基于FPGA的数字化多道脉冲幅度分析器设计与实现

发布时间：2018-04-12 00:13

本文选题：FPGA + 数字多道脉冲幅度分析器　；参考：《东华理工大学》2015年硕士论文

【摘要】：核能谱测量的方法广泛应用于资源勘探、航空航天、环境监测以及基础科学研究等领域中。多道脉冲幅度分析器作为构成核能谱检测系统的核心部件,对系统的性能起着至关重要的作用。伴随着技术的进步,以及高性能的A/D和信号处理器的出现,数字多道仪器因其在能量分辨率、稳定性等诸多方面的优势,逐渐取代传统的多道脉冲幅度分析器,成为发展的趋势。虽然国内的研究机构对数字多道进行了多年研究,但与国外的产品相比,还有较大差距。因此,进一步研究和设计出性能优越的数字多道脉冲幅度分析器,意义重大。本论文采用Actel公司的型号为A3P250的FPGA芯片(作为数字信号处理的核心单元)和AD公司的型号为AD9235的模数转换器(作为核脉冲的模数转换模块)的组合,作为数字多道脉冲幅度分析器的设计方案。在FPGA中完成了所有信号处理和控制外围器件相关的功能,包括:控制A/D采样,时钟分频,高斯成形,幅值提取,RAM的读写,谱线的生成,串口数据的传输及485转换芯片的控制等。为了保证数据的远距离稳定传输,采用了RS485通信方式进行仪器与上位机之间的传输,芯片采用LTC2850。上位机软件(包括:谱线分析软件,波形分析软件和SD码计算软件)采用VB 6.0进行设计,其中串口通信功能通过MSComm控件的On Comm事件来实现。在将整个系统的软硬件系统实现之后,选用137CS,40K和232Th三种辐射源,对系统的能量分辨率、能量线性度和峰位漂移三项性能指标进行测定。实验数据表明,设计的数字多道脉冲幅度分析器的功能,达到预期目标。
[Abstract]:Methods the nuclear spectrum measurement is widely used in resource exploration, aerospace, environmental monitoring and scientific researches. The multi-channel pulse amplitude analyzer as a core component of nuclear spectrum detection system, plays a vital role in the performance of the system. Along with the technical progress, and the emergence of high performance A/D and signal processor the digital multi-channel instrument because of its energy resolution, stability and many other advantages, gradually replaced the traditional multi-channel pulse amplitude analyzer, become the trend of development. Although the domestic research institutions digital multi-channel studied for many years, but compared with foreign products, there is a large gap. Therefore, further research and design performance the advantages of digital multi-channel pulse amplitude analyzer, of great significance. This paper uses Actel's FPGA chip model A3P250 (as digital signal processing The core unit) and AD's type AD9235 ADC (analog-to-digital conversion module as a nuclear pulse) combination, as the design scheme of digital multi-channel pulse amplitude analyzer. In FPGA completed all the signal processing and control functions, the peripheral device comprises control A/D sampling clock frequency, Gauss forming the amplitude, extraction, RAM read and write, spanning the spectrum, serial data transmission and 485 conversion chip control. In order to ensure the stability of long-distance data transmission, using RS485 communication mode of transmission between instrument and computer chip, using LTC2850. software (including: spectrum analysis software, waveform analysis the software code and SD calculation software) VB 6 were used to design the serial communication function of MSComm control through the On Comm event to achieve. After using 137CS, the software and hardware of the system is 40. The three sources of K and 232Th are three energy indexes, including the energy resolution, the energy linearity and the peak drift. The experimental data show that the designed multi-channel pulse amplitude analyzer achieves the desired goal.

【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN791;TL81

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