A new concept for the water supply at CERN

The present state of the station Le Vengeron (the main pumping station supplying CERN with drinking water), and also to comply with the new Swiss standards impose a thorough consolidation and upgrade of this station which is shared with the Services Industriels de Genève (SIG). The total cost of the works (around 62 MCHF) would be shared proportionally to the nominal flow-rate demand which, at present, is of 2/3 for CERN and 1/3 for SIG. An alternative to the above is a complete review of CERN's water consumption, reducing our needs by half, thus allowing savings in both investment and operation. This reduction in investment cost would be diverted towards much needed consolidation works for the existing facilities within CERN. This paper also reviews the planning and possible ways for the execution of the works and the future responsibilities of operation of the water distribution systems (drinking and machine) inside CERN's sites

ST-ATLAS infrastructure coordination

The ST division launched a collaboration programme with the LHC (experiments and machine) management, by appointing the so-called ST coordinators. The role of the coordinator is to smooth out the relationships amongst representatives of the infrastructure groups, not exclusively within the ST division. This role is nevertheless bound to change as the project unfolds into its different phases. For the time being though, the coordinator's task is to centralize all requests for information from, and provide support to, the collaboration. In the case of ATLAS, the first months of this collaboration have already given some good results, which will be reported in this and future papers. The present paper is to be understood as a progress report summarizing the main items which have been dealt with up to now

Smoke control and "Désenfumage" systems

The intention of this technical note is to explain what a smoke control (SC) system is, and to what extent SC systems (and derivatives) are used at CERN. The role of ST Division in relation to these systems will be analysed, and some improvements suggested. This note is particularly addressed to people with local safety responsibility (TSO, DSO, etc.) but it also might be of interest to the CERN user in general. The complete list of facilities, under the responsibility of ST, having any relation with the control of smoke can be found at the end of the note

The LHC experiments as seen from the Technical Sector

Since the beginning of the collaboration between the ST division and the LHC experiments, already in 1998, the technical sector has provided different structures for the support of the experiments, aiming to coordinate all the activities, which traditionally belong in the technical sector's mandate, like civil engineering and structures, cooling and ventilation, cranes and transport, electricity, gas, etc. A picture of the last year's activity, mainly concentrated on the ATLAS and CMS experiments, shows how the synergies between project managers, staff involved and group structures can strongly improve the service level in the technical domain. This closer collaboration has facilitated the development of further ties linked to the competence available in the groups, and of great interest to the experiments. The steady rise in demand confirms that the choice, made by the experiments, confirms that the technical sector support is a real need in this are

ATLAS Infrastructure

This document describes the civil engineering and infrastructure work done on the surface and underground for the ATLAS experiment at point 1 of the LHC ring

An Experimental Area for Short Baseline Neutrino Physics on the CERN Neutrino Beam to Gran Sasso

A new neutrino beam line from the CERN SPS to the Gran Sasso laboratory in Italy is presently under study. The new neutrino beam will allow both long baseline and short baseline neutrino oscillation experiments to be performed. This report presents a conceptual design of the short baseline experimental area to be located at a distance of 1858 m from the neutrino target

Conceptual design of the SPL II: A high-power superconducting H−H^- linac at CERN

An analysis of the revised physics needs and recent progress in the technology of superconducting RF cavities have led to major changes in the speci cation and in the design for a Superconducting Proton Linac (SPL) at CERN. Compared with the rst conceptual design report (CERN 2000012) the beam energy is almost doubled (3.5 GeV instead of 2.2 GeV), while the length of the linac is reduced by 40% and the repetition rate is reduced to 50 Hz. The basic beam power is at a level of 45MW and the approach chosen offers enough margins for upgrades. With this high beam power, the SPL can be the proton driver for an ISOL-type radioactive ion beam facility of the next generation (`EURISOL'), and for a neutrino facility based on superbeam C beta-beam or on muon decay in a storage ring (`neutrino factory'). The SPL can also replace the Linac2 and PS Booster in the low-energy part of the CERN proton accelerator complex, improving signi cantly the beam performance in terms of brightness and intensity for the bene t of all users including the LHC and its luminosity upgrade. Decommissioned LEP klystrons and RF equipment are used to provide RF power at a frequency of 352.2 MHz in the lowenergy part of the accelerator. Beyond 90 MeV, the RF frequency is doubled to take advantage of more compact normal-conducting accelerating structures up to an energy of 180 MeV. From there, state-ofthe- art, high-gradient, bulk-niobium superconducting cavities accelerate the beam up to its nal energy of 3.5 GeV. The overall design approach is presented, together with the progress that has been achieved since the publication of the rst conceptual design report

The SPL (II) at CERN, a Superconducting 3.5 GeV H- Linac

A revision of the physics needs and recent progress in the technology of superconducting (SC) RF cavities have triggered major changes in the design of a SC H-linac at CERN. With up to 5MW beam power, the SPL can be the proton driver for a next generation ISOL-type radioactive beam facility (âEURISOLâ) and/or supply protons to a neutrino () facility (conventional superbeam + beta-beam or -factory). Furthermore the SPL can replace Linac2 and the PS booster (PSB), improving significantly the beam performance in terms of brightness, intensity, and reliability for the benefit of all proton users at CERN, including LHC and its luminosity upgrade. Compared with the first conceptual design, the beam energy is almost doubled (3.5GeV instead of 2.2 GeV) while the length is reduced by 40%. At a repetition rate of 50 Hz, the linac reuses decommissioned 352.2MHz RF equipment from LEP in the low-energy part. Beyond 90MeV the RF frequency is doubled, and from 180MeV onwards high-gradient SC bulkniobium cavities accelerate the beam to its final energy of 3.5GeV. This paper presents the overall design approach, together with the technical progress since the first conceptual design in 2000

Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions

Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV