COMMISSIONING AND CHARACTERIZATION OF THE SAXS PILATUS 300K DETECTOR FOR BL4-2

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。 在新的Pilatus 300K探测器安装在束线上后不久，我们对其性能进行了表征。我们的实验结果保证了探测器的工作符合其出厂规范。最值得注意的是，由于它是一个光子计数探测器，它几乎没有噪音，暗计数为零。在实际实验中，记录到了超过6个数量级的极高线性度。像素饱和级别比我们迄今记录的最强散射信号级别高出4个数量级，因此我们预计将达到近10个数量级的出色动态范围。我们使用Rayonix MX225HE探测器记录了相同的病毒溶液散射模式，以便与Pilatus 300K进行直接比较。研究发现，Pilatus 300K极窄的点扩散函数可以非常准确地记录来自大分子络合物和组件(如病毒粒子)的散射信号，这些组件在束挡附近表现出散射信号的快速衰减和非常尖锐的散射极小值。我们还发现，在考虑了不同的像素大小和光子检测效率后，两种检测器都以相对较高的总体信噪比提供了类似的高数据质量。在夏季关闭之前，我们已经使用我们的Pilatus 300K进行了几个实际的时间分辨X射线溶液散射研究。我们计划在不久的将来将这种探测器集成到我们的标准蓝冰数据收集系统中。

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 characterized the performance of the new Pilatus 300K detector shortly after its installation on the beam line. Our experimental results assured that the detector works according to its factory specifications. Most notably, it exhibits virtually no noise and zero dark counts by the virtue of being a photon counting detector. An exceptionally high linearity over at last 6 orders of magnitude has been recorded in actual experiments. The pixel saturation level is 4 orders of magnitude higher than the strongest level of scattering signal we have so far recorded so that we anticipate nearly 10 orders of excellent dynamic range. We recorded the same virus solution scattering pattern using our Rayonix MX225HE detector for direct comparison with Pilatus 300K. It was found that the exceptionally narrow point spread function of Pilatus 300K allows very accurate recording of scattering signal from large macromolecular complexes and assemblies such as virus particles, which exhibit rapid decline in scattering signal near the beam stop and very sharp scattering minima. We also found that both detectors provide similarly high data quality with a comparably high overall signal-to-noise ratio after taking into account different pixel sizes and photon detection efficiencies. We have used our Pilatus 300K in several of actual time-resolved x-ray solution scattering studies before summer shutdown. We plan on incorporating this detector in our standard Blu-Ice data collection system in near future.