Fluctuations of point-defect concentrations in metals with cascade-forming irradiation

One source of fluctuations in the point defect concentrations in metals arises from cascades of atomic collisions resulting from irradiation by fast neutrons and heavy ions. These randomly appearing concentrations diffuse to form fluctuating concentration fields of interstitials and vacancies. In this paper the space-time correlations of the fluctuations in point defect concentrations are investigated and the probability distribution functions of the concentrations, which may be used to determine the mean values of the physical properties with nonlinear dependence on the radiation defect concentrations, are calculated.