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The upgrade of the laser pump time‐resolved X‐ray probes, namely time‐resolved X‐ray absorption spectroscopy (TR‐XAS) and X‐ray diffraction (TR‐XRD), implemented at the Beijing Synchrotron Radiation Facility, is described. The improvements include a superbunch fill, a high‐efficiency fluorescence collection, an efficient spatial overlap protocol and a new data‐acquisition scheme. After upgrade, the adequate TR‐XAS signal is now obtained in a 0.3 mM solution, compared with a 6 mM solution in our previous report. Furthermore, to extend application in photophysics, the TR‐XAS probe is applied on SrCoO2.5 thin film. And for the first time, TR‐XAS is combined with TR‐XRD to simultaneously detect the kinetic trace of structural changes in thin film. [ABSTRACT FROM AUTHOR]

A new setup and commissioning of transient X-ray absorption spectroscopy are described, based on the high-repetition-rate laser pump/X-ray probe method, at the 1W2B wiggler beamline at the Beijing Synchrotron Radiation Facility. A high-repetition-rate and high-power laser is incorporated into the setup with in-house-built avalanche photodiodes as detectors. A simple acquisition scheme was applied to obtain laser-on and laser-off signals simultaneously. The capability of picosecond transient X-ray absorption spectroscopy measurement was demonstrated for a photo-induced spin-crossover iron complex in 6 m M solution with 155 kHz repetition rate. [ABSTRACT FROM AUTHOR]

The implementation of a laser pump/X-ray probe scheme for performing picosecond-resolution X-ray diffraction at the 1W2B wiggler beamline at Beijing Synchrotron Radiation Facility is reported. With the hybrid fill pattern in top-up mode, a pixel array X-ray detector was optimized to gate out the signal from the singlet bunch with interval 85 ns from the bunch train. The singlet pulse intensity is ∼2.5 × 10(6) photons pulse(-1) at 10 keV. The laser pulse is synchronized to this singlet bunch at a 1 kHz repetition rate. A polycapillary X-ray lens was used for secondary focusing to obtain a 72 µm (FWHM) X-ray spot. Transient photo-induced strain in BiFeO3 film was observed at a ∼150 ps time resolution for demonstration.