Article ID Journal Published Year Pages File Type
1684879 Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 2009 5 Pages PDF
Abstract
When a lead beam is collimated in the CERN LHC some of the ions fragment in the collimators causing problems downstream. For design purposes the fragmentation probability needs to be assessed. At LHC energies (γ≃3000; the Lorentz-factor γ is the total energy of an ion in units of its rest energy) electromagnetic dissociation dominates the fragmentation in medium to heavy target materials. Due to the extended range of the interaction at high energies, atomic screening affects the dissociation in the LHC collimators. We determine the magnitude of the reduction in cross section relative to the unscreened case for various collimator materials and find a significant effect for tungsten, the heaviest candidate planned for use.
Related Topics
Physical Sciences and Engineering Materials Science Surfaces, Coatings and Films
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