Showing papers by "Giovanni Darbo published in 2002"
University of New Mexico1, Lawrence Berkeley National Laboratory2, University of Bonn3, Technical University of Dortmund4, University of Genoa5, University of Wisconsin-Madison6, Centre national de la recherche scientifique7, University of Milan8, Max Planck Society9, University of Oklahoma10, Academy of Sciences of the Czech Republic11, Folkwang University of the Arts12, University of Udine13
01 Apr 2002-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the effect due to magnetic field variation was explained by the variation of the electric field inside the detectors arising from the different bias conditions, and the depletion depths of irradiated sensors at various bias voltages were also measured.
Abstract: Silicon pixel sensors developed by the ATLAS collaboration to meet LHC requirements and to withstand hadronic irradiation to fluences of up to $10^{15} n_eq/cm^{2}$ have been evaluated using a test beam facility at CERN providing a magnetic field. The Lorentz angle was measured and found to alter from 9.0 deg. before irradiation, when the detectors operated at 150 V bias at B=1.48 T, to 3.1 deg after irradiation and operating at 600 V bias at 1.01 T. In addition to the effect due to magnetic field variation, this change is explained by the variation of the electric field inside the detectors arising from the different bias conditions. The depletion depths of irradiated sensors at various bias voltages were also measured. At 600 V bias 280 micron thick sensors depleted to ~200 micron after irradiation at the design fluence of 1 10^{15} 1 MeV n_eq/cm2 and were almost fully depleted at a fluence of 0.5 * 10^{15} 1 MeV n_eq/cm2. The spatial resolution was measured for angles of incidence between 0 deg and 30 deg. The optimal value was found to be better than 5.3 micron before irradiation and 7.4 micron after irradiation.
53 citations
11 Oct 2002-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the authors describe the architecture of the Module Controller Chip for the ATLAS Pixel Detector and describe the hardware/software tools developed to test the MCC performance at the LHC event rate.
Abstract: 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.
44 citations
University of New Mexico1, Lawrence Berkeley National Laboratory2, University of Bonn3, Technical University of Dortmund4, University of Wisconsin-Madison5, University of Milan6, Max Planck Society7, University of Oklahoma8, Academy of Sciences of the Czech Republic9, Folkwang University of the Arts10, University of Wuppertal11
21 Aug 2002-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the current and voltage characteristics, charge collection efficiencies, and resolutions have been examined for the ATLAS pixel detector, which was fabricated on oxygenated and standard detector-grade silicon wafers.
Abstract: 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.
28 citations