  We perform Low Energy Ion Scattering with 1\,keV He ions on CaSiO$_3$ using a
commercial electrostatic detector system and determine the charge fraction of
scattered ions from comparison with Binary Collision Approximation simulations.
The simulations take dynamical surface changes due to surface cleaning Ar
sputtering into account and scattered He particles are separated into single,
dual, and multiple scattering trajectories. We find that the charge fraction of
single and dual scattered He is about 10 times higher than the one for multiple
collisions. Our results show that quantitative concentration profiles can be
inferred from this method, if the charge fraction components are determined
first.
