* Electron optics involves the influence of electric and magnetic fields on electron beams. In those electron optical instruments utilizing magnetic fields, a replacement of the conventional, i.e .. nonsuperconducting, electron optical parts, is worth considering if the outstanding magnetic properties of superconductors can improve the systems. However, the use of superconductors demands complicated cryogenic techniques and this, of course, dampens enthusiasm. There are fields, however, where there are extreme requirements on the optical systems, namely, electron microscopy and high-energy physics. The great advantage of the combination of electron optics and superconductivity in these domains has been demonstrated in recent experiments. This monograph is mainly concerned with electron micros copy. Superconductivity in high-energy electron optics is treated only briefly, in Appendix A, since the author is little acquainted with the details of the projects. Furthermore, the number of experiments as yet carried out is small. In Appendix B, electron microscope studies of basic superconductor phenomena are reviewed. This material is included, even though it is only slightly connected with the main topic of the book, since a breakthrough in this field may be possible by the application of superconducting lenses.

Treatise on Materials Science and Technology, Volume 14: Metallurgy of Superconducting Materials covers the practical use of metallurgy of superconducting materials. The book discusses the phenomenon of superconductivity; the theory of superconductors; the applications of superconductivity and the demands these applications make on materials' properties and requirements. The text also describes the metallurgy of niobium-titanium alloy conductors; the physical metallurgy of A15 compounds; and the electron microscopy of superconducting materials. The metallurgy of conductors made from A15 material, the properties required, as well as the development of superconductors for ac power transmission are considered. The book further tackles the metallurgy of niobium surfaces, and the effects of radiation on superconductors. Metallurgists, physicists, materials scientists, materials engineers, and graduate students studying superconductors will find the book invaluable.

This new fourth edition of the standard text on atomic-resolution transmission electron microscopy (TEM) retains previous material on the fundamentals of electron optics and aberration correction, linear imaging theory (including wave aberrations to fifth order) with partial coherence, and multiple-scattering theory. Also preserved are updated earlier sections on practical methods, with detailed step-by-step accounts of the procedures needed to obtain the highest quality images of atoms and molecules using a modern TEM or STEM electron microscope. Applications sections have been updated - these include the semiconductor industry, superconductor research, solid state chemistry and nanoscience, and metallurgy, mineralogy, condensed matter physics, materials science and material on cryo-electron microscopy for structural biology. New or expanded sections have been added on electron holography, aberration correction, field-emission guns, imaging filters, super-resolution methods, Ptychography, Ronchigrams, tomography, image quantification and simulation, radiation damage, the measurement of electron-optical parameters, and detectors (CCD cameras, Image plates and direct-injection solid state detectors). The theory of Scanning transmission electron microscopy (STEM) and Z-contrast are treated comprehensively. Chapters are devoted to associated techniques, such as energy-loss spectroscopy, Alchemi, nanodiffraction, environmental TEM, twisty beams for magnetic imaging, and cathodoluminescence. Sources of software for image interpretation and electron-optical design are given.

The aim of this book is to outline the physics of image formation, electron specimen interactions and image interpretation in transmission electron mic roscopy. The book evolved from lectures delivered at the University of Munster and is a revised version of the first part of my earlier book Elek tronenmikroskopische Untersuchungs- und Priiparationsmethoden, omitting the part which describes specimen-preparation methods. In the introductory chapter, the different types of electron microscope are compared, the various electron-specimen interactions and their applications are summarized and the most important aspects of high-resolution, analytical and high-voltage electron microscopy are discussed. The optics of electron lenses is discussed in Chapter 2 in order to bring out electron-lens properties that are important for an understanding of the function of an electron microscope. In Chapter 3, the wave optics of elec trons and the phase shifts by electrostatic and magnetic fields are introduced; Fresnel electron diffraction is treated using Huygens' principle. The recogni tion that the Fraunhofer-diffraction pattern is the Fourier transform of the wave amplitude behind a specimen is important because the influence of the imaging process on the contrast transfer of spatial frequencies can be described by introducing phase shifts and envelopes in the Fourier plane. In Chapter 4, the elements of an electron-optical column are described: the electron gun, the condenser and the imaging system. A thorough understanding of electron-specimen interactions is essential to explain image contrast.

I am indeed pleased to prepare this brief foreword for this book, written by several of my friends and colleagues in the Soviet Union. The book was first published in the Russian language in Moscow in 1975. The phenomenon of superconductivity was discovered in 1911 and promised to be important to the production of electromagnets since superconductors would not dissipate Joule heat. Unfortunate ly the first materials which were discovered to be superconducting reverted to the normal resistive state in magnetic fields of a few tesla. Thus the development that was hoped for by hundredths of a the early pioneers was destined to be delayed for over half a century. In 1961 the intermetallic compound NbaSn was found to be superconducting in a field of about 200 teslas. This breakthrough marked a turning point, and 50 years after the discovery of superconductivity an intensive period of technological development began. There are many applications of superconductivity that are now being pursued, but perhaps one of the most important is super conducting magnetic systems. There was a general feeling in the early 1960s that the intermetallic compounds and alloys that were found to retain superconductivity in the presence of high magnetic fields would make the commercialization of superconducting magnets a relatively simple matter. However, the next few years were ones of disillusionment; large magnets were found to be unstable, causing them to revert to the normal state at much lower magnetic fields than predicted.

Scope and Purpose Although conductors based on the Al5 intermetallic compound Nb Sn 3 possess desirable high-field superconducting properties, manufacturing and handling difficulties, coupled with the tendency of their critical current densities to degrade rapidly under stress, have generally restricted their use to fairly straightforward, usually small-scale solenoidal-magnet applica tions. Likewise the Al5 compound VGa, which has a wider critical strain 3 window than NbSn but a uniformly lower upper critical field, has not 3 entered widespread service. Strain has been found to have no measurable influence on either the critical fields or the critical current densities of compound superconductors with BI and Cl5 crystal structures, but as yet they are still in the research and development stages. On the other hand, conductors using the binary alloy Ti-Nb or multi component alloys based on it, because of their relative ease of manufacture, excellent mechanical properties, and relatively low strain sensitivities, are now being pressed into service in numerous large-scale devices. Such conductors are being wound into magnets for use in energy storage, energy conversion (i. e. , generators and motors), and high-energy particle detectors and beam-handling magnets. of cold-rolled or drawn Ti-Nb-alloy wire for superconducting The use magnet applications was first proposed in 1961. During the ensuing ten years, while progress was being made in the development of Cu-clad filamentary-Ti-Nb-alloy conductors, Ti-Nb and other Ti-base binary transi tion-metal (TM) alloys were being employed as model systems in the fundamental study of type-II superconductivity.

This is a benchmark reference work on Cryogenic Engineering which chronicles the major developments in the field. Starting with an historical background, this book reviews the development of data resources now available for cryogenic fields and properties of materials. It presents the latest changes in cryopreservation and the advances over the past 50 years. The book also highlights an exceptional reference listing to provide referral to more details.

At least 10 years have elapsed since a comprehensive monograph concer ned with the broad subject of cryogenics has been published. During this time a considerable quantity of research and development has been carried out in the field of cryogenics. Furthermore, there has been a certain degree of redirection of effort within the field, mostly driven by the variety of new applications, ranging from superconductive magnet systems to micro electronics. Greater emphasis is now being placed on low-temperature cryogenics, particularly that of liquid helium. Until now cryogenic books have provided a broad survey of materials and fluid properties over the entire cryogenic regime, T ::5 150 K. This approach does not allow sufficient detail in any particular area to bring the reader to the current level of understanding in the subject. In addition, the behavior of helium has been lumped with that of other cryogenic fluids, although the properties of helium are quite unique. As a result, a clear relationship has not been established between the fundamental understanding of helium fluids and their potential applications. The present book has been written to fill this void. The approach is to survey the field of cryogenics, specifically as it pertains to helium fluids. This approach is more specialized than that contained in previous cryogenics books. Furthermore, the level of treatment is more advanced and a certain knowledge of fundamental engineering and physics principles has been assumed.