Development of high-sensitivity data collection system for time-resolved x-ray diffraction measurement at the photon factory advanced ring.

We have developed a high-sensitivity data collection and measurement system for time-resolved x-ray diffraction experiments at the Photon Factory Advanced Ring. Use of x-ray pixel array photon counting detectors provides a suitable improvement in measurement sensitivity when compared to existing systems. The system is equipped with a laser that operates with a variable repetition rate, thus making it highly suitable for synchronization with the synchrotron x-ray source and the electronic gating detectors. Here, we present the measurement system configuration, provide details of the data collection scheme used for the single and double electronic gating features, and then demonstrate the capabilities of the system by measuring the transient dynamics of a weak x-ray diffraction peak that is attributed to the modulation of a long-range dimerized structural ordering via laser excitation in vanadium dioxide. The implementation of the system's output opens the possibility of performing ultrafast time-resolved x-ray measurements, even for target substances and phenomena that are difficult to measure when using conventional systems because of their weak signals, and this may provide a route toward ultrafast control of the physical properties of materials.