* At the present stage of development of surface science, there has seemed to be a need for a book-length review spanning the disciplines of surface physics and surface chemistry-a review to summarize and show the con nection between the observations from each discipline. The various results and theories, derived on the one hand from studies of the physical, electronic, and optical properties of surfaces and on the other hand from studies of the chemical activity of surfaces, supplement each other in the search for a realistic model of the surface. The improved understanding possible with such an interdisciplinary approach has been confirmed by recent develop ments which cannot be classified as either surface chemistry or surface physics. Specifically, recent new experimental techniques and quantum mechanical models have provided a much more accurate picture of the nature of the electronic energy levels (bonding orbitals) present at a solid surface. With this more accurate picture we are now able to reconcile the various chemical and physical models that appeared in the early literature on surfaces. The objective of this work has therefore been to describe the results and current models of surface science spanning a broad gray area between surface physics and surface chemistry with some overlap into each of these disciplines. Relevant aspects of surface chemistry are discussed; we cover chemical interactions where bonding and electronic properties dominate, but stop short of specialized topics such as surfactants or liquid/liquid interfaces."

Early in 1989, while most of us were gathered in the Mediterranean five-centuries-old city of Alacant, the idea of a school on stopping and particle penetration phenomena came to our minds. Later that year when discussing this plan with some of the participants in the 13th International Conference on Atomic Collisions in Solids in Aarhus, we were pleased to note that the proposal was warmly welcomed indeed by the community. An Advanced Study Institute on this or a related subject had not been organized in the last decade. Because of the progress made particularly in the interaction of high energy beams with matter, and the many applications which the general subject of the stopping of charged particles (ions and electrons) in matter enjoys, a Study Institute appeared a worthy enterprise. Even though several international conference series cover developments in these areas, they miss tutorial introductions to the field. The title chosen was Interaction of Charged Particles with Solids and Surfaces, and the objectives were stated as follows: "to cover theory and experiments, including selected applications and hot topics, of the stopping of charged particles (ions and electrons) in matter. The emphasis will be on outlining the areas where further effort is needed, and on specifying the basic needs in applications. Fundamental concepts will prevail over applications, and the character of the Institute as a school will be stressed. " The school was directed by Fernando Flores (Spain), Herbert M. Urbassek (Germany), Nestor R.

Each summer, the Theoretical Physics Division of the Canadian Association of Physicists organizes a summer institute of two weeks duration on a current topic in theoretical physics. This volume contains the lectures from the Pacific Summer Institute held at Pearson College on Vancouver Island, B. C. (Canada) from August 23 to September 3, 1982. The Institute was titled "Progress in Nuclear Dynamics: Short-Distance Behavior in the Nucleus." The primary source of funds for the Institute came from NATO through its Advanced Study Institute programme. Significant finan cial support is also gratefully acknowledged from TRIUMF, Simon Fraser University, Natural Sciences and Engineering Research Council of Canada, and Atomic Energy of Canada Ltd. The topic of the school was the role of the substructure of hadrons--quarks and gluons--in nuclear physics. This includes not only the effects which may be observed in specific nuclear states, such as form factors at large momentum transfer, or the presence of hidden color components in the ground states of few nucleon systems, but also effects which may be observed in the nuclear matter contin uum: the phase transition from normal nuclear matter to a plasma of quarks and gluons. The current status of the long distance phenom enology of the nucleus--the interacting boson approximation and the role of n's and 's in nuclear structure, is also reviewed."

This volume is an exercises and solutions manual that complements the book "Particles and Fundamental Interactions" by Sylvie Braibant, Giorgio Giacomelli, and Maurizio Spurio. It aims to give additional intellectual stimulation for students in experimental particle physics. It will be a helpful companion in the preparation of a written examination, but also it provides a means to gaining a deeper understanding of high energy physics. The problems proposed are sometimes true and important research questions, which are described and solved in a step-by-step manner. In addition to the problems and solutions, this book offers fifteen Supplements that give further insight into topical subjects related to particle accelerators, signal and data acquisition systems and computational methods to treat them.

This volume consists of twelve review articles and a variety of short contributions which are based on lectures presented at the International Symposium on Photopion Nuclear Physics. The review articles were submitted after the sym posium, and there was considerable editing and cross referen cing with the aim of achieving a greater overall unity than ordinarily found in conference proceedings. Photopion Nuclear Physics, as the name suggests, combines two of the most active areas of current intermediate energy nuclear physics research - electromagnetic phenomena as studied by means of electron scattering and photonuclear pro cesses, and mesonic effects in nuclei. The potential value of photopion studies as a complement to electron scattering for the study of spin-isospin aspects of nuclear transitions has been widely recognized for about a decade, thanks to the the oretical work at such institutions as Stanford and Catholic Universities. In fact, some of this theoretical work was done in anticipation of the advent of the new high duty cycle and good energy resolution electron linacs. The potential for using this reaction to study mesonic effects was not as broad ly addressed at that time. However, as seen in the following pages of these proceedings, that situation has dramatically changed."

x the early stages, to the Programme Committee for their assistance in formulating the programme and for their continued support throughout, to the session chairmen and scientific secretaries, who ensured the smooth running of the proceedings, and to all the delegates, who, by their full participation and lively discussions have demonstrated the continuing vigour of this field of physics. We also gratefully acknowledge the sponsorship of the Institute of Physics, the British Council and IUPAP, and thank the Royal Society for additional financial support. Our thanks also are due to Chester College for their hospitality, to SERC Daresbury Laboratory for organi- zational support and for providing the conference staff at Chester. Finally, we owe a particular debt of gratitude to Mrs. Shirley Lowndes and Mrs. Christine Lloyd (Jackson) for their continuous and efficient work as mainstays of the conference organization. J.S. Lilley and M.A. Nagarajan International Scientific Advisory Committee A. Arima 11.V. !!ihailovic Brink V.G. Neuclatchin D.lI. D.A. Bromley J.O. Newton A. Dudzanowski D. Robson E.G. Giraud II. Tanaka 11. Harvey Y.C. Tang H.D. Holmgren A. Van der \loude D.F. Jackson \J.T. n. van Oers B.K. Jain A. IJeiguny Kin?, Sing Nan K. lJildermuth P. Krager Programme Committee D.lI. Brink G.C. Horrison L.L. Green 11. A. Nagarajan D.F. IJ. R.

The study of molecular collisions at energies from less than about 100 eV 3 down to a few 10- eV, which is roughly the range of chemical interest, has greatly expanded in the last 10 to 20 years. As in many fields, this activity has been stimulated by parallel advances in theory which have triggered the autocatalytic positive feedback system of experiment challenging theory and vice versa. Possibly the biggest driving force, however, has been the growing awareness that molecular collisions are important in our understanding of na tural and man-made environments. Molecular collision dynamics is now studied in connection with molecular formation in interplanetary space, upper atmo sphere chemistry, plasmas, lasers and fusion reactors, and is crucial for understanding gas-dynamic flow processes, gas-phase chemical reactions and catalysis. Despite the great strides made in studying elementary collisions in laboratory scattering experiments, many of the processes in these areas are too complicated for us to hope ever to study them in detail in the labo ratory. Thus in the long run we shall have to rely on theory. Initially, I think many of us, like myself, had hoped that the development of fast compu ters would outpace the demands on computing time so that "brute force" quan tum-mechanical exact calculations would provide all the answers. Unfortunate ly this has not been the case and efficient approximations are needed. They can be broadly classified as classical, semiclassical or semiquantal."

This NATO Advanced Study Institute centered on large-scale molecular systems: Quantum mechanics, although providing a general framework for the description of matter, is not easily applicable to many concrete systems of interest; classical statistical methods, on the other hand, allow only a partial picture of the behaviour of large systems. The aim of the ASI was to present both aspects of the subject matter and to foster interaction between the scientists working in these important areas of theoretical physics and theoretical chemistry. The quantum-mechanical part was mostly based on the operator-algebraic formulation of quantum mechanics and comprised quantum statistics of infinite systems with special em phasis on macroscopic observables, equilibrium conditions, irreversibility on the one hand, symmetry breaking for molecules in the radiation field and macroscopic quantum phenomena in the theory of superconductivity (BCS-theory) on the other hand. In addition, phase-space methods for many-body systems were also presented. Statistical physics was the main topic in the other lectures of the School; much emphasis was put on the statistical features of macros copic ("large") systems, the lectures dealt with mass and energy transport im polymers, in gels and in microemulsions, with aggregation and growth phenomena, with relaxation in complex, correlated systems, with conduction and optical properties of polymers, and with the means of describing disordered systems, above all fractals and related hierarchical models.

The monograph is devoted to phenomena of nonlinear optics appearing on a macro scopic level in the interaction of intense light with an isolated atom. It is a first attempt to summarize the elementary phenomena of nonlinear optics and present the various methods used in experiment and theory. In essence, this book can be considered an expanded version of the new aspect of quantum mechanics and atomic physics that in time will be incorporated into te- books on this subject. By the middle of this century the interaction of light with atoms had become one of the most investigated branches of physics. However, in the mid-sixties the development of high-power lasers changed this situation completely. It is a well-known fact that lasers are essentially new sources of light with high intensity, sharp directivity, and practically ideal monochromaticity. Entirely new phenomena came up in the studies of the interaction of light with atoms. In an intense light field, multiphoton transitions become important. The field disturbs the atomic levels, shifting, broadening, and mixing them. In an extremely strong field the atom ceases to be a bound system. These and similar phenomena on the atomic (microscopic) level determine the variations in the averaged, macroscopic properties of the medium, variations that cause nonlinear-optics phenomena, which radically change the fundamental classical laws of the interaction of light with matter."

Low-temperature spectroscopy of organic molecular crystals came into being in the late 20s, just when quantum physics of solids as a whole began to de velop vigorously. Already in the early works, two experimental facts of prime importance were discovered: the presence of a multitude of narrow bands in the low-temperature spectrum of a crystal, and a close relationship between the spectrum of the crystal and that of the constituent molecules. These findings immediately preceded the celebrated paper of Frenkel in which he went beyond the framework of Bloch's scheme and advanced the exciton concept. Subsequent investigations showed that the most interesting features of the spectra of molecular crystals are associated with excitons, and then the spectroscopy of molecular excitons began to form gradually on the basis of the spectroscopy of organic crystals. The molecular exciton became synonymous to the Frenkel exciton in a molecular crystal. In view of the difficulties involved in the analysis of rich spectra con taining many tens of bands, the spectroscopy of molecular crystals had long been connected most closely with the spectroscopy of molecules. It had deve loped independently, to a large extent, from the other branches of solid state physics. This was also emphasized by the difference in experimental techniques, the specific properties of the objects, etc. As a result, there was some lag in ideas and concepts."

There are both a remote and a proximate history in the development of this book. We would like to acknowledge first the perceptiveness of the technical administrators at RCA Laboratories, Inc. during the 1970s, and in particular Dr. P. N. Yocom. Buoyed up by the financial importance of yttrium oxysulfide: europium as the red phosphor of color television tubes, they allowed us almost a decade of close cooperation aimed at understanding the performance of this phosphor. It is significant that we shared an approach to research in an industrial laboratory which allowed us to avoid the lure of "first-principles" approaches (which would have been severely premature) and freed us to formulate and to study the important issues directly. We searched for a semiquantitative understanding of the properties observed in luminescence, i. e., where energy absorption occurs, where emission occurs, and with what efficiency this conversion process takes place. We were aware that the nonradi ative transition rates found in practice vary enormously with temperature and, for a given activator, with small changes in its environment. We traced the source of this enormous variation to the magnitude of the vibrational overlap integrals, which have strong dependences on the rearrangements occurring during optical transitions and on the vibrational number of the initial electronic state. We were willing to excise from the problem the electronic aspects - the electronic wavefunctions' and their transition integrals -by treating them as parameters to be obtained from the experimental data."

A lively demonstration of the great vitality and the multidisciplinary character of cluster research and of the usefulness of synthesizing its various aspects was given at this symposium. This volume covers all aspects of the physical and chemical properties of free and supported clusters or small particles: static, dynamical, electronic, magnetic and optical properties, adsorption and chemical phenomena. It thus gives a complete overview of the status of the field and its development.

Lawrence Freedman One of the major bonuses of the collapse of communism in Europe is that it may never again be necessary to enter into a sterile debate about whether it is better to be "red" or "dead." This appeared as the ultimate question in the great nuclear debate of the early 1980s. When put so starkly the answer appeared obvious better to live and struggle in a totalitarian system than to destroy totalitarian and democratic systems alike. There were a number of points to be made against this. Communist regimes had demonstrated the possibility of being both red and dead while the West had managed successfully to avoid the choice. If we allowed nuclear disarmament to become an overriding priority, this might encourage excessive respect for Soviet interests and a desire to avoid any sort of provocation to Moscow, a point not lost on those in Eastern Europe who were then struggling against repression and could not see why disarmament should be given a higher priority than freedom. Now that the old communist states have liberated themselves and the West no longer risks conspiring in their enslavement, there is a correspondingly re duced danger of mass death. As a result, and with so much else of immediate Lawrence Freedman * Department of War Studies, King's College, University of London, London WC2R 2LS, England. Nuclear Weapons in the Changing World: Perspectives from Europe, Asia, and North America.

Low dimensionality is a multifarious concept which applies to very diversified materials. Thus, examples of low-dimensional systems are structures with one or several layers, single lines or patterns of lines, and small clusters isolated or dispersed in solid systems. Such low dimensional features can be produced in a wide variety of materials systems with a broad spectrum of scientific and practical interests. These features, in turn, induce specific properties and, particularly, specific transport properties. In the case of zeolites, low dimensionality appears in the network of small-diameter pores of molecular size, extending in one, two or three di mensions, that these solids exhibit as a characteristic feature and which explains the term of "molecular sieves" currently used to name these ma terials. Indeed, a large number of industrial processes for separation of gases and liquids, and for catalysis are based upon the use of this low dimensional feature in zeolites. For instance, zeolites constitute the first class of catalysts employed allover the world. Because of the peculiarity and flexibility of their structure (and composition), zeolites can be adapted to suit many specific and diversified applications. For this reason, zeolites are presently the object of a large and fast-growing interest among chemists and chemical engineers.

Coherent sources in the short wavelength region are developing rapidly. They are expected to find many applications in the areas of atomic physics, photochemistry, photobiology, spectroscopy, microprocessing and microelectronics. The contributions to this book describe recent progress in this field, including new results on X-ray lasers and scaling to shorter wavelengths, free electron lasers using storage rings and induction linacs, excimer lasers, laser fusion research using short wavelength lasers, and applications to X-ray holography, X-ray lithography, and photochemistry. The papers discuss problems that have yet to be solved (modeling of the atomic process for X-ray emission is not yet accurate enough; damage of mirrors and optical elements in free electron and excimer lasers; achieving pulse compression in excimer lasers) but also report on the status of existing and planned installations for free electron lasers, laser fusion research, and excimer lasers.

The broad scope of the Applications of the Moessbauer Effect to interdisciplinary subjects makes this volume an outstanding source of information to researchers and graduate students, who will find the unique results of Moessbauer spectroscopy a valuable aid and complement to their research in conjunction with other techniques. In this volume, applications to mineralogy, catalysis, soil science, amorphous materials, nanoparticles, magnetic materials, nanotechnology, metallurgy, corrosion, and magnetism, have been put together in original works produced by invited speakers and different research teams across the continent. Reprint from Hyperfine Interactions (HYPE), volumes 202/1-3 and 203/1-3, 2011.

This volume contains the Proceedings of the "XXIV. Inter nationale Universitatswochen fur Kernphysik" held in Schlad ming, Austria, in February 1985. It consists of the written versions of the lectures (3-4 hours) given at this winter school and includes also most of the seminars (30-50 minutes) presented. In choosing the topic for the 1985 meeting, our aim was to give an account of the present understanding of the nucleon-nucleon as well as nucleon-antinucleon inter actions. This field, which is of definite relevance in nuclear and particle physics, has witnessed a rapid develop ment in recent times both in theory and experiment. New evidence has emerged in the whole range from low to extremely high energies. It was an exciting experience to bring to gether knowledge from the very domains of nuclear and high energy physics as well as to meet the respective researchers. Thanks to the efforts of the lecturers, who did a splendid job in presenting the lectures and in preparing their lecture notes, a comprehensive insight into the hadronic interaction between nucleons and anti-nucleons was achieved. The lecture notes were reconsidered by the authors after the meeting and are now being published in their final form. The seminars mainly dealt with specific topics currently under investiga tion within this rather wide field. We are grateful to all authors for their efforts, as they made it possible to speed up the publication of these proceedings."

This book brings together various aspects of the nuclear fission phenomenon discovered by Hahn, Strassmann and Meitner almost 70 years ago. Beginning with an historical introduction the authors present various models to describe the fission process of hot nuclei as well as the spontaneous fission of cold nuclei and their isomers. The role of transport coefficients, like inertia and friction in fission dynamics is discussed. The effect of the nuclear shell structure on the fission probability and the mass and kinetic energy distributions of the fission fragments is presented. The fusion-fission process leading to the synthesis of new isotopes including super-heavy elements is described. The book will thus be useful for theoretical and experimental physicists, as well as for graduate and PhD students.

The understanding in science implies insights from several different points of view. Alternative modern outlooks on electronic structure of atoms and molecules, all rooted in quantum mechanics, are presented in a single text. Together these complementary perspectives provide a deeper understanding of the localization of electrons and bonds, the origins of chemical interaction and reactivity behavior, the interaction between the geometric and electronic structure of molecules, etc. In the opening two parts the basic principles and techniques of the contemporary computational and conceptual quantum chemistry are presented, within both the wave-function and electron-density theories. This background material is followed by a discussion of chemical concepts, including stages of the bond-formation processes, chemical valence and bond-multiplicity indices, the hardness/softness descriptors of molecules and reactants, and general chemical reactivity/stability principles. The insights from Information Theory, the basic elements of which are briefly introduced, including the entropic origins and Orbital Communication Theory of the chemical bond, are the subject of Part IV. The importance of the non-additive (interference) information tools in exploring patterns of chemical bonds and their covalent and ionic components will be emphasized.

This book is based on the course in theoretical nuclear physics that has been given by the author for some years at the T. G. Shevchenko Kiev State University. This version is supplemented and revised to include new results obtained after 1971 and 1975 when the first and second editions were published. This text is intended as an introduction to the nonrelativistic theory of po tential scattering. The analysis is based on the scattering matrix concept where the relationship between the scattering matrix and observable physical quantities is considered. The stationary formulation of the scattering problem is presented; particle wave functions in the external field are obtained. A formulation of the optical theorem is given as well as a discussion on time inversion and the reci procity theorem. Analytic properties of the scattering matrix, dispersion relations, and complex moments are analyzed. The dispersion relations for an arbitrary di rection scattering amplitude are proven, and analytic properties of the amplitude in the plane of the complex cosine of the scattering angle are studied in detail."

The methods of statistical physics have become increasingly important in recent years for the treatment of a variety of diverse physical problems. Of principal interest is the microscopic description of the dynamics of dissipative systems. Although a unified theoretical description has at present not yet been achieved, we have assumed the task of writing a textbook which summarizes those of the most important methods which are self-contained and complete in themselves. We cannot, of course, claim to have treated the field exhaustively. A microscopic description of physical phenomena must necessarily be based upon quantum theory, and we have therefore carried out the treatment of dynamic processes strictly within a quantum-theoretical framework. For this reason alone it was necessary to omit a number of extremely important theories which have up to now been formulated only in terms of classical statistics. The goal of this book is, on the one hand, to give an introduction to the general principles of the quantum statistics of dynamical processes, and, on the other, to provide readers who are interested in the treatment of particular phenomena with methods for solving specific problems. The theory is for the most part formulated within the calculational frame work of Liouville space, which, together with projector formalism, has become an expedient mathematical tool in statistical physics."