Discovering Superconductivity E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 154

Veröffentlichungsjahr: 2012

Beschreibung

Superconductivity is a quantum phenomenon that manifests itself in materials showing zero electrical resistance below a characteristic temperature resulting in the potential for an electric current to run continually through such a material without the need for a power source. Such materials are used extensively in medical and power applications, e.g. MRI and NMR machines.

Discovering Superconductivity uses a series of practical and investigative activities, which can be used as tutor demonstrations or as student lab exercises.

This highly illustrated text features the following sections:

• Introduction - including a brief history of superconductivity
• Superconductivity - an explanation of the phenomenon and its effects
• Superconducting materials – including High & Low temperature   superconductors
• Applications – how superconductivity is used in medical imaging, at CERN and in the Maglev trains

This text will serve as an excellent introduction for students, with or without a physics background, to superconductivity. With a strong practical, experimental emphasis, it provides readers with an overview of the topic preparing them for more advanced texts used in advanced undergraduate and post-graduate courses.

PowerPoint files of the figures presented within this text are available at: booksupport.wiley.com

A word from the author: "The intention of this text is to introduce the reader to the study of superconductivity via a minds-on approach .... The minds-on approach takes this a stage further by requiring the learner to engage with the process to a greater extent."

Leseprobe

Contents

Cover

Title Page

Copyright

List of Figures

List of Tables

Preface

Acknowledgements

To the Teacher

To the Student

Section I: Introduction

Chapter 1: Resistivity and Conduction in Metals

1.1 INTRODUCTION

1.2 RESISTIVITY

1.3 CONDUCTION IN METALS

1.4 REVISITING OHM'S LAW

Chapter 2: A Brief History of Superconductivity

2.1 INTRODUCTION

2.2 THE BEGINNING: KWIK NAGENOEG NUL

2.3 1933 – PERFECT DIAMAGNETISM?

2.4 THE LONDON BROTHERS

2.5 1957 – THE BCS THEORY

2.6 1962 – THE JOSEPHSON EFFECT

2.7 1986 – BEDNORZ AND MüLLER AND OXIDE SUPERCONDUCTORS

2.8 2003 – ABRIKOSOV, GINZBURG AND LEGGETT – AND THE FUTURE

2.9 GETTING COLD ENOUGH

Section II: Superconductivity

Chapter 3: An Explanation of Superconductivity?

3.1 TRANSITION TEMPERATURE

3.2 TWO-FLUID MODEL

3.3 CRITICAL FIELD, CRITICAL CURRENT

3.4 SCHAWLOW AND DEVLIN

3.5 THE LONDON EQUATION

3.6 BCS THEORY

3.7 AN ALTERNATIVE APPROACH TO THE ENERGY GAP

Chapter 4: The Meissner–Ochsenfeld Effect

Chapter 5: Diamagnetic Effects

5.1 DIAMAGNETISM, PARAMAGNETISM AND FERROMAGNETISM

Chapter 6: Persistence of Current

6.1 QUINN AND ITTNER

Chapter 7: Type I and Type II Superconductors

7.1 CRITICAL MAGNETIC FIELD

Chapter 8: Flux Pinning

8.1 VORTEX AND FLUX LINES

8.2 THE ORIGINAL ABRIKOSOV

Section III: Superconducting Materials

Chapter 9: Low-Temperature Superconductors

Chapter 10: Organic Superconductors

Chapter 11: High-Temperature Superconductors

11.1 MAGNESIUM DIBORIDE

11.2 TRANSITION TEMPERATURE OF HIGH-Tc SUPERCONDUCTORS

Section IV:

Chapter 12: Superconducting Wire

Chapter 13: Medical Imaging

13.1 MAGNETIC RESONANCE IMAGING (MRI)

13.2 MAGNETOENCEPHALOGRAPHY

Chapter 14: CERN and the LHC

Chapter 15: Maglev Trains

Appendices

Appendix A: The BCS Theory

Appendix B: Flux Penetration

Appendix C: The Josephson Junction and the SQUID

Appendix D: MRI

GENERATING THE MRI SIGNAL

Appendix E: A Note on Superfluidity

Appendix F: A Note on Safety

Index

This edition first published 2012 © 2012 John Wiley & Sons, Ltd

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Library of Congress Cataloging-in-Publication Data

Ireson, Gren. Discovering superconductivity : an investigative approach / Gren Ireson. p. cm. Includes index. ISBN 978-1-119-99141-0 (hardback) – ISBN 978-1-119-99140-3 (paper) 1. Superconductivity–Study and teaching (Higher)–Activity programs. I. Title. QC611.96.I74 2012 537.6′23076–dc23 2012017363

A catalogue record for this book is available from the British Library.

HB ISBN: 978-111-999-1410 PB ISBN: 978-111-999-1403

List of Figures

1.1    Resistivity in terms of resistance, length and cross-sectional area

1.2    Using conducting putty

1.3    A macroscopic view of drift velocity

1.4    Distribution of molecular speeds at various temperatures

2.1    Heike Kamerlingh Onnes

2.2    Theories on the variation in resistance with temperature

2.3    The historic plot

2.4    Expulsion of a magnetic field by a superconductor

2.5    A visual model of the Cooper pairs

2.6    Tunnelling of the Cooper pairs

2.7    Stylised dilution cryostat

2.8    Phase diagram for 3He–4He mixture

2.9    Development of superconductors

3.1    Measuring V and I for a superconductor

3.2    A four-point probe with a thermocouple

3.3    Setting up the four-point probe to measure Tc

3.4    Estimation of transition temperature

3.5    Variation in critical magnetic field with temperature

3.6    Penetration of the magnetic field

3.7    Variation in penetration depth with temperature for tin

3.8    Cooper pairs

3.9    Cooper pairs in a crystal lattice

3.10    Energy gap

3.11    Density state illustration of a superconductor–insulator– superconductor (SIS) system