Use of the Advanced Photon Source and Center for Nanoscale Materials, Office of Science User Facilities operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. We acknowledge Dr. Han Wen, NHLBI / National Institutes of Health, Bethesda, MD 20892, USA, for many helpful suggestions during the data processing.

1.实验计划<ol><li>确定同步加速器光束线。与束线科学家找到实验在该束线的适当性。 注:本稿件报道实验是在1 BM-B光束线，这是致力于光学和探测器的检测，APS的XSD下进行。 </li><li>提交用户的建议和梁的请求。 </li><li>制定出实验的细节与束线科学家和指定所需的仪器，包括用于光栅和检测器对齐，二维检测器（CCD或CMOS），覆盖所述检测器之间所需要的最小和最远的距离长平移台电动平台相位光栅。 </li><li>按照在相关网站提供的说明制备用于光束的时间。完成安全培训和必要的实验安全性评估的形式。 </li></ol> 2.二维棋盘博士的制备ASE光栅<ol><li>确定光栅， 对 ，这是关系到干涉图案， 对θ的期间，沿不同宽度方向角θ的周期。可见性值，Vθ（d）中 ，沿不同θ角的干涉的振荡作为光栅到检测器的距离的函数，D。 在距离的2-D棋盘π/ 2的相位光栅，Vθ（ 四 ）的峰， <img alt="式（1）" src="/files/ftp_upload/53025/53025eq1.jpg" /> 其中n = 1，2，3 ...，λ的光子波长。干涉图案具有p个θ= P /√2沿着正方形块的对角方向和一个周期p 的θ=π/ 2沿正方形块的边缘的特征周期。 P的选择，因此，依赖于以下标准。 </li><li>请确保至少有几Vθ（D）的峰值是最大光栅到探测器距离内，或实验站的空间限制，D 最大 。为了满足D N，θ&lt;D 最大 ，它遵循 <img alt="公式（2）" src="/files/ftp_upload/53025/53025eq2.jpg" /> 对于n = 5，D 最大 =1μm时，λ= 0.06888纳米（18千电子伏），它赋予pθ&lt;3.9微米。 </li><li> D中最大 ，确保在最大距离D N在Vθ（ 四 ）峰的高度，θ小于那头Vθ（ 四 ）在d 1峰值的系数γ，θ以有一个准确的高斯衰减函数拟合。因此，γ= Vθ，N（D）/Vθ，如图1（d），它是第 n 个峰的可视性于第一峰的比值。对于在用相干长度高斯强度分布的X射线源，ξθ，一π/ 2的相位光栅需要的期间，以满足 <img alt="公式3" src="/files/ftp_upload/53025/53025eq3.jpg" /> 例如，用γ= 10％，ξθ= 5微米及以上的参数，它赋予pθ&gt; 2.4微米。 </li><li>确保该干涉图案， 对θ，的周期是通过选择正确的检测器系统比检测器的空间分辨率大几倍。 </li><li>确定的厚度，T为，φ相移所需的光栅，在X射线光子波长λ，使用 <img alt="公式4" src="/files/ftp_upload/53025/53025eq4.jpg" /> 其中δ是相移材料的折射率递减。例如，对于金的折射率递减是9.7×10 18千电子伏-6。非盟厚度φ=π/ 2相位光栅因此是1.8微米。 </li><li>制造的相位通过电镀金成图案化聚合物模具上的氮化硅光栅（ 的 Si 3 N 4）的窗口。 注:制备氮化硅（Si 3 N 4）窗基板和制造中的光栅结构的方法如下。 <ol><li>通过首先释放的 Si 3 N 4膜以形成X射线透明窗准备基板。 </li><li>获得具有低应力（&lt;250兆帕） 的 Si 3 N 4沉积在从一个供应商提供的晶片的两侧硅（Si）晶片。 </li><li>装载晶片到磁控溅射淀积系统淀积Cr和Au充当电镀基。 </li><li>铬次的存款5纳米烯在晶片的一侧上的Au为30nm，按照生产商的指示。 注:从系统制造商的沉积过程将包括诸如沉积速率的信息。 </li><li>卸载从沉积工具晶圆。使用沉积有Cr和Au为光栅制造晶片的侧面。 </li><li>确定光栅的总大小，然后设计一个光刻掩模图案膜稍大。使用设计通过从供应商处购买来获取光刻掩模或制造的光刻掩模。 </li><li>关于在没有Cr和Au涂层的晶片的背面侧旋光致抗蚀剂的3微米厚的一层。暴露利用设计光刻掩模用紫外线光刻工具的抗蚀剂20秒。显影曝光在含水碱性显影剂溶液抗蚀30秒，然后用去离子水淋洗并干燥用流动的 N 2。 </li><li>装载晶片进入活性离子蚀刻（RIE）工具瓦特第i个图案化光致抗蚀剂所面临的腔室。使用CF 4的等离子体来蚀刻暴露的 Si 3 N 4以下工具的指令。 </li><li>疏散蚀刻室和输入蚀刻配方为RIE工具。运行配方直到在Si 3 N 4层被完全蚀刻和Si层在图案曝光。 </li><li>通过浸没入约8小时30％的KOH溶液中加热至80℃蚀刻在晶片背面露出的Si。蚀刻速率是大约使用所述配方为75μm/小时。 </li><li>硅蚀刻完成后，用去离子水冲洗和干燥用流动的 N 2。样品是准备光栅制造。 </li></ol></li><li>制造用于相使用以下步骤光栅电镀模具。 <ol><li>设计方棋盘光栅图案与补偿模式由100-250纳米的减少暴露的方形图案大小偏置。包括围绕GRAT一个&gt; 50微米的宽边框ING模式的厚度确认以后的进程。 </li><li>加载样品放入抗蚀旋涂器和沉积聚（甲基丙烯酸甲酯）（PMMA）正型抗蚀剂在样品的光栅侧的解决方案。运行抗蚀剂旋涂机，以形成2〜3.5微米的取决于期望的最终光栅厚度厚的抗蚀膜。 注:对纺丝速度与膜厚度信息自旋曲线由聚甲基丙烯酸甲酯溶液供应商提供或可凭经验确定。 </li><li>装载晶片到100千电子伏的电子束光刻系统。 </li><li>用大电流接触超过10 nA的更大的校准曝光的工具。 </li><li>露出用100千电子伏的电子束光刻工具来创建光栅图形，其中曝光区域将在显影工序中除去的PMMA抗蚀剂。根据抗蚀剂厚度使用的1,100-1,250μC/ cm 2的曝光剂量范围。 </li><li>卸载从工具的样本。 </li><li>发展曝光的光刻胶通过在7浸没:3（体积）异丙醇（IPA）:30-40秒，轻轻旋转去离子水的溶液。用IPA冲洗，然后用流动的 N 2干燥。确保聚甲基丙烯酸甲酯，通过用光学显微镜观察露出面积充分的发展。 </li><li>加载样品与朝向腔室的PMMA图案的RIE工具。 </li><li>疏散蚀刻室和输入除渣蚀刻配方到RIE工具。该除渣工艺是短（&lt;30秒），O 2等离子蚀刻基础，从暴露的光栅区域除去残留的PMMA。 </li></ol></li><li>通过电镀成使用以下步骤的制造模具完成的Au光栅。 <ol><li>通过扫描轮廓的探头横跨包括了厚度确认帧确保电镀模具厚度。 </li><li>淹没样品进入该Au-亚硫酸盐电镀液加热到40℃。电镀的设置是由充满ELE烧杯ctroplating溶液，以恒定电流DC电源，和一个铂网状阳极。 </li><li>通过在曝光图案计算的露出的Au确定样品的电镀区域，然后计算出所需的电流密度，这是用于设置沉积速率主可变电流。 </li><li>计算电镀时间使用由施加的电流密度确定的镀覆速率，以达到所需的光栅厚度。 </li><li>打开直流电源施加在样品上所确定的当前，作为阴极和板为大约一半的总镀覆时间。 </li><li>测量使用在步骤2.8.1中使用的方法相同的方法的电镀厚度。 </li><li>打开直流电源到电镀金入PMMA模具和电镀到所需的光栅厚度，考虑到在步骤2.8.6测定的镀高度。 </li></ol></li><li>通过浸入样品中取出用温水溶剂中的聚合物模具。然后用光学检查升显微镜和扫描电子显微镜（SEM）确认光栅周期，占空比和光栅厚度。 注意:有两台2-D棋盘相位光栅（一个用于实验，一个作为备用）准备好了，过几天在实验开始前。 </li></ol> 3.实验设置和校正的同步加速器设施<ol><li>要求束线科学家到X射线束的能量或波长设置为所需的值相匹配的相位光栅。在APS 1-BM光束线经常使用X射线能量是6和28千电子伏之间。在这种情况下，调光子能量至18千电子伏。 </li><li>选择用于检测器系统所需要的物镜。在这里，使用Coolsnap HQ2 CCD探测器，具有6.45×6.45微米2的像素尺寸的1392×1,040像素的成像。要解决最小的干涉图案，使用EC计划NEOFLUAR 10×目标。检测器系统的有效像素尺寸包括放大微观目标的效果是这样0.64微米。所估计的空间分辨率为约2微米，这主要是由于在检测器系统的点扩散函数。 </li><li>设置粗糙聚焦检测器系统的，将闪烁器（镥钇oxyorthosilicate，150微米厚）在从透镜的"工作距离"（〜5.2毫米用于所使用的系统）。首先，通过监控下的"连续模式"为闪烁位置获得的图像是使用微微电动调节设置在环境光的聚焦。 </li><li>移动的2-D检测器进入X射线束，利用垂直和水平阶段对齐检测器的光束中心的中心。 </li><li>放置一个&#39;相样本"，例如一块泡沫塑料，进入X射线束。执行精细通过观察从相位样本的散射图案和调节该闪烁体的位置，直到最高的图像清晰度聚焦在检测器系统的。 </li> &lt;/ OL&gt; 4.执行一致性测量<ol><li>放置2维棋盘光栅进入X射线束，其中的光束的相干性是被测定。在这种情况下，它是在从弯曲磁体源34米。 </li><li>调整的2-D棋盘相位光栅垂直于X射线束传播方向的平面。 </li><li>通过使用电动平台和观察下检测器连续模式获取的图像居中光栅的X射线束。 </li><li>绕在X射线束传播方向（y），以使棋盘图案的对角线方向是沿着所需横梁方向上的光栅。在这种情况下，对齐棋盘中的光束的水平和垂直方向的对角方向（优选的测量方向）。微调其它两个轴（x和z）内的光栅的旋转，以确保其垂直于X射线光束，这是通过最大化在水平和垂直两个方向上的干涉周期来实现的。 </li><li>将尽可能接近实际可能的相位沿着光束传播方向光栅探测器系统。在这项研究中，使用43毫米的距离。 </li><li>计算干涉图案的最小周期。该π/ 2棋盘具有周期p光栅= 4.8微米会分别产生与对θ的干涉图案=沿对角线与棋盘图案的非对角方向3.4微米和pθ= 2.4微米（最小周期）。估计需要在两者之间由公式鉴于第五θ（D）峰值位置（1），得到一个平滑的曲线的数据点的数量。 </li><li>选择合适的曝光时间为每个干涉图，在这种情况下，四秒钟。 </li><li>用相同的曝光时间（ 例如 ，4秒）在记录干涉图不同的光栅到检测器的距离。选择基于所述光束的强度级的曝光时间。从最小光栅到检测器的距离（43 MM）开始，移动由小间隔的X射线的下游检测器（测定10毫米根据步骤4.6）和记录在每个检测器的位置的干涉直到最大可能grating-到检测器的距离（750毫米）。 </li><li>获得具有相同的曝光时间（4秒）暗帧图像，但关闭X射线束，并保持所有其他实验条件相同。 </li></ol> 5.数据分析注:目前可用于数据分析没有标准的软件。 <ol><li>使用选定的图像处理程序，读出的暗帧图像（S）和数据映像中。减去（平均）暗帧图像校正数据镜像。 </li><li>傅立叶变换暗帧校正图像，从而产生可见谐波峰值在水平（52 = 0°），垂直（θ= 90°），以及θ= 45°，θ= 135°的方向。 </li><li>产量为0 级峰值为中心的0 阶谐波图像。图像的长度和宽度分别等于0 级和沿水平和垂直方向1 次顺序峰之间的距离。同样地，获得的沿横向方向的相同的长度和宽度的1 次高次谐波的图像。 </li><li>傅立叶逆变换（IFT）裁剪的谐波图像。从第1 次的IFT图像的振幅的平均值的比率沿任何横向方向上，从第 0次谐波图象的IFT图像的次谐波图像给出沿该方向的可见性。 注意，此过程是有效的，如果所测量的干涉存在少数的高频分量。否则，可以使用的CORRE傅立叶应的谐振峰强度从5.4步，而不是变换的图像。由于光束的发散，谐波峰值位置将在不同的光栅到检测器的距离逐渐变化。因此，修正为p&#39;在每个距离θ或需要一个峰发现过程。 </li><li>在不同的光栅到检测器的距离的所有所测量的图像重复步骤5.1-5.4和保存各图像的可见度值。 </li><li>绘制能见度Vθ（d）作为光栅到检测器的距离的函数。在Vθ（ 四 ）的峰确定的数据点。需要注意的是完整的曲线，测定只是为了更好地确定由公式（1）给定的峰值位置。每个峰的两侧手动选择峰值数据点以及相邻的数据点。 </li><li>绘制高斯拟合函数为所选数据点。提取标准偏差，σθ，日的Ë高斯函数拟合。 </li><li>获得横向相干长度，ξθ，用 <img alt="公式5" src="/files/ftp_upload/53025/53025eq5.jpg" /></li></ol>

<ol>
	<li>Als-Nielsen, J., McMorrow, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Elements of Modern X-ray Physics. , (2011).</li><li>Born, M., Wolf, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Principle of Optics. , (1999).</li><li>Lin, J. J. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+the+Spatial+Coherence+Function+of+Undulator+Radiation+using+a+Phase+Mask.">Measurement of the Spatial Coherence Function of Undulator Radiation using a Phase Mask.</a> Phys. Rev. Lett. 90 (7), 074801 (2003).</li><li>Cloetens, P., Guigay, J. P., De Martino, C., Baruchel, J., Schlenker, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fractional+Talbot+imaging+of+phase+gratings+with+hard+X-rays.">Fractional Talbot imaging of phase gratings with hard X-rays.</a> Opt. Lett. 22 (14), 1059-1061 (1997).</li><li>Guigay, J. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+partial+Talbot+effect+and+its+use+in+measuring+the+coherence+of+synchrotron+X-rays.">The partial Talbot effect and its use in measuring the coherence of synchrotron X-rays.</a> J. Synchrotron Rad. 11, 476-482 (2004).</li><li>Kluender, R., Masiello, F., Vaerenbergh, P. V., H&#228;rtwig, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+the+spatial+coherence+of+synchrotron+beams+using+the+Talbot+effect.">Measurement of the spatial coherence of synchrotron beams using the Talbot effect.</a> Phys. Status Solidi A. 206 (8), 1842-1845 (2009).</li><li>Pfeiffer, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shearing+Interferometer+for+Quantifying+the+Coherence+of+Hard+X-Ray+Beams.">Shearing Interferometer for Quantifying the Coherence of Hard X-Ray Beams.</a> Phys. Rev. Lett. 94 (1-4), 164801 (2005).</li><li>Marathe, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+transverse+coherence+of+x-ray+beam+with+2-D+phase+grating+interferometer.">Probing transverse coherence of x-ray beam with 2-D phase grating interferometer.</a> Opt. Express. 22 (12), 14041-14053 (2014).</li><li>Shi, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circular+grating+interferometer+for+mapping+transverse+coherence+area+of+X-ray+beams.">Circular grating interferometer for mapping transverse coherence area of X-ray beams.</a> Appl. Phys. Lett. 105 (1-6), 041116 (2014).</li><li>Zanette, I., David, C., Rutishauser, S., Weitkamp, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=2D+grating+simulation+for+X-ray+phase-contrast+and+dark-field+imaging+with+a+Talbot+interferometer.">2D grating simulation for X-ray phase-contrast and dark-field imaging with a Talbot interferometer.</a> , 73-79 (2010).</li></ol>

The authors have nothing to disclose.

图5示出沿所有四个方向的估计横向相干长度。显然，90°的方向上具有较高的ξ相对于0°方向θ。由于束线光学对在光栅的相对位置的光束相干性的影响可以忽略，所测量的相干区域是成反比的源尺寸的区域。所呈现的X射线束相干测量技术准确映射这可以示出为沿垂直方向（参照图5）其长轴的椭圆。要注意的是与周围的自成像距离的自成像距离或几个图象的充分表征光栅仅干涉，需要得到的相干长度是很重要的。一个这种技术的局限性是，在特定的能量横向相干性的测量需要的能量优化的光栅。 在TEchnique依赖于光栅和检测器之间的距离的精确测量，特别是，当使用光栅具有较小周期和在较低能量，例如，在8千电子伏进行实验。沿对角线棋盘光栅的方形块时，可见度曲线上的光栅周期的不匹配的影响是可以忽略不计，并且获得较高的能见度。因此，光栅取向的选择取决于沿其横向相干性测量需要执行的优选方向。 相比于参考图3描述的技术中，所提出的方法不需要任何形状模型的假设，获得CCF曲线。单相代替光栅的双光栅干涉仪系统7（包括一个相位光栅和一个振幅光栅，它的制造是为硬X射线应用挑战）。使用单一的光栅使快速安装和对准，同时提供相同的相干信息作为双光栅干涉仪系统。超越参考文献4-6所描述的工作，单光栅干涉映射同时沿四个不同方向的相干长度。该技术也能够在小面积解决该光束波前的相干局部变化的。 通过该技术所提供的X射线束的横向相干信息不仅用于设计实验，而且作为用于数据分析的先验知识很重要的。由于同步加速器和XFEL源的一致性亮度不断提高，以保持这种光源的相干所需的X射线光学已进行评估，并在这里描述的技术可用于测量（本地）束波前横向连贯性的绝佳工具。

第三代硬X射线同步辐射光源，如ANL，莱蒙特，IL，USA（http://www.aps.anl.gov）的APS，都对X射线科学的发展影响巨大。的同步加速器辐射源产生的电磁辐射的光谱，从红外线到的X射线的波长，当带电粒子，例如电子，是由以光速附近移动中的圆形轨道。这些来源具有非常独特的性能，如高亮度，脉冲和皮秒定时结构，以及大的空间和时间相干性。 X射线束的空间相干性是在第三和第四代同步源的一个重要参数和实验利用这个特性，在过去的二十年1急剧增加的数量。这些来源，如计划多弯曲消色差透镜（MBA）的晶格为APS储存环的未来的升级，将显着增加光束相干通量（HTTP://www.aps.anl.gov/Upgrade/）。的X射线束可使用一个晶体单色实现更高的时间相干性来调节。的同步加速器源的横向相干性比的，因为从源到实验站的低的电子束发射度和长传播距离的基于实验室X射线源显著更高。 通常情况下，杨氏双针孔或双缝实验用于通过干涉条纹2的可见性的检查来测量光束的空间相干性。以获得完整的复相干函数（CCF），需要与放置在与各分离，这一点，特别是对于硬X射线，麻烦和不实际的不同位置上的两个狭缝系统测量。均匀冗余阵列（URA）也可以通过使用它作为移相掩模3被用于光束相干性的测量。虽然该技术可以提供完整的CCF，它不是无模型。最近，基于Talbot效应干涉测量技术使用周期性对象的自成像特性被开发。这些干涉仪利用在光栅下游获得梁横向连贯性4-9一些自成像距离测量的干涉知名度。使用两个光栅系统横向连贯性的测量也有报道7。 映射横梁一致性，沿垂直和水平方向同时首先由日本特Guigay 等报道5。最近，科学家在光学组，X射线科学部（XSD），APS的报告两个新技术测量光束沿两个以上方向上同时使用两种方法横梁连贯性:一个具有棋盘相位光栅8，另具有圆形相位光栅9。 本文中的测量电键相和数据分析程序用于获得光束的横向相干沿0°，45°，90°，和135°方向相对于水平方向，同时说明。测量在APS的1-BM束线进行与棋盘π/ 2的相位光栅。在协议部分中列出这项技术的细节包括:1）实验规划; 2）制备的2-D棋盘相位光栅; 3）实验的设置和调整的同步加速器设施; 4）进行一致性测试; 5）数据分析。另外，代表性的结果示来说明该技术。这些程序可以在与光栅图案的最小变化许多同步加速器束线进行。

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			<td height="63" style="height:63px;width:215px;">1-BM-B bending magnet x-ray source</td>
			<td style="width:128px;">Advanced photon Source/ Argonne National Lab</td>
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			<td style="width:167px;"><a href="http://www.aps.anl.gov/Xray_Science_Division/Optics/Beamline/">http://www.aps.anl.gov/Xray_Science_Division/Optics/Beamline/</a></td>
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			<td>Proteus Inc</td>
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			<td style="width:128px;">AJA International Inc</td>
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			<td><a href="http://www.ajaint.com/systems_atc.htm">http://www.ajaint.com/systems_atc.htm</a></td>
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			<td style="width:128px;">Laurell Technologies Corporation</td>
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			<td style="width:128px;">JEOL</td>
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			<td><a href="http://www.jeolusa.com/PRODUCTS/PhotomaskDirectWriteLithography/ElectronBeamLithography/JBX-9500FS/tabid/245/Default.aspx">http://www.jeolusa.com/PRODUCTS/PhotomaskDirectWriteLithography/ElectronBeamLithography/JBX-9500FS/tabid/245/Default.aspx</a></td>
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			<td height="21" style="height:21px;width:215px;">MICROPOSIT 1165 remover</td>
			<td style="width:128px;">Dow&#160;</td>
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measurement of x-ray beam coherence along multiple directions using 2-d checkerboard phase grating

一种用于一个技术过程使用一个单一的相位光栅干涉仪被报告给测量的同步辐射X射线源的横向相干性。测量是在先进光子源（APS）在阿贡国家实验室（ANL）的1-BM弯曲磁铁光束线证实。通过使用2-D棋盘π/ 2相移光栅，分别沿垂直和水平方向，以及沿45°和135°方向的水平方向上得到的横向相干长度。以下在本文中指定的技术细节，在相位沿着光束传播方向光栅的下游的不同位置进行测量干涉图。每个干涉的可见度值从分析其傅里叶变换图像的谐波峰提取。因此，沿各个方向上的相干长度可以从能见度的演变被提取的一个函数光栅到DETEC器的距离。连贯的同时测量长度在四个方向有助于确定高斯形的X射线源的相干性区域的椭圆形。多个方向干涉表征所报告的技术是选择适当的样本大小和方向，以及用于校正在相干散射实验部分相干效应很重要。还可以应用用于评估的X射线光学器件的相干性保持能力这种技术。

而详细的实验和仿真结果，可以在其他地方发现8，该部分仅显示选择的结果来说明上述测量和数据分析程序。 图1表示在APS 1-BM-B光束线实验设置。光束大小由一个1×1 平方毫米狭缝从弯曲磁体源放置在双晶单色（DCM）和25微米的上游限定。将DCM被调谐至18千电子伏的输出光子能量。 X射线束穿过放置在沿着光束路径的不同位置的几个铍窗（1毫米总厚度）。 图2（a）示出的2-D棋盘相的扫描电子显微镜图像的中心部分在ANL中心纳米材料（CNM）光栅制造。光栅周期为p = 4.8微米。发白方块是形成在金块在Si 3 N 4膜。光栅被放置在X射线束，使得其垂直于光束方向和方金块的对角线平行于水平和垂直方向， 如图2（b）中 。这种取向有两个目的:（ⅰ）它保证沿主方向，其是沿水平及垂直方向较高的知名度，以及（ii）它减少了沿主方向8光栅周期的制造不确定性的影响。 干涉被记录在不同的光栅到检测器的距离，D，覆盖至少五个Vθ（ 四 ）的峰中的每个横向方向如等式（1）定义。 图3示出了所测量的干涉图在中央部分（a） ð1,0°= 83毫米和（b）D 4,0 &lt;/子&gt;°=579毫米，其对应于第一和第四峰值位置沿θ= 0°方向（ 第 0°= 3.4微米）。在这些塔尔博特距离2-D棋盘图案复制（自成像）。的X射线束的相干属性嵌入在干涉的可见性，这是​​从每个记录图像的傅立叶分析检索。 傅立叶变换所测量的干涉图产生谐波峰具有代表性的沿不同方向的干涉图的周期性质。作为一个例子， 图3（c）和（d）是图3的FT图像（a）和（b）中 ，分别进行由快速傅立叶变换（FFT）。由于对FT图像的中心对称，四个独立的1级峰是沿四个方向，即本&lt;青霉&gt;θ= 0°，45°，如在图2中定义90°和135°（b）中 。周期（ 对θ）在每个方向可以从相对于中心0 阶峰的峰位置来确定。采取如图3（c）为例，沿0°方向上的1 次高次谐波峰揭示具有p 0°=周期性结构3.4微米，其可以在图3中可以很容易地确定为线式结构（a）中 。能见度是由1级峰值幅度的比例给予（Aθ，1）的0 阶峰（Aθ，0），或Vθ= 2] Aθ，1 / Aθ， 0 10。在实践中获得的知名度以下协议的步骤5.5-5.7，在Figu所示的作物箱水库图3（c）和（d）。显然，1级的峰值的在0℃的强度是图3的（d）比图3（c）中 ，它表示在d =579毫米一个低能见度小得多。这也在图3证明在缺乏周期性结构的沿0°（b）中 。 以下协议步骤5.8-5.12， 图3（e）示出的可见性演化为d的函数。高斯拟合各地Vθ（ 四 ）峰所选择的数据给出了σ0°= 180毫米。水平相干长度从而ξ0°= 3.6微米以下的式（5）。 类似于图3中 ，沿θ 图4呈现的结果= 45°的方向。金融时报图像[参见图4的（c）和（d）]表示一个周期p 45°= 2.4微米。因此，Vθ（d）就45°的峰出现在与0°比较更短的距离（D 1,45°= 43毫米和Ð4,45°= 293毫米）。在这个距离，为45°时，干涉图是一个网型图案〔参见图4的（a）和（b）〕。在图4（e）所示的可见性进化给出的相干长度ξ45°= 5.0微米。通过应用相同的数据分析程序，所有四个可用方向，该X射线束的横向相干性区域被映射。 <img alt="图1" src="/files/ftp_upload/53025/53025fig1.jpg" /> 图1.实验装置，原理图束线安装在APS的1-BM-B光束线。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53025/53025fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/53025/53025fig2.jpg" /> 图2的2-D棋盘光栅（a）中的棋盘具有周期为4.8μm光栅的SEM图像。 （ 二 ）光栅在横向平面取向垂直于该光束传播方向（指向进或出纸的）。红色数字表示θ。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53025/53025fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图3" src="/files/ftp_upload/53025/53025fig3.jpg" /> 图3可见:测量<html>沿0°方向urement。干涉图记录在d 1，0°= 83毫米（ 一 ）和d 4,0°=579毫米（b）中 ，对应于第一和第四-V 0°（D）峰值位置沿0°方向（等式（1）与对 0°= 3.4微米）分别。其傅立叶分别变换图像示于（c）和（d）中 ，与表示第 0的红色虚线和绿色虚线区域和1 次谐波的图像，。 （ 五 ）能见度演变光栅到检测器的距离的函数，D。蓝色的圆圈是所有的实验数据，而红色子弹是围绕每个塔尔博特距离选择高斯信封接头（红色虚线）的数据。T ="_空白"&gt;点击此处查看该图的放大版本。 <img alt="图4" src="/files/ftp_upload/53025/53025fig4.jpg" /> 图4.能见度沿45°的方向测量。干涉图记录在d 1,45°= 43毫米（ 一 ）和d 4,45°=293毫米（b）中 ，对应于第一和第四V 45°（D）峰（用对 45°= 2.4微米等式（1））分别与（c）中示出其FT图像和（d），沿45°方向的位置。 （ 五 ）能见度演化为d的函数。参见图3说明的详细信息。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53025/53025fig4large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图5" src="/files/ftp_upload/53025/53025fig5.jpg" /> 图5.一致性区域地图。一致性区域使用测量横向连贯性沿着四个方向长度可视化。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53025/53025fig5large.jpg" target="_blank">请点击此处查看该图的放大版本。</a>

Watch this Scientific Journal Video about Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating at JoVE.com

Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating

测量协议和数据分析程序，给出用于获得同步辐射X射线源的横向相干沿四个方向同时使用一个单一的2-D棋盘相位光栅。这个简单的技术可应用于的X射线源和X射线光学器件完成横向相干性的表征。

使用2-D棋盘相位光栅X射线束相干测量沿多个方向

A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is ...

measurement-x-ray-beam-coherence-along-multiple-directions-using-2-d

Nanyang Technological University

Research

JoVE Journal

Engineering

9.5K 次观看.  Argonne National Laboratory. 测量协议和数据分析程序，给出用于获得同步辐射X射线源的横向相干沿四个方向同时使用一个单一的2-D棋盘相位光栅。这个简单的技术可应用于的X射线源和X射线光学器件完成横向相干性的表征。 

视频: Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing

The application of femtosecond four-wave mixing to the study of fundamental properties of diluted magnetic semiconductors ((s,p)-d hybridization, spin-flip scattering) is described, using experiments on GaMnAs as a prototype III-Mn-V system.&#160; Spectrally-resolved and time-resolved experimental configurations are described, including the use of zero-background autocorrelation techniques for pulse optimization.&#160; The etching process used to prepare GaMnAs samples for four-wave mixing experiments is also highlighted.&#160; The high temporal resolution of this technique, afforded by the use of short (20 fsec) optical pulses, permits the rapid spin-flip scattering process in this system to be studied directly in the time domain, providing new insight into the strong exchange coupling responsible for carrier-mediated ferromagnetism.&#160; We also show that spectral resolution of the four-wave mixing signal allows one to extract clear signatures of (s,p)-d hybridization in this system, unlike linear spectroscopy techniques.&#160;&#160; This increased sensitivity is due to the nonlinearity of the technique, which suppresses defect-related contributions to the optical response. This method may be used to measure the time scale for coherence decay (tied to the fastest scattering processes) in a wide variety of semiconductor systems of interest for next generation electronics and optoelectronics.

The technique of femtosecond four-wave mixing is described, including spectrally-resolved and time-resolved configurations. We illustrate the utility of this technique for the investigation of crucial physical properties in the III-V diluted magnetic semiconductors, afforded by its nonlinearity and high temporal resolution.

The application of femtosecond four-wave mixing to the study of fundamental properties of diluted magnetic semiconductors ((s,p)-d hybridization, ...

科研

工程学

Reservoir Condition Pore-scale Imaging of Multiple Fluid Phases Using X-ray Microtomography

X-ray microtomography was used to image, at a resolution of 6.6 &#181;m, the pore-scale arrangement of residual carbon dioxide ganglia in the pore-space of a carbonate rock at pressures and temperatures representative of typical formations used for CO2 storage. Chemical equilibrium between the CO2, brine and rock phases was maintained using a high pressure high temperature reactor, replicating conditions far away from the injection site. Fluid flow was controlled using high pressure high temperature syringe pumps. To maintain representative in-situ conditions within the micro-CT scanner a carbon fiber high pressure micro-CT coreholder was used. Diffusive CO2 exchange across the confining sleeve from the pore-space of the rock to the confining fluid was prevented by surrounding the core with a triple wrap of aluminum foil. Reconstructed brine contrast was modeled using a polychromatic x-ray source, and brine composition was chosen to maximize the three phase contrast between the two fluids and the rock. Flexible flow lines were used to reduce forces on the sample during image acquisition, potentially causing unwanted sample motion, a major shortcoming in previous techniques. An internal thermocouple, placed directly adjacent to the rock core, coupled with an external flexible heating wrap and a PID controller was used to maintain a constant temperature within the flow cell. Substantial amounts of CO2 were trapped, with a residual saturation of 0.203 &#177; 0.013, and the sizes of larger volume ganglia obey power law distributions, consistent with percolation theory.

We present a methodology for the imaging of multiple fluid phases at reservoir conditions by the use of x-ray microtomography. We show some representative results of capillary trapping in a carbonate rock sample.

多重流体相储层孔隙条件级成像使用X射线微断层

X-ray microtomography was used to image, at a resolution of 6.6 &#181;m, the pore-scale arrangement of residual carbon dioxide ganglia in the pore-space ...

Energy Dispersive X-ray Tomography for 3D Elemental Mapping of Individual Nanoparticles

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial resolution, and is even capable of providing atomically resolved elemental maps. In this technique, a highly focused electron beam is incident upon a thin sample and the energy of emitted X-rays is measured in order to determine the atomic species of material within the beam path. This elementally sensitive spectroscopy technique can be extended to three dimensional tomographic imaging by acquiring multiple spectrum images with the sample tilted along an axis perpendicular to the electron beam direction.
Elemental distributions within single nanoparticles are often important for determining their optical, catalytic and magnetic properties. Techniques such as X-ray tomography and slice and view energy dispersive X-ray mapping in the scanning electron microscope provide elementally sensitive three dimensional imaging but are typically limited to spatial resolutions of &gt; 20 nm. Atom probe tomography provides near atomic resolution but preparing nanoparticle samples for atom probe analysis is often challenging. Thus, elementally sensitive techniques applied within the scanning transmission electron microscope are uniquely placed to study elemental distributions within nanoparticles of dimensions 10-100 nm.
Here, energy dispersive X-ray (EDX) spectroscopy within the STEM is applied to investigate the distribution of elements in single AgAu nanoparticles. The surface segregation of both Ag and Au, at different nanoparticle compositions, has been observed.

The use of energy dispersive X-ray tomography in the scanning transmission electron microscope to characterize elemental distributions within single nanoparticles in three dimensions is described.

能量色散X射线断层摄影术对个人纳米3D元素映射

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial ...

Failure Analysis of Batteries Using Synchrotron-based Hard X-ray Microtomography

Imaging morphological changes that occur during the lifetime of rechargeable batteries is necessary to understand how these devices fail. Since the advent of lithium-ion batteries, researchers have known that the lithium metal anode has the highest theoretical energy density of any anode material. However, rechargeable batteries containing a lithium metal anode are not widely used in consumer products because the growth of lithium dendrites from the anode upon charging of the battery causes premature cell failure by short circuit. Lithium dendrites can also form in commercial lithium-ion batteries with graphite anodes if they are improperly charged. We demonstrate that lithium dendrite growth can be studied using synchrotron-based hard X-ray microtomography. This non-destructive imaging technique allows researchers to study the growth of lithium dendrites, in addition to other morphological changes inside batteries, and subsequently develop methods to extend battery life.

Synchrotron-based hard X-ray microtomography is used to image the electrochemical growth of dendrites from a lithium metal electrode through a solid polymer electrolyte membrane.

电池的使用同步为基础的硬X射线微断层故障分析

Imaging morphological changes that occur during the lifetime of rechargeable batteries is necessary to understand how these devices fail. Since the advent ...

Speciation and Bioavailability Measurements of Environmental Plutonium Using Diffusion in Thin Films

The biological uptake of plutonium (Pu) in aquatic ecosystems is of particular concern since it is an alpha-particle emitter with long half-life which can potentially contribute to the exposure of biota and humans. The diffusive gradients in thin films technique is introduced here for in-situ measurements of Pu bioavailability and speciation. A diffusion cell constructed for laboratory experiments with Pu and the newly developed protocol make it possible to simulate the environmental behavior of Pu in model solutions of various chemical compositions. Adjustment of the oxidation states to Pu(IV) and Pu(V) described in this protocol is essential in order to investigate the complex redox chemistry of plutonium in the environment. The calibration of this technique and the results obtained in the laboratory experiments enable to develop a specific DGT device for in-situ Pu measurements in freshwaters. Accelerator-based mass-spectrometry measurements of Pu accumulated by DGTs in a karst spring allowed determining the bioavailability of Pu in a mineral freshwater environment. Application of this protocol for Pu measurements using DGT devices has a large potential to improve our understanding of the speciation and the biological transfer of Pu in aquatic ecosystems.

The technique of diffusive gradients in thin films (DGT) is proposed for speciation studies of plutonium. This protocol describes diffusion experiments probing the behavior of Pu(IV) and Pu(V) in presence of organic matter. DGTs deployed in a karstic spring allow assessment of the bioavailability of Pu.

环境钚的薄膜弥散形态和生物利用度测量

The biological uptake of plutonium (Pu) in aquatic ecosystems is of particular concern since it is an alpha-particle emitter with long half-life which can ...

Protocol of Electrochemical Test and Characterization of Aprotic Li-O2 Battery

We demonstrate a method for electrochemical testing of an aprotic Li-O2 battery. An aprotic Li-O2 battery is made of a Li-metal anode, an aprotic electrolyte, and an O2-breathing cathode. The aprotic electrolyte is a solution of lithium salt with aprotic solvent; and porous carbon is commonly used as the cathode substrate. To improve the performance, an electrocatalyst is deposited onto the porous carbon substrate by certain deposition methods, such as atomic layer deposition (ALD) and wet-chemistry reaction. The as-prepared cathode materials are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray absorption near edge structure (XANES). A Swagelok-type cell, sealed in a glass chamber filled with pure O2, is used for the electrochemical test on a battery test system. The cells are tested under either capacity-controlled mode or voltage controlled mode. The reaction products are investigated by electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, and Raman spectroscopy to study the possible pathway of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). This protocol demonstrates a systematic and efficient arrangement of routine tests of the aprotic Li-O2 battery, including the electrochemical test and characterization of battery materials.

Protocol of Electrochemical Test and Characterization of Aprotic Li-O2 Battery

A protocol for the electrochemical testing of an aprotic Li-O2 battery with the preparation of electrodes and electrolytes and an introduction of the frequently used methods of characterization is presented here.

电化学测试的协议及表征非质子锂的O<sub&gt; 2</sub&gt;电池

We demonstrate a method for electrochemical testing of an aprotic Li-O2 battery. An aprotic Li-O2 battery is made of a Li-metal anode, an aprotic ...

Dynamic Pore-scale Reservoir-condition Imaging of Reaction in Carbonates Using Synchrotron Fast Tomography

Underground storage permanence is a major concern for carbon capture and storage. Pumping CO2 into carbonate reservoirs has the potential to dissolve geologic seals and allow CO2 to escape. However, the dissolution processes at reservoir conditions are poorly understood. Thus, time-resolved experiments are needed to observe and predict the nature and rate of dissolution at the pore scale. Synchrotron fast tomography is a method of taking high-resolution time-resolved images of complex pore structures much more quickly than traditional &#181;-CT. The Diamond Lightsource Pink Beam was used to dynamically image dissolution of limestone in the presence of CO2-saturated brine at reservoir conditions. 100 scans were taken at a 6.1 &#181;m resolution over a period of 2 hours. The images were segmented and the porosity and permeability were measured using image analysis and network extraction. Porosity increased uniformly along the length of the sample; however, the rate of increase of both porosity and permeability slowed at later times.

Synchrotron fast tomography was used to dynamically image dissolution of limestone in the presence of CO2-saturated brine at reservoir conditions. 100 scans were taken at a 6.1 &#181;m resolution over a period of 2 h.

用同步快速反应层析成像动态孔隙规模油藏条件下成像碳酸盐

Underground storage permanence is a major concern for carbon capture and storage. Pumping CO2 into carbonate reservoirs has the potential to dissolve ...

Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic

X-ray spectra provide a wealth of information on high temperature plasmas; for example electron temperature and density can be inferred from line intensity ratios. By using a Johann spectrometer viewing the plasma, it is possible to construct profiles of plasma parameters such as density, temperature, and velocity with good spatial and time resolution. However, benchmarking atomic code modeling of X-ray spectra obtained from well-diagnosed laboratory plasmas is important to justify use of such spectra to determine plasma parameters when other independent diagnostics are not available. This manuscript presents the operation of the High Resolution X-ray Crystal Imaging Spectrometer with Spatial Resolution (HIREXSR), a high wavelength resolution spatially imaging X-ray spectrometer used to view hydrogen- and helium-like ions of medium atomic number elements in a tokamak plasma. In addition, this manuscript covers a laser blow-off system that can introduce such ions to the plasma with precise timing to allow for perturbative studies of transport in the plasma.

X-ray spectra provide a wealth of information on high temperature plasmas. This manuscript presents the operation of a high wavelength resolution spatially imaging X-ray spectrometer used to view hydrogen- and helium-like ions of medium atomic number elements in a tokamak plasma.

运用X射线成像光谱水晶的使用为高温等离子体诊断

X-ray spectra provide a wealth of information on high temperature plasmas; for example electron temperature and density can be inferred from line ...

Optical Trap Loading of Dielectric Microparticles In Air

We demonstrate a method to trap a selected dielectric microparticle in air using radiation pressure from a single-beam gradient optical trap. Randomly scattered dielectric microparticles adhered to a glass substrate are momentarily detached using ultrasonic vibrations generated by a piezoelectric transducer (PZT). Then, the optical beam focused on a selected particle lifts it up to the optical trap while the vibrationally excited microparticles fall back to the substrate. A particle may be trapped at the nominal focus of the trapping beam or at a position above the focus (referred to here as the levitation position) where gravity provides the restoring force. After the measurement, the trapped particle can be placed at a desired position on the substrate in a controlled manner. 
In this protocol, an experimental procedure for selective optical trap loading in air is outlined. First, the experimental setup is briefly introduced. Second, the design and fabrication of a PZT holder and a sample enclosure are illustrated in detail. The optical trap loading of a selected microparticle is then demonstrated with step-by-step instructions including sample preparation, launching into the trap, and use of electrostatic force to excite particle motion in the trap and measure charge. Finally, we present recorded particle trajectories of Brownian and ballistic motions of a trapped microparticle in air. These trajectories can be used to measure stiffness or to verify optical alignment through time domain and frequency domain analysis. Selective trap loading enables optical tweezers to track a particle and its changes over repeated trap loadings in a reversible manner, thereby enabling studies of particle-surface interaction.

A protocol for launching and stably trapping selected dielectric microparticles in air is presented.

介电微粒的光阱装载在空气中

We demonstrate a method to trap a selected dielectric microparticle in air using radiation pressure from a single-beam gradient optical trap. Randomly ...

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder microdiffraction two-dimensional (2D) maps at beamline 12.3.2 of the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. Measurements can be performed on any sample that is less than 10 cm x 10 cm x 5 cm, with a flat exposed surface. The experimental geometry is calibrated using standard materials (elemental standards for XRF, and crystalline samples such as Si, quartz, or Al2O3 for diffraction). Samples are aligned to the focal point of the x-ray microbeam, and raster scans are performed, where each pixel of a map corresponds to one measurement, e.g., one XRF spectrum or one diffraction pattern. The data are then processed using the in-house developed software XMAS, which outputs text files, where each row corresponds to a pixel position. Representative data from moissanite and an olive snail shell are presented to demonstrate data quality, collection, and analysis strategies.

We describe a beamline setup meant to carry out rapid two-dimensional x-ray fluorescence and x-ray microdiffraction mapping of single crystal or powder samples using either Laue (polychromatic radiation) or powder (monochromatic radiation) diffraction. The resulting maps give information about strain, orientation, phase distribution, and plastic deformation.