An Initial value of hydrated electrons updated by a dynamic Monte Carlo simulation

Kai, Takeshi   ; Toigawa, Tomohiro   ; Matsuya, Yusuke*  ; Hirata, Yuho   ; Tsuchida, Hidetsugu*; Yokoya, Akinari*

Water is one of the most interesting subjects of research in life sciences and the power industry, yet the ratio of ionization to electron excitation in water radiolysis remains unclear. This ratio determines the yield of radiolytic chemical species, but currently, it is parameterized. We challenged this long-standing fundamental scientific problem using computer simulations and successfully evaluated the primary electron energy dependence of the initial yield of hydrated electrons without relying on conventional model parameters. Contrary to conventional concepts, this study revealed that defining cross sections for water ionization and electron excitation is unnecessary. Instead, the dynamic motion calculation of secondary electrons generated by water radiolysis determines the final ratio of ionization to excitation. Our novel analytical approach is expected to gradually recognized as a new method for analyzing general liquid radiolysis.