This book gives a representative survey of the state of the art of research on gas-surface interactions. It provides an overview of the current understanding of gas surface dynamics and, in particular, of the reactive and non-reactive processes of atoms and small molecules at surfaces. Leading scientists in the field, both from the theoretical and the experimental sides, write in this book about their most recent advances. Surface science grew as an interdisciplinary research area over the last decades, mostly because of new experimental technologies (ultra-high vacuum, for instance), as well as because of a novel paradigm, the 'surface science' approach. The book describes the second transformation which is now taking place pushed by the availability of powerful quantum-mechanical theoretical methods implemented numerically. In the book, experiment and theory progress hand in hand with an unprecedented degree of accuracy and control. The book presents how modern surface science targets the atomic-level understanding of physical and chemical processes at surfaces, with particular emphasis on dynamical aspects. This book is a reference in the field.

The editors have pleasure in presenting this volume of our review series. We have specialised in three areas: perturbation Monte Carlo, non-linear kinetics and the transfer of radioactive fluids in rocks. These contributions are linked, however, in the demands for optimising complex systems that are a feature of the scale of nuclear power production. Kuniharu Kishida's account of Japanese thinking in the application of modern non-linear theory to reactor kinetics and control comes at a time when the community of control scholars is seeking how to apply the new ideas that have led to the prominence of chaos theory to our field. Pr- lems of maintenance in power reactors are as severe as ever and must be solved for credibility to characterise any new program. As much as 30% of unanticipated down-time, for example, is due to the failure of motor op- ated valves. We need a theory to provide for preventive maintenance. This in turn depends heavily on on-line monitoring to anticipate failure as well as expert systems to schedule preventive treatment. Noise theory with its promise of on-line interpretation of information from inchoate breakdown is the key. It is all too likely that the need to deal with major departures makes a non-linear theory of noise essential. We can be grateful that P- fessor Kishida has provided us with such a consistent account.

Electron spin relaxation has established itself as an important experimental method for studying the details of molecular motion in liquids, and as a harsh testing ground for theoreticians. The theo retical difficulties are connected with the complexity of the mole cular motion, and the theoretical interest lies not only in its im portant consequences for the interpretation of experiments, but also in the fascination of a system in which a well-defined quantum me chanical component is in interaction with a complex quasi-classical environment. It is because the theories are concerned with such dissimilar but connected systems that the techniques involved are so numerous. Many of the standard manipulations of quantum mechanics must be brought to bear, and at the same time they must be combined with statistical techniques which are often of considerable sophis tication. The purpose of this volume is to present a survey of these techniques and their application to spin relaxation problems. No single volume can be exhaustive, but we believe that the contri butions to this volume are sufficiently broad to show how those who are concerned with spin relaxation problems think about the subject and circumvent, or expose, its difficulties. The first few Chapters (I-V) review the basic quantum mechani cal and statistical manipulations which are often used."

The Sixth International Conference on Atomic Masses was held in East Lansing, Michigan, Sept. 18-21, 1979. The conference was initiated, organized, and sponsored by the Commission on Atomic Masses and Fundamental Constants of the International Union of Pure and Applied Physics. The members of the conference committee are listed below: W. Benenson, Chairman Michigan State University R. C. Barber University of-Manitoba E. R. Cohen Rockwell International Institute of Chemical Physics, V. I. Goldanskii Moscow J. C. Hardy Chalk River, Canada W. H. Johnson University of Minnesota E. Kashy Michigan State University Orsay, France R. Klapisch J. A. Nolen, Jr. Michigan State University R. G. H. Robertson Michigan State University E. Roeckl G. S. I., Darmstadt B. N. Taylor National Bureau of Standards O. Schult IKF, Julich A. H. Wapstra IFO, Amsterdam N. Zeldes Racah Institute, Jerusalem The conference was a little different from the preceding one (in Paris, 1975) in that the fundamental constant aspects were limited to those directly related to atomic masses. The gap is to be filled by the second International Conference on Precision Measurement and Fundamental Constants which is now scheduled for June 1981 in Gaithersburg, Maryland. Only one of the seven sessions in this conference was devoted to fundamental constant determina tions. The conference was very strongly supported by the Department of Energy, the National Science Foundation, and the International Union of Pure and Applied Physics."

This volume is composed of papers (invited and contributed) presented at the International Conference on Coherence and Quantum Optics held at the University of Hyderabad January 5-January 10, 1991. It has been organized by Professor Girish Agarwal and his colleagues at the School of Physics, University of Hyderabad, Hyder abad, India under partial support from the Department of Science and Technology, Government of India, International Center for Theoretical Physics, Trieste, Italy and the National Science Foundation, USA. Without the untiring efforts of Prof. Girish Agarwal and the members of his quantum office group, the Conference and the present volume would not have been possible. Some extraordinary circumstances resulted in a delay of the publication of the present volume. Our sincere apologies to all the authors. We deeply regret the inconvenience caused due to the delay. A debt of gratitude is due to Ms. Kim Bella for the excellent typing job of the different versions and the final version of the manuscript. It is a pleasure to acknowl edge the efforts of Ms. Pat Vann, Mr. Greg Safford and Mr. Eric Katz of the Plenum Publishing, without whose interest and persistence this volume would not have been possible. v CONTENTS QUANTUM OPTICS: THEORY The Quantum Mechanics of Particles in Time-Dependent Quadrupole Fields Roy J. Glauber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Localization of Photons in Random and Quasiperiodic Media S. Dutta Gupta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Enhanced Fundamental Linewidth of a Laser Due to Outcoupling W. A. Hamel, M. P. van Exter, and J. P. Woerdman . . . . . . . . . . . . . . . . . . . . . . . ."

Dur previous volume 14 was devoted to an exposition of the topics of sensitivity analysis and uncertainty theory with its development and application in nuclear reactor physics at the heart of the discussion. In this volume, we return to our customary format as a selection of topics of current interest, authored by those working in the field. These topics range from the theoretical underpinnings of the (linear) Boltzmann transport equation to a resume of our ex pectations in what still may be thought of as twenty-first century technology, the world's fusion reactor program. In the first article of this volume, we have Protopop escu's analysis of the structure of the Boltzmann equation and its solutions for energy and space-dependent problems of an eigenvalue nature. There long has been a curious "folk history" effect in this area~ Wigner and Weinberg could de scribe it as "what was generally known was generally untrue". This account of the Boltzmann equation surely will show that a rigorous basis for our expectations of certain solutions can be well-founded on analysis. Ely Gelbard's review of the methods of determining diffusion-type parameters in complex geometries where simple diffusion theory would be welcome has required just as much rigor to determine how such modeling can be made accurate, although to a more immediate and practical purpose. The two articles can be seen as interesting contrasts, facets of the same underlying problem showing apparently different aspects of the same central core.

Atomic Physics 7 presents the manuscripts of the invited talks delivered at the Seventh International Conference of Atomic Physics, held at M.I.T. August 4-8, 1980. This conference continues the tradition of the earlier conferences by reviewing broad areas of fundamental atomic physics and related subjects. In addition to the invited talks, one hundred and ninety contributed papers were presented in poster sessions. Abstracts of the contributed papers have been printed separately in a small volume. Three hundred and fifty participants from thirteen nations attended the conference. One of the highlights of the conference was an historical talk by Professor Abraham Pais of Rockefeller University entitled "The Birth of the Quantum Theory: Planck." The manuscript of this talk will be published elsewhere. Dr. John Bailey presented a talk on the proton-antiproton system at low energy, but was unable to provide a manuscript for this volume. Also omitted from these Proceedings, but one of the highlights of the Conference, are the comments by Professor I. I. Rabi, an active participant who chaired one session and spent an evening discussing science, history and public policy with graduate students at the Conference.

The Workshop N* Physics and non-perturbative QeD was held at the Eu ropean Center for Theoretical Studies and Related Areas (ECT*) in Trento, Italy, during May 18-29, 1998. Previous workshops of the series on N* Physics took place at the Florida State University (1994), at CEBAF (1995), at the Institute for Nuclear Theory in Seattle (1996) and at the George Washington University (1997). The Workshop was devoted to a summary of recent experimental and the oretical research on N* phsyics and special emphasis was given to the infor mation that photo-and electro-production of nucleon resonances can provide on the non-perturbative regime of Quantum Chromodynamics. The idea was to stimulate discussions among experimentalists and theoreticians in order to pursue the interpretation of the huge amount of forthcoming data from several laboratories in the world. It was therefore decided to have both experimental and theoretical lectures on the main topics, like, among the others, single and double pion production, TJ-and K-meson production, the GDH sum rule, the spin of the proton, etc. Thanks to the unusual two-week extension of the Work shop, the allotted time for the lectures was extended up to one hour in order to allow the invited lecturers to give a detailed presentation of their topics. Fi nally, various short contributions were selected to sharpen the discussion about selected items."

As much by chance as by design, the present volume comes closer to having a single theme than any of our earlier volumes. That theme is the properties of nuclear strength functions or, alternatively, the problem of line spreading. The line spreading or strength function concepts are essential for the nucleus because of its many degrees of freedom. The description of the nucleus is approached by using model wave functions-for example, the shell model or the collective model-in which one has truncated the number of degrees of freedom. The question then is how closely do the model wave functions correspond to the actual nuclear wave functions which enjoy all the degrees of freedom of the nuclear Hamiltonian? More precisely, one views the model wave functions as vectors in a Hilbert space and one views the actual wave functions as vectors spanning another, larger Hilbert space. Then the question is: how is a single-model wave function (or vector) spread among the vectors corresponding to the actual wave functions? As an example we consider a model state which is a shell-model wave function with a single nucleon added to a closed shell. Such a model state is called a single-particle wave function. At the energy of the single-particle waVe function one of the actual nuclear wave functions may resemble the single-particle wave function closely.

This multidisciplinary book is intended to serve as a reference for postgraduate students and researchers working in the fields of charged particle optics or other finite-element-related applications. It is also suitable for use as a graduate text. For the non-specialist in charged particle optics, the opening chapters provide an introduction to the kinds of field problems that occur in charged particle beam systems. A new and comprehensive approach to the subject is taken. The finite element method is placed within a wider framework than strictly charged particle optics. Concepts developed in fluid flow and structural analysis, not hitherto used in charged particle optics, are presented. Benchmark test results provide a way of comparing the finite element method to other field-solving methods. The book also reports on some high-order interpolation techniques and mesh generation methods that will be of interest to other finite element researchers.Additional coverage includes: * field theory and field solutions for charged particle optics; * aspects of the finite difference method related to the finite element method; * finite element theory and procedure, including detailed formulation of local and global matrices; * higher-order elements, which can be an effective way of improving finite element accuracy; * the finite element method in three dimensions; * ways to formulate scalar and vector problems for magnetic fields; and * significant reduction of truncation errors using higher-order elements and extrapolation methods.

Most textbooks in the field are either too advanced for students or don t adequately cover current research topics. Bridging this gap, Electronic Structure of Materials helps advanced undergraduate and graduate students understand electronic structure methods and enables them to use these techniques in their work.

Developed from the author s lecture notes, this classroom-tested book takes a microscopic view of materials as composed of interacting electrons and nuclei. It explains all the properties of materials in terms of basic quantities of electrons and nuclei, such as electronic charge, mass, and atomic number. Based on quantum mechanics, this first-principles approach does not have any adjustable parameters.

The first half of the text presents the fundamentals and methods of electronic structure. Using numerous examples, the second half illustrates applications of the methods to various materials, including crystalline solids, disordered substitutional alloys, amorphous solids, nanoclusters, nanowires, graphene, topological insulators, battery materials, spintronic materials, and materials under extreme conditions.

Every chapter starts at a basic level and gradually moves to more complex topics, preparing students for more advanced work in the field. End-of-chapter exercises also help students get a sense of numbers and visualize the physical picture associated with the problem. Students are encouraged to practice with the electronic structure calculations via user-friendly software packages."

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 allowfor thederivation ofoutlined 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.

In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of different aspects and scenarios. Macroscopic quantum electrodynamics is applied within the context of dispersion forces. In contrast to the normal-mode quantum electrodynamics traditionally used to study dispersion forces, the new approach allows to consider realistic material properties including absorption and is flexible enough to be applied to a broad range of geometries. Thus general properties of dispersion forces like their non-additivity and the relation between microscopic and macroscopic dispersion forces are discussed. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. In particular, nontrivial magnetic properties of the bodies, bodies of irregular shapes, the role of material absorption, and dynamical forces for excited atoms are discussed. This volume 2 deals especially with quantum electrodynamics, dispersion forces, Casimir forces, asymptotic power laws, quantum friction and universal scaling laws. The book gives both the specialist and those new to the field a thorough overview over recent results in the context of dispersion forces. It provides a toolbox for studying dispersion forces in various contexts.

The Editors take pleasure in presenting Volume 13 of this annual review series, consisting, as usual, of author itative reviews of timely developments in the technical fields of nuclear engineering, science, and teechnology. No one in the community we try to serve in a post Harrisburg era will need convincing of the relevance of the first two items to be mentioned from the volume. Instru mentation for two-phase flow measurements, by Banerjee and Lahey, has applicability in the engineering research labor atory and to power reactors; the U. S. LWR still remains the dominant power reactor type and seems likely to retain its hold if only through the capital of existing plants this century. Messrs. Bohm, Closs, and Kuhn, however, have a longer time scale to respect as they view for us the prospects of nuclear waste disposal from a European viewpoint. They bring out nicely the political aspects that cannot be divorced from technical considerations in this area, or in the more militant terms of confrontation, in this arena, perhaps. We are pleased to carry in this volume two complemen tary papers on mathematical methods in nuclear engineering."

At a level accessible to advanced undergraduates, this textbook explains the fundamental role of quantum mechanics in determining the structure, dynamics, and other properties of molecules. Readers will come to understand the quantum-mechanical basis for harmonic oscillators, angular momenta and scattering processes. Exercises are provided to help readers deepen their grasp of the essential phenomena.

"Nuclear Electrodynamics" quantitatively describes both nuclear electromagnetic properties and processes of the electromagnetic interaction.The main emphasis is on the derivation of basic equations. The book is intended for both theorists and experimentalists specializing in this field. Contents: - Introduction - Electromagnetic Multipole Moments - Interaction Between Nuclei and Electromagnetic Radiation - Electron-Nucleus Interaction (Elastic and Inelastic Scattering) - Electron-Nucleus Interaction (Nuclear Electrodisintegration and Inclusive Processes) - Electromagnetic Interaction between Heavy Charged Particles and Nuclei - References - Subject Index

The present volume reaffirms nuclear physics as an experimental science since the authors are primarily experimentalists and since the treatment of the topics might be said to be "experimental." (This is no reflection on the theoretical competence of any of the authors.) The subject of high-spin phenomena in heavy nuclei has grown much beyond the idea of "backbending" which gave such an impetus to its study five years ago. It is a rich, new field to which Lieder and Ryde have contributed greatly. The article "Valence and Doorway Mechanisms in Resonance Neutron Capture" is, in contradistinction, an article pertaining to one of the oldest branches of nuclear physics-and it brings back one of our previous authors. The Doppler-shift method, reviewed by Alexander and Forster, is one of the important new experimental techniques that emerged in the previous decade. This review is intended, deliberately, to describe thoroughly a classic technique whose elegance epitomizes much of the fascination which nuclear physics techniques have held for a generation of scientists. This volume concludes the work on the Advances in Nuclear Physics series of one of the editors (M. Baranger), whose judgment and style characterize that which is best in the first ten volumes. Many of our readers and most of our authors will be grateful for the high standards which marked his contributions and which often elicited extra labor from the many authors of the series.

Research on photon and electron collisions with atomic and molecular targets and their ions has seen a rapid increase in interest, both experimentally and theoretically, in recent years. This is partly because these processes provide an ideal means of investigating the dynamics of many particle systems at a fundamental level and partly because their detailed understanding is required in many other fields, particularly astrophysics, plasma physics and controlled thermonuclear fusion, laser physics, atmospheric processes, isotope separation, radiation physics and chemistry and surface science. In recent years a number of important advances have been made, both on the experimental side and on the theoretical side. On the experimental side these include absolute measurements of cross sections, experiments using coincidence techniques, the use of polarised beams and targets, the development of very high energy resolution electron beams, the use of synchrotron radiation sources and ion storage rings, the study of laser assisted atomic collisions, the interaction of super-intense lasers with atoms and molecules and the increasing number of studies using positron beams.

In these days of specialization it is important to bring together physicists working in diverse areas to exchange and share their ideas and excitement. This leads to cross-fertilization of ideas, and it enriches, as in biological systems, a specialized field with new strength, development and direction derived from another area. Although this might be an uncommon thing, it is an important step in our under standing of the physical world around us, which is, after aIl, the main purpose of physics. The seed for this conference was really sowed when one of us (MB) and Mr. Manngard showed some a-scattering data at backward angles to FBM one summer about four years ago. That occasion led to a long research collaboration between the Abo Akademi physicists and other scientists in several countries. The actual idea to explore the possibility of holding a conference, however, crystallized in the summer of 1989 during a visit of FBM to Abo Akademi. The final decision to organize a conference was made after MB visited Profes sor Ben Mottelson in Copenhagen and Professor Anagnostatos in Athens. At this point it was recognized that there are similarities as weIl as differences between clustering phenomena in nuclei and systems consisting of atoms. It was therefore conjectured that it could be very stimulating to bring together these groups to exchange their ideas and to leam from each other's fields. A conference along these lines, we hoped, would contribute to an increased mutual understanding."

A "Festschrift" volume fulfils a more far-reaching purpose than the laudatory one. It shows how science develops as a result of the activities - scientific and organizational - of an individual person. Scientific achievement cannot be subjected to the very refined measurement techniques of science itself, but there is a continuous mutual evaluation among scientists which manifests itself through refereeing, literature citation and dedicatory volumes like the present one. Near and distant associates of Per-Olov Lowdin were enthusiastic about the idea of a tribute to him in the form of a collection of scientific papers on the occasion of his sixtieth birthday. Monographs and journals have fairly well-defined readerships. This book is directed to a wider group of scientists. It presents reviews of areas where Lowdin's work has influenced the development as well as research papers with original results. We feel that it can serve as a source on the current status of the quantum theory of matter for scientists in neighbouring fields. It might also provide stimulus for renewed scientific efforts among scientists turned administrators and will certainly be relevant for teachers and students of quantum theory.

The book is devoted to the modern theory and experimental manifestation of Polarization Bremsstrahlung (PB) which arises due to scattering of charged particles from various targets: atoms, nanostructures (including atomic clusters, nanoparticle in dielectric matrix, fullerens, graphene-like two-dimensional atomic structure) and in condensed matter (monocrystals, polycrystals, partially ordered crystals and amorphous matter) The present book addresses mainly researchers interested in the radiative processes during the interaction between fast particles and matter. It also will be useful for post-graduate students specializing in radiation physics and related fields.