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- Aad, G., et al.
(författare)
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Commissioning of the ATLAS Muon Spectrometer with cosmic rays
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:3, s. 875-916
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Tidskriftsartikel (refereegranskat)abstract
- The ATLAS detector at the Large Hadron Collider has collected several hundred million cosmic ray events during 2008 and 2009. These data were used to commission the Muon Spectrometer and to study the performance of the trigger and tracking chambers, their alignment, the detector control system, the data acquisition and the analysis programs. We present the performance in the relevant parameters that determine the quality of the muon measurement. We discuss the single element efficiency, resolution and noise rates, the calibration method of the detector response and of the alignment system, the track reconstruction efficiency and the momentum measurement. The results show that the detector is close to the design performance and that the Muon Spectrometer is ready to detect muons produced in high energy proton-proton collisions.
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- Aad, G., et al.
(författare)
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Readiness of the ATLAS Tile Calorimeter for LHC collisions
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:4, s. 1193-1236
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Tidskriftsartikel (refereegranskat)abstract
- The Tile hadronic calorimeter of the ATLAS detector has undergone extensive testing in the experimental hall since its installation in late 2005. The readout, control and calibration systems have been fully operational since 2007 and the detector has successfully collected data from the LHC single beams in 2008 and first collisions in 2009. This paper gives an overview of the Tile Calorimeter performance as measured using random triggers, calibration data, data from cosmic ray muons and single beam data. The detector operation status, noise characteristics and performance of the calibration systems are presented, as well as the validation of the timing and energy calibration carried out with minimum ionising cosmic ray muons data. The calibration systems' precision is well below the design value of 1%. The determination of the global energy scale was performed with an uncertainty of 4%.
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- Aad, G., et al.
(författare)
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Studies of the performance of the ATLAS detector using cosmic-ray muons
- 2011
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 71:3
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Tidskriftsartikel (refereegranskat)abstract
- Muons from cosmic-ray interactions in the atmosphere provide a high-statistics source of particles that can be used to study the performance and calibration of the ATLAS detector. Cosmic-ray muons can penetrate to the cavern and deposit energy in all detector subsystems. Such events have played an important role in the commissioning of the detector since the start of the installation phase in 2005 and were particularly important for understanding the detector performance in the time prior to the arrival of the first LHC beams. Global cosmic-ray runs were undertaken in both 2008 and 2009 and these data have been used through to the early phases of collision data-taking as a tool for calibration, alignment and detector monitoring. These large datasets have also been used for detector performance studies, including investigations that rely on the combined performance of different subsystems. This paper presents the results of performance studies related to combined tracking, lepton identification and the reconstruction of jets and missing transverse energy. Results are compared to expectations based on a cosmic-ray event generator and a full simulation of the detector response.
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- Aad, G., et al.
(författare)
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The ATLAS Inner Detector commissioning and calibration
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:3, s. 787-821
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Tidskriftsartikel (refereegranskat)abstract
- The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data-taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and in-situ calibrations are described. Tracking performance has been measured with 7.6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes, specific energy-loss calibration and transition radiation turn-on measurements have been performed. Different alignment techniques have been used to reconstruct the detector geometry. After the initial alignment, a transverse impact parameter resolution of 22.1 +/- 0.9 mu m and a relative momentum resolution sigma (p) /p=(4.83 +/- 0.16)x10(-4) GeV(-1)xp (T) have been measured for high momentum tracks.
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- Aad, G., et al.
(författare)
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The ATLAS Simulation Infrastructure
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:3, s. 823-874
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Tidskriftsartikel (refereegranskat)abstract
- The simulation software for the ATLAS Experiment at the Large Hadron Collider is being used for large-scale production of events on the LHC Computing Grid. This simulation requires many components, from the generators that simulate particle collisions, through packages simulating the response of the various detectors and triggers. All of these components come together under the ATLAS simulation infrastructure. In this paper, that infrastructure is discussed, including that supporting the detector description, interfacing the event generation, and combining the GEANT4 simulation of the response of the individual detectors. Also described are the tools allowing the software validation, performance testing, and the validation of the simulated output against known physics processes.
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- Breugem, Corstiaan, et al.
(författare)
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Prioritizing Cleft/Craniofacial Surgical Care after the COVID-19 Pandemic
- 2020
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Ingår i: PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN. - 2169-7574. ; 8:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is anticipated that in due course the burden of emergency care due to COVID-19 infected patients will reduce sufficiently to permit elective surgical procedures to recommence. Prioritizing cleft/craniofacial surgery in the already overloaded medical system will then become an issue. The European Cleft Palate Craniofacial Association, together with the European Cleft and Craniofacial Initiative for Equality in Care, performed a brief survey to capture a current snapshot during a rapidly evolving pandemic. Methods: A questionnaire was sent to the 2242 participants who attended 1 of 3 recent international cleft/craniofacial meetings. Results: The respondents indicated that children with Robin sequence who were not responding to nonsurgical options should be treated as emergency cases. Over 70% of the respondents indicated that palate repair should be performed before the age of 15 months, an additional 22% stating the same be performed by 18 months. Placement of middle ear tubes, primary cleft lip surgery, alveolar bone grafting, and velopharyngeal insufficiency surgery also need prioritization. Children with craniofacial conditions such as craniosynostosis and increased intracranial pressure need immediate care, whilst children with craniosynostosis and associated obstructive sleep apnea syndrome or proptosis need surgical care within 3 months of the typical timing. Craniosynostosis without signs of increased intracranial pressure needs correction before the age of 18 months. Conclusions: This survey indicates several areas of cleft and craniofacial conditions that need prioritization, but also certain areas where intervention is less urgent. We acknowledge that there will be differences in the post COVID-19 response according to circumstances and policies in individual countries.
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- Breugem, Corstiaan, et al.
(författare)
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Prioritizing Cleft/Craniofacial Surgical Care after the COVID-19 Pandemic
- 2020
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Ingår i: PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN. - 2169-7574. ; 8:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is anticipated that in due course the burden of emergency care due to COVID-19 infected patients will reduce sufficiently to permit elective surgical procedures to recommence. Prioritizing cleft/craniofacial surgery in the already overloaded medical system will then become an issue. The European Cleft Palate Craniofacial Association, together with the European Cleft and Craniofacial Initiative for Equality in Care, performed a brief survey to capture a current snapshot during a rapidly evolving pandemic. Methods: A questionnaire was sent to the 2242 participants who attended 1 of 3 recent international cleft/craniofacial meetings. Results: The respondents indicated that children with Robin sequence who were not responding to nonsurgical options should be treated as emergency cases. Over 70% of the respondents indicated that palate repair should be performed before the age of 15 months, an additional 22% stating the same be performed by 18 months. Placement of middle ear tubes, primary cleft lipsurgery, alveolar bone grafting, and velopharyngeal insufficiency surgery also need prioritization. Children with craniofacial conditions such as craniosynostosis and increased intracranial pressure need immediate care, whilst children with craniosynostosis and associated obstructive sleep apnea syndrome or proptosis need surgical care within 3 months of the typical timing. Craniosynostosis without signs of increased intracranial pressure needs correction before the age of 18 months. Conclusions: This survey indicates several areas of cleft and craniofacial conditions that need prioritization, but also certain areas where intervention is less urgent. We acknowledge that there will be differences in the post COVID-19 response according to circumstances and policies in individual countries.
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