Speaker
Description
The Next Enriched Xenon Observatory (nEXO) experiment aims to search for Neutrinoless Double Beta Decay in liquid xenon. To meet the stringent scientific goals and requirements of the experiment, the nEXO Data Acquisition (DAQ) system is designed to handle high data rates, ensure precise timing, and support operations over a 10-year active measurement period at SNOLAB. The DAQ system collects and processes data from 3,840 charge channels and 7,680 photon channels. The architecture utilizes Commercial Off-The-Shelf (COTS) hardware to mitigate development risks and reduce costs. The DAQ hardware consists of a single, compact rack-mounted server equipped with a high-performance FPGA PCIe card for data and configuration links to front-end boards, lossless real-time data compression, and on-board multi-gigabyte data stream buffering. Precision Time Protocol (PTP) provides timing synchronization with an accuracy of less than 500 nanoseconds, ensuring relative clock alignment across the entire experiment for all subsystems with respect to the SNOLAB timing system. The software framework is based on the Maximum Integrated Data Acquisition System (MIDAS) DAQ, offering a web-based control interface and integrated support for various hardware components. Trigger logic in the FPGA PCIe card is implemented to filter events based on charge and photon signals, reducing the raw data bandwidth to manageable levels during physics data taking. We will present this DAQ conceptual design and discuss some of the critical requirements that are driving many design decisions in the DAQ firmware and software architecture.
