The Data Acquisition System of the LZ Dark Matter Detector: FADR

TL;DR

The paper details the design and implementation of the FADR system for the LZ dark matter detector, enabling real-time data acquisition, waveform analysis, and detector monitoring using FPGA technology.

Contribution

It introduces a novel FPGA-based architecture for data acquisition and real-time monitoring in a large-scale dark matter detector.

Findings

Successful digitization of 745 PMT signals at 100 MHz

Real-time waveform analysis and event selection implemented

Performance measurements demonstrate system reliability and efficiency

Abstract

The Data Acquisition System (DAQ) for the LUX-ZEPLIN (LZ) dark matter detector is described. The signals from 745 PMTs, distributed across three subsystems, are sampled with 100-MHz 32-channel digitizers (DDC-32s). A basic waveform analysis is carried out on the on-board Field Programmable Gate Arrays (FPGAs) to extract information about the observed scintillation and electroluminescence signals. This information is used to determine if the digitized waveforms should be preserved for offline analysis. The system is designed around the Kintex-7 FPGA. In addition to digitizing the PMT signals and providing basic event selection in real time, the flexibility provided by the use of FPGAs allows us to monitor the performance of the detector and the DAQ in parallel to normal data acquisition. The hardware and software/firmware of this FPGA-based Architecture for Data acquisition and Realtime monitoring (FADR) are discussed and performance measurements are described.