PERMANENT SMALL ANGLE X-RAY SCATTERING STATION ON BEAM LINE 4-2

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者的研究机构。 SSRL结构分子生物学小角X射线散射设施BL 4 -2是一个致力于结构生物学研究的永久性实验站。它接收来自新的20极2-T摇摆器束的辐射的中心风扇。摇摆器继续在减小的摇摆器场（0.66T）下操作，以管理光学部件上的热负载，直到束线光学器件的完整SPEAR 3升级完成。为蛋白质、蛋白质组装体、病毒颗粒、生物纤维和脂质膜的结构生物学研究提供了最先进的实验设施。该仪器采用针孔几何小角散射相机，具有自动距离变化机制和内置的超小角散射设置，可以以许多不同的方式进行配置，而无需大量的工作来适应不同的数据收集模式，包括溶液散射，单晶衍射和膜/纤维衍射。一个便携式光纤衍射装置今年建成、调试并有效使用，以补充标准装置。少量的设施表征射束时间用于检查和建立令人满意的射束焦点，除了测试和调试许多新的硬件和软件功能，因为它们的开发已经完成。硬件组件的位置每两周进行评估和重置，包括狭缝刀片、橱柜台和样品位置上游和下游的窗口法兰。射束能量校准作为优化的一部分完成，以便为越来越多地安排在快速周转模式下的用户提供最佳设置。

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. The SSRL Structural Molecular Biology small-angle x-ray scattering facility BL4-2 is a permanent experimental station dedicated to structural biology studies. It receives the central fan of radiation from the new 20-pole 2-T wiggler beam. The wiggler continues to be operated at a reduced wiggler field (0.66T) to manage thermal load on the optic components until the full SPEAR3 upgrade of the beam line optics is completed. State-of-the-art experimental facilities are provided for structural biology studies on proteins, protein assemblies, virus particles, biological fibers and lipid membranes. The in-hutch instrumentation, featuring a pin-hole geometry small angle scattering camera with an automated distance change mechanism and a built-in ultra-small angle scattering setup, can be configured in many different ways without a large amount of effort to accommodate different data collection modes, including solution scattering, single crystal diffraction, and membrane/fiber diffraction. A portable fiber diffraction setup was built, commissioned and effectively used this year to complement the standard setups. A small amount of facility characterization beam time is used to check and establish satisfactory beam focus in addition to testing and commissioning numerous new hardware and software capabilities, as their development is completed. The positions of hardware components is evaluated and reset every two weeks, including slit blades, hutch tables, and window flanges immediately upstream and downstream of the specimen position. Beam energy calibration is done as a part of the optimization, in order to provide the best possible setup to users, who are increasingly scheduled in a fast turn-around mode.