Scattering of High Velocity Neutral Particles. VIII. H–He

Total collision cross sections have been measured for hydrogen atoms with energies between 700 and 2100 ev, scattered in room temperature helium. The results have been analyzed to obtain potential energy information for the interaction between a hydrogen atom and a helium atom. The potential function, which may be represented by $${\text{V(r)=3.75×10}}^{\text{−12}}{\mathrm{/r}}^{\text{3.29}}\hspace{0.17em}\mathrm{erg}$$ for r between 1.16 A and 1.71 A, gives values which agree with those calculated quantum mechanically by Mason, Ross, and Schatz. The H–He potential has been combined with a potential previously obtained for He–He to obtain a function which, it is suggested, represents the repulsive interaction between two hydrogen atoms. The derived function is in fair agreement with theoretical calculations of Hirschfelder and Linnett for the repulsive ³Σ state of the hydrogen molecule.