Continuous timing measurement using a data-streaming DAQ system
Continuous timing measurement using a data-streaming DAQ system
复制标题
使用数据流 DAQ 系统进行连续定时测量
DOI：
10.1093/ptep/ptab128
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发表时间：
2021
影响因子：
3.5
通讯作者：
Takahashi Tomonori
中科院分区：
文献类型：
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作者：
Honda Ryotaro;Aramaki Takashi;Asano Hidemitsu;Akaishi Takaya;Chang W C;Igarashi Youichi;Ishikawa Takatsugu;Kajikawa Shunsuke;Ma Yue;Nagai Kei;Noumi Hiroyuki;Sako Hiroyuki;Shirotori Kotaro;Takahashi Tomonori
我们在J-PARC研究了一个用于粲重子谱的原型无源数据采集（DAQ）系统。研制了一种专用的时间数字转换器（TDC），用于无外触发的连续定时测量。通过引入心跳方法，周期性地产生一个时钟信号，实现了1010量级的高动态范围的定时测量。基于消息队列应用程序编程接口（API）FairMQ，还开发了接收和过滤来自TDC的数据流的DAQ软件。我们测试了原型DAQ系统与探测器使用电子和正电子转换从韧致辐射光子束的速率条件高达1.9 MHz/1毫米探测器段。DAQ从六个TDC接收5.4 Gbps数据流，并将其合并为一个完整的数据集。在对数据的某一部分进行分类之后，软件响应于正电子或电子的穿透，使用时间轴上的检测器命中之间的时间间隔来搜索一组对应的数据片段，并去除不必要的命中。在测试条件下，在线计算能力需要大约25 GB RAM和25个CPU线程。在DAQ软件中未观察到无声数据丢失。
We have investigated a prototype triggerless data acquisition (DAQ) system for charmed-baryon spectroscopy at J-PARC. A special time-to-digital converter (TDC) dedicated to continuous timing measurement without any external trigger was developed. A high dynamic range of the order of 1010for the timing measurement was realized by introducing the heartbeat method, which periodically generates a delimiter datum. DAQ software receiving and filtering the data stream from the TDCs was also developed based on a message-queue application programming interface (API), FairMQ. We tested the prototype DAQ system with detectors using electrons and positrons converted from a bremsstrahlung photon beam with a rate condition of up to 1.9 MHz/1-mm detector segment. The DAQ received a 5.4 Gbps data stream from six TDCs and merged them to a complete data set. After sorting a certain portion of the data, the software searched for a set of corresponding data fragments in response to the penetration of a positron or electron using time separation between detector hits in the time axis and removed unnecessary hits. Around 25 GB RAM and 25 CPU threads were required for the online computing power under the test conditions. No silent data drop in the DAQ software was observed.