软X射线掠入射望远镜的成像质量评价

为了评价软X射线掠入射望远镜的成像质量,提出了一种利用ZEMAX和MATLAB相结合的像质评价方法。根据这种方法编写的像质评价程序不仅考虑了孔径衍射、几何像差和装调误差等因素对成像质量的影响,而且加入了望远镜面形误差和X射线散射效应的影响。利用勒让德-傅里叶多项式和用户自定义表面,在ZEMAX中建立带有面形误差的筒状反射镜表面模型,实现对真实面形的掠入射反射镜的仿真;根据Harvey-Shack散射理论建立了ZEMAX中的BSDF散射模型,实现对X射线散射的仿真。搭建X射线有限远成像实验装置,对像质评价程序进行了验证。实验结果和仿真结果对比表明:实验光斑和仿真光斑的光强分布基本一致,以实验结果为基准,仿真光斑的半高全宽横向和纵向的相对误差分别为14.7%和11.3%。说明像质评价程序的仿真结果基本符合真实情况,对掠入射光学系统的设计和加工具有一定的指导意义。     

Wolter-I型X射线天文望远镜的光学设计

针对国内硬X射线天文观测的需求,研究了1~30 keV能段圆锥嵌套Wolter-I型X射线天文望远镜的光学设计,推导了嵌套层之间的结构递推关系,给出了合理的望远镜初始结构。在最内层和最外层之间,设计了6组W/B4C宽带非周期多层膜,模拟得到系统的有效集光面积和分辨力。理论有效集光面积达到127 cm2(在2 keV处)和71 cm2(在30 keV处),系统角分辨力约10″。系统实际成像质量还受到公差的影响,引起像质下降的公差主要有辐条位置公差、镜面位置公差和镜面面形公差。目前演示实验方便改善的公差是辐条位置公差,给出了此公差的计算方法并对系统进行光线追迹,得到了成像点列图和分辨力改变情况。辐条位置公差从±15 μm缩小到±3 μm后,系统分辨力由1′提高到13″。     

Wolter-Ⅰ型X射线天文望远镜的光学设计

针对国内硬X射线天文观测的需求,研究了1～30keV能段圆锥嵌套Wolter-Ⅰ型X射线天文望远镜的光学设计,推导了嵌套层之间的结构递推关系,给出了合理的望远镜初始结构。在最内层和最外层之间,设计了6组W/B4C宽带非周期多层膜,模拟得到系统的有效集光面积和分辨力。理论有效集光面积达到127cm2(在2keV处)和71cm2(在30keV处),系统角分辨力约10″。系统实际成像质量还受到公差的影响,引起像质下降的公差主要有辐条位置公差、镜面位置公差和镜面面形公差。目前演示实验方便改善的公差是辐条位置公差,给出了此公差的计算方法并对系统进行光线追迹,得到了成像点列图和分辨力改变情况。辐条位置公差从±15μm缩小到±3μm后,系统分辨力由1′提高到13″。     

18.2nm Schwarzschild显微物镜用多层膜带宽匹配问题分析

软X射线多层膜的进展使正入射高分辨率成像系统从红外、可见和紫外扩展到软X射线波段.由于软X射线多层膜的反射率还不能像其它波段反射镜反射率那样高,因此由两块同心球面反射镜组成的Schwarzschild物镜在软X射线波段得到了广泛的应用.本文从多层膜带宽匹配条件、Schwarzschild显微物镜的几何尺寸和多层膜镀制设备的性能出发,研究了实现Schwarzschild显微物镜带宽匹配条件的镀膜过程,为实际制备Schwarzschild显微物镜用多层膜提供理论指导.     

18.2nm Schwarzschild显微物镜用多层膜带宽匹配问题分析

软X射线多层膜的进展使正入射高分辨率成像系统从红外、可见和紫外扩展到软X射线波段。由于软X射线多层膜的反射率还不能像其它波段反射镜反射率那样高,因此由两块同心球面反射镜组成的Schwarzschild物镜在软X射线波段得到了广泛的应用。本文从多层膜带宽匹配条件、Schwarzschild显微物镜的几何尺寸和多层膜镀制设备的性能出发,研究了实现Schwarzschild显微物镜带宽匹配条件的镀膜过程,为实际制备Schwarzschild显微物镜用多层膜提供理论指导。     

全反射式无焦ZH系统的装调

介绍了一种新颖的共轴全反射式无焦光学系统—ZH系统的装调技术.该系统由两块相对放置的抛物面反射镜和一块45°放置的双面反射镜组成,其两抛物面反射镜可分别从两端安装,从而使双向平面反射镜易于装配.对ZH系统进行了误差分析和装调分析,讨论了元件位置失调带来的系统像差的变化,给出了ZH系统的误差分析结果.由于光线经过ZH系统...     

大型X射线光学仪器:单层镜和多层镜的制造与表征

150~500 mm长度的各种X射线光学元件可用于光束导引,光束调整,以及单色化。本文介绍了两种不同的大型X射线反射镜。第一种为单层反射镜,这种反射镜以2°掠入射角在软X射线区(50~200 eV)起全反射镜作用,可用于自由电子激光器,如德国汉堡的FLASH。第二种是多层镜,由于它的布喇格反射特性,适于作为反射镜以0.4~1°的入射角用于硬X射线区(20~50 keV),如层析光束线的同步辐射存储环中。两种反射镜都用最新物理汽相淀积法制备,并用磁控溅射来实现X射线光学应用所需要的优良光学品质。这一淀积工艺使不同批次的镀膜稳定性良好,有利于实际反射镜在优质衬底上的最后淀积。单层镜和多层镜在它们的相关能量范围内都有很高的反射率,表面粗糙度也很低,且在整个光学波长区这些特性表现均匀。文中所叙相关研究都是借助X射线反射计量(XRR)法,透射电子显微镜(TEM)、光学轮廓仪(OP),以及原子力显微镜(AFM)完成的。     

X射线安检设备智能控制与诊断系统设计

典型的X射线安检设备主要由X射线发生器、X射线线性阵列探测器、滚筒电机及传动装置、装有图像采集卡的PC及光触发传感器等组成，要实现各部分协调、高效的工作需设计一套完善的控制系统。依据X射线安检机各部分的工作原理及控制要求，制定了系统的控制方案，该控制系统方案已应用到沈阳地泰检测设备有限公司DEX9080B型X射线安检机上，经过2年多的运行，证明该系统运行稳定、响应速度快，具有良好的抗干扰性和实用价值。     

平行式Schmidt型龙虾眼X射线光学系统研究

龙虾眼X射线系统是实现大视场X射线成像的有效手段。现研制了由多组平行玻璃平板构成的Schmidt型X射线龙虾眼光学系统,开展了X射线聚焦和成像的演示实验。基于掠入射反射理论,以210μm厚的超光滑平板玻璃作为光学元件,通过堆叠的方式制作了放大倍数为1的演示系统。用8keV的X射线光源对系统进行了聚焦和实验,直径280μm的光源聚焦半高宽约为320μm,与理论模拟结果基本一致。利用X射线背光照明,得到2mm×2mm大小图样的成像。实验结果表明,该龙虾眼光学系统可以在几毫米视场下达到百微米分辨。     

长春光机所软X射线-极紫外波段光学研究

综述了我所软X射线-极紫外波段关键技术的研究进展。描述了软X射线-极紫外波段光源技术,研制了工作波段为6~22 nm的微流靶激光等离子体光源;介绍了光子计数成像探测器技术,研制出了有效直径为25 mm,等效像元分辨率为0.3 mm的极紫外波段探测器;开展了超光滑表面加工、检测技术的研究,研制了超光滑表面抛光机,加工出高面形精度的超光滑表面,面形精度为6 nm(RMS值),表面粗糙度达0.6 nm(RMS值);进行了软X射线-极紫外波段多层膜技术的研究,研制出13 nm处反射率为60%的多层膜反射镜,150 mm口径反射镜的反射率均匀性优于±2.5%;最后,讨论了软X射线-极紫外波段测量技术研究,研制出该波段反射率计,其测量范围为5~50 nm,光谱分辨率好于0.2 nm,测量重复性好于±1%。在上述关键技术研究基础上,研制出了极紫外波段成像仪和空间极紫外波段太阳望远镜,这些仪器在我国空间科学研究项目中发挥了作用。     

Error analysis of the parameters for non-coaxial grazing X-ray microscope

A non-coaxial grazing X-ray microscope, consisting of four spherical mirrors, is designed for diagnosis of inertial confinement fusion (ICF). The aberrations and imaging quality of the microscope are analyzed. To acquire excellent imaging quality, suitable tolerances for manufacturing and assembling the microscope are necessary. This paper researches the changes of Gauss parameters and aberrations due to component and subsystem parameters (such as the radius of the mirror, angle between mirrors, grazing angle, object distance, etc.). Here, spot diagrams and modulation transfer function (MTF) are first adopted to quantitatively evaluate the imaging quality of the microscope. Suitable manufacturing tolerances of components and assembly tolerances of the system are established on the basis of the discussion and analysis. A set of non-coaxial grazing X-ray microscopes is manufactured based on the tolerances. In site tests of ICF, the images with high resolution are obtained by the microscope. __________ Translated from Optics and Precision Engineering, 2006, 14(1): 34–42 [译自: 光学精密工程]     

Manufacturing and testing of X-ray imaging components with high precision

1Introduction X rayimagingtechnologyhasbeenoneof themostimportantresearchcontentssince RoentgendiscoveredX rayin1895.Initially,X raywasusedtostudytheinternalstructureof substancesbycontactradiography.Thespeci menisplacedincontactwithaphotographicfilm duringtheX rayexposure.Theimageofthe specimenisdisplayedafterdeveloping.The methodhasbeenuseduntilnow,anditiswidely appliedinmedicaltreatmentandinnerflawsde tectionofindustrialmaterials.Sincetherefractiveindicesofmaterialsin X rayrangearelowert…     

Optimization of a Wolter type I mirror for a soft X-ray microscope

The demand for an X-ray microscope has received much attention because of the desire to study living cells under high resolution. A Wolter type I mirror used for soft X-ray microscope optics has a number of advantages. Although much progress has been made, it is still not easy to fabricate this mirror and satisfy the surface roughness and figure error requirements. From the mirror fabrication point of view, it is necessary to see the mirror design and the tolerance budget, especially with respect to the surface roughness and the figure errors. This paper deals with the design and optimization of a Wolter type I microscope mirror. The optimization was carried out by choosing an optimum central grazing incidence angle for which a merit function had the maximum value. The image quality of the mirror was also examined. A smaller diameter gave better image quality because of the Abbe sine condition. Finally, the figure errors for the axial and the radial directions were simulated by sinusoidal deformation waves, and the figure tolerance was obtained.     

大口径传输反射镜的研究进展

针对我国惯性约束聚变装置(ICF)对高性能传输反射镜元件的性能要求,探索了大口径传输反射镜制备涉及的关键技术与工艺。深入开展了K9玻璃坯片研制、光学冷加工、传输反射镜镀膜和激光预处理等方面的研究工作。提出了400mm口径K9反射类坯片精密退火工艺,形成了高精度平面加工技术路线;制备了低缺陷薄膜,并且建立了大口径光学元件预处理装置。最后,综述了大口径高性能传输反射镜研制方面的主要成果。研制的400mm口径传输反射镜在1053nm处以45°入射时,其表面粗糙度优于99.8%,面形PV值小于λ/3(λ=1 053nm),损伤阈值大于30J/cm2(5ns)。基于提出的技术研制的大口径传输反射镜已成功应用于我国神光系列高功率激光装置,有力支撑了我国大型激光装置的稳定运行。     

Computer-aided geometrical dimensioning and tolerancing for process-operation planning and quality control

This paper describes an extension of a model which determines an optimum set of dimensions and tolerances for machining processes at minimum manufacturing cost. This optimisation minimizes the cost of scrap, which is a function of manufacturing tolerances, as the objective function. Requirements of design sizes, geometrical tolerances (including both form and position) and machining allowances are expressed mathematically as constraints for the optimisation. A computerised trace method has been extended to determine the relationships between geometrical tolerances and associated relevant manufacturing dimensions and tolerances. In addition to the manufacturing cost, the model takes into account manufacturing sequence, distribution of manufacturing dimensions, process capabilities, tolerances, design sizes, geometrical tolerances, machining allowances and optimum scrap level. The resulting computerized interactive system can be used not only in process planning, but also in quality control.     

Development of optics for x-ray phase-contrast imaging of high energy density plasmas

Phase-contrast or refraction-enhanced x-ray radiography can be useful for the diagnostic of low-Z high energy density plasmas, such as imploding inertial confinement fusion (ICF) pellets, due to its sensitivity to density gradients. To separate and quantify the absorption and refraction contributions to x-ray images, methods based on microperiodic optics, such as shearing interferometry, can be used. To enable applying such methods with the energetic x rays needed for ICF radiography, we investigate a new type of optics consisting of grazing incidence microperiodic mirrors. Using such mirrors, efficient phase-contrast imaging systems could be built for energies up to ～100?keV. In addition, a simple lithographic method is proposed for the production of the microperiodic x-ray mirrors based on the difference in the total reflection between a low-Z substrate and a high-Z film. Prototype mirrors fabricated with this method show promising characteristics in laboratory tests.     

软X射线掠入射金属光栅闪耀特性的校正傅里叶展开微分法分析

在有限电导率光栅的微分理论中引入校正傅里叶展开方法,改善了计算收敛性。运用改进后的微分理论对软X射线波段掠入射金属光栅的闪耀特性做了数值分析,通过详细考察三角槽形、正弦槽形和矩形镀金光栅的软X射线-1级衍射效率对光栅结构参数和入射光状态参数的响应程度,给出了一种在使用和制作工艺上都能够接受的光栅技术指标。结果表明,作为闪耀波长为10.33 nm的软X射线波段掠入射镀金光栅,采用81°入射的刻线密度为1 200 l/mm,倾斜角为2°,顶角大于120°的三角槽形光栅较为合适,其效率可达到50%以上。同时,得到了一些优化软X射线波段掠入射金属光栅设计的新结论。     

Computer Controlled Polishing of the Off-axis Aspheric Mirrors

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Incoherent imaging with the soft X-ray microscope

The imaging characteristics for X-ray wavelengths in the "water window" under incoherent imaging conditions (large detector aperture) are examined for the King's College London scanning transmission X-ray microscope with zone-plate objective installed at the Daresbury (UK) synchrotron. The principal consideration was to express image theory, incorporating wave aberrations and apodised zone plates, and to apply the theory to experimental data. Comparisons are made, showing reasonable agreement, for a range of defocus values and two wavelengths. Due to problems in fabrication it was necessary to determine the effective, or operational, zone-plate parameters (radius of outermost active zone rN, width of outermost active zone drN); this was accomplished by through-focus series. Calculated point spread functions were used to deblurr images, in through-focus series of two-dimensional scanned X-ray images of specimen holes and test grating patterns. Significant contrast enhancement is achieved after deconvolution with a best point-to-point resolution of about 35 nm.