While information exists on high energy negative particle channeling there has been little study of the challenges of negative particle bending and channeling collimation. Partly this is because negative dechanneling lengths are relatively much shorter. Electrons are not particularly useful for investigating negative particle channeling effects because their material interactions are dominated by channeling radiation. Another important factor is that the current central challenge in channeling collimation is the proton-proton Large Hadron Collider (LHC) where both beams are positive. On the other hand in the future the collimation question might reemerge for electon-positron or muon colliders. Dechanneling lengths increase at higher energies so that part of the negative particle experimental challenge diminishes. In the article different approaches to determining negative dechanneling lengths are reviewed. The more complicated case for axial channeling is also discussed. Muon channeling as a tool to investigate dechanneling is also discussed. While it is now possible to study muon channeling it will probably not illuminate the study of negative dechanneling.

The book "Channeling 2008", Charged and Neutral Particles Channeling Phenomena, is formed by the same title conference contributions. This volume includes papers by leading researchers from different world centers. Their recent results on the coherent phenomena of charged and neutral particles propagating through the structures of various sizes and periodicities are included here, along with historical reviews by pioneers of coherent Bremsstrahlung and channeling radiation as well as crystal channeling collimation.

The book “Channeling 2008”, Charged and Neutral Particles Channeling Phenomena, is formed by the same title conference contributions. This volume includes papers by leading researchers from different world centers. Their recent results on the coherent phenomena of charged and neutral particles propagating through the structures of various sizes and periodicities are included here, along with historical reviews by pioneers of coherent bremsstrahlung and channeling radiation as well as crystal channeling collimation.

The book ?Channeling 2008?, Charged and Neutral Particles Channeling Phenomena, is formed by the same title conference contributions. This volume includes papers by leading researchers from different world centers. Their recent results on the coherent phenomena of charged and neutral particles propagating through the structures of various sizes and periodicities are included here, along with historical reviews by pioneers of coherent bremsstrahlung and channeling radiation as well as crystal channeling collimation.

Channeling, by its nature, involves a wide and disparate range of disciplines. Crystal preparation, material science, accelerator physics, sophisticated theoretical analysis and, of course, channeling itself all must work in concert in a research program. In spite of the gulfs separating some of these activities, researchers have drawn together over the last decade to carry out remarkable experiments in relativistic channeling and channeling radiation. Several informal workshops on high-energy channeling have been held over ~he years at Aarhus and Fermilab. However, with the vigorous progress in the field in the last several years it became clear that a more formal, comprehensive workshop was needed along with a book that covered the whole spectrum of the new developments, probed the future, and also laid out some of the foundations of the subject. This volume is the outcome of that process. The organization and preparation of both the volume and the workshop owe much to several outstanding scientific committees. The membership of these included J. Andersen (Aarhus), S. Baker (Fermilab), B. Berman (G. Washington), G. Bologna (Torino), E. Bonderup (Aarhus), S. Datz (Oak Ridge), J. Forster (Chalk River), F. Fujimoto (Tokyo), W. Gibson (Albany), I. Mitchell (Chalk River), Y. Ohtsuki (Waseda), R. Pantell (Stanford), S. Picraux (Sandia), J. Remillieux (Lyon), A. Saenz (NRL), V. Schegelsky (Gatchina), C. Sun (Albany), H. tiberall (Catholic U. ), E. Uggerh¢j (CERN), and R. Wedell (Humboldt). Others from across the spectrum of scientific disciplines agreed to serve as session chairmen.

This book discusses possibilities and perspectives for designing and practical realization of novel intensive gamma-ray crystal-based light sources that can be constructed through exposure of oriented crystals—linear, bent and periodically bent, to beams of ultrarelativistic positrons and electrons. The book shows case studies like the tunable light sources based on periodically bent crystals that can be designed with the state-of-the-art beam facilities. A special focus is given to the analysis of generation of the gamma rays because the current technologies based on particle motion in the magnetic field become inefficient or incapable to achieve the desired gamma rays’ intensities. It is demonstrated that the intensity of radiation from crystal-based light sources can be made comparable to or even higher than what is achievable in conventional synchrotrons and undulators operating although in the much lower photon energy range. By exploring the coherence effects, the intensity can be boosted by orders of magnitude. The practical realization of such novel light sources will lead to the significant technological breakthroughs and societal impacts similar to those created earlier by the developments of lasers, synchrotrons and X-rays free-electron lasers. Readers learn about the underlying fundamental physics and familiarize with the theoretical, experimental and technological advances made during last two decades in exploring various features of investigations into crystal-based light sources. This research draws upon knowledge from many research fields, such as material science, beam physics, physics of radiation, solid-state physics and acoustics, to name but a few. The authors provide a useful introduction in this emerging field to a broad readership of researchers and scientists with various backgrounds and, accordingly, make the book as self-contained as possible.

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.