| 21. |
- Esebamen, Omeime, et al.
(author)
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Surface State Effects on N+P Doped Electron Detector
- 2011
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In: Journal of Instrumentation. - 1748-0221 .- 1748-0221. ; 6:12, s. Art. no. C12019-
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Journal article (peer-reviewed)abstract
- Surface states and interface recombination velocity that exist between detector interfaces have always been known to affect the performance of a detector. This article describes how the detector performance varies when the doping profile is altered. When irradiated with electrons, the results show that while changes in the doping profile have an effect of the detector responsivity with respect to the interface recombination velocityVs, there is no visible effect with respect tofixed oxide chargeQfotherwise known as interface fixed charge density.
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| 22. |
- Norlin, Börje, et al.
(author)
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Readout cross-talk for alpha-particle measurements in a pixelated sensor system
- 2015
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In: Journal of Instrumentation. - : IOP. - 1748-0221 .- 1748-0221. ; 10
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Journal article (peer-reviewed)abstract
- Simulations in Medici are performed to quantify crosstalk and charge sharing in a hybrid pixelated silicon detector. Crosstalk and charge sharing degrades the spatial and spectral resolution of single photon processing X-ray imaging systems. For typical medical X-ray imaging applications, the process is dominated by charge sharing between the pixels in the sensor. For heavier particles each impact generates a large amount of charge and the simulation seems to over predict the charge collection efficiency. This indicates that some type of non modelled degradation of the charge transport efficiency exists, like the plasma effect where the plasma might shield the generated charges from the electric field and hence distorts the charge transport process. Based on the simulations it can be reasoned that saturation of the amplifiers in the Timepix system might generate crosstalk that increases the charge spread measured from ion impact on the sensor.
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| 23. |
- Aad, G, et al.
(author)
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Performance of b-jet identification in the ATLAS experiment
- 2016
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In: Journal of Instrumentation. - : Institute of Physics (IOP). - 1748-0221. ; 11:4
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Journal article (peer-reviewed)abstract
- The identification of jets containing b hadrons is important for the physics programme of the ATLAS experiment at the Large Hadron Collider. Several algorithms to identify jets containing b hadrons are described, ranging from those based on the reconstruction of an inclusive secondary vertex or the presence of tracks with large impact parameters to combined tagging algorithms making use of multi-variate discriminants. An independent b-tagging algorithm based on the reconstruction of muons inside jets as well as the b-tagging algorithm used in the online trigger are also presented. The b-jet tagging efficiency, the c-jet tagging efficiency and the mistag rate for light flavour jets in data have been measured with a number of complementary methods. The calibration results are presented as scale factors defined as the ratio of the efficiency (or mistag rate) in data to that in simulation. In the case of b jets, where more than one calibration method exists, the results from the various analyses have been combined taking into account the statistical correlation as well as the correlation of the sources of systematic uncertainty. © CERN 2016 for the benefit of the ATLAS collaboration, published under the terms of the Creative Commons Attribution 3.0 License by IOP Publishing Ltd and Sissa Medialab srl.
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| 24. |
- Milstead, David A., et al.
(author)
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Study of the material of the ATLAS inner detector for Run 2 of the LHC
- 2017
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In: Journal of Instrumentation. - : Institute of Physics (IOP). - 1748-0221. ; 12:12
-
Journal article (peer-reviewed)abstract
- The ATLAS inner detector comprises three different sub-detectors: the pixel detector, the silicon strip tracker, and the transition-radiation drift-tube tracker. The Insertable B-Layer, a new innermost pixel layer, was installed during the shutdown period in 2014, together with modifications to the layout of the cables and support structures of the existing pixel detector. The material in the inner detector is studied with several methods, using a low-luminosity s=13 TeV pp collision sample corresponding to around 2.0 nb-1 collected in 2015 with the ATLAS experiment at the LHC. In this paper, the material within the innermost barrel region is studied using reconstructed hadronic interaction and photon conversion vertices. For the forward rapidity region, the material is probed by a measurement of the efficiency with which single tracks reconstructed from pixel detector hits alone can be extended with hits on the track in the strip layers. The results of these studies have been taken into account in an improved description of the material in the ATLAS inner detector simulation, resulting in a reduction in the uncertainties associated with the charged-particle reconstruction efficiency determined from simulation. © 2017 CERN.
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| 25. |
- Aad, G, et al.
(author)
-
Electron and photon energy calibration with the ATLAS detector using LHC Run 2 data
- 2024
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In: Journal of Instrumentation. - : Institute of Physics. - 1748-0221. ; 19:2
-
Journal article (peer-reviewed)abstract
- This paper presents the electron and photon energy calibration obtained with the ATLAS detector using 140 fb−1 of LHC proton-proton collision data recorded at √s = 13 TeV between 2015 and 2018. Methods for the measurement of electron and photon energies are outlined, along with the current knowledge of the passive material in front of the ATLAS electromagnetic calorimeter. The energy calibration steps are discussed in detail, with emphasis on the improvements introduced in this paper. The absolute energy scale is set using a large sample of Z-boson decays into electron-positron pairs, and its residual dependence on the electron energy is used for the first time to further constrain systematic uncertainties. The achieved calibration uncertainties are typically 0.05% for electrons from resonant Z-boson decays, 0.4% at ET ∼ 10 GeV, and 0.3% at ET ∼ 1 TeV; for photons at ET ∼ 60 GeV, they are 0.2% on average. This is more than twice as precise as the previous calibration. The new energy calibration is validated using J/ → ee and radiative Z-boson decays. © 2024 Institute of Physics. All rights reserved.
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| 26. |
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| 27. |
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| 28. |
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| 29. |
- Aad, G., et al.
(author)
-
The ATLAS Experiment at the CERN Large Hadron Collider
- 2008
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In: Journal of Instrumentation. - 1748-0221. ; 3:S08003
-
Research review (peer-reviewed)abstract
- The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.
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| 30. |
- Aaij, R., et al.
(author)
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Curvature-bias corrections using a pseudomass method
- 2024
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In: Journal of Instrumentation. - 1748-0221. ; 19:3
-
Journal article (peer-reviewed)abstract
- Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √s = 13 TeV during 2016, 2017 and 2018. The biases are determined using Z → μ+μ- decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z → μ+μ- mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass. © 2024 CERN.
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