Rolles Daniel, Boll Rebecca, Erk Benjamin, Rompotis Dimitrios, Manschwetus Bastian
J.R. Macdonald Laboratory, Department of Physics, Kansas State University;
Deutsches Elektronen-Synchrotron DESY; European XFEL GmbH.
J Vis Exp. 2018 Oct 23(140):57055. doi: 10.3791/57055.
This protocol describes key steps in performing and analyzing femtosecond pump-probe experiments that combine a femtosecond optical laser with a free-electron laser. This includes methods to establish the spatial and temporal overlap between the optical and free-electron laser pulses during the experiment, as well as important aspects of the data analysis, such as corrections for arrival time jitter, which are necessary to obtain high-quality pump-probe data sets with the best possible temporal resolution. These methods are demonstrated for an exemplary experiment performed at the FLASH (Free-electron LASer Hamburg) free-electron laser in order to study ultrafast photochemistry in gas-phase molecules by means of velocity map ion imaging. However, most of the strategies are also applicable to similar pump-probe experiments using other targets or other experimental techniques.
本协议描述了进行和分析飞秒泵浦-探测实验的关键步骤，该实验将飞秒光学激光器与自由电子激光器相结合。这包括在实验过程中建立光学和自由电子激光脉冲之间的空间和时间重叠的方法，以及数据分析的重要方面，如到达时间抖动校正，这对于获得具有最佳时间分辨率的高质量泵浦-探测数据集是必要的。这些方法在汉堡自由电子激光（FLASH）上进行的一个示例性实验中得到了验证，该实验旨在通过速度成像离子成像研究气相分子中的超快光化学。然而，大多数策略也适用于使用其他目标或其他实验技术的类似泵浦-探测实验。
