PETRA IV Workshop on Research with High-Energy X-rays at Ultra-Low Emittance Sources

Recent advances in storage ring technology pioneered by MAX IV (Sweden) allow synchrotron radiation sources to achieve significantly smaller emittances than those currently in operation. This new, multi-bend achromat technology can thus boost spectral brightness, enabling unprecedented experimental possibilities. The high-energy synchrotron radiation facilities ESRF (France), SPring-8 (Japan), and APS (USA) have settled upgrade plans to improve their storage ring emittance by up to two orders of magnitude at 6 GeV electron energy. PETRA III at DESY has the largest circumference with 2.3 km. As the emittance scales favorably with the storage ring size, an upgrade of PETRA III offers the unique potential to reach a diffraction limit up to X-ray energies of 10 keV. Operating at 6 GeV with an emittance of 10 pmrad, this PETRA IV facility would pave the way for new experimental opportunities, especially for those using high photon energies.     

同步辐射X射线荧光光谱国内外研究进展

同步辐射光源是带电粒子在加速器储存环中以接近光速的速度运动时,沿轨道切线方向发射出的辐射,同步辐射X射线荧光分析(SR-XRF)是以同步辐射X射线作为激发光源的X荧光光谱分析技术.同步辐射X射线荧光分析包括了用于微区及微量元素分析的同步辐射XRF、用于表面及薄膜分析的同步辐射全反射X射线荧光(SR-TXRF)以及用于三...     

上海光源硬X射线相干衍射成像实验方法初探

相干X射线衍射成像方法是一种先进的成像技术,分辨率可达纳米量级.国际上大多数的同步辐射装置和自由电子激光装置都建立了该成像方法,并有将其作为主要成像技术的趋势.上海光源作为目前国内唯一的一台第三代同步辐射光源,尚未建立基于硬X射线的相干衍射成像实验平台.随着一批以波荡器为光源的光束线站投入使用,使得该方法的建立成为了可能.本文基于上海光源BL19U2生物小角散射线站,通过有效的光路设计,搭建了相干衍射实验平台,在12 keV和13.5 keV能量点均获得了硬X射线相干光束,并基于小孔衍射测量了入射光束的空间相干长度.该平台支持常规和扫描相干衍射实验模式,对小孔衍射图样及波带片扫描衍射图样实现了正确的相位重建,证明了该平台初步具备开展硬X射线相干衍射成像实验的能力.硬X射线相干衍射成像实验平台为国内首次建立,将为国内该实验方法的发展和应用提供有效的软硬件支持.     

X-ray scattering: A powerful probe of lattice strain in materials with small dimensions

X-ray diffraction was recognized from the early days as highly sensitive to atomic displacements. Indeed structural crystallography has been very successful in locating with great precision the position of atoms within an individual unit cell. In disordered systems, it is the average structure and fluctuations about it that may be determined. In the field of mechanics, diffraction may thus be used to evaluate elastic displacement fields. In this short overview, we give examples from recent work where X-ray diffraction has been used to investigate average strains in lines, films or multilayers. In small objects, the proximity of surfaces or interfaces may create very inhomogeneous displacement fields. X-ray scattering is again one of the best methods to determine such distributions. The need to characterize displacement fields in nano-structures together with the advent of third generation synchrotron radiation sources has generated new and powerful methods (anomalous diffraction, coherent diffraction, micro-diffraction, etc.). We review some of the recent and promising results in the field of strain measurements in small dimensions via X-ray diffraction.     

Application of high-energy synchrotron-radiation XPS to determine the thickness of SiO2 thin films on Si(100)

The escape depth of photoelectrons depends on their kinetic energy. We apply this relationship to measure film thicknesses from X-ray photoelectron spectroscopy (XPS) measurements with tunable-energy synchrotron radiation (SR). For this purpose, a “high-energy SR-XPS” instrument has been constructed and used to characterize thermally oxidized thin films on Si(100) single crystals. In order to observe photoelectrons emitted from deeper regions than with conventional XPS, Si 1s photoelectrons with an energy up to 4000 eV were measured with X-ray energies up to 5800 eV. The oxide thickness was estimated from measurements of the relative Si intensities from the oxide and the substrate at various photon energies. Our results suggest that the SR-XPS system is useful for measuring the thickness of thin films.     

同步辐射X射线相衬显微CT在古生物学中的应用

X射线无损成像技术在古生物化石标本研究领域中应用十分广泛.近几年来,随着技术的不断革新,同步辐射X射线相衬显微断层成像技术(SRX-PC-μCT)也被引入到这一领域.由于同步辐射光源产生的硬X射线具有高亮度、高准直性和高空间相干性等优点,可以实现化石标本高分辨率（亚微米级）的无损三维显微成像,给古生物学的发展带来了新的机遇.文章简要回顾了用于古生物化石标本无损成像技术的发展历程,并在此基础上综述了同步辐射X射线断层显微成像技术在古生物学领域的应用现状和前景.     

Surface X-ray diffraction study of boron-nitride nanomesh in air

The hexagonal boron-nitride ‘nanomesh’ surface reconstruction on Rh(1 1 1) [Corso et al., Science 303 (2004) 217-220] has been investigated using surface X-ray diffraction utilizing synchrotron radiation. This unique structure has been found to be stable under ambient atmosphere which provides an important basis for technological applications like templating and coating. The previously suggested (12 × 12) periodicity of this reconstruction has been unambiguously confirmed and structural features are discussed in the light of the X-ray diffraction results.     

Diffraction gratings for short-wave radiation: Modern requirements and achievements

Recent achievements in the field of making and certifying gratings for the soft X-ray and extreme ultraviolet regions are described, including those intended for space flights and having new or record characteristics of diffraction efficiency. The diffraction efficiency of gratings is investigated both by computation using the electromagnetic PCGrate® code with realistic data for layers, and by measurements using synchrotron radiation.     

Phase transformation of natural titanite: An infrared,Raman spectroscopic,optical birefringence and X-ray diffraction study

The thermal behaviour of natural titanite has been studied using infrared and Raman spectroscopy, linear birefringence and synchrotron X-ray diffraction. Natural single crystals from Rauris, Austria (Fe 1.8%. Al 3.8%) were investigated and two additional samples from the Smithonian Institute Washington (Fe 2.8%, Al 0.5% and Fe 8.8%, Al 13.9%) served for IR and birefringence measurements. The coupled substitution of Fe and Al for Ti and OH and F for O leads to the formation of long ranging defect fields which are assumed to account for an increased density of antiphase boundaries. Infrared absorption spectra show increased bandwidths with increasing defect concentration. The phase transition near 500 K is clearly seen in the IR spectra of samples with low defect concentrations but not for those with high defect densities. X-ray diffraction shows strong anisotropic diffuse scattering in the Rauris sample leading to the average symmetry A2/a at room-temperature. A second anomaly at ca. 850 K was found by X-ray diffraction techniques using synchrotron radiation and by a break in the temperature evolution of the IR spectra.     

Nuclear diffraction experiments with grazing incidence antireflection films

The energy dependent reflectivity of grazing incidence antireflection (GIAR) films containing the Mößbauer isotope⁵⁷Fe has been measured with recoilless 14.4 keV radiation from a radioactive source. The reflectivity is influenced by oxide layers on the surface. Assisted by Mößbauer spectroscopy in transmission geometry and X-ray reflectivity measurements the hyperfine interaction parameters in the layers could be determined. In a nuclear diffraction experiment with synchrotron radiation a GIAR-film has been used as a filter. The diffracted beam was analysed by the (002) reflection of Yttrium Iron Garnet (YIG). The evaluation of the observed quantum beat pattern yielded the energy differential reflectivity of the GIAR-film in agreement with the results from the Mößbauer measurements.     

Optics and beamlines for high-pressure research at the european synchrotron radiation facility

Abstract

The European Synchrotron Radiation Facility (ESRF) is the first high-energy, high-brilliance synchrotron radiation source in operation today and it is ideally suited to high pressure research. White-beam and monochromatic diffraction techniques are being optimized in particular for structural studies of low-Z materials and poor scatterers generally, the best example being hydrogen single crystals at very high pressures. Most high pressure measurements are carried out on a versatile beamline equipped with a wiggler and an undulator. Focusing and image plates are used in all monochromatic angle-dispersive studies. The success of the high pressure programme has so far been achieved on a non-optimized beamline, but the next phase of the programme needs an optimized facility. A beamline is being constructed to fully exploit the intrinsic qualities of this unique source and insertion devices for high pressure studies. Its main design concepts are presented.     

第三代同步辐射光源X射线相干性测量研究

随着高性能第三代同步辐射光源的建成开放,基于X射线相干特性的实验方法得到了快速发展和广泛应用.作为一个典型的例子,X射线相位衬度成像已经成为常规的X射线实验方法并向用户开放.相干散射、相干衍射成像、光子关联谱等X射线实验方法正日益受到重视,在高空间分辨、时间分辨等研究领域已显示出其独特的优越性.因此,研究和测量第三代同步辐射的空间相干特性对进一步发展这些新的实验方法具有重要意义.基于Talbot自成像原理成功测量了上海光源X射线成像线站发射的X射线的空间相干长度,并进而测得了相应光源的空间尺度.光子能量为33.2 keV时,测得的X射线光束垂直方向空间相干长度为8.84μm,对应的光源尺寸为23μm,测量结果与理论分析相符.     

Nuclear Bragg diffraction using synchrotron radiation — A new method for hyperfine spectroscopy

Nuclear Bragg diffraction with synchrotron radiation as source will become a powerful new X-ray source in the Å-region. This source exceeds by now the brilliance of conventional Mössbauer sources giving hyperfine spectroscopy further momentum. As examples applications to yttrium iron garnel (YIG) and iron horate will be discussed.     

邻苯二甲酸氢钾(KAP)的同步辐射截面形貌术

本文叙述邻苯二甲酸氢钾(KAP)晶体内部不完整性(滑移位错等)的同步辐射截面形貌图的衬度研究工作。有关缺陷象衬度随波长增加而提高的实验事实同引用均匀畸变动力学的理论所引入的平均应变梯度参数β和βt_eff的理论计算结果,相当符合,它为应用同步辐射源来清晰显示单晶中有关缺陷,提供一个波长选择的依据。 关键词：     

高压下LiB3O5晶体-非晶体相变的研究

 采用X射线粉末衍射和同步辐射能散X射线衍射技术，对LiB₃O₅（LBO）晶体进行了压致非晶化相变的研究，压力达45.1 GPa。实验结果表明，LBO存在两个中间相变，压力分别为5 GPa和15.8 GPa。而当压力增加到25~31.6 GPa时，LBO出现非晶态，这个非晶化相变是不可逆的。     

Radiation—measurement complex of the Sirius synchrotron

The radiation-measurement complex associated with the Sirius synchrotron has been operating in the Scientific-Research Institute of Nuclear Physics of the S. M. Kirov Polytechnic Institute in Tomsk since 1985. Research on meson physics, channeling of high-energy electrons in crystals, new types of radiation, and applications of synchrotron radiation is carried out in this complex. The renovation of the synchrotron presently under way will allow these problems to be studied more effectively.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 5–7, June, 1991.     

同步辐射在古陶瓷研究中应用的现状和展望

概述了同步辐射光源的历史和优点,对同步辐射X射线荧光、X射线吸收精细结构、同步辐射X射线衍射等方法在古陶瓷工艺、产地等方面的应用现状进行了总结,并展望了同步辐射在古陶瓷研究中的应用前景.     

Diagnostics of gold-containing surgical-dressing materials with X-ray and synchrotron radiation

An analysis of biocompatible and antibacterial Au-gauze nanocomposites for medical purposes using X-ray and synchrotron radiation is conducted. The samples are produced by the modification of medical cotton gauze by Au organosol in isopropanol, which is synthesized via the metal-vapor method. The nanocomposites are examined with X-ray photoelectron spectroscopy, as well as with X-ray adsorption diffraction spectroscopy (EXAFS/XANES) and small-angle X-ray scattering using synchrotron radiation.     

Analysis of the phase composition of human kidney stones in model objects with the use of synchrotron radiation diffraction

The possibility of using synchrotron radiation for X-ray diffraction analysis of kidney stones directly in a human has been investigated. Experiments using a special phantom object imitating a human body have been performed. The experimental results obtained show that the significant thickness of the objects studied and the presence of liquids and biological polymers do not impose fundamental limitations on the possibility of in vivo synchrotron radiation diffraction analysis of human kidney stones.     

Synthesis of Novel Superhard Phases in the B-C-N System

Novel ternary diamond-like phases of the B-C-N system were synthesized at pressures up to 30 GPa and temperatures up to 3500 K by static and dynamic compression of graphite-like BN-C solid solutions. Structure and properties of these new phases were studied using X-ray diffraction with synchrotron radiation, analytical transmission electron microscopy (ATEM), electron energy loss spectroscopy (EELS), microhardness measurements and nanoindentation.