Scattering of Fast Potassium Ions by Small Molecules

Measurements have been made of the effective total cross sections for the scattering of potassium ions with energies between 100 and 2350 eV by room temperature O2, N2, CO, NO, CO2, and N2O. The repulsive interaction potentials were deduced from the energy dependence of the cross sections using both the inverse power and exponential representations of the potential function. The results appear to be self-consistent, indicating no measurable difference between the potentials for K+ interacting with O2, N2, NO, or CO, or between the potentials for K+ interacting with CO2 or N2O. Where it is possible to compare with other work, significant differences are found, as happened previously in reports of potentials of K+ interacting with several rare gas atoms. The potentials were compared to those determined in this laboratory by scattering argon beams with the same molecules and the potentials for the two isoelectronic systems were found, in all cases studied, to be essentially identical and actually cross in the energy range studied.