基于ARM和FPGA的数字多道分析器研制  

Development of digital multichannel analyzer based on ARM and FPGA

作　　者：武旭东 麻金龙 段金松[1] 李婷[1] 王玮[1] WU Xudong;MA Jinlong;DUAN Jinsong;LI Ting;WANG Wei(Beijing Research Institute of Uranium Geology,Beijing 100029,China)

机构地区：[1]核工业北京地质研究院,北京100029

出　　处：《世界核地质科学》2024年第1期164-173,共10页World Nuclear Geoscience

摘　　要：多道分析器作为γ能谱测量中不可或缺的组件,其性能直接影响能谱仪分辨率及测量精度,传统的多道分析器多采用模拟电路方法或使用数字采集卡实现。模拟多道对于影响能谱仪性能的成形时间、脉冲通过率及死区时间修正等问题上具有一定的局限性,而这会直接影响能谱分析结果;数字采集卡是实现数字采集的计算机扩展卡,成本较高,不利于市场化推广。数字多道分析器对脉冲信号进行全数字采样,将其转化为数字量,利用数字信号处理方法,通过软件实现,完成整个信号分析处理过程,可极大提高系统稳定性与可靠性,相比于前两种方案,优势明显。设计了一款数字多道分析器,采用ARM处理器+高速ADC+FPGA的硬件方案,主要包括AD采样模块、FPGA数据处理模块和以STM32F4为核心的控制和通信模块。使用数字信号处理方法,编写硬件描述代码实现了脉冲信号滤波成型、幅值提取和基线修正等核脉冲处理的关键算法,最后给出探测器核信号经本文设计的数字多道处理后的γ能谱图。根据国内外研究成果及理论基础,经过深入系统理论分析,方法仿真验证,以及实际调试过程,最终研制出一款可商业化实用、完整且高精度的数字多道分析器,并将其应用在低本底γ能谱仪上,其能量分辨率测试均值为6.6791%,能量线性相关度R2在0.9999以上,积分非线性为0.26%。设计的数字化多道分析器采用ARM+FPGA的方式,极大程度降低了系统设计难度和成本,实现了高精度、高速的脉冲信号数字化,测试性能可达到数字采集卡的水平,具有极高的市场应用价值。As an indispensable component in gamma-ray spectrum measurement,the performance of the multichannel analyzer directly affects the spectrum analyzer’s resolution and measurement accuracy.Traditional multichannel analyzers often use analog circuit or digital acquisition cards for implementation.Multichannel analog analyzers have certain limitations in shaping time,pulse throughput rate,and dead time correction,which directly impact spectrum analysis results.On the other hand,digital acquisition cards,although capable of digital acquisition,But the manufacturing cost is high and it is not conducive to market promotion.Multichannel digital analyzer performs full digital sampling of pulse signal and converts it into digital quantities.The digital signal processing method realized by software improves system stability and reliability,presenting clear advantages compared to the aforementioned methods.In this paper,the design scheme of multichannel digital analyzer was proposed.The system consists of ARM processor,high-speed ADC,and FPGA,including AD sampling module,FPGA data processing module,and control and communication module with STM32F4 as the core.The key pulse processing algorithms such as pulse signal filtering,amplitude extraction,and baseline correction were realized.The gamma-ray spectrum processed by the multichannel digital analyzer designed in this paper is displayed.Based on domestic and research achievements and theoretical foundations,method simulation validation,and practical debugging,the commercially viable,complete,and high-precision digital multichannel analyzer was developed.It was applied to low-background gamma-ray spectrometer,and the performance parameters such as energy resolution,energy linearity,and integral nonlinearity were tested.The multichannel digital analyzer based on the ARM+FPGA combination significantly reduced system design complexity and costs.But has high-precision,high-speed digitalization of pulse signals,with performance comparable to digital acquisition cards.The analyzer

关 键 词：模数转换器 现场可编程门阵列 多道脉冲分析器 基线修正 

分 类 号：TL822.6[核科学技术—核技术及应用]