The Central Data Acquisition Trailer


The trailer receives a timing signal from each detector when a hit is registered. The trailer coincidence circuit is triggered by hits in 3 detectors concurrently. A coincidence causes a train of clock pulses to be sent to all the detectors. This shifts the data serially from their shift register memory to the trailer in 70 microseconds. The time of the trigger, accurate to 1 millisecond, is recorded along with the rest of the trigger's data. Single track muon data are stored at a average rate of 2400 muons per second. The bulk of the data stored is of this form (lover energy band). The data is stored on a large external disk which holds several months of data. The 80% Argon, 20% CO2 gas bottles that feed into the detectors are visible at the middle of the trailer. Hut No. 54 is open for inspection. Project GRAND is located just north of the Notre Dame campus.


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