弯晶X射线光学

近年来,人们付出很大精力研制新的具有独特性能的同步辐射装置和自由电子激光器,而飞秒激光等离子源可提供具有高峰值亮度的超短X射线脉冲,用来作为波荡器辐射的补充X射线源。此外,所有最新型的X射线源的诊断和应用也都需要专用X射线光学元件或仪器。X射线光谱测量是激光聚变应用中最重要的等离子诊断方法之一,该方法根据实验目的,可获得单色X射线图像或与空间或时间分辨相组合的高分辨率图像。已经研制出拥有多达10个环状弯晶的高精单色成像仪,用以研究激光聚变实验中的内爆过程并通过获得的数据对等离子体参数的时间分辨图做出评估。大功率飞秒激光器可提供实用的相对价格不高的大功率X射线脉冲源,但需要有发光效率,能量分布,以及热电子传输方面的信息来实现理想K层辐射线或者连续X射线输出的最大化,以便得到相当于同步辐射输出的峰值亮度。把这些新的射线源与弯晶光学元件相组合,可完成亚皮秒时间量级的衍射实验。激光泵浦的X射线探针实验已经展示了若干晶体在250 fs内的结构变化。作者所在研究所使用光线追踪和布拉格反射方法设计了1D或2D或1D与2D结合的弯晶X射线光学仪器。在仪器制备过程中,非常注重晶体完整,反射选择的优化,弯曲精确,以及成像和反射特性的测量,还使用X射线形貌相机和衍射仪对分析器晶体的相关特性做了测试。     

能量色散X射线荧光光谱仪的现状

能量色散X射线荧光光谱分析以其快速、对试样无损、可以同时测定多种元素等优点,在许多领域中发挥巨大的作用。本文介绍能量色散X射线荧光光谱仪的原理和构造,并就目前仪器的研究现状和应用现状做介绍,指出X射线荧光分析技术的良好前景及进一步研究该仪器的必要性。     

同位素源X射线荧光分析及其在无损检测上的应用

一、简介 1965年英国制成第一台手提式同位素源X射线荧光分析仪,使X射线荧光分析走出实验室进入现场使用。以后各工业国家相继发展这种仪器,广泛用于各领域。 X射线荧光分析仪很适用于精度高、无损伤和快速的元素分析,因为它可激发与检测元素周期表10以上的所有元素的特征X射线谱。     

小型多道波散型X射线荧光光谱仪的研制

介绍一种新研制成功的小型多道波散裂X射线荧光光谱仪，这种仪器采用小功率X光管作激发源，采用对数螺线弯晶进行分光，整机操作由微处理器和PC机控制，具有仪器结构紧凑，环境适应性强，性能价格比好等特点，适用于建材，化工，冶金等行业的生产控制分析。     

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。     

流气正比探测器窗口的研制

流气正比探测器用在大型X射线荧光光谱仪上,主要用来测量软X射线。探测器的窗口极薄,容易损坏。进口探测器窗口价格较贵,属于易损件。通过解剖进口流气正比探测器窗口,自制了用于荷兰飞利浦公司PW1400仪器的探测器窗口,并经多年使用,效果良好,可以代替进口。     

国产X射线粉末衍射仪的现状

对国产X射线粉末衍射仪的现状进行了评述。近年国产粉末衍射仪较之以前已有很大的进步。虽与进口仪器仍有差距,但国产仪器已可满足粉末结构分析和物相分析的基本需要。现在无论应用国产衍射仪还是进口知名衍射仪,在相近的实验条件下,得到的X射线粉末衍射图数据的质量是同一水平的。     

球面弯曲晶体在X射线背光成像的应用

基于X射线布喇格衍射理论,研制了球面弯曲晶体分析器,用于研究和诊断惯性约束聚变的聚爆靶等离子体的形状、分布及稳定性.分析器的核心器件是石英球面弯晶,弯曲晶体半径为143.3 mm.首次利用石英球面弯曲晶体进行了单色X射线背光成像实验.采用接收面积为40 mm×30 mm的磷屏成像板作为接收装置,得到了清晰的铬靶单色X射...     

X射线衍射仪的微机数据处理系统

本文介绍的X射线衍射仪微机数据处理系统,用先进的微机技术对我国早年进口的日本理学3015X射线衍射仪进行改造。在仪器原有的测量控制下,通过简单的接口,将衍射仪及附机X荧光分析仪的测量数据准确地采集到微型计算机中,由微机来完成X衍射及X荧光分析中的各种繁琐而又重复的数据处理任务,将仪器的分析性能提高到一个新的水平。本文着重介绍微机与3015X衍射仪的硬件联接和测量数据的采集。     

X射线辐射测量

在过去的几年里,人们使用同步辐射技术在X射线波段实现了基于辐射源和基于探测器的辐射测量,电子储存环被用作主辐射源标准,而低温辐射计(ESR)被用作主探测器标准。因为低温辐射计需要强的单色辐射,所以,这种方式也必须使用同步辐射。文中对能量色散探测器和硅光电二极管的探测效率和响应度做了校准,其相对不确定度约1%,所得结果与模型计算值做了比较。     

X射线荧光光谱分析的新进展

本文简要介绍伦琴发现X射线100年后(1895～)X射线荧光光谱分析的新进展。随着各种新型探测器Si-PIN、SDD、超导隧道结、微热量计,各种新型激发源从微型X射线管到同步辐射无电子X射线激光及各种新型光学器件(Capillary)的出现,在世纪之交这一阶段X射线荧光光谱分析技术空前地扩展了其应用领域和应用能力。微区分析已可探测到原子数量级,X射线全息术和X射线断层术已可识别单晶中的原子分布和单个生物细胞的图像。预计在新的世纪里X射线荧光光谱技术必将又更加飞速的发展。     

PW1410X射线荧光光谱仪的改造与应用

对荷兰飞利浦公司生产的ＰＷ１４１０Ｘ射线荧光光谱仪进行了改进，研制了专用的定性、定量分析接口板，将它们与ＩＢＭ－ＰＣ计算机样联；编制了通用的Ｘ射线荧光光谱定性和定量分析软件，使原先非自动化的仪器改造成可用ＩＢＭ－ＰＣ机进行分析数据自动化处理的更新仪器。     

Synchrotron nanoscopy imaging study of scalp hair in breast cancer patients and healthy individuals: Difference in medulla loss and cortical membrane enhancements

Nanoscopic synchrotron X‐ray imaging was performed on scalp hair samples of patients with breast cancer and healthy individuals to investigate any structural differences as diagnostic tool. Hair strands were divided into 2‐3 segments along the strands from root to tip, followed by imaging either in projection or in CT scanning with a monochromatic 6.78‐keV X‐ray using zone‐plate optics with a resolving power of 60 nm. All the examined cancer hairs exhibited medulla loss with cancer stage‐dependent pattern; complete loss, discontinuous or trace along the strands. In contrast, medullas were well retained without complete loss in the healthy hair. In the CT‐scanned axial images, the cortical spindle compartments had no contrast in the healthy hair, but appeared hypointense in contrast to the surrounding hyperintense cortical membrane complex in the cancer hair. In conclusion, observation of medulla loss and cortical membrane enhancements in the hair strands of breast cancer patients demonstrated structural variations in the cancer hair, providing a new platform for further synchrotron X‐ray imaging study of screening breast cancer patients. Microsc. Res. Tech. 79:23–30, 2016. © 2015 Wiley Periodicals, Inc.     

面向SMT的微焦X射线精密检测技术

面向SMT的的微焦X射线精密检测技术是电子组装工艺缺陷检测的关键技术。着重论述了2．5D微焦X射线设备的构成与原理以及国内外微焦2．5DX射线检测设备的现状．归纳了该类设备的关键技术．并展望了面向SMT的X射线检测技术的发展趋势。     

C/Al软X射线多层膜反射镜的制备与测量

在λ＝ ２８．５ｎｍ 波长处,我们选择了一种新的多层膜材料对Ｃ／Ａｌ。正入射Ｃ／Ａｌ多层膜在１５．０ｎｍ 附近有很低的二级衍射峰。磁控溅射法制备的Ｃ／Ａｌ多层膜样品,用Ｘ射线小角衍射法对其结构进行了测试,并测得Ｃ／Ａｌ软Ｘ射线多层膜的正入射反射率２２％ ±４％ 。     

Zinc as an essential trace element in the acceleration of matrix vesicles-mediated mineral deposition

BACKGROUND: Zinc (Zn) has a potent stimulatory effect on osteoblastic bone formation and an inhibitory effect on osteoclastic bone resorption. PURPOSE: The effect of Zn on the function of matrix vesicles (MVs) remains controversial. The purpose of this study was to investigate the effect of Zn on alkaline phosphatase (ALP) activity of osteoblasts and in the initial biological MVs‐mediated mineral deposition. STUDY DESIGN: Osteoblasts were treated with varying concentrations of Zn dissolved in culture medium. After three, five, and seven days of culture, ALP activity was assayed. For the detection of a low level of calcium concentration in MVs, X‐ray fluorescence (XRF) analyses were applied. The effect of Zn for the transformation of calcium phosphate was analyzed using a scanning electron microscope fitted with an energy dispersive X‐ray microanalysis (EDX) system. RESULTS: The ALP activity of osteoblasts in culture medium supplemented with 1 × 10^?5M of Zn was significantly increased at both five and seven days. XRF data demonstrated higher levels of calcium concentration over time in the Zn‐supplemented group. EDX data showed that mineral deposits beginning on day 3 were transformed from whitlockite to calcium phosphate near hydroxyapatite, and that Zn accelerated this transformation. CONCLUSIONS: The proper concentration of Zn increased the ALP activity of osteoblasts after five and seven days of incubation. The present XRF and EDX data suggest that the increase of mineral deposition with Zn exposure for one to five days might be mediated by the activation of ALP and calcium‐binding proteins. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.     

X射线干涉仪中单晶硅微动工作台的研制

目前国际上Ｘ射线干涉仪所采用的微动工作台均采用对称式柔性铰链结构,其缺点是侧 滑角大,严重影响干涉信号的对比度,很容易产生干涉条纹的记数误差。为此提出了非对称结构微动工作台的设计思想,并引入有限元方法进行了结构参数优化,研制了整体式Ｘ射线干涉仪。理论分析和实验表明：利用非对称结构研制的Ｘ射线干涉仪,分析器的侧滑角显著下降,干涉信号的对比度大大提高,更适合Ｘ射线干涉纳米测量的要求。     

Imaging connected porosity of crystalline rock by contrast agent‐aided X‐ray microtomography and scanning electron microscopy

We set out to study connected porosity of crystalline rock using X‐ray microtomography and scanning electron microscopy with energy dispersive X‐ray spectroscopy (SEM‐EDS) with caesium chloride as a contrast agent. Caesium is an important radionuclide regarding the final deposition of nuclear waste and also forms dense phases that can be readily distinguished by X‐ray microtomography and SEM‐EDS. Six samples from two sites, Olkiluoto (Finland) and Grimsel (Switzerland), where transport properties of crystalline rock are being studied in situ, were investigated using X‐ray microtomography and SEM‐EDS. The samples were imaged with X‐ray microtomography, immersed in a saturated caesium chloride (CsCl) solution for 141, 249 and 365 days and imaged again with X‐ray microtomography. CsCl inside the samples was successfully detected with X‐ray microtomography and it had completely penetrated all six samples. SEM‐EDS elemental mapping was used to study the location of caesium in the samples in detail with quantitative mineral information. Precipitated CsCl was found in the connected pore space in Olkiluoto veined gneiss and in lesser amounts in Grimsel granodiorite. Only a very small amount of precipitated CsCl was observed in the Grimsel granodiorite samples. In Olkiluoto veined gneiss caesium was found in pinitised areas of cordierite grains. In the pinitised areas caesium was found in notable excess compared to chloride, possibly due to the combination of small pore size and negatively charged surfaces. In addition, elevated concentrations of caesium were found in kaolinite and sphalerite phases. The findings concerning the location of CsCl were congruent with X‐ray microtomography.     

X射线光学系统的光线追迹

阐述了硬X射线光学系统的光线追迹过程,处理的光学系统可包含任意数目的镜子、晶体及光阑,镜子或晶体的面形可以各种各样,它们的排列方式可为共主面或相互正交.根据劳厄衍射方程的矢量形式计算光线经对称或非对称晶体衍射后的方向.我们应用C语言编写了光线追迹程序,它不仅可以得到光路中任意位置像面上光线的点列图分布,而用可以计算晶体的摇摆曲线.最后作为例子,我们用此程序计算了一条同步辐射X射线光束线系统的成像.     

Synchrotron radiation X‐ray micro‐fluorescence: Protocol to study mesenchymal stem cells

The micro‐X‐ray fluorescence by synchrotron radiation (μ‐XRF) is a method to determine the composition of tissues without destroying the samples. However, this technique has never been used for the analysis of mesenchymal stem cells (MSC). This study compared different protocols for fixing, storing, preserving, and establishing the correct numbers of dental derived MSC submitted to μ‐XRF analysis. Stem cells were obtained from human dental tissue. After cell expansion, and MACS isolation, the samples were fixed and the following quantities of cells 1 × 10⁴ to 1 × 10⁷ were divided in two groups: G1: fixed in 4% paraformaldehyde diluted in phosphate‐buffered saline solution, and G2: fixed in 4% paraformaldehyde diluted in MilliQ water. The G1 cells showed precipitation of chemical components from the solution resulting in the formation of salt crystals while G2 cells were clear and almost transparent in the sample holder. With regards to cells concentration, the best results occurred when four droplets of 1 × 10⁷ cells were analyzed. This work shows that to identify and study the distribution of trace elements in MSC by μ‐XRF, the best protocol is fixation in 4% paraformaldehyde diluted with MilliQ water at 4°C and a concentration of four incremental droplets of 1 × 10⁷ cells. Microsc. Res. Tech. 79:149–154, 2016. © 2016 Wiley Periodicals, Inc.