The ATLAS detector control system

The ATLAS experiment is one of the multi-purpose experiments at the Large Hadron Collider (LHC) at CERN, constructed to study elementary particle interactions in collisions of high-energy proton beams. Twelve different sub detectors as well as the common experimental infrastructure are controlled and monitored by the Detector Control System (DCS) using a highly distributed system of 140 server machines running the industrial SCADA product PVSS. Higher level control system layers allow for automatic control procedures, efficient error recognition and handling, manage the communication with external systems such as the LHC controls, and provide a synchronization mechanism with the ATLAS data acquisition system. Different databases are used to store the online parameters of the experiment, replicate a subset used for physics reconstruction, and store the configuration parameters of the systems. This contribution describes the computing architecture and software tools to handle this complex and highly interconnected control system.Peer Reviewe

System Tests of the ATLAS Pixel Detector

The innermost part of the ATLAS (A Toroidal LHC ApparatuS) experiment at the LHC (Large Hadron Collider) will be a pixel detector, which is presently under construction. Once installed into the experimental area, access will be extremely limited. To ensure that the integrated detector assembly operates as expected, a fraction of the detector which includes the power supplies and monitoring system, the optical readout, and the pixel modules themselves, has been assembled and operated in a laboratory setting for what we refer to as system tests. Results from these tests are presented.Comment: 5 Pages, 9 Figures, to appear in Proceedings of the Eleventh Workshop on Electronics for LHC and Future Experiment

Detector Control System of the ATLAS Insertable B-Layer

soumis à publicationTo improve tracking robustness and precision of the ATLAS inner tracker an additional fourth pixel layer is foreseen, called Insertable B-Layer (IBL). It will be installed between the innermost present Pixel layer and a new smaller beam pipe and is presently under construction. As, once installed into the experiment, no access is available, a highly reliable control system is required. It has to supply the detector with all entities required for operation and protect it at all times. Design constraints are the high power density inside the detector volume, the sensitivity of the sensors against heatups, and the protection of the front end electronics against transients. We present the architecture of the control system with an emphasis on the CO2 cooling system, the power supply system and protection strategies. As we aim for a common operation of pixel and IBL detector, the integration of the IBL control system into the Pixel one will be discussed as well

The Hardware of the ATLAS Pixel Detector Control System

The innermost part of the ATLAS (A Toroidal LHC ApparatuS) experiment will be a pixel detector, built of 1744 individual detector modules. To operate the modules, readout electronics, and other detector components, a complex power supply and control system is necessary. The specific powering and control requirements are described, along with the custom made components of our power supply and control systems. These include remotely programmable Regulator Stations, the power supply system for the optical transceivers, several monitoring units and the Interlock System

Diagnostik arbeitsbedingter Erkrankungen und arbeitsmedizinisch-diagnostische Tabellen

Eine ganze Reihe von beruflichen Belastungen und ungünstigen Arbeitsbedingungen kann zu zahlreichen berufsbedingten Erkrankungen und Beschwerden führen, von denen nur ein kleiner Teil als Berufskrankheit oder Arbeitsunfall anerkannt wird. Der größere, versicherungsrechtlich nicht anerkannte Teil gilt als "arbeitsbedingte Erkrankung" im engeren Sinne. Es sind Erkrankungen und Beschwerden, die beruflich verursacht, teilweise beruflich verursacht oder in ihrer Dynamik beeinflusst werden. Neue Technologien und andere Arbeitsanforderungen führen zu einem geänderten Spektrum und zur Zunahme der arbeitsbedingten Erkrankungen und Beschwerden. Während einzelne Berufskrankheiten aufgrund der Präventionsmaßnahmen seltener geworden sind, verbergen sich viele arbeitsbedingte Erkrankungen im allgemeinen Krankheitsspektrum der Bevölkerung und sind bei der hausärztlichen und klinischen Betreuung zunehmend zu berücksichtigen. Unsere "Diagnostik arbeitsbedingter Erkrankungen und arbeitsmedizinisch-diagnostische Tabellen" gehen einerseits von allgemeinen und speziellen Krankheitsbildern aus und geben eine Übersicht über die möglichen Ursachen. Andererseits werden bestimmte Gefährdungen und die möglichen Beschwerden und Erkrankungen aufgeführt. Bei ausgewählten Erkrankungen werden Hinweise zur spezifischen Diagnostik und Differentialdiagnostik gegeben. Die Darstellungen orientieren sich daher auch am allgemeinen Krankheitsspektrum und sind nicht nur auf die anerkannten Berufskrankheiten eingeengt. Unsere Ausführungen und Tabellen, die in Kooperation mit den jeweiligen Fachvertretern der Medizinischen Fakultät in Homburg erarbeitet wurden, umfassen arbeitsbedingte Atemwegs- und Lungenkrankheiten, Herz- und Kreislaufkrankheiten, Karzinome, Leberkrankheiten, neurologische Krankheiten, Nieren- und Harnwegserkrankungen, ophthalmologische Krankheiten, orthopädisch-chirurgische Erkrankungen der Bewegungsorgane, sensibilisierende Arbeitsstoffe, Virus- und Infektionskrankheiten und verschiedene aktuelle Kurzinformationen. Aufgrund unserer besonderen poliklinischen Tätigkeit haben wir über Jahrzehnte Informationen über arbeitsbedingte Erkrankungen gesammelt und im Jahr 2000 in einer ersten Form zusammen gestellt und im Internet veröffentlicht. Die jetzige Fassung 2007 gehört längst zur Pflichtlektüre für unsere Studierenden und für die Facharztweiterbildung. Die Aktualisierung und Ergänzung ist laufend vorgesehen

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV