A fast and programmable trigger processor for ring image Cherenkov detectors

A systolic processor array has been developed as a second level trigger for RICH detectors. A pattern recognition of the two-dimensional readout image is performed within 45 mu s. In a multistep correlation process, distant e/sup +/e/sup -/ pairs are recognized and close rings (e.g., from photon conversions) are rejected. The processor is built up with 28500 processing elements which are integrated in 440 VLSI chips. The trigger efficiency for open pairs in p-nucleus collisions is 68% with a rejection factor of 100.<
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