Superconducting magnets and superconductivity : research, technology and applications / Henry Tovar and Jonathon Fortier, editors.

Format:

Book

Contributor:

Tovar, Henry.

Fortier, Jonathon.

Language:

English

Subjects (All):

Superconducting magnet.

Superconductivity.

Physical Description:

1 online resource (442 p.)

Edition:

1st ed.

Place of Publication:

Hauppauge, N.Y. : Nova Science Publishers, 2009.

Language Note:

English

Summary:

This book presents current areas of research in the field of superconductors and superconducting magnets. The ways in which these magnets produce stronger magnetic fields than ordinary iron-core electromagnets is explored. A review of the electronic structure of transition metal oxides and salts is also included in this book, specifically what concerns electron transfer, electron correlation, electron-nuclear coupling, and inter-metal interaction in cuprates. Combining a number of well-known theories of conventional superconductors, a general vortex theory for inhomogeneous superconductors is proposed. Ways to fabricate superconducting magnets in a faster, cheaper and more practical way is also presented.

Contents:

Intro

SUPERCONDUCTING MAGNETS ANDSUPERCONDUCTIVITY: RESEARCH,TECHNOLOGY AND APPLICATIONS

CONTENTS

PREFACE

RESEARCH AND REVIEW STUDIES

CORRELATION EFFECTS AND SUPERCONDUCTIVITYIN CUPRATES: A CRITICAL ACCOUNT

Abstract

1. Introduction

2. Electronic Correlation in Molecules

3. Electron Structure of Embedded Transition Metal Ion

4. Metal - Metal Interaction and the MV-2 Model

5. Mott Problem Involves Three Oxidation States (MV-3)

6. Variational Calculations of Electron Structure

7. Pair Currents in the Ground State

8. Vibronic Wave Functions. Energy Gap

9. Phonon Softening

10. ARPES

11. Discussion and Conclusion

References

IMPROVED FLUX PINNING PROPERTIES FOR RE123SUPERCONDUCTORS BY CHEMICAL METHODS

2. Dilute Impurity Doping Effects

2.1. Dilute Lu-Doping Effect for Y123 Melt-solidified Bulk

2.2. Effect of Dilute Impurity Doping to CuO-Chain

2.3. Dilute Impurity Doping Effects for Dy123 Melt-Solidified Bulks

2.4. Changes in Pinning Effect by Dilute Chemical Doping to DifferentCation Sites

3. New Effective Pinning Site: BaTbO3 Precipitates

3.1. BaTbO3 Addition

3.2. Tb4O7 Addition

4. Conclusion

Acknowledgements

MECHANICAL CHARACTERIZATIONAT NANOMETRIC SCALE OF CERAMICSUPERCONDUCTOR COMPOSITES

1.1. High-Temperature Superconductors (HTSC)

1.1.1. Solidification and Microstructure of YBCO Bulk Materials

a. Top-Seeded Melt-Growth (TSMG) Technique

b. Bridgman Technique

1.1.2. Oxygenation Process

a) Mechanical stress

b) Propagation of cracks during oxygenation

1.1.3. Applications

1.2. Indentation Testing Technique

1.2.1. Testing Equipment (Instrumentation).

1.2.2. Nanoindenter's Tips

1.2.3. Good Experimental Practice

a) Choosing an appropriate indenter

b) Environmental control

c) Surface preparation

d) Testing procedure

e) Detecting the surface

1.2.4. Experimental Techniques

a. Hardness and elastic modulus measurements

b. Spherical indentation (Determination of the stress-strain curves)

c. Fracture toughness measurement

1.2.5. The Effective Indenter Shape

1.2.6. Errors due to Pile-up and Sinking-in

1.2.7. Indentation Size Effect, ISE

a. Meyer's law

b. Hays-Kendall approach

c. Elastic recovery model or Elastic/Plastic deformation model

d. Proportional specimen resistance model or PSR model

e, The modified PSR model

2. Mechanical Properties

2.1. State of the Art of Mechanical Properties of YBCO Samples

2.2. Mechanical Properties of YBCO Samples Textured by Bridgman andTSMG Technique by Nanoindentation

2.2.1. Plastic Deformation

Experimental Conditions

Experimental Curves

Characterization Imprints

Hardness

Young's Modulus

c. Indentation Size Effect

d. Pile-up and Sink-in Problems

Fracture Toughness

2.2.2. Elastic Deformation

Determination of the Elasto-plastic Transition

Stress-Strain Curves

2.2.3. Kinetic Study by Nanoindentation Technique of TSMG Samplesalong the c-axis at 450ºC

Oxygenation Defects and Macro-microckrackingin Melt-textured YBCO Bulks

Determination of the Kinetics of Oxygenation by Nanoindentation

Prediction of the Oxygenation Time in YBCO Bulk Materials

UNDERSTANDING THE ROLES OF HEAVY IONAND GAMMA-IRRADIATIONS ON THE MAGNETICAND TRANSPORT PROPERTIESOF SUPERCONDUCTORS

1.1. Normal State Resistivity of MgB2 Bulk Sample

1.2. Enhancing the Critical Current Density in HTSCs.

1.3. Effects of Heavy Ion - and γ -Irradiations on Superconductors

1.4. Aims of the Article

2. Experimental Procedures

2.1.1. The MgB2 Polycrystalline Sample

2.1.2. The YBa2Cu3O7-δ Crystalline Sample

2.1.3. The YBa2Cu3O7-δ Polycrystalline Sample

2.1.4. The Mn Doped YBa2Cu3O7-δ Polycrystalline Samples

2.1.5. The B Doped YBa2Cu3O7-δ Polycrystalline Samples

2.1.6. The Bi1.6Pb0.4Sr2Ca2Cu3O10 Polycrystalline Sample

2.1.7. The Tl2Ba2Ca2Cu3O10 Tape

2.2. Gamma Irradiation Source

2.3. Magnetic Measurements

2.4. Voltage-Current Measurements

3. Results and Discussion

3.1. Normal State Resistivity of the MgB2 Sample

3.2. Critical Current Density in the MgB2 Sample

3.3. Magnetization of the Pb-Ion Irradiated YBa2Cu3O7-δ Crystal

3.4. Critical Current Density in the Mn-Doped YBa2Cu3O7-δ Sample

3.5. Magnetization of the B-Doped YBa2Cu3O7-δ Sample

3.6. Critical Current Density in the γ-irradiated YBa2Cu3O7-δ Sample

3.7. Critical Current Density in the γ-irradiated Tl2Ba2Ca2Cu3O10 Tape

3.8. Critical Current Density in the γ-irradiated Bi1.6Pb0.4Sr2Ca2Cu3O10Sample

3.9. Mechanisms of γ-Rays in the Grain Boundary Regions

Acknowledgment

ON THE MELT PROCESSING OF BI-2223 HIGH-TCSUPERCONDUCTOR CHALLENGESAND PERSPECTIVES

2. The Bi-2223 Phase and the BSCCO System

3. Melt Processing of Bi-2223

3.1. The Glass-Ceramic Route

3.2. Melt-Processing by Peritectic Decomposition

3.2.1. Peritectic Melting

3.2.2. Bi-2223 Crystallization from the Peritectic Melt

4. Summary

VORTEX THEORY OF INHOMOGENEOUSSUPERCONDUCTORS

2. Vortex Theory for Inhomogeneous Superconductors

2.1. Solution of Linearized Ginzburg-Landau Equation

2.2. Vortex Solution.

2.3. Gibbs Free Energy of Vortex Solution

3. Vortex State in a Rectangular Prism

3.1. Eigenenergy Spectrum

3.2. Vortex Solution and Varying Symmetry

3.3. Thermodynamical Analysis

3.4. Effect of Artificial Arrayed Pining Centers

4. Vortex State in a Superconducting Film

4.1. Eigen Problem

4.2. Vortex State in a Film

4.3. Thermodynamical Properties of the Vortex State in a Film

5. Vortex State in a Superlattice

5.1. Eigen Problem in a Superlattice

5.2. Vortex States in a Superlattice

5.3. Vortex Lattice in a Superlattice

6. Conclusion

Acknowledgement

Appendix

FABRICATION OF PYROCHLORE-BASED BUFFERLAYERS FOR COATED CONDUCTORS VIA CHEMICALSOLUTION DEPOSITION

2. Effects of Annealing Temperature and Seed Layers on the LZOBuffer Layers

3. Effects of Film Thickness and Solution Concentration on theLZO Buffer Layers

4. The Property of YBCO/CeO2/LZO/NiW Substrates

5. YTO/LZO Composite Pyrochlore-Based Buffer Layers Derivedby CSD Method

RADIATION SHIELDING SCHEMES AND ADVANCEDFABRICATION TECHNIQUESFOR SUPERCONDUCTING MAGNETS

I. Introduction

II. Magnet System Constituents

II.1. Superconducting Materials

II.2. Structural Materials

II.3. Insulating Materials

II.4. Stabilizing Materials

III. Radiation Limits

IV. Radiation Shielding Schemes

V. Advanced Fabrication of Superconducting Magnet Systems

V.1. Conventional Coil Fabrication Approaches

V.2. Innovative Structural Fabrication Approaches

V.3. Summary

VI. Conclusion

THERMAL STABILITY CHARACTERISTICS OF HIGHTEMPERATURE SUPERCONDUCTING COMPOSITES

1. Introduction.

2. Sub- and Overcritical Static Stable Regimes ofSuperconducting Composites with Different Voltage-CurrentCharacterictics

2.1. Static Zero-Dimensional Thermo-electric Model

2.2. Static Thermal Runaway Conditions and the Current Sharing Effect onthe Stationary Fully Penetrated Current Regimes

2.3. Qualitative Analysis of the Thermal Runaway Conditions

2.4. Quantitative Analysis of the Current Instability Conditions at LowOperating Temperature (T0=4.2 K)

2.5. Conclusion

3. Multi-Stable Static Modes of High TemperatureSuperconducting Composites with Nonlinear Jc(T)-Dependence at Different Operating Regimes

3.1. Static Differential Resistivity of a Superconducting Composite withArbitrary Temperature Dependences of Its Properties

3.2. Nontrivial Steady Electric and Thermal Regimes of Conduction-CooledAg/Bi2212 Composite

3.3. Thermal Runaway Conditions of a Superconducting Composite withMulti-stable Current Modes

3.4. Conclusion

4. Thermal Runaway Phenomenon in SuperconductingComposites Cooled by Liquid Coolant

4.1. Thermo-electric and Cooling Models

4.2. Quench Characteristics of Ag/Bi2212 Composite under Nucleate andFilm Boiling Regimes of Coolant

4.3. Conclusion

5. Quench Conditions under Transient Current Modes

5.1. Governing Equations

5.2. Stable and Unstable Operating Transient Modes of High TemperatureSuperconducting Composite at Helium Bath Temperature

5.3. Size Effect on the Thermo-Electric Mode Formation of High-TcSuperconducting Composite

5.4. Formation Peculiarities of the Transient Regimes at IntermediateCoolant Temperatures

5.5. Stabilization Role of the Additional Branch of Voltage-CurrentCharacteristic before Thermal Runaway with Respect to ExternalThermal Disturbances

5.6. Conclusion

6. Resume

SHORT COMMUNICATION.

THERMO-MECHANICAL PUMPS FOR A LARGESUPERCONDUCTING MAGNET IN SPACE OPERATEDBY USE OF SUPERFLUID HELIUM.

Notes:

Description based upon print version of record.

Includes bibliographical references and index.

Description based on print version record.

ISBN:

1-61728-587-0

OCLC:

665793787