Beam Losses far downstream of the High Luminosity Interaction Points of LHC

We consider proton-proton collisions in LHC in which one proton at least leaves the collision point with a small longitudinal momentum transfer. The rate of these events at the nominal luminosity of LHC can induce quenches in some superconducting magnets of the downstream part of the straight-section and of the dispersion suppressor. We propose a safe local collimation scheme and present the residual impact on the cryogenic load

Beam Loss and Collimation at LHC, CERN-LHC-Project-Report-603

Beam loss and collimation issues at LHC are outlined with some emphasis on bibliographic material

Beam Loss and Collimation at LHC, CERN-LHC-Project-Report-663

After a short review of past collimation work at LHC, the conception and baseline of the LHC collimation system are described. Abort-gap cleaning and beam loss monitoring are also discussed

An Improved Cllimation System for the LHC

The handling of the high-intensity LHC beams in a super-conducting environment requires a high-robustness collimation system with unprecedented cleaning efficiency. For gap closures down to 2.2 mm no beam instabilities must be induced from the collimator impedance. A difficult trade-off between collimator robustness, cleaning efficiency and collimator impedance is encountered. The conflicting LHC requirements are resolved with a phased approach, relying on low Z collimators for maximum robustness and hybrid metallic collimators for maximum performance. Efficiency is further enhanced with an additional cleaning close to the insertion triplets. The machine layouts have been adapted to the new requirements. The LHC collimation hardware is presently under design and has entered into the prototyping and early testing phase. Plans for collimator tests with beam are presented