Readout of the ALICE Transition Radiation detector
ALICE is the heavy ion expriment of the four large experiments of the Large Hadron Collider at the european centre for nuclear physics CERN, in Geneva. The goal of the Transition Radiation Detector (TRD) is the detection of electron/positron pairs with high transverse momentum. The tracks of these particles a only little bended within the magnetic field of the detector and thus are easy identifiable. But since approximately 16,000 particles are in the detector at the same time, about 1.2 million channels are needed, which all have to be digitized and computed in parallel.
The complete digital TRD trigger electronics is developed, including the development of a dedicated trigger processor ASIC, that seeks for tracks in realtime. About 75,000 of these processors will run in parallel. The special challenge is not only the huge channel number to handle but also the limited time for computation: to decide for a trigger may not take longer than 5 seconds, including the computation of all tracks.
The project provides further information on a separate home page ALICE - A Large Ion Collider Experiment.