Data acquisition architecture and online processing system for the HAWC gamma-ray observatory-猫眼课题宝

HAWC伽马射线天文台数据采集架构及在线处理系统

DOI：

10.1016/j.nima.2018.01.051

发表时间：

2018

期刊：

Detectors and Associated Equipment

影响因子：

通讯作者：

中科院分区：

文献类型：

作者：

Abeysekara, A.U.;Alfaro, R.;Alvarez, C.;Álvarez, J.D.;Arceo, R.;Arteaga-Velázquez, J.C.;Ayala Solares, H.A.;Barber, A.S.;Baughman, B.M.;Bautista-Elivar, N.

高空水切伦科夫天文台（HAWC）是为TeV伽玛射线天文观测而设计的空气阵雨阵列。HAWC位于海拔4100米的墨西哥Sierra Negra。HAWC由300个水切伦科夫探测器组成，每个探测器配有4个光电倍增管（pmt）。HAWC重用Milagro实验中的前端板来接收PMT信号。这些电路板与时间到数字转换器（tdc）结合使用，以记录每次PMT命中（光闪）的时间和光量。一组VME TDC模块（每个128通道）以连续（无死区）模式运行。tdc由单板计算机（sbc）通过VME总线读出，sbc又连接到千兆以太网。整个系统产生约500mb /s的原始数据。设计并构建了高通量数据处理系统，实现了实时数据分析。该系统依赖于现成的硬件组件、用于数据传输的开源软件技术（ZeroMQ）和用于数据分析的定制软件框架（AERIE）。多个触发和重建算法可以组合在一起，并以并行方式在数据块上运行，产生一组输出数据流，可以以最小的延迟（< 5秒）实时分析。本文概述了该系统的硬件构成，并对软件设计进行了深入的描述，包括TDC数据采集系统和实时数据处理系统。并对这些系统的性能进行了讨论。

Abstract The High Altitude Water Cherenkov observatory (HAWC) is an air shower array devised for TeV gamma-ray astronomy. HAWC is located at an altitude of 4100 m asl in Sierra Negra, Mexico. HAWC consists of 300 Water Cherenkov Detectors, each instrumented with 4 photomultiplier tubes (PMTs). HAWC re-uses the Front-End Boards from the Milagro experiment to receive the PMT signals. These boards are used in combination with Time to Digital Converters (TDCs) to record the time and the amount of light in each PMT hit (light flash). A set of VME TDC modules (128 channels each) is operated in a continuous (dead time free) mode. The TDCs are read out via the VME bus by Single-Board Computers (SBCs), which in turn are connected to a gigabit Ethernet network. The complete system produces≈ 500 MB/s of raw data. A high-throughput data processing system has been designed and built to enable real-time data analysis. The system relies on off-the-shelf hardware components, an open-source software technology for data transfers (ZeroMQ) and a custom software framework for data analysis (AERIE). Multiple trigger and reconstruction algorithms can be combined and run on blocks of data in a parallel fashion, producing a set of output data streams which can be analyzed in real time with minimal latency (< 5 s). This paper provides an overview of the hardware set-up and an in-depth description of the software design, covering both the TDC data acquisition system and the real-time data processing system. The performance of these systems is also discussed.