Nearly all of this book is taken from an article prepared for a volume of the Encyclopedia of Physics. This article, in turn, is partly based on Dr. Norbert Rosenzweig's translation of an older article on the same subject, written by one of us (H.A.B.) about 25 years ago for the Geiger-Scheel Handbuch der Physik. To the article written last year we have added some Addenda and Errata. These Addenda and Errata refer back to some of the 79 sections of the main text and contain some misprint corrections, additional references and some notes. The aim of this book is two-fold. First, to act as a reference work on calcu lations pertaining to hydrogen-like and helium-like atoms and their comparison with experiments. However, these calculations involve a vast array of approxi mation methods, mathematical tricks and physical pictures, which are also useful in the application of quantum mechanics to other fields. In many sections we have given more general discussions of the methods and physical ideas than is necessary for the study of the H- and He-atom alone. We hope that this book will thus at least partly fulfill its second aim, namely to be of some use to graduate students who wish to learn "applied quantum mechanics". A basic knowledge of the principles of quantum mechanics, such as given in the early chapters of Schiff's or Bohm's book, is presupposed.

This monograph gives a detailed introductory exposition of research results for various models, mostly two-dimensional, of directed walks, interfaces, wetting, surface adsorption (of polymers), stacks, compact clusters (lattice animals), etc. The unifying feature of these models is that in most cases they can be solved analytically. The methods used include transfer matrices, generating functions, recurrence relations, and difference equations, and in some cases involve utilization of less familiar mathematical techniques such as continued fractions and q-series. The authors emphasize an overall view of what can be learned generally of the statistical mechanics of anisotropic systems, including phenomena near surfaces, by studying the solvable models. Thus, the concept of scaling and, where known, finite-size scaling properties are elucidated. Scaling and statistical mechanics of anisoptropic systems in general are active research topics. The volume provides a comprehensive survey of exact model results in this field.

The Second International Conference on Nuclidic Masses was held in Vienna, Austria, July 15-19, 1963, using facilities of the International Atomic Energy Agency. This was the third conference in the general area of nuclidic masses in recent years. The first, a symposium held at the Max Planck Institut fur Chemie in 1956, was international in character but not in name. The First International Conference on Nuclidic Masses was held at McMaster University in September of 1960 in conjunction with and shortly after the meeting of the General Assembly of the International Union of Pure and Applied Physics and the Kingston Conference on Nuclear Structure. The Second International Conference on Nuclidic Masses was held under the sponsorship of the International Union of Pure and Applied Physics and the Nuclear Science Committee of the National Academy of Sciences-National Research Council of the United States. Financial support for the conference came from the United Nations Educational, Scientific, and Cultural Organization. The conference committee was made up of the following individuals: Chairman: J. H. E. MATTAUCH General Secretary: H. E. DUCKWORTH Local Secretary: F. P. VIEHBOCK w. W. BUECHNER B. GROSS E. R. COHEN M. J. HIGATSBERGER A. DE SHALIT A. O. C. NIER J. W. M. DuMoND H. H. STAUB B. S. DZHELEPOV D. M. VAN PATTER A. H.

The contributors to this volume study macroscopic flow properties and molecular mobility in complex liquids with high internal mobility and a highly anisotropic molecular shape. Particular attention is paid to the wide variety of experimental approaches, in theory as well as in computer simulation of these difficult but very important problems. The contributions are of interest to researchers in physics as well as in engineering and chemistry.

High-energy ion-atom collisions are subject of intense investigation in present-day atomic physics. They give fundamental information on the collision mechanism of ions and atoms, and on their highly excited states. This book includes invited survey talks, and invited contributions, all carefully refereed. The topics covered are electron capture and loss (including ionization), double electron and resonance processes, electron correlation and post-collision interaction effects, collisions of antiparticles with atoms, and so forth.

This outstanding collection of surveys addresses graduate and predoctoral students. It reports on theoretical research and observational data on active galactic nuclei: The enigma of the nuclei of galaxies with their central "monster" driving the vast range of activity observed in quasars, radio galaxies, Seyferts, starburst galaxies and even our own Galaxy are explored in this volume. Topics covered include: the impact of recent measurements in the infrared and radio region on our knowledge of thenucleus of our Galaxy; the spectra and classification of active galactic nuclei, the properties of their host galaxies, their cosmological distribution and evolution, the role of stars and thehydrodynamics of the interstellar medium in the nuclei; the description of the inner parsec of a standard active galactic nucleus based on direct interpretation of the observations; the infrared activity of galaxies; the physics of radio galaxies and their jets, emphasizing the physics ofgas flow and high-energy particle interactions as well as shock acceleration. These are all discussed in considerable depth and presented inself-contained chapters with exhaustive reference lists of the scientific literature.

This monograph teaches advanced undergraduate students and practitioners how to use folded diagrams to calculate properties of complex particle systems such as atomic nuclei, atoms and molecules in terms of interactions among their constituents. Emphasis is on systems with valence particles in open shells. Detailed diagram rules are derived and illustrated by simple examples. Applications include nuclear optical model potentials, meson-exchange theory of the nucleon-nucleon interactions and molecular-structure problems.

Scattering theory is of interest to physicists and to chemists and has a wide variety of applications, but it also presents a considerable challenge to mathematicians, including numerical analysts. Within the Schroedinger picture in this volume are collected the various theoretical and mathematical treatments of scattering together with a host of reviews of its applications to atomic and nuclear physics, to surface physics and chemistry, for example trapping of atoms on surfaces, and to amorphous condensed systems. The reviews give a concise and pedagogically useful presentation of the state of the art, and may serve as introductions for newcomers, in particular for graduate students.

This book is devoted to the applications of the mathematical theory of solitons to physics, statistical mechanics, and molecular biology. It contains contributions on the signature and spectrum of solitons, nonlinear excitations in prebiological systems, experimental and theoretical studies on chains of hydrogen-bonded molecules, nonlinear phenomena in solid-state physics, including charge density waves, nonlinear wave propagation, defects, gap solitons, and Josephson junctions. The content is interdisciplinary in nature and displays the new trends in nonlinear physics.

Distinguished authors discuss topics in physical oceano- graphy, transonic aerodynamics, dynamics of vorticity, numerical simulation of turbulent flows, astrophysical jets, strange attractors, human-powered flight, and thefluid mechanics of the Old Faithful geyser and of the Mount St. Helens eruption of 1980. The authors deal with specific problems, but the emphasis is usually on the way that re- search is carried out at the edge of understanding, and often on the role of new techniques, instruments, and re- search strategies.

Superfluidity and closely related to it, superconductivity are very general phenomena that can occur on vastly different energy scales. Their underlying theoretical mechanism of spontaneous symmetry breaking is even more general and applies to a multitude of physical systems.

In these lecture notes, a pedagogical introduction to the field-theory approach to superfluidity is presented. The connection to more traditional approaches, often formulated in a different language, is carefully explained in order to provide a consistent picture that is useful for students and researchers in all fields of physics.

After introducing the basic concepts, such as the two-fluid model and the Goldstone mode, selected topics of current research are addressed, such as the BCS-BEC crossover and Cooper pairing with mismatched Fermi momenta."

Ouverts a I'ensemble de la communaute internationale, les symposia ASTM-EURATOM sur la dosimetrie des rayonnements de reilcteur traitent de tous les sujets de dosimetrie dans tous les systemes a neutron: dosimetrie des experiences en reacteur, codes d'ajustement, precision, etalons et intercomparaison, donnees nucleaires, techniques de mesure, correlation de dommages radio-induits, echauffement nucleaire, etc ...appliques principalement aujourd'hui aux problemes des reacteurs a eau legere, des reacteurs a neutrons rapides et aux systemes a fusion. Les travaux en dosimetrie, tout comme I'ensemble du domaine de I'energie atomique, sont moins caracterises aujourd'hui par des idees scientifiques franchement nouvelles que par la necessite d'echange, de cooperation, de collaboration, appliques a la satisfaction de besoins de type industriel ou quasi-industriel. L'organisation de nos symposia a suivi cette evolution.Nombre de ceux qui y ont participe ont un souvenir emu du ler symposium a Petten en 1975, qui fut une reussite complete.L'organisation et Ie devouement du CCR de Petten y avait beaucoup contribue. Et puis, aussi, c'etait un commencement, c'etait Ie premier de nos symposia ...Les symposia suivants, alternativement aux USA et en EUROPE, a rythme sensiblement bi-annuel, ont du faire face progressivement a un besoin plus grand d'echange et de discussion par petits groupes, ainsi qu'a afflux croissant de propositions de communications de valeur. L'organisation a du s'adapter en consequence. Ce 5eme sy~posium ASTM- EURATOM represente, de part sa belle reussite, une etape importante de cette evolution et un garant de la maturation correspondante.

This thesis unifies the dissipative dynamics of an atom, particle or structure within an optical field that is influenced by the position of the atom, particle or structure itself. This allows the identification and exploration of the fundamental 'mirror-mediated' mechanisms of cavity-mediated cooling leading to the proposal of a range of new techniques based upon the same underlying principles. It also reveals powerful mechanisms for the enhancement of the radiation force cooling of micromechanical systems, using both active gain and the resonance of a cavity to which the cooled species are external. This work has implications for the cooling not only of weakly-scattering individual atoms, ions and molecules, but also for highly reflective optomechanical structures ranging from nanometre-scale cantilevers to the metre-sized mirrors of massive interferometers.

Atomic cluster physics has evolved into a research field of truly interdisciplinary character. In particular, it has become apparent that phenomena in atomic nuclei have many analogues in atomic clusters. Increasing the interaction between nuclear and cluster physics can thereforeact as stimulus for both communities. The volume contains the Proceedings of a WE-Heraeus workshop on "Nuclear Physics Concepts inAtomic Cluster Physics" held in Bad Honnef (Germany), November 26-29, 1991. Both theoretical and experimental methods and results are discussed in detail, thus providing the first systematic account of the intimate connections between both fields.

An international group of outstanding scientists presents a balanced discussion of various controversies in current turbulence theory. Six topics from the present-day approach to turbulence are each introduced by a survey, followed by three commentaries and a panel discussion. This analysis evaluates future developments of theories presently used for understanding and modelling turbulent flows.

Computational Atomic Physics deals with computational methods for calculating electron (and positron) scattering from atoms and ions, including elastic scattering, excitation, and ionization processes. Each chapter is divided into abstract, theory, computer program with sample input and output, summary, suggested problems, and references. An MS-DOS diskette is included, which holds 11 programs covering the features of each chapter and therefore contributing to a deeper understanding of the field. Thus the book provides a unique practical application of advanced quantum mechanics.

"New physics" is an appealing new keyword, not yet devalued by the ravages of inflation. But what has this to do with such an ugly field as plasma physics, steeped in classical physics, mostly outworn, with all its unsolved and ambiguous technological problems and its messy and open ended numerical studies? "New physics" is concerned with quarks, Higgs particles, grand unified theory, super strings, gravitational waves, and the profound basics of cosmology and black holes. It is the field of astonishing quantum effects, demonstrated by the von Klitzing effect and high temperature superconductors. But what can plasma physicists offer, after so many years of expensive and frustrating research to solve the problem of fusion energy? One may suggest that the fascinating research ofchaos with applications to plasma, or the achievements of statistical mechanics applied to plasmas, has something to offer and should be the subject of attention. However, this is not the aim of this book. Complementing the traditional aim of physics, which is to interpret the phenomena of nature by generalizing laws such that exact predictions about new properties and effects can be drawn, this book demonstrates how new physics has been derived over the last 30 years from the state of matter which exists at high temperatures (plasma).

Nuclear reactions at energies near and below the Coulomb barrier have found much interest since unexpectedly large cross sections of fusion for heavy ions were discovered around 1980. This book covers the more important experimental and theoretical aspects such as sub-barrier fusion, sub- and near-barrier transfer, couplings of various reaction channels, neck-formation, the threshold anomaly, spin distributions and fusion of polarized ions. The symposium also included a session devoted to mass spectrometry for fast reaction products.

This is a comprehensive overview of the information yielded by electroweak probes about the nuclear- and subnuclear-scale structure of matter. Lepton-induced processes from low energy through to the highest energies are considered. The first three lectures review electromagneticprocesses in hadrons; others cover the properties of partons, the behaviour of the constituents of the hadron, muon and neutrino scattering etc. An introduction to electroweak theory including the status of precision tests and data analyses is given along with a report on the first results from HERA. The lecturers have endeavoured to achieve a balance between scientific and didactic aspects thus making the book accessible also to students of nuclear and particle physics.

Semiclassical Theory of Atoms presents a novel approach to theoretical atomic physics. The fundamental quantity in this new, powerful formalism is the effective potential, not the density. The starting point is the highly semiclassical approximation known as the Thomas-Fermi model. It is studied in great detail, and then refined in three steps by adding quantum corrections successively according to their importance. First, the strongly bound electrons are treated in detail. Second, the bulk of electrons is better described by introducing quantum corrections to the Thomas-Fermi treatment and by including the exchange interaction. At this stage, predicted binding energies, for instance, are correct to within a small fraction of a percent. Third, shell effects are introduced. The improved semiclassical treatment is then sufficiently refined to reproduce the systematics of the Periodic Table. It addresses the graduate student with a good knowledge of elementary quantum mechanics.

The present book provides an introduction to quantum optics, the study of optical effects that cannot be explained by classical theory. Its main concern is the theoretical background to the key experiments in quantum optics. More than half of the material in this third edition is new, the material that has appeared in the previous editions already has been updated. The level of the treatment as a whole is appropriate for postgraduate students and research workers, while earlier chapters are also suitable for final-year undergraduates.

This brief investigates the diradical character, which is one of the ground-state chemical indices for "bond weakness" or "electron correlation" and which allows researchers to explore the origins of the electron-correlation-driven physico-chemical phenomena concerned with electronic, optical and magnetic properties as well as to control them in the broad fields of physics and chemistry. It then provides the theoretical fundamentals of ground and excited electronic structures of symmetric and asymmetric open-shell molecular systems by using model molecular systems. Moreover, it presents the theoretical design guidelines for a new class of open-shell singlet molecular systems for nonlinear optics (NLO) and singlet fission.

Ultra-cold atomic ensembles have emerged in recent years as a powerful tool in many-body physics research, quantum information science and metrology. This thesis presents an experimental and theoretical study of the coherent properties of trapped atomic ensembles at high densities, which are essential to many of the aforementioned applications. The study focuses on how inter-particle interactions modify the ensemble coherence dynamics, and whether it is possible to extend the coherence time by means of external control. The thesis presents a theoretical model which explains the effect of elastic collision of the coherence dynamics and then reports on experiments which test this model successfully in the lab. Furthermore, the work includes the first implementation of dynamical decoupling with ultra-cold atomic ensembles. It is demonstrated experimentally that by using dynamical decoupling the coherence time can be extended 20-fold. This has a great potential to increase the usefulness of these ensembles for quantum computation.

The optical trapping of colloidal matter is an unequalled field of technology for enabling precise handling of particles on microscopic scales, solely by the force of light. Although the basic concept of optical tweezers, which are based on a single laser beam, has matured and found a vast number of exciting applications, in particular in the life sciences, there are strong demands for more sophisticated approaches. This thesis gives an introductory overview of existing optical micromanipulation techniques and reviews the state-of-the-art of the emerging field of structured light fields and their applications in optical trapping, micromanipulation, and organisation. The author presents established, and introduces novel concepts for the holographic and non-holographic shaping of a light field. A special emphasis of the work is the demonstration of advanced applications of the thus created structured light fields in optical micromanipulation, utilising various geometries and unconventional light propagation properties. While most of the concepts developed are demonstrated with artificial microscopic reference particles, the work concludes with a comprehensive demonstration of optical control and alignment of bacterial cells, and hierarchical supramolecular organisation utilising dedicated nanocontainer particles.

Dispersion forces acting on both atoms and bodies play a key role in modern nanotechnology. As demonstrated in this book, macroscopic quantum electrodynamics provides a powerful method for understanding and quantifying dispersion forces in a vast range of realistic scenarios. The basic physical concepts and theoretical steps allow for the derivation of outlined general expressions for dispersion forces. As illustrated by a number of examples, these expressions can easily be used to study forces between objects of various shapes and materials, including effects like material absorption, nontrivial magnetic properties and dynamical forces asssociated with excited systems.