Distributed digital data acquisition system with network time synchronization

Technical Report · Tue Jan 30 00:00:00 EST 2018

OSTI ID:1418690

Hennig, Wolfgang ^[1]

---

1. XIA LLC

Large scale nuclear physics experiments often use arrays of radiation detectors, which can be physically separated – in different rooms, near and remote to a target, and/or at different positions in the beam. To detect related events, time synchronization of the detector readout electronics is essential. In most existing large digital data acquisition systems, time synchronization is accomplished by sharing clock, trigger, and reset signals within and between chassis. This works well over short distances, but requires dedicated cabling and/or modules and becomes cumbersome for widely separated arrays. Recently, techniques and standards have been developed to synchronize time in network devices, for example the “Precision Time Protocol” (IEEE 1588) and the higher performance “White Rabbit” project. These techniques can reach low/sub-nanosecond time synchronization between processors. In this project, these techniques will be used to develop a practical, compatible, low cost product for nuclear physics applications, i.e. bringing the precision network timing to the front end data acquisition where detector pulses are detected, captured and timestamped. An existing detector readout module, the Pixie-Net, was adapted in hardware and firmware to tag detector events with timestamps derived from the network time synchronization techniques. It achieved time resolutions in the range of 1300ns to 200ps, depending on signal source, network, and synchronization technique. A concept for software triggering was developed, based on timestamped data rather than hard wired trigger pulses.

• Research Organization: XIA LLC
• Sponsoring Organization: USDOE Office of Science (SC)
• Contributing Organization: XIA LLC
• DOE Contract Number: SC0017223
• OSTI ID: 1418690
• Type / Phase: SBIR (Phase I)
• Report Number(s): DOE-XIA-0017223-1
• Country of Publication: United States
• Language: English