The West Experimental Area at the CERN SPS

The West Area at the CERN SPS has recently been rebuilt to provide two versatile secondary and/or tertiary test beams, the X5 and X7, which each have been upgraded to a top momentum of 250 GeV/c. In this note we describe the design, operational modes and performance of these new West Area beams

The west experimental area at the CERN SPS (Revised version after T1 displacement)

The West Area at the CERN SPS has recently been rebuilt to provide two versatile secondary and/or tertiary test beams, the X5 and X7, which each have been upgraded to a top momentum of 250 GeV/c. In this note we describe the design, operational modes and performance of these new West Area beams.This is a revision of a previous report CERN SL-99-013 EA, updated following the displacement of the T1 primary target

Where to Install the I224 Detector

Recently M.Ambrosio et al have submitted a Letter of Intent to the SPSC, in which they propose to expose a neutrino detector (much smaller but of a type similar to Monolith) to the neutrinos that accompany the M2 muon beam in the CERN North Area. In fact a significant neutrino flux (almost 2 10^9 nu per SPS cycle) is produced during the muon running of COMPASS at full intensity, out of which some 5 10^8 would traverse a detector with a section of 2 meters diameter. These neutrinos pass well below the COMPASS experiment, located in experimental hall EHN2. The neutrino detector will be housed in a new experimental hall, with a floor level, depending on the site chosen, several meters underground. On their way towards the detector, the neutrinos would traverse one or several RF cavities, recuperated from LEP, which may induce neutrino oscillations. Another part of the proposal addresses the question of speed of flight of the neutrinos by measuring the time difference between the neutrino interaction and the time of the muon from the same pion decay. This note compares and proposes suitable locations for the different detector components

CLIC Muon Sweeper Design

There are several background sources which may affect the analysis of data and detector performans at the CLIC project. One of the important background source is halo muons, which are generated along the beam delivery system (BDS), for the detector performance. In order to reduce muon background, magnetized muon sweepers have been used as a shielding material that is already described in a previous study for CLIC [1]. The realistic muon sweeper has been designed with OPERA. The design parameters of muon sweeper have also been used to estimate muon background reduction with BDSIM Monte Carlo simulation code [2, 3].Comment: Talk presented at the International Workshop on Future Linear Colliders (LCWS15), Whistler, Canada, 2-6 November 2015, 7 pages, 6 figure

The simultaneous and nearly-collinear K0K^{0} beams for experiment NA48

A system of simultaneous and nearly-collinear beams of long- and short-lived neutral kaons has been installed and extensively studied. These beams form an integral part of the NA48 experiment at the CERN SPS, which aims to study direct CP-violation. The beam splitting is achieved by a novel application of a bent silicon crystal. The principles and design of these beams, as well as their performance are described

The simultaneous long- and short-lived neutral kaon beams for experiment NA48

Simultaneous, nearly-collinear beams of long- and short-lived neutral kaons are an essential feature of the precision CP-violation experiment NA48 *) at the SPS. The present report describes the design and performance of these beams in relation to the requirements of the experiment

The Influence of Radiation Damage on the Deflection of High-Energy Beams in Bent Silicon Crystals

Experimental results obtained for deflection of 450 GeV/c protons channeling along the {111} planes in a bent, strongly irradiated silicon crystal are presented. A comparison between the deflection efficiencies in irradiated areas and non-irradiated areas in the crystal shows that irradiation by 2.4 · 1020 protons/cm2 leads to a reduction of around 30 % in deflection efficiency. As a consequence, beam-splitting and extraction from an accelerator by means of a bent crystal are feasible solutions at high energies even for intense beams and during long periods

Record deflection efficiencies measured for high energy protons in a bent germanium crystal

New experimental results on the deflection of high energy protons in a bent germanium crystal are presented. At 450 GeV/c, the 50 mm long crystal gave record deflection efficiencies up to 60% for small angles (1 mrad), while at angles as large as 12 mrad, the efficiency is about 25 times larger than for a silicon crystal of the same size. The experimental results are in good agreement with a model for channeling and deflection developed by Ellison and give - together with a similar comparison for a 200 GeV/c beam - confidence in extrapolations to higher energies (e.g. to LHC), other crystal materials or different deflection angles

First observation of the deflection of a 33 TeV Pb ion beam in a bent silicon crystal

For the first time, the deflection of an ultra-relativistic, fully stripped Pb82+ ion beam in a bent silicon crystal has been observed. The ions were provided by the CERN-SPS in the H4 beam at a momentum of 400 GeV/c per unit of charge. A 60 mm long silicon crystal, bent over 50 mm to give a 4 mrad deflection angle, was used in this experiment. The measured Pb ion deflection efficiency is comparable to the one obtained with protons at an equivalent ratio of momentum per charge, and is found to be about 15\% for a beam with a divergence of 35 microradians (FWHM). The interaction rate observed in a background counter is found to drop when the crystal is well aligned with the beam. This corroborates further the channeling model, which predicts that channeled ions are steered away from regions of high electron densities as well as the nuclei in the crystal