Diffraction intensity of biomolecules with radiation damage by XFEL irradiation

We calculated diffraction intensity of biomolecule with radiation damage by x-ray free electron lasers (XFEL) irradiation using a developed model for radiation-damage considering photoionization. Compton scattering, Auger decay, electron-impact ionization and electric field ionization. We performed the parameter survey for the radiation damage with various XFEL parameters and target radius of clusters. In the case of the x-ray energy 12 keV, we found that the upper limit of incident x-ray flux was in the order of 1019 photons/mm2, and the obtained average number of photons for elastic scattering at 0.1 or more region of momentum transfer was in the order of 10-2 photons/pixel even if pulse width became 1 fs. (author)