Nunes J P F, Ledbetter K, Lin M, Kozina M, DePonte D P, Biasin E, Centurion M, Crissman C J, Dunning M, Guillet S, Jobe K, Liu Y, Mo M, Shen X, Sublett R, Weathersby S, Yoneda C, Wolf T J A, Yang J, Cordones A A, Wang X J
Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.
SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Struct Dyn. 2020 Mar 9;7(2):024301. doi: 10.1063/1.5144518. eCollection 2020 Mar.
The conversion of light into usable chemical and mechanical energy is pivotal to several biological and chemical processes, many of which occur in solution. To understand the structure-function relationships mediating these processes, a technique with high spatial and temporal resolutions is required. Here, we report on the design and commissioning of a liquid-phase mega-electron-volt (MeV) ultrafast electron diffraction instrument for the study of structural dynamics in solution. Limitations posed by the shallow penetration depth of electrons and the resulting information loss due to multiple scattering and the technical challenge of delivering liquids to vacuum were overcome through the use of MeV electrons and a gas-accelerated thin liquid sheet jet. To demonstrate the capabilities of this instrument, the structure of water and its network were resolved up to the hydration shell with a spatial resolution of 0.6 Å; preliminary time-resolved experiments demonstrated a temporal resolution of 200 fs.
将光转化为可用的化学能和机械能对于多种生物和化学过程至关重要，其中许多过程发生在溶液中。为了理解介导这些过程的结构 - 功能关系，需要一种具有高空间和时间分辨率的技术。在此，我们报告了一种用于研究溶液中结构动力学的液相兆电子伏特（MeV）超快电子衍射仪器的设计和调试。通过使用MeV电子和气体加速的薄液膜射流，克服了电子穿透深度浅以及多重散射导致的信息损失和将液体输送到真空的技术挑战所带来的限制。为了展示该仪器的能力，水及其网络的结构在高达水化层的范围内以0.6埃的空间分辨率得到解析；初步的时间分辨实验证明了200飞秒的时间分辨率。
