Beam halo scraping schemes have been explored in the 50 x 50 GeV and 2 x 2 TeV??− colliders using both absorbers and electrostatic deflectors. Utility sections have been specially designed into the rings for scraping. Results of realistic STRUCT- MARS Monte-Carlo simulations show that for the low-energy machine a scheme with a 5 m long steel absorber suppresses losses in the interaction region by three orders of magnitude. The same scraping efficiency at 2 TeV is achieved only by complete extraction of beam halo from the machine. The effect of beam-induced power dissipation in the collider superconducting magnets and detector backgrounds is shown both for the first few turns after injection and for the rest of the cycle.

Beam halo scraping schemes have been explored in the 50 x 50 GeV and 2 x 2 TeV[mu][sup+][mu][sup -] colliders using both absorbers and electrostatic deflectors. Utility sections have been specially designed into the rings for scraping. Results of realistic STRUCT- MARS Monte-Carlo simulations show that for the low-energy machine a scheme with a 5 m long steel absorber suppresses losses in the interaction region by three orders of magnitude. The same scraping efficiency at 2 TeV is achieved only by complete extraction of beam halo from the machine. The effect of beam-induced power dissipation in the collider superconducting magnets and detector backgrounds is shown both for the first few turns after injection and for the rest of the cycle.

This book documents comprehensive reviews and state-of-the-art studies in the dynamics, diagnostics, and collimation of charged-particle beam halo and in beam-beam interaction. Challenges and solutions to major accelerator facilities in Europe, Asia, and America in the domain of high intensity, high energy, and high brightness charged particles are presented. Latest breakthroughs in physical analysis, engineering design, and experimental tests are included.

A possibility to improve the Tevatron beam halo scraping using a bent channeling crystal instead of a thin scattering primary collimator is studied. To evaluate the efficiency of the system, realistic simulations have been performed using the CATCH and STRUCT Monte Carlo codes. It is shown that the scraping efficiency can be increased and the accelerator-related backgrounds in the CDF and DØ collider detectors can be reduced by about one order of magnitude. Results on scraping efficiency versus thickness of amorphous layer of the crystal, crystal alignment and its length are presented.

This book contains the proceedings of the 1999 ICFA workshop on the physics of high brightness beams. The workshop took a snapshot in time of a fast moving, interdisciplinary field driven by advanced applications such as high gradient, high energy physics linear colliders, high gain free electron lasers, heavy ion fusion, and transmutation of nuclear materials. While the field of high brightness beam physics has traditionally been divided into disparate electron and heavy ion communities, the workshop brought the two types of researchers together, so that a sharing of insights and methods could be achieved. Thus, this book represents a unifying step in the development of the diverse fascinating discipline of high brightness beam physics, with its challenges rooted in collective, nonlinear particle motion and ultra-high electromagnetic energy density.

Numerical calculations have been performed to evaluate the performance of a simple beam scraping system in the lattice of a rapid cycling (30 Hz) proton accelerator designed to be a high intensity spallation neutron source. The assumption has been made that beam loss will be dominated by rf capture inefficiency at injection (600 MeV kinetic) which is simulated as described below. Comparison is made with a ''sample calculation'' intended to illustrate betatron (beam halo) scraping at full energy which was assumed to be 3 GeV. The parameters of the lattice are those of the design as of April, 1993. The results described here are restricted to a geometry wherein the primary scraper is treated as an aperture in the X (horizontal) coordinate. Evaluation of the efficacy of two dimensional scrapers, or scraping systems which employ magnetic fields remain as topics for further study. The purpose of this study was to determine to what extent beam losses can be confined to a local region of the proposed lattice. The remainder of this note describes the general methodology employed, the rf capture beam loss simulation, and the beam halo growth ''sample calculation''. Section V briefly summarizes the results of this study.