Stopping power in very heavy targets: from lanthanides to post- transition metals

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

Lisbon

Conferencia; The 22nd INTERNATIONAL CONFERENCE ON ION BEAM MODIFICATION OF MATERIALS (IBMM 2022); 2022

Universidade de Lisboa, Lisbon, Portugal

The present state of the stopping data is discussed within the framework of the IAEA stopping database [1]. We focus on the need and importance of reliable values for very heavy targets, such as lanthanides, from lanthanum to lutetium, 6-period transition metals and post-transition metals. Full theoretical calculations are presented for the stopping power of protons in such atomic solids. The importance of relativistic radial orbitals and binding energies is discussed, not only for the deep but also for the outer shells. The electronIc stopping power is described by combining three formalisms: i) the screened potential with cusp condition model [2] (SPCC), which is a non-linear binary formalism for the energy loss in the free electron gas (FEG); ii) the dielectric formalism [3] for the stopping in the FEG (in the energy region where plasmon excitations are important); iii) the shellwise local plasma approximation (SLPA) [4] for the bound electron contribution. The comparison with the well-known SRIM [5], DPASS [6] and CASP [7] results is presented and discussed. We consider that present results are a picture of the state of art of the stopping in lanthanides and post-lanthanides and also states doubts of some of the experimental data in the IAEA database [1] and employed in the SRIM [5] semi-empirical description.