Numerical Modelling of Bulk Superconductor Magnetisation

TABLE OF CONTENTS

CHAPTER 1: Foreword/introduction

CHAPTER 2: Fundamentals of bulk superconducting materials

2.1 Bulk superconductors
2.2 Magnetic properties of bulk superconductors
2.2.1 Superconducting material classifications
2.2.1.1 Low- and high-temperature superconducting materials
2.2.1.2 Type I and II superconductivity
2.2.1.3 Irreversibility field
2.2.2 Flux pinning and field trapping
2.2.3 Flux creep
2.3 Fabrication processes
2.3.1 Bulk (RE)BCO superconductors
2.3.2 Bulk MgB2 superconductors
2.3.3 Bulk iron-pnictide superconductors
2.4 Magnetisation of bulk superconductors
2.4.1 Pulsed field magnetisation
2.5 Bulk superconductor applications
2.5.1 Flux pinning applications
2.5.1.1 Levitation
2.5.1.2 Magnetic bearings, flywheel energy storage and superconducting mixers
2.5.2 Flux trapping applications
2.5.2.1 Magnetic separation
2.5.2.2 Rotating machines
2.5.2.3 Portable NMR/MRI systems
2.5.2.4 Lorentz force velocimetry
2.5.2.5 Other applications
2.5.3 Flux shielding applications
2.5.4 Magnetic lens
2.5.5 Conductor alternative

CHAPTER 3: Numerical modelling of bulk superconducting materials

3.1 Modelling of bulk superconductors
3.1.1 Analytical techniques
3.1.2 Numerical techniques
3.2 Finite element method
3.2.1 Modelling bulk superconductors using FEM
3.2.1.1 Geometry, including magnetisation fixture
3.2.1.2 Electromagnetic formulation
3.2.1.2.1 H-formulation
3.2.1.3 Electrical properties
3.2.1.3.1 Critical current density, Jc(B, T)
3.2.1.3.2 E-J power law
3.2.1.3.3 Electromagnetic boundary conditions
3.2.1.4 Thermal properties & electromagnetic-thermal coupling

CHAPTER 4: Modelling magnetisation of bulk superconductors

4.1 Magnetisation of bulk superconductors
4.1.1 Zero-field-cooled (ZFC) & field-cooled (FC) magnetisation
4.1.1.1 Simulation of ZFC magnetisation
4.1.1.2 Simulation of FC magnetisation
4.1.1.3 Case study #1: MgB2 bulks
4.1.1.4 Case study #2: Iron-pnictide bulks
4.1.2 Pulsed field magnetisation
4.1.2.1 Basic model
4.1.2.2 Influence of PFM parameters on trapped fields
4.1.2.3 Case study #3: PFM of bulk HTS materials using a split coil with an iron yoke

CHAPTER 5: Demagnetisation & novel, hybrid bulk superconductor structures

5.1 Demagnetisation effects & AC losses
5.2 Novel & hybrid bulk superconductor structures
5.2.1 Composite structures with improved thermal conductivity
5.2.2 Hybrid ferromagnet-superconductor structures
5.2.3 Hollow bulk cylinders & tubes for shielding
5.2.4 Hybrid trapped field magnet lens

APPENDIX A: Thermal properties of bulk superconductors

A.1 Introduction
A.2 Experimental procedure
A.2.1 Thermal conductivity
A.2.2 Thermal dilatation
A.3 Typical results
A.3.1 Bulk (RE)BCO
A.3.1.1 Thermal conductivity
A.3.1.2 Thermal conductivity in magnetic fields
A.3.1.3 Thermal dilatation
A.3.2 Bulk MgB2
A.3.2.1 Thermal conductivity
A.3.2.2 Thermal dilatation