激光等离子体X射线成像诊断研究

为了诊断激光等离 子体X射线二维空间信息,基于Bragg衍射原理建立了等离子体X射线背光成像系统,其核心 元件为石英球面弯曲晶 体,弯曲半径为143mm。在中国工程物理研究院神光III原型激光装 置上,利用建立的系统,进行了单色X射线背光成像实验,激光聚焦到平面 Mg靶中心聚爆产生高温等离子体X射线为背光源,成像物体为15μm ×15μm网格阵列,X射线CCD得到了清晰的Mg靶 单色X射线二维网格图像。通过对背光图像分析,在7.8mm×2.6mm的视场范围,成像系统得到空间分辨率为5μm。实验 结果表明,基于石英球面弯曲晶体的X射线背光成像系统可以用于等离子体X射线诊断研究。     

X射线背光成像诊断的球面晶体分析器研究

在激光约束聚变和箍缩聚爆实验中,为了分析内爆 靶丸推进层的运动过程和评估激光辐射驱动的对称性和均匀性, 需要得到靶丸内爆单色X射线二维空间分辨信息。为了诊断内爆高温等离子体X射线二维空间 信息,利用晶体布喇格衍射 原理研制了新型的成像系统。系统的核心元件为球面晶体分析器,球面晶体为云母球面晶体 ,弯曲半径为143.3mm。在中 国工程物理研究院进行了单色X射线背光成像实验,磷屏成像板获得了清晰的Cr靶单色X射线 二维网格图像。通过对实验 所得背光图像分析,云母球面晶体成像系统得到的空间分辨率为86 μm。实验结果表明,云母球面晶体可以应用于等离子体X射线的背光成像诊断研究。     

球面晶体分析器在等离子体X射线诊断中的应用

为了诊断高温等离子体X射线,利用晶体布喇格衍射原理研制了新型的球面晶体分析器,α-石英为衍射晶体,球面的半径为250 mm.对球面晶体分析器分别进行静态X射线衍射实验和Z箍缩聚爆实验,富士磷屏(IP)成像板和感光胶片分别得到了清晰的Cu等离子体和Ti等离子体谱线.对实验所得谱线进行分析,石英球面晶体分析器光谱分辨力好于...     

球面弯晶实现X射线单能成像的研究

基于Bragg衍射原理,研制了一种对激光等离子体进行二维成像的球面晶体分析器。采用球面弯曲石英晶体作为分析器,X射线IP板作为成像器件。采用Cr靶X射线辐射金属网格（目标）,网格的网孔尺寸为200μm×200μm。通过球面弯晶对Cr靶Kα谱线的衍射,得到网格的二维单色衍射图像。实验结果表明,球面弯晶分析器具有较高的光谱...     

基于球面晶体背光成像系统的性能模拟研究

为了实现球面晶体背光成像、验证球面晶体背光成像系统性能,采用模拟软件SHADOW对该背光成像系统进行了模拟研究,并对实际成像过程中影响系统成像的探测器位置、背光源的大小等参量进行了模拟分析。结果表明,探测器位置的微小变化对成像系统的相对放大率影响较小;背光源越小,成像系统的空间分辨率越高。该成像系统具有很好的空间分辨率,系统性能稳定可靠。     

晶体位错处理对X射线衍射性能的影响

为提高晶体对波长为0.1~20 nm的X射线的衍射效率,通过特殊工艺对特定晶体表面进行位错处理。将云母、α-石英和LiF晶体劈成80 mm×10 mm的晶体薄片,其中LiF晶体厚度研磨到1 mm,其余三种晶体厚度为0.2 mm。将LiF晶体加热到400 ℃,然后用椭圆型折弯机进行多次弯曲,自然冷却降到室温,使晶格发生位错现象。在波长为0.154 nm的Cu靶X射线衍射仪上进行衍射试验,经晶体后利用成像板或X射线CCD获得衍射谱线,其中Mica球弯晶获得多级衍射谱线,经过表面处理的LiF晶体获取的X射线光子数比未处理的高2倍。结果表明晶体表面经过位错处理后提高了衍射效率,更适合X射线诊断研究。     

基于多锥晶体的多能点X射线光谱仪北大核心CSCD

为了克服传统弯曲晶体光谱仪存在检测的像差问题,基于衍射聚焦X射线特征能量谱范围、衍射光源位置、聚焦成像距离等关键的物理参数,设计了具有高光谱分辨力及宽光谱检测范围的多锥晶体X射线谱仪。从结构原理上讨论了该光谱仪的特点,研制完成了连续光滑的多锥表面X射线衍射聚焦弯曲晶体,通过单次X射线衍射聚焦诊断实验即能实现不同能量X射线无像差检测。对Ti的K_(α)与K_(β)射线光谱进行了多次衍射聚焦检测实验,获得了不同聚焦成像位置下的K_(α)与K_(β)特征谱线强度分布,并完成了光谱仪谱线聚焦能力与光谱分辨力分析。根据晶体对X射线聚焦程度与成像位置的关系,进行了不同聚焦成像位置处连续锥面光谱仪的聚焦性能分析,确定了最佳聚焦位置。实验结果表明:多锥晶体X射线光谱仪的聚焦能力得到显著提升,能谱检测范围可以覆盖4.51—5.14 keV,且在较大尺寸光源基础上仍能保证光谱分辨力达到600以上。     

铁电晶体铌酸钾锂的拉曼和FT—IR光谱

用提拉法生长了完整透明的铁电铌酸钾锂晶体 .利用X 射线荧光光谱法测量分析了晶体的组成 .采用X 射线测量了晶体的结构 .用结构完整、组分均匀 ,尺寸为 6× 6× 7(a×b×c)mm3 的晶体样品 ,测量了晶体的拉曼光谱和红外折射光谱 .与其它钨青铜类晶体的晶格振动光谱进行比较 ,铌酸钾锂晶体中对称弯曲振动模式v5在拉曼光谱中分裂为 3个拉曼峰 ,反对称伸缩振动模式v3 和反对称弯曲振动模式v4在红外反射光谱中所对应的峰被加宽 ,v4被轻微分裂 .这表明晶体中这位于C格位的Li离子对晶体中铌氧八面体的拉曼光谱和红外反射光谱有较大的影响     

基于级联卷积神经网络的疲劳检测

为了诊断热核聚变等离子体状态,研制了用于热 斑区等离子体诊断用的新型X射线光谱仪,能够同 时探测X射线光谱与聚爆靶图像信息。光谱检测功能由4块椭圆晶体分析器实现,材料分别 为α-石英(1010)、 α-石英(2023)、α-石英(1011)和Si(111),几乎能够覆盖2~20 keV能带范围内的X射线特 征光谱。光谱检测 结构为光源位于椭圆的一个焦点,其辐射光谱经过椭圆反射聚焦于椭圆另一焦点,由X射线 成像板(IP)接收。图 像检测功能由分幅相机匹配小孔阵列成像完成,理想状态能够得到20 幅不同时间的聚爆靶图像。在谱仪与 聚爆靶之间的调整台上设置厚为60μm的Be膜,以保护针孔与晶体避 免聚爆溅射碎片破坏。在中物院“神光- Ⅱ”升级装置上进行了打靶实验,获取了X射线光谱与聚爆靶图像信号。分析了光谱及图像 信息,并针对光谱 仪漏光问题改进了光谱仪结构,最后在神光-Ⅲ原型装置上进行了验证实验并获得比较理想 的图像信号,信噪比(SNR)数据达到15dB。     

激光等离子体X射线背光源诊断研究

为诊断激光驱动金属靶产生X射线背光源的性能,利用椭圆聚焦特性,研制了一种背光椭圆晶体谱仪。谱仪的色散分析元件为云母(002)晶体,椭圆弯晶的焦距为1350mm,离心率为0.9586。激光束以30°角斜入射背光薄靶,且与椭圆弯晶长轴方向垂直。背光椭圆弯晶谱仪的布拉格入射角为50°~67°,衍射探测角为100°~120°,探测的波长为0.14~0.16nm,采用X射线CCD相机接收信号。利用神光Ⅱ激光装置7#和8#激光器同时聚焦轰击10μm厚的Cu平面背光薄靶,CCD成功获取了Cu等离子体X射线的类氦和Kα谱线。经解谱发现谱线有明显基底,用最小二乘法差值去噪处理后,实测谱线分辨率(λ/Δλ)大于700。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.