S. Ceresa

The ALICE Silicon Pixel Detector control system and on-line calibration tools

The ALICE Silicon Pixel Detector (SPD) contains nearly 107 hybrid pixel cells. The operation of the SPD requires on-line control and monitoring of some 2000 parameters and ~ 50000 DACs. Information for each channel is stored in a configuration database. Timing and data management ( ~ 6 GB of raw data for each calibration) are critical issues. An overview of the SPD electronics read out chain and of the detector control system is given with a detailed description of the front-end controls and the calibration strategy. The status of commissioning and a preliminary evaluation of the detector performance are presented.

Performance of ALICE silicon pixel detector prototypes in high energy beams

The two innermost layers of the ALICE inner tracking system are instrumented with silicon pixel detectors. Single chip assembly prototypes of the ALICE pixels have been tested in high energy particle beams at the CERN SPS. Detection efficiency and spatial precision have been studied as a function of the threshold and the track incidence angle. The experimental method, data analysis and main results are presented.

The Assembly of the first Sector of the ALICE Silicon Pixel Detector

The Silicon Pixel Detector (SPD) is the innermost part of the Inner Tracking System (ITS) of the ALICE experiment at LHC. 240 detector ladders containing in total about 10 million pixel cells with dimension 50 × 425 µm2, have to be assembled on a carbon fibre support. The mounting procedure of the basic SPD modules (Half-Staves) and the assembly of the barrel sectors are presented. Results on the assembly of the first sector are reported.

The ALICE silicon pixel detector: electronics system integration

The ALICE silicon pixel detector (SPD) comprises the two innermost layers of the ALICE inner tracker system. The SPD includes 120 half staves each consisting of 10 ALICE pixel chips bump bonded to two silicon sensors and one multi-chip read-out module. Each pixel chip contains 8192 active cells, so that the total number of pixel cells in the SPD is ap107. The on-detector read-out is based on a multi-chip-module containing 4 ASICs and an optical transceiver module. The constraints on material budget detector module dimensions are very demanding

Beam Test Performance and Simulation of Prototypes for the ALICE Silicon Pixel Detector

The silicon pixel detector (SPD) of the ALICE experiment in preparation at the Large Hadron Collider (LHC) at CERN is designed to provide the precise vertex reconstruction needed for measuring heavy flavor production in heavy ion collisions at very high energies and high multiplicity. The SPD forms the innermost part of the Inner Tracking System (ITS) which also includes silicon drift and silicon strip detectors. Single assembly prototypes of the ALICE SPD have been tested at the CERN SPS using high energy proton/pion beams in 2002 and 2003. We report on the experimental determination of the spatial precision. We also report on the first combined beam test with prototypes of the other ITS silicon detector technologies at the CERN SPS in November 2004. The issue of SPD simulation is briefly discussed.

The Silicon Pixel Detector for ALICE Experiment

The Inner Tracking System (ITS) of the ALICE experiment is made of position sensitive detectors which have to operate in a region where the track density may be as high as 50 tracks/cm2. To handle such densities detectors with high precision and granularity are mandatory. The Silicon Pixel Detector (SPD), the innermost part of the ITS, has been designed to provide tracking information close to primary interaction point. The assembly of the entire SPD has been completed.