Z2dependence of the electronic stopping power of low-velocity channelled heavy ions

Calculations have been made of the electronic stopping power of different metals for 42 K ions moving along (100) directions in BCC crystals and along (110) directions in FCC crystals. The model used is the same as that used recently in calculating the stopping power of a given target for different projectiles; namely that the incoming ion loses energy by transferring momentum to target electrons which scatter elastically from it when the ion velocity is low. The dependence on the atomic number Z 2 of the target is seen to come primarily from the difference in the effective density of the target electrons which is determined by crystal constants. The trend to the calculated results is compared with available experimental data.