The proposed level-3 trigger system for STAR

The level-3 trigger system of the STAR experiment will in the final stage consist of a farm of 24 ALPHA/Linux processors, interconnected by SCI (Scalable Coherent Interface). The system will perform online tracking of N/sub track//spl ges/8000 tracks per event (N/sub point//spl les/45 per track). The track data will be transferred to a global level-3 CPU (expected data transfer rate /spl sime/48 MB/s), performing online event analysis tasks (e.g. invariant mass reconstruction) with a design trigger input rate of R=100 Hz (R=20 Hz for a prototype system).