Improved methods for calculating electron, positron, and photon radiation-induced displacement damage cross sections

Radiation damage is a key challenge for materials. Accurate evaluation of radiation damage is a starting point for investigating the behaviors of materials used in a radiation environment. The present work proposes improved methods for calculating the primary radiation damage cross sections induced by light particles, including electrons, positrons, and photons. The main improvements compared with previous methods are: (1) accurate Mott cross section rather than the McKinley-Feshbach analytical approach is used for electron and positron scattering; (2) data and methods recommended by the International Commission on Radiation Unit and measurements (ICRU) are systematically applied for computing the stopping powers of electron and positron; (3) accurate differential cross section by combining different models instead of some simple approaches is used for pair production. The electron, positron, and photon irradiation-induced displacement cross sections for various important elements covering a large range of atomic numbers (from Li to U) are computed with the improved methods for energy up to 100 MeV. The calculated displacement cross sections are also tabulated so that they can be simply used for further applications.