共查询到19条相似文献,搜索用时 62 毫秒
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利用同步辐射光电子能谱全电子产额模式(TEY)对石墨、金刚石薄膜和类金刚石薄膜(DLC)的ClsX射线吸收谱进行了研究。在高真空里表面净化处理后,在类金刚石薄膜的Cls吸收谱中分别观察到对应于金刚石sp^3杂化结构成分和石墨sp^2杂化结构成分的特征峰,说明了类金刚石薄膜是由碳sp^2、sp^3两种杂化结构无序混合形成的非晶碳结构;然后,测量了一系列类金刚石薄膜样品的ClsX射线光电子能谱(XPS),得到了每组样品的sp^2、sp^3成分比。 相似文献
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同步辐射微区X射线荧光和吸收谱技术在大气、土壤和动植物分析中的应用 总被引:2,自引:0,他引:2
同步辐射微区X射线荧光(Synchrotron micro-X-ray fluorescence spectroscopy,μ-SXRF)能够对物质进行元素分布分析和微区原位测定,具有高灵敏度、低检出限的特点。同步辐射X射线吸收谱技术(X-ray absorption fine spectroscopy,XAFS)能够提供原子周围的配位环境和化学形态,适用于进行元素形态分析。大气飘尘、土壤和动植物等是环境中元素迁移转化的重要载体,获取具有生物学意义的元素分布和形态,以及准确的定性或定量信息对研究这些元素在环境和生物体中的作用至关重要。随着研究的发展,同步辐射微区分析技术在此领域中得到越来越多的应用。本文介绍了同步辐射技术的基本原理和发展历程,回顾了近几年μ-SRXRF和XAFS技术在大气飘尘、土壤、植物和蚯蚓中元素的分布与形态研究领域的应用进展,对目前应用于此领域遇到的一些挑战进行了概括,并对其未来发展趋势提出了展望。 相似文献
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完成了上海同步辐射装置医学应用光束线和实验站的物理设计,并开始了有关技术设计及其难点的初步考虑。采用一个磁场强度为1.8T、周期数为10的多极扭摆器为冠状动脉心血管造提供所需的强X光束;利用一块Laue弯晶Si(111)单色器可得到比所需大三倍、能量分别在碘吸收边上下的二束单色X光束;造影过程将通过病人座椅的扫描运动和一个双列线形探测器来实现。 相似文献
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本文基于COMET公司MXR225/22型X射线管,使用高纯锗探测器测量了X射线管大、小焦点几种管电压的X射线原始谱,并测量了小焦点下的初始透射谱,在此基础上测量了X射线穿过几种不同材质(铝、钛、铁和铜)吸收片的透射谱。结果表明:X射线管大、小焦点能谱近似相同,低能端X射线比重较大,原始谱中包含铜、银、钨和铅元素的特征峰;初始透射谱低能端硬化明显,并随着管电压升高,高能端所占比重增大,钨特征峰变得明显,X射线平均能量升高,能谱的X射线强度最大区域在最高能量的1/3附近;金属吸收片对X射线硬化明显,硬化效果强烈依赖于其原子序数。相关结果已在工业CT硬化校正中应用,重建图像质量得到改善。 相似文献
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在北京同步辐射装置(BSRF)设计建造了-套基于多层膜偏振元件的软X射线偏振测量分析装置,可工作在双反、双透、前反后透和前透后反四种工作模式,既可作为偏振测量装置,用于同步辐射光束线和多层膜偏振元件偏振特性测量,也可作为通用反射率计,用于多层膜和薄膜的反射或透射率测量,又可用于磁性材料的磁光效应研究等.利用自行研制的装置和光学元件对BSRF的3W1B光束线的偏振特性进行了系统的测量.测量结果指出,在206 eV时,输出光的线偏振度从起偏前的O.585上升到起偏后的0.995,同步光的线偏振度得到极大改善.利用非周期宽带Mo/Si多层膜开展了铁磁性材料的磁光法拉第效应测量,获得了Ni薄膜3p边附近(60-70 eV)的法拉第旋转角度,最大偏转角度在65.5 eV和68 eV分别为1.85±0.19°和-0.75±0.09°. 相似文献
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David Jezeršek Žiga Šmit Primož Pelicon 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(11-12):2006-2009
The in-air beamline at the microanalytical center of the Jo?ef Stefan Institute in Slovenia has recently been upgraded with a wire-mesh current-integration normalization device and a RBS detector in helium flush. For positioning of the targets, the laser-triangulation with 40 μm repeatability was realized using 100 μm wide laser beam and a static camera. Metal plated historical objects were investigated for their gilded and tinned surfaces. Artificial samples were produced by dip-tinning and compared with archaeological samples. A surface roughness was found to be an important parameter for fitting the spectra by the SIMNRA software. 相似文献
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1 Introduction BSRF-3B3 Beamline is a middle-energy (1.5~6 keV), monochromatic, focusable X-ray beam-line constructed in the Beijing Synchrotron Radiation Facility (BSRF) of the Beijing Electron Positron Col-lider (BEPC) in order to develop the work of demarca-tion of detectors for laser diagnosis and middle-energy X ray spectroscopy. Fig.1 is the optical layout of the 3B3 Beamline.Fig.1 Optical layout of 3B3 Beamline. 2 Design of control system The 3B3 Beamline control system (s… 相似文献
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A.G. Class D. Angeli M. Dierckx V. Moreau P. Schuurmans T. Wetzel 《Journal of Nuclear Materials》2011,415(3):378-384
The objective of the European 6th framework Integrated Project (IP) EUROTRANS (EUROpean Research Programme for the TRANSmutation of High Level Nuclear Waste in an Accelerator Driven System) is to demonstrate the feasibility of transmutation of high level nuclear waste using subcritical Accelerator Driven Systems (ADS). The spallation target represents the most challenging new component in an ADS since it is the component coupling the accelerator and the nuclear core and is subjected to very high thermal load in a high radiation field. In this document the thermal hydraulic activities which led to reliable design rules for a windowless target are presented and the status of the heavy liquid metal target mock-up experiment at the KArlsruhe Liquid metal LAboratory (KALLA) are reported. 相似文献
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M. WATANABE 《核技术(英文版)》2006,17(6):354-369
The basic concept of synchrotron radiation beamlines for vacuum ultraviolet and X-ray experiments has been introduced to beginning users and designers of beamlines. The beamline defined here is composed of a front end, pre-mirrors, and a monochromator with refocusing mirrors, which are connected by beam pipes, providing monochromatic light for the experiments. Firstly, time characteristics of the synchrotron radiation are briefly reviewed. Secondly, the basic technology is introduced as the fundamental knowledge required to both users and designers. The topics are photoabsorption by air and solids, front ends and beam pipes, mirrors, monochromators, and filters. Thirdly, the design consideration is described mainly for the designers. The topics are design principle, principle of ray tracing, optical machinery and control, and vacuum. Fourthly, polarization control is considered. The topics are polarizers, polarization diagnosis of beamline, and circularly-polarized light generation. Finally, a brief summary is given introducing some references for further knowledge of the users and the designers. 相似文献
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B.Mattias Mårtenson Sven O. Wilhelmsson 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1985,12(2):273-281
The construction and function of an apparatus intended for negative surface ionization and other desorption studies are described. A molecular beam of the material to be ionized is formed. The number of particles that reaches the ionizer can be measured with a device which is sensitive to the momentum of the particles in the neutral beam. The extraction field is reversible, making it possible to study nonsteady ionization processes and to use the modulated voltage technique, providing a second method to determine the ionization efficiency. The reflection of the neutral beam at the ionizer can be estimated by comparing the two methods. The temperature of the ionizer is measured and controlled by a microcomputer, allowing studies like temperature programmed desorption. Mass analysis and a SEM detector provide a possibility to measure very low ion currents. 相似文献
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一种近衍射限聚焦软X射线显微光束线光学设计 总被引:1,自引:0,他引:1
软X射线扫描显微术、显微谱学等方面的研究需要有纳米量级的聚焦光班,在同步辐射光束线建造中实现X射线的衍射限聚焦十分重要。设计采用了具有较高相干通量的波荡器辐射光源,利用衍射光学元件波带板实现近衍射限成象。引入了沉余照明的概念,以保证成象折空间相干照明。充分考虑水平和垂直方向的相空间匹配问题,以提高输出通量。设计聚焦光班尺寸50nm,输出光通量可达10^9photons/s.0.1%BW。 相似文献