欧洲X射线自由电子激光装置中液体弱小角X射线散射信号的脉冲分辨统计恢复
Train-Resolved Statistical Recovery of Weak SAXS Signals in Liquids at the European XFEL
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中文总结 AI 辅助
该研究针对欧洲XFEL高重复率数据集，提出脉冲分辨小角X射线散射方法恢复弱信号，用于L-半胱氨酸水溶液测量。通过比例加偏移拟合等操作，得到依赖透射的残余信号，提高了对弱散射信号的灵敏度。
中文摘要 AI 辅助
我们提出了一种脉冲分辨的小角X射线散射方法，用于从高重复率X射线自由电子激光数据集中恢复弱散射信号，并将其应用于在欧洲X射线自由电子激光装置测量的L-半胱氨酸水溶液。对匹配的半胱氨酸和水脉冲对进行独立的比例加偏移拟合，然后减去透射匹配的水-水对照。0.5M数据集显示了一个可重复的符号变化残余小角X射线散射信号，该信号随入射X射线自由电子激光透射率增加，并且在去除探测器范围的缩放、加性偏移和匹配的水-水对照残余后仍然存在。收敛和块平均分析表明，残余信号随着独立脉冲对的积累而逐渐出现，并且显示出不确定性缩放接近预期的对N的平方根反比依赖。这些结果建立了一个统计上稳健的依赖于透射的残余小角X射线散射贡献，其微观起源仍未解决，同时表明脉冲分辨可观测量与匹配对照相结合可以显著提高高重复率X射线自由电子激光实验中对弱散射信号的灵敏度。
英文摘要
We present a train-resolved SAXS methodology for recovering weak scattering signals from high-repetition-rate XFEL datasets and apply it to aqueous L-cysteine solutions measured at the European XFEL. Independent scale-plus-offset fitting was performed for matched cysteine and water train pairs, followed by subtraction of transmission-matched water--water controls. The 0.5 M dataset reveals a reproducible sign-changing residual SAXS signal that increases with incident XFEL transmission and remains after removal of detector-wide scaling, additive offsets, and matched water--water control residuals. Convergence and block-averaging analyses show that the residual emerges progressively as independent train pairs are accumulated and exhibits uncertainty scaling close to the expected inverse square-root dependence on N. These results establish a statistically robust transmission-dependent residual SAXS contribution whose microscopic origin remains unresolved, while demonstrating that train-resolved observables combined with matched controls can substantially improve sensitivity to weak scattering signals in high-repetition-rate XFEL experiments.
