Fluctuation effects in the solid-phase kinetics of diffusion-controlled radiation-chemical processes: A Monte Carlo simulation

The model problem of the recombination of free radicals was considered with consideration for the following three types of events: the generation (homogeneous and inhomogeneous), migration, and recombination of particles of the same type in a cubic lattice. A simple formula, which was checked using the Monte Carlo method, was proposed to describe this kinetics with an inhomogeneous initial distribution. This model was used to describe experimental data on the recombination of free radicals in a real system of γ-irradiated ammonia. Reasonable values were obtained for the characteristic spur radius and diffusion coefficient. It was found that the character of fluctuation noise in the system depends on the mechanism of elementary processes occurring in this system; consequently, it can be a source of information on process parameters.