We present the design of the trigger system for the KLOE experiment at the Frascati phi-factory DAFNE. The detector consists of a large volume drift chamber and a calorimeter both immersed in a 0.52 T solenoidal field. The trigger, structured with a first- and a second-decision level, is based on multiplicity of energy deposits in the calorimeter and of hits in the drift chamber. The selection criteria are described and the efficiency for detecting phi decays are evaluated with the data collected during the first runs.
M. et al. (Wed,) studied this question.