5,155 research outputs found

    The CMS Outer Tracker Upgrade for the HL-LHC

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    The performance of irradiated CMS silicon mirco-strip detector modules

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    The central tracking system of the Compact Muon Solenoid (CMS) experiment will be entirely buil in silicon technology. The majority of the CMS tracker consists of silicon micro-strip detectors which have to be operated in the harsh environment of the Large Hadron Collider (LHC) over a period of ten years. The expected equivalent fluences range from a low of 0.7 x 10^14 n_1MeV/cm^2 at the outermost layers of the tracker, to a high of 1.6 x 10^14 n_1MeV/cm^2 at the layers closest to the interaction region. In this paper, results from studies of irradiatied CMS silicon detector modules are presented

    P-Type Silicon Strip Sensors for the new CMS Tracker at HL-LHC

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    The upgrade of the LHC to the High-Luminosity LHC (HL-LHC) is expected to increase the LHC design luminosity by an order of magnitude. This will require silicon tracking detectors with a significantly higher radiation hardness. The CMS Tracker Collaboration has conducted an irradiation and measurement campaign to identify suitable silicon sensor materials and strip designs for the future outer tracker at the CMS experiment. Based on these results, the collaboration has chosen to use n-in-p type silicon sensors and focus further investigations on the optimization of that sensor type. This paper describes the main measurement results and conclusions that motivated this decision

    An algorithm for calculating the Lorentz angle in silicon detectors [online]

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    The CMS (Compact Muon Solenoid) detector will use silicon sensors in the harsh radiation environment of the LHC (Large Hadron Collider) and high magnetic fields. The drift direction of the charge carriers is aected by the Lorentz force due to the high magnetic field. Also the resulting radiation damage changes the properties of the drift. The CMS silicon strip detector is read out on the p-side of the sensors, where holes are collected, while the pixel sensors have n-side read out, thus collecting electrons. In this paper measurements of the Lorentz angle are reviewed. Easy algorithms to compute the Lorentz angle are proposed. Key words: silicon, sensors, detectors, Lorentz angle, magnetic field, CM

    Novel P-in-N Si-Sensor technology for high resolution and high repetition-rate experiments at accelerator facilities

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    Linear array detectors with high spatial resolution and MHz frame-rates are essential for high-rate experiments at accelerator facilities. KALYPSO, a line array detector with 1024 pixels operating over 1 Mfps has been developed. To improve the spatial resolution and sensitivity at different wavelengths, novel p-in-n Si microstrip sensors based on have been developed with a pitch of 25 micrometer. The efficiency of the sensor has been improved with the use of anti reflecting coating layers optimized for near infrared, visible and near ultraviolet. In this contribution the detector system and the sensors will be presented

    Lorentz angle measurements in irradiated silicon detectors between 77 K and 300 K

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    Future experiments are using silicon detectors in a high radiation environment and in high magnetic fields. The radiation tolerance of silicon improves by cooling it to temperatures below 180 K. At low temperatures the mobility increases, which leads to larger de of the charge carriers by the Lorentz force. A good knowledge of the Lorentz angle is needed for design and operation of silicon detectors. We present measurements of the Lorentz angle between 77 K and 300 K before and after irradiation with a primary beam of 21 MeV protons

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV