Inner-shell ionization of very heavy targets

C.C. MONTANARI, D.M. MITNIK AND J.E. MIRAGLIA

Itapema

Congreso; 20th International Conference on Ion Beam Analysis; 2011

International Atomic Energy Agency (IAEA) and Ion Implantation Laboratory, UFRGS, Porto Alegre - Brazil.

We present fully-theoretical calculations of inner-shell ionization of targets such as Au, Pb and  Bi, for which wave functions and binding energies are governed by the Dirac equation [1], and  for  heavy but not  relativistic targets, such as Cu and Sb. In all the cases ionization cross  sections are calculated within the dielectric formalism by using the Levine-Louie Shellwise Local  Plasma Approximation (SLPA). This model approaches the response of the bound electrons as an electron gas of local density given by the electronic density of each sub-shell. On the other  hand, the ionization threshold is considered explicitly by using  the Levine-Louie correction to  Lindhard dielectric function. Different energies and ions are considered, trying to describe the experimental data within the  limits of the theoretical approach. In the case of L-shell and M-shell of Au, Pb and Bi it means  tens to a few MeV/amu [2], in the case of Cu and Sb these energies correspond to  K-shell  ionization [3]. Results show good performance for the most asymmetric  projectile-target  relations and for impact velocities above or of the order of the velocity of the electrons in the sub  shell. [1]  C. C. Montanari, C. D. Archubi, D, M, Mitnik and J. E. Miraglia, Phys. Rev. A 79 (2009)  032903. [2] M. Czarnota et al, Phys. Rev. A 79 (2009) 032710. [3] Y. P. Singh et al, Phys. Rev. A 74  (2006) 052714; Phys. Rev. A 64 (2001) 012718.