The Silicon Detectors
Silicon Detectors are very powerful devices in ultrarelativistic heavy ions experiments to reconstruct charged particles multiplicities in a wide angular region even in presence of very high track densities. Silicon Detectors own a high granularity and a excellent spacial precision required for tracks and vertices reconstruction.
The Inner Tracker System (ITS) of the ALICE experiment consists of six cylindrical layers of silicon detectors. The four innermost layers are truly two-dimensional devices, constituted by Silicon Pixel Detectors (SPD) and Silicon Drift Detectors (SDD). The outer two layers are constituted by double-sided Silicon microStrip Detectors (SSD).
The Rome group partecipates from the beginning of the ALICE experiment to the design and construction of the ITS. In a first phase, until July 2003 it partecipated to the SPD project, studying the radiation damage effects for the electronic microchip, crucial for the reliability of the detector. The possibility of using the SPD for a Fast Multiplicity Trigger in ALICE was investigated by the Group. SPD's were also used in the NA57 experiment at CERN-SPS to study strange and multistrange baryon production in fixed target Lead-Lead collisions.
Since August 2003, the Rome Group partecipates to the construction of the SDD's . The main contribution was focused on the production of the Front End Electronics. A Validation System for the hybrid Pascal and Ambra (analogue and digital) read-out chips (using a Semi-automatic Probe Station in a Class 100 Clean Room) operated in the Rome Laboratory since February 2005 until November 2006.
The Rome Group contributions on these items are reported in the Papers/Alice Notes/Conferences list.
|G. Bucci - S. Di Liberto|