WDXRF光谱仪与EDXRF光谱仪之异同

介绍了波长色散X射线荧光光谱仪和能量色散X射线荧光光谱仪的基本结构和工作原理,并对此两种光谱仪的结构、激发原理、分光和探测原理及其主要性能指标进行了比较和综合评述。     

X射线荧光光谱仪的现状

综述了波长色散X射线荧光光谱仪和能量色散X射线荧光光谱仪的现状和发展趋势,及其X射线荧光光谱仪的拓展,介绍了部分具有代表性的X射线荧光光谱仪的主要性能.     

X射线荧光光谱仪的发展及应用

X射线荧光光谱仪是进行组分和结构分析的有力工具,简述了X射线荧光光谱仪的基本原理并对其进行了分类,重点介绍了其在光源、探测器等硬件发面的发展,扼要介绍了其应用,最后对其发展趋势作了简要展望。     

便携式微束X射线荧光谱仪的研发

研制了便携式微束X射线荧光谱仪,并对其硬件、软件和性能等特征进行了分析。该谱仪应用激光位移传感器实时检测样品测量点到透镜出端之间的距离并自动调节该距离的方法,来解决考古样品表面不平整或弧度而造成的照射样品X射线束斑变化的问题,从而保证X射线照射光斑大小不变。为验证谱仪的可靠性,采用该谱仪测量了表面高度差接近5 mm的古陶瓷样品微区的釉彩层元素的分布。分析结果表明,激光位移传感器能有效减少由于样品表面不平整或弧度带来的测量误差。此外,使用本谱仪分析了5角硬币表面4 mm×4 mm的区域,经过数据处理后得到Cu、Sn等元素的分布及其合金相的分布,表明该谱仪不仅可进行微区能量色散X射线荧光分析（μ-EDXRF）,同时还可进行微区能量色散X射线衍射分析（μ-EDXRD）。     

一种新型的X射线荧光谱仪

【美国《工程与采矿杂志》19了9年第10期报道】菲利浦工业公司展出了一种新的X射线荧光谱仪,型号为Pw1600/10,用微处理机控制。这是一种快速的     

能量色散X射线荧光光谱仪现状及其发展趋势

能量色散X射线荧光光谱仪被广泛用于许多部门和领域,已成为理化检测、野外现场分析和过程控制分析等的重要工具.文中介绍了现代能量色散X射线荧光光谱仪主要性能指标,综述了能量色散X射线荧光光谱仪的硬件和软件研制现状,简述了多种新型的能量色散型X射线荧光光谱仪,并对其发展趋势与前景进行了展望.     

用同步辐射共聚焦X射线方法研究古代彩绘样品的层状结构

同步辐射共聚焦X射线方法是一种元素成分及其化学结构的三维无损分析方法,在地质、考古、环境、生物及材料等领域具有重要的应用。在上海光源的硬X射线微聚焦光束线站(BL15U)建立共聚焦X射线实验方法,并用于故宫彩绘样品的制作工艺及层状结构分析。基于BL15U的K-B聚焦系统,在能散探测器前采用会聚毛细管半透镜实现与K-B聚焦镜焦点的共聚焦状态,深度分辨在8.04 ke V(Cu-Kα)为31.5μm,可以开展共聚焦微束X射线荧光(Micro-X-ray Fluorescence,Micro-XRF)和共聚焦微束X射线吸收精细结构(Micro-X-ray Absorption Fine Structure,Micro-XAFS)实验研究。对故宫斗彩陶瓷和彩绘样品进行了元素及其化学态的深度分布分析,获得了斗彩陶瓷特有的三层釉结构以及彩绘样品内部颜料的化学信息。实验结果表明,该系统具有较高的空间分辨和探测灵敏度,是文物样品三维无损分析的有力工具。     

高分辨Si(Li)探测器系统

一、引言Si(Li)探测器系统主要包括Si(Li)探测器、低噪声前置放大器、低温装置等。Si(Li)探测器系统配上测试系统即组成Si(Li)X射线荧光谱仪,广泛应用于科学研究和工矿企业。     

用于ICF的非晶SiC微球制备及微观结构研究

以四甲基硅烷、反式二丁烯和氢气为工作气源,采用化学气相沉积-高温热解法成功制备了壁厚约21μm的非晶SiC微球。利用能量色散X射线光谱仪、X射线光电子能谱仪、X射线衍射仪、Raman光谱仪、扫描电子显微镜、白光干涉仪和X射线照相机对SiC微球的化学成分、结晶状态、表面形貌与粗糙度以及密度与球形度等进行了测量和分析。结果表明:在无氧环境下,通过450~900℃的高温热解及致密化可将在聚α甲基苯乙烯芯轴上沉积的掺硅碳氢聚合物涂层转变成致密的SiC微球。SiC微球呈非晶态,其C/Si原子比约为1.3,主要含有C—Si键和C=C键,微观结构呈无规则状且颗粒分布均匀,密度、球形度和壁厚均匀性分别为2.62 g/cm~3、99.8%和96.8%。     

标准动态

IEC 62495 ed1·0核仪器——利用一个微型X射线管的便携式X射线荧光分析装置(发布日期:2011年4月7日)IEC62495:2011(E)适用于使用一个微型X射线管作为工业应用电离辐射源的便携式手动X射线荧光辐射(XRF)分析仪的辐射安全。     

X-ray Fluorescence Emission Tomography (XFET) with Novel Imaging Geometries - A Monte Carlo Study

This paper presents a feasibility study for using two new imaging geometries for synchrotron X-ray fluorescence emission tomography (XFET) applications. In the proposed approaches, the object is illuminated with synchrotron X-ray beams of various cross-sectional dimensions. The resultant fluorescence photons are detected by high-resolution imaging-spectrometers coupled to collimation apertures. To verify the performance benefits of the proposed methods over the conventional line-by-line scanning approach, we have used both Monte Carlo simulations and an analytical system performance index to compare several different imaging geometries. This study has demonstrated that the proposed XFET approach could lead to a greatly improved imaging speed, which is critical for making XFET a practical imaging modality for a wide range of applications.     

Chemical effects in the Kβ X-ray emission spectra of sulfur

In this work our previous study about chemical effects in the K spectra of S compounds employing high-resolution X-ray spectroscopy has been extended to the Kβ emission spectra. The measurements were performed with a wavelength dispersive single crystal spectrometer operated in the von Hamos geometry having an energy resolution comparable to the natural linewidth of the measured Kβ X-ray lines. The target fluorescence was produced by irradiating the samples with the bremsstrahlung from an X-ray tube. The energies and widths of the main components in the Kβ emission spectrum are given for different sulfur compounds (sulfide, sulfite, sulfate). The measured energy shifts between the Kβ lines of the compounds and elemental sulfur are presented as a function of the sulfur oxidation state and compared with the results obtained from the former K measurements.     

Investigations of structural, dielectric and optical properties on silicon ion irradiated glycine monophosphate single crystals

The 50 MeV silicon ion irradiation induced modifications on structural, optical and dielectric properties of solution grown glycine monophosphate (GMP) crystals were studied. The high-resolution X-ray diffraction study shows the unaltered value of integrated intensity on irradiation. The dielectric constant as a function of frequency and temperature was studied. UV-visible studies reveal the decrease in bandgap values on irradiation and presence of F-centers. The fluorescence spectrum shows the existence of some energy levels, which remains unaffected after irradiation. The scanning electron micrographs reveal the defects formed on irradiation.     

The study of chemical composition and elemental mappings of colored over-glaze porcelain fired in Qing Dynasty by micro-X-ray fluorescence

It is very difficult to measure the chemical composition of colored pigments of over-glaze porcelain by X-ray fluorescence because it contains high concentration of Pb. One of the disadvantages of our polycapillary optics is that it has low transmission efficiency to the high energy X-ray. However, it is beneficial to measure the chemical compositions of rich Pb sample. In this paper, we reported the performances of a tabletop setup of micro-X-ray fluorescence system base on slightly focusing polycapillary and its applications for analysis of rich Pb sample. A piece of Chinese ancient over-glaze porcelain was analyzed by micro-X-ray fluorescence. The experimental results showed that the Cu, Fe and Mn are the major color elements. The possibilities of the process of decorative technology were discussed in this paper, also.     

A novel multicell silicon drift detector module for X-rayspectroscopy and imaging applications

A novel 61-cell silicon drift detector module is proposed for high-counting rates and high-resolution X-ray spectroscopy and imaging applications at energies up to about 30 keV. Its hexagonal geometry with sloped sidewalls allows a buckyball arrangement. Up to 1860 cells of an active area of 5 mm² each can he reached at an average distance to the specimen of only 4.3 cm. An optimized electrical connection concept offers a vertical integration of a sensor array and signal processing electronics. Worst-case crosstalk of 0.3% (-50 dB) and signal loss of 7% (-24 dB) were derived from electrical field analysis. A sandwich of metal foils between the X-ray sensor and electronics reduces the dose of radiation at the electronics by more than eight orders of magnitude. Module-induced background fluorescence reaches its maximum at an incident energy of 13 keV, but remains below 10^-4 of the incoming photon flux at all energies. Three-dimensional (3-D) simulations on thermal module behavior show that the use of graphite as housing material allows an operation with spatial inhomogeneities of <1°C on the sensor's active area. Empirically, we found that the difference between the temperatures of the sensor and the heat sink depends linearly on the power dissipated by the electronics and sensor chip. The corresponding thermal resistances are 4.3 and 0.8 K/W     

Fast peak detector stretchers for use in XAFS applications

In this paper we present two different design approaches to the implementation of fast peak detector-stretchers for X-ray absorption fine structure fluorescence applications (XAFS). After describing the motivations for using peak detector-stretchers in high rate applications, we discuss in detail the design and benefits of their use in a modern nuclear spectroscopy system     

Identification of origin of single aerosol particles using polycapillary X-ray lens

A micro X-ray fluorescence (Micro-XRF) spectrometer based on a polycapillary focusing X-ray lens (PFXRL) and a laboratory X-ray source was designed to carry out the XRF analysis of single aerosol particles. The minimum detection limit (MDL) of this Micro-XRF spectrometer was 9 ppm for the Fe-Kα. The percentage of the particles of vehicle exhaust among aerosol particles was studied in Beijing, Chinese capital, during the test of odd-even driving restrictions for Beijing 2008 Olympics Games. This Micro-XRF spectrometer had potential applications in the analysis of single aerosol particles.     

核技术在核燃料非破坏性分析中的应用和进展

描述了核燃料非破坏性分析技术的概况及核技术在这个领域内的典型应用和进展,如核燃料和核废物中铀、钚含量的快速测定等。所采用的方法如无源γ射线法、X射线法、无源中子计数法及有源中子质询法等。介绍了这些方法的原理、特点和主要用途。     

X-ray scattering in X-ray fluorescence spectra with X-ray tube excitation - Modelling, experiment, and Monte-Carlo simulation

X-ray scattering may contribute significantly to the spectral background of X-ray fluorescence (XRF) spectra. Based on metrological measurements carried out with a scanning electron microscope (SEM) having attached a well characterised X-ray source (polychromatic X-ray tube) and a calibrated energy dispersive X-ray spectrometer (EDS) the accuracy of a physical model for X-ray scattering is systematically evaluated for representative samples. The knowledge of the X-ray spectrometer efficiency, but also of the spectrometer response functions makes it possible to define a physical spectral background of XRF spectra. Background subtraction relying on purely mathematical procedures is state-of-the-art. The results produced by the analytical model are at least as reliable as those obtained by Monte-Carlo simulations, even without considering the very challenging contribution of multiple scattering. Special attention has been paid to Compton broadening. Relevant applications of the implementation of the analytical model presented in this paper are the prediction of the limits of detection for particular cases or the determination of the transmission of X-ray polycapillary lenses.     

A direct comparison of Ge and Si(Li) detectors in the 2-20 keVrange

The spectral response of high-purity Ge (HPGe) and lithium-drifted Si (Si(Li)) surface barrier detectors of similar geometry has been measured over a range of X-ray energies under identical experimental conditions. Detector characteristics such as spectral background, escape peak intensity, entrance window absorption, and energy resolution are presented and compared. Although these characteristics have been discussed previously, the authors attempt to consolidate the information by making comparisons under equivalent experimental conditions for the two types of detectors. A primary goal of the study was a comparison of the two types of detectors for use in X-ray fluorescence applications