弱谐波情况下透射光栅衍射效率标定方法

同步辐射光源中的高次谐波会使透射光栅衍射效率标定精度变差。为了校正光源中的高次谐波对透射光栅衍射效率标定的影响,提出了一种光源存在弱谐波情况下的透射光栅衍射效率标定方法,通过使用谐波X射线的衍射效率修正基波衍射效率标定中谐波的影响,从而得到更为准确的透射光栅衍射效率。使用该标定方法在北京同步辐射光源上开展了透射光栅相对衍射效率标定工作。实验结果表明:在100~800eV存在高次谐波能段,修正后透射光栅一级与零级的相对衍射效率与理论模拟结果吻合较好,修正后光栅二级与一级的相对衍射效率更接近理论模拟结果,但与理论模拟结果仍有较大偏差,该偏差主要来源光栅较弱的二级衍射。     

X射线（n,—n）双晶衍射抑制高次谐波实验研究

对将用于同步辐射ＥＸＡＦＳ 实验站双晶单色器的晶体进行了双晶衍射失谐抑制高次谐波的实验．结果表明，对Si(111）晶体，当双晶衍射失谐到基波强度只有原来的一半时，高次谐波均消失．本文讨论了Si（２２２）衍射不完全消光的原因．对Si（２２０）晶体衍射的情况也进行了简要的讨论．     

KTP(001)晶体分光性能研究

根据同步辐射光源对软X射线分光晶体的性能要求,分析了软X射线能区常用分光晶体的性能优劣,指出对于晶格常数值大的分光晶体,KTP(KTiOPO₄)(011)是该能区比较理想的分光晶体. 同时提出了一种利用同步辐射光源测量晶体衍射效率的实验方法,指出光源的发散度与晶体的衍射效率密切相关. 测量了KTP(011)晶体的晶格常数,给出了KTP(011)晶体的实测衍射效率. 关键词： 同步辐射 KTP(011)晶体 衍射效率 光源发散度     

应用同步辐射光源的表面物理研究—现状与展望

本文综述了应用同步辐射光源的几种主要表面物理研究技术。内容包括:同步辐射光电子能谱(SRPES)、表面广延X射线吸收边精细结构(SEXAFS)、光电子衍射(PED)和掠角入射X射线衍射(GIXD)等。对每种技术的原理、应用实例和最新进展都作了较详细的介绍。     

应用同步辐射光源的表面物理研究—现状与展望

本文综述了应用同步辐射光源的几种主要表面物理研究技术。内容包括:同步辐射光电子能谱(SRPES)、表面广延X射线吸收边精细结构(SEXAFS)、光电子衍射(PED)和掠角入射X射线衍射(GIXD)等。对每种技术的原理、应用实例和最新进展都作了较详细的介绍。     

衍射增强成像方法中两种晶体排列方式的对比研究

北京同步辐射装置(BSRF)4W1A光束线形貌学实验站近两年开展了两块晶体的衍射增强成像实验研究，在实验中，晶体转轴垂直于同步辐射偏振面时的图像质量好于晶体转轴平行于同步辐射偏振面时获取的图像.本文从X光强度分布、单色器晶体的热膨胀、空间分辨率、角分辨率等方面系统地对两种晶体几何排列方式进行了比较研究.实验和理论分析的结果表明，晶体转轴垂直于同步辐射偏振面时单色器晶体上的热膨胀对成像的影响较小，因而获得了更好的成像质量. 关键词： 同步辐射 衍射增强成像 晶体衍射     

用同步辐射X射线衍射技术分析GaN/Si外延膜的结构与应变

选用有AlN和AlGaN缓冲层的GaN/Si作为测试样品,采用同步辐射X射线衍射(SRXRD)技术对样品外延膜(GaN)的几何结构、晶格常量及其应变进行了分析.结果表明,同步辐射X射线衍射实验可以作为一种有效的技术手段,测试固体结构及应变.     

光学仪器 X射线、紫外线及其仪器

O434．19 2005043172 同步辐射硬X射线衍射增强成像新进展=Diffraction-en- hanced imaging experiments in BSRF[刊,中]／黄万霞(中科院高能物理研究所,北京(100039)),袁清习…／／物理学报,-2005,54(2),-677-681 在北京同步辐射装置(BSRF)4w1A束线上,对衍射增强成像方法进行了研究,并对一系列生物医学样品及材料样品成像,得到了非常清晰的相位衬底图像。图5参19 (杨妹清)     

光学速调管自发辐射谱的测量及调制率的提高

 在国家同步辐射实验室(NSRL)800MeV 电子储存环上进行的相干谐波储存环自由电子激光研究中, 测量了光学速调管的自发辐射谱并提高了它的调制率。     

同步辐射高压单晶衍射实验技术

利用同步辐射光源开展高压X射线衍射(X-ray diffraction,XRD)研究已有近四十年的历史,并且已经取得了非常丰硕的成果.单晶XRD作为高压研究的一部分,在同步辐射装置上的应用也有了接近三十年的历史.近年来,随着同步辐射光学技术以及高压技术、特别是大衍射窗口金刚石对顶砧压腔(diamond anvil cell,DAC)的改进与发展,同步辐射高压单晶衍射实验方法在高压研究中的应用越来越普及.由于能够在压力条件下获得样品在三维空间中的衍射信息分布以及数据具有高信噪比等优势,单晶XRD实验方法不仅可以用于压力条件下的晶体结构解析,如获取晶胞参数、空间群、原子坐标以及原子占位等信息,而且可进一步做晶体电荷密度分析研究,得到更多的化学键、电荷分布及其变化等信息.本文主要介绍同步辐射高压单晶XRD实验方法及相关技术,其中包括单晶XRD实验系统、单晶XRD所用DAC、单晶样品装填以及单晶XRD数据处理等内容.     

Spatial modulation of diffracted X-ray beam by bulk acoustic waves

Laue-geometry X-ray diffraction has been studied experimentally in quartz crystals excited by bulk acoustic waves. These waves deform reflecting atomic planes, which leads to spatial modulation of diffracted beams. We show that in the beam section perpendicular to the diffraction vector the intensity stripes appear whose number depends on the order of harmonic of the excited acoustic field. The intensity of appearing fringes depends on the amplitude of alternative voltage applied to the crystal.     

LiNbO3晶体在75℃附近赝考塞耳线衍射异常

用X射线发散束背反射赝考塞耳线衍射方法发现纯LiNbO₃和扩Ti的LiNbO₃晶体在75℃附近的衍射花样有明显的异常。(11010),(01110),(0118),(1108),(03312),(33012)等衍射面的考塞耳花样出现成对的大范围非断裂的畸变。畸变接近二次对称,对称面为x面。破坏了沿z轴方向的三次对称性。同时发现高角度的衍射面畸变α较小,或不畸变。布喇格角较小的衍射面畸变较甚。 关键词：     

RAP晶体积分衍射效率的实验研究

以北京同步辐射装置的4B7中能束线为光源,对RAP（邻苯二甲酸氢銣）晶体的积分衍射效率进行了实验标定.结果显示:晶体在不同能量段都得到了完整的衍射峰,扭摆曲线的光滑性和对称性较好,在偏离布喇格角以后衍射效率都迅速下降到本底量级.在2.1~5.8 keV范围内,晶体的积分衍射效率在1×10－4rad左右.     

Experimental observation of parametric X-ray radiation directed along the propagation velocity of relativistic electrons in a tungsten crystal

Parametric X-ray radiation (PXR) due to dynamic diffraction of relativistic electrons is experimentally observed at small angles to the propagation velocity of electrons in a tungsten crystal. The specific features of the experimental method are described, and forward PXR reflections from two crystallographic planes of tungsten are reliably measured.     

Effect of mutual orientation of the lattice of a single-crystal radiator and its outer surface on X-ray transition radiation characteristics

X-ray transition radiation (TR) of relativistic electrons crossing a single crystal target in the Bragg scattering geometry is considered within the framework of a dynamic diffraction theory. Analytical expressions are obtained for the TR spectral-angular distribution taking into account crystal surface orientation with respect to atomic planes. It is shown that at a fixed angle of electron incidence onto a system of atomic planes of the crystal the TR spectral-angular characteristics in the region of Bragg frequencies strongly depend on the orientation of the entrance surface of the target. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 37–42, June, 2006.     

Polychromatic focusing of x-rays in Laue-case diffraction

It is shown that, if a thin single crystal with the diffracting planes perpendicular to its surface is bent into hyperbolical shape, then x-rays from a point source located in one focus of a hyperbola are focused into the second focus of the hyperbola after symmetrical Laue-case diffraction. The basic properties of the hyperbolic spectrograph are discussed and compared with the elliptical spectrograph with Bragg-case diffraction.     

X-ray diffraction in AT-cut quartz single crystal at acoustic excitation at the fundamental frequency

X-ray diffraction on different atomic planes of an AT-cut quartz crystal is studied experimentally in the Laue geometry in case of excitation by acoustic waves at the first resonant (fundamental) frequency. Acoustic waves lead to an increase in the integral intensity of the reflection-diffracted beam. The amplification coefficients in reflection are measured in dependence on the amplitude of a.c. voltage applied to the crystal at the resonant frequency. The frontal distributions of the intensity of the beam diffracted in the reflection direction are obtained for different atomic planes.     

邻苯二钾酸氢铊晶体积分衍射效率的标定

 以北京同步辐射实验室4B7中能束线为光源，在2.1~6.0 keV的范围内对邻苯二钾酸氢铊(TlAP)平面晶体一、二 、三级衍射的积分衍射效率进行了精确的实验标定。标定结果表明：TlAP晶体有较高的峰值衍射率； 其一级衍射的积分衍射效率向低能端有增加的趋势，而在2.6~5.4 keV的范围内大约为1.53×10^-4 rad；随着衍射级次的提高，衍射效率逐渐减小，二级衍射的积分衍射效率约为一级衍射效率的1/4，三级衍射结果比一级衍射下降一个量级。实验所标定的TlAP晶体可用于平晶谱仪对激光等离子体X射线光谱的定量分析。     

全息聚合物弥散液晶材料衍射特性的优化

研究了影响全息聚合物弥散液晶(HPDLC)衍射效率的主要因素，分析了衍射效率与聚合物单体的选择、曝光强度、曝光时间、液晶含量及温度的依赖关系，从而找到最佳条件，使衍射特性得到优化.目前测得的最大衍射效率为802%.实验中还研究了扫描电镜(SEM)观察下HPDLC的表面形貌.     

High pressure x-ray diffraction techniques with synchrotron radiation

This article summarizes the developments of experimental techniques for high pressure x-ray diffraction(XRD) in diamond anvil cells(DACs) using synchrotron radiation. Basic principles and experimental methods for various diffraction geometry are described, including powder diffraction, single crystal diffraction, radial diffraction, as well as coupling with laser heating system. Resolution in d-spacing of different diffraction modes is discussed. More recent progress, such as extended application of single crystal diffraction for measurements of multigrain and electron density distribution, timeresolved diffraction with dynamic DAC and development of modulated heating techniques are briefly introduced. The current status of the high pressure beamline at BSRF(Beijing Synchrotron Radiation Facility) and some results are also presented.