STOPPING POWER IN HEAVY TARGETS, LANTHANIDES, TRANSITION METALS AND BEYOND

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

Congreso; International Symposium on Swift Heavy Ions in Matter (SHIM) & International Conference on Atomic Collisions in Solids (ICACS); 2022

We present recent calculations for the stopping power of protons in solids composed ofheavy atoms. We systematically study lanthanides, from lanthanum to lutetium, transition metalsfrom period 6 of the periodic table and post-transition metals. The electronic stoppingpower of the targets is described by combining three formalisms. The first one considers anon-perturbative description of the energy loss in the FEG [1], based on the screening potentialand the value of rS. The second one uses the dielectric formalism [2] for the stopping in theFEG, in the energy region where plasmon excitations are important. Finally, the third approachdescribes the bound electron contribution to the stopping by considering relativistic radial orbitalsand binding energy calculations. This contribution is calculated with the shellwise localplasma 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 boundelectrons structure is critical to correctly describe the stopping on these targets. In Fig. 1, wecompare our results with available experimental data and the SRIM 2013 calculations for threeillustrative examples: H on Pr, W and Pt.