Moreover, neither the Kinchin-Pease equation nor SRIM take in any way account of ion channeling, which may in crystalline or polycrystalline materials reduce the nuclear deposited energy and thus the damage production dramatically for some ion-target combinations. For instance, keV ion implantation into the Si 110 crystal direction leads to massive channeling and thus reductions in stopping power. Similarly, light ion like He irradiation of a BCC metal like Fe leads to massive channeling even in a randomly selected crystal direction.