Single diffraction at high momentum transfers

In this report an exponential trajectory for the Pomeron is introduced for better description of the inclusive differential cross-section of single diffraction at high 4-momentum transfers

Radiation Heating of Primary Collimators at Ramping

A time-dependent temperature map is derived for the primary jaw of the momentum collimation system during the high transient loss period which is to occur at the beginning of the ramp of acceleration. An adequate margin factor is obtained for a loss of 5% of the nominal stored beam and for the nominal parabolic ramping curve

Proton Losses Upstream of IP8 in LHC

In this report we analyse possible distant sources of proton losses in the long straight section around IP8. These sources can be collisions of the beam protons with nuclei of residual gas in the arcs, betatron cleaning inefficiency and proton-proton collisions in IR1

Machine Induced Background in the Low Luminosity Insertions of the LHC

The effect of the machine induced background is studied for the low luminosity insertions of the LHC. Estimations for the fluxes of the secondary particles, induced by the proton losses in the LHC, are presented for several running conditions of the collider. The formation of the background in the machine structure is discussed

Cascade Simulations for the LHC Betatron Cleaning Insertion

A cascade calculation is done in the IR7 betatron cleaning insertion of LHC. It uses a detailed map of the primary losses and an accurate model of the straight section. One aim is to design a compact shielding which fits in the tight section of the tunnel. The same study allows to define radiation hardness properties of the equipment to be installed in the section and to locate areas of low activi ty for the installation of sensitive equipment

The study of the machine-induced background and its applications at the LHC

We present the recent advances in the analysis of the machine-induced background generation and formation at the LHC. Different aspects of the study of the machine background problem at the LHC are reviewed, including the background production at the different stages of the machine operation, the role and influence on the background from the collimators in the experimental insertions and the background shielding. The potential use of the machine background for the purposes of detector testing and alignment is also discussed

Machine-Related Backgrounds in the SiD Detector at ILC

With a multi-stage collimation system and magnetic iron spoilers in the tunnel, the background particle fluxes on the ILC detector can be substantially reduced. At the same time, beam-halo interactions with collimators and protective masks in the beam delivery system create fluxes of muons and other secondary particles which can still exceed the tolerable levels for some of the ILC sub-detectors. Results of modeling of such backgrounds in comparison to those from the e+ e- interactions are presented in this paper for the SiD detector.Comment: 29 pages, 34 figures, 7 table

Requirements for the LHC collimation system

The LHC requires efficient collimation during all phases of the beam cycle. Collimation plays important roles in prevention of magnet quenches from regular beam diffusion, detection of abnormal beam loss and subsequent beam abort, radiation protection, and passive protection of the superconducting magnets in case of failures. The different roles of collimation and the high beam power in the LHC impose many challenges for the design of the collimation system. In particular, the collimators must be able to withstand the expected particle losses. The requirements for the LHC collimation system are presented