Hugging, Fabian Nucl. Instrum. Methods Phys. Res., A 10.1016/j.nima.2005.04.045 157-164 549 2005 2005 For the ATLAS Pixel Detector fast readout electronics has been successfully developed and tested. Main attention was given to the ability to detect small charges in the order of 5,000 electrons within 25 ns in the harsh radiation environment of LHC together with the challenge to cope with the huge amount of data generated by the 80 millions channels of the Pixel detector. For the integration of the 50 micron pitch hybrid pixel detector reliable bump bonding techniques using either lead-tin or indium bumps has been developed and has been successfully tested for large scale production. Frys, M Kapsia, S Spetik, Z Sezam, T Radhostem, R P Jurka, V Vrba, V pixel detectors Tesla SEZAM ATLAS experiment sensor design sensor processing electrical characteristics Si 2002 2002 Tesla SEZAM is one of the producers of pixel detectors for the ATLAS experiment at CERN. In the present paper specific design features of sensors and basic processing steps for the manufacturing of sensor structures are described. Electrical characteristics illustrating the quality of produced sensors are presented. (14 refs). Grosse-Knetter, Jorn Nucl. Instrum. Methods Phys. Res., A 10.1016/j.nima.2005.04.028 70-74 549 2005 2006 The ATLAS Pixel Detector is the innermost layer of the ATLAS tracking system and will contribute significantly to the ATLAS track and vertex reconstruction. The detector consists of identical sensor-chip-hybrid modules, arranged in three barrels in the centre and three disks on either side for the forward region. The position of the Pixel Detector near the interaction point requires excellent radiation hardness, mechanical and thermal robustness, good long-term stability, all combined with a low material budget. The detector layout, results from final prototyping and the status of production are presented. Santi, L Cobal, M Morettini, P Schiavi, C monitoring online pixel detector 2003 2003 This note describes the Pixel detector on-line monitoring program to be used in system tests. Both the program and the GUI have been written in C++ and allow visualizing in real time pedestals, and signals. The program also displays occupancy and hit multiplicity distributions as online histograms. Speer, T Nucl. Phys. B, Proc. Suppl. 10.1016/S0920-5632(02)02009-1 318 115 TRACKING 2003 2003 An overview of the tracking detectors of the ATLAS and CMS experiments at the LHC is presented. The ATLAS tracking system is composed of a pixel detector, a silicon micro-strip tracker and a straw tube transition radiation tracker. The CMS tracking system features an all-silicon layout consisting of a pixel detector and a silicon micro-strip tracker. These detectors are designed to operate with a 40 MHz bunch crossing frequency in a high particle flux density and extreme radiation environment. Alam, M Bonzom, V Brandl, A D'Auria, S Delpierre, P A Einsweiler, K F Gilchriese, M G D Gorfine, G Holland, S Hügging, F G Lutz, Gerhard Richter, R Rohe, T Rossi, L Seidel, S Sícho, P Skubic, P L Vrba, V Wunstorf, R 1997 1997 Osculati, B Barberis, D 1997 1997 Bintinger, D L Emes, J Gilchriese, M G D Lafever, RA Truong, T 1996 1996 Bintinger, D L Emes,J Gilchriese, M G D Lafever, RA Miller, W Truong, T 1996 1996 Gorfine, G Holland, S Seidel, S 1996 1996 Desch, Klaus Fischer, P Wermes, N 1996 1996 Bintinger, D L Delpierre, P A Einsweiler, K F Fallou, A Gilchriese, M G D Hallewell, G D Mouthuy, T 1994 1994 Fischer, P Raith, B Wermes, N Lankford, A Pier, S Schmid, B Campbell, M Jarron, P Heijne, Erik H M Middelkamp, P Snoeys, W Arrighi, C Blanquart, L Bonzom, V Clemens, J-C Cohen-Solal, M Delpierre, P A Fallou, A Grigoriev, E Habrard, M C Hallewell, G D Labat, D López, L Mekkaoui, A Mouthuy, T Potheau, R Raymond, M Rozanov, A Sauvage, D Vacavant, L Bintinger, D L Ciocio, A Einsweiler, K F Gilchriese, M G D Milgrome, O Millaud, J E Nygren, D R Shapiro, M Siegrist, J L Spieler, H Wright, M Capannesi, G Colucci, M Pelfer, Pier Giovanni Sottini, S Barberis, D Bozzo, M Caso, Carlo Dameri, M Darbo, G Morettini, P Musico, P Osculati, B Rossi, L Sette, G Bates, R D'Auria, S Gowdy, S O'Shea, V Raine, C Smith, KM Bellini, G Di Corato, M D'Avella, A Inzani, P Menasce, D Moroni, L Pedrini, D Perasso, L Ragusa, F Sala, S Tartarelli, F Cesura, G Hauff, D Hörnl, H Kemmer, J Lechner, P Lutz, Gerhard Richter, R H Seitz, H Gao, Y Harton, J Jared, R Walsh, M Wu, S Becks, K H Glitza, WK Heuser, J M Kersten, S 1994 1994 Fallou, A Hallewell, G D Labat, D 1994 1994 Hallewell, G D 1994 1994 Kostyukhin, V Lévêque, J Rozanov, A De Vivie de Régie, J B Higgs b-tagging light jet rejection longitudinal pitch pixel 2003 2003 The b-tagging performance of the ATLAS Inner Detector with 400 microns longitudinal pixel pitch in the b-layer is compared with that of the default DC0/DC1 layout with b-layer pixel pitch of 300 microns. This study is intended to be the simulation backup document for the corresponding Engineering Change Request. Alimonti, G Andreazza, A Citterio, M Lari, T Meroni, C Ragusa, F Troncon, C pixel radiation damage silicon testbeam trapping 2003 2003 This note describes an original method which has been developed to determine the trapping time constants in irradiated silicon using the data of the ATLAS Pixel Detector test beams. The charge collection efficiency is measured as a function of the drift length in irradiated silicon, and the charge carrier trapping lifetime is extracted comparing the data with a numerical simulation of the detector response to ionizing particles. The measurements have been performed on pixel detectors irradiated with protons to a fluence of $1.1 \cdot 10^{15}$~\nequ. A trapping lifetime of ($2.3 \pm 0.8$)~ns is found after annealing to minimum in full depletion voltage, while it is $(4.1 \pm 0.7)$~ns after 25~h annealing at 60~$^0$C. Comparison with measurements made with the transient current technique is discussed. Lari, T Geant4 pixel radiation damage simulation 2003 2003 This note presents a numerical simulation of the response of irradiated and not irradiated silicon pixel detectors to ionizing particles. The simulation was developed as a stand-alone Geant4 application with the goal of understanding the response of a detector using a detailed description of the charge drift and signal induction processes. The radiation damage is simulated through the modifications it induces on the thickness of the active region, the electric field strength and distribution inside the sensor, and the charge trapping probability. This approach is different from those used in the simulations developed in the more general framework of the ATLAS detector simulation, which is subjected to severe CPU and memory usage constraints and can not afford the detailed description of charge drift and signal induction processes described here. The simulation strategy is described in detail. The simulated detector response before and after radiation damage is presented and it is compared with data taken at the test beam. Andreazza, A Lari, T Meroni, C Ragusa, F Troncon, C Analysis Pixel detector Test beam User Guide 2003 2003 This note describes the use of the program h8 developed for the analysis of test beam data by the Atlas Pixel group. The program has been already used for several years of interesting and successful analyses. Haywood, S Alignment Overlap Pixels SCT 2002 2002 This short note summarises extent of the overlaps in the Barrels and Wheels of the SCT and Pixel silicon trackers. Calvet, D Fornaini, A Gadomski, S PixelModuleDesign SCT_ModuleSideDesign SiDetectorDesign SiDetectorElement SiTrackerDetDescr 2002 2002 This note describes the new transient detector description model of the two Atlas silicon trackers: the Pixel and the SCT detectors, as it will be used for Data Challenge 0. Barberis, D Cervetto, M Osculati, B Geant4 Hadronic Physics Pixels 2002 2002 Hadronic interactions produced by 180 GeV pions in the silicon sensors of the ATLAS Pixel detectors are compared to events produced by Geant4 with the parametric (Gheisa) and with the theoretical (Quark-Gluon String) Physics models. Beccherle, R Blanquart, L Boyd, R Calvet, D Comes, G Darbo, G Einsweiler, K F Fischer, P Gagliardi, G Gemme, C Meddeler, G Morettini, P Musico, P Osculati, B Oppizzi, P Pratolongo, F Richardson, J Ruscino, E Schiavi, C Sícho, P Vernocchi, F Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(02)01279-2 117-133 492 ATLAS Module Controller Chip Pixel Detector rad-hard read-out 2002 2002 In this article we describe the architecture of the Module Controller Chip for the ATLAS Pixel Detector. The project started in 1997 with the definition of the system specifications. A first fully-working rad-soft prototype was designed in 1998, while a radiation hard version was submitted in 2000. The 1998 version was used to build pixel detector modules. Results from those modules and from the simulated performance in ATLAS are reported. In the article we also describe the hardware/software tools developed to test the MCC performance at the LHC event rate. Calvet, D Digits EDM Pixel SCT 2002 2002 This note describes the new Event Data Model of the two Atlas silicon trackers, the Pixel detector and the SCT, as it is available in the Data Challenge 0 software (release 3.0.0). Gorelov, I Gorfine, G Hoeferkamp, M Mata-Bruni, V Santistevan, G Seidel, S C Ciocio, A Einsweiler, K F Emes, J Gilchriese, M G D Joshi, A Kleinfelder, S A Marchesini, R McCormack, F Milgrome, O Palaio, N Pengg, F Richardson, J Zizka, G Ackers, M Comes, G Fischer, P Keil, M Klasen, V Kühl, T Meuser, S Ockenfels, W Raith, B Treis, J Wermes, N Gössling, C Hügging, F G Klaiber Lodewigs, Jonas M Krasel, O Wüstenfeld, J Wunstorf, R Barberis, D Beccherle, R Caso, Carlo Cervetto, M Darbo, G Gagliardi, G Gemme, C Morettini, P Netchaeva, P Osculati, B Rossi, L Charles, E Fasching, D Blanquart, L Breugnon, P Calvet, D Clemens, J-C Delpierre, P A Hallewell, G D Laugier, D Mouthuy, T Rozanov, A Valin, I Andreazza, A Caccia, M Citterio, M Lari, T Meroni, C Ragusa, F Troncon, C Vegni, G Lutz, Gerhard Richter, R H Rohe, T Boyd, GR Skubic, P L Sícho, P Tomasek, L Vrba, V Holder, M Ziolkowski, M Cauz, D Cobal-Grassmann, M D'Auria, S De Lotto, B del Papa, C Grassmann, H Santi, L Becks, K H Lenzen, G Linder, C pixel sensors silicon 2001 2001 Prototype sensors for the ATLAS silicon pixel detector have been electrically characterized. The current and voltage characteristics, charge collection efficiencies, and resolutions have been examined. Devices were fabricated on oxygenated and standard detector-grade silicon wafers. Results from prototypes which examine p-stop and standard and moderated p-spray isolation are presented for a variety of geometrical options. Some of the comparisons relate unirradiated sensors with those that have received fluences relevant to LHC operation. Gilchriese, M G D Johnson, T McCormack, F Weber, T Wirth, J Wise, W disk sectors pixels thermal qualification 2001 2001 The thermal qualification tests for the ATLAS Pixel Detector disk sector prototypes are described. Recent measurements on prototypes are presented. Calvet, D Digitization Pixel SCT 2001 2001 This note describes the common framework which has been developed for the digitization of the two Atlas silicon trackers, the Pixel detector and the SCT. Lari, T Lorentz angle alignment bias voltage mobility silicon spatial resolution 2001 2001 The material reported in this note has been presented at the Inner Detector general meeting during the February 2001 ATLAS week. Author from INFN and University of Milan. Lorentz angle in silicon detectors is computed from drift properties of charge carriers. It is found to be a strongly varying function of electric field. From this model, the Lorentz angle for ATLAS silicon detectors (SCT and Pixel) is computed. It results to be a function of applied bias and sensor thickness. Some considerations are made about the effect of Lorentz angle variation on spatial resolution and alignment. Lari, T Alignment Pixel sensors depletion irradiated 2001 2001 The procedures used to align pixel detectors in test beam operation are presented. Some sensors irradiated up to 10^15 n_eq cm^-2 fluence were operated in partial depletion mode. The effect of a depletion not equal to nominal thickness on the alignment is discussed. An alignment procedure based on the charge collected by the first pixel in clusters has been developed to allow precise measurement of depletion depth. Gadomski, S vertex performance tracker 2000 2000 The layout of the ATLAS pixel system has changed twice since the physics TDR was published. This note presents updated impact parameter resolutions calculated using a simple program that models geometry, detector resolutions and multiple scattering. The results can be used for physics simulations using parameterised tracker resolutions. Baratella, A Morettini, P Parodi, F Level 2 Trigger b-tagging 2000 2000 This note describes an algorithm for the identification of b-jets at Level 2. The aim of this trigger is to increase the acceptancefor multi b-jets events keeping the same rate as the one given by the present trigger in Et.A simple algorithm based on pixel detector has been shown to achieve rejection factors of about 10-20 for 50% efficiency with processing time well below the LVL2 latency. Baratella, A Dameri, M Morettini, P Parodi, F Level 2 Trigger Track search 2000 2000 This note describes an algorithm for track search at Level 2 based on pixel detector. Using three pixel clusters we can produce a reconstruction of the track parameter in both z and R-phi plane. These track segments can be used as seed for more sophisticated track finding algorithms or used directly, especially when impact parameter resolution is crucial. The algorithm efficiency is close to 90% for pt > 1 GeV/c and the processing time is small enough to allow a complete detector reconstruction (non RoI guided) within the Level 2 processing. Dawson, I 2000 2000 The radiation environment in the inner detector has been simulated using the particle transport program FLUKA with a recent description of the ATLAS experiment. Given in this note are particle fluences and doses at positions relevant to the PIXEL, SCT and TRT detectors. In addition, studies are reported on in which 1) information concerning the optimisation of the inner detector neutron-moderators is obtained and 2) the impact of including additional vacuum-equipment is assessed. Olcese, M Grohmann, S C3F8 cooling evaporative fault analysis 1999 1999 The conceptual design of an evaporative cooling system for the ATLAS Pixel detector, using C3F8 as coolant, is described.The main elements and components of the system are discussed and a detailed safety analysis is presented.The proposed local condenser concept shows interesting advantages with respect to the compressor-based systems mainly because it implements standard, simple and reliable technologies. electronics pixel 1999 1999 results. Alam, M S Ciocio, A Einsweiler, K F Emes, J Gilchriese, M G D Joshi, A Kleinfelder, S A Marchesini, R McCormack, F Milgrome, O Palaio, N Pengg, F Richardson, J Zizka, G Ackers, M Andreazza, A Comes, G Fischer, P Keil, M Klasen, V Kühl, T Meuser, S Ockenfels, W Raith, B Treis, J Wermes, N Gössling, C Hügging, F G Wüstenfeld, J Wunstorf, R Barberis, D Beccherle, R Darbo, G Gagliardi, G Gemme, C Morettini, P Musico, P Osculati, B Parodi, F Rossi, L Blanquart, L Breugnon, P Calvet, D Clemens, J-C Delpierre, P A Hallewell, G D Laugier, D Mouthuy, T Rozanov, A Valin, I Aleppo, M Caccia, M Ragusa, F Troncon, C Lutz, Gerhard Richter, R H Rohe, T Brandl, A Gorfine, G Hoeferkamp, M Seidel, SC Boyd, GR Skubic, P L Sícho, P Tomasek, L Vrba, V Holder, M Ziolkowski, M D'Auria, S del Papa, C Charles, E Fasching, D Becks, K H Lenzen, G Linder, C Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(00)00574-X 217-232 456 16 Pixel Sensors Silicon 2001 2001 Prototype sensors for the ATLAS silicon pixel detector have been developed. The design of the sensors is guided by the need to operate them in the severe LHC radiation environment at up to several hundred volts while maintaining a good signal-to-noise ratio, small cell size, and minimal multiple scattering. The ability to be operated under full bias for electrical characterization prior to the attachment of the readout integrated circuit electronics is also desired. Pixel ROB SCT 1999 1999 A simple object-oriented program has been written to simulate the SCT and Pixel detectors in order to determine the suitability of various ROB mapping schemes in the context of the Level 2 trigger. Layer and tower mappings have been investigated separately for the SCT barrel and endcap and for the Pixel barrel and endcap. Events containing one RoI were fired at each detector part and the number of ROBs hit determined. As a result, plots of ROB output data rates and ROB hit frequency as a function of ROB ID were obtained. In general it was found that layer mapping schemes might result in unacceptably high data rates and frequencies. This result would have to be confirmed with more detailed modelling. The tower mappings investigated, in general produced acceptable rates. Sícho, P 1997 1997 Rozanov, A simulation PIXEL 1998 1998 Parker, A Edwards, M Hajduk, Z Froidevaux, D Gichriese, G Hallewell, G D Pater, J R 1998 1998 The evolution of the material budget of the ATLAS Inner Detector between the time of the Technical Design Report and the Pixel Technical Design Report is described in detail. Possibilities for furt her optimisation are considered. Ferro, F inner pixel primary vertex secondary vertex tagging tau vertexing 2003 2003 A package for the vertex reconstruction (Vertexing) has been developed in the ATLAS offline software. It consists of an Object Oriented interface to an existing fitting routine and of a set of test algorithms. The code is described in the first part of this note. In the second part, the Vertexing algorithms are applied to the identification of the hadronic tau decays. A 44.1% efficiency has been achieved in A -> tau tau -> hadrons (mA = 800 GeV/c^2) events. The jet-rejection has also been estimated in QCD events with high-pT jets. Vacek, V Hallewell, G D Ilie, S Lindsay, S Fluid Phase Equilib. 10.1016/S0378-3812(00)00426-X 191-201 174 Alternative refrigerants Cooling Systems Mixtures Perfluoro-carbons Semiconductor Particle Detectors 2000 2000 We report on the development of evaporative fluorocarbon cooling for the semiconductor pixel and micro-strip sensors of inner tracking detector of the ATLAS experiment at the future CERN Large Hadron Collider (LHC). We proceeded with studies using perfluoro-n-propane (3M-"PFG 5030"; C3F8), perfluoro-n-butane (3M-"PFG 5040"; C4F10), trifluoro-iodo-methane (CF3I) and custom C3F8/C4F10 mixtures. Certain thermo-physical properties had to be verified for these fluids. Di Girolamo, B. 200309 Netchaeva, P 2002 2002 The ATLAS pixel detector is based on a set of radiation-hard electronics chips able to resist a dose of 500 kGy. The implementation of these chips in the DMILL technology did not give the expected results. Re-design of the radiation-hard chips in Deep SubMicron technology is ongoing, but has implied a one and a half year delay in an already tight schedule. Major layout changes have therefore been necessary to allow installation of the ATLAS pixel detector at LHC start-up. This paper illustrates the status of the ATLAS pixel project, die motivations for the new layout, the way this should be implemented and the prototype fabrication and testing. (4 refs). Grosse-Knetter, Jorn eConf FRAP17 C030626 2003 2003 The ATLAS Pixel Detector is the innermost layer of the ATLAS tracking system and will contribute significantly to the ATLAS track and vertex reconstruction. The detector consists of identical sensor-chip-hybrid modules, arranged in three barrels in the centre and three disks on either side for the forward region. The position of the pixel detector near the interaction point requires excellent radiation hardness, mechanical and thermal robustness, good long-term stability, all combined with a low material budget. The pre-production phase of such pixel modules has nearly finished, yielding fully functional modules. Results are presented of tests with these modules. Gemme, C Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(02)02015-6 87-92 501 2003 2003 The ATLAS experiment will use a pixel detector as the innermost part of its semiconductor tracker. The pixel detector consists of three cylindrical layers in the barrel part and three disks in the forward and backward parts. The detector is designed to operate with a 40 MHz bunch crossing frequency, a high particle flux density and an extreme radiation environment at LHC. The main characteristics of the project are illustrated together with recent experimental results. Keil, Markus Adam, W Berdermann, E Bergonzo, P de Boer, Wim Bogani, F Borchi, E Brambilla, A Bruzzi, Mara Colledani, C Conway, J D'Angelo, P Dabrowski, W Delpierre, P A Dulinski, W Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(02)02025-9 153-159 501 2003 2003 Diamond is a promising sensor material for future collider experiments due to its radiation hardness. Diamond pixel sensors have been bump bonded to an ATLAS pixel readout chip using PbSn solder bumps. Single chip devices have been characterised by lab measurements and in a high-energy pion beam at CERN. Results on charge collection, spatial resolution, efficiency and the charge carrier lifetime are presented. Gan, K.K. Arms, Kregg E. Johnson, M. Kagan, H. Kass, R. Rush, C. Smith, S. Ter-Antonian, R. Zoeller, M.M. Ciliox, A. Holder, M. Ziolkowski, M. Nucl. Phys. B, Proc. Suppl. 10.5170/CERN-2003-006.102 282-287 125 2003 2003 We have developed two radiation-hard ASICs for optical data transmission in the ATLAS pixel detector at the LHC at CERN: a driver chip for a Vertical Cavity Surface Emitting Laser (VCSEL) diode for 80 Mbit/s data transmission from the detector, and a Bi-Phase Mark decoder chip to recover the control data and 40 MHz clock received optically by a PIN diode. We have successfully implemented both ASICs in 0.25 um CMOS technology using enclosed layout transistors and guard rings for increased radiation hardness. We present results from prototype circuits and from irradiation studies with 24 GeV protons up to 57 Mrad (1.9 x 10e15 p/cm2). Gorelov, I Gorfine, G W Hoeferkamp, M Mata-Bruni, V Santistevan, G Seidel, S C Ciocio, A Einsweiler, Kevin F Emes, J Gilchriese, M G D Joshi, A Kleinfelder, S A Marchesini, R McCormack, F Milgrome, O Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(02)00557-0 202-217 489 1-2 2002 2002 Prototype sensors for the ATLAS silicon pixel detector have been electrically characterized. The current and voltage characteristics, charge-collection efficiencies, and resolutions have been examined. Devices were fabricated on oxygenated and standard detector-grade silicon wafers. Results from prototypes which examine p-stop and standard and moderated p-spray isolation are presented for a variety of geometrical options. Some of the comparisons relate unirradiated sensors with those that have received fluences relevant to LHC operation. Fischer, P 10.5170/CERN-2002-003.91 2002 2002 Lari, Tommaso 2002 2002 Silicon pixel detectors produced according to the ATLAS Pixel Detector design were tested in a beam at CERN in the framework of the ATLAS collaboration. The detectors used n+/n sensors with oxygenated silicon substrates. The experimental behaviour of the detectors after irradiation to 1.1 10**15 n_eq/cm**2 and 600 kGy is discussed. At the sensor bias voltage of 600 V the depleted depth is measured to be 229 um, the mean collected charge is 20000 electrons, the detection efficiency is 98.2% and the spatial resolution is 9.6 um Treis, J. Fischer, P. Kruger, H. Klingbeil, L. Lari, T. Wermes, N. Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(02)00913-0 116-127 490 2002 2002 A PC based high speed silicon microstrip beam telescope consisting of several independent modules is presented. Every module contains an AC-coupled double sided silicon microstrip sensor and a complete set of analog and digital signal processing electronics. A digital bus connects the modules with the DAQ PC. A trigger logic unit coordinates the operation of all modules of the telescope. The system architecture allows easy integration of any kind of device under test into the data acquisition chain. Signal digitization, pedestal correction, hit detection and zero suppression are done by hardware inside the modules, so that the amount of data per event is reduced by a factor of 80 compared to conventional readout systems. In combination with a two level data acquisition scheme, this allows event rates up to 7.6 kHz. This is a factor of 40 faster than conventional VME based beam telescopes while comparable analog performance is maintained achieving signal to noise ratios of up to 70:1. The telescope has been tested in the SPS testbeam at CERN. It has been adopted as the reference instrument for testbeam studies for the ATLAS pixel detector development. Gorelov, I Int. J. Mod. Phys. A 1100-1102 16 1 2001 2001 The ATLAS experiment is now in the process of finalizing the development of the design of silicon pixel sensors for use in the pixel detector. The sensors will be operated in a severe LHC radiation environment with bias voltages at the end of lifetime up to 600 V while maintaining a good signal-to-noise ratio and charge collection efficiency, small cell size and minimal multiple scattering. The radiation hardness issues and quality assurance procedures are discussed. (4 refs). Hügging, F G Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)01882-4 143-9 477 1-3 2002 2002 For the ATLAS Pixel Detector, prototype sensors have been successfully developed. For the sensors design, attention was given to survivability of the harsh LHC radiation environment leading to the need to operate them at several hundreds of volts, while maintaining a good charge collection efficiency, small cell size and minimal multiple scattering. For a cost effective mass production, a bias grid is implemented to test the sensors before assembly under full bias. (6 refs). Wüstenfeld, J 1998 1998 Gan, K.K. PoS 10.22323/1.007.0266 266 hep2001 2001 2001 We present new results on the optical link for the pixel detector of the ATLAS experiment. An optical package of novel design has been developed for the opto-link. The design is based on a simple connector-type concept and is made of radiation-hard material. The receiver (DORIC) and transmitter (VDC) chips have been designed. The prototype results using the 0.8 and 0.25 um technologies are presented. Tappers, G Froidevaux, Daniel Hallewell, G D Rossi, L Tyndel, M 1999 1999 Parker, A Ragusa, F Tyndel, M 1998 1998 Jenni, Peter Ellis, Nick Williams, H 1998 1998 Kersten, S Bayer, C Berry, S Bonneau, P Bosteels, Michel Hallewell, G D Imhäuser, M Kind, P Pimenta dos Santos, M A Vacek, V Sasaki, O 10.5170/CERN-2001-005.396 2001 2001 Lari, T 2001 2001 Test beam characterization of prototypes of ATLAS silicon pixel sensors is discussed. Some of the sensors were irradiated to fluences up to 10**15 n_eq/cm**2. Measurements of charge collection efficiency, particle detection efficiency, depletion depth, Lorentz angle and spatial resolution have been performed. A model to compute the value of Lorentz angle from the charge drift properties in silicon is presented and found to be in agreement with test beam data. The Lorentz angle is found to be dependent on the mean electric field in the sensor, hence it changes varying the applied bias voltage. In the last chapter a study of ATLAS tracking and b-tagging performances is made using the GEANT simulation of the detector. The study is performed for two different algorithms to reconstruct the pixel cluster position and for the different values of the pixel bias voltage. Hügging, F G 2001 2001 The innermost subdetector of the ATLAS Experiment is a hybrid pixel detector which consists of about 150 million pixel on roughly 2000 modules for a high resolution tracking and b-tagging in the LHC enviroment. The scope of this theses is the successful development of silicon pixel sensors for the ATLAS Pixel Detector. The main attention for the design was given to survivability in the harsh radiation enviroment of LHC up to a fluence 10^{15} n_{eq}/cm^2during 10 years of operation. This leads to the need of long term operation at several hundreds of volts, partially depleted while maintaining good charge collection, small cell size and thin sensors reducing multiple scattering. Additionally, a punch through bias grid for testing the sensors before assembly under realistic bias conditions is implemented to allow a quality assurance. The design of the ATLAS pixel sensor is explained in detail and the results of the prototype sensors showing the capability of the chosen sensor design to cope with the challenging requirements of an operation in the LHC enviroment are presented. Furthermore the possibility of transfering this silicon sensor design approach to biomedical or other applications is discussed. Postranecky, M Butterworth, J Hayes, D Lane, J Warren, M 10.5170/CERN-2001-005.222 2001 2001 Beccherle, R 10.5170/CERN-2001-005.109 2001 2001 Kersten, S. Imhauser, M. Imhaeuser, M. Kind, P. Burckhart, H. Hallgren, B. Hallewell, G. Vacek, V. eConf THBT002 C011127 2001 2001 The innermost part of the ATLAS experiment will be a pixel detector containing around 1750 individual detector modules. A detector control system (DCS) is required to handle thousands of I/O channels with varying characteristics. The main building blocks of the pixel DCS are the cooling system, the power supplies and the thermal interlock system, responsible for the ultimate safety of the pixel sensors. The ATLAS Embedded Local Monitor Board (ELMB), a multi purpose front end I/O system with a CAN interface, is foreseen for several monitoring and control tasks. The Supervisory, Control And Data Acquisition (SCADA) system will use PVSS, a commercial software product chosen for the CERN LHC experiments. We report on the status of the different building blocks of the ATLAS pixel DCS. Vrba, V Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00342-4 27-33 465 1 2001 2001 The Pixel Detector of the ATLAS experiment at LHC is described with emphasis on recent developments. The ATLAS Pixel Detector consists of three cylindrical layers in the barrel part and of two times five disk layers in the forward and backward parts. The system is designed to operate with 40 MHz bunch crossing frequency, high particle flux densities and the extreme radiation environment at LHC. The project is presently entering the pre-production and production phase for a number of items. Design features of the detector and prototype results are presented. (9 refs). Olcese, M Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00346-1 51-9 465 1 2001 2001 A review of the design choices for the mechanical support of the new generation pixel detectors (ALICE, ATLAS, CMS, BTeV) is presented. Material selection and specific cooling solutions versus requirements are discussed. (5 refs). Hügging, F G Gössling, C Klaiber Lodewigs, Jonas M Wüstenfeld, J Wunstorf, R Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00350-3 77-82 465 1 2001 2001 Silicon pixel sensors for the ATLAS pixel detector have been successfully developed. The main attention for the design was given to survivability in the harsh radiation environment of LHC up to a fluence of 10/sup 15/n/sub eq//cm/sup 2/ during 10 years of operation. This leads to the need of long term operation at several hundreds of volts, partially depleted while maintaining good charge collection, small cell size and thin sensors reducing the multiple scattering. Additionally, a bias grid for testing the sensors before assembly under realistic bias conditions is implemented to allow a quality assurance. (14 refs). Boscardin, M Betta, G F D Gregori, P Zen, M Zori, N Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00353-9 83-7 465 1 2001 2001 We report on the development of a fabrication technology for n-on-n silicon pixel detectors oriented to the ATLAS experiment at LHC. The main processing issues and some selected results from the electrical characterization of detector prototypes and related test structures are presented and discussed. (5 refs). Gregor, I M Weidberg, A R Lee, S C Chu, M L Teng, P K Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00370-9 131-4 465 1 2001 2001 ATLAS (The ATLAS Technical Proposal, CERN/LHCC 94-33) is one of the large electronic particle detectors at LHC (The LHC Conceptual Design, Report-The Yellow Book, CERN/AC/95-05(LHC)) which will become operational in 2005, it is planned to use radiation tolerant optical links for the data transfer from the semiconductor tracker (SCT) (ATLAS Inner Detector Technical Proposal, CERN/LHCC 97-16 and CERN /LHCC 91-17) and pixel detector (ATLAS Pixel Detector Technical Proposal, CERN/LHCC 98-13) systems to the acquisition electronics over a distance up to 140 m. The overall architecture and the performance of these optical data links are described. One of the three candidate designs for an on-detector Opto-Package is presented. (10 refs). Fischer, P Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00380-1 153-8 465 1 2001 2001 The ATLAS experiment at LHC will use 3 barrel layers and 2*5 disks of silicon pixel detectors as the innermost elements of the semiconductor tracker. The basic building blocks are pixel modules with an active area of 16.4 mm*60.8 mm which include an n/sup +/ on n-type silicon sensor and 16 VLSI front-end (FE) chips. Every FE chip contains a low power, high speed charge sensitive preamplifier, a fast discriminator, and a readout system which operates at the 40 MHz rate of LHC. The addresses of hit pixels (as well as a low resolution pulse height information) are stored on the FE chips until arrival of a level 1 trigger signal. Hits are then transferred to a module controller chip (MCC) which collects the data of all 16 FE chips, builds complete events and sends the data through two optical links to the data acquisition system. The MCC receives clock and data through an additional optical link and provides timing and configuration information for the FE chips. Two additional chips are used to amplify and decode the pin diode signal and to drive the VCSEL laser diodes of the optical links. (5 refs). Baratella, A Dameri, M Morettini, P Parodi, F Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00481-8 190-4 465 1 2001 2001 A fast track reconstruction algorithm for the ATLAS second level trigger is presented. The timing performance (3.5 ms for a jet reconstruction at low luminosity) is satisfactory; the transverse impact parameter resolution (75 mu m) is sufficient to perform an on- line b-tagging, and the full three-dimensional reconstruction produces good seeds for more sophisticated track searches. (4 refs). Gemme, C Fiorello, A M Gagliardi, G Gilchriese, M G D Netchaeva, P Rossi, L Ruscino, E Vernocchi, F Varasi, M Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00390-4 200-3 465 1 2001 2001 The bump-bonding technology is used to join the front-end read-out chips to the silicon substrate of the ATLAS pixel detector. We review the current status of the technology used by Alenia Marconi Systems and we report on the electrical and mechanical properties and the defect rate of the indium bumps. (1 refs). Netchaeva, P Beccherle, R Darbo, G Einsweiler, Kevin F Gagliardi, G Gemme, C Gilchriese, M G D Oppizzi, P Richardson, J Rossi, L Ruscino, E Vernocchi, F Znizka, G Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00391-6 204-10 465 1 2001 2001 Modules are the basic building blocks of the ATLAS pixel detector system, they are made of a silicon sensor tile containing ~46000 pixel cells of 50 mu m*400 mu m, 16 front-end chips connected to the sensor through bump bonding, a kapton flex circuit and the module controller chip. The pixel detector is the first to encounter particles emerging from LHC interactions, minimization of radiation length of pixel modules is therefore very important. We report here on the construction techniques and on the operation of the first ATLAS pixel modules of 0.7% radiation length thickness. We have operated these modules with threshold of 3700*10+or-300*10, mean noise value of 225*10 and 0.3% dead channels. (3 refs). Grah, C Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00392-8 211-18 465 1 2001 2001 For the upcoming ATLAS-experiment at CERN it is planned to build a large area pixel detector, providing more than 100*10/sup 6/ sensor cells. For the innermost layer, the B-physics layer, it is planned to use MCM-D technology to perform the signal interconnections and power distribution on the modules. Focus of this paper is to give an introduction to this technology and present measurements on single chip MCM-D assemblies and a full scale MCM-D module prototype. (10 refs). Gagliardi, G Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)01245-1 275-81 466 2 2001 2001 The ATLAS pixel detector readout electronics has been designed to extract the signal of the passage of ionizing particle from over 45000 diodes that form the ATLAS pixel detector module and to cope with both the very high data rate expected in the LHC environment and the trigger requirements in the ATLAS detector. The on-detector electronics must supply early data sparsification and reduction as well as local memory and derandomizing buffers. The readout functionality has been distributed over a two-level readout architecture. A description of the module readout architecture and an overview of the prototype results are reported. (5 refs). Wunstorf, R Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00568-X 327-34 466 2 2001 2001 The pixel detector in the ATLAS experiment at the LHC, Geneva, is an important detector component for high resolution tracking and vertex identification. For this demanding task the hybrid pixel detector with silicon sensors has to work in a very harsh radiation environment with up to 3.5*10/sup 14/ n/sub eq//cm/sup 2/ per year. On the basis of the known radiation effects a dual-track strategy was followed for the development of radiation tolerant silicon pixel sensors. The ATLAS pixel collaboration successfully developed the radiation hard sensor design which meets the challenging requirements for the ATLAS pixel detector. In parallel, the hardening of the silicon itself was followed within the ROSE collaboration, which developed the radiation tolerant DOFZ-silicon with oxygen enrichment by diffusion. Taking all the results together the radiation tolerant silicon sensors have been designed, produced and showed excellent performance before and after irradiation. (21 refs). Andreazza, A Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(00)01197-9 168-71 461 1-3 2001 2001 The pixel detector of the ATLAS experiment at the LHC is a silicon vertex tracker consisting of 100 million 50*400 mu m/sup 2/ pixels. Sensors have been produced, able to withstand a radiation damage equivalent to the one induced by a fluence of 10/sup 15/ 1 MeV n/cm /sup 2/, as expected after 10 years at the LHC. Prototypes of modules have shown both noise and threshold uniformity better than 200 e. Radiation hard versions of the readout electronics are currently being tested. (8 refs). Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(00)00682-3 461-7 453 1-2 2000 2000 The radiation environment in the inner detector has been simulated using the particle transport program FLUKA with a recent description of the ATLAS experiment. Given in this paper are particle fluences and doses at positions relevant to the three inner detector subsystems; the Pixel, SCT and TRT detectors. In addition, studies are reported on in which (1) information concerning the optimization of the inner detector neutron-moderators is obtained and (2) the impact of including additional vacuum-equipment material is assessed. (19 refs). Gan, K K Int. J. Mod. Phys. 10.1142/S0217751X01009028 1103-1105 161 2001 2001 An optical package of novel design has been developed for the ATLAS pixel detector. The package contains two VCSELs and one PIN diode to transmit and receive optical signals. The design is based on a simple connector-type concept and is made of radiation-hard material. Several packages have been fabricated and show promising results. Aleppo, Mario Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00364-3 108-111 465 2000 2001 Silicon pixel detectors developed to meet LHC requirements were tested in a beam at CERN in the framework of the ATLAS collaboration. The experimental behaviour of irradiated and not-irradiated sensors in a magnetic field is discussed. The measurement of the Lorentz angle for these sensors at different operating conditions is presented. A simple model of the charge drift in silicon before and after irradiation is presented. The good agreement between the model predictions and the experimental results is shown. Lari, Tommaso Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)00365-5 112-14 465 1 2001 2001 Standard as well as irradiated silicon pixel detectors developed for the ATLAS experiment were tested in a beam. Digital and analog resolutions were determined comparing the positions measured by a microstrip telescope and by the pixel detector. Digital resolutions of 10 um and analog resolutions of 6 um (before irradiation) and 10 um (after irradiation) are obtained without subtracting the error on the position determined by the telescope. Andreazza, A 2000 2000 The pixel detector of the ATLAS experiment at the LHC is a silicon vertex tracker consisting of 100 million 50x400 um^2 pixels. Sensors have been produced, able to withstand a radiation damage equivalent to the one induced by a fluence of 10^15 1 MeV n/cm^2, as expected after 10 years at the LHC. Prototypes of modules have shown both noise and threshold uniformity better that 200 e. Radiation hard version of the readout electronics is currently being tested Bayer, C Berry, S Bonneau, P Bosteels, Michel Burckhart, H J Cragg, D English, R Hallewell, G D Hallgren, Björn I Kersten, S Kind, P Langedrag, K Lindsay, S Merkel, M Stapnes, Steinar Thadome, J Vacek, V 10.5170/CERN-2000-010.398 2000 2000 Blanquart, L 10.5170/CERN-2000-010.100 2000 2000 Wüstenfeld, J 2000 2000 Basken, O Becks, K H Ehrmann, O Gerlach, P Grah, C Gregor, I M Linder, C Meuser, S Richardson, J Topper, M Wolf, J IEEE Trans. Nucl. Sci. 10.1109/23.856508 745-9 47 3, pt.2 2000 2000 The innermost layer (b-physics layer) of the ATLAS Pixel Detector will consist of modules based on MCM-D technology. Such a module consists of a sensor tile with an active area of 16.4 mm*60.4 mm, 16 read out ICs, each serving 24* 160 pixel unit cells, a module controller chip (MCC), an optical transceiver and the local signal interconnection and power distribution busses. We show a prototype of such a module with additional test pads on both sides. The outer dimensions of the final module will be 21.4 mm*67.8 mm. The extremely high wiring density, which is necessary to interconnect the read-out chips, was achieved using a thin film copper/photo-BCB process on the pixel array. The bumping of the read out chips was done using electroplating PbSn. All dice are then attached by flip-chip assembly to the sensor diodes and the local busses. The focus of this paper is the description of the first results of such MCM-D-type modules. (11 refs). Barberis, D Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(00)00041-3 331-7 446 1-2 2000 2000 The ATLAS Inner Detector consists of three layers of silicon pixels, four double layers of silicon microstrips and a Transition Radiation Tracker (straw tubes). The good performance of the track and vertex reconstruction algorithms is a direct consequence of the small radius (4.3, 10.1 and 13.2 cm), fine pitch ($50 \times 300~\mu$m) and low occupancy ($<3 \times 10^{-4}$ at design luminosity) of the pixel detectors, and of the good tracking capabilities of the SCT and the TRT. The full detector simulation is used to evaluate the performance of the detector and of the reconstruction algorithms. Results are presented on track and vertex reconstruction efficiencies and resolutions, and on the separation between $b$-jets and jets produced by light quarks. Rossi, Leonardo Proc. SPIE 295-300 3830 1999 1999 The MCM-D which is described here is a prototype for a pixel detector system for the planned Large Hadron Collider (LHC) at CERN, Geneva. The project is within the ATLAS experiment. The module consists of a sensor tile with an active area of 16.4 mm*60.4 mm, 16 readout chips, each serving 24*160 pixel unit cells, a module controller chip, an optical transceiver and the local signal interconnection and power distribution buses. The extremely high wiring density which is necessary to interconnect the readout chips was achieved using a thin film copper/photo-BCB process above the pixel array. The bumping of the readout chips was done by PbSn electroplating. All dice are then attached by flip-chip assembly to the sensor diodes and the local buses. The focus of this paper is a detailed description of the technologies for the fabrication of this advanced MCM-D. (10 refs). Anderssen, E Bintinger, D L Berry, S Bonneau, P Bosteels, Michel Bouvier, P Cragg, D English, R Godlewski, J Górski, B Grohmann, S Hallewell, G D Hayler, T Ilie, S Jones, T Kadlec, J Lindsay, S Miller, W Niinikoski, T O Olcese, M Olszowska, J Payne, B Pilling, A Perrin, E Sandaker, H Seytre, J F Thadome, J Vacek, V 10.5170/CERN-1999-009.421 Cooling Evaporative Fluorocarbon Irradiations Low-Mass Pixel SCT Silicon 1999 1999 Heat transfer coefficients 2-5.103 Wm-2K-1 have been measured in a 3.6 mm I.D. heated tube dissipating 100 Watts - close to the full equivalent power (~110 W) of a barrel SCT detector "stave" - over a range of power dissipations and mass flows in the above fluids. Aspects of full-scale evaporative cooling circulator design for the ATLAS experiment are discussed, together with plans for future development. Charlton, D G Dowell, John D Homer, R James Jovanovic, P Kenyon, Ian Richard Mahout, G Shaylor, H R Wilson, J A Gregor, I M Nickerson, R B Mandic, I Wastie, R L Weidberg, A R Galagedera, S B Morrissey, M Troska, Jan K White, D J Rudge, A 10.5170/CERN-1999-009.185 2000 2000 Richardson, J 10.5170/CERN-1999-009.83 1999 1999 D'Auria, S D Nucl. Phys. B, Proc. Suppl. 10.1016/S0920-5632(99)00617-9 639-44 78 1999 1999 This work describes the R and D work on radiation resistant silicon sensors for the ATLAS pixel detector: the technological choices and the design will be illustrated. Some sensor prototypes have been characterised and tested with unirradiated front-end electronics before and after high energy proton irradiation, showing that we can achieve the required radiation resistance to fluences of 1*10/sup 15/ cm/sup -2/ using n/sup +/ on n sensors with the p-spray isolation technology. (16 refs). Ackers, M André, F Blanquart, L Bonzom, V Comes, G Fischer, P Keil, M Kühl, T Meuser, S Delpierre, P A Treis, J Raith, B A Wermes, N IEEE Trans. Nucl. Sci. 10.1109/23.819277 2033-2038 46 1999 1999 Pixel detectors with a high granularity and a very large number of sensitive elements (cells) are a very recent development used for high precision particle detection. At the Large Hadron Collider LHC at CERN (Geneva) a pixel detector with 1.4*10/sup 8/ individual pixel cells is developed for the ATLAS detector. The concept is a hybrid detector. Consisting of a pixel sensor connected to a pixel electronics chip by bump and flip chip technology in one-to-one cell correspondence. The development and prototype results of the pixel front end chip are presented together with the physical and technical requirements to be met at LHC. Lab measurements are reported. (6 refs). Blanquart, L Bonzom, V Comes, G Delpierre, P A Fischer, P Hausmann, J C Keil, M Lindner, Manfred Meuser, S Wermes, N Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(99)00906-7 403-12 439 2-3 2000 2000 The demanding requirements for pixel readout electronics for high- energy physics experiments and biomedical applications are reviewed. Some examples of the measured analog performance of prototype chips are given. The readout architectures of the PIxel readout for the ATlas experiment (PIRATE) chip suited for LHC experiments and of the multi-picture element counter (MPEC) counting chip targeted for biomedical applications are presented. First results with complete chip-sensor assemblies are also shown. (12 refs). Hügging, F G Lutz, Gerhard Richter, R H Rohe, T Wunstorf, R Wüstenfeld, J Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(99)00913-4 529-35 439 2-3 2000 2000 The inner detectors of LHC experiments will contain pixel detectors covering an area of several square meters. In addition they are facing the harsh radiation environment of the LHC. A first prototype sensor has been designed according to the requirements of the ATLAS experiment, produced and successfully tested with static measurements. Irradiation tests have also been performed with excellent results. The sensor is an n/sup +/n-device in order to allow partial depleted operation after bulk inversion and a guard ring scheme keeping the entire detector surface close to the electronic chip on ground potential. Further, a bias structure is introduced providing testability of the sensors prior to bump bonding and flip chipping. (13 refs). Troncon, C IEEE Trans. Nucl. Sci. 10.1109/23.856507 737-44 47 3, pt.2 2000 2000 Results are reported from beam tests of prototype silicon pixel sensors and front-end electronics with analog readout developed for use in the ATLAS experiment at the Large Hadron Collider (LHC).Both irradiated and unirradiated assemblies were tested for chargecollection, efficiency and position resolution measurements. These indicate that n+ in n silicon pixel detectors with p-spray isolationcan operate after irradiation to fluences of up to 10**15 neq/cm2without significant degradation in performance. The depletion depthof irradiated sensors was measured and their behaviour in a magnetic field was studied. The Lorentz angle was found to decrease significatively after irradiation. Comparison between performance on spatial resolutionwith digital or analogical readout is also presented. Ragusa, F Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(00)00187-X 184-93 447 1-2 2000 2000 Silicon pixel detectors, developed to meet LHC requirementswere tested in 1998 and 1999 within the Atlas collaboration in the H8 beam test at CERN. Different sensor designs have been developed and studied using an analog front end electronics chip. In this work a detailed experimental study of the overall performanceof both irradiated and not irradiated detectors for the different designs is presented, with special emphasis to efficiency, charge collection and resolution measurements.Behaviour of detectors in a magnetic field is also discussed. Parker, A Ragusa, F Tyndel, M 1998 1998 -Overview of the inner detector -Pixel test beam results -SCT status report Darbo, G Nucl. Phys. B, Proc. Suppl. 10.1016/S0920-5632(99)00555-1 263-8 78 1999 1999 This article describes the ATLAS pixel detector. Layout and parameters are determined by performance requirements, while the intense radiation environment near the LHC collision point impose severe constraints on the design. A demonstrator program is under way to develop a prototype which is close enough to ATLAS requirements and to give us the confidence that we can build the detector we propose. Results from this demonstrator program are reported. (7 refs). Wermes, N Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(01)01890-3 121-128 477 1-3 2002 2002 The ATLAS experiment at the LHC will have three barrel and two times five disk layers of silicon pixel detectors as the innermost elements of the Inner Tracking Detector. the detctor is built adopting the hybrid pixel technology in which 16 highly permormant FE chips are connected to a silicon sensor by means of the bump and flip-chip technique. Owing to the high bunch crossing rate of 40 MHz at the LHC and the high particle fluences a sophisticated design concept is employed. The projet is presently entering the pre-production phase. The various aspects of the detector, the expected performance and the so far obtained prototype results are presented. Rossi, L Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(99)00417-9 80-90 435 1-2 1999 1999 I will describe the layout and parameters of the pixel detector system designed for ATLAS. The performance requirements, and the desired lifetime of the system in the intense radiation environment near the LHC collision point impose severe constraints on the design. Some of the key issues of the ATLAS pixel design will be illustrated together with recent experimental results. (6 refs). Barberis, D Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(99)00418-0 91-101 435 1-2 1999 1999 The ATLAS inner detector consists of three layers of silicon pixels, four double layers of silicon microstrips and a transition radiation tracker (straw tubes). The good performance of the track and vertex reconstruction algorithms is a direct consequence of the small radius (4.3, 10.1 and 13.2 cm), fine pitch (50*300 mu m) and low occupancy (<3*10/sup -4/ at design luminosity) of the pixel detectors. The full (GEANT3) detector simulation is used to evaluate the performance of the detector and of the reconstruction algorithms. Results are presented on track and vertex reconstruction efficiencies and resolutions, and on the separation between b-jets and jets produced by light quarks. (8 refs). Einsweiler, Kevin F Joshi, A Marchesini, R Pengg, F X Zizka, G 1999 1999 The analog frontend of pixel readout electronics with dual threshold discriminator scheme has been measured extensively to determine the conditions for optimum performance as well as the circuits performance limitations. The $9 preamplifier shows a peaking time of 20 ns without capacitive load, which degrades to only 30 ns with a load of 350 fE The LEVEL-discriminator has an adjustable threshold in the range of 2000 to 6000 e/sup -/ with a variable $9 separation to the TIME-discriminator threshold of 800 to 1600e/sup -/. The circuit allows the full suppression of out-of-time signals under the conditions of 350 fF capacitive load and a total power consumption of 40 mu W per cell. $9 The untuned threshold dispersion is measured to be 320 e/sup -/ r.m.s., which reduces to 70 e/sup -/ r.m.s, after threshold adjust. The overall noise of the circuit reaches a value of about 200 e/sup -/ r.m.s. With 350 fF capacitive $9 load and 20 nA of parallel current at the preamplifier input. Further measurements characterize the time-over-threshold (TOT) behaviour and the double- pulse resolution of the circuit. (4 refs). Einsweiler, Kevin F Joshi, A Kleinfelder, S A Luo, L Marchesini, R Milgrome, O Pengg, F X IEEE Trans. Nucl. Sci. 10.1109/23.775508 166-170 46 1999 1999 A low power sparse scan readout architecture has been developed for the ATLAS pixel front-end IC. The architecture supports a dual discriminator and extracts the time over threshold (TOT) information along with a 2-D spatial address $9 of the hits associating them with a unique 7-bit beam crossing number. The IC implements level-1 trigger filtering along with event building (grouping together all hits in a beam crossing) in the end of column (EOC) buffer. The $9 events are transmitted over a 40 MHz serial data link with the protocol supporting buffer overflow handling by appending error flags to events. This mixed-mode full custom IC is implemented in 0.8 mu HP process to meet the $9 requirements for the pixel readout in the ATLAS inner detector. The circuits have been tested and the IC provides dead-time-less ambiguity free readout at 40 MHz data rate. Becks, K H Beyne, E Ehrmann, O Gerlach, P Gregor, I M Pieters, P Topper, M Truzzi, C Wolf, J IEEE Trans. Nucl. Sci. 10.1109/23.819241 1861-1864 46 1999 1999 For the ATLAS experiment at the planned Large Hadron Collider LHC at CERN hybrid pixel detectors are being built as innermost layers of the inner tracking detector system. Modules are the basic building blocks of the ATLAS pixel $9 detector. A module consists of a sensor tile with an active area of 16.4 mm*60.4 mm, 16 read out IC's, each serving 24*160 pixel unit cells, a module controller chip, an optical transceiver and the local signal interconnection and $9 power distribution busses. The dies are attached by flip-chip assembly to the sensor diodes and the local busses. In the following a module based on MCM-D technology will be discussed and prototype results will be presented. Beccherle, R 1998 1998 The ATLAS pixel detector is organized in 3 barrels and 5 forward and backward disks. The basic building block for each of those detector components is the detector module. There are a total of 2,228 of them, each one having 16 $9 analog front-end (FE) chips, bump-bonded to individual diodes of a silicon detector, and a module controller chip (MCC). There are 61,440 channels in a module for an active area 16*64 mm/sup 2/ which are controlled and read out by a $9 MCC. Therefore in total there are 1.4*10/sup 8/ channels to be read out the whole detector. Main LHC constraints are 40 MHz bunch crossing, 75 kHz Level 1 trigger rate, 2.5 mu s Level 1 trigger latency and a dose of 300 kGy (1*10/sup $9 15/ cm/sup -2/ 1 MeV neutron equivalent fluence), for the innermost barrel. The MCC described in this paper is a non rad-hard version which is used for the ATLAS pixel demonstrator program. (3 refs). 1998 1998 Daccà, A Gemme, G Parodi, R 1998 1998 Skubic, P L Boyd, R Krishnama, S Neriyanuri, K Severini, H Hennessy, W Nucl. Instrum. Methods Phys. Res., A 219-23 465 1 2001 2001 Anderssen, E Bintinger, D L Emes, J Gilchriese, M G D McCormack, F Miller, W O 1998 1998 Budinsky, R Hallenell, G Lenzen, Georg Thadome, J Vacek, V 1998 1998 Kühl, T 1998 1998 Richardson, John 12.02 1999 1999 The ATLAS experiment, at the Large Hadron Collider, will incorporate discrete, high-resolution tracking sub-systems in the form of segmented silicon detectors with 40MHz radiation-hard readout electronics. In the region closest to the pp interaction point, the thin silicon tiles will be segmented into a pixel geometry providing two-dimensional space-point information. The current status of the ATLAS pixel project will be presented with an emphasis on the performance of the front-end electronics and prototype sensors. Wermes, Norbert Hallewel, G 1998 1998 1998 1998 1998 1998 1998 1998 Mekkaoui, A Christian, D Kwan, S Srage, J Yarema, R J 1998 1998 Skubic, P L Boyd, R Hennessy, W Krishnama, S Neriyanuri, K Severini, H 1998 1998 Seidel, S 1998 1998 Darbo, G 1998 1998 Gagliardi, G 1998 1998 Rohe, T Hügging, F G Lutz, Gerhard Richter, R H Wunstorf, R Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(97)01266-7 224-228 409 1-3 1998 1998 Fasching, D 1998 1998 Wüstenfeld, J 1998 1998 Morettini, P Dameri, M Rossi, L 1997 1997 Darbo, G 1997 1997 Mouthuy, T 1995 1995 Fischer, P Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(98)00083-7 152-156 409 1-3 1998 1998 Vacavant, L 1997 1997 The capability of the \atlas~detector to tag $b$-jets is studied, usin g the impact parameter of charged tracks. High $b$-tagging performance is needed at \lhc, especially during the first years of running, in order to see evidence of the Higgs boson if its mass lies between 80 and 120 GeV$/c^{2}$. A pattern-recognition algorithm has been developed for this purpose, using a detailed simulation of the \atlas~inner detector. Track-findin g starts from the pixel detector layers. A "hyper-plane" concept allows the use of a simple tracking algorithm though the complex geome try. High track-finding efficiency and reconstruction quality ensure the discrimination of $b$-jets from other kinds of jets. After full simulation and reconstruction of $H \rightarrow b\bar{b}$, $H \rightarrow gg$, $H\rightarrow u\bar{u}$, $H \rightarrow s\bar{s}$ and $H\rightarrow c\bar{c}$ events ($m_{H}=100$ GeV$/c^{2}$), the mean rejections achieved against non-$b$-jets for a 50\% $b$-jet tagging efficiency are as follows: \vspace{-5mm} \begin{Tabhere}\centering \begin{tabular}{cccc} \hspace{3cm} & \hspace{3cm} & \hspace{3cm} & \hspace{3cm} \\ $R_{g}=39 \pm 5$ & $R_{u}=60 \pm 9$ & $R_{s}=38 \pm 5$ & $R_{c}=9 \pm 1$ \\ \end{tabular} \end{Tabhere} The analysis of data from the first radiation-hard pixel detector prototypes justifies the potential of these detectors for track-finding and high-precision impact parameter measurement at~\lhc. Delpierre, P A Arrighi, C Blanquart, L Bonvicini, V Boutonnet, C Clemens, J C Cohen-Solal, M Fallou, A Habrard, M C Hallewell, G D Heuser, J M Izani, P Jaeger, J J Kersten, S Mekkaoui, A Middelkamp, P Mouthuy, T Perego, R Pindo, M Potheau, R Redaelli, N G Sauvage, D Waisbard, J 1993 1993 Rossi, L ATLAS eNews 1 200207 Wermes, Norbert Inner Detector Technology Detectors ATLAS Detector Testing pixel 2002 2002 ATLAS Pixel Module on Support Test Card Inner Detector Technology Detectors pixel ATLAS Detector Testing 2001 2001 Photos 1,2,3,4,5,6,7 - Photos taken before irradiation of Pixel Test Analog Chip and Pmbars (April 2000) Photos 8,9,10,11 - Irradiation of VDC chips (May 2000) Photos 12, 13 - Irradiation of Passive Components (June 2000) Photos 14,15, 16 - Irradiation of Marebo Chip (November 1999) Barberis, D Baines, J T M Gavrilenko, I Gianotti, F Haywood, S Luehring, F C Pater, J R Pickford, A Poggioli, Luc Poppleton, A Ros, E Rozanov, A Stavropoulos, G D Simion, S 1997 1997 2000 2000 A review of the latest results from the WA97 experiment on the strange particle production in Pb-Pb and p-Pb collisions is presented. Transverse mass spectra and yields of K/sub S//sup 0/, Lambda , Xi , Omega and h/sup -/ (negatively charged particles) have been measured at central rapidity. Yields are studied as a function of the number of nucleons participating in the collision N/sub part/. From p-Pb to Pb-Pb collisions the particle yields per participant increase substantially. The enhancement is more pronounced for multistrange particles and exceeds an order of magnitude for Omega. (28 refs). Gilchriese, M G D 1998 1998 Wermes, N Nucl. Instrum. Methods Phys. Res., A 277-288 512 2003 2003 Semiconductor pixel detectors offer features for the detection of radiation which are interesting for particle physics detectors as well as for imaging e.g. in biomedical applications (radiography, autoradiography, protein crystallography) or in Xray astronomy. At the present time hybrid pixel detectors are technologically mastered to a large extent and large scale particle detectors are being built. Although the physical requirements are often quite different, imaging applications are emerging and interesting prototype results are available. Monolithic detectors, however, offer interesting features for both fields in future applications. The state of development of hybrid and monolithic pixel detectors, excluding CCDs, and their different suitability for particle detection and imaging, is reviewed. Wermes, N Nucl. Instrum. Methods Phys. Res., A 277-288 512 1-2 2003 2003 Semiconductor pixel detectors offer features for the detection of radiation which are interesting for particle physics detectors as well as for imaging e.g. in biomedical applications (radiography, autoradiography, protein crystallography) or in Xray astronomy. At the present time hybrid pixel detectors are technologically mastered to a large extent and large scale particle detectors are being built. Although the physical requirements are often quite different, imaging applications are emerging and interesting prototype results are available. Monolithic detectors, however, offer interesting features for both fields in future applications. The state of development of hybrid and monolithic pixel detectors, excluding CCDs, and their different suitability for particle detection and imaging, is reviewed. Berg, C Blanquart, L Bonzom, V Delpierre, P A Desch, Klaus Fischer, P Keil, M Meuser, S Raith, B A Wermes, N Nucl. Instrum. Methods Phys. Res., A 10.1016/S0168-9002(99)00760-3 80-90 439 1 2000 2000 The 12*63 pixel readout prototype chip Bieu&Pastis, designed to cope with the environment imposed on a pixel detector by high-energy proton-proton collisions as expected at the Large Hadron Collider (LHC), is described. The chip contains the full pixel cell functionality, but not yet the full peripheral architecture for data transfer and readout with LHC speed. Design considerations and lab tests to characterize the performance as well as some test beam results are described. (7 refs). Bonzom, V Blanquart, L Delpierre, P A Fischer, P Meuser, S Wermes, N 1997 1997