A Very High Event Rate Data Acquisition System in Fastbus

A very high event rate Data Acquisition System is described. This DAS is planned for NA36, an SPS heavy ion experiment at CERN that uses calorimetry, wire chambers and a TPC to look for strangeness production enhancement as a signature of the quark-gluon plasma. Because of the high multiplicity final states and the fact that such states have never been seen, real time event selection is impractical and the DAS must record unusual amounts of data. The purpose is to organize and record 1000 events of 20 K byte average size during the 2 sec beam spill and to archive these events during the 10 seconds between spills. Full scale system testing is scheduled for June 1986, so considerable use of FASTBUS modules, developed at other institutions, is made in this design. The overall system block diagram is shown in Fig. 1.