Projectile charge and velocity effect on UO2 sputtering in the nuclear stopping regime

Abstract

Angular distributions and yields of uranium sputtered by slow highly charged Xeq+ ions (kinetic energy \(1.5~{\rm keV}\le E_{k}\le 81\) keV, charge state 1≤q≤25) from UO2 were measured by means of the catcher technique. A charge state effect on the sputtering process is observed at 8 and 81 keV. A deviation from a Acosθ shape (the linear collision cascade theory) is observed in case of Xeq+ impinging a UO2 surface at Ek=8 keV. Yields increase linearly with projectile charge state q thus clearly revealing the contribution of potential energy to the sputtering process. In addition, as the kinetic energy of a Xe10+ projectile decreases from 81 keV to 1.5 keV, a velocity effect is clearly observed on the angular distribution.