A Fast Track Finding Trigger Processor For The Bes Detector

The Beijing Spectrometer (BES) is being designed and constructed for use at the Beijing 2 × 2.8 GeV center-of-mass energy electron-positron collider (BEPC). The BES detector will have approximately 20 K channels of electronics, and the beam collision rate will be 1.25 MHz, corresponding to a luminosity of 10 30 −10 31 cm −2 s −1 . A fast programmable track finding processor to be used in the second level trigger is described. This processor, mainly consisting of 3 out of 4 logic and track finding logic, is simple and flexible. Only 96 pieces of 4K × 1 bit random access memory (RAM) chips are used for the track finding logic on 4 layers of the main drift chamber.