Filamentary A15 Superconductors

Filamentary A15 Superconductors PDF

Author: Masaki Suenaga

Publisher: Springer Science & Business Media

Published: 2013-03-08

Total Pages: 372

ISBN-13: 1468438875

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Compound superconductors with the Al5 structure carry the promise of the second generation in practical superconductivity. They will provide higher operating magnetic fields at higher tem peratures than the preceding alloy superconductors. To fulfill this promise, their brittle nature must be accommodated in a fila mentary structure. Achieving this has been no simple task and imaginative research and clever production techniques have led to many usable conductor configurations. In addition, several new and exciting possibilities are being proposed; for example, in situ processing promises easier production with improved strain toler ance. It is timely, therefore, to take measure of what we have achieved and to assess our understanding so that we may choose, with some confidence, paths for future research and potential ap plications. To meet these needs, the International Cryogenic Materials Conference Board has sponsored this special topic conference on Filamentary Al5 Superconductors bringing together superconductiv ity researchers, superconducting wire producers, and high field magnet users to discuss current research problems. That the in formation exchange was intensive and successful is evidenced by the excellent papers in this volume. In order to capture some of the synergistic wisdom generated in discussions at the conference several people were asked to assemble and interpret the comments and concerns of the fusion, high energy physics, solid state phys ics, and metallurgy groups.

Filamentary A15 Superconductors

Filamentary A15 Superconductors PDF

Author: Masaki Suenaga

Publisher: Springer

Published: 1980-12-01

Total Pages: 0

ISBN-13: 9780306406225

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Compound superconductors with the Al5 structure carry the promise of the second generation in practical superconductivity. They will provide higher operating magnetic fields at higher tem peratures than the preceding alloy superconductors. To fulfill this promise, their brittle nature must be accommodated in a fila mentary structure. Achieving this has been no simple task and imaginative research and clever production techniques have led to many usable conductor configurations. In addition, several new and exciting possibilities are being proposed; for example, in situ processing promises easier production with improved strain toler ance. It is timely, therefore, to take measure of what we have achieved and to assess our understanding so that we may choose, with some confidence, paths for future research and potential ap plications. To meet these needs, the International Cryogenic Materials Conference Board has sponsored this special topic conference on Filamentary Al5 Superconductors bringing together superconductiv ity researchers, superconducting wire producers, and high field magnet users to discuss current research problems. That the in formation exchange was intensive and successful is evidenced by the excellent papers in this volume. In order to capture some of the synergistic wisdom generated in discussions at the conference several people were asked to assemble and interpret the comments and concerns of the fusion, high energy physics, solid state phys ics, and metallurgy groups.

Metallurgy of Continuous Filamentary A15 Superconductors

Metallurgy of Continuous Filamentary A15 Superconductors PDF

Author:

Publisher:

Published: 1980

Total Pages:

ISBN-13:

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The early history of the bronze process is recapitulated and modifications to the process which have since followed are described. The metallurgical principles, which are involved in the process, are described including the kinetics of the compound growth, the effects of additives on the growth, etc. The superconducting properties of these compounds are also discussed. The influence of metallurgical variables on the superconducting properties is discussed in detail. In discussing the superconducting current densities in these compounds, limits in applicability of existing magnetic-flux-pinning models are also treated as well as methods for determining critical magnetic fields.

A15 Multifilamentary Superconductors by the Infiltration Process

A15 Multifilamentary Superconductors by the Infiltration Process PDF

Author:

Publisher:

Published: 1980

Total Pages:

ISBN-13:

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The inherent brittleness of the A15 compounds, and the requirement for a filamentary morphology, led to a heavy reliance on a powder approach for the preparation of superconducting tapes and wires. The quench-age technique, a non-powder process, was employed for the niobium-aluminum system, following the special features of the equilibrium phase diagram. The powder approach proved particularly effective for binaries, such as Nb-Sn, and for the ternaries Nb(Al, Ge) and Nb(Al, Si). Two variations of the powder process were assessed. One involved the use of precompounded powder of the desired stoichiometry but required simultaneous application of heat and pressure. The second variation was the infiltration process. This process involves the preparation of a ductile niobium matrix containing a controlled network of interconnected pores which are subsequently infiltrated with liquid metals (Sn) or low melting-point eutectics (e.g., Al-Ge, Al-Si). The composite is then subjected to a thermomechanical treatment to form a multiply connected array of A15 filaments in a niobium matrix. Multifilamentary conductors, based on Nb3Sn, Nb3Al, Nb3 (Al, Ge) and Nb3 (Al, Si), were readily obtained. Nb3Sn conductors made by the infiltration process exhibit a critical temperature (Tc) of 18.1 K and a critical current carrying capacity (I/sub c/) of 8 x 104 amp.cm−2 at 12 Tesla.

Handbook of Superconducting Materials

Handbook of Superconducting Materials PDF

Author: David A. Cardwell

Publisher: CRC Press

Published: 2003

Total Pages: 1120

ISBN-13: 9780750304320

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With the advent of High Temperature Superconductivity and the increasing reliability of fabrication techniques, superconductor technology has moved firmly into the mainstream of academic and industrial research. There is currently no single source of practical information giving guidance on which technique to use for any particular category of superconductor. An increasing number of materials scientists and electrical engineers require easy access to practical information, sensible advice and guidance on 'best-practice' and reliable, proven fabrication and characterisation techniques.The Handbook will be the definitive collection of material describing techniques for the fabrication and analysis of superconducting materials. In addition to the descriptions of techniques, authoritative discussions written by leading researchers will give guidance on the most appropriate technique for a particular situation.Characterisation and measurement techniques will form an important part of the Handbook, providing researchers with a standard reference for experimental techniques. The tutorial style description of these techniques makes the Handbook particularly suitable for use by graduate students.The Handbook will be supported by a comprehensive web site which will be updated with new data as it emerges.The Handbook has six main sections: -- Fundamentals of Superconductivity - characteristic properties, elementary theory, critical current of type II superconductors-- Processing - bulk materials, wires and tapes, thick and think films, contact techniques-- Characterisation Techniques - structure/microstructure, measurement and interpretation of electromagnetic properties,measurement of physics properties-- Materials - characteristic properties of low and high Tc materials-- Applications - high current applications, trapped flux devices, high frequency devices, josephson junction devic

Studies of the Strain-dependent Properties of A15 Filamentary Conductors at Brookhaven National Laboratory

Studies of the Strain-dependent Properties of A15 Filamentary Conductors at Brookhaven National Laboratory PDF

Author:

Publisher:

Published: 1980

Total Pages:

ISBN-13:

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Work at BNL pertaining to the strain response of filamentary bronze-processed superconductors is reviewed. This work includes the intrinsic strain dependence of the critical properties of A15 structure compounds, the nature of the initial internal strain state of composite conductors, and the interplay between these residual strains and applied strains which governs the response of the conductor to external strain. Some factors which can enhance the strain tolerances of filamentary conductors are briefly discussed. (GHT).

Functional Materials

Functional Materials PDF

Author: S. Banerjee

Publisher: Elsevier

Published: 2011-12-09

Total Pages: 731

ISBN-13: 0123851432

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Functional materials have assumed a very prominent position in several high-tech areas. Such materials are not being classified on the basis of their origin, nature of bonding or processing techniques but are classified on the basis of the functions they can perform. This is a significant departure from the earlier schemes in which materials were described as metals, alloys, ceramics, polymers, glass materials etc. Several new processing techniques have also evolved in the recent past. Because of the diversity of materials and their functions it has become extremely difficult to obtain information from single source. Functional Materials: Preparation, Processing and Applications provides a comprehensive review of the latest developments. Serves as a ready reference for Chemistry, Physics and Materials Science researchers by covering a wide range of functional materials in one book Aids in the design of new materials by emphasizing structure or microstructure – property correlation Covers the processing of functional materials in detail, which helps in conceptualizing the applications of them

Advances in Cryogenic Engineering Materials

Advances in Cryogenic Engineering Materials PDF

Author: R.W. Fast

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 904

ISBN-13: 1461335426

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The Fourth International Cryogenic Materials Conference (ICMC) was held in San Diego, California in conjunction with the Cryogenic Engineer ing Conference (CEC) on August 10-l4, 1981. The synergism produced by conducting the two conferences together remains very strong. In the ap pl1cation of cryogenic technology, materials continue to be a demanding challenge, and sometimes, an obstacle. The association of materials and cryogenic engineers increases their awareness of recent research in each other's fields and influences the course of future research. Many contributed to the success of the 1981 conference. J. W. Morris of the University of California--Berkeley was ICMC Conference Chairman. E. N. C. Dalder of Lawrence Livermore Laboratories was ICMC Structural Program Chairman; D. C. Larbalestier of the University of Wisconsin- Madison, and D. K. Finnemore of Iowa State University were Superconducting Materials Program Chairmen. Local arrangments were expertly coordinated by R. E. Tatro of General Dynamics--San Diego. The CEC Board, especia11y their conference chairman, T. M. Flynn, of the National Bureau of Stan dards, Boulder, contributed very substantia1ly to conference planning and implementation. All of their efforts provided the foundation of the largest CEC/ICMC ever. We thank the Office of Naval Research and the Office of Fusion Energy and Basic Energy Sciences of the Department of Energy for providing needed financial support for the conference. Fina11y, we especially thank M. Stieg, who prepared the papers for the new procedures and format used in this volume.