基于PC的光学速调管磁间隙控制系统

描述了合肥国家同步辐射实验室(NSRL)储存环自由电子激光(SRFEL)光学速调管(TOK)磁极间隙控制系统的原理和结构，给出了系统硬件结构、软件流程图及其工程实现。该调节系统可以独立或同时调节TOK调制段、色散段、辐射段三部分磁极间隙的大小，精度达到0.01mm；多重安全保护能确保储存环真空室不被破坏。     

基于acslX软件的AP1000稳压器压力控制系统动态仿真

针对AP1000稳压器内部传热传质过程的特点,结合西屋AP1000的相关参数,在上海核工程研究设计院控制系统模型的基础上,对其中稳压器的二区数学模型进行完善和改进,利用acslX软件建立稳压器三区动态数学模型,并严格按照西屋AP1000稳压器的压力控制逻辑,对建立起来的数学模型进行了相应的控制仿真实现。通过比较改进前和改进后模型试验结果与相关设计文件的差异,验证了改进后模型较改进前具有更好的精确性、可扩展性,同时该模型可为今后CAP1400稳压器的仿真工作打下一定基础。     

基于LabVIEW设计的RPC-Gd热中子探测器测试系统

在WinXP系统下,基于LabVIEW开发了RPC-Gd热中子探测器的性能测试系统.结合LabVIEW图形显示能力和仿真仪器面板功能,通过调用外部动态链接库机制,封装CAMAC的I/O接口命令为功能函数子Ⅵ系列,以此将各电子学插件编译为功能模块.根据不同实验的要求可对功能模块进行灵活选择和设置.测试系统具有开放性、可移植性,使用界面友好简易.     

A two-dimensional air streamer discharge modified model based on artificial stability term under non-uniform electric field at low temperature and sub-atmospheric pressure

In this paper, an improved air discharge fluid model under non-uniform electric field is constructed based on the plasma module COMSOL Multiphysics with artificial stability term, and the boundary conditions developed in the previous paper are applied to the calculation of photoionization rate. Based on the modified model, the characteristics of low temperature subatmospheric air discharge under 13 kV direct current voltage are discussed, including needle-plate and needle-needle electrode structures. Firstly, in order to verify the reliability of the model, a numerical example and an experimental verification were carried out for the modified model respectively. Both verification results show that the model can ensure the accuracy and repeatability of the calculation. Secondly, according to the calculation results of the modified model, under the same voltage and spacing, the reduced electric field under low temperature subatmosphere pressure is larger than that under normal temperature and atmospheric pressure. The high electric field leads to the air discharge at low temperature and sub atmospheric pressure entering the streamer initiation stage earlier, and has a faster propagation speed in the streamer development stage, which shortens the overall discharge time. Finally, the discharge characteristics of the two electrode structures are compared, and it is found that the biggest difference between them is that there is a pre-ionization region near the cathode in the needle-needle electrode structure. When the pre-ionization level reaches 10~(13) cm~(-3), the propagation speed of the positive streamer remains unchanged throughout the discharge process, and is no longer affected by the negative streamer. The peak value of electric field decreases with the increase of pre-ionization level, and tends to be constant during streamer propagation. Based on the previous paper, this paper constructs the air discharge model under non-uniform electric field, complements with the previous paper, and forms a relatively complete set of air discharge simulation system under low temperature and sub atmospheric pressure, which provides a certain reference for future research.     

Discovering exact,gauge-invariant,local energy-momentum conservation laws for the electromagnetic gyrokinetic system by high-order field theory on heterogeneous manifolds

Gyrokinetic theory is arguably the most important tool for numerical studies of trarnsport physics in magnetized plasmas.However,exact local energy-momentum conservation laws for the electromagnetic gyrokinetic system have not been found despite continuous effort.Without such local conservation laws,energy and momentum can be instantaneously transported across spacetime,which is unphysical and casts doubt on the validity of numerical simulations based on the gyrokinetic theory.The standard Noether procedure for deriving conservation laws from corresponding symmetries does not apply to gyrokinetic systems because the gyrocenters and electromagnetic field reside on different manifolds.To overcome this difficulty,we develop a high-order field theory on heterogeneous manifolds for classical particle-field systems and apply it to derive exact,local conservation laws,in particular the energy-momentum conservation laws,for the electromagnetic gyrokinetic system.A weak Euler-Lagrange (EL) equation is established to replace the standard EL equation for the particles.It is discovered that an induced weak EL current enters the local conservation laws,and it is the new physics captured by the high-order field theory on heterogeneous manifolds.A recently developed gauge-symmetrization method for high-order electromagnetic field theories using the electromagnetic displacement-potential tensor is applied to render the derived energy-momentum conservation laws electromagnetic gauge-invariant.     

基于体素模型的光子外照射大鼠器官剂量模拟计算

获得外照射条件下的大鼠器官剂量,对于放射医学剂量-效应关系研究具有重要意义。本文基于大鼠微型CT图像建立大鼠体素模型,并研究光子外照射情况下大鼠器官剂量。大鼠体素模型质量323.7 g,单个体素尺寸为0.16 mm×0.16 mm×2 mm,包含大鼠大部分关键器官和组织。利用蒙特卡罗模拟程序MCNP计算获得了4种照射几何条件、21个单能(10 keV～10 MeV)平行光子束外照射情况下的器官剂量转换系数,最后对器官剂量随光子能量的变化进行了分析与讨论。     

Studies on fluid model for numerical simulation of gas discharges in color plasma displays

The fluid models of gas discharge in alternating current plasma display panel (AC PDP) cell are discussed.From the Boltzmann equation, the hydrodynamic equations are derived, but this model consumes much computational time for simulation. The drift-diffusion approximation model and the local field approximation model are obtained to simplify the numerical computation, and the approximation conditions of these two models are discussed in detail. The drift-diffusion approximation model gives more satisfactory result for PDP simulation, and the expression of energy balance equation is given completely in this model.     

Sensitivity analysis of the parameters of the hydraulic cylinder in pressure transients stepping motion for the control rod hydraulic drive system based on Model II

Hydraulic control rod drive technology (HCRDT) is a newly invented patent and Institute of Nuclear and New Energy Technology Tsinghua University owns HCRDT's independent intellectual property rights. The hydraulic cylinder is the key part of this technology, so the performance of the hydraulic cylinder directly affects the function of the integrated valve and the HCRDT. First, the theory Model II which considers the change of inlet velocity has been obtained and the pressure transient has been analyzed. Second, based on the abnormal conditions occurring in the operation of the mechanism, the working performance is obtained and the results are verified by the experiment. Third, the sensitivity analysis of the parameters of hydraulic cylinder was carried out. The results show that the calculated values are in good agreement with the experimental values. The Model II has better numerical stability than the Model I. The influence of various parameters on the operation characteristic of hydraulic cylinder is obtained. The model can be used to analyze and optimize the performance of the HCRDT.     

基于Windows的穆斯堡尔谱数据获取系统

介绍了一个原有穆斯堡尔谱仪硬件基础上开发的基于Ｗｉｎｄｏｗｓ的数据获取系统,同基于ＭＳ－ＤＯＳ的数据获限系统相比,新系统具有人机交互方便、多线程工作方式、充分利用Ｗｉｎｄｏｗｓ资源等特点。     

基于同步辐射光源的光电导探测器标定系统

将门控积分方法运用到光电导探测器的灵敏度标定中,发展了一套在北京同步辐射装置(BSRF)上对光电导探测器进行定时测量的方法,给出了利用这套标定系统在BSRF软X光站上对光电导探测器的测量结果。     

Development of regional downscaling capability in STEAMER ocean prediction system based on multi-nested ROMS model

Oceanic regional downscaling capability was implemented into Short-Term Emergency Assessment system of Marine Environmental Radioactivity (STEAMER) developed by Japan Atomic Energy Agency to enable us to predict more realistically the oceanic dispersion of radionuclides at higher spatiotemporal resolutions for broader applications. The system consisted of a double-nested oceanic downscaling circulation model with tidal forcing and an oceanic radionuclide dispersion model. This system was used to comparatively examine downscaling and tidal effects on the dispersion of radionuclides hypothetically released from the Fukushima Daiichi Nuclear Power Plant in the colder season. The simulated dissolved ¹³⁷Cs distribution was different from that obtained using coarser-resolution models because downscaling enhanced both horizontal and vertical mixing. The suppression of horizontal mixing and the promotion of vertical mixing by tidal forcing synergistically reduced offshore ¹³⁷Cs transport. In addition, the submesoscale effects strengthened the three-dimensional ¹³⁷Cs fluctuations by <10 times, while the tidal effects promoted slightly increased the intensity of three-dimensional ¹³⁷Cs fluctuations by approximately 3%. This indicated that the submesoscale effects substantially surpassed tidal forcing in oceanic mixing in the coastal margin off Fukushima in the colder season.     

基于RTLinux的硬X射线调制望远镜

硬X射线调制望远镜的电子学系统中的数据管理系统完成望远镜的数据获取、传输、管理和与卫星平台的通讯功能,需要很高的稳定性和实时性能．介绍了基于实时操作系统RTLinux的数据管理系统的设计。     

一种针对多机组事故的操作干预水平应急决策辅助系统

操作干预水平(OIL)是指对应于某一特定公众防护行动通用干预水平的易于测量的辐射量,用于在核事故期间直接与监测结果比较给出应急防护行动建议。福岛核事故后,我国核应急准备和响应向着多机组方向发展,本研究提出了一种针对多机组事故优化的OIL应急决策辅助系统,将每个机组发生的事故后果进行单独计算和评价,最后将它们对环境辐射后果的贡献进行迭加并代入原先计算公式中,即得到多机组事故下的OIL值。在优化方法的基础上,系统实现了单机组和多机组事故情景下的OIL查询、计算、修正以及后续的应急辅助决策功能。目前,该系统已应用于秦山、田湾、宁德、阳江等核电基地,其模式和功能在实际应用中得到了不断验证和完善,为核事故应急提供了重要的辅助决策手段和工具。     

图像仿真在数字辐射成像系统指标估算中的应用

通过计算机模拟的方法改进了^60Co集装箱检测系统的指标估算的方法，结果CI和IQI指标估算值与实测值较好地吻合。     

基于故障树的复杂系统故障诊断软件设计研究

可靠性和安全性要求较高的复杂系统对故障诊断工作的要求也很高。根据系统在设计、运行阶段工作中建立有大量的故障树模型的特点,本文将故障树分析方法与基于知识的方法相结合,提出了一种基于故障树的复杂系统故障诊断方法,并且开发了原型系统,实现了对车载大气光学参数测量系统的快速、智能诊断。     

Fast data acquisition system based on digital oscilloscopes for fluctuation measurements in a long pulse JT-60U tokamak plasma

We have developed a new data acquisition (DAQ) system with fast sampling rate for fluctuation measurements in a long pulse JT-60U tokamak plasma. This system is based on a powerful digital oscilloscope, which has a large acquisition memory up to 50 Mwords/ch, 1 MHz sampling rate and 16 bits high resolution AD convertors. The system is composed of plural digital oscilloscopes and mass storages. On this system, most of data acquisition processes are executed at each digital oscilloscope. This feature of the system leads to an advantage that the processing loads are distributed among the digital oscilloscopes. This system has been successfully employed for measurements of various fluctuations obtained through magnetic probes, beam emission spectroscopy and so on. The size of the acquired data using this system has reached up to 10 GB/shot so far. It has demonstrated that this system is very powerful for data acquisition of multi-channeled signals with high time resolution in a long pulse plasma.     

Radially and azimuthally dependent resonance self-shielding treatment for general multi-region geometry based on a unified theory

A unified resonance self-shielding method, which can treat general sub-divided fuel regions, is developed for lattice physics calculations in reactor physics field. In a past study, a hybrid resonance treatment has been developed by theoretically integrating equivalence theory and ultra-fine-group slowing-down calculation. It can be applied to a wide range of neutron spectrum conditions including low moderator density ranges in severe accident states, as long as each fuel region is not sub-divided. In order to extend the method for radially and azimuthally sub-divided multi-region geometry, a new resonance treatment is established by incorporating the essence of sub-group method. The present method is composed of two-step flux calculation, i.e. ‘coarse geometry + fine energy’ (first step) and ‘fine geometry + coarse energy’ (second step) calculations. The first step corresponds to a hybrid model of the equivalence theory and the ultra-fine-group calculation, and the second step corresponds to the sub-group method. From the verification results, effective cross-sections by the new method show good agreement with the continuous energy Monte-Carlo results for various multi-region geometries including non-uniform fuel compositions and temperature distributions. The present method can accurately generate effective cross-sections with short computation time in general lattice physics calculations.     

基于辐射探测系统的核部件储存库房安全监控系统脆弱性研究

核部件储存库房安全监控是核裁军监控链的重要组成部分,为进一步提高核部件储存库房的安全性、可靠性,本文结合脆弱性研究最新进展,发展并给出了库房安全监控系统脆弱性的概念,并基于辐射探测系统开展了库房安全监控系统脆弱性影响因素、量化评估分析方法研究。研究结果表明,核部件储存库房安全监控系统脆弱性影响因素较多,脆弱性较大,亟需进一步研究以确保核裁军监控链高度安全可靠可控有效。     

基于B/S方式的远程地震波形浏览系统设计与实现

基于网络B/S模式地震波形数据实时浏览,在现代地震研究与数据服务方面具有重要作用并且技术亟待提高.全面阐述了基于B/S方式实现地震波形数据远程实时浏览的基本思路,软件实现方法、系统体系结构框架以及编程实现.重点研究了远程数据调用、大数据的显示以及JAVA程序开发等关键技术问题.