Ion-Atom Potential Energy Functions Obtained from kev Scattering Data

The potential energy functions between ions and atoms in collision are determined from experimental data. The ion-atom combinations studied include ${\mathrm{Ar}}^{+}$ on Ar, ${\mathrm{Ne}}^{+}$ on Ar, ${\mathrm{Ne}}^{+}$ on Ne, ${\mathrm{He}}^{+}$ on Ar, ${\mathrm{He}}^{+}$ on Ne, and ${\mathrm{He}}^{+}$ on He, using differential cross-section measurements by Fuls et al. and Jones et al. made at 25, 50, and 100 kev. These data are analyzed using equations developed by Firsov. The potential energies are positive, are in the range of one to sixty thousand electron volts, and correspond to ion-atom separations of a small fraction of an angstrom.