Author: Yefanov, O.
Paper Title Page
MOP082 Perspectives for Imaging Single Protein Molecules with the Present Design of the European XFEL 238
  • G. Geloni
    XFEL. EU, Hamburg, Germany
  • V. Kocharyan, E. Saldin, S. Serkez, I. Zagorodnov
    DESY, Hamburg, Germany
  • O. Yefanov
    CFEL, Hamburg, Germany
  European XFEL aims to support imaging and structure determination of biological specimens between less than 0.1 microns and 1 micron size with working photon energies between 3 keV and 16 keV. This wide operation range is a cause for challenges to the focusing optics. A long propagation distance of about 900 m between x-ray source and sample leads to a large lateral photon beam size at the optics. Due to the large divergence of nominal X-ray pulses with durations shorter than 10 fs, one suffers diffraction from mirror apertures, leading to a 100-fold decrease in fluence at photon energies around 4 keV, which seem ideal for imaging of single biomolecules. Moreover, the nominal SASE1 is very far from the level required for single particle imaging. Here we show how it may be possible to optimize the SPB instrument for single biomolecule imaging with minimal additional costs and time, achieving diffraction without destruction at near-atomic resolution with 1013 photons in a 4 fs pulse at 4 keV photon energy and in a 100 nm focus, corresponding to a fluence of 1023 ph/cm2. This result is exemplified using the RNA Pol II molecule as a case study.