DEVELOPMENT OF BEAMLINE X29 FOR HIGH THROUGHPUT

开发用于高吞吐量的 Beamline X29

• 批准号: 7602348
• 负责人: HOWARD T ROBINSON
• 金额: $ 9.63万
• 依托单位: BROOKHAVEN SCIENCE ASSOC-BROOKHAVEN LAB
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7602348
• 关键词: Age; Automation; Automobile Driving; Back; Beds; Calendar; Cells; Complex; Computer Retrieval of Information on Scientific Projects Database; Computer software; Custom; Data; Data Collection; Data Set; Decompression Sickness; Deposition; Development; Diagnosis; Elements; Failure; Funding; Goals; Grant; Hour; Imagery; Individual; Institution; Light; Logic; Mails; Measurement; Measures; Mechanics; Methods; Metric; Mind; Nature; Noise; Numbers; Operative Surgical Procedures; Optics; Output; Performance; Positioning Attribute; Procedures; Production; Productivity; Program Development; Publications; Records; Recurrence; Reporting; Research; Research Personnel; Resources; Rewards; Running; Rupture; Safety; Schedule; Scheme; Scientist; Seminal; Signal Transduction; Source; Specimen; Speed; Spottings; Standards of Weights and Measures; System; Telemetry; Testing; Time; United States National Institutes of Health; Vacuum; Visit; Water; Work; beamline; cryogenics; day; detector; digital; experience; improved; prevent; research study; seal; size; software development

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. Objectives  Our aim for X29 is to use it both as the venue for highly responsive production of excellent diffraction data, and as a workbench for creating new methods that improve speed and accuracy. We expected to explore use of the automounter and to develop improved software and methods to allow remote observation and operation, the interleaving of many projects, and improved handling of every experimental parameter from crystal centering to custom tuning of x-ray optical systems. Results  The "High Speed" aspect of beamline X29 has helped to drive our operations and development program in 2006. During the 06-07 grant year there have been 647 scheduled data-collection sessions, 34 of which employed the automounter. There was a large Mail-in operation, and this employed about 167 visits of the beam time. During 0.5% of the time, the automounter was in operation, and about one quarter of this was local scientists doing Mail-in work. X29 is increasing in productivity, as measured by the standard metrics of the time: our records show that during 2006 there were 84 PDB depositions attributed to X29, and 55 publications, five each in Nature and Cell. This is a good record, and its about twice the numbers reported in 2005. X29 is coming of age. An early feature of our operation of X29 has been to schedule short visits, keeping prime time, that is 7AM-3PM on weekdays, for short experiments and development projects. Last year we also invented the quick ID project, which was an opportunity for users at dipole beamlines, even those not our own (X4, X6), to ask for a few hours on X29 to take a seminal data set. During the course of this last year we have been able to employ the PX Operators more intensely in getting users started on the pre-scheduled runs and especially in moving them in to do quick projects. The new calendar function in PXDB (see software) is extremely valuable in getting this to work well. Continual efforts to diagnose problems and improve performance have produced incremental progress. We got Crystal Logic to improve the synchronization of the omega/shutter operation, and now it appears that exposures down to 100ms can be made with essentially perfect timing. A common theme for most data-collection projects is the attempt to minimize x-ray damage to crystals. We reason that one can get the most out of a crystal by attempting to maximize the signal-to-noise ratio throughout the measurement. To help this, we wanted to be able to tailor the x-ray beam more precisely to the specimen and the mode of data collection. Obviously it pays to make certain the x-ray beam is no bigger than the actual physical size of the crystal, and the motorized slits accomplish this very nicely. In addition one might alter the convergence of the x-ray beam coming from the two focusing elements, the goal being to make the reflections as tight and sharp as possible on the detector. In the case of vertical focusing, we open up that focus to give a beam about 100¿m high at the specimen position that is nearly parallel. In the case of horizontal focusing, we can be subtle. To obtain the maximum x-ray intensity, we focus the beam on the limiting slit to get the most light through. The horizontal divergence would be 1mrad; with a specimen-to-detector distance of 200mm the spots on the detector would be widened by 0.2mm. If we relax the bending on the crystal, putting the focal point downstream of the limiting slit, the edges of the beam are cut off by the slit and the result is that the beam hitting the crystal has a lower crossfire. Therefore our standard operating procedure is to produce a beam with a 0.4mrad convergence (which is about ¿ the maximum intensity that is possible). When the detector is far back, say <400mm, we use 0.2mrad convergence with a concomitantly lower intensity. The very clear advantage of this is that slightly longer exposure times are rewarded by smaller spots on the detector and much improved signal-to-noise ratios for the data, thereby improving the output from each crystal. X29 has also been a test bed for software development, especially driving the use of the dna automation system. Also we are exploring the possibility of automating the sequential use of specific parts of an individual large crystal, probing it with a small beam. These are described in the Software section. The beamline has experienced two significant mechanical failures during the last year. The main x-ray shutter, which is behind the x-ray ring shield wall and therefore difficult to get at, had a complex failure that involved damage to a water-cooling line in June 06. The technical staff from our partners at Case Western Reserve and the NSLS beamline staff mobilized and got it fixed in 60 days. Then more recently, in March, a complex failure of the cryogenic cooling system for the monocromator failed, and this ruptured the seal inside the vacuum chamber. The CWR team managed to fix this, and to add safety telemetry to prevent a recurrence, with only 1.5 days of missed data collection. Plans  Things are running extremely well, but we have incremental improvements in mind. The plan to produce a queuing scheme that will allow the PXOps and dna to take data for remote users is badly needed here and we expect to drive that development. Users complain regularly about crystal visualization, and we plan to mount a very high quality digital video camera to help with that (see software). The plan to allow sequential probing of pre-selected regions on a crystal is really driven by the rapid damage crystals experience at X29, and we will work to get this running during the next grant year.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目和 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 目标 我们对 X29 的目标是将其用作高响应性生成优秀衍射数据的场所，以及创建提高速度和准确性的新方法的工作台。 我们期望探索自动安装机的使用，并开发改进的软件和方法，以允许远程观察和操作、许多项目的交错，以及改进从晶体居中到 X 射线光学系统的定制调谐的每个实验参数的处理。 结果 光束线 X29 的“高速”方面帮助推动了我们 2006 年的运营和开发计划。在 06-07 资助年度期间，已安排了 647 次数据收集活动，其中 34 次使用了自动安装机。 有一次大型的邮寄操作，这占用了大约 167 次访问的时间。 在 0.5% 的时间里，自动安装机处于运行状态，其中大约四分之一是当地科学家在进行邮寄工作。 按照当时的标准衡量标准，X29 的生产力正在不断提高：我们的记录显示，2006 年，X29 发表了 84 篇 PDB 论文，发表了 55 篇论文，其中《自然》和《细胞》各发表了 5 篇。 这是一个不错的记录，大约是 2005 年报告数字的两倍。X29 即将成熟。 我们 X29 运营的一个早期特点是安排短期访问，保持黄金时间，即工作日上午 7 点至下午 3 点，进行短期实验和开发项目。 去年，我们还发明了快速 ID 项目，这为偶极光束线的用户提供了一个机会，即使是那些不是我们自己的（X4、X6）的用户，也可以要求在 X29 上花几个小时来获取开创性的数据集。 在去年的过程中，我们能够更积极地使用 PX 操作员来让用户开始预先安排的运行，特别是让他们参与快速项目。 PXDB 中的新日历功能（参见软件）对于使其正常运行非常有价值。 诊断问题和提高性能的持续努力已经取得了渐进的进展。 我们使用 Crystal Logic 来改进 omega/快门操作的同步性，现在看来可以通过基本完美的定时进行低至 100 毫秒的曝光。 大多数数据收集项目的一个共同主题是尝试尽量减少 X 射线对晶体的损害。 我们认为，通过尝试在整个测量过程中最大化信噪比，可以充分利用晶体。 为了帮助实现这一目标，我们希望能够更精确地根据样本和数据收集模式定制 X 射线束。 显然，确保 X 射线束不大于晶体的实际物理尺寸是值得的，而电动狭缝可以很好地实现这一点。 此外，还可以改变来自两个聚焦元件的 X 射线束的会聚，目标是使探测器上的反射尽可能紧密和清晰。 在垂直聚焦的情况下，我们打开焦点，在几乎平行的样本位置处发出约 100 米高的光束。 在水平对焦的情况下，我们可以做到微妙。 为了获得最大的 X 射线强度，我们将光束聚焦在限制狭缝上，以获得最多的光线通过。 水平发散度为1mrad；当样品到探测器的距离为 200mm 时，探测器上的光斑将加宽 0.2mm。 如果我们放松晶体上的弯曲，将焦点放在限制狭缝的下游，光束的边缘就会被狭缝切断，结果是撞击晶体的光束具有较低的交火。 因此，我们的标准操作程序是产生会聚度为 0.4mrad 的光束（大约是可能的最大强度）。 当探测器距离较远（例如 <400mm）时，我们使用 0.2mrad 会聚，同时强度也较低。 这样做的一个非常明显的优点是，稍微长一点的曝光时间会带来探测器上更小的光斑和大大提高的数据信噪比，从而提高每个晶体的输出。 X29 也是软件开发的测试平台，特别是推动 DNA 自动化系统的使用。 此外，我们还在探索自动顺序使用单个大晶体的特定部分的可能性，并用小光束对其进行探测。 这些在“软件”部分中进行了描述。 去年，光束线经历了两次重大机械故障。 主 X 射线快门位于 X 射线环屏蔽墙后面，因此很难到达，6 月 6 日发生了复杂的故障，导致水冷却管路损坏。 凯斯西储合作伙伴的技术人员和 NSLS 光束线工作人员动员起来，在 60 天内修复了该问题。 最近，三月份，单色仪的低温冷却系统发生了复杂的故障，导致真空室内部的密封破裂。 CWR 团队设法解决了这个问题，并添加了安全遥测技术以防止再次发生，仅错失了 1.5 天的数据收集。 计划 事情进展得非常顺利，但我们考虑的是渐进式改进。 这里迫切需要制定一个排队方案，允许 PXOps 和 DNA 为远程用户获取数据，我们希望推动这一发展。 用户经常抱怨水晶可视化，我们计划安装一个非常高质量的数码摄像机来帮助解决这个问题（参见软件）。 允许对晶体上的预选区域进行顺序探测的计划实际上是由 X29 的快速损坏晶体经验驱动的，我们将努力在下一个拨款年度内实现这一目标。