Incoherent x-ray scattering in single molecule imaging

Abstract

Imaging of the structure of single proteins or other biomolecules with atomic resolution would be enormously beneficial to structural biology. X-ray free-electron lasers generate highly intense and ultrashort x-ray pulses, providing a route towards imaging of single molecules with atomic resolution. The information on molecular structure is encoded in the coherent x-ray scattering signal. In contrast to crystallography there are no Bragg reflections in single molecule imaging, which means the coherent scattering is not enhanced. Consequently, a background signal from incoherent scattering deteriorates the quality of the coherent scattering signal. This background signal cannot be easily eliminated because the spectrum of incoherently scattered photons cannot be resolved by usual scattering detectors. We present an ab initio study of incoherent x-ray scattering from individual carbon atoms, including the electronic radiation damage caused by a highly intense x-ray pulse. We find that the coherent scattering pattern suffers from a significant incoherent background signal at high resolution. For high x-ray fluence the background signal becomes even dominating. Finally, based on the atomic scattering patterns, we present an estimation for the average photon count in single molecule imaging at high resolution. By varying the photon energy from 3.5 keV to 15 keV, we find that imaging at higher photon energies may improve the coherent scattering signal quality.

References in corpus (6)

• Femtosecond Diffractive Imaging with a Soft-X-ray Free-Electron Laser
• A reconstruction algorithm for single-particle diffraction imaging experiments
• Biomolecular imaging and electronic damage using X-ray free-electron lasers
• Multi-wavelength anomalous diffraction at high x-ray intensity
• Orientation Determination in Single Particle X-ray Coherent Diffraction Imaging Experiments
• Effect of two-particle correlations on x-ray coherent diffractive imaging studies performed with continuum models

Cited by in corpus (11)

• Quantum Imaging with Incoherently Scattered Light from a Free-Electron Laser
• Incoherent Diffractive Imaging via Intensity Correlations of hard X-rays
• Theoretical study of electronic damage in single particle imaging experiments at XFELs for pulse durations 0.1 - 10 fs
• Time-resolved ultrafast x-ray scattering from an incoherent electronic mixture
• Fluorescence intensity correlation imaging with high resolution and elemental contrast using intense x-ray pulses
• Theoretical investigation of orbital alignment of x-ray-ionized atoms in exotic electronic configurations
• Probing the Effect of Molecular Structure Saddling on Ultrafast Charge Migration via Time-Resolved X-ray Diffraction
• Comparison of Hartree-Fock and Hartree-Fock-Slater approximations for calculation of radiation damage dynamics of light and heavy atoms in the field of x-ray free electron laser
• Ultraintense, ultrashort pulse x-ray scattering in small molecules
• Compton spectra of atoms at high x-ray intensity
• Single molecule imaging with longer x-ray laser pulses