| Abstract: | - A dispersive model of radical accumulation in irradiated solids is discussed by the example of hexagonal ice (Ih) and cubic ice (Ic) obtained by annealing of hyperquenched glassy water at 160 K. The model assumes that radical production upon  -irradiation is accompanied by their second-order decay, which proceeds according to dispersive kinetics with the time-dependent specific reaction rate k(t) = Bt -1, where B = constant and is the dispersion parameter equal to 0.40 for both the hexagonal and cubic ices. The radicals, OH in Ih, and OH plus HO2 in Ic are produced at the same rate upon -irradiation. The observed enhancement of radical accumulation in ice Ic in comparison with Ih is due to the marked decrease of radical recombination in ice Ic. This is rationalized by the hindrance of radical transport in the lattice of ice Ic containing substantial amounts of Bjerrum-type L-defects. |
