Liquid-phase mega-electron-volt ultrafast electron diffraction
Liquid-phase mega-electron-volt ultrafast electron diffraction
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DOI：
10.1063/1.5144518
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发表时间：
2020-03-01
影响因子：
2.8
通讯作者：
Wang, X. J.
中科院分区：
文献类型：
--
作者：
Nunes, J. P. F.;Ledbetter, K.;Wang, X. J.
光到有用的化学和机械能的转换是几个生物和化学过程的关键，其中许多过程发生在溶液中。为了理解这些过程中的结构-功能关系，需要一种具有高空间和时间分辨率的技术。本文报道了一台用于研究溶液结构动力学的兆电子伏特(MeV)超快电子衍射仪的设计和调试。通过使用MeV电子和气体加速的薄液片射流，克服了电子穿透深度浅和多次散射造成的信息损失造成的限制，以及将液体输送到真空的技术挑战。为了验证该仪器的性能，水的结构和网络结构被分辨到空间分辨率为0.6埃的三阶水化壳层；初步的时间分辨实验表明时间分辨率为200fs。
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 the3 rd hydration shell with a spatial resolution of 0.6 angstrom; preliminary time-resolved experiments demonstrated a temporal resolution of 200 fs.