Etude du ralentissement des ions lourds dans une cible diatomique

Abstract

Nous décrivons une méthode de calcul qui permet de déterminer la distance parcourue, l'énergie cédée au réseau et le nombre 'atomes primaires mis en mouvement par un ion lourd se ralentissant dans un corps composé. Ce calcul a été appliqué au cas des fragments de fission se ralentissant dans UO₂. A computational code based on the Lindhard, Scharff and Schiott's theory is described. It determines the range, the energy transferred to the lattice and the number of primary knock-on atoms created during the slowing down of a heavy ion in a diatomic target. The calculated mean range values for uranium ions, oxygen ions and fission fragments in UO₂ are in good agreement with those obtained from Bragg's formula. The number of primary atoms created by these incident particles was also calculated. To our knowledge, it is the first attempt to evaluate the energy transferred to the lattice by high energy heavy ions in a diatomic target.