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Energy-loss measurements and theoretical calculations for Be and B ions in Zn are presented. The experimental ion energies range from 40 keV/u to 1 MeV/u, which includes the energy-loss maximum and covers a lack of experimental data for these systems from intermediate to high energies. The measurements were performed using the Rutherford backscattering technique. The ab initio calculations are based on the extended Friedel sum rule–transport cross-section method for the valence electrons and the Shellwise local plasma approximation for the bound electrons. A comparison of these calculations to the present experimental data for Be and B and previous values for H, He, and Li ions on the same target is included. This confirms the applicability of the employed theoretical framework also for ions of intermediate atomic number.

We have performed a combined theoretical and experimental study of the energy loss of Li ions in Zn, on a wide range of energies, together with comparative studies for H and He ions on the same target. By using Zn films and the Rutherford backscattering technique, we were able to determine the stopping power for Li ions in the (0.3 to 5) MeV energy interval. The experimental results cover an energy range which includes the maximum of the stopping power. The values obtained agree well with previous measurements performed in a limited energy interval and with the semiempirical code SRIM 2006. On the other hand, we have performed ab initio theoretical calculations based on the extended Friedel sum rule–transport cross section formulation for the valence electrons and the shellwise local plasma approximation for the inner shells. This theoretical description reproduces reasonably well the experimental results on the whole studied energy range. The same occurs with previous measurements performed with H and He on the same target. The importance of the screened potential on the stopping power due to the valence electrons is stressed in the present description.

The energy loss of helium ions in zinc has been measured in the energy range from 37.5 to 1750 keV/amu using the transmission technique and the Rutherford backscattering method. In addition, calculations using the extended Friedel sum rule, the unitary convolution approximation, and the local plasma approximation have been performed. The contributions of the inner-shell and valence electrons to the total energy loss are separately evaluated. The measurements and calculations are in good agreement over an extended range of energies, and both of them yield stopping values higher than those provided by SRIM 2003.

En una serie de experimentos de colisiones de partículas atómicas y nucleares con la materia condensada, las inhomogeneidades en espesor de los blancos producen indeterminaciones en diversos tipos de mediciones. Presentamos aquí algunas formas sencillas de acotar las citadas inhomogeneidades de haces iónicos: a) Midiendo la pérdida de energía ΔE y la desviación Ω standard del espectro de pérdida de energía de un dado tipo de iones en la lámina en cuestión. b) Mediante la determinación de las pérdidas de energía y la desviación standard de H+ y He+ en la folia a analizar c) Mediante la determinación de los frenamientos y desviaciones standard de protones y moléculas-ión hidrógeno. Se aplican los tres métodos a láminas de Mn y se encuentra que los tres dan resultados coherentes Fil: Eckardt, J. C.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche (CNEA-CAB). Río Negro. Argentina Fil: Lantschner, G. H.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche (CNEA-CAB). Río Negro. Argentina

Se han medido las distribuciones angulares de protones e iones moleculares de hidrógeno de dos unidades atómicas de velocidad, después de atravesar blancos autosoportantes de aluminio de aproximadamente 210 A de espesor. Comparando el cuadrado de distribución de los protones con la de los iones moleculares normalizada adecuadamente, se observa una muy buena coincidencia. Esto significa que no hay correlación con los dos protones constituyentes de la molécula en los procesos de colisión elástica durante su pasaje a través de la lámina Fil: Eckardt, J. C.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche (CNEA-CAB-CONICET). Río Negro. Argentina Fil: Lantschner, G. H.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche (CNEA-CAB-CONICET). Río Negro. Argentina