Low-signal limit of X-ray single particle diffractive imaging

• DOI: 10.1364/oe.27.037816
• Publication Date: 2019-12-12T20:09:12Z
• Authors: Kartik Ayyer; Andrew J. Morgan; Andrew Aquila; Hasan DeMirci; Brenda G. Hogue; Richard A. Kirian; P. Lourdu Xavier; Chun Hong Yoon; Henry N. Chapman; Anton Barty
• Keywords: 0301 basic medicine; Photons; 0303 health sciences; Image and Video Processing (eess.IV); FOS: Physical sciences; Optics; Electrical Engineering and Systems Science - Image and Video Processing; Bayesian networks; Photons; Viruses; 530; 03 medical and health sciences; Bayesian networks; Viruses; FOS: Electrical engineering, electronic engineering, information engineering; info:eu-repo/classification/ddc/530; Physics - Optics; Optics (physics.optics)

An outstanding question in X-ray single particle imaging experiments has been the feasibility of sub 10-nm-sized biomolecules under realistic experimental conditions where very few photons are expected to be measured a snapshot and instrument background may significant relative scattering. While analyses simulated data have shown that determination an average image should feasible using Bayesian methods such as EMC algorithm, this yet demonstrated containing non-isotropic background, sample variability other factors. In work, we show orientation phase retrieval steps work at photon counts diluted signal levels one expects from smaller molecules or with weaker pulses, measurements 60-nm PR772 viruses. Even when is reduced fraction little 1/256, virus electron density determined ab initio phasing almost same quality high-signal data. However, still limited by total number patterns collected, which soon mitigated advent high repetition-rate sources like European XFEL LCLS-II.