Structural Dynamics at LCLS

摘要：TR&D-2 TR&D-2解决了LCLS X射线自由电子激光数据收集的样品输送挑战。高 用于探测样品结构的强度X射线自由电子激光束在曝光后会破坏样品 一个X射线脉冲因此，LCLS的实验需要一个样品输送系统， 可以在每次X射线脉冲之间更换损坏的样品。水晶注射器是第一个 用于连续飞秒衍射的晶体输送方法，通常用于X射线衍射 自由电子激光设施，因为他们可以有效地提供大量的晶体，减少背景 分散，并使新的类的时间分辨的研究。进样器产生一个薄的 通过小孔喷射悬浮液而形成的晶体（或样品溶液）流。x射线 高重复率的脉冲询问晶体流，并产生衍射图案 每次晶体和X射线脉冲重合虽然可以收集串行数据， 低温快速扫描固定目标系统，注射器可以补充空间 以更快的速率进行温度采样。此外，许多生物医学问题需要 进样器提供的独特功能，包括使用快速混合来研究 生物分子动力学 TR&D-2专注于推进基于注射器的样品输送方法，以实现研究 遵循DBP主题，特别是解决膜蛋白和其他蛋白质的新结构 辐射敏感的生物分子，并使蛋白质动力学的研究，包括那些 金属酶这将通过发展远程数据访问能力来实现 收集脂质立方相（LCP）和其他粘性介质样品，以及通过 对快速混合注射器进行全面测试和优化。TR&D-2旨在最大限度地提高 独特的LCLS光束的使用效率，促进更多的生物医学 新的科学发现和科学发现。

ABSTRACT: TR&D-2 TR&D-2 tackles the challenges of sample delivery for data collection at the LCLS X-ray FEL. High intensity X-ray FEL beams used to probe sample structure will destroy the sample after exposure to a single X-ray pulse. As a result, experiments at LCLS require a sample delivery system that can replace the damaged sample between every X-ray pulse. Crystal injectors were the first crystal delivery method used for serial femtosecond diffraction and are commonly used at X-ray FEL facilities because they can efficiently deliver a large number of crystals, reduce background scattering and enable new classes of time resolved studies. Sample injectors produce a thin stream of crystals (or sample solution) by ejecting a suspension through a small orifice. X-ray pulses at a high repetition rate interrogate the crystal stream and a diffraction pattern is produced each time a crystal and an X-ray pulse coincide. While it is possible to collect serial data at cryogenic temperatures with rapid scanning fixed target systems, injectors can replenish room temperature samples at even faster rates. Furthermore, many biomedical problems require the unique features offered by sample injectors including methods that use rapid mixing to study biomolecular dynamics. TR&D-2 focuses on advancing injector-based sample delivery methods to enable research following the DBP themes, specifically, solving new structures of membrane proteins and other radiation sensitive biomolecules and enabling the study of protein dynamics including those of metalloenzymes. This will be achieved via the development of remote access capabilities for data collection for Lipidic Cubic Phase (LCP) and other viscous media samples, as well as through the thorough testing and optimization of rapid mixing injectors. TR&D-2 aims to maximize the efficiency in the use of the unique LCLS beam, promoting greater access to biomedical community and new scientific discovery.