Single-collision scattering of keV-energy Kr ions off a polycrystalline Cu surface

In the keV-energy regime, the scattering of krypton ions off a copper sample has been studied. In addition to the broad energy spectrum arising from multiple-collision scattering, the energy distributions of the backscattered ions exhibit prominent peaks at energies where single-collision (SC) scattering peaks are expected. Such SC peaks were shown to be absent in Sn – Mo/Ru scattering, systems of similar mass ratio and thus similar kinetics. The present Kr on Cu results allow for a comparison to a simulation package as SRIM. An important difference found between the present experiment and the predictions of SRIM is that the SC contribution is observed to decrease with scattering angle, whereas SRIM predicts this contribution to be constant. The intensity of the experimental SC peaks, though much weaker than in the SRIM simulations, may be used as markers to improve SRIM in its description of low-energy heavy particle scattering off surfaces.