【作者】 周文雄；

【导师】 王彦瑜； 魏宝文；

【作者基本信息】 中国科学院研究生院（近代物理研究所） ， 核技术及应用， 2014， 博士

【摘要】 目前加速器和核物理实验室所用的数据获取系统大多基于CAMAC、FASTBUS、VME、PXI等结构。这些系统专为大中型核物理实验建造，系统复杂且成本高，需专人维护运行，灵活性差。但在加速器束流诊断、小型核物理实验以及探测器刻度测量等应用中，小型便携式多参数数据获取系统即可胜任。鉴于此，我们研制了一款既方便携带又易于扩展的小型多参数数据获取系统。该数据获取系统在设计中有如下的创新：1、使用自定义的软总线，其传输速率为33MB/s,完全能满足模块级联时的速度要求。2、FPGA和ARM间通信使用SROM通信逻辑，其理论传输速率可以达到66.5MB/s，解决了FPGA和ARM进行数据传输的瓶颈。3、系统设计成便携设备，而且能够完成多参数测量。4、完全自主知识产权的软件处理系统。本论文主要对该系统的设计进行了详细讨论。主要叙述问题有：前端峰值保持电路的设计、自定义软总线的设计、FPGA与ARM之间的高速通信、配套数据获取软件的设计等。论文对该系统的介绍可以概括如下：第1章详细介绍了研制该系统的背景，并对现有的主流数据获取系统进行了总结，最后对该系统的研制过程中需要解决的主要问题进行了说明。第2章是对该系统的硬件设计进行详细的介绍。首先对整个系统的整体设计结构进行详细的分析；其次叙述了在设计中为了提高FPGA与ARM之间的通信速率所采取的方法；然后对现有的峰值保持电路的问题进行了总结，并给出了改进方案；最后对软总线的设计进行了详细的介绍。第3章介绍了系统中的时序逻辑设计。在该便携式数据获取系统的设计中，FPGA用于协调多个功能模块工作。在其逻辑设计中涉及到多种时钟信号的处理，这就必须要求处理好异步信号通信。该部分时序的处理对系统的稳定性很重要，如果不处理好将导致竞争冒险和亚稳态。为了解决这些问题，本章介绍了各种信号同步和时钟统一的方法。最后对系统中时序要求最高的背板总线和FPGA与ARM间通信逻辑进行了详细的介绍。第4章是本系统软件部分的介绍。在该系统的设计中，每一个硬件都包含一个嵌入式的计算机ARM，该计算机运行Linux操作系统，所以首先需要对ARM进行驱动设计和服务器程序的设计。另外，整个数据获取系统需要后端数据获取软件配合才能够完成数据的传输和存储。除此以外，为了保证后期方便的对存储的数据进行分析，也为了保证数据在传输过程中的稳定可靠，需要设计一个健全的帧结构和一个信息完整的存储格式。本章主要解决上面所叙述的问题。第5章是对数据获取系统的后期数据进行处理。由于环境噪声、系统误差等原因，最终得到的数据和真实值之间有一定的区别。为了消除这些区别，也为了分析数据的方便，本章介绍了一些核数据处理的方法。第6章是实验验证部分。首先在实验室对该系统的积分非线性、分辨率参数进行了测量。然后在真实的实验中，对能谱进行了测量并与成熟的数据获取系统进行了对比。第7章是对工作的总结，以及对该系统未来的展望。更多还原

【Abstract】 Nowadays, most of the DAQ(Data Acquisition) systems used in accelerator andnuclear physics areas are based on CAMAC, FASTBUS, VME or PXI structure. Thesesystems are specially built for large medium-sized physical experiment terminals likeBEPCIII or ATLAS. Due to the system’s complexity and high cost, these DAQ systemsneed really special care and maintenance, so they cannot be easily pushed to otherapplications. But in the accelerator beam diagnostics, small physics experiments anddetector calibration measurements, small, portable, multi-parameter DAQ system can befully adequate. Based on these reasons, we developed a kind of small, both easy to carryand extend multi-parameter DAQ system.The DAQ system has the following advantages:1. A self-designed bus system is used in this DAQ system. Its max data transmissionspeed is33MB/s which can meet the need of the DAQ system working in cascade mode.2. The SROM communication logical is used as the communication method betweenARM and FPGA. Its speed, which is66.5MB/s, can meet the requirements of the datatransmission from FPGA to ARM.3. The DAQ system is designed as a portable device, and it can be used to measuremultiple parameters at the same time.4. A DAQ software, with proprietary intellectual property rights, is developed for theDAQ system. This dissertation mainly describes the detail procedures of the design for theportable DAQ(PDAQ) system including the design of the peak detect and hold circuit,the design of the flexible bus, the communication method between the FPGA and theARM, the design of the PDAQ software and the data processing. The main content of thisdissertation is summarized as follows.The first chapter focuses on the background of the DAQ systems. It introduces themain DAQ systems used in nuclear physics laboratories. And then it shows the keyproblems that we must solve in the design of the PDAQ system.The second chapter focuses on the design of the hardware parts for the PDAQsystem. Firstly, it introduces the architecture of the PDAQ system. Secondly, it describesthe hardware design for the communication between the FPGA and the ARM. And then,it shows the disadvantages of the old peak detect and hold circuit, and provides a newcircuit for this PDAQ system. At last, it introduces the bus design of the system.The third chapter focuses on the logic design of the PDAQ system. The FPGA isused to coordinate the working of the circuits in the system. And many clock signals withdifferent frequencies are used in different function modules. So we must synchronizesignals from different clock systems, or the system will be unstable and the metastablestate will happen. In order to solve these problems, this chapter introduces many methodsof signal synchronization and clock unifying. Finally, this chapter describes the logicdesign of the bus and the communication method design between the FPGA and the ARM,which are the most important parts in the system.The forth chapter focuses on the design of the software for the PDAQ system. Thereis an embedded computer (ARM) in the PDAQ system. And the computer runs Linuxoperation system. So we must design the driver program and server program for the ARM.Besides that, the PDAQ software, running in the backend computer, is needed for datatransmission, processing and storage. In order to ensure the correctness and reliability of the data transmission, a frame and a data storage structure are designed for the system.The fifth chapter focuses on the processing of the nuclear experiment data. Itintroduces the methods for the background eradication, the noise filtering, the spectrumsmoothing, the gold deconvolution, the peak searching and the peak area calculate.The sixth chapter focuses on the test and verification. It introduces the test of thelinear and the precision for the system. And then it introduces a real nuclear experiment,which is measuring the energy spectrum of the Na22, comparing with the CAMACmodule PHILLIPHS7164.The seventh chapter is the summary and the outlook.更多还原