Superconductivity: Basics and Applications to Magnets

✍ Scribed by R. G. Sharma

• Publisher: Springer Nature
• Year: 2021
• Tongue: English
• Leaves: 649
• Series: Springer Series in Materials Science 214
• Edition: 2
• Category: Library

✦ Table of Contents

Preface to Second Edition
Acknowledgements
Contents
About the Author
1 Introduction
1.1 Why Low Temperature Is so Exciting?
1.2 How to Conduct Experiment at Low Temperatures?
1.3 Gas Liquefaction
1.3.1 Isenthalpic Process
1.3.2 Isentropic Process
1.3.3 The Linde–Hampson Process
1.3.4 The Claude Process
1.3.5 Liquefaction of Helium (1908)
1.3.6 Collins Liquefaction Cycle
1.4 Discovery of Superconductivity—A Fall-Out of Helium Liquefaction
References
2 The Phenomenon of Superconductivity and Type II Superconductors
2.1 Electrical Conduction in Metals
2.2 The Phenomenon of Superconductivity
2.3 The Critical Magnetic Field
2.4 The Meissner Effect (Field Expulsion)
2.4.1 Perfect Diamagnetism
2.4.2 The Penetration Depth
2.4.3 Magnetization in Superconductors
2.4.4 The Intermediate State
2.5 Two-Fluid Model
2.6 Thermodynamics of Superconductors
2.6.1 The Gibbs Free Energy
2.6.2 Specific Heat
2.6.3 Phase Transition
2.7 Thermal Conductivity
2.8 Thermoelectric Power
2.9 The Energy Gap
2.10 The Isotope Effect
2.11 Flux Quantization
2.12 The Concept of Coherence Length and Positive Surface Energy
2.13 Determination of Energy Gap (Single Particle Tunnelling)
2.14 The Josephson Effect (Pair Tunnelling)
2.14.1 DC Josephson Effect
2.14.2 AC Josephson Effect
2.14.3 The SQUID
2.15 Type II Superconductors—Abrikosov’s Concept of Negative Surface Energy
2.15.1 Lower and Upper Critical Magnetic Field
2.15.2 The Mixed State
2.15.3 Current Flow and Mixed State
2.15.4 Measuring Transport Critical Current
2.15.5 Magnetization in Type II Superconductors
2.15.6 Irreversible Magnetization
2.15.7 The Bean’s Critical-State Model and Magnetization
2.15.8 The Kim Model
2.15.9 Flux Creep
2.15.10 Critical Current by Magnetization Method
2.16 Surface Superconductivity—Critical Magnetic Field Bc3
2.17 Paramagnetic Limit
References
3 High-Temperature Cuprate Superconductors and Later Discoveries
3.1 Discovery of Superconductivity in La-Ba-Cu-O System (Tc = 35 K)
3.2 The Y-Ba-Cu-O (YBCO) System—First Superconductor with Tc Above 77 K
3.2.1 Method of Synthesis of YBCO
3.2.2 Some Peculiar Properties of YBCO
3.2.3 YBCO Wires and Tapes
3.3 The Bi-Sr-Ca-Cu-O (BSCCO) System
3.3.1 Bi-2223 Wires and Tapes
3.3.2 First Generation (1G)-BSCCO Current Leads
3.4 The Tl-Ba-Ca-Cu-O System
3.5 The Hg-Ba-Ca-Cu-O System
3.6 Flux Vortices, Critical Current Density and Flux Pinning in High-Tc Superconductors
3.7 Critical Surface of High-Tc Superconductors
3.8 The Depairing Current
3.9 Grain Boundary Problem in High-Tc Superconductors
3.10 Discovery of Superconductivity in Magnesium Diboride (MgB2)
3.10.1 Peculiar Properties of MgB2
3.10.2 Crystal and Electronic Structure and Energy Gaps in MgB2
3.10.3 The Boron Isotope Effect
3.10.4 Some Physical Properties of MgB2
3.10.5 Summery of the Various Properties of MgB2
3.11 The Discovery of Iron-Based Superconductors—LaFeAsO 1111 Compounds
3.11.1 High Tc (> 50 K) in Sm and Nd-Based Oxypnictides
3.11.2 Superconductivity in K-Doped BaFe2As2 122 Compounds
3.11.3 Superconductivity in Iron-Chalcogenides
3.12 Superconductivity at 203 K in Sulphur Hydride (H3S)
3.13 Superconductivity at Room Temperature (Tc = 288 K @ 267 GPa)
References
4 A Review of Theories of Superconductivity
4.1 A Chronology of Theories of Superconductivity
4.2 Londons’ Theory
4.3 The Ginzburg–Landau Theory
4.3.1 Flux Exclusion and Zero Electrical Resistance
4.3.2 Flux Quantization
4.3.3 GL—Parameter and Type II Superconductors
4.3.4 Josephson Effect
4.4 The BCS Theory of Superconductivity
4.4.1 The Cooper Pairs
4.4.2 Formulation of the Microscopic Theory
4.4.3 Transition Temperature
4.4.4 The Energy Gap
4.4.5 Critical Field and Specific Heat
4.5 Anomalous Properties of the Cuprates
4.5.1 Temperature-Hole Concentration Phase Diagram
4.5.2 Normal State Resistivity
4.5.3 Presence of Pseudo-Gap in Highly Underdoped Superconductors
4.5.4 Comparison with Conventional Metallic Superconductors
4.6 Possible Theories of HTS
4.6.1 The Resonating Valence Bond (RVB) Theory
4.6.2 The Spin Fluctuation Theory
4.6.3 Revisiting BCS Theory to Explain HTS Superconductors
4.6.4 Positive Feedback Mechanism for High-Tc Superconductivity
4.6.5 Pairing in Strongly Correlated Electron Systems
4.6.6 Three-Band d-p Model
4.7 Theories of Newly Emerged Superconductors
4.7.1 Theory of Superconductivity in MgB2
4.7.2 Theory of Iron-Based Superconductors (IBSC)
4.7.3 Superconductivity in Sulphur Hydride (H3S)
References
5 Conventional Practical Superconductors
5.1 Superconductors Useful for Magnet Application
5.2 Thermal and Electromagnetic Instability Problem—The Multifilamentary Superconductors
5.2.1 Degradation and Flux Jump
5.2.2 The Adiabatic or Intrinsic Stability
5.2.3 The Dynamic and Cryostatic Stability
5.2.4 Multifilamentary Superconducting Wires
5.2.5 Twisting and Transposition of the Multifilamentary Wires
5.3 Losses in Practical Superconductors
5.3.1 Hysteresis Losses
5.3.2 Losses Due to Filament Coupling
5.3.3 Proximity Coupling Losses
5.3.4 Losses Due to Eddy Currents
5.3.5 Losses Due to Self-field Effect
5.3.6 Losses Due to Transport Current
5.3.7 AC Losses in High Temperature Oxide Superconductors
5.4 AC Loss Measurement Methods
5.4.1 Electric Method
5.4.2 Magnetization Method
5.4.3 Calorimetric Method
5.5 Practical Superconductors—The Ubiquitous Nb-Ti Superconductor
5.5.1 Emergence of Nb-Ti as a Superconductor for Magnets
5.5.2 The Phase Diagram of Nb-Ti
5.5.3 Optimization of Jc in Nb-Ti Wires
5.5.4 Developments in the Fabrication Process of MF Cu/Nb-Ti Composite Conductors
5.5.5 Use of Diffusion Barrier and Filament Spacing
5.5.6 Nb-Ti Cable-in-Conduit Conductors (CICC)
5.6 The Discovery of A-15 Nb3Sn Superconductor
5.6.1 Emergence of Nb3Sn as High-Field Superconductor
5.6.2 The Bronze Process
5.6.3 Parameters to Be Optimized
5.6.4 Elemental Additions to Nb3Sn
5.6.5 The Internal Tin (IT) Process
5.6.6 The Jelly Roll Process
5.6.7 The Rod Restacking Process (RRP)
5.6.8 The Powder-in-Tube (PIT) Process
5.6.9 Conductor for High-Luminosity LHC Quadrupole Magnets
5.6.10 The In Situ Process
5.7 The A-15 Nb3Al MF Superconductor
5.7.1 Phase Diagram of Nb-Al System
5.7.2 Mass Production of JR Nb3Al Conductors by JAERI for ITER
5.7.3 The Rapid Heating, Quench and Transformation (RHQT) Technique
5.8 The V3Ga Tapes and Multifilamentary Wires
5.8.1 The V-Ga Binary Phase Diagram
5.8.2 V3Ga Diffusion Tapes
5.8.3 Bronze-Processed V3Ga MF Conductors
5.8.4 V3Ga Conductor by PIT Method
References
6 Practical Cuprate Superconductors
6.1 Introduction
6.2 2G REBCO Tape Wires (Coated Conductors)
6.2.1 Enhancement of Jc Through Heavy Doping
6.2.2 Development of Flexible Fine Round REBCO Wires with High Mechanical Strength
6.2.3 Next Generation High-Current REBCO STAR Wire for Compact Magnets
6.2.4 High Engineering Current Density (Je) in REBCO Wires
6.2.5 REBCO Deposition on 30 µm Hastelloy Substrate and High Je
6.2.6 High-Current CORC Cables
6.2.7 REBCO–CORC Cable-In-Conduit Conductors (CORC-CICC)
6.2.8 The Roebel Bar Cable
6.2.9 HTS CroCo Cable Development for DEMO Fusion Reactor
6.2.10 Supremacy of REBCO-Coated Conductors
6.3 The Promising Bi2Sr2CaCu2Ox (Bi-2212) Practical Wires and Cables
6.3.1 Development of a 10 kA Bi-2212 Conductor
6.3.2 Bubble Formation in PIT Bi-2212 Wire Filaments and Current Blockage
6.3.3 High Jc in Round Bi-2212 Wires Through Over-Pressure Heat Treatment
6.3.4 Isotropic Round OP Bi-2212 Wires Generate a Field of 33.6 T
6.3.5 AC Loss in Bi-2212 Cable-In-Conduit Conductors
6.3.6 PIT-OPHT Bi-2212 Rutherford Cable
6.4 The Bi-2223 Conductors
6.4.1 The Controlled Over-Pressure (CT-OP) Processed Bi-2223 Superconductors
6.4.2 Suitability of DI-Bi-2223 for High-Field Magnets
6.4.3 Low AC Loss Bi-2223 Conductors
6.4.4 A Comparison Between B-2212 and Bi-2223 Wires
References
7 Practical Magnesium Diboride (MgB2) Superconductor
7.1 Introduction
7.2 Preparation of Bulk MgB2, Single Crystal and Thin Film
7.3 MgB2 Wires, Tapes and Cables
7.3.1 Different Variants of PIT Technique—The In Situ PIT Technique
7.3.2 The Ex Situ PIT Technique
7.3.3 The Internal Magnesium Diffusion (IMD) Technique
7.3.4 Enhancement of Jc Through Optimization of Process Parameters and Doping
7.3.5 A Hybrid IMD/PIT Technique
7.4 Low AC Loss MgB2 Wires/Cables
7.5 Rutherford MgB2 Cables
7.5.1 Rutherford Cable with Al-Al2O3 Metal-Matrix Composite (MMC) Sheath
7.6 Thin Film Route for MgB2 Conductors
7.7 An Upswing in the Use of MgB2 for Applications
References
8 Iron-Based Practical Superconductors
8.1 General Features of Iron-Based Superconductors
8.2 Structure and Phase Diagrams of IBSC Compounds
8.3 Electronic and Structural Phase Diagram of LnOFeAs, 1111 Compounds
8.4 Superconductivity in LaFeCoAsO Induced by Co Doping
8.4.1 Superconductivity in Co-Doped Sm(FeCo)AsO Compounds
8.5 Phase Diagram and Characteristic Properties of (Li/Na)FeAs 111 Compounds
8.5.1 Superconductivity in Co-Doped AFeAs 111 Compounds
8.6 Phase Diagram and Characteristic Properties of 122 BaFe2As2 Compound
8.6.1 Superconductivity in K-Doped BaFe2As2 Compound
8.7 Phase Diagram of Iron Chalcogenides 11 Compounds
8.7.1 Behaviour of the Mixed Phase, Fe1+xTe1−xSex
8.8 Pressure Effect in Iron-Based Superconductors
8.8.1 Pressure Effects in 1111 Compounds
8.8.2 Pressure Effects in 111 Compounds
8.8.3 Pressure Effects in 122 Compounds
8.8.4 Pressure Effects in 11 FeSex Compounds
8.9 Critical Current in IBSC Wires and Tapes
8.9.1 Fabrication of Wires/Tapes Through PIT Technique
8.9.2 Achieving High Jc in IBSC 122 Wires/Tapes
8.9.3 Multifilamentary IBSC Wires/Tapes for Applications
8.9.4 The Thin Film Route
References
9 Building Laboratory Superconducting Magnets and Present Status of High-Field Magnets
9.1 Introduction
9.2 Evolution of Superconducting Magnets
9.3 Unique Features of a Superconducting Magnet
9.4 Design Considerations of a Solenoid Magnet
9.4.1 Specific Example of a 7 T Superconducting (Nb–Ti) Magnet
9.4.2 Optimization of Vapour-Cooled Current Leads
9.4.3 Magnet Quench
9.4.4 The Minimum Propagating Zone
9.4.5 Quench Voltage and Temperature Rise
9.4.6 Quench Protection
9.4.7 The Persistent Switch
9.4.8 Training of the Magnet
9.5 High Homogeneity Field
9.5.1 High Homogeneity Field by Compensated Coils
9.6 An 11 T Nb–Ti/Nb3Sn Combination Magnet
9.6.1 Winding the Background Nb–Ti Magnet
9.6.2 Winding the Nb3Sn Magnet
9.6.3 Preparation of Current Terminals
9.6.4 Heat Treatment and Impregnation
9.6.5 Assembly of Magnet Coils and Operation
9.7 Intense Field Magnets
9.7.1 A 21.1 T Superconducting Magnet Built by NIMS
9.7.2 A 24 T Magnet Using GdBCO Insert Coil (NIMS)
9.7.3 A 26.8 T YBCO Insert Coil at NHMFL (FSU)
9.7.4 A Record Field of 32 T at NHMFL (FSU)
9.7.5 A New World Record of Magnetic Field—45.5 T at NHMFL (FSU)
9.7.6 First High Current (4 kA) Insert Magnet Wound with CORC® Cable
9.8 Cryo-Free Superconducting Magnets (CFSM)
9.8.1 Important Considerations for CFSM System Design
9.8.2 The Design and Winding of the Magnet
9.8.3 The Current Lead Design
9.8.4 The Cryostat Design
9.8.5 Operating the Magnet
References
10 Superconducting Magnets in Accelerators
10.1 The Accelerators
10.2 Role of Superconducting Magnets in Accelerators
10.3 High-Energy Accelerators Using Superconducting Magnets
10.3.1 Tevatron (FNAL, USA)
10.3.2 Hadron Electron Ring Accelerator (HERA), DESY, Hemberg, Germany
10.3.3 Superconducting Super Collider (SSC), Texas, USA (Abandoned)
10.3.4 Relativistic Heavy Ion Collider (RHIC), BNL, Upton, USA
10.3.5 Large Hadron Collider (LHC), CERN (Switzerland/France)
10.4 Unique Features of the Accelerator Magnets with Special Reference to LHC
10.4.1 The Coil Geometry
10.4.2 The Collars
10.4.3 The Yoke
10.4.4 The Magnets
10.4.5 Training of Magnets
10.4.6 The Quench Protection
10.5 High-Field Magnets for Future Accelerators
10.5.1 The Nb3Sn Conductor for Accelerator Magnets
10.5.2 Nb3Sn Accelerator Magnets Development at FNAL
10.5.3 EuCARD Nb3Sn Dipole Magnets
10.6 Common Coil High-Field Dipole Magnets—A New Approach (LBNL)
10.7 The 15 T HD-2 Dipole
10.8 Work on the Design of 15 T Nb3Al Dipole
10.9 Linear Colliders with Special Reference to ILC
10.9.1 Superconducting Magnets in ILC
10.9.2 The ILC Quadrupole and Dipole Correctors
10.9.3 The Wiggler Magnets
10.9.4 The Undulator
10.9.5 Other Superconducting Magnets
10.10 Superconducting Magnets in Cyclotron
10.10.1 Cyclotron Magnet
10.10.2 Some Landmark Superconducting Cyclotrons
10.10.3 K-500 Cyclotron at NSCL (Michigan State University)
10.10.4 K-500 Cyclotron (VECC, Kolkata)
10.10.5 K-1200 Cyclotron (NSCL, MSU)
10.10.6 K-2500, RIKEN Superconducting Ring Cyclotron
10.11 New Developments in Accelerator and Magnet Technology
10.11.1 The High-Luminosity–Large Hadron Collider (HL-LHC)
10.11.2 Factors Influencing the Specific Parameters of Dipole and Quadrupole Magnets
10.11.3 Testing of Nb3Sn Quadrupole and Dipole Magnets for High HL-LHC
10.12 Future Circular Collider (FCC)
10.12.1 Magnet Technology for FCC-Hh
10.13 The High-Energy 28 TEV Large Hadron Collider (HE-LHC)
10.13.1 Emergence of Supercable-In-Conduit Conductors (SuperCICC) for High-Field Accelerator Magnets
10.13.2 The HE-LHC Dipoles in Hybrid formation—A New Concept
10.14 The State-of-the-Art Electron–Ion Collider (EIC)—A Discovery Machine
10.14.1 ERHIC—The Electron–Ion Collider at Brookhaven National Laboratory
10.14.2 The Jefferson Lab Electron–Ion Collider (JLEIC)
10.14.3 Magnets in the Interaction Region (IR) of the JLEIC
10.14.4 Modular Quadrupole Design for EIC
10.14.5 Passive Superconducting Shield for Magnets in EIC
References
11 Superconducting Magnets in Fusion Reactors
11.1 The Fusion Reaction
11.2 Plasma Ignition
11.3 Plasma Confinement
11.3.1 The Inertial Confinement
11.3.2 The Magnetic Confinement
11.3.3 Magnetic Mirror
11.3.4 The Stellarator
11.3.5 The Tokamak
11.3.6 Magnetic Field in a Tokamak
11.4 Important Superconducting Tokamaks
11.4.1 Tokamak Development in USSR/Russia
11.4.2 The Russian Hybrid Fusion–Fission Reactor
11.4.3 TFTR (Tokamak Fusion Test Reactor, Non-superconducting), PPPL, USA
11.4.4 JET (Joint European Torus), Non-superconducting (Culham, UK)
11.4.5 Mega Ampere Spherical Tokamak (MAST) Upgrade
11.4.6 Tore Supra (NRC, Cadarache, France)
11.4.7 WEST (Tungsten (W) Environment in Steady-State Tokamak)
11.4.8 JT-60 SA (Japan Torus-60 Super Advance), JAERI, Naka, Japan
11.4.9 KSTAR (Korean Superconducting Tokamak Reactor), NFRI, Daejeon
11.4.10 K-DEMO Being Built by Korea and PPPL
11.4.11 EAST (Experimental Advance Superconducting Tokamak, IPP, China)
11.4.12 HL-2M Tokamak—A New Tokamak Built by China
11.4.13 CFETR (China Fusion Engineering Testing Reactor)—A Power-Producing Tokamak
11.4.14 SST-1 (Steady-State Superconducting Tokamak-1), IPR, India
11.4.15 SST-2 (Steady-State Tokamak-2) Fusion Reactor, IPR, India
11.5 The International Thermonuclear Experimental Reactor (ITER)
11.5.1 The ITER Design
11.5.2 The TF Coil Winding Pack
11.5.3 The PF Coil Winding Pack
11.5.4 The CS Coils
11.5.5 Final Assembly of ITER
11.5.6 HTS Hybrid Current Leads for ITER
11.6 The Stellarator, W7-X (Wendelstein 7-X) Greifswald, Germany
11.6.1 The Magnet System of W7-X
11.6.2 Bus Bars and HTS Hybrid Current Leads
11.6.3 Performance Tests on Wendelstein 7-X
11.6.4 Wendelstein 7-X Upgrade to Divertor Stage
11.7 IGNITOR (Italian–Russian Collaboration), ITP, TRINITI, Russia
References
12 Other Applications of Superconducting Magnets
12.1 Introduction
12.2 Nuclear Magnetic Resonance (NMR)
12.2.1 Salient Features of an NMR Magnet and the Present Status
12.2.2 The Magnet and Shim Coil Design
12.2.3 Jointing of the Wires
12.2.4 Bruker’s ‘UltraStabilized™’ Cryostat for 2 K Operation
12.2.5 Another World Record in NMR Magnet in 2015
12.2.6 A New World Record of 1.2 GHz NMR Magnet System by Bruker BioSpin (2020)
12.2.7 JEOL’s ‘Zero Boil-Off Magnet for NMR System’
12.2.8 A Split NMR Magnet System
12.2.9 Superconducting Magnet (30.5 T) for a 1.3 GHz NMR Spectrometer
12.3 Magnets in Magnetic Resonance Imaging (MRI)
12.3.1 The Elements of an MRI Scanner
12.3.2 Evolution of MRI Magnet design—A Brief Description
12.3.3 Compensated Solenoid Magnet Design
12.3.4 Multicoil Magnet Design
12.3.5 Design of Cryogen-Free MgB2 Magnets for MRI
12.3.6 A Mini Conduction-Cooled 1.5 T MgB2 Finger MRI Magnet at MIT
12.3.7 Solid-Cryogen Cooling of NMR and MRI Magnets
12.3.8 Some Recent Developments in MRI Scanners
12.4 Superconducting High-Gradient Magnetic Separator (SHGMS)—Principle of Magnetic Separation
12.4.1 SHGMS Magnet Design
12.4.2 Recent Developments of SHGMS
12.4.3 Superconducting Pulsating High-Gradient Magnetic Separator (SP-HGMS)
12.5 Superconducting Magnet Energy Storage (SMES)
12.5.1 Magnet Design in SMES
12.5.2 Factors Affecting SMES
12.5.3 Some Examples of SMES
12.5.4 High-Tc Superconductor (HTS) SMES
12.6 Maglev and Rotating Machines
12.6.1 Magnetic Levitation (Maglev)
12.6.2 Motors and Generators
References
Index