The influence of the scattering law on the radiation damage displacement cascade

Abstract

The Laplace transform technique has been used to develop asymptotic solutions to the integral equations describing the radiation damage displacement cascade, for scattering laws whose symmetrical parts are functions of the relative transferred energy alone. The solutions are presented explicitly for the truncated Coulomb approximation and for a scattering law varying as an inverse power of the transferred energy. The results indicate that the scattering law is rather more significant in determining the number of defects produced during the irradiation of solids than has been previously suggested. The influence of channelling on the cascade is discussed, but appears to be less important than indicated by hard-core scattering models. The asymptotic calculation agrees very well with the experiments of Coltman et al., as well as with the machine calculations of Beeler and Besco.