Spatial distributions of energy deposited by heavy ions into nuclear collisions

The energy deposited into elastic collisions by heavy ions along their path has been determined experimentally for various ions in the energy range 20-1000 keV. Firstly, the total energy ν lost into nuclear interactions is measured by detecting the ions in a specially developped silicon counter in and off channeling conditions. Secondly, the profile of damage resulting from the bombardment of a silicon target is determined by the backscattering-channeling technique. During this second step, the implantation is performed at a very low dose and followed by an in situ analysis at 77 K. Supposing that the total area under the damage peak corresponds to the quantity ν it becomes possible to calibrate in an absolute scale (eV/A) the energy deposited in nuclear collisions along the ion path. The validity of this hypothesis is discussed and the profiles compared to theoretical models as well as to other experimental results. Furthermore, it has been established that the oscillations of the electronic stopping affects the energy deposition by nuclear interactions even for ions entering the target randomly