Scattering of High-Velocity Neutral Particles. IV. He–A; A–He

Abstract

Total collision cross sections have been measured for helium atoms with energies between 500 and 2100 ev, scattered in room temperature argon, and for argon atoms with energies between 600 and 2100 ev, scattered in room temperature helium. In each case, two detectors of different geometric aperature have been used, and potential energy functions have been obtained by procedures previously applied to helium scattered in helium. The average function for the potential energy between a helium atom and an argon atom derived from the measured cross sections may be represented by V(r)=9.95×10−11/r7.25ergs,for values of r between 1.64A and 2.27A. Since this potential is in good agreement with the geometric mean of the potential between two helium atoms and that between two argon atoms in the range represented by the arithmetic average of the individual interaction distances, it is suggested that the parameters of a point repelling type potential function may, in general, be combined in this manner.