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Processing and properties of Ag-clad BSCCO superconductors

Description: Long lengths of mono- and multifilament Ag-clad BSCCO (Bi-Sr-Ca-Cu-O) conductors with critical current densities of >10{sup 4} A/cm{sup 2} at 77 K were fabricated by the powder-in-tube method. {Tc} magnets were assembled by stacking pancake coils fabricated from long tapes and then tested vs applied magnetic field at various temperatures. A magnet that contained {approx}2400 m of {Tc} conductor generated a field of 3.2 T at 4.2 K. In-situ tensile and bending properties of the Ag-clad conductors… more
Date: March 1, 1996
Creator: Jammy, R.; Iyer, A.N.; Chudzik, M.; Balachandran, U. & Haldar, P.
Partner: UNT Libraries Government Documents Department
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Bosonic mechanism for high-temperature

Description: The temperature dependent photoemission data of D. S. Dessau et al. show strong modulations in the superconducting state when compared to the normal state. These are similar to but larger than those seen historically in standard tunneling experiments in lower temperature superconductors. We have analyzed the Dessau data using Nambu-Eliashberg theory assuming some (as yet unknown) boson exchange as the primary mechanism for the superconductivity. The derived {alpha}{sup 2}F's, {lambda}'s and {mu… more
Date: January 1, 1991
Creator: Mueller, F.M. (Los Alamos National Lab., NM (USA)); Arnold, G.B. (Notre Dame Univ., IN (USA). Dept. of Physics) & Swihart, J.C. (Indiana Univ., Bloomington, IN (USA). Dept. of Physics)
Partner: UNT Libraries Government Documents Department
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Weak ferromagnetism in [kappa]-(ET)[sub 2]Cu[N(CN)[sub 2]]Cl

Description: We present magnetization measurements at ambient pressure on [kappa]-(ET)[sub 2]Cu[N(CN)[sub 2]]Cl, an organic salt that is superconducting under pressure ([Tc] = 12.8 K at 0.3 kbar). An antiferromagnetic transition near 45 K and, for the first time in this class of materials, a transition near 22 K to a state displaying weak ferromagnetic hysteresis with a saturation moment of 8 x 10 [sup [minus]4][mu][sub B]/formula are observed. This low temperature state is characterized by a sequence of fi… more
Date: October 1, 1992
Creator: Welp, U.; Kwok, W. K.; Crabtree, G. W.; Carlson, K. D.; Wang, H. H.; Geiser, U. et al.
Partner: UNT Libraries Government Documents Department
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Three-terminal devices of high- Tc superconductors: A status report and future challenges

Description: A study has been conducted on the recent progress of the three-terminal devices with transistor-like characteristics fabricated from the high-{Tc} superconducting materials. This study explored the operating principles and characteristics of these devices in relation to the relevant materials and techniques. A comparison of a variety of techniques for superconducting thin film deposition will be given. This study indirates that the feasibility of fabricating hybrid devices composed of semicondu… more
Date: January 1, 1992
Creator: Kung, Pang-Jen (Los Alamos National Lab., NM (United States) Carnegie-Mellon Univ., Pittsburgh, PA (United States). Dept. of Materials Science and Engineering)
Partner: UNT Libraries Government Documents Department
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Solution of large, sparse systems of linear equations in massively parallel applications

Description: We present a general-purpose parallel iterative solver for large, sparse systems of linear equations. This solver is used in two applications, a piezoelectric crystal vibration problem and a superconductor model, that could be solved only on the largest available massively parallel machine. Results obtained on the Intel DELTA show computational rates of up to 3.25 gigaflops for these applications.
Date: January 1, 1992
Creator: Jones, M. T. & Plassmann, P. E.
Partner: UNT Libraries Government Documents Department
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Superconductor stability 90: A review

Description: This paper reviews some recent developments in the field of stability of superconductors. The main topics dealt with are hydrodynamic phenomena in cable-in-conduit superconductors, namely, multiple stability, quench pressure, thermal expulsion, and thermal hydraulic quenchback, traveling normal zones in large, composite conductors, such as those intended for SMES, and the stability of vapor-cooled leads made of high-temperature superconductors. 31 refs., 5 figs.
Date: January 1, 1990
Creator: Dresner, L.
Partner: UNT Libraries Government Documents Department
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Oak Ridge National Laboratory (ORNL) Superconducting Technology Program for electric power systems. Annual report for FY 1994

Description: 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 … more
Date: December 1, 1994
Creator: Koncinski, W. S. & Hawsey, R. A.
Partner: UNT Libraries Government Documents Department
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Conductors with small Fermi energies and small gap energies

Description: If the Fermi energy is of the order of meV`s, the usual treatment of the density of free electrons is not valid, but use can be made of an averaged density of states that depends weakly on temperature, so that the temperature variation of the conductivity can be expressed by the equation: {sigma} {congruent} CT{sup (1-s)} 1n{l_brace}[(exp({beta}E{sub f}) + 1)/2][exp({minus}{beta}(E{sub g} {minus} E{sub f})) + 1)]{r_brace} in which E{sub f} is the Fermi energy, E{sub g} is the top of the energy … more
Date: September 1, 1993
Creator: Thorn, R. J.
Partner: UNT Libraries Government Documents Department
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ORNL Superconducting Technology Program for Electric Energy Systems

Description: 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 ac… more
Date: February 1, 1993
Creator: Hawsey, R.A. (comp.)
Partner: UNT Libraries Government Documents Department
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NEDR: a computer program for calculating ac losses in a type-II superconductor with a field-dependent surface barrier

Description: A computer program ''NEDR'' which calculates low-frequency ac losses in a type-II superconductor with a field-dependent surface barrier, is presented and described. Numerous quantities associated with the losses can be calculated, including the magnetic field and flux density profiles, the surface, bulk-pinning, and bulk-annihilation contributions to the losses, the spatial dependence of the bulk losses, and the net energy loss per cycle. The program is constructed such that the critical curren… more
Date: August 1, 1976
Creator: Rouze, N. C. & Clem, J. R.
Partner: UNT Libraries Government Documents Department
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Flux Lattice Relaxation, Noise and Symmetry-Breaking in Frustrated Josephson Junction Arrays

Description: The purpose of the present report is to study: (1) Relaxation from an initially random flux state. We wish to exhibit the multiple length and time scales involved in this relaxation, and the influence of thermal fluctuations. This noisy relaxation is controlled by the dynamics of various mesoscopic defect'' structures defined with respect to the underlying ground-state flux structure. The defects, their mesoscopic collective patterns, and their dynamics control a complex macroscopic response, b… more
Date: January 1, 1993
Creator: Gronbech-Jensen, N.; Bishop, A. R. & Lomdahl, P. S.
Partner: UNT Libraries Government Documents Department
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Abstracts for Nonequilibrium Superconductivity, Phonons, and Kapitza Boundaries

Description: Compilation of abstracts for lectures that were presented at the NATO Advanced Study Institute on "Nonequilibrium Superconductivity, Phonons and Kapitza Boundaries." The topics primarily discuss work in the area of superconductivity, low-temperature phenomena, and energy-related problems in this field.
Date: May 1980
Creator: Gray, Kenneth E. & Langenberg, Donald N.
Partner: UNT Libraries Government Documents Department
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High-Temperature Superconductivity in Perspective

Description: This is the second of two OTA assessments on the subject of high-temperature superconductivity (HTS). As the title suggests, this study attempts to put HTS in perspective, both in terms of competing technologies (e.g., the more mature low-temperature superconductors), and in terms of the many technical and economic problems that must be overcome before HTS can be widely used.
Date: April 1990
Creator: United States. Congress. Office of Technology Assessment.
Partner: UNT Libraries Government Documents Department
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Commercializing high-temperature superconductivity

Description: Since the discovery of high-temperature superconductivity (HTS), research laboratories around the world have pushed the temperature limits steadily upward, opening the way to commercial applications with potentially revolutionary impacts. The scientific race is becoming a commercial race, one featuring U.S. and Japanese companies, and one that the United States could lose. Indeed, American firms may already be falling behind in commercializing the technology of superconductivity.
Date: June 1988
Creator: United States. Congress. Office of Technology Assessment.
Partner: UNT Libraries Government Documents Department
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AC Losses in the MICE Channel Magnets -- Is This a Curse or aBlessing?

Description: This report discusses the AC losses in the MICE channelmagnets during magnet charging and discharging. This report talks aboutthe three types of AC losses in the MICE magnets; the hysteretic AC lossin the superconductor, the coupling AC loss in the superconductor and theeddy current AC loss in the magnet mandrel and support structure. AClosses increase the heat load at 4 K. The added heat load increases thetemperature of the second stage of the cooler. In addition, AC losscontributes to the tem… more
Date: January 31, 2008
Creator: Green, M. A.; Wu, H.; Wang, L.; Kai, L. L.; Jia, L. X. & Yang, S. Q.
Partner: UNT Libraries Government Documents Department
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Possible Frohlich superconductivity in strong magnetic fields.

Description: A brief review of some of the arguments pointing towards the possibility of organic conductors of the form {alpha}-(BEDT-TTF)&J3g(SCN)4 (where M=K, T1 and Rb) being candidates for Frohlich superconductivity is given.
Date: January 1, 2001
Creator: Mielke, Charles H.; Harrison, Neil; Ardavan, A.; Goddard, Paul; Singleton, John; Narduzzo, A. et al.
Partner: UNT Libraries Government Documents Department
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Dynamical Layer Decoupling in a Stripe-ordered, High T_c Superconductor

Description: In the stripe-ordered state of a strongly-correlated two-dimensional electronic system, under a set of special circumstances, the superconducting condensate, like the magnetic order, can occur at a non-zero wave-vector corresponding to a spatial period double that of the charge order. In this case, the Josephson coupling between near neighbor planes, especially in a crystal with the special structure of La{sub 2-x}Ba{sub x}CuO{sub 4}, vanishes identically. We propose that this is the underlying… more
Date: April 6, 2010
Creator: Berg, E.
Partner: UNT Libraries Government Documents Department
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The hierarchy of multiple many-body interaction scales in high-temperature superconductors

Description: To date, angle-resolved photoemission spectroscopy has been successful in identifying energy scales of the many-body interactions in correlated materials, focused on binding energies of up to a few hundred meV below the Fermi energy. Here, at higher energy scale, we present improved experimental data from four families of high-T{sub c} superconductors over a wide doping range that reveal a hierarchy of many-body interaction scales focused on: the low energy anomaly ('kink') of 0.03-0.09eV, a hi… more
Date: May 3, 2010
Creator: Meevasana, W.
Partner: UNT Libraries Government Documents Department
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Development of Substrate for RABiTS-based HTS Conductors

Description: During its fifteen years of life, this CRADA has evolved in both scope and purpose. Early efforts to develop high performance bismuth-based powder-in-tube first generation high temperature superconductors (HTS) have shifted toward efforts to understand and develop technologies required to fabricate second generation HTS coated conductors. Since the two original longstanding principal investigators from UT-Battelle and Oxford Superconducting Technology (OST) are not presently employed by their r… more
Date: June 5, 2009
Partner: UNT Libraries Government Documents Department
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On stability of odd-frequency superconducting state

Description: Odd-frequency pairing mechanism has been investigated for several decades. Nevertheless the properties of such superconducting phase as well as its thermodynamic stability have remained unclear. In particular it has been argued by numerous authors that the odd-frequency state is thermodynamically unstable, has an unphysical Meissner effect (at least within the mean-field approximation), and therefore can not exist as a homogeneous phase in equilibrium physical systems. We argue that such a conc… more
Date: January 1, 2008
Creator: Lenov, Bmitry; Martin, Ivar & Mozyrsky, Dima
Partner: UNT Libraries Government Documents Department
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Practical superconductor development for electrical power applications - quarterly report for the period ending Dec. 31, 2003.

Description: This is a multiyear experimental research program that focuses on improving relevant material properties of high-critical temperature (Tc) superconductors and developing fabrication methods that can be transferred to industry for production of commercial conductors. The development of teaming relationships through agreements with industrial partners is a key element of the Argonne National Laboratory (ANL) program.
Date: March 2, 2004
Creator: Dorris, S. E.
Partner: UNT Libraries Government Documents Department
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Unusual interlayer transport in quasi-two-dimensional organic metals.

Description: The interlayer transport properties of the organic superconductor {beta}{double_prime}-(ET){sub 2}SF{sub 5}CH{sub 2}CF{sub 2}SO{sub 3} are presented. The resistivity perpendicular to the highly conducting ET layers is about 100 times larger than compared to other quasi-two-dimensional ET salts. For a magnetic field parallel to the layers no peak could be resolved in the angle-dependent interlayer resistance which proved the coherent nature of transport in other ET salts. This and the absence of… more
Date: September 23, 2002
Creator: Wosnitza, J.; Hagel, J.; Schlueter, J. A.; Geiser, U.; Mohtasham, U.; Winter, R. W. et al.
Partner: UNT Libraries Government Documents Department
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Melt-texturing of carbon containing YBa{sub 2}Cu{sub 3}O{sub 7-x}: Influence of processing parameters on microstructure and flux-pinning behavior

Description: A detailed study of the flux-pinning behavior of sintered and melt-textured YBa{sub 2}Cu{sub 3}O{sub 7-x} has been carried out by means of microstructural investigations (optical microscopy, SEM, TEM, EDS, DTA, and XRD) and magnetization measurements. It was found that both microstructure and magnetization behavior strongly depend on the starting material, the production method, and the maximum processing temperature. In our experiments, the critical current density, J{sub c}, increased with in… more
Date: January 1, 1994
Creator: Todt, V.R.; Sengupta, S.; Chen, Y.L.; Shi, Donglu; Poeppel, R.; McGinn, P.J. et al.
Partner: UNT Libraries Government Documents Department
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