基于DSP的核信号波形数字化获取与处理系统设计

介绍了一种基于DSP的高速核信号波形数据采集与处理系统的软硬件设计及实现,并给出了在不同条件下的采样结果.     

核信号数值仿真方法的研究及应用

提出并建立了一种数值仿真方法,通过计算机模拟,生成各种数字化核信号波形,以此作为工具开展核信号数字处理方法的研究.通过准高斯滤波、梯形滤波和匹配滤波算法对数字核信号处理结果的研究与比较表明,提出的方法是准确而可行的.     

一种实用的工业核仪表信号处理方法

针对工业核测量的特点,设计了一种实用的核测量信号数字处理方法,以减少工业核仪表测量统计误差,改善动态响应性能.所设计的算法采用单片机实现,在γ射线液位计中的应用结果表明了该方法的有效性.     

A beam position measurement system of fully digital signal processing at SSRF

This fully digital beam position measurement instrument is designed for beam position monitoring and machine research in Shanghai Synchrotron Radiation Facility. The signals received from four position-sensitive detectors are narrow pulses with a repetition rate up to 499.654 MHz and a pulse width of around 100 ps, and their dynamic range could vary over more than 40 dB in machine research. By the employment of the under-sampling technique based on high-speed high-resolution A/D conversion, all the processing procedure is performed fully by the digital signal processing algorithms integrated in one single Field Programmable Gate Array. This system functions well in the laboratory and commissioning tests, demonstrating a position resolution (at the turn by turn rate of 694 kHz) better than 7 μm over the input amplitude range of -40 dBm to 10 dBm which is well beyond the requirement.     

多功能网络化核数据获取和处理系统

应用网络技术将多个功能不同、相互独立的以PC微机为基础组成的核数据获取和处理子系统有机互联,组成了一种新型的多功能网络化核数据获取和处理系统,探讨了系统的最佳组成模式、工作原理及实现方法,给出了系统在2．5MeV静电加速器上进行团簇特性研究的初步结果。     

一种两用微机化核测量仪

介绍一种既可作氡的α射线测量,又可作γ射线测量的微机化智能核测量仪,该仪器以P89C58单片机为核心微处理器,来完成数据采集、处理,电路控制,显示,通信等功能。利用P89C58对传统的完全基于硬件电路的单道脉冲幅度分析器进行了改进简化。     

碲锌镉探测器的数字核信号处理系统设计

设计了完整的碲锌镉(Cd Zn Te,CZT)探测器数字核信号处理系统,包含了低功耗偏压电源、低噪声电荷灵敏放大器、数字梯形多道脉冲幅度分析器及数字上升时间甄别器。在考虑探测器与后端数字多道优化匹配前提下设计了低噪声电荷灵敏放大器;数字多道脉冲幅度分析器(Digital Multi-Channel Pulse Height Analyzer,DMCA)通过高速模数转换器将模拟核信号离散化后,在现场可编程门阵列(Field Programmable Gate Array,FPGA)中实现数字核脉冲信号处理;FPGA芯片中以快慢双通道梯形成形器为核心,针对碲锌镉探测器空穴收集不完全的问题,设计了数字上升时间甄别模块,有效消除了空穴拖尾效应,显著提升碲锌镉探测器的能量分辨率。从实验结果可知,针对西北工业大学提供的4 mm×4 mm×2 mm的准半球结构碲锌镉探测器对241Am的分辨率最佳可达3.6%,对137Cs的分辨率可达0.96%。     

微型化双参数核谱数据获取与处理系统

本文叙述了一个以微型计算机为基础的双参数核谱数据获取与处理系统。主要特点是造价低,使用方便、谱形显示立体感较强。文中对数据获取通道和立体谱形显示作了较详细的描述,给出了应用实例。     

基于DSP的多通道波形取样电路设计

介绍了BESⅢ主漂移室电荷测量的多通道波形取样电路，该电路的采样频率为40MHz，由于采用了DSP，可以实时地对采样数据进行零压缩、扣台基、求电荷量、二次项修正等多项处理。整个系统采用流水线工作方式，减少了死时间。     

Implementation of a cusp-like for real-time digital pulse shaper in nuclear spectrometry

Pulse shaping,which improves signal-to-noise ratio excellently,has been extensively used in nuclear signal processing.This paper presents a cusp-like pulse-shaping technique developed through the recursive difference equation in time domain.It can be implemented in field programmable gate array hardware system.Another fiat-topped cusp-like shaper is developed to optimize the time constant of pulse shaping and reduce the influence of ballistic deficit.The methods of both baseline restoration and pile-up rejection are described.The 137Cs energy spectra measured with the digital cusp-like shaper are 6.6％ energy resolution,while those by traditional analog pulse shaper are 7.2％ energy resolution,under the same conditions.This technique offers flexibility,too,in adjusting the pulse shaper parameters.     

脉冲调制器稳定性监控中的数据采集与处理

设计采用反馈控制的方法改善脉冲调制器输出高压脉冲幅度稳定性,分析了实现稳定性目标对数据采集系统软、硬件的要求,介绍了相关的实验测试和信号处理方法。数据采集系统由Stratix ii FPGA开发板、AD6645、上位PC机组成,借用差分放大器提高测量分辨率。数据处理采用脉冲采样样本均值作为表征幅度的特征量,并采用平均、插值、数字滤波、BP神经网络等方法来提高幅度监测值的分辨率能力和抗干扰能力。     

Improvement of digital S-K filter and its application in nuclear signal processing

On the basis of preliminary studies, a novel duo-parameter model consisting of amplitude filter factor and frequency filter factor for low-pass S-K filter is presented in this paper. The model is established by applying numerical differentiation method. Some simulation experiments and real data tests are carried out to verify the feasibility and superiority of the new algorithm. The results show that this duo-parameter model of low-pass S-K filter can be used to achieve high performance in signal processing and nuclear spectrum smoothing.     

铀矿伽马能谱测井核脉冲信号数字化处理技术

在铀矿勘查中,可采用伽马能谱测井获取钻孔地层的铀、钍含量。相对于传统的模拟构架,基于数字化核脉冲信号处理技术构建的伽马能谱测井仪具有计数率高、信号噪声低和稳定性好等优点。通过采用核脉冲信号数字化处理技术,实现了伽马能谱的数字化采集,在放射性勘查模型井上进行了测试。混合模型的能谱测量铀、钍含量与标称含量的误差均小于5%,符合铀矿伽马能谱测井相关规范要求。     

核测量中数字示波器自动控制软件的研制

介绍了在大型辐射设备上进行的核测量工作中,数字示波器通用控制软件的研制以及其功能特点。此软件利用VC^ 6开发,基于Windows95／98操作系统,实现了利用单台PC机通过GPIB总线对多台数字示波器进行控制。同时讨论了开发过程中一些主要问题的解决方法。     

基于FPGA的DDS信号获取与PI反馈算法设计

介绍了上海质子治疗装置高频低电平系统中扫频配置和PI反馈控制算法。通过编写Verilog HDL代码对AD9858芯片进行配置,实现了直接数字频率合成和频率扫描的功能,设计了PI算法以保证高频腔腔压幅度和相位的高精度和高稳定性。     

基于VI技术的单探测器多辐射类型并行测量分析

基于虚拟仪器的概念,设计并构建了一套数字化辐射测量系统。使用该平台结合金硅面垒探测器进行了单探测器多辐射类型并行测量分析,以核辐射脉冲前沿时间为判据,将α、β辐射谱在一个系统里进行了有效分离。     

The development of data acquisition and processing application system for RF ion source

As the key ion source component of nuclear fusion auxiliary heating devices, the radio frequency(RF) ion source is developed and applied gradually to offer a source plasma with the advantages of ease of control and high reliability. In addition, it easily achieves long-pulse steady-state operation. During the process of the development and testing of the RF ion source, a lot of original experimental data will be generated. Therefore, it is necessary to develop a stable and reliable computer data acquisition and processing application system for realizing the functions of data acquisition, storage, access, and real-time monitoring. In this paper, the development of a data acquisition and processing application system for the RF ion source is presented. The hardware platform is based on the PXI system and the software is programmed on the Lab VIEW development environment. The key technologies that are used for the implementation of this software programming mainly include the long-pulse data acquisition technology, multithreading processing technology, transmission control communication protocol, and the Lempel–Ziv–Oberhumer data compression algorithm. Now, this design has been tested and applied on the RF ion source. The test results show that it can work reliably and steadily. With the help of this design, the stable plasma discharge data of the RF ion source are collected,stored, accessed, and monitored in real-time. It is shown that it has a very practical application significance for the RF experiments.     

数字化核测仪表的设计与算法分析

介绍了数字化核测仪表的设计与算法分析，给出了数字化核测仪表的工作原理，以及以单片机为核心的硬件、软件的实现方法、实现准则，以及对反应堆测量的一些算法分析。     

基于核电四极矩共振技术的爆炸物检测系统的数据处理及信号识别算法

分析了核电四极矩共振(NQR)信号的特点,利用傅里叶频谱分析对NQR信号进行处理的信噪比及其随测量时间的变化曲线,在此基础上,针对NQR信号提出一种具有更高信噪比的频谱分析方法(加权傅里叶频谱分析),同时提出一种可以有效区分NQR信号和正弦干扰信号的频谱差值分析方法。     

核电站机组故障诊断系统的知识获取

核电站机组故障诊断系统知识的获取和知识库的建立是影响诊断系统能否应用于实际的关键步骤。针对实现核电站机组故障诊断系统给出了知识获取的一种方法和步骤,使其有章可循,加强了在实际核电站中可操作性。按照文中提出的工作框架组织人员完成各项任务,可以最终完成核电站机组故障诊断系统知识库的建立。