Effects of electron-impact ionization on the damage to biomolecules irradiated by XFEL

Kai, Takeshi   ; Moribayashi, Kengo

In X-ray free electron laser applications, the analysis of the three-dimensional structure of single bio-molecules is one of the critical issues. In this case, target samples are damaged by high-intense X-rays as well as ionization processes by electron impact. The processes are very significant to investigate the damage in the electron density in the bio-molecule since secondary electrons produced by the high-intense X-rays make the targets ionized again. Available ionization-cross sections for inner-shell excited states produced by high-intense X-rays have never been reported. We address ionization processes by electron impact for the ground states as well as those for the inner-shell excited states to investigate the damage of the target samples. We will discuss the effect of electron-impact ionization for the damage by solving rate equations using the present results.