Stopping power in heavy tar-gets: lanthanides, transition metals and beyond

A.M.P. MENDEZ; D.M. MITNIK; C. C. MONTANARI; J. PERALTA

Helsinki

Conferencia; 29th international conference on atomic collisions in solids & 11th international symposium on swift heavy ions in matter; 2022

Helsinki University

We present recent calculations for the stopping power of protons in solids composed of heavy atoms. We systematically study lanthanides, from lanthanum to lutetium, transition metals from period 6 of the periodic table and post-transition metals. The electronic stopping power of the targets is described by combining three formalisms. The first one considers a non-perturbative description of the energy loss in the FEG [1], based on the screening potential and the value of rS . The second one uses the dielectric formalism [2] for the stopping in the FEG, in the energy region where plasmon excitations are important. Finally, the third approach describes the bound electron contribution to the stopping by considering relativistic radial orbitals and binding energy calculations. This contribution is calculated with the shellwise local plasma approximation (SLPA) [3]. We modified the usual SLPA to include inter-shell screening, where required, and a local Mermin dielectric function to consider the mean time betweencollisions [4]. In this work, we show that the inclusion of relativistic effects on the bound electrons structure is critical to correctly describe the stopping on these targets. In Fig. 1, we compare our results with available experimental data and the SRIM 2013 calculations for three illustrative examples: H on Pr, W and Pt.