ENERGY LOSS STRAGGLING OF SWIFT H, HE AND LI IONS IN DIFFERENT SOLIDS

MONTANARI C. C.; MIRAGLIA J. E.; SANTIAGO HEREDIA-AVALOS; RAFAEL GARCIA-MOLINA; ISABEL ABRIL

Rosario

Congreso; XXIV International Conference on Photonic, Electronic and Atomic Collisions; 2005

XXIV International Conference on Photonic, Electronic and Atomic Collisions

We present theoretical results of energy loss straggling of swift H, He and Li ions moving through thin C, Al, Si and Cu foils. Two models are compared, the MELF-GOS and the SLPA. In the former, the dielectric response of the target outer-shell electrons is expressed as a sum of Mermin  type functions (MELF) which fit the data of the energy loss function. The excitation of inner-shell electrons is given by their generalized oscillator strength (GOS).  On the other hand, the SLPA works within the assumptions of the local plasma approximation (LPA), in a shell to shell way, employing Hartree-Fock densities of each shell separately. We obtain very good accord between the two independent models. The comparison with the experimental data is good, especially for H ions. In the case of He and Li ions the spread of data is important and the theoretical curves tend to underestimate this values