A study of the charge state approach to the stopping power of MeV B, N and O ions in carbon

The charge state approach has been applied to describe the electronic stopping powers of swift O, N and B ions in carbon. According to the charge state model, the contributions to the electronic stopping power of energetic projectiles passing through solid targets are due to collisional interactions and the charge-exchange process. The definition of fractional effective charge from Brandt and Kitagawa has been introduced into the model. This approach requires knowledge of the equilibrium charge state distributions and of the charge-exchange cross sections for both electronic capture and loss processes. Both measured data and empirical calculations of the equilibrium charge state fraction are used in the study, and the electronic capture cross sections are obtained with the Eikonal Brinkman–Kramers approximation (EBK). By comparing the numerical results with the latest experimental data as well as empirical values, it is shown that the present approach slightly overestimates the energy loss at the intermediate velocity region.