MICRODIFFRACTION AT BEAMLINES X25 AND X29

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 X25和X29光束线上的显微衍射 罗宾逊·赫鲁 目标X25和X29都受益于常规从较小晶体收集衍射数据的能力的提高。我们协调了两条波浪器波束线之间的改进，为用户提供了更一致的环境。我们正在开发更好的方法来寻找小晶体，既有传统的光学方法，也有使用X射线进行网格搜索的方法。我们继续通过CBass对用户的分歧进行更好的控制。我们希望实施更多的诊断工具来监测NSLS发射的X射线束的稳定性。我们还在X25部署了一个类似于X29的自动挂载机。 结果用户通常使用50x50？m2的射束收集数据，方法是将集线器中的孔缝切开到所需的大小，并限制上游的射束大小以控制射束发散。在两条光束线上都安装了用于校准狭缝的宏。Soares使用大约10x10？m2的光束尺寸进行的微晶体实验不需要光束线科学家的任何特殊协助。这是一种非常有用的程序，可以通过“燃烧”含有可可酸的甘油溶液来显示样品(孔口+发散)处的光束大小。这一过程只需要几秒钟的X射线曝光，并具有确定光束大小和确认主轴与光束对准的双重目的。结晶学中的一个长期问题是将结晶定位在母液的海洋中。光学可视化是一个问题，因为母液上有眩光，存在光学失真，并且一个方向不可见(通过环路的一侧)。在这两条光束线上都安装了更好的数码相机。我们还实施了x射线网格搜索，以补充光学技术(见斯金纳的软件开发)。 我们在单色仪的下游安装了一个束流位置监测器。这种设备使我们能够记录光束的位置以及每一幅图像的强度。现在，对于在X25获取的每个数据集，用户在html日志的末尾具有波束行为的曲线图。我们将通过增加一个白光位置监测器来补充这项工作。 对聚焦镜马达的修复使我们能够改进水平聚焦260？m的光束垂直尺寸(设置在70-90？m)的优化。 我们为新的X射线荧光发射探测器购买了一台放大器/多道分析器。这是一个移动单元，可以根据用户的要求带到我们的任何光束线上。在几秒钟内，用户就可以扫描样本并确定存在哪些金属。 Q315探测器于去年夏天进行了升级。 计划我们将很快在X25安装一台自动装载机。我们正在获取一台白光位置监测器。这项工作是与NSLS-II实验设施部(J.Kiester)、BNL仪器小组(J.Smedley)和凯斯西大学(J.Bohon)合作完成的。这个新的监视器将被放置在25年前安装在XBPM上的位置。这种wBPM由安装在冷却室中的两个人造钻石晶体组成。光电流将被收集，并将为我们提供关于白色光束的质量和稳定性的信息。 重要意义对光束质量和稳定性有一个非常好的了解是考虑微光束时的基础。为了为在NSLS-II上进行的新实验做准备，为这类装置建立一个用户基础是很重要的。任何开发都必须考虑到用户及其需求。这是通过将x29和x25的努力结合在一起来实现的。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Microdiffraction at beamlines X25 and X29 H¿roux, Robinson Objectives  Both X25 and X29 are benefitting from improved capability to collect diffraction data routinely from smaller crystals. We have coordinated improvements between the two undulator beamlines to provide the users with a more consistent environment. We are pursuing the development of better ways to find small crystals with both conventional optics and with a grid search using x-rays. We continue implementing better control of the divergence to the users via CBASS. We want to implement more diagnostic tools to monitor the stability of the x-ray beam delivered by the NSLS. We are also deploying an automounter at X25 similar to that at X29. Results  Users are routinely collecting data with a 50x50 ¿m2 beam by slitting the apertures in the hutch to the desired size, and restricting the beam size upstream to control beam divergence. Macros to calibrate the slits have been implemented at both beamlines. Micro-crystal experiments by Soares using a beam size of approximately 10x10 ¿m2 did not require any special assistance from the beamline scientist. A very useful procedure to visualize the size of the beam at the sample (apertures + divergence) possible by the "burning" of a solution of glycerol containing cacodylic acid. This procedure takes only a few seconds of exposure to the x-rays and has a dual purpose of establishing the beam size and confirming alignment of the spindle with the beam. A chronic problem in crystallography is to localize the crystal in an ocean of mother liquor. Optical visualization is a problem since there is glare on the mother liquor, there is optical distortion, and one direction is not visible (through the side of the loop). Better digital cameras have been implemented at both beamlines. We have also implemented x-ray grid searches to supplement the optical technology (see software development by Skinner). We installed a beam-position monitor just downstream from the monochromator. This device enables us to record the position of the beam as well as the intensity for each image. The users now have plots of the behavior of the beam at the end of the html log for every dataset taken at X25. We will complement this work by the addition of a white-beam position monitor. Repair of the focusing-mirror motors has enabled us to improve the optimization of the vertical size of the beam (set at 70-90 ¿m) with a horizontal focus of 260 ¿m. We purchased an amplifier / multichannel-analyzer for a new x-ray fluorescence emission detector. This is a mobile unit which can be brought to any of our beamlines at the user's request. Within seconds, the users can scan the sample and determine what metals are present. The Q315 detector was upgraded last summer. Plans  We will install an automounter at X25 soon. We are in the process of acquiring a white-beam position monitor. This work is done in collaboration with the NSLS-II experimental facilities division (J. Kiester), BNL instrumentation group (J. Smedley) and Case Western University (J. Bohon). This new monitor will be positioned where a previous wBPM was installed at X25 years ago. This wBPM consists of two synthetic diamond crystals mounted in a cooled chamber. The photocurrent will be harvested and will give us information about the quality and stability of the white beam. Significance  Having a very good understanding of the beam quality and stability is fundamental when thinking about mini to micro beams. Developing a user base for this type of setup is important in order to prepare for new experiments done at NSLS-II. Any development has to take into account the users and their need. This is done by combining the efforts of X29 and X25 together.