Superconductivity Magnetism And Magnets

Superconductivity is the ability of certain materials to conduct electrical current with no resistance and extremely low losses. High temperature superconductors, such as La2-xSrxCuOx (Tc=40K) and YBa2Cu3O7-x (Tc=90K), were discovered in 1987 and have been actively studied since. In spite of an intense, world-wide, research effort during this time, a complete understanding of the copper oxide (cuprate) materials is still lacking. Many fundamental questions are unanswered, particularly the mechanism by which high-Tc superconductivity occurs. More broadly, the cuprates are in a class of solids with strong electron-electron interactions. An understanding of such "strongly correlated" solids is perhaps the major unsolved problem of condensed matter physics with over ten thousand researchers working on this topic. High-Tc superconductors also have significant potential for applications in technologies ranging from electric power generation and transmission to digital electronics. This ability to carry large amounts of current can be applied to electric power devices such as motors and generators, and to electricity transmission in power lines. For example, superconductors can carry as much as 100 times the amount of electricity of ordinary copper or aluminium wires of the same size. Many universities, research institutes and companies are working to develop high-Tc superconductivity applications and considerable progress has been made. This volume brings together new leading-edge research in the field.

The main topic of the book are the superconducting dipole and quadrupole magnets needed in high-energy accelerators and storage rings for protons, antiprotons or heavy ions. The basic principles of low-temperature superconductivity are outlined with special emphasis on the effects which are relevant for accelerator magnets. Properties and fabrication methods of practical superconductors are described. Analytical methods for field calculation and multipole expansion are presented for coils without and with iron yoke. The effect of yoke saturation and geometric distortions on field quality is studied. Persistent magnetization currents in the superconductor and eddy currents the copper part of the cable are analyzed in detail and their influence on field quality and magnet performance is investigated. Superconductor stability, quench origins and propagation and magnet protection are addressed. Some important concepts of accelerator physics are introduced which are needed to appreciate the demanding requirements on field quality in large storage rings. The operational experience with the superconducting HERA collider serves as an illustration. Finally superconducting correction coils and practical construction and fabrication methods of accelerator magnets are discussed. The physical and technical principles described in the book are substantiated with a wealth of experimental data on multipoles, persistent- and eddy-current effects, quench performance and much more. Contents:IntroductionBasics of SuperconductivityPractical Superconductors for Accelerator MagnetsField CalculationsMechanical Accuracies and Magnetic ForcesPersistent CurrentsEddy Current Effects in Superconducting MagnetsQuenches and Magnet ProtectionImpact of Field Errors on Accelerator Performance and Correction SchemesConstruction Methods of Superconducting Accelerator MagnetsA Techniques of Multipole MeasurementsStretched-Wire System for Quadrupole MeasurementsPassive Superconductor Magnetization in Beam-Pipe CoilsApproximate Relations for NbTi Critical ParametersHelium PropertiesMaterial Properties of KaptonCollar and Yoke Material Properties Readership: Engineers, research scientists and applied physicists. keywords:

The 2nd edition emphasizes two areas not emphasized in the 1st edition: 1) high-temperature superconductor (HTS) magnets; 2) NMR (nuclear magnetic resonance) and MRI (magnetic resonance imaging) magnets. Despite nearly 40 years of R and D on superconducting magnet technology, most areas, notably fusion and electric power applications, are still in the R and D stage. One exception is in the area of NMR and MRI. NMR magnets are very popular among chemists, biologists, genome scientists, and most of all, by drug manufacturers for drug discovery and development. MRI and NMR magnets have become the most successful application of superconducting magnet technology and this trend should continue. The 2nd edition will have new materials never treated formally in any other book of this kind. As with the 1st, most subjects will be presented through problem format to educate and train the designer.

This up-to-date work presents a modern vision of magnetism and superconductivity covering both microscopic and phenomenological aspects. The basic information is illustrated with the help of current research topics such as the quantum Hall effect or mesoscopic aspects of superconductivity.

Designed for graduate students in mechanical engineering, this textbook discusses the basic concepts of superconducting magnet technology. Important topics covered include field distribution, magnets, force, thermal stability, dissipation, and protection. To help the students excel in the field, each chapter contains tutorial problems, accompanied by solutions, utilizing solenoidal magnets as examples.

This book presents the basics and applications of superconducting magnets. It explains the phenomenon of superconductivity, theories of superconductivity, type II superconductors and high-temperature cuprate superconductors. The main focus of the book is on the application to superconducting magnets to accelerators and fusion reactors and other applications of superconducting magnets. The thermal and electromagnetic stability criteria of the conductors and the present status of the fabrication techniques for future magnet applications are addressed. The book is based on the long experience of the author in studying superconducting materials, building magnets and numerous lectures delivered to scholars. A researcher and graduate student will enjoy reading the book to learn various aspects of magnet applications of superconductivity. The book provides the knowledge in the field of applied superconductivity in a comprehensive way.