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

Area of Science:

• Physical Chemistry
• Radiation Chemistry
• Biophysics

Background:

• The ratio of ionization to electronic excitation in liquid water radiolysis is poorly understood, impacting predictions of radiation-induced DNA damage.
• This ratio dictates the types of radiolytic species formed, which are critical for cellular damage.
• Accurate estimation is vital for fields ranging from radiation biology to materials science.

Purpose of the Study:

• To estimate the ratio of ionization and electronic excitation in liquid water.
• To investigate the dependence of initial hydrated electron yields on primary electron energy (20 eV-30 keV).
• To provide a more accurate model for secondary electron behavior in liquid water radiolysis.

Main Methods:

• Utilized time-dependent simulation methods combining Monte Carlo code and molecular dynamics.
• Analyzed delocalized and localized components of secondary electrons to determine ionization/excitation ratios.
• Simulated electron interactions with liquid water across a broad energy range.

Main Results:

• Estimated the ionization to electronic excitation ratio based on secondary electron dynamics.
• Investigated primary electron energy dependence of initial hydrated electron yields.
• Yields above 1 keV at 1 ps showed good agreement with literature; yields below 1 keV differed from conventional simulations.

Conclusions:

• The study provides a novel estimation of the ionization/excitation ratio in liquid water radiolysis.
• Femtosecond dynamics Monte Carlo simulations offer accurate initial hydrated electron yields, especially at lower energies.
• Findings will significantly contribute to research fields involving water radiolysis and its biological implications.