The SeaQuest experiment (Fermilab E906) detects pairs of energetic {\mu}+ and {\mu}- produced in 120 GeV/c proton-nucleon interactions in a high rate environment. The trigger system consists of several arrays of scintillator hodoscopes and a set of field-programmable gate array (FPGA) based VMEbus modules. Signals from up to 96 channels of hodoscope are digitized by each FPGA with a 1-ns resolution using the time-to-digital convertor (TDC) firmware. The delay of the TDC output can be adjusted channel-by-channel in 1-ns steps and then re-aligned with the beam RF clock. The hit pattern on the hodoscope planes is then examined against pre-determined trigger matrices to identify candidate muon tracks. Information on the candidate tracks is sent to the 2nd-level FPGA-based track correlator to find candidate di-muon events. The design and implementation of the FPGA-based trigger system for SeaQuest experiment are presented.
@article{arxiv.1509.04864,
title = {FPGA-based trigger system for the Fermilab SeaQuest experiment},
author = {Shiuan-Hal Shiu and Jinyuan Wu and Randall Evan McClellan and Ting-Hua Chang and Wen-Chen Chang and Yen-Chu Chen and Ron Gilman and Kenichi Nakano and Jen-Chieh Peng and Su-Yin Wang},
journal= {arXiv preprint arXiv:1509.04864},
year = {2015}
}