The E791 Parallel Architecture Data Acquisition System

TL;DR

The paper describes the design and implementation of a high-speed data acquisition system for the E791 experiment at Fermilab, capable of handling 20 billion events and recording 50 terabytes of data efficiently.

Contribution

It introduces a novel parallel architecture DAQ system with high throughput and large data storage capacity for particle physics experiments.

Findings

Recorded 20 billion physics events

Achieved data transfer rate of 9.6 MB/s

Stored 50 TB of experimental data

Abstract

To collect data for the study of charm particle decays, we built a high speed data acquisition system for use with the E791 magnetic spectrometer at Fermilab. The DA system read out 24000 channels in 50 uS. Events were accepted at the rate of 9000 per second. Eight large FIFOs were used to buffer event segments, which were then compressed and formatted by 54 processors housed in 6 VME crates. Data was written continuously to 42 Exabyte tape drives at the rate of 9.6 Mb/s. During the 1991 fixed target run at Fermilab, 20 billion physics events were recorded on 24000 8 mm tapes; this 50 Tb (Terabyte) data set is now being analyzed.