用于光谱和能级寿命测量的控制及数据获取电子学系统

简要介绍了为高电离态原子光谱学实验研究装置研制的控制及数据获取电子学系统。该系统主要用于光谱和能级寿命的测量控制与数据获取。     

光中子成像多路数据获取系统研制

研制了一套用于强X射线场下多路中子探测器信号处理和采集的数据获取系统。该系统接收探测器信号,分别对其做不同时间范围的积分,两个积分信号的幅度可用作波形甄别。采用现场可编程逻辑器件(FPGA)和硬件描述语言(verilog)实现对探测器和前端电路的测量控制,得到的数据经STM32微控制器控制传输给计算机。使用两种输入信号进行信号采集测试表明:该系统可正常地进行采集工作,得到的数据能够用于区分不同形状的信号。     

一维多道快电子能量损失谱仪的数据获取系统

介绍了用于一维多道快电子能量损失谱仪的数据获取系统。利用简单的与门电路,并配合DAQ2010采集卡的门控信号实现精确定时,利用定时卡PCI8554来同步采集卡和微机的动作,利用微机的RS232接口通讯来控制扫描电源,从而实现了谱仪的扫描测量。利用多线程技术,提高了采集系统的容错能力。该系统目前已经用在电子能量损失谱仪上,效果良好。     

高精度同步数据获取系统的研制

在磁铁电源研制等多种应用场合需同步测量多个信号,同时要求测量数据要有较高的精度。利用高精度模数转换器AD7960实现高精度数据获取,使用可编程门阵列(Field-Programmable Gate Array,FPGA)进行逻辑控制实现同步触发控制,研制出了高分辨率同步数据获取系统。分别针对高精度和同步性能进行测试和分析,得出系统的实际有效分辨率高于18位,并验证了系统能够实现高性能的同步数据采集。结合实际应用,进一步验证了系统的性能优势。     

MOLDASⅡ CAMAC多参数数据获取系统

MOLDASⅡCAMAC多参数数据获取系统是为重离子核物理实验能量、时间和多重性测量而设计的通用数据获取系统。该系统可以用于两类实验测量;(1)符合测量。由外部快电子线路快符合后产生一个触发信号进行;(2)多重性测量。由在本系统的多重器的面板上预置一个≤9的数字,则每个事件实际到来的参考数数目和预置数进行大于、     

磁质谱仪离子收集器数字化读出系统的研制

研制了一个用于磁质谱仪法拉第筒阵列离子收集器的高精度数字化读出系统，实现对离子束中离子成分的分析与诊断。数字化读出系统由前端处理电路和数据获取模块组成，前端处理电路采用门控积分器将418通道微弱电荷信号转换为电压信号，数据获取模块将电压信号数字化后，通过以太网接口将数据上传到远程上位机。该读出系统实现了电荷范围为0.1~120 pC的数字化读出，非线性误差小于1.95%（全量程）。现场应用测试结果表明，该数字化读出系统完全满足实验需求。该系统还可广泛用于核物理实验和加速器系统中微弱电流或电荷信号的测量。     

外热式等离子体实验装置数据获取和处理系统

介绍了外热式等离子体实验装置数据获取和处理系统的设计与实现。该数据获取和处理系统支持20通道差分信号采样,每通道最高采样率1Msps,基于USB2.0的数据接口的实时传输能力为10M Byte/sec,能够满足外热式等离子体实验装置等离子体流场采样测量的技术要求。     

回取分类系统α废物在线检测实验装置数据获取及处理系统的研制

回取分类系统α废物在线检测实验装置是废物库退役示范工程中的一个重要环节。它利用3He中子计数管测量传送带上废物中Pu同位素发射的中子数,从而确定废物中的含Pu量,达到检测α废物的目的。 针对系统在线检测的需求和测量系统输出信号的特点,数据获取及处理系统采用了两个ISA总线的标准PC插件、IPC5387计数/定时板和IPC5375功放输出板。通过软件编程完成了中子计数、处理、报警及与主控制台的报警联动控制功能,满足系统的实时控制需求。 经现场应用表明:该系统实现了测量数据的自动获取、处理及图形化显示;实现了废物     

同步辐射区光束线位置测量系统的控制和数据获取

介绍了上海同步辐射光源的X射线光束位置测量系统的控制和数据获取,具体描述了位置测量系统的控制和数据获取的总体设计、原理和软件系统,以及在上海同步辐射光源(SSRF)光束线线站的应用。     

4π BaF2装置的触发系统研究

设计了一套γ全吸收型BaF₂探测装置,用于中子辐射俘获反应截面的在线测量,其中信号测量部分采用了基于高速采集卡的数字化脉冲波形采集技术。并设计了一套触发系统,由触发单元产生的信号作为数据获取系统的外触发控制数据采集,以在数据测量过程中剔除绝大多数本底事件。触发系统采用了符合测量技术,通过多通道、多参数之间的符合测量,实现释放瞬发级联γ射线的中子俘获反应事件的判选和本底的剔除。本文对触发系统的电路设计和实验测试进行了阐述。     

1Cr18Ni9Ti焊缝疲劳短裂纹的形态演化

试验研究了1Cr18Ni9Ti焊缝光滑试样的单轴疲劳短裂纹形态演化规律.基于"有效短裂纹准则",把注意力放在"主导有效短裂纹(DESFC)"萌生及裂尖前沿区域.观测发现,ESFCs萌生于焊缝局部delta铁素体与奥氏体基质界面,取向在与加载轴垂直截面小于45°随机分布.之后,受微观结构约束,表面倾向于沿垂直于轴向不规则扩展;深度方向,裂纹初始与加载方向垂直,之后倾向于与柱状晶生长方向垂直.当若干取向基本一致,裂尖前沿相邻的ESFCs发生合并即形成真实DESFC,由微观结构短裂纹(MSC)阶段进入物理短裂纹(PSC)阶段.PSC阶段,表面DESFC近似与轴向垂直,在微观结构干扰下不规则扩展;深度方向,逐步演变与柱状晶生长方向垂直,后期及长裂纹阶段倾向于与加载轴成45°.最后,试样沿与加载轴垂直方向瞬时断裂.这说明了疲劳短裂纹与长裂纹形态变化具有明显差异.     

单光子分辨时间谱仪信噪比的研究

研究了单光子分辨时间谱仪的信噪比和影响信噪比的因素,探讨了降低本底干扰、提高探测效和信噪比的方法。结果表明,信噪比与探测器对源张的立体角和探测效率成正比,与电子学噪声成反比,合理选择辐射源的活度对减小偶然符合计数是重要的,加符合门和单光子鉴别器为提高测量精度和探测效率提供了一种有效途径。     

Nuclear power plant commissioning experience

In this paper, we present the results of the analysis of the events related to the commissioning of new nuclear power plants and reported to the IAEA International Reporting System database. These results are extracted from a study performed by the European Clearinghouse on Nuclear Power Plant Operational Feedback about the events related to the construction, the manufacturing and the commissioning of new nuclear power plants.After the initial screening of the database, we have analysed in detail 34 events in order to highlight the lessons learned specific to different components and to raise the general recommendations related to the commissioning.This paper summarizes the main lessons learned and the main recommendations concerning the commissioning-related events. These recommendations concern mainly the time of the testing, the scope of the tests, the documentation of the tests, the test acceptance criteria, the systems reconfiguration after commissioning tests and the management of the temporary devices.     

Application of Neural Network to Multi-Dimensional Design Window Search in Reactor Core Design

In the reactor core design, many parametric survey calculations should be carried out to decide an optimal set of basic design parameter values. They consume a large amount of computation time and labor in the conventional way. To support directly design work, we investigate a procedure to search efficiently a design window, which is denned as feasible design parameter ranges satisfying design criteria and requirements, in a multi-dimensional space composed of several basic design parameters. The present method is applied to the neutronics and thermal hydraulics fields. The principle of the present method is to construct the multilayer neural network to simulate quickly a response of an analysis code through a training process, and to reduce computation time using the neural network without parametric study using analysis codes. To verify the applicability of the present method to the neutronics and the thermal hydraulics design, we have applied it to high conversion water reactors and examined effects of the structure of the neural network and the number of teaching patterns on the accuracy of the design window estimated by the neural network. From the results of the applications, a guideline to apply the present method is proposed and the present method can predict an appropriate design window in a reasonable computation time by following the guideline.     

基于无量纲准则数的整体效应试验数据适用性验证方法探究

在进行核反应堆与核动力装置安全性评估的过程中,一般需要基于相似比例法则建立整体效应试验（IET）或分离效应实验（SET）台架,为安全性能验证与评估提供数据支撑。作为衡量比例相似程度的重要参数,无量纲准则数可以对特定物理现象做出独立于台架特性、装置尺寸等的表征,因此可以用于比例设计的合理性验证以及实验数据的适用性评估。对无量纲数的跨台架应用可以避免过量重复性实验,也可辅助评估单一台架未能准确复现的某个物理现象。为了探索无量纲数在比例分析和实验数据适用性评估中的应用方法和原则,本文针对传统压水堆的小破口失水事故（SBLOCA）,基于RELAP5数值模拟结果,使用自上而下的比例分析方法对整体效应试验台架LOFT和LOBI进行无量纲参数计算和数据对比。分析结果表明,与破口质量流出、堆芯衰变热、一回路压力等重要现象和参数相关的无量纲数跨台架吻合较好;而与回路摩擦阻力、回路浮升力等相关的无量纲数比率有较大失真。本文采用的无量纲分析方法预期可用于同类型试验台架的实验数据互验,并为新堆型的开发和验证提供参考。      

广州地区室内氡、(气土)浓度随季节及昼夜变化规律的探讨

本文报道1984年7月至1985年6月间在本院实验室内测定的氡、(气土)浓度随季节和昼夜变化的情况。结果表明氡浓度的昼夜变化为早晨6—7时较高,下午1—3时较低,最高与最低值之比达3—4倍,接近日平均水平的时间为上午8—11时;氡、(气土)浓度随季节的变化规律相似,都是冬季(1—3月)较高,夏季(6—9月)较低,氡、(气土)月平均浓度的最高和最低值之比,分别为7.0和5.0倍,春(4—5月)、秋季(10—12月)的氡,(气土)浓度都分别与其年平均水平接近。     

CO2 Reforming of CH4 by Atmospheric Pressure Abnormal Glow Plasma

A novel plasma atmospheric pressure abnormal glow discharge was used to investigate synthesis gas production from reforming methane and carbon dioxide. Special attentions were paid to the discharge characteristics and CH4, CO2 conversion, H2, CO selectivity, and ratio of H2/CO varied with the changing of discharging power, the total flux, and the ratio of CH4/CO2. Experiments were performed in wider operation variables, the discharging power of 240 to 600 W, the CH4/CO2 of 0.2 to 1.0 and the total flux of 140 to 500mL/min. The experiments showed that the conversion of CH4 and CO2 was up to 91.9% and 83.2%, the selectivity of CO and H2 was also up to 80% and 90% and H2/CO mole ratio was 0.2 to 1.2, respectively. A brief analysis for discharge characteristics and the experimental results were given.     

Experimental Investigation of the Steam Condensation Phenomena due to a Multi-hole Sparger

KAERI has performed a series of steam condensation tests to assess the performance of a unit cell sparger that will be used in the APR1400 reactor. A simplified I-sparger was used for the steady state steam condensation tests to study the characteristics of the condensation phenomena due to a multi-hole sparger and to provide test data for a code development and verification. A range of steam mass fluxes for the steady state condensation tests were selected to define the transition region from the condensation oscillation regime to the stable condensation regime. Condensation loads and a variation of the frequencies of the pressure waves due to a steam condensation are analyzed. In addition, the local temperature distribution near the sparger discharge holes is discussed and a condensation regime map for a multi-hole sparger has been suggested.     

An Evaluation of Safeguards Approaches for Neptunium

The International Atomic Energy Agency has recently drawn attention to the fact that neptunium (Np), a byproduct of the nuclear power industry, can be used to make nuclear weapons. Current monitoring approaches for Np do not rely on material balance accounting as is used for uranium and plutonium. In the future this may change. Although full material balance accounting is not anticipated for Np, it is informative to evaluate the impact and benefit of full material balance accounting when considering other options. Therefore, this paper will apply systems analysis to evaluate ways to convert the current system to full materials balance accounting that will minimize the intrusiveness of the verification system and minimize costs to both the facility operator and the inspection agency. We then compare full material balance accounting to partial material balance accounting and to a ratio-monitoring technique referred to as flow sheet verification. We conclude that sampling approximately 25% of the batches is likely to be adequate and that Pu (or perhaps ¹³⁷Cs) will be the most effective surrogate for estimating the Np in the input accountability tank.     

New developments at JET in diagnostics, real-time control, data acquisition and information retrieval with potential application to ITER

In magnetic confinement fusion, the operation of next generation devices will be significantly different compared to present day machines. The duration length of the discharges will require abandoning the traditional paradigm of processing and storing the data after the shot. In fact most information will have to be made available in real-time. The significant issues of machine protection will require more sophisticated and at the same time more robust feedback control schemes. Another very important issue emerged in the last years of JET operation, and which is expected to become more severe in ITER, is the large amount of data to be analysed, which cannot be handled in the most efficient way with traditional methods.In order to prepare for the operation of ITER, some tests are being performed at JET. The capacity of the real-time network has increased in the last years, and many more systems, mainly diagnostics have been connected to it in order to test their reliability and to assess the quality of the information they can provide for feedback control. To reduce the amount of data, a prototype of real-time adaptive data acquisition techniques is being implemented, to adjust the acquisition frequency to the time resolution of the phenomena to be analysed in the plasma. Lossless data compression techniques have been refined and various intelligent signal processing methods have already been implemented to allow an easier and more objective first screening of the data. To allow scientists from wide and diffuse communities to participate in the scientific and technical programme, various innovative tools for remote participation and experimentation are also being actively investigated.