FPGA-Based Scaler DAQ upgrade for SpinQuest Experiment

The SpinQuest experiment at Fermilab aims to perform the first Sivers function measurement on sea quarks using the Drell-Yan process to find evidence for non-zero orbital angular momentum of light antiquarks in the nucleon. In particular, the SpinQuest spectrometer will detect pairs of positive and negative muons from Drell-Yan production on polarized nucleons. In order to accurately guage spectrometer performance as well as properly calibrate the trigger system, a scaler data acquisition system(DAQ) is required. The current scaler system utilizes 3 independent scaler modules, each with 32 inputs, and an interrupt module connected via the VMEBus. The upgraded design will consist of a single V1495 FPGA(field-programmable gate array) board used as a 128-input scaler module equipped with interrupt functionality. The design and current status of the FPGA-based scaler DAQ upgrade for the SpinQuest experiment will be presented.