The electronic Stopping Power of heavy targets

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

Advances in Quantum Chemistry

ELSEVIER INC.

Año: 2022; p. 157 - 175

The aim of this work is to face the challenge of describing the stopping power in heavytransition and posttransition metal solids in an extended energy range. The presentstudy examines the stopping of hydrogen in Hf, W, Pb, and Bi. The electronic structuredescription of the targets requires solving the many-electron Dirac Hamiltonian. Weinquire the influence of employing various relativistic approximations, and its effecton the energy loss. The theoretical model of the stopping power considers separatelythe valence electrons of the metal-accounted for as a free-electron gas and the boundelectrons. The former are described using a nonperturbative binary screening potentialor the dielectric formalism, depending on the energy regions and plasmon excitationthreshold. For the later, the approach uses the dielectric formalism for each subshell bymeans of the shellwise local plasma approximation. We inspect the importance of accuratelydescribing the 4f and 5d electrons, the spin–orbit split, the intra- and intershellscreening among electrons, and the different quantum dielectric response functions.The present results correctly describe the stopping cross sections in comparison withthe data available, the theoretical models DPASS and CasP, and the semiempiricalSRIM. Based on these results, we analyze the state of art of the experimental valuesand suggest the need for new measurements in certain energy ranges and targets.