HARDWARE TRIGGER SYSTEM FOR FERMILAB E866

E866 is the fourth experiment to be performed with the Fermilab Meson East spectrometer. Originally constructed in 1980 for E605, this spect rometer has since been used for E772 and E789. During these three expe riments, the hardware trigger depended on components dating from the e arly 1970s. The trigger system was rebuilt for E866 to improve its rel iability and increase its flexibility. The new system incorporates sev eral new modules designed and built specifically for this experiment. Notably, a custom Track Correlator combines the features of a 16-bit m emory lookup and a 12-bit: prescaler into a single extremely fast CAMA C module. The new hardware trigger system and modules are described, a nd the system performance during E866 is discussed. (C) 1998 Elsevier Science B.V. All rights reserved.