X射线激发发射谱仪的研制

通过X射线管与光谱仪的组合,在对X射线管和光谱仪的选取、自动控制技术、数据采集和处理等多个环节进行系统论证的基础上,自行设计和研制了一台X射线激发发射谱仪.通过采用标准光源,对谱仪的波长和效率定标进行了重点研究,运用这一谱仪分别测量了BaF2和Cs Ⅰ(Tl)等闪烁晶体的X射线激发发射谱.实验结果表明:该谱仪具有光谱分辨高、性能稳定、操作简便、屏蔽良好等特点,可为闪烁材料的探索和开发提供一种十分有效的研究手段.     

波长色散X射线荧光光谱仪的内部校准

根据波长色散X射线荧光光谱仪检定规程制定了内部校准作业指导书,对PANalytical Axios 4.0型X射线荧光光谱仪的外观、精密度（RSD）、稳定性（RR）、探测器分辨率（流气正比计数器、闪烁计数器、封Xe正比计数器）和仪器的计数线性进行了性能测试和内部校准.     

石油及石油产品温度对能量色散X射线荧光光谱法测定硫含量结果影响的研究

考察样品温度对能量色散X射线荧光光谱法测定硫含量的影响;通过改变样品温度,观察测定结果的变化.结果表明:石油及石油产品的样品温度对X荧光光谱仪测试结果具有显著影响;多数含硫和高硫石油及其产品的样品温度对X荧光光谱仪测试结果的影响呈现正相关关系,低硫石油或低硫石油产品的样品温度对X荧光光谱仪测试结果的影响具有波动性.能量色散X射线荧光光谱法测定仪安装测试温度控制装置和改进样品温度自动校正曲线,对控制样品温度对X荧光光谱仪测试结果的准确度是十分必要的.     

X射线激发发射光谱仪的设计及实现

基于时间相关单光子计数原理的探测系统,设计并实现了一种新型的X射线激发发射光谱仪,以有效探测高能X射线激发闪烁体的发光强度(尤其是微弱的发光)及相关的余辉特性测量。通过对常见的Cs I(Tl)、LYSO(Ce)闪烁晶体和Tb3+激活硅酸盐闪烁玻璃等的测试结果表明,所研制的X射线激发发射光谱仪能很好地满足闪烁材料的研发需要。     

毛细管X光透镜三维共聚焦微束X射线荧光技术在岩矿样品分析中的应用

利用毛细管X光透镜搭建了三维共聚焦微束X射线荧光谱仪,处在激发道的多毛细管X射线会聚透镜和处在探测道的多毛细管X射线平行束透镜处于共聚焦状态,该共聚焦结构降低了X射线荧光光谱的背底,从而有利于降低的X射线荧光分析技术的探测极限。在上述共聚焦结构中,多毛细管X射线会聚透镜和多毛细管X射线平行束透镜的焦斑重合形成共聚焦微元,探测器只能探测到来自该共聚焦微元内的X射线荧光信号,当该共聚焦微元在样品移动时,就可利用该共聚焦技术原位无损得到样品内部的三维X射线荧光信息。该共聚焦技术使用的多毛细管X射线会聚透镜具有103量级的功率放大倍数,从而降低了该共聚焦技术对高功率X射线源的依赖程度,即利用低功率普通X射线源就可以设计毛细管X光透镜共聚焦X射线荧光技术。利用上述共聚焦微束X射线荧光谱仪对两种岩矿样品进行三维无损分析,在其中一种岩石中发现:Fe浓度大的区域Cu的浓度也大,这在一定程度上反映了岩矿自然生长的机理。实验结果证明:该共聚焦X射线荧光技术可以在不破坏样品情况下分析岩矿样品中元素成分组成和元素三维分布情况。该共聚焦三维微束X射线荧光技术在矿石勘察、玉器选材和鉴别、石质食用器皿、"赌石"和家用石质地板检测等领域具有潜在的应用。     

一种基于热释电效应的X射线荧光分析谱仪

利用热释电晶体实现了一个X射线激发源,并以此激发源和高能量分辨率的硅漂移探测器构建了一个X射线荧光分析谱仪。首先通过分析计算热释电晶体厚度和靶厚度对产生X射线的影响选定了激发源的设计参数;然后测量了激发源发射的X射线本底,其能量范围在1~27keV,包含有Cu和Ta的特征X射线,最大强度在每秒3 000个计数以上,对本底的测量同时显示出谱仪的探测器部分对Cu的8.05keV特征峰的分辨率达到210eV,具有很高的能量分辨率;最后使用该谱仪测试了Fe,Ti和Cr等三种单质样品和高钛玄武岩样品,测试结果表明该谱仪可以有效的分析出样品的元素成分。由于这种X射线荧光分析谱仪的各组成部分体积都很小,进一步便携化后非常适合于非破坏、现场和快速的元素分析场合。     

顺序式X射线荧光光谱仪调研综述

对新型波长色散单道顺序式X射线荧光光谱仪的性能作了比较，包括ARL 9400、PW2400／2404、SRS3400、RIX2100／3001和XRF1700等荧光光谱仪主要部件的技术指标、计算机硬件配置、定性和定量分析软件及无标样分析软件等。还比较了新型号仪器的特点和报价，征询了用户对仪器性能的评价和售后维修服务的印象。     

靶参数测量技术

利用微焦点X射线荧光谱仪进行了充氩靶丸X射线荧光激发测量实验。由于设备具有X射线聚焦功能，对样品局部辐照强度大，激发效率高，因此测量灵敏度及检测极限也大大提高，尽管由于塑料微球保气性能差，球内只有微量的氩气，仍然获得了氩气明显存在的证据，在测量得到的谱图中扣除本底后氩Ka射线峰非常明显。     

测定微束微区X射线探针分析仪焦平面的实验研究

微束微区X射线探针分析仪借助会聚X光透镜把X射线聚焦.针对仪器调试过程中需确定出口焦平面位置的难题.采用拟合曲线荧光分析方法方便快速地确定出口焦平面的位置.方法是用直径小于X焦斑直径的金属丝在不同测量平面上进行微动测量,因X光强度沿径向呈高斯分布,所以金属丝中元素荧光强度随位移也呈高斯分布.通过计算得出不同测量平面上同...     

氧化铝的X射线荧光光谱分析方法研讨

简要论述了氧化铝的X射线荧光光谱分析方法原理、样品处理、设备特点;在德国布鲁克公司的S4型X射线荧光光谱仪上用融片法分析氧化铝中的杂质含量,重点论述了用X射线荧光光谱法代替传统的化学分析方法的优势和不足.     

To the theory of three- and four-crystal X-ray spectrometers

The resolution was studied of the following types of X-ray spectrometers: Three-crystal spectrometer with all crystals in antiparallel position, three-crystal spectrometer with first two crystals in quasiparallel position (i.e. these crystals are set into the parallel position and then slightly misaligned) and four-crystal spectrometer with two pairs of quasiparallel crystals. The shape and width of smearing function were calculated and compared with the calculations for double-crystal spectrometer.     

石英消偏器紫外-真空紫外消偏特性研究

在Lyot消偏器的基础上 ,设计研制了由两块楔角相同的楔形石英晶体构成的石英消偏器 ,用于降低光谱仪偏振响应度。根据矩阵光学理论 ,数值模拟计算了紫外 真空紫外波段石英消偏器消偏特性随其中心厚度以及入射光偏振状态、光谱带宽等的变化规律。利用氟化锂偏振器作为起偏器和检偏器 ,在 1mSeya Namioka单色仪上实验研究了石英消偏器在紫外 真空紫外波段的消偏特性 ,经过石英消偏器后 ,出射光的偏振度小于 1% ,可满足石英消偏器用于光谱辐射测量的工作要求。     

2D Laue focusing of X-ray radiation by a double-crystal system

The theory of the dynamic 2D focusing of an X-ray wave upon its Laue diffraction by a system of two bent crystals is developed. The reflecting planes of the crystals are perpendicular to their surfaces. 2D focusing is shown to be highly sensitive to the bending radius of the crystals and to the difference in their thicknesses. The effect of astigmatism on 2D Laue focusing is described, and conditions for stigmatic focusing are found. One-dimensional focusing inside the crystals is discussed. The spectral characteristics of a double-crystal 2D-focusing spectrometer are considered.     

Curved crystal analysis using a triple-crystal X-ray spectrometer

A Bragg crystal spectrometer using cylindrically curved crystals is designed to focus a divergent X-ray beam. The spectral resolution and precision of focus is determined by the quality of the concavely curved crystal. The analysis of the quality of the crystal was done using a triplecrystal X-ray spectrometer, comparing parallel and antiparallel X-ray scans of the third curved crystal, determining flaws resulting from the bend. Topics discussed include the derivation of the crystal's quality, conditions of alignment for the Bragg reflection, and X-ray beam width contributions to the FWHM. Organic and inorganic crystals with varying values of Bragg angles are used.     

Features of the spectral intensity of scattered light near the phase transition point in quartz crystals

The isofrequency dependences of inelastic light scattering in quartz crystals near the phase transition point are calculated taking into account both spatially inhomogeneous fluctuations of the order parameter and the finite spectral width of the spectrometer slit. It was found that the theory is in satisfactory agreement with the experimental data on dynamic opalescence observed in quartz crystals during phase transformations.     

Acoustic phonon spectroscopy

An introduction is given to an acoustic phonon spectrometer, which is based on optical modulation techniques to detect magnetic circular dichroism. The spectrometer is capable of detecting deviations from a thermal background at a few degrees Kelvin of 1 part in 10⁴ within a 4 mK (80 MHz) bandwidth over the phonon energy range of 0.3 to 16K. Because the strongest phonon interactions in dielectric crystals at a few degrees Kelvin occur on the surfaces, many of the applications have been concerned with surface problems.     

Polarization and the luminescence spectrum of crystalline sodium uranyl acetate

A photoelectric spectrometer with a linear dispersion of 5.2 Å/mm at was used to study the luminescence spectrum of sodium uranyl acetate crystals at 77°K. The resulting spectrum is interpreted on the basis of the crystal structure. The nature of the optical activity of the crystals is discussed.In conclusion, the authors express their sincere thanks to Academician of the Belorussian SSR A. N. Sevchenko for his interest in and attention to the present study.     

Picosecond absorption spectroscopy and its application to the study of nucleic acid components

A high performance picosecond absorption spectrometer adapted for induced absorption measurements in the UV region is described. An application of the spectrometer to the study of nucleic acids (NA) components is presented. Experimental results are given of induced absorption measurements in water solutions of NA components and in single crystals of NA bases.