Time-dependent yield of [rad]OH radicals in the low linear energy transfer radiolysis of water between 25 and 350 °C

Abstract

Monte Carlo simulations were used to calculate time-dependent yields of OH radicals in the low-LET radiolysis of water from 25 to 350°C. The excellent agreement found, at 25°C, with bothOH yields directly measured in picosecond pulse radiolysis and those inferred from scavenger experiments, resolves a long-standing problem in models of the radiation chemistry of water concerning short-time OH decay kinetics. Above ∼200°C, the OH yields markedly increased at long times due to the reaction H+H2O→H2+OH. Our results suggest a way to assess this reaction’s rate constant, which is still controversial.