A high energy barrier to charge recombination in ionized water vapor

Abstract

A quantitative kinetic theory has been developed to explain the results of experimental observation of the abnormally intense clustering of water molecules in the vapor phase in an ionizing radiation field at a moderate dose rate. The recombination is impeded because of the hydration of ion pairs and the formation of an abnormally high energy barrier (∼100 k B T) in molecular clusters. The buildup of the clusters of water molecules stabilized in the electric field of ion pairs results in a dramatic enhancement of the effect of ionizing radiation on the electric properties of the vapor. The values of the coefficients to the rate equation of ionization-recombination equilibrium were calculated on the molecular level by computer simulation of the hydration of the H3O+(H2O) n OH− ion pair using the detailed model of intermolecular interactions.