Superconductivity And Electromagnetism

This book introduces readers to the characteristic features of electromagnetic phenomena in superconductivity. It first demonstrates not only that the diamagnetism in the superconductivity complies with Maxwell’s theory, which was formulated before the discovery of superconductivity, but also that the dominant E-B analogy in the electromagnetism loses perfection without the superconductivity. The book then explores flux pinning, which is responsible for the non-dissipative current in DC, leading to irreversibility in AC. Drawing on Maxwell’s work, it also proves theoretically that if there is no energy dissipation in the superconductivity caused by the break in time reversal symmetry, it contradicts the thermodynamic principle of energy conservation – something that had previously only been proved experimentally. Lastly, the book addresses the longitudinal magnetic field effect, and explains how this phenomenon leads to a new development of Maxwell’s theory. Featuring numerous appendices to help readers understand the methods of derivation of equations, this book offers students and young scientists an introduction to applied superconductivity, especially in the context of power applications. Presenting the characteristic features of electromagnetic phenomena in superconductivity from basic to advanced topics for applications, the book offers a valuable resource for graduate students and researchers studying superconductivity as well as engineers working in electric utility industry.

This book presents a unified and comprehensive theoretical treatment of electromagnetic, thermal and mechanical phenomena in superconductors. Introduces basic concepts and principles with particular emphasis on general methodology.

This book is a very comprehensive textbook covering in great depth all the electricity and magnetism. The 2nd edition includes new and revised figures and exercises in many of the chapters, and the number of problems and exercises for the student is increased. In the 1st edition, emphasis much was made of superconductivity, and this methodology will be continued in the new edition by strengthening of the E-B analogy. Many of the new exercises and problems are associated with the E-B analogy, which enables those teaching from the book to select suitable teaching methods depending on the student’s ability and courses taken, whether physics, astrophysics, or engineering. Changes in the chapters include a detailed discussion of the equivector-potential surface and its correspondence between electricity and magnetism. The shortcomings of using the magnetic scalar potential are also explained. The zero resistivity in a magnetic material showing perfect diamagnetism can be easily proved. This textbook is an ideal text for students, who are competent in calculus and are taking physics, astrophysics, or engineering at degree level. It is also useful as a reference book for the professional scientist.

With contributions by numerous experts

In 1987 a major breakthrough occurred in materials science. A new family of materials was discovered that became superconducting above the temperature at which nitrogen gas liquifies, namely, 77 K or –196°C. Within months of the discovery, a wide variety of experimental techniques were brought to bear in order to measure the properties of these materials and to gain an understanding of why they superconduct at such high temperatures. Among the techniques used were electromagnetic absorption in both the normal and the superconducting states. The measurements enabled the determination of a wide variety of properties, and in some instances led to the observation of new effects not seen by other measu- ments, such as the existence of weak-link microwave absorption at low dc magnetic fields. The number of different properties and the degree of detail that can be obtained from magnetic field- and temperature-dependent studies of electromagnetic abso- tion are not widely appreciated. For example, these measurements can provide information on the band gap, critical fields, the H–T irreversibility line, the amount of trapped flux, and even information about the symmetry of the wave function of the Cooper pairs. It is possible to use low dc magnetic field-induced absorption of microwaves with derivative detection to verify the presence of superconductivity in a matter of minutes, and the measurements are often more straightforward than others. For example, they do not require the physical contact with the sample that is necessary when using four-probe resistivity to detect superconductivity.

Nonlinear Diffusion of Electromagnetic Fields covers applications of the phenomena of non-linear diffusion of electromagnetic fields, such as magnetic recording, electromagnetic shielding and non-destructive testing, development of CAD software, and the design of magnetic components in electrical machinery. The material presented has direct applications to the analysis of eddy currents in magnetically nonlinear and hysteretic conductors and to the study of magnetization processes in electrically nonlinear superconductors. This book will provide very valuable technical and scientific information to a broad audience of engineers and researchers who are involved in these diverse areas. Contains extensive use of analytical techniques for the solution of nonlinear problems of electromagnetic field diffusion Simple analytical formulas for surface impedances of nonlinear and hysteretic media Analysis of nonlinear diffusion for linear, circular and elliptical polarizations of electromagnetic fields Novel and extensive analysis of eddy current losses in steel laminations for unidirectional and rotating magnetic fields Preisach approach to the modeling of eddy current hysteresis and superconducting hysteresis Extensive study of nonlinear diffusion in superconductors with gradual resistive transitions (scalar and vertorial problems)

This iconoclastic book proposes that superconductivity is misunderstood in contemporary science and that this hampers scientific and technological development. Superconductivity is the ability of some metals to carry electric current without resistance at very low temperatures. Properly understanding superconductivity would facilitate finding materials that superconduct at room temperature, providing great benefits to society.The conventional BCS theory of superconductivity, developed in 1957 and awarded the Nobel Prize in 1972, is generally believed to fully explain the lower temperature 'conventional superconductors' but not the more recently discovered 'high temperature superconductors', for which the charge carriers are positive Holes rather than negative electrons. Instead, this book proposes the holistic view that Holes are responsible for superconductivity in all materials. It explains in simple terms how the most fundamental property of all superconductors, that they expel H-fields (the Meissner effect), can be understood with Hole carriers and cannot be explained by BCS. It describes the historical development of the conventional theory and why it went astray, and credits pre-BCS researchers for important insights that were forgotten after BCS but are in fact relevant for the proper understanding of superconductivity.The book's author, Jorge E Hirsch, is a renowned expert in the field of condensed matter physics who has published over 250 articles on the subject. He has developed the theory of 'Hole superconductivity', the focus of this book, over the last 30 years. He is also the inventor of the H-index, a bibliometric measure of scientific impact which, he admits in this book, fails to identify high scientific achievement in the field of superconductivity.

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.