Stopping power in heavy atoms, the role of 4f electrons

C. C. MONTANARI; A. M. P. MENDEZ; D. M. MITNIK; J. E. MIRAGLIA

Cluj-Napoca

Simposio; 27th International Symposium on Ion-Atom Collisions; 2021

Babeș-Bolyai University

We present recent theoretical calculations for the stopping power of protons in solid Hf, Ta, andPt. We compute the stopping power of these heavy post-lanthanide metals considering three differentmethods. First, we use a non-perturbative description for the energy loss in the FEG [1] based on thescreening potential and the value of rS. The second model employs the dielectric formalism [2] for thestopping of the FEG in the energy region where plasmon excitations are important. The third methodconsiders a detailed description of the electronic structure of the bound electrons –wave functions andbinding energies– using relativistic solutions of the Dirac equation. The stopping of bound electrons(1s-4 f ) is calculated using these structure calculations and the shellwise local plasma approximation(SLPA) [3, 4]. We modified the SLPA to include inter-shell screening (5p-4 f ) and a local Mermindielectric function [2]. Present results and the comparison with available experimental data and withSRIM 2013 are displayed in Figure 1. The differences with SRIM predictions are noticeable.