NEW DEVELOPMENTS FOR THE ALICE TRIGGER

The addition of a Transition Radiation Detector (TRD) to the ALICE setup, coupled with a better understanding of the requirements of the front-end electronics, have led to a major re-appraisal of the central trigger system for the ALICE detector. The previous system was reviewed at the LEB Workshop in 1996. In the new system, the principal rate reduction in Pb-Pb collisions comes after 5.5 microseconds, in order to wait for the decision of the TRD. Data transfer to the data acquisition system is initiated after a positive level 2 decision, 100 microseconds after the event takes place.