Deceleration process of Auger electrons in liquid water calculated by a dynamic Monte Carlo method for prediction of DNA damage induction

Kai, Takeshi   ; Yokoya, Akinari; Ukai, Masatoshi*; Fujii, Kentaro; Watanabe, Ritsuko

We simulated the electron deceleration for initial electron energies ranging from 0.1 eV to 100 keV using a dynamic Monte Carlo code. The thermalization period calculated is longer than that previously predicted. Thus the thermalization process significantly contributes the series of processes, from ionization to hydration. Particularly for the electron with incident energy of 1 eV, the temporal evolution of total track length, mean traveling distance and energy distributions of the decelerating electron were investigated. Pre-hydration and thermalization period were estimated to be 50 and 220 fs, respectively, indicating that the initial pre-hydration begins before or competitively with thermal equilibrium. These results suggest that the pre-hydrated electrons play an important role in the very early process of multiple DNA damage induction.