Jens Janssen Diploma Thesis - Prof. Dr. Norbert Wermes ...

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Figure 2.5: Cut-away view of the muon spectrometer. The nested structure ofthe tracking chambers minimizes the gaps in detector coverage.2.2.3 The Muon SpectrometerThe muon spectrometer, as shown in figure 2.5, forms the outer part of the AT-LAS detector and is the largest sub-detector in size. The tracking chambers ofthe muon sub-detector detect charged particles that exit the calorimeter. Thisare in most cases muons which live long enough to reach the outer regions ofthe detector. A barrel toroid and the two end-cap toroids generate a largescaletoroidal magnetic field of approximately 0.5T and 1T respectively. Thusmakes it is possible to measure the momentum of charged particles in the pseudorapidityrange of |÷| < 2.7. The transverse momentum (p T ) resolution is ofapproximately 10% for 1TeV particles.In the barrel region, precision-tracking chambers are located on and betweenthe eight coils of the barrel toroid. The nested chambers are arranged in threecylindrical layers at radii of approximately 5, 7.5 and 10 m. In the end-capregion, several muon chambers form large disks. The end-cap disks are locatedin front and behind each end-cap toroid at a distance of 7.4, 10.8, 14 and 21.5mfrom the collision point.The muon spectrometer is essential for the search of new physics. It isdesigned to deliver a fast trigger on particles in the pseudorapidity range of|÷| < 2.4. The trigger occurs if a certain transverse momentum threshold isexceeded.10
Chapter 3Silicon Pixel Detectors3.1 IntroductionThis chapter will give an introduction on the ATLAS pixel vertex detector andthe FE-I3 pixel readout chip (sections 3.2 and 3.3, respectively). The purpose ofa vertex detector is to reconstruct the primary and secondary vertices of hadronscontaining b- and c-quarks. The vertices are reconstructed by extrapolating thehit information measured by several detector layers around the interaction point.The high single point resolution and tracking e ciency of a pixel detector arerequired to obtain better tagging e ciency of the jet flavor. Also, in order tocope with the harsh environment close to the collision point, a pixel detectorhas an advantage of low per-pixel hit occupancy and per-pixel leakage currentand thus noise.In sum, the following criteria must be met by a modern pixel vertex detector:• The innermost vertex layer should be as close to the collision point aspossible to increase the accuracy of the vertex and impact parameter reconstruction.• The detector and its components should be based on a radiation-hardeneddesign.• The material budget (in radiation length) of the detector and its supportingstructures should be as low as possible to reduce the e ect of multiplescattering. This is particularly important for the innermost detector layer.• The pixel detector should have a high spatial resolution in order to providea good hit resolution. Low noise and low hit occupancy are also importantqualities for pattern recognition and for finding primary/secondaryvertices [4] in a high multiplicity environment (e. g. nearby tracks in ajet).• Hermetic coverage over a wide pseudorapidity range.In a second part (section 3.4) and in a more general approach, the e ect of radiationon silicon will be discussed. In section 3.4.1, the interaction of ionizingparticles with the sensor material will be explained and thus the generation ofcharge that is detected as electrical signal. Section 3.4.2 will highlight another11
Page 1: Universität BonnPhysikalisches Ins
Page 7 and 8: Chapter 1IntroductionThe ATLAS expe
Page 9 and 10: Chapter 2The LHC Experiment2.1 The
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Page 17 and 18: Figure 3.2: Layout and interconnect
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that the particles first impinge th
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2. Conversion of (clustered) Time-o
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from the expected charge of 10000 e
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6.2 Unirradiated Planar SensorsThe
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Sensor 3631-303 “ATLAS W11 19GR-2
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(a)(b)(c)Figure 6.4: Planar devices
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6.3.1 Results of the Bias ScanLeaka
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(a)(b)Figure 6.7: Leakage current o
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(a)(b)Figure 6.9: FBK 3D devices: m
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Appendix AFE-I3 StandardConfigurati
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Appendix BFPGA ConfigurationRegiste
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Appendix CTuning ResultsThis page i
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Figure C.1: Tuning of the 3631-303
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8642Figure C.3: Tuning of the WR13
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8642Figure C.5: Tuning of the 4EM9
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[13] Peric, I. et al.: The FEI3 rea
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[37] Backhaus, M. et al.: Developme
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Jens Janssen Diploma Thesis - Prof. Dr. Norbert Wermes ...

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