CHARACTERIZATION OF CCD DETECTOR ELECTRONICS FOR RECORDING WEAK X-RAY SCATTERING

用于记录弱 X 射线散射的 CCD 探测器电子器件的特性

• 批准号: 7598179
• 负责人: HIROTSUGU TSURUTA
• 金额: $ 3.57万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7598179
• 关键词: Address; Area; Characteristics; Computer Retrieval of Information on Scientific Projects Database; Computer software; Contract Services; Data; Data Collection; Detection; Development; Electronics; Financial compensation; Funding; Grant; Image; Institution; Masks; Measures; Numbers; Positioning Attribute; Process; Proteins; Protocols documentation; Research; Research Personnel; Resources; Sampling; Series; Solutions; Source; Specific qualifier value; Test Result; United States National Institutes of Health; Vendor; X-Ray Crystallography; computerized data processing; desire; detector; improved; programs

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. We addressed the detector offset (baseline) fluctuation issue with our MarCCD165 detector as described last year. The improved baseline stability of ~0.2 ADU was verified earlier this year immediately following the upgrade by the detector vendor through our service contract. In parallel, we modified our data collection protocol for additional compensation of the baseline fluctuation, making this detector highly effective in x-ray scattering studies of weakly scattering samples. The two major changes to data collection protocol to compensate for this small level of electronic drift are 1) each set of a series of data collection (typically 20 images of 10s exposure each) is preceded by a recording of ¿dark image¿ which is subtracted automatically from each data frame in the data collection software. Each dark image is also stored as a file series number ¿zero¿ for later use; 2) the detector received a mask which covers small areas on the detector active area at 3 and 9 o¿clock positions so that each data frame has an internal measure of true baseline level in all four detector quadrants, which can have different baseline levels due to independent readout circuits. The SSRL-developed data processing program MarParse has an option of using either a user-defined global baseline value or the actual offset values measured individually for four quadrants in the first step of data processing. These developments allow us to provide users with much more reliable solution scattering data in combination with the larger detection area for azimuth averaging, compared to the much smaller area covered by our linear detector. The MarCCD165 detector, which was originally purchased for single crystal diffraction studies and other studies involving strong x-ray scatterers, has been in routine use in protein solution x-ray scattering for the entire duration of 2006. The test results we obtained in the process of these improvements have also provided a bench mark for specifying desired detector characteristics for our new CCD detector

该副本是使用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这是调查员的机构。 如去年所述，我们解决了我们的MARCCD165检测器的检测器偏移（基线）波动问题。探测器供应商通过我们的服务合同升级后，今年早些时候对基线稳定性提高了约0.2 ADU。同时，我们修改了数据收集方案，以增加基线波动的额外补偿，使该检测器在弱散射样品的X射线散射研究中非常有效。数据收集协议的两个重大更改是为了补偿这一少量电子钻的1）每组一组数据收集（通常为20张10s曝光的20张图像）之前是记录»Dark Image波的记录，该记录是从数据收集软件中的每个数据框架中自动减去的。每个深色图像也被存储为文件系列编号„零``零''供以后使用； 2）检测器收到了一个面具，该面具覆盖了检测器活动区域在3和9 o的时钟位置上的较小区域，因此每个数据框架在所有四个检测器象限中都具有对真实基线水平的内部测量，由于独立的读取电路，这可能具有不同的基线水平。 SSRL开发的数据处理程序MARPARSE具有使用用户定义的全局基线值或在数据处理的第一步中针对四个象限分别测量的实际偏移值。与我们的线性检测器所覆盖的较小的区域相比，这些发展使我们能够为用户提供更可靠的解决方案散射数据，并为方位平均提供更大的检测区域。 MARCCD165检测器最初用于单晶衍射研究和其他涉及强X射线散射器的研究，在2006年的整个过程中一直在蛋白质溶液X射线散射中常规使用。我们在这些改进过程中获得的测试结果也为我们提供了用于我们新的CCD检测器的基准标记，以实现我们新的CCD探测器特征。