Imaging methods and their application at the ANKA synchrotron light source

The imaging methods used at the ANKA Synchrotron Light Source (Institute for Synchrotron Radiation, Karlsruhe Institute of Technology) are briefly reviewed. Examples of recent applications of the phase-contrast imaging method using a grating interferometer and fast radiography with optic flow data analysis to study static and moving biological objects are presented.     

X-Ray “knife” as a submicrometer tool for studying focusing lens quality

A mobile x-ray “knife” developed by the authors is described. The device is intended for determining the profile of the spatial intensity distribution in the ionizing radiation beam. Its automated motion system combines two actuator types. Significant displacements are performed using a goniometric module with a piezoelectric actuator. The angular step of this module is 1 arc second, which corresponds to a linear displacement of 0.97 μm. As a “fine” drive, a rotating module with a piezoelectric column is used. Its linear step can be varied from 0.01 to 1 μm at a total number of steps of 1000. The x-ray knife was experimentally tested at the Kurchatov Center of Synchrotron Radiation for diagnostics of the parameters of a short-focus x-ray lens at a photon energy of 18 keV. In the vertical direction, the width of the profile for the intensity distribution in the beam formed by the lens was 2.4 μm.     

High-pressure x-ray diffraction station at the beijing synchrotron radiation facility

Abstract

In the second phase construction of further insertion devices, beamlines and experimental stations at the Beijing Synchrotron Radiation Facility, a dedicated high-pressure x-ray diffraction station will be constructed. We outline the synchrotron radiation source, beamline optics and high-pressure x-ray diffraction apparatus. This facility is planned to operate for users in 1994.

Presented at the IUCr Workshop on ‘Synchrotron Radiation Instrumentation for High Pressure Crystallography’, Daresbury Laboratory 20-21 July 1991     

Rietveld analysis for energy dispersive x-ray diffraction under high pressure with synchrotron radiation

Abstract

A new program has been developed for the conversion of energy-dispersive x-ray diffraction spectra obtained from powder samples at high pressure in a diamond anvil cell (DAC) into conventional pseudo angle-dispersive data. The program is compatible with a conventional Rietveld program. This allows the determination of the structural parameters of the samples investigated. Results of a synchrotron radiation study of polycrystalline SrFCl in the tetragonal phase at high pressure are presented.

Presented at the IUCr Workshop on ‘Synchrotron Radiation Instrumentation for High Pressure Crystallography’, Daresbury Laboratory 20-21 July 1991     

Nanoscale carbon tubules deposited in anodic aluminium oxide template： a study of soft x-ray transmission

Well-aligned, catalyst-free nanoscale carbon tubules array was prepared by organic compound vapour deposition method using anodic aluminium oxide (AAO) as a template. The experiment of soft x-ray channelling in such carbon tubules array deposited in AAO template was performed at Beijing Synchrotron Radiation Facility. The transmission of x-rays in carbon tubules array with AAO template support was found even higher than that in bare AAO template at high-energy part of energy spectrum though the porous area of the former was smaller than that of the latter. A qualitative explanation is presented to interpret our results.     

X-ray absorption spectroscopy and high pressure

Abstract

The difficulties of the adaptation of high pressure to x-ray absorption are presented. The advantages of the energy-dispersive geometry are discussed as well as the future improvements expected with the new synchrotron radiation sources.

Presented at the IUCr Workshop on ‘Synchrotron Radiation Instrumentation for High Pressure Crystallography’, Daresbury Laboratory 20-21 July 1991     

Some remarks about double crystal x-ray spectrometer (monochromator) in dispersive (+, −) setting

Some basic properties of double crystal x-ray spectrometer (monochromator) in the dispersive (+, –) setting are summarized. It is shown that the harmonics separation discussed by Bonse et al. may be enhanced by using asymmetric Bragg-case reflections. As an example the spectrometer consisting of Ge(111)-Si (220) dispersive (+, –) setting is discussed.Abstract presented at the VIIth National Synchrotron Radiation Conference, June 3–5, 1986, Novosibirsk.     

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.     

上海光源同步辐射空间干涉仪研制

 研制了上海光源同步辐射空间干涉仪,用于储存环束团横向截面尺寸及发射度的精确测量。对干涉仪工艺设计中的光路参数、关键设备选型、数据处理方法及数据采集处理软件结构进行了分析讨论。结合束流实验完成了系统调试及运行参数优化,结果表明,CCD增益系数与曝光时间设置对测量精度有显著影响,增益系数设为0 dB,曝光时间设为200 ms时,随机测量误差可控制在μm量级。对上海光源储存环横向束斑尺寸进行了精确测量,结果表明:空间相干度曲线近似为高斯分布,可以采用单一空间频率的相干度测量值进行快速束斑尺寸计算;水平束斑尺寸实测值为52.4 μm,与理论值预期值53.0 μm相比,差异小于2%;系统测量误差约为5.5%,主要误差来源为相干度随机测量误差。     

Measurement of optics for the SSRF storage ring in commissioning

The Shanghai Synchrotron Radiation Facility (SSRF) is a low emittance third-generation synchrotron radiation light source. Some optics parameters of the storage ring were measured when commissioning. This report presents the common methods for measuring some optics parameters of the storage ring, including the betatron tune, beta function, chromaticity, natural chromaticity and dispersion. The results and analysis of measurement for the optics parameters are given here, which are indispensable for the orbit correction of the accelerator and the nonlinear optimization.     

AOFSRR 2014 in Taiwan

The Asia-Oceania Forum for Synchrotron Radiation Research (AOFSRR) was formally established by Australia, China, Japan, South Korea, Singapore, Taiwan, and Thailand in 2006. Its objective is to strengthen the collaboration, as well as the inter-communication, among the synchrotron radiation facilities and to promote synchrotron radiation sciences and accelerator-based research in the Asia-Oceania region. Regular meetings have been organized to uphold its objective. The first scientific meeting of AOFSRR took place at KEK, Japan, in 2006. Member countries have been taking turns to organize meetings: Taiwan (NSRRC, 2007), Australia (Australian Synchrotron, 2008), China (SSRF, 2009), South Korea (POSTEC, 2010), Thailand (SLRI, 2012), and Japan (SPring-8, 2013). In 2014, the National Synchrotron Radiation Research Center (NSRRC) hosted the Eighth Asia-Oceania Forum for Synchrotron Radiation Research (AOFSRR 2014) from September 15th to 18th in Hsinchu, Taiwan. The NSRRC is located in the Hsinchu Science Park, within an hour's drive from Taipei, the largest city in Taiwan. Hsinchu is a city not only composed of historical landmarks but also the heartland of high-tech semiconductor industries in Taiwan.     

Design and first commissioning of a new mode with lower emittance in the SSRF storage ring

A new mode is designed with an emittance of 2.47 nm-rad at 3.0 GeV beam energy, lower than the nominal mode of the Shanghai Synchrotron Radiation Facility (SSRF) storage ring. Details of the linear optics design and the nonlinear optimization are presented in this paper. During Phase I commissioning of the storage ring we tested the new optics mode and some expected results were obtained. After restoring the linear optics by means of the linear optics with closed orbit technique, the main parameters of the real machine agree well with the designed values and the injection efficiency and beam lifetime are acceptable.     

Measurement of optics for the SSRF storage ring in commissioning

The Shanghai Synchrotron Radiation Facility (SSRF) is a low emittance third-generation synchrotron radiation light source. Some optics parameters of the storage ring were measured when commissioning. This report presents the common methods for measuring some optics parameters of the storage ring, including the betatron tune, beta function, chromaticity, natural chromaticity and dispersion. The results and analysis of measurement for the optics parameters are given here, which are indispensable for the orbit correction of the accelerator and the nonlinear optimization.     

Electronic structure of single crystal UPd3, UGe2, and USb2 from hard X-ray and angle-resolved photoelectron spectroscopy

Electronic structure of single crystal UPd₃, UGe₂, and USb₂ has been measured from hard X-ray photoelectron spectroscopy (HAXPES) with 7.6 keV photons at the European Synchrotron Radiation Facility (ESRF). Lower photon energy angle-resolved photoelectron spectroscopy (ARPES) was also performed at the Synchrotron Radiation Center (SRC). Herein the following results are presented: (i) ARPES results demonstrate hybridization between the U 5f and Pd 4d electrons within UPd₃. (ii) The greatly reduced surface sensitivity of HAXPES enabled observation of the bulk core levels in spite of surface oxidation. Photoelectron mean-free-path versus oxide layer thickness considerations were used to model the effectiveness of HAXPES for probing bulk features of in-air cleaved samples. (iii) Two distinct features separated by 800 meV were observed for the Sb 3d core level. These two features are attributed to manifestations of two distinct Sb sites within the USb₂ single crystal as supported by consideration of interatomic distances and enthalpy-of-formation. (iv) Doniach–Sunjic line shape analysis of core level spectral features revealed correlations between asymmetry coefficients and 5f localization.     

NSRRC Hosts the FEL Winter School

With continuous support from professors and scientists from the Stanford Linear Accelerator Center (SLAC), Indiana University, National Tsing Hua University, and National Chiao Tung University, the National Synchrotron Radiation Research Center (NSRRC) held the Free Electron Laser (FEL) Winter School on January 18–22, 2016, in Hsinchu, Taiwan for the fourth consecutive year. The five-day program was sponsored by the Physics Research Promotion Center (PRPC) under the Ministry of Science and Technology (MOST) and organized by the NSRRC. Thirty-four applicants were accepted, including 19 undergraduate students, 12 graduate students in master's programs, and three doctoral students.     

From NEXAFS spectroscopy to new flat panel displays: A story of basic science with technological impact

The Twentieth NSRRC Users' Meeting was held successfully at the National Synchrotron Radiation Research Center (NSRRC) in Taiwan from September 10th to 12th, 2014. The three-day meeting was the first such event to be held at the newly furnished Activity Center on the NSRRC campus, celebrating 20 years since the first NSRRC Users' Meeting and highlighting the prospective scientific frontiers marked by the newly established Taiwan Photon Source (TPS) storage ring.     

Recent In-Situ Experiments for Energy-Related Materials from Soochow University-Western University Center for Synchrotron Radiation Research

Soochow University–Western University Center for Synchrotron Radiation Research (SWC or the Center) was officially founded in November 2012 based on an agreement between Soochow University, China, and Western University, Canada. The mandate of the Center is to promote synchrotron-based research through collaborations among Center members and other synchrotron scientists in both research and education, particularly in the fields of nanomaterials and devices, materials for energy and the environment, chemical biology, as well as the development and application of novel synchrotron capabilities and theory.     

Large volume high pressure research using the wiggler port at NSLS

Abstract

A DIA-type cubic-anvil high pressure apparatus (SAM-85) has been interfaced with white x-ray radiation from the superconducting wiggler port of the National Synchrotron Light Source at Brookhaven National Laboratory. Energy-dispersive x-ray diffraction measurements can be obtained for samples with dimensions of the order of 1 mm as a function of pressure and temperature utilizing x-ray energies of up to100 keV.

The sample environment is examined. Pressure is uniform in the sample chamber to within 0.1 GPa, and temperature is constant in the scattering volume to within 5°C.A method is defined for determining deviatoric stress. We find that for a sample containing NaCl and Au, the deviatoric stress increases to about 0.3 GPa as pressure increases to 1.5 GPa and then remains constant, probably reflecting the strength of the sample. Upon heating, the deviatoric stress quickly approaches zero.

Presented at the IUCr Workshop on ‘Synchrotron Radiation Instrumentation for High Pressure Crystallography’, Daresbury Laboratory 20-21 July 1991     

软x射线平面镜不同掠射角下的反射率标定

报道了平面反射镜在不同掠射角下的反射率标定实验.实验利用北京同步辐射装置(BSRF)-3W1B束线及反射率计靶室，在束流强度40—120 mA、贮存环电子能量2 GeV专用光运行模式下，在50—1500 eV能区，做了四种材料平面镜在不同掠射角下的反射率标定.标定过程用高灵敏度无死层的硅光二极管代替x射线二极管作探测器，使输出信号提高2—3个数量级.最终给出C，Si，Ni和Au四种材料平面镜在1°—7°掠射角下的反射率标定曲线，并把实验数据与理论计算值进行了比对和分析. 关键词： 同步辐射 平面镜 反射率 标定