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Superconducting materials for large scale applications

Description: 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.
Date: May 6, 2004
Creator: Scanlan, Ronald M.; Malozemoff, Alexis P. & Larbalestier, David C.
Partner: UNT Libraries Government Documents Department

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 high energy anomaly of 0.3-0.5eV, and an anomalous enhancement of the width of the LDA-based CuO{sub 2} band extending to energies of {approx} 2 eV. Besides their universal behavior over the families, we find that all of these three dispersion anomalies also show clear doping dependence over the doping range presented.
Date: December 21, 2006
Creator: Hussain, Zahid; Meevasana, W.; Zhou, X.J.; Sahrakorpi, S.; Lee, W.S.; Yang, W.L. et al.
Partner: UNT Libraries Government Documents Department

Proceedings of Cryocooler Conference: 1984

Description: Abstract: This document contains the proceedings of the Third Cryocooler Conference, held at the National Bureau of Standards, Boulder, CO, on Sept. 17-18, 1984. About 140 people from 10 countries attended the conference and represented industry, government, and academia. A total of 26 papers were presented orally at the conference and all appear in written form in this document. The emphasis in this conference was on small cryocoolers in the temperature range of 4 - 80 K. Mechanical and non-mechanical types were discussed in the various papers. Applications of these small cryocoolers include the cooling of infrared detectors, cryopumps, small superconducting devices and magnets, and electronic devices.
Date: May 1985
Creator: Radebaugh, Ray; Louie, Beverly & McCarthy, Sandy E.
Partner: UNT Libraries Government Documents Department

Fluctuation phenomena in layered superconductors

Description: Gaussian fluctuations in layered superconductors have been the subject of study for many years. Although the FD was studied in detail long ago, the FC (fluctuation conductivity) was studied only recently, since the MT and DOS diagrams were previously neglected. Recent comparisons with experiment on YBCO have shown that the DOS diagrams are important and can lead to qualitatively different behaviors for the FC parallel and perpendicular to the layers. In both cases, Gaussian fluctuations fit the data above {Tc} very well, even for YBCO. To date, nearly all calculations of fluctuation quantities were for B{parallel}{cflx c}. Nevertheless, it should be possible to treat an arbitrary B, but the evaluation of the required matrix elements for the fluctuation quantities will be more complicated.
Date: October 1, 1996
Creator: Klemm, R.A.
Partner: UNT Libraries Government Documents Department

Layered nickel based superconductors

Description: We review the properties of Ni-based superconductors which contain Ni{sub 2}X{sub 2} (X=As, P, Bi, Si, Ge, B) planes, a common structural element to the recently discovered FeAs superconductors. We also compare the properties ofthe Ni-and Fe-based systems from a perspective ofelectronic structure as well as structure-property relations.
Date: January 1, 2009
Creator: Ronning, Filip; Bauer, Eric D; Park, Tuson; Kurita, Nobuyuki; Klimczuk, T; Movshovich, R et al.
Partner: UNT Libraries Government Documents Department

Design of a Tunable High-Q Superconducting Notch Filter

Description: The design of a tunable high-Q superconducting notch filter is presented. The filter is designed to be manufactured from high Tc superconductors (Nb3S, Nb3Ge) made by high-rate magnetron sputtering on sapphire substrates. The geometry of the various elements, holder materials for the cryostat, studies relating to the preparation of suitable high Tc materials, and the photo-etching procedures for the filter elements are discussed.
Date: October 1978
Creator: Falco, Charles M.; Kampwirth, R. T.; Pang, C. S. & Schuller, Ivan K.
Partner: UNT Libraries Government Documents Department

Flux Flow, Pinning, and Resistive Behavior in Superconducting Networks

Description: Numerical simulators are used to study the behavior of interacting quantized vortices and vortex lines in superconducting networks, films, and three dimensional bulk samples. An emphasis is on the explanation of the phenomenological behavior of the ''high-Tc'' copper-oxide superconductors and related model systems.
Date: May 3, 2005
Creator: Teitel, Stephen
Partner: UNT Libraries Government Documents Department

Final Report

Description: This grant resulted in three distinct scientific advances, the most important being the discovery of a inhomogeneous superconducting state first predicted over 40 years ago. Two graduate students received PhDs as a result of this grant, and a major US high magnetic field facility was rebuilt.
Date: June 14, 2013
Creator: Agosta, Charles C.
Partner: UNT Libraries Government Documents Department

Cable Measuring Engine Operation Procedures

Description: The Cable Measuring Engine (CME) is a tool which measures and records the cable dimensions in a nondestructive fashion. It is used in-line with the superconductor cable as it is being made. The CME is intended to be used as a standard method of measuring cable by the various manufacturers involved in the cable process.
Date: July 11, 1997
Creator: Authors, Various
Partner: UNT Libraries Government Documents Department

Evaluation of methods for application of epitaxial layers of superconductor and buffer layers

Description: The recent achievements in a number of laboratories of critical currents in excess of 1.0x10{sup 6} amp/cm{sup 2} at 77K in YBCO deposited over suitably textured buffer/substrate composites have stimulated interest in the potential applications of coated conductors at high temperatures and high magnetic fields. As of today, two different approaches for obtaining the textured substrates have been identified. These are: Los Alamos National Laboratory`s (LANL) ion-beam assisted deposition called IBAD, to obtain a highly textured yttria-stabilized zirconia (YSZ) buffer on nickel alloy strips, and Oak Ridge National Laboratory`s (ORNL) rolling assisted, bi-axial texturized substrate option called RABiTS. Similarly, based on the published literature, the available options to form High Temperature Superconductor (HTS) films on metallic, semi-metallic or ceramic substrates can be divided into: physical methods, and non-physical or chemical methods. Under these two major groups, the schemes being proposed consist of: - Sputtering - Electron-Beam Evaporation - Flash Evaporation - Molecular Beam Epitaxy - Laser Ablation - Electrophoresis - Chemical Vapor Deposition (Including Metal-Organic Chemical Vapor Deposition) - Sol-Gel - Metal-Organic Decomposition - Electrodeposition, and - Aerosol/Spray Pyrolysis. In general, a spool- to-spool or reel-to-reel type of continuous manufacturing scheme developed out of any of the above techniques, would consist of: - Preparation of Substrate Material - Preparation and Application of the Buffer Layer(s) - Preparation and Application of the HTS Material and Required Post-Annealing, and - Preparation and Application of the External Protective Layer. These operations would be affected by various process parameters which can be classified into: Chemistry and Material Related Parameters; and Engineering and Environmental Based Parameters. Thus, one can see that for successful development of the coated conductors manufacturing process, an extensive review of the available options was necessary. Under the U.S. Department of Energy (DOE`s) sponsorship, the University of Tennessee Space Institute (UTSI), was ...
Date: June 1, 1997
Partner: UNT Libraries Government Documents Department

Vortices wiggled and dragged

Description: When a sufficiently strong magnetic field is applied to a superconductor, some of the field can pierce it through the generation of magnetic vortices, each of which contains a quantized amount of magnetic flux. Although the superconducting state of the material outside each vortex is maintained (and destroyed within each vortex), the interaction of vortices with a current passing through the material can cause them to move, dissipating energy and thereby generating a source of electrical resistance. The ability to manipulate an individual superconducting vortex represents a powerful tool for studying the dynamics of vortices and the superconductors that support them. It could also lead to the development of a new class of fluxon-based electronics.
Date: January 1, 2008
Creator: Reichhardt, Charles
Partner: UNT Libraries Government Documents Department

Nonequilibrium THz Conductivity of Bi2Sr2CaCu2O8+d

Description: Using high sensitivity visible-pump/THz-probe spectroscopywe investigate the dynamics of the complex optical conductivity inoptimally-doped Bi2Sr2CaCu2O8+d films directly after photoexcitation. Thephotoinduced change in the imaginary part, indicative of a reduction inthe superconducting condensate density, saturates at higherlaser-fluences and shows a complete destruction of thecondensate.
Date: May 27, 2003
Creator: Carnahan, M. A.; Kaindl, R. A.; Orenstein, J.; Chemla, D. S.; Oh, S. & Eckstein, J. N.
Partner: UNT Libraries Government Documents Department

Optical Properties of {beta}''-(ET){sub 2}SF{sub 5}CH{sub 2}CF{sub 2}SO{sub 3} : a novel superconductor with large discrete counterions.''

Description: The optical spectra of the organic superconductor {beta}{double_prime}-(ET){sub 2}SF{sub 5}CH{sub 2}CF{sub 2}SO{sub 3} are measured over a wide spectral range (30-35000 cm{sup {minus}1}) as a function of temperature and polarization. The optical anisotropy is quite large compared with other ET-based organic superconductors, and the spectra are far from Drude-like over the full temperature range. A broad electronic band centered near 1000 cm{sup {minus}1} is observed at low temperature along the a axis, prior to the superconducting transition. The changes of vibrational features near 120 K are attributed to a weak reorientation of the counterion, which may affect hydrogen bonding in the material.
Date: August 6, 1998
Creator: Dong, J.
Partner: UNT Libraries Government Documents Department

Magnetic imaging of interlayer Josephson vortices.

Description: The authors have magnetically imaged interlayer Josephson vortices emerging parallel to the planes of single crystals of the organic superconductor {kappa}-(BEDT-TTF){sub 2} Cu(NCS){sub 2}, and the single layer cuprate high-T{sub c} superconductors Tl{sub 2}Ba{sub 2}CuO{sub 6+{delta}} (Tl-2201) and (Hg,Cu)Ba{sub 2}CuO{sub 6+{delta}} (Hg-1201), using a scanning Superconducting Quantum Interference Device (SQUID) microscope. These images provide a direct measurement of the interlayer penetration depth, which is approximately 63 {micro}m for {kappa}-(BEDT-TTF){sub 2} Cu(NCS){sub 2}, 18 {micro}m for Tl-2201 and 8 {micro}m for Hg-1201. The lengths for the cuprates are about a factor of 10 larger than originally predicted by the interlayer tunneling model for the mechanism of superconductivity in layered compounds, indicating that this mechanism alone cannot account for the high critical temperatures in these materials.
Date: January 15, 1999
Creator: Kirtley, J. A.
Partner: UNT Libraries Government Documents Department

Practical Superconductor Development for Electrical Power Applications Semiannual Report: October 1989-June 1990

Description: Progress report for the superconductor program at Argonne National Laboratory discussing the group's activities and research. This report describes technical progress of research and development efforts aimed at producing superconducting components based on the Y-Ba-Cu, Bi-Sr-Ca-Cu, and Tl-Ba-Ca-Cu oxide systems.
Date: June 1990
Creator: Argonne National Laboratory. Materials and Components Technology Division.
Partner: UNT Libraries Government Documents Department

Practical Superconductor Development for Electrical Power Applications, Annual Report: 1990

Description: Annual report for the superconductor program at Argonne National Laboratory discussing the group's activities and research. This report describes technical progress of research and development efforts aimed at producing superconducting components based on the Y-Ba--Cu, Bi-Sr-Ca-Cu, Bi-Pb-Sr-Ca-Cu, and TI-Ba-Ca-Cu oxide systems including: synthesis and heat treatment of high-Ta superconductors, formation of monolithic and composite wires and tapes, superconductor/metal connectors, characterization of structures and superconducting and mechanical properties, and fabrication and properties of thin films.
Date: October 1990
Creator: Argonne National Laboratory. Materials and Components Technology Division.
Partner: UNT Libraries Government Documents Department

Practical Superconductor Development for Electrical Power Applications, Annual Report: 1991

Description: Annual report for the superconductor program at Argonne National Laboratory discussing the group's activities and research. This report describes technical progress of research and development efforts aimed at producing superconducting components based on the Y-Ba-Cu, BI-Sr-Ca-Cu, Bi-Pb-Sr-Ca-Cu, and TI-Ba-Ca-Cu oxide systems including: synthesis and heat treatment of high-Te superconductors, formation of monolithic and composite wires and tapes, superconductor/metal connectors, characterization of structures and superconducting and mechanical properties, and fabrication and properties of thin films.
Date: October 1991
Creator: Argonne National Laboratory. Materials and Components Technology Division.
Partner: UNT Libraries Government Documents Department

Practical Superconductor Development for Electrical Power Applications, Annual Report: 1988

Description: Annual report for the superconductor program at Argonne National Laboratory discussing the group's activities and research. This report documents research efforts aimed at producing superconducting components based on oxide systems.
Date: February 1989
Creator: Argonne National Laboratory. Materials and Components Technology Division.
Partner: UNT Libraries Government Documents Department