HT-7托卡马克等离子体逃逸电子螺旋角散射研究

在托卡马克等离子体中,相同的等离子体电流条件下,若在较低的等离子体密度条件下发生反常多普勒共振,将会导致逃逸电子快螺旋角散射（FPAS）的发生;若在较高的等离子体密度条件下发生反常多普勒共振,则会导致逃逸电子正常螺旋角散射（NPAS）的发生。通过研究FPAS和NPAS条件下的逃逸电子行为,发现FPAS和NPAS均可一定程度增加逃逸电子的螺旋角,增加逃逸电子的同步辐射损失,减小逃逸电子的能量;且NPAS和FPAS对逃逸电子的影响主要集中在高能部分,对低能逃逸电子的影响较小。     

托卡马克实验装置的实验大厅移动辐射监测机器人设计

托卡马克实验装置(experimental advanced superconducting tokamak, EAST)在进行聚变等离子体放电实验时,随着中性束注入、低杂波电流驱动、电子回旋波共振加热等大功率辅助加热系统投入运行,等离子体中子出射强度可达10¹⁴ n/s,这导致大厅及窗口区域的中子光子剂量率明显增加。为了保证工作人员及维护人员的安全,需要及时了解不同位置处的辐射剂量。本研究基于六轮移动救援机器人底盘,研制EAST实验大厅移动辐射监测机器人,并搭载X、γ辐射在线监测仪,通过同步定位与建图技术（SLAM）构建环境地图自主移动或通过高清图像远程控制及数据传输系统,将大厅内不同位置的辐射剂量值传递给上位机。通过巡测路径上的剂量率异常,可向周围的工作人员及时发出警示,以此确保实验人员的辐射安全和判断现场维护人员的滞留时间。     

先进超导托卡马克实验装置等离子体密度远程控制系统

在先进超导托卡马克实验装置实验阶段,与密度控制有关的实验数据和信息存储在实验现场的计算机系统中,对这些数据进行分析研究时需要到现场才能采集或获取.设计了托管控件,用于等离子体密度远程控制系统业务逻辑的封装,实现了增强型的B/S计算结构,解决了远程控制过程中复杂的科学计算,并实现了实验进程的同步监视.还在数据交换机制中部署了web services和Data File services两层服务,有效地维护了数据传数链路的松散耦合特性.实验证明,它不仅实现了密度的远程控制功能;而且在目前的托卡马克实验情况下,具有较好的数据传输性能.     

宇宙线μ子角分布探测装置构建

为测量近地面宇宙线μ子的天顶角分布,构建了一套由两个相互平行放置的长塑料闪烁体探测器组成的探测装置,研究了影响装置性能的主要因素,优化了装置的结构设计参数。利用优化后的装置,测量得到了μ子的天顶角分布符合cos2θ的规律。观察到了角分布的东西向不对称性,当天顶角为30°时,东西向的差异约为3.5(1.5)%。     

The Positions and Number of Flux Loops and Magnetic Probes for the HT—7U Superconducting Tokamak

The plasma shape and other paremeters such as βp,li is important for the tokamak deveice where the palsma has a non-circular cross-section of sufficient elongation.The measuered signals of magnetic probes and flux loops are used to reconstruct the plasma shape and the current profile in device operation and plasma shape feed back control system.So the number and positions of magnetic probes and flux loops provides the basis of the plasma reconstruction.This paper instroduce how to use EFIT code (equilibrium fitting code)to determine the number and positions of the magnetic probes and flux loops.The simulation result is given also.     

Study of the DEF Feedback Control System in AC Operation of Superconducting Tokamak

AC operation with multiple full cycles has been successfully performed on the superconducting tokamak HT-7. In the experiment, it was discovered that the saturation of the transformer magnetic flux with DEF, a signal name, was one of key aspects that affected the AC operation. The conditions of DEF were examined through the DEF feedback control system. By controlling the working patterns of the subsystems, namely the poloidal field control system and density control system, it was guaranteed that DEF would remain in the non-saturated status.     

强X光辐射场加门光电倍增管实验研究

我们在神光装置打靶现场对加门光电倍增管进行了调试和研究。实验结果表明，光电倍增管的恢复时间是随基饱和深度的增加而增加的。ＸＰ２０４０光电倍增管配上２μｓ的高压脉冲开关可用于偿烁探测器在神光装置辐射驱动聚变靶时进行强Ｘ射线辐射场的低产额中子测量。     

先进压水堆非能动余热排出技术试验研究

总结了中国核动力研究设计院空泡物理和自然循环国家级重点实验室10年来开展的先进压水反应堆非能动余热排出技术试验研究和专用程序开发研究，提出了下一步开展相关工程研究的建议。     

The Compression Algorithm for the Data Acquisition System in HT－7 Tokamak

HT-7 superconducting tokamak in the Institute of Plasma Physics of the Chinese Academy of Sciences is an experimental device for fusion research in China. The main task of the data acquisition system of HT-? is to acquire, store, analyze and index the data. The volume of the data is nearly up to hundreds of million bytes. Besides the hardware and software support, agreat capacity of data storage, process and transfer is a more important problem. To deal with this problem, the key technology is data compression algorithm. In the paper, the data format in HT-7 is introduced first, then the data compression algorithm, LZO, being a kind of portable lossless data compression algorithm with ANSI C, is analyzed. This compression algorithm, which fits well with the data acquisition and distribution in the nuclear fusion experiment, offers a pretty fast compression and extremely fast decompression. At last the performance evaluation of LZO application in HT-7 is given.     

Preliminary Analysis of Advanced Equilibrium Configuration for the Fusion-Driven Subcritical System

The Fusion-Driven Subcritical System (FDS) is a subcritical nuclear energy system drived by fusion neutron source. In this paper, an advanced plasma configuration for FDS system has been proposed, which aims at high beta, high bootstrap current and good confinement. A fixed-boundary equilibrium code has been used to obtain ideal equilibrium configuration. In order to determine the feasibility of FDS operation, a two-dimensional time-dependent free boundary simulation code has been adopted to simulate time-scale evolution of plasma current profile and boundary position. By analyses, the Reversed Shear mode as the most attractive one has been recommended for the FDS equilibrium configuration design.     

Experimental Verification of Modified DYNAM Code for Flow Stability Analysis in Once-Through Boiling Flow System

A rainout-washout model is proposed in order to forecast the variation of the intensity of environmental γ-rays and study the behavior of radioactive nuclei in the atmosphere on rainy days. This model divides the atmosphere into two parts of in cloud and under cloud. Simultaneous differential equations are formulated to give the time variations of the concentrations of daughter nuclei of ²²²Rn during precipitation in each state of free atoms or ions, aerosol particles, cloud droplets and rain drops. Coefficients used in the equations for removal of daughter nuclei from one state to other one and for washout by rain drops are estimated from published data. Variations of various concentrations are obtained. Counting rates of a ge(Li) detector are calculated for 352 kev (²¹⁴Pb) and 609 kev (²¹⁴Bi) γ-rays. They are mainly due to γ-rays from daughter nuclei accumulated on the earth's surface, most part of which is brought by rainout in cloud. Experimental variations of counting rates are well reproduced on rainy days. For the forecast of the variations it is necessary to measure rainfall rates, concentrations of ²²²rn and cloud base heights at short interval.     

辐射成像中射线源低频震动对图像影响的研究

对一种大型辐射成像系统－TCM－SCAN系统成像过程中射线源震动的影响进行建模,从理论上对这种影响进行分析,得出射线源震动给图像带来的噪声是乘法性,并确定了噪声频谱特性。同时设计了验证噪声特性的实验,理论与实验符合。在此基础上设计了消除这种噪声的方法。     

核动力反应堆零功率物理试验的多普勒发热点测量试验

为了定量确定零功率物理试验功率的上限,在反应堆零功率物理试验中,利用数字反应性仪测量多普勒发热点,以确定试验功率的范围、保证试验精度。叙述了本次多普勒发热点测量试验的原理、试验仪器、试验方法、试验结果及数据处理方法等,试验结果表明:利用数字反应性仪测得的反应性经过修正后可以准确地判断多普勒发热点,可为后续物理试验提供参考。     

加速器驱动次临界系统的中高能质子轰击厚靶中子学实验研究

利用俄罗斯杜布纳联合核子研究所的高能加速器进行加速器驱动次临界系统 (ADS)靶区中子学研究。用 0 .5 33、1 .0、3.7和 7 4GeV质子轰击U(Pb)、Pb和Hg靶的测量结果表明 :U(Pb)和Pb与Hg靶的中子产额比分别为 ( 2 0 1± 0 1 0 )和 ( 1 76± 0 33) ,从获得较强中子的角度看 ,Hg作为ADS靶是不利的 ;沿厚 2 0cm靶的中子产额随入射质子穿透深度增大而下降 ,质子能量越低 ,中子产额下降越快 ,为在较大厚度范围内获得较均匀的中子场 ,质子能量不应低于 1GeV ;不同能量质子产生的次级中子能谱相近 ,但随质子能量提高 ,较高能量中子的比例逐渐增大。     

5MW核供热站余热排出系统的试验研究

清华大学5MW核供热站的余热排出系统是由3个自然循环构成的非能动式余热排出系统。各个阶段的调试表明,该系统的设计是合理的,3个循环均能迅速建立,排热能力达到设计要求。对于主换热器与蒸发器间循环建立条件,循环流动方向,蒸发器与空冷器间蒸发-冷却循环的建立条件等都进行了试验研究,并给出了明确结论。     

一种乏燃料后处理系统安全工程能力成熟度评估系统

SSE-CMM可用于过程改进、能力评估和提高用户的信任度,是组织和实施安全工程的通用方法,是系统安全工程领域成熟的方法体系。SSE-CMM结合了计算机科学中的CMM模型、管理学中的全面质量管理思想和统计理论,将系统安全工程转换为一个具有良好定义的、成熟的、可测量的先进工程学科。SSE-CMM评估面临领域知识缺乏、数据量大、证据类型多样、过程繁琐、证据与问题匹配复杂等问题。为有效提高评估效率,本文依据本体论、证据理论、语义网、智能信息检索、智能自动匹配等技术和方法,针对乏燃料后处理系统,设计了一种基于领域本体的智能评估软件系统,主要包括领域本体建模和管理、证据自动收集、问题和证据自动匹配、过程评估等4个子系统,技术体系结构分为数据层、本体层、知识层、服务层、表示层5层。     

Feedback Control System for Antenna Phase Difference in the LHCD Experiments

It is well accepted that lower hybrid current drive （LHCD） is the most efficient method for non-inductive current drive in fusion devices and the effect of the current drive is dependent on not only microwave power but also its grill phase shift. This paper presents a new kind of feedback control system for antenna phase difference in LHCD experiments. In this highspeed control system, a lot of new technologies and methods are incorporated. The results of the experiments show a very good agreement with the system design.     

核电站保护系统多样化手动驱动系统设计

针对基于计算机技术的数字化仪控系统可能存在软件共因故障问题,设计了一个安全系统系统级手动驱动系统。该系统用以在计算机技术实现的保护系统失效后执行安全功能。本文介绍了与该系统相关的安全系统的系统级操作、事件级的电站状态监视、定期试验、非计算机化设备、独立性、多样化等内容。这些特点能够保证在采用计算机技术的反应堆保护系统失效后,提供有效的安全功能执行手段,缓解事故后果。该系统弥补了计算机化仪控系统的弱点,能够防止软件共因故障。     

Development of a Small-Aperture Slit System for a High Collimator Ratio at the Thermal Neutron Radiography Facility in JRR-3

A small-aperture slit system has been developed and installed to enhance the collimator ratio (“L/D”) of the thermal neutron radiography facility (TNRF) in JRR-3. The degree of unsharpness on neutron images is reduced by increasing the L/D. The small-aperture slit system increased the L/D by creating a small aperture size (“D”). Image sharpness improved when the aperture size was reduced to below 10mm by 10mm in the TNRF. On the other hand, there was almost no difference in unsharpness on images obtained above 10mm by 10mm in aperture size. These results indicate that an aperture size of less than 10mm by 10mm should be used for high-spatial-resolution imaging at the TNRF. The beam area of the small-aperture slits was relatively small in comparison with that of a conventional large collimator, though gradually increasing with increasing aperture size. Even with an aperture size of 5mm by 5 mm, the practical beam area for imaging examinations corresponded to around 25mm by 20 mm, which is enough area to carry out high-spatial-resolution imaging.