Ultrafast Structural Dynamics in Systems with Limited Long-Range Order through Pair Distribution Function Analysis

Abstract

　Pump-probe Pair Distribution Function (PDF) techniques to capture ultrafast structural dynamics in systems with limited long-range order at XFELs have seen little progress due to limited spatial resolution (Q_max). To increase the Q-coverage, a detector setup was conceptualized, and a data treatment pipeline was developed. Unfortunately, several critical issues were encountered during the experiment, causing the Q_max-value to improve only marginally compared to previous records (~10 Å^-1 compared to ~8 Å^-1).[1] Although this hindered the extraction of reliable time-resolved results, observations of structural changes from pump-probe PDF experiments at SACLA seem to be within reach if the experimental conditions can be optimized slightly.[2]