Bonn 2010 – scientific programme
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HK: Fachverband Physik der Hadronen und Kerne
HK 48: Instrumentierung VIII
HK 48.4: Talk
Thursday, March 18, 2010, 14:45–15:00, HG VIII
The Pretrigger System for the ALICE Transition Radiation Detector — •Jörg Lehnert1, Jochen Klein2, Tobias Krawutschke3, Ken Oyama2, Rainer Schicker2, and Stefan Schmiederer2 — 1Institut für Kernphysik, Goethe-Universität Frankfurt — 2Physikalisches Institut, Universität Heidelberg — 3Fachhochschule Köln
The Transition Radiation Detector (TRD) of the ALICE experiment at the CERN Large Hadron Collider (LHC) provides electron identification and tracking in the central barrel as well as fast triggering (6μs). The frontend electronics (FEE) consisting of 75000 multichip modules has a total power consumption of less than 65kW by keeping the digital electronics in a low power mode after processing an event. A fast wakeup signal for the FEE within 400ns after an interaction is needed to capture the TRD drift signals over the full time range and to ensure a low latency of data processing.
A dedicated hardware system provides this so-called pretrigger signal based on the direct analog or digital signals from the fast ALICE subdetectors TOF, V0 and T0 or the LHC bunch counter. Specific hardware components are mounted inside the L3 magnet close to the respective detectors to minimize signal propagation delays. Pretrigger algorithms employing conditions on multiplicities and geometrical coincidences are implemented in field programmable gate arrays.
We will describe the setup of the pretrigger system and report on its performance during operation of the ALICE TRD in pp collisions since Nov. 2009. This work is supported by BMBF and GSI.