Study on Scram Time Measurement Method of Control Drum System Experimental Prototype of Space Nuclear Power Device

The control drum system is important safety level device for power regulation and emergency shutdown of the space nuclear power device. The safety of the reactor directly depends on whether the control drum system can operate well or not. In order to test the scram time of the control drum system, a method of judging the zero position and calculating the scram time was proposed by analyzing the rotation and transmission process of the control drum system. The full-scale model of the control drum system experimental prototype and a comprehensive test platform were used to test the scram time. The test results show that the test method is real, effective and reliable, and can be applied to the measurement of scram time in the development and use of control drum system at all stages. At the same time, it is also verified that the design of the control drum system meets the design target that the mechanical scram time is less than 1 s.     

超临界系统裂变增值蒙卡模拟及其时间特性分析

开发蒙卡程序对超临界系统中的中子输运过程进行模拟,计算给出了系统增值系数和中子平均去除时间,与MCNP程序的计算结果符合较好。利用程序的时间驿站功能,计算给出了超临界系统的增值时间常数。分析了特定条件下超临界系统的增值时间常数和增值系数的关系。结果表明,对于超临界系统,其系统增值时间常数除了和增值系数有关以外,主要还受到平均裂变时间的影响。     

空间核动力装置控制鼓系统试验样机快速复位时间测量方法研究

控制鼓系统是空间核动力装置上执行功率调节、紧急停堆的重要安全级设备,其能否正常运行直接关系到核动力装置的安全性。为测试控制鼓系统的快速复位时间,通过分析控制鼓系统的转动和传动过程,提出了快速复位零点判断、计算复位时间的方法。采用1∶1全尺寸控制鼓系统试验样机和综合测试平台,对快速复位时间进行了实测试验。试验结果表明,该测试方法是真实、有效、可靠的,可应用于控制鼓系统各阶段研发、使用过程中快速复位时间的测量。同时也验证了控制鼓系统的设计满足设计指标,机械快速复位时间小于1 s。     

~(60)Co集装箱检测系统直流模式下图像模糊问题的研究

对 60 Co集装箱检测系统直流工作模式和时间响应特性对系统输出的影响机制进行了理论分析 ,从理论上推导了 60 Co集装箱检测系统的冲击响应 ,并利用理论推导结果对集装箱图像进行了反卷积处理 ,该处理对改善图像质量有明显的效果     

怀柔EAS阵列的方向测定系统

本文介绍了由9路快时间测定通道构成的怀柔EAS阵列方向测定系统的测定原理、设备组成,描述了它的标定和使用方法,讨论了它的时间和方向测定精度。光脉冲模拟测量给出通道的分辨时间不大于1ns,对实际观测事例的统计分析表明,系统对EAS的时间分辨约为3ns。该系统已连续运行约一年,并产生了首批物理结果。     

用飞行时间法鉴别粒子的在线三体谱仪的改进

针对迴旋加速器加速相位的不稳定,研制了频率自动微调系统,并用靶上二体事件单能粒子的时间线谱作监控修复信号,减小了迴旋加速器等系统的不稳定而带来的时间幌动,将迴旋加速器上谱仪鉴别粒子的时间分辨降低到<3ns。     

HTR-10技术规格书在线监督系统

10MW高温气冷堆(HTR-10)技术规格书在线监督系统以HTR-10仪表与控制系统提供的数据为基础,采用智能模拟运行人员行为的方法．实时分析判断反应堆系统和设备的工作状态是否满足技术规格书的要求,同时自动按照规定的频度完成部分定期试验和检查工作．对于不能自动完成的检查项目及时提醒运行人员,弥补了人工执行技术规格书时因工作量大、容易出现漏项的不足。本文介绍了HTR-10技术规格书在线监督系统的模型、组成模块、技术开发特点以及具体应用中的注意事项和方法。     

关联α粒子探测器设计和性能研究

关联粒子成像技术（API）是进行爆炸物检测和有源核查的重要手段,而关联α粒子探测器的空间分辨和时间分辨直接决定成像系统的空间分辨能力。本文依托中国原子能科学研究院核数据重点实验室移动中子发生器,结合具有快时间响应的ZnO：Ga与最新的位置灵敏光电倍增管(PSPMT)H13700,设计可用于API的关联α粒子探测器系统。通过SCDC-TCOG将256路信号简化为4路信号,利用数字化仪对信号进行采集分析。通过离线实验对关联粒子探测器的时间性能和空间分辨性能进行了测试。利用刀口法测得空间分辨好于1 mm,并通过狭缝法和栅条法进行了验证。通过测量²⁵²Cf裂变碎片和瞬发伽马符合测量获得系统时间分辨好于1 ns,达到了应用需求。     

注入器Ⅱ离子源控制系统设计

为实现离子源设备的远程监控、束流强度可调和当设备发生异常时的快速切束控制,采用PLC、串口服务器和自制FPGA控制板卡设计了基于EPICS架构的离子源控制系统。同时,改进了原有PLC和电机系统的EPICS IOC程序。整套系统工作可靠、稳定,完全满足注入器Ⅱ系统的调试运行需求。快速切束时间小于10 μs,完全切束动作在60 s内完成。     

Design and development of a synchronized operation control system for Thomson scattering diagnostic on J-TEXT

A Thomson scattering diagnostic system is under construction at the Joint Texas Experimental Tokamak (J-TEXT).A 1064 nm Nd:YAG laser with 50 Hz repetition rate is used as the laser source.We have used a software for careful and precise control of the laser through serial communication.A time sequence operating system has been developed to synchronize the laser control and data acquisition system with the central control system (CSS).The system operates commands from the CSS of J-TEXT and generates triggers for the laser and data acquisition system in the proper sequence.It also measures an asynchronous time value that is needed for accurate time stamping.All functions are served by a field-programmable gate array development platform that is suitable for high-speed data and signal processing applications.Several embedded peripherals,including Ethernet and USB 2.0,provide communication with the CSS and the server.     

A Novel Vacuum System Control Strategy for High Intensity D–T Fusion Neutron Generator

High intensity D–T fusion neutron generator (HINEG) is a high voltage accelerator-based D–T fusion neutron facility, which provides a significant platform for nuclear technology researches. The steady operation of HINEG vacuum system is enormously significant for its beam quality. In this paper, in order to eliminate the drawbacks and disadvantages caused by the time delay element in vacuum system, a gain adaptive compensation control strategy was proposed for vacuum system. In accordance with vacuum-pumping mechanism, the vacuum dynamic equilibrium equation was transformed from the time domain to the complex frequency domain by means of Laplace transformation, and the system transfer function in vacuum pumping process was derived. The experimental results analyses showed that the overshoot and settling time are eliminated effectively with this gain adaptive compensation control algorithm, which indicated that the system self-regulation and anti-interference performances were greatly improved.     

基于微机打印接口的1024道分析系统的研制

介绍了一种新型的１０２４道多道分析系统。本系统由单片微机系统（ＡＴ８９Ｃ５１＋ＰＳＤ３１１）组成多道缓存,由低功耗模数转换器组成分析器,与微型计算机通过打印并行接口实现数据通讯,并含有死时间校正电路。     

Neutron Density Fluctuations in Point Reactor Systems with Dichotomic Reactivity Noise

The exactly solvable stochastic point reactor model systems are analyzed through the stochastic Liouville equation. Three kinds of model systems are treated: (1) linear system without delayed neutrons, (2) linear system with one-group of delayed neutrons, and (3) nonlinear system with direct power feedback. The exact expressions for the fluctuations of neutron density, such as the moments, autocorrelation function and power spectral density, are derived in the case where the colored reactivity noise is described by the dichotomic, or two state, Markov process with arbitrary correlation time and intensity, and the effects of the finite correlation time and intensity of the noise on the neutron density fluctuations are investigated. The influence of presence of delayed neutrons and the effect of nonlinearity of system on the neutron density fluctuations are also elucidated.

When the reactivity correlation time is very short, the correlation time has almost no effect on the power spectral density, and the relative fluctuation of neutron density in the stationary state is not affected very much by the presence of delayed neutrons and also by the nonlinearity of system. On the other hand, if the reactivity correlation time is very long, the effect of the reactivity noise on the power spectral density appears at very low frequency, and the presence of delayed neutrons has an effect of reducing the neutron density fluctuations.     

Application of frequency domain analysis to transient response of nuclear containment structures

A combination of frequency domain and time domain analyses is proposed to obtain the dynamic responses of nuclear power plant containment structures. A soil-structure model of a boiling water reactor containment subjected to an assumed safety relief valve blowdown load is used as illustration. Linear time-invariant systems are analyzed using input forcing functions with varying frequency contents. Time domain analysis is performed using a synthesized input forcing function. The system characteristic function is generated in the frequency domain through Fourier transforms of the response time history and the synthesized input time history. The frequency response due to any other forcing function is obtained in frequency domain by using the system characteristic function, and the response time history is obtained by inverse Fourier transforms of the frequency response. The results obtained by the proposed method are in close agreement with the conventional time domain dynamic finite element analysis.     

HTR-10第二停堆系统的试验与调试

吸收球停堆装置是10MW高温气冷实验堆的第二停堆系统，控制棒失效时，碳化中子吸收球落入堆芯反层的吸收球孔道内，实现紧急停堆；反应堆再次临界前，利用气体输送装置将吸收球送回位于堆顶的贮球罐内，在实验室和高 温堆上先后进行了7套吸收球装置的热态试验和输送功能试验，试验数据表明，吸收球系统7套装置的落球和回球动作正常，所用的时间在要求的范围内；球位状态指示正常；气体回路流动正常，风机的流量，压升正常，12个阀门的开，闭功能正常。     

用单光电子法测试快光电倍增管的时间分辨特性

本文叙述用单光电子法测试快光电倍增管时间分辨的装置和结果。本装置的电子学系统时间分辨小于25ps/道,系统标定值为13.645ps/道。RCA8575的T_(FWHM)为37—56ps,GDB50的T_(FWHM)为35—70ps。     

逆滤波器法在能谱测量中的应用

由于传统测量能谱的方法是采用单道、多道的方法,其有一定的分辨时间,并且无法克服相近脉冲的叠加效应,提出了采用逆滤波器法测量能谱的方法。该方法将探测器系统看作具有某一传递函数的线性系统,对探测器系统的输出进行采样,构造系统的离散逆系统,使采样信号通过逆系统,即可取得原始入射粒子的能量与入射时间。仿真结果表明,采用该方法不仅能准确测量原始入射射线的能量,并能测出其入射时间,克服了传统单道、多道进行能谱测量的一些缺点。     

分布式加速器控制系统时间同步系统的研究

现代大型加速器控制系统大都采用分布式控制系统,系统使用网络交换各类数据.各种控制动作及数据获取要求各智能控制器的CPU基于时间进行调度,因此时标系统在分布式控制系统中具有极其重要的作用.本文论述了采用软件实现的时间同步系统及其所采用的时间协议和原理以及达到的精度等.     

早稻田大学皮秒脉冲辐解装置

A compact pulse radiolysis apparatus using a BNL-type s-band photocathode RF gun is now under development at Waseda University. The laser pulse is used for excitation of the photocathode and for generation of white light, which is used for analyzing light in the pulse radiolysis.The system design is shown in Fig. 1. For absorption spectroscopy with wide wavelength region, the white-light continuum was used as analyzing light. The white light continuum was generated by focusing the high intense IR laser into the water cell. The available wavelength was 400-950 nm. Typical data obtained is shown in Fig.2 by using the system. We have performed a deconvolution technique to know the time resolution of our system. For this purpose, we have assumed the shapes of the electron pulse and the laser pulse as Gaussian distributions. Furthermore, the difference of velocity in a sample cell between the electron pulse and the laser pulse due to the refractive index of a sample was also taken into consideration and assuming that the hydrated electrons are formed as a step function and the response function is Gaussian.Thus, time resolution of the system was estimated by deconvolution of the experimental data.We have achieved a time resolution of about 26ps by measuring time profile of hydrated electrons in H2O.