Alignment of the ALICE Inner Tracking System with cosmic-ray tracks

37 pages, 15 figures, revised version, accepted by JINSTALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.Peer reviewe

The ALICE experiment at the CERN LHC

ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 161626 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008

The new design and technological solutions for the led modules for retrofit lamps

The authors propose fundamentally new design-technological solutions for compact volumetric mirrorized LED modules with increased power. Test samples of volumetric light-effective LED light effective modules with a power of 10-15 W and light output of 105-160 lm/W for domestic retrofit lamps based on high-efficiency SMD, mini COB, and COB LEDs of third generation were ma­nu­fac­tu­red and tested. Positive technical and practical results were obtained by increasing by over 4-6 times the size of holders - heat sinks (compared to LED modules of flat holders) for heat dissipation from the LEDs by conduction and heat radiation, as well as by increasing light efficiency of LED lamps due to the additional light re-reflection by mirrorized reflectors-radiators in the bulb which is diffuser of the lamp light

Alice Silicon Strip Detector Module Assembly with Single-Point TAB Interconnections

35nonenoneM.OINONEN; J.AALTONEN; I.KASSAMAKOV; S.NIKKINEN; Z.RADIVOJEVIC; H.SEPPÄNEN; M.ÖSTERBERG; V.BORSHCHOV; A.LISTRATENKO; V.ANTONOVA; I.TYMCHUK; M.PROTSENKO; J.KOSTYSHIN; G.ZINOVJEV; A.P.DE HAAS; P.G.KUIJER; G.J.L.NOOREN; C.J.OSKAMP; A.N.SOKOLOV; A.VAN DEN BRINK; F. AGNESE; D.BONNET; O.CLAUSSE; M.IMHOFF; C.KUHN; J.R.LUTZ; M.H.SIGWARD; M.BREGANT; L.BOSISIO; P.CAMERINI; G.CONTIN; N.GRION; F.FALESCHINI; MARGAGLIOTTI G.V.; O.BORYSOVOinonen, M.; Aaltonen, J.; Kassamakov, I.; Nikkinen, S.; Radivojevic, Z.; Seppänen, H.; Österberg, M.; Borshchov, V.; Listratenko, A.; Antonova, V.; Tymchuk, I.; Protsenko, M.; Kostyshin, J.; Zinovjev, G.; DE HAAS, A. P.; Kuijer, P. G.; Nooren, G. J. L.; Oskamp, C. J.; Sokolov, A. N.; VAN DEN BRINK, A.; Agnese, F.; Bonnet, D.; Clausse, O.; Imhoff, M.; Kuhn, C.; Lutz, J. R.; Sigward, M. H.; Bregant, M.; Bosisio, L.; Camerini, Paolo; Contin, G.; Grion, N.; Faleschini, F.; Margagliotti, Giacomo; Borysov, O

The ALICE vertex detector: Focus on the micro-strip layers

The ALICE experiment, which is being installed at the Large Hadron Collider at CERN, is designed to operate in a high-track density environment which is typical of relativistic heavy ions physics. This paper reports the main characteristics of the Inner Tracking System (ITS) of ALICE and describes the Silicon Strip Detector, which forms the two outermost layers of the IT

Assembly and validation of the ALICE silicon microstrip detector

The two outermost layers of the ALICE Inner Tracking System consist of 1698 double-sided silicon microstrip modules, which form the Silicon Strip Detector (SSD). The SSD modules offer several novelties, which include the use of TAB-bonding technique for the connection of the front-end electronic via thin aluminium-polyimide cables. The module as well as its parts will be described and the assembling procedure illustrated

The ALICE vertex detector: Focus on the micro-strip layers

The ALICE microstrip detector of the Inner Tracking Syste

Assembly and validation of the SSD silicon microstrip detector of ALICE

The Silicon Strip Detector (SSD) forms the two outermost layers of the Inner Tracking System (ITS) of ALICE. The SSD detector consists of 1698 double-sided silicon microstrip modules. The electrical connection between silicon sensor and front-end electronics is made via TAB-bonded aluminium polyimide cables (chip-cables). The module assembly is challenging because of the module geometry and the use of chip-cables. This article describes the assembly procedure and the test protocol used