核部件非授权移动安全警戒系统方案设计

介绍了一个核部件非授权移动安全警戒系统的设计方案,讨论了核部件的移动快速检测技术和对位监测方法,提出了系统的结构组.     

高能物理网格门户的设计与实现

网格门户是网格技术的一个重要组成部分.文章对高能物理网格门户的设计、功能及其实现作了阐述,该网格门户采用面向服务的思想,通过门户中的基本单元Portlet来访问LCG网格中间件所提供的网格服务,从而为高能物理学家使用高能物理网格所提供的各种资源提供了一个安全方便的统一接口.     

核电厂辐射控制区分机组授权研究与开发

通过对辐射控制区进出监测系统的控制逻辑进行深入研究,探索核电厂放射工作人员统一授权与工作分机组授权相结合、将放射性活动明确限定至对应机组的方法,重点就解决辐射控制区分机组授权的方法和应用进行阐述,为辐射控制区进出监测系统化做出尝试。     

用于计算较大尺度面源气载放射性释放的环境辐射剂量的一种套网格模型

本文介绍一种用于较大尺度面源气载放射性释放环境影响评价的套网格模型，该模型采用扇形网格和正方形网格相结合，以扇形网格为基本框架，而将面源区和近源区划分为正方形网格，在进行大气扩散估算时，为合理模拟空气浓度分布，在面源区和近源区，采用大气湍流扩散实验室模式；在其它区域，将面源视作若干个虚拟点源，采用高斯烟羽模式。在进行环境辐射剂量估算时，先将正方形网格点的空气浓度值内插到扇形网格，然后按扇形网格下的     

高能物理与网格计算

概略介绍了高能物理实验计算环境的最新发展情况．包括近一些年来国际高能物理实验发展和对计算需求的增长变化;以正在建造中的LHC上的实验为例介绍了为满足这些需求而制订的计算环境规划;网格计算技术诞生的历史及国际高能物理网格技术研究的现状;高能物理网格所需要的网络基础设施的发展情况等。最后介绍了正在起步中的我国高能物理网格技术研究。     

钠冷快堆直流式蒸汽发生器固定网格与滑移网格模型对比分析

根据钠冷快堆核电厂直流式蒸汽发生器(OTSG)的热工水力特性,基于固定网格模型和滑移网格模型编制了OTSG瞬态分析程序OTAC。对美国能源技术工程中心(ETEC)的OTSG停闭实验进行了模拟,并将计算值与实验值作了对比分析。结果发现,两种模型的计算值与实验值吻合较好,其中固定网格模型只有在网格数目足够多时才能避免计算结果的突跳,而滑移网格模型可在较少网格数目下取得很好的计算效果,提高了数值稳定性,避免了计算结果的不连续。     

网格计算环境的信息和监视系统实现研究

整合全球范围多单位的资源,如计算资源、存储资源、网络资源,以及不同地域具有各种专长的人力资源和昂贵的智能设备。网格就是针对当今科学研究的这些特点提供支持的计算技术,因而将会成为未来科学的一种基础设施。作为一种全球范围内的计算技术,需要解决许多关键的技术。将介绍网格的体系结构、安全基础设施,以及设计的网格信息管理与监视系统等。     

电子商务安全保密技术

电子商务是利用计算机网络的信息交换来实现电子交易，大量的经济信息在网上传递，资金在网上划拨流动，因此，网上信息的可靠性和保密性，都必须确保万无一失，足够高的信息安全性是成功发展电子商务的一个关键性因素，本文主要介绍针对网络安全问题所涉及到的几种技术：虚拟专用网技术，信息加密技术，信息认证技术，防火墙技术和计算机应用技术。     

蒙特卡罗粒子输运计算网格计数方法研究

在进行反应堆数值模拟时,通过网格计数方法可以精细地统计整个堆芯中多种物理量的空间分布情况。本文基于超级蒙特卡罗核计算仿真软件系统SuperMC发展了一种反应堆静态物理参数的网格计数方法。通过日本原子能研究所临界实验装置TCA例题进行了数值验证,计算结果与MCNP计算结果吻合较好,表明了本文方法的可行性与正确性。     

基于神经网络的CFD粗网格模拟优化方法研究

为缓解使用计算流体力学(Computational Fluid Dynamics,CFD)程序进行反应堆热工水力数值模拟中计算效率和计算精度之间的突出矛盾,以实现在较高计算效率下得到较高精度的计算结果,研究借助机器学习(Machine Learning,ML)中的前馈神经网络(Feedforward Neural Ne...     

Numerical study of the grid erosion of field emission electric propulsion

In this paper,the immersed finite element particle-in-cell Monte Carlo collision (IFE-PIC-MCC)model is used to study the cause of the grid erosion in field emission electric propulsion (FEEP).The simulation results show that charge exchange (CEX) ions are the main cause of the grid erosion,while beam ions basically do not impinge on the grid.The CEX ions are mainly generated near the grid.Some of these CEX ions return to the upper surface,lower surface and notch side surface of the grid.The impact angle of CEX ions returning to the upper and side surfaces is large,but their energy is low,while the impact angle of CEX ions returning to the lower surface is small,but their energy is high.The above characteristics lead to the similar erosion rates of these three surfaces.     

Simulation of the anode structure for capacitive Frisch grid CdZnTe detectors

CdZnTe (CZT) capacitive Frisch grid detectors can achieve a higher detecting resolution.The anode structure might have an important role in improving the weighting potential distribution of the detectors.In this paper,four anode structures of capacitive Frisch grid structures have been analyzed with FE simulation,based on a 3-dimensional weighting potential analysis.The weighting potential distributions in modified anode devices (Model B,C and D) are optimized compared with a square device (Model A).In model C and D,the abrupt weighting potential can be well modified.However,with increased radius of the circular electrode in Model C the weighting potential platform away from the anode becomes higher and higher and in Model D,the weighting potential does not vary too much.     

A Web-Based System for Remote Data Browsing in HT-7 Tokamak

HT-7 is the first superconducting tokamak device for fusion research in China.Many experiments have been performed on the HT-7 tokamak since 1994 with numerous satisfactory results achieved in the fusion research field. As more and better communication is required with other fusion research laboratories, remote access to experimental data is becoming increasingly important in order to raise the degree of openness of experiments and to expand research results. The web-based remote data browsing system enables authorized users in geographically different locations to view and search for experimental data without having to install any utility software at their terminals. The three-tier software architecture and thin client technology are used to operate the system effectively. This paper describes the structure of the system and the realization of its functions, focusing on three main points： the communication between the participating tiers, the data structure of the system and the visualization of the raw data on web pages.     

300MW燃料组件定位格架导向翼三维流场分析

从三维流场分析角度验证了300MW燃料组件定位格架导向翼初步设计改进方案的合理性,采用流体计算软件对燃料组件定位格架或棒束定位格架进行计算,比较导向翼修改前后的定位格架水力特性和导向翼周围流场的变化,为实际工程应用提供了依据。     

Code validation for the magnetohydrodynamic flow at high Hartmann Number based on unstructured grid

In order to analyze the magnetohydrodynamic (MHD) effect in liquid metal fusion blanket, a parallel and high performance numerical code was developed to study MHD flows at high Hartmann Number based on the unstructured grid. In this code, the induced current and the Lorentz force were calculated with a current density conservative scheme, while the incompressible Navier–Stokes equations with the Lorentz force included as a source term was solved by projection method, a set of method were used to improve the computing performance such as Krylov subspace method and AMG method. To validate this code, three benchmarks of MHD flow at high Hartmann Number were conducted. The first benchmark was the case of Shercliff fully development flow, the second benchmark was the MHD flow in a circular pipe with changing external magnetic field, and the third benchmark was the MHD flow in a pipe with sudden expansion. In these cases the Hartmann Numbers were from 1000 to 6000. The code good computing performance, and numerical results show matched well with the analytical and experimental results.     

Plasma grid design for optimized filter field configuration for the NBI test facility ELISE

Maintenance-free RF sources for negative hydrogen ions with moderate extraction areas (100-200 cm²) have been successfully developed in the last years at IPP Garching in the test facilities BATMAN and MANITU. A facility with larger extraction area (1000 cm²), ELISE, is being designed with a “half-size” ITER-like extraction system, pulsed ion acceleration up to 60 kV for 10 s and plasma generation up to 1 h. Due to the large size of the source, the magnetic filter field (FF) cannot be produced solely by permanent magnets. Therefore, an additional magnetic field produced by current flowing through the plasma grid (PG current) is required. The filter field homogeneity and the interaction with the electron suppression magnetic field have been studied in detail by finite element method (FEM) during the ELISE design phase. Significant improvements regarding the field homogeneity have been introduced compared to the ITER reference design. Also, for the same PG current a 50% higher field in front of the grid has been achieved by optimizing the plasma grid geometry. Hollow spaces have been introduced in the plasma grid for a more homogeneous PG current distribution. The introduction of hollow spaces also allows the insertion of permanent magnets in the plasma grid.     

EAST-NBI抑制极电源IGBT串联技术的研究

中性束注入器(Neutral Beam Injector,NBI)是东方超环(Experimental Advanced Superconducting Tokamak,EAST)核聚变实验装置辅助加热的重要组成部分。目前NBI离子源引出系统采用四电极结构,即加速电极、梯度电极、抑制电极和地电极。抑制极电源是为其中的抑制电极提供负电位的高压直流电源。根据抑制极电源输出特性的要求,输出端采用串联绝缘栅双极型晶体管(Insulated Gate Bipolar Transistor,IGBT)作为调制开关。为研究IGBT串联技术对均压效果和抑制极电源输出特性的影响,采用PSpice软件对IGBT开关进行了建模,并进行了不同电路参数下的仿真。仿真表明:一定条件下,电阻电容二极管(Resistance Capacitance Diode,RCD)缓冲电路中电容参数对动态均压效果和电源关断特性具有决定性影响,缓冲电阻影响电容的放电时间及放电电流峰值。最后给出了相应的实验测试结果。该研究结果可以明确缓冲电路参数与均压效果以及抑制极电源开关特性之间的定量关系,为抑制极电源开关特性的进一步优化及其与加速极电源的特性匹配提供数据指导,对于NBI离子源的安全稳定运行具有重要意义。     

激光诱导荧光技术对棒束通道内定位格架搅浑特性研究

基于激光诱导荧光（LIF）技术开展了5×5棒束通道内定位格架搅浑特性的可视化研究。常温常压下,通过示踪染色剂（RhB）浓度分布表征流体微团的搅浑行为,清晰展现染色剂溶液在定位格架作用下的搅浑扩散过程,获取格架下游流场的搅浑信息。采用自验证方法分析验证LIF技术测量的准确性,重构棒束通道内径向与轴向染色剂浓度分布,对比带定位格架与不带定位格架的实验结果,得到定位格架对其下游流场的影响范围及不同棒束子通道所受搅浑程度的差异,并以变异系数量化格架对流场搅浑性能的强弱。实验结果表明：定位格架能快速搅浑流动工质,其搅浑翼片分布形式的差异是造成不同子通道交叉搅浑强弱及各向异性的主要原因。本实验工况（Re＝10 478）下,格架对其下游流场的作用范围约为8倍当量直径(D_h),流动工质在格架下游5D_h附近所受搅浑最为剧烈。     

Fault diagnosis algorithm for 3-phase passive rectifiers based on frequency-domain analysis for acceleration grid power supply in CFETR NBI system

The acceleration grid power supply (AGPS) is a crucial part of the Negative-ion Neutral Beam Injection system in the China Fusion Engineering Test Reactor, which includes a 3-phase passive (diode) rectifier. To diagnose and localize faults in the rectifier, this paper proposes a frequency-domain analysis-based fault diagnosis algorithm for the rectifier in AGPS. First, time-domain expressions and spectral characteristics of the output voltage of the TPTL-NPC inverter-based power supply are analyzed. Then, frequency-domain analysis-based fault diagnosis and frequency-domain analysis-based sub-fault diagnosis algorithms are proposed to diagnose open circuit (OC) faults of diode(s), which benefit from the analysis of harmonics magnitude and phase-angle of the output voltage. Only a fundamental period is needed to diagnose and localize exact faults, and a strong Variable-duration Fault Detection Method is proposed to identify acceptable ripple from OC faults. Detailed simulations and experimental results demonstrate the effectiveness, quickness, and robustness of the proposed algorithms, and the diagnosis algorithms proposed in this article provide a significant method for the fault diagnosis of other rectifiers and converters.