【作者】 董乐；

【导师】 郑国恒； 杨洁；

【作者基本信息】 郑州大学 ， 物理电子学， 2018， 硕士

【摘要】 随着核控制技术的发展,核物质的放射性特点被越来越多地应用于国防、工业、农业、医学、环境和材料等领域,如核能发电、矿藏探测、环境监测、医学成像等。在所有这些应用中,对核物质放射性的实时定量检测必不可少。近年来,数字电子技术和计算机技术的快速发展为数字核放射性检测系统的发展创造了有利条件。目前,国内外现有的核放射性检测系统多是单路模式,即在同一时间只能检测一路信号。而且,我国现有的检测系统仍存在体积大、精度低、效率低等一系列问题。因此,针对以上问题研究开发多路核放射性检测系统,对于提高核放射性的检测水平,意义重大。本文论述的多路核放射性检测系统的设计,以MaPMT芯片、Xilinx公司的可编程逻辑器件XC6SLX45和意法半导体公司推出的基于Cortex-M4内核的微控制器STM32F407IG作为主要器件。系统中MaPMT芯片的64路通道通过外接亚德诺公司的AD5323调节全局阈值;FPGA内部釆用VHDL语言设计实现脉冲信号的处理;STM32主要作为控制核心,对MaPMT芯片进行初始配置,同时作为FPGA和上位机通信的桥梁,与FPGA实现命令交互和数据传输,最后通过网络端口与上位机软件进行信息交互。系统采用ARM+FPGA的组合进行搭建,ARM比较适合于事务处理工作,用于系统的总体控制,FPGA的内部逻辑结构搭建灵活,管脚充足,用于多路数据信息的并行处理。该系统依据核电子学基本原理设计信号处理系统的单道脉冲幅度分析器,它是核放射性检测系统的重要组成部分。系统使用高集成度元器件替代传统的分立器件,有效减小了体积,降低了功耗。其内部构造了两个多路单道脉冲幅度分析器,可实现最多对64路探测器输入信号同时在两个能区检测分析。系统的硬件部分包括ARM、FPGA系统电路的设计,以及电源电路和网络接口电路的实现。软件设计包括ARM控制模块的软件开发和上位机测试软件的设计。通过对系统进行整体性能测试,包括各个通道的一致性,对比测试以及稳定性测试,经过数据分析表明,系统达到了预期的设计目标。更多还原

【Abstract】 With the development of nuclear control technology,the radioactivity characteristics of nuclear matter are increasingly applied in the fields of national defense,industry,agriculture,medicine,environment and materials,such as nuclear power generation,mineral exploration,environment monitor,and medical imaging and so on.In all these applications,real-time quantitative detection of nuclear material radioactivity is essential.In recent years,the rapid development of digital electronic technology and computer technology has created favorable conditions for the development of digital nuclear radiological detection system.At present,the existing nuclear radioactive detection systems at home and abroad are mostly single way mode,that is,only the signal of one channel can be detected at the same time.Moreover,the existing detection system in China still has a series of problems,such as large volume,low precision and low efficiency.Therefore,the research and development of multipath detection system of nuclear radioactivity is of great significance for improving the detection level of nuclear radioactivity.The design of multi-channel nuclear radioactivity detection system discussed in this paper is based on the MaPMT chip,the programmable logic device XC6SLX45 of Xilinx Company and the micro controller STM32F407 IG based on the Cortex-M4 kernel,which is the main component of the core.In the system,the AD5323 is used to adjust the global threshold of the 64 channel of the MaPMT chip,and the FPGA uses VHDL language to design and realize pulse signal processing.As the control core,STM32 made the initial configuration of the MaPMT chip.At the same time,as a bridge between the FPGA and the host computer,the command interaction and data transmission with the FPGA are realized.Finally,the information interaction between the network and the host computer software is realized.The system is built with the combination of ARM+FPGA,and ARM is suitable for transaction processing.It can be used in the overall control of the system.The internal logic structure of FPGA is flexible,and the pipe foot is adequate for parallel processing of multi-channel data information.Based on the basic principles of nuclear electronics,the system designs a single channel analyzer in signal processing systems.It is an important part of the nuclear radioactive detection system.The system uses high integration devices instead of traditional discrete devices,which effectively reduces the volume and reduces the power consumption.It constructs two multipath single channel analyzers,which can detect and analyze the input signals of 64 paths in two energy areas simultaneously.The hardware system includes the design of ARM and FPGA system circuit,and the realization of power supply circuit and network interface circuit.The software system includes the software development of the ARM control module and the design of the upper computer test software.Through the overall performance test of the system,including the consistency of each channel,the contrast test and the stability test,the data analysis shows that the system has achieved the expected design goal.更多还原