共查询到20条相似文献,搜索用时 0 毫秒
1.
Bing-Gang Feng Fen Tao Yi-Ming Yang Tao Hu Fei-Xiang Wang Guo-Hao Du Yan-Ling Xue Ya-Jun Tong Tian-Xi Sun Biao Deng Ti-Qiao Xiao 《核技术(英文版)》2018,(6)
X-ray fluorescence microtomography(μXFCT)is a nondestructive analytical technique and has been widely used to nondestructively detect and quantify the elemental composition and distributions in samples. Usually, synchrotron radiation X-rays are used for μXFCT, due to its high flux density. In this paper, a laboratory-sourcebased μXFCT system was developed, in which a polycapillary lens is employed to focus the X-ray beam and improve the flux density. The maximum likelihood expectation maximization algorithm was used to reconstruct the computed tomography slices at a limited number of projections. The experimental results demonstrated that the developed system could reveal the elemental distribution inside the test sample, with an elemental sensitivity of 1000 ppm. 相似文献
2.
Claudio Tuniz Roberto Devoti Giuseppe Santoro Franco Zanini 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1990,50(1-4):338-342
A synchrotron radiation microscope based on X-ray fluorescence and computed microtomography for advanced applications in biomedicine, environmental sciences, geology and materials science is described. This microscope will utilize the radiation produced by a bending magnet of ELETTRA, the third-generation, high-brilliance synchrotron radiation facility being built in Trieste. Various wide-band-pass mirror systems operating in an energy range between 7 and 17 keV have been designed. For example, multilayer-coated mirrors in the Kirkpatrick-Baez configuration can produce a spatial resolution of 1 μm2 for a flux in excess of 108 photons per second on the sample (E = 12 keV, E/ΔE = 10). This X-ray microprobe will allow micrometric mapping of trace and minor elements and computed tomographic imaging with high resolution, opening a new realm of experiments in different fields of science, such as in vivo elemental scanning and microtomography of cultured cells, analysis of single atmospheric particulates, analysis of cosmic debris collected from the stratosphere and antarctic ice, etc. The preliminary design of the beam line and the performance of the microprobe are discussed. 相似文献
3.
Jingke Qiu Biao DengQun Yang Fen YanAiguo Li Xiaohan Yu 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(22):2662-2666
Synchrotron-based X-ray micro-fluorescence (μ-SXRF) is a non-destructive analytical technique and has been widely used to detect and quantify the elemental composition of samples in their natural state. To determine the internal elemental distributions within samples, X-ray fluorescence microtomography has been developed based on the hard X-ray microprobe at beamline BL15U1 of the Shanghai Synchrotron Radiation Facility (SSRF) in Shanghai, China. This technique was applied to image the cross-sectional distributions of multiple elements within a single human hair, and its validity was evaluated by comparing the results with the elemental maps of a thin hair section obtained using the well-established μ-SXRF mapping method. Elemental images of S, Ca, Mn, Fe, Cu, and Zn within a virtual slice of the hair were reconstructed after the tomographic measurements. The tomographic images of heavy elements like Fe, Cu, and Zn were found to be in good agreement with the corresponding μ-SXRF maps. Light elements, such as S, however, represented different patterns due to non-negligible self-absorption in the sample, and sophisticated correction algorithms accounting for such effects are required for obtaining qualitatively and quantitatively more accurate images. Compared to μ-SXRF mapping, X-ray fluorescence microtomography reduces the sample preparation requirements and has been demonstrated in this work as being a more ideal and effective imaging modality to non-destructively mapping out the internal distribution of heavy elements within samples at the micrometer scale at the SSRF. 相似文献
4.
A computer simulation is used to study the problem of internal scattering for targets that are imaged using X-ray microtomography. A strategy is outlined for selecting X-ray energy and image resolution based on properties of the material being imaged. The X-ray scanning process is simulated by applying a Monte Carlo technique to a modeled target that emulates the material properties of a microelectronic device. The X-ray photons are subject to photoelectric absorption, Rayleigh scattering, and Compton scattering. The simulation applies a method of high-resolution image reconstruction based on discrete Fourier transforms. Examples of reconstructed images that have 0.5-μm spatial resolution are shown for images of simulated lead and aluminum targets 相似文献
5.
6.
越来越多的研究表明,皮肤中的组织液可以沿纤维轨道长程流动。这种以纤维丝为轨道的液体流动与真皮层和皮下组织层的纤维骨架有关,而其中的三维纤维骨架结构尚未得到表征。利用上海同步辐射光源BL13W1线站的X射线相衬显微断层成像技术,得到了真皮层和皮下组织层内部的三维纤维骨架结构,结合计算机图形处理技术,成功表征了人体皮肤中的三维纤维骨架结构,发现真皮层中的纤维骨架具有长程有序且与真皮深度紧密联系的分布特征。为理解皮肤中组织液的长程流动现象提供了一种高分辨率的表征方法。 相似文献
7.
8.
使用X光聚束系统的X射线荧光分析研究 总被引:2,自引:0,他引:2
复合光导管组成的X光透镜可将发散的X光束聚至直径φ0.5mm,聚束后的功率密度增加10^4倍,这种新型的X光透镜已用于X射线荧光分析研究,使用X光管功率仅2W,而探测限可达10^-9-10^10g. 相似文献
9.
针对印刷电路板中BGA器件焊点缺陷检测数字化成像问题,设计了一套应用Matrox公司的MeteorII-CameraLink型号采集卡及HAWK-160XI型X-射线源和UNIQ-1800 CCD相机组成的高分辨率X-射线缺陷检测系统。经试验测试最佳放大率下系统分辨率17 lp/mm,缺陷分析精度最小分辨率达到0.03 mm,并给出测试采集效果图。 相似文献
10.
11.
T. ?echák L. Musílek T. Trojek 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2007,263(1):54-57
X-ray fluorescence can be successfully used for analysing the elemental composition of the superficial layers of a measured object, especially for investigating surface coatings, deposits of adventitious materials on the surface, etc. An energy dispersive version of X-ray fluorescence analysis is used in our investigations for analysing various historic objects, art works and archaeological finds. Examples of the application of X-ray fluorescence to various archaeological finds from excavations in the Czech Republic are presented - shards of ancient glazed ceramics, moulds for casting metal products, the remains of a human finger with traces of brass, probably from a ring, etc. 相似文献
12.
J. Bontaz-Carion L. Soulard 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(3-4):379-382
Dynamic ductile damage has been created by a laser driven shock. The study of these processes consists of predicting it and analysing spatial distributions of pores observed in the target. The challenge is to use the Molecular Dynamics to calculate the propagation of shock waves in ultra thin sheets of metal as well as to compare results with ESRF’s X-ray microtomography. 相似文献
13.
S. Fritzsche A. M. M. Mohammedein G. Musiol I. Reiche F. Schubert G. Zschornack 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1990,50(1-4):353-357
For use in basic and applied research, an atomic data library with atomic-emission and -structure data was developed by using an EC 1055/56 computer facility. The data files contain X-ray transition data, orbital data. Auger-transition data and photon mass attenuation coefficients for all elements up to uranium. The data are stored in a generalized format that permits suitable data handling considering the features of atomic data sets. The data are available either in book form, computer listings or as files on magnetic tape. Computer codes for calculation of radiative and nonradiative transition probabilities have been developed and successfully tested for various configurations of neutral and ionized atoms. 相似文献
14.
从对USB总线技术及GPS技术应用于现场X荧光分析仪的可行性进行了分析,并重点介绍了USB总线及多道脉冲分析器硬件设计和下位机固件设计。简要介绍了设备驱动程序设计以及上位机软件设计。 相似文献
15.
16.
放射性同位素X荧光测井技术的研究 总被引:3,自引:0,他引:3
对放射性同位素源X荧光测井技术的井液效应,井壁不平度效应和基体效应分别提出了实用的校正技术。野外锶矿X荧光测井试验表明:X荧光测井确定的锶矿层厚度和平均品位与传统的岩芯化学分析结果相比较,其相对误差〈10%,符合锶矿储量计算要求;X荧光测井可在井场实时提供测井结果,而耗时却短得多。 相似文献
17.
The application of the laser induced fluorescence technique to the study of liquid mixing in the downcomer of a pressurized water reactor is presented. The scenario is that of a boron dilution event, in which a deborated slug is set in motion by the actuation of a reactor coolant pump. A separate effects test facility, built with transparent plexiglas, is used to conduct optical measurements of the slug mixing along its path to the core. The optical assembly is described and the conditions for the implementation of laser induced fluorescence as a quantitative measurement technique are discussed. Results from a slug injection experiment are shown which demonstrate the high-resolution capabilities of this procedure as applied to the study of liquid mixing in the complex geometry of a reactor vessel downcomer. 相似文献
18.
19.
《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1998,145(3):401-408
Fluorescent soft X-ray carbon Kα emission spectra (XES) have been used to characterize the bonding of carbon atoms in polyimide (PI) and polycarbosilane (PCS) films. The PI films have been irradiated with 40 keV nitrogen or argon ions, at fluences ranging from 1 × 1014 to 1 × 1016 cm−2. The PCS films have been irradiated with 5 × 1015 carbon ions cm−2 of 500 keV and/or annealed at 1000°C. We find that the fine structure of the carbon XES of the PI films changes with implanted ion fluence above 1 × 1014 cm−2 which we believe is due to the degradation of the PI into amorphous C:N:O. The width of the forbidden band as determined from the high-energy cut-off of the C Kα X-ray excitation decreases with the ion fluence. The bonding configuration of free carbon precipitates embedded in amorphous SiC which are formed in PCS after irradiation with C ions or combined treatments (irradiation and subsequent annealing) is close to either to that in diamond-like films or in silicidated graphite, respectively. 相似文献
20.