"Nature performs not hing vainly, and makes nothing unnecessary" Aristotle Interest in the passage of charged particles through crystals first appeared at the beginning of this century following experiments on x-ray diffraction in crystallattices, which provided the proof of an ordered distribution of atoms in a crystal. Stark [1] put forward the hypothesis that certain directions in a crystal should be relatively transparent to charged particles. These first ideas on the channeling of charged particles in crystals were forgotten but became topical again in the early 1960s when the channeling effect was rediscovered by computer simulation [2] and in experiments [3] that revealed anomalously long ion ranges in crystals. The orientational ef fects during the passage of charged particles through crystals have been found for a whole range of processes characterized by small impact parameters for collisions between particles and atoms: nuclear reactions, large-angle scatter ing, energy losses. Lindhard explained the channeling of charged particles in crystals [4]. The results of the numerous investigations into the channeling of low-energy (amounting to several MeV) charged particles in crystals have been summarized in several monographs and reviews [5~8l.

TeV-range bent crystal channeling has interesting advantages for several applications at high energy accelerators. Observations of enhanced deflection over the whole arc of a bent crystal at RHIC and recently at the Tevatron may be due to a process called ''volume reflection''. More investigations of volume reflection and of the complimentary process, volume capture, are needed. So-called quasimosaic bending processes also deserve additional study. Negative particle channeling may be relevant to channeling collimation for electron machines. Electron and positron channeling and channeling radiation are interwoven so that the impact of channeling radiation on applications needs to be better understood. Beams in the 0.1 to 1 GeV range may be useful for some of these investigations. Finally there has been little or no study of positive and negative muon channeling. The current understanding of these topics and the desirability of further work is reviewed.

The possibility of using channeling as a tool for high energy particle physics has now been extensively investigated. Bent crystals have been used as an accelerator extraction element and for particle deflection. Applications as accelerating devices have been discussed but appear remote. The major advantage in using a bent crystal rather than a magnet is the large deflection that can be achieved in a short length. The major disadvantage is the low transmission. A good understanding of dechanneling is important for applications. 43 refs., 1 fig., 3 tabs.

This proceedings volume of the 3rd International Workshop on Quantum Aspects of Beam Physics, presents the latest advances in beam dynamics. The frontiers of beam research point to increasingly high energy, greater brightness and lower emittance beams with ever-increasing particle species. These demands have triggered a rapidly growing number of beam phenomena that involve quantum effects. In addition to the more established topics, this volume covers topics on high energy-density particle and photon beams for laboratory astrophysics investigations, as well as the application of beam physics expertise to astrophysics studies. Other exciting new topics are the physics of ultra-cold or condensed beams, such as the ''''crystalline beams'''' and the BoseOCoEinstein condensate ''''atom lasers''''. This book will be a valuable source of reference to readers interested in the interdisciplinary frontiers of ''''quantum beam physics'''' that involve beam physics, particle physics, laser science, astrophysics, condensed matter physics, nuclear and atomic physics. The proceedings have been selected for coverage in: . OCo Index to Scientific & Technical Proceedings- (ISTP- / ISI Proceedings). OCo Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings). OCo CC Proceedings OCo Engineering & Physical Sciences."

The development of coherent radiation sources for sub-angstrom wavelengths - i.e. in the hard X-ray and gamma-ray range - is a challenging goal of modern physics. The availability of such sources will have many applications in basic science, technology and medicine and in particular, they may have a revolutionary impact on nuclear and solid state physics, as well as on the life sciences. The present state-of-the-art lasers are capable of emitting electromagnetic radiation from the infrared to the ultraviolet, while free electron lasers (X-FELs) are now entering the soft X-ray region. Moving further, i.e. into the hard X and/or gamma ray band, however, is not possible without new approaches and technologies. In this book we introduce and discuss one such novel approach -the radiation formed in a Crystalline Undulator - whereby electromagnetic radiation is generated by a bunch of ultra-relativistic particles channeling through a periodically bent crystalline structure. Under certain conditions, such a device can emit intensive spontaneous monochromatic radiation and even reach the coherence of laser light sources. Readers will be presented with the underlying fundamental physics and be familiarized with the theoretical, experimental and technological advances made during the last one and a half decades in exploring the various features of investigations into crystalline undulators. This research draws upon knowledge from many research fields - such as materials science, beam physics, the physics of radiation, solid state physics and acoustics, to name but a few. Accordingly, much care has been taken by the authors to make the book as self-contained as possible in this respect, so as to also provide a useful introduction to this emerging field to a broad readership of researchers and scientist with various backgrounds. This new edition has been revised and extended to take recent developments in the field into account.

This BriefBook is a much extended glossary or a much condensed handbook, depending on the way one looks at it. In encyclopedic format, it covers subjects in statistics, computing, analysis, and related fields, resulting in a book that is both an introduction and a reference for scientists and engineers, especially experimental physicists dealing with data analysis.