Channeling measurements are reported which determine the radial distribution of defects, across the ⟨111⟩ and ⟨110⟩ channels, created by 20–40 keV He+, N+and Zn+bombardments of Si, GaAs and GaP at 50 K. Also the damagevs.dose data are reported for the above systems and for heavier ions, both monatomic and diatomic. The results of both sets of measurements are correlated into a consistent model in which the channeled beam backscatters off the grossly displaced atoms and small atom relaxations due to strains necessary to accommodate the damage. It is shown that at low damage levels (≲10%) the channeling technique accurately determines the number of displaced atoms,ND, but at higher damage levels, interactions with the relaxed atoms will result in an over-estimate ofND. The degree of over-estimation increases as Z1decreases and dominates for very low Z1ions. A model is developed which adequately fits the damagevs.dose behavior in which the strain-induced component is assumed proportional toND.