Session 4WCA: Data Acquisition System I

New solutions for data acquisition and analysis at FRIB

The Facility for Rare Isotope Beams (FRIB) is a world-leading user facility for the study of rare isotope beams using the in-flight fragmentation method. The unprecedented potential discovery of a modern rare isotope beam facility, such as FRIB, can only be realized by implementing state-of-the-art experimental equipment capable of studying these isotopes at a high beam rate and high performance. The increase in complexity of experimental setups and triggered data rates introduced the opportunity to upgrade the supported data acquisition (DAQ) and data analysis frameworks, and more in general, the computing capabilities to sustain both online and offline analysis at speed that let the experimenters make decision in real time. Hardware and software solutions are being explored and new tools have been developed. This talk will summarize the state of the art of the DAQ system at FRIB and directions for the future.

This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics and used resources of the Facility for Rare Isotope Beams (FRIB) Operations, which is a DOE Office of Science User Facility under Award Number DE-SC0023633.   

Standardization of trigger-less data-streaming DAQ system in Japan

In particle and nuclear physics experiments, development and standardization of a data acquisition (DAQ) system being scalable from small- to large-scale experiments has great benefit for sharing development resources and improving maintainability in future. To standardize the system, we need to overcome the difference in the trigger system in each experiment.

Recently, a trigger-less data-streaming type DAQ system, which does not require a hardware trigger, spread rapidly through our research field owing to the development of computer technologies. Thus, we are developing the trigger-less DAQ system that is suitable for the standard. The standard system should be simple, scalable, and independent from specific requirements from each experiment. For this purpose, we have developed a simple and lightweight clock synchronization system called MIKUMARI and data-streaming type high-resolution time-to-digital converter (TDC) with a timing resolution of 20 ps. This system provides the clock synchronization independently from accelerator timing and Plug and Play of front-end electronics. 

The trigger-less DAQ system requires the software-based event reconstruction and selection, and thus, multi-process-based load balancing is essential for the DAQ software. We have developed a next generation DAQ software called NestDAQ, which supports the semi-automatic generation for multi-end connection topology and load balancing.

 In this talk, we would like to report features of our system and beam test results so far and discuss future prospects.   

The sPHENIX Data Acquisition System - the Experiment's first Run in 2023

By the time of this workshop, the sPHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) will have completed its first data taking run, which has started in the second half of May. The experiment saw its very first collisions on May 18, 2023. sPHENIX is the first major upgrade to a Nuclear Physics experiment in the US in 2 decades, and will take data until the RHIC era ends with the start of the construction of the Electron-Ion Colllider.

The Data Acquisition System of sPHENIX is designed for event rates of 15 KHz. The largest data volume is produced by the tracking system, consisting of a Monolithic-active-pixel Vertex Detector (MVTX), an Intermediate Tracker (INTT), and the Time Projection Chamber (TPC). In order to achieve the design event rate, the entire tracking system will be read out in continuous, or streaming mode. The resulting continuously sampled signals from the tracking system must then be processed and correlated with the actually triggered data from the calorimeter system. Due to budget constraints, it was not possible to upgrade the entire readout, including the calorimeter systems, to a streaming-based one. However, by operating the entire tracking system in streaming mode, it will be possible to acquire tracking data without the calorimeters at a faster rate, which will benefit our heavy-flavor physics program under most running conditions.

At the time of this writing, we have commissioned the major parts of the data acquisition system, such as most readout systems for the various detector components, the Timing System, and most of the hardware of the Local-Level-1 Trigger system, and are now commissioning the detectors with beam. During the current commissioning phase we already routinely use physics-type signals, such as π⁰ invariant mass spectra and detector correlation plots, to evaluate the detector performance and calibrations.

We will give an overview of the sPHENIX experiment, its detector systems and their readout, and present the performance during data taking, the achieved statistics, and especially the state of combining the streaming readout of the tracking detectors with the triggered readout of the calorimeters and the Minimum-Bias Detector.