The plane grating and elliptical mirror: A new optical configuration for monochromators

A new optimal focussing kinematically simple two-element optics for plane grating monochromators is described. It will be used to monochromatise synchrotron radiation in the soft X-ray region.     

Improving Beamline X-ray Optics by Analyzing the Damage to Crystallographic Structure

The mission of the X-ray Characterization Laboratory in the X-ray Science Division (XSD) at the Advanced Photon Source (APS) is to support both the users and the Optics Fabrication Facility that produces high-performance optics for synchrotron X-ray beamlines. The Topography Test Unit (TTU) in the X-ray Lab has been successfully used to characterize diffracting crystals and test monochromators by quantifying residual surface stresses. This topographic method has also been adapted for testing standard X-ray mirrors, characterizing concave crystal optics and, in principle, can be used to visualize residual stresses on any optic made from single crystalline material.     

DISCO: a low‐energy multipurpose beamline at synchrotron SOLEIL

DISCO, a novel low‐energy beamline covering the spectrum range from the VUV to the visible, has received its first photons at the French synchrotron SOLEIL. In this article the DISCO design and concept of three experimental stations serving research communities in biology and chemistry are described. Emphasis has been put on high flux generation and preservation of polarization at variable energy resolutions. The three experiments include a completely new approach for microscopy and atmospheric pressure experiments as well as a `classical' synchrotron radiation circular dichroism station. Preliminary tests of the optical design and technical concept have been made. Theoretical predictions of the beam have been compared with the first images produced by the first photons originating from the large‐aperture bending‐magnet source. Results are also reported concerning the cold finger used to absorb hard X‐ray radiation in the central part of the synchrotron beam and to avoid heavy thermal load on the following optics. Wavelength selection using monochromators with different gratings for each experimental set‐up as well as beam propagation and conditioning throughout the optical system are detailed. First photons comply very well with the theoretical calculations.     

Simulation of Reciprocal Space Maps with the Use of Spectral Angular Diagrams in the Triple Crystal X-Ray Diffraction Scheme

An approach to the simulation of reciprocal space maps corresponding to the maps obtained experimentally by the triple crystal X-ray diffractometry (TXD) is proposed. A specific feature of the approach is the use of spectral angular distribution diagrams of X-ray radiation, which allows one to visualize the two-dimensional pattern of the spectral angular “composition” of an X-ray beam after its interaction with each element of the scheme and thus to take into account the contribution of the hardware function of the experimental setup. The algorithms developed allow calculations for a wide class of radiation sources (from an X‑ray tube with any material of the anode to a synchrotron radiation source) and X-ray optical elements (slits, X-ray mirrors of monochromators, and analyzers). The results of simulation are compared with the experimental data for dispersive diffraction geometry, which confirms the adequacy of the proposed approach and its applicability to the simulation of a diffraction pattern corresponding to a real experiment in the triple crystal scheme.     

How to do resonant nuclear experiments with synchrotron radiation

Summary The use of synchrotron radiation to excite low-lying nuclear resonances is a rapidly developing field showing great promise for hyperfine spectroscopy, phonon spectroscopy and kinetic studies, crystallography, and fundamental physics experiments. Recent technical advances in synchrotron sources, optics, and fast detectors have drastically increased signal rates and expanded the range of samples that can be studied. A typical experiment today uses a high-brightness synchrotron source having X-ray pulses well-separated in time, a meV-bandpass monochromator using perfect crystals of silicon or germanium, a sample containing resonant nuclei, and an avalanche photodiode timing detector. Both coherent and incoherent scattering can be observed; the coherent scattering is used for hyperfine spectroscopy and studies of diffraction interference phenomena, and the incoherent-scattering signal promises to be very useful for phonon spectroscopy and other studies of excitations in condensed systems. At this point seven nuclear isotopes have been used to resonantly scatter synchrotron radiation, but the number is rapidly increasing. Paper presented at the ICAME-95, Rimini 10–16 September 1995.     

Polarizer–analyzer optics

The principles behind the design and operation of polarizationbased optics for nuclear resonant scattering of synchrotron radiation are discussed. With perfect single crystals and collimated Xrays emitted from undulatorbased thirdgeneration synchrotron radiation sources, polarizationselective optics with a sensitivity of parts per billion can be obtained. A general approach to optical activity is introduced, and the polarization dependence of the index of refraction is calculated for nuclear forward scattering for a medium with unidirectional symmetry. Some recent experimental results are reviewed and future applications are discussed.     

Optics of nuclear diffraction with synchrotron radiation using α-57Fe2O3 single crystals

Nuclear Bragg diffraction of synchrotron radiation with -⁵⁷Fe₂O single crystals has achieved a counting rate as high as 20,000 cps at the accumulation ring AR of TRISTAN, KEK. The development of crystal optics using nuclear monochromators is described. Topographic images of -⁵⁷Fe₂0 nuclear diffraction has been observed.     

Feasibility of in‐line instruments for high‐resolution inelastic X‐ray scattering

Inelastic X‐ray scattering instruments in operation at third‐generation synchrotron radiation facilities are based on backreflections from perfect silicon crystals. This concept reaches back to the very beginnings of high‐energy‐resolution X‐ray spectroscopy and has several advantages but also some inherent drawbacks. In this paper an alternate path is investigated using a different concept, the `M⁴ instrument'. It consists of a combination of two in‐line high‐resolution monochromators, focusing mirrors and collimating mirrors. Design choices and performance estimates in comparison with existing conventional inelastic X‐ray scattering instruments are presented.     

光子晶体的光学特性与近场光学测量表征

光子晶体具有独特而优异的光学特性及广泛的应用前景。介绍了光子晶体的概念、应用、发展,着重讨论了光子晶体的光子禁带、光子局域以及其它光学特性。从近场光学的原理和实验技术出发阐述了近场光学测量表征光子晶体的方法,对于光子晶体的研究具有重要的意义。     

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：     

In Situ Measurements of Thermal Distortions in Synchrotron Optics under High Heat Load

Modern synchrotron X-ray sources produce many kilowatts of power, most of which are absorbed by the first optical elements of the monochromators. As a result, the monochromator crystal deforms (creating a heat bump), leading to severe degradation of the monochromator performance. This problem has been known for decades and various methods have been developed to lessen the effect of heat bumps by implementing various internal cooling methods for the crystal as well as using crystals with superior heat conductivity [1].     

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     

X-ray stations based on cylindrical zoom lenses for nanostructural investigations using synchrotron radiation

The main results of the development of X-ray stations are presented. These stations are intended to solve problems concerning the structural biology of tissues at a high time resolution with the help of synchrotron radiation (SR) generated by the VEPP-3 storage ring (Siberian center of SR, Novosibirsk) and the Siberia-2 storage ring (National Research Centre Kurchatov Institute and the centre of nano-, bio-, information, and cognitive sciences, Moscow). The issues of selecting the optical scheme and basic parameters of X-ray optical systems are discussed. Photographs of the original designs of the constructed equipment are given. A modular approach to designing experimental facilities based on self-contained units and methods of focusing a monochromatic SR beam in the required spectral range have been developed. The technique of X-ray beam focusing by means of optical zoom lenses has been implemented. Experimental results that illustrate the possibilities of the SR-beamline hardware used for X-ray diffraction investigation of different biological objects with the help of different recording systems are presented.     

全息聚合物弥散液晶器件电光特性的研究

研究了全息聚合物弥散液晶(HPDLC)器件的电光特性，研究了添加不同表面活性剂对聚合物界面对液晶的锚定能的影响机理，寻求到了低工作电压的实现方法. 分析了聚合物基体与液晶折射率不匹配性对器件对比度的影响，测量了HPDLC器件的响应时间和弛豫时间，得到了平均100μs的快速响应. 关键词： 全息聚合物弥散液晶 电光特性 表面活性剂 对比度 响应时间     

Polycapillary X-ray lens for the secondary focusing Beijing synchrotron radiation source

According to intensity distribution of the synchrotron radiation source focused by a toroidal mirror at the Beijing synchrotron radiation biological macromolecule station, theoretical modeling of the Beijing synchrotron radiation source is developed for capillary optics. Using this theoretical modeling, the influences of the configuration curve of the polycapillary X-ray lens on transmission efficiency and working distance are analyzed. The experimental results of the transmission efficiency and working distance at the biological macromolecule station are in good agreement with the theoretical results.     

Optics of broadband infrared diagnostics for accelerators

This review is devoted to an analysis of the properties and potentiality of optical synchrotron diagnostics, which is now a flexible means to study bunches (beams) of charged particles during their acceleration (storage) and interaction. The review briefly describes the history and main optical features of the devices used in experimental investigations of synchrotron radiation, beginning with the studies at the Lebedev Physical Institute. More elaborately considered is the infrared synchrotron method of diagnostics, which was developed at the Joint Institute for Nuclear Research and is based on optical methods developed at the Lebedev Physical Institute and Moscow State University. The main attention of the practical experiments is focused on designing, creating, and using special (broadband and long-focus) infrared optics, including mirrors, lenses, and heat-resistant windows. The merits and advantages of infrared diagnostics in comparison with optical diagnostics are shown in real examples.     

Using a standard sample to estimate the X‐ray wavelength of the 1W2A SAXS beamline at BSRF

This contribution describes a method for measuring diffraction peaks of a standard sample to estimate the incident X‐ray wavelength at the 1W2A SAXS beamline at BSRF. A simple simulation has been performed to establish the factors influencing the accuracy of the wavelength measurement. Appropriate measurement conditions and error control measures are presented. An actual experimental example further verifies the effectiveness of the simulation. This method is particularly suitable for synchrotron radiation beamlines using bent triangular crystal monochromators.     

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.     

High-time resolution radiographic technique for studying nanostructures with the use of synchrotron radiation

A high-time resolution radiographic technique for studying nanostructures using synchrotron radiation is described. A new modification of the methods, which makes it possible to perform large-scale X-ray diffraction analysis of structures of organic crystals, is proposed. X-ray diffraction patterns obtained in test experiments on a number of biological samples are presented.     

部分相干同步辐射照射下光栅分数塔尔博特效应

基于高斯谢尔光束的相干模式分解理论和波动光学,建立了部分相干同步辐射硬X射线光束通过光学器件的传播模型。模拟了微聚焦X射线光束照射下光栅的分数塔尔博特效应,得到了聚焦光束的光强分布和相干特性变化,并分析了散焦光束入射下的光栅自成像。然后通过模拟准直光束入射下的光栅塔尔博特效应,得到了不同传播距离处自成像条纹的变化情况,分析了影响光栅自成像条纹形状的因素。通过光栅衍射条纹测量同步辐射相干度,发现对矩形相位光栅来说,应该对衍射图样进行傅里叶分解,求出各级傅里叶系数随传播距离的变化曲线,从而得到入射光束相干特性。