速调管走廊抗干扰技术研究

合肥国家同步辐射实验室速调管走廓内存在着高频电磁泄漏,为确保走廓内的通讯信号不被干扰,采用抗干扰技术对泄漏噪声进行了抑制,并对抑制前后的泄漏噪声作了对比测试,结果显示了所采用的抗干扰技术的有效性。     

S波段D4009大功率速调管相位稳定性测试

本文介绍D4009脉冲大功率速调管电压-相位调制灵敏度测试原理及线路,并对测试结果进行了分析。在注电压～200 kV时,D 4009管的电压-相位调制灵敏度～6°。     

CRAFT LHCD速调管激励源综合测试系统设计

针对聚变堆低杂波电流驱动系统速调管激励源功能特性多样的特点和微波组件繁多的问题,设计了具备多参数测量和自分析诊断能力的速调管激励源综合测试系统。该系统的测量部分能够对速调管激励源输出微波信号的频率特性、开关特性、功率特性和移相特性进行实时检测;其控制诊断部分的设计基于PXI系列工控硬件和Qt集成开发环境,能够对测试过程进行全局规划调度、数据采集存储和智能故障诊断,并能生成测试报告。实际运行表明,该综合测试系统可以24 h连续无人化工作,提高了速调管激励源的测试和故障诊断效率。     

北京谱仪附近空间电磁噪声测量和抑制工作

当北京正负电子对撞机（BEPC）提供的e^ /e^-束流通过北京谱仪（BES）时,在对撞区附近会产生一个空间电磁信号。采用单点测量和矩阵测量等方法,对其进行时域和频域测量及分析。为寻找BES附近的干扰噪声源,提供了非常有益的数据。确认了静电分离器的屏蔽改进效果,并且找到了BES附近另一个干扰噪声源-束流管道上安装DCCT（直流电流传感器）位置附近的陶瓷结构的不连续性而泄漏的电磁波。对其采取了屏蔽、接地等一系列电磁兼容措施,极大地净化了BES附近的空间电磁环境,提高了BES对BEPC束流的利用率,改善了BES数据的可靠性。     

EAST速调管快速保护系统的研制

介绍了EAST速调管快速保护系统的研制.EAST速调管快速保护系统的功能是对磁场电流,主回路电流,管体电流和打火保护信号进行监测.当这些信号超过设定的阈值,快速保护系统立即给后面的控制系统发出过阈报警信号,从而快速保护速调管.     

200MeV电子直线加速器隧道内及速调管走廊内的瞬发辐射场

直线加速器隧道内存在着一个具有特定时间结构和空间分布的强瞬发辐射场,它主要由轫致辐射和中子组成。用丙氨酸剂量计和电子自旋共振（ＥＳＲ）方法进行测量,得到隧道内关键位置的三维空间辐射场分布。这对于了解加速器的运行状态和射线积累剂量对各种有机材料的损伤程度是有意义的。速调管走廊内的辐射场主要是由于大功率速调管的运行造成的,因各个速调管参数不一致而使各点的辐射剂量呈现出较大的差异。但速调管走廊内的辐射水平不太高,故允许人员有条件地进入其中工作,因此在辐射安全联锁系统中将其定为可绕过的联锁点。本文简单介绍国家同步辐射实验室这两处辐射场的特点,并对其测量的方法和结果进行了叙述和讨论     

BESⅢ电磁量能器宇宙线测试与刻度

通过对北京谱仪Ⅲ(BESⅢ)电磁量能器(EMC)进行宇宙线测试来检验EMC各个探测单元的电子学系统工作是否正常,电缆连接是否正确.利用实验室测量得到的晶体相对光产额(RLY)系数对无磁场的宇宙线数据进行刻度,然后与蒙特卡洛(MC)宇宙线样本进行比较,得出每个晶体探测单元的宇宙线能量刻度常数,以此作为EMC的初始能量刻度常数.     

椭圆极化波对大鼠电磁暴露的数值模拟计算

以椭圆极化波作为波源进行大鼠电磁暴露数值模拟,比较了多个入射方向上大鼠电磁暴露的全身平均比吸收率(WBASAR).结果发现,椭圆极化波的WBASAR随椭偏率的改变而变化,同时受到入射方向和旋向的影响.将此结果与同方向上线极化波的辐照结果比较发现:在入射功率相同的条件下,椭圆极化波和线极化波电磁暴露的WBASAR结果存在...     

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。     

SXFEL装置上速调管输入输出特性曲线的线性化

在上海软X射线自由电子激光(Soft X-ray Free-electron Laser,SXFEL)中的微波低电平控制系统中,通过对各速调管的输出信号进行测量和控制,保证加速器的稳定运行并且达到技术指标。另一方面,SXFEL中的脉冲速调管的输入输出特性存在非线性的关系,这种电子管放大器不理想的非线性特性会导致微波低电平(Low Level Radio Frequency,LLRF)控制系统调节的效率降低。基于SXFEL装置,采用基于现场可编程门阵列(Field Programmable Gate Array,FPGA)的数字预失真方法,在LLRF控制系统中设计了一套实现高功率速调管放大器线性化的在线系统。S波段加速装置和其相应的东芝E3730A速调管及高压调制器和低电平系统实地测试结果表明,在LLRF控制系统中建立的在线系统能够有效补偿速调管带来的非线性问题,提高微波低电平控制系统的精度及准确性。     

NSRL 200MeV电子直线加速器的速调管真空保护装置

报道了一种能保护高功能速调管安全的速调管真空保护装置。该装置保护动作时间≤１５ｍｓ，在强电磁干扰速调管走廓中能稳定可靠地工作。     

Production and test of sPHENIX W/SciFiber electromagnetic calorimeter blocks in China

The sPHENIX experiment is a new generation of large acceptance detectors at the relativistic heavy ion collider at Brookhaven National Laboratory,with scientific goals focusing on probing the strongly interacting Quark-Gluon plasma with hard probes of jets,open heavy flavor particles,and Y production.The EMCal detector,which covers the pseudo-rapidity region of|η|≤ 1.1,is an essential subsystem of sPHENIX.In this study,we focused on producing and testing EMCal blocks covering a pseudo-rapidity of|η|∈[0.8,1.1].These,in conjunction with the central pseudo-rapidity EMCal blocks,significantly enhance the sPHENIX physics capability of the jet and(Y)particle measurements.In this paper,the detector module production and testing of sPHENIX W-powder/scintillating fiber(W/ScFi)electromagnetic calorimeter blocks are presented.The selection of the tungsten powder,mold fabrication,QA procedures,and cosmic ray test results are discussed.     

电磁脉冲辐照对小鼠受孕率、胚胎发育和子代的影响

电磁辐射的危害、尤其对胚胎发育及子代的影响已引起人们的高度关注[1,2]。本研究对BALB/C雌性小鼠或雄性小鼠进行电磁脉冲照射(场强95.41kVm-1、3×106次和4×106次脉冲),受照雌鼠或雄鼠与未照的雄鼠或雌鼠于照后1天和2月分别交配,用胚胎畸形学的方法分别观察各组雌鼠的受孕率、孕鼠所产的胚胎数及其子代性别比等。经3×106次脉冲的电磁脉冲辐照后的各组,均留一部分孕鼠让其自然分娩,饲养仔鼠,仔鼠成年后采用Y型电迷宫法检测子代小鼠的学习记忆能力,同时将仔代小鼠放置于50℃金属平面上测量其对热伤害感受的反应潜伏期。经3×106次辐照…     

The role of the eigenvalue separation in reactor dynamics and neutron noise theory

The concept of eigenvalue separation (ES) was introduced in the past for the characterisation of the space-time kinetics of reactor transients, and the stability properties of large loosely coupled cores. However, most of the investigations reported so far concern the determination of the ES itself either from static calculations, or from measurements of the flux tilt or neutron noise cross-correlations. Conclusions on system behaviour were only drawn from the properties of the static eigenfunctions, comparing non-perturbed and perturbed systems, without explicitly solving the time- or frequency-dependent problem. In this paper, we explore the role of the ES on the neutronic response of a critical core to small stochastic perturbations (neutron noise); in particular, the spatial and frequency characteristics of the arising neutron noise as a function of the ES, as well as the spatial structure of the perturbation. It is shown that for systems with small ES and non-uniform perturbations, point kinetics will not dominate even for very low frequencies. The results lend some further insight into the origin and properties of the various types of boiling water reactor instabilities.     

电磁脉冲辐射对小鼠睾丸Occludin表达的影响

探讨电磁脉冲辐射对小鼠睾丸血-睾屏障紧密连接蛋白Occludin表达的变化.采用场强为400 kV/m的辐射场对30只成年雄性Balb/c小鼠进行200次重复全身照射,另30只假照射.于辐照后1、7、14、21和28d分别取小鼠睾丸组织制备石蜡标本或提取组织蛋白和mRNA,使用Real-time PCR、Western...     

A design and characteristic experiment of the small annular linear induction electromagnetic pump

A small-scale annular linear induction electromagnetic pump (ALIP) of the externally-supported-in-pipe type with a flowrate of 60 L/min and a developed pressure of 1.3 bar was developed for the circulation of sodium liquid metal. The developed pressure and the efficiency of the pump were analyzed on the change of the pump-design variables by using an equivalent circuit method. The pump designed was manufactured with the consideration to the material and functional requirements of a chemically-active sodium environment. The silicon–iron steel plates with high magnetic permeability and alumina-dispersion-strengthened-copper bands were used as cores and coils of the pump electromagnet for operating in a high temperature. Each turn of the coil was insulated by an asbestos band to protect against an electrical short at a high temperature. Stainless steel compatible with sodium was selected as a structural material. The completed pump was installed in the sodium experimental loop system. At temperatures of 150 °C and 350 °C, the performance of the ALIP (including the P–Q characteristic) was tested by changing the electrical input. The measurements showed that the pumping flowrate and the developed pressure were increased as the input current, voltage and power increased. On the other hand, the developed pressure was decreased with the increase of the flowrate. At the nominal input current and voltage, the developed pressure was 1.25 bar with the relative error of 3.8% compared with the prediction of 1.3 bar at 150 °C, where the flowrate was 54 L/min. The test on the pump showed good agreement with the theoretical calculation with some experimental errors.     

Calculation of the ex-core neutron noise induced by individual fuel assembly vibrations in two PWR cores

Calculation of the neutron noise induced by fuel assembly vibrations in two pressurized water reactor(PWR) cores has been conducted to investigate the effect of cycle burnup on the properties of the ex-core detector noise. An extension of the method and the computational models of a previous work have been applied to two different PWR cores to examine a hypothesis that fuel assembly vibrations cause the corresponding peak in the auto power spectral density(APSD) increase during the cycle. Stochastic vibrations along a random two-dimensional trajectory of individual fuel assemblies were assumed to occur at different locations in the cores. Two models regarding the displacement amplitude of the vibrating assembly have been considered to determine the noise source. Then, the APSD of the ex-core detector noise was evaluated at three burnup steps. The results show that there is no monotonic tendency of the change in the APSD of ex-core detector; however, the increase in APSD occurs predominantly for peripheral assemblies. When assuming simultaneous vibrations of a number of fuel assemblies uniformly distributed over the core, the effect of the peripheral assemblies dominates the ex-core neutron noise.This behaviour was found similar in both cores.     

基于主成分变换的核径迹图像噪声分析及消除

由于径迹片在生产、贮存和蚀刻过程中易形成杂质、气泡及划痕,导致所获取的核径迹图像常常伴随着各种类型的噪声,因此如何有效地去除噪声的影响,为后续核径迹图像识别、分类与计数奠定基础,是图像预处理阶段的一个重要任务.本文选择一组聚焦性能好的核径迹图像,基于主成分变换和傅立叶变换的噪声分析,使用高斯低通滤波器进行去噪处理.实验结果表明了该方法的有效性和可操作性.