This book has come into being as a result of scientific debates. And these debates have determined its structure. The first chapter is in the form of Socratic dialogues between a mathematician (MATH.), two physicists (pHYS. and EXP.) and a philosopher (PHIL.). However, although one of the authors is a theoretical physicist and the other a mathematician, the reader must not think that their opinions have been divided among the participants of the dialogues. We have tried to convey the inner tension of the topic under discussion and its openness. The attitudes of the participants reflect more the possible evaluations of the situation rather than the actual views of the authors. What is more, the subject "elementary particles" as dealt with in the 3 6 dialogue stretches over (2-3) 10 years of historical time and a space of 10 +/-1 pages of scientific literature. For this reason, a complete survey of it is un achievable. But, of course, every researcher constructs his own history of his science and sees a certain list of its main pOints. We have attempted to float several possible pictures of this kind. Therefore the fact that Math and Phys talk about the history of element ary particles is not an attempt to present the scientific history of this realm of physics.

These proceedings give fundamental information on the collision mechanisms of ions and atoms at relatively high energies and on their highly excited atomic states. The information derived from such studies can often be applied in other fields such as material analysis, dosimetry, the study of the upper atmosphere and controlled fusion. Phenomena involving the classical ion-atom collision fields, impact parameter dependences, quasimolecular and electron correlation effects, coherence phenomena, the electron and photon spectroscopy of highly charged projectile and recoil ions, the loss and capture of electrons, molecular and solid state effects, and different aspects of instrumentation are all discussed in this volume.

In the last twenty years polarized beams of slow neutrons have been used effectively in fundamental research in nuclear physics. Parity violation in nuclear fission and neutron optics was discoverd as well as the nuclear precession of neutrons and the coherent interference of spin channels in neutron capture by nuclei. Furthermore, these methods helped to understand better the neutron`s electric dipole moment and its beta decay. This book gives a thorough introduction to these experimental methods including the most recent techniques of generating and analyzing polarized neutral beams. It clearly shows the close relationship between elementary particle physics and nuclear physics, in particular in the section dealing with the effects caused by weak interactions. Special attention is paid to experiments which investigate the violation of quantum mechanical conservation laws. The book not only addresses specialists but also those interested in the foundations of elementary particle and nuclear physics. It is well suited as additional reading for students.

The Rationale for the Present Book Perhaps the most critical problem facing present-day particle physicistsis to delineate the relationship between classical and quantum systems. This relationship has many facets. Particle-waveduality is one. The concept of the point particle is another. And theconcept of particle mass is yet another. The electron, as the lightest of the charged particles, represents a fundamental "ground state,"and many of the essential problems in the murky area between the domainsofclassical and quantum physics can be brought into focus by studyingjust this one particle. Thus the present book is centered on questions that arise in connection with the electron, and in particular with its mass, which has remained an unsolved, and indeed almost unexplored, mystery. Each student ofphysics, beginner and professional alike, has to fashion for himselfa way of thinking about the electron. If, after reading this book, the reader views this topic somewhat differently than before, the efforts of the author will have been amply rewarded. When physicists were confronted with the properties of the electron, they made a conceptualleap into the unknown: they concluded that the electron does not obey classical laws with respect to mechanics (as connected to the spin of the electron), and also with respect to electrodynamics (as connected to the magnetic moment of the electron).

Advanced experimental techniques make quantum optics one of the most active fields in probing the fundamental laws of quantum theory. The contributions collected in this volume, by both theoreticians and experimentalists, give an overview of the most recent developments in fundamental quantum optics. Of particular interest is the physics of cooled and trapped particles. Other topics include atomic interferometry, quantum electrodynamics in a cavity, quantum measurement and much more. The level of presentation makes this book intelligible not only to the expert but also to a wide readership from engineering and physics.

Stochastic Dynamics, born almost 100 years ago with the early explanations of Brownian motion by physicists, is nowadays a quickly expanding field of research within nonequilibrium statistical physics. The present volume provides a survey on the influence of fluctuations in nonlinear dynamics. It addresses specialists, although the intention of this book is to provide teachers and students with a reliable resource for seminar work. In particular, the reader will find many examples illustrating the theory as well as a host of recent findings.

The existence of jets emanating from the central sources of radio galaxies and quasars was perhaps the most important discovery for our understanding of the nature of active galactic nuclei. These proceedings present reviews and research papers on extragalactic radio sources. The book begins witha discussion of the phenomenology and models of radio sources. The main partis devoted to detailed studies of jets by VLBI, to the information obtained about the structure of the central source as deduced from variability studies, to production, confinement and velocity of jets as well as to numerical simulations of the jet phenomenon. Reviews of the two best studied jets - those in the radio galaxy M87 and the quasar 3C273 - illustrate our current observational picture of extragalactic radio jets in all accessible wavelength ranges. A section on the influence of the environment on radio galaxies concludes the book. This topical volume addresses researchers and graduate students in astrophysics.

This volume comprises the recent development in the theoretical and experimental progress dedicated to trapped charged particles and related fundamental physics and applications. The content has been divided topic-wise covering basic questions of Fundamental Physics, Quantum and QED Effects, Plasmas and Collective Behavior and Anti-Hydrogen. More technical issues include Storage Ring Physics, Precision Spectroscopy and Frequency Standards, Highly Charged Ions in Traps, Traps for Radioactive Isotopes and New Techniques and Facilities. An applied aspect of ion trapping is discussed in section devoted to Applications of Particle Trapping including Quantum Information, Chemistry and Trace Analysis. Each topic has a more general introduction, but also more detailed contributions are included. A selection of contributions exemplifies the interdisciplinary nature of the research on trapped charged particles worldwide.
Reprinted from Hyperfine Interactions (HYPE) Volumes XXX

243 number n and orbital angular momentum 1, but also a total angular momentum 1 f = 1 +/- !. This modification lead to striking successes for the model. Almost without exception, the ground state spins of odd nuclei were found to be cor rectly predicted. Furthermore several other features of nuclei such as the occur rence of isomeric states and the values of magnetic dipole moments were explained, at least qualitatively. However the model completely failed to explain the large values of observed electric quadrupole moments and certain regularities in nuclear spectra, especially of rare earth nuclei. 4. 1950-1953. The emphatic success of the shell-model modified by a spin orbit force gave the necessary confidence and incentive to physicists to apply the model in detail to individual nuclei. Guided by parallel calculations in atomic spectroscopy, considerable effort was devoted to computing spectra of levels of nuclear systems with the so-called "Intermediate Coupling Model" in which the independent particle motion is considered to be perturbed by central particle particle interactions and spin-orbit forces. Computational labour restricts such calculations to nuclei near closed shells, say within four particles or holes of closed shells. This explains why only light nuclei (A < 20) and isolated groups of nuclei higher in the Periodic Table were thus treated. Usually such calculations were rewarded by agreement with experiment especially those for light nuclei 2 and 20S nuclei near the double closed shell at Pb 3.

Although used with increasing frequency in many branches of physics, random matrix ensembles are not always sufficiently specific to account for important features of the physical system at hand. One refinement which retains the basic stochastic approach but allows for such features consists in the use of embedded ensembles.

The present text is an exhaustive introduction to and survey of this important field. Starting with an easy-to-read introduction to general random matrix theory, the text then develops the necessary concepts from the beginning, accompanying the reader to the frontiers of present-day research. With some notable exceptions, to date these ensembles have primarily been applied in nuclear spectroscopy. A characteristic example is the use of a random two-body interaction in the framework of the nuclear shell model. Yet, topics in atomic physics, mesoscopic physics, quantum information science and statistical mechanics of isolated finite quantum systems can also be addressed using these ensembles.

This book addresses graduate students and researchers with an interest in applications of random matrix theory to the modeling of more complex physical systems and interactions, with applications such as statistical spectroscopy in mind.

1bis text is meant to be a view of the quantum mechanical fonnalism as it develops with the successive introduction of different types oftransfonnations. In particular, it is meant to help the readers with three tasks: acquainting themselves with a general and direct approach to the quantum mechanics of spin one-half and spin-one particles, primarily leptons, photons and massive vector bosons, and to some extent quarks; finding out what some of the related areas of current research interest are; and, last and foremost, trying to understand the subject, beginning with and stressing the principles involved. The exposition is based on finite-dimensional representations of the homogeneous Lorentz group, and the subsequent introduction of gauge transformations, of the Abelian and non Abelian varieties. Reference to classical mechanics is avoided. Acting on the simple basis spinors and vectors, Lorentz transfonnations generate wave and field functions. Equations are obtained by the relativistic generalization of the addition of angular momenta, the wave or field functions being the solutions. For zero mass the equations may be obtained as the limits of the equations for the massive cases or by the application of the Euclidian group in two dimensions. The latter approach is illuminating in that it uncovers a loss in generality resulting from the former. Identifying momenta as eigenvalues of translations demonstrates covariance under the inhomogeneous Lorentz or Poincare group. Various representations of wave and field functions are given.

Interferometry, the most precise measurement technique known today, exploits the wave-like nature of the atoms or photons in the interferometer. As expected from the laws of quantum mechanics, the granular, particle-like features of the individually independent atoms or photons are responsible for the precision limit, the shot noise limit. However this "classical" bound is not fundamental and it is the aim of quantum metrology to overcome it by employing entanglement among the particles. This work reports on the realization of spin-squeezed states suitable for atom interferometry. Spin squeezing was generated on the basis of motional and spin degrees of freedom, whereby the latter allowed the implementation of a full interferometer with quantum-enhanced precision.

Cosmogenic radionuclides are radioactive isotopes which are produced by natural processes and distributed within the Earth system. With a holistic view of the environment the authors show in this book how cosmogenic radionuclides can be used to trace and to reconstruct the history of a large variety of processes. They discuss the way in which cosmogenic radionuclides can assist in the quantification of complex processes in the present-day environment. The book aims to demonstrate to the reader the strength of analytic tools based on cosmogenic radionuclides, their contribution to almost any field of modern science, and how these tools may assist in the solution of many present and future problems that we face here on Earth. The book provides a comprehensive discussion of the basic principles behind the applications of cosmogenic (and other) radionuclides as environmental tracers and dating tools. The second section of the book discusses in some detail the production of radionuclides by cosmic radiation, their transport and distribution in the atmosphere and the hydrosphere, their storage in natural archives, and how they are measured. The third section of the book presents a number of examples selected to illustrate typical tracer and dating applications in a number of different spheres (atmosphere, hydrosphere, geosphere, biosphere, solar physics and astronomy). At the same time the authors have outlined the limitations of the use of cosmogenic radionuclides. Written on a level understandable by graduate students without specialist skills in physics or mathematics, the book addresses a wide audience, ranging from archaeology, biophysics, and geophysics, to atmospheric physics, hydrology, astrophysics and space science.

Ion implantation offers one of the best examples of a topic that starting from the basic research level has reached the high technology level within the framework of microelectronics. As the major or the unique procedure to selectively dope semiconductor materials for device fabrication, ion implantation takes advantage of the tremendous development of microelectronics and it evolves in a multidisciplinary frame. Physicists, chemists, materials sci entists, processing, device production, device design and ion beam engineers are all involved in this subject. The present monography deals with several aspects of ion implantation. The first chapter covers basic information on the physics of devices together with a brief description of the main trends in the field. The second chapter is devoted to ion im planters, including also high energy apparatus and a description of wafer charging and contaminants. Yield is a quite relevant is sue in the industrial surrounding and must be also discussed in the academic ambient. The slowing down of ions is treated in the third chapter both analytically and by numerical simulation meth ods. Channeling implants are described in some details in view of their relevance at the zero degree implants and of the available industrial parallel beam systems. Damage and its annealing are the key processes in ion implantation. Chapter four and five are dedicated to this extremely important subject.

The NATO Advanced Research Workshop on Fundamental Aspects of Inert Gases in Solids, held at Bonas, France from 16-22 September 1990, was the fifth in a series of meetings that have been held in this topic area since 1979. The Consultants' Meeting in that year at Harwell on Rare Gas Behaviour in Metals and Ionic Solids was followed in 1982 by the Jiilich Inter national Symposium on Fundamental Aspects of Helium in Metals. Two smaller meetings have followed-a CECAM organised workshop on Helium Bubbles in Metals was held at Orsay, France in 1986 while in February 1989, a Topical Symposium on Noble Gases in Metals was held in Las Vegas as part of the large TMS/AIME Spring Meeting. As is well known, the dominating feature of inert gas atoms in most solids is their high heat of solution, leading in most situations to an essentially zero solubility and gas-atom precipita tion. In organising the workshop, one particular aim was to target the researchers in the field of inert-gas/solid interactions from three different areas--namely metals, tritides and nuclear fuels-in order to encourage and foster the cross-fertilisation of approaches and ideas. In these three material classes, the behaviour of inert gases in metals has probably been most studied, partly from technological considerations-the effects of helium production via (n, a) reac tions during neutron irradiation are of importance, particularly in a fusion reactor environ ment-and partly from a more fundamental viewpoint."

In the interest of speed and economy the notation of the orig inal text has been retained so that the cross product of two vectors A and B is denoted by [AB], the dot product by (AB), the Laplacian operator by ~. etc. It might also be worth pointing out that the temperature is frequently expressed in energy units in the Soviet literature so that the Boltzmann constant will be missing in various familiar expressions. In matters of terminology, whenever pos sible several forms are used when a term is first introduced, e. g. , magnetoacoustic and magnetosonic waves, "probkotron" and mirror machine, etc. It is hoped in this way to help the reader to relate the terms used here with those in existing translations and with the conventional nomenclature. In general the system of literature citation used in the bibliographies follows that of the American Institute of Physics "Soviet Physics" series. Except for the cor rection of some obvious misprints the text is that of the original. We wish to express our gratitude to Academician Leontovich for kindly providing the latest corrections and additions to the Russian text. v CONTENTS Steady-State Plasma Flow in a Magnetic Field A. I. Morozov and L. S. Solov'ev Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Chapter 1. Acceleration Mechanisms , * * * * * * * * * * . 2 1. Microscopic Picture of Plasma Acceleration . . . . . . . . . . . . . . . . . . . 2 2.

This volume contains the papers presented at the NATO Advanced Research Workshop on Localization and Propagation o[ Classical Waves in Random and Periodic Media held in Aghia Pelaghia, Heraklion, Crete, May 26- 30, 1992. The workshop's goal was to bring together theorists and experimentalists from two related areas, localization and photonic band gaps, to highlight their common interests. The objectives of the workshop were (i) to assess the state of-the-art in experimental and theoretical studies of structures exhibiting classical wave band gaps and/or localization, (ii) to discuss how such structures can be fabricated to improve technologies in different areas of physics and engineering, and (iii) to identify problems and set goals for further research. Studies of the propagation of electromagnetic (EM) waves in periodic and/or disordered dielectric structures (photonic band gap structures) have been and continue to be a dynamic area of research. Anderson localization of EM waves in disordered dielectric structures is of fundamental interest where the strong ei-ei interaction efFects entering the eIectron-localization are absent.

While electromagnetic interactions were first used to probe the structure of elementary particles more than 20 years ago, their importance has only become fully evident in the last 10 years. In the resonance region, photo production experiments have provided clear evidence for simple quark model ideas, and confirmed the Melosh-transformed SU(6)w as a relevant symmetry classification. At higher energies, their most striking feature is their similarity to hadron-induced reactions, and they have provided fresh insight into the ideas developed to explain strong-interaction physics. New dimensions are added by taking the photon off mass shell, both in the spacelike region, where the development of high-energy electron and muon beams has led to the discovery and study of scaling and the intro duction of "partons," and even more dramatically in the timelike region, where the development of high-energy electron-positron storage rings has led to the exciting discoveries of the last four years. In view of the immense interest stimulated by these developments, an extensive review of our present state of knowledge is both timely and useful. Because of the very wide range of the subject, a cooperative venture presents itself as the most suitable format and is the one we have adopted here. The emphasis throughout is primarily, but not entirely, on phenomenology, concentrating on describing the main features of the experimental data and on the theoretical ideas used directly in their inter pretation."