基于SOPC技术的EAST定时与同步系统

定时与同步系统是托卡马克装置实现等离子体放电流程实时控制的基础。基于SOPC技术研制的EAST分布式定时与同步系统可为各子系统提供精确时钟和同步触发信号,使装置各子系统按照预先设定好的流程运行,实现EAST等离子体放电实验时序的精确控制。EAST定时与同步系统的时序精度高于1μs,可以满足当前EAST实验的需要。     

EAST分布式定时同步系统的实现

分布式定时同步系统在国家大科学工程EAST中有重要作用,它用于同步EAST各子系统精准投入实验的时序。分布式定时同步系统利用PXI工业级设备并结合虚拟仪器技术实现定时同步系统,可提供1 Hz～80 MHz频率的参考时钟信号,产生1 ms～6 872 s延迟触发信号（精度达10 ns）。该系统能采集信号,并能根据检测的信号实时触发相应处理机制。分布式定时同步系统精度高且运行稳定可靠,已成功应用于2010年秋季EAST放电实验。     

EAST托卡马克激光吹气杂质注入系统控制系统设计及测试

开展托卡马克等离子体中杂质输运与杂质控制研究对于提升等离子体约束性能与保障装置安全有重要意义。为了在EAST(Experimental Advanced Superconducting Tokamak)托卡马克装置上开展杂质输运研究,需要发展一套用于注入示踪杂质粒子的激光吹气（Laser Blow-off,LBO）微量杂质注入系统。本文描述了一种用于EAST托卡马克装置上LBO系统的控制系统设计过程与测试结果。该系统采用了全新的自动控制流程,使得系统可以重复、定量地向EAST等离子体注入不同元素的示踪杂质粒子。该设计通过STM32单片机系统实现对聚焦透镜位移、激光器被触发时刻的准确控制,且激光光斑直径可调,以改变杂质注入量。测试结果显示,系统能快速检测到外触发信号并实现精确定时,激光光斑聚焦位置误差小于0.40 mm,达到激光吹气杂质注入实验要求。本研究对在EAST装置上开展等离子体杂质输运研究具有重要意义。     

EAST安全巡检与联锁保护系统设计与实现

全超导托卡马克系统不同于常规托卡马克系统,有独特的运行特性和更高的运行风险.安全巡检与联锁保护系统是托卡马克系统中必不可少的-个重要组成部分.EAST (Experimental Advanced Superconducting Tokamak)是我国自主研发的世界上第-个全超导托卡马克系统.本文详细分析了EAST的主要运行风险,针对运行风险制定的各子系统的安全监测和保护机制,及分布式 EAST 安全巡检与联锁保护系统的系统体系结构和系统的实现.EAST 已在中国科学院等离子体物理研究所建成并于2006年9月运行成功,获得等离子体,本系统已在EAST装置的2006-2007年度的几轮实验中成功应用.     

EAST安全联锁监管系统设计

全超导托卡马克装置(FullSuperconductingTokamak,FST)所有主要磁体均为超导磁体,其运行风险大大高于现有的其它超导托卡马克。EAST(ExperimentalAdvancedSuperconductingTokamak)是一个全超导托卡马克装置,为了避免人员和装置出现意外事故,建立了联锁系统与安全系统。安全联锁监管系统位于EAST联锁系统与安全系统的顶层,协调各分控系统的安全运行。根据EAST安全联锁系统的需求,采用可编程逻辑控制器、联锁信号光纤网和光电转换设备,建立了安全联锁监管系统,实现了事件收集、信号循环扫描、保护动作输出、系统状态和故障日志信息记录和实时监控等功能。该系统实际扫描周期平均值约0.7ms,最大值约3ms,达到了EAST安全联锁系统的要求。     

EAST全超导托卡马克装置失超保护检测技术的现状及发展

EAST装置是"九五"国家重大科学工程项目之一,做为世界上第一个全超导托卡马克装置,其纵场和极向场线圈全部由超导磁体组成,进行安全,准确,有效的失超保护是装置安全运行的首要环节。如何在全超导托卡马克装置这样复杂的电磁环境进行失超检测在世界上也无先例可寻。EAST上失超检测系统经过几十轮单饼超导线圈实验及两轮装置正式放电实验后逐步建立和完善起来,并已通过工程验收达到装置实验运行要求。主要介绍了EAST超导装置失超检测系统的基本结构和检测原理,同时还简述失超检测技术的发展并给出了实验结果。     

EAST4.6GHz/4MW低杂波电流驱动系统隔直器优化设计

为了研究全超导托卡马克稳态高参数等离子体性能,2008年在EAST托卡马克装置上研制并成功建成了一套能最大传输2兆瓦,工作频率是2450MHz的低混杂波电流驱动系统,要实现低杂波长时间地维持等离子体电流,还需要对低杂波系统的输出功率大小及运行时间长度提出更高要求,拟研制一套波源输出功率4 MW,中心频率4.6GHz,波谱范围为1.7< N_(//)< 2.5,运行脉冲宽度0～1000秒低杂波电流驱动系统.在EAST4.6GHz/4MW低杂波电流驱动系统中,因为速调管放大器和低杂波天线有共同的接地点,速调管放大器电源为负高压,有接地点,低杂波天线有接地点,并且和EAST托卡马克相连,在系统中要求不能有两个接地点,所以要通过隔直器来隔断托卡马克和速调管之间的的直流通路.论文详细介绍了隔直器的原理和设计过程,在以4.6GHz为中心频率,150MHz的频带范围内,隔直器各个端口微波性能良好.     

EAST托卡马克的中性束注入方案

高能中性束注入(Neutral beam injection,NBI)是核聚变装置托卡马克采用的芯部辅助加热和非感应电流驱动主要手段之一.本文介绍了国家大科学工程全超导托卡马克实验装置(Experimental advanced super-conductingtokamak,EAST)上的高能NBI加热方案及注入器的工程要求,并讨论了中性束在EAST等离子体中的传输等相关问题.     

EAST全超导托卡马克高分辨率EUV光谱仪诊断系统

EAST全超导托卡马克装置上建立一套极紫外(EUV)光谱诊断系统,用于高温等离子体高电离态杂质线辐射研究.该系统利用1200 l/mm凹面变线距全息光栅作为分光元件,工作波段50-500(A),波长分辨率Δλ-0.16(A)(186.6?),时间分辨为20 ms,空间观测范围为0-450 mm,基本覆盖EAST全超导托...     

EAST托卡马克装置上TOF谱仪屏蔽体设计的模拟计算

采用中子飞行时间谱仪测量EAST装置上的中子能谱时,对于散射量的屏蔽是能否得到有效数据的关键。本文利用三维蒙特卡罗输运程序,通过对EAST托卡马克装置的细致建模,对大厅环境的散射量进行了模拟计算,在考虑了各散射体贡献的基础上,采用叠代计算的方法,提出了满足双晶TOF谱仪屏蔽体的优化设计方案,为后续EAST装置上TOF的有效运行提供了关键技术支持。     

The research about the time-effect of the wettability on the wool surface treated by the Ar plasma jet in the atmospheric pressure

A facility which is called atmospheric pressure and normal temperature plasma jet was introduced in this paper. After the wool surface was treated by this kind of facility with Ar in different irradiating times, the time-effect of the fabric wettability has been weakened, and if the parameters of the irradiating time and the voltage of the facility are appropriate, the time-effect of wettability can be effectively inhibited. With the stable wettability, the fabric can be dressed without PVA (polyvinyl alcohol) which can cause lager pollution in the textile field, so the method without the time-effect of the textile wettability will be useful in the field of clean textile production. Undoubtedly, the stable wettability of textile surface was caused by the stable hydrophilic molecules on the textile surface. Thus, the reaction process and results on the textile surface treated by plasma needs to be studied to optimize the parameters of the irradiating time and the voltage of the plasma jet. So the initial experimental studies on the optimization of the parameters of the plasma jet were discussed in this paper, and the authors believe that the method without the time-effect also can be used in other fields of plasma application.     

Effect of the Discharge Voltage on the Performance of the Hall Thruster

In this paper,a two-dimensional physical model is established according to the discharging process in the Hall thruster discharge channel using the particle-in-cell method.The influences of discharge voltage on the distributions of potential,ion radial flow,and discharge current are investigated in a fixed magnetic field configuration.It is found that,with the increase of discharge voltage,especially during 250-650 V,the ion radial flow and the collision frequency between ions and the wall are decreased,but the discharge current is increased.The electron temperature saturation is observed between 400-450 V and the maximal value decreases during this region.When the discharge voltage reaches 700 V,the potential distribution in the axis direction expands to the anode significantly,the ionization region becomes close to the anode,and the acceleration region grows longer.Besides,ion radial flow and the collision frequency between ions and the wall are also increased when the discharge voltage exceeds 650 V.     

Detecting the meteoroid by measuring the electromagnetic waves excited by the collision between the hypervelocity meteoroid and spacecraft

The electromagnetic pulse excited by the collision between a hypervelocity meteoroid and a spacecraft is studied both numerically and theoretically. It is found that there are two kinds of electromagnetic pulse. The high-frequency electromagnetic pulse may be excited by the sum of all the electric dipoles. Each electron can be considered as an electric dipole. The low-frequency electromagnetic pulse is produced by the Langmuir oscillation of electrons. The energy flux density and the duration time of the excited low-frequency electromagnetic pulse by the meteoroid are also studied in the present paper. It is shown that the energy flux density increases as either the impact speed or the mass of the meteoroid increases. It is also shown that the duration time decreases as both the impact speed and the mass of the meteoroid increase. By measuring the strength and the duration time of the electromagnetic pulse excited by the collision between the hypervelocity meteoroid and spacecraft, we can estimate the speed and the mass of the hypervelocity meteoroid, which will be helpful in space flight and space exploration.     

Current status of the engineering design of the test modules for the IFMIF

Under Broader Approach (BA) Agreement between EURATOM and Japan, IFMIF/EVEDA (International Fusion Materials Irradiation Facility/Engineering Validation and Engineering Design Activities) has been performed since the middle of 2007. IFMIF presents three main facilities (the Accelerator Facility, Li Target Facility and Test Facilities). A previous design of IFMIF was summarized in the comprehensive design report [1]. The present EVEDA phase aims at producing a detailed, complete and fully integrated engineering design of IFMIF. The delivery of the “Intermediate IFMIF Engineering Design Report” is foreseen mid-2013. The goal of IFMIF is to obtain the indispensable design database to allow the design and licensing of DEMO and ensuring commercial reactors thanks to the materials data set obtained from planned evaluation tests such irradiations in high flux test modules (HFTM-vertical rig, HFTM-horizontal rig), medium flux test modules (creep fatigue test module, tritium release test module, liquid breeder validation module) and low flux test modules of IFMIF. In addition, the Startup Monitoring Module will be used for IFMIF commissioning. This paper is summarizing the overall current progress status of the engineering and conceptual design of the test modules in IFMIF/EVEDA.     

右侧卧位对左室下壁心肌衰减校正价值的初探

为探讨右侧卧位对左室下壁心肌衰减校正和心梗诊断的价值,对31名正常者和22名冠心病病人同时进行了仰卧位和右侧卧位的^99mTc-MIBI静息心肌显像,病人均作了冠状动脉血管造影。观察正常者在不同体位时下壁形态并通过靶心图计算各区象素计数。判定不同体位各供血区病变诊断的敏感性和特异性。结果表明,右侧卧位时下壁形态显示较好而且计数明显增高,P＜0．05,同时对右冠状动脉病变的敏感性和特异性分别为100％和81．8％,较仰卧位明显提高,结果提示,右侧卧位不仅可使下壁衰减得以校正而且可提高对心梗诊断的准确性。     

EAST强流离子源电源系统的初步测试运行

测试NBI大功率强流离子源的综合测试台正在建设,已研制了离子源等离子体发生器电源系统、等离子体电极高压电源及梯度极分压器、抑制极负高压电源等电源系统,以及高压传输线及缓冲器,在测试台上开展了对EAST中性束注入器第一台兆瓦级强流离子源样机进行整体电源系统测试和离子源起弧放电的初步测试,完成了离子源电源系统初步性能测试及...     

周期计设计中的分段处理问题

本文通过对反应堆周期计响应时间、过冲量及噪声问题的分析,探论周期测量和周期保护信号分别处理的必要性和可能性,目的在于改善周期信号的品质,提高周期计的使用效果。本文首次报道了差分型周期计的响应函数。     

Tectonic Factor in the Formation of the Radon Fields in the Atmosphere of the Tashkent Subway

Using the standard radiometers -GUARD PQ2000M and gamma-TRACER (Germany) and semiconductor spectrometers RATON (Uzbekistan), the radon fields were investigated in underground service enclosures and on the platforms of the Tashkent subway stations located on territories with different geotectonic characteristics. It is shown that the tectonic factor influences the formation of radon fields in the air in the subway station. 4 figures, 1 table, 7 references.     

氡室平衡状态对监测曲线的影响及修正

氡在氡室中是一种动态稳定状态,为了更准确的监测氡室中氡浓度的变化,文章主要对氡室首次补氡期间氡及子体的平衡状态的变化进行理论推导和平衡系数对FD125监测曲线的影响进行了探讨并进行了修正,取得了比较好的效果,为氡室氡浓度监测曲线修正提供了一种方法.