FPGA-based trigger system for the Fermilab SeaQuest experiment

TL;DR

This paper presents the design and implementation of an FPGA-based trigger system for the SeaQuest experiment at Fermilab, enabling real-time detection of muon pairs in a high-rate environment using FPGA modules and TDC firmware.

Contribution

It introduces a novel FPGA-based trigger system with 1-ns resolution TDCs and real-time track identification for the SeaQuest experiment.

Findings

Achieved 1-ns timing resolution for muon detection

Successfully identified candidate muon tracks in real-time

Enhanced trigger efficiency in high-rate conditions

Abstract

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.