Atomic processes for the damage on bio-molecules irradiated by XFEL

Moribayashi, Kengo; Kai, Takeshi   

In the analysis of three dimensional structure of bio-molecules by the irradiation of XFEL, the required X-ray flux is so large that the bio-molecules are damaged, that is, the atoms in the bio-molecules are more often ionized. This damage appears as noise for the analysis of three dimensional structure. Therefore, it is indispensable to estimate the damage. We treat C, N, O atoms which are main elements of bio-molecules and some atomic processes such as photo-ionization, Compton scattering, Auger, electron impact ionization, and radiative transition. We have calculated the change of electronic states as a function of time for various parameters such as X-ray flux, X-ray pulses, wavelength of XFEL, and the size of bio-molecules. In our presentation, we will show the results for various parameters and suitable parameters for the experiment of diffraction pattern of bio-molecules.