一维时空分辨诊断技术在Z-pinch实验中的应用

在Angara-5-1装置上进行的丝阵Z-pinch实验中,红光塑料闪烁体薄膜将X光转换为可见光,通过光纤阵列、光纤传像束传输至可见光条纹像机(OSC),紧贴于像机屏幕的光纤锥将信号耦合至CCD进行记录,提供丝阵一维条纹像,观察丝阵负载Pinch区X射线辐射空间分布信息随时间的演化过程.实验中系统时间分辨4.3ns,空间分辨0.3mm.负载采用单层丝阵与双层丝阵.研究结果表明,X光辐射波形前沿上升时间越快,功率峰值越高;双层丝阵构形改善了内爆同步性;等离子体的内爆动能与电流成正比,电流愈大,等离子体的动能也愈大,X光辐射能量与电流成正比.     

Z-pinch靶用氘代聚苯乙烯丝的研制及表征

为满足Z-pinch D-D出中子实验对固体燃料容器的要求,设计了1套简易的拉丝装置,并用聚苯乙烯(PS)为原料进行了工艺条件实验,确定出较佳的实验条件。以1 g氘代聚苯乙烯(DPS)为原料,在确定出的实验条件下,控制合适的拉丝速度,可拉出直径为30~100μm、均匀、具有一定强度的DPS丝。所制备的DPS丝在Z-pinch D-D出中子实验中得到了应用,取得了最大中子产额为2×109cm-1的实验结果。     

兆安级电流下Al丝阵的芯晕结构抑制研究

为了抑制丝阵Z箍缩中金属丝在电流早期电爆炸形成的芯晕结构,基于强光一号加速器,利用二级丝阵负载开展了Al丝阵早期物理状态的调控研究。通过陡化预脉冲和调整二级丝阵的参数,实现了负载Al丝的全部汽化,抑制了芯晕结构的产生,气态Al丝芯的平均直径约为1.80 mm,且沿轴向均匀分布,降低了丝阵消融引起的初始不稳定性。若丝长度和直径保持不变,反转型丝阵的关断时间主要取决于Al丝的丝数;反转型丝阵关断后,气态丝芯在主电流脉冲作用下迅速电离并开始内爆,磁瑞丽泰勒不稳定性迅速发展,内爆等离子体流沿轴向呈周期性调制分布,调制波长约为650 μm。Al丝阵初始状态的改变,有效抑制了丝的消融过程,消除了先驱等离子体,在内爆后期降低了拖尾质量,提高了箍缩品质。     

一种线阵CCD显微测量系统的标定方法

使用参数分离标定的方法对微小物体的在线高精度测量控制系统进行标定。研究了线阵CCD显微相机的成像模型,提出相机的内外参数分离标定方法,在实验室模拟工业环境下和工业现场分别标定相机的内参数和外参数。参数分离标定的方法简化了工业现场的标定任务,相机可应用于多种测量环境,且标定模板容易制作。实验证明该标定方法精度较高,标定后相机的极限误差为2.05μm。     

CCD相机在观测弹丸消融过程中的应用

我们利用高速、高时空分辨率面成像CCD相机在HL-1M弹丸注入方向上对弹丸的消融全过程进行了观测,拍摄到了HL-1M等离子体中注入氢弹丸时的H_α辐身照片。 弹丸与等离子体的相互作用是十分复杂的过程,大致可以分为两个阶段:第一阶段弹丸表面被加热而升华;第二阶段是蒸发、消融,之后弹丸被中性气体所包围,形成云。其消融率为其中,n_e/cm~(-3)为电子密度,T_e/eV为电子温度,r_p/cm为弹丸半径,M_i为弹丸质量(原子单位)。     

ITER软X射线相机冷却实验监控系统

作为ITER重要的物理诊断之一,软X射线相机在装置烘烤时将面临高达250℃的环境温度。因此,冷却上限温度仅为75℃的相机探测器至关重要。为了验证冷却效果,所进行的冷却实验采用基于EPICS的监控系统管理实验过程及结果,实现了数据采集、存储、检索以及设备控制等功能,本设计创新之处在于高效的将所有采集控制算法通过EPICS集中实现。本文对监控系统的功能需求、监控参数、硬件及软件设计和测试结果进行了详细描述。结果表明,监控系统运行稳定,不仅为软X射线相机冷却实验提供可靠支撑,也为EPICS在监控系统中的推广提供借鉴。     

大动态针孔相机在ICF激光焦斑诊断中的应用

在神光Ⅲ原型装置上,作为主要诊断设备的X光针孔相机发挥了重要的作用.论文提出了一种基于4×4的多针孔阵列板,该针孔阵列板具有测量动态范围大、视场大、瞄准精度要求降低、更换滤片次数减少等特点.同时在神光Ⅲ原型实验中使得针孔相机的实验数据获取率得到提高.     

蒙特卡罗方法在圆柱型多丝正比室多路望远镜系统中的应用

基于圆柱型多丝正比室的多路望远镜系统具有良好的粒子鉴别性能和真事件判选特性，可同时进行多个反应角度的测量，也可同时进行效应谱和本底谱的测量，适合用于研究快中子引起的出射带电粒子的反应。简要介绍了该系统的基本结构及特点，并说明蒙特卡罗方法在该系统中的实际应用情况。     

软X射线功率谱仪测量系统在"强光一号"的丝阵实验

闪烁体和光电管组成的软X射线功率谱测量系统,在西北核技术研究所的"强光一号"加速器上,测量得到了各种丝阵靶的X射线辐射功率波形,并对测量结果进行了分析.     

指数时间差分方法在材料辐照损伤模拟计算中的应用

速率理论是一种用于模拟辐照诱导材料微观结构长时间演变过程的重要方法,其计算难点在于对大规模刚性的速率理论方程的数值求解。本文首次采用指数时间差分方法实现对速率理论方程的并行数值求解,分别给出了指数时间差分方法在热老化导致空洞演化和辐照诱导位错环演化模拟中的实现形式。测试结果证实了指数时间差分方法对大规模速率理论方程并行求解的可行性,有助于实现辐照诱导材料微结构长时演化行为的高效模拟。     

A compact gamma camera with scintillation array and parallel-hole collimator

A new compact gamma camera for small object imaging has been developed. It consists of a pixelized Nal（T1） scintillator array coupled to a position sensitive photomultiplier tube （Hamamatsu R2486） with a parallel-hole lead collimator. The compact camera has better spatial resolution than Anger camera. The average value of intrinsic spatial resolutions is 2.3 mm （FWHM）. The overall spatial resolution （FWHM） is 3, 5 and 6 mm at 0, 2.5 and 3 mm SCD （source-to-collimator distance）, respectively. The phantom studies with the compact camera have demonstrated that parallel-hole collimator gamma camera is a practical technique for nuclear medicine application.     

Discharge and post-explosion behaviors of electrical explosion of conductors from a single wire to planar wire array

This work deals with an experimental study of a Cu planar wire array (PWA) in air and water under the stored energy 300–1200 J. A single Cu wire is adopted as a controlled trial. Four configurations of PWA and a wire with the same mass (cross-section area) but the different specific surface areas (15–223 cm² g⁻¹) are exploded. The transient process is analyzed using high-speed photography in combination with the results of optical emission and discharge. Discharge characteristics revealed that PWA always has a higher electric power peak, early but higher voltage peak, as well as faster vaporization and ionization process than the single-wire case. Two to three times stronger optical emission could be obtained when replacing the single-wire with PWA, indicating a higher energy-density state is reached. Phenomenologically, in both air and water, single-wire load tends to develop a transverse stratified structure, while PWA is dominated by the uneven energy deposition among wires. Finally, the synchronism and uniformity of the PWA explosion are discussed.     

Primarily Experimental Results for a W Wire Array Z Pinch

Primarily experimental results are given for a W wire array Z pinch imploded with up to 2 MA in 100 ns on a Qiangguang-I pulsed power generator. The configuration and parameters of the generator, the W wire array load assembly and the diagnostic system for the experiment are described. The total X-ray energy has been obtained with a averaged power of X-ray radiation of 1.28 TW.     

用于Z箍缩诊断装置的快阀研制

Z箍缩实验滞止后期负载产生的微小碎片及其他飞溅物质会污染Z箍缩诊断系统内的光学器件,本文研制了一种基于电磁感应原理的快阀,其可用于遮断微小碎片及其他飞溅物质。根据能量守恒和电路方程,计算了快阀的运动速度、遮断时间及线圈放电电流等参数,并利用实验测量获得快阀运动速度为19 m/s,遮断时刻时间抖动为85 μs,实验测量与计算结果较为吻合。     

Comparison Between Mitigation Effects of the Finite Larmor Radius and Sheared Axial Flow on Rayleigh—Taylor Instability in Z—Pinch Implosions

A magnetohydrodynamic (MHD) formulation is derived to investigate and compare the mitigation effects of both the sheared axial flow and finite Larmor radius (FLR) on the Rayleigh-Taylor (RT) instability in Z-pinch implosions. The sheared axial flow is introduced into MHD equations in a conventional way and the FLR effect into the equations via ?/?t → -i(w+ik⊥2pi2Ωi), as proposed in our previous paper [Chin. Phys. Lett. 2002, 19:217] , where k⊥2 pi2 is referred to FLR effect from the general kinetic theory of magnetized plasma. Therefore the linearized continuity and momentum equations for the perturbed mass-density and velocity include both the sheared axial flow and the FLR effect. It is found that the effect of sheared axial flow with a lower peak velocity can mitigate RT instability in the whole wavenumber region and the effect of sheared axial flow with a higher one can mitigate RT instability only in the large wavenumber region (for normalized wavenumber k>2.4); The effect of FLR can mitigate RT     

螺旋线圈在同步辐射光源冷却系统中的应用

在冷却流体管道中插入铜质线圈的强化冷却方法可以较为显著地提高管道的对流换热系数,从而增强冷却效果,此法已在国际上的同步辐射光源中得以应用。根据现有相关文献,总结介绍了此种强化冷却方法,阐述该机构的关键结构参数与强化冷却工作机理,并对其在国际上各同步辐射光源的应用情况作出描述,同时指出关键技术问题与未来的发展趋势,从而为此强化冷却方法在我国同步辐射装置,特别是高能高热的第三代同步辐射装置冷却系统的应用提供前瞻与有益的探索。     

Study of performance of small gamma camera consisting of crystal pixel array and position sensitive photomultiplier tube

1 Introduction In recent years a great effort has been made in developing compact gamma camera to improve nu-clear medical imaging. Conventional Anger gamma camera[1] uses a NaI(Tl) scintillator block and an array of photomultiplier tube. It has large size and poor spa-tial resolution, thus it is not suitable for small object image. Though the gamma camera using planar crystal coupled with position sensitive photomultiplier tube (PSPMT[2]) could greatly improve spatial resolu-tion,[3-5] pl…     

法拉第筒阵列探测器在电子束束流均匀度测量中的应用

描述一种法拉第筒阵列探测器,其由拦截式法拉第筒、抑制电极、绝缘层和底座等组成。应用该探测器测量了电子加速器的束流均匀度,计算了被辐照样品的吸收剂量,将为电子加速器的改造、生物辐照、材料辐照提供重要参数。