DAQ-121 – High-Speed Digitizer

The DAQ-121 is a high-performance, fully integrated digitizer developed by Nuclear Instruments for advanced SiPM-based muon detection systems. Designed to operate in demanding scientific environments, such as the ISIS Muon Facility, the DAQ-121 provides real-time digitization, processing, and streaming of high-speed analog signals from up to 32 channels simultaneously.

Key Features

• Compatible with Sci-Compiler for easy integration and development
• 32 independent analog input channels
• 12-bit ADC @ 1 GSPS per channel
• 2 GHz analog bandwidth
• Fully differential RJ45 analog inputs
• Real-time signal processing and data reduction
• Embedded Linux system on Zynq Ultrascale+ SoC
• 4× ARM 64-bit cores per module + Kintex-7 master FPGA
• Integrated power and bias control for SiPM detectors
• High-speed data streaming via Kafka and ZeroMQ
• EPICS & IBEX integration

System Architecture

Each DAQ-121 module integrates:

• 4 DAQ boards, each handling 8 channels and controlled by a Zynq Ultrascale+ SoM
• 1 master Kintex-7 FPGA aggregating and routing data
• 4× SFP optical transceivers for future optical data links
• 1 Gbps Ethernet link per board for data and control
• Integrated display for IP and voltage monitoring
• Multiple synchronization and I/O interfaces (TTL LEMO, LVDS, RJ45)

Block Diagram of the DAQ-121 system architecture. Each module integrates 4 DAQ boards, each handling 8 channels and controlled by a Zynq Ultrascale+ SoM.

Block Diagram of the DAQ-121 system architecture. Each module integrates 4 DAQ boards, each handling 8 channels and controlled by a Zynq Ultrascale+ SoM.

Block Diagram of a DAQ board. Each board handles 8 channels and is controlled by a Zynq Ultrascale+ SoM.

Block Diagram of a DAQ board. Each board handles 8 channels and is controlled by a Zynq Ultrascale+ SoM.

Signal Acquisition & Processing

• Digitizer mode: waveform acquisition on trigger (external/internal/periodic) with pre-trigger buffer up to 4 µs and post-trigger up to 120 µs
• PHA mode: real-time multichannel spectrum analysis between acquisition cycles
• Processing algorithms: exponential deconvolution, peak detection, digital CFD, timestamp extraction
• Max processed event rate: >10 MHz per channel

Calibration & SiPM Monitoring

• Real-time SiPM dark count spectrum analysis via embedded derivative trigger and QDC core
• Photon quantization and spectrum per channel
• Active gain stabilization via digital feedback and programmable bias control
• Remote access to per-channel temperature, bias, and heater status

Applications

• Muon spin rotation and relaxation (μSR)
• Time-resolved spectroscopy
• Neutron and gamma detection with SiPMs
• Custom detector readout in high-rate environments