Ranges of Low-Energy Gallium Atoms in Copper and Zinc

The ranges of 0.07-1.0-MeV gallium atoms in copper and zinc have been measured by means of thicktarget recoil experiments. Monoenergetic gallium recoils were generated by the ${\mathrm{Zn}}^{64}(p, \gamma )$, ${\mathrm{Zn}}^{64}(d, \gamma )$, and ${\mathrm{Cu}}^{63}(\alpha , \gamma )$ reactions. The results can be expressed by an empirical range-energy relation of the form $R(\mu \mathrm{g}/{\mathrm{cm}}^2)=0.193\mathrm{} E$(keV) for $E\le 1.0$ MeV. The results of the present experiment and of other studies in this mass range are compared with the theoretical range-energy relation of Lindhard, Scharff, and Schiott, and very good agreement is found for values of the reduced energy ranging from 0.4 to 5.0. The low-energy results are also compared with the calculation of Oen, Holmes, and Robinson. In its simplest form, this calculation predicts range values that are significantly larger than the experimental results.