Abstract
The paper considers a new approach to approximation expressions for integral sections of interaction and for approximation coefficients included in expressions for cascade-probability functions (CPF), spectra of primary knocked-on atoms (PNA) and the concentration of radiation defects in materials irradiated with charged particles, namely electrons, protons, alpha particles and ions. The obtained approximations made it possible to design the mathematical models of cascade-probability functions taking into account energy losses for electrons, protons, alpha particles and ions. The integral sections of interaction, penetration depths were calculated, the approximation expressions were chosen, and the approximation coefficients for the above particles were found. Recurrence ratios were derived to obtain CPF. The choice of an approximation expression and finding of approximation coefficients was compared with the earlier process using different software packages. It is apparent that that the use of modern algorithms considerably simplifies this process.