Theoretical developments for the stopping power in an extended energy range

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

Caen

Conferencia; 10th International Symposium on Swift Heavy Ions in Matter and 28th International Conference on Atomic Collisions in Solids; 2018

ICACS

We present full theoretical calculations for the stopping power of heavy charged projectilesin multi-electronic targets. We combine a recent non-perturbative model for the free electrongas [1] and the SLPA for the inner-shells [2]. We will show our recent results for stopping ofantiprotons in C, Si and Al at low impact energy, and for protons in Al,Si,Ti,Ge, and Pb inan extended energy region.We will also present recent calculations for Mo,Nb,Pd,Ag,Gd,Hf,Ta. These very heavytargets require solving the relativistic-Dirac equation to obtain the wave functions andbinding energies for the ground state. To this end, we used the HULLAC code package [3],which allows one to obtain accurate relativistic one-electron orbitals and multiconfigurationbound states and energies. The calculations are based on first-order perturbation theory witha central field, including the contribution from the Breit interaction and quantumelectrodynamics corrections. The detailed energy levels are computed using the RELACcode [4]. This model consists in minimizing the first-order relativistic energy of a given setof configurations for a parametric analytical function for the screening charge distribution.Although this code was developed for solving highly charged ions, it can be successfullyemployed for neutral atoms, such as the ones presented here. The computed binding energiesof the bound orbitals are compared with the experimental values in solid compiled byWilliams [5]. These results are combined with the SLPA to obtain the inner-shellscontribution to the electronic stopping, which is the relevant contribution for energies abovethe stopping maximum.