Charge state dependence of channeled ion energy loss

Abstract

The charge state dependence of channeled ion energy loss has been determined for a series of ions ranging from fluorine to chlorine along the ⟨110⟩ direction in a silicon crystal. Energy losses for both bare ions and ions partially clothed with bound electrons at EA≅3 MeV/amu have been measured. The energy-loss rate for bare ions follows a strict Z21 scaling and agrees reasonably well with quantal perturbation calculations without the need for polarization or Bloch corrections. An explanation for this result is discussed. The clothed-ion energy losses appear to demonstrate screening effects that agree qualitatively with simple estimates. The angular dependence of the observed energy-loss effects is also presented.