; Gupta, Alok; Balasubramanyam, P. V.; Sarangi, S. K.; Rao, V. V.

    Recent advances in reliable production of long length high temperature superconducting (HTS) tapes have resulted in commercial application of superconducting fault current limiters (SFCLs) in electrical utility networks. SFCL gives excellent technical performance when compared to conventional fault current limiters. The fast self-recovery from normal state to superconducting state immediately after the fault removal is an essential criterion for resistive type SFCL operation. In this paper, results on AC over-current testing of 1st generation (1G) Bi2223 tapes and 2nd generation (2G) YBCO coated conductors operating at 77 K are reported. From these results, the recovery time is estimated for different available HTS tapes in the market. The current limiting tests have also been performed to study the effective current limitation. Further, the recovery characteristics after the current limitation are quantitatively discussed for repetitive faults for different time intervals in the range of 100 ms to few seconds.

  4. Superconducting IF biasing circuit for low-noise cryogenic applications

    Energy Technology Data Exchange (ETDEWEB)

    Dochev, D; Monje, R; Vassilev, V; Belitsky, V, E-mail: dimitar.dochev@chalmers.s [Department of Radio and Space Science, Chalmers University of Technology, S-412 96 Gothenburg (Sweden)

    2010-06-01

    A planar superconducting circuit designed for use in low-noise cryogenic applications is presented. The circuit is a bias-T combined with a 4-8 GHz impedance matching circuitry, which employs entirely planar design with a novel layout. The proposed and tested circuitry is intended to be used with a SIS mixer and incorporates a double section transformer based on microstrip line technology with a total impedance transformation of 5:1 within the frequency band. One of the transformer sections employs a three-line coupled line, which also serves as a DC block capacitor. The microstrip lines were manufactured using superconducting Nb metallization, which provides a conduction loss-free solution at the operation temperature of 4 K. S-parameter measurements at 4 K temperature were performed and found to be in a good agreement with the simulations. The device measured return loss is better than -10 dB within the frequency band. Furthermore, the circuit was tested as a part of 385 - 500 GHz double sideband heterodyne SIS receiver demonstrating a flat noise temperature response of 80 - 90 K over the entire IF band of 4 - 8 GHz.

  5. Synthesis of chemical vapor deposition graphene on tantalum wire for supercapacitor applications

    Science.gov (United States)

    Li, Mingji; Guo, Wenlong; Li, Hongji; Xu, Sheng; Qu, Changqing; Yang, Baohe

    2014-10-01

    This paper studies the synthesis and electrochemical characterization of graphene/tantalum (Ta) wires as high-performance electrode material for supercapacitors. Graphene on Ta wires is prepared by the thermal decomposition of methane under various conditions. The graphene nanosheets on the Ta wire surface have an average thickness of 1.3-3.4 nm and consist typically of a few graphene monolayers, and TaC buffer layers form between the graphene and Ta wire. A capacitor structure is fabricated using graphene/Ta wire with a length of 10 mm and a diameter of 0.6 mm as the anode and Pt wire of the same size as the cathode. The electrochemical behavior of the graphene/Ta wires as supercapacitor electrodes is characterized by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy in 1 M Na2SO4 aqueous electrolyte. The as-prepared graphene/Ta electrode has highest capacitance of 345.5 F g-1 at current density of 0.5 A g-1. The capacitance remains at about 84% after 1000 cycles at 10 A g-1. The good electrochemical performance of the graphene/Ta wire electrode is attributed to the unique nanostructural configuration, high electrical conductivity, and large specific surface area of the graphene layer. This suggests that graphene/Ta wire electrode materials have potential applications in high-performance energy storage devices.

  6. Synthesis of chemical vapor deposition graphene on tantalum wire for supercapacitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mingji, E-mail: limingji@163.com [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Guo, Wenlong [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Li, Hongji, E-mail: hongjili@yeah.net [Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China); Xu, Sheng [School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072 (China); Qu, Changqing; Yang, Baohe [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China)

    2014-10-30

    Highlights: • The capacitance of graphene/tantalum (Ta) wire electrodes is firstly reported. • Graphene was grown on the Ta surface by hot-filament chemical vapor deposition. • Graphene/Ta wire structure is favorable for fast ion and electron transfer. • The graphene/Ta wire electrode shows high capacitive properties. - Abstract: This paper studies the synthesis and electrochemical characterization of graphene/tantalum (Ta) wires as high-performance electrode material for supercapacitors. Graphene on Ta wires is prepared by the thermal decomposition of methane under various conditions. The graphene nanosheets on the Ta wire surface have an average thickness of 1.3–3.4 nm and consist typically of a few graphene monolayers, and TaC buffer layers form between the graphene and Ta wire. A capacitor structure is fabricated using graphene/Ta wire with a length of 10 mm and a diameter of 0.6 mm as the anode and Pt wire of the same size as the cathode. The electrochemical behavior of the graphene/Ta wires as supercapacitor electrodes is characterized by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy in 1 M Na{sub 2}SO{sub 4} aqueous electrolyte. The as-prepared graphene/Ta electrode has highest capacitance of 345.5 F g{sup −1} at current density of 0.5 A g{sup −1}. The capacitance remains at about 84% after 1000 cycles at 10 A g{sup −1}. The good electrochemical performance of the graphene/Ta wire electrode is attributed to the unique nanostructural configuration, high electrical conductivity, and large specific surface area of the graphene layer. This suggests that graphene/Ta wire electrode materials have potential applications in high-performance energy storage devices.

  7. Progress on applications of high temperature superconducting microwave filters

    Science.gov (United States)

    Chunguang, Li; Xu, Wang; Jia, Wang; Liang, Sun; Yusheng, He

    2017-07-01

    In the past two decades, various kinds of high performance high temperature superconducting (HTS) filters have been constructed and the HTS filters and their front-end subsystems have been successfully applied in many fields. The HTS filters with small insertion loss, narrow bandwidth, flat in-band group delay, deep out-of-band rejection, and steep skirt slope are reviewed. Novel HTS filter design technologies, including those in high power handling filters, multiband filters and frequency tunable filters, are reviewed, as well as the all-HTS integrated front-end receivers. The successful applications to various civilian fields, such as mobile communication, radar, deep space detection, and satellite technology, are also reviewed.

  8. Superconducting Vacuum-Gap Crossovers for High Performance Microwave Applications

    CERN Document Server

    Denis, Kevin L; Chang, Meng-Ping; Hu, Ron; U-Yen, Kongpop; Wollack, Edward

    2016-01-01

    The design and fabrication of low-loss wide-bandwidth superconducting vacuum-gap crossovers for high performance millimeter wave applications are described. In order to reduce ohmic and parasitic losses at millimeter wavelengths a vacuum gap is preferred relative to dielectric spacer. Here, vacuum-gap crossovers were realized by using a sacrificial polymer layer followed by niobium sputter deposition optimized for coating coverage over an underlying niobium signal layer. Both coplanar waveguide and microstrip crossover topologies have been explored in detail. The resulting fabrication process is compatible with a bulk micro-machining process for realizing waveguide coupled detectors, which includes sacrificial wax bonding, and wafer backside deep reactive ion etching for creation of leg isolated silicon membrane structures. Release of the vacuum gap structures along with the wax bonded wafer after DRIE is implemented in the same process step used to complete the detector fabrication

  9. Summary of the Proceedings of the Super-Conductivity Technical Exchange Meeting

    Science.gov (United States)

    1980-04-01

    Contents: Large Superconductive Magnets; Superconductivity Activities at LASL; Superconductivity Studies at Argonne National Laboratory; CFFF MHD Magnet at Argonne National Laboratory; MHD Superconducting Magnets; Fermilab's Energy Saver; LCP and 12 Tesla Programs at ORNL; Division of Electric Energy System's Superconductivity Program; Development of Standards for Practical Superconductors; Casting of Dendritic Cu-Nb Alloys for Superconducting Wire; Review of Recent Developments of Multifilamentary Nb3Sn by 'in Situ' and Cold Powder Metallurgy Processes; Superconducting Magnet Facility at NRL; Airborne Superconductor Applications; High Pressure Synthesis Program at Benet Weapons Laboratory Watervliet Arsenal; CuCl; Stability and Exciton Population Percursive to Anomalous Diagmagnetism; Navy Superconductive Machinery Development Program; and Superconducting Materials Program at NRL.

  10. Application of cold drawn lamellar microstructure for developing ultra-high strength wires

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Composite materials having lamellar structure are known to have a good combination of high strength and ductility. They are widely used in the fields of automobiles, civil engineering and construction, machines and many other industries. An application of lamellar microstructure for developing ultra-high strength steel wires was studied and discussed. Based on the experimental results,the relationships between the strength increase and microstructure development during the cold wire drawing were studied to reveal the strengthening mechanism. As cold drawing proceeds, the wire strength extremely increases, the microstructure changes from large single crystal lamellar structure to very fine polycrystalline lamellar one which has nano-sized grains, high dislocation density and amorphous regions. From the results obtained, it is concluded that heavy cold drawing technique is an effective method for lamellar composite to get high strength wires. Furthermore, formation process of the best microstructure for producing the ultra-high strength wires was also discussed.

  11. Outcomes of Clinical Application of Boomerang Closure Wire System

    Institute of Scientific and Technical Information of China (English)

    Jian-sheng WU; Wen-bin WEI; Yu-jia WANG; Xin-xia ZHANG; Xue-song HU

    2009-01-01

    Objectives To evaluate the efficacy and safety of clinical application of a novel type of vascular closure device named Boomerang closure wire system (BCWS). Methods BCWSs were used in 288 patients (BCWSs group) for hemostasis after transfernoral coronary angiography (CAG) or percutaneous coronary intervention (PCI). Device suc-cess rate, hemostasis success rate, manual compression time, recumbent time, minor peripheral complication rate, se-vere peripheral complication rate and hospital staying time after procedure were analyzed. Results were compared to those from 300 patients (control group) who received manual compression in our hospital during the same period. Results In BCWS group, device success rate was 97.2 %, hemostasis success rate was 95.1%. Manual compression time in CAG subgroup and PCI subgroup was 7.8 min and 11.2 min, respectively. Recumbent time was 136. 3 min in CAG subgroup, 284.6 min in PCI subgroup. Minor peripheral complication rate was 4.5 %, severe peripheral compli-cation rate was 2.4 %. Hospital-staying time after procedure in CAG group and PCI group was 1.8 d and 6.6 d, re-spectively. Compared to control group, manual compression time, recumbent time and hospital-staying time of BCWSs group had statistical significance; hemostasis success rate, minor peripheral complication rate and severe peripheral complication rate of BCWSs group bad no statistical difference. Conclusions BCWS provides satisfied haemostatic effect. Compared to routine manual compression, BCWS shortens manual compression time, recumbent time and hos-pital staying time.

  12. WTEC Panel on Power applications of superconductivity in Japan and Germany. Final report

    CERN Document Server

    Shelton, R D; Larbalestier, D; Schwall, R E; Sokolowski, R S; Suenaga, M; Willis, J E O

    1997-01-01

    In early 1996, the U.S. Department of Energy and National Science Foundation asked the World Technology Evaluation Center (WTEC) to assemble a panel to assess, relative to the United States, how Japan and Germany are responding to the challenge of applying superconductivity to power and energy applications. Although the study was focused mostly on the impact of high-temperature superconductors (HTS) on the power applications field, the WTEC panel also looked at many applications for low-temperature superconductors (LTS). The market for low-temperature superconductor applications is well established, as is that for superconducting electronics, for which there is a separate WTEC panel. The panel on power applications of superconductivity was commissioned to identify the roles of public organizations, industry, and academia for advancing power applications of superconductivity, taking both a present and a long-term view.

  13. Effect of the wire width and magnetic field on the detection efficiency of superconducting nanowire single-photon detectors; Einfluss von Geometrie und magnetischem Feld auf die Effizienz supraleitender Nanodraht-Einzelphotonendetektoren

    Energy Technology Data Exchange (ETDEWEB)

    Lusche, Robert

    2015-06-24

    The aim of this thesis is to a gain deeper understanding of the single photon detection process in superconducting nanowire single-photon detectors (SNSPDs). A detailed knowledge of the physical principles and mechanisms which the detection process is based on helps to improve specific detector parameters and hence the suitability of such detectors for various applications. Several theoretical models of the detection process have been compared to the results of measurements of photon and dark count rates in meander-type TaN- and NbN-SNSPDs with different wire-widths in a broad range of wavelengths, transport currents and magnetic fields. In the first part of the thesis, measurements of the photon and dark count rates of TaN- and NbN-SNSPDs with varying wire width are described. For each meander spectra of the intrinsic detection efficiency (IDE) were derived. The IDE represents the probability that the SNSPD generates a measurable voltage pulse upon absorption of a photon. The recorded IDE spectra have shown a characteristic cut-off wavelength up to which photons were detected with a probability of 100 per cent. Furthermore it was found that the cut-off wavelengths increases linearly with the increase in the inverse wire width. This observation is best explained by the refined hot spot model. The second part of the thesis describes the influence of magnetic field on the photon and dark count rates of NbN-SNSPDs. In order to apply magnetic fields to the meanders a continuous-flow inset for mobile 4He storage dewars was constructed. It was shown for the first time, that the photon count rate exhibits a magnetic field dependence. Furthermore it could be shown that the measured dependence of the photon and dark count rate on the magnetic field is in good agreement with the theoretical model of vortex-assisted photon detection in narrow superconducting lines. Hence, within this thesis it could be confirmed that magnetic vortices are involved in the single photon

  14. Current Sharing Technology in Transmission Conductors of Cold Dielectric High Temperature Superconducting Cables Using Second-generation HTS Wires

    Institute of Scientific and Technical Information of China (English)

    ZHU Jiahui; BAO Xuzheng; QIU Ming

    2012-01-01

    The cold dielectric high temperature superconducting (CD HTS) cable has multilayer conductors. The non-uniform AC current distribution in these multilayer conductors will increase the AC loss and decrease the current transmission efficiency. So it is important to understand the current sharing among layers in order to fully exploit the performance of the HTS cable.

  15. Flow Cooling of Superconducting Magnets for Spacecraft Applications

    Science.gov (United States)

    Dietz, A. J.; Audette, W. E.; Barton, M. D.; Hilderbrand, J. K.; Marshall, W. S.; Rey, C. M.; Winter, D. S.; Petro, A. J.

    2008-03-01

    The development and testing of a flow cooling system for high-temperature superconducting (HTS) magnets is described. The system includes a turbo-Brayton cryocooler, a magnet thermal interface, and a magnet thermal isolation and support system. The target application is the Variable Specific Impulse Magnetoplasma Rocket (VASIMR). Turbo-Brayton coolers are well suited to such spacecraft applications, as they are compact, modular, lightweight, and efficient, with long maintenance-free lifetimes. Furthermore, the technology scales well to high-cooling capacities. The feasibility of using turbo-Brayton coolers in this application was proven in a design exercise in which existing cooler designs were scaled to provide cooling for the magnet sets required by 200 kW and 1 MW VASIMR engines. The performance of the concepts for the thermal interface and the thermal isolation and support system were measured in separate laboratory tests with a demonstration system built about a representative HTS magnet. Cooling for these tests was provided by a flow cooling loop comprising a compressor, recuperator and GM cryocooler, with the flow pressure, temperature, and mass flow rate selected to effectively simulate the turbo-Brayton operating condition. During system testing, the magnet was cooled below its design operating temperature of 35 K, and good thermal uniformity (<0.4 K) and low thermal loads (<0.5 W) were demonstrated.

  16. Normal domain temperature profile in second generation HTS tape wire

    OpenAIRE

    Malginov, Andrey V; Kuntsevich, Alexander Yu; Malginov, Vladimir A; Fleishman, Leonid S

    2013-01-01

    Background Studies of the normal zone in high-temperature superconducting wires are extremely important for power applications, such as fault current limiters, motors, cables etc. We studied the temperature distribution and normal domain propagation in high-temperature superconducting YBCO tape with highly resistive substrate. Findings For applied voltages exceeding a certain threshold value the normal domain was found to become unstable and started to propagate along the tape. Conclusions Th...

  17. Radiation-crosslinked polyethylene for wire and cable applications

    Science.gov (United States)

    Ueno, Keiji; Uda, Ikujiro; Tada, Shotaro

    Polyethylene is used as an insulation material for wires and cables because of its excellent electrical properties. Polyethylene is also a typical irradiated crosslinked polymer. The characteristics of irradiated polyethylene, the effects of density, molecular weight and so on, were studied.

  18. Magnesium diboride(MgB{sub 2}) wires for applications

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Dipak; Kim, Jung Ho [Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong (Australia)

    2016-03-15

    Field and temperature dependence of the critical current density, Jc, were measured for both un-doped and carbon doped MgB{sub 2}/Nb/Monel wires manufactured by Hyper Tech Research, Inc. In particular, carbon incorporation into the MgB{sub 2} structure using malic acid additive and a chemical solution method can be advantageous because of the highly uniform mixing between the carbon and boron powders. At 4.2 K and 10 T, Jc was estimated to be 25,000 - 25,300 Acm{sup -2} for the wire sintered at 600 degrees C for 4 hours. The irreversibility field, Birr, of the malic acid doped wire was approximately 21.0 - 21.8 T, as obtained from a linear extrapolation of the J-B characteristic. Interestingly enough, the Jc of the malic acid doped sample exceeds 10{sup 5} Acm{sup -2} at 6 T and 4.2 K, which is comparable to that of commercial Nb-Ti wires.

  19. Method and system for controlling chemical reactions between superconductors and metals in superconducting cables

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Tengming

    2016-11-15

    A method, system, and apparatus for fabricating a high-strength Superconducting cable comprises pre-oxidizing at least one high-strength alloy wire, coating at least one Superconducting wire with a protective layer, and winding the high-strength alloy wire and the Superconducting wire to form a high-strength Superconducting cable.

  20. Technical training: RF superconductivity and accelerator cavity applications

    CERN Multimedia

    Technical Training

    2016-01-01

    We are happy to announce a new training course organised by the TE-VSC group in the field of the physics and applications of superconductors. The course provides an overview and update of the theory of radiofrequency and superconductors:   RF Superconductivity and Accelerator Cavity Applications https://cern.ch/course/?164VAC19 One timetable only:  Tuesday, 8 March 2016: from 2 p.m. to 4 p.m. Wednesday, 9 March 2016: from 9.30 a.m to 11.30 a.m. Thursday, 10 March 2016: from 9.30 a.m to 11.30 a.m. Monday, 14 March 2016: from 9.30 a.m to 11.30 a.m. Tuesday, 15 March 2016: from 9.30 a.m to 11.30 a.m. Wednesday, 16 March 2016: from 9.30 a.m to 11.30 a.m. Thursday, 17 March 2016: from 9.30 a.m to 11.30 a.m. Target audience: Experts in radiofrequency or solid state physics (PhD level). Pre-requisites: Basic knowledge of quantum physics and superc...

  1. Battery energy storage and superconducting magnetic energy storage for utility applications: A qualitative analysis

    Energy Technology Data Exchange (ETDEWEB)

    Akhil, A.A.; Butler, P.; Bickel, T.C.

    1993-11-01

    This report was prepared at the request of the US Department of Energy`s Office of Energy Management for an objective comparison of the merits of battery energy storage with superconducting magnetic energy storage technology for utility applications. Conclusions are drawn regarding the best match of each technology with these utility application requirements. Staff from the Utility Battery Storage Systems Program and the superconductivity Programs at Sandia National contributed to this effort.

  2. At the Frontiers of Science Superconductivity and Its Electric Power Applications

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-07-01

    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

  3. Preliminary study of HTS magnet using 2G wires for maglev train

    Science.gov (United States)

    Ogata, Masafumi; Miyazaki, Yoshiki; Hasegawa, Hitoshi; Sasakawa, Takashi; Nagashima, Ken

    2010-06-01

    There are several advantages by applying a high temperature superconducting wire to an on-board superconducting magnet for the maglev train. At first, an increase of thermal capacity of superconducting coils contributes a stability of the superconducting state of the coils. In addition, a reliability of superconducting magnet improves by simplification of the magnet structure. And the weight of the superconducting magnet and the energy consumption of the on-board cryocooler will decrease. Therefore, we examined the possibility on application of the 2G wire with a high critical current density in a high magnetic field. We performed numerical analysis regarding the weight of a superconducting magnet and the energy consumption of an on-board cryocooler in consideration of the characteristics of the 2G wire. Furthermore, we have carried out the Ic measurement for the commercial 2G wires under various experimental conditions such as temperature, magnetic field strength and angle. We also performed the trial manufacture and evaluation of Ic characteristics for the small race track-shaped superconducting coil.

  4. Basic study of HTS magnet using 2G wires for maglev train

    Science.gov (United States)

    Ogata, M.; Miyazaki, Y.; Hasegawa, H.; Sasakawa, T.; Nagashima, K.

    2010-11-01

    There are several advantages by applying a high-temperature superconducting wire to an on-board superconducting magnet for the maglev train. At first, an increase of thermal capacity of superconducting coils contributes a stability of the superconducting state of the coils. In addition, a reliability of superconducting magnet improves by simplification of the magnet structure. And the weight of the superconducting magnet and the energy consumption of the on-board cryocooler will decrease. Therefore, we examined the possibility on application of the 2G wire with a high critical current density in a high magnetic field. We performed numerical analysis regarding the weight of a superconducting magnet and the energy consumption of an on-board cryocooler in consideration of the characteristics of the 2G wire. Furthermore, we have carried out the Ic measurement for the commercial 2G wires under various experimental conditions such as temperature, magnetic field strength and angle. We also performed the trial manufacture and evaluation of Ic characteristics for the small race track-shaped superconducting coil.

  5. Basic study of HTS magnet using 2G wires for maglev train

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, M., E-mail: ogata@rtri.or.j [Railway Technical Research Institute, 2-8-38, Hikari-cho, Kokubunji-shi, Tokyo 185-8540 (Japan); Miyazaki, Y.; Hasegawa, H.; Sasakawa, T.; Nagashima, K. [Railway Technical Research Institute, 2-8-38, Hikari-cho, Kokubunji-shi, Tokyo 185-8540 (Japan)

    2010-11-01

    There are several advantages by applying a high-temperature superconducting wire to an on-board superconducting magnet for the maglev train. At first, an increase of thermal capacity of superconducting coils contributes a stability of the superconducting state of the coils. In addition, a reliability of superconducting magnet improves by simplification of the magnet structure. And the weight of the superconducting magnet and the energy consumption of the on-board cryocooler will decrease. Therefore, we examined the possibility on application of the 2G wire with a high critical current density in a high magnetic field. We performed numerical analysis regarding the weight of a superconducting magnet and the energy consumption of an on-board cryocooler in consideration of the characteristics of the 2G wire. Furthermore, we have carried out the I{sub c} measurement for the commercial 2G wires under various experimental conditions such as temperature, magnetic field strength and angle. We also performed the trial manufacture and evaluation of I{sub c} characteristics for the small race track-shaped superconducting coil.

  6. Preliminary study of HTS magnet using 2G wires for maglev train

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, Masafumi; Miyazaki, Yoshiki; Hasegawa, Hitoshi; Sasakawa, Takashi; Nagashima, Ken, E-mail: ogata@rtri.or.j [Railway Technical Research Institute, Hikari-cho 2-8-38, Kokubunji-shi, Tokyo (Japan)

    2010-06-01

    There are several advantages by applying a high temperature superconducting wire to an on-board superconducting magnet for the maglev train. At first, an increase of thermal capacity of superconducting coils contributes a stability of the superconducting state of the coils. In addition, a reliability of superconducting magnet improves by simplification of the magnet structure. And the weight of the superconducting magnet and the energy consumption of the on-board cryocooler will decrease. Therefore, we examined the possibility on application of the 2G wire with a high critical current density in a high magnetic field. We performed numerical analysis regarding the weight of a superconducting magnet and the energy consumption of an on-board cryocooler in consideration of the characteristics of the 2G wire. Furthermore, we have carried out the I{sub c} measurement for the commercial 2G wires under various experimental conditions such as temperature, magnetic field strength and angle. We also performed the trial manufacture and evaluation of I{sub c} characteristics for the small race track-shaped superconducting coil.

  7. Energized overhead ground wires - OHGWs the pioneer Brazilian application

    Energy Technology Data Exchange (ETDEWEB)

    D`Ajuz, Ary; Martinez, Manuel L.B.; Araujo, Ana Maria R.; Takai, Mario Noboru; Sganzerla, Flavio [ELETRONORTE, Brasilia, DF (Brazil); O. Junior, Helio P.; Fonseca, Claudio S. [Marte Engenharia (Brazil); Guimaraes, R.P.; Mendes, Eloisa R.

    1994-12-31

    This paper introduces an economical solution for close HV lines small villages and farms load supply. The needed modifications to adapt a planned transmission system to supply loads located along the lines routes are presented. The paper describes the two overhead ground wires scheme planned for implementation in the 230 kV transmission line under construction by ELETRONORTE in Mato Grosso and Rondonia supplying loads each one totaling roughly 8 MW. (author) 4 refs., 4 figs., 2 tabs.

  8. Deployable robotic woven wire structures and joints for space applications

    Science.gov (United States)

    Shahinpoor, MO; Smith, Bradford

    1991-01-01

    Deployable robotic structures are basically expandable and contractable structures that may be transported or launched to space in a compact form. These structures may then be intelligently deployed by suitable actuators. The deployment may also be done by means of either airbag or spring-loaded typed mechanisms. The actuators may be pneumatic, hydraulic, ball-screw type, or electromagnetic. The means to trigger actuation may be on-board EPROMS, programmable logic controllers (PLCs) that trigger actuation based on some input caused by the placement of the structure in the space environment. The actuation may also be performed remotely by suitable remote triggering devices. Several deployable woven wire structures are examined. These woven wire structures possess a unique form of joint, the woven wire joint, which is capable of moving and changing its position and orientation with respect to the structure itself. Due to the highly dynamic and articulate nature of these joints the 3-D structures built using them are uniquely and highly expandable, deployable, and dynamic. The 3-D structure naturally gives rise to a new generation of deployable three-dimensional spatial structures.

  9. Muon spin rotation studies of niobium for superconducting rf applications

    Directory of Open Access Journals (Sweden)

    A. Grassellino

    2013-06-01

    Full Text Available In this work we investigate superconducting properties of niobium samples via application of the muon spin rotation/relaxation (μSR technique. We employ for the first time the μSR technique to study samples that are cut out from large and small grain 1.5 GHz radio frequency (rf single cell niobium cavities. The rf test of these cavities was accompanied by full temperature mapping to characterize the rf losses in each of the samples. Results of the μSR measurements show that standard cavity surface treatments like mild baking and buffered chemical polishing performed on the studied samples affect their surface pinning strength. We find an interesting correlation between high field rf losses and field dependence of the sample magnetic volume fraction measured via μSR. The μSR line width observed in zero-field-μSR measurements matches the behavior of Nb samples doped with minute amounts of Ta or N impurities. A lower and an upper bound for the upper critical field H_{c2} of these cutouts is found.

  10. Monitoring of multiphase flows for superconducting accelerators and others applications

    Science.gov (United States)

    Filippov, Yu. P.; Kakorin, I. D.; Kovrizhnykh, A. M.; Miklayev, V. M.

    2017-07-01

    This paper is a review on implementation of measuring systems for two-phase helium, hydrogen, liquefied natural gas (LNG), and oil-formation/salty water flows. Two types of such systems are presented. The first type is based on two-phase flow-meters combining void fraction radio-frequency (RF) sensors and narrowing devices. They can be applied for superconducting accelerators cooled with two-phase helium, refueling hydrogen system for space ships and some applications in oil production industry. The second one is based on combination of a gamma-densitometer and a narrowing device. These systems can be used to monitor large two-phase LNG and oil-formation water flows. An electronics system based on a modular industrial computer is described as well. The metrological characteristics for different flow-meters are presented and the obtained results are discussed. It is also shown that the experience gained allows separationless flow-meter for three-phase oil-gas-formation water flows to be produced.

  11. Application of superconducting magnesium diboride (MGB2) in superconducting radio frequency cavities

    Science.gov (United States)

    Tan, Teng

    The superconductivity in magnesium diboride (MgB2) was discovered in 2001. As a BCS superconductor, MgB2 has a record-high Tc of 39 K, high Jc of > 107 A/cm2 and no weak link behavior across the grain boundary. All these superior properties endorsed that MgB2 would have great potential in both power applications and electronic devices. In the past 15 years, MgB2 based power cables, microwave devices, and commercial MRI machines emerged and the next frontier are superconducting radio frequency (SRF) cavities. SRF cavities are one of the leading accelerator technologies. In SRF cavities, applied microwave power generates electrical fields that accelerate particle beams. Compared with other accelerator techniques, SRF cavity accelerators feature low loss, high acceleration gradients and the ability to accelerate continuous particle beams. However, current SRF cavities are made from high-purity bulk niobium and work at 2 K in superfluid helium. The construction and operational cost of SRF cavity accelerators are very expensive. The demand for SRF cavity accelerators has been growing rapidly in the past decade. Therefore, a lot of effort has been devoted to the enhancement of the performance and the reduction of cost of SRF cavities. In 2010, an acceleration gradient of over 50 MV/m has been reported for a Nb-based SRF cavity. The magnetic field at the inner surface of such a cavity is ~ 1700 Oe, which is close to the thermodynamic critical field of Nb. Therefore, new materials and technologies are required to raise the acceleration gradient of future SRF cavity accelerators. Among all the proposed approaches, using MgB2 thin films to coat the inner surface of SRF cavities is one of the promising tactics with the potential to raise both the acceleration gradient and the operation temperature of SRF cavity accelerators. In this work, I present my study on MgB2 thin films for their application in SRF cavities. C-epitaxial MgB2 thin films grown on SiC(0001) substrates

  12. Superconductivity in nanowires

    CERN Document Server

    Bezryadin, Alexey

    2012-01-01

    The importance and actuality of nanotechnology is unabated and will be for years to come. A main challenge is to understand the various properties of certain nanostructures, and how to generate structures with specific properties for use in actual applications in Electrical Engineering and Medicine.One of the most important structures are nanowires, in particular superconducting ones. They are highly promising for future electronics, transporting current without resistance and at scales of a few nanometers. To fabricate wires to certain defined standards however, is a major challenge, and so i

  13. High performance superconducting radio frequency ingot niobium technology for continuous wave applications

    Energy Technology Data Exchange (ETDEWEB)

    Dhakal, Pashupati, E-mail: dhakal@jlab.org; Ciovati, Gianluigi, E-mail: gciovati@jlab.org; Myneni, Ganapati R., E-mail: rao@jlab.org [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

    2015-12-04

    Future continuous wave (CW) accelerators require the superconducting radio frequency cavities with high quality factor and medium accelerating gradients (≤20 MV/m). Ingot niobium cavities with medium purity fulfill the specifications of both accelerating gradient and high quality factor with simple processing techniques and potential reduction in cost. This contribution reviews the current superconducting radiofrequency research and development and outlines the potential benefits of using ingot niobium technology for CW applications.

  14. High critical current of Ti-sheathed MgB{sub 2} wires for AC and weight-critical applications

    Energy Technology Data Exchange (ETDEWEB)

    Alessandrini, M; Fang, H; Hanna, M; Putman, P; Zhou, Y X; Salama, K [Department of Mechanical Engineering and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-4006 (United States)

    2006-01-15

    The peculiar features of magnesium diboride make it suitable for many potential applications. In the last four years of investigation of MgB{sub 2}, the scientific community's research was mainly motivated by features such as low cost, compatibility with straightforward processing methods, relatively high critical temperature, and absence of weak links between grains. Other applications suggest the accentuation of other MgB{sub 2} properties. In particular its very low mass density makes it attractive for space activities, where the cost per kilogram for orbiting is still a huge obstacle, e.g. the cost of transport to low Earth orbit can reach 15 k$ kg{sup -1}. In order to promote the use of this compound for space activities, we tested titanium as a sheath material. Titanium is non-magnetic and its alloys are almost half the weight of steel but with yield stresses up to three times higher. We fabricated Ti-sheathed MgB{sub 2} through the powder-in-tube process. These wires show similar results to those sheathed with Fe. At 4 K the critical current density J{sub c} is well above 7 x 10{sup 5} A cm{sup -2}. The interface between the superconducting intermetallic compound and the lightweight sheath does not show any evidence of reaction and diffusion up to 900 deg. C. An analysis was carried out using x-ray diffraction, scanning electron microscopy with an energy dispersive spectrometer, and electron microprobe analysis.

  15. Development of large bore superconducting magnet for wastewater treatment application

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hui Ming; Xu, Dong; Shen, Fuzhi; Zhang, Hengcheng; Li, Lafeng [State Key Laboratory of Technologies in Space Cryogenic Propellants, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing (China)

    2017-03-15

    Water issue, especially water pollution, is a serious issue of 21st century. Being an significant technique for securing water resources, superconducting magnetic separation wastewater system was indispensable. A large bore conduction-cooled magnet was custom-tailored for wastewater treatment. The superconducting magnet has been designed, fabricated and tested. The superconducting magnet was composed of NbTi solenoid coils with an effective horizontal warm bore of 400 mm and a maximum central field of 2.56T. The superconducting magnet system was cooled by a two-stage 1.5W 4K GM cryocooler. The NbTi solenoid coils were wound around an aluminum former that is thermally connected to the second stage cold head of the cryocooler through a conductive copper link. The temperature distribution along the conductive link was measured during the cool-down process as well as at steady state. The magnet was cooled down to 4.8K in approximately 65 hours. The test of the magnetic field and quench analysis has been performed to verify the safe operation for the magnet system. Experimental results show that the superconducting magnet reached the designed magnetic performance.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-31

    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.

  17. The Effect of Sintering Temperature on The Rolled Silver-Sheathed Monofilament Bi,Pb-Sr-Ca-Cu-O Superconducting Wire

    Science.gov (United States)

    Hendrik; Sebleku, P.; Siswayanti, B.; Pramono, A. W.

    2017-05-01

    The manufacture of high critical temperature (Tc) Bi, Pb-Sr-Ca-Cu-O (HTS BPSCCO) superconductor wire fabricated by power-in-tube (PIT) is a multi-step process. The main difficulty is that the value of Tc superconductor wire determined by various factors for each step. The objective of this research is to investigate the effect of sintering parameters on the properties of final rolled material. The fabrication process of 1 m rolled-silver sheath monofilament superconductor BPSCCO wire using mechanical deformation process including rolling and drawing has been carried out. The pure silver powders were melted and formed into pure silver (Ag) tube. The tube was 10 mm in diameter with a sheath material: superconductor powders ratio of about 6 : 1. Starting powders, containing the nominal composition of Bi2-Sr2-Cam-1-Cum-Oy, were inserted into the pure silver tube and rolled until it reached a diameter of 4 mm. A typical area reduction ratio of about 5% per step has been proposed to prevent microcracking during the cold-drawing process. The process of rolling of the silver tube was subsequently repeated to obtain three samples and then followed by heat-treated at 820 °C, 840 °C, and 860 °C, respectively. The surface morphology was analyzed by using SEM; the crystal structure was studied by using X-RD, whereas the superconductivity was investigated by using temperature dependence resistivity measurement by using four-point probe technique. SEM images showed the porosity of the cross-sectional surface of the samples. The sample with low heating temperature showed porosity more than the one with high temperature. The value of critical temperature (Tc) of the sample with a dwelling time of heating of 8 hours is 70 K. At above 70 K, it shows the behavior of conductor properties. However, the porosity increased as the heating time increased up to 24 hours. The critical temperature was difficult to be identified due to its porosity. According to XRD results, the Bi-2212

  18. Microstructure of MgB{sub 2} superconducting wire prepared by internal magnesium diffusion and in-situ powder-in-tube processes – Secondary phase intergrain nanolayers as an oxygen content indicator

    Energy Technology Data Exchange (ETDEWEB)

    Rosová, A., E-mail: alica.rosova@savba.sk; Kováč, P.; Hušek, I.; Brunner, B.; Dobročka, E.

    2015-09-15

    Highlights: • We compared microstructure of undoped MgB{sub 2} wires made by in-situ PIT and IMD. • The main differences were in MgB{sub 2} density and volume ratio of amorphous MgO. • Thin oriented layers of secondary phases were observed between MgB{sub 2} plate grains. • Only MgO or only Mg oriented layers were in the PIT or IMD samples, resp. • High MgB{sub 2} density and low MgO{sub 2} content caused higher J{sub c} of IMD wire. - Abstract: We analyzed microstructure of two undoped MgB{sub 2} single core wires prepared by two different technologies – in-situ powder-in-tube (PIT) technology and internal magnesium diffusion (IMD) processes. Their microstructure showed mainly different densities of superconducting material, corresponding content of pores and the volume ratio of amorphous MgO phase. We observed a special microstructural feature – thin oriented secondary phase layers on grain boundaries of plate-shaped MgB{sub 2} grains. The significant decrease of oxygen content in IMD wire was reflected in the presence of thin oriented Mg layers while in PIT wire thin oriented MgO layers were observed. The microstructure difference is reflected in increased critical current density J{sub c} of the IMD wire in comparison to the PIT one.

  19. Micromachined hot-wire thermal conductivity probe for biomedical applications.

    Science.gov (United States)

    Yi, Ming; Panchawagh, Hrishikesh V; Podhajsky, Ronald J; Mahajan, Roop L

    2009-10-01

    This paper presents the design, fabrication, numerical simulation, and experimental validation of a micromachined probe that measures thermal conductivity of biological tissues. The probe consists of a pair of resistive line heating elements and resistance temperature detector sensors, which were fabricated by using planar photolithography on a glass substrate. The numerical analysis revealed that the thermal conductivity and diffusivity can be determined by the temperature response induced by the uniform heat flux in the heating elements. After calibrating the probe using a material (agar gel) of known thermal conductivity, the probe was deployed to calculate the thermal conductivity of Crisco. The measured value is in agreement with that determined by the macro-hot-wire probe method to within 3%. Finally, the micro thermal probe was used to investigate the change of thermal conductivity of pig liver before and after RF ablation treatment. The results show an increase in thermal conductivity of liver after the RF ablation.

  20. Fracture behaviour and its relation to critical current of silver-sheathed Ba2YCu3O(7-x) superconducting composite wires and tapes

    Science.gov (United States)

    Ochiai, Shojiro; Hayashi, Kenji; Osamura, Kozo

    1990-08-01

    Silver-sheathed Ba2YCu3O(7-x) superconducting composite wires and tapes were prepared by rolling, drawing, swaging and pressing methods. The fracture behavior and its influence on critical current at 0T at 77 K of the Ba2YCu3O(7-x) were investigated. The oxide was found to show multiple fracture under applied tensile stress, and the critical current density and tensile strength of the oxide in the rolled, swaged and pressed samples were higher than those in the drawn samples. When the working amount was high, the current density and the strength of the oxide were found to become high. Within the present conditions, there was a correlation between critical current density and cracking stress: the higher the cracking stress, the higher the critical current density became. The cracking stress of the present oxide was determined to be 50 MPa at most, being far lower than that of the Nb3Sn compound (800 to 2000 MPa). The critical current density of the rolled, swaged and pressed samples was reduced rapidly when exerted stress on the oxide exceeded the cracking stress, while the reduction in the drawn samples occurred gradually. A strong dependence of the critical current, as a function of applied stress and cracking stress of the oxide, on the measured portion due to scatter in the size of defects contained in the oxide, was found.

  1. International round robin test of the retained critical current after double bending at room temperature of Ag-sheathed Bi-2223 superconducting wires

    Science.gov (United States)

    Yamada, Y.; Nishijima, G.; Osamura, K.; Shin, H. S.; Goldacker, W.; Breschi, M.; Ribani, P.

    2016-02-01

    An international round robin test was carried out in order to establish a test method for retained critical current after double bending at room temperature of Ag-sheathed Bi-2223 superconducting wires. Tests for commercial Bi-2223 tape were conducted by six laboratories using the same guidelines. The standard uncertainties (SUs) of measurands were evaluated for these four quantities: I C0, I C/I C080, I C/I C060, I C/I C050, where, I C0 is initial critical current and I C /I C0XX is critical current after XX mm bending. Using an F test to determine where the most scatter was generated in the test results it was found that the greatest scatter in the normalized critical current measurements came from inter-laboratory scatter. In a type-B uncertainty evaluation, the major contribution was from the bending diameter and measuring temperature. The relative SU tended to increase as the bending diameter decreased. A specific mandrel diameter corresponding to a retained critical current of 95% could be determined with a relative SU of 1.3%. In order to reduce the overall scatter, the temperature difference between the critical current measurements before and after bending should be small.

  2. Superconducting Pb stripline resonators in parallel magnetic field and their application for microwave spectroscopy

    Science.gov (United States)

    Ebensperger, Nikolaj G.; Thiemann, Markus; Dressel, Martin; Scheffler, Marc

    2016-11-01

    Planar superconducting microwave resonators are key elements in a variety of technical applications and also act as sensitive probes for microwave spectroscopy of various materials of interest in present solid state research. Here superconducting Pb is a suitable material as a basis for microwave stripline resonators. To utilize Pb stripline resonators in a variable magnetic field (e.g. in ESR measurements), the electrodynamics of such resonators in a finite magnetic field has to be fully understood. Therefore we performed microwave transmission measurements (with ample applied power to work in linear response) on superconducting Pb stripline resonators in a variable, parallel magnetic field. We determined surface resistance, penetration depth, as well as real and imaginary parts, {σ }1 and {σ }2, of the complex conductivity of superconducting Pb as a function of a magnetic field. Here we find features reminiscent of those in temperature-dependent measurements, such as a maximum in {σ }1 (coherence peak). At magnetic fields above the critical field of this type-I superconductor we still find a low-loss microwave response, which we assign to remaining superconductivity in the form of filaments within the Pb. Hysteresis effects are found in the quality factor of resonances once the swept magnetic field has exceeded the critical magnetic field. This is due to normal conducting areas that are pinned and can therefore persist in the superconducting phase. Besides zero-field-cooling we show an alternative way to eliminate these even at T\\lt {T}c. Based on our microwave data, we also determine the critical magnetic field and the critical temperature of Pb in a temperature range between 1.6 K and 6.5 K and magnetic fields up to 140 mT, showing good agreement with BCS predictions. We also study a Sn sample in a Pb resonator to demonstrate the applicability of superconducting Pb stripline resonators in the experimental study of other (super-)conducting materials in a

  3. Superconducting microfabricated ion traps

    CERN Document Server

    Wang, Shannon X; Labaziewicz, Jaroslaw; Dauler, Eric; Berggren, Karl; Chuang, Isaac L

    2010-01-01

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

  4. Survey of Processing Methods for High Strength High Conductivity Wires for High Field Magnet Applications

    Energy Technology Data Exchange (ETDEWEB)

    Han, K.; Embury, J.D.

    1998-10-01

    This paper will deal with the basic concepts of attaining combination of high strength and high conductivity in pure materials, in-situ composites and macrocomposites. It will survey current attainments, and outline where some future developments may lie in developing wire products that are close to the theoretical strength of future magnet applications.

  5. Superconductivity applications for infrared and microwave devices; Proceedings of the Meeting, Orlando, FL, Apr. 19, 20, 1990

    Science.gov (United States)

    Bhasin, Kul B. (Editor); Heinen, Vernon O. (Editor)

    1990-01-01

    Various papers on superconductivity applications for IR and microwave devices are presented. The individual topics addressed include: pulsed laser deposition of Tl-Ca-Ba-Cu-O films, patterning of high-Tc superconducting thin films on Si substrates, IR spectra and the energy gap in thin film YBa2Cu3O(7-delta), high-temperature superconducting thin film microwave circuits, novel filter implementation utilizing HTS materials, high-temperature superconductor antenna investigations, high-Tc superconducting IR detectors, high-Tc superconducting IR detectors from Y-Ba-Cu-O thin films, Y-Ba-Cu0-O thin films as high-speed IR detectors, fabrication of a high-Tc superconducting bolometer, transition-edge microbolometer, photoresponse of YBa2Cu3O(7-delta) granular and epitaxial superconducting thin films, fast IR response of YBCO thin films, kinetic inductance effects in high-Tc microstrip circuits at microwave frequencies.

  6. A strain gradient plasticity theory with application to wire torsion

    KAUST Repository

    Liu, J. X.

    2014-06-05

    Based on the framework of the existing strain gradient plasticity theories, we have examined three kinds of relations for the plastic strain dependence of the material intrinsic length scale, and thus developed updated strain gradient plasticity versions with deformation-dependent characteristic length scales. Wire torsion test is taken as an example to assess existing and newly built constitutive equations. For torsion tests, with increasing plastic strain, a constant intrinsic length predicts too high a torque, while a decreasing intrinsic length scale can produce better predictions instead of the increasing one, different from some published observations. If the Taylor dislocation rule is written in the Nix-Gao form, the derived constitutive equations become singular when the hardening exponent gets close to zero, which seems questionable and calls for further experimental clarifications on the exact coupling of hardening due to statistically stored dislocations and geometrically necessary dislocations. Particularly, when comparing the present model with the mechanism-based strain gradient plasticity, the present model satisfies the reciprocity relation naturally and gives different predictions even under the same parameter setting. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  7. Coated Conductors for the Magnetic Bearing Application

    Science.gov (United States)

    Sass, Felipe; Dias, Daniel Henrique Nogueira; Sotelo, Guilherme Gonçalves; Júnior, Rubens de Andrade

    The second generation (2G) of superconductor wires have been considered for several applications lately. This work presents a preliminary study of superconducting magnetic bearings (SMB) using 2G wires as passive levitators. A superconducting block using stacked 2G wires was built to evaluate the magnetic bearing behavior, thought levitation force measurements, when a permanent magnet cylinder approaches or moves away from the block. The superconducting block was compared with an YBCO bulk with nearly the same dimensions and the results show a promising potential for this application.

  8. Superconducting electronics

    NARCIS (Netherlands)

    Rogalla, Horst

    1994-01-01

    During the last decades superconducting electronics has been the most prominent area of research for small scale applications of superconductivity. It has experienced quite a stormy development, from individual low frequency devices to devices with high integration density and pico second switching

  9. Damping Models for Shear-Deformable Beam with Applications to Spacecraft Wiring Harness

    Science.gov (United States)

    2014-10-28

    and modified for application to Timoshenko beams. The inclusion of rotary inertia does add some frequency- dependence; however, careful selection of...behavior of wiring harnesses. The emphasis in this project will be on the extension of the shear-beam damping model to the Timoshenko beam, a beam model...approaches) are extended and modified for application to Timoshenko beams. The inclusion of rotary inertia does add some frequency-dependence

  10. Integrated superconducting detectors on semiconductors for quantum optics applications

    Science.gov (United States)

    Kaniber, M.; Flassig, F.; Reithmaier, G.; Gross, R.; Finley, J. J.

    2016-05-01

    Semiconductor quantum photonic circuits can be used to efficiently generate, manipulate, route and exploit nonclassical states of light for distributed photon-based quantum information technologies. In this article, we review our recent achievements on the growth, nanofabrication and integration of high-quality, superconducting niobium nitride thin films on optically active, semiconducting GaAs substrates and their patterning to realize highly efficient and ultra-fast superconducting detectors on semiconductor nanomaterials containing quantum dots. Our state-of-the-art detectors reach external detection quantum efficiencies up to 20 % for ~4 nm thin films and single-photon timing resolutions <72 ps. We discuss the integration of such detectors into quantum dot-loaded, semiconductor ridge waveguides, resulting in the on-chip, time-resolved detection of quantum dot luminescence. Furthermore, a prototype quantum optical circuit is demonstrated that enabled the on-chip generation of resonance fluorescence from an individual InGaAs quantum dot, with a linewidth <15 μeV displaced by 1 mm from the superconducting detector on the very same semiconductor chip. Thus, all key components required for prototype quantum photonic circuits with sources, optical components and detectors on the same chip are reported.

  11. Applications in the Advanced Transportation System and Impact on Superconductivity Industry of Htsm

    Science.gov (United States)

    Zhang, Y. P.; Zhao, Y.

    As the information technology grows up and its application penetrates into every area of this world, how to faster and more efficiently transport people and goods is becoming the new social demand, which indicates a new revolution on advanced transportation technology being brewed. High-temperature Superconductivity Maglev (HTSM) is one with the best development potential among most transportation technologies. It could be used in many advanced transportation fields, overcoming the key contradiction and shortcoming of the current transportation patterns such as train, automobile and airplane. On the other hand, HTSM will promote theoretical study and technology exploitation on superconductivity. HTSM's applications in a large scale will bring up profound effect on the forming and development of the superconductivity industry.

  12. Curvature effect on the mechanical behaviour of a martensitic shape-memory-alloy wire for applications in civil engineering

    Science.gov (United States)

    Tran, Hanh; Balandraud, Xavier; Destrebecq, Jean-François

    2015-02-01

    The mechanical response of a bent shape memory alloy (SMA) wire is a key point for the understanding of the process of the creation of confining effects in a wrapped concrete cylinder for example. The objective of the present study is to model the phenomena involved in the bending of a martensitic SMA wire. The mechanism of martensite reorientation is considered in the model, which also takes into account the asymmetry between tension and compression. For validation purposes, experiments were performed on Ni-Ti wires: measurement of residual curvatures after bending release and tensile tests on pre-bent wires. In particular, the analysis shows a variation in axial stiffness as a function of the preliminary curvature. This result shows the necessity of modelling the distributions of the state variables within the wire cross-section for the simulation of confinement processes using SMA wires. It also opens prospects to potential application to the bending of SMA fibres in smart textiles.

  13. Magnetic characterization of the nickel layer protecting the copper wires in harsh applications

    Directory of Open Access Journals (Sweden)

    Roger Daniel

    2017-06-01

    Full Text Available High Temperature (HT° motor coils open new perspectives for extending the applications of electrical motors or generators to very harsh environments or for designing very high power density machines working with high internal temperature gradients. Over a temperature of 300°C, the classic enameled wire cannot work permanently, the turn-to-turn insulation must be inorganic and made with high temperature textiles or vitro-ceramic compounds. For both cases, a diffusion barrier must protect the copper wire against oxidation. The usual solution consists of adding a nickel layer that yields an excellent chemical protection. Unfortunately, the nickel has ferromagnetic properties that change a lot the skin effect in the HT wire at high frequencies. For many applications such as aeronautics, electrical machines are always associated with PWM inverters for their control. The windings must resist to high voltage short spikes caused by the fast fronted pulses imposed by the feeding inverter. The nickel protection layer of the HT° inorganic wire has a large influence on the high frequency behavior of coils and, consequently, on the magnitude of the voltage spikes. A good knowledge of the non-linear magnetic characteristics of this nickel layer is helpful for designing reliable HT inorganic coils. The paper presents a method able to characterize non-linear electromagnetic properties of this nickel layer up to 500°C.

  14. A novel transport based model for wire media and its application to scattering problems

    Science.gov (United States)

    Forati, Ebrahim

    Artificially engineered materials, known as metamaterials, have attracted the interest of researchers because of the potential for novel applications. Effective modeling of metamaterials is a crucial step for analyzing and synthesizing devices. In this thesis, we focus on wire medium (both isotropic and uniaxial) and validate a novel transport based model for them. Scattering problems involving wire media are computationally intensive due to the spatially dispersive nature of homogenized wire media. However, it will be shown that using the new model to solve scattering problems can simplify the calculations a great deal. For scattering problems, an integro-differential equation based on a transport formulation is proposed instead of the convolution-form integral equation that directly comes from spatial dispersion. The integro-differential equation is much faster to solve than the convolution equation form, and its effectiveness is confirmed by solving several examples in one-, two-, and three-dimensions. Both the integro-differential equation formulation and the homogenized wire medium parameters are experimentaly confirmed. To do so, several isotropic connected wire medium spheres have been fabricated using a rapid-prototyping machine, and their measured extinction cross sections are compared with simulation results. Wire parameters (period and diameter) are varied to the point where homogenization theory breaks down, which is observed in the measurements. The same process is done for three-dimensional cubical objects made of a uniaxail wire medium, and their measured results are compared with the numerical results based on the new model. The new method is extremely fast compared to brute-force numerical methods such as FDTD, and provides more physical insight (within the limits of homogenization), including the idea of a Debye length for wire media. The limits of homogenization are examined by comparing homogenization results and measurement. Then, a novel

  15. A Thermal Analysis of a Hot-Wire Probe for Icing Applications

    Science.gov (United States)

    Struk, Peter M.; Rigby, David L.; Venkataraman, Krishna

    2014-01-01

    This paper presents a steady-state thermal model of a hot-wire instrument applicable to atmospheric measurement of water content in clouds. In this application, the power required to maintain the wire at a given temperature is used to deduce the water content of the cloud. The model considers electrical resistive heating, axial conduction, convection to the flow, radiation to the surroundings, as well as energy loss due to the heating, melting, and evaporation of impinging liquid and or ice. All of these parameters can be varied axially along the wire. The model further introduces a parameter called the evaporation potential which locally gauges the maximum fraction of incoming water that evaporates. The primary outputs of the model are the steady-state power required to maintain a spatially-average constant temperature as well as the variation of that temperature and other parameters along the wire. The model is used to understand the sensitivity of the hot-wire performance to various flow and boundary conditions including a detailed comparison of dry air and wet (i.e. cloud-on) conditions. The steady-state power values are compared to experimental results from a Science Engineering Associates (SEA) Multi-Element probe, a commonly used water-content measurement instrument. The model results show good agreement with experiment for both dry and cloud-on conditions with liquid water content. For ice, the experimental measurements under read the actual water content due to incomplete evaporation and splashing. Model results, which account for incomplete evaporation, are still higher than experimental results where the discrepancy is attributed to splashing mass-loss which is not accounted in the model.

  16. Least Squares Spectral Analysis and Its Application to Superconducting Gravimeter Data Analysis

    Institute of Scientific and Technical Information of China (English)

    YIN Hui; Spiros D. Pagiatakis

    2004-01-01

    Detection of a periodic signal hidden in noise is the goal of Superconducting Gravimeter (SG) data analysis. Due to spikes, gaps, datum shrifts (offsets) and other disturbances, the traditional FFT method shows inherent limitations. Instead, the least squares spectral analysis (LSSA) has showed itself more suitable than Fourier analysis of gappy, unequally spaced and unequally weighted data series in a variety of applications in geodesy and geophysics. This paper reviews the principle of LSSA and gives a possible strategy for the analysis of time series obtained from the Canadian Superconducting Gravimeter Installation (CGSI), with gaps, offsets, unequal sampling decimation of the data and unequally weighted data points.

  17. Effect of Wire Material on Productivity and Surface Integrity of WEDM-Processed Inconel 706 for Aircraft Application

    Science.gov (United States)

    Sharma, Priyaranjan; Chakradhar, D.; Narendranath, S.

    2016-09-01

    Inconel 706 is a recently developed superalloy for aircraft application, particularly in turbine disk which is among the most critical components in the gas turbine engines. Recently, wire electrical discharge machining (WEDM) attained success in machining of gas turbine components which require complex shape profiles with high precision. To achieve the feasibility in machining of these components, the research work has been conducted on Inconel 706 superalloy using WEDM process. And, the effect of different wire materials (i.e., hard brass wire, diffused wire, and zinc-coated wire) on WEDM performance characteristics such as cutting speed, surface topography, surface roughness, recast layer formation, residual stresses, and microstructural and metallurgical alterations have been investigated. Even though, zinc-coated wire exhibits improved productivity, hard brass wire was found to be beneficial in terms of improved surface quality of the machined parts. Additionally, lower tensile residual stresses were obtained with hard brass wire. However, diffused wire has a moderate effect on productivity and surface quality. Under high discharge energy, higher elemental changes were observed and also the white layer was detected.

  18. Magnesium Diboride Superconducting Coils for Electric Propulsion Systems for Large Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The recent development of magnesium diboride superconducting wires makes possible the potential to have much lighter weight superconducting coils for heavy aircraft...

  19. Space applications of superconducting microwave electronics at NASA Lewis Research Center

    Science.gov (United States)

    Leonard, R. F.; Bhasin, K. B.; Romanofsky, R. R.; Cubbage, C. D.; Chorey, C. Z.

    1993-01-01

    Since the discovery of high temperature superconductivity in 1987, NASA Lewis Research Center has been involved in efforts to demonstrate its advantages for applications involving microwave electronics in space, especially space communications. The program included thin film fabrication by means of laser ablation. Specific circuitry which was investigated includes microstrip ring resonators at 32 GHz, phase shifters which utilize a superconducting, optically activated switch, an 8x8 32 GHz superconducting microstrip antenna array, and an HTS-ring-resonator stabilized oscillator at 8 GHz. The latter two components are candidates for use in space experiments which are described in other papers. Experimental data on most of the circuits are presented as well as, in some cases, a comparison of their performance with an identical circuit utilizing gold or copper metallization.

  20. Template Guided Live Wire and Its Application on Automatic Extraction of Tongue in Digital Image

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yuan-jie; YANG Jie; ZHOU Yue

    2005-01-01

    In this paper, we propose a novel automatic object extraction algorithm, named the Template Guided Live Wire, based on the popularly used livewire techniques. We discuss in details the novel method's applications on tongue extraction in digital images. With the guides of a given template curve which approximates the tongue's shape, our method can finish the extraction of tongue without any human intervention. In the paper, we also discussed in details how the template guides the live wire, and why our method functions more effectively than other boundary based segmentation methods especially the snake algorithm. Experimental results on some tongue images areas well provided to show our method's better accuracy and robustness than the snake algorithm.

  1. Development of a Nb 3Sn multifilamentary wire for accelerator magnet applications

    Science.gov (United States)

    Durante, M.; Bredy, P.; Devred, A.; Otmani, R.; Reytier, M.; Schild, T.; Trillaud, F.

    2001-05-01

    CEA/Saclay and Alstom/MSA have carried out a program to develop a Nb 3Sn multifilamentary wire for accelerator magnet applications relying on the internal-tin process. The main wire specifications are: an overall diameter of 0.825 mm, a critical current larger than 405 A at 4.2 K and 7 T, hysteresis losses lower than 450 mJ/cm 3 for a±3 T trapezoidal cycle, and a copper-to-non-copper ratio greater than 1. The last phase of the optimization program was based on four different strands and we present here the results of the characterization tests, including residual resistivity ratio, critical current and AC loss measurements.

  2. Numerical Prediction of Differences in Micromechanical Fracture Sequence in Notched and Un-Notched Wires for Civil Engineering Applications

    Directory of Open Access Journals (Sweden)

    Adewole, K.K.

    2014-01-01

    Full Text Available The need to employ simulation-based investigations of fracture of civil engineering structures has been emphasised recently in literature. In this paper, three dimensional finite element simulations revealed that the cup and cone fracture process in channel-shaped notched wire for civil engineering applications begins with a slant fracture at the root of the outer edge of the channel-shaped notch and follows a slant to flat fracture sequence. These results demonstrate that the fracture origin in cup and cone fracture in notched wires for civil engineering applications does not necessarily begin with a flat fracture at the center of the wire and does not necessarily follows the flat to slant fracture sequence or propagation generally reported in literature. These results further demonstrate the need to employ simulation-based methodologies in conjunction with or as an alternative to purely experimental fractographic analysis for an accurate failure analysis of wires used for civil engineering applications.

  3. Magnetoresistive-superconducting mixed sensors for biomagnetic applications

    Energy Technology Data Exchange (ETDEWEB)

    Pannetier-Lecoeur, M. [DSM/IRAMIS/SPEC, CEA Saclay, 91191 Gif sur Yvette Cedex (France); Fermon, C., E-mail: claude.fermon@cea.f [DSM/IRAMIS/SPEC, CEA Saclay, 91191 Gif sur Yvette Cedex (France); Dyvorne, H.; Jacquinot, J.F.; Polovy, H.; Walliang, A.L. [DSM/IRAMIS/SPEC, CEA Saclay, 91191 Gif sur Yvette Cedex (France)

    2010-05-15

    When coupled to a giant magnetoresistive (GMR) sensor, a superconducting loop containing a constriction can be a very sensitive magnetometer. It has thermal noise levels of few fT/sqrt(Hz), comparable to low-T{sub c} SQUID noise, with a flat frequency response. These mixed sensors are good candidates for detection of weak biomagnetic signals, like a cardiac or neuronal signature. Furthermore, being sensitive to the flux, mixed sensors can be used for nuclear magnetic resonance (NMR) detection and Magnetic Resonance Imaging (MRI) especially at low fields. They are very robust and accept strong RF pulses with a very short recovery time compared to tuned RF coils, which allow measurements of broad signals (short relaxation time or multiple resonances). We will first present the last generation sensors having a noise level of 3 fT/sqrt(Hz) and we will show signals measured at low frequency (magnetocardiography-magnetoencephalography range) and at higher frequency (NMR signals). The use of additional flux transformers for improving the signal-to-noise will be discussed. Finally, we will present perspectives for low-field MRI, which can be combined with neural signal detection (MEG), especially for brain anatomy and temporal response on the same experimental setup.

  4. High Temperature Superconducting Magnets: Revolutionizing Next Generation Accelerators and Other Applications (466th Brookhaven Lecture)

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Ramesh (BNL Superconducting Magnet Division)

    2011-02-16

    BNL has always been a leader in the world of superconducting magnets, which are essential to the great modern ccelerators such as the Relativistic Heavy Ion Collider at BNL, or the Large Hadron Collider at CERN, Switzerland. These magnets are made of material that, cooled to 4 Kelvins (K) (-452° Farenheit) become superconducting, that is, lose essentially all resistance to electricity. For the past decade, however, Lab researchers have been exploring the use of new materials that become superconducting at higher temperatures. These materials can operate at the relatively high temperature of 77 K (-351°F), allowing them to be cooled by cheap, plentiful liquid nitrogen, rather than helium, and can create very high magnetic fields. Now far in the lead of this area of research, BNL scientists are exploring avenues for high temperature superconducting magnets that are energy efficient and have magnetic fields that are a million times stronger than the Earth’s. If successful, these new magnets could potentially revolutionize usage in future accelerators, play a key role in energy efficiency and storage, and make possible new applications such as muon colliders and MRI screening in remote areas.

  5. Applicability of Shape Memory Alloy Wire for an Active, Soft Orthotic

    Science.gov (United States)

    Stirling, Leia; Yu, Chih-Han; Miller, Jason; Hawkes, Elliot; Wood, Robert; Goldfield, Eugene; Nagpal, Radhika

    2011-07-01

    Current treatments for gait pathologies associated with neuromuscular disorders may employ a passive, rigid brace. While these provide certain benefits, they can also cause muscle atrophy. In this study, we examined NiTi shape memory alloy (SMA) wires that were annealed into springs to develop an active, soft orthotic (ASO) for the knee. Actively controlled SMA springs may provide variable assistances depending on factors such as when, during the gait cycle, the springs are activated; ongoing muscle activity level; and needs of the wearer. Unlike a passive brace, an active orthotic may provide individualized control, assisting the muscles so that they may be used more appropriately, and possibly leading to a re-education of the neuro-motor system and eventual independence from the orthotic system. A prototype was tested on a suspended, robotic leg to simulate the swing phase of a typical gait. The total deflection generated by the orthotic depended on the knee angle and the total number of actuators triggered, with a max deflection of 35°. While SMA wires have a high energy density, they require a significant amount of power. Furthermore, the loaded SMA spring response times were much longer than the natural frequency of an average gait for the power conditions tested. While the SMA wires are not appropriate for correction of gait pathologies as currently implemented, the ability to have a soft, actuated material could be appropriate for slower timescale applications.

  6. HTS Wire Development Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    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.

  7. Application of PTCA steerable guide wire for abdominal and peripheral interventional angiography

    Energy Technology Data Exchange (ETDEWEB)

    Kuribayashi, Sachio; Ootaki, Makoto; Iwata, Yoshirou; Harada, Tsumio; Tsuji, Makoto; Matsuyama, Seiya

    1988-06-01

    Steerable guide wire used in PTCA was applied for various abdominal and peripheral interventional angiographies in eight patients. In embolization procedures, this wire was used with coaxial catheter system. The steerable wire facilitated superselective catheterization of distal branches in mesenteric, renal and hepatic artery embolizations. This wire was also useful for traversing severe stenoses in renal and peripheral angioplasties.

  8. Superconducting homopolar motor and conductor development

    Science.gov (United States)

    Gubser, Donald U.

    1996-10-01

    The U.S. Navy has been developing superconducting homopolar motors for ship applications since 1969; a successful at-sea demonstration of the first motor, using NbTi wire for the magnet, was achieved in the early 1980s. Recently, this same motor was used as a test bed to demonstrate progress in high-critical-temperature superconducting magnet technology using bismuth-strontium- calcium-copper-oxide (BSCCO) compounds. In the fall of 1995, this motor achieved a performance of 124 kW operating at a temperature of 4.2 K and 91 kW while operating at 28 K. Future tests are scheduled using new magnets with conductors of both the 2223 and the 2212 BSCCO phases. This article describes the advantages of superconducting propulsion and recent progress in the development of BSCCO conductors for use in Navy power systems.

  9. Interplay of superconductivity and magnetism in Ba{sub 1-x}K{sub x}Fe{sub 2}As{sub 2} and ist potential as wire material

    Energy Technology Data Exchange (ETDEWEB)

    Wiesenmayer, Josef Erwin

    2015-07-07

    The results presented in this thesis provide a deeper insight in the physical properties of Ba{sub 1-x}K{sub x}Fe{sub 2}As{sub 2} and their connection among each other. By using a combination of high resolution X-ray diffraction, susceptibility measurements, and μSR, it was possible to unambiguously identify a microscopic coexistence of superconductivity and antiferromagnetism in underdoped Ba{sub 1-x}K{sub x}Fe{sub 2}As{sub 2} (up to x=0.23). This result strongly supports the assumption of an s± symmetry in the area 0f the phase diagram. These studies were extended to the optimally and overdoped Ba{sub 1-x}Na{sub x}Fe{sub 2}As{sub 2} up to x=0.66 generating a phase diagram displaying gradual transitions from long-range to short -range order instead of sharp borders. This magnetic order can be detected up to at last x=0.66, a value beyond the expected one (between 0.2 and 0.3). On Ba{sub 0.6}Na{sub 0.2}Fe{sub 2}As{sub 2} under pressure, a new antiferromagnetic order AFM2 was discovered, also displaying coexistence with superconductivity. In the second part of this thesis, Ba{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2} was examined as material for the production of superconducting wires and tapes. Preliminary critical current density measurements of these prototype filaments are encouraging. To further investigate these wires, a new synthesis route was explored using mechanical alloying of the ternary precursors BaFe{sub 2}As{sub 2} and KFe{sub 2}As{sub 2} in order to obtain larger sample amounts.

  10. Preparation o Y123 superconducting tape by organic acid salts; Yukisanen tofu netsubunkaiho ni yoru Y123 chodendo senzai no sakusei

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Y.; Hasegawa, T. [Showa Electric Wire and Cable Co., Ltd., Kanagawa (Japan)

    1999-11-10

    Critical current characteristics in the magnetic field is excellent in the Y system oxide superconducting wire rod, and it is expected as next generation wire rod, because the magnetic field dependence is good even in the liquid nitrogen temperature. We have carried out the examination of the Bi system superconductor tape wire rod by the applicator in respect of organic metal raw material on the metal tape state backing since the convention continue. This time, we newly made the octyl acid salt to be a raw material, and we examined the Y system superconductive film manufacture on the polycrystal Ag tape substrate. (NEDO)

  11. Realization of High-temperature Superconductivity in Nano-carbon Materials and Its Application

    Science.gov (United States)

    2015-07-13

    hottest topics in condensed matter physics and also for application to zero- emission energy system. In particular, carbon-based superconductors have...nano- carbon materials and its application II 5a. CONTRACT NUMBER FA2386-13-1-4059 5b. GRANT NUMBER Grant 13RSZ067_134059 5c. PROGRAM ELEMENT...for AOARD Grant F A2386-13- l-4059 "Realization of high-temperature superconductivity in nano-carbon materials and its application " Date: 07/13

  12. Principles and applications of superconducting quantum interference devices

    CERN Document Server

    1992-01-01

    Principles and applications of SQUIDs serves as a textbook and a multi-author collection of critical reviews. Providing both basic aspects and recent progress in SQUIDs technology, it offers a realistic and stimulating picture of the state of the art. It can also contribute to a further development of the field for commercial applications.

  13. Scientific Presentations on Superconductivity from 2002-2005

    Science.gov (United States)

    2006-01-01

    homopolar and synchronous superconducting motors to drive the US Navy’s future all-electric ship. HTS wire technology can be used in many of the system...components for these military applications such as motors , power generators, transformers, power converters/inductors, primary power cabling, and high...capability for the YBCO conductor leads to commercialization in electric power applications such as transformers, transmission cables, motors , fault

  14. 56th (fiscal 1997) Meeting on Cryogenics and Superconductivity; Dai 56 kai 1997 nendo shunki teion kogaku chodendo gakkai koen gaiyoshu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-14

    In the meeting, 266 papers were made public which deal with the following fields: GM refrigerators, pulse tube refrigerators, cold storage equipment, Bi-2212 system, coil application, superconducting generators, LHD/ITER/accelerators, cable-in conduit conductors, electromagnetic phenomena/proximity effect, oxide cable, Nb3Sn, Nb3Al, metal materials, WE-NET, friction/organic materials, composite materials, Nb3Sn, Nb3Al wires, strand wire structure analysis, hybrid superconducting wire, Y system, Bi system, low temperature device, measurement, high magnetic field NMR magnet, oxide NMR application, Bi-2223 system wire, pinning, NbTi ac wire, pinning/ac loss, various characteristics, superconducting application, refrigerating system, heat transfer, cryostat, Hg/Ti/Y system wire, ac loss/application, superconducting electric power storage system and the development of element technology therefor, current limiter/magnetic flotation, stability and drift of strand conductors, stability, ITER, LHD/accelerator/SLIM, oxide application, conductor stability test and others, and quench of ac cable.

  15. Potential Applications of Microtesla Magnetic Resonance ImagingDetected Using a Superconducting Quantum Interference Device

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Whittier Ryan [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    This dissertation describes magnetic resonance imaging (MRI) of protons performed in a precession field of 132 μT. In order to increase the signal-to-noise ratio (SNR), a pulsed 40-300 mT magnetic field prepolarizes the sample spins and an untuned second-order superconducting gradiometer coupled to a low transition temperature superconducting quantum interference device (SQUID) detects the subsequent 5.6-kHz spin precession. Imaging sequences including multiple echoes and partial Fourier reconstruction are developed. Calculating the SNR of prepolarized SQUID-detected MRI shows that three-dimensional Fourier imaging yields higher SNR than slice-selection imaging. An experimentally demonstrated field-cycling pulse sequence and post-processing algorithm mitigate image artifacts caused by concomitant gradients in low-field MRI. The magnetic field noise of SQUID untuned detection is compared to the noise of SQUID tuned detection, conventional Faraday detection, and the Nyquist noise generated by conducting biological samples. A second-generation microtesla MRI system employing a low-noise SQUID is constructed to increase SNR. A 2.4-m cubic, eddy-current shield with 6-mm thick aluminum walls encloses the experiment to attenuate external noise. The measured noise is 0.75 fT Hz-1/2 referred to the bottom gradiometer loop. Solenoids wound from 30-strand braided wire to decrease Nyquist noise and cooled by either liquid nitrogen or water polarize the spins. Copper wire coils wound on wooden supports produce the imaging magnetic fields and field gradients. Water phantom images with 0.8 x 0.8 x 10 mm3 resolution have a SNR of 6. Three-dimensional 1.6 x 1.9 x 14 mm3 images of bell peppers and 3 x 3 x 26 mm3 in vivo images of the human arm are presented. Since contrast based on the transverse spin relaxation rate (T1) is enhanced at low magnetic fields, microtesla MRI could potentially be used for tumor imaging. The

  16. Analysis of the trade-offs between conventional and superconducting interconnections

    Energy Technology Data Exchange (ETDEWEB)

    Frye, R.

    1989-05-01

    Superconductivity can now be achieved at temperatures compatible with semiconductor device operation. This raises the interesting possibility of using the new, high-temperature superconducting ceramics for interconnections in electronic systems. This paper examines some of the consequences of a resistance-free interconnection medium. A problem with conventional conductors in electronic systems is that the resistance of wires increases quadratically as the wire dimensions are scaled down. Below some minimum cross-sectional area, determined by the metal resistivity and wire length, the resistance in these lines begins to severely limit their bandwidth. Superconductors, on the other hand, are not constrained by the same scaling rules. They provide a high bandwidth interconnection at all sizes and lengths. The limitations for superconductors are set by their critical current densities. If line dimensions become too small, a superconductor will no longer support an adequate flow of current. An analysis is presented examining the performance trade-offs for conventional and superconducting interconnections in applications ranging from printed wiring boards to chips. For most semiconductor device-based applications, the potential gains in wiring density offered by superconductors are probably more important than the bandwidth improvements. An important result of the analysis is that it determines the values of critical current density above which superconductors outperform conventional wires in systems of various physical sizes. This identifies particular interconnection technologies for which high-temperature superconductors show the most promise.

  17. The Department of Defense Superconductivity Research and Development (DSRD) Options. A Study of Possible Directions for Exploitation of Superconductivity in Military Applications.

    Science.gov (United States)

    1987-07-01

    refrigeration systems. In one very elegant example, DoD funded development of a miniature refrigerator, for which the heat exchanger, expansion orifice...specific heat and magnetization, both as functions of temperature and magnetic field. Such investigations provide measures of superconducting state...small-scale (sensors and electronics) applications. 29 13 Thermnal and magnetocaloric effects. All sources of thermal input to both small-scale and large

  18. Conduction cooled high temperature superconducting dipole magnet for accelerator applications

    DEFF Research Database (Denmark)

    Zangenberg, N.; Nielsen, G.; Hauge, N.

    2012-01-01

    impregnated with epoxy and mounted between a support of stainless steel and a collar made from aluminum. The cold mass consisting of the coil assembly and a laminated steel yoke is cooled by two cryocoolers from via copper bars to below 20 K. Current leads were made from the same batch of HTS tape. Cryogen...... for accelerator applications in many fields, in particular where cryogenic liquid cooling is not an option....

  19. Superconducting bulk magnets for magnetic levitation systems

    Science.gov (United States)

    Fujimoto, H.; Kamijo, H.

    2000-06-01

    The major applications of high-temperature superconductors have mostly been confined to products in the form of wires and thin films. However, recent developments show that rare-earth REBa 2Cu 3O 7- x and light rare-earth LREBa 2Cu 3O 7- x superconductors prepared by melt processes have a high critical-current density at 77 K and high magnetic fields. These superconductors will promote the application of bulk high-temperature superconductors in high magnetic fields; the superconducting bulk magnet for the Maglev train is one possible application. We investigated the possibility of using bulk magnets in the Maglev system, and examined flux-trapping characteristics of multi-superconducting bulks arranged in array.

  20. Elastocaloric effect of Ni-Ti wire for application in a cooling device

    DEFF Research Database (Denmark)

    Tusek, Jaka; Engelbrecht, Kurt; Mikkelsen, Lars Pilgaard

    2015-01-01

    We report on the elastocaloric effect of a superelastic Ni-Ti wire to be used in a cooling device. Initially, each evaluated wire was subjected to 400 loading/unloading training cycles in order to stabilize its superelastic behavior. The wires were trained at different temperatures, which lead to...

  1. Magnetic-field-induced superconducting state in Zn nanowires driven in the normal state by an electric current.

    Science.gov (United States)

    Chen, Yu; Snyder, S D; Goldman, A M

    2009-09-18

    Four-terminal resistance measurements have been carried out on Zn nanowires formed using electron-beam lithography. When driven resistive by current, these wires reenter the superconducting state upon application of small magnetic fields. The data are qualitatively different from those of previous experiments on superconducting nanowires, which revealed either negative magnetoresistance near T_{c} or high-magnetic-field-enhanced critical currents.

  2. High Temperature Superconductivity in the Past Twenty Years Part 2-Towards to Practical Applications

    Institute of Scientific and Technical Information of China (English)

    Jian-Xun Jin

    2008-01-01

    After discovering high temperature super- conducting materials 20 years ago, the preparation of applicable HTS materials has been pursued along with HTS mechanism and characteristic study. At present, the focus on the applied HTS technology has been moving to the industrial preparations from the laboratory research stage, and the technology has been well verified for practical applications from small to large scales. The fabrication techniques of engineering HTS materials are being industrialized; and various HTS devices are also on the way towards practical applications. This paper provides a comprehensive summary on the applied high temperature superconductivity with regard to various applicable HTS materials, their preparation techniques and charac- terization, and applications in a wide range.

  3. FLYWHEEL ENERGY STORAGE SYSTEMS WITH SUPERCONDUCTING BEARINGS FOR UTILITY APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Michael Strasik; Mr. Arthur Day; Mr. Philip Johnson; Dr. John Hull

    2007-10-26

    This project’s mission was to achieve significant advances in the practical application of bulk high-temperature superconductor (HTS) materials to energy-storage systems. The ultimate product was planned as an operational prototype of a flywheel system on an HTS suspension. While the final prototype flywheel did not complete the final offsite demonstration phase of the program, invaluable lessons learned were captured on the laboratory demonstration units that will lead to the successful deployment of a future HTS-stabilized, composite-flywheel energy-storage system (FESS).

  4. Applications using high-Tc superconducting terahertz emitters

    Science.gov (United States)

    Nakade, Kurama; Kashiwagi, Takanari; Saiwai, Yoshihiko; Minami, Hidetoshi; Yamamoto, Takashi; Klemm, Richard A.; Kadowaki, Kazuo

    2016-03-01

    Using recently-developed THz emitters constructed from single crystals of the high-Tc superconductor Bi2Sr2CaCu2O8+δ, we performed three prototype tests of the devices to demonstrate their unique characteristic properties for various practical applications. The first is a compact and simple transmission type of THz imaging system using a Stirling cryocooler. The second is a high-resolution Michelson interferometer used as a phase-sensitive reflection-type imaging system. The third is a system with precise temperature control to measure the liquid absorption coefficient. The detailed characteristics of these systems are discussed.

  5. Strain control of composite superconductors to prevent degradation of superconducting magnets due to a quench: I. Ag/Bi2Sr2CaCu2Ox multifilament round wires

    Science.gov (United States)

    Ye, Liyang; Li, Pei; Jaroszynski, Jan; Schwartz, Justin; Shen, Tengming

    2017-02-01

    The critical current of many practical superconductors is sensitive to strain, and this sensitivity is exacerbated during a quench that induces a peak local strain which can be fatal to superconducting magnets. Here, a new method is introduced to quantify the influence of the conductor stress and strain state during normal operation on the margin to degradation during a quench, as measured by the maximum allowable hot spot temperature T allowable, for composite wires within superconducting magnets. The first conductor examined is Ag-sheathed Bi2Sr2CaCu2Ox round wire carrying high engineering critical current density, J E, of 550 A mm-2 at 4.2 K and 15 T. The critical axial tensile stress of this conductor is determined to be 150 MPa and, in the absence of Lorentz forces, T allowable is greater than 450 K. With increasing axial tensile stress, σ a, however, T allowable decreases nonlinearly, dropping to 280 K for σ a = 120 MPa and to 160 K for σ a = 145 MPa. T allowable(σ a) is shown to be nonlinear and independent of magnetic field from 15 to 30 T. T allowable(σ a) dictates the balance between magnetic field generation, which increases with the magnet operating current and stress, and the safety margin, which decreases with decreasing T allowable, and therefore has important engineering value. It is also shown that T allowable(σ a) can be predicted accurately by a general strain model, showing that strain control is the key to preventing degradation of superconductors during a quench.

  6. Cryogenic Fiber Optic Sensors for Superconducting Magnets and Power Transmission Lines in High Energy Physics Applications

    CERN Document Server

    AUTHOR|(CDS)2081689; Bajko, Marta

    In the framework of the Luminosity upgrade of the Large Hadron Collider (HL - LHC), a remarkable R&D effort is now ongoing at the European Organization for Nuclear Research (CERN) in order to develop a new generation of accelerator magnets and superconducting power transmission lines. The magnet technology will be based on Nb3Sn enabling to operate in the 11 - 13 T range. In parallel, in order to preserve the power converters from the increasing radiation level, high power transmission lines are foreseen to feed the magnets from free - radiation zones. These will be based on high temperature superconductors cooled down with helium gas in the range 5 - 30 K. The new technologies will require advanced design and fabrication approaches as well as adapted instrumentation for monitoring both the R&D phase and operation. Resistive sensors have been used so far for voltage, temperature and strain monitoring but their integration still suffers from the number of electrical wires and the complex compensation o...

  7. Development of superconducting transmission cable. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

    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.

  8. Investigation of inter-grain critical current density in Bi2Sr2CaCu2O8+δ superconducting wires and its relationship with the heat treatment protocol

    Science.gov (United States)

    Pallecchi, I.; Leveratto, A.; Braccini, V.; Zunino, V.; Malagoli, A.

    2017-09-01

    In this work we investigate the effect of each different heat treatment stage in the fabrication of Bi2Sr2CaCu2O8+δ superconducting wires on intra-grain and inter-grain superconducting properties. We measure magnetic critical temperature T c values and transport critical current density J c at temperatures from 4 K to 40 K and in fields up to 7 T. From an analysis of the temperature dependence of the self-field critical current density J c(T) that takes into account weak link behavior and the proximity effect, we study grain boundary (GB) transparency to supercurrents; we also establish a relationship between GB oxygenation in the different steps of the fabrication process and GB transparency to supercurrents. We find that GB oxygenation starts in the first crystallization stage, but it becomes complete in the plateau at 836 °C and in slow cooling stages and is further enhanced in the prolonged post-annealing step. Such oxygenation makes GBs more conductive, thus improving the inter-grain J c value and temperature dependence. On the other hand, from inspection of the T c values in the framework of the phase diagram dome, we find that grains are already oxygenated in the crystallization step up to the optimal doping, while successive slow cooling and post-annealing treatments further enhance the degree of overdoping, especially if carried out in oxygen atmosphere rather than in air.

  9. Cryogenic deformation of high temperature superconductive composite structures

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-01-01

    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.

  10. Materials Pushing the Application Limits of Wire Grid Polarizers further into the Deep Ultraviolet Spectral Range

    CERN Document Server

    Siefke, Thomas; Pfeiffer, Kristin; Puffky, Oliver; Dietrich, Kay; Franta, Daniel; Ohlídal, Ivan; Szeghalmi, Adriana; Kley, Ernst-Bernhard; Tünnermann, Andreas

    2016-01-01

    Wire grid polarizers (WGPs), periodic nano-optical meta-surfaces, are convenient polarizing elements for many optical applications. However, they are still inadequate in the deep ultraviolet spectral range. We show that to achieve high performance ultraviolet WGPs a material with large absolute value of the complex permittivity and extinction coefficient at the wavelength of interest has to be utilized. This requirement is compared to refractive index models considering intraband and interband absorption processes. We elucidate why the extinction ratio of metallic WGPs intrinsically humble in the deep ultraviolet, whereas wide bandgap semiconductors are superior material candidates in this spectral range. To demonstrate this, we present the design, fabrication and optical characterization of a titanium dioxide WGP. At a wavelength of 193 nm an unprecedented extinction ratio of 384 and a transmittance of 10 % is achieved.

  11. Tuning the Superconducting Properties of Magnesium Diboride

    Energy Technology Data Exchange (ETDEWEB)

    Theoderich Wilke, Rudeger Heinrich [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    This work is presented in the following order: A review of the relevant physics and discussion of theoretical predictions for a two gap superconducting compound is given in chapter 2. Chapter 3 provides a review of the basic properties of MgB2. Details of sample synthesis and characterization are given in chapter 4. Chapter 5 presents normal state and superconducting properties of Mg(B1-xCx)2 wires. Attempts to increase critical current densities in filaments via titanium additions are discussed in chapter 6. In chapters 7 and 8 alternative methods for synthesizing doped MgB2 powders are explored. In chapter 7 we synthesize Mg(B1-xCx)2 up to x=0.069 using a mixture of Mg, B, and the binary compound B4C. Chapter 8 explores an alternative method, plasma spray synthesis, to produce nanometer sized doped boron powders for powder-in-tube applications. The effects of neutron irradiation on pure MgB2 wires is discussed in chapter 9. This is followed by a study of the effects of neutron irradiation on Mg(B.962C.038)2 wires, presented in chapter 10. I will summarize the results of all of these studies in chapter 11 and discuss future directions for research in understanding the physics behind this novel material as well as its development for practical applications. In this thesis I have presented the results of investigations into the changes in the superconducting properties of MgB2 as a function of carbon doping and neutron irradiation. The goal has been to understand the physics underlying this unique two-gap superconductor as different types of perturbations are made to the system. Such knowledge not only contributes to our understanding of two-gap superconductivity, but could potentially lead to the development of superconducting MgB2 wires for the use in power applications near 20 K.

  12. Superconducting Microelectronics.

    Science.gov (United States)

    Henry, Richard W.

    1984-01-01

    Discusses superconducting microelectronics based on the Josephson effect and its advantages over conventional integrated circuits in speed and sensitivity. Considers present uses in standards laboratories (voltage) and in measuring weak magnetic fields. Also considers future applications in superfast computer circuitry using Superconducting…

  13. On the development of a heuristic routing application for the automatic wire harness design in the aircraft

    NARCIS (Netherlands)

    Zhu, Z.; Van Tooren, M.J.L.; Van der Elst, S.W.G.

    2011-01-01

    Based on the use of dedicated software tools, Knowledge Based Engineering (KBE) techniques are able to capture and reuse engineering product and process knowledge to reduce time and cost during product development. In this paper a conceptual design of an automatic wire harness routing application is

  14. H2-norm for mesh optimization with application to electro-thermal modeling of an electric wire in automotive context

    Science.gov (United States)

    Chevrié, Mathieu; Farges, Christophe; Sabatier, Jocelyn; Guillemard, Franck; Pradere, Laetitia

    2017-04-01

    In automotive application field, reducing electric conductors dimensions is significant to decrease the embedded mass and the manufacturing costs. It is thus essential to develop tools to optimize the wire diameter according to thermal constraints and protection algorithms to maintain a high level of safety. In order to develop such tools and algorithms, accurate electro-thermal models of electric wires are required. However, thermal equation solutions lead to implicit fractional transfer functions involving an exponential that cannot be embedded in a car calculator. This paper thus proposes an integer order transfer function approximation methodology based on a spatial discretization for this class of fractional transfer functions. Moreover, the H2-norm is used to minimize approximation error. Accuracy of the proposed approach is confirmed with measured data on a 1.5 mm2 wire implemented in a dedicated test bench.

  15. Method of manufacturing superconductor wire

    Science.gov (United States)

    Motowidlo, Leszek

    2014-09-16

    A method for forming Nb.sub.3Sn superconducting wire is provided. The method employs a powder-in-tube process using a high-tin intermetallic compound, such as MnSn.sub.2, for producing the Nb.sub.3Sn. The use of a high-tin intermetallic compound enables the process to perform hot extrusion without melting the high-tin intermetallic compound. Alternatively, the method may entail drawing the wire without hot extrusion.

  16. Industrialization of Hot Wire Chemical Vapor Deposition for thin film applications

    Energy Technology Data Exchange (ETDEWEB)

    Schropp, R.E.I., E-mail: r.e.i.schropp@tue.nl

    2015-11-30

    The consequences of implementing a Hot Wire Chemical Vapor Deposition (HWCVD) chamber into an existing in-line or roll-to-roll reactor are described. The hardware and operation of the HWCVD production reactor is compared to that of existing roll-to-roll reactors based on Plasma Enhanced Chemical Vapor Deposition. The most important consequences are the technical consequences and the economic consequences, which are both discussed. The technical consequences are adaptations needed to the hardware and to the processing sequences due to the different interaction of the HWCVD process with the substrate and already deposited layers. The economic consequences are the reduced investments in radio frequency (RF) supplies and RF components. This is partially offset by investments that have to be made in higher capacity pumping systems. The most mature applications of HWCVD are moisture barrier coatings for thin film flexible devices such as Organic Light Emitting Diodes and Organic Photovoltaics, and passivation layers for multicrystalline Si solar cells, high mobility field effect transistors, and silicon heterojunction cells (also known as heterojunction cells with intrinsic thin film layers). Another example is the use of Si in thin film photovoltaics. The cost perspective per unit of thin film photovoltaic product using HWCVD is estimated at 0.07 €/Wp for the Si thin film component. - Highlights: • Review of consequences of implementing Hot Wire CVD into a manufacturing plant • Aspects of scaling up to large area and continuous manufacturing are discussed • Economic advantage of introducing a HWCVD process in a production system is estimated • Using HWCVD, the cost for the Si layers in photovoltaic products is 0.08 €/Wp.

  17. Wire-grid electromagnetic modelling of metallic cylindrical objects with arbitrary section, for Ground Penetrating Radar applications

    Science.gov (United States)

    Adabi, Saba; Pajewski, Lara

    2014-05-01

    Authors demonstrated that the well-known same-area criterion yields affordable results but is quite far from being the optimum: better results can be obtained with a wire radius shorter than what is suggested by the rule. In utility detection, quality controls of reinforced concrete, and other civil-engineering applications, many sought targets are long and thin: in these cases, two-dimensional scattering methods can be employed for the electromagnetic modelling of scenarios. In the present work, the freeware tool GPRMAX2D [6], implementing the Finite-Difference Time-Domain method, is used to implement the wire-grid modelling of buried two-dimensional objects. The source is a line of current, with Ricker waveform. Results obtained in [5] are confirmed in the time domain and for different geometries. The highest accuracy is obtained by shortening the radius of about 10%. It seems that fewer (and larger) wires need minor shortening; however, more detailed investigations are required. We suggest to use at least 8 - 10 wires per wavelength if the field scattered by the structure has to be evaluated. The internal field is much more sensitive to the modelling configuration than the external one, and more wires should be employed when shielding effects are concerned. We plan to conduct a more comprehensive analysis, in order to extract guidelines for wire sizing, to be validated on different shapes. We also look forward to verifying the possibility of using the wire-grid modelling method for the simulation of slotted objects. This work is a contribution to COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar". The Authors thanks COST for funding COST Action TU1208. References [1] J.H. Richmond, A wire grid model for scattering by conducting bodies, IEEE Trans. Antennas Propagation AP-14 (1966), pp. 782-786. [2] S.M. Rao, D.R. Wilton, A.W. Glisson, Electromagnetic scattering by surfaces of arbitrary shape, IEEE Trans. Antennas Propagation AP-30 (1982

  18. The Study about Application of Transportation System of the Superconductive Electromagnetism Propulsion in the Harbor

    OpenAIRE

    涌井, 和也; 荻原, 宏康

    1999-01-01

    Electromagnetic propulsion is promising technique for a linear motor car, a ship and a space ship, in future. W. A Rice developed an electromagnetic pump for the liquid metal transfer. There are two electromagnetic propulsions : a superconductive electricity propulsion and a superconductive electromagnetic propulsion. A superconductive electricity propulsion ship uses a screw driven by a superconducting motor. This technique has merits of excellent navigation-ability, and the free degree of t...

  19. Magnetic Field Reentrant Superconductivity in Aluminum Nanowires

    Science.gov (United States)

    Bretz-Sullivan, Terence; Goldman, Allen

    Reentrance to the superconducting state through the application of a magnetic field to quasi-one dimensional superconductors driven resistive by current, is counter to the expected properties of superconductors. It was not until recently that a microscopic mechanism explaining the phenomenon was proposed in which superconductivity and phase slip driven dissipation coexist in a non-equilibrium state. Here we present additional results of magnetic field induced reentrance into the superconducting state in quasi-one-dimensional aluminum nanowires with an in-plane magnetic field both transverse to, and along the wire axis. The reentrant behavior is seen in the magnetic field dependence of the I-V characteristic and resistance vs. temperature, and in the wire's magnetoresistance at 450mK. This work was supported by DOE Basic Energy Sciences Grant DE-FG02-02ER46004. Samples were fabricated at the Minnesota Nanofabrication Center. Parts of this work were carried out in the University of Minnesota Characterization Facility, a member of the Materials Research Facilities Network (www.mrfn.org) funded via the NSF MRSEC program.

  20. Phase slips in superconducting weak links

    Energy Technology Data Exchange (ETDEWEB)

    Kimmel, Gregory; Glatz, Andreas; Aranson, Igor S.

    2017-01-01

    Superconducting vortices and phase slips are primary mechanisms of dissipation in superconducting, superfluid, and cold-atom systems. While the dynamics of vortices is fairly well described, phase slips occurring in quasi-one- dimensional superconducting wires still elude understanding. The main reason is that phase slips are strongly nonlinear time-dependent phenomena that cannot be cast in terms of small perturbations of the superconducting state. Here we study phase slips occurring in superconducting weak links. Thanks to partial suppression of superconductivity in weak links, we employ a weakly nonlinear approximation for dynamic phase slips. This approximation is not valid for homogeneous superconducting wires and slabs. Using the numerical solution of the time-dependent Ginzburg-Landau equation and bifurcation analysis of stationary solutions, we show that the onset of phase slips occurs via an infinite period bifurcation, which is manifested in a specific voltage-current dependence. Our analytical results are in good agreement with simulations.

  1. 7 CFR 1755.704 - Requirements applicable to both CCSR and NMR aerial service wires.

    Science.gov (United States)

    2010-01-01

    ... of the manufacturer to produce wire products having long life and stability. (2) For initial...; (ii) Performance of the conductor insulation and jacket material; (iii) Sequential marking and... §§ 1755.700 through 1755.704. (2) Repairs to the jacket of NMR aerial service wires are not permitted in...

  2. New source of colour coded signal wire sleeving for cryogenic applications

    Science.gov (United States)

    Putnam, A. M.

    Wire sleeving made from Pb core nylon fishing line is presented. Signal wires can easily be sheathed in the nylon outer of weighted trolling line by drawing them through the outer attached to the core. Such line comes with a selection of colours on a single spool.

  3. Application of the Wire Bonding Technology to a Flexible Neural Probe

    Science.gov (United States)

    Shimizu, Koichi; Nakanishi, Motofumi; Makikawa, Masaaki; Asajima, Syuzo; Konishi, Satoshi

    This paper proposes a novel neural probe using flexible metal wire for wire bonding on LSI chip. Wire bonding technology can provide a number of flexible wire arrays. The proposed neural probe is used for a nerve interface for functional electric stimulation (FES) technology which assists the paralysis of living body function by a spinal cord injury. The flexibility of probe will provide low invasive and safe neural interfaces for the nerve tissue from a long term view. We employ a combination of wire bonding and laser machining for the fabrication of aligned flexible probes. Aligned bonded flexible metal wires on electrodes are converted to probe arrays by cutting the bridge between electrodes. Typical dimension of a bonding wire is several tens μm in diameter and is suitable for neural probe to be inserted into nerve bundles. Needle shape is formed by electro-polishing of cut edge. Proposed method can be benefited by advantages of wire bonding as the widespread technology in electronics industry. Developed flexible neural probe based on the proposed technology is estimated as a nerve interface by inserting to a sciatic nerve of a rat.

  4. New Insulation Constructions for Aerospace Wiring Applications. Volume 1. Testing and Evaluation

    Science.gov (United States)

    1991-06-01

    the maintenance environment where cut through damage is most likely to occur, 70"C and 150"C represent realistic high tnuiepzatuz’w deta points and...in the adherence of the tape on any of the wire types. D. PEG AND BUNDLE - It was noted that the "I Type" wire had too much memory, thus, creating

  5. The application of pneumatic jigging in the recovery of metallic fraction from shredded printed wiring boards.

    Science.gov (United States)

    Wang, Zheng; Hall, Philip; Miles, Nicholas J; Wu, Tao; Lambert, Peter; Gu, Fu

    2015-09-01

    Waste electrical and electronic equipment (WEEE) is one of the fastest growing waste streams worldwide with volumes increasing by 40% each year. WEEE has attracted increasing concern worldwide due to its high metal content and the potential environmental threat which results from uncontrolled recycling practices. Innovative physical separation techniques for WEEE recycling are preferential compared with chemical methods because of the reduction of energy and chemical consumption as well as potential environmental threats. Pneumatic jigging is a dry separation process capable of achieving good separation of coarse material within a very narrow density range, which makes it suitable as a pretreatment process for WEEE recycling. The work presented in this paper investigates the potential application of pneumatic jigging in metal recovery from WEEE. A pilot scale pneumatic jig has been developed by University of Nottingham Ningbo to separate shredded printed wiring boards into two streams: a light fraction (mainly non-metallic fraction consisting of glass fiber, fluffs, and plastic pieces) and dense fraction (metallic fraction). The novelty of work presented in this paper is the application of a dry separation technique in WEEE recycling for metal recovery. Compared with conventional wet separation processes involved in WEEE recycling industry, dry separation has the advantage of zero secondary pollution. The results of this experimental program show pneumatic jigging to be an effective and environmental friendly technique as a pretreatment process for the recovery of the metallic fraction from shredded WEEE. © The Author(s) 2015.

  6. Application of textured YBCO bulks with artificial holes for superconducting magnetic bearing

    Science.gov (United States)

    Dias, D. H. N.; Sotelo, G. G.; Moysés, L. A.; Telles, L. G. T.; Bernstein, P.; Kenfaui, D.; Aburas, M.; Chaud, X.; Noudem, J. G.

    2015-07-01

    The levitation force between a superconductor and a permanent magnet has been investigated for the development of superconducting magnetic bearings (SMBs). Depending on the proposed application, the SMBs can be arranged with two kinds of symmetries: rotational or linear. The SMBs present passive operation, low level of noise and no friction, but they need a cooling system for their operation. Nowadays the cooling problem may be easily solved by the use of a commercial cryocooler. The levitation force of SMBs is directly related to the quality of the superconductor material (which depends on its critical current density) and the permanent magnet arrangement. Also, research about the YBa2Cu3Ox (Y123) bulk materials has shown that artificial holes enhance the superconducting properties, in particular the magnetic trapped field. In this context, this work proposes the investigation of the levitation force of a bulk Y123 sample with multiple holes and the comparison of its performances with those of conventional plain Y123 superconductors.

  7. Application of superconducting technologies as chemical/biological agent electronic eyes

    Science.gov (United States)

    Savoy, Steven M.; Eames, Sara J.; Jurbergs, David C.; Zhao, Jianai; McDevitt, John T.; Sobel, Annette L.

    1997-01-01

    High temperature superconductors provide enhanced sensitivity capabilities as chemical/biological agent detectors. State-of-the-art advances in ruggedizing superconducting platforms make them much more robust for field applications. In addition, microminiaturization and advances in refrigeration have enabled the systems engineering of portable, durable, survivable, low power requirement devices. This presentation describes a prototype system employing YBCO (yttrium barium copper oxide) superconducting quantum interference devices (SQUIDS) with specific biolayer detection dye coatings. These devices may be deployed as specific stand-off detectors, or potentially reconfigured as point sensors. A library of pattern recognition algorithms provides the reference template for the system. The human-system interface will provide a 'yes/no' agent confirmation for the environment being queried, and associated confidence value. This prototype detection system has great potential for deployment in support of hostage rescue/rapid response teams, DMAT, and urban search and rescue. The preparation and characterization of a new generation of optical sensors fabricated from high-temperature superconductor (HTSC) thin films is reported herein. These new hybrid devices are fashioned using HTSC thin films which are coated with organic dye overlayers. These systems are shown to respond selectively to those wavelengths which are absorbed strongly by the molecular dye. Methods for fabricating the superconductor element and depositing the dye layer are discussed. Moreover, resistivity versus temperature measurements before and after dye deposition are utilized to characterize these hybrid structures. The unique optical response properties of these hybrid sensors are also detailed.

  8. The role of superconductivity in magnetic bearings for high-load applications

    Science.gov (United States)

    Downer, James; Eisenhaure, David

    1993-01-01

    Slewing of large payloads will require control torque and angular momentum storage capacities that are large in comparison to the capabilities of available control moment gyros (CMG's). SatCon Technology Corporation is currently designing a CMG which may be employed as a slew actuator for large spacecraft or other payloads. The slew actuator employs a type of magnetic bearing which may be used in high load applications. The magnetic bearing is also used to fully gimbal the suspended rotor of the slew actuator. The use of magnetic bearings in angular momentum exchange actuators has the primary advantage that physical contact between the rotor and stator is eliminated. This leads to greatly extended life, increased reliability, and reduced vibrations. Several actuators operating on magnetic bearings have been demonstrated in previous research efforts. These were sized for use in small satellites. For conventional magnetic bearings, which employ magnetic cores, high torsional loading may require that the magnetic structure be excessively massive. An alternative magnetic bearing design which employs a superconducting coil and eliminates conventional magnetic structures is discussed. The baseline approach is to replace the field coil of a conventional magnetic bearing with the superconducting coil.

  9. Characteristics and Application of New Varieties of Copper Clad Aluminum Wire and Copper Clad Steel Wire%铜包铝线和铜包钢线新品种的特性及应用

    Institute of Scientific and Technical Information of China (English)

    王洪丽

    2013-01-01

    The characteristics,applications,product standards,and application technology of the secondarily developed new varieties of copper clad aluminum wire and copper clad steel wire are introduced,including copper clad aluminum enameled wire,tinned copper clad aluminum wire,tinned copper clad steel wire,silver plated copper clad steel wire,so as to provide cable manufacturers and electronic components manufacturers with better choices for cable and electronic materials.%介绍了铜包铝线和铜包钢线二次开发的新品种线材(包括铜包铝漆包线、镀锡铜包铝线、镀锡铜包钢线、镀银铜包钢线)的特性及其应用领域、产品标准和应用技术,以期为线缆厂家及电子元器件厂家提供更好的线缆材料和电子材料的选择.

  10. Cold wire constant voltage anemometry to measure temperature fluctuations and its application in a thermoacoustic system

    Science.gov (United States)

    Cleve, Sarah; Jondeau, Emmanuel; Blanc-Benon, Philippe; Comte-Bellot, Geneviève

    2017-04-01

    The knowledge of temperature fluctuations is essential for most thermoacoustic systems. In the present paper, cold wire constant-voltage anemometry (CVA) to measure temperature fluctuations is presented. Corrections for the thermal inertia and for the end losses of the wire are applied during the post-processing. The correction for the thermal inertia of the cold wire is achieved by applying a time dependent thermal lag as proposed originally for a constant-current anemometry (CCA) system. This thermal lag is measured in parallel by a hot wire. The thermal end losses of the wires to their supports are also considered and approximate corrections are proposed. The procedure for the cold wire CVA is validated in the acoustic field of an acoustic resonator with wires of different lengths. A comparison between a CVA and a CCA measurement also confirms the CVA measurement. Furthermore, the proposed measurement procedure is applied close to the stack of a thermoacoustic refrigerator. Supposing a two-dimensional flow, the simultaneous measurement of velocity and temperature fluctuations is possible. This allows a detailed examination of the acoustic field close to the stack, including the study of the correlation between temperature and velocity.

  11. Application of the hot-wire anemometer to respiratory measurements in small animal.

    Science.gov (United States)

    Godal, A; Belenky, D A; Standaert, T A; Woodrum, D E; Grimsrud, L; Hodson, W A

    1976-02-01

    A hot-wire anemometer was evaluated to determine its suitability for measurement of small tidal volumes. Used with a constant background flow of gas, the output of the hot-wire anemometer was linear and independent of respiratory frequency, temperature, and humidity. The change in output with CO2 concentration was negligible within the physiologic range. The use of a background flow eliminates the need for one-way valves, minimizes dead space, and maintains the flow velocity past the hot wire within its range of linear response.

  12. Superconducting quantum interference device microsusceptometer balanced over a wide bandwidth for nuclear magnetic resonance applications

    Energy Technology Data Exchange (ETDEWEB)

    Vinante, A., E-mail: anvinante@fbk.eu; Falferi, P. [Istituto di Fotonica e Nanotecnologie, CNR - Fondazione Bruno Kessler, I-38123 Povo, Trento (Italy); Mezzena, R. [Dipartimento di Fisica, Università di Trento, I-38123 Povo, Trento (Italy)

    2014-10-15

    Superconducting Quantum Interference Device (SQUID) microsusceptometers have been widely used to study magnetic properties of materials at microscale. As intrinsically balanced devices, they could also be exploited for direct SQUID-detection of nuclear magnetic resonance (NMR) from micron sized samples, or for SQUID readout of mechanically detected NMR from submicron sized samples. Here, we demonstrate a double balancing technique that enables achievement of very low residual imbalance of a SQUID microsusceptometer over a wide bandwidth. In particular, we can generate ac magnetic fields within the SQUID loop as large as 1 mT, for frequencies ranging from dc up to a few MHz. As an application, we demonstrate direct detection of NMR from {sup 1}H spins in a glycerol droplet placed directly on top of the 20 μm SQUID loops.

  13. Study of the {delta}-Al/Ag superconducting alloy for TES applications

    Energy Technology Data Exchange (ETDEWEB)

    Gastaldo, L. [Department of Physics, University and INFN of Genoa, Via Dodecaneso 33, 16146 Genoa (Italy) and Kirchhoff-Institut fuer Physik, Universitaet Heidelberg, INF 227, 69120 Heidelberg (Germany) and Technische Universitat Munchen, E15 James Franck Strasse, D-85748 Garching (Germany)]. E-mail: loredana.gastaldo@ge.infn.it; Gallinaro, G. [Department of Physics, University and INFN of Genoa, Via Dodecaneso 33, 16146 Genoa (Italy); Gatti, F. [Department of Physics, University and INFN of Genoa, Via Dodecaneso 33, 16146 Genoa (Italy); Pergolesi, D. [Department of Physics, University and INFN of Genoa, Via Dodecaneso 33, 16146 Genoa (Italy); Gomes, M. Ribeiro [Department of Physics, University and INFN of Genoa, Via Dodecaneso 33, 16146 Genoa (Italy); Repetto, P. [Department of Physics, University and INFN of Genoa, Via Dodecaneso 33, 16146 Genoa (Italy); Dussoni, S. [Department of Physics, University and INFN of Genoa, Via Dodecaneso 33, 16146 Genoa (Italy); Valle, R. [Department of Physics, University and INFN of Genoa, Via Dodecaneso 33, 16146 Genoa (Italy); Manfrinetti, P. [INFM and Dipartimento di Chimica e Chimica Industriale via Dodecaneso 33, 16146 Genova (Italy); Chincarini, A. [Department of Physics, University and INFN of Genoa, Via Dodecaneso 33, 16146 Genoa (Italy)

    2006-04-15

    Despite the general discard in using Al/Ag alloys as transition edge sensors (TES), primarily due to the persistent instability of these devices, further investigations were conducted on the metallic diffusion processes based on the phase diagram of these systems for periods of more than 9 months. The results demonstrated the formation of a stable superconducting inter-metallic alloy at the sample interface showing an HCP lattice corresponding to the {delta}-Al/Ag phase alloy. Furthermore, the transition temperature of the alloy depends on the material stoichoimetry and can vary from about 80 mK to more than 100 mK. In this paper, we suggest the R and D continuation of Al/Ag inter-metallic {delta}-phase as homogeneous stable films for TES applications.

  14. Superconducting magnetic quadrupole

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.W.; Shepard, K.W.; Nolen, J.A.

    1995-08-01

    A design was developed for a 350 T/m, 2.6-cm clear aperture superconducting quadrupole focussing element for use in a very low q/m superconducting linac as discussed below. The quadrupole incorporates holmium pole tips, and a rectangular-section winding using standard commercially-available Nb-Ti wire. The magnet was modeled numerically using both 2D and 3D codes, as a basis for numerical ray tracing using the quadrupole as a linac element. Components for a prototype singlet are being procured during FY 1995.

  15. Application of Feedforward and Feedback Control Strategy for Wire Rod Hot Rolling Line

    Institute of Scientific and Technical Information of China (English)

    ZHU Hong-xiang; HAO Xiao-hong; WEN Zhi; HU Ze-qiang; ZHANG Yao-gen; CHEN Hu-qiu

    2005-01-01

    The feedforward and feedback control strategy of water flowrate based on the analysis of thermal process in water cooling box was proposed, and the control strategy was applied to wire rod hot rolling at Baosteel Co.The operation has proved that the strategy can control water flowrate in the cooling water box reasonably to ensure the temperature requirement of the wire discharged from the cooling water box.

  16. Design and market considerations for axial flux superconducting electric machine design

    Science.gov (United States)

    Ainslie, M. D.; George, A.; Shaw, R.; Dawson, L.; Winfield, A.; Steketee, M.; Stockley, S.

    2014-05-01

    In this paper, the authors investigate a number of design and market considerations for an axial flux superconducting electric machine design that uses high temperature superconductors. The axial flux machine design is assumed to utilise high temperature superconductors in both wire (stator winding) and bulk (rotor field) forms, to operate over a temperature range of 65-77 K, and to have a power output in the range from 10s of kW up to 1 MW (typical for axial flux machines), with approximately 2-3 T as the peak trapped field in the bulk superconductors. The authors firstly investigate the applicability of this type of machine as a generator in small- and medium-sized wind turbines, including the current and forecasted market and pricing for conventional turbines. Next, a study is also carried out on the machine's applicability as an in-wheel hub motor for electric vehicles. Some recommendations for future applications are made based on the outcome of these two studies. Finally, the cost of YBCO-based superconducting (2G HTS) wire is analysed with respect to competing wire technologies and compared with current conventional material costs and current wire costs for both 1G and 2G HTS are still too great to be economically feasible for such superconducting devices.

  17. Superconducting energy recovery linacs

    Science.gov (United States)

    Ben-Zvi, Ilan

    2016-10-01

    High-average-power and high-brightness electron beams from a combination of laser photocathode electron guns and a superconducting energy recovery linac (ERL) is an emerging accelerator science with applications in ERL light sources, high repetition rate free electron lasers , electron cooling, electron ion colliders and more. This paper reviews the accelerator physics issues of superconducting ERLs, discusses major subsystems and provides a few examples of superconducting ERLs.

  18. High-Temperature Superconductivity

    Science.gov (United States)

    Tanaka, Shoji

    2006-12-01

    A general review on high-temperature superconductivity was made. After prehistoric view and the process of discovery were stated, the special features of high-temperature superconductors were explained from the materials side and the physical properties side. The present status on applications of high-temperature superconductors were explained on superconducting tapes, electric power cables, magnets for maglev trains, electric motors, superconducting quantum interference device (SQUID) and single flux quantum (SFQ) devices and circuits.

  19. Application of Hot-wire Method for Measuring Thermal Conductivity of Fine Ceramics

    Directory of Open Access Journals (Sweden)

    Shangxi WANG

    2016-11-01

    Full Text Available Ceramic substrate is preferred in high density packaging due to its high electrical resistivity and moderate expansion coefficient. The thermal conductivity is a key parameter for packaging substrates. There are two common methods to measure the thermal conductivity, which are the hot-wire method and the laser-flash method. Usually, the thermal conductivities of porcelain is low and meet the measurement range of hot-wire method, and the measured value by hot-wire method has little difference with that by laser-flash method. In recent years, with the requirement of high-powered LED lighting, some kinds of ceramic substrates with good thermal conductivity have been developed and their thermal conductivity always measured by the means of laser flash method, which needs expensive instrument. In this paper, in order to detect the thermal conductivity of fine ceramic with convenience and low cost, the feasibility of replacing the laser flash method with hot wire method to measure thermal conductivity of ceramic composites was studied. The experiment results showed that the thermal conductivity value of fine ceramics measured by the hot-wire method is severely lower than that by the laser-flash method. However, there is a positive relationship between them. It is possible to measure the thermal conductivity of fine ceramic workpiece instantly by hot-wire method via a correction formula.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12543

  20. FINE-FILAMENT MAGNESIUM DIBORIDE SUPERCONDUCTOR WIRE FOR TURBOELECTRIC PROPULSION SYSTEMS Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The availability of low AC loss magnesium diboride (MgB2) superconducting wires enables much lighter weight superconducting stator coils than with any other metal or...

  1. Advanced Manufacturing of Superconducting Magnets

    Science.gov (United States)

    Senti, Mark W.

    1996-01-01

    The development of specialized materials, processes, and robotics technology allows for the rapid prototype and manufacture of superconducting and normal magnets which can be used for magnetic suspension applications. Presented are highlights of the Direct Conductor Placement System (DCPS) which enables automatic design and assembly of 3-dimensional coils and conductor patterns using LTS and HTS conductors. The system enables engineers to place conductors in complex patterns with greater efficiency and accuracy, and without the need for hard tooling. It may also allow researchers to create new types of coils and patterns which were never practical before the development of DCPS. The DCPS includes a custom designed eight-axis robot, patented end effector, CoilCAD(trademark) design software, RoboWire(trademark) control software, and automatic inspection.

  2. 2G HTS wires made on 30 μm thick Hastelloy substrate

    Science.gov (United States)

    Sundaram, A.; Zhang, Y.; Knoll, A. R.; Abraimov, D.; Brownsey, P.; Kasahara, M.; Carota, G. M.; Nakasaki, R.; Cameron, J. B.; Schwab, G.; Hope, L. V.; Schmidt, R. M.; Kuraseko, H.; Fukushima, T.; Hazelton, D. W.

    2016-10-01

    REBCO (RE = rare earth) based high temperature superconducting (HTS) wires are now being utilized for the development of electric and electromagnetic devices for various industrial, scientific and medical applications. In the last several years, the increasing efforts in using the so-called second generation (2G) HTS wires for some of the applications require a further increase in their engineering current density (J e). The applications are those typically related to high magnetic fields where the higher J e of a REBCO wire, in addition to its higher irreversibility fields and higher mechanical strength, is already a major advantage over other superconducting wires. An effective way to increase the J e is to decrease the total thickness of a wire, for which using a thinner substrate becomes an obvious and attractive approach. By using our IBAD-MOCVD (ion beam assisted deposition-metal organic chemical vapor deposition) technology we have successfully made 2G HTS wires using a Hastelloy® C276 substrate that is only 30 μm in thickness. By using this thinner substrate instead of the typical 50 μm thick substrate and with a same critical current (I c), the J e of a wire can be increased by 30% to 45% depending on the copper stabilizer thickness. In this paper, we report the fabrication and characterization of the 2G HTS wires made on the 30 μm thick Hastelloy® C276 substrate. It was shown that with the optimization in the processing protocol, the surface of the thinner Hastelloy® C276 substrate can be readily electropolished to the quality needed for the deposition of the buffer stack. Same in the architecture as that on the standard 50 μm thick substrate, the buffer stack made on the 30 μm thick substrate showed an in-plane texture with a Δϕ of around 6.7° in the LaMnO3 cap layer. Low-temperature in-field transport measurement results suggest that the wires on the thinner substrate had achieved equivalent superconducting performance, most importantly the I

  3. Understanding Irreversible Degradation of Nb3Sn Wires with Fundamental Fracture Mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Yuhu [PPPL; Calzolaio, Ciro [Univ of Geneva; Senatore, Carmine [Univ of Geneva

    2014-08-01

    Irreversible performance degradation of advanced Nb3Sn superconducting wires subjected to transverse or axial mechanical loading is a critical issue for the design of large-scale fusion and accelerator magnets such as ITER and LHC. Recent SULTAN tests indicate that most cable-in-conduit conductors for ITER coils made of Nb3Sn wires processed by various fabrication techniques show similar performance degradation under cyclic loading. The irreversible degradation due to filament fracture and local strain accumulation in Nb3Sn wires cannot be described by the existing strand scaling law. Fracture mechanic modeling combined with X-ray diffraction imaging of filament micro-crack formation inside the wires under mechanical loading may reveal exciting insights to the wire degradation mechanisms. We apply fundamental fracture mechanics with a singularity approach to study influence of wire filament microstructure of initial void size and distribution to local stress concentration and potential crack propagation. We report impact of the scale and density of the void structure on stress concentration in the composite wire materials for crack initiation. These initial defects result in an irreversible degradation of the critical current beyond certain applied stress. We also discuss options to minimize stress concentration in the design of the material microstructure for enhanced wire performance for future applications.

  4. Negative effects of crystalline-SiC doping on the critical current density in Ti-sheathed MgB{sub 2}(SiC){sub y} superconducting wires

    Energy Technology Data Exchange (ETDEWEB)

    Liang, G [Department of Physics, Sam Houston State University, Huntsville, TX 77341 (United States); Fang, H [Department of Physics, Sam Houston State University, Huntsville, TX 77341 (United States); Luo, Z P [Microscopy and Imaging Center, Biological Sciences Building West, Texas A and M University, College Station, TX 77843-2257 (United States); Hoyt, C [Department of Physics, Sam Houston State University, Huntsville, TX 77341 (United States); Yen, F [Texas Center for Superconductivity, University of Houston, Houston, TX 77204-4006 (United States); Guchhait, S [Department of Physics, University of Texas at Austin, Austin, TX 78712 (United States); Lv, B [Department of Chemistry, University of Houston, Houston, TX 77204-5003 (United States); Markert, J T [Department of Physics, University of Texas at Austin, Austin, TX 78712 (United States)

    2007-07-15

    Ti-sheathed MgB{sub 2} wires doped with nanosize crystalline-SiC up to a concentration of 15 wt% SiC have been fabricated, and the effects of the SiC doping on the critical current density (J{sub c}) and other superconducting properties studied. In contrast with the previously reported results that nano-SiC doping with a doping range below 16 wt% usually enhances J{sub c}, particularly at higher fields, our measurements show that SiC doping decreases J{sub c} over almost the whole field range from 0 to 7.3 T at all temperatures. Furthermore, it is found that the degradation of J{sub c} becomes stronger at higher SiC doping levels, which is also in sharp contrast with the reported results that J{sub c} is usually optimized at doping levels near 10 wt% SiC. Our results indicate that these negative effects on J{sub c} could be attributed to the absence of significant effective pinning centres (mainly Mg{sub 2}Si) due to the high chemical stability of the crystalline-SiC particles.

  5. Structure of superconducting layers in bronze-processed and internal-tin Nb3Sn-based wires of various designs

    Science.gov (United States)

    Deryagina, I.; Popova, E.; Patrakov, E.; Valova-Zaharevskaya, E.

    2017-06-01

    The microstructure of Nb3Sn layers in multifilamentary composites manufactured by bronze technology and the internal-tin (IT) method differing in the strand design has been studied. The IT strands of International Thermonuclear Experimental Reactor (ITER) type and high-Jc type are characterized by both the higher Sn concentration and the higher fraction of equiaxed grains than bronze-route composites. In all the samples under study, the fraction of equiaxed grains correlates with the average concentration of Sn in Nb3Sn layers. The Ti doping of the bronze matrix in the bronze-processed wires results in the reduction in average grain sizes of Nb3Sn grains and in a higher fraction of equiaxed grains with a higher Sn concentration, which leads to a higher non-Cu Jc (calculated as a ratio of critical current Ic to a cross-sectional area of a strand without stabilizing Cu), 997 A/mm2 at 12 T, 4.2 K, compared to a composite of the same design with artificially Ti-doped Nb filaments. The ITER type IT strand demonstrates a somewhat higher fraction of equiaxed Nb3Sn grains with much larger average grain sizes (120 nm). The grain coarsening in this IT strand results in a decrease in Jc compared to other ITER type strands studied. The highest values of Jc are ensured in the high-Jc type of IT wires with 7 extended tin sources by the highest fraction (92%) of equiaxed Nb3Sn grains despite their coarser sizes (92 nm).

  6. Surface superconductivity in thin cylindrical Bi nanowire.

    Science.gov (United States)

    Tian, Mingliang; Wang, Jian; Ning, Wei; Mallouk, Thomas E; Chan, Moses H W

    2015-03-11

    The physical origin and the nature of superconductivity in nanostructured Bi remains puzzling. Here, we report transport measurements of individual cylindrical single-crystal Bi nanowires, 20 and 32 nm in diameter. In contrast to nonsuperconducting Bi nanoribbons with two flat surfaces, cylindrical Bi nanowires show superconductivity below 1.3 K. However, their superconducting critical magnetic fields decrease with their diameter, which is the opposite of the expected behavior for thin superconducting wires. Quasiperiodic oscillations of magnetoresistance were observed in perpendicular fields but were not seen in the parallel orientation. These results can be understood by a model of surface superconductivity with an enhanced surface-to-bulk volume in small diameter wires, where the superconductivity originates from the strained surface states of the nanowires due to the surface curvature-induced stress.

  7. Development of superconducting magnets fabricated with PAIR processed Bi-2212/Ag multilayer tapes; PAIR purosesu Bi-2212/Ag taso senzai wo mochiita chodedo magunetto no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Otani, N.; Koizumi, T.; Hasegawa, T. [Showa Electric Wire and Cable Co., Ltd., Kanagawa (Japan); Kitaguchi, H.; Kumakura, H.; Togano, K. [National Research Inst. for Metals, Tokyo (Japan); Miao, H. [Japan Science and Tech. Corp., Tsukuba (Japan)

    1999-06-07

    Bi2212 oxide superconducting wire rod has large critical current density at 20K or less. It is expected as practical conductors such as high magnetic field insert magnet and refrigerating machine cryogenic magnet. PAIR process, which we developed, introduced spare baking and intermediate preforming into the fabrication process of Bi2212/Ag wire rod. The superconductivity of the multilayer tape wire rod was more and more greatly improved, and it brought it close to the use conductor of the practical magnet. This time, in the coil using this wire rod, in order to examine electromagnetic force countermeasure in the high magnetic field application, the CuAg tape of which tensile strength was often high was used as reinforcing agent, and 2 kinds of double pancake coil were produced thermal conductivity. The coil was energized and was tested in 4.2K, in the external magnetic field. (NEDO)

  8. High-temperature strength of refractory-metal wires and consideration for composite applications

    Science.gov (United States)

    Petrasek, D. W.

    1972-01-01

    Tensile and stress-rupture tests were conducted on wires of W-Hf-C, W-Re-Hf-C, ASTAR 811C (a tantalum alloy), and B-88 (a columbium alloy) at room temperature, 1093 C (2000 F), and 1204 C (2200 F). Metallographic examinations were also made of the wire microstructure after testing. Ultimate tensile strength values up to 2170 meganewtons per square meter (314000 psi) at 1093 C (2000 F) and 1940 meganewtons per square meter (281 000 psi) at 1204 C (2200 F) were obtained for W-Re-Hf-C wire. The best strength values obtained for a 100-hour rupture life were, 1410 meganewtons per square meter (205 000 psi) at 1093 C (2000 F) and 910 meganewtons per square meter (132 000 psi) at 1240 C (2200 F) for W-Re-Hf-C wire. The properties obtained suggested that the wires studied showed promise as potential fiber reinforcement in the 1093 to 1204 C (2000 to 2200 F) temperature range.

  9. 10th International Symposium on Superconductivity

    CERN Document Server

    Hirabayashi, Izumi

    1998-01-01

    The International Symposium on Superconductivity, which has been held annu­ ally since 1988, is a forum for presenting the most up-to-date information about a broad range of research and development in superconductivity, from funda­ mental aspects to applications. More than 10 years have passed since the discovery of oxide superconductors and since various developments of applications began. It may be said that the prospects for application of oxide superconductors recently have opened up. Great progress has been made toward practical use, for example, of the flywheel, which uses bulk materials, and the high-performance cryo-cooled magnet made of bismuth wire. These were the results of persistent efforts to develop materials from the viewpoint of materials science and engineering. Also important is the progress in comprehensive understanding of high­ temperature superconductivity. Unique electronic properties of cuprates such as the non-Fermi liquid normal state, spin-charge separation, spin gap, and d-wav...

  10. Fabrication and characterization of iron pnictide wires and bulk materials through the powder-in-tube method

    Energy Technology Data Exchange (ETDEWEB)

    Ma Yanwei, E-mail: ywma@mail.iee.ac.c [Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, P.O. Box 2703, Beijing 100190 (China); Gao Zhaoshun; Qi Yanpeng; Zhang Xianping; Wang Lei; Zhang Zhiyu; Wang Dongliang [Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, P.O. Box 2703, Beijing 100190 (China)

    2009-05-01

    The recent discovery of superconductivity in the iron-based superconductors with very high upper critical fields presents a new possibility for practical applications, but fabricating fine-wire is a challenge because of mechanically hard and brittle powders and the toxicity and volatility of arsenic. In this paper, we report the synthesis and the physical characterization of iron pnictide wires and bulks prepared by the powder-in-tube method (PIT). A new class of high-T{sub c} iron pnictide composite wires, such as LaFeAsO{sub 1-x}F{sub x}, SmFeAsO{sub 1-x}F{sub x} and Sr{sub 1-x}K{sub x}FeAs, has been fabricated by the in situ PIT technique using Fe, Ta and Nb tubes. Microscopy and X-ray analysis show that the superconducting core is continuous, and retains phase composition after wire drawing and heat treatment. Furthermore, the wires exhibit a very weak J{sub c}-field dependence behavior even at high temperatures. The upper critical field H{sub c2}(0) value can exceed 100 T, surpassing those of MgB{sub 2} and all the low temperature superconductors and indicating a strong potential for applications requiring very high field. These results demonstrate the feasibility of producing superconducting pnictide composite wire. We also applied the one-step PIT method to synthesize the iron-based bulks, due to its convenience and safety. In fact, by using this technique, we have successfully discovered superconductivity at 35 K and 15 K in Eu{sub 0.7}Na{sub 0.3}Fe{sub 2}As{sub 2} and SmCoFeAsO compounds, respectively. These clearly suggest that the one-step PIT technique is unique and versatile and hence can be tailored easily for other rare earth derivatives of novel iron-based superconductors.

  11. Fabrication and characterization of iron pnictide wires and bulk materials through the powder-in-tube method

    Science.gov (United States)

    Ma, Yanwei; Gao, Zhaoshun; Qi, Yanpeng; Zhang, Xianping; Wang, Lei; Zhang, Zhiyu; Wang, Dongliang

    2009-05-01

    The recent discovery of superconductivity in the iron-based superconductors with very high upper critical fields presents a new possibility for practical applications, but fabricating fine-wire is a challenge because of mechanically hard and brittle powders and the toxicity and volatility of arsenic. In this paper, we report the synthesis and the physical characterization of iron pnictide wires and bulks prepared by the powder-in-tube method (PIT). A new class of high- Tc iron pnictide composite wires, such as LaFeAsO 1-xF x, SmFeAsO 1-xF x and Sr 1-xK xFeAs, has been fabricated by the in situ PIT technique using Fe, Ta and Nb tubes. Microscopy and X-ray analysis show that the superconducting core is continuous, and retains phase composition after wire drawing and heat treatment. Furthermore, the wires exhibit a very weak Jc-field dependence behavior even at high temperatures. The upper critical field Hc2(0) value can exceed 100 T, surpassing those of MgB 2 and all the low temperature superconductors and indicating a strong potential for applications requiring very high field. These results demonstrate the feasibility of producing superconducting pnictide composite wire. We also applied the one-step PIT method to synthesize the iron-based bulks, due to its convenience and safety. In fact, by using this technique, we have successfully discovered superconductivity at 35 K and 15 K in Eu 0.7Na 0.3Fe 2As 2 and SmCoFeAsO compounds, respectively. These clearly suggest that the one-step PIT technique is unique and versatile and hence can be tailored easily for other rare earth derivatives of novel iron-based superconductors.

  12. Inclusion control and fatigue properties of NiTi wires for medical applications

    Directory of Open Access Journals (Sweden)

    Beretta S.

    2014-06-01

    Full Text Available Superelastic wires of shape memory alloys are used for medical devices, but there has not been a systematic study about the correlations between fatigue properties and inclusion content. In this study we present a thorough investigation about the fatigue properties of 0.3 mm nitinol wires subjected to rotating bending fatigue. A comprehensive experimental campaign was conducted involving tests at different strain amplitudes for obtaining fatigue curves. The fracture surfaces of failed wires were analyzed through scanning electron microscopy, and data regarding the presence of particles and their morphology were recorded. We show qualitatively how inclusion dimensions affect fatigue. Finally, by means of extreme value statistics, we rate the particle dimensions of the four processes and correlate them to fatigue performance.

  13. The contact conductance of a one-dimensional wire partly embedded in a superconductor

    OpenAIRE

    Matthews, Raphael; Agam, Oded

    2007-01-01

    The conductance through a semi-infinite one-dimensional wire, partly embedded in a superconducting bulk electrode, is studied. When the electron-electron interactions within the wire are strongly repulsive, the wire effectively decouples from the superconductor. If they are moderately or weakly repulsive, the proximity of the superconductor induces superconducting order in the segment of the wire embedded in it. In this case it is shown that the conductance exhibits a crossover from conductiv...

  14. Design of 154 kV Extra-High-Voltage Prototype SF6 Bushing for Superconducting Electric Power Applications

    Science.gov (United States)

    Koo, Ja-yoon; Seong, Jae-gyu; Hwang, Jae-sang; Lee, Bang-wook; Lee, Sang-hwa

    2012-09-01

    One of the critical components to be developed for high-voltage superconducting devices, such as superconducting transformers, cables, and fault current limiters, is a high-voltage bushing to supply a high current to devices without insulation difficulties in cryogenic environments. Unfortunately, suitable bushings for high-temperature-superconductivity (HTS) equipment have not been fully developed to address cryogenic insulation issues. As a fundamental step towards developing the optimum design of the 154 kV prototype SF6 bushing of HTS devices, the puncture and creepage breakdown voltages of glass-fiber-reinforced-plastic (GFRP) were analyzed with a variety of configurations of electrodes and gap distances in the insulation material. And design factors of high-voltage cryogenic bushings were obtained from the result of tests. Finally, the withstand voltage tests of manufacturing a 154 kV extra-high-voltage (EHV) prototype bushing has been performed. Consequently, we verified the insulation level of the newly designed 154 kV EHV cryogenic prototype bushings for superconducting electric power applications.

  15. Implementation and Applications of the Method of Auxiliary Sources for Analysis of Smooth Scatterers and Wires

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal

    2007-01-01

    This report documents the implementation of Method of Auxiliary Sources techniques developed for smooth scatterers and wire scatterers. The work was done in the course of the PhD project "Electronically Steerable Antennas for Satellite Communication" where the techniques were employed to investig......This report documents the implementation of Method of Auxiliary Sources techniques developed for smooth scatterers and wire scatterers. The work was done in the course of the PhD project "Electronically Steerable Antennas for Satellite Communication" where the techniques were employed...

  16. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  17. wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  18. Meissner effect in superconducting microtraps

    Energy Technology Data Exchange (ETDEWEB)

    Cano, Daniel

    2009-04-30

    This thesis investigates the impact of the Meissner effect on magnetic microtraps for ultracold atoms near superconducting microstructures. This task has been accomplished both theoretically and experimentally. The Meissner effect distorts the magnetic fields near superconducting surfaces, thus altering the parameters of magnetic microtraps. Both computer simulations and experimental measurements demonstrate that the Meissner effect shortens the distance between the magnetic microtrap and the superconducting surface, reduces the magnetic-field gradients and dramatically lowers the trap depth. A novel numerical method for calculating magnetic fields in atom chips with superconducting microstructures has been developed. This numerical method overcomes the geometrical limitations of other calculation techniques and can solve superconducting microstructures of arbitrary geometry. The numerical method has been used to calculate the parameters of magnetic microtraps in computer-simulated chips containing thin-film wires. Simulations were carried out for both the superconducting and the normal-conducting state, and the differences between the two cases were analyzed. Computer simulations have been contrasted with experimental measurements. The experimental apparatus generates a magnetic microtrap for ultracold Rubidium atoms near a superconducting Niobium wire of circular cross section. The design and construction of the apparatus has met the challenge of integrating the techniques for producing atomic quantum gases with the techniques for cooling solid bodies to cryogenic temperatures. By monitoring the position of the atom cloud, one can observe how the Meissner effect influences the magnetic microtrap. (orig.)

  19. Optimization of a Superconducting Magnetic Energy Storage Device via a CPU-Efficient Semi-Analytical Simulation

    CERN Document Server

    Dimitrov, I K; Solovyov, V F; Chubar, O; Li, Qiang

    2014-01-01

    Recent advances in second generation (YBCO) high temperature superconducting wire could potentially enable the design of super high performance energy storage devices that combine the high energy density of chemical storage with the high power of superconducting magnetic storage. However, the high aspect ratio and considerable filament size of these wires requires the concomitant development of dedicated optimization methods that account for both the critical current density and ac losses in type II superconductors. Here, we report on the novel application and results of a CPU-efficient semi-analytical computer code based on the Radia 3D magnetostatics software package. Our algorithm is used to simulate and optimize the energy density of a superconducting magnetic energy storage device model, based on design constraints, such as overall size and number of coils. The rapid performance of the code is pivoted on analytical calculations of the magnetic field based on an efficient implementation of the Biot-Savart...

  20. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  1. Winding workshop for the ISR low beta Superconducting Quadrupole Prototype

    CERN Multimedia

    1975-01-01

    From right to left one sees the wire spool with its electro-magnetic brake to ensure a constant tension of the superconducting wire, a pulley with a wire length recording and the winding machine. In front on the table a finished coil. In the back the heavy clamping tool. See also 7510213X, 7510213X.

  2. A Cryogenic Magnetostrictive Actuator Using a Persistent High Temperature Superconducting Magnet. Part 1; Concept and Design

    Science.gov (United States)

    Horner, Garnett; Bromberg, Leslie; Teter, J. P.

    2000-01-01

    Cryogenic magnetostrictive materials, such as rare earth zinc crystals, offer high strains and high forces with minimally applied magnetic fields, making the material ideally suited for deformable optics applications. For cryogenic temperature applications the use of superconducting magnets offer the possibility of a persistent mode of operation, i.e., the magnetostrictive material will maintain a strain field without power. High temperature superconductors (HTS) are attractive options if the temperature of operation is higher than 10 degrees Kelvin (K) and below 77 K. However, HTS wires have constraints that limit the minimum radius of winding, and even if good wires can be produced, the technology for joining superconducting wires does not exist. In this paper, the design and capabilities of a rare earth zinc magnetostrictive actuator using bulk HTS is described. Bulk superconductors can be fabricated in the sizes required with excellent superconducting properties. Equivalent permanent magnets, made with this inexpensive material, are persistent, do not require a persistent switch as in HTS wires, and can be made very small. These devices are charged using a technique which is similar to the one used for charging permanent magnets, e.g., by driving them into saturation. A small normal conducting coil can be used for charging or discharging. Because of the magnetic field capability of the superconductor material, a very small amount of superconducting magnet material is needed to actuate the rare earth zinc. In this paper, several designs of actuators using YBCO and BSCCO 2212 superconducting materials are presented. Designs that include magnetic shielding to prevent interaction between adjacent actuators will also be described. Preliminary experimental results and comparison with theory for BSCCO 2212 with a magnetostrictive element will be discussed.

  3. 新型聚醚醚酮线缆及其应用%Novel Polyetheretherketone Wires & Cables and Their Applications

    Institute of Scientific and Technical Information of China (English)

    殷毅; 李亚明; 郭荣荣; 袁常俊

    2013-01-01

    The novel polyetheretherketone wires and cables is an application example of a special engineering plastics,polyetheretherketone,in wire and cable.Novel polyetheretherketone wires and cables feature high temperature resistance,chemical corrosion resistance,radiation resistance,hydrolysis resistance,thin thickness,light weight,high strength,good insulation resistance and dielectric voltage withstand performance,etc.so they can be used in aerospace,petroleum chemistry,nuclear industry,automotive and rail transportation,health and other fields.%新型聚醚醚酮(PEEK)线缆是特种工程塑料PEEK在电线电缆中的应用.新型PEEK电线电缆具有耐高温、耐化学腐蚀、耐辐照、耐水解,绝缘厚度薄、重量轻、强度高、绝缘电阻和介质耐压性能好等特点,因而可作为传统耐高温线缆的更新换代产品用于航空航天、核工业、石油化工、汽车及轨道交通、医疗卫生事业等领域.

  4. High critical temperature nodal superconductors as building block for time-reversal invariant topological superconductivity

    Science.gov (United States)

    Trani, F.; Campagnano, G.; Tagliacozzo, A.; Lucignano, P.

    2016-10-01

    We study possible applications of high critical temperature nodal superconductors for the search for Majorana bound states in the DIII class. We propose a microscopic analysis of the proximity effect induced by d -wave superconductors on a semiconductor wire with strong spin-orbit coupling. We characterize the induced superconductivity on the wire employing a numerical self-consistent tight-binding Bogoliubov-de Gennes approach, and analytical considerations on the Green's function. The order parameter induced on the wire, the pair correlation function, and the renormalization of the Fermi points are analyzed in detail, as well as the topological phase diagram in the case of weak coupling. We highlight optimal Hamiltonian parameters to access the nontrivial topological phase which could display time-reversal invariant Majorana doublets at the boundaries of the wire.

  5. PEEK (polyether-ether-ketone)-coated nitinol wire: Film stability for biocompatibility applications

    Science.gov (United States)

    Sheiko, Nataliia; Kékicheff, Patrick; Marie, Pascal; Schmutz, Marc; Jacomine, Leandro; Perrin-Schmitt, Fabienne

    2016-12-01

    High quality biocompatible poly-ether-ether-ketone (PEEK) coatings were produced on NiTi shape memory alloy wires using dipping deposition from colloidal aqueous PEEK dispersions after substrate surface treatment. The surface morphology and microstructure were investigated by Scanning Electron Microscopy at every step of the process from the as-received Nitinol substrate to the ultimate PEEK-coated NiTi wire. Nanoscratch tests were carried out to access the adhesive behavior of the polymer coated film to the NiTi. The results indicate that the optimum process conditions in cleaning, chemical etching, and electropolishing the NiTi, were the most important and determining parameters to be achieved. Thus, high quality PEEK coatings were obtained on NiTi wires, straight or curved (even with a U-shape) with a homogeneous microstructure along the wire length and a uniform thickness of 12 μm without any development of cracks or the presence of large voids. The biocompatibility of the PEEK coating film was checked in fibrobast cultured cells. The coating remains stable in biological environment with negligible Ni ion release, no cytotoxicity, and no delamination observed with time.

  6. Simulations of quantum transport in nanoscale systems: application to atomic gold and silver wires

    DEFF Research Database (Denmark)

    Mozos, J.L.; Ordejon, P.; Brandbyge, Mads

    2002-01-01

    's function techniques are used to calculate the quantum conductance. Here we apply the method to the study of the electronic transport in wires of gold and silver with atomic thickness. We show the results of our calculations, and compare with some of the abundant experimental data on these systems....

  7. Development of Ti-sheathed MgB{sub 2} wires with high critical current density

    Energy Technology Data Exchange (ETDEWEB)

    Liang, G [Department of Physics, Sam Houston State University, Huntsville, TX 77341 (United States); Fang, H [Department of Physics, Sam Houston State University, Huntsville, TX 77341 (United States); Hanna, M [Department of Mechanical Engineering and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-4006 (United States); Yen, F [Texas Center for Superconductivity, University of Houston, Houston, TX 77204-4006 (United States); Lv, B [Department of Chemistry, University of Houston, Houston, TX 77204-5003 (United States); Alessandrini, M [Department of Mechanical Engineering and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-4006 (United States); Keith, S [Department of Physics, Sam Houston State University, Huntsville, TX 77341 (United States); Hoyt, C [Department of Physics, Sam Houston State University, Huntsville, TX 77341 (United States); Tang, Z [Department of Chemistry, University of Houston, Houston, TX 77204-5003 (United States); Salama, K [Department of Mechanical Engineering and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-4006 (United States)

    2006-11-15

    Working towards developing lightweight superconducting magnets for future space and other applications, we have successfully fabricated mono-core Ti-sheathed MgB{sub 2} wires by the powder-in-tube method. The wires were characterized by magnetization, electrical resistivity, x-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry measurements. The results indicate that the Ti sheath does not react with the magnesium and boron, and the present wire rolling process can produce MgB{sub 2} wires with a superconducting volume fraction of at least 64% in the core. Using the Bean model, it was found that at 5 K, the magnetic critical current densities, J{sub c}, measured in magnetic fields of 0, 5, and 8 T are about 4.2 x 10{sup 5}, 3.6 x 10{sup 4}, and 1.4 x 10{sup 4} A cm{sup -2}, respectively. At 20 K and 0 T, the magnetic J{sub c} is about 2.4 x 10{sup 5} A cm{sup -2}. These results show that at zero and low fields, the values of the magnetic J{sub c} for Ti-sheathed MgB{sub 2} wires are comparable with the best results available for the Fe-sheathed MgB{sub 2} wires. At high fields, however, the J{sub c} for Ti-sheathed MgB{sub 2} wires appears higher than that for the Fe-sheathed MgB{sub 2} wires.

  8. Superconducting pulsed magnets

    CERN Document Server

    CERN. Geneva

    2006-01-01

    Lecture 1. Introduction to Superconducting Materials Type 1,2 and high temperature superconductors; their critical temperature, field & current density. Persistent screening currents and the critical state model. Lecture 2. Magnetization and AC Loss How screening currents cause irreversible magnetization and hysteresis loops. Field errors caused by screening currents. Flux jumping. The general formulation of ac loss in terms of magnetization. AC losses caused by screening currents. Lecture 3. Twisted Wires and Cables Filamentary composite wires and the losses caused by coupling currents between filaments, the need for twisting. Why we need cables and how the coupling currents in cables contribute more ac loss. Field errors caused by coupling currents. Lecture 4. AC Losses in Magnets, Cooling and Measurement Summary of all loss mechanisms and calculation of total losses in the magnet. The need for cooling to minimize temperature rise in a magnet. Measuring ac losses in wires and in magnets. Lecture 5. Stab...

  9. Superconducting coil development and motor demonstration: Overview

    Science.gov (United States)

    Gubser, D. U.

    1995-12-01

    Superconducting bismuth-cuprate wires, coils, and magnets are being produced by industry as part of a program to test the viability of using such magnets in Naval systems. Tests of prototype magnets, coils, and wires reveal progress in commercially produced products. The larger magnets will be installed in an existing superconducting homopolar motor and operated initially at 4.2K to test the performance. It is anticipated that approximately 400 Hp will be achieved by the motor. This article reports on the initial tests of the magnets, coils, and wires as well as the development program to improve their performance.

  10. Strategies for "wiring" redox-active proteins to electrodes and applications in biosensors, biofuel cells, and nanotechnology.

    Science.gov (United States)

    Nöll, Tanja; Nöll, Gilbert

    2011-07-01

    In this tutorial review the basic approaches to establish electrochemical communication between redox-active proteins and electrodes are elucidated and examples for applications in electrochemical biosensors, biofuel cells and nanotechnology are presented. The early stage of protein electrochemistry is described giving a short overview over electron transfer (ET) between electrodes and proteins, followed by a brief introduction into experimental procedures for studying proteins at electrodes and possible applications arising thereof. The article starts with discussing the electrochemistry of cytochrome c, the first redox-active protein, for which direct reversible ET was obtained, under diffusion controlled conditions and after adsorption to electrodes. Next, examples for the electrochemical study of redox enzymes adsorbed on electrodes and modes of immobilization are discussed. Shortly the experimental approach for investigating redox-active proteins adsorbed on electrodes is outlined. Possible applications of redox enzymes in electrochemical biosensors and biofuel cells working by direct ET (DET) and mediated ET (MET) are presented. Furthermore, the reconstitution of redox active proteins at electrodes using molecular wire-like units in order to "wire" the proteins to the electrode surface and possible applications in nanotechnology are discussed.

  11. A superconducting shield to protect astronauts

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    The CERN Superconductors team in the Technology department is involved in the European Space Radiation Superconducting Shield (SR2S) project, which aims to demonstrate the feasibility of using superconducting magnetic shielding technology to protect astronauts from cosmic radiation in the space environment. The material that will be used in the superconductor coils on which the project is working is magnesium diboride (MgB2), the same type of conductor developed in the form of wire for CERN for the LHC High Luminosity Cold Powering project.   Image: K. Anthony/CERN. Back in April 2014, the CERN Superconductors team announced a world-record current in an electrical transmission line using cables made of the MgB2 superconductor. This result proved that the technology could be used in the form of wire and could be a viable solution for both electrical transmission for accelerator technology and long-distance power transportation. Now, the MgB2 superconductor has found another application: it wi...

  12. DNA mediated wire-like clusters of self-assembled TiO₂ nanomaterials: supercapacitor and dye sensitized solar cell applications.

    Science.gov (United States)

    Nithiyanantham, U; Ramadoss, Ananthakumar; Ede, Sivasankara Rao; Kundu, Subrata

    2014-07-21

    A new route for the formation of wire-like clusters of TiO₂ nanomaterials self-assembled in DNA scaffold within an hour of reaction time is reported. TiO₂ nanomaterials are synthesized by the reaction of titanium-isopropoxide with ethanol and water in the presence of DNA under continuous stirring and heating at 60 °C. The individual size of the TiO₂ NPs self-assembled in DNA and the diameter of the wires can be tuned by controlling the DNA to Ti-salt molar ratios and other reaction parameters. The eventual diameter of the individual particles varies between 15 ± 5 nm ranges, whereas the length of the nanowires varies in the 2-3 μm range. The synthesized wire-like DNA-TiO₂ nanomaterials are excellent materials for electrochemical supercapacitor and DSSC applications. From the electrochemical supercapacitor experiment, it was found that the TiO₂ nanomaterials showed different specific capacitance (Cs) values for the various nanowires, and the order of Cs values are as follows: wire-like clusters (small size) > wire-like clusters (large size). The highest Cs of 2.69 F g(-1) was observed for TiO₂ having wire-like structure with small sizes. The study of the long term cycling stability of wire-like clusters (small size) electrode were shown to be stable, retaining ca. 80% of the initial specific capacitance, even after 5000 cycles. The potentiality of the DNA-TiO₂ nanomaterials was also tested in photo-voltaic applications and the observed efficiency was found higher in the case of wire-like TiO₂ nanostructures with larger sizes compared to smaller sizes. In future, the described method can be extended for the synthesis of other oxide based materials on DNA scaffold and can be further used in other applications like sensors, Li-ion battery materials or treatment for environmental waste water.

  13. Biomedical Applications of Antibacterial Nanofiber Mats Made of Electrospinning with Wire Electrodes

    Directory of Open Access Journals (Sweden)

    Yi-Jun Pan

    2016-02-01

    Full Text Available Twisted stainless steel wires are used as wire electrodes for electrospinning the polyvinyl alcohol (PVA/zinc citrate nanofiber mats. The morphology and diameter of the nanofibers in PVA/zinc citrate nanofiber mats are evaluated. We measured the antibacterial efficacy against Staphylococcus aureus (S. aureus and Escherichia coli (E. coli of the nanofiber mats. We also examined the cell adhesion affinity of mammalian tissue culture cells on these nanofiber mats. Our results indicate that an increase in zinc citrate increases the viscosity and electrical conductivity of PVA solution. In addition, increasing zinc citrate results in a smaller diameter of nanofibers that reaches below 100 nm. According to the antibacterial test results, increasing zinc citrate enlarges the inhibition zone of S. aureus but only has a bacteriostatic effect against E. coli. Finally, cell adhesion test results indicate that all nanofiber mats have satisfactory cell attachment regardless of the content of zinc citrate.

  14. Application of 3-Dimensional Printing Technology to Kirschner Wire Fixation of Adolescent Condyle Fracture.

    Science.gov (United States)

    Dong, Zhiwei; Li, Qihong; Bai, Shizhu; Zhang, Li

    2015-10-01

    Condyle fractures are common in children and are increasingly treated with open reduction. Three-dimensional printing has developed into an important method of assisting surgical treatment. This report describes the case of a 14-year-old patient treated for a right condyle fracture at the authors' hospital. Preoperatively, the authors designed a surgical guide using 3-dimensional printing and virtual surgery. The 3-dimensional surgical guide allowed accurate alignment of the fracture using Kirschner wire without additional dissection and tissue injury. Kirschner wire fixation augmented by 3-dimensional printing technology produced a good outcome in this adolescent condyle fracture. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Isolated Wired and Wireless Battery Charger with Integrated Boost Converter for PEV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Chinthavali, Madhu Sudhan [ORNL; Onar, Omer C [ORNL; Campbell, Steven L [ORNL; Tolbert, Leon M [ORNL

    2015-01-01

    Integrated charger topologies that have been researched so far are with the dc-dc converters and the charging functionality usually have no isolation in the system. Isolation is an important feature that is required for user interface systems that have grid connections and therefore is a major limitation that needs to be addressed along with the integrated functionality. This study features a unique way of combining the wired and wireless charging functionalities with vehicle side boost converter integration and maintaining the isolation to provide the best solution to the plug-in electric vehicle (PEV) users. The new performance of the proposed architecture is presented for wired and wireless charging options at different power levels.

  16. Mechanical characteristics of novel polyester/NiTi wires braided composite stent for the medical application

    Science.gov (United States)

    Zou, Qiuhua; Xue, Wen; Lin, Jing; Fu, Yijun; Guan, Guoping; Wang, Fujun; Wang, Lu

    Stents have been widely used in percutaneous surgery to treat stenosis diseases. The braided NiTi stent, as a promising prototype, still has limitations of low radial force and loose structure. In the present study, a newly integrated composite stent was designed and braided with NiTi wires and polyester multifilament yarns by textile technology. The mechanical properties of four composite stents and the control bare NiTi stent were evaluated by in vitro compression, bending and anti-torsion tests. The results showed that integrated polyester/NiTi composite stents were superior in radial support. The stents could keep patency even when highly curved and had lower stent straightening force. Composite stents with certain structure stayed stable under twisting. The configuration of NiTi wires in composite stents could significantly impact stent deformation under twisting.

  17. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  18. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  19. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  20. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  1. The Application of Dual-wire Balloon in The Treatment of Coronary Bifurcation Lesions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objectives To assess the efficiency and safety of dual-wire balloon angioplasty side branch combined stenting the main branch in the treatment of coronary bifurcation lesions. Methods This study included thirty-six patients with 41 coronary bifurcation lesions. Selective dual-wire balloon angioplasty was performed in side branch and/or in main branch, and implantation of stents was performed in main branch only. Clinical outcome and major adverse cardiac events were observed inhospital and follow-up. Results Success rate of side branch dilatation before main branch stenting was 100%; main branch direct stenting performed in 4 cases; success main branch dilatation performed in the other 37 cases; kissing technique was performed successfully in 5 cases, which side branch was jailed after main branch stenting with TIMI grade 0-2 flow. No Q-wave myocardial infarction, acute revascularization and death occurred during in-hospital.Clinical follow-up was available in all patients. No Q-wave myocardial infarction, revascularization and death occurred, angina pectoris recurred in three patients,released by strengthen drug treatment. Conclusions Dual-wire balloon angioplasty side branch combined stenting the main branch is simple, safe and effective for the treatment of coronary bifurcation lesions.

  2. A constrained theory for single crystal shape memory wires with application to restrained recovery

    Science.gov (United States)

    Rizzoni, Raffaella

    2011-07-01

    The theory of thin wires developed in Dret and Meunier (Comptes Rendus de l'Académie des Sciences. Série I. Mathématique 337:143-147, 2003) is adapted to phase-transforming materials with large elastic moduli in the sense discussed in James and Rizzoni (J Elast 59:399-436, 2000). The result is a one-dimensional constitutive model for shape memory wires, characterized by a small number of material constants. The model is used to analyze self-accommodated and detwinned microstructures and to study superelasticity. It also turns out that the model successfully reproduces the behavior of shape memory wires in experiments of restrained recovery (Tsoi et al. in Mater Sci Eng A 368:299-310, 2004; Tsoi in 50:3535-3544, 2002; S̆ittner et al. in Mater Sci Eng A 286:298-311, 2000; vokoun in Smart Mater Struct 12:680-685, 2003; Zheng and Cui in Intermetallics 12:1305-1309, 2004; Zheng et al. in J Mater Sci Technol 20(4):390-394, 2004). In particular, the model is able to predict the shift to higher transformation temperatures on heating. The model also captures the effect of prestraining on the evolution of the recovery stress and of the martensite volume fraction.

  3. Academic training: Applied superconductivity

    CERN Multimedia

    2007-01-01

    LECTURE SERIES 17, 18, 19 January from 11.00 to 12.00 hrs Council Room, Bldg 503 Applied Superconductivity : Theory, superconducting Materials and applications E. PALMIERI/INFN, Padova, Italy When hearing about persistent currents recirculating for several years in a superconducting loop without any appreciable decay, one realizes that we are dealing with a phenomenon which in nature is the closest known to the perpetual motion. Zero resistivity and perfect diamagnetism in Mercury at 4.2 K, the breakthrough during 75 years of several hundreds of superconducting materials, the revolution of the "liquid Nitrogen superconductivity"; the discovery of still a binary compound becoming superconducting at 40 K and the subsequent re-exploration of the already known superconducting materials: Nature discloses drop by drop its intimate secrets and nobody can exclude that the last final surprise must still come. After an overview of phenomenology and basic theory of superconductivity, the lectures for this a...

  4. Depositing High-T(sub c) Superconductors On Normal-Conductor Wires

    Science.gov (United States)

    Kirlin, Peter S.

    1994-01-01

    Experiments have demonstrated feasibility of depositing thin layers of high-T(sub c) superconductor on normally electrically conductive wires. Superconductivity evident at and below critical temperature (T{sub c}) of 71 K. OMCVD, organometallic vapor deposition, apparatus coats Ag wire with layer high-T(sub c) superconductor. Superconductive phase of this material formed subsequently by annealing under controlled conditions.

  5. Application of internal fixation of steel-wire limited loop in early Achilles tendon rupture

    Institute of Scientific and Technical Information of China (English)

    Zhe Chen; Jia-Sen Wei; Zhao-Yang Hou; Jiong Hu; Yan-Guang Cao; Qi-Xin Chen

    2013-01-01

    Objective:To explore the clinical effect and safety of internal fixation of steel-wire limited loop in earlyAchilles tendon rupture.Methods:Seventy-six patients respectively with early transected and avulsed types ofAchilles tendon rupture were selected and treated with internal fixation of steel-wire limited loop.The patients began to take exercise for their lower limbs through continous passive motion as early as possible after surgical repair, and the loops were removed after3-5 months.Six months later, the condition of complications includingAchilles tendon re-rupture, wound fistula, wound infection and skin necrosis, cutaneous sensation in sural nerve dominance region, time back to preinjury work or learning as well as time to physical activities were observed.One year later, the therapeutic effect was evaluated, and the maximum circumferences of bilateral legs and ruptured plane circumferences ofAchilles tendon were measured.Results:The wound of all patients healed well, no complications likeAchilles tendon re-rupture, wound fistula, wound infection and skin necrosis occured, and the cutaneous sensation in sural nerve dominance region was normal.The mean time back to preinjury workor learning as well as to pysical activities of all patients were respectively10 and22 weeks.Seventy out of76 patients(92.1%) achieved an excellent effect, and6(7.9%) good effect.The excellent and good rate came up to100%.The maximum circumference in the affected leg decreased to 2 mm averagely compared with the offside, while the ruptured plane circumferences ofAchilles tendon in the affected side increased to2.2 mm compared with the offside.Conclusions:For earlyAchilles tendon rupture, internal fixation of steel-wire limited loop can recover the ankle function better, return to the preinjury state in the shortest time, and has few complications.

  6. Application of internal fixation of steel-wire limited loop in early Achilles tendon rupture.

    Science.gov (United States)

    Chen, Zhe; Wei, Jia-Sen; Hou, Zhao-Yang; Hu, Jiong; Cao, Yan-Guang; Chen, Qi-Xin

    2013-11-01

    To explore the clinical effect and safety of internal fixation of steel-wire limited loop in early Achilles tendon rupture. Seventy-six patients respectively with early transected and avulsed types of Achilles tendon rupture were selected and treated with internal fixation of steel-wire limited loop. The patients began to take exercise for their lower limbs through continous passive motion as early as possible after surgical repair, and the loops were removed after 3-5 months. Six months later, the condition of complications including Achilles tendon re-rupture, wound fistula, wound infection and skin necrosis, cutaneous sensation in sural nerve dominance region, time back to preinjury work or learning as well as time to physical activities were observed. One year later, the therapeutic effect was evaluated, and the maximum circumferences of bilateral legs and ruptured plane circumferences of Achilles tendon were measured. The wound of all patients healed well, no complications like Achilles tendon re-rupture, wound fistula, wound infection and skin necrosis occured, and the cutaneous sensation in sural nerve dominance region was normal. The mean time back to preinjury work or learning as well as to pysical activities of all patients were respectively 10 and 22 weeks. Seventy out of 76 patients (92.1%) achieved an excellent effect, and 6 (7.9%) good effect. The excellent and good rate came up to 100%. The maximum circumference in the affected leg decreased to 2 mm averagely compared with the offside, while the ruptured plane circumferences of Achilles tendon in the affected side increased to 2.2 mm compared with the offside. For early Achilles tendon rupture, internal fixation of steel-wire limited loop can recover the ankle function better, return to the preinjury state in the shortest time, and has few complications. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  7. Microwave power coupler for a superconducting multiple-cell cavity for accelerator application and its testing procedures

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jianjian [Illinois Inst. of Technology, Chicago, IL (United States)

    2008-12-01

    Superconducting cavity resonators offer the advantage of high field intensity for a given input power, making them an attractive contender for particle accelerator applications. Power coupling into a superconducting cavity employed in a particle accelerator requires unique provisions to maintain high vacuum and cryogenic temperature on the cavity side, while operating with ambient conditions on the source side. Components introduced to fulfill mechanical requirements must show negligible obstruction of the propagation of the microwave with absence of critical locations that may give rise to electron multipaction, leading to a multiple section design, instead of an aperture, a probe, or a loop structure as found in conventional cavities. A coaxial power coupler for a superconducting multiple-cell cavity at 3.9 GHz has been developed. The cavity is intended to be employed as an accelerator to provide enhanced electron beam quality in a free-electron laser in Hamburg (FLASH) user facility. The design of the coupler called for two windows to sustain high vacuum in the cavity and two bellows to accommodate mechanical dimensional changes resulting from cryogenics. Suppression of multipacting was accomplished by the choice of conductor dimensions and materials with low second yield coefficients. Prior to integration with the cavity, the coupler was tested for intrinsic properties in a back-to-back configuration and conditioned for high-power operation with increasing power input. Maximum incident power was measured to be 61 kW. When integrated with the superconducting cavity, a loaded quality factor of 9 x 10 5 was measured by transient method. Coupler return loss and insertion loss were estimated to be around -21 dB and -0.2 dB, respectively.

  8. Simulations of quantum transport in nanoscale systems: application to atomic gold and silver wires

    DEFF Research Database (Denmark)

    Mozos, J.L.; Ordejon, P.; Brandbyge, Mads

    2002-01-01

    . The potential drop profile and induced electronic current (and therefore the conductance) are obtained from first principles. The method takes into account the atomic structure of both the nanoscale structure and the semi-infinite electrodes through which the potential is applied. Non-equilibrium Green......'s function techniques are used to calculate the quantum conductance. Here we apply the method to the study of the electronic transport in wires of gold and silver with atomic thickness. We show the results of our calculations, and compare with some of the abundant experimental data on these systems....

  9. Application of a Schlieren diagnostic to the behavior of exploding bridge wire and laser detonators

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Michael J [Los Alamos National Laboratory; Clarke, Steven A [Los Alamos National Laboratory; Munger, Alan C [Los Alamos National Laboratory; Thomas, Keith A [Los Alamos National Laboratory

    2009-01-01

    Even though the exploding bridge wire (EBW) detonator has been in use for over 60 years, there are still discussions about the mechanism for achieving detonation. Los Alamos has been developing a high-power laser detonator to function in a manner similar to an EBW. Schlieren imaging techniques are applied to laser-driven detonator output in polydimethylsiloxane (POMS) samples to investigate the time-dependent geometry of the shock wave and to obtain instantaneous measurements of shock-front velocity. Velocity Hugoniot data are used to convert measured shock velocities to corresponding particle velocities, allowing instantaneous shock pressures to be obtained via Rankine-Hugoniot relations across the shock.

  10. Fabrication of high-Tc superconducting hot electron bolometers for terahertz mixer applications

    Science.gov (United States)

    Villegier, Jean-Claude; Degardin, Annick F.; Guillet, Bruno; Houze, Frederic; Kreisler, Alain J.; Chaubet, Michel

    2005-03-01

    Superconducting Hot Electron Bolometer (HEB) mixers are a competitive alternative to Schottky diode mixers or other conventional superconducting receiver technologies in the terahertz frequency range because of their ultrawide bandwidth (from millimeter waves to the visible), high conversion gain, and low intrinsic noise level, even at 77 K. A new technological process has been developed to realize HEB mixers based on high temperature superconducting materials, using 15 to 40 nm thick layers of YBa2Cu3O7-δ (YBCO), sputtered on MgO (100) substrates by hollow cathode magnetron sputtering. Critical temperature values of YBCO films were found in the 85 to 91 K range. Sub-micron HEB bridges (0.8 μm x 0.8 μm) were obtained by combining electronic and UV lithography followed by selective etching techniques. Realization of YBCO HEB coupling to planar integrated gold antennas was also considered.

  11. Superconducting transistor

    Science.gov (United States)

    Gray, Kenneth E.

    1979-01-01

    A superconducting transistor is formed by disposing three thin films of superconducting material in a planar parallel arrangement and insulating the films from each other by layers of insulating oxides to form two tunnel junctions. One junction is biased above twice the superconducting energy gap and the other is biased at less than twice the superconducting energy gap. Injection of quasiparticles into the center film by one junction provides a current gain in the second junction.

  12. Superconductivity and superconductive electronics

    Science.gov (United States)

    Beasley, M. R.

    1990-12-01

    The Stanford Center for Research on Superconductivity and Superconductive Electronics is currently focused on developing techniques for producing increasingly improved films and multilayers of the high-temperature superconductors, studying their physical properties and using these films and multilayers in device physics studies. In general the thin film synthesis work leads the way. Once a given film or multilayer structure can be made reasonably routinely, the emphasis shifts to studying the physical properties and device physics of these structures and on to the next level of film quality or multilayer complexity. The most advanced thin films synthesis work in the past year has involved developing techniques to deposit a-axis and c-axis YBCO/PBCO superlattices and related structures. The in-situ feature is desirable because no solid state reactions with accompanying changes in volume, morphology, etc., that degrade the quality of the film involved.

  13. Relativistic dynamics of superfluid-superconducting mixtures in the presence of topological defects and the electromagnetic field, with application to neutron stars

    CERN Document Server

    Gusakov, Mikhail

    2016-01-01

    The relativistic dynamic equations are derived for a superfluid-superconducting mixture coupled to the electromagnetic field. For definiteness and bearing in mind possible applications of our results to neutron stars, it is assumed that the mixture is composed of superfluid neutrons, superconducting protons, and normal electrons. Proton superconductivity of both I and II types is analysed, and possible presence of neutron and proton vortices (or magnetic domains in the case of type-I proton superconductivity) is allowed for. The derived equations neglect all dissipative effects except for the mutual friction dissipation and are valid for arbitrary temperatures (i.e. they do not imply that all nucleons are paired), which is especially important for magnetar conditions. It is demonstrated that these general equations can be substantially simplified for typical neutron stars, for which a kind of magnetohydrodynamic approximation is justified. Our results are compared to the nonrelativistic formulations existing ...

  14. Uniform transport performance of a 100 m-class multifilament MgB2 wire fabricated by an internal Mg diffusion process

    Science.gov (United States)

    Wang, Dongliang; Xu, Da; Zhang, Xianping; Yao, Chao; Yuan, Pusheng; Ma, Yanwei; Oguro, Hidetoshi; Awaji, Satoshi; Watanabe, Kazuo

    2016-06-01

    A 100 m long six-filament MgB2 wire was successfully fabricated using an internal magnesium diffusion (IMD) process. We investigated the transport properties and the uniformity of this long multifilament IMD wire. The MgB2 layer and the sub-filament region are regular, and the J c values have a fairly homogenous distribution throughout the wire, suggesting that there were no obvious defects along the length of the wire. The uniformity problem of long multifilament IMD MgB2 wires can be mitigated by optimizing the starting composite parameters, multifilament geometry, fabricating process and annealing conditions. A layer J c as high as 1.2 × 105 A cm-2 at 4.2 K and 8 T was obtained, which was comparable with the highest reported value for a short multifilament IMD wire. The transport layer J c, non-barrier J c and J e values are independent of the wire diameter. In addition, the analysis of the stress-strain characteristics and the n value of the IMD wire is also presented. These results indicate that the long multifilament IMD-processed MgB2 superconducting wire is suitable for practical applications.

  15. Self-Healing Technologies for Wiring and Surfaces in Aerospace and Deep Space Exploration Applications

    Science.gov (United States)

    Williams, Martha Kay; Gibson, Tracy L.; Jolley, Scott T.; Caraccio-Meier, Anne Joan

    2017-01-01

    Self-healing technologies have been identified as critical technology gaps for future exploration. NASA and KSC have been working in this area for multiple years with established intellectual property; however, there are many challenges that remain in this area of research. How do we mimic what the body does so naturally when we as NASA have unique requirements? We have been investigating several mechanisms for self-healing: microencapsulation with a healant core to fill in voids in the case of mechanical puncture and flowable (or sealable)systems that have inherent chemical properties that allow the materials to flow back together when cut or damaged. The microcapsules containing healant have to be durable and robust, must be able to take high temperatures to meet NASA unique requirements, provide good capillary flow of the healant, and be small in diameters to fill in damage voids in thin films or surfaces. Sealable systems have to flow in a range of temperatures and yet be lightweight and chemically resistant. The systems currently being developed are based on polyimide and polyurethane matrices and have been studied for use in high performance wiring systems, inflatable systems, and habitation structures. Self-healing or self-sealing capability would significantly reduce maintenance requirements and increase the safety and reliability performance of critical systems. Advances in these self-healing technologies and some of the unique challenges needed to be overcome in order to incorporate a self-healing mechanism into wiring or thin films systems will be addressed.

  16. Mushroom-type structures with the wires connected through diodes: Theory and applications

    Science.gov (United States)

    Forouzmand, Ali; Kaipa, Chandra S. R.; Yakovlev, Alexander B.

    2016-07-01

    In this paper, we establish a general formalism to quantify the interaction of electromagnetic waves with mushroom-type structures (high impedance surface and bi-layer) with diodes inserted along the direction of the wires. The analysis is carried out using the nonlocal homogenization model for the mushroom structure with the generalized additional boundary conditions at the connection of the wires to diodes. We calculate numerically the magnitude and phase of the reflected/transmitted fields in the presence of an ideal and realistic PIN diodes. It is observed that the reflection/transmission characteristics of the mushroom-type structures can be controlled by tuning the working states of the integrated PIN diodes. We realize a structure with a multi-diode switch to minimize the undesired transmission for a particular incident angle. In addition, a dual-band subwavelength imaging lens is designed based on the resonant amplification of evanescent waves, wherein the operating frequency can be tuned by changing the states of the PIN diodes. The analytical results are verified with the full-wave electromagnetic solver CST Microwave Studio, showing a good agreement.

  17. Homogenous BSCCO-2212 Round Wires for Very High Field Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Scott Campbell

    2012-06-30

    The performance demands on modern particle accelerators generate a relentless push towards higher field magnets. In turn, advanced high field magnet development places increased demands on superconducting materials. Nb3Sn conductors have been used to achieve 16 T in a prototype dipole magnet and are thought to have the capability for {approx}18 T for accelerator magnets (primarily dipoles but also higher order multipole magnets). However there have been suggestions and proposals for such magnets higher than 20 T. The High Energy Physics Community (HEP) has identified important new physics opportunities that are enabled by extremely high field magnets: 20 to 50 T solenoids for muon cooling in a muon collider (impact: understanding of neutrinos and dark matter); and 20+ T dipoles and quadrupoles for high energy hadron colliders (impact: discovery reach far beyond present). This proposal addresses the latest SBIR solicitation that calls for grant applications that seek to develop new or improved superconducting wire technologies for magnets that operate at a minimum of 12 Tesla (T) field, with increases up to 15 to 20 T sought in the near future (three to five years). The long-term development of accelerator magnets with fields greater than 20 T will require superconducting wires having significantly better high-field properties than those possessed by current Nb{sub 3}Sn or other A15 based wires. Given the existing materials science base for Bi-2212 wire processing, we believe that Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} (Bi-2212) round wires can be produced in km-long piece lengths with properties suitable to meet both the near term and long term needs of the HEP community. The key advance will be the translation of this materials science base into a robust, high-yield wire technology. While the processing and application of A15 materials have advanced to a much higher level than those of the copper oxide-based, high T{sub c} (HTS) counterparts, the HTS materials have

  18. ORNL Superconducting Technology Program for Electric Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hawsey, R.A. (comp.)

    1993-02-01

    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.

  19. ORNL Superconducting Technology Program for Electric Power Systems, Annual Report for FY 1998

    Energy Technology Data Exchange (ETDEWEB)

    Hawsey, R.A.; Murphy, A.W.

    1999-04-01

    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.

  20. Analysis of mechanical characteristics of superconducting field coil for 17 MW class high temperature superconducting synchronous motor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. H.; Park, S. I.; Im, S. H.; Kim, H. M. [Jeju National University, Jeju (Korea, Republic of)

    2013-09-15

    Superconducting field coils using a high-temperature superconducting (HTS) wires with high current density generate high magnetic field of 2 to 5 [T] and electromagnetic force (Lorentz force) acting on the superconducting field coils also become a very strong from the point of view of a mechanical characteristics. Because mechanical stress caused by these powerful electromagnetic force is one of the factors which worsens the critical current performance and structural characteristics of HTS wire, the mechanical stress analysis should be performed when designing the superconducting field coils. In this paper, as part of structural design of superconducting field coils for 17 MW class superconducting ship propulsion motor, mechanical stress acting on the superconducting field coils was analyzed and structural safety was also determined by the coupling analysis system that is consists of commercial electromagnetic field analysis program and structural analysis program.

  1. 11th International Symposium on Superconductivity(ISS98); Dai 11 kai kokusai chodendo shinpojiumu (ISS '98)

    Energy Technology Data Exchange (ETDEWEB)

    Koshitsuka, Naomi

    1999-01-25

    The 11th international symposium on superconductivity(ISS98) was held at Sunpalace hotel in Fukuoka city for 3 days from 17th to 19th in November 1998. As a total impression, it is felt that the high temperature superconductivity started to apply for the SQUID, the microwave filters and the refrigerating machine cryogenic magnets etc. and that the developments of various equipment progressed by using the Bi wires and the bulk materials of Y type. Prof. Yonezawa gave the first basic lecture regarding not only the superconductivity but also the tendency of 21 century for all fields of science and technology. And he said that the superconductivity might be become the important parts in life science, energy, and the revolution of information which would be become the keywords of 21 century. Another two lectures were given regarding a tendency for development of SQUID and its application. In the afternoon of the first day, 5 speakers gave the basic lectures regarding the electronic applications of superconductivity, the new materials, the critical current, the wire materials of the next generation and the SQF devices. (NEDO)

  2. Superconducting Generators for Airborne Applications and YBCO-Coated Conductors (Preprint)

    Science.gov (United States)

    2008-10-01

    design was a homopolar inductor alternator (HIA) which locates the superconductor coil within the stator, thereby eliminating rotational loads on the...advantages over the BSCCO tape previous used in motor and generator demonstrations. The benefits of compact high- power superconducting machinery

  3. Design study of 10 kW superconducting generator for wind turbine applications

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Mijatovic, Nenad; Seiler, Eugen;

    2009-01-01

    = 1 Tesla to be similar to the performance of permanent magnets and to represent a layout, which can be scaled up in future off-shore wind turbines. The proposed generator is a 8 pole synchronous machine based on race-track coils of high temperature superconducting tapes and an air cored copper stator...

  4. Optimization and comparison of superconducting generator topologies for a 10 MW wind turbine application

    DEFF Research Database (Denmark)

    Liu, Dong; Polinder, Henk; Abrahamsen, Asger Bech

    2017-01-01

    -linear finite element models. By implementing this method, three typical superconducting generator topologies are compared in terms of the active material cost and mass, the synchronous reactance and the phase resistance. The optimization method and the comparison results provide the DDSCG designers...... with a guideline for selecting a suitable machine topology....

  5. Electrodeposition and characterisation of lead tin superconducting films for application in heavy ion booster

    Energy Technology Data Exchange (ETDEWEB)

    Lobanov, Nikolai R., E-mail: Nikolai.Lobanov@anu.edu.au

    2015-12-15

    The ANU has developed experimental systems and procedures for lead–tin (PbSn) film deposition and characterisation. The 12 split loop resonators have been electroplated with 96%Pb4%Sn film to the final thickness of 1.5 micron using methanesulfonic acid (MSA) chemistry. As a result, an average acceleration field of 3.6 MV/m off-line at 6 W rf power was achieved at extremely low technological cost. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Heavy Ion Elastic Detection Analyses (HIERDA), Rutherford Backscattering Spectroscopy (RBS), Secondary Ion Mass Spectroscopy (SIMS) and Electron Backscattering Diffraction (EBSD) revealed correlation between the substrate and film structure, morphology and the rf performance of the cavity. The PbSn plating, exercised on the existing split loop resonators (SLR), has been extended to the two stub quarter wave resonator (QWR) as a straightforward step to quickly explore the superconducting performance of the new geometry. The oxygen free copper (OHFC) substrate for two stub QWR was prepared by reverse pulse electropolishing. The ultimate superconducting properties and long-term stability of the coatings have been assessed by operation of the ANU superconducting linac over the last few years. - Highlights: • PbSn alloy is investigated as a material for superconducting low and medium velocity rf resonators. • It is easily electrodeposited with MSA chemistry at very low cost, has high T{sub c}, and good performance at high fields. • The optimum substrate preparation and coating conditions are established based on examination of the properties of substrate and superconducting films. • A long term stability of the electroplated resonators has been showing no evidence of degradation of the rf properties over the last decade. • The resonators high field performance limiting factors and their possible elimination have been evaluated.

  6. Superconducting switch pack

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, V.C.; Wollan, J.J.

    1990-07-24

    This patent describes a superconducting switch pack at least one switch element. The switch element including a length of superconductive wire having a switching portion and two lead portions, the switching portion being between the lead portions; means for supporting the switching portion in a plane in a common mold; hardened resin means encapsulating the switching portion in the plane in a solid body; wherein the solid body has an exterior surface which is planar and substantially parallel with and spaced apart from the plane in which the switching portion is positioned. The exterior surface being exposed to the exterior of the switch pack and the resin means filling the space between the exterior surface and the plane of the switching portion so as to provide uninterrupted thermal communication between the plane of the switching portion and the exterior of the switch pack; and a heater element in thermal contact with the switching portion.

  7. Overview of superconductivity in Japan Strategy road map and R&D status

    Science.gov (United States)

    Tsukamoto, O.

    2008-09-01

    Superconducting technology benefits society in broad fields; environment/energy, life science, manufacturing industry and information and communication. Superconducting equipments and devices used in various fields are divided into two categories, electric and electronic applications. Technologies in those applications are progressing remarkably owing to firm and consistent supports by various national projects. The final target of the NEDO R&D project of fundamental technology for superconductivity applications to develop 500 m long coated conductors (CCs) of the critical current 300 A/cm (at 77 K, 0 T) will be fulfilled by the end of JFY 2007 and manufacturing process to produce extremely low-cost CCs is to be developed to make the applications realistic. Preliminary works to develop power apparatuses using CCs have started in the frame of the R&D project for the fundamental technology and have produced significant results. Performance of BSCCO/Ag-sheathed wires has been improved greatly and various applications using those wires are being developed. R&D projects for SMES, power cable, flywheel energy storage and rotating machines are going to introduce those equipments to the real world. Technologies of SQUID and SFQ, basic devices of the electronic applications, are progressing dramatically also owing to various national projects. In this back ground the technology strategy map in the field of superconducting technology was formulated to prioritize investments in R&D by clearly defining the objectives and inspire autonomous R&D actives in various fields of industries. R&D activities in the superconducting technologies are to be scheduled following this strategy map.

  8. Self-Assembled Wire Arrays and ITO Contacts for Silicon Nanowire Solar Cell Applications

    Institute of Scientific and Technical Information of China (English)

    YANG Cheng; ZHANG Gang; LEE Dae-Young; LI Hua-Min; LIM Young-Dae; Y00 Won Jong; PARK Young-Jun; KIM Jong-Min

    2011-01-01

    Self-assembly of silicon nanowire(SiNW)arrays is studied using SF6/02 plasma treatment. The self-assembly method can be applied to single- and poly-crystalline Si substrates. Plasma conditions can control the length and diameter of the SiNW arrays. Lower reflectance of the wire arrays over the wavelength range 200-1100nm is obtained. The conducting transparent indium-tin-oxide(ITO) electrode can be fully coated on the self-assembled SiNW arrays by sputtering. The ITO-coated SiNW solar cells show the same low surface light reflectance and a higher carrier collection efficiency than SiNW solar cells without ITO coating. An efficiency enhancement of around 3 times for ITO coated SiNW solar cells is demonstrated via experiments.

  9. Application of Copper-tin Alloy Contact Wires on Electrified Railways%电气化铁路铜锡合金接触线的应用

    Institute of Scientific and Technical Information of China (English)

    陈绍华; 王作祥

    2011-01-01

    阐述了不同等级的铜锡接触线的性能、应用范围;说明了铜锡接触线可以满足所有速度等级电气化铁路以及城市地铁和轨道交通的要求;对铜锡接触线与铜银接触线和铜镁接触线在使用性能、工艺性能和制造成本方面进行了比较。并对铁道部行业标准提出了修订意见。%The paper illustrates the performances and the scope of application of the copper-tin alloy contact wires;states clearly that the copper-tin contact wires are able to satisfy with the requirements of the electrified railways in different speeds,the metro and urban rail transportation;the comparisons are given for the copper-tin contact wires,copper-silver contact wires and copper-magnesium contact wires in terms of the application performance,processing performance and manufacture costs.It also puts forward the proposals on revision of the industrial standards of the Ministry of Railways.

  10. Development of superconductor application technology

    Energy Technology Data Exchange (ETDEWEB)

    Hong, G. W.; Kim, C. J.; Lee, H. G.; Lee, H. J.; Kim, K. B.; Won, D. Y.; Jang, K. I.; Kwon, S. C.; Kim, W. J.; Ji, Y. A.; Yang, S. W.; Kim, W. K.; Park, S. D.; Lee, M. H.; Lee, D. M.; Park, H. W.; Yu, J. K.; Lee, I. S.; Kim, J. J.; Choi, H. S.; Chu, Y.; Kim, Y. S.; Kim, D. H.

    1997-09-01

    Fabrication of high Tc bulk superconductor and its application, fabrication of superconducting wire for electric power device and analysis for cryogenic system were carried out for developing superconductor application technologies for electric power system. High quality YBaCuO bulk superconductor was fabricated by controlling initial powder preparation process and prototype flywheel energy storage device was designed basically. The superconducting levitation force measuring device was made to examine the property of prepared superconductor specimen. Systematic studies onthe method of starting powder preparation, mechanical fabrication process, heat treatment condition and analysis of plastic deformation were carried out to increase the stability and reproducibility of superconducting wire. A starting power with good reactivity and fine particle size was obtained by mechanical grinding, control of phase assemblage, and emulsion drying method. Ag/BSCCO tape with good cross sectional shape and Jc of 20,000 A/cm{sup 2} was fabricated by applying CIP packing procedure. Multifilamentary wire with Jc of 10,000 A/cm{sup 2} was fabricated by rolling method using square billet as starting shape. The joining of the multifilamentary wire was done by etching and pressing process and showed 50% of joining efficiency. Analysis on the heat loss in cryostat for high Tc superconducting device was carried out for optimum design of the future cryogenic system. (author). 66 refs., 104 figs.

  11. Homogenous BSCCO-2212 Round Wires for Very High Field Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Scott Campbell

    2012-06-30

    The performance demands on modern particle accelerators generate a relentless push towards higher field magnets. In turn, advanced high field magnet development places increased demands on superconducting materials. Nb3Sn conductors have been used to achieve 16 T in a prototype dipole magnet and are thought to have the capability for {approx}18 T for accelerator magnets (primarily dipoles but also higher order multipole magnets). However there have been suggestions and proposals for such magnets higher than 20 T. The High Energy Physics Community (HEP) has identified important new physics opportunities that are enabled by extremely high field magnets: 20 to 50 T solenoids for muon cooling in a muon collider (impact: understanding of neutrinos and dark matter); and 20+ T dipoles and quadrupoles for high energy hadron colliders (impact: discovery reach far beyond present). This proposal addresses the latest SBIR solicitation that calls for grant applications that seek to develop new or improved superconducting wire technologies for magnets that operate at a minimum of 12 Tesla (T) field, with increases up to 15 to 20 T sought in the near future (three to five years). The long-term development of accelerator magnets with fields greater than 20 T will require superconducting wires having significantly better high-field properties than those possessed by current Nb{sub 3}Sn or other A15 based wires. Given the existing materials science base for Bi-2212 wire processing, we believe that Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} (Bi-2212) round wires can be produced in km-long piece lengths with properties suitable to meet both the near term and long term needs of the HEP community. The key advance will be the translation of this materials science base into a robust, high-yield wire technology. While the processing and application of A15 materials have advanced to a much higher level than those of the copper oxide-based, high T{sub c} (HTS) counterparts, the HTS materials have

  12. Magnesium Diboride Superconducting Coils for Adiabatic Demagnetization Refrigerators (ADR's) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For Adiabatic Demagnetization Refrigerators(ADR's) for space it is desirable to have very light weight, small diameter, high current density superconducting wires...

  13. ORNL Superconducting Technology Program for Electric Power Systems--Annual Report for FY 2001

    Energy Technology Data Exchange (ETDEWEB)

    Hawsey, RA

    2002-02-18

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy's Office of Energy Efficiency and Renewable Energy to develop the science and technology base needed by US industry for development of electric power applications of high-temperature superconductivity. The two major elements of this program are wire development and applications development. A new part of the wire research effort was the Accelerated Coated Conductor Initiative. 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 2001 Annual Program Review held August 1-3, 2001. Aspects of ORNL's work that were presented at the International Cryogenic Materials Conference/Cryogenic Engineering Conference (July 2001) are included in this report as well. 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. Working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with US 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.

  14. Kinetic inductance measured in a superconducting wire

    Science.gov (United States)

    Meservey, R. H.; Tedrow, P. M.

    1970-01-01

    Ultrasensitive technique to measure kinetic inductance has test specimen included as part of the inductance of a tank circuit of a tunnel diode oscillator. Frequency counter measures shift in frequency of oscillator, caused by changes in inductance. Frequency shift in tank circuit is proportional to change in kinetic inductance

  15. Applied Superconductivity: Amplifiers and Microcomposite Wire

    Science.gov (United States)

    1976-01-01

    breaks down, CO if put in terms of the Bean model of flux penetration, would imply that the critical current density within the copper was...and so cause a field dependent critical current in the copper. Such a critical current, in the Bean model , would account for the change in sign...We can give some support to the Bean model picture of flux penetration in our microcomposites, however. CO We note that using the Bean modelJO to

  16. Proceedings of the fourth international conference and exhibition: World Congress on superconductivity. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-31

    This document contains papers presented at the 4th International Conference Exhibition: World Congress on Superconductivity held at the Marriott Orlando World Center, Orlando, Florida, June 27--July 1, 1994. This conference encompassed research, technology, applications, funding, political, and social aspects of superconductivity. Specifically, the areas of research, technology, and development covered during the conference included high-temperature materials, thin films, C-60 based superconductors, persistent magnetic fields and shielding, fabrication methodology, space applications, physical applications, performance characterization, device applications, weak link effects and flux motion, accelerator technology, superconductivity energy, storage, future research and development directions, medical applications, granular superconductors, wire fabrication technology, computer applications, technical and commercial challenges, and power and energy applications. The key objective of this conference was to provide a forum for the world community to share technological results of recent advances made in the field of superconductivity and to discuss translation of the research to technology which will benefit humanity. More than 150 presentations were made at this conference. Individual papers are indexed separately on the Energy Data Bases.

  17. Surface superconductivity of dirty two-band superconductors: applications to MgB2.

    Science.gov (United States)

    Gorokhov, Denis A

    2005-02-25

    The minimal magnetic field H(c2) destroying superconductivity in the bulk of a superconductor is smaller than the magnetic field H(c3) needed to destroy surface superconductivity if the surface of a superconductor coincides with one of the crystallographic planes and is parallel to the external magnetic field. While for a dirty single-band superconductor the ratio of H(c3) to H(c2) is a universal temperature-independent constant 1.6946, for dirty two-band superconductors this is not the case. I show that in the latter case the interaction of the two bands leads to a novel scenario with the ratio H(c3)/H(c2) varying with temperature and taking values larger and smaller than 1.6946. The results are applied to MgB(2) and compared with recent experiments (A. Rydh, cond-mat/0307445).

  18. Qualification of niobium materials for superconducting radio frequency cavity applications: View of a condensed matter physicist

    Energy Technology Data Exchange (ETDEWEB)

    Roy, S. B., E-mail: sbroy@rrcat.gov.in [Magnetic & Superconducting Materials Section, Materials & Advanced Accelerator Sciences Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Myneni, G. R., E-mail: rao@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, Virginia (United States)

    2015-12-04

    We address the issue of qualifications of the niobium materials to be used for superconducting radio frequency (SCRF) cavity fabrications, from the point of view of a condensed matter physicist/materials scientist. We focus on the particular materials properties of niobium required for the functioning a SCRF cavity, and how to optimize the same properties for the best SCRF cavity performance in a reproducible manner. In this way the niobium materials will not necessarily be characterized by their purity alone, but in terms of those materials properties, which will define the limit of the SCRF cavity performance and also other related material properties, which will help to sustain this best SCRF cavity performance. Furthermore we point out the need of standardization of the post fabrication processing of the niobium-SCRF cavities, which does not impair the optimized superconducting and thermal properties of the starting niobium-materials required for the reproducible performance of the SCRF cavities according to the design values.

  19. Study of Higher Order Modes in Superconducting Accelerating Structures for Linac Applications

    CERN Document Server

    Schuh, Marcel; Welsch, C P

    2011-01-01

    Higher Order Modes (HOMs) can severely limit the operation of superconducting cavities in a linear accelerator with high beam current, high duty factor and complex pulse structure. Therefore, the full HOM spectrum has to be analysed in detail to identify potentially dangerous modes already during the design phase and to define their damping requirements. For this purpose a dedicated beam dynamics simulation code, Simulation of higher order Mode Dynamics (SMD), focusing on beam-HOM interaction, has been developed in the frame of this project. SMD allows to analyse the beam behaviour under the presence of HOMs, taking into account many important effects, such as for example the HOM frequency spread, beam input jitter, different chopping patterns, as well as klystron and alignment errors. SMD is used to investigate in detail into the effects of HOMs in the Superconducting Proton Linac (SPL) at CERN and in particular their potential to drive beam instabili- ties in the longitudinal and transverse direction. Based...

  20. SCUBA-2 instrument: an application of large-format superconducting bolometer arrays for submillimetre astronomy

    Science.gov (United States)

    Hollister, Matthew Ian

    2009-01-01

    This thesis concerns technical aspects related to the design and operation of the submillimetre common-user bolometer array 2 (SCUBA-2) instrument, a new wide-field camera for submillimetre astronomy currently undergoing commissioning on the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. Offering unprecedented sensitivity and mapping capabilities, SCUBA-2 is expected to make a major impact in surveys of the sky at submillimetre wavelengths, a largely unexplored part of the electromagnetic spectrum, and provide better understanding of the formation and evolution of galaxies, stars and planets by providing large, unbiased samples of such objects. SCUBA-2 uses large arrays of bolometers, with superconducting transition edge sensors (TESs) as the temperature-sensitive element. TES devices are a relatively new technology, utilising the sharp resistance change between the normal and superconducting states to make a sensitive thermistor. Kilopixel arrays of such devices are multiplexed using superconducting quantum interference devices (SQUIDs). This thesis derives the key detector performance parameters, and presents analysis of engineering data to confirm the detector performance on array scales. A key issue for bolometric instruments for far infrared and submillimetre astronomy is the need to operate at extremely low temperatures in the sub-kelvin and millikelvin ranges to achieve the necessary detector sensitivity. This work describes the design, testing and performance of the liquid cryogen-free millikelvin cryostat, the first such instrument to be deployed for astronomy. Subsequent chapters detail the design and testing of a magnetic shielding scheme for the instrument, an important aspect of the operation of superconducting devices. Based on experience with the construction and testing of this instrument, a number of potential improvements for future instruments are presented and discussed.

  1. Models of high-Tc superconductivity and applications to electric generators and motors

    DEFF Research Database (Denmark)

    Sørensen, Mads Peter

    We present the Ginzburg Landau model for mesoscopic high-Tc superconductors of complex geometry. It is shown that giant vortices can form at boundary defects. The relation between total magnetic flux penetration through the superconductor and the externally applied field is established. This is i....... This is in turn used in modelling high-Tc superconducting generators proposed for windmills in the project SuperWind (http://www.superwind.dk)....

  2. Superconducting/magnetic Three-state Nanodevice for Memory and Reading Applications.

    Science.gov (United States)

    del Valle, J; Gomez, A; Gonzalez, E M; Osorio, M R; Granados, D; Vicent, J L

    2015-10-15

    We present a simple nanodevice that can operate in two modes: i) non-volatile three-state memory and ii) reading device. The nanodevice can retain three well defined states -1, 0 and +1 and can operate in a second mode as a sensor for external magnetic fields. The nanodevice is fabricated with an array of ordered triangular-shaped nanomagnets embedded in a superconducting thin film gown on Si substrates. The device runs based on the combination of superconducting vortex ratchet effect (superconducting film) with the out of plane magnetization (nanomagnets). The input signals are ac currents and the output signal are dc voltages. The memory mode is realized without applying a magnetic field and the nanomagnet stray magnetic fields govern the effect. In the sensor mode an external magnetic field is applied. The main characteristic of this mode is that the output signal is null for a precise value of the external magnetic field that only depends on the fabrication characteristics of the nanodevice.

  3. BSCCO超导带材的工艺要点与应用%Technology Essentials and Application of BSCCO Superconducting Tape

    Institute of Scientific and Technical Information of China (English)

    王醒东

    2014-01-01

    高温超导材料的发现,推进了超导技术的实用化。作为典型的高温超导材料,铋系(BSCCO)超导带材目前已在超导电缆、超导限流器和超导储能等领域实现商用。粉末套管法是制备BSCCO超导带材最常用的方法,主要工艺步骤包括装粉、拉拔、轧制和热处理等。本文介绍了粉末套管法的工艺,重点介绍了各工艺步骤中的关键点,阐述了超导带材在超导限流器和超导储能系统中的应用,提出了BSCCO超导带材未来的发展方向。%The discovery of high temperature superconducting(HTS) materials promotes the practical application of superconducting technology. As typical HTS materials, Bi-superconducting tapes(BSCCO) have achieved the commercialization and been applied in superconducting cables, superconducting fault current limiter(SFCL) and superconducting magnetic energy storage(SMES). Powder in tube(PIT) is the most commonly method, which includes some important processing steps such as powder-filling, drawing, rolling and heat treatment. PIT is introduced in this paper, especially the key point in each process step. The application of superconducting tapes in SFCL and SMES is expounded. Finally, the future development direction of BSCCO superconductor tape is indicated.

  4. Story of Superconductivity: A Serendipitous Discovery

    Indian Academy of Sciences (India)

    Amit Roy

    2017-05-01

    Electricity is carried through metallic wires, called conductors.In the process, electrons move through metallic conductorsthat offer resistance (the value depends on the particularmetal used), to the passage of electrons. This leads to the productionof heat and loss of energy. This heating process isutilised in many electrical devices. However, for transmissionof electrical energy from the power plants to the user and inmany other applications, it would be a great boon if no energywas lost to resistance. The discovery of superconductivity byHeike Kamerlingh Onnes in 1911 at Leiden, offered a glimmerof hope to make this dream possible. It was a discoverytotally unexpected at that time, and we owe this discovery tothe painstaking andmethodical investigations of Onnes – firstto produce very low temperatures, and then measure propertiesof materials at these freezing temperatures.

  5. Developing a high-temperature superconducting bulk magnet for the maglev train of the future

    Science.gov (United States)

    Fujimoto, Hiroyuki

    1998-10-01

    The major applications of high-temperature superconductors have mostly been confined to products in the form of wires and thin films. However, recent developments show that rare-earth REBa2Cu3O7-x and light rare-earth LREBa2Cu3O7-3 superconductors prepared by melt processes have a high critical-current density at 77 K and high magnetic fields. These superconductors will promote the application of bulk high-temperature superconductors in high magnetic fields; the superconducting bulk magnet for the Maglev train is one possible application.

  6. High-temperature superconducting conductors and cables

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.E.; Maley, M.P.; Boulaevskii, L.; Willis, J.O.; Coulter, J.Y.; Ullmann, J.L.; Cho, Jin; Fleshler, S.

    1996-09-01

    This is the final report of a 3-year LDRD project at LANL. High-temperature superconductivity (HTS) promises more efficient and powerful electrical devices such as motors, generators, and power transmission cables; however this depends on developing HTS conductors that sustain high current densities J{sub c} in high magnetic fields at temperatures near liq. N2`s bp. Our early work concentrated on Cu oxides but at present, long wire and tape conductors can be best made from BSCCO compounds with high J{sub c} at low temperatures, but which are degraded severely at temperatures of interest. This problem is associated with thermally activated motion of magnetic flux lines in BSCCO. Reducing these dc losses at higher temperatures will require a high density of microscopic defects that will pin flux lines and inhibit their motion. Recently it was shown that optimum defects can be produced by small tracks formed by passage of energetic heavy ions. Such defects result when Bi is bombarded with high energy protons. The longer range of protons in matter suggests the possibility of application to tape conductors. AC losses are a major limitation in many applications of superconductivity such as power transmission. The improved pinning of flux lines reduces ac losses, but optimization also involves other factors. Measuring and characterizing these losses with respect to material parameters and conductor design is essential to successful development of ac devices.

  7. ASC 84: applied superconductivity conference. Final program and abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    Abstracts are given of presentations covering: superconducting device fabrication; applications of rf superconductivity; conductor stability and losses; detectors and signal processing; fusion magnets; A15 and Nb-Ti conductors; stability, losses, and various conductors; SQUID applications; new applications of superconductivity; advanced conductor materials; high energy physics applications of superconductivity; electronic materials and characterization; general superconducting electronics; ac machinery and new applications; digital devices; fusion and other large scale applications; in-situ and powder process conductors; ac applications; synthesis, properties, and characterization of conductors; superconducting microelectronics. (LEW)

  8. Evanescent states and nonequilibrium in driven superconducting nanowires

    NARCIS (Netherlands)

    Vercruyssen, N.; Verhagen, T.G.A.; Flokstra, M.G.; Pekola, J.P.; Klapwijk, T.M.

    2012-01-01

    We study the nonlinear response of current transport in a superconducting diffusive nanowire between normal reservoirs. We demonstrate theoretically and experimentally the existence of two different superconducting states appearing when the wire is driven out of equilibrium by an applied bias, calle

  9. State of the art of superconducting fault current limiters and their application to the electric power system

    Science.gov (United States)

    Morandi, Antonio

    2013-01-01

    Modern electric power systems are becoming more and more complex in order to meet new needs. Nowadays a high power quality is mandatory and there is the need to integrate increasing amounts of on-site generation. All this translates in more sophisticated electric network with intrinsically high short circuit rate. This network is vulnerable in case of fault and special protection apparatus and procedures needs to be developed in order to avoid costly or even irreversible damage. A superconducting fault current limiter (SFCL) is a device with a negligible impedance in normal operating conditions that reliably switches to a high impedance state in case of extra-current. Such a device is able to increase the short circuit power of an electric network and to contemporarily eliminate the hazard during the fault. It can be regarded as a key component for future electric power systems. In this paper the state of the art of superconducting fault current limiters mature for applications is briefly resumed and the potential impact of this device on the paradigm of design and operation of power systems is analyzed. In particular the use of the FCL as a mean to allow more interconnection of MV bus-bars as well an increased immunity with respect to the voltage disturbances induced by critical customer is discussed. The possibility to integrate more distributed generation in the distribution grid is also considered.

  10. Superconducting Technology Assessment

    Science.gov (United States)

    2005-08-01

    of Nb/Al- Nx /NbTiN junctions for SIS mixer applications,” IEEE Trans. Appl. Superconduct., vol. 11, pp. 76–79, Mar. 2001. [48] M. Gurvitch, W. A...Another connector developed by IBM for commercial applications using a dendritic interposer technology. A “beam-on-pad” approach developed by Siemens

  11. APPLICATION OF THE X-RAY STRUCTURE ANALYSIS FOR IMPROVEMENT OF TECHNOLOGICAL PROCES- SES OF WIRE PRODUCTION AT BMZ

    Directory of Open Access Journals (Sweden)

    D. V. Kuznetsov

    2012-01-01

    Full Text Available The X-ray diffraction methods of qualitative and quantative analysis of phase composition of the brass coating, scale on the surface of brass wire, rod, patented wire, methods of determining the characteristics of the microstrains the lattice ferritic matrix pearlitic high-carbon steel, are explored.

  12. Cantilever anemometer based on a superconducting micro-resonator: application to superfluid turbulence.

    Science.gov (United States)

    Salort, J; Monfardini, A; Roche, P-E

    2012-12-01

    We present a new type of cryogenic local velocity probe that operates in liquid helium (1 K < T < 4.2 K) and achieves a spatial resolution of ≈ 0.1 mm. The operating principle is based on the deflection of a micro-machined silicon cantilever which reflects the local fluid velocity. Deflection is probed using a superconducting niobium micro-resonator sputtered on the sensor and used as a strain gauge. We present the working principle and the design of the probe, as well as calibration measurements and velocity spectra obtained in a turbulent helium flow above and below the superfluid transition.

  13. High temperature interfacial superconductivity

    Science.gov (United States)

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

    2012-06-19

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

  14. Correlation of acoustic emission with normal zone occurrence in epoxy-impregnated windings: An application of acoustic emission diagnostic technique to pulse superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tsukamoto, O.; Iwasa, Y.

    1984-05-01

    We report results of experiments correlating acoustic emission (AE) data to the presence of normal zones in epoxy-impregnated windings. The results suggest the feasibility of using AE sensors to determine whether or not a superconducting magnet has been driven normal after a rapid discharge. This AE diagnostic technique may be particularly valuable in application to pulse magnets.

  15. Magnetic characterization of the nickel layer protecting the copper wires in harsh applications

    National Research Council Canada - National Science Library

    Roger Daniel; Duchesne Stephane; Iosif Vadim

    2017-01-01

    High Temperature (HT°) motor coils open new perspectives for extending the applications of electrical motors or generators to very harsh environments or for designing very high power density machines working with high...

  16. Analysis of Nb{sub 3}Sn surface layers for superconducting radio frequency cavity applications

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Chaoyue [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Posen, Sam; Hall, Daniel Leslie [Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York 14853 (United States); Groll, Nickolas; Proslier, Thomas, E-mail: prolier@anl.gov [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Cook, Russell [Nanoscience and Technology Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Schlepütz, Christian M. [X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Liepe, Matthias [Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York 14853 (United States); Department of Physics, Cornell University, Ithaca, New York 14853 (United States); Pellin, Michael [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Zasadzinski, John [Department of Physics, Illinois Institute of Technology, Chicago, Illinois 60616 (United States)

    2015-02-23

    We present an analysis of Nb{sub 3}Sn surface layers grown on a bulk Niobium (Nb) coupon prepared at the same time and by the same vapor diffusion process used to make Nb{sub 3}Sn coatings on 1.3 GHz Nb cavities. Tunneling spectroscopy reveals a well-developed, homogeneous superconducting density of states at the surface with a gap value distribution centered around 2.7 ± 0.4 meV and superconducting critical temperatures (T{sub c}) up to 16.3 K. Scanning transmission electron microscopy performed on cross sections of the sample's surface region shows an ∼2 μm thick Nb{sub 3}Sn surface layer. The elemental composition map exhibits a Nb:Sn ratio of 3:1 and reveals the presence of buried sub-stoichiometric regions that have a ratio of 5:1. Synchrotron x-ray diffraction experiments indicate a polycrystalline Nb{sub 3}Sn film and confirm the presence of Nb rich regions that occupy about a third of the coating volume. These low T{sub c} regions could play an important role in the dissipation mechanisms occurring during RF tests of Nb{sub 3}Sn-coated Nb cavities and open the way for further improving a very promising alternative to pure Nb cavities for particle accelerators.

  17. Characterization of superconducting nanometric multilayer samples for SRF applications: first evidence of magnetic screening effect

    CERN Document Server

    Antoine, C Z; Bouat, S; Jacquot, J-F; Villegier, J-C; Lamura, G; Gurevich, A

    2010-01-01

    Best rf bulk niobium accelerating cavities have nearly reached their ultimate limits at rf equatorial magnetic field H ~ 200 mT close to the thermodynamic critical field Hc. In 2006 Gurevich proposed to use nanoscale layers of superconducting materials with high values of Hc > HcNb for magnetic shielding of bulk niobium to increase the breakdown magnetic field of SC rf cavities 1. Depositing good quality layers inside a whole cavity is rather difficult So as a first step, characterization of single layer coating and multilayers was conducted on high quality sputtered samples by applying the technique used for the preparation of superconducting electronics circuits. The samples were characterized by X-ray reflectivity, dc resistivity (PPMS) and dc magnetization (SQUID) measurements. Dc magnetization curves of a 250 nm thick Nb film have been measured, with and without a magnetron sputtered coating of a single or multiple stack of 15 nm MgO and 25 nm NbN layers. The Nb samples with/without the coatin...

  18. Heat Load Measurements on a Large Superconducting Magnet An Application of a Void Fraction Meter

    CERN Document Server

    Pengo, R; Junker, S; Passardi, Giorgio; ten Kate, H H J

    2004-01-01

    ATLAS is one of the two major experiments of the LHC project at CERN using cryogenics. The superconducting magnet system of ATLAS is composed of the Barrel Toroid (BT), two End Caps Toroids and the Central Solenoid. The BT is formed of 8 race-track superconducting dipoles, each one 25 m long and 5 m wide. A reduced scale prototype (named B0) of one of the 8 dipoles, about one third of the length, has been constructed and tested in a dedicated cryogenic facility at CERN. To simulate the final thermal and hydraulic operating conditions, the B0 was cooled by a forced flow of 4.5 K saturated liquid helium provided by a centrifugal pump of 80 g/s nominal capacity. Both static and dynamic heat loads, generated by the induced currents on the B0 casing during a slow dump or a ramp up, have been measured to verify the expected thermal budget of the entire BT. The instrument used for the heat load measurements was a Void Fraction Meter (VFM) installed on the magnet return line. The instrument constructed at CERN was ca...

  19. Preliminary investigation of force-reduced superconducting magnet configurations for advanced technology applications

    Energy Technology Data Exchange (ETDEWEB)

    Bouillard, J.X.

    1992-12-01

    The feasibility of new high-field low specific weight superconducting magnet designs using force-free fields is being explored analytically and numerically. This report attempts to assess the technical viability of force-free field concepts to produce high-field, low specific weight and large bore volume magnets, which could promote the use of high temperature superconductors. Several force-free/force-reduced magnet configurations are first reviewed, then discussed and assessed. Force-free magnetic fields, fields for which the current flows parallel to the field, have well-known mathematical solutions extending upon infinite domains. These solutions, however, are no longer force-free everywhere for finite geometries. In this preliminary study, force-free solutions such as the Lundquist solutions truncated to a size where the internal field of the coil matches an externally cylindrical magnetic field (also called a Lundquist coil) are numerically modeled and explored. Significant force-reduction for such coils was calculated, which may have some importance for the design of lighter toroidal magnets used in thermonuclear fusion power generation, superconducting magnetic energy storage (SMES), and mobile MHD power generation and propulsion.

  20. Proximity effect-induced superconducting networks

    Science.gov (United States)

    Tsuchiya, S.; Tanda, S.

    2009-02-01

    We have studied proximity effect-induced superconductivity of micro wire networks in a magnetic field for investigating topological effects of the superconducting order parameter through Little-Parks oscillation. We prepared a regular honeycomb network, which has Pb-Au bilayer structure, by standard electron beam lithography and measured variation of superconducting transition temperature (Tc) in a magnetic field. We also fabricated a honeycomb network made of Pb monolayer and measured it in the same way. In the experimental results of the monolayer network, 2.06 ± 0.02 Gauss of periodic variation of Tc in a magnetic field was observed at around 7.2 K. The area estimated from this period is 10.04 μm2 and correspond to unit honeycomb enclosed by center of the wire. While, in the results of the bilayer network, 2.66 ± 0.04 Gauss of periodic variation of Tc in a magnetic field was observed at around 4.3 K because of the proximity effect. The area estimated from this period is 7.78 μm2 and correspond to unit honeycomb enclosed by edge of the wire. In the latter case, the superconducting current flows through edge of the wire since the order parameter can be considered to be more developed and inhomogeneous on the wire cross-section at around 4.3 K less than 7.2 K. Consequently, a novel network of paths flowing through the superconducting current, which consists of loops enclosed by edge of the wire, can be realized by controlling the proximity effect.

  1. Development of density-functional theory for a plasmon-assisted superconducting state: application to lithium under high pressures.

    Science.gov (United States)

    Akashi, Ryosuke; Arita, Ryotaro

    2013-08-02

    We extend the density-functional theory for superconductors (SCDFT) to take account of the dynamical structure of the screened Coulomb interaction. We construct an exchange-correlation kernel in the SCDFT gap equation on the basis of the random-phase approximation, where electronic collective excitations such as plasmons are properly treated. Through an application to fcc lithium under high pressures, we demonstrate that our new kernel gives higher transition temperatures (T(c)) when the plasmon and phonon cooperatively mediate pairing and it improves the agreement between the calculated and experimentally observed T(c). The present formalism opens the door to nonempirical studies on unconventional electron mechanisms of superconductivity based on density-functional theory.

  2. Development of superconductor application technology - Fabrication of superconducting plate using tape casting and development of directional growth

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Kwang Soo; Yoon, Dae Sung; Lee, Joon Sung; Jun, Byung Hyuk; Woo, Sung Soo; Hong, Seung Bum; Kim, Eun Ah; Song, Han Wook [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1996-05-01

    This study concerns the establishment of the fabrication techniques of the high temperature superconductor tape using tape coating, the heat treatment and directional growth techniques in order to fabricate high temperature superconductor bulks having high current density. This study is important in the development of bulk high temperature superconductors and in the applications in bulk forms. Development of Tape Casting Technique : Fabrication of the high temperature superconductor tape using different processing condition. Fabrication of Y- and Bi- High Temperature Superconductor Tapes : Based on the optimum processing condition, the superconductor tapes were fabricated. Development of Directional Growth Techniques : The tapes were heat-treated at proper condition and directionally growth using different directional growth condition. The superconducting properties were tested on the directionally grown samples. 21 figs. (author)

  3. A Cryogenic Magnetostrictive Actuator using a Persistent High Temperature Superconducting Magnet, Part 1: Concept and Design. Part 1; Concept and Design

    Science.gov (United States)

    Horner, Garnett C.; Bromberg, Leslie; Teter, J. P.

    2001-01-01

    Cryogenic magnetostrictive materials, such as rare earth zinc crystals, offer high strains and high forces with minimally applied magnetic fields, making the material ideally suited for deformable optics applications. For cryogenic temperature applications, such as Next Generation Space Telescope (NGST), the use of superconducting magnets offer the possibility of a persistent mode of operation, i.e., the magnetostrictive material will maintain a strain field without power. High temperature superconductors (HTS) are attractive options if the temperature of operation is higher than 10 degrees Kelvin (K) and below 77 K. However, HTS wires have constraints that limit the minimum radius of winding, and even if good wires can be produced, the technology for joining superconducting wires does not exist. In this paper, the design and capabilities of a rare earth zinc magnetostrictive actuator using bulk HTS is described. Bulk superconductors can be fabricated in the sizes required with excellent superconducting properties. Equivalent permanent magnets, made with this inexpensive material, are persistent, do not require a persistent switch as in HTS wires, and can be made very small. These devices are charged using a technique which is similar to the one used for charging permanent magnets, e.g., by driving them into saturation. A small normal conducting coil can be used for charging or discharging. Very fast charging and discharging of HTS tubes, as short as 100 microseconds, has been demonstrated. Because of the magnetic field capability of the superconductor material, a very small amount of superconducting magnet material is needed to actuate the rare earth zinc. In this paper, several designs of actuators using YBCO and BSCCO 2212 superconducting materials are presented. Designs that include magnetic shielding to prevent interaction between adjacent actuators will also be described. Preliminary experimental results and comparison with theory for BSSCO 2212 with a

  4. Evanescent states and nonequilibrium in driven superconducting nanowires

    Science.gov (United States)

    Vercruyssen, N.; Verhagen, T. G. A.; Flokstra, M. G.; Pekola, J. P.; Klapwijk, T. M.

    2012-06-01

    We study the nonlinear response of current transport in a superconducting diffusive nanowire between normal reservoirs. We demonstrate theoretically and experimentally the existence of two different superconducting states appearing when the wire is driven out of equilibrium by an applied bias, called the global and bimodal superconducting states. The different states are identified by using two-probe measurements of the wire, and measurements of the local density of states with tunneling probes. The analysis is performed within the framework of the quasiclassical kinetic equations for diffusive superconductors.

  5. Large critical current density improvement in Bi-2212 wires through the groove-rolling process

    Science.gov (United States)

    Malagoli, A.; Bernini, C.; Braccini, V.; Romano, G.; Putti, M.; Chaud, X.; Debray, F.

    2013-04-01

    Recently there has been a growing interest in Bi-2212 superconductor round wire for high magnetic field use despite the fact that an increase of the critical current is still needed to boost its successful use in such applications. Recent studies have demonstrated that the main obstacle to current flow, especially in long wires, is the residual porosity inside these powder-in-tube processed conductors that develops from bubble agglomeration when the Bi-2212 melts. In this work we tried to overcome this issue affecting the wire densification by changing the deformation process. Here we show the effects of groove rolling versus the drawing process on the critical current density JC and on the microstructure. In particular, groove-rolled multifilamentary wires show a JC increased by a factor of about 3 with respect to drawn wires prepared with the same Bi-2212 powder and architecture. We think that this approach in the deformation process is able to produce the required improvements both because the superconducting properties are enhanced and because it makes the fabrication process faster and cheaper.

  6. High Temperature Superconducting Underground Cable

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, Roger, A.

    2010-02-28

    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.

  7. A sourcebook of titanium alloy superconductivity

    CERN Document Server

    Collings, E W

    1983-01-01

    In less than two decades the concept of supercon­ In every field of science there are one or two ductivity has been transformed from a laboratory individuals whose dedication, combined with an innate curiosity to usable large-scale applications. In the understanding, permits them to be able to grasp, late 1960's the concept of filamentary stabilization condense, and explain to the rest of us what that released the usefulness of zero resistance into the field is all about. For the field of titanium alloy marketplace, and the economic forces that drive tech­ superconductivity, such an individual is Ted Collings. nology soon focused on niobium-titanium alloys. They His background as a metallurgist has perhaps given him are ductile and thus fabricable into practical super­ a distinct advantage in understanding superconduc­ conducting wires that have the critical currents and tivity in titanium alloys because the optimization of fields necessary for large-scale devices. More than superconducting parameters in ...

  8. Left-handed compact MIMO antenna array based on wire spiral resonator for 5-GHz wireless applications

    Science.gov (United States)

    Alqadami, Abdulrahman Shueai Mohsen; Jamlos, Mohd Faizal; Soh, Ping Jack; Rahim, Sharul Kamal Abdul; Narbudowicz, Adam

    2017-01-01

    A compact coplanar waveguide-fed multiple-input multiple-output antenna array based on the left-handed wire loaded spiral resonators (SR) is presented. The proposed antenna consists of a 2 × 2 wire SR with two symmetrical microstrip feed lines, each line exciting a 1 × 2 wire SR. Left-handed metamaterial unit cells are placed on its reverse side and arranged in a 2 × 3 array. A reflection coefficient of less than -16 dB and mutual coupling of less than -28 dB are achieved at 5.15 GHz WLAN band.

  9. Minimization and Mitigation of Wire EDM Cutting Errors in the Application of the Contour Method of Residual Stress Measurement

    Science.gov (United States)

    Ahmad, Bilal; Fitzpatrick, Michael E.

    2016-01-01

    The contour method of residual stress measurement relies on the careful application of wire electro-discharge machining (WEDM) for the cutting stage. Changes in material removal rates during the cut lead to errors in the final calculated values of residual stress. In this study, WEDM cutting parameters have been explored to identify the optimum conditions for contour method residual stress measurements. The influence of machine parameters on the surface roughness and cutting artifacts in the contour cut is discussed. It has been identified that the critical parameter in improving the surface finish is the spark pulse duration. A typical cutting artifact and its impact on measured stress values have been identified and demonstrated for a contour cut in a welded marine steel. A procedure is presented to correct contour displacement data from the influence of WEDM cutting artifacts, and is demonstrated on the correction of a measured weld residual stress. The corrected contour method improved the residual stress magnitude up to 150 MPa. The corrected contour method results were validated by X-ray diffraction, incremental center hole drilling, and neutron diffraction.

  10. Transport in Ionic Liquid Gated and Superconducting Nanostructures

    Science.gov (United States)

    Bretz-Sullivan, Terence Michael

    Electrons, when subjected to low temperatures and to very short length scales, exhibit an array of unique quantum mechanical properties. In order to access this regime, one needs cryogenic measurement and nanofabrication techniques. Both experiments in this thesis, which were performed on nanoscale devices, used a 3H e cryostat to access low temperatures, and electron beam lithography to fabricate the devices. The first experiment focused on electron tunneling and transport in ionic liquid gated narrow channels (nanowires) of strontium titanate while the second experiment focused on transport in superconducting aluminum nanowires and magnetic field tuned reentrant superconductivity. Measurements of the current-voltage (I - V) characteristics of ionic liquid gated nanometer scale channels of strontium titanate have been carried out. At low gate voltages, the I - V characteristics exhibited a large voltage threshold for conduction and a nonlinear power law behavior at all temperatures measured. The source-drain current of these nanowires scaled as a power law of the difference between the source-drain voltage and the threshold voltage. The scaling behavior of the I - V characteristic is reminiscent of collective electronic transport through an array of quantum dots. At large gate voltages, the narrow channel acts as a quasi-1D wire whose conductance follows Landauer's formula for multichannel transport. Reenterant superconductivity in quasi-one dimensional superconductors, through the application of a magnetic field, is a counter-intuitive phenomenon. It was not until recently that a microscopic mechanism describing the phenomenon was developed in which superconductivity and phase slip driven dissipation coexist in a non-equilibrium state. Here we present new results on magnetic field induced reentrance to superconductivity in quasi-1D aluminum nanowires for in-plane magnetic fields both transverse to and longitudinal along the wire axis. Measurements in the

  11. Wire Chamber

    CERN Multimedia

    1986-01-01

    Two wire chambers made originally for the R807 Experiment at CERN's Intersecting Storage Rings. In 1986 they were used for the PS 201 experiment (Obelix Experiment) at LEAR, the Low Energy Antiproton Ring. The group of researchers from Turin, using the chambers at that time, changed the acquisition system using for the first time 8 bit (10 bit non linear) analog to digital conversion for incoming signals from the chambers. The acquisition system was controlled by 54 CPU and 80 digital signal processors. The power required for all the electronics was 40 kW. For the period, this system was one of the most powerful on-line apparatus in the world. The Obelix Experiment was closed in 1996. To find more about how a wire chamber works, see the description for object CERN-OBJ-DE-038.

  12. Application of FPGA technology for control of superconducting TESLA cavities in free electron laser

    Science.gov (United States)

    Pozniak, Krzysztof T.

    2006-10-01

    Contemporary fundamental research in physics, biology, chemistry, pharmacology, material technology and other uses frequently methods basing on collision of high energy particles or penetration of matter with ultra-short electromagnetic waves. Kinetic energy of involved particles, considerably greater than GeV, is generated in accelerators of unique construction. The paper presents a digest of working principles of accelerators. There are characterized research methods which use accelerators. A method to stabilize the accelerating EM field in superconducting (SC) resonant cavity was presented. An example was given of usage of TESLA cavities in linear accelerator propelling the FLASH free electron laser (FEL) in DESY, Hamburg. Electronic and photonic control system was debated. The system bases on advanced FPGA circuits and cooperating fast DSP microprocessor chips. Examples of practical solutions were described. Test results of the debated systems in the real-time conditions were given.

  13. Surface Impedance Measurements of Single Crystal MgB2 Films for Radiofrequency Superconductivity Applications

    Energy Technology Data Exchange (ETDEWEB)

    Binping Xiao, Xin Zhao, Joshua Spradlin, Charles Reece, Michael Kelley, Teng Tan, Xi Xiaoxing

    2012-07-01

    We report microstructure analyses and superconducting radiofrequency (SRF) measurements of large scale epitaxial MgB{sub 2} films. MgB{sub 2} films on 5 cm dia. sapphire disks were fabricated by a Hybrid Physical Chemical Vapor Deposition (HPCVD) technique. The electron-beam backscattering diffraction (EBSD) results suggest that the film is a single crystal complying with a MgB{sub 2}(0001) {parallel} Al{sub 2}O{sub 3}(0001) epitaxial relationship. The SRF properties of different film thicknesses (200 nm and 350 nm) were evaluated under different temperatures and applied fields at 7.4 GHz. A surface resistance of 9 {+-} 2 {mu}{Omega} has been observed at 2.2 K.

  14. Superconducting Gravimeter Data for the IRIS Seismology Database: Application to Normal Modes from the Sumatra Earthquake

    Science.gov (United States)

    Crossley, D.; Rivera, L.; Hinderer, J.; Rosat, S.

    2009-04-01

    For several years, it has been the goal of the Global Geodynamics Project (GGP) to convert high rate acceleration data recorded on superconducting gravimeters (SG) to a format compatible with the seismic data archived at IRIS. The problem for the GGP community has been to properly establish the metadata for characterizing the response of the instrument, particularly its phase characteristics. Although SG data exists at IRIS from the Membach GGP station in Belgium, up to now most of the data from the GGP network has been on hold until the response problem was solved. This we have now been able to do, and we hope to show that data from the Strasbourg SG station will be at IRIS and available. We will also upload all the data from the SGs from after the Sumatra earthquake and show some results on normal mode analysis that demonstrates the benefit of the good amplitude calibration feature and high precision of the SG instruments.

  15. THELMA code electromagnetic model of ITER superconducting cables and application to the ENEA stability experiment

    Science.gov (United States)

    Ciotti, M.; Nijhuis, A.; Ribani, P. L.; Savoldi Richard, L.; Zanino, R.

    2006-10-01

    The new THELMA code, including a thermal-hydraulic (TH) and an electro-magnetic (EM) model of a cable-in-conduit conductor (CICC), has been developed. The TH model is at this stage relatively conventional, with two fluid components (He flowing in the annular cable region and He flowing in the central channel) being particular to the CICC of the International Thermonuclear Experimental Reactor (ITER), and two solid components (superconducting strands and jacket/conduit). In contrast, the EM model is novel and will be presented here in full detail. The results obtained from this first version of the code are compared with experimental results from pulsed tests of the ENEA stability experiment (ESE), showing good agreement between computed and measured deposited energy and subsequent temperature increase.

  16. Experimental study on natural circulation using liquid nitrogen for superconducting applications

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yeon Suk [Korea Basic Science Institute, Daejeon(Korea, Republic of)

    2013-09-15

    An experiment to investigate the natural circulation of a cryogen has been performed. The study is motivated mainly by our recent development of cryogenic cooling system for prototype superconducting cyclotron without any circulating pump. In the natural circulation loop system, a cooling channel is attached on the outer surface of the aluminium block and the liquid nitrogen passes through inside of the channel to cool the block indirectly. A cryocooler as a heat sink is located at the top to re-condense cryogenic vapor coming from the aluminium block in which electrical heater is installed as a heat source. The main dimensions are determined using the relevant analysis and the natural circulation loop is successfully fabricated. The temperature distributions in the loop are measured during initial cool-down process and in steady state, from which the modified Grashof numbers are calculated and compared with the existing correlation estimated with one-dimensional analysis for steady state flow.

  17. Laser polishing of niobium for superconducting radio-frequency accelerator applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Liang [William and Mary College; Klopf, John M. [William and Mary College; Reece, Charles E. [JLAB; Kelley, Michael J. [JLAB

    2014-08-01

    Interior surfaces of niobium cavities used in superconducting radio frequency accelerators are now obtained by buffered chemical polish and/or electropolish. Laser polishing is a potential alternative, having advantages of speed, freedom from noxious chemistry and availability of in-process inspection. We studied the influence of the laser power density and laser beam raster rate on the surface topography. These two factors need to be combined carefully to smooth the surface without damage. Computational modeling was used to estimate the surface temperature and gain insight into the mechanism of laser polishing. Power spectral density analysis of surface topography measurements shows that laser polishing can produce smooth topography similar to that obtained by electropolish. This is a necessary first step toward introducing laser polishing as an alternative to the currently practiced chemical polishing.

  18. A study on the required performance of a 2G HTS wire for HTS wind power generators

    Science.gov (United States)

    Sung, Hae-Jin; Park, Minwon; Go, Byeong-Soo; Yu, In-Keun

    2016-05-01

    YBCO or REBCO coated conductor (2G) materials are developed for their superior performance at high magnetic field and temperature. Power system applications based on high temperature superconducting (HTS) 2G wire technology are attracting attention, including large-scale wind power generators. In particular, to solve problems associated with the foundations and mechanical structure of offshore wind turbines, due to the large diameter and heavy weight of the generator, an HTS generator is suggested as one of the key technologies. Many researchers have tried to develop feasible large-scale HTS wind power generator technologies. In this paper, a study on the required performance of a 2G HTS wire for large-scale wind power generators is discussed. A 12 MW class large-scale wind turbine and an HTS generator are designed using 2G HTS wire. The total length of the 2G HTS wire for the 12 MW HTS generator is estimated, and the essential prerequisites of the 2G HTS wire based generator are described. The magnetic field distributions of a pole module are illustrated, and the mechanical stress and strain of the pole module are analysed. Finally, a reasonable price for 2G HTS wire for commercialization of the HTS generator is suggested, reflecting the results of electromagnetic and mechanical analyses of the generator.

  19. Development of scaling rules for Rutherford type superconducting cables

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-09-01

    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.

  20. Modelling aluminium wire bond reliability in high power OMP devices

    NARCIS (Netherlands)

    Kregting, R.; Yuan, C.A.; Xiao, A.; Bruijn, F. de

    2011-01-01

    In a RF power application such as the OMP, the wires are subjected to high current (because of the high power) and high temperature (because of the heat from IC and joule-heating from the wire itself). Moreover, the wire shape is essential to the RF performance. Hence, the aluminium wire is preferre

  1. Neutron scattering studies of superconducting MgB2 tapes

    Science.gov (United States)

    Bellingeri, E.; Malagoli, A.; Modica, M.; Braccini, V.; Siri, A. S.; Grasso, G.

    2003-02-01

    The capability of manufacturing long superconducting MgB2 wires with already remarkable critical currents makes this material a very promising candidate for future applications. Tapes are prepared by the powder-in-tube technique. After the cold working procedure typically carried out by wire drawing and cold rolling, it has been found that a final sintering step carried out in argon atmosphere is a key process for further improving the superconducting properties of the conductors. To study the effect of the deformation and heat treatment processes, we performed neutron scattering experiment. Due to the high penetration depth of neutron inside matter, it was possible to analyse the MgB2 phase still wrapped in the Ni sheath. Our studies were carried out by a full spectra refinement by the Rietveld method. In the starting superconducting powder a large Mg deficiency was observed. In the tapes we found that the large forces applied during the cold working induced a large MgB2 lattice deformation, and that it is partly relaxed during the final sintering process. An important correlation of the residual stress with the critical temperature and the pinning properties was pointed out. We also observed the appearance of detrimental secondary phases during the sintering process. In particular, the MgB2 phase reacted with the nickel sheath and MgB2Ni2.5 was formed at temperatures higher than 850 °C. These results are of basic importance for a further optimization of the transport properties at moderate fields where applications of MgB2 tapes are already envisageable.

  2. Development of ex situ processed MgB 2 wires and their applications to magnets

    Science.gov (United States)

    Braccini, Valeria; Nardelli, Davide; Penco, Roberto; Grasso, Giovanni

    2007-06-01

    In spite of the relatively short time dedicated to the development of magnesium diboride conductors since its discovery in early 2001, a substantial improvement was soon achieved in their manufacture and use. Unlike many others HTS and LTS materials, the MgB 2 conductor processing is more open to a number of improvements and modifications that help in making it more attractive for several DC and AC applications. Many kilometres of conductors were already produced throughout the world and it is now possible to start seriously thinking about a systematic industrial production of this material, as it is already possible to purchase it in reasonable lengths on the free market. These remarkable lengths of conductor were also wound in coils and their performance continuously improved in the past years. Here we will present a review of the recent results and a perspective for the future development of this “new” superconductor, starting from the optimisation of the precursor powders needed to improve the magnetic field behaviour of the tapes, to the conductor development, i.e. the production of multifilamentary Cu-stabilized tapes in lengths up to 1.78 km, to the realization of the first large-scale application devices such as MRI magnets and fault current limiters.

  3. AC/RF Superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, Gianluigi [JLAB

    2015-02-01

    This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

  4. ORNL Superconducting Technology Program for electric power systems. Annual report for FY 1996

    Energy Technology Data Exchange (ETDEWEB)

    Koncinski, W.S. [ed.; Hawsey, R.A. [comp.

    1997-05-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy`s Office of Energy Efficiency and Renewable Energy to develop the science and 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 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 1996 Annual Program Review held July 31 and August 1, 1996. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to cooperative projects with private companies. 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 with US 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.

  5. ORNL Superconducting Technology Program for Electric Power Systems: Annual Report for FY 1999

    Energy Technology Data Exchange (ETDEWEB)

    Hawsey, R.A.

    2000-06-13

    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 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 1999 Annual Program Review held July 26-28, 1999. Aspects of ORNL's work that were presented at the International Cryogenic Materials Conference and the Cryogenic Engineering Conference (July 1999) 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 with private companies. Interlaboratory teams are also in place on a number of industry-driven projects. 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.

  6. ORNL Superconducting Technology Program for Electric Power Systems, Annual Report for FY 1999

    Energy Technology Data Exchange (ETDEWEB)

    Hawsey, R.A.; Murphy, A.W

    2000-04-01

    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 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 1999 Annual Program Review held July 26--28, 1999. Aspects of ORNL's work that were presented at the International Cryogenic Materials Conference and the Cryogenic Engineering Conference (July 1999) 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 with private companies. Interlaboratory teams are also in place on a number of industry-driven projects. 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.

  7. ORNL Superconducting Technology Program for electric power systems: Annual report for FY 1997

    Energy Technology Data Exchange (ETDEWEB)

    Koncinski, W.S.; O`Hara, L.M. [eds.; Hawsey, R.A.; Murphy, A.W. [comps.

    1998-03-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy`s Office of Energy Efficiency and Renewable Energy to develop the science and 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 applications development. This document describes the major research and developments 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 1997 Annual Program Review held July 21--23, 1997. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to cooperative projects with private companies. 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 with US 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.

  8. A new approach to a superconducting joining process for carbon-doped MgB2 conductor

    Science.gov (United States)

    Patel, Dipak; Hossain, Md Shahriar Al; Maeda, Minoru; Shahabuddin, Mohammed; Yanmaz, Ekrem; Pradhan, Subrata; Tomsic, Mike; Choi, Seyong; Kim, Jung Ho

    2016-09-01

    We report a new approach to a superconducting joining process for unreacted in situ carbon (C)-doped magnesium diboride (MgB2) wires. To operate a magnetic resonance imaging (MRI) magnet in the persistent mode, the superconducting joints between two conductors are as critical as the other key components. In addition, a stable and reliable joining process enables the superconducting magnet to operate without an external power supply. However, joint results using unreacted in situ C-doped MgB2 wires, which are used for high-field operation, have been limited, and only very poor performance has been obtained. By controlling the pressure inside a joint part, in this study, we successfully obtained current carrying retention in the joint of up to 72% compared to wire without a joint. The closed-circuit resistance of our closed-loop coil was less than 1.8 × 10-13 Ω at 16.7 ± 4.7 K, as measured by the field-decay measurement method. These results indicate that MgB2 has a promising future in MRI application.

  9. Insulation and Heat Treatment of Bi-2212 Wire for Wind-and-React Coils

    Energy Technology Data Exchange (ETDEWEB)

    Peter K. F. Hwang

    2007-10-22

    Higher Field Magnets demand higher field materials such as Bi-2212 round superconducting wire. The Bi-2212 wire manufacture process depends on the coil fabrication method and wire insulation material. Considering the wind-and-react method, the coil must unifirmly heated to the melt temperature and uniformly cooled to the solidification temperature. During heat treat cycle for tightly wound coils, the leakage melt from conductor can chemically react with insulation on the conductor and creat short turns in the coils. In this research project, conductor, insulation, and coils are made to systemically study the suitable insulation materials, coil fabrication method, and heat treatment cycles. In this phase I study, 800 meters Bi-2212 wire with 3 different insulation materials have been produced. Best insulation material has been identified after testing six small coils for insulation integrity and critical current at 4.2 K. Four larger coils (2" dia) have been also made with Bi-2212 wrapped with best insulation and with different heattreatment cycle. These coils were tested for Ic in a 6T background field and at 4.2 K. The test result shows that Ic from 4 coils are very close to short samples (1 meter) result. It demonstrates that HTS coils can be made with Bi-2212 wire with best insulation consistently. Better wire insulation, improving coil winding technique, and wire manufacture process can be used for a wide range of high field magnet application including acclerators such as Muon Collider, fusion energy research, NMR spectroscopy, MRI, and other industrial magnets.

  10. Flexible Microstrip Circuits for Superconducting Electronics

    Science.gov (United States)

    Chervenak, James; Mateo, Jennette

    2013-01-01

    Flexible circuits with superconducting wiring atop polyimide thin films are being studied to connect large numbers of wires between stages in cryogenic apparatus with low heat load. The feasibility of a full microstrip process, consisting of two layers of superconducting material separated by a thin dielectric layer on 5 mil (approximately 0.13 mm) Kapton sheets, where manageable residual stress remains in the polyimide film after processing, has been demonstrated. The goal is a 2-mil (approximately 0.051-mm) process using spin-on polyimide to take advantage of the smoother polyimide surface for achieving highquality metal films. Integration of microstrip wiring with this polyimide film may require high-temperature bakes to relax the stress in the polyimide film between metallization steps.

  11. NORPAS - NORdic program of applied superconductivity. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mikkonen, R. [ed.

    1995-12-31

    High temperature superconducting (HTS) wire is rapidly maturing into a working material being produced in ever larger quantities and being used in more significant demonstrations and prototypes. Conductor is now produced routinely in several hundred meter lengths with reproducible results. Current density has progressed to a level suitable for demonstration on many applications. As with any technology trying to find a niche, widespread commercialization can only occur if the new technology can match the performance of an existing technology at a lower cost, or the new technology represents a breakthrough in capabilities, irrespective of cost, in turn enabling functionality previously thought impossible. There are two obvious areas where HTS will have significant benefit. The first is all applications which will notably benefit from a reduction in refrigeration power. The second area is the market of very high field magnets where there is no viable alternative. Applications under consideration for HTS include: (1) Rotating electrical machines (synchronous ac and homopolar dc motors), (2) Underground transmission cables, (3) Superconducting Magnetic Energy Storage (SMES), (4) Utility distribution equipment such as transformers and current limiters, (5) Commercial processing applications such as magnetic separation. (6) Military applications such as mine clearing, (7) Specialty magnets such as high field inserts

  12. Evaluations of MgB2 Coatings on 2'' Copper Discs for Superconducting Radio Frequency Applications

    Science.gov (United States)

    Withanage, Wenura; Tan, Teng; Lee, Namhoon; Banjade, Huta; Eremeev, Grigory; Welander, Paul; Valente-Feliciano, Anne-Marie; Kustom, Robert; Wolak, Matthäus; Nassiri, Alireza; Xi, Xiaoxing

    We propose that coating the inner walls of copper RF cavities with superconducting MgB2 (Tc = 39 K) can result in a viable alternative to the already established niobium-based SRF technology. This approach improves the thermal conductivity, allows for operation at higher temperatures, and reduces the need for large helium refrigeration, thereby resulting in lower operational costs. For our studies, we grew MgB2 films via hybrid physical chemical vapor deposition (HPCVD) on 2'' Cu substrates. Since Mg and Cu readily form an alloy at higher temperatures, the HPCVD setup was modified in order to achieve lower deposition temperatures, minimize alloy formation, and provide high quality MgB2 films. This method yielded MgB2 coatings on 2'' Cu discs with transition temperatures around 38 K. The samples were characterized with regards to their RF attributes and showed similar performance in comparison to Nb reference samples. The presented results show that MgB2 coated copper can be a suitable alternative for use in SRF cavities.

  13. Physics and application of photon number resolving detectors based on superconducting parallel nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Marsili, F; Bitauld, D; Jahanmirinejad, S; Fiore, A [COBRA Research Institute, Eindhoven University of Technology, PO Box 513, NL-5600MB Eindhoven (Netherlands); Gaggero, A; Leoni, R; Mattioli, F [Istituto di Fotonica e Nanotecnologie (IFN), CNR, via Cineto Romano 42, 00156 Roma (Italy)], E-mail: marsili@MIT.EDU

    2009-04-15

    The parallel nanowire detector (PND) is a photon number resolving (PNR) detector that uses spatial multiplexing on a subwavelength scale to provide a single electrical output proportional to the photon number. The basic structure of the PND is the parallel connection of several NbN superconducting nanowires ({approx}100 nm wide, a few nm thick), folded in a meander pattern. PNDs were fabricated on 3-4 nm thick NbN films grown on MgO (T{sub S} = 400 deg. C) substrates by reactive magnetron sputtering in an Ar/N{sub 2} gas mixture. The device performance was characterized in terms of speed and sensitivity. PNDs showed a counting rate of 80 MHz and a pulse duration as low as 660 ps full-width at half-maximum (FWHM). Building the histograms of the photoresponse peak, no multiplication noise buildup is observable. Electrical and optical equivalent models of the device were developed in order to study its working principle, define design guidelines and develop an algorithm to estimate the photon number statistics of an unknown light. In particular, the modeling provides novel insight into the physical limit to the detection efficiency and to the reset time of these detectors. The PND significantly outperforms existing PNR detectors in terms of simplicity, sensitivity, speed and multiplication noise.

  14. Application of International Linear Collider superconducting cavities for acceleration of protons

    Directory of Open Access Journals (Sweden)

    P. N. Ostroumov

    2007-12-01

    Full Text Available Beam acceleration in the International Linear Collider (ILC will be provided by 9-cell 1300 MHz superconducting (SC cavities. The cavities are designed for effective acceleration of charged particles moving with the speed of light and are operated on π-mode to provide a maximum accelerating gradient. A significant research and development effort has been devoted to develop ILC SC technology and its rf system which resulted in excellent performance of ILC cavities. Therefore, the proposed 8-GeV proton driver in Fermilab is based on ILC cavities above ∼1.2  GeV. The efficiency of proton beam acceleration by ILC cavities drops fast for lower velocities and it was proposed to develop squeezed ILC-type (S-ILC cavities operating at 1300 MHz and designed for β_{G}=0.81, geometrical beta, to accelerate protons or H^{-} from ∼420  MeV to 1.2 GeV. This paper discusses the possibility of avoiding the development of new β_{G}=0.81 cavities by operating ILC cavities on 8/9π-mode of standing wave oscillations.

  15. Superconducting properties of internally stabilized Nb{sub 3}Al wires fabricated by rapid-quenched and transformed process; Naibu anteika kyunetsu kyurei{center_dot}hentai ho Nb{sub 3}Al senzai no chodendo tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Tagawa, K. [Hitachi Cable, Ltd., Tokyo (Japan); National Research Institute for Metals, Tokyo (Japan); Japan Science and Technology Corp., Saitama (Japan); Nakagawa, K. [Hitachi Cable, Ltd., Tokyo (Japan); Takeuchi, T.; Banno, N.; Kiyoshi, T.; Ito, K.; Wada, H. [National Research Institute for Metals, Tokyo (Japan); Yuyama, M.; Kosuge, M. [National Research Institute for Metals, Tokyo (Japan)

    2000-05-29

    Nb{sub 3}AL wire using Ag coated by Nb as stabilizer was manufactured as trial and the critical current density Jc was examined. Compared Ag with Nb as fill-in core bar, Jc of wire using silver filament core bar was higher than one using Nb filament core. It was considered that uniform current in Ag caused to produce homogeneous solid solution. Jc also increased by about 45% following processing of decreasing area after rapid heating and quench. N value also showed at least a value above and equal to 25 at the 21 T magnetic field. (NEDO)Nb{sub 3}AL wire using Ag coated by Nb as stabilizer was manufactured as trial and the critical current density Jc was examined. Compared Ag with Nb as fill-in core bar, Jc of wire using silver filament core bar was higher than one using Nb filament core. It was considered that uniform current in Ag caused to produce homogeneous solid solution. Jc also increased by about 45% following processing of decreasing area after rapid heating and quench. N value also showed at least a value above and equal to 25 at the 21 T magnetic field. (NEDO)

  16. Relativistic dynamics of superfluid-superconducting mixtures in the presence of topological defects and an electromagnetic field with application to neutron stars

    Science.gov (United States)

    Gusakov, M. E.; Dommes, V. A.

    2016-10-01

    The relativistic dynamic equations are derived for a superfluid-superconducting mixture coupled to an electromagnetic field. For definiteness, and bearing in mind possible applications of our results to neutron stars, it is assumed that the mixture is composed of superfluid neutrons, superconducting protons, and normal electrons. We analyze the proton superconductivity of both types I and II and allow for the possible presence of neutron and proton vortices (or magnetic domains in the case of type-I proton superconductivity). The derived equations neglect all dissipative effects except for the mutual friction dissipation and are valid for arbitrary temperatures (i.e., they do not imply that all nucleons are paired), which is especially important for magnetar conditions. It is demonstrated that these general equations can be substantially simplified for typical neutron stars, for which a kind of magnetohydrodynamic approximation is justified. Our results are compared to the nonrelativistic formulations existing in the literature, and a number of discrepancies are found. In particular, it is shown that, generally, the electric displacement D does not coincide with the electric field E , contrary to what is stated in previous works. The relativistic framework developed here is easily extendable to account for more sophisticated microphysics models, and it provides the necessary basis for realistic modeling of neutron stars.

  17. Replacement of corrosion protection chromate primers and paints used in cryogenic applications on the Space Shuttle with wire arc sprayed aluminum coatings

    Science.gov (United States)

    Daniel, R. L.; Sanders, H. L.; Zimmerman, F. R.

    1995-01-01

    With the advent of new environmental laws restricting volatile organic compounds and hexavalent chrome emissions, 'environmentally safe' thermal spray coatings are being developed to replace the traditional corrosion protection chromate primers. A wire arc sprayed aluminum coating is being developed for corrosion protection of low pressure liquid hydrogen carrying ducts on the Space Shuttle Main Engine. Currently, this hardware utilizes a chromate primer to provide protection against corrosion pitting and stress corrosion cracking induced by the cryogenic operating environment. The wire are sprayed aluminum coating has been found to have good potential to provide corrosion protection for flight hardware in cryogenic applications. The coating development, adhesion test, corrosion test and cryogenic flexibility test results will be presented.

  18. The Characterization of Twin-Wire Arc-Sprayed FeCrBSi Coating and the Application in Sewage Sludge Boilers

    Science.gov (United States)

    Qin, Enwei; Huang, Qian; Shao, Yumin; Chen, Guoxing; Ye, Lin; Gu, Qin; Wu, Shuhui

    2014-12-01

    Incineration in boilers is an environment-friendly treatment for industrial and civil sewage sludge. However, due to the aggressive nature of the sludge, the boiler fireside-surface is subjected to severe wear, erosive, and high temperature corrosion problems during incineration. In this study, we developed an economical FeCrBSi wire material with iron weight content as high as 80%. The coating was prepared by twin-wire arc spraying processing. The chemical compositions of the coating, as well as phase components were analyzed by energy-dispersive spectroscopy and x-ray diffraction method. The surface roughness, porosity, and cross-sectional morphology were further characterized. The coating hardness is close to that of the commercial Armacor M and Armacor C materials. In-boiler test was also carried out. The low thickness loss of the tube indicates a promising application future in sludge boilers.

  19. Performance of wire-type Rn detectors operated with gas gain in ambient air in view of its possible application to early earthquake predictions

    CERN Document Server

    Charpak, Georges; Breuil, P; Nappi, E; Martinengo, P; Peskov, V

    2010-01-01

    We describe a detector of alpha particles based on wire type counters (single-wire and multiwire) operating in ambient air at high gas gains (100-1000). The main advantages of these detectors are: low cost, robustness and ability to operate in humid air. The minimum detectable activity achieved with the multiwire detector for an integration time of 1 min is 140 Bq per m3, which is comparable to that featured by commercial devices. Owing to such features the detector is suited for massive application, for example for continuous monitoring of Rn or Po contaminations or, as discussed in the paper, its use in a network of Rn counters in areas affected by earth-quakes in order to verify, on a solid statistical basis, the envisaged correlation between the sudden Rn appearance and a forthcoming earthquake.

  20. Fios ortodônticos: conhecer para otimizar a aplicação clínica Orthodontic wires: knowledge to optimize clinical application

    Directory of Open Access Journals (Sweden)

    Cátia Cardoso Abdo Quintão

    2009-12-01

    Full Text Available A grande variedade de fios ortodônticos presente no mercado pode gerar dúvidas quanto à melhor escolha para situações clínicas. Assim, o conhecimento das propriedades mecânicas dos mesmos facilita a escolha para aplicação do movimento ortodôntico na dependência da fase em que o tratamento se encontra. A evolução da tecnologia de manufatura dos fios e a elaboração de novas técnicas ortodônticas geraram a busca por uma melhor qualidade das ligas, a fim de torná-los biologicamente mais efetivos no que diz respeito aos dentes e tecidos de suporte. O presente artigo resume as principais características dos fios utilizados em Ortodontia, em relação ao histórico, propriedades mecânicas e aplicação clínica, de acordo com fases específicas de tratamento.The huge variety of orthodontic wires brands available in market might generate confusion as regard to the best choice for clinical application. Therefore mechanical properties knowledge about wires would help the professional to apply the best orthodontic technique depending on the treatment phase. The wires manufacturing evolution and the new orthodontic techniques proposed guided the market into the search for better quality alloys, in order to make them biologically more effective to teeth and support tissues. This paper aims to summarize some main characteristics of orthodontic wires related to their history, mechanical properties and clinical application as regard to individual phase of treatment.

  1. Advanced nuclear materials development -Development of superconductor application technology-

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Kye Won; Lee, Heui Kyoon; Lee, Hoh Jin; Kim, Chan Joong; Jang, Kun Ik; Kim, Kee Baek; Kwon, Sun Chil; Park, Hae Woong; Yoo, Jae Keun; Kim, Jong Jin; Jang, Joong Chul; Yang, Suk Woo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-07-01

    Fabrication of high Tc bulk superconductor and its application, fabrication of superconducting wire for electric power device and analysis for cryogenic system were carried out for developing superconductor application technologies for electric power system. High quality YBaCuO bulk superconductor was fabricated by controlling initial powder preparation process and prototype fly wheel energy storage device was designed basically. The superconducting levitation force measuring device was made to examine the property of prepared superconductor specimen. Systematic studies on the method of starting powder preparation, mechanical fabrication process, heat treatment condition and analysis of plastic deformation were carried out to increase the stability and reproducibility of superconducting wire. A starting powder with good reactivity and fine particle size was obtained by emulsion drying method. Ag/BSCCO tape with good cross sectional shape and Tc of 16,000 A/cm{sup 2} was fabricated by applying CIP packing procedure. Multifilamentary wire with the Jc of approx. 10000 A/cm{sup 2} was fabricated by rolling method using square billet as starting shape. The joining of the multifilament wire was done by etching and pressing process and showed 50% of joining efficiency. Analysis on the heat loss in cryostat for high Tc superconducting device was carried out for optimum design of the future cryogenic system. 126 figs, 14 tabs, 214 refs. (Author).

  2. Superconductivity an introduction

    CERN Document Server

    Kleiner, Reinhold

    2016-01-01

    The third edition of this proven text has been developed further in both scope and scale to reflect the potential for superconductivity in power engineering to increase efficiency in electricity transmission or engines. The landmark reference remains a comprehensive introduction to the field, covering every aspect from fundamentals to applications, and presenting the latest developments in organic superconductors, superconducting interfaces, quantum coherence, and applications in medicine and industry. Due to its precise language and numerous explanatory illustrations, it is suitable as an introductory textbook, with the level rising smoothly from chapter to chapter, such that readers can build on their newly acquired knowledge. The authors cover basic properties of superconductors and discuss stability and different material groups with reference to the latest and most promising applications, devoting the last third of the book to applications in power engineering, medicine, and low temperature physics. An e...

  3. High Tc Superconducting Materials for Strong Current Applications: Approach at the First Stage

    Institute of Scientific and Technical Information of China (English)

    JIN Jian-xun

    2007-01-01

    Strong current and large-scale application is the most important prospect of high Tc superconductors (HTS). Practical HTS samples in various forms have been produced with high critical currents operated at economic cryogenic temperatures. Engineering applications of those HTS materials have been studied with various HTS prototype devices. The applicable HTS materials produced in different forms are verified in this paper with regard to their strong current characterizations, and the HTS applications are summarized along with the HTS prototypes made.

  4. Negative Magnetoresistance in Amorphous Indium Oxide Wires

    Science.gov (United States)

    Mitra, Sreemanta; Tewari, Girish C.; Mahalu, Diana; Shahar, Dan

    2016-11-01

    We study magneto-transport properties of several amorphous Indium oxide nanowires of different widths. The wires show superconducting transition at zero magnetic field, but, there exist a finite resistance at the lowest temperature. The R(T) broadening was explained by available phase slip models. At low field, and far below the superconducting critical temperature, the wires with diameter equal to or less than 100 nm, show negative magnetoresistance (nMR). The magnitude of nMR and the crossover field are found to be dependent on both temperature and the cross-sectional area. We find that this intriguing behavior originates from the interplay between two field dependent contributions.

  5. Static synchronous compensator with superconducting magnetic energy storage for high power utility applications

    Energy Technology Data Exchange (ETDEWEB)

    Molina, Marcelo G.; Mercado, Pedro E. [CONICET, Instituto de Energia Electrica, Universidad Nacional de San Juan (Argentina); Watanabe, Edson H. [COPPE, Grupo de Eletronica de Potencia, Universidade Federal do Rio de Janeiro (Brazil)

    2007-08-15

    Power systems security in the case of contingencies is ensured by maintaining adequate 'short-term generation reserve'. This reserve must be appropriately activated by means of the primary frequency control (PFC). Because the generation is an electro-mechanical process, the primary control reserve controllability is not as fast as required, especially by modern power systems. Since the new improvements achieved on the conventional control methods have not been enough to satisfy the high requirements established, the necessity of enhancing the performance of the PFC has arisen. At present, the new energy storage systems (ESS) are a feasible alternative to store excess energy for substituting for the primary control reserve. In this way, it is possible to combine this new ESS with power converter based flexible ac transmission systems (FACTS). This allows an effective exchange of active power with the electric grid and, thus, enhances the PFC. This paper presents an improved PFC scheme incorporating a static synchronous compensator (STATCOM) coupled with a superconducting magnetic energy storage (SMES) device. A detailed full model and a control algorithm based on a decoupled current control strategy of the enhanced compensator are proposed. The integrated STATCOM/SMES controller topology includes three level, multi-pulse, voltage source inverters (VSI) with phase control and incorporates a two quadrant, three level, dc-dc chopper as the interface between the STATCOM and the SMES coil. A novel three level control scheme is proposed by using concepts of instantaneous power in the synchronous rotating d-q reference frame. The dynamic performance of the presented control algorithms is evaluated through digital simulation performed by using SimPowerSystems of SIMULINK/MATLAB {sup trademark}, and technical analysis is performed to obtain conclusions about the benefits of using SMES devices in the PFC of the electric system. Presently, a laboratory scale

  6. Operational Merits of Maritime Superconductivity

    Science.gov (United States)

    Ross, R.; Bosklopper, J. J.; van der Meij, K. H.

    The perspective of superconductivity to transfer currents without loss is very appealing in high power applications. In the maritime sector many machines and systems exist in the roughly 1-100 MW range and the losses are well over 50%, which calls for dramatic efficiency improvements. This paper reports on three studies that aimed at the perspectives of superconductivity in the maritime sector. It is important to realize that the introduction of superconductivity comprises two technology transitions namely firstly electrification i.e. the transition from mechanical drives to electric drives and secondly the transition from normal to superconductive electrical machinery. It is concluded that superconductivity does reduce losses, but its impact on the total energy chain is of little significance compared to the investments and the risk of introducing a very promising but as yet not proven technology in the harsh maritime environment. The main reason of the little impact is that the largest losses are imposed on the system by the fossil fueled generators as prime movers that generate the electricity through mechanical torque. Unless electric power is supplied by an efficient and reliable technology that does not involve mechanical torque with the present losses both normal as well as superconductive electrification of the propulsion will hardly improve energy efficiency or may even reduce it. One exception may be the application of degaussing coils. Still appealing merits of superconductivity do exist, but they are rather related to the behavior of superconductive machines and strong magnetic fields and consequently reduction in volume and mass of machinery or (sometimes radically) better performance. The merits are rather convenience, design flexibility as well as novel applications and capabilities which together yield more adequate systems. These may yield lower operational costs in the long run, but at present the added value of superconductivity rather seems more

  7. Nonequilibrium superconducting detectors

    Science.gov (United States)

    Cristiano, R.; Ejrnaes, M.; Esposito, E.; Lisitskyi, M. P.; Nappi, C.; Pagano, S.; Perez de Lara, D.

    2006-03-01

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  8. Nonequilibrium superconducting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, R [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Ejrnaes, M [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); INFN Sezione di Napoli, 80126 Naples (Italy); Esposito, E [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Lisitskyi, M P [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Nappi, C [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Pagano, S [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Dipartimento di Fisica, Universita di Salerno, 84081 Baronissi (Saudi Arabia) (Italy); Perez de Lara, D [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy)

    2006-03-15

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  9. ORNL Superconducting Technology Program for electric power systems. Annual report for FY 1995

    Energy Technology Data Exchange (ETDEWEB)

    Hawsey, R.A. [comp.; Turner, J.W. [ed.

    1996-05-01

    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 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 1995 Annual Program Review held August 1-2, 1995. 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 with private companies. 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 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.

  10. ORNL Superconducting Technology Program for Electric Energy Systems. Annual report for FY 1992

    Energy Technology Data Exchange (ETDEWEB)

    Hawsey, R.A. [comp.

    1993-02-01

    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.

  11. Normal zone propagation in adiabatic superconducting magnets: Pt. 1; Normal zone propagation velocity in superconducting composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Z.P.; Iwasa, Y. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Francis Bitter National Magnet Lab. Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center)

    1991-09-01

    A normal zone propagation model has been developed for superconducting composites under adiabatic conditions. It is based on the Whetstone-Roos model, originally developed for normal zone propagation in adiabatic wires of unclad superconductor. The model takes into account the temperature and magnetic field dependent material properties, for both superconductor and matrix metal. Analytical results agree well with experimental data. (author).

  12. Surface polishing of niobium for superconducting radio frequency (SRF) cavity applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Liang [College of William and Mary, Williamsburg, VA (United States)

    2014-08-01

    Niobium cavities are important components in modern particle accelerators based on superconducting radio frequency (SRF) technology. The interior of SRF cavities are cleaned and polished in order to produce high accelerating field and low power dissipation on the cavity wall. Current polishing methods, buffered chemical polishing (BCP) and electro-polishing (EP), have their advantages and limitations. We seek to improve current methods and explore laser polishing (LP) as a greener alternative of chemical methods. The topography and removal rate of BCP at different conditions (duration, temperature, sample orientation, flow rate) was studied with optical microscopy, scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD). Differential etching on different crystal orientations is the main contributor to fine grain niobium BCP topography, with gas evolution playing a secondary role. The surface of single crystal and bi-crystal niobium is smooth even after heavy BCP. The topography of fine grain niobium depends on total removal. The removal rate increases with temperature and surface acid flow rate within the rage of 0~20 °C, with chemical reaction being the possible dominate rate control mechanism. Surface flow helps to regulate temperature and avoid gas accumulation on the surface. The effect of surface flow rate on niobium EP was studied with optical microscopy, atomic force microscopy (AFM), and power spectral density (PSD) analysis. Within the range of 0~3.7 cm/s, no significant difference was found on the removal rate and the macro roughness. Possible improvement on the micro roughness with increased surface flow rate was observed. The effect of fluence and pulse accumulation on niobium topography during LP was studied with optical microscopy, SEM, AFM, and PSD analysis. Polishing on micro scale was achieved within fluence range of 0.57~0.90 J/cm2, with pulse accumulation adjusted accordingly. Larger area treatment was proved possible by

  13. Flexible superconducting Nb transmission lines on thin film polyimide for quantum computing applications

    Science.gov (United States)

    Tuckerman, David B.; Hamilton, Michael C.; Reilly, David J.; Bai, Rujun; Hernandez, George A.; Hornibrook, John M.; Sellers, John A.; Ellis, Charles D.

    2016-08-01

    We describe progress and initial results achieved towards the goal of developing integrated multi-conductor arrays of shielded controlled-impedance flexible superconducting transmission lines with ultra-miniature cross sections and wide bandwidths (dc to >10 GHz) over meter-scale lengths. Intended primarily for use in future scaled-up quantum computing systems, such flexible thin-film niobium/polyimide ribbon cables could provide a physically compact and ultra-low thermal conductance alternative to the rapidly increasing number of discrete coaxial cables that are currently used by quantum computing experimentalists to transmit signals between the several low-temperature stages (from ˜4 K down to ˜20 mK) of a dilution refrigerator. We have concluded that these structures are technically feasible to fabricate, and so far they have exhibited acceptable thermo-mechanical reliability. S-parameter results are presented for individual 2-metal layer Nb microstrip structures having 50 Ω characteristic impedance; lengths ranging from 50 to 550 mm were successfully fabricated. Solderable pads at the end terminations allowed testing using conventional rf connectors. Weakly coupled open-circuit microstrip resonators provided a sensitive measure of the overall transmission line loss as a function of frequency, temperature, and power. Two common microelectronic-grade polyimide dielectrics, one conventional and the other photo-definable (PI-2611 and HD-4100, respectively) were compared. Our most striking result, not previously reported to our knowledge, was that the dielectric loss tangents of both polyimides, over frequencies from 1 to 20 GHz, are remarkably low at deep cryogenic temperatures, typically 100× smaller than corresponding room temperature values. This enables fairly long-distance (meter-scale) transmission of microwave signals without excessive attenuation, and also permits usefully high rf power levels to be transmitted without creating excessive dielectric

  14. Proof-of-principle demonstration of Nb3Sn superconducting radiofrequency cavities for high Q0 applications

    Science.gov (United States)

    Posen, S.; Liepe, M.; Hall, D. L.

    2015-02-01

    Many future particle accelerators require hundreds of superconducting radiofrequency (SRF) cavities operating with high duty factor. The large dynamic heat load of the cavities causes the cryogenic plant to make up a significant part of the overall cost of the facility. This contribution can be reduced by replacing standard niobium cavities with ones coated with a low-dissipation superconductor such as Nb3Sn. In this paper, we present results for single cell cavities coated with Nb3Sn at Cornell. Five coatings were carried out, showing that at 4.2 K, high Q0 out to medium fields was reproducible, resulting in an average quench field of 14 MV/m and an average 4.2 K Q0 at quench of 8 × 109. In each case, the peak surface magnetic field at quench was well above Hc1, showing that it is not a limiting field in these cavities. The coating with the best performance had a quench field of 17 MV/m, exceeding gradient requirements for state-of-the-art high duty factor SRF accelerators. It is also shown that—taking into account the thermodynamic efficiency of the cryogenic plant—the 4.2 K Q0 values obtained meet the AC power consumption requirements of state-of-the-art high duty factor accelerators, making this a proof-of-principle demonstration for Nb3Sn cavities in future applications.

  15. Application of a modified flux-coupling type superconducting fault current limiter to transient performance enhancement of micro-grid

    Science.gov (United States)

    Chen, Lei; Zheng, Feng; Deng, Changhong; Li, Shichun; Li, Miao; Liu, Hui; Zhu, Lin; Guo, Fang

    2015-11-01

    Concerning the application and development of a micro-grid system which is designed to accommodate high penetration of intermittent renewable resources, one of the main issues is related to an increase in the fault-current level. It is crucial to ensure the micro-grid's operational stability and service reliability when a fault occurs in the main network. In this paper, our research group suggests a modified flux-coupling type superconducting fault current limiter (SFCL) to enhance the transient performance of a typical micro-grid system. The SFCL is installed at the point of common coupling (PCC) between the main network and the micro-grid, and it is expected to actively improve the micro-grid's fault ride-through capability. And for some specific faults, the micro-grid should disconnect from the main network, and the SFCL's contribution is to make the micro-grid carry out a smooth transition between its grid-connected and islanded modes. Related theory derivation, technical discussion and simulation analysis are performed. From the demonstrated results, applying the SFCL can effectively limit the fault current, maintain the power balance, and enhance the voltage and frequency stability of the micro-grid.

  16. First application of superconducting transition-edge-sensor microcalorimeters to hadronic-atom x-ray spectroscopy

    CERN Document Server

    Okada, S; Curceanu, C; Doriese, W B; Fowler, J W; Gard, J; Gustafsson, F P; Hashimoto, T; Hayano, R S; Hirenzaki, S; Hays-Wehle, J P; Hilton, G C; Ikeno, N; Iliescu, M; Ishimoto, S; Itahashi, K; Iwasaki, M; Koike, T; Kuwabara, K; Ma, Y; Marton, J; Noda, H; O'Neil, G C; Outa, H; Reintsema, C D; Sato, M; Schmidt, D R; Shi, H; Suzuki, K; Suzuki, T; Swetz, D S; Tatsuno, H; Uhlig, J; Ullom, J N; Widmann, E; Yamada, S; Yamagata-Sekihara, J; Zmeskal, J

    2016-01-01

    High-resolution pionic-atom x-ray spectroscopy was performed with an x-ray spectrometer based on a 240-pixel array of superconducting transition-edge-sensor (TES) microcalorimeters at the piM1 beam line of the Paul Scherrer Institute. X-rays emitted by pionic carbon via the 4f->3d transition and the parallel 4d->3p transition were observed with a full-width-at-half-maximum energy resolution of 6.8 eV at 6.4 keV. Measured x-ray energies are consistent with calculated electromagnetic values which considered the strong-interaction effect assessed via the Seki-Masutani potential for the 3p energy level, and favor the electronic population of two filled 1s electrons in the K-shell. Absolute energy calibration with an uncertainty of 0.1 eV was demonstrated under a high-rate hadron beam condition of 1.45 MHz. This is the first application of a TES spectrometer to hadronic-atom x-ray spectroscopy and is an important milestone towards next-generation high-resolution kaonic-atom x-ray spectroscopy.

  17. Dissipative processes in superconducting nanodevices: Nanowire-resonators, shunted nanowires, and graphene proximity junctions

    Science.gov (United States)

    Brenner, Matthew W.

    The topic of superconducting nanowires has recently been an interesting field of research which has included the study of the superconductor to insulator transition (SIT), the observation of macroscopic quantum behavior such as quantum phase slips (QPS), and the potential use of nanowires as qubits. Superconducting coplanar microwave waveguide resonators have also become a popular way of studying superconducting junctions and qubits, as they provide an extremely low noise environment. For example, superconducting two-dimensional Fabry-Perot resonators have been used by other groups to make non-demolition measurements of a qubit. The motivation of this thesis will be the merging of the fields of superconducting nanowires and the technique of using superconducting microwave resonators to study junctions by incorporating a nanowire into the resonator itself at a current anti-node. By doing this, the nonlinear effects of the nanowire can be studied which may find application in single photon detectors, mixers, and the readout of qubits. We also employ the technique of molecular templating to fabricate some of the thinnest superconducting nanowires ever studied (down to ˜ 5 nm in diameter in some cases). In this thesis, we extend the understanding of the nonlinear properties of a nanowire-resonator system and investigate a new type of nonlinearity that involves a pulsing regime between the superconducting and normal phases of the nanowire. We develop a model, which describes the results quantitatively and by modeling the system, we are able to extract information regarding the relaxation time of the nanowire back into the superconducting state. We also study double nanowire-resonator systems where two closely spaced parallel nanowires interrupt the resonator center conductor and form a loop where vortex tunneling processes can occur. Using a double nanowire-resonator we are able to observe the Little-Parks effect at low temperatures (where the resistance of the wires

  18. Proceedings of the 55th Meeting on Cryogenics and Superconductivity; Dai 55 kai 1996 nendo shuki teion kogaku chodendo gakkai koen gaiyoshu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-06

    This is a proceedings of the 55th Meeting on Cryogenics and Superconductivity. As for wires, made public were Bi-system 2223, Y-system NbTi, NbSn, Nb3Al, etc. As to oxide superconductors, some of them are promising. The study of those characteristics and the developmental application to the electric power field such as coils and cables were introduced. Beside wires, multilayer film superconductors were also introduced. With relation to fundamentals and theories, became topics were pinning characteristics, NbTi proximity effects, magnetic flux and visualization, stability, etc. About the application, large refrigerators are discussed in the refrigeration field in addition to GM/pulse tube refrigerators. Concerning cooling technology, made public were the development of a floating railroad use 80K cooling system, etc. Also studied were power leads, superconducting magnet, control action characteristics, etc. SMES (superconducting magnetic energy storage) also became a topic, and the element coil energization experiment, stability and mechanical properties were described. The paper also touched on accelerators, large superconducting devices such as LHD (large helical device) and ITER (international thermal-nuclear experimental reactor) as well as generators and current limiters. The cryogenetic engineering was also reported such as fracture toughness and superfluidity of cryostats and structural materials for extremely low temperatures.

  19. Proceedings of the 55th Meeting on Cryogenics and Superconductivity; Dai 55 kai 1996 nendo shuki teion kogaku chodendo gakkai koen gaiyoshu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-06

    This is a proceedings of the 55th Meeting on Cryogenics and Superconductivity. As for wires, made public were Bi-system 2223, Y-system NbTi, NbSn, Nb3Al, etc. As to oxide superconductors, some of them are promising. The study of those characteristics and the developmental application to the electric power field such as coils and cables were introduced. Beside wires, multilayer film superconductors were also introduced. With relation to fundamentals and theories, became topics were pinning characteristics, NbTi proximity effects, magnetic flux and visualization, stability, etc. About the application, large refrigerators are discussed in the refrigeration field in addition to GM/pulse tube refrigerators. Concerning cooling technology, made public were the development of a floating railroad use 80K cooling system, etc. Also studied were power leads, superconducting magnet, control action characteristics, etc. SMES (superconducting magnetic energy storage) also became a topic, and the element coil energization experiment, stability and mechanical properties were described. The paper also touched on accelerators, large superconducting devices such as LHD (large helical device) and ITER (international thermal-nuclear experimental reactor) as well as generators and current limiters. The cryogenetic engineering was also reported such as fracture toughness and superfluidity of cryostats and structural materials for extremely low temperatures.

  20. Superconducting magnets. Citations from NTIS data base

    Science.gov (United States)

    Reimherr, G. W.

    1980-10-01

    The cited reports discuss research on materials studies, theory, design and applications of superconducting magnets. Examples of applications include particle accelerators, MHD power generation, superconducting generators, nuclear fusion research devices, energy storage systems, and magnetic levitation. This updated bibliography contains 218 citations, 88 of which are new entries to the previous edition.

  1. Subchannel Analysis of Wire Wrapped SCWR Assembly

    OpenAIRE

    Jianqiang Shan; Henan Wang; Wei Liu; Linxing Song; Xuanxiang Chen; Yang Jiang

    2014-01-01

    Application of wire wrap spacers in SCWR can reduce pressure drop and obtain better mixing capability. As a consequence, the required coolant pumping power is decreased and the coolant temperature profile inside the fuel bundle is flattened which will obviously decrease the peak cladding temperature. The distributed resistance model for wire wrap was developed and implemented in ATHAS subchannel analysis code. The HPLWR wire wrapped assembly was analyzed. The results show that: (1) the assemb...

  2. Phase Slips in Topological Superconductor Wire Devices

    Science.gov (United States)

    Goldberg, Samuel; Bergman, Doron; Pekker, David; Refael, Gil

    2012-02-01

    We make a detailed study of phase slips in topological superconducting wires and devices based on topological wires. We begin by investigating a device composed of a topological superconducting wire connected to a non-topological wire (T-S). In the T-segment only slips of the phase by multiples of 4π are allowed, while in the S-segment slips by 2π are also allowed. We show that near the interface, 2π phase slips are also allowed and we comment on the consequences of such phase slips for the Aharonov-Casher effect. We also consider an implementation of a q-bit consisting of a T-S-T device, where the quantum information is stored in the parity of the two topological segments via the four Majorana modes. We show that the central S-segment of this type of device can support 2π phase-slips which result in the decoherence of the q-bit.

  3. 30 CFR 75.1003 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Science.gov (United States)

    2010-07-01

    ... wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 75.1003 Section 75.1003... Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. Trolley wires, trolley feeder wires, and bare signal wires shall be insulated...

  4. Exotic Magnetic Orders and Their Interplay with Superconductivity

    DEFF Research Database (Denmark)

    Christensen, Morten Holm

    Superconductivity represents one of the most important scientific discoveries of the 20th century. The practical applications are numerous ranging from clean energy storage and MRI machines to quantum computers. However, the low temperatures required for superconductivity prohibits many practical...

  5. Navy superconductivity efforts

    Science.gov (United States)

    Gubser, D. U.

    1990-04-01

    Both the new high temperature superconductors (HTS) and the low temperature superconductors (LTS) are important components of Navy's total plan to integrate superconductivity into field operational systems. Fundamental research is an important component of the total Navy program and focuses on the HTS materials. Power applications (ship propulsion, etc.) use LTS materials while space applications (MMW electronics, etc.) use HTS materials. The Space Experiment being conducted at NRL will involve space flight testing of HTS devices built by industry and will demonstrate the ability to engineer and space qualify these devices for systems use. Another important component of the Navy's effort is the development of Superconducting Quantum Interference Device (SQUID) magnetometers. This program will use LTS materials initially, but plans to implement HTS materials as soon as possible. Hybrid HTS/LTS systems are probable in many applications. A review of the status of the Navy's HTS materials research is given as well as an update on the Navy's development efforts in superconductivity, with particular emphasis on the related SDIO sponsored program on HTS applications.

  6. Navy superconductivity efforts

    Science.gov (United States)

    Gubser, D. U.

    1990-01-01

    Both the new high temperature superconductors (HTS) and the low temperature superconductors (LTS) are important components of Navy's total plan to integrate superconductivity into field operational systems. Fundamental research is an important component of the total Navy program and focuses on the HTS materials. Power applications (ship propulsion, etc.) use LTS materials while space applications (MMW electronics, etc.) use HTS materials. The Space Experiment being conducted at NRL will involve space flight testing of HTS devices built by industry and will demonstrate the ability to engineer and space qualify these devices for systems use. Another important component of the Navy's effort is the development of Superconducting Quantum Interference Device (SQUID) magnetometers. This program will use LTS materials initially, but plans to implement HTS materials as soon as possible. Hybrid HTS/LTS systems are probable in many applications. A review of the status of the Navy's HTS materials research is given as well as an update on the Navy's development efforts in superconductivity, with particular emphasis on the related SDIO sponsored program on HTS applications.

  7. Quantum Optics with Quantum Dots in Photonic Wires: Basics and Application to “Ultrabright” Single Photon Sources

    DEFF Research Database (Denmark)

    Gérard, J. M.; Claudon, J.; Bleuse, J.

    2011-01-01

    We review recent experimental and theoretical results, which highlight the strong interest of the photonic wire (PW) geometry for quantum optics experiments with solid-state emitters, and for quantum optoelectronic devices. By studying single InAs QDs embedded within single-mode cylindrical GaAs PW......, we have noticeably observed a very strong (16 fold) inhibition of their spontaneous emission rate in the thin-wire limit, and a nearly perfect funnelling of their spontaneous emission into the guided mode for larger PWs. We present a novel single -photon-source based on the emission of a quantum dot...... embedded in an engineered PW, comprising a tapered tip so as to control the radiation pattern, and an integrated hybrid bottom mirror. Unlike microcavity-based devices, this source displays for the first time simultaneously a record-high efficiency (0.73 photon per pulse) and a very low g(2) parameter...

  8. Oak Ridge National Laboratory (ORNL) Superconducting Technology Program for electric power systems. Annual report for FY 1994

    Energy Technology Data Exchange (ETDEWEB)

    Koncinski, W.S. [ed.; Hawsey, R.A. [comp.

    1994-12-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy`s Office of Energy Efficiency and Renewable Energy to develop the technology base needed by US industry for commercial development of electric power applications of high-temperature superconductivity. The three major elements of this program are conductor development, applications development, and the Superconductivity Partnership Initiative. 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 1994 Annual Program Review held July 19--20, 2994. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to industrial competitiveness projects with private companies. 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 with US 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 products.

  9. Exotic Magnetic Orders and Their Interplay with Superconductivity

    DEFF Research Database (Denmark)

    Christensen, Morten Holm

    applications. The more recent discovery of high-temperature superconductors, with superconducting transition temperatures above 100~K, has led to the hope that superconductivity at room-temperature might be achievable, although a complete theoretical understanding of the high-temperature superconductors......Superconductivity represents one of the most important scientific discoveries of the 20th century. The practical applications are numerous ranging from clean energy storage and MRI machines to quantum computers. However, the low temperatures required for superconductivity prohibits many practical...

  10. Unconventional superconductivity near inhomogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Poenicke, A.F.

    2008-01-25

    After the presentation of a quasi-classical theory the specific heat of Sr{sub 2}RuO{sub 4} is considered. Then tunneling spectroscopy on cuprate superconductors is discussed. Thereafter the subharmonic gap structure in d-wave superconductors is considered. Finally the application of the S-matrix in superconductivity is discussed with spin mixing, CrO{sub 2} as example, and an interface model. (HSI)

  11. US Navy superconductivity program

    Science.gov (United States)

    Gubser, Donald U.

    1991-01-01

    Both the new high temperature superconductors (HTS) and the low temperature superconductors (LTS) are important components of the Navy's total plan to integrate superconductivity into field operational systems. Fundamental research is an important component of the total Navy program and focuses on the HTS materials. Power applications (ship propulsion) use LTS materials while space applications (millimeter wave electronics) use HTS materials. The Space Experiment to be conducted at NRL will involve space flight testing of HTS devices built by industry and will demonstrate the ability to engineer and space qualify these devices for systems use. Another important component of the Navy's effort is the development of Superconducting Quantum Interference Device (SQUID) magnetometers. This program will use LTS materials initially, but plans to implement HTS materials as soon as possible. Hybrid HTS/LTS systems are probable in many applications. A review of the status of the Navy's HTS materials research is given as well as an update on the Navy's development efforts in superconductivity.

  12. Superconductivity in all its states

    CERN Multimedia

    Globe Info

    2011-01-01

    Temporary exhibition at the Saint-Genis-Pouilly Tourist Office. For the 100th anniversary of its discovery, take a plunge into the amazing world of superconductivity. Some materials, when cooled down to extreme temperatures, acquire a remarkable property -  they become superconducting. Superconductivity is a rare example of a quantum effect that can be witnessed on the macroscopic scale and is today at the heart of much research. In laboratories, researchers try to gain a better understanding of its origins, study new superconducting materials, explore the phenomenon at the nanometric scale and pursue their indefatigable search for new applications. Monday to Friday: 09:00 a.m. to 12:00 and 2:30 p.m. to 6:30 p.m. Saturday: 10:00 a.m. to 12:00 noon » Open to all – Admission free For further information: +33 (0)4 50 42 29 37

  13. Electromagnetic Behaviour of Metallic Wire Structures

    CERN Document Server

    Chui, S T

    2013-01-01

    Despite the recent development and interest in the photonics of metallic wire structures, the relatively simple concepts and physics often remain obscured or poorly explained to those who do not specialize in the field. Electromagnetic Behaviour of Metallic Wire Structures provides a clear and coherent guide to understanding these phenomena without excessive numerical calculations.   Including both background material and detailed derivations of the various different formulae applied, Electromagnetic Behaviour of Metallic Wire Structures describes how to extend basic circuit theory relating to voltages, currents, and resistances of metallic wire networks to include situations where the currents are no longer spatially uniform along the wire. This lays a foundation for a deeper understanding of the many new phenomena observed in meta-electromagnetic materials.   Examples of applications are included to support this new approach making Electromagnetic Behaviour of Metallic Wire Structures a comprehensive and ...

  14. Tensile deformation of NiTi wires.

    Science.gov (United States)

    Gall, Ken; Tyber, Jeff; Brice, Valerie; Frick, Carl P; Maier, Hans J; Morgan, Neil

    2005-12-15

    We examine the structure and properties of cold drawn Ti-50.1 at % Ni and Ti-50.9 at % Ni shape memory alloy wires. Wires with both compositions possess a strong fiber texture in the wire drawing direction, a grain size on the order of micrometers, and a high dislocation density. The more Ni rich wires contain fine second phase precipitates, while the wires with lower Ni content are relatively free of precipitates. The wire stress-strain response depends strongly on composition through operant deformation mechanisms, and cannot be explained based solely on measured differences in the transformation temperatures. We provide fundamental connections between the material structure, deformation mechanisms, and resulting stress-strain responses. The results help clarify some inconsistencies and common misconceptions in the literature. Ramifications on materials selection and design for emerging biomedical applications of NiTi shape memory alloys are discussed.

  15. A novel no-insulation winding technique of high temperature-superconducting racetrack coil for rotating applications: A progress report in Korea university

    Science.gov (United States)

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

    2016-10-01

    This paper presents our recent progress on core technology development for a megawatt-class superconducting wind turbine generator supported by the international collaborative R&D program of the Korea Institute of Energy Technology Evaluation and Planning. To outperform the current high-temperature-superconducting (HTS) magnet technology in the wind turbine industry, a novel no-insulation winding technique was first proposed to develop the second-generation HTS racetrack coil for rotating applications. Here, we briefly report our recent studies on no-insulation (NI) winding technique for GdBCO coated conductor racetrack coils in the following areas: (1) Charging-discharging characteristics of no-insulation GdBCO racetrack coils with respect to external pressures applied to straight sections; (2) thermal and electrical stabilities of no-insulation GdBCO racetrack coils encapsulated with various impregnating materials; (3) quench behaviors of no-insulation racetrack coils wound with GdBCO conductor possessing various lamination layers; (4) electromagnetic characteristics of no-insulation GdBCO racetrack coils under time-varying field conditions. Test results confirmed that this novel NI winding technique was highly promising. It could provide development of a compact, mechanically dense, and self-protecting GdBCO magnet for use in real-world superconducting wind turbine generators.

  16. Application of a modified flux-coupling type superconducting fault current limiter to transient performance enhancement of micro-grid

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Lei, E-mail: stclchen1982@163.com [School of Electrical Engineering, Wuhan University, Wuhan 430072 (China); Zheng, Feng; Deng, Changhong; Li, Shichun; Li, Miao; Liu, Hui [School of Electrical Engineering, Wuhan University, Wuhan 430072 (China); Zhu, Lin [Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville 37996 (United States); Guo, Fang [Department of Substation, Guang Dong Electric Power Design Institute, Guangzhou 510663 (China)

    2015-11-15

    Highlights: • A modified flux-coupling type SFCL is suggested to enhance the transient performance of a micro-grid. • The SFCL’s main contribution is to improve the micro-grid’s fault ride-through capability. • The SFCL also can make the micro-grid carry out a smooth transition between its grid-connected and islanded modes. • The simulations show that the SFCL can availably strengthen the micro-grid’s voltage and frequency stability. - Abstract: Concerning the application and development of a micro-grid system which is designed to accommodate high penetration of intermittent renewable resources, one of the main issues is related to an increase in the fault-current level. It is crucial to ensure the micro-grid’s operational stability and service reliability when a fault occurs in the main network. In this paper, our research group suggests a modified flux-coupling type superconducting fault current limiter (SFCL) to enhance the transient performance of a typical micro-grid system. The SFCL is installed at the point of common coupling (PCC) between the main network and the micro-grid, and it is expected to actively improve the micro-grid’s fault ride-through capability. And for some specific faults, the micro-grid should disconnect from the main network, and the SFCL’s contribution is to make the micro-grid carry out a smooth transition between its grid-connected and islanded modes. Related theory derivation, technical discussion and simulation analysis are performed. From the demonstrated results, applying the SFCL can effectively limit the fault current, maintain the power balance, and enhance the voltage and frequency stability of the micro-grid.

  17. Color superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Wilczek, F. [Institute for Advanced Study, Princeton, NJ (United States)

    1997-09-22

    The asymptotic freedom of QCD suggests that at high density - where one forms a Fermi surface at very high momenta - weak coupling methods apply. These methods suggest that chiral symmetry is restored and that an instability toward color triplet condensation (color superconductivity) sets in. Here I attempt, using variational methods, to estimate these effects more precisely. Highlights include demonstration of a negative pressure in the uniform density chiral broken phase for any non-zero condensation, which we take as evidence for the philosophy of the MIT bag model; and demonstration that the color gap is substantial - several tens of MeV - even at modest densities. Since the superconductivity is in a pseudoscalar channel, parity is spontaneously broken.

  18. SUPERCONDUCTING PHOTOCATHODES.

    Energy Technology Data Exchange (ETDEWEB)

    SMEDLEY, J.; RAO, T.; WARREN, J.; SEKUTOWICZ, LANGNER, J.; STRZYZEWSKI, P.; LEFFERS, R.; LIPSKI, A.

    2005-10-09

    We present the results of our investigation of lead and niobium as suitable photocathode materials for superconducting RF injectors. Quantum efficiencies (QE) have been measured for a range of incident photon energies and a variety of cathode preparation methods, including various lead plating techniques on a niobium substrate. The effects of operating at ambient and cryogenic temperatures and different vacuum levels on the cathode QE have also been studied.

  19. Superconductivity applications for infrared and microwave devices II; Proceedings of the Meeting, Orlando, FL, Apr. 4, 5, 1991

    Science.gov (United States)

    Heinen, Vernon O. (Editor); Bhasin, Kul B. (Editor)

    1991-01-01

    Topics discussed include thin-film technology, microwave transmission lines and resonators, microwave devices and circuits, infrared detectors and bolometers, and superconducting junctions. Papers are presented on possible enhancement in bolometric response using free-standing film of YBa2Cu3O(x), aging and surface instability in high-Tc superconductors, epitaxial Tl2Ba2CaCu2O8 thin films on LaAlO3 and their microwave device properties, the performance of stripline resonators using sputtered YBCO films, and a coplanar waveguide microwave filter of YBa2Cu3O7. Attention is also given to the performance characteristics of Y-Ba-Cu-O microwave superconducting detectors, high-Tc bolometer developments for planetary missions, infrared detectors from YBaCuO thin films, high-temperature superconductor junction technology, and submillimeter receiver components using superconducting tunnel junctions.

  20. Advances in superconductivity; Proceedings of the First International Symposium on Superconductivity (ISS '88), Nagoya, Japan, Aug. 28-31, 1988

    Science.gov (United States)

    Kitazawa, Koichi; Ishiguro, Takehiko

    Papers on superconductivity and superconductor applications are presented, covering topics such as electric power systems, magnetic energy storage, fusion power, magnetic resonance imaging, transportation, Josephson digital and analog devices with niobium junctions, Josephson parametric amplifiers, and organic superconductors. Topics related to oxide superconductors include superconductor mechanisms, crystal chemistry, electronic structure, phase diagrams, crystal growth, processing, microstructure, tapes and thick films, wires, and coils. Other topics include coherence length, magnetic properties, critical current, irradiation effect, thin film processing, chemical reactions and superconductor/substrate interaction, tunneling and tunneling junction, Bi- and Tl-based cuprate superconductors, the 110 K phase of Bi-Sr-Ca-Cu-O fabrication and microstructure, research policies, and trends in technology.

  1. Vortex dynamics in superconducting MgB2 and prospects for applications.

    Science.gov (United States)

    Bugoslavsky, Y; Perkins, G K; Qi, X; Cohen, L F; Caplin, A D

    2001-03-29

    The recently discovered superconductor magnesium diboride, MgB2, has a transition temperature, Tc, approaching 40 K, placing it intermediate between the families of low- and high-temperature superconductors. In practical applications, superconductors are permeated by quantized vortices of magnetic flux. When a supercurrent flows, there is dissipation of energy unless these vortices are 'pinned' in some way, and so inhibited from moving under the influence of the Lorentz force. Such vortex motion ultimately determines the critical current density, Jc, which the superconductor can support. Vortex behaviour has proved to be more complicated in high-temperature superconductors than in low-temperature superconductors and, although this has stimulated extensive theoretical and experimental research, it has also impeded applications. Here we describe the vortex behaviour in MgB2, as reflected in Jc and in the vortex creep rate, S, the latter being a measure of how fast the 'persistent' supercurrents decay. Our results show that naturally occurring grain boundaries are highly transparent to supercurrents, a desirable property which contrasts with the behaviour of the high-temperature superconductors. On the other hand, we observe a steep, practically deleterious decline in Jc with increasing magnetic field, which is likely to reflect the high degree of crystalline perfection in our samples, and hence a low vortex pinning energy.

  2. High-temperature superconducting current leads for micro-SMES application

    Science.gov (United States)

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

    1994-07-01

    SMES is being applied on a microscale (1-10 MJ stored energy) to improve electrical power quality. A major portion of the SMES refrigeration load is for cooling the conventional (copper, vapor-cooled) current leads that transfer energy between the magnet and the power-conditioning equipment. The lead refrigeration load can be reduced significantly by the use of high-temperature superconductors (HTSs). An HTS current lead suitable for micro-SMES application has been designed. The lower stage of the lead employs HTSs. A transition between the lower stage and the conventional upper-stage lead is heat-intercepted by a cryocooler. Details of the design are presented. Construction and operating experiences are discussed.

  3. New Applications of Magnetic Separation Using Superconducting Magnets and Colloid Chemical Processes

    Science.gov (United States)

    Takeda, S.; Yu, S.-J.; Nakahira, A.; Izumi, Y.; Nishijima, S.; Watanabe, T.

    2005-07-01

    High gradient magnetic separation (HGMS) can be a promising new environmental purification technique as it produces no contaminants, such as flocculants, and could possibly treat large amounts of waste water within a short time frame. A colloid chemical process for magnetic seeding can allow us to rapidly recover a large quantity of adsorbate and to strongly magnetize individual particles in order to improve the recovery efficiency of magnetic separation. In this paper, we will report on the fundamental study of the magnetic seeding process and purification processes using HGMS, and also on studies of applications of the water treatment system for actual factories. Emphasized is a report on a system constructed for water treatment from a paper-manufacturing factory.

  4. Beating liquid helium: the technologies of cryogen-free superconducting magnets

    Science.gov (United States)

    Burgoyne, John

    2015-03-01

    Cryogen-free superconducting magnets have been available now for almost 15 years, but have only become standard commercial products in more recent years. In this review we will consider the pros and cons of ``dry'' design including superconducting wire development and selection, thermal budgeting, and the alternative methods for achieving magnet cooling.

  5. The clinical application of direct bonding fixed retaining wire.%直接粘接式固定保持弓丝的临床应用

    Institute of Scientific and Technical Information of China (English)

    李雪琦; 刘进

    2001-01-01

    目的:介绍直接粘接式固定保持弓丝的材料及临床应用中的使用方法和效果。方法:使用3MUnitek公司所生产的固定保持器套件。按光固材料的使用步骤,将弓丝粘到牙列片段的唇侧及舌侧。结果:32例病例中,保持期最长1.5a,最短1a,8人次因材料部分脱落而需重新粘接,6个病例保持结束时覆牙 合覆盖近Ⅱ度。26例保持良好的矫治效果。表明此种保持器是一种效果稳定、操作简便、美观的保持器。结论:固定保持器是一种稳定、有效和美观的保持方法。%Objective:To introduce fixed retaining wire materials,applyingmethod and clinical effects.Methods:The fixed retaining kits made in 3MUnitek Co. were used.The wire was bonded with directly bonding technique to the labial or lingual surfaces of teeth according to the application steps of light-cure material.The longest retaining period was 1.5 years,and the shortest one was 1 year.Results:The results showed that among 32 cases there were 8 times of rebonding due to the wire bonding failure.The overbite and over jet of six cases increased about two degree when the retention finished.26 cases maintained fine effect.Conclusions:The fixed retaining appliance is stable,effective and aesthetic.

  6. Structures and superconducting propertied of RHQT-Processed Nb{sub 3}Al multifilamentary wires; Kyunetsu kyurei{center_dot}hentai ho Nb{sub 3}Al tashin senzai no soshiki to chodendo tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, A.; Iijima, Y.; Inoue, K. [National Research Institute for Metals, Tokyo (Japan)

    2000-05-29

    Pinning point of Nb{sub 3}Al wire with superior J{sub c}-B property obtained by rapid heating/quenching and transforming method was examined. Structures obtained additional heat treatment at 800 degrees of centigrade for 12 h after rapid heating/quenching at various maximum attained temperatures were examined. As the result, it was found that in formed A15 phase by transforming of supersaturated solid solution, many defects existed with hierarchical structure consisting of laminated defects (10-20 nm), small tilt sub-grain boundary (about 100 nm) and large tilt crystalline grain boundary (about 1 {mu}m). The possibility that this laminated defects is a pinning point is high. (NEDO)

  7. Application of Rapid Prototyping and Wire Arc Spray to the Fabrication of Injection Mold Tools (MSFC Center Director's Discretionary Fund)

    Science.gov (United States)

    Cooper, K. G.

    2000-01-01

    Rapid prototyping (RP) is a layer-by-layer-based additive manufacturing process for constructing three-dimensional representations of a computer design from a wax, plastic, or similar material. Wire arc spray (WAS) is a metal spray forming technique, which deposits thin layers of metal onto a substrate or pattern. Marshall Space Flight Center currently has both capabilities in-house, and this project proposed merging the two processes into an innovative manufacturing technique, in which intermediate injection molding tool halves were to be fabricated with RP and WAS metal forming.

  8. Superconducting fault current limiter for railway transport

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, L. M., E-mail: LMFisher@niitfa.ru; Alferov, D. F.; Akhmetgareev, M. R.; Budovskii, A. I.; Evsin, D. V.; Voloshin, I. F.; Kalinov, A. V. [National Technical Physics and Automation Research Institute (Russian Federation)

    2015-12-15

    A resistive switching superconducting fault current limiter (SFCL) for DC networks with voltage of 3.5 kV and nominal current of 2 kA is developed. The SFCL consists of two series-connected units: block of superconducting modules and high-speed vacuum breaker with total disconnection time not more than 8 ms. The results of laboratory tests of superconducting SFCL modules in current limiting mode are presented. The recovery time of superconductivity is experimentally determined. The possibility of application of SFCL on traction substations of Russian Railways is considered.

  9. Tunable superconducting nanoinductors

    Energy Technology Data Exchange (ETDEWEB)

    Annunziata, Anthony J; Santavicca, Daniel F; Frunzio, Luigi; Rooks, Michael J; Prober, Daniel E [Department of Applied Physics, Yale University, New Haven, CT 06511 (United States); Catelani, Gianluigi [Department of Physics, Yale University, New Haven, CT 06511 (United States); Frydman, Aviad, E-mail: anthony.annunziata@yale.edu, E-mail: daniel.prober@yale.edu [Department of Physics, Bar-Ilan University, Ramat Gan 52900 (Israel)

    2010-11-05

    We characterize inductors fabricated from ultra-thin, approximately 100 nm wide strips of niobium (Nb) and niobium nitride (NbN). These nanowires have a large kinetic inductance in the superconducting state. The kinetic inductance scales linearly with the nanowire length, with a typical value of 1 nH {mu}m{sup -1} for NbN and 44 pH {mu}m{sup -1} for Nb at a temperature of 2.5 K. We measure the temperature and current dependence of the kinetic inductance and compare our results to theoretical predictions. We also simulate the self-resonant frequencies of these nanowires in a compact meander geometry. These nanowire inductive elements have applications in a variety of microwave frequency superconducting circuits.

  10. ORNL superconducting technology program for electric power systems. Annual report for FY 1993

    Energy Technology Data Exchange (ETDEWEB)

    Hawsey, R.A. [comp.

    1994-04-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy`s Office of Energy Efficiency 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 conductor 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 information prepared for the FY 1993 Annual Program Review held July 28--29, 1993. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to industrial competitiveness projects with private companies. 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 rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high-temperature superconductor wire and wire products.

  11. A high T{sub c} superconducting loss-free resistor

    Energy Technology Data Exchange (ETDEWEB)

    Jin, J. X.; Chen, J. Y.; Dou, S. X. [University of Wollongong, Wollongong, NSW (Australia). Center for Superconducting and Electronic Materials

    1996-12-31

    Full text: A loss-less resistor (LLR) is introduced as a novel concept with consideration of using a high T{sub c} superconducting (HTS) inductor. This LLR resistor mainly consists of an electronic switch bridge and a inductor L. By controlling the electronic switch bridge, an equivalent resistance R(i) can be generated, and its value is R(i) = (L/i)di/dt, which allows the LLR resistor have a resistive voltage-current characteristic i.e. V(t) = i(t)R, but without thermal loss across this LLR resistor if a superconducting inductor is selected. With a HTS winding and therefore a HTS inductor, this LLR resistor is practically close to loss-free. The LLR resistor can be widely used to replace the conventional resistor in order to save energy and to improve performance of the systems. The HTS wires are identified for this application, by considering their critical currents, ac loss and possibility to make a large HTS inductor winding. To make LLR resistors for practical applications is considered with the existing HTS wires

  12. ORNL superconducting technology program for electric power systems. Annual report for FY 1993

    Energy Technology Data Exchange (ETDEWEB)

    Hawsey, R.A. [comp.

    1994-04-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy`s Office of Energy Efficiency 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 conductor 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 information prepared for the FY 1993 Annual Program Review held July 28--29, 1993. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to industrial competitiveness projects with private companies. 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 rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high-temperature superconductor wire and wire products.

  13. Antiferromagnetism, f -wave, and chiral p -wave superconductivity in a kagome lattice with possible application to s d2 graphenes

    Science.gov (United States)

    Wang, Wan-Sheng; Liu, Yuan-Chun; Xiang, Yuan-Yuan; Wang, Qiang-Hua

    2016-07-01

    We investigate the electronic instabilities in a kagome lattice with Rashba spin-orbital coupling by the unbiased singular-mode functional renormalization group. At the parent 1 /3 filling, the normal state is a quantum spin Hall system. Since the bottom of the conduction band is near the van Hove singularity, the electron-doped system is highly susceptible to competing orders upon electron interactions. The topological nature of the parent system enriches the complexity and novelty of such orders. We find 120∘-type intra-unit-cell antiferromagnetic order, f -wave superconductivity, and chiral p -wave superconductivity with increasing electron doping above the van Hove point. In both types of superconducting phases, there is a mixture of comparable spin singlet and triplet components because of the Rashba coupling. The chiral p -wave superconducting state is characterized by a Chern number Z =1 , supporting a branch of Weyl fermion states on each edge. The model bares close relevance to the so-called s d2 graphenes proposed recently.

  14. Soft magnetic wires

    Science.gov (United States)

    Vázquez, M.

    2001-06-01

    An overview of the present state of the art on the preparation techniques, outstanding magnetic properties and applications of soft magnetic micro and nanowires is presented. Rapid solidification techniques (in-rotating-water quenching and drawing methods) to fabricate amorphous microwires with diameter in the range from 100 down to 1 μm are first described. Electrodeposition is also employed to prepare composite microtubes (magnetic coatings) and to fill porous membranes (diameter of the order of 0.1 μm). Magnetic behaviours of interest are related to the different hysteresis loops of samples: square-shaped loops typical of bistable behaviour, and nearly non-hysteretic loop with well-defined transverse anisotropy field. The role played by magnetic dipolar interactions in the magnetic behaviour of arrays of micro and nanowires is described. A particular analysis is done on the giant magnetoimpedance (GMI) effect in the radio and microwave frequency ranges exhibited by ultrasoft microwires. Finally, a few examples of applications are introduced for magnetostrictive and non-magnetostrictive wires, they are: “magnetoelastic pens”, micromotors; DC current-sensors based on GMI, and sharpened amorphous wire tips in spin polarised scanning tunneling microscopy.

  15. 17th International Conference on RF Superconductivity

    CERN Document Server

    2015-01-01

    RF superconductivity is the key technology of accelerators for particle physics, nuclear physics and light sources. SRF 2015 covered the latest advances in the science, technology, and applications of superconducting RF. There was also an industrial exhibit during the conference with the key vendors in the community available to discuss their capabilities and products.

  16. 17th International Conference on RF Superconductivity

    CERN Document Server

    Laxdal, Robert E.; Schaa, Volker R.W.

    2015-01-01

    RF superconductivity is the key technology of accelerators for particle physics, nuclear physics and light sources. SRF 2015 covered the latest advances in the science, technology, and applications of superconducting RF. There was also an industrial exhibit during the conference with the key vendors in the community available to discuss their capabilities and products.

  17. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sakai, S

    1998-01-01

    We derive an analytical solution for the Josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low-T-c systems with magnetic coupling between the superconducting layers. but many features of our results are more general, and thus an application...

  18. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig

    1999-01-01

    We derive an analytical solution for the josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low T-c systems with magnetic coupling between the superconducting layers, but many features of our results are more general, and thus an application...

  19. 医疗仪器导联线收纳箱的设计与应用%Design and Application of a Medical Instrument Lead Wire Storage Box

    Institute of Scientific and Technical Information of China (English)

    王青丽; 向克兰; 屈红; 徐雯; 谢芬高; 张强; 刁丽

    2016-01-01

    This paper illustrated the design and application process of a medical instrument lead wire storage box, which consists of a cube box, U-shaped groove, box door, snap hooks, handles and other structures. It could quickly lead to many groups of fixed lines classified in the storage box so as to solve the problem of lead wires twisted, folded and wrapped with damage because of multiple sets of unattended medical equipment. Altogether 400 patients who were treated in Department of Emergency in the hospital in January 2014 were selected and divided into Fixation Group and Storage Box Group evenly. The lead wires of ECG monitors in Fixation Group were fixed with self-made fixation band;while, the lead wires of ECG monitors in Storage Box Group were fixed with the storage box designed in this paper. According to the statistical comparison results, Storage Box Group showed shorter lead wire placement time and lower lead wire replacement rate as well as superiorities in instrument complete and clean condition assessment and medical staff’s satisfaction degree, with statistically significant difference (P<0.05). The device designed in this paper was featured with great practicability and convenience, which attained the design objects and deserved wider promotion.%本文阐述了一种医疗仪器导联线收纳箱的设计与应用过程,该装置主要由正方体箱体、U型凹槽、箱门、卡扣挂钩、提手等结构组成,能够快速将多组导联线分类固定于收纳箱中,解决了临床上医疗仪器多组导联线随意放置致导联线扭曲、折叠及缠绕与损坏等问题。选取我院急诊科2014年1月收治的患者400名,平均分为两组(固定组和收纳箱组)。固定组心电监护仪使用后采用自制固定带将导联线缠绕固定,收纳箱组心电监护仪使用后采用本文研制的医疗仪器导联线收纳箱将导联线收纳固定。统计对比结果表明,收纳箱组心电监护仪导联线安放

  20. The advantages and challenges of superconducting magnets in particle therapy

    Science.gov (United States)

    Gerbershagen, Alexander; Calzolaio, Ciro; Meer, David; Sanfilippo, Stéphane; Schippers, Marco

    2016-08-01

    This paper provides an overview of the current developments in superconducting magnets for applications in proton and ion therapy. It summarizes the benefits and challenges regarding the utilization of these magnets in accelerating systems (e.g. superconducting cyclotrons) and gantries. The paper also provides examples of currently used superconducting particle therapy systems and proposed designs.

  1. Development and testing of a 50 KA, pulsed superconducting cable

    Energy Technology Data Exchange (ETDEWEB)

    Wollan; DeClerc, J.; Hamilton, W.; Zeitlin, B.

    1983-05-01

    Prototype cables for 7.5 T, pulsed field application in tokamak poloidal field coils have been designed, fabricated, and evaluated. Successful fabrication of a 10 m superconducting sample represents the largest superconducting cable ever made. Details of the fabrication, the problems expected and encountered, and the solutions to those problems are discussed. Results of stability measurements on the superconducting prototype also are presented.

  2. 螺纹镶套技术在蒸汽发生器上的应用%Application of Thread Wire Technology in Steam Generator

    Institute of Scientific and Technical Information of China (English)

    杨正桓; 罗飞华; 王旭; 孙东

    2013-01-01

    简要介绍了钢丝螺套的特点,对它的力学特性进行了分析,阐释其在核电设备上的适用性,并从现场实际问题出发,找出了一套合适的方法,解决了蒸汽发生器人孔法兰螺纹孔出现的问题,最后通过试验,对螺纹镶套技术的效果进行了验证。该技术的成功应用,为核电领域的相关单位处理类似问题提供了借鉴。%The characteristic of the thread wire was briefly introduced ,and also its mechanical properties were analyses .Then the problem of thread holes in the steam generator was solved by adopting suitable method.Finally,the effect of thread wire is verified by experiments .The successful application will pro-vide a good reference for other nuclear power units dealing with similar problems .

  3. Deterministic phase slips in mesoscopic superconducting rings

    Science.gov (United States)

    Petković, I.; Lollo, A.; Glazman, L. I.; Harris, J. G. E.

    2016-11-01

    The properties of one-dimensional superconductors are strongly influenced by topological fluctuations of the order parameter, known as phase slips, which cause the decay of persistent current in superconducting rings and the appearance of resistance in superconducting wires. Despite extensive work, quantitative studies of phase slips have been limited by uncertainty regarding the order parameter's free-energy landscape. Here we show detailed agreement between measurements of the persistent current in isolated flux-biased rings and Ginzburg-Landau theory over a wide range of temperature, magnetic field and ring size; this agreement provides a quantitative picture of the free-energy landscape. We also demonstrate that phase slips occur deterministically as the barrier separating two competing order parameter configurations vanishes. These results will enable studies of quantum and thermal phase slips in a well-characterized system and will provide access to outstanding questions regarding the nature of one-dimensional superconductivity.

  4. Electromagnetic radiation of superconducting cosmic strings

    Science.gov (United States)

    Rogozin, D. A.; Zadorozhna, L. V.

    2013-12-01

    Cosmic strings are relics of the early Universe which can be formed during the phase transitions of fields with spontaneously broken symmetry in the early Universe. Their existence finds support in modern superstrings theories, both in compactification models and in theories with extended additional dimensions. Strings can hold currents, effectively become electrically superconducting wires of astrophysical dimensions. Superconducting cosmic strings can serve as powerful sources of non-thermal radiation in wide energy range. Mechanisms of radiation are synchrotron, synchrotron self-Compton and inverse-Compton on CMB photons radiation of electrons accelerated by bow shock wave, created by magnetosphere of relativistically moving string in intergalactic medium (IGM). Expected fluxes of radiation from the shocked plasma around superconducting cosmic strings are calculated for strings with various tensions and for different cases of their location. Possibilities of strings detection by existing facilities are estimated.

  5. New Fast Response Thin Film-Based Superconducting Quench Detectors

    CERN Document Server

    Dudarev, A; van de Camp, W; Ravaioli, E; Teixeira, A; ten Kate, H H J

    2014-01-01

    Quench detection on superconducting bus bars and other devices with a low normal zone propagation velocity and low voltage build-up is quite difficult with conventional quench detection techniques. Currently, on ATLAS superconducting bus bar sections, superconducting quench detectors (SQD) are mounted to detect quench events. A first version of the SQD essentially consists of an insulated superconducting wire glued to a superconducting bus line or windings, which in the case of a quench rapidly builds up a relatively high resistance that can be easily and quietly detected. We now introduce a new generation of drastically improved SQDs. The new version makes the detection of quenches simpler, more reliable, and much faster. Instead of a superconducting wire, now a superconducting thin film is used. The layout of the sensor shows a meander like pattern that is etched out of a copper coated 25 mu m thick film of Nb-Ti glued in between layers of Kapton. Since the sensor is now much smaller and thinner, it is easi...

  6. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  7. Niobium Titanium and Copper wire samples

    CERN Multimedia

    2009-01-01

    A comparison of the LHC magnet wire that carries 13kA and the equivalent in copper that would be needed to carry such a current. About LHC superconducting wiring: The high magnetic fields needed for the LHC can only be reached using superconductors. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC will be the largest superconducting installation ever built and, at 1.9 degrees above absolute zero (300 degrees below room temperature), one of the the coldest objects in the universe! Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9000 niobium–titanium filaments ten times finer than a hair. The cables carry up to 12 500 amps and must withstand enormous electromagnetic forces. At full field, the force on one metre of magnet is comparable to the weight of a jumbo jet. Coil winding requires great care to prevent movements as the field changes. Friction can create hot spots which “quench” the mag...

  8. High field performance of superconducting magnets using powder metallurgy processed Cu-Nb-Sn and Nb-Al

    Energy Technology Data Exchange (ETDEWEB)

    Zaleski, A.J.; Foner, S.

    1984-06-01

    Small superconducting magnets were fabricated with powder metallurgy processed Nb-Al wire and with powder metallurgy processed multistrand Cu-Nb--Sn wire with 19 tin cores. Tests in a background field of up to 15 T showed that short sample characteristics were achieved for three coils. Upper limits of resistivity were established for both powder metallurgy processed wires. The reacted wires in the magnets gave upper limits of resistivity at 10 T of less than 1.4 x 10/sup -14/ ..cap omega.. cm for the Nb/sub 3/Sn wire, and less than 9 x 10/sup -13/ ..cap omega.. cm for the Nb-Al wire.

  9. Design and application of LT17/360 wet wire drawing machine spool wire arrangement mechanism%LT17/360水箱拉丝机工字轮排线机构设计与应用

    Institute of Scientific and Technical Information of China (English)

    肖云霞; 何吉林

    2013-01-01

    To solve the problem of wire arranging quality occurred in process of steel wire winding on spool take-up and supplying to strands and rope,combining the characteristics of three spool wire arrangement mechanism used recently,LT17/360 wet wire drawing machine spool wire arrangement mechanism of take-up diameter 0.5 ~ 0.9 mm after steel wire drawing was designed.The double thread screw wire arrangement mechanism was adopted,to choose pitch was 18 mm,screw rod pitch diameter was 30 mm,take-up machine deployed three-phase torque motor to control the spool speed,added a gear box to adjust speed ratio,to meet screw speed and steel wire spacing.The mechanism is simple structure and easy to manufacture,convenient to maintenance,it makes the wire arrangement uniformly,enables the spool to get a constant offtension in strands and rope use,solves the problem of line collapse,pull off and twist standing waves,the laying quality of strands is improved.%为解决钢丝在工字轮收线缠绕过程中出现的排线质量以及股绳供料中的问题,结合现使用的3种工字轮排线机构的特点,设计一种钢丝拉拔后收线直径为0.5 ~0.9 mm的LT17/360水箱拉丝机工字轮排线装置.采用双向螺纹丝杆排线机构,选取螺距为18 mm,丝杆中径为30 mm;收线机采用三相力矩电机控制工字轮转速,增设一个减速箱调整速比,满足丝杆转速和钢丝的排线间距.该机构结构简单,制造和维修方便,收线工字轮排线均匀,工字轮在股绳使用时能获得较恒定的放线张力,解决了工字轮放线时发生垮线、拉断、捻合股起浪的问题,提高股的捻制质量.

  10. Wire harness twisting aid

    Science.gov (United States)

    Casey, E. J.; Commadore, C. C.; Ingles, M. E.

    1980-01-01

    Long wire bundles twist into uniform spiral harnesses with help of simple apparatus. Wires pass through spacers and through hand-held tool with hole for each wire. Ends are attached to low speed bench motor. As motor turns, operator moves hand tool away forming smooth twists in wires between motor and tool. Technique produces harnesses that generate less radio-frequency interference than do irregularly twisted cables.

  11. Operation of a superconducting nanowire quantum interference device with mesoscopic leads

    Science.gov (United States)

    Pekker, David; Bezryadin, Alexey; Hopkins, David S.; Goldbart, Paul M.

    2005-09-01

    A theory describing the operation of a superconducting nanowire quantum interference device (NQUID) is presented. The device consists of a pair of thin-film superconducting leads connected by a pair of topologically parallel ultranarrow superconducting wires. It exhibits intrinsic electrical resistance, due to thermally activated dissipative fluctuations of the superconducting order parameter. Attention is given to the dependence of this resistance on the strength of an externally applied magnetic field aligned perpendicular to the leads, for lead dimensions such that there is essentially complete and uniform penetration of the leads by the magnetic field. This regime, in which at least one of the lead dimensions—length or width—lies between the superconducting coherence and penetration lengths, is referred to as the mesoscopic regime. The magnetic field causes a pronounced oscillation of the device resistance, with a period not dominated by the Aharonov-Bohm effect through the area enclosed by the wires and the film edges but, rather, in terms of the geometry of the leads, in contrast to the well-known Little-Parks resistance of thin-walled superconducting cylinders. A detailed theory, encompassing this phenomenology quantitatively, is developed through extensions, to the setting of parallel superconducting wires, of the Ivanchenko-Zil’berman-Ambegaokar-Halperin theory of intrinsic resistive fluctuations in a current-biased Josephson junction and the Langer-Ambegaokar-McCumber-Halperin theory of intrinsic resistive fluctuations in a superconducting wire. In particular, it is demonstrated that via the resistance of the NQUID, the wires act as a probe of spatial variations in the superconducting order parameter along the perimeter of each lead: in essence, a superconducting phase gradiometer.

  12. Nano-storage wires.

    Science.gov (United States)

    Lee, Dong Jun; Kim, Eunji; Kim, Daesan; Park, Juhun; Hong, Seunghun

    2013-08-27

    We report the development of "nano-storage wires" (NSWs), which can store chemical species and release them at a desired moment via external electrical stimuli. Here, using the electrodeposition process through an anodized aluminum oxide template, we fabricated multisegmented nanowires composed of a polypyrrole segment containing adenosine triphosphate (ATP) molecules, a ferromagnetic nickel segment, and a conductive gold segment. Upon the application of a negative bias voltage, the NSWs released ATP molecules for the control of motor protein activities. Furthermore, NSWs can be printed onto various substrates including flexible or three-dimensional structured substrates by direct writing or magnetic manipulation strategies to build versatile chemical storage devices. Since our strategy provides a means to store and release chemical species in a controlled manner, it should open up various applications such as drug delivery systems and biochips for the controlled release of chemicals.

  13. Water Desalination with Wires

    NARCIS (Netherlands)

    Porada, S.; Sales, B.B.; Hamelers, H.V.M.; Biesheuvel, P.M.

    2012-01-01

    We show the significant potential of water desalination using a novel capacitive wire-based technology in which anode/cathode wire pairs are constructed from coating a thin porous carbon electrode layer on top of electrically conducting rods (or wires). By alternately dipping an array of electrode

  14. Singularities, swallowtails and Dirac points. An analysis for families of Hamiltonians and applications to wire networks, especially the Gyroid

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, Ralph M.; Khlebnikov, Sergei; Wehefritz-Kaufmann, Birgit

    2012-08-15

    Motivated by the Double Gyroid nanowire network we develop methods to detect Dirac points and classify level crossings, aka. singularities in the spectrum of a family of Hamiltonians. The approach we use is singularity theory. Using this language, we obtain a characterization of Dirac points and also show that the branching behavior of the level crossings is given by an unfolding of A{sub n} type singularities. Which type of singularity occurs can be read off a characteristic region inside the miniversal unfolding of an A{sub k} singularity. We then apply these methods in the setting of families of graph Hamiltonians, such as those for wire networks. In the particular case of the Double Gyroid we analytically classify its singularities and show that it has Dirac points. This indicates that nanowire systems of this type should have very special physical properties.

  15. Wire Bonder: Kulicke and Soffa Model 4526

    Data.gov (United States)

    Federal Laboratory Consortium — Description:CORAL Name: Wire BonderNeeds Description.Scientific Opportunities / Applications:Wedge bonderSemi-automatic and manual modesIndependent Z-axis control,...

  16. ZGS roots of superconductivity: People and devices

    Energy Technology Data Exchange (ETDEWEB)

    Pewitt, E.G.

    1994-12-31

    The ZGS community made basic contributions to the applications of superconducting magnets to high energy physics as well as to other technological areas. ZGS personnel pioneered many significant applications until the time the ZGS was shutdown in 1979. After the shutdown, former ZGS personnel developed magnets for new applications in high energy physics, fusion, and industrial uses. The list of superconducting magnet accomplishments of ZGS personnel is impressive.

  17. Optimization of BaZrO3 concentration as secondary phase in superconducting YBa2Cu3O7 for high current applications

    Science.gov (United States)

    Malik, Bilal A.; Malik, Manzoor A.; Asokan, K.

    2016-04-01

    We report the superconducting state properties of YBa2Cu3O7 (YBCO) on introduction of BaZrO3 (BZO) as a secondary phase. YBCO+xBZO (x= 0, 2, 4, 6, and 10 wt%) composite samples were prepared by solid state reaction method and characterized for structural, morphological and superconducting properties. X-ray diffraction confirms the increased crystallinity and images of scanning electron microscopy measurement show an increase in both grain size and grain connectivity on addition of BZO in YBCO. These effects are well pronounced in an applied magnetic field. Critical current density, JC, as well as the pinning force peaks at 4% of BZO concentration showed significant difference. A three-fold enhancement in JC and a six-fold enhancement in pinning force were observed at this optimum BZO concentration. This has been attributed to the pinning of flux lines in YBCO due to introduction of BZO as a secondary phase. These results show that this composite has potential application in high current applications.

  18. Optimization of BaZrO3 concentration as secondary phase in superconducting YBa2Cu3O7 for high current applications

    Directory of Open Access Journals (Sweden)

    Bilal A. Malik

    2016-04-01

    Full Text Available We report the superconducting state properties of YBa2Cu3O7 (YBCO on introduction of BaZrO3 (BZO as a secondary phase. YBCO+xBZO (x= 0, 2, 4, 6, and 10 wt% composite samples were prepared by solid state reaction method and characterized for structural, morphological and superconducting properties. X-ray diffraction confirms the increased crystallinity and images of scanning electron microscopy measurement show an increase in both grain size and grain connectivity on addition of BZO in YBCO. These effects are well pronounced in an applied magnetic field. Critical current density, JC, as well as the pinning force peaks at 4% of BZO concentration showed significant difference. A three-fold enhancement in JC and a six-fold enhancement in pinning force were observed at this optimum BZO concentration. This has been attributed to the pinning of flux lines in YBCO due to introduction of BZO as a secondary phase. These results show that this composite has potential application in high current applications.

  19. Design of Tunable Superconducting Metamaterials

    Science.gov (United States)

    Trepanier, Melissa; Zhang, Daimeng; Anlage, Steven

    2013-03-01

    Our goal is to create a superconducting metamaterial utilizing deep sub-wavelength meta-atoms with a quickly-tunable index of refraction. To accomplish this we will combine two different materials: an array of rf SQUIDs (with tunable effective permeability) and an array of thin wires interrupted by Josephson junctions (with tunable effective permittivity). These materials have been designed to maximize tunablility in the range easily measured via X-band, Ku-band, and K-band waveguides. Various sizes of rf SQUIDs were designed to be non-hysteretic, be sufficiently insensitive to noise, and to have resonant frequencies ranging from 6.5 - 22 GHz. The wire array was designed so that the inductance of the Josephson junctions can completely cancel the geometric and kinetic inductance of the wires, giving rise to strong tunability. We will present the design considerations and simulation results for this new class of metamaterials. This work is supported by the NSF-GOALI program through grant # ECCS-1158644, and CNAM.

  20. PREFACE: Focus on superconductivity in Fe-based systems Focus on superconductivity in Fe-based systems

    Science.gov (United States)

    Prozorov, Ruslan; Chubukov, Andrey; Meingast, Christoph; Putti, Marina

    2012-08-01

    The past four years of incredibly intense research into Fe-based superconductors have brought about many unexpected surprises. Our understanding of their behavior and physical properties is constantly evolving. Unlike any other superconductors, those containing iron span diverse groups of materials: pnictides, chalcogenides, intermetallics and oxides. Some major properties of the materials are quite similar, yet each group has its own distinct features. Significant effort has been put into identifying new superconducting compositions, modifying the existing ones with new dopants and treatments, and producing single crystals, thin films, wires and polycrystalline bulk material. A wide array of experimental techniques was applied to study Fe-based superconductors and the result is a tremendous amount of data collected over a period of less than four years. Theoretical debates are still lively, and there is an ongoing search for possible universalities and commonalities with other unconventional superconductors, like high-Tc cuprates or heavy fermion materials. The three-dimensional electronic structures of Fe-based superconductors, as well as their extreme sensitivity to disorder, present serious challenges for both theoretical analysis and the interpretation of experiments. However, some key properties emerge from multiple studies. Unconventional, multiband superconductivity originating from an electronic mechanism has found both experimental and theoretical support. There has been great progress in the understanding of various anisotropies of superconducting gap structures, including the possibility of gap nodes even if the gap symmetry is s-wave. Similar to high-Tc cuprates, the superconducting phase has a dome-like shape on T-doping or T-pressure phase diagrams. The anisotropy of the superconducting gap evolves with doping and is likely to become stronger at the dome's edge. In many Fe-based superconductors there is a range where superconductivity coexists and