Often, a new area of science grows at the confines between recognised subject divisions, drawing upon techniques and intellectual perspectives from a diversity of fields. Such growth can remain unnoticed at first, until a characteristic fami ly of effects, described by appropriate key words, has developed, at which point a distinct subject is born. Such is very much the case with atomic 'giant resonances'. For a start, their name itself was borrowed from the field of nuclear collective resonances. The energy range in which they occur, at the juncture of the extreme UV and the soft X-rays, remains to this day a meeting point of two different experimental techniques: the grating and the crystal spectrometer. The impetus of synchrotron spectroscopy also played a large part in developing novel methods, described by many acronyms, which are used to study 'giant resonances' today. Finally, although we have described them as 'atomic' to differentiate them from their counterparts in Nuclear Physics, their occurrence on atomic sites does not inhibit their existence in molecules and solids. In fact, 'giant resonances' provide a new unifying theme, cutting accross some of the traditional scientific boundaries. After much separate development, the spectroscopies of the atom in various environments can meet afresh around this theme of common interest. Centrifugal barrier effects and 'giant resonances' proper emerged almost simultaneously in the late 1960's from two widely separated areas of physics, namely the study of free atoms and of condensed matter.

Advances in Atomic, Molecular, and Optical Physics

This comprehensive volume, edited by a senior technical staff member at SEMATECH, is the authoritative reference book on EUV source technology. The volume contains 38 chapters contributed by leading researchers and suppliers in the EUV source field. Topics range from a state-of-the-art overview and in-depth explanation of EUV source requirements, to fundamental atomic data and theoretical models of EUV sources based on discharge-produced plasmas (DPP) and laser-produced plasmas, to a description of prominent DPP and LPP designs and other technologies for producing EUV radiation. Additional topics include EUV source metrology and components (collectors, electrodes), debris mitigation, and mechanisms of component erosion in EUV sources. The volume is intended to meet the needs of both practitioners of the technology and readers seeking an introduction to the subject.

Since 1981 there has been an attempt in Europe to organize a series of small meetings/workshops/tavole rotonde with the aim of bringing together physi cists and chemists interested in problems concerning atoms or molecules in teracting with external photons where the continua are investigated. The number of problems that fall into this category turns out to be vast. However, it is not possible to make a strict separation into problems con cerning atomic and molecular collisions and those related to the usual spec troscopy. This admixture of two disciplines, discussions on the role of photons and on the interaction of external electromagnetic fields with the continuum provided a central motivation for these workshops. The fourth of this series of meetings was held at Cortona between June 16 and 20, 1986. It was attended by about 100 researchers in the field and there were 43 presentations, all having equal time. These talks form the subject matter of this volume. The idea of publishing the proceedings of these meetings is not new. It allows one to have small meetings in which the subject matter can be discussed at length in a lively atmosphere. However, after the meeting is over, the speakers can collect their thoughts and produce articles in which the results of their interaction with the other participants can be incorporated.

The last few years have seen some remarkable advances in the understanding of atomic phenomena. It is now possible to isolate atomic systems in traps, measure in coincidence the fragments of collision processes, routinely produce, and study multicharged ions. One can look at bulk matter in such a way that the fundamental atomic character is clearly evident and work has begun to tease out the properties of anti matter. The papers in this book reflect many aspects of modem Atomic Physics. They correspond to the invited talks at a conference dedicated to the study of "New Directions in Atomic Physics," which took place in Magdalene College, Cambridge in July of 1998. The meeting was designed as a way of taking stock of what has been achieved and, it was hoped, as a means of stimulating new research in new areas, along new lines. Consequently, an effort was made to touch on as many directions as we could in the four days of the meeting. We included some talks which overviewed whole subfields, as well as quite a large number of research contributions. There is a unity to Physics and we tried to avoid any artificial division between theory and experiment. We had roughly the same number of talks from those who are primarily concerned with making measurements, and from those who spend their lives trying to develop the theory to describe the experiments.

Specialist Periodical Reports provide systematic and detailed review coverage of progress in the major areas of chemical research. Written by experts in their specialist fields the series creates a unique service for the active research chemist, supplying regular critical in-depth accounts of progress in particular areas of chemistry. For over 80 years the Royal Society of Chemistry and its predecessor, the Chemical Society, have been publishing reports charting developments in chemistry, which originally took the form of Annual Reports. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The Annual Reports themselves still existed but were divided into two, and subsequently three, volumes covering Inorganic, Organic and Physical Chemistry. For more general coverage of the highlights in chemistry they remain a 'must'. Since that time the SPR series has altered according to the fluctuating degree of activity in various fields of chemistry. Some titles have remained unchanged, while others have altered their emphasis along with their titles; some have been combined under a new name whereas others have had to be discontinued. The current list of Specialist Periodical Reports can be seen on the inside flap of this volume.

Leading investigators offer the first comprehensive study of gas phase photoionization research in the VUV and soft X-ray regime since the massive employment of synchrotron radiation as a spectroscopic tool. Chapters cover all aspects of photoionization phenomena from total cross sections to highly differentiated measurements such as coincidence experiments and spin-resolved electron spectroscopy. This work is abundant with illustrations.

Detailed discussions on many of the recent advances in the many-body theory of atomic structure are presented by the leading experts around the world on their respective specialized approaches. Emphasis is given to the photoionization dominated by the resonance structures, which reveals the effect of the multi-electron interaction in atomic transitions involving highly correlated atomic systems. Recent experimental developments, stimulated by the more advanced applications of intense lasers and short wavelength synchrotron radiation, are also reviewed. This book brings together a comprehensive theoretical and experimental survey of the current understanding of the basic physical processes involved in atomic processes.

Quantum mechanics provides the fundamental theoretical apparatus for describing the structure and properties of atoms and molecules in terms of the behaviour of their fundamental components, electrons and nudeL For heavy atoms and molecules containing them, the electrons can move at speeds which represent a substantial fraction of the speed of light, and thus relativity must be taken into account. Relativistic quantum mechanics therefore provides the basic formalism for calculating the properties of heavy-atom systems. The purpose of this book is to provide a detailed description of the application of relativistic quantum mechanics to the many-body prob lem in the theoretical chemistry and physics of heavy and superheavy elements. Recent years have witnessed a continued and growing interest in relativistic quantum chemical methods and the associated computa tional algorithms which facilitate their application. This interest is fu elled by the need to develop robust, yet efficient theoretical approaches, together with efficient algorithms, which can be applied to atoms in the lower part of the Periodic Table and, more particularly, molecules and molecular entities containing such atoms. Such relativistic theories and computational algorithms are an essential ingredient for the description of heavy element chemistry, becoming even more important in the case of superheavy elements. They are destined to become an indispensable tool in the quantum chemist's armoury. Indeed, since relativity influences the structure of every atom in the Periodic Table, relativistic molecular structure methods may replace in many applications the non-relativistic techniques widely used in contemporary research.