Monte Carlo Calculation of the Primary Radical and Molecular Yields of Liquid Water Radiolysis in the Linear Energy Transfer Range 0.3–6.5 keV/μm: Application to 137Cs Gamma Rays1

Abstract Meesungnoen, J., Benrahmoune, M., Filali-Mouhim, A., Mankhetkorn, S. and Jay-Gerin, J-P. Monte Carlo Calculation of the Primary Radical and Molecular Yields of Liquid Water Radiolysis in the Linear Energy Transfer Range 0.3–6.5 keV/μm: Application to 137Cs Gamma Rays. Monte Carlo simulations of the radiolysis of neutral liquid water and 0.4 M H2SO4 aqueous solutions at ambient temperature are used to calculate the variations of the primary radical and molecular yields (at 10–6 s) as a function of linear energy transfer (LET) in the range ∼0.3 to 6.5 keV/μm. The early energy deposition is approximated by considering short (∼20–100 μm) high-energy (∼300–6.6 MeV) proton track segments, over which the LET remains essentially constant. The subsequent nonhomogeneous chemical evolution of the reactive species formed in these tracks is simulated by using the independent reaction times approximation, which has previously been used successfully to model the radiolysis of water under various conditions. The...