A collective model for inner-shell ionization of very heavy targets

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

RADIATION EFFECTS AND DEFECTS IN SOLIDS

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2011 vol. 166 p. 338 - 345

1042-0150

We present a theoretical study of the ionization of inner shells, such as L and M shells of Au, Pb and Bi or K-shell of Sb. The ionization is described using a collective response model, the shellwise local plasma approximation (SLPA). This model deals with each sub-shell of target electrons as an inhomogeneous electron gas with an ionization threshold. No parameters are included, just the theoretical wave functions of 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 wave functions and energies are used. Instead, for Au, Pb and Bi, they were obtained in fully relativistic way by solving numerically the Dirac equation. The SLPA describes well the experimental data for K-shell ionization of Sb by O and F positive ions. However, it underestimates the data for C or lighter ions. Good results are obtained for M-shell ionization of Au and Bi above 2MeV/amu, and for L-shell ionization of Au and Pb above 10MeV/amu. For L- and M-shells, the SLPA tends to underestimate the data for energies below the range of validity of the model but approaches the experimental data for higher energies/amu, and for L-shell ionization of Au and Pb above 10MeV/amu. For L- and M-shells, the SLPA tends to underestimate the data for energies below the range of validity of the model but approaches the experimental data for higher energies/amu. For L- and M-shells, the SLPA tends to underestimate the data for energies below the range of validity of the model but approaches the experimental data for higher energies