北京同步辐射装置3B3前端区和光束线输出特性诊断

北京同步辐射装置(BSRF)新建3B3光束线通过重新安装、准直和在线调试, 其光学输出特性均达到或超出原设计指标, 光通量达到7×10¹⁰phs/s(100mA下), 能量分辨本领(E/ΛE)达到5000(3.206keV). 介绍了前端区和光束线输出光学特性的诊断方法和光束线在线调试过程, 给出了输出特性的测试结果. 分析了BPM与荧光靶在调试过程中所起的作用及局限性.     

关于wiggler长波自发辐射的理论分析与数值计算

电子通过wiggler产生的辐射，除了短波辐射在轴线附近也有较强的长波辐射，在与轴线夹 角1/γ处达到最大.推导出wiggler长波辐射公式，理论分析了这种辐射的特点，并且将 理论分析的结果与数值计算的结果进行了比较.对在红外波长范围内电子束通过弯转磁铁和wiggler时产生的辐射强度和光通量作了计算，结果表明wiggler下的辐射强度和光通量均强 于弯转磁铁.比较了弯转磁铁的边沿辐射、波荡器的渡越辐射和wiggler长波辐射，表明wigg ler在红外波长范围辐射的性能最优. 关键词： wiggler 波荡器 弯转磁铁 长波辐射     

辐射与发光

光辐射与辐射源O432.12006020822BSRF-3B3前端区和光束线输出特性诊断=Diagnosis ofthe output characteristics of BSRF-3B3front end andbeamline[刊,中]/赵佳(中科院高能物理所.北京(100049)),崔明启…∥高能物理与核物理.—2005,29(12).—1203-1209北京同步辐射装置(BSRF)新建3B3光束线通过重新安装、准直和在线调试,其光学输出特性均达到或超出原设计指标,光通量达到7×1010phs/s(100mA下),能量分辨本领(E/ΔE)达到5000(3.206keV)。介绍了前端区和光束线输出光学特性的诊断方法和光束线在线调试过程,给出了输出特性的测试结果…     

漫话插入元件

 同步辐射是本世纪70年代发展起来的一种新型光源,具有亮度高、波长（从红外到X光波段）连续可调、准直性好、完全确定的偏振度、洁净的工作环境(优于10^-9的真空度)、快速而精确的光脉冲时间结构等一系列优点,在物理、化学、生物、医学、农业、材料科学、冶金、能源、地矿、微电子、化工等多学科领域有着广泛的应用.然而,早年用于高能物理实验研究的正、负电子对撞机所产生的同步辐射虽然远远优于其它辐射光源,但从其本身的条件考虑,仍然是不大理想的.因为这样产生的同步辐射是由储存环中的弯转磁铁产生的,利用弯铁作为同步辐射光源具有一定的局限性首先,对弯转磁铁来说,其主要作用是维持储存环中电子束流在封闭的真空管道内循环,应满足储存环上的物理要求,因而同步辐射仅是其一种副产品.由下式可知:B[T]ρ[m]=3.336E[GeV].式中B为弯铁磁场,ρ为弯转半径.     

高能光源增强器束流横向尺寸测量系统设计

高能同步辐射光源的增强器将直线加速器注入的束流加速到储存环所需的能量,为储存环提供高品质的电子束。为了对增强器的束流横向截面尺寸、发射度及能散进行测量,设计了两条可见光-紫外波段的束测光束线。两条光束线分别选取无色散和色散较大的两处弯铁位置作为光源点,使用两套同步光成像系统来监测光源点的束流截面尺寸,并计算束流发射度及能散。介绍了同步光引出真空室及光学成像系统,对影响成像质量的空间分辨率进行了分析,并针对升能过程中不同能量下束流光斑变化的测量进行了设计。     

北京同步辐射装置3B1B光束线和生物光谱实验站

３Ｂ１Ｂ光束线是北京同步辐射装置（ＢＳＲＦ）３Ｂ１光刻束线的一条分支束线，其光路和布局如图１所示．从北京正负电子对撞（ＢＥＰＣ）储存环３Ｂ１弯转磁铁处引出的同步辐射水平线偏振光，光源水平方向发散角为±３．７５ｍｒａｄ，竖直方向发散角为±０．２ｍｒａｄ，在距源１３．５ｍ处由一块柱面准直扫描镜Ｍ１反射后，水平方向的汇聚角为±１．２５ｍｒａｄ，竖直方向发散角不变．在距源２４ｍ处，有一块可升降的旋转抛物面反射镜Ｍ２．它降下时，光通过供其他实验站使用；升起时，将光反射聚焦于上方０．６ｍ处生物光学实验站光栅…     

紧凑型LED配光设计中光源模型可靠性研究

针对现有LED光源建模适用条件及可靠性不确定性的问题,对紧凑型LED配光设计中光源建模可靠性进行了研究.通过优化设计具有不同透镜光源直径比模型的方法,对点光源、表面光源、ray文件光源三种建模方式在系统中的差异进行分析对比.整体设计以ray文件光源模型为基准,以常规紧凑型全反射式透镜为二次配光元件,对不同透镜光源直径比(光束角分别为±15°、±10°、±5°)的光学系统进行优化设计和分析计算.结果表明:在能量利用率误差为±2%的范围内,光束角为±15°,透镜光源直径比大于36∶2时,表面光源建模可代替ray文件光源建模;光束角±10°,透镜光源直径比为44∶2时,表面光源建模可代替ray光源建模;光束角为±5°,透镜光源直径比为82∶2时,表面光源建模可代替ray文件光源建模.但是在±2%误差范围内,点光源无论在何种透镜光源直径比,任何光束角下均不能代替ray文件光源.这一结果为紧凑型系统设计中光源模拟提供了依据,同时解决了采用ray文件光源建模进行辅助优化设计耗时较长的问题,为相关研究提供了参照依据.     

关于光学速调管长波长辐射的分析

由波荡器渡越辐射公式和电子通过wiggler边界产生的长波长辐射公式, 解析给出了电子通过光学速调管时产生的长波长辐射公式. 根据基本的电动力学公式数值计算出合肥同步辐射装置光学速调管的长波辐射, 并将其结果与解析公式的结果进行比较. 计算合肥同步辐射装置的光学速调管和弯转磁铁在红外波段范围内辐射的强度和通量, 表明光学速调管有很好的性能.本文说明, 光学速调管不但可以用来进行相干谐波的试验研究, 也可以兼用作储存环中的红外辐射光源.     

同步辐射X射线成像光束线劳厄双晶单色器设计

上海光源X射线成像光束线采用多极扭摆器(wiggler)作为辐射光源, 提出一种劳厄双弯晶单色器的设计方案. 计算结果显示, 可获得固定出口的平行单色光束, 能量调谐范围覆盖19—120keV, 在33keV时, 输出光子通量及通量密度分别为1.9×10¹³phs/s和3.8×10¹⁰phs/s/mm². 分析了劳厄晶体的聚焦及单色化性能, 计算了输出光子通量及单色器的热负载情况. 与传统的双平晶方案相比, 本设计在获得高通量和解决热负载等方面有明显的优越性, 并能有效控制热形变.     

有限宽光束在生物组织中传输的蒙特卡罗方法

基于光在生物组织中的传输理论,研究有限宽光束在生物组织中的传输特性.利用入射光强与格林函数进行卷积计算,推导了有限宽光束在圆柱坐标系下的光传输过程,给出了有限宽光束的光传输方程.以高斯光源和平圆光源为例,进一步给出了两种光源的有限宽光束在生物组织中的光传输方程.介绍了Monte Carlo方法原理及模拟光在多层生物组织中的传输过程.给出了典型三层生物组织的散射系数、吸收系数和折射率等光学参数.利用Monte Carlo方法模拟了有限宽光束在三层生物组织中的传输特性,对比研究了高斯光源和平圆光源有限宽光束在三层生物组织传输时光学参数漫透射率、漫反射率和光能流率的变化规律.这些参数的变化规律可为光在生物组织传输的实际应用提供理论指导.     

Calculation of Transmitted Efficiency and Output Characteristics for Beijing Synchrotron Radiation Facility (BSRF) 3B3 Beamline

Based on the radiation characteristics of the bend magnet source, the output characteristics of the BSRF-3B3 beamline was analyzed and discussed. The result is the foundation of adjustment and diagnosis of the beamline. A calculation model is provided to analyze characteristics of beamlines attached to bend magnet sources.     

Infrared facility at the Canadian light source

The Canadian Light Source (CLS) is constructing two beamlines for Infrared Spectroscopy using synchrotron radiation (IRSR). One will supply mid-Infrared (2–25 μ) light to a Fourier Transform Infrared (FTIR) spectrometer and microscope for biological applications. The second will have a high resolution FTIR spectrometer for gas-phase and surface spectroscopy in the far-Infrared (beyond 25 μ). The Infrared beamlines will use dipole bending magnet radiation from a special bend magnet port design which provides a 50 mrad square acceptance. Issues with the first mirror and photon mask design, as well as the beamline layout and features are discussed.     

Upgrading design of the 3B1A beamline for x-ray nanometre lithography of microelectronic devices at BSRF

Beijing Synchrotron Radiation Facility is a partly dedicated synchrotron radiation source operated in either parasitic or dedicated mode. The 3B1A beamline, extracted from a bending magnet, was originally designed as a soft x-ray beamline for submicro x-ray lithography with critical lateral size just below 1μm in 1988 and no change has been made since it was built. But later the required resolution of x-ray lithography has changed from sub-micrometre to the nanometre in the critical lateral size. This beamline can longer more meet the requirement for x-ray nano lithography and has to be modified to fit the purpose. To upgrade the design of the 3B1A beamline for x-ray nano lithography, a mirror is used to reflect and scan the x-ray beam for the nano lithography station, but the mirror's grazing angle is changed to 27.9mrad in the vertical direction, and the convex curve needs to be modified to fit the change; the tiny change of mirror scanning angle is firstly considered to improve the uniformity of the x-ray spot on the wafer by controlling the convex curve.     

Energy‐dispersive X‐ray absorption spectroscopy at LNLS: investigation on strongly correlated metal oxides

An energy‐dispersive X‐ray absorption spectroscopy beamline mainly dedicated to X‐ray magnetic circular dichroism (XMCD) and material science under extreme conditions has been implemented in a bending‐magnet port at the Brazilian Synchrotron Light Laboratory. Here the beamline technical characteristics are described, including the most important aspects of the mechanics, optical elements and detection set‐up. The beamline performance is then illustrated through two case studies on strongly correlated transition metal oxides: an XMCD insight into the modifications of the magnetic properties of Cr‐doped manganites and the structural deformation in nickel perovskites under high applied pressure.     

08B1‐1: an automated beamline for macromolecular crystallography experiments at the Canadian Light Source

Beamline 08B1‐1 is a recently commissioned bending‐magnet beamline at the Canadian Light Source. The beamline is designed for automation and remote access. Together with the undulator‐based beamline 08ID‐1, they constitute the Canadian Macromolecular Crystallography Facility. This paper describes the design, specifications, hardware and software of beamline 08B1‐1. A few scientific results using data obtained at the beamline will be highlighted.     

Optimized IR synchrotron beamline design

Synchrotron infrared beamlines are powerful tools on which to perform spectroscopy on microscopic length scales but require working with large bending‐magnet source apertures in order to provide intense photon beams to the experiments. Many infrared beamlines use a single toroidal‐shaped mirror to focus the source emission which generates, for large apertures, beams with significant geometrical aberrations resulting from the shape of the source and the beamline optics. In this paper, an optical layout optimized for synchrotron infrared beamlines, that removes almost totally the geometrical aberrations of the source, is presented and analyzed. This layout is already operational on the IR beamline of the Brazilian synchrotron. An infrared beamline design based on a SOLEIL bending‐magnet source is given as an example, which could be useful for future IR beamline improvements at this facility.     

A new optical scheme for large‐extraction small‐aberration vacuum‐ultraviolet synchrotron radiation beamlines

Vacuum‐ultraviolet radiation delivered by bending‐magnet sources is used at numerous synchrotron radiation facilities worldwide. As bending‐magnet radiation is inherently much less collimated compared with undulator sources, the generation of high‐quality intense bending‐magnet vacuum‐ultraviolet photon beams is extremely demanding in terms of the optical layout due to the necessary larger collection apertures. In this article, an optimized optical layout which takes into account both the optical and electron beam properties is proposed. This layout delivers an improved beam emittance of over one order of magnitude compared with existing vacuum‐ultraviolet bending‐magnet beamlines that, up to now, do not take into account electron beam effects. The arrangement is made of two dedicated mirrors, a cylindrical and a cone‐shaped one, that focus independently both the horizontal and the vertical emission of a bending‐magnet source, respectively, and has been already successfully applied in the construction of the infrared beamline at the Brazilian synchrotron. Using this scheme, two vacuum‐ultraviolet beamline designs based on a SOLEIL synchrotron bending‐magnet source are proposed and analysed. They would be useful for future upgrades to the DISCO beamline at SOLEIL and could be readily implemented at other synchrotron radiation facilities.     

Simultaneous XAFS measurements of multiple samples

A four‐channel ionization chamber has been designed, constructed and tested. This ionization chamber allows X‐ray absorption spectra to be collected in transmission from up to four samples simultaneously. This results in spectra that are free of systematic uncertainty in relative energy alignment introduced by scan‐to‐scan stability of the monochromator or of numerical uncertainty associated with a post‐processing alignment algorithm, allowing, in a single shot, an absolute measure of edge shift between four samples of different valence. As four samples can be measured in parallel, the time expended over the course of an experiment to cycle the measurement environment between its rest state and the measurement condition is substantially reduced. The ionization chamber is simple in design and could be implemented at virtually any XAFS beamline with a horizontal fan of radiation such as that provided by a bend magnet or wiggler.     

Energy-dispersive X-ray diffraction beamline at Indus-2 synchrotron source

An energy-dispersive X-ray diffraction beamline has been designed, developed and commissioned at BL-11 bending magnet port of the Indian synchrotron source, Indus-2. The performance of this beamline has been benchmarked by measuring diffraction patterns from various elemental metals and standard inorganic powdered samples. A few recent high-pressure investigations are presented to demonstrate the capabilities of the beamline.     

Focusing,collimation and flux throughput at the IMCA‐CAT bending‐magnet beamline at the Advanced Photon Source

The IMCA‐CAT bending‐magnet beamline was upgraded with a collimating mirror in order to achieve the energy resolution required to conduct high‐quality multi‐ and single‐wavelength anomalous diffraction (MAD/SAD) experiments without sacrificing beamline flux throughput. Following the upgrade, the bending‐magnet beamline achieves a flux of 8 × 10¹¹ photons s^?1 at 1 Å wavelength, at a beamline aperture of 1.5 mrad (horizontal) × 86 µrad (vertical), with energy resolution (limited mostly by the intrinsic resolution of the monochromator optics) δE/E = 1.5 × 10^?4 (at 10 kV). The beamline operates in a dynamic range of 7.5–17.5 keV and delivers to the sample focused beam of size (FWHM) 240 µm (horizontally) × 160 µm (vertically). The performance of the 17‐BM beamline optics and its deviation from ideally shaped optics is evaluated in the context of the requirements imposed by the needs of protein crystallography experiments. An assessment of flux losses is given in relation to the (geometric) properties of major beamline components.