Ultrafast structural dynamics using time-resolved x-ray diffraction driven by relativistic laser pulses* *Project supported by the National Key R&D Program of China (Grant No. 2017YFA0403301), Science Challenge Project (Grant No. TZ2018005), the National Natural Science Foundation of China (Grant Nos. 11991073, 11721404, 11805266, 11905289, and 61975229), and Key Program of Chinese Academy of Sciences (Grant Nos. XDA25030400 and XDB17030500).

Abstract

Based on a femtosecond laser plasma-induced hard x-ray source with a high laser pulse energy (> 100 mJ) at 10 Hz repetition rate, we present a time-resolved x-ray diffraction system on an ultrafast time scale. The laser intensity is at relativistic regime (2 × 1019 W/cm2), which is essential for effectively generating Kα source in high-Z metal material. The produced copper Kα radiation yield reaches to 2.5 × 108 photons/sr/shot. The multilayer mirrors are optimized for monochromatizating and two-dimensional beam shaping of Kα emission. Our experiment exhibits its ability of monitoring the transient structural changes in a thin film SrCoO2.5 crystal. It is demonstrated that this facility is a powerful tool to perform dynamic studies on samples and adaptable to the specific needs for different particular applications with high flexibility.