论文标题
X射线激光器上的单粒子成像的Ptychographic波前表征
Ptychographic wavefront characterisation for single-particle imaging at X-ray lasers
论文作者
论文摘要
特征良好的波前对于许多X射线自由电子激光（XFEL）实验很重要，尤其是对于单粒子成像（SPI），其中单个生物分子随机对高度关注的女性脉冲的纳米区域随机采样。我们展示了基于混合态Ptychography的Kirkpatrick-Baez（KB）镜子的重点，以Xfel脉冲的集合进行了高分辨率的多面波前成像，这种方法使我们推断并减少了实验性不稳定的来源。从回收的波前剖面中，我们表明，尽管局部光子通量校正至关重要，对于SPI来说可能是可能的，但少量的相位倾斜可能没有影响。我们的详细表征将有助于解释过去和将来的SPI实验的数据，并为实验设计和重建算法提供进一步改进的基础。
A well-characterised wavefront is important for many X-ray free-electron laser (XFEL) experiments, especially for single-particle imaging (SPI), where individual bio-molecules randomly sample a nanometer-region of highly-focused femtosecond pulses. We demonstrate high-resolution multiple-plane wavefront imaging of an ensemble of XFEL pulses, focused by Kirkpatrick-Baez (KB) mirrors, based on mixed-state ptychography, an approach letting us infer and reduce experimental sources of instability. From the recovered wavefront profiles, we show that while local photon fluence correction is crucial and possible for SPI, a small diversity of phase-tilts likely has no impact. Our detailed characterisation will aid interpretation of data from past and future SPI experiments, and provides a basis for further improvements to experimental design and reconstruction algorithms.
