Elastic and charge-exchange cross sections have been measured in the energy range 4 to 400 ev for Ne+ in A, A+ in Ne, and A+ in A. Charge exchange was observed only for A+ in A. No evidence was found for the existence of the diatomic ion NeA+. Constants for empirical potential functions have been evaluated and the functions tabulated.

Cross sections have been measured for both elastic and inelastic collisions of He+ ions in the energy range from 4 to 400 ev with helium atoms in the gas phase. Charge exchange was the only inelastic process observed except at the highest energies, where very small cross sections for ionization were obtained. Cross sections for charge exchange decreased slowly with increasing ion energy. The potential functions determined from the elastic scattering data are V=−34.5r−6.88 for r>1.7Aand V=−5.15r−2.90 for r<1.7A.Assuming an equilibrium distance of 1.1A the interaction energy for the formation of the molecular ion He2+ is calculated to be 3.9 ev.

Cross sections have been measured in the energy range 4 to 400 ev for elastic scattering and charge exchange of H+ and H2+ ions in hydrogen. The results are compared with similar measurements for deuterium ions in deuterium. Charge exchange was observed over the entire energy range for H2+, but was detected only above 50 ev for H+. Constants for empirical potential functions have been evaluated and are tabulated.

Results are presented of the measurement in the energy range 4 to 400 ev of elastic and charge exchange cross sections for D+ and D2+ ions in D2. Ordinary ionization was not observed. Charge exchange was detected above 65 ev for D+ in D2 and over the entire range of energies for D2+ in D2. The present results are compared with measurements of collisions of hydrogen ions in H2.

Experimental results are presented for collisions in the energy range 4 to 400 electron volts of He+ ions in neon and of Ne+ ions in helium and in neon. Charge exchange was observed only in the case of Ne+ in neon. Empirical potential functions for the interactions are tabulated and discussed. It is concluded that the HeNe+ ion, if formed, would probably separate if subjected to impact at thermal energies.