Gießen 2007 – scientific programme

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HK: Fachverband Physik der Hadronen und Kerne

HK 28: Instrumentation und Anwendungen

HK 28.6: Talk

Wednesday, March 14, 2007, 12:30–12:45, B

Joint tests of ALICE TRD Track Matching Units and Front End Electronics — •Felix Rettig für die ALICE TRD Kollaboration — Kirchhoff-Institut für Physik, Universität Heidelberg

The Transition Radiation Detector (TRD) is one of the main detectors of the ALICE experiment at the LHC. One of its primary objectives is to trigger on high momentum electrons. Based on data from 1.2 million analog channels, event reconstruction must be performed within 6 µs to contribute to the Level-1 trigger decision.
A hardware architecture has been developed to achieve the processing in the required time by means of massive parallelism. Analog data preprocessing, track segment detection and parametrization is performed by the front end electronics. Optical multi-gigabit links providing a total bandwidth of 2.7 TBit/s transfer parametrization data to the Global Tracking Unit (GTU) with tight latency requirements. The GTU reconstructs tracks from up to 20000 segments, calculates particle momenta based on track curvatures and produces the trigger contribution. In case of a Level-1 accept, compressed analog data is shipped to and buffered in the GTU for transmission to the data acquisition system. The GTU consists of 108 dedicated CompactPCI boards based on Xilinx Virtex-4 FX chips which offer integrated multi-gigabit deserializers, sufficient logic resources as well as PowerPC cores for monitoring purposes. A number of TMU prototypes were built and joint tests with the detector’s first supermodule conducted at CERN. This presentation focuses on the data shipping and buffering system with its low latency requirements and summarizes the current test results.