共查询到19条相似文献,搜索用时 93 毫秒
1.
2.
3.
4.
X射线衍射和倒易点阵概念抽象,是学习的难点,X射线衍射分析的理论基础是倒易点阵,倒易点阵构建的基础是X射线衍射,两者互为基础.然而,大部分教科书中X射线衍射和倒易点阵都是分开讲解,更是给学习理解带来了困难,本文系统介绍了X射线衍射原理,并基于X射线衍射引出倒易点阵,将X射线衍射和倒易点阵统一讲解,使学习理解更加容易. 相似文献
5.
6.
多层膜闪耀光栅衍射的运动学研究 总被引:1,自引:0,他引:1
用 X射线运动学理论对软 X射线多层膜闪耀光栅的衍射特性进行了详细的研究 ,得到了衍射规律的一般表达式 ,讨论了产生衍射极大值的条件、光谱特性 ,不同于光栅和多层膜的色散特性。以及用作软 X射线单色器的一般性问题。发现只要选择合适的光栅参数 ,便可以将衍射光的大部分能量集中到某一个非零衍射级上。 相似文献
7.
8.
采用每毫米1000线的自支撑透射光栅配上背照射软X射线CCD(charge coupled device)组成了透射光栅谱仪,利用北京同步辐射装置(BSRF)3W1B光束线软X射线实验站上X射线源分别对透射光栅的衍射效率和软X射线CCD的响应灵敏度进行了准确的实验标定,获得了150eV到1500eV能区的绝对衍射效率和响应灵敏度的实验结果;同时在国内外研究工作的基础上,发展了自己的透射光栅衍射效率理论计算模型和X射线CCD响应灵敏度计算模型,开展了相应的理论计算和实验标定结果比对工作,理论和实验符合较好, 相似文献
9.
同步辐射X射线三维显微成像 总被引:2,自引:0,他引:2
本介绍了利用同步辐射进行X射线三维成像的工作原理及进展状况,详细论述了X射线三维成像的两种方法,X射线全息及CT技术,以及通过两的结合(HCT)进行高分辨率三维成像的有关理论与实验技术;介绍了同轴全息中消除“双生像”噪声的数字方法,讨论了影响分辨率的各种因素;本还介绍了在国家同步辐射实验室软X射线实验站进行的生物样品X射线三维成像的实验及其结果。 相似文献
10.
考虑到不同深度的晶面对X射线吸收的差别,导出了X射线衍射线形状的曲线,获得了精确的衍射曲线形状的表达式,讨论了吸收对衍射峰形状的影响.最后还对理论与实验结果进行了比较. 相似文献
11.
12.
Chung‐Jong Yu Hae Cheol Lee Chan Kim Wonsuk Cha Jerome Carnis Yoonhee Kim Do Young Noh Hyunjung Kim 《Journal of synchrotron radiation》2014,21(1):264-267
The coherent X‐ray scattering beamline at the 9C port of the upgraded Pohang Light Source (PLS‐II) at Pohang Accelerator Laboratory in Korea is introduced. This beamline provides X‐rays of 5–20 keV, and targets coherent X‐ray experiments such as coherent diffraction imaging and X‐ray photon correlation spectroscopy. The main parameters of the beamline are summarized, and some preliminary experimental results are described. 相似文献
13.
概述了整体X光透镜的物理性能及其在X射线衍射技术中的应用研究,介绍了所研制的新型衍射装置及其测量结果. The basic physical properties and applications in X ray diffraction technology for the monolithic capillary lens are described. The new designed diffraction facility and its measurment results are laso introduced. 相似文献
14.
在利用步辐射光源的偏振特性进行自旋相关X射线散射及吸收谱实验来研究材料的磁学性质时,需要应用圆偏振光,这就提出了对具有高通量、高偏振度' 长连续可调的圆偏振X射线的需求;另一方面标定实验所用X射线的圆偏振度也成为这一研究领域的关键技术。由于X射线多光束衍射强度与σ场和π场的光程差δ相关,通过测量圆偏振分析晶体的多光束衍射的强度分布,可以获得入射X射线的圆偏振度。实验在美国国家同步辐射光源实验室X25光束线实验站进行,光子能量为7.1keV的圆偏振X射线由线偏振X射线经过一厚度为0.5mm、晶面为[111]的金刚石晶体产生。通过测量多光束衍射强度,确定了斯托克斯参量。实验值与X射线动力学理论计算结果能较好地吻合。 相似文献
15.
Keiichi Hirano Yoshiki Yamashita Yumiko Takahashi Hiroshi Sugiyama 《Journal of synchrotron radiation》2015,22(4):956-960
A novel X‐ray Bragg optics is proposed for variable‐magnification of an X‐ray beam. This X‐ray Bragg optics is composed of two magnifiers in a crossed arrangement, and the magnification factor, M, is controlled through the azimuth angle of each magnifier. The basic properties of the X‐ray optics such as the magnification factor, image transformation matrix and intrinsic acceptance angle are described based on the dynamical theory of X‐ray diffraction. The feasibility of the variable‐magnification X‐ray Bragg optics was verified at the vertical‐wiggler beamline BL‐14B of the Photon Factory. For X‐ray Bragg magnifiers, Si(220) crystals with an asymmetric angle of 14° were used. The magnification factor was calculated to be tunable between 0.1 and 10.0 at a wavelength of 0.112 nm. At various magnification factors (M≥ 1.0), X‐ray images of a nylon mesh were observed with an air‐cooled X‐ray CCD camera. Image deformation caused by the optics could be corrected by using a 2 × 2 transformation matrix and bilinear interpolation method. Not only absorption‐contrast but also edge‐contrast due to Fresnel diffraction was observed in the magnified images. 相似文献
16.
刘小珍 《光谱学与光谱分析》1998,18(5):614-616
本文用电感耦合等离子体原子发射光谱法,X射线荧光光谱法、红外光谱以及X射线衍射谱测定了石棉红花岗石和芝麻白花岗石的成分和光谱、根据石棉红岗石和芝麻白花岗石的X射线衍射谱,用计算机检索它们的组成,对计算机检索的结果进行对比得出,石棉红花岗石的红色是由于它含有Fe的红色矿物而产生的。 相似文献
17.
18.
19.
Olivier Lazzari Christopher K. Egan Simon D. M. Jacques Taha Sochi Marco Di Michiel Robert J. Cernik Paul Barnes 《Journal of synchrotron radiation》2012,19(4):471-477
A new data collection strategy for performing synchrotron energy‐dispersive X‐ray diffraction computed tomography has been devised. This method is analogous to angle‐dispersive X‐ray diffraction whose diffraction signal originates from a line formed by intersection of the incident X‐ray beam and the sample. Energy resolution is preserved by using a collimator which defines a small sampling voxel. This voxel is translated in a series of parallel straight lines covering the whole sample and the operation is repeated at different rotation angles, thus generating one diffraction pattern per translation and rotation step. The method has been tested by imaging a specially designed phantom object, devised to be a demanding validator for X‐ray diffraction imaging. The relative strengths and weaknesses of the method have been analysed with respect to the classic angle‐dispersive technique. The reconstruction accuracy of the method is good, although an absorption correction is required for lower energy diffraction because of the large path lengths involved. The spatial resolution is only limited to the width of the scanning beam owing to the novel collection strategy. The current temporal resolution is poor, with a scan taking several hours. The method is best suited to studying large objects (e.g. for engineering and materials science applications) because it does not suffer from diffraction peak broadening effects irrespective of the sample size, in contrast to the angle‐dispersive case. 相似文献