A collective model for inner shell ionization of very heavy targets

C. C. MONTANARI; D.M. MITNIK; J. E. MIRAGLIA

Radiation Effects & Defects in Solids

Taylor & France

Lugar: xx; Año: 2022; p. 338 - 345

We present a theoretical study of the ionization of inner shells, such as L and M shells of Au, Pb and Bior K-shell of Sb. The ionization is described using a collective response model, the shellwise local plasmaapproximation (SLPA). This model deals with each sub-shell of target electrons as an inhomogeneouselectron gas with an ionization threshold. No parameters are included, just the theoretical wave functionsof the ground state and the binding energies. The validity range is that of the perturbative approximation,high energies and asymmetric projectile target relation. In the case of Sb, known Hartree–Fock wavefunctions and energies are used. Instead, for Au, Pb and Bi, they were obtained in fully relativistic wayby solving numerically the Dirac equation. The SLPA describes well the experimental data for K-shellionization of Sb by O and F positive ions. However, it underestimates the data for C or lighter ions. Goodresults are obtained for M-shell ionization of Au and Bi above 2MeV/amu, and for L-shell ionization ofAu and Pb above 10MeV/amu. For L- and M-shells, the SLPA tends to underestimate the data for energiesbelow the range of validity of the model but approaches the experimental data for higher energies.