一种基于RPC的空间μ子探测系统

本文介绍了一种利用ＲＰＣ构成的空间μ子探测系统，描述了ＲＰＣ的工作原理和空间μ子探测系统的结构及其设计。     

成象板面探测器系统

成像板是一种新型的集成式面探测器系统，近年来被广泛用于X光，特别是高强的同步辐射X光实验。为改善BSRF的探测条件和水平，最近BSRF购进了一套日本FujiFilm公司生产的BAS－2500成象板探测系统，提出供给广大用户使用。本介绍了IP的工作原理、特性及应用，并对BSRF的IP探测系统作一简要介绍。     

中国实验快堆燃料破损探测系统建模、计算与分析

在借鉴国外研究成果的同时,结合中国实验快堆(CEFR)燃料破损探测系统的设计特点,建立了CEFR燃料破损探测系统的计算模型,并根据所建计算模型,利用LabWindows/CVI开发了CEFR燃料破损探测系统计算分析程序。用该程序进行了缓发中子探测系统可探测最小破损面积的计算,并对裂变产物的释放产生比进行了计算验证。     

反冲靶中子探测系统DT灵敏度的实验研究

设计了实验标定用PIN-反冲质子靶室探测系统,利用加速器中子源对探测系统的DT中子灵敏度进行了实验研究,并与理论计算结果进行了比较,一致性较好.实验结果检验和验证了理论计算程序,可以为同种类型探测系统的参数设计提供实验依据.     

一台用于重核素测量的能量-飞行时间探测系统

研制了一台用于重核素测量的能量-飞行时间探测系统.探测系统由飞行时间探测器和金硅面垒型能量探测器组成,金硅面垒型探测器兼做飞行时间探测器的停止探测器.用该探测系统在中国原子能科学研究院串列加速器质谱装置上对182Hf9+离子的能量-飞行时间双维谱进行了测量.该探测系统对77.4 MeV182Hf9+离子的能量分辨率为3.8％,飞行时间分辨为0.8ns.     

多放射源3D搜寻定位系统设计与模拟

为实现对多个放射源的搜寻定位,设计了用于确定放射源坐标的探测系统。探测系统基于方位角测量,用Na I探测器辨别γ放射源的方向。利用MCNP软件进行多放射源搜寻定位模拟实验,结果表明探测系统能够在多个放射源形成的辐射场中实现对放射源的搜寻并确定其空间坐标,且坐标偏差较小。探测系统可用于搜寻丢失的γ放射源并尽快确定其空间坐标。     

分布式感温光纤探测系统在AP1000核电厂中的应用

AP1000核电厂首次将分布式感温光纤探测系统应用于1E级与非1E级电缆桥架火灾探测。文章介绍了分布式感温光纤探测系统技术原理,分析了感温光纤探测系统的结构及其特点,并根据核电厂的特殊环境,研究了对感温光纤的影响以及提出了相关建议,最后介绍了AP1000分布式感温光纤探测系统设计、光纤布置方案。     

三探头组合放射源定位探测系统模拟设计

采用MCNP法设计了一种由3个探测器组合而成的探测系统。并在3个探测器中间设计了不同形状的屏蔽层,研究不同屏蔽层形状下探测系统的探测灵敏度。理论计算和MCNP模拟结果对比表明:在相同距离下,C型探测系统的灵敏度优于A型和B型;A、B、C型三种探测系统的灵敏度都随距离的增大而降低,但C型探测系统始终优于A型和B型;针对文中建模的探测器尺寸,该结构适用于半径为5 m范围以内的放射源定位工作,通过比较模拟结果C型结构更适合作为便携式放射源准确定位仪器的探测器。     

剩余气体束流剖面探测系统的初步研制

介绍了剩余气体柬流剖面探测系统的工作原理和设计依据，描述了所设计的系统结构并进行了初步实验，证明了利用剩余气体探测柬流剖面的方法是可行的。     

狭缝式脉冲裂变中子靶室对γ的抑制能力

本文采用MCNP程序计算了狭缝式裂变中子探测系统的伽玛灵敏度。并根据探测系统对14MeV中子灵敏度的实测值,得到了系统n／γ分辨参数。满足了n／γ分辨能力大于5的设计要求。     

核电站实物保护系统的量化评估

在及时探测分析方法的基础上,运用形态学分析方法建立了核电站入侵路径分析模型,开发了用于实物保护系统路径型模型分析评估软件.以麦克阿瑟核能中心假想的入侵事件为例,对实物保护系统的探测、延迟、响应进行定量分析.结果表明,路径性及时探测分析方法可有效找到核电站实物保护系统的薄弱环节,辅助得出系统费-效比相对较高的改进措施,有效评估系统的整体性能.     

核电建安工程辐射安全风险分析及管理实践

建立了核电工程施工领域射线探伤辐射安全故障树模型,采用故障树分析方法全面分析了射线探伤作业过程中发生辐射安全事件的风险。结合我国辐射防护相关法律、法规和标准的具体要求,参考Bechtel和FA3等公司的做法,按照作业工艺流程,制定了一套完整的核电施工现场射线探伤控制措施,从管理制度上和技术手段上杜绝安全事件的发生,规范核电工程施工领域射线探伤的辐射安全防护管理。     

Quench detection of fast plasma events for the JT-60SA central solenoid

The JT-60 is planned to be modified to a full-superconducting tokamak referred to as the JT-60 Super Advanced (JT-60SA). The maximum temperature of the magnet during its quench might reach the temperature of higher than several hundreds Kelvin that will damage the superconducting magnet itself. The high precision quench detection system, therefore, is one of the key technologies in the superconducting magnet protection system.The pick-up coil method, which is using voltage taps to detect the normal voltage, is used for the quench detection of the JT-60SA superconducting magnet system. The disk-shaped pick-up coils are inserted in the central solenoid (CS) module to compensate the inductive voltage. In the previous study, the quench detection system requires a large number of pick-up coils. The reliability of quench detection system would be higher by simplifying the detection system such as reducing the number of pick-up coils. Simplifying the quench detection system is also important to reduce the total cost of the protection system. Hence the design method is improved by increasing optimizing parameters. The improved design method can reduce the number of pick-up coils without reducing the sensitivity of detection; consequently the protection system can be designed with higher reliability and lower cost. The applicability of the disk-shaped pick-up coil for quench detection system is evaluated by the two dimensional analysis. In the previous study, however, the analysis model only took into account the CS, EF (equilibrium field) coils and plasma. Therefore, applicability of the disk-shaped pick-up coil for the quench detection system remains open question because the fast plasma events, such as disruption, mini collapse and ELM (edge localized mode), directly influences on the voltage of pick-up coil making the quench signal undetectable. Consequently, a new analysis model proposed in the present paper was designed to avoid this difficulty by introducing the passive coil series such as vacuum vessel and stabilizer. The influence of fast plasma events is absorbed by passive coil series like real system, and the evaluation of applicability can be examined in detail. The analysis results show that the disk-shaped pick-up coil is applicable whenever the standard operation, disruption, mini collapse and ELM.     

光中子爆炸物成像的一种还原方法

针对光中子成像中的模糊图像还原问题,研究了模糊来源,建立了一种物理数学模型。在此基础上,分别使用非约束条件下以及约束条件下的迭代算法,对数学模型进行求解。模拟及实验数据反解结果表明,约束条件下的反解算法能有效地消除成像中的模糊重叠现象,有利于更加清晰准确地判断被探测物的性质。     

Recent progress in JAERI single ion hit system

Single ion hit system has been installed in heavy ion microbeam system in JAERI Takasaki for analysis of single event phenomenon in semiconductor devices. The detection and control of a single ion injection to a target have been achieved by combining a beam pulsing system with a gated detection system. The microscopic observation of a track detector hit by a single ion periodically, shows the controls of the hit positions and numbers of incident ions are successful.     

Adaptive fuzzy inference causal graph approach to fault detection and isolation of field devices in nuclear power plants

An adaptive fuzzy inference causal graph is presented as an integrated approach for fault detection and isolation of field devices including sensors, actuators, and controllers in nuclear power plants. In this approach, nuclear plant systems are represented as a causal graph consisting of individual process variables connected with adaptive fuzzy inference system models. The adaptive fuzzy inference system models generated from historical data are used to characterize the relationships among process variables during normal operation. Fault detection and isolation is achieved by monitoring and cause-effect reasoning on the residuals. This unique cause-effect reasoning strategy for fault isolation can avoid seeking signatures patterns from fault data, which are usually very difficult to obtain for a large system. The most parsimonious model structure, which is a decisive factor in building robust data driven models, is achieved through the system decomposition that inherent in a causal graph. The developed approach has been demonstrated for a simulated pressurized water reactor steam generator system. Both simple faults and complex faults with fault propagation can be successfully isolated during their incipient fault stages, regardless of fault magnitudes and initial power level.     

Design of a single ion hit facility

The aim of this project is to develop a new system for single ion irradiation of cells for genetic and cell biology studies. This charged particle focused microbeam system will provide a fully computer controlled irradiation facility with submicron (subcellular) resolution and will open many new avenues into studies of radiobiological mechanisms. In the first stage of this project a system for single ion detection has been developed. A thin diamond window has been tested as vacuum/atmosphere window and as a possible source of secondary electrons and/or photons for single ion detection. A detection efficiency of 97% has been achieved.     

Development of probability of detection functions for evaluating integrity of axial outside diameter stress corrosion cracks in steam generator

The reliability of an eddy current testing (ECT) inspection system depends upon the inspection technique and quality of analyst. In evaluating the integrity of a steam generator (SG) tube, degradation detection and sizing accuracy are considered performance measures of the nondestructive evaluation (NDE) system. A probability of detection (POD) model serves as a functional measure of the ability of an NDE system to detect degradation. It is one of the inputs in the operational assessment, and it is used to estimate the degradation during service via ECT of the SG tube. In this study, the POD functions of the inspection technique and analyst were obtained to quantitatively analyze the ECT bobbin probe for axial outside diameter stress corrosion cracks in SG tubes. This should serve to evaluate the integrity of the SG tubes. The depth and amplitude of defects were used as parameters of the POD model. Hit (detection) and miss (no detection) binary data obtained from destructive and nondestructive inspection of cracked tubes were also used.     

Study of electromagnetic noise influence on quench detection system under different discharge conditions for EAST

EAST is the first Tokamak device whose toroidal and poloidal magnet are superconducting. The enormous magnetic field energy stored in the magnet system will transfer into thermal energy and cause the damage of superconducting magnet, if a quench happened. Therefore, reliable quench detection is a key issue for steady-state operation. In addition to electromagnetic noise from poloidal magnet fields and plasma current which will experience fast current ramp rate, radio frequency noise from heating system also have some interference on quench detection system to a certain degree. The most difficult point for quench detection system is required to have more detail evaluation on electromagnetic noise interference.Recently experiments have been carried out successfully in EAST device. The steady-state operation with 1 MA of plasma current and more than 100-s plasma duration has been obtained. In the paper, the electromagnetic noise interference on quench detection system under different discharge conditions are analyzed and relative process methods are also introduced. The technological experience and experimental data are significant for the constructing ITER and similar superconducting device have been mentioned which will supply significant technological experience and experimental data for constructing ITER and similar superconducting device.